JPH0542233A - Racket frame - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a racket frame which has a significantly improved mechanical strength such as torsional fracture strength and impact resistance, and a feeling during use, and which is aesthetically superior. [Structure] The racket frame is configured by providing an outer shell molding material 102 around a central material 101, and further, as a reinforcing fiber, at least a metal fiber having a phosphate-treated or chromate-treated surface is reinforced. The prepreg layer 1'is at least the outermost layer of the outer shell molding material 102,
Alternatively, between the center material 101 and the outer shell molding material 102, 1
Layers or multiple layers are provided. The metal fiber is selected from titanium fiber, amorphous fiber, steel fiber, stainless fiber, tungsten fiber, aluminum fiber, etc. 1
A species or multiple species are selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame for various rackets, such as a tennis racket or a badminton racket, in which an outer shell molding material is provided around a central material, and more particularly to the outer shell molding material. The present invention relates to a racket frame, characterized in that a fiber reinforced prepreg layer having at least metal fibers as reinforcing fibers is provided as an outer layer. More specifically, in the present invention, the fiber reinforced prepreg layer is formed of a fiber reinforced prepreg characterized in that the surface of the metal fiber as the reinforcing fiber is treated with phosphate or chromate.

[0002]

2. Description of the Related Art Conventionally, for example, a frame for a tennis racket.
As shown in FIG. 2, the frame or the like is composed of a center material 101 and an outer shell molding material 102, but in recent years, it is said that it is lightweight and has high mechanical strength and good vibration damping characteristics. For the reason, as the outer shell molding material 102, a fiber-reinforced composite resin material using carbon fiber or glass fiber as the reinforcing fiber is used.

In such a conventional racket frame, a predetermined number of fiber reinforced prepregs for forming an outer shell molding material 102 are wound around a center material 101 formed of, for example, hard urethane foam and cured. It is produced by

At this time, a plurality of carbon fiber reinforced prepregs or a plurality of carbon fiber reinforced prepregs and glass fibers are used in order to improve elastic modulus, twisting and bending performance, and further to improve vibration damping characteristics. Frequently, the outer shell molding material 102 is constructed as a hybrid structure by stacking it with a reinforced prepreg.

With such a structure, the racket frame can be made lighter, and the repulsive force can be improved, the breakage can be prevented, and the vibration damping characteristics can be increased. On the other hand, recently, the weight can be simply reduced and the mechanical characteristics can be improved. Not only is it required to be increased, but it is also required to improve the feel during use and to be fashionable (designable).

As a result of many research experiments, the inventors of the present invention, for example, in a racket frame composed of a plurality of carbon fiber reinforced resin layers, at least at the outermost layer of the carbon fiber reinforced resin layer, or at the center material and the outer layer. A fiber-reinforced prepreg having one or a plurality of metal fibers such as titanium fibers, stainless fibers, and tungsten fibers as a reinforcing fiber between the shell molding material and one or a plurality of metal fibers as a reinforcing fiber. By providing a prepreg layer formed of a fiber reinforced prepreg having different fibers such as carbon fibers other than metal fibers, the elastic modulus is high even though it is a racket frame made of fiber reinforced composite resin. It was found that a racket frame having an improved feel during use can be provided.

[0007]

However, it is desired to further improve the torsional fracture strength, the impact resistance, and the feel at the time of use of the racket frame produced by using the fiber-reinforced prepreg. There is.

The inventors of the present invention have conducted many research and experiments to improve a fiber reinforced prepreg having at least a metal fiber as the reinforcing fiber, and as a result, the surface of the metal fiber as the reinforcing fiber is treated with phosphate. Alternatively, the chromate treatment strengthens the metal fibers themselves and significantly improves the adhesion between the metal fibers and the matrix resin. The racket frame produced using these fiber reinforced prepregs has torsional fracture strength and impact resistance. It has been found that the properties and the feel during use can be greatly improved.

The present invention has been made based on such a new finding.

