JPS6111066A - 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 of the Invention] The present invention provides a wide core compression range (45-15
0) relates to a golf ball that is excellent in flight characteristics (repulsion resilience), feel when hit, and durability.

[Prior art]

Conventionally, rubber compositions for golf ball cores have been prepared by blending polybutadiene with α,β-ethylenically unsaturated carboxylic acids such as methacrylic acid and acrylic acid, and metal oxides such as zinc white. A metal salt of an acid is formed (Japanese Patent Publication No. 55-19615), and a polybutadiene rubber is blended with zinc methacrylate (Japanese Patent Publication No. 53-8).
No. 383) have been proposed. However, with these rubber compositions, the hardness of the golf ball, that is, the compression (force required when compressing 2.54 mm), increases in proportion to the amount of methacrylic acid or acrylic acid blended, and the impact resilience (flying ball) increases accordingly. There is a serious drawback that the distance (tilt) is significantly reduced.

In addition, recently, acrylic acid or methacrylic acid N, N'
- A solid golf ball having a core made of a rubber composition containing phenylene bismaleimide has also been proposed (Japanese Unexamined Patent Publication No. 78876/1983).

However, even in this case, there is a drawback that increasing the combresolution similarly reduces the impact resilience.

By the way, in recent years, the number of people playing golf has increased rapidly, and there is a strong tendency for people of all ages to enjoy playing golf (especially those with slow head speeds (34 m/sec to 37 m/sec)) and young people. In addition, there are many amateur players with speeds in the 50 m/sec class, and it can be said that the head speeds of players range over a very wide range.

Therefore, under these circumstances, it is important to select a golf ball that matches the player's head speed. If a player with a high head speed uses a ball with low compression, the speed ratio will decrease and he will be at a significant disadvantage, so if you take into account the ball release (degree of collapse when hitting) that suits the player's preference, the head speed: J will be faster. The higher the compression, the more a ball with higher compression is required. Also,
For players with slow head speeds, the speed ratio remains the same whether the ball is high or low, so you can choose a ball with the compression that suits you in terms of ball release, etc., but in general, the slower the head speed, the more comfortable the ball will be when hitting. A ball with low compression is required to get the feel.

As described above, conventional balls with a compression of about 100 to 135 are not satisfactory, and there is a long-awaited development of a golf ball with a wide range of compression (70 to 180) that provides excellent flight distance and durability.

[Purpose of the invention]

The present invention was made in view of these circumstances, and has good rebound resilience and feel at impact over a wide range of compression from 70 to 180.
As a result, it is an object of the present invention to provide a golf ball that exhibits excellent flight distance and also has excellent durability.

(Structure of the Invention) Therefore, the present invention provides 5 to 50 parts by weight of urethane acrylate and 5 to 40 parts by weight of bismaleimide to 100 parts by weight of a base rubber containing polybutadiene having 40% or more of cis-1,4-structure. parts, 5 to 50 parts by weight of silicic acid compound,
From a composition containing 10 to 60 parts by weight of a metal compound and 1 to 5 parts by weight of an alkyl peroxide, and in which the total amount of the urethane acrylate, the bismaleimide, and the silicic acid compound is 20 to 100 parts by weight. The gist is a golf ball having a core of:

Hereinafter, the configuration of the present invention will be explained in detail.

(11 Base rubber.

The base rubber used in the present invention is a rubber containing polybutadiene having at least 40%, preferably 90% or more of cis-1,4 structure. If the cis-1,4 structure is less than 40%, flight distance will not be improved and it will be difficult to obtain the sled/7-do golf ball that is the object of the present invention. As this base rubber, it is preferable to use the above-mentioned polybutadiene alone, but if necessary, rubber components conventionally used as base rubber for solid golf balls, such as natural rubber, isoprene rubber, styrene-butadiene rubber, etc. may be blended as appropriate.

(2) Urethane acrylate.

This urethane acrylate is obtained by reacting isocyanates or isocyanate prepolymers with di- or poly(meth)acrylates having hydroxyl groups (
It is a urethane compound containing a meth)acrylate group.

