JPS6257411A - Resin composition and coating agent - Google Patents

Abstract

PURPOSE:The titled novel composition suitable for topcoating for optical fiber, having high curing rate and large elongation of cured film of coating, obtained by blending polyurethane acrylate with specific components such as diacrylic acid ester, etc. CONSTITUTION:The aimed composition obtained by blending (A) polyurethane (meth)acrylate with (B) a di(meth)acrylic acid ester shown by the formula (average value of m and n is 0-5 and average total value of m+n is 1-10; R is H or CH3), (C) an ethylenic unsaturated monomer (preferably hydrogenated dicyclopentadiene acrylate etc.,) and (D) a photopolymerization initiator as an arbitrary component. The component B, for example, is obtained by reacting an adduct of tricyclodecanedimethylol with epsilon-caprolactone with acrylic acid in the presence of an esterification catalyst and a polymerization inhibitor. Benzoin ethyl ether, etc., having improved shelf stability is preferable as the component D.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a resin composition and a coating agent for optical glass fibers, and in particular to a primary or buffer coating applied to protect the glass surface of an optical fiber. The present invention relates to an ultraviolet curable top coating composition suitable for.

(Prior Art) Optical fibers have a high information transmission performance and are relatively immune to external interference, so their use has increased significantly in recent years, especially in the communications field.

Optical fibers are generally made of glass because they are used in the telecommunications field. However, glass fibers are inherently brittle and are easily broken due to chemical agitation by water vapor, making them difficult to handle. Therefore, conventionally, optical glass fibers are
The surface is coated with resin. Conventionally, epoxy resins, urethane resins, etc. have been used as such resin coating materials, but they require a long time to cure, resulting in poor productivity.They also lack flexibility, which impairs transmission characteristics due to lateral pressure. There are some drawbacks. Recently, ultraviolet curable compositions containing urethane acrylate have been extensively studied in order to improve the above-mentioned drawbacks, and a method for forming an ultraviolet curable composition for optical glass fibers and such a coating has been proposed.
No. 223,638 and Japanese Unexamined Patent Publication No. 59-170154.

They have selected very low modulus primary coatings as a means of solving the above problems with some success. However, in order to provide low modulus, it is desirable to apply a top coating over the sill primary coating at the expense of the hardness and toughness desired in the coating in contact with the glass, and to apply a top coating over the sill primary coating. things are being considered. For example, an ultraviolet curable top coating composition is proposed in JP-A-59-170155.

(Problems to be Solved by the Invention) Currently used ultraviolet curable top coating compositions have the advantage of fast curing speed and the ability to easily and accurately obtain desired properties, but they have high water absorption properties and are difficult to absorb. The disadvantage is that the glass fiber is easily damaged by the process, and the elongation of the cured film is small, resulting in the fiber being damaged when the fiber is wound during fiber manufacturing, often resulting in defective products.

(Means for Solving the Problems) In order to solve the above problems, the present inventors have conducted intensive research and found that the curing speed is fast, the resin film obtained by curing has a large elongation, and the water absorption rate is low. The present invention has been completed by successfully providing a new resin composition suitable for the top coat of optical glass fibers for light transmission. That is, the present invention provides: (1) Polyurethane (meth)acrylate (A).

General formula (1) (wherein, the average value of m and n is a number of 0 to 5, preferably 0 to 3, respectively, and the average total value of m + n is 1 to 1
R is preferably a number from 1 to 6, and R is H or CH3. ) Di(meth)acrylic ester (B
), a monoethylenically unsaturated monomer (C), and a photopolymerization initiator (D) as an optional component.

(2) polyurethane (meth)acrylate (A),
General formula CI) CC:= CH, (1) Value is 1-1
0 is preferably a number from 1 to 6, and R is H or CH3. ) Di(meth)acrylic ester (B
), a monoethylenically unsaturated monomer (C), and a photopolymerization initiator (D).

In the present invention, polyurethane (meth)acrylate (A)
is used, but its average molecular weight is usually 500 or more, preferably about 500 to 5,000.

As polyurethane (meth)acrylates such as
Polyurethane (meth)acrylate of polyether polyol with ether group in the molecule, polyurethane (meth)acrylate of carbonate polyol with carbonate group, polyurethane (meth)acrylate of polyester polyol with ester group, or ether group and ester group Examples include polyurethane (meth)acrylate, which has both of these in its molecule. Examples of polyether polyols include polypropylene glycol, polyethylene glycol, polytetramethylene glycol, 1,3-butylene glycol, 1°4-
Butylene glycol, 1,6-hexanediol, neopentyl glycol, cyclohexane dimetatool, 2
．． Compounds in which ethylene oxide or propylene oxide is added to 2-bis(4-hydroxycyclohexyl)propane, bisphenol A, etc. can be used.

