JPH07214551A - Carbon fiber reinforced resin composite material and prepreg - Google Patents

Abstract

PURPOSE:To obtain a carbon fiber-reinforced resin composite material which is excellent in impact resistance characteristic by reinforcing the composite material with carbon fiber wherein specific gravity is a specific value or lower, tensil elastic modulus is a specific value or higher, tensil strength is a specific value or higher, and peel strength at end of plate is a specific value or higher. CONSTITUTION:For carbon fiber composing carbon fiber reinforced resin composite material or prepreg, specific gravity is 1.75 or lower, tensile elastic modulus and tensile strength which are measured by a strand tensile test are respectively 29tf/mm<2> or higher and 500kgf/mm<2>, and peel strength at end of plate measured by a composite test is 22kgf/mm<2> or higher. For carbon fiber of which specific gravity is larger than 1.75, neight reducing effect is small. Further for carbon fiber wherein tensile elastic modulus is under 29tf/mm<2>, and tensile strength is under 500kg/mm<2>, impact resistance is low, and besides thick composite material is necessarily produced in order to develop a specific characteristic. Then, merits by the weight-reduction are decreased. Further, when peel strength at end of plate is under 22kgf/mm<2>, the maximum load is decreased because of ply separation at impact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon fiber reinforced resin composite material and a prepreg which is an intermediate base material thereof, and particularly to a carbon fiber reinforced resin composite material having high impact resistance and a prepreg which is an intermediate base material thereof.

[0002]

2. Description of the Related Art Carbon fiber reinforced resin composite materials are used for sports,
It is widely used in aerospace, but in actual applications, not only static characteristics but also dynamic characteristics such as impact are important. Conventionally, the relationship between the impact resistance characteristics of the carbon fiber composite material and the characteristics of the carbon fibers constituting the carbon fiber reinforced resin composite material was not clear, and there was no carbon fiber reinforced resin composite material having sufficiently high impact resistance.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, namely, to provide a carbon fiber reinforced resin composite material excellent in impact resistance and a carbon fiber reinforced resin prepreg which is an intermediate base material thereof. To provide.

[0004]

In order to solve the above problems, the carbon fiber reinforced resin composite material of the present invention has the following constitution. That is, specific gravity of 1.75 or less, a tensile modulus of 29 tf / mm ² or more, a tensile strength of 500 kgf / mm ² or more, plate end peel strength and wherein the reinforced with 22 kgf / mm ² or more carbon fiber It is a carbon fiber reinforced resin composite material.

The carbon fiber reinforced resin prepreg of the present invention has the following constitution. That is, the specific gravity is 1.75 or less, the tensile elastic modulus is 29 tf / mm ² or more, and the tensile strength is 500.
kgf / mm ² or more, a carbon fiber-reinforced resin prepreg, characterized in that the plate end peel strength is reinforced with 22 kgf / mm ² or more carbon fibers.

The carbon fiber reinforced resin composite material and prepreg of the present invention will be described in detail. The carbon fiber constituting the carbon fiber-reinforced resin composite material or prepreg of the present invention has a specific gravity of 1.75 or less, and a tensile modulus and a strength measured by a strand tensile test of 29 tf / mm, respectively.
Edge Delamination of ² or more and 500 kgf / mm ² or more and measured by composite test
Strength (hereinafter abbreviated as EDS) is 22 kgf / mm ² or more.

Carbon fibers having a specific gravity of more than 1.75 have a small weight-reducing effect, and are preferably 1.74 or less, more preferably 1.73 or less. Tensile elastic modulus is 29 tf / mm ²
If it is less than 500 kgf / mm ² , the impact resistance is low, and it is necessary to make a thick composite material in order to express the desired characteristics, which is not preferable because the merit of weight reduction is small. The elastic modulus is more preferably 29.5 tf / mm ²
As described above, more preferably 30 tf / mm ² or more, and the tensile strength is more preferably 520 kgf / mm ² or more, and further preferably 550 kgf / mm ² or more, which is a great advantage for weight reduction.

E measured by the composite test
If the DS is less than 22 kgf / mm ^2, it is not preferable because the maximum load becomes low due to delamination during impact. It is more preferably 23 kgf / mm ² or more, still more preferably 24 kgf / mm ² or more.

