Golf equipment, or a portion thereof, with improved abrasion resistance is obtained by applying a coating comprising hard filler particles, a coupling agent and a polymer precursor preferably comprising a plurality of reactive monomers and/or oligomers. Colloidal silica may be used as the filler, silanes of the form Yxe2x80x94(CH2)nSiX3, wherein Y is an organofunctional group providing the bonding with the polymer matrix attached to the central silicon atom via the stable (CH2)n carbon chain and X represents the silicon-functional or alkoxy group that hydrolyzes and subsequently reacts with the active sites on inorganic surfaces. The coating may be hardened by curing with ultraviolet radiation or solvent evaporation and crosslinking.

The present invention relates to a coating for golf equipment that is a two component curable composition that contains colloidal silica, reactive coupling agents, and a solvent system. Such a curable composition is particularly useful in golf equipment coating compositions that are curable at ambient, thermal, ultraviolet, electron beam, or some combination of the listed conditions. These compositions have been adapted for application to golf equipment, in particular golf balls, for improving the abrasion resistance of the so-coated surfaces.
Materials used in forming golf ball covers, such as balata, SURLYN(copyright), and urethane elastomer suffer from abrasion and shear produced by multiple oblique hits by a golf club. It is known to apply coatings to the surface of golf balls to increase the abrasion resistance of the coated surfaces but the results achieved with the use of such coatings has not entirely met the requirements of the golfing public. Thus, there is a need to improve the abrasion resistance of such coating materials.
More than five hundred million golf balls are produced each year. Most of these balls have covers molded from the ionomeric resin SURLYN(copyright) or its counterparts and, to a lesser extent, balata (i.e., trans polyisoprene). Conventionally, coating compositions are applied to the ball surface to protect the ball, the identifying indicia and any paint layers, and to add a pleasing appearance to the ball due to their high gloss. Typically such coatings comprise a clear primer coat and a clear top coat, although for certain applications a single top coat may suffice. The primer layer is applied to promote adhesion or to smooth the surface roughness before the top coat(s) are added to the golf ball. Coating compositions are generally free of pigmentation and are water white. However, they may contain small amounts of dye, pigment, and optical brighteners so long as they still allow for a bright ball cover. In golf balls of the type described above, the various identifying indicia may be applied either directly upon or alternatively upon the cover, the primer coat or the top coat.
Coating composition materials are well known in the art. Generally, they consist of urethanes, urethane hybrids, polyesters and acrylics. In particular, a cured polyurethane top coat is most widely used as a protective coating composition material. Polyurethane systems are typically either xe2x80x9cone componentxe2x80x9d or xe2x80x9ctwo componentxe2x80x9d systems. One component systems are generally made up of minute polymeric particles (reacted or partially reacted) which are suspended or dispersed in one or more solvents.
Curing and subsequent formation of a coating results from the evaporation of the solvent and/or the addition of a curing agent. The two component systems rely on keeping he primary reactants separate from one another until the time for forming the coating. Upon the addition of the reactants to one another, polymerization occurs. In forming such a coating, the reaction may be accompanied or followed by evaporation of the solvent. Typical two component polyurethane systems include separate packages of polyol and diisocyanate, which are mixed together to yield a thermoset coating composition. In some cases, more than one curing mechanism may be used to cure the coating system, i.e. evaporation of solvent via ambient air in addition to the coating be subjected to ultraviolet light. Polyurethane systems may be classified as either water-based or nonaqueous solvent-based systems. The following references are examples of polyurethane coating systems known in the golf ball art.
U.S. Pat. No. 3,784,209 discloses that golf balls can be painted via use of enamel, polyurethane, epoxy, acrylic or vinyl based coatings. However, system specific compositions and teaching of novel compositions are not provided.
U.S. Pat. No. 5,409,233 discloses a clear coating for a golf ball which comprises about 35-90% by weight of a polymer including a hydroxyl-containing resin an isocyanate such that an equivalent weight ratio of xe2x80x94NCO to xe2x80x94OH is in the range of 0.9 to 1.4, as well as up to 65% by weight of a solvent system including methylamyl ketone (MAK). This particular solvent system allows for an increased solids content (more than 45%) than that of conventional coatings (about 35%).
International Publication No. WO 92/19656 discloses a coating composition for golf balls which is a mixture of a hard acrylic polymer having a functionality reactive with an isocyanate and isocyanate-reactive modifiers, reacted together in a solvent with an isocyanate such as polyisocyanate. Golf balls employing such coatings are said to have improved hardness and flexibility.
U.S. Pat. No. 5,000,458 is directed towards a golf ball with an optical brightener incorporated in the primer coat, wherein the primer coat has an optical brightener admixed there such that the optical brightener constitutes about 0.45 to 2.7% by weight of the solids content of the primer coat.
U.S. Pat. No. 5,300,325 relates to a primer which improves the adhesion of a polyurethane top coat to a thermoplastic ionomer resin-based composition. The primer composition consists essentially of from about 90% by weight to about 96% by weight of a water-borne dispersion of acrylic resin or polyurethane resin or both and from about 4% to about 10% by weight of a polyfunctional aziridine.
U.S. Pat. No. 5,459,220 is directed towards a golf ball having an improved urethane top coat. The top coat is formed from a two-part polyurethane system wherein the first part contains a hydroxyl functional polyol and the second part contains a diisocyanate crosslinking agent selected from the group consisting of biurets of hexamethylene diisocyanate and isocyanurate trimers of hexamethylene diisocyanate. Top coats containing such crosslinking agents are said to exhibit superior adhesion and abrasion resistance, and superior non-yellowing properties upon exposure to U.V. radiation as compared to conventional top coats.
U.S. Pat. No. 5,461,109 discloses a water-reducible, two component polyurethane coating composition, wherein the first component comprises a compound having a hydroxyl functionality, an organic solvent, an optical brightener and water, and the second component comprises an aliphatic polyisocyanate and an organic solvent. The advantage of these water-reducible coating compositions is that they avoid the foaming problem generally associated with two component polyurethane systems. Additionally, these coating compositions may be applied to a SURLYN(copyright) covered ball without the need for a primer coat or an adhesion promoting layer.
U.S. Pat. No. 4,486,319 teaches that the lower the Melt Flow Index of the coating polymer, the higher the abrasion resistance of the composition.
U.K. Patent No. GB 2,285,401 A discloses a coated golf ball having a constant film thickness at the dimple edge using a urethane and/or an epoxy based paint containing one or more of the following silica, clay and calcium carbonate. Here, the silica and other noted materials are used to exhibit high viscosity at low shear forces, so the paint does not creep from the dimples. The silica used is solid and is described as a filler with levels not exceeding 3% by weight of paint resin. Use of a coupling agent is also described here, but is used to keep the silica and other noted materials from sedimentation.
U.K. Patent No. GB 2,177,093 A discloses an ultra-violet coating composition that comprises of a multifunctional epoxy oligomer and a finely powdered inorganic filler (such as silica) that has been surface treated via the hydrolysis with an epoxy-containing silane coupling agent.
U.S. Pat. Nos. 5,368,941, 5,260,350, and 4,478,876 disclose ultra-violet curing systems to cure aminofunctional or acryloxy functional silanes and colloidal silica to produce abrasion resistant hardcoats for use on glass, plastic, and polycarbonate substrates. While the coatings are abrasion resistant, they are intended for use when deformation is not critical.
U.S. Pat. No. 5,853,809 and EP 0,832,947 disclose a scratch resistant automotive coating that makes use of a resin system combined with colloidal silica and a coupling agent. More specifically, the patent teaches use of carbamate functional coupling agents and prefers reactions with aminoplast resins. While other systems are discussed, the curing range for all disclosed systems is between 93xc2x0 C. and 177xc2x0 C. Such temperatures would undesirably destroy a conventional golf ball cover during the coating process.
While some conventional coating systems, including a few of those described above, do impart a measure of abrasion and impact resistance, a continuing need exists for improved coatings capable of providing enhanced abrasion resistance and adherence to balls without negatively affecting the performance of the coated object.
The present invention is directed to an abrasion-resistant coating for golf equipment, or a portion thereof, in particular to a golf ball having a cover and a core.
