CN110551236A - Modified styrene-butadiene rubber and preparation method thereof, rubber composition, vulcanized rubber and preparation method and application thereof - Google Patents

Abstract

The invention relates to the field of rubber, and discloses modified styrene-butadiene rubber, a preparation method thereof, a rubber composition, vulcanized rubber, a preparation method thereof and application thereof, wherein the modified styrene-butadiene rubber is formed by grafting a polar modifier onto styrene-butadiene rubber, the grafting ratio of the polar modifier is 0.5-5 mol% based on the total molar weight of vinyl structural units in the styrene-butadiene rubber forming the modified styrene-butadiene rubber, the gel content of the modified styrene-butadiene rubber is 3.5-10 wt%, and the polar modifier is at least one of mercapto acid monomers. The modified styrene-butadiene rubber provided by the invention can be beneficial to the interaction of white carbon black in a rubber matrix, can better improve the strength of vulcanized rubber prepared by further vulcanization, reduces the heat generation of the vulcanized rubber, and improves the wet skid resistance of a vulcanized rubber material.

Description

Modified styrene-butadiene rubber and its preparation method, rubber composition, vulcanized rubber and its Preparation method and application

technical field

The present invention relates to the field of rubber, in particular to a modified styrene-butadiene rubber, a method for preparing modified styrene-butadiene rubber, a rubber composition, a method for preparing vulcanized rubber, and vulcanized rubber and vulcanized rubber prepared by the method. The application of the vulcanized rubber in tire treads.

Background technique

In the 1990s, Michelin introduced the precipitation silica filling technology for the preparation of high-performance tires, and disclosed silica as a new type of reinforcing filler, which can provide good mechanical properties, high elasticity, and low rolling. resistance and low flex heat generation. Since then, the application of silica in high-performance tires has attracted great interest from both industry and academia.

The styrene-butadiene rubber/silica composite material can well balance the comprehensive properties of mechanical strength, resilience, rolling resistance and high wet skid resistance, and has become one of the most important materials in green tires.

The degree of dispersion of the filler and the interaction between the filler and the rubber are key factors that determine the properties of the composite. However, the surface of silica is rich in silicon hydroxyl groups, and its surface polarity is quite different from that of styrene-butadiene rubber, which makes it difficult for silica to obtain good dispersion in the rubber matrix. In order to solve this problem, domestic and foreign scholars have done a lot of work.

At present, the most successful method is to apply silane coupling agent to the surface of silica for modification to improve the dispersion effect of silica in the matrix. Although the silane coupling agent improves the compatibility between the rubber matrix and silica to a certain extent, due to the unique surface structure of silica, its self-aggregation tendency is still obvious.

In addition, the polarized modification of the rubber matrix is also an effective method to improve the dispersion of fillers and promote the interaction between fillers and the matrix. CN103509159A discloses a modified solution-polymerized butadiene styrene prepared by a solution method, and discloses that when the obtained modified solution-polymerized butadiene has a gel content of 1 to 3% by weight, the modified solution-polymerized butadiene has better application performance. However, the solution method for preparing modified solution-polymerized butadiene-styrene has the disadvantages of high energy consumption, large pollution and low efficiency.

In view of the above defects, it is necessary to provide a modified rubber with simple preparation process, low energy consumption and low pollution, which can improve the dispersion of silica and have excellent dynamic performance when used in tire treads.

Contents of the invention

One of the purposes of the present invention is to solve the problems of how to improve the dispersibility of silica used in tire treads, reduce heat generation, and improve wet skid resistance.

The second object of the present invention is to provide a modified styrene-butadiene rubber, a preparation method thereof, and a rubber composition containing the styrene-butadiene rubber.

The third object of the present invention is to provide a vulcanized rubber formed from the aforementioned modified styrene-butadiene rubber.

The inventors of the present invention have found in research that the polar modifier grafted by styrene-butadiene rubber when the gel content is in the range of 3.5 to 10% by weight and the grafting rate of the polar modifier is 0.5 to 5mol% When the formed modified styrene-butadiene rubber is used to form vulcanized rubber, it can improve the dispersibility of silica in the tire tread to which the vulcanized rubber is applied, reduce heat generation, and improve wet skid resistance. Accordingly, the technical solution of the present invention has been completed.

The first aspect of the present invention provides a kind of modified styrene-butadiene rubber, which is formed by grafting polar modifier of styrene-butadiene rubber, and is characterized in that, to form the said modified styrene-butadiene rubber Based on the total molar weight of vinyl structural units in the styrene-butadiene rubber, the graft ratio of the polar modifier is 0.5-5 mol%, and the gel content of the modified styrene-butadiene rubber is 3.5-10% by weight , and the polar modifier is at least one of the mercapto acid-based monomers.

A second aspect of the present invention provides a method for preparing modified styrene-butadiene rubber, the method comprising:

(1) SBR is carried out mastication, obtains the styrene-butadiene rubber after mastication;

(2) Mix the polar modifier with the masticated styrene-butadiene rubber to carry out kneading until the polar modifier in the obtained modified styrene-butadiene rubber is equal to the vinyl group in the styrene-butadiene rubber The graft ratio based on the total molar weight of the structural units is 0.5-5 mol%, and the gel content of the modified styrene-butadiene rubber is 3.5-10% by weight,

Wherein, the rotating speed of the described mixing process in the control step (2) is 55～75rpm; And

The polar modifier is at least one of the mercapto acid-based monomers, and the amount of the polar modifier is 0.2-1.2 parts by weight relative to 100 parts by weight of the styrene-butadiene rubber.

