JPH08259713A - Prepreg and fiber-reinforced composite material - Google Patents

Abstract

PURPOSE: To obtain a prepreg giving a fiber-reinforced composite material which has excellent compression mechanical properties, in particular excellent strength in wet heat compression with a perforated plate, has excellent compression strength after impact, and is suitable for use as a structural material. CONSTITUTION: The prepreg comprises reinforcing fibers, an epoxy resin composition which gives a cured resin having a modulus of elasticity flexure of 380kgf/ mm<2> or higher, and a particulate, fibrous, or filmy thermoplastic resin distributed around the surface of one or both sides of the prepreg. This prepreg is cured to obtain the objective composite material.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a prepreg for producing a fiber-reinforced composite material. More specifically, it relates to a prepreg that is excellent in the mechanical properties of a compression system and gives a fiber-reinforced composite material suitable as a structural material.

[0002]

2. Description of the Related Art Polymer-based composite materials composed of reinforcing fibers and matrix resins are widely used in sports equipment, aerospace applications, and general industrial applications because of their light weight and excellent mechanical properties. In the manufacture of fiber reinforced composite materials,
Although various methods are used, a method using a prepreg which is a sheet-shaped intermediate base material in which reinforcing fibers are impregnated with a matrix resin is widely used. In this method, a molded article of a composite material is obtained by stacking a plurality of prepregs and then heating them.

As the matrix resin used in the prepreg, both thermosetting resins and thermoplastic resins are used, but in most cases, curable resins having excellent handleability are used, and among them, epoxy resins are the most used. Has been done. Further, a maleimide resin, a cyanate resin and a combination thereof are also often used.

Compressive strength is one of the important physical properties when a composite material is used as a structural material. Since bolt holes are often provided when used as a structural member, the compressive strength of a perforated plate is particularly important.

In general, a polymer material has low strength and elastic modulus under high temperature or high humidity conditions. Therefore, the physical properties such as strength of the fiber-reinforced composite material using the polymer as a matrix are likely to be deteriorated under high temperature or high humidity conditions. However, when the composite material is applied as a structural material for aircraft, vehicles, ships, etc., it is required to sufficiently maintain the physical properties even under high temperature or high humidity conditions.

Compressive strength is a particularly important physical property when composite materials are used as structural materials. The compressive strength is measured using a test piece such as a non-perforated plate, a perforated plate, or a cylinder.In actual use, it is often a plate material with bolt holes, The compressive strength of the perforated plate, especially the strength under high temperature and high humidity conditions, becomes important.

Impact resistance is also important when using composite materials as structural materials. A particularly important physical property for impact resistance is post-impact compressive strength. This is because there is a phenomenon in which the composite material is delaminated between layers of the composite material due to the impact on the member due to the drop of the tool or the collision of small stones, and the compressive strength is lowered.

In order to improve the compressive strength of the composite material, it is generally effective to increase the elastic modulus of the matrix resin. It is possible to increase the elastic modulus of the epoxy resin cured product by selecting raw materials to be mixed. However, in general, epoxy resin cured products having a high elastic modulus have low toughness, that is, they are brittle, so that impact resistance, especially compressive strength after impact, and further properties such as fatigue become poor. Could not be used.

On the other hand, when a matrix resin is used as a cured product of a high toughness epoxy resin which has a high compressive strength after impact, in general, these resins cannot have a very high elastic modulus, so that a fiber having a high compressive strength is obtained. It was not possible to obtain a reinforced composite material.

As described above, at present, high compressive strength,
In particular, a material capable of satisfying both the compressive strength of a perforated plate and high impact resistance, especially the compressive strength after impact, has not been obtained.

[0011]

The object of the present invention is to provide a fiber-reinforced composite material which is very excellent in the mechanical properties of the compression system, in particular, the perforated plate compressive strength during wet heat and the compressive strength after impact, and which is suitable as a structural material. It is to provide prepreg.

[0012]

The prepreg of the present invention comprises:
In order to achieve the said subject, it has the following structures. That is, the prepreg is composed of the following constituent elements (A), (B), and (C), and the constituent element (C) is distributed near the surface layer on one side or both sides.

(A) Reinforcing fiber (B) Epoxy resin composition having a cured product having a flexural modulus of 380 kgf / mm ² or more (C) Thermoplastic resin particles, fiber, or film The reinforced composite material has the following constitution in order to achieve the above object. That is, it is a fiber-reinforced composite material obtained by curing the prepreg.

The present invention will be described in detail below.

