Title: Covering composition for optical fiber and covered optical fiber
Abstract: According to the present invention, there is provided a covering composition for optical fiber comprising (A) an unsaturated polyester oligomer having substantially two or more (meth)acryloyl group in a molecule wherein a glass transition temperature of a cured substance thereof is 100 to 350° C.; (B) at least one oligomer selected from the group consisting of the following components: (B-a) epoxy modified (meth)acrylate oligomer, (B-b) polyether polyol modified (meth)acrylate oligomer, and (B-c) urethane polyether polyol modified (meth)acrylate or urethane polyester polyol modified (meth)acrylate; and (C) a photopolymerization initiator, as essential components. The cured material has highly elasticity and is superior in the heat stability, and as a result, the present invention provides the superior covered optical fiber with well balanced heat stability of the optical transmission properties and flexibility.
Patent Number: 6,993,231 Issued on 01/31/2006 to Naruse, et al.
| Inventors:
|
Naruse; Keisuke (Hiratsuka, JP);
Higuchi; Takahiro (Hiratsuka, JP);
Tamura; Koichi (Hiratsuka, JP)
|
| Assignee:
|
Kansai Paint Co., Ltd. (Hyogo, JP)
|
| Appl. No.:
|
760350 |
| Filed:
|
January 21, 2004 |
Foreign Application Priority Data
| Jan 22, 2003[JP] | 2003-013467 |
| Current U.S. Class: |
385/128; 427/163.1 |
| Current Intern'l Class: |
G02B 6/02 (20060101) |
| Field of Search: |
385/128
427/163.1
|
References Cited [Referenced By]
U.S. Patent Documents
| 6023547 | Feb., 2000 | Tortorello.
| |
| 6514619 | Feb., 2003 | Shimada et al.
| |
| 6760086 | Jul., 2004 | Hattori et al.
| |
| 2003/0060563 | Mar., 2003 | Kai et al.
| |
| 2004/0232563 | Nov., 2004 | Sumi et al.
| |
| Foreign Patent Documents |
| 6-74307 | Sep., 1994 | JP.
| |
| 2525177 | May., 1996 | JP.
| |
Primary Examiner: Healy; Brian
Assistant Examiner: Blevins; Jerry Martin
Attorney, Agent or Firm: Sughrue Mion, PLLC
Claims
What is claimed is:
1. A covering composition for optical fiber comprising as essential components
(A) an unsaturated polyester oligomer having substantially two or more (meth)acryloyl
groups in a molecule wherein a glass transition temperature of a cured substance
thereof is 100 to 350° C.;
(B) at least one oligomer selected from the group consisting of the following components:
(B-a) epoxy modified (meth)acrylate oligomer,
(B-b) polyether polyol modified (meth)acrylate oligomer, and
(B-c) urethane polyether polyol modified (meth)acrylate or urethane polyester
polyol modified (meth)acrylate; and
(C) a photopolymerization initiator.
2. The covering composition for optical fiber according to claim 1, comprising
a silicone additive (D) in the composition.
3. The covering composition for optical fiber according to claim 1, comprising
a photopolymerizable unsaturated compound (E) in the composition.
4. A covered optical fiber having a covering layer comprising a cured material
of the covering composition for optical fiber of claim 1 on the periphery of the
optical fiber.
5. A covered optical fiber comprising a primer covering layer, an ink covering
layer and a matrix covering layer sequentially laminated on the periphery of the
optical fiber wherein any one of the primer covering layer, the ink covering layer
and the matrix covering layer comprises a cured material of the covering compositions
for optical fiber of claim 1.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a covering composition for optical fiber with
superior elastic modulus and heat stability as well as a covered optical fiber
using the same.
2. Description of the Related Art
In the advanced information society, the use of an optical communication system
using glass fiber as information transmission means is rapidly beginning, since
glass fiber has such advantages as less optical transmission loss and good flexibility
as well as reduced weight. Generally, a covered optical fiber comprising a primer
covering layer composed of a primary layer and a secondary layer, an ink covering
layer and a matrix covering layer sequentially laminated on the surface, is used
as a glass fiber for optical transmission. A photo-curing covering composition
is known as covering material.
Recently, with the increase in the construction of optical fiber, thinning
of the covered layer has been progressed in order to obtain high density mounting
and to reduce the cost. According to such the circumstance, it is required for
the covering material to have high elastic modulus for maintaining sufficient physical
properties with a thin film.
Japanese Patent Publication No. 6-74307-B discloses a covering composition
for optical fiber that provides a cured material with a specific Young's modulus
at ordinary temperature as well as low temperature-dependency of Young's modulus.
The composition comprises (a) a polymer obtained by adding a diol having molecular
chain of a specific structure to a diisocyanate compound, and then reacting a reaction
product thus obtained with (meth)acrylic compound having a hydroxyl group, (b)
a monomer comprising a bridge alicyclic hydrocarbon compound having two or more
ethylenic unsaturated groups and two or more aliphatic rings in a molecule, and
(c) a polymerization initiator.
Japanese Patent Publication No. 2525177-B discloses a covering composition
for optical fiber that provides cured material that has low temperature-dependency
of Young's modulus, superior elongation-after-fracture-properties and reduces a
transmission loss of the optical fiber. The composition comprises (A) urethane
di(meth)acrylate having a number average molecular weight of 1000 to 15000 and
(B) urethane di(meth)acrylate having a number average molecular weight of 800 or less.
However, such a problem occurs that a covered film formed of conventional
covering materials suffers great film deformation accompanying temperature change,
resulting in deterioration of optical transmission property of the optical fiber.
Further, since a fiber covered with the film with a larger blend ratio of the covering
material has reduced flexibility, it is difficult to well balance heat stability
and flexibility.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a covered optical fiber which
has sufficient flexibility and superior heat-stable with respect to optical transmission property.
