Novel silicon-urethane (meth) acrylate, and resin composition and coating material comprising same

Abstract

A silicon-urethane (meth) acrylate which is a reaction product of an isocyanato-alkylsilane compound represented by the following general formula: ##STR1## wherein R.sub.1 represents an alkylene group having 2 to 5 carbon atoms, R.sub.2 represents an alkyl group having 1 to 5 carbon atoms or alkoxy group having 1 to 5 carbon atoms, and R.sub.3 and R.sub.4 each represents an alkyl group having 1 to 5 carbon atoms, and a hydroxyl group-containing ester of (meth) acrylic acid, a resin composition and a coating material for optical glass fiber comprising said silicon-urethane (meth) acrylate.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a novel silicon-urethane (meth)acrylate, as well as to a resin composition and a coating material for optical fiber comprising said silicon-urethane (meth)acrylate which is useful particularly as an ultraviolet-curable coating material to be applied to glass surface of optical fiber to protect it.

2. Description of the Prior Art

Since optical fiber has a high information-transmitting performance and it is relatively insusceptible to the external interference, its use has markedly increased in the later several years particularly in the field of communications. Optical fibers are generally made of glass, because they are used in the field of communications. However, glass fiber is fragile in its nature and can be chemically deteriorated by steam, so that it is readily breakable and difficult to handle. Accordingly, it has hitherto been conventional to coat glass fibers with a resin. As the resin for coating glass fibers, epoxy resin, urethane resin and the like have so far been used. However, these resins are disadvantageous in that they are inferior in productivity because their cure takes a long period of time and they are poor in flexibility so that transmitting performance of glass fiber can be deteriorated by lateral pressure. With the aim of overcoming the above-mentioned disadvantages, ultraviolet-curable compositions comprising urethane acrylate have energetically been studied recently, and ultraviolet-curable composition for optical glass fiber and a method for forming its coating film have been proposed in, for example, Japanese Patent Kokai (Laid-Open) No. 223,638/83 and EP 111,280.

Further, with the aim of improving the adhesion to glass, an ultraviolet-curable coating material for optical glass has been proposed in EP 149,741.

According to EP 149,741, polyalkoxysilane having one amino group or mercapto group is added to improve adhesion to glass. However, this composition has a problem that viscosity of the liquid can increase and gelation can take place, though the composition is excellent in adhesion to glass.

SUMMARY OF THE INVENTION

The present inventors conducted earnest studies with the aim of solving the above-mentioned problems. As the result, they succeeded in providing a resin composition excellent in adhesive property to glass, good in the stability as a composition and particularly suitable for use as a coating material for optical glass fiber for optical transmission. Based on this success, the present invention was accomplished. Thus, the present invention relates to:

(1) a silicon-urethane (meth)acrylate which is a reaction product of an isocyanato-alkylsilane compound represented by the following general formula (A): ##STR2## wherein R.sub.1 represents an alkylene group having 2 to 5 carbon atoms and preferably 3 carbon atoms, R.sub.2 represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms and preferably an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, and R.sub.3 and R.sub.4 each represents an alkyl group having 1 to 5 carbon atoms and preferably 1 to 3 carbon atoms, and a hydroxyl group-containing ester of (meth)acrylic acid;

(2) a resin composition comprising a silicon-urethane (meth)acrylate which is a reaction product of a compound represented by the above-mentioned general formula (A) and a hydroxyl group-containing ester of (meth)acrylic acid; and

(3) a coating material for optical glass fiber containing a silicon-urethane (meth)acrylate which is a reaction product of a compound represented by the general formula (A) and a hydroxyl group-containing ester of (meth)acrylic acid.

As used in the present invention, the term "(meth)acrylic acid" means "acrylic acid or methacrylic acid", and the term "(meth)acrylate" means "acrylate or methacrylate".

DETAILED DESCRIPTION OF THE INVENTION

In the present invention, silicon-urethane (meth)acrylate is used.

This novel silicon-urethane (meth)acrylate can be produced by reacting the compound represented by general formula (A) with a hydroxyl group-containing ester of (meth)acrylic acid.

