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| United States Patent |
6,498,883
|
|
Wilson
|
December 24, 2002
|
Optical fiber ribbon with pigmented matrix material and processes for
making same
Abstract
Optical fiber ribbon, and a process for making same, that employs
radiation-curable, colored matrix material and comprises a plurality of
colored optical fibers in a fixed arrangement, preferably parallel to one
another, embedded within the cured matrix material. The colored matrix
material is opaque, thereby providing a wider variety of distinguishable
matrix colors and hiding bleed-through from ink on coated optical fibers.
| Inventors:
|
Wilson; Daniel A. (Cincinnati, OH)
|
| Assignee:
|
Borden Chemical, Inc. (Columbus, OH)
|
| Appl. No.:
|
115076 |
| Filed:
|
April 4, 2002 |
| Current U.S. Class: |
385/114 |
| Intern'l Class: |
G02B 006/44 |
| Field of Search: |
385/114,128
522/39,64,75,81,83,18,96,103
|
References Cited [Referenced By]
U.S. Patent Documents
| 4844604 | Jul., 1989 | Bishop et al.
| |
| 5534559 | Jul., 1996 | Leppard et al.
| |
| 6130980 | Oct., 2000 | Murphy et al.
| |
| 6136880 | Oct., 2000 | Snowwhite et al.
| |
| 6195491 | Feb., 2001 | Jackson et al. | 385/106.
|
| 6362249 | Mar., 2002 | Chawla | 522/116.
|
| 6381390 | Apr., 2002 | Hutton et al. | 385/114.
|
| 2001/0048797 | Dec., 2001 | Van Dijk et al. | 385/114.
|
| Foreign Patent Documents |
| 08-171033 | Jul., 1996 | JP.
| |
| 9142889 | May., 1997 | WO.
| |
| 9718493 | May., 1997 | WO.
| |
| 9719029 | May., 1997 | WO.
| |
Primary Examiner: Berman; Susan
Attorney, Agent or Firm: Stevens, Davis, Miller & Mosher, LLP
Parent Case Text
This claims priority from U.S. provisional patent application Ser. No.
60/281,379 filed Apr. 5, 2001, incorporated herein by reference in its
entirety.
Claims
I claim:
1. An optical fiber ribbon comprising:
a plurality of optical fibers embedded within a matrix, wherein the matrix
is formed from a reactive mixture comprising:
(a) about 80 to about 99.7 percent by weight of a base resin comprising one
or more acrylated, methacrylated or vinyl functional oligomers and/or
monomers;
(b) about 0.1 to about 10 percent by weight of a photoinitiator that
absorbs light in the wavelength region above about 400 nm
(c) about 0.1 to about 10 percent by weight of an opacifier blend, unless
the matrix, when cured, is black, in which case about 0 to about 10
percent by weight of an opacifier blend; and
(d) about 0.01 to about 10 percent by weight of at least one color blend;
wherein the foregoing percentages by weight are based on the total weight
of (a), (b), (c) and (d);
wherein, after curing, the matrix has a color selected from the group
consisting of blue, orange, green, brown, slate, white, red, black,
yellow, violet, rose and aqua;
wherein, when a first 100 micron thick sample of the matrix, which is 80 mm
wide and 120 mm long, is cured on a glass plate 6 mm thick with a
radiation dose of about 0.2 J/cm.sup.2, the first 100 micron sample
exhibits an inside degree of cure as an inside percent reacted acrylate
unsaturation of more than about 70 percent as measured via FTIR-ATR;
wherein, when placed under a clear 150 micron thick UV-curable coating
which is substantially free of chromophores, a 25 micron thick by 75 mm
wide by 180 mm long sample of the cured matrix exhibits, as determined by
a means for spectrophotometrically analyzing, a hue angle range having the
following values for each respectively colored matrix: blue is about 230
to about 270; orange is about 55 to about 80; green is about 120 to about
185; brown is about 35 to about 80; slate is about 0 to about 360; white
is about 0 to about 360; red is about 325 to about 50; black is about 0 to
about 360; yellow is about 80 to about 120; violet is about 270 to about
325; rose is about 0 to about 22; and aqua is about 184 to about 230; and
wherein a second 100 micron thick by 80 mm wide by 120 mm long sample of
the cured matrix exhibits a minimum contrast ratio, as measured via the
measurement procedure portion of ASTM D2805-88, having the following
values for each respectively colored matrix: blue is about 42; orange is
about 30; green is about 8; brown is about 22; slate is about 24; white is
about 36; red is about 30; black is about 3; yellow is about 27; violet is
about 16; rose is about 37; and aqua is about 35.
2. The optical fiber ribbon of claim 1, wherein the optical fibers are
colored; wherein the color blend is a pigment blend; and wherein the
photoinitiator absorbs light in the wavelength region above about 400 nm.
3. The optical fiber ribbon of claim 2, wherein the 25 micron sample of the
cured matrix exhibits, when placed under the 150 micron thick UV-curable
coating, a lightness range, as determined by the means for
spectrophotometrically analyzing, having the following values for each
respectively colored matrix: blue is about 55 to about 80; orange is about
57 to about 82; green is about 70 to about 95; brown is about 54 to about
79; slate is about 61 to about 86; white is about 78 to about 98; red is
about 46 to about 71; black is about 60 to about 85; yellow is about 73 to
about 98; violet is about 60 to about 85; rose is about 59 to about 84;
and aqua is about 67 to about 92.
4. The optical fiber ribbon of claim 3, wherein the 25 micron sample of the
cured matrix exhibits, when placed under the 150 micron thick UV-curable
coating, the following chroma values, as determined by the means for
spectrophotometrically analyzing, for each respectively colored matrix:
blue is greater than about 18; orange is greater than about 48; green is
greater than about 12; brown is greater than about 18; slate is about 0 to
about 10; white is about 0 to about 12; red is greater than about 31;
black is about 0 to about 10; yellow is greater than about 39; violet is
greater than about 8; rose is greater than about 18; and aqua is greater
than about 15.
5. The optical fiber ribbon of claim 4, wherein the first 100 micron sample
exhibits a percent reacted acrylate unsaturation of more than about 80
percent.
6. The optical fiber ribbon of claim 5, wherein the 25 micron sample of the
cured matrix exhibits a hue angle range having the following values for
each respectively colored matrix: blue is about 230 to about 260; orange
is about 55 to about 75; green is about 120 to about 150; brown is about
50 to about 80; slate is about 30 to about 220; white is about 85 to about
153; red is about 0 to about 50; black is about 3 to about 113; yellow is
about 90 to about 115; violet is about 290 to about 325; rose is about 5
to about 22; and aqua is about 184 to about 210.
7. The optical fiber ribbon of claim 6, wherein the second 100 micron
sample exhibits a minimum contrast ratio having the following values for
each respectively colored matrix: blue is about 64; orange is about 46;
green is about 12; brown is about 33; slate is about 36; white is about
55; red is about 46; black is about 5; yellow is about 41; violet is about
25; rose is about 56; and aqua is about 53.
8. The optical fiber ribbon of claim 7, wherein the 25 micron sample
exhibits a lightness range having the following values for each
respectively colored matrix: blue is about 60 to about 80; orange is about
60 to about 80; green is about 75 to about 95; brown is about 59 to about
79; slate is about 66 to about 86; white is about 83 to about 98; red is
about 51 to about 71; black is about 60 to about 80; yellow is about 80 to
about 95; violet is about 65 to about 85; rose is about 62 to about 82;
and aqua is about 72 to about 87.
9. The optical fiber ribbon of claim 8, wherein the 25 micron sample
exhibits the following chroma values for each respectively colored matrix:
blue is greater than about 28; orange is greater than about 72; green is
greater than about 13.5; brown is greater than about 25; slate is about 0
to about 7; white is about 0 to about 11; red is greater than about 48;
black is about 0 to about 5; yellow is greater than about 51; violet is
greater than about 11; rose is greater than about 21; and aqua is greater
than about 19.
10. The optical fiber ribbon of claim 9, wherein the inside percent reacted
acrylate unsaturation of the first 100 micron sample is more than about 85
percent.
11. The optical fiber ribbon of claim 10, wherein the 25 micron sample of
the cured matrix exhibits a hue angle range having the following values
for each respectively colored matrix: blue is about 233 to about 250;
orange is about 61 to about 69; green is about 120 to about 143; brown is
about 58 to about 78; slate is about 69 to about 190; white is about 100
to about 138; red is about 19 to about 31; black is about 18 to about 98;
yellow is about 99 to about 112; violet is about 292 to about 324; rose is
about 7 to about 22; and aqua is about 184 to 202.
12. The optical fiber ribbon of claim 11, wherein the second 100 micron
sample exhibits a minimum contrast ratio having the following values for
each respectively colored matrix: blue is about 71; orange is about 51;
green is about 14; brown is about 37; slate is about 40; white is about
61; red is about 51; black is about 6; yellow is about 46; violet is about
28; rose is about 63; and aqua is about 59; and
wherein the 25 micron sample exhibits a lightness range having the
following values for each respectively colored matrix: blue is about 63 to
about 75; orange is about 66 to about 77; green is about 79 to about 90;
brown is about 62 to about 74; slate is about 70 to about 81; white is
about 91 to about 98; red is about 55 to about 66; black is about 67 to
about 80; yellow is about 85 to about 93; violet is about 71 to about 82;
rose is about 64 to about 79; and aqua is about 76 to about 87.
13. The optical fiber ribbon of claim 2, wherein the opacifier blend
constitutes about 0.5 to about 3.5 percent of the weight of the matrix,
wherein the opacifier blend comprises an opacifying compound that
constitutes about 40 to about 50 percent of the weight of the opacifier
blend, and wherein the opacifying compound is selected from the group
consisting of TiO.sub.2, BaSO.sub.4, ZnO, and ZnS.
14. The optical fiber ribbon of claim 13, wherein the opacifying compound
is TiO.sub.2.
15. The optical fiber ribbon of claim 14, wherein the photoinitiator
comprises at least one photoinitiating compound selected from the group
consisting of bis-acyl phosphine oxide; hydroxycyclohexylphenyl ketone;
hydroxymethylphenylpropanone; dimethoxyphenylacetophenone;
2-methyl-1,4-(methyl thio)phenyl-2-morpholino-propanone-1;
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one;
4-(2-hydroxyethyoxy)phenyl-(2-hydroxy-2-propyl)ketone; 1-(4-dodecyl
phenyl)-2-hydroxy-2-methylpropan-1-one; diethoxyacetophenone;
2,2-di-sec-butoxy-acetophenone; diethoxyphenyl acetophenone;
bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide;
2,4,6-trimethylbenzoyldiphenylphosphine oxide;
2,4,6-trimethylbenzoylethoxyphenylphosphine oxide; and mixtures thereof.
16. The optical fiber ribbon of claim 14, wherein the photoinitiator
comprises bis-acyl phosphine oxide which constitutes about 0.25 to about 7
percent of the weight of the matrix.
17. The optical fiber ribbon of claim 16, wherein the photoinitiator
comprises phenyl bis(2,4,6-trimethylbenzoyl)-phosphine oxide which
constitutes about 0.5 to about 6 percent of the weight of the base resin.
18. The optical fiber ribbon of claim 17, wherein the photoinitiator
further comprises 1-hydroxycyclohexyl phenyl ketone which constitutes
about 0.5 to about 6 percent of the weight of the base resin.