Another object of the present invention is to provide a covering composition
for optical fiber, which can provide such a covered optical fiber and is able to
form cured materials for covering material with superior elastic modulus and heat stability.
The inventors of the present invention have studied extensively in order to achieve
the above objects, and as a result, found that a covering material having superior
elastic modulus and heat stability could be obtained by using a specific oligomer,
and completed the present invention.
According to a first aspect of the present invention, there is provided
a covering composition for optical fiber comprising as essential components
(A) an unsaturated polyester oligomer having substantially two or more (meth)acryloyl
groups in a molecule wherein a glass transition temperature of a cured substance
is 100 to 350° C.;
(B) at least one oligomer selected from the group consisting of the following components:
- (B-a) epoxy modified (meth)acrylate oligomer,
- (B-b) polyether polyol modified (meth)acrylate oligomer, and
- (B-c) urethane polyether polyol modified (meth)acrylate or urethane
polyester polyol modified (meth)acrylate; and
(C) a photopolymerization initiator.
According to a second aspect of the present invention, there is provided
the covering composition for optical fiber of the first aspect comprising a silicone
additive (D) in the composition hereinbefore.
According to a third aspect of the present invention, there is provided
the covering composition for optical fiber of any of the aspects comprising a photopolymerizable
unsaturated compound (E) in the composition hereinbefore.
According to a fourth aspect of the present invention, there is provided
a covered optical fiber having a covering layer comprising a cured material of
any of the covering compositions for optical fiber on the periphery of the optical fiber.
According to a fifth aspect of the present invention, there is provided
that a covered optical fiber comprising a primer covering layer, an ink covering
layer and a matrix covering layer sequentially laminated on the periphery of the
optical fiber, wherein any one of the primer covering layer, the ink covering layer
and the matrix covering layer comprises a cured material of any of the covering
compositions for optical fiber.
According to the present invention, a covering composition that cures rapidly
and can provide a highly elastic and superiorly heat stable cured material can
be provided. As a result, a covered optical fiber well-balanced between heat stability
with respect to optical transmission property and flexibility can be provided.
DETAILED DESCRIPTION OF THE INVENTION
Preferable embodiments of the present invention will be explained hereinbelow
in detail.
At first, the covering composition for optical fiber of the present invention
will be explained.
The covering composition for optical fiber of the present invention comprises
as essential components:
(A) an unsaturated polyester oligomer having substantially two or more (meth)acryloyl
groups in a molecule wherein a glass transition temperature of a cured substance
thereof is 100 to 350° C. (hereinafter sometimes designates as "oligomer (A)");
(B) at least one oligomer selected from the group consisting of the following
components (hereinafter sometimes designates as "oligomer (B)"):
(B-a) epoxy modified (meth)acrylate oligomer (hereinafter sometimes designates
as "oligomer (B-a)"),
(B-b) polyether polyol modified (meth)acrylate oligomer (hereinafter sometimes
designates as "oligomer (B-b)"), and
(B-c) urethane polyether polyol modified (meth)acrylate or urethane polyester
polyol modified (meth)acrylate (hereinafter sometimes designates as "oligomer (B-c)"); and
(C) a photopolymerization initiator.
[Oligomer (A)]
The oligomer (A) is an unsaturated polyester having substantially 2 or more,
preferably 3 or more, more preferably 3 to 6 (meth)acryloyl groups in a molecule.
The glass transition temperature of the cured material is within a range of 100
to 350° C., preferably within a range of 200 to 350° C., and more preferably
within a range of 200 to 300° C.
When the glass transition temperature becomes lower than 100° C., tolerance
to high temperature or warm water of the covering film is lowered, and on the contrary,
when the glass transition temperature becomes higher than 350° C., the physical
property of the covering film becomes rigid excessively, lowering the flexibility.
The glass transition temperature in the present invention is obtained by measuring
the maximum tan δ obtained from the dynamic viscoelastic spectrum of the
film prepared by photo-curing oligomer (A) to which a photopolymerization initiator
is added.
The number average molecular weight of the oligomer (A) is preferably within
a range of 500 to 3000, more preferably within a range of 500 to 2000, and most
preferably within a range of 1000 to 2000.
When the number average molecular weight of the oligomer (A) is too low, the
flexibility of the covering film decreases due to excessive crosslinking density,
and on the contrary, when the number average molecular weight of the oligomer (A)
is too high, the tolerance to high temperature of the covering film decreases due
to lowered crosslinking density.
The preferably oligomer (A) is an oligomer satisfying the above condition and
conventionally known oligomers can be properly selected and used.
Examples of the oligomer (A) are a reaction product of polyester polyol
and (meth)acrylate having a carboxyl group (comprising (meth)acrylic acid); a reaction
product of polyester polycarboxylic acid and (meth)acrylate having a hydroxyl group;
a reaction product of polyester having a hydroxyl group and a carboxyl group and
(meth)acrylate having a carboxyl group (comprising (meth)acrylic acid) and/or (meth)acrylate
having a hydroxyl group; and a reaction product of polyester polycarboxylic acid
and (meth)acrylate having an epoxy group.
Such reaction product preferably has the construction represented by the following
general formula:
##STR1##
wherein A is a group having a (meth)acryloyl group, X is a unit derived from
a polyalcohol component constructing polyester, Y is a unit derived from a polybasic
acid component constructing polyester, and n is an integer of one or more. A may
be a plurality of species, and when Y has 3 or more acid groups, these may be bound
with Y. X may be a plurality of species, and all X may not be bound with A. Y may
be a plurality of species, and when Y has 3 or more acid groups, Y may have a polyester
branched chain and may be bound with A. Further, A may be directly bound with Y
in the terminal to form an oligomer chain terminal.
