JPH06211999A - Prepreg composition - Google Patents

Abstract

PURPOSE:To provide a molded article having excellent toughness and heat resistance while retaining a good moldability. CONSTITUTION:This prepreg compsn. is obtd. by impregnating a reinforcement with a resin compsn. which comprises a glycidyl compd. of formula I [wherein Ar is a 6-20C (not including carbon atoms of the glycidyloxy group described below) mono to tetravalent arom. hydrocarbon group having at least one glycidyloxy group bonded to an arom. ring; R is H or methyl; and (n) is an integer of 1-4], a curative, a radical polymn. initiator, and a polyarylate having repeating units of formula II (wherein (m) is an integer of 1-500) in an amt. of 5-50 pts.wt. based on 100 pts.wt. the compsn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel prepreg composition capable of obtaining a molded product having excellent heat resistance and toughness.

[0002]

2. Description of the Related Art A composite material composed of a fiber-based reinforcing material and a matrix resin is utilized for sports and industrial materials such as golf club shafts and fishing rods by taking advantage of its high specific strength and specific elastic modulus. -It has been widely used for structural materials such as aircraft. As an intermediate material for molding for these applications, a material in the form of a prepreg in which an uncured matrix resin is impregnated with a reinforcing material in advance is often used, and an epoxy resin is used as a resin for such a prepreg. Although generally used, further improvement in not only strength and elastic modulus but also toughness, heat resistance, water resistance, etc. is desired. Above all, there is a great demand for a material having both high toughness and heat resistance. For example, N, N, N ', N'-tetraglycidyldiaminodiphenylmethane is currently used together with diaminodiphenylsulfone as a curing agent in aircraft applications. However, the cured product has high heat resistance but low toughness, and a composite material using such a resin as a matrix resin also has a drawback of low toughness.

In general, a cured product using a thermosetting resin tends to have low toughness when its heat resistance is increased, on the other hand. On the other hand, many thermoplastic resins have relatively high toughness, and some have high heat resistance as seen in some aromatic polymers, but these have been molded at high temperatures. Therefore, it is inferior to thermosetting resins such as epoxy resins in terms of moldability. From such a background, a molding material having high heat resistance and high toughness while maintaining good moldability is desired.

In recent years, attempts have been made to supplement the low toughness of thermosetting resins by incorporating a thermoplastic resin having a relatively high heat resistance into a thermosetting resin such as an epoxy resin, and some have good properties. Is starting to appear. However, it cannot be said that the phase-separated structure of the molded product using these materials is homogeneous, and it is still insufficient for the development of stable properties.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the problem that the structure in the molded body is inhomogeneous as described above,
It is intended to provide a novel prepreg composition capable of maintaining a good molded product and stably obtaining a molded product having excellent toughness and heat resistance.

[0006]

As a result of intensive studies to solve the above problems, the inventors of the present invention have found that a combination of specific components provides high heat resistance while maintaining good moldability. It was found that a composite material having both excellent properties and high toughness can be obtained, and the present invention has been completed. That is, the present invention contains the following (a) to (d) as essential components, and the amount of the component (d) is 5 relative to 100 parts by weight of the total amount of the resin composition.
The content is a prepreg composition obtained by impregnating a reinforcing material with 100 to 100 parts by weight of a resin composition. (A) The following structural formula (1)

[0007]

[Chemical 5]

[In the formula, Ar is a C _{6 to} C ₂₀ having at least one glycidyloxy group bonded to an aromatic ring (provided that
The number of carbon atoms in the glycidyloxy group is not included. ) 1-4
Represents a valent aromatic hydrocarbon group, R is a hydrogen atom or a methyl group, and n is an integer of 1 to 4. ] The glycidyl compound shown by these, (b) hardener, (c) radical polymerization initiator, (d) following structural formula (2)

[0009]

[Chemical 6]

(In the formula, m is an integer of 1 to 500.)
A polyarylate having a repeating unit represented by:

