JP3055196B2 - UV curable resin composition for coating heat resistant optical fiber and optical fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a UV-curable resin composition having high heat resistance used for a secondary coating material and a tape material coated on an optical fiber, and an optical fiber having the cured coating formed thereon.

[0002]

2. Description of the Related Art Glass fibers used in communication optical fiber cables are brittle and easily damaged, and are coated with an ultraviolet-curing resin for protection, reinforcement, and the like. That is, the surface of the optical fiber is protected by coating a soft UV-curable resin (primary coating) immediately after the hot melt spinning of the base material (preform), and then coating the hard UV-curable resin (secondary coating). By doing so, the optical fiber is protected from external pressure. Also, four or five optical fibers coated with the primary coating and the secondary coating are bundled and hardened with an ultraviolet curing resin (tape structure) to protect the optical fibers from external pressure and to facilitate handling.

[0003]

The ultraviolet curable resin conventionally coated on an optical fiber is mainly composed of a polymerizable unsaturated polyether obtained by reacting a polyether polyol, a vinyl monomer having a hydroxyl group and a polyisocyanate. Since it is a polyurethane, it has a problem that it has low heat resistance and lacks long-term reliability. Further, the polymerizable unsaturated polyester polyurethane and the polymerizable unsaturated polycarbonate polyurethane having high heat resistance have a problem that the curing speed is slow.

An object of the present invention is to provide an ultraviolet curable resin composition for coating an optical fiber, which has a high curing speed and can provide a cured film having excellent heat resistance.

[0005]

In order to solve the above-mentioned problems, the present invention provides (1) (a) a polyester polyol and / or a polycarbonate polyol, and (b) 2-hydroxypropyl (meth) as a vinyl monomer having a hydroxyl group. A) acrylate and (c) a polymerizable unsaturated polyurethane obtained by reacting a polyisocyanate; (2) 2,4,6-trimethylbenzoyldiphenylphosphine oxide and / or 2-benzyl-2-dimethyl as a photopolymerization initiator Optical fiber coating containing amino-1- (4-morpholinophenyl) -butanone-1 and (3) tricyclodecanedimethanol di (meth) acrylate as a compound having two or more polymerizable vinyl groups in one molecule Provided is an ultraviolet curable resin composition for use.

The polyester polyol used in the present invention includes, for example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexane Diols, diol compounds such as neopentyl glycol and ε-caprolactone or β
-Methyl-δ-valerolactone; reaction product of the above diol compound with a dibasic acid such as succinic acid, adipic acid, phthalic acid, hexahydrophthalic acid and tetrahydrophthalic acid; And the above-mentioned dibasic acid and ε-caprolactone or β-methyl-δ-valerolactone.

The polycarbonate polyol used in the present invention includes, for example, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol,
Ethylene oxide 2 of diol compounds such as 1,4-butanediol, 1,8-octanediol, 1,4-bis- (hydroxymethyl) cyclohexane, 2-methylpropanediol, dipropylene glycol, dibutylene glycol and bisphenol A -6 mol addition reaction product; the above diol compound and oxalic acid, malonic acid, succinic acid, adipic acid,
Reaction products of dicarboxylic acids such as azelaic acid and hexahydrophthalic acid; polycarbonate polyols having a diol component of the above-mentioned diol compound and polyester diol as a reaction product of ε-caprolactone or β-methyl-δ-valerolactone; Polyester diols which are ethylene oxide, propylene oxide, ε-caprolactone or β-methyl-δ-valerolactone addition reaction products of polycarbonate polyols are exemplified.

Commercially available polycarbonate polyols include "Desmophen 2020E" (manufactured by Sumitomo Bayern), "DN-980" (manufactured by Nippon Polyurethane), and "D
N-981 "(manufactured by Nippon Polyurethane)," DN-98
2 "(manufactured by Nippon Polyurethane) and" DN-983 "(manufactured by Nippon Polyurethane).

These polyester polyols and polycarbonate polyols may be used alone or in combination of two or more.

