JP2002119614A - Thermoplastic resin composition for golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition for a golf ball wherein the bonding strength and the separating property of a multi-piece golf ball cover material with other layer constituting resins are drastically increased while maintaining performances such as an excellent forming property, a wear- resistance and repulsive elasticity. SOLUTION: This thermoplastic resin composition for the golf ball contains 100 pts.wt. of an aromatic vinyl compound-conjugate diene based compound copolymer, 0 to 240 pts.wt. of a rubber softener, 0 to 100 pts.wt. of a peroxide crosslinking type olefin based resin, 0 to 100 pts.wt. of a peroxide resoluble type olefin based resin, 0 to 30 pts.wt. of a liquid form polybutadiene, 0 to 15 pts.wt. of an unsaturated glycidyl based compound, 0 to 15 pts.wt. of an unsaturated carboxylic acid, 0 to 15 pts.wt. of a (meth)acrylate based compound having a hydroxyl group, and also, 0 to 3.5 pts.wt. of an organic peroxide based on the total of 100 pts.wt. of the above substances, and 1 to 1,500 pts.wt. of ethylene and an ethylene based copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf ball cover material which is excellent in injection moldability while maintaining basic properties required for golf balls, such as rebound resilience and wear resistance, and is compatible with other polar resins. The present invention relates to a thermoplastic composition for golf balls having improved adhesion, release properties and flexibility.

[0002]

BACKGROUND OF THE INVENTION As a cover material for golf balls, ionomer resins are particularly excellent in terms of resilience and scratch resistance.
It is commonly used. Further, in recent multi-piece golf balls, there is an example in which a urethane resin is used for the first cover and an ionomer resin is used for the second cover, which has conventionally used an ionomer resin.

[0003] In addition to the above components, studies have been made on styrene-butadiene-block polymer (SB).
S), styrene / isoprene-block polymer (SI
Polystyrene-based thermoplastic elastomers such as S) and their hydrogenated products are rich in flexibility, have good rubber elasticity at room temperature, and the thermoplastic elastomer compositions obtained therefrom have excellent processability. . However, golf balls formed by these methods have problems in wear resistance and scratch resistance.

[0004]

In order to provide the above-mentioned multi-piece golf ball structure, the adhesive strength and the peeling property of each layer are important. However, the resin that can be selected in each layer is limited, and depending on the combination of the selected resin. However, there has been a problem that the adhesive strength and the peeling property are not sufficient, and the ionomer resin alone has no degree of freedom in hardness, and the adhesiveness to the polyurethane polymer is weak.

Accordingly, the present invention provides another layer structure of a conventional multi-piece golf ball cover material containing an ionomer resin as a main component while maintaining excellent moldability and basic performance of a golf ball such as abrasion resistance and rebound resilience. It is an object of the present invention to provide an excellent effect and a degree of freedom in hardness, which greatly exceed the adhesive strength with resin and the peeling property.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have developed a multi-piece golf ball cover material while maintaining excellent moldability, and abrasion resistance and rebound resilience. Extensive study to obtain a thermoplastic resin composition for golf balls, which has a high degree of freedom in adjusting the hardness of the material, with a drastically improved adhesive strength and peeling property with the layer constituent resin, especially a polyurethane resin or an ionomer resin. 100 parts by weight of at least one copolymer selected from the group consisting of (a) an aromatic vinyl compound-conjugated diene compound copolymer and / or a hydrogenated product thereof;
(B) 0 to 240 parts by weight of a non-aromatic rubber softener;
(C) a peroxide-crosslinked olefin-based resin and / or a copolymer thereof in an amount of 0 to 100 parts by weight, and (d) a peroxide-decomposable olefin-based resin and / or a copolymer thereof in an amount of 0 to 100 parts by weight.
100 parts by weight, (e) 0 to 30 parts by weight of liquid polybutadiene, (f) 0 to 0 parts of unsaturated glycidyl compound or derivative thereof
15 parts by weight, (g) unsaturated carboxylic acid or its derivative 0
0 to 15 parts by weight, (h) 0 to 15 parts by weight of a (meth) acrylate compound having a hydroxyl group, and (j) organic peroxides (a) to (h). 5 parts by weight, (i) ethylene and general formula

Embedded image CH ₂ （C (R1) —COOM (wherein R ₁ represents hydrogen or a methyl group, M represents Na, Z
a thermoplastic resin for a golf ball of the present invention, comprising 1 to 1500 parts by weight of an ethylene copolymer represented by n or a metal or hydrogen) and at least one copolymer selected from the group consisting of the copolymer. A resin composition was obtained.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, each component of the resin composition of the present invention will be described in detail.