19. The optical fiber ribbon of claim 18, wherein the photoinitiator
comprises bis(2,4,6-trimethylbenzoyl)-phosphine oxide in an amount that
constitutes about 2.25 percent of the weight of the base resin, and
1-hydroxycyclohexyl phenyl ketone in an amount that constitutes about 3
percent of the weight of the base resin.
20. The optical fiber ribbon of claim 2, wherein the pigment blend
constitutes about 0.9 to about 4 percent of the weight of the matrix, and
wherein the pigment blend comprises:
(a) one or more pigment compounds that constitute about 13 to about 20
percent of the weight of the pigment blend;
(b) tripropylene glycol diacrylate that constitutes about 1 to about 5
percent of the weight of the pigment blend;
(c) acrylated epoxy linseed oil that constitutes about 25 to about 35
percent of the weight of the pigment blend;
(d) a stabilizer blend, comprising epoxy acrylate and triacrylate
oligomers, that constitutes about 1 to about 2 percent of the weight of
the pigment blend; and
(e) an optional secondary clear coating that constitutes about 45 to about
55 percent of the weight of the pigment blend.
21. The optical fiber ribbon of claim 20, wherein the secondary coating
comprises:
(a) urethane acrylate oligomer and at least one other acrylate oligomer
that together constitute about 85 to about 98 percent of the weight of the
secondary coating;
(b) a photoinitiator that constitutes about 2 to about 6 percent of the
weight of the secondary coating; and
(c) optionally, an antioxidant that constitutes about 0.5 to about 1.5
percent of the weight of the secondary coating.
22. The optical fiber ribbon of claim 20, wherein the secondary coating
comprises:
(a) a urethane acrylate oligomer and hexanediol diacrylate monomer that
together constitute about 87 to about 96 percent of the weight of the
secondary coating;
(b) 1-hydroxycyclohexyl phenyl ketone in an amount that constitutes about 3
to about 5 percent of the weight of the secondary coating; and
(c) thiodiethylene(3,5-di-t-butyl-4-hydroxy)hydrocinnamate in an amount
that constitutes about 0.7 to about 1.3 percent of the weight of the
secondary coating.
23. The optical fiber ribbon of claim 2, wherein the base resin comprises:
(a) about 30 percent to about 80 percent by weight of one or more
acrylated, methacrylated or vinyl functional oligomers with a chemical
backbone based on an aliphatic urethane oligomer or epoxy oligomer, or a
combination thereof;
(b) from about 5 percent to about 45 percent by weight of one or more
reactive diluent monomers having about 1 to about 5 functional groups;
wherein all of the percentages by weight are based on the total weight of
(a) and (b).
24. The optical fiber ribbon of claim 2, wherein the base resin comprises:
(a) about 48 to about 52 percent by weight of one or more acrylated,
methacrylated or vinyl functional oligomers with a chemical backbone based
on an aliphatic urethane oligomer;
(b) about 35 to about 45 percent by weight of one or more reactive diluent
monomers having about 1 to about 5 functional groups selected from the
group consisting of acrylate, methacrylate, vinyl ether, vinyl and
combinations thereof, and
wherein all of the percentages by weight are based on the total weight of
(a) and (b).
25. The optical fiber ribbon of claim 24, wherein the aliphatic urethane
oligomer backbone is the reaction product of an aliphatic polyether polyol
and an aliphatic polyisocyanate.
26. The optical fiber ribbon of claim 25, wherein the functional group of
the monomer comprises an acrylate.
27. The optical fiber ribbon of claim 26, wherein the monomer comprises an
isocyanurate acrylate and isobornyl acrylate.
28. The optical fiber ribbon of claim 27, wherein the isocyanurate acrylate
comprises tris-hydroxyethyl isocyanurate triacrylate.
29. The optical fiber ribbon of claim 25, wherein the reactive diluent
comprises a monomer selected from the group consisting of C.sub.6
-C.sub.12 hydrocarbon diol diacrylates; C.sub.6 -C.sub.12 hydrocarbon diol
dimethacrylates; tripropylene glycol diacrylate; tripropylene glycol
dimethacrylate; neopentyl glycol diacrylate; neopentyl glycol
dimethacrylate; neopentyl glycol propoxylate diacrylate; neopentyl glycol
propoxylate dimethacrylate; neopentyl glycol ethoxylate diacrylate;
neopentyl glycol ethoxylate dimethacrylate; bisphenol A ethoxylate
diacrylate; bisphenol A ethoxylate dimethacrylate; bisphenol A propoxylate
diacrylate; bisphenol A propoxylate dimethacrylate; phenoxyethyl acrylate;
phenoxyethyl methacrylate; phenoxyethyl ethoxylate acrylate; phenoxyethyl
ethoxylate methacrylate; phenoxyethyl propoxylate acrylate; phenoxyethyl
propoxylate methacrylate; polyethylene glycol nonylphenylether acrylate;
polyethylene glycol nonylphenylether methacrylate; polypropylene glycol
nonylphenylether acrylate; polypropylene glycol nonylphenylether
methacrylate; isooctyl methacrylate; octyl acrylate; octyl methacrylate;
decyl acrylate; decyl methacrylate; isodecyl acrylate; isodecyl
methacrylate; lauryl acrylate; lauryl methacrylate; tridecyl acrylate;
tridecyl methacrylate; palmitic acrylate; palmitic methacrylate; stearyl
acrylate; stearyl methacrylate; cetyl acrylate; cetyl methacrylate;
tetrahydrofurfuryl acrylate; tetrahydrofurfuryl methacrylate; isobornyl
acrylate; isobornyl methacrylate; dicyclopentenyl acrylate;
dicyclopentenyl methacrylate; dicyclopentenyl ethoxylate acrylate;
dicyclopentenyl ethoxylate methacrylate; dicyclopentenyl propoxylate
acrylate; dicyclopentenyl propoxylate methacrylate; N-vinyl amides and
mixtures thereof.
30. The optical fiber ribbon of claim 25, wherein the oligomer comprises an
acrylated oligomer.
31. The optical fiber ribbon of claim 2, wherein the matrix comprises about
0.1 percent to about 2 percent by weight of the matrix of an oxidation
stabilizer selected from the group consisting of tertiary amines, hindered
amines, organic phosphites, hindered phenols, hydrocinnamates,
propionates, and mixtures thereof.
32. The optical fiber ribbon of claim 2, wherein the base resin constitutes
about 87 to about 95 percent of the weight of the matrix.
33. The process of claim 1, wherein said photoinitiator has an absorption
value of greater than about 0.1 at 400 nm when measured at 0.1%
concentration by weight in a non-absorbing solvent and path length of 1.0
centimeters.
34. The optical fiber ribbon of claim 1, wherein the cured matrix is blue.
35. The optical fiber ribbon of claim 1, wherein the cured matrix is
orange.
36. The optical fiber ribbon of claim 1, wherein the cured matrix is green.
37. The optical fiber ribbon of claim 1, wherein the cured matrix is brown.
38. The optical fiber ribbon of claim 1, wherein the cured matrix is slate.
39. The optical fiber ribbon of claim 1, wherein the cured matrix is white.
40. The optical fiber ribbon of claim 1, wherein the cured matrix is red.
41. The optical fiber ribbon of claim 1, wherein the cured matrix is black.
42. The optical fiber ribbon of claim 1, wherein the cured matrix is
yellow.
43. The optical fiber ribbon of claim 1, wherein the cured matrix is
violet.
44. The optical fiber ribbon of claim 1, wherein the cured matrix is rose.
45. The optical fiber ribbon of claim 1, wherein the cured matrix is aqua.
46. A radiation-curable matrix material for affixing coated and optical
fibers in a ribbon configuration in which are embedded at least two
optical fibers, comprising:
(a) about 87 to about 95 percent by weight of a base resin comprising one
or more acrylated, methacrylated or vinyl functional oligomers and/or
monomers;
(b) about 0.1 to about 10 percent by weight of a photoinitiator that
absorbs light in the wavelength region above about 400 nm;
(c) about 0.1 to about 10 percent by weight of an opacifier blend, unless
the matrix material, when cured, is black, in which case about 0 to about
10 percent by weight of an opacifier blend; and
(d) about 0.01 to about 10 percent by weight of at least one color blend;
wherein the foregoing percentages by weight are based on the total weight
of (a), (b), (c) and (d);
wherein, after curing, the matrix material has a color selected from the
group consisting of blue, orange, green, brown, slate, white, red, black,
yellow, violet, rose and aqua;
wherein, when a first 100 micron thick by 80 mm wide by 120 mm long sample
of the matrix is cured on a glass plate 6 mm thick with a radiation dose
of about 0.2 J/cm.sup.2, the first 100 micron sample exhibits a percent
reacted acrylate unsaturation of more than about 70 percent as measured
via FTIR-ATR;
wherein, when placed under a clear 150 micron thick UV-curable coating
which is substantially free of chromophores, a 25 micron thick by 75 mm
wide by 180 mm long sample of the cured matrix exhibits, as determined by
a means for spectrophotometrically analyzing, a hue angle range having the
following values for each respectively colored matrix material: blue is
about 230 to about 270; orange is about 55 to about 80; green is about 120
to about 185; brown is about 35 to about 80; slate is about 0 to about
360; white is about 0 to about 360; red is about 325 to about 50; black is
about 0 to about 360; yellow is about 80 to about 120; violet is about 270
to about 325; rose is about 0 to about 22; and aqua is about 184 to about
230; and
wherein a second 100 micron thick by 80 mm wide by 120 mm long sample of
the cured matrix material exhibits a minimum contrast ratio, as measured
via the measurement procedure portion of ASTM D2805-88, having the
following values for each respectively colored matrix material: blue is
about 42; orange is about 30; green is about 8; brown is about 22; slate
is about 24; white is about 36; red is about 30; black is about 3; yellow
is about 27; violet is about 16; rose is about 37; and aqua is about 35.
47. The matrix material of claim 46, wherein the optical fibers are
colored; wherein the color blend is a pigment blend; and wherein the
photoinitiator absorbs light in the wavelength region above about 325 nm.
