JPH0730141B2 - UV curable liquid composition - Google Patents

Description

TECHNICAL FIELD The present invention has a high Young's modulus and a high extensibility, and provides a cured product having a high Young's modulus even at high temperatures, and is suitable as a coating material for optical communication fibers. The present invention relates to an ultraviolet curable liquid composition used in.

2. Description of the Related Art Conventionally, various optical fibers for optical communication such as quartz, multi-component glass, and plastic have been known as fiber for optical communication. Quartz-based glass fibers have been widely put into practical use because of their good loss, non-inductivity, heat resistance, transmission capacity, and the like.

Although this silica-based glass fiber for optical communication has the above-mentioned characteristics, it is extremely thin and easily changes over time.Therefore, the fiber is pre-coated with a relatively soft primary or buffer coating in advance and then a secondary coating with a harder top coating. The coating is performed to protect the primary coating layer, and as the coating material for this secondary coating,
Various radiation-curable resin compositions containing a urethane prepolymer having both ends terminated with an ethylenically unsaturated group as a main component and containing a monomer compound and a radiation polymerization initiator have been used.

Such a coating material for glass fiber for optical communication protects the fiber from external factors, has a high Young's modulus after curing and retains a high Young's modulus even at high temperature, and has high elongation, high strength, and low water absorption rate. It is required to have properties such as hydrolysis resistance. However, none of the various radiation-curable resin compositions conventionally used as coating materials for glass fibers for optical communication have the above-mentioned characteristics in a well-balanced manner, and it cannot be said that they are satisfactory as coating materials. In particular, among the above properties, Young's modulus, which is a mechanical property, and extensibility have a contradictory relationship,
It is difficult to maintain both properties in good condition because improvement in one is impaired in the other, and it has been difficult to obtain a coating material having high Young's modulus and high elongation.

The present invention has been made in view of the above circumstances, and provides a cured product that has the properties of high Young's modulus and high elongation, and has a high Young's modulus even at high temperatures, and is suitable as a coating material for glass fiber for optical communication. It is an object to provide an ultraviolet curable liquid composition.

Means and Actions for Solving Problems The present inventors have conducted extensive studies to achieve the above object, and as a result, (1) have polytetramethylene glycol, an organic diisocyanate, a hydroxy group and an ethylenically unsaturated group. A urethane compound obtained by reacting a compound, a diol represented by the formula HO-R-OH (where R is a divalent hydrocarbon group), an organic diisocyanate, a hydroxy group and an ethylenically unsaturated group A mixture with a urethane compound obtained by reacting with, or
Polytetramethylene glycol and formula HO-R-OH (however, R
Is a divalent hydrocarbon group), a mixed reaction product obtained by reacting an organic diisocyanate with a compound having a hydroxy group and an ethylenically unsaturated group, (2) ethylenically unsaturated When an ultraviolet curable liquid composition containing a group-containing monomer and (3) a photopolymerization initiator is cured, it has good elongation, tensile strength and modulus at room temperature. Its modulus is well maintained even at high temperature without lowering, and it is excellent in both properties of Young's modulus and extensibility, which are originally contradictory to each other,
Therefore, they have found that they are optimal as coating materials for glass fibers for optical communication, and have completed the present invention.

Hereinafter, the present invention will be described in more detail.

The first essential component of the ultraviolet curable liquid composition according to the present invention is represented by (a) a urethane compound of polytetramethylene glycol and the formula HO-R-OH (where R is a divalent hydrocarbon group). A urethane obtained by simultaneously urethanizing a mixture of a diol with a urethane compound or (b) a polytetramethylene glycol and a diol represented by the formula HO-R-OH (where R is a divalent hydrocarbon group). It is a mixed reaction product of compounds.

First, in the mixture of (a), the urethane compound of polytetramethylene glycol is obtained by reacting polytetramethylene glycol, an organic diisocyanate, and a compound having a hydroxy group and an ethylenically unsaturated group, and an alkyl diol. The urethane compound is obtained by reacting an alkyl diol with an organic diisocyanate and a compound having a hydroxy group and an ethylenically unsaturated group.

