JP3341848B2 - Polymerizable unsaturated polyurethane and ultraviolet-curable resin composition using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polymerizable unsaturated polyurethane and an ultraviolet-curable resin composition using the same, and is particularly suitable for coating optical fibers.

[0002]

2. Description of the Related Art Optical fibers are very brittle and easily damaged.
It is well known that optical transmission loss increases due to contamination. For this reason, conventionally, immediately after spinning of an optical fiber, a glass surface is subjected to a primary coating with a material having a low elastic modulus, and then a secondary coating is performed with a material having a high elastic modulus.

[0003] In recent years, ultraviolet curable resins have been used from the viewpoint of productivity. Ultraviolet-curable resins are also used for bundling optical fibers with primary and secondary coatings into tapes.

[0004] Polyether urethane acrylate is widely used as the polymerizable unsaturated polyurethane used in the ultraviolet curable resin. Examples of the polyether polyol component constituting the known polyether urethane acrylate include polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, a copolymer of propylene oxide and ethylene oxide, and a copolymer of tetrahydrofuran and propylene oxide. And a copolymer of tetrahydrofuran and ethylene oxide, an adduct of bisphenol A with ethylene oxide and an adduct of bisphenol A with propylene oxide.

[0005] Among these, the ultraviolet curable resin for coating optical fibers includes polypropylene glycol (PP).
G), polyether urethane acrylate using polytetramethylene glycol (PTG) as a polyether polyol component is widely used.

[0006]

The properties required for the ultraviolet curable resin for optical fiber coating include (1) low viscosity, excellent workability at room temperature liquid, and (2) sufficient curing even at a low UV irradiation dose. (3) excellent long-term reliability, such as heat resistance, jelly resistance, and hydrolysis resistance of the cured coating film.

When polypropylene glycol is used as the polyether polyol component of the polyether urethane acrylate, it has low viscosity and excellent workability, but has a drawback of poor curability and heat resistance. On the other hand, when polytetramethylene glycol is used, it is excellent in curability and heat resistance, but has a drawback that workability is inferior because it has high crystallinity and becomes a solid at room temperature. Copolymers of tetrahydrofuran and propylene oxide have been studied to improve this drawback, but in reality the curability, heat resistance and the like are insufficient. Further, when polytetramethylene glycol is used, the Young's modulus of the cured coating film is high, so that when a low Young's modulus is required, its use is limited.

As described in Japanese Patent Application No. 2-184139, the present inventors use polybutylene glycol as a polyether polyol component to provide curability, heat resistance and hydrolysis resistance. UV curable resin for optical fiber coating was found to be excellent. Further, a coating film having a low Young's modulus can be obtained by the present material. However, this material has excellent hydrolysis resistance due to its strong hydrophobicity, but when the cable is filled with petroleum jelly as a waterproof material, the problem is that the jelly swells and the jelly resistance is low. Became.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a coating film having excellent curability, heat resistance, and hydrolysis resistance and a low Young's modulus. An optical fiber that exhibits the properties of polybutylene glycol, improves jelly resistance, has excellent long-term reliability such as curability, heat resistance, and jelly resistance, has low viscosity, and has excellent workability. An object of the present invention is to provide an ultraviolet-curable resin composition for coating.

The present invention has been made in order to solve the above problems.
(A) a polyether polyol obtained by ring-opening copolymerization of a mixture of 1,2-butylene oxide with propylene oxide or tetrahydrofuran as an essential component, (b) polyisocyanate and (c) active hydrogen which reacts with isocyanate groups And a polymerizable unsaturated polyurethane obtained by reacting a compound having a polymerizable unsaturated group (hereinafter, referred to as a polymerizable unsaturated polyurethane of the present invention). 2) To provide an ultraviolet curable resin composition containing a monomer having an ethylenically unsaturated bond and (3) a photopolymerization initiator.

The polymerizable unsaturated polyurethane used in the present invention contains 1,2-butylene oxide as an essential component, and is a polyether polyol, polyisocyanate and acryloyl obtained by ring-opening copolymerization of a mixture of propylene oxide or tetrahydrofuran with it. It can be obtained by reacting a hydroxy compound having a group.

