JPH03280976A - Golf club shaft - Google Patents

Abstract

PURPOSE:To improve toughness by forming a laminated prepreg layer, which is formed by providing a thermoplastic resin film of specific solubility on a surface of fiber-reinforced prepreg used with epoxy resin as matrix resin, on the outermost layer of a fiber reinforced compound resin layer. CONSTITUTION:In a golf club shaft formed of a plurality of fiber-reinforced compound resin layers 101, 102, a double-layer prepreg layer 1, which is formed by providing a thermoplastic resin film 8 with 9.0 to 11.5 solubility parameter on the surface of a fiber-reinforced prepreg 6 used with epoxy resin as matrix resin 4, is formed on at least the outermost layer of the above-mentioned fiber- reinforced compound resin layer. As a result, a golf club shaft is formed excellent in the point of preventing its break and the touch at the time of use and, further, in the point of molding workability and a beautiful feeling by improving toughness and impact absorbing characteristic without decreasing the mechanical characteristics such as tensile strength, compression strength, elastic modulus, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. The present invention relates to a golf club shaft constructed by laminating a plurality of fiber-reinforced composite resin layers, such as carbon fiber-reinforced composite resin layers. This invention relates to a golf club shaft characterized by having a small number of resin layers (in both cases, a multilayer prepreg layer is provided as the outermost layer).

In recent years, many golf club shafts have been made of carbon fiber-reinforced composite resin because they are lightweight, have high mechanical strength, and have good vibration damping properties. , has achieved good results.

Such a conventional golf club shaft is composed of a plurality of carbon fiber reinforced composite resin layers, and as shown in FIG. It is formed by winding it around a mandrel 100 and curing it. At this time, in order to improve torsion and bending performance, as shown in FIG. (Usually, θ = 35° to 45°)
As shown in FIG. Basically, as shown in FIG. 5, prepreg 101 (angle layer 101') is used for the inner layer of the golf club shaft, and prepreg 102 (straight layer 102°) is used for the outer layer. many.

However, in order to prevent breakage, it is desired to improve toughness and shock absorption characteristics, and in terms of feel during use (hitting feeling), as well as moldability and Further improvements are desired from the aesthetic point of view.

As a result of many research experiments, the present inventors have found that in a golf club shaft consisting of a plurality of carbon fiber reinforced composite resin layers, an epoxy resin of reinforcing fibers and matrix resin is used as at least the outermost layer of the carbon fiber reinforced composite resin layers. The solubility parameter is 9.0~ on the surface of prepreg consisting of
It has been found that by providing a multilayer prepreg layer formed by laminating thermoplastic resin films of No. 11.5, it is possible to provide a golf club shaft that can satisfy the above requirements. It has also been found that thermoplastic urethane elastomer is particularly preferable for the thermoplastic resin film.

The present invention has been made based on this new knowledge.

Therefore, an object of the present invention is to provide a golf club shaft that has improved toughness and shock absorption characteristics, and is improved in terms of breakage prevention and feel during use, as well as in terms of moldability and aesthetics. It is to be.

The above objects are achieved with the golf club shaft according to the present invention. In summary, the present invention provides a golf club shaft comprising a plurality of fiber-reinforced composite resin layers, in which at least the outermost layer of the fiber-reinforced composite resin layers has a solubility parameter on the surface of a fiber-reinforced prepreg using an epoxy resin as a matrix resin. This is a golf club shaft characterized in that a multilayer prepreg layer is formed by providing a thermoplastic resin film having a coefficient of 9.0 to 11.5. In particular, the thermoplastic resin film is preferably a thermoplastic urethane elastomer.

To explain further, in the golf club shaft according to the present invention, as shown in FIG. 1, the carbon fibers preferably have an angle (θ) (
Prepreg 101 arranged so as to be inclined by θ=35° to 45°) and prepreg 10 in which carbon fibers are arranged parallel to the axis of the golf club shaft.
2 and a multilayer prepreg l as the outermost layer, and is manufactured by curing. That is, according to the present invention,
A golf club shaft is formed that includes an angled layer 101', a straight layer 102°, and a multilayer prepreg layer l°. Further, as shown in FIG. 2, the multilayer prepreg layer 1° can be provided not only as the outermost layer but also between the angle layer 101° and the straight layer 102′.

