Rubber processing aids, methods of making and using same, rubber compositions and uses, vulcanized rubber and methods of making and using same

Abstract

The application relates to the rubber field and discloses a rubber processing aid, a preparation method and application thereof, a rubber composition and application, vulcanized rubber and a preparation method and application thereof. The rubber processing aid comprises a mercapto acid monomer, solution polymerized styrene-butadiene rubber and white carbon black; the content of the mercapto acid monomer is 60-200 parts by weight, and the content of the white carbon black is 20-66.7 parts by weight, relative to 100 parts by weight of the solution polymerized styrene-butadiene rubber. The rubber processing aid comprises the mercapto acid monomer, the solution polymerized styrene-butadiene rubber and the white carbon black, the mercapto acid monomer is mixed with the solution polymerized styrene-butadiene rubber and the white carbon black in advance to prepare the rubber processing aid, the compatibility and dispersibility of the mercapto acid monomer and the rubber matrix can be obviously improved, and then the strength, wear resistance and wet skid resistance of the vulcanized rubber can be obviously improved under the premise of ensuring that the vulcanized rubber has low heat generation.

Description

Technical Field

[0001] This invention relates to the field of rubber, specifically to a rubber processing aid and its preparation method and application, rubber compositions and their applications, and vulcanized rubber and its preparation method and application. Background Technology

[0002] In recent years, the dynamic hysteresis loss performance of green tires has determined the tire classification and grading, which can also lead to a decrease in the strength and wear resistance of rubber, causing premature tire damage, increasing tire rolling resistance, fuel consumption and carbon dioxide emissions.

[0003] CN102382338A discloses an isoprene rubber blend comprising isoprene rubber, trans-1,4-polyisoprene, reinforcing filler, in-situ grafting modifier, compounded rubber, and a first additive. The in-situ grafting modifier used in this prior art reacts chemically with the reinforcing filler and simultaneously grafts onto functional groups such as double bonds on the rubber molecular chain. This significantly improves the interfacial bonding force between the organic polymer and the reinforcing filler, as well as the dispersion level of the reinforcing filler in the rubber, thereby enhancing the fatigue resistance of the isoprene rubber blend.

[0004] CN103881161A discloses a trans-polyisoprene rubber combined with a cis-polyisoprene rubber composition and its processing technology. Specifically, it discloses that, based on 100 parts by weight of rubber, the total amount of synthetic trans-polyisoprene and synthetic cis-polyisoprene is 5-60 parts by weight, natural rubber is 40-95 parts by weight, precipitated silica is 5-90 parts by weight, and carbon black is 5-90 parts by weight. The masterbatch process includes: mixing synthetic trans-polyisoprene or a composition of synthetic trans-polyisoprene and synthetic cis-polyisoprene rubber with precipitated silica and a coupling agent to form precipitated silica wood glue; mixing natural rubber with carbon black to form carbon black masterbatch; and the final compounding process involves mixing the carbon black masterbatch, precipitated silica wood glue, antioxidant, activator, accelerator, and vulcanizing agent to form a rubber composition. The rubber composition and process of this prior art produce rubber compounds with improved wear resistance and reduced heat generation. These compounds can be applied to rubber products, especially automobile tires, to reduce rolling resistance and heat generation.

[0005] CN103703072A discloses a rubber composition for tire treads, comprising solution-polymerized styrene-butadiene rubber (SBR), carbon black, silica, and polyethylene glycol (PEG). The SBR content is 60% or more per 100% by mass of the rubber composition. Relative to 100 parts by mass of the rubber composition, the carbon black content is less than 10 parts by mass, the silica content is 50 parts by mass or more, and the PEG content is 0.1-3.5 parts by mass. According to this prior art, a rubber composition containing SBR, carbon black, silica, and PEG in specified amounts, when applied to tire treads, can provide a pneumatic tire with balanced improvements in fuel economy and wear resistance. Furthermore, the vulcanization speed is good during tire manufacturing, and the manufactured tire has a good appearance.

[0006] CN103087365A discloses a rubber composition for a tire tread with balanced wet grip and wear resistance. This rubber composition comprises a diene elastomer, inorganic reinforcing filler, coupling agent, and plasticizer. In this prior art, when a tire containing this rubber composition is used, the tire tread exhibits excellent wet grip, providing a balance between wet grip and wear resistance. This tread is used in the manufacture of semi-steel radial passenger car tires.

[0007] However, the rubber provided by the above-mentioned prior art still cannot meet the requirements of tire tread rubber for strength, reduced heat generation, and improved wet grip performance, so it is necessary to provide a rubber with improved performance.