The present invention will be described in detail below. The first of the features of the prepreg composition of the present invention is that the resin composition used in the present invention has thermosetting properties as a whole, and thus good molding of a prepreg obtained from a general thermosetting resin is achieved. There is a point that can maintain sex. The second characteristic of the prepreg composition of the present invention is that among the components contained in the resin composition used in the present invention by heating at the time of molding, of the vinyl group of the glycidyl compound (a) by the radical polymerization initiator (c). The reaction, the reaction of the epoxy group of the glycidyl compound (a) and the curing agent (b), the phase converted into a three-dimensional crosslinked product and the phase mainly composed of the polyarylate (d) are both continuous and finely enter each other. A homogeneous phase-separated structure that is mixed can be obtained, which makes it possible to stably impart good properties having both high heat resistance and high toughness to a molded article using the prepreg composition of the present invention. is there.

With the prepreg composition of the present invention, a molded product can be obtained by allowing the curing reaction to proceed mainly by heating. This is because the resin composition used in the present invention has a property that it can be made into a resin-cured product mainly by proceeding a curing reaction by heating, and the resin-cured product is a matrix in a molded product. Form a resin. At this time, the polymerization reaction and the spinodal decomposition type phase separation that proceed by being controlled mainly by the heating conditions, the type and amount of the radical polymerization initiator (c) and the amount of the curing agent (b) used, and the respective components Due to the combined effect of the interaction derived from the chemical structure, the reaction of the vinyl group of the glycidyl compound (a) with the radical polymerization initiator (c), the epoxy group of the glycidyl compound (a) and the curing agent (in the cured resin). It is possible to develop a homogeneous phase-separated structure in which the phase converted into the three-dimensional crosslinked product by the reaction of b) and the phase formed of polyarylate (d) are both continuous and finely mixed with each other. More specifically, by suppressing the phase separation to a fine level by controlling the polymerization reaction and the interaction between the respective components, and controlling the polymerization reaction to make the crosslinked structure homogeneous, The phase-separated structure can be made more homogeneous. As a result, the cured resin product can have high heat resistance and high toughness, and as a result, the molded product obtained from the prepreg composition of the present invention has excellent heat resistance and high toughness. Can be stably applied.

The method of impregnating the reinforcing material with the resin composition is not particularly limited. For example, each essential component of the resin composition is mixed and stirred in a heat-melted state to be substantially uniform, and then the reinforcing material is formed into a reinforcing material by a hot pressing method. It can be impregnated by a method usually used for prepreg production, such as a method of impregnating or a method in which a reinforcing material is immersed in a solution in which a resin composition is substantially uniformly dissolved to impregnate the solution and then desolvation is performed. .

The reinforcing material used in the present invention is not particularly limited, but it is preferably a fibrous material having high strength, elastic modulus and heat resistance. Examples of such fibers include carbon fibers, glass fibers, aramid fibers, alumina fibers, silicon carbide fibers, tyranno fibers, boron fibers and the like. The shape is not particularly limited, and any shape such as a strand, a tape, a sheet-like material, a mat-like material, a woven material, or a braid, which are arranged singly or in combination of a plurality of kinds in a certain direction, can be used.

The glycidyl compound (a) used in the present invention can be used as long as it has a structure represented by the structural formula (1). Since the component (a) has an acrylamide group and an epoxy group, it can be made into a polymer by the reaction of each functional group. However, these reactions and the polymer structure are different from those of the curing agent (b) used in the present invention. )
And the radical polymerization initiator (c) can be widely controlled by the type and the amount of the radical polymerization initiator (c) used. In order to impart good characteristics to the molded product obtained from the thermosetting resin composition of the present invention, one of the important points is to control the progress of each polymerization reaction of the component (a). . Specifically, the polymerization reaction of the acrylamide group of the glycidyl compound (a) and the epoxy group of the component (a) and the curing agent (b)
It is essential that the curing reaction with and proceed in parallel. When the polyarylate (d) used in the present invention coexists, the polymerization reaction of the acrylamide group and the curing reaction of the epoxy group and the curing agent (b) are allowed to proceed in parallel to reduce the phase separation to a fine level. It can be suppressed, and if either reaction is made to precede too much, phase separation becomes severe with the progress of the polymerization reaction, and good characteristics cannot be obtained. In addition, polymerization reaction of acrylamide group and epoxy group and curing agent (b)
By allowing the curing reaction with and to proceed in parallel, cross-linking proceeds relatively quickly, so that the above phase-separated structure can be homogenized.

