JPS62216946A - Coating composition for optical fiber - Google Patents

Abstract

PURPOSE:To obtain the titled composition having appropriate viscosity and excellent coated film physical property and water resistance as the primary coating composition for optical fiber by forming the composition with specified urethane acrylate and mono(meth)acrylate. CONSTITUTION:The activation energy beam curing composition for optical fiber consists of 30-90wt% reaction product obtained by the reaction of a polyol with a polyisocyanate and a lactone-(meth)acrylate addition material and 70-10wt% mono(meth)acrylate shown by the formula [X is alkyl and (alkyl-substituted) phenyl, R is H and methyl, and (n) is 2-6]. The composition has appropriate viscosity and excellent coated film physical property (low modulus and high fracture elongation) and water resistance as the primary coating composition for optical fiber.

Description

[Detailed description of the invention] ? '5 (1'-Gin and -1- Resin that cures by irradiation with active energy rays can be cured in seconds. Low pollution because it uses electrical energy and almost no solvent evaporates. is measured.

Since high temperatures are not required for curing, there is no thermal deformation of the coated object.
The curing device can be downsized and space can be saved. Due to the short wavelength of energy rays, it has good image reproducibility, and is used in the printing industry, for example, as ultraviolet curing paint, electron beam curing paint, photoresist, electron beam resist, X-ray resist, plate-making material, etc. , has wide applications in fields such as electronic industry.

Old energy ray-curable resin compositions are also attracting attention as optical fiber coating compositions. For protection, Zunawara optical fibers are coated with a protective layer immediately after being drawn. This protection tax not only prevents scratches on the glass in subsequent processes, but also prevents fiber deterioration and microbending that causes signal attenuation even after the product is manufactured. is necessary. As the drawing speed of optical fibers increases, there is a need to shorten the curing time of coating compositions, and active energy ray-curable resin compositions such as ultraviolet ray curing and electron beam curing, which cure in seconds, are being used for coating optical fibers. It is ranked 11th as a composition.

Optical fiber coating compositions, particularly secondary coating compositions, are required to have a low modulus in the service temperature range (-40°C to 80°C) and a high elongation at break. In addition, water resistance such as low water absorption (and little change in physical properties of the coating after hot water immersion test) is required. Also, in order to efficiently coat optical fibers with a uniform tlQ thickness, a suitable viscosity (approximately 3000 7 inches to about 7,000 inches).

Is it silicone initially? An I'FW agent was used, but because it is thermosetting, it is difficult to keep up with the increase in drawing speed, and today, UV-curable urethane acrylate-based coating agents have been developed. (Unexamined Japanese Patent Publication No. 58-2236
(No. 38, JP-A No. 60-181170) However, urethane acrylate resins generally have a high viscosity, and it is often difficult to coat them as they are. JP-A No. 58-223638 describes the use of monoethylenically unsaturated heptamers that can form strong hydrogen bonds, but these heptamers are water soluble or have strong hydrophilicity, so they are not water resistant. Gender is remembered.

Furthermore, JP-A-60-181170 states that phosphoric acid esters and fatty acid esters can be used as viscosity reducing agents, but since these do not have photopolymerizability, depending on the amount used, the curing furnace may become sticky. There are problems such as exhibiting sexual characteristics.

Due to its low modulus performance, silicone rubber has traditionally been used as an insulating material for electrical equipment, as a vibration and shock absorbing material, and as a sealing material, banking material, coating material, etc.
Widely used as a lining material. Silicone rubber has excellent electrical properties, heat resistance, cold resistance, and weather resistance.
It has drawbacks such as being expensive, requiring a long time or high temperature for curing, and being a two-part type.

The present invention has a viscosity and good coating film properties (low modulus) suitable for use as a primary coating composition for optical fibers.

An object of the present invention is to provide a composition having high elongation at break) and good water resistance.

Saba Inu Left Determination The present invention provides (a) 30 to 90% by weight of a reaction product obtained by reacting a polyol with a polyisocyanate and a lactone=(meth)acrylate adduct; (b) a compound represented by the following (meth)acrylate 70-10% by weight (wherein, X is an alkyl group, phenyl group or alkyl-substituted phenyl group, R is a hydrogen atom or a methyl group, n is 2-
Represents 6 integers. ) provides a coating composition for optical fibers characterized by comprising:

By using urethane acrylate, which is made by reacting a polyol with a polyisocyanate and a lactone/(meth)acrylate adduct, as a resin component, the physical properties of the coating film (low initial Young's modulus, high elongation at break).

