JP3019399B2 - UV curable resin composition for optical fiber coating - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ultraviolet-curable resin composition for coating an optical fiber.

2. Description of the Related Art It is well known that optical fibers are very brittle and easily damaged, and that optical transmission loss increases due to contamination. For this reason, conventionally, immediately after spinning of an optical fiber, a glass surface is subjected to a primary coating with a material having a low elastic modulus, and then a secondary coating is performed with a material having a high elastic modulus. As these materials, UV-curable resins are used in terms of productivity. Ultraviolet-curable resins are also used when bundling two to ten optical fibers with primary and secondary coatings into a tape.

[Problems to be Solved by the Invention] In recent years, in order to improve the productivity of optical fiber strands,
The spinning speed of the preform is being increased. Accordingly, the amount of ultraviolet light applied to the ultraviolet curable resin that coats and cures the glass fiber immediately after melt spinning of the preform is also reduced, and there is a need for an ultraviolet curable resin that sufficiently cures even with a low amount of ultraviolet light.

On the other hand, an optical fiber cable containing a plurality of coated optical fibers is used in various environments, but the cable is often immersed in water in a pipeline or a manhole. In order to prevent the strength of the optical fiber from deteriorating in such an environment, gas maintenance by flowing dry air into the cable and a waterproof cable filled with a waterproof material in the cable have been put into practical use. Not many waterproof cables are being used.

However, it is difficult to completely block water with a waterproof material alone, and for a long time (for example, cable life
(10 years), it is difficult to ensure that the protective coating of the optical fiber or water does not penetrate the optical fiber surface.

Therefore, there is a problem that the coating material is deteriorated by water and the strength of the optical fiber itself is reduced.

In addition, there is also a problem that water accumulated in some places in a pipe or a manhole becomes alkaline, and the coating layer of the optical fiber is alkali-hydrolyzed.

To solve these problems, Japanese Patent Laid-Open No. 1-87535
Japanese Patent Application Laid-Open (JP-A) No. 2000-1972 discloses that an ultraviolet curable resin composition for coating an optical fiber having a low water absorption hardly hydrolyzes for a long period of time even in the presence of an alkali. There is a description that an optical fiber coated with the ultraviolet curable resin composition hardly deteriorates in a coating layer in an alkali atmosphere, and therefore the fiber strength can be maintained for a long period of time.

Therefore, from the viewpoint of long-term reliability, an ultraviolet curable resin having a low water absorption is required.

The problem to be solved by the present invention is to provide an ultraviolet-curable resin composition for optical fiber coating, which can be sufficiently cured even with a low amount of ultraviolet light, has a low water absorption rate, and can form a coating layer with less deterioration of the coating material due to water. Is to do.

[Means for Solving the Problems] The present invention provides the following inventions to solve the above problems.

1. An ultraviolet-curable resin composition for coating an optical fiber, comprising: (1) a polymerizable unsaturated polyurethane, (2) a polymerizable unsaturated compound having an ethylenically unsaturated bond, and (3) a photopolymerization initiator. (1) The polymerizable unsaturated polyurethane has a general formula (In the formula (I), R is H or CH _3. ) As a polymerizable unsaturated compound having a polymerizable unsaturated group represented by the following formula (2) and an ethylenically unsaturated bond, An ultraviolet-curable resin composition for coating an optical fiber, wherein decane dimethanol diacrylate is used.

2. A polymerizable unsaturated polyurethane obtained by reacting (1) (a) a polyisocyanate and (b) a compound having an active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group, 2) a polymerization selected from the group consisting of (a) a polyisocyanate, (b) a compound having an active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group, and (c) a polymerizable unsaturated polyurethane obtained by reacting a polyol. 2. The ultraviolet curing for coating an optical fiber according to the above 1, wherein the polymerizable unsaturated polyurethane is a polymerizable unsaturated polyurethane in which the compound having active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group is 2-hydroxypropyl acrylate. Mold resin composition.

3. The above 2 wherein the polyol is a polyether polyol
The ultraviolet-curable resin composition for coating an optical fiber according to the above.

