JP2005060631A - Radiation-curable liquid resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which is excellent in long range stability, has a good workability in coating optical fiber because of its low viscosity although Young's modulus in its cured state is about 50-1,200 MPa, has a high curing rate and the cured product shows an excellent surface property, and is excellent in resistance against UV light, heat, heat yellowing and oil. <P>SOLUTION: The radiation-curable liquid resin composition contains a 65-90 wt% urethane (meth)acrylate (A) and a 1-35 wt% monomer (B) represented by formula (1), wherein R<SP>1</SP>is a hydrogen atom or a methyl group, R<SP>2</SP>and R<SP>3</SP>are each independently a hydrogen atom or a 1-4C alkyl group, R<SP>4</SP>is a hydrogen atom or a methyl group and n is a number of 1-6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radiation curable liquid resin composition useful as an optical fiber coating and cable material, and in particular, it has a low curing rate and is easy to use, while having a fast curing rate, while the Young's modulus of the cured product is about 50 to 1200 MPa. The present invention relates to a radiation curable liquid resin composition having good dilutability, low yellowing of a cured product, excellent surface characteristics of the cured product, and useful as an optical fiber coating material.

  In the optical fiber industry, radiation curable liquid resin compositions are widely used in the manufacturing process of optical fibers, ribbons and cables. For example, an optical glass fiber is coated with a radiation curable coating of at least one layer, most often two layers, immediately after being drawn from the base material so as to maintain the intrinsic properties of the glass fiber. It is also usually called “heart”. Immediately after the coating of each layer is applied, the coating is usually rapidly cured by UV irradiation. There is a need in the art for coating compositions that cure faster in order to achieve higher production rates of optical fibers. The radiation curable matrix material and bundling material can further support and protect the individual cores of the coated fiber when the cores are bundled into optical fiber ribbons, optical fiber cables and related structures. . In addition, the radiation curable ink can be used to identify each optical fiber with a color code. All of these optical fiber coating materials are preferably radiation curable. The first coating layer that is in direct contact with the glass fiber is referred to as a primary coating layer, and is a flexible coating layer that prevents minute bending of the glass fiber. The second coating layer in contact with the outer side of the primary coating is called a secondary coating layer, which is a tougher coating layer that gives the glass fiber a more durable exterior.

  There are many reports on these optical fiber coating technologies (Patent Documents 1 to 6). Representative primary coating materials (Patent Literature 1, Patent Literature 7), secondary coating materials (Patent Literature 8) and other coating materials (Patent Literature 9, Patent Literature 10) have been reported.

  The curing rate of the radiation curable liquid resin composition that is an optical fiber coating material is greatly influenced by the type of (meth) acrylate monomer used. In order to provide an appropriate balance between the surface and internal curing rates of the coating layer, it is common to use several (meth) acrylate monomers in combination. In order to increase the curing rate of the coating layer, various (meth) acrylate monomers are conventionally used, and N-vinyl monomers such as N-vinylcaprolactam are also used.

However, when N-vinyl monomer is used, yellowing may occur in the fiber coating layer. Therefore, a (meth) acrylate monomer capable of achieving both fast curability and low yellowing has been demanded. In particular, for matrix materials and bundling materials, a low-viscosity and easy-to-use coating material has been required while having a Young's modulus of a cured product of about 100 to 1000 MPa.
US Pat. No. 5,336,563 US Pat. No. 5,595,820 US Pat. No. 5,1990,988 U.S. Pat. No. 4,923,915 U.S. Pat. No. 4,720,529 U.S. Pat. No. 4,474,830 US Pat. No. 4,992,524 Japanese Patent Laid-Open No. 10-81705 JP 11-49534 A US Pat. No. 5,146,531

  The object of the present invention is that the cured product has a Young's modulus of about 50 to 1200 MPa, and is easy to use with a low viscosity, a high curing rate, good dilution, low yellowing of the cured product, and further to the surface characteristics of the cured product. An object of the present invention is to provide a radiation curable liquid resin composition which is excellent and useful as an inner primary coating, an outer primary coating, a matrix material, a bundling material, an ink and the like in an optical fiber.

  As a result of earnest research in view of such a situation, the present inventor has at least an ethylenically unsaturated bond and a vinyl ether group in the molecule in a radiation curable liquid resin composition containing a high content of urethane (meth) acrylate. The inventors have found that the above problem can be solved by adding one kind of monomer, and have completed the present invention.

That is, the present invention includes the following components (A) and (B):
(A) 65 to 90% by weight of urethane (meth) acrylate,
(B) 1 to 35% by weight of a monomer represented by the following formula (1)

[In Formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴ represents a hydrogen atom or a methyl group. N represents a number from 1 to 6. ]
The radiation curable liquid resin composition containing this is provided.

  The radiation curable liquid resin composition of the present invention is easy to use with a low viscosity while the Young's modulus of the cured product is about 50 to 1200 MPa, has a high curing rate, good dilutability, and low yellowing of the cured product, Further, a cured product having excellent surface characteristics can be obtained. Therefore, it is useful as an inner primary coating, an outer primary coating, a matrix material, a bundling material, an ink, etc. in an optical fiber, and particularly, as a matrix material and a bundling material.

