JP2001276279A - Paint for golf ball and golf ball using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain paint for a golf ball and the golf ball coated with the paint allowing quick drying after coated without causing high temperatures influencing the surface of the body of the ball while maintaining the adhesion to the body of the ball. SOLUTION: This paint is the paint for a golf ball containing diluent and a film-forming material, and the film-forming material contains a thermosetting resin and an ultraviolet curing resin, preferably at a ratio of 2:8 to 9:1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf ball paint which can provide a coating film having excellent adhesion to a ball body and has a short curing time, and a golf ball using the paint. It is about.

[0002]

2. Description of the Related Art To protect printed marks and numbers, or to improve the appearance by giving gloss, the golf ball surface is coated with a pigmented paint or clear paint. Painted.

[0003] Here, as a paint for golf balls, a paint excellent in impact resistance and abrasion resistance is generally a two-pack type urethane paint obtained by combining a polyol (main component) and a polyisocyanate (curing agent). There is. This coating material is applied with a mixture of a main agent and a curing agent, and is then usually baked to accelerate the curing reaction.

Here, the golf ball body generally comprises a core portion and a cover portion, and it is common to use an ionomer resin as a material for the cover portion. When the ionomer resin is heated to a high temperature, the ionic bonding force is weakened. Therefore, when drying after coating is performed at a high temperature, both the elasticity and the hardness of the ionomer resin decrease. Therefore, it is conceivable to lower the drying temperature, but the curing reaction is slowed down, and the drying takes a long time, and the productivity is reduced. For example, JP-A-8-18277
No. 5 discloses a urethane paint which is blended such that the amount of hydroxyl groups of the polyol is excessive in molar ratio with respect to the amount of isocyanate groups of the polyisocyanate, as a paint having excellent adhesion to the cover. When this urethane paint is dried at a temperature of 40 to 50 ° C., it takes 24 hours or more, resulting in poor productivity. Therefore, golf ball paints having good drying properties have been studied.

In recent years, as a urethane coating having a short drying time, a coating using a prepolymer obtained by reacting a part of a polyol with an isocyanate in advance (hereinafter referred to as "urethane polyol") has been developed. For example, JP-A-9-59566 proposes a golf ball coating using a urethane polyol having a weight average molecular weight of 10,000 to 50,000 having a urethane bond in the main chain and both ends being hydroxyl groups as a polyol. I have.
Since a part of the hydroxyl groups in the polyol has already reacted with the isocyanate group in the state of the coating material to form urethane, the coating material is dried quickly and has excellent productivity. However, in paints using urethane polyols, the free hydroxyl groups and free isocyanate groups in the paints are smaller than those of ordinary urethane paints, so the reactivity with the base material (the ball body surface) decreases, Is reduced.

The present invention has been made in view of such circumstances, and an object of the present invention is to maintain a high temperature at which the surface of the ball body is affected while maintaining the adhesion to the ball body. It is an object of the present invention to provide a golf ball paint that has been dried without being applied quickly, and a golf ball coated with the paint.

[0007]

SUMMARY OF THE INVENTION A golf ball paint of the present invention is a golf ball paint containing a diluent and a film-forming element, wherein the film-forming element comprises a thermosetting resin and an ultraviolet curable resin. Contains resin.

The content ratio of the thermosetting resin to the ultraviolet curing resin (thermosetting resin: ultraviolet curing resin) is 2:
It is preferably 8 to 9: 1.

The golf ball paint according to the present invention includes:
Further, a photopolymerization initiator is preferably contained, and the thermosetting resin is preferably a two-part curable polyurethane composed of a polyol and a polyisocyanate, and further preferably, the polyol is a polyether polyol.

The ultraviolet-curable resin is preferably a polyurethane having a (meth) acryloyl group,
Further, a polyurethane obtained by using a polyether polyol as a constituent component is preferable.

The golf ball of the present invention is obtained by coating the surface of a ball body with the paint of the present invention.

In the specification of the present application, (meth) acryloyl indicates acryloyl or methacryloyl, and (meth) acryl indicates acryl or methacryl.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The paint for golf balls of the present invention comprises:
The composition includes a coating film component and a diluent, and includes a thermosetting resin and an ultraviolet curing resin as the coating film component.

