JP2010235812A - Liquid curable resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid curable resin composition having good stability and viscosity characteristics of a resin liquid and good water resistance of a cured product, and being useful as a primary material of an optical fiber in particular. <P>SOLUTION: The liquid curable resin composition for a primary material of an optical fiber contains: (A1) a urethane (meth)acrylate having two or more structural units derived from aliphatic polyether polyols having a number-average molecular weight of 1,000 to 4,000, and two ethylenically unsaturated groups; (A2) a urethane (meth)acrylate having two or more structural units derived from aliphatic polyether polyols having a number-average molecular weight of 1,000 to 4,000, one ethylenically unsaturated group, and a structural unit derived from 1-3C monoalcohol; (B) an alkyl (meth)acrylate expressed by formula (1): CH<SB>2</SB>=C(R<SP>1</SP>)COO-(CH<SB>2</SB>)<SB>n</SB>-CH(CH<SB>3</SB>)<SB>2</SB>(wherein R<SP>1</SP>represents a hydrogen atom or a methyl group and n represents an integer of 4 to 8); and (C) a polymerization initiator. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid curable resin composition having characteristics suitable as an optical fiber coating material, particularly as a primary material for optical fibers.

  An optical fiber is manufactured by coating a glass fiber obtained by hot-melt spinning of glass with a resin for the purpose of protection and reinforcement. As this resin coating, a flexible primary coating layer (hereinafter also referred to as “primary coating layer”) is first provided on the surface of the optical fiber, and a highly rigid secondary coating layer (hereinafter also referred to as “primary coating layer”) is provided. Hereinafter, a structure provided with “secondary coating layer” is also known. Tape-like optical fibers and optical fiber cables in which a plurality of optical fiber strands coated with these resins are hardened with a binding material are also well known. A resin composition for forming a primary coating layer of an optical fiber strand is a primary material, a resin composition for forming a secondary coating layer is a secondary material, and a binding material for a plurality of optical fiber strands The resin composition used as is called a bundling material. In some cases, a plurality of tape-like optical fibers and optical fiber cables may be further combined with a binding material, and the binding material used at this time is also called a bundling material. As these resin coating methods, a method in which a liquid curable resin composition is applied and cured by heat or light, particularly ultraviolet rays, is widely used.

  Of these coating materials, the primary material needs to have a hardened product. Furthermore, since the primary material is the primary coating on the glass fiber, in addition to the stability of the resin liquid and the water resistance of the cured product, it is particularly stable due to the need for excellent high-speed coating properties. Viscosity characteristics are required. The liquid curable resin composition useful for such a primary material contains a composition having an aliphatic urethane oligomer having low swellability in gasoline (Patent Document 1), an aliphatic urethane oligomer and a hydrocarbon monomer. A composition (Patent Document 2), a composition containing a specific silane coupling agent (Patent Document 3), and the like are known. Moreover, the liquid curable resin composition for primary materials of the optical fiber which was excellent in the high-speed coating property by employ | adopting the acrylate monomer which has a linear alkyl group is also known (patent document 4).

JP-A-5-306146 JP-A-5-306147 JP 2001-130929 A JP 2005-263946 A

However, in the case of a primary material that employs an acrylate monomer having a linear alkyl group, the crystallinity in the composition is high due to the structural reason of the monomer, particularly when the composition is placed in a low temperature environment. In some cases, the storage stability of the resin liquid is lowered.
Accordingly, an object of the present invention is to provide a liquid curable resin composition having good storage stability of a resin liquid, particularly storage stability in a low temperature environment, and having a hardness (Young's modulus) suitable as a primary material. There is.

  As a result of various studies to obtain a composition having the above characteristics, the present inventors solved these problems by combining a mixture of urethane (meth) acrylates having a specific structure and an acrylate monomer having a specific branched structure. The present invention has been completed by finding out what can be done.