In FIGS. 1 and 2, the angled layer 101° is the inner layer, but it is also possible to use the straight layer 102° as the inner layer. Further, the angle layer 101' and the straight layer 102' do not need to be one layer, but can be a plurality of layers if necessary.

The angled layer 101' and the straight layer 102' can be formed using conventional carbon fiber reinforced prepregs 101, 102.

In other words, carbon fiber reinforced prepreg 101.102 uses carbon fiber (including graphite fiber) as the reinforcing fiber, and as the matrix resin, epoxy resin, unsaturated polyester resin, polyurethane resin, diallyl phthalate resin, phenol resin. Thermosetting matrix resins such as, for example, can be used. Furthermore, the curing temperature is 50 to 200°C.
A curing agent and other imparting agents, such as a flexibility imparting agent, are appropriately added so as to give the following properties.

Of course, the angle layer 101° and the straight layer 102′ do not need to be made of carbon fiber reinforced prepreg, but may be made of other fibers as reinforcing fibers, or of various fiber reinforced blib groups. It is also possible to use these fiber-reinforced prepregs together with carbon fiber-reinforced prepregs for production.

Next, the multi-layer prepreg layer and the golf club shaft, which are the characteristics of the present invention, will be explained in more detail based on examples.

FIG. 6 shows an embodiment of a multilayer prepreg l used to form a multilayer prepreg layer 1° according to the present invention.

According to this embodiment, in the multilayer prepreg 1, a thermoplastic resin film 8 is provided on a fiber-reinforced prepreg 6 made of reinforcing fibers 2 and matrix resin 4.

Examples of the thermoplastic resin constituting the film 8 used in the present invention include polyurethane, polyethylene terephthalate, polyvinyl chloride, polycarbonate, polyvinylidene chloride, ethyl cellulose, and cellulose acetate. Among these, polyurethane resins are particularly preferred. These thermoplastic resins have good compatibility with the matrix resin epoxy resin, and the solubility parameter, which is an index of compatibility, is 9.0 to 11.5, preferably 9, which is around the solubility parameter of epoxy resin 9.7. It has a value of 5 to 11.0. According to such a thermoplastic resin film, the film can be satisfactorily adhered to the prepreg, and the film can be stably provided on the surface of the cured prepreg without peeling or the like even after curing.

On the other hand, with a thermoplastic resin film whose solubility parameter is outside the above range, it is difficult to adhere the film well to the prepreg and to stably provide the film on the surface of the cured prepreg without peeling or the like. .

The thickness of the film 8 is preferably about 5 to 100 μm.

When the thickness of the film exceeds 100 μm, the toughness and shock absorption properties are improved, but the decrease in other mechanical strengths, such as tensile strength, compressive strength, and elastic modulus, cannot be ignored. Further, if the thickness of the film 8 is less than 5 μm, it becomes too thin, and as will be described in detail later, post-processing of the outer surface after molding the golf shaft becomes difficult.

In the present invention, the reinforcing fiber used in the multilayer prepreg 1 is usually carbon fiber, but other reinforcing fibers such as glass fiber, boron fiber, alumina fiber, silicon carbide fiber, and silicon nitride fiber can also be used. Various organic fibers such as aramid fibers, polyarylate fibers, polyethylene fibers, and metal fibers such as titanium fibers, amorphous fibers, stainless steel fibers, and aluminum fibers can be suitably used.

Epoxy resin is suitable as the matrix resin,
Further, 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.

Preferred examples of the epoxy resin include (1) glycidyl ether epoxy resin (bisphenol A%F, S epoxy resin, novolac epoxy resin, brominated bisphenol A epoxy resin)
i (2) m-type aliphatic epoxy resin; (3) glycidyl ester-based epoxy resin; (4) glycidylamine-based epoxy resin (tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, etc.); (5) heterocyclic Epoxy resin: One or more selected from various other epoxy resins are used, and bisphenol A, F, and S glycidylamine-based epoxy resins are particularly preferably used. Further, as the curing agent, amine type curing agents such as dicyandiamide (DICY), diaminophenyl sulfone (DDS), diaminodiphenylmethane (DDM), acid anhydride type such as hexahydrophthalic anhydride (HHPA), methylhexahydrophthalic anhydride are used. (MHHPA) and the like are used, and amine-based curing agents are particularly preferably used.

An embodiment of the golf club shaft according to the present invention is as follows.

