Blends of thermoplastic polyurethane and ethylene vinyl acetate copolymer

Abstract

The present invention relates to an elastomeric composition comprising: about 10% to 85% by weight of an ethylene-vinyl acetate copolymer, optionally based on ethylene produced from a bio-based carbon source; about 15% to 90% by weight of a thermoplastic polyurethane; and about 0% to 10% by weight of a compatibilizer. The present invention also relates to a molded article produced from the elastomeric composition.

Description

[0001] Priority declaration

[0002] This application claims priority to U.S. Provisional Application No. 62 / 746,914, filed on October 17, 2018, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to an elastomeric composition comprising a thermoplastic polyurethane component and an ethylene vinyl acetate component. Background Art

[0004] Thermoplastic polyurethanes are used in sporting goods due to their beneficial properties such as high abrasion resistance, high shear strength and high elasticity. Despite these favorable properties, the sports footwear industry has been looking for more environmentally friendly materials. Partially bio-based thermoplastic polyurethanes have been developed for use in certain commercial sports shoes. However, many commercially available bio-based thermoplastic polyurethanes have a bio-based content of only about 30%.

[0005] Therefore, there remains a need in the art to develop an environmentally sustainable elastomeric composition having a higher bio-based carbon content than an elastomeric composition based on pure thermoplastic polyurethane while maintaining comparable or better performance than an elastomeric composition based on pure thermoplastic polyurethane. Summary of the invention

[0006] One aspect of the present invention relates to an elastomeric composition comprising: about 10 wt % to 85 wt % of an ethylene-vinyl acetate copolymer, about 15 wt % to 90 wt % of a thermoplastic polyurethane, and about 0 wt % to 10 wt % of a compatibilizer. The ethylene-vinyl acetate copolymer may be based on ethylene produced from a bio-based carbon source.

[0007] Another aspect of the present invention relates to a molded article formed from an elastomeric composition comprising: about 10 wt % to 85 wt % of an ethylene-vinyl acetate copolymer, about 15 wt % to 90 wt % of a thermoplastic polyurethane, and about 0 wt % to 10 wt % of a compatibilizer, wherein the ethylene-vinyl acetate copolymer is optionally based on ethylene produced from a bio-based carbon source.

[0008] Another aspect of the present invention relates to an elastomeric composition comprising: about 10 wt % to 85 wt % of ethylene-vinyl acetate copolymer, about 15 wt % to 90 wt % of thermoplastic polyurethane and about 0 wt % to 10 wt % of a compatibilizer. The melting point of the elastomeric composition is at least 200° C. The tensile modulus of the elastomeric composition is at least 20 MPa.

[0009] Another aspect of the present invention relates to a molded article formed from an elastomeric composition comprising: about 10 wt % to 85 wt % of an ethylene-vinyl acetate copolymer, about 15 wt % to 90 wt % of a thermoplastic polyurethane, and about 0 wt % to 10 wt % of a compatibilizer, wherein the elastomeric composition has a melting point of at least 200° C. and a tensile modulus of at least 20 MPa.

[0010] By reading the following, other aspects, advantages and features of the invention proposed in this specification will become apparent to those skilled in the art, or can be learned by practicing the invention. The invention disclosed in this application is not limited to any specific set or combination of aspects, advantages and features. It is expected that various combinations of the aspects, advantages and features constitute the invention disclosed in this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Results of melting peak temperature and crystallization peak temperature of elastomeric compositions comprising blends of a thermoplastic polyurethane (TPU) component and an ethylene vinyl acetate (EVA) component having TPU / EVA weight ratios of 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, 85 / 15 and 100 / 0 (i.e., pure TPU), respectively.

[0012] Figure 2 Shown are melt viscosity |η*| values ​​of elastomeric compositions comprising blends of a TPU component and an EVA component having TPU / EVA weight ratios of 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, and 85 / 15, respectively.

[0013] Figure 3 Shown are tan delta values ​​for elastomeric compositions comprising blends of a TPU component and an EVA component having TPU / EVA weight ratios of 30 / 70, 45 / 55, 55 / 45, and 70 / 30, respectively.

[0014] Figure 4 The tan δ values ​​of elastomeric compositions comprising a blend of a TPU component and an EVA component in a TPU / EVA weight ratio of 70 / 30 and a compatibilizer (organic peroxide, E-MA-GMA terpolymer or SA-epoxy, respectively) are shown, compared to the tan δ values ​​of the same compositions without a compatibilizer.

[0015] Figure 5The tensile elongation results for elastomeric compositions comprising blends of a TPU component and an EVA component having TPU / EVA weight ratios of 0 / 100 (i.e., neat EVA), 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, 85 / 15, and 100 / 0 (i.e., neat TPU), respectively, are shown.

