JP2008055173A - Highly neutralized acid polymer composition having low moisture vapor transmission and its use for golf ball - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide golf balls capable of preventing deterioration of characteristics and performance caused by absorbing moisture. <P>SOLUTION: At least one layer of the golf ball is manufactured using a moisture resistant composition. The moisture resistant composition comprises a highly neutralized acid polymer having a moisture vapor transmission rate of 12.5 g-mil/100 in<SP>2</SP>/day or lower. The moisture resistant composition is used for any one or more layers of a core layer, a cover layer, or an intermediate layer of a one piece, two piece, multilayer or thread-wound golf ball. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention is directed to a polymer composition comprising a highly neutralized acid polymer with a water vapor transmission rate of 12.5 g · mil / 100 in ² / day or less. The present invention is directed to use of such a composition in a golf product, in particular, a two-piece or multi-layer golf ball having an overall core diameter of 1.00 inches or more. The invention is also directed to one-piece golf balls made from such compositions.

  This application is a continuation-in-part of US patent application 11 / 270,066, filed on November 9, 2005, which is a continuation of US patent application 10 / 959,751 filed on October 6, 2004. This is a continuation-in-part application, which is a continuation-in-part of US patent application 10 / 360,233, filed February 6, 2003, now US Pat. No. 6,939,907, This is a continuation-in-part of US patent application 10 / 118,719, filed April 9, 2002 and now US Pat. No. 6,756,436, which was issued on June 26, 2001. Claims priority of filed US provisional application 60 / 301,046. These contents are incorporated herein by reference.

  Conventional golf ball core materials, such as polybutadiene rubber, tend to absorb moisture when exposed to environmental density for extended periods of time, which leads to undesirable golf ball properties and performance. As such, some golf ball structures require a water vapor barrier layer to prevent the core from being exposed to ambient humidity or water.

  Urethane is known as a material for a golf ball cover layer. However, urethane has a large water vapor transmission rate. Thus, golf balls with a urethane cover typically require a lower layer of low water vapor transmission.

  Accordingly, there remains a need in the golf industry for low water vapor transmission compositions. The present invention describes such compositions and their use in various golf ball layers.

In one embodiment, the present invention is directed to a two-piece golf ball comprised of a single layer core having a diameter of 1.58 inches or more and a polyurethane or polyurea cover having a thickness of 0.05 inches or less. . The core is made from a composition having a highly neutralized acid polymer with a compression of 50 to 85, a water vapor transmission rate (MVTR) of 12.5 g · mil / 100 in ² / day or less. .

In another embodiment, the present invention is directed to a multilayer golf ball comprising an inner core layer, an outer core layer, and a polyurethane or polyurea cover. The inner core layer has a diameter of 1.58 inches or more, a compression of 50 to 85, and a water vapor transmission rate (MVTR) of 2.5 g · mil / 100 in ² / day or less, and is highly neutralized. Prepared from a composition having an acid polymer. The thickness of the outer core layer is 0.01 inches to 0.02 inches. The cover layer thickness is 0.04 inches or less.

In yet another embodiment, the present invention is a one-piece made from a composition having a water vapor transmission rate (MVTR) of 2.5 g · mil / 100 in ² / day or less and having a highly neutralized acid polymer. It is aimed at the golf ball. The ball diameter is 1.62 inches to 1.74 inches, its compression is 50 to 85, and its COR is greater than 0.800.

Detailed Description of the Invention

  Conventional golf balls can be divided into two general classes: solids and spools. Solid golf balls include one-piece, two-piece (ie, solid core and cover), and multilayer (ie, one or more layers of solid core and / or one or more layers of cover) golf balls. A wound golf ball typically includes a solid, hollow, or liquid-filled center surrounded by a stretched elastic material and a cover.

  The golf balls of the present invention include one-piece, two-piece, multilayer and wound golf balls, which have various core structures, intermediate layers, covers and coatings. A golf ball core may be the only single layer with the entire core from the center to the outer perimeter, and may have a center and at least one outer cover layer surrounding it. The innermost part of the center and core is preferably solid, but may be hollow, liquid filled, gel filled or gas filled. The outer core layer may be a solid or a wound layer made from a stretched elastic material. Golf ball covers may include a double cover with one or more layers, eg, an inner and outer cover layer. Optionally, additional layers may be placed between the core and the cover.