Therefore, it is an object of the present invention to provide a racket frame which has a significantly improved mechanical strength such as torsional fracture strength and impact resistance, and a feeling during use, and which is aesthetically superior. Is.

[0011]

The above object is achieved by a racket frame according to the present invention. In summary, the present invention relates to a racket frame in which an outer shell molding is provided around a central material, and a fiber-reinforced prepreg layer having at least metal fibers having a phosphate-treated or chromate-treated surface as reinforcing fibers. Is provided at least in the outermost layer of the outer shell forming material or between the center material and the outer shell forming material. Preferably, a metal salt coating having a coating amount of 0.2 to 10 g / m ² is formed on the surface of the metal fiber by the phosphate treatment, and a coating amount of 0.01 to 0.15 g / m ² is formed by the chromate treatment. A metal salt coating of ² is formed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a racket frame according to the present invention will be described in more detail with reference to the drawings.

In the present embodiment, the racket frame according to the present invention is, as shown in FIG. 1, preferably around a center member 101 formed of hard urethane foam or the like.
It is manufactured by winding a predetermined number of fiber reinforced prepregs for forming the outer shell molding material 102 and curing the prepregs.

Further, according to the present invention, the outer shell molding material 102.
As the outermost layer, a fiber reinforced prepreg layer 1'which will be described in detail later is formed. That is, according to the present invention, a racket frame including the center material 101, the outer shell molding material 102 provided around the center material 101, and the prepreg layer 1 ′ provided as the outermost layer is formed. Although not shown, the prepreg layer 1 ′ can be provided between the center material 101 and the outer shell forming material 102, and further provided between the outermost layer and the center material and the outer shell forming material. , Can be provided at any position. The fiber reinforced prepreg layer 1'may be provided as one layer or as a plurality of layers.

The center material 101 is preferably made of hard urethane foam or the like, and the outer shell molding material 102 is made of, for example, a plurality of carbon fiber reinforced prepregs.
Alternatively, a carbon fiber reinforced prepreg and a glass fiber reinforced prepreg may be superposed on each other to form a hybrid structure.

The carbon fiber reinforced prepreg and glass fiber reinforced prepreg used as the outer shell molding material 102 may be ordinary ones, and carbon fiber (including graphite fiber) and glass fiber are used as the reinforcing fibers, respectively. As the matrix resin, a thermosetting matrix resin such as an epoxy resin, an unsaturated polyester resin, a polyurethane resin, a diallyl phthalate resin, or a phenol resin can be used. Further, a curing agent and other imparting agents such as flexibility imparting agent are appropriately added so that the curing temperature is 50 to 200 ° C.

Next, the fiber-reinforced prepreg layer 1'characteristic of the present invention will be described in more detail. 3 and 4
An example of the fiber reinforced prepreg 1 used for forming the fiber reinforced prepreg layer 1 ′ of the present invention is shown in FIG.

FIG. 3 is a sectional view showing an embodiment of the fiber reinforced prepreg which is a feature of the present invention. In this embodiment, the fiber reinforced prepreg 1 is configured to have reinforcing fibers impregnated with the matrix resin 2. According to the present invention, as the reinforcing fiber, one or more kinds of metal fiber 4 selected from titanium fiber, amorphous fiber, steel fiber, stainless fiber, tungsten fiber, aluminum fiber, etc.
Is used. The metal fiber 4 may have various fiber diameters, such as a small diameter of 5 to 30 μm or a large diameter of 50 to 150 μm.

In the fiber reinforced prepreg 1 of the present invention, as shown in FIG. 4, the reinforcing fiber is selected from the above-mentioned titanium fiber, amorphous fiber, steel fiber, stainless fiber, tungsten fiber, aluminum fiber and the like. In addition to the one or more kinds of metal fibers 4, it is possible to have different kinds of fibers 6 different from these metal fibers 4. The different fibers 6 are selected from inorganic fibers such as carbon fibers, boron fibers, glass fibers, alumina fibers, silicon carbide fibers and silicon nitride fibers, and organic fibers such as aramid fibers, polyarylate fibers and polyethylene fibers.
Seed or multiple species. The heterogeneous fiber 6 also has a small diameter of 5 to 30 μm, or 50 to 150, like the metal fiber 4.
Various fiber diameters can be used, such as those with large diameters of μm.