Here, polytetramethylene glycol represented by the following general formula _{(I) HOCH 2 CH 2 CH} 2 CH 2 O n H ... (I) ( where, n wherein the average molecular weight of the polytetramethylene glycol 1000-5000 Which is an integer of 1.) in the present invention, it is preferable to use the polytetramethylene glycol of the formula (I) having an average molecular weight of 1000 to 5000, particularly 2000 to 3000. When polytetramethylene glycol with an average molecular weight of less than 1000 is used, the Young's modulus of the urethane acrylate of polytetramethylene glycol increases with temperature, as shown in the figure, and the Young's modulus of the resulting cured product decreases at high temperatures. When polytetramethylene glycol having an average molecular weight of more than 5000 is used, the urethane compound may have a high viscosity and the coating property of the resulting composition may be deteriorated.

Further, the diol is represented by the following general formula (II) HO-R-OH (II) (wherein R is a divalent hydrocarbon group), but in the present invention, the above ( I
As the diol of the formula (I), it is preferable to use one having a molecular weight of 300 or less. When a urethane compound is produced using a diol having a molecular weight of more than 300, the cured product may have poor mechanical properties. Specific examples of such diols include ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, 2,5-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,4 -Cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-benzenedimethanol and the like are exemplified.

In the present invention, the above-mentioned polytetramethylene glycol and diol are each reacted with an organic diisocyanate and a compound having a hydroxy group and an ethylenically unsaturated group to urethanize the polytetramethylene glycol and the diol, respectively. .

In this case, examples of the organic diisocyanate include isophorone diisocyanate, hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylene diisocyanate, 1,4-
Xylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethylphenylene diisocyanate, 4,4'-biphenylene One or more of diisocyanate, dicyclohexylmethane diisocyanate and methylenebis (4-cyclohexylisocyanate) are preferably used.

As the compound having a hydroxy group and an ethylenically unsaturated group, for example, compounds represented by the following general formulas (III) to (VII) can be used.

However, in the above formula, R ₁ is a hydrogen atom or a monovalent hydrocarbon group, and R ₂ is a divalent hydrocarbon group such as an ethylene group, a propylene group, a tetramethylene group, a pentamethylene group or a hexamethylene group. Specific examples of such a compound having a hydroxy group and an ethylenically unsaturated group include allyl alcohol, 2-hydroxyethyl acrylate or methacrylate, 2-hydroxypropyl acrylate or methacrylate, 2-hydroxyoctyl acrylate or methacrylate, pentaerythritol trichloride. Acrylate or methacrylate, glycerin diacrylate or methacrylate, dipentaerythritol monohydroxypentaacrylate or methacrylate, etc. are exemplified, and these can be used alone or in combination of two or more kinds.

In the present invention, the method for producing the urethane compound is not particularly limited, but polytetramethylene glycol or alkyl diol is reacted with an organic diisocyanate,
After obtaining a polytetramethylene compound or an alkyl compound having a terminal isocyanate group, a method of reacting this compound with a compound having a hydroxy group and an ethylenically unsaturated group, or having an organic diisocyanate and a hydroxy group and an ethylenically unsaturated group A method of reacting the reaction product with polytetramethylene glycol or an alkyl diol after reacting with a compound is suitably adopted.

Here, in the case of producing by the above method, the organic diisocyanate is used in an amount of 0.5 to 1 mol, particularly 0.8 to 1 mol, based on 1 mol of the hydroxyl group of polytetramethylene glycol or diol, and 30 to 100 ° C. In particular, the reaction is carried out at 50 to 80 ° C, and then the compound having a hydroxy group and an ethylenically unsaturated group is used in an equivalent amount to a slight excess amount, particularly in an equal amount, with respect to the isocyanate group of the obtained urethane compound. Then, the reaction is preferably carried out at 50 to 80 ° C. In the case of producing by the above-mentioned method, a compound having a hydroxy group and an ethylenically unsaturated group is used in an amount of 0.5 to 1 mol, particularly 0.8 to 1 mol per 1 mol of organic diisocyanate, and 30 to 80 mol is used. After reacting at 0 ° C., polytetramethylene glycol or diol is used at a ratio such that the hydroxyl groups of polytetramethylene glycol or diol are equimolar to the isocyanate groups of the reaction product,
By reacting at a temperature of -80 ° C, the target compound can be efficiently obtained.