Among the compounds represented by general formula (A), particularly preferably are .gamma.-isocyanatopropyl-triethoxysilane, .gamma.-isocyanatopropyl-methyl-diethoxysilane and .gamma.-isocyanatopropylmethyl-dimethoxysilane.

Examples of the hydroxyl group-containing ester of (meth)acrylic acid [hereinafter, referred to as "compound (I)"] used in the present invention include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, .epsilon.-caprolactone-.beta.-hydroxyalkyl (meth)acrylate adduct (PLACCEL FA-1, PLACCEL FA-2, PLACCEL FM-1, etc., manufactured by DAICEL Kagaku Kogyo K.K.), polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, hydroxybutyl (meth)acrylate, and the like. Among them, hydroxyethyl acrylate, hydroxypropyl acrylate and the like are particularly preferable. The temperature at which the compound represented by general formula (A) is reacted with compound (I) is preferably in the range from room temperature to 100.degree. C., and particularly in the range from 50.degree. C. to 90.degree. C. Per one mole of the compound represented by general formula (A), compound (I) can be used in an amount of 1 to 2 moles and preferably 1 to 1.5 moles. This reaction can be carried out in the presence of a known catalyst such as tertiary amine, dibutyltin dilaurate, dioctyltin dilaurate and the like in order to accelerate the reaction between isocyanate group and hydroxyl group. Preferably, these catalysts are used in an amount of 10 ppm to 300 ppm in the reaction mixture. Further, it is preferable to add 50 ppm to 2,000 ppm of a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, methylhydroquinone, p-benzoquinone, phenothiazine and the like to the reaction mixture in order to prevent the gelformation caused by radical polymerization which can take place in the course of reaction. The silicon-urethane (meth)acrylate is used preferably in an amount of 0.5 to 10% by weight and particularly 1 to 5% by weight based on the resin composition or coating material. The resin composition or coating material may comprise various known ethylenically unsaturated compounds as a component other than the silicon-urethane (meth)acrylate. Concrete examples of said ethylenically unsaturated compound include polyurethane (meth)acrylates such as polyurethane (meth)acrylate of polyether polyol having ether residue in its molecule, polyurethane (meth)acrylate of carbonate polyol having carbonate residue, polyurethane (meth)acrylate of polyester polyol having ester residue, polyurethane (meth)acrylate having both ether residue and ester residue, and the like; epoxy (meth)acrylates such as (meth)acrylate of Bisphenol A type epoxy resin, (meth)acrylate of Bisphenol F type epoxy resin, (meth)acrylate of urethane-modified epoxy resin of Bisphenol A, and the like; polyester (meth)acrylates such as (meth)acrylate of polyester-diol composed of a diol compound (e.g. ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,5-pentanediol, 1,6-hexanediol and the like) and a dibasic acid (e.g. succinic acid, adipic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid and the like), (meth)acrylate of lactone-modified polyester diol composed of a diol compound, a dibasic acid and .epsilon.-caprolactone, and the like; polycarbonate (meth)acrylates such as (meth)acrylate of polycarbonate diol having 1,6-hexanediol as its diol component, and the like; as well as phenyloxy polyethoxy (meth)acrylate, phenyloxy polypropoxy (meth)acrylate, nonylphenyloxy polyethoxy (meth)acrylate, nonylphenyloxy polyporpoxy (meth)acrylate, polypropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)acrylate of tetrahydrofurfuryl alcohol-.epsilon.-caprolactone adduct (e.g. KAYARAD TC-110S, TC-120, etc. manufactured by Nippon Kayaku K.K.), (meth)acrylate of tetrahydrofurfuryl alcohol-propylene oxide adduct, .epsilon.-caprolactone-.beta.-hydroxyethyl (meth)acrylate adduct (PLACCEL FA-2, FM-2, etc., manufactured by DAICEL Kagaku Kogyo K.K.), and (meth)acrylic esters represented by the following general formula (B): ##STR3## wherein R.sub.5 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms such as a nonyl group; R.sub.6 and R.sub.7 each represents hydrogen atom or a methyl group; mean value of m is 1 to 5; and mean value of n is 1 to 10.