  The golf ball of the present invention comprises at least one layer made from a moisture resistant composition having a highly neutralized polymer, as disclosed herein. In a preferred embodiment, the layer made from the moisture resistant composition is the core of a two-piece golf ball. In another preferred embodiment, the layer made from the moisture resistant composition is the inner core layer of a multilayer golf ball. In yet another preferred embodiment, the present invention implements a one-piece golf ball made from a moisture resistant composition.

For the purposes of this disclosure, a composition is “moisture resistant” if the water vapor transmission rate (MVTR) of the composition is 12.5 g · mil / 100 in ² / day or less. Preferably, the MVTR of the moisture resistant composition of the present invention is 8.0 g · mil / 100 in ² / day or less, or 6.5 g · mil / 100 in ² / day or less, or 5.0 g · mil / 100 in ^2. / Day or less, or 4.0 g · mil / 100 in ² / day or less, or 2.5 g · mil / 100 in ² / day or less, or 2.0 g · mil / 100 in ² / day or less. As used herein, water vapor transmission rate (MVTR) is given in g · mil / 100 in ² / day, measured at 20 ° C. and complies with ASTM F1249-99.

  The moisture resistant composition of the present invention has a highly neutralized acid polymer ("HNP") and an optional one or more additional materials including, but not limited to, organic acids and their Contains salts, fillers, additives, and non-fatty acid melt flow modifiers. In a preferred embodiment, the moisture resistant composition comprises HNP and one or more optional additional materials selected from the group consisting of organic acids and salts thereof, fillers, additives, and non-fatty acid melt flow modifiers. Consists mainly of. “Mainly composed” means here that the listed elements are basic, while a smaller amount of other elements may be present to the extent that they do not interfere with the operation of the present invention.

  As used herein, “highly neutralized” means at least 70%, preferably at least 80%, more preferably at least 90%, more preferably at least 95%, and even more preferably 100% of its acid groups. % Refers to the acid polymer after neutralization. The HNP may be neutralized with a cation, a salt of an organic acid, a suitable base of an organic acid, or a combination of two or more thereof.

The highly neutralized acid polymers of this invention are α, β-ethylene based unsaturated mono- or dicarboxylic acid homopolymer and copolymer salts, and combinations thereof. The term “copolymer” as used herein includes a polymer comprising two types of monomers, a polymer comprising three types of monomers, and a polymer comprising four or more types of monomers. Preferred α, β-ethylenically unsaturated monocarboxylic or dicarboxylic acids are (meth) acrylic acid, ethacrylic acid, maleic acid, crotonic acid, fumaric acid, itaconic acid. (Meth) acrylic acid is particularly preferred. As used herein, “(meth) acrylic acid” means methacrylic acid and / or acrylic acid. Similarly, “(meth) acrylate” means methacrylate and / or acrylate. Preferred acid polymers are C ₃ to C ₈ α, β-ethylenically unsaturated mono- or dicarboxylic acids and ethylene or C ₃ to C ₆ α-olefins, optionally including a softening monomer. A particularly preferred acid polymer is a copolymer of ethylene and (meth) acrylic acid.

When softening monomers are included, such copolymers are referred to as E / X / Y type copolymers, where E is ethylene and X is a C ₃ to C ₈ α, β-ethylenically unsaturated mono monomer. Carboxylic acid or dicarboxylic acid, Y is a softening monomer. The softening monomer is typically an alkyl (meth) acrylate, where the alkyl group contains 1 to 8 carbon atoms. Preferred E / X / Y type copolymers are those where X is (meth) acrylic acid and / or Y is (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, methyl (meth) acrylate, and ethyl It is a copolymer that is (meth) acrylate. More preferred E / X / Y type copolymers are ethylene / (meth) acrylic acid / n-butyl acrylate, ethylene / (meth) acrylic acid / methyl acrylate, and ethylene / (meth) acrylic acid / ethyl acrylate.