That is, the present invention includes the following components (A1), (A2), (B) and (C):
(A1) urethane (meth) acrylate having two or more structural units derived from an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000 and two ethylenically unsaturated groups,
(A2) Two or more structural units derived from an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000, one ethylenically unsaturated group and a structure derived from a monoalcohol having 1 to 3 carbon atoms Urethane (meth) acrylate having units,
(B) an alkyl (meth) acrylate represented by the following formula (1),
^{_{CH 2 = C (R 1)}} COO- (CH 2) n -CH (CH 3) 2 (1)
(R ¹ represents a hydrogen atom or a methyl group, and n represents an integer of 4 to 8)
(C) A liquid curable resin composition for a primary material of an optical fiber containing a polymerization initiator is provided.

  The liquid curable resin composition of the present invention has good storage stability, particularly when the composition is placed in a low-temperature environment, the storage stability of the resin liquid is good, and the composition has a viscosity suitable for high-speed coating properties. ing. Moreover, it has hardness (Young's modulus) suitable as a primary material. Therefore, the composition of the present invention is useful as an optical fiber coating material, particularly as a primary material.

[Liquid resin composition]
The urethane (meth) acrylate which is a polymerizable oligomer of the component (A) used in the liquid curable resin composition of the present invention is a mixture containing the following components (A1) and (A2), and further a component (A3) Can also be contained. Since the liquid curable resin composition of the present invention has the component (A) having the following contents, the crosslink density in the case of being a cured product is controlled, and an optical fiber having a Young's modulus suitable as a primary material The primary coating layer can be obtained.
(A1) urethane (meth) acrylate having two or more structural units derived from an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000 and two ethylenically unsaturated groups,
(A2) Two or more structural units derived from an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000, one ethylenically unsaturated group and a structure derived from a monoalcohol having 1 to 3 carbon atoms Urethane (meth) acrylate having units,
(A3) Two or more structural units derived from an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000, one structural unit derived from ethylenically unsaturated groups and a structural unit derived from γ-mercaptopropyltrimethoxysilane Urethane (meth) acrylate having

The urethane (meth) acrylate of component (A1) is obtained by reacting an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000, a polyisocyanate, and a hydroxyl group-containing (meth) acrylate. ).
HI- (POL-I) _n- IH (2)
[In the above formula, H is a hydroxyl group-containing (meth) acrylate, I is a polyisocyanate, and POL is an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000. n is 2-4. ]

  The number average molecular weight of the aliphatic polyether polyol used for the component (A1) is preferably 1,500 to 3,000, more preferably 15,00 to 2,500. In general, since aliphatic polyether polyol has a flexible structure, the Young's modulus of the cured product decreases as the molecular weight increases, and the Young's modulus of the cured product increases as the molecular weight decreases. Therefore, the Young's modulus suitable as a primary material can be obtained by setting it as the said molecular weight range. Here, the molecular weight of the aliphatic polyether polyol is a polystyrene-equivalent number average molecular weight measured by a gel permeation chromatography method.

Component (A2) urethane (meth) acrylate is a reaction of an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000, a polyisocyanate, a hydroxyl group-containing (meth) acrylate, and a monoalcohol having 1 to 3 carbon atoms. And has a structure represented by the following formula (3).
HI- (POL-I) _n- I-AL (3)
[In the above formula, H, I, POL and n are the same as those in the formula (2). AL represents a structure derived from a monoalcohol having 1 to 3 carbon atoms. ]

The number average molecular weight of the aliphatic polyether polyol used for the component (A2) is the same as in the case of the component (A1).
The component (A2), unlike the component (A1), has only one ethylenically unsaturated group and cannot contribute to the crosslinking reaction with a plurality of ethylenically unsaturated groups. For this reason, by using the component (A2) in addition to the component (A1), it becomes possible to adjust the Young's modulus of the cured product to a range suitable for the primary material.

The component (A3) urethane (meth) acrylate is obtained by reacting an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000, a polyisocyanate, a hydroxyl group-containing (meth) acrylate, and γ-mercaptopropyltrimethoxysilane. And has a structure represented by the following formula (4).
HI- (POL-I) _n- I-SL (4)
[In the above formula, H, I, POL and n are the same as those in the formula (2). SL indicates a structure derived from γ-mercaptopropyltrimethoxysilane. ]

The number average molecular weight of the aliphatic polyether polyol used for the component (A3) is the same as in the case of the component (A1).
Since the component (A3) has only one ethylenically unsaturated group, like the component (A2), it cannot contribute to the crosslinking reaction with a plurality of ethylenically unsaturated groups. For this reason, by using the component (A3) in addition to the components (A1) and (A2), it becomes possible to adjust the Young's modulus of the cured product to a range suitable as a primary material.
Furthermore, since the component (A3) has a structure derived from γ-mercaptopropyltrimethoxysilane, the adhesion between the primary coating layer and the glass fiber can be improved, and a high-strength primary coating layer can be formed. .

