JP2019098150A - Golf ball - Google Patents

Abstract

To provide a golf ball which achieves preferable striking feeling of a driver shot, enhances control ability to approach shot from the rough, and is excellent in contamination resistance and striking feeling.SOLUTION: A golf ball of the invention comprises: a golf ball body; and a coating film for covering the golf ball body, in which 10% modulus of the coating film is 75 kgf/cmor smaller, storage elastic modulus (E') at 150°C obtained by measuring dynamic viscoelasticity of the coating film is 1.0×10Pa or greater, and a push-in depth of the coating film measured by using a nano indenter in a state of being provided on the golf ball body surface is 1250 nm or greater. A diameter of the golf ball is 40 mm to 45 mm, and a compression deformation amount from a state in which an initial load of 98 N is applied to the golf ball to a state in which a final load of 1275 N is applied, is greater than 3.0 mm.SELECTED DRAWING: None

Description

  The present invention relates to a technology for improving the spin performance of a golf ball.

  A coating film is provided on the surface of the golf ball body. It has been proposed to improve the properties of golf balls by improving the coating.

Patent Document 1 includes a core, a cover located outside the core, and a paint layer located outside the cover, wherein the Shore D hardness of the cover is 61 or less, and the martens of the paint layer is A golf ball having a hardness of 2.0 mgf / μm ² or less is disclosed. The golf ball of Patent Document 1 is excellent in spin performance, stability of spin speed, and durability of a paint layer.

Patent Document 2 describes a golf ball having a golf ball body and a coating film provided on the surface of the golf ball body, wherein the coating film has a Martens hardness of 2.0 mgf / μm ² or less, and a 10% modulus. A golf ball is disclosed that has a ratio of 50% modulus to 50% (50% modulus / 10% modulus) of 1.6 or more. The golf ball of Patent Document 2 has a high spin rate on approach shots under wet conditions and rough conditions.

  Patent Documents 3 and 4 propose golf balls that are easy to stop by increasing the launch angle of the golf ball. Patent Document 3 discloses a golf ball having a golf ball body and a paint layer covering the surface of the golf ball body, wherein the resin component constituting the paint layer is cured with a polyamide-based curing agent. And a golf ball having a coefficient of static friction of 0.22 or less. Patent Document 4 discloses a golf ball having a golf ball body and a coating film for covering the golf ball body, wherein the coating film contains metal particles.

Patent Document 5 proposes a golf ball having improved durability and scratch resistance, and having a core and a cover, and one or more layers of paint formed on the cover, wherein the Shore D hardness of the cover is 50-65, a flexural modulus of 1000~2000kgf / cm ^2, the golf ball of at least the outermost layer of the 10% modulus and excellent durability, which is a 5~50kgf / cm ² of the paint disclosed It is done.

Patent Document 6 proposes a golf ball having an improved spin retention rate without sacrificing the required properties of a coating. Patent Document 6 discloses a core and at least one cover covering the core, and a golf ball having a coating formed on the outer surface of the cover, wherein the coating has a thickness of 25 μm to 125 μm. When the thickness of the outermost cover is CL (mm) and the thickness of the coating film is PL (μm) in the range where the 50% modulus of the film is 5 MPa or more and 50 MPa or less, it is expressed by the following formula (1) A golf ball is disclosed in which R is in the range of 0.01 or more and 0.5 or less.
R = PL / CL / 1000 (1)

Patent Document 7 proposes a golf ball which has high controllability for approach shots less than 40 yards, can reduce the spin amount on driver shots, and has an excellent feel at impact. Patent Document 7 shows a golf ball having a golf ball body and a coating film provided on the surface of the golf ball body, wherein the coating film is measured at 120 ° C. under the following conditions by a dynamic viscoelasticity device. The storage elastic modulus (E ') in the temperature range of -150 ° C. is 1.00 × 10 ⁷ dyn / cm ² or more and 1.00 × 10 ⁸ dyn / cm ² or less, and the loss tangent at 10 ° C. ( It is characterized in that tan δ) is 0.050 or more.
<Measurement conditions>
Measurement mode: Tension Measurement temperature: -50 ° C to 150 ° C
Heating rate: 4 ° C / division Vibration frequency: 10Hz
Measurement distortion: 0.1%

JP, 2011-67595, A JP, 2011-217820, A JP, 2006-75209, A Unexamined-Japanese-Patent No. 2006-75210 JP 2000-288125 A JP 2003-265650 A JP 2014-14383 A

  It goes without saying that not only the flight distance of the driver shot but also the accuracy of the approach shot is important for making a score for golf. Patent Document 7 proposes a golf ball with improved controllability to approach shots in a dry condition from around the green of less than 40 yards, particularly about 10 yards to 20 yards, for example, approach shots from the rough There is no study to increase the spin amount of Furthermore, when the coating film is softened to increase the spin amount of approach shots, there has been a problem that it is easily soiled against grass juice, muddy water and the like.

  In order to enhance the feel at impact of driver shots, golf balls having a large amount of compressive deformation, in particular, tend to reduce the spin amount of approach shots from the rough.

  The present invention has been made in view of the above-mentioned circumstances, and provides a golf ball having good hit feeling of driver shots, improved controllability to approach shots from the rough, and excellent contamination resistance and hit feeling. To be an issue.

The golf ball of the present invention is a golf ball having a golf ball body and a coating film for covering the golf ball body, wherein the 10% modulus of the coating film is 75 kgf / cm ² or less, and the coating film The storage elastic modulus (E ' ₁₅₀ ) of 150 ° C. obtained by measuring the dynamic viscoelasticity of E is 1.0 × 10 ⁷ Pa or more, and is provided on the surface of the golf ball body using a nano indenter. The indentation depth of the coating film measured is 1250 nm or more, the diameter of the golf ball is 40 mm to 45 mm, from the state where the initial load 98 N is applied to the golf ball to the time when the final load 1275 N is applied. It is characterized in that the amount of compressive deformation is more than 3.0 mm.

  According to the present invention, it is possible to obtain a golf ball which has a good feel at impact on driver shots, a high controllability to approach shots from the rough, and an excellent contamination resistance and feel at impact.

Explanatory drawing which shows the molecular structure of an example of the polyrotaxane used by this invention. FIG. 1 is a partially cutaway cross-sectional view of a golf ball according to an embodiment of the present invention. Explanatory drawing which illustrates the aspect which forms a slit in wet paper. The schematic diagram which shows an example of the coating form which used the air gun. Coating film No. The graph which shows the dynamic viscoelasticity of 1. Coating film No. The graph which shows the dynamic viscoelasticity of 2. Coating film No. The graph which shows the dynamic viscoelasticity of 3. Coating film No. The graph which shows the dynamic viscoelasticity of 4. Coating film No. 5 is a graph showing the dynamic viscoelasticity of 5. Coating film No. 6 to No. The graph which shows the relationship between the storage elastic modulus (E ') of 8, and temperature. Coating film No. 6 to No. The graph which shows the relationship between the loss elastic modulus (E ") of 8, and temperature. Coating film No. 6 to No. The graph which shows the relationship between the loss tangent (tan δ) of 8, and temperature.

The golf ball of the present invention is a golf ball having a golf ball body and a coating film for covering the golf ball body, wherein the 10% modulus of the coating film is 75 kgf / cm ² or less, and the coating film storage modulus measuring the dynamic viscoelasticity of 150 obtained ° C. (E ') is not less 1.0 × 10 7 ^Pa or more, in a state that is provided to the golf ball body surface, using nano indenter The indentation depth of the coating film measured is 1250 nm or more, the diameter of the golf ball is 40 mm to 45 mm, and compression from the state where the initial load 98 N is applied to the golf ball to the time when the final load 1275 N is applied. It is characterized in that the amount of deformation is more than 3.0 mm.

