JPH0770406A - Low temperature curing epoxy resin for prepreg and prepreg using the same - Google Patents

Abstract

PURPOSE:To provide the composition comprising a bifunctional epoxy resin, a multifunctional epoxy resin, a low temperature curing agent having a specific reaction-starting temperature, and an acrylic rubber in a specified ratio, high in the interfacial adhesive strength to reinforcing fibers and in the adhesive strength to other materials, and useful for prepregs, etc. CONSTITUTION:(A) 100 pts.wt. of epoxy resins comprising 50-95 pts.wt. of a bifunctional epoxy resin (e.g., a bisphenol A type epoxy resin and a higher functional epoxy resin (e.g., a phenol novolak epoxy resin), (B) a low temperature curing agent (e.g. an amine compound-epoxy resin-urea reaction product) exhibiting latent curability at the ordinary temperature and having a reaction- starting temperature of 40-115 deg.C in an amount of 0.2-3 times equivalent per equivalent of the component A, and (C) 1-20 pts.-wt. of an acrylic rubber (e.g. a crosslinked acrylic rubber) to obtain a resin composition enhanced in the interfacial adhesive strength to reinforcing fibers and in the adhesive strength to other materials in FRP moldings.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is a molding which is excellent in storage stability of resin and also excellent in interfacial adhesion strength between reinforcing fiber (particularly glass fiber) and resin phase and adhesion strength between resin phase and other members. The present invention relates to an epoxy resin composition for low-temperature-curable prepreg that gives a body, and a prepreg using the same.

[0002]

2. Description of the Related Art Epoxy resin is the heat resistance of the cured product,
It is excellent in elastic modulus, hardness, chemical resistance and the like, and is widely used as a resin composition for prepreg, in which reinforced fibers such as aramid fiber, glass fiber and carbon fiber are particularly used. Such prepregs are widely used in various technical fields, and are particularly often used in the production of golf club shafts, fishing rods, tennis racket frames, skis, etc. because of their light weight and high mechanical strength. There is.

Conventionally, prepregs are manufactured according to their manufacturing method.
Solvent type that uses a low viscosity impregnating liquid using a solvent as a resin composition for prepreg, without using a solvent,
There are a hot-melt type that uses a high-viscosity type that fluidizes at a certain temperature, and a room-temperature-impregnated type that uses a low-viscosity resin that is fluid at room temperature without using a solvent.

Solvent-type prepregs are used for molding the above-mentioned respective sports members. However, since the solvent-type prepregs use a solvent, the storage stability and handleability of the prepregs deteriorate due to the progress of the reaction. There are problems such as variations in the physical properties and surface finish of FRP molded products, and a bad working environment. Further, since the room temperature impregnated type has a low initial viscosity and cannot be impregnated into a uniform thickness, it has poor surface property and handleability, and it is necessary to increase the viscosity from a low viscosity of about 1000 cps to a high viscosity of about 100,000 cps. However, there is a drawback that the control of the reaction is difficult and the physical properties of the obtained prepreg vary due to the large increase in viscosity.

On the other hand, the hot-melt type has advantages such as good storage stability, easy control of handleability of the prepreg, and production of a clean prepreg free from a solvent. This has the advantages of significantly improving production efficiency and enabling low-temperature integral molding with core materials with low heat resistance.

In the current sports field, for example, golf heads, shafts, arm portions of various rackets, and various boards and the like are integrally molded by using prepregs. Low sex (1
Since it is mainly formed integrally with the core material (00 ° C. or less), a low temperature curing type prepreg that can be cured and molded at a lower temperature in a shorter time is eagerly desired.

More specifically, in the conventional hot-melt type prepreg, high temperature (120 to 130 ° C.) and long time (1 to 2 hours) are required for curing. Therefore, low temperature rapid curing significantly increases production efficiency and heat resistance. Low temperature co-molding with low core materials is still impossible. This limits the application of the prepreg and makes the manufacturing process inefficient.

