Liquid curable resin composition and cured substance thereof

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a liquid curable resin composition having excellent light resistance and a cured product thereof, which is suitable as a coating material for optical fiber strands, optical fiber tapes and the like.

【0002】

[Conventional technology]

An optical fiber is manufactured by coating a glass fiber wire obtained by hot-melt spinning glass with a resin for the purpose of protective reinforcement. As this resin coating, a structure is known in which a flexible primary coating layer is first provided on the surface of an optical fiber, and a secondary coating layer having high rigidity is provided on the outside thereof. A tape-shaped fiber in which a plurality of these resin-coated optical fiber strands are arranged on a flat surface and hardened with a binding material is also well known. The resin composition for forming the primary coating layer of the optical fiber wire is used as the primary material, the resin composition for forming the secondary coating layer is used as the secondary material, and the tape-shaped fiber binding material is used. The resin composition is called a tape material. As these resin coating methods, a method of applying a liquid curable resin composition and curing it with heat or light, particularly ultraviolet rays, is widely used.

【0003】

Since an optical fiber is used for a long period of time, the coating material used for the optical fiber is also required to have little change in characteristics for a long period of time. However, the coating material containing the polymerizable oligomer having the structural unit represented by the formula (1) has many hydrogen atoms on the tertiary carbon atom, which is chemically relatively unstable, so that the characteristics are likely to change. There was a problem.

【0004】

[Chemical 3]

-CH₂CH (CH)₃) O- (1) [0005]

[Problems to be Solved by the Invention]

An object of the present invention is to provide a liquid curable resin composition in which the characteristics of the cured product do not change for a long period of time and the cured product has excellent light resistance.

【0006】

[Means for solving problems]

In order to solve the above problems, the present invention contains a polymerizable oligomer (A) having a structural unit represented by the formula (1), a phenolic antioxidant (B), and an ultraviolet absorber (C). Provided are a characteristic liquid curable resin composition and a cured product of the composition.

【0007】

[Chemical 4]

-CH₂CH (CH)₃) O- (1) [0008]

BEST MODE FOR CARRYING OUT THE INVENTION

The polymerizable oligomer (A) having the structural unit represented by the formula (1) used in the present invention is an oligomer having both the structural unit of the formula (1) and the polymerizable double bond, and is, for example, of the formula (1). Oligomers having a structural unit and a (meth) acrylic group can be mentioned, and an isocyanate group of a diisocyanate can be obtained by using a polyether polyol having a structural unit represented by the formula (1), a diisocyanate compound, and a hydroxyl group-containing (meth) acrylate. More preferably, a polymerizable oligomer obtained by reacting with a hydroxyl group of a polyether polyol or a hydroxyl group of a hydroxyl group-containing (meth) acrylate. The ratio of the polyether polyol, the diisocyanate compound and the hydroxyl group-containing (meth) acrylate used for the synthesis of the polymerizable oligomer (A) is 1.1 to 1.1 to the isocyanate group contained in the diisocyanate compound with respect to 1 equivalent of the hydroxyl group contained in the polyether polyol. It is preferable that the hydroxyl group of the hydroxyl group-containing (meth) acrylate has 2 equivalents and 0.1 to 1 equivalent.

【0009】

As a specific method for carrying out this reaction, for example, a method in which a polyether polyol, a diisocyanate compound and a hydroxyl group-containing (meth) acrylate are collectively charged and reacted; a polyether polyol and a diisocyanate compound are reacted, and then a hydroxyl group-containing (meth) acrylate is reacted. ) Method of reacting acrylate; Reaction of diisocyanate compound and hydroxyl group-containing (meth) acrylate, then reaction of polyether polyol; Reaction of diisocyanate compound and hydroxyl group-containing (meth) acrylate, then reaction of polyether polyol, Finally, there is also a method of reacting a hydroxyl group-containing (meth) acrylate.

