JPH02117910A - Photo-setting resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition suitable as a coating material of optical fiber showing excellent light transmission characteristics, having high reliability, comprising a urethane modified (meth)acrylate, monofunctional (meth) acrylate and a specific monoacrylate. CONSTITUTION:(A) 30-60 pts.wt. urethane modified (meth)acrylate prepared by reacting (i) a polyisocyanate compound with (ii) a polyhydroxy compound having >=1,000 molecular weight and (iii) an unsaturated monohydroxy compound containing both one hydroxyl group and (meth)acryloyl group is blended with (B) 40-30 pts.wt. monofunctional (meth)acrylate compound and (C) 30-10 pts.wt. monoacrylate shown by the formula so as to make 100 pts.wt. total amounts of the components A-C to give the aimed composition. The component C is preferably obtained by adding hydroxyethyl ethyl acrylate to n-butyl isocyanate.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a photocurable resin composition, and particularly to a secondary coating material for optical transmission glass fibers (herein abbreviated as optical fibers). In particular, the present invention relates to an optical fiber coating material that has excellent adhesion to optical fibers, has a low elastic modulus, has small temperature dependence of the elastic modulus, and has excellent heat resistance and water resistance.

[Conventional technology]

Optical fibers are generally coated with a polymeric material immediately after spinning to maintain physical and chemical protection from the external environment and transmission properties. As these coating materials, thermosetting resins such as silicone resins, and ultraviolet curing resins such as urethane acrylates, epoxy acrylates, and polybutadiene acrylates have been used.

[Problems to be Solved by the Invention] However, although silicone resin has the advantage of having a low Tg, a low elastic modulus, and a small temperature dependence of the elastic modulus, it has a slow curing speed due to thermosetting, which makes it difficult to produce optical fibers. There are disadvantages that are inferior to gender. In addition, UV-curable resins such as urethane acrylate, epoxy acrylate, and polybutadiene acrylate have the advantage of fast curing speed, but have the disadvantage that their elastic modulus is highly dependent on temperature, or that they have poor heat resistance and water resistance. etc., and the performance as an optical fiber coating material, which requires high reliability, is not fully satisfied.

The purpose of the present invention is to improve adhesion with optical fibers, have a low elastic modulus, have small temperature dependence of the elastic modulus, and have heat resistance.
It is an object of the present invention to provide a photocurable resin composition that exhibits excellent light transmission characteristics, provided that it has good water resistance, and is suitable as a primary coating material for optical fibers that require high reliability.

[Means to solve the problem]

As a result of various studies, the present inventors found that urethane modified (meth)
A composition consisting of acrylate, a monofunctional (meth)acrylate compound, and a monoacrylate with a specific structure has excellent adhesion to optical fibers, has a low elastic modulus, has little temperature dependence of the elastic modulus, and has excellent heat resistance and water resistance. Furthermore, it was discovered that an optical fiber coated with this composition exhibits excellent transmission characteristics, leading to the present invention.

That is, the present invention provides: A) (a) a polyisocyanate compound, (b) a polyhydroxy compound having a molecular weight of 1000 or more, and (c) an unsaturated compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule. Urethane-modified (meth)acrylate obtained by reacting three monohydroxy compounds 30~
60 parts by weight, B) 40 to 30 parts by weight of a monofunctional (meth)acrylate compound, and C) Formula CL"CHCOOCLCLOCONHCL
This is a photocurable resin composition comprising 30 to 10 parts by weight of a monoacrylate represented by CLCLCL (I) (the total amount of A), B) and C) being 100 parts by weight).

The expression urethane-modified (meth)acrylate as used in the present invention means both acrylates and methacrylates. Others (meth)acryloyl group, (meth)acrylic acid, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate monofunctional (
The same applies to expressions such as meth)acrylate and polyfunctional (meth)acrylate.

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

A) urethane-modified (meth)acrylate used in the present invention refers to (a) a polyisocyanate compound, (
It is a compound obtained by reacting b) a polyhydroxy compound and (c) an unsaturated monohydroxy compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule.

