Automobile sealing strip rubber material, preparation method and automobile sealing strip

Abstract

The invention discloses a rubber material for automobile sealing strips, a preparation method and automobile sealing strips, and relates to the technical field of automobile sealing strips. The raw materials of the automobile sealing strips include 90-110 parts of modified chloroprene rubber, 5-8 parts of stearic acid, 15-20 parts of modified carbon black, 5-7 parts of modified graphene oxide, 7-10 parts of polyester resin, 2-5 parts of plasticizer, 4-6 parts of filler, 1-3 parts of antioxidant, 1-3 parts of flame retardant, 5-8 parts of accelerator and 2-4 parts of crosslinking agent by weight. The whole production cost is reduced, and the obtained sealing strip has better flame retardancy, sealing property and structural stability.

Description

Technical Field

[0001] The invention relates to the technical field of automobile sealing strips, and in particular to an automobile sealing strip rubber material, a preparation method and an automobile sealing strip. Background Art

[0002] An important indicator of the quality of a whole vehicle is sealing, and automobile sealing strip products are one of the important parts that determine the quality of this indicator. Automobile sealing strips are widely used in front and rear windshields, doors, windows, seats, sunroofs, engine compartments, trunks and other parts of the car body. In addition to the functions of sealing, shock absorption, waterproofing, dustproofing, sound insulation, and decoration, they also fill the gaps between body parts and make up for assembly errors, protecting and maintaining the driver and the whole vehicle. As the car is affected by the external environment throughout the year, the automobile sealing strip is often prone to deformation and aging due to high temperature, low temperature, strong light exposure and corrosion in harsh environments, which seriously affects the sealing performance, shock absorption performance and service life of the sealing strip, and thus affects the safety of the car. It is not only a consumable item among auto parts, but also an unstable factor affecting the safety of car use.

[0003] Chinese patent CN106905620B discloses an automobile sealing strip rubber material and an automobile sealing strip, which have extremely excellent sealing performance, tolerance performance, compression deformation resistance and mechanical properties, and greatly improve the performance and service life of the automobile sealing strip.

[0004] Chinese patent CN118063899B discloses a lightweight automotive sealing strip and its production process, which not only has excellent flame retardant properties and meets the requirements of lightweight, but also has a certain improvement in tensile strength. On the other hand, the flame retardant group can play a role for a long time, and even after washing and friction treatment, it can still show excellent flame retardant effect.

[0005] At present, most automotive sealing strips use EPDM rubber as the main raw material. EPDM rubber has excellent ozone resistance, heat resistance and aging resistance. However, the relatively high price of EPDM rubber leads to high production costs of sealing strips. At the same time, the limiting oxygen index of the original EPDM material of EPDM rubber is only 17.8%, and its flame retardancy is poor. After long-term use, it is prone to compression deformation, resulting in obvious holes in the sealing strip. In addition, the adhesion with fabrics and metals is poor, affecting the overall structural stability of the sealing strip. Summary of the invention

[0006] The first technical problem to be solved by the present invention is: in view of the deficiencies in the prior art, a rubber material for automobile sealing strips is provided, which has low production cost and produces sealing strips with good flame retardancy, strong sealing performance and good structural stability.

[0007] To solve the above-mentioned first technical problem, the technical solution of the present invention is:

[0008] A rubber material for automobile sealing strips. The raw materials of the automobile sealing strips include, by weight: 90-110 parts of modified chloroprene rubber, 5-8 parts of stearic acid, 15-20 parts of modified carbon black, 5-7 parts of modified graphene oxide, 7-10 parts of polyester resin, 2-5 parts of plasticizer, 4-6 parts of filler, 1-3 parts of antioxidant, 1-3 parts of flame retardant, 5-8 parts of accelerator and 2-4 parts of cross-linking agent.

[0009] Preferably, the chloroprene rubber is modified chloroprene rubber, and the preparation method of the modified chloroprene rubber is:

[0010] The chloroprene rubber is dissolved in toluene, and then ethylene-vinyl acetate copolymer and N, N-methylenebisacrylamide are added thereto, stirred evenly, the pH of the solution is adjusted to neutral, and then dibenzoyl peroxide is added, and the polymerization reaction is carried out at 55-70° C. for 2-4 hours. After the reaction is completed, the toluene is evaporated by heating, and the obtained solid is washed with deionized water and dried to obtain the modified chloroprene rubber;

[0011] Wherein, the amount of N,N-methylenebisacrylamide added is 0.05-0.1% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0012] The amount of dibenzoyl peroxide added is 0.05-0.1% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0013] The mass ratio of chloroprene rubber to ethylene-vinyl acetate copolymer is 8-12:6-10.

[0014] Preferably, the carbon black is modified carbon black, and the preparation method of the modified carbon black is:

[0015] Add carbon black into nitric acid solution, react at 90-100°C for 3-5h, rinse the reaction product with deionized water, and dry at 60-70°C for 1-3h to obtain modified carbon black;

[0016] The concentration of the nitric acid solution is 1-5%wt, and the ratio of the added amount of carbon black to the nitric acid solution is 1:5-10g / mL.

[0017] Preferably, the graphene oxide is modified graphene oxide, and the preparation method of the modified graphene oxide is:

[0018] Pre-treat natural graphite powder, add the pre-treated natural graphite powder into a reaction container, add perchloric acid and potassium permanganate into the reaction container, react at 20-30° C. for 1-2 hours, heat to 38° C. and continue stirring for 20-30 minutes, rinse with deionized water until the filtrate is neutral, and dry the obtained solid in a vacuum drying oven for 2-3 hours to obtain modified graphene oxide;

[0019] The mass ratio of the pretreated natural graphite powder to perchloric acid and potassium permanganate is 1:1-2:2-3.