[0016] Figure 6 The tensile stress at break results are shown for elastomeric compositions comprising blends of a TPU component and an EVA component having TPU / EVA weight ratios of 0 / 100, 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, 85 / 15 and 100 / 0, respectively.

[0017] Figure 7 The tensile modulus results are shown for elastomeric compositions comprising blends of a TPU component and an EVA component having TPU / EVA weight ratios of 0 / 100, 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, 85 / 15 and 100 / 0, respectively.

[0018] Figure 8 Tensile strain-hardening results are shown for elastomeric compositions comprising blends of a TPU component and an EVA component having TPU / EVA weight ratios of 0 / 100, 70 / 30, 85 / 15, and 100 / 0, respectively.

[0019] Fig. 9 The tensile elongation results of an elastomeric composition comprising a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30 and a compatibilizer (organic peroxide (blend + OP); E-MA-GMA terpolymer (blend + E-MA-GMA); or SA-epoxy (blend + SA-epoxy) respectively) are shown, compared with the tensile elongation results of a control (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using EVA containing about 19% vinyl acetate content, without a compatibilizer) and a high VA (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using EVA containing about 28% vinyl acetate content, without a compatibilizer).

[0020] Fig.10The tensile stress at break results for an elastomeric composition comprising a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30 and a compatibilizer (an organic peroxide; an E-MA-GMA terpolymer; or a SA-epoxy, respectively) are shown, compared with the tensile elongation results for a control (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 19%, without a compatibilizer) and a high VA (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 28%, without a compatibilizer).

[0021] Fig.11 The tensile modulus results for an elastomeric composition comprising a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30 and a compatibilizer (an organic peroxide; an E-MA-GMA terpolymer; or a SA-epoxy, respectively) are shown, compared with the tensile elongation results for a control (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 19%, without a compatibilizer) and a high VA (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 28%, without a compatibilizer). DETAILED DESCRIPTION

[0022] The present invention relates to an elastomeric composition comprising a thermoplastic polyurethane (TPU) component and an ethylene vinyl acetate (EVA) component, both of which optionally have a bio-based carbon content. The elastomeric composition has a higher melting point and improved tensile properties compared to the same elastomeric composition without the EVA component.

[0023] One aspect of the present invention relates to an elastomeric composition comprising: about 10 wt % to 85 wt % of an ethylene-vinyl acetate copolymer, about 15 wt % to 90 wt % of a thermoplastic polyurethane, and about 0 wt % to 10 wt % of a compatibilizer. The ethylene-vinyl acetate copolymer may be based on ethylene produced from a bio-based carbon source.

[0024] Another aspect of the present invention relates to an elastomeric composition comprising: about 10 wt % to 85 wt % of ethylene-vinyl acetate copolymer, about 15 wt % to 90 wt % of thermoplastic polyurethane and about 0 wt % to 10 wt % of a compatibilizer. The melting point of the elastomeric composition is at least 200° C. The tensile modulus of the elastomeric composition is at least 20 MPa.

[0025] EVA copolymers are also known as poly(ethylene-vinyl acetate) (PEVA), which are copolymers of ethylene and vinyl acetate. EVA copolymers can have Structure. Any type of EVA copolymer known to those skilled in the art is suitable for use herein. For example, three typical types of EVA copolymers, which differ in vinyl acetate (VA) content and material usage, include those based on low VA content (up to about 4%) processed as thermoplastic materials, those based on medium VA content (about 4% to 30%) processed as thermoplastic elastomer materials, and those based on high VA content (greater than 33% or even greater than 40%) used as ethylene-vinyl acetate rubbers, all of which are suitable for use herein.

[0026] The VA content in the EVA copolymer is generally about 2% by weight to about 40% by weight, with the remainder being ethylene content. For example, the VA content in the EVA copolymer can be in the range of about 2% by weight to about 35% by weight, about 12% by weight to about 33% by weight, about 15% by weight to about 30% by weight.

[0027] As used herein, the term "biobased" refers to materials that have a portion of their carbon content derived from biological materials or agricultural resources rather than from fossil carbon resources.

[0028] Suitable EVA copolymers include those of bio-based. The bio-based carbon content of EVA copolymers is usually from ethylene components. Bio-based ethylene (or renewable ethylene) is usually made of ethanol, and ethanol becomes ethylene after a dehydration process. Ethanol can be produced by any plant-based material. For example, ethanol can be produced by fermenting starch or sugar from various bio-based raw materials (including but not limited to corn, sugar cane, beet, wheat grain, etc.). Ethanol can also be produced by enzyme decomposition of various cellulose raw materials (such as grass, wood, algae or other plants).

[0029] There are many advantages to using bio-based ethylene in EVA copolymers. One benefit is that the EVA copolymers produced in this way are green and environmentally friendly. For example, for every ton of green polyethylene produced, about 2.15 tons of CO2 can be sequestered, which comes from the CO2 absorbed when the sugar cane grows minus the CO2 emitted during the production process. The bio-based ethylene in EVA copolymers can also be recycled in the same waste stream as traditional polyethylene.