When producing a urethane compound from polytetramethylene glycol, a tertiary amine, dibutyltin dilaurate, dioctyltin laurate or the like is added as a catalyst to accelerate the reaction between the isocyanate group and the hydroxyl group,
Hydroquinone, hydroquinone monomethyl ether, methylhydroquinone, t-butylmethylhydroquinone, p-benzoquinone, phenothiazine, etc. are added as polymerization inhibitors to prevent gelation due to radical polymerization of ethylenically unsaturated groups during the reaction. preferable.

On the other hand, when producing a urethane compound from a diol,
Depending on the type of diol or organic diisocyanate used, the reaction product may solidify or become highly viscous, so it is preferable to use a suitable solvent. As the solvent, a solvent which is inactive to an isocyanate group and dissolves a reaction product is used, and specifically, ethers such as tetrahydrofuran, isopropyl ether, butyl ether, and halides such as chloroform, dichloroethane, trichloroethane, etc. , And aromatic hydrocarbons such as toluene and xylene. In addition, this solvent is
After completion of the reaction, it is removed by a usual method.

In the present invention, the mixing amount of the urethane compound of polytetramethylene glycol and the urethane compound of diol is not limited at all, but the urethane compound of polytetramethylene glycol is preferably 10 to 95 relative to the entire composition.
% By weight, more preferably 20 to 80% by weight,
The urethane compound of the diol is preferably 5 to 80% by weight,
More preferably, it can be added in an amount of 20 to 50% by weight. Further, the mixing ratio of the urethane compound of polytetramethylene glycol and the urethane compound of diol is 20:80 to 90:10,
The range of 30:70 to 80:20 is particularly preferable.

In the composition of the present invention, as the first essential component, instead of the mixture of the urethane compound of polytetramethylene glycol and the urethane compound of diol, the mixture of polytetramethylene glycol and diol of the above-mentioned (b), A mixed reaction product obtained by reacting an organic diisocyanate with a compound having a hydroxy group and an ethylenically unsaturated group can be blended.

That is, in this case, the reaction for obtaining the urethane compound of the polytetramethylene glycol and the reaction for obtaining the urethane compound of the diol are simultaneously proceeded, and the mixed reaction product of the urethane compounds thus produced is blended as the first component.
Therefore, the mixed reaction product is obtained by mixing polytetramethylene glycol and a diol, reacting the mixture with an organic diisocyanate to form a urethane, and then reacting a compound having a hydroxy group and an ethylenically unsaturated group, or It can be obtained by reacting an organic diisocyanate with a compound having a hydroxy group and an ethylenically unsaturated group, and then reacting the reaction product with a mixture of polytetramethylene glycol and a diol. In this case, the reaction conditions can be in accordance with the method described above, but in particular, the urethane compound of polytetramethylene glycol and the urethane compound of diol produced are well compatible with each other,
It is preferable to mix the polytetramethylene glycol and the diol so that the resulting mixed reaction product of the urethane compound has an appropriate viscosity in the production. Depending on the kind of the diol used, a mixed reaction of the urethane compound usually formed. Urethane compound of diol is 70 with respect to the total amount of the product.
The mixing ratio of polytetramethylene glycol and diol is adjusted so as to be not more than%. Further, the mixing ratio of the urethane compound of polytetramethylene glycol and the urethane compound of diol is preferably 30:70 to 80:20. In addition,
In this reaction, it is not necessary to use a solvent, and therefore, the operation of removing the solvent after the reaction is completed is unnecessary, and the manufacturing process can be simplified.

The blending amount of the above-mentioned first essential component is preferably 15 to 95% by weight.

Then, as the monomer having an ethylenically unsaturated group which is the second essential component of the present invention, various acrylate compounds and methacrylate compounds can be preferably used, and specifically, 2-hydroxyethyl acrylate and 2-hydroxy Propyl acrylate, tetrahydrofurfuryl acrylate, butoxyethyl acrylate, ethyldiethylene glycol acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenoxyethyl acrylate, dicyclopentadiene acrylate, isobornyl acrylate, dicyclopentenyl acrylate, bornyl acrylate, isobornyl Oxyethyl acrylate, dicyclopentenyl oxyacrylate, polypropylene glycol acrylate, methyltriethylene glycol Acrylate, diethylaminoethyl acrylate, 7-amino-3,7-dimethyloctyl acrylate, trimethylolpropane triacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,4-butanediol diacrylate,
1,6-hexanediacrylate, neopentyl glycol diacrylate and their methacrylate compounds, polyethylene glycol acrylate or methacrylate, vinylpyrrolidone, vinylphenol, acrylamide, vinyl acetate, vinyl ether, styrene, polyester diacrylate or methacrylate, diallyl adipate, diallyl Phthalates, triallyl isocyanurates, vinylphenol A glycidyl ether adducts with acrylic acid or methacrylate at both ends, the following formula (VII
I) KAYARAD R-604, (IX) Formula KAYARAD-MANDA, (X)
Expression KAYARAD R-551 (Nippon Kayaku Co., Ltd.), (XI) Expression ACMO
(Made by Kojinsha) and the like are exemplified.