[0008] CN107964138A discloses the application of mercapto acid monomers and their application in tire treads. This prior art involves mixing mercapto acid monomers with a rubber matrix, which can better leverage the bridging role of the mercapto acid monomer as a matrix modifier between the matrix rubber and silica. This facilitates the full interaction between silica and the rubber matrix, improving the strength of the vulcanized rubber obtained through further vulcanization, reducing the heat generation of the vulcanized rubber, and enhancing the wet skid resistance of the vulcanized rubber compound. However, the application of mercapto acid monomers is limited by drawbacks such as odor, poor compatibility with high-viscosity rubber matrices, poor dispersibility, and inaccurate dosage. Summary of the Invention

[0009] The purpose of this invention is to overcome the poor compatibility and dispersibility of mercapto acid monomers in high-viscosity rubber matrices in existing technologies. During in-situ modification with mercapto acid monomers, the high local concentration of mercapto acid monomers in the matrix leads to high gel content, which in turn affects the strength, wear resistance, wet skid resistance, and heat generation of the vulcanized rubber. This invention provides a rubber processing aid, its preparation method and application, a rubber composition and application, and a vulcanized rubber, its preparation method and application. The rubber processing aid comprises mercapto acid monomers, solution-polymerized styrene-butadiene rubber (SBR), and silica. The rubber processing aid is prepared by pre-mixing the mercapto acid monomers with SBR and silica, which significantly improves the compatibility and dispersibility of the mercapto acid monomers with the rubber matrix. This results in a significant improvement in the strength, wear resistance, and wet skid resistance of the vulcanized rubber while maintaining low heat generation.

[0010] To achieve the above objectives, the first aspect of the present invention provides a rubber processing aid, characterized in that the rubber processing aid comprises a mercapto acid monomer, solution-polymerized styrene-butadiene rubber, and silica;

[0011] The content of the mercapto acid monomer is 60-200 parts by weight relative to 100 parts by weight of solution-polymerized styrene-butadiene rubber, and the content of the silica is 20-66.7 parts by weight.

[0012] A second aspect of the present invention provides a method for preparing a rubber processing aid, characterized in that the preparation method includes the following steps:

[0013] (1) Stir the silica and mercapto acid monomers until they are evenly mixed to obtain a preloaded mixture;

[0014] (2) The solution-polymerized styrene-butadiene rubber is plasticized to obtain plasticized rubber;

[0015] (3) The preloaded mixture is mixed with the plasticized rubber to obtain the rubber processing aid;

[0016] The content of the mercapto acid monomer is 60-200 parts by weight relative to 100 parts by weight of solution-polymerized styrene-butadiene rubber, and the content of the silica is 20-66.7 parts by weight.

[0017] A third aspect of the present invention provides a rubber processing aid prepared by the above-described preparation method.

[0018] The fourth aspect of the present invention provides the application of the above-mentioned rubber processing aid in the preparation of vulcanized rubber.

[0019] A fifth aspect of the present invention provides a rubber composition, characterized in that the rubber composition comprises the above-mentioned rubber processing aid and a base rubber;

[0020] The amount of the rubber processing aid is 0.2-4 parts by weight, preferably 0.5-2 parts by weight, relative to 100 parts by weight of the base rubber.

[0021] The sixth aspect of this invention provides a method for preparing vulcanized rubber, characterized in that the preparation method includes:

[0022] The components of a rubber composition containing rubber processing aids and base rubber are mixed to obtain a mixed rubber preform, and the mixed rubber preform is vulcanized to obtain the vulcanized rubber.

[0023] The rubber processing aid is the aforementioned rubber processing aid.

[0024] A seventh aspect of the present invention provides a vulcanized rubber prepared by the above-described preparation method.

[0025] The eighth aspect of the present invention provides the use of the above-described rubber composition or vulcanized rubber in tire tread.

[0026] Through the above technical solutions, the rubber processing aids and their preparation methods and applications, rubber compositions and their applications, and vulcanized rubbers and their preparation methods and applications provided by the present invention achieve the following beneficial effects:

[0027] The rubber processing aid provided by this invention comprises mercapto acid monomers, solution-polymerized styrene-butadiene rubber (SBR), and silica. The mercapto acid monomers are pre-mixed with the matrix material and silica to prepare the rubber processing aid, which significantly improves the compatibility and dispersibility between the mercapto acid monomers and the rubber matrix. This results in a significant increase in the strength, abrasion resistance, and wet skid resistance of the vulcanized rubber while maintaining low heat generation. When this vulcanized rubber is used in tire treads, it significantly improves tire durability and vehicle safety. Detailed Implementation

[0028] 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.

[0029] The first aspect of the present invention provides a rubber processing aid, characterized in that the rubber processing aid comprises a mercapto acid monomer, solution-polymerized styrene-butadiene rubber, and silica;

[0030] The content of the mercapto acid monomer is 60-200 parts by weight relative to 100 parts by weight of solution-polymerized styrene-butadiene rubber, and the content of the silica is 20-66.7 parts by weight.

[0031] The rubber processing aid provided by this invention comprises mercapto acid monomers, solution-polymerized styrene-butadiene rubber (SBR), and silica. The mercapto acid monomers are pre-mixed with the matrix material and silica to prepare the rubber processing aid, which significantly improves the compatibility and dispersibility between the mercapto acid monomers and the rubber matrix. This results in a significant increase in the strength, abrasion resistance, and wet skid resistance of the vulcanized rubber while maintaining low heat generation. When this vulcanized rubber is used in tire treads, it significantly improves the durability and safety of automobiles.

[0032] Furthermore, by combining mercapto acid monomers with the rubber matrix through the rubber processing aid provided by this invention, the irritating odor generated by mercapto acid monomers is reduced, which is environmentally friendly. More importantly, it is convenient to weigh, accurate in feeding, and improves batch quality stability.