As the thermosetting resin used in the coating film component, a thermosetting resin contained in the coating component of the thermosetting paint conventionally used for forming a clear coating film of a golf ball is used. Resin is used. Specifically, a two-component curable polyurethane using a polyol as a main component and a polyisocyanate as a curing agent is used.

The polyisocyanate compound constituting the thermosetting resin is not particularly limited as long as it has two or more isocyanate groups. For example, hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), hydrogenated Xylylene diisocyanate (H
₆ XDI), isophorone diisocyanate (IPD
I), tetramethylxylylene diisocyanate (TM
XDI), hydrogenated diphenylmethane diisocyanate (H
₁₂ MDI) aliphatic, such as, alicyclic, aromatic, and araliphatic diisocyanate compounds. Of these,
Non-yellowing polyisocyanates (aliphatic and alicyclic polyisocyanates) are preferably used. The paint of the present invention is initially cured by irradiation with ultraviolet rays, as described later. The reason why the irradiation is stopped during the initial curing is to suppress the oxygen in the air due to the irradiation of the ultraviolet ray, which is excited to generate oxygen radicals, which may cause yellowing by acting with isocyanate.

The polyol may be a low molecular weight compound or a high molecular weight compound as long as it has a plurality of hydroxyl groups. Examples of low molecular polyols include diols such as ethylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol; and glycerin. And triols such as trimethylolpropane and hexanetriol. As the high molecular polyol, a polyether polyol obtained by reacting an initiator having an active hydrogen atom with an alkylene oxide; a condensation polyester obtained by dehydration condensation of a dibasic acid such as adipic acid with glycol or triol Polyols; lactone-based polyester polyols obtained by ring-opening polymerization of lactams such as ε-caprolactam; polycarbonate diols synthesized using cyclic diols; polymer polyols such as acrylic polyols obtained by appropriately introducing hydroxyl groups into acrylic copolymers Is mentioned. Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like, examples of the condensation polyester polyol include polyethylene adipate, and examples of the lactone polyester polyol include poly-ε-caprolactone. No. Of these, polyether polyols are preferably used. This is because a coating film containing a large number of ether bonds is flexible and easily follows the deformation of the ball body.

The above polyol and polyisocyanate are used in an equivalent ratio of isocyanate to hydroxyl group (NC
O: OH) is preferably 0.8: 1 to 1.2: 1, and these are preferably mixed immediately before coating. This is because the curing reaction starts after mixing, and even if the ball body is coated in a polyurethane state, the adhesion to the ball body cannot be sufficiently exhibited.

Among the polyurethanes synthesized in this way, polyurethanes having a hydroxyl value of 10 to 120 mgKOH / g and a weight average molecular weight of 4000 to 10000,
It is preferably used in that it has excellent adhesion.

The ultraviolet-curable resin used in the present invention is:
It is a resin having an unsaturated bond (vinyl group, acryloyl group) that initiates a reaction by radicals generated by irradiation with ultraviolet light (250 to 450 nm) to perform three-dimensional crosslinking, and performs radical polymerization. Such an ultraviolet-curable resin can be cured by irradiation with ultraviolet light for a short time to such a degree that it does not become sticky even when touched with a finger (hereinafter, this is referred to as “initial curing”). It can contribute to shortening.

Specifically, unsaturated polyester resins, alkyd resins, special epoxy resins having a (meth) acryloyl group introduced at the molecular terminal (epoxy resins containing (meth) acryloyl), and special polyurethanes (polyurethane containing (meth) acryloyl) And the like. Of these, polyurethanes containing (meth) acryloyl groups are preferably used. This is because a resin having an acryloyl group or a methacryloyl group can reduce the curing time since air inhibition during curing is small. In addition, since the (meth) acryloyl group has an affinity for a resin containing a carboxyl group such as an ionomer, when the ball body surface layer is made of a material containing an ionomer, more excellent adhesion is obtained. Can be shown. Furthermore, a coating film having a urethane bond is richer in flexibility than other three-dimensionally crosslinked coating films, and can follow the deformation at the time of hitting a ball to suppress peeling of the coating film. Further, it is preferable that the resin has an ether bond. Specifically, it is preferable to use a polyether polyol as a polyol component forming urethane. This is because the urethane coating film having an ether bond is flexible, easily follows the deformation of the ball body, and the coating film does not easily peel off.

