JPH04367677A - Racket frame - Google Patents

Abstract

PURPOSE:To provide the racket frame which is improved in mechanical strength and more particularly modulus of elasticity as compared with the conventional racket frames formed by using a fiber reinforced composite resin and is improved in the feel at the time of use and design characteristics as well. CONSTITUTION:The racket frame is produced by arranging a shell forming material around a central material. Further, a prepreg layer contg. 1st metallic fibers 2a arrayed and arranged in one direction and 2nd metallic fibers 2b arranged at a prescribed angle with the 1st metallic fibers 2a in the other direction in the form of intersecting with the 1st metallic fibers 2a as reinforcing fibers is provided on the outermost layer of the shell forming material.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to frames for various rackets, such as tennis rackets or badminton rackets, in which a molded outer shell is provided around a center member, and in particular, the present invention relates to frames for various rackets such as tennis rackets or badminton rackets, in which a molded outer shell is provided around the center member. The present invention relates to a racket frame characterized in that the outer layer is provided with a prepreg layer containing metal fibers arranged in mutually intersecting directions as reinforcing fibers.

0002

[Prior Art] Conventionally, for example, frames for tennis rackets have been used.
As shown in FIG. 2, the molded shell is composed of a core material 101 and an outer molded material 102, and in recent years, it has been said that it is lightweight, has high mechanical strength, and has good vibration damping characteristics. For this reason, a fiber-reinforced composite resin material using carbon fiber or glass fiber as the reinforcing fiber is used as the outer shell molding material 102.

[0003] Such a conventional racket frame is made by wrapping a predetermined number of fiber-reinforced prepregs to form an outer shell material 102 around a core material 101 made of, for example, hard urethane foam, and then hardening the material. It is made by

[0004] At this time, in order to improve the elastic modulus, torsional and bending performance, and furthermore to improve the vibration damping characteristics, a plurality of sheets of carbon fiber reinforced prepreg or a combination of carbon fiber reinforced prepreg and glass fiber are used. The outer shell molded material 102 is frequently constructed as a hybrid structure by overlapping reinforcing prepreg.

[0005]

[Problems to be Solved by the Invention] With this configuration, it is possible to reduce the weight of the racket frame, improve repulsive force, prevent breakage, and increase vibration damping characteristics, but also,
On the other hand, in recent years, there has been a demand not only for lighter weight and increased mechanical properties, but also for improved feel during use and even fashionability (design).

As a result of many research experiments, the present inventors have found that, for example, in a racket frame consisting of a plurality of carbon fiber reinforced resin layers, as the outermost layer of the carbon fiber reinforced resin layers, reinforcing fibers are formed in directions that intersect with each other. It has been found that by providing a prepreg layer containing arranged metal fibers, it is possible to provide a racket frame that can satisfy the above requirements.

That is, by providing a prepreg layer containing metal fibers arranged in mutually intersecting directions as reinforcing fibers on the outermost layer of a fiber-reinforced resin layer such as a carbon fiber-reinforced resin layer, fiber-reinforced composite resin Although it is a racket frame, it has a high elastic modulus and has been found to improve the feel during use. Furthermore, it has been found that when epoxy resin or the like is used as the matrix resin, the reinforcing fibers in the prepreg can be observed from the outside, resulting in excellent fashion and aesthetic appeal. The present invention has been made based on the novel findings of the present inventors.

Therefore, an object of the present invention is to be able to improve the mechanical strength, especially the modulus of elasticity, compared to racket frames using conventional fiber-reinforced composite resins, and to improve the feel and design during use. It is an object of the present invention to provide a racket frame with improved properties.

[0009]

[Means for Solving the Problems] The above objects are achieved with a racket frame according to the present invention. To summarize, the present invention provides an aspect in which, in a racket frame in which an outer molded material is provided around a center material, first metal fibers arranged in one direction intersect with the first metal fibers. A prepreg layer containing as reinforcing fibers the first metal fibers and second metal fibers arranged at a predetermined angle in the other direction is provided as the outermost layer of the outer shell molding material. This is a distinctive racket frame.

0010

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

In this embodiment, the racket frame according to the present invention, as shown in FIG.
It is produced by winding a predetermined number of fiber-reinforced prepregs for forming the outer shell molding material 102 and curing them.

Further, according to the present invention, the outer shell molding material 102
As the outermost layer of the prepreg layer 1', which will be explained in detail later,
is formed. That is, according to the present invention, the core material 101
and an outer shell molding material 102 provided around the center material 101.
and a prepreg layer 1' provided as the outermost layer, a racket frame is formed.

The core material 101 is preferably made of hard foamed urethane, and the outer shell material 102 is made of, for example, a plurality of sheets of carbon fiber reinforced prepreg, or a combination of carbon fiber reinforced prepreg and glass. By overlapping fiber-reinforced prepreg, a hybrid structure can be obtained.