On the other hand, in the case of using a hot melt type low temperature curing prepreg, the present inventors have made various proposals (for example, Japanese Patent Application No. 4-325518 and Japanese Patent Application Laid-Open No. 5-9263). Etc.) can be cured at a low temperature (70 to 100 ° C.) and a short time (about 20 minutes to 1 hour) while maintaining storage stability, so that the production efficiency is greatly improved and the core material has low heat resistance. It becomes possible to perform low-temperature integral molding. Further, the rapid curing significantly improves the surface properties of the cured molded product. However, when the conventional low temperature curing type prepreg is used, although the low temperature rapid curing performance of the resin is excellent, the chemical or physical bond between the reinforcing fiber and the resin is not sufficient due to the low curing temperature, and both There is a problem in that the interfacial adhesive strength is not sufficiently expressed as compared with the case of a general prepreg. Further, since the adhesive strength between the cured resin and other members, such as aluminum plate, wood, and GFRP, is low, it is possible to perform low-temperature integral molding with these members, but the prepreg cured phase and other There is also a problem that peeling and destruction with the member occur, and the performance of the final product is not sufficiently expressed. In order to compensate for this, the present situation is that another interface is used to form the prepreg using another adhesive. Therefore, this problem is a serious problem that must be solved immediately in order to manufacture a high-performance product by efficient low temperature integral molding.

[0009]

SUMMARY OF THE INVENTION Therefore, the present invention has been made in view of the above circumstances of the prior art, and it is the storage stability of the resin, the impregnation property of the resin into the reinforcing fiber at the time of prepreg production, and the handling of the prepreg. The adhesive strength between the cured resin phase and the reinforcing fiber in the resulting FRP, and particularly the adhesive strength between the cured resin phase and other members such as an aluminum plate, is significantly improved without impairing the bending resistance and the bending property of the FRP. It is an object of the present invention to provide an epoxy resin composition for low temperature curing type prepreg and a prepreg using the same.

[0010]

According to the present invention, 100 parts by weight of an epoxy resin (A) comprising 50 to 95 parts by weight of a bifunctional epoxy resin and 5 to 50 parts by weight of a polyfunctional epoxy resin having a functionality of 2 or more. , The latent reaction is exhibited at room temperature with respect to 1 equivalent of the epoxy resin (A), and the reaction initiation temperature is 40 to 115 ° C.
A low-temperature curing type prepreg epoxy resin composition comprising 0.2 to 3 times equivalents of a low-temperature curing agent (B) and 1 to 20 parts by weight of an acrylic rubber (C) is provided, and on a sheet. The matrix resin composition has a viscosity of 1 at 50 ° C., which is obtained by coating the epoxy resin composition for low temperature curing type prepreg and heating the mixture at 50 to 70 ° C. while narrowing the reinforcing material from one side or both sides and impregnating it. ，
There is provided an epoxy resin prepreg characterized in that it is 000 to 1,000,000 cps.

That is, in the epoxy resin composition for prepreg of the present invention, 95 to 50 parts by weight of a bifunctional epoxy resin and 5 to 50 parts by weight of a polyfunctional epoxy resin having a functionality of two or more (both 100 parts by weight in total) are used as a main component. Using the epoxy resin 1
Since the low temperature curing agent is added in an amount of 0.2 to 3 times equivalent and the acrylic rubber is added in an amount of 1 to 20 parts by weight with respect to 00 parts by weight, the matrix resin composition of the prepreg using the composition. Has a viscosity of 1,000-
Since it is assumed to be 1,000,000 cps,
Reinforcing fiber (mainly glass fiber) in FRP cured product without impairing storage stability of resin, resin impregnation property into reinforcing fiber at the time of prepreg production, prepreg handling property, reaction rate and bending physical properties of FRP The interfacial adhesion strength with the resin phase and the adhesion strength between the resin phase and other members can be significantly improved. The above resin not only develops the physical properties of FRP by adhering / curing with the reinforcing fiber in the prepreg, but also can be used as an adhesive with other adjacent members. Therefore, it is possible to use a prepreg using the same resin system. In this way, adhesive-free, efficient low-temperature integral molding becomes possible. Further, since the toughness (flexibility) of the resin is improved, the impact resistance is also expected to be improved.