  Examples of the polyisocyanate used in the synthesis of the urethane (meth) acrylate (A1), (A2), and (A3), preferably a diisocyanate compound 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-naphthalene diisocyanate, and m-phenylene diisocyanate. P-phenylene diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 3,3′-dimethylphenylene diisocyanate, 4,4′-biphenylene diisocyanate, bis (2- Isocyanate) fumarate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate, tetramethylxylylene diisocyanate and the like. Examples of the alicyclic diisocyanate include isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, and 2,5-bis (isocyanate methyl) -bicyclo [2.2.1] heptane. 2,6-bis (isocyanatomethyl) -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 diisocyanate is more preferable, and 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate are particularly preferable from the viewpoint of obtaining an economical and stable quality composition. These diisocyanates may be used alone or in combination of two or more.

  Examples of the aliphatic polyether polyol used in the production of the urethane (meth) acrylate (A1), (A2), and (A3) include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, and polyheptamethylene glycol. And polyether diol obtained by ring-opening copolymerization of polydecamethylene glycol and two or more ion-polymerizable cyclic compounds.

  Examples of the ion polymerizable cyclic compound include ethylene oxide, propylene oxide, butene-1-oxide, isobutene oxide, 3,3-bischloromethyloxetane, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, dioxane, trioxane, and 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 glycidyl ether, glycidyl benzoate And cyclic ethers.

  Specific examples of polyether diols obtained by ring-opening copolymerization of two or more of the above ion-polymerizable cyclic compounds include, for example, tetrahydrofuran and propylene oxide, tetrahydrofuran and 2-methyltetrahydrofuran, tetrahydrofuran and 3-methyltetrahydrofuran, tetrahydrofuran and the like. Binary copolymers obtained from combinations of ethylene oxide, propylene oxide and ethylene oxide, butene-1-oxide and ethylene oxide; terpolymers obtained from combinations of tetrahydrofuran, butene-1-oxide and ethylene oxide .

  Further, a polyether diol obtained by ring-opening copolymerization of the ion polymerizable cyclic compound and a cyclic imine such as ethyleneimine; a cyclic lactone acid such as β-propiolactone or glycolic acid lactide; or a dimethylcyclopolysiloxane. Can also be used.

  The aliphatic polyether diol is, for example, PTMG650, PTMG1000, PTMG2000 (manufactured by Mitsubishi Chemical Corporation), PPG400, PPG1000, EXCENOL720, 1020, 2020 (manufactured by Asahi Olin), PEG1000, Unisafe DC1100, DC1800 (or more, (Nippon Yushi Co., Ltd.), PPTG2000, PPTG1000, PTG400, PTGL2000 (above, manufactured by Hodogaya Chemical Co., Ltd.), Z-3001-4, Z-3001-5, PBG2000A, PBG2000B, EO / BO4000, EO / BO2000 (above, Daiichi Kogyo Seiyaku Co., Ltd.), Acclaim 2200, 2220, 3201, 3205, 4200, 4220, 8200, 12000 (above, manufactured by Sumitomo Bayer Urethane Co., Ltd.) It can be obtained.

  Among these aliphatic polyether polyols, it is a ring-opening polymer of one or more kinds of ion-polymerizable cyclic compounds having 2 to 4 carbon atoms, and a diol having an average molecular weight of 1000 to 5000 is used as a resin. This is preferable from the viewpoint of both high-speed application of the liquid and flexibility of the coating material. As such a preferred diol compound, a ring-opening polymer of one or more oxides selected from ethylene oxide, propylene oxide, butene-1-oxide and isobutene oxide, having an average molecular weight of 1000 to 4000. Can be mentioned. In particular, a ring-opening polymer of propylene oxide having an average molecular weight of 1000 to 3000 is preferable.