[0012]

Of these, a polyether polyol obtained by a combination of 1,2-butylene oxide and propylene oxide and a combination of 1,2-butylene oxide and tetrahydrofuran constitute a polymerizable unsaturated polyurethane for coating an optical fiber. It is particularly suitable as a material. Commercially available polyether polyols comprising 1,2-butylene oxide and propylene oxide include, for example, "Z-3" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
004 ", commercially available polyether polyols comprising 1,2-butylene oxide and tetrahydrofuran include, for example," Unisafe DDC-30 "manufactured by NOF Corporation.
00 "and" THF / BO copolymer "manufactured by Hodogaya Chemical Co., Ltd.

1,2-butylene oxide and 1,2-butylene oxide
The use ratio of the alkylene oxide compound other than butylene oxide is preferably in the range of 20:80 to 90:10 by weight.

Examples of the polyisocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, tetramethyl xylylene diisocyanate, and trimethyl hexamethylene diisocyanate. 1,5-naphthalenediisocyanate, tolidine diisocyanate, p-phenylenediisocyanate,
Lysine diisocyanate and the like can be mentioned.

Examples of the hydroxy compound having an acryloyl group include hydroxyethyl acrylate, 2
-Hydroxypropyl acrylate, 2-hydroxybutyl acrylate, phenoxyhydroxypropyl acrylate, butoxyhydroxypropyl acrylate,
Pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, trimethylolpropane diacrylate, dipropylene glycol monoacrylate, 1,6-hexanediol monoacrylate, glycerin diacrylate, caprolactone-modified 2-hydroxyethyl acrylate, stearic acid-modified pentaerythritol Diacrylate and the like.

As the monomer having an ethylenically unsaturated bond used in the present invention, an acrylate compound is mainly used. When a cured film requires softness, a monofunctional (meth) acrylate compound is used. When a cured film requires hardness, a bifunctional or higher polyfunctional acrylate compound is used. Is generally used.

Specific examples of the monomer having an ethylenically unsaturated bond used in the present invention include aromatic vinyl monomers such as styrene, chlorostyrene and divinylbenzene; and methyl, ethyl, propyl, butyl and amyl as substituents. , 2-ethylhexyl, octyl, nonyl,
Dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl, phenoxyethyl, nonylphenoxyethyl, tetrahydrofurfuryl, allyl, methallyl, glycidyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-chloro-2-hydroxy Acrylate, methacrylate or fumarate having a group such as propyl, dimethylaminoethyl, diethylaminoethyl, etc .; ethylene glycol, polyethylene glycol, propylene glycol,
Mono (meth) acrylates or poly (meth) acrylates such as polypropylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, trimethylolpropane, glycerin and pentaerythritol; vinyl acetate, vinyl butyrate or vinyl benzoate; Acrylonitrile, cetyl vinyl ether, limonene, cyclohexene, diallyl phthalate,
2-, 3- or 4-vinylpyridine, acrylic acid, methacrylic acid, acrylamide, methacrylamide, N-hydroxymethylacrylamide or N-hydroxyethylacrylamide and their alkyl ether compounds, 2 mol or more per mol of neopentyl glycol Di (meth) acrylate of diol obtained by adding ethylene oxide or propylene oxide, di or tri (meth) acrylate of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane, 1 mol of bisphenol A and 2 mol or more of ethylene oxide or propylene oxide added to 1 mol of di (meth) acrylate or 2-hydroxyethyl (meth) acrylate of diol Le isocyanate or n-
Examples thereof include a reaction product with 1 mol of butyl isocyanate, and poly (meth) acrylate of dipentaerythritol.

Further, N-vinyl-2-pyrrolidone, N-
Acryloyl morpholine, N-vinyl imidazole,
At least one monomer selected from the group consisting of N-vinylcaprolactam, vinyl-p-tert-butylbenzoate, cyclohexyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, and dicyclopentenyl acrylate can also be used. When used in combination with the above (meth) acrylate, the curability is improved, a high gel fraction is obtained after curing, and a highly reliable material can be provided.

The photopolymerization initiator used in the present invention includes:
Any material may be used as long as it generates a radical by light and the radical efficiently reacts with the polymerizable unsaturated compound. There are a type in which a molecule is cleaved to generate a radical and a type in which a compound such as a combination of an aromatic ketone and a hydrogen donor is used in combination.

