US2013288824A1PendingUtilityA1

Golf ball

53
Assignee: DUNLOP SPORTS CO LTDPriority: Apr 25, 2012Filed: Mar 14, 2013Published: Oct 31, 2013
Est. expiryApr 25, 2032(~5.8 yrs left)· nominal 20-yr term from priority
Inventors:Kazuhiko IsogawaKosuke Tachibana
A63B 37/0092A63B 37/0076A63B 37/0063A63B 37/0059A63B 37/0044A63B 37/0043A63B 37/0054
53
PatentIndex Score
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Claims

Abstract

A golf ball 2 includes a spherical core 4 , an inner mid layer 6 , an outer mid layer 8 , a reinforcing layer 10 , and a cover 12 . When distances (%) from a central point of the core 4 to nine points and JIS-C hardnesses at the nine points, which nine points are obtained by dividing a region from the central point of the core 4 to a surface of the core 4 at intervals of 12.5% of a radius of the core 4 , are plotted in a graph, R 2 of a linear approximation curve obtained by a least-square method is equal to or greater than 0.95. Hm1 is greater than Hm2. Hc is less than Hm1. T2 is equal to or greater than 0.5 mm but equal to or less than 1.6 mm.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
         1 . A golf ball comprising a spherical core, an inner mid layer positioned outside the core, an outer mid layer positioned outside the inner mid layer, and a cover positioned outside the outer mid layer, wherein
 when distances (%) from a central point of the core to nine points and JIS-C hardnesses at the nine points, which nine points are obtained by dividing a region from the central point of the core to a surface of the core at intervals of 12.5% of a radius of the core, are plotted in a graph, R 2  of a linear approximation curve obtained by a least-square method is equal to or greater than 0.95,   a Shore D hardness Hm1 of the inner mid layer is greater than a Shore D hardness Hm2 of the outer mid layer,   a Shore D hardness Hc of the cover is less than the hardness Hm1, and   a thickness T2 of the outer mid layer is equal to or greater than 0.5 mm but equal to or less than 1.6 mm.   
     
     
         2 . The golf ball according to  claim 1 , wherein
 a JIS-C hardness H(0.0) at the central point of the core is equal to or greater than 40 but equal to or less than 70, and   a surface hardness Hs of the core is equal to or greater than 78 but equal to or less than 96.   
     
     
         3 . The golf ball according to  claim 1 , wherein a difference (Hs−H(0.0)) between a surface hardness Hs of the core and a JIS-C hardness H(0.0) at the central point of the core is equal to or greater than 15. 
     
     
         4 . The golf ball according to  claim 1 , wherein a difference (Hm1−Hm2) between the hardness Hm1 and the hardness Hm2 is equal to or greater than 8. 
     
     
         5 . The golf ball according to  claim 1 , wherein a difference (Hm1−Hc) between the hardness Hm1 and the hardness Hc is equal to or greater than 30. 
     
     
         6 . The golf ball according to  claim 1 , wherein
 a sum (T1+T2) of a thickness T1 of the inner mid layer and the thickness T2 is equal to or greater than 1.0 mm but equal to or less than 3.0 mm, and   a thickness Tc of the cover is equal to or less than 0.8 mm.   
     
     
         7 . The golf ball according to  claim 1 , wherein
 the core is obtained by a rubber composition being crosslinked,   the rubber composition includes:
 (a) a base rubber; 
 (b) a co-crosslinking agent; 
 (c) a crosslinking initiator; and 
 (d) an acid and/or a salt, and 
   the co-crosslinking agent (b) is:
 (b1) an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms; and/or 
 (b2) a metal salt of an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms. 
   
     
     
         8 . The golf ball according to  claim 7 , wherein the acid and/or the salt (d) is a carboxylic acid and/or a salt thereof (d1). 
     
     
         9 . The golf ball according to  claim 8 , wherein a carbon number of a carboxylic acid component of the carboxylic acid and/or the salt thereof (d1) is equal to or greater than 1 but equal to or less than 30. 
     
