JPH01110375A - Shaft for golf club - Google Patents

Abstract

PURPOSE: To obtain a shaft without lowering of characteristic of weight and torsional rigidity and having a higher impact strength by arranging an inner layer part containing a carbon fiber and an outer layer part containing an oxynitride glass fiber provided on the perimeter thereof. CONSTITUTION: Oxynitride glass as glass fiber material used for an outer layer part has a structure which has an oxygen atom replacing nitrogen in an oxide glass and has a higher elastic modulus. The oxynitride glass fiber used as reinforcing fiber preferably has a constitution of Si 13-24at%, Ca, 10-21at%, Mg 0-5.2at%, Al 0-15.1at%, N 7.5-25at% and, M 0-5at% (M: Zr, Sr, Ba, Y, Ce, Na, B, La, K and Ti). As a matrix resin herein used is the outer layer part, an unsaturated polyester resin, a phenol resin, an epoxy resin or the like are cited. A fiber-reinforced resin containing a carbon fiber composing the inner layer part of this shaft may be a material used conventionally.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shaft for a golf club made of fiber reinforced plastics.

Conventional technology Golf club shafts made of carbon fiber reinforced plastics are commonly referred to as black shafts, and because they are lighter than steel shafts, they can fly the ball farther, and are widely used as an alternative to steel shafts.

Carbon fiber has a high specific modulus of elasticity, is lightweight, and has the same hardness as a steel shaft, but has low breaking strain and low impact breaking strength.

A shaft for a golf club is subjected to a very large impact load when hitting a ball, so if the impact breaking strength is low, the shaft will be damaged. Therefore, in order to strengthen the impact strength of shafts that use carbon fiber as reinforcing fibers, some shafts have a metal pipe inserted in a part of the narrow diameter part of the shaft, but this may cause separation between the carbon fiber plastic layer and the metal pipe, or Since materials with different specific gravity and specific elasticity are used for some parts, the feeling during use is poor.

In addition, as for those using glass fiber as reinforcing fiber, JP-A-50-19538, JP-A-50-72730,
There are JP-A-51-37733 and JP-A-53-61440, both of which are made by winding oxide glass at a predetermined angle on a carbon fiber reinforced plastic layer.

Problems to be Solved by the Invention Conventional golf club shafts whose outer layer is covered with E-glass fiber, etc., reduce the trouble of color coating and prevent the coating surface from being worn away and the carbon fibers being exposed. It is intended to prevent However, E-glass has low impact resistance and weak adhesion to carbon fibers. For this reason, when hitting a ball,
The glass fibers were destroyed by the impact, and due to poor adhesion to the carbon fibers, repainting was required.

The present invention provides a shaft that has higher impact strength than conventional carbon fiber-reinforced plastic golf club shafts that use oxide glass fibers for the outer layer, has almost no decrease in weight and torsional rigidity, and is inexpensive. It is something to do.

Means for Solving the Problems That is, the present invention provides a golf club comprising an inner layer containing carbon fibers and an outer layer containing oxynitride glass fibers provided around the inner layer. This provides a shaft for use.

Oxynitride glass, which is the glass fiber raw material used for the outer layer in the present invention, has a structure in which the oxygen atoms of oxide glass are replaced with nitrogen, and the bond valence of the nitrogen atom is 3. Compared to the glass of
Has high elastic modulus.

Methods for producing such oxynitride glass include a sol-gel method in which a metal alkoxide is hydrolyzed and then subjected to dehydration condensation, or a melting method in which a metal oxide and a metal nitride are melted.
Furthermore, there are N gas blowing methods, NH3 gas treatment methods for porous glass, etc., and it is possible to obtain an elastic modulus of 12°500 kg/in'' or more, which has not been achieved with conventional glass fibers.

The oxynitride glass fibers used as reinforcing fibers in the present invention contain 13 to 24 at% of Si and 10 to 20% of Ca.
21 at%, MgO~5.2 at%, AlO~15.
lat%, N 7.5-25at%, MO-5at% (
M: Zr5Sr, Ba, Y, Ce, Na, B, La,
KqTi) is preferred.

If the content of St is less than the above range, crystallization will occur and a glass state will not be obtained. If the amount exceeds this range, the elastic modulus decreases to 12,500 kg/mm'' or less.