Polyester polyol can be obtained by reacting an alcohol component and an acid component.

For example, polypropylene glycol, polyethylene glycol, polytetramethylene glycol and 1,3-butylene glycol, 1,4-butylene glycol, 1.
Compounds in which ethylene oxide, propylene oxide is added to 6-hexanediol, neopentyl glycol, cyclohexane dimetatool, 2,2-bis(4-hydroxychlorohexyl)propane, bisphenol A, etc., and compounds in which nibsilone caprolactone is added, etc. is used as the alcohol component, and as one acid component, dibasic acids such as phthalic acid, tetrahydrophthalic acid, adipic acid, sebacic acid, azelaic acid, hexahydrophthalic acid, dodecanedicarboxylic acid, and their anhydrides can be used. . A compound obtained by simultaneously reacting the above-mentioned alcohol component, acid component, and apron caprolactone can also be used as the polyester polyol.

Carbonate polyol can be produced, for example, as follows. That is, carbonate derivatives such as diphenyl carbonate, bis-chlorophenyl carbonate, dinaphthyl carbonate, phenyl-tolyl-carbonate, phenyl-chlorophenyl-carbonate, 2-tolyl-4-tolyl-carbonate, dimethyl carbonate, diethyl carbonate, etc. Diaryl carbonates or dialkyl carbonates and diols, examples LId, 1,6-hexanediol, neopentyl glycol, 1°4-butanediol, 1,8-octanediol, 1,4-bis-(hydroxymethyl)-
7 Chlohexane, 2-methylpropadiol dipropylene glycol, diptylene glycol or the above diol compounds and dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, hexahydrophthalic acid or ε- It can be obtained by transesterification with polyether polyol, which is a reaction product of caprolactone. It can also be produced by reacting phosgene with the diols mentioned above.

In order to obtain polyurethane (meth)acrylate (A) using such polyester polyols, polycarbonate polyols, and polyester polyols, substantially no organic diisocyanate and a polymerizable monomer having a hydroxyl group are added to the hydroxyl group of the polyol.
Polyurethane (meth)acrylate (A) can be obtained by reacting until it contains no O group. Representative organic diisocyanates include aromatic diisocyanates such as tolylene diisocyanate and 4°4'-diphenylmethane diisocyanate, alicyclic diisocyanates such as inphorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate, and hexamethylene diisocyanate. There are aliphatic diisocyanates such as 2'-trimethylhexamethylene diinocyanate, and polymerizable monomers having hydroxyl groups include β-hydroxyethyl (meth)acrylate, β-hydroxypropyl (meth)acrylate, β
-Hydroxylauryl (meth)acrylate, nibsilone caprolactone - (meth) containing hydroxyl groups such as β-hydroxyethyl (meth)acrylate adducts
Acrylate etc. The reaction between NCO groups and OH groups can proceed without a catalyst, but for example, tertiary amines such as triethylamine, organometallic compounds such as dibutyltin silaurylate and dibutyltin diacetate, or tin chlorides, etc. Conventional catalysts may also be used.

The proportion of polyurethane (meth)acrylate (A) used in the resin composition and coating agent is preferably 20 to 70% by weight, particularly preferably 30 to 60% by weight.

