Sumitomo Rubber Industries Limited

Sri Sports Limited

Dunlop Sports Company Limited

Other

Masatoshi Yokota

Seiichiro Endo

Koichi Fujisawa

Keiji Moriyama

Kazuhiko Isogawa

Satoshi Iwami

Satoko Okabe

Masaaki Kikuchi

Hidenori Hiraoka

Kuniyasu Horiuchi

Seigou Sakagami

Yusuke Tanigawa

Keiji Ohama

Kiyoto Maruoka

Akira Kato

Mikio Yamada

Satoshi Mano

Takahiro Sajima

Kazuyoshi Shiga

Toshiyuki Tarao

Takahiro Shigemitsu

Takashi Nakamura

Hiroaki Tanaka

Tetsuo Yamaguchi

Hiroyuki Kishimoto

Tsutomu Hirau

Kazushige Sugimoto

Kaname Yamada

Yoshiko Matsuyama

Kai Hayashi

Kohei Takemura

Hirokazu Okamoto

Kaichiro Wayaku

Yoshiyuki Nakai

Yoshihiko Komori

Kazuo Yagi

An object of the present invention is to provide a golf ball having excellent color development stability. The present invention provides a golf ball comprising a core and a cover covering the core, wherein the cover is formed from a resin composition containing a first base resin and a fluorescent pigment, and the fluorescent pigment has a number-based cumulative median size of 2.5 μm or more.

Golf ball

An object of the present invention is to provide a golf ball excellent in hitting durability. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein at least a part of the spherical core is formed from a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (x) an olefin-alkyl (meth)acrylate copolymer, and a content of (x) the olefin-alkyl (meth)acrylate copolymer in the rubber composition ranges from 0.5 part by mass to 7.0 parts by mass with respect to 100 parts by mass of (a) the base rubber.

An object of the present invention is to provide a golf ball showing improved durability by improving adhesion to a constituent member comprising a polyurethane in the golf ball. The present invention provides a golf ball comprising a center and n envelope layers (n is a natural number of 1 or more) covering the center, wherein at least one envelope layer is a polyurethane envelope layer comprising a polyurethane as a principal component, and the polyurethane envelope layer and a constituent member adjacent to the polyurethane envelope layer are adhered with an adhesive resin composition, and wherein the adhesive resin composition comprises a base material including a urethane polyol and an epoxy resin, and a curing agent including a polyamine compound, and a content of the urethane polyol in the base material is 5 mass % or more and less than 40 mass %.

An object of the present invention is to provide a golf ball showing excellent impact durability. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the golf ball comprises a reinforcing layer containing a polyvinyl acetal resin on the surface of the spherical core.

An object of the present invention is to provide a method for manufacturing a golf ball excellent in kneading workability when preparing a core rubber composition containing (d) a carboxylic acid and/or a salt thereof. The present invention provides a method for manufacturing a golf ball comprising the steps of blending (a) a base rubber and at least (b) a carboxylic acid and/or a salt thereof to prepare a first masterbatch; blending (a) a base rubber and at least (c) a crosslinking initiator to prepare a second masterbatch; blending the first masterbatch and second masterbatch to form a core rubber composition; molding the core rubber composition into a spherical core; and forming one or more cover layers covering the spherical core.

Method for manufacturing a golf ball

An object of the present invention is to provide a novel method of manufacturing a golf ball comprising forming a spherical core having less-variable compression deformation amount and stabilized properties. The present invention provides a method for manufacturing a golf ball, comprising the steps of: blending (a) a base rubber, (b) an &#x3b1;,&#x3b2;-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, (c) a crosslinking initiator, (d) a carboxylic acid and/or a salt thereof having a number-average particle size ranging from 15 &#x3bc;m to 60 &#x3bc;m, and (e) where necessary a metal compound to prepare a core rubber composition; molding the core rubber composition into a spherical core under specific conditions; and forming at least one cover layer on the spherical core.

Method for manufacturing golf ball

An object of the present invention is to provide a golf ball comprising a core formed from a rubber composition containing (d) a carboxylic acid and/or a salt thereof and traveling a great flight distance on driver shots. The present invention provides a golf ball comprising a spherical core and at least one cover layer covering the spherical core, wherein the spherical core is formed from a rubber composition containing (a) a base rubber, (b) an &#x3b1;,&#x3b2;-unsaturated carboxylic acid having 3 to 8 carbon atoms and/or a metal salt thereof as a co-crosslinking agent, (c) a crosslinking initiator, (d) a carboxylic acid and/or a salt thereof and two or more kinds of (e) organic sulfur compounds, provided that the rubber composition further contains (f) a metal compound in case of containing only (b) the &#x3b1;,&#x3b2;-unsaturated carboxylic acid having 3 to 8 carbon atoms as the co-crosslinking agent.