  The urethane (meth) acrylate which is the component (A) of the present invention is not particularly limited. For example, (a) a polyol compound, (b) a polyisocyanate compound, and (c) a hydroxy-functional ethylenically unsaturated monomer. Although obtained by reacting, it can also be obtained by reacting only (b) a polyisocyanate compound and (c) a hydroxy-functional ethylenically unsaturated monomer. (A) Urethane (meth) acrylate, for example, (a) at least one end of a polyol compound is a reaction product obtained from the reaction of (b) a polyisocyanate and (c) a hydroxy-functional ethylenically unsaturated monomer, and is end-capped. It has an (end-cap) structure. Here, the term “end cap” means that a functional group is added to the end of the (a) polyol compound. This end cap structure is bonded to the (a) polyol compound via a urethane bond. This urethane reaction takes place in the presence of a catalyst. Examples of the urethane reaction catalyst include dibutyltin dilaurate and diazabicyclooctane crystals.

  (A) The urethane (meth) acrylate preferably contains at least two ethylenically unsaturated groups bonded to the oligomer main chain. For example, ethylenically unsaturated groups may be present as reactive end groups at each end of the oligomer backbone. The main chain of the oligomer can be based on, for example, polyethers, polyolefins, polyesters, polycarbonates, hydrocarbons, or copolymers thereof. The main chain of the oligomer is preferably a polyol prepolymer such as polyether polyol, polyolefin polyol, polycarbonate polyol, or a mixture thereof. The molecular weight of the polyol prepolymer is preferably 700 to 10,000, more preferably 1,000 to 5,000, and most preferably 1,000 to 3,000.

  (A) The oligomer main chain of urethane (meth) acrylate may be, for example, one or more oligomer blocks linked to each other via a urethane bond. For example, one or more polyol prepolymers can be combined by a method known in the art. If the polyol prepolymer is a polyether polyol, a coating having a low glass transition point and good mechanical properties can be obtained. When the main chain of the oligomer is a polyolefin polyol, a coating with further improved water resistance can be obtained. Polycarbonate oligomers can be prepared, for example, by reaction of (a) polycarbonate polyol, (b) polyisocyanate, and (c) an ethylenically unsaturated monomer of a hydroxy functional group.

  As a specific method for producing this (A) urethane (meth) acrylate, for example, (a) polyol, (b) polyisocyanate compound and (c) hydroxy functional ethylenically unsaturated monomer are charged all at once and reacted. A method of reacting (a) a polyol and (b) a polyisocyanate compound, and then reacting (c) a hydroxy-functional ethylenically unsaturated monomer; (b) a polyisocyanate compound and (c) a hydroxy-functional compound A method in which (a) a polyol is reacted; (b) a polyisocyanate compound and (c) a hydroxy-functional ethylenically unsaturated monomer, and then (a) a polyol. And finally (c) the hydroxy-functional ethylenically unsaturated monomer And a method to.

In the reaction between the hydroxyl group of the polyol (a) and the isocyanate group of (b), a stoichiometric balance can be achieved between the hydroxy functionality and the isocyanate functionality, and the reaction temperature can be maintained at 25 ° C. or higher. preferable. Hydroxy functionality should be substantially consumed. The molar ratio of isocyanate to hydroxy functional ethylenically unsaturated monomer is 3: 1 to 1.2: 1, preferably 2: 1 to 1.5: 1. The hydroxy functional ethylenically unsaturated monomer is bonded to the isocyanate via a urethane bond. Examples of the monomer having a (meth) acrylate functional group include hydroxy-functional acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate. Examples of the monomer having a vinyl ether functional group include 4-hydroxybutyl vinyl ether and triethylene glycol monovinyl ether. Examples of monomers having maleate functional groups include maleic acid and hydroxy functional maleates.

  (A) Polyether diol, polyester diol, polycarbonate diol, polycaprolactone diol and the like can be used as the (a) polyol used for the synthesis of urethane (meth) acrylate. Of these, polyether diols are preferred, but other diols can be used in combination with the polyether diol. The polymerization mode of these structural units is not particularly limited, and may be any of random polymerization, block polymerization, and graft polymerization.

  As the polyether diol, a polymer obtained by ring-opening polymerization of a kind of ion-polymerizable cyclic compound such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, polydecamethylene glycol. Examples thereof include polyether diols obtained by ring-opening copolymerization of ether olefin diols or two or more ion-polymerizable cyclic compounds. Examples of the ion polymerizable cyclic compound include ethylene oxide, propylene oxide, butene-1-oxide, isobutene oxide, oxetane, 3,3-dimethyloxetane, 3,3-bischloromethyloxetane, tetrahydrofuran, 2-methyltetrahydrofuran, and 3-methyl. Tetrahydrofuran, dioxane, trioxane, tetraoxane, 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 Cyclic ethers such as glycidyl ether and benzoic acid glycidyl ester Ethers, and the like.

