GB2133701A - Golf ball - Google Patents

Abstract

The present invention relates to a two-piece coloured golf ball comprising a coating of clear paint (3) only on the cover layer (2) which is blended with a fluorescent pigment. <IMAGE>

Description

SPECIFICATION Golf ball The present invention relates to a coloured golf ball having a two-piece structure, particularly to a golf ball with the coloured cover thereof not coated with a colour paint.

Conventional coloured golf balls are produced by coating the white cover or coloured cover with a colour paint, stamping a mark and then applying a clear paint for finishing. It was however very difficult to match the colour of the cover to that of the colour paint.

Consequently, owing to cracks caused on iron shots by the grooves in the club face (generally, called chinking phenomenon), coloured golf balls produced a colour difference between the parts having the paint peeled therefrom and the parts having the paint still attached thereto, thereby markedly spoiling their appearance. That is, conventional coloured golf balls are chunk quite badly during play, and this is a serious problem to two-piece golf balls.

Generally, the coloured paint is blended with a fluorescent pigment in order to give a colour and lustre to the appearance of golf balls, but the underlying coloured cover is not blended with a fluorescent pigment because it gives no effect on the appearance. And, a need for blending said pigment has not been taken into account at all.

In order to improve the defect described above, in the present invention the colour paint coating, which is one of the causes of the chinking phenomenon, is omitted, and in place of this, the colour rubber is blended with a fluorescent pigment. As a result, there are obtained two-piece coloured golf balls which are not different in appearance from conventional colour paint-coated golf balls, but which are free from the chinking phenomenon.

According to the present invention, there is provided a two-piece coloured golf ball comprising a coating of clear paint on the cover layer which is blended with a fluorescent pigment.

The fluorescent pigment used in the present invention includes for example ZnS-Cu, ZnS-Ag, etc., but it is not limited thereto.

The amount of fluorescent pigment used may be preferably 3 to 6 weight % based on the total weight of the cover layer components. When the amount is less than 3%, the appearance of golf balls is poor, while with amounts more than 6%, a further effect cannot be expected.

The cover layer may be blended, in addition to the fluorescent pigment, with organic or inorganic colour pigments so far commonly used in it, but preferably, it is coloured with the fluorescent pigment only.

For blending the fluorescent pigment, commonly used methods such as by means of calender rolls may be used.

The cover composition thus obtained is generally coated onto a solid core. Generally, the core is placed in two pieces of a hemispherical shell produced from the above cover composition, followed by heat compression molding on a golf ball mold or injection molding with the melted cover composition.

On directly coating the moulded product thus obtained with a clear paint, a coloured golf ball as shown, by way of example, in Figure 1 is obtained. In the Figure, (1) is a core, (2) is a cover layer and (3) is a clear paint layer.

On comparison with the prior art golf ball shown in Figure 2, the colour paint coating layer (4) is not present in the golf ball of the present invention, so that the coating step is not needed, which means greater economy in terms of production and also that the chinking phenomenon is not caused.

The present invention is illustrated in more detail with reference to the following example and comparative examples.

Examples and comparative examples The appearance of golf balls after iron shots was examined using the golf balls of the following comparative examples and example.

Comparative example 1 A two-piece golf ball comprising coating an orange pigment-coated cover with a colour paint containing 2 parts by weight of an orange fluorescent pigment, and coating an urethane clear paint onto said colour paint film layer.

Comparative example 2 A two-piece golf ball produced in the same manner as in Comparative example 1 except that a white cover was used in place of the orange pigment-coloured cover.

Example Atwo-piece golf ball comprising blending the cover with 4 parts by weight of an orange fluorescent pigment and coating an urethane clear paint onto said cover.

The material and properties of the golf balls described above were as Table 1.

TABLE 1 Comparative Comparative Example example 1 example 2 Cover compounding Surlyn 1707 Surlyn 1707 Surlyn 1707 (R.T.M.) Cover-colouring Fluorescent Inorganic Inorganic agent pigment pigment pigment (TiO2) Amountofcover- 4wt.% 2wt.% 2wt.% colouring agent Diameter of innercore 37.1 0 37.1 37.1 pr (mm) Weight of ball 45.1 45.1 45.1 Hardness of ball 100 99 99 (PGA) The above balls were repeatedly shot at a head speed of 35.1 + 0.3 m/sec using a No.9 iron fixed to a swing robot (produced by True Temper CO.), and the appearance thereafter was examined.

As a result, the coloured golf ball of comparative example 2 had the worst appearance since the underlying white colour at the parts wherein the chinking phenomenon was caused were visible at the surface. In Comparative example 1, the appearance was bad since a colour difference was observed although the underlying layer also was coloured. With the ball of Example 1, there was no problem of appearance because of no colour difference being observed.

Claims (3)

1. A two-piece coloured golf ball with a coating of clear paint only on the cover layer which is blended with a fluorescent pigment.

2. A two-piece coloured golf ball according to Claim 1 wherein the fluorescent pigment has 3 to 6 parts by weight of the total weight of the cover layer components.

3. A two-piece coloured golf ball substantially as hereinbefore described with reference to and as shown in Figure 1 of the accompanying drawings.