[0033] Furthermore, when the amounts of mercapto acid monomers, solution-polymerized styrene-butadiene rubber, and silica meet the above-mentioned ranges, the loading of the modifier mercapto acid monomers can be increased, the irritating odor generated when adding mercapto acid monomers in situ can be reduced, the weighing process is convenient and accurate, and the dispersibility of rubber processing aids in the rubber matrix can be significantly improved.

[0034] According to the present invention, the content of the mercapto acid monomer is 89-143 parts by weight relative to 100 parts by weight of solution-polymerized styrene-butadiene rubber, and the content of the silica is 27-46 parts by weight.

[0035] According to the present invention, the mercapto acid monomer is provided by at least one of the compounds represented by formula (1):

[0036]

[0037] Where x is 0 and R2 is -SH; or,

[0038] x is 1, M is the structure shown in equation (2), R1 and R2 are each independently H or -SH, and R1 and R2 are not simultaneously H; or,

[0039] x is 2, M is the structure shown in equation (2), R2 and R1 in the two M are each independently H or -SH, and R2 and R1 in the two M are not simultaneously H; or,

[0040] x is 3, M is the structure shown in equation (2), R2 and R1 in the three M are each independently H or -SH, and R2 and R1 in the three M are not simultaneously H.

[0041] In this invention, the compound shown in formula (1) is selected as the mercapto acid monomer, and the rubber processing aid containing the mercapto acid monomer is added to the rubber matrix. This can significantly improve the dispersibility and compatibility between the matrix rubber, silica and mercapto acid monomer. In this way, the strength, wear resistance and wet skid resistance of the vulcanized rubber can be significantly improved while ensuring that the vulcanized rubber has low heat generation. It is suitable as a tire tread compound.

[0042] In one specific embodiment of the present invention, the mercapto acid monomer is 3-mercaptoacrylic acid and / or 4-mercaptobutyric acid.

[0043] According to the present invention, the styrene-butadiene rubber contains 10-30 wt% styrene structural units and 40-70 wt% vinyl groups.

[0044] Furthermore, in the solution-polymerized styrene-butadiene rubber, the styrene structural unit content is 20-25 wt%, and the vinyl content is 55-65 wt%.

[0045] According to the present invention, the Mooney viscosity (100°C, 1+4 min) of the solution-polymerized styrene-butadiene rubber is 55-75, preferably 60-65.

[0046] In this invention, there is no particular limitation on the type of silica, which can be any conventional type of silica in the art, such as fumed silica and / or precipitated silica. Preferably, the silica is precipitated silica.

[0047] A second aspect of the present invention provides a method for preparing a rubber processing aid, characterized in that the preparation method includes the following steps:

[0048] (1) Stir the silica and mercapto acid monomers until they are evenly mixed to obtain a preloaded mixture;

[0049] (2) The solution-polymerized styrene-butadiene rubber is plasticized to obtain plasticized rubber;

[0050] (3) The preloaded mixture is mixed with the plasticized rubber to obtain the rubber processing aid;

[0051] The content of the mercapto acid monomer is 60-200 parts by weight relative to 100 parts by weight of solution-polymerized styrene-butadiene rubber, and the content of the silica is 20-66.7 parts by weight.

[0052] In this invention, by using the above method, silica and mercapto acid monomers are mixed and then compounded with solution-polymerized styrene-butadiene rubber to obtain the rubber processing aid described in the first aspect of this invention. This allows the mercapto acid monomers to be fully and uniformly mixed with silica and matrix materials beforehand, thereby significantly improving the compatibility and dispersibility of the mercapto acid monomers with the rubber matrix. When this rubber processing aid is used to prepare vulcanized rubber, the strength, wear resistance, and wet skid resistance of the vulcanized rubber can be significantly improved while ensuring that the vulcanized rubber has low heat generation.

[0053] The amount and type of raw materials used in the preparation of rubber processing aids in the second aspect of this invention are exactly the same as those used in the first aspect of this invention. To avoid repetition, the second aspect of this invention will not repeat the details, and those skilled in the art should not understand it as a limitation of this invention.

[0054] In this invention, there are no particular limitations on the mixing method of silica and mercapto acid monomers, as long as silica and mercapto acid monomers can form a uniform preloaded mixture.

[0055] According to the present invention, the plasticizing conditions include: a plasticizing temperature of 20-40°C, a rotation speed of 30-60 rpm, and a plasticizing time of 1-2 min.

[0056] In this invention, under the above conditions, the solution-polymerized styrene-butadiene rubber is plasticized, which can improve the processing performance of the solution-polymerized styrene-butadiene rubber and make the solution-polymerized styrene-butadiene rubber, mercapto acid monomers and silica uniformly mixed, thereby further improving the compatibility and dispersibility among mercapto acid monomers, matrix materials and silica in rubber processing aids.

[0057] In this invention, the plasticizing can be carried out in conventional equipment in the art, preferably a Banbury mixer.

[0058] According to the present invention, the mixing conditions include: a mixing time of 3-6 minutes and a mixing temperature of 60-90°C.