(A ) Aromatic vinyl compound-conjugated diene formation
Component copolymer and / or hydrogenated product thereof Component (a) in the present invention comprises (a-1) a block copolymer of an aromatic vinyl compound and a conjugated diene compound, or a hydrogenated product thereof; And / or at least one selected from the group consisting of a random copolymer of an aromatic vinyl compound and a conjugated diene compound, or a hydrogenated product. Examples of the aromatic vinyl compound in the component (a) include styrene, t-butylstyrene, α-methylstyrene, and p
One or more of methyl-styrene, divinylbenzene, 1,1-diphenylstyrene, N, N-diethyl-p-aminoethylstyrene, vinyltoluene, p-tert-butylstyrene, and the like. Styrene is preferred. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene,
One or more kinds are selected from 2,3-dimethyl-1,3-butadiene and the like, and among them, butadiene, isoprene and a combination thereof are preferable.

Component (a-1) a block copolymer, and
Component (a-1) of the present invention comprises at least one polymer block A mainly composed of an aromatic vinyl compound and at least one polymer block B mainly composed of a conjugated diene compound.
And a mixture obtained by hydrogenating the block copolymer, or a mixture thereof, for example, AB, ABA, BABA, AB- A
And an aromatic vinyl compound-conjugated diene compound block copolymer having a structure such as -BA or a hydrogenated product thereof. The (hydrogenated) block copolymer (hereinafter, the (hydrogenated) block copolymer means a block copolymer and / or a hydrogenated block copolymer) is obtained by mixing an aromatic vinyl compound with 5 to 50 parts. % By weight, preferably 20 to 40% by weight. The polymer block A mainly composed of an aromatic vinyl compound is preferably
The content of the aromatic vinyl compound is 50 to 100% by weight, preferably 70% by weight or more. The polymer block B mainly composed of a conjugated diene compound is preferably a conjugated diene compound having 5
It is preferably from 0 to 100% by weight, preferably 70% by weight or more and hydrogenated. It is preferable that at least 70% or more of the aliphatic double bond in the conjugated diene compound is hydrogenated. When there are two or more polymer blocks A mainly composed of an aromatic vinyl compound or two or more polymer blocks B mainly composed of a (hydrogenated) conjugated diene compound, they have different structures even if they have the same structure. There may be.

The weight average molecular weight of the (hydrogenated) block copolymer having the above-mentioned structure and used in the present invention is preferably 5,000 to 1,500,000, and more preferably 1 to 1.
The range is from 0000 to 550,000. The molecular weight distribution (ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn)) is preferably 10 or less, more preferably 5 or less, and more preferably 2 or less. The molecular structure of the (hydrogenated) block copolymer may be linear, branched, radial, or any combination thereof.

A number of methods have been proposed for producing these block copolymers. Typical methods include, for example, a method described in Japanese Patent Publication No. 40-23798, which uses a lithium catalyst or a Ziegler catalyst. It can be obtained by performing block polymerization in an inert solvent using a type catalyst. The hydrogenated block copolymer can be obtained by hydrogenating the block copolymer obtained by the above method in an inert solvent in the presence of a catalyst.

Specific examples of the above (hydrogenated) block copolymer include SBS, SIS, SEBS, SEPS, and SIB.
S and its hydrogenated products can be mentioned. In the present invention, a particularly preferred (hydrogenated) block copolymer is a polymer block A mainly composed of styrene and a polymer block mainly composed of isoprene, and 70 to 100% by weight of isoprene is 1,4-.
Having a weight average molecular weight of 50,000 to 55, comprising a polymer block B having a microstructure and having at least 70% of the aliphatic double bonds based on the isoprene hydrogenated.
It is a 000 hydrogenated block copolymer. More preferably, 90 to 100% by weight of isoprene is the above hydrogenated block copolymer having a 1,4-microstructure.