In the prepreg of the present invention, the cured product has a high elastic modulus, specifically, an epoxy resin composition having a flexural elastic modulus of the cured product of 380 kgf / mm ² or more is used as a matrix resin, whereby the prepreg has pores. By increasing the plate compressive strength and increasing the post-impact compressive strength by strengthening the interlayer with a thermoplastic resin, it is possible to achieve both high perforated plate compressive strength and post-impact compressive strength, which were not possible conventionally.

As the reinforcing fiber (A) used in the present invention,
Glass fiber, carbon fiber, aramid fiber, boron fiber, alumina fiber, silicon carbide fiber and the like are used. Of these, carbon fiber is particularly preferable. As the form of the reinforcing fibers, long fibers aligned in one direction, tows, woven fabrics, mats, knits, braids and the like are used.

As the epoxy resin composition (B) used as a matrix, a cured product thereof having a high elastic modulus, specifically, a bending elastic modulus at room temperature of 380 kgf / mm ² or more is used.

The room temperature flexural modulus of the cured product of the epoxy resin composition (B) was measured by curing and cutting the epoxy resin composition using the same curing temperature and curing time as the prepreg curing conditions. A test piece with a width of 10 mm and a length of 60 mm is prepared, and is measured at 25 ° C. with a 3-point bend with a span of 32 mm.

When the fiber reinforced composite material is used as a structural material, it is necessary that the deterioration of physical properties at high temperature and high humidity is small. It is important in this respect that the decrease in the elastic modulus of the matrix resin at high temperature and high humidity is small. The flexural modulus of the matrix resin (cured product) at high temperature and high humidity is measured as follows. A cured product of the resin composition (B) is used as a test piece having the same dimensions as in room temperature elastic modulus measurement, immersed in boiling water for 20 hours, and then subjected to three-point bending measurement at 82 ° C. with a span interval of 32 mm.
The flexural modulus at high temperature and high humidity is preferably 280 kgf / mm ² or more, and more preferably 320 kgf / mm ² or more.

The epoxy resin composition (B) is mainly composed of
It consists of epoxy resin and curing agent.

The epoxy resin is bisphenol A.
Type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol B type epoxy resin, naphthalene type epoxy resin, novolac type epoxy resin, epoxy resin having fluorene skeleton,
Epoxy resin made from a copolymer of phenol compound and dicyclopentadiene, diglycidyl resorcinol, tetrakis (glycidyloxyphenyl) ethane,
Glycidyl ether type epoxy resins such as tris (glycidyloxyphenyl) methane, tetraglycidyl diaminodiphenylmethane, triglycidyl aminophenol, triglycidyl aminocresol, glycidyl amine type epoxy resins such as tetraglycidyl xylene diamine and mixtures thereof are used. However, it is not limited to this.

In order to realize a high elastic modulus of the resin cured product, it is preferable that 70% or more of the epoxy resin component is a trifunctional or more functional epoxy resin. Trifunctional or higher functional epoxy resins include glycidyl ether type epoxy resins such as tetrakis (glycidyloxyphenyl) ethane and tris (glycidyloxyphenyl) methane, tetraglycidyldiaminodiphenylmethane, triglycidylaminophenol, triglycidylaminocresol, tetraglycidyl. There are glycidyl amine type epoxy resins such as xylene diamine, naphthalene type epoxy resins, and novolac type epoxy resins. Of these, one kind or two or more kinds may be blended and used. In particular, it is preferable to add tetraglycidyldiaminodiphenylmethane, which is a tetrafunctional glycidylamine type epoxy resin, as a main component because the elastic modulus is not lowered under high temperature and high humidity conditions.

Further, a bifunctional epoxy resin having a rigid skeleton, for example, an epoxy resin having a naphthalene skeleton, an epoxy resin having a fluorene skeleton, a biphenyl skeleton, or a dicyclopentadiene skeleton in the molecule, can be blended. It is also preferable because it has the effects of realizing a high elastic modulus and a small decrease in elastic modulus under high temperature and high humidity conditions.

As the curing agent, aromatic amines such as diaminodiphenylmethane and diaminodiphenylsulfone, aliphatic amines, imidazole derivatives, dicyandiamide, tetramethylguanidine, thiourea-added amine,
Examples thereof include carboxylic acid anhydrides such as methylhexahydrophthalic anhydride, carboxylic acid hydrazides, carboxylic acid amides, polyphenol compounds, novolac resins, polymercaptans, and Lewis acid complexes such as boron trifluoride ethylamine complex. It is not limited to.

These hardening agents may be combined with a suitable hardening aid to enhance the hardening activity. As a preferable example, dicyandiamide is added to 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU).
And the like, and examples of combining a carboxylic acid anhydride or a novolac resin with a tertiary amine as a curing aid.