[0030] The EVA copolymer can have a bio-based carbon content of about 1% to about 100%. The use of bio-based ethylene in the EVA copolymer can produce an EVA copolymer with a very high bio-based carbon content. For example, the EVA copolymer can have a bio-based carbon content of at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or nearly 100%. The bio-based carbon content of the EVA copolymer can be tested by methods known to those skilled in the art. For example, the EVA copolymer can be tested. 14 C Analytical Testing. Biobased carbon content can be measured according to the procedure set out by ASTM D6866.

[0031] TPU copolymer is a block copolymer comprising hard and soft blocks or domains formed by the reaction of diisocyanates, chain extenders or short chain diols with polyols or long chain diols. Any type of TPU copolymer known to those skilled in the art is suitable for use herein. Various types of TPU copolymers are produced by varying the ratio, structure and / or molecular weight of the above-mentioned reaction components to fine-tune the structure of the TPU copolymer to the desired final properties of the material. For example, a larger ratio of hard to soft blocks will result in a more rigid TPU, while a larger ratio of soft to hard blocks will result in a more flexible TPU.

[0032] Suitable TPU copolymers can be polyester-based (e.g., derived primarily from adipates) or polyether-based (e.g., primarily based on tetrahydrofuran (THF) ether). Exemplary TPU copolymers are Epamould (Epaflex Polyurethanes Srl, Italy), Epaline (Epaflex Polyurethanes Srl), Epacol (Epaflex Polyurethanes Srl), Pakoflex (Epaflex Polyurethanes Srl), (BASF, Michigan), (Lubrizol,Ohio), ECO (Lubrizol), (Lubrizol), (Lubrizol), (Covestro, Germany), New (New power industrial limited,Hong Kong,China)、 (Huntsman, Texas), (Huntsman), Exelast EC (Shin-Etsu Polymer Europe BV, Netherlands), (COIMSpA,Italy), (Greco, Taiwan, China), ZythaneTM (Alliance Polymers & Services, Michigan) and TPU 95A (Ultimaker, Netherlands).

[0033] Suitable TPU copolymers also include those that are bio-based. In one embodiment, the thermoplastic polyurethane is at least partially bio-based. For example, the TPU copolymer can have a bio-based carbon content of at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, or at least 80%.

[0034] Blending a bio-based EVA copolymer with a TPU copolymer that is at least partially bio-based can increase the bio-based carbon content of the elastomeric composition relative to an elastomeric composition comprising only a pure TPU component. Accordingly, the elastomeric composition can have an overall bio-based carbon content of at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 80%, or at least 90%.

[0035] Blending the EVA component with the TPU component can also reduce the weight of the elastomeric composition, thereby producing a lightweight final product. This is because the density of the TPU copolymer is generally about 1.05 g / cm 3 To about 1.20g / cm 3 The density of EVA copolymer is usually about 0.92g / cm 3 To about 0.95g / cm 3 , which is significantly lower than the density of TPU copolymers.

[0036] The TPU component and the EVA component in the elastomeric composition may be compatible with each other, possibly due to the interaction or reactivity between the vinyl acetate content of the EVA component and the urethane groups in the TPU component.

[0037] The elastomeric composition may also include one or more compatibilizers to facilitate blending of the two polymer components together. Suitable compatibilizers include: organic peroxides; compatibilizing ethylene copolymers; compatibilizers including epoxy resins and styrene-based polymers; polycarbonate polyols; polybutadiene polyols; polysiloxane polyols; and combinations thereof.

