JPS60210272A - 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] This relates to a golf pole that has increased weight and improved flight distance.

High-quality round golf balls include thread-wound three-piece poles and two-piece solinod balls, both of which are covered with covers to protect the core.

There are two types of covers, so-called paratha covers and ionomer covers, which are mainly composed of transpolyisoprene, and these have specific gravity between 0.97 and 1.2.

Golf balls using these paratha covers or ionomer covers have materials of high specific gravity, such as halirum sulfate, in the center for weight adjustment in the case of thread-wound three-piece poles, and in the inner core for two-piece solinod golf balls.
Filled with zinc oxide, calcium carbonate, etc. As a result, the core has low repulsion elasticity and the ball's repulsion performance is poor, and the high specific gravity of the core reduces the moment of inertia, which makes it easier to spin, and the spin decays faster during flight, reducing flight distance. becomes smaller.

The present invention was made in view of such circumstances, and the cover is blended with a high specific gravity filler having a specific gravity of 8 to 20 to increase the specific gravity of the cover. Decrease the amount of filler in
By increasing the repulsion of the core and increasing the moment of inertia of the pole, the initial spin when hitting the pole is reduced.
A golf ball with a long flight distance can be obtained by suppressing spin attenuation during flight.

In addition, since the above-mentioned fillers with a specific gravity of 8 to 20 have a high specific gravity, even if they are blended into the cover, their volume fraction in the cover is low (i.e., the fillers with a specific gravity of 8 to 20 are unlikely to deteriorate the cover properties such as cutability). .

In the present invention, for example, tungsten (specific gravity 19.3) is used as a filler having a specific gravity of 8 to 20 to be blended into the cover.
, Riji Gesten Carbide (specific gravity 15.8), Molybdenum (specific gravity 10.2), Lead (specific gravity 11.3),
Lead oxide (specific gravity 93), nickel (specific gravity 8°9), t
μm (specific gravity: 8.9), red lead (specific gravity: 8.7), etc. These include zinc oxide (specific gravity: 5.55 to 5.65), which has traditionally been blended into covers as a weight adjuster.
), has a higher specific gravity than barium sulfate (specific gravity: 4.47), and even when added to the cover, it requires less volume than the conventionally used zinc oxide or barium sulfate, and as mentioned above, it has excellent cut resistance. The properties required for the cover, such as its properties, are less likely to deteriorate.

In the present invention, the specific gravity of the filler added to the cover is 8 to 8.
The reason why it was set at 20 is that when the specific gravity is less than 8, there is little difference in effectiveness compared to conventionally used zinc oxide and barium sulfate.
This is because, although it has an excellent effect of increasing the specific gravity of hippo, it is expensive and economically impractical. As is clear from the above description, the higher the specific gravity of the filler, the higher the specific gravity of the cover can be with a smaller amount of the filler. Therefore, in the present invention, a filler having a specific gravity of 10 to 20 is particularly used for lamps.

1. The amount of high-density fillers such as tungsten added to the cover varies depending on the type of filler and whether a balata-based cover or an ionomer yarn cover is being prepared. Although it differs depending on whether the core is coated or a solid core is coated, it is preferable to mix the cover so that the specific gravity is 1.1 or more, preferably 1.25 or more, and generally the main phase of the cover is 10.
o Weight part: 20~ for solid core cover
80 parts by weight, 40 to 110 for thread-wound core river cover
It is blended in about parts by weight.

As the main cover material, for example, a balata-based cover uses transpolyisoprene or a blend of transpolyisoprene and natural rubber, and an ionomer-based cover uses an ionomer or an ionomer plus nylon such as nylon 6, nylon 66, or nylon 12. , or a blend of medium and low density polyethylene.

A composition for forming the cover is prepared by mixing the above-mentioned cover main material, the above-mentioned high specific gravity filler such as tungsten, and cover compounding agents.

As the above-mentioned cover compounding agents, for example, white pigments such as titanium dioxide, coloring agents, anti-aging agents, lubricants, dispersants, stabilizers, ultraviolet absorbers, etc. are appropriately selected and used. In particular, when preparing a balata cover composition, sulfur, a vulcanization accelerator, and the like are used as cover compounding agents in addition to those mentioned above.

The above-mentioned cover can be used to cover either a thread-wound core (a core formed by winding a thread rubber around the center under tension) or a solid core.

The preparation of the cover composition and the method for coating the core of the cover can be carried out by conventionally employed suitable methods. For example, the cover composition is prepared by uniformly mixing the cover base material, high specific gravity filler, and desired cover ingredients using a roll, mixer, extruder, etc., and the core is coated by injection molding or compression. This is done by molding.

Further, the thickness of the cover is preferably about 10 to 2.5 mm as in the conventional case.

For the core of a solid golf pole or the center of a thread-wound Corfu ball, the weight increases due to the addition of high specific gravity fillers in the cover, so the amount of filler that was previously added to adjust the weight has been reduced. I can do it.

However, zinc oxide has nine properties that promote co-crosslinking of high-cis-polybutadiene, so in order to obtain a two-piece golf ball with high compression, zinc oxide must be added to 100 parts by weight of high-cis-polybutadiene. It is preferable to incorporate at least 5 parts by weight of.

Next, the present invention will be explained in more detail by giving examples.

Examples 1 to 4 and Comparative Example 1 The ionomers listed in Table 1 were melted and kneaded using a roll, and predetermined amounts of a high specific gravity filler and titanium dioxide were added and mixed. After mixing, extrude into a sheet at 150°
After storage at C, a half shell for a ball was produced using a compression molding method.

The rubber composition shown in Table 1 was vulcanized in a mold at 160° C. for 25 minutes to produce a solid core with an outer diameter of 37.1 mm. In preparing the composition, the weight of the core was adjusted so that the total weight of the golf ball obtained was approximately 45.3 g. The blended parts of the compositions in Table 1 are based on parts by weight for both the cover and the core.

The core obtained in the above manner was covered with the half shell cover, and heated and molded at 155°C for 2.5 minutes using the compression molding method to form straight i-shaped strips.
mm two-piece solid golf hole (M).

Table 2 does not show the results of measuring the physical properties of the golf holes obtained.

As shown in Table 2, the balls of the examples all have a larger repulsion coefficient than the balls of the comparative example. In addition, regarding flight distance, the ball of the example was larger than the hole of the comparative example, and the degree of improvement was estimated from the improvement in the coefficient of repulsion (
+1 m to +2 m>, the effect of increasing the moment of inertia was recognized.

Patent applicant: Sumitomo Rubber Industries, Ltd.

Claims (2)

[Claims] (1) In a golf ball consisting of a core and a cover covering the core, the cover is the main material and has a specific gravity of 8 to 20.
A golf ball characterized in that it is formed from a composition comprising a filler and a cover compound. (2) The golf ball according to claim 1, wherein the filler has a specific gravity of 10 to 20.