JPH069738A - Curable resin composition - Google Patents

Abstract

PURPOSE:To obtain a curable resin composition improved in adhesion and heat resistance by adding a free radical generator to a mixture comprising a vinyl ester resin containing dispersed rubber particles of a specified particle diameter and a polymerizable monomer. CONSTITUTION:A vinyl ester resin is mixed with 1-30wt.% rubber particles of a particle diameter of 1mum or smaller at 30-60 deg.C to obtain a rubber-containing vinyl ester resin. A free radical generator is added to a mixture comprising at least 50wt.% this resin and at most 50wt.% polymerizable monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial field of a vinyl ester resin composition for FRP, which is required to have solvent-free or halisolid, rapid curing, low viscosity, adhesiveness and heat resistance.

[0002]

2. Description of the Related Art A vinyl ester resin produced from an epoxy resin and an unsaturated fatty acid typified by (meth) acrylic acid is solvent-free, has low viscosity, and can be heat-cured and photocured by rapid curing.
From the standpoint of excellent workability, etc., FRP, paints, adhesives, sporting goods, electronic parts, electrical equipment, automobile parts,
Widely used in other household items.

However, the vinyl ester resin produced from the conventional epoxy resin has the above-mentioned advantages, but when it is used for FRP because of insufficient adhesive strength and flexibility, it is subject to external impact. Since there is a defect that delamination between glass cloths is likely to occur, improvement is required.

In order to improve this drawback, for example, after modifying the epoxy resin with a butadiene acrylonitrile rubber having a functional group capable of reacting with an epoxy group, it is converted into a vinyl ester, or a rubber component having a vinyl group at the end is added. However, even though the adhesiveness and flexibility are improved, the heat resistance is reduced.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to improve the adhesive strength, which has been a drawback of conventional vinyl ester resins, as described above, without lowering the heat resistance.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is to improve the adhesiveness by adding a radical generator to a mixture of a vinyl ester resin and a polymerizable monomer in which 1 to 30% by weight of a rubber having a particle diameter of 1 μm or less is dispersed. And a curable resin composition having excellent heat resistance.

The present invention will be described in detail below. Examples of the vinyl ester resin used in the present invention include a reaction product of an epoxy resin and an unsaturated carboxylic acid. Examples of the epoxy resin include commercially available epoxy resins, for example, glycidyl ethers represented by bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, brominated bisphenol A diglycidyl ether, and alicyclic epoxy. Resins, glycidyl esters, glycidyl amines, novolac type epoxy resins, and the above-mentioned epoxy resins, bisphenol A, bisphenol F,
Examples thereof include copolymers of bisphenols represented by bisphenol S, brominated bisphenol A, brominated bisphenol F, and the like. The unsaturated carboxylic acid may be acrylic acid, methacrylic acid, or the like. is there.

Examples of the polymerizable monomer used in the composition of the present invention include unsaturated carboxylic acids represented by acrylic acid and methacrylic acid, and compounds having an unsaturated bond such as styrene, acrylate and methacrylate. .
The amount of the polymerizable monomer used is determined in consideration of the impregnation property with respect to the glass fiber or the glass cloth, but if the amount of the monomer used is too large, the performance as the FRP is lowered, and therefore it is preferably 50% or less.

The fine particle rubber of the composition of the present invention is any of butadiene rubber, styrene butadiene rubber, nitrile butadiene rubber, isoprene rubber, chloroprene rubber, ethylene propylene rubber, butyl rubber, urethane rubber, silicone rubber and other commercially available rubbers. However, if metal ions are present during the vinyl esterification reaction, gelation tends to occur and the storage stability of the vinyl ester resin will deteriorate, so the particulate rubber used in this composition contains almost no metal ions. Must be rubber manufactured by law. The amount of particulate rubber used is 1 to
30% by weight, preferably 2 to 20% by weight is good, and if it is less than 1%, it does not contribute to the improvement of the adhesive strength as FRP and is 30%.
If the amount is larger, the effect of improving the adhesive strength with respect to the amount of rubber used is reduced, and the viscosity becomes high, so that the impregnation property for glass fiber or glass cloth deteriorates.