That is, the carbon fiber used in the present invention is an index of the tensile strength, the elastic modulus, and the adhesion with the resin EDS.
The carbon fiber reinforced resin composite material has excellent impact characteristics as a total effect of these characteristics.

The carbon fiber used in the present invention can be obtained as follows, but is not limited thereto.

As the carbon fiber of the present invention, known polyacrylonitrile (PAN) -based, pitch-based, vapor-grown carbon fibers can be used, but PAN is easy to obtain high-strength yarn.
Carbon-based fibers are preferred. The case of PAN-based carbon fiber will be described in detail below as an example.

As the spinning method, a wet method, a dry method, a dry method or the like can be adopted, but a wet method or a dry method, which can easily obtain a high-strength yarn, is preferable, and a dry-wet spinning method is particularly preferable. P for the spinning solution
A solution or suspension of a homopolymer or copolymer of AN can be used. Coagulation, washing with water, drawing, and application of an oiling agent to form a precursor raw yarn, which is further flameproofed, carbonized, and graphitized if necessary.

As for the carbonization or graphitization condition, the maximum temperature in an inert atmosphere is 140 in order to obtain the carbon fiber of the present invention.
The temperature is 0 ° C or higher, preferably 1600 ° C or higher. The higher the firing temperature is, the higher the elastic modulus is, but the tensile strength and the adhesive strength with the resin are lowered, and the specific gravity is increased, so that it is preferable to optimize the firing temperature, and it is preferably 1400 ° C or higher and 2200 ° C or lower, more preferably 1600 ° C or higher and 2000. ℃ or less is good. Further, it is preferable to combine stretching in order to improve tensile strength and elastic modulus at the same firing temperature. In order to improve the strength and the elastic modulus, carbon fibers having a fineness are preferable, and the single fiber diameter of the carbon fibers is 7.5 μm or less, preferably 6.5 μm or less, and more preferably 5.5 μm or less.

The carbon fiber obtained is further subjected to surface treatment and sizing treatment to become carbon fiber. As the electrolyte used in the electrolytic treatment, a solution of an acid such as sulfuric acid or nitric acid, an alkali such as sodium hydroxide, ammonium carbonate or tetraethylammonium hydroxide, and a salt thereof, preferably an aqueous solution is used. In the case of carbon fiber obtained by dry-wet spinning, an aqueous solution of alkali or salt is preferable. As the electrolyte, it is effective to allow a basic amine compound or an ammonium salt to be present. For example, ammonium carbonate, ammonium hydrogen carbonate,
Ammonium carbonate, ammonia, triethylamine, cyclohexylamine, ammonium nitrate, ammonium sulfate, etc., or a mixture thereof can be used. The pH of the electrolytic solution is more preferably 8 or higher. If the pH is less than 8, the graphite oxide produced by electrolytic oxidation is less dissolved and the adhesion to the resin may be reduced.

The amount of electricity used in the electrolytic treatment depends on the elastic modulus of the carbon fiber used, and in the case of a high elastic modulus carbon fiber, energy for destroying the developed graphite structure on the surface is required, and thus a high amount of electricity is required. Become. However, if a large amount of electricity is passed at once, the voltage will increase, which is a safety issue and
There is a problem that defects are likely to occur in the carbon fiber. Therefore, it is necessary to reduce the processing amount per tank and increase the number of processing tanks. Specifically, 1 g of carbon fiber and the amount of electricity per tank is 2 coulomb / g · tank or more 100 coulomb /
g · tank or less is preferable, and 2 coulomb / g · tank or more and 80 coulomb / g · tank or less is more preferable. 2 coulomb / g
If it is less than the number of tanks, the crystallinity of the surface layer does not sufficiently decrease, and the number of processing tanks needs to be increased, resulting in deterioration of productivity. on the other hand,
When it exceeds 100 coulomb / g · tank, the strength of the carbon fiber substrate is greatly reduced. Further, from the viewpoint of maintaining the decrease in crystallinity within an appropriate range, the total amount of electricity during energization treatment is 2 coulomb / g or more and 1000 coulomb / g or less, and further 2 coulomb / g or less.
It is preferably 0 coulomb / g or more and 500 coulomb / g or less. The processing time is preferably several seconds to ten minutes, more preferably about 10 seconds to 2 minutes.