In order to obtain a cured product having a high elastic modulus and a small elastic modulus decrease under high temperature and high humidity conditions, it is preferable to use diaminodiphenyl sulfone as a curing agent, and particularly, among its isomers, It is particularly preferred to use 3'-diaminodiphenyl sulfone.

The epoxy resin composition (B) may further contain a thermoplastic resin soluble in the epoxy resin. As the thermoplastic resin, those having a high elastic modulus and a high glass transition temperature are preferable, and specific examples thereof include polysulfone, polyether sulfone, polyimide, and polyether imide.

In order to increase the compressive strength after impact, a high toughness material is present in the vicinity of one or both surfaces of the prepreg, and the high toughness material is distributed between the layers of the composite material obtained by laminating and curing. It is known that the above method is effective. As the high toughness material, for example, JP-A-63-16273
Thermoplastic resins such as those disclosed in Japanese Patent Publication No.
There is known a method using an elastomer as disclosed in 4-268361, for example, an elastomer-modified thermosetting resin as disclosed in US Pat. No. 3,472,730.

The above-mentioned interlaminar strengthening technique is also applied to the present invention. When the interlaminar strengthening technique is applied to the present invention, when an elastomer or an elastomer-modified thermosetting resin is used as a material for interlaminar strengthening, A thermoplastic resin is used because the physical properties at the time deteriorate. The interlayer strengthening referred to in the present invention refers to a technique of localizing a thermoplastic resin component in the interlayer portion and strengthening the laminated layers. Therefore, the material used for the interlayer reinforcement is strictly distinguished from the epoxy-soluble thermoplastic resin which is added to the epoxy resin composition (B) and uniformly distributed throughout the whole.

Any known thermoplastic resin can be used as the thermoplastic resin to be present in the vicinity of the surface of one or both surfaces of the prepreg, but in order to make the fiber-reinforced composite material excellent in compressive strength after impact, Those having good adhesiveness with the epoxy resin are preferable. As the thermoplastic resin having good adhesiveness to the epoxy resin, a resin having an amide bond, an imide bond or a sulfonyl group is preferable. Specifically, polyamide, polyimide, polyetherimide, polyamideimide, polysulfone, polyethersulfone and the like are preferable.

The thermoplastic resin used here may be a crystalline one or an amorphous one, but in any case, it is excellent in heat resistance so as not to lower the heat resistance of the prepreg. Is preferred. The crystalline one preferably has a melting point of 120 ° C. or higher, more preferably 150 ° C. or higher. In addition, the amorphous one has a glass transition point of preferably 120 ° C. or higher, more preferably 150 ° C. or higher.

The thermoplastic resin used here is disclosed in JP-A-1-10
It is also possible to use those modified with an epoxy resin as shown in Japanese Patent No. 4624. Those modified in this way are effective in improving solvent resistance or heat resistance. It is also possible to use a thermoplastic resin treated with corona, plasma, electron beam or the like. These treatments are effective in improving solvent resistance or adhesiveness with epoxy resin.

The form of the thermoplastic resin is a film,
Particles and fibers can be taken.

In film form, US Pat. No. 4,604,319
If the surface of the prepreg is completely covered as in Japanese Patent Publication No. 63-97635, the surface tack is lost, but as shown in Japanese Patent Laid-Open No. 63-97635, a through hole is provided, as shown in Japanese Patent Laid-Open No. 5-138785. The surface tack can be retained by adopting a method such as making it porous or arranging a tape-shaped film as shown in JP-A-5-287091.

In the case of the particle form, the shape of the particles is
Even spherical particles as shown in JP 110537, JP-A 1-
Even non-spherical particles such as those disclosed in Japanese Patent No.
It may be a porous particle as disclosed in JP-A-5-1159.

As the fiber form, both short fibers and long fibers can be used. In the case of short fibers JP-A-2-6956
It is possible to use a method in which short fibers are used in the same manner as particles as shown in JP-B-6, or a method in which a short fiber is processed and used. In the case of long fibers, a method of arranging the long fibers in parallel with the surface of the prepreg as shown in JP-A-4-292634 and a method of randomly arranging as shown in International Publication No. 94016003 are possible. Further, it can be used after being processed into a woven fabric as shown in JP-A-2-32843, a nonwoven fabric as shown in International Publication No. 94016003, or a sheet-like base material such as a knitted fabric. In addition, short fibers are spun yarns and are arranged in parallel or randomly, woven fabric,
A method in which the knitted material is processed and used can also be used.

The preferable amount of the thermoplastic resin used for the interlaminar reinforcement is 4 to 15 g / m ² per surface with respect to the surface on which it is present.
Is.

The prepreg of the present invention can be manufactured by several methods.

