JPH08245752A - Epoxy resin composition - Google Patents

Abstract

PURPOSE: To obtain the subject composition, consisting essentially of specific two kinds of epoxy resins and a curing agent. having a low viscosity and a long pot life at service temperatures. excellent in filament winding moldability and heat and moisture resistances after molding and useful as composite materials. CONSTITUTION: This resin composition consists essentially of (A) a bisphenol A type epoxy resin, (B) a polyglycidylamine type epoxy resin (e.g. a tetraglycidylamine type epoxy resin) and (C) 3,3'-diethyl-4,4'- diaminodiphenylmethane as a curing agent. Furthermore, the blending ratios of the respective components are preferably 60-150 pts.wt., more preferably 80-130 pts.wt. component (B) based on 100 pts.wt. component (A) and preferably 30-50 pts.wt., more preferably 35-45 pts.wt. component (C) based on 100 pts.wt. total amount of the component (A) and (B).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition for composite materials.

[0002]

2. Description of the Related Art Composite materials having carbon fiber, glass fiber, etc. as reinforcements are used for golf shafts, fishing rods, tennis rackets and other sports / leisure products, aircraft-related products, printing rolls,
It is used in industrial materials such as pressure vessels and in medical fields. Further, in recent years, such composite materials are often used for industrial material parts.

A fiber reinforced plastic (FRP) formed by impregnating a reinforcing fiber with a resin is generally formed by impregnating a reinforcing resin such as carbon fiber, glass fiber, alumina fiber, aramid fiber or boron fiber with a matrix resin and heat-molding. The composite material using the carbon fibers as the reinforcing fibers is called as carbon fiber reinforced plastic (CFRP).

The filament winding method, which is one of the typical molding methods, has high productivity and is excellent in FRP and CFRP.
Is a promising molding method. When molding CFRP, for example, by the filament winding method, the viscosity of the resin significantly affects the moldability. In order to uniformly impregnate the carbon fibers with the resin, a method of reducing the viscosity of the resin is usually used. When the viscosity of the resin is high, the fibers are not uniformly impregnated with the resin, and the pay-out property of the fibers is likely to deteriorate.

Further, there is a restriction that the pot life of the resin composition must be as long as at least 4 hours in order to mold a large-sized molded product, so that selection of the resin composition is an important issue.

Conventionally, an epoxy resin having excellent adhesiveness to carbon fibers has been used as a CFRP matrix resin. However, the glass transition temperature as CFRP is high, and the weight increase rate of water absorption at high temperature is 5.0.
% Or less heat and moisture resistant epoxy resin generally has a high viscosity and is difficult to use for filament winding molding. In particular, a resin composition obtained by mixing a polyfunctional glycidyl amine type epoxy resin and diaminodiphenyl sulfone or diaminodiphenylmethane as a curing agent has a high viscosity, and since the viscosity at the time of curing is extremely low, the resin may leak or flow. It cannot be used for filament winding molding because it causes a problem in accuracy of the molded product obtained. Further, since an acid anhydride is used as a curing agent in order to make the viscosity low, the moisture resistance of the obtained molded product is significantly reduced.

Several low-viscosity resin compositions capable of filament winding molding have been proposed so far, but they have the drawback of being inferior in either heat resistance or moisture resistance.

[0008]

In order to solve these problems, an object of the present invention is to make the resin composition have a low viscosity which enables filament winding molding, have a long pot life, and further mold these. In this case, an epoxy resin composition having excellent moldability, good quality of the obtained molded product, and excellent heat resistance and moisture resistance is provided.

[0009]

That is, the resin composition according to the present invention comprises (A) a bisphenol A type epoxy resin, (B) a polyglycidylamine type epoxy resin, and (C) 3,3'-diethyl- The present invention relates to an epoxy resin composition containing 4,4'-diaminodiphenylmethane as an essential component.

The blending ratio of (B) to 100 parts by weight of the component (A) used as the epoxy resin component in the present invention is preferably 60 to 150 parts by weight, more preferably 80 to 130 parts by weight.

When the amount of the component (B) is less than 60 parts by weight with respect to 100 parts by weight of the component (A), the glass transition temperature as CFRP is lowered and the heat resistance becomes insufficient, and when it exceeds 150 parts by weight, the epoxy resin component is used. Therefore, the viscosity becomes high, and it becomes impossible to sufficiently impregnate a fiber bundle such as carbon fiber.

The blending ratio of the component (C) used as a curing agent in the present invention is preferably 30 to 50 parts by weight based on 100 parts by weight of the total weight of the components (A) and (B), It is more preferably 35 to 45 parts by weight.

