JPH0432785B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a composition for coating optical communication glass fibers. (Problems to be solved by the prior art and the invention) Optical communication glass fibers protect the surface, maintain strength, and prevent microbending when external physical pressure is applied or when the operating temperature changes. To prevent this, it is common practice to melt the preform and immediately coat it with a coating material with special properties after drawing. Special properties include (1) flexibility, (2) excellent long-term reliability such as heat resistance and hydrolysis resistance, (3) small change in physical properties due to temperature changes, (4)
(5) It is liquid at room temperature and has excellent workability. Conventionally, RTV silicone resin has been used as a coating composition for optical communication glass fibers, but
Due to the slow curing properties of silicone resins, it is difficult to increase productivity, and research has been carried out on active energy ray-curable coating compositions to overcome this drawback, but a fully satisfactory coating composition has not been obtained. . Conventional flexible active energy ray-curable coating compositions have been made by blending a high viscosity prepolymer with a large amount of radiation curable monomers with a low glass transition temperature and irradiating the composition with active energy rays. Curable monomers have slow curability, and therefore conventional flexible coating compositions have the disadvantage of slow curability. Furthermore, improved coating compositions containing polyether-based urethane acrylate prepolymers are known, but they still have problems that hinder their practical application. That is, it is possible to obtain flexibility with a coating composition containing a urethane acrylate prepolymer using a homopolymer such as polyethylene glycol or polytetramethylene glycol, but it has high crystallinity and therefore does not form in a solid state in winter. It has the disadvantage that it tends to harden easily, has poor workability, and has a high viscosity, so it is necessary to incorporate a large amount of radiation-curable monomer in the same way as above, resulting in slow curing. Furthermore, coating compositions containing urethane acrylate prepolymers using polypropylene glycol have low viscosity, but have drawbacks such as slow curing and difficulty in obtaining the required mechanical properties. was. (Means for Solving the Problems) As a result of intensive studies to solve these problems, the present inventors found that when a specific polyether polyol-based urethane acrylate prepolymer is used,
We have discovered that it is possible to obtain a composition for coating optical communication glass fibers that is highly flexible, has excellent long-term reliability, shows little change in physical properties due to temperature changes, has fast curing properties, is liquid at room temperature, and has excellent workability. , we have completed the present invention. That is, the present invention comprises a polyether polyol compound (a) obtained by ring-opening copolymerization of two or more types of ionically polymerizable cyclic compounds, a polyisocyanate compound (b), and a hydroxyl group-containing (meth)acrylate (c). This is a composition for optical communication glass fiber, characterized in that it contains as an essential component a polyether polyol-based urethane (meth)acrylate prepolymer (A) obtained by reacting with the present invention. Although the present invention will be specifically and detailedly described below, the present invention is neither exhaustive nor restricted. The polyether polyol compound (a) [hereinafter referred to as polyether polyol compound (a)] obtained by ring-opening copolymerization of two or more types of ionically polymerizable cyclic compounds used in the present invention is a polyhydric polymerization initiator, For example, by the already known ring-opening copolymerization in which ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, or pentaerythritol is reacted with a molar excess of an ionically polymerizable cyclic compound. manufactured by
There are no particular limitations on the catalyst that can be used in this copolymerization reaction, and any catalyst such as cationic, anionic, or coordinating anionic catalysts may be used. Further, there are no restrictions on polymerization conditions such as temperature, pressure, solvent composition, etc. The ionically polymerizable cyclic compound mentioned here is
Ethylene oxide, propylene oxide, butene-1-oxide, isobutene oxide, 3,3-
Cyclic ethers such as bischloromethyloxetane, tetrahydrofuran, dioxane, trioxane, tetraoxane, cyclohexene oxide, styrene oxide, epichlorohydrin;