48. A process for preparing an optical fiber ribbon comprising:
mechanically arranging coated optical fibers in a generally parallel
arrangement relative to each other;
applying about said fibers the liquid form of a radiation-curable matrix
material comprising:
(a) about 85 to about 99 percent by weight of a base resin comprising one
or more acrylated, methacrylated or vinyl functional oligomers and/or
monomers;
(b) about 0.1 to about 10 percent by weight of a photoinitiator that
absorbs light in the wavelength region above about 400 nm;
(c) about 0.1 to about 10 percent by weight of an opacifier blend, unless
the matrix material, when cured, is black, in which case about 0 to about
10 percent by weight of an opacifier blend; and
(d) about 0.01 to about 10 percent by weight of at least one color blend;
wherein the foregoing percentages by weight are based on the total weight
of (a), (b), (c) and (d);
curing said matrix material, thereby securing said fibers in said
arrangement;
wherein, after curing, the matrix material has a color selected from the
group consisting of blue, orange, green, brown, slate, white, red, black,
yellow, violet, rose and aqua;
wherein, when a first 100 micron thick by 80 mm wide by 100 mm long sample
of the matrix is cured on a glass plate 6 mm thick with a radiation dose
of about 0.2 J/cm.sup.2, the first 100 micron sample exhibits a percent
reacted acrylate unsaturation of more than about 70 percent as measured
via FTIR-ATR;
wherein, when placed under a clear 150 micron thick UV-curable coating
which is substantially free of chromphores, a 25 micron thick by 75 mm
wide by 180 mm long sample of the cured matrix exhibits, as determined by
a means for spectrophotometrically analyzing, a hue angle range having the
following-values for each respectively colored matrix material: blue is
about 230 to about 270; orange is about 55 to about 80; green is about 120
to about 185; brown is about 35 to about 80; slate is about 0 to about
360; white is about 0 to about 360; red is about 325 to about 50; black is
about 0 to about 360; yellow is about 80 to about 120; violet is about 270
to about 325; rose is about 0 to about 20; and aqua is about 184 to about
230; and
wherein a second 100 micron thick by 80 mm wide by 120 mm long sample of
the cured matrix material exhibits a minimum contrast ratio, as measured
via the measurement procedure portion of ASTM D2805-88, having the
following values for each respectively colored matrix material: blue is
about 42; orange is about 30; green is about 8; brown is about 22; slate
is about 24; white is about 36; red is about 30; black is about 3; yellow
is about 27; violet is about 16; rose is about 37; and aqua is about 35.
49. The process of claim 48, wherein the optical fibers are colored;
wherein the color blend is a pigment blend; and wherein the photoinitiator
has an absorption value of at least 1 at 325 nm when measured at 0.1%
concentration by weight in a non-absorbing solvent and path length of 1.0
centimeters.
Description
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to optical fibers embedded in ribbon matrix
materials; to optical fiber ribbon arrays containing such matrix
materials; and to processes for preparing same.
II. Description of the Prior Art
In certain applications, such as in short haul fiber-to-the-home uses, a
single coated optical fiber may adequately transmit a signal from one
point to the next. In most embodiments, however, a relatively large number
of fibers are necessary to transmit a large volume of signals. For
example, the telecommunications industry often requires aggregates of
fibers spanning oceans or continents and containing dozens of individual
fibers. Fibers are conveniently aggregated into cables, wherein large
numbers of coated optical fibers are laid in parallel and are protected by
a common sheathing material which may include fiberglass, steel tape and
reinforced rubber cabling material.
When numerous individual coated optical fibers are aggregated into a cable,
it is necessary to be able to identify each of the individual fibers. For
example, when two cable segments are to be spliced together, it is
necessary to splice together ends of each like optical fiber in order for
a signal to convey properly. When only a few fibers are contained in a
cable, identification is facilitated by coating each individual fiber with
a characteristic color. Thereby, the splicer may simply match up green
fiber to green fiber, red to red, and so forth.
When the cable contains one hundred or more fibers, however, it becomes
difficult to impart a sufficient number of distinctive inks to color each
fiber distinguishably. Thus, a geometric means of distinguishing the
fibers is also used. For example, it is known to arrange the fibers in a
number of layers or two-dimensional fiber arrays with each layer or array
containing perhaps twelve ink-coated fibers of different colors. These.
layers or arrays are stacked one atop the other to form three-dimensional
structures known in the art as ribbons. The ribbons greatly facilitate
matching up fibers when splicing.
The matrix material of the ribbons should, inter alia, have suitable glass
transition temperature; cure rapidly; be non-yellowing; and have high
thermal, oxidative and hydrolytic (moisture) stability. Further, the
matrix material must possess solvent resistance, inasmuch as splicers
typically remove residual matrix and coating material from stripped fibers
using a solvent such as trichloroethane or ethanol or isopropanol or other
commercially available solvent. Additionally, the matrix material must
adhere sufficiently to the coated, colored optical fibers to prevent
separation of the fibers during processing into cables, but not adhere so
much as to remove the ink or other coloration from the individual fibers
when the matrix material is stripped from the fibers to permit splicing.
Removal of an ink layer from a fiber is referred to in the industry as
"breakout failure." It makes identification of the individual fibers
nearly impossible. Also, the matrix material should be removable via
thermal stripping at commonly-used stripping temperatures. Finally, the
matrix and all underlying coatings contained within the ribbon should be
removable in an intact tube, leaving a minimal amount of residue on the
fibers.
Like individual fibers, individual ribbons are color-coded with inks,
pigments or dyes. (Pigments are used in suspension; dyes are used in
solution.) The prior art, however, offers ribbons that contain lower
levels of pigment and are therefore too transparent, making color
identification and differentiation difficult. Further, the pigments, dyes
or inks in the color-coded optical fibers inside the ribbons tend to
bleed, and prior art ribbons cannot adequately hide the bleed-through
because they are insufficiently opaque.
The colors and opacity of the ribbons have been limited by the fact that
pigments (or other colored materials) interfere with curing of the matrix
material. Matrix material is typically cured when UV light is absorbed by
photoinitiators in the matrix material. Pigments reduce the light that can
be absorbed by the photoinitiator.
Incomplete cure causes many problems, including poor thermal strippability,
reduced toughness, tackiness, odor and residual extractable material after
curing. These problems have been addressed in the past by adding high
levels of short-wavelength--absorbing photoinitiators, but this approach
cannot be used in thicker films because high levels of these
photoinitiators also reduce light penetration. Specifically, light
absorption by photoinitiator in the upper layer of the film decreases the
light reaching the bottom of the film, and inadequate cure at the bottom
layer of the matrix profoundly affects ribbon performance. Of course, it
helps to increase the curing time, but this slows production
significantly.
Accordingly, there is a need in the art for matrix material that contains
pigment, dyes, inks or other colored substances suitable to impart a
variety of colors of sufficient opacity without thereby hampering cure,
especially deep within the matrix film.
SUMMARY OF THE INVENTION
The invention provides: (1) a radiation-curable matrix material for
affixing coated and colored optical fibers in a ribbon configuration
containing at least two optical fibers, the matrix material exhibiting
particular characteristics as defined below; (2) an optical fiber ribbon
employing such matrix material and comprising a plurality of optical
fibers in a fixed arrangement, preferably parallel to one another, within
the cured matrix material; (3) a process for preparing an optical fiber
ribbon using the aforesaid matrix material; and (4) a radiation-curable
matrix composition including the same ingredients as the aforesaid matrix
material and exhibiting similar characteristics.
Generally, the matrix material imparts sufficient opacity without causing
problems with cure, strippability, adhesion to colored fibers, tackiness,
odor, extractables and other requisite properties of matrix material. More
specifically, after curing, the matrix material produces the following
inside degrees of cure, hue angle ranges, minimum contrast ratios,
lightness ranges and chroma values, measured as described below.
A 100 micron thick by 80 mm wide by 120 mm long sample of the matrix
material exhibits an inside degree of cure of more than about 70 percent
when cured with a radiation dose of about 0.2 J/cm.sup.2, preferably more
than about 80 percent, most preferably more than about 85 percent. The
values for degree of cure were determined by measuring, in samples of the
matrix material as cured on glass plates about 6 mm thick, the percent
reacted acrylate unsaturation (%RAU) via FTIR--ATR using a diamond crystal
ATR attachment. By an inside degree of cure it is meant the degree of cure
of a bottom surface of the sample after curing. The cured samples were 100
microns thick, 80 mm wide and 120 mm long. The acrylate analytical peak
was 1410 cm.sup.-1 and the reference peak was 1520 cm.sup.-1. For
non-acrylated materials (i.e., vinyl or other functional groups capable of
reacting with a free radical), an alternative method may be used, but more
than about 70 percent of the total reactive groups should still undergo
reaction at this cure dose.
A 25 micron thick by 75 mm wide by 180 mm long sample film of the cured
matrix material exhibits a hue angle range which, when determined by means
for spectrophotometrically analyzing, has the following values for each
respectively colored matrix material: blue is about 230 to about 270;
orange is about 55 to about 80; green is about 120 to about 185; brown is
about 35 to about 80; slate is about 0 to about 360; white is about 0 to
about 360; red is about 325 to about 50; black is about 0 to about 360;
yellow is about 80 to about 120; violet is about 270 to about 325; rose is
about 0 to about 22; and aqua is about 184 to about 230. Preferably,
however, the 25 micron sample exhibits a hue angle range having the
following values for each respectively colored matrix: blue is about 230
to about 260; orange is about 55 to about 75; green is about 120 to about
150; brown is about 50 to about 80; slate is about 30 to about 220; white
is about 85 to about 153; red is about 0 to about 50; black is about 3 to
about 113; yellow is about 90 to about 115; violet is about 290 to about
325; rose is about 5 to about 22; and aqua is about 184 to about 210. More
preferably, the 25 micron sample exhibits a hue angle range having the
following values for each respectively colored matrix: blue is about 233
to about 250; orange is about 61 to about 69; green is about 120 to about
143; brown is about 58 to about 78; slate is about 69 to about 190; white
is about 100 to about 138; red is about 19 to about 31; black is about 18
to about 98; yellow is about 99 to about 112; violet is about 292 to about
324; rose is about 7 to about 22; and aqua is about 184 to 202.
The foregoing hue angle ranges were determined by spectrophotometrically
analyzing 25 micron thick by 75 mm wide by 180 mm long samples of the
matrix material as cured underneath a 150 micron layer of a UV-curable
coating which is substantially free of chromophores. Such a clear coating
is described in Table 6. Means for spectrophotometrically analyzing is
limited to using a spectrophotometer in which the samples are measured on
top of a white background tile (Hunter Lab #C2-1186) and the
spectrophotometer has the following settings: Illuminant=C, Observer=2
degrees, Spectral Component=Excluded. Means for spectrophotometrically
analyzing is limited as above only for purposes of defining and
standardizing the physical characteristics exhibited by the inventive
matrix material.
A 100 micron thick by 80 mm wide by 120 mm long sample of the cured matrix
material also exhibits a minimum contrast ratio, as measured via a
modified version of ASTM D2805-88, having the following minimum values for
each respectively colored matrix material: blue is about 42; orange is
about 30; green is about 8; brown is about 22; slate (gray) is about 24;
white is about 36; red is about 30; black is about 3; yellow is about 27;
violet is about 16; rose is about 37; and aqua is about 35. Preferably,
however, the sample exhibits the following minimum values: blue is about
64; orange is about 46; green is about 12; brown is about 33; slate (gray)
is about 36; white is about 55; red is about 46; black is about 5; yellow
is about 41; violet is about 25; rose is about 56; and aqua is about 53.
More preferably, the 100 micron sample exhibits a minimum contrast ratio
having the following values for each respectively colored matrix: blue is
about 71; orange is about 51; green is about 14; brown is about 37; slate
is about 40; white is about 61; red is about 51; black is about 6; yellow
is about 46; violet is about 28; rose is about 63; and aqua is about 59.