Total weight of component (A) and component (B) 10
When the amount of the component (C) is less than 30 parts by weight with respect to 0 parts by weight, the glass transition temperature as CFRP is lowered, heat resistance becomes insufficient, or moisture resistance is lowered. Further, if the amount of the component (C) is more than 60 parts by weight, the effect of improving heat resistance and moisture resistance commensurate with the increase in the amount cannot be obtained.

Examples of the bisphenol A type epoxy resin of the component (A) in the present invention include Epicoat 828, Epicoat 825 (trade name: above, Yuka Shell Epoxy Co., Ltd.), Epotote YD128 (trade name: Tohto Kasei ( Manufactured by Sumitomo Chemical Co., Ltd.), Epicron 850 (trade name: manufactured by Dainippon Ink and Chemicals, Inc.), Sumipoxy ELA-128 (trade name: manufactured by Sumitomo Chemical Co., Ltd.), and the like.

As the polyglycidyl amine type epoxy resin of the component (B), a triglycidyl amine type epoxy resin and a tetraglycidyl amine type epoxy resin can be used, and a tetraglycidyl amine type epoxy resin is particularly preferably used.

Specifically, as the triglycidylamine type epoxy resin, Sumiepoxy ELM120 and Sumiepoxy ELM100 (trade names: Sumitomo Chemical Co., Ltd.)
Manufactured by Dainippon Ink and Chemicals, Inc., and the like. Examples of the tetraglycidyl amine type epoxy resin include Epotote YH434 and Epotote YH434.
L (trade name: above, manufactured by Toto Kasei Co., Ltd.), Sumiepoxy ELM434, Sumiepoxy ELM434HV (trade name: above, Sumitomo Chemical Co., Ltd.), Araldite MY
-720 (trade name: manufactured by Asahi Chiba Co., Ltd.), Epicoat 60
4 (trade name: manufactured by Yuka Shell Epoxy Co., Ltd.) and the like.

Component (C) 3,3'-diethyl-4,
As 4'-diaminodiphenylmethane, those commercially available as Kayahard A-A, Kayahard A-B, Kayahard A-S (trade name: above, manufactured by Nippon Kayaku Co., Ltd.) and the like can be used.

In the epoxy resin composition of the present invention,
Other epoxy resins, toughness-imparting agents, fillers, colorants and the like can be appropriately added within a range that does not impair the performance. Bisphenol F is an epoxy resin that can be optionally contained in the epoxy resin composition of the present invention.
Type epoxy resin, o-cresol novolac type epoxy resin, cycloaliphatic epoxy resin, triglycidyl methane type epoxy resin, halogenated bisphenol A type epoxy resin and the like.

As the toughness-imparting agent, a reactive elastomer,
Hiker CTBN modified epoxy resin, urethane modified epoxy resin, nitrile rubber added epoxy resin, crosslinked acrylic rubber fine particle added epoxy resin, silicone modified epoxy resin, thermoplastic elastomer added epoxy resin, and the like. It can also be added to the toughness imparting agent.

Examples of the filler include mica, alumina, talc, fine powder silica, zinc dust, aluminum powder and the like. Examples of the colorant include organic pigments such as azo pigments, phthalocyanine pigments, quinacridone pigments, and anthraquinone pigments, and inorganic pigments such as titanium disulfide, chromium sulfide, cobalt blue, and iron sulfide.

In addition to the curing agent as the component (C), other curing agents and / or curing accelerators may be added, if necessary. Examples of these curing agents include diaminodiphenyl sulfone, diaminodiethyltoluene, triaminodiethyltoluene, dicyandiamide, phenol compounds such as phenol novolac resin, amine adduct type curing agents, and microcapsule type curing agents. However, even if these curing agents are used alone, a resin composition having a predetermined viscosity and heat resistance may not be obtained, which is not preferable.

As the curing accelerator, a BF ₃ complex such as a monomethylamine complex of boron trifluoride, 3- (3,4-dichlorophenyl) -1,1-dimethylurea, 3- (4-).
Examples thereof include chlorophenyl) -1,1-dimethylurea.

The method for producing the epoxy resin composition according to the present invention is not particularly limited, but the components (A) to (C) are usually added to 1
It is desirable to mix at 0 ° C to 80 ° C, preferably 20 ° C to 30 ° C. Mixing the curing agent (C) at a temperature higher than 80 ° C. is not preferable because the resin and the curing agent are likely to react with each other and the pot life of the resin composition tends to be shortened.

