JPS61258844A - Rubber composition - Google Patents

Abstract

PURPOSE:A rubber composition, obtained by incorporating a silicone rubber component consisting of a silicone rubber and polybutadiene rubber with the first and second components of a hardness regulator, weight regulator and hardener, having high impact resilience and suitable for core materials of gold balls. CONSTITUTION:A rubber composition obtained by incorporating (A) 100wt% rubber component consisting of 4-10wt%, preferably 5-40wt% silicone rubber having >=800 polymerization degree of the siloxane units and 96-0wt%, preferably 95-60wt% polybutadiene rubber having >=40% cis-1,4-bonds in the total polymer units with (B) 1-200wt% short fibrous high-strength and high-modulus fibers having >=10mum length, e.g. carbon fibers or alumina fibers, as the first component of a hardness regulator and an unsaturated carboxylic acid (metal salt) as the second component thereof, etc., (C) zinc acid (metal salt) as the second component thereof, etc., (C) zinc oxide, barium sulfate, etc., as a weight regulator and (D) 0.2-10wt% hardener, preferably organic peroxide compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rubber composition, and particularly to a high repulsion elasticity rubber composition that can be suitably used for manufacturing golf poles.

[Prior Art] In general, golf poles are structurally divided into one-piece golf poles made of a single constituent material, two-piece golf poles made of a core material covered with a cover material, and
A thread-wound golf pole is created by wrapping a thin intelligence band around a central core material and then covering it with a cover material.

Therefore, in order to manufacture a golf pole having any of these structures, it is necessary that the central core material has high repulsion. Conventionally, as the rubber material for the central core of a golf pole, a rubber composition with high repulsion elasticity made of polybutadiene rubber has been used.

In contrast, the present inventors have previously found that by blending silicone rubber with polybutadiene rubber, the rebound elasticity of the rubber obtained is improved, and when used as a golf pole material, the distance of the pole increases. I found it.

[Problems to be Solved by the Invention] However, the desired performance for a rubber material for a golf pole includes high rebound resiliency and high hardness. That is, if the hardness of the rubber material of the golf pole is low, the amount of deformation will be large during high-speed hitting, and the characteristics of the material rubber composition will not be reflected sufficiently, making it impossible to obtain a good flight distance.

Therefore, there has been a strong desire for a rubber composition suitable for manufacturing golf poles, which has improved both impact resilience and hardness.

[Means for Solving the Problems] The present invention has high repulsion elasticity and is suitable for manufacturing golf poles.
4 to 100% by weight of silicone rubber having a degree of polymerization of siloxane units of 800 or more, which provides a rubber composition capable of obtaining a rubber material having sufficient hardness.
and cis-1,4-bonds in all polymer units are 40%
To the rubber component consisting of 96 to 0% by weight of polybutadiene rubber, as the first component of the hardness modifier, 1% by weight of short, high-strength, high-elasticity fibers with a length of 10 microns or more are added.
The gist of the present invention is to provide a comb composition comprising the above compositions and further containing a second component of a hardness modifier, a weight modifier, and a curing agent.

That is, the present inventors have conducted intensive studies to find a rubber composition with high repulsion that guarantees a long flight distance when used in golf poles. Rubber 4~too weight%
and cis-1,4-bonds in all polymer units are 40%
To the rubber component consisting of 96 to 0% by weight of polybutadiene rubber, as the first component of the hardness modifier, 1% by weight of short fiber-like high-strength, high-elasticity m-fibers with a length of 10 microns or more are added.
When a crosslinked rubber obtained by crosslinking a rubber composition formed by blending the above ingredients and further blending a second component of a hardness modifier, a weight modifier, and a curing agent, the crosslinked rubber obtained is used as a core material of a golf pole. Golf poles always have high repulsion,
The first component of the hardness modifier, i.e., short fibers with a length of 10 microns or more However, the present invention has been completed.

The present invention will be explained in more detail below.

The rubber component of the rubber composition of the present invention includes 4 to 100% by weight of silicone rubber having a degree of polymerization of siloxane units of 800 or more and cis-1,4-bonds in the total polymer unit being 4 to 100% by weight.
It consists of 96-0% by weight of polybutadiene rubber, which is 0% or more.

In the rubber component, silicone rubber has a polymerization degree of siloxane units of 800 or more. Silicone rubber with a polymerization degree of less than 800 has sufficient compatibility with rubber other than silicone rubber in the rubber component, such as polybutadiene rubber. It is desirable that the degree of polymerization of the siloxane unit is 6,000 or more, particularly 9,500 or more, which is undesirable because it cannot be obtained.