The mixing ratio between the thermosetting resin and the ultraviolet-curable resin (thermosetting paint / ultraviolet-curable paint) is 2/8.
Above, preferably 5/5 or more. The upper limit is 9 /
1, preferably 7.5 / 2.5. The mixing ratio is 2 /
If the number is less than 8, that is, if the amount of the thermosetting paint is small, the adhesiveness is reduced. When the ratio exceeds 9/1, that is, when the amount of the thermosetting paint increases, not only the initial curing time becomes longer,
This is because the discoloration of the thermosetting paint due to ultraviolet irradiation becomes conspicuous, and the transparency of the clear coating film is impaired.

The mixing of the thermosetting resin and the ultraviolet curable resin is preferably performed immediately before coating. When a functional group (for example, an epoxy group or an acryloyl group) contained in the ultraviolet curable resin reacts with a functional group (for example, an alcoholic hydroxyl group and an isocyanate group in the case of polyurethane) contained in the thermosetting resin. Because there is also.

The diluent used in the coating material of the present invention may be a radical polymerizable monomer which undergoes a cross-linking reaction with the ultraviolet-curable resin, or may be an organic solvent.

Examples of the radical polymerizable monomer include vinyl compounds such as styrene; and unsaturated monobasic acids such as acrylic acid, methacrylic acid, crotonic acid, and cinnamic acid. This is because these radical polymerizable monomers also react with the ultraviolet curable resin to accelerate the crosslinking reaction.

Examples of the organic solvent include hydrocarbons such as toluene and xylene; cellosolves such as cellosolve and butyl cellosolve; carbitols such as carbitol and butyl carbitol; cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate and the like. Esters; ketones such as methyl ethyl ketone; ethers such as diethylene glycol dimethyl ether; and the like, and two or more kinds thereof may be used in combination. Two or more kinds of mixed organic solvents may be used as a common solvent for the thermosetting resin and the ultraviolet curable resin, or two or more kinds of mixed solvents may be mixed by mixing each resin dispersed in a different solvent. You may make it become.

By using a diluent, particularly a solvent, the thermosetting resin and the ultraviolet-curable resin can be mixed at the molecular level, which contributes to increasing the strength of the coating film and making the ultraviolet-curing reaction uniform. In this regard, in the paint described in Japanese Patent Publication No. 6-59334, it is considered that a relatively low molecular weight monomer or oligomer containing an acryloyl group plays a role of a diluent. This is because, in addition to the fact that the odor is generally strong, it is difficult to mix the thermosetting resin and the ultraviolet curable resin at a satisfactory molecular level, and it is not possible to mix uniformly as the curing reaction progresses. .

The coating of the present invention preferably contains a photopolymerization initiator in order to enhance the photocurability of the ultraviolet-curable resin.

Examples of photopolymerization initiators include benzoin such as benzoin, benzoin methyl ether and benzoin ethyl ether and their alkyl ethers; acetophenone such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone. Anthraquinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone and 1-chloroanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone and 2-chlorothioxanthone ;
Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one and 2-benzyl-2-dimethyl Amino-1- (4-morpholinophenyl) -butanone-1; acylphosphine oxides and xanthones; a complex of diazonium and Lewis acid, and the like, which may be selected according to the type of ultraviolet-curable resin. For example, when the thermosetting resin is an acryloyl-containing polyurethane, 2-hydroxy-2
-Methyl-1-phenylpropan-1-one and 1-hydroxy-cyclohexyl-phenyl ketone are preferably used.

The paint of the present invention may optionally contain
Further, an ultraviolet absorber, a light stabilizer, a slip agent, a fluorescent whitening agent, and another polymer may be contained. As another polymer, a polyester polyol is preferably used.

The golf ball paint of the present invention having the above-mentioned structure can be applied by using a conventionally known coating method, spray coating, brush coating, paint gun or the like.

After the coating, the initial curing of the paint is completed by irradiating ultraviolet rays to cure the ultraviolet curable resin.

As the ultraviolet light source, commercially available mercury lamps, arc lamps, xenon lamps and the like can be used.

The ultraviolet irradiation time is about 0.7 to 2.2 seconds. Generally, the higher the proportion of the thermosetting resin content, the longer the irradiation time. The curing of the ultraviolet curable resin is completed by the irradiation of the ultraviolet light. Therefore, even when the thermosetting resin is hardly hardened, stickiness when a finger comes into contact is eliminated. Therefore, the painted material does not fall off the surface of the ball body, so that it is only necessary to leave the ball and leave it still. During the standing or standing, the curing reaction of the thermosetting resin proceeds. Of course, in order to shorten the standing time, heating may be performed at about 30 to 50 ° C.