Further, in the step of washing with water and drying after the electrolytic treatment, if the drying temperature is too high, the functional groups existing on the outermost surface of the carbon fiber are likely to disappear by thermal decomposition. Therefore, it is desirable to dry at the lowest temperature possible,
Specifically, it is desirable that the drying temperature is 250 ° C. or lower, more preferably 210 ° C. or lower.

The surface treated carbon fiber has a surface nitrogen concentration N / C and a surface oxygen concentration O / C of 0.02 or more, which are measured by photoelectron spectroscopy (hereinafter referred to as ESCA).
It is desirably 0.2 or less, preferably 0.03 or more and 0.15 or less. That is, if N / C and O / C are out of the above ranges, the adhesion to the resin may be reduced.

The compound used as the sizing agent is
Epoxy sizing agents are preferable, and aliphatic compounds having a plurality of epoxy groups are particularly preferable. The number of epoxy groups is preferably 2 to 4 in order to effectively bridge the carbon fiber and the matrix resin and suppress the reaction between the sizing agents. Further, the skeleton of the sizing agent does not have a rigid and sterically large compound at the interface between the carbon fiber and the matrix resin, so that the molecular chain is linear and flexible,
And it is desirable that the molecular weight is small. Specifically, the epoxy equivalent is 80 or more and 1000 or less, and further 90 or more and 50.
0 or less is preferable, the molecular weight is 100 or more and 2000 or less,
Furthermore, 200 or more and 1000 or less are preferable. As the compound, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyethylene glycol diglycidyl ethers, polypropylene glycol diglycidyl ethers, polyethylene oxide diglycidyl ethers, polypropylene diglycidyl ethers and the like are effective.

The amount of the sizing agent deposited is 0.01% or more and 5% or less, preferably 0.1% or more and 2% or less, per unit weight of carbon fiber. 0.0
If it is less than 1%, the bridging between the carbon fiber and the matrix resin is insufficient and the effect of improving the adhesive property is small, and if it exceeds 5%, the reaction between the sizing agents is increased, so the carbon fiber /
Polymers of the sizing agent occupy between the matrix resins, which may change the composite characteristics, which is not preferable.

Examples of the solvent used for the sizing agent include water, methanol, ethanol, dimethylformamide, dimethylacetamide, and acetone, but water is preferable from the viewpoint of easy handling and disaster prevention. Therefore, it is preferable to add an emulsifier, a surfactant and the like to the epoxy compound which is insoluble or hardly soluble in water to make it water-dispersible.

The drying temperature in the step of drying after applying the sizing agent is preferably 150 ° C. or higher and 350 ° C. or lower, more preferably 180 ° C. or higher and 250 ° C.
If the temperature is lower than 150 ° C, the solvent of the sizing agent cannot be completely removed, which may adversely affect the adhesive properties of the composite, and the drying time becomes long, which is not industrially practical.
If the temperature is 350 ° C or higher, curing of the sizing agent proceeds,
Since the carbon fiber bundle becomes hard and the spreadability of the bundle deteriorates, it may be impossible to form a good composite.

The carbon fibers thus obtained are combined with a resin by a known method such as a prepreg method or a filament winding method, and then a composite material is obtained through a post-molding curing or heat treatment step.

In the case of the prepreg method, the above-mentioned carbon fiber is impregnated with a resin in the form of unidirectional, woven, yarn or mat to obtain a carbon fiber reinforced resin prepreg, and then the prepreg is laminated or wound. After the shaping step, the carbon fiber reinforced resin composite material is obtained by heat molding by a method such as pressing, autoclaving or lapping molding.

The matrix resin is not particularly limited,
Since the sizing agent compound has an epoxy group, an epoxy resin having a high affinity is preferable, and if the curing temperature is too high, the sizing agent applied to the carbon fiber is likely to be deteriorated or decomposed, resulting in adhesion with the resin. The curing temperature may be 250 ° C or lower, and even 20
Epoxy resins having a temperature of 0 ° C. or lower are preferable. Specifically, the 180 ° C.-curable epoxy resin disclosed in Japanese Patent Publication No. 63-60056 and the 130 ° C.-curable epoxy resin disclosed in Japanese Patent Publication No. 4-80054 are preferably used in the present invention. To be It is more preferable to improve the impact properties of the composite material by using a resin toughened by mixing rubber particles or thermoplastic particles, or by reinforcing the prepreg layers with particles or fibers of a thermoplastic resin.