Cyclic imines such as ethyleneimine; cyclic lactones such as β-propiolactone and glycolic acid lactide; cyclic siloxanes such as dimethylcyclopolysiloxane; cyclic ether compounds having a radiation-crosslinkable double bond in the same molecule; For example, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, allyl glycidyl carbonate, butadiene monoxide, isoprene monoxide, vinyl oxetane, vinyl tetrahydrofuran, vinyl cyclohexene oxide; although there are other parts that overlap with the above-mentioned compounds, the monoalcohol glycidyl Examples include ethers or glycidyl esters of monocarboxylic acids, such as phenyl glycidyl ether, butyl glycidyl ether, and benzoic acid glycidyl ester. The combination of two or more ionically polymerizable cyclic compounds used in producing the polyether polyol compound (a) includes a combination of two or more cyclic ethers, a cyclic ether and a cyclic imine, a cyclic lactone, A good combination is one or more cyclic compounds selected from cyclic siloxanes and cyclic ether compounds having a radiation-crosslinkable double bond in the same molecule. Among them, 5% by weight or more of cyclic ethers in the copolymerization component, Preferably, when the content is 10% by weight or more, it becomes amorphous and becomes liquid at room temperature, and has excellent workability. Furthermore, 5 to 95% by weight or more of tetrahydrofuran, preferably 20 to 95% by weight
Containing 80% by weight or more is particularly preferred because it improves the long-term reliability of the resulting composition and reduces changes in physical properties due to temperature changes. The molecular weight of the polyether polyol compound (a) is
It is usually in the range of 200 to 5,000, and if it is less than 200, a good coating film cannot be obtained, and if it exceeds 5,000, the curing speed will be extremely slow, which is not preferred. Among them, those with a molecular weight of 400 to 4000 provide a flexible coating film,
Moreover, it is particularly suitable because a product with good curability can be obtained. Polyisocyanate compounds that can be used in the present invention
(b) is a substance that is publicly known in this field,
Suitable diisocyanate compounds include, for example, 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,
4,4-trimethylhexamethylene diisocyanate, 1,4-hexamethylene diisocyanate, 4,4-methylene-bis(cyclohexyl isocyanate), bis(2-isocyanatoethyl) fumarate, 4,4'-diphenylmethane diisocyanate, 6- Isopropyl-1,3-phenyl diisocyanate, dielylene diisocyanate, 4,4'-diphenylpropane diisocyanate, 3,5,5-trimethyl-3-isocyanate-methyl-cyclohexane diisocyanate, 1,3-xylylene diisocyanate, 1,
Examples include 4-xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, and compounds of triisocyanate or higher, such as "Barnock D-750, D-800, D-
802, DN-950” [Dainippon Ink Chemical Industry Co., Ltd.
Products Co., Ltd.], “Dasmodule L-75, N-75,
FL, IL, HL "[The above products are manufactured by Bayer AG in West Germany], "Coronate L-75, 2030, 2031, HL"
[The above products are manufactured by Nippon Polyurethane Industries Co., Ltd.] "Takenate D-102, D-202, D-204, D-110N, D
-160N” [all products manufactured by Takeda Pharmaceutical Co., Ltd.], and “DULANATE 24A-100, 24A-90CX” [all products manufactured by Asahi Kasei Industries, Ltd.]. There is no problem in using these polyisocyanate compounds in combination in any proportion as necessary. Further, as the hydroxyl group-containing (meth)acrylate compound (c) that can be used in the present invention, for example, 2-
Hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 1,6
- hexanediol mono(meth)acrylate,
Neopentyl glycol mono(meth)acrylate, 1,4-butanediol mono(meth)acrylate, 4-hydroxycyclohexyl(meth)
Acrylate, trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, etc., butyl glycidyl ether, phenyl glycidyl ether, It can also include a hydroxyl group-containing compound obtained by an addition reaction between a glycidyl group-containing compound such as allyl glycidyl ether or glycidyl (meth)acrylate and (meth)acrylic acid. Polyether polyol-based urethane (meth)acrylate prepolymer (A) used in the present invention (hereinafter referred to as urethane (meth)acrylate prepolymer
(A)] is a polyether polyol compound (a)
Hydroxyl groups and polyisocyanate compounds (b) contained in
It is obtained by reacting the isocyanate groups contained in the reaction product, and then reacting the isocyanate groups remaining in the reaction product with the hydroxyl groups of the hydroxy group-containing (meth)acrylate compound (c). This reaction is not carried out in a particular order, and it is also possible to carry out the reaction by charging all at once or in the reverse order to the above. The usage ratio of each component (a), (b) and (c) above is 1 hydroxyl group contained in the polyether polyol compound (a).