In a preferred embodiment, a 25 micron thick by 75 mm wide by 180 mm long
sample of the cured matrix, when placed under a clear 150 micron thick
UV-curable coating which is substantially free of chromophores, exhibits a
lightness range, as determined by the means for spectrophotometrically
analyzing, having the following values for each respectively colored
matrix: blue is about 55 to about 80; orange is about 57 to about 82;
green is about 70 to about 95; brown is about 54 to about 79; slate is
about 61 to about 86; white is about 78 to about 98; red is about 46 to
about 71; black is about 60 to about 85; yellow is about 73 to about 98;
violet is about 60 to about 85; rose is about 59 to about 84; and aqua is
about 67 to about 92. More preferably, the 25 micron sample exhibits a
lightness range having the following values for each respectively colored
matrix: blue is about 60 to about 80; orange is about 60 to about 80;
green is about 75 to about 95; brown is about 59 to about 79; slate is
about 66 to about 86; white is about 83 to about 98; red is about 51 to
about 71; black is about 60 to about 80; yellow is about 80 to about 95;
violet is about 65 to about 85; rose is about 62 to about 82; and aqua is
about 72 to about 87. Most preferably, the 25 micron sample exhibits a
lightness range having the following values for each respectively colored
matrix: blue is about 63 to about 75; orange is about 66 to about 77;
green is about 79 to about 90; brown is about 62 to about 74; slate is
about 70 to about 81; white is about 91 to about 98; red is about 55 to
about 66; black is about 67 to about 80; yellow is about 85 to about 93;
violet is about 71 to about 82; rose is about 64 to about 79; and aqua is
about 76 to about 87. These lightness ranges were determined in
essentially the same manner as the hue angles.
In another preferred embodiment, a 25 micron thick by 75 mm wide by 180 mm
long sample of the cured matrix, when placed under a clear 150 micron
thick UV-curable coating which is substantially free of chromophores,
exhibits the following chroma values, as determined by the means for
spectrophotometrically analyzing, for each respectively colored matrix:
blue is greater than about 18; orange is greater than about 48; green is
greater than about 12; brown is greater than about 18; slate is about 0 to
about 10; white is about 0 to about 12; red is greater than about 31;
black is about 0 to about 10; yellow is greater than about 39; violet is
greater than about 8; rose is greater than about 18; and aqua is greater
than about 15. More preferably, the 25 micron sample exhibits the
following chroma values for each respectively colored matrix: blue is
greater than about 28; orange is greater than about 72; green is greater
than about 13.5; brown is greater than about 25; slate is about 0 to about
7; white is about 0 to 11; red is greater than about 48; black is about 0
to about 5; yellow is greater than about 51; violet is greater than about
11; rose is greater than about 21; and aqua is greater than about 19.
These chroma values were determined in essentially the same manner as the
hue angles and lightness values.
The matrix material exhibiting the characteristics described in the
foregoing paragraphs comprises a base resin blend, a photoinitiator or
photoinitiator blend, an opacifier blend and one or more color blends,
such as a pigmented letdown blend. More specifically, the matrix material
is formed from a reactive mixture comprising:
(a) about 85 to about 99.7 percent by weight of a base resin, preferably
about 87 to about 99.7 percent, more preferably about 87 to about 95
percent;
(b) about 0.1 to about 10 percent by weight of a photoinitiator that
absorbs light in the wavelength region above about 400 nm, preferably
about 0.25 to about 7 percent, more preferably about 0.5 to about 6
percent;
(c) about 0.1 to about 10 percent by weight of an opacifier blend,
preferably about 0.1 to about 4 percent, more preferably about 0.5 to
about 3.5 percent, except that for black matrix material the opacifier
blend is optional; and
(d) about 0.1 to about 10 percent by weight of at least one color blend,
preferably 0.5 to about 5 percent of a pigment blend, more preferably
about 0.6 to about 4 percent of a pigment blend;
wherein all of the percentages by weight are based on the total weight of
(a), (b), (c) and (d).
The matrix material typically comprises 1-5 different pigment blends,
depending on the desired final color. Most colors are obtained with one or
two pigment blends. Actual dry pigment compounds, as opposed to other
compounds in a pigment blend, shall be referred to as "pigment compounds."
The base resin may comprise:
(a) about 30 percent to about 80 percent by weight of one or more
acrylated, methacrylated or vinyl functional oligomers with a chemical
backbone based on an aliphatic urethane oligomer or epoxy oligomer, or a
combination thereof, preferably about 40 to about 70 percent, more
preferably about 40 to about 60 percent;
(b) from about 10 percent to about 75 percent by weight, for example about
14 to about 18 percent, preferably from about 10 percent to about 65
percent by weight, of one or more reactive diluent monomers having about 1
to about 5 functional groups, more preferably about 35 to about 45
percent, for example about 40 percent;
wherein the percentages of (a) and (b) by weight are based on the total
weight of (a) and (b).
More preferably, the base resin of the matrix material comprises:
(a) about 40 to about 60 percent by weight of one or more acrylated,
methacrylated or vinyl functional oligomers with a chemical backbone based
on an aliphatic urethane oligomer;
(b) about 35 to about 45 percent by weight of one or more reactive diluent
monomers having about 1 to about 5 acrylate, methacrylate, vinyl ether or
vinyl functional groups, more preferably about 20 to about 25 percent by
weight of isobornyl acrylate and about 35 to about 45 percent of an
isocyanurate acrylate, for example an isocyanurate triacrylate, most
preferably about 35 to about 45 percent of tris-hydroxyethyl isocyanurate
triacrylate; and
wherein all of the percentages of (a) and (b) by weight are based on the
total weight of (a) and (b).
In the present specification all compositional percentages are by weight
unless otherwise indicated.
The photoinitiator is capable of absorbing light in the wavelength region
above about 400 nm. Preferably, the photoinitiator has an absorption value
of at least about 0.1 at 400 nm, typically at least about 1 or 1.5 at 400
nm, when present at a concentration of about 0.1% by weight in a solvent
which does not absorb light of this wavelength, the solution being present
in a container transparent to light of this wavelength and providing a
path length of 1.0 centimeters. Moreover, it may have an absorption value
of greater than about 1 at 325 nm, typically greater than about 2 at 325
nm, when measured under these same conditions. Examples of suitable
solvents include methanol and acetonitrile. The absorption value may be
measured via any commercially available UV-Visible spectrophotometer such
as the Lambda Series available from Perkin Elmer, Shelton, Conn. or the
Cary Series available from Varian, Inc. Mulgrave, Victoria, Australia.
More preferably, the photoinitiator is a bis-acyl phosphine oxide
photoinitiating compound. One or more other photoinitiator compounds may
also be present. While different absorption values have been given, it
must be noted that absorption herein, is defined as absorbing any amount
of light. The threshold for absorption value, unless specifically defined,
is assumed to be limited only by the features of the measuring device.
The opacifier blend may comprise opacifying compounds such as TiO.sub.2,
BaSO.sub.4, ZnO or ZnS, preferably about 40 to about 50 percent of the
weight of the opacifier blend is TiO.sub.2. An opacifier blend is less
preferable when the matrix material is black.
The matrix material may also contain various additives, stabilizers and
release agents. For example, it may contain from about 0.1 percent to
about 10 percent by weight of an additive to provide adequate surface slip
and release. It may also contain from about 0.1 percent to about 2 percent
by weight of stabilizer or antioxidant compounds such as tertiary amines;
hindered amines; organic phosphites; hindered phenols or hydrocinnamates;
propionates and mixtures thereof. Preferably the stabilizer or antioxidant
compounds are selected from the group consisting of hindered phenols,
hydrocinnamates and mixtures thereof.
In a preferred embodiment, the invention comprises an optical fiber ribbon
employing the matrix material above and having at least two optical fibers
in a fixed arrangement, preferably parallel to one another, within the
cured matrix material.
In an alternative embodiment, the invention comprises a process for
preparing an optical fiber ribbon which includes the steps of (1)
mechanically arranging coated and inked optical fibers in a generally
parallel arrangement relative to each other; (2) applying about the fibers
the liquid form of the radiation-curable matrix material; and (3) curing
the matrix, thereby securing said fibers in said arrangement. The curing
may be effected by electron beam irradiation or by ultraviolet
irradiation, preferably the latter.
In another alternative embodiment, the invention comprises a
radiation-curable matrix composition including the ingredients in the
matrix material described above and exhibiting the characteristics listed
above.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A radiation-curable matrix material has been devised to exhibit a number of
important characteristics rendering it useful for affixing coated and
inked or otherwise colored optical fibers in a ribbon configuration. These
characteristics generally include opacity; diversity of coloration;
moisture resistance; solvent resistance; adequate adhesion level; ease of
stripping; resistance to breakout failure; low volatiles content; fast
cure; non-yellowing; tolerance of cabling; thermal, oxidative and
hydrolytic stability, and so forth. The matrix is employed in an optical
fiber ribbon that comprises a plurality of optical fibers in a fixed
arrangement, preferably parallel to one another, within the cured matrix
material. Also disclosed is a process for preparing an optical fiber
ribbon using the aforesaid matrix material which matrix material exhibits
the characteristics as defined below.
Radiation-Curable Matrix Material
The invention relates in part to a radiation-curable matrix material. After
curing, the matrix material preferably produces the following hue angle
ranges, lightness values and chroma values, measured as described below,
for each of twelve colors. In Table 1, Adeq stands for adequate, Pref
stands for preferred and M. Pref stands for most preferred.
TABLE 1
Hue, Lightness and Chroma Values Exhibited by Matrix Material
Chroma
Hue Angle (25 micron film) Lightness (25 micron film) (25
micron film)
Color Adeq. Pref. M. Pref. Adeq. Pref. M. Pref
Pref. M. Pref.
Blue 230-270 230-260 233-250 55-80 60-80 63-75
>18 >28
Orange 55-80 55-75 61-69 57-82 60-80 66-77
>48 >72
Green 120-185 120-150 120-143 70-95 75-95 79-90
>12 >13.5
Brown 35-80 50-80 58-78 54-79 59-79 62-74
>18 >25
Slate 0-360 30-220 69-190 61-86 66-86 70-81 0-10
0-7
White 0-360 85-153 100-138 78-98 83-98 91-98 0-12
0-11
Red 325-50 0-50 19-31 46-71 51-71 55-66
>31 >48
Black 0-360 3-113 18-98 60-85 60-80 67-80 0-10
0-5
Yellow 80-120 90-115 99-112 73-98 80-95 85-93
>39 >51
Violet 270-325 290-325 292-324 60-85 65-85 71-82
>8 >11
Rose 0-22 5-22 7-22 59-84 62-82 64-79
>18 >21
Aqua 184-230 184-210 184-202 67-92 72-87 76-87
>15 >19
The foregoing hue angles, lightness values and chroma values were
determined by analyzing 25 micron thick by 75 mm wide by 180 mm long
samples of the cured matrix material under 150 microns of the clear
secondary coating described in Table 6. These values were analyzed with a
means for spectrophotometrically analyzing. Means for
spectrophotometrically analyzing is limited to using a spectrophotometer
where the samples are measured on top of a white background tile (Hunter
Lab #C2-1186) and the spectrophotometer has the following settings:
Illuminant=C, Observer=2 degrees, Spectral Component=Excluded. All values
are a reported average of a minimum of 3 measurements at different areas
on the film. The hue angle range for red is about 325 to about 50 because
these hue angles lie on a "circle of color" from 0 to 360 degrees. Red
shades exist from 0 to 50 degrees and from 325 to 360 degrees. The
shorthand for this range is 325 to 50 degrees.
