JPH08134156A - Photo-setting resin composition - Google Patents

Abstract

PURPOSE: To obtain the subject low-viscosity composition suitable as an optical fiber coating material, having excellent curing properties, reliability and storage stability, comprising a urethane (meth)acrylate, N-vinylpyrrolidone, a compound containing a specific group 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 and propylene glycol, (B) N-vinylpyrrolidone, (C) a compound containing 2,2,6,6-tetramethyl-4-piperidyl [e.g. bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate] and (D) a photopolymerization initiator (e.g. 2, 4, 6- trimethylbenzoyldiphenylphosphine oxide).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocurable resin composition, and more particularly to a resin composition suitable for coating a glass fiber for optical transmission (hereinafter abbreviated as "optical fiber" in the present specification), more specifically, a primary fiber composition The present invention relates to a resin composition suitable as a coating material, a secondary coating material, a tape material and a connecting material.

[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, the glass surface is first coated with a material having an extremely low elastic modulus in order to minimize microbending, and then a secondary coating with a material having flexibility and a high elastic modulus. Has been done. Further, in order to bundle several optical fibers coated with these resins side by side, they are resin-coated with a material (tape material) having a high elastic modulus. Further, in some cases, the tape material may be resin-coated with a material (coupling material) for connecting the tape materials. Desirable properties common to these primary coating materials, secondary coating materials, tape materials and connecting materials are that they have appropriate viscosities, excellent curability, and low temperature dependence of elastic modulus,
Excellent long-term reliability is required.

In order to achieve the above object, N-vinylpyrrolidone is widely used as a reactive diluent in a photocurable resin composition (for example, Japanese Patent Publication No. 4-20241).
2 and the composition described in JP-B-4-310547). This is based on the feature that N-vinylpyrrolidone has excellent dilutability, high copolymerizability, and excellent curability. On the other hand, a resin composition containing N-vinylpyrrolidone has a problem that it tends to thicken after long-term storage. When the viscosity is increased, it is necessary to change the drawing conditions according to the increase in the production, which is not preferable. Further, in recent years, there has been an increasing demand for reliability of the resin, and there is a demand for a resin having excellent storage stability more than ever before.

[0004]

The present invention has a low viscosity,
It is an object of the present invention to provide a photocurable resin composition having high curability and reliability and excellent in storage stability.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the cause of thickening of a resin composition containing N-vinylpyrrolidone is mainly due to a dimerization reaction of N-vinylpyrrolidone. The present invention has been completed, and it was found that the dimerization reaction was suppressed by the addition of a specific component, and the thickening of the resin composition could be suppressed, and the present invention was completed. That is, the present invention is as follows. 1) (a) Urethane (meth) acrylate [(meth)
Acrylate means methacrylate or acrylate. same as below. ], (B) N-vinylpyrrolidone,
A photocurable resin composition comprising (c) a compound having a 2,2,6,6-tetramethyl-4-piperidyl group and (d) a photopolymerization initiator. 2) The photocurable resin composition according to item 1), which further contains a reactive diluent (excluding N-vinylpyrrolidone) as the component (e).

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 not particularly limited, but is 400 to 40,000.
Is preferred.

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 above-mentioned component (a) is contained in the composition of the present invention.
It is preferable that the compounding amount be about 90% 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) 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.

Examples of the component (c) include bis (2,2
2,6,6-Tetramethyl-4-piperidyl) sepacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sepacate, succinic acid-bis (2,2,6,6)
6-tetramethyl-4-piperidinyl) ester, 4-
Benzoyloxy-2,2,6,6-tetramethylpiperidine, 8-acetyl-3-dodecyl-7,7,9,9
-Tetramethyl-1,3,8-triazaspiro [4,
5] Decane-2,4-dione, dimethyl succinate. 1-
(2-hydroxyethyl) -4-hydroxy-2,2
6,6-Tetramethylpiperidine polycondensate, poly [{6
-(1,1,3,3-tetramethylbutyl) amino-
1,3,5-triazine-2,4-diyl} {(2,
2,6,6-Tetramethyl-4-piperidyl) imino}
Hexamethylene {(2,2,6,6-tetramethyl-4
-Piperidyl) imino}], N, N'-bis (3-aminopropyl) ethylenediamine.2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-
Piperidyl) amino] -6-chloro-1,3,5-triazine condensate, 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2) , 2,6,6-pentamethyl-4-piperidyl) and the like.

The above component (c) is added to the composition of the present invention in an amount of 0.
It is preferably blended in an amount of 01 to 5% by weight, particularly 0.1 to 3% by weight. When it is less than 0.01% by weight,
The effect of suppressing thickening of the resin composition cannot be obtained. Also, 5
If it exceeds 5% by weight, the curability is lowered, which is not preferable.

The photopolymerization initiator of the component (d) 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 (d) is added to the composition of the present invention in an amount of 0.1 to 0.1%.
It is blended so as to be 10% by weight, preferably 0.5 to 7% by weight.