Normally polyisocyanate compound (b) relative to the equivalent
The isocyanate group contained in is 1.1 to 2.0 equivalents, and the hydroxy group-containing (meth)acrylate compound (c) is
The proportion is 0.5 to 1.5 equivalents. Although this reaction is known and publicly used by researchers in this field, the reaction temperature is 20 to 90°C, preferably 30 to 80°C, and the reaction temperature is 20 to 90°C, preferably 30 to 80°C. The presence or absence of a reactive diluent or the like that can be copolymerized with the urethane acrylate prepolymer (A) used in the invention does not impose any restrictions on the invention. The coating composition of the present invention contains, as a resin component, in addition to the essential constituent urethane (meth)acrylate prepolymer (A), for the purpose of forming a practical optical communication glass fiber coating composition. Furthermore, if necessary, other radiation radical crosslinkable prepolymers (B), reactive diluents (C), and compounds with little or no active energy ray curability (D)
can be used. The radiation radical crosslinkable other prepolymers (B) mentioned here include, for example, () polyester mono- and poly(meth)acrylates, () epoxy mono- and poly(meth)acrylates, () urethane acrylate prepolymers (A) Other polyurethane mono- and poly(meth)acrylates other than ()
polyamide mono and poly(meth)acrylates,
() Polysiloxane mono and poly(meth)acrylate, () side chain and/or terminal (meth)
Vinyl-based or diene-based low polymers having acryloyloxy groups, () modified products of the above-mentioned polymerizable (meth)acrylates, () allyl compounds, etc., among which the above-mentioned (), (), (), ( )
The compounds of and () are particularly preferred. Note that one or more types of other radical crosslinkable prepolymers can be added. Further, the so-called low viscosity radiation radical crosslinkable reactive diluent (C) for adjusting the viscosity that can be used in combination is well known to those skilled in the art, such as (meth)acrylic acid, Methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, decyl (meth)acrylate, stearyl (meth)acrylate, n-hexyl (meth)acrylate Acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate,
Cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol ( meth)acrylate, methoxypolypropylene glycol (meth)acrylate,
Phenoxyethyl (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, alkylphenoxyethyl (meth)acrylate, alkylphenoxypolyalkylene glycol (meth)acrylate, 2-hydroxy-3
-Phenyloxypropyl (meth)acrylate, tetrahydrofurfuryloxypolyalkylene glycol (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyalkyl (meth)acrylate, dicyclopentenyloxypolyalkylene glycol (meth)acrylate Acrylate, 2-hydroxyalkyl (meth)acryloyl phosphate, vinyl acetate, vinyl propionate, polyfluoroalkyl (meth)acrylate, ethylene glycol di(meth)acrylate, propanediol di(meth)acrylate, butanediol di(meth)acrylate, ) acrylate, neopentyl glycol di(meth)
Acrylate, hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol ester di(meth)acrylate, trimethylolpropane di(meth)acrylate, bisphenol Di(meth)acrylate of ethylene oxide adduct of A, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate,
Examples include general-purpose products such as THEIC di(meth)acrylate and THEIC tri(meth)acrylate, and further examples include carbamoyloxyalkyl(meth)acrylate and caprolactone-modified (meth)acrylate. Note that one or more types of reactive diluent (C) can be added. Specific examples of compounds (D) with little or no active energy ray curability include epoxy resins, liquid polybutadiene, liquid polybutadiene derivatives, liquid chloroprene, liquid polypentadiene, dicyclopentadiene derivatives, saturated polyester oligomers, polyether oligomers, liquid Examples include polyamide, polyisocyanate oligomer, xylene resin, ketone resin, petroleum resin, fluorine-based oligomer, silicone-based oligomer, and polysulfide-based oligomer. The urethane (meth)acrylate prepolymer (A) used in the present invention is used as an essential component of the optical communication glass fiber coating composition of the present invention, and is a component of the above-mentioned (A), (B), ( It is usually contained in the range of 10 to 100% by weight in 100% by weight of the resin component consisting of C) and (D), and the coating composition has excellent flexibility and long-term reliability, and its physical properties change with temperature changes. 20 to maintain and improve excellent hardenability.