Component (a-2): a random copolymer, and / or
The hydrogenated product of the component (a-2) random copolymer of the present invention is a random copolymer of a conjugated diene compound and 50% by weight or less of an aromatic vinyl compound, and has a number average molecular weight of not more than 50% by weight. 5,000 to 1,000,000, a value of polydispersity (Mw / Mn) of 10 or less, and a vinyl bond content such as a 1,2 bond or a 3,4 bond of the conjugated diene portion. Is 5% or more, preferably 20 to 90%
It is. If it is less than 5%, the resulting molded article has a hard feel and does not meet the purpose of the present invention. Here, component (a-2)
Is 50% by weight.
Hereinafter, it is preferably from 5 to 35% by weight. 50% by weight
If the ratio exceeds the above range, the resulting molded article will have a hard feel, which does not meet the purpose of the present invention. As the aromatic vinyl compound in the component (a-2), those similar to the component (a-1) are used. The aromatic vinyl compounds are randomly linked, and can be found in Korsov [I. M. Kolthoff, J .; P
polymer Sci. , Vol1 p. 429 (19
46)], the content of the block-shaped aromatic vinyl compound is 10% by weight or less, preferably 5% by weight or less in the total bound aromatic vinyl compound. As the conjugated diene compound, those similar to the component (a-1) are used, and examples thereof include butadiene, isoprene, 2,3-dimethylbutadiene, and pentadiene. Preferably, at least 90% of the aliphatic double bonds based on the conjugated diene compound are hydrogenated.

Component (b) Softener for Non-Aromatic Rubber As component (b) of the present invention, non-aromatic mineral oil or liquid or low molecular weight synthetic softener can be used.

The non-aromatic rubber softener used as component (b) in the present invention is a paraffinic or naphthenic or a mixture thereof. The use of an aromatic softening agent is not preferred because its use makes the component (a) soluble and inhibits the cross-linking reaction, so that the physical properties of the obtained composition cannot be improved. The component (b) is preferably a paraffinic one, and more preferably a paraffinic one that does not contain an aromatic ring component.

These non-aromatic rubber softeners have a dynamic viscosity at 37.8 ° C. of 20 to 500 cS.
t, pour point is -10 to -15 ° C, flash point (COC) is 1
Indicates 70 to 300 ° C.

The amount of component (b) is 100 parts (a)
The upper limit is 240 parts by weight based on parts by weight. There is no particular lower limit. If the amount exceeds the upper limit, bleed-out of the softener tends to occur, which may give tackiness to the final product, and also deteriorates mechanical properties.

Component (c) Peroxide-crosslinked olefin
High-density polyethylene (low-pressure polyethylene), low-density polyethylene (high-pressure polyethylene), linear low-density polyethylene , and / or its copolymer peroxide-crosslinked olefin-based resin and / or its copolymer. Polyethylene such as polyethylene (a copolymer of ethylene and a small amount, preferably 1 to 10 mol% of an α-olefin such as butene-1, hexene-1, octene-1), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene One or more selected from acrylic ester copolymers and the like are preferably used. Particularly preferred are produced with a metallocene catalyst (single site catalyst), a density of 0.90 g / cm ³ or less of ethylene-octene copolymers or density 0.90 g / cm ³ or more ethylene-hexene copolymers.

There is no particular lower limit on the amount of component (c).
The upper limit is 100 parts by weight based on 100 parts by weight of component (a). If the upper limit is exceeded, the flexibility of the obtained elastomer composition is lost, and bleed-out of the rubber softener (b) tends to occur.

Component (d) peroxide decomposable olefin
As the peroxide-decomposable olefin-based resin and / or its copolymer of the olefin-based resin and / or its copolymer component (d), any of a polypropylene compound composed of a homopolymer, a block copolymer, a random copolymer, or the like is used. You can do it. For example, copolymers of propylene with other small amounts of α-olefins such as ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and the like are preferred.