The isocyanate prepolymer in this case is a polyol such as glycol, triol, or tetrol, or a polyether diol, polyether triol, polyester diol, polyester triol, polycaprolactone ester diol, polycaprolactone triol, and a di- or triisocyanate having a molecular weight of 2000 or less. It is a prepolymer having isocyanate groups at the terminals obtained by reacting with.

In addition, isocyanates include, for example, tolylene diisocyanate (80% 2,4-12,6-isomer, 20%
%, 65%, 35%, or 100% of 2.4), 4.4' diphenylmethane diisocyanate, toluidine diisocyanate, xylylene diisocyanate, hydrogenated to these. diisocyanate having a saturated hydrocarbon ring, isophorone diisocyanate, dimer acid diisocyanate, 1.
It is a polyisocyanate polymer obtained from 6-hexamethylene diisocyanate, lysine diisocyanate-1-12,2,4) listyl hexamethylene diisocyanate, polymethylene polyphenylene polyisocyanate, and tolylene diisocyanate.

Di or poly (meth)acrylate having a hydroxyl group is
These include those obtained by reacting acrylic acid or methacrylic acid or their derivatives with a polyhydric alcohol, or those obtained by reacting acrylic acid or methacrylic acid or their derivatives with a compound having an epoxy group. Examples of such di- or poly(meth)acrylates include ethylene glycol mono(meth)acrylate, propylene glycol(meth)acrylate, 1,3-propanediol mono(meth)acrylate, and 1,4-butanediol mono(meth)acrylate. Dihydric alcohols such as acrylate, 1,6 hexanediol mono (meth)acrylate, diethylene glycol mono (meth)acrylate, dipropylene glycol mono (meth)acrylate, polyethylene glycol mono (meth)acrylate, polypropylene glycol mono (meth)acrylate, etc. Mono (meth)acrylate; trimethylolethane mono (meth)7 acrylate, trimethylolpropane mono (meth)acrylate, trimethylolethane bis(meth)acrylate,
Trihydric alcohol mono such as glycerin mono (meth)acrylate and glycerin bis(meth)acrylate
(meth)acrylate; and bis(meth)acrylate, pentaerythritol bis(meth)acrylate,
Examples include bis- or tris-(meth)acrylates of polyhydric alcohols of 4 (illi or more) such as pentaerythritol-lis(meth)acrylate.Furthermore, reaction products of glycidyl(meth)acrylate and aromatic carboxylic acids, or Examples include reaction products of (meth)acrylic acid and phenylglycidyl ether (or phenylglycidyl ether).

Other reaction products of (meth)acrylic acid and a glycidyl compound at a molar ratio of 1:1 may also be used. These reaction products can be specifically represented by the following formula.

R.

1+CH2=C-C00CH2-'CH-CH,,R2
H In the above formula, R1 represents H or C11, and R2 represents an alkyl group, an aryl group, an allyl group, a (meth)acryloyl group, or a derivative thereof.

The above-mentioned di- or poly(meth)acrylate having a hydroxyl group easily reacts with isocyanates to produce urethane acrylate. This reaction is shown by the following formula.

R.

RoH + (J CH2R2 In the above formula, R3 is an alkyl group in the isocyanate layer,
Indicates an allyl group and other substituents.

Furthermore, a urethane acrylate obtained by reacting a glycol or a polyol with a diisocyanate to form an adduct having an isocyanate group and reacting this with the above-mentioned di- or poly(meth)acrylate having a hydroxyl group is used as the urethane acrylate in the present invention. Can be used as acrylate. This urethane acrylate is represented by the following formula.

(n”2 +3) R4 knee R30-CnH2n-0-R3-(n”'2.
4.6.8).

