Abstract: The present invention provides a coated golf ball having good appearance, excellent durability after repeated hitting, excellent abrasion resistance after washing by brushing and excellent stain resistance with a grass. The present invention relates to a coated golf ball formed by applying a paint on the surface of a golf ball body, wherein the paint comprises polyol containing urethane polyol as a main material and polyisocyanate curing agent, and the curing agent comprises 25 to 35% by weight of isocyanurate polyisocyanate derived from hexamethylene diisocyanate, 25 to 35% by weight of biuret polyisocyanate derived from hexamethylene diisocyanate and 35 to 50% by weight of isocyanurate polyisocyanate derived from isophorone diisocyanate.

Abstract: A ball body is formed with a mold having upper and lower mold half. Dimples 16 having a shape inverted from the shape of the pimples of the mold are formed on the ball body. The dimples 16 in the vicinity of the equatorial line have a size in the meridional direction D1 being greater than a size in the latitudinal direction D2. The difference between the size in the meridional direction D1 and the size in the latitudinal direction D2 is 0.01 mm or greater and 0.50 mm or less. By grinding the ball body in the vicinity of the equatorial line, a flash generated on the seam resulting form the mold is removed. According to the grinding, the size in the meridional direction of the dimple 16 is reduced, and thus, plane shape of the dimple becomes closer to a perfect circle.

Abstract: A multi-piece golf ball with improved carry without sacrificing properties like spin performance, durability, coefficient of restitution, and the feel when the ball is hit, the golf ball including a core, an intermediate layer surrounding the core, and the cover surrounding the intermediate layer, where a plurality of voids are distributed in at least one of the core, the intermediate layer or the cover along the spherical surface of the core or intermediate layer, or the cover. 20-600 voids are formed on at least one of the interfaces between the core and the intermediate layer, between a plurality of intermediate layers, or between the intermediate layer and the cover.

Abstract: A mold (1) includes an upper mold half (U) and a lower mold half (L). The mold (1) includes a gate (G), a pole vent pin (P), a support pin (S) and an intermediate vent pin (M). The support pin (S) has a latitude (&thgr;s) of 45 degrees to 85 degrees. Each of the upper mold half (U) and the lower mold half (L) has at least three support pins (S). The intermediate vent pin (M) has a latitude (&thgr;m) of 45 degrees to 85 degrees. Each of the upper mold half (U) and the lower mold half (L) has at least three intermediate vent pins (M). A difference between the latitude (&thgr;m) of the intermediate vent pin (M) and the latitude (&thgr;s) of the support pin (S) is equal to or smaller than 15 degrees. A clearance between the intermediate vent pin (M) and a pin hole (13) is 5 &mgr;m to 50 &mgr;m. By the mold (1), a cover having a thickness of 1.4 mm or less is formed.

Abstract: The object of the present invention is to provide a golf ball having the individualized appearance as well as the visibility, which the mark should inherently provide, by imparting the luster to the mark, without lowering the durability of the mark. The golf ball of the present invention comprises a mark on the surface of the golf ball body, and a clear coating layer covering the mark, the mark having a color tone satisfying L≦40 specified by Lab color system, wherein the clear coating layer includes the base resin; and the luster material comprising a glass flake and a metal oxide layer coated on the surface of the glass flake.

Abstract: Dimple 4 has a side wall curved face 8 and an edge neighboring curved face 9. The side wall curved face 8 is situated between a point P4 positioned downward from the dimple edge Ed by the depth of 20% in an in-depth direction and a point P3 positioned downward from the dimple edge Ed by the depth of 50% in an in-depth direction. The edge neighboring curved face 9 is situated between the dimple edge Ed and a point P5 positioned downward from the dimple edge Ed by the depth of 10% in an in-depth direction. Proportion of the number NL of dimples 4 having the diameter of equal to or greater than 3.90 mm occupied in total number N of the dimples is equal to or greater than 75%. Proportion of the number ML of dimples having the ratio (Re/Rw) between a radius of curvature of Re of the edge neighboring curved face 9 and a radius of curvature Rw of the side wall curved face 8 of 0.5 or greater and 1.5 or less of equal to or greater than 75%, having the diameter of equal to or greater than 3.