The impact characteristics of the obtained composite material are measured by a Charpy impact tester, and not only the total absorbed energy but also the instrumented Charpy which is required to determine the absorbed energy from the impact force curve to the maximum load and the maximum load is used. This is very important. In the case of brittle materials such as carbon fiber composite materials, the absorbed energy after the maximum load at which fracture starts becomes an index of easiness of division, but the maximum load or the absorbed energy up to the maximum load is more important in terms of function retention. Can be said. The carbon fiber reinforced resin composite material of the present invention has a high maximum load and a high absorbed energy up to the maximum load. A value obtained by dividing the absorbed energy after the maximum load when the unidirectional flat plate is impact-ruptured by flatwise by the absorbed energy up to the maximum load, the so-called ductility index is preferably 0.1 to 0.8, more preferably 0.2.
Is preferably 0.6 to 0.6, more preferably 0.3 to 0.5. When the ductility index is larger than 0.8, the maximum load is low because the fracture starts due to shearing, and the energy is absorbed as the shear fracture progresses, and the total absorbed energy until the final fracture is high. There is a possibility that the ability to retain functions in practice is low. On the other hand, if the ductility index is less than 0.1, it may result in extremely brittle fracture, and other properties such as tensile strength may decrease.

Although the carbon fiber of the present invention can be used alone, it can be used as a composite material by combining with other carbon fiber or other reinforcing fiber, and it is preferable to optimize it according to the application. It can be applied to sports applications such as golf shafts, tennis rackets, fishing rods, and aerospace applications, but is particularly effective for golf shafts where impact characteristics are important. The golf shaft can be formed by a conventionally known technique such as a lapping method,
Further, in order to maximize the shaft characteristics, it is preferable to optimize the laminated structure or the combination with carbon fibers having other characteristics or other reinforcing fibers.

[0027]

EXAMPLES The present invention will be described in more detail below with reference to examples. The strand tensile elastic modulus and strength and EDS in the present invention were determined by the following methods.

(Strand Tensile Modulus and Strength) JI
It was measured according to the resin impregnated strand test method of SR-7601. As resin prescription, "BAKELITE"
ERL4221 / 3 boron fluoride monoethylamine / acetone = 100/3/4 parts were mixed well and used.

The (EDS) resin was prepared as follows according to Example 1 disclosed in Japanese Examined Patent Publication No. 4-80054. That is, 3.5 kg of Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd.
(35 parts by weight), Yuka Shell Epoxy Epicoat 828
2.5 kg (25 parts by weight), 3.0 kg (30 parts by weight) of Epichron N740 manufactured by Dainippon Ink and Chemicals, 1.5 kg (15 parts by weight) of Epicoat 152 manufactured by Yuka Shell Epoxy and Denka manufactured by Denki Kagaku Kogyo 0.8 kg (3 parts by weight) of formal # 20 and 0.5 kg (5 parts by weight) of dichlorophenyldimethylurea were added and stirred for 30 minutes to obtain a resin composition. A release paper was coated with this to form a resin film.

First, a steel drum having a circumference of about 2.7 m is wound with a resin film obtained by coating a silicon-coated paper with a resin to be combined with carbon fibers, and then the carbon fibers drawn from the creel are traversed on the resin film. After winding and arranging, the fiber is covered again with the above resin film, and the fibers are impregnated with the resin by rotating and pressing with a pressure roll, and the width is 300 mm and the length is 2.
A 7 m unidirectional prepreg is prepared.

At this time, in order to improve the resin impregnation between the fibers, the drum is heated to 60 to 70 ° C., and the fiber areal weight of the prepreg is adjusted by adjusting the rotational speed of the drum and the traverse feed speed. A prepreg having 200 g / m ² and a resin amount of about 35% by weight was prepared.

The prepreg thus produced is cut,
(+ 25 / −25 / + 25 / −25 / 90) _s stacked, and autoclave at 135 ℃, 3kgf / cm ²
It is cured by heating for 2 hours under the thickness of about 2 for EDS measurement.
A mm cured plate was prepared.

The test piece had a width of 25.4 mm and a length of 230 mm, and the measurement was carried out by using an ordinary tensile test jig with a test length of 127.
The strain rate was set to 1 mm / min and the strain rate was measured at 1 mm / min. The peel strength was obtained from the load when peeling started on the side surface of the test piece.

