JPS63150351A - Ultraviolet-curable resin composition - Google Patents

Abstract

PURPOSE:To provide an ultraviolet-curable resin compsn. which releases a reduced amount of hydrogen gas and is suitable for use in coating optical fibers, by adding a phenolic stabilizer to a resin blend. CONSTITUTION:A resin compsn. is obtd. by adding 0.05-3.0pts.wt. phenolic stabilizer to 100pts.wt. resin blend. The phenolic stabilizer is a compd. having an effect of inhibiting radical chain transfer, such as a heat polymn. inhibitor, a phenolic antioxidant, etc. Examples thereof are butylhydroxyanisole, 2,6-di-6- butyl-p-cresol, etc. The resin blend consists of pref. an oligomer having a polymerizable carbon-to-carbon double bond at the terminal of its polymer chain and a compd. having at least one polymerizable carbon-to-carbon double bond. Examples of the oligomer and the compd. are urethane acrylate, phenoxyethyl (meth)acrylate, etc.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an ultraviolet curable resin composition that suppresses the generation of hydrogen gas, and more specifically, when used as a coating material for an optical fiber, the composition suppresses the generation of hydrogen gas. The present invention relates to an ultraviolet curable resin composition that can improve transmission loss characteristics due to hydrogen gas.

[Prior art]

Conventionally, the outer peripheral surface of an optical fiber made of -C quartz glass is coated with an ultraviolet curable resin composition or the like in order to prevent damage to the glass fiber and to prevent microbending caused by external force.

The transmission loss of this type of coated optical fiber is extremely good initially, but over time hydrogen gas generated from the coating material diffuses into the optical fiber, which is thought to be due to absorption of hydrogen molecules1. 24 μm, 1 thought to be absorption of 5iOH
−39, ljm , Ge0) 1 which is considered to be the absorption of 1
, 41 μm, and other wavelength bands.

[Purpose of the invention]

The present invention was made to improve the transmission loss characteristics of an optical fiber coating material, that is, a coated optical fiber. The purpose is to provide a curable resin composition.

[Structure of the invention]

Therefore, in the present invention, based on 100 parts by weight of the resin compound,
The gist of the invention is an ultraviolet curable resin composition containing 0.05 to 3.0 parts by weight of a phenolic stabilizer.

Hereinafter, the configuration of the present invention will be explained in detail.

(1) Resin formulation.

Any ordinary ultraviolet curable type may be used (there are no particular restrictions. For example, oligomers having a polymerizable carbon-carbon double bond at the end of the polymer chain, and at least one in each molecule) It may consist of a compound having a polymerizable carbon-carbon double bond.

Examples of the oligomers include urethane acrylate, epoxy acrylate, polyether acrylate, polyester acrylate, and polybutadiene acrylate. In addition, examples of compounds having at least one polymerizable carbon-carbon double bond in one molecule include phenoxyethyl (meth)acrylate, lauryl (meth)acrylate,
Acrylate, 2-ethylhexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, polyethylene glycol (meth)acrylate, neopentyl glycol diacrylate, trimethylpropane triacrylate
Examples include (meth)acrylate, pentaerythritol tri(meth)acrylate, N-vinylpyrrolidone, and acryloylmorpholine.

Photopolymerization initiators (e.g., benzoin methyl ether, benzoin isopropyl ether, benzophenone, benzyl dimethyl ketal, anthraquinone, 2-2 diethoxyacetophenone, 2-methylthioxanthone, 1-
hydroxycyclohexyl phenyl ketone, etc.) are also included. Furthermore, if necessary, polymerization accelerators, anti-aging agents,
Leveling agents, antifoaming agents, etc. can also be used.

(2) Phenol stabilizer.

Use phenolic stabilizers alone or in combination. Phenol stabilizers are phenolic antioxidants, thermal polymerization inhibitors, etc., and have the effect of inhibiting radical chains. For example, butylhydroxyanisole, 2.
6-di-t-butyl-para-cresol, 2,5-di-
t-Amylhydroquinone, 2.5-di-t-butylhydroquinone, 4.4'-thio-bis(4-methyl-6
-t-butylphenol), 4,4-thio-bis(3-
methyl-6-t-butylphenol), 4,4'-thio-bis(2-methyl-6-t-butylphenol), 2
．． 2-thio-bis(4-methyl-6-t-butylphenol), 4,4-butylidene-bis(3-methyl-5-
t-butylphenol), 2,2'-methylene-bis(
4-methyl-6-t-butylphenol), 4,4-methylene-bis(2,6-di-t-butylphenol),
2.4-dimethyl-6-t-butylphenol, 2.4
．． 6-tri-t-butylphenol, 4-hydroxy-
Methyl-2,6-di-t-butylphenol, 2,6-
Di-t-butylphenol, 2,6-bis(2'-hydroxy-3'-t-butyl-5'-methyl-hensyl)
4-Methyl-phenol, 2,6-di-t-butyl-α
-dimethylamine-p-cresol, 2,6-di-t-
Butyl-varethylphenol, 2,2'-isobutylidene-bis(4,6-dimethylphenol), t-butylcatechol, 2,4.5-trihydroxybutyrophenone, tri(3,5-di-t-butyl) -4-hydroxyphenyl)isocyanurate, 1.3.5-)dimethyl-2,4,6-1su(3,5-di-t-butyl-4
-hydroxy-benzyl)benzene, N,N-hexamethylene-bis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide, 2,2-methylene-bis(4
-methyl-6-cyclohexylphenol), 1,1.
3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, bis(3-methyl-4-hydroxy-5-butylbenzyl)sulfide, 2,4-bis-(n-octylthio)- 6-(4-hydroxy-3
, 5-di-t-butylanilino)1.3. -5-1-Ryazine, 3,5-di-t-butyl-4-hydroxy-henzylphosphonate diethyl ester, triethylene glycol-bis(3-(3-t-butyl-5-methyl-4 -hydroxyphenyl)propionate], pentaerythrityl-tetrakis[3-(3,5-di-t
-butyl-4-hydroxyphenyl)propionate]
, n-octadecyl-3-(4'-hydroxy-3',
5'-di-t-butylphenyl)propionate, 2,
2-thio[diethyl-bis-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], hexanediolbis(3-(3,5-di-butyl-4-hydroxyphenyl) ) propionate], catechol, hydroquinone, 1-butylhydroquinone, paramethoxyphenol, methylhydroquinone, etc.