CH2-0-R3-CH2-0-R3-CHOR3+
H3CCCH20Rs +CH20R3CH20
Rs- -R30-CH2+CH2-0R3- Furthermore, an isocyanate group-terminated prepolymer obtained by reacting a polyol with a molecular weight of 2000 or less with a diisocyanate, and the above di- or polyester having a hydroxyl group.
Urethane acrylate obtained by reacting with (meth)acrylate can also be used as the urethane acrylate in the present invention. Here, the reason why the molecular weight is set to be 2000 or less is because if the molecular weight exceeds 2000, the crosslinking density becomes low, and the objective of the present invention (improvement in hardness or modulus) cannot be expected, which is not preferable. The polyols with a molecular weight of 2000 or less used here include polytetramethylene ether glycol, polyoxypropylene glycol, polyoxyethylene propylene glycol, polyethylene adipate glycol, polybutylene adipate glycol, polyethylene propylene adipate glycol, polyethylene terephthalate glycol, polybutylene terephthalate glycol,
Examples include polycaprolactone glycol and copolymers thereof.

This is shown in .

Examples of this compound include N,N'-phenylenebismaleimide, N,N'-methylenebismaleimide, N,N'-methylene-di-p-phenylenebismaleimide, N,N'-oxy- Di-p-phenylenebismaleimide, N,N'-p-diphenylsulfonemaleimide, N,N'-(3,3'-dimethyl)-methylene-di-p-phenylenebismaleimide, N
, N'-mata6yo p-xylene bismaleimide, N,
N'-metatoluidine-di-maleimide and the like can be mentioned.

(4) Silicic acid compound.

Examples of the silicic acid compound include anhydrous silicic acid, hydrated silicic acid, calcium silicate, and aluminum silicate.

Silicic anhydride is Aerosil (trade name), Cab
-0-5il (Product name) +5antocel C
,D,Fine 5ilica (product name),
Fransil 251 (Product name) +Frante
g (product name) etc.

Examples of hydrous silicic acid include Carplex (trade name), Jilton (trade name), Starsil (trade name), Nibseal VN3 (trade name), Himezil (trade name), Vitaseal (trade name), and Old-3i1 (trade name). name), Duro
sil (product name) + 1lltrasilVN3
(Product name), former krosil (Product name) + V
ulkasil (product name), Levilite
(product name).

Calcium silicate is Eyeseal (trade name).

Jiruton R30 (product name), Silmos 8 (product name).

Starex (product name), Solex (product name),
Fricocil (product name), 5ilen EF (product name), Calsi+ (product name), Frant
ex (product name), etc.

The aluminum silicate is Zeolex 23 (trade name).

Fortafil Hachi (product name) and the like.

(5) Metal compounds.

These metal compounds include lithium, sodium, potassium, cesium, silver, and mercury (mercurous and mercurous).
, copper (cuprous and cupric), helium, magnesium, calcium, strontium, barium, cadmium, tin (stannous), lead (ferrous and ferric), iron (ferrous and ferric), cobalt. (II), nickel (It),
Zinc, cobalt (■), aluminum, scandium,
Examples include compounds such as yttrium, especially oxides,
Among them, zinc oxide is preferred.

(6) Alkyl peroxide.

For example, dicumyl peroxide is used, but is not particularly limited. This alkyl peroxide acts as a polymerization initiator or a crosslinking agent.

In the present invention, a composition is prepared in which urethane acrylate, bismaleimide, a silicate compound, a metal compound, and an alkyl peroxide are blended with 100 parts by weight of a base rubber containing polybutadiene having a cis-1,4 structure of 40% or more. The material is used in the core of golf balls.

The blending amount of urethane 7-acrylate is 5 to 50 parts by weight, preferably 10 to 40 parts by weight.

The blending amount of bismaleimide is 5 to 40 parts by weight, preferably 10 to 30 parts by weight.

The blending amount of the silicic acid compound is 5 to 50 parts by weight. This is because if it is less than 5 parts by weight, it has little effect on improving compression and durability, while if it exceeds 50 parts by weight, it has a remarkable effect on improving compression and durability, but it is not preferable because it causes a decrease in impact resilience. .

Furthermore, the total amount of the three components of urethane acrylate, bismaleimide, and silicic acid compound is 20 to 100 parts by weight. If the amount of these three components is less than this amount, the final solid golf ball will be too soft and have poor impact resilience and durability.On the other hand, if the amount of these three components is more than this amount, the resulting solid golf ball will be too soft. This is because it becomes too hard and is not suitable for use as a golf ball.

The blending amount of the metal compound is 10 to 60 parts by weight, but if necessary, a part of it may be added to other fillers such as barium sulfate,
It may be replaced with silica or the like.