  Polyether diol obtained by ring-opening copolymerization of the above ion polymerizable cyclic compound with cyclic imines such as ethyleneimine, cyclic lactone acids such as γ-propiolactone and glycolic acid lactide, or dimethylcyclopolysiloxanes. Can also be used. Specific combinations of the two or more kinds of ion-polymerizable cyclic compounds include tetrahydrofuran and propylene oxide, tetrahydrofuran and 2-methyltetrahydrofuran, tetrahydrofuran and 3-methyltetrahydrofuran, tetrahydrofuran and ethylene oxide, propylene oxide and ethylene oxide, butene-1- Examples thereof include terpolymers of oxide and ethylene oxide, tetrahydrofuran, butene-1-oxide, and ethylene oxide. The ring-opening copolymer of these ion-polymerizable cyclic compounds may be bonded at random or may be bonded in a block form.

  Of these polyether diols, polypropylene glycol is more preferable from the viewpoint of imparting jelly resistance and water resistance to the cured product of the resin composition of the present invention, and the number in terms of polystyrene by gel permeation chromatography (GPC method). Polypropylene glycol having an average molecular weight of 1,000 to 3,000 is particularly preferred.

When a polyether olefin diol is used, the polyolefin is preferably a linear or branched hydrocarbon having a plurality of hydroxyl end groups. This hydrocarbon is preferably a non-aromatic compound which consists mainly of a methylene group (—CH ₂ —) and may contain unsaturated bonds present in the main chain and unsaturated groups pendant as side groups. . As the degree of unsaturation decreases, the long-term stability of the cured optical fiber coating increases, so fully saturated, for example, hydrogenated hydrocarbons are preferred. Examples of hydrocarbon diols include, for example, 1,2-polybutadiene having a hydroxyl group at the end and fully or partially hydrogenated; 1,4 1,2-polybutadiene copolymer; 1,2-polybutadiene -Ethylene or -propylene copolymer; polyisobutylene polyol; a mixture thereof. As the hydrocarbon diol, 1,2-polybutadiene or 1,2-polybutadiene / ethylene copolymer almost completely hydrogenated is preferable.

  In the case of using a polyether diol obtained by ring-opening copolymerization of a polyether olefin diol or two or more kinds of ion-polymerizable cyclic compounds, it preferably has an average of two or more hydroxyl groups. The oligomer main chain polyol may have an average of more than two hydroxyl groups. Examples of such oligomeric diols include polyether diols, polyolefin diols, polyester diols, polycarbonate diols, and mixtures thereof. Polyether diols, polyolefin diols, or combinations thereof are preferred. When polyether diol is used, it is preferably a substantially non-crystalline polyether. The polyether preferably contains one or more repeating units selected from the group of monomer units described below.

—O—CH ₂ —CH ₂ —
—O—CH ₂ —CH (CH ₃ ) —
—O—CH ₂ —CH ₂ —CH ₂ —
_{-O-CH (CH 3) -CH} 2 -CH 2 -
_{-O-CH 2 -CH (CH 3} ) -CH 2 -
—O—CH ₂ —CH ₂ —CH ₂ —CH ₂ —
_{-O-CH 2 -CH (CH 3} ) -CH 2 -CH 2 -
—O—CH (CH ₃ ) —CH ₂ —CH ₂ —CH ₂ —

  An example of a polyether polyol that can be used is the reaction product of 20% by weight of 3-methyltetrahydrofuran and 80% by weight of tetrahydrofuran. This polyether copolymer has both branched and unbranched oxyalkylene repeating units and is commercially available as PTGL1000 (Hodogaya Chemical Co., Ltd.). Another example of a polyether that can be used in this series is PTGL2000 (Hodogaya Chemical Co., Ltd.).

  These polyether diols include, for example, PTMG650, PTMG1000, PTMG2000 (manufactured by Mitsubishi Chemical Corporation), Exenol 1020, 2020, 3020, Preminol PML-4002, PML-5005 (manufactured by Asahi Glass Co., Ltd.), Unisafe DC1100. DC1800, DCB1000 (manufactured by NOF Corporation), PPTG1000, PPTG2000, PPTG4000, PTG400, PTG650, PTG1000, PTG2000, PTG-L1000, PTG-L2000 (manufactured by Hodogaya Chemical Co., Ltd.), Z- 3001-4, Z-3001-5, PBG2000 (above, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Acclaim 2200, 2220, 3201, 3205, 4200, 4220, 8200, 12 00 can be obtained as (or more Lion Dale Co., Ltd.) commercially available products such as.