The present invention will be described in more detail below. Epoxy resin (A) used in the epoxy resin composition of the present invention
Is composed of 95 to 50 parts of a bifunctional epoxy resin and 5 to 50 parts of a polyfunctional epoxy resin having a functionality of 2 or more, and 100 parts by weight in total. Bifunctional epoxy resins include bisA type (diglycidyl ether, diglycidyl ester type, etc.) marketed by Yuka Shell Co., Sumitomo Chemical Co., Ltd., Asahi Kasei Co., Ltd., Dainippon Ink Co., Ltd., etc. There is a resin. Specific examples of these bifunctional epoxy resins include:
The following are listed. Yuka Shell Co., Ltd .: Epicoat 801, 802, 80
7, 815, 819, 828, 834, 1001, 10
02, 1003, 1004, etc., Dainippon Ink Co., Ltd .: Epicron 840, 850, 85
5, 860, 900, 830, etc. Sumitomo Chemical Co., Ltd .: ELA115, 127, 128, 13
4th grade, Asahi Kasei Corporation: AER330, 331, 354, 33
7, 661, 662, etc., Nippon Kayaku Co., Ltd .: RE-403S, -404S, -41.
0S, -310S, -304S, etc.

The polyfunctional epoxy resins include orthocresol novolac type, phenol novolac type, which are commercially available such as Yuka Shell Co., Sumitomo Chemical Co., Asahi Kasei Co., Ltd., Dainippon Ink Co., Ltd. There are glycidylamine-based and other bifunctional or higher-functional resins. The epoxy equivalent of novolac type is 170 to 250, and the epoxy equivalent of glycidylamine is 90 to 150. Specific examples of these polyfunctional epoxy resins include the following. Phenol novolac type: Yuka Shell Co., Ltd .: Epicoat 152 (2.2 functional),
Epicoat 154 (3.5 functional +), Dainippon Ink Co., Ltd .: Epicron N730 (2.5 functional), Epicron N740 (3.6 functional), Epiclon N738-740 (3.5-4.5 functional), Nippon Kayaku Co., Ltd .: EPPN201, RE300, etc. Cresol novolac type: Yuka Shell Co., Ltd .: Epicoat 180 series, Asahi Kasei Corporation: A. R. E273, 280, 299, Sumitomo Chemical Co., Ltd .: ESCN-195X, 220, Dainippon Ink Co., Ltd .: Epicron N-665, 670,
673, 680, 690, 695, Nippon Kayaku Co., Ltd .: ECON-100, 102S, 103
S, 104S, etc. Glycidylamine type: Yuka Shell Co., Ltd .: Epikote 604 [tetraglycidyldiaminodiphenylmethane (TGDDM)], Sumitomo Chemical Co., Ltd .: ELM-100 (trifunctional), ELM-
120 (3-functional), ELM-434 (4-functional), Dainippon Ink Co., Ltd .: Epiclon 421L (3-functional),
430 (tetrafunctional). Other glycidyl amine type: triglycidyl-p-aminophenol (trifunctional) [Chipa Geigy Co., Ltd., Toto Kasei Co., Ltd.] tetraglycidyl-m-xylylenediamine (tetrafunctional)
[Mitsubishi Gas Chemical Co., Ltd.] Triglycidyl-metaaminophenol (trifunctional) [Sumitomo Chemical Co., Ltd.].

These polyfunctional epoxy resins are added in an amount of 5 to 50 parts by weight based on 100 parts by weight of the epoxy resin.
Addition of 0 to 30 parts by weight is preferred. This addition improves the interfacial adhesion strength between the resin and the glass fiber. It is presumed that the reason is that by increasing the number of intramolecular functional groups, the probability of coupling between the resin phase and the glass surface oxygen functional groups increases. From this, the interfacial adhesiveness between the conventional low temperature curable resin and the reinforcing fiber is improved. If the amount added is less than 5 parts by weight based on 100 parts by weight of the total epoxy resin, no effect is exhibited. On the other hand, if the amount added exceeds 50 parts by weight, the reaction rate of the resin composition tends to decrease, and bending properties, interface strength and Tg decrease due to insufficient curing. (If added excessively, the reaction rate tends to be slow due to crowding of glycidyl groups (steric hindrance), and full cure cannot be performed at a low temperature of 70 to 100 ° C.)