The amount of ethylene or C ₃ to C ₆ α-olefin in the acid copolymer is typically at least 15 wt%, preferably at least 25 wt%, more preferably at least 40 wt%, based on the total weight of the copolymer, More preferably, it is 60 wt%. The amount of C ₃ to C ₈ α, β-ethylenically unsaturated mono- or dicarboxylic acid in the acid copolymer is typically 1 wt%, or 3 wt%, based on the total weight of the copolymer Or 4 wt% or 5 wt% as a lower limit, and 20 wt%, 25 wt%, 30 wt%, or 35 wt% as an upper limit. The amount of optional softening comonomer in the acid copolymer is typically 20 wt%, or 30 wt%, with a lower limit of 0 wt%, or 5 wt%, or 10 wt%, or 15 wt%, based on the total weight of the copolymer , Or 35 wt%, or 40 wt%, or 50 wt%.

  Suitable acid polymers may be partially neutralized prior to being neutralized to 70% or higher. Suitable partially neutralized acid polymers include, but are not limited to, E.I. I. Includes Surlyn ™ ionomers commercially available from DuPont; AClyn ™ ionomers commercially available from Honeywell International; and Iotek ™ ionomers commercially available from Exxon Mobile Chemical.

  In a specific example, the acid copolymer is E.I. I. Nuclel ™ acid copolymer commercially available from DuPont (eg Nucrel 960. Ethylene / methacrylic acid copolymer), Primacor ™ polymer (eg Primacor XUS 60758.08L and XUS 60751) commercially available from Dow Chemical. 18. Ethylene / acrylic acid copolymers containing 13.5% and 15.0% acid, respectively, and these partially neutralized ionomers.

  Additional suitable acid polymers are described, for example, in US Pat. No. 6,953,820 and US Patent Application Publication 2005/0049367, the disclosures of which are hereby incorporated by reference.

  The acid polymer of this invention may be a direct copolymer in which all monomers are added simultaneously to polymerize the polymer, which is described, for example, in US Pat. No. 4,351,931, the contents of which are referred to Incorporate here. Ionomers can be made from direct copolymers as described in US Pat. No. 3,264,272, the contents of which are incorporated herein by reference. Alternatively, the acid polymer of this invention may be a graft copolymer in which monomers are grafted onto an existing polymer, as described, for example, in US Patent Application Publication 2002/0013413, the contents of which are referred to. Here.

Suitable cations for neutralizing the acid polymers of this invention include silicone, silane and silicate derivatives and complex ligands; rare earth metal ions and compounds; alkali metals, alkaline earth metals, and transition metal metals Ions and compounds; and combinations thereof. Specific cation sources include, but are not limited to, metal ions and compounds of lithium, sodium, potassium, magnesium, cesium, calcium, barium, manganese, copper, zinc, tin, rare earth metals, and combinations thereof. In a specific embodiment, the cation source is calcium metal ions and compounds, zinc metal ions and compounds, and combinations thereof. In a specific aspect of this example, the equivalent percentage of calcium and / or zinc salt in the final composition is greater than or equal to 50%, based on all of the salts in the final composition, or 60 % Or more, or 70% or more, or 80% or more, or 90% or more, and the equivalent% is determined by multiplying the mole% of the cation by the valence of the cation. In other specific examples, the cation source is selected from metal ions and compounds of lithium, sodium, potassium, magnesium, calcium, zinc, and combinations thereof. Specific potassium-based cation sources include E.I. I. Oxane ™, commercially available from DuPont. Oxane is a monopersulfate, where potassium monopersulfate is a compound of the chemical formula 2KHSO ₅ · KHSO ₄ · K ₂ SO ₄ [potassium hydrogen peroxymonosulfate sulfate (5: 3: 2: 2)]. An active ingredient present as a salt element. In another specific embodiment, the cation source is selected from lithium metal ions and compounds, zinc metal ions and compounds, and combinations thereof. Suitable cation sources also include mixtures of lithium and / or zinc with other cations. Other cations suitable for mixing with lithium and / or zinc to produce HNP include, but are not limited to, “less hydrophilic” cations disclosed in US 2006/0106175; Cations such as those disclosed in US Pat. Nos. 6,756,436 and 6,824,477; and cations disclosed in US Patent Application Publication No. 2005/026740. These contents are incorporated herein by reference. In a specific aspect of this example, the percentage of lithium and / or zinc salts in the composition is 50% or more, or 55% or more, or 60, based on all of the salts in the composition. % Or more, or 65% or more, or 70% or more, or 80% or more, or 90% or more, or 95% or more, or 100%. The amount of cation source used can be readily determined based on the level of neutralization desired.