Examples of the polyalcohol component are: polyalcohol components such as
ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butandiol, 1,5-pentanediol,
3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol,
triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol,
tripropylene glycol, bis(hydroxyethoxy)benzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol,
bisphenol A, hydrogenated bisphenol A and trimethylolpropane; addition products
of said polyalcohol component and alkylene oxide such as ethylene oxide or propylene
oxide; caprolactone modified polyols prepared by reacting said polyalcohol component
or said alkylene oxide addition product with caprolactone; and polyester modified
polyols prepared by reacting said polyalcohol component or said alkylene oxide
addition product, caprolactone and polybasic acid component hereinbelow.
Examples of the polybasic acid component are succinic acid, adipic acid,
azelaic acid, sebacic acid, dodecanedicariboxylic acid, maleic anhydride, fumaric
acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic
acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic
acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid,
1,2-bis(phenoxy)ethane-p,p′-dicaroboxylic acid, trimellitic acid, or polyester
obtained by a dehydration condensation reaction or transesterification of a polybasic
acid component of anhydrides or ester forming derivatives of the above various
dicarboxylic acids.
Examples of the (meth)acrylate containing a hydroxyl group are 2-hydroxylethyl
acrylate, 2-hydroxylethyl methacrylate, 3-hydroxylpropyl acrylate and 3-hydroxylpropyl methacrylate.
Examples of the (meth)acrylate containing carboxyl group (comprising (meth)acrylic
acid) are acrylic acid and methacrylic acid.
Examples of the (meth)acrylate containing an epoxy group are glycidylacrylate
and glycidylmethacrylate.
The above mentioned polyester polyol can be produced, for example, by a conventionally
known reaction method with blending a more excessive amount of the polyalcohol
component than the polybasic acid component (i.e. blending much more the hydroxyl
group than the acid group).
The above mentioned polyester polycarboxylic acid can be produced, for example,
by the conventionally known reaction method with blending smaller amount of the
polyalcohol component than the polybasic acid component (i.e. blending much more
the acid group than the hydroxyl group).
The above mentioned polyester containing a hydroxyl group and a carboxyl group
can be produced, for example, by a conventionally known reaction method wherein
the polyalcohol component reacts with the polybasic acid component with maintaining
functional groups of both components.
The polyester can be produced with a conventionally known method wherein the
reaction is conducted so that the oligomer (A) component can be produced within
the range of the glass transition temperature hereinabove described and within
the range of the number average molecular weight.
[Oligomer (B)]
The oligomer (B) is a compound having substantially one or more, preferably 2
or more, more preferably 2 to 3 (meth)acryloyl group in a molecule. The number
average molecular weight of the oligomer (B) is preferably within a range of 300
to 2000, more preferably within a range of 500 to 2000, and most preferably within
a range of 750 to 1500. When the number average molecular weight of the oligomer
(B) is too low, the flexibility of the covering film is decreases and on the contrary,
when the number average molecular weight of the oligomer (B) is too high, the tolerance
to high temperature is decreases due to softening of the covering film.
[Oligomer (B-a)]
As for the oligomer (B-a), the compound produced by reacting the epoxy compound
or the epoxy resin having one or more, preferably 2 or more epoxy groups in a molecule
with the (meth)acrylate monomer having a functional groups reacting with the epoxy
groups (comprising (meth)acrylic acid) can be used. A blending ratio for reacting
both components (epoxy group of the epoxy compound or the epoxy resin/functional
groups of the (meth)acrylate monomer) is preferably within range of 0.8 to 1.2,
more preferably 0.9 to 1.1.
Examples of the epoxy compound or the epoxy resin are conventionally known
aromatic epoxy compound, alicyclic epoxy compound and aliphatic epoxy compound.
Examples of the aromatic epoxy compound are: monofunctional epoxy compound
such as phenylglycidyl ether; polyphenol having at least one aromatic ring or polyglycidyl
ether of alkylene oxide additive thereof (e.g. glycidyl ethers produced by reaction
of epichlorohydrin with bisphenol compound such as bisphenol A, tetrabromobisphenol
A, bisphenol F and bisphenol S or alkylene oxide (such as ethylene oxide, propylene
oxide and butylene oxide) additive of bisphenol compound and epichlorohydrin);
novolac epoxy resins (e.g. phenol-novolac epoxy resin, cresol-novolac epoxy resin,
brominated phenol-novolac epoxy resin, etc.); and tris phenol methane triglycidyl ether.
Examples of the alicyclic epoxy compound are 4-vinylcyclohexene monoepoxide,
norbornene monoepoxide, limonene monoepoxide, 3,4-epoxycychlorhexylmethyl-3,4-epoxycyclohexane
carboxylate, bis-(3,4-epoxycyclohexylmethyl)adipate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexanone-m-dioxane,
bis(2,3-epoxycyclopentyl)ether, 2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]hexafluoropropane
and BHPE-3150 (Daicel Chemical Ind. Ltd., alicyclic epoxy resin).
Examples of the aliphatic epoxy compound are 1,4-butanediol diglycidyl ether,
1.6-hexanediol diglycidyl ether, ethylene glycol diglycidyl ether, ethylene glycol
monoglycidyl ether, propylene glycol diglycidyl ether, propylene glycol monoglycidyl
ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether,
neopentyl glycol diglycidyl ether, neopentyl glycol monoglycidyl ether, glycerol
diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane diglycidyl ether,
trimethylolpropane monoglycidyl ether, trimethylolpropane triglycidyl ether, diglycerol
triglycidyl ether, sorbitol tetraglycidyl ether, allylglycidyl ether, and 2-ethylhexylglycidyl ether.
Example of the (meth)acrylate monomer having a functional group reacting
with epoxy group of the epoxy compound is the above mentioned (meth)acrylate monomer
having a carboxyl group (comprising (meth)acrylic acid).