Examples of the former include, for example, benzoin ethyl ether, benzoin isobutyl ether,
Benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1
-Phenyl-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Methylpropan-1-one and 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropanone-1 and the like.

Examples of the latter aromatic ketones include, for example, benzophenone, 4-phenylbenzophenone, isophthalophenone, 4-benzoyl-4'-methyl-diphenylsulfide, 2,4-diethylthioxanthone, 2-isopropyl Thioxanthone, 2-chlorothioxanthone and the like can be mentioned, and as a hydrogen donor to be combined therewith, for example, a mercapto compound and an amine compound can be mentioned, but an amine compound is generally preferable.

Examples of the amine compound include triethylamine, methyldiethanolamine, triethanolamine, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, p-dimethylaminoacetophenone, p-dimethylaminoethyl benzoate,
-Dimethylaminoisoamyl benzoate, N, N-dimethylbenzylamine and 4,4'-bis (diethylamino) benzophenone.

These photopolymerization initiators may be used alone or in combination of two or more.

Further, as other components, a thermal polymerization inhibitor, an antioxidant, a plasticizer, a silane coupling agent, a surfactant, a polymerizable unsaturated polyurethane other than the present invention, etc. are compounded for the purpose of improving various properties. You can also.

The ultraviolet resin composition for coating an optical fiber of the present invention comprises (1) 10 to 80% by weight of a polymerizable unsaturated polyurethane, (2) 10 to 80% by weight of a monomer having an ethylenically unsaturated bond, and 0.1 to 10% by weight of polymerization initiator
It is preferable to mix | blend from the range of.

[0027]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

First, a synthesis example of the polymerizable unsaturated polyurethane of the present invention will be described.

(Synthesis Example 1) A copolymer of 1,2-butylene oxide (hereinafter abbreviated as BO) and propylene oxide (hereinafter abbreviated as PO) (BO: PO =
8: 2 (weight ratio, number average molecular weight: 5,000) 2 mol and 2,4-tolylene diisocyanate 3 mol were charged into a reaction vessel equipped with a nitrogen gas inlet tube, a stirrer and a cooling tube.
The reaction was performed at 0 ° C. for 2 hours.

Next, 2 mol of 2-hydroxypropyl acrylate, a trace amount of t-butylhydroquinone as a polymerization inhibitor and a trace amount of dibutyltin dilaurate as a catalyst are gradually added, and the mixture is further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-
1) was obtained.

(Synthesis Example 2) 1 mol of a copolymer of 1,2-butylene oxide and tetrahydrofuran (hereinafter referred to as THF) (BO: THF = 3: 7 (weight ratio), number average molecular weight 3,000), 2 mol of 2,4-tolylene diisocyanate was charged into a reaction vessel equipped with a nitrogen gas introducing tube, a stirrer and a cooling tube, and reacted at 70 ° C. for 2 hours.

Next, 2 mol of 2-hydroxypropyl acrylate, a trace amount of t-butylhydroquinone as a polymerization inhibitor and a trace amount of dibutyltin dilaurate as a catalyst were gradually added, and the mixture was further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-
2) was obtained.

Next, a synthesis example of a polymerizable unsaturated polyurethane as a control is shown.

(Synthesis Example 3) 2 mol of polybutylene glycol (number average molecular weight 5,000) and 3 mol of 2,4-tolylene diisocyanate were charged into a reaction vessel equipped with a nitrogen gas inlet tube, a stirrer and a cooling tube. The reaction was carried out at 2 ° C. for 2 hours.

Next, 2 mol of 2-hydroxypropyl acrylate, a trace amount of t-butylhydroquinone as a polymerization inhibitor and a trace amount of dibutyltin dilaurate as a catalyst are gradually added, and the mixture is further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-
3) was obtained.

Synthesis Example 4 1 mol of a copolymer of propylene oxide and tetrahydrofuran (PO: THF = 3: 7 (weight ratio), number average molecular weight 3,000) and 2 mol of 2,4-tolylene diisocyanate were added to nitrogen. The reactor was equipped with a gas inlet tube, a stirrer and a cooling tube and reacted at 70 ° C. for 2 hours.