The golf ball of the present invention is obtained by forming a cured film of the golf ball paint of the present invention having the above composition on the surface of a ball body.

The ball body used in the present invention is a sphere made of vulcanized rubber in the case of a one-piece golf ball;
In the case of a multi-piece golf ball having at least one layer of a core and at least one layer of a cover, the core and the cover; in the case of a thread wound golf ball, a thread rubber is wound around a liquid center or a solid center, and one or more layers are wound thereon. Covered with a cover.

The material of the core constituting the ball body is not particularly limited. The cover may be made of a natural material such as balata, a synthetic resin such as an ionomer or an elastomer, or a blend thereof, but is preferably a material containing an ionomer. This is because the ionomer has a carboxyl group, has excellent affinity with the paint of the present invention, and has a large effect of improving the adhesion.

The above-mentioned ball body may be subjected to a surface roughening treatment known to those skilled in the art, such as a sand blasting treatment, a shot blasting treatment, and a buff polishing, before the paint is applied. Such a roughening treatment can physically improve the adhesion to the coating film.

The coating amount of the ball coating is preferably such that the thickness of the formed coating film is about several μm to several tens μm.

After applying the coating material of the present invention, ultraviolet irradiation,
If necessary, it is cured by heating after irradiation. The cured film is a three-dimensionally crosslinked product of a thermosetting resin and an ultraviolet curable resin that were included as constituent elements of the coating film.

[0040]

Examples [Evaluation method] (1) Drying property Ultraviolet irradiation time required for initial curing The ultraviolet irradiation time (second) required for the state of initial curing (a level at which no fingerprint remains even when touched with a finger) was measured.

Discoloration at the time of initial curing The chromaticity after coating and after ultraviolet curing was measured for Lab value with a color difference meter (CR-221 manufactured by Minolta). L after coating
The ab value and the change value of the Lab value during the initial curing (ΔL, Δa,
Δb) was substituted into the following equation, and when the calculated value E was 1 or more, it was considered that there was discoloration. E = [(ΔL) ² + (Δa) ² + (Δb) ² ] ^1/2

(2) Coating Film Adhesion Dry State A golf ball was hit 100 times using a driver-type club on a swing machine manufactured by True Temper Co., Ltd. The ball after hitting is visually observed, and according to the degree of peeling of the coating film, （(no cracking, no peeling), （(crack occurs in two or three places, but no peeling), 3 to 10 places, but the total peeling area is less than 0.5 cm ² ), ×
(Although cracks are generated at 10 or more places, the total area of peeling is 0.
5 cm ² or more).

Wet state After the golf ball was immersed in water for 3 days, the test was performed in the same manner as in the dry state. Based on the peeled state, ◎ (no peeling), ○ (total area of peeling was 0) .2cm ²
), Δ (total area of peeling is 0.2 cm ² or more and less than 0.5 cm ² ), × (total peeling area is 0.5 c
It was evaluated in four stages of m ² or more at a).

[Preparation of Thermosetting Resin] Preparation of Main Agent PolyTHF650 (BASF) as a polyol was dissolved in a solvent (toluene and methyl ethyl ketone) in an amount of 116 parts by mass, and dibutyltin laurate was added as a catalyst to the main agent in an amount of 0.1 part by mass. It was added so as to be 1% by mass. While maintaining the polyol solution at 80 ° C., 48 parts by mass of isophorone diisocyanate was dropped and mixed to form a urethane polyol (solid content: 60% by mass, weight average molecular weight: 78).
50, hydroxyl number 87) were synthesized.

Synthesis of Polyurethane NCO / OH (equivalent ratio) with respect to the main agent prepared above
Was added to obtain a polyurethane resin by stirring for 1 minute after adding triphorone diisocyanate (manufactured by Sumitomo Bayer Urethane).