[0038] Suitable organic peroxides include, but are not limited to, 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate, α-cumyl peroxyneodecanoate, tert-amyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, 2-hydroxy-1,1-dimethylbutyl peroxyneoheptanoate, α-cumyl peroxyneoheptanoate, tert-butyl peroxyneoheptanoate, di(2-ethylhexyl) peroxydicarbonate, di(n-propyl) peroxydicarbonate, di(sec-butyl) peroxydicarbonate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, diisononanoyl peroxide, didodecanoyl peroxide, 3-hydroxy-1,1-dimethylbutyl peroxyneoheptanoate, α-cumyl peroxyneoheptanoate, tert-butyl peroxyneoheptanoate, di(2-ethylhexyl) peroxydicarbonate, di(n-propyl) peroxydicarbonate, di(sec-butyl) peroxydicarbonate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, diisononanoyl peroxide, didodecanoyl peroxide, ,1-dimethylbutyl peroxy-2-ethylhexanoate, didecanoyl peroxide, 2,2'-azobis(isobutyronitrile), di(3-carboxypropionyl)peroxide, 2,5-dimethyl-2,5-di(2-ethylhexylperoxy)hexane, dibenzoyl peroxide, tert-amyl peroxy-2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxy(cis-3-carboxyl)acrylate, 1,1-di(tert-amylperoxy)cyclohexane, 1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1-di(tert-butylperoxy)cyclohexane alkane, o-tert-amyl-o-(2-ethylhexyl) monoperoxycarbonate, o-tert-butyl-o-isopropyl-monoperoxycarbonate, o-tert-butyl-o-(2-ethylhexyl) monoperoxycarbonate, polyester tetra(tert-butyl peroxycarbonate), 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-amyl peroxyacetate, tert-amyl peroxybenzoate, tert-butyl peroxyisononanoate, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, di-tert-butyl diperoxyphthalate, 2,2-di(tert-butylperoxy)butane, 2,2-di(tert-amylperoxy)propane, 4,4-di n-Butyl (tert-butylperoxy)valerate, ethyl 3,3-di(tert-butylperoxy)butyrate, ethyl 3,3-di(tert-butylperoxyethyl)butyrate, dicumyl peroxide, α,α'-bis(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, di(tert-amyl)peroxide, tert-butyl α-cumyl peroxide, di(tert-butyl)peroxide, 2,5-dimethyl-2,5-(di-tert-butylperoxy)-3-hexane, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-trioxazinone, and mixtures thereof.

[0039] Suitable compatibilizing ethylene copolymers are those having the formula EX, EY or EXY, wherein E is ethylene, X is an α,β-ethylenically unsaturated monomer derived from an alkyl acrylate, an alkyl methacrylate, an alkyl vinyl ether, carbon monoxide, sulfur dioxide, or a mixture thereof (wherein each alkyl group independently contains 1 to 8 carbon atoms), and Y is an α,β-ethylenically unsaturated monomer containing a reactive group that can form a covalent bond with a TPU copolymer component and / or an EVA copolymer component. In one embodiment, X is methyl acrylate, ethyl acrylate, ethyl methacrylate, or butyl acrylate. In one embodiment, Y is glycidyl methacrylate, glycidyl ethacrylate, or glycidyl butylacrylate. An exemplary compatibilizer is an ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer.

[0040] Suitable compatibilizers comprising epoxy resins and styrene-based polymers can be prepared by blending epoxy resins with styrene-based polymers. The specific epoxy resin used can be prepared by reacting an epoxy-containing compound (e.g., epichlorohydrin) with a polyol (e.g., glycerol or bisphenol) in the presence of an alkaline substance sufficient to bind hydrochloric acid to form an epoxy-terminated prepolymer. Epoxy can also be prepared by epoxidizing polyolefins with a peroxide (e.g., peracetic acid). Various epoxy resins can be commercially available with a wide range of epoxy content, molecular weight, softening point, and composition, which can also be used herein. Suitable styrene-based polymers include, but are not limited to, homopolymers of styrene, α-methylstyrene, and p-methylstyrene; high impact polystyrene modified with a rubbery polymer (e.g., styrene-butadiene copolymer rubber, ethylene-propylene copolymer rubber); ethylene-propylene-diene terpolymer rubber; styrene-maleic anhydride copolymer; styrene-acrylonitrile copolymer; styrene-acrylonitrile-butadiene terpolymer; styrene-methyl methacrylate copolymer, etc. An exemplary compatibilizer is styrene acrylonitrile (SA)-epoxy.

[0041] Suitable polycarbonate polyols include, but are not limited to, polycarbonate polyols such as polycarbonate diols (e.g., poly(propylene carbonate (PPC))-diols) or polycarbonate triols; polycaprolactone polyols; alkoxylated polyols; and mixtures thereof. The polyol may be a diol, a triol, a tetraol, or any other polyol, or a combination thereof. An exemplary compatibilizer is poly(propylene carbonate (PPC))-diol.

[0042] Suitable polybutadiene polyols include, but are not limited to, those hydroxyl-functionalized polybutadienes having an average hydroxyl functionality of from about 2 to about 3.

[0043] Suitable polysiloxane polyols include, but are not limited to, those polymers having a polysiloxane backbone with terminal or pendant hydroxyl groups, for example, the polybutadiene polyols described in US Pat. No. 5,916,992, which is incorporated herein by reference in its entirety.

[0044] The amount of the thermoplastic polyurethane copolymer in the elastomeric composition can be from about 10 wt % to about 85 wt %, for example, from about 10 wt % to about 70 wt %, from about 10 wt % to about 55 wt %, from about 10 wt % to about 45 wt %, from about 10 wt % to about 40 wt %, or from about 15 wt % to about 35 wt % of the total elastomeric composition.

[0045] The amount of ethylene-vinyl acetate copolymer in the elastomeric composition can be from about 15% to about 90% by weight of the total elastomeric composition, for example, from about 30% to about 90% by weight, from about 45% to about 90% by weight, from about 55% to about 90% by weight, from about 60% to about 90% by weight, or from about 65% to about 85% by weight.