As the matrix resin 2, a thermosetting matrix resin such as epoxy resin, unsaturated polyester resin, polyurethane resin, diallyl phthalate resin or phenol resin can be used. Further, a curing agent and other imparting agents such as flexibility imparting agent are appropriately added so that the curing temperature is 50 to 200 ° C.

As a preferred example, an epoxy resin is preferable as the matrix resin, and usable epoxy resins include, for example, (1) glycidyl ether type epoxy resins (bisphenol A, F, S type epoxy resin, novolac type epoxy resin). Resin, brominated bisphenol A epoxy resin); (2) cycloaliphatic epoxy resin;
(3) Glycidyl ester-based epoxy resin; (4) Glycidylamine-based epoxy resin; (5) Heterocyclic epoxy resin; and one or more kinds selected from other various epoxy resins, particularly bisphenol A, F, S
Glycidyl amine epoxy resin is preferably used.
As the curing agent, amine-based curing agents such as dicyandiamide (DICY), diaminodiphenylsulfone (DDS), diaminodiphenylmethane (DDM); acid anhydrides such as hexahydrophthalic anhydride (HHP)
A), methylhexahydrophthalic anhydride (MHHPA)
Etc. are used, but amine-based curing agents are particularly preferably used.

The mixing ratio of the reinforcing fiber and the matrix resin 2 in the fiber reinforced prepreg 1 can be adjusted as desired.
Generally, weight% of reinforcing fiber: matrix resin = 30-8
The range of 0:20 to 70 is good, and preferably 40 to 75:
25-60. Also, the thickness T of the fiber reinforced prepreg 1
Is usually 20 to 300 μm.

According to the present invention, the metal fiber 4 used in the fiber reinforced prepreg 1 is previously subjected to a phosphate treatment or a chromate treatment as a chemical conversion treatment.

The inventors of the present invention have sufficiently improved the mechanical strength of the fiber reinforced prepreg 1 by using the metal fiber 4 when manufacturing a racket frame using the fiber reinforced prepreg 1 using the metal fiber 4. To show
We have conducted extensive studies to obtain a racket frame that has significantly improved mechanical strength such as torsional fracture strength and impact resistance, and the feel during use.

As a result, in the conventional fiber reinforced prepreg 1, the adhesiveness between the metal fiber 4 and the matrix resin 2 is low, and therefore the mechanical strength of the fiber reinforced prepreg 1 due to the use of the metal fiber 4 as the reinforcing fiber. The strength improving effect is not sufficiently exerted, and the racket frame obtained by using this fiber reinforced prepreg 1 does not have sufficient mechanical strength improving effects such as torsional fracture strength and impact resistance. It was found that the torsional fracture strength and the impact resistance were not sufficiently improved, and the feel at the time of use, such as shot feeling, was not sufficiently improved.

The present inventors have found that it is extremely effective to pre-treat the metal fiber 4 with phosphate or chromate in order to enhance the adhesion of the metal fiber 4 to the matrix resin 2.

By subjecting the metal fiber 4 to a phosphate treatment or a chromate treatment in advance, a metal salt film is formed on the surface of the metal fiber, and this metal salt film enhances the adhesiveness of the metal fiber 4 with the matrix resin 2. Thereby, the effect of improving the mechanical strength such as the torsional fracture strength and the impact resistance of the racket frame made of the fiber reinforced prepreg 1 using the metal fiber 4 can be sufficiently exerted, and the hit ball at the time of use can be achieved. It was found that the feeling such as feeling can be improved.