The coating composition must have an appropriate viscosity (approximately 3000 to 1000 Qcps) for commercially coating optical fibers. Urethane acrylate resin is either a high viscosity liquid or a solid, so in order to achieve an appropriate viscosity, a low viscosity monomer that can be copolymerized with 1 each of urethane acrylate resins is used. When a monomer is used, the initial Young's modulus increases, the elongation at break decreases, and the water absorption rate increases, which diminishes the excellent coating performance of the urethane acrylate resin.

The monomer for the construction of this point (A) is the above reaction product (a)
Maintains good coating film performance even when combined with

The polyol herein refers to a synthetic organic polymer compound having two or more hydroxyl groups in the molecule. Examples include polyether polyols, polyester polyols, polyurethane polyols, polybutadiene polyols, silicone polyols, and the like.

An example is shown below.

I) polyether polyol compounds, such as polyalkylene glycols (e.g. polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhequinamethylene glycol) or alkylene oxides (e.g. ethylene oxide, propylene oxide, tetrahydrofuran); Polyhydric alcohols (e.g. ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerol, trimethylolpropane, 1,3-butanediol, 4-butanediol, 1,5-hexanediol, L2,6-hexandri ii) polyester polyol compounds, such as polybasic acids (e.g. fucuric acid, isophthalic acid, terephthalic acid, tetrahydrofucric acid, tetra Chlorphthalic acid, tetrabromophthalic acid, hexahydrophthalic acid, hemic acid, het acid, succinic acid, maleic acid, fumaric acid, adipic acid, sebacic acid, dodecenyl succinic acid, trimellitic acid, bilomellitic acid) or their Anhydrides and polyhydric alcohols (e.g. ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerol, trimethylolpropane, I+3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, II2 .6-hexandriol, penquerythritol, sorbitol, bisphenol A), polyester polyols obtained by condensation reactions with the above polyhydric alcohols and epoxy compounds (e.g. Cardura E, n-butyl glycidyl ether, allyl glycidyl ether) and the above polyols. Polyester polyols obtained by the reaction of basic acids, polyester polyols obtained by the reaction of the above epoxy compounds and the above polybasic acids, higher fatty acids (e.g. soybean oil, linseed il+, safflower oil, palm oil, dehydrated castor oil, Kiriura) , rosin), the above-mentioned polybasic acid, and the above-mentioned polyhydric alcohol.
Polymerizable polyester polyols obtained by ring-opening polymerization of caprolactone and the above polyalcohol; iii) Polyurethane polyol compounds, such as 71
(Liisocyanate compounds (e.g. ethylene diisocyanate, propylene diisocyanate, te]ramethylene diisocyanate, hexamethylene diisocyanate, l-methyl-2,4-diisocyanate cyclohexane, 1-methyl-2,6-diisocyanate cyclohexane, ω, ω'- diisocyanate diethylbenzene,
ω, ω′-diisocyanate dimethylaminotoluene,
ω, ω゛-Diisocyanate dimethylxylene, ω, ω
”-diisocyanate diethylxylene, lysine diisocyanate, 4,4゛-methylenebis(cyclohexylisocyanate'), 4,4°-ethylenebis(cyclohexylisocyanate), ω, ω°-diisocyanate 1-1,3-dimethylbenzene, ω , ω゛-diisocyanate L/l-dimethylbenzene, isophorone diisocyanate, 2,4-tolylene diisocyanate I.
, 2.6-) lylene diisocyanate-1-1; polyhydric alcohol (e.g. ethylene glycol, propylene glycol, 1.3-butyl glycol, neopentyl glycol, 2゜2.4-trimethyl-1,3-
polyurethane polyols obtained by addition reaction with (bentanediol, hexamethylene glycol, cyclobexane dimetatool, trimethylolpropane, hexanetriol, glycerin, sorbitol, sorbitan, sucrose, pentaerythritol, etc.); Ether polyols, polyester polyols, and polyurethane polyols obtained by addition reaction of relatively low molecular weight polyol compounds among polymerizable polyester polyols and the above-mentioned polyisocyanes 1 to 1 compounds; iv) polybutadiene compounds, e.g. hydrogen Added or unadded 1,4-polybutadiene diol, etc.; V) silicon-based compounds such as dimethyl(poly)siloxane, methylphenyl(poly)siloxane, methylvinyl(poly)siloxane, cyanoalkylmethyl(poly)siloxane, Fluorinated alkyl medyl(poly)siloxanes and pro-, co-, or graft copolymers made of arbitrary or arbitrary combinations thereof, in which two or more hydroxyl groups are present at the end of the molecule or within the molecule, etc. ;