  As the hydroxyl group-containing (meth) acrylate compound used in the synthesis of urethane (meth) acrylate (A1), (A2), (A3), a hydroxyl group-containing (meth) acrylate having a hydroxyl group bonded to a primary carbon atom (first) It is preferable to use a hydroxyl group-containing (meth) acrylate) and a hydroxyl group-containing (meth) acrylate having a hydroxyl group bonded to a secondary carbon atom (referred to as a secondary hydroxyl group-containing (meth) acrylate). A hydroxyl group-containing (meth) acrylate having a hydroxyl group bonded to a tertiary carbon atom (referred to as a tertiary hydroxyl group-containing (meth) acrylate) is not preferred because it has poor reactivity with an isocyanate group.

  Examples of the primary hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 1,6-hexanediol mono (meth) acrylate. , Pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethane di (meth) acrylate, and the like.

  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 ethers, allyl glycidyl ethers and glycidyl (meth) acrylates with (meth) acrylic acid.

  In the synthesis of urethane (meth) acrylate (A), copper naphthenate, cobalt naphthenate, zinc naphthenate, dibutyltin dilaurate, dioctyltin dilaurate, triethylamine, 1,4-diazabicyclo [2.2.2] octane, 2, It is preferable to use 0.01 to 1% by mass of a urethanization catalyst selected from 6,7-trimethyl-1,4-diazabicyclo [2.2.2] octane and the like based on the total amount of the reactants. The reaction temperature is usually 5 to 90 ° C, particularly 10 to 80 ° C.

  The urethane (meth) acrylate (A) may be blended in an amount of 30 to 90% by mass, further 35 to 85% by mass, particularly 45 to 75% by mass with respect to 100% by mass of the total amount of the liquid curable resin composition of the present invention. preferable. If it is less than 45% by mass, the temperature dependence of the elastic modulus is large, and if it is 90% by mass or more, the viscosity of the liquid curable resin composition may be high.

  Urethane (meth) acrylate (A1), (A2), and (A3) are 40 to 80% by mass of component (A1) and 20 to 20% of component (A2) with respect to 100% by mass of the total amount of component (A), respectively. It is preferable that 40 mass% and a component (A3) are 0-20 mass%, a component (A1) is 50-70 mass%, a component (A2) is 25-35 mass%, and a component (A3) is 5-15. More preferably, it is mass%.

Component (B) used in the composition of the present invention is an alkyl (meth) acrylate represented by the following formula (1).
^{_{CH 2 = C (R 1)}} COO- (CH 2) n -CH (CH 3) 2 (1)
(R ¹ represents a hydrogen atom or a methyl group, and n represents an integer of 4 to 8)
Component (B) has a branched structure in which the hydrocarbon group bonded to the (meth) acryloyl group has a tendency to be less crystallized in the composition than a (meth) acrylate monomer that does not have a branched structure. For this reason, it has the effect of improving the storage stability of the composition, particularly the storage stability under low temperature conditions.

  Specific examples of the component (B) include isohexyl (meth) acrylate, isoheptyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, and the like. Of these, isononyl (meth) acrylate is particularly preferred from the viewpoint of industrial applicability.

  The component (B) (meth) acrylate compound is preferably blended in an amount of 8 to 60% by mass, particularly 10 to 30% by mass, based on 100% by mass of the total amount of the liquid curable resin composition of the present invention. If the amount is less than 8% by mass, the viscosity increases, and the effect of improving the mechanical properties of the cured product is small. If the amount exceeds 60% by mass, the volatility increases, which is not preferable. Further, the component (B) is contained in an amount of 50% by mass or more based on 100% by mass of the total amount of the compound having one ethylenically unsaturated group (excluding urethane (meth) acrylate) contained in the composition. It is preferable that 60 to 80% by mass is contained.

  As the polymerization initiator (C) used in the liquid curable resin composition of the present invention, a thermal polymerization initiator or a photopolymerization initiator can be used.

  When the resin composition of the present invention is thermally cured, a thermal polymerization initiator such as a peroxide or an azo compound can usually be used. Specific examples include benzoyl peroxide, t-butyl-oxybenzoate, azobisisobutyronitrile, and the like.