Among them, particularly preferable ethylenically unsaturated compounds are polyurethane acrylate of polyether polyol, polyurethane acrylate of polycarbonate polyol, polyurethane acrylate of polyester polyol, nonylphenyloxy polyethoxy acrylate, nonylphenyloxy polypropoxy acrylate, acrylate of tetrahydrofurfuryl alcohol-.epsilon.-caprolactone adduct, acrylate of nonylphenyloxy polyethoxy alcohol-.epsilon.-caprolactone adduct, .epsilon.-caprolactone-.beta.-hydroxyethyl acrylate adduct, (meth)acrylic esters represented by the above-mentioned general formula (B), and the like, for example. The above-mentioned ethylenically unsaturated compounds may be used either in the form of single compound or in the form of a mixture of two or more compounds having an arbitrary mixing ratio. Said ethylenically unsaturated compound is used preferably in an amount ranging from 80% to 99.4% by weight and particularly in an amount ranging from 90% to 97% by weight, based on the resin composition or coating material. These ethylenically unsaturated compounds are synthesizable according to the known method. Otherwise, they are readily available commercially. The resin composition or coating material of the present invention can be cured according to the known method. For example, they can be cured by means of ultraviolet ray. In the case of ultraviolet cure, a photopolymerization initiator must be used. As said photopolymerization initiator, any of the known photopolymerization initiators may be used, so long as it has a high storage stability after being compounded into the composition. Examples of such photopolymerization initiator include benzoin alkyl ethers such as benzoin ethyl ether, benzoin isobutyl ether, benzin isopropyl ether and the like; acetophenones such as 2,2-diethoxyacetophenone, 4'-phenoxy-2,2-dichloroacetophenone and the like; propiophenones such as 2-hydroxy-2-methylpropiophenone, 4'-isopropyl-2-hydroxy-2-methylpropiophenone, 4'-dodecyl-2-hydroxy-2 -methylpropiophenone and the like; benzyl dimethyl ketal; 1-hydroxycyclohexyl phenyl ketone; anthraquinones such as 2-ethylanthraquinone, 2-chloroanthraquinone and the like; thioxanthones; and the like. Among them, particularly preferable are benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, and the like. These photopolymerization initiators may be used either in the form of single substance or in the form of a mixture of two or more members having an arbitrary mixing ratio. The photopolymerization initiator is used usually in an amount of 0.1 to 10% by weight and preferably 1 to 5% by weight, based on the weight of coating material.

If desired, modifying resin and various additives may be added to the resin composition and coating material of the present invention. As said modifying resin, epoxy resin, polyurethane, polybutadiene, polyether, polyamide-imide, silicone resin, phenolic resin and the like can be referred to. The modifying resin is used preferably in an amount ranging from 0% to 10% by weight and particularly in an amount ranging from 0% to 5% by weight, based on the resin composition or coating material.

As said additives, polymerization inhibitor (e.g. methoquinone, methylhydroquinone and the like), surfactant (e.g. SH-3749 manufactured by Toray Silicone K.K.), and the like can be referred to. Preferably, the polymerization inhibitor is used in an amount ranging from 0% to 1% by weight and the surfactant is used in an amount ranging from 0% to 3% by weight, both based on the weight of resin composition or coating material.

As the coating process for coating optical glass fiber with the coating material of the invention for glass fiber, dies coating process is preferable.

In coating a glass fiber with the coating material of the present invention for optical glass fiber, a base material of optical glass is linearly drawn at a speed of, for example, 1 to 5 m/second and it is coated with the coating material of the present invention, after which it is cured by ultraviolet irradiation and then coated with a top coating material.

The coating material of the present invention can easily be cured by ultraviolet irradiation. The cure of the coating material of the present invention by ultraviolet irradiation can be carried out in the usual way. For example, it is carried out by irradiating ultraviolet ray by means of low pressure mercury lamp, high pressure mercury lamp or xenon lamp.