The third aspect of the present invention provides a kind of rubber composition, contains component A, component B, component C and component D that keep separately in this composition, and described component A is modified styrene-butadiene rubber, The component B contains white carbon black, the component C contains an activator, an anti-aging agent, a softener and optionally carbon black, and the component D contains an accelerator and a vulcanizing agent, wherein the The modified styrene-butadiene rubber is the modified styrene-butadiene rubber described in the first aspect of the present invention and/or the modified styrene-butadiene rubber prepared by the method described in the second aspect of the present invention.

A fourth aspect of the present invention provides a method for preparing vulcanized rubber, the method comprising:

(1) carry out first mixing with the modified styrene-butadiene rubber as component A and component B containing white carbon black, obtain one section of masterbatch;

(2) Carrying out second mixing of the one-stage masterbatch with component C containing an activator, an anti-aging agent, a softener and optional carbon black, to obtain a second-stage masterbatch;

(3) The second-stage masterbatch is mixed with the component D containing accelerator and vulcanizing agent for the third time to obtain the final compound;

(4) vulcanizing the final rubber mix;

Wherein, the modified styrene-butadiene rubber is the modified styrene-butadiene rubber described in the first aspect of the present invention and/or the modified styrene-butadiene rubber prepared by the method described in the second aspect of the present invention.

The fifth aspect of the present invention provides the vulcanized rubber prepared by the method described in the aforementioned fourth aspect.

A sixth aspect of the present invention provides the use of the vulcanized rubber described in the aforementioned fifth aspect in a tire tread.

The modified styrene-butadiene rubber provided by the present invention can be beneficial to the interaction of white carbon black in the rubber matrix, can better improve the strength of the vulcanized rubber obtained by further vulcanization, reduce the heat generation of the vulcanized rubber, and improve the resistance of the vulcanized rubber compound. slippery.

Detailed ways

Neither the endpoints nor any values of the ranges disclosed herein are limited to such precise ranges or values, and these ranges or values are understood to include values approaching these ranges or values. For numerical ranges, between the endpoints of each range, between the endpoints of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, these values Ranges should be considered as specifically disclosed herein.

As mentioned above, the first aspect of the present invention provides a modified styrene-butadiene rubber, the modified styrene-butadiene rubber is formed by grafting a polar modifier to the styrene-butadiene rubber, and it is characterized in that, to form the modified styrene-butadiene rubber In terms of the total molar weight of vinyl structural units in the styrene-butadiene rubber of styrene-butadiene rubber, the grafting rate of the polar modifier is 0.5 to 5 mol%, and the gel content of the modified styrene-butadiene rubber is 3.5-10% by weight, and the polar modifier is at least one of the mercapto acid-based monomers.

The "mercapto acid-based monomer" in the present invention means: an alkane monomer containing both mercapto and carboxyl groups in its molecule.

In the present invention, the polar modifier is at least one of the mercapto acid monomers, that is, in the present invention, the polar modifier can be formed from two or more mercapto acid monomers. Compositions.

In the first aspect of the present invention, in order to further improve the wet skid resistance of the vulcanized rubber compound obtained by modified styrene-butadiene rubber, preferably, the mercapto acid-based monomer is composed of compounds represented by formula (1) at least one of the offers,

In formula (1), M is the structure shown in formula (2), x is an integer of 0-3, R ₂ is H or -SH, in formula (2), R ₁ is H or -SH, and , the R ₁ and R ₂ are not H at the same time.

In the first aspect of the present invention, in order to further improve the wet skid resistance of the vulcanized rubber compound obtained from modified styrene-butadiene rubber, more preferably, in the mercapto acid monomer, in formula (1),

x is ₀ , and R2 is -SH; or

x is 1, M is the structure shown in formula (2), R ₁ and R ₂ are each independently H or -SH, and R ₁ and R ₂ are not H at the same time; or

x is 2, M is the structure shown in formula (2), R ₂ and R ₁ in the two Ms are each independently H or -SH, and R ₂ and R ₁ in the two Ms are not H at the same time; or

x is 3, M is the structure shown in formula (2), R ₂ and R ₁ in the 3 Ms are each independently H or -SH, and R ₂ and R ₁ in the 3 Ms are not H at the same time.

In the first aspect of the present invention, in order to further improve the wet skid resistance of the vulcanized rubber compound obtained from the modified styrene-butadiene rubber, it is particularly preferred that in the mercapto acid monomer, in the formula (1) ,

x is 1, M is the structure shown in formula (2), R ₁ and R ₂ are each independently H or -SH, and R ₁ and R ₂ are not H at the same time; or

x is 2, M is the structure shown in formula (2), one of the group formed by R ₂ and R ₁ in 2 M is -SH, and the other 2 are H; or

x is 3, M is the structure shown in formula (2), one of the group formed by R ₂ and R ₁ in the three Ms is -SH, and the other three are H.

In the first aspect of the present invention, most preferably, the polar modifier is at least one of 3-mercaptopropionic acid, 4-mercaptobutyric acid and 2-mercaptopropionic acid.

Preferably, the content of styrene structural units in the styrene-butadiene rubber is 15-30% by weight, the content of vinyl groups is 30-70% by weight, and the Mooney viscosity is 45-80.

As previously stated, a second aspect of the present invention provides a method for preparing modified styrene-butadiene rubber, the method comprising:

(1) SBR is carried out mastication, obtains the styrene-butadiene rubber after mastication;

(2) Mix the polar modifier with the masticated styrene-butadiene rubber to carry out kneading until the polar modifier in the obtained modified styrene-butadiene rubber is equal to the vinyl group in the styrene-butadiene rubber The graft ratio based on the total molar weight of the structural units is 0.5-5 mol%, and the gel content of the modified styrene-butadiene rubber is 3.5-10% by weight,

Wherein, the rotating speed of the described mixing process in the control step (2) is 55～75rpm; And

The polar modifier is at least one of the mercapto acid-based monomers, and the amount of the polar modifier is 0.2-1.2 parts by weight relative to 100 parts by weight of the styrene-butadiene rubber.