It has a latent property at room temperature and a reaction initiation temperature of 40.
As the low temperature curing agent (B) having a temperature of up to 115 ° C., for example,
A curing agent compound obtained by heating and reacting an amine compound, an epoxy resin, and urea described in JP-A-3-177418.
Examples thereof include a curing agent obtained by microencapsulating an amine compound described in JP-A-64-70523. The use ratio of the low temperature curing agent (B) is 0.2 to 3 times equivalent to 1 equivalent of the epoxy resin (A). If it is less than 0.2 times equivalent or more than 3 times equivalent, curing is insufficient and the resulting prepreg exhibits insufficient characteristics.

The reaction initiation temperature referred to in the present invention is D
The temperature is raised at a temperature rising rate of 10 ° C./mm by using SC, and the on se obtained from the exothermic curve as shown in FIG. 1, for example.
t means temperature.

The epoxy resin composition of the present invention also comprises
Acrylic rubber is compounded, and examples of the rubber include crosslinked acrylic rubber, crosslinked NBR, and carboxy-terminal NBR.
(CTBN) or the like is used. In addition, as the CTBN, an epoxy pre-modified CT previously bonded with an epoxy resin is used.
BN can also be used. Commercially available products of these acrylic rubbers include crosslinked acrylic rubbers having an average particle size of 3,
CX-MN series manufactured by Nippon Shokubai Co., Ltd. of 000Å is XER-91 manufactured by Nippon Synthetic Rubber Co., Ltd. having an average particle size of 700 to 800Å as a crosslinked NBR, and BF as CTBN.
Goodrich Hycar CTBN 1300 manufactured by Goodrich
X8, 1300x13 and MF61 manufactured by Japan Synthetic Rubber Co., Ltd.
1A, MF620A, etc., with an average particle size of 500 to 50,
It is preferably about 000Å.

As described above, the acrylic rubber used in the present invention is uniformly compatible with the crosslinked acrylic rubber which is not compatible with the epoxy resin and is present in the resin as a dispersed phase in the epoxy resin when mixed. However, there is a CTBN type in which a rubber phase is precipitated as a rubber-rich phase upon curing, and both are effective in improving the interfacial adhesion strength with reinforcing fibers and the adhesion strength with other members. In any case, acrylic rubber (C)
Is 1 to 20 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of the epoxy resin (A). 1
If it is less than 20 parts by weight, the effect of improving the adhesive strength is small, and if it exceeds 20 parts by weight, the FRP bending properties and Tg are remarkably lowered. The addition of these acrylic rubber components has little effect on the storage stability, handleability and curing rate of the resin composition within the above range.

The acrylic rubber used in the present invention has a Tg of
Is −30 to −40 ° C., average particle size is 500 to 50,000
The crosslinked acrylic rubber (the above-mentioned rubber dispersion system), which is a fine particle rubber within the range of Å and has no melting point, suppresses the decrease in FRP bending physical properties and Tg, and also the cured resin phase, glass fiber and other members. Is most preferable for improving the adhesive strength with. Further, in these rubbers, an acidic group such as a carboxyl group is often present at the molecular end, but the functional group reduces the reaction rate by masking the amine. Therefore, it is desirable to eliminate the same functional group by reacting with an epoxy resin or the like in advance. In the CTBN type, which is a liquid type rubber, the resin structure is chained and the network density is reduced to impart flexibility to the cured resin and increase the adhesive strength.

In the present invention, a silane coupling agent may be added in order to further improve the adhesiveness between the resin phase and the reinforcing fibers or other members. In this case, the silane coupling agent is one having an epoxy group or an amino group capable of binding to the organic phase at the terminal and an alkoxysilane such as methoxysilane or ethoxysilane easily coupling at the other end. preferable. Further, the addition amount of the silane coupling agent is generally 10
About 0.3 to 3.0 parts by weight is suitable for 0 parts by weight.