[0046] The compatibilizer is optionally present in the elastomeric composition and is present in an amount of about 0 wt % to about 10 wt %, such as about 0.1 wt % to about 10 wt %, about 0.2 wt % to about 8 wt %, or about 0.5 wt % to about 5 wt % of the total elastomeric composition.

[0047] In one embodiment, the elastomeric composition comprises: about 10 wt % to 85 wt % of ethylene vinyl acetate copolymer, about 15 wt % to 90 wt % of thermoplastic polyurethane, and about 0 wt % to 10 wt % of a compatibilizer.

[0048] In one embodiment, the elastomeric composition comprises: about 10 wt % to 40 wt % of ethylene vinyl acetate copolymer, about 60 wt % to 90 wt % of thermoplastic polyurethane, and about 0 wt % to 5 wt % of a compatibilizer.

[0049] In one embodiment, the elastomeric composition comprises: about 15 wt % to 35 wt % of ethylene vinyl acetate copolymer, about 65 wt % to 85 wt % of thermoplastic polyurethane, and about 0 wt % to 5 wt % of a compatibilizer.

[0050] In one embodiment, the elastomeric composition comprises: about 15 wt % to 35 wt % of ethylene vinyl acetate copolymer, about 65 wt % to 85 wt % of thermoplastic polyurethane, and about 0.5 wt % to 5 wt % of a compatibilizer.

[0051] The elastomer composition can also include a rubber component. The rubber component can include natural rubber (NR), synthetic rubber or its mixture. Representative synthetic rubber-like polymers include synthetic rubbers based on dienes, such as homopolymers of conjugated diene monomers, and copolymers and terpolymers of the conjugated diene monomers and monovinyl aromatic monomers and trienes. Exemplary diene-based compounds include, but are not limited to, polyisoprene (IR), such as 1,4-cis-polyisoprene and 3,4-polyisoprene; chloroprene rubber; polystyrene; styrene-butadiene rubber (SBR); polybutadiene (BR); 1,2-vinyl-polybutadiene; butadiene-isoprene copolymer; butadiene-isoprene-styrene terpolymer; isoprene-styrene copolymer; styrene / isoprene / butadiene copolymer; styrene / isoprene copolymer; styrene-butadiene emulsion copolymer; styrene / butadiene solution copolymer; butyl rubber, such as isobutylene rubber; ethylene / propylene copolymer, such as ethylene propylene diene monomer (EPDM) or ethylene propylene rubber (EPM); and mixtures thereof. A rubber component having a branched structure formed by using a multifunctional modifier such as tin tetrachloride or a multifunctional monomer such as divinylbenzene may also be used. Other suitable rubber components include nitrile rubber, acrylonitrile-butadiene rubber (NBR), silicone rubber (e.g., methyl vinyl silicone rubber, dimethyl silicone rubber, etc.), fluoroelastomers, acrylic rubber (alkyl acrylate copolymers (ACM), such as ethylene acrylic rubber), epichlorohydrin rubber, chlorinated polyethylene rubber (e.g., chloroprene rubber), chlorosulfonated polyethylene rubber, hydrogenated nitrile rubber, hydrogenated isoprene-isobutylene rubber, tetrafluoroethylene-propylene rubber, and blends thereof.

[0052] The amount of the rubber component in the elastomeric composition may be from about 0 wt % to about 50 wt %, for example from about 0.5 wt % to about 40 wt %, from about 1 wt % to about 30 wt %, or from about 5 wt % to about 20 wt % of the total elastomeric composition.

[0053] The elastomeric composition may also be used as a rubber substitute for applications where rubber is used.

[0054] The elastomer compositions discussed above according to the present invention show excellent performance. For example, compared with the same elastomer compositions without EVA components, the elastomer compositions comprising TPU components and EVA components simultaneously crystallize faster and obtain higher melting points. Compared with the same elastomer compositions without EVA components, the elastomer compositions comprising TPU components and EVA components simultaneously also have reduced melt rheology (measured by melt viscosity |η*| value). Finally, compared with the same elastomer compositions without EVA components, the elastomer compositions comprising TPU components and EVA components simultaneously also have improved tensile properties, including tensile modulus increased at certain EVA concentrations, increased strain hardening, and increased tensile stress at break.

[0055] The elastomeric composition prepared by blending the TPU component and the EVA component alone or with a compatibilizer and / or a rubber component can obtain a melting point (melting peak temperature) of at least about 198°C, at least about 200°C, at least about 201°C, at least about 202°C, at least about 203°C, or at least about 204°C.