The oligomer (B-a) can be produced by the conventionally known method with performing
the reaction wherein properties of the obtained oligomer (B-a) are included within
ranges hereinabove.
[Oligomer (B-b)]
As for the oligomer (B-b), the compound produced by reacting the polyether polyol
having one or more, preferably 2 or more hydroxyl groups in a molecule and the
(meth)acrylate monomer having a functional groups reacting with the hydroxyl groups
(comprising (meth)acrylic acid) can be used. A blending ratio for reacting both
components (hydroxyl group of the polyether polyol/functional groups of the (meth)acrylate
monomer) is preferably within a range of 0.8 to 1.2, more preferably 0.9 to 1.1.
Examples of the polyether polyol are a compound obtained by the conventional
addition polymerization of one or more compounds having at least 2 active hydrogen
atoms, for example ethylene glycol, diethylene glycol, triethylene glycol, propylene
glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl
glycol, glyderin, trimethylolethane, trimethylolpropane and sorbitol using an initiator,
for example one or more cyclic ether monomers such as ethylene oxide, propylene
oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran or cyclohexylene oxide.
As for the polyether polyol, alkylene oxide addition polymer, i.e. oligomer compound
having 2 or more hydroxyl groups and consisting of repeating [—R—O—]
units (wherein R is alkylene group or its derivatives), can preferably be used.
R which can be used contains 2 to 6 carbons and are ethylene, propylene and butylene
groups may be used. In a molecule, different types of [—R—O—]
units may be included. Concrete examples thereof are polyethylene glycol, polypropylene
glycol, etc.
Examples of the (meth)acrylate monomer having a functional group reacting
with hydroxyl group of polyether polyol are the above mentioned (meth)acrylate
monomer having a carboxyl group (comprising (meth)acrylic acid).
The oligomer (B-b) can be produced by a conventionally known method with performing
the reaction where properties of the obtained oligomer (B-b) are within ranges hereinabove.
[Oligomer (B-c)]
As for oligomer (B-c), the compound obtained by reacting the intermediate having
a hydroxyl group or an isocyanate group prepared by reacting polyether polyol or
polyester polyol with polyisocyanate compound with the (meth)acrylate monomer having
a functional group reacting with these groups (comprising (meth)acrylic acid) can
be used. The compound obtained by reacting with (meth)acrylate monomer having a
functional group reacting with a hydroxyl group (comprising (meth)acrylic acid),
when the intermediate has a hydroxyl group, or the compound obtained by reacting
with (meth)acrylate monomer having a functional group reacting with isocyanate
group, when the intermediate has an isocyanate group, can be used.
Example of the polyether polyol is the above mentioned polyether polyol.
Example of the polyester polyol is the above mentioned polyester polyol.
A blending ratio of each component for production of the intermediate having a
hydroxyl group (hydroxyl group of the polyether polyol or the polyester polyol/isocyanate
group of polyisocyanate compound) is preferably 1.1 or more, more preferably 1.2
or more.
A blending ratio of each component for production of the intermediate having
isocyanate
group (hydroxyl group of the polyether polyol or the polyester polyol/isocyanate
group of polyisocyanate compound) is preferably 0.9 or less, more preferably 0.8
or less.
Examples of the polyisocyanate compound are aliphatic diisocyanate such
as tetramethylenediisocyanate, hexamethylenediisocyanate, trimethylhexamethylenediisocyanate
and isophoronediisocyanate; alicyclic diisocyanate such as 4,4′-methylene
bis(cyclohexylisocyanate) and isophoronediisocyanate; aromatic diisocyanate such
as xylylenediisocyanate, tolylenediisocyanate, diphenylmethanediisocyanate and
polyphenylmethanediisocyanate (hereinafter designates as MDI), and hydrogenated
compound thereof; and analogous compounds such as isocyanurate and biuret thereof.
Example of the (meth)acrylate monomer having a functional group reacting
with a hydroxyl group is the above mentioned (meth)acrylate having a carboxyl group
(comprising (meth)acrylic acid).
Example of the (meth)acrylate monomer having a functional group reacting
with an isocyanate group is the above mentioned (meth)acrylate having a hydroxyl group.
The oligomer (B-c) can be produced by the conventionally known method with performing
the reaction where properties of the obtained oligomer (B-c) are within ranges hereinabove.
[Photopolymerization Initiator (C)]
The conventionally known photopolymerization initiator can be properly selected
and used as the photopolymerization initiator (C). Concrete examples can be mentioned
as follows.
(1) Acetophenone based compounds: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one,
1-hydroxy-cyclohexyl-phneyl-ketone, 4-phenoxydichloroacetophenone, 4-ter-butyl-dichloroacetophenone,
4-ter-butyl-trichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one,
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one
and 4-(2-hydroxyphenoxy)-phenyl(2-hydroxy-2-propyl)ketone.
(2) Thioxanthone based compounds: Thioxanthone, 2-chlorthioxanthone, 2-methylthioxanthone,
2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone and 2,4-dichlorthioxanthone.
(3) Phosphine oxide based compounds: 2,4,6-trimethylbenzoyl diphenyl phosphine
oxide and acylphosphine oxide.
(4) Benzoin based compounds: Benzoin and benzoin methyl ether.
Others: Dimethylbenzyl ketal, and oligo-2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane.
Among these compounds, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one,
1-hydroxycyclohexylphenyl-ketone and 2,4-diethylthioxanthone are preferable due
to the superior curing property.
Examples of commercially available products of the photopolymerization initiators
are Lucirin TPO (BASF Inc., Trade name), Irgacure 1700, Irgacure 149, Irgacure
1800, Irgacure 1850, Irgacure 819, Irgacure 184, Irgacure 907 (Chiba Specialty
Chemicals, Inc., Trade name), and Kayacure DETX-S (Nippon Kayaku Co., Ltd., Trade name).
