Rubber modified masterbatch, preparation method thereof and preparation method of vulcanized rubber

Abstract

The invention relates to the field of rubber, and discloses a rubber modified masterbatch and a preparation method thereof, and a preparation method of vulcanized rubber, the rubber modified masterbatch comprises an ethylene-vinyl acetate copolymer, a maleic acid monomer, dicumyl peroxide, dimethylaniline and white carbon black; wherein relative to 100 parts by weight of the ethylene-vinyl acetate copolymer, the content of the maleic acid series monomer is 130 to 600 parts by weight, the content of the dicumyl peroxide is 13 to 60 parts by weight, the content of the dimethylaniline is 17 to 100 parts by weight, and the content of the white carbon black is 67 to 400 parts by weight; vulcanized rubber prepared from the rubber modified masterbatch has high strength, high wear resistance and high rebound resilience.

Description

Technical Field

[0001] This invention relates to the field of rubber, and more specifically, to a modified rubber masterbatch, a method for preparing the same, and a method for preparing vulcanized rubber. Background Technology

[0002] In today's society, the requirements for sports shoe materials for physical fitness are getting higher and higher. They must have both high elasticity and wear resistance to cope with complex and ever-changing sports environments.

[0003] In existing technologies, silica, as a primary reinforcing filler for shoe materials, imparts excellent wear resistance, slip resistance, and adhesion to the upper, and is widely used in rubber outsoles, such as in light-colored and colored outsoles (including outsoles, midsoles, and welts). However, due to the strong surface polarity of silica, its dispersion in the rubber matrix becomes exceptionally difficult, thus limiting its application. CN103980585A discloses a lightweight rubber outsole material involving natural rubber, butadiene rubber, and styrene-butadiene rubber, with silica as the main filler. It improves filler dispersibility through open mill shearing. However, this method has drawbacks: excessive milling leads to degradation of the natural rubber, and it fails to fundamentally solve the problem of interaction between silica and rubber.

[0004] CN105820383A discloses a composite material wear-resistant shoe sole, involving natural rubber, styrene-butadiene rubber, and polarized nitrile rubber, with silica as the main filler. It promotes the dispersion of silica by introducing polar rubber. The drawback of this method is that the polarity difference between the rubber matrices leads to poor matrix compatibility, failing to fundamentally solve the problem of interaction between silica and rubber.

[0005] CN112239571A discloses a rubber composition for shoe soles to improve the hardness and resilience of shoe sole materials containing silica. The composition uses a rubber matrix modifier. However, since the modifier is a polar substance, it has poor compatibility with high-viscosity rubber matrix, poor dispersibility, and inaccurate feeding, which limits its application to a certain extent.

[0006] The white shoe soles containing silica cannot simultaneously achieve the characteristics of high strength, wear resistance, and good resilience. Summary of the Invention

[0007] The purpose of this invention is to overcome the problem that white shoe soles containing silica formulations cannot simultaneously achieve strength, abrasion resistance, and resilience in the prior art. This invention provides a rubber-modified masterbatch and its preparation method, as well as a method for preparing vulcanized rubber. The vulcanized rubber obtained from this rubber-modified masterbatch can achieve high strength, high abrasion resistance, and high resilience.

[0008] To achieve the above objectives, the first aspect of the present invention provides a rubber-modified masterbatch, wherein the rubber-modified masterbatch comprises ethylene-vinyl acetate copolymer, maleic acid monomers, dicumyl peroxide, dimethylaniline, and silica.

[0009] Of which, relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the content of maleic acid monomer is 130-600 parts by weight, the content of dicumyl peroxide is 13-60 parts by weight, the content of dimethylaniline is 17-100 parts by weight, and the content of silica is 67-400 parts by weight.

[0010] A second aspect of the present invention provides a method for preparing a rubber-modified masterbatch, wherein the method includes:

[0011] (1) Plasticize the ethylene-vinyl acetate copolymer to obtain plasticized rubber;

[0012] (2) The plasticized rubber, maleic acid monomers, dicumyl peroxide, dimethylaniline and silica are mixed to obtain rubber modified masterbatch;

[0013] In this process, relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the amount of maleic acid monomer is 130-600 parts by weight, the amount of dicumyl peroxide is 13-60 parts by weight, the amount of dimethylaniline is 17-100 parts by weight, and the amount of silica is 67-400 parts by weight.

[0014] A third aspect of the present invention provides a method for preparing vulcanized rubber, wherein the method comprises: mixing the above-mentioned rubber-modified masterbatch with a base rubber and vulcanizing it to obtain vulcanized rubber;

[0015] The amount of the rubber-modified masterbatch used is 4-12 parts by weight relative to 100 parts by weight of the base rubber.

[0016] Through the above technical solutions, the rubber-modified masterbatch and its preparation method and the vulcanized rubber preparation method provided by the present invention have the following beneficial effects.