The carbon fiber-reinforced prepreg and glass fiber-reinforced prepreg used may be ordinary ones, and the reinforcing fibers are carbon fibers (including graphite fibers) and glass fibers, and the matrix resin is epoxy. resin, unsaturated polyester resin, polyurethane resin,
Thermosetting matrix resins such as diallyl phthalate resin and phenolic resin can be used. Furthermore, a curing agent and other imparting agents, such as a flexibility imparting agent, are appropriately added so that the curing temperature is 50 to 200°C.

Next, prepreg layer 1 which is a feature of the present invention
' will be explained in more detail. 3 and 4 show an example of a prepreg 1 used to form a hybrid prepreg layer 1' according to the invention.

According to the present invention, the prepreg 1 includes first metal fibers 2a arranged as reinforcing fibers 2 in one direction, and the first metal fibers 2a arranged at an angle θ in another direction different from the first metal fibers 2a. The second metal fibers 2b are arranged in such a manner that they intersect with each other.
The reinforcing fibers 2 (2a, 2b) are impregnated with a matrix resin 4. The intersection angle θ is 1
0° to 90° is suitable.

The first and second metal fibers 2a and 2b include titanium fibers, tungsten fibers, amorphous fibers,
Stainless steel fibers or the like can be used, and the first metal fibers 2a and the second metal fibers 2b can be the same fiber or different metal fibers.

The first metal fiber 2a and the second metal fiber 2b are
Usually the fiber diameter is 10 to 150 μm, preferably 30 to 12
0 μm, a tensile modulus of 10 t/mm 2 or more, and a tensile strength of 100 Kg/mm 2 or more are preferable. The surface of such metal fibers can be coated with Au, Ag, Ni, Cu, etc. to improve interfacial strength and fashionability.

As the matrix resin 4, thermosetting matrix resins such as epoxy resin, unsaturated polyester resin, polyurethane resin, diallyl phthalate resin, and phenol resin can be used. Furthermore, the curing temperature is 5
A curing agent and other imparting agents, such as a flexibility imparting agent, are appropriately added so that the temperature is 0 to 200°C.

To give a preferable example, epoxy resin is preferable as the matrix resin, and usable epoxy resins include (1) glycidyl ether epoxy resin (bisphenol A, F, S epoxy resin, novolac epoxy resin) Resin, brominated bisphenol A
(2) Cycloaliphatic epoxy resin; (
3) Glycidyl ester type epoxy resin; (4) Glycidylamine type epoxy resin; (5) Heterocyclic epoxy resin; and one or more types selected from various other epoxy resins are used, especially bisphenol A, F , S glycidylamine-based epoxy resins are preferably used. In addition, as the curing agent, amine-based curing agents such as dicyandiamide (DICY), diaminodiphenylsulfone (
DDS), diaminodiphenylmethane (DDM); acid anhydride systems, such as hexahydrophthalic anhydride (HHPA)
, methylhexahydrophthalic anhydride (MHHPA), etc., and amine-based curing agents are particularly preferably used.

Further, the blending ratio of the first metal fibers 2a, the second metal fibers 2b, and the matrix resin 4 in the prepreg 1 of the present invention can be adjusted as desired. Further, according to the present invention, the thickness (T) of the prepreg is determined by the thickness of the metal fibers 2a, 2b used.
Although it varies depending on the fiber diameter, it is usually about 50 to 200 μm.

[0022] The prepreg 1 having such a structure can be manufactured by various methods. For example, a first prepreg manufactured by aligning first metal fibers 2a in one direction as reinforcing fibers, and second metal fibers 2b as reinforcing fibers.
and a second prepreg manufactured by arranging them in one direction.
The reinforcing fibers 2a and 2b of the first and second prepregs are at an angle θ
It can be manufactured by stacking them so as to form a shape, and then cutting them as shown in FIG.

[0023] Various prepregs were produced by the above method,
The prepreg was provided on the outermost layer of a racket frame made of carbon fiber reinforced composite resin, and its performance was evaluated. The results are shown in Table 1. The matrix resin used in the prepreg of the present invention was an epoxy resin.

[0024]

[Table 1]

As shown in Table 1, the racket frame manufactured using the prepreg 1 according to the present invention has mechanical strength and impact resistance that are at least the same or higher than those of the conventional racket frame, and It was found that the feel during use was better than before, and it was also superior in fashionability, ie, design.

[0026]

[Effects of the Invention] Since the racket frame according to the present invention is constructed as described above, it is possible to improve mechanical strength, especially elastic modulus, and also improve the feel and fashionability during use. It has the advantage of obtaining

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of one embodiment 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 a prepreg for manufacturing a racket frame according to the present invention.

FIG. 4 is a plan view of a prepreg for manufacturing a racket frame according to the present invention.

[Explanation of symbols]

1' prepreg layer 101
Center material 102 Outer shell molding material

Claims (1)

[Claims] 1. In a racket frame in which an outer shell molding material is provided around a center material, first metal fibers arranged in one direction and the first metal fibers are arranged in a manner that intersects with the other metal fibers. A prepreg layer containing, as reinforcing fibers, second metal fibers arranged at a predetermined angle with respect to the first metal fibers in the direction of the first metal fibers is provided as the outermost layer of the outer shell molding material. racket frame.