In the present invention, examples of the sheet (support) coated with the epoxy resin composition include release paper, release film, metal foil and the like. The release paper is preferably used because it has releasability and has heat resistance and strength that can withstand the temperature and tension in the prepreg manufacturing process.

The reinforcing fibers used in the prepreg of the present invention include, for example, glass fibers, carbon fibers, mica, asbestos, synthetic resin fibers, or woven or non-woven fabrics thereof. The strength improving effect is remarkable. These reinforcing fibers are used in a fiber content of 20 to 70% with respect to the epoxy resin composition.

Furthermore, in the epoxy resin composition for prepreg of the present invention, various additives such as a filler, a coloring agent and a diluent may be blended within a range in which various properties are not lost.

In order to produce the prepreg of the present invention, for example, first, a sheet is coated with the matrix resin composition for prepreg comprising the above-mentioned epoxy resin to produce a resin-coated sheet. Next, the two resin-coated sheets are made to face each other with the resin-coated surface facing each other, a reinforcing material is sandwiched therebetween, and a hot press roller or the like is heated to room temperature to 70 ° C. under pressure and impregnated, and then the sheets are impregnated. The desired prepreg can be obtained by removing.

The viscosity of the obtained prepreg matrix resin composition at 50 ° C. is 1,000 to 1,000,
000 cps, preferably 50,000 to 300,000
It is 0 cps. Even if it is lower than 1,000 cps,
Even if it is higher than, 000,000 cps, the handling property of the prepreg is remarkably poor.

In the epoxy resin composition of the present invention,
Both of the polyfunctional epoxy resin and the acrylic rubber contribute to the improvement of the interfacial adhesion strength with the reinforcing fiber, and when they are used together within the range of the above-mentioned addition amount (in some cases, the silane coupling agent is also used), the interfacial adhesion Strength is greatly improved. Further, when the interfacial adhesion strength is low, the FRP breaks in a so-called interlaminar failure mode in which breakage occurs at the interface between the resin and the reinforcing fiber at the time of bending failure. And compression) to cause damage (no bending between layers when bending stress is applied). In addition, the addition of acrylic rubber significantly improves the flexibility (toughness) of the cured resin, and the adhesive strength between the cured resin layer and other members is significantly improved. Therefore, the resin composition can be a low temperature curable resin that can be used as an "adhesive". As a result, if the same resin-based prepreg is used, it is possible to perform low-temperature integral molding of a composite that is firmly adhered to other members without using an adhesive.

[0027]

EXAMPLES Next, the present invention will be described in more detail by way of examples. All parts shown below are based on weight.

Example 1 <Production of prepreg (hot melt type)> On release paper,
Glass fiber coated with an epoxy resin composition for prepreg having the following composition at 50 ° C. and unidirectionally arranged glass fiber [Asahi Fiber Glass Co., Ltd., standard name E glass fiber] as glass fiber Lamination was carried out at a rate of 50% by weight at 60 ° C. to produce a prepreg.

<Resin Composition> Epicoat 828 60 parts [Glycidyl ether type epoxy resin manufactured by Yuka Shell Co., Ltd .: Bifunctional] Epicoat 1001 30 parts [Glycidyl ether type epoxy resin manufactured by Yuka Shell Co., Ltd .: Bifunctional ] Epicoat 154 10 parts [Phenol novolac type epoxy resin manufactured by Yuka Shell Co., Ltd .: 3.5 functional +] FXE1000 20 parts (1 times equivalent) [Low temperature curing agent manufactured by Fuji Kasei Co., Ltd., reaction initiation temperature 92 C; see FIG. 1] Crosslinked NBR 2 parts [XER-91 manufactured by Nippon Synthetic Rubber Co., Ltd., average particle size 700 to 800Å, Tg: -35 ° C] DDM 2 parts (reactive thickener, diaminodiphenylmethane) resin Viscosity of the composition at 50 ° C. Immediately after production: 24,400 cps After one week: 178,000 cps

<Storage Stability and Handleability> The storage stability and handleability of the obtained prepreg were evaluated by leaving it at room temperature after manufacturing the prepreg. The results are shown in Table 1 below.