In the present invention, a di(meth)acrylic acid ester (B) represented by the general formula CI) is used. The manufacturing method of di(meth)acrylic acid ester represented by the general formula is disclosed in the patent application filed in 1973.
As described in No. 9-226928, an adduct of tricyclodecane dimethylol and nibucilone caprolactone and (meth)acrylic acid are combined with an esterification catalyst such as para-toluenesulfonic acid or sulfuric acid (preferably (meth) ) and a polymerization inhibitor such as hydroquinone (preferably used at 0.01 to 5% by weight of the raw material mixture) at a temperature of 70 to 130°C. Obtainable. Further, the adduct of lutricyclodecane dimethylol and nibucilone caprolactone used as a raw material can be produced by the reaction of tricyclodecane dimethylol and nibucilone caprolactone. In this case, it is preferable to use a catalyst such as tetraisoglovir titanate or tetraphenyltin in an amount of 0.001 to 1% by weight based on nibsilone caprolactone. The reaction temperature is preferably 50 to 300°C. The amount of di(meth)acrylic acid ester (B) used is preferably 5 to 50% by weight in the resin composition and coating agent, particularly 20 to 4% by weight.
Preferably it is 0% by weight. In the present invention, a monoethylenically unsaturated monomer (C) is used. Various monoethylenically unsaturated monomers can be used, but those whose homopolymer glass transition temperature is as high as possible are used. It is preferable to use dicyclopentadiene oxyethyl acrylate (manufactured by Hitachi Chemical Co., Ltd., FA-512A), and dicyclopentadiene acrylate (manufactured by Hitachi Chemical Co., Ltd., FA-51).
1A), hydrogenated dicyclopentadiene acrylate (manufactured by Hitachi Chemical Co., Ltd., FA-513A), isobornyl (meth)acrylate, hydrogenated β-naphthol (meth)acrylate, tricyclodecanemethylol (meth)acrylate , phenyloxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, adamantane (meth)acrylate, N-vinylpyrrolidone, and the like.

Among the monoethylenically unsaturated monomers, hydrogenated dicyclopentadiene acrylate (
Hitachi Chemical Co., Ltd., FA-513A), dicyclopentadieneoxyethyl acrylate (Hitachi Chemical Co., Ltd.)
FA-512A) manufactured by Kogyo Corporation.

The amount of monoethylenically unsaturated monomer (C) used is preferably 1 to 5% by weight, particularly preferably 20 to 40% by weight, in the resin composition and coating agent. The photopolymerization initiator (D) used in the present invention may be any known photopolymerization initiator, but it is required to have good storage stability after blending. Examples of such photopolymerization initiators include benzoin alkyl ethers such as benzoin ethyl ether, benzoin isobutyl ether, and pentwinisopropyl ether, 2,2-jethoxyacetophenone, and 4'-phenoxy-2,2-dichloroacetophenone. Acetophenone series such as 2-hydroxy-2-methylpropiophenone, 4'-isopropyl-2-hydroxy-2-methylpropiophenone,
Propiophenone series such as 4'-dodecyl 2-hydroxy-2-methylpropiophenone, benzyl dimethyl ketal, 1-hydroquinocyclohexylphenyl ketone, anthraquinone series such as 2-ethylanthraquinone, 2-chloroanthraquinone, etc. , thioxanthone-based photopolymerization initiators, and the like. These photopolymerization initiators (C) may be used alone or in a mixture of two or more in any proportion. The amount used is usually 0% of the resin composition.
-10% by weight, and preferably 0.1-10% by weight, preferably 1-5% by weight of the coating agent.

The resin composition of the present invention may further contain a polymerizable monomer, for example, a polyfunctional acrylate compound such as polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane triacrylate, and epoxy Compounds such as acrylate and polyester acrylate can be further added and used. Further, if desired, a modifying resin and various additives may be added, and examples of the modifying resin include epoxy resin, polyurethane, polybutadiene, polyether, polyamideimide, silicone resin, and phenol resin. Examples of the additives include organosilicon compounds, surfactants, and polymerization inhibitors.

The resin composition of the present invention is useful for coating optical glass fibers, and can also be used for protective coating of plastics.

When coating an optical glass fiber with the coating agent for optical glass fiber of the present invention, a die coating method is suitable as a coating method.

When an optical glass fiber is coated using the coating agent for optical glass fiber of the present invention.

An optical glass base material is drawn, a primary coating agent is coated thereon and cured by ultraviolet irradiation, and then the coating agent of the present invention is applied as a top coating agent over the primary coat, preferably in a thickness of 20 to 300μ. Cover.

The coating agent of the present invention is easily cured by ultraviolet irradiation. The coating agent of the present invention can be cured by ultraviolet irradiation using a conventional method. For example, ultraviolet rays may be irradiated using a low-pressure or high-pressure mercury lamp or a xenon lamp.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples. In addition,
Parts in the examples are 1 part by weight.

