JPH10309334A - Golf shaft and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the odd sound of a nonmetallic shaft by forming the adhesive layer between a metallic ring and a nonmetallic shaft part by specifying the pts.wt. of the butadiene-acrylonitrile copolymer and nitrile rubber in a reaction product to a specific range with respect to the prescribed pts.wt. of the entire epoxy resin component. SOLUTION: This golf shaft 1 is formed by interposing the adhesive layer 30 between the nonmetallic shaft part 10 constituting the main body of the golf shaft 1 and the metallic ring 20 fixed to part of the surface of the nonmetallic shaft part 10. The adhesive layer 30 consists of the reaction product of the epoxy resin and the butadiene-acrylonitrile copolymer having carboxyl groups at both terminals and is so constituted that the copolymer of the reaction product is 3 to 30 pts. wt. per 100 pts.wt. total epoxy resin component and the nitrile rubber is 15 to 65 pts.wt. per 100 pts.wt. total epoxy resin component. As a result, the arbitrary setting of the weight balance of the nonmetallic shaft part 10 is made possible and the generation of the odd sounds is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf shaft in which a non-metal shaft portion, which is a main component of the golf shaft, is provided with a metal ring for balance adjustment, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Shafts used in golf clubs are:
They are roughly classified into steel shafts and non-metal shafts mainly made of carbon fiber. In recent years, the performance of the latter non-metal shaft has been dramatically improved, and the user orientation in the secondary market is currently shifting from steel shafts to non-metal shafts.

[0003] However, for a user who has used a steel shaft for many years, changing the steel shaft to a non-metallic shaft will change the balance of the entire golf club, causing a slight discomfort when actually swinging, and causing a sense of incongruity. There is a problem that it doesn't feel right.
In order to solve this problem, for example, a swing balance is adjusted by attaching a weight to the bottom of the head or filling lead inside the hosel insertion portion at the tip of the shaft. However, such a swing balance adjustment method is a very difficult method from the viewpoint of providing golf club products, and it can be said that it is rather a range in which the user can adjust the taste after purchase. .

Under these circumstances, in order to simplify the adjustment of the swing balance, a golf club in which a metal ring for adjusting the balance is fitted on the surface of a golf shaft has been commercialized and provided to the market. ing.

[0005]

However, when a golf ball is actually hit with a golf club having such a metal ring, the golf club is fixed to the surface of the golf shaft due to temporary bending deformation and impact of the shaft. The metal ring for balance adjustment peeled off the shaft,
Pili ... Piris may occur. A golf shaft in which such abnormal noise is generated has no commercial value, and can be developed into a credibility problem of a manufacturer.

The present invention has been made in view of such circumstances, and it is an object of the present invention to arbitrarily set the weight balance of a nonmetal golf shaft while maintaining the characteristics of the nonmetal golf shaft sufficiently. It is an object of the present invention to provide a golf shaft capable of preventing generation of abnormal noise and a method of manufacturing the same. Of course, to prevent this noise,
Must be guaranteed for long-term use.

[0007]

In order to solve the above-mentioned problems, a golf shaft according to the present invention comprises a non-metal shaft portion which is a main component of the golf shaft, and a metal ring fixed to the surface of the non-metal shaft portion. And an adhesive layer interposed between the metal ring and the non-metallic shaft portion, wherein the adhesive layer comprises (a) an epoxy resin and (b) a butadiene-acrylonitrile copolymer having carboxyl groups at both ends. A reaction product of the union and the epoxy resin, and (c) an adhesive containing a nitrile rubber, wherein the butadiene-acrylonitrile copolymer in the reaction product of the component (b) is added to 100 parts by weight of the total epoxy resin component. 3 to 30 parts by weight, and the nitrile rubber as the component (c) is 15 to 65 parts by weight based on 100 parts by weight of the total epoxy resin component.

[0008] In a more preferred aspect of the present invention, the adhesive layer is formed as an adhesive prepreg obtained by impregnating a base cloth with the adhesive.

As a more preferred aspect of the present invention, the metal ring is attached in a state where the non-metal shaft portion is pushed in at a contact portion with the non-metal shaft portion, and the surface of the metal ring has no metal ring. It is configured to form a surface that is substantially the same as the surface of the non-metallic shaft.