The component (d) of the present invention has the effect of improving the rubber dispersion in the obtained composition and improving the appearance of the molded article. The upper limit of the amount of component (d) is component (a) 1.
100 parts by weight to 100 parts by weight. There is no particular lower limit. 1
When the amount exceeds 00 parts by weight, the flexibility and rubber elasticity of the obtained elastomer composition are deteriorated.

Component (e) Liquid polybutadiene Liquid polybutadiene has a main chain of vinyl bonds, and is composed of 1,2-bonds, trans 1,4-bonds, and cis 1,4-bonds, and is transparent at room temperature. Liquid polymer. Here, the 1,2-bond is preferably at most 30% by weight, and if the 1,2-bond exceeds 30% by weight, the low-temperature properties of the composition obtained are undesirably reduced.

The number average molecular weight of the liquid polybutadiene is:
The upper limit is preferably 5,000, more preferably 4,000.
0, and the lower limit is preferably 1,000, more preferably 3,000. If the amount is less than the lower limit, the heat-deformation resistance of the obtained composition decreases, and if it exceeds the upper limit, the compatibility of the obtained composition decreases.

Further, the liquid polybutadiene is preferably a copolymerizable compound having one or more groups selected from an epoxy group, a hydroxyl group, an isocyanate group and a carboxyl group. Among them, those having a hydroxyl group and an unsaturated double bond are particularly preferred. Commercially available products include, for example, R-45HT (trademark) manufactured by Idemitsu Petrochemical Co., Ltd.
Is mentioned.

The amount of the component (e) is 100 parts (a).
The upper limit is 30 parts by weight based on parts by weight. There is no particular lower limit, but if it exceeds the upper limit, the mechanical properties of the composition deteriorate.

Component (f) unsaturated glycidyl compound or
The derivative of the unsaturated glycidyl compound or derivative thereof is used as a modifier, preferably a glycidyl compound having an unsaturated group capable of copolymerizing with an olefin and a glycidyl group in the molecule, and particularly preferably glycidyl. Methacrylate (GMA) is used. The modifying agent preferably decomposes the soft component of the hydrogenated block copolymer in component (a), the peroxide-crosslinked olefin resin of component (c), and / or the copolymer thereof, and the peroxide decomposition of component (d). Type olefin resin, and / or
Alternatively, it is considered that the copolymer is modified.

The amount of component (f) is 100 parts (a)
The upper limit is 15 parts by weight based on parts by weight. There is no particular lower limit. If the ratio exceeds the upper limit, not only the heat deformation resistance and mechanical properties of the composition are deteriorated, but also the effect of improving the compatibility of the component (i) when blended is not recognized.

Component (g) Unsaturated carboxylic acid or derivative thereof
Conductive unsaturated carboxylic acids or derivatives thereof are those used as modifiers, preferably acrylic acid, methacrylic acid, maleic acid, dicarboxylic acids or derivatives thereof such as acids, halides, amides, imides, anhydrides, esters and the like. No. Particularly preferred is maleic anhydride (MAH)
Is used. Due to the modifier, preferably component (a)
A soft component of the hydrogenated block copolymer, a peroxide-crosslinked olefin resin of component (c), and / or
Alternatively, it is considered that the copolymer rubber containing the same and the peroxide-decomposable olefin resin of the component (d) and / or the copolymer rubber containing the same are modified.

The amount of the component (g) is 100 parts (a).
The upper limit is 15 parts by weight based on parts by weight. There is no particular lower limit, but when it exceeds the upper limit, not only does the composition cause severe yellowing, but also when the component (i) is blended, the effect of improving the compatibility of the component is not recognized.

Component (h) (meth) acryl having a hydroxyl group
The (meth) acrylic acid ester compound having a hydroxyl group of the luic acid ester compound component (h) has an effect of improving the compatibility between the components (a) and (b). Examples include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, 3-hydroxybutyl acrylate, ethyl-2-hydroxyethyl fuma Rate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate and a polymer, copolymer, or copolymer with another monomer comprising the same. Here, examples of the copolymerizable monomer include ethylene, propylene, styrene, vinyl acetate, and vinyl chloride. Preferably, 2-hydroxyethyl methacrylate is used.

