JP2008079669A - Golf ball material and golf ball using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf ball material excellent in rigidity, impact resilience and durability, and a golf ball which is manufactured by using the same and is excellent in a carry, a ball hitting feeling and durability. <P>SOLUTION: The golf ball material comprises: 60 to 96.7 pts.wt. of ionomer (A) composed by neutralizing the carboxyl group of an ethylene-(meta) acrylic acid copolymer by metal ions for 20-90%; 0.3 to 10 pts.wt. of an ethylene or α-olefin copolymer containing glycidyl (meta) acrylate or glycidyl unsaturated ether or a terpolymer containing vinyl ester or unsaturated carboxylic acid ester (B); and 3 to 30 pts.wt. of polyolefine (C). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a golf ball material and a golf ball using the same.
More specifically, a golf ball material capable of providing a golf ball that is excellent in rigidity, impact resilience, durability, maintains a good shot feeling, and has an extended flight distance compared to conventional products, and the use thereof Related to golf balls.

Conventionally, various ionomers have been proposed and widely used as skin materials for golf balls because of their good durability.
In general, the harder the ionomer, the better the impact resilience and the lower the spin rate. Therefore, hard ionomers have been used to increase the flight distance of golf balls.
However, there is a limit to hardening the ionomer alone, mainly due to its various workability and various characteristics required for golf balls, and attempts have been made to improve them by blending other materials with the hard ionomer. It was.

For example, Patent Document 1 discloses a golf ball comprising a composition obtained by blending an ethylene / unsaturated carboxylic acid copolymer metal ion ionomer with a chlorinated ethylene copolymer crosslinked alloy, and having excellent controllability of the product ball. A material is disclosed.
However, in recent years, there has been a strong demand for further extending the flight distance without impairing the controllability or feel at impact of a golf ball.
As one of the measures for coping with the above-mentioned demand, a method of blending a hard material with a hard ionomer is conceivable, thereby achieving a low spin of the golf ball and an expected flight distance extension.
However, in the past, almost all of the hard materials used in this method lost the excellent properties of the ionomer in the resulting composition. For example, the ball hits the ball by repeatedly hitting it with reduced durability. This led to a new disadvantage in that it was easy to generate cracks and cracks.

Japanese Patent Laid-Open No. 11-244420

In view of such circumstances, the present inventors satisfy the above-mentioned demand for further extending the flight distance without impairing ball controllability, feel at impact, and the like, which is an excellent feature of ionomer resin golf balls. Intensive research was conducted to develop a golf ball material that retains durability such as wear resistance and cut resistance.
And in that process, to clear all the above-mentioned problems required for golf balls and to further increase the flight distance of the balls, we know that rigidity is important as well as the rebound resilience of the materials. As a result of further research, the inventors have found that a composition having desired performance can be obtained when a specific amount of an ethylene copolymer and a polyolefin described below are blended with a specific hard ionomer, thereby completing the present invention. It came to.

Accordingly, an object of the present invention is to provide a golf ball material excellent in rigidity, impact resilience, and durability.
Furthermore, an object of the present invention is to provide a golf ball having excellent flight distance, feel at impact, and durability.

  The golf ball material according to the present invention comprises an ionomer (A) 60 to 96.7 parts by weight obtained by neutralizing a carboxyl group of an ethylene / (meth) acrylic acid copolymer with a metal ion by 20 to 90%, glycidyl (meta ) Ethylene or α-olefin copolymer containing acrylate or glycidyl unsaturated ether, or ternary copolymer (B) further containing vinyl ester or unsaturated carboxylic acid ester, and polyolefin ( C) It is characterized by comprising 3 to 30 parts by weight.

In the golf material, it is preferable that at least a part of the metal ions in the ionomer (A) is a monovalent metal ion.
The golf material is also preferably one in which at least a part of the metal ions in the ionomer (A) is a divalent metal ion.
The polyolefin is preferably a propylene / α-olefin copolymer.
Further, ethylene or α-olefin copolymer containing glycidyl (meth) acrylate or glycidyl unsaturated ether, or terpolymer (B) and polyolefin (C) further containing vinyl ester or unsaturated carboxylic acid ester What was obtained by melt-mixing the molten mixture of the above and the ionomer (A) is preferable.

The golf ball material according to the present invention preferably has a bending rigidity (Olsen type (JIS K 7106)) of 200 MPa or more.
The golf ball material according to the present invention preferably has a Shore D hardness (JIS K 7215) of 50 or more.
Further, the impact resilience (based on JIS K 6301) is preferably 50% or more.