Preferred examples of the glycidyl compound (a) include compounds represented by the structural formulas (3) and (4). The component (a) may be used alone or in combination of two or more kinds. Structural formula (3),
The compound represented by (4) is, for example, an aromatic hydrocarbon compound having at least one phenolic hydroxyl group and N-
It is obtained by condensing an alkyl ether of methylol acrylamide or N-methylol methacrylamide in the presence of an acid catalyst, and further reacting the condensation product with epichlorohydrin in the presence of a phase transfer catalyst.
The detailed manufacturing method of the compounds represented by the structural formulas (3) and (4) is described in JP-B-2-51550.

The curing agent (b) used in the present invention acts on the glycidyl compound (a) to promote the formation of an epoxy polymer network. The reaction rate of the prepreg composition of the present invention, the prepreg of the present invention, and the like. It can be appropriately selected according to the desired physical properties of the molded product using the composition. Of the components (b), those which impart good heat resistance and toughness to the molded article using the prepreg composition of the present invention in a well-balanced manner are preferred, for example, diaminodiphenyl ether, diaminodiphenyl sulfone, 4,4'-methylenediene. Aniline, benzidine, 4,4'-bis (o-toluidine), 4,4'-thiodianiline, o-phenylenediamine, dianidine, methylenebis (o-chloroaniline), m-phenylenediamine, 2,4-toluenediamine, Diaminoditrisulphone, 4-methoxy-6-
Aromatic amine-based curing agents such as methyl-m-phenylenediamine, 2,6-diaminopyridine, 4-chloro-o-phenylenediamine, m-aminobenzylamine, bis (3,4-diaminophenyl) sulfone; anhydrous methyl Acid anhydride curing agents such as tetrahydrophthalic acid, methyl nadic acid anhydride, pyromellitic acid anhydride, and methyl hexahydrophthalic acid anhydride; 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1 Examples include imidazole curing agents such as -benzyl-2-methylimidazole and 2-phenylimidazole; latent curing agents such as boron trifluoride-monoethylamine complex and boron trifluoride-diethylamine complex. These may be used alone or in combination of two or more.

The amount of the curing agent (b) used is not particularly limited, but the aromatic amine curing agent is the epoxy 1 of the component (a).
A preferable equivalent can be selected within a range of 0.5 to 2.0 as the amine equivalent, and more preferably 0.7 to 0.7 as the amine equivalent.
It is 1.4. The acid anhydride-based curing agent can select a preferable acid anhydride equivalent in the range of 0.5 to 1.5 with respect to 1 equivalent of the epoxy of the component (a), and more preferably an acid anhydride equivalent of 0.7 to 1. .2. A preferable amount of the imidazole curing agent can be selected within a range of 0.1 to 30 parts by weight, and more preferably 1 to 15 parts by weight, based on 100 parts by weight of the component (a). The latent curing agent can be selected in a preferred amount within the range of 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight, relative to 100 parts by weight of the component (a). If the amount of the component (b) used is too small, the heat resistance and toughness decrease,
If it is too much, the heat resistance will decrease. In the present invention, if necessary, a curing accelerator that accelerates the reaction between the glycidyl compound (a) and the radical polymerization initiator (c) and the curing agent (b) and the radical polymerization initiator (c) may be added. . As the curing accelerator, any generally known one can be arbitrarily used. Examples thereof include ureas, phosphines, phenols, alcohols, organic acids, inorganic acids, polymercaptans and the like.

