JP2009242585A - Resin composition for composite material intermediate member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for a composite material intermediate member, with which a composite material excellent in both of heat resistance and toughness is obtained. <P>SOLUTION: The resin composition for a composite material intermediate member comprises (A)-(D) as essential ingredients, wherein: (A) is an oligomer obtained by making a bisphenol F type epoxy resin of 20-60 mol%, a p-aminophenol type epoxy resin of 20-50 mol%, and a phenol compound represented by chemical formula (I) of 20-50 mol%, preliminarily react with one another, of 15-60 pts.mass; (B) is an epoxy resin having a naphthol glycidyl ether structure represented by chemical formula (II) of 10-40 pts.mass; (C) is another two to four functional epoxy resin of 15-75 pts.mass; and (D) is diaminodiphenyl sulfone of 90-175% equivalent of a theoretical equivalent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resin composition for a composite material intermediate material that provides a composite material having excellent heat resistance and toughness. A composite material obtained from this composite material intermediate is used in aircraft, automobiles, general industries, and the like.

  Conventionally, epoxy resin has been widely used as a matrix resin for composite materials due to its adhesiveness and high rigidity. However, as the performance requirements for composite materials become higher year by year, it becomes difficult to satisfy all of the requirements. ing. That is, the main characteristics required for the composite material are heat resistance and toughness, but these two characteristics generally tend to conflict with each other, and it is extremely difficult to achieve both.

  For example, for applications requiring heat resistance, epoxy resin compositions containing N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane (TGDDM) as the main component and diaminodiphenylsulfone (DDS) as a curing agent are widely used. However, although this composition is excellent in heat resistance and rigidity, it is hardly applicable to applications requiring toughness because the resin has low toughness. In addition, when a bifunctional epoxy resin typified by a bisphenol A type epoxy resin is used as a main component in order to impart toughness, the heat resistance is lowered and the required performance is often not satisfied.

In order to solve these problems, various studies have been made on N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane (TGDDM) / amine curing agent system, but the resin composition has high toughness while maintaining heat resistance. Is not obtained (Patent Documents 1-3).
JP 60-28420 A JP-A-60-28421 JP 60-58419 A

  The inventors of the present invention have reached the present invention as a result of intensive studies to develop a composite material intermediate material that is excellent in both heat resistance and toughness, which was difficult in the prior art.

That is, this invention is the resin composition for composite material intermediate materials which have the following (A)-(D) as an essential component.

(A) 20-60 mol% of bisphenol F type epoxy resin, 20-50 mol% of p-aminophenol type epoxy resin, 20-50 mol% of phenol compound represented by chemical formula (I) is obtained by preliminary reaction. 15-60 parts by mass of oligomer

[Wherein X represents a hydrogen atom and / or a methyl group]
(B) 10 to 40 parts by mass of an epoxy resin having a naphthol glycidyl ether structure represented by the chemical formula (II)

(C) 15 to 75 parts by mass of other 2 to 4 functional epoxy resin (D) diaminodiphenyl sulfone ... 90 to 175% equivalent of theoretical equivalent And, as component (B), an epoxy resin represented by chemical formula (III), Alternatively, an epoxy resin represented by the chemical formula (IV) is preferably used.

The component (C) of the present invention needs to be appropriately selected according to the component (B) in order to balance the entire physical properties. When (B) is an epoxy resin represented by chemical formula (III), (C) is preferably N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane, and (B) is represented by chemical formula (IV). (C) is preferably N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane and bisphenol F type epoxy resin.

  This invention provides the resin composition for composite material intermediate materials which is excellent in toughness, maintaining high heat resistance. A composite material obtained from a composite material intermediate material using this is useful in aircraft, automobiles, general industries and the like.

  (A) component in this invention is 20-60 mol% bisphenol F type epoxy resin, 20-50 mol% p-aminophenol type epoxy resin, 20-50 mol% of phenolic compounds represented by the general formula (I) Is an oligomer obtained by reacting

  If the ratio of the bisphenol F type epoxy resin in the component (A) is less than 20 mol%, sufficient toughness cannot be obtained, and if it exceeds 60 mol%, the heat resistance of the final composition is lowered. A more preferable range is 30 to 40 mol%.

  If the ratio of the p-aminophenol type epoxy resin in the component (A) is less than 20 mol%, sufficient heat resistance cannot be obtained, and if it exceeds 50 mol%, gelation may occur during the preliminary reaction. . A more preferable range is 40 to 50 mol%.