Next, 2 mol of 2-hydroxypropyl acrylate, a trace amount of t-butylhydroquinone as a polymerization inhibitor and a trace amount of dibutyltin dilaurate as a catalyst were gradually added, and the mixture was further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-
4) was obtained.

(Synthesis Example 5) 1 mol of polypropylene glycol (number average molecular weight 3,000) and 2 mol of 2,4-tolylene diisocyanate were charged into a reaction vessel equipped with a nitrogen gas introducing pipe, a stirrer and a cooling pipe. The reaction was carried out at 2 ° C. for 2 hours.

Next, 2 mol of 2-hydroxypropyl acrylate, a trace amount of t-butylhydroquinone as a polymerization inhibitor and a trace amount of dibutyltin dilaurate as a catalyst were gradually added, and the mixture was further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-
5) was obtained.

(Synthesis Example 6) 1 mol of polytetramethylene glycol (number average molecular weight 3,000) and 2 mol of 2,4-tolylene diisocyanate were charged into a reaction vessel equipped with a nitrogen gas inlet tube, a stirrer and a cooling tube. At 70 ° C. for 2 hours.

Next, 2 mol of 2-hydroxypropyl acrylate, a trace amount of t-butylhydroquinone as a polymerization inhibitor and a trace amount of dibutyltin dilaurate as a catalyst were gradually added, and the mixture was further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-
6) was obtained.

(Synthesis Example 7) 1 mol of polybutylene glycol (number average molecular weight: 3,000) and 2 mol of 2,4-tolylene diisocyanate were charged into a reaction vessel equipped with a nitrogen gas inlet tube, a stirrer and a cooling tube. The reaction was performed at 70 ° C. for 2 hours.

Next, 2 mol of 2-hydroxypropyl acrylate, a trace amount of t-butylhydroquinone as a polymerization inhibitor and a trace amount of dibutyltin dilaurate as a catalyst were gradually added, and the mixture was further reacted at 70 ° C. for 15 hours to form an acryloyl group. Having a polymerizable unsaturated polyurethane (A-
7) was obtained.

Examples and comparative examples of the ultraviolet curable resin composition for coating an optical fiber of the present invention are shown below.

Example 1 50 parts by weight of polymerizable unsaturated polyurethane (A-1), 50 parts by weight of nonylphenoxy polyethylene glycol monoacrylate and 2,4,6-trimethylbenzoyldiphenylphosphine oxide obtained in Synthesis Example 1 2 parts by weight were mixed and dissolved at 60 ° C. for 1 hour to obtain a liquid ultraviolet curable resin composition having a viscosity of 55.5 poise (25 ° C.).

Comparative Example 1 The procedure of Example 2 was repeated, except that the polymerizable unsaturated polyurethane (A-3) was used instead of the polymerizable unsaturated polyurethane (A-1). A liquid ultraviolet curable resin composition having a viscosity of 118.6 poise (25 ° C.) was obtained.

Example 2 50 parts by weight of the polymerizable unsaturated polyurethane (A-2) obtained in Synthesis Example 2, 50 parts by weight of nonylphenoxypolypropylene glycol monoacrylate, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide 2 The parts by weight were mixed and dissolved at 60 ° C. for 1 hour to obtain a liquid ultraviolet curable resin composition having a viscosity of 57.3 poise (25 ° C.).

Comparative Example 2 The procedure of Example 1 was repeated, except that the polymerizable unsaturated polyurethane (A-4) was used instead of the polymerizable unsaturated polyurethane (A-2). A liquid ultraviolet-curable resin composition having a viscosity of 57.6 poise (25 ° C.) was obtained.

Comparative Example 3 The procedure of Example 1 was repeated, except that the polymerizable unsaturated polyurethane (A-5) was used instead of the polymerizable unsaturated polyurethane (A-2). A liquid UV-curable resin composition having a viscosity of 26.0 poise (25 ° C.) was obtained.

Comparative Example 4 The procedure of Example 1 was repeated, except that the polymerizable unsaturated polyurethane (A-6) was used in place of the polymerizable unsaturated polyurethane (A-2). A liquid UV-curable resin composition having a viscosity of 154.4 poise (25 ° C.) was obtained.