It is preferably contained in a range of 100% by weight. In the present invention, components (B), (C), and (D), which are used as resin components together with the urethane (meth)acrylate prepolymer (A), are (A), (B), (C), and ( D)
Usually 0 to 70% by weight in 100% by weight of the resin component consisting of
They are preferably contained in an appropriate amount of 0 to 50% by weight. The coating composition of the present invention is cured by heat and/or active energy rays. In the case of thermal curing, a radical polymerization initiator is used. Specific examples of the radical polymerization initiator include benzoyl peroxide, t-butyl perbenzoate, etc., and it is usually used in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the above components (A), (B), and (C). part is added. Active energy rays include ultraviolet rays, electron beams, α
When using ultraviolet rays, it is preferable to include a photopolymerization initiator and/or a photosensitizer in the coating composition. When using ionizing radiation such as ionizing radiation, it is not necessary to add a photopolymerization initiator or a photosensitizer because it is quickly cured without containing it. Examples of photopolymerization initiators and photosensitizers that are optionally added to the coating composition in the present invention include benzoin, benzoin isobutyl ether, benzyl,
Benzophenone, p-chlorobenzophenone, p
-Carbonyl compounds such as methoxybenzophenone, sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide, azobisisobutyronitrile, azobis-
Examples of photosensitizers include azo compounds such as 2,4-dimethylvaleronitrile, peroxide compounds such as benzoyl peroxide and ditertiary butyl peroxide, and examples of photosensitizers include amine compounds such as aliphatic amines and aromatic amines. , ureas such as o-tolylthiourea, sulfur compounds such as sodium diethyldithiophosphate, s-benzylisothiuronium-p-toluenesulfonate, and nitriles such as N,N-disubstituted p-aminobenzonitrile compounds. , phosphorus compounds such as tri-n-butylphosphine, and other nitrogen compounds such as N-nitrosohydroxylamine derivatives. Among these, preferred photoinitiators for radical polymerization include benzophenone, benzoin isobutyl ether, 4'-isopropyl-2-hydroxy-2-methyl-propiophenone, 2-hydroxy-2-methyl-propiophenone, α, α-dichloro-4-phenoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, benzyldimethylketanol, 2,2-diethoxyacetophenone, chlorothioxanthone, 2-isopropylthioxanthone, Kayakyuar DITX (Nippon Kayaku Co., Ltd.) thioxanthone compound manufactured by the company), Kayaki Your MBP (benzophenone compound manufactured by the company),
Examples include Juvecryl P36 (radically polymerizable high molecular weight benzophenone manufactured by USB, Belgium), and preferred photosensitizers for radical polymerization include ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4,4 '-Bisdiethylaminobenzophenone, Juvecryl P104 (radical polymer polymerized tertiary amine compound manufactured by UCB, Belgium), N-methyldiethanolamine,
Examples include diethylaminoethyl methacrylate and triethylamine. These photopolymerization initiators and photosensitizers are
For 100 parts by weight of the total amount of components (A), (B) and (C)
It is usually used in the range of 0.01 to 10 parts by weight,
Preferably it is in the range of 1 to 8 parts by weight. The amount added
If it exceeds 10 parts by weight, storage stability deteriorates, which is not preferable. In addition, when curing using heat and ultraviolet rays together,
It is possible to use the above radical polymerization initiator together with a photopolymerization initiator and/or a photosensitizer. The total amount added is preferably 0.01 to 10 parts by weight based on 100 parts by weight of the total amount of components (A), (B), and (C). The coating composition of the present invention may further contain various additives as necessary, and may be diluted with a solvent if desired. The above additives include thermal polymerization inhibitors, curing accelerators, organic silane compounds, leveling agents, antifoaming agents, slip agents, pinhole/crater inhibitors, coating surface improvers such as wetting improvers, plasticizers, Colorants, etc. As the thermal polymerization inhibitor, hydroquinone, hydroquinone monomethyl ether, hydroquinone monobenzyl ether, hydroquinone monopentyl ether, 2,6-di-tert-butyl-4-methylphenol, 4,4'-thiobis(6-tert-
