Method of making a golf ball product from fast-curing reaction injection molded polyurethane

• US 20020016435A1
• Filed: 01/12/2001
• Published: 02/07/2002
• Est. Priority Date: 10/21/1998
• Status: Active Grant

• Current Assignee: Wilson Sporting Goods Company (Anta International Group Holdings Ltd.)
• Original Assignee: Wilson Sporting Goods Company (Anta International Group Holdings Ltd.)
• Inventors: Matheny, Richard D., Simonutti, Frank M., Peterson, Ralph E.
• Granted Patent: US 7,067,081 B2
• Time in Patent Office: Days
• US Class Current: 528/59
• CPC Class Codes: A63B 37/0004 Surface depressions or protrusions
• CPC Class Codes: A63B 37/0023 Covers
• CPC Class Codes: A63B 37/0024 Materials other than ionomers or polyurethane
• CPC Class Codes: A63B 37/0031 Hardness
• CPC Class Codes: A63B 37/0053 Thread wound
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0065 Deflection or compression
• CPC Class Codes: A63B 37/0074 Two piece balls, i.e. cover and core
• CPC Class Codes: A63B 37/0075 Three piece balls, i.e. cover, intermediate layer and core
• CPC Class Codes: A63B 37/0076 Multi-piece balls, i.e. having two or more intermediate layers
• CPC Class Codes: A63B 37/06 Elastic cores
• CPC Class Codes: A63B 37/12 Special coverings , i.e. outer layer material balls with finger holes A63B37/0001, golf ball covers A63B37/0023
• CPC Class Codes: A63B 45/00 Apparatus or methods for manufacturing balls working of plastics or substances in a plastic state B29
• CPC Class Codes: B29B 7/7471 Mixers in which the mixing takes place at the inlet of a mould, e.g. mixing chambers situated in the mould opening
• CPC Class Codes: B29B 7/7495 for mixing rubber
• CPC Class Codes: B29B 7/7615 characterised by arrangements for controlling, measuring or regulating, e.g. for feeding or proportioning the components
• CPC Class Codes: B29B 7/826 Apparatus therefor
• CPC Class Codes: B29C 67/246 Moulding high reactive monomers or prepolymers, e.g. by reaction injection moulding [RIM], liquid injection moulding [LIM] casting monomers B29C39/006, mixing construction B29B7/74
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/6685 with compounds of group C08G18/3225 or polyamines of C08G18/38
• CPC Class Codes: C08G 2120/00 : Compositions for reaction injection moulding processes

Abstract

Golf ball products are made by reaction injection molding (RIM) fast curing thermoset polyurethane compounds. A polyurethane prepolymer and a curing agent are mixed and injected at low temperature and pressure into a closed mold where the reaction mixture gels. The mold is opened and the golf ball product is removed within 10-60 seconds after the injection step.

Claims

1. A method of forming a cover on a golf ball comprising:

positioning a spherical uncovered golf ball product in the center of a mold, the mold having a spherical mold surface,

closing the mold around the golf ball product,

mixing a polyurethane prepolymer and a curing agent to form a thermoset reaction mixture,

injecting the reaction mixture into the mold to cover the golf ball product therein,

allowing the reaction mixture to gel and form a golf ball, and

opening the mold and removing the golf ball within about 10 to 60 seconds after the injecting step.

2. The method of claim 1 in which the spherical mold surface includes projections for forming dimples in the cover of the golf ball.

3. The method of claim 1 in which said step of injecting the reaction mixture into the closed mold is performed within 0.5 to 10 seconds.

4. The method of claim 1 in which the polyurethane prepolymer has a viscosity of less than 1000 cps.

5. The method of claim 4 in which the curing agent has a viscosity of less than 2000 cps at 25°

C.

6. The method of claim 1 in which the curing agent has a viscosity of less than 2000 cps at 25°

C.

7. The method of claim 1 in which the uncovered golf ball product is a wound golf ball core.

8. The method of claim 1 in which the uncovered golf ball product is a solid core.

9. The method of claim 1 in which the uncovered golf ball product comprises a solid core and a mantle layer surrounding the core.

10. The method of claim 1 in which the uncovered golf ball product comprises a solid core and a lattice structure over the core.

11. The method of claim 1 in which the polyurethane prepolymer is selected from the class consisting of meta-toluene diisocyanate, 4,4′

-diphenylmethane diisocyante, p-mdi, 3,3′

-dimethyl-4,4-biphenyl diisocyanate, naphthalene diisocyanate, and para-phenylene diisocyanate.

12. The method of claim 1 in which the mold is opened and the golf ball is removed about 45 seconds after the injecting step.

14. The method of claim 13 in which said step of injecting the reaction mixture into the closed mold is performed within 0.5 to 10 seconds.

15. The method of claim 13 in which the mold cavity is spherical.

13. A method of forming a golf ball product comprising the steps of:

mixing a polyurethane prepolymer and a curing agent to form a thermoset reaction mixture,

injecting the reaction mixture into a closed mold having a cavity,

allowing the reaction mixture to gel and form a molded product, and

opening the mold and removing the molded product within about 10 to 60 seconds after the injecting step.