The first method is the epoxy resin composition (B).
Using a film coated on a release paper or the like, a resin is impregnated from both sides or one side of a sheet-shaped reinforcing fiber to prepare a primary prepreg, and the component (C) is sprayed on both sides or one side. It is a method of sticking. Here, when the component (C) is a resin-impregnable sheet-like material such as a porous film, a woven fabric, a mat, a non-woven fabric, or a knitted fabric, it is impregnated with the epoxy resin composition (B) in advance and attached. It is also possible.

The second method is the epoxy resin composition (B).
Is coated on a release paper or the like to form a primary prepreg by impregnating the sheet-shaped reinforcing fibers with resin from both sides or one side, and the epoxy resin composition (B) is placed on the release paper or the like. This is a method in which the component (C) is sprinkled or attached to the surface of another coated film and attached to both sides or one side of the primary prepreg.

The third method is the epoxy resin composition (B).
An epoxy prepared by kneading the particles or short fibers of the constituent element (C) with a resin coated on a release paper or the like to impregnate the sheet-like reinforcing fibers with resin from both sides or one side to prepare a primary prepreg. In this method, a film obtained by coating a release paper or the like with the resin composition (B) is attached to both sides or one side of a primary prepreg.

The fourth method is to construct the components (A), (B),
(C) is applied at the same time and is applied when the component (C) is in the form of a sheet (film, woven fabric, mat, knitted fabric, non-woven fabric, etc.) or yarn (long fiber, spun yarn, tape-shaped film). It is a possible method.

Such a prepreg is usually laminated and cured to form a fiber-reinforced composite material. The resulting composite material is suitable as a structural material because it is excellent in the mechanical properties of the compression system, particularly the compressive strength of the perforated plate when wet and hot, and the compressive strength after impact.

[0044]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.

(Example 1) (a) Preparation of particles Amorphous polyetherimide "Ultem (registered trademark) 10"
An emulsion was obtained by adding 1400 g of a 5% aqueous polyvinyl alcohol solution to a solution prepared by dissolving 180 g of "00" (manufactured by General Electric Co., glass transition temperature: 213 ° C) in 1 kg of methylene chloride while stirring.
The mixture was heated in an oil bath at 60 ° C to remove the solvent, and the obtained slurry was filtered and washed with water to obtain 155 g of Ultem particles. The particle size was about 20 microns when observed by a scanning electron microscope.

(B) Preparation of resin composition The following raw materials were kneaded to obtain an epoxy resin composition.

(1) Tetraglycidyldiaminodiphenylmethane (ELM434, manufactured by Sumitomo Chemical Co., Ltd.) 90.0 parts (2) Bisphenol A type epoxy resin (Epicoat 825, manufactured by Yuka Shell Epoxy Co., Ltd.) 10.0 parts (3) Polyether sulfone (PES5003P, manufactured by Sumitomo Chemical Co., Ltd.) 12.3 parts (4) 3,3'-diaminodiphenyl sulfone (manufactured by Wakayama Seika Co., Ltd.) 36.0 parts (c) Resin curing Physical property measurement of the product The resin prepared in (b) was cured at 180 ° C. for 2 hours to prepare a plate having a thickness of 2 mm of the cured resin product. Flexural modulus measurement is 2m
A m-thick plate was cut into a width of 10 mm and a span of 32 mm was used.

The room temperature flexural modulus of the cured product is 420 kgf / mm ²
The flexural modulus measured at 82 ° C. after absorption of boiling water for 20 hours was 330 J / m ² .

(D) Preparation of prepreg The primary resin prepared in (b) was coated on release paper using a reverse roll coater so that the coating amount was 45.7 g / m ² , to prepare a resin film.

Carbon fibers (T800H, manufactured by Toray Industries, Inc.) aligned in one direction were sandwiched from both sides with the primary resin film and heated and pressed to impregnate the resin. Further, on both sides thereof, the polyetherimide "Ultem" 1 prepared in (a)
000 particles were applied. The amount of spray was 6 g / m ² per side. In this way, a prepreg having a carbon fiber areal weight of 190 g / m ² and a carbon fiber content of 64.8% was obtained.

(E) Preparation of Hardened Plate The prepreg prepared in (d) was laminated in the composition of (+ _45/0 / -45 / 90) _2S and (+ 45/0 / -45 / 90) _3S . This was cured in an autoclave at a temperature of 180 ° C. and a pressure of 6 kgf / cm ² for 2 hours.

(F) Measurement of compressive strength (+ 45/0 / -45 / 90) A _2S hardened plate was cut into a rectangle with 12 inches in the 0 ° direction and 1.5 inches in the 90 ° direction. A circular hole with a diameter of 0.25 inch is drilled to form a perforated plate, and the compressive strength at room temperature (24 ° C) and the compressive strength at high temperature and high humidity (measured at 82 ° C after dipping in hot water at 71 ° C for 2 weeks) are installed. It was measured using a Ron 1128 type tester. The results are as follows.