As starting materials for the polyisocyanate polyurethane polyol compounds, the polyisocyanate-1 compounds mentioned above can be used.

The lactone-(meth)acrylate adduct used in the present invention is
Lactone and hydroxy(meth)alkyl acrylate-1-
It is produced by reacting with.

Here, the lactone is represented by the general formula: (wherein R1 and R2 represent hydrogen and a hydrocarbon residue, respectively, and n represents an integer from 4 to 7).

A preferred lactone for use in the present invention is ε-caprolactone. The hydroxyalkyl (meth)acrylates used to produce the lactone-(meth)acrylate adduct include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl acrylate, 2-hydroxy-3-chloro-propyl (meth)acrylate and the like can be used.

The reaction product of polyol, polyisocyanate and lactone-(meth)acrylate adduct of the present invention can be produced by any of the methods described below.

1) Polyol, polyisocyanate, and lactone-(meth)acrylate adduct are charged all at once and reacted.

2) The polyisocyanate-1. and lactone-(meth)acrylate adduct are first reacted and then reacted with the polyol.

3) A polyol is reacted with a polyisocyanate, and then a lactone-(meth)acrylate adduct is reacted with the polyol.

For example, bifunctional polyol, bifunctional isocyanate,
When using a monofunctional lactone-(meth)acryle-1-adduct, method 3) is preferably employed in order to obtain a reaction product having a desired molecular weight.

In addition, when using a trifunctional or higher functional polyol and/or a trifunctional or higher functional isocyanate, in order to prevent gelation during the reaction, polyisocyanate 1- and monofunctional lactone-
The (meth)acryle-I adduct is reacted to reduce the NCO groups of the polyisocyanate 1- (preferably reacted to have one NGO group in the molecule) and then the polyol is reacted, i.e. 2 ) method is recommended.

Molar ratio of polyol to polyisocyanate-1, lactone-(meth)acrylate used Gsi1; (? IJ
1.2 to 5 mol of polyisocyanate, 0.3 to 5 mol of lactone-(meth)acrylate adduct per equivalent of ol
molar ratio of the total number of OH groups of the polyol and lactone-(meth)acrylate adduct to the number of NGO groups in the polyisocyanate 1)! /NCO ratio should be greater than 1 so that no free isocyanate groups remain in the reaction product.

In the synthesis of the above reaction products, if necessary, conventional polymerization inhibitors (eg, hydroquinone) are used.

1 of the total weight (hydroquinone methyl ether, etc.)
00-5000ppm, preferably 500-200Qp
pm, and a urethanization catalyst (for example, triethylamine, stannous octoate, dibutyltin dilaurate, etc.) in an amount of 100 to 500 Qppm, preferably 5
00 to 2000 ppm is used, and the reaction is carried out at a temperature of 30 to 150°C, preferably 30 to 100°C.

NGO groups can be detected, for example, by the usual amine chain method or by infrared absorption spectroscopy using 2200 an-
'(= This can be done depending on the presence or absence of absorption near f.

The reaction can be carried out in the presence of l6 medium. Examples of the solvent include ethyl acetate, n-butyl acetate, henzene, 1-helene, xylene, and methyl ethyl ketone.

Organic solvents commonly used in urethanization reactions can be used, such as methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, and ethoxyethyl acetate-1. These organic solvents may be used alone or in combination.

After the reaction is completed, the monomer of formula (A) is added, and the organic solvent is removed by heating if necessary under reduced pressure.