In particular, the inventors of the present invention have found that when the rotational speed of the mixing process in the control step (2) is 55-75rpm, the obtained modified styrene-butadiene rubber can obviously benefit the interaction of silica in the rubber matrix. It can better improve the strength of the vulcanized rubber obtained by further vulcanization, reduce the heat generation of the vulcanized rubber, and improve the wet skid resistance of the vulcanized rubber compound.

In the second aspect of the present invention, preferably, the mercapto acid monomer is provided by at least one of the compounds represented by formula (1),

In formula (1), M is the structure shown in formula (2), x is an integer of 0-3, R ₂ is H or -SH, in formula (2), R ₁ is H or -SH, and , the R ₁ and R ₂ are not H at the same time.

In the second aspect of the present invention, more preferably, in the mercapto acid-based monomer, in formula (1),

x is ₀ , and R2 is -SH; or

x is 1, M is the structure shown in formula (2), R ₁ and R ₂ are each independently H or -SH, and R ₁ and R ₂ are not H at the same time; or

x is 2, M is the structure shown in formula (2), R ₂ and R ₁ in the two Ms are each independently H or -SH, and R ₂ and R ₁ in the two Ms are not H at the same time; or

x is 3, M is the structure shown in formula (2), R ₂ and R ₁ in the 3 Ms are each independently H or -SH, and R ₂ and R ₁ in the 3 Ms are not H at the same time.

In the second aspect of the present invention, particularly preferably, in the mercapto acid-based monomer, in formula (1),

x is 1, M is the structure shown in formula (2), R ₁ and R ₂ are each independently H or -SH, and R ₁ and R ₂ are not H at the same time; or

x is 2, M is the structure shown in formula (2), one of the group formed by R ₂ and R ₁ in 2 M is -SH, and the other 2 are H; or

x is 3, M is the structure shown in formula (2), one of the group formed by R ₂ and R ₁ in the three Ms is -SH, and the other three are H.

In the second aspect of the present invention, most preferably, the polar modifier is at least one of 3-mercaptopropionic acid, 4-mercaptobutyric acid and 2-mercaptopropionic acid.

Preferably, the kneading conditions include: the temperature is 70-130°C, and the time is 1-5 min; more preferably, the kneading conditions include: the temperature is 90-110°C, and the time is 2-3 min.

Preferably, the conditions of mastication include: the rotation speed is 40-100 rpm, the temperature is 80-120°C, and the time is 0.5-5 minutes.

In the case of no special instructions, the characteristics of the modified styrene-butadiene rubber involved in the second aspect of the present invention and the styrene-butadiene rubber and the polar modifier forming the modified styrene-butadiene rubber are all the same as those of the first aspect of the present invention. The corresponding features in the aspects are the same, and the present invention will not repeat them one by one here.

As mentioned above, the third aspect of the present invention provides a rubber composition, which contains component A, component B, component C and component D which are kept independently, and the component A is modified styrene-butadiene rubber, the component B contains white carbon black, the component C contains an activator, an anti-aging agent, a softener and optionally carbon black, and the component D contains an accelerator and a vulcanizing agent , wherein the modified styrene-butadiene rubber is the modified styrene-butadiene rubber described in the first aspect of the present invention and/or the modified styrene-butadiene rubber prepared by the method described in the second aspect of the present invention.

The "optionally containing carbon black" means that the rubber composition of the present invention may or may not contain carbon black. Preferably, the rubber composition contains carbon black.

Preferably, relative to 100 parts by weight of the modified styrene-butadiene rubber, the content of the silica is 20-120 parts by weight, more preferably 50-100 parts by weight.

Preferably, relative to 100 parts by weight of the modified styrene-butadiene rubber, the content of the activator is 1-15 parts by weight, the content of the anti-aging agent is 0.5-10 parts by weight, and the content of the softener is 5-30 parts by weight, the content of the carbon black is 0-30 parts by weight, the content of the accelerator is 0.5-10 parts by weight, and the content of the vulcanizing agent is 0.1-5 parts by weight.

More preferably, relative to 100 parts by weight of the modified styrene-butadiene rubber, the content of the activator is 3-8 parts by weight, the content of the anti-aging agent is 1-6 parts by weight, and the content of the softener 10-20 parts by weight, the content of the carbon black is 0-20 parts by weight, the content of the accelerator is 1-6 parts by weight, and the content of the vulcanizing agent is 0.5-3 parts by weight.

In the present invention, the content of the carbon black is 0 to 20 parts by weight, which means: when no carbon black is contained, the content of the carbon black is 0 parts by weight; when carbon black is contained, the content of the carbon black is More than 0 to less than or equal to 20 parts by weight.

Preferably, the white carbon black is silicon dioxide; more preferably, the nitrogen adsorption specific surface area of the white carbon black is 10-200 m ² /g. For example, the white carbon black is 115GR (French Rhodia Company) and/or 165GR (French Rhodia Company).

Preferably, the activator is a combination of metal oxide and fatty acid or fatty acid metal soap salt. The metal oxide is preferably zinc oxide and/or magnesium oxide; the fatty acid is preferably stearic acid; the fatty acid metal soap salt is zinc stearate and/or zinc borate.

Preferably, the antiaging agent is at least one of amine antiaging agents, quinoline antiaging agents and benzimidazole antiaging agents. For example, the anti-aging agent is anti-aging agent 4020 or anti-aging agent RD.

Preferably, the softening agent is at least one of aromatic oil, paraffin oil, naphthenic oil, petroleum resin and polyethylene glycol. Wherein, the weight average molecular weight of the polyethylene glycol is 3000-5000. Moreover, the polyethylene glycol with a weight-average molecular weight in the range of 3000-5000 makes the material have better processability and physical and mechanical properties. The aromatic oil may be, for example, aromatic oil TDAE V500, and the polyethylene glycol may be, for example, polyethylene glycol PEG4000.

