具体实施方式：
[0025]Referring to the drawings, wherein like reference numerals are used to identify like or identical components in the various views, FIG. 1 schematically illustrates a golf ball 10 that includes a thermoplastic core 12, and a cover 14 surrounding the core 12. While the illustrated ball 10 has a two-piece construction (i.e., core 12 and cover 14), in other embodiments, the ball 10 may be a three or more piece construction, with additional intermediate layers (including, for example, a cross-linked thermoset layer) disposed between the cover 14 and the core 12. In the two-piece embodiment illustrated, the core 12 may have a diameter of, for example, from about 22 mm to about 42 mm. In a three-piece ball, the core 12 may have a diameter of, for example, from about 22 to about 32 mm. It should be noted that for the purposes of this description, if one layer “radially surrounds” another layer (such as the cover radially surrounding the core), it should not be inferred that the two layers are necessarily in contact, as other intermediate layers may be disposed in between.
[0026]In general, the cover 14 may define an outermost portion 16 of the ball 10, and may include any desired number of dimples 18, including, for example, between 280 and 432 total dimples, and in some examples, between 300 and 392 total dimples, and typically between 298 to 360 total dimples. As known in the art, the inclusion of dimples generally decreases the aerodynamic drag of the ball, which may provide for greater flight distances when the ball is properly struck.
[0027]In a completely assembled ball 10, the cover 14 may be substantially concentric with the core 12 such that they share a common geometric center. Additionally, the mass distribution of the cover 14 and core 12 may be uniform such that their respective centers of mass, and the center of mass for the ball 10 as a whole, is coincident with the geometric center.
[0028]The cover 14 may generally be formed from a thermoplastic material that may be either compression molded or injection molded about the core 12. In one configuration, the cover 14 may be formed from a thermoplastic polyurethane that may have a flexural modulus of up to about 1000 psi. In other embodiments, the cover 14 may be formed from a ionomer, such as commercially available from the E. I. du Pont de Nemours and Company under the tradename Surlyn®. When a thermoplastic polyurethane is used, the cover 14 may have a hardness measured on the Shore-D hardness scale of up to about 65, measured on the ball. In other embodiments, the thermoplastic polyurethane cover may have a hardness measured on the Shore-D hardness scale of up to about 60, measured on the ball. If other ionomers are used to form the cover layer, the cover may have a hardness measured on the Shore-D hardness scale of up to about 72, measured on the ball.
[0029]The core 12 may be formed using a 3D printing process, and may have a composition that varies as a function of a radial dimension. In general, 3D printing is an additive part-forming technique that incrementally builds an object by applying a plurality of successive thin material layers. FIG. 2 schematically illustrates one embodiment of a 3D printer 20 that may be used to form the core 12, which employs a 3D printing technique known as fused filament fabrication.
[0030]In general, a 3D printer 20 includes a print head 22 configured to controllably deposit/bind a stock material 24 onto a substrate 26, and motion controller 28 that is configured to controllably translate a print head 22 within a predefined workspace. In fused filament fabrication, the print head 22 may be configured to receive the solid stock material 24 from a source such as a spool 30 or hopper, melt the stock material 24 (e.g., using a resistive heating element 32), and expel the molten stock material 24 onto the substrate 26 via a nozzle 34. In general, the nozzle 34 may define an orifice 36 at its distal tip 38 through which the molten material 24 may exit the print head 22.
[0031]Once out of the nozzle 34, the molten stock material 24 may begin cooling, and may re-solidify onto the substrate 26. The substrate 26 may either be a work surface 40 that serves as a base for the object, or may be a previously formed/solidified material layer 42. In the case where the molten stock material 24 is applied over a previously formed material layer 42, the temperature of the molten stock material 24 may cause localized surface melting to occur in the previously formed material layer 42. This localized melting may aid in bonding the newly applied material with the previously formed layers 42.