Room temperature compressive strength: 44.4ksi Compressive strength at high temperature and high humidity: 39.0ksi Furthermore, a cured plate of (+ 45/0 / -45 / 90) _3S configuration is
A 6-inch, 90-degree 4-inch rectangle was cut out, and a 270 inch-pound falling weight impact was applied to the center, and the compressive strength after impact was measured. The results are as follows.

Compressive strength after impact: 43.4 ksi (Example 2) (a) Preparation of prepreg The primary resin prepared in (a) of Example 1 was coated on release paper with a reverse roll coater at an application amount of 45.7 g / the resin film was prepared by coating so as to be m ^2.

Carbon fibers (T800H, manufactured by Toray Industries, Inc.) aligned in one direction were sandwiched from both sides with the primary resin film and heated and pressed to impregnate the resin. Amorphous polyetherimide "Ultem" 1010 short fibers on both sides (fineness 1.4 denier, fiber length 1 mm, Nitto Boseki Co., Ltd.)
Cut long fibers, glass transition temperature 214 ℃)
Was sprayed. The amount of spray was 6 g / m ² per side. In this way, carbon fiber areal weight 190g / m ² , carbon fiber content 64.8%
I got a prepreg of.

(B) Preparation of Hardened Plate The prepreg prepared in (a) was laminated in the composition of (+ _45/0 / -45 / 90) _2S and (+ 45/0 / -45 / 90) _3S . This was cured in an autoclave at a temperature of 180 ° C. and a pressure of 6 kgf / cm ² for 2 hours.

(C) Measurement of compressive strength (+ 45/0 / -45 / 90) A _2S hardened plate was cut into a rectangle with 12 inches in the 0 ° direction and 1.5 inches in the 90 ° direction. A circular hole with a diameter of 0.25 inch is drilled to form a perforated plate, and the compressive strength at room temperature (24 ° C) and the compressive strength at high temperature and high humidity (measured at 82 ° C after soaking in hot water at 71 ° C for 2 weeks) It was measured using a Ron 1128 type tester. The results are as follows.

Room temperature compressive strength: 44.2ksi Compressive strength at high temperature and high humidity: 38.7ksi Furthermore, a (+ 45/0 / -45 / 90) _3S hardened plate is
A 6-inch, 90-degree 4-inch rectangle was cut out, and a 270 inch-pound falling weight impact was applied to the center, and the compressive strength after impact was measured. The results are as follows.

Compressive strength after impact: 43.9 ksi (Example 3) (a) Fabrication of non-woven fabric Amorphous polyamide “Grillamide” TR-55 (EMSER WE) discharged from a die with one orifice
Fibers of RKE polyamide) were stretched and dispersed by using an aspirator having an impact plate at the tip on a wire mesh and compressed air for repair. The fiber sheet repaired on the wire mesh was heat-bonded using a heat press machine to prepare a non-woven fabric of "Grillamide" TR-55. The glass transition temperature of the non-woven fabric was 157 ° C. The basis weight of the fiber was 6.5 g / m ² .

(B) Preparation of prepreg The primary resin prepared in Example (a) was coated on release paper using a reverse roll coater to a coating amount of 45.2 g / m ² to prepare a resin film.

Carbon fibers (T800H, manufactured by Toray Industries, Inc.) aligned in one direction were sandwiched from both sides with the primary resin film, and heated and pressed to impregnate the resin. Further, the non-woven fabric prepared in (a) was attached to both sides of the non-woven fabric, and the non-woven fabric was impregnated with resin by heating and pressing. In this way carbon fiber areal weight
A prepreg having 190 g / m ² and a carbon fiber content of 64.8% was obtained.

(C) Preparation of Hardened Plate The prepreg prepared in (b) was laminated in the composition of (+ _45/0 / -45 / 90) _2S and (+ 45/0 / -45 / 90) _3S . This was cured in an autoclave at a temperature of 180 ° C. and a pressure of 6 kgf / cm ² for 2 hours.

(D) Measurement of compressive strength (+ 45/0 / -45 / 90) A _2S hardened plate was cut into a rectangle with 12 inches in the 0 ° direction and 1.5 inches in the 90 ° direction. A circular hole with a diameter of 0.25 inch is drilled to form a perforated plate, and the compressive strength at room temperature (24 ° C) and the compressive strength at high temperature and high humidity (measured at 82 ° C after dipping in hot water at 71 ° C for 2 weeks) are installed. It was measured using a Ron 1128 type tester. The results are as follows.