4. A polymerizable unsaturated polyurethane obtained by reacting (a) a polyisocyanate, (b) a compound having an active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group, and (c) a polyol. The polymerizable unsaturated polyurethane selected from the group consisting of the above, wherein the compound having active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group is a polymerizable unsaturated polyurethane that is 2-hydroxypropyl acrylate. UV curable resin composition for coating optical fibers.

5. The ultraviolet-curable resin composition for coating an optical fiber according to the above item 4, wherein the polyol is polytetramethylene glycol.

 Hereinafter, the present invention will be described in detail.

The polymerizable unsaturated polyurethane used in the present invention is a polyisocyanate and hydroxypropyl acrylate,
It can be obtained by reacting with a polyol if necessary.

Generally, as a compound having an active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group, for example, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, phenoxyhydroxypropyl acrylate, butoxyhydroxypropyl acrylate, Pentaerythritol acrylate, dipentaerythritol monohydroxypentaacrylate, trimethylolpropane diacrylate, dipropylene glycol monoacrylate, 1, 6
-Hexanediol monoacrylate, glycerin diacrylate, caprolactone-modified 2-hydroxyethyl acrylate, stearic acid-modified pentaerythritol diacrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polytetramethylene glycol monoacrylate, copolymer of propylene oxide and ethylene oxide Unified monoacrylate, monoacrylate of a copolymer of tetrahydrofuran and propylene oxide, monoacrylate of a copolymer of tetrahydrofuran and ethylene oxide,
Hydroxy compounds having an acryloyl group such as monoacrylate of an ethylene oxide adduct of bisphenol A and monoacrylate of a propylene oxide adduct of bisphenol A can be given.

However, as a component of the polymerizable unsaturated polyurethane, there is no example in which the compound has been studied from the viewpoint of curability and water absorption. For example, as seen in JP-A-2-9732 and JP-A-2-92911, The hydroxy compounds having an acryloyl group are merely described in a row, and generally, hydroxyethyl acrylate has been regarded as suitable.

However, as shown in Table 1, the present inventors have found that the curability and water absorbency differ greatly depending on the selection of the compound, and have led to the present invention.

Examples of the polyol used in the present invention include polyol compounds such as polyether, polyester, polycarbonate, polybutadiene, hydrogenated polybutadiene, and polysiloxane. In view of the above, polyether polyol is particularly preferred.

Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, a copolymer of propylene oxide and ethylene oxide, a copolymer of tetrahydrofuran and propylene oxide, a copolymer of tetrahydrofuran and ethylene oxide, and bisphenol A. And an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A. These commercially available products include (1) “PEG 600”, “PEG 1000” and “PEG 2000” as polyethylene glycol.
(Manufactured by Sanyo Chemical), (2) As polypropylene glycol, "PPG diol 1000", "PPG diol 2000" and "PPG diol 3000" (manufactured by Mitsui Toatsu Chemicals), "Exenol 1020", "Exenol 2020" and "Exenol"
3020 ”(manufactured by Asahi Glass) and (3)“ PTG 650 ”,“ PTG 850 ”,“ PTG 100
0 ”,“ PTG 2000 ”and“ PTG 4000 ”(manufactured by Hodogaya Chemical), (4) As copolymers of propylene oxide and ethylene oxide,“ ED-28 ”(manufactured by Mitsui Toatsu) and“ Exenol 510 ”(manufactured by Mitsui Toatsu) Asahi Glass), (5) As a copolymer of tetrahydrofuran and propylene oxide,
"PPTG 1000", "PPTG 2000" and "PPTG 4000"
(Manufactured by Hodogaya Chemical), "Unisafe DCB-1100" and "Unisafe DCB-1800 (manufactured by NOF Corporation), (6) As copolymers of tetrahydrofuran and ethylene oxide," Unisafe DC-1100 "and" Unisafe DC-
1800 "(manufactured by NOF CORPORATION), (7) As an ethylene oxide adduct of bisphenol A," Uniol DA-40
0 "and" Uniall DA-700 "(manufactured by NOF Corporation),
(8) Examples of the propylene oxide adduct of bisphenol A include "Uniol DB-400" (manufactured by NOF Corporation).

