JP3134268B2 - UV curable resin composition for optical fiber coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet curable resin composition for coating an optical fiber.

[0002]

2. Description of the Related Art Optical fibers are very brittle and easily damaged.
It is well known that optical transmission loss increases due to contamination. For this reason, conventionally, immediately after spinning of an optical fiber, a primary coating is performed on a glass surface with a material having a low elastic modulus, and then a secondary coating is performed with a material having a high elastic modulus.

[0003] In recent years, ultraviolet curable resins have been used from the viewpoint of productivity. Ultraviolet-curable resins are also used for bundling optical fibers with primary and secondary coatings into tapes.

[0004]

An optical fiber cable containing a plurality of coated optical fibers is used in various environments. In an environment such as a pipe or a manhole, the cable is exposed to water. Often immersed.

[0005] In order to prevent the fiber strength from decreasing under such an environment, gas maintenance in which dry air is passed through the cable and waterproof cables in which the cable is filled with a waterproof material have been put into practical use. Unnecessary waterproof cables are increasingly being used.

[0006] The waterproof cable has a structure in which a waterproof material is filled and water can be blocked because there is no method for detecting a minute pinhole when it occurs. However, it is difficult to completely block water only with a waterproof material, and for a long time (for example, 10
Over a period of years), it is difficult to guarantee that the water will not penetrate the protective coating of the fiber or the fiber surface.

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

In addition, there is a problem that water accumulated in a pipe or a manhole is alkaline depending on the location, and the coating layer of the optical fiber is alkali-hydrolyzed.

Japanese Patent Application Laid-Open No. 1-87535 (the applicant of the present invention)
According to Nippon Telegraph and Telephone Corporation), an ultraviolet curable resin composition having a low water absorption hardly hydrolyzes for a long period of time even in the presence of an alkali, and therefore, an optical fiber coated with an ultraviolet curable resin having a low water absorption. The coating layer hardly deteriorates in an alkaline atmosphere, so that the fiber strength can be maintained for a long period of time.

On the other hand, when petroleum jelly, which is a known material as a waterproof material, is filled in a cable, the jelly infiltrates from the coating layer of the fiber, causing a problem that the coating material is deteriorated and the strength of the fiber itself is reduced. there were.

In addition, there is a problem that hydrogen gas generated with time from the cured film diffuses into the optical fiber and causes an increase in transmission loss.

Therefore, from the viewpoint of long-term reliability, it is required that the coating material of the optical fiber has excellent jelly resistance, low water absorption, low hydrogen generation and excellent heat resistance.

An object of the present invention is to provide an ultraviolet-curable resin composition for coating an optical fiber which has excellent jelly resistance, low hydrogen generation, low water absorption, and excellent heat resistance. is there.

[0014]

In order to solve the above problems, the present invention provides (1) (a) a polyether polyol, (b)
Polyisocyanate and (c) 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) a monomer having an ethylenically unsaturated bond, and (3) An ultraviolet-curable resin composition for coating an optical fiber containing a photopolymerization initiator, wherein (1) the polymerizable unsaturated polyurethane contains (a) polyepichlorohydrin ether as a polyether polyol component. To provide an ultraviolet curable resin composition for coating an optical fiber.

The polymerizable unsaturated polyurethane used in the present invention can be obtained by reacting polyepichlorohydrin ether, a hydroxy compound having an acryloyl group, and polyisocyanate.

The polyepichlorohydrin ether which is a ring-opening polymer of epichlorohydrin used in the present invention includes, for example, "Unisafe HUT5001" (manufactured by NOF Corporation).

Examples of the hydroxy compound having an acryloyl group include 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 Acrylate and the like can be mentioned.

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, and trimethyl hexamethylene diisocyanate. , 1,5-naphthalene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate, lysine diisocyanate and the like.

As the monomer having an ethylenically unsaturated bond used in the present invention, an acrylate compound is mainly 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 monomer having an ethylenically unsaturated bond used in the present invention include aromatic vinyl monomers such as styrene, chlorostyrene and divinylbenzene; and methyl, ethyl, propyl, butyl and amyl as substituents. , 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 an 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 Di (meth) acrylate, 2-hydroxyethyl (meth) acrylate 1 of a diol obtained by adding 2 mol or more of ethylene oxide or propylene oxide 1
The reaction product of 1 mol of phenyl isocyanate or 1 mol of n-butyl isocyanate, and poly (meth) acrylate of dipentaerythritol can be exemplified.

Also, N-vinyl-2-pyrrolidone, acryloylmorpholine, vinylimidazole, vinylcaprolactam, vinyl-p-tert-butylbenzoate, cyclohexyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate At least one monomer selected from the group consisting of: can be used, and when used in combination with the above-mentioned (meth) acrylate having two or more functionalities, the curability is improved, a high gel fraction is obtained after curing, and a highly reliable material is provided. be able to.

The photopolymerization initiator used in the present invention includes:
Any material may be used 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 compound such as a combination of an aromatic ketone and a hydrogen donor is used in combination.

Examples of the former include, for example, benzoyl ethyl ether, benzoin isobutyl ether,
Benzyl dimethyl 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.

Examples of the aromatic ketone in the latter case include benzophenone, 4-phenylbenzophenone, isophthalophenone, 4-benzoyl-4'-methyl-diphenylsulfide, 2,4-diethylthioxanthone, 2-isopropyl Thioxanthone, 2-chlorothioxanthone and the like can be mentioned, and as a hydrogen donor to be combined therewith, for example, a mercapto compound and an amine compound can be mentioned, but an amine compound is generally preferable.