As the above-mentioned (a) polyisocyanate compound,
A substance having two or more isocyanate groups in the molecule,
Specific examples include diisocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-1-lylene diisocyanate, diphenylmethane-4,4°-diisocyanate, xylylene diisocyanate, naphthylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate; Examples include dimers and trimers of these diisocyanate compounds, as well as compounds obtained by reacting these diisocyanate compounds with polyols such as ethylene glycol, hexanediol, trimethylolpropane, glycerin, and hexanetriol under conditions in which isocyanate groups are in excess. . These polyisocyanate compounds may be used alone or in combination of two or more.

The polyhydroxy compound (b) mentioned above is a compound having two or more hydroxyl groups in the molecule, and has a molecular weight of 000 or more, preferably 2000 to 4000.

Specific examples include polyether polyols such as polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol, propylene oxide-tetrahydrofuran copolymer, adipic acid, dodecanedicarboxylic acid, the aforementioned polyols, diethylene glycol, polypropylene glycol, etc. Examples include polyester polyols obtained by the reaction, polycaprolactone polyols, and saturated polyolefins having terminal hydroxyl groups. If the molecular weight of these polyhydroxy compounds is less than 0,000, the elastic modulus becomes high, which is not preferable in terms of transmission characteristics.

Examples of the unsaturated monohydroxy compound (c) mentioned above include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, and N-hydroxymethyl (meth)acrylamide. (Poly)alkylene glycol mono such as N-hydroxyalkyl (meth)acrylamide, ethylene glycol mono(meth)acrylate, diethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate Examples include (meth)acrylate, trimethylolpropane di(meth)acrylate, equimolar reaction products of glycidyl (meth)acrylate and (meth)acrylic acid, and these may be used alone or in combination of two or more. Can be done.

The amounts of (a), (b) and (c) are usually 1.1 to 2.0 equivalents of al per 1 equivalent of (b), and 0.1-1.
2 equivalents, preferably (b) relative to 1 equivalent
(a) 1.2-1.8 equivalent, (c) 0.2-1.0
It is equivalent.

Furthermore, the order of the reactions (a), (b), and (c) is not particularly limited; for example, (a), (b), (
There are three methods: reacting c) at the same time, reacting (a) and (b) and then reacting (c), or reacting (a) and (c) and then reacting (b). The reaction temperature is about 20°C to 150°C. At this time, to accelerate the reaction, a usual urethanization reaction catalyst such as triethylamine or dibutyltin dilaurate is used,
Further, in order to prevent polymerization of the (meth)acryloyl group, a common radical polymerization inhibitor such as benzoquinone, hydroquinone, hydroquinone monomethyl ether, catechol, or phenothiazine may be used, or air or oxygen may be introduced into the reaction system.

The terminal of the urethane-modified (meth)acrylate of the present invention is usually a (meth)acryloyl group, but it may also be a -partial isocyanate group or a hydroxyl group.
The proportion of meth)acrylate used is 30 to 60 parts by weight; if it is less than 30 parts by weight, the viscosity of the composition will be low and coating will be difficult during work, and the toughness of urethane-modified (meth)acrylate will be insufficient, resulting in poor heat resistance. , inferior in terms of water resistance. Furthermore, if the amount exceeds 60 parts by weight, the viscosity of the composition becomes high, making coating difficult during operation.

B) Monofunctional (meth)acrylate compound used in the present invention is an acrylate compound added to adjust the Tg, elastic modulus, viscosity, etc. of the composition, and includes, for example, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, phenoxyethyl (meth)acrylate, ethylene glycol nonylphenyl ether (meth)acrylate, tripropylene glycol nonylphenyl ether (meth)acrylate, (meth)acrylic acid adduct of butyl glycidyl ether, tetrahydrofurfuryl alcohol caprolactone (meth)acrylate of adduct; (meth)acrylate of 2-ethylhexyl alcohol ethylene oxide adduct;
Hydroxyethyl (meth)acrylate, Hydroxypropyl (meth)acrylate, Cyclohexyl (meth)
Monofunctional (acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate
Among the meth)acrylates, acrylate compounds with a low Tg (approximately -25°C to -50°C) are desirable, and these may be used alone or in combination of two or more. Also, this B
) desirably does not have a urethane bond.

