JPS6390525A - Curable resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition capable of giving cured products with small variation in the modulus, for use in optical glass fiber coating, by incorporating a specific urethane acrylate with specified quantities of trisacryloyloxyalkyl isocyanurate and a monofunctional unsaturated compound. CONSTITUTION:The objective composition comprising (A) 30-70wt% of an urethane acrylate prepared by reaction between (i) polyisocyanate, (ii) polyether polyol with a number-average molecular weight 600-4,000 (pref. at least partly made up of polytetramethylene ether glycol with a number-average molecular weight 800-2,000), (iii) monohydroxyalkyl acrylate and (iv) a compound of formula HO-R1-S-R2-OH (R1 and R2 are each alkylene), (B) 10-30wt% of a trisacryloyloxyalkyl isocyanurate, and (C) a monofunctional unsaturated compound (pref. N-vinylpyrrolidone or isobornyl acrylate).

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a curable resin composition, and particularly to a resin composition for coating a glass fiber for optical transmission (hereinafter abbreviated as optical fiber). Specifically, the cured product has a small change in elastic modulus from low to high temperatures, has high elongation, has excellent heat resistance and water resistance, and has a resin composition for coating optical fibers that generates little hydrogen from the cured product. relating to things.

<Conventional technology> Optical fibers are fragile, easily damaged, and have poor flexibility, and are easily broken by the slightest external force.Additionally, when mechanical lateral pressure is applied, the light transmitted by microbending is weakened, resulting in transmission loss. will occur. For this reason, the glass surface is first coated with a material that has a very low modulus of elasticity to minimize microbending, and then coated with a second coat of a material that is flexible and has a high modulus of elasticity. It is being said. Desirable properties for this secondary coating include maintaining a high modulus of elasticity even in environments ranging from low to high temperatures, as well as having excellent flexibility, water resistance, and heat resistance. Further, these coating resins must be made of materials that generate extremely little hydrogen, which causes an increase in transmission loss over time.

Means for Solving the Problems As a result of intensive studies on combinations of various urethane acrylates and photopolymerizable monomers, the present inventors have developed a resin composition for secondary coating that generates less hydrogen according to the present invention. I have completed something.

That is, the present invention relates to a polyisocyanate, a polyether polyol having a number average molecular weight of 600 to 4000, a monohydroxyalkyl acrylate, and the following general formula (I).
The compound represented by the compound HO-Rr -5-R1-OH (
I) (R1 and R2 are alkylene groups) 80 to 70% by weight based on the resin composition of urethane acrylate obtained by reacting with B)) 10 to 70% based on the resin composition of lith acryloyloxyalkyl isocyanurate 80! jL% and C) a monofunctional unsaturated compound.

The polyisocyanate used in the present invention may be aromatic, aliphatic, alicyclic, or araliphatic. Examples include tolylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and the like.

Number average molecule used in the present invention! 600-400
Examples of polyether polyols having a molecular weight of 0 include polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol, but in particular polytetramethylene ether glycol has a number average molecular weight of 8.
It is preferable to use at least a part of the particles having a particle size of about 00 to 2,000.

Examples of the monohydroxyalkyl acrylate used in the present invention include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate.

Examples of compounds represented by the general formula (RI) used in the present invention include thiodiethanol and thiodibrobanol. By using this compound, the amount of hydrogen generated from the cured resin product is reduced.

The urethane acrylate of the present invention contains the above-mentioned polyisocyanate, polyether polyol, monohydroxyalkyl acrylate, and the compound represented by the general formula (X) in an equivalent ratio of NCO groups and 10H groups of about 0.8 to 1.2, preferably It is obtained by reacting at a ratio of 0.0696 to 1.05.

As for its manufacturing method, various known methods can be used.

The respective proportions of the polyether polyol, monohydroxyalkyl acrylate and the compound of general formula (I) are as follows.

0.5 to 10 mol of monohydroxyalkyl acrylate, general formula (
0.1 to 10 mol of compound I), preferably 1 to 4 mol of monohydroxyfurkyl acrylate per mol of polyether polyol, 0.4 mol of compound of general formula (I)
~8 mol.

The content of this urethane acrylate should be 80-70% by weight, preferably 40-60% by weight, based on the resin composition.

If the content of this urethane acrylate exceeds the above-mentioned value, it becomes too viscous and difficult to use. On the other hand, if it is less than the above value, the viscosity will be too low and the coating will not be successful.

Examples of the trisacryloyloxyalkyl isocyanurate used in the present invention include trisacryloyloxyethyl isocyanurate, trisacryloyloxypropylisocyanurate, and the like. This trisacryloyloxyalkyl isocyanurate is high 1
゛g exceeds 80ifi% according to the present invention,
The elongation of the cured product is extremely reduced, and if it is less than 10% by weight, the elastic modulus at high temperatures is significantly reduced.

The monofunctional unsaturated compound used in the present invention preferably contains at least one of N-vinylpyrrolidone and isobornyl acrylate. Monofunctional unsaturated compounds other than those listed above are not particularly limited, but include, for example, tetrahydrofurfuryl acrylate,
2-Hydroxy-8-phenyloxypropyl acrylate, butoxyethyl acrylate, lauryl acrylate, stearyl acrylate, benzyl acrylate, hexyldiglycol acrylate, 2- and droxyethyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenoxy Examples include ethyl acrylate, dicyclopentadiene acrylate, polyethylene glycol acrylate or polypropylene glycol acrylate, and nonylphenoxyethyl cellosolve acrylate.

The content of monofunctional unsaturated compounds is preferably 10 to 60% by weight based on the resin composition.