[0010] In a more preferred aspect of the present invention, the non-metallic shaft portion joined to the metal ring via the adhesive layer is formed by winding a carbon fiber-containing shaft prepreg.

The present invention also provides a step of covering a mandrel serving as a core metal with a tubular film, and winding a prepreg for a shaft containing reinforcing fibers on the film, and an adhesive on the prepreg for the shaft. Forming a pre-formed body by attaching a metal ring through the process, mounting the pre-formed body in a mold, and clamping the mold; air-charging the inside of the tubular film; and a prepreg for a shaft. Of the metal ring and the surface of the non-metal shaft where the metal ring does not exist are made substantially the same surface.

In a more preferred aspect of the present invention, the prepreg for a shaft is a prepreg containing carbon fibers.

Further, the golf shaft of the present invention has a non-metallic shaft portion which is a main component of the golf shaft, a metal ring fixed to the cylindrical inner surface of the non-metallic shaft portion, and the metal ring and the non-metallic shaft portion. Having an adhesive layer interposed therebetween, wherein the adhesive layer comprises: (a) an epoxy resin;
(B) a reaction product of a butadiene-acrylonitrile copolymer having carboxyl groups at both ends and an epoxy resin, and (c) an adhesive containing a nitrile rubber, wherein the reaction product of the component (b) is used. Butadiene-
Acrylonitrile copolymer has 100 total epoxy resin components
3 to 30 parts by weight with respect to parts by weight, and 15 to 65 parts by weight of the nitrile rubber as the component (c) with respect to 100 parts by weight of the total epoxy resin component.

[0014]

Embodiments of the present invention will be described below in detail.

First, a preferred configuration example of the golf shaft of the present invention will be described with reference to FIGS. 1 (a) and 1 (b). FIG. 1A is a schematic overall view of a golf shaft 1 of the present invention, and FIG. 1B is a partially enlarged schematic sectional view of a portion A in FIG. 1A.

The golf shaft 1 of the present invention has a non-metallic shaft portion 10 which is a main component of the golf shaft, a metal ring 20 fixed to a part of the surface of the non-metallic shaft portion 10, a metal ring 20 and a non-metallic member. It has an adhesive layer 30 interposed between the shaft portion 10.

The non-metallic shaft portion 10 has a cylindrical shape formed by coating carbon fibers, and is usually a carbon fiber-containing sheet material of carbon fibers called “prepreg for shaft” (carbon fibers are cured by (Attached with a resin-containing adhesive) is wound in multiple layers. There is no particular limitation on the lamination structure, and various known structures (for example, a carbon fiber straight layer,
Bias layer, carbon fiber cloth layer, etc.) can be adopted. Moreover, you may combine fibers (for example, aramid fiber, boron fiber) other than carbon fiber.

The metal ring 20 is mainly used for adjusting the balance of the shaft, and various metal materials such as copper, copper alloy, aluminum and aluminum alloy are used. Among them, it is particularly preferable to use copper or a copper alloy from the viewpoint that the specific gravity is large and the balance adjustment is easy. The fixing position of the metal ring 20 is shown in FIG.
When it is formed on the front surface side of the shaft as shown in FIG.

Such a metal ring 20 is attached at a contact portion with the non-metallic shaft portion 10 by pushing the non-metallic shaft portion as shown in FIG.
It is preferable to form the surface 20a of the metal ring 20 so as to form substantially the same surface as the surface 10a of the non-metal shaft 10 where the metal ring 20 does not exist, in order to increase the commercial value. That is, a molding method that eliminates surface irregularities due to the attachment of the metal ring 20 is adopted. This will be described later.

The adhesive layer 30 interposed between the metal ring 20 and the non-metal shaft portion 10 includes (a) an epoxy resin,
(B) an adhesive containing a reaction product of a butadiene-acrylonitrile copolymer having carboxyl groups at both ends and an epoxy resin, and (c) an adhesive containing nitrile rubber.