  An example of a polycarbonate diol is that produced by alcoholysis of diethylene carbonate with a diol. The diol may be an alkylene diol having 2 to 12 carbon atoms such as 1,4-butanediol, 1,6-hexanediol, 1,12-dodecanediol, and the like. Mixtures of these diols can also be used. The polycarbonate diol can contain an ether bond in the main chain in addition to the carbonate group. Therefore, for example, a polycarbonate copolymer of an alkylene oxide monomer and the aforementioned alkylene diol can be used. Examples of the alkylene oxide monomer include ethylene oxide and tetrahydrofuran. These copolymers produce a cured coating that has a lower modulus than the polycarbonate homopolymer and also prevents crystallization of the liquid coating composition. A mixture of a polycarbonate diol and a polycarbonate copolymer can also be used.

  Examples of the polycarbonate diol include Duracarb 122 (PPG Industries) and Permanol KM10-1733 (Permuthane, Mass., USA). Duracarb 122 is produced by alcoholysis of diethyl carbonate with hexanediol. Examples of polyester diols include the reaction products of saturated polycarboxylic acids or their anhydrides and diols. Examples of saturated polycarboxylic acids and anhydrides include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, tetrachlorophthalic acid, adipic acid, azelaic acid, sebacic acid, succinic acid, Examples thereof include glutaric acid, malonic acid, pimelic acid, suberic acid, 2,2-dimethylsuccinic acid, 3,3-dimethylglutaric acid, 2,2-dimethylglutaric acid and the like, and anhydrides thereof and mixtures thereof. Examples of the diol include 1,4-butanediol, 1,8-octanediol, diethylene glycol, 1,6-hexanediol, dimethylolcyclohexane, and the like. Polycaprolactones are included in this classification and are commercially available from Union Carbide under the trade names Tone Polylol, for example, Tone 0200, 0221, 0301, 0310, 2201, and 2221. Tone 0301 and 0310 are trifunctional.

  (A) As polyisocyanate (b) used for the synthesis | combination of urethane (meth) acrylate, aromatic diisocyanate, alicyclic diisocyanate, aliphatic diisocyanate, etc. are mentioned. The specific compound is not particularly limited as long as it can be used as a resin composition for optical fibers. Preferred examples include aromatic diisocyanates and alicyclic diisocyanates, more preferably 2,4-tolylene diisocyanate and isophorone. Diisocyanate is mentioned. These diisocyanate compounds may be used alone or in combination of two or more.

  Any (b) polyisocyanate can be used as the polyisocyanate alone or in a mixture.

  (A) As the polyisocyanate (b) used for the synthesis of urethane (meth) acrylate, diisocyanate is preferable. Examples of polyisocyanate (b) include isophorone diisocyanate, tetramethylxylene diisocyanate, toluene diisocyanate, diphenylmethylene diisocyanate, hexamethylene diisocyanate, cyclohexylene diisocyanate, methylenedicyclohexane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, m-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 1,5-naphthylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1, In addition to 10-decamethylene diisocyanate and 1,4-cyclohexylene diisocyanate, Compounds which at both ends diisocyanates such as toluene diisocyanate bound side or polyester glycol. These diisocyanates are preferably diisocyanates such as isophorone diisocyanate and toluene diisocyanate.

  (A) Examples of (c) hydroxy-functional ethylenically unsaturated monomers used for the synthesis of urethane (meth) acrylates include hydroxyl group-containing (meth) acrylates, hydroxyl group-containing vinyl ethers, hydroxyl group-containing maleates or hydroxyl group-containing fumarate. However, from the viewpoint of reactivity with the isocyanate group of the polyisocyanate, a hydroxyl group-containing (meth) acrylate having a hydroxyl group bonded to a primary carbon atom (referred to as a primary hydroxyl group-containing (meth) acrylate) and a hydroxyl group being secondary. A hydroxyl group-containing (meth) acrylate (referred to as a second hydroxyl group-containing (meth) acrylate) bonded to a carbon atom is preferred.

  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, Examples include dipentaerythritol penta (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, and trimethylolethane di (meth) acrylate.

  As the secondary hydroxyl group-containing (meth) acrylate, for example, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4-hydroxycyclohexyl (meta) ) Acrylates, and the like, and compounds obtained by addition reaction of glycidyl group-containing compounds such as alkyl glycidyl ether, allyl glycidyl ether, glycidyl (meth) acrylate, and (meth) acrylic acid. These hydroxy functional ethylenically unsaturated monomers can be used singly or in combination of two or more.

  (A) The proportion of (a) polyol, (b) polyisocyanate compound and (c) hydroxy-functional ethylenically unsaturated monomer used for the synthesis of urethane (meth) acrylate is 1 equivalent of hydroxyl group contained in the polyol. It is preferable that the isocyanate group contained in the polyisocyanate compound is 1.1 to 2 equivalents and the hydroxyl group of the hydroxy-functional ethylenically unsaturated monomer is 0.1 to 1 equivalents.

  It is also possible to use a diamine together with a polyol in the synthesis of (A) urethane (meth) acrylate. Examples of such diamine include ethylenediamine, tetramethylenediamine, hexamethylenediamine, paraphenylenediamine, 4,4'-diamino. Examples thereof include diamines such as diphenylmethane, diamines containing a hetero atom, and polyether diamines.