Radical polymerization initiator (c) used in the present invention
Is to generate radicals by heating during molding to initiate radical polymerization of the glycidyl compound, and to use one having a desired radical generation rate to control reactivity according to the molding temperature. However, organic peroxides are preferable from the viewpoints of handleability and the like.
The amount of component (c) used is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the glycidyl compound. If it is less than 0.1 part by weight, the radical polymerization rate is remarkably reduced, and if it exceeds 5 parts by weight, the radical polymerization rate is remarkably increased, and in any case, a desired homogeneous phase separation structure is not developed, so that both heat resistance and toughness are not exhibited. Tends to decline.

Polyarylate (d) used in the present invention
Is not particularly limited as long as it is a polyarylate having the repeating unit represented by the structural formula (2). However, if the molecular weight is too small, the effect of imparting toughness is small, and if the molecular weight is too large, the handling property decreases. Those having a molecular weight of up to 200,000 are preferred. The component (d) is, for example, 1,1-bis (4-hydroxyphenyl) -phenylethane, p- (t-butyl) phenol which is a molecular weight regulator, sodium hydrosulfide which is a reducing agent, sodium hydroxide and After mixing water in a nitrogen atmosphere, the mixture is cooled to prepare an alkaline aqueous solution of bisphenol. Further, isophthalic acid chloride is dissolved in methylene chloride, benzyltributylammonium chloride is added as a polymerization catalyst, the prepared alkaline aqueous solution is mixed, and interfacial polycondensation is performed while cooling and stirring. After completion of the polymerization, the methylene chloride phase containing the target polymer was washed with neutralized water, the same amount of acetone was gradually added to precipitate a polymer powder, and after filtration, the powder was washed with the same amount of acetone and water. The component (d) can be obtained by drying. The amount of the component (d) used is preferably 5 to 50 parts by weight based on 100 parts by weight of the total amount of the resin composition of the present invention. When the amount is less than this, the toughness is insufficiently imparted, and when the amount is more than this. The moldability of the composition becomes insufficient.

In the prepreg composition of the present invention, various additives can be used in addition to the components used in the present invention within the range where the effect can be exhibited. Examples of such additives include fillers such as calcium carbonate and aluminum hydroxide, liquid or solid rubber, halogen compounds, flame retardants such as antimony trioxide, coupling agents, colorants, epoxy compounds, and styrene. Examples thereof include reactive diluents such as monomers, which may be used alone or in combination of two or more. Further, in the present invention, the component (a) of the present invention within the range where the effect can be exerted,
Curable monomers and oligomers other than (b) and (d),
Of course, thermoplastic resins and hardeners can be used.

[0022]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited thereto. Reference Example: Polymerization of polyarylate 1,1-bis (4-hydroxyphenyl) -phenylethane 678.0 g (2.97 mol), p- (t-butyl) phenol 9.0 g (0.06 mol), sodium Hydrosulfide 5.28g, 4N sodium hydroxide 1920ml and water 3320ml 6 in a nitrogen atmosphere
After mixing in a liter flask, the mixture was cooled to 5 ° C. to prepare an alkaline aqueous solution of bisphenol. On the other hand, in another 6 liter flask, add isophthalic chloride 60
9.06 g (3.0 mol) was dissolved in 5000 ml of methylene chloride and cooled to 5 ° C. Then, in a further 15 liter separable flask, 2000 ml of water and benzyltributylammonium chloride as a catalyst 0.9
4 g (0.03 mol) was charged under a nitrogen atmosphere,
Cooled to 5 ° C. While vigorously stirring the cooling liquid, the above-mentioned two liquids prepared in advance were simultaneously added continuously for 15 minutes by using a pump. When the stirring was stopped 60 minutes after the addition was completed, the mixture was separated into a methylene chloride phase and an aqueous phase. After decanting the aqueous phase, the same amount of water was added and neutralized with a small amount of hydrochloric acid while stirring. Further, after repeating desalting by washing with water, the same amount of acetone was gradually added to the methylene chloride phase to precipitate a polymer powder, and after filtration, the powder was washed with the same amount of acetone and water, and again in the same manner. Filtered. The weight average molecular weight of the dried polymer by GPC (gel permeation chromatography) was 62,000.