In one embodiment, the abrasion-resistant coating includes: a reactive component A including a polyol or a mixture of polyol components and polymer precursors; a reactive component B comprising an isocyanate component which includes at least one of diphenylmethane 4,4xe2x80x2-diisocyanate, toluene diisocyanate, isophorone diisocyanate, or hexamethylene diisocyanate, and optionally an aziridine; colloidal silica present in an amount sufficient to increase the abrasion resistance of the coating; a coupling agent present in an amount sufficient to react with the colloidal silica; and a solvent, or a reaction product thereof. The reactive component A preferably includes at least one of a hydroxyl functional acrylic, hydroxyl functional polyester, hydroxyl functional polyester, hydroxyl functional polyether, polyamine, polyamide, alkyd, or epoxy resin with secondary hydroxyl group(s), phenolic resin, or hydroxyl functional resin. The coating can further include an optical brightener and/or at least one of a pigment, dye, tint, or filler, each in an amount sufficient to provide the coating with visible pigmentation. In one embodiment, substantially all of the coating remains adhered to the golf ball after repeated hits with a golf club. In another embodiment, the coating is cured by solvent evaporation from a water-based or organic-based solvent system.
In a second embodiment, the abrasion-resistant coating includes: an acid functional resin group comprising at least one of epoxy resins, acrylic resins, polyesters, polyethers, anhydrides, or polyamides; colloidal silica present in an amount sufficient to increase the abrasion resistance of the coating; a coupling agent present in an amount sufficient to react with the colloidal silica; and a solvent, or a reaction product thereof.
In a third embodiment, the coating includes: an unsaturated resin comprising at least one of a unsaturated carboxylic acid resin or an unsaturated vinyl resin; colloidal silica present in an amount sufficient to increase the abrasion resistance of the coating; a coupling agent present in an amount sufficient to react with the colloidal silica; and a solvent, or a reaction product thereof. Preferably, the coating further includes at least one free-radical initiator that preferably includes at least one thermal initiator or photoinitator. In one embodiment, each free-radical initiator includes at least one peroxide, azo compound, benzophenone, or combination thereof. The coating is preferably cured by at least one of heat or ultraviolet radiation.
In a fourth embodiment, the coating includes a reactive component A including a polyol or a mixture of polyol components and polymer precursors; a reactive component B comprising an isocyanate component which includes at least one of diphenylmethane 4,4xe2x80x2-diisocyanate, toluene diisocyanate, isophorone diisocyanate, or hexamethylene diisocyanate, and optionally an aziridine; an unsaturated resin including at least one of a unsaturated carboxylic acid resin or an unsaturated vinyl resin; colloidal silica present in an amount sufficient to increase the abrasion resistance of the coating a coupling agent present in an amount sufficient to react with the colloidal silica; and a solvent, or a reaction product thereof. Preferably, the coating includes at least one of thermal initiator or photoinitiator and is cured by at least one of heat, electron beam radiation, or ultraviolet radiation.
The invention is also directed to a method for reducing the amount of abrasion sustained by golf equipment, or a portion thereof, in particular to a golf ball cover during play, through application to the cover of a coating containing a colloidal silica and a coupling agent that, collectively, do not change the flexibility and/or the crosslink density of the coating. Specifically, golf equipment, or a portion thereof, in particular a molded golf ball, is covered with a coating including colloidal silica, a coupling agent, and reactive components A and B along with a solvent system. This permits the formation of a relatively soft coating having increased durability. In one embodiment, the curing includes solvent evaporation from a water-based or organic based solvent system. In another embodiment, the curing includes heat or ultraviolet radiation. In one embodiment, the curing occurs at a temperature of about 32xc2x0 F. to 132xc2x0 F.
In each of these embodiments, the colloidal silica is typically present in an amount of at least about 5 weight percent.
The term xe2x80x9cabout,xe2x80x9d as used herein, should generally be understood to refer to both numbers in a range of numerals. Moreover, all numerical ranges herein should be understood to include each whole integer within the range.
As used herein, the term xe2x80x9cgolf equipmentxe2x80x9d is meant to refer broadly to any type of equipment used in connection with golf, including, but not limited to, golf balls, golf clubs (i.e., putters, drivers, and wedges) and club attachments, additions, or modifications, such as striking face inserts; golf club components (i.e., shafts, hosels, and grips); golf club vibration damping devices; golf gloves and portions thereof, such as glove liners, securing methods, patches, and reinforcements; golf shoes and associated components (i.e., soles, footbeds and spike socket spines, heel counters, toe xe2x80x9cpuffs,xe2x80x9d uppers, midsoles, outsoles, liners, and plastic golf spikes); golf bags and their associated framework, support legs, and stands; and any portion of the above items.
As used herein in reference to a golf ball, the term xe2x80x9ccorexe2x80x9d represents the center and optional additional layer(s), such as an intermediate layer, which layer(s) is(are) disposed between the center and the cover of the golf ball.
As used herein, the term xe2x80x9cpolyol,xe2x80x9d refers to a compound containing at least 2 hydroxyl groups, regardless of its molecular weight. The term xe2x80x9cpolyamine,xe2x80x9d as used herein, refers to a compound containing at least 2 primary or secondary amine groups, regardless of molecular weight.
The present invention relates to golf equipment, or a portion thereof having improved abrasion resistance obtained by incorporating colloidal silica within the coating material. A coupling agent is used to promote adhesion and dispersion and to form a matrix with the colloidal silica and the coating components, physically forming an integral part of the coating and increasing abrasion resistance without negatively affecting overall hardness.
The present invention also relates to a method of forming a coating composition which, upon application to a golf ball, improves the durability of such coated balls by enhancing their resistance to abrasion. The composition of the present invention includes reactive components A and B, a xe2x80x9chardxe2x80x9d particle component, a coupling agent, and a solvent system, and optionally filler(s), additive(s), and the like.
In one embodiment, a one component system including an acid functional resin is used in place of reactive components A and B. Acid functional resins used in this invention include, but are not limited to, epoxy resins, acrylic resins, polyesters, polyethers, anhydrides, polyamides, and mixtures thereof.
In another embodiment, a one component system including an unsaturated resin is used in place of reactive components A and B. Unsaturated resins used in this invention preferably include, but are not limited to, radically catalyzed materials containing unsaturated resins, such as unsaturated carboxylic acid resins, unsaturated vinyl resins, or mixtures thereof.
Any suitable free-radical initiator can be included with the unsaturated resin to facilitate the cure thereof. Preferably, the initiator includes at least one peroxide, ultraviolet photoinitiator, visible-light photoinitiator, or a combination thereof. One particularly suitable class of ultraviolet photoinitiators includes benzophenones. The peroxide is preferably an organic peroxide. Exemplary initiators include di-t-amyl peroxide; di(2-t-butyl-peroxyisopropyl)benzene peroxide; 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, dicumyl peroxide; di-t-butyl peroxide; 2,5-di-(t-butylperoxy)-2,5-dimethyl hexane; n-butyl-4,4-bis(t-butylperoxy)valerate; lauryl peroxide; benzoyl peroxide; t-butyl hydroperoxide; and the like, and any mixture thereof. The peroxide, when included, is typically present in an amount greater than about 0.1 parts per hundred of the total resilient polymer component, preferably about 0.1 to 15 parts per hundred of the resilient polymer component, and more preferably about 0.2 to 5 parts per hundred of the total resilient polymer component. The free-radical initiator may also be one or more sources such as an electron beam, UV or gamma radiation, x-rays, or any other high energy radiation source capable of generating free radicals. These materials can include ultraviolet and/or thermal curable materials.
Reactive component A typically includes at least one hydroxyfunctional polyol. The polyols of this invention can include one or more materials that contains a reactive hydrogen atom and that would react with the isocyanate or isocyanurate group. These materials include hydroxyl functional acrylics, hydroxyl functional polyesters, acid functional resins, hydroxy functional polyethers, polyamines, polyamides, short oil alkyds, caster oil, epoxy resins with secondary hydroxyl groups, phenolic resins, and hydroxyl functional vinyl resins, and mixtures thereof. If necessary, the vinyl resins may be used to promote adhesion. Reactive component A can include a mixture of polyols and polymer precursors. The polymer precursors can be radiation curable monomers or oligomers curable by a method including ultraviolet radiation, electron beam radiation, or heat, or a combination thereof. The reactive component A can also include pigments, tints, dyes, and fillers in an amount to provide visible coloration in the coating.
The preferred coatings are based on monomers and oligomers of acrylate, meth(acrylate) or water/solvent based urethane or epoxy functionalities. Through combinations of mono and multi-functional oligomers, highly cross-linked coatings can be delivered. The weight percentage of reactive monomer in the coating ranges from about 5 to 95% by weight of the entire coating composition.
Reactive component B typically includes at least one diisocyanate component including at least one of diphenylmethane 4,4xe2x80x2-diisocyanate, toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, or mixtures thereof. In a preferred embodiment, reactive component B includes aziridine. In another preferred embodiment, reactive component B includes at least one photoinitiator.