【0010】

Examples of the polyether polyol having the structural unit represented by the formula (1) used for the synthesis of the polymerizable oligomer (A) include polypropylene glycol, propylene oxide and one or more other ion-polymerizable cyclic compounds. Examples thereof include polyether polyols obtained by copolymerization. Examples of the ion-polymerizable cyclic compound include ethylene oxide, butene-1-oxide, isobutene oxide, 3,3-bischloromethyloxetane, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, dioxane, trioxane, tetraoxane, and cyclohexene oxide. , Styrene oxide, epichlorohydrin, glycidyl methacrylate, allyl glycidyl ether, allyl glycidyl carbonate, butadiene monooxide, isoprene monooxide, vinyl oxetane, vinyl tetrahydrofuran, vinyl cyclohexene oxide, phenyl glycidyl ether, butyl glycidyl ether, glycidyl benzoate, etc. Examples include ethers. The average number of functional groups (for example, the number of hydroxy groups) of these polyether polyols is preferably 1.5 to 6.0 from the viewpoint of obtaining a good gel fraction of the cured product of the present invention and an appropriate viscosity of the liquid curable resin composition.

【0011】

The above-mentioned polyether polyol can also be used as a commercial product such as EXCENOL720, 1020, 2020, 3030, 4030, PREMINOL3010, 4002, 4010 (above, manufactured by Asahi Glass Urethane), PPTG2000, PPTG1000, (above, manufactured by Hodogaya Chemical Co., Ltd.). You can get it.

【0012】

Examples of the diisocyanate compound used for the synthesis of the polymerizable oligomer (A) include aromatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates. Examples of aromatic diisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalenedi isocyanate, and m-phenylenedi isocyanate. , P-phenylenediocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethylphenylenediocyanate, 4,4'-biphenylenediocyanate, bis (2- Isocyanate ethyl) fumarate, 6-isopropyl-1,3-phenyldiisocyanate, 4-diphenylpropanediisocyanate, tetramethylxylylene diisocyanate and the like can be mentioned. Examples of alicyclic diisocyanates include isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, 2,5-bis (isocyanate methyl) -bicyclo [2.2.1] heptane, 2 , 6-bis (isocyanate methyl) -bicyclo [2.2.1] heptane and the like. Examples of the aliphatic diisocyanate include 1,6-hexane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Of these, aromatic diisocyanates and alicyclic diisocyanates are more preferable, and 2,4-toluene diisocyanates and isophorone diisocyanates are particularly preferable. These diisocyanate compounds may be used alone or in combination of two or more.

【0013】

The hydroxyl group-containing (meth) acrylate used for the synthesis of the polymerizable oligomer (A) is a hydroxyl group-containing (meth) acrylate in which a hydroxyl group is bonded to a primary carbon atom in terms of reactivity with the isocyanate group of the diisocyanate compound. A primary hydroxyl group-containing (meth) acrylate) and a hydroxyl group-containing (meth) acrylate in which a hydroxyl group is bonded to a secondary carbon atom (referred to as a secondary hydroxyl group-containing (meth) acrylate) are preferable. Examples of the primary hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, and the like. Dipentaerythritol penta (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethanedi (meth) acrylate, and the following formula (2) [0014]

[Chemical 5]

CH₂= C (R)¹)-COOCH₂CH₂-(OCOCH₂CH₂CH₂CH₂CH₂)_n-OH (2) [0015]

(In the formula, R¹Indicates a hydrogen atom or a methyl group, and n indicates a number of 1 to 3) (meth) acrylate and the like. Examples of the second hydroxyl group-containing (meth) acrylate include 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, and 4-hydroxycyclohexyl (meth). ) Acrylate and the like, and further examples thereof include a compound obtained by an addition reaction between a glycidyl group-containing compound such as alkyl glycidyl ether, allyl glycidyl ether and glycidyl (meth) acrylate and (meth) acrylic acid.

【0016】

In the synthesis of polymerizable oligomer (A), copper naphthenate, cobalt naphthenate, zinc naphthenate, dibutyltin dilaurate, triethylamine, 1,4-diazabicyclo [2.2.2] octane, 2,6,7-trimethyl-1 , 4-Diazabicyclo [2.2.2] It is preferable to use a urethanization catalyst such as octane in an amount of 0.01 to 1% by weight based on the total amount of the reactants. The reaction temperature is usually 5 to 90 ° C, particularly preferably 10 to 80 ° C.

