JPH04310547A - Ultraviolet ray-curing type resin composition for optical fiber coating - Google Patents

Abstract

PURPOSE:To decrease the surface tackiness of a cured resin by adding a polyether-modified dimethylpolysiloxane to the title composition consisting of a specific polymerizable unsaturated polyurethane and a photopolymerization initiator. CONSTITUTION:A polyetherpolyol (a) (e.g. polytetramethylene glycol) is made to react with a vinyl monomer (b) (e.g. 2-hydroxypropyl acrylate) having hydroxyl group and a polyisocyanate (c) (e.g. 2,4-tolylene diisocyanate) to afford a polymerizable unstaturated polyurethane (1). The unsaturated polyurethane (1) is mixed with a polyether-modified dimethylpolysiloxane (2) and a photopolymerization initiator (3) (e.g. 2-methyl-1-4-(methythio)phenyl-2- morpholiopropanone-1) to provide the objective composition having small surface tackiness. Furthermore, the photopolymerization initiator has pref. >=500 in maximum molecular absorption coefficient in ultraviolet ray region.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet curable resin composition for coating optical fibers. Specifically, the present invention relates to an ultraviolet curing secondary coating material and a tape material that are coated on an optical fiber.

0002

2. Description of the Related Art Glass fibers used in optical fiber cables for communications are brittle and easily damaged, so they are coated with ultraviolet curing resin for protection, reinforcement, and the like. In other words, the optical fiber surface is protected by coating the base material (preform) with a soft ultraviolet curable resin (primary coating) immediately after hot melt spinning, and then coating it with a hard ultraviolet curable resin (secondary coating). This protects the optical fiber from external pressure. Additionally, four or five optical fibers with primary and secondary coatings are bundled together and hardened with ultraviolet curable resin (tape structure) to facilitate handling.

0003

[Problems to be Solved by the Invention] Conventional ultraviolet curing secondary coating materials that have been used to coat optical fibers have a large surface tack. There is a problem in that the optical fiber cannot be drawn out at a more constant speed. Similarly, the ultraviolet curable tape material conventionally used to coat optical fibers has a problem in that the optical fibers cannot be drawn out from the drum at a constant speed in the next step. Furthermore, there is a problem in that the tape-structured optical fibers come into close contact within the cable, increasing the loss of transmission signals.

The problem to be solved by the present invention is to provide an ultraviolet curable resin composition that can provide an optical fiber coating with low surface tackiness.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides (1) (a) polyether polyol,
(b) a polymerizable unsaturated polyurethane obtained by reacting a vinyl monomer having a hydroxyl group and (c) a polyisocyanate; (2) a polyether-modified dimethylpolysiloxane; and (3) a photopolymerization initiator. The present invention provides an ultraviolet curable resin composition for coating an optical fiber, further containing a photopolymerization initiator having a maximum molecular extinction coefficient of 500 or more in the ultraviolet region, and further comprising a photopolymerization initiator having a maximum molecular extinction coefficient of 500 or more in the ultraviolet ray region. Provided is an ultraviolet curable resin composition for coating optical fibers that further reduces tack.

[0006] In the following, the present invention will be explained in detail.

Examples of the polyether polyol used in the present invention include polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, a copolymer of propylene oxide and ethylene oxide, a copolymer of tetrahydrofuran and propylene oxide, Copolymer of tetrahydrofuran and ethylene oxide, copolymer of butylene oxide and ethylene oxide, copolymer of butylene oxide and propylene oxide, copolymer of tetrahydrofuran and butylene oxide, ethylene oxide adduct of bisphenol A, propylene of bisphenol A Examples include oxide adducts.