[0059] In this invention, under the above conditions, the plasticized rubber and the preloaded mixture are mixed to ensure that the plasticized rubber and the preloaded mixture are fully and uniformly mixed, resulting in a rubber processing aid with excellent dispersibility and compatibility among its components. When this rubber processing aid is used to prepare vulcanized rubber, the dispersibility and compatibility of the rubber processing aid in the rubber matrix are significantly improved.

[0060] Furthermore, the mixing conditions include: a mixing time of 3-6 minutes and a mixing temperature of 60-70°C.

[0061] In this invention, the mixing can be carried out in conventional equipment in the art, preferably a Banbury mixer.

[0062] A third aspect of the present invention provides a rubber processing aid prepared by the above-described preparation method.

[0063] The fourth aspect of the present invention provides the application of the above-mentioned rubber processing aid in the preparation of vulcanized rubber.

[0064] A fifth aspect of the present invention provides a rubber composition, characterized in that the rubber composition comprises the above-mentioned rubber processing aid and a base rubber;

[0065] The amount of the rubber processing aid is 0.2-4 parts by weight relative to 100 parts by weight of base rubber.

[0066] Furthermore, the amount of the rubber processing aid is 0.5-2 parts by weight relative to 100 parts by weight of the base rubber.

[0067] In this invention, the base rubber can be any type of rubber that requires vulcanization processing, including but not limited to: natural rubber and / or synthetic rubber, wherein the synthetic rubber can include but not limited to: butadiene rubber and / or styrene-butadiene rubber.

[0068] In this invention, the rubber composition also includes conventional additives in the art, such as silica, carbon black, activators, antioxidants, vulcanizing agents, and accelerators.

[0069] In this invention, the silica can be any existing precipitated silica that can be used for rubber reinforcement, including but not limited to: silica 200MP, 1165MP, 165GR, 115GR, and the content of silica can be selected within a wide range; specifically, relative to 100 parts by weight of base rubber, the content of silica can be 40-100 parts by weight.

[0070] In this invention, the carbon black can be any existing carbon black that can be used as a rubber additive, including but not limited to: carbon black N550, N774 and N330, and the content of the carbon black can be selected in a wide range; specifically, the content of the carbon black relative to 100 parts by weight of base rubber can be 0-70 parts by weight.

[0071] In this invention, the type and amount of the activator are well known to those skilled in the art. The activator may be zinc oxide and / or stearic acid. Specifically, the content of the activator may be 2-10 parts by weight relative to 100 parts by weight of natural rubber and synthetic rubber.

[0072] In this invention, the softener is at least one selected from aromatic oil, paraffin oil, naphthenic oil, petroleum resin, and polyethylene glycol. The polyethylene glycol has a weight-average molecular weight of 3000-5000, which gives the composite material good processability and physical and mechanical properties. The aromatic oil can be, for example, TDAE V500, and the polyethylene glycol can be, for example, PEG4000. Specifically, the content of the softener relative to 100 parts by weight of the base rubber can be 5-15 parts by weight.

[0073] In this invention, the antioxidant is at least one selected from amine antioxidants, quinoline antioxidants, and benzimidazole antioxidants. For example, the antioxidant is antioxidant 4020. Specifically, the content of the antioxidant can be 1-5 parts by weight relative to 100 parts by weight of base rubber.

[0074] In this invention, the accelerator is at least one selected from sulfenamide accelerators, thiazole accelerators, thiuram accelerators, and guanidine accelerators. The accelerator may be N-tert-butyl-2-benzothiazole sulfenamide (TBBS) or diphenylguanidine (accelerator D). Specifically, the content of the accelerator relative to 100 parts by weight of base rubber may be 0.5-2.5 parts by weight.

[0075] 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. Specifically, the content of the vulcanizing agent can be 0.5-2.5 parts by weight relative to 100 parts by weight of base rubber.

[0076] The sixth aspect of this invention provides a method for preparing vulcanized rubber, characterized in that the preparation method includes:

[0077] The components of a rubber composition containing rubber processing aids and base rubber are mixed to obtain a mixed rubber preform, and the mixed rubber preform is vulcanized to obtain the vulcanized rubber.

[0078] The rubber processing aid is the aforementioned rubber processing aid.

[0079] In this invention, in the presence of the rubber processing aid provided in the first or third aspect of this invention, the components in the rubber composition are mixed to obtain a mixed rubber preform, and the mixed rubber preform is vulcanized. This can significantly improve the dispersibility and compatibility of the mercapto acid monomers in the rubber processing aid in the base rubber, and can further improve the strength, wear resistance and wet skid resistance of the vulcanized rubber with low heat generation.

[0080] In this invention, the specific processes and operations for mixing the components in the rubber composition and vulcanizing the compound can be carried out with reference to existing technologies. Specifically, the vulcanized rubber is prepared according to the following method:

[0081] S1. The base rubber and rubber processing aids are first mixed to obtain a first compound; wherein the conditions for the first mixing include: mixing time of 1-5 min and mixing temperature of 60-100℃.

[0082] S2. The first compound, silica, carbon black, activator, softener and antioxidant are mixed in a second process to obtain a second compound. The conditions for the second mixing are: mixing time of 5-10 min and mixing temperature of 80-160℃.