  The present inventors measure the temperature change of the storage elastic modulus (E ') of the coating film using a dynamic viscoelastic device, and in the low temperature region, there is almost no difference in the storage elastic modulus (E') Even in the case of a coating film, a difference in storage modulus occurs in a high temperature range of 120 ° C. to 150 ° C., and an approach shot with a storage modulus (E ′) of less than 40 yards in the temperature range of 120 ° C. to 150 ° C. Is found to affect the spin performance of

In the golf ball of the present invention, by using a coating having a storage elastic modulus (E ′ ₁₅₀ ) at 150 ° C. obtained by measuring the dynamic viscoelasticity of the coating of 1.00 × 10 ⁷ Pa or more, In approach shots less than 40 yards, the launch angle can be low and the spin rate can be high. As a result, the golf ball of the present invention has high controllability of approach shots less than 40 yards. In this respect, the storage elastic modulus (E ′ ₁₅₀ ) at 150 ° C. is preferably 1.20 × 10 ⁷ Pa or more, and more preferably 1.50 × 10 ⁷ Pa or more. The storage elastic modulus (E ′ ₁₅₀ ) at 150 ° C. is preferably 1.00 × 10 ⁸ Pa or less, more preferably 9.00 × 10 ⁷ Pa or less, and 8.00 × 10 ⁷ Pa. More preferably, it is Pa or less.

In the golf ball of the present invention, it is preferable to have a flat region in which the storage elastic modulus (E ′) is substantially constant in the region of 120 ° C. to 150 ° C. when the dynamic viscoelasticity of the coating is measured. From this viewpoint, the storage elastic modulus (E ′ ₁₂₀ ) at 120 ° C. measured using a dynamic visco-elastic apparatus is preferably 1.00 × 10 ⁷ Pa or more, and 1.20 × 10 ⁷ Pa or more Is more preferably 1.50 × 10 ⁷ Pa or more. Further, the storage elastic modulus (E ' ₁₂₀ ) at 120 ° C. is preferably 9.00 × 10 ⁷ Pa or less, more preferably 8.00 × 10 ⁷ Pa or less.

  In the golf ball of the present invention, when the dynamic viscoelasticity of the coating is measured, the peak temperature of the loss tangent tan δ is preferably 60 ° C. or less, more preferably 56 ° C. or less, and 50 ° C. or less Is more preferably 40.degree. C. or less, particularly preferably -40.degree. C. or more, more preferably -35.degree. C. or more, and still more preferably -30.degree. C. or more. If the peak temperature of the loss tangent (tan δ) is within the above-mentioned range, the viscosity becomes dominant at the approach shot and a good hit feeling is obtained.

  In the golf ball of the present invention, the peak height of the loss tangent tan δ obtained by measuring the dynamic viscoelasticity of the coating is less than 0.8, and preferably 0.79 or less. It is more preferable that If the peak height of the loss tangent (tan δ) is less than 0.8, the energy transfer efficiency is improved, the shear force is increased, and the spin performance is improved. The peak height of the loss tangent tan δ is preferably 0.3 or more, more preferably 0.31 or more, and still more preferably 0.32 or more. By using a coating having a loss tangent (tan δ) peak height of 0.3 or more, the launch angle can be reduced and the spin amount can be increased in approach shots less than 40 yards.

10% modulus of the coating film covering the golf ball body of the present invention is preferably 75 kgf / cm ² or less, more preferably 60 kgf / cm ² or less, more preferably 30 kgf / cm ² or less. If the 10% modulus of the coating is 75 kgf / cm ² or less, the coating is soft and the spin amount of approach shot is high. The lower limit of the 10% modulus of the coating film is not particularly limited, but 2 kgf / cm ² is preferable, 8 kgf / cm ² is more preferable, 10 kgf / cm ² is more preferable, and 12 kgf / cm ² is particularly preferable. If the 10% modulus is too small, it becomes too soft, leaving a feeling of tack and feeling worse.

  A film for measurement of the dynamic viscoelasticity and 10% modulus of the coating film is produced under the predetermined conditions from the paint composition forming the film, and the dynamic viscoelasticity and 10% modulus of the film for measurement are measured. . The method of producing the film for measurement and the method of measurement will be described later.

The golf ball of the present invention has a golf ball body and a coating film provided on the surface of the golf ball body, and the coating film is measured using a nanoindenter in a state where the coating film is provided on the surface of the golf ball body. The indentation depth is preferably 1250 nm or more, more preferably 1800 nm or more, and still more preferably 2000 nm or more.
The upper limit of the indentation depth of the coating film measured using a nanoindenter is not particularly limited, but is preferably 4000 nm or less, more preferably 3000 nm or less, and still more preferably 2800 nm or less. The indentation depth measured using a nano indenter directly indicates the physical properties of the coating provided on the golf ball body. When the indentation depth of the coating film measured using a nano indenter is smaller than 1250 nm, the feel at impact of the approach (including I # 8) deteriorates. If the thickness is more than 4000 nm, the deformation is too large, and the tackiness is too much.

  The resin component of the coating film of the golf ball of the present invention preferably contains a polyurethane having (A) a polyisocyanate component and (B) a polyol component containing a polyrotaxane as constituent components. The resin component of the coating film of the golf ball of the present invention more preferably contains a polyurethane obtained by reacting the (A) polyisocyanate component and the (B) polyrotaxane-containing polyol component.

  (A) As the polyisocyanate, for example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (TDI), 4,4'-diphenylmethane Diisocyanate (MDI), 1,5-Naphthylene Diisocyanate (NDI), 3,3'-Bitrylene-4,4'-Diisocyanate (TODI), Xylylene Diisocyanate (XDI), Tetramethyl xylylene Diisocyanate (TMXDI), Para Aromatic polyisocyanates such as phenylene diisocyanate (PPDI); 4,4'-dicyclohexylmethane diisocyanate (H12MDI), hydrogenated xylylene diisocyanate (H6XDI), hexamethylene diisocyanate It includes derivatives of, and these polyisocyanates; sulfonate (HDI), isophorone diisocyanate (IPDI), alicyclic polyisocyanates or aliphatic polyisocyanates such as norbornene diisocyanate (NBDI). In the present invention, it is preferable to use two or more polyisocyanates as the polyisocyanate.

Examples of derivatives of the polyisocyanate include: isocyanurate of diisocyanate; adduct obtained by reacting diisocyanate and trimethylolpropane or low molecular weight triol such as glycerin; modified allophanate; modified burette etc. It is more preferable that free diisocyanate is removed. The allophanate-modified product is, for example, a trifunctional polyisocyanate obtained by further reacting diisocyanate with a urethane bond formed by reacting diisocyanate and a low molecular weight diol. The burette modified body is, for example, a trifunctional polyisocyanate having a burette bond represented by the following formula (1). The isocyanurate of diisocyanate is, for example, a trifunctional polyisocyanate represented by the following formula (2).
In formulas (1) and (2), R represents a residue obtained by removing an isocyanate group from diisocyanate.

  In the present invention, it is preferable to use a derivative of hexamethylene diisocyanate and a derivative of isophorone diisocyanate as the polyisocyanate. As a derivative of hexamethylene diisocyanate, it is preferable to use an isocyanurate modified product of hexamethylene diisocyanate. As a derivative of isophorone diisocyanate, isocyanurate modified isophorone diisocyanate is preferably used.

  The mixing ratio of the derivative of hexamethylene diisocyanate to the derivative of isophorone diisocyanate (HDI derivative / IPDI derivative) is preferably 90/10 or less, more preferably 80/20 or less, still more preferably 75/25 or less in mass ratio 10/90 or more is preferable, 30/70 or more is more preferable, and 45/55 or more is more preferable.

  (A) 0.5 mass% or more is preferable, 1 mass% or more is more preferable, 2 mass% or more is more preferable, 45 mass% or less is preferable, and the amount of isocyanate groups (NCO%) of the said polyisocyanate is 40 mass%. % Or less is more preferable, and 35 mass% or less is more preferable. The isocyanate group content (NCO%) of the polyisocyanate can be represented by 100 × [mole number of isocyanate group in polyisocyanate × 42 (molecular weight of NCO)] / total mass (g) of polyisocyanate.

