JPH08134157A - Photocurable resin composition - Google Patents

Abstract

PURPOSE: To obtain the subject low-viscosity composition suitable for coating an optical fiber, having low Young's modulus in tension and excellent curing properties, adhesion of cured material and wet heat resistance, comprising a urethane (meth)acrylate, a diluent, a carboxylic acid, a silane coupling agent and a photopolymerization initiator. CONSTITUTION: This composition comprises (A) a urethane (meth)acrylate (e.g. a urethane acrylate obtained by reacting 2,4-tolyene diisocyanate with 2- hydroxyethyl acrylate and reacting the reaction product with polypropylene glycol), (B) a monofunctional reactive diluent (e.g. nonylphenoxymonoethylene glycol acrylate), (C) a carboxylic acid (e.g. 2-acryloyloxyethylphthalic acid), (D) a silane coupling agent (e.g. γ-acryloxypropyltrimethoxysilane) and (E) a photopolymerization initiator (e.g. 2,4,6-trimethylbenzoyldiphenylphosphine oxide).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photocurable resin composition, which is characterized by excellent adhesion to a glass substrate.
Particularly, a resin composition suitable for coating a glass fiber for optical transmission (hereinafter, abbreviated as an optical fiber in the present specification), more specifically, a cured product thereof has a low Young's modulus, adhesion to an optical fiber, long-term stability of adhesion, etc. The present invention relates to a resin composition which is excellent in optical fiber coating and is suitable for coating.

[0002]

2. Description of the Related Art Optical fibers are fragile and easily scratched and poor in flexibility. They are easily destroyed by a small external force, and when mechanical external pressure is applied, the light transmitted by microbending is weakened, resulting in transmission loss. Cause For this reason, it is desirable that the glass surface be primarily coated with a material having a very low modulus to minimize microbending. Further, the properties required for this primary coating material are required to have an appropriate viscosity, excellent curability, low temperature dependence of elastic modulus, and long-term reliability.

If the adhesion to the optical fiber is weak,
When exposed to a harsh environment (high temperature, high humidity, etc.), microscopic peeling occurs at the interface between the primary coating material and the optical fiber, resulting in a decrease in adhesion, resulting in an increase in transmission loss. Therefore, there is a demand for a material that has a higher adhesion to the optical fiber and that can maintain the adhesion stably for a long period of time.

[0004]

DISCLOSURE OF THE INVENTION The present invention has a low Young's modulus, a low viscosity and a high curability, and the adhesion of a film cured on a base material, the wet heat resistance and the oil resistance of the adhesion. An object of the present invention is to provide a photocurable resin composition having excellent long-term stability.

[0005]

Means for Solving the Problems As a result of intensive studies aimed at improving the adhesion between the silane coupling agent and the glass, the present inventors have found that a resin composition containing a carboxylic acid contains a silane coupling agent and a glass. The present invention has been completed by finding out that the binding of the above is strengthened. That is, the present invention is as follows. 1) (a) Urethane (meth) acrylate [(meth) acrylate represents methacrylate or acrylate. same as below. ], (B) monofunctional reactive diluent, (c)
Carboxylic acid, (d) silane coupling agent and (e)
A photocurable resin composition comprising a photopolymerization initiator. 2) The photocurable resin composition according to item 1), wherein the carboxylic acid is a carboxylic acid compound having an ethylenically unsaturated group. 3) The carboxylic acid compound having an ethylenically unsaturated group is
The photocurable resin composition according to item 2), which is a (meth) acrylate monomer containing a carboxyl group.

The urethane (meth) acrylate (a) used in the present invention is obtained by reacting a polyisocyanate, a polyol and a hydroxyl group-containing (meth) acrylate by a known method. That is, a polyisocyanate and a polyol are first reacted to generate a high molecular weight polyisocyanate, which is then reacted with a hydroxyl group-containing (meth) acrylate to bond an unsaturated group to the terminal, or first, a hydroxyl group-containing It is obtained by reacting a (meth) acrylate with a polyisocyanate and then reacting the obtained unsaturated polyisocyanate with a polyol in the presence of polyisocyanate in some cases. The number average molecular weight of the component (a) is 1500 to 60,000, particularly 2000 to 40,000.
It is preferred that

The polyisocyanate used here is not particularly limited, but for example, isophorone diisocyanate, 2,4-tolylene diisocyanate,
2,6-Tolylene diisocyanate, m-Phenylene diisocyanate, p-Phenylene diisocyanate, Hexamethylene diisocyanate, Trimethylhexamethylene diisocyanate, 4,4'-Diphenylmethane diisocyanate, Hydrogenated diphenylmethane diisocyanate, 1,3-Xylylene diisocyanate, 1, 4-xylylene diisocyanate etc. are mentioned.

