JPH028272A - Coating composition for optical fiber - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in various physical properties after dipping in hot water for a long period by using a polyurethane poly(meth)acrylate prepared employing a bisphenol-type specific polyol as a polyol component. CONSTITUTION:The objective composition obtained by blending (A) a polyurethane methacrylate prepared by reacting a bisphenol alkylene oxide adduct with a diisocyanate compound and hydroxyl group-containing acrylate or methacrylate with (B) a compound having one polymerizable double bond in one molecule and (C) a photopolymerization initiator in an amount of 0.1-10wt.% (based on the weight of the composition) at (20/80)-(95/5) weight ratio of the components (A)/(B).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a composition suitable for coating optical fibers for light transmission.

[Conventional technology]

Optical glass fibers break at microscopic scratches scattered on the surface of the glass. This can be a fatal defect for optical fibers, so some kind of coating is required to prevent this.

Silicone resin has traditionally been used as a coating material for optical fibers, but many UV-curable coating materials have recently been developed as an alternative to silicone resins because they are expected to offer higher productivity and performance than silicone resins. ing.

The performance requirements for coating materials include a short curing time and good strength and elongation of the resulting coating film, and various proposals have been made to meet these requirements. Among them, JP-A-60-181170 and JP-A-61-26536.
, 61-291611, 62-30640, 62
-30641 and 62-30642 propose coating materials that use urethane acrylate and urethane methacrylate (hereinafter, "acrylate" and "methacrylate" are collectively referred to as "(meth)acrylate") as main components. In this proposal, in order to maintain a good balance between elongation and toughness of the cured product, various studies were conducted on the polyol component used in synthesizing polyurethane poly(meth)acrylate.

However, in order to obtain long-lasting reliability as an optical fiber, it is not enough to maintain a balance between toughness and elongation; various physical properties must be satisfied after secondary environmental tests. It won't happen. However, with the curable materials proposed so far, the physical properties after secondary environmental tests, especially after long-term immersion in hot water (for example,
It has been found that there is a problem in that various physical properties deteriorate after being immersed in hot water at 80°C for one month.

[Problem that the invention seeks to solve]

In view of the current state of the art as described above, an object of the present invention is to provide a composition useful as an optical fiber protective coating that has excellent physical properties, especially after being immersed in hot water for a long time.

[Means for solving problems]

The above purpose is to achieve polyurethane polyurethane IJ (%) using a specific bisphenol polyol as a polyol component.
&) M + J v-t- is used as the main material. The present invention has been completed based on the discovery that this can be achieved by the following methods.

That is, the present invention provides (a) a polyurethane polyacrylate or a polyurethane polymethacrylate obtained by reacting a bisphenol-based alkylene oxide adduct as a polyol component with a diisocyanate compound and a hydroxyl group-containing acrylate or a hydroxyl group-containing methacrylate; It comprises a compound having one polymerizable double bond in one molecule, and (c) a photopolymerization initiator, and the weight ratio of (a)/(b) is 20/80 to 9.
5/5, and the amount of (c) is 0.5 based on the weight of the composition.
Provided is an optical fiber coating composition characterized in that the coating composition contains 1 to 10% by weight.

The polyurethane poly(meth)acrylate as component (a) used in the present invention is obtained by reacting a bisphenol alkylene oxide adduct as a polyol component, a diisocyanate compound, and a hydroxyl group-containing (meth)acrylate. The bisphenol alkylene oxide adduct used as the polyol component is represented by the following formula (n) R.

(In the formula, R,, R2 is hydrogen or a methyl group, R,
, R4 is an alkylene group, and n is an integer of 1 to 10. ) Compounds represented by: Specific examples of such compounds include 2,2-bis[4(2-hydroxyethoxy)phenyl]propane, 2.2-bis[4(2-hydroxyethoxyethoxy)phenyl]propane, 2.
2-bis[4(2-hydroxypropoxy)phenyl]
Examples include propane, 2°2-bis[4(2-hydroxypropoxypropoxy)phenyl]propane, and the like.

Examples of the diisocyanate compound to be reacted with the polyol component include tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate,
Isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane-4,
Examples thereof include 4'-diisocyanate, 1,6-hexane diisocyanate, and diphenylmethane-4,4'-diisocyanate.

As the hydroxyl group-containing (meth)acrylate, 2
Examples include compounds such as -hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

Among these, dicyclohexylmethane-4,4'-diisocyanate is most preferred from the viewpoint of the balance between strength and elongation of the cured product.

As a method for synthesizing polyurethane poly(meth)acrylate (a) from the above raw materials, conventionally known synthesis methods can be employed. As for the reaction amount ratio of each component, the polyol component diisocyanate compound ratio is 0.3
/1.0 to 0.9/1.0, and the remaining isocyanate may be reacted with equimolar amount of hydroxyl group-containing (meth)acrylate. If the reactivity ratio is outside this range, the viscosity will become too high, resulting in poor workability, a large amount of bleed-out material after the 80°C hot water resistance test, and physical properties such as strength and elongation will deteriorate, which is undesirable. .