The resin composition of the present invention is useful as a coating material for optical glass fiber. Further, it is also usable as a coating material for glass, an adhesive and a coating material for ceramics.

Next, the present invention will be illustrated more concretely with reference to the following non-limitative synthesis examples and examples. In the examples, "parts" means "parts by weight".

Syntheses of Ethylenically Unsaturated Compounds

Synthesis Example 1 (Polyurethane acrylate)

Into a 2 liter reactor equipped with a stirrer, a thermostat, a thermometer and a condenser were charged 500 parts of polycarbonate diol (DN-982 manufactured by Nippon Polyurethane K.K., molecular weight 2,000, hydroxyl number 56.0 mg KOH/g) and 83.3 parts of isophorone diisocyanate. After heating them to 80.degree. C., they were reacted at this temperature for 10 hours, and the reaction mixture was cooled to 60.degree. C. Then, 210 parts of .epsilon.-caprolactone-.beta.-hydroxyethyl acrylate adduct (PLACCEL FA-2, manufactured by DAICEL Kagaku Kogyo K.K.), 0.4 part of methoquinone and 0.15 part of di-n-butyltin dilaurate were added, and the resulting mixture was heated and reacted at a temperature of 75.degree. C. to 80.degree. C. The reaction was continued until the concentration of free isocyanate group reached about 0.1% or below to indicate the completion of the reaction. The product had the following property.

Viscosity: 192 Poise (60.degree. C.)

Syntheses of Silicon-Urethane (Meth)acrylates

EXAMPLE 1

Into a one liter reactor equipped with a stirrer, a thermostat, a thermometer and a condenser were charged 247 parts of .gamma.-isocyanatopropyl-triethoxysilane (YH-9030, manufactured by Nippon Unicar Co., Ltd., NCO content 17.0%), 115 parts of 2-hydroxyethyl acrylate and 0.36 part of methoquinone. After heating the mixture to 80.degree. C., it was reacted at that temperature until the concentration of free isocyanate group reached about 0.1% or below to indicate the completion of the reaction. Properties of the product were as follows.

Viscosity (25.degree. C.): 62 cps Acid value: 0.01 mg KOH/g

As measured by high resolution nuclear magnetic resonance (NMR), the frequency of the absorption of the product thus obtained was as follows:

______________________________________Results of NMR Measurement Frequency of Frequency ofNo. absorption (Hz) No. absorption (Hz)______________________________________1 2492.187 9 939.4532 2347.656 10 878.9063 1968.750 11 654.2964 1927.734 12 351.5625 1191.406 13 275.3906 1160.156 14 115.2347 1128.906 15 0.0008 945.312______________________________________

In the above-mentioned NMR measurement, tetramethylsilane was used as the standard substance. The measurement was conducted first by .sup.1 H and .sup.13 C-H coupling and finally by .sup.13 C-D coupling to obtain identification results.

EXAMPLE 2

Into the same reactor as in Example 1 were charged 247 parts of .gamma.-isocyanatopropyl-triethoxysilane, 134 parts of 2-hydroxypropyl acrylate and 0.38 part of methoquinone. The mixture was heated to 80.degree. C. and reacted at this temperature in the same manner as in Example 1 until the completion of the reaction. Properties of the product were as follows.

Viscosity (25.degree. C.): 67 cps Acid value: 0.02 mg KOH/g ______________________________________Results of NMR measurement Frequency of Frequency ofNo. absorption (Hz) No. absorption (Hz)______________________________________1 2492.187 12 1027.3432 2343.750 13 1000.0003 1968.750 14 878.9064 1964.843 15 654.2965 1933.593 16 349.6096 1927.734 17 291.0157 1193.359 18 275.3908 1160.156 19 253.9069 1128.906 20 246.09310 1046.874 21 115.23411 1037.109 22 0.000______________________________________

EXAMPLE 3

Into the same reactor as in Example 1 were charged 247 parts of .gamma.-isocyanatopropyl-triethoxysilane, 134 parts of 2-hydroxyethyl methacrylate and 0.19 part of methoquinone. The mixture was reacted in the same manner as in Example 1 until the completion of the reaction. Properties of the product were as follows.