Abstract: A golf ball 1 includes an A dimple having a diameter of 4.35 mm, a B dimple having a diameter of 3.9 mm, a C dimple having a diameter of 3.4 mm, and a D dimple having a diameter of 3.2 mm. All the dimples have circular plane shapes. A ratio PN of a number Na of the circular dimples having the diameters of 3.9 mm to 4.8 mm to a total number N of the dimples is 75% or more. A volume Va of the circular dimples having the diameters of 3.9 mm to 4.8 mm is 200 mm3 to 300 mm3. A ratio PV of the volume Va to a total volume V of all the dimples is 70% to 95%. A surface area occupation ratio Y of all the dimples is 75% or more.

Abstract: The invention provides an improved golf ball printing method which is capable of efficient printing control in the production of golf balls and provides a colorful or lustrous mark on the ball surface. The printing method uses a two-component reacting ink comprising a resin having a hydroxyl group, an isocyanate, a coloring agent containing a metal, and a &bgr;-diketone. The ink ensures pot life more than eight hours and does not need to replace with newly prepared ink all day long.

Abstract: A golf ball comprises a large number of dimples (4) on a surface thereof. The dimple (4) includes a first curved surface (7) provided from a position (P2) placed downward by 85% of a depth to a position (P1) placed downward by 100% of the depth in a direction of the depth from an edge (E) and a second curved surface (8) provided from a position (P5) placed downward by 20% of the depth to a position (P3) placed downward by 50% of the depth in the direction of the depth from the edge (E). A percentage, to a total number of the dimples, of a number of the dimples in which a ratio (R1/R2) of a radius of curvature (R1) of the first curved surface (7) to a radius of curvature (R2) of the second curved surface (8) is 5 to 55 is 20% or more. A third curved surface (9) is present between the first curved surface (7) and the second curved surface (8). A fourth curved surface (10) is present between the second curved surface (8) and the edge (E).

Abstract: A screw (11) of an injection molding machine (6) is moved backward toward the right side and is rotated at the same time. Consequently, a pellet (18) in a supply section (15) is molten and is caused to enter a cylinder (10) at the same time. A shutter (16) is closed. By the operation of a vacuum pump (7), the supply section (15) is sucked. Consequently, the vicinity of the supply section (15) in the cylinder (10) is also sucked. A gas generated by melting the pellet (18) is led to the vacuum pump (7) through the supply section (15) and a pipe (19), and is discharged from the vacuum pump (7) to the outside. A molten resin is stored in a portion of the cylinder (10) which is provided in front of the screw (11). The screw (11) is moved forward and the molten resin is injected from a concave portion (9) toward a mold (8) so that a cover is formed. Since a small amount of the gas flows into the mold (8), the defects of a golf ball can be reduced.

Abstract: A multi-piece golf ball with improved carry without sacrificing properties like spin performance, durability, coefficient of restitution, and the feel when the ball is hit, the golf ball including a core, an intermediate layer surrounding the core, and the cover surrounding the intermediate layer, where a plurality of voids are distributed in at least one of the core, the intermediate layer or the cover along the spherical surface of the core or intermediate layer, or the cover. 20-600 voids are formed on at least one of the interfaces between the core and the intermediate layer, between a plurality of intermediate layers, or between the intermediate layer and the cover.

Abstract: Golf ball 1 has a core 2 and a cover 3. The core 2 is composed of a center 4 and a mid layer 5. Numerous dimples 6 are formed on the surface of the cover 3. Base polymer of the cover 3 includes a mixture of an ionomer resin and a thermoplastic elastomer as a principal component. Shore D hardness of this cover 3 is 55 or greater and 70 or less. A proportion of number of dimples 6 having the tilt angle &agr; of from the position, which is 20% downward from the dimple edge in an in-depth direction, down to the position, which is 50% downward from the dimple edge, of 65° or greater and 85° or less occupied in total number of dimples is equal to or greater than 20%.

Abstract: The object of the present invention is to provide a golf ball having the individualized appearance as well as the visibility, which the mark should inherently provide, by imparting the luster to the mark, without lowering the durability of the mark.