Room temperature compressive strength: 43.9ksi Compressive strength at high temperature and high humidity: 38.0ksi Furthermore, a cured plate of (+ 45/0 / -45 / 90) _3S configuration is
A 6-inch, 90-degree 4-inch rectangle was cut out, and a 270 inch-pound falling weight impact was applied to the center, and the compressive strength after impact was measured. The results are as follows.

Compressive strength after impact: 42.7 ksi (Example 4) (a) Preparation of knitting Using a one-piece tubular knitting machine (MODEL CR-B manufactured by Koike Machinery Co., Ltd.), a crystalline polyamide-nylon 66 multifilament ( A knitted fabric (flat knitting) of 15 denier, 7 filaments, manufactured by Toray Industries, Inc., melting point 251 ° C) was prepared. The fiber basis weight of the knit was 7.0 g / m ² .

(B) Preparation of prepreg The primary resin prepared in Example (a) was coated on a release paper using a reverse roll coater so that the coating amount was 44.7 g / m ² to prepare a resin film.

Carbon fibers (T800H, manufactured by Toray Industries, Inc.) aligned in one direction were sandwiched from both sides with the primary resin film and heated and pressed to impregnate the resin. Further, the knitted fabric produced in (a) was attached to both sides thereof. In this way, a prepreg having a carbon fiber areal weight of 190 g / m ² and a carbon fiber content of 64.8% was obtained.

(C) Preparation of Hardened Plate The prepreg prepared in (b) was laminated in the composition of (+ _45/0 / -45 / 90) _2S and (+ 45/0 / -45 / 90) _3S . This was cured in an autoclave at a temperature of 180 ° C. and a pressure of 6 kgf / cm ² for 2 hours.

(D) Measurement of compressive strength (+ 45/0 / -45 / 90) A _2S hardened plate was cut into a rectangle with 12 inches in the 0 ° direction and 1.5 inches in the 90 ° direction. A circular hole with a diameter of 0.25 inch is drilled to form a perforated plate, and the compressive strength at room temperature (24 ° C) and the compressive strength at high temperature and high humidity (measured at 82 ° C after soaking in hot water at 71 ° C for 2 weeks) It was measured using a Ron 1128 type tester. The results are as follows.

Room temperature compressive strength: 44.0ksi High temperature and high humidity compressive strength: 38.3ksi In addition, a cured plate of (+ 45/0 / -45 / 90) _3S configuration is
A 6-inch, 90-degree 4-inch rectangle was cut out, and a 270 inch-pound falling weight impact was applied to the center, and the compressive strength after impact was measured. The results are as follows.

Compressive strength after impact: 42.2 ksi (Example 5) (a) Preparation of prepreg The primary resin prepared in (a) of Example 1 was coated on a release paper with a reverse roll coater in an amount of 43.7 g / the resin film was prepared by coating so as to be m ^2.

Carbon fibers (T800H, manufactured by Toray Industries, Inc.) aligned in one direction were sandwiched from both sides with the primary resin film and heated and pressed to impregnate the resin. Further, on both sides thereof, long fibers of amorphous polyetherimide "Ultem" 1010 (fineness: 270 denier, number of filaments: 10, filaments manufactured by Nitto Boseki Co., Ltd. were separated, glass transition temperature: 21).
4 ° C.) was wound in parallel with the reinforcing fiber with a drum winder at a pitch of 4 mm so that the basis weight was 8 g / m ² per side. In this way, a prepreg having a carbon fiber areal weight of 190 g / m ² and a carbon fiber content of 64.8% was obtained.

(B) Preparation of Hardened Plate The prepreg prepared in (a) was laminated in the composition of (+ _45/0 / -45 / 90) _2S and (+ 45/0 / -45 / 90) _3S . This was cured in an autoclave at a temperature of 180 ° C. and a pressure of 6 kgf / cm ² for 2 hours.

(C) Measurement of compressive strength (+ 45/0 / -45 / 90) A _2S hardened plate was cut into a rectangle with 12 inches in the 0 ° direction and 1.5 inches in the 90 ° direction. A circular hole with a diameter of 0.25 inch is drilled to form a perforated plate, and the compressive strength at room temperature (24 ° C) and the compressive strength at high temperature and high humidity (measured at 82 ° C after dipping in hot water at 71 ° C for 2 weeks) are installed. It was measured using a Ron 1128 type tester. The results are as follows.

Room temperature compressive strength: 43.9ksi High temperature and high humidity compressive strength: 38.7ksi Further, a cured plate of (+ 45/0 / -45 / 90) _3S configuration is
A 6-inch, 90-degree 4-inch rectangle was cut out, and a 270 inch-pound falling weight impact was applied to the center, and the compressive strength after impact was measured. The results are as follows.