     
         10 . The golf ball according to  claim 8 , wherein the carboxylic acid and/or the salt thereof (d1) is a fatty acid and/or a salt thereof. 
     
     
         11 . The golf ball according to  claim 8 , wherein the carboxylic acid and/or the salt thereof (d1) is a zinc salt of a carboxylic acid. 
     
     
         12 . The golf ball according to  claim 8 , wherein the carboxylic acid and/or the salt thereof (d1) is one or more members selected from the group consisting of zinc octoate, zinc laurate, zinc myristate, and zinc stearate. 
     
     
         13 . The golf ball according to  claim 7 , wherein the rubber composition includes 100 parts by weight of the base rubber (a) and 1.0 parts by weight or greater but 40 parts by weight or less of the acid and/or the salt (d). 
     
     
         14 . The golf ball according to  claim 7 , wherein
 the rubber composition includes the α,β-unsaturated carboxylic acid (b1), and   the rubber composition further includes a metal compound (e).   
     
     
         15 . The golf ball according to  claim 7 , wherein the rubber composition includes 100 parts by weight of the base rubber (a) and 15 parts by weight or greater but 50 parts by weight or less of the co-crosslinking agent (b). 
     
     
         16 . The golf ball according to  claim 7 , wherein the rubber composition includes 100 parts by weight of the base rubber (a) and 0.2 parts by weight or greater but 5 parts by weight or less of the crosslinking initiator (c). 
     
     
         17 . The golf ball according to  claim 7 , wherein the rubber composition includes the metal salt (b2) of the α,β-unsaturated carboxylic acid. 
     
     
         18 . The golf ball according to  claim 1 , wherein
 the outer mid layer is formed from a resin composition,   the cover is formed from another resin composition,   a principal component of a base resin of the resin composition of the outer mid layer is different from a principal component of a base resin of the resin composition of the cover, and   the golf ball further comprises a reinforcing layer between the outer mid layer and the cover.   
     
     
         19 . The golf ball according to  claim 7 , wherein the rubber composition further includes an organic sulfur compound (f). 
     
     
         20 . The golf ball according to  claim 19 , wherein the organic sulfur compound (f) is at least one member selected from the group consisting of thiophenols, diphenyl disulfides, thionaphthols, thiuram disulfides, and metal salts thereof. 
     
     
         21 . The golf ball according to  claim 19 , wherein the rubber composition includes 100 parts by weight of the base rubber (a) and 0.05 parts by weight or greater but 5 parts by weight or less of the organic sulfur compound (f). 
     
     
         22 . A golf ball comprising a spherical core, an inner mid layer positioned outside the core, an outer mid layer positioned outside the inner mid layer, and a cover positioned outside the outer mid layer, wherein
 when distances (%) from a central point of the core to nine points and JIS-C hardnesses at the nine points, which nine points are obtained by dividing a region from the central point of the core to a surface of the core at intervals of 12.5% of a radius of the core, are plotted in a graph, R 2  of a linear approximation curve obtained by a least-square method is equal to or greater than 0.95,   a Shore D hardness Hm2 of the outer mid layer is greater than a Shore D hardness Hm1 of the inner mid layer,   a Shore D hardness Hc of the cover is less than the hardness Hm2, and   the hardness Hm1 is less than 50.   
     
     
         23 . The golf ball according to  claim 22 , wherein
 a JIS-C hardness H(0.0) at the central point of the core is equal to or greater than 40 but equal to or less than 70, and   a surface hardness Hs of the core is equal to or greater than 78 but equal to or less than 96.   
     
     
         24 . The golf ball according to  claim 22 , wherein a difference (Hs−H(0.0)) between a surface hardness Hs of the core and a JIS-C hardness H(0.0) at the central point of the core is equal to or greater than 15. 
     