The invention contains a relatively xe2x80x9chardxe2x80x9d material that includes colloidal silica in an amount sufficient to increase the abrasion resistance of the coating, and optionally includes one or more types of organic or inorganic particles, which is dispersed throughout the polymer and bonded to at least one of the reactive components by the coupling agent. The colloidal silica can include untreated or pretreated colloidal silica(s), or silica related compounds, such as those sold commercially as Cab-O-Sil by Cabot Corp. of Tuscola, Ill. or NYACOL 2040 by Nano Technologies of Ashland, Mass., HYLINK OG series by Clariant Corporation of Charlotte, N.C., or the SNOWTEX series of colloidal silica by Nissan Chemical Industries of Tokyo, Japan. In one preferred embodiment, optional hard particles including corundum and oxides such as MgO, zirconium oxide or ZnO, can be included in the composition with the colloidal silica to improve the abrasion resistance. The colloidal silica is typically present in the coating material in an amount of greater than 5 weight percent, preferably about 5 to 80 percent, and more preferably from about 5 to 60 percent by weight of the composition. In one preferred embodiment, the colloidal silica is present in an amount of about 10 to 30 percent, and in another preferred embodiment it is present in an amount from about 15 to 20 percent by weight of the composition.
A suitably glossy coating having sufficient abrasion resistance can be achieved using such amounts of colloidal silica in the coating of the invention. In a preferred embodiment, abrasion resistance can be significantly improved by the dispersion of the colloidal silica in a matrix formed from acrylate or methacrylate functional monomers and oligomers. As used herein, xe2x80x9ccolloidal silicaxe2x80x9d should be understood to be distinct from xe2x80x9csolid silica,xe2x80x9d which refers to compounds such as hydrous silicic acid and silicic anhydride that are not included within the colloidal silicas of the invention. xe2x80x9cColloidal silicaxe2x80x9d refers to silica disposed in a solvent. For coatings, the solvent typically includes water or one or more ketones, alcohols, or any combination thereof.
Coatings may be produced, for example, which contain small spherical particles of silica, linked to the organic matrix through a silane coupling agent interface. The nanometer size of the silica particles and the refractive index of said material are useful for clear coatings, since they do not cause light scattering and thus do not interfere with the light transmission in the way fillers of larger particle size do. For pigmented or tinted coatings this is not an issue. In a preferred embodiment of the invention, the colloidal silica microparticles range in size from about 1 nm to 200 nm. In one embodiment, the colloidal silica microparticles range in size from about 50 nm to 100 nm.
The colloidal silica is typically used in the invention dispersed in a solvent. The solvent can include monomer or oligomer, or both. The solvent can include water for water-reducible coatings. For dual cure systems, the solvent can be a monomer or oligomer. xe2x80x9cDual curexe2x80x9d refers to curing that includes a combination of at least heat and ultraviolet radiation. Those of ordinary skill in the art can readily determine other suitable solvents used with the colloidal silica, particularly with reference to the description of the invention herein.
Any hard material that is capable of being triturated and which has a hardness greater than that of the material forming the continuous phase of the coating may be optionally used in the present invention with the colloidal silica. In a preferred embodiment of the invention, a material having a Mohs hardness greater than or equal to about 5 is used. It is also preferred to use particulate matter which is capable of being bound to a continuous phase coating material through a use of a coupling reaction.
Optional hard particulate materials for use in the coating of the invention include, but are not limited to: Actinolite; Aegirine; Akermanite; Almandine; Analcite; Anatase; Andalusite; Andesine; Andradite; Anorthite; Anorthoclase; Anthophyllite; Apatite; Arsenopyrite; Augelite; Augite; Axinite; Baddeleyite; Benitoite; Bertrandite; Beryl; Beryllonite; Bixbyite; Boracite; Braunite; Bravoite; Breithauptite; Brookite; Cancrinite; Cassiterite; Celsian; Chloritoid; Chondrodite; Chromite; Chrysoberyl; Clinozoisite; Cobaltite; Columbite; Cordierite; Cordundum; Cristobalite; Cummingtonite; Danburite; Datolite; Derbylite; Diamond; Diaspore; Diopside; Dioptase; Enstatite; Epidote; Euclasite; Eudialite; Euxenite; Fayalite; Fergussonite; Forsterite; Franklinite; Gahnite; Gehlenite; Geikielite; Glaucophane; Goethite; Grossularite; Hambergite; Hausmannite; Haxc3xcyne; Hendenbergite; Helvite; Hematite; Hemimorphite; Hercynite; Herderite; Homblende; Humite; Hydrogrossularite; Ilmenite; Jadeite; Kaliophyllite; Kyanite; Lawsonite; Lazulite; Lazurite; Lepidocrocite; Leucite; Loellingite; Manganosite; Marcasite; Marialite; Meionite; Melilite; Mesolite; Microcline; Microlite; Monticellite; Nepheline; Niccolite; Nosean; Oligoclase; Olivine; Opal; Orthoclase; Orthopyroxene; Periclase; Pekovskite; Petalite; Phenakite; Piemontite; Pigeonite; Pollucite; Prehnite; Pseudobrookite; Psilomelane; Pumpellyite; Pyrite; Pyrochlore; Pyrolusite; Pyrope; Quartz; Rammelsbergite; Rhodonite; Rutile; Samarskite; Sapphirine; Scapolite; Silica; Sodalite; Sperrylite; Spessartite; Sphene; Spinel; Spodumene; Staurolite; Stibiotantalite; Tantalite; Tapiolite; Thomsonite; Thorianite (R); Topaz; Tourmaline; Tremolite; Tridymite; Ullmannite; Uraninite (R); Uvarovite; Vesuvianite; Wagernite; Willemite; Zircon; and Zoisite; and combinations thereof, as named in the table xe2x80x9cPhysical Constants of Mineralsxe2x80x9d from the CRC HANDBOOK OF CHEMISTRY and PHYSICS, 52ND EDITION 1971-1972 (P. 193-197) THE CHEMICAL RUBBER CO., CLEVELAND, OHIO.
In one preferred embodiment, the hard particulate material is present in the coating in an amount of about 2 to 25 weight percent in addition to the colloidal silica.
The colloidal silica is preferably combined with a coupling agent, which includes one or more compounds to aid in adhesion and dispersion of the filler particles. For purposes of the present invention, the term xe2x80x9ccoupling agentsxe2x80x9d as used herein preferably refers to compounds having a plurality of functionalities, at least one of which is capable of interacting or bonding to the surface of the colloidal silica, and at least one other functionality capable of interacting or bonding to the reactive component within the coating, such as the polymers or monomers that are included in the coating of the invention. Any coupling agent that is suitable for bonding to the surface of a colloidal silica material, the polymer precursor component, or to the coating matrix is suitable for use in the present invention. Suitable coupling agents include silane coupling agents, and optionally further include one or more of chromates, titanates, zirconium, zircoaluminate, and polymeric coupling agents.
Particularly preferred silane coupling agents have the formula Yxe2x80x94(CH2)nSiX3, wherein Y is an organofunctional group providing the bonding with the polymer matrix attached to the central silicon atom via the stable (CH2)n carbon chain (e.g., a substituted or unsubstituted aryl, alkyl or carbocyclic group) and X represents the silicon-functional or alkoxy group (e.g., OCH3, OC2H5, OC2H4OCH3) that hydrolyzes and subsequently reacts with the active sites on inorganic surfaces. The coupling agent has a polyvalent backbone including at least one of silicone and phosphorus radicals, alkyl groups having a chain length of 1 to 12 carbon atoms, and polymers and oligomers selected from the group consisting of acrylic, polyester, polyether, urethane, urea, polyamide, epoxy, and alkyd oligomers and polymer mixtures thereof. The first functionality on the backbone is reactive with colloidal silica, including at least one of hydroxy, phenoxy, hydroxy ether, silane or aminoplast functionalities. The second functionality on the backbone is reactive with one of the reactive components, including at least one of hydroxy, isocyanate, carboxyl, epoxy, amine, urea, vinyl, amide, amimoplast or silane functionalities.
For purposes of the present invention, the term xe2x80x9csubstituted or unsubstituted arylxe2x80x9d means a hydrocarbon ring bearing a system of conjugated double bonds, usually comprising six or more even number of B (pi) electrons. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, anisyl, tolyl, xylenyl and the like. According to the present invention, aryl also includes heteroaryl groups, e.g., pyrimidine and thiophene. These aryl groups may also be substituted with any number of a variety of functional groups. Such functional groups can be epoxide, nitro, mercapto, amino, ureido, vinyl, isocyanato, or methacrycoxy groups, in addition to those discussed below used in conjunction with substituted alkyl and/or carbocyclic compounds.
xe2x80x9cAlkylxe2x80x9d is used herein to mean linear chain or branched chain alkyl groups of from 1 carbon atom up to about 30 carbon atoms including any substituted or unsubstituted acyclic carbon-containing compounds, such as alkanes, alkenes and alkynes. Examples of alkyl groups include lower alkyl, for example, methyl, ethyl, n-propyl, iso-propyl, -butyl, iso-butyl or tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and the like; upper alkyl, referring to carbon based molecules having from 20 to 30 carbon atoms; and lower alkylene, for example, ethylene, propylene, propyldiene, butylene, butyldiene, and the like. The ordinary-skilled artisan is familiar with numerous linear and branched alkyl groups which are within the scope of the present invention.