The amount of alkyl peroxide blended is 1 to 5 parts by weight.

In order to make a core from the rubber composition obtained as described above, the composition may be uniformly kneaded by a conventional method, heated and vulcanized under pressure, and integrally molded. By covering this core with a cover, a solid golf ball having a double structure can be manufactured. The material of the cover includes balata, polyurethane, nylon, ionomer, etc., but is not particularly limited. Typically, ionomers are used in thicknesses of about 1.0 to 3.0 mm.

The above rubber composition can be used not only for the core of two-piece golf poles, but also for one-piece Corfu poles, three-piece golf balls, and the like.

〔Effect of the invention〕

A golf ball having a core made of the above-mentioned rubber composition obtained by the present invention has both excellent rebound resilience and durability, has appropriate ball hardness, and has physical properties fully comparable to conventional thread-wound golf balls. .

EXAMPLES Hereinafter, the effects of the present invention will be specifically explained with reference to Examples.

EXAMPLES Eleven types of rubber compositions were prepared according to conventional methods according to the formulations shown in Table 1 below.

The obtained rubber compositions 1 to 11 were each press-molded at 160°C for 20 minutes to form a spherical solid core with a diameter of 36.4 mm, and an ionomer (Surlyn 1605.1706 (titanium oxide Two-layer structure solid golf balls A-J were produced, each having a thickness of approximately 2.5 mm and containing 1% of the total amount of solid golf balls A-J. The physical properties of these golf poles are shown in Table 2 below.

As is clear from Table-1 and Table-2, Standard Example 1.3
It can be seen that in a relatively low compression range, good impact resilience is shown, but in Standard Example 2.4, which has a formulation with even higher compression, the impact resilience is significantly reduced.

On the other hand, in Examples 5 to 8, it was found that the decrease in impact resilience was small as the compression increased;
This shows that golf balls with good impact resilience can be obtained over a wide compression range of 0 to 180.

It also has excellent durability and provides a pleasant feel (sound and touch) when hitting.

In Comparative Examples 9 to 11, any one or the total amount of urethane acrylate, bismaleimide, and silicic acid compound is at a blending ratio outside the range of the present invention. Comparative Examples I, J
is outside the compression range of 70 to 180, is either too hard or too soft, and has poor impact feel. Moreover, the comparative example is a rubber composition in which no silicic acid compound is blended, and although the compression and impact resilience are good, the durability is poor.

(Leaving space below) Table 1 (Note) Hata 1 Commercially available polybutadiene rubber (98% cis-1,4 structure) manufactured by Nippon Zeon Co., Ltd.

Standard Examples 3 and 4 are N manufactured by Iruuchi Shinko Kagaku Co., Ltd.

Example 5 containing Nl-phinyl bismaleimide
8. Comparative Examples 9 to 11 are N and N' manufactured by Mitsui Toatsu Chemical Co., Ltd.
-Methylene-P-FlI4 Standard Examples 1 and 2, Example 7
, 8, and Comparative Examples 9 and 10 are those containing Nippon Silica@) Nip Seal 'vN-3.

Examples 5 and 6 are Aerosil 2 manufactured by Nippon Aerosil Co., Ltd.
Contains 00.

(Blank below) As explained above, a golf ball having a core made of a rubber composition obtained by the present invention has excellent flight characteristics (resilience) and feel at impact in a wide compression range (70 to 18 degrees). It has excellent properties and is also extremely durable.

Agent: Patent Attorney Nobuo Kogawa - Kenteru Noguchi Kazuhiko Saishita

Claims (1)

[Claims] 5 to 50 parts by weight of urethane acrylate, 5 to 40 parts by weight of bismaleimide, 5 to 50 parts by weight of silicate compound, metal to 100 parts by weight of base rubber containing polybutadiene having 40% or more of cis 1,4-structure. Compounds 10-60
parts by weight, and 1 to 5 parts by weight of alkyl peroxide, and the total amount of the urethane acrylate, the bismaleimide, and the silicic acid compound is 20 to 5 parts by weight.
A golf ball having a core comprising 100 parts by weight of a composition.