The use temperature of the resin composition is usually 10 to 80.
C., preferably 50 to 70.degree. C., and the pot life (pot life) at that temperature can be 5 hours or longer, preferably 8 hours or longer.

The moisture resistance of the resin composition is the rate of increase in weight of water absorption, that is, the weight increase when the composite material obtained by impregnating and molding the resin into the reinforcing fiber is left for 40 hours in steam at 150 ° C. The epoxy resin composition of the present invention is usually 5
It is possible to obtain those having a content of not more than wt%, preferably not more than 4 wt%, more preferably not more than 3 wt%.

In the epoxy resin composition of the present invention, the viscosity at 80 ° C. or lower, preferably 50 to 70 ° C. is 2 Pa · s or less, preferably 1 Pa · s or less, more preferably 0.7 Pa · s or less. Since it can be obtained, it is easily impregnated into the reinforcing fiber and is suitable for filament winding molding.

The heat resistance is determined by the glass transition point of the composition after curing, but the glass transition point of the epoxy resin composition of the present invention is usually 150 ° C. or higher, preferably 160 ° C. or higher, more preferably 170 ° C. or higher. A resin can be obtained.

Although the epoxy resin composition of the present invention is most suitable for filament winding molding, it can be effectively used for pull-through molding, hand lay-up molding and the like.

In the present invention, the above component (A),
A resin composition containing (B) and (C) is impregnated into a reinforcing fiber and molded by a filament winding method or the like to obtain a composite material.

The reinforcing fiber is not particularly limited, and all fibers used as the reinforcing fiber of the composite material can be used. For example, carbon fiber, glass fiber, aramid fiber, boron fiber, silicon carbide fiber, alumina fiber, potassium titanate fiber, polyethylene fiber and surface-treated organic fiber can be mentioned. Fibers having a hybrid structure of more than one type can be used. In particular, when carbon fiber is used as the reinforcing fiber, a lightweight and highly rigid molded product can be obtained, which is preferably used.

The epoxy resin composition of the present invention can be made into a composite material by a filament winding method. For example, a reinforcing fiber impregnated with a resin is wound around a mandrel by a filament winding method, and usually 15
A composite material can be obtained by heat-curing at 0 ° C. to 200 ° C. for 30 minutes to 2 hours. The obtained composite material has stable quality and has few voids.

Examples of the applications of these composite materials include printing ink rolls, bicycle pipes and pressure vessels. Above all, the above-mentioned composite material is suitable for a CFRP rubber-coated roll for printing ink. That is, in recent years, CFRP rubber-coated rolls have been rapidly used as a substitute for steel rolls because they are lighter in weight and have better workability than conventional steel rolls. Conventional 2
In the case of CFRP roll made of 50F cured epoxy resin, when unvulcanized rubber is wound around the CFRP pipe and vulcanized under steam heating at 150 ° C, the roll is deformed due to the influence of heat, or the influence of high temperature moisture Therefore, swelling or peeling may occur in part. On the other hand, since the CFRP roll obtained by the epoxy resin composition of the present invention has not only heat resistance at 150 ° C. but also less influence of steam, a rubber-coated roll for CFRP printing ink having excellent dimensional accuracy can be obtained. To be

[0033]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

Example 1 50 parts by weight of bisphenol A type epoxy resin (A) (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.), tetraglycidyl amine type epoxy resin (B) (trade name: Epotote YH- 434L (manufactured by Tohto Kasei Co., Ltd.)
50 parts by weight, 3,3'-diethyl-4,4'-diaminodiphenylmethane (C) (trade name: Kayahard AB,
40 parts by weight of Nippon Kayaku Co., Ltd. was added and thoroughly mixed with stirring at 25 ° C. to obtain the epoxy resin composition of the present invention. The glass transition points of this epoxy resin composition are 200 ° C. and 60 ° C.
The viscosity was 0.2 Pa · s, and the pot life at the same temperature was 8 hours or more, which was sufficiently long.

The resulting epoxy resin composition was heated to 60 ° C. to obtain a tensile elastic modulus of 230 GPa and a tensile strength of 3400 MP.
While impregnating the carbon fiber of a, by a filament winding method, it was wound around a mandrel having an inner diameter of 73 mmφ and cured at 180 ° C. for 2 hours to prepare a CFRP tube having a wall thickness of 3 mm. The thickness of this CFRP tube was uniform and had few voids. Furthermore, a CFRP tube was cut using a cutting machine to obtain a test piece having a length of 200 mm. This was left in steam at 150 ° C. for 40 hours. Weight increase is 2.5wt
%Met.