In addition, the alkyl group(s) may also contain various substituents in which one or more carbon and/or hydrogen atoms has been replaced by a functional group. Functional groups include but are not limited to hydroxyl, amino, carboxyl, amide, ester, ether, epoxide and halogen (fluorine, chlorine, bromine and iodine), to mention but a few. In a preferred mode of the present invention, R will be a linear or branched chain having from about 1 to 18 carbon atoms.
xe2x80x9cCarbocyclicxe2x80x9d is herein defined as substituted and unsubstituted carbocyclic groups of up to about 20 carbon atoms. The term as used herein means cyclic carbon-containing compounds, including but not limited to cyclopentyl, cyclohexyl, cycloheptyl, admantyl and the like. Such cyclic groups may also contain various substituents in which one or more hydrogen atoms has been replaced by a functional group. Such functional groups include those described above, as well as the lower alkyl groups described above. The cyclic groups of the invention may further comprise a heteroatom, for example, cyclohexanol.
The most preferred coupling agents for use with the invention include those sold under the tradename SILQUEST(copyright) organofunctional silanes by OSi Specialties, Danbury, Conn. SILQUEST(copyright) A-174, A-1230, A-171, A-187, A-1100 and A-189 are specific products available. Other preferred silane coupling agents include Z-6011, Z-6040, Z-6030 and Z-6020 silanes available from Dow Coming corporation of Midland, Mich.
Titanate coupling agents include, for example, monoalkoxy titanate compounds, chelate titanate compounds, quad titanate compounds, coordinate titanate compounds, neoalkoxy titanate compounds and cycloheteroatom titanate compounds, to name but a few. Such titanates are available, for example, from Du Pont Company of Wilmington, Del. under the tradename TYZOR, TPT, TBT and TOT.
Zirconium coupling agents may include, for example, zircoaluminates, zirconium propionate, neoalkoxy zirconate and ammonium zirconium carbonate, available from Magnesium Elektron, Inc. of Flemington, N.J.
Zircoaluminate coupling agents have both an aluminum and a zirconium functional group in addition to an organic functionality. Such zircoaluminate coupling agents are described, for example, in U.S. Pat. Nos. 4,539,048 and 4,539,049, issued Sep. 3, 1985, both of which are herein incorporated in their entirety by express reference thereto. The most preferable class of coupling agents are silicone based coupling agents, including aminosilanes, mercaptosilanes, glycidoxysilanes, epoxysilanes, methacryloxysilanes, vinylsilanes, and the like, or combinations thereof. This class includes alkoxysilane oligomers, nonionic silane dispersing agents, octyltriethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyl-tris (2-methoxyethoxy) silane, gamma-methacryloxypropyltrimethoxysilane, beta-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-mercaptopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, aminoalkyl silicone solutions, modified aminoorganosilane, gamma-aminopropyltrimethoxysilane, -beta-(aminoethyl)-gamma-aminopropyltrimethoxysilane, modified aminoorganosilane, modified aminosilanes, triaminofunctional silanes, aminofunctional silanes, polyazamide silanes, gamma-ureidopropyltriethoxysilane, isocyanatofunctional silanes; and mixtures thereof.
The weight ratio of the coupling agent to the colloidal silica solids can be any amount that will result in the formation of a suitable abrasion resistant coating upon a golf ball or club, or a portion thereof. Useful ratios of the coupling agent to the colloidal silica solids are about 1:1 to 1:90, or more preferably from about 1:1 to 1:40. In one embodiment, the ratio is about 1:6 and in another embodiment is about 1:12. The combination of the solids of colloidal silica and the coupling agent has a ratio to the resin solids combination of the resin and crosslinking agent. Useful ratios are about 1:1 to 1:50 and, more preferably, from about 1:1 to 1:10. In one preferred embodiment, the ratio is about 1:8, and in another embodiment, the ratio is about 1:4.
The coatings of this invention may further be obtained by evaporation of a water-based or an organic-solvent based system. They may also be obtained by an ultraviolet (UV) cure of a suitably reactive system. The coating may be applied as a clear or pigmented primer or as a topcoat or as a single layer combining the properties of both.
The amount of coating applied to a standard-sized golf ball (1.680 inch diameter) is in the range of 0.01 g to 1 g. Preferred reaction and coating conditions vary with both the chemical compositions and the application methodology but are well known in the art. The methodology for coating golf balls according to the present invention can be any that is known to the ordinary-skilled artisan and is acceptable for application of a liquid containing particulate matter. Golf ball coating application techniques include spray, electrostatic, dip, spin curtain and those methods described in for example U.S. Pat. Nos. 5,461,109, 5,409,233, 5,000,458, 4,871,589, 4,798,386 and 5,300,325. All of the aforementioned patents, patent applications and other printed publications here and elsewhere in the Detailed Description are incorporated herein by express reference thereto.
In one embodiment, substantially all of the coating remains adhered to the golf ball after repeated hits with a golf club. xe2x80x9cSubstantially allxe2x80x9d is herein defined as at least about 90 percent, preferably at least about 95 percent, and more preferably at least about 99 percent, of the coating remains adhered to the golf ball.
In one embodiment, the coating can be applied to a golf shaft, iron-type club, or a portion thereof. For example, the coating can be disposed over at least a portion of the back cavity of an iron-type club, the club face, the crown of a metal wood-type club, or the sole of a metal wood-type club to inhibit or avoid abrasion of the club itself.

Abrasion resistant coated golf equipment


Gelled hydrocarbon compositions are provided which include a low molecular weight triblock polymer and a medium molecular weight triblock polymer. These gels can be used to make clear candles.

The invention relates to a clear candle containing a gelled or solidified hydrocarbon oil.
Candles of gelled hydrocarbon oils are well known, for example, as described in International Patent Publication Nos. WO 96/34077 and WO 97/08282. However, these gelled, clear candles have the potential to catch fire, since the difference between the pool temperature and flashpoint is smaller than in conventional wax candles. If the candle then ignites, flames as high as 30 cm can occur with black smoke emanating. This is a potential health hazard and, indeed, is a reason why there have been a number of product recalls.
In addition it is important that the gelled candles do not flow when the candle holder is tipped on its side (e.g., as may occur during transportation or accidental spillage). Once the wick is buried in the gelled candle material, the product is spoiled. In other words, such a candle material must be firm (i.e., not flow) and have a large difference between the pool temperature and the flash point.
In the past it has been found that if, for example, the difference between the pool temperature and flash point is an acceptable amount, then there is too much flow, or vice versa. It has proved to be very difficult, if not impossible, to obtain an acceptable difference between pool temperature and flash point and, at the same time, produce a candle having desirable flow.
It is also well known in the art to use such gelled hydrocarbon oils for uses other than candles. For example, European Patent No.0 224 389 discloses styrene-dyene block copolymer compositions. However, none of these compositions would have suitable characteristics for forming candles.
International Patent Application No. WO97/31623 discloses gelled compositions suitable for a wide range of uses, but not suitable for use in candles. This is particularly because the hydrocarbon used in the compositions disclosed in this international application are volatile and thus would be likely to present a severe fire hazard if used in candles. In addition, the material forming the candle would simply disappear with time, due to evaporation of the hydrocarbon.
To alleviate these problems, there is provided a gelled hydrocarbon composition, suitable for use as a candle body, comprising a hydrocarbon oil gelled with a low molecular weight and a medium molecular weight triblock polymer.
It has been found that through careful selection of the low molecular weight and medium molecular weight triblock polymer, a candle having improved safety results. In other words, through this careful selection, a candle may be formed in which the flash point and the pool temperature have acceptable values, and the difference between the pool temperature and the flash point is also large enough. Further, the resultant candle does not flow when the candle holder is tipped on its side.
By low molecular weight triblock polymer is preferably meant a triblock polymer of molecular weight (either Mw or Mn) from 20,000 to 82,000, more preferably 50,000 to 82,000. Most preferably, Mw is about 78,000 and Mn is about 73,000, expressed as xe2x80x9cpolystyrene equivalentxe2x80x9d molecular weights. An example of such a low molecular weight polymer is KRATON(copyright) G1652.