  Specific examples of the polyisocyanate include Burnoc D-800, Burnoc DN-950, Burnoc DN-955 manufactured by DIC, Desmodur N75MPA / X manufactured by Sumika Bayer Urethane Co., Desmodur N3300, Desmodur L75 (C), Sumidul E21-1, Coronate HX, Nippon Polyurethane Industry Co., Coronate HK, Duranate 24A-100, Duranate 21S-75E, Duranate TPA-100, Duranate TKA-100, Degussa VESTANAT T1890, etc. Can.

  Next, the polyol component containing (B) polyrotaxane will be described. The polyrotaxane comprises a cyclodextrin, a linear molecule which skews the cyclic structure of the cyclodextrin, and a blocking group which is disposed at both ends of the linear molecule and which prevents the elimination of the cyclic molecule. Have. Polyrotaxanes have visco-elasticity because cyclodextrin molecules, which are pierced in a linear manner and can be moved along the linear molecules (a pulley effect), have a pulley effect even when tension is applied. Can disperse the tension uniformly. In the present invention, the polyol component is not particularly limited as long as it has a plurality of hydroxyl groups, and a plurality of hydroxyl groups capable of reacting with isocyanate groups are present in the cyclic structure of cyclodextrin, Polyrotaxane is a polyol component.

  The cyclodextrin is a generic term for an oligosaccharide having a cyclic structure. The cyclodextrin is, for example, one in which 6 to 8 D-glucopyranose residues are cyclically linked by an α-1,4-glucosidic bond. Examples of cyclodextrin include α-cyclodextrin (number of glucose: 6), β-cyclodextrin (number of glucose: 7), γ-cyclodextrin (number of glucose: 8), etc. preferable. The cyclodextrin may be used alone or in combination of two or more.

  The linear molecule is preferably a linear molecule which penetrates the cyclic structure of cyclodextrin in a skewer-like manner so as to be rotatable. Examples of the linear molecule include polyalkylenes, polyesters, polyethers and polyacrylics. Among these, polyethers are preferable, and polyethylene glycol is particularly preferable. Polyethylene glycol is less sterically hindered and can penetrate the cyclodextrin cyclic structure in a skewer-like manner.

  5,000 or more are preferable, as for the weight average molecular weight of the said linear molecule, 6,000 or more are more preferable, 100,000 or less are preferable, and 80,000 or less are more preferable.

  The linear molecule preferably has a functional group at both ends. By having a functional group, it can be easily reacted with the blocking group. As said functional group, a hydroxyl group, a carboxyl group, an amino group, a thiol group etc. are mentioned.

  The blocking group is not particularly limited as long as it is disposed at both ends of the linear molecule and can prevent cyclodextrin from being detached from the linear molecule. As a method of preventing the elimination, a method of physically preventing the elimination by using a bulky blocking group and a method of preventing the elimination electrostatically by using the ionic blocking group can be mentioned. Examples of the bulky blocking group include cyclodextrin, adamantyl group and the like. The number of cyclodextrins to be penetrated into a linear molecule is preferably 0.06 to 0.61, more preferably 0.11 to 0.48, and most preferably 0.24 to 0.41, where the maximum number is 1. Is more preferred. If it is less than 0.06, the pulley effect may not be exhibited, and if it exceeds 0.61, cyclodextrin may be arranged too densely, and the mobility of cyclodextrin may be reduced.

  As polyrotaxane used by this invention, that by which at least one part of the hydroxyl group which cyclodextrin has is modified | denatured by the caprolactone chain is preferable. The caprolactone modification improves the compatibility with the polyurethane. In addition, the caprolactone modification improves the flexibility of the polyrotaxane, and the spin performance of the approach shot improves.

As the modification, for example, the hydroxyl group of cyclodextrin is treated with propylene oxide to be hydroxypropylated. Subsequently, ε-caprolactone is added to carry out ring-opening polymerization. This modification, on the outside of the ring structure of cyclodextrin, polycaprolactone chain _{- (CO (CH 2) 5} O) nH (n is a natural number of 1 to 100) is a _{-O-C 3} H 6 -O- groups Through. n represents the degree of polymerization, and is preferably a natural number of 1 to 100, more preferably a natural number of 2 to 70, and still more preferably a natural number of 3 to 40. At the other end of the caprolactone chain, a hydroxyl group is formed by ring-opening polymerization.

  The ratio of the hydroxyl group modified with a caprolactone chain is preferably 2 mol% or more, more preferably 5 mol% or more, and further preferably 10 mol% or more with respect to the total hydroxyl groups (100 mol%) of the cyclodextrin before modification. preferable. If the proportion of hydroxyl groups modified with caprolactone chains is in the above range, the flexibility of the polyrotaxane is increased, and the spin performance under wet conditions is further improved.

FIG. 1 is an explanatory view showing an example of the molecular structure of polyrotaxane used in the present invention. The polyrotaxane 200 is disposed at both ends of the cyclodextrin 212, a linear molecule 214 that skews the cyclic structure of the cyclodextrin 212, and the linear molecule 214, and prevents the detachment of the cyclic molecule. And a blocking group 216. On the outside of the ring structure of cyclodextrin, polycaprolactone chain 218, which is attached via a _{-O-C 3} H 6 -O- group (not shown).

  The hydroxyl value of the polyrotaxane is preferably 10 mg KOH / g or more, more preferably 15 mg KOH / g or more, still more preferably 20 mg KOH / g or more, preferably 400 mg KOH / g or less, more preferably 300 mg KOH / g or less, more preferably It is at most 220 mg KOH / g, particularly preferably at most 180 mg KOH / g. If the hydroxyl value of the polyrotaxane is in the above range, the reactivity with the polyisocyanate becomes high, and the durability of the coating film becomes good. The hydroxyl value can be measured, for example, by an acetylation method according to JIS K 1557-1.

  The weight average molecular weight of the total molecular weight of the polyrotaxane is preferably 30,000 or more, more preferably 40,000 or more, still more preferably 50,000 or more, and preferably 3,000,000 or less, more preferably 2 , 500,000 or less, more preferably 2,000,000 or less. When the weight average molecular weight is 30,000 or more, the coating film has sufficient strength, and when it is 3,000,000 or less, the coating film has sufficient softness, and the approach performance of the golf ball is It is because it improves. The weight average molecular weight is, for example, polystyrene as a standard substance by gel permeation chromatography (GPC), tetrahydrofuran as an eluent, and a column for organic solvent-based GPC as a column (for example, “Shodex (registered trademark) KF manufactured by Showa Denko KK) It may be measured using a series, etc.).

  As a specific example of the polyrotaxane modified with polycaprolactone, Celm (registered trademark) super polymers SH3400P, SH2400P, SH1310P and the like manufactured by Advanced Soft Materials can be mentioned.

  (B) The polyol component may further contain another polyol component. The other polyol component is not particularly limited as long as it has a plurality of hydroxyl groups, and examples thereof include low molecular weight polyols and high molecular weight polyols.

  Examples of low molecular weight polyols include ethylene glycol, diethylene glycol, triethylene glycol, propanediol (eg, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, etc.) Propylene glycol, butanediol (eg, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,3-dimethyl-2,3-butanediol etc.) , Neopentyl glycol, pentanediol, hexanediol, heptanediol, octanediol, 1,4-cyclohexanedimethylol, aniline-based diols, diols such as bisphenol A-based diols; glycerin such as trimethylolpropane and hexanetriol Lumpur; pentaerythritol, tetraol or a hexanol such as sorbitol.