As the vinyl monomer having a hydroxyl group,
In the present invention, 2-hydroxypropyl (meth) acrylate is essential. By using this, the following effects can be obtained in combination with other essential components of the present invention. Further, in the present invention, other vinyl monomers having a hydroxyl group can be used in combination as long as the effect is not impaired. Such monomers include, for example, hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, phenoxyhydroxypropyl acrylate, butoxyhydroxypropyl acrylate, pentaerythritol acrylate, dipentaerythritol monohydroxypentaacrylate, trimethylolpropane Diacrylate, dipropylene glycol monoacrylate, 1,6-hexanediol monoacrylate, glycerin diacrylate, caprolactone-modified 2-hydroxyethyl acrylate, stearic acid-modified pentaerythritol diacrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, poly Tetramethylene glycol monoacrylate Monoacrylate of copolymer of propylene oxide and ethylene oxide, monoacrylate of copolymer of tetrahydrofuran and propylene oxide, monoacrylate of copolymer of tetrahydrofuran and ethylene oxide, monoacrylate of ethylene oxide adduct of bisphenol A And monoacrylates of a propylene oxide adduct of bisphenol A.

These vinyl monomers having a hydroxyl group may be used alone or in combination of two or more.

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-naphthalene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate and lysine diisocyanate.

These polyisocyanate compounds may be used alone or in combination of two or more.

Hereinafter, a method for producing a polymerizable unsaturated polyurethane obtained by reacting (a) a polyester polyol and / or a polycarbonate polyol, (b) a vinyl monomer having a hydroxyl group and (c) a polyisocyanate will be exemplified.

(Production method 1) Polyester polyol and / or
Alternatively, a method of reacting a vinyl monomer having a hydroxyl group with a functional group of a polymer obtained by reacting a polycarbonate polyol and a polyisocyanate.

(Production method 2) A method of reacting a polyester polyol and / or a polycarbonate polyol with a functional group of an adduct obtained by reacting a polyisocyanate with a vinyl monomer having a hydroxyl group.

(Production method 3) Polyester polyol and / or
Alternatively, a method of simultaneously reacting a polycarbonate polyol molecular weight, a polyisocyanate, and a vinyl monomer having a hydroxyl group.

The proportion of the polymerizable unsaturated polyurethane used is preferably in the range of 30 to 90% by weight of the ultraviolet-curable resin composition of the present invention.

The ultraviolet-curable resin composition of the present invention comprises
The polymerizable unsaturated polyurethane obtained by reacting (d) a polyether polyol, (b) a vinyl monomer having a hydroxyl group, and (c) a polyisocyanate can be contained as long as the heat resistance of the cured film is not lost. . Therefore, the proportion of the polymerizable unsaturated polyurethane obtained by reacting the above (d), (b) and (c) is preferably in the range of 30% by weight or less of the ultraviolet-curable resin composition of the present invention.

Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, a copolymer of propylene oxide and ethylene oxide; a copolymer of tetrahydrofuran and propylene oxide; a copolymer of tetrahydrofuran and ethylene oxide; Examples include an ethylene oxide adduct of bisphenol A; a propylene oxide adduct of bisphenol A.

These commercial products include (1) polyethylene glycol, "PEG 60" manufactured by Sanyo Chemical Industries, Ltd.
0 "," PEG 1000 "," PEG 2000 ",
(2) As polypropylene glycol, “PPG diol 1000”, “PPG diol 2000” and “PPG diol 3000” manufactured by Mitsui Toatsu Chemicals, “Exenol 1020” and “Exenol 202” manufactured by Asahi Glass Co., Ltd.
0, “Exenol 3020”, and (3) polytetramethylene glycol “PTG” manufactured by Hodogaya Chemical Co., Ltd.
650 "," PTG 850 "," PTG 100
0 "," PTG 2000 "," PTG 4000 ",
(4) As a copolymer of propylene oxide and ethylene oxide, "ED-28" manufactured by Mitsui Toatsu Chemicals, "Exenol 510" manufactured by Asahi Glass Co., and (5) As a copolymer of tetrahydrofuran and propylene oxide,
“PPTG 1000” and “PPTG” manufactured by Hodogaya Chemical Co., Ltd.
2000 "," PPTG 4000 "," Unisafe DCB-1100 "," Unisafe
DCB-1800 ", (6)" Unisafe DC-1100 "," Unisafe DC-1 "manufactured by NOF Corporation as a copolymer of tetrahydrofuran and ethylene oxide.
800 ", (7) As a ethylene oxide adduct of bisphenol A," UNIOL DA-
400, UNIOL DA-700, and (8) propylene oxide adduct of bisphenol A such as "UNIOL DB-400" manufactured by NOF Corporation.

A compound having two or more polymerizable vinyl groups in one molecule increases the tensile modulus of the cured product.
It is important to mix and use the ultraviolet-curable resin composition of the present invention, and in the present invention, it is essential to use tricyclodecane dimethanol di (meth) acrylate. By using this, the following effects can be obtained in combination with other essential components of the present invention.