  The bisphenol F type epoxy resin (a) in the present invention preferably has an epoxy equivalent of 156 to 180. When it exceeds 180, the crosslinking density of hardened | cured material will fall, and heat resistance and solvent resistance will fall significantly.

  The preliminary reaction of bisphenol F type epoxy resin, p-aminophenol type epoxy resin, and phenol compound can be easily carried out under heating and, if necessary, in the presence of a catalyst. The reaction conditions may be appropriately set such that the reaction proceeds relatively gently and 80% or more of the phenolic hydroxyl groups react. However, the oligomer after the reaction should contain substantially no phenolic hydroxyl groups. Is desirable. In general, when no catalyst is used, 5 to 24 hours are appropriate at 100 to 150 ° C, and when a catalyst is used, 2 to 6 hours are appropriate at 100 to 130 ° C. The catalyst used for the preliminary reaction is not particularly limited as long as it appropriately promotes the reaction between the epoxy group and the phenolic hydroxyl group, but triphenylphosphine is particularly preferable. What is necessary is just to set suitably the quantity of the catalyst to be used so that reaction may advance smoothly.

  As the component (B) of the present invention, an epoxy resin having a naphthol glycidyl ether structure represented by the chemical formula (II) is used. Of these, a bifunctional epoxy resin represented by the chemical formula (III) and a tetrafunctional epoxy resin represented by the chemical formula (IV) are preferably used. As the bifunctional epoxy resin represented by the chemical formula (III), HP4032 (manufactured by Dainippon Ink Chemical Co., Ltd., molecular weight 314) is used. As the tetrafunctional epoxy resin represented by the chemical formula (IV), HP4700 (manufactured by Dainippon Ink Chemical Co., Ltd., molecular weight). 648).

  The component (C) of the present invention needs to be appropriately selected according to the component (B) in order to balance the entire physical properties. That is, when (B) is an epoxy resin represented by the chemical formula (III), N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane is preferred. When (B) is an epoxy resin represented by the chemical formula (IV), it is preferable to use N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane and a bisphenol F type epoxy resin in combination.

  The ratio of the resin components (A), (B), and (C) in the present invention needs to satisfy the following ratio.

(A) Component 15-60 parts by mass (B) Component 10-40
(C) Component 15-75 〜
When the ratio of each component does not satisfy the above range, either the impact resistance or the mechanical properties in the high temperature moisture absorption state is lowered, and it becomes difficult to satisfy both.

A more preferred range is
(A) Component 20-50 parts by mass (B) Component 20-35%
(C) Component 20-60cm
It is.

A more preferred range is (A) component 43 to 47 parts by mass (B) component 23 to 27%.
(C) Component 23-38cm
It is.

  As the component (D) of the present invention, 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, or the like is used. 4,4'-diaminodiphenyl sulfone is particularly preferred.

  The amount of the component (D) used in the present invention is suitably 90 to 175% equivalent of the theoretical equivalent calculated from the following formula, and more preferably 100 to 150% equivalent. If the amount of (D) used is less than 90% equivalent, curing will be insufficient and satisfactory physical properties will not be obtained. Conversely, if it exceeds 175% equivalent, the crosslinking density will be greatly reduced, and heat resistance and solvent resistance will be greatly increased. To drop.

(D) Theoretical amount of component = [sum of moles of epoxy group used for precondensation of component (A)]-[number of moles of phenolic OH used for precondensation of component (A)] + [(B ) And the sum of the number of moles of epoxy groups in component (C)]
The epoxy resin composition of the present invention can be used in combination with other epoxy resins within a range that does not impair the overall physical property balance. Examples of other epoxy resins include novolac type epoxy resins. The amount of component (E) used is preferably 20% or less of the total resin components.

  The resin composition of the present invention has a thermoplastic resin component such as a so-called elastomer component such as a butadiene-acrylonitrile copolymer having both carboxyl groups at the ends, polyethersulfone, polysulfone, polyetheretherketone, polyetherimide, polyvinylbutyrate, etc. May be used in combination according to the purpose. What is necessary is just to set the usage-amount of these components suitably according to the objective within the range which does not destroy the whole physical property balance. Further, inorganic compounds such as silica powder, aerosil, microballoon, antimony trioxide and the like may be contained depending on the purpose.