  The golf ball according to the present invention is characterized in that the golf ball material is included in any or all of a skin material, an intermediate layer, and a core material.

According to the present invention, an ethylene / (meth) acrylic acid copolymer ionomer has excellent rigidity, rebound resilience, and durability by blending a specific amount of a specific copolymer containing a glycidyl monomer unit and a polyolefin into an ionomer. Golf ball material can be provided.
Furthermore, a golf ball containing this golf ball material as a skin material and / or a core material is excellent in flight distance, feel at impact, and durability.

In the ionomer (A) used in the present invention, the carboxyl group of the ethylene / (meth) acrylic acid copolymer is neutralized by 20 to 90 mol%, preferably 30 to 85 mol%, with metal ions.
The (meth) acrylic acid content of the ethylene / (meth) acrylic acid copolymer used as the base polymer is a copolymer of 2 to 30% by weight, preferably 3 to 25% by weight. Not only a binary copolymer of an acid but also a multi-component copolymer in which other monomers are arbitrarily copolymerized may be used.
When a copolymer ionomer having an acid content less than the above range is used, it is difficult to obtain a golf ball material having excellent rigidity and impact resilience and excellent flight distance.

Other monomers that may be optionally copolymerized include vinyl acetate, vinyl esters such as vinyl propionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, and n-butyl acrylate. Illustrative examples include unsaturated carboxylic acid esters such as isooctyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, dimethyl maleate and diethyl maleate, carbon monoxide and sulfur dioxide. Can do.
These other monomers may be copolymerized in the range of, for example, 0 to 40% by weight, preferably 0 to 30% by weight. Generally, when the content of such other monomers increases, Since it is difficult to obtain a composition having excellent rigidity, it is preferable to use a composition that does not contain such a monomer or is copolymerized in an amount of 20% by weight or less. preferable.

It is desirable to use such an ethylene / (meth) acrylic acid copolymer having a melt flow rate at 190 ° C. and a load of 2160 g of 1 to 1000 g / 10 minutes, particularly about 2 to 800 g / 10 minutes.
Such a copolymer can be obtained by radical copolymerization under high temperature and high pressure.

As the ionomer (A), 20 to 90 mol%, preferably 30 to 85 mol% of the carboxyl group of the copolymer is neutralized with metal ions.
Here, the metal ion may be an alkali metal such as lithium, sodium or potassium, an alkaline earth metal such as magnesium or calcium, a divalent metal such as zinc, or a combination of several kinds of metals.

  In view of moldability, mechanical properties, miscibility with other components, etc., the ionomer has a melt flow rate of 0.01 to 100 g / 10 min at 190 ° C. under a load of 2160 g, particularly 0.1 to 50 g / 10. It is preferred to use the one in minutes.

  Ethylene or α-olefin copolymer containing glycidyl (meth) acrylate or glycidyl unsaturated ether, (ethylene copolymer containing glycidyl (meth) acrylate or glycidyl unsaturated ether) or glycidyl (meta In the terpolymer (B) containing an acrylate or glycidyl unsaturated ether) or further containing a vinyl ester or an unsaturated carboxylic acid ester, the α-olefin copolymer is: An α-olefin copolymer having about 3 to 8 carbon atoms such as propylene and 1-butene can be exemplified, and an ethylene copolymer is particularly preferable.

  Examples of glycidyl (meth) acrylate or glycidyl unsaturated ether (hereinafter sometimes simply referred to as glycidyl monomer) include glycidyl acrylate, glycidyl methacrylate, vinyl glycidyl ether, allyl glycidyl ether, and 2-methylallyl glycidyl ether. .

The copolymer of ethylene or α-olefin and the above glycidyl monomer does not need to be a binary copolymer, but is a multicomponent copolymer obtained by copolymerizing other monomers such as vinyl ester and unsaturated carboxylic acid ester. It may be a coalescence.
Specific examples of these other monomers include those already exemplified as other monomers in the ethylene / (meth) acrylic acid copolymer which is the base polymer of the ionomer (A).
In the present invention, a ternary or higher multi-component copolymer containing ethylene, an α-olefin, and the glycidyl monomer may be used.

In the copolymer (B) of ethylene (or α-olefin) and glycidyl monomer, ethylene or α-olefin is 50 to 99 wt%, particularly 52 to 98 wt%, glycidyl monomer is 0.5 to 20 wt%, particularly It is preferably 1 to 18% by weight, and the above-mentioned other monomers are copolymerized in the range of 0 to 49.5% by weight, preferably 0 to 40% by weight.
If the glycidyl monomer content is too small, the improvement in durability is not remarkable, while if the amount is too large, the reaction with the ionomer becomes too strong, the resin viscosity increases rapidly, and molding becomes difficult, In addition, there may be a problem in processing performance such as generation of gel in the composition.