Preferably, when carbon black is contained, the carbon black has a CTAB adsorption specific surface area of 10-300 m ² /g. For example, the carbon black is N330 (Dongguan Qideli Chemical Technology Co., Ltd.) and/or N220 (Dongguan Qideli Chemical Technology Co., Ltd.).

Preferably, the accelerator is at least one of sulfenamide accelerators, thiazole accelerators, thiuram accelerators and guanidine accelerators. Preferably, the accelerator is N-tert-butyl-2-benzothiazole sulfenamide (TBBS), diphenylguanidine (accelerator D), tetramethylthiuram disulfide (TMTD).

Preferably, 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 common sulfur S, oil-extended insoluble sulfur IS, and the like.

As previously mentioned, the fourth aspect of the present invention provides a method for preparing vulcanized rubber, the method comprising:

(1) carry out first mixing with the modified styrene-butadiene rubber as component A and component B containing white carbon black, obtain one section of masterbatch;

(2) Carrying out second mixing of the one-stage masterbatch with component C containing an activator, an anti-aging agent, a softener and optional carbon black, to obtain a second-stage masterbatch;

(3) The second-stage masterbatch is mixed with the component D containing accelerator and vulcanizing agent for the third time to obtain the final compound;

(4) vulcanizing the final rubber mix;

Wherein, the modified styrene-butadiene rubber is the modified styrene-butadiene rubber described in the first aspect of the present invention and/or the modified styrene-butadiene rubber prepared by the method described in the second aspect of the present invention.

In fact, in the method for preparing vulcanized rubber, the amount of each component involved in the preparation of vulcanized rubber can be the same as the content of the corresponding components in the rubber composition involved in the third aspect of the present invention, therefore, in order to avoid duplication , In the fourth aspect of the present invention, the amounts of each component involved in the preparation of vulcanized rubber are not listed one by one, and those skilled in the art should not understand it as a limitation of the present invention.

Preferably, the conditions for the first mixing include: the temperature is 100-150°C, and the time is 3-10 minutes. More preferably, the conditions for the first mixing include: the temperature is 110-120° C., and the time is 5-7 minutes.

Preferably, the conditions for the second mixing include: the temperature is 80-140°C, and the time is 3-12 minutes; more preferably, the conditions for the second mixing include: the temperature is 110-130°C, and the time is 3-12 minutes. 3~5min.

Preferably, the conditions for the third mixing include: the temperature is no more than 130°C, and the time is 5-7 minutes. More preferably, the temperature of the third kneading is 110-130°C.

Preferably, the vulcanization conditions include: a temperature of 150-170°C, a pressure of 10-20 MPa, and a time of 30-50 minutes.

The vulcanized rubber of the present invention is obtained by a new mixing method. In the method, a section of white carbon black masterbatch is prepared by using modified styrene-butadiene rubber with specific gel content and grafting ratio; and then in the white carbon black masterbatch Add activator, anti-aging agent, softener, etc. to mix to prepare the second-stage masterbatch, then add vulcanizing agent and accelerator to the second-stage masterbatch to prepare the final rubber, and finally vulcanize the final rubber to obtain vulcanized rubber. The vulcanized rubber thus obtained has excellent wet skid resistance.

As mentioned above, the fifth aspect of the present invention provides the vulcanized rubber prepared by the method described in the aforementioned fourth aspect.

As mentioned above, the sixth aspect of the present invention provides the use of the vulcanized rubber described in the aforementioned fifth aspect in tire treads.

The pressure used in the present invention is gauge pressure.

The present invention will be described in detail below by way of examples.

Unless otherwise specified, the various commodities used below are all from commercial purchases.

The equipment situation of following preparation example, embodiment and comparative example is shown in Table 1.

The test instruments of the preparation examples, examples and comparative examples are shown in Table 2, and the test conditions are shown in Table 3.

The chemical reagents that preparation example, embodiment and comparative example use are commercially available, specifically as follows:

Solution polystyrene butadiene rubber: 2506, Yanshan Petrochemical Products (wherein, the styrene structural unit content is 23% by weight, the vinyl content is 63% by weight, and the Mooney viscosity is 60);

White carbon black: 165GR, French Rhodia company, nitrogen adsorption specific surface area is 170m ² /g;

Carbon black: N330, Dongguan Qideli Chemical Technology Co., Ltd., CTAB adsorption specific surface area is 75m ² /g;

Polar modifier: 3-mercaptopropionic acid (Shandong Xinchang Chemical Technology Co., Ltd.), 4-mercaptobutyric acid (Zhengzhou Keyulong Chemical Products Co., Ltd.), 2-mercaptopropionic acid (Bailingwei Technology Co., Ltd.);

Softener: environmentally friendly aromatic oil TDAE V500 (TDAE for short), Xindayang (Ningbo) Co., Ltd.;

Activator: zinc oxide, stearic acid, Weifang Hengfeng Chemical Co., Ltd.;

Antiaging agent: N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (antiaging agent 4020), 2,2,4-trimethyl-1,2-dihydroquinoline Polymer (antiaging agent RD), Jiangsu Sunon Chemical Technology Co., Ltd.;

Vulcanizing agent: sulfur, Weifang Zhongheng Chemical Co., Ltd.;

Accelerator: N-tert-butyl-2-benzothiazole sulfenamide (TBBS), diphenylguanidine (accelerator D), tetramethylthiuram disulfide (TMTD), Shanghai Yongyan Chemical Technology Co., Ltd.;

PEG4000: Huaihaian Petrochemical Plant.

The amounts of the components in the following preparation examples, examples and comparative examples are all parts by weight, and each part by weight represents 1 g.