  Moreover, when photocuring the resin composition of this invention, a photoinitiator can be used and a photosensitizer can be further added as needed. Here, as the photopolymerization initiator, for example, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl 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; IRGACURE184, 369, 651, 500, 907, CGI1700, CGI1750, CGI1850, CG24-61, DAROCUR1116, 1173 (above, manufactured by Ciba Specialty Chemicals); LUCIRIN TPO (Made by BASF); Ubekrill P36 (made by UCB) etc. are mentioned. Examples of the photosensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, 4-dimethylaminobenzoate. Isoamyl acid; Ubekryl P102, 103, 104, 105 (above, manufactured by UCB) and the like.

  The polymerization initiator (C) is preferably blended in an amount of 0.1 to 10% by mass, particularly 0.3 to 7% by mass with respect to 100% by mass of the total amount of the liquid curable resin composition of the present invention.

  A silane coupling agent (D) can also be mix | blended with the liquid curable resin composition of this invention within the range which does not inhibit the effect of invention. The component (D) is not particularly limited, and vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxy-ethoxy) silane, β- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, γ-glycol. Sidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-amino Ethyl) -γ-aminopropyltrimethoxydimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, etc. are used. be able to. Further, bis- [3- (triethoxysilyl) propyl] tetrasulfide, bis- [3- (triethoxysilyl) propyl] disulfide, γ-trimethoxysilylpropyldimethylthiocarbamyl tetrasulfide, γ-trimethoxysilylpropyl Benzothiazyl tetrasulfide and the like can also be used. Examples of the commercially available products include SH6062, SZ6030 (manufactured by Toray Dow Corning Silicone), KBE903, 603, 403 (manufactured by Shin-Etsu Chemical Co., Ltd.). These silane coupling agents are selected from the viewpoint of adhesion between the coating and glass, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyl. Trimethoxysilane is preferred. These silane coupling agents may be used alone or in combination of two or more.

  A silane coupling agent (D) is 0.01-2 mass% from the point of maintenance of the adhesive force of a coating | cover and glass with respect to 100 mass% of liquid curable resin composition whole quantity of this invention, Furthermore, 0.1 It is preferable to add to 1.5% by mass, particularly 0.5 to 1.5% by mass.

In the composition of the present invention, other than the components (A) and (B), a compound having one ethylenically unsaturated group (component (E)) or a compound having two or more ethylenically unsaturated groups (component ( F)) can be blended.
Specific examples of such component (E) include, for example, vinyl group-containing lactams such as N-vinylpyrrolidone and N-vinylcaprolactam, isobornyl (meth) acrylate, bornyl (meth) acrylate, and tricyclodecanyl (meth) acrylate. , Alicyclic structure-containing (meth) acrylates such as dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, Examples include acryloyl morpholine, vinyl imidazole, and vinyl pyridine. Furthermore, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, tetrahydrofurfuryl (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) a Rilamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 7-amino-3,7-dimethyloctyl (meth) acrylate, N, N-diethyl (meth) acrylamide, N, N-dimethylaminopropyl ( Mention may be made of (meth) acrylamide, hydroxybutyl vinyl ether, lauryl vinyl ether, cetyl vinyl ether, 2-ethylhexyl vinyl ether, vinyloxyethoxyethyl (meth) acrylate and vinyloxyethyl (meth) acrylate. Among these (E) components, vinyl group-containing lactams such as N-vinylpyrrolidone and N-vinylcaprolactam are preferable from the viewpoint of improving the curing rate.

  Moreover, as a commercial item of the monofunctional compound of said polymerizable unsaturated monomer, Aronix M-111, M-113, M-114, M-117 (above, Toagosei Co., Ltd. make); KAYARAD, TC110S, R629, R644 (Nippon Kayaku Co., Ltd.); IBXA, Biscoat 3700 (Osaka Organic Chemical Co., Ltd.) and the like.

  Component (E) is preferably blended in an amount of 0.1 to 20% by mass, particularly 5 to 15% by mass, based on 100% by mass of the total amount of the liquid curable resin composition of the present invention.