【0017】

The preferred molecular weight of the polymerizable oligomer (A) is the polystyrene-equivalent number average molecular weight obtained by the gel permeation chromatograph method from the viewpoint of obtaining good elongation at break of the cured product of the present invention and appropriate viscosity of the liquid curable resin composition. Usually 500 to 40,000, more preferably 700 to 30,000.

【0018】

The polymerizable oligomer (A) is contained in the liquid curable resin composition of the present invention from the viewpoint of obtaining good mechanical properties such as elongation at break of the cured product of the present invention and an appropriate viscosity of the liquid curable resin composition. It is preferably blended in an amount of up to 85% by weight, particularly 25 to 80% by weight.

【0019】

It is also possible to use diamine together with polyether polyol in the synthesis of polymerizable oligomer (A), and such diamines include ethylenediamine, tetramethylenediamine, hexamethylenediamine, paraphenylenediamine, and 4,4'-diamino. Examples thereof include diamines such as diphenylmethane, diamines containing heteroatoms, polyether diamines and the like.

【0020】

It is also possible to replace a part of the hydroxyl group-containing (meth) acrylate with a compound having a functional group that can be added to the isocyanate group. Examples of this compound include γ-aminopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane. By using these compounds, the adhesion to a substrate such as glass can be further enhanced.

【0021】

As the phenolic antioxidant (B) used in the present invention, those having the structure of the formula (3) or the formula (4) are more preferable.

【0022】

[Chemical 6]

<img file="JP2000302829A_D0001.tif" />【0023】

As a phenolic antioxidant having the structure of formula (3), for example, 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1 , 1-Dimethylethyl] -2,4,8,10-Tetraoxaspiro [5.5] undecane, triethylene glycol-bis {3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate}, etc. Can be mentioned. Examples of the phenolic antioxidant having the structure of the formula (4) include pentaerythrityl-tetrakis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}, 2,2-thio-. Diethylenebis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 3,5- Examples thereof include di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester. These commercial products include IRGANOX 245, 1010, 1035, 1076, 1222 (all manufactured by Ciba Specialty Chemicals), Sumilizer. Examples include GA-80 and BP101 (manufactured by Sumitomo Chemical Co., Ltd.). Of these, 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10 -Tetraoxaspiro [5.5] undecane, triethylene glycol-bis {3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate}, 2,2-thio-diethylenebis {3- (3,, 5-Di-t-butyl-4-hydroxyphenyl) propionate} is particularly preferred.

【0024】

These phenolic antioxidants (B) are contained in the liquid curable resin composition of the present invention by 0.1 to 3 weights in terms of the effect of reducing changes in the physical properties of the cured product of the present invention and the curability of the liquid curable resin composition. %, Especially preferably 0.15 to 1.5% by weight.

【0025】

As the ultraviolet absorber (C) used in the present invention, for example, a benzophenone-based ultraviolet absorber, a benzotriazole-based ultraviolet absorber, or the like can be used. Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 2,2'-di-hydroxy-4-methoxybenzophenone. Examples of benzotriazole-based ultraviolet absorbers include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-t-butylphenyl) benzotriazole, 2- Examples thereof include (2'-hydroxy-5'-t-octylphenyl) benzotriazole, 2,4-di-t-butylphenyl-3', 5'-di-t-butyl-4'-hydroxybenzotriazole and the like. .. Of these, a benzophenone-based ultraviolet absorber is particularly preferable from the viewpoint of improving the light resistance of the cured product of the present invention. These commercial products include Sumisorb 110, 130, 140 (above, manufactured by Sumitomo Chemical), Seesorb 102, 103, 501, 202, 712, 704 (above, manufactured by Cipro Kasei), TINUVIN. P, 234, 320, 326, 327, 328, 329, 213 (all manufactured by Ciba Specialty Chemicals) and the like can be mentioned. Of these, 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-octoxybenzophenone are particularly preferable.

【0026】

These ultraviolet absorbers (C) are contained in the liquid curable resin composition of the present invention in an amount of 0.05 to 3% by weight from the viewpoint of reducing the change in physical properties of the cured product of the present invention and the curability of the liquid curable resin composition. , It is preferable to blend 0.1 to 1.5% by weight.

【0027】

The composition of the present invention is usually used by blending a polymerizable unsaturated monomer (D) and a polymerization initiator (E).