Viscosity (25.degree. C.): 60 cps Acid value: 0.01 mg KOH/g ______________________________________Results of NMR measurement Frequency of Frequency ofNo. absorption (Hz) No. absorption (Hz)______________________________________1 2511.718 10 939.4532 2349.609 11 916.0153 2046.875 12 878.9064 1890.625 13 656.2505 1195.312 14 351.5626 1164.062 15 275.3907 1130.859 16 117.1878 998.046 17 0.0009 949.218______________________________________

EXAMPLE 4

Into the same reactor as in Example 1 were charged 247 parts of .gamma.-isocyanatopropyl-triethoxysilane, 354 parts of .epsilon.-caprolactone-.beta.-hydroxyethyl acrylate adduct (PLACCEL FA-2, manufactured by DAICEL Kagaku Kogyo K.K.) and 0.3 part of methoquinone. In the same manner as in Example 1, the mixture was reacted until the completion of the reaction. Properties of the product were as shown below.

Viscosity (25.degree. C.): 212 cps Acid value: 0.03 mg KOH/g ______________________________________Results of NMR measurement Frequency of Frequency ofNo. absorption (Hz) No. absorption (Hz)______________________________________1 2605.468 13 876.9532 2490.234 14 654.2963 2357.421 15 511.7184 2349.609 16 433.5935 1972.656 17 427.7346 1925.781 18 384.7657 1199.218 19 369.1408 1166.615 20 351.5629 1134.765 21 275.39610 962.890 22 115.23411 945.312 23 0.00012 937.500______________________________________

EXAMPLE 5

Into the same reactor as in Example 1 were charged 644.8 parts of .gamma.-isocyanatopropyl-methyl-diethoxysilane, 355.2 parts of 2-hydroxyethyl acrylate and 1.0 part of methoquinone. In the same manner as in Example 1, the mixture was reacted until completion of the reaction. Properties of the product were as shown below.

Viscosity (25.degree. C.): 99 cps Acid value: 0.01 mg KOH/g ______________________________________Results of NMR measurement Frequency of Frequency ofNo. absorption (Hz) No. absorption (Hz)______________________________________1 2492.187 14 910.1562 2357.421 15 875.0003 2345.703 16 656.2504 1970.703 17 353.5155 1927.734 18 306.6406 1195.312 19 277.3437 1162.109 20 253.9068 1130.859 21 248.0469 1070.312 22 222.65610 1041.015 23 173.82811 1029.296 24 169.92112 1000.000 25 -72.26513 978.515______________________________________

EXAMPLE 6

Into the same reactor as in Example 1 were charged 618.3 parts of .gamma.-isocyanatopropyl-methyl-diethoxysilane, 381.7 parts of 2-hydroxypropyl acrylate and 1.0 part of methoquinone. In the same manner as in Example 1, the mixture was reacted until the completion of the reaction. Properties of the product were as shown below.

Viscosity (25.degree. C.): 100 cps Acid value: 0.02 mg KOH/g ______________________________________Results of NMR measurement Frequency of Frequency ofNo. absorption (Hz) No. absorption (Hz)______________________________________1 2498.046 11 939.4532 2359.375 12 912.1093 2349.609 13 875.0004 1970.703 14 656.2505 1929.687 15 351.5626 1193.359 16 277.3437 1162.109 17 220.7038 1128.906 18 167.9689 986.328 19 0.00010 945.312 20 -74.218______________________________________

EXAMPLE 7

In the same reactor as in Example 1 were charged 618.5 parts of .gamma.-isocyanatopropyl-methyl-diethoxysilane, 381.5 parts of 2-hydroxyethyl methacrylate and 1.0 part of methoquinone. In the same manner as in Example 1, the mixture was reacted until the completion of the reaction. Properties of the product were as shown below.