Example 2 40 parts by weight of bisphenol A type epoxy resin (A) (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.), tetraglycidyl amine type epoxy resin (B) (trade name: Epotote YH- 434L, manufactured by Tohto Kasei Co., Ltd.
60 parts by weight, 3,3'-diethyl-4,4'-diaminodiphenylmethane (C) (trade name: Kayahard AS,
50 parts by weight of Nippon Kayaku Co., Ltd. was added and thoroughly mixed with stirring at 25 ° C. to obtain the epoxy resin composition of the present invention. The glass transition points of this epoxy resin composition are 200 ° C. and 60 ° C.
The viscosity was about 0.6 Pa · s, and the pot life at the same temperature was 8 hours or more, which was sufficiently long.

The obtained epoxy resin composition was heated to 60 ° C. to obtain a tensile elastic modulus of 230 GPa and a tensile strength of 3400 MP.
While impregnating the carbon fiber of a, by a filament winding method, it was wound around a mandrel having an inner diameter of 73 mmφ and cured at 180 ° C. for 2 hours to prepare a CFRP tube having a wall thickness of 3 mm. The thickness of this CFRP tube was uniform and had few voids. Furthermore, a CFRP tube was cut using a cutting machine to obtain a test piece having a length of 200 mm. This was left in steam at 150 ° C. for 40 hours. Weight increase is 2.0wt
%Met.

Example 3 50 parts by weight of bisphenol A type epoxy resin (A) (trade name: Epotote YD-128, manufactured by Tohto Kasei Co., Ltd.),
Tetraglycidylamine type epoxy resin (B) (trade name: Epotote YH-434, manufactured by Tohto Kasei Co., Ltd.) 50
40 parts by weight of 3,3′-diethyl-4,4′-diaminodiphenylmethane (C) (trade name: Kayahard AA, manufactured by Nippon Kayaku Co., Ltd.) are added, and the mixture is sufficiently stirred and mixed at 25 ° C. Then, the epoxy resin composition of the present invention was obtained. The glass transition point of this epoxy resin composition was 200 ° C., the viscosity at 60 ° C. was about 0.4 Pa · s, and the pot life at the same temperature was 8 hours or more, which was sufficiently long.

The obtained epoxy resin composition was heated to 60 ° C. to obtain a tensile elastic modulus of 400 GPa and a tensile strength of 2300 MP.
While impregnating the carbon fiber of a, by a filament winding method, it was wound around a mandrel having an inner diameter of 73 mmφ and cured at 180 ° C. for 2 hours to prepare a CFRP tube having a wall thickness of 3 mm. The thickness of this CFRP tube was uniform and had few voids. Furthermore, a CFRP tube was cut using a cutting machine to obtain a test piece having a length of 200 mm. This was left in steam at 150 ° C. for 40 hours. Weight increase is 3.0wt
%Met.

Comparative Example 1 50 parts by weight of bisphenol A type epoxy resin (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.), tetraglycidyl amine type epoxy resin (trade name: Epotote YH-434L, Tohto Kasei Co., Ltd.) ) Made 50 parts by weight,
120 parts by weight of methyl hymic acid anhydride (manufactured by Hitachi Chemical Co., Ltd.) was added as a curing agent, and 2 parts as a curing accelerator.
2 parts by weight of -ethyl-4-methylimidazole are added,
The mixture was sufficiently stirred and mixed at 25 ° C to obtain an epoxy resin composition.

The resulting epoxy resin composition was heated to 60 ° C. to obtain a tensile elastic modulus of 230 GPa and a tensile strength of 3400 MP.
While impregnating the carbon fiber of a, by a filament winding method, it was wound around a mandrel having an inner diameter of 73 mmφ and cured at 180 ° C. for 2 hours to prepare a CFRP tube having a wall thickness of 3 mm. Use a cutting machine to cut the CFRP pipe to a length of 200
mm test pieces were obtained. 4 in steam at 150 ℃
It was left for 0 hours. The weight increase was 6.0 wt%. Also, swelling and peeling were observed on the surface.

Comparative Example 2 50 parts by weight of bisphenol A type epoxy resin (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.), tetraglycidylamine type epoxy resin (trade name: Epotote YH-434L, Tohto Kasei Co., Ltd.) ) Made 50 parts by weight,
30 parts by weight of diaminodiphenyl sulfone was added as a curing agent, 0.5 part by weight of a monomethylamine complex of boron trifluoride was added as a curing accelerator, and the mixture was sufficiently stirred and mixed at 25 ° C. to obtain an epoxy resin composition. It was The viscosity of this epoxy resin composition at 60 ° C. was 2.3 Pa · s.