The amount of component (h) is 100 parts (a).
The upper limit is 15 parts by weight with respect to parts by weight. There is no particular lower limit, but if the amount exceeds the upper limit, a large amount of gas is generated during molding.

Component (i): Ethylene-based copolymer The ethylene-based copolymer of the component (i) is composed of ethylene and the general formula

Embedded image CH ₂ ＣC (R ₁ ) —COOM (wherein R ₁ represents hydrogen or a methyl group, and M represents Na, Z
represents a metal such as n or hydrogen. ) Is a copolymer with the monomer represented by Here, examples of the monomer represented by the general formula 3 include metal methacrylate, metal acrylate, methacrylic acid, and acrylic acid. Among them, metal methacrylate is preferred. This copolymer is an ionic copolymer having an ionic cross-linking bond having a high resilience, specifically, a copolymer with ethylene and an unsaturated organic acid such as acrylic acid or methacrylic acid. It is preferable that the acid is completely or partially neutralized to form a salt as in the general formula (3). The cation of the acid is usually an alkali metal, zinc or the like. In particular, it is preferable to use a mixture of sodium and zinc since a high rebound resilience can be obtained. In the copolymer with ethylene, the above monomer is contained in an amount of 3 to 20% by weight, especially 4 to 1%.
It preferably accounts for 5% by weight. Preferred is an ethylene-metal methacrylate copolymer having a metal methacrylate content of 3 to 20% by weight, especially 4 to 15% by weight. If the amount of the above-mentioned monomer is less than 3% by weight, there is a problem that the monomer is not sufficiently dispersed in the obtained composition. If the amount exceeds 20% by weight, the required resilience cannot be obtained. In addition, the above copolymer is 0.5
Melt flow rate of up to 15 g / 10 min (JIS K
6760, and measured at a temperature of 190 ° C. and a load of 2160 g). Here, if necessary, an ethylene-vinyl acetate copolymer and an ethylene-α-olefin copolymer can be blended, and a mixture of three or more resins can be used.

The incorporation of the component (i) dramatically improves the scratch resistance and abrasion resistance of the obtained elastomer composition. Further, if the elastomer containing the ethylene copolymer is used as a cover material and an intermediate layer for a golf ball composed of a urethane polymer and / or a copolymer thereof, an ionomer resin, and a polybutadiene core material, they are pulverized at once. Can be recycled.

The amount of component (i) is 100 parts (a)
The lower limit is at least 1 part by weight and the upper limit is 15 parts by weight.
Not more than 00 parts by weight. If it exceeds 1500 parts by weight, the flexibility of the obtained elastomer composition is reduced, and there is no great difference from the ethylene copolymer alone.

Component (j) Organic peroxide In the dynamic crosslinking of the present invention, an organic peroxide is used. Examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, 2,5-dimethyl-2, 5
-Di (tert-butylperoxy) hexyne-3
1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane,
n-butyl-4,4-bis (tert-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperoxy Examples thereof include isopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide.

Of these, 2,5-dimethyl-2,5-di- (te) is preferable in terms of odor, coloring and scorch stability.
Most preferred are rt-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexyne-3,1,3-bis (tert-butylperoxyisopropyl) benzene.

There is no particular lower limit for the amount of peroxide to be added to 100 parts by weight of the composition comprising components (a) to (h) at the time of peroxide addition. The upper limit is 3.
5 parts by weight. If the amount exceeds 3.5 parts by weight, the crosslinking proceeds excessively, and the dispersion of the crosslinked product becomes poor.

Crosslinking Aid In the present invention, it is preferable to use a crosslinking aid in performing dynamic crosslinking. Examples of the crosslinking assistant include polyvinyl monomers such as divinylbenzene and triallyl cyanurate, or ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl. Examples include polyfunctional methacrylate monomers such as methacrylate. By using such a compound, a uniform and efficient crosslinking reaction can be expected. Among them, triethylene glycol dimethacrylate is effective because it is easy to handle and works as a dispersing aid.