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

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 blended for the purpose of improving various properties.

The ultraviolet resin composition for coating an optical fiber of the present invention comprises (1) 10 to 80% by weight of a polymerizable unsaturated polyurethane,
(2) It is preferred that the monomer having an ethylenically unsaturated bond is blended in the range of 10 to 80% by weight and the photopolymerization initiator in the range of 0.1 to 10% by weight.

[0029]

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) 1 mol of polyepichlorohydrin ether (number average molecular weight 2000) and 2 mol of 2,4-tolylene diisocyanate were charged into a reaction vessel equipped with a nitrogen gas inlet tube, a stirrer and a cooling tube. At 70 ° C. for 2 hours.

Next, 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 were gradually added, and the mixture was further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-1).

(Synthesis Example 2) In Synthesis Example 1, polypropylene glycol (number-average molecular weight: 200) was used instead of 1 mol of polyepichlorohydrin ether (number-average molecular weight: 2000).
0) In the same manner as in Synthesis Example 1 except that 1 mol was used,
Polymerizable unsaturated polyurethane having an acryloyl group (A
-2) was obtained.

Examples and comparative examples of the ultraviolet-curable resin composition for coating an optical fiber of the present invention are shown below.

Example 1 50 parts by weight of the polymerizable unsaturated polyurethane (A-1) obtained in Synthesis Example 1, 50 parts by weight of nonylphenoxy polyethylene glycol monoacrylate, and 2,4,6-trimethylbenzoyldiphenylphosphine 2 parts by weight of the oxide were mixed and dissolved at 60 ° C. for 1 hour,
A liquid UV-curable resin composition of 5 poise (25 ° C.) was obtained.

Comparative Example 1 The procedure of Example 1 was repeated, except that the polymerizable unsaturated polyurethane (A-2) was used instead of the polymerizable unsaturated polyurethane (A-1). A liquid UV-curable resin composition having a viscosity of 26 poise (25 ° C.) was obtained.

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

(Evaluation of Jelly Resistance) An ultraviolet curable resin composition was applied on a glass plate so as to have a dry coating thickness of 200 μm, and then irradiated in a nitrogen atmosphere using an 80 W / cm metal halide lamp. The composition was cured at a light quantity of 200 mJ / cm ² . The cured film was conditioned at 23 ° C. and 50% RH to obtain a weight M1.
Is measured. Next, Jerry SYNCOLT (SYN
After immersion in 85 ° C. for 1 day and 7 days at 85 ° C., the sample was taken out, the jelly on the surface was wiped off, and the weight M2 was measured. Weight change = M2 / M1 × 100 (%) was used as an index of jelly resistance.

(Measurement of Hydrogen Generation Amount) An ultraviolet-curable resin composition was applied on a glass plate so as to have a dry coating thickness of 200 μm, and irradiated with a 80 W / cm metal halide lamp in a nitrogen atmosphere. The composition was cured at a light quantity of 200 mJ / cm ² . Put 10g of this cured film into a headspace bottle,
After heating at 0 ° C. for 24 hours, measurement was performed by gas chromatography.

(Measurement of Water Absorption) An ultraviolet curable resin composition was applied on a glass plate so as to have a dry coating thickness of 200 μm, and then irradiated with a metal halide lamp of 80 W / cm in a nitrogen atmosphere. Cured at 200 mJ / cm ² . Using this cured film as a sample, the water absorption was measured in accordance with the method B of JIS K7209.

(Evaluation of heat resistance) The ultraviolet curable resin composition was applied on a glass plate so as to have a dry coating thickness of 200 μm, and then irradiated with a metal halide lamp of 80 W / cm in a nitrogen atmosphere. Cured at 200 mJ / cm ² . The cured film was stored in air at 120 ° C. for one week, and then the tensile modulus was measured in the same manner as described above. The ratio of this measured value to the initial value was used as an index of heat resistance.

[0042]

[Table 1]

[0043]

The ultraviolet-curable resin composition for coating an optical fiber of the present invention has a smaller weight change due to jelly immersion, a smaller amount of hydrogen generation from the cured film, and a lower water absorption than the conventional ultraviolet-curable resin composition. Low rate and excellent heat resistance.

Therefore, an optical fiber coated with the ultraviolet-curable resin composition for coating an optical fiber of the present invention has excellent jelly resistance, low transmission loss due to hydrogen generation, and high reliability even when used for a long time. Can be obtained.

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁷ identification symbol FI C09D 157/00 C09D 157/00 175/00 175/00 (58) Field surveyed (Int.Cl. ⁷ , DB name) C03C 25 / 24 C08F 299/06 C08G 18/48 C08G 18/67 C09D 5/00 C09D 157/00 C09D 175/00

Claims (1)

(57) [Claims] 1. A polymerizable unsaturated compound obtained by reacting (1) (a) a polyether polyol, (b) a polyisocyanate, and (c) a compound having an active hydrogen and a polymerizable unsaturated group which reacts with an isocyanate group. In a saturated polyurethane, (2) a monomer having an ethylenically unsaturated bond and (3) an ultraviolet-curable resin composition for coating an optical fiber containing a photopolymerization initiator, (1) a polymerizable unsaturated polyurethane, (a) An ultraviolet-curable resin composition for coating an optical fiber, comprising a polyepichlorohydrin ether as a polyether polyol component.