  Examples of high molecular weight polyols include polyether polyols such as polyoxyethylene glycol (PEG), polyoxypropylene glycol (PPG), polyoxytetramethylene glycol (PTMG); polyethylene adipate (PEA), polybutylene adipate (PBA) Condensed polyester polyols such as polyhexamethylene adipate (PHMA); lactone polyester polyols such as poly-ε-caprolactone (PCL); polycarbonate polyols such as polyhexamethylene carbonate; and acrylic polyols.

  Although the number average molecular weight of the said high molecular weight polyol is not specifically limited, For example, 400 or more are preferable, More preferably, it is 1,000 or more. The upper limit of the number average molecular weight of the high molecular weight polyol is not particularly limited, but is preferably 10,000, more preferably 8,000. If the number average molecular weight of the high molecular weight polyol is within the above range, the adhesion of the obtained coating film to the golf ball body is improved. The number average molecular weight may be measured by gel permeation chromatography (GPC) using polystyrene as a standard substance, tetrahydrofuran as an eluent, and two TSK-GEL SUPER H2500 (manufactured by Tosoh Corporation) as a column.

  In a preferred embodiment of the present invention, (B) the polyol component contains, in addition to polyrotaxane, at least one selected from the group consisting of polyether polyol, polyester polyol, polycaprolactone polyol, polycarbonate polyol, and acrylic polyol .

  In a more preferred embodiment of the present invention, the (B) polyol component contains polycaprolactone polyol (poly-ε-caprolactone (PCL)) in addition to polyrotaxane. Specific examples of the polycaprolactone polyol include, for example, Placel 308 and Placel 312 manufactured by Daicel Chemical Industries, Ltd., and Capa 4101 and 4801 manufactured by Perstorp.

(B) Embodiment containing only polyrotaxane as the polyol component; Embodiment containing polyrotaxane and high molecular weight polyol; Embodiment containing polyrotaxane and low molecular weight polyol; Polyrotaxane, low molecular weight polyol, and high molecular weight polyol The aspect etc. which contain are mentioned. Moreover, low molecular weight polyols and high molecular weight polyols may be used in combination of two or more.

  When the polyol component (B) contains a polyrotaxane and another polyol, the content of the polyrotaxane in the polyol component (B) is preferably 10% by mass or more, more preferably 15% by mass or more, and 20% by mass or more Is more preferable, and 50% by mass or more is particularly preferable. Moreover, 100 mass% or less is preferable, as for the content rate of a polyrotaxane, 90 mass% or less is more preferable, and 80 mass% or less is more preferable. If the content of the polyrotaxane is within the above range, the flexibility which is the property of the polyrotaxane is sufficiently exhibited.

  The polyurethane used in the present invention may have a polyamine as a component in addition to the (A) polyisocyanate component and the (B) polyol component. The polyamine is not particularly limited as long as it has at least two or more amino groups. Examples of the polyamine include aliphatic polyamines, alicyclic polyamines, and aromatic polyamines. Examples of the aliphatic polyamines include ethylene diamine, propylene diamine, butylene diamine and hexamethylene diamine. Examples of alicyclic polyamines include isophorone diamine and piperazine.

  The aromatic polyamine is not particularly limited as long as at least two or more amino groups are directly or indirectly bonded to an aromatic ring. Here, "indirectly bonded" means that the amino group is bonded to the aromatic ring, for example, via a lower alkylene group. The aromatic polyamine may be, for example, a monocyclic aromatic polyamine in which two or more amino groups are bonded to one aromatic ring, or an amino in which at least one amino group is bonded to one aromatic ring It may be a polycyclic aromatic polyamine containing two or more phenyl groups.

  As the monocyclic aromatic polyamine, for example, a type in which an amino group such as phenylenediamine, toluenediamine, diethyltoluenediamine, dimethylthiotoluenediamine or the like is directly bonded to an aromatic ring; an amino group such as xylylenediamine The type etc. which are bonded to an aromatic ring via a lower alkylene group are mentioned. The polycyclic aromatic polyamine may be poly (aminobenzene) in which at least two aminophenyl groups are directly bonded, or at least two aminophenyl groups intervene in lower alkylene groups and alkylene oxide groups. May be combined. Among these, diaminodiphenyl alkanes in which two aminophenyl groups are linked via a lower alkylene group are preferable, and 4,4'-diaminodiphenylmethane and its derivatives are particularly preferable.

  The configuration mode of the polyurethane used in the present invention is not particularly limited, but, for example, an embodiment composed of a polyisocyanate component and a polyrotaxane, a polyisocyanate component, a polyrotaxane and a high molecular weight polyol component And the aspect which is comprised with a polyisocyanate component, a polyrotaxane, a high molecular weight polyol component, and a low molecular weight polyol component.

  The content of the polyurethane is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 55% by mass or more, and 100% by mass or less in the resin component of the coating film. Is preferably, 95% by mass or less is more preferable, and 90% by mass or less is more preferable.

  The resin component of the coating film of the present invention may further contain a fluorocarbon resin, an acrylic resin, or a vinyl chloride / vinyl acetate copolymer and / or a modified product thereof. Among these, the resin component of the coating film of the present invention preferably contains a vinyl chloride / vinyl acetate copolymer and / or a modified product thereof. By containing the vinyl chloride / vinyl acetate copolymer and / or the modified product thereof, it is possible to adjust the tackiness while maintaining the scuff resistance, and to have a favorable tackiness. Examples of the modification include a method of copolymerizing vinyl chloride and a monomer copolymerizable with vinyl acetate (eg, vinyl alcohol, hydroxyalkyl acrylate, etc.), partially saponifying a vinyl chloride / vinyl acetate copolymer or By complete saponification, the method etc. which introduce a hydroxyl group can be mentioned.

  In the vinyl chloride / vinyl acetate copolymer and / or its modified product, the content of the vinyl chloride component is preferably 1% by mass or more, more preferably 20% by mass or more, and preferably 99% by mass or less, and 95% by mass or less Is more preferred. In the present invention, it is preferable to use a hydroxyl group-modified vinyl chloride / vinyl acetate copolymer as the vinyl chloride / vinyl acetate copolymer and / or the modified product thereof. Specific examples of the vinyl chloride / vinyl acetate copolymer and / or the modified product thereof include Solvain (registered trademark) A, Solvain AL, Solvain TA2, Solvain TA3 and the like manufactured by Nisshin Chemical Industry Co., Ltd.

  Moreover, 4 mass% or more is preferable among the resin components which comprise a coating film, and, as for the content rate of the said vinyl chloride / vinyl acetate copolymer and / or its modified substance, 8 mass% or more is more preferable, and 50 mass% or less Is preferable, and 45 mass% or less is more preferable.

[Coating composition]
The coating film of the golf ball of the present invention comprises a curable coating composition comprising: (B) a main component comprising a polyol composition containing a polyrotaxane; and (A) a curing agent comprising a polyisocyanate composition containing a polyisocyanate component. Preferably, it is formed of In the present invention, in order to distinguish the polyol composition containing polyrotaxane from the polyisocyanate composition containing polyisocyanate, for convenience, they are respectively referred to as a main agent and a curing agent. However, the main agent and the curing agent may be referred to as agent A and agent B, respectively. In addition, it is also optional to refer to a polyol composition containing (B) polyrotaxane as a curing agent, and to refer to a polyisocyanate composition containing (A) a polyisocyanate component as a main agent.

  In the curable coating composition used in the present invention, the main agent preferably contains a compound having reactivity with the isocyanate group used as the curing agent. Specifically, the main agent preferably contains a polyol component containing (B) polyrotaxane. The main ingredient of the curable coating composition preferably contains a vinyl chloride / vinyl acetate copolymer and / or a modified product thereof.

