JPS60165966A - Yarn wound core golf ball - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] FIELD OF THE INVENTION This invention relates to wound core golf balls.

In a thread-wound golf ball, the core material is a vulcanized rubber bag filled with water or a liquid made by adding barium sulfate, a small amount of ethylene glycol, etc. to water in a vulcanized rubber bag. A solid core of sulfur rubber balls is used.

A rubber thread layer with a diameter of about 5 to 7111111 is usually wound around this center, so a great amount of pressure is applied to the center. The pressure will be approximately 11 to 10 m.

In J3, a thread-wound golf ball with a liquid core at the center, the liquid at the center is under high pressure as described above, so if the vulcanized rubber bag that encloses the liquid is damaged, the liquid inside the bag may erupt and cover. There is. When a user who is interested in the structure of a golf ball disassembles the golf ball with a knife or the like, he or she may damage the center bag with the knife and the liquid may be sprayed onto his or her own eyeball, resulting in blindness.

In order to prevent this risk, thread wound golf balls have been largely converted to solid core golf balls in recent years.

However, the good feel and trajectory stability of a liquid core golf ball when hit cannot be obtained with a solid core golf ball, and liquid core golf balls are still favored by professional golfers and advanced golfers.

In Japanese Patent No. 1068835, the present inventors proposed a golf ball using a liquid core containing an aqueous alkali silicate solution as a liquid component. The fluidity of the concentrated aqueous alkali silicate solution is extremely low, so even if the outer skin of the core is damaged by a knife, etc., it will not be sprayed outside the golf ball, making it highly safe and having excellent properties as a golf ball. It is. However, since the aqueous alkali silicate solution has strong alkaline properties, it usually corrodes the vulcanized rubber bag used for the liquid core, making it unsuitable for long-term storage. Moreover, a coating material suitable for the above-mentioned liquid from an economical and production technology standpoint has not yet been developed and has not been industrialized.

The present inventors have studied a neutral material that does not attack the vulcanized rubber bag and has the same performance as the aqueous alkali silicate solution, and as a result, has arrived at the present invention.

That is, the present invention uses a sphere made of a water-containing gel of a water-soluble or hydrophilic polymer coated with a hydrophobic polymer elastomer as a center.
This invention relates to a thread-wound core golf ball.

Examples of water-soluble or hydrophilic polymers include starch, glycogen, hemicellulose, gelatin, polymer group polyalkylene oxide, polyacrylic acid, polymethacrylic acid or alkali metal salts thereof, methylcellulose, carboxymethylcellulose, polyacrylic acid. Amide etc. are exemplified.

Gelatin is a water-soluble protein derived from naturally occurring collagen.
Cross-linked hydrated gelatin which is protein I and is obtained by crosslinking this hydrated gelatin gel with formalin may also be used. Examples of hemicellulose include agar extracted from red algae with hot water, and konjac mannan, a type of hexasone present in the root mass of konjac.

Preferred examples include agar, gelatin or high molecular weight polyalkylene oxides (especially polyethylene oxide).

The above water-soluble or hydrophilic polymer contains 1 to 75% of the water-containing polymer in the hydrogel.
It is preferable to contain 1ff1%. More preferably, 1
It is 5 to 25% by weight.

Inert fillers such as barium sulfate, titanium oxide, metal powder, glass powder cellulose powder, etc. may be added to the water-containing glue for the purpose of adjusting specific gravity. The inert filler is hydrated glue 100
It is preferable to add 1 to 300% by weight based on the weight part.

The hydrophobic polymer elastomer that covers the hydrogel is not particularly limited, but includes, for example, vulcanized rubber, thermoplastic rubber represented by a block copolymer having polystyrene blocks at both ends of polybutadiene, and methoxymethylated rubber. Examples include nylon.

The center will have 1it next month! J: It is possible to mold the hemispherical cup I from a rubber sheet containing a vulcanizing agent, fill the hemispherical cup with the above-mentioned hydrous gel, press the hemispherical cup, and vulcanize it in a mold. e monkey.