  A part of the hydroxy-functional ethylenically unsaturated monomer may be replaced with a compound having a functional group that can be added to an isocyanate group. Examples of this compound include γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and the like. By using these compounds, the adhesion to a substrate such as glass can be further enhanced.

  (A) In the synthesis of urethane (meth) acrylate, copper naphthenate, cobalt naphthenate, zinc naphthenate, dibutyltin dilaurate, triethylamine, 1,4-diazabicyclo [2.2.2] octane, 2,6,7 It is preferable to use 0.01 to 1% by weight of a urethanization catalyst such as trimethyl-1,4-diazabicyclo [2.2.2] octane based on the total amount of the reaction product. Moreover, reaction temperature is 5-90 degreeC normally, Especially 10-80 degreeC is preferable.

(A) It is preferable that the ratio of the oligomer which consists only of diisocyanate and hydroxy functional ethylenically unsaturated monomer in urethane (meth) acrylate is 10 to 50 weight%, and it is 30 to 50 weight%. Particularly preferred. When this ratio is in the range of 10 to 50% by weight, the Young's modulus of the cured product can be maintained at a moderately high level, and this is preferable in terms of high-speed curing.
A specific example of a polymer composed only of a diisocyanate and a hydroxy-functional ethylenically unsaturated monomer is obtained by reacting 2-hydroxyethyl (meth) acrylate and 2,4-tolylene diisocyanate in a molar ratio of 2: 1. A urethane (meth) acrylate etc. can be mentioned.

  (A) Urethane (meth) acrylate is a radiation curable liquid resin composition of the present invention from the viewpoint of obtaining good mechanical properties such as Young's modulus and elongation at break of the cured product and an appropriate viscosity of the radiation curable liquid resin composition. It is preferable to contain 65 to 90% by weight, particularly 70 to 90% by weight in the product. If it exceeds 90% by weight, the Young's modulus of the cured product exceeds 1200 MPa, which is not preferable as a resin for optical fiber coating, and the viscosity of the radiation-curable liquid resin composition exceeds 10.0 Pa · s. In addition, the water resistance of the cured product also deteriorates. If it is less than 65% by weight, it is difficult to obtain a Young's modulus of a cured product suitable as an optical fiber secondary layer and a tape layer. The Young's modulus of the cured product as the optical fiber secondary layer and the tape layer is preferably 50 to 1200 MPa. The viscosity of the radiation curable liquid resin composition is preferably 1.0 to 5.0 Pa · s.

Component (B) used in the present invention is a monomer represented by the formula (1). In formula (1), examples of the alkyl group represented by R ² and R ³ include a methyl group, an ethyl group, and an n-propyl group. n is preferably 1 to 4, particularly 1 to 3. Specific examples thereof include 2- (2′-vinyloxyethoxy) ethyl (meth) acrylate, 2-vinyloxyethyl (meth) acrylate, and the like. As a commercial item of a component (B), VEEA, VEEM, VEA (above, Nippon Shokubai Co., Ltd. make) etc. can be mentioned.

  A component (B) may be used individually by 1 type, and may use 2 or more types together. The content of the component (B) in the radiation curable liquid resin composition of the present invention is generally 1 to 35% by weight, preferably 5 to 35% by weight, more preferably 10 to 30%, based on the total amount of the composition. % By weight. If it is the said range, it is preferable from viewpoints, such as a viscosity of a liquid resin composition, yellowing, and a cure rate.

  The composition of this invention may contain the (C) reactive diluent as needed. (C) A reactive diluent is a vinyl monomer copolymerizable with (A) component, and is compounds other than (B) component. This reactive diluent can be used to adjust the viscosity of the coating composition. Accordingly, the reactive diluent is a low viscosity monomer having at least one functional group capable of being polymerized when exposed to actinic radiation.

  Examples of the component (C) include (C1) a polymerizable monofunctional compound or (C2) a polymerizable polyfunctional compound. Examples of such (C1) polymerizable monofunctional compounds include lactams containing vinyl groups such as N-vinylpyrrolidone and N-vinylcaprolactam, isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meta ) (Meth) acrylate having an alicyclic structure such as acrylate, dicyclopentanyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate and the like (meth) acrylate having an aromatic ring structure such as benzyl (meth) acrylate, Acryloylmorpholine, vinylimidazole, vinylpyridine, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate , Propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate , Hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate , Undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, tet Hydrofurfuryl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethylene glycol (meth) ) Acrylate, ethoxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl ( (Meth) acrylate, 7-amino-3,7-dimethyloctyl (meth) acrylate, N, N-diethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, hydroxybutyl vinyl ether, lauryl vinyl ether, cetyl vinyl ether And 2-ethylhexyl vinyl ether.