[0017] The rubber-modified masterbatch of this invention contains ethylene-vinyl acetate copolymer, maleic acid monomers, dicumyl peroxide, dimethylaniline, and silica. When each component is within a specific content range, it enables better dispersibility of additives such as silica in the base rubber, and strengthens the interaction between silica and the base rubber, resulting in vulcanized rubber with high strength, high abrasion resistance, and good resilience. Furthermore, the rubber-modified masterbatch of this invention improves the compatibility and dispersibility of maleic acid monomers in the base rubber, reduces the odor of modifiers, and is environmentally friendly, easy to weigh, and accurate in feeding, thus improving batch quality stability. Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] The first aspect of the present invention provides a rubber-modified masterbatch, wherein the rubber-modified masterbatch comprises ethylene-vinyl acetate copolymer, maleic acid monomer, dicumyl peroxide, dimethylaniline and silica;

[0020] Of which, relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the content of maleic acid monomer is 130-600 parts by weight, the content of dicumyl peroxide is 13-60 parts by weight, the content of dimethylaniline is 17-100 parts by weight, and the content of silica is 67-400 parts by weight.

[0021] In this invention, the rubber-modified masterbatch contains ethylene-vinyl acetate copolymer, maleic acid monomers, dicumyl peroxide, dimethylaniline, and silica. When each component is within a specific content range, it enables better dispersibility of additives such as silica in the base rubber, and strengthens the interaction between silica and the base rubber, resulting in a vulcanized rubber with high strength, high abrasion resistance, and good resilience. Furthermore, the rubber-modified masterbatch of this invention improves the compatibility and dispersibility of maleic acid monomers in the base rubber, reduces the odor of maleic acid monomers, and is environmentally friendly, easy to weigh, and accurate in feeding, thus improving batch quality stability.

[0022] Furthermore, relative to 100 parts by weight of the ethylene-vinyl acetate copolymer, the content of the maleic acid monomer is 150-550 parts by weight, the content of the dicumyl peroxide is 20-80 parts by weight, the content of the dimethylaniline is 15-55 parts by weight, and the content of the silica is 83-350 parts by weight.

[0023] According to the present invention, the maleic acid monomer is selected from at least one of maleic acid, maleic anhydride and dialkyl maleate.

[0024] In this invention, when the masterbatch contains the above-mentioned maleic acid monomers, the masterbatch is used to prepare vulcanizates, which has a strong modification effect on the base rubber and low side reactions, allowing additives such as silica to be better dispersed in the base rubber and improving the interaction between silica and the base rubber.

[0025] According to the present invention, the nitrogen adsorption specific surface area of ​​the silica is 140-170 m². 2 / g.

[0026] Furthermore, the nitrogen adsorption specific surface area of ​​the precipitated silica is 150-170 m². 2 / g.

[0027] According to the present invention, the average particle size of the silica is 10-20 nm.

[0028] Furthermore, the average particle size of the silica is 12-18 nm.

[0029] In this invention, when at least one of the specific surface area and average particle size of silica meets the above-mentioned range, it is beneficial to improve the interaction between silica and base rubber, and to improve the strength, wear resistance and resilience of vulcanized rubber.

[0030] According to the present invention, the vinyl acetate content in the ethylene-vinyl acetate copolymer is 30-40 wt%, preferably 35-40 wt%.

[0031] According to the present invention, the melt index of the ethylene-vinyl acetate copolymer at a temperature of 190°C and a load of 2.16 kg is 40-60 g / 10 min, preferably 50-60 g / 10 min.

[0032] According to a preferred embodiment of the present invention, relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the content of maleic acid monomer is 200-350 parts by weight, the content of dicumyl peroxide is 20-35 parts by weight, the content of dimethylaniline is 30-45 parts by weight, and the content of silica is 120-180 parts by weight.

[0033] According to a more preferred embodiment of the present invention, the content of the maleic acid monomer is 200-250 parts by weight relative to 100 parts by weight of the ethylene-vinyl acetate copolymer, the content of the dicumyl peroxide is 20-25 parts by weight, the content of the dimethylaniline is 30-35 parts by weight, and the content of the silica is 120-150 parts by weight.

[0034] A second aspect of the present invention provides a method for preparing a rubber-modified masterbatch, wherein the method includes:

[0035] (1) Plasticize the ethylene-vinyl acetate copolymer to obtain plasticized rubber;

[0036] (2) The plasticized rubber, maleic acid monomers, dicumyl peroxide, dimethylaniline and silica are mixed to obtain rubber modified masterbatch;

[0037] In this process, relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the amount of maleic acid monomer is 130-600 parts by weight, the amount of dicumyl peroxide is 13-60 parts by weight, the amount of dimethylaniline is 17-100 parts by weight, and the amount of silica is 67-400 parts by weight.

[0038] In this invention, when the amount of each component in the rubber-modified masterbatch is within a specific range, the masterbatch obtained can be used to prepare vulcanized rubber, which can make the additives such as silica have better dispersibility in the base rubber, and the interaction between silica and the base rubber is stronger, so that the vulcanized rubber has the characteristics of high strength, high wear resistance and good resilience.

[0039] Furthermore, by compounding maleic acid monomers, dicumyl peroxide, dimethylaniline, and silica with ethylene-vinyl acetate copolymer, the components can be uniformly dispersed in the ethylene-vinyl acetate copolymer. This improves the compatibility and dispersibility of maleic acid monomers, silica, and other components in the base rubber, thereby enhancing the strength, abrasion resistance, and resilience of the vulcanized rubber. Improving the compatibility of maleic acid monomers in the base rubber also reduces their odor, making it more environmentally friendly. It also facilitates masterbatch weighing, ensures accurate feeding, and enhances batch quality stability.