In the present invention, silicone additives (D) other than the above components
(A)-(C) can be blended. As a result of blending the component (D), smoothness and
slippage can be provided on the coating surface of the covering layer and a bundle
of the optical fiber can be easily drown out from the matrix covering layer of
the optical fiber.
Examples of silicone additive (D) are nonfunctional organic polysiloxanes
without having a functional group such as polydimethylsiloxane and polyether modified
polysiloxane and functional organic siloxanes having at least a functional group
selected from vinyl group, amino group, mercapto group, etc.
Examples of the above polyether modified dimethylpolysiloxane are: (1) alternating
copolymer or random copolymer of dimethylsiloxane and cyclic ether such as ethylene
oxide, propylene oxide, butylene oxide and tetrahydrofuran; (2) block copolymer
of dimethylpolysiloxane and the above polyether polyol; and (3) pendant polyether
modified dimethylpolysiloxane, in which polyether polyol group is introduced into
dimethylpolysiloxane as the side chain.
The commercially available silicone additives are, for example, "BYK-UV3510",
a trade name of the product of BYK Chemie Japan, Inc.; "DC-57" and "DC-190", trade
names of products of Dow Corning Inc.; "L-7001", "L-7002", "L-7500", "L-720", "L-77",
"L-722" and "L-7602", trade names of products of Nippon Unicar Co., Ltd.; "SH-28PA",
"ST-86PA", "SF-8416" and "SF-8419", trade names of products of Dow Corning Toray
Silicone Co., Ltd.; and "KP-322", "KP-323" and "KP-341", trade names of products
of Shin-Etsu Chemical Co., Ltd.
Example of polysiloxane having a vinyl group is a reaction product of silane
compound having a vinyl group and hydrolytic silane compound.
Examples of silane having a vinyl group are vinyltriethoxysilane, vinyltrimethoxysilane,
vinyltris(methoxyethoxy)silane, γ-methacryloyloxypropyl trimethoxysilane
and 2-styrylethyltrimethoxysilane.
Examples of hydrolytic silane compound are monoalkoxysilane such as methoxytrimethylsilane,
methoxytriethylsilane, methoxymethyldiethylsilane, ethoxytrimethylsilane, ethoxytriethylsilane,
ethoxytriphenylsilane, propoxytrimethylsilane, propoxytripropylsilane, butoxytributylsilane
and phenoxytriphenylsilane; and dialkoxysilane such as dimethoxydimethylsilane,
dimethoxydiethylsilane, dimethoxydiphenylsilane, diethoxydimethylsilane, diethoxydiethylsilane,
diethoxydiphenylsilane, dipropoxydimethylsilane, dipropoxydiethylsilane, dipropoxydipropylsilane,
dipropoxydiphenylsilane, dibutoxydimethylsilane, dibutoxydiethylsilane, dibutoxydibutylsilane,
and dibutoxydiphenylsilane.
Examples of commercially available polysiloxane having a vinyl group are
"X-22-164B", "X-22-164C" and "X-22-2404", trade name of products of Shin-Etsu Chemical
Co., Ltd. and "SZ6075" and "SZ6300", trade name of products of Toray Dow Corning
Silicone Co. Ltd.
In addition to the above, modified silicone having a vinyl group, for example,
polyester modified dimethylpolysiloxane having a vinyl group (BYK-371, trade name
of the product of BYK Chemie Japan Inc.) and polyether modified dimethylsiloxane
having acryloyl group (BYK-UV3500 and BYK-UV3530, trade name of products of BYK
Chemie Japan, Inc.) can also be used.
Example of polysiloxane having an amino group is the reaction product of
silane compound having an amino group and the above mentioned hydrolytic silane compound.
Examples of silane compound having an amino group are γ-N-(2-aminoethyl)aminopropyltrimethoxysilane,
p-(N,N-dimethylamino)phenyltriethoxysilane, N-(2-aminoethyl)aminomethylphenetyl
trimethoxysilane, 3-aminopropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane,
γ-N,N-bis(2-hydroxyethyl)aminopropyltriethoxysilane, bis[3-(triethxysilyl)propyl]amine,
γ-N,N-diethylaminopropyltrimethoxysilane, and N,N-dimethylaminophenyltriethoxysilane.
Examples of commercially available products are "X-22-161A", "KF-860" and
"KF-858", trade name of products of Shin-Etsu Chemical Co., Ltd. and "BY-16-209"
and "BY16-853C", trade name of products of Dow Corning Toray Silicone Co. Ltd.
Example of polysiloxane having a mercapto group is the reaction product of
silane compound having a mercapto group and the above hydrolytic silane compound.
Examples of silane compound having a mercapto group are γ-mercaptopropyl
trimethoxysilane and γ-mercaptopropylmethyl dimethoxysilane.
Examples of commercially available products are "X-22-167B", "KF-2001",
"KBM803" and "KP-358", trade name of products of Shin-Etsu Chemical Co., Ltd. and
"SH6062", trade name of products of Dow Corning Toray Silicone Co. Ltd. In addition,
products described in Japanese Patent Laid-Open No. 59-88344 can be used.
In the present invention, in addition to the above components, the photopolymerizable
unsaturated compound (E) can also be blended.
A monofunctional monomer or polyfunctional monomer can be used as the photopolymerizable
unsaturated compound (E).
Examples of the monofunctional monomer of the component (E) are, for example,
as follows.
(1) C
1-24 alkyl or cycloalkyl ester of (meth)acrylic acid; for example,
methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate,
2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate and
decyl acrylate.