The hydroxyl group-containing (meth) acrylate is not particularly limited, but for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,4. There are butanediol mono (meth) acrylate and caprolactone-modified 2-hydroxyethyl (meth) acrylate.

Further, the polyol is not particularly limited, and examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol and copolymers thereof, ethylene glycol,
Propylene glycol, 1,4-butanediol, 2,
2'-thiodiethanol etc. are mentioned. These polyols may be used alone or in combination of two or more.

The component (a) is contained in the composition of the present invention in an amount of 20 to 9
It is preferably blended so as to be 0% by weight, particularly 40 to 80% by weight. When the proportion of the urethane (meth) acrylate (a) is less than 20% by weight, the elongation at break of the cured product of the obtained composition decreases, and when it exceeds 90% by weight, the viscosity of the composition increases and the handling becomes easy. It will be difficult.

The component (b) acts as a reactive diluent, and includes a monofunctional compound having an ethylenically unsaturated group. The ethylenically unsaturated group is preferably an acrylic group, a methacrylic group or a vinyl group. An example is given below. Examples of the monofunctional compound include butanediol mono (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, N, N
-Diethylaminoethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, isobornyl (meth) Acrylate, lauryl (meth) acrylate, acryloylmorpholine, N-vinylcaprolactam, nonylphenoxy polyethylene glycol (meth) acrylate, nonylphenoxy polypropylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxyhydroxypropyl (meth) acrylate, phenoxy Diethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene Call (meth) acrylate, tetrahydrofurfuryl (meth) acrylate. These reactive diluents may be used alone or in combination.
You may use it in combination of 2 or more types.

The component (b) is contained in the composition of the present invention in an amount of 3 to 40.
It is preferable that the composition is blended so as to be wt%, particularly 5 to 30 wt%. If it is less than 3% by weight, the curing rate will be low, and if it exceeds 40% by weight, the viscosity will be too low and it will be difficult to use.

The component (c) is not particularly limited, but for example, acetic acid, propionic acid, butyric acid, oxalic acid,
Malonic acid, saturated aliphatic carboxylic acids such as succinic acid, oleic acid, fumaric acid, citraconic acid, aliphatic carboxylic acids having an ethylenically unsaturated group such as mesaconic acid, toluic acid,
Aromatic carboxylic acids such as phthalic acid and acrylic acid, methacrylic acid, 2-acryloyloxyethyl succinic acid, 2
Examples include (meth) acrylate monomers containing a carboxyl group such as acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid, ω-carboxy-polycaprolactone monoacrylate, and acrylic acid dimer.

The component (c) is added to the composition of the present invention in an amount of 0.1 to 0.1%.
It is preferably blended in an amount of 20% by weight, particularly 0.5 to 10% by weight. If it is less than 0.1% by weight, sufficient adhesion cannot be obtained. Further, if it exceeds 20% by weight, the curability is deteriorated, which is not preferable.

The component (d) is not particularly limited, but for example, vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β-amino Ethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyl Trimeth Shishiran, .gamma.-chloropropyl trimethoxy silane, and the like. These silane coupling agents may be used alone or in combination of two or more. The component (d) is added to the composition of the present invention in an amount of 0.
It is preferably blended in an amount of 5 to 10% by weight, particularly 1 to 5% by weight.