  The moisture resistant composition of the present invention optionally has one or more organic acids and / or salts thereof. Suitable organic acids are aliphatic organic acids, aromatic organic acids, saturated monofunctional organic acids, unsaturated monofunctional organic acids, multiunsaturated monofunctional organic acids, and dimer derivatives thereof. Specifically, aliphatic and monofunctional organic acids are suitable, preferably those having less than 36 carbon atoms. Specific examples of suitable organic acids include, but are not limited to, caproic acid, caprylic acid, capric acid, lauric acid, stearic acid, behenic acid, erucic acid, oleic acid, linoleic acid, myristic acid, benzoic acid, Including palmitic acid, phenylacetic acid, naphthalenic acid, and dimer derivatives thereof. Specific suitable organic acid salts include those produced by a cation source selected from barium, lithium, sodium, zinc, bismuth, potassium, strontium, magnesium, calcium, and combinations thereof. Suitable organic acids are described in more detail, for example, in US Pat. No. 6,756,436, the contents of which are hereby incorporated by reference.

  The moisture resistant composition of the present invention optionally includes one or more additives and / or one or more fillers. Suitable additives include, but are not limited to, swelling and foaming agents, optical brighteners, colorants, fluorescent agents, whitening agents, UV absorbers, light stabilizers, antifoaming agents, processing aids, mica , Talc, nanofillers, antioxidants, stabilizers, softeners, perfume ingredients, plasticizers, impact modifiers, acid copolymer waxes, and surfactants. Suitable fillers include but are not limited to inorganic fillers such as zinc oxide, titanium dioxide, tin oxide, calcium oxide, magnesium oxide, barium sulfate, zinc sulfate, calcium carbonate, zinc carbonate, barium carbonate, mica, talc, Clay, silica, lead silicate, etc .; high specific gravity metal powder fillers, such as tungsten powder, molybdenum powder, etc .; reground or ground and recycled core material; and nanofillers. The filler material may be a bifunctional filler such as zinc oxide (which can be used as a filler / acid scavenger) and titanium dioxide (which is used as a filler / lightening agent and used). In addition, examples of suitable fillers and additives include, but are not limited to, those disclosed in US Patent Application Publication 2003/0225197, the contents of which are hereby incorporated by reference.

  The moisture resistant composition of this invention optionally includes one or more non-fatty acid melt flow modifiers. Suitable non-fatty acid melt flow modifiers include polyamides, polyesters, polyacrylates, polyurethanes, polyethers, thermoplastic polyureas, polyhydric alcohols, and combinations thereof. Additional non-fatty acid melt flow modifiers suitable for use in the compositions of this invention include those described in US Patent Application Publication 2006/0063893 and US Patent Application 11/216726, the disclosure of which is Incorporated herein by reference.