(A) As the epoxy resin, bisphenol A type epoxy resin, novolak type epoxy resin, alicyclic epoxy resin and the like are used. Among them, a novolak type epoxy resin is particularly preferable. In particular, those having an epoxy equivalent of 300 to 600 are preferably used. Specifically, Epicoat 834, Epicoat 1001, Epicoat 152 (manufactured by Shell Chemical Co., Ltd.), brominated bisphenol A
Type epoxy, DER511 (manufactured by Dow Chemical Company) and the like.

The butadiene-acrylonitrile copolymer having a carboxyl group at both terminals in the component (b) includes Hiker CTBN (manufactured by BF Goodrich Co.).
And the like. Further, the epoxy resin in the component (b) may be the same as or different from the epoxy resin in the component (a). Specifically, the same ones as described in the above component (a) are mentioned as preferred examples. The reaction product of the component (b) is produced, for example, in the presence of a predetermined catalyst under predetermined reaction conditions.

The nitrile rubber in the component (c) comprises a copolymer containing butadiene and acrylonitrile as main components, and can be selected from various known ones.
In addition, it may be partially carboxy-modified.

The butadiene-acrylonitrile copolymer in the reaction product of the above component (b) is based on 100 parts by weight of the total epoxy resin component (per 100 parts by weight of the total of the epoxy resins in the components (a) and (b)). 3
-30 parts by weight, preferably 5-20, more preferably 7
-15 parts by weight. If the value is less than 3 parts by weight, the adhesive strength and the flexibility are reduced, and when the golf ball is actually hit, the metal ring 20 is peeled off at the same time as the shaft is bent, which may cause abnormal noise. This value is 3
If the amount is more than 0 parts by weight, the adhesive strength becomes too large and the handling becomes poor.

The nitrile rubber as the component (c) is used in an amount of 15 to 65 parts by weight based on 100 parts by weight of the total epoxy resin component (per 100 parts by weight of the total of the epoxy resins in the components (a) and (b)). Preferably 20-6
0 parts by weight, more preferably 35 to 45 parts by weight. If the content is less than 15 parts by weight or exceeds 65 parts by weight, the adhesiveness and flexibility deteriorate, and when the golf ball is actually hit, the metal ring 20 is bent at the same time as the shaft is bent. Peeling may cause abnormal noise.

In the above-mentioned adhesive used in the present invention,
Usually, a curing agent is added.

The adhesive layer 30 may be constituted by the above-mentioned adhesive itself, or may be constituted as an adhesive prepreg obtained by impregnating a base cloth with the above-mentioned adhesive. As the base cloth, a glass fiber cloth, a polyester fiber cloth, or the like is used. It is preferable to use a glass fiber cloth in order to adapt to the bending of the shaft. The amount of the adhesive to be impregnated into the base cloth is preferably in the range of 40 to 95% by weight. Thereby, generation of abnormal noise can be prevented. The method of impregnating the adhesive may be, for example, a known method of impregnating and drying using a solvent or the like.

By providing such an adhesive layer 30, the metal ring 20 can be prevented from being corroded, although it is an incidental effect. Next, a method of manufacturing the golf shaft described above will be described with reference to FIGS.

First, a mandrel 40 serving as a cored bar
A tubular prepreg 60 containing reinforcing fibers (carbon fibers or the like) prepared in advance is wound on the tubular film 50 (FIG. 2A,
(B)).

An adhesive is applied to a predetermined position 31 of the wound shaft prepreg 60, or an adhesive prepreg is arranged, and the metal ring 20 is inserted from one side (FIG. 2B), and the metal ring 20 is attached. The preform P is formed by being attached to the predetermined position 31 (FIG. 2C).

Next, as shown in FIG. 3A, the preform P is mounted in the cavities of the molds 71 and 75, and the mold is clamped. Thereafter, the inside of the tubular membrane 50 is charged with air, and the prepreg 6 for the shaft is also charged.
0, the surface 20a of the metal ring 20 and the metal ring 2 as shown in FIG.
An internal pressure pressing operation is performed so that the surface 10a of the non-metallic shaft 10 where 0 does not exist is substantially the same surface.

Next, as shown in FIG. 3 (b), after the shaft prepreg 60 is thermally cured, the mandrel 4
0 and the tubular film 50 are removed to complete a golf shaft molded product.