A silicone rubber made of such a polymer of siloxane units is represented by the general formula (wherein R and R' are side chains and are the same functional group (800 or more in the present invention)).

In the above formula, 0.1% or more of the total amount of side chains R, R'
% or less, preferably from 1% to 40%, more preferably from 5% to 30%, is a vinyl group. When the vinyl group content is less than 0.1% based on the total amount of side chains, a sufficient network structure cannot be formed, and as a result, the resulting rubber composition does not exhibit sufficient impact resilience.

Moreover, it is preferable that most of the functional groups other than vinyl groups in the side chains are methyl groups. In addition, a phenyl group or trifluoroethyl group may be present as long as it does not exceed 5% of the total amount of side chains. If the phenyl group or trifluoroethyl group is present in an amount of 5% or more based on the total amount of side chains, the glass transition temperature of the silicone rubber will be significantly increased, and as a result, the resulting rubber composition will exhibit sufficient impact resilience. It may disappear.

Note that the silicone rubber used in the present invention is preferably of a heat-crosslinking type.

The content of such silicone rubber in the rubber component is 4~
It is preferably 100% by weight, particularly 5 to 40% by weight.

Polybutadiene rubber used with silicone rubber has more than 40% cis-1,
4-bond structure, preferably 85% or more,
More preferably, it is a structure in which cis-1,4-bonds account for 90% or more, particularly preferably 93% or more, but when using a structure in which cis-1°4-bonds account for less than 40%, The resulting rubber composition no longer exhibits sufficient impact resilience.

Further, the polybutadiene rubber used in the present invention preferably has a Mooney viscosity (ML1+4) of 30 or more, more preferably 44 or more.

Particularly preferably, it is 60 or more.

The content of such polybutadiene rubber in the rubber component is 96 to 0% by weight, particularly preferably 95 to 60% by weight.

In addition, in the rubber composition of the present invention, other rubber components such as polyisoprene rubber, natural rubber, styrene rubber, etc. may be added in an amount not exceeding 10 parts by weight per 100 parts by weight of the rubber component consisting of silicone rubber and polybutadiene rubber. Butadiene rubber, NBR, acrylic rubber, chloroprene rubber, chlorosulfonated polyethylene, butyl rubber, EFT, thermoplastic elastomer rubber, etc. may be added.

Short fiber-like high strength and high elasticity m! which is the first component of the hardness modifier added to such rubber components! As a, high-strength/high-elasticity fibers such as carbon fibers, alumina fibers, aromatic polyamide fibers, silicon carbide fibers, silica fibers, poron fibers, and potassium titanate fibers are preferably used, and carbon fibers are particularly preferred. Others include polyamide fiber, polyester fiber, polyvinyl alcohol fiber, polyacrylic fiber,
Pylyvinyl chloride fiber, polyvinylidene chloride fiber, polyethylene fiber, polypropylene fiber, polyurea r
General synthetic fibers such as am or natural fibers can also be used.

What is the length of the fiber that is the first component of the hardness modifier?

It is 10 pm or more, preferably 30 mm or less.

In addition, this taM is the ratio (L) of the length L) and the diameter (D).
/D) is preferably 5 or more, particularly short Fa males with a length of 50 microns or more and L/D = 50 or more,
In particular, L/D=1 for short m fibers with a length of 100 microns or more
00 or more is preferable. When the fiber length of the short fibers is short and approaches L/D=1, energy loss may occur due to interaction with the rubber component, and the resulting rubber composition may not exhibit sufficient impact resilience.

The first component of such a hardness modifier is 1 to 200 parts by weight, preferably 5 to 200 parts by weight, particularly preferably 10 to 100 parts by weight, based on 100 parts by weight of the rubber component consisting of silicone rubber and polybutadiene rubber. It is preferable to mix parts by weight. The amount of the first component of the hardness modifier is rubber component 1
If the amount is less than 1 part by weight per 00 parts by weight, it may not be effective as a hardness modifier.

As the first component of the hardness modifier, only one type of short fibers as described above may be used, or two or more types of short fibers of different types, m fiber lengths, and fiber diameters may be used in combination.

As the second component of the hardness modifier, the following (a) to (h) can be used.

(a) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, sorbic acid, tiglic acid, cinnamic acid, and aconitic acid.

(b) Unsaturated carboxylic acid of (a), Ca, Mg
, an unsaturated carboxylic acid metal salt with a metal ion having a valence of 1 to 3, such as Ba or Na.

(C) Formic acid, acetic acid, pencil acid, glycolic acid, D
L-mandelic acid, thioglycolic acid, tartaric acid, citric acid, DL-malic acid, carbamic acid, adipic acid, alginic acid, azelaic acid, n-butyric acid, n-caproic acid, n-
Saturated carboxylic acids such as capric acid and n-caprylic acid.