[0032]In one configuration, the print head 22 may be controlled within a Cartesian coordinate system 44, where three actuators can each cause a resultant motion of the print head in a respective orthogonal plane (where convention defines the X-Y plane as a plane parallel to the work surface 40, and the Z-direction as a dimension orthogonal to the work surface 40). In another configuration, such as shown in FIG. 3, the 3D printer 20 may be natively controllable in a spherical coordinate system (i.e., a radial position, a polar angle, and an azimuth angle (r, θ, φ)). In either configuration (i.e., Cartesian control or spherical control), the core 12 may be formed by printing a plurality of shells of increasing size to build up a solid hemisphere or sphere.
[0033]To accomplish the spherical control, the illustrated 3D printer 20 includes an arcuate track 50 that is configured to support a movable carriage 52. The arcuate track 50 is generally disposed within a track plane that is orthogonal to the work surface 40. Additionally, the track 50 may have a constant radius of curvature 56 that extends from a point 58 disposed on the adjacent work surface 40.
[0034]The movable carriage 52 is supported on the arcuate track 50 using, for example, one or more wheel, bearing, or bushing assemblies that may allow it to smoothly translate along the track 50. A first motor 60 and drive mechanism may be associated with the carriage 52 and/or track 50 to controllably translate and/or position the carriage 52 along the track 50. In general, the carriage's position along the track may form an azimuth angle 62 relative to an axis 64 that is normal to the work surface 40. The drive mechanism may include, for example, a chain or belt extending within one or more track elements, or a rack and pinion-style gear drive.
[0035]The carriage 52 may movably support an extension arm 66, which may, in turn, support the print head 22. The extension arm 66 may controllably translate relative to the carriage 52 to effectuate a radial movement of the print head 22. In one configuration, the extension arm 66 may translate in a longitudinal direction using, for example, a second motor 68 that is associated with the carriage 52. The second motor 68 may be configured to drive a rack and pinion-style gear arrangement, a ball screw, or lead screw that may be associated with the extension arm 66. The translation of the extension arm 66 may control a radial position 70 of the print head 22.
[0036]The motion controller 28 may be in electrical communication with both the first motor 60 and the second motor 68 to respectively control the azimuth angle 62 and radial positioning 70 of the print head 22. The motion controller 28 may be embodied as one or multiple digital computers, data processing devices, and/or digital signal processors (DSPs), which may have one or more microcontrollers or central processing units (CPUs), read only memory (ROM), random access memory (RAM), electrically-erasable programmable read only memory (EEPROM), high-speed clock, analog-to-digital (A/D) circuitry, digital-to-analog (D/A) circuitry, input/output (I/O) circuitry, and/or signal conditioning and buffering electronics. The motion controller 28 may further be associated with computer readable non-transitory memory having stored thereon a numerical control program that specifies the positioning of the print head 22 relative to the work surface 40 in spherical coordinates.
[0037]While the azimuth angle 62 and radial positioning 70 of the print head 22 may be controlled by motors 60, 68, the polar angle may be controlled through either a rotation of the track relative to the work surface 40, or through a rotation of the work surface 40 relative to the track 50.
[0038]In one configuration, the 3D printer 20 (whether controlled in spherical coordinates, Cartesian coordinates, or through another manner of control) may build up a or spherical solid by printing a plurality of concentric shells/layers at incrementing radial distances. In one configuration, these shells may be generally, however, more unique geometries may also be created by interspersing one or more voids or material inlays within a shell layer. In one configuration, each shell layer may be formed from a plurality of rings of material that are each at a different azimuth angle 62 between 90 degrees and 0 degrees. In another configuration, each shell layer may be formed from a plurality of arcs of material that extend away from the work surface 40 (e.g., in an X-Z plane, with the arcs increment along the Y-axis).
[0039]Referring again to FIG. 2, in one configuration, the print head 22 may receive the solid stock material 24 in the form of a thermoplastic filament 80 that is drawn into the print head 22 by a feed mechanism 82. The feed mechanism 82 may include, for example, a pair of wheels 84 disposed on opposite sides of the filament 80 that may controllably rotate in opposing directions (and at approximately equal edge velocities).
