JP3402393B2 - Resin composition, coating composition for optical fiber, and cured product thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a specific urethane (meth)
The present invention relates to a resin composition using an acrylate, a coating composition for an optical fiber for optical transmission, and a cured product thereof.

[0002]

2. Description of the Related Art Optical fibers are classified into inorganic glass type and synthetic resin type such as poly (methyl methacrylate). Both systems consist of a highly transparent core with a high refractive index and a sheath with a low bending rate.
As a clad material, a polymer of a fluorine-containing monomer such as a silicon compound or polyfluoroalkyl acrylate having a lower refractive index than before has been proposed and implemented. For example, poly (methyl methacrylate) is used as the core material, and fluorinated alkyl group-containing (meth) is used as the cladding material.
Acrylate polymer, copolymer of fluorinated alkyl group-containing (meth) acrylate and other monomer, or
Poly (tetrafluoroethylene) Poly (vinylidene fluoride / tetrafluoroethylene), Poly (vinylidene fluoride /
A method using a fluoropolymer such as hexafluoropropylene) is known. (For example, JP-A-59-8420.
3, JP-A-59-84204, JP-A-59-9811
6, JP-A-59-147011, JP-A-59-2040
02).

[0003]

In the method of forming the clad portion with the fluoropolymer, since the melt or solution of the fluoropolymer at high temperature is coated, the thickness tends to be uneven. Further, the adhesion between the core portion and the clad portion is not sufficient, and various external factors, such as bending and temperature change, tend to cause delamination, which causes a problem in durability and the like. Further, in the production method of applying the melt or solution of the fluoropolymer, it takes a long time to cure the clad portion, and in the solution application method, in particular, it is necessary to completely remove the solvent out of the system. However, there were drawbacks in productivity, safety, economy, etc.

[0004]

In order to solve the above problems, the inventors of the present invention have earnestly studied, and as a result, by using a specific urethane (meth) acrylate (A), the curing rate was high and the bending rate was high. The present invention has been completed by successfully providing a resin composition suitable for a clad material of a fiber for optical transmission which gives a cured product having a low adhesiveness to a core. That is, the present invention relates to a reaction product (I) of a fluorine compound (a) having one epoxy group in the molecule and a fluorine compound (b) having two carboxyl groups in the molecule, and an organic polyisocyanate (c). The present invention relates to a resin composition, a coating composition for an optical fiber, and a cured product thereof, which contains a urethane (meth) acrylate (A) which is a reaction product of a hydroxyl group-containing (meth) acrylate (d). .

Urethane (meth) used in the present invention
The acrylate (A) is a reaction product (I) of a fluorine compound (a) having one epoxy group in the molecule and a fluorine compound (b) having two carboxyl groups in the molecule, and an organic polyisocyanate (c). Can be obtained, and then a hydroxyl group-containing (meth) acrylate (d) is reacted. Specific examples of the fluorine compound (a) having one epoxy group in the molecule include, for example,

[0006]

[Chemical 1]

And the like. Specific examples of the fluorine compound (b) having two carboxyl groups in the molecule include, for example,

[0008]

[Chemical 2]

And the like. Regarding the reaction between the component (a) and the component (b), it is preferable to react about 1 equivalent of the carboxyl group of the component (b) with 1 equivalent of the epoxy group of the component (a). The reaction temperature is preferably 50 to 200 ° C,
70-120 degreeC is especially preferable. The reaction can be accelerated by using a catalyst. Specific examples of such a catalyst include catalysts such as triethylamine, benzylmethylamine, methyltriethylammonium chloride, tetraethylammonium chloride and triphenylphosphine. The amount of the catalyst used is 0.
001-5.0 wt% is preferable, and 0.01-3.
0% by weight is preferred. The reaction time is preferably 3 to 48 hours. Next, the reaction product (I) obtained by this reaction is reacted with the organic polyisocyanate (c) (eg, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, etc.). It is preferable to react 1.1 to 2 equivalents of the isocyanate group of the organic polyisocyanate (c) with 1 equivalent of the hydroxyl group of the reaction product (I), and particularly preferably 1.3 to 2.0 equivalents. The reaction temperature is preferably 40 to 100 ° C, particularly 7
0-90 degreeC is preferable. The reaction time is preferably 3 to 30 hours. Next, a hydroxyl group-containing (meth) acrylate (d) (e.g., 2-hydroxyethyl (meth) acrylate, 1,4) is added to 1 equivalent of isocyanate group of the reaction product of the reaction product (I) and the organic polyisocyanate (c). -Butanediol mono (meth) acrylate, 2-hydroxypropyl (meth) acrylate,

[0010]

[Chemical 3]

Etc. It is preferable to react 0.9 to 3 equivalents of the hydroxyl group of 1), and particularly preferably 1 to 1.2 equivalents. The reaction temperature is preferably 40 to 100 ° C, particularly preferably 70 to 90 ° C. The reaction time is preferably 3 to 30 hours. Various (meth) acrylic acid esters can be used as a component other than the urethane (meth) acrylate (A) in the resin composition or the coating agent for an optical fiber (hereinafter, simply referred to as a composition) of the present invention. As a specific example, for example,

[0012]

[Chemical 4]

And the like. These (meth) acrylic acid esters may be used alone or in combination of two or more kinds at an arbitrary ratio, if necessary. The amount used is preferably in the range of 0 to 80% by weight in the composition of the present invention, and particularly preferably in the range of 5 to 60% by weight.