As the phosphate treatment, either a zinc phosphate-based treatment or a manganese phosphate-based phosphate treatment can be used. In particular, when the metal fibers 4 are steel fibers or stainless fibers, iron phosphate-based phosphate treatment can be used in addition to the zinc phosphate-based or manganese phosphate-based treatment described above.

The treatment conditions such as the liquid composition of the phosphate treatment, pH, treatment temperature, treatment time and the like can be ordinary conditions, but from the viewpoint of improving the adhesion of the metal fibers 4 to the matrix resin 2. Therefore, it may be appropriately determined according to the type of the metal fiber 4 to be used.

Specifically, the phosphate treatment is performed by using the metal fiber 4
It is preferable to perform so that a metal salt coating film having a coating amount of 0.2 to 10 g / m ² is formed on the surface. When the amount of the metal salt coating is less than 0.2 g / m ² , the modifying effect that contributes to the improvement of the adhesiveness due to the formation of the metal salt coating on the surface of the metal fiber 4 is not sufficient, and the matrix resin of the metal fiber 4 is insufficient. The adhesive strength with 2 does not increase. Conversely, the amount of metal salt coating is 1
If it exceeds 0 g / m ² , the metal salt coating becomes too thick, which causes the adhesive strength of the metal fiber 4 with the matrix resin 2 to decrease. Therefore, the amount of the metal salt film formed by the phosphate treatment is 0.2 to 10 g / m ² , preferably 0.
A range of 5 to 3.0 g / m ² is preferable.

An example of zinc phosphate treatment is Palpond L-3080 manufactured by Nippon Parker Rising Co., Ltd.
There is the use of the zinc phosphate processing system. If the metal fiber 4 is a stainless fiber, the conditions for the zinc phosphate treatment are as follows.

Total acidity 23 points Free acidity 0.9 points Accelerator concentration 3 points Temperature 45 ° C Immersion time 2 minutes

As the chromate treatment, a chromate treatment used for the surface treatment of a steel plate or the like can be used for almost all of the metal fibers 4, regardless of the type. Similarly,
The treatment conditions such as the liquid composition of the chromate treatment, the pH, the treatment temperature, the treatment time and the like can be performed under normal conditions, but the metal fibers used for the purpose of improving the adhesion of the metal fibers 4 to the matrix resin 2. It may be appropriately determined in consideration of the four types and the like.

Specifically, in the chromate treatment, the coating amount of 0.
It is preferable to carry out so that a metal salt coating (chromate coating) of 01 to 0.15 g / m ² is formed.

As an example of the chromate treatment, Zinchrome R-1415A manufactured by Nippon Parker Rising Co., Ltd.
There is a chromate treatment using. If the metal fiber 4 is a stainless fiber, the chromate treatment is as follows.

That is, the concentration of zinc chromium R-1415A is 1
1 point of treatment liquid was prepared, and the degreased and dried stainless fiber was coated with a roll coater at room temperature at a coating amount of 5 g
The coating is m ^2, dried further coated stainless fibers 80 ° C. dryer to remove moisture.

The above-mentioned phosphate treatment or the like can be carried out by immersing the metal fiber 4 in a treatment liquid. Prior to the phosphate treatment or the like, the surface of the metal fiber 4 is degreased and washed with water, and phosphoric acid is used. The reason why it is necessary to wash and dry the metal fibers 4 immediately after the salt treatment and the like is the same as in the case of the phosphate treatment and the like for ordinary steel plates and the like.

In the fiber-reinforced prepreg 1 of the present invention, the reinforcing fibers can be constituted by arranging the metal fibers 4 or the metal fibers 4 and the dissimilar fibers 6 in one direction. ) It is also possible to use in the state.

Table 1 shows various fiber-reinforced prepregs having at least metal fibers 4 as reinforcing fibers and prepared by arranging the reinforcing fibers in one direction, and racket frames were manufactured using these fiber-reinforced prepregs. The evaluation of the racket frame at the time is shown.