butyl-3-methylphenol), 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-butylidenebis(6-tert-butyl-4-methylphenol), para-tert- Butylcatechol and the like are used in an amount of usually 0.001 to 5 parts by weight, preferably 0.005 to 4 parts by weight, based on 100 parts by weight of the total amount of (A), (B) and (C). Examples of the curing accelerator include cobalt naphthenate, zinc naphthenate, dimethylaniline, dibutyltin laurate, etc., and the amount is usually 0.001 to 100 parts by weight per 100 parts by weight of the total amount of components (A), (B), and (C). It is used in an amount of 5 parts by weight, preferably in a range of 0.005 to 4 parts by weight. Examples of organic silane compounds include aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane,
A silane coupling agent having an amino group such as hexamethyldisilazane, a silane coupling agent having an epoxy group such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3
- There are silane coupling agents having a mercapto group such as mercaptopropyltrimethoxysilane, and the total amount of components (A), (B), (C) and (D) is 100
Usually 0.01 to 10 parts by weight, preferably
It is used in a range of 0.05 to 5 parts by weight. The coating surface improver is usually used in an amount of 0.001 to 5 parts by weight, preferably 0.005 to 4 parts by weight, based on 100 parts by weight of the total amount of components (A), (B), (C), and (D). . Examples of plasticizers include phthalic acid esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, and dioctyl phthalate, dimethyl glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, and butyl phthalyl ethyl glycolate. , glycol esters such as triethylene glycol dicaprylate,
Examples include phosphoric acid esters such as tricresyl phosphate and triphenyl phosphate, triethyl citrate, glycerin triacetyl ester, and butyl laurate. The amount of these plasticizers added is usually 20 parts by weight or less, preferably 15 parts by weight or less, based on 100 parts by weight of the total amount of components (A), (B), (C) and (D). Examples of colorants include carbon black,
There are pigments such as iron oxide, phthalocyanine pigments, and azo pigments, and dyes such as methylene blue, keristal violet, rhodamine B, axin, auramine, azo dyes, and anthraquinone dyes, but the absorption wavelength of the photopolymerization initiator A material that does not absorb light is preferable. The amount of coloring agent added is as described in (A) above.
The pigment is usually 0.01 to 30 parts by weight, preferably 0.1 to 3 parts by weight per 100 parts by weight of the total amount of components (B), (C) and (D).
For dyes, it is usually 0.01 to 10 parts by weight.
Parts by weight, preferably in the range of 0.1 to 3 parts by weight. Examples of solvents used here include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and diisobutyl ketone, ethyl acetate, butyl acetate, amyl acetate, methyl formate, ethyl propionate, dimethyl phthalate, and ethyl benzoate. esters such as, aromatic hydrocarbons such as toluene, xylene, benzene, ethylbenzene, halogenated carbon tetrachloride, trichloroethylene, chloroform, 1,1,1-trichloroethane, monochlorobenzene, methylene chloride, chlornaphthalene, etc. Hydrocarbons, tetrahydrofuran, diethyl ether,
Examples include ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether acetate, dimethyl formamide, and dimethyl sulfoxide. Examples of ultraviolet light sources for curing the coating composition include xenon lamps, low-pressure mercury lamps, high-pressure mercury lamps, and ultra-high-pressure mercury lamps, and examples of electron beam sources include 20-2000 KV electron beam accelerators.
