JP2002102389A - Golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf ball which has brilliance without impairing moldability and has appearance changed in color tones by visual points. SOLUTION: The covers of the golf ball consisting of a core and >=1 layers of covers to cover the core are formed of a composition for the covers containing 0.1 to 20 pts.wt. liquid crystal polymer per 100 pts.wt. base material resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf ball having a brilliant property without deteriorating formability and having an appearance in which the color tone changes depending on the viewpoint.

[0002]

2. Description of the Related Art Conventionally, the most popular color of golf balls is white, and a resin composition containing a white pigment such as titanium oxide and a fluorescent whitening agent has been used for the cover. Also, besides white golf balls, red,
A so-called color ball is commercially available, which covers a resin composition colored with an inorganic or organic pigment such as blue, orange, pink, or green, and is coated with a color paint. However, the conventional color golf ball is merely colored in the above-mentioned color and lacks fashionability. Therefore, in order to improve the fashionability of the appearance of the golf ball, a golf ball having a pearl color has been proposed (JP-A-11-151322, etc.).

Japanese Patent Application Laid-Open No. 11-151322 discloses a golf ball comprising a core and a cover, wherein a specific amount of mica pigment, titanium oxide and fluorescent pigment is used for the cover so that the pearl can be formed without impairing the moldability. A golf ball having a color tone is disclosed. In the above golf ball,
By using mica as a pigment having a transparent thin plate crystal having a large refractive index for the cover, light interference due to partial reflection from both surfaces of such a thin plate crystal gives a pearl-like color tone to the golf ball surface Is what you do.

However, in the golf ball disclosed in the above publication, although the pearl color is provided, it is necessary to reduce the amount of the mica pigment to a small amount in order to make the weld line inconspicuous. That is, when using a mica pigment in a sufficient amount to impart a clear pearl color,
When the cover resin is injection-molded, there is a problem that a weld line can be clearly confirmed visually. Therefore, a golf ball having a pearl color tone has not been commercially available at present.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and provides a golf ball having a brilliant appearance and a color tone that changes depending on the viewpoint without impairing the moldability. The purpose is to do.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a golf ball comprising a core and at least one cover covering the core has a composition for a cover. By using a specific amount of a liquid crystal polymer, it has been found that a golf ball having a brilliancy and having an appearance in which the color tone changes depending on the viewpoint can be provided without impairing the moldability, and to complete the present invention. Reached.

That is, the present invention provides a golf ball comprising a core and one or more layers covering the core.
The present invention relates to a golf ball, wherein the cover is formed from a cover composition containing 0.1 to 20 parts by weight of a liquid crystal polymer based on 100 parts by weight of a base resin.

Further, in order to preferably carry out the present invention, the above-mentioned cover composition is added to 100 parts by weight of the base resin.
Furthermore, titanium oxide and / or barium sulfate 0.05 to
Containing 5 parts by weight, the liquid crystal polymer has a cholesteric phase structure in which a nematic phase is spirally laminated, and the particles of the liquid crystal polymer have an average particle size of 5 to 80 μm and a thickness of 0.5 to 15 μm. It is preferably a plate-like particle having the same.

In the present invention, in order to improve the fashionability of the golf ball, it is intended to give the golf ball an appearance that has a pearl color tone, that is, has a brilliant property, and that changes the color tone depending on the viewpoint.

Hereinafter, the present invention will be described in more detail. The golf ball of the present invention can be obtained by coating a cover on a core. The core includes a solid golf ball core (solid core) and a thread-wound golf ball core. (Thread-wound core) may be used.

The solid core may have a single-layer structure or a multilayer structure having two or more layers.
For example, as a core for a two-piece golf ball, 100 parts by weight of polybutadiene, an acrylic acid, an α, β-unsaturated carboxylic acid such as methacrylic acid or a metal salt thereof, or a functional monomer such as trimethylolpropane trimethacrylate is used. Vulcanizing agent (crosslinking agent) alone or in total
10-60 parts by weight, fillers such as zinc oxide, barium sulfate, etc.
30 parts by weight, peroxide such as dicumyl peroxide 0.5 to
It may be obtained by press vulcanization (crosslinking) of a rubber composition containing 5 parts by weight, if necessary 0.1 to 1 part by weight of an antioxidant. The press vulcanization is performed by, for example, heating and compressing at 140 to 170 ° C. for 10 to 40 minutes to form a spherical vulcanized product.

The thread wound core comprises a center and a thread rubber layer formed by winding thread rubber around the center in a stretched state. As the center, either a liquid system or a rubber system may be used.

The thread rubber wound around the center may be the same as that conventionally used for a wound layer of a wound golf ball. The rubber thread is stretched about 10 times over the center to form a wound core.

