EV pure electric vehicle tread rubber with excellent winter performance and preparation process thereof

Abstract

The invention discloses EV pure electric vehicle tread rubber with excellent winter performance. The EV pure electric vehicle tread rubber is prepared from butadiene rubber 9390, special solution polymerized styrene-butadiene rubber, white carbon black 7000Gr, white carbon black 200MP, modified white carbon black R320U, an active agent ZnO, an active agent SA, an anti-aging agent, modified resin SM100, modified resin PR383, a silane coupling agent Si75, a processing agent UF700S, a vulcanizing agent S-325, an accelerant NS and an accelerant DPG. The invention also discloses a method for preparing the EV pure electric vehicle tread rubber with excellent winter performance. By means of the mode, the tire fabric prepared through the method has higher abrasion resistance, ultralow rolling resistance and electricity saving performance, meanwhile, the service life of a tire is effectively prolonged, and the comprehensive performance is excellent.

Description

Technical Field

[0001] The present invention relates to the technical field of tread rubbers, and in particular to an EV pure electric vehicle tread rubber with excellent winter performance and a preparation process thereof. Background Art

[0002] EV pure electric vehicles have a heavy load, high power consumption when driving at high speeds, long braking distance, and fast starting speed. Therefore, the tire carcass of EV pure electric vehicles is usually required to have low rolling resistance in pursuit of high endurance. To achieve low rolling resistance performance of tires, manufacturers mainly tend to use pure white carbon black formula tread rubber system, such as a combination of natural rubber and solution polymerized styrene butadiene rubber, with ordinary petroleum resin, processing oil, antioxidants, etc.

[0003] Based on the above market research, in terms of components, due to the high Tg point and weak dispersion and modification of silica, the winter performance or wear performance of the above-mentioned pure silica combined with solution polystyrene butadiene rubber system is not very good; at the same time, the Tg point of ordinary petroleum resin used as a softener or the Tg point of processing oil is high and cannot meet the winter driving needs; in terms of preparation process, ordinary rubber processing technology generally puts all raw materials into the first stage of gluing, and controls the temperature and time of gluing to refine the rubber until it reaches a certain temperature within a certain period of time and then discharges the material. In its gluing process, due to the general dispersibility of silica and the insufficient silanization reaction, the rubber will have poor dispersion and affect the wear performance. In addition, the addition of antioxidants in the mixing stage will also affect the silanization reaction, thereby affecting the dispersibility. Summary of the invention

[0004] The main technical problem solved by the present invention is to provide an EV pure electric vehicle tread rubber with excellent winter performance and its preparation process by studying the modification of styrene-butadiene rubber, white carbon black and petroleum resin of different types and proportions and optimizing the rubber application process.

[0005] In order to solve the above technical problems, a technical solution adopted by the present invention is: to provide an EV pure electric vehicle tread rubber with excellent winter performance, the raw material components of the EV pure electric vehicle tread rubber with excellent winter performance include butadiene rubber 9390, special solution-polymerized styrene-butadiene rubber, silica 7000Gr, silica 200MP, modified silica R320U, activator ZnO, activator SA, antioxidant, modified resin SM100, modified resin PR383, silane coupling agent Si75, processing aid UF700S, vulcanizing agent S-325, accelerator NS and accelerator DPG.

[0006] Preferably, the special solution butadiene styrene rubber includes solution butadiene styrene rubber SSBR HPR850R and solution butadiene styrene rubber SOL-6220E, and the usage ratio between the two is between 1:3 and 1:5; according to this technical solution, a formula with a lower Tg point can be obtained to meet winter performance requirements.

[0007] Preferably, the styrene content in the solution polymerized styrene butadiene rubber SOL-6220E is as low as 24.5%, and the vinyl content is as low as 24%; according to this technical scheme, on the one hand, its Tg point can be guided as low as -50°C; the styrene content in the solution polymerized styrene butadiene rubber SSBRHPR850R is between 26% and 29%, and the vinyl content is between 57% and 61%. According to this technical scheme, as the styrene content increases, the glass transition temperature of the raw rubber increases, the thermoplasticity of the rubber increases, the tensile strength increases, and the resilience decreases, which can effectively improve the physical and mechanical properties of the rubber.

[0008] Preferably, the vinyl content of the butadiene rubber BR9390 is between 11% and 15%. According to this technical solution, as the vinyl content increases, the dispersion of white carbon black can be improved, so that the rolling resistance of the formula is lower.