(2) Basic vinyl monomer; for example, N-vinyl-2-pyrrolidone, acryloylmorpholine,
(meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, diacetoneacrylamide,
N-methylol(meth)acrylamide, and N-butoxymethylacrylamide.
(3) Vinyl monomer having glycidyl group; for example, glycidyl(meth)acrylate,
glycidyl(meth)acrylamide, and allylglycidyl ether.
(4) Aromatic vinyl monomer; for example, styrene and vinyltoluene.
(5) Alicyclic vinyl monomer; for example, isobornyl acrylate.
(6) Other monofunctional monomer; for example, vinyl propionate, α-methylstyrene,
vinyl acetate, (meth)acrylonitrile, vinyl pivalate and Veova monomer (trade names
of products of Shell Chemicals, Inc.).
Examples of the polyfunctional monomer of the component (E) are trimethylolpropane
tri(meth)acrylate, trimethylolpropane di(meth)acrylate, glycerol di(meth)acrylate,
glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol
tetraacrylate, dipentaerythritol hexaacrylate, trimethylolpropane ethoxytri(meth)acrylate,
bisphenol A diglycidylacrylate and tricyclodecane diacrylate.
In the present invention, oligomer component other than the oligomer component
(A) and the oligomer component (B) can be used, if necessary, as the component
(E). A blending ratio of the oligomer components is preferably 40% by weight or
less, more preferably 20% by weight or less in total of the polymerization components
of components (A), (B) and (E).
In the present invention, the blending ratio of the oligomer (A), the oligomer
(B) and the unsaturated compound (E) is preferably set based on the total weight
of the polymerization components as follows. The blending ratio of the oligomer
(A) is preferably 5% by weight or more, more preferably 10% by weight or more,
most preferably 15% by weight or more, and on the contrary, preferably 40% by weight
or less, more preferably 30% by weight or less. The blending ratio of the oligomer
(B) is preferably 20% by weight or more, more preferably 30% by weight or more,
most preferably 40% by weight or more, and on the contrary, preferably 70% by weight
or less, more preferably 60% by weight or less. Since the unsaturated compound
(E) is an optionally blending component, if this is blended, the blending ratio
is, from the standpoint of obtaining sufficient properties of the oligomers (A)
and (B), preferably 50% by weight or less, more preferably 40% or less, and is,
from the standpoint of obtaining desired properties, preferably 10% or more. When
an amount of the oligomer (A) is excessively small, the crosslinking density is
decreased, as a result, the deformation of the covering film to temperature change
is increased, and contrary to that, when the amount of the oligomer (A) is excessively
large, the crosslinking density becomes too high and rigid, and as a result, flexibility
of the covering film is decreased. Since when an amount of the oligomer (B) is
too small, the crosslinking density becomes too high to result in rigidity and
insufficient flexibility of the covering film, the flexibility of the covered optical
fiber is decreased, and contrary to that, when the amount of the oligomer (B) is
excessively large, the crosslinking density is decreased, and as a result, the
deformation of the covering film to temperature change is increased.
The blending ratio of the photopolymerization initiator (C) is, from the standpoint
of sufficiently increasing the photoreactivity to cure the coating film sufficiently,
preferably 0.1 part by weight or more, more preferably 1 part by weight or more,
most preferably 3 parts by weight or more to the total sum of 100 parts by weight
of the oligomer (A), the oligomer (B) and the unsaturated compound (E). On the
contrary, from the standpoint of suppressing excessive light absorption of the
photopolymerization initiator and obtaining sufficient curing of the deep region
of the coating film, the blending ratio is preferably 20 parts by weight or less,
more preferably 12 parts by weight or less, most preferably 10 parts by weight
or less to the total sum of 100 parts by weight of the above.
In the present invention, when the silicone additive (D) is blended, the blending
ratio is, from the standpoint of obtaining sufficient effect of the addition, preferably
0.1 part by weight or more, more preferably 1 part by weight or more, most preferably
3 parts by weight or more to the total sum of 100 parts by weight of the oligomer
(A), the oligomer (B) and the unsaturated compound (E). On the contrary, from the
standpoint of not to lower the objective effect of the present invention, the blending
ratio is preferably 15 parts by weight or less, more preferably 10 parts by weight
or less to the total sum of 100 parts by weight of the above.
In the present invention, in addition to the above components (A)-(E), if necessary,
conventionally known additives such as pigment, organic solvent, filler, fluidity
adjuster and photopolymerization reaction promoter may be blended.
Next, the covered optical fiber of the present invention is explained.
In the conventionally known covered optical fiber which is sequentially laminated
with the primer covering layer, the ink covering layer and the matrix covering
layer in the periphery of the core (the optical fiber), the covered optical fiber
of the present invention is that any one of layers of the primer covering layer,
the ink covering layer and the matrix covering layer is constituted by the above
covering compositions for optical fiber.
As for the core, the conventionally known glass fiber for optical transmission
prepared by spinning optical glass materials such as silica can be used. Generally,
the glass fiber preferably has a diameter of 200 μm or less in order to maintain
the flexibility. For example, the glass fiber having the diameter of 10 μm-200
μm can be used.
The primer-covering layer which covers the core with the secondary layer on the
surface of the primary layer can be used. Thickness of the primer-covering layer
is preferably within a range of 40 to 120 μm, more preferably 60 to 100 μm.
Thickness of the primary layer is preferably within a range of 20 to 60 μm,
more preferably 30 to 50 μm. Thickness of the secondary layer is preferably
within a range of 20 to 60 μm, more preferably 30 to 50 μm.
The primary layer, which is superior in adhesiveness to the core as well as superior
in adhesiveness to the secondary layer, is used. In the primary layer, processability
and optical flexibility are important, and generally soft covering materials are
used. For that purpose, when the covering composition for the optical fiber of
the present invention is used in the primer-covering layer, it is preferably used
in the secondary layer rather than the primary layer.