Such a copolymer may be a random copolymer or a graft copolymer, but it is generally preferable to use a random copolymer in view of the uniformity of the reaction with the ionomer.
Such a random copolymer can be obtained, for example, by radical copolymerization under high temperature and high pressure.

  When an ethylene copolymer is used as the copolymer, a melt flow rate at 190 ° C. and a load of 2160 g is 0.01 to 1000 g / 10 minutes, particularly 0.1 to 200 g / 10 minutes. Is preferred.

In the present invention, polyolefin (C) is used together with ionomer (A), ethylene or α-olefin / glycidyl monomer copolymer (B).
By using a specific amount of such a polyolefin, a resin composition excellent in dispersibility with other components and excellent in rigidity, durability and the like can be easily obtained.

The polyolefin (C) used in the present invention is an α- having about 2 to 12 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene and 4-methyl-1-pentene. These are olefin homopolymers, mutual copolymers, and the like, and those produced by various methods using various catalysts can be used.
Further, it is preferable to use one having a melting point of 200 ° C. or lower, particularly 180 ° C. or lower.

Preferable examples of the polyolefin (C) of the present invention include an ethylene homopolymer or an ethylene / α-olefin copolymer mainly composed of ethylene.
These are collectively called polyethylene.
As polyethylene, what was manufactured using the metallocene catalyst is preferable.
Among them, an ethylene / α-olefin copolymer mainly composed of ethylene having a density of 870 to 930 kg / m ³ , preferably 880 to 920 kg / m ³ , a melt flow rate at 190 ° C. and a load of 2160 g of 0.1 -100 g / 10 min, preferably 0.2-80 g / 10 min.
The α-olefin in the ethylene / α-olefin copolymer is preferably one having 4 to 12 carbon atoms, particularly about 5 to 10 carbon atoms.

The ethylene / α-olefin copolymer preferably has a weight average molecular weight / number average molecular weight (MWD) of 2.5 or less, particularly 2.0 or less.
It is preferable to use a composition having a composition distribution width index (CDBI) of 50% or more, particularly 70% or more.
Such a copolymer is disclosed, for example, in JP-T-6-509528.
Other preferable ethylene / α-olefin copolymers include those having a melt flow ratio (I ₁₀ / I ₂ ) of 5.63 or more, particularly 7 to 20.
Examples of such copolymers are disclosed in WO95 / 00857.

Another preferred example of the polyolefin (C) of the present invention is a propylene / α-olefin copolymer.
The propylene / α-olefin copolymer is a copolymer of propylene mainly composed of propylene and other α-olefin, and has a density of 870 to 930 kg / m ³ , particularly 880 to 920 kg / m ³ . Further, those having a melt flow rate at 230 ° C. and a load of 2160 g of 0.1 to 100 g / 10 min, particularly 0.2 to 80 g / 10 min are preferable.

  The α-olefin copolymerized with propylene in the propylene / α-olefin copolymer is preferably one having 2 or 4 to 12 carbon atoms, particularly 2 or 4 to 10 carbon atoms, specifically ethylene, Examples thereof include one or more of 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and the like.

The propylene / α-olefin copolymer may be a random copolymer or a block copolymer.
A particularly suitable random copolymer is a random copolymer of propylene and ethylene having a propylene content of 85 to 99.9% by weight, preferably 90 to 99.5% by weight, or propylene, ethylene and other α-olefins. It is a random copolymer consisting of.
These are preferably crystalline polymers copolymerized in the presence of a stereospecific catalyst.

The block copolymer that can be used as a propylene / α-olefin copolymer is obtained by sequentially polymerizing or copolymerizing propylene and another α-olefin, and is generally (1) after polymerization of propylene. It is carried out by combining one or more polymerization steps consisting of (2) copolymerization of propylene and a slightly larger amount of α-olefin and / or (3) polymerization of α-olefin.
In the polymerization of propylene of (1) above, a small amount of α-olefin may be copolymerized, and in the polymerization of (3) α-olefin, a small amount of propylene may be copolymerized.
In any case, the block polymer can be obtained by the multistage polymerization in the presence of a stereospecific catalyst.
A suitable propylene / α-olefin block copolymer is a block copolymer of propylene and ethylene containing about 60 to 95% by weight of the propylene polymer block (1).