[0031]

[Table 1] Note) ○: Good tackiness △: Not very good tackiness ×… Poor tackiness

<Curing characteristics> The reaction rate in curing of the obtained prepreg was measured using a differential scanning calorimeter DSC-7 manufactured by Perkin Elmer.

<Measurement of physical properties> The obtained prepreg was made to have a thickness of 2
It was cut and laminated so as to have a thickness of 10 mm, and cured and molded at 90 ° C. for 20 minutes using a hot press machine. The compounding ratios of the resin composition are shown in Tables 2 and 3, and the bending properties of the obtained molded product are shown in Table 4. In addition, these measuring methods are as follows. Bending strength and elastic modulus (according to ASTM D790-80) Specimen size: 2 × 12.7 × 120 mm Jig radius: Indenter 3.2 mm Branch 3.2 mm Distance between fulcrums: 32 mm (16 mm for specimen thickness 2.0 mm
Test speed: 3.0 mm / min ILSS * (according to ASTM D2344) Specimen size: 2 × 6 × 12 mm Jig radius: Indenter 5 mm Branch 2 mm Test speed: 2 mm / min * Same measured value as reinforced fiber It represents the interfacial adhesion strength with the cured resin phase.

Further, in order to investigate the adhesive performance of the resin composition, according to JIS 6850, an aluminum plate (thickness = 1.6) subjected to a sandblast treatment and an aluminum plate having a thermoplastic resin adhered on its upper surface, commonly known as "Titanal" (Used in actual ski molding: thickness = 0.8 mm) was used to measure the tensile shear adhesive strength of the resin. Furthermore, JIS
According to 6854, a sandblasted aluminum thin plate (thickness = 0.2 mm) was cured and adhered with a resin, and the T-type peel strength between the resin and the aluminum thin plate was obtained using this. The results are shown in Table 5.

Examples 2 to 3 In Example 1, the blending amount of the crosslinked NBR was 5 parts and 10 parts.
The epoxy resin composition for prepreg was prepared in the same manner as in Example 1 except that the parts were used, and the prepreg and the molded body were manufactured and evaluated using the epoxy resin composition.

Examples 4 to 5 In Example 1, the compounding amount of the crosslinked NBR was 10 parts,
Furthermore, a silane coupling agent A187 [γ-glycidoxypropyl trimethoxysilane, Nippon Unicar Co., Ltd.
[Production] was added to prepare an epoxy resin composition for prepreg in the same manner as in Example 1 except that 1.0 part and 2.0 parts were added, and prepreg and a molded product were produced using the same. ,evaluated.

Example 6 An epoxy resin composition for prepreg was prepared in the same manner as in Example 1 except that the compounding amount of the crosslinked NBR was 20 parts, and the prepreg was produced using the same. Also, a molded product was manufactured and evaluated.

Examples 7 to 8 In Example 1, CTBN was replaced with 10 instead of the crosslinked NBR.
The epoxy resin composition for prepreg was prepared in the same manner as in Example 1 except that 20 parts and 20 parts of the prepreg were mixed, and the prepreg and the molded product were manufactured and evaluated using the epoxy resin composition.

Examples 9-10 In Example 3, polyfunctional epoxy resin Epicoat 15
An epoxy resin composition for prepreg was prepared in the same manner as in Example 3 except that the compounding amount of 4 was 30 parts and 50 parts and the compounding amount of the bifunctional epoxy resin Epicoat 828 was 40 parts and 20 parts. Then, the prepreg and the molded product were manufactured and evaluated using them.