When the composition of the present invention is cured by ultraviolet light,
It is preferable to use a photopolymerization initiator. As the photopolymerization initiator, any known photopolymerization initiator may be used, but one having good storage stability after blending is preferable. Examples of such a photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, and benzyl dimethyl ketal. Particularly preferable examples include 1-hydroxycyclohexyl phenyl ketone and the like. These photopolymerization initiators may be used alone or in a mixture of two or more kinds at any ratio. The amount used is usually 0 to 10% by weight of the composition, and preferably 0.5 to 5% by weight.

The composition of the present invention may further contain a silane coupling agent, an antioxidant, a polymerization inhibitor, if necessary.
Various additives such as a light stabilizer can also be added. The composition of the present invention can be obtained by uniformly mixing the components. The cured product of the composition of the present invention can be obtained by UV irradiation by a conventional method.

Various methods known in the art can be used to apply the coating composition for an optical fiber according to the present invention to a substrate (optical transmission fiber core wire).
For example, a die coating method, a dipping method and the like can be mentioned. Examples of the optical fiber core include quartz and plastics such as polystyrene and polycarbonate. When forming the clad portion of the optical transmission fiber, the thickness of the coating film of the coating agent of the present invention is not particularly limited, but is usually preferably about 10 to 300 microns. In the case of curing and polymerization, it is preferable to use ultraviolet rays having a high-pressure mercury lamp, an ultra-high-pressure mercury lamp or a metal halide lamp as a light source, and it is desirable to irradiate in a nitrogen gas in order to improve the efficiency of curing.

The composition of the present invention can be used not only as a clad material for an optical transmission fiber but also as a coating agent for glass or plastics, a sealing agent for LED, etc. by utilizing its low refractive index.

[0018]

EXAMPLES The present invention will be described in more detail below with reference to examples. The parts in the synthetic examples and the examples are parts by weight. Synthesis Example of Urethane (Meth) Acrylate (A) Synthesis Example 1 130 parts of the compound of the formula (8), 76.1 parts of the compound of the formula (12) and 0.43 part of triphenylphosphine are charged, and the mixture is heated at about 90 ° C. Reacted for 12 hours, and the reaction product (1-1)
(Hydroxyl equivalent 595.9) was obtained. Next, 54.7 parts of trimethylhexamethylene diisocyanate was charged thereinto and reacted at 80 ° C. for 15 hours, then 365.5 parts of the compound of the above formula (15) was charged and reacted at 80 ° C. for 11 hours,
Urethane acrylate (A-1) was obtained. The product obtained has a refractive index (23 ° C) and a viscosity of 1.3680 (23 ° C).
It is 7410 cps.

Synthesis Example 2 Urethane acrylate (A-2) was prepared in the same manner as in Synthesis Example 1 except that 54.7 parts of trimethylhexamethylene diisocyanate in Synthesis Example 1 was changed to 38.9 parts of hexamethylene diisocyanate. Obtained. The product has a refractive index (23 ° C) of 1.3660 and a viscosity (23 ° C) of 8540.
cps.

Example 1 Urethane acrylate (A-1) 97 obtained in Synthesis Example 1
And 1 part of 1-hydroxycyclohexyl phenyl ketone (Ciba Geigy, Irgacure 184) were mixed to obtain a resin composition A of the present invention. This resin composition A was applied on a glass plate to a thickness of 200 μm, and then irradiated with ultraviolet rays of 500 mJ / cm ^{2 with} a high pressure mercury lamp in a nitrogen atmosphere to obtain a cured product. The properties of the obtained cured product are shown in Table 1.

Example 2 Urethane acrylate (A-2) 97 obtained in Synthesis Example 2
Parts and 1 part of 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Geigy, Irgacure 184) were mixed to obtain a resin composition B of the present invention. The properties of the cured product obtained in the same manner as in Example 1 are shown in Table 1.

Example 3 Urethane acrylate (A-1) 78.
5 parts, 21.5 parts of the compound of the above formula (27) and 3 parts of 1-hydroxycyclohexyl phenyl ketone were mixed to obtain a resin composition C of the present invention. The properties of the cured product obtained in the same manner as in Example 1 are shown in Table 1.

[0023]

Table 1 Resin composition ABC hardness (Shore D) 30 26 20 Young's modulus (kg / mm ² ) 7.5 6.0 5.0 Break elongation (%) 65 75 78 Break strength (kg / Mm ² ) 0.5 0.5 0.4 Refractive index (23 ° C) 1.3790 1.3765 1.3799

Evaluation method Hardness (Shore D): JIS using a cured product of 200μ
It was measured according to the method of Z 2246. Young's modulus, elongation at break, breaking strength: Measured according to the method of JIS K 7113 using a cured product of 200 μ.

As is clear from the evaluation results of Table 1, it is clear that the curing rate is high, the cured product has elongation, and the refractive index is low.

[0026]

The resin composition of the present invention has a high curing rate,
The resin coating obtained is flexible, has a low refractive index,
It is particularly suitable for the cladding layer of optical transmission fibers.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ identification code FI G02B 6/44 301 C03C 25/02 B (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 18/67 C08G 18 / 30 C08F 299/06 C09D 175/16

Claims (3)

(57) [Claims] 1. A reaction product (I) of a fluorine compound (a) having one epoxy group in the molecule and a fluorine compound (b) having two carboxyl groups in the molecule, and an organic polyisocyanate (c). Hydroxyl group-containing (meth) acrylate (d)
Urethane (meth) acrylate (A) which is a reaction product with
A resin composition comprising: 2. A coating composition for an optical fiber, which comprises the urethane (meth) acrylate (A) according to claim 1. 3. A cured product of the composition according to claim 1 or 2.