Mono(meth)acrylate 8) The mono(meth)acrylate used in the present invention has the formula (wherein, X is an alkyl group, a phenyl group, or an alkyl-substituted phenyl group, R is a hydrogen atom or a methyl group, is 2~
Represents 6 integers. ), which are (meth)acrylates of propylene oxide adducts of aliphatic alcohols, and (meth)acrylates of propylene oxide adducts of phenol and alkylphenols.

The average number of moles of propylene oxide added is preferably 2 to 6 based on the viscosity.

Specific examples of aliphatic alcohols include methyl alcohol, ethyl alcohol, n-7'' lobil alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, 5ec-butyl alcohol, LarL-butyl alcohol, and alkyl-substituted alcohols. Specific examples of phenol include cresol, nonylphenol, p-cumylphenol, benzylphenol, and the like.

In the present invention, mono(meth)acrylates may be used alone or in combination of two or more.

Active energy rays include ultraviolet, electronic, X-ray, and radiation.

The active energy ray-curable coating composition for optical fibers of the present invention comprises (a) polyol/polyisocyanate/lactone-(
meth)acrylate oligomer and (b) mono of formula A
(meth)acrylate as an essential component, and may optionally contain (1) a sensitizer (essential in the case of ultraviolet curing), (2) a polymerizable hexamer, and (3) other additives.

+1) Sensitizers include benzophenone, Michler's ketone, xanthone, thioxanthone, 2-chlorothioxanthone, Hensyl, 2-ethyl anthraquinone, 2-
Hydroxy-2-methylpropiophenone, 2-hydroxy-4゛-isopropyl-2-methyl-propiophenone, methylhendiyl formate, benzoin methyl ether, henzoin edyl ether, henzoin isopropyl ether, henzoin-〇 -butyl ether, hendiine isobutyl ether, acetophenone, trichloroacetophenone, cetophenone, 2,2-dumel-xy-2-phenylaceto-phenone, etc. can be used.

As the polymerizable additive (2), polymerizable monomers that are commonly used for the purpose of diluting viscosity may be used; Its use should be limited to a range in which the elongation at break, water resistance, etc. does not exceed 11'J.

These polymerizable materials include methyl (meth)acrylate, ethyl (meth)acrylate, and n-butyl (meth)acrylate.

2-Ethylhexyl (meth)acrylate, lauryl (
Alkyl (meth)acrylates such as meth)acrylate and nonyl (meth)acrylate (2-hydroxyethyl (meth)acrylate).

Hydroxyalkyl (meth)acrylates such as 2-hydroxypropyl (meth)acrylate, alkoxyalkyl (meth)acrylates such as 2-ethoxyethyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, etc. ) acrylate.

Aryloxyalkyl acrylates such as 2-nonylphenoxyethyl (meth)acrylate Cycloalkyl acrylates such as cyclohexyl acrylate, cyclopentyl acrylate, and isobornyl acrylate Cycloalkenyl (meth)acrylates such as dicyclopentenyloxyethyl (meth)acrylate aminoalkyl acrylates such as diethylamine ethyl (meth)acrylate styrene, vinyl 1-luene. Examples include polymerizable polymers such as vinyl compounds such as vinyl acetate and N-vinylpyrrolidone.

Other additives (3) include fillers (for example, inorganic fine powders such as colloidal silica and extender pigments), colorants, surface conditioners such as silicone and fluorine compounds, and decarbonizing agents.

(a) A reaction product obtained by reacting a polyol with a polyisocyanate and a lactone-(meth)acrylate adduct, and a mono (meth) represented by formula (A).
The blending ratio of acrylate is (a) reaction product 30-9
It is necessary that the content of the mono(meth)acrylate is 70 to 10% by weight.

If the reaction product (a) exceeds this ratio, the viscosity will be high, making it difficult to coat optical fibers.

If the amount of mono(meth)acrylate exceeds this ratio, curing properties will decrease.

The present invention will be explained in detail below using Reference Examples, Examples, and Comparative Examples. In these, "part" and "%" are based on mold mouth standards.

Reference Example 1 In a 1β reaction vessel equipped with a stirrer, a cooler and a temperature control device, 400 parts of butyl acetate and an average molecular weight of
0 4 7 polyoxytetramethylene glycol (Sanyo Kasei +41!!!, trade name P1'MG 20
0, O) r+ surface 5 4.8) 3 1 6.5 parts and xylylene diisocyanate 4 3. After adding 6 parts of dibutyltin dilaurate and stirring thoroughly, add 0.0 parts of dibutyltin dilaurate. 4
．． 0 part was added and the temperature was raised to 80°C and maintained for 1 hour.

