Bridgestone Sports Co., Ltd.

Hirotaka Shinohara

Takashi Ohira

Hiroshi Higuchi

Katsunori Sato

Daisuke Arai

Yuichiro Ozawa

Takuichi Shimizu

Motoki Furuyama

Tasuku Takita

Akira Kimura

Kae Iizuka

Atsushi Namba

Masanobu Kuwahara

Takeharu Fujie

A golf ball according to the present invention includes a core, a cover located outside the core and having a plurality of dimples, and a coating layer located outside the cover and containing a delusterant, the surface of the coating layer having an average roughness Ra of at least 0.35. The surface of the golf ball has a static friction coefficient of at least 0.20. A method for producing a golf ball according to the present invention includes forming a coating layer on the surface of a cover having a plurality of dimples by using a coating material composition including a polyurethane coating material, a delusterant, and a solvent having a boiling point of at least 130° C.

Golf ball including delusterant and method for producing the same

Provided are a golf ball which has a surface that sparkles when exposed to ultraviolet rays even if a naturally derived substance is used as a fluorescent material, and it is environmentally and human friendly, and a resin composition for a cover or a topcoat therefor. A resin composition for a cover or a topcoat of a golf ball of the present invention includes: a resin for a cover or a topcoat; and a plant-derived or alga-derived extract which emits light using an absorbed light as an energy source, as a fluorescent material. In the golf ball of the present invention, the cover or the topcoat is formed by using such a resin composition.

Golf ball and resin composition for cover or topcoat therefor

A golf ball composed of a core and a cover has a spin rate and a launch angle on approach shots at a head speed (HS) of 20 m/s or 10 m/s that satisfy formulas (1) and (2) below:Spin/Spin≥0.70  (1)<1.20  (2).Here, Spin D is the spin rate (rpm) under dry conditions, Spin W is the spin rate (rpm) under wet conditions, Ang W is the launch angle (°) under wet conditions and Ang D is the launch angle (°) under dry conditions. The golf ball suppresses a decrease in the spin rate on approach shots in rainy weather and thus has an improved controllability, making it especially useful to professional golfers and skilled amateurs who desire a high spin performance around the green.

Golf ball

A method for producing a golf ball of the present invention includes the steps of: forming a first coating film on a surface of a covering having a plurality of dimples; and forming a second coating film on a surface of the first coating film. The second coating film is formed of a second coating material composition containing a polyurethane coating material and a solvent having a boiling point of 80&#xb0; C. or less. An elastic recovery rate of the second coating film is 50% or more. In the golf ball of the present invention obtained by the method, an edge ratio which is a ratio of a film thickness of the second coating film in an edge portion of the dimple to a film thickness of the second coating film in a central portion of the dimple is 50% or more.

Golf ball and method for producing the same

Provided are a golf ball and a resin composition for a cover or topcoat thereof which can suppress the yellowing of the golf ball caused by ultraviolet rays even if a naturally derived substance is used as an ultraviolet absorber, and they are environmentally and human friendly. A resin composition for a cover or topcoat of a golf ball of the present invention contains: a resin for a cover or topcoat; and a plant-derived extract which absorbs ultraviolet rays. The resin composition has a color difference &#x394;E of 10.0 or less in a Lab color system between before and after a color tone change test, the color tone change test being carried out by irradiating a film formed from the resin composition with a xenon lamp. In the golf ball of the present invention, the cover or the topcoat is formed by using the resin composition.

Golf ball and resin composition for cover or topcoat thereof

A golf ball having a cover with a plurality of dimples on the surface thereof is provided with a coat of mutually differing properties on dimple areas of the surface and on land areas between the dimples. The land areas are formed with a coat having a high coefficient of friction and the dimple areas have a surface energy of not more than 32 dynes, enabling a lower spin rate to be achieved and thus increasing the distance traveled by the ball, particularly when struck with a middle iron, and also help impart a high spin rate and a good controllability on approach shots.

A golf ball of the present disclosure includes an inner ball and a cover layer that covers the outer surface of the inner ball and includes an outer surface with dimples. The inner ball includes an inner layer, which includes an outer surface with a recess, and an inner film that covers only the surface of the recess on the outer surface of the inner layer. The inner layer and the inner film are different colors from each other, and the cover layer is transparent or semi-transparent. Peeling of the film can be suppressed in the golf ball.