Further, the specific gravity of the carbon fiber described in this example, O / C and N / C measured by ESCA, and instrumented Charpy impact energy were determined as follows.

(Specific gravity) The specific gravity was measured by the float and sink method of JIS R-7601.

(O / C and N / C) Surface oxygen concentration O / C or surface nitrogen concentration N / C measured by ESCA
Means a value obtained by the following procedure. First, a carbon fiber bundle from which a sizing agent and the like has been removed with a solvent is cut and spread on a stainless steel sample support table and arranged, and then a photoelectron escape angle is set to 90 °, and MgKα _1,2 is used as an X-ray source. The inside of the sample chamber is kept at a vacuum of 1 × 10 ⁻⁸ Torr. To correct the peak due to charging during measurement, first use C _1S
Set the binding energy value BE of the main peak of to 284.6 eV. The C _1S peak area is obtained by drawing a straight base line in the range of 282 to 296 eV. The O _1S peak area is obtained by drawing a straight baseline in the range of 528 to 540 eV, and the N _1S peak area is obtained by drawing a straight baseline in the range of 398 to 410 eV. Here, the surface oxygen concentration O / C is the O _1S peak area and the C _1S
It is the atomic number ratio calculated by dividing the ratio of the peak areas by the sensitivity correction value specific to the device. Note that, for example, when ESCA-750 manufactured by Shimadzu Corporation is used, the sensitivity correction value peculiar to the above apparatus is 2.85. The surface oxygen concentration N / C means the atomic number ratio calculated by dividing the ratio of the N _1S peak area and the C _1S peak area by the sensitivity correction value specific to the apparatus. Note that, for example, when ESCA-750 manufactured by Shimadzu Corporation is used, the sensitivity correction value peculiar to the above apparatus is 1.7.

(Instrumented Charpy Impact Energy) JIS-K-7077 is prepared by using the above-mentioned one-way prepreg.
A test piece is prepared in accordance with the above, and the maximum load, the absorbed energy up to the maximum load, and the absorbed energy after the maximum load are measured using an instrumented Charpy impact tester. The dimensions of the test piece were 6 mm in thickness, 10 mm in width and 60 mm in length, and the distance between spans was 40 mm.

(Example 1) Acrylonitrile (AN) 9
An acrylic fiber having a single fiber denier of 0.6 d and a filament number of 18,000 was obtained by a dry-wet spinning method using a copolymer of 9.7 mol% and methacrylic acid 0.3 mol%. The obtained fiber bundle is heated in the air of 240 to 280 ° C. at a draw ratio of 1.03 to be converted into flame resistant fiber, and then the temperature rising rate in a temperature range of 300 to 500 ° C. in a nitrogen atmosphere is 180 ° C. / Min and 10% stretching and then 1
It was baked up to 700 ° C. An aqueous solution of ammonium hydrogencarbonate having a concentration of 0.2 mol / l was used as an electrolytic solution, and the amount of electricity supplied per tank was 10 coulomb / g · tank. Processed. At that time, the electrolytic solution turned black. The electrolytically treated carbon fiber was subsequently washed with water and dried in heated air at 150 ° C. Next, a sizing agent prepared by adding 5% of a nonionic emulsifier to glycerol triglycidyl ether is diluted with water so that the content of the component is 1% by weight to prepare a sizing agent mother liquor. And was dried at 180 ° C. The adhered amount was 0.4%.

The specific gravity of the carbon fiber thus obtained was 1.73, and the strand tensile strength and elastic modulus were 570 kgf / mm ² and 31 tf / mm ² , respectively. O / C and N
/ C was 0.09 and 0.03, respectively. Also E
The DS was 25 kgf / mm ² .

Further, FIG. 1 shows a load-time diagram when the Charpy impact characteristics of the unidirectional material were measured. The maximum load is as high as 5.5 kN, and the absorbed energy up to the maximum load is 6
It was as large as 6 kJ / m ² . The ductility index was 0.34. 20 golf shafts were made using this material,
A robot actual hitting test was conducted under the conditions of a head speed of 50 m / sec and a high heel hit, and as a result, none of them was damaged even after 100 times of actual hitting.

(Comparative Example 1) Using carbon fibers obtained by spinning and firing in the same manner as in Example 1, the concentration was 0.1 mol / l.
The sulfuric acid aqueous solution was used as an electrolytic solution, and the amount of electricity supplied was set to 10 coulomb / g. The electrolytically treated carbon fiber was subsequently washed with water and dried in heated air at 150 ° C.