As the compound having two or more polymerizable vinyl groups in one molecule, other appropriate components can be used in an appropriate amount in addition to the above essential components as long as the effects of the present invention are not impaired. Such compounds include, for example, trimethylolpropane triacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, Pentyl glycol diacrylate,
Trimethylolpropane trioxyethyl acrylate, tricyclodecane dimethanol diacrylate, dicyclopentadiene diacrylate, tricyclodecanyl diacrylate, trimethylolpropane trioxypropyl acrylate, tris-2-hydroxyethyl isocyanurate triacrylate and tris- Examples thereof include 2-hydroxyethyl isocyanurate diacrylate.

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

When a compound having two or more polymerizable vinyl groups in one molecule is used, the proportion of the compound used is preferably not more than 60% by weight of the ultraviolet-curable resin composition of the present invention.

The compound having one polymerizable vinyl group in one molecule imparts sufficient tensile breaking elongation and tensile breaking strength to the cured product, so that the compound is used in the ultraviolet-curable resin composition of the present invention. Is preferred.

Examples of the compound having one polymerizable vinyl group in one molecule include N-vinylcaprolactam and N-vinylcaprolactam.
Vinyl-2-pyrrolidone, acryloylmorpholine, N-vinylimidazole, vinyl-pt-butylbenzoate,
Examples include cyclohexyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, and dicyclopentenyl acrylate. In particular, N-vinylcaprolactam, N-vinyl-2-pyrrolidone, acryloylmorpholine and N-vinylimidazole can be used to give a cured product with sufficient tensile elongation at break and tensile strength and further increase the curing speed. Particularly preferred.

These compounds having one polymerizable vinyl group in one molecule may be used alone or in combination of two or more.

When a compound having one polymerizable carbon-carbon double bond in one molecule is used, the proportion of the compound used is preferably 40% by weight or less of the ultraviolet-curable resin composition of the present invention.

Examples of the photopolymerization initiator include those that generate radicals by cleavage of molecules and those that are used in combination, such as a combination of an aromatic ketone and a hydrogen donor. Examples belonging to the former include, for example, benzoyl 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, 2-methyl-1- [4- (methylthio)
Phenyl] -2-morpholinopropanone-1,2-benzyl-2-
Dimethylamino-1- (4-morpholinophenyl) -butanone
-1 and the like. As the aromatic ketone of the latter example, for example, benzophenone, 4-phenylbenzophenone, isophthalophenone, 4-benzoyl-4'-methyl
-Diphenyl sulfide, 2,4-diethylthioxanthone, 2-isopropylthioxanthone and 2-chlorothioxanthone, and the like, and hydrogen donors combined with this include, for example, mercapto compounds and amine compounds. Generally, amine compounds are preferred.

Examples of the amine compound include triethylamine, methyldiethanolamine, triethanolamine, diethylaminoethyl (meth) acrylate, p-dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, , N-dimethylbenzylamine and 4,4'-bis (diethylamino) benzophenone.

Among the above-mentioned photopolymerization initiators, those which are important as essential components in the ultraviolet-curable resin composition of the present invention have a large molecular extinction coefficient, a high quantum yield, and a polymerizable unsaturated group. Is a highly reactive compound. In the present invention, as such a photopolymerization initiator, 2,4,6-
Trimethylbenzoyldiphenylphosphine oxide (product name "Lucillin TPO" manufactured by BASF) and 2-
Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (product name "Irgacure 369" manufactured by Ciba-Geigy) was selected as a particularly effective one in relation to other essential components. ing.

These two types of photopolymerization initiators may be used alone or in combination of two types. In addition, besides these two types of photopolymerization initiators, the above-mentioned photopolymerization initiators can also be used in combination.

The proportion of the photopolymerization initiator used is preferably in the range of 0.1 to 10% by weight of the ultraviolet-curable resin composition of the present invention.

Further, as other additives, a thermal polymerization inhibitor, an antioxidant, a plasticizer, a silane coupling agent and the like may be added to the ultraviolet-curable resin composition of the present invention for the purpose of improving various properties. it can.

[0036]

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) "Kurapol PKA-A"
(Polyester polyol obtained by the reaction of adipic acid, isophthalic acid and methylpentanediol, manufactured by Kuraray Co., Ltd.) 1 mole of 2,4-tolylene diisocyanate and 2 mole of 2,4-tolylene diisocyanate It was charged in a container and reacted at 70 ° C. for 2 hours. Next, 2 mol of 2-hydroxypropyl acrylate, a trace amount of a polymerization inhibitor
t-Butylhydroquinone and a trace amount of dibutyltin dilaurate were gradually added as a catalyst, and further reacted at 60 ° C. for 5 hours to obtain a polymerizable unsaturated polyurethane (A).