In the composition of the present invention, the polymerizable (b) in one molecule is
Formulated to provide coating suitability.

Specific examples of such compounds (b) include compounds having one or more double bonds, such as tetrahydrofurfuryl (meth);
Acrylate, Hydroxyphenyl C meth)acrylate, Phenoxyethyl(meth)acrylate, Isodecyl(meth)acrylate, Lauryl(meth)acrylate, Benzyl(meth)acrylate, Isobornyl(meth)acrylate, Cyclohexyl(meth)acrylate, Dicyclopentageni (meth)acrylate, 2
- Hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, α-vinylpyrrolidone, a compound of tetrahydrofurfuryl alcohol and ε-caprolactam adduct is a compound containing a (meth)acryloyl group, 2-ethylhexyl ( Examples include meth)acrylate, a compound represented by the following structural formula (Ill), and the like. Among them, the following structural formula (
Most preferred are compounds represented by II).

Cut@Cl-CMOCzH4)TO-CH2Cl(C
IOs)-(CHI)! -Cu5 (III) (wherein n is 1 or 2) In the composition of the present invention, polyurethane poly(meth)acrylate (a) and a compound (b) having a polymerizable double bond in one molecule The ratio is 20/80 to 9515 (weight ratio), and if it is out of this range, there will be more bleed-out items after 80℃ hot water resistance, and the strength and elongation will decrease, making it unsuitable for optical fibers. It becomes unsatisfactory.

Specific examples of photoinitiators used in the composition of the present invention include 2,2-dimethoxy-2phenylacetophenone, acetophenone, benzophenone, xanthone, fluorenone, benzaldehyde, anthraquinone,
3-Methylacetophenone, 4-chlorobenzophenone, 4-4'-diaminobenzophenone, benzoinpropyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1-(4-isopropylphenyl)-
2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, camphorquinone, 2-methyl-
1-(4(methylthio)phenyl]-2-morpholino-
Examples include propan-1-one.

These photopolymerization initiators can be used alone or in combination of two or more in any proportion. The amount used is usually 0.1 to 10% by weight, preferably 1 to 5% by weight, based on the weight of the composition.

The composition of the present invention may optionally contain polymerizable additives such as polyprolene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, etc. Compounds such as functional (meth)acrylate compounds, epoxy poly (meth)acrylates, and polyester (meth)acrylates can be blended. Also,
If desired, modified resins such as epoxy resins, polyurethane resins, polybutadiene resins, and silicone resins, and additives such as silicone additives and fluorine additives can also be used.

〔Example〕

Hereinafter, the composition of the present invention will be specifically explained with reference to Examples. In the examples, parts mean parts by weight.

Example 1 264.8 g (1 mol) of dicyclohexylmethane-4,4'-diisocyanate and 30 g of polyethylene glycol (2-ethylhexyl) ether acrylate were placed in a 21-inch four-eye flask equipped with a stirrer, condenser, and thermometer.
7.1 g of polyethylene glycol ether acrylate, 1.02 g of methyl ethyl hydroquinone as a polymerization inhibitor, and 0.20 g of dibutyltin dilaurate as a catalyst, and after raising the temperature inside the flask to 40°C, add bisphenol to 100 g of polyethylene glycol ether acrylate. A monomer in which 287.7 g (0.8 mol) of polypropylene glycol ether was dissolved was added dropwise from the dropping funnel, and the internal temperature was gradually lowered to 6.
The temperature was raised to 5°C, and the reaction took place for a total of 4 hours. Furthermore, 7
After raising the temperature to 0°C, 58.1 g (0.5 mol) of 2-hydroxyethyl acrylate was added through the dropping funnel at 30°C.
The temperature was further increased to 75°C, and the NC value was 9.
Polyurethane polyacrylate was obtained by reacting until it reached 8% or more. Note that the amount of polyethylene glycol ether acrylate was 40% by weight of the total.

Next, 30 parts of polyethylene glycol ether acrylate as a diluent and 4 parts of 1-(4-isopropylphenyl)-2-hydroxy 2-methylpropane 1-one as a photopolymerization initiator were added to 70 parts of the reaction product and mixed. By melting, an optical fiber coating composition having a viscosity of 9620 cP (25° C.) was obtained.

1.0 l of the obtained coating composition was placed on a tin plate.
Apply thickly, use two mercury lamps 160W/cm, conveyor speed 5m/win, one pass, reflector.
It was irradiated with ultraviolet rays at a height of 10C11 and cured.

Table 1 shows the results of measuring the Shore hardness of the cured film, as well as the weight loss, gel fraction, and strength and elongation after hot water treatment at 80°C.
Shown below.

Example 2 In the same manner as in Example 1, dicyclohexylmethane-4
, 4'-diisocyanate and bisphenol A polypropylene glycol ether at a molar ratio of 3=2, and polyethylene glycol (2-ethylhexyl) ether acrylate as a diluent was added at 40% by weight of the total to form polyurethane. Polyacrylate was obtained.