【0028】

As the polymerizable unsaturated monomer (D), a monofunctional compound and / or a polyfunctional compound can be used. Examples of the monofunctional compound include vinyl group-containing lactams such as N-vinylpyrrolidone and N-vinylcaprolactam; isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and dicyclopentanyl ( Alicyclic structure-containing (meth) acrylates such as meta) acrylate, dicyclopentenyl (meth) acrylate, cyclohexyl (meth) acrylate; benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, acryloylmorpholine, vinyl imidazole, Vinyl pyridine and the like can be mentioned. Furthermore, the following formula (5) [0029]

[Chemical 7]

CH₂= C (R)²)-COO (R)³O)_m-R⁴ (5) 【0030】

(In the formula, R²Indicates a hydrogen atom or a methyl group, R³Indicates an alkylene group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, and R⁴Represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, preferably 1 to 9, and m indicates a number of 0 to 12, preferably 1 to 8) (meth) acrylates; tetrahydrofurfuryl. Ether group-containing (meth) acrylates such as (meth) acrylates and phenoxyethyl (meth) acrylates; dimethylaminoethyl (meth) acrylates, diethylaminoethyl (meth) acrylates, 7-amino-3,7-dimethyloctyl (meth) acrylates. Amino group-containing (meth) acrylates such as diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, N, N-diethyl (meth) (Meta) acrylamides such as acrylamide and N, N-dimethylaminopropyl (meth) acrylamide; vinyl ethers such as hydroxybutyl vinyl ethers, lauryl vinyl ethers, cetyl vinyl ethers and 2-ethylhexyl vinyl ethers can be mentioned. Among these, the (meth) acrylates represented by the formula (5) include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. Meta) acrylate;

【0031】

In addition, as commercially available products of the monofunctional compounds of the above polymerizable unsaturated monomers, Aronix M111, M113, M114, M117 (above, manufactured by Toagosei); KAYARAD, TC110S, R629, R644 (above, Nippon Kayaku). (Manufactured); IBXA, Viscort 3700 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), etc.

【0032】

Examples of the polyfunctional compound include trimethyl propantri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. , 1,4-Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylpropantrioxyethyl (meth) acrylate, tris (2-hydroxyethyl) ) Isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, ethylene oxide of bisphenol A or didiol of propylene oxide adduct. (Meta) acrylate, di (meth) acrylate of ethylene oxide of hydrogenated bisphenol A or diol of propylene oxide adduct, epoxy (meth) acrylate of diglycidyl ether of bisphenol A with (meth) acrylate added, triethylene Glycoldivinyl ether and the like can be mentioned. Commercially available products of these polyfunctional compounds include, for example, Yupimer UV SA1002, SA2007 (above, manufactured by Mitsubishi Chemical Corporation); Viscort 700 (manufactured by Osaka Organic Chemical Industry Co., Ltd.); KAYARAD R-604, DPCA-20, -30, -60, -120, HX-620, D-310, D-330 (above, manufactured by Nippon Kayaku); Aronix M-210, M-215, M-315, M-325 (above, manufactured by Toagosei), etc. ..

【0033】

These polymerizable unsaturated monomers (D) can be used alone or in combination of two or more.

【0034】

These polymerizable unsaturated monomers (D) have the liquid curable resin composition of the present invention from the viewpoint of obtaining good properties such as elongation at break of the cured product of the present invention and an appropriate viscosity of the liquid curable resin composition. It is preferable to add 10 to 80% by weight, particularly 15 to 75% by weight, in the product.

【0035】

Examples of the polymerization initiator (E) used in the present invention include a thermal polymerization initiator or a photopolymerization initiator. Examples of the thermal polymerization initiator include peroxides and azo compounds. Specific examples thereof include benzoyl peroxide, t-butyl-oxybenzoate, and azobisisobutyronitrile.

【0036】

Further, when the liquid curable resin composition of the present invention is photocured, a photosensitizer can be added as needed in addition to the photopolymerization initiator. Here, examples of the photopolymerization initiator include 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, and the like. 4-Chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler ketone, benzoin propyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2- Methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) ) Phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphoffin oxide And so on. Its commercial products include IRGACURE184, 369, 651, 500, 907, CGI1700, CGI1750, CGI1850, CG24-61, DAROCUR1116, 1173 (above, made by Ciba Specialty Chemicals); LUCIRIN TPO (made by BASF); Yubekrill P36 (made by UCB) and the like can be mentioned. Examples of the photosensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and 4-dimethylaminobenzoic acid. Examples thereof include isoamyl acid. Examples of the commercially available product include Yubekrill P102, 103, 104, 105 (all manufactured by UCB) and the like.