Further, the particle diameter of the fine particle rubber is required to be 1 μm or less, and when the particle diameter is increased, the impregnating property with respect to the glass fiber or the glass cloth is deteriorated and the adhesive strength of the obtained cured product is not so improved.

As the radical generator of the composition of the present invention,
Cumene hydroperoxide, benzoylperoxide, methyl ethyl ketone peroxide, azobisisobutyronitrile, or any other commonly used radical generator may be used.

[0012]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. Example 1 Epototo YD-128 (Bisphenol A diglycidyl ether manufactured by Tohto Kasei Co., Ltd., epoxy equivalent 187)
g / eq) to 100 parts, and 5 parts of nitrile butadiene rubber (hereinafter referred to as NBR) finely pulverized using Tarbomill (manufactured by Tarbo Kogyo Co., Ltd.) is added at 30 to 60 ° C.
After high speed mixing and dispersion for 10 minutes using a homodisper (shear stirring mixer manufactured by Tokushu Kika Kogyo Co., Ltd.), a four-necked flask equipped with a stirrer, a thermometer, a cooling tube, an air introducing device, and a dropping device is provided. Then, add 0.3 parts of hydroquinone and 0.5 parts of triethylamine, and add 80 parts while flowing air.
At ~ 120 ° C add 39 parts of acrylic acid over 3 hours,
The esterification reaction was carried out until the oxidation became 5 mgKOH / g or less, and 95 parts of styrene was added to obtain a rubber-containing vinyl ester resin. The particle size of the rubber as observed by an electron microscope was 0.5 μm or less.

Examples 2 to 6 Vinyl ester resins having the compositions shown in Table 1 were prepared under the same conditions as in Example 1.

Comparative Example 1 A vinyl ester resin was obtained by using the same conditions as in Example 1 except that no particulate rubber was used.

Comparative Examples 2 and 3 Table 1 using NBR coarsely pulverized by terbomill
A vinyl ester resin having the composition shown in Example 1 was obtained in the same manner as in Example 1. The particle size of the rubber as observed by an electron microscope was 2.5 μm or less.

Comparative Example 4 100 parts of YD-128 and Hiker-CTBN-130
40 parts of 0X13 (Ube Industries, Ltd. product name terminal carboxyl group acrylonitrile butadiene rubber) and 0.1 part of triethylamine were added and reacted at 160 ° C. for 4 hours, then cooled to 80 to 120 ° C. and hydroquinone 0.3.
Part, triethylamine 0.4 part, acrylic acid 37
Parts were used to obtain a vinyl ester resin under the same conditions as in Example 1. The compositions of Comparative Examples 1 to 4 are summarized and shown in Table 1.

[0017]

[Table 1]

To 100 parts of the vinyl ester resins obtained in Examples 1 to 6 and Comparative Examples 1 to 4, 1 part of cumene hydroper oxide was added, and a glass cloth (WEA-18K-105BZ2 manufactured by Nitto Boseki Co., Ltd.) was added. Impregnation, and the 8 plies are 160 ° C. × 10 Kg / cm ² × 30 mi in a mold.
n. Cured under the conditions of 1.6 mm thick (resin + rubber)
A 40% FRP was made. The properties as the FRP are shown in Table 2.

[0019]

[Table 2]

In Table 2, * 1, * 2 and * 3 are as follows. * 1 ... The interlayer adhesion strength is 1 cm for one surface of the glass cloth.
The width was measured by a 90 ° peel test. * 2: To compare the heat resistance of FRP at the glass transition point,
DuPont Viscoelasticity Spectrometer-DMA-982
Using 2 ° C./min. Measured at the temperature rising rate of
It is shown by the value of δ. * 3: Due to the high viscosity, voids remained and good FRP could not be produced.

[0021]

As described above, according to the present invention, it is possible to improve the adhesiveness of the vinyl ester resin composition without lowering the heat resistance.

Claims (1)

[Claims] 1. A rubber having a particle diameter of 1 μ or less is 1 to 30% by weight.
A curable resin composition having excellent adhesiveness and heat resistance, which is obtained by adding a radical generator to a mixture of a dispersed vinyl ester resin and a polymerizable monomer.