[0056] The elastomeric composition prepared by blending the TPU component and the EVA component alone or with a compatibilizer and / or a rubber component can obtain a tensile modulus of at least about 20 MPa, at least about 35 MPa, at least about 45 MPa, at least about 50 MPa, at least about 60 MPa, at least about 66 MPa, at least about 70 MPa, or at least about 80 MPa as measured by standard ASTM D638.

[0057] The elastomeric composition prepared by blending the TPU component and the EVA component alone, or together with a compatibilizer and / or a rubber component, has a tensile modulus increased by at least about 200%, at least about 2.5 times, at least about 3.3 times, at least about 4 times, or at least about 5 times compared to the same elastomeric composition without the ethylene-vinyl acetate copolymer.

[0058] The elastomeric composition prepared by blending the TPU component and the EVA component alone or together with a compatibilizer and / or a rubber component can obtain a tensile stress at break of at least about 35 MPa, at least about 40 MPa, at least about 45 MPa, or at least about 50 MPa measured by standard ASTM D638.

[0059] The elastomeric composition prepared by blending the TPU component and the EVA component alone, or together with a compatibilizer and / or a rubber component, can have a comparable tensile stress at break, or an increase in tensile stress at break of at least about 1% to 25% compared to the same elastomeric composition without the ethylene vinyl acetate copolymer.

[0060] Thus, one aspect of the present invention also relates to a variety of molded products formed from the above-described elastomeric composition.Such molded products can be constructed, shaped, molded and cured by various methods known to those skilled in the art.

[0061] All above descriptions and all embodiments in the context of the elastomeric composition apply to this aspect of the invention relating to the moulded product.

[0062] Suitable molded articles include, but are not limited to, footwear products, automotive products, furniture products, textiles, sports / leisure products, or consumer electronics products. Exemplary molded articles include soles or shoe parts, films, tubes, fibers, cables, ear tags, motor vehicle parts, automotive parts, hoses, belts, damping elements; handrails, furniture elements, ski boots, stop buffers, rollers, ski goggles, putty, antennas and tripods, handles, housings, switches, and coatings and coating elements.

[0063] Example

[0064] The following examples are provided for illustrative purposes only and are not intended to limit the scope of the present invention in any way.

[0065] Example 1: Preparation of an elastomeric composition containing TPU and EVA

[0066] The thermoplastic polyurethane (TPU) component used is commercially available ECO 12T95 (Lubixo, Ohio), a thermoplastic polyurethane with about 32% biobased content. This partially biobased TPU has properties similar to conventional TPU without biobased content.

[0067] The ethylene-vinyl acetate copolymer (EVA) components used in the following examples include commercially available 8019PE (Brazil, Braskem), which contains about 19% vinyl acetate and has a melt flow rate of about 8 g / 10 min (190°C / 2.16 kg) measured by ASTM-D1238. The ethylene-vinyl acetate copolymer (EVA) used also includes commercially available HM728 (Brazil, Braskem), which contains about 28% vinyl acetate and has a melt flow rate of about 6 g / 10 min (190°C / 2.16 kg) measured by ASTM-D1238. If not otherwise specified, the former EVA with a vinyl acetate content of 19% is used in the elastomer composition. The latter EVA with a vinyl acetate content of 28% is used in the elastomer sample called "high VA".

[0068] The exemplary elastomer compositions were prepared by blending the above TPU and EVA components at TPU / EVA weight ratios of 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, and 85 / 15, respectively. In the various examples below, some of the elastomer compositions further comprised a compatibilizer, such as an organic peroxide, an ethylene methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer (e.g. AX8900), or styrene acrylonitrile (SA)-epoxy (e.g., ADR-4300).

[0069] The elastomeric composition was prepared by mixing and extruding the components using an 18 mm twin screw extruder (Coperion GmbH, Germany) on an eight zone extruder using the following temperature profile: 220 / 220 / 210 / 200 / 190 / 190 / 180 / 170 (° C.). All samples were produced at a rate of 10 lbs / hour and a screw speed of 300 rpm. All samples were dried before mixing.

[0070] Example 2: Characterization of Elastomeric Compositions Comprising TPU and EVA

[0071] In this example, the melting and crystallization, melt rheology, and tensile properties of the elastomeric composition prepared according to Example 1 were characterized.

[0072] All physical and mechanical tests were performed according to ASTM standards.

[0073] Melting and crystallization

[0074] Melting and crystallization spectra were collected using a TA1000 differential scanning calorimeter (DSC). The sample was cooled from the melt (starting at 220°C) at a rate of 10°C / min to capture the crystallization exotherm. Subsequent heating scans were performed at a rate of 20°C / min to capture the details of the melting endotherm.

[0075] The melting peak temperature and crystallization peak temperature of the elastomeric composition comprising a blend of TPU and EVA components (using EVA containing about 19% vinyl acetate content) having a TPU / EVA weight ratio of 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, 85 / 15 and 100 / 0 (i.e., pure TPU) are as follows: Figure 1 shown. Figure 1 It is shown that the TPU component crystallizes faster in the presence of the EVA component, which results in a higher melting point when the elastomeric composition contains increasing amounts of the EVA component.

