JPS6296508A - Curable resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a curable resin composition suitable for a plastic cladding layer of a plastic-coated optical fiber.

Conventionally, plastic-coated optical fibers have a core of glass fiber and a cladding layer of plastic.
Although its transmission characteristics are inferior to that of silica-based optical fibers, it has a high numerical aperture and is inexpensive, so it is often used for short-distance optical transmission.

Since the cladding layer needs to have a lower refractive index than the core, fluorine-containing resin polymers such as polyfluoroalkyl acrylate are used in the plastic cladding layer to lower the refractive index. However, these could not be said to fully satisfy the characteristics required for plastic-coated optical fibers, such as flexibility and appropriate temperature dependence of elastic modulus.

As a result of intensive study on the above-mentioned problems, the inventor has found that
It has been found that by using a curable resin composition having the following composition as a cladding material, the physical properties of the plastic-coated optical fiber can be significantly improved and the above problems can be solved.

That is, the present invention provides polyfluoroalkyl (meth) represented by the following general formula [1] of 15 to 35 Nji% of urethane acrylate oligomer, 10 to 25% by weight of polyfunctional acrylate, and 1% of 50 to 75iH of the resin composition. ) A curable resin composition containing acrylate.

(However, in the formula, X is FlEI or C/iy is H or CHs
; tn is an integer of 1 to 6; n is an integer of 2 to 1O;

) The urethane diacrylate oligomer used in the present invention is
It can be produced by a known method, for example, by reacting a diisocyanate with a polyol and a hydroxyalkyl acrylate. Suitable diisocyanates include isophorone diisocyanate, 2.4
-Aliphatic or aromatic compounds such as tolylene diisocyanate or its isomers and hexamethylene diisocyanate, with particular preference being given to tolylene diisocyanate or isophorone diisocyanate.

Suitable polyols include, for example, a number average molecular weight of 10
00 or higher, polypropylene glycol, polytetramethylene glycol, or a polyester polyol of the above polyol and a dibasic acid such as adipic acid.

Also suitable hydroxyalkyl 7-acrylates include, for example, 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate.

If this urethane diacrylate oligomer exceeds 35% by weight as defined in the present invention, the proportion of polyfluoro(meth)acrylate in the resin composition, which is necessary for lowering the refractive index of the cured product, will decrease relatively. As a result, the refractive index of the cured product exceeds the upper limit of the refractive index value required for the cladding layer, and the transmission characteristics of the optical fiber deteriorate.

Moreover, if it is less than 15% by weight and 11%, the elongation of the cured product decreases, leading to a decrease in the flexibility of the optical fiber. Moreover, the viscosity of the resin composition decreases, making it difficult to coat the core.

The polyfunctional acrylate used in the present invention is 1.6
- Difunctional acrylates such as hexanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol sialylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris(2-acryloxyethyl) isocyanurate, etc. In particular, octafunctional acrylates are preferably used.

This polyfunctional acrylate is 25:If1 according to the present invention.
%, as in the case of the urethane acrylate oligomer described above, the proportion of polyfluoro(meth)acrylate in the resin composition necessary for lowering the refractive index decreases relatively, and as a result, the cured product The refractive index of the optical fiber exceeds the upper limit of the refractive index value required for the cladding layer, and the transmission characteristics of the optical fiber deteriorate. In addition, the elongation of the cured product is reduced and the flexibility of the optical fiber is also reduced.

However, if it is lower than ioim%, the appropriate temperature and pressure dependence of the elastic modulus of the cured product will deteriorate.

The polyfluoroalkyl (meth)acrylate used in the present invention is represented by the following general formula.

(However, in the formula, X is F, H or (:/, Y is H or CHs
; m is 1 to 6 (D integer in is an integer of 2 to 1o(7).) Examples of this acrylate include 1,1°2.2-tetrafluoropropyl acrylate, 1.1.2.2-
Tetrafluoropropyl methacrylate, 1.1.2
, 2,8,8,4.4-octafluorobentyl acrylate, and 1°1.2,2.8.8,4.4-octafluoropentyl methacrylate.