Next, the above polyurethane polyacrylate was mixed and dissolved in the same formulation as in Example 1, and the viscosity was 2210 cP (25°C).
A coating composition for optical fiber was obtained.

The coating composition was cured and evaluated in the same manner as in Example 1. The results are shown in Table-■.

Example 3 In the same manner as in Example 1, dicyclohexylmethane-4
, 4'-diisocyanate and bisphenol A polypropylene glycol ether at a molar ratio of 2:1, and polyethylene glycol (2-ethylhexyl) ether acrylate as a diluent was added to 30% by weight of the total to produce polyurethane. Polyacrylate was obtained.

Next, the above polyurethane polyacrylate was mixed and dissolved in the same formulation as in Example 1, and the viscosity was 3740 cP (25°C).
A coating composition for optical fiber was obtained.

The coating composition was cured and evaluated in the same manner as in Example 1. The results are shown in Table-■.

Comparative Example 1 In the same manner as in Example 1, dicyclohexylmethane-4
, 4'-diisocyanate to bisphenol A polypropylene glycol ether in a molar ratio of 1:0.
．． Polyurethane polyacrylate was obtained by reacting at a ratio of 95% and the diluent polyethylene glycol (2-ethylhexyl) ether acrylate was 40% by weight of the total, but this product could not be used due to its high viscosity.

Comparative Example 2 17 parts of polyurethane polyacrylate obtained in the same manner as in Example 1, 83 parts of polyethylene glycol ether acrylate, and 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1- as a weight initiator. Mix and dissolve 4 parts of onion to obtain a viscosity of 500c.
An optical fiber coating composition of P (25° C.) was obtained.

The coating composition was cured and evaluated in the same manner as in Example 1. The results are shown in Table-■.

Comparative Example 3 In a 21 four-bottle flask equipped with a stirrer, a condenser and a thermometer, 1 mol of dicyclohexylmethane-4,4'-diisocyanate, 1.02 g of methyl ethyl hydroquinone as a polymerization inhibitor, and 0 of dibutyltin dilaurate as a catalyst. Prepare .20 g and set the temperature inside the flask to 40℃.
After raising the temperature to , gradually raise the temperature of a monomer in which 0.5 mol of bisphenol A polypropylene glycol ether was dissolved, and dropwise dropwise added from the dropping funnel over 2 hours, and dropwise over 30 minutes from the reaction tank over a total of 4 hours. and further 75℃
The temperature was raised to , and the reaction was carried out until the NC0 value became 98% or more to obtain polyurethane polyacrylate.

Next, 98 parts of the reaction product was added with 2 parts of polyethylene glycol (2-ethylhexyl) ether acrylate as a diluent and 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1- as a polymerization initiator.
Mix and dissolve 4 parts of 1,000 ml to give a viscosity of 100,000 cP.
Although the above composition (unmeasurable) was obtained, it could not be used due to its high viscosity.

Comparative Example 4 Dicyclohexylmethane-4,
Bisphenol A polypropylene glycol ether was reacted with 4'-diisocyanate at a molar ratio of 1:0.2, and the diluent polyethylene glycol (2-ethylhexyl) ether acrylate was adjusted to 30% by weight of the total. A polyurethane polyacrylate was obtained.

Next, mix and dissolve the same formulation as in Example 1, and check the viscosity? 20
A cP optical fiber coating composition was obtained.

The coating composition was cured and evaluated in the same manner as in Example 1. The results are shown in Table-■.

Table- ■ *1) Measured according to JIS-7113 using No. 2 dumbbells at a tensile speed of 50 mm/min (25°C) (
[Effects of the Invention] The coating composition of the present invention has little bleed-out even when immersed in hot water at 80°C for a long period of time, and there is no deterioration in strength and elongation performance, so it can be used as a protective coating composition for optical fibers. Are better.

Claims (1)

[Claims] 1. (a) A polyurethane polyacrylate or polyurethane polymethacrylate obtained by reacting a bisphenol-based alkylene oxide adduct as a polyol component with a diisocyanate compound and a hydroxyl group-containing acrylate or a hydroxyl group-containing methacrylate, ( b) a compound having one polymerizable double bond in one molecule,
and (c) a photopolymerization initiator, wherein the (a)/(b) weight ratio is from 20/80 to 95/5, and the amount of (c) is from 0.1 to 10% by weight based on the weight of the composition. %. 2. Dicyclohexylmethane-4,4'-diisocyanate whose component (a) is represented by the following formula [I] ▲Math.
There are chemical formulas, tables, etc. ▼ [I] and the following general formula [II] ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ [II] (In the formula, R_1 and R_2 are hydrogen or methyl groups, R
_3 and R_4 are alkylene groups, and n is an integer of 1 to 10. ) A polyurethane polyacrylate obtained by reacting a bisphenol alkylene oxide adduct represented by [
The optical fiber coating composition according to claim 1, wherein the molar ratio of I]/[II] is from 1/0.3 to 1/0.9. 3. Claim 1 in which the component (b) is a compound represented by the following formula [III] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (wherein n is an integer from 1 to 5) Or the composition according to item 2.