Next, a sizing agent prepared by adding 5% of a nonionic emulsifier to Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd. was diluted with water so that the content of the components was 1% by weight to prepare a sizing agent mother liquor and dipping. A sizing agent was applied to the carbon fiber by the method and dried at 180 ° C. The adhered amount was 0.5%.

The specific gravity of the carbon fiber thus obtained was 1.73, and the strand tensile strength and elastic modulus were 560 kgf / mm ² and 31 tf / mm ² , respectively. O / C and N
/ C was 0.12 and 0.01, respectively. Also E
The DS was 16 kgf / mm ² .

Further, FIG. 2 shows a load-time diagram when the Charpy impact characteristics of the unidirectional material were measured. Maximum load is as low as 4.3 kN, and absorbed energy up to maximum load is 4
It was as small as 6 kJ / m ² . The ductility index was 0.96. 20 golf shafts were made using this material,
When a robot actual hitting test was conducted in the same manner as in Example 1, only 4 pieces were not damaged after 100 times of actual hitting.

Comparative Example 2 Acrylonitrile (AN) 9
Using a copolymer of 9.7 mol% and methacrylic acid 0.3 mol%, a single fiber denier of 0.1% was obtained by a wet spinning method.
An acrylic fiber having 6d and 18,000 filaments was obtained. Firing the obtained fiber bundle in the same manner as in Example 1,
Carbon fiber was used. The obtained carbon fiber has a concentration of 0.1 mol /
1 sulfuric acid aqueous solution was used as an electrolytic solution, and the amount of electricity supplied was set to 40 coulomb / g. The electrolytically treated carbon fiber was subsequently washed with water and dried in heated air at 150 ° C. Next, a sizing agent prepared by adding 5% of a nonionic emulsifier to glycerol triglycidyl ether,
The sizing agent mother liquor was prepared by diluting with water so that the components would be 1% by weight, the sizing agent was applied to the carbon fibers by the dipping method, and the sizing agent was dried at 180 ° C. Adhesion amount is 0.4%
Met.

The specific gravity of the carbon fiber thus obtained was 1.73, and the strand tensile strength and elastic modulus were 450 kgf / mm ² and 31 tf / mm ² , respectively. O / C and N
/ C was 0.16 and 0.01, respectively. Also E
The DS was 22 kgf / mm ² . Further, FIG. 3 shows a load-time diagram when the Charpy impact characteristics of the unidirectional material were measured. The maximum load was as low as 4.1 kN, and the absorbed energy up to the maximum load was as small as 45 kJ / m ² . The ductility index was 0.17. Twenty golf shafts were produced using this material, and a robot actual hitting test was conducted in the same manner as in Example 1. As a result, only two golf shafts were not damaged after 100 actual hits.

[0047]

INDUSTRIAL APPLICABILITY According to the present invention, carbon fibers having excellent impact resistance characteristics suitable for golf shafts, tennis rackets, fishing rods and other sports applications and aerospace applications, particularly for golf shafts where impact characteristics are important. A reinforced resin composite material can be provided.

[Brief description of drawings]

1 shows a load-time diagram in an instrumented Charpy impact test of the composite material obtained in Example 1. FIG.

FIG. 2 shows a load-time diagram in an instrumented Charpy impact test of the composite material obtained in Comparative Example 1.

FIG. 3 shows a load-time diagram in the instrumented Charpy impact test of the composite material obtained in Comparative Example 2.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area B29L 31:52

Claims (3)

[Claims] 1. A specific gravity of 1.75 or less and a tensile elastic modulus of 29 t.
f / mm ² or more, a tensile strength of 500 kgf / mm ² or more, a carbon fiber reinforced resin composite material plate end peel strength and wherein the reinforced with 22 kgf / mm ² or more carbon fibers. 2. The carbon fiber reinforced resin composite material according to claim 1, wherein the carbon fiber reinforced resin composite material is a golf shaft. 3. Specific gravity 1.75 or less, tensile elastic modulus 29 t
f / mm ² or more, a tensile strength of 500 kgf / mm ² or more, a carbon fiber reinforced resin prepreg plate end peel strength and wherein the reinforced with 22 kgf / mm ² or more carbon fibers.