(d) Aromatic carboxylic acids such as benzoic acid, salicylic acid, trimellitic acid, phthalic acid, tannic acid, and tetrachlorophthalic acid.

(e) N-acetylglycine, β-alanine, DL
- Amino acids such as aspartic acid, L-glutamine, glycine, L-geltamic acid, DL-methionine, DL-phenylalanine, N-phenylglycine, L-tyrosine.

(f) Unsaturated compounds such as allyl alcohol, allyl Φ diallyl phthalate, allyl acetate, diallylamine, benzalacetone, and diallyl maleate.

(g) Above (a), (c), (d), (e), (f
) Derivatives such as esters, lactones, halides, anhydrides, amides, imides, lactams, hydrazides, and azides of the compounds described in .

(h) the compound described in (C) to (f) above and Zn,
A regulator containing a metal ion having a valence of 1 to 3, such as Na, Ca, Mg, and Ba.

Among these, those described in (a) and (b) are particularly preferred. In addition, as the second component of the hardness modifier, the above-mentioned (
One type of a) to (h) may be used alone, or two or more types may be used in combination.

In addition, the second component of the hardness modifier includes carbon black, silica, calcium carbonate, magnesium silicate,
Reinforcing fillers such as aluminum silicate, phenolic resin, coumaron resin, urea resin, unsaturated polyester, melamine resin, alkyd resin, epoxy resin, polyethylene, vinyl chloride resin, polypropylene, polystyrene.

Organic fillers such as ABS resin, AS resin, polyvinyl alcohol, methacrylic resin, petroleum resin, polyamide, vinyl chloride resin, polycarbonate, fluororesin, etc.
species or two or more species, or these and the above (a) to (h)
It can also be used in combination with the compound.

The amount of the second component of the hardness modifier is determined depending on the hardness required of the obtained rubber composition and the type of the second component to be blended.For example, acrylic acid, methacrylic acid, etc. in (a) When using an unsaturated carboxylic acid, the amount of the second component of the hardness modifier is preferably 30 parts by weight or less based on 100 parts by weight of the rubber component consisting of silicone rubber and polybutadiene rubber, and 25 parts by weight or less. Particularly preferably, the amount is not more than parts by weight.

Weight adjusters include zinc oxide, barium sulfate, alumina, calcium sulfate, aluminum sulfate, molybdenum disulfide, calcium carbonate, aluminum silicate, magnesium silicate, graphite, metal powder, silica sand, pumice powder, slate powder, and mica. Powder, asbestos, glass bulbs, etc. having a specific gravity of 1.5 or more are preferably used. These weight adjusters can be used alone or in combination of two or more.

The weight adjuster is blended by appropriately adjusting the amount so that the obtained rubber composition has the required specific gravity.For example, when the rubber composition of the present invention is used for a golf pole, the weight of the golf pole In order to meet the specifications, it is preferable to blend the rubber in an amount such that the weight of the rubber button is 1.0 to 1.5.

Hardeners include tert-butyl hydroperoxide, cumene hydroperoxide, di-tert-butyl peroxide, tert-butyl cumyl peroxide, 2,5-dimethyl-2,5-(tert-butyl peroxy)hexane. , 2,5-dimethyl-2,5-di(tert-butyl peroxy)hexyne-3, dicumyl peroxide, benzoyl peroxide, tert-butyl Φ peroxy isopropyl carbonate, 1,1-bis(tert-butyl fist peroxy) 3.゛3,5-trimethyl cyclohexane, 2,4-dichloro benzoyl peroxide, 1,
3-bis(tert-butyl peroxy isopropyl)benzene, tert-butyl peroxy benzoate, p-
Chloro-benzoyl peroxide, n-butyl-4,
Organic peroxides such as 4-bis(tert-butyl peroxy)valerate, tert-butyl, <rubenzoate, sulfur, resin vulcanizing agents (quinone dioxime, phenols-aldehydes, condensates, and derivatives thereof) 1 species or two
More than one species is used. Among these, organic peroxide compounds are suitable as curing agents.

The blending amount of these curing agents is not particularly limited, but rubber component 10 consisting of silicone rubber and polybutylene rubber
0.2 to 10% by weight, preferably 0.0% by weight.
4 to 4% by weight, more preferably 0.6 to 1.6% by weight
It is desirable to do so.