  Of these (C1) polymerizable monofunctional compounds, monofunctional (meth) acrylates having an aliphatic hydrocarbon group having 10 or more carbon atoms are preferred from the viewpoint of dilutability. Here, as an aliphatic group having 10 or more carbon atoms, any of straight chain, branched chain and alicyclic is included, and the number of carbon atoms is preferably 10 to 24. Of these, isobornyl (meth) acrylate, isodecyl (meth) acrylate, and lauryl (meth) acrylate are more preferable. Commercially available products of these (C1) polymerizable monofunctional compounds include IBXA (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Aronix M-110, M-111, M-113, M114, M-117, TO-1210 ( As described above, Toagosei Co., Ltd. can be used.

Further, from the viewpoint of curability, (C1) the polymerizable monofunctional compound is preferably a monomer or monomers having acrylate functionality or vinyl ether functionality and a C 4-20 alkyl group or polyether moiety. Examples of such reactive diluents are hexyl acrylate, 2-ethylhexyl acrylate, isobornyl acrylate, decyl acrylate, lauryl acrylate, stearyl acrylate, ethoxyethoxy-ethyl acrylate, lauryl vinyl ether, 2-ethylhexyl vinyl ether, N-vinyl. Formamide, isodecyl acrylate, isooctyl acrylate, vinyl-caprolactam, N-vinyl pyrrolidone and the like.
Furthermore, the reactive diluent in another preferred embodiment from the viewpoint of elastic modulus is a compound containing an aromatic group. Examples of diluents having aromatic groups include ethylene glycol phenyl ether acrylate, polyethylene glycol phenyl ether acrylate, polypropylene glycol phenyl ether acrylate, and alkyl-substituted phenyl derivatives of the above monomers, such as polyethylene glycol nonyl phenyl ether acrylate.

  On the other hand, although a vinyl group-containing lactam such as N-vinylpyrrolidone and N-vinylcaprolactam can contribute to an increase in the curing rate, it has a drawback of causing yellowing in the cured product. When it is not contained or used, it is preferably less than 10% by weight.

  Examples of the polymerizable polyfunctional compound (C2) include trimethylolpropane tri (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, trimethylolpropane trioxyethyl (meth) acrylate, Tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate , Di (meth) acrylate of bisphenol A ethylene oxide or propylene oxide adduct diol, di (meth) acrylate of hydrogenated bisphenol A ethylene oxide or propylene oxide adduct diol, (meth) acrylate to diglycidyl ether of bisphenol A And epoxy (meth) acrylate to which is added, triethylene glycol divinyl ether, and the like.

  Moreover, as a commercial item, for example, light acrylate 9EG-A and light acrylate 4EG-A (manufactured by Kyoeisha Chemical Co., Ltd.), Iupimer UV SA1002, SA2007 (above, manufactured by Mitsubishi Chemical Corporation); Biscote 700 (Osaka) KAYARAD R-604, DPCA-20, -30, -60, -120, HX-620, D-310, D-330 (above, Nippon Kayaku Co., Ltd.); Aronix M-210, M-215, M-315, M-325 (above, Toagosei Co., Ltd. product) etc. are mentioned.

  (C2) The polymerizable polyfunctional compound includes a hydrocarbon diol diacrylate having 2 to 18 carbon atoms, a hydrocarbon divinyl ether having 4 to 18 carbon atoms, a hydrocarbon triol triacrylate having 3 to 18 carbon atoms, and a polyether thereof. Of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, hexanediol divinyl ether, triethylene glycol diacrylate, pentaerythritol triacrylate and tripropylene glycol diacrylate. More preferred is an alkoxylated alkylphenol (meth) acrylate, and the most preferred reactive diluent is ethoxylated nonylphenol (meth) acrylate. Each of the oligomer and the reactive diluent preferably contains an acrylate group as a radiation curable group.

  These (C1) polymerizable monofunctional compound and (C2) polymerizable polyfunctional compound may be used alone or in combination.

  These components (C) are preferably contained in the radiation-curable liquid resin composition of the present invention in an amount of 1 to 33% by weight, more preferably 2 to 30% by weight. If it is less than 1% by weight, the curability may be impaired. If it exceeds 33% by weight, the coating shape changes due to low viscosity, and the coating is not stable.

  The radiation-curable liquid resin composition of the present invention is cured by radiation. Here, the radiation refers to infrared rays, visible rays, ultraviolet rays, X-rays, α rays, β rays, γ rays, electron beams, and the like, and ultraviolet rays and electron beams are particularly preferable.

  The irradiation source in the case of using ultraviolet rays may be a normal light source such as a UV lamp commercially available from Fusion System Corp., for example. In addition, low pressure, medium pressure, and high pressure mercury lamps, super actinic fluorescent tubes, or pulse lamps are suitable.

  When the radiation curable liquid resin composition of the present invention is cured by ultraviolet rays, (D) a polymerization initiator can be added as necessary. As the component (D), a (D1) photopolymerization initiator is usually used, but a (D2) thermal polymerization initiator may be used in combination with the (D1) photopolymerization initiator as necessary.

  (D1) Examples of the photopolymerization initiator include benzophenone and acetophenone derivatives such as α-hydroxyalkylphenyl ketone, benzoin alkyl ether and benzyl ketal; or acylphosphine oxide; other bisacylphosphine oxides; or titanocene.