[Production example of polyurethane (meth)acrylate (A)]

Production Example 1 Polypropylene glyco” (approximately 2,000 molecules of
, OH value 56.1) 253.1 parts, polyester polyol which is a reaction product of neopentyl glycol, adipic acid and ε-caprolactone (Daicel Chemical Industry Co., Ltd.
251.3 parts of Plaxel L-220AL, molecular weight approximately 2000, OH value 57.5) and 84.7 parts of isophorone diisocyanate were charged, and after raising the temperature, the mixture was reacted at 80°C for 10 hours, and then the reaction solution was cooled to 60°C. , &-caprolactone-β-hydroxyethyl acrylate (manufactured by Daicel Chemical Industries, Ltd., Plaxel FA-2) 91.4 parts, methoquinone 0.3 part, and di-n-butyltin dilaurate 0.1 part, After raising the temperature, the reaction was carried out at 75-80°C. The reaction was continued until completion as indicated by less than about 0.1% free isocyanate groups. The product has the following properties.

Viscosity (60°C> 110p Refractive Index (20°C) 1.4721 Production Example 2゜In the same reactor as Production Example 1, polytetramethylene glycol (molecular weight 2040.OH value 55.0) 714
1 part, 67.6 parts of neopentyl glycol, and 444.6 parts of isophorone diincyanate, and after raising the temperature to 80°C.
The reaction mixture was cooled to 60°C for 2 hours.
- 239 parts of hydroxyethyl acrylate, 0.7 parts of methoquinone, and 0.3 parts of di-n-butyltin dilaurate were charged, and after raising the temperature, the reaction was carried out at 75 to 80'C. Approximately 0.
The reaction was continued until completion as indicated by less than 1% free incyanate groups. The product has the following properties.

Viscosity (25°C) 244p Refractive index (
20°C) 1.4792 [Example of production of diacrylic acid ester of ε-caprolactone adduct of tricyclodecane dimethylol] Synthesis Example 1 In a 21 reactor equipped with a stirrer, a temperature control device, a thermometer, and a condenser, 942.2 parts of tricyclodecane dimethylol, 547.2 parts of nibsilone caprolactone, and 0.27 parts of isopropyl titanate were charged, and the mixture was heated in a nitrogen atmosphere from 150 to
The mixture was heated to 160° C. and reacted until the amount of unreacted nibsilone caprolactone was 1% by weight or less. The obtained adduct was a pale yellow liquid with a hydroxyl value of 360.5 and an acid value of 1.2. As a result of molecular weight measurement, it was shown that the adduct of tricyclodecane dimethylol and nibucilone caprolactone had an average adduct of about one nibucilone caprolactone in the molecule.

Synthesis Example 2 Into the same reactor as Synthesis Example 1, 588.8 parts of tricyclodecane dimethylol and 684 parts of nibsilone caprolactone were added.
8 parts, and 0.34 parts of stannous chloride were added and heated to 110% in nitrogen.
The mixture was heated to ~120°C and reacted until the amount of unreacted nibcylocaprolactone was 1% by weight or less. The obtained adduct is
It was a pale yellow liquid with a hydroxyl value of 266.5 and an acid value of 1.5. As a result of molecular weight measurement, it was shown that the adduct of tricyclodecane dimethylol and nibucilone caprolactone had an average amount of about 2 nibucilone caprolactone adducts in the molecule.

Production Example 3: Into a 21 reactor equipped with a stirrer, a temperature controller, a thermometer, a condenser, and a separator, 470. 3 parts of acrylic acid, 262 parts of acrylic acid, 40 parts of p-toluenesulfonic acid, 198 parts of hydroquinone, 364 parts of benzene, and 906 parts of cyclohexane were charged and heated, and the produced water was distilled and condensed together with the solvent, and only the water was removed from the system using a separator. and the solvent is returned to the reactor. It was cooled when 54.6 parts of water was produced. The reaction temperature was 81-89°C. The reaction mixture was dissolved in 809 parts of benzene and 2024 parts of cyclohexane, neutralized with a 20% aqueous sodium hydroxide solution, and washed three times with 500 parts of 20% brine. The solvent was distilled off under reduced pressure to obtain 5234 parts of a pale yellow liquid. This material has the following properties.

Specific gravity (25° (1,) 1.105 viscosity (
25°C) 241.7 CPS saponification value 40
1.3 mgKOH/g acid value 0.02 mgK
OH/g Refractive Index (20°G) 1.4975 Production Example 4 In the same reactor as Production Example 3, an adduct of 1 mole of tatricyclodecane dimethylol obtained in Synthesis Example 2 and 2 moles of nibsilone caprolactone, 509, was added. 5 parts, 207.4 parts of acrylic acid, 6.2 parts of sulfuric acid, 1.6 parts of hydroquinone, 3 parts of benzene
84 parts and 96 parts of cyclohexane were added to produce water of 57.
The reaction was carried out in the same manner as in Production Example 3 until the amount reached 6 parts.

