Midsole

Abstract

A midsole for a shoe consisting of a foamed peroxide-crosslinked polyolefin elastomer includes a silane-grafted polyolefin component, an elastomer component, and an additive dispersed in the foamed peroxide-crosslinked polyolefin elastomer. The elastomer component includes one or more elastomeric polymers selected from the group consisting of ethylene-vinyl acetate copolymer, polyolefin elastomer, olefin block copolymer, polyoctene, anhydride-modified ethylene copolymer, ethylene-propylene-diene terpolymer, and combinations thereof. The silane-grafted polyolefin component and the elastomer component are crosslinked by C-C bonds. Advantageously, the foamed peroxide-crosslinked polyolefin elastomer is substantially free of silane crosslinking and substantially free of water at the time of formation. Characteristically, the amount of additive and the one or more elastomeric polymers is sufficient to cause the melting temperature of crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, to be greater than 100 °C.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 084,256, filed on September 28, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] In at least one aspect, the present invention relates to polymer compositions that can be used to form shoe midsoles. Background Technology

[0004] Materials used to form shoe midsoles need to meet various material performance requirements. Specifically, properties such as density, rebound, abrasion resistance, stiffness as a measure of hardness, processability, and / or shock absorption are important parameters. From athletic shoes to shoes for seniors, soles must provide superior comfort, grip, and durability. Improving the performance requirements of shoe midsole materials often involves developing new polymer compositions and methods for manufacturing multifunctional soles. Furthermore, ideally, shoe midsoles should be easier to produce, lighter in weight, and possess excellent durability over a longer period.

[0005] The most common material used to manufacture midsoles is ethylene vinyl acetate (EVA) in the form of expanded foam rubber. Like most rubbers, EVA is soft and elastic, but due to its thermoplasticity (before cross-linking), it is also easy to process and handle when making multi-functional items, including midsoles. While EVA is often chosen as an ideal material for midsole production due to its "low-temperature" toughness, resistance to stress cracking, water resistance, and UV radiation resistance, the biggest criticism of EVA is its short lifespan. Over time, EVA tends to compress, and users (especially runners) say they feel their shoes flatten after a while. Currently, the only way to prevent EVA midsoles from flattening is to replace the shoes every 3 to 6 months.

[0006] Therefore, there is a need for improved compositions used to form shoe midsoles. Summary of the Invention

[0007] In at least one aspect, a shoe midsole is provided comprising a foamed peroxide-crosslinked polyolefin elastomer. The foamed peroxide-crosslinked polyolefin elastomer comprises a silane-grafted polyolefin component, an elastomer component, and additives dispersed within the foamed peroxide-crosslinked polyolefin elastomer. The elastomer component comprises one or more elastomer polymers selected from the group consisting of ethylene-vinyl acetate copolymers, polyolefin elastomers, olefin block copolymers, polyoctene, anhydride-modified ethylene copolymers, ethylene-propylene-diene terpolymers, and combinations thereof. The silane-grafted polyolefin component and the elastomer component are crosslinked via C-C bonds. Advantageously, the foamed peroxide-crosslinked polyolefin elastomer is substantially free of silane crosslinking and substantially free of water during its formation. Characteristically, the amount of additives and one or more elastomer polymers is sufficient to cause the melting temperature of the crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, to be above 100°C.

[0008] On the other hand, a method for preparing a shoe midsole composed of a foamed peroxide-crosslinked polyolefin elastomer includes the step of forming component A, which comprises a mixture of a first silane-grafted polyolefin component and a second silane-grafted polyolefin component. The method further includes the step of forming component B, which comprises a foaming agent, a peroxide, an optional activator, an optional accelerator, other additives, and an elastomer component. The elastomer component comprises one or more elastomer polymers selected from the group consisting of ethylene-vinyl acetate copolymers, polyolefin elastomers, olefin block copolymers, polyoctene, anhydride-modified ethylene copolymers, ethylene-propylene-diene terpolymers, and combinations thereof. Component A and component B are mixed together to form a reaction mixture. The reaction mixture is reacted under anhydrous conditions at a reaction temperature for a predetermined time period to form a foamed peroxide-crosslinked polyolefin elastomer, such that the first silane-grafted polyolefin is crosslinked with the second silane-grafted polyolefin and the elastomer component via C-C bonds, and the second silane-grafted polyolefin is crosslinked with the elastomer component via C-C bonds, and such that the foamed peroxide-crosslinked polyolefin elastomer comprises a plurality of closed cells. Advantageously, the foamed peroxide-crosslinked polyolefin elastomer is substantially free of silane crosslinking and substantially free of water during formation. Characteristically, the amount of optional additives (if present) and elastomeric polymer is sufficient to make the melt temperature of the crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, greater than 100°C.

[0009] On the other hand, a masterbatch is provided for forming a midsole composed of a foamed peroxide-crosslinked polyolefin elastomer. The masterbatch includes a foaming agent, a peroxide, an optional activator, an optional accelerator, other additives, and an elastomer component. The elastomer component includes one or more elastomer polymers selected from the group consisting of ethylene-vinyl acetate copolymers, polyolefin elastomers, olefin block copolymers, polyoctene, anhydride-modified ethylene copolymers, ethylene-propylene-diene terpolymers, and combinations thereof. The masterbatch is suitable for combination (e.g., mixing) with component A under anhydrous conditions to form a reaction mixture. Component A includes a mixture of a first silane-grafted polyolefin, a second silane-grafted polyolefin, and optionally one or more other silane-grafted polyolefins. The reaction mixture is reacted under anhydrous conditions at a reaction temperature for a predetermined time to form a foamed peroxide-crosslinked polyolefin elastomer, such that a first silane-grafted polyolefin is crosslinked with a second silane-grafted polyolefin and an elastomer component via C-C bonds, and the second silane-grafted polyolefin is also crosslinked with the elastomer component via C-C bonds, such that the foamed peroxide-crosslinked polyolefin elastomer comprises a plurality of closed-cell structures. The foamed peroxide-crosslinked polyolefin elastomer is substantially free of silane crosslinking and substantially free of water at the time of formation. Characteristically, the amounts of optional additives (if present) and polymers are sufficient to make the melting temperature of the crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, greater than 100°C.

[0010] The foregoing is illustrative only and is not intended to be limiting in any way. Further aspects, embodiments, and features will become apparent from the accompanying drawings and the following detailed description, in addition to the illustrative aspects, embodiments, and features described above. Attached Figure Description

[0011] To further understand the nature, purpose, and advantages of the present invention, reference should be made to the following detailed description, which should be read in conjunction with the accompanying drawings, wherein like reference numerals denote like elements, and wherein:

[0012] Figure 1 A perspective view of a shoe according to some aspects of the present invention.

[0013] Figure 2 . Figure 1 The image depicts a cross-sectional perspective view of the shoe.

[0014] Figure 3A A perspective view of the shoe midsole.

[0015] Figure 3B A cross-sectional view of the shoe midsole.

[0016] Figure 3C A flowchart depicting the process of manufacturing a shoe midsole.

[0017] Figure 4 A comparison graph of POE with and without silane grafting, obtained using a rotating cylinder shear rheometer.

[0018] Figure 5A , 5B Stress and strain of Examples 1-4 and EVA control, 5C, 5D, 5E.

[0019] Figure 6 DSC plots of heat flow versus temperature for Examples 1-4 and EVA.

[0020] Figure 7 The heating portion of the DSC graphs of heat flow versus temperature for Examples 1-4 and EVA comparison.

[0021] Figure 8A Graphs showing the relationship between Tanδ and temperature for Examples 1-4 and EVA control.

[0022] Figure 8B Graph showing the relationship between energy storage modulus and temperature for Examples 1-4 and EVA control.

[0023] Figure 9 Curing curves of Examples 1-4 and EVA control.

[0024] Figure 10 Shear stress versus shear rate curves obtained from a rubber process analyzer (RPA) for determining long-chain branching.

[0025] Figure 11A and 11B Example 1: SEM cross-sections at 25×(A) and 50×(B).

[0026] Figure 12A and 12B Example 2: SEM cross-sections at 25×(A) and 50×(B).

[0027] Figure 13A and 13B Example 3: SEM cross-sections at 25×(A) and 50×(B).

[0028] Figure 14A and 14B Example 4: SEM cross-sections at 25×(A) and 50×(B).

[0029] Figure 15A and 15B .EVA control cross sections at 25×(A) and 50×(B). Detailed Implementation

[0030] Reference will now be made in detail to the currently preferred compositions, embodiments, and methods of the invention, which constitute the best mode known to the inventors for carrying out the invention. The drawings are not necessarily drawn to scale. However, it should be understood that the disclosed embodiments are merely exemplary of the invention and may be embodied in various alternative forms. Therefore, the specific details disclosed herein should not be construed as limiting, but only as a representative basis for any aspect of the invention and / or as a representative basis for teaching those skilled in the art to carry out the invention in different ways.

[0031] Unless explicitly stated in the examples or otherwise, all numerical values ​​indicating amounts of material or reaction and / or conditions of use in this specification should be understood to be modified by the word "about" when describing the broadest scope of the invention. It is generally preferred to practice within the specified numerical ranges. Furthermore, unless explicitly stated to the contrary: all R groups (e.g., R...) i (where i is an integer) includes hydrogen, alkyl, lower alkyl, C 1-6 Alkyl, C 6-10 Aryl, C 6-10 heteroaryl, -NO2, -NH2, -N(R'R”), -N(R'R”R”') + L - , Cl, F, Br, -CF3, -CCl3, -CN, -SO3H, -PO3H2, -COOH, -CO2R', -COR', -CHO, -OH, -OR', -O - M + -SO3 - M + -PO3 - M + -COO - M + -CF2H, -CF2R', -CFH2 and -CFR'R", where R', R" and R"' are C 1-10 Alkyl or C 6-18 It is aryl, M + For metal ions, L - It is a negatively charged counterion; the single letter (e.g., "n" or "o") is 1, 2, 3, 4, or 5; in the compounds disclosed herein, the CH bond can be alkyl, lower alkyl, C 1-6 Alkyl, C 6-10 Aryl, C 6-10 heteroaryl, -NO2, -NH2, -N(R'R”), -N(R'R”R”') + L - , Cl, F, Br, -CF3, -CCl3, -CN, -SO3H, -PO3H2, -COOH, -CO2R', -COR', -CHO, -OH, -OR', -O- M + -SO3 - M + -PO3 - M + -COO - M + -CF2H, -CF2R', -CFH2 and -CFR'R" are replaced, where R', R" and R"' are C 1-10 Alkyl or C 6-18 It is aryl, M + For metal ions, L - Negatively charged counterions; percentages, "parts," and ratio values ​​are all by weight; the term "polymer" includes "oligomer," "copolymer," "terpolymer," "block," "random," "segmented block," etc.; unless otherwise stated, the molecular weight provided for any polymer is a weight-average molecular weight; a description of a group or class of materials suitable or preferred for a given purpose in relation to the invention means that any two or more components in that group or class are equally suitable or preferred; a component description in chemical terms refers to the component when added to any combination specified in the description and does not necessarily exclude chemical interactions between components of the mixture after mixing; the first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation herein and is subject to the normal grammatical variation applicable to the initially defined abbreviation; and unless explicitly stated to the contrary, measurements of properties are determined by the same technique referenced previously or subsequently for the same property.