  Examples of the component (F) 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, bisphenol Di (meth) acrylate of diol of adduct of ethylene oxide or propylene oxide of A, di (meth) acrylate of diol of ethylene oxide or propylene oxide of hydrogenated bisphenol A, diglycidyl ether of bisphenol A (meta ) Epoxy (meth) acrylate added with acrylate, triethylene glycol divinyl ether, and the like. Commercially available products include, for example, Iupimer UV SA1002, SA2007 (manufactured by Mitsubishi Chemical Corporation); Biscoat 700 (manufactured by Osaka Organic Chemical Industry Co., Ltd.); 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.) .

  Since the component (F) has an effect of increasing the crosslink density in the cured product, if it is excessively blended, the Young's modulus of the cured product may become excessive and may be unsuitable as a primary material. For this reason, it is preferable that the compounding quantity of a component (F) shall be 5 mass% or less with respect to 100 mass% of liquid curable resin composition whole quantity of this invention, especially 3 mass% or less.

In addition to the above components, various additives such as antioxidants, colorants, ultraviolet absorbers, light stabilizers, thermal polymerization inhibitors, 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.
Here, examples of the antioxidant include IRGANOX 1010, 1035, 1076, 1222 (manufactured by Ciba Specialty Chemicals), ANTIGENE P, 3C, Sumilizer GA-80, GP (manufactured by Sumitomo Chemical Co., Ltd.), and the like. Examples of the ultraviolet absorber include TINUVIN P, 234, 320, 326, 327, 328, 329, 213 (above, manufactured by Ciba Specialty Chemicals), Seesorb 102, 103, 501, 202, 712, 704 (above, Sipro Chemical Co., Ltd.). Manufactured) and the like. Examples of the light stabilizer include TINUVIN 292, 144, and 622LD (manufactured by Ciba Specialty Chemicals), Sanol LS770 (manufactured by Sankyo Company), TM-061 (manufactured by Sumitomo Chemical Co., Ltd.), and the like.

  If necessary, the composition of the present invention can be blended with other oligomers, polymers, other additives and the like as long as the characteristics of the liquid curable resin composition of the present invention are not impaired.

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

  The liquid curable resin composition of the present invention is cured by heat and / or radiation. Here, radiation refers to infrared rays, visible rays, ultraviolet rays, X rays, electron beams, α rays, β rays, γ. For example, ultraviolet rays are preferable.

  The viscosity of the liquid curable resin composition of the present invention is preferably 0.1 to 10 Pa · s, and more preferably 1 to 8 Pa · s at 25 ° C. from the viewpoints of handling properties and coatability.

  The cured product of the composition of the present invention has a relatively low Young's modulus and excellent water resistance, and thus is useful as a primary material for optical fibers. Here, the Young's modulus of the cured product is preferably 0.1 to 10 MPa at 25 ° C., and more preferably 0.5 to 5 MPa. Further, the Young's modulus at −40 ° C. is preferably 30 to 500 MPa, and more preferably 50 to 300 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 compounding quantity is a mass part.

Synthesis Example 1 Synthesis of urethane (meth) acrylate (UA-1):
In a reaction vessel equipped with a stirrer, 86.16 parts of polypropylene glycol having a number average molecular weight of 2000, 10.17 parts of 2,4-tolylene diisocyanate, 0.024 of 2,6-di-t-butyl-p-cresol The temperature of the solution was adjusted to 25 ° C. while stirring them. After adding 0.80 part of dibutyltin dilaurate, the liquid temperature was gradually raised to 45 ° C. over 1 hour with stirring. Thereafter, the liquid temperature was raised to 50 ° C. for reaction. After the residual isocyanate group concentration became 1.34% by mass (ratio to the charged amount) or less, 3.57 parts of 2-hydroxyethyl acrylate was added and stirred at a liquid temperature of about 60 ° C. for reaction. The reaction was terminated when the residual isocyanate group concentration was 0.1% by mass or less. Let the obtained urethane (meth) acrylate be urethane (meth) acrylate (UA-1). Urethane (meth) acrylate (UA-1) has an average of 2.8 structural units derived from the polypropylene glycol and two ethylenically unsaturated groups.