Viscosity (25.degree. C.): 90 cps Acid value: 0.03 mg KOH/g ______________________________________Results of NMR measurement Frequency of Frequency ofNo. absorption (Hz) No. absorption (Hz)______________________________________1 2607.421 14 656.2502 2603.515 15 511.7183 2492.187 16 484.3754 2355.468 17 431.6405 1972.656 18 425.7816 1923.828 19 382.8127 1193.359 20 369.1408 1160.156 21 351.5629 1128.906 22 275.39010 962.890 23 220.70311 935.546 24 166.01512 931.640 25 -74.21813 873.046______________________________________

EXAMPLE 8

Into the same reactor as in Example 1 were charged 379.9 parts of .gamma.-isocyanatopropyl-methyl-diethoxysilane, 620.1 parts of .epsilon.-caprolactone-.beta.-hydroxyethyl acrylate adduct (prepared by reacting 1 mole of 2-hydroxyethyl acrylate with 2 moles of .epsilon.-caprolactone; PLACCEL FA-2, manufactured by DAICEL Kagaku Kogyo K.K.) and 1.0 part of methoquinone. In the same manner as in Example 1, the mixture was reacted until the completion of the reaction. Properties of the product were as shown below.

Viscosity (25.degree. C.): 245 cps Acid value: 0.01 mg KOH/g ______________________________________Results of NMR measurement Frequency of Frequency ofNo. absorption (Hz) No. absorption (Hz)______________________________________1 2515.625 11 937.5002 2357.421 12 912.1093 2349.609 13 875.0004 2046.875 14 656.2505 1888.671 15 351.5626 1193.359 16 275.3907 1160.156 17 220.7038 1128.906 18 166.0159 986.328 19 0.00010 947.265 20 -76.171______________________________________

EXAMPLE 9

Into the same reactor as in Example 1 were charged 612.6 parts of .gamma.-isocyanatopropyl-methyl-dimethoxysilane, 387.4 parts of 2-hydroxyethyl acrylate and 1.0 part of methoquinone. In the same manner as in Example 1, the mixture was reacted until completion of the reaction. Properties of the product were as shown below.

Viscosity (25.degree. C.): 105 cps Acid value: 0.02 mg KOH/g ______________________________________Results of NMR measurement Frequency of Frequency ofNo. absorption (Hz) No. absorption (Hz)______________________________________1 2492.187 12 976.5622 2343.750 13 779.2963 1968.750 14 753.9064 1925.781 15 656.2505 1193.359 16 349.6096 1160.156 17 304.6877 1128.906 18 251.9538 1068.359 19 244.1409 1039.062 20 164.06210 1027.343 21 154.29611 998.046 22 -89.843______________________________________

Examples of Resin Composition (Coating Material)

EXAMPLE 10

Resin composition A (coating material) was prepared by mixing together 40 parts of the polyurethane acrylate prepared in Synthesis Example 1, 60 parts of acrylic ester of tetrahydrofurfuryl alcohol-.epsilon.-caprolactone adduct (KAYARAD TC-110S, manufactured by Nippon Kayaku K.K.), 2 parts of silicon-urethane acrylate prepared in Example 1, 5 parts of 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba-Geigy Ltd., photopolymerization initiator) and 0.01 part of methylhydroquinone.

Characteristics of the liquid composition and the cured product are summarized in Table 1.

EXAMPLE 11

Resin composition B (coating material) was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was replaced with 3 parts of silicon-urethane acrylate obtained in Example 2. Characteristics of the liquid composition and the cured product are summarized in Table 1.

EXAMPLE 12

Resin composition C (coating material) was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was replaced with 1 part of the silicon-urethane methacrylate obtained in Example 3. Characteristics of the liquid composition and the cured product are summarized in Table 1.

EXAMPLE 13

Resin composition D (coating material) was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was replaced with 2 parts of the silicon-urethane acrylate obtained in Example 4. Characteristics of the liquid composition and the cured product are summarised in Table 1.

EXAMPLE 14

Resin composition E was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was replaced with 2 parts of silicon-urethane acrylate obtained in Example 5. Characteristics of the liquid composition and the cured product are summarized in Table 1.

EXAMPLE 15

Resin composition F was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was replaced with 2 parts of the silicon-urethane acrylate obtained in Example 6. Characteristics of the liquid composition and the cured product are summarized in Table 1.