If this polyfluoroalkyl(methacrylate) exceeds 751% failure as defined in the present invention, the flexibility, elastic modulus, and temperature dependence of the cured product decrease to such an extent that it cannot be put to practical use. If it is less than 1%, the refractive index of the cured product exceeds the upper limit of the refractive index value required for the cladding layer, and the transmission characteristics of the optical fiber deteriorate.

The curable resin composition of the present invention may further contain various additives such as a photopolymerization initiator, a monofunctional acrylate, a silane coupling agent, a peeling agent, an ultraviolet absorber, an antioxidant, and a filler, as necessary. be able to.

In the present invention, the photopolymerization initiator to be blended as necessary is not particularly limited, but examples include benzophenone,
Aretophenone, benzoin, benzoin isobutyl ether, benzoin isopropyl ether, benzoin ethyl ether, 4.4-bisdimethylaminobenzophenone, benzyl dimethyl ketal, 2-chlorothioxanthone, 2.4-dimethylthioxanthone, 2.2
'-Diisopropylthioxanthone or l-hydroxycyclohexylphenyl ketone is used.

EXAMPLES The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Tolylene diisocyanate) 84.8P and polytetramethylene ether glycol 200? with a number average molecular weight of 2000 were placed in a 11 four-bottle flask equipped with a thermometer, stirrer and reflux condenser. After preparing and reacting at 70℃ for 2 hours,
2-Hydroxyethyl acrylate 24. Add OF,
After further reaction at 70° C. for 2 hours and cooling, oligomer 258.8) was obtained. Then trimethylolpropane triacrylate 155F, 1.1,2,2.8.8.4
．． 4-octafluoropentyl acrylate 619? ,
Benzyl dimethyl ketal 21? were added and mixed to obtain the desired composition. This composition was coated on a glass plate to a thickness of 250 tons, and then cured using a 120 W metal halide lamp at a conveyor speed of 20 m/min.

Table 1 shows the results of measuring the physical properties of the cured film.

Example 2 In a four-necked flask similar to that used in Example 1, 50.0% of isophorone diisocyanate was charged. After charging Of and gradually dropping 2-hydroxyethyl acrylate 26.0P at 90°C, the mixture was reacted at 90°C for 2 hours. Next, polytetramethylene ether glycol 2 with a number average molecular weight of 2000
24P was added and reacted at 90'e for 8 hours. After cooling, 8
00? oligomers were obtained.

Next, tris(2-acryloxyethyl)isocyanurate 150P, 1,1.2.2°8.8,4.4-octafluoropentyl acrylate 550y-, benzyl dimethyl ketal 80? were added and mixed to obtain the desired composition.

Table 1 shows the results of measuring the physical properties of a film cured using the above composition in the same manner as in Example 1.

Example B A four-bottle flask similar to that used in Example 1 was charged with 84.2 P of isophorone diisocyanate, and 2- and 11.9 P of droxyethyl acrylate were gradually added dropwise at 90°C. Allowed time to react. Next, polytetramethylene ether glycol 2 with a number average molecular weight of 2000
Add G8.9P, react at 90°C for 8 hours, and after cooling,
A 250F oligomer was obtained. Next, tris(acryloxyethyl)isocyanurate 160? , 1.1.2.
600i of 2-tetrafluoropropyl acrylate and 80p of benzyl dimethyl ketal were added to obtain the desired composition.

Table 1 shows the results of measuring the physical properties of a film cured using the above composition in the same manner as in Example 1.

Table 1 Example 4 The compositions of Examples 1 to 8 were each applied to a glass fiber having a diameter of 200 μm, and then photocured by ultraviolet irradiation (lamp output 20+2 lights) to form a cladding layer. The outer diameter of the optical fiber after being coated with the cladding layer was 800 μm.

In addition to these optical fibers, the cured product has an elastic modulus of 161/
All optical fiber cables coated with San's UV-curable resin had excellent flexibility and m-degree dependence of elastic modulus.

Claims (1)

[Scope of Claims] 15 to 35% by weight of the resin composition of urethane acrylate oligomer, 10 to 25% by weight of polyfunctional acrylate, and 50 to 75% by weight of polyfluoroalkyl represented by the following general formula [1] A curable resin composition containing (meth)acrylate. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, X is F, H or Cl; Y is H or CH_3;
m is an integer of 1 to 6; n is an integer of 2 to 10. )