[0040]Once in the print head 22, the stock material 24 may pass by a heating element 86 (i.e., a primary heating element 86) that may melt the thermoplastic. In one configuration, the primary heating element 86 may be located within a body portion 88 of the print head, and may include, for example, a resistive heating element.
[0041]While FIG. 2 illustrates a print head 22 capable of printing a single material, FIGS. 4-6 schematically illustrate three different print heads 100, 102, 104, which are each capable of forming a solid object that is a blend of two different polymers. As shown, each embodiment 100, 102, 104 includes a first feed mechanism 110 and a second feed mechanism 112 that are each respectively configured to continuously draw material into the print head. Each feed mechanism 110, 112 is respectively configured to receive a different stock material 114, 116 that may be obtained, for example from a different material spool. The total flow of the molten material through the orifice 36 would then be the sum of the material received by the respective feed mechanisms 110, 112. The feed mechanisms 110, 112 may therefore be controlled by specifying the desired composition ratio and the desired output flow rate.
[0042]The first and second feed mechanisms 110, 112 may be individually controlled, for example, via a feed controller 120, such as shown in FIG. 4. In one configuration, the feed controller 120 may be integrated with the motion controller 28 described above, where the numerical control program that specifies print head motion is further used to specify the respective feed rates. Each feed mechanism 110, 112 may include, for example, a respective motor 122, 124 that may be used to drive the feed wheels 84 in opposing directions (e.g., through one or more gears or similar force transfer elements). In one configuration, the motors 122, 124 may have an annular in shape, where the filament may pass through a hollow core 126.
[0043]As each respective filament enters the body portion 88 of the print head 100, it may be melted by a respective primary heating element 128. In one configuration, each filament may have a different primary heating element that, for example, may be able to adjust its thermal output according to the feed rate and melting point of the respective filament. In another configuration, both primary heating elements 128 may be interconnected such that they both output a similar amount of thermal energy. The primary heating elements 128 may include, for example, a resistive wire, film, or strip that may be wrapped around a material passageway within the body portion 88 of the print head 100.
[0044]Once past the primary heating element, the molten materials may enter a mixing cavity 130 that may be partially or entirely disposed within the nozzle 34. In one configuration, such as shown in FIG. 4, the mixing cavity 130 may be a smooth sided cylinder, where the molten materials may mix by virtue of their converging flow paths. In a slight variant on the entirely smooth-sided design, the entrance to the mixing cavity 130 (i.e., where the two flow paths converge) may define a nozzled portion that increases flow turbulence to further facilitate mixing of the two materials.
[0045]In yet another configuration, such as generally shown in FIG. 5, the mixing cavity 130 may include one or more surface features to promote increased mixing. For example, the mixing cavity 130 may include internal threads 132 along a portion or along the entire length. The internal threads 132 (or other mixing features) may serve to passively agitate and/or mix the molten materials as they pass toward the orifice 36. In this manner, the geometry of the mixing cavity may aid in providing a homogeneous mixture of the two stock materials.
[0046]In another configuration, the two molten materials may be mixed using an active means. For example, as shown in FIG. 6, a power screw 134 may be disposed within the mixing cavity 130 to actively mix the two materials together. The power screw 134 (or other mixing element) may be either driven by a separate, mixing motor 136, or by one or both of the motors that are responsible for feeding the stock materials into the print head. In addition to providing a mixing effect, the power screw may also aid the material mixture in flowing through the nozzle. While FIGS. 4-6 only show print head embodiments that include two feeder mechanisms, these designs may easily be expanded to three or more feeder mechanisms to suit the required application. Additional detail and embodiments of a 3D printer configured to print a solid hemisphere via a plurality of printed shells is found in co-filed U.S. Patent Application Publication No. US 2015/0183161, entitled “3D Print Head,” which is hereby incorporated by reference in its entirety.