Further, it is preferable that the reaction rate of the phenolic stabilizer for inhibiting radical chains is lower than the radical polymerization rate of the acrylate. If the reaction rate of radical chain inhibition of the phenolic stabilizer is higher than the radical polymerization rate of the acrylate, the phenolic stabilizer will capture the radicals generated during curing by UV irradiation before proceeding with the polymerization of the acrylate. This is because the curing speed may be slowed down due to storage.

These phenolic stabilizers are added in an amount of 0.05 to 3.0 parts by weight per 100 parts by weight of the resin compound.

If the amount added is less than 0.05 parts by weight, the effect will be reduced;
．． This is because even if more than 0 parts by weight is added, the effect will not improve.

In addition, these phenolic stabilizers are used as thermal polymerization stabilizers for acrylate, and among them, hydroquinone monomethyl ether (M E HQ) and t-butyl hydroquinone are common, but the amount of these added is 10010
0 ppm (0.01 parts by weight) to 500 ppm (0.05 parts by weight). Within this range, these compounds have very little effect in suppressing hydrogen gas generation.

Examples and comparative examples are shown below.

Examples and Comparative Examples (a) Examples 1 to 6 0.5 mol of polyether polyol (PPTG-4000, manufactured by Odougaya Chemical Industry ■) was placed in a 3β four-loaf flask equipped with a stirrer, a thermometer, and a condenser. 1.02 mol of tolylene diisocyanate and 100 mol of tolylene diisocyanate for these two components.
Add heavy ftppm dibutyltin dilaurate,
The reaction was carried out at ~80°C to synthesize a urethane prepolymer. This reaction was carried out until N00% became constant at 2.0 to 2.3%. Further, 2 mol of 2-hydroxyethyl acrylate LL0 was added and the reaction was carried out at 60 to 80°C to synthesize urethane acrylate. This reaction is N00
% was 0.2% or less. Furthermore, it was confirmed by infrared absorption spectrum that the characteristic absorption band of isocyanate groups had disappeared.

To 70 parts by weight of the above urethane acrylate, 30 parts by weight of phenoxyethyl acrylate, 5 parts by weight of l-hydroxycyclohexylphenyl ketone, and 0.0 parts by weight of phenolic stabilizer.
1 to 2.0 parts by weight were dissolved and mixed to obtain an ultraviolet curable resin composition of the present invention.

(b) Comparative Example 1 30 parts by weight of phenoxyethyl acrylate and 5 parts by weight of ■-hydroxycyclohexyl phenyl ketone were dissolved and mixed in 70 parts by weight of the urethane acrylate synthesized in Examples 1 to 6, and the mixture was exposed to ultraviolet light for comparison. A curable resin composition was obtained.

Place the above resin composition on a glass plate to a thickness of 200 to 250 μm.
This coating film was then exposed to a metal halide lamp (8
0 w/cm) and 400 mJ/cJ of light irradiation was performed.

Hydrogen gas generation test: Precisely weigh 1 to 2 g of the sample prepared under the above conditions, place it in a vial with a known container, and leave it in a dryer at 100°C for 24 hours. It was introduced into chromatography and quantified using the absolute calibration curve method. The results are shown in Table 1 below (compounds are in parts by weight).

(Margin below this page) As shown in Table 1, the amount of hydrogen generated in Comparative Example 1 was 6.6 μl.
/g, but it can be seen that the amount of hydrogen generated can be reduced by adding a phenolic stabilizer as in Examples 1 to 6. A possible reason why phenolic stabilizers are so effective is that they have a radical chain inhibiting effect. When curing an ultraviolet curable resin, polymerization is carried out by irradiating ultraviolet rays to generate radicals, but even after curing is completed, the radicals remain in the cured product, so these residual radicals can absorb hydrogen. It is thought that the hydrogen is extracted and hydrogen is generated. It is thought that hydrogen generation can be suppressed by capturing residual radicals with a phenolic stabilizer.

〔Effect of the invention〕

As explained above, the cured product of an ultraviolet curable resin composition in which 0.05 to 3.0 parts by weight of a phenolic stabilizer is added to 100 parts by weight of the resin composition generates little hydrogen gas. Therefore, the present invention has the advantage of reducing the increase in optical fiber transmission loss due to generated hydrogen gas.

Claims (1)

[Claims] An ultraviolet curable resin composition in which 0.05 to 3.0 parts by weight of a phenolic stabilizer is added to 100 parts by weight of a resin compound.