[0032] Unless explicitly stated by example or otherwise, all numerical values ​​indicating amounts of material or reaction and / or conditions of use in this specification should be understood to be modified by the word “about” when describing the broadest scope of the invention. It is generally preferred to practice within the specified numerical range. Furthermore, unless explicitly stated to the contrary: percentages, “parts”, and ratio values ​​are by weight; the term “polymer” includes “oligomer,” “copolymer,” “terpolymer,” “block,” “random,” “segmented block,” etc.; a description of a group or class of materials suitable or preferred for a given purpose in relation to the invention means that any two or more components in that group or class are equally suitable or preferred; a description of components in chemical terms refers to the components added to any combination specified in the description and does not necessarily exclude chemical interactions between components of the mixture after mixing; the first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation herein, and is subject to the normal grammatical variations applicable to the initially defined abbreviation; and, unless explicitly stated to the contrary, measurements of properties are determined by the same technique referenced previously or subsequently for the same property.

[0033] It should also be noted that, as used in the specification and appended claims, the singular forms “a,” “an,” and “the” include plural objects unless the context clearly indicates otherwise. For example, references to singular components are intended to include multiple components.

[0034] As used herein, the term "about" refers to a quantity or value that can be a specific value or some other value adjacent to it. Generally, the term "about" indicating a specific value is intended to indicate a range of + / - 5% of that value. As an example, the phrase "about 100" indicates a range of 100 + / - 5, that is, from 95 to 105. Generally, when using the term "about," it is expected that similar results or effects according to the invention can be obtained within a range of + / - 5% of the indicated value.

[0035] As used herein, the term "and / or" means that all elements of the group may be present or only one element may be present. For example, "A and / or B" means "A only, or B only, or A and B". In the case of "A only", the term also covers the possibility that B is not present, i.e., "A only, but no B".

[0036] It should also be understood that the present invention is not limited to the specific embodiments and methods described below, as specific components and / or conditions can certainly vary. Furthermore, the terminology used herein is for the purpose of describing specific embodiments of the invention only and is not intended to be limiting in any way.

[0037] The term "comprising" is synonymous with "including," "having," "containing," or "characterized by." These terms are inclusive and open-ended, and do not exclude additional, unlisted elements or methodological steps.

[0038] The phrase "consisting of" excludes any element, step, or ingredient not specified in the claims. When this phrase appears in a clause of the body of a claim, rather than immediately following the preamble, it only limits the element specified in that clause; other elements are not excluded from the entire claim.

[0039] The phrase “consistent essentially of…” limits the scope of the claim to the specified materials or steps, as well as those that do not substantially affect the basic and novel features of the claimed subject matter.

[0040] The phrase "composed of" means "including" or "comprises". Typically, this phrase is used to indicate that an object is formed from a single material.

[0041] Regarding the terms “comprising,” “consisting of,” and “substantially composed of,” one of these three terms is used herein, and the currently disclosed and claimed subject matter may include the use of either of the other two terms.

[0042] The terms "one or more" mean "at least one," and "at least one" means "one or more." The terms "one or more" and "at least one" include "multiple" as a subset.

[0043] The terms “substantially,” “generally,” or “about” are used herein to describe disclosed or claimed embodiments. The term “substantially” may be modified to a value or related characteristic disclosed or claimed in this invention. In this case, “substantially” may mean that the modified value or related characteristic is within ±0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, or 10% of that value or related characteristic.

[0044] It should also be understood that an integer range explicitly includes all intermediate integers. For example, the integer range 1-10 explicitly includes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Similarly, the range 1 to 100 includes 1, 2, 3, 4...97, 98, 99, and 100. Likewise, when any range is required, the intermediate number of the increment between the difference between the upper and lower limits divided by 10 can be used as an alternative upper or lower limit. For example, if the range is 1.1-2.1, the following numbers could be chosen as the lower or upper limit: 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0.

[0045] In the examples described herein, properties, concentrations, temperatures, and reaction conditions (e.g., pressure, pH, flow rate, etc.) can be implemented within ±50% of the values ​​provided in the examples, rounded or truncated to two significant figures. In one improvement, concentrations, temperatures, and reaction conditions (e.g., pressure, pH, flow rate, etc.) can be implemented within ±30% of the values ​​provided in the examples, rounded or truncated to two significant figures. In another improvement, concentrations, temperatures, and reaction conditions (e.g., pressure, pH, flow rate, etc.) can be implemented within ±10% of the values ​​provided in the examples, rounded or truncated to two significant figures.

[0046] For all compounds represented by empirical chemical formulas with multiple alphanumeric subscripts (e.g., CH2O), the values ​​of the subscripts can be rounded or truncated to two significant figures plus or minus 50%. For example, if CH2O is indicated, the formula is represented as C. (0.8-1.2) H (1.6-2.4) O (0.8-1.2)The compound. In one improvement, the subscript value may be rounded or truncated to two significant figures plus or minus 30%. In yet another improvement, the subscript value may be rounded or truncated to two significant figures plus or minus 20%.

[0047] For the purposes of this description, the terms “up,” “down,” “right,” “left,” “back,” “front,” “vertical,” “horizontal,” and their derivatives should be used interchangeably with those used in this document. Figure 1 The orientation of the shoe shown relates to the sole. However, it should be understood that the sole, composition, and method may take various alternative orientations and sequences of steps unless expressly specified otherwise. It should also be understood that the specific apparatus and processes shown in the accompanying drawings and described in the following specification are merely exemplary embodiments of the inventive concept as defined in the appended claims. Therefore, specific dimensions and other physical characteristics relating to the embodiments disclosed herein should not be considered limiting unless expressly stated otherwise in the claims.

[0048] The term "copolymer" refers to a polymer obtained by linking more than one type of monomer in the same polymer chain.

[0049] The term "comonomer" refers to an olefin comonomer that is suitable for polymerization with olefin monomers (such as ethylene or propylene monomers).

[0050] The term "homogeneous polymer" refers to a polymer obtained by linking olefin monomers in the absence of comonomers.

[0051] The term "polymer backbone" refers to the covalent chain of repeating monomer units that form a polymer, which optionally has side groups including another polymer backbone attached to it.

[0052] The term "residue" refers to a portion of a molecular entity, typically a major part, such as a molecule or a part of a molecule, such as a group, that has undergone a chemical reaction and is now covalently linked to another molecular entity. In one refinement, the term "residue" refers to an organic structure incorporated into the polymer through a condensation or ring-opening polymerization reaction involving the corresponding monomer. In another refinement, when used to refer to a monomer or monomer unit, the term "residue" refers to the remaining portion of the monomer unit after it has been incorporated into the polymer chain.

[0053] Throughout this application, where publications are referenced, the entire disclosure of those publications is incorporated herein by reference to provide a more complete description of the technical state to which this invention pertains.

[0054] Abbreviations:

[0055] “C / set” indicates compression deformation.

[0056] “DSC” stands for Differential Scanning Calorimetry.

[0057] “Eb” represents the elongation at break.

[0058] “EPDM” stands for ethylene propylene diene monomer.

[0059] “ER” represents the expansion rate.

[0060] "EVA" stands for vinyl acetate.

[0061] "Hd" indicates hardness.

[0062] “Mn” represents the number-average molecular weight.

[0063] “Mw” represents the weight-average molecular weight.

[0064] "POE" stands for polyolefin elastomer.

[0065] “OBC” refers to olefin block copolymer.

[0066] “phr” indicates the number of parts per 100 parts by weight of rubber.

[0067] “Sp.Gr.” indicates specific gravity.

[0068] “Tb” represents the tensile strength at fracture.

[0069] Figure 1 A perspective view of a shoe comprising a midsole made of a foamed peroxide-crosslinked polyolefin elastomer as described herein is provided. Figure 2 Provided Figure 1 The image depicts a cross-sectional view of the shoe. Shoe 10 includes an outsole 14 attached to a midsole 18, with the midsole 18 positioned directly above the outsole 14. A toe box 22, together with a toe cap 26, forms the forefoot of shoe 10. The toe box 22 and toe cap 26 are positioned to support and surround the toes. A tongue 30 integrates with an upper 34 to support the instep. A collar 38 and a heel stabilizer 42 are positioned at the rear of shoe 10 and work together to comfortably position and hold the heel within shoe 10. Although... Figure 1 The description refers to running shoes, but shoe 10 is not intended to be a limitation, and shoe 10 may also include, for example, other athletic shoes, sandals, hiking boots, winter boots, dress shoes, and medical orthopedic shoes. Figure 2 The cross-sectional view shows the corresponding thickness of the outsole 14 compared to the midsole 18. The midsole 18 is the portion of the shoe 10 sandwiched between the outsole 14 and the instep lining 46. The midsole 18 provides cushioning and rebound while helping to protect the feet from hard or sharp objects. The foot contacts the sock lining 50, positioned as the top layer on the instep lining 46, while the foot's positioning inside the shoe 10 is held by the toe box 22, the tongue 30, and the upper 34.

[0070] In at least one aspect, the foamed peroxide-crosslinked polyolefin elastomer comprises a silane-grafted polyolefin component (e.g., derived from residues of component A below) and an elastomer component (e.g., derived from residues of component B below). In an improvement, the elastomer component comprises one or more elastomers selected from the group consisting of ethylene-vinyl acetate copolymers, polyolefin elastomers, olefin block copolymers, polyoctenamer, anhydride-modified ethylene copolymers, ethylene-propylene diene terpolymers, and combinations thereof. Characteristically, the silane-grafted polyolefin component and the elastomer component are crosslinked via C-C bonds. Furthermore, the foamed peroxide-crosslinked polyolefin elastomer comprises a plurality of closed-cell structures. Advantageously, the foamed peroxide-crosslinked polyolefin elastomer is substantially free of silane crosslinking and substantially free of water during formation. In an improvement, the amounts of additives and elastomer polymers are sufficient to make the melting temperature of the crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer, as measured by a differential scanning calorimeter, greater than 100°C. In a further improvement, the amount of additives and one or more elastomeric polymers is sufficient to give the tear strength of the foamed peroxide-crosslinked polyolefin elastomer to be about 6.0 kg / cm to 13.0 kg / cm. In a further improvement, the amount of additives and one or more elastomeric polymers present is sufficient to give the Shore C hardness of the foamed peroxide-crosslinked polyolefin elastomer to be 35 to 45. In a further improvement, the elastomer component includes an ethylene-propylene diene terpolymer and / or an ethylene-vinyl acetate copolymer. In a further improvement, the elastomer component includes an olefin block copolymer. In some improvements, the amount of additives and one or more elastomeric polymers present is sufficient to give the melt temperature of the crystalline region in the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, to be greater than 100°C, the tear strength of the foamed peroxide-crosslinked polyolefin elastomer to be about 6.0 kg / cm to 13.0 kg / cm, and the Shore C hardness of the foamed peroxide-crosslinked polyolefin elastomer to be 35 to 45. In an improvement, the elastomer component comprises an ethylene-propylene diene terpolymer and / or an ethylene-vinyl acetate copolymer. In a further improvement, the elastomer component comprises an olefin block copolymer.

[0071] Examples of suitable additives include, but are not limited to, silicone rubber, zinc oxide, stearic acid, silane-modified amorphous polyalphaolefins, trans-polyoctene rubber (TOR), silica / silica, titanium dioxide, organic pigments (e.g., red organic pigments, blue organic pigments), triallyl cyanurate, and combinations thereof. In improvements, additives include activators, accelerators, and crosslinking agents. Zinc oxide is an example of an activator. Triallyl cyanurate can be characterized as an active agent, crosslinking agent, accelerator, or activator. In improvements, stearic acid and / or zinc oxide are used to achieve properties related to melt temperature, tear strength, and Shore C hardness.

[0072] In the improvement, the elastomer component includes ethylene-vinyl acetate copolymers and / or ethylene-propylene diene terpolymers, as well as components selected from the group consisting of ethylene-vinyl acetate copolymers, polyolefin elastomers, olefin block copolymers, polyoctene, anhydride-modified ethylene copolymers, ethylene-propylene terpolymers, and combinations thereof. The silane-grafted polyolefin component and the elastomer component are cross-linked via C-C bonds. The foamed peroxide-crosslinked polyolefin elastomer includes multiple closed cells that contribute to moisture resistance. In particular, the multiple closed cells comprise a network of interconnected closed cells. Characteristically, the foamed peroxide-crosslinked polyolefin elastomer is substantially free of silane crosslinking and substantially free of water during formation. In the improvement, the water content of the initially formed foamed peroxide-crosslinked polyolefin elastomer is less than about 0.10% by weight (foamed peroxide-crosslinked polyolefin elastomer), particularly less than or equal to about 0.05% by weight. Advantageously, the foamed peroxide-crosslinked polyolefin elastomer and / or the shoe midsole are substantially free of condensation catalysts or their residues.

[0073] refer to Figure 3A and 3B The midsole 18 and the foamed peroxide-crosslinked polyolefin elastomer 52 have a shape configured to be positioned above the outsole of the shoe. The midsole 18 has an elongated shape, having a first portion 54 configured to contact the rearfoot of the foot, a second portion 56 configured to contact the midfoot of the foot, and a third portion 58 configured to contact the forefoot of the foot. Thus, the outer contour 60 of the midsole 18 has a size sufficient to completely enclose the foot. Typically, the third portion 58 is wider than the second portion 56 and / or the first portion 54. The midsole 18 may optionally include one or both of the outer layers 60 and 62. In improvements, the outer layers 60 and 62 have a thickness from about 0.5 micrometers to about 10 micrometers when present. The midsole provides stability to the foot. The midsole described herein can withstand all types of typical footwear challenges, namely terrain, the user's weight, pressure sources generated during walking or running, etc.

[0074] In some aspects, foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles include approximately 100 closed cells / mm. 3 Up to 1×10 5 One closed pore / mm 3 In some improvements, the foamed peroxide-crosslinked polyolefin elastomer and / or shoe midsole includes at least 50 closed cells / mm in a preferred increasing order. 3 100 closed cells / mm 3 200 closed cells / mm 3 300 closed cells / mm 3 or 400 closed pores / mm 3In a further improvement, the foamed peroxide-crosslinked polyolefin elastomer and / or shoe midsole includes, in ascending order of preference, up to 1×10 5 One closed pore / mm 3 1×10 4 One closed pore / mm 3 1×10 3 One closed pore / mm 3 or 500 closed pores / mm 3 The SEM micrographs described below show that the closed pores form a connected network that acts as a barrier to water (i.e., moisture) penetration into the foamed peroxide-crosslinked polyolefin elastomer. This is confirmed by the water absorption test described below, in which the foamed peroxide-crosslinked polyolefin elastomer and / or shoe midsole exhibit a water absorption rate of less than 0.15% (e.g., ASTM D 1056).

[0075] Advantageously, foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles exhibit increased elasticity and reduced shrinkage compared to many prior art formulations. In particular, the foamed peroxide-crosslinked polyolefin elastomers and shoe midsoles each have a melt temperature (i.e., melting point) greater than about 100°C of the crystalline region. The melt temperature of the crystalline region can be determined by DSC measurements as described below. In the improved formulation, the melt temperatures of the crystalline regions of the foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles are preferably greater than 100°C, 102°C, 105°C, 106°C, 107°C, 110°C, or 115°C in an increasing order. Typically, the melt temperatures of the crystalline regions of the foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles are preferably less than 110°C, 120°C, 130°C, 140°C, or 150°C in an increasing order. The melt temperature of the crystalline region is an important parameter for controlling the shrinkage of the foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles. When foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles are not subjected to temperatures equal to or higher than the melting temperature of the crystalline region, the crystals do not melt, thus holding the parts together and resulting in low shrinkage. Shrinkage is an important factor in the assembly process, storage, and maintaining the dimensional stability of parts during storage and transportation. In addition to reduced shrinkage, foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles also exhibit improved elasticity. Figure 4 A comparative graph of silane-grafted and ungrafted POEs using a shear rheometer with a rotating cylinder is provided. Silane-grafted POEs were observed to provide higher torque, indicating a higher crosslinking density, which in turn indicates higher elasticity. Therefore, silane-grafted polymers are chosen to manage elasticity.

[0076] In a variant, the silane-grafted polyolefin component comprises one or more silane-grafted polyolefin components. Silane grafting is facilitated by combining a silane mixture with one or more polyolefins. In an improvement, one or more silane-grafted polyolefin components independently comprise silane functional groups grafted onto one or more polyolefins. Suitable silane functional groups are described by Formula I:

[0077]

[0078] R1, R2, and R3 are each independently H or C. 1-8 Alkyl groups. In the improvements, R1, R2, and R3 are each independently methyl, ethyl, propyl, or butyl. Typically, the silane-grafted polyolefin component is formed from the required polyolefin prior to combination with the elastomer component (component B), as described in more detail below.

[0079] In one improvement, the silane-grafted polyolefin component includes a first silane-grafted polyolefin, a second silane-grafted polyolefin, and optionally one or more additional silane-grafted polyolefins. In this improvement, both the first and second silane-grafted polyolefins independently include internal CC crosslinks. In a further improvement, the first silane-grafted polyolefin is crosslinked with the second silane-grafted polyolefin and the elastomer component via CC bonds. In an even further improvement, the second silane-grafted polyolefin is crosslinked with the elastomer component via CC bonds. In a variant, the first silane-grafted polyolefin has a first melt index of less than about 5, while the second silane-grafted polyolefin has a second melt index of greater than about 20. Alternatively, the first silane-grafted polyolefin has a higher weight-average molecular weight than the second silane-grafted polyolefin.

[0080] In the variant, the silane-grafted polyolefin component (e.g., a first silane-grafted polyolefin and a second silane-grafted polyolefin) is selected from the group consisting of silane-grafted ethylene-α-olefin copolymers, silane-grafted polyolefin elastomers (POE), silane-grafted olefin block copolymers, and combinations thereof. Each of these silane-grafted ethylene α-olefin copolymers, silane-grafted polyolefin elastomers (POE), and silane-grafted olefin block copolymers can be formed using at least one base polyolefin, as described in more detail below.

[0081] In other improvements, the first silane-grafted polyolefin and / or the second silane-grafted polyolefin (and / or any additional silane-grafted polymer in component A) are selected from the group consisting of silane-grafted olefin homopolymers, blends of silane-grafted homopolymers, copolymers of two or more olefins grafted with silane, blends of copolymers of two or more olefins grafted with silane, and blends of silane-grafted olefin homopolymers with copolymers of two or more olefins grafted with silane.

[0082] In other improvements, the first silane-grafted polyolefin and the second silane-grafted polyolefin (and / or any other silane-grafted polymer in component A) are each independently selected from ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, C 9-16 Silane-grafted homopolymers or silane-grafted copolymers of olefins in the group consisting of olefins and combinations thereof.

[0083] In another improvement, the first silane-grafted polyolefin and the second silane-grafted polyolefin (and / or any other silane-grafted polymer in component A) independently include polymers selected from the group consisting of silane-grafted block copolymers, silane-grafted ethylene-propylene-diene monomer polymers, silane-grafted ethylene-octene copolymers, silane-grafted ethylene-butene copolymers, silane-grafted ethylene-α-olefin copolymers, silane-grafted polymers of 1-butene and ethylene, silane-grafted polypropylene homopolymers, silane-grafted methyl methacrylate-butadiene-styrene polymers, silane-grafted polymers having isotactic propylene units with random distribution of ethylene, silane-grafted styrene block copolymers, silane-grafted styrene-ethylene-butene-styrene copolymers, and combinations thereof.

[0084] It should be understood that each of these examples of the first silane-grafted polyolefin and the second silane-grafted polyolefin is formed from a base polyolefin or a polymer without silane grafting.

[0085] In some aspects, the elastomer component includes an ethylene vinyl acetate copolymer. Typically, the ethylene vinyl acetate copolymer has a vinyl acetate content of about 10 to 50 mol%. In improvements, the ethylene vinyl acetate copolymer has a vinyl acetate content of at least 5 mol%, 10 mol%, 15 mol%, 20 mol%, or 25 mol%. In further improvements, the ethylene vinyl acetate copolymer has a vinyl acetate content of up to 60 mol%, 50 mol%, 40 mol%, 35 mol%, or 30 mol%.

[0086] In some respects, the elastomer components include those selected from ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, and C. 9-16 Copolymers of olefins from the group consisting of olefins and combinations thereof. In improvements, the elastomeric component includes polymers selected from the group consisting of block copolymers, ethylene-propylene-diene monomer polymers, ethylene-octene copolymers, ethylene-butene copolymers, ethylene-α-olefin copolymers, polymers of 1-butene and ethylene, polypropylene homopolymers, methacrylate-butadiene-styrene polymers, polymers having isotactic propylene units with random distributions of ethylene, styrene block copolymers, styrene-ethylene-butene-styrene copolymers, and combinations thereof. It should be understood that the elastomeric component may also include any polymers listed below for the base polyolefin.

[0087] In some aspects, foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles include additives selected from the group consisting of silicone rubber, zinc oxide, stearic acid, silane-modified amorphous polyalphaolefin, trans-polyoctene rubber (TOR), silica / silica, titanium dioxide, organic pigments (e.g., red organic pigments, blue organic pigments), triallyl cyanurate, and combinations thereof. In improvements, the additives include activators, accelerators, and crosslinking agents. Zinc oxide is an example of an activator. Triallyl cyanurate can be characterized as an active agent, crosslinking agent, accelerator, or activator. In improvements, stearic acid and / or zinc oxide are used to achieve properties related to melt temperature, tear strength, and Shore C hardness. In the improvements, these additives are present independently of the total weight of the foamed peroxide-crosslinked polyolefin elastomer and / or the shoe midsole in the following amounts: silicone rubber in the amount of about 0.0% to 10.0% by weight or about 1% to 18.0% by weight; zinc oxide in the amount of about 0% to 8% by weight or about 1% to 5.0% by weight; stearic acid in the amount of about 0% to 8% by weight or 1% to 2.0% by weight; silane-modified amorphous polyalphaolefin in the amount of about 0.0% to 10.0% by weight or about 1% to 6.0% by weight; and trans-polyoctene rubber (TOR) in the amount of about 0.0% by weight. The amount of silica / silica is from about 0.0% to 18.0% by weight or about 1% to 12.0% by weight; the amount of titanium dioxide is from about 0.0% to 12.0% by weight or about 1% to 10.0% by weight; the amount of organic pigment is from about 0% to 2% by weight or about 0.01% to 1.5% by weight; the amount of di(tert-butylperoxyisopropyl)benzene is from about 0% to 5% by weight or about 0.5% to 3.0% by weight; and the amount of triallyl cyanurate is from about 0.01% to 0.3% by weight or 0.05% to 0.2% by weight. The foamed peroxide-crosslinked polyolefin elastomer and / or shoe midsole may also include residues of foaming agents (e.g., azodicarbonamide and modified azodicarbonamide), crosslinking agents, addition accelerators, etc.

[0088] In the improvement, the first silane-grafted polyolefin has a content of less than 0.86 g / cm³. 3 The density and the second silane-grafted polyolefin has a crystallinity of less than 40%.

[0089] In one improvement, the first silane-grafted polyolefin is present in an amount of about 60 to 80% by weight of the total weight of the shoe midsole, while the second silane-grafted polyolefin is present in an amount of about 20 to 40% by weight of the total weight of the shoe midsole.

[0090] Typically, foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles have a resilience of at least 60%. In some improvements, the foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles have a resilience of at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% in a preferred increasing order. It should be noted that 100% is the maximum achievable resilience performance.

[0091] Advantageously, the midsole exhibits a compression deformation of approximately 1.0% to approximately 80.0%, as measured after 6 hours of testing at 50°C (50% compression). Advantageously, the midsole exhibits a compression deformation of approximately 1.0% to approximately 76.8%, as measured after 6 hours of testing at 50°C (50% compression). In an improved version, the midsole exhibits a compression deformation of approximately 1.0% to approximately 67.0%, as measured after 6 hours of testing at 50°C (50% compression).

[0092] In some cases, the specific gravity of foamed peroxide-crosslinked polyolefin elastomers or shoe midsoles is approximately 0.1 g / cm³. 3 Approximately 0.30 g / cm³ 3 In the improvement, the specific gravity of the foamed peroxide-crosslinked polyolefin elastomer or shoe midsole, in a preferential increasing order, is at most 0.60 g / cm³. 3 0.50g / cm 3 0.40g / cm 3 0.30g / cm 3 Or 0.25g / cm 3 In further improvements, the specific gravity of the foamed peroxide-crosslinked polyolefin elastomer or shoe midsole, in order of increasing preference, is at least 0.05 g / cm³. 3 0.10 g / cm 3 0.12g / cm 3 0.13g / cm 3 or 0.15g / cm 3 0.20g / cm 3 .

[0093] In some aspects, the foamed peroxide-crosslinked polyolefin elastomer and / or shoe midsole exhibits a glass transition temperature of approximately -75°C to approximately -25°C. In improvements, the glass transition temperature exhibited by the foamed peroxide-crosslinked polyolefin elastomer and / or shoe midsole is at least -75°C, -65°C, -60°C, -50°C, or -45°C, in a preferred increasing order. In further improvements, the glass transition temperature exhibited by the foamed peroxide-crosslinked polyolefin elastomer and / or shoe midsole is at most -25°C, -30°C, -40°C, or -50°C, in a preferred increasing order. The glass transition temperature can be determined by differential scanning calorimetry (DSC) using secondary heating at a rate of 5°C / min or 10°C / min.

[0094] refer to Figure 3C A method for preparing the above-mentioned foamed peroxide crosslinked polyolefin elastomer and / or shoe midsole is provided. The method includes step a. 1 The method further comprises, wherein component (box 100) is used to form component A (box 102), and component (box 100) herein comprises a mixture of a first silane-grafted polyolefin and a second silane-grafted polyolefin (and optionally, one or more additional silane-grafted polyolefins). The method also includes step a. 2 The component (box 104) is used to form a masterbatch (i.e., component B) (box 106), which includes at least one elastomer (e.g., an elastomer composition). Typically, the masterbatch (i.e., component B) also includes a foaming agent and a peroxide.

[0095] As described above, the elastomer component includes one or more elastomer polymers selected from the group consisting of ethylene-vinyl acetate copolymers, polyolefin elastomers, olefin block copolymers, polyoctene, anhydride-modified ethylene copolymers, ethylene-propylene diene terpolymers, and combinations thereof. In the improvement, component A and component B in step b... 1 ) and b 2 The components are granulated independently, as shown in boxes 108 and 110, respectively. As shown in box 112, in step c), component A and the masterbatch (i.e., component B) are mixed to form a reaction mixture. In an improvement, as shown in box 114, the reaction mixture is formed into spherical shapes d). In an improvement, 50–90 wt% of component A is mixed with 50–10 wt% of component B. In an improvement, 60–80 wt% of component A is mixed with 40–20 wt% of component B. In another improvement, 65–75 wt% of component A is mixed with 35–25 wt% of component B.

[0096] In step e), as shown in box 116, the reaction mixture is reacted under a moisture-free condition at the reaction temperature for a predetermined time to form a foamed peroxide-crosslinked polyolefin elastomer, such that the first silane-grafted polyolefin is crosslinked with the second silane-grafted polyolefin and the elastomer component via C-C bonds, and the second silane-grafted polyolefin is crosslinked with the elastomer component via C-C bonds. In other words, the silane-grafted polyolefin component is crosslinked with the elastomer component via C-C bonds.

[0097] The reaction mixture also reacts, causing the foamed peroxide-crosslinked polyolefin elastomer to comprise multiple closed cells. The predetermined time period and reaction temperature will depend on the specific composition of component A and the masterbatch (i.e., component B). Typically, the predetermined time period is about 200–600 seconds, and the reaction temperature is about 160–200°C. In some variations, the reaction mixture reacts in a molding apparatus. In some variations, the method further includes the step of molding the foamed peroxide-crosslinked polyolefin elastomer into a shoe midsole. In improvements, this can be combined with the reaction step of the reaction mixture. Molding can be performed by any suitable molding process, including but not limited to compression molding, injection molding, injection compression molding, and supercritical injection molding. The details of the resulting foamed peroxide-crosslinked polyolefin elastomer or shoe midsole are the same as described above. In improvements, the amounts of additives and elastomer polymers are sufficient to make the melt temperature of the crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, greater than 100°C. In a further improvement, the amount of additives and one or more elastomeric polymers is sufficient to give the foamed peroxide-crosslinked polyolefin elastomer a tear strength of about 6.0 kg / cm to 13.0 kg / cm. In a further improvement, the amount of additives and one or more elastomeric polymers is sufficient to give the foamed peroxide-crosslinked polyolefin elastomer a Shore C hardness of 35 to 45. In some improvements, the amount of additives and one or more elastomeric polymers is sufficient to give the melt temperature of the crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, greater than 100°C, a tear strength of about 6.0 kg / cm to 13.0 kg / cm, and a Shore C hardness of 35-45. In some improvements, the elastomer component includes an ethylene-propylene-diene terpolymer and / or an ethylene-vinyl acetate copolymer. In a further improvement, the elastomer component includes an olefin block copolymer. The details regarding the composition of the masterbatch, the method of using the masterbatch, and the characteristics of the resulting patches (representing mesopores) are the same as those described in the examples above and below.

[0098] In some improvements, the additives are present independently as the following weight percentages of the total masterbatch: silicone rubber at least 0.0 wt%, 1.0 wt%, 3.0 wt%, 5.0 wt%, 8.0 wt%, or 10.0 wt%, and at most 20.0 wt%, 18.0 wt%, 15.0 wt%, 13.0 wt%, 12.0 wt%, or 10.0 wt%, in the preferred order; zinc oxide at least 0.0 wt%, 1.0 wt%, 3.0 wt%, 5.0 wt%, 8.0 wt%, or 10.0 wt%, and at most 20.0 wt%, 15.0 wt%, 14.0 wt%, or 13.0 wt%, in the preferred order. The amount of stearic acid is at least 0.0 wt%, 1.0 wt%, 3.0 wt%, 5.0 wt%, 8.0 wt%, or 10.0 wt%, and at most 15.0 wt%, 13.0 wt%, 12.0 wt%, 10.0 wt%, 8.0 wt%, or 6.0 wt%, in the preferred increasing order; the amount of silane-modified amorphous polyα-olefin is at least 0.0 wt%, 1.0 wt%, 3.0 wt%, 5.0 wt%, 8.0 wt%, or 10.0 wt%, and at most 25.0 wt%, 20.0 wt%, 18.0 wt%, 15.0 wt%, 13.0 wt%, or 6.0 wt%, in the preferred increasing order; the amount of silane-modified amorphous polyα-olefin is at least 0.0 wt%, 1.0 wt%, 3.0 wt%, 5.0 wt%, 8.0 wt%, or 10.0 wt%, and at most 25.0 wt%, 20.0 wt%, 18.0 wt%, 15.0 wt%, 13.0 wt%, or 6.0 wt%, in the preferred increasing order. The amount of trans-polyoctene rubber (TOR) is at least 0.0 wt%, 1.0 wt%, 3.0 wt%, 5.0 wt%, 8.0 wt%, or 10.0 wt%, and at most 25.0 wt%, 20.0 wt%, 18.0 wt%, 15.0 wt%, 13.0 wt%, 12.0 wt%, or 10.0 wt%, in the preferred order; the amount of silica / silica is at least 0.0 wt%, 1.0 wt%, 3.0 wt%, 5.0 wt%, 8.0 wt%, 10.0 wt%, or 15 wt%, and at most 35 wt%, 30 wt%, 25 wt%, or 12.0 wt%, in the preferred order. 0.0 wt%, 20.0 wt%, 18.0 wt%, 15.0 wt%, 13.0 wt%, 12.0 wt%, or 10.0 wt%; the amount of titanium oxide, in the preferred increasing order, is at least 0.0 wt%, 1.0 wt%, 3.0 wt%, 5.0 wt%, 8.0 wt%, or 10.0 wt%, and at most 25.0 wt%, 20.0 wt%, 18.0 wt%, 15.0 wt%, 13.0 wt%, 12.0 wt%, or 10.0 wt%; the amount of peroxide (e.g., di(tert-butylperoxyisopropyl)benzene), in the preferred increasing order, is at least 0.0 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, or 5.0 wt%.The amount of 0% by weight, in preferred order, is at most 10.0% by weight, 9.0% by weight, 8.0% by weight, 7.0% by weight, 6.0% by weight, 5.0% by weight, or 4.0% by weight; and the amount of triallyl cyanurate, in preferred order, is at least 0.0% by weight, 0.001% by weight, 0.01% by weight, 0.05% by weight, 0.1% by weight, or 0.5% by weight, in preferred order, and at most 1% by weight, 0.9% by weight, 0.8% by weight, 0.7% by weight, 0.6% by weight, 0.5% by weight, or 0.3% by weight. Foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles may also include residues of foaming agents (e.g., azodicarbonamide and modified azodimethylamine), crosslinking agents, addition accelerators, etc.

[0099] Specifically, as described above, the silane-grafted polyolefin component may include one or more silane-grafted polyolefin components. The silane-grafted polyolefin component is formed by grafting at least one base polyolefin with silane. Silane grafting is achieved by combining a silane mixture with one or more polyolefins. The silane mixture may include one or more silanes, oils, peroxides, antioxidants, and / or other components such as a grafting initiator. The synthesis of the silane-grafted polyolefin component may be carried out as described in the grafting steps outlined in U.S. Patent Application Serial No. 15 / 836,436 (titled “Sole, Composition, and Method of Manufacturing the Same”), filed December 8, 2017, using a single-step Monosil process or a two-step Sioplas process, the entire contents of which are incorporated herein by reference. In an improved embodiment, the silane is a vinylalkoxysilane having the following formula:

[0100]

[0101] R1, R2, and R3 are each independently H or C. 1-8 Alkyl groups. Examples of silanes include, but are not limited to, vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltripropoxysilane. Therefore, a polyolefin component grafted with one or more silanes independently includes a silane functional group of formula I grafted thereon:

[0102]

[0103] R1, R2, and R3 are each independently H or C. 1-8 Alkyl groups. In the improvements, R1, R2, and R3 are each independently methyl, ethyl, propyl, or butyl. Typically, the silane-grafted polyolefin component is formed from the necessary polyolefin before being combined with the masterbatch (component B), as described in more detail below. When the silane-grafted polyolefin component comprises multiple silane-grafted polyolefins, a mixture of base polyolefins can be formed, followed by silane grafting. Alternatively, the polyolefins can be silane-grafted individually and then combined.

[0104] In this variant, the silane-grafted polyolefin component comprises a first silane-grafted polyolefin and a second silane-grafted polyolefin, respectively formed from a first base polyolefin and a second base polyolefin. Therefore, the first silane-grafted polyolefin can be crosslinked with the second silane-grafted polyolefin and the elastomer component via C-C bonds. Furthermore, the second silane-grafted polyolefin can also be crosslinked with the elastomer component via C-C bonds.

[0105] In the improvement, the first silane-grafted polyolefin and the second silane-grafted polyolefin are each independently selected from the group consisting of silane-grafted ethylene α-olefin copolymers, silane-grafted olefin block copolymers, and combinations thereof.

[0106] As described above, the reaction mixture includes a peroxide. In an improvement, the peroxide comprises a peroxide component selected from the group consisting of hydrogen peroxide, alkyl hydroperoxides, dialkyl peroxides, and diacyl peroxides. Examples of peroxides include, but are not limited to, di(tert-butylperoxyisopropyl)benzene, di-tert-butyl peroxide, tert-butylisopropylbenzene peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di(tert-butyl-peroxy)hexyne-3, 1,3-bis(tert-butyl-peroxy-isopropyl)benzene, n-butyl-4,4-bis(tert-butyl-peroxy)valerate, benzoyl peroxide, tert-butyl benzoate, tert-butyl peroxycarbonate isopropyl tert-butyl percarbonate, tert-butyl perbenzoate, bis(2-methylbenzoyl) peroxide, bis(4-methylbenzoyl) peroxide, tert-butyl peroctanoate, hydrogen peroxide, and other peroxides. Organic peroxides in the group consisting of cumene peroxide, methyl ethyl ketone peroxide, lauroyl peroxide, tert-butyl peracetate, di-tert-amyl peroxide, tert-amyl peroxybenzoate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, α,α'-bis(tert-butylperoxy)-1,3-diisopropylbenzene, α,α'-bis(tert-butylperoxy)-1,4-diisopropylbenzene, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyne, 2,4-dichlorobenzoyl peroxide, and combinations thereof.

[0107] In some respects, the basic polyolefin is selected from ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, C 9-2 Copolymers of olefins in the group consisting of 0-olefins and combinations thereof. Examples of comonomers include, but are not limited to, aliphatic C-olefins. 2-20 α-Alkenes. Suitable aliphatic C 2-20Examples of α-olefins include ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. In improvements, the comonomer is vinyl acetate. In some embodiments, the amount of comonomer can be greater than 0 wt% to about 12 wt%, including greater than 0 wt% to about 9 wt%, and greater than 0 wt% to about 7 wt%, based on the weight of the polyolefin. In some embodiments, the amount of comonomer is greater than about 2 mol% of the final polymer, including greater than about 3 mol% and greater than about 6 mol%. The comonomer content can be less than or equal to about 30 mol%. The copolymer can be a random or block (multiphase) copolymer. In some embodiments, the polyolefin is a random copolymer of propylene and ethylene.

[0108] In some aspects, the base polyolefin is selected from the group consisting of olefin homopolymers, blends of homopolymers, copolymers made from two or more olefins, blends of copolymers each made from two or more olefins, and blends of olefin homopolymers and copolymers made from two or more olefins. The olefin may be selected from ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, and other higher 1-olefins. In some aspects, polyethylene used for at least one polyolefin can be classified into several types, including but not limited to LDPE (low-density polyethylene), LLDPE (linear low-density polyethylene), and HDPE (high-density polyethylene). In other aspects, polyethylene can be classified into ultra-high molecular weight (UHMW), high molecular weight (HMW), medium molecular weight (MMW), and low molecular weight (LMW). In other aspects, polyethylene may be an ultra-low-density ethylene elastomer.

[0109] In the variant, the base polyolefin component is selected from the group consisting of ethylene α-olefin copolymers, polyolefin elastomers (POE), olefin block copolymers, and combinations thereof.

[0110] In other improvements, the base polyolefin is selected from the group consisting of olefin homopolymers, blends of homopolymers, copolymers of two or more olefins, blends of copolymers of two or more olefins, and blends of olefin homopolymers and copolymers of two or more olefins.

[0111] In another improvement, the basic polyolefin includes polymers selected from the group consisting of block copolymers, ethylene propylene diene monomer polymers, ethylene octene copolymers, ethylene butene copolymers, ethylene α-olefin copolymers, polymers of 1-butene and ethylene, polypropylene homopolymers, silane-grafted methacrylate-butadiene-styrene polymers, silane-grafted polymers of isotactic propylene units with random ethylene distribution, styrene block copolymers, styrene-ethylene-butene-styrene copolymers, and combinations thereof.

[0112] One or more base polyolefins may be polyolefin elastomers, including olefin block copolymers, ethylene α-olefin copolymers, propylene α-olefin copolymers, isotactic propylene units with random ethylene distribution, polyolefin elastomers / ethylene-octene copolymers, styrene-ethylene-butene-styrene copolymers, EPDM, EPM, or mixtures of two or more of these materials. Specific examples of base polyolefins are as follows. Exemplary olefin block copolymers include those marketed under the trade name INFUSE. TM Those sold (e.g., INFUSE 9530, INFUSE 9817, INFUSE 9900, and INFUSE 9107) are available from (Dow Chemical Company); and under the trade name SEPTON TM Those sold by V-SERIES (e.g., SEPTON V 9641), styrene-ethylene-butene-styrene block copolymers are available from Kuraray. An example of a styrene-ethylene-butene-styrene copolymer (SEBS) is TUFTEC P 1083 (Asahi Kase). Exemplary ethylene α-olefin copolymers include those marketed under the trade name TAFMER. TM (e.g., TAFMER DF710 and TAFMER DF605) (Mistsui Chemicals, Inc.) and ENGAGE TM (For example, those sold by Dow Chemical Company, such as ENGAGE 8150). Exemplary propylene α-olefin copolymers include those marketed under the trade name VISTAMAXX. TM 6102 grade (Exxon Mobil Chemical Company), TAFMER TM XM (Mitsui ChemicalCompany) and VERSIFY TMThose sold by Dow Chemical Company. An example of isotactic propylene units with a random ethylene distribution is VISTAMAXX 8880 (Exxon Mobil Chemical Company). A vinyl polymer / polyolefin elastomer is Tafmer K8505S (Mitsui Chemicals, Inc.). Exemplary ethylene-octene copolymers include Engage 8677 and Engage 8407 (Dow Chemical Company), FORTIFY C11075DF and FORTIFY C05075DF (Sabic), SOLUMER 871L and SOLUMER 8705L (SK Global Chemical). An example of a polyolefin elastomer / ethylene-octene copolymer is ENGAGE 8401. Examples of ethylene-butene are Engage 7467 / 7457 / 7447 / 7367 / 7270 / 7256 (Dow Chemical Company). An exemplary polymer of 1-butene and ethylene is LC 165LG Chemical. An exemplary polypropylene homopolymer is MOSTEN NB 425 (Unipetrol RPA). An exemplary methacrylate-butadiene-styrene (MBS) is PARALOID EXL 3691 (Dow Chemical Company).

[0113] As described above, component B may include ethylene vinyl acetate copolymer. It should be understood that the elastomeric component may also include any polymer listed for the base polyolefins listed below.

[0114] In one improvement, component A comprises one or more olefin block copolymers, in an amount of about 50–96% by weight of the total weight of component A. In another improvement, component A comprises an olefin block copolymer and an ethylene octene copolymer, each in an independent amount of about 30–70% by weight of the total weight of component A. In yet another improvement, component A comprises a mixture of olefin block copolymers and an ethylene octene copolymer, each in an independent amount of about 30–70% by weight of the total weight of component A. In yet another improvement, component A comprises an olefin block copolymer and a styrene-ethylene-butene-styrene copolymer, each in an independent amount of about 30–70% by weight of the total weight of component A.

[0115] In some respects, at least one polyolefin may have a molecular weight distribution (Mw / Mn) of less than or equal to about 5, less than or equal to about 4, about 1 to about 3.5, or about 1 to about 3.

[0116] The base polyolefin may be present in an amount greater than 0 wt% to about 100 wt% of the composition. In some embodiments, the amount of the polyolefin elastomer is about 30 wt% to about 70 wt%. In some aspects, at least one polyolefin supplied to the extruder may comprise about 50 wt% to about 80 wt% of an ethylene α-olefin copolymer, including about 60 wt% to about 75 wt% and about 62 wt% to about 72 wt%.

[0117] At least one base polyolefin may have a melt index of about 20.0 g / 10 min to about 3,500 g / 10 min, measured at 190 °C and under a 2.16 kg load, including about 250 g / 10 min to about 1,900 g / 10 min and about 300 g / 10 min to about 1,500 g / 10 min. In some aspects, at least one polyolefin has a fractional melt index of about 0.5 g / 10 min to about 3,500 g / 10 min.

[0118] In some respects, the density of at least one basic polyolefin is less than about 0.90 g / cm³. 3 Less than approximately 0.89 g / cm³ 3 Less than approximately 0.88 g / cm³ 3 Less than approximately 0.87 g / cm³ 3 Less than approximately 0.86 g / cm³ 3 Less than approximately 0.85 g / cm³ 3 Less than approximately 0.84 g / cm³ 3 Less than approximately 0.83 g / cm³ 3 Less than approximately 0.82 g / cm³ 3 Less than approximately 0.81 g / cm³ 3 or less than approximately 0.80 g / cm³ 3 In other respects, the density of at least one polyolefin may be about 0.85 g / cm³. 3 Approximately 0.89 g / cm³ 3 Approximately 0.85 g / cm³ 3 Approximately 0.88 g / cm³ 3 Approximately 0.84 g / cm³ 3 Approximately 0.88 g / cm³ 3 or approximately 0.83 g / cm³ 3 Approximately 0.87 g / cm³ 3 In other aspects, its density is approximately 0.84 g / cm³. 3 Approximately 0.85 g / cm³ 3 Approximately 0.86 g / cm³ 3 Approximately 0.87 g / cm³ 3 Approximately 0.88 g / cm³ 3 Or approximately 0.89 g / cm³ 3 .

[0119] The crystallinity percentage of the base polyolefin can be less than about 60%, less than about 50%, less than about 40%, less than about 35%, less than about 30%, less than about 25%, or less than about 20%. The crystallinity percentage can be at least about 10%. In some respects, the crystallinity is in the range of about 2% to about 60%.

[0120] Table 1 provides examples of general formulations for components A and B.

[0121] Table 1. Exemplary compositions of components A and B

[0122]

[0123] In another embodiment, a masterbatch (i.e., component B) for forming the midsole is provided. The masterbatch includes at least one elastomer, typically a mixture of elastomers. Typically, the masterbatch also includes a foaming agent, a peroxide, additives, and the elastomer component. Examples of elastomers are selected from the group consisting of ethylene-vinyl acetate copolymers, polyolefin elastomers, olefin block copolymers, polyoctene, anhydride-modified ethylene copolymers, ethylene-propylene diene terpolymers, and combinations thereof. Examples of additives include those selected from the group consisting of silicone rubber, zinc oxide, stearic acid, silane-modified amorphous polyalphaolefins, trans-polyoctene rubber (TOR), silica / silica, titanium dioxide, organic pigments (e.g., red organic pigments, blue organic pigments), triallyl cyanurate, and combinations thereof. In improvements, the additives include activators, accelerators, and crosslinking agents. Zinc oxide is an example of an activator. Triallyl cyanurate can be characterized as an additive, crosslinking agent, accelerator, or activator. In the improvements, stearic acid and / or zinc oxide are used to achieve properties related to melt temperature, tear strength, and Shore C hardness. An example of a peroxide is di(tert-butylperoxyisopropyl)benzene. Other examples of peroxides are as described above.

[0124] The masterbatch is suitable for combination (e.g., mixing) with component A to form a reaction mixture. Herein, "suitable for combination" means that the masterbatch is in granular or powder form suitable for combination with component A. As described herein, component A comprises a mixture of a first silane-grafted polyolefin and a second silane-grafted polyolefin (and optionally, one or more additional silane-grafted polyolefins). The reaction mixture is reacted under ahydrous conditions at a reaction temperature for a predetermined time to form a foamed peroxide-crosslinked polyolefin elastomer, such that the first silane-grafted polyolefin is crosslinked with the second silane-grafted polyolefin and the elastomer component via CC bonds, and the second silane-grafted polyolefin is crosslinked with the elastomer component via CC bonds. In other words, the silane-grafted polyolefin component is crosslinked with the elastomer component via CC bonds. The reaction mixture also reacts such that the foamed peroxide-crosslinked polyolefin elastomer comprises multiple closed-cell structures. The predetermined time period and reaction temperature will depend on the specific composition of component A and the masterbatch. Typically, the predetermined time period is about 200 to 600 seconds, and the reaction temperature is about 160 to 200°C. In some variations, the reaction mixture is reacted in a molding apparatus. In an improvement, the amount of additive and elastomeric polymer is sufficient to make the melt temperature of the crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, greater than 100°C. In a further improvement, the amount of additive and one or more elastomeric polymers present is sufficient to make the tear strength of the foamed peroxide-crosslinked polyolefin elastomer from about 6.0 kg / cm to 13.0 kg / cm. In a further improvement, the amount of additive and one or more elastomeric polymers present is sufficient to make the Shore C hardness of the foamed peroxide-crosslinked polyolefin elastomer from 35 to 45. In some improvements, the amount of additive and one or more elastomeric polymers present is sufficient to make the melt temperature of the crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer from 100°C, the tear strength of the foamed peroxide-crosslinked polyolefin elastomer from about 6.0 kg / cm to 13.0 kg / cm, and the Shore C hardness of the foamed peroxide-crosslinked polyolefin elastomer from 35 to 45. In the improved version, the elastomer component includes ethylene propylene, which includes olefin block copolymers. Details regarding the composition of the masterbatch, the method of using the masterbatch, and the resulting mesoporous property are the same as in the examples described above and below.

[0125] The following examples illustrate various embodiments of the present invention. Those skilled in the art will recognize many variations within the spirit and scope of the claims.

[0126] Foamed peroxide crosslinked polyolefin elastomer samples

[0127] The foamed peroxide-crosslinked polyolefin elastomer samples were formed by the method described above. Table 2 provides compositions, in weight percent (%), for forming component A, which includes silane-grafted polyolefin elastomers. Tables 3-1, 3-2, 3-3, and 3-4 provide compositions, in phr, for forming component B. The compositions in Tables 3-1, 3-2, 3-3, and 3-4 were used to prepare Examples 1-22 as described below. Table 4 summarizes some tests used to characterize the foamed peroxide-crosslinked polyolefin elastomers.

[0128] Table 2 Formulation of Component A

[0129] Components (wt%) A-1 A-2 A-3 Ethylene-octene copolymer #1 28.50 28.50 Ethylene-octene copolymer #2 70.00 40 Ethylene-octene copolymer #3 14.5 Ethylene α-olefin copolymer 70.00 4.5 Silane mixture 1.50 1.50 0.5

[0130] Table 3-1 Formulation of Component B

[0131]

[0132]

[0133] Table 3-2 Component B Formulation

[0134]

[0135] Table 3-3 Component B Formulation

[0136]

[0137]

[0138] Table 3-4 Component B Formulation

[0139] Components (Phr) B-10 B-11 Ethylene-vinyl acetate copolymer (EVA) grade #1 50 50 Vinyl α-olefin elastomers 50 50 ZnO 2 2 stearic acid 1 1 Di(tert-butylperoxyisopropyl)benzene 5.0 5.0 FARIDA TACE (tribenzyl cyanurate) 0.1 0.1 Modified azodicarbonamide #1 12.0 12.0 Modified azodicarbonamide #2 12.0 -

[0140] Table 4. Test methods for characterizing foamed peroxide-crosslinked polyolefin elastomer samples.

[0141]

[0142] Compression deformation can be determined as follows: The sample is compressed at 50% thickness for 6 hours at 50°C between two parallel plates (clamps). The sample is then removed from the clamps, the new thickness is measured (after 30 minutes at room temperature), and the compression deformation (C / set) is reported as a percentage. Sample dimensions: diameter: 25.4 mm / thickness: 10 mm.

[0143] Foamed peroxide-crosslinked polyolefin elastomer samples can be prepared by dry-mixing or blending the various components listed in Tables 2, 3-1, 3-2, 3-3, and 3-4 together, followed by a molding process. Examples 1-22 were prepared using an injection molding process (compression molding system) to combine component A formulations from Table 2 with component B formulations from Tables 3-1, 3-2, 3-3, or 3-4. Tables 5 through 17 summarize the compositions, molding temperatures, times, and properties of the foamed peroxide-crosslinked polyolefin elastomer samples. Table 18 provides the compositions and properties of the EVA control samples.

[0144] Table 5 Example 1

[0145]

[0146] Table 6 Example 2

[0147]

[0148] Table 7 Example 3

[0149]

[0150]

[0151] Table 5 Example 4

[0152]

[0153]

[0154] Table 8 Example 5

[0155]

[0156] Table 10 Example 6

[0157]

[0158] Table 11 Example 7

[0159]

[0160]

[0161] Table 12 Examples 8-9

[0162]

[0163]

[0164] Table 13 Examples 10-11

[0165]

[0166] Table 14 Examples 12-15

[0167]

[0168]

[0169] Table 15 Examples 16-18

[0170]

[0171]

[0172] Table 16 Example 19

[0173]

[0174] Table 17 Examples 20-22

[0175]

[0176] Table 18 EVA Control Samples

[0177]

[0178]

[0179] Feature Description

[0180] 1. Compressive load / deflection

[0181] Compression load / deflection measurements were performed using an Instron 5965 with a 100N capacity load sensor. The compression plate was a flat steel plate with a 50mm diameter, pressed onto the platform and passed through feeler gauges to a level less than 50 micrometers. The sample size was 16mm in diameter, and the test speed was 100mm / min. A custom-designed 6-step cyclic compression procedure was used at 10%, 20%, 30%, 40%, 50%, and 60% compression (6 cycles). Figures 5A to 5E Stress and strain diagrams for Examples 1-4 and EVA are provided.

[0182] Table 19 shows the energy loss from compressive load / deflection measurements.

[0183] sample Example 1 Example 2 Example 3 Example 4 EVA comparison Energy loss (J) 0.06 0.02 0.06 0.01 0.11

[0184] 2. Gel test

[0185] The gelation test was performed as follows. The initial sample weight measurement (W1) was determined. The sample was immersed in boiling xylene for 5 hours (~139°C), followed by vacuum drying at 150°C (vacuum - 25 in Hg) for 2 hours. If this drying was insufficient, the sample was placed in a vacuum oven for 48 hours (150°C). After air cooling for approximately 72 hours, the sample weight (W2) was measured. The % gel was determined as approximately W1 / W2. The results of the gelation test are listed in Table 20 below. A high gel percentage indicates a high degree of cross-linking, as the sample is significantly cross-linked.

[0186] Table 20 Gel Content

[0187] sample Example 1 Example 2 Example 3 Example 4 EVA comparison gel% 80 89 80 72 77

[0188] 3. Differential Scanning Calorimetry (DSC)

[0189] DSC is used to determine T g T m T c Crystallinity (%). Analysis was performed using a TA DiscoveryDSC 250 instrument with a Tzero disk and Tzero cap. Samples weighing approximately 5–10 mg were cut from the plaque using a razor blade. The sample was first heated from room temperature (20 °C / min) to 200 °C, then cooled to -88 °C. A second heating to 200 °C was performed (10 °C / min). The sample was purged with N2 gas at 50 ml / min. The percentage (%) crystallinity was determined using information from the second thermal cycle from the following formula:

[0190] % crystallinity = [ΔHm / ΔHm(100%)] * 100

[0191] ΔHm(100%) of LDPE = 293 J / g

[0192] DSC diagram as follows Figure 6 and Figure 7 As shown, the results are summarized in Table 21.