The moisture resistant composition of this invention can optionally be prepared by blending HNP with one or more additional polymers, such as thermoplastic polymers and elastomers. Examples of thermoplastic polymers suitable for blending with the HNP of this invention include, but are not limited to, polyolefins, polyamides, polyesters, polyethers, polycarbonates, polysulfones, polyacetals, polylactones, acrylonitrile-butadiene-styrene resins, polyphenylene oxides. , Polyphenylene sulfide, styrene-acrylonitrile resin, styrene maleic anhydride, polyimide, aromatic polyketone, ionomer and ionomer precursor, acid copolymer, conventional HNP, polyurethane, grafted or ungrafted metallocene catalyst polymer, single site catalyst polymerization Polymers, highly crystalline acid polymers, cationic ionomers, and combinations thereof. Specific polyolefins suitable for blending one or more linear or branched or cyclic _C 2 _{-C 40} olefin, specifically, of one or more _C 2 _{-C 40 olefins,} the C 3 _{-C 20} It is a polymer containing ethylene or propylene copolymerized with an α-olefin or a C ₃ -C ₁₀ α-olefin. Specific conventional HNPs suitable for blending are disclosed in, but not limited to, US Pat. Nos. 6,756,436, 6,894,098, and 6,953,820. One or more HNPs, the disclosures of which are incorporated herein by reference. Examples of elastomers suitable for blending with the polymers of this invention include, but are not limited to, all natural and synthetic rubbers, ethylene propylene rubber ("EPR"), ethylene propylene diene rubber ("EPDM"), Styrene block copolymer rubber (eg, SI, SIS, SB, SBS, SIBS, etc., “S” is styrene, “I” is isobutylene, “B” is butadiene), butyl rubber, halobutyl rubber, isobutylene and para-alkyl Copolymers of styrene, halogenated copolymers of isobutylene and para-alkyl styrene, natural rubber, polyisoprene, copolymers of butadiene with acrylonitrile, polychloroprene, alkyl acrylate rubber, isoprene chloride rubber, acrylonitrile isoprene chloride Beam, and a polybutadiene rubber (cis and trans). Still other suitable blend polymers include those disclosed in U.S. Pat. No. 5,981,658, e.g., column 14, lines 30-56, and U.S. Patent Application Publication No. 2005/026740. These disclosures are incorporated herein. The blends described herein can be made by combining the reactor in series with the reactor blend by blending after the reactor, and by producing multiple types of polymers using multiple catalysts in the same reactor, Can be manufactured. The polymer may be mixed before entering the extruder or may be mixed in the extruder.

  The present invention is not limited to a specific method or apparatus for producing a moisture resistant composition. In the preferred embodiment, it is prepared by the following process. An acid polymer, preferably ethylene / (meth) acrylic acid, at least one organic acid or salt thereof, and optional additional materials such as additives, fillers, and non-fatty acid melt flow modifiers are melt extruder For example, to a single or twin screw extruder. An appropriate amount of one cation source is added to the molten acid polymer to neutralize at least 70% of all acid groups present, including acid groups of the acid polymer and acid groups of the optional organic acid. Of all the acid groups present, preferably at least 80%, more preferably at least 90%, even more preferably at least 95%, more preferably at least 100% are neutralized. The acid polymer may be partially neutralized prior to contact with a cation source selected from calcium, magnesium and zinc metal salts and compounds. The acid polymer / cation mixture is intensively mixed before it is extruded as a strand from the mold head. In a specific aspect of this example, the ethylene / (meth) acrylic acid copolymer is an E.I. I. Nuclel ™ acid copolymers commercially available from DuPont (eg, Nuclel 960. Ethylene / methacrylic acid copolymer) and Primacor ™ polymers (eg, Primacor XUS 60758.08L and XUS 60751) commercially available from Dow Chemical. 18. Ethylene / acrylic acid copolymer containing 13.5% and 15.0% acid respectively).

  Further, suitable moisture resistant compositions include, but are not limited to, compositions containing HNPs neutralized by less hydrophilic cations disclosed in US Patent Application Publication 2006/0106175, the disclosure of which The contents are incorporated herein by reference.

  In order to be processable, the moisture resistant composition of the present invention has a melt flow index of at least 0.5 g / 10 min (190 ° C., 2, 16 kg). Preferably, the melt flow index of the moisture resistant composition is at least 0.8 g / 10 min, alternatively a lower limit of 0.8 g / 10 min or 1.0 g / 10 min and 4.0 g / 10 min or 5. It is in a range having an upper limit of 0 g / 10 minutes. For the purposes of this disclosure, the melt flow index is measured according to ASTM D1238.

The moisture resistant composition of the present invention can be used for various applications. For example, HMP-containing moisture resistant compositions are suitable for use in golf equipment. Golf equipment includes, but is not limited to, golf balls, golf shoes, and golf clubs. The moisture resistant composition of the present invention is particularly suitable for use in one-piece golf balls and two-piece and multi-layer golf balls having an overall core diameter of 1.00 inches or greater.