  The blending ratio of each component (A), (B), (C) in the thermoplastic resin composition of the present invention is such that when the total amount is 100 parts by weight, the ethylene / (meth) acrylate metal ion ionomer ( A) is 60-96.7 parts by weight, ethylene such as ethylene / glycidyl (meth) acrylate copolymer or α-olefin / glycidyl monomer copolymer (B) is 0.3-10 parts by weight, propylene / ethylene The polyolefin (C) such as a copolymer is 3 to 30 parts by weight, more preferably (A) is 73 to 95.5 parts by weight, (B) is 0.5 to 7 parts by weight, and (C) is 4 to 20 parts by weight. More preferably, (A) is 81 to 94 parts by weight, (B) is 1 to 4 parts by weight, and (C) is 5 to 15 parts by weight.

The thermoplastic resin composition of the present invention can be obtained by melt-mixing ionomer (A), ethylene or α-olefin / glycidyl monomer copolymer (B) and polyolefin (C).
In melt mixing, a normal mixing device such as a screw extruder, a roll mixer, a Banbury mixer, or the like can be used.
Melt mixing can be carried out by blending the above three components at the same time, but the most preferable method is to melt and mix (B) and (C) in advance and (A).
According to this method, since (B) is diluted to (C) and the reaction with (A) does not occur locally and becomes uniform, a composition having excellent properties can be obtained with good quality stability. There is an advantage that it can be manufactured.
If (A) and (B) are first melt-mixed and then (C) is mixed, gelation may occur due to a local reaction.

The resin composition for a golf ball material of the present invention thus obtained is blended with the glycidyl monomer copolymer (B), so that, for example, a screw extruder, a roll mixer, a Banbury mixer, etc. In the melt mixing process using a mixing device, the component (B) diluted in the component (C) undergoes a partial crosslinking reaction while being dispersed in the component (A), and finally, the component (B), It is presumed that the fine dispersion composed of the component (C) has a partially crosslinked bond in the component (A) matrix and is uniformly finely dispersed.
Therefore, the resin composition for a golf ball material of the present invention is thermoplastic despite having a cross-linked bond, and is easy to be thermoformed such as granulated pelletization or golf ball molding.
In addition, it has high rigidity and impact resilience, and is excellent in flight distance and feel at impact as a golf ball.

Other polymers and various additives can be blended with the resin composition of the present invention within a range not impairing the object of the present invention.
Such other polymers and various additives can be blended in a proportion of, for example, 10 parts by weight or less with respect to 100 parts by weight in total of the above (A), (B), and (C).
Examples of the additives include antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, pigments, dyes, lubricants, antiblocking agents, antistatic agents, antifungal agents, antibacterial agents, flame retardants, and flame retardants. Auxiliaries, crosslinking agents, crosslinking aids, foaming agents, foaming aids, inorganic fillers, fiber reinforcements and the like can be mentioned.

The golf ball material according to the present invention preferably has a bending rigidity (Olsen type (JIS K 7106)) of 200 MPa or more.
The golf ball material according to the present invention preferably has a Shore D hardness (JIS K 7215) of 50 or more.
The golf ball material according to the present invention preferably has a rebound resilience (based on JIS K 6301) of 50% or more.

The golf ball material described above can be used as a skin material, intermediate layer, or core material of a golf ball such as a wound ball or a solid ball.
Examples of the solid ball include a one-piece ball or a two-piece ball, and a multi-piece ball such as a three-piece or a four-piece.

  The golf ball material according to the present invention achieves a high hardness with a bending rigidity of 200 MPa or more and a Shore D hardness of 50 or more, and also has a high impact resilience (based on JIS K 6301) of 50% or more. Since this golf ball material is used for any or all of the surface material, intermediate layer, and core material of a golf ball, a golf ball having excellent flight distance, feel at impact, and durability can be obtained. .

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
In addition, the composition and physical properties of the raw materials used in Examples and Comparative Examples and the measurement methods of the physical properties of the obtained sheets are as follows.