[0040] Furthermore, relative to 100 parts by weight of the ethylene-vinyl acetate copolymer, the amount of maleic acid monomer is 150-550 parts by weight, the amount of dicumyl peroxide is 20-80 parts by weight, the amount of dimethylaniline is 15-55 parts by weight, and the amount of silica is 83-350 parts by weight.

[0041] According to the present invention, the maleic acid monomer is selected from at least one of maleic acid, maleic anhydride and dialkyl maleate.

[0042] According to the present invention, the nitrogen adsorption specific surface area of ​​the silica is 140-170 m². 2 / g.

[0043] Furthermore, the nitrogen adsorption specific surface area of ​​the precipitated silica is 150-170 m². 2 / g.

[0044] According to the present invention, the average particle size of the silica is 10-20 nm.

[0045] Furthermore, the average particle size of the silica is 12-18 nm.

[0046] According to the present invention, the vinyl acetate content in the ethylene-vinyl acetate copolymer is 30-40 wt%, preferably 35-40 wt%.

[0047] According to the present invention, the melt index of the ethylene-vinyl acetate copolymer at a temperature of 190°C and a load of 2.16 kg is 40-60 g / 10 min, preferably 50-60 g / 10 min.

[0048] According to the present invention, the plasticizing temperature is 80-100℃, the plasticizing speed is 30-60 rpm, and the plasticizing time is 1-2 min.

[0049] According to the present invention, the mixing temperature is 80-100℃ and the mixing time is 3-6 minutes.

[0050] According to a preferred embodiment of the present invention, the method includes:

[0051] (1) Plasticize the ethylene-vinyl acetate copolymer for 1-2 minutes at 80-100℃ and 30-60 rpm to obtain plasticized rubber.

[0052] (2) Under conditions of 80-100℃, the plasticized rubber, maleic acid monomers, dicumyl peroxide, dimethylaniline and silica are mixed for 3-6 minutes to obtain rubber modified masterbatch.

[0053] Relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the content of maleic acid monomers is 200-350 parts by weight, the content of dicumyl peroxide is 20-35 parts by weight, the content of dimethylaniline is 30-45 parts by weight, and the content of silica is 120-180 parts by weight.

[0054] A third aspect of the present invention provides a method for preparing vulcanized rubber, wherein the method comprises: mixing the above-mentioned rubber-modified masterbatch with a base rubber and vulcanizing it to obtain vulcanized rubber;

[0055] The amount of the rubber-modified masterbatch used is 4-12 parts by weight relative to 100 parts by weight of the base rubber.

[0056] In this invention, the vulcanized rubber prepared by the base rubber and a specific amount of rubber-modified masterbatch has the characteristics of high strength, high wear resistance and good resilience.

[0057] Furthermore, the amount of the rubber-modified masterbatch is 5-7 parts by weight relative to 100 parts by weight of the base rubber.

[0058] In this invention, there is no particular limitation on the type of base rubber; it can be any rubber conventionally available in the art that requires vulcanization. Preferably, the base rubber is natural rubber and / or synthetic rubber. More preferably, the base rubber is butadiene rubber and / or styrene-butadiene rubber.

[0059] According to a preferred embodiment of the present invention, the base rubber is butadiene rubber and styrene-butadiene rubber. More preferably, the styrene-butadiene rubber is 5-40 parts by weight, preferably 10-20 parts by weight, relative to 100 parts by weight of the base rubber.

[0060] According to the present invention, the content of the vulcanizing agent is 2-10 parts by weight relative to 100 parts by weight of base rubber.

[0061] Furthermore, the content of the vulcanizing agent is 3-6 parts by weight relative to 100 parts by weight of the base rubber.

[0062] In this invention, there are no special limitations on the specific process conditions and operations for mixing and vulcanization; mixing and vulcanization can be carried out with reference to existing technologies in the field. To improve the overall performance of vulcanized rubber, the method for preparing vulcanized rubber includes:

[0063] (1) The rubber-modified masterbatch is first mixed with the base rubber to obtain a first-stage masterbatch;

[0064] (2) Optionally, the first stage of masterbatch is mixed with the additives in a second process to obtain a second stage of masterbatch;

[0065] (3) The first or second stage masterbatch is mixed with a vulcanizing agent in a third mixing process to obtain the final compound;

[0066] (4) The final rubber compound is vulcanized.

[0067] According to the present invention, the first mixing time is 1-5 min, and the first mixing temperature is 60-100℃.

[0068] According to the present invention, the second mixing time is 5-10 min, and the second mixing temperature is 80-160℃.

[0069] In this invention, step (2) includes standing the second compounded product at 20-25°C for 2-10 hours.

[0070] According to the present invention, the third mixing time is 3-7 minutes, and the temperature of the third mixing is less than or equal to 130°C.

[0071] In this invention, the vulcanization time is 30-40 minutes and the vulcanization temperature is 140-170°C.

[0072] According to the present invention, the additive is selected from at least one of silica, titanium dioxide, silane coupling agent, activator, softener and antioxidant.

[0073] According to a preferred embodiment of the present invention, the additives are silica, titanium dioxide, silane coupling agent, activator, softener and antioxidant.

[0074] In this invention, there is no particular limitation on the type of silica; precipitated silica that can be used for rubber reinforcement in the prior art can be used, including but not limited to: silica 200MP, 1165MP, 165GR, 115GR, etc. In this invention, the amount of silica used can be selected within a wide range. Preferably, the amount of silica used relative to 100 parts by weight of base rubber can be 40-100 parts by weight.