The resin composition of the present invention is excellent as a matrix resin of a composite material, and a composite material having excellent physical properties such as heat resistance, water resistance and impact resistance can be obtained. Carbon fiber, glass fiber, aramid fiber, boron fiber, silicon carbide fiber, etc. are used as the reinforcing material of the composite material, and these can be used in the form of milled fiber, chopped fiber, continuous fiber, various fabrics, etc. However, a carbon fiber having a high strength and high elongation having a tensile strength of 450 MPa or more and a tensile elongation of 1.7% or more is most preferably used in the form of continuous fibers or various woven fabrics. The method for obtaining the composite material intermediate from the resin composition of the present invention and the reinforcing fiber is not particularly limited, and a commonly used method can be used as it is.

  The present invention will be specifically described below with reference to examples. The average molecular weight of the epoxy resin used for calculating the molar ratio in the examples was calculated from the following formula.

[Epoxy equivalent] x [Average number of functional groups per molecule]
Abbreviations of substance names in the examples are as follows.

jER807: Bisphenol F type epoxy resin (average molecular weight 335) manufactured by Japan Epoxy Resin Co., Ltd.
jER630: p-aminophenol type epoxy resin (average molecular weight 290) manufactured by Japan Epoxy Resin Co., Ltd.
BXP: Mitsui Chemicals 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bis (2,6-dimethylphenol) (molecular weight 403)
HP4032: Naphthalene type bifunctional epoxy resin (molecular weight 314) manufactured by Dainippon Ink & Chemicals, Inc.
HP4700: Naphthalene type tetrafunctional epoxy resin (molecular weight 648) manufactured by Dainippon Ink & Chemicals, Inc.
jER604: Japan Epoxy Resin N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane (average molecular weight 480)
DDS: 4,4'-diaminodiphenylsulfone (molecular weight 248) manufactured by Wakayama Seika
(Examples 1 and 2)
390 g of jER807, 260 g of jER630, and 350 g of BXP were charged in a reaction vessel, reacted at 100 ° C. for 1 hour, added with 10 g of triphenylphosphine and further reacted at 100 ° C. for 3 hours to complete the preliminary reaction, and the oligomer (A) Got.

  Mix (A) component, jER807 as component (B), jER604 as component (C), DDS as component (D) at the ratio shown in Table 1, and mix thoroughly at 60 ° C until the whole becomes uniform did. The obtained mixture was sandwiched between glass plates and cured at 180 ° C. for 2 hours to obtain a resin plate.

The obtained cured resin plate having a thickness of 2 mm was subjected to a three-point bending test in accordance with ASTM D790, and the strength, elastic modulus, and elongation at break were calculated.

  The heat resistance of the cured resin was evaluated as follows. The graph is plotted with the storage elastic modulus G ′ measured with a rheometer (RDA-700, RDA-700) held at 5 ° C. for 3 minutes and applied with a stress of 10 radians / second on the vertical axis and the temperature on the horizontal axis. The point where the flat part of G ′ and the tangent of the transition region intersect each other was taken as the glass transition temperature of the cured resin. The temperature at which the ratio of loss elastic modulus to storage elastic modulus tan δ was maximized was defined as tan δ max.

The results are shown in Table 1. All showed higher heat resistance than the comparative examples listed below.

(Comparative example)
Resin plates were obtained at the ratios shown in Table 1 in the same manner as in the Examples except that the component (B) was not included. The results are shown in Table 1.

Claims (5)

The resin composition for composite material intermediate materials having the following (A) to (D) as essential components.
(A) 20-60 mol% of bisphenol F type epoxy resin, 20-50 mol% of p-aminophenol type epoxy resin, 20-50 mol% of phenol compound represented by chemical formula (I) is obtained by preliminary reaction. 15-60 parts by mass of oligomer

(B) 10 to 40 parts by mass of an epoxy resin having a naphthol glycidyl ether structure represented by the chemical formula (II)

(C) Other 2- to 4-functional epoxy resin 15-75 parts by mass (D) Diaminodiphenyl sulfone: 90-175% equivalent of theoretical equivalent The resin composition for composite material intermediate material according to claim 1, wherein (B) is an epoxy resin represented by chemical formula (III).

The resin composition for composite material intermediate material according to claim 1, wherein (B) is an epoxy resin represented by chemical formula (IV).

The resin composition for a composite material intermediate material according to claim 2, wherein (C) is N, N, N ', N'-tetraglycidyldiaminodiphenylmethane. The resin composition for a composite material intermediate material according to claim 3, wherein (C) is N, N, N ', N'-tetraglycidyldiaminodiphenylmethane and a bisphenol F type epoxy resin.