【0037】

When the liquid curable resin composition of the present invention is cured by using heat and ultraviolet rays in combination, the thermosetting initiator and the photopolymerization initiator can also be used in combination. The polymerization initiator (E) is preferably blended in the liquid curable composition of the present invention in an amount of 0.1 to 10% by weight, particularly 0.3 to 7% by weight.

【0038】

The composition of the present invention may be blended with an organic sulfur-based secondary antioxidant and a phosphite-based secondary antioxidant, if necessary. Examples of the organic sulfur-based secondary antioxidant include IRGANOX PS800FL, PS802FL (all manufactured by Ciba Specialty Chemicals), Sumilizer TL, MB (manufactured by Sumitomo Chemical Co., Ltd.) and the like. Examples of the phosphite-based secondary antioxidant include Sumilizer TNP, TPP-R, P-16 (manufactured by Sumitomo Chemical Co., Ltd.) and the like.

【0039】

The composition of the present invention includes other curable oligomers, polymers, non-curable sensitizers, other additives and the like, if necessary, as long as the characteristics of the liquid curable resin composition of the present invention are not impaired. Can be blended.

【0040】

Examples of other curable oligomers and polymers include polyester (meth) acrylate, epoxy (meth) acrylate, polyamide (meth) acrylate, siloxane polymer having (meth) acryloyloxy group, and glycidyl methacrylate.

【0041】

In addition to the above components, various additives such as colorants, light stabilizers, silane coupling agents, thermal polymerization inhibitors, leveling agents, surfactants, storage stabilizers, plasticizers, lubricants, solvents, fillers, and anti-aging agents. An agent, a wettability improving agent, a coating surface improving agent and the like can be blended as needed. Examples of the light stabilizer include TINUVIN 292, 144, 622LD (manufactured by Ciba Specialty Chemicals), Sanol LS770 (manufactured by Sankyo), TM-061 (manufactured by Sumitomo Chemical Co., Ltd.) and the like. Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane, and commercially available products such as SH6062 and 6030 (manufactured by Toredau Corning Silicone). , KBE903, 603, 403 (above, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

【0042】

The liquid curable resin composition of the present invention is cured by heat and / or radiation, wherein the radiation includes infrared rays, visible rays, ultraviolet rays, X-rays, electron beams, α rays, β rays, γ rays and the like. However, ultraviolet rays can be particularly preferably used.

【0043】

Preferred embodiments of the present invention are as follows. 1) A polymerizable oligomer (A) having a structural unit represented by the formula (1), a phenolic antioxidant (B), an ultraviolet absorber (C), a polymerizable unsaturated monomer (D), and polymerization initiation. A liquid curable resin composition containing the agent (E). 2) Phenolic antioxidant (B) is 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-Tetraoxaspiro [5.5] undecane, triethylene glycol-bis {3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate}, or 2,2-thio -Diethylenebis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}, UV absorber (C) is 2-hydroxy-4-methoxybenzophenone, or 2-hydroxy-4- The composition according to 1) above, which is octoxybenzophenone. 3) The polymerizable oligomer (A) is obtained by reacting a polyether polyol obtained by ring-opening copolymerization of polypropylene glycol or propylene oxide with one or more other ion-polymerizable cyclic compounds, a diisoialate compound, and a hydroxyl group-containing acrylate. The composition according to 2) above, which is an oligomer having a molecular weight of 500 to 40,000 in terms of polystyrene obtained by a gel permeation chromatograph method. 4) The contents of the polymerizable oligomer (A), the phenolic antioxidant (B), the ultraviolet absorber (C), the polymerizable unsaturated monomer (D), and the polymerization initiator (E) are 20 respectively. The composition according to 1), 2) or 3) above, which is in the proportions of ~ 85% by weight, 0.1 to 3% by weight, 0.05 to 3% by weight, 10 to 80% by weight, and 0.1 to 10% by weight.