Table 1

serial number device name model Manufacturer 1 Internal mixer BR1600 american farrell corp. 2 Flat vulcanizing machine XLB-D400*400*2 Shanghai No.1 Rubber Machinery Factory

Table 2

serial number Test items Test instrument model Manufacturer 1 Tensile Strength Universal tensile machine, SHIMADZU, AG-20KNG Shimadzu Corporation 2 resilience ZWICK 5109 Germany ZWICK company 3 DIN wear GT-7012-A High-speed rail testing instrument company 4 Dynamic Viscoelastic Spectrometer EPLEXOR 500N KBA 5 Rubber Processing Analyzer RPA2000 american alpha corp. 6 Dynamic compression fatigue heat generation Compression heat generation test machine Y3000E Beijing Youshen Electronic Instrument Co., Ltd.

table 3

Preparation Example 1: Preparation of Modified Styrene Butadiene Rubber G1

Add 100 parts by weight of solution-polymerized styrene-butadiene rubber into the internal mixer, set the internal mixer speed to 55rpm, masticate the temperature to 80°C, and the raw rubber mastication time to 0.5min, keep the internal mixer speed to 55rpm, and then 0.2 parts by weight of the polar modifier 2-mercaptopropionic acid was added to an internal mixer and mixed at a temperature of 90° C. for 3 minutes to obtain modified styrene-butadiene rubber G1.

In terms of the total molar weight of vinyl structural units in the styrene-butadiene rubber forming the modified styrene-butadiene rubber G1, the grafting rate of the polar modifier is 0.5mol%, and the modified styrene-butadiene rubber G1 The gel content was 3.5% by weight.

Preparation Example 2: Preparation of Modified Styrene Butadiene Rubber G2

Add 100 parts by weight of solution-polymerized styrene-butadiene rubber into the internal mixer, set the internal mixer speed to 80rpm, the masticating temperature to 80°C, and the raw rubber mastication time to 0.5min; adjust the internal mixer speed to 75rpm, and then 0.5 parts by weight of the polar modifier 4-mercaptobutyric acid was added to an internal mixer and mixed at a temperature of 100° C. for 2.5 minutes to obtain modified styrene-butadiene rubber G2.

In terms of the total molar weight of the vinyl structural unit in the described styrene-butadiene rubber forming the modified styrene-butadiene rubber G2, the grafting rate of the polar modifier is 3mol%, and the gelation rate of the modified styrene-butadiene rubber G2 is The gum content was 6% by weight.

Preparation Example 3: Preparation of Modified Styrene Butadiene Rubber G3

Add 100 parts by weight of solution-polymerized styrene-butadiene rubber into the internal mixer, set the internal mixer speed to 60rpm, masticate the temperature to 80°C, and the raw rubber mastication time to 0.5min, keep the internal mixer speed to 60rpm, and then 1.2 parts by weight of the polar modifier 3-mercaptopropionic acid was added to an internal mixer and mixed at a temperature of 110° C. for 2 minutes to obtain modified styrene-butadiene rubber G3.

In terms of the total molar weight of the vinyl structural unit in the described styrene-butadiene rubber forming the modified styrene-butadiene rubber G3, the grafting ratio of the polar modifier is 5mol%, and the gelation rate of the modified styrene-butadiene rubber G3 is The gum content was 10% by weight.

Embodiment 1: Preparation of composition formulation and vulcanized rubber S1

Prescription: modified styrene-butadiene rubber G1 is 100 parts by weight, white carbon black 50 parts by weight, carbon black 30 parts by weight, TDAE (softener) 15 parts by weight, zinc oxide 1.5 parts by weight, stearic acid 1.5 parts by weight, sulfur ( Vulcanizing agent) 0.5 parts by weight, 2 parts by weight of TBBS (accelerator), 4 parts by weight of D (accelerator), 1 part by weight of antiaging agent 4020 (antiaging agent), 5 parts by weight of PEG4000 (softening agent).

The preparation of vulcanized rubber adopts the technique in the specific embodiment of the present invention to carry out, and concrete process condition is as follows:

In the process of preparing a section of masterbatch, the temperature of the first mixing is 110°C, and the time is 7 minutes;

In the process of preparing the second-stage masterbatch, the temperature of the second mixing is 110°C, and the time is 5 minutes;

In the process of preparing the final rubber mix, the temperature of the third mixing (glue discharge temperature) is 130°C, and the time is 5 minutes;

Put the final compounded rubber into a flat vulcanizer for vulcanization. The vulcanization temperature is 150°C, the vulcanization pressure is 20MPa, and the vulcanization time is 50min to obtain vulcanized rubber sample S1.

The vulcanized rubber sample S1 was subjected to a performance test, and the results are shown in Table 4.

Embodiment 2: the preparation of composition formulation and vulcanized rubber S2

Prescription: modified styrene-butadiene rubber G2 is 100 parts by weight, 77 parts by weight of white carbon black, 8 parts by weight of carbon black, 10 parts by weight of TDAE (softener), 2 parts by weight of zinc oxide, 3 parts by weight of stearic acid, sulfur ( Vulcanizing agent) 1.7 parts by weight, TBBS (accelerator) 1.8 parts by weight, D (accelerator) 1.8 parts by weight, antioxidant 4020 (antiaging agent) 2 parts by weight, PEG4000 (softening agent) 4 parts by weight.

The preparation of vulcanized rubber adopts the technique in the specific embodiment of the present invention to carry out, and concrete process condition is as follows:

In the process of preparing a section of masterbatch, the temperature of the first mixing is 120°C, and the time is 5 minutes;

In the process of preparing the second-stage masterbatch, the temperature of the second mixing is 120°C, and the time is 4 minutes;

In the process of preparing the final rubber mix, the temperature of the third mixing is 110°C, and the time is 7 minutes;

Put the final compounded rubber into a flat vulcanizer for vulcanization. The vulcanization temperature is 170°C, the vulcanization pressure is 10MPa, and the vulcanization time is 30 minutes to obtain vulcanized rubber sample S2.