[0047]In one configuration, a golf ball core 12 may be formed by individually printing two polymeric core portions/hemispheres, and subsequently fusing them together to form a solid sphere. For example, as shown in FIG. 7A a 3D printer may begin by forming a solid object 140, via a plurality of layers 142. Each layer 142 may be formed by molding a plurality of discrete rings 144 or arcs in an arrangement that collectively forms a shell.
[0048]Once two identical hemispheres 150, 152 are formed, they may be fused or molded together, such as schematically illustrated in FIGS. 7B and 7C. As shown in FIG. 7B, a pair of opposing mold halves 154, 156 may cooperate to define a spherical recess 158 that has a diameter about equal to the diameter of the hemispheres 150, 152. The hemispheres 150, 152 may be inserted within the spherical recess 158, upon which the mold halves 154, 156 may be brought together and heated to a temperature that is at or above the melting point of the polymeric hemispheres 150, 152. The application of heat may soften and/or partially melt the hemispheres 150, 152 as the polymer is heated by the mold. Once the hemispheres 150, 152 are brought to an appropriate temperature, the mold may be allowed to cool (or may be actively cooled), which may resolidify/harden the polymer, resulting in the hemispheres 150, 152 being fused together to form a sphere. In one configuration, this process may further involve compression molding an intermediate layer about the core, where the heat of the compression molding process fuses the hemispheres 150, 152 together. In other embodiments, the halves may be fused together through other methods of joining, such as spin welding, ultrasound welding, or laser welding.
[0049]In another configuration, such as shown in FIGS. 8A-8C, the 3D printer 20 may form the core 12 by directly printing an outer-core material 170 onto a pre-formed inner core 172. In this method, an inner core 172 may first be formed using a molding technique such as injection molding, compression molding, or casting. The inner core 172 may then be placed into a recess 174 in the otherwise planar work surface 40. The recess 174 may have a diameter about equal to the diameter of the inner core 172. The 3D printer 20 may then print a first outer core portion 176 onto the inner core 172, such as shown in FIG. 8A.
[0050]Once the first outer-core portion 176 is formed, the partially formed core assembly 178 may be flipped and the outer core portion 176 may be inserted into a second recess 180 in the work surface 40 (such as shown in FIG. 8B). The 3D printer 20 may then complete the assembly of the core 12 by printing a second core portion 182 (identical to the first outer core portion 176) onto the partially formed core assembly 178, such as shown in FIG. 8C.
[0051]Therefore, as generally described in relation to FIGS. 7A-7C and 8A-8C, the golf ball core 12 may be formed by printing a first core portion and printing a second. Each respective core portion may include a respective plurality of concentric shells. The process may also include fusing the first core portion with the second core portion to form the core. As shown in FIG. 7A-7C, this may involve a distinct process, such as fusing via a heated mold, or, as shown in FIGS. 8A-8C, the fusing may occur by virtue of printing the second core portion directly onto the first core portion (i.e., where the molten material may temporarily melt a localized portion of the first core portion to cause a the two portions to be fused together).
[0052]3D printing may have certain definite advantages over other molding/forming techniques such as injection molding or compression molding. In particular, when using multi-filament capable print heads, such as schematically illustrated in FIGS. 4-6, 3D printing may provide an economical and method of creating a core 12 with a variable material composition.