The limitations that define a means for spectrophotometrically analyzing do
not, of course, at all limit the ways in which the hue angles, lightness
values and chroma values may be determined. Means for
spectrophotometrically analyzing is limited as above only for purposes of
defining and standardizing the physical characteristics exhibited by the
inventive matrix material. Other means and methods of analyzing the
samples will generate different results. However, such results should form
a pattern of values that corresponds consistently and proportionally with
the values determined by the means for spectrophotometrically analyzing.
After curing, the matrix material also preferably produces the following
minimum contrast ratios and inside degrees of cure, measured as described
below, for each of twelve colors. In Table 2, Adeq stands for adequate,
Pref stands for preferred and M. Pref stands for most preferred.
TABLE 2
Contrast and Cure Exhibited by Matrix Material
Minimum Contrast Ratio Minimum Degree of Cure
(100 micron film) (% RAU - 100 micron film)
Color Adeq. Pref. M. Pref. Adeq. Pref. M. Pref.
Blue 42 64 71 >70% >80% >85%
Orange 30 46 51 >70% >80% >85%
Green 8 12 14 >70% >80% >85%
Brown 22 33 37 >70% >80% >85%
Slate 24 36 40 >70% >80% >85%
White 36 55 61 >70% >80% >85%
Red 30 46 51 >70% >80% >85%
Black 3 5 6 >70% >80% >85%
Yellow 27 41 46 >70% >80% >85%
Violet 16 25 28 >70% >80% >85%
Rose 37 56 63 >70% >80% >85%
Aqua 35 53 59 >70% >80% >85%
A contrast ratio represents the ratio of the largest to the smallest
luminance values of a material or image. The values for the minimum
contrast ratio were determined by curing 100 micron thick by 80 mm wide by
120 mm films on glass plates, removing the films and placing them on a
substrate conforming with ASTM D2805-88 with appropriate white and black
sections and analyzing the samples of the cured matrix material on a model
CS-5 spectrophotometer from Applied Color Systems with the following
settings: Specular Component Excluded, 2 degree observer, C illuminant.
Values for % reflectance were obtained for the film over the white
background and over the black background from 400 to 700 nm at 20 nm
intervals. While contrast ratio is defined as the ratio of the average
reflectance of the film over the black background to the average
reflectance of the film over the white background, as measured as a
percentage (i.e., between 0 and 1.00), the contrast ratio values used
herein, as reported by the CS-5 spectrophotomer, are achieved by
multiplying the contrast ratio by 100 to achieve a number between 0 and
100. A description of the contrast ratio is given in ASTM standard
D2805-88. In determining these values, a modified ASTM D2805-88 was
employed.
By a modified ASTM D2805-88 method is meant a method modified for curing
the films on a glass substrate followed by removing the film and
spectrophotometrically analyzing on top of the appropriate background. The
values were measured on a smooth surface paper chart, e.g., Form 2C
Opacity chart from Leneta Co., Ho-Ho-Kus, N.J., as deemed appropriate by
ASTM D2805-88, section 5.1.2. In contrast, the standard ASTM D2805-88
method includes applying the film directly on the chart and allowing the
film to air dry. However, since the air dry method is inapplicable to the
present invention, the method of applying the film to the substrate has
been modified. The steps used to measure the contrast ratio after the film
has been cured and secured to the substrate remain the same as those of
the measurement procedure portion of ASTM D2805-88. For example, the
substrate upon which the film is measured (after being removed from the
glass substrate) is the substrate specified in ASTM D2805-88.
The values for the minimum degree of inside cure represent the percent
reacted acrylate unsaturation (%RAU). They were determined by using
FTIR-ATR (Fourier Transform Infrared Spectroscopy-Attenuated Total
Reflectance) to analyze samples of the matrix material, as cured on a 6 mm
glass plate with a radiation dose of about 0.2 J/cm.sup.2. The method was
used to determine the %RAU using a Nicolet Magna FTIR bench with Continuum
microscope and a Spectra Tech Infinity Series diamond ATR attachment is
described below.
The Nicolet Magna 860 was used with the following settings: number of
scans=128; resolution=4; gain=4, velocity=1.89; aperture=100; beam
splitter=KBr; and detector=MCT (mercury cadmium telluride). After the
settings have been verified, a background spectrum is obtained by sliding
the ATR objective into alignment slightly above the liquid sample.
Next, the uncured coating sample is prepared and the spectra obtained. For
example, a single drop of liquid coating is placed on a slide. The drop is
aligned below the crystal using a visual objective, then the ATR crystal
is slid back to collect the spectrum. The stage is then raised until the
spectrum appears on the screen. The spectrum is then collected, whereafter
the stage is lowered and the diamond crystal is cleaned with methanol.
Then, a sample of the film prepared above is prepared and its spectrum is
obtained. Such a sample is 100 microns thick, 80 mm wide and 120 mm long.
The film is aligned using the visual objectives (15.times.Reflachromat) to
get the sample close to the objective, whereafter the ATR crystal is swung
underneath. The sample can then be generated and collected.
The measurement is completed by obtaining the peak areas. This may be
accomplished by first, converting the liquid sample spectrum to
absorbance, and using OMNIC software available from Nicolet, or any other
method of calculating peak areas, calculating the areas under the peaks at
1410 cm.sup.-1 and 1520 cm.sup.-1 for both the liquid sample and the film
sample.
Finally, the % RAU is calculated using the following formula:
##EQU1##
The samples were 100 microns thick, 80 mm wide and 120 mm long. The percent
RAU was measured at the bottom surface of these samples. The curing unit
used was a Fusion Systems with a 300 Watt/inch irradiator. A 9 millimeter
diameter D bulb was used. The films were cured at a temperature of
25.degree. C. allowed to condition for about 72 hours away from light at
50+/-10 percent RH and 23+/-2.degree. C. However, in cases where materials
other than acrylates are being cured, such as methacrylates or vinyls, the
FTIR technique is modified for the particular peaks being monitored, but
the resulting calculated percent reacted functional groups remain the same
as used for acrylates.
The matrix material exhibiting the characteristics described above is
comprised of a base resin blend, a photoinitiator or photoinitiator blend,
an opacifier blend and one or more color blends.
More specifically, the matrix material comprises:
(a) about 80 to about 99.7 percent by weight of a base resin, preferably
about 85 to about 99 percent, more preferably about 87 to about 95
percent;
(b) about 0.1 to about 10 percent by weight of a photoinitiator that
absorbs light in the wavelength region above about 400 nm, preferably
about 0.25 to about 7 percent, more preferably about 0.5 to about 6
percent;
(c) about 0.1 to about 10 percent by weight of an opacifier blend,
preferably about 0.1 to about 4 percent, more preferably about 0.5 to
about 3.5 percent, except that for black matrix material the opacifier
blend is optional; and
(d) about 0.1 to about 10 percent by weight of at least one color blend,
preferably about 0.5 to about 5 percent of a pigment blend, more
preferably about 0.6 to about 4 percent of a pigment blend;
wherein all of the percentages by weight are based on the total weight of
(a), (b), (c) and (d).
I. Base Resin
The base resin may comprise:
(a) about 30 percent to about 80 percent by weight of one or more
acrylated, methacrylated or vinyl functional oligomers with a chemical
backbone based on an aliphatic urethane oligomer or epoxy oligomer, or a
combination thereof, preferably about 40 to about 70 percent, more
preferably about 40 to about 60 percent, for example about 48 to about 52
percent;
(b) from about 10 percent to about 75 percent, preferably from about 10
percent to about 65 percent, for example about 14 to about 18 percent,
more preferably about 35 percent to about 45 percent, for example about 40
percent by weight of one or more reactive diluent monomers having about 1
to about 5 functional groups, preferably about 1 to about 5 acrylate,
methacrylate, vinyl ether or vinyl functional groups, still more
preferably about 20 to about 25 percent by weight of isobornyl acrylate
and about 14 to about 18 percent of an isocyanurate acrylate, for example
an isocyanurate triacrylate, most preferably about 14 to about 18 percent
of tris-hydroxyethyl isocyanurate;
wherein the percentages of (a) and (b) by weight are based on the total
weight of (a) and (b).
A most preferred base resin is described in Table 3.
TABLE 3
Preferred Base Resin
Product % Supplier Description
PURELAST 19.26 Polymer Systems Aliphatic Urethane Acrylate
590 Corp. Oligomer
Orlando, FL
EBECRYL 31.28 UCB Chemical Aliphatic Urethane Acrylate
270 Corp. Oligomer
Smyrna, GA
SR-368 16.28 Sartomer Tris-hydroxyethyl Iso-
Exton, PA cynanurate Triacrylate
Isobornyl 23.83 UCB Chemical Isobornyl Acrylate
Acrylate Corp. Monomer
Smyrna, GA
Percent 100.00
Total:
A. The Urethane Acrylate or Epoxy Acrylate Oligomer
Preferably, these oligomers are based on an aliphatic polyether polyol,
which is reacted with an aliphatic polyisocyanate and then acrylated. They
comprise from about 30 percent to about 80 percent by weight of the base
resin.
Examples of suitable urethane acrylate and epoxy oligomers include but are
not limited to PURELAST 586 and 590 series from Polymer Systems
Corporation; PHOTOMER 6008 and 6019, both from Cognis Corporation (Ambler,
Pa.); EBECRYL 264, 270, 4842, all from UCB Chemicals, Radcure Division
(Smyrna, Ga.); CN 120, 934, 983, 990 all from Sartomer Corporation (Exton,
Pa.); and UVE 150 from Croda Resins Ltd. (Belvedere, Kent, England).
B. The Monomer Having 1to 5 Functional Groups
By themselves, typical acrylated urethanes and epoxy acrylate oligomers are
too viscous for matrix materials. These reactive diluent monomers, which
constitute from about 5 to about 65 percent, for example about 45 percent,
by weight of the base resin (based on the total weight of the base resin
ingredients), serve to dilute the matrix formulation. They have about 1 to
about 5 functional groups, preferably about 1 to about 5 acrylate,
methacrylate, vinyl ether or vinyl functional groups. However, all
suitable monomers that react with the urethanes or epoxy oligomers and
that have about 1 to about 5 functional groups may be used.
Monomers are suitable when they do not introduce volatile or extractable
materials into the formulation and do not negatively affect other physical
properties such as modulus, tensile strength, elongation to break,
adhesion to various substrates, cure speed, etc. Such properties are known
in the art. Preferably, the monomer diluent may be capable of lowering the
viscosity of the uncured (liquid) composition to within the range of about
1,000 to about 10,000 cps (centipoises) at 25.degree. C., preferably about
4,000 to about 8,000 cps, as measured by a Brookfield viscometer, Model
LVT, spindle speed #34, at 25.degree. C. If a viscosity higher than about
10,000 cps results, the liquid (uncured) composition including it may
still be useful if certain processing modifications are effected (e.g.,
heating the dies through which the liquid coating composition is applied).