The vulcanized rubber sample S2 was subjected to a performance test, and the results are shown in Table 4.

Embodiment 3: the preparation of composition formulation and vulcanized rubber S3

Formula: 100 parts by weight of modified styrene-butadiene rubber G3, 100 parts by weight of white carbon black, 8 parts by weight of TDAE (softener), 5 parts by weight of zinc oxide, 3 parts by weight of stearic acid, and 3 parts by weight of sulfur (vulcanizing agent) , 0.5 parts by weight of TBBS (accelerator), 0.5 parts by weight of D (accelerator), 6 parts by weight of antioxidant 4020 (antiaging agent), 2 parts by weight of PEG4000 (softener).

The preparation of vulcanized rubber adopts the technique in the specific embodiment of the present invention to carry out, and concrete process condition is as follows:

In the process of preparing a section of masterbatch, the temperature of the first mixing is 115°C, and the time is 6 minutes;

In the process of preparing the second-stage masterbatch, the temperature of the second mixing is 130°C, and the time is 3 minutes;

In the process of preparing the final rubber mix, the temperature of the third mixing is 120°C, and the time is 6 minutes;

Put the final compounded rubber into a flat vulcanizer for vulcanization. The vulcanization temperature is 160°C, the vulcanization pressure is 15MPa, and the vulcanization time is 40min to obtain vulcanized rubber sample S3.

The vulcanized rubber sample S3 was subjected to a performance test, and the results are shown in Table 4.

Embodiment 4: the preparation of composition formulation and vulcanized rubber S4

Formula: 100 parts by weight of modified styrene-butadiene rubber G3, 100 parts by weight of white carbon black, 15 parts by weight of TDAE (softener), 5 parts by weight of zinc oxide, 5 parts by weight of stearic acid, and 4 parts by weight of sulfur (vulcanizing agent) , 3.5 parts by weight of TBBS (accelerator), 3.5 parts by weight of D (accelerator), 7 parts by weight of antioxidant 4020 (antiaging agent), 5 parts by weight of PEG4000 (softener).

The preparation of vulcanized rubber adopts the technique in the specific embodiment of the present invention to carry out, and concrete process condition is as follows:

In the process of preparing a section of masterbatch, the temperature of the first mixing is 140°C, and the time is 4 minutes;

In the process of preparing the second-stage masterbatch, the temperature of the second mixing is 140°C, and the time is 3 minutes;

In the process of preparing the final rubber mix, the temperature of the third mixing is 120°C, and the time is 6 minutes;

Put the final mixed rubber into a flat vulcanizer for vulcanization. The vulcanization temperature is 160°C, the vulcanization pressure is 15 MPa, and the vulcanization time is 40 minutes to obtain vulcanized rubber sample S4.

The performance test of the vulcanized rubber sample S4 is shown in Table 4.

Comparative example 1

The preparation process of modified styrene-butadiene rubber is as follows: add 100 parts by weight of solution-polymerized styrene-butadiene rubber into the internal mixer, set the speed of the internal mixer to 80rpm, the plasticizing temperature to 80°C, and the raw rubber plasticating time to 0.5min. Keep the internal mixer speed at 80rpm, then add 0.1 parts by weight of polar modifier 3-mercaptopropionic acid into the internal mixer for mixing, the mixing temperature is 130°C, and the mixing time is 5min to obtain modified butylbenzene Rubber DG1.

In terms of the total molar weight of vinyl structural units in the styrene-butadiene rubber forming the modified styrene-butadiene rubber DG1, the grafting rate of the polar modifier is 0.2mol%, and the modified styrene-butadiene rubber DG1 The gel content was 3% by weight.

The formula of the rubber composition of this comparative example is: modified styrene-butadiene rubber DG1 is 100 parts by weight, white carbon black 100 parts by weight, TDAE (softening agent) 8 parts by weight, zinc oxide 5 parts by weight, stearic acid 3 parts by weight , 3 parts by weight of sulfur (vulcanizing agent), 0.5 parts by weight of TBBS (accelerator), 0.5 parts by weight of D (accelerator), 6 parts by weight of antioxidant 4020 (antiaging agent), 2 parts by weight of PEG4000 (softening agent).

The preparation of vulcanized rubber adopts the same process as in Example 3 to obtain vulcanized rubber sample DS1.

The performance test of the vulcanized rubber sample DS1 is shown in Table 4.

Comparative example 2

The preparation process of modified styrene-butadiene rubber is as follows: add 100 parts by weight of solution-polymerized styrene-butadiene rubber into the internal mixer, set the speed of the internal mixer to 80rpm, the plasticizing temperature to 80°C, and the raw rubber plasticating time to 0.5min. Keep the internal mixer speed at 80rpm, then add 2 parts by weight of polar modifier 3-mercaptopropionic acid into the internal mixer for mixing, the mixing temperature is 130°C, and the mixing time is 5min to obtain modified butylbenzene Rubber DG2.

On the basis of the total molar weight of vinyl structural units in the described styrene-butadiene rubber forming the modified styrene-butadiene rubber DG2, the grafting rate of the polar modifier is 7mol%, and the gelation rate of the modified styrene-butadiene rubber DG1 is The gum content was 15% by weight.

The formula of the rubber composition of this comparative example is: modified styrene-butadiene rubber DG2 is 100 parts by weight, white carbon black 100 parts by weight, TDAE (softening agent) 8 parts by weight, zinc oxide 5 parts by weight, stearic acid 3 parts by weight , 3 parts by weight of sulfur (vulcanizing agent), 0.5 parts by weight of TBBS (accelerator), 0.5 parts by weight of D (accelerator), 6 parts by weight of antioxidant 4020 (antiaging agent), 2 parts by weight of PEG4000 (softening agent).