First, as shown in FIG. 3, a predetermined number of, for example, carbon fiber reinforced prepregs cut into predetermined shapes and dimensions are wound around a mandrel 100. At this time, as mentioned above, in order to improve torsion and bending performance, carbon fiber reinforced prepregs are usually made such that the carbon fibers are mutually aligned with respect to the axis of the golf club shaft, as shown in FIG. Angle (θ) in the opposite direction (usually θ = 35° ~
Prepreg 10 arranged so as to be inclined by 45°)
1 (angle l1F101') and a prepreg 102 in which carbon fibers are arranged parallel to the axis of the golf club shaft (θ=0°) as shown in FIG.
(straight layer 102°) is used, and as shown in FIG. Placed.

Next, the multilayer prepreg 1 (multilayer prepreg layer 1'') is wound around the outermost layer. At this time, film 8
Wrap it so that it is located on the outermost surface.

A pressing tape is wound on the prepreg laminate which has been wound and numbered on the mandrel 100 in this way, and then the prepreg laminate is heated and cured while the pressing tape prevents deformation of the prepreg layer. Get a golf club shaft.

After curing, the pressed cutave is removed from the surface of the golf club shaft, and then a smoothing process is performed to remove wrinkles on the surface of the cured prepreg body caused by the pressing tape during heat curing. This smoothing process is performed by heating the film 8 forming the surface of the obtained golf club shaft and pressing it to smooth out wrinkles, so that the wrinkles can be easily absorbed into the film and removed.

If the film 8 is transparent, decoration can be imparted to the surface of the golf club shaft. That is,
In the multilayer prepreg 1, for example, when carbon fibers and other different types of fibers are arranged in one direction to form reinforcing fibers, these different types of fibers will be visible through the surface,
The decorativeness of the surface of the golf club shaft can be further improved. In addition, according to the polyurethane resin film, it is also possible to give the surface of the cured prepreg body decorative properties by painting as in the conventional manner.

In fact, the reinforcing fiber 2 was a PAN-based carbon fiber with a fiber diameter of 6.5 μm (manufactured by Toshi Co., Ltd., product name "M2").
A carbon fiber-reinforced prepreg 6 was prepared using epoxy resin as the matrix resin, and on this surface,
By pasting a thermoplastic urethane elastomer film 8 with a thickness of 5 μm and a solubility parameter of 10.0,
Multilayer prepreg 1 was produced. The solubility parameter was determined from the solubility in the solvent.

Further, the matrix resin content of the prepreg 1 was 35% by weight, and the thickness was 50 μm excluding the film 8.

Furthermore, such a multilayer prepreg 1 was used to manufacture the golf club shaft shown in FIG. 1 as described above. The mechanical properties of the golf club shaft were measured, and although the golf club shaft of the present invention is lightweight, it has poor tensile strength, compressive strength, and elastic modulus.
It was superior to the conventional golf club shaft shown in FIG. 5 in terms of toughness and shock absorption, and also had a good feel during use. The golf club shaft according to the present invention was also aesthetically pleasing. The measurement results are shown in Table 1.

Table 1 m: Inferior to Comparative Example 1 Note: The solubility parameter of the polypropylene resin was 8°1.

The golf club shaft according to the present invention configured as described above has improved toughness and impact absorption properties without reducing mechanical properties such as tensile strength, compressive strength, and elastic modulus. It is excellent in terms of breakage prevention and feel during use, as well as moldability and aesthetics.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a golf club shaft according to the present invention. FIG. 3 is a diagram illustrating a method of manufacturing a golf club shaft. FIG. 4 is a plan view showing a prepreg for manufacturing a golf club shaft. FIG. 5 is a cross-sectional view of a conventional golf club shaft. FIG. 6 is a cross-sectional view of an embodiment of a multilayer prepreg for manufacturing a golf club shaft according to the present invention. 1°: Multilayer prepreg layer 101°: Angle layer 02' Nistrade layer: Multilayer prepreg: Reinforcing fiber: Matrix resin: Film

Claims (1)

[Claims] 1) In a golf club shaft composed of a plurality of fiber-reinforced composite resin layers, at least the outermost layer of the fiber-reinforced composite resin layers has a solubility parameter of 9 on the surface of a fiber-reinforced prepreg using an epoxy resin as a matrix resin.
．． A golf club shaft characterized in that a multilayer prepreg layer is formed by providing a thermoplastic resin film of 0 to 11.5.