EXAMPLE 16

Resin composition G was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was replaced with 2 parts of the silicon-urethane methacrylate obtained in Example 7. Characteristics of the liquid composition and the cured product are summarized in Table 1.

EXAMPLE 17

Resin composition H was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was replaced with 2 parts of the silicon-urethane acrylate obtained in Example 8. Characteristics of the liquid composition and the cured product are summarized in Table 1.

EXAMPLE 18

Resin composition I was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was replaced with 2 parts of the silicon-urethane acrylate obtained in Example 9. Characteristics of the liquid composition and the cured product are summarized in Table 1.

Comparative Example 1

Resin composition J (coating material) was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was not used. Characteristics of the liquid composition and the cured product are summarized in Table 1.

Comparative Example 2

Resin composition K (coating material) was prepared according to the formulation of Example 10, except that 2 parts of silicon-urethane acrylate used in the composition of Example 10 was replaced with 2 parts of aminopropyl-trimethoxysilane. Characteristics of the liquid composition and the cured product are summarized in Table 1.

TABLE 1__________________________________________________________________________ Resin composition A B C D E F G H I J K__________________________________________________________________________Adhesive strength 4.0 3.5 3.8 4.5 3.1 2.9 2.8 3.5 3.2 0.9 3.2to glass (g/cm)Adhesive strength 4.1 3.4 3.9 4.6 3.0 2.9 2.9 3.5 3.1 0.9 3.3to glass (g/cm)(after moistureresistance test)Stability of No No No No No No No No No No Gelationliquid composition abnor- abnor- abnor- abnor- abnor- abnor- abnor- abnor- abnor- abnor- mality mality mality mality mality mality mality mality mality mality__________________________________________________________________________ Notes to Table 1: Measurement of adhesive strength to glass (g/cm): Each of the composition A, B, C, D, E, F, G, H, I, J and K was coated on a glass plate and irradiated with a light source (a parallel arrangement of high pressure mercury lamps, output 2 KW/one lamp) by running the glass plate at a conveyer speed of 20 m/minute underneath the light source while keeping a distance of 8 cm from the light source. Thus, a cured film having a thickness of 250 .mu.m was prepared. The cured film on the glass plate wa cut into pieces having a width of 1 cm, and they were used for the measurement. Measurement of adhesive strength to glass (g/cm) after moisture resistanc test: A cured film on the glass plate was prepared in the same manner as in the abovementioned measurement of adhesive strength (g/cm). After allowing the film to stand for 24 hours at a temperature of 25.degree. C. at a humidity of 95% RH, it was used for the measurement: Stability of liquid composition: A 100 g portion of each composition was taken into a browncolored polyethylene bottle and allowed to stand for on month at a temperature of 60.degree. C., after which its state was visually examined.

EXAMPLE 19

A base material of optical fiber was heated to about 2,000.degree. C. and spun into an optical fiber having an outer diameter of 125 microns at a speed of 5 m/second. In the subsequent continuous steps, the glass fiber was coated with each of the resin compositions A to I of Examples 10 to 18 according to the dies coating process and cured by ultraviolet irradiation. Then, the primarily coated optical glass fiber thus obtained was top-coated (for example, with Desolite 950Y-100 manufactured by DeSoTo Ltd.) and cured by ultraviolet irradiation. The coated optical glass fiber thus obtained showed no change in the transmission loss down to the low temperature of -60.degree. C., whichever of resin compositions A to I was used for the coating.

The resin composition of the present invention is excellent in adhesion to glass and stability in the state of liquid composition, and therefore it is particularly useful as a coating material for optical glass fibers used for optical transmissions.

Claims

1. A silicon-urethane (meth)acrylate which is a reaction product of an isocyanato-alkylsilane compound represented by the following general formula: ##STR4## wherein R.sub.1 represents an alkylene group having 2 to 5 carbon atoms, R.sub.2 represents an alkyl group having 1 to 5 carbon atoms or alkoxy group having 1 to 5 carbon atoms, and R.sub.3 and R.sub.4 each represents an alkyl group having 1 to 5 carbon atoms, and a hydroxyl group-containing ester of (meth)acrylic acid.