[0053]FIG. 9 generally illustrates a graph 200 of material composition 202 of one possible two-material core as a function of the radial position 204 (where material composition 212 is measured on a percentage basis between 0% and 100%). As shown, the 3D printer may vary the composition with each successive shell such that the innermost portion 206 of the hemisphere is entirely made from a first material 208, the outermost portion 210 of the hemisphere is entirely made from a second material 212, and an intermediate portion 214 is formed from a varying blend of the first material 208 and the second material 212. In one configuration, the curves may have a slightly stair-stepped appearance that may be attributable to the discrete thicknesses of the varying layers. Once formed in this manner, it is possible for the material composition to achieve an even smoother gradient using one or more post-processing procedures such as heat-treating, which may soften and/or melt the layers to cause localized diffusion (e.g., during the fusion of the hemispheres such as shown in FIG. 7B-7C). In one golf ball core configuration, the printed layer thickness may be from about 0.1 mm to about 2 mm, or from about 0.1 mm to about 1.2 mm, and the total number of shells/layers may be from about 9 to about 200 or more (i.e., per hemisphere). In another embodiment, the printed layer thickness may be less than 0.1 mm, such as from about 0.01 mm to about 0.1 mm; however, using such thicknesses may present a manufacturing hurdle, as production speed and printing resolution are inversely proportional. To provide a suitable balance of speed vs. resolution, the layer thickness may be from about 0.4 mm to about 1.2 mm, and the total number of layers may be from about 9 to about 55.
[0054]FIG. 10 generally illustrates a graph 220 of the material composition 202 of one possible three-material core as a function of the radial position 204. This graph 220 is similar to the graph 200 provided in FIG. 9, except that a third, transition material 222 has been included within the intermediate portion 214.
[0055]While it is common to construct a golf ball by radially stacking three to five discrete material layers (e.g., by overmolding or compression molding the layers in succession), multi-material 3D printing allows for a more gradual transition/gradient, rather than a discrete boundary. In a conventional, discrete-layered multi-piece or multi-layer ball design, each layer may have the tendency to react differently to the stress imparted by an impact. In particular, due to the varying characteristics of the materials used, the stress/strain response of the ball may be non-uniform/non-linear across the ball, particularly at the boundaries between different materials. These non-uniformities may result in the occurrence of stress concentration points during an impact, which, over time, may degrade the performance of the golf ball 10. The more gradual transition presented through 3D printing may make the boundary effects less apparent.
[0056]In addition to causing stress concentration points, the existence of discrete material boundaries may also result in non-uniform stress propagation during the impact. That is, during an impact, forces imparted to the ball may initially be localized at the point of impact. Over a short period of time (e.g., less than 500 μs), these stresses may propagate throughout the ball, where they are eventually converted into other forms of energy and/or dissipated. This stress propagation may be viewed as a pressure wave that induces one or more dynamic viscoelastic deformations, including vibrational modes, of the golf ball 10. The viscoelastic dissipation that dampens any acoustic waves may have an effect on the acoustic response of the ball to a player, and the viscoelastic responses to the impact stress may have an effect on the response of the ball during and after the impact.
[0057]By blending the transition zones and eliminating stark, discrete boundary interfaces, the efficiency of the force transmission between the different materials and/or portions of the ball is increased, and the amount of energy that is dissipated at impact is correspondingly decreased.
[0058]In another embodiment, the various layers that are printed may include discontinuities, or voids that may either remain unfilled (i.e., as pockets of air within the ball), or may be filled with another material. Said another way, at least one layer may be discontinuous, meaning that it is not formed from a single, homogeneous material composition; instead, it may include one or more voids (filled or unfilled) disposed through the shell. With a filled void, the filler material may be either printed in place, or may be filled through an overmolding process, such as injection molding. The use of strategically placed voids through one or more layers may be used to change the structural, acoustic, or dynamic properties of the ball.
[0059]The use of one or more discontinuous shell layers may be employed, for example, to form a core having a varying surface geometry. For example, the above-described 3D printing techniques may be used to form a core having a surface geometry such as disclosed in U.S. patent application Ser. No. 13/935,953, filed on Jul. 5, 2013 to Ishii et al. and entitled “Multi-layer Golf Ball,” which is hereby incorporated by reference in its entirety, or such as generally disclosed in U.S. patent application Ser. No. 13/935,977, filed on Jul. 5, 2013 to Ishii et al. and entitled “Multi-layer Golf Ball,” which is hereby incorporated by reference in its entirety, or in U.S. patent application Ser. No. 13/935,944, filed on Jul. 5, 2013 to Ishii et al. and entitled “Multi-layer Golf Ball,” which is hereby incorporated by reference in its entirety. In yet another embodiment, a spherical center portion may be initially formed through, for example, injection molding, compression molding, or casting, and a varying surface geometry, such as those disclosed above, may be printed directly onto the pre-formed spherical center portion. Such a technique may permit more aggressive surface geometries than would otherwise be capable through simple injection molding (i.e., where mold undercut may prohibit the finished part from being ejected from the finished mold if the features/channels were too deep).