By medium molecular weight triblock polymer is preferably meant a triblock polymer of molecular weight (either Mw or Mn) of from 82,000 to 150,000, more preferably 85,000 to 120,000. Most preferably, Mw is about 95,000 and Mn is about 89,600, expressed as xe2x80x9cpolystyrene equivalentxe2x80x9d molecular weights. An example of such a medium molecular weight polymer is KRATON(copyright) G1650.
Preferably, the molecular weight is measured by a technique known as xe2x80x9cComparison of the molecular weight distributions of ethylene-butylene-styrene copolymers using Gel Permeation Chromatographyxe2x80x9d, the process of which is as follows:
The determination of triblock polymers having low and medium molecular weight is expressed as the polystyrene equivalents. The samples are analyzed using gel permeation techniques with tetrahydrofuran as the solvent and columns appropriate to low/medium molecular weight polymers.
A single solution of the sample is prepared by adding 10 ml of solvent to 20 mg of the sample and leaving for a minimum of four hours to dissolve. A small amount of 1,2-dichlorobenzene in the solvent is added as an internal marker, and the solutions are mixed thoroughly. The solutions are filtered through a 0.2 micron polyamide membrane into sample vials, which are placed in an autosampler.
Chromatographic conditions are as follows:
Columns: Pl gel 2X mixed bed D 30 cm, 5 microns
Flow rate: 1.0 ml/min
Temperature: 30xc2x0 C.
Data acquisition and handling are carried out using Viscotek xe2x80x9cTrisec 3.0xe2x80x9d software. The GPC system was calibrated with polystyrene, and the results are expressed as xe2x80x9cpolystyrene equivalentxe2x80x9d molecular weight.
The term xe2x80x9ctriblock polymerxe2x80x9d is one well known in the art, and suitable triblock polymers are styrene-ethylene/butylene-styrene block copolymers, such as are sold under the trade name KRATON(copyright) G by Shell. These copolymers are hydrogenated and are thus thermally stable. That is to say, decomposition is not likely to occur during the blending of the copolymer with the hydrocarbon oil. The KRATON(copyright) G copolymers are indicated as being compatible with paraffinic and napthenic oils and are reported as taking up more than 20 times their weight in oil to make a gelled product. Such co-polymers are described in WO 96/34077 and WO 97/08282, the contents of which are incorporated herein by reference.
The triblock is often substantially pure triblock and may also include up to 5% diblock copolymer. Alternatively, the triblock copolymers may contain blends with radial block copolymer or multiblock copolymer. Such copolymers and blends are described in WO 97/08282 and WO 97131623.
Desirable blends of low molecular weight and high molecular weight are in the ratios of 1:20 up to 20:1. Preferably, the blends are in the ratio of 1:10 up to 10:1, more preferably 1:5 up to 5:1.
Both the low and medium molecular weight polymers are tri-block co-polymers of the form a-b-a, where b is an oil soluble residue (e.g., ethylene or butylene) and a is an insoluble styrene residue. An example of this type of polymer is from the KRATON(copyright) G series of thermoplastic rubber polymers.
These polymers are a linear block styrene-ethylene-butylene-styrenes (SEBS) which have been hydrogenated to impart thermal stability during processing. These tri-block polymers are supplied as  greater than 99% pure systems with either low, medium or high molecular weights. These products can then be blended in the laboratory to change the rheological properties of the final hydrocarbon-oil gel as desired.
The hydrocarbon oil used is desirably a natural or synthetic hydrocarbon oil of C16 to C50, desirably as disclosed in WO 96/34077 or WO 97/08282. The oil may, for example, be a paraffinic oil, a naphthenic oil or a natural mineral oil. The hydrocarbon oil can, for example, be a natural or synthetic cosmetic grade hydrocarbon oil. The hydrocarbon oil desirably is in liquid form at temperatures from 0xc2x0 C. to 200xc2x0 C. Preferred hydrocarbon oils are selected from paraffinic oils naphthenic oils or natural mineral oils, more preferably a white oil.
Advantageously, the vapour pressure of the hydrocarbon oil is very low, typically negligible at 20xc2x0 C. Preferably, hydrocarbon oil comprises a carbon chain of 18 to 30 carbons.
The resistance to flow of the gelled compositions can be improved further by the addition of 0.01-3 wt % of a fatty acid, e.g., a compound of formula I or formula II:
HOxe2x80x94(CH2)uxe2x80x94COOHxe2x80x83xe2x80x83(I)
CH3xe2x80x94(CH2)pxe2x80x94CH(OH)xe2x80x94(CH2)qxe2x80x94COOHxe2x80x83xe2x80x83(II)
in which u is 8 to 24; p is 0 to 16, preferably 1 to 8, more preferably 3 to 5; and q is 8 to 24, preferably 8 to 16, more preferably 8 to 10. Desirably p plus q is from 8 to 24, preferably 12 to 20, more preferably 14 to 18.
A preferred fatty acid is a stearic acid containing one or more hydroxy groups. A particularly preferred stearic acid is 12-hydroxystearic acid.
A gelled composition according to the invention will generally have an attractive clear appearance.
Further, according to the invention, there is provided a candle comprising
i) a candle body, and
ii) a wick located in the body,
the body comprising a gelled hydrocarbon composition comprising a hydrocarbon oil and from 0.01 to 3 wt % of a fatty acid, the composition being gelled by polymerization with a low molecular weight and a medium molecular weight triblock polymer.
Still further, according to the invention, there is provided a process for preparing a gelled hydrocarbon composition comprising:
i) mixing (e.g., homogenizing) the hydrocarbon oil with the powdered triblock copolymers at elevated temperature (e.g., 100-120xc2x0 C.), and
ii) optionally reducing the temperature of the above mixture (e.g., to about 70-90xc2x0 C.), and
iii) while mixing (e.g., at 400-500 rpm) adding the fatty acid and, optionally, fragrance and/or other additives to the above mixture.
The resulting mixture may then be homogenized at, for example, 400-500 rpm.
The candle body desirably comprises the hydrocarbon oil in an amount of 70 to 99 wt %, preferably 85 to 95 wt %, more preferably about 90 wt %. Preferably, the triblock polymers are present in an amount of 1-30 wt %, more preferably 5-15 wt %. Preferably, the fatty acid is present in an amount of 0.1 to 3 wt %, more preferably 0.2 to 2 wt %, most preferably 0.5 to 1 wt %.
The candle body may further comprise components, preferably 1 to 20% wt, such as one or more compounds selected from fragrances, malodor counteractants, insecticides, pesticides, insect repellants, colorants, anti-oxidants, preservatives, anti-ingestion agents, stabilizers, deodorizers, and masking agents.
Suitable fragrances are generally known in the art, for example one comprising fragrant materials selected from one or more of the following: cedarwood oil, sandalwood oil, bergamot, Bulgarian rose oil, patchouli, myrrh, clove leaf oil, linalol, ethyl alcohol, tepineol, menthol, citronella, and phenyl ethyl alcohol. The fragrance normally comprises a carrier solvent, such as diethylphthalate, carbitol, dipropyleneglycol, or dipropylglycol. Preferably, 1-10 % wt are present.
Suitable malodor counteractants are well known, for example one or more aroma and/or non-aroma chemicals which are known to have an action in reducing the perception of the intensity of malodors, for example unsaturated esters, ketones, aldehydes, and/or fragrant materials, such as citronella or cedarwood oil (which is known to counteract the perception of tobacco malodor). Preferably, 0.1-10 wt % are present.
Suitable insecticides, pesticides and insect repellants are well known for use in the invention, for example a pyrethroid, niotinoid, rotenoid, tetramethrin, bioallerthrin, allethrin, phenthrin, dinitrophenol, organothiocyamate, benzene hexachloride, citronellal, a polychlorinated cyclic hydrocarbon (for example Heptachlor(copyright), Aldrin(copyright) or telodrin) or an organophosphorus compound, for example tetraethyl pyrophosphate). Preferably, 1-10 wt % is present.
Any colorant used should be oil soluble. Examples of suitable colorants are Iragon(copyright) Green, Iragon(copyright) Violet, Sandoplast Blue 2B, and Fat Red 5B02. Preferably, up to 2 wt % is present.
A suitable anti-oxidant is, for example, tocopherol, ascorbyl palmitate, butylated toluene, ascorbic acid, tert-butyl hydroquinone, beta carotene, butylated hydroxy toluene, or a gallate. Preferably, 0.1 to 2 wt % of an antioxidant may be present in the composition.
Suitable preservatives are quaternary alkyl ammonium compounds or imidazolinium derivatives. Preferably, 0.1 to 2 wt % of a preservative may be present in the composition.
An example of a suitable anti-ingestion agent is Bitrex(trademark), which is made by McFarlane Smith Ltd and comprises denatonium benzoate. Preferably, up to 2 wt % of an anti-ingestion agents may be present in the composition.