     
         25 . The golf ball according to  claim 22 , wherein a difference (Hm2−Hm1) between the hardness Hm2 and the hardness Hm1 is equal to or greater than 10. 
     
     
         26 . The golf ball according to  claim 22 , wherein a difference (Hm2−Hc) between the hardness Hm2 and the hardness Hc is equal to or greater than 30. 
     
     
         27 . The golf ball according to  claim 22 , wherein a sum (T1+T2) of a thickness T1 of the inner mid layer and a thickness T2 of the outer mid layer is equal to or greater than 1.0 mm but equal to or less than 3.0 mm, and
 a thickness Tc of the cover is equal to or less than 0.8 mm.   
     
     
         28 . The golf ball according to  claim 22 , wherein
 the core is obtained by a rubber composition being crosslinked,   the rubber composition includes:
 (a) a base rubber; 
 (b) a co-crosslinking agent; 
 (c) a crosslinking initiator; and 
 (d) an acid and/or a salt, and 
   the co-crosslinking agent (b) is:
 (b1) an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms; and/or 
 (b2) a metal salt of an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms. 
   
     
     
         29 . The golf ball according to  claim 28 , wherein the acid and/or the salt (d) is a carboxylic acid and/or a salt thereof (d1). 
     
     
         30 . The golf ball according to  claim 29 , wherein a carbon number of a carboxylic acid component of the carboxylic acid and/or the salt thereof (d1) is equal to or greater than 1 but equal to or less than 30. 
     
     
         31 . The golf ball according to  claim 29 , wherein the carboxylic acid and/or the salt thereof (d1) is a fatty acid and/or a salt thereof. 
     
     
         32 . The golf ball according to  claim 29 , wherein the carboxylic acid and/or the salt thereof (d1) is a zinc salt of a carboxylic acid. 
     
     
         33 . The golf ball according to  claim 29 , wherein the carboxylic acid and/or the salt thereof (d1) is one or more members selected from the group consisting of zinc octoate, zinc laurate, zinc myristate, and zinc stearate. 
     
     
         34 . The golf ball according to  claim 28 , wherein the rubber composition includes 100 parts by weight of the base rubber (a) and 1.0 parts by weight or greater but 40 parts by weight or less of the acid and/or the salt (d). 
     
     
         35 . The golf ball according to  claim 28 , wherein
 the rubber composition includes the α,β-unsaturated carboxylic acid (b1), and   the rubber composition further includes a metal compound (e).   
     
     
         36 . The golf ball according to  claim 28 , wherein the rubber composition includes 100 parts by weight of the base rubber (a) and 15 parts by weight or greater but 50 parts by weight or less of the co-crosslinking agent (b). 
     
     
         37 . The golf ball according to  claim 28 , wherein the rubber composition includes 100 parts by weight of the base rubber (a) and 0.2 parts by weight or greater but 5 parts by weight or less of the crosslinking initiator (c). 
     
     
         38 . The golf ball according to  claim 28 , wherein the rubber composition includes the metal salt (b2) of the α,β-unsaturated carboxylic acid. 
     
     
         39 . The golf ball according to  claim 22 , wherein
 the outer mid layer is formed from a resin composition,   the cover is formed from another resin composition,   a principal component of a base resin of the resin composition of the outer mid layer is different from a principal component of a base resin of the resin composition of the cover, and   the golf ball further comprises a reinforcing layer between the outer mid layer and the cover.   
     
     
         40 . The golf ball according to  claim 28 , wherein the rubber composition further includes an organic sulfur compound (f). 
     
     
         41 . The golf ball according to  claim 40 , wherein the organic sulfur compound (f) is at least one member selected from the group consisting of thiophenols, diphenyl disulfides, thionaphthols, thiuram disulfides, and metal salts thereof. 
     
     
         42 . The golf ball according to  claim 40 , wherein the rubber composition includes 100 parts by weight of the base rubber (a) and 0.05 parts by weight or greater but 5 parts by weight or less of the organic sulfur compound (f). 
     