  The golf ball of the present invention may be a spool, a one-piece, a two-piece, or a multi-layer golf ball. However, at least one layer is made from a moisture-resistant composition containing the above-mentioned HNP. In a golf ball having two or more layers having a moisture resistant composition, the moisture resistant composition of one layer may be the same as or different from the moisture resistant composition of the other layer. The layer having the moisture resistant composition may be any one or more of a core layer (eg, center or outer core layer), an intermediate layer, or a cover layer. The composition of this invention may be foamed or filled with a density adjusting material to achieve the desired modified moment of inertia.

  The coefficient of restitution (COR) of golf balls of this invention is generally at least 0.790, preferably at least 0.800, more preferably at least 0.805, even more preferably 0.810, and the compression is 75 to 110, preferably 90 to 100.

  The present invention is not limited to a specific method for producing a golf ball layer. Note that the layer may be manufactured by any suitable technique including injection molding, compression molding, molding, and reactive injection molding. Preferably, the thermosetting cover material is manufactured into a golf ball cover by a molding or reactive injection molding technique, and the thermoplastic cover material is manufactured into a golf ball cover by a compression or injection molding technique.

In accordance with this invention, it has been found that the moisture resistant composition disclosed herein is particularly suitable for one or more of the following golf ball structures.
(1) One-piece golf ball.
(2) As a core layer of a two-piece golf ball.
(3) As an inner core layer of a multilayer golf ball.

In a preferred embodiment, the present invention implements a one-piece golf ball made from the moisture resistant composition described herein. The MVTR of the moisture resistant composition is 12.5 g · mil / 100 in ² / day or less, preferably 8.0 g · mil / 100 in ² / day or less, more preferably 6.5 g · mil / 100 in ² / day or less, More preferably, it is 5.0 g · mil / 100 in ² / day or less, more preferably 4.0 g · mil / 100 in ² / day or less, more preferably 2.5 g · mil / 100 in ² / day or less, and most preferably Is 2.0 g · mil / 100 in ² / day or less. The golf ball has a diameter of 1.62 inches to 1.74 inches, preferably 1.66 inches to 1.70 inches, and more preferably 1.68 inches. Preferably, the golf ball has a compression of 50 to 85 and / or a coefficient of restitution (“COR”) of 0.800 or greater.

In another preferred embodiment, the present invention provides a two-piece golf ball having a single layer core and a single layer cover, the cover being manufactured from the moisture resistant composition described herein. The MVTR of the moisture resistant composition is 12.5 g · mil / 100 in ² / day or less, preferably 8.0 g · mil / 100 in ² / day or less, more preferably 6.5 g · mil / 100 in ² / day or less, More preferably, it is 5.0 g · mil / 100 in ² / day or less, more preferably 4.0 g · mil / 100 in ² / day or less, more preferably 2.5 g · mil / 100 in ² / day or less, and most preferably Is 2.0 g · mil / 100 in ² / day or less. Preferably, at least 80%, or at least 90%, or at least 95%, or 100% of all acid functionalities present in the moisture resistant composition are neutralized. The diameter of the core is 1.58 inches or more, preferably 1.62 inches. Preferably, the compression of the core is 50 to 85 and / or the COR of the core is 0.800 or higher. Preferably, the specific gravity of the core is 1.13. The cover thickness is 0.05 inches or less, preferably 0.03 inches. Suitable cover materials include, but are not limited to, thermosets and thermoplastic polyurethanes, thermosets and thermoplastic polyureas, thermoplastic rubbers, polyether-amides, polyether-esters, polyether-ureas, styrene / Includes butadiene / styrene block copolymers, ionomers, polyethylene, synthetic and natural rubber, and blends thereof. Thermoplastic polyurethane is a preferred cover material.