The amount of the crosslinking aid used is preferably about 2 to 2.5 times the amount of the peroxide. Although there is no particular lower limit, composition 1 comprising components (a) to (h)
The upper limit is 10 parts by weight based on 00 parts by weight. 10 added
Exceeding the weight parts lowers the crosslinking efficiency.

The composition of the present invention may contain, in addition to the above essential components, a polyester polymer and / or a copolymer thereof, a polyamide polymer and / or a copolymer thereof, and polymethylpentene, depending on the intended use. Polymers and / or copolymers thereof, various anti-blocking agents, sealant improvers, heat stabilizers, antioxidants, ultraviolet absorbers, lubricants, crystal nucleating agents, coloring agents, inorganic fillers, foaming agents (organic System, inorganic system) and the like. Optionally used antioxidants include 2,6-di-tert-p-butyl-p-
Cresol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol, 4,4-dihydroxydiphenyl, tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane and the like Phenolic antioxidants, phosphite antioxidants and thioether antioxidants. Among them, phenolic antioxidants and phosphite antioxidants are preferred.

The thermoplastic resin composition for a golf ball of the present invention can be produced, for example, by the following steps. The components (a) to (j) and the optional components may be kneaded all at once, but more preferably by the following method. First, components other than the component (i) are kneaded under heating. When the component (j) organic peroxide is used and crosslinking is performed simultaneously with the introduction of a functional group, a crosslinking aid is preferably added. As the kneading method, a method usually used for rubber, plastics and the like can be used satisfactorily. For example, a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, various kneaders and the like are used. By this step, the components are uniformly dispersed and the functional groups are efficiently introduced, so that a composition having good compatibility can be obtained.

When adding the component (i), the component (i) is then added to the composition obtained in the above step and kneaded. The kneading can be generally performed using a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, various kneaders, or the like. In this step, the reaction is completed at the same time as the dispersion of each component further proceeds. Conveniently, component (i) is side-fed and continuously performed with the above steps. It is also possible to dry blend the composition obtained in the above step with component (i) and to perform injection molding.

As a kneading method, it is preferable to use a twin screw extruder or a Banbury mixer having an L / D of 47 or more, since all the steps can be continuously performed. In addition, for example, when kneading with a twin-screw extruder, if the number of rotations of the screw is 80 to 350 rpm, each component has good dispersion and good properties can be obtained.

[0044]

The present invention will be described in detail below with reference to examples and comparative examples. The amounts in the table mean parts by weight unless otherwise specified.

The following components were used as the components in the examples. Component (a-1-1): hydrogenated block copolymer Septon 2002 manufactured by Kuraray Co., Ltd. Styrene content: 30% by weight Isoprene content: 70% by weight Number average molecular weight (Mn): 55,000 Weight average molecular weight ( Mw): 60,000 Mw / Mn: 1.09 Hydrogenation rate: 90% or more Component (a-1-2): Hydrogenated block copolymer Septon 4077 manufactured by Kuraray Styrene content: 30% by weight of isoprene Content: 70% by weight Number average molecular weight (Mn): 260,000 Weight average molecular weight (Mw): 320,000 Molecular weight distribution: 1.23 Hydrogenation rate: 90% or more Component (a-2): hydrogenated random Polymer (hydrogenated SB
R) Dinalon 1320P (trademark) manufactured by JSR Styrene content: 10% by weight Number average molecular weight (Mn): 300,000 Mw / Mn: 1.1 Hydrogenation rate: 90% or more

Component (b): Non-aromatic rubber softener Diana Process Oil PW-90 manufactured by Idemitsu Kosan Co., Ltd. Type: paraffinic oil Weight average molecular weight: 540 Content of aromatic component: 0.1% or less Component (d) ): Peroxide-decomposable olefin resin polypropylene, BC03C (trademark), manufactured by Mitsubishi Chemical Corporation Component (e): liquid polybutadiene R-45HT (trademark), manufactured by Idemitsu Petrochemical Co., Ltd. Hydroxyl group as a functional group (acrylic first class) And a copolymerizable unsaturated double bond (1,4 bonds: 80%). Number average molecular weight: 2800 component (f): glycidyl methacrylate manufactured by Kanto Chemical Co., Ltd.