In the present invention, in addition to the first and second components of the hardness modifier, the weight modifier, and the curing agent, other components such as an antiaging agent may be added as necessary. Examples include naphthylamine type, diphenylamine type, P-
Phenylenediamine, quinoline, monophenol, bisphenol, trisphenol, polyphenol, thiobisphenol, hydroquinone derivatives,
Conventional anti-aging agents for rubber compositions such as waxes are used.

The rubber composition of the present invention has a temperature of 20 to 30
Easily crosslinked by heating for minutes.

When obtaining a crosslinked rubber composition by crosslinking the rubber composition of the present invention consisting of the rubber component, the first component of the hardness modifier, the second component of the hardness modifier, the weight modifier, and the curing agent, depending on the purpose of use. For example, when a crosslinked rubber composition is used as a core material for a golf pole, the JISA hardness of the crosslinked rubber composition is 80. -97, especially preferably 85-95, and the specific gravity is preferably in the range of 1.0-1.5, JIS
If the A hardness is less than 80, the core material of the golf pole using the above-mentioned crosslinked rubber composition may be deformed when a thin elastic band is wrapped around it or when a cover material is applied. Further, if the JISA hardness exceeds 97, the feeling of hitting the golf pole may be impaired.

Therefore, the amount of ingredients, crosslinking conditions, etc. should be determined according to the preferred JISA
The hardness and specific gravity are selected to achieve the desired hardness and specific gravity.

When the rubber composition of the present invention is applied to golf poles, it is effective as a core material for two-piece poles, one-piece pole materials, and thread-wound golf poles. In addition,
When manufacturing a two-piece pole or the like, the cover material covering the core is preferably an ionomer resin made of a metal salt of a copolymer of ethylene and an unsaturated carboxylic acid. Examples of the unsaturated carboxylic acid of this ionomer resin include acrylic acid and methacrylic acid, and examples of the metal forming the metal salt include Na, Mg, and Zn.

The rubber composition of the present invention, especially the rubber composition obtained by crosslinking the same, has excellent rebound properties and suitable hardness, and therefore, as mentioned above, it can be suitably used as a material for golf poles, especially as a core material, and can be used for golf poles. Although the flying distance of a pole can be increased, the rubber composition of the present invention can be used not only for golf poles but also for high-repulsion materials such as tennis and baseball poles, toys, sidewalls of fuel-efficient tires, shoes, and rubber springs. It can also be effectively used for members that require elasticity or low energy loss.

[Function] 4 to 100% by weight of silicone rubber with a degree of polymerization of siloxane units of 800 or more and cis-
Polybutadiene rubber 9 having 1,4-bonds of 40% or more
6 to 021i mass%, 1% by weight or more of short fibers with high strength and high elasticity having a length of 10 microns or more are blended as the first component of the hardness modifier, and the first component of the hardness modifier is By blending the two components, a weight adjuster and a curing agent, a rubber composition having extremely excellent impact resilience and appropriate hardness can be obtained.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Examples 1 to 4, Comparative Examples 1 to 3 Golf poles were manufactured using rubber compositions having the formulations shown in Table 1, and their performance was investigated.

First, each raw material shown in Table 1 was kneaded with a roll having a surface temperature of 40° C. or less to produce a sheet. Fill this sheet into a mold of an appropriate size, heat it at a temperature of 150°C and for a heating time of 20 to 30 minutes.
After heating and curing for 0 minutes, the mold was demolded. Then thickness 2
．． A two-piece golf pole was manufactured by integrally covering with a 2 mm ionomer resin cover.

The hardness and specific gravity of the obtained two-piece golf pole were measured, and the initial velocity and specific gravity were measured using a golf pole impact tester.
The flight distance was measured. The results are shown in Table 2.

Table 2 shows that the golf pole using the rubber composition of the present invention has extremely excellent initial velocity and flight distance. [Effects] As detailed above, the rubber composition of the present invention has extremely high repulsion i. In addition to having good properties, it is possible to adjust the hardness appropriately, so when used as a rubber material for golf poles, the initial speed and flying distance of the poles are significantly improved.

Therefore, the rubber composition of the present invention can be used not only for golf poles but also for tennis, baseball, etc. poles, toys, sidewalls of fuel-efficient tires, shoes, rubber springs, etc. with high repulsion elasticity or low energy loss. It is also suitable for required members.

Claims (1)

[Claims] (1) Rubber consisting of 4 to 100% by weight of silicone rubber with a degree of polymerization of siloxane units of 800 or more and 96 to 0% by weight of polybutadiene rubber in which cis-1,4-bonds in all polymer units are 40% or more. The ingredients include 1% by weight or more of short fibrous high strength/high elasticity fibers with a length of 10 microns or more as the first component of the hardness modifier, and the second component of the hardness modifier, a weight modifier and a curing agent. A rubber composition comprising: