JPS60241465A - Yarn wound core for 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 However, the core can also be used as a core for solid golf balls.

Conventional technical wound golf balls have either a liquid core (a core made of water or an aqueous paste containing barium sulfate, a small amount of ethylene glycol, etc., placed in a vulcanized rubber bag) or a solid vulcanized rubber core wrapped with stretched rubber thread. It has a similar configuration. A large amount of force is applied to the core when it is hit, so especially in the case of a liquid core, the vulcanized rubber bag often ruptures and the internal liquid leaks out, significantly reducing the performance of the ball. If the ball is cracked due to excessive impact, or if the ball is dismantled for some purpose or interest, the liquid core will be extremely dangerous as it will forcefully squirt out the internal liquid due to damage to the bag. In some cases, the ejected liquid may hit the eye and cause blindness.

For this reason, thread-wound golf balls using a solid core have become mainstream recently, but thread-wound golf balls using a liquid core are particularly popular among professional golfers and general golfers because of their unique hitting feel and stable flight performance. It remains very popular among advanced players.

Problems to be Solved by the Invention In order to improve these drawbacks, the present inventors first developed an aqueous alkali silicate solution (see Japanese Patent No. 1068835) or a water-soluble polymer gel (Japanese Patent Application Laid-Open No. 135037/1989).
We have developed a thread-wound golf ball using a liquid core made of liquid rubber (see Japanese Patent Publication No. 2003-111100) and one lug.

However, in the case of these golf balls, as in the case of conventional thread-wound golf balls using a liquid core, the liquid component must be enclosed in a bag made of vulcanized comb, so when using a solid core, the soba ratio is lower. However, the disadvantages of requiring a complicated process and extremely poor productivity have not been overcome.

On the other hand, in the case of a thread-wound golf ball using a solid core, materials such as cis-1゜4-polybutadiene and silicone rubber, which have excellent rebound properties, have a low glass transition temperature, so they solidify on cooling and do not deform. It is extremely difficult to wind a stretched rubber thread onto a core, and it is necessary to make the thread as hard as possible.

Means for Solving the Problems The present inventor has completed the present invention by finding that all of the above problems can be solved by microencapsulating an aqueous liquid core containing an inert filler.

That is, the present invention relates to a thread-wound golf ball core formed by curing a liquid rubber containing microcapsules of an aqueous composition containing an inert filler.

Inert fillers used in the present invention include barium sulfate,
Examples include titanium oxide, metal powder (eg Fe, TiZr), glass powder, cellulose powder, clay, calcium carbonate and any mixtures thereof, with barium sulfate being particularly preferred. The particle size of the inert filler is usually about 100μ
If the size is too large, it becomes difficult to produce microcapsules of a desired size.

The amount of the inert filler to be added depends on the type of filler and is not particularly limited, but it is usually about 5 to 100% by weight, preferably about 100 to 250% by weight per 100% of water.
It is.

The aqueous composition containing an inert filler is generally and preferably prepared in the form of a paste, but if desired, it may be prepared into a dispersion, suspension, etc. by adding an appropriate dispersion stabilizer.

The method for microencapsulating the above-mentioned inert filler-containing aqueous composition is not particularly limited, and methods commonly used for microencapsulation in other fields, such as in-liquid curing coating method, interfacial polymerization method, 1 nsitu polymerization method, etc. A phase separation method or the like may be used.

The wall material of microcapsules is usually alginate,
Other wall materials such as, but not limited to, polyamide, such as polyester epoxy resin,
Polyvinyl alcohol, amine resin, etc. may also be used.

The particle size of the microcapsules of the aqueous composition containing an inert filler is also not particularly limited, but is usually about 0.01 to 10 m1.
Preferably, it is about 0.005 to 0.5 mi; if the particle size is too large, the microcapsules may be damaged at once when they are disassembled, and the internal liquid may be slightly sprayed out. Moreover, if it is too small, freezing and solidification may be hindered.

Examples of the liquid rubber to be mixed with the above-mentioned microcapsules include silicone rubber, polybutadiene rubber, and polyisoprene rubber, but silicone rubber or polybutadiene rubber is preferred from the viewpoint of rebound resilience.

The amount of microcapsules to be blended depends on the particle size of the microcapsules, the type of built-in inert filler, the type of liquid rubber, etc., but it is usually about 100 to 5 to 100 parts of rubber.
00% by weight, preferably about 100-250% by weight. If the amount of microcapsules blended is too large, there is a risk that the microcapsules will be destroyed by repeated strong blows, or the liquid will be ejected during disassembly. Moreover, if it is too small, it will not become sufficiently hard at low temperatures, making it impossible to easily wrap rubber thread around it.

A core for a thread-wound golf ball according to the present invention is obtained by placing the microcapsule-containing liquid rubber in a predetermined mold and curing it by heating, thereby obtaining a novel thread-wound golf ball.

Next, the present invention will be explained by examples.

Examples Example 1 Microcapsules were prepared by dropping a paste prepared according to the following formulation into an aqueous sodium alginate solution through an orifice while stirring (submerged curing coating method).

Ingredients Parts by weight Water 100 Barium sulfate 140 Titanium oxide 50 Clay 20 Calcium chloride 6 Microcapsules recovered from an aqueous sodium alginate solution by centrifugation were mixed with liquid silicone rubber (
Mixing weight ratio: Microcapsule: Liquid silicone rubber-5
:l). Liquid silicone rubber containing microcapsules was placed in a spherical mold (diameter 29 m) and cured by heating (100°C).
, 10 minutes) to obtain a golf hole core (diameter: approximately 29 ml, weight: approximately 179 ml).

The obtained core was covered with a balata cover in a conventional manner to obtain a golf hole core having a diameter of 1.68 inches.

The golf balls manufactured in this way have no inferiority in terms of hitting feel and flight performance compared to golf balls coated with balata covers of the same diameter made using conventional liquid cores, and are Even when the inside of the core was cut, no liquid spewed out from the core.

Effects of the Invention In the thread-wound golf ball manufactured using the core according to the present invention, the micro-encapsulated liquid phase is isolated and dispersed in the solid core. Not only does it provide a good impact feel and stable flight performance, but it also has excellent impact resistance and safety, as the liquid phase will not spout out even if an excessive impact is applied to the core or the core is cut with a knife, etc. Are better.

Further, in the manufacturing process of thread-wound golf balls using the core according to the present invention, complicated processes unlike those required when using conventional liquid cores are not required, and productivity is significantly increased.

Furthermore, since the core according to the present invention is easily solidified at a temperature below the freezing point of the liquid phase consisting of an aqueous composition containing an inert filler, it has excellent rebound properties that have not been available in solid cores of conventional thread-wound golf balls. Silicone rubber, polybutadiene rubber, etc. can be used, and the ball's rebound properties are also improved.

Claims (1)

[Claims] 1. Microcub packelle of aqueous composition containing inert filler? A thread-wound golf ball core made by hardening a liquid comb containing a comb. 2. The thread-wound golf according to item 1, wherein the inert filler is a mixture of one or more selected from the group consisting of barium sulfate, titanium oxide/metal powder, glass powder, cellulose powder, clay, and calcium carbonate. Core for balls. 3. The thread-wound golf ball core according to item 1, wherein the liquid rubber is silicone rubber, polybutadiene rubber, or any mixture thereof. 4. The particle size of the microcapsules is approximately 0. oI~1. Off
The core for a thread-wound coil pole according to item 1.