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

In the present invention, the photopolymerization initiator to be blended as necessary is not particularly limited, but examples include benzophenone,
Acetophenone, 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.

<Effects of the Invention> The cured product of the resin composition of the present invention has high elastic modulus and elongation from low to high temperatures, and provides excellent physical properties such as water resistance and heat resistance.

Moreover, the amount of hydrogen generated from the cured product is extremely small. As a result, the optical fiber coated with the cured product has excellent properties.

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

Example 1 Tolylene diisocyanate 1811 was charged in a 500CC four-bottle flask equipped with a thermometer, a stirrer, and a reflux condenser, and 60% of 2-hydroxyethyl acrylate 58f was charged.
After gradually adding dropwise at 60°C, the mixture was reacted for 2 hours at 60°C.Next, polytetramethylene ether glycol 250f with a number average molecular weight i1000, thiogentanol 801
, and 0.5F of tin octylate, and heated at 70"C for 3
After reacting for a time and cooling, urethane acrylate 469f was obtained.

40 f of trisacryloyloxyethyl isocyanate per 100 f of the obtained urethane acrylate!
, isobornyl acrylate 40f, N-vinylpyrrolidone 201 and benzyl dimethyl ketal 61 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 heated at a conveyor speed of 20r using a 120W metal halide lamp.
Cured at n/min.

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

Example 2 Tolylene diisocyanate 141f was charged into a four-bottle flask similar to that used in Example 1, and 2-hydroxyethyl acrylate 68f was gradually added dropwise at 60°C.
The reaction was carried out at 60-C for 2 hours. Next, number average molecule fit
000 polytetramethylene ether glycol 189
f, thiodibrobanol 52y1 tin octylate 0.
41 and reacted at 70"C for 3 hours. After cooling, 4
45F urethane acrylate was obtained.

Trisacryloyloxyethyl isocyanate (40f), isobornyl acrylate (40f%), N-vinylpyrrolidone (20F) and benzyl dimethyl ketal (6F) were added and mixed to the obtained urethane acrylate (100F) to obtain the desired composition. Table 1 shows the physical properties of the film cured in the same manner as in Example 1.

Example 8 Tolylene diisocyanate 78f was charged into a four-hole flask similar to that used in Example 1, and 2-hydroxyethyl acrylate 8511 was gradually added dropwise at 60°C, followed by reaction at 60°C for 2 hours.

Thereafter, a mixture of 105 f of polytetramethylene ether glycol with a number average molecular weight of 2000, 105 g of polypropylene glycol with a fi average molecular weight of 2000, 24 f of thiodiethanol, and 0.4 f of tin octylate was added, and 7
After reacting at 0°C for 8 hours and cooling, 847g of urethane acrylate was obtained.

40jl of trisacryloyloxyethyl isocyanurate per 100f of the obtained urethane acrylate;
80 g of N-vinylpyrrolidone and 80f1 acrylate represented by the structural formula (n is an integer of 5 or less) and 4tI benzyl dimethyl ketal were added and mixed to obtain the desired composition. Table 1 shows the physical properties of the film cured in the same manner as in Example 1.

Example 4 The resin composition obtained in Example 1 was cured in the same manner as in Example 1 to obtain a cured sheet. Place the sheet in the air
The mixture was heated at 20"C for 24 hours, and the generated hydrogen was analyzed by gas chromatography. The results are shown in Table 2.

Comparative Example 1 Tolylene diisocyanate 181F was charged in the same flask as in Example 1, and 2-hydroxyethyl acrylate 58F was gradually added dropwise at 60° C., followed by reaction at 60”C for 2 hours.

Next, polytetramethylene ether glycol 250f11.4-butanediol 2 with number average molecular ff11000
8f1 and 0.51 tin octylate were added, and the mixture was reacted at 70"C for 8 hours to obtain 462f urethane acrylate after cooling.

40 N of trisacryloyloxyethyl isocyanurate per 100 f of the obtained urethane acrylate
, isobornyl acrylate 4011, N-vinylpyrrolidone 209, and benzyl dimethyl ketal 61/ were added and mixed to obtain a resin composition. This composition was cured in the same manner as in Example 1 to obtain a cured sheet. Hydrogen generated from the sheet was analyzed in the same manner as in Example 4. The results are shown in Table-2.

Table-2 Example 5 Outer diameter 2 primary coated with resin with elastic modulus of 0.10 kg/-
The compositions of Examples 1-5-8 were each applied to the surface of a 60 μm optical fiber, and then cured by irradiation with purple 9JF rays. The outer diameter of each optical fiber after coating was 800 μm, and no increase in transmission loss was observed due to the coating, and -40°
No increase in transmission loss was observed from C to +80 C.

As explained above, the cured product of the resin composition of the present invention has a high modulus of elasticity and sufficient elongation from low to high temperatures, is 5-aqueous, has an RF! It has excellent thermal properties, generates very little hydrogen from the cured product, and does not increase optical transmission loss, making it suitable as an optical fiber coating material.

Claims (1)

[Claims] A) Polyisocyanate, number average molecular weight is 600 to 40
Urethane acrylate obtained by reacting a polyether polyol of 00, monohydroxyalkyl acrylate, and a compound represented by the following general formula (I) HO-R_1-S-R_2-OH (I) (R_1 and R_2 are alkylene groups) B) 10 to 30% by weight based on the resin composition of trisacryloyloxyalkyl isocyanurate, and C) a monofunctional unsaturated compound. A curable resin composition. (2) The curable resin composition according to claim 1, wherein the monofunctional unsaturated compound is at least one of N-vinylpyrrolidone and isobornyl acrylate.