[0076] According to the results obtained from DSC testing, for EVA concentrations ranging from 0% to 70%, the heat of fusion [TPU hardness] remains constant (about 4 J / g).

[0077] Melt Rheology

[0078] Melt rheology data were collected using an ARES torsional rheometer. All samples were subjected to a standard frequency sweep at 220°C. Melt flow data were measured using the ASTM D1238 standard.

[0079] The melt viscosity |η*| values ​​of the elastomeric compositions comprising blends of TPU components and EVA components (using EVA containing about 19% vinyl acetate content) having TPU / EVA weight ratios of 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, 85 / 15 and 85 / 15 (i.e., pure TPU) are as follows: Figure 2 shown.

[0080] The tan δ values ​​of the elastomer compositions comprising blends of a TPU component and an EVA component (using EVA containing about 19% vinyl acetate content) having a TPU / EVA weight ratio of 30 / 70, 45 / 55, 55 / 45 and 70 / 30 are as follows: Figure 3 shown.

[0081] The tan δ values ​​of the elastomeric compositions comprising a blend of a TPU component and an EVA component (using EVA containing about 19% vinyl acetate content) in a TPU / EVA weight ratio of 70 / 30 and a compatibilizer (organic peroxide, E-MA-GMA terpolymer or SA-epoxy, respectively) are compared with the tan δ values ​​of the same compositions without the compatibilizer. Figure 4 The amount of organic peroxide used was 0.05 wt% loading. The amount of SA-epoxy used was 2 wt% loading. The amount of E-MA-GMA used was 5 wt% loading.

[0082] Tensile properties

[0083] All tensile tests were measured using standard ASTM D638. Izod impact was measured according to standard ASTM D256.

[0084] Figure 5 The tensile elongation results of elastomeric compositions comprising blends of a TPU component and an EVA component (using EVA containing about 19% vinyl acetate content) having TPU / EVA weight ratios of 0 / 100 (i.e., pure EVA), 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, 85 / 15, and 100 / 0 (i.e., pure TPU), respectively.

[0085] Figure 6 The tensile stress at break results for elastomeric compositions comprising blends of TPU components and EVA components (using EVA containing about 19% vinyl acetate content) having TPU / EVA weight ratios of 0 / 100, 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, 85 / 15 and 100 / 0 are shown. Figure 6 As shown, when EVA (15 wt%) is blended in the elastomer composition, the tensile stress at break of the elastomer composition increases by about 10 MPa (about 25%) compared to pure TPU polymer, but when the amount of EVA in the elastomer composition is further increased, the tensile stress at break decreases again.

[0086] Figure 7 The tensile modulus results for elastomeric compositions comprising blends of TPU components and EVA components (using EVA containing about 19% vinyl acetate content) having TPU / EVA weight ratios of 0 / 100, 15 / 85, 30 / 70, 45 / 55, 55 / 45, 70 / 30, 85 / 15 and 100 / 0 are shown. Figure 7 As shown in the figure, when EVA (15 wt%) is blended in the elastomer composition, the tensile modulus of the elastomer composition increases by about 65 MPa (more than 4 times) and peaks at about 80 MPa compared to the pure TPU polymer, but when the amount of EVA in the elastomer composition is further increased, the tensile modulus decreases again. However, all elastomer compositions with EVA components show significantly higher tensile modulus performance than pure TPU polymer.

[0087] Figure 8 The tensile strain-hardening results of elastomeric compositions comprising blends of TPU components and EVA components (using EVA containing about 19% vinyl acetate content) having TPU / EVA weight ratios of 0 / 100, 70 / 30, 85 / 15 and 100 / 0 are shown. Figure 8 As shown, the strain hardening in the elastomeric composition comprising a blend of a TPU component and an EVA component is greater than the strain hardening of the pure TPU polymer.

[0088] Fig. 9The tensile elongation results of elastomeric compositions comprising a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30 and a compatibilizer (organic peroxide - blend + OP; E-MA-GMA terpolymer - blend + E-MA-GMA; or SA-epoxy - blend + SA-epoxy, respectively) are shown, compared with the tensile elongation results of a control (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 19%, without a compatibilizer) and a high VA (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 28%, without a compatibilizer). The amount of organic peroxide used is 0.05 wt% loading. The amount of SA-epoxy used is 2 wt% loading. The amount of E-MA-GMA used was 5 wt% loading.

[0089] Fig.10 The tensile stress at break results for elastomeric compositions comprising a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30 and a compatibilizer (an organic peroxide; an E-MA-GMA terpolymer; or a SA-epoxy, respectively) are shown, compared to the tensile elongation results for a control (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 19%, without a compatibilizer) and a high VA (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 28%, without a compatibilizer). The organic peroxide was used at 0.05 wt% loading. The SA-epoxy was used at 2 wt% loading. The E-MA-GMA was used at 5 wt% loading.