Then l (2-hydroxyethyl acrylate modified with ε-caprolactone of IMI (manufactured by Daicel Chemical Industries (4@. trade name Plaxel FA-1)) 3 9
．． Add 1 part and 0.40 part of hydroquinone, and heat to 80°C.
Stirring was continued for 2 hours, and it was confirmed by an infrared absorption spectrum that the absorption of NCO groups had disappeared, to obtain a polyether urethane acrylate-1 resin solution (fat solid content: 50%).

Reference Example 2 In a 1 g reaction vessel equipped with a stirrer, a cooler, and a temperature control device, 400 parts of ethyl acetate and a tetrahydrofuran-propylene oxide copolymer resin (with an average molecular fi of 1996) were added.
Hodogaya Chemical (manufactured by Iil. Product name Pr'TG2000,
0+1 (dish 5G.2) 31/1.8 parts and 1-44.5 parts of xylylene diisocyanate were prepared, and after thorough stirring, 0.40 parts of dibutyltin dilaureh was added to 8Q.
The temperature was raised to 'C and maintained for 1 hour.

2- then modified with one ε-caprolactone
Added 39.9 parts of hydroxyethyl acrylate (manufactured by Daicel Chemical Industries, Ltd., trade name: Plaxel r'A-1) and 0.40 parts of hydroquinone, continued stirring at 80°C for 2 hours, and determined NC○ by infrared absorption spectrum. It was confirmed that the absorption of the group had disappeared, and a polyether urethane acrylate resin solution (resin solid content: 50%) was obtained.

Reference Example 3 Into 11 reaction vessels equipped with a stirrer, a cooler, and a temperature control device, 400 parts of ethyl acetate and 1,4-polybutadiene (manufactured by Idemitsu Petrochemical Co., Ltd., a product Name POLY BDR-45117
, OH value 43.76) and 34.9 parts of xylylene diisocyanate were charged and stirred sufficiently, then 0.40 part of dibutyltin dilaurate was added, and the temperature was raised to 80°C and maintained for 1 hour.

2- which was then modified with two ε-caprolactones
Hydroxyethyl acrylate (Daicel Chemical Industries (
Add 46.8 parts of Toko (product name: Praxeno Kano A-1) and 0.40 parts of hydroquinone, continue stirring at 80°C for 2 hours, and the absorption of NCO groups disappears with infrared absorbing Subek1-1. This was confirmed, and a polybutadiene urethane acrylate resin solution (resin solid content: 50%) was obtained.

Reference Example 4 Into 11 reaction vessels equipped with a stirrer, a cooler, and a temperature control device, 400 parts of ethyl acetate, dimethylpolysiloxane polyol (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22-6OA, ○HIi [li 68)
301.5 parts of xylylene diisocyanate and 51.5 parts of xylylene diisocyanate were charged, and after sufficient ITV, 0.40 part of dibutyltin dilaurate was added, and the temperature was raised to 80°C and maintained for 1 hour.

Next, 2-hydroxyethyl acrylate modified with ε-caprolactone of lN111 (manufactured by Daicel Chemical Industries, Ltd. (41), trade name Plaxel I'A-1)
Add 46.2 parts and 0.40 parts of hydroquinone, and heat to 80°C.
Stirring was continued for 2 hours, and it was confirmed by infrared absorption spectrum that the absorption of NC◯ group had disappeared, and a polysilicone urethane acrylate resin solution (resin solid content: 50%) was obtained.

Example l CH30 1lI CH3O→CH2-Cl! -0±C-Cl1=CH2
After blending 40 parts and 2 parts of henzyldimethylkecour, ethyl acetate was distilled off under reduced pressure to obtain a coating composition.

Paint the composition on a glass plate to a thickness of 100μ,
A cured film was obtained by performing ultraviolet treatment under the conditions shown below. Next, the cured film was peeled off from the glass plate to prepare a tensile test sample, and a tensile test using Tensilon was conducted.

It has good elongation at break and initial Young's modulus. The results are shown in Table 1.