The preparation of vulcanized rubber adopts the same process as in Example 3 to obtain vulcanized rubber sample DS2.

The performance test of the vulcanized rubber sample DS2 is shown in Table 4.

Comparative example 3

In the formula of the rubber composition of this comparative example, except that the rubber matrix is the unmodified styrene-butadiene rubber (being the raw material solution-polymerized styrene-butadiene rubber) used in Preparation Example 3, all the other formulas and processing methods are the same as in Example 3. In the same way, the vulcanized rubber sample DS3 was obtained.

The performance test of the vulcanized rubber sample DS3 is shown in Table 4.

Table 4

It can be seen from the above results that the use of the modified styrene-butadiene rubber provided by the present invention is more conducive to the dispersion of silica, thereby improving the strength of vulcanized rubber, reducing its heat generation, and improving wet skid resistance.

Further, comparing the data of Example 3 with Comparative Example 1, Comparative Example 2 and Comparative Example 3, it can be seen that the vulcanized rubber DS1 prepared by using the same rubber composition formula and preparation method as in Example 3, but using a different rubber matrix , DS2 and DS3 are obviously not as good as vulcanized rubber S3 in performance, such as tear strength will be lower than S3, compression temperature rise is higher than S3, resilience is lower than S3, DIN abrasion is higher than S3; the dynamic mechanical properties of the vulcanized rubber of embodiment 3 show Smaller rolling resistance, better wet skid resistance, and Penny effect data also show that the filler dispersion of vulcanized rubber S3 in Example 3 is significantly better than DS1, DS2 and DS3.

Since the vulcanized rubber of the present invention has better performance, when the vulcanized rubber of the present invention is applied to the tire tread of an automobile, the durability of the tire can be improved, the fuel economy of the automobile can be improved, and the safety of the automobile can be improved.

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 technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the disclosed content of the present invention. All belong to the protection scope of the present invention.

Claims (17)