A gelled composition according to the invention preferably comprises in addition to the hydrocarbon and the triblock copolymer:
i) fragrance in an amount of up to 7 wt %, preferably up to 5 wt %,;
ii) coloring agent in an amount of up to 1 wt %; and
iii) anti-oxidant in an amount of up to 1 wt %.
All of the above percentages are in relation to the total weight of the candle body composition, i.e., excluding the wick and container.
A candle body may be prepared by mixing the hydrocarbon oil and the medium molecular weight triblock copolymers and low molecular weight triblock copolymers at an elevated temperature, e.g., 100-120xc2x0 C., and then cooling to a temperature of 70 to 90xc2x0 C., more preferably 80xc2x0 C. to 85xc2x0 C. On cooling further the composition may then be added while the oil/polymer mix is still in liquid form. Preferably, the components are mixed together and then poured into a container containing the wick to form the candle body.
Alternatively, polymerization of the gelled composition can be conducted in molds or carried out to form a continuous or semi-continuous body, which is then cut into the desired shapes. Preferably, the polymerization takes place when the wick is already present.
The invention will be illustrated by the following specific, non-limiting Examples.
The candle consists of a liquid mineral oil that is gelled using a polymeric thickening agent, e.g., a KRATON(trademark) copolymer. The candle may also contain fragrance and, if desired, a dye.
The appropriate amount of oil is weighed into a beaker and heated up to 120xc2x0 C., while stirring with a Heidolph mixer at 350-450 rpm.
When the oil reaches 120xc2x0 C., copolymeric thickening agent(s), e.g., the KRATON(copyright) copolymer(s) is/are gradually added while stirring.
When all the KRATON(copyright) copolymer has dissolved, the temperature of the mix is reduced to about 85xc2x0 C., and fragrance and 12-hydroxystearic acid (if present) are added slowly and left to stir for 10 minutes. Care is needed in adding the fragrance to the mix.
The heater is turned off, and a dab of gel mix is used to fix the wick to the base of the glass. The gel is then poured into candle glasses (100 g fill weight).
The mix compositions are as set out below. All amounts are in percentages by weight.


A composition for selective etching of oxides over a metal. The composition contains water, hydroxylammonium salt, carboxylic acid, a fluorine containing compound, and optionally, a base. The pH of the composition is about 2 to 6.

The present invention relates to a composition for use in microelectronics applications. More particularly, the present invention relates to a composition for selectively etching oxides remaining after plasma etching and/or chemical mechanical polishing (CMP) of a metal substrate having low dielectric constant (low-k) interlayers.
As the dimension of the photolithographic pattern on a wafer continues to shrink below 0.18 microns, greater demands are placed on lithographic equipment and materials. To meet this challenge, the semiconductor industry is turning to copper and low dielectric constant (low-k) materials to manufacture chips. Copper is known to provide as much as a 40% decrease in resistance. Moreover, when using low-k materials there is a decrease in capacitance, which is critical to improving integrated circuit performance, especially for higher density memory chips. More and more, the metal substrate and inter-dielectric layer materials are changing from aluminum based alloys and silicon dioxide to copper metal and the new low-k dielectrics.
Low-k materials can be divided into two categories. The first category includes inorganic low-k materials such as hydrogen silsesquioxane (HSQ), fluorinated silicon glass (FSG), or other non-carbon containing silicon based materials. The second category is comprised of organic low-k materials, such as bisbenzocyclobutene (BCB) available from Dow Chemical and poly(arylene ether) sold under the tradenames FLARE from Allied Signal, and SiLK from Dow Chemical.
To utilize copper and the low-k materials, new manufacturing methods are employed. One method is the Damascene method, which follows several basic steps. First, an insulator is deposited. Next, a photoresist pattern with the reverse image of the metal is added. This is followed by etching a trough in the oxide at a depth equal to the desired metal thickness. A liner and copper are then deposited. This is followed by chemical mechanical planarization to remove the excess copper.
An essential step in the manufacturing process is the removal of residues from the wafer surface. Cleaning compositions for cleaning silicon or aluminum wafer surfaces are well known in the art. However, compositions that are effective in selectively etching oxide residues from a metal substrate that contains low-k interlayers, are not readily available. The industry""s move to copper and low-k materials has created a need for such a composition that is specifically formulated to remove residues from a metal substrate, i.e. copper, without damaging the low-k interlayers.
The present invention is directed to a composition for selectively etching oxide residues remaining after plasma etching and/or chemical mechanical polishing, from a metal substrate such as copper that has low-k interlayers. The composition contains water, hydroxylammonium salt, carboxylic acid, a fluorine containing compound, and optionally, a base. The pH of the composition is about 2 to 6.
The present invention is a composition that has utility for selectively etching the oxide residue that remains after plasma etching and/or chemical mechanical polishing of a metal substrate that contains low-k interlayers. The metal substrate may be, for example, copper, aluminum, tantalum, or tungsten. The present invention removes the residue without damaging the metal substrates and the low-k interlayers contained within the substrate.
In the present invention, the composition is comprised of water, hydroxylammonium salt, carboxylic acid, and a fluorine-containing compound. In addition, a base may be included.
The present invention includes a water soluble hydroxylammonium salt of an organic or inorganic acid that removes post-etch residue. Hydroxylammonium salts, such as hydroxylammonium sulfate (HAS), are effective in dissolving the post-etch residue formed on a silicon dioxide/titanium nitride/aluminum-copper substrate, due to its acidity and physical/chemical properties. For example, HAS is a major component in MICROSTRIP 5002, a product commercially available from Arch Chemicals, Inc., which is useful in removing post-etch residues remaining after via and aluminum line etching. The hydroxylammonium salt may be, for example, hydroxylammonium sulfate, hydroxylammonium nitrate, hydroxylammonium phosphate, hydroxylammonium chloride, hydroxylammonium oxalate, hydroxylammonium citrate, hydroxylammonium lactate, or mixtures thereof. The preferred hydroxylammonium salt is hydroxylammonium sulfate.
The composition of the present invention includes about 0.01 wt. % to 5.0 wt. % of a hydroxylammonium salt. Preferably about 0.05 wt. % to 1.0 wt. %, and most preferably about 0.1 wt. % to 0.5 wt. % of a hydroxylammonium salt is included.
A carboxylic acid must be included in the composition of the present invention. The carboxylic acid serves as a corrosion inhibitor. Carboxylic acids, especially those containing hydroxyl groups, can effectively inhibit metal corrosion of aluminum, copper, and their alloys. The carboxylic acids have a chelating effect on those metals. Suitable carboxylic acids include monocarboxylic and polycarboxylic acids. For example, the carboxylic acid may be, but is not limited to, formic acid, acetic acid, propionic acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, 1,2,3-benzenetricarboxylic acid, glycolic acid, lactic acid, citric acid, salicylic acid, tartaric acid, gluconic acid, and mixtures thereof. The preferred carboxylic acid is citric acid.
The carboxylic acid is conveniently added in an amount about 0.01 wt. % to 5.0 wt. %. Preferably about 0.05 wt. % to 3.0 wt. %, and most preferably about 0.1 wt. % to 1.0 wt. % of carboxylic acid is added.
The present invention requires the presence of a water soluble fluorine-containing compound that may be organic or inorganic. The fluorine-containing compound acts as a selective etchant for oxides against metals. For example, fluorine-containing compounds, particularly fluoride salts like hydrogen fluoride (HF) are known to selectively attack silicon dioxide against silicon due to cleavage of Sixe2x80x94Oxe2x80x94Si bonding. It is also known that some fluorine containing compounds can cleave Cuxe2x80x94Oxe2x80x94Cu bonding so that CuOx can be selectively etched against copper. Examples of suitable fluorine-containing compounds are, hydrogen fluoride, ammonium fluoride, hydrogen fluoride pyridine salt, hydrogen fluoride imidazole salt, tetramethylammonium fluoride, tetraethylammonium fluoride, hydrogen fluoride polyvinylpyridine salt, hydrogen fluoride polyvinylimidazole salt, hydrogen fluoride polyallylamine salt, or mixtures thereof. Hydrogen fluoride is the preferred fluorine containing compound.
The composition includes about 0.001 wt. % to 3.0 wt. % of a fluorine-containing compound. Preferably about 0.005 wt. % to 1.0 wt. %, and most preferably about 0.01 wt. % to 0.5 wt. % of the composition is a fluorine containing compound.