These commercially available products include (1) ``PEG 6'' manufactured by Sanyo Chemical Co., Ltd. as polyethylene glycol;
00”, “PEG 1000”, “PEG2000”
(2) As polypropylene glycol, "PPG Diol 1000", "PPG Diol 2000", "PPG Diol 3000" manufactured by Mitsui Toatsu Chemical Co., Ltd., "Excenol 1020", "Excenol 202" manufactured by Asahi Glass Co., Ltd.
0", "Excenol 3020", (3) as polytetramethylene glycol, "PTG" manufactured by Hodogaya Chemical Co., Ltd.
650”, “PTG 850”, “PTG 10”
00”, “PTG 2000”, “PTG 400”
0", (4) As a copolymer of propylene oxide and ethylene oxide, "ED-28" manufactured by Mitsui Toatsu Chemical Co., Ltd.
”, “Excenor 510” manufactured by Asahi Glass Co., Ltd. (5)
As a copolymer of tetrahydrofuran and propylene oxide, "PPTG 1000" manufactured by Hodogaya Chemical Co., Ltd.
"PPTG2000", "PPTG 4000", "Unisafe DCB-1100" manufactured by NOF Corporation, "
(6) As a copolymer of tetrahydrofuran and ethylene oxide, "Unisafe DC-1100" and "Unisafe DC-1800" manufactured by NOF Corporation, (7) Bisphenol A
As an ethylene oxide adduct of
Unior DA-400”, “Unior DA
-700'', (8) As a propylene oxide adduct of bisphenol A, ``Uniol'' manufactured by NOF Corporation
DB-400'', etc.

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

Examples of the vinyl monomer having a hydroxyl group used in the present invention include hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, phenoxyhydroxypropyl acrylate, butoxyhydroxypropyl acrylate, pentaerythritol acrylate, dipenta Erythritol 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 Acrylate, polypropylene glycol monoacrylate, polytetramethylene glycol monoacrylate, monoacrylate of a copolymer of propylene oxide and ethylene oxide, monoacrylate of a copolymer of tetrahydrofuran and propylene oxide, monoacrylate of a copolymer of tetrahydrofuran and ethylene oxide Examples include monoacrylate, monoacrylate of ethylene oxide adduct of bisphenol A, and monoacrylate of propylene oxide adduct of bisphenol A.

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

Examples of the polyisocyanate compound used in the present invention include tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate,
Examples include isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, tetramethylxylylene diisocyanate, trimethylhexamethylene diisocyanate, 1,5-naphthalene diisocyanate, toridine diisocyanate, p-phenylene diisocyanate, lysine diisocyanate, and the like.

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

[0014] The method for producing the polymerizable unsaturated polyurethane used in the present invention will be exemplified below.

(Production method 1) A method in which a vinyl monomer having a hydroxyl group is reacted with a functional group of a polymer obtained by reacting a polyether polyol and a polyisocyanate.

(Production method 2) A method in which a polyether polyol is reacted with a functional group of an adduct obtained by reacting a polyisocyanate with a vinyl monomer having a hydroxyl group.

(Production method 3) A method in which a polyether polyol, a polyisocyanate, and a vinyl monomer having a hydroxyl group are reacted simultaneously.

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 contains (
It is also possible to contain 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. However, since the polymerizable unsaturated polyurethane is extremely difficult to mix with the polyether-modified dimethylpolysiloxane, which is an essential component of the ultraviolet curable resin composition of the present invention, the amount used is limited to the amount used in the ultraviolet curable resin composition of the present invention. The content is limited to 30% by weight or less.

Examples of polyester polyols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and neopentyl glycol. Diol compounds such as ε-caprolactone or β-
Addition reaction product of methyl-δ-valerolactone; Reactive product of the above diol compound with a dibasic acid such as succinic acid, adipic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid; The above diol compound and a three-component reaction product of the above dibasic acid and ε-caprolactone or β-methyl-δ-valerolactone.

Examples of polycarbonate polyols include 1,6-hexanediol, 3-methyl-1,5
-Pentanediol, neopentyl glycol, 1,4
-butanediol, 1,8-octanediol, 1,4
- Addition reaction product of 2 to 6 moles of ethylene oxide with a diol compound such as bis-(hydroxymethyl)cyclohexane, 2-methylpropanediol, dipropylene glycol, dibutylene glycol, or bisphenol A; the above diol compound and oxalic acid, malonic acid , reaction products with dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, and hexahydrophthalic acid; the above diol compounds and ε
- Polycarbonate polyols whose diol component is polyester diol, etc. which is an addition reaction product of caprolactone or β-methyl-δ-valerolactone; ethylene oxide, propylene oxide, ε-caprolactone or β-methyl-
Examples include polyester diol which is a δ-valerolactone addition reaction product.