     
         43 . A golf ball comprising a core, a mid layer positioned outside the core, an inner cover positioned outside the mid layer, and an outer cover positioned outside the inner cover, wherein
 when distances (%) from a central point of the core to nine points and JIS-C hardnesses at the nine points, which nine points are obtained by dividing a region from the central point of the core to a surface of the core at intervals of 12.5% of a radius of the core, are plotted in a graph, R 2  of a linear approximation curve obtained by a least-square method is equal to or greater than 0.95,   a Shore D hardness Hm of the mid layer is greater than a Shore D hardness Hc1 of the inner cover,   the hardness Hm is greater than a Shore D hardness Hc2 of the outer cover, and   a thickness T1 of the inner cover is equal to or greater than 0.1 mm but equal to or less than 0.8 mm.   
     
     
         44 . The golf ball according to  claim 43 , wherein the hardness Hc1 is greater than the hardness Hc2. 
     
     
         45 . The golf ball according to  claim 43 , wherein
 a JIS-C hardness H(0) at the central point of the core is equal to or greater than 40 but equal to or less than 70, and   a JIS-C hardness Hs at the surface of the core is equal to or greater than 78 but equal to or less than 96.   
     
     
         46 . The golf ball according to  claim 43 , wherein a difference (Hm−Hc1) between the hardness Hm and the hardness Hc1 is equal to or greater than 15. 
     
     
         47 . The golf ball according to  claim 43 , wherein a difference (Hm−Hc2) between the hardness Hm and the hardness Hc2 is equal to or greater than 20. 
     
     
         48 . The golf ball according to  claim 43 , wherein a difference (Hs−H(0)) between a JIS-C hardness Hs at the surface of the core and a JIS-C hardness H(0) at the central point of the core is equal to or greater than 15. 
     
     
         49 . The golf ball according to  claim 43 , wherein a thickness Tm of the mid layer is equal to or greater than 0.5 mm but equal to or less than 1.6 mm. 
     
     
         50 . The golf ball according to  claim 43 , wherein a thickness T2 of the outer cover is equal to or greater than 0.1 mm but equal to or less than 0.8 mm. 
     
     
         51 . The golf ball according to  claim 43 , wherein a difference (T1−T2) between the thickness T1 of the inner cover and a thickness T2 of the outer cover is equal to or greater than −0.4 mm but equal to or less than 0.4 mm. 
     
     
         52 . The golf ball according to  claim 43 , wherein a sum (T1+T2) of the thickness T1 of the inner cover and a thickness T2 of the outer cover is equal to or less than 1.0 mm. 
     
     
         53 . The golf ball according to  claim 43 , wherein
 the core is formed by a rubber composition being crosslinked,   the rubber composition includes:
 (a) a base rubber; 
 (b) a co-crosslinking agent; 
 (c) a crosslinking initiator; and 
 (d) an acid and/or a salt, and 
   the co-crosslinking agent (b) is:
 (b1) an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms; and/or 
 (b2) a metal salt of an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms. 
   
     
     
         54 . The golf ball according to  claim 53 , wherein an amount of the acid and/or the salt (d) is equal to or greater than 1.0 parts by weight but less than 40 parts by weight, per 100 parts by weight of the base rubber (a). 
     
     
         55 . The golf ball according to  claim 53 , wherein the acid and/or the salt (d) is a carboxylic acid and/or a salt thereof (d1). 
     
     
         56 . The golf ball according to  claim 55 , wherein the carboxylic acid and/or the salt thereof (d1) is a fatty acid and/or a salt thereof. 
     
     
         57 . The golf ball according to  claim 55 , wherein a carbon number of a carboxylic acid component of the carboxylic acid and/or the salt thereof (d1) is equal to or greater than 1 but equal to or less than 30. 
     
     
         58 . The golf ball according to  claim 55 , wherein the carboxylic acid and/or the salt thereof (d1) is a zinc salt of a carboxylic acid. 
     