[0075] In this invention, there is no particular limitation on the type of titanium dioxide; any titanium dioxide that can be used as a rubber additive in the prior art can be used. Preferably, the titanium dioxide content of the titanium dioxide is greater than or equal to 90 wt%. Preferably, the amount of titanium dioxide used relative to 100 parts by weight of base rubber is 0-50 parts by weight, more preferably 20-30 parts by weight.

[0076] In this invention, there is no particular limitation on the type of silane coupling agent, and existing silane coupling agents can be used. For example, silane coupling agent Si69. Preferably, the amount of the silane coupling agent is 2-10 parts by weight relative to 100 parts by weight of the base rubber, more preferably 4-6 parts by weight.

[0077] In this invention, there is no particular limitation on the type of activator, and conventional activators in the art can be used; preferably, the activator is zinc oxide and / or stearic acid. In this invention, there is no particular limitation on the amount of activator, and the activator can be added according to the conventional amounts in the art; preferably, the amount of activator relative to 100 parts by weight of base rubber is 8-16 parts by weight, more preferably 10-14 parts by weight.

[0078] In this invention, there is no particular limitation on the type of softener, and conventional softeners in the art can be used. Preferably, the softener is selected from at least one of aromatic oils, paraffin oils, naphthenic oils, petroleum resins, and polyethylene glycol. To give the vulcanized rubber good processing performance and physical and mechanical properties, preferably, the polyethylene glycol has a weight-average molecular weight of 3000-5000 g / mol. For example, the polyethylene glycol can be polyethylene glycol PEG4000; the naphthenic oil can be, for example, ASTM103#; and the paraffin oil can be microcrystalline wax. Preferably, the amount of softener used is 5-14 parts by weight relative to 100 parts by weight of the base rubber.

[0079] In this invention, there is no particular limitation on the type of antioxidant; conventional antioxidants in the art can be used. Preferably, the antioxidant is a phenolic antioxidant. For example, the antioxidant is antioxidant 4020. Preferably, the amount of the antioxidant used is 1-4 parts by weight relative to 100 parts by weight of the base rubber.

[0080] According to the present invention, step (3) includes adding an accelerator to the first-stage masterbatch or the second-stage masterbatch.

[0081] In this invention, there is no particular limitation on the type of accelerator, and conventional accelerators in the art can be used. Preferably, the accelerator is selected from at least one of sulfenamide accelerators, thiazole accelerators, thiuram accelerators, and guanidine accelerators. Preferably, the accelerator is tetramethylthiuram disulfide (TMTD) and / or dibenzothiazole disulfide (accelerator DM). Preferably, the amount of the accelerator is 1-5 parts by weight relative to 100 parts by weight of base rubber.

[0082] In this invention, the vulcanizing agent is sulfur and / or a sulfur donor. The sulfur donor refers to a substance capable of providing sulfur. The sulfur includes at least one of insoluble sulfur, soluble sulfur, and oil-extended sulfur. For example, the vulcanizing agent is ordinary sulfur S, oil-extended insoluble sulfur IS, etc.

[0083] According to a particularly preferred embodiment of the present invention, a method for preparing vulcanized rubber includes:

[0084] (1) The rubber-modified masterbatch is first mixed with the base rubber to obtain a first-stage masterbatch;

[0085] (2) The first stage of masterbatch is mixed with silica, titanium dioxide, silane coupling agent, activator, softener and antioxidant to obtain the second stage of masterbatch;

[0086] (3) The second-stage masterbatch is mixed with the vulcanizing agent in a third mixing process to obtain the final compound;

[0087] (4) The final rubber compound is vulcanized.

[0088] The present invention will be described in detail below through embodiments.

[0089] The equipment used for preparing vulcanized rubber in the following examples and comparative examples is shown in Table 1.

[0090] The testing instruments for the vulcanized rubbers prepared in the examples and comparative examples are shown in Table 2, and the testing conditions are shown in Table 3.

[0091] In the following examples and comparative examples, the component amounts are all parts by weight, with each part by weight representing 1g.

[0092] The room temperature described in the following examples and comparative examples is 20°C.

[0093] The chemical reagents used in the examples and comparative examples are commercially available products, as detailed below:

[0094] Ethylene-vinyl acetate copolymer 1 (EVA1): EVA40W, DuPont, USA, with a vinyl acetate (VA) content of 40wt% and a melt index of 60g / 10min at 190℃ and a load of 2.16kg.

[0095] Ethylene-vinyl acetate copolymer 2 (EVA2): EVA150, DuPont, USA, with a vinyl acetate (VA) content of 30wt% and a melt index of 40g / 10min at 190℃ and a load of 2.16kg.

[0096] Ethylene-vinyl acetate copolymer 3 (EVA3): EVA150W, DuPont, USA, with a vinyl acetate (VA) content of 33wt% and a melt index of 45g / 10min at 190℃ and a load of 2.16kg.

[0097] Maleic acid monomers: maleic anhydride, maleic acid, dialkyl maleate, Aladdin Chemical Reagent Company.

[0098] Silica: Rhodia AG, France, 1165 MPa, nitrogen adsorption specific surface area 167 m² 2 / g, with an average particle size of 15.

[0099] Base rubber: Solution-polymerized styrene-butadiene rubber, Yanshan Petrochemical product, SSBR2636.