[0090] Fig.11 The tensile modulus results for elastomeric compositions comprising a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30 and a compatibilizer (organic peroxide; E-MA-GMA terpolymer-blend; or SA-epoxy, respectively) are shown, compared to the tensile elongation results for a control (a blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 19%, without a compatibilizer) and a high VA blend of a TPU component and an EVA component having a TPU / EVA weight ratio of about 70 / 30, using an EVA having a vinyl acetate content of about 28%, without a compatibilizer). The amount of organic peroxide used was 0.05 wt% loading. The amount of SA-epoxy used was 2 wt% loading. The amount of E-MA-GMA used was 5 wt% loading.

Claims

1. An elastomeric composition comprising: 10 to 85 wt% ethylene-vinyl acetate copolymer; 15 to 90 weight percent thermoplastic polyurethane; and 0 to 10 wt % of a compatibilizer; in, The elastomeric composition has a tensile modulus of at least 20 MPa, measured according to Standard ASTM D638.

2. The elastomer composition according to claim 1, wherein The elastomeric composition has a melting point of at least 200°C.

3. The elastomer composition according to claim 1, in, The tensile modulus of said elastomeric composition, measured according to standard ASTM D638, is increased by at least 200% compared to the same elastomeric composition without said ethylene-vinyl acetate copolymer.

4. The elastomer composition according to any one of claims 1 to 3, wherein The ethylene vinyl acetate copolymer has a bio-based carbon content of 1% to 100%.

5. The elastomer composition according to claim 4, wherein The ethylene vinyl acetate copolymer has a bio-based carbon content of at least 50%.

6. The elastomer composition according to any one of claims 1 to 3, wherein The vinyl acetate content in the ethylene-vinyl acetate copolymer is in the range of 2 wt % to 40 wt %.

7. The elastomer composition according to any one of claims 1 to 3, wherein The thermoplastic polyurethanes are polyester-based or polyether-based.

8. The elastomer composition according to any one of claims 1 to 3, wherein The thermoplastic polyurethane is at least partially bio-based.

9. The elastomer composition according to claim 8, wherein The thermoplastic polyurethane has a bio-based carbon content of at least 30%.

10. The elastomer composition according to any one of claims 1 to 3, wherein The elastomeric composition has a bio-based carbon content greater than 30%.

11. The elastomer composition according to any one of claims 1 to 3, wherein The elastomeric composition has a bio-based carbon content of at least 40%.

12. The elastomer composition according to any one of claims 1 to 3, wherein The compatibilizer is present and includes an organic peroxide, ethylene methyl acrylate-glycidyl methacrylate (EMA-GMA) terpolymer, or styrene acrylonitrile (SA)-epoxy, poly(propylene carbonate (PPC))-diol, or a combination thereof.

13. The elastomeric composition according to any one of claims 1 to 3, comprising: 10 to 40% by weight of ethylene-vinyl acetate copolymer, 60 to 90 wt. % of thermoplastic polyurethane, and 0 wt % to 5 wt % of a compatibilizer.

14. The elastomeric composition according to claim 13, comprising: 15 to 35% by weight of ethylene-vinyl acetate copolymer, 65 to 85 wt. % thermoplastic polyurethane.

15. The elastomeric composition according to claim 13, comprising: 0.5 wt % to 5 wt % of a compatibilizer.

16. The elastomer composition according to any one of claims 1 to 3, wherein The ethylene-vinyl acetate copolymer is based on ethylene produced from a bio-based carbon source.

17. The elastomer composition according to claim 14, wherein The elastomeric composition has a tensile stress at break of at least 40 MPa, measured according to standard ASTM D638.

18. The elastomer composition according to claim 14, wherein The tensile stress at break of said elastomeric composition, measured according to standard ASTM D638, is increased by at least 10% compared to the same elastomeric composition without said ethylene-vinyl acetate copolymer.

19. The elastomeric composition according to any one of claims 1 to 3, further comprising: The rubber component includes natural rubber, synthetic rubber, or a mixture thereof.

20. A molded article formed from the elastomeric composition of any one of Claims 1-3.

21. The molded article according to claim 20, wherein The molded article is a footwear product, an automotive product, a furniture product, a textile product, a sports / leisure product, or a consumer electronic product.

22. The molded article according to claim 21, wherein The molded articles are soles or shoe parts, films, tubes, fibers, cables, ear tags, motor vehicle parts, automotive parts, hoses, belts, damping elements; handrails, furniture elements, ski boots, stop buffers, rollers, ski goggles, putties, antennas and tripods, handles, housings, switches, or coatings and coating elements.

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