In the above embodiment, the case where the metal ring 20 is formed on the surface side of the golf shaft has been described as an example. However, it is also possible to form the metal ring on the cylindrical inner surface of the golf shaft.

For example, as shown in FIG. 4 (a), a notch 42 is formed in a part of the mandrel 40, and the metal ring 2 along the notch shape is formed in the notch 42.
0 is inserted (FIG. 4 (b)), the adhesive used in the present invention is applied to the surface 20a of the metal ring 20, or the prepreg for bonding is attached. Thereafter, the prepreg for the shaft is wound and heated. Mandrel 40 after curing
To obtain a cylindrical golf shaft molded product.
In this case, the internal pressure press operation is not performed.

[0035]

Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

(Example 1) Adhesive resin composition / (a) composition: epoxy resin (Epicoat 1001) 9
70 g · (b) composition: epoxy resin (Epicoat 828) 30
g and a reaction product of 70 g of a butadiene-acrylonitrile copolymer having carboxyl groups at both terminals (Hiker CTBN). (c) Composition: Nitrile rubber (Niple 1072)
400 g Dicyandiamide 60 g 3- (3,4-dichlorophenyl) -1,1-dimethylurea 50 g The above adhesive resin composition was dissolved in a mixed solvent of acetone and methyl cellosolve to obtain a 35% by weight solution.

The resin solution thus prepared was impregnated into a base cloth (glass fiber cloth) to prepare an adhesive prepreg having a resin content of 80% by weight.

The adhesive prepreg was used as an adhesive layer, and FIG.
And the golf shaft sample 1 using the carbon fiber of this invention was produced by the manufacturing method along FIG.

With respect to this golf shaft sample 1,
An abnormal sound generation test was performed in the following manner.

An abnormal noise generation test After 1000 golf balls were hit by a test hitting machine, a test hit was actually performed by a person to confirm whether or not abnormal noise was generated.

As a result of this abnormal sound generation test, generation of abnormal noise was not confirmed.

(Embodiments 2 to 7)
30 g of butadiene-acrylonitrile copolymer (Hiker CTBN) in the composition (b) of the adhesive resin composition
Instead of 0 g, 120 g, 200 g, 250 g, and 300 g, respectively. Except for this, golf shaft samples 2 to 7 of the present invention were produced in the same manner as in Example 1 above. When an abnormal noise generation test was performed on each of these samples in the manner described above, no abnormal noise was generated.

Comparative Example 1 In Example 1, the amount of the butadiene-acrylonitrile copolymer (Hiker CTBN) in the composition (b) of the adhesive resin composition was changed to 20 g. Except for this point, a golf shaft comparative sample 1 was manufactured in the same manner as in Example 1 above. An abnormal sound generation test was performed on the comparative sample 1 in the manner described above.
The generation of a tingling noise was confirmed.

(Examples 8 to 12) In Example 1, 150 g, 300 g, and 50 g of nitrile rubber (Niple 1072) which is the composition (c) of the adhesive resin composition were used.
0 g, 600 g, and 650 g, respectively. Except for this, golf shaft samples 8 to 12 of the present invention were produced in the same manner as in Example 1 above. When an abnormal noise generation test was performed on each of these samples in the manner described above, no abnormal noise was generated.

(Comparative Examples 2-3) In Example 1 described above,
Nitrile rubber (N) which is the composition (c) of the adhesive resin composition
(ipple 1072) was changed to 100 g and 700 g, respectively. Except for this, golf shaft comparative samples 2 and 3 were produced in the same manner as in Example 1 above. When an abnormal sound generation test was performed on each of these samples in the manner described above, generation of an abnormal sound was confirmed.

Example 13 In Example 1, the adhesive prepreg was replaced with an adhesive layer consisting of only an adhesive. Other than that was carried out similarly to the said Example 1, and produced the golf shaft sample 13. When an abnormal noise generation test was performed on each of the samples in the manner described above, no abnormal noise was generated.