[0083] S3. After the second compound is allowed to stand, it is mixed with vulcanizing agent and accelerator in a third mixing process to obtain a compound preform. The standing conditions include: standing at room temperature for more than 4 hours; the third mixing conditions include: mixing time of 3-7 minutes and mixing temperature not exceeding 130°C.

[0084] S4. The mixed rubber blank is vulcanized to obtain tire tread rubber, wherein the vulcanization conditions include: vulcanization temperature of 140-170℃, vulcanization time of 30-40min, and vulcanization pressure of 10-20MPa.

[0085] In this invention, the first mixing, the second mixing, and the third mixing can all be carried out in conventional mixing equipment in the art, such as internal mixers.

[0086] In this invention, the vulcanization can be carried out in conventional vulcanization equipment in the art, such as a flat vulcanizing machine.

[0087] A seventh aspect of the present invention provides a vulcanized rubber prepared by the above-described preparation method.

[0088] The eighth aspect of the present invention provides the use of the above-described rubber composition or vulcanized rubber in tire tread.

[0089] The present invention will be described in detail below through embodiments.

[0090] The equipment used for preparing vulcanized rubber in the following examples and comparative examples is shown in Table 1.

[0091] 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.

[0092] In the following examples and comparative examples, the component amounts are all parts by weight, with each part by weight representing 1g.

[0093] Table 1

[0094] 1 Internal mixer BR1600 Farrell Company, USA 2 Flat vulcanizing machine XLB-D400*400*2 Shanghai No.1 Rubber Machinery Factory

[0095] Table 2

[0096] 1 Tensile strength SHIMADZU AG-20KNG Multi-purpose Tensile Testing Machine Shimadzu Corporation of Japan 2 DIN wear GT-7012-A High-speed rail testing instrument company 3 Dynamic viscoelastic spectrometer EPLEXOR 500N KBA (Germany) 4 Rubber Processing Analyzer RPA2000 Alpha Corporation, USA 5 Dynamic compression fatigue heat generation Y3000E Compression Heat Generation Test Chamber Beijing Youshen Electronic Instruments Co., Ltd.

[0097] Table 3

[0098]

[0099] Preparation Examples 1-6 illustrate the rubber processing aids of the present invention and their preparation methods.

[0100] Preparation Example 1

[0101] At room temperature (25°C), 12 parts by weight of precipitated silica (1165 MPa) and 40 parts by weight of 3-mercaptopropionic acid were stirred evenly to obtain a preloaded mixture. The internal mixer was set to 20°C and 60 rpm. 45 parts by weight of SSBR (10 wt% styrene structural unit content, 40 wt% vinyl content, Mooney viscosity 55) were added to the internal mixer and plasticized for 1 min. Then the preloaded mixture was added to the internal mixer and mixed with the plasticized matrix for 6 min. The rubber processing aid X1 was obtained by discharging the material.

[0102] Preparation Example 2

[0103] At room temperature (25°C), 14 parts by weight of precipitated silica (165GR) and 45 parts by weight of 4-mercaptobutyric acid were stirred evenly to obtain a preloaded mixture. The internal mixer was set to 30°C and 45 rpm. 40 parts by weight of SSBR (20 wt% styrene structural unit content, 70 wt% vinyl content, Mooney viscosity 75) were added to the internal mixer and plasticized for 1.5 min. Then the preloaded mixture was added to the internal mixer and mixed with the plasticized matrix for 4 min. The rubber processing aid X2 was obtained by discharging the material.

[0104] Preparation Example 3

[0105] At room temperature (25°C), 16 parts by weight of precipitated silica (1165 MPa) and 50 parts by weight of 3-mercaptopropionic acid were stirred evenly to obtain a preloaded mixture. The internal mixer was set to 40°C and 30 rpm. 35 parts by weight of SSBR (30 wt% styrene structural unit content, 55 wt% vinyl content, Mooney viscosity 65) was added to the internal mixer and plasticized for 2 min. Then the preloaded mixture was added to the internal mixer and mixed with the plasticized matrix for 3 min. The rubber processing aid X3 was obtained by discharging the material.

[0106] Preparation Example 4

[0107] 20 parts by weight of precipitated silica (1165 MPa) and 60 parts by weight of 3-mercaptopropionic acid were stirred evenly to obtain a preloaded mixture. The internal mixer was set to 40°C and 30 rpm. 35 parts by weight of SSBR (30 wt% styrene structural unit content, 55 wt% vinyl content, Mooney viscosity 65) was added to the internal mixer and plasticized for 2 min. Then the preloaded mixture was added to the internal mixer and mixed with the plasticized matrix for 3 min. The rubber processing aid X4 was obtained by discharging the material.

[0108] Preparation Example 5

[0109] Ten parts by weight of precipitated silica (1165 MPa) and 55 parts by weight of 3-mercaptopropionic acid were stirred evenly to obtain a preloaded mixture. The internal mixer was set to 40°C and 30 rpm. 50 parts by weight of SSBR (30 wt% styrene structural unit content, 55 wt% vinyl content, Mooney viscosity 65) were added to the internal mixer and plasticized for 2 min. Then the preloaded mixture was added to the internal mixer and mixed with the plasticized matrix for 3 min. The rubber processing aid X5 was obtained by discharging the material.