Next, the core is covered with at least one cover. In the golf ball of the present invention, the cover desirably has a thickness of 0.7 to 4.0 mm, preferably 1.0 to 3.8 mm, and more preferably 1.2 to 3.5 mm. If it is smaller, sufficient controllability cannot be obtained, and if it is larger than 4.0 mm, a sufficient flight distance cannot be obtained. The cover of the golf ball of the present invention may have a single-layer structure or a multilayer structure of two or more layers.
In the case of having a multilayer structure of two or more layers, the total thickness of the cover may be within the above range.

The cover of the present invention contains, as a base resin, a thermoplastic resin, particularly an ionomer resin usually used for a cover of a golf ball. Examples of the ionomer resin include those obtained by neutralizing at least a part of the carboxyl groups in a copolymer of ethylene and α, β-unsaturated carboxylic acid with metal ions, or ethylene and α, β-unsaturated carboxylic acid. It is obtained by neutralizing at least a part of carboxyl groups in a terpolymer with an α, β-unsaturated carboxylic acid ester with a metal ion. Examples of the α, β-unsaturated carboxylic acid include acrylic acid, methacrylic acid, fumaric acid, maleic acid, crotonic acid and the like, and acrylic acid and methacrylic acid are particularly preferable. Examples of α, β-unsaturated carboxylic acid ester metal salts include, for example, methyl such as acrylic acid, methacrylic acid, fumaric acid, and maleic acid.
Ethyl, propyl, n-butyl, isobutyl esters and the like are used, and acrylates and methacrylates are particularly preferred. Carboxyl groups in the above-mentioned copolymers of ethylene and α, β-unsaturated carboxylic acid or in terpolymers of ethylene, α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid ester Examples of metal ions that neutralize at least a part of sodium, potassium, lithium, magnesium, calcium, zinc, barium, aluminum, tin, zirconium, cadmium ions, etc., and particularly sodium, zinc, and magnesium ions are repelled. Often used and preferred from the viewpoints of properties, durability and the like.

Specific examples of the ionomer resin include:
Without limitation, Hi-mil
an) 1555, High Milan 1557, High Milan 16
05, High Milan 1652, High Milan 1702, High Milan 1705, High Milan 1706, High Milan 17
07, Himilan 1855, Himilan 1856 (manufactured by Mitsui DuPont Polychemicals), Surlyn
8945, Surlyn 9945, Surlyn 6320 (manufactured by DuPont), Iotek 7010, 80
00 (manufactured by Exxon) and the like. As these ionomers, the above-mentioned examples may be used alone or as a mixture of two or more.

Further, as an example of a preferable material of the cover of the present invention, the above-mentioned ionomer resin alone may be used, but the ionomer resin may be used in combination with at least one of a thermoplastic elastomer and a diene block copolymer. May be used in combination, or a thermoplastic elastomer or a diene-based block copolymer may be used alone or as a mixture of two or more. As a specific example of the thermoplastic elastomer,
For example, a polyamide-based thermoplastic elastomer commercially available from Toray Industries, Inc. under the trade name "Pebax" (for example, "Pebax 2533"), and a commercial product under the trade name "Hytrel" from Toray DuPont (for example, "Hytrel 3548", "Hytrel 4047") polyester-based thermoplastic elastomers, and polyurethane-based thermoplastic elastomers commercially available from BASF Polyurethane Elastomers under the trade name "Elastolane" (for example, "Elastollan ET880"). Can be

The diene-based block copolymer has a double bond derived from a conjugated diene compound of a block copolymer or a partially hydrogenated block copolymer. The base block copolymer is a block copolymer comprising at least one polymer block A mainly composed of a vinyl aromatic compound and at least one polymer block B mainly composed of a conjugated diene compound. It is. In addition, the partially hydrogenated block copolymer is obtained by hydrogenating the above block copolymer. Examples of the vinyl aromatic compound constituting the block copolymer include styrene,
One or more of α-methylstyrene, vinyltoluene, pt-butylstyrene, 1,1-diphenylstyrene and the like can be selected, and styrene is preferred. As the conjugated diene compound, for example, one or more of butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like can be selected. And combinations thereof. Specific examples of the diene-based block copolymer, for example, Daicel Chemical Industries, Ltd.
(E.g., "Epo Friend A1010") from Kuraray Co., Ltd. (for example, "Epo Friend A1010").
"Septon HG-252) and the like.

The amount of the above-mentioned thermoplastic elastomer, diene-based block copolymer or the like is adjusted according to the amount of the base resin 100 for the cover.
1 to 60 parts by weight, preferably 1 to 35 parts by weight with respect to parts by weight
It is. If the amount is less than 1 part by weight, the effect of lowering the impact at the time of hitting by mixing them becomes insufficient, and if the amount is more than 60 parts by weight, the cover becomes too soft and the resilience decreases, or the compatibility with the ionomer is reduced. And the durability tends to decrease.