  Specific examples of the (D1) photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3- Methyl acetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's 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-trimethylpentylphosphine oxide and the like. The commercially available products include Irgacure 184, 369, 651, 500, 907, 819, CGI 1700, CGI 1750, CGI 1850, CGI 1870, CG 2461, Darocur 1116, 1173 (above, manufactured by Ciba Specialty Chemicals); LUCIRIN TPO (BASF) Manufactured by Ubekrill P36 (manufactured by UCB).

  (D2) Examples of the thermal polymerization initiator include peroxides and azo compounds, and specific examples include benzoyl peroxide, t-butyl-oxybenzoate, and azobisisobutyronitrile.

  (D) The polymerization initiator is preferably blended in the radiation curable liquid resin composition of the present invention in an amount of 0.1 to 10% by weight, particularly 0.5 to 5% by weight.

  A photosensitizer, a light stabilizer and the like can be further added to the radiation curable liquid resin composition of the present invention. Examples of photosensitizers include secondary and / or tertiary amines such as ethanolamine, methyldiethanolamine, dimethylethanolamine, triethylamine, triethanolamine, ethyl p-dimethylaminobenzoate, methyl p-dimethylaminobenzoate. , Ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, benzyldimethylamine, dimethylaminoethyl acrylate, N-phenylglycine, N-methyl-N-phenylglycine and the like. Aliphatic and aromatic halides such as 2-chloromethyl-naphthalene, 1-chloro-2-chloromethyl-naphthalene, and compounds that form free radicals such as peroxides and azo compounds are also used to promote curing can do. Examples of commercially available photosensitizers include Ubekryl P102, 103, 104, and 105 (above, manufactured by UCB).

  As the light stabilizer, a small amount of a UV absorber, typically a benzotriazole-based, benzophenone-based, or oxaanilide-based UV absorber can be added. Sterically hindered amine light stabilizers (HALS) can also be added. Specific examples of the light stabilizer include Tinuvin 292, 144, 622LD (manufactured by Ciba Specialty Chemicals Co., Ltd.), Sanol LS770 (manufactured by Sankyo Corporation), TM-061 (manufactured by Sumitomo Chemical Co., Ltd.), etc. Is mentioned. Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and commercially available products such as SH6062, 6030 (above, Toray Dow Corning Silicone Co., Ltd.). Product), KBE903, 603, 403 (manufactured by Shin-Etsu Chemical Co., Ltd.).

  Examples of other additives include thermal inhibitors that prevent premature polymerization, particularly during mixing of the ingredients to prepare the composition, such as hydroquinone, hydroquinone derivatives, p-methoxyphenol, β- Examples include naphthol and sterically hindered phenols such as 1,6-di (tert-butyl) -p-cresol.

  When used for coating an optical fiber ribbon, a release agent may be included to facilitate peeling of the coating layer. As the release agent, silicone, fluorocarbon oil, resin or the like is suitable. When these release agents are used, it is preferable to contain 0.5 to 20% by weight of an appropriate release agent.

  In addition to the above components, the radiation curable liquid resin composition of the present invention includes various additives such as colorants, silane coupling agents, leveling agents, surfactants, storage stabilizers, plasticizers, lubricants, solvents, fillers. An anti-aging agent, a wettability improving agent, a coating surface improving agent and the like can be blended as necessary.

  The viscosity of the radiation curable liquid resin composition of the present invention is preferably 1.0 to 5.0 Pa · s, particularly 3.0 to 5.0 Pa · s at 25 ° C. from the viewpoint of usability. Moreover, it is preferable that a cure rate is 0.6-0.9, especially 0.7-0.9.

  The Young's modulus of the cured product obtained using the resin composition of the present invention is preferably 50 to 1200 MPa, particularly 500 to 1200 MPa.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, unless otherwise indicated, a part means a weight part.

Synthesis example 1 of urethane acrylate
A reaction vessel equipped with a stirrer was charged with 134.8 g of 2,4-toluene diisocyanate, 774.2 g of polypropylene oxide having a molecular weight of 2000, 0.24 g of 2,6-di-t-butyl-p-cresol, and 0.08 g of phenothiazine. It is. Next, 0.8 g of dibutyltin diurarate was added, and the mixture was stirred for 1 hour while controlling the liquid temperature at 25 to 35 ° C. Thereafter, 89.9 g of hydroxyethyl acrylate was added, and stirring was continued for 1 hour at a liquid temperature of 50 to 60 ° C., and the reaction was terminated when the residual isocyanate was 0.1 wt% or less to obtain urethane acrylate. This urethane acrylate is referred to as “UA-1”.