In another preferred embodiment, the present invention includes a two-piece golf ball having an inner core layer, an outer core layer, and a cover, wherein the inner core layer is preferably made from the moisture resistant composition described herein. Is realized. The MVTR of the moisture resistant composition is 12.5 g · mil / 100 in ² / day or less, preferably 8.0 g · mil / 100 in ² / day or less, more preferably 6.5 g · mil / 100 in ² / day or less, More preferably, it is 5.0 g · mil / 100 in ² / day or less, more preferably 4.0 g · mil / 100 in ² / day or less, more preferably 2.5 g · mil / 100 in ² / day or less, and most preferably Is 2.0 g · mil / 100 in ² / day or less. Preferably, at least 80%, or at least 90%, or at least 95%, or 100% of all acid functionalities present in the moisture resistant composition are neutralized. The inner core layer has a diameter of 1.58 inches or more, preferably 1.62 inches. Preferably, the compression of the inner core layer is from 50 to 85 and / or the COR of the core is 0.800 or higher. The thickness of the outer core layer is 0.01 inches to 0.02 inches, preferably 0.015 inches. Preferably, the specific gravity of the inner core layer is 1.13 and the specific gravity of the outer core layer is at least 2.5 times the specific gravity of the inner core layer. The cover thickness is 0.04 inches or less, and preferably 0.015 inches. Suitable cover materials include materials for the two-piece golf ball of the present invention. Thermoplastic polyurethane is a preferred cover material. Suitable outer core materials include non-natural and non-natural rubbers, polyurethanes, polyureas, epoxies, polyesters; thermoplastic polymers incorporating bulk fillers, fibers, flakes or particles; reactive coatings or molding materials such as Epoxy, styrenated polyester, polyurethane or polyurea, liquid PBR, silicone, silicate gel, agar gel; and non-reactive coating and molding materials such as melt or floatable polymers, dissolved or dispersed in volatile solvents Incorporated or filled compositions selected from various powders. Suitable outer core materials are disclosed in “thin dense layers” disclosed in US Pat. Nos. 6,494,795; US Pat. Nos. 6,149,535 and 6,152,834. And embedded thin film films or “prepregs” or “densified embedded films” as described in US Pat. No. 6,010,411. The disclosures of which are incorporated herein by reference.

  The golf ball of the present invention may comprise at least one layer manufactured from a composition other than the moisture resistant composition described above. Suitable materials for the golf ball core, intermediate layer and cover layer of this invention include, but are not limited to, polyethylene including, for example, low density polyethylene, linear low density polyethylene, and high density polyethylene; polypropylene; rubber reinforced olefin polymers; Ether-esters; copolyether-amides; polycarbonates; acid copolymers that do not form part of an ionomeric copolymer; plastomers; flexomers: vinyl resins, eg, those made by copolymerizing vinyl chloride with vinyl cetate, acrylic esters, or vinylidene Styrene / butadiene / styrene block copolymer; styrene / ethylene-butylene / styrene block copolymer; dynamically vulcanized elastomer; ethylene vinyl acetate; Tylene methacrylate and ethylene ethacrylate; ethylene methacrylic acid, ethylene acrylic acid, and propylene acrylic acid; polyvinyl chloride resins; copolymers and homopolymers made using metallocene or other single site catalysts; polyamides, amide-ester elastomers, And ionomer and polyamide graft copolymers (including, for example, Pebax ™ thermoplastic polyether block amide, commercially available from Arkema); polyphenylene oxide resins, such as commercially available from General Electric NORYL ™; cross-linked trans polyisoprene blends; polyurethanes; polyureas; polyester-based thermoplastic elastomers such as E.I. I. Hytel (TM), commercially available from DuPont de Nemours and Company, and LOMOD (TM), commercially available from General Electric; polyurethane-based thermoplastic elastomers, such as commercially available from BASF Elastollan ™; synthetic or natural rubber; partially or fully neutralized ionomers; and combinations thereof. Suitable golf ball materials and structures include, but are not limited to, those disclosed in US Pat. Nos. 6,117,025, 6,767,940, and 6,969,630, These contents may be referred to and incorporated herein.

  For the purposes of this invention, compression is measured using an Atti compression test apparatus according to known procedures, where a piston is used to press the ball against the spring. The displacement of the piston is fixed and the displacement of the spring is measured. The measurement of spring deflection does not start at the point of contact of the ball. Rather, there is approximately a first 1.25 mm (0.25 inch) spring offset offset. A very stiff core will not deflect the spring more than 1.25 mm and zero compression is measured. The Atti compression tester is designed to measure objects with a diameter of 42.7 mm (1.68 inches). Therefore, smaller objects such as golf ball cores must fill the gaps to a height of 42.7 mm to obtain accurate measurements.