2. A silicon-urethane (meth)acrylate according to claim 1, wherein R.sub.1 represents an alkylene group having 3 carbon atoms, R.sub.2 represents an alkyl group having 1 to 3 carbon atoms or alkoxy group having 1 to 3 carbon atoms, and R.sub.3 and R.sub.4 each represents an alkyl group having 1 to 3 carbon atoms.

3. A silicon-urethane (meth)acrylate according to claim 1, wherein said isocyanato-alkylsilane compound is .gamma.-isocyanatopropyl-triethoxysilane, .gamma.-isocyanatopropyl-methyl-diethoxysilane or .gamma.-isocyanatopropyl-methyl-dimethoxysilane.

4. A silicon-urethane (meth)acrylate according to claim 1, 2 or 3, wherein said hydroxyl group-containing ester of (meth)acrylic acid is a compound selected from the group consisting of hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, .epsilon.-caprolactone-.beta.-hydroxyalkyl (meth)acrylate adduct, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate and hydroxybutyl (meth)acrylate.

5. A composition comprising (1) 0.5% to 10% by weight of a silicon-urethane (meth)acrylate which is a reaction product of an isocyanato-alkylsilane compound represented by the following general formula: ##STR5## wherein R.sub.1 represents an alkylene group having 2 to 5 carbon atoms, R.sub.2 represents an alkyl group having 1 to 5 carbon atoms or alkoxy groups having 1 to 5 carbon atoms, and R.sub.3 and R.sub.4 each represents an alkyl group having 1 to 5 carbon atoms, and a hydroxyl group-containing ester of (meth)acrylic acid, (2) 80% to 99.4% by weight of an ethylenically unsaturated compound, wherein said ethylenically unsaturated compound is at least one compound selected from the group consisting of polyurethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, polycarbonate (meth)acrylate, phenyloxypolyethoxy (meth)acrylate, phenyloxypolypropoxy (meth)acrylate, nonylphenyloxypolyethoxy (meth)acrylate, nonylphenyloxypolypropoxy (meth)acrylate, polypropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)acrylate of tetrahydrofurfuryl alcohol-.epsilon.-caprolactone adduct, (meth)acrylate of tetrahydrofurfuryl alcohol-propylene oxide adduct, .epsilon.-caprolactone-.beta.-hydroxyethyl (meth)acrylate adduct, and (meth)acrylic esters represented by the following general formula: ##STR6## wherein R.sub.5 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R.sub.6 and R.sub.7 each represents a hydrogen atom or a methyl group, mean value of m is 1 to 5, and mean value of n is 1 to 10, and (3) 0.1% to 10% by weight of a photopolymerization initiator.

6. A composition according to claim 5, wherein said hydroxyl group-containing ester of (meth)acrylic acid is a compound selected from the group consisting of hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, .epsilon.-caprolactone-.beta.-hydroxyalkyl (meth)acrylate adduct, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate and hydroxybutyl (meth)acrylate.

7. An optical glass fiber having a photopolymerized coating of the composition of claim 5.

8. An optical glass fiber having a photopolymerized coating of the composition of claim 6.

9. A silicon-urethane (meth)acrylate according to claim 1 wherein said reaction product is formed in the presence of a catalyst.

10. A silicon-urethane (meth)acrylate according to claim 1 wherein said reaction product is prepared in the presence of a polymerization inhibitor.

11. A silicon-urethane (meth)acrylate according to claim 10 wherein said polymerization inhibitor is selected from the group consisting of hydroquinone, hydroquinone monomethyl ether, methylhydroquinone, p-benzoquinone, and phenothiazine.

12. A composition according to claim 5 which contains a polymerization inhibitor.

13. A composition according to claim 5 wherein said reaction product is prepared in the presence of a polymerization inhibitor.

14. A composition according to claim 13 wherein said polymerization inhibitor is selected from the group consisting of hydroquinone, hydroquinone monomethyl ether, methylhydroquinone, p-benzoquinone, and phenothiazine.