Examples of the polyether-modified dimethylpolysiloxane used in the present invention include (1) alternating copolymers or random multicomponent copolymers of dimethylsiloxane and ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, etc.; (2) A block copolymer of dimethylpolysiloxane and the polyether polyol, and (3) a pendant polyether-modified dimethylpolysiloxane in which a polyether polyol group is introduced as a side chain into dimethylpolysiloxane.

[0023] Examples of these commercially available products include "DC-57" and "DC-190" manufactured by Dow Corning, and "L-7001" and "L-7002" manufactured by Nippon Unicar.
, "L-7500", "L-720", "L-77",
"L-722", "L-7602", "SH-28PA", "ST-86PA", "S" manufactured by Toray Silicone
F-8416", "SF-8419", "KP-322", "KP-323" and "KP-34" manufactured by Shin-Etsu Chemical Co., Ltd.
1'' etc.

These polyether-modified dimethylpolysiloxanes may be used alone or in combination of two or more.

The proportion of the polyether-modified dimethylpolysiloxane used is 0.0% in the ultraviolet curable resin composition of the present invention.
A range of 0.01 to 3% by weight is preferred.

A compound having two or more polymerizable vinyl groups in one molecule can be used in combination with the ultraviolet curable resin composition of the present invention for the purpose of increasing the tensile modulus of the cured product.

Examples of these compounds having two or more polymerizable vinyl groups in one molecule include trimethylolpropane triacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate,
Polyethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane trioxyethyl acrylate, tricyclodecane dimethanol diacrylate,
Dicyclopentadiene diacrylate, tricyclodecanyl diacrylate, trimethylolpropane trioxypropyl acrylate, tris-2-hydroxyethyl isocyanurate triacrylate, tris-2-hydroxyethyl isocyanurate diacrylate, polymerizable unsaturated polyurethane, etc. can be mentioned.

When these compounds having two or more polymerizable vinyl groups in one molecule are used, they may be used alone or in combination of two or more.

The proportion of the compound having two or more polymerizable vinyl groups in one molecule is preferably 60% by weight or less of the ultraviolet curable resin composition of the present invention.

A compound having one polymerizable vinyl group in one molecule gives the cured product tensile elongation at break and tensile strength at break, and can be used in combination with the ultraviolet curable resin composition of the present invention. can.

Examples of compounds having one polymerizable vinyl group in one molecule include N-vinylcaprolactam,
N-vinyl-2-pyrrolidone, acryloylmorpholine, N-vinylimidazole, vinyl-pt-butylbenzoate, cyclohexyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, and the like. especially,
N-vinylcaprolactam, N-vinyl-2-pyrrolidone, acryloylmorpholine, and N-vinylimidazole are particularly suitable for use because they provide the cured product with sufficient tensile elongation at break and tensile strength at break, and also speed up curing. preferable.

When these compounds having one polymerizable vinyl group in one molecule are used, they may be used alone or in combination of two or more.

The proportion of the compound having one polymerizable vinyl group per molecule is preferably 30% by weight or less of the ultraviolet curable resin composition of the present invention.

As photopolymerization initiators, there are those whose molecules cleave to generate radicals, and those which are used in combination, such as a combination of an aromatic ketone and a hydrogen donor. Examples belonging to the former include benzoylethyl ether,
Benzoin isobutyl ether, benzyl dimethyl ketal, 1-hydroxycyclohexylphenyl ketone,
2-Hydroxy-2-methyl-1-phenyl-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1- on, 2-methyl-1-[4-(methylthio)phenyl]
-2-morpholinopropanone-1,2-benzyl-2-
Dimethylamino-1-(4-morpholinophenyl)-
Butanone-1 etc. can be mentioned. Examples of the latter aromatic ketones include, for example, benzophenone, 4-phenylbenzophenone, isophthalophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 2,4-
Diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, etc. are mentioned, and hydrogen donors to be combined with these include, for example, mercapto compounds and amine compounds, but amine compounds are generally preferred.