The obtained liquid center is wrapped with a rubber thread ('J4) and then covered with a conventional cover material. The cover material may include balata, ionomer resin, etc., and is not particularly limited.

center diameter, thickness of rental coating material, thickness of thread-wound layer,
The thickness of the single layer of the cover is also not particularly limited.

Also, the balls can be used in both 1, 6 and 2 inch sizes and 1.68 inch balls.

In golf balls made according to the present invention, even if the center outer skin material is scratched with the tip of a knife, etc., the water-containing gel is unlikely to fly out because the core material has no fluidity; Since there is no force, there is almost no risk of damaging the eyeball.Also, unlike when using a solid core such as vulcanized rubber, hydrogel behaves similarly to a liquid under high pressure. Therefore, the same good impact feel and trajectory as the conventional liquid core can be obtained.

The present invention will be explained in more detail with reference to Examples.

Example 1 A pair of unvulcanized hemispherical cups with a diameter of 29n+n+ were molded from a soft vulcanizing agent-containing rubber sheet I- having a thickness of about 21nI111 and a specific gravity of about 2.0. The pair of hemispherical cups described above were filled with a 20% by weight hot aqueous solution of agar and cooled. To imitate that the agar solution had cooled and solidified, a pair of hemispherical cups filled with agar gel were pressed together from above and below. It was vulcanized in a mold to obtain a center with a diameter of about 28.5 mm.

Using this center, a 1.68 inch balata wood-coated golf ball was manufactured by a known method.

Obtained 1=The golf ball had the same hitting feel and flight performance as a comparative golf ball made using a known liquid core of the same diameter, and even if the golf ball was cut with a knife to remove the Renter coating. Agar gel was not sprayed.

A golf ball was prepared in the same manner as in Example 1, except that an aqueous solution of 20@ffi% gelatin was used in place of the agar in Example 1, and the same tests were conducted. The results were the same as in Example 1.

Control Takumi 1 20% by weight of high molecular weight polyethylene A oxide instead of agar
A golf ball was prepared in the same manner as in Example 1, except that a golf ball was used. As a result of conducting the same test as in Example 1, there was no change in impact feel or flight performance, and no liquid was ejected.

Round 1 Takumi The material of the unvulcanized hemispherical cup of Example 1 is approximately 1.6n in thickness.
+ m, using a soft vulcanizing agent compounded rubber sheet with a specific gravity of 1.1, 70% by weight of titanium oxide was added and dispersed in 100 parts by weight of a 20% by weight agar solution instead of a hot aqueous solution of 20% by weight agar. A golf ball was prepared in the same manner as in Example 1 except that the mixture was used. The results of the test conducted in the same manner as in Example 1 showed that the feel at impact and flight performance were similar to conventional golf balls, and there was no jetting of the liquid content.

Claims (1)

[Scope of Claims] 1. A thread-wound core golf ball whose center is a sphere made of a water-containing gel of a water-soluble or hydrophilic polymer coated with a hydrophobic polymer elastomer. 2. The water-soluble or hydrophilic polymer is starch, glycogen, hemicellulose, dilatin, polymer-retaining polyalgylene oxide, polyacrylic acid or polymethacrylic acid, or an alkali metal salt thereof, methylcellulose, carboxymethylcellulose, or 2. The thread-wound core golf ball according to item 1, which is made of polyacrylic acid amide. 3. The wound core golf ball according to item 2, wherein the hemicellulose is agar extracted from red algae or konjac mannan, which is a type of hexidine present in the root mass of konjac. 4. The thread-wound core golf ball according to item 2, wherein the gelatin is crosslinked hydrated gelatin obtained by crosslinking hydrated ratingles with formalin. 5. The thread-wound core Gornoball according to any one of Items 1 to 4, wherein the water-containing glue contains an inert filler. 6. The wound core golf ball according to item 5, wherein the inert filler is barium sulfate, titanium oxide, metal powder, glass powder, or cellulose balater.