Moreover, if the Ca content is less than the above range, crystallization will occur, while if it exceeds this range, the elastic modulus will be 125QOk.
g/+m”.

Furthermore, if the Mg content exceeds the above range, crystals will occur.

Further, if the nitrogen content is less than the above range, the nitrogen content has no effect, and if it exceeds this range, crystallization occurs.

The oxynitride glass used in the present invention has strength,
From the viewpoint of N content, it is preferable to manufacture by a melting method. To obtain oxynitride glass by the melting method, metal nitride is added to metal oxide and melted at high temperature.

Examples of metal oxides include 5iOa, CaO1Mg01
AIto3.5rO1Na,0,K,0,Lat,s,
Y! 03, ZrO,, Ties, NatOlK, o, B
Examples include aO1B t Os.

Examples of metal nitrides include 5f3N+ and AIN.

To melt the mixture of these metal oxides and metal nitrides, a heating furnace such as an electric furnace or an image furnace is used in a nitrogen atmosphere at a temperature of 1400 to 1900°C and a heating rate of 10 to 800°C.
Process at ℃/min.

The obtained glass was heated under a nitrogen atmosphere at a temperature of 1100~! 60
Heat and melt at 0°C and spin at a spinning speed of 20~.

Spun at 3000 m/+in to obtain continuous fibers.

The obtained glass fiber has an elastic modulus of 12,500 to 1,800.
0kg/mm”, tensile strength 70-500 kg/a
m' is obtained.

The fiber diameter of the glass fiber is preferably 3 to 150 μm. If the fiber diameter is smaller than this, spinning is difficult;
On the other hand, if it exceeds this range, the strength will be extremely reduced, which is not preferable.

Furthermore, as the matrix resin for the outer layer portion, any resin conventionally used as a matrix for glass fibers can be used. Examples include unsaturated polyester resins, phenol resins, and epoxy resins, and these may be used alone or in combination of two or more. Further, the mixing ratio of glass cloth in the prepreg is about 40 to 80%.

Note that the fiber reinforced plastic containing carbon fibers constituting the inner layer of the shaft of the present invention may be any of those conventionally used in such golf club shafts.

To form the above-mentioned outer layer containing glass fiber on the inner layer containing carbon fiber of the golf club shaft, the spray-up method in which short fibers are sprayed, the filament winding method, etc. are used, as in the case of using conventional glass fiber. Any known method can be used.

X night animal Next, the present invention will be explained in more detail with reference to Examples.

(Manufacturing example) SiO* 20. Omo1%, Ca0 40.8mo
1%MgO12,0s+o1%, AI, 0314.41
1101% were mixed and melted in air at 1500°C for 2 hours. After the mixture was cooled, it was ground to approximately 10 μm size using a ball mill, 12.8 mo1% of S 13 Na was added, and the mixture was melted in nitrogen at 1750° C. for 30 minutes using a boron nitride crucible to obtain oxynitride glass. The obtained glass is placed in a boron nitride crucible placed in a spinning device, heated at 1380°C in a nitrogen atmosphere using a cylindrical carbon heating element whose surroundings are insulated, and then spun and wound into a winder. Ta. Continuous fibers with a diameter of 15 μm were obtained at a spinning speed of 1500 m/akin. The tensile modulus of the obtained glass fiber was 12,600 kg/mm''.

Example 1 As shown in FIG.
The inner layer 2 was wound on a conical metal core having a diameter of 141mm, a diameter of 141mm, a length of 1300mm, and a thickness of 3111ffi by a filament winding method. Next, a prepreg obtained by impregnating the oxynitride glass fiber obtained in the above production example with an epoxy resin was wound to a layer thickness of approximately 111II11 to form an outer layer 1. A film with good mold releasability was placed on top of the mold, and the mold was cured by heating. After curing, the mold was removed. After demolding, it is cut and the outer layer is ground to the specified dimensions and hardness to produce a fiber-reinforced plastic golf club shaft.

Effects of the Invention According to the present invention, a golf club with extremely high elasticity can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the shaft for a golf club of the present invention. The symbols in the figure are as follows. ■=Outer layer, 2: Inner layer. Figure 1

Claims (1)

[Claims] (1) A golf club shaft comprising an inner layer containing carbon fibers and an outer layer surrounding the inner layer containing oxynitride glass fibers.