[0047]

The effects of the present invention are clear from the above results. That is, the golf shaft of the present invention includes a non-metallic shaft portion that is a main component of the golf shaft, a metal ring fixed to the surface of the non-metallic shaft portion, and a metal ring interposed between the metal ring and the non-metallic shaft portion. A reaction product of (a) an epoxy resin, (b) a butadiene-acrylonitrile copolymer having a carboxyl group at both ends and an epoxy resin, and (c) a nitrile rubber. Wherein the butadiene-acrylonitrile copolymer in the reaction product of the component (b) is 3 to 30 parts by weight based on 100 parts by weight of the total epoxy resin component, and the nitrile as the component (c) is used. The rubber is 15 to 100 parts by weight of the total epoxy resin component.
Since it is configured to be 65 parts by weight, the weight balance of the non-metallic golf shaft can be arbitrarily set while the characteristics of the non-metallic golf shaft are sufficiently maintained, and the generation of abnormal noise can be prevented.

[Brief description of the drawings]

FIG. 1A is a schematic overall view of a golf shaft 1 of the present invention, and FIG. 1B is a partially enlarged schematic sectional view of a portion A in FIG. 1A.

2 (a) to 2 (c) are drawings showing a method of manufacturing a golf shaft over time.

FIGS. 3A and 3B are drawings showing a method of manufacturing a golf shaft over time.

FIGS. 4A and 4B are partial enlarged views each showing a main part of a mandrel for molding a non-metallic golf shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Golf shaft 10 ... Non-metallic shaft part 20 ... Metal ring 30 ... Adhesive layer 40 ... Mandrel 50 ... Tubular film 60 ... Prepreg for shaft

Claims (7)

[Claims] 1. A golf club comprising: a non-metal shaft portion which is a main component of a golf shaft; a metal ring fixed to a surface of the non-metal shaft portion; and an adhesive layer interposed between the metal ring and the non-metal shaft portion. Wherein the adhesive layer comprises (a) an epoxy resin, (b) a reaction product of a butadiene-acrylonitrile copolymer having carboxyl groups at both ends and an epoxy resin, and (c)
A butadiene-acrylonitrile copolymer in the reaction product of the component (b), which has an adhesive containing a nitrile rubber;
A golf shaft, wherein 30 parts by weight of the nitrile rubber as the component (c) is 15 to 65 parts by weight based on 100 parts by weight of the total epoxy resin component. 2. The golf shaft according to claim 1, wherein the adhesive layer is an adhesive prepreg obtained by impregnating the adhesive into a base cloth. 3. The metal ring is attached in such a manner that the non-metal shaft portion is pushed in at a contact portion with the non-metal shaft portion, and the surface of the metal ring is in contact with the surface of the non-metal shaft where the metal ring does not exist. The golf shaft according to claim 1 or 2, wherein the golf shaft has substantially the same surface. 4. The non-metallic shaft portion joined to the metal ring via the adhesive layer is formed by winding a carbon fiber-containing shaft prepreg. The golf shaft of the above. 5. A step of covering a mandrel serving as a core metal with a tubular film, and winding a prepreg for a shaft containing reinforcing fibers on the film, and applying a metal on the prepreg for the shaft via an adhesive. A step of forming a preformed body by attaching a ring; a step of mounting the preformed body in a mold and clamping the mold; and charging air inside the tubular film and at least a part of a shaft prepreg. A golf ball manufacturing method comprising: an internal pressure pressing step of expanding the surface of the metal ring and the surface of the non-metal shaft having no metal ring substantially the same surface. 6. The method according to claim 5, wherein the shaft prepreg is a prepreg containing carbon fiber. 7. A non-metallic shaft portion which is a main component of a golf shaft, a metal ring fixed to a cylindrical inner surface of the non-metallic shaft portion, and an adhesive interposed between the metal ring and the non-metallic shaft portion. A bonding product comprising: (a) an epoxy resin; (b) a reaction product of a butadiene-acrylonitrile copolymer having carboxyl groups at both ends and an epoxy resin; and (c)
A butadiene-acrylonitrile copolymer in the reaction product of the component (b), which has an adhesive containing a nitrile rubber;
A golf shaft, wherein 30 parts by weight of the nitrile rubber as the component (c) is 15 to 65 parts by weight based on 100 parts by weight of the total epoxy resin component.