(Synthesis Example 2) 1 mol of "DN-981" (polycarbonate polyol manufactured by Nippon Polyurethane)
2 mol of 2,4-tolylene diisocyanate was charged into a reaction vessel equipped with a nitrogen gas inlet tube, a stirrer and a cooling tube, and was heated to 70 ° C.
For 2 hours. Next, 2 mol of 2-hydroxypropyl acrylate, a small amount of t-butylhydroquinone as a polymerization inhibitor and a small amount of dibutyltin dilaurate as a catalyst were gradually added, and the mixture was further reacted at 60 ° C. for 5 hours to obtain a polymerizable unsaturated polyurethane ( B) was obtained.

(Synthesis Example 3) 1 mol of polytetramethylene glycol (number average molecular weight: 850) 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 performed at 70 ° C. for 2 hours. Next, 2 mol of 2-hydroxypropyl acrylate, a small amount of t-butylhydroquinone as a polymerization inhibitor and a small amount of dibutyltin dilaurate as a catalyst were gradually added, and the mixture was further reacted at 60 ° C. for 5 hours to obtain a polymerizable unsaturated polyurethane ( C) was obtained.

Examples and comparative examples of the UV-curable resin composition for coating a heat-resistant optical fiber of the present invention are shown below.

Example 1 60 parts by weight of the polymerizable unsaturated polyurethane (A) obtained in Synthesis Example 1
02 "(tricyclodecane dimethanol diacrylate manufactured by Mitsubishi Yuka Co., Ltd.), 15 parts by weight of N-vinyl-2-pyrrolidone and" IRGACURE 369 "(2-benzyl-2-dimethylamino- manufactured by Ciba-Geigy) One part by weight of 1- (4-morpholinophenyl) -butanone-1) was mixed and dissolved at 60 ° C. for 1 hour to obtain a liquid ultraviolet curable resin composition having a viscosity of 162 poise (25 ° C.).

(Example 2) 60 parts by weight of the polymerizable unsaturated polyurethane (A) obtained in Synthesis Example 1, 20 parts by weight of tricyclodecane dimethanol diacrylate, 15 parts by weight of N-vinyl-2-pyrrolidone and "lucirin" TPO ”(2, made by BASF)
2 parts by weight of 4,6-trimethylbenzoyldiphenylphosphine oxide) were mixed and dissolved at 60 ° C. for 1 hour to obtain a liquid ultraviolet curable resin composition having a viscosity of 158 poise (25 ° C.).

Example 3 60 parts by weight of the polymerizable unsaturated polyurethane (B) obtained in Synthesis Example 2, 20 parts by weight of tricyclodecane dimethanol diacrylate, 15 parts by weight of N-vinyl-2-pyrrolidone and Irgacure 369 ”1 part by weight to 60
The mixture was mixed and dissolved at 1 ° C. for 1 hour to obtain a liquid ultraviolet curable resin composition having a viscosity of 500 poise (25 ° C.).

(Comparative Example 1) 60 parts by weight of the polymerizable unsaturated polyurethane (C) obtained in Synthesis Example 3, 20 parts by weight of tricyclodecane dimethanol diacrylate, 15 parts by weight of N-vinyl-2-pyrrolidone, and Irgacure 369 ”1 part by weight to 60
The mixture was mixed and dissolved at 1 ° C. for 1 hour to obtain a liquid UV-curable resin composition having a viscosity of 32 poise (25 ° C.).

Comparative Example 2 60 parts by weight of the polymerizable unsaturated polyurethane (A) obtained in Synthetic Example 1, 20 parts by weight of tricyclodecane dimethanol diacrylate, 15 parts by weight of N-vinyl-2-pyrrolidone, and Irgacure 651 "(benzyl dimethyl ketal manufactured by Ciba-Geigy) was mixed and dissolved at 60 ° C for 1 hour to obtain a liquid ultraviolet-curable resin composition having a viscosity of 159 poise (25 ° C).

Table 1 shows the physical properties of the ultraviolet curable resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 and 2. The number shown in the composition column is a blending amount, and the blending amount is shown in parts by weight.

Next, the following measurements and tests were carried out on each of the ultraviolet-curable resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 and 2, and the results are shown in the physical properties column of Table 1.