Optionally, the composition may include a base. The base is used to adjust the pH of the composition, which must be about 2 to 6. Preferably, the pH of the composition is about 3.0 to 4.5. It is critical that the pH of the cleaning composition be acidic. This enables the composition to selectively etch metal oxides such as any oxide of copper or mixtures thereof (CuOx) against silicon dioxide as well as metals like copper and aluminum. Silicon dioxide readily dissolves in an alkaline pH region, but not where the pH is neutral or acidic. In contrast, metal oxides such as CuOx dissolve in both acidic and alkaline pH environments. As such, the pH of the composition of the present invention is set to or adjusted to about 2 to 6. The pH is adjusted by adding a base. The base can be, for example, a tetraalkylammonium hydroxide, such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, or mixtures thereof. Tetramethylammonium hydroxide is the preferred base to be used in the present invention.
The present invention may also include a water-miscible organic solvent. The water-miscible organic solvent enhances the penetration of water into the photoresist film with other components, particularly the fluorine-containing compound. This accelerates the silicon dioxide etching to remove the photoresist film from the low-k layer. In actuality, the low-k film is on the copper layer directly or indirectly through another layer such as silicon nitride, which is not etched by the present invention, so that the low-k film is not removed. The water-miscible organic solvent may be, for example, ethylene glycol (EG), propylene glycol (PG), dimethylsulfoxide (DMSO), dimethylacetamide (DMA), ethyl lactate (EL), propylene glycol monoethylether acetate (PGMEA), or mixtures thereof.
The present invention may further include additives. Additives such as chelating compounds or surface active agents can enhance the effectiveness of the composition of the present invention in removing particulate and/or metallic contaminants from the wafer surface. Suitable additives are, for example, nonionic surfactants, especially chelating group attached polyoxyethylene type surfactant known as CS-1, which is commercially available from BASF.
In a preferred embodiment of the present invention, the composition for selective etching of oxides over metals comprises: water, about 0.1 wt. % to 0.5 wt. % hydroxylammonium sulfate, about 0.1 wt. % to 1.0 wt. % citric acid, about 0.01 wt. % to 0.5 wt. % hydrogen fluoride, and has a pH of about 3.0 to 4.5. Moreover, the composition has a molar ratio of citric acid to hydrogen fluoride of about 1 to 5.
The present invention also includes a method for removing the residue on a metal substrate, such as copper, aluminum, tantalum, or tungsten having low-k interlayers comprising the step of applying a composition comprising (a) water, (b) hydroxylammonium salt, (c) carboxylic acid, and (d) a fluorine containing compound to the metal substrate. The composition may be applied, for example, by immersing or spraying the composition onto the metal substrate with or without sonication. The composition may also include a base and/or a water-miscible organic solvent. It is also preferred that the composition have a pH of about 2 to 6. More preferably, the pH should be about 3.0 to 4.5.
To illustrate the present invention, the following example is provided. It should be understood that the present invention is not limited to the example described.

Composition for selective etching of oxides over metals


A connector with inhibited crosstalk for high speed signal circuits, where the connector contains an insulator formed from a resin composition obtained by incorporating 5 to 85% by weight of a ceramic dielectric powder having a dielectric constant of 30 or more determined at 25xc2x0 C. and 1 MHz in a matrix resin, and the insulator is substantially homogeneous in the dielectric constant throughout the insulator.

1. Field of the Invention
The present invention relates to connectors, and more particularly, to a connector suitable for high-speed signal circuits in which crosstalk is inhibited and impedance matching can easily be established.
2. Related Art
In recent years, as electronic information devices grow more sophisticated, the rate of signals treated with electronic circuits is increasing very rapidly. Moreover, circuits are being densified and integrated, and a distance between signal lines is being shortened. Because of such increase in the rate of signal transmission and miniaturization of devices, to secure packaging technology and wiring technology which can control noises and delay is increasing in importance to such an extent that it becomes a governing condition of the whole system.
In light of such a present situation, there have been made a variety of suggestions for dealing well with high-speed, high-density signal circuits also in the field of connectors. What is important for connectors for high-speed, high-density signal circuits is crosstalk control and impedance matching. Crosstalk is a failure associated with an electromagnetic behavior of signals in a high-frequency circuit and refers to a phenomenon that signal lines arranged side by side interfere with each other. With reduction in a distance between signal lines resulting from densification of a circuit, the crosstalk control is becoming an important challenge. Impedance matching refers to a procedure to cause signal circuits mutually connected to have a predetermined impedance (usually standardized at 50 xcexa9, 75 xcexa9 or 90 xcexa9) since if the circuits have impedances mismatched, reflection of signals and the like will occur at connecting portions thereof. To reduce an electrical transmission efficiency or to control the generation of reflected waves by establishing impedance matching is becoming an important challenge for achieving the increase in signal transmission velocity (the increase in frequency). Moreover, impedance mismatching itself will cause crosstalk.
As means for solving such problems, Japanese Patent Laid-Open No. 243936(1994) discloses a composition wherein an earthed conductor is disposed between signal terminals. In such a composition, however, a connector structure becomes complicated and its applicable range will be restricted. Japanese Patent Laid-Open No. 96814(1994) provides means for ensuring impedance matching by adjusting the area of the main body parts of terminals. This approach is unique as an impedance matching method, but is not suitable for a small production because to design the optimum shape requires the adjustment involving the change of a mold. Japanese Patent Laid-Open No. 162227 (1996) proposes to adjust the area facing the adjoining contact to reduce impedance, thereby adjusting it. This approach, however, can not deal with those having impedances lower than the predetermined impedances due to limitations in design.
Japanese Patent Laid-Open No. 215819(1994) discloses means for establishing impedance matching by reducing impedance through providing, to paired conductor portions, such plane parts that can be given predetermined capacitances. However, also this approach requires much labor to form conductor portions of special shapes and the designing of the shapes of the plane parts is difficult.
Other various suggestions have been made in this technical field, but any means sufficiently simple and effective is not known, yet.
The object of the present invention is to provide a connector which can match impedances easily and a method for matching the impedance of a connector.
The connector of the present invention is that comprising an insulator and two or more conductor portions provided side by side within the insulator. The insulator is characterized by being formed of a composition obtained by incorporating, to a matrix resin, 5 to 85% by weight of a ceramic dielectric powder having a dielectric constant of 30 or more determined at 25xc2x0 C. and 1 MHz.
In the present invention, the dielectric constant, determined at 25xc2x0 C. and 1 MHz, of the resin composition constituting the insulator is preferably 5 to 20, and more preferably 7 to 15.
Moreover, in the present invention, it is preferable that the insulator is substantially homogeneous in the dielectric constant throughout the insulator.
The method for impedance matching of the present invention is that in which the impedance of an impedance matching-type connector is matched and is characterized by constituting the insulator of a connector by using a resin composition having a dielectric constant of 5 to 20 determined at 25xc2x0 C. and 1 MHz.
The resin composition constituting the insulator of the present invention is that obtained by incorporating, to a matrix resin, 5 to 85% by weight of a ceramic dielectric powder having a dielectric constant of 30 or more determined at 25xc2x0 C. and 1 MHz.
The matrix resin can be selected appropriately from various kinds of thermoplastic resins and thermosetting resins. However, from the viewpoints of moldability, heat resistance and mechanical strength, desirably used are polycarbonate resin, polyethylene terephthalate resin (PET resin), polybutylene terephthalate resin (PBT resin), polyamide resin such as polyamide 46, polyamide 6T, polyamide 6/6T, polyamide 6, polyamide 66, polyamide 11 and polyamide 12, polyphenylenesulfide resin, polyethersulfone resin, poly 1,4-cyclohexane-dimethylene-terephthalate resin (PCT resin), polyamideimide resin, polyphenylene ether resin (including polyphenylene oxide or the like), modified polyphenylene ether resin, polyphenylene ether resin including alloy resin made of polyphenyl ether resin and polyetherimide resin, polystyrene resin (particularly, syndiotactic polystyrene resin is preferred), 5-methylpentene resin, cyclic polyolefin resin, heat resistant ABS resin, aromatic polysulfone resin, polyether imide resin, polyether ketone resin, polyether ether ketone resin, polyether nitrile resin, thermotropic liquid crystal polyester resin (LCP), melt-resistant fluororesin, thermoplastic polyimide resin and the like.
Furthermore, the thermosetting resins are exemplified by triazine resin, thermosetting polyphenylene ether resin, epoxy resin and the like.
These resins can be used alone or after the mixing of two or more of them.