Ultraviolet image ■■ Striped Japanese battery high pressure mercury lamp l1l-4ON (80W/
cm type.

Place the length of the lamp (using a condensing device) perpendicular to the conveyor traveling direction, and set the conveyor speed to 3 m/min at a height of 80 mm from the conveyor surface.

'jL!' by Tensilon! IU"2 ・Tensilon tensile tester (manufactured by Toyo Baldwin Co., Ltd., l1l-1
When measuring the elongation at break, the initial Young's modulus was 1JllI at a tensile rate of 50mm/min at -40"C and 20°C for a sample with a film length of 50 parts m and a medium diameter of 10mm. In this case, the tensile speed was 1 mm/min.

The initial Young's modulus was measured by measuring the modulus at 2.5% elongation.

The viscosity was measured at 25°C using a cat skin breath constant EM viscometer (Kikki Tokyo δ1) and the results are shown in Table 1.

A film prepared for a physical property test was immersed in a thermostatic water tank adjusted to 80° C. for one month.

Thereafter, the film was taken out and placed indoors for 2 days to dry, and then a physical property test was conducted. The results are shown in Table 1.

Waterwheel Hoshisada Water absorption was measured by JIS K 7209 B method.

After blending 2 parts of Henzil dimethylkekool, ethyl acetate was distilled off under reduced pressure, and the coating composition (!
Also. Various tests were conducted in exactly the same manner as in Example 1 using this composition. The results are shown in Table 1.

Example 3 After blending 2 parts of benzyl dimethyl kecour, ethyl acetate was distilled off under reduced pressure, and the coating composition was reduced to 73%
>Ta. Various tests were conducted in exactly the same manner as in Example 1 using this composition. The results are shown in Table 1.

Example 4 After blending 40 parts of the monomer used in Example 1 and 2 parts of henzyl dimethyl kecour, ethyl acetate was distilled off under reduced pressure to obtain a coating composition. Using this composition, various tests were carried out in the same manner as in Example 1. The results are shown in Table 1.

Example 5 After blending the polybutadiene urethane acrylate of Reference Example 3 (100 parts of sealing solution) with 50 parts of the monomer used in Example 1 and 2 parts of henzyl dimethyl kecour, the ethyl acetate was distilled off under reduced pressure to obtain the coating composition. Using this composition, various tests were carried out in exactly the same manner as in Example 1.

The results are shown in Table 1.

Example 6 After blending 30 parts of the monomers used in Example 1 and 2 parts of henzyldimethylkecour, the reduced ethyl acetate was distilled off to obtain a coating composition. Various tests were conducted in exactly the same manner as in Example 1 using this composition. The results are shown in Table 1.

Ratio Example 1 An ultraviolet curable composition was obtained in exactly the same manner as in Example 1, except that 40 parts of N-vinylpyrrolidone was used in place of the 7-mer. Various tests were conducted on this composition in exactly the same manner as in Example 1. The results are shown in Table 1.

Example 7 Silica glass fibers were spun to have a diameter of 125μ, and immediately after spinning, each of the compositions of Examples 1 to 4 was coated to a film thickness of 1OOμ, and irradiated with ultraviolet rays to obtain a primary coated glass fiber. I was able to do that.

This second coated glass fiber did not crack or peel off even when bent (it had sufficient flexibility).

Furthermore, no increase in transmission rO loss was observed for each of the primary coated glass fibers up to -60°C.

(Margin below)

Claims (3)

[Claims] (1) (a) 30 to 90% by weight of a reaction product obtained by reacting a polyol with a polyisocyanate and a lactone-(meth)acrylate adduct (b) Mono(meth)acrylate 70 represented by the following formula
~10% by weight ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula,
represents an integer. ) An active energy ray-curable coating composition for optical fibers. (2) The optical fiber coating composition according to item 1, wherein the polyol is selected from polyether polyols, polyester polyols, polyurethane polyols, polybutadiene polyols, and silicone polyols. (3) Polyether polyol is polyethylene glycol, polypropylene glycol, ethylene oxide/
2. The optical fiber coating composition of item 2, which is selected from the group consisting of propylene oxide copolymers, polytetramethylene glycol, tetramethylene oxide/ethylene oxide copolymers, tetramethylene oxide/propylene oxide copolymers, or mixtures thereof.