Examples of suitable monomers include but are not limited to isobornyl
acrylate; C.sub.6 -C.sub.12 hydrocarbon diol diacrylates; C.sub.6
-C.sub.12 hydrocarbon diol dimethacrylates; tripropylene glycol
diacrylate; tripropylene glycol dimethacrylate; neopentyl glycol,
diacrylate; neopentyl glycol dimethacrylate; neopentyl glycol propoxylate
diacrylate; neopentyl glycol propoxylate dimethacrylate; neopentyl glycol
ethoxylate diacrylate; neopentyl glycol ethoxylate dimethacrylate;
bisphenol A ethoxylate diacrylate; bisphenol A ethoxylate dimethacrylate;
bisphenol A propoxylate diacrylate; bisphenol A propoxylate
dimethacrylate; phenoxyethyl acrylate; phenoxyethyl methacrylate;
phenoxyethyl ethoxylate acrylate; phenoxyethyl ethoxylate methacrylate;
phenoxyethyl propoxylate acrylate; phenoxyethyl propoxylate methacrylate;
polyethylene glycol nonylphenylether acrylate; polyethylene glycol
nonylphenylether methacrylate; polypropylene glycol nonylphenylether
acrylate; polypropylene glycol nonylphenylether methacrylate; isooctyl
methacrylate; octyl acrylate; octyl methacrylate; decyl acrylate; decyl
methacrylate; isodecyl acrylate; isodecyl methacrylate; lauryl acrylate;
lauryl methacrylate; tridecyl acrylate; tridecyl methacrylate; palmitic
acrylate; palmitic methacrylate; stearyl acrylate; stearyl methacrylate;
cetyl acrylate; cetyl methacrylate; tetrahydrofurfuryl acrylate;
tetrahydrofurfuryl methacrylate; isobornyl acrylate; isobornyl
methacrylate; dicyclopentenyl acrylate; dicyclopentenyl methacrylate;
dicyclopentenyl ethoxylate acrylate; dicyclopentenyl ethoxylate
methacrylate; dicyclopentenyl propoxylate acrylate; dicyclopentenyl
propoxylate methacrylate; N-vinyl amides and mixtures thereof. Most
preferred compounds include isobornyl acrylate, isocyanurate acrylate and
particularly tris-hydroxyethyl isocyanurate triacrylate.
II. The Photoinitiator
The second main component of the matrix material is a photoinitiator.
Preferably, the photoinitiator constitutes a portion of the base resin.
The conceptual separation herein of the photoinitiator and base resin is
primarily for purposes of explication, and it is to be understood that in
practice the photoinitiator and base resin may be combined prior to the
mixing and reaction of the other components of the matrix material. It
should also be understood that Applicant's statement(s) herein that the
photoinitiator comprises a substance is often shorthand for stating that
the base resin comprises a substance which affects or is affected by the
photoinitiating compound and which might otherwise appear in a
photoinitiator "blend."
The photoinitiator is capable of absorbing light in the wavelength region
above about 400 nm. Moreover, it may have an absorption value of greater
than about 1 at 325 nm when present at a concentration of about 0.1% by
weight in a solvent which does not absorb light of this wavelength and a
path length of 1.0 centimeters.
The photoinitiator must provide reasonable cure speed without causing
premature gelation of the matrix composition. Further, the blend must be
thermally stable.
The photoinitiator constitutes about 0.1 to about 10 percent by weight of
the matrix material, preferably about 0.1 to about 4 percent, more
preferably about 0.5 to about 3.5 percent, most preferably about 0.5 to 6
percent. If it exceeds 10 percent, it could interfere with cure near the
bottom of the matrix film. In amounts less than 0.1 percent, however, it
may not be able to adequately cure the outer or middle portions of the
matrix film.
The photoinitiator preferably comprises one or more photoinitiating
compounds. Preferred photoinitiating compounds absorb UV light in the
wavelength region above about 325 nm, preferably above about 400 nm.
Preferred photoinitiating compounds include IRGACURE-369, 819, 907
(2-methyl-1,4-(methyl thio)phenyl-2-morpholino-propanone-1), 1700 and
DAROCUR-4265, all from Ciba Specialty Chemicals (Tarrytown, N.Y.), and
LUCIRIN TPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide); and TPO-L
(2,4,6-trimethylbenzoylethoxyphenylphosphine oxide) (also known as 8893)
from BASF Corporation (Charlotte, N.C.), or
bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. The most
preferred photoinitiating compound is IRGACURE-819, a bis-acyl phosphine
oxide. Preferably, it comprises about 0.5 to about 6 percent of the weight
of the base resin, most preferably about 2.25 percent. One or more other
photoinitiating compounds, such as IRGACURE-184, DAROCUR 1173 and those
listed below, may also be present. Preferably, the other photoinitiating
compound is IRGACURE-184. More preferably, the IRGACURE-184 constitutes
about 0.5 to about 6 percent of the weight of the base resin, most
preferably about 3 percent. However, it should be understood that, in
preferred embodiments of the invention photoinitiating compounds such as
IRGACURE-184 and DAROCUR 1173 are unsuitable to serve as the lone
photoinitiating compound insofar as they do not absorb an adequate amount
of UV light in the wavelength region above about 325 nm, preferably above
about 400 nm. These other photoinitiators can be used in combination with
the preferred photoinitiators, but will not give the desired degree of
cure in the matrix film (%RAU) on their own. Examples of additional
photoinitiating compounds include but are not limited to
hydroxycyclohexylphenyl ketone; hydroxymethylphenylpropanone;
dimethoxyphenylacetophenone;
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one;
4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone; 1-(4-dodecyl
phenyl)-2-hydroxy-2-methylpropan-1-one; diethoxyacetophenone;
2,2-di-sec-butoxy-acetophenone; diethoxyphenyl acetophenone; and mixtures
thereof.
Examples of suitable photoinitiators include at least one photoinitiating
compound selected from the group consisting of bis-acyl phosphine oxide;
hydroxycyclohexylphenyl ketone; hydroxymethylphenylpropanone;
dimethoxyphenylacetophenone; 2-methyl-1,4-(methyl
thio)phenyl-2-morpholino-propanone-1;
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one;
4-(2-hydroxyethyoxy)phenyl-(2-hydroxy-2-propyl)ketone; 1-(4-dodecyl
phenyl)-2-hydroxy-2-methylpropan-1-one; diethoxyacetophenone;
2,2-di-sec-butoxy-acetophenone; diethoxyphenyl acetophenone;
bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide;
2,4,6-trimethylbenzoyldiphenylphosphine oxide;
2,4,6-trimethylbenzoylethoxyphenylphosphine oxide; and mixtures thereof.
A typical photoinitiator comprises bis-acyl phosphine oxide which
constitutes about 0.25 to about 7 percent of the weight of the matrix.
Another typical photoinitiator comprises IRGACURE-819 which constitutes
about 0.5 to about 6 percent, preferably about 2.25 percent, of the weight
of the base resin, optionally further comprising IRGACURE-184 which
constitutes about 0.5 to about 6 percent, preferably about 3 percent, of
the weight of the base resin.
The following Table 3A lists properties of a number of photoinitiators.
TABLE 3A
Absorption Absorption Chemical
Photoinitiator @ 325 nm @ 400 nm Supplier Name
Irgacure 784 >3 2.25 Ciba --
Specialty
Chemicals
Irgacure 819 >2 1.5 Ciba Phenyl bis-
Specialty (2,4,6-tri-
Chemicals methylbenzo-
yl)phosphine
oxide
Irgacure 1850 >3 0.75 Ciba Blend of 50%
Specialty bis(2,6-
Chemicals dimethoxy-
benzoyl)-2,4,4-
trimethyl-
pentylphos-
phine oxide
and 50% 1-
hydroxycyclo-
hexylphenyl
ketone
Irgacure 1300 >2 0.4 Ciba Blend of 30%
Specialty 2-benzyl-2-
Chemicals (N,N-dimethyl-
amino)-1-(4-
morpholino-
phenyl)-1-
butanone and
70% dimeth-
oxyphenyl-
acetophenone.
Irgacure 1800 >2 0.3 Ciba Blend of 25%
Specialty bis(2,6-dimeth-
Chemicals oxybenzoyl)-
2,4,4-trimethyl-
pentylphos-
phine oxide
and 75% 1-
hydroxy-
cyclohexyl-
phenyl ketone
Irgacure 1700 >2 0.3 Ciba Blend of 25%
Specialty bis(2,6-dimeth-
Chemicals oxybenzoyl)-
2,4,4-trimethyl-
pentylphos-
phine oxide
and 75%
hydroxy-
methylphenyl-
propanone
Darocur 4265 1 0.3 Ciba Blend of 50%
Specialty 2,4,6-tri-
Chemicals methylbenzoyl-
diphenyl-
phosphine
oxide and 50%
hydroxy-
methylphenyl-
propanone
Irgacure 907 >2 0.1 Ciba 2-methyl-1,4-
Specialty (methyl thio)-
Chemicals phenyl-2-
morpholino-
propanone
Irgacure 369 >2 0.25 Ciba 2-benzyl-2-
Specialty (N,N-dimethyl-
Chemicals amino)-1-(4-
morpholino-
phenyl)-1-
butanone
All data from Ciba Specialty Chemicals provided in literature titled
"Photoinitiators for UV Curing - Key Products Selection Guide".
Publication Date: 1999
All absorbance values are for the photoinitiator at a concentration of 0.1%
by weight.
Additional photoinitiators with adequate absorption at both 325 and 400 nm
TPO by BASF
TPO-L (8893) by BASF
III. Antioxidants or Acrylated Silicone Additives
The matrix material also may comprise one or more antioxidants or silicone
additives. Preferably, the silicone additives are acrylated silicone
additives. The purposes of adding the silicone additives are for
increasing surface slip and/or improving release of the matrix material
from the colored fibers. Typical silicone acrylates include one or more of
TegoRad 2100, 2250, 2500, and 2700; CoatOSil 3503 and 3509 from 'OSi
Specialties Greenwich, Conn.; Byk 371, UV 3500 and 3530 from Byk Chemie
USA Wallingford Conn.
The preferred antioxidant is Irganox 1035, which is available from Ciba
Specialty Chemicals (Tarrytown, N.Y.). Preferably, it is present in amount
that constitutes about 1 percent of the weight of the matrix material. The
preferred silicone additive is TegoRad 2200, which is available from Tego
Chemie Service (Essen, Germany). Preferably, it is present in amount that
constitutes about 0.1 percent of the weight of the matrix material.
IV. The Opacifier Blend
The matrix material preferably comprises about 0 to about 10 percent by
weight of an opacifier blend. An opacifier blend is less preferable when
the color of the matrix material is black.
The blend may comprise opacifying compounds such as TiO.sub.2, BaSO.sub.4,
ZnO or ZnS, preferably about 40 to about 50 percent by weight of the blend
is TiO.sub.2. A most preferred opacifier blend is described in Table 4.
TABLE 4
Preferred Opacifier (Opaque White Base)
Product % Description Supplier
Preservative 3.00 See Table 5 See Table 5
TITANIUM 45.00 Opacifier/Pigment Kemira, Inc.
DIOXIDE Savannah, GA
600-I
UVITEX OB 0.10 Optical Brightener (2,- Ciba Geigy
2'-(2,5-Thiophene- Hawthorne, NY
diyl)bis(5-tertbutyl-
benzoxazole)
PHOTOMER 11.00 Ethoxylated Cognis Corp.
4028 Bisphenol-A Ambler, PA
Diacrylate Monomer
TPGDA 2.90 Tripropylene Glycol UCB Chemical Corp.
Diacrylate Smyrna, GA
PHOTOMER 37.00 Acrylated Epoxy Lin- Cognis Corp.
3082 seed Oil Oligomer Ambler, PA
FLORSTAB 1.00 Stabilizer (Ester Kromachem USA, Inc.