In the present invention, the cover composition is required to contain a liquid crystal polymer in addition to the base resin as a main component. The liquid crystal polymer used in the cover composition of the present invention is not particularly limited, but preferably has a cholesteric phase structure in which layers having a nematic phase structure are spirally laminated. Specific examples of such liquid crystal polymers include "Helicone HC Sapphire", "Helicone" available from Wacker Chemie.
ne) HC Scarabeus ",
"Helicone HC Jade (J
ade), "Helicone HC Maple" and the like. From the viewpoint of glitter and color change, "Helicone HC"
"Scarabeus", "Helicone HC Jade"
Is preferred. Since the colors of the reflected light differ depending on the difference in the cholesteric structure, they can be used properly according to a desired color tone. A new color tone can be obtained by blending two or more types.

In such a liquid crystal polymer, a side chain type liquid crystal molecule having a mesogen group in a side chain is arranged in parallel layers, and each layer is twisted and shifted to stack layers having slightly different molecular orientations, thereby forming a spiral shape. It is a polymer that forms a cholesteric phase structure and immobilizes by cross-linking molecules oriented by a polymerization reaction. Since liquid crystals have optical anisotropy, the refractive index for light differs depending on the alignment direction. Since layers having such different refractive indices are spirally stacked, only light in a part of the wavelength region of light incident in a wide spectral region is reflected by light interference effect, and other regions are reflected. Has the characteristic that all wavelengths are transmitted. Therefore, a golf ball containing such a liquid crystal polymer in the cover composition has a brilliancy and an appearance in which the color tone changes depending on the viewpoint.

The compounding amount of the above liquid crystal polymer is required to be 0.1 to 20 parts by weight, preferably 0.3 to 15 parts by weight, based on 100 parts by weight of the base resin of the cover. Preferably it is 0.5 to 10 parts by weight. 0.1
If the amount is less than 20 parts by weight, sufficient glitter and the effect of changing the color tone depending on the viewpoint cannot be obtained. If the amount is more than 20 parts by weight, the weld line becomes conspicuous, and the cost of the obtained golf ball increases. Here, the weld line is
In injection molding, a disadvantage is that partial hardening occurs before the flow of material is completely stopped, resulting in discontinuities inside the part and correspondingly appearing as lines on the part surface.

The above liquid crystal polymer is uniformly dispersed in the cover composition to obtain a desired glittering property and an effect of changing the color tone depending on the viewpoint. It is desirable that the particles have a particle-like structure. The average particle size of the liquid crystal polymer is 5 to 80 μm, preferably 10 to 65 μm, more preferably 15 to 50 μm.
It is desirable that If the average particle size is smaller than 5 μm, the effect of changing the color tone depending on the glitter and the viewpoint cannot be sufficiently obtained, and if it is larger than 80 μm, the dispersibility of the liquid crystal polymer decreases. The thickness of the liquid crystal polymer is
It is desirable that the thickness be 0.5 to 15 μm, preferably 1 to 12 μm, and more preferably 2 to 10 μm. The above thickness is
If it is smaller than 0.5 μm, the effect of changing the color tone depending on the glitter and the viewpoint cannot be sufficiently obtained, and if it is larger than 15 μm, the dispersibility of the liquid crystal polymer decreases.

The golf ball cover of the present invention may further comprise titanium oxide and / or barium sulfate in an amount of 0.05 to 5 parts by weight, preferably 0.1 to 100 parts by weight of the base resin.
４4.5 parts by weight, more preferably 0.2-4 parts by weight. If the amount is outside the above range, a golf ball having the desired appearance cannot be obtained.
That is, the above-mentioned titanium oxide and barium sulfate are white pigments, and based on the white color of a normal golf ball, a golf ball having a brilliancy due to the liquid crystal polymer and having an appearance in which the color tone changes depending on the viewpoint cannot be obtained. .

The cover of the golf ball of the present invention may contain 0 to 5 parts by weight of a fluorescent pigment such as pink, orange, or blue based on 100 parts by weight of the base resin, if necessary.

The golf ball cover of the present invention further contains other additives such as a dispersant, an antioxidant, an ultraviolet absorber, a light stabilizer and the like as long as the desired properties of the golf ball cover are not impaired. May be.