The metal fiber 4 is a stainless fiber having a fiber diameter of 20 μm, a titanium fiber having a fiber diameter of 20 μm, and a fiber diameter of 20 μm.
The aluminum fiber of m was used, which was previously subjected to chemical conversion treatment. The phosphate treatment was performed using PALPON L-3080 manufactured by Nippon Parker Rising Co., Ltd., and the chromate treatment was performed using Zinchrome R-1415A manufactured by Nippon Parker Rising Co., Ltd.

As the different fiber 6, PAN-based carbon fiber having a fiber diameter of 7.0 μm (trade name: T300, manufactured by Toray Industries, Inc.) is used as the carbon fiber, and the glass fiber has a fiber diameter of 13 μm.
Glass fiber (made by Asahi Fiber Glass Co., Ltd., standard name E glass), aramid fiber made of aramid fiber having a fiber diameter of 12 μm (made by Teijin Ltd., trade name Technora), and polyarylate fiber made of poly having a fiber diameter of 23 μm. Arilate fiber (trade name Vectran manufactured by Kuraray Co., Ltd.) was used.

Epoxy resin was used as the matrix resin 2 in each fiber reinforced prepreg.

[0043]

[Table 1]

As shown in Table 1, when the fiber-reinforced prepreg of the present invention was used (Examples 1 to 8), the metal fiber 4 was treated with zinc phosphate or chromate, and therefore the matrix resin was used. Adhesiveness with 2, good performance of the fiber reinforced prepreg by using the metal fiber 4, as a result, the resulting racket frame has improved torsional fracture strength and impact resistance In addition, the racket frame has a better feeling in use. On the other hand, in Comparative Examples 1 to 3, the metal fibers 4 were not subjected to the phosphate treatment or the chromate treatment, or even if the metal fiber 4 was subjected to the phosphate treatment, the coating amount was small and was not effectively performed. The adhesion of the fibers 4 to the matrix resin 2 was low, and thus the racket frame obtained was inferior in at least one of torsional fracture strength and impact resistance.

[0045]

As described above, the fiber-reinforced prepreg forming the fiber-reinforced prepreg layer of the racket frame of the present invention has at least one or a plurality of types of metal fibers as reinforcing fibers, and the surface of the metal fibers. Has a high degree of adhesion to the matrix resin of metal fibers because it has been subjected to phosphate treatment or chromate treatment, and it is necessary to fully exert the effect of improving mechanical strength by using metal fibers as reinforcing fibers. In particular, the mechanical strength such as the torsional fracture strength and the impact resistance is significantly improved, and the feel at the time of use, such as the shot feeling, is remarkably improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a racket frame according to the present invention.

FIG. 2 is a cross-sectional view of a conventional racket frame.

FIG. 3 is a cross-sectional configuration diagram of an example of the fiber reinforced prepreg according to the present invention.

FIG. 4 is a cross-sectional configuration diagram of another embodiment of the fiber reinforced prepreg according to the present invention.

[Explanation of symbols]

 1 Fiber Reinforced Prepreg 2 Matrix Resin 4 Metal Fiber 6 Different Fiber 1'Fiber Reinforced Prepreg Layer 101 Center Material 102 Outer Shell Molding Material

Claims (3)

[Claims] 1. A racket frame in which an outer shell molding is provided around a central material, and a fiber-reinforced prepreg layer having at least metal fibers having a phosphate treatment or a chromate treatment on the surface as reinforcing fibers, A racket frame provided at least in the outermost layer of the outer shell forming material or between the center material and the outer shell forming material. 2. The racket frame according to claim 1, wherein a metal salt coating film having a coating amount of 0.2 to 10 g / m ² is formed on the surface of the metal fibers by a phosphate treatment. 3. The racket frame according to claim 1, wherein a metal salt coating film having a coating amount of 0.01 to 0.15 g / m ² is formed on the surface of the metal fibers by a chromate treatment.