Examples 11 to 13 In Example 1, polyfunctional epoxy resin Epicor and 15 were used.
The compounding amount of 4 is 10, 30 and 50 parts, the compounding amount of the bifunctional epoxy resin Epicoat 828 is 30 parts, 10 parts and 10 parts, and the compounding amount of the same Epicoat 1001 is 60 parts.
Parts, 60 parts and 40 parts, and the low temperature curing agent is HX37
22 [Asahi Kasei Co., Ltd., reaction start temperature 112 ° C.] Changed to 30 parts (1 equivalent), and the amount of crosslinked NBR compounded was 10
The epoxy resin composition for prepreg was prepared in the same manner as in Example 1 except that DDM was not added, and the prepreg and the molded body were manufactured and evaluated using the epoxy resin composition.

Examples 14 to 15 In Examples 3 and 9, the polyfunctional epoxy resin Epicoat 154 was changed to Epicoat 152 (phenol novolac type, 2.2 functional), and the compounding amount was 10 parts and 30 parts. Except for the above, an epoxy resin composition for prepreg was prepared in the same manner as in Examples 3 and 9,
Using it, a prepreg and a molded body were manufactured and evaluated.

Example 16 In Example 9, polyfunctional epoxy resin Epicoat 15
4 is Epicoat 604 (glycidylamine type, tetrafunctional)
The epoxy resin composition for prepreg was prepared in the same manner as in Example 9 except that the amount of the prepreg was changed to 30 parts and the prepreg and the molded product were manufactured and evaluated.

Comparative Example 1 Polyfunctional epoxy resin Epicoat 15 in Example 1
4 and the crosslinked NBR were not used, and the amount of Epicoat 828 used was 70 parts, in the same manner as in Example 1
An epoxy resin composition for prepreg was prepared, and a prepreg and a molded body were manufactured and evaluated using the composition. The compounding ratios of the resin composition are shown in Tables 6 and 7, the bending properties of the obtained molded product are shown in Table 8, and the tensile shear adhesive strength and T-type peel strength of the resin are shown in Table 9.

Comparative Example 2 An epoxy resin composition for prepreg was prepared in the same manner as in Example 1 except that the crosslinked NBR was not used, and the prepreg was produced and molded by using the same. Was manufactured and evaluated.

Comparative Examples 3 to 4 In Example 1, polyfunctional epoxy resin Epicoat 15
The compounding amount of 4 is 30 parts and 50 parts, the compounding amount of the bifunctional epoxy resin Epicoat 828 is 40 parts and 20 parts,
And Example 1 except that no cross-linked NBR was added.
In the same manner as above, an epoxy resin composition for prepreg was prepared, and a prepreg and a molded body were manufactured and evaluated using the composition.

Comparative Examples 5 to 6 An epoxy resin composition for prepreg was prepared in the same manner as in Example 1 except that the amounts of the crosslinked NBR compounded were 0.5 parts and 30 parts. Then, the prepreg and the molded product were manufactured and evaluated using them.

Comparative Examples 7 to 8 In Example 7, the compounding amount of CTBN was 0.5 parts and 3 parts.
An epoxy resin composition for prepreg was prepared in the same manner as in Example 7 except that the amount was 0 part, and the prepreg and the molded body were manufactured and evaluated using the epoxy resin composition.

Comparative Examples 9 to 11 In Example 11, the cross-linking NBR content was 0 part, 0.
An epoxy resin composition for prepreg was prepared in the same manner as in Example 11 except that 5 parts and 30 parts were used, and the prepreg and the molded body were manufactured using the epoxy resin composition.
evaluated.

Comparative Example 12 In Example 1, Epicoat 828 (70 parts) which is a bifunctional epoxy resin as the epoxy resin and Epicoat 1 were used.
Example 1 except that only 001 (30 parts) was used
In the same manner as above, an epoxy resin composition for prepreg was prepared, and a prepreg and a molded body were manufactured and evaluated using the composition.

Comparative Example 13 An epoxy resin composition for prepreg was prepared in the same manner as in Example 1 except that only Epicoat 154 (100 parts) which was a polyfunctional epoxy resin was used as the epoxy resin. Then, the prepreg and the molded body were manufactured using the same and evaluated.