These compounds may be used alone or in combination of two or more.

Examples of the polyisocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, tetramethyl xylylene diisocyanate, trimethyl hexamethylene diisocyanate,
Examples thereof include 5-naphthalene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate, and lysine diisocyanate.

These polyisocyanate compounds may be used alone or in combination of two or more.

As the polymerizable unsaturated compound having an ethylenically unsaturated bond used in the present invention, it is essential that tricyclodecane dimethanol diacrylate is used. A series compound is used. When a cured film requires softness, a monofunctional (meth) acrylate compound is used. When a cured film requires hardness, a bifunctional or higher polyfunctional acrylate compound is used. Is generally used.

Specific examples of the polymerizable unsaturated compound having an ethylenically unsaturated bond used in the present invention include: an aromatic vinyl monomer such as styrene, chlorostyrene, and divinylbenzene; as a substituent, methyl, ethyl, propyl, butyl, Amyl, 2-ethylhexyl, octyl, nonyl,
Dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl, phenoxyethyl, nonylphenoxyethyl, tetrahydrofurfuryl, allyl, methallyl, glycidyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro-2-hydroxy Acrylate, methacrylate or fumarate having a group such as propyl, dimethylaminoethyl, diethylaminoethyl, nonylphenoxyethyltetrahydrofurfuryl; ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, tetramethylene glycol; Mono (such as hexamethylene glycol, trimethylolpropane, glycerin and pentaerythritol) Data) acrylate or poly (meth)
Acrylates: vinyl acetate, vinyl butyrate or vinyl benzoate, acrylonitrile, cetyl vinyl ether, limonene, cyclohexene, diallyl phthalate, 2-, 3-
-Or 4-vinylpyridine, acrylic acid, methacrylic acid, acrylamide, methacrylamide, N-hydroxymethylacrylamide or N-hydroxyethylacrylamide and their alkyl ether compounds, 2 mol or more of ethylene oxide or propylene per mol of neopentyl glycol Di (meth) acrylate of diol obtained by adding oxide, di or tri (meth) acrylate of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane, and 1 mol of bisphenol A 1 mol of di (meth) acrylate or 2-hydroxyethyl (meth) acrylate of a diol obtained by adding 2 mol or more of ethylene oxide or propylene oxide to phenylisocylate Reaction products of sulfonate or n- butyl isocyanate 1 mol, may be mentioned poly (meth) acrylate of dipentaerythritol.

A group consisting of N-vinyl-2-pyrrolidone, acryloylmorpholine, vinylimidazole, vinylcaprolactam, vinyl-p-tert-butylbenzoate, cyclohexyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, and dicyclopentenyl acrylate At least one monomer selected from the group consisting of (meth) acrylates having a bifunctional or higher functionality can be used, and the curability can be improved, a high gel fraction can be obtained after curing, and a highly reliable material can be provided. .

The photopolymerization initiator used in the present invention may be any as long as it generates a radical by light, and the radical efficiently reacts with the polymerizable unsaturated compound. There are a type in which a molecule is cleaved to generate a radical and a type in which a complex is used such as a combination of an aromatic ketone and a hydrogen donor.

Examples belonging to the former include, for example, benzoylethyl ether, benzoin isobutyl ether, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2, 4, 6-trimethylbenzoyldiphenylphosphine oxide, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone -1 and the like.

The aromatic ketones of the latter examples include, for example, benzophenone, 4-phenylbenzophenone, isophthalophenone, 4-benzoyl-4′-methyl-diphenylsulfide, 2,4-diethylthioxanthone, 2-isopropylthioxanthone and -Chlorothioxanthone and the like, and as the hydrogen donor combined therewith, for example, a mercapto compound, an amino compound and the like can be mentioned, but an amine compound is generally preferable.

As the amine compound, for example, triethylamine, methyldiethanolamine, triethanolamine, diethylaminoethyl (meth) acrylate, p-
Examples include dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N, N-dimethylbenzylamine, and 4,4'-bis (diethylamino) benzophenone.

These photopolymerization initiators may be used alone or in combination of two or more.