[0009] Preferably, the ratio of the special solution-polymerized styrene-butadiene rubber to the butadiene rubber 9390 is between 1:6 and 1:4; according to this technical solution, the dispersion of silica can be better and the rolling resistance can be better while maintaining the wear resistance.

[0010] Preferably, the modified resin SM100 is a hydrogenated polystyrene resin, which is obtained by hydrogenating polystyrene and hydrogenating the phenyl groups on the chain; according to this technical solution, the modified resin has a rigid benzene ring structure and vinyl macromolecules, which increases the hysteresis loss while maintaining a certain modulus, can better balance the grip and rolling resistance, and at the same time, its heat resistance, oxygen resistance, tensile strength and other properties are greatly improved.

[0011] Preferably, the modified resin PR383 is a hydrogenated copolymer petroleum resin, which is obtained by using a catalyst to cause hydrogen to react with unsaturated double bonds in the polymer chain of the petroleum resin to undergo a hydrogenation reaction, thereby converting unsaturated hydrocarbons into saturated hydrocarbons. According to this technical solution, the modified resin PR383 anti-skid resin has better compatibility with solution-polymerized styrene-butadiene rubber. It contains a rigid benzene ring structure and cyclopentadiene macromolecules. On icy and rainy roads, cyclopentadiene can provide a larger deformation, thereby increasing the contact area between the tire and the ground, reducing the intermolecular force and producing a lubricating effect, making it easy for the molecular chains to slide, and can solve the shortcoming of poor processing operability of styrene-butadiene rubber due to the increase in vinyl content, and can effectively improve the dispersibility of the rubber compound, so that the rubber compound has better winter performance and better quality.

[0012] Preferably, the modified white carbon black R320U is an ultrafine silicon dioxide powder, which is mainly composed of a three-dimensional network structure formed by silicon atoms and oxygen atoms through covalent bonds; according to this technical solution, its chemical properties are stable, and the product stability and performance can be improved.

[0013] Preferably, a tread rubber for an EV pure electric vehicle with excellent winter performance comprises raw materials in weight percentages of 6-11% of cis-butadiene rubber BR9390, 6-11% of styrene-butadiene rubber SSBR HPR850R, 29-31% of styrene-butadiene rubber SOL-6220E, 12-17% of white carbon black 7000Gr, 12-17% of white carbon black 200MP, 4-11% of modified white carbon black R320U, 0.6-0.9% of active agent ZnO, 0.2-0.5% of active agent SA, 2-3% of antioxidant, 2-6% of modified resin SM100, 1.5-6.5% of modified resin PR383, 2-3.5% of silane coupling agent Si75, 0.9-1.5% of processing aid UF700S, 0.5-1.5% of vulcanizing agent S-325, and accelerator NS 0.5~1.5%, accelerator DPG 0.4~0.8%, the sum of the contents of each component is 100%.

[0014] In order to solve the above technical problems, another technical solution adopted by the present invention is: to provide a method for preparing a tread rubber for an EV pure electric vehicle with excellent winter performance, comprising the following preparation steps:

[0015] (1) Mixing stage: cis-butadiene rubber 9390, special solution polymerized styrene-butadiene rubber, white carbon black 7000Gr, white carbon black 200MP, activator SA, modified resin SM100, modified resin PR383, silane coupling agent Si75, accelerator DPG and processing aid UF700S are added to an internal mixer according to the above mass percentages, and the rotor in the internal mixer rotates to drive the rubber materials to mix, and at the same time, a weight is pressed to improve the mixing effect; during the mixing stage, when the temperature of the rubber materials in the internal mixer is 120°C, 135°C, and 145°C, respectively, the weight is lifted, and then the weight is pressed down when the rubber temperature is 145°C, and the mixing is kept constant at 145°C for 100 seconds, and the materials are discharged after the mixing is completed;

[0016] (2) Refining stage: Add modified silica R320U, activator ZnO and antioxidant to the mixed rubber obtained in the mixing stage, raise the temperature of the rubber in the mixing stage by hammering, and keep the mixing at 145°C for 100 seconds. After refining, discharge the material;

[0017] (3) Two-stage pure refining stage: the mixed rubber obtained in the refining stage is further subjected to conventional sizing. This pure refining stage includes two equal stages, and the material is discharged after the pure refining is completed;

[0018] (4) Acceleration stage: Add vulcanizing agent S-325 and accelerator NS to the rubber mixture completed in the two pure refining stages. During the subsequent refining process, the weight is lifted every 30 seconds. When the temperature reaches 105°C, the final refining is completed, and the rubber obtained by discharge is the product of the present invention.