Examples of the reactive diluent as the component (e) include monofunctional compounds and polyfunctional compounds having an ethylenically unsaturated group. Acrylic and vinyl groups are preferred as the ethylenically unsaturated 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, nonylphenoxypoly Ropylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxyhydroxypropyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate Etc.

Examples of polyfunctional compounds include 1,4 butanediol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, ethylene glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone. Modified dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate,
Pentaerythritol tri (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate , Caprolactone-modified tris (acryloxyethyl) isocyanurate, tris (methacryloxyethyl) isocyanurate, tricyclodecane dimethanol di (meth) acrylate and the like. You may use these reactive diluents individually by 1 type or in combination of 2 or more types.

The photocurable resin composition of the present invention may further contain a silane coupling agent, an antioxidant, a colorant, and
A release agent, a polymerization inhibitor, an ultraviolet absorber, a filler, a leveling agent, a lubricant, a plasticizer and the like can be added. The photocurable resin composition of the present invention can be produced by mixing the above-mentioned components by a conventional method.

[0019]

The photocurable resin composition of the present invention has low viscosity, high curability and reliability, and excellent storage 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.

[0020]

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 1 119.2 g of 2,4-tolylene diisocyanate in a four-necked flask equipped with a thermometer, stirrer and reflux condenser,
0.5 g of dibutyltin dilaurate and 0.1 g of phenothiazine as a polymerization inhibitor were charged. 79.4 g of 2-hydroxyethyl acrylate was gradually added dropwise at 60 ° C., and then reacted at 60 ° C. for 2 hours. Next, number average molecular weight 30
005.3 polypropylene glycol 205.3 g, number average molecular weight 700 polypropylene glycol 83.8 g,
Add 11.7 g of propylene glycol and add 3 at 70 ° C.
After reacting for a time, 500 g of urethane acrylate was obtained. To this, 180 g of tris (2-acryloxy) isocyanurate, 120 of tricyclodecanyl acrylate
g, 150 g of N-vinylpyrrolidone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide 2
0 g, bis (1,2,2,6,6-pentamethyl-4-
10 g of piperidyl) sepacate was added and mixed to obtain the desired composition. In evaluating the storage stability of this composition, an accelerated deterioration test at 60 ° C. was performed. That is, this composition was placed in a constant temperature bath at 60 ° C. and the change in viscosity was traced. The results are shown in Table 1. Further, the composition before heating and the composition after heating for 1 month at 60 ° C. were respectively coated on a glass plate in a thickness of 130 μm, and then 120 W
It was cured with an irradiation light amount of 200 mJ / cm ² using the metal halide lamp of. Table 2 shows the results of measuring the physical properties of each cured film.

Example 2 A 4-necked flask equipped with a thermometer, a stirrer and a reflux condenser was charged with 74.2 g of 2,4-tolylene diisocyanate, 0.5 g of dibutyltin dilaurate and 0.1 g of phenothiazine as a polymerization inhibitor. I prepared it. After slowly adding 49.4 g of 2-hydroxyethyl acrylate at 60 ° C.,
The reaction was carried out at 60 ° C for 2 hours. Next, number average molecular weight 2000
425.8 g of polypropylene glycol of
The reaction was carried out at 0 ° C. for 3 hours to obtain 550 g of urethane acrylate. 250 g of tris (2-acryloxy) isocyanurate, 70 g of nonylphenoxymonoethylene glycol acrylate, 1 N-vinylpyrrolidone
30 g, 2,4,6-trimethylbenzoyldiphenylphosphine oxide 15 g, 2-methyl-1- (4
-Methylthiophenyl) -2-morpholino-propane-
10 g of 1-one and 10 g of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sepacate were added and mixed to obtain the intended composition. The storage stability of this composition and the evaluation of the physical properties of the cured film were carried out in the same manner as in Example 1. The results are shown in Tables 1 and 2.

Comparative Example 1 In the formulation of Example 1, bis (1,2,2,6,6-
A composition was obtained in the same manner as in Example 1 except that pentamethyl-4-piperidyl) sepacate was not added and mixed.
The storage stability was evaluated in the same manner as in Example 1. The results are shown in Table 1. Table 2 shows the physical properties of the film cured in the same manner as in Example 1.

Comparative Example 2 In the formulation of Example 2, bis (1,2,2,6,6-
A composition was obtained in the same manner as in Example 2 except that pentamethyl-4-piperidyl) sepacate was not added and mixed.
The storage stability was evaluated in the same manner as in Example 1. The results are shown in Table 1. In addition, Table 2 shows the physical properties of the film cured in the same manner as in Example 2.

[0024]

[Table 1]

[0025]

[Table 2]

Claims (2)

[Claims] 1. (a) Urethane methacrylate or urethane acrylate, (b) N-vinylpyrrolidone,
A photocurable resin composition comprising (c) a compound having a 2,2,6,6-tetramethyl-4-piperidyl group and (d) a photopolymerization initiator. 2. Further, as the component (e), a reactive diluent (N
-Except vinylpyrrolidone), The photocurable resin composition according to claim 1, wherein