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

Among the above photopolymerization initiators, if the maximum molecular extinction coefficient in the ultraviolet region (the maximum value of the absorption coefficient of electromagnetic waves with a wavelength of 200 to 400 nm) is 500 or more, the usage ratio of the photopolymerization initiator is At least most of the irradiated ultraviolet light is absorbed near the resin surface, and a large amount of photopolymerization initiator molecules are cleaved near the resin surface to generate radicals. Therefore, curing inhibition caused by oxygen is reduced, and the tackiness of the resin surface is reduced. Maximum molecular extinction coefficient in the ultraviolet region is 500
Even if the ratio is below, the same effect can be obtained by increasing the proportion of the photopolymerization initiator used. However, if the proportion used is too large, the proportion of uncured portions of the cured product will increase, resulting in a decrease in reliability as a coating material. As a photopolymerization initiator having a maximum molecular extinction coefficient of 500 or more in the ultraviolet region, for example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (maximum molecular extinction coefficient 606, product name "Lucirin TPO" manufactured by BASF) , 2-methyl-1-[4-(methylthio)phenyl]
-2-morpholinopropanone-1 (maximum molecular extinction coefficient 1
8600, product name "Irgacure 907" manufactured by Ciba-Geigy) and 2-benzyl-2-dimethylamino-
1-(4-morpholinophenyl)-butanone-1 (maximum molecular extinction coefficient 8340, product name "Irgacure 36")
9'' (manufactured by Ciba-Geigy), etc.

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

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.

[0039] Other additives such as thermal polymerization inhibitors, antioxidants, plasticizers, and silane coupling agents can also be added for the purpose of improving various properties.

[0040]

EXAMPLES Next, the present invention will be explained 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 shown.

(Synthesis Example 1) 1 mole of polytetramethylene glycol (number average molecular weight: 850) and 2 moles of 2,4-tolylene diisocyanate were charged into a reaction vessel equipped with a nitrogen gas introduction tube, a stirrer, and a cooling tube. The reaction was carried out at 60°C for 2 hours. Next, 2 moles 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.
The mixture was further reacted at 70° C. for 5 hours to obtain a polymerizable unsaturated polyurethane (A).

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

(Example 1) 60 parts by weight of the polymerizable unsaturated polyurethane (A) obtained in Synthesis Example 1, tris-2-hydroxyethyl isocyanurate triacrylate (product name:
20 parts by weight of "Fancryl FA-731A" (manufactured by Hitachi Chemical), 15 parts by weight of N-vinyl-2-pyrrolidone, "Irgacure 907" (2-methyl-1-
[4-(methylthio)phenyl]-2-morpholinopropanone-1) 3 parts by weight and "DC-190" (polyether-modified dimethylpolysiloxane manufactured by Dow Corning)
0.1 part by weight was mixed and dissolved at 60°C for 1 hour, and the viscosity was 41.
A poise (25° C.) liquid ultraviolet curable resin composition was obtained.

(Example 2) 60 parts by weight of the polymerizable unsaturated polyurethane (A) obtained in Synthesis Example 1, 20 parts by weight of tris-2-hydroxyethyl isocyanurate triacrylate, and 15 parts by weight of N-vinyl-2-pyrrolidone. , "Irgacure 651" (benzyl dimethyl ketal manufactured by Ciba-Geigy) 3 parts by weight and "L-7002" (polyether modified dimethyl polysiloxane manufactured by Nippon Unicar) 0.1
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 39 poise (25° C.).

(Comparative Example 1) 60 parts by weight of the polymerizable unsaturated polyurethane (A) obtained in Synthesis Example 1, 20 parts by weight of tris-2-hydroxyethyl isocyanurate triacrylate, and 15 parts by weight of N-vinyl-2-pyrrolidone. and 3 parts by weight of "Irgacure 651" were mixed and dissolved at 60° C. for 1 hour to obtain a liquid ultraviolet curable resin composition having a viscosity of 38 poise (25° C.).