(Method of Measuring Tensile Secant Modulus) Each composition was applied on a glass plate at a film thickness of 50 ± 10 μm, and ultraviolet rays were irradiated at 20 mJ / cm ² under a nitrogen atmosphere using a metal halide lamp (lamp output: 2 kW). Alternatively, irradiation was performed at 1 J / cm ² to prepare a film-shaped sample. A No. 2 test piece was punched out of this film-shaped sample, and the tensile secant modulus was measured in accordance with JIS K7113. However, the tensile speed was 4% strain / min, and the tensile secant modulus was calculated from the tensile stress at 2.5% strain.

(Test Method for Heat Resistance) Each composition was applied on a glass plate at a film thickness of 200 ± 20 μm, and ultraviolet rays were irradiated under a nitrogen atmosphere using a metal halide lamp (lamp output: 2 kW).
Irradiation was performed at 200 mJ / cm ² to prepare a film-shaped sample. The film was exposed to circulating air at 160 ° C., taken out at appropriate times, and evaluated using the number of days when the tensile secant modulus of the film was doubled before exposure.

[0051]

[Table 1]

[0052]

According to Table 1, the UV-curable resin compositions obtained in Examples 1, 2, and 3 and Comparative Example 1 showed an ultraviolet irradiation dose of 20 mJ / cm.
^It can be seen that there is almost no difference in the tensile secant modulus at ² and 1 J / cm ² , and the curing is extremely fast. This is because it contains a photopolymerization initiator having a large molecular extinction coefficient, a high quantum yield, and a high reactivity with a polymerizable unsaturated group, and is excellent as an ultraviolet curable resin for coating an optical fiber. On the other hand, the ultraviolet-curable resin composition obtained in Comparative Example 2 has a large molecular extinction coefficient, a high quantum yield, and does not contain a photopolymerization initiator having high reactivity with a polymerizable unsaturated group. Is slow and is not suitable as an ultraviolet curable resin for coating an optical fiber. Further, Examples 1 and 2, which contain the polymerizable unsaturated polyurethane of the present invention, have high heat resistance and are excellent as ultraviolet curing resins for coating optical fibers. It can be understood that Comparative Example 1 containing no polymerizable unsaturated polyurethane used in the present invention has low heat resistance and is not suitable as an ultraviolet curable resin for coating an optical fiber.

[0053]

As described above, the ultraviolet-curable resin composition of the present invention comprises 2
A polymerizable unsaturated polyurethane having an unsaturated group derived from -hydroxypropyl (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate as a compound having two polymerizable vinyl groups in one molecule, The action of the photopolymerization initiator, i.e., 2,4,6-trimethylbenzoyldiphenylphosphine oxide and / or 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, together with the whole, Even when the polyol-derived portion in the polymerizable unsaturated polyurethane has a polyester and / or polycarbonate skeleton, its curing rate is high, and a cured product derived from a resin having such a skeleton has high heat resistance. The resin composition that provides such a cured product is a UV-curable resin composition for coating optical fibers. It is excellent. An optical fiber having a cured coating derived from this resin composition has extremely excellent heat resistance.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C09D 175/16 C03C 25/02 B (56) References JP-A-63-275619 (JP, A) JP-A-2-9732 (JP, A JP-A-2-34620 (JP, A) JP-A-62-177012 (JP, A) JP-A-61-291612 (JP, A) JP-A-63-130611 (JP, A) 108477 (JP, A) JP-A-61-31330 (JP, A) JP-A-4-202412 (JP, A) International publication 90/13579 (WO, A1) International publication 90/10662 (WO, A1) International publication 90/10660 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 290/00-290/14 C08F 299/00-299/08 C03C 25/00-25/02 C08F 2 / 46-2/50 C08G 18/00-18/87 C09D 1/00-201/10 G02B 6/00-6/54

Claims (3)

(57) [Claims] 1. A polymerizable compound obtained by reacting (1) (a) a polyester polyol and / or a polycarbonate polyol, (b) a 2-hydroxypropyl (meth) acrylate as a hydroxyl group-containing vinyl monomer and (c) a polyisocyanate. Unsaturated polyurethane, (2) as a photopolymerization initiator, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and / or 2-
Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and (3) tricyclodecane dimethanol di (meth) acrylate as a compound having two or more polymerizable vinyl groups in one molecule. An ultraviolet-curable resin composition for coating a heat-resistant optical fiber. 2. The ultraviolet-curable resin composition for coating a heat-resistant optical fiber according to claim 1, which contains a compound having one polymerizable vinyl group in one molecule. 3. An optical fiber having a cured coating of the ultraviolet-curable resin composition according to claim 1.