[0110] Preparation Example 6

[0111] 30 parts by weight of precipitated silica (1165 MPa) and 70 parts by weight of 3-mercaptopropionic acid were stirred evenly to obtain a preloaded mixture. The internal mixer was set to 40°C and 30 rpm. 25 parts by weight of SSBR (30 wt% styrene structural unit content, 55 wt% vinyl content, Mooney viscosity 65) was added to the internal mixer and plasticized for 2 min. Then the preloaded mixture was added to the internal mixer and mixed with the plasticized matrix for 3 min. The rubber processing aid X6 was obtained by discharging the material.

[0112] Examples 1-5 illustrate the vulcanized rubber and its preparation method provided by the present invention.

[0113] Example 1

[0114] 70 parts by weight of solution-polymerized styrene-butadiene rubber (Yanshan Petrochemical product, SSBR2636) and 30 parts by weight of butadiene rubber (Yanshan Petrochemical product, BR9000) were added to a mixing mill along with 0.5 parts by weight of rubber processing aid X1 and mixed at 70°C for 3 minutes. Then, 60 parts by weight of silica (Rhodia, France, 165GR), 15 parts by weight of carbon black (Dongguan Qideli Chemical Technology Co., Ltd., N330), 3 parts by weight of zinc oxide (Weifang Hengfeng Chemical Co., Ltd.), 2 parts by weight of stearic acid (Weifang Hengfeng Chemical Co., Ltd.), and 10 parts by weight of aromatic oil (Xindayang (Ningbo) Co., Ltd., TDAE) were added. V500 and 3 parts by weight of antioxidant (Jiangsu Shengao Chemical Technology Co., Ltd., 4020) were added to a mixer and mixed for 7 minutes. After mixing, the mixture was left to stand at room temperature for 5 hours. Then, 2 parts by weight of sulfur (Weifang Zhongheng Chemical Co., Ltd.) and 3 parts by weight of TBBS (N-tert-butyl-2-benzothiazole sulfenamide) were added and mixed at 60°C for 5 minutes to obtain a compound rubber preform. The obtained compound rubber preform was then subjected to flat vulcanization at a vulcanization temperature of 160°C, a vulcanization pressure of 10MPa, and a vulcanization time of 40 minutes to obtain vulcanized rubber sample S1.

[0115] The performance of vulcanized rubber sample S1 was tested, and the results are shown in Table 4.

[0116] Example 2

[0117] 70 parts by weight of solution-polymerized styrene-butadiene rubber (Yanshan Petrochemical product, SSBR2636) and 30 parts by weight of butadiene rubber (Yanshan Petrochemical product, BR9000) and 1 part by weight of rubber processing aid X2 were added to a mixer and mixed at 70°C for 3 minutes. Then, 60 parts by weight of silica (Rhodia, France, 165GR), 15 parts by weight of carbon black (Dongguan Qideli Chemical Technology Co., Ltd., N330), 3 parts by weight of zinc oxide (Weifang Hengfeng Chemical Co., Ltd.), 2 parts by weight of stearic acid (Weifang Hengfeng Chemical Co., Ltd.), and 10 parts by weight of aromatic oil (Xindayang (Ningbo) Co., Ltd., TDAE) were added. V500 and 3 parts by weight of antioxidant (Jiangsu Shengao Chemical Technology Co., Ltd., 4020) were added to a mixer and mixed for 7 minutes. After mixing, the mixture was placed at room temperature for 5 hours. Then, 2 parts by weight of sulfur (Weifang Zhongheng Chemical Co., Ltd.) and 3 parts by weight of TBBS (N-tert-butyl-2-benzothiazole sulfenamide) were added and mixed at 60°C for 5 minutes to obtain a compound rubber preform. The obtained compound rubber preform was then subjected to flat vulcanization at a vulcanization temperature of 160°C, a vulcanization pressure of 10MPa, and a vulcanization time of 40 minutes to obtain vulcanized rubber sample S2.

[0118] The performance of vulcanized rubber sample S2 was tested, and the results are shown in Table 4.

[0119] Example 3

[0120] 70 parts by weight of solution-polymerized styrene-butadiene rubber (Yanshan Petrochemical product, SSBR2636) and 30 parts by weight of butadiene rubber (Yanshan Petrochemical product, BR9000) and 2 parts by weight of rubber processing aid X3 were added to a mixer and mixed at 70°C for 3 minutes. Then, 60 parts by weight of silica (Rhodia, France, 165GR), 15 parts by weight of carbon black (Dongguan Qideli Chemical Technology Co., Ltd., N330), 3 parts by weight of zinc oxide (Weifang Hengfeng Chemical Co., Ltd.), 2 parts by weight of stearic acid (Weifang Hengfeng Chemical Co., Ltd.), and 10 parts by weight of aromatic oil (Xindayang (Ningbo) Co., Ltd., TDAE) were added. V500 and 3 parts by weight of antioxidant (Jiangsu Shengao Chemical Technology Co., Ltd., 4020) were added to a mixer and mixed for 7 minutes. After mixing, the mixture was left to stand at room temperature for 5 hours. Then, 2 parts by weight of sulfur (Weifang Zhongheng Chemical Co., Ltd.) and 3 parts by weight of TBBS (N-tert-butyl-2-benzothiazole sulfenamide) were added and mixed at 60°C for 5 minutes to obtain a compound rubber preform. The obtained compound rubber preform was then subjected to flat vulcanization at a vulcanization temperature of 160°C, a vulcanization pressure of 10MPa, and a vulcanization time of 40 minutes to obtain vulcanized rubber sample S3.