[0019] The beneficial effects of the present invention are:

[0020] Based on the drawbacks of the prior art, the present invention develops different types of styrene-butadiene rubber, white carbon black, petroleum resin and other ingredients, modifies and proportions them, and develops a rubber formula with low Tg point and good wear resistance. The present invention also optimizes the feeding sequence, adds white carbon black and carbon black separately, and adds antioxidant and zinc oxide in the refining stage, which can improve the dispersibility of the rubber and enhance the wear resistance of the rubber. The present invention can meet the requirements of EV pure electric vehicle tires for higher wear resistance, ultra-low rolling resistance and power saving performance, improve the service life of tires, and have excellent comprehensive performance, and overcome the drawbacks of poor tread wear, poor ice and snow performance, aging cracking and other common high white carbon black treads in the prior art, and has good market prospects and technical promotion value. DETAILED DESCRIPTION

[0021] The preferred embodiments of the present invention are described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0022] Embodiment 1:

[0023] Raw material components (parts by weight): 20 parts of cis-1,4-dimethyl-1-butadiene rubber (BR9390), 20 parts of solution-polymerized butadiene styrene rubber (HPR850, with a styrene content of approximately 27.5% and a vinyl content of approximately 59%), 75 parts of solution-polymerized butadiene styrene rubber (SOL-6220E), 35 parts of white carbon black (7000Gr), 35 parts of white carbon black (200MP), 20 parts of modified white carbon black (R320U), 7.2 parts of coupling agent (SI75), 2.8 parts of activator (1.9 parts of ZNO, 0.9 parts of SA), 6.6 parts of antioxidant (2.5 parts of 6PPD, 2 parts of RD, 2.1 parts of 0355), 20 parts of modified resin (5 parts of PR383, 15 parts of SM100), 3 parts of processing aid (UF700S), 2.5 parts of vulcanizing agent (S-325), 2.2 parts of accelerator (NS), and 1.5 parts of accelerator (DPG).

[0024] Embodiment 2:

[0025] Raw material components (parts by weight): 15 parts of cis-1,4-dibutyl rubber (BR9390), 25 parts of solution-polymerized butadiene rubber (HPR850, with a styrene content of approximately 27.5% and a vinyl content of approximately 59%), 75 parts of solution-polymerized butadiene rubber (SOL-6220E), 40 parts of highly dispersed silica (7000Gr), 40 parts of silica (200MP), 10 parts of modified silica (R320U), 8 parts of coupling agent (SI75), 2.4 parts of activator (1.7 parts of ZNO, 0.7 parts of SA), 6 parts of antioxidant (2.3 parts of 6PPD, 1.8 parts of RD, 1.9 parts of 0355), 20 parts of modified resin (10 parts of PR383, 10 parts of SM100), 2.8 parts of processing aid (UF700S), 2.3 parts of vulcanizing agent (S-325), 2 parts of accelerator (NS), and 1.3 parts of accelerator (DPG).

[0026] Embodiment 3:

[0027] Raw material components (parts by weight): 25 parts of cis-1,4-dimethyl-1-butadiene rubber (BR9390), 15 parts of solution-polymerized butadiene styrene rubber (HPR850, with a styrene content of approximately 27.5% and a vinyl content of approximately 59%), 75 parts of solution-polymerized butadiene styrene rubber (SOL-6220E), 30 parts of highly dispersed silica (7000Gr), 30 parts of silica (200MP), 25 parts of modified silica (R320U), 6 parts of coupling agent (SI75), 3.2 parts of activator (2.1 parts of ZNO, 1.1 parts of SA), 7.2 parts of antioxidant (2.7 parts of 6PPD, 2.2 parts of RD, 2.3 parts of 0355), 20 parts of modified resin (15 parts of PR383, 5 parts of SM100), 3.2 parts of processing aid (UF700S), 2.7 parts of vulcanizing agent (S-325), 2.4 parts of accelerator (NS), and 1.7 parts of accelerator (DPG).