The reaction temperature was 80-87°C. The reaction mixture was dissolved in 1065 m of benzene and 266.3 parts of cyclohexane, neutralized with 20% aqueous sodium hydroxide solution, and then dissolved in 20% NaC.
1 Wash three times with 400 parts of aqueous solution. The solvent was distilled off under reduced pressure to obtain 743.1 parts of a pale yellow liquid. This material has the following properties.

Specific gravity (25°C) 1.102 Viscosity (25°C) 419.2 CPS saponification 420.
9 mgKOH/g acid value 0.04 mgKOH
/g Refractive index (206C) 1.4925 Production example 5゜ Tricyclodecane dimethylol 1 obtained in the same manner as synthesis example 1 except that the amount of nibucilone caprolactone used was changed
502.8 parts of an adduct of 4 moles of nibsilone caprolactone and 13 parts of acrylic acid were placed in the same reactor as in Production Example 3.
3.2 parts of sulfuric acid, 4.0 parts of sulfuric acid, 1 part of phenothiazine, 384 parts of benzene, and 96 parts of cyclohexane were charged, heated, and the reaction was carried out in the same manner as in Production Example 3 until the amount of water produced became 27.7 parts. The reaction temperature was 80-88°C. The reaction mixture was dissolved in 720 parts of benzene and 180 parts of cyclohexane, neutralized with 20% aqueous sodium hydroxide solution, and then dissolved in 20% NaCl.
Wash three times with 400 parts of aqueous solution. The solvent was distilled off under reduced pressure to obtain 510.9 parts of a pale yellow liquid.

This material has the following properties.

Specific gravity (25°C) 1.0985 Viscosity (25°G) 561.3 CPS saponification value
441.3 mgKOH/g acid value 0.02
mgKOH/g Refractive index (20'C) 1.4879 [Example of resin composition] Example 1゜40 parts of polyurethane acrylate (A) obtained in Production Example 2, diacrylic ester (B) obtained in Production Example 4 ) 25 copies,
Dicyclopentadieneoxyethyl acrylate (manufactured by Hitachi Chemical Co., Ltd., FA-512A) (C) 35 parts and 1
-Hydroxycyclohexylphenylketone (manufactured by Ciba Kaigy Co., Ltd., Irgacure 184) (D)
Resin composition A was prepared by mixing 5 parts of methylhydroquinone and 0.01 part of methylhydroquinone. Table 1 shows the properties of the resin composition and its cured product.

Example 2゜10 parts of polyurethane acrylate (A) obtained in Production Example 1, 40 parts of polyurethane acrylate (A) obtained in Production Example 2
parts, 25 parts of diacrylic ester (B) obtained in Production Example 3, hydrogenated dicyclopentadiene acrylate (Hitachi Chemical Co., Ltd.
Co., Ltd., FA-513A) (C) 25 parts, benzyl dimethyl ketal (Ciba Geigy Co., Ltd., Irgacure 651) (D) 3 parts, and 0.01 part of methylhydroquinone were mixed to form a resin composition. Product B was prepared. The characteristics of the resin composition and its cured product will be shown first.

Example 3゜35 parts of polyurethane acrylate (A) obtained in Production Example 2, 40 parts of cyacrylic acid ester (B) obtained in Production Example 5, phenyloxyethyl acrylate (manufactured by Kyoeisha Yushi Co., Ltd., PO- A) (C) 10 parts, dicyclopentadieneoxyethyl acrylate (manufactured by Hitachi Chemical Co., Ltd., F
Resin composition C was prepared by mixing 15 parts of A-512A) (C), 3 parts of benzyl dimethyl ketal (D), and 0.01 part of methyl/hydroquinone. Table 1 shows the properties of the resin composition and cured product.

Example 4゜10 parts of polyurethane acrylate (A) obtained in Production Example 1, 35 parts of polyurethane acrylate (A) obtained in Production Example 2
part, 25 parts of diacrylic ester (B) obtained in Production Example 3, 20 parts of hydrogenated dicyclopentadiene acrylate (C), to part of N-vinylpyrrolidone (c) and 3 parts of benzyl dimethyl ketal (D), methyl・Idoquinone 0.
01 parts were mixed to prepare a resin composition Dt-. Table 1 shows the properties of the resin composition and cured product.