  In the curing reaction of the curable coating composition, the molar ratio (NCO group / OH) of the isocyanate group (NCO group) of the polyisocyanate component (A) to the hydroxyl group (OH group) possessed by the polyol component containing (B) polyrotaxane 0.95 or more are preferable, 1.05 or more are more preferable, and 1.10 or more are further more preferable. When the molar ratio (NCO group / OH group) is less than 0.95, the curing reaction becomes insufficient. In addition, when the molar ratio (NCO group / OH group) is too large, the amount of isocyanate groups becomes excessive, the resulting coating film becomes hard and brittle, and the appearance also deteriorates. Therefore, the molar ratio (NCO group / OH group) is preferably 2.0 or less, more preferably 1.8 or less, and still more preferably 1.5 or less. The reason why the appearance of the resulting coating film is deteriorated when the amount of isocyanate groups in the paint is excessive is that, when the amount of isocyanate groups is excessive, the reaction between the water in the air and the isocyanate groups increases and a large amount of carbon dioxide gas is produced. It is thought to occur in the In addition, when considering the NCO / OH molar ratio of the curing reaction, the hydroxyl groups of the main agent include hydroxyl groups of polyrotaxane and polyol, but modified products of vinyl chloride / vinyl acetate copolymer and modified silicones described later It does not contain the hydroxyl group contained in.

  Known catalysts can be used for the curing reaction. Examples of the catalyst include monoamines such as triethylamine and N, N-dimethylcyclohexylamine; N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N ′ ′, N ′ ′- Polyamines such as pentamethyldiethylene triamine; Cyclic diamines such as 1,8-diazabicyclo [5.4.0] -7-undecene (DBU) and triethylenediamine; tin-based catalysts such as dibutyltin dilaurate and dibutyltin diacetate Can be mentioned. These catalysts may be used alone or in combination of two or more. Among these, tin-based catalysts such as dibutyltin dilaurate and dibutyltin diacetate are preferable, and dibutyltin dilaurate is particularly preferably used.

[solvent]
The curable coating composition is preferably a solvent-based coating composition using an organic solvent as a dispersion medium. This is because it is preferable to use an organic solvent because polyrotaxane is poorly soluble in water. Preferred solvents include toluene, isopropyl alcohol, xylene, methyl ethyl ketone, methyl ethyl isobutyl ketone, ethylene glycol monomethyl ether, ethyl benzene, propylene glycol monomethyl ether, isobutyl alcohol, ethyl acetate and the like. The solvent may be added to any of the main agent and the curing agent, but it is preferable to add it to each of the main agent and the curing agent from the viewpoint of uniform curing reaction.

  The curable coating composition preferably further contains a modified silicone. By containing modified silicone as a leveling agent, the unevenness of the coated surface is reduced, and a smooth coated surface is formed on the golf ball surface. As the modified silicone, one having an organic group introduced to the side chain or end of a polysiloxane skeleton, a polysiloxane block copolymer obtained by copolymerizing a polyether block and / or a polycaprolactone block with a polysiloxane block, or The thing which introduce | transduced the organic group into the side chain or the terminal of the polysiloxane block copolymer etc. can be mentioned. The polysiloxane skeleton or the polysiloxane block is preferably linear, and examples thereof include dimethylpolysiloxane, methylphenylpolysiloxane and methylhydrogenpolysiloxane. As said organic group, an amino group, an epoxy group, a mercapto group, carbinol group etc. can be mentioned, for example. In the present invention, it is preferable to use a polydimethylsiloxane-polycaprolactone block copolymer as the modified silicone oil, and it is more preferable to use a terminal carbinol-modified polydimethylsiloxane-polycaprolactone block copolymer. It is because it is excellent in compatibility with caprolactone modified polyrotaxane and polycaprolactone polyol. Specific examples of the modified silicone used in the present invention include DBL-C31, DBE-224, DCE-7521 and the like manufactured by Gelest.

  The modified silicone remains in the coating formed from the coating composition. The content of the modified silicone in the coating film and the curable coating composition is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, with respect to 100 parts by mass of the resin component constituting the coating film. 10 parts by mass or less is preferable, and 5 parts by mass or less is more preferable.

  The curable coating composition may further contain, if necessary, a filler, an ultraviolet absorber, an antioxidant, a light stabilizer, a brightening agent, an antiblocking agent, a leveling agent, a slip agent, a viscosity modifier, etc. You may contain the additive which may be contained in the coating material for golf balls.

  Next, the method for applying the curable coating composition of the present invention will be described. The application method of the curable coating composition is not particularly limited, and a known method can be adopted, and examples thereof include spray coating and electrostatic coating.

  In the case of spray coating using an air gun, even if the main agent and the curing agent are supplied by the respective pumps and continuously mixed with a line mixer disposed just before the air gun, the resulting mixture is spray coated. Alternatively, the main agent and the curing agent may be separately spray coated using an air spray system equipped with a mixing ratio control mechanism. The coating may be applied by spraying at one time or may be repeated several times.

  The curable coating composition applied to the golf ball body can form a coated film, for example, by drying at a temperature of 30 ° C. to 70 ° C. for 1 hour to 24 hours.

  Although the film thickness of the coating film after drying is not particularly limited, 5 μm or more is preferable, 6 μm or more is more preferable, 10 μm or more is more preferable, and 15 μm or more is particularly preferable. If the film thickness is less than 5 μm, the coating film tends to be abraded away by continuous use. Also, by increasing the film thickness, the spin amount of the approach shot is increased. Moreover, 50 micrometers or less are preferable, as for the film thickness of a coating film, 45 micrometers or less are more preferable, and 40 micrometers or less are more preferable. If the film thickness is larger than 50 μm, the effect of the dimples may be reduced, and the flight performance of the golf ball may be reduced. The film thickness of the coating can be measured, for example, using a microscope (VHX-1000 manufactured by KEYENCE CORPORATION) on a cross section of a golf ball. In addition, when a coating material is overpainted several times, it is preferable that the thickness of the formed whole coating film is the said range.

  The coating film of the golf ball of the present invention may have a single layer structure or a multilayer structure, and preferably has a single layer structure.

[Golf ball body]
The golf ball of the present invention is not particularly limited as long as it is a golf ball having a golf ball body and a coating film covering the golf ball body. The structure of the golf ball body is not particularly limited, and may be a two-piece golf ball, a three-piece golf ball, a multi-piece golf ball of four or more golf balls, or a thread-wound golf ball. In any case, the present invention can be suitably applied.

  The golf ball body of the present invention preferably has a core and a cover that covers the core. There may be an intermediate layer between the core and the cover.

  FIG. 2 is a partially cutaway cross-sectional view of a golf ball 100 according to an embodiment of the present invention. The golf ball 100 has a spherical core 104, an intermediate layer 106 covering the spherical core 104, and a cover 112 covering the intermediate layer 106. A large number of dimples 114 are formed on the surface of the cover 112. Of the surface of the golf ball, portions other than the dimples 114 are lands 116. The golf ball has a paint layer and a mark layer on the outside of the cover, but these layers are not shown.

  In the present invention, the material hardness of the cover of the golf ball body is preferably 30 or more, more preferably 40 or more, still more preferably 50 or more, and particularly preferably 55 or more in Shore D hardness. The material hardness of the cover is preferably 90 or less, more preferably 80 or less, and still more preferably 70 or less. By properly adjusting the cover hardness, a golf ball having a good feel at impact and durability can be obtained. The material hardness of the cover is a slab hardness measured by molding the composition for the cover forming the cover into a sheet.

  In the present invention, the thickness of the cover of the golf ball is not particularly limited, but 4 mm or less is preferable, 2 mm or less is more preferable, and 1 mm or less is more preferable. By setting the diameter to 4 mm or less, the outer diameter of the core can be increased, so that the resilience performance can be improved. The lower limit of the thickness of the cover is not particularly limited, but is preferably 0.3 mm, more preferably 0.4 mm, and still more preferably 0.5 mm. If it is less than 0.3 mm, molding of the cover may be difficult.