[0100] Base rubber: butadiene rubber, Yanshan Petrochemical product, BR9000.

[0101] Titanium dioxide: Weifang Hengze Chemical Co., Ltd., TiO2 content 96wt%.

[0102] Silane coupling agent: bis-[γ-(triethoxysilane)propyl]tetrasulfide (Si69), Huachen New Materials Co., Ltd.

[0103] Surfactant: Zinc oxide, Weifang Hengfeng Chemical Co., Ltd.

[0104] Surfactant: Stearic acid, Weifang Hengfeng Chemical Co., Ltd.

[0105] Softener: PEG4000, Dow Chemical Company, industrial grade.

[0106] Softener: ASTM 103# naphthenic oil, Shandong Taichang Petrochemical Technology Co., Ltd.

[0107] Softener: Microcrystalline wax, Shanghai Qiju Chemical Co., Ltd.

[0108] Antioxidant: N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine (antioxidant 4020), Ningbo Aikem New Material Co., Ltd.

[0109] Vulcanizing agent: Sulfur, Weifang Zhongheng Chemical Co., Ltd.

[0110] Accelerators: 2,2'-dithiodibenzothiazole (DM), tetramethylthiuram disulfide (TMTD), Shanghai Yongyan Chemical Technology Co., Ltd.

[0111] Table 1

[0112] Serial Number Equipment Name model Manufacturer 1 Internal mixer BR1600 Farrell Company, USA 2 Flat vulcanizing machine XLB-D400*400*2 Shanghai No.1 Rubber Machinery Factory

[0113] Table 2

[0114] Serial Number Test Project Test instrument model Manufacturer 1 hardness TH210 Yingkou City Materials Testing Machine Factory, China 2 Mechanical properties SHIMADZU AG-20KNG Multi-purpose Tensile Testing Machine Shimadzu Corporation of Japan 3 Resilience GT-7012-D Taiwan High Speed ​​Rail Corporation 4 DIN wear Zwick / Roell 5109 Zwick, Germany 5 The Penney effect RPA2000 Alpha Corporation, USA

[0115] Table 3

[0116]

[0117]

[0118] Preparation Examples 1-7 illustrate the rubber-modified masterbatch and its preparation method of the present invention.

[0119] Preparation Example 1

[0120] Set the internal mixer to 80℃ and 60rpm. Add 100 parts by weight of EVA1 (VA content 40wt%, melt index 60g / 10min) to the internal mixer and masticate for 2min. Then add 220 parts by weight of maleic anhydride, 22 parts by weight of dicumyl peroxide, 32 parts by weight of dimethylaniline, and 140 parts by weight of silica to the internal mixer and mix with the masticated rubber for 6min. Discharge to obtain rubber modified masterbatch X1.

[0121] Preparation Example 2

[0122] Set the internal mixer to 90℃ and 45rpm. Add 100 parts by weight of EVA2 (VA content 30wt%, melt index 40g / 10min) to the internal mixer and masticate for 1.5min. Then add 250 parts by weight of maleic acid, 25 parts by weight of dicumyl peroxide, 35 parts by weight of dimethylaniline, and 150 parts by weight of silica to the internal mixer and mix with the masticated rubber for 4min. Discharge to obtain rubber modified masterbatch X2.

[0123] Preparation Example 3

[0124] Set the internal mixer to 100℃ and 30rpm. Add 100 parts by weight of EVA3 (VA content 33wt%, melt index 45g / 10min) to the internal mixer and masticate for 1min. Then add 300 parts by weight of dialkyl maleate, 30 parts by weight of dicumyl peroxide, 40 parts by weight of dimethylaniline, and 167 parts by weight of silica to the internal mixer and mix with the masticated rubber for 3min. The resulting material is rubber modified masterbatch X3.

[0125] Preparation Example 4

[0126] Set the internal mixer to 80℃ and 60rpm. Add 100 parts by weight of EVA1 (VA content 40wt%, melt index 60g / 10min) to the internal mixer and masticate for 2min. Then add 600 parts by weight of maleic anhydride, 60 parts by weight of dicumyl peroxide, 100 parts by weight of dimethylaniline, and 400 parts by weight of silica to the internal mixer and mix with the masticated rubber for 6min. Discharge to obtain rubber modified masterbatch X4.

[0127] Preparation Example 5

[0128] Set the internal mixer to 80℃ and 60rpm. Add 100 parts by weight of EVA1 (VA content 40wt%, melt index 60g / 10min) to the internal mixer and masticate for 2min. Then add 140 parts by weight of maleic anhydride, 10 parts by weight of dicumyl peroxide, 15 parts by weight of dimethylaniline, and 50 parts by weight of silica to the internal mixer and mix with the masticated rubber for 6min. Discharge to obtain rubber modified masterbatch X5.

[0129] Preparation Example 6

[0130] In this preparation example, no dimethylaniline was added. Specifically, the internal mixer was set to 80°C and 60 rpm. 100 parts by weight of EVA1 (VA content 40 wt%, melt index 60 g / 10 min) was added to the internal mixer and masticated for 2 min. Then, 220 parts by weight of maleic anhydride, 22 parts by weight of dicumyl peroxide, and 140 parts by weight of silica were added to the internal mixer and mixed with the masticated rubber for 6 min. The rubber modified masterbatch X6 was obtained by discharging the material.