Compressive strength after impact: 38.6 ksi (Example 6) (a) Preparation of prepreg The primary resin prepared in (a) of Example 1 was coated on release paper with a reverse roll coater at an application amount of 45.3 g / the resin film was prepared by coating so as to be m ^2.

Carbon fibers (T800H, manufactured by Toray Industries, Inc.) aligned in one direction were sandwiched from both sides with the primary resin film and heated and pressed to impregnate the resin. Furthermore, tape-shaped films of polyetherimide "Ultem" on both sides (width 5 mm, thickness 10 micron, Sumitomo Bakelite Co., Ltd.)
Slit film made, glass transition temperature 214
C.) was wound in parallel with the reinforced fiber at a pitch of 10 mm using a drum winder so that the basis weight was 6.4 g / m ² per side. In this way, a prepreg having a carbon fiber areal weight of 190 g / m ² and a carbon fiber content of 64.8% was obtained.

(B) Preparation of Hardened Plate The prepreg prepared in (a) was laminated in the composition of (+ _45/0 / -45 / 90) _2S and (+ 45/0 / -45 / 90) _3S . This was cured in an autoclave at a temperature of 180 ° C. and a pressure of 6 kgf / cm ² for 2 hours.

(C) Measurement of compressive strength (+ 45/0 / -45 / 90) A _2S hardened plate was cut into a rectangle of 12 inches in the 0 ° direction and 1.5 inches in the 90 ° direction, and cut in the center. A circular hole with a diameter of 0.25 inch is drilled to form a perforated plate, and the compressive strength at room temperature (24 ° C) and the compressive strength at high temperature and high humidity (measured at 82 ° C after dipping in hot water at 71 ° C for 2 weeks) are installed. It was measured using a Ron 1128 type tester. The results are as follows.

Room temperature compressive strength: 44.5ksi High temperature and high humidity compressive strength: 39.1ksi Furthermore, a cured plate of (+ 45/0 / -45 / 90) _3S configuration is
A 6-inch, 90-degree 4-inch rectangle was cut out, and a 270 inch-pound falling weight impact was applied to the center, and the compressive strength after impact was measured. The results are as follows.

Compressive strength after impact: 40.1 ksi (Comparative Example 1) (a) Preparation of prepreg The resin prepared in (a) of Example 1 was coated on release paper with a reverse roll coater at an amount of 51.7 g / m 2. ^A resin film was prepared by coating so as to be ² .

Carbon fibers (T800H, manufactured by Toray Industries, Inc.) aligned in one direction are sandwiched from both sides with the above resin film, and heat and pressure are impregnated with the resin to give a carbon fiber basis weight of 190 g / m 2.
^2. A prepreg with a carbon fiber content of 64.8% was obtained.

(B) Preparation of Hardened Plate The prepreg prepared in (a) was laminated in the composition of (+ _45/0 / -45 / 90) _2S and (+ 45/0 / -45 / 90) _3S . These were cured under the same conditions as in Example 1.

(C) Measurement of compressive strength (+ 45/0 / -45 / 90) A hardened plate having a composition of _2S was processed into a perforated plate in the same manner as in Example 1, and the compressive strength at room temperature and high temperature and high humidity were applied. The compressive strength was measured. The results were as follows. Room temperature compressive strength: 45.2ksi High temperature and high humidity compressive strength: 39.0ksi In addition, (+ 45/0 / -45 / 90) _3S hardened plate is
A 6-inch, 90-degree 4-inch rectangle was cut out, and a 270 inch-pound falling weight impact was applied to the center, and the compressive strength after impact was measured. The results were as follows.

Compressive strength after impact: 18.2 ksi (Comparative example 2) (a) Preparation of resin composition The following raw materials were kneaded to obtain an epoxy resin composition.

(1) Tetraglycidyldiaminodiphenylmethane (Epicoat 604, manufactured by Yuka Shell Epoxy Co., Ltd.) 40.0 parts (2) Bisphenol A type epoxy resin (Epicoat 825, manufactured by Yuka Shell Epoxy Co., Ltd.) 20. 0 parts (3) Bisphenol F type epoxy resin (Epicoat 830, manufactured by Yuka Shell Epoxy Co., Ltd.) 20.0 parts (4) Polyether sulfone (PES5003P, manufactured by Sumitomo Chemical Co., Ltd.) 18.0 parts (5) ) 3,3'-Diaminodiphenylsulfone (Sumicure S, manufactured by Sumitomo Chemical Co., Ltd.) 43.0 parts (b) Physical properties of cured resin The resin prepared in (a) was cured at 180 ° C for 2 hours. A plate having a thickness of 2 mm was prepared from the cured resin. Flexural modulus measurement is 2m
A m-thick plate was cut into a width of 10 mm and a span of 32 mm was used.