  The cover material constituting the cover of the golf ball of the present invention is not particularly limited, and examples thereof include ionomer resins, polyester resins, urethane resins such as thermoplastic urethane resins or two-component curable urethane resins, and polyamide resins Various resins, thermoplastic polyamide elastomer commercially available under the trade name "Pebax (registered trademark) (for example," Pebax 2533 ")" from Arkema Co., Ltd., trade name "Hightre (registered trademark) from Toray Dupont Co., Ltd. (For example, “Hytrel 3548”, “Hytrel 4047”), a thermoplastic polyester elastomer commercially available from BASF Japan Ltd. under the trade name “Elastol (registered trademark) (for example,“ Elastol XNY 97A ”)” Commercially available thermoplastic polyurethane elastomer Tomah, and the like trade name "Rabalon ®" thermoplastic polyester elastomer commercially available thermoplastic styrene elastomer, or trade names of commercially available "Primalloy" in the Mitsubishi Chemical Corporation. In the present invention, an ionomer resin is preferably used as a cover material. The cover materials may be used alone or in combination of two or more.

  The cover includes, in addition to the resin components described above, pigment components such as white pigment (for example, titanium oxide), blue pigment, red pigment, etc., weight regulators such as calcium carbonate and barium sulfate, dispersants, antiaging agents, and ultraviolet light absorption An agent, a light stabilizer, a fluorescent material, a fluorescent whitening agent, etc. may be contained in the range which does not impair the performance of a cover.

  The mode of molding the cover using the cover composition is not particularly limited, but the mode of injection molding the cover composition directly onto the core, or molding a hollow shell-like shell from the cover composition, the core And (b) preferably forming a hollow shell-like half shell from the cover composition and coating the core with two half shells to perform compression molding. Can. The golf ball main body with the cover molded is preferably taken out of the mold and subjected to surface treatment such as deburring, washing, sand blasting and the like as required. Also, if desired, marks can be formed.

  The total number of dimples formed on the cover is preferably 200 or more and 500 or less. If the total number of dimples is less than 200, it is difficult to obtain dimple effects. In addition, when the total number of dimples exceeds 500, the size of each dimple becomes small, and it is difficult to obtain the effect of dimples. The shape (planar shape) of the dimple to be formed is not particularly limited, and circular shape; polygonal shape such as substantially triangular shape, substantially rectangular shape, substantially pentagonal shape, substantially hexagonal shape, etc .; They may be used in combination of two or more.

  The diameter of the golf ball is preferably 40 mm to 45 mm. The diameter is preferably 42.67 mm or more from the viewpoint that the American Golf Association (USGA) standard is satisfied. In light of air resistance, the diameter is preferably equal to or less than 44 mm, and more preferably equal to or less than 42.80 mm. The mass of the golf ball is preferably 40 g or more and 50 g or less. From the viewpoint of obtaining a large inertia, the mass is preferably 44 g or more, more preferably 45.00 g or more. The mass is preferably 45.93 g or less from the viewpoint that the USGA standard is satisfied.

  When the golf ball of the present invention has a diameter of 40 mm to 45 mm, the amount of compressive deformation (amount of compression in the compression direction) when a final load of 1275 N is applied from the state of applying an initial load of 98 N is greater than 3.0 mm. Preferably, it is more preferably 3.2 mm or more, still more preferably 3.5 mm or more, preferably 5.5 mm or less, more preferably 4.8 mm or less, still more preferably 4.5 mm It is below. The golf ball having the amount of compressive deformation of more than 3.0 mm has a good feel at impact. On the other hand, by setting the amount of compressive deformation to 5.5 mm or less, the resilience becomes high.

  Next, thread wound golf balls, cores used for two-piece golf balls and multi-piece golf balls, and one-piece golf ball bodies will be described.

  For the core and the one-piece golf ball main body, known rubber compositions (hereinafter sometimes simply referred to as "core rubber compositions") can be used. For example, base rubber, co-crosslinking agent and crosslinking initiator Can be heat-pressed and molded.

  As the base rubber, it is particularly preferable to use a high cis polybutadiene having a cis bond content of 40% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, which is advantageous for repulsion. As the co-crosslinking agent, an α, β-unsaturated carboxylic acid having 3 to 8 carbon atoms or a metal salt thereof is preferable, and a metal salt of acrylic acid or a metal salt of methacrylic acid is more preferable. The metal of the metal salt is preferably zinc, magnesium, calcium, aluminum or sodium, more preferably zinc. The use amount of the co-crosslinking agent is preferably 20 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the base rubber. As a crosslinking initiator, an organic peroxide is preferably used. Specifically, dicumyl peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (t-butylperoxy) Organic peroxides such as hexane and di-t-butyl peroxide can be mentioned, and among these, dicumyl peroxide is preferably used. The compounding amount of the crosslinking initiator is preferably 0.2 parts by mass or more, more preferably 0.3 parts by mass or more, and preferably 3 parts by mass or less, with respect to 100 parts by mass of the base rubber. It is 2 parts by mass or less. The core rubber composition may further contain an organic sulfur compound. As the organic sulfur compound, diphenyl disulfides, thiophenols and thionaphthols can be suitably used. The amount of the organic sulfur compound is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and preferably 5.0 parts by mass or less, per 100 parts by mass of the base rubber. Preferably it is 3.0 mass parts or less. The core rubber composition may further contain a carboxylic acid and / or a salt thereof. As a carboxylic acid and / or its salt, a C1-C30 carboxylic acid and / or its salt are preferable. The compounding quantity of carboxylic acid and / or its salt is 1 mass part or more and 40 mass parts or less with respect to 100 mass parts of base rubber.

  In addition to a base rubber, a co-crosslinking agent, a crosslinking initiator, and an organic sulfur compound, the core rubber composition may further contain, as appropriate, a weight regulator such as zinc oxide or barium sulfate, an antioxidant, a color powder, etc. It can be blended. The heat press molding conditions for the core rubber composition may be appropriately set according to the rubber composition, but usually, heating is performed at 130 ° C. to 200 ° C. for 10 minutes to 60 minutes, or 20 ° C. at 130 ° C. to 150 ° C. After heating for 40 minutes, it is preferable to perform two-step heating at 160 ° C. to 180 ° C. for 5 minutes to 15 minutes.

[Golf ball]
When the golf ball of the present invention is a three-piece, four-piece golf ball or more multi-piece golf ball, materials used for the intermediate layer provided between the core and the outermost cover include, for example, polyurethane resin, ionomer Thermoplastic resins such as resins, polyamide resins and polyethylene; thermoplastic elastomers such as styrene elastomers, polyolefin elastomers, polyurethane elastomers and polyester elastomers; and cured products of rubber compositions. Here, as the ionomer resin, for example, one in which at least a part of carboxyl groups in a copolymer of ethylene and an α, β-unsaturated carboxylic acid is neutralized with a metal ion, or ethylene and an α, β-unsubstituted one. What neutralized at least one part of the carboxyl group in the terpolymer of the saturated carboxylic acid and the (alpha), (beta) unsaturated carboxylic ester with a metal ion is mentioned. The intermediate layer may further contain a weight regulator such as barium sulfate or tungsten, an antiaging agent, a pigment, and the like. The intermediate layer may be referred to as an inner cover layer or an outer layer core, depending on the configuration of the golf ball.

  EXAMPLES Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited by the following examples, and all changes and embodiments within the scope of the present invention are within the scope of the present invention. It is included in the range.

[Evaluation method]

(1) Material (slab) hardness (Shore D hardness)
A sheet of about 2 mm in thickness was prepared by injection molding using the cover composition, and was stored at 23 ° C. for 2 weeks. The hardness was measured using an automatic hardness tester (Digitest II, manufactured by H. Burley's Co., Ltd.) in a state where three or more sheets of this sheet were stacked so as not to be affected by a measurement substrate or the like. As a detector, "Shore D" or "Shore A" was used.

