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Golf ball with vapor barrier layerRelated Patent Categories: Games Using Tangible Projectile, Golf, Ball, Particular Unitary Or Layered Construction, Diverse Layer Between Spherical Core And CoverGolf ball with vapor barrier layer description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20080064528, Golf ball with vapor barrier layer. Brief Patent Description - Full Patent Description - Patent Application Claims
STATEMENT OF RELATED PATENT APPLICATION [0001] This non-provisional utility patent application is a divisional of co-pending U.S. patent application Ser. No. 10/077,081, filed on Feb. 15, 2002, which is a continuation-in-part of a co-pending patent application entitled "Low Spin Soft Compression Performance Golf Ball" filed on Nov. 16, 2001 bearing Ser. No. 09/992,448. The parent applications are hereby incorporated by reference in their entirety. FIELD OF THE INVENTION [0002] The present invention relates to a novel structure for a golf ball, and more particularly to a golf ball with a thin moisture vapor barrier layer. BACKGROUND OF THE INVENTION [0003] Solid core golf balls are well known in the art. Typically, the core is made from polybutadiene rubber material, which provides the primary source of resiliency for the golf ball. U.S. Pat. Nos. 3,241,834 and 3,313,545 disclose the early work in polybutadiene chemistry. It is also known in the art that increasing the cross-link density of polybutadiene can increase the resiliency of the core. The core is typically protected by a cover from repeated impacts from golf clubs. The golf ball may comprise additional layers, which can be an outer core or an inner cover layer. One or more of these additional layers may be a wound layer of stretched elastic windings to increase the ball's resiliency. [0004] A known drawback of polybutadiene cores cross-linked with peroxide and/or zinc diacrylate is that this material is adversely affected by moisture. Water moisture vapor reduces the resiliency of the cores and degrades its properties. A polybutadiene core will absorb water and loose its resilience. Thus, these cores must be covered quickly to maintain optimum ball properties. The cover is typically made from ionomer resins, balata, and urethane, among other materials. The ionomer covers, particularly the harder ionomers, offer some protection against the penetration of water vapor. However, it is more difficult to control or impart spin to balls with hard covers. Conventional urethane covers, on the other hand, while providing better ball control, offer less resistance to water vapor than ionomer covers. [0005] Prolonged exposure to high humidity and elevated temperature may be sufficient to allow water vapor to invade the cores of some commercially available golf balls. For example at 110.degree. F. and 90% humidity for a sixty day period, significant amounts of moisture enter the cores and reduce the initial velocity of the balls by 1.8 ft/s to 4.0 ft/s or greater. The change in compression may vary from 5 PGA to about 10 PGA or greater. The absorbed water vapor also reduces the coefficient of restitution (COR) of the ball. [0006] Several prior patents have addressed the water vapor absorption problem. U.S. Pat. No. 5,820,488 discloses a golf ball with a solid inner core, an outer core and a water vapor barrier layer disposed therebetween. The water vapor barrier layer preferably has a water vapor transmission rate lower than that of the cover layer. The water vapor barrier layer can be a polyvinylidene chloride (PVDC) layer. It can also be formed by an in situ reaction between a barrier-forming material and the outer surface of the core. Alternatively, the water vapor barrier layer can be a vermiculite layer. U.S. Pat. Nos. 5,885,172 and 6,132,324 disclose, among other things, a golf ball with a polybutadiene or wound core with an ionomer resin inner cover and a relatively soft outer cover. The hard ionomer inner cover offers some resistance to water vapor penetration and the soft outer cover provides the desirable ball control. Additionally, U.S. Pat. No. 5,875,891 discloses an impermeable packaging for golf balls. The impermeable packaging acts as a moisture barrier limiting moisture absorption by golf balls during storage but not during use. [0007] It is also desirable to minimize the thickness of the water barrier layer such that other properties of the ball are unaffected. None of these references, however, discloses an efficient way to make a thin layer of water vapor barrier layer, that otherwise would not alter the performance of the ball. [0008] Hence, there remains a need for other golf balls with an improved water vapor barrier layer and improved methods for applying a water vapor barrier layer on to the core of the golf ball. SUMMARY OF THE INVENTION [0009] The present invention is directed to a golf ball comprising a core, a cover and a thin film of moisture vapor barrier with a moisture vapor transmission rate preferably lower than that of the cover to decrease the amount of moisture penetrating into the core of the golf