     
         59 . The golf ball according to  claim 58 , wherein the zinc salt of the carboxylic acid is one or more members selected from the group consisting of zinc octoate, zinc laurate, zinc myristate, and zinc stearate. 
     
     
         60 . The golf ball according to  claim 53 , wherein the rubber composition includes 15 parts by weight or greater but 50 parts by weight or less of the co-crosslinking agent (b) per 100 parts by weight of the base rubber (a). 
     
     
         61 . The golf ball according to  claim 53 , wherein the rubber composition includes 0.2 parts by weight or greater but 5.0 parts by weight or less of the crosslinking initiator (c) per 100 parts by weight of the base rubber (a). 
     
     
         62 . The golf ball according to  claim 53 , wherein the rubber composition further includes an organic sulfur compound (f). 
     
     
         63 . The golf ball according to  claim 62 , wherein the organic sulfur compound (f) is at least one member selected from the group consisting of thiophenols, diphenyl disulfides, thionaphthols, thiuram disulfides, and metal salts thereof. 
     
     
         64 . The golf ball according to  claim 62 , wherein the rubber composition includes 0.05 parts by weight or greater but 5.0 parts by weight or less of the organic sulfur compound (f) per 100 parts by weight of the base rubber (a). 
     
     
         65 . The golf ball according to  claim 53 , wherein the rubber composition includes the metal salt (b2) of the α,β-unsaturated carboxylic acid. 
     
     
         66 . The golf ball according to  claim 53 , wherein
 the rubber composition includes the α,β-unsaturated carboxylic acid (b1), and   the rubber composition further includes a metal compound (e).   
     
     
         67 . The golf ball according to  claim 43 , wherein
 the mid layer is formed from a resin composition;   the inner cover is formed from a resin composition whose base resin is different from a base resin of the mid layer, and   the golf ball further comprises a reinforcing layer between the mid layer and the inner cover.   
     
     
         68 . A golf ball comprising a core, amid layer positioned outside the core, an inner cover positioned outside the mid layer, and an outer cover positioned outside the inner cover, wherein
 when distances (%) from a central point of the core to nine points and JIS-C hardnesses at the nine points, which nine points are obtained by dividing a region from the central point of the core to a surface of the core at intervals of 12.5% of a radius of the core, are plotted in a graph, R 2  of a linear approximation curve obtained by a least-square method is equal to or greater than 0.95,   a Shore D hardness Hm of the mid layer is greater than a Shore D hardness Hc1 of the inner cover, and   a Shore D hardness Hc2 of the outer cover is greater than the hardness Hc1.   
     
     
         69 . The golf ball according to  claim 68 , wherein a difference (Hm−Hc1) between the hardness Hm and the hardness Hc1 is equal to or greater than 20. 
     
     
         70 . The golf ball according to  claim 68 , wherein the difference (Hc2−Hc1) between the hardness Hc2 and the hardness Hc1 is equal to or greater than 5. 
     
     
         71 . The golf ball according to  claim 68 , wherein
 the hardness Hm is greater than the hardness Hc2, and   a difference (Hm−Hc2) between the hardness Hm and the hardness Hc2 is equal to or greater than 15.   
     
     
         72 . The golf ball according to  claim 68 , wherein
 a JIS-C hardness H(0) at the central point of the core is equal to or greater than 40 but equal to or less than 70, and   a JIS-C hardness Hs at the surface of the core is equal to or greater than 78 but equal to or less than 96.   
     
     
         73 . The golf ball according to  claim 68 , wherein a difference (Hs−H(0)) between a JIS-C hardness Hs at the surface of the core and a JIS-C hardness H(0) at the central point of the core is equal to or greater than 15. 
     
     
         74 . The golf ball according to  claim 68 , wherein a thickness Tm of the mid layer is equal to or greater than 0.5 mm but equal to or less than 1.6 mm. 
     