[0028] Comparative example: pure white carbon black rubber

[0029] Raw material components (parts by weight): 10 parts of natural rubber (KNR20), 23.4 parts of styrene butadiene rubber (NS522), 73 parts of styrene butadiene rubber (SSBR-2466), 60 parts of highly dispersed silica (7000Gr), 5.7 parts of processing oil (TDAE), 4 parts of coupling agent SI75, 2.8 parts of activator (1.9 parts of ZNO, 0.9 parts of SA), 7.3 parts of antioxidant (2.5 parts of 6PPD, 0.7 parts of 3100, 2 parts of RD, 2.1 parts of 0355), 2 parts of resin HRJ10420, 4.5 parts of processing aid UF700S, 1.8 parts of vulcanizing agent S-325, 2.2 parts of accelerator NS, and 1.5 parts of accelerator DPG.

[0030] The above three groups of embodiments are processed according to the following processing methods:

[0031] (1) Mixing stage: cis-butadiene rubber 9390, special solution polymerized styrene-butadiene rubber, white carbon black 7000Gr, white carbon black 200MP, activator SA, modified resin SM100, modified resin PR383, silane coupling agent Si75, accelerator DPG and processing aid UF700S are added to an internal mixer according to mass percentage, and the rotor in the internal mixer rotates to drive the rubber to mix, and the weight hammer presses the material to improve the mixing effect; during the mixing stage, when the temperature of the rubber in the internal mixer is 120°C, 135°C and 145°C respectively, the weight hammer is lifted, and then the weight hammer is pressed down when the rubber temperature is 145°C, and the mixing is kept constant at 145°C for 100 seconds, and the material is discharged after the mixing is completed;

[0032] (2) Refining stage: Add modified silica R320U, activator ZnO and antioxidant to the mixed rubber obtained in the mixing stage, raise the temperature of the rubber in the mixing stage by hammering, and keep the mixing at 145°C for 100 seconds. After refining, discharge the material;

[0033] (3) Two-stage pure refining stage: the mixed rubber obtained in the refining stage is further subjected to conventional sizing. This pure refining stage includes two equal stages, and the material is discharged after the pure refining is completed;

[0034] (4) Acceleration stage: Add vulcanizing agent S-325 and accelerator NS to the rubber mixture completed in the two pure refining stages. During the subsequent refining process, the weight is lifted every 30 seconds. When the temperature reaches 105°C, the final refining is completed, and the rubber obtained by discharge is the product of the present invention.

[0035] The above comparative example is processed by referring to the processing method of the example, except that: highly dispersed silica 7000Gr, activator, antioxidant and accelerator DPG are all added in the mixing stage, and vulcanizing agent S-325 and accelerator NS are added in the accelerating stage.

[0036] The performance of the rubber materials obtained from the above three groups of examples and one group of comparative examples was tested under the same conditions, as shown in the following Table 1:

[0037] Table 1: Main technical indicators

[0038]

[0039]

[0040]

[0041]

[0042]

[0043] It can be intuitively seen from the above comparative data that: while maintaining the elongation and tear strength of the rubber material, the rubber material prepared by the present invention has significantly improved hardness, M300 tensile strength, and tensile strength, and the wear resistance is significantly improved, and the winter performance is significantly improved; therefore, the tread rubber obtained according to the present invention is used for tires, which can make trams have very safe driving conditions, greatly improve the life of the tires, maintain ultra-low rolling resistance, so that it has more outstanding power-saving performance, is particularly suitable for winter environments, and has very good product performance advantages.

[0044] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A tread rubber for an EV pure electric vehicle with excellent winter performance, characterized by: The raw materials of the EV pure electric vehicle tread rubber with excellent winter performance include butadiene rubber 9390, special solution-polymerized styrene-butadiene rubber, silica 7000Gr, silica 200MP, modified silica R320U, activator ZnO, activator SA, antioxidant, modified resin SM100, modified resin PR383, silane coupling agent Si75, processing aid UF700S, vulcanizing agent S-325, accelerator NS and accelerator DPG.

2. The tread rubber for an EV pure electric vehicle with excellent winter performance according to claim 1, characterized in that: The special solution polymerized styrene butadiene rubber comprises solution polymerized styrene butadiene rubber SSBR HPR850R and solution polymerized styrene butadiene rubber SOL-6220E, and the usage ratio between the two is between 1:3 and 1:

5.