[0131] Preparation Example 7

[0132] Set the internal mixer to 80℃ and 60rpm. Add 100 parts by weight of EVA1 (VA content 40wt%, melt index 60g / 10min) to the internal mixer and masticate for 2min. Then add 220 parts by weight of maleic anhydride, 22 parts by weight of benzoyl peroxide, 32 parts by weight of N,N-dimethylformamide, and 140 parts by weight of silica to the internal mixer and mix with the masticated rubber for 6min. The resulting material is rubber modified masterbatch X7.

[0133] Examples 1-8 illustrate the preparation method of vulcanized rubber provided by the present invention.

[0134] Example 1

[0135] Vulcanized rubber formulation: 10 parts by weight of solution-polymerized styrene-butadiene rubber (base rubber), 90 parts by weight of butadiene rubber (base rubber), 5 parts by weight of rubber-modified masterbatch X1, 60 parts by weight of silica, 25 parts by weight of titanium dioxide, 5 parts by weight of Si69 (silane coupling agent), 6 parts by weight of zinc oxide (activator), 4 parts by weight of stearic acid (activator), 3 parts by weight of PEG4000 (softener), 5 parts by weight of naphthenic oil (softener), 5 parts by weight of microcrystalline wax (softener), 1 part by weight of antioxidant 4020, 3 parts by weight of sulfur (vulcanizing agent), 3 parts by weight of DM (accelerator), 2.5 parts by weight of TMTD (accelerator).

[0136] Preparation of vulcanized rubber:

[0137] (1) Add the base rubber and 5 parts by weight of rubber modified masterbatch X1 into a mixer and mix at 70°C for 3 minutes to obtain a masterbatch.

[0138] (2) Add silica, titanium dioxide, activator, softener and antioxidant to the first stage of masterbatch, mix in an internal mixer for 7 minutes, and after mixing, the second stage of masterbatch is obtained and placed at room temperature for 5 hours.

[0139] (3) Add vulcanizing agent and accelerator to the second stage masterbatch, mix at 60°C for 5 minutes to obtain final rubber, and then perform flat vulcanization on the obtained final rubber at a vulcanization temperature of 160°C, a vulcanization pressure of 15MPa and a vulcanization time of 35min to obtain vulcanized rubber sample S1.

[0140] The performance of vulcanized rubber sample S1 was tested, and the results are shown in Table 4.

[0141] Example 2

[0142] Vulcanized rubber formulation: 10 parts by weight of solution-polymerized styrene-butadiene rubber (base rubber), 90 parts by weight of butadiene rubber (base rubber), 6 parts by weight of rubber-modified masterbatch X1, 60 parts by weight of silica, 25 parts by weight of titanium dioxide, 5 parts by weight of Si69 (silane coupling agent), 6 parts by weight of zinc oxide (activator), 4 parts by weight of stearic acid (activator), 3 parts by weight of PEG4000 (softener), 5 parts by weight of naphthenic oil (softener), 5 parts by weight of microcrystalline wax (softener), 1 part by weight of antioxidant 4020, 3 parts by weight of sulfur (vulcanizing agent), 3 parts by weight of DM (accelerator), 2.5 parts by weight of TMTD (accelerator).

[0143] The vulcanized rubber preparation process is the same as that in Example 1, and vulcanized rubber sample S2 is obtained.

[0144] The performance of vulcanized rubber sample S2 was tested, and the results are shown in Table 4.

[0145] Example 3

[0146] Vulcanized rubber formulation: 10 parts by weight of solution-polymerized styrene-butadiene rubber (base rubber), 90 parts by weight of butadiene rubber (base rubber), 7 parts by weight of rubber-modified masterbatch X1, 60 parts by weight of silica, 25 parts by weight of titanium dioxide, 5 parts by weight of Si69 (silane coupling agent), 6 parts by weight of zinc oxide (activator), 4 parts by weight of stearic acid (activator), 3 parts by weight of PEG4000 (softener), 5 parts by weight of naphthenic oil (softener), 5 parts by weight of microcrystalline wax (softener), 1 part by weight of antioxidant 4020, 3 parts by weight of sulfur (vulcanizing agent), 3 parts by weight of DM (accelerator), 2.5 parts by weight of TMTD (accelerator).

[0147] The vulcanized rubber preparation process is the same as that in Example 1, and vulcanized rubber sample S3 is obtained.

[0148] The performance of vulcanized rubber sample S3 was tested, and the results are shown in Table 4.

[0149] Example 4

[0150] Vulcanized rubber formulation: 10 parts by weight of solution-polymerized styrene-butadiene rubber (base rubber), 90 parts by weight of cis-butadiene rubber (base rubber), 12 parts by weight of rubber-modified masterbatch X1, 60 parts by weight of silica, 25 parts by weight of titanium dioxide, 5 parts by weight of Si69 (silane coupling agent), 6 parts by weight of zinc oxide (activator), 4 parts by weight of stearic acid (activator), 3 parts by weight of PEG4000 (softener), 5 parts by weight of naphthenic oil (softener), 5 parts by weight of microcrystalline wax (softener), 1 part by weight of antioxidant 4020, 3 parts by weight of sulfur (vulcanizing agent), 3 parts by weight of DM (accelerator), 2.5 parts by weight of TMTD (accelerator).