【0044】

[Example]

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

【0045】

Synthesis Example 1 (Synthesis example of polymerizable oligomer) In a reaction vessel equipped with a stirrer, 868.8 g of polypropylene glycol having a number average molecular weight of 3000, 96.4 g of isophorone diisocyanate, 0.02 g of 2,6-di-t-butyl-p-cresol, and 0.008 g of phenothiazine were charged, and these were charged. The mixture was cooled with stirring until the liquid temperature reached 15 ° C. After adding 0.08 g of dibutyltin dilaurate, the liquid temperature was gradually raised to 35 ° C over 1 hour with stirring. After that, the liquid temperature was raised to 50 ° C and the reaction was carried out. After the residual isocyanate group concentration became 1.26% by weight (ratio to the charged amount; the same applies hereinafter), 33.6 g of 2-hydroxyethyl acrylate was added, and the mixture was stirred and reacted at a liquid temperature of about 60 ° C. When the residual isocyanate group concentration became 0.1% by weight or less, the reaction was terminated to obtain a polymerizable oligomer (this is referred to as the polymerizable oligomer (a)).

【0046】

Examples 1 to 4, Comparative Examples 1 to 3 The compounds were charged in a reaction vessel equipped with a stirrer at the compounding ratio (weight ratio) shown in Table 1 and stirred at a liquid temperature of 50 ° C. until a uniform solution was obtained to obtain the compositions of Examples and Comparative Examples.

【0047】

Test example (light resistance test method) With respect to the compositions obtained in Examples and Comparative Examples, the light resistance of the cured product was measured. The liquid composition was applied onto the glass using a 254 μm thick applicator, and 0.1 J / cm in a nitrogen atmosphere using a 3.5 kW metal halide lamp (Oak SMX-3500 / F-OS).²A cured film having a thickness of about 130 μm was obtained by irradiating with the ultraviolet rays of. This cured film was placed on a white paper pattern and irradiated with fluorescent light for 3 months in an environment with a temperature of 23 ° C and a humidity of 50% RH. At this time, the fluorescent lamp tube used was Toshiba FL20SSN / 18, and the illuminance on the cured film was 1200 lx. The cured film before and after irradiation with fluorescent lamp light was cut into a width of 0.6 cm to obtain a test piece for measuring the elastic modulus. Using this, the elastic modulus is measured in accordance with JIS7127 in an environment with a tensile speed of 1 mm / min, a distance between marked lines of 25 mm, a temperature of 23 ° C, and a humidity of 50% RH, and curing before irradiation with fluorescent lamp light. The elastic modulus of the film and the elastic modulus of the cured film after irradiation were obtained. The light resistance was evaluated by the ratio of these elastic moduli (elastic modulus of the cured film after irradiation / elastic modulus of the cured film before irradiation).

【0048】

Each component in Table 1 is as follows. Phenolic Antioxidant A: 2,2-thio-diethylenebis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] Phenolic Antioxidant B: Triethylene Glycol-Bis {3- (3-t-Butyl-5-Methyl-4-Hydroxyphenyl) Propionate} Phenolic Antioxidant C: 3,9-bis [2- {3- (3-t-Butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4 , 8,10-Tetraoxaspiro [5.5] Undecane Benzophenone UV absorber A: 2-Hydroxy-4-methoxybenzophenone Benzophenone UV absorber B: 2-Hydroxy-4-octoxybezophenone Benzotriazole system UV absorber C: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole Photostabilizer A: Dimethyl-1- (2-hydroxyethyl) succinate-4-hydroxy-2,2,6,6-tetramethylpiperidine polymerization condensate Photoinitiator A : 2,4,6-trimethylbenzoyldiphenylphosphine oxide Silane coupling material A: γ-mercaptopropyltrimethoxysilane [0049]

[table 1]

<img file="JP2000302829A_D0002.tif" />【0050】

From Table 1, it is clear that the cured film obtained by the liquid curable resin composition in which the polymerizable oligomer (A) is mixed with a phenolic antioxidant and an ultraviolet absorber has excellent light resistance.

【0051】

[Effect of the invention]

The cured product obtained by the liquid curable resin composition of the present invention has excellent light resistance and is useful as a coating material for optical fibers.