In addition to B) above, if necessary, ethylene glycol di(meth)acrylate, neobentyl glycol di(
Polyfunctional (meth)acrylate such as meth)acrylate, 1,4-butanediol di(meth)acrylate, bisphenol A/ethylene oxide adduct di(meth)acrylate, trisacryloyloxyethyl isocyanurate, trimethylolpropane tri(meth)acrylate, etc. ) Acrylate may be used within a range that does not impair the effects of the present invention.

If the proportion of the acrylate compound used is less than 30 parts by weight, the Tg of the composition will be high, the temperature dependence of the elastic modulus will be large, and the transmission characteristics will be poor. On the other hand, if the amount exceeds 40 parts by weight, the viscosity of the composition decreases, making coating difficult.

The monoacrylate represented by C) formula [I] used in the present invention is an adduct of hydroxyethyl acrylate of n-butyl isocyanate, and a commercially available product is Niraso Cure t1M-1 manufactured by Nippon Soda Co., Ltd. If the proportion of monoacrylate used is less than 10 parts by weight, it will have no effect on the adhesion with the optical fiber, and if it exceeds 30 parts by weight, the Tg of the composition will increase and the temperature dependence of the elastic modulus will increase. Poor transmission characteristics.

The composition of the present invention may contain various additives such as a photopolymerization initiator, a silane coupling agent, an antioxidant, and a filler, if necessary.

The photopolymerization initiator is not particularly limited, but examples include benzoyl, benzoin methyl ether, benzoin isopropyl ether, benzoin butyl ether, benzyl, benzophenone, 2-hydroxy-2-methylpropiophenone, 2.2-jethoxyacetophenone,
Benzyl dimethyl ketal, anthraquinone, chloranthraquinone, ethyl anthraquinone, butylanthraquinone, diphenyl sulfide, dithiocarbamate, 2-chlorothioxanthone, a-ri-tetramethylnaphthaleneanthracene, 3.3°14,4°-tetra-(1
-butylperoxycarbonyl)benzophenone, 2
, 4.6-1-limethylbenzoyldiphenylphosphine oxide, and the like. These may be used alone or in combination of two or more. Further, these photopolymerization initiators may be used in combination with amines such as Michler's ketone, triethylamine, alkylmorpholine, etc. The proportion of these photopolymerization initiators used is usually 1% of the resin composition of the present invention.
The content is at least 10% by weight and less than 10% by weight, preferably from 2% to 5% by weight.

The composition of the present invention is useful, for example, as a coating material for silica glass optical fibers containing silica as a main component. An example of its use is shown below.

The quartz base material is heated to about 2000℃ and the drawing speed is 60~3.
Optical fibers are obtained by spinning at 00 m/min to an outer diameter of 125±3μ. The optical fiber immediately after spinning is passed through a bath containing a coating material, and the outer diameter after curing is usually 200 to 300μ.
Preferably, the thickness is adjusted to 250μ. A typical method for curing is to irradiate the coated optical fiber with ultraviolet rays in a nitrogen gas atmosphere using a high-pressure mercury lamp.

[Example] The present invention will be described below with reference to Synthesis Examples, Examples, and Comparative Examples.

Synthesis Example 1 300 parts by weight of polyoxytetramethylene glycol with a molecular weight of 2000, 39 parts by weight of 2,4-tolylene diisocyanate
．． 2 parts by weight was charged into a flask equipped with a 500 mβ stirrer and a thermometer, and the reaction was carried out at 70°C for 4 hours under a nitrogen stream. Acrylay) 1B, 3 parts by weight,
0.2 parts by weight of hydroquinone and 0.1 parts by weight of dibutyltin dilaurate were added, and the reaction was further carried out at 70°C for 5 hours while bubbling air into the reaction solution, resulting in urethane modification (
Meth)acrylate (8-1) was synthesized.

Synthesis Example 2 Problene oxide-tetrahydrofuran copolymer with a molecular weight of 2000 (manufactured by Hodugaya Chemical, PPTG 2000)
300 parts by weight, 2.4-tolylene diisocyanate 3
When 9.2 parts by weight was charged into a flask equipped with a 500 mρ stirrer and a thermometer and reacted at 70° C. under a nitrogen stream for 5 hours, the NGO group content reached the initial percentage. Next, 18.3 parts by weight of hydroxyethyl acrylate, 0.2 parts by weight of hydroquinone, and 01 parts by weight of dibutyltin dilaurate were added to this reaction solution, and the reaction was further carried out at 70° C. for 5 hours while bubbling air into the reaction solution. Modified (meth)acrylate (A-2) was synthesized.