(Comparative Example 2) 60 parts by weight of the polymerizable unsaturated polyurethane (A) obtained in Synthesis Example 1, 20 parts by weight of tris-2-hydroxyethyl isocyanurate triacrylate, and 15 parts by weight of N-vinyl-2-pyrrolidone. , 3 parts by weight of "Irgacure 907" and 0.1 part by weight of "L-45" (dimethylpolysiloxane manufactured by Nippon Unicar Co., Ltd.) were mixed and dissolved at 60°C for 1 hour, but "L-45" did not dissolve and the mixture remained uniform. A liquid ultraviolet curable resin composition was not obtained.

The viscosity at 25°C and the coefficient of dynamic friction at 23°C of the ultraviolet curable resin compositions for coating optical fibers obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were measured, and the results are shown in Table 1. Ta. The numbers shown in the composition column are the blended amounts, and the blended amounts are shown in parts by weight.

[0049] The surface tack of a cured product of an ultraviolet curable resin composition is a perceptual amount and is therefore difficult to quantify. Therefore, it was decided to evaluate the magnitude of surface tack using the coefficient of dynamic friction, and the method for measuring the coefficient of dynamic friction is shown below.

(Method for Measuring Coefficient of Dynamic Friction) Each composition was coated on a glass plate with a film thickness of 200±20 μm, and irradiated with ultraviolet rays at 200 mJ/cm 2 in a nitrogen atmosphere using a metal halide lamp (lamp output 2 kW). Prepare a film-like sample with a smooth surface. ASTM-D-1894-
The coefficient of dynamic friction between the cured film and the sliding piece was measured according to the 63 standard. As the sliding friction test jig, [U-785] manufactured by Orientech was used. The dimensions of the sliding piece are length 63
．． It was 5 mm wide, 63.5 mm wide, and 6.4 mm high, and weighed 200±5 g. In addition, the sliding speed is 100mm
/ minute.

[0051]

[Table 1]

[0052]

[Operation] From the results shown in Table 1, it is clear that the coefficient of kinetic friction of the cured product made of the UV-curable resin composition for coating optical fibers containing the polyether-modified dimethylpolysiloxane of Examples 1 and 2 is small; It can be seen that the optical fiber coated with the curable resin composition and the tape-structured optical fiber do not come into close contact with each other. Therefore, the ultraviolet curable resin composition for coating optical fibers of the present invention is excellent as an ultraviolet curable secondary coating material and tape material. It can be seen that the cured product made of the UV-curable resin composition of Comparative Example 1 had a large coefficient of kinetic friction and was unsuitable as a UV-curable secondary coating material and tape material. Comparative Example 2 shows that dimethylpolysiloxane is not dissolved in an ultraviolet curable resin composition for coating optical fibers containing polymerizable unsaturated polyether polyurethane as a main component.

[0053]

Effect of the invention: The surface tack of the cured product of the UV-curable resin composition for coating optical fibers containing the polymerizable unsaturated polyether polyurethane and polyether-modified dimethylpolysiloxane of the present invention is small, and the UV-curable secondary coating is Excellent as material and tape material. Furthermore, the ultraviolet curable resin composition for coating optical fibers of claim 2 further reduces the surface tack of the cured product by containing a photopolymerization initiator having a maximum molecular extinction coefficient of 500 or more in the ultraviolet region. can be done.

Claims (3)

[Claims] Claim 1: (1) A polymerizable unsaturated polyurethane obtained by reacting (a) a polyether polyol, (b) a vinyl monomer having a hydroxyl group, and (c) a polyisocyanate, (2) a polyether-modified dimethylpolysiloxane. and (3) an ultraviolet curable resin composition for coating an optical fiber, comprising a photopolymerization initiator. 2. The ultraviolet curable resin composition for coating an optical fiber according to claim 1, which contains a photopolymerization initiator having a maximum molecular extinction coefficient of 500 or more in the ultraviolet region. [Claim 3] The photopolymerization initiator is 2-methyl-1-{4
-(methylthio)phenyl}-2-morpholinopropanone-1,2-benzyl-2-dimethylamino-1-(4
-morpholinophenyl)-butanone-1 and 2,4,6
2. The ultraviolet curable resin composition for coating an optical fiber according to claim 1, wherein the composition is a compound selected from the group consisting of -trimethyl-benzoyldiphenylphosphine oxide.