As the ceramic dielectric powder having a dielectric constant of 30 or more determined at 25xc2x0 C. and 1 MHz (this may, hereinafter, be referred simply to as xe2x80x9ca ceramic dielectric powderxe2x80x9d), there can be employed powders of various kinds of ceramics known as ferroelectrics typified by divalent metal salts of titanic acid typified by alkaline earth metal titanates such as barium titanate, lead titanate, strontium titanate, calcium titanate, barium-strontium titanate and barium-calcium titanate; metal zirconates such as barium-lead zirconate and lead zirconate; vanadic acid compounds such as sodium vanadate; metal niobates such as sodium niobate, potassium niobate, lead niobate and cadmium niobate; metal tantalates such as lithium tantalate, sodium tantalate, potassium tantalate, rubidium tantalate and lead tantalate; metal oxides such as titanium oxide, molybdenum oxide and tungsten oxide; and complex oxides such as lead titanate zirconate. Such a powder may be those having various shapes such as granular material, fibrous material and squamous material. Among them, fibrous powder and squamous powder are preferable because these can contribute also to the improvement in strength. Those having a dielectric constant of 100 or more determined at 25xc2x0 C. and 1 MHz are particularly preferable. These may be employed either alone in a single sort or in combination of two or more sorts. Preferred specific examples of them include metal titanates represented by a general formula MO TiO2 (in the formula, M denotes one kind or at least two kinds of metal selected from Ba, Sr, Ca, Mg, Co, Pd, Be and Cd) such as barium titanate, strontium titanate, calcium titanate, magnesium titanate, barium-strontium titanate and barium-calcium titanate. Fibrous powders having an average particle diameter of 0.05 to 3 xcexcm and an average aspect ratio of 3 to 200 are particularly preferable because of their excellent dielectric characteristics in a high-frequency region and of their reinforcing effects.
Of these metal titanates, most of their powdered products are easy to commercially obtain as commodity chemicals. Some fibrous products are marketed, but they can also be produced by the following production method. That is, an example may be a method comprising mixing a titanium source compound such as a titania compound represented by a general formula, TiO2. mH2O (in the formula, m is 0xe2x89xa6m less than 8) and one or two or more substances which can become oxides of metal M on heat and heating them to react at 600 to 900xc2x0 C. in the presence of a flux such as alkali metal halide. Moreover, as another method, they can be produced by covering, by a coprecipitation method, a surface of fibrous titania compound with a carbonate of metal M in an amount approximately equal to the molar amount of titanium and then heating.
As the ceramic dielectric powder, composite fiber comprising a metal titanate represented by general formula MO TiO2 (in the formula, M denoting one kind or two or more kinds of metals selected from Ba, Sr, Ca, Mg, Co, Pd, Be and Cd) and amorphous titanium oxide compositely united together in the form where the metal titanate is involved in the amorphous titanium oxide wherein the molar ratio of M to Ti is 1:1.005 to 1.85 can also be preferably used. Specific examples of such composite fiber include composite fiber comprising barium titanate and amorphous titanium oxide compositely united together in the form where the barium titanate is involved in the amorphous titanium oxide, and composite fiber comprising barium-strontium titanate and amorphous titanium oxide compositely united together in a form where the barium-strontium titanate is involved in the amorphous titanium oxide.
As a method for producing these composite fibers, they can be produced by covering the surface of a fibrous titania compound with a carbonate of metal M in a predetermined molar amount less than titanium by a coprecipitation method and thereafter heating. The thus obtained composite fiber is desirable since a connector superior in mechanical strength can be obtained therefrom because the composite fiber is strong as fiber and it is less broken off during its kneading into resin or molding.
Details of the production method of a dielectric powder that can be employed in the present invention are disclosed in Japanese Patent Nos. 2639989, 2716197, 2627955, 2788320, 2814288, 2711583, 276165, etc.
The resin composition constituting the insulator of the present invention is that obtained by incorporating 5 to 85% by weight of a ceramic dielectric powder to a matrix resin. Here, the incorporation ratio may be set so as to coincide the desired impedance in the connector. However, in usual, a dielectric constant of the resin composition is preferably set so that a dielectric constant determined at 25xc2x0 C. and 1 MHz becomes approximately 5 to 20, and in many cases, approximately 7 to 15. In such ranges, crosstalk can be controlled effectively.
To the resin composition for constituting the insulator of the present invention can be optionally incorporated, in addition to a matrix resin and a ceramic dielectric powder, coupling agents such as silane coupling agents, titanate coupling agents and zircoaluminate coupling agents, fine powder fillers such as talc, which is superior in an effect of improving a plating property, flame retardants such as those of phosphorus type, halogen type, antimony type and phosphazene type, coloring agents such as dyes and pigments, lubricants/sliding agents such as polyolefin powders, fluororesins and fats, mold releasing agents, impact-resistance imparting agents such as elastomer, which has the effect of improving impact resistance, antioxidants superior in improvability in heat stability, etc.
Moreover, unless the effect of the present invention is impaired, reinforcing fillers such as glass fiber, milled glass fiber, potassium titanate fiber, aluminum borate fiber, magnesium borate fiber, wollastonite, xonotlite, boehmite and mica can be used together. Particularly, the use of squamous fillers such as boehmite and mica is effective in reducing warp, which is desirable to be controlled especially in connectors.
The resin composition constituting the insulator can be obtained by, but is not limited to, dry-mixing ingredients as needed, followed by kneading and extruding with a twin screw kneader, followed by pelleterizing with a pelletizer.
It is preferable that the incorporation ratio of the ceramic dielectric powder to the matrix resin is adjusted appropriately so that the resin composition constituting the insulator has a dielectric constant determined at 25xc2x0 C. and 1 MHz of approximately 5 to 20, in many cases, approximately 7 to 15. Here, the upper limit of the dielectric constant is restricted due to the increase in signal loss and to the deterioration of moldability caused by the incorporation of a great amount of ceramic dielectric powder.
The dielectric constant is to be set appropriately depending on the material, shape and the like of other parts constituting the insulator and the connector. However, the setting of the dielectric constant of the resin composition constituting the insulator to such a high value that can hardly be thought of with the conventional insulators (dielectric constant of approximately 2.0 to 4.5) can establish impedance matching while signal loss is controlled. Furthermore, to cause the insulator to have a capacitance is conducible to the control of crosstalk.
The relationship between the amount (V0) of the ceramic dielectric powder incorporated and the dielectric constant (xcex50) of the resin composition can be approximated with the following formula (1) using the dielectric constant (xcex51) of the ceramic dielectric powder and the dielectric constant (xcex52) of the matrix resin:
log xcex50=V0xc2x7log xcex51+(1xe2x88x92V0)xc2x7log xcex52xe2x80x83xe2x80x83(1)
Using the above formula (1), the amount (V0) of the ceramic dielectric powder required to be incorporated for the setting of a desired dielectric constant xcex50.
Molding can be performed by injection molding, transfer molding, press molding, etc.
The manufacture of the connector of the present invention can be performed by combining an obtained insulator with other parts of a contact, or by integrally molding by insert molding while placing, in advance, a conductive element in the mold during the molding process of the insulator.
The connector of the present invention may be used by being combined with a variety of techniques which have conventionally be proposed. Furthermore, the connector may be combined with a technique of shielding around a insulator with a shielding member as needed.
The optimal design of the connector of the present invention can be established through a test small production performed prior to a mass production, followed by the measurement of the characteristic impedances of the respective resulting test connectors performed with the connectors installed in an instrument to be adopted, followed by appropriate varying of the amount of a dielectric powder based on the results of the measurement.
In other words, the relationship between the dielectric constant (xcex50) and the impedance (Z0) can be approximated by the following formula (2) using a constant K which is determined from the shape of the insulator, the shape of the connector and the conditions of the circuit to be connected to the connector, and therefore, adjustment can be done so that the dielectric constant is made lower for increasing the characteristic impedance and that the dielectric constant is made higher for reducing the characteristic impedance.
Z0=K/xcex501/2xe2x80x83xe2x80x83(2)
Such a characteristic impedance is under the influence of the shape of a connector, the circuit to be connected, a circuit disposed therearound and the like. In the design of the conventional precision connectors, therefore, a characteristic impedance adjustment requires to form and modify a mold two or more times, resulting in the necessity of a long time for launching products. On the other hand, in the connector of the present invention, impedance matching can be established easily by the adjustment of the composition of the resin composition with the shape of the insulator and the shape of the conductor portion itself unchanged, resulting in the saving of time required for the conventional formation and modification of molds and also permitting a great reduction of a time required until the beginning of the production of products.
Moreover, by varying the mixing compositions, insulators having the same shape formed with the identical mold can be produced for use in circuits corresponding to different impedances.
Furthermore, since the shape of an insulator or a connector can be designed relatively freely according to the present invention, the shape of the connector can be changed freely depending upon the requirement on the scaling down and packaging of instruments.
The connector of the present invention may be either of the type where it is mounted directly to a substrate or of the type where it is connected to a cable. The connector can be used for various applications such as interconnection between a plurality of circuit boards, interconnection between a plurality of devices, interconnection between connectors and circuit boards, interconnection between connectors, and integrated circuit sockets such as CPU sockets.