1. a modified styrene-butadiene rubber, the modified styrene-butadiene rubber is formed by the grafted polar modifier of styrene-butadiene rubber, it is characterized in that, to form the described styrene-butadiene rubber of this modified styrene-butadiene rubber Based on the total molar weight of vinyl structural units, the grafting rate of the polar modifier is 0.5-5 mol%, and the gel content of the modified styrene-butadiene rubber is 3.5-10% by weight, and the polar modifier The property modifier is at least one of the mercapto acid monomers. 2. modified styrene-butadiene rubber according to claim 1, wherein, the mercapto acid monomer is provided by at least one of the compounds shown in formula (1), In formula (1), M is the structure shown in formula (2), x is an integer of 0-3, R ₂ is H or -SH, in formula (2), R ₁ is H or -SH, and , the R ₁ and R ₂ are not H at the same time. 3. The modified styrene-butadiene rubber according to claim 2, wherein, in the mercapto acid monomer, in formula (1), x is ₀ , and R2 is -SH; or x is 1, M is the structure shown in formula (2), R ₁ and R ₂ are each independently H or -SH, and R ₁ and R ₂ are not H at the same time; or x is 2, M is the structure shown in formula (2), R ₂ and R ₁ in the two Ms are each independently H or -SH, and R ₂ and R ₁ in the two Ms are not H at the same time; or x is 3, M is the structure shown in formula (2), R ₂ and R ₁ in the 3 Ms are each independently H or -SH, and R ₂ and R ₁ in the 3 Ms are not H at the same time; Preferably, In the mercapto acid-based monomer, in formula (1), x is 1, M is the structure shown in formula (2), R ₁ and R ₂ are each independently H or -SH, and R ₁ and R ₂ are not H at the same time; or x is 2, M is the structure shown in formula (2), one of the group formed by R ₂ and R ₁ in 2 M is -SH, and the other 2 are H; or x is 3, M is the structure shown in formula (2), one of the group formed by R ₂ and R ₁ in the three Ms is -SH, and the other three are H. 4. The modified styrene-butadiene rubber according to any one of claims 1-3, wherein the content of styrene structural units in the styrene-butadiene rubber is 15 to 30% by weight, and the vinyl content is 30 to 70% by weight , Mooney viscosity is 45-80. 5. A method for preparing modified styrene-butadiene rubber, the method comprising: (1) SBR is carried out mastication, obtains the styrene-butadiene rubber after mastication; (2) Mix the polar modifier with the masticated styrene-butadiene rubber to carry out kneading until the polar modifier in the obtained modified styrene-butadiene rubber is equal to the vinyl group in the styrene-butadiene rubber The graft ratio based on the total molar weight of the structural units is 0.5-5 mol%, and the gel content of the modified styrene-butadiene rubber is 3.5-10% by weight, Wherein, the rotating speed of the described mixing process in the control step (2) is 55～75rpm; And The polar modifier is at least one of the mercapto acid-based monomers, and the amount of the polar modifier is 0.2-1.2 parts by weight relative to 100 parts by weight of the styrene-butadiene rubber. 6. The method according to claim 5, wherein the mercapto acid monomer is provided by at least one of the compounds shown in formula (1), In formula (1), M is the structure shown in formula (2), x is an integer of 0-3, R ₂ is H or -SH, in formula (2), R ₁ is H or -SH, and , the R ₁ and R ₂ are not H at the same time. 7. The method according to claim 6, wherein, in the mercapto acid monomer, in formula (1), x is ₀ , and R2 is -SH; or x is 1, M is the structure shown in formula (2), R ₁ and R ₂ are each independently H or -SH, and R ₁ and R ₂ are not H at the same time; or x is 2, M is the structure shown in formula (2), R ₂ and R ₁ in the two Ms are each independently H or -SH, and R ₂ and R ₁ in the two Ms are not H at the same time; or x is 3, M is the structure shown in formula (2), R ₂ and R ₁ in the 3 Ms are each independently H or -SH, and R ₂ and R ₁ in the 3 Ms are not H at the same time; Preferably, In the mercapto acid-based monomer, in formula (1), x is 1, M is the structure shown in formula (2), R ₁ and R ₂ are each independently H or -SH, and R ₁ and R ₂ are not H at the same time; or x is 2, M is the structure shown in formula (2), one of the group formed by R ₂ and R ₁ in 2 M is -SH, and the other 2 are H; or x is 3, M is the structure shown in formula (2), one of the group formed by R ₂ and R ₁ in the three Ms is -SH, and the other three are H. 8. The method according to any one of claims 5-7, wherein the kneading conditions include: the temperature is 70-130°C, and the time is 1-5min; preferably, The kneading conditions include: the temperature is 90-110° C., and the time is 2-3 minutes. 9 . The method according to claim 5 , wherein the masticating conditions include: a rotating speed of 40-100 rpm, a temperature of 80-120° C., and a time of 0.5-5 min. 10. A rubber composition, containing component A, component B, component C and component D that are kept independently in the composition, said component A is modified styrene-butadiene rubber, and said component B contains white carbon black, the component C contains activator, anti-aging agent, softener and optionally carbon black, and the component D contains accelerator and vulcanizing agent, wherein the modified styrene-butadiene rubber It is the modified styrene-butadiene rubber described in any one of claims 1-4 and/or the modified styrene-butadiene rubber prepared by the method described in any one of claims 5-9. 11. The rubber composition according to claim 10, wherein, relative to 100 parts by weight of the modified styrene-butadiene rubber, the content of the silica is 20 to 120 parts by weight, preferably 50 to 100 parts by weight . 12. The rubber composition according to claim 10, wherein, relative to 100 parts by weight of the modified styrene-butadiene rubber, the content of the activator is 1 to 15 parts by weight, and the content of the antioxidant is 0.5 ～10 parts by weight, the content of the softening agent is 5～30 parts by weight, the content of the carbon black is 0～30 parts by weight, the content of the accelerator is 0.5～10 parts by weight, the content of the vulcanizing agent 0.1 to 5 parts by weight; preferably, With respect to 100 parts by weight of the modified styrene-butadiene rubber, the content of the activator is 3-8 parts by weight, the content of the anti-aging agent is 1-6 parts by weight, and the content of the softener is 10-20 parts by weight. parts by weight, the content of the carbon black is 0-20 parts by weight, the content of the accelerator is 1-6 parts by weight, and the content of the vulcanizing agent is 0.5-3 parts by weight. 13. The rubber composition according to claim 10, wherein the nitrogen adsorption specific surface area of the silica is 10-200 m ² /g; preferably, The activator is a composition of a metal oxide and a fatty acid or a metal soap salt of a fatty acid; preferably, The antioxidant is at least one of amine antioxidants, quinoline antioxidants and benzimidazole antioxidants; preferably, The softening agent is at least one of aromatic oil, paraffin oil, naphthenic oil, petroleum resin and polyethylene glycol; preferably, The CTAB adsorption specific surface area of the carbon black is 10-300m ² /g; preferably, The accelerator is at least one of a sulfenamide accelerator, a thiazole accelerator, a thiuram accelerator and a guanidine accelerator; preferably, The vulcanizing agent is sulfur and/or a sulfur donor. 14. A method of preparing vulcanized rubber, the method comprising: (1) carry out first mixing with the modified styrene-butadiene rubber as component A and component B containing white carbon black, obtain one section of masterbatch; (2) Carrying out second mixing of the one-stage masterbatch with component C containing an activator, an anti-aging agent, a softener and optional carbon black, to obtain a second-stage masterbatch; (3) The second-stage masterbatch is mixed with the component D containing accelerator and vulcanizing agent for the third time to obtain the final compound; (4) vulcanizing the final rubber mix; Wherein, the modified styrene-butadiene rubber is the modified styrene-butadiene rubber described in any one of claims 1-4 and/or the modified styrene-butadiene rubber prepared by the method described in any one of claims 5-9. Styrene butadiene rubber; preferably, With respect to 100 parts by weight of the modified styrene-butadiene rubber, the amount of the activator is 1-15 parts by weight, the amount of the anti-aging agent is 0.5-10 parts by weight, and the amount of the softener is 5-30 parts by weight. parts by weight, the amount of the carbon black is 0 to 30 parts by weight, the amount of the accelerator is 0.5 to 10 parts by weight, and the amount of the vulcanizing agent is 0.1 to 5 parts by weight; preferably, With respect to 100 parts by weight of the modified styrene-butadiene rubber, the amount of the activator is 3-8 parts by weight, the amount of the anti-aging agent is 1-6 parts by weight, and the amount of the softener is 10-20 parts by weight. parts by weight, the amount of the carbon black is 0-20 parts by weight, the amount of the accelerator is 1-6 parts by weight, and the amount of the vulcanizing agent is 0.5-3 parts by weight. 15. The method according to claim 14, wherein the first kneading conditions include: the temperature is 100-150° C., and the time is 3-10 min; preferably, the first kneading conditions include: The temperature is 110-120°C, and the time is 5-7 minutes; The conditions for the second mixing include: the temperature is 80-140°C, and the time is 3-12 minutes; preferably, the conditions for the second mixing include: the temperature is 110-130°C, and the time is 3-5 minutes; The conditions for the third mixing include: the temperature is no more than 130°C, and the time is 5-7 minutes; The conditions for the vulcanization include: the temperature is 150-170° C., the pressure is 10-20 MPa, and the time is 30-50 minutes. 16. Vulcanizate prepared by the method of any one of claims 14-15. 17. Use of the vulcanized rubber as claimed in claim 16 in tire treads.