Comparative Example 5 The procedure of Example 2 was repeated, except that the polymerizable unsaturated polyurethane (A-7) was used instead of the polymerizable unsaturated polyurethane (A-2). A liquid UV-curable resin composition having a viscosity of 29.0 poise (25 ° C.) was obtained.

The following evaluations were performed using each of the ultraviolet-curable resin compositions obtained in Examples 1 and 2 and Comparative Examples 1 to 5, and the results are shown in Table 1. Based on this data, Table 2 shows a relative comparison of properties depending on the type of polyether.

(Evaluation of Curability) The UV-curable resin composition was applied on a glass plate so that the thickness of the dried coating film became 200 ± 20 μm, and then, using a metal halide lamp of 80 W / cm, in a nitrogen atmosphere. The curing was carried out by changing the irradiation light amount underneath. The tensile modulus (Young's modulus) of the cured film was measured, and the curability was evaluated.

The tensile modulus was measured according to JIS K7
113. In addition, as an index of curability, the ratio of the tensile modulus at the time of irradiation of 20 mJ / cm ² and 1000 mJ / cm ² was taken. The larger the value, the better the curability.

(Evaluation of Heat Resistance) The UV-curable resin composition was applied on a glass plate so that the thickness of the dried coating film became 200 ± 20 μm, and then, using a metal halide lamp of 80 W / cm, in a nitrogen atmosphere. To cure at an irradiation light amount of 200 mJ / cm ² . The cured film was stored in air at 120 ° C. for one week, and then the tensile modulus was measured in the same manner as described above. The ratio of this measured value to the initial value was used as an index of heat resistance.
The closer the value is to 1, the better the heat resistance.

(Evaluation of jelly resistance) A UV-curable resin composition was coated on a glass plate with a dry coating thickness of 200 ± 20 μm.
Then, using a metal halide lamp of 80 W / cm, the irradiation light amount was 200 mJ /
Cured in cm ² . The state of the cured film is adjusted at 23 ° C. and 50% RH, and the weight M1 is measured. Next, Jerry SY
After immersing in NCOLT (SYNCO Chemical) at 85 ° C. for 7 days, it is taken out, the jelly on the surface is wiped off, and the weight M2 is measured. Weight change = M2 / M1 × 100
(%) Was used as an index of jelly resistance. A value closer to 100 indicates better jelly resistance.

[0057]

[Table 1]

(In Table 1, the amount of irradiation is mJ / cm ² ,
The values of the Young's modulus were expressed in units of Kg / mm ² , and the curing speed was expressed as a ratio of the Young's modulus at the time of irradiation of 20 mJ / cm ² and 1000 mJ / cm ² . )

[0059]

[Table 2]

Evaluation method: Relative comparison based on data in Table 1 ◎: Excellent (however, it means that there is no crystallinity item) ○: Normal Δ: Inferior (however, there is some crystallinity item) PPG: Polypropylene glycol PTG: Polytetramethylene glycol PPTG: Copolymer of propylene oxide and THF PBG: Polybutylene glycol

[0061]

The jelly resistance is improved by the copolymer of butylene oxide and propylene oxide as compared with Example 1 and Comparative Example 1 in Table 1, and as shown in Example 2, Comparative Examples 2 to 5 and Table 2, With a copolymer of tetrahydrofuran and tetrahydrofuran, a product having an excellent total balance that cannot be obtained with existing products can be obtained. Therefore, the UV-curable resin composition for coating an optical fiber using the polymerizable unsaturated polyurethane of the present invention is excellent in workability and productivity, and further using the UV-curable resin composition for coating an optical fiber of the present invention. The coated optical fiber can obtain high reliability even in long-term use.

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Claims (3)

(57) [Claims] 1. A polyether polyol obtained by ring-opening copolymerization of a mixture of (a) 1,2-butylene oxide as an essential component and propylene oxide or tetrahydrofuran, (b) a polyisocyanate and (c) an isocyanate group A polymerizable unsaturated polyurethane obtained by reacting active hydrogen that reacts with a compound having a polymerizable unsaturated group. 2. An ultraviolet curable resin comprising (1) the polymerizable unsaturated polyurethane according to claim 1, (2) a monomer having an ethylenically unsaturated bond, and (3) a photopolymerization initiator. Composition. 3. The ultraviolet-curable resin composition according to claim 2, which is used for coating an optical fiber.