[0151] The vulcanized rubber preparation process is the same as that in Example 1, and vulcanized rubber sample S4 is obtained.

[0152] The performance of vulcanized rubber sample S4 was tested, and the results are shown in Table 4.

[0153] Example 5

[0154] Rubber was processed according to the method of Example 1, except that 5 parts by weight of rubber processing modified masterbatch X1 was replaced by 5 parts by weight of rubber processing modified masterbatch X2.

[0155] The vulcanized rubber preparation process is the same as that in Example 1, and vulcanized rubber sample S5 is obtained.

[0156] The performance of vulcanized rubber sample S5 was tested, and the results are shown in Table 4.

[0157] Example 6

[0158] Rubber was processed according to the method of Example 1, except that 5 parts by weight of rubber processing modified masterbatch X1 was replaced by 5 parts by weight of rubber processing modified masterbatch X3.

[0159] The vulcanized rubber preparation process is the same as that in Example 1, and vulcanized rubber sample S6 is obtained.

[0160] The performance of vulcanized rubber sample S6 was tested, and the results are shown in Table 4.

[0161] Example 7

[0162] Rubber was processed according to the method of Example 1, except that 5 parts by weight of rubber processing modified masterbatch X1 was replaced by 5 parts by weight of rubber processing modified masterbatch X4.

[0163] The vulcanized rubber preparation process is the same as that in Example 1, and vulcanized rubber sample S7 is obtained.

[0164] The performance of vulcanized rubber sample S7 was tested, and the results are shown in Table 4.

[0165] Example 8

[0166] Rubber was processed according to the method of Example 1, except that rubber modification masterbatch X1 was not used. Instead, maleic acid monomers, dicumyl peroxide, dimethylaniline, EVA1, and silica were added in the same proportions to replace rubber modification masterbatch X1. After vulcanization, vulcanized rubber S8 was obtained.

[0167] The performance of vulcanized rubber sample S8 was tested, and the results are shown in Table 4.

[0168] Comparative Example 1

[0169] Rubber was processed according to the method of Example 1, except that the amount of rubber modified masterbatch X1 added was 3 parts by weight, and vulcanized rubber sample DS1 was obtained.

[0170] The performance of vulcanized rubber sample DS1 was tested, and the results are shown in Table 4.

[0171] Comparative Example 2

[0172] Rubber was prepared according to the method of Example 1, except that the amount of rubber-modified masterbatch added was 6 parts by weight X5, and vulcanized rubber sample DS2 was obtained.

[0173] The performance of vulcanized rubber sample DS2 was tested, and the results are shown in Table 4.

[0174] Comparative Example 3

[0175] Rubber is processed according to the method of Example 1, except that no rubber-modifying masterbatch is added during the rubber processing, and vulcanized rubber DS4 is obtained after vulcanization.

[0176] The performance of the vulcanized rubber sample DS4 was tested, and the results are shown in Table 4.

[0177] Comparative Example 4

[0178] Rubber was processed according to the method of Example 1, except that 5 parts by weight of rubber processing modified masterbatch X1 was replaced by 5 parts by weight of rubber processing modified masterbatch X6 to obtain vulcanized rubber sample DS4.

[0179] The performance of the vulcanized rubber sample DS4 was tested, and the results are shown in Table 4.

[0180] Comparative Example 5

[0181] Rubber was processed according to the method of Example 1, except that 5 parts by weight of rubber processing modified masterbatch X1 was replaced by 5 parts by weight of rubber processing modified masterbatch X7 to obtain vulcanized rubber sample DS5.

[0182] The performance of the vulcanized rubber sample DS5 was tested, and the results are shown in Table 4.

[0183] Table 4

[0184] Sample number S1 S2 S3 S4 S5 S6 S7 G'0.7% / kPa 110 112 109 115 108 110 113 G'100% / kPa 32.0 31.9 31.5 32.1 30.8 31.4 31.8 G'0.7%-G'100% / kPa 78.0 80.1 77.5 82.9 77.2 78.6 81.2 Hardness (°) 78 76 77 79 76 75 79 Tensile strength (MPa) 16.2 16.3 16.0 15.2 16.2 16.5 15.1 Tear strength (kN / m) 45 44 46 41 43 46 40 <![CDATA[DIN wear (mm 3 )]]> 60 59 58 65 59 59 68 Rebound value (%) 35.5 35.0 36.2 33.2 35.8 35.7 34

[0185] Continued from Table 4

[0186] Sample number S8 DS1 DS2 DS3 DS4 DS5 G'0.7% / kPa 123 120 142 129 158 168 G'100% / kPa 32.4 32.0 34.9 32.5 36.4 37.0 G'0.7%-G'100% / kPa 90.6 88.0 107.1 96.5 121.6 131.0 Hardness (°) 80 83 85 83 89 90 Tensile strength (MPa) 14.3 13.0 11.9 12.0 10.2 9.8 Tear strength (kN / m) 36 32 28 31 29 25 <![CDATA[DIN wear (mm 3 )]]> 75 86 94 91 110 121 Rebound value (%) 30.1 26.3 25.8 27.5 23.4 21.7

[0187] The results above show that using the rubber-modified masterbatch provided by this invention results in better dispersion of silica in the rubber matrix and stronger interaction between silica and the rubber matrix, thereby enabling the vulcanized rubber to have excellent comprehensive properties such as high strength, high wear resistance, and good resilience.