Since the secondary layer is positioned between the primary layer and the ink
covering layer, the covering material which is superior in the adhesiveness to
both of the primary layer and the ink covering layer as well as relatively hard
is generally used for the secondary layer. The covering composition for optical
fiber of the present invention is preferable for the material constructing the
secondary layer.
The composition comprising the following components is preferably used for the
covering composition for optical fiber of the present invention, and the composition
hereinbelow described is specifically preferable as a material for constructing
the secondary layer.
The component (A) preferably used is the polyester oligomer of 3 or more functionalities
represented by the general formula hereinbefore, and does not contain the soft
natured components such as alkylene oxide unit and caprolactone unit as the constitutional
component of the polyester.
As for the component (B), at least one component selected from the following
components
(B-a), (B-b) and (B-c) is preferable.
Preferable component (B-a) is bisphenol A glycidyl modified (meth)acrylate.
Preferable component (B-b) is polypropylene glycol di(meth)acrylate. Preferable
component (B-c) is urethane polyether polyol modified (meth)acrylate or urethane
polyester polyol modified (meth)acrylate obtained by reacting aliphatic diisocyanate
with polyether polyol such as alkylene polyol or polyester polyol.
As for the component (C), at least one initiator selected from thioxanthone based
compound, acetophenone based compound and phosphine oxide based compound is preferable.
As for the component (D), polyether modified polydimethylsiloxane having acryloyl
group and silicone having a mercapto group are preferable.
As for the component (E), isobornyl acrylate, N-vinyl-2-pyrrolidone and acryloylmorpholine
are preferable.
The ink covering layer is the layer positioned between the primer covering layer
(secondary layer) and the matrix covering layer, and requires the following properties.
(1) Superior in the adhesiveness with the primer covering layer (the secondary layer).
(2) Having proper adhesiveness with the matrix covering layer in the degree of
enabling separation of the optical fiber from the matrix covering layer.
(3) Superior in waterproof.
(4) Shorter curing time even in blending with pigment.
The composition blending the conventionally known pigment with the material constructing
the above secondary layer can be used, for example, as the composition constituting
the ink covering layer.
The matrix covering layer is, for example in order to use the optical fiber therewith
for multichannel transmission, used for the purpose of bundling the assembly of
plurality of covered optical fibers (wherein the primer covering layer and the
ink covering layer are sequentially laminated on the periphery of the optical fiber)
with the matrix material.
The assembly of the optical fibers bundled with the matrix material is generally
called as a ribbon assembly. The ribbon assembly is required to connect each of
the ribbon assembly in series, or to install the junction for branching fibers
in the intermediate point to each terminal of the ribbon assembly. For that purpose,
operation (separation) to peel off the matrix covering layer from the ink covering
layer is performed. In this operation, in order not to peel off the ink covering
layer from the fiber, the ink covering layer should be formed with sufficient adhesion
force, and the matrix covering layer should be formed on the ink covering layer
with proper adhesion force. Further, it is preferable that the ink covering layer
is attached so that it can not be peeled off from the fiber even if the ribbon
assembly is bent during the wiring operation in a working site.
The matrix covering layer requires toughness such as resistance to a scratch
so as not easily to be damaged, when the physical force is added to the layer at
the working site. The matrix covering layer with small mechanical changes and small
optical transmission loss is requested under the condition using the optical fiber
in the environmental temperature changes. The matrix covering layer with desired
properties can be formed by using the covering composition for the optical fiber
of the present invention.
The matrix covering layer is properly determined generally within a range of
5 to 350 μm thick, preferably 30 to 50 μm thick.
With regard to the composition for constructing the matrix covering layer, for
example, the composition with the material constituting the above secondary layer
or said material without blending the component (D) can be used.
In the present invention, the primer covering layer, the ink covering layer and
the matrix covering layer preferably have the crosslinking density within a range
of 100 to 1000, more preferably 600 to 800.
EXAMPLE
The present invention is explained in detail by illustrating the example. The
present invention is not limited within the example.
Components used in the example and the comparative example are as follows.
(A) Unsaturated polyester oligomer component:
- (1) A reaction product (molecular weight: 800, glass transition temperature:
250° C.) of polyester polyol (trimethylolpropane/ethylene glycol/terephthalic
acid esterification product) and acrylic acid.
- (2) A reaction product (molecular weight: 1200, glass transition temperature:
300° C.) of polyester having hydroxyl group and carboxyl group (trimethylolpropane/ethylene
glycol/terephthalic acid/trimellitic acid esterification product) and acrylic acid
and 2-hydroxyethylacrylate.
(B) Modified (meth)acrylate oligomer component:
- (B-a) Epoxy modified (meth)acrylate oligomer component:
A reaction product of bisphenol A diglycidyl ether and acrylic acid (molecular
weight: 480, numbers of acryloyl group in a molecule: average 2)
- (B-b) polyether polyol modified (meth)acrylate oligomer component:
- (1) Polypropylene glycol diacrylate (molecular weight: 580),
- (2) Polyethylene glycol diacrylate (molecular weight: 300)
- (B-c) Urethane polyether polyol modified or urethane polyester polyol
modified (meth)acrylate components:
- (1) A reaction product of hydroxyacrylate and hydrogenated xylylenediisocyanate
and polyethylene glycol (molecular weight: 1030, numbers of acryloyl group in a
molecule: average 2)
- (2) A reaction product of hydroxyacrylate and tolylenediisocyanate
and polyester polyol (ethylene glycol/adipic acid/terephthalic acid esterification
product) (molecular weight: 1700, numbers of acryloyl group in a molecule: average 2)
(C) Photopolymerization initiator component:
- (1) 1-hydroxycyclohexylphenylketone
- (2) 2,4,6-trimethylbenzoyldiphenylphosphine oxide
- (3) 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one
(D) Silicone additive component:
- (1) Polyether modified polydimethylsiloxane having acryloyl group
- (2) 3-mercaptopropyl polydimethylsiloxane
(E) Other photopolymerizable Monomer or oligomer component:
- (1) Bisphenol A diglycidyl acrylate
- (2) Isobornyl acrylate
- (3) Tricyclodecane diacrylate
- (4) N-vinyl-2-pyrrolidone
- (5) Acryloyl morpholine
- (6) Dipentaerythritol hexaacrylate
- (7) Pentaerythritol tetraacrylate
The covering compositions for optical fiber described in examples 1 to 5 and
comparative examples 1 to 4 were prepared with the blending ratio described in
Table 1. Numerals in Table 1 indicate parts by weight.