Component (g): maleic anhydride manufactured by Kanto Chemical Co., Ltd.

Component (h): (meth) acrylate compound having a hydroxyl group 2-hydroxyethyl methacrylate, light ester HO (trademark), manufactured by Kyoeisha Chemical Co., Ltd. Component (i): ethylene / acrylic acid copolymer Himilan 1605 (trademark) manufactured by Du Pont-Mitsui Density: 0.95 g / cm ³ , melting point 90 ° C, melt index (measuring temperature 190 ° C, measuring load 2.16 kg) Ion crosslinked product, metal salt: sodium

Component (j): Organic peroxide Perhexa 25B (2,5-dimethyl- manufactured by NOF Corporation)
2,5-di (t-butyl peroxide) hexane) Crosslinking aid: NK ester IND (2-methyl- manufactured by Shin-Nakamura Chemical Co., Ltd.)
1,8-octanediol dimethacrylate (85
%), 1,9-nonanediol dimethacrylate (15%
%) Mixture)

The resin composition thus obtained was evaluated by the following method. Evaluation method 1) Rebound resilience According to BS903, a test piece used a 4 mm-thick press sheet. Good rebound resilience of 60% or more 2) Taber abrasion JIS K 7204 A 2 mm thick press sheet was used as the test piece, and the wear wheel H-2 was used.
The wear mass after 2,1000 rotations was measured. Taber abrasion of 200 or less is good. 3) Hardness According to JIS K 7215. A 6.3 mm thick pressed sheet was used as a test piece. 4) Adhesion test

[0051] Length 150mm, width 25mm, thickness 4mm
Was prepared by injection molding. The resins used to make the resin plate are as follows. Polyurethane-based polymer (product name T-78 manufactured by DIC Bayer Polymer Co., Ltd.)
90) Ionomer resin (product name: Himilan H-, manufactured by DuPont-Mitsui Polychemicals)
1605) Injection conditions: Injection molding machine: FS-120 manufactured by Nissei Plastics Co., Ltd. Molding temperature: 200 ° C. or 250 ° C. Injection speed: 55 mm / sec Injection pressure: 1400 kg / cm ² Holding pressure: 400 kg / cm ² Injection time: 6 Seconds Cooling time: 45 seconds

The resin plate prepared in this manner is inserted into a mold (at this time, as shown in FIG. 2, paper is pasted on a part of the resin plate with a double-sided tape). The composition of the present invention obtained as described above was injection molded to prepare test pieces as shown in FIGS.

Subsequently, the 180 ° peel strength of the obtained test piece was measured. The measurement was performed by bending the composition of the present invention as shown in FIG. 3 and pulling both ends of the resin plate and the composition in the directions of the arrows.

[0054]

[Table 1]

[0055]

[Table 2]

FIG. 1

FIG. 2

(Examples 1 and 2) Resin compositions were prepared according to the above-mentioned steps using the respective components in the amounts shown in Table 1. Table 1 shows the results
Shown in The resin composition of the present invention is excellent in rebound resilience, abrasion resistance, and adhesion to a polyurethane polymer or an ionomer resin.

(Comparative Example 1) Only the component (i) is inferior to Examples 1 and 2 of the present invention in adhesion to a polyurethane polymer.

(Reference Example 1) The amount of component (i) according to the present invention is desirably 100 parts by weight or more based on 100 parts by weight of component (a).

Example 3 A resin composition was prepared according to the above-mentioned steps using the respective components in the amounts shown in Table 2. Table 2 shows the results. The resin composition of the present invention is excellent in rebound resilience, abrasion resistance, and adhesion to a polyurethane polymer or an ionomer resin. In particular, the addition of the components (f) and (g) significantly improves the abrasion resistance due to the improved compatibility.

Comparative Example 2 The results are shown in Table 2. Comparative Example 2
In Example 3, since components (f) and (g) were not added to Example 3, the surface layer peeling was remarkable due to deterioration in compatibility.