Golf ball and method for manufacturing the same

When a length of a cross section CSin a face-back direction is defined as L; a point being 0.1L from a forefront point Mzof the cross section and positioned on an outer surface of the sole is defined as Ma; a point being 0.2L from a backmost point Mkof the cross section and positioned on the outer surface of the sole is defined as Md; intersection points of lines and the outer surface of the sole are defined as a point Mb and a point Mc from a face side in order, the lines equally dividing a distance between the point Ma and the point Md into three in the face-back direction; a distance of a cross section CSin the toe-heel direction is defined as W; intersection points of lines and the outer surface of the sole are defined as a point Mp, a point Mq, and a point Mr from a toe side in order, the lines equally dividing the distance W into four in the toe-heel direction; a radius of a circle passing through the point Ma, the point Mb, and the point Mc is defined as Ra; a radius of a circle passing through the point Mb, the point Mc, and the point Md is defined as Rb; and a radius of a circle passing through the point Mp, the point Mq, and the point Mr is defined as Rc, Ra&#x3e;Rb&#x3e;Rc is satisfied.

Golf club head

Golf ballhas a spherical core, a mid layercovering this core, a reinforcing layercovering this mid layer, and a covercovering this reinforcing layer. Base polymer of the mid layerincludes an ionomer resin as a principal component. The mid layerhas a hardness Hm as measured with a Shore D type hardness scale of equal to or greater than 55. Base polymer of the reinforcing layeris a thermosetting resin. Base polymer of the coverincludes a thermoplastic polyurethane elastomer as a principal component. The coverhas a thickness Tc of equal to or less than 0.6 mm. The cover has a hardness Hc as measured with a Shore D type hardness scale of equal to or less than 54. Ratio (Tr/Tc) of the thickness Tr of the reinforcing layer to the thickness Tc of the cover is 0.005 or greater and 3.0 or less.

A golf club head has a hollow structure comprising a main body member and a face member. The face member is made of an unidirectionally rolled plate of a titanium alloy having alpha phase crystals. The rolled direction of the unidirectionally rolled plate is inclined at an angle &#x3b8;of not more than 30 degrees with respect to the horizontal direction. The face member is provided on the rear face with a ribbed part having its longitudinal direction inclined at an angle &#x3b8;of not more than 30 degrees with respect to the vertical direction. A method for manufacturing the golf club head comprises a step of preparing the face member which comprises the steps of: preparing the unidirectionally rolled plate; cutting out a blank for the face member from the unidirectionally rolled plate; and forming the ribbed part on the cutout blank by machining.

Golf club head and method for manufacturing the same

A headhas a face linehaving a depth of D(mm). When a boundary between a land area and a face line is defined as a point Pa; a point of which a depth is [D/4] (mm) is defined as a point Pb; a point of which a depth is [D/2] (mm) is defined as a point Pc; a point of which a depth is [(D)&#xd7;(&#xbe;)] (mm) is defined as a point Pd; a point of which a depth is 0.002 (mm) is defined as a point Px; a radius of a circle CLpassing through three points of the point Pa, the point Pb, and the point Pc is defined as R(mm); a straight line passing through the point Pa and the point Px is defined as a straight line Lax; and an angle between the land area and the straight line Lax is defined as &#x3b8;(degree), the radius Ris 0.2 (mm) or greater and 0.4 (mm) or less, and the angle &#x3b8;is 10 degrees or greater and 50 degrees or less.

A golf club head comprises a face portion improved in the durability by increasing the strength of the toe-side upper region of the face portion. The face portion is formed from a unidirectionally rolled plate of a titanium alloy having alpha phase, and at least in the toe-side upper region, the titanium alloy has alpha phase crystals of a hexagonal closely packed structure whose hexagonal symmetry axis (a) is oriented in the direction of a line (k) drawn between the sweet spot (SS) and the toe end point (TP).

A hollow wood-type golf club headcapable of controlling the spring effect without excessively increasing the weight of a face portion, the club headcomprising a face portionhaving a facefor hitting a golf ball, a sole portionconstituting the bottom of the club head, and a junctioninterconnecting the face portion and the sole portion and including at least one thick wall portionhaving a thickness tlarger than a thickness tat a lower edge of the face portionand having a length L of 20 mm or more wherein the length L is a total of lengths in a toe-heel direction of said at least one thick wall portion

Wood-type golf club head

Golf club headis provided including face member, crown member, sole memberand recessed part. The recessed partis provided around the sole member. The recessed parthas a maximum height Hm of equal to or greater than 10 mm. The projected area Sof the sole memberprojected on the reference plane accounts for 40% or more and 65% or less of the projected area Sof the crown memberprojected on the reference plane. The headis hollow. Preferably, the maximum angle &#x3b8;m formed between the margin Fof the recessed partand the sole edge Ein proximity thereto is equal to or greater than 45 degrees. Preferably, the curvature radius of the sole face in a toe-heel direction is 9.0 cm or greater and 11.5 cm or less. Preferably, the headhas a volume of 400 cc or more and 500 cc or less.

The present invention provides a golf ball having excellent rebound characteristics and flight performance, while maintaining good durability and appearance. The present invention relates to a golf ball comprising a center, an intermediate layer and a cover, the intermediate layer comprises an outermost layer and a second layer adjacent to the underside of the outermost layer, and the cover has many dimples on the surface thereof, wherein the second layer is formed from thermoplastic resin and has a thickness of 0.5 to 2.0 mm, the outermost layer is formed from thermosetting or thermoplastic resin and has a thickness of 1 to 100 &#x3bc;m, the intermediate layer has depressions on the surface thereof at the position and shape corresponding to the dimples through the cover, and the cover is formed from thermoplastic resin and has a thickness of 0.1 to 0.8 mm in land portion having no dimple.

Growing community of inventors

Kobe, Japan

Masatoshi Yokota