Synthesis Example 2 Synthesis of urethane (meth) acrylate (UA-2):
In a reaction vessel equipped with a stirrer, 87.29 parts of polypropylene glycol having a number average molecular weight of 2000, 10.30 parts of 2,4-tolylene diisocyanate, 0.024 of 2,6-di-t-butyl-p-cresol The temperature of the solution was adjusted to 25 ° C. while stirring them. After adding 0.80 part of dibutyltin dilaurate, the liquid temperature was gradually raised to 45 ° C. over 1 hour with stirring. Thereafter, the liquid temperature was raised to 50 ° C. for reaction. After the residual isocyanate group concentration became 1.34% by mass (ratio to the charged amount) or less, 1.81 parts of 2-hydroxyethyl acrylate and 0.50 parts of methanol were added and stirred at a liquid temperature of about 60 ° C. , Reacted. The reaction was terminated when the residual isocyanate group concentration was 0.1% by mass or less. Let the obtained urethane acrylate be urethane (meth) acrylate (UA-2). Urethane (meth) acrylate (UA-2) has an average of 2.8 structural units derived from the polypropylene glycol, one ethylenically unsaturated group and one structural unit derived from methanol.

Synthesis Example 3 Synthesis of urethane (meth) acrylate (UA-3):
In a reaction vessel equipped with a stirrer, 85.12 parts of polypropylene glycol having a number average molecular weight of 2000, 10.04 parts of 2,4-tolylene diisocyanate, 0.024 of 2,6-di-t-butyl-p-cresol The temperature of the solution was adjusted to 25 ° C. while stirring them. After adding 0.80 part of dibutyltin dilaurate, the liquid temperature was gradually raised to 45 ° C. over 1 hour with stirring. Thereafter, the liquid temperature was raised to 50 ° C. for reaction. After the residual isocyanate group concentration became 1.34% by mass (ratio to the charged amount), 2.98 parts of γ-mercaptooxypropyltrimethoxysilane and 1.76 parts of 2-hydroxyethyl acrylate were added, and the liquid temperature The reaction was stirred at about 60 ° C. The reaction was terminated when the residual isocyanate group concentration was 0.1% by mass or less. Let the obtained urethane acrylate be urethane (meth) acrylate (UA-3). Urethane (meth) acrylate (UA-3) has an average of 2.8 structural units derived from the polypropylene glycol, 1 ethylenically unsaturated group, and structural units derived from the γ-mercaptooxypropyltrimethoxysilane. However, it does not have a structural unit derived from a monoalcohol having 1 to 3 carbon atoms.

Examples 1-3, Comparative Examples 1-2
Liquid curable resin compositions having the compositions shown in Table 1 were produced, and physical properties were evaluated according to the following methods.

[Evaluation methods]
(1) Storage stability of resin solution:
The liquid curable resin composition was allowed to stand at −36 ° C. for 30 days and then visually observed to evaluate the storage stability. The case where it was transparent was designated as “◯”, and the case where white turbidity was observed was designated as “x”.

(2) Breaking strength and breaking elongation:
A liquid curable resin composition was applied on a glass plate using an applicator bar having a thickness of 200 μm, and was cured by irradiating with ultraviolet rays having an energy of 1 J / cm ² in the air to obtain a test film. Using a tensile tester (manufactured by Shimadzu Corporation, AGS-50G), the breaking strength and breaking elongation of the test piece were measured under the following measurement conditions.
Tensile speed: 50 mm / distance between marked lines (measurement distance): 25 mm
Measurement temperature: 23 ° C
Relative humidity: 50% RH

(3) Viscosity:
The viscosity at 25 ° C. of the compositions obtained in Examples and Comparative Examples was measured with a viscometer B8H-BII (manufactured by Tokimec).

(4) Young's modulus:
The Young's modulus after curing of the compositions obtained in Examples and Comparative Examples was measured. A liquid curable resin composition was applied onto a glass plate using an applicator bar having a thickness of 354 μm, and this was cured by irradiation with ultraviolet rays having an energy of 1 J / cm ^{2 in} the air to obtain a test film. A strip-shaped sample was prepared from the cured film so that the stretched portion had a width of 6 mm and a length of 25 mm. A tensile test was performed in accordance with JIS K7127 using a tensile tester AGS-1KND (manufactured by Shimadzu Corporation) under conditions of a temperature of 25 ° C. and a humidity of 50%. The Young's modulus was obtained from the tensile strength at a tensile rate of 1 mm / min and a strain of 2.5%.