[0121] The performance of vulcanized rubber sample S3 was tested, and the results are shown in Table 4.

[0122] Example 4

[0123] 70 parts by weight of solution-polymerized styrene-butadiene rubber (Yanshan Petrochemical product, SSBR2636) and 30 parts by weight of butadiene rubber (Yanshan Petrochemical product, BR9000) and 3 parts by weight of rubber processing aid X4 were added to a mixer and mixed at 70°C for 3 minutes. Then, 60 parts by weight of silica (Rhodia, France, 165GR), 15 parts by weight of carbon black (Dongguan Qideli Chemical Technology Co., Ltd., N330), 3 parts by weight of zinc oxide (Weifang Hengfeng Chemical Co., Ltd.), 2 parts by weight of stearic acid (Weifang Hengfeng Chemical Co., Ltd.), and 10 parts by weight of aromatic oil (Xindayang (Ningbo) Co., Ltd., TDAE) were added. V500 and 3 parts by weight of antioxidant (Jiangsu Shengao Chemical Technology Co., Ltd., 4020) were added to a mixer and mixed for 7 minutes. After mixing, the mixture was left to stand at room temperature for 5 hours. Then, 2 parts by weight of sulfur (Weifang Zhongheng Chemical Co., Ltd.) and 3 parts by weight of TBBS (N-tert-butyl-2-benzothiazole sulfenamide) were added and mixed at 60°C for 5 minutes to obtain a compound rubber preform. The obtained compound rubber preform was then subjected to flat vulcanization at a vulcanization temperature of 160°C, a vulcanization pressure of 10MPa, and a vulcanization time of 40 minutes to obtain vulcanized rubber sample S4.

[0124] The performance of vulcanized rubber sample S4 was tested, and the results are shown in Table 4.

[0125] Example 5

[0126] Vulcanized rubber was prepared according to the method of Example 1, except that 6 parts by weight of rubber processing aid X5 were added to obtain vulcanized rubber sample S5.

[0127] The performance of vulcanized rubber sample S5 was tested, and the results are shown in Table 4.

[0128] Comparative Example 1

[0129] Vulcanized rubber was prepared according to the method of Example 1, except that the amount of rubber processing aid X1 added was 6 parts by weight, and vulcanized rubber sample DS1 was obtained.

[0130] The performance of vulcanized rubber sample DS1 was tested, and the results are shown in Table 4.

[0131] Comparative Example 2

[0132] Vulcanized rubber was prepared according to the method of Example 1, except that pure 3-mercaptopropionic acid (0.21 parts by weight) was added in the same amount to replace rubber processing aid X1 during the preparation of vulcanized rubber, and vulcanized rubber DS2 was obtained after vulcanization.

[0133] The performance of vulcanized rubber sample DS2 was tested, and the results are shown in Table 4.

[0134] Comparative Example 3

[0135] Vulcanized rubber was prepared according to the method of Example 1, except that the amount of rubber processing aid added was 0.5 parts by weight of X6, and vulcanized rubber sample DS3 was obtained.

[0136] The performance of vulcanized rubber sample DS3 was tested, and the results are shown in Table 4.

[0137] Comparative Example 4

[0138] Vulcanized rubber was prepared according to the method of Example 1, except that no rubber processing aids were added during the preparation of the vulcanized rubber, and vulcanized rubber DS4 was obtained after vulcanization.

[0139] The performance of the vulcanized rubber sample DS4 was tested, and the results are shown in Table 4.

[0140] Table 4

[0141]

[0142] The results above show that the rubber processing aid provided by this invention can improve the dispersion of silica in the rubber matrix, strengthen the interaction between silica and the rubber matrix, thereby better improving the strength of vulcanized rubber, reducing its heat generation, and improving its wet slip resistance.

[0143] Furthermore, comparing the data from Example 1 and Comparative Example 2, it can be seen that when the same rubber composition formulation as in Example 1 is used, but the mercapto acid monomer is added in a different manner, the performance of the further prepared vulcanized rubber DS2 is significantly inferior to that of vulcanized rubber S1. For example, the tensile strength is lower than that of S1, the compression temperature rise is higher than that of S1, and the DIN abrasion is higher than that of S1. The dynamic mechanical properties of the vulcanized rubber of Example 1 show lower rolling resistance and better wet skid resistance. The Penney effect data also indicate that the carbon black dispersion of the vulcanized rubber S1 of Example 1 is significantly better than that of DS2.

[0144] Since the rubber processing aid and preparation method provided by the present invention can make the obtained vulcanized rubber have better performance, when the vulcanized rubber of the present invention is applied to the tread of automobile tires, the durability of the tires and the safety of the automobile can be improved.