The photopolymerization initiator of the component (e) used in the present invention is not particularly limited, but for example, benzophenone, 4-phenylbenzophenone, hydroxybenzophenone, acetophenone, 2-hydroxy-2.
-Methyl-1-phenylpropan-1-one, benzyl, benzoin, benzoin isobutyl ether, benzoin isopropyl ether, benzoin ethyl ether, benzoin methyl ether, 4,4'-bisdimethylaminobenzophenone, benzyldimethylketal,
Thioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 2,4
-Diisopropylthioxanthone, 2-methyl-1-
[4- (Methylthio) phenyl] -2-morpholinopropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-hydroxy-2
-Methyl-1-phenylpropan-1-one, methylphenylglyoxylate, camphorquinone, 1-hydroxycyclohexylphenylketone or mixtures thereof are used. The component (e) is preferably added to the composition of the present invention in an amount of 0.1 to 10% by weight, particularly 0.5 to 7% by weight.

The photocurable resin composition of the present invention further comprises an antioxidant, a colorant, a release agent, a polymerization inhibitor, an ultraviolet absorber, a light stabilizer, a filler, a leveling agent, a lubricant and a plasticizer, if necessary. Etc. can be blended. The photocurable resin composition of the present invention can be produced by mixing the above-mentioned components by a conventional method.

[0018]

The photocurable resin composition of the present invention has a low Young's modulus, a low viscosity and a high curability, and the adhesion of a film cured on a substrate, and the wet heat resistance of the adhesion. And excellent in oil resistance and long-term stability. The resulting coating has the basic properties required for optical fiber coatings. Therefore, it is a particularly excellent material for coating an optical fiber.

[0019]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. Example 1 A 4-necked flask equipped with a thermometer, a stirrer and a reflux condenser was charged with 43.5 g of 2,4-tolylene diisocyanate, 0.58 g of dibutyltin dilaurate and 0.11 g of phenothiazine as a polymerization inhibitor. After slowly adding dropwise 14.3 g of 2-hydroxyethyl acrylate at 60 ° C., the mixture was reacted at 60 ° C. for 2 hours. Next, number average molecular weight 30
542.2 g of polypropylene glycol of 00 was added and reacted at 70 ° C. for 3 hours to obtain 600.7 g of urethane acrylate. To this, 300 g of nonylphenoxymonoethylene glycol acrylate, 100 g of N-vinylpyrrolidone, 20 g of 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 30 g of 2-acryloyloxyethylphthalic acid, and 30 g of γ-acryloxypropyltrimethoxysilane. The intended composition was obtained by adding and mixing. The viscosity of this composition at 25 ° C. was 120 W / c after being applied on a glass plate to a thickness of 250 μm.
25 mJ / cm ² using m metal halide lamp
Table 1 shows the measurement results of Young's modulus and curability in the case of curing with an irradiation light amount of 500 mJ / cm ² . The curability was evaluated by the following formula. In addition, the results of the adhesion strength of the film obtained by curing this composition on a glass plate with an irradiation light amount of 200 mJ / cm ² , the wet heat resistance test of the adhesion strength and the oil resistance test (peeling strength of the film to the glass before and after the test) are shown. It shows in Table 2. Here, the moist heat resistance test and the oil resistance test were conducted by the following methods. -Moisture and heat resistance test A film cured on a glass plate with an ultraviolet ray of 200 mJ / cm ² was placed in a constant humidity chamber of 60 ° C and 95% RH for 30 days, taken out, and the peel strength of the film was measured.・ Oil resistance test: A film cured on a glass plate with 200 mJ / cm ² ultraviolet rays is dipped in jelly oil and placed in an 80 ° C constant temperature bath for 3
After being put in for 0 days and taken out, the peel strength of the film was measured.

Comparative Example 1 Example 1 was repeated except that γ-acryloxypropyltrimethoxysilane was not added and mixed in the formulation of Example 1.
A composition was obtained in the same manner as in. In the same manner as in Example 1, the adhesion of the film, the results of the wet heat resistance test of the adhesion and the oil resistance test are shown in Table 2.

[0021]

[Table 1]

[0022]

[Table 2]

Claims (3)

[Claims] 1. A urethane methacrylate or urethane acrylate, (b) a monofunctional reactive diluent, (c)
Carboxylic acid, (d) silane coupling agent and (e)
A photocurable resin composition comprising a photopolymerization initiator. 2. The photocurable resin composition according to claim 1, wherein the carboxylic acid is a carboxylic acid compound having an ethylenically unsaturated group. 3. The photocurable resin composition according to claim 2, wherein the carboxylic acid compound having an ethylenically unsaturated group is a methacrylate monomer or an acrylate monomer containing a carboxyl group.