For the purposes of this invention, the COR is determined according to known procedures, in which a golf ball or golf ball subassembly (eg, a golf ball core) is moved from an air gun to a predetermined velocity (38.1 m / s for purposes of this invention). (125 ft / s)). A plurality of ballistic light screens are placed between the air cannon and the steel plate to measure the velocity of the ball. As the ball moves to the steel plate, the ball activates each light screen and measures the time on each light screen. Thereby, an incident transition time proportional to the incident speed of the ball is obtained. The ball collides with the steel plate and rebounds through multiple light screens, measuring the time interval it takes to move between the light screens. Thereby, the jumping transition time proportional to the jumping speed of the ball is obtained. COR is calculated as the ratio of the pop-out transition time interval to the incident transition time interval, COR = T _out / T _in .

  Note that where a lower numerical limit and an upper numerical limit are indicated here, any combination of these values may be employed.

  All patents, publications, test procedures and other reference materials cited herein, including prior art references, are hereby fully incorporated by reference to the extent not inconsistent with the present invention.

  Although exemplary embodiments of the present invention have been described in detail, it should be noted that various modifications and other embodiments can be readily devised by those skilled in the art without departing from the spirit of the invention. Accordingly, the claims are not to be limited to the examples and description shown herein, but rather, the claims are to be understood as encompassing all the novel features that are patentable in the invention. It should be noted that it includes all features that are considered equivalent by those skilled in the art to which this invention pertains.

Claims (9)

A single layer core made from a moisture resistant composition having a diameter of at least 4.01 cm (1.58 inches) and a compression of 50 to 85, wherein the moisture resistant composition is 12.5 g · mil / 100 in. One or more optional additions selected from the group consisting of highly neutralized acid polymers having a water vapor transmission rate (MVTR) of ² / day or less and fillers, additives, and melt flow modifiers Composed mainly of traditional materials,
A two-piece golf ball having a polyurethane or polyurea cover having a thickness of 0.05 inches or less.   The golf ball of claim 1, wherein the core has a diameter of 1.62 inches and the cover has a thickness of 0.03 inches.   The golf ball according to claim 1, wherein at least 80% of the acid groups in the moisture-resistant composition are neutralized with a salt.   The golf ball according to claim 3, wherein at least 50% of the acid groups in the moisture-resistant composition are neutralized with a salt having a counter ion selected from the group consisting of Zn, Ca, and combinations thereof. The golf ball according to claim 1, wherein the moisture resistant composition has an MVTR of 4 g · mil / 100 in ² / day or less. The COR of the core is 0.800 or more, the MVTR of the moisture resistant composition is 2.5 g · mil / 100 in ² / day or less, and 100% of all the acid functionalities of the moisture resistant composition are medium. The golf ball of claim 1 to be summed. An inner core layer having a diameter of 4.01 cm (1.58 inches) or more, a compression of 50 to 85, and made from a moisture resistant composition, wherein the moisture resistant composition is 2.5 g · mil / 100 in ^2. Selected from the group consisting of a highly neutralized acid polymer with a water vapor transmission rate (MVTR) / day or less and organic acids and their salts, fillers, additives, and non-fatty acid melt flow modifiers Consisting primarily of optional one or more additional materials;
An outer core layer having a thickness of 0.01 inch to 0.02 inch;
A multilayer golf ball comprising a polyurethane or polyurea cover having a thickness of 0.002 inches or less.   The golf ball according to claim 7, wherein the specific gravity of the outer core layer is at least 2.5 times the specific gravity of the inner core. Made from a moisture resistant composition with a diameter of between 4.12 cm (1.62 inches) to 4.42 cm (1.74 inches), a compression of 50 to 85, a COR of 0.800 or greater, and the above moisture resistant composition. The product has a water vapor transmission rate (MVTR) of 2.5 g · mil / 100 in ² / day or less and is selected from the group consisting of highly neutralized acid polymers, fillers, additives, and melt flow modifiers One-piece golf ball characterized in that it is mainly composed of one or more optional additional materials.