[0145] 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 processing aid, characterized in that, The rubber processing aids include mercapto acid monomers, solution-polymerized styrene-butadiene rubber, and silica. The content of the mercapto acid monomer is 60-200 parts by weight relative to 100 parts by weight of solution-polymerized styrene-butadiene rubber, and the content of the silica is 20-66.7 parts by weight. The mercapto acid monomer is provided by at least one of the compounds represented by formula (1): Equation (1), Equation (2), Where x is 0 and R2 is -SH; or, x is 1, M is the structure shown in equation (2), R1 and R2 are each independently H or -SH, and R1 and R2 are not simultaneously H; or, x is 2, M is the structure shown in equation (2), R2 and R1 in the two M are each independently H or -SH, and R2 and R1 in the two M are not simultaneously H; or, x is 3, M is the structure shown in equation (2), R2 and R1 in the three M are each independently H or -SH, and R2 and R1 in the three M are not simultaneously H; The preparation method of the rubber processing aid includes the following steps: (1) Stir the silica and mercapto acid monomers until they are evenly mixed to obtain a preloaded mixture; (2) The solution-polymerized styrene-butadiene rubber is plasticized to obtain plasticized rubber; (3) The preloaded mixture is mixed with the plasticized rubber to obtain the rubber processing aid.

2. The rubber processing aid according to claim 1, wherein, The content of the mercapto acid monomer is 89-143 parts by weight relative to 100 parts by weight of solution-polymerized styrene-butadiene rubber, and the content of the silica is 27-46 parts by weight.

3. The rubber processing aid according to claim 1 or 2, wherein, In the solution-polymerized styrene-butadiene rubber, the styrene structural unit content is 10-30 wt%, and the vinyl content is 40-70 wt%.

4. The rubber processing aid according to claim 1 or 2, wherein, The Mooney viscosity of the solution-polymerized styrene-butadiene rubber is 55-75.

5. A method for preparing a rubber processing aid, characterized in that, The preparation method includes the following steps: (1) Stir the silica and mercapto acid monomers until they are evenly mixed to obtain a preloaded mixture; (2) The solution-polymerized styrene-butadiene rubber is plasticized to obtain plasticized rubber; (3) The preloaded mixture is mixed with the plasticized rubber to obtain the rubber processing aid; The content of the mercapto acid monomer is 60-200 parts by weight relative to 100 parts by weight of solution-polymerized styrene-butadiene rubber, and the content of the silica is 20-66.7 parts by weight. The mercapto acid monomer is provided by at least one of the compounds represented by formula (1): Equation (1), Equation (2), Where x is 0 and R2 is -SH; or, x is 1, M is the structure shown in equation (2), R1 and R2 are each independently H or -SH, and R1 and R2 are not simultaneously H; or, x is 2, M is the structure shown in equation (2), R2 and R1 in the two M are each independently H or -SH, and R2 and R1 in the two M are not simultaneously H; or, x is 3, M is the structure shown in equation (2), R2 and R1 in the three M are each independently H or -SH, and R2 and R1 in the three M are not simultaneously H.

6. The preparation method according to claim 5, wherein, The content of the mercapto acid monomer is 89-143 parts by weight relative to 100 parts by weight of solution-polymerized styrene-butadiene rubber, and the content of the silica is 27-46 parts by weight.

7. The preparation method according to claim 5 or 6, wherein, In the solution-polymerized styrene-butadiene rubber, the styrene structural unit content is 10-25 wt%, and the vinyl content is 40-70 wt%.

8. The preparation method according to claim 5 or 6, wherein, The Mooney viscosity of the solution-polymerized styrene-butadiene rubber is 55-75.

9. The preparation method according to claim 5 or 6, wherein, The plasticizing conditions include: plasticizing temperature of 20-40℃, rotation speed of 30-60rpm, and plasticizing time of 1-2min.

10. The preparation method according to claim 5 or 6, wherein, The plasticizing is carried out in an internal mixer.

11. The preparation method according to claim 5 or 6, wherein, The mixing conditions include: mixing time of 3-6 minutes and mixing temperature of 60-90℃.

12. The use of the rubber processing aid according to any one of claims 1-4 in the preparation of vulcanized rubber.

13. A rubber composition, characterized in that, The rubber composition comprises the rubber processing aid and base rubber as described in any one of claims 1-4; The amount of the rubber processing aid is 0.2-4 parts by weight relative to 100 parts by weight of base rubber.

14. The rubber composition according to claim 13, wherein, The amount of the rubber processing aid is 0.5-2 parts by weight relative to 100 parts by weight of base rubber.

15. A method for preparing vulcanized rubber, characterized in that, The preparation method includes: The components in a rubber composition containing rubber processing aids and base rubber are mixed to obtain a mixed rubber preform, and the mixed rubber preform is vulcanized to obtain the vulcanized rubber. The rubber processing aid is the rubber processing aid described in any one of claims 1-4.

16. A vulcanized rubber prepared by the preparation method of claim 15.

17. The use of the rubber composition of claim 13 or 14 or the vulcanized rubber of claim 16 in a tire tread.

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