To provide a golf ball that can prevent a decrease in carry distance of a driver shot when it rains and also, can exert excellent spinning performance upon an approach shot. The golf ball of the present invention includes a core, a cover that is provided on an outer side of the core and is provided with dimples, and an outermost layer that is formed on an outer side of the cover and made of a material having a contact angle of 90&#xb0; or more. The golf ball has a dynamic friction coefficient of 0.52 or more. The material constituting the outermost layer comprises a urethane coating that contains a water repellent additive, and the water repellent additive includes a fluorinated surfactant, silicone-modified acrylate or hydrophobic silica. The urethane coating comprises a polyisocyanate as a curing agent, and the polyisocyanate includes both an adduct form and an isocyanurate form of hexamethylene diisocyanate, and a mixing ratio (isocyanurate form/adduct form) of the isocyanurate and adduct forms of the hexamethylene diisocyanate, expressed as a mass ratio, is from 95/5 to 40/60.

A golf ball paint composition includes primarily a urethane paint containing polyol as a base resin and polyisocyanate as a curing agent. The polyisocyanate includes two types of isocyanurate and adduct of hexamethylene diisocyanate and the golf ball paint composition has an elastic work recovery of at least 70%. The paint composition has a high self-repairing ability and is of high quality as a golf ball paint. Golf balls coated with this composition are able to maintain a good durability, in addition to which they have an excellent abrasion resistance and an excellent ball appearance.

Golf ball paint composition

A golf ball wherein a slide amount Ds is 1.05 mm or less and a post-slide contact time Tc is 600 &#x3bc;s or more in the case where a golf ballis dropped freely from a height position of 3 m above and away from a collision surfaceinclined 58 degrees with respect to a horizontal direction to collide with the collision surface, the slide amount Ds being a vertical displacement of the golf ball from when the golf ball starts sliding on the collision surface to when the golf ball stops sliding on the collision surface, and the post-slide contact time Tc being a period from when the golf ball stops sliding on the collision surface to when the golf ball leaves the collision surface.

A golf ball having a cover with a plurality of dimples on the surface thereof is provided with a coat of mutually differing properties on dimple areas of the surface and on land areas between the dimples. The dimple areas are formed with a coat having a low coefficient of friction, do not affect the spin performance when the ball is struck and are not prone to staining. The land areas are formed with a coat having a high coefficient of friction, enabling a lower spin rate to be achieved and thus increasing the distance traveled by the ball, particularly when struck with a middle iron, and also help impart a high spin rate and a good controllability on approach shots.

To provide a golf ball that can prevent a decrease in carry distance of a driver shot when it rains and also, can exert excellent spinning performance upon an approach shot. The golf ball of the present invention includes a core, a cover that is provided on an outer side of the core and is provided with dimples, and an outermost layer that is formed on an outer side of the cover and made of a material having a contact angle of 90&#xb0; or more. The golf ball has a dynamic friction coefficient of 0.52 or more. The material constituting the outermost layer comprises a urethane coating that contains a water repellent additive, and the water repellent additive includes a fluorinated surfactant, silicone-modified acrylate or hydrophobic silica.

A matte golf ball which is free of luster and gloss has such a good ball appearance that the injection marks which form during injection molding of the cover are not visible. The golf ball includes a core of at least one layer, a cover of at least one layer, and a paint film. The outermost layer of the cover is formed of a resin composition which includes a thermoplastic resin and a colorant comprising a fluorescent dye or a fluorescent pigment, and has a visible light transmittance with an average value at wavelengths in the 380 to 780 nm spectrum of from 2.0 to 50.0%. The paint film is formed of a urethane-based paint composition containing delustering particles.

An evaluation method includes determining, by a computer processor, the times of occurrence of states of a golf ball during its contact with a collision surface, from the behavior of the golf ball based on its collision with the collision surface. A slide time or slide amount is calculated by the computer processor, based on the times of occurrence of the states. The slide time is a period from the start to the stop of a slide of the golf ball on the collision surface. The slide amount is the amount of the slide during the period. Information on the slide time or slide amount is output by the computer processor.

Golf ball evaluation method

In a golf ball having a core, a cover of at least one layer and a paint film layer formed on a surface of the cover, the paint film layer has an elastic work recovery of at least 60%, the cover layer in contact with the paint film layer has a material hardness on the Shore D scale of at least 55 and, letting M be the elastic work recovery (%) of the paint film layer and N be the material hardness (Shore D hardness) of the cover layer, M&#x2212;N&#x3e;0. The ball surface is scratch-resistant and has an excellent durability, and the ball has a reduced spin rate on shots with a driver or a long iron, resulting in an increased carry.

Growing community of inventors

Chichibu, Japan

Hirotaka Shinohara