Synthesis Example 3 Polyoxytetramethylene glycol 3 with molecular weight 850
00 parts by weight, 2.4-tolylene diisocyanate 1-9
When 2.1 parts by weight was charged into a flask equipped with a 500 mβ stirrer and a thermometer and reacted for 4 hours at 70°C under a nitrogen stream, the NGO group reached its initial level. Next, 43 parts by weight of hydroxyethyl acrylate was added to this reaction solution.
0.2 parts by weight of hydroquinone and 0.1 parts by weight of dibutyltin dilaurate were added, and the reaction was further carried out at 70° C. for 5 hours while bubbling air into the reaction solution to synthesize urethane-modified (meth)acrylate (A-3).

Examples 1 to 4 and Comparative Examples 1 to 3 Add the specified urethane-modified (meth)acrylate, acrylate compound, monoacrylate, and photopolymerization initiator to the formulation contents (parts by weight) shown in Table 1 and mix thoroughly. The mixture was stirred to obtain each coating material.

Evaluation of coating materials: The coating materials obtained in Examples and Comparative Examples were evaluated as follows, and the results are shown in Table-2. Note that the evaluation was based on the method described below.

1) 180° Peeling Test A coating material was applied to a thickness of 100 to 150 μm on a glass plate and irradiated with ultraviolet rays of 80 mJ/am 2 using a high-pressure mercury lamp of 80 W/cI 11 in a nitrogen atmosphere to create a cured film. Next, 18 of the cured film from this glass plate
The 0° peel strength was measured using an Instron tester at a tensile speed of 100 mm/min.

2) 2.5% elastic modulus A cured film was prepared in the same manner as the 180° peel test. Next, remove this film from the glass plate and
The tensile modulus at 23°C and -40°C was measured according to IS-7113.

3) Heat resistance and water resistance A cured film was prepared in the same manner as the 180° peel test. Next, this film is peeled off from the glass plate, and if it is heat resistant, it is placed in a constant temperature bath kept at 80 degrees Celsius, or if it is water resistant, it is immersed in warm water kept at 80 degrees Celsius, and cured after 30 days. The film was taken out, tensile strength elongation 25% modulus of elasticity was measured according to JIS K-7113, and the retention rate was calculated using the measured value (initial value) before immersion in a thermostatic bath or hot water as 1.

4) Transmission loss 300m Outer diameter spun at a speed of 7 minutes + 25. Immediately after spinning, the coating materials obtained in the Examples and Comparative Examples were applied to the optical fiber M so that the outer diameter after curing would be 250 mm, and the coating materials were immediately coated under a nitrogen atmosphere using a 3.2 kW high-pressure mercury lamp. hardened with. These coated optical fibers thus obtained were heated at 23°C and -44°C at a wavelength of 1.311 m.
Optical transmission loss at 0°C was measured.

Effect of the Invention 1 As explained above, the composition of the present invention has improved adhesion to optical fibers, has a low elastic modulus, has little temperature dependence of the elastic modulus, and has good heat resistance and water resistance. In particular, it exhibits excellent optical transmission characteristics and is suitable as a primary coating material for optical fibers that require high reliability.

Applicant: Mitsui Toatsu Chemical Co., Ltd. Agent Patent Attorney Tadashi Kukai

Claims (1)

[Scope of Claims] A) (a) a polyisocyanate compound, (b) a polyhydroxy compound having a molecular weight of 1000 or more, and (c) an inorganic compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule. 30 to 60 parts by weight of urethane-modified (meth)acrylate obtained by reacting three saturated monohydroxy compounds, B) 40 to 30 parts by weight of a monofunctional (meth)acrylate compound, and C) formula CH_2=CHCOOCH_2CH_2OCON
30 to 10 parts by weight of monoacrylate represented by HCH_2CH_2CH_2CH_3 [I] (However, A),
The total amount of B) and C) is 100 parts by weight).