ball. The moisture vapor barrier layer preferably comprises a copolymer of ethylene and methacrylic acid. The moisture vapor barrier layer may also comprise a terpolymer of ethylene, a softening acrylate class ester such as methyl acrylate, n-butyl-acrylate or iso-butyl-acrylate, and a carboxylic acid such as acrylic acid or methacrylic acid. The moisture vapor barrier layer may further comprise a copolymer of ethylene and acrylic acid. Alternatively, the moisture vapor barrier layer may comprise all three materials. In accordance to another aspect of the invention, the preferred copolymer of ethylene and methacrylic acid is polyethylene methacrylic acid resin. [0010] In accordance to another aspect of the invention, the preferred moisture vapor barrier materials have about 3% to about 25% of acid by weight, more preferably in the range of about 4% to 15%, and most preferably about 7% to about 11% of acid by weight. The preferred copolymers also have high melt flow index. High melt flow index of the preferred materials helps to reduce the thickness of the moisture vapor barrier layer. A readily apparent advantage of having a thin barrier layer is that it does not significantly alter the predetermined and desired properties of the designed golf ball. Preferably, the moisture vapor barrier has a thickness of about 0.020 inch to about 0.005 inch. Preferably, the moisture vapor barrier layer is made from two molded half shells that are compression-molded on to the core. [0011] In accordance to another aspect of the invention, the moisture vapor barrier can be an intermediate layer, an inner cover layer, an outer core layer, a core coating or an outer cover coating. The present invention is also directed to a golf ball having a relatively large solid polybutadiene core, a thin moisture vapor barrier layer with a thermoset urethane cover. Alternatively, the water vapor barrier layer of the present invention can be used with any known core structures and covers. BRIEF DESCRIPTION OF THE DRAWINGS [0012] In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views: [0013] FIG. 1 is a front view of a dimpled golf ball in accordance to the present invention; [0014] FIG. 2 is a cross-sectional view of the golf ball in FIG. 1 showing a solid core surrounded by a thin moisture vapor barrier layer and a cover; and [0015] FIG. 3 is a cross-sectional view of another golf ball in accordance to the present invention showing a solid core with multiple wound layers surrounded by a thin moisture vapor barrier layer. DETAILED DESCRIPTION OF THE INVENTION [0016] As shown generally in FIGS. 1 and 2, where like numbers designate like parts, reference number 10 broadly designates a golf ball in accordance to the present invention. Golf ball 10 preferably has a solid core 12, an intermediate layer 14 and a cover 16. [0017] Solid core 12 may comprise a single spherical element, or it may comprise a core spherical element with one or more intermediate layers surrounding the spherical element as shown in FIG. 3. Solid core 12 can be made from any suitable core materials including thermoset plastics, such as natural rubber, polybutadiene (PBD), polyisoprene, styrene-butadiene or styrene-propylene-diene rubber, and thermoplastics such as ionomer resins, polyamides, polyesters, or a thermoplastic elastomer. Suitable thermoplastic elastomers include Pebax.RTM., Hytrel.RTM., thermoplastic urethane, and Kraton.RTM., which are commercially available from Elf-Atochem, E.I. Du Pont de Nemours and Company, various manufacturers, and Shell Chemical Company, respectively. The core materials can also be formed from a castable material. Suitable castable materials include those comprising a urethane, polyurea, epoxy, silicone, IPN's, etc. [0018] Additionally, suitable core materials may also include a reaction injection molded polyurethane or polyurea, including those versions referred to as nucleated, where a gas, typically nitrogen, is essentially whipped into at least one component of the polyurethane, typically, the pre-polymer, prior to component injection into a closed mold where essentially full reaction takes place resulting in a cured polymer having reduced specific gravity. These materials are referred to as reaction injection molded (RIM) materials. Alternatively, core 12 may include a liquid center, such as center 12a shown in FIG. 3, and may have one or more would layers, such as intermediate layers 12b and 12c. Continue reading about Golf ball with vapor barrier layer... Full patent description for Golf ball with vapor barrier layer Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Golf ball with vapor barrier layer patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Golf ball with vapor barrier layer or other areas of interest. ### Previous Patent Application: Compositions for golf equipment Next Patent Application: Golf ball covers and mantles comprising glass particles Industry Class: Games using tangible projectile ### FreshPatents.com Support Thank you for viewing the Golf ball with vapor barrier layer patent info. 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