(2) Measurement of Dynamic Viscoelasticity The storage elastic modulus E ′ (Pa), loss elastic modulus E ′ ′ (Pa) and loss tangent (tan δ) of the coating film were measured under the following conditions.
Device: Dynamic Viscoelasticity Measuring Device Rheogel-E4000 manufactured by UBM.
Measurement sample: A paint containing a main agent and a curing agent was dried and cured at 40 ° C. for 4 hours to prepare a coated film having a thickness of 0.11 to 0.14 mm. A sample piece was cut out of this coated film so as to have a width of 4 mm and a distance between clamps of 20 mm.
Measurement mode: Tension Measurement temperature: -100 ° C to 150 ° C
Heating rate: 4 ° C / min Measurement data acquisition interval: 4 ° C
Excitation frequency: 10 Hz
Measurement distortion: 0.1%

(3) Indentation Depth of Coating Film In measurement of indentation depth, a golf ball is cut to obtain a hemisphere. In the hemisphere, a cross section passing through the center of the golf ball is exposed. This cross section includes the cross section of the coating. The cryomicrotome makes the cross section of this hemisphere horizontal. The indenter of the nano indenter is applied to the cross section of the coating and pressed in a direction perpendicular to the cross section. By pressing, the indenter advances. The load and travel distance of the indenter are measured. The conditions at the time of measurement are as follows.
・ Nano indenter: "ENT-2100" of Elionix Inc.
Temperature: 30 ° C
· Indenter: Verkovich indenter (65.03 ° As (h) = 26.43 h2)
Division number: 500 steps Step interval: 20 msec (100 mgf)
The load on the indenter is gradually increased until it reaches 50 mgf. The advancing distance (nm) of the indenter when the load is 30 mgf is measured as the indentation depth.

(4) 10% modulus of the coating (kgf / cm ² )
The 10% modulus of the coating was measured according to JIS K7161 (2014). Specifically, a paint containing a main agent (polyol composition) and a curing agent (polyisocyanate composition) was dried and cured at 40 ° C. for 4 hours to prepare a coating (thickness 0.05 mm). The coated film was punched into a test piece type 2 (width 10 mm of parallel part, distance between marked lines 50 mm) defined in JIS K7127 (1999) to prepare a test piece. The tensile test was performed on this test piece using a precision universal tester (Autograph (registered trademark) manufactured by Shimadzu Corporation). The test conditions were a distance between clamps of 100 mm, a tensile speed of 50 mm / min, and a test temperature of 23 ° C.

(5) Coating film thickness (μm)
The golf ball was cut into a hemispherical shape, and the coating film cross section on the hemisphere was observed using a microscope (VHX-1000 manufactured by Keyence Corporation) to determine the film thickness of the coating film.

(6) Feeling at Shot The actual hitting test was conducted by 10 amateur golfers (experts) using a sand wedge (CG15 Forge Dow Edge (58 °) manufactured by Cleveland Golf Co., Ltd.). Based on the number of people who answered that they felt good (feeling good on the face, good on the hit, good on the spin, good on the stick, etc.), Evaluated.
:: 8 or more ○: 5 to 7 △: 3 to 4 ×: 2 or less

(7) Contamination resistance The golf ball was taken out by immersing it in an iodine tincture water prepared by diluting an iodine tincture (an ethanol solution containing 6% by mass of iodine and 4% by mass of potassium iodide) 40 times for 30 seconds. After wiping off the excess iodine tincture water adhering to the surface of the golf ball, the color tone (L, a, b) of the golf ball before and after the immersion is measured using a color difference meter (CM3500D manufactured by Konica Minolta Co., Ltd.). (ΔE) was calculated by the following equation. In addition, it means that the degree of discoloration is so large that the value of color difference ((DELTA) E) is large.
ΔE = [(ΔL) ² + (Δa) ² + (Δb) ² ] ^1/2
Evaluation criteria ◎: ΔE is 15 or less ○: ΔE is more than 15 and 20 or less ×: ΔE is more than 20

(8) Spin amount of approach shot from rough The wet paper with a slit was attached to the surface of the club face of the sand wedge, and the controllability of the approach shot from rough was evaluated. A golf ball with a high spin rate by this test method is excellent in controllability of approach shots from the rough. Specifically, a sand wedge (trade name “CG15 Ford Wedge” manufactured by Cleveland Golf, loft angle: 52 °) was attached to a swing machine of a golf laboratory. As shown in FIG. 3, Spontara Maintenance Cloth manufactured by DuPont Co., Ltd. Slits are provided at 5 mm intervals on a thick (size: 56 mm × 56 mm) and immersed in water so that the slits become perpendicular to the grooves of the club face. , I put wet paper on the surface of the club face. In this state, the golf ball was hit at a head speed of 16 m / s, and the amount of spin (rpm) was measured. The measurement of the spin amount was performed by taking continuous pictures of the hit golf ball. For each golf ball, an average value of data obtained by measuring ten times was calculated.

(9) Compressive deformation (mm)
The amount of deformation in the compression direction (the amount of shrinkage of the core or the golf ball in the compression direction) from when the initial load 98N was loaded to the core or golf ball to when the final load 1275N was loaded was measured.

(10) Feeling at shot of driver's shot An actual golf player (advanced person) 10 performed an actual hit test using a driver (manufactured by Dunlop Sports, Srikson Z-765). Feeling good (based on the number of people who answered that they feel soft, feel good right, feel good coming, feel good to hit the ball, etc.) , Was evaluated as follows.
:: 8 or more ○: 5 to 7 △: 3 to 4 ×: 2 or less

[Preparation of Two-Piece Golf Ball]
(1) Preparation of Spherical Core The core rubber composition having the composition shown in Table 1 is kneaded, and heated and pressed in the upper and lower molds having hemispherical cavities at 170 ° C. for 20 minutes to obtain a spherical core having a diameter of 39.7 mm. Obtained.

ポリブタジエンゴム：ＪＳＲ（株）製、「ＢＲ７３０（ハイシスポリブタジエン）」
アクリル酸亜鉛：日本蒸留工業社製ＺＮ−ＤＡ９０Ｓ（１０％ステアリン酸亜鉛コーティング）
酸化亜鉛：東邦亜鉛製、「銀嶺Ｒ」
硫酸バリウム：堺化学社製、「硫酸バリウムＢＤ」
ジフェニルジスルフィド：住友精化製
ジクミルパーオキサイド：日本油脂製、「パークミル（登録商標）Ｄ」

Polybutadiene rubber: "BR730 (High cis polybutadiene)" manufactured by JSR Corporation
Zinc acrylate: ZN-DA90S (10% zinc stearate coating) manufactured by Nippon Distillery Co., Ltd.
Zinc oxide: Toho Zinc, "Ginko R"
Barium sulfate: "Barium sulfate BD" manufactured by Sakai Chemical Co., Ltd.
Diphenyl Disulfide: Dicumyl peroxide manufactured by Sumitomo Seika Chemical Co., Ltd .: Nippon Oil and Fats Co., Ltd., "Park Mill (registered trademark) D"

(2) Preparation of composition for cover The material of the composition shown in Table 2 was mixed by a twin-screw kneader-type extruder to prepare a composition for cover in the form of pellet. The extrusion conditions were a screw diameter of 45 mm, a screw rotation speed of 200 rpm, and a screw L / D = 35, and the compound was heated to 200 to 260 ° C. at the position of the die of the extruder.

The raw materials used in Table 2 are as follows.
HIMIRAN 1605: made by Mitsui DuPont Polychemicals, sodium ion neutralized ethylene-methacrylic acid copolymer ionomer resin HIMIRAN AM 7329: made by Mitsui DuPont Polychemicals, zinc ion neutralized ethylene-methacrylic acid copolymer ionomer resin HIMIRAN AM 7327: Mitsui DuPont Polychemical Co., Ltd., zinc ion neutralized ethylene-methacrylic acid-butyl acrylate copolymer ionomer resin

(3) Preparation of Cover A cover was formed by direct injection molding of the composition for a cover obtained above on the spherical core obtained as mentioned above. The upper and lower molds have hemispherical cavities and hold pins which can move back and forth to support the spherical core. At the time of cover molding, the above-mentioned hold pin is pushed out, the spherical core is put in and held, and the composition for cover heated at 260 ° C. is injected in 0.3 seconds into a mold clamped at a pressure of 80 tons and cooled for 30 seconds. Then, a cover (thickness 1.45 mm) was formed.