[0193] Table 21 DSC Characteristics

[0194] Foamed samples Tg (°C) <![CDATA[T m (℃)]]> ΔHm(J / g) Crystallinity (%) Tc (°C) Example 1 -64.9 108.2 9.5 3.2 77.9 Example 2 -55.7 63.2 11.3 3.9 78.4 Example 3 -52.6 81.8 9.3 3.2 58.8 Example 4 -56.4 43.9 12.3 4.2 44.0 EVA comparison -28.5 67.7 26.5 9.0 47.0

[0195] Measured melting point (T) m The melting point is between 40 and 120°C. As mentioned above, the melting point is an important parameter for controlling the shrinkage of foamed peroxide-crosslinked polyolefin elastomers and / or shoe midsoles. Figure 4 The combination of melting point determined by the shear rheometer and high elasticity indicates that the sample can achieve low shrinkage and higher elasticity.

[0196] 4. Dynamic mechanical analyzer measurement

[0197] The DMA temperature ramp test was conducted as follows. The DMA-Q800 was used for DMA measurements of clamping stress and modal DMA multi-frequency strain. The temperature gradient was 5°C. The temperature gradient was from 10°C to 150°C, with a strain of 1% and a frequency of 1 Hz. The foamed sample was cut to sample dimensions (length 10.0 mm, width 3.5 mm, thickness 3.0 mm). Figure 8A and 8B The results of the DMA experiment are provided. Figure 8A This is a graph showing the relationship between Tanδ and temperature. Figure 8B This is a graph showing the relationship between energy storage modulus and temperature for Examples 1-4 and EVA comparison.

[0198] Foamed samples tanδ at 30℃ Example 1 0.1099 Example 2 0.0699 Example 3 0.1082 Example 4 0.0732 EVA comparison 0.1091

[0199] It should be understood that a higher Tanδ value indicates that the material absorbs more energy. For midsole applications, a lower Tanδ value is preferable, indicating that the material is more elastic.

[0200] 5. Rheology

[0201] Figure 9 Comparative graphs of silane-grafted and ungrafted POE using a rotating cylinder shear rheometer are provided. These graphs show the curing rates of Examples 1-4 and the EVA control. Example 2 exhibits a higher crosslinking density and therefore the highest curing rate, while Example 1 exhibits the lowest crosslinking density.

[0202] 6. Long Chain Branch (LCB) Index

[0203] The Rubber Processing Analyzer (RPA) is used to determine the amount of long-chain branching. Figure 10 A graph showing the relationship between shear stress and shear rate is provided. Table 23 provides the branching index values ​​for Examples 1-4.

[0204] Table 23 Branching Index

[0205]

[0206] These experiments show that the amount of branching increases with the amount of silane.

[0207] 7. Water absorption rate

[0208] The water absorption rate of the samples was determined according to ASTM D1056. Table 24 provides the results of the water absorption test. Typically, the sample is weighed and then immersed in water. The sample is then re-weighed to determine the amount of water absorbed. No significant water was observed to enter the foam. Walter used a polymer in the prior art that they claimed allowed water to enter. Crosslinking produced by condensation chemistry requires water for crosslinking. This invention relies on the use of peroxide crosslinking with a silane-grafted polymer that is moisture-free during the process and after product formation.

[0209] Table 24 Water Absorption

[0210]

[0211] 8. Scanning electron microscope

[0212] Figures 11 to 15 provide scanning electron micrographs of samples 1-4 and the EVA control at 25× and 50×. The micrographs show the interconnected network of closed pores, which provides excellent water absorption resistance. Closed pores are pores with a diameter of approximately 10 micrometers to approximately 300 micrometers.

[0213] Although exemplary embodiments have been described above, they do not imply that these embodiments describe all possible forms of the invention. Rather, the language used in this specification is descriptive rather than restrictive, and it should be understood that various changes can be made without departing from the spirit and scope of the invention. Furthermore, features of various embodiments can be combined to form further embodiments of the invention.

Claims

1. A shoe midsole composed of a foamed peroxide-crosslinked polyolefin elastomer, comprising: Silane-grafted polyolefin components; The elastomer component comprises one or more elastomer polymers selected from the group consisting of ethylene-vinyl acetate copolymers, polyolefin elastomers, olefin block copolymers, polyoctene, anhydride-modified ethylene copolymers, ethylene-propylene-diene terpolymers, and combinations thereof, wherein the silane-grafted polyolefin component and the elastomer component are crosslinked via C-C bonds. and Additives dispersed in foamed peroxide-crosslinked polyolefin elastomers. The foamed peroxide-crosslinked polyolefin elastomer comprises multiple closed-cell structures. During its formation, the foamed peroxide-crosslinked polyolefin elastomer is free of silane crosslinking and water. Furthermore, the foamed peroxide-crosslinked polyolefin elastomer does not contain condensation catalysts or their residues. The amount of the additives and elastomer polymers is sufficient to make the melting temperature of the crystalline regions in the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, greater than 100°C.

2. The shoe midsole according to claim 1, wherein, The amount of the additive and the one or more elastomeric polymers is sufficient to give the tear strength of the foamed peroxide-crosslinked polyolefin elastomer a value of 6.0 kg / cm to 13.0 kg / cm.

3. The shoe midsole according to claim 2, wherein, The amount of the additive and the one or more elastomer polymers is sufficient to give the Shore C hardness of the foamed peroxide-crosslinked polyolefin elastomer a value of 35 to 45.

4. The shoe midsole according to claim 3, wherein, The elastomer component includes an ethylene-propylene-diene terpolymer and / or an ethylene-vinyl acetate copolymer.

5. The shoe midsole according to claim 4, wherein, The elastomer component includes an olefin block copolymer.

6. The shoe midsole according to claim 1, wherein, The additives include those selected from the group consisting of silicone rubber, zinc oxide, stearic acid, silane-modified amorphous polyalphaolefin, trans-polyoctene rubber (TOR), silica / silica, titanium dioxide, organic pigments, triallyl cyanurate, and combinations thereof.

7. The shoe midsole according to claim 1, wherein, The additives include zinc oxide and stearic acid.

8. The shoe midsole according to claim 1, wherein, The foamed peroxide crosslinked polyolefin elastomer has a shape configured to be placed in the shoe above the outsole.

9. The shoe midsole according to claim 1, wherein, The shoe midsole exhibits 1.0% to 67.0% of the compression deformation measured after testing at 50°C for 6 hours.

10. The shoe midsole according to claim 1, wherein, The plurality of closed holes includes a network of connected closed holes.

11. The shoe midsole according to claim 1, wherein, The silane-grafted polyolefin component includes a first silane-grafted polyolefin and a second silane-grafted polyolefin.

12. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin and the second silane-grafted polyolefin each independently include internal CC crosslinking.

13. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin and the second silane-grafted polyolefin are each independently selected from the group consisting of silane-grafted ethylene α-olefin copolymers, silane-grafted olefin block copolymers, and combinations thereof.

14. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin and the second silane-grafted polyolefin each independently comprise a silane functional group of formula I grafted thereon: ;and R1, R2, and R3 are each independently H or C. 1-8 alkyl.

15. The shoe midsole according to claim 14, wherein, R1, R2, and R3 are each methyl, ethyl, propyl, or butyl.

16. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin has a first melt index of less than 5, and the second silane-grafted polyolefin has a second melt index of greater than 20.

17. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin is selected from the group consisting of silane-grafted olefin homopolymers, blends of silane-grafted homopolymers, copolymers of two or more olefins grafted with silane, blends of copolymers of two or more olefins grafted with silane, and blends of silane-grafted olefin homopolymers and copolymers of two or more olefins grafted with silane.

18. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin and the second silane-grafted polyolefin are each independently selected from ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, and C. 9-16 Silane-grafted copolymers of olefins in the group consisting of olefins and combinations thereof.

19. The shoe midsole according to claim 11, wherein, The second silane-grafted polyolefin is selected from the group consisting of silane-grafted olefin homopolymers, blends of silane-grafted homopolymers, copolymers of two or more olefins grafted with silane, blends of copolymers of two or more olefins grafted with silane, and blends of silane-grafted olefin homopolymers and copolymers of two or more olefins grafted with silane.

20. The shoe midsole according to claim 11, wherein, The second silane-grafted polyolefin is a homopolymer or copolymer of an olefin grafted with silane, wherein the olefin is selected from ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, and C. 9-16 A group composed of alkenes.

21. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin and the second silane-grafted polyolefin independently include polymers selected from the group consisting of silane-grafted block copolymers, silane-grafted ethylene-propylene-diene monomer polymers, silane-grafted ethylene-octene copolymers, silane-grafted ethylene-butene copolymers, silane-grafted ethylene-α-olefin copolymers, silane-grafted polymers of 1-butene and ethylene, silane-grafted polypropylene homopolymers, silane-grafted methacrylate-butadiene-styrene polymers, silane-grafted polymers of isotactic propylene units having a random ethylene distribution, silane-grafted styrene block copolymers, silane-grafted styrene-ethylene-butene-styrene copolymers, and combinations thereof.

22. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin has a content of less than 0.86 g / cm³. 3 The density is such that the second silane-grafted polyolefin has a crystallinity of less than 40%.

23. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin is present in an amount of 60 to 80% by weight of the total weight of the shoe midsole.

24. The shoe midsole according to claim 23, wherein, The second silane-grafted polyolefin is present in an amount of 20 to 40% by weight of the total weight of the shoe midsole.

25. The shoe midsole according to claim 11, wherein, The first silane-grafted polyolefin has a higher weight-average molecular weight than the second silane-grafted polyolefin.

26. The shoe midsole according to claim 1, wherein, The elastomer component includes ethylene vinyl acetate copolymer.

27. The shoe midsole according to claim 26, wherein, The ethylene vinyl acetate copolymer has a vinyl acetate content of 10 to 50 mol%.

28. The shoe midsole according to claim 1, wherein, The elastomer component includes, selected from, ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, and C. 9-16 Copolymers of olefins in the group consisting of olefins and combinations thereof.

29. The shoe midsole according to claim 1, wherein, The elastomer component includes polymers selected from the group consisting of block copolymers, ethylene propylene diene monomer polymers, ethylene octene copolymers, ethylene butene copolymers, ethylene α-olefin copolymers, polymers of 1-butene and ethylene, polypropylene homopolymers, methacrylate-butadiene-styrene polymers, polymers having isotactic propylene units with random distribution of ethylene, styrene block copolymers, styrene-ethylene-butene-styrene copolymers, and combinations thereof.

30. The shoe midsole according to claim 1, comprising an additive selected from the group consisting of stearic acid, zinc oxide, titanium oxide, silicon oxide, and combinations thereof.