Further, as other additives, a thermal polymerization inhibitor, an antioxidant, a plasticizer, a silane coupling agent, and the like can be added for the purpose of improving various properties.

The ultraviolet resin composition for coating an optical fiber of the present invention,
(1) 10 to 80% by weight of a polymerizable unsaturated polyurethane,
(2) 10 to 80 monomers having an ethylenically unsaturated bond
% By weight and (3) 0.1 to 10% by weight of the photopolymerization initiator.

〔Example〕

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

First, a synthesis example of the polymerizable unsaturated polyurethane of the present invention will be described.

Synthesis Example 1 2 mol of 2,4-tolylene diisocyanate was charged into a reaction vessel equipped with a nitrogen gas inlet tube, a stirrer, and a cooling tube, and 1 mol of polytetramethylene glycol (number average molecular weight 850) was brought to a reaction temperature of 60 ° C. or lower. Add slowly while keeping. After the reaction for 3 hours, 2 mol of 2-hydroxypropyl acrylate, a trace amount of t-butylhydroquinone as a polymerization inhibitor and a trace amount of dibutyltin dilaurate as a catalyst are gradually added, and the mixture is further reacted at 70 ° C. for 7 hours to have an acryloyl group. A polymerizable unsaturated polyurethane (A-1) was obtained.

Example 2 A polymerizable unsaturated polyurethane having an acryloyl group was prepared in the same manner as in Synthesis Example 1 except that 2 mol of 2-hydroxyethyl acrylate was used instead of 2 mol of 2-hydroxypropyl acrylate in Synthesis Example 1. A-
2) was obtained.

Synthesis Example 3 A polymerizable unsaturated polyurethane having an acryloyl group (Synthesis Example 1) was prepared in the same manner as in Synthesis Example 1 except that 2 mol of 2-hydroxybutyl acrylate was used instead of 2 mol of 2-hydroxypropyl acrylate. A-
3) was obtained.

Synthesis Example 4 A polymerizable unsaturated polyurethane having an acryloyl group (Synthesis Example 1) was prepared in the same manner as in Synthesis Example 1 except that 2 mol of 4-hydroxybutyl acrylate was used instead of 2 mol of 2-hydroxypropyl acrylate. A-
4) was obtained.

Hereinafter, Examples and Comparative Examples of the ultraviolet-curable resin composition for coating an optical fiber of the present invention will be described.

Example 1 Polymerizable unsaturated polyurethane (A-1) obtained in Synthesis Example 1
65 parts by weight, 20 parts by weight of tricyclodecane dimethanol diacrylate, 15 parts by weight of N-vinyl-2-pyrrolidone and 5 parts by weight of benzyldimethylketal were mixed and dissolved at 60 ° C. for 1 hour, and the viscosity was 34 poise (25 ° C.). Was obtained.

Comparative Example 1 In Example 1, the polymerizable unsaturated polyurethane (A-
A liquid ultraviolet curable resin composition having a viscosity of 34 poise (25 ° C.) was obtained in the same manner as in Example 1 except that the polymerizable unsaturated polyurethane (A-2) was used instead of 1).

Comparative Example 2 In Example 1, the polymerizable unsaturated polyurethane (A-
A liquid ultraviolet curable resin composition having a viscosity of 38 poise (25 ° C.) was obtained in the same manner as in Example 1 except that the polymerizable unsaturated polyurethane (A-3) was used instead of 1).

Comparative Example 3 In Example 1, the polymerizable unsaturated polyurethane (A-
A liquid ultraviolet curable resin composition having a viscosity of 27 poise (25 ° C.) was obtained in the same manner as in Example 1 except that polymerizable unsaturated polyurethane (A-4) was used instead of 1).

The following evaluation was performed using each of the ultraviolet curable resin compositions obtained in Example 1 and Comparative Examples 1 to 3, and the results are shown in Table 1.

(Evaluation of curability) After applying the UV-curable resin composition on a glass plate so that the dry coating film thickness becomes 200 ± 20 μm, 80 W / cm
Using a metal halide lamp and changing the amount of irradiation under a nitrogen atmosphere. The tensile modulus of the cured film was measured.