(6) Preparation of paint The materials shown in Table 3 were blended, and paint composition No. 1 was prepared. 1 to No. 8 was prepared. The surface of the golf ball main body obtained above is sandblasted and marked, and then a paint is applied using a spray gun, and the paint is dried in an oven at 40 ° C. for 24 hours to have a diameter of 42.7 mm and a weight of 45. 3 g of golf ball was obtained. The thickness of the coating was 18 μm. The coating was performed while placing the golf ball main body on the rotating body shown in FIG. 4, rotating the rotating body at 300 rpm, moving an air gun away from the golf ball main body by a distance (7 cm) and moving it vertically. . The interval for each overpainting was 1.0 second. The spraying conditions of the air gun are: spraying air pressure: 0.15 MPa, pumping tank air pressure: 0.10 MPa, one coating time; 1 second, atmospheric temperature: 20 ° C. to 27 ° C., atmospheric humidity: 65% or less It was painted. The results evaluated for the spin performance of the obtained golf ball are also shown in Table 4. In addition, the coating film was produced from each coating material, and the result of having measured the dynamic viscoelasticity was shown in FIGS.

The raw materials used in Table 3 are as follows.
Main ingredient polyrotaxane: Advanced Soft Materials Co., Ltd., “Cerum (registered trademark) super polymer SH3400P (At least a part of hydroxyl group of cyclodextrin is modified by caprolactone chain via -O-C ₃ H ₆ -O- group Polyrotaxane, linear molecule: polyethylene glycol, blocking group: adamantane group, molecular weight of linear molecule: 35,000, hydroxyl value: 72 mg KOH / g, overall molecular weight: weight average molecular weight 700,000) "
Polycaprolactone polyol: Daicel Placel 308
Modified product of vinyl chloride / vinyl acetate copolymer: Solvaine AL (hydroxyl modified vinyl chloride / vinyl acetate copolymer) manufactured by Nisshin Chemical Industry Co., Ltd.
Modified silicone: manufactured by Gelest, DBL-C31
Solvent: mixed solvent of xylene / methyl ethyl ketone = 70/30 (mass ratio) Porin # 950: manufactured by Shinto Paint Co., Ltd., hydroxyl value 128 mg KOH / g, polyol component (trimethylolpropane, polyoxytetramethylene glycol), and polyisocyanate component Urethane polyol consisting of (isophorone diisocyanate)

Curing agent Isocyanurate modified product of hexamethylene diisocyanate: Duranate TKA-100 manufactured by Asahi Kasei Chemicals Corporation (NCO content: 21.7%)
Buret modified product of hexamethylene diisocyanate: Duranate 21S-75E (NCO content: 15.5%) manufactured by Asahi Kasei Chemicals Corporation
Isocyanurate modified isophorone diisocyanate: Degussa VESTANAT T 1890 (NCO content: 12.0%)
Solvent: methyl ethyl ketone

From the results of Table 3, it is a golf ball having a golf ball body and a coating film covering the golf ball body, wherein the 10% modulus of the coating film is 75 kgf / cm ² or less, and The storage elastic modulus (E ' ₁₅₀ ) of 150 ° C. obtained by measuring the dynamic viscoelasticity is 1.0 × 10 ⁷ Pa or more, and provided on the surface of the golf ball body, using a nano indenter. The indentation depth of the coating film measured is 1250 nm or more, the diameter of the golf ball is 40 mm to 45 mm, and compression from the state where the initial load 98 N is applied to the golf ball to the time when the final load 1275 N is applied. The golf ball of the present invention having a deformation amount of more than 3.0 mm has a good feel at impact on driver shots, a high spin rate on approach shots from the rough, and It can be seen that the trawl performance is excellent. In addition, the golf ball of the present invention is excellent in stain resistance and feel at impact.

  The present invention is suitably applicable to a painted golf ball.

1: contact force testing machine 2: golf ball 3: strike surface 4: collision plate 5: launch device 6: controller 7: strobe device 8: high speed camera device 9: strobe power supply 10 : Camera power supply, Fn: Vertical force in the direction perpendicular to the striking surface, Ft: Shearing force in the direction parallel to the striking surface, 20: Golf ball, 21: Rotating body, 23a to 23c: Prong, 25: Air gun, 100: Golf ball 104: spherical core 106: intermediate layer 112: cover 114: dimple 116: land 200: polyrotaxane 212: cyclodextrin 214: linear molecule 216: blocking group 218: caprolactone chain

Claims (14)

A golf ball having a golf ball body and a coating film for coating the golf ball body, wherein the 10% modulus of the coating film is 75 kgf / cm ² or less, and the dynamic viscoelasticity of the coating film is measured. When the storage elastic modulus (E ' ₁₅₀ ) obtained at 150 ° C. is 1.0 × 10 ⁷ Pa or more and provided on the surface of the golf ball body, the indentation of the coating film measured using a nano indenter The depth is 1250 nm or more, the diameter of the golf ball is 40 mm to 45 mm, and the amount of compressive deformation is 3.0 mm from when the initial load 98 N is applied to the golf ball to when the final load 1275 N is applied. A golf ball characterized by being super.   2. The golf ball according to claim 1, wherein the peak temperature of loss tangent tan δ obtained by measuring the dynamic viscoelasticity of the coating film is 60 ° C. or less. The golf ball according to claim 1, wherein a storage elastic modulus (E ′) at 120 ° C. of the coating film is 1.0 × 10 ⁷ Pa or more. The 10% modulus of the coating, the golf ball according to any one of claims 1 to 3 is 2 kgf / cm ² or more.   The said coating film contains the polyurethane which has (A) polyisocyanate component and the polyol component which contains (B) polyrotaxane as a resin component as a structural component. The golf ball of description.   The said polyurethane is obtained by making it react so that the molar ratio of the isocyanate group (NCO) of the (A) polyisocyanate component to the hydroxyl group (OH) of the (B) polyol component may be 0.95 or more and 2.0 or less. The golf ball according to claim 5, which is a golf ball. The polyrotaxane has a cyclodextrin, a linear molecule that skewers the cyclic structure of the cyclodextrin, and a blocking group which is disposed at both ends of the linear molecule and prevents the detachment of the cyclodextrin. and, at least a portion of said cyclodextrin hydroxyl groups, via the -O-C 3 _H 6 _-O- group, a golf ball according to claim 5 or 6 is a polyrotaxane which is modified by caprolactone chain.   The golf ball according to claim 7, wherein in the polyrotaxane, the linear molecule is polyethylene glycol, and the blocking group is an adamantane group.   (B) The polyol component further contains at least one selected from the group consisting of polyether polyol, polyester polyol, polycaprolactone polyol, polycarbonate polyol, and acrylic polyol. The golf ball of description.   The golf ball according to any one of claims 5 to 9, wherein the content of the polyrotaxane in the polyol component (B) is 10% by mass to 100% by mass.   The golf ball according to any one of claims 5 to 10, wherein the coating film further contains a vinyl chloride / vinyl acetate copolymer and / or a modified product thereof as a resin component.   The golf ball according to any one of claims 5 to 11, wherein the coating film further contains a modified silicone.   The golf ball according to claim 12, wherein the modified silicone is contained in an amount of 0.01 parts by mass to 10 parts by mass with respect to 100 parts by mass of the resin component of the coating film.   The golf ball according to any one of claims 5 to 13, wherein the polyisocyanate component (A) contains an isocyanurate modified product of hexamethylene diisocyanate and an isocyanurate body of isophorone diisocyanate.

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