Comparative Example 14 Araldite (manufactured by Ciba-Geigy) AW136H, which is currently used as an adhesive in the molding of skis.
(Main agent) and HY994 (curing agent) were mixed at 100: 40 parts, and using this resin system, GFRP was produced under curing conditions of 100 ° C. for 20 minutes to measure bending properties. In addition, the adhesive strength with an aluminum plate using the same resin system was also measured. The resin system was very unstable because the reaction proceeded from room temperature and could not be made into prepreg.

[0052]

[Table 2]

[0053]

[Table 3]

[0054]

[Table 4]

[0055]

[Table 5] Note 1) Aluminum plate: Sandblasted thickness 1.
6mm aluminum plate. 2) Titanal: A 0.8 mm thick aluminum plate having a thermoplastic resin adhered to the surface layer. The indication of + in the strength value is the case where aluminum is broken, that is, so-called member destruction, and therefore the adhesive strength of the resin is considered to be above these values. 3) Aluminum thin plate: Sandblasted to a thickness of 0.
2mm thin aluminum plate.

[0056]

[Table 6]

[0057]

[Table 7]

[0058]

[Table 8]

[0059]

[Table 9] Note 1) Aluminum plate: Sandblasted thickness 1.
6mm aluminum plate. 2) Titanal: A 0.8 mm thick aluminum plate having a thermoplastic resin adhered to the surface layer. The indication of + in the strength value is the case where aluminum is broken, that is, so-called member destruction, and therefore the adhesive strength of the resin is considered to be above these values. 3) Aluminum thin plate: Sandblasted to a thickness of 0.
2mm thin aluminum plate.

[0060]

The epoxy resin composition for prepreg of the present invention comprises 100 parts by weight of an epoxy resin (A) comprising 50 to 95 parts by weight of a bifunctional epoxy resin and 5 to 50 parts by weight of a polyfunctional epoxy resin having two or more functional groups. And 0.2 to 3 times equivalents of the low-temperature curing agent (B) which has latentity at room temperature and has a reaction initiation temperature of 40 to 115 ° C. and acrylic rubber (C) 1 to 20 relative to 1 equivalent of the epoxy resin (A). In addition, since the prepreg using the composition has a matrix resin composition having a viscosity at 50 ° C. of 1,
Since it is set to 000 to 1,000,000 cps, the reinforcing fiber in the FRP molded body (mainly, the storage stability of the resin, the impregnating property, the handling property, the reaction rate, the bending properties of the FRP, etc. are not impaired). It significantly improves the interfacial adhesion strength between the glass fiber) and the resin phase and the adhesion strength between the resin phase and other members. In addition, this resin is
Not only can the physical properties of FRP be exhibited by adhesion / curing with the reinforcing fiber, but it can also be used as another adjacent member, so using a prepreg using the same resin system will result in efficient adhesive-free use. It is possible to perform low temperature integral molding. Further, since the toughness (flexibility) of the resin is improved, the impact resistance is also expected to be improved.

[Brief description of drawings]

FIG. 1 is a low temperature curing agent FXE-1000 used in Example 7.
It is a graph which calculates the reaction start temperature of [Fuji Kasei].

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Hino 1-3-1 Nishitsurugaoka, Oi-cho, Iruma-gun, Saitama Tonen Research Institute

Claims (2)

[Claims] 1. 100 parts by weight of an epoxy resin (A) comprising 50 to 95 parts by weight of a bifunctional epoxy resin and 5 to 50 parts by weight of a polyfunctional epoxy resin having a functionality of 2 or more, and 1 equivalent of the epoxy resin (A). On the other hand, a low temperature curing agent (B) having a latent property at room temperature and a reaction initiation temperature of 40 to 115 ° C.
An epoxy resin composition for low temperature-curable prepreg, which comprises 3 equivalents and 1 to 20 parts by weight of an acrylic rubber (C). 2. A sheet is coated with the epoxy resin composition for low temperature curable prepreg according to claim 1 and is heated and impregnated at 50 to 70 ° C. while sandwiching a reinforcing material from one side or both sides. Of the matrix resin composition at 50 ° C
An epoxy resin prepreg having a viscosity of 1,000 to 1,000,000 cps.