JPH04140127A - Manufacture of composite material - Google Patents

Abstract

PURPOSE:To manufacture a composite material in the nature of high elasticity, low thermal expansion and having strength in its right angle direction by laminating a thin prepreg raw material used of pitch carbon fiber having a specific elasticity modulus and thermal expansion coefficient such that the fiber comes to be a specific angle, and molding it thereafter. CONSTITUTION:A thin prepreg raw material of 0.03-0.1mm/sheet used of pitch carbon fiber having an elasticity modulus E:70 tom/mm<2> or above and thermal expansion coefficient alpha:-1.4X10<-6>/ deg.C or below is laminated at the wall thickness of 1mm or below in order that the fiber direction of the prepreg raw material becomes 0 and 90, and molded thereafter. By employing the pitch carbon fiber, a mold material can be obtained that has high elasticity and low thermal expansion. Through allowing the prepreg raw material to be thin wall thickness, the mold material can be reduced in its wall thickness and weight, so that the number of lamination thereof can be increased and the lamination arrangement thereof can also be improved in its degree of freedom. Furthermore, by lamination-arranging the fiber in the direction of 0 and 90 deg., a mold material can be obtained which has an ability of high elasticity and low thermal expansion and strength even in the 90 deg..

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a composite material with high elasticity, low thermal expansion, and strength in the perpendicular direction. The present invention relates to a method for producing composite materials that can be advantageously applied to the production of shapes for structural members of aerospace equipment, transportation equipment, electrical and electronic parts, sports and leisure goods, etc.

[Conventional technology]

Conventionally, high modulus PAN (polyacrylonitrile) carbon fiber (modulus of elasticity E≦50 t
on/mm2, thermal expansion coefficient α≧-0,7×10-'/l)
prepreg material using (thickness: 0, 14 mm/piece)
The elastic modulus E 20 to
Angle and tube shapes having a thermal expansion coefficient of 1×10 −′/ or more and a thermal expansion coefficient of 1×10 −′/ or more were obtained by autoclave molding.

[Problem to be solved by the invention]

Among high-performance composite molding materials using conventional technology, (1) PAN
For carbon fibers, the elastic modulus E is Max.

50 ton/mm", thermal expansion coefficient α is min, -〇,
7 X10-'/l', and there is a limit to high elasticity and low thermal expansion.

(2) Prepreg material has a conventional wall thickness of ~0.14 m
m/sheet is standard, which is too thick to make thin-walled shapes, and there is little lamination flexibility.

(3) In order to achieve high elasticity and low thermal expansion performance within a limited number of laminated layers, the laminated layers are mainly 0° and the strength in the right angle direction is weak.

(4) In order to produce high-performance composite materials, autoclave molding is used to easily obtain high-quality molded products, which is time-consuming and costly.

There are other problems.

In view of the above-mentioned state of the art, the present invention aims to solve the above-mentioned problems and provide a method for manufacturing a composite material having high elasticity, low thermal expansion, and strength in the right angle direction.

[Means to solve the problem]

The present invention is a thin prepreg of 0.03 to 0.1 mm/sheet using pitch-based carbon fiber having an elastic modulus E: 70 ton/mm2 or more and a thermal expansion coefficient α knee 1.4 x 10-6/l: or less. The material is laminated appropriately so that the fiber direction of the prepreg material is 0° and 90° with a wall thickness of 1 mm or less, and then molded.It has high elasticity, low thermal expansion, and strength in the right angle direction. This is a method for manufacturing composite materials.

In the present invention, the thin prepreg materials are suitably laminated so that the fiber direction thereof is 90° with respect to Oo, and then a molding method using a wrapping tape is employed in addition to autoclave molding.

[Effect]

Elastic modulus E: 70 ton/mm2 or more, thermal expansion coefficient α
By using pitch-based carbon fibers with a particle diameter of 1.4 x 10-6/°C or less, it is possible to create a molding material with higher elasticity and lower thermal expansion than a molding material using PAN-based carbon fibers. Furthermore, by making the prepreg material thinner, the mold material can be made thinner and lighter. Furthermore, the number of layers of prepreg material can be increased with the limited wall thickness of the molding material, increasing the degree of freedom in layer arrangement.
By optimizing the laminated arrangement of fibers in the 0° and 90° directions, taking into consideration the balance between elastic modulus and thermal expansion, we have created a molding material that has high elasticity and low thermal expansion performance, and is also strong in the 90° direction. is obtained.

Further, according to the present invention, a high-performance mold material can be obtained by molding the pitch-based carbon fiber reinforced composite tube using a wrapping tape, which is easy to mold, in addition to autoclave molding. For example, a thin-walled tube can be obtained by laminating two layers of prepreg into a tube mold without disturbing the fiber arrangement, wrapping a wrapping tape thereon and curing it in an oven.