Abstract: The present invention provides a multi-piece solid golf ball having soft and good shot feel and excellent flight performance when hit by a golfer who swings a golf club at low head speed. The present invention relates to a multi-piece solid golf ball comprising a core, an intermediate layer and a cover having many dimples on the surface thereof, wherein hardness distribution of the core; hardness distribution between each layer and the contiguous layer in the golf ball; a ratio of a thickness of the cover to that of the intermediate layer; a ratio (X/D) of the total periphery length (X) to a diameter of the golf ball; and a ratio (VD/VG) of the total volume of the dimples (VD) to a volume of the phantom sphere (VG) assuming that the golf ball is a true sphere having no dimples on the surface thereof; are adjusted to specified ranges.

Abstract: The present invention provides a three-piece solid golf ball, of which flight distance is improved by accomplishing high launch angle and low spin amount in initial flight performance, while maintaining good shot feel such that the rebound characteristics are good, when hit at low head speed. The present invention relates to a three-piece solid golf ball comprising a center, an intermediate layer and a cover having many dimples on the surface thereof, wherein hardness distribution of the center; hardness distribution between each layer and the contiguous layer in the golf ball; and a ratio of the golf ball surface area occupied by the dimple to the total surface area of the golf ball and the total of a periphery length of the dimple; are adjusted to specified ranges.

Abstract: Golf ball 1 has the diameter D of 43.0 mm or greater and 50.0 mm or less. This golf ball 1 includes a core 2 and a cover 3. The core 2 is formed by crosslinking of a rubber composition. The cover 3 is composed of a resin composition. Dimples 4 are formed on the surface of the cover 3. The specific gravity of the cover 3 is 1.05 or greater and 1.50 or less. The moment of inertia of this golf ball 1 is equal to or greater than 85.0 gcm2, and particularly equal to or greater than 88.0 gcm2.

Abstract: The present invention provides a coated golf ball having good appearance, excellent durability after repeated hitting, excellent abrasion resistance after washing by brushing and excellent stain resistance with a grass. The present invention relates to a coated golf ball formed by applying a paint on the surface of a golf ball body, wherein the paint comprises polyol containing urethane polyol as a main material and polyisocyanate curing agent, and the curing agent comprises 25 to 35% by weight of isocyanurate polyisocyanate derived from hexamethylene diisocyanate, 25 to 35% by weight of biuret polyisocyanate derived from hexamethylene diisocyanate and 35 to 50% by weight of isocyanurate polyisocyanate derived from isophorone diisocyanate.

Abstract: A mold for a golf ball comprises an upper portion (1) and a lower portion (3). A large number of projections (7) for dimple formation are provided on a cavity surface (5) of each of the upper portion (1) and the lower portion (3). A parting surface (8) of the upper portion (1) and the lower portion (3) has a concavo-convex shape. The parting surface (8) includes a first horizontal plane (13), a second horizontal plane (15) and an inclined surface (17). Circumferential central angles &phgr; of the first horizontal plane (13) and the second horizontal plane (15) are 55 degrees or less. A total value &Sgr;&phgr; of the circumferential central angles &phgr; is 30 degrees to 330 degrees. An inclination angle &agr; of the inclined surface (17) to a horizontal direction is 10 degrees to 60 degrees. A central angle &thgr; between the horizontal planes (13) and (15) and an equator (E) is 1 degree to 8 degrees.

Abstract: The present invention provides a multi-piece solid golf ball having very good shot feel, excellent rebound characteristics and excellent flight performance.

Abstract: A coated golf ball is provided of which possible flaw or paint peeling caused by shots does not become conspicuous even after it has been left outdoors for a long time. The coated golf ball comprises a ball body having a surface layer containing a white pigment and essentially free of a fluorescent brightener and an ultraviolet absorber, and a paint layer containing the fluorescent brightener and the ultraviolet absorber. The ball body as well as the coated golf ball has a color tone represented by CIE L*a*b* color system: 88≦L*≦93, −2≦a*≦2, and −12≦b*≦−5. Differences in “L*”, “a*” and “b*” values between the color tone of the ball body and one of the coated golf ball are not more than 2, not more than 3, and not more than 3, respectively.