The obtained epoxy resin composition was heated to 60 ° C. to obtain a tensile elastic modulus of 230 GPa and a tensile strength of 3400 MP.
The mandrel having an inner diameter of 73 mmφ was wound around the mandrel by the filament winding method while impregnating the carbon fiber of a, but the impregnation of the fiber was not uniform, and the unwinding property of the fiber was poor, and it could not be wound uniformly. In addition, 18
It was cured at 0 ° C. for 2 hours to prepare a CFRP tube having a wall thickness of 3 mm. However, in the obtained molded product, the resin leaked during curing, the wall thickness was not uniform, and there were many voids.

Comparative Example 3 100 parts by weight of bisphenol A type epoxy resin (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.)
30 parts by weight of 3,3′-diethyl-4,4′-diaminodiphenylmethane (C) (trade name: Kayahard AB, manufactured by Nippon Kayaku Co., Ltd.) were added, and the mixture was sufficiently stirred and mixed at 25 ° C. to prepare an epoxy resin. A resin composition was obtained.

The obtained epoxy resin composition was heated to 60 ° C. to obtain a tensile elastic modulus of 230 GPa and a tensile strength of 3400 MP.
While impregnating the carbon fiber of a, by a filament winding method, it was wound around a mandrel having an inner diameter of 73 mmφ and cured at 180 ° C. for 2 hours to prepare a CFRP tube having a wall thickness of 3 mm. The glass transition temperature of the obtained molded product is 130.
° C. When this was left in steam at 150 ° C. for 40 hours, the molded product was deformed.

Comparative Example 4 Bisphenol A type epoxy resin (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.) 50 parts by weight, tetraglycidyl amine type epoxy resin (trade name: YH-
434L, manufactured by Tohto Kasei Co., Ltd., 50 parts by weight, and 30 parts by weight of diaminodiphenylmethane as a curing agent were added.
The mixture was sufficiently stirred and mixed at 0 ° C. to obtain a resin-based epoxy resin composition. The viscosity of this epoxy resin composition at 60 ° C. is 3.0 Pa.
・ It was s.

The obtained epoxy resin composition was heated to 60 ° C. to obtain a tensile elastic modulus of 230 GPa and a tensile strength of 3400 MP.
The mandrel having an inner diameter of 73 mmφ was wound around the mandrel by the filament winding method while impregnating the carbon fiber of a, but the impregnation of the fiber was not uniform, and the unwinding property of the fiber was poor, and it could not be wound uniformly.

Comparative Example 5 100 parts by weight of bisphenol A type epoxy resin (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.) was used as a curing agent of N, N '-(4,4'-methylenebisphenyl). ) -Adding 30 parts by weight of dimethylamine,
The mixture was sufficiently stirred and mixed at 25 ° C to obtain an epoxy resin composition.

The obtained epoxy resin composition was heated to 60 ° C. to obtain a tensile elastic modulus of 230 GPa and a tensile strength of 3400 MP.
While impregnating the carbon fiber of a, by a filament winding method, it was wound around a mandrel having an inner diameter of 73 mmφ and cured at 180 ° C. for 2 hours to prepare a CFRP tube having a wall thickness of 3 mm. The glass transition temperature of the obtained molded product is 130.
° C. When this was left in steam at 150 ° C. for 40 hours, the molded product was deformed.

Comparative Example 6 30 parts by weight of bisphenol A type epoxy resin (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.), bisphenol A type epoxy resin (trade name: Epicoat 1)
001, manufactured by Yuka Shell Epoxy Co., Ltd., 30 parts by weight of N, N '-(4,4'-methylenebisphenyl) -dimethylamine was added as a curing agent to 70 parts by weight of 2 parts.
The mixture was sufficiently stirred and mixed at 5 ° C to obtain an epoxy resin composition. The 60 ° C. viscosity of this epoxy resin composition was 40 Pa · s.

The obtained epoxy resin composition was heated to 60 ° C. to obtain a tensile elastic modulus of 230 GPa and a tensile strength of 3400 MP.
The carbon fiber of a was impregnated, but the viscosity was high, and the fiber could not be impregnated.

[0052]

The epoxy resin composition of the present invention has a low viscosity and a long pot life at the operating temperature.
Particularly, it is suitable for filament winding molding and the like, and when it is used as a matrix of a composite material, a composite material having few voids and excellent in heat resistance and moisture resistance can be obtained.

Claims (1)

[Claims] 1. An epoxy containing (A) bisphenol A type epoxy resin, (B) polyglycidyl amine type epoxy resin, and (C) 3,3′-diethyl-4,4′-diaminodiphenylmethane as essential components. Resin composition.