UV-5 Plasticizer) Irvington, NJ
STABILIZER
Percent Total: 100.00
The opacifier blend may contain a preservative and a stabilizer such as an
ester plasticizer. A preferred preservative is described in Table 5.
TABLE 5
Preferred Preservative
Product % Description Supplier
PHOTOMER 70.00 Acrylated Epoxy Lin- Cognis Corp.
3082 seed Oil Oligomer Ambler, PA
CAO-3 BHT 20.00 2,6-Di-t-butyl-p-cresol PMC Specialties
(Antioxident) Group, Inc., Fords, NJ
TECQUINOL 10.00 Hydroquinone Eastman Chemical
(Stabilizer) Prod., Kingsport, TN
Percent Total: 100.00
V. The Color Blend
The matrix material preferably comprises about 0.01 to about 10 percent by
weight of at least one color blend, preferably a pigment blend, more
preferably about 0.5 to about 5 percent of a pigment blend, most
preferably about 0.6 to about 4 percent of a pigment blend, for example
about 0.9 to about 4 percent of a pigment blend. The matrix colors are
achieved with about 1 to about 5 different color pigment blends, depending
on the desired final color. Most colors are obtained with one or two
pigment blends.
A specific example of a suitable black pigment includes carbon black.
A specific example of a suitable white pigment includes titanium dioxide.
Specific examples of suitable yellow pigments include diarylide yellow and
diazo based pigments.
Specific examples of suitable blue pigments include phthalocyanine blue,
basic dye pigments, and phthalocyanines.
Specific examples of suitable red pigments include anthraquinone (red),
napthole red, monoazo based pigments, quinacridone pigments,
anthraquinone, and perylenes.
Specific examples of suitable green pigments include phthalocyanine green
and nitroso based pigments.
Specific examples of suitable orange pigments include monoazo and diazo
based pigments, quinacridone pigments, anthraquinones and perylenes.
Specific examples of suitable violet pigments include quinacrinode violet,
basic dye pigments and carbazole dioxazine based pigments.
Suitable aqua, brown, gray, and pink pigments can easily be formulated by
combining other colors.
The pigment blends preferably comprise:
(a) about 10 to about 25 percent by weight of one or more pigment
compounds, more preferably about 13 to about 20 percent;
(b) about 0.5 to about 10 percent by weight of tripropylene glycol
diacrylate, more preferably about 1 to about 5 percent;
(c) about 20 to about 40 percent by weight of acrylated epoxy linseed oil,
more preferably about 25 to about 35 percent;
(d) about 0.5 to about 3 percent by weight of epoxy acrylate/triacrylate
oligomer blend stabilizer, more preferably about 1 to about 2 percent; and
(e) optionally about 35 to about 65 percent by weight of a clear secondary
coating (described below), more preferably about 45 to about 55 percent;
wherein these percentages by weight are based on the total weight of (a),
(b), (c), (d) and (e).
More preferably, the pigment blend accounts for about 0.9 to about 4
percent by weight of the matrix material, and comprises:
(a) one or more pigment compounds that constitute about 13 to about 20
percent of the weight of the pigment blend;
(b) tripropylene glycol diacrylate that constitutes about 1 to about 5
percent of the weight of the pigment blend;
(c) acrylated epoxy linseed oil that constitutes about 25 to about 35
percent of the weight of the pigment blend;
(d) a stabilizer blend, comprising epoxy acrylate and triacrylate
oligomers, that constitutes about 1 to about 2 percent of the weight of
the pigment blend; and
(e) a secondary coating that constitutes about 45 to about 55 percent of
the weight of the pigment blend.
Preferably, the secondary coating comprises:
(a) a urethane acrylate oligomer and at least one other acrylate oligomer
that together constitute about 85 to about 98 percent of the weight of the
secondary coating;
(b) a photoinitiator that constitutes about 2 to about 6 percent of the
weight of the secondary coating; and
(c) optionally, an antioxidant that constitutes about 0.5 to about 1.5
percent of the weight of the secondary coating.
More preferably, the secondary coating comprises:
(a) a urethane acrylate oligomer and hexanediol diacrylate monomer that
together constitute about 87 to about 96 percent of the weight of the
secondary coating;
(b) 1-hydroxycyclohexyl phenyl ketone in an amount that constitutes about 3
to about 5 percent of the weight of the secondary coating; and
(c) thiodiethylene(3,5-di-t-butyl-4-hydroxy)hydrocinnamate in an amount
that constitutes about 0.7 to about 1.3 percent of the weight of the
secondary coating.
A preferred secondary coating is described in Table 6.
TABLE 6
Preferred Secondary Optical Coating
Product % Description Supplier
MCWHORTER 88.00 Urethane Acrylate McWhorter Tech-
15-1516 Oligomer -- Hexane- nologies, Carpen-
diol Diacrylate Blend tersville, IL
HDODA 7.00 Hexanediol Diacrylate UCB Chemical
Corp.
Smyrna, GA
IRGACURE 184 4.00 1-Hydroxycyclohexyl Ciba Geigy
Phenyl Ketone Tarrytown, NY
(Photoinitiator)
IRGANOX 1035 1.00 Thiodiethylene (3,5-dit Ciba Geigy
butyl-4-hydroxy)- Tarrytown, NY
hydrocinnamate
(Antioxidant)
Percent Total: 100.00
This secondary coating is not required. Any ultraviolet-curable clear
coating can be used as it is substantially free of chromophores.
Preferably, it is compatible with the pigment dispersion and does not
cause accelerated settling of the pigment.
Preferred pigments, for various colors, are described in Tables 7-16 below.
TABLE 7
Preferred Blue Pigment Letdown (No. 1)
Product % Description Supplier
SUNFAST 18.50 Phthalocyanine Blue Sun Chem.
BLUE GS Pigment (green shade) Cincinnati, OH
TPGDA 2.50 Tripropylene Glycol UCB Chemical Corp.
Diacrylate Smyrna, GA
PHOTOMER 27.75 Acrylated Epoxy Lin- Cognis Corp.
3082 seed Oil Oligomer Ambler, PA
FLORSTAB 1.25 Epoxy Acrylate/ Kromachem USA, Inc.
UV-1 Triacrylate Oligomer Irvington, NJ
Blend (Stabilizer)
Secondary 50.00 See Table 6
Coating
Percent Total: 100.00
TABLE 8
Preferred Blue Pigment Letdown (No. 2)
Product % Description Supplier
CHROMOFINE 18.50 Phthalocyanine Blue Diacolor-Pope
BLUE HS-4 Pigment (red shade) Clifton, NJ
TPGDA 2.25 Tripropylene Glycol UCB Chemical
Diacrylate Corp.
Smyrna, GA
PHOTOMER 28.00 Acrylated Epoxy Lin- Cognis Corp.
3082 seed Oil Oligomer Ambler, PA
FLORSTAB 1.25 Epoxy Acrylate/ Kromachem USA,
UV-1 Triacrylate Oligomer Inc.
Blend (Stabilizer) Irvington, NJ
Secondary 50.00 See Table 6
Coating
Percent Total: 100.00
TABLE 9
Preferred Orange Pigmented Letdown
Product % Description Supplier
GRAPHTOL 17.50 C.I. Pigment Orange 13 Clariant Corp.
ORANGE GPS (Disazopyrazolone) Charlotte, NC
TPGDA 5.25 Tripropylene Glycol UCB Chemical
Diacrylate Corp.
Smyrna, GA
PHOTOMER 26.00 Acrylated Epoxy Linseed Cognis Corp.
3082 Oil Oligomer Ambler, PA
FLORSTAB 1.25 Epoxy Acrylate/Triacrylate Kromachem
UV-1 Oligomer Blend (Stabilizer) USA, Inc.
Irvington, NJ
Secondary 50.00 See Table 6
Coating
Percent Total: 100.00
TABLE 10
Preferred Yellow Pigmented Letdown
Product % Description Supplier
SANDORIN 17.50 C.I. Pigment Yellow 155 Clariant Corp.
YELLOW 4G (Disazo) - Green Shade Charlotte, NC
TPGDA 5.25 Tripropylene Glycol UCB Chemical
Diacrylate Corp.
Smyrna, GA
PHOTOMER 26.00 Acrylated Epoxy Linseed Cognis Corp.
3082 Oil Oligomer Ambler, PA
FLORSTAB 1.25 Epoxy Acrylate/Triacrylate Kromachem
UV-1 Oligomer Blend (Stabilizer) USA, Inc.
Irvington, NJ
Secondary 50.00 See Table 6
Coating
Percent Total: 100.00
TABLE 11
Preferred Red Pigmented Letdown (No. 1)
Product % Description Supplier
GRAPHTOL 16.50 4-[2,5-Dichloro-4-Hy- Clariant Corp.
FAST RED droxy-N-(2-Methyl- Charlotte, NC
2GLD phenyl)]-2-Naphthalene-
carboxamide
TPGDA 4.75 Tripropylene Glycol UCB Chemical
Diacrylate Corp.
Smyrna, GA
PHOTOMER 27.50 Acrylated Epoxy Linseed Cognis Corp.
3082 Oil Oligomer Ambler, PA
FLORSTAB 1.25 Epoxy Acrylate/Triacrylate Kromachem
UV-1 Oligomer Blend (Stabilizer) USA Inc.
Irvington, NJ
Secondary 50.00 See Table 6
Coating
Percent Total: 100.00
TABLE 12
Preferred Red Pigmented Letdown (No. 2)
Product % Description Supplier
GRAPHTOL 16.50 C.I. Pigment Red 210 Clariant Corp.
RED NFB Charlotte, NC
TPGDA 4.75 Tripropylene Glycol UCB Chemical
Diacrylate Corp.
Smyrna, GA
PHOTOMER 27.50 Acrylated Epoxy Linseed Cognis Corp.
3082 Oil Oligomer Ambler, PA
FLORSTAB 1.25 Epoxy Acrylate/Triacrylate Kromachem
UV-1 Oligomer Blend (Stabilizer) USA, Inc.
Irvington, NJ
Secondary 50.00 See Table 6
Coating
Percent Total: 100.00
TABLE 13
Preferred Red Pigmented Letdown (No. 3)
Product % Description Supplier
SANDORIN 16.50 N,N'-(2,5-dichloro-1,4- Clariant Corp.
RED phenylene)bis[4-[2,5- Charlotte, NC
BN dichlorophenyl)azo]-3-
hydroxy-2-
Naphthalene-
carboxamide
TPGDA 4.75 Tripropylene Glycol UCB Chemical
Diacrylate Corp.
Smyrna, GA
PHOTOMER 27.50 Acrylated Epoxy Linseed Cognis Corp.
3082 Oil Oligomer Ambler, PA
FLORSTAB 1.25 Epoxy Acrylate/Triacrylate Kromachem
UV-1 Oligomer Blend (Stabilizer) USA, Inc.
Irvington, NJ
Secondary 50.00 See Table 6
Coating
Percent Total: 100.00
TABLE 14
Preferred Black Pigmented Letdown
Product % Description Supplier
SPECIAL 18.50 Carbon Black Degussa Ridgefield
BLACK Park, NJ
350
TPGDA 1.25 Tripropylene Glycol UCB Chemical
Diacrylate Corp. Smyrna, GA
PHOTOMER 28.50 Acrylated Epoxy Cognis Corp.