Example 1 A glycidyl compound (AXE, manufactured by Kanegafuchi Chemical Industry Co., Ltd.) was added to a mixed solvent of methylene chloride / methanol (95/5).
100 parts by weight, 23.8 parts by weight of diaminodiphenyl sulfone, 1.5 parts by weight of t-butyl peroxybenzoate (Perbutyl Z, manufactured by NOF CORPORATION) and 31.3 parts by weight of polyarylate obtained in Reference Example were dissolved. After immersing and aligning carbon fibers (Vesphite HTA, manufactured by Toho Rayon Co., Ltd.) in the prepared solution, the solvent was removed under reduced pressure to obtain a unidirectional prepreg. Laminate this prepreg for 150
C, 10kg / cm ² pressure molding for 1 hour, then 180
Post-curing was performed at 2 ° C. for 2 hours to obtain a laminated plate having a thickness of 3 mm. This laminated plate was cut into a length of 200 mm and a width of 25 mm, pre-cracked with about 40 mm, and the energy release rate G1C was determined by a double cantilever beam (DCB) test. As a result, the obtained G1C was 500 J / m ² , and the glass transition temperature Tg was 213 ° C.

Comparative Example 1 A bisphenol A type epoxy compound (EPIKOTE82) was added to a mixed solvent of methylene chloride / methanol (95/5).
Carbon fiber in a solution in which 100 parts by weight of Yuka Shell Epoxy Co., Ltd.), 32.6 parts by weight of diaminodiphenyl sulfone, and 33.2 parts by weight of polyetherimide (Ultem 100, manufactured by GE Plastics Co., Ltd.) are dissolved. (Vesphite HTA, manufactured by Toho Rayon Co., Ltd.) was immersed and aligned, and then the solvent was removed under reduced pressure to obtain a unidirectional prepreg. Laminate this prepreg for 150
C, 10kg / cm ² pressure molding for 1 hour, then 180
Post-curing was performed at 2 ° C. for 2 hours to obtain a laminated plate having a thickness of 3 mm. As a result of obtaining the energy release rate G1C in the same manner as in Example 1, the obtained G1C was 400 J / m ² , and the glass transition temperature Tg was 190 ° C.

[0025]

EFFECTS OF THE INVENTION The present invention can provide a prepreg composition capable of stably obtaining a molded product having excellent toughness and heat resistance while maintaining good moldability.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C08L 67/03 LPC 8933-4J

Claims (6)

[Claims] 1. A resin composition containing the following components (a) to (d) as essential components and containing 5 to 100 parts by weight of component (d) per 100 parts by weight of the total resin composition. A prepreg composition obtained by impregnating a material. (A) Structural formula (1) below: [In the formula, Ar is a C _{6 to} C ₂₀ aromatic hydrocarbon group having at least one glycidyloxy group bonded to an aromatic ring (however, the number of carbon atoms in the glycidyloxy group is not included). R is a hydrogen atom or a methyl group, and n
Is an integer of 1 to 4. ] The glycidyl compound shown by these, (b) hardener, (c) radical polymerization initiator, (d)
The following structural formula (2): (In the formula, m is an integer of 1 to 500.) A polyarylate having a repeating unit represented by the formula. 2. The prepreg composition according to claim 1, wherein the component (a) is represented by the structural formula (3). [Chemical 3] (In the formula, R represents a hydrogen atom or a methyl group.) 3. The prepreg composition according to claim 1, wherein the component (a) is represented by the structural formula (4). [Chemical 4] (In the formula, R represents a hydrogen atom or a methyl group, and l is 1 or 2.) 4. The prepreg according to claim 1, wherein the component (b) is at least one selected from the group consisting of an aromatic amine curing agent, an acid anhydride curing agent, an imidazole curing agent and a latent curing agent. Composition. 5. The prepreg composition according to claim 1, wherein the component (c) is an organic peroxide. 6. The prepreg composition according to claim 1, wherein the polyarylate as the component (d) has a molecular weight of 5,000 to 200,000.