Materials
[0060]As noted above, the core may be printed from a blend of two or more thermoplastic materials, each of which have been drawn or extruded into a suitable filament form. The thermoplastic materials may be elastomeric or nonelastomeric (rigid or engineering) thermoplastics. These may be used in any combination, including a blend of two or more elastomeric thermoplastic materials, a blend of two or more nonelastomeric or rigid thermoplastic materials, or a blend of at least one elastomeric thermoplastic material and at least one nonelastomeric or rigid thermoplastic material.
[0061]Nonlimiting examples of suitable thermoplastic elastomers that can be blended to form the printed core include metal cation ionomers of addition copolymers of ethylenically unsaturated acids (“ionomer resins”), metallocene-catalyzed block copolymers of ethylene and α-olefins having 4 to about 8 carbon atoms, thermoplastic polyamide elastomers (PEBA or polyether block polyamides), thermoplastic polyester elastomers, thermoplastic styrene block copolymer elastomers such as poly(styrene-butadiene-styrene), poly(styrene-ethylene-co-butylene-styrene), and poly(styrene-isoprene-styrene), thermoplastic polyurethane elastomers, thermoplastic polyurea elastomers, and dynamic vulcanizates of rubbers in these thermoplastic elastomers and in other thermoplastic matrix polymers.
[0062]Nonlimiting examples of suitable nonelastomeric thermoplastic materials include acrylic polymers (also called polyacrylates); other vinyl polymers and copolymers including acrylonitirile-butadiene-sytrene copolymer (ABS), styrene-acrylonitrile (SAN), olefin-modified SAN, acrylonitrile-styrene-acrylonitrile, styrene-maleic anhydride (S/MA) polymer, polyvinyl alcohol (PVOH), ethylene vinyl acetate copolymers (EVA); ethylene methyl acrylates; polyvinyl chloride resins, and maleic anhydride grafted polymers; polycarbonates; nonelastomeric polyesters, polyamides, polyurethanes, polyureas, and polyurethane-polyurea copolymers; polyimides, polyphenylene ethers, polyphenylene sulfides, polysulfones, polyphenylsulfones, polyamide-imides, impact-modified polyphenylene ethers, high impact polystyrenes, diallyl phthalate polymers, polyetheretherketones (PEEK), and polyolefins such as polypropylene and high density polyethylene.
[0063]Ionomer resins, which are metal cation ionomers of addition copolymers of ethylenically unsaturated acids, are preferably alpha-olefin, particularly ethylene, copolymers with C3 to C8 α,β-ethylenically unsaturated carboxylic acids, particularly acrylic or methacrylic acid. The copolymers may also contain a softening monomer such as an alkyl acrylate or methacrylate, for example a C1 to C8 alkyl acrylate or methacrylate ester. The α,β-ethylenically unsaturated carboxylic acid monomer may be from about 4 weight percent or about 6 weight percent or about 8 weight percent up to about 20 weight percent or up to about 35 weight percent of the copolymer, and the softening monomer, when present, is preferably present in a finite amount, preferably at least about 5 weight percent or at least about 11 weight percent, up to about 23 weight percent or up to about 25 weight percent or up to about 50 weight percent of the copolymer.