3082 Linseed Oil Oligomer Ambler, PA
FLORSTAB 1.75 Epoxy Kromachem USA,
UV-1 Acrylate/Triacrylate Inc.
Oligomer Blend Irvington, NJ
(Stabilizer)
Secondary 50.00 See Table 6
Coating
Percent Total: 100.00
TABLE 15
Preferred Violet Pigmented Letdown
Product % Description Supplier
CARBAZOLE 14.00 C.I. Pigment Violet 23 Sun Chemical
VIOLET Cincinnati, OH
246-0487
TPGDA 1.75 Tripropylene Glycol UCB Chemical
Diacrylate Corp.
Smyrna, GA
PHOTOMER 33.00 Acrylated Epoxy Linseed Cognis Corp.
3082 Oil Oligomer Ambler, PA
FLORSTAB 1.25 Epoxy Kromachem,
UV-1 Acrylate/Triacrylate USA, Inc.
Oligomer Blend Irvington, NJ
(Stabilizer)
Secondary 50.00 See Table 6
Coating
Percent Total: 100.00
TABLE 16
Preferred Green Pigmented Letdown
Product % Description Supplier
PHTHALO 18.50 Phthalocyanine Green Sun Chemical
GREEN BS Pigment (Blue Shade) - Cincinnati, OH
C.I. Pigment Green 7
TPGDA 2.00 Tripropylene Glycol UCB Chemical
Diacrylate Corp.
Smyrna, GA
PHOTOMER 28.25 Acrylated Epoxy Linseed Cognis Corp.
3082 Oil Oligomer Ambler, PA
FLORSTAB 1.25 Epoxy Acrylate/Triacrylate Kromachem
UV-1 Oligomer Blend USA, Inc.
(Stabilizer) Irvington, NJ
Secondary 50.00 See Table 6
Coating
Percent total: 100.00
While the color blends have been disclosed in this application by reference
to the details of preferred pigments, any colored inorganic or organic
material (be it pigment, dye, ink or other substance) will suffice so long
as it can, in combination with a material of sufficient opacity, enable a
fiber optic matrix, ribbon or coating material to exhibit the properties
listed in Tables 1 and 2.
VI. Stabilizers
The matrix material may include from about 0.1 percent to about 2 percent
by weight of a stabilizer or antioxidant. A desirable property of such
compounds includes non-migration (probably enhanced by low polarity). Such
compounds include tertiary amines; hindered amines; organic phosphites;
hindered phenols; hydrocinnamates; propionates; and mixtures thereof.
Preferably such compounds include hindered phenols; hydrocinnamates;
propionates; and mixtures thereof. More specific examples include
diethylethanolamine; trihexylamine;
octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate;
thiodiethylene bis(3,5-di-tert-butyl-4-hydroxy)hydrocinnamate; and
tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane. A
preferred compound is thiodiethylene
bis(3,5-di-tert-butyl-4'-hydroxy)hydrocinnamate, such as IRGANOX 1035,
from Ciba-Geigy Corporation, Ardsley, N.Y.
The Optical Fiber Ribbon Assembly
The invention further relates to an optical fiber ribbon assembly. The
ribbon assembly generally comprises a plurality of coated, inked optical
fibers held in a fixed relationship (e.g., in a parallel and planar or
other prescribed arrangement), and the radiation-curable matrix material
described above, in which the fibers are embedded. The matrix material
remains adhered to the fibers during use but is easily strippable
therefrom without substantially damaging the integrity of an ink layer or
otherwise colored layer on the coated optical fibers. One kind of ribbon
structure, and a cable made from such ribbon, is described in U.S. Pat.
No. 3,411,010 to Gendhr et al., which is incorporated herein by reference.
The optical fibers which are part of the ribbon are those known in the art
which are singly or dually coated before being bonded in the matrix
material, and which contain an ink layer or otherwise colored layer on
their outermost surface, rendering each distinguishable from other fibers
in the ribbon. This outermost layer may be achieved either by adding a
colored material to the secondary coating on the fiber or by applying an
ink layer on top of a primary and secondary coated fiber. The optical
fibers which are coated may comprise, for example, a glass core and a
glass cladding layer. The core, for example, may comprise silica doped
with oxides of germanium or phosphorus, and the cladding may comprise a
pure or doped silicate such as a fluorosilicate. Alternatively, the fibers
may comprise a polymer clad silica glass core. Examples of such polymer
cladding include organosiloxanes such as polydimethylsiloxane and
fluorinated acrylic polymer.
The fiber coatings are of the type known in the art and preferably are
cured with ultraviolet light. The coating compositions may comprise a
single or a dual layer and often contain cured acrylate or methacrylate
components such as urethane diacrylates. A suitable second fiber coating
may comprise an aromatic polyester urethane acrylate; vinyl pyrrolidone;
ethoxyethoxyethylacrylate; photoinitiator; and stabilizer.
As discussed earlier, in order for the optical fiber ribbons to be spliced
in a reasonably easy manner, it is desirable to identify the individual
fibers by color coding them.
It is possible to add a coloring agent to the outermost fiber coating
layer; however, it is more efficacious to ink over the optical fiber
coatings' ink-containing layers by any means known in the art. The applied
ink composition may be variable in nature but generally is comprised of
radiation-curable oligomers and monomers with acrylate, methacrylate,
vinyl, or vinyl ether functional groups and contains a dispersion of one
or more organic and/or inorganic pigment compounds of the general types
described above in sections IV and V of the Description of Preferred
Embodiments. Alternatively, the applied ink composition is vinylic and may
comprise, for example, one or more organic or inorganic pigments; a vinyl
copolymer; synthetic silica; and an organic solvent. The precise nature of
the ink composition may dictate the amounts and nature of the
adhesion-affecting components in the matrix.
Process for Preparing an Optical Fiber Ribbon
The invention comprises, in a further aspect, a process for preparing an
optical fiber ribbon. Broadly, the process comprises mechanically
arranging coated and inked fibers in a desired (i.e., generally planar and
generally parallel) configuration; applying the aforesaid matrix material
about the fibers; and curing.
A suitable but non-limiting method for applying the matrix material to the
fibers is as follows. Optical fibers which have been coated and colored or
otherwise inked in the manner described above or in any manner known in
the art may be used. The optical fibers may be mechanically arranged in
the desired configuration (e.g., in a generally parallel and planar
disposition relative to each other). The fibers may be held in the desired
configuration, for example, by taping or otherwise holding the ends
together. The matrix material may be applied about the fibers by any
conventional means, with the most common application method being to
process the colored fibers through a cup of the matrix material and
subsequently pass the coated structure through a die to give uniform
dimension to the ribbon prior to curing via radiation. Other means of
application such as dipping the fibers into a vat of the material or
pouring the material thereupon may be employed, but these are not
preferred since the ribbon geometry is not well controlled using these
methods. Once the matrix has been applied substantially uniformly about
the fibers, it may be radiation cured, preferably by ultraviolet light.
Alternatively, matrix material may be applied and cured and then the
composite may be flipped over, more matrix material applied thereto, and
the matrix again cured as above. The resulting ribbon contains the fibers
bonded and secured in the desired disposition.
The adhesive bond of the cured matrix material to the coated and inked
fibers may be adjusted by incorporation into the uncured matrix material
of a component capable of increasing the adhesive bonds.
Radiation-Curable Composition
The invention further comprises a composition used for forming a
radiation-curable ribbon matrix in which at least two coated and colored
optical fibers are embedded. The composition includes the ingredients and
components of the matrix material described above. After curing, the
composition also exhibits substantially the same characteristics, such as
hue angle, contrast ratio, inside degree of cure, lightness ranges and
chroma values.
Coatings for Other Substrates
Although the matrix material has been exemplified above as a matrix
material for coated and inked optical fibers, it is useful in any
embodiment in which a substrate, especially a flexible and ink-covered
substrate, needs to be coated or bound and wherein the coating must adhere
well to the substrate.
Examples of such substrates include, but are not limited to, glass, metal
and plastic. For example, the matrix material may be used as a release
coating for a glass or plastic substrate having a logo printed thereon, as
used in electronics and other industries, to identify a supplier. Indeed,
it may be useful in any embodiment where it is desirable to temporarily
protect a printed surface. For example, a logo may be protected during
shipping with a release coating of the matrix, which may be removed by the
customer.
EXAMPLES
The following exemplary matrix material formulations in the Tables 17 and
18 below serve to further illustrate the invention. Each formulation
exhibits characteristics that fall within the ranges for the respective
colors defined in Tables 1 and 2.
All parts and percentages are by weight of the total matrix composition
described in that example, including all components. Each formulation
comprises the following components: the base resin blend of Table 3, a
photoinitiator, the opacifier blend of Table 4, the preservative blend of
Table 5 and one or more pigment blends. Each individual pigment blend
comprises the secondary coating of Table 6 and one of the pigmented
letdown blends of Tables 7-16. While some of the individual components
contain preservatives, stabilizers and other such additives, no such
optional ingredients were added directly to the compositions as components
in themselves. Such optional components, however, may be necessary for use
if the exemplified matrix materials are to meet the rigorous requirements
for commercially acceptable matrices for optical glass fiber ribbons.
In Tables 17 and 18 the photoiniator composition includes 3.0 percent of
IRGACURE 184 photoiniator, 2.25 percent of IRGACURE 819 photoinitiator,
1.0 percent IRGANOX 1035 antioxidant, 0.1 percent TegoRad 2200 silicone
acrylate, and the remainder is isobornyl acrylate.
TABLE 17
Full Matrix Formulations
Blue Orange Green Brown Slate White
Components Matrix Matrix Matrix Matrix Matrix Matrix
Base Resin 88.515% 87.89% 89.606% 88.922% 89.05%
87.57%
Photoinitiator 9.13 9.06 9.242 9.172 9.18 9.03
Opacifier 1.350 0.550 0.160 0.450 1.500 3.400
Antioxidant
Blue No. 1 Pig. 0.810 0.288 0.040
Blue No. 2 Pig. 0.195
Orange Pig. 2.500 0.600
Yellow Pig. 0.704 0.350
Red No. 2 Pig.
Red No. 1 Pig. 0.250
Black Pig. 0.256 0.230
Percent Total: 100.000 100.000 100.000 100.000 100.000 100.000
TABLE 18
Full Matrix Formulations
Red Black Yellow Violet Rose Aqua
Components Matrix Matrix Matrix Matrix Matrix Matrix
Base Resin 87.48% 90.034% 87.79% 89.743% 88.47% 88.52%
Photoinitiator 9.02 9.286 9.06 9.256 9.13 9.13
Opacifier 0.500 0.900 0.634 1.600 1.800
Red No. 1 Pig. 3.000
Black Pig. 0.600
Violet Pig. 0.080 0.300
Yellow Pig. 2.250
Red No. 2 Pig. 0.067
Red No. 3 Pig. 0.800
Blue No. 1 Pig. 0.150
Green Pig. 0.400
Percent Total: 100.000 100.000 100.000 100.000 100.000 100.000
While the invention has been disclosed in this patent application by
reference to the details of preferred embodiments of the invention, it is
to be understood that this disclosure is intended in an illustrative
rather than in a limiting sense, as it is contemplated that modifications
will readily occur to those skilled in the art within the spirit of the
invention and the scope of the appended claims.
* * * * *
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