The measurement of the tensile modulus was performed in accordance with JIS K7113. In addition, as an index of curability, 20 mJ / cm ² , 1 J / cm ²
The ratio of the tensile modulus at the time of irradiation was taken.

(Measurement of water absorption) The thickness of the dried coating film of the UV-curable resin composition on a glass plate
After applying to 200 ± 20μm, using a metal halide lamp of 80W / cm, irradiate 200m in nitrogen atmosphere.
Cured at J / cm ² . Using this cured film as a sample, JIS K7
The water absorption was measured according to Method B of 209.

[Function] As described in Table 1, the cured film obtained using the ultraviolet-curable resin composition of Example 1 was compared with the cured film obtained using the ultraviolet-curable resin composition of Comparative Example 1. It is evident that both the curability and the water absorption are significantly excellent. Also,
The curability is significantly better than the cured films obtained using the ultraviolet-curable resin compositions of Comparative Examples 2 and 3.

Therefore, it can be understood that the ultraviolet curable resin composition of the present invention can form a coating layer having excellent curability and low water absorption.

[Effect of the Invention] The ultraviolet curable resin composition for coating an optical fiber of the present invention has a higher curing speed and a lower water absorption of the cured coating layer than the conventional ultraviolet curable resin composition.

Therefore, the optical fiber coated with the ultraviolet curable resin composition for coating an optical fiber of the present invention can increase the drawing speed of the optical fiber, so that the productivity can be improved, and High reliability can also be obtained in the use of.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C09D 175/16 G02B 6/44 301A G02B 6/44 301 C03C 25/02 B // (C08F 290/06 220: 28) (56 References JP-A-1-190762 (JP, A) JP-A-2-75614 (JP, A) JP-A-1-153710 (JP, A) JP-A-4-20514 (JP, A) 4-6125 (JP, A) JP-A-4-154828 (JP, A) JP-A-3-166217 (JP, A) JP-A-4-74735 (JP, A) JP-A-3-393314 (JP, A) A) JP-A-2-13338 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 290/00-290/14 C03C 25/02 C09D 1/00-201/10 G02B 6/44

Claims (5)

(57) [Claims] 1. An ultraviolet-curable resin composition for coating an optical fiber, comprising: (1) a polymerizable unsaturated polyurethane, (2) a polymerizable unsaturated compound having an ethylenically unsaturated bond, and (3) a photopolymerization initiator. In the product, (1) the polymerizable unsaturated polyurethane has a general formula (In the formula (I), R is H or CH _3. ) As a polymerizable unsaturated compound having a polymerizable unsaturated group represented by the following formula (2) and an ethylenically unsaturated bond, An ultraviolet-curable resin composition for coating an optical fiber, wherein decane dimethanol diacrylate is used. 2. A polymerizable unsaturated polyurethane comprising (1)
(A) a polyisocyanate and (b) a polymerizable unsaturated polyurethane obtained by reacting a compound having an active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group;
(2) selected from the group consisting of (a) a polyisocyanate, (b) a compound having an active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group, and (c) a polymerizable unsaturated polyurethane obtained by reacting a polyol. The polymerizable unsaturated polyurethane according to claim 1, wherein the compound having active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group is 2-hydroxypropyl acrylate. UV-curable resin composition. 3. The ultraviolet curable resin composition for coating an optical fiber according to claim 2, wherein the polyol is a polyether polyol. 4. A polymerizable unsaturated polyurethane obtained by reacting (a) a polyisocyanate, (b) a compound having an active hydrogen and a polymerizable unsaturated group which reacts with an isocyanate group, and (c) a polyol. A polymerizable unsaturated polyurethane selected from the group consisting of unsaturated polyurethanes, wherein the compound having active hydrogen and a polymerizable unsaturated group that reacts with an isocyanate group is 2-hydroxypropyl acrylate. The ultraviolet curable resin composition for coating an optical fiber according to claim 1. 5. The ultraviolet curable resin composition for coating optical fibers according to claim 4, wherein the polyol is polytetramethylene glycol.