     
         75 . The golf ball according to  claim 68 , wherein
 a thickness T1 of the inner cover is equal to or greater than 0.1 mm but equal to or less than 0.8 mm, and   a thickness T2 of the outer cover is equal to or greater than 0.1 mm but equal to or less than 0.8 mm.   
     
     
         76 . The golf ball according to  claim 68 , wherein a difference (T1−T2) between a thickness T1 of the inner cover and a thickness T2 of the outer cover is equal to or greater than −0.4 mm but equal to or less than 0.4 mm. 
     
     
         77 . The golf ball according to  claim 68 , wherein a sum (T1+T2) of a thickness T1 of the inner cover and a thickness T2 of the outer cover is equal to or less than 1.0 mm. 
     
     
         78 . The golf ball according to  claim 68 , wherein
 the core is formed by a rubber composition being crosslinked,   the rubber composition includes:
 (a) a base rubber; 
 (b) a co-crosslinking agent; 
 (c) a crosslinking initiator; and 
 (d) an acid and/or a salt, and 
   the co-crosslinking agent (b) is:
 (b1) an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms; and/or 
 (b2) a metal salt of an α,β-unsaturated carboxylic acid having 3 to 8 carbon atoms. 
   
     
     
         79 . The golf ball according to  claim 78 , wherein an amount of the acid and/or the salt (d) is equal to or greater than 0.5 parts by weight but equal to or less than 40 parts by weight, per 100 parts by weight of the base rubber (a). 
     
     
         80 . The golf ball according to  claim 78 , wherein the acid and/or the salt (d) is a carboxylic acid and/or a salt thereof (d1). 
     
     
         81 . The golf ball according to  claim 80 , wherein the carboxylic acid and/or the salt thereof (d1) is a fatty acid and/or a salt thereof. 
     
     
         82 . The golf ball according to  claim 80 , wherein a carbon number of a carboxylic acid component of the carboxylic acid and/or the salt thereof (d1) is equal to or greater than 1 but equal to or less than 30. 
     
     
         83 . The golf ball according to  claim 80 , wherein the carboxylic acid and/or the salt thereof (d1) is a zinc salt of a carboxylic acid. 
     
     
         84 . The golf ball according to  claim 83 , wherein the zinc salt of the carboxylic acid is one or more members selected from the group consisting of zinc octoate, zinc laurate, zinc myristate, and zinc stearate. 
     
     
         85 . The golf ball according to  claim 78 , wherein the rubber composition includes 15 parts by weight or greater but 50 parts by weight or less of the co-crosslinking agent (b) per 100 parts by weight of the base rubber (a). 
     
     
         86 . The golf ball according to  claim 78 , wherein the rubber composition includes 0.2 parts by weight or greater but 5.0 parts by weight or less of the crosslinking initiator (c) per 100 parts by weight of the base rubber (a). 
     
     
         87 . The golf ball according to  claim 78 , wherein the rubber composition further includes an organic sulfur compound (f). 
     
     
         88 . The golf ball according to  claim 87 , wherein the organic sulfur compound (f) is at least one member selected from the group consisting of thiophenols, diphenyl disulfides, thionaphthols, thiuram disulfides, and metal salts thereof. 
     
     
         89 . The golf ball according to  claim 87 , wherein the rubber composition includes 0.05 parts by weight or greater but 5.0 parts by weight or less of the organic sulfur compound (f) per 100 parts by weight of the base rubber (a). 
     
     
         90 . The golf ball according to  claim 78 , wherein
 the rubber composition includes the α,β-unsaturated carboxylic acid (b1), and   the rubber composition further includes a metal compound (e).   
     
     
         91 . The golf ball according to  claim 68 , wherein
 the mid layer is formed from a resin composition;   the inner cover is formed from a resin composition whose base resin is different from a base resin of the mid layer, and   the golf ball further comprises a reinforcing layer between the mid layer and the inner cover.

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