31. The shoe midsole according to claim 1, comprising one or more residues of a foaming agent, a crosslinking agent, and an addition accelerator.

32. The shoe midsole according to claim 1, wherein, It has at least 60% resilience.

33. A method for preparing a shoe midsole composed of a foamed peroxide-crosslinked polyolefin elastomer, the method comprising: Component A is formed, wherein component A comprises a mixture of a first silane-grafted polyolefin and a second silane-grafted polyolefin; The masterbatch, i.e. component B, is formed. The masterbatch contains a foaming agent, a peroxide, an additive, and an elastomer component. The elastomer component is selected from one or more elastomer polymers in the group consisting of ethylene-vinyl acetate copolymer, polyolefin elastomer, olefin block copolymer, polyoctene, anhydride-modified ethylene copolymer, ethylene-propylene-diene terpolymer, and combinations thereof. The masterbatch does not contain a condensation catalyst. Component A and component B are mixed to form a reaction mixture; and The reaction mixture is reacted under anhydrous conditions at a predetermined temperature for a predetermined time to form a foamed peroxide-crosslinked polyolefin elastomer. A first silane-grafted polyolefin is crosslinked with a second silane-grafted polyolefin and the elastomer component via C-C bonds, and the second silane-grafted polyolefin is also crosslinked with the elastomer component via C-C bonds. The foamed peroxide-crosslinked polyolefin elastomer comprises multiple closed-cell structures. The foamed peroxide-crosslinked polyolefin elastomer is formed without silane crosslinking and without water, and it does not contain condensation catalysts or their residues. The amount of ethylene-propylene-diene terpolymer is sufficient to make the melting temperature of the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, greater than 100°C.

34. The method according to claim 33, wherein, The amount of the additive and the one or more elastomeric polymers is sufficient to give the tear strength of the foamed peroxide-crosslinked polyolefin elastomer a value of 6.0 kg / cm to 13.0 kg / cm.

35. The method according to claim 34, wherein, The amount of the additive and the one or more elastomer polymers is sufficient to give the Shore C hardness of the foamed peroxide-crosslinked polyolefin elastomer a value of 35 to 45.

36. The method according to claim 35, wherein, The elastomer component includes an ethylene-propylene-diene terpolymer and / or an ethylene-vinyl acetate copolymer.

37. The method of claim 36, wherein, The elastomer component includes an olefin block copolymer.

38. The method according to claim 33, wherein, The additives include those selected from the group consisting of silicone rubber, zinc oxide, stearic acid, silane-modified amorphous polyalphaolefin, trans-polyoctene rubber (TOR), silica / silica, titanium dioxide, organic pigments, triallyl cyanurate, and combinations thereof.

39. The method according to claim 33, wherein, Foamed peroxide-crosslinked polyolefin elastomers are molded into shapes that are positioned above the outsole of a shoe.

40. The method according to claim 33, wherein, The predetermined time period is 200 to 450 seconds and the reaction temperature is 160 to 200°C.

41. The method according to claim 33, wherein, The peroxides include peroxide components selected from the group consisting of hydrogen peroxide, alkyl hydroperoxides, dialkyl peroxides, and diacyl peroxides.

42. The method according to claim 33, wherein, The peroxides include those selected from di(tert-butylperoxyisopropyl)benzene, di-tert-butyl peroxide, tert-butylisopropylbenzene peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di(tert-butyl-peroxy)hexyn-3, 1,3-bis(tert-butyl-peroxy-isopropyl)benzene, n-butyl-4,4-bis(tert-butyl-peroxy)valerate, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butylperoxyisopropyl carbonate, tert-butyl perbenzoate, bis(2-methylbenzoyl)peroxide, bis(4-methylbenzoyl)peroxide, tert-butyl peroctanoate, and hydroperoxybenzoate. Organic peroxides in the group consisting of cumene oxide, methyl ethyl ketone peroxide, lauroyl peroxide, tert-butyl peracetate, di-tert-amyl peroxide, tert-amyl peroxybenzoate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, α,α′-bis(tert-butylperoxy)-1,3-diisopropylbenzene, α,α′-bis(tert-butylperoxy)-1,4-diisopropylbenzene, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyne, and 2,4-dichlorobenzoyl peroxide.

43. The method according to claim 33, wherein, The first silane-grafted polyolefin and the second silane-grafted polyolefin are each formed independently from a silane-grafted base polyolefin.

44. The method according to claim 43, wherein, The basic polyolefin is selected from ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, C 9-16 Copolymers of olefins in the group consisting of olefins and combinations thereof.

45. The method according to claim 43, wherein, The reaction mixture is reacted in an injection molding machine.

46. ​​The method according to claim 33, wherein, The first silane-grafted polyolefin and the second silane-grafted polyolefin are each independently selected from the group consisting of silane-grafted ethylene α-olefin copolymers, silane-grafted olefin block copolymers, and combinations thereof.

47. The method according to claim 33, wherein, Component B includes ethylene vinyl acetate copolymer.

48. The method according to claim 33, wherein, Component B includes ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, and C. 9-16 Copolymers of olefins in the group consisting of olefins and combinations thereof.

49. The method according to claim 33, wherein, The elastomer component includes polymers selected from the group consisting of block copolymers, ethylene propylene diene monomer polymers, ethylene octene copolymers, ethylene butene copolymers, ethylene α-olefin copolymers, polymers of 1-butene and ethylene, polypropylene homopolymers, methacrylate-butadiene-styrene polymers, polymers having isotactic propylene units with random distribution of ethylene, styrene block copolymers, styrene-ethylene-butene-styrene copolymers, and combinations thereof.

50. A masterbatch for forming a midsole composed of a foamed peroxide-crosslinked polyolefin elastomer, the masterbatch comprising: Foaming agent; peroxide; additive; and The elastomer component, said elastomer group comprising one or more elastomer polymers selected from the group consisting of ethylene-vinyl acetate copolymers, polyolefin elastomers, olefin block copolymers, polyoctene, anhydride-modified ethylene copolymers, ethylene-propylene-diene terpolymers, and combinations thereof. The masterbatch is free of condensation catalyst and is adapted to combine with component A under ahydrous conditions to form a reaction mixture, wherein component A comprises a mixture of a first silane-grafted polyolefin, a second silane-grafted polyolefin, and optionally one or more other silane-grafted polyolefins. The reaction mixture is reacted under a moisture-free condition at a reaction temperature for a predetermined time to form a foamed peroxide-crosslinked polyolefin elastomer. This is achieved by crosslinking a first silane-grafted polyolefin with a second silane-grafted polyolefin and an elastomer component via C-C bonds, and by the second silane-grafted polyolefin with the elastomer component via C-C bonds. The foamed peroxide-crosslinked polyolefin elastomer comprises multiple closed-cell structures. The foamed peroxide-crosslinked polyolefin elastomer is formed without silane crosslinking and without water, and it is free of condensation catalysts or their residues. The amount of ethylene-propylene-diene terpolymer is sufficient to make the melting temperature of the foamed peroxide-crosslinked polyolefin elastomer, as measured by differential scanning calorimetry, greater than 100°C.

51. The masterbatch according to claim 50, wherein, The amount of the additive and one or more elastomeric polymers is sufficient to give the tear strength of the foamed peroxide-crosslinked polyolefin elastomer from 6.0 kg / cm to 13.0 kg / cm.

52. The masterbatch according to claim 51, wherein, The amount of the additive and one or more elastomer polymers is sufficient to give the Shore C hardness of the foamed peroxide-crosslinked polyolefin elastomer a value of 35 to 45.

53. The masterbatch according to claim 52, wherein, The elastomer component includes an ethylene-propylene-diene terpolymer and / or an ethylene-vinyl acetate copolymer.

54. The masterbatch according to claim 53, wherein, The elastomer component includes an olefin block copolymer.

55. The masterbatch according to claim 50, wherein, The additives include those selected from the group consisting of silicone rubber, zinc oxide, stearic acid, silane-modified amorphous polyalphaolefin, trans-polyoctene rubber (TOR), silica / silica, titanium dioxide, organic pigments, triallyl cyanurate, and combinations thereof.

56. The masterbatch according to claim 50, wherein, Foamed peroxide-crosslinked polyolefin elastomers are molded into shapes that are positioned above the outsole of a shoe.

57. The masterbatch according to claim 50, wherein, The predetermined time period is 200 to 600 seconds and the reaction temperature is 160 to 200°C.

58. The masterbatch according to claim 50, wherein, The peroxides include peroxide components selected from the group consisting of hydrogen peroxide, alkyl hydroperoxides, dialkyl peroxides, and diacyl peroxides.

59. The masterbatch according to claim 50, wherein, The peroxides include those selected from di(tert-butylperoxyisopropyl)benzene, di-tert-butyl peroxide, tert-butylisopropylbenzene peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di(tert-butyl-peroxy)hexyn-3, 1,3-bis(tert-butyl-peroxy-isopropyl)benzene, n-butyl-4,4-bis(tert-butyl-peroxy)valerate, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butylperoxyisopropyl carbonate, tert-butyl perbenzoate, bis(2-methylbenzoyl)peroxide, bis(4-methylbenzoyl)peroxide, tert-butyl peroctanoate, and hydroperoxybenzoate. Organic peroxides in the group consisting of cumene oxide, methyl ethyl ketone peroxide, lauroyl peroxide, tert-butyl peracetate, di-tert-amyl peroxide, tert-amyl peroxybenzoate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, α,α′-bis(tert-butylperoxy)-1,3-diisopropylbenzene, α,α′-bis(tert-butylperoxy)-1,4-diisopropylbenzene, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyne, and 2,4-dichlorobenzoyl peroxide.

60. The masterbatch according to claim 50, wherein, The first silane-grafted polyolefin and the second silane-grafted polyolefin of component A are each formed independently from a silane-grafted base polyolefin.

61. The masterbatch according to claim 60, wherein, The basic polyolefin is selected from ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, C 9-16 Copolymers of olefins in the group consisting of olefins and combinations thereof.

62. The masterbatch according to claim 50, wherein, The first silane-grafted polyolefin and the second silane-grafted polyolefin are each independently selected from the group consisting of silane-grafted ethylene α-olefin copolymers, silane-grafted olefin block copolymers, and combinations thereof.

63. The masterbatch according to claim 50, wherein, Component B includes ethylene vinyl acetate copolymer.

64. The masterbatch according to claim 50, wherein, Component B includes ethylene, propylene, 1-butene, 1-propylene, 1-hexene, 1-octene, and C. 9-16 Copolymers of olefins in the group consisting of olefins and combinations thereof.

65. The masterbatch according to claim 50, wherein, The elastomer component includes polymers selected from the group consisting of block copolymers, ethylene propylene diene monomer polymers, ethylene octene copolymers, ethylene butene copolymers, ethylene α-olefin copolymers, polymers of 1-butene and ethylene, polypropylene homopolymers, methacrylate-butadiene-styrene polymers, polymers having isotactic propylene units with random distribution of ethylene, styrene block copolymers, styrene-ethylene-butene-styrene copolymers, and combinations thereof.

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