The room temperature flexural modulus of the cured product was 350 kgf / mm ²
The bending elastic modulus measured at 82 ° C. after absorbing boiling water for 20 hours was 270 J / m ² .

(C) Preparation of prepreg A resin film was prepared by applying the primary resin prepared in (a) onto release paper using a reverse roll coater at a coating amount of 45.7 g / m ² .

Carbon fibers (T800H, manufactured by Toray Industries, Inc.) aligned in one direction were sandwiched from both sides with the primary resin film, and heated and pressed to impregnate the resin. Further, particles of the polyetherimide "Ultem" 1000 prepared in (a) of Example 1 were sprinkled on both sides thereof. The amount of spray was 6 g / m ² per side. In this way carbon fiber areal weight 190g /
A prepreg having m ² and a carbon fiber content of 64.8% was obtained.

(D) Preparation of Hardened Plate The prepreg prepared in (c) was laminated in the composition of (+ _45/0 / -45 / 90) _2S and (+ 45/0 / -45 / 90) _3S . This was cured in an autoclave at a temperature of 180 ° C. and a pressure of 6 kgf / cm ² for 2 hours.

(E) Measurement of compressive strength (+ 45/0 / -45 / 90) A _2S hardened plate was cut into a rectangle of 12 inches in the 0 ° direction and 1.5 inches in the 90 ° direction, and cut in the center. A circular hole with a diameter of 0.25 inch is drilled to form a perforated plate, and the compressive strength at room temperature (24 ° C) and the compressive strength at high temperature and high humidity (measured at 82 ° C after dipping in hot water at 71 ° C for 2 weeks) are installed. It was measured using a Ron 1128 type tester. The results are as follows.

Room temperature compressive strength: 37.8 ksi High temperature and high humidity compressive strength: 33.0 ksi Further, a cured plate of (+ 45/0 / -45 / 90) _3S has a 0 ° direction of 6 inches and a 90 ° direction of 4 inches. Cut it out to a rectangle of inches,
A falling weight impact of 270 inch-pounds was applied to the center, and the compressive strength after impact was measured. The results are as follows.

Compressive strength after impact: 45.9ksi

[0094]

As described above, as is clear from the examples, the fiber-reinforced composite material obtained from the prepreg of the present invention has a mechanical property of compression system, especially a perforated plate having high temperature and high humidity conditions. Achieving both compression strength and high impact strength. Therefore, the fiber-reinforced composite material obtained by using the prepreg according to the present invention is suitable as a perforated structural material having a bolt hole or the like, and the applicable applications can be greatly expanded.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B29K 105: 00 105: 08 C08L 63:00

Claims (12)

[Claims] 1. A prepreg comprising the following constituent elements (A), (B) and (C), wherein the constituent element (C) is distributed near the surface layer on one side or both sides. (A) Reinforcing fiber (B) Epoxy resin composition having a room temperature flexural modulus of 380 kgf / mm ² or more (C) Thermoplastic resin particles, fibers, or film 2. Boiling water of a cured product of the epoxy resin composition (B)
After absorbing water for 20 hours, the flexural modulus measured at 82 ℃ is 280kgf / mm.
The prepreg according to claim 1, wherein the prepreg is ² or more. 3. The prepreg according to claim 1 or 2, wherein the thermoplastic resin as the constituent element (C) is crystalline and has a melting point of 120 ° C or higher. 4. The prepreg according to claim 1 or 2, wherein the thermoplastic resin as the constituent element (C) is amorphous and has a glass transition point of 120 ° C. or higher. 5. The thermoplastic resin of component (C) is at least one resin selected from polyamide, polyimide, polyetherimide, polyamideimide, polysulfone, and polyethersulfone. Alternatively, the prepreg according to claim 2. 6. The prepreg according to claim 1, wherein the thermoplastic resin as the constituent element (C) is in the form of short fibers. 7. The prepreg according to claim 1, wherein the thermoplastic resin as the constituent element (C) is in the form of long fibers. 8. The prepreg according to claim 1, wherein the thermoplastic resin as the constituent element (C) is in the form of a non-woven fabric. 9. The prepreg according to any one of claims 1 to 5, wherein the thermoplastic resin as the constituent element (C) has a knitted form. 10. The composition according to claim 1, wherein the amount of the component (C) is 4 to 15 g / m ² per surface with respect to the surface on which (C) is present. Prepreg. 11. The prepreg according to claim 1, wherein the component (B) contains 3,3′-diaminodiphenyl sulfone as a curing agent. 12. A fiber-reinforced composite material obtained by curing the prepreg according to claim 1.