[0064]Nonlimiting specific examples of acid-containing ethylene copolymers include copolymers of ethylene/acrylic acid/n-butyl acrylate, ethylene/methacrylic acid/n-butyl acrylate, ethylene/methacrylic acid/isobutyl acrylate, ethylene/acrylic acid/isobutyl acrylate, ethylene/methacrylic acid/n-butyl methacrylate, ethylene/acrylic acid/methyl methacrylate, ethylene/acrylic acid/methyl acrylate, ethylene/methacrylic acid/methyl acrylate, ethylene/methacrylic acid/methyl methacrylate, and ethylene/acrylic acid/n-butyl methacrylate. Preferred acid-containing ethylene copolymers include copolymers of ethylene/methacrylic acid/n-butyl acrylate, ethylene/acrylic acid/n-butyl acrylate, ethylene/methacrylic acid/methyl acrylate, ethylene/acrylic acid/ethyl acrylate, ethylene/methacrylic acid/ethyl acrylate, and ethylene/acrylic acid/methyl acrylate. In various embodiments the most preferred acid-containing ethylene copolymers include ethylene/(meth)acrylic acid/n-butyl acrylate, ethylene/(meth)acrylic acid/ethyl acrylate, and ethylene/(meth)acrylic acid/methyl acrylate copolymers.
[0065]The ionomer resin may be a high acid ionomer resin. In general, ionomers prepared by neutralizing acid copolymers including at least about 16 weight % of copolymerized acid residues based on the total weight of the unneutralized ethylene acid copolymer are considered “high acid” ionomers. In these high modulus ionomers, the acid monomer, particularly acrylic or methacrylic acid, is present in about 16 to about 35 weight %. In various embodiments, the copolymerized carboxylic acid may be from about 16 weight %, or about 17 weight % or about 18.5 weight % or about 20 weight % up to about 21.5 weight % or up to about 25 weight % or up to about 30 weight % or up to about 35 weight % of the unneutralized copolymer. A high acid ionomer may be combined with a “low acid” ionomer in which the copolymerized carboxylic acid is less than 16 weight % of the unneutralized copolymer.
[0066]The acid moiety in the ethylene-acid copolymer is neutralized by any metal cation. Suitable preferred cations include lithium, sodium, potassium, magnesium, calcium, barium, lead, tin, zinc, aluminum, or a combination of these cations; in various embodiments alkali metal, alkaline earth metal, or zinc cations are particularly preferred. In various embodiments, the acid groups of the ionomer may be neutralized from about 10% or from about 20% or from about 30% or from about 40% to about 60% or to about 70% or to about 75% or to about 80% or to about 90%. In various embodiments, the third thermoplastic material includes a high acid monomer neutralized from about 10% or from about 20% or from about 30% or from about 40% to about 60% or to about 70% or to about 75% or to about 80% or to about 90%.
[0067]A sufficiently high molecular weight, monomeric organic acid or salt of such an organic acid may be added to the acid copolymer or ionomer so that the acid copolymer or ionomer can be neutralized, without losing processability, to a level above the level that would cause the ionomer alone to become non-melt-processable. The high-molecular weight, monomeric organic acid its salt may be added to the ethylene-unsaturated acid copolymers before they are neutralized or after they are optionally partially neutralized to a level between about 1 and about 100%, provided that the level of neutralization is such that the resulting ionomer remains melt-processable. In generally, when the high-molecular weight, monomeric organic acid is included the acid groups of the copolymer may be neutralized from at least about 40 to about 100%, preferably from at least about 90% to about 100%, and most preferably 100% without losing processability. Such high neutralization, particularly to levels greater than 80%, greater than 90% or greater than 95% or most preferably 100%, without loss of processability can be done by (a) melt-blending the ethylene α,β-ethylenically unsaturated carboxylic acid copolymer or a melt-processable salt of the copolymer with an organic acid or a salt of organic acid, and (b) adding a sufficient amount of a cation source up to 110% of the amount needed to neutralize the total acid in the copolymer or ionomer and organic acid or salt to the desired level to increase the level of neutralization of all the acid moieties in the mixture preferably to greater than 90%, preferably greater than 95%, or preferably to 100%. To obtain 100% neutralization, it is preferred to add a slight excess of up to 110% of cation source over the amount stoichiometrically required to obtain the 100% neutralization.
[0068]The high molecu