| |
TABLE 1 |
| |
|
| |
|
Comparative |
| |
Example |
example |
| Oligomer (A) |
(1) |
|
|
|
20 |
|
|
|
|
|
|
| |
(2) |
|
10 |
10 |
|
10 |
10 |
| Oligomer (B) |
(B-a) |
|
|
|
|
5 |
|
|
|
5 |
5 |
| |
(B-b) |
(1) |
|
|
|
|
|
|
|
|
5 |
| |
|
(2) |
|
|
|
|
5 |
|
|
|
5 |
| |
(B-c) |
(1) |
55 |
|
55 |
50 |
50 |
|
55 |
45 |
50 |
| |
|
(2) |
|
50 |
|
|
|
55 |
|
20 |
| Photopolymerization |
(1) |
|
3 |
3 |
2 |
3 |
3 |
|
|
3 |
| initiator (C) |
(2) |
|
|
|
|
|
|
3 |
3 |
| |
(3) |
|
|
|
1 |
|
|
1 |
1 |
|
3 |
| Silicone |
(1) |
|
3 |
3 |
3 |
3 |
3 |
3 |
3 |
| additive (D) |
(2) |
|
0.5 |
0.5 |
0.5 |
0.5 |
0.5 |
0.5 |
0.5 |
| Monomer (E) |
(1) |
|
|
5 |
5 |
|
|
|
|
10 |
10 |
| |
(2) |
|
|
|
10 |
|
|
15 |
10 |
| |
(3) |
|
15 |
15 |
10 |
15 |
15 |
10 |
15 |
15 |
10 |
| |
(4) |
|
|
|
|
|
|
5 |
5 |
5 |
5 |
| |
(5) |
|
20 |
20 |
10 |
20 |
20 |
| |
(6) |
|
|
|
|
|
|
15 |
| |
(7) |
|
|
|
|
|
|
|
15 |
|
Preparation of cured products and evaluation thereof
Physical properties of the coated films hereinbelow were determined using
the compositions obtained in examples 1 to 5 and comparative examples 1 to 4. Results
are shown in Table 2.
| |
TABLE 2 |
| |
|
| |
Example |
Comparative example |
| Young's |
-40° C. |
2100 |
2100 |
2200 |
2100 |
2100 |
2300 |
3000 |
1600 |
800 |
| modulus (Mpa) |
23° C. |
1010 |
920 |
1100 |
1000 |
1000 |
1070 |
1420 |
550 |
260 |
| |
60° C. |
340 |
320 |
360 |
330 |
330 |
390 |
550 |
230 |
80 |
| Temperature |
-40° C./23° C. |
2.1 |
2.3 |
2.0 |
2.1 |
2.1 |
2.1 |
2.1 |
2.9 |
3.1 |
| dependency of |
23° C./60° C. |
3.0 |
2.9 |
3.1 |
3.0 |
3.0 |
2.7 |
2.6 |
2.4 |
3.3 |
| Young's |
-40° C./60° C. |
6.2 |
6.6 |
6.1 |
6.3 |
6.3 |
5.9 |
5.5 |
7.0 |
10.0 |
| modulus |
| Rate of |
53 |
35 |
28 |
52 |
51 |
17 |
13 |
53 |
49 |
| elongation-after-fracture (%) |
| Molecular weight between |
710 |
740 |
780 |
720 |
720 |
510 |
260 |
700 |
840 |
| cross-linkages |
|
Preparation of the coated films (cured products) and evaluation thereof
are as follows.
(1) Young's Modulus and a Rate of Elongation-After-Fracture
The composition hereinbefore was coated to the film thickness of 100 μm
on the glass plate. The cured film was obtained by irradiating the composition
with ultraviolet ray having quantity of light 5000 J/m
2, (light source:
metal halide lamp), under nitrogen atmosphere. The cured film was peeled off from
the glass plate to obtain the test sample. The test sample was punched by using
the dumbbell No. 2 and was measured with the following conditions by using the
tensile test machine.
A distance between fixed points of the test piece: 25 mm
Tensile rate: 1 mm/min. for measuring Young's modulus, and 50 mm/min. for
measuring rate of elongation-after-fracture.
Young's modulus was determined by converting the stress to that of 100% extension
when the test piece was extended to increase 2.5% of the distance between the fixed points.
(2) Glass Transition Temperature and Crosslinking Density
The test piece which was the same curing film used in the determination of Young's
modulus was measured by using Dynamic viscoelastometer model Vibron DDV-EA (TOYO
BACDWIN Co. Ltd.). From the obtained dynamic viscoelasticity spectrum, the glass
transition temperature was set to the peak temperature of the loss tangent tan
δ, and the molecular weight between cross-linkages was calculated by using
high temperature elastic modulus and the attained temperature thereof.
As obvious from results of Table 2, examples 1 to 5 exhibit sufficient Young's
modulus in the practical use range at -40° C. to 60° C. and small temperature
dependency as well as the superior rate of elongation-after-fracture.
*