As the atmosphere for irradiation with active energy rays such as ultraviolet rays and electron beams, an atmosphere of an inert gas such as nitrogen gas or carbon dioxide gas or an atmosphere with a reduced oxygen concentration is of course preferable, but a normal air atmosphere may be used. The irradiation atmosphere temperature may be room temperature or may be actively heated to utilize heat for the curing reaction.
The temperature ranges from 10 to 200°C. (Effects of the present invention) The optical communication glass fiber coating composition of the present invention has fast curing properties, flexibility, and
It has effects that have not been previously available, such as excellent long-term reliability, small changes in physical properties due to temperature changes, and excellent workability (Example) The present invention will be explained in more detail by Examples, Comparative Examples, and Reference Examples. Explain. All parts in the examples are based on weight. Reference Example 1 In a flask equipped with a stirrer, a thermometer, and a reflux condenser, 1058 gr of polyether polyol (hydroxyl value 106, molecular weight 1058) prepared by copolymerizing tetrahydrofuran and ethylene oxide at a weight ratio of 50/50,
After charging 0.3gr of triethylamine and 410gr of 2-ethylhexyl acrylate and heating to 50℃,
348 gr of tolylene isocyanate was gradually charged so as to keep the temperature within the range of 50 to 60 °C, then 232 gr of 2-hydroxyethyl acrylate was added, and the reaction was continued until the isocyanate group content was 0.1%.
A composition consisting of 80% by weight of the desired polyether polyol-based urethane acrylate prepolymer and 20% by weight of 2-ethylhexyl acrylate [viscosity
3200 cps (23°C), crystallization temperature <-20°C] was obtained.
The composition obtained here is referred to as [A-1]. The viscosity was determined based on JIS K-6901 using a BM type viscometer (Tokyo Keiki Seisakusho) using rotor No. 3 and rotation speed.
Measured at 12 rpm. Reference Example 2 In a flask equipped with a stirrer, thermometer and reflux condenser, 1675gr of polyether polyol (hydroxyl value 67, molecular weight 1675) prepared by copolymerizing tetrahydrofuran and ethylene oxide at a weight ratio of 70/30, and 0.4gr triethylamine. , 564gr of 2-ethylhexyl acrylate was prepared in the same manner as in Reference Example 1 to prepare a composition consisting of 80% by weight of polyether polyol-based urethane acrylate prepolymer and 20% by weight of 2-ethylhexyl acrylate [viscosity
3900 cps (23°C), crystallization temperature <-20°C] was obtained.
The composition obtained here is referred to as [A-2]. Reference Example 3 In a flask equipped with a stirrer, thermometer, and reflux condenser, 2877gr of polyether polyol (hydroxyl value 39, molecular weight 2877) prepared by copolymerizing tetrahydrofuran and ethylene oxide at a weight ratio of 30/70, and 0.5gr triethylamine. , 864 gr of 2-ethylhexyl acrylate was prepared, and in the same manner as in Reference Example 1, a composition consisting of 80% by weight of polyether polyol-based urethane acrylate prepolymer and 20% by weight of 2-ethylhexyl acrylate [viscosity
4400 cps (23°C), crystallization temperature <-20°C] was obtained.
The composition obtained here is referred to as [A-3]. Reference Example 4 In a flask equipped with a stirrer, thermometer and reflux condenser, 2078gr of polyethylene glycol (hydroxyl value 54, molecular weight approx. 2000), 0.5gr triethylamine,
Prepare 665gr of 2-ethylhexyl acrylate,
The following is a composition made of 80% by weight of polyether urethane acrylate prepolymer and 20% by weight of 2-ethylhexyl acrylate [viscosity 11000 cps (23°C), crystallization temperature 10-15°C] in the same manner as in Reference Example 1.