3. The tread rubber for an EV pure electric vehicle with excellent winter performance according to claim 2, characterized in that: The styrene content of the solution polymerized styrene butadiene rubber SOL-6220E is as low as 24.5%, and the vinyl content is as low as 24%. The styrene content of the solution polymerized styrene butadiene rubber SSBR HPR850R is between 26% and 29%, and the vinyl content is between 57% and 61%.

4. The tread rubber for an EV pure electric vehicle with excellent winter performance according to claim 1, characterized in that: The vinyl content of the butadiene rubber BR9390 is between 11% and 15%.

5. The tread rubber for an EV pure electric vehicle with excellent winter performance according to claim 1, characterized in that: The ratio of the special solution-polymerized styrene-butadiene rubber to the butadiene rubber 9390 is between 1:6 and 1:

4.

6. The tread rubber for an EV pure electric vehicle with excellent winter performance according to claim 1, characterized in that: The modified resin SM100 is a hydrogenated polystyrene resin, which is obtained by hydrogenating polystyrene and adding hydrogen to the phenyl groups on the chain.

7. The tread rubber for an EV pure electric vehicle with excellent winter performance according to claim 1, characterized in that: The modified resin PR383 is a hydrogenated copolymer petroleum resin, which is obtained by using a catalyst to cause hydrogen to react with unsaturated double bonds in the polymer chain of the petroleum resin to undergo a hydrogenation reaction, thereby converting unsaturated hydrocarbons into saturated hydrocarbons.

8. The tread rubber for an EV pure electric vehicle with excellent winter performance according to claim 1, characterized in that: The modified white carbon black R320U is an ultrafine silicon dioxide powder, which mainly has a three-dimensional network structure formed by covalent bonds between silicon atoms and oxygen atoms.

9. The tread rubber for an EV pure electric vehicle with excellent winter performance according to claim 2, characterized in that: The weight percentages of the raw materials are as follows: 6-11% of cis-butadiene rubber BR9390, 6-11% of styrene-butadiene rubber SSBR HPR850R, 29-31% of styrene-butadiene rubber SOL-6220E, 12-17% of white carbon black 7000Gr, 12-17% of white carbon black 200MP, 4-11% of modified white carbon black R320U, 0.6-0.9% of active agent ZnO, 0.2-0.5% of active agent SA, 2-3% of antioxidant, 2-6% of modified resin SM100, 1.5-6.5% of modified resin PR383, 2-3.5% of silane coupling agent Si75, 0.9-1.5% of processing aid UF700S, 0.5-1.5% of vulcanizing agent S-325, 0.5-1.5% of accelerator NS, and accelerator DPG. 0.4~0.8%, the sum of the contents of each component is 100%.

10. A method for preparing the EV pure electric vehicle tread rubber with excellent winter performance as claimed in any of claims 1 to 9, characterized in that: The method comprises the following preparation steps: (1) Mixing stage: cis-butadiene rubber 9390, special solution polymerized styrene-butadiene rubber, white carbon black 7000Gr, white carbon black 200MP, activator SA, modified resin SM100, modified resin PR383, silane coupling agent Si75, accelerator DPG and processing aid UF700S are added to an internal mixer according to the above mass percentages, and the rotor in the internal mixer rotates to drive the rubber materials to mix, and at the same time, a weight is pressed to improve the mixing effect; during the mixing stage, when the temperature of the rubber materials in the internal mixer is 120°C, 135°C, and 145°C, respectively, the weight is lifted, and then the weight is pressed down when the rubber temperature is 145°C, and the mixing is kept constant at 145°C for 100 seconds, and the materials are discharged after the mixing is completed; (2) Refining stage: Add modified silica R320U, activator ZnO and antioxidant to the mixed rubber obtained in the mixing stage, raise the temperature of the rubber in the mixing stage by hammering, and keep the mixing at 145°C for 100 seconds. After refining, discharge the material; (3) Two-stage pure refining stage: the mixed rubber obtained in the refining stage is further subjected to conventional sizing. This pure refining stage includes two equal stages, and the material is discharged after the pure refining is completed; (4) Acceleration stage: Add vulcanizing agent S-325 and accelerator NS to the rubber mixture completed in the two pure refining stages. During the subsequent refining process, the weight is lifted every 30 seconds. When the temperature reaches 105°C, the final refining is completed, and the rubber obtained by discharge is the product of the present invention.

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