[0188] Furthermore, comparing Example 1 and Example 8, it can be seen that when ethylene-vinyl acetate copolymer, maleic acid monomers, dicumyl peroxide, dimethylaniline and silica are made into a masterbatch and then added to the base rubber, the vulcanized rubber prepared has higher strength, wear resistance and resilience.

[0189] Since the rubber modification masterbatch and preparation method provided by the present invention can give the obtained vulcanized rubber better performance, the vulcanized rubber of the present invention can improve the durability and comfort of the shoe material when applied to shoe materials.

[0190] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A rubber-modified masterbatch, characterized in that, The rubber-modified masterbatch includes ethylene-vinyl acetate copolymer, maleic acid monomers, dicumyl peroxide, dimethylaniline, and silica. Of which, relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the content of maleic acid monomer is 130-600 parts by weight, the content of dicumyl peroxide is 13-60 parts by weight, the content of dimethylaniline is 17-100 parts by weight, and the content of silica is 67-400 parts by weight.

2. The rubber-modified masterbatch according to claim 1, wherein, Relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the content of maleic acid monomers is 150-550 parts by weight, the content of dicumyl peroxide is 20-80 parts by weight, the content of dimethylaniline is 15-55 parts by weight, and the content of silica is 83-350 parts by weight.

3. The rubber-modified masterbatch according to claim 1 or 2, wherein, The maleic acid monomer is selected from at least one of maleic acid, maleic anhydride and dialkyl maleate; Preferably, the nitrogen adsorption specific surface area of ​​the silica is 140-170 m². 2 / g; Preferably, the average particle size of the silica is 10-20 nm.

4. The rubber-modified masterbatch according to any one of claims 1-3, wherein, The vinyl acetate content in the ethylene-vinyl acetate copolymer is 30-40 wt%. Preferably, the ethylene-vinyl acetate copolymer has a melt index of 40-60 g / 10 min at a temperature of 190°C and a load of 2.16 kg.

5. A method for preparing a rubber-modified masterbatch, characterized in that, The method includes: (1) Plasticize the ethylene-vinyl acetate copolymer to obtain plasticized rubber; (2) The plasticized rubber, maleic acid monomers, dicumyl peroxide, dimethylaniline and silica are mixed to obtain rubber modified masterbatch; In this process, relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the amount of maleic acid monomer is 130-600 parts by weight, the amount of dicumyl peroxide is 13-60 parts by weight, the amount of dimethylaniline is 17-100 parts by weight, and the amount of silica is 67-400 parts by weight.

6. The preparation method according to claim 5, wherein, Relative to 100 parts by weight of ethylene-vinyl acetate copolymer, the amount of maleic acid monomer is 150-550 parts by weight, the amount of dicumyl peroxide is 20-80 parts by weight, the amount of dimethylaniline is 15-55 parts by weight, and the amount of silica is 83-350 parts by weight. Preferably, the maleic acid monomer is selected from at least one of maleic acid, maleic anhydride, and dialkyl maleate; Preferably, the nitrogen adsorption specific surface area of ​​the silica is 140-170 m². 2 / g; Preferably, the average particle size of the silica is 10-20 nm; Preferably, the vinyl acetate content in the ethylene-vinyl acetate copolymer is 30-40 wt%. Preferably, the ethylene-vinyl acetate copolymer has a melt index of 40-60 g / 10 min at a temperature of 190°C and a load of 2.16 kg.

7. The preparation method according to claim 5 or 6, wherein, The plasticizing temperature is 80-100℃, the plasticizing speed is 30-60 rpm, and the plasticizing time is 1-2 min; Preferably, the mixing temperature is 80-100℃ and the mixing time is 3-6 minutes.

8. A method for preparing vulcanized rubber, characterized in that, The method includes: mixing and vulcanizing the rubber-modified masterbatch described in any one of claims 1-4 with a base rubber to obtain vulcanized rubber; The amount of the rubber-modified masterbatch used is 4-12 parts by weight relative to 100 parts by weight of the base rubber.

9. The method according to claim 8, wherein, The amount of the rubber-modified masterbatch is 5-7 parts by weight relative to 100 parts by weight of the base rubber. Preferably, the base rubber is natural rubber and / or synthetic rubber.

10. The method according to claim 8 or 9, wherein, The method includes: (1) The rubber-modified masterbatch is first mixed with the base rubber to obtain a first-stage masterbatch; (2) Optionally, the first stage of masterbatch is mixed with the additives in a second process to obtain a second stage of masterbatch; (3) The first or second stage masterbatch is mixed with a vulcanizing agent in a third mixing process to obtain the final compound; (4) The final rubber compound is vulcanized.

11. The method according to claim 10, wherein, The content of the vulcanizing agent relative to 100 parts by weight of base rubber is 2-10 parts by weight, preferably 4-6 parts by weight; Preferably, the additive is selected from at least one of silica, titanium dioxide, silane coupling agent, activator, softener and antioxidant; Preferably, step (3) includes: adding an accelerator to the first-stage masterbatch or the second-stage masterbatch; Preferably, the first mixing time is 1-5 minutes, and the first mixing temperature is 60-100℃; Preferably, the second mixing time is 5-10 minutes, and the second mixing temperature is 80-160℃; Preferably, the third mixing time is 3-7 minutes, and the temperature of the third mixing is less than or equal to 130°C.

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