Example 5゜40 parts of polyurethane acrylate (A) obtained in Production Example 2, 15 parts of diacrylic acid ester (B) obtained in Production Example 4,
10 m of diacrylic ester (B) obtained in Production Example 5, 15 parts of hydrogenated dicyclopentadiene acrylate (C), N
A resin composition E was prepared by mixing lo parts of vinylpyrrolidone (C), 10 parts of tetrahydrofurfuryl acrylate (C), 3 parts of benzyl dimethyl ketal (D), and 0.01 part of methylhydroquinone. Table 1 shows the properties of the resin composition and cured product.

Comparative Example For comparison purposes, DeSot was used as a UV curable top coating composition for optical fibers.

DeSoto9 commercially available from Chemica1
50X042 was designated as resin composition F.

Table 1 shows the properties of the resin composition and its cured product.

Table 1 In Table 1 above, measurements of [Shore hardness D]: compositions A, B, C, D, E and F were prepared using a high-pressure mercury lamp (lamp (lamp output 2 k)).
W) was irradiated at a position 8 cnL below the light source arranged in parallel (conveyor speed 5 m/min) to a thickness of 250 μm.
A sheet was prepared and measurements were made using this sheet. The measurement method is J
It was carried out according to the method of IS-22246.

[Breaking strength: kg/mJ Breaking elongation: %, Young's modulus:
kg/md ) measurement: The test was carried out using a sheet produced under the same conditions as those used for the above Shore hardness measurement.

Measurement of [Water Absorption]: A test piece was prepared under the same conditions as those used for measuring the crease hardness A above. Using this, it was immersed in pure water at 20° C. for 24 hours, and its weight before and after the test was measured, and the increase in weight due to water absorption was expressed as chi.

Example 6 A base material for optical glass fiber was heated to about 2000°C, and
It was spun into an optical glass fiber with an outer diameter of 125 microns at a speed of m/sec. In the next successive step, by die coating method, a primary coating agent (a mixture of 50% polyurethane acrylate, 45% monoacrylate of ε-caprolact/1 mole adduct of tetrahydrofurfuryl alcohol and 5% photoinitiator) was coated and cured by UV irradiation. Next, the resulting primary-coated optical glass fibers were top-coated with resin compositions A to E of Examples 1 to 5, respectively, and then cured by irradiation with ultraviolet rays from a high-pressure mercury lamp. In the obtained coated optical glass fiber, no change in transmission loss was observed up to -60°C, even when top coated with any of resin compositions A to E.

(Effects of the Invention) The resin composition and coating agent of the present invention have a fast curing speed and are low in skin toxicity (Primary Ir1tat-io
n Index ) is small, has an appropriate viscosity, and
The resin coating obtained by curing has high elongation, low water absorption, appropriate Young's modulus and hardness, and is particularly suitable for top coating of optical glass fibers for light transmission.

Patent Applicant: Nippon Kayaku Co., Ltd. Procedural Amendment Written on January 21, 1985 Michibe Uga, Commissioner of the Patent Office 1, Indication of the Case 1985 Patent Application No. 195724 2, Name of the Invention Resin Composition and Coating agent 3, relationship with the amended case Patent applicant: 11-2 Fujimi-chome, Chiyoda-ku, Tokyo (40B)
Nippon Kayaku Co., Ltd. Representative Director and President Tsunekazu Sakano 4, Agent Fujimi-11-2-6, Chiyoda-ku, Tokyo No number of inventions increased due to amendment 7, Subject of amendment (1) Patent law in the application Grasping the indication of a patent application pursuant to the proviso to Article 38 8. Contents of amendment (1) Add the statement ``Patent application pursuant to the proviso to Article 38 of the Patent Act'' to the application.

(2) Between the title of the invention column and the inventor column in the application, write “
The number of inventions stated in the scope of claims: 2" is added.

that's all

Claims (2)

[Claims] (1) Polyurethane (meth)acrylate (A), general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, m and The average value of n is a number from 0 to 5, the average total value of m+n is a number from 1 to 10, and R is H or OH_3. , monoethylenically unsaturated monomer (C
) and a photopolymerization initiator (D) as an optional component. (2) Polyurethane (meth)acrylate (A), general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, m and The average value of n is a number from 0 to 5, the average total value of m+n is a number from 1 to 10, and R is H or CH_3. A coating agent for optical glass fibers, comprising a monoethylenically unsaturated monomer (C) and a photopolymerization initiator (D).