[Preparation of UV Curable Resin] A diol “PolyTHF25” commercially available from BASF Japan
0 "and isophorone diisocyanate commercially available from Sumitomo Bayern Urethane Co., Ltd. at an equivalent ratio of 2: 3. Dibutyltin dilaurate was added as a catalyst in a mass ratio of 0.1% to diol, and the solvent was further added. A mixed solvent of toluene and methyl ethyl ketone was used. In this state, the mixture was reacted at 70 ° C. for 1 hour under a nitrogen stream to synthesize a polyurethane. Then, pentaerythritol triacrylate commercially available from Kyoei Chemical Co.,
And reacted for 2 hours to prepare a polyurethane having an acryloyl group introduced into a terminal (acryloyl-containing polyurethane).

[Production of Golf Ball] Ball Body A golf ball body having a vulcanized rubber core having a diameter of 38.3 mm covered with an ionomer cover was used.

Production of Clear Coating Film The thermosetting paint and the ultraviolet-curable paint prepared above were
They were mixed at the ratios shown in Table 1 and painted on the ball body surface with an air gun. The coating amount is 70 to 200 mg, which is an amount that gives a coating film of about 10 μm.

An 80 W / cm lamp was placed at a position 70 mm away from the applied ball, and irradiated with ultraviolet light for the time required for initial curing. Then, it was left still until it was completely cured (at room temperature to 50 ° C. for 1 to 24 hours).

With respect to the manufactured golf balls, paint drying property, coating film adhesion property, and discoloration resistance were evaluated based on the above evaluation methods. Table 1 shows the results.

The mixing ratio in Table 1 indicates "thermosetting resin: ultraviolet curable resin".

[0052]

[Table 1]

The greater the proportion of the thermosetting resin, the longer the initial curing time and poor finger contact. Further, when the ratio of the thermosetting resin / ultraviolet curable resin was 9.5 / 0.5 or more, the ratio of the thermosetting resin was too high, and the discoloration was conspicuous (Nos. 9, 10). On the other hand, with respect to the coating film adhesion, the smaller the proportion of the UV-curable paint is, the better,
In order to ensure that there is no problem in adhesion, the ratio of thermosetting resin / ultraviolet curing resin needs to be 2/8 or more (Nos. 3, 4), and is excellent when it is larger than 5/5. (Nos. 5 to 10).

Therefore, in order to satisfy the drying property and the coating film adhesion, the ratio of thermosetting resin / ultraviolet curing resin is
It turns out that it is preferable to set it to 2 / 8-9 / 1.

[0055]

The golf ball paint of the present invention uses a UV-curable resin which can be initially cured in a short time and a thermosetting resin having excellent adhesion as a coating film component, so that it can be dried in a short time. And excellent adhesion.

Since the golf ball of the present invention uses the golf ball paint of the present invention having the above-described effects, it is excellent in productivity and coating film durability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 175/04 C09D 175/04 175/08 175/08 175/14 175/14 201/00 201/00 ( 72) Inventor Masatoshi Takahashi 3-6-9, Wakihama-cho, Chuo-ku, Kobe City, Hyogo Prefecture Inside Sumitomo Rubber Industries Co., Ltd. In-house F term (reference) 4D075 CA02 CA04 CA13 CB04 DA23 DB36 DB42 DC38 EA07 EA19 EA21 EB14 EB22 EB24 EB38 EC37 4J038 DB371 DB372 DD121 DD122 DD182 DG051 DG052 DG111 DG112 DG121 DG131 DG131 DG132 DG131 DG132 DG191 NA23 PA17 PA19 PB02 PC08

Claims (8)

[Claims] 1. A golf ball paint comprising a diluent and a film-forming element, wherein the film-forming element comprises a thermosetting resin and an ultraviolet curable resin. 2. The content ratio of the thermosetting resin to the ultraviolet curable resin (thermosetting resin: ultraviolet curable resin) is as follows:
2. The golf ball paint according to claim 1, wherein the ratio is 2: 8 to 9: 1. 3. The golf ball paint according to claim 1, further comprising a photopolymerization initiator. 4. The golf ball paint according to claim 1, wherein the thermosetting resin is a two-component curable polyurethane composed of a polyol and a polyisocyanate. 5. The golf ball paint according to claim 4, wherein the polyol is a polyether polyol. 6. The golf ball paint according to claim 1, wherein the ultraviolet curable resin is a polyurethane having a (meth) acryloyl group. 7. The golf ball paint according to claim 1, wherein the ultraviolet curable resin is a polyurethane obtained by using a polyether polyol as a constituent component. 8. A golf ball having the ball body surface coated with the paint according to claim 1.