1. Ingredients (1) Ionomer (A)
Ionomer 1:
Base polymer: ethylene / methacrylic acid copolymer (methacrylic acid content 15% by weight)
Metal cation source: sodium, degree of neutralization: 30 mol%, MFR: 2.8 g / 10 min. Ionomer 2:
Base polymer: ethylene / methacrylic acid copolymer (methacrylic acid content 15% by weight)
Metal cation source: Zinc, degree of neutralization: 59 mol%, MFR: 0.9 g / 10 min. Ionomer 3:
Base polymer: ethylene / methacrylic acid copolymer (methacrylic acid content 15% by weight)
Metal cation source: Magnesium, degree of neutralization: 54 mol%, MFR: 0.7 g / 10 min (2) α-olefin / glycidyl monomer copolymer (B)
GMA copolymer:
Ethylene / glycidyl methacrylate copolymer (glycidyl methacrylate content: 12% by weight), MFR: 3.0 g / 10 min (3) Polyolefin (C)
Random PP (propylene / ethylene random copolymer) (manufactured by Prime Polymer, F-219DA, density 910 kg / m ³ , MFR 8.5 g / 10 min (230 ° C.))

2. Physical property measurement method (1) Bending rigidity (Olsen type) _Bending rigidity (Olsen type) was measured according to JIS K7106. _ (2) Shore D hardness_ Shore D hardness was measured according to JIS K7215.
(3) Rebound resilience_ The rebound resilience was measured according to JIS K6301.

(Example 1)
83 parts by weight of ethylene / methacrylic acid copolymer ionomer (A) (ionomer 1), 2 parts by weight of α-olefin / glycidyl monomer copolymer (B) (GMA copolymer), and polyolefin (C) (random PP) ) 15 parts by weight is fed to a 30 mmφ twin screw extruder [manufactured by Ikegai Co., Ltd., product number PCM30-35-3V-1SF] with a pelletizer by a predetermined amount, and the following extrusion conditions (or melt kneading) Conditions) was kneaded and granulated to obtain pellets.
Extrusion conditions in the above twin screw extruder are as follows. _ L / D: 35_ barrel temperature (° C);
C1 (160), C2 (190), C3 (210), C4-C9 (210), A (210), D (210)
Screw rotation speed: 200 rpm_ Amount of extrusion: 10 kg / h_ The obtained golf ball material had an MFR (JIS K7210, 190 ° C., 2.16 kg load) of 0.1 g / 10 min.

Next, the obtained pellets were press-molded with a press molding machine set at 160 ° C. to produce a 150 mm square sheet. _ The bending stiffness, hardness, and impact resilience of the obtained press sheet were measured.
The results are shown in Table 1.

(Example 2)
The same procedure as in Example 1 was conducted except that ionomer 1 was changed to ionomer 2 in Example 1.
The results are shown in Table 1.

(Example 3)
The same procedure as in Example 1 was performed except that ionomer 1 was changed to ionomer 3 in Example 1.
The results are shown in Table 1.

Example 4
In Example 1, it carried out like Example 1 except having changed the compounding quantity of the GMA copolymer into 1 weight part.
The results are shown in Table 1.

(Example 5)
In Example 1, it carried out like Example 1 except having changed the compounding quantity of the GMA copolymer into 0.5 weight part.
The results are shown in Table 1.

(Comparative Example 1)
In Example 1, it carried out like Example 1 except having used the ionomer 2 single-piece | unit.
The results are shown in Table 1.

Claims (9)

  Contains 60-96.7 parts by weight of ionomer (A) in which carboxyl group of ethylene / (meth) acrylic acid copolymer is neutralized 20 to 90% with metal ion, glycidyl (meth) acrylate or glycidyl unsaturated ether Ethylene or α-olefin copolymer, or ternary copolymer (B) further containing vinyl ester or unsaturated carboxylic acid ester (B) 0.3 to 10 parts by weight and polyolefin (C) 3 to 30 parts by weight A golf ball material characterized by the above.   The golf ball material according to claim 1, wherein at least a part of the metal ions in the ionomer (A) is a monovalent metal ion.   The golf ball material according to claim 1, wherein at least a part of the metal ions in the ionomer (A) is a divalent metal ion.   The golf ball material according to claim 1, wherein the polyolefin is a propylene / α-olefin copolymer.   Melting of ethylene or α-olefin copolymer containing glycidyl (meth) acrylate or glycidyl unsaturated ether, or terpolymer (B) and polyolefin (C) further containing vinyl ester or unsaturated carboxylic acid ester 2. The golf ball material according to claim 1, wherein the mixture and the ionomer (A) are obtained by melt mixing.   6. The golf ball material according to claim 1, wherein a flexural modulus (Olsen type (JIS K 7106)) is 200 MPa or more.   The golf ball material according to claim 1, which has a Shore D hardness (JIS K 7215) of 50 or more.   The golf ball material according to claim 1, having a rebound resilience (based on JIS K 6301) of 50% or more.   A golf ball comprising the golf ball material according to claim 1 in any or all of a skin material, an intermediate layer, and a core material.