[0063]

As described above, the present invention provides a resin composition of another layer of a conventional multi-piece golf ball cover material while maintaining the basic properties of a golf ball such as excellent moldability, abrasion resistance and rebound resilience. In particular, a thermoplastic resin composition for a golf ball can be obtained in which the adhesive strength to a polyurethane resin or an ionomer resin and the peeling property are remarkably improved, and the degree of freedom of the hardness is high.

[Brief description of the drawings]

FIG. 1 is a plan view of a test piece comprising a composition of the present invention and a resin plate.

FIG. 2 is a cross-sectional view of a test piece comprising the composition of the present invention and a resin plate.

FIG. 3 is a diagram for explaining a method for measuring a 180-degree peel strength.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 test piece 2 composition of the present invention 3 resin plate 4 paper A heat-sealed portion

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 9/00 C08L 9/00 9/06 9/06 15/00 15/00 23/00 23/00 23 / 08 23/08 53/02 53/02 91/00 91/00 F term (reference) 4J002 AC035 AC08X AC11X AE053 BB034 BB054 BB064 BB074 BB08W BB145 BB154 BB155 BP01X EK036 EK046 EK056 EK086 FD070 PF146 PA30J01 4J026 AA12 AA13 AA14 AC01 AC10 AC11 AC16 AC18 AC19 AC23 AC32 BA25 BA27 BA30 BA33 BA34 BA35 DB13 GA07

Claims (4)

[Claims] (1) 100 parts by weight of at least one copolymer selected from (a) an aromatic vinyl compound-conjugated diene compound copolymer and / or a hydrogenated product thereof, and (b) a non-aromatic rubber. 0 to 240 parts by weight of a softening agent for use, (c) 0 to 100 parts by weight of a peroxide-crosslinked olefin-based resin and / or a copolymer thereof, and (d) 0 to 100 parts by weight of a peroxide-decomposable olefin-based resin and / or a copolymer thereof. To 100 parts by weight, (e) 0 to 30 parts by weight of liquid polybutadiene, (f)
0 to 15 parts by weight of an unsaturated glycidyl compound or a derivative thereof, (g) 0 to 15 parts by weight of an unsaturated carboxylic acid or a derivative thereof, (h) 0 to 15 parts by weight of a (meth) acrylate compound having a hydroxyl group, and (J) Organic peroxide: 0 to 100 parts by weight in total of (a) to (h)
3.5 parts by weight, (i) ethylene and the general formula CH ₂ ＣC (R ₁ ) -COOM (wherein R ₁ represents hydrogen or a methyl group, M is Na, Z
a thermoplastic resin composition for a golf ball, comprising 1 to 1500 parts by weight of at least one copolymer selected from the group consisting of ethylene copolymers represented by the following formulas: . (2) The component (a) contains (a-1) an aromatic vinyl compound content of 50% by weight or less and a number average molecular weight (M
n) is a block copolymer having a molecular weight of 5,000 to 1,500,000 and a polydispersity (Mw / Mn) of 10 or less;
Or a hydrogenated product thereof, and (a-2) the content of the (a) aromatic vinyl compound is 50% by weight or less, the number average molecular weight (Mn) is 5,000 to 1,000,000,
The thermoplastic resin for a golf ball according to claim 1, wherein the thermoplastic resin is at least one selected from the group consisting of a random copolymer having a polydispersity (Mw / Mn) of 10 or less, or a hydrogenated product thereof. Resin composition. 3. Component (a-1) is a hydrogenated styrene-isoprene-butadiene-styrene block copolymer, and / or
The thermoplastic resin composition for a golf ball according to claim 2, wherein the thermoplastic resin composition is a hydrogenated styrene-isoprene-styrene block copolymer, wherein at least 70% of the olefinically unsaturated bonds are hydrogenated. 4. The composition according to claim 2, wherein component (a-2) is a hydrogenated styrene-butadiene random copolymer, wherein at least 70% of its olefinically unsaturated bonds are hydrogenated. Thermoplastic resin composition for golf balls.