(5) Curing speed:
The curing rate of the compositions obtained in the examples and comparative examples was measured. A liquid curable resin composition is applied on a glass plate using an applicator bar having a thickness of 200 μm, and this is cured by irradiating with ultraviolet rays having an energy of 20 mJ / cm ² and 1 J / cm ² in air. Got two kinds. From these two types of cured films, strip-shaped samples were prepared so that the stretched portions had a width of 6 mm and a length of 25 mm, respectively. A tensile test was performed in accordance with JIS K7127 using a tensile tester AGS-1KND (manufactured by Shimadzu Corporation) at a temperature of 23 ° C. and a humidity of 50%. The Young's modulus was obtained from the tensile strength at a tensile rate of 1 mm / min and a strain of 2.5%. The ratio of Young's modulus of the test film cured at 20 mJ / cm ² and Young's modulus of the test film cured at 500 mJ / cm ² was calculated from the formula (1), and the curing rate of the composition was evaluated.

(Equation 1)
Curing speed (%)
= [200 mJ / cm ² cured film Young's modulus] / [1 J / cm ² cured film Young's modulus] (1)

In the table,
N-vinylcaprolactam: manufactured by Sartomer,
2-ethylhexyl acrylate: a compound represented by the following formula (BASF)
_{CH 2 = CHCOO-CH 2 CH} (CH 2 CH 3) - (CH 2) 3 -CH 3
Lauryl acrylate: a compound represented by the following formula (manufactured by Kyoeisha Chemical Co., Ltd.)
_{CH 2 = CHCOO- (CH 2)} 11 -CH 3
Lucillin: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (BASF)

  As is apparent from Table 1, the composition of the present invention has a resin liquid viscosity suitable as an optical fiber coating agent, provides a Young's modulus suitable as a primary material, and also provides a storage stability of the resin liquid and a cured product. It turns out that it is excellent in water resistance. When an acrylate monomer that does not correspond to the chemical formula (1) is used in place of the component (B), when the alkyl chain has a branched structure such as 2-ethylhexyl acrylate, a linear alkyl chain such as lauryl acrylate In both cases, the storage stability was lowered and the Young's modulus was excessive. In addition, when the urethane (meth) acrylate was only the component (A1) and not the component (A2) (Comparative Example 2), the Young's modulus was excessive, making it unsuitable as a primary material.

Claims (6)

The following components (A1), (A2), (B) and (C):
(A1) urethane (meth) acrylate having two or more structural units derived from an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000 and two ethylenically unsaturated groups,
(A2) Two or more structural units derived from an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000, one ethylenically unsaturated group and a structure derived from a monoalcohol having 1 to 3 carbon atoms Urethane (meth) acrylate having units,
(B) an alkyl (meth) acrylate represented by the following formula (1),
^{_{CH 2 = C (R 1)}} COO- (CH 2) n -CH (CH 3) 2 (1)
(R ¹ represents a hydrogen atom or a methyl group, and n represents an integer of 4 to 8)
(C) A liquid curable resin composition for a primary material of an optical fiber containing a polymerization initiator. Furthermore, component (A3):
(A3) Two or more structural units derived from an aliphatic polyether polyol having a number average molecular weight of 1,000 to 4,000, one structural unit derived from ethylenically unsaturated groups and a structural unit derived from γ-mercaptopropyltrimethoxysilane The liquid curable resin composition for a primary material of an optical fiber according to claim 1, which contains a urethane (meth) acrylate having odor.   The liquid curable resin composition for a primary material of an optical fiber according to claim 2, wherein the component (A3) has a structure derived from γ-mercaptopropyltrimethoxysilane.   The component (B) is contained in an amount of 50% by mass or more based on 100% by mass of the total amount of the compound having one ethylenically unsaturated group (excluding urethane (meth) acrylate) contained in the composition. Liquid curable resin composition for primary materials of optical fiber as described in any one of 1-3.   The primary coating layer of the optical fiber obtained by hardening | curing the liquid curable resin composition as described in any one of Claims 1-4.   An optical fiber having the primary coating layer according to claim 5.