The method for covering the above-mentioned cover is not particularly limited either, and it can be carried out by a usual method for covering a cover. The cover composition is preliminarily formed into a hemispherical shell-like half shell, and two cores are used to wrap the core and pressure-formed at 130 to 170 ° C. for 1 to 5 minutes, or the cover composition is directly cored. A method of wrapping the core by injection molding on it is used. And when forming the cover, if necessary, dimples are formed on the ball surface,
After the cover is formed, a paint finish, a stamp, and the like can be applied as necessary. In the present invention, it is preferable to use a clear paint for the paint finish so that the effect of changing the color tone depending on the glitter and the viewpoint of the liquid crystal polymer contained in the cover is sufficiently obtained.

[0028]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Preparation of core A rubber composition for a core having the composition shown in Table 1 below was kneaded,
38.9mm diameter by heat compression molding at 152 ℃ for 25 minutes
Was obtained.

[0030]

[Table 1]

(Note 1) Hicis-1,4-polybutadiene manufactured by JSR Corporation

Preparation of Cover Composition The cover compositions having the formulations shown in Tables 2 and 3 below were blended using a tumbler blender for about 20 to 40 minutes, extruded with a twin-screw kneading extruder pelletizer, and pelletized. A cover composition was obtained.

[0033]

[Table 2]

[0034]

[Table 3]

(Note 2) Sodium ion neutralized ethylene / methacrylic acid copolymer ionomer resin manufactured by Mitsui Dupont Polychemical Co., Ltd. (Note 3) Zinc ion neutralized ethylene / meta manufactured by Mitsui Dupont Polychemical Co., Ltd. Acrylic acid copolymer ionomer resin (Note 4) Cholesteric liquid crystal polymer manufactured by Wacker Chemie (color: gold when base is black) (Note 5) Cholesteric liquid crystal polymer manufactured by Wacker Chemie (color: base when black) : Green) (Note 6) Fluorescent pigment (pink) manufactured by DAYGLO (Note 7) Mica pigment manufactured by Marl Corporation

[Table 4]

(Examples 1 to 6 and Comparative Examples 1 to 4) A cover layer was formed by coating the above-mentioned cover composition by injection molding around the core obtained as described above, and the mark was formed. Stamp, apply clear paint, diameter
A golf ball having a size of 42.8 mm was obtained. The color tone, the presence or absence of a weld line, and the presence or absence of brilliancy of the obtained golf ball were visually evaluated, and the color tone change from the viewpoint was evaluated according to the following test method. The results were shown in Table 5 (Example) and Table 6. (Comparative Example)

(Test Method) Color Tone Change from Viewpoint The vertex (one fixed point) of the golf ball was visually observed from two directions, front and oblique 45 degrees, to evaluate the presence or absence of a color tone change.

(Test results)

[Table 5]

[0039]

[Table 6]

From the above results, it has been found that the golf balls of Examples 1 to 6 of the present invention both have whiteness and color (pink) golf balls, and have a brilliancy and a change in color tone depending on the viewpoint without a weld line.

On the other hand, in the golf ball of Comparative Example 1 using the cover composition containing only the ionomer resin and titanium oxide, there was no weld line and the moldability was excellent, but the glitter and the color tone from the viewpoint were excellent. No changes were seen.

In the color golf ball of Comparative Example 2 and the white golf ball of Comparative Example 3, since the mica pigment was used for the cover composition, although the glitter was recognized, no change in the color tone from the viewpoint was observed. Furthermore, since a large amount of mica pigment was used, weld lines were observed and moldability was poor.

In the color golf ball of Comparative Example 4, since the mica pigment was used in the composition for the cover, glitter was recognized, but no change in color tone from the viewpoint was observed. Further, although an appropriate amount of mica pigment was used, a weld line was observed due to a small amount of titanium oxide, and the moldability was poor.

[0044]

As described above, the golf ball of the present invention has a brilliancy and a color tone that changes depending on the viewpoint, without impairing the moldability, by using a specific amount of a liquid crystal polymer in the cover composition. Thus, a golf ball having an excellent appearance can be provided.

Claims (4)

[Claims] 1. A golf ball comprising a core and one or more layers of a cover covering the core, wherein the cover is composed of a liquid crystal polymer of 0.1 to 2 with respect to 100 parts by weight of a base resin.
A golf ball formed from a cover composition containing 0 parts by weight. 2. The method according to claim 1, wherein the cover composition comprises a base resin 100
The golf ball according to claim 1, further comprising 0.05 to 5 parts by weight of titanium oxide and / or barium sulfate based on part by weight. 3. The golf ball according to claim 1, wherein the liquid crystal polymer has a cholesteric phase structure. 4. The liquid crystal polymer particles having an average particle size of 5
The golf ball according to any one of claims 1 to 3, wherein the golf ball is a plate-like particle having a thickness of from 0.5 to 80 µm and a thickness of from 0.5 to 15 µm.