JPS6029156A - One-piece 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] TECHNICAL FIELD This invention relates to one-piece golf balls.

Conventionally, commonly used golf balls include a thread-wound golf ball with a three-layer structure consisting of a center ball, a rubber thread layer, and a cover, and a two-piece golf ball with a center ball and a cover. It has been widely used recently because it is less likely to break and has a good flight distance.

However, both golf balls require time and effort to manufacture, resulting in high costs.

On the other hand, one-piece balls are made by mixing fillers such as barium sulfate, calcium carbonate, and talc with cover materials such as natural balata, transpolyisoprene, ionomer resin, polyurethane, and polyamide, instead of making the center ball and cover separately. Since the manufacturing cost is low, attempts have been made to manufacture it, but it has not been possible to obtain a ball with a well-balanced impact characteristics (speed of return of the deformed ball after impact), rebound resilience, and specific gravity.

The inventors of the present invention have conducted various studies in order to obtain a one-piece pole with well-balanced rebound, impact characteristics, and specific gravity. As a result, they have mixed polyester elastomer with polyurethane elastomer, and added an inorganic filler such as glass beads to this. The present invention was developed based on the finding that a one-piece pole molded from a material containing the following has a well-balanced rebound, impact characteristics, and specific gravity.

That is, the present invention uses polyurethane distomers 10 to 7.
0% by weight and polyester elastomer 30-90% by weight
5 to 30 parts by weight of an inorganic filler to 100 parts by weight of a mixture consisting of
This is a one-piece golf ball made by injection molding a seven-layer composition containing a heavy grain.

The polyurethane elastomer used in the present invention is obtained by reacting a polyester or polyether with a low degree of polymerization, which has hydroxyl groups at both ends, with an excess amount of organic diisocyanate, and the end groups are inocyanate groups. It is obtained by reacting a prepolymer with water, a relatively low molecular weight polyfunctional active water-volume compound such as diamine, diol, etc. as a chain extender.

Specific examples of polyesters or polyethers include polyesters with terminal hydroxyl groups obtained by polycondensation of dicarboxylic acids such as adipic acid and sebacic acid and aliphatic glycols such as ethylene glycol, propylene glycol, butylene glycol, etc. Polyesters with terminal hydroxyl groups such as polycasilolactone obtained by ring-opening polymerization of cap lactones, polyethers such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc., dicarboxylic acids of lactones and cyclic nitrogen, and diethylene glycol, triethylene glycol. Examples include polyether ester glycols having terminal hydroxyl groups obtained by polycondensation with Na.

In addition, as an organic diisocyanate, toluene-2,4-
Diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1-3-phenylene diisocyanate, i, -), +! -Kurorou 1@3-
7 Enylene diinocyanate, 4-butoxy-1,3-
Phenyl diisocyanate, 2,4-diincyanate diphenyl ether, mesitylene diisocyanate,
4,41-methylene-bis(phenylisocyanate)
, shrylene diisocyanate, #5-naphthalene diisocyanate, benzine diisocyanate, o-nitrobenzine diisocyanate, 4,4'-dibenzyl diisocyanate, 1,4-tetramethylene diisocyanate, ■, 6-hedizamethylene diisocyanate, 1・
Examples include 10-decamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, 4,41-methylenebis(cyclohexyfluinocyanate), and 1,5-tetrahydronaphthalene diincyanate.

As a chain extender, ethylene glycol, 1,2-globandiol, 1,4-butanediol, 1,6-hexanediol, ethylenediamine, lI2-propylenediamine, 1,3-propylenediamine, 1,4-tetramethylene Examples include diamine, hexamethylene diamine, m-xylylene diamine, p-xylylene diamine, hydrazine, and the like.

A polyester elastomer to be mixed with the above-mentioned polyurethane elastomer in the present invention! : td, 1.4
- Butanediol is the main glycol component, and other glycols such as ethylene glycol, polyethylene glycol, polytetramethylene glycol, etc. It is a linear polyester obtained by reacting with dimethyl isophthalate (terephthalate, dimethyl isophthalate).

The mixing ratio of polyurethane elastomer and polyester elastomer in the present invention is 20 to 70% by weight of polyurethane elastomer to 4 m'% by weight of polyester elastomer to 30 to 80% by weight of polyester elastomer, preferably 40 to 60% by weight of polyurethane elastomer to 40 to 60% by weight of polyester elastomer. -11 ft%.

If the amount of the polyester elastomer mixed with the polyurethane elastomer is less than 30% by weight, it will take time for the golf ball deformed by impact to return to its original shape, which is undesirable. This is not desirable because it is not sufficient.

In the present invention, an inorganic filler is added to adjust the specific gravity of the ball.

Preferred fillers include glass peas, magnesium oxide, titanium dioxide, hydrated silica, zinc white, barium sulfate, and the like.

The filler is present in an amount of 5 to 30 parts by weight per 100 parts by weight of the polyurethane distomer/polyester elastomer.

The molding composition obtained as described above is uniformly kneaded according to a conventional method and molded using an injection molding machine. The molding temperature is about 150-200°C for 60-180 seconds.

The one-piece golf ball of the present invention has many advantages over conventional one-piece golf balls, such as superior rebound and impact resistance, and a shorter time for the ball to return to its original state after being deformed by impact. .

In addition, the manufacturing cost is lower than the method of manufacturing thread-wound golf balls or two-piece golf balls.

The present invention will be specifically explained with reference to Examples.

Examples 1 to 3, Comparative Examples 1 to 2 One-piece balls were obtained by molding the compositions shown in Table 1 using an injection molding machine at molding conditions of 210 to 220° C. for 60 to 180 seconds.

The results of measuring the physical properties of the obtained one-piece pole are also shown in Table 1.

Table 1 Compression values were obtained using an Ancce compression tester.

The repellency of a golf ball is 150 (from a height of 5 m to a thickness of 5
Let it fall naturally onto a cIrL steel plate, and the height of the bounce is shown in terms of impact.

Durability is determined by dropping a weight of 5ft 9 from a height of 1m to give an impact to the ball, repeating this until cracks appear on the surface of the ball, and taking the number of repetitions as the measured value.

As is clear from the results in Table 1, the one-piece golf balls of Examples 1 to 3 according to the present invention have good repulsion and return characteristics, and are excellent in durability.

On the other hand, the one-piece golf ball of the comparative example had inferior repulsion and return characteristics to those of the example, and did not have sufficient performance as a golf ball.

Claims (1)

[Claims] Blend 1 consisting of 10-70% by weight of polyurethane distomer and 30-90% by weight of polyester elastomer
A one-piece golf ball made by injection molding a composition containing 0.00 parts by weight and 5 to 30 parts by weight of an inorganic filler.