Synthesis example 2 of urethane acrylate
A reaction vessel equipped with a stirrer was charged with 413.8 g of 2,4-toluene diisocyanate, 0.24 g of 2,6-di-t-butyl-p-cresol, 0.08 g of phenothiazine, and 0.8 g of dibutyltin diurarate. Next, 309.2 g of hydroxypropyl acrylate was added, and the mixture was stirred for 1 hour while controlling the liquid temperature at 25 to 35 ° C. Thereafter, 275.9 g of hydroxyethyl acrylate was added, stirring was continued for 1 hour at a liquid temperature of 50 to 60 ° C., and the reaction was terminated when the residual isocyanate was 0.1 wt% or less to obtain urethane acrylate. This urethane acrylate is referred to as “UA-2”.

Synthesis example 3 of urethane acrylate
A reaction vessel equipped with a stirrer was charged with 428.1 g of 2,4-toluene diisocyanate, 0.24 g of 2,6-di-t-butyl-p-cresol, 0.08 g of phenothiazine, and 0.8 g of dibutyltin diurarate. Thereafter, 570.8 g of hydroxyethyl acrylate was added, stirring was continued for 1 hour at a liquid temperature of 50 to 60 ° C., and the reaction was terminated when the residual isocyanate was 0.1% by weight or less to obtain urethane acrylate. This urethane acrylate is referred to as “UA-3”.

Examples 1-4 and Comparative Examples 1-4
A compound was charged into a reaction vessel equipped with a stirrer at a blending ratio (parts by weight) shown in Table 1, and stirred at a liquid temperature of 50 ° C. until a uniform solution was obtained, thereby obtaining each composition.

Measuring method:
(1) Curing speed: The composition was applied on a quartz glass plate using an applicator having a thickness of 200 μm, and ultraviolet irradiation doses of 0.1 J / cm ² and 1.0 J in an air atmosphere using a 3.5 KW metal halide lamp. A cured film was obtained by irradiating ultraviolet rays under two conditions of / cm ² . Next, the sample was allowed to stand at 23 ° C. and a relative humidity of 50% for 24 hours, and then cut to 1 cm width to obtain a test piece. Next, the Young's modulus (MPa) of the test piece was measured with a tensile tester. The value obtained by dividing the obtained Young's modulus by the amount of UV irradiation was taken as the curing rate.

(2) Viscosity: The composition was allowed to stand in a constant temperature water bath at 25 ° C for 30 minutes, and then the viscosity was measured using a B-type viscometer.

(3) Yellowness: obtained by applying the composition onto clean glass using an applicator having a thickness of 200 μm and irradiating with ultraviolet rays of 0.1 J / cm ² using a 3.5 kW metal halide lamp in an N ₂ atmosphere. A cured film was used as a test piece. Subsequently, it is left to stand at 23 ° C. and a relative humidity of 50% for 24 hours. I. Was measured using a color difference meter.

(4) Surface property: A film formed with a sticking force of 70 μm thick was irradiated with ultraviolet rays in an air environment at 0.1 J / cm ² using a 3.5 KW metal halide lamp to obtain a cured film. The cured film was bonded and allowed to stand for 24 hours under a constant load, and then measured by a 180 degree peel method using an Instron digital tester (manufactured by Instron Japan Co., Ltd.). The dynamic friction coefficient was measured by irradiating a film formed at a thickness of 200 μm with ultraviolet rays in an air atmosphere at 0.1 J / cm ² using a 3.5 KW metal halide lamp to obtain a cured film. The film was divided into two cylinders, and the coefficient of resistance when slid by applying a load of 100 g was measured with a surface characteristic measuring machine (manufactured by Shinto Kagaku Co., Ltd.) to determine the dynamic friction coefficient.

  Each evaluation was performed about the composition obtained in the Example. The results are shown in Table 1.

2-vinyloxyethyl acrylate; Nippon Shokubai Co., Ltd. VEA
2- (2'-vinyloxyethoxy) ethyl acrylate; Nippon Shokubai Co., Ltd. VEEA
2- (2'-vinyloxyethoxy) ethyl methacrylate; Nippon Shokubai Co., Ltd. VEEM
Irgacure 184; Ciba Specialty Chemicals Co., Ltd. 1-hydroxy-cyclohexyl-phenyl ketone

  From Table 1, the resin composition containing 65 to 90% by weight of component (A) and 1 to 35% by weight of component (B) has low viscosity and good usability, and the cured product of the composition is Young. It can be seen that the rate is 50 to 1200 MPa, the curing rate is high, the yellowing degree is low, and the surface properties are good.

Claims (4)

The following components (A) and (B):
(A) urethane (meth) acrylate 65 to 90% by weight,
(B) 1 to 35% by weight of a monomer represented by the following formula (1),

[In Formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴ represents a hydrogen atom or a methyl group. N represents a number from 1 to 6. ]
A radiation-curable liquid resin composition containing   The radiation curable liquid resin composition according to claim 1, wherein 10 to 50% by weight of the (A) urethane (meth) acrylate is an oligomer composed only of diisocyanate and a hydroxy functional ethylenically unsaturated monomer.   The radiation curable liquid resin composition according to claim 1, wherein the viscosity at 25 ° C. is 1.0 to 5.0 Pa · s.   The radiation-curable liquid resin composition according to any one of claims 1 to 3, which is used for coating an optical fiber.