In addition, these compounds are classified into a monofunctional compound having one acrylate group or a methacrylate group in the molecule and a polyfunctional compound having a large number thereof, and when the monofunctional compound is used, the extensibility of the obtained composition is enhanced. Has a lower Young's modulus and the use of a polyfunctional compound increases the Young's modulus of the composition, but tends to lower the extensibility and flexibility. The type of compound, the combination method, the amount to be blended, etc. can be appropriately selected, but in the composition of the present invention, a low-viscosity acrylate compound having an acrylate group as a functional group is particularly preferable from the viewpoint of its curing rate and viscosity. Used for.

The amount of the second component to be added is not particularly limited, but is preferably 5% by weight or more, particularly 30 to 60% by weight, based on the entire composition. If the compounding amount is less than 5% by weight, the workability (increased viscosity), the curing speed, and the characteristics after curing of the composition of the present invention may be deteriorated.

Furthermore, the photopolymerization initiator which is the third essential component used in the present invention is not particularly limited as long as it initiates and accelerates the polymerization reaction of the urethane compound and the monomer having an ethylenically unsaturated group. Instead, various conventionally known compounds can be used. Specifically, as the photopolymerization initiator, 2,2-dimethoxy-2-phenylacetophenone,
Acetophenone, Benzophenone, Xanthone, Fluorenone, Benzaldehyde, Fluorene, Anthraquinone, Triphenylamine, 3-Methylacetophenone, 4-
Chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, N, N, N ', N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), benzoinpropyl ether, acetophenone diethyl ketal , Benzoin ethyl ether, benzyl methyl ketal, 1- (4-isopropylphenyl)
-2-Hydroxy-2-methylpropan-1-one, 2-
Hydroxy-2-methyl-1-phenylpropane-1-
ON, the following formula (XII) Ilgarcure-651 (manufactured by Ciba-Geigy) and other thioxanthone compounds are exemplified, and one or more of these compounds can be used.

The amount of the photopolymerization initiator used is preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight based on the total amount of the components of the composition of the present invention.
% By weight.

It should be noted that the composition of the present invention can be appropriately added and blended with various substances and compounds depending on the intended use of the cured product. The additives include hydroquinone and t-butylhydroquinone as thermal polymerization inhibitors, phthalocyanine blue, phthalocyanine phosphorus and titanium white as color pigments, silica as thickeners, calcium carbonate,
Examples thereof include kaolin clay and colloidal silica.

The ultraviolet-curable liquid composition of the present invention is preferably used as a coating material for glass fibers for optical communication, particularly as a secondary coating after primary coating of such fibers, that is, a top coating. From the viewpoint of sex, the composition has a viscosity of 500 to 20000 centipoise at 25 ° C, especially
It is preferably 1000 to 10000 centipoise. Further, the composition of the present invention preferably has a high elastic modulus so that the fiber can be protected from external stress when used for the top coating, and usually the modulus at 2.5% stretching can be maintained at 20 kg / mm ² or more. preferable.

The composition of the present invention is cured by irradiation with ultraviolet rays, and its ultraviolet ray source includes ultraviolet fluorescent lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, cannon lamps, carbon mark lamps, and sunlight. However, the dose can be appropriately selected.

EFFECTS OF THE INVENTION As described above, the ultraviolet curable liquid composition of the present invention has both properties of high Young's modulus and high extensibility when cured by irradiation with ultraviolet rays, and under high temperature. However, it retains a high Young's modulus and is suitable as a coating material for glass fiber for optical communication.

Next, synthetic examples of the urethane compound according to the present invention will be shown.