I got it. The composition obtained here is referred to as [A'-1]. Reference Example 5 Polytetramethylene glycol (hydroxyl value
58, molecular weight approx. 2000) 1934gr, triethylamine
0.4gr and 629gr of 2-ethylhexyl acrylate, and in the same manner as in Reference Example 1, a composition consisting of 80% by weight of polyether urethane acrylate prepolymer and 20% by weight of 2-ethylhexyl acrylate [viscosity 12500cps (23°C), Crystallization temperature 15
~20°C] was obtained. The composition obtained here is referred to as [A'-2]. Examples 1 to 4 and Comparative Examples 1 to 2 As shown in Table 1, urethane acrylate prepolymers [A-1] and [A
-2], [A-3], [A'-1] and [A'-2], 2-ethylhexyl acrylate and benzoin butyl ether were added, and the viscosity at 23℃ was
The viscosity was adjusted to around 3200 cps to obtain optical communication glass fiber coating compositions for the present invention and for comparison. Next, the following tests were conducted to examine the performance of these coating compositions. <Coating film performance evaluation test> Each coating composition was applied onto a quartz glass plate so that the film thickness after curing was 0.2 mm, and then irradiated with ultraviolet rays for a predetermined period of time using an 80 W/cm high-pressure mercury lamp to cure. Then peel off the hardened film and apply JIS K
A tensile test was conducted based on -7113, and the tensile strength, elongation at break, and Young's modulus were measured. The glass transition point (Tg) was determined from the maximum value of tan δ measured using a viscoelastic spectrometer TypeVES-HS (manufactured by Iwamoto Seisakusho) at a frequency of 35 Hz and a heating rate of 3° C./min. For heat-resistant products, we conducted a tensile test on the film after leaving it in the air at 80℃ for 30 days, and the change in Young's modulus and elongation at break were both less than 5%, and the change in either one was 50. % or more was rated as ×, and other items were rated as △. For hydrolysis resistance, a tensile test was conducted on the film after being left in water at 80℃ for 30 days, and a film with a change in both Young's modulus and elongation at break of less than 5% was evaluated as ○, and a change in either one was evaluated as 50. Those exceeding % were marked ×, and those other than that were marked △. The irradiation time until the gel fraction saturation was determined using a Soxhlet extractor, methyl ethyl ketone as the solvent, and ultraviolet irradiation (80W/
cm (high-pressure mercury lamp), and the irradiation time until the gel rate was saturated was measured. <Coating test> Examples 1 to 4 and Comparative Examples 1 to 4 were coated on the surface of a glass fiber with a diameter of 125 μm spun at a speed of 100 m/min.
After applying the coating composition No. 2 so that the outer diameter after curing is 200 μm, UV light (lamp output
A coated optical communication glass fiber was obtained by irradiating with 2KW, 2 lamps) and curing to obtain a coated optical communication glass fiber.The smoothness of the coated surface was evaluated by touch and visual inspection, and the stickiness was evaluated by touch, and the breaking strength was determined by 80%. Changes in transmission loss after being left in air at 80°C for 30 days and in water at 80°C, and increases in transmission loss at -40°C were measured.
In addition, the change in transmission loss is less than ±0.2dB/Km as ○,
±0.2dB/Km or more ×, the increase in transmission loss is
Less than 0.1 dB/Km was marked as ○, and 0.1 dB/Km or more was marked as ×. The results are shown in Table 2.

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Claims (1)

[Scope of Claims] 1. A polyether polyol compound (a) obtained by ring-opening copolymerization of two or more types of ionically polymerizable cyclic compounds, a polyisocyanate compound (b), and a hydroxyl group-containing (meth)acrylate compound ( 1. A composition for coating optical communication glass fibers, characterized in that it contains as an essential component a polyether polyol-based urethane (meth)acrylate prepolymer (A) obtained by reacting with c). 2. The composition for coating optical communication glass fibers according to claim 1, wherein the polyether polyol compound (a) contains 5 to 95% by weight of tetrahydrofuran.