Embodiments of the present invention will be described below with reference to the drawings.

[Example 1] Fig. 1 shows an example of manufacturing an angle-shaped material, in which highly elastic pitch-based carbon fiber l is impregnated with ebo beef resin and has a hardened thickness of 0.
Thin prepreg 2 with a thickness of 0.06 mm/sheet was used. Table 1 shows the properties of the two types of prepreg materials actually used.

Since Prepreg 2 is made of highly elastic pitch-based carbon fiber and has a thin wall, it is relatively hard and tends to come apart easily, resulting in poor molding workability.
Two layers of prepreg 3 arranged in the 0° direction and prepreg 4 arranged in the 90° direction were laminated without disturbing the fiber arrangement.

Prepreg thickness is 0.06m for a 1mm plate thickness
The number of laminated sheets is 16 layers, and these 16 layers are used to optimize the 0°° direction alignment and 90° direction alignment [elastic modulus E as high as possible < (E≧25 ton/ff1m'), thermal expansion coefficient Close to zero < (-1, Ox 10-'/℃≦α〈
0) Arrangement combination (Modulus of elasticity in 0° direction of unidirectional laminate E: 47
0 kgf/mm", thermal expansion coefficient α: 47X 10-6
/t” as the basic data), the 0° direction array can be distributed to 10 layers and the 90° direction array to 6 layers, so the ratio of 90° direction array is 37.5%. As shown, two layers of prepreg are placed in the angle mold 5 at a 90° angle.
The ratio of directional alignment is set to 37.5%, which is optimal for elastic modulus and thermal expansion [0/9 010/90102/9 010],
(0: 0° direction array, 90: 90° direction array, 02
: Two layers in the 0° direction, 16 layers (S hernimetry) were laminated. A corner pad 7 made of silicone rubber or the like was placed on the laminate 6 so that the corners would be dense, and autoclave molding was performed.

The quality of the formed angle profile 8 is shown in Table 2.
There are no defects such as voids, and the elastic modulus is 25 ton/mm.”
We were able to prototype an angle-shaped material with a thermal expansion coefficient of -IXIO-6/°C, high elasticity and low thermal expansion.

[Example 2] Figure 2 shows an example of manufacturing a tube shape material. The same prepreg material as in Figure 1 was used, and prepregs 3
The same lamination structure as shown in Fig. 1 is obtained by stacking two layers of prepregs 4 arranged in a 90° direction [0/9010/90102/9010
1, and were laminated by winding around a tube mold 9 to form 16 layers. A wrapping tape 10 made of polyethylene terephthalate is further wrapped around the entire laminate 6. Oven curing causes the wrapping tape to heat shrink and form a laminate under pressure.

The quality of the molded tube material 11 is also shown in Table 2 above. With a thin wall of 1 mm, there are very few voids of 0.3%, an elastic modulus of 41 ton/mm2, and a thermal expansion coefficient of 0.9 x 10
-6/l: We were able to prototype a high-performance tube material.

〔Effect of the invention〕

According to the present invention, pitch-based carbon fibers with a modulus of elasticity of 70 ton/mm" or more and a coefficient of thermal expansion of -1°4X10-6/°C or less are used, and the thickness of the prepreg is reduced to less than half of that of conventional prepregs. , 03~0.1 mm/sheet of prepreg material, and by optimizing the laminated arrangement of carbon fibers in the 0° and 90° directions, high elasticity (E≧25
ton/mm2), low thermal expansion (α≦-I X 10-
6/F), which also has strength in the right angle direction, and a thin, lightweight, high-performance composite molded material can be obtained. In addition, we applied a molding method using wrapping tape that can be easily molded in a short time and at low molding costs without using expensive autoclave molding, and we stacked two layers without disturbing the fiber arrangement and cured in an oven. By doing so, a high-performance tube material can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an example of manufacturing an angle-shaped material according to a first embodiment of the present invention, and FIG. 2 is an explanatory diagram of an example of manufacturing a tube-shaped material according to a second embodiment of the present invention.

Claims (1)

[Claims] Elastic modulus E: 70 ton/mm^2 or more, thermal expansion coefficient α: -
A thin prepreg material of 0.03 to 0.1 mm/sheet using pitch-based carbon fiber of 1.4 x 10^-^6/℃ or less is prepared with a wall thickness of 1 mm or less and the fiber direction of the prepreg material is 0.
A method for producing a composite material having high elasticity, low thermal expansion, and strength in the perpendicular direction, the method comprising laminating layers at an angle of 90° and then molding.