[Synthesis Example 1] Polytetramethylene glycol having an average molecular weight of 2000 (PTMG-2 manufactured by Sanyo Kasei Co., Ltd.) was placed in a reaction vessel equipped with a stirrer and a thermometer.
000) 465 g, 1,6-hexamethylene glycol 67.6 g (0.5
73 mol), 2,4-tolylene diisocyanate 280 g (1.61
Mol), and the mixture was reacted for 6 hours while maintaining the temperature at 60 to 70 ° C. After the reaction was completed, the reaction mixture was analyzed by gel permeation chromatography (GPC), and the result was 2,4
-95% or more of the toluene diisocyanate has reacted.

The isocyanated reaction mixture is then heated to about 40 ° C.
Cooled to 0.24 g of tert-butylhydroxytoluene,
After charging 0.14 g of dibutyltin dilaurate and 186.8 g (1.61 mol) of 2-hydroxyethyl acrylate, the reaction temperature was kept at 60 to 70 ° C., while the infrared absorption spectrum was measured, the absorption of the isocyanate group disappeared and the reaction The reaction was continued until completion. Obtained liquid reaction product (A)
Is a mixture of polytetramethylene glycol having urethane acrylates at both ends and 1,6-hexamethylene glycol.

[Synthesis Example 2] 478 g of polytetramethylene glycol having an average molecular weight of 2000 (PTMG-2000 manufactured by Sanyo Kasei Co., Ltd.), 60.9 g (0.586 mol) of neopentyl glycol, 290 g (1.67 mol) of 2,4-tolylene diisocyanate, Tributyl hydroxytoluene
A liquid reaction product (B) was obtained by the same procedure as in Synthesis Example 1 using 0.24 g, dibutyltin laurate 0.14 g and 2-hydroxyethyl acrylate 193 g (1.67 mol). The reaction product (B) is polytetramethylene glycol and neopentyl glycol both ends of which are urethane acrylated.

[Synthesis Example 3] 452 g of polytetramethylene glycol having an average molecular weight of 3000 (PTMG-3000 manufactured by Sanyo Kasei Co., Ltd.), 65.8 g (0.633 mol) of neopentyl glycol, 276 g (1.59 mol) of 2,4-tolylene diisocyanate, Tributyl hydroxytoluene
A liquid reaction product (C) was obtained in the same manner as in Synthesis Example 1 using 0.24 g, dibutyltin laurate 0.14 g and 2-hydroxyethyl acrylate 181.9 g (1.59 mol). This reaction product (C) is polytetramethylene glycol and neopentyl glycol both ends of which are urethane acrylated.

[Synthesis Example 4] 567 g of polytetramethylene glycol having an average molecular weight of 3000 (PTMG-3000 manufactured by Sanyo Kasei Co., Ltd.), 65.8 g (0.63 mol) of neopentyl glycol, 2,4-tolylene diisocyanate
290.3 g (1.67 mol), tert-butyl hydroxytoluene
A liquid reaction product (D) was obtained in the same manner as in Synthesis Example 1 using 0.24 g, dibutyltin laurate 0.14 g and 2-hydroxyacrylate 193.5 g (1.67 mol). This reaction product (D) is polytetramethylene glycol and neopentyl glycol both ends of which are urethane acrylated.

Synthesis Example 5 Polytetramethylene glycol having an average molecular weight of 3000 (PTMG-3000 manufactured by Sanyo Kasei Co., Ltd.) 452 g, 1,4-cyclohexanedimethanol 82 g (0.569 mol), 2,4-tolylene diisocyanate 254 g (1.46 mol) ), Tert-butylhydroxytoluene (0.24 g), dibutyltin laurate (0.14 g) and 2-hydroxyacrylate (169.5 g (1.46 mol)) were used to obtain a liquid reaction product (E) in the same manner as in Synthesis Example 1. The reaction product (E) is polytetramethylene glycol having both ends urethane-acrylated and 1,4-cyclohexanedimethanol.

[Synthesis Example 6] 1000 g of polytetramethylene glycol having an average molecular weight of 650 (PTMG-650 manufactured by Sanyo Kasei Co., Ltd.), 535.4 g (3.08 mol) of 2,4-tolylene diisocyanate, 0.48 g of tert-butylhydroxytoluene, and dibutyltin dilaurate. 0.28g, 2-
Liquid reaction product (F) was prepared in the same manner as in Synthesis Example 1 using 357.3 g (3.08 mol) of hydroxyethyl acrylate.
Got This reaction product (F) is polytetramethylene glycol having urethane acrylates at both ends.

[Synthesis Example 7] 1000 g of polytetramethylene glycol having an average molecular weight of 3000 (PTMG-3000 manufactured by Sanyo Kasei Co., Ltd.), 124.3 g of 1,4-toluene diisocyanate (0.714 mol), 0.48 g of tert-butylhydroxytoluene, and dibutyltin dilaurate. 0.28
A liquid reaction product (G) was obtained by the same procedure as in Synthesis Example 1 using g and 2-hydroxyethyl acrylate (82.8 g, 0.714 mol). This reaction product (G) is polytetramethylene glycol having urethane acrylate at both ends.

[Synthesis Example 8] In a reaction vessel equipped with a stirrer and a thermometer, 118 g (1 mol) of 1,6-hexamethylene glycol and 350 g of tetrahydrofuran.
348 g (2 mol) of g, 2,4-tolylene diisocyanate was charged, and the mixture was reacted for 8 hours while maintaining the temperature at 60 to 70 ° C. After the reaction was completed, the reaction mixture was analyzed by gel permeation chromatography (GPC). As a result, 95% or more of 2,4-toluene diisocyanate was reacted.

The isocyanated reaction mixture is then heated to about 40 ° C.
Cooled to 0.18 g of tert-butylhydroxytoluene,
After charging 0.09 g of dibutyltin dilaurate and 232 g of 2-hydroxyethyl acrylate, the reaction temperature was 60 to 70 ° C.
The reaction was continued until the absorption of the isocyanate group disappeared and the reaction was completed while measuring the infrared absorption spectrum. The obtained liquid reaction product (H) is 1,6-hexanemethylene glycol having urethane acrylates at both ends dissolved in tetrahydrofuran.

Synthesis Example 9 Neopentyl glycol 104 g (1 mol), tetrahydrofuran 350 g, 2,4-tolylene diisocyanate 348 g (2
Mol), tert-butylhydroxytoluene 0.18 g, dibutyltin laurate 0.09 g, and 2-hydroxyethyl acrylate 232 g (2 mol) were used to obtain a liquid reaction product (I) in the same manner as in Synthesis Example 8. . This reaction product (I) is neopentyl glycol having urethane acrylates at both ends dissolved in tetrahydrofuran.

[Synthesis Example 10] 1000 g of polytetramethylene glycol having an average molecular weight of 2000 (PTMG-2000 manufactured by Sanyo Kasei Co., Ltd.), 174 g (1 mol) of 1,4-toluene diisocyanate, 0.48 g of tert-butylhydroxytoluene, and 0.28 g of dibutyltin dilaurate. , 2-hydroxyethyl acrylate (116 g (1 mol)) was used to obtain a liquid reaction product (J) in the same manner as in Synthesis Example 1. This reaction product (J) is polytetramethylene glycol having urethane acrylates at both ends.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Examples 1 to 5] Reaction products A to E (mixed reaction products of urethane compounds of polytetramethylene glycol and diol) obtained in Synthesis Examples 1 to 5 and the above formulas (IX) and (XI) And a monomer having an ethylenically unsaturated group, and a photopolymerization initiator of the above formula (XII) were simply mixed in the compounding amounts shown in Table 1 to obtain an ultraviolet curable liquid composition (Examples 1 to 5). Prepared.

Then, using a die, an ultraviolet curable liquid composition having a modulus of 0.1 to 0.2 kg / mm ² (tensile modulus at 25 ° C.) is applied to the surface of a glass fiber for optical communication having a diameter of 125 μm in a thickness of 50 μm, This was passed under ultraviolet irradiation at a speed of 30 m / min, cured, and coated. At the same time, the above curable liquid compositions (compositions of Examples 1 to 5) were respectively applied to the surface of the coated fibers by using a die, and passed through at a speed of 30 m / min under irradiation of ultraviolet rays to obtain compositions. As a result, a glass fiber for optical communication having a uniform coating reinforcement was obtained.

In addition, the curable liquid compositions of Examples 1 to 5 were placed on a glass plate.
After applying it to a thickness of 200 μm, it is cured by irradiating it with ultraviolet rays from a distance of 10 cm for 1 second using a high pressure mercury lamp of 80 W / cm,
It was peeled off from the glass plate. Using the obtained cured film as a test piece, the mechanical properties of each composition were measured by the following methods.

Measuring method of mechanical properties Tensile strength: 25 ° C using a tensile tester, 25m between marked lines
m, tensile speed 50mm / min.

Elongation rate: Measured under the same conditions as tensile strength.

Modulus at 2.5% stretching: 25 ° C and 60 ° C using a tensile tester with constant temperature bath, 25mm between marked lines, 1m pulling speed
Measured under the condition of m / min.

[Comparative Examples 1 to 3] Reaction products F and G (urethane compound of polytetramethylene glycol) obtained in the above Synthesis Examples 6 and 7 and the above (IX),
Compositions (Comparative Examples 1 to 3) were prepared by simply mixing the compounds of the formulas (XI) and (XII) in the amounts shown in Table 1.

This composition was treated in the same manner as in Examples 1 to 5 to prepare a test piece, and its mechanical properties were measured by the same method as described above.

The above results are summarized in Table 1.

From the results in Table 1, the compositions containing only the urethane compound of polytetramethylene glycol as the urethane compound (Comparative Examples 1 to 3) have a low elongation rate or a low modulus at 2.5% stretching, The compositions of the present invention (Examples 1 to 5) have good elongation and modulus at 2.5% stretching at 25 ° C, and the modulus does not significantly decrease even at a high temperature of 60 ° C, and has a high Young's modulus and It was confirmed to have both high Young's modulus and high extensibility at high temperature.

Example 6 36 g of the reaction product H (urethane compound of diol) obtained in Synthesis Example 8, 36 g of the reaction product J (urethane compound of polytetramethylene glycol) obtained in Synthesis Example 10, the above compound (IX ) 35 g was charged into a flask, and under reduced pressure (2 mmH
g), the tetrahydrofuran was removed at 80 ° C. Then
To this mixture, 5 g of the compound (XI) and 3 g of the compound (XII) were added and simply mixed to prepare an ultraviolet curable liquid composition.

[Example 7] 38.8 g of reaction product I (urethane compound of diol) obtained in Synthesis Example 9 and reaction product G (urethane compound of polytetramethylene glycol) obtained in Synthesis Example 7 31.4
g, 38 g of the above compound (IX) was charged into a flask, and tetrahydrofuran was removed at 80 ° C. under reduced pressure (2 mmHg). Then, 5 g of the above compound (XI) and the compound (XI
I) 3 g was added and simply mixed to prepare an ultraviolet curable liquid composition.

The curable liquid compositions of Examples 6 and 7 were treated in the same manner as in Examples 1 to 5 and the mechanical properties were measured.

The above results are shown in Table 2.

From the results shown in Table 2, the compositions of the present invention (Examples 6 and 7) have a high Young's modulus, a high Young's modulus at high temperature and a high extensibility as in the compositions of Examples 1 to 5 above. I found out that

[Brief description of drawings]

The drawing shows polytetramethylene glycol having various average molecular weights and hydroxyl groups of this polytetramethylene glycol.
3 is a graph showing the relationship between Young's modulus and temperature of a cured product of a urethane compound obtained from 2 mol of 1,4-toluene diisocyanate and hydroxyethyl acrylate with respect to mol.

Claims (2)

[Claims] 1. A urethane compound obtained by reacting (1) polytetramethylene glycol with an organic diisocyanate and a compound having a hydroxy group and an ethylenically unsaturated group, and a compound of the formula HO-R-OH (where R is A mixture of a diol represented by a divalent hydrocarbon group), an organic diisocyanate, and a urethane compound obtained by reacting a compound having a hydroxy group and an ethylenically unsaturated group, or polytetramethylene glycol and the formula HO- RO
A mixed reaction product obtained by reacting a mixture of a diol represented by H (where R is a divalent hydrocarbon group), an organic diisocyanate, and a compound having a hydroxy group and an ethylenically unsaturated group, (2 ) A UV-curable liquid composition comprising a monomer having an ethylenically unsaturated group, and (3) a photopolymerization initiator. 2. The ultraviolet curable liquid composition according to claim 1, wherein the polytetramethylene glycol has an average molecular weight of 1000 to 5000, and the diol represented by the formula HO-R-OH has a molecular weight of 300 or less. object.