[0020] Preferably, the flame retardant is a phosphorus-based flame retardant or a silicon-based flame retardant.

[0021] Preferably, the accelerator is a mixture of 2-mercaptobenzimidazole and N,N-dicyclohexyl-2-benzothiazolesulfenamide, wherein the mass ratio of 2-mercaptobenzimidazole to N,N-dicyclohexyl-2-benzothiazolesulfenamide is 1:3-4.

[0022] Preferably, the filler is a mixture of heavy magnesium carbonate and cellulose, wherein the mass ratio of heavy magnesium carbonate to cellulose is 1:1-1.5;

[0023] The plasticizer is one of naphthenic mineral oil and naphthenic oil.

[0024] Preferably, the cross-linking agent is one of zinc oxide and magnesium oxide;

[0025] The polyester resin is a polyester resin containing a benzene ring structure;

[0026] The antioxidant is one of aromatic amine antioxidants, hindered phenol antioxidants or a mixture thereof.

[0027] The second technical problem to be solved by the present invention is: in view of the shortcomings of the prior art, a method for preparing an automobile sealing strip rubber material is provided, which has low production cost and the prepared sealing strip has good flame retardancy, strong sealing performance and good structural stability.

[0028] To solve the above second technical problem, the technical solution of the present invention is:

[0029] A method for preparing a rubber material for automobile sealing strips comprises the following steps:

[0030] S1, modified chloroprene rubber and stearic acid are placed in an internal mixer and mixed at 120-130°C for 15-20 minutes;

[0031] S2, then add accelerator, crosslinking agent, antioxidant, plasticizer and flame retardant, and continue mixing at 150-160°C for 10-20 minutes;

[0032] S3. Finally, add polyester resin, modified carbon black, modified graphene oxide and filler, mix at 180-210° C. for 15-20 min to obtain the automotive sealing strip rubber material.

[0033] The third technical problem to be solved by the present invention is: in view of the deficiencies in the prior art, to provide an automobile sealing strip with good flame retardancy, strong sealing performance and good structural stability.

[0034] To solve the third technical problem, the technical solution of the present invention is:

[0035] An automobile sealing strip comprises a main body structure made of an automobile sealing strip rubber material and a film structure of a thermoplastic polyurethane film wrapped around the outer periphery of the main body structure.

[0036] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0037] 1. Using lower-priced chloroprene rubber as the main raw material reduces the overall production cost, and the resulting sealing strip has better flame retardancy, sealing and structural stability.

[0038] 2. Chloroprene rubber contains chlorine atom groups with strong polarity, which are easy to harden and lose elasticity at low temperatures, resulting in poor processing performance, poor viscosity during molding, and poor compatibility when blended with other raw materials. The present invention cross-links chloroprene rubber into a three-dimensional network structure by adding N, N-methylenebisacrylamide, greatly improving the strength, heat resistance, wear resistance and other properties of the material, and then adds dibenzoyl peroxide to allow chloroprene rubber and ethylene-vinyl acetate copolymer to undergo graft polymerization. The addition of ethylene-vinyl acetate copolymer greatly improves the vulcanization activity of chloroprene rubber, and its wear resistance, tear resistance, flexibility and impact resistance are significantly improved. Ethylene-vinyl acetate copolymer, as a green and environmentally friendly material, does not contain toxic substances, so the grafted chloroprene rubber also has this advantage and is safer.

[0039] 3. Ethylene-vinyl acetate copolymer introduces polar vinyl acetate monomer units, which enhance the interaction between chloroprene rubber and grafted rubber, thereby improving the compatibility of chloroprene rubber after grafting copolymerization. At the same time, the introduction of vinyl acetate monomer units reduces the crystallization ability of the copolymer. Due to the decrease in crystallinity, the distance between polymer chains increases, thereby improving the flexibility and impact resistance of the material. Ethylene-vinyl acetate copolymer has excellent low-temperature resistance, so that the grafted chloroprene rubber can still maintain good processing performance and use performance in low-temperature environments.

[0040] 4. Poor dispersion of carbon black will lead to the decline of performance of rubber products, such as insufficient wear resistance, weather resistance and sealing performance. However, nitric acid treatment can significantly improve the dispersion of carbon black, remove heteroatoms and functional groups on the surface of carbon black through oxidation, and increase oxygen-containing groups such as carbonyl and carboxyl on the surface of carbon black, thereby improving its surface activity, reducing the agglomeration between carbon black particles, thereby improving its dispersion and compatibility with polymers, reducing the amount of carbon black added and improving overall performance, avoiding the situation where the product hardness is too high and its elasticity is damaged due to excessive addition of carbon black. Modified graphene oxide has a larger specific surface area, high thermal stability and good mechanical stability, which enables it to maintain excellent processing performance under high temperature environment. During the mixing process, the modified graphene oxide flakes and the modified carbon black particles are isolated from each other, which can not only hinder the secondary aggregation of graphene oxide, but also further enhance the dispersion effect of carbon black, which helps to improve the overall performance of the composite material. The synergistic effect of modified carbon black and modified graphene oxide not only improves the overall dispersibility of the rubber, reduces the porosity of the rubber, but also enhances the interface bonding between the two and the rubber matrix, thereby improving the mechanical properties of the composite material, and the strength and elasticity of the rubber are greatly improved.

[0041] 5. Potassium permanganate, as a strong oxidant, performs edge oxidation on graphite powder in an acidic environment, introducing oxygen-containing functional groups such as hydroxyl, carboxyl and carbonyl. This edge oxidation modification can improve the stability and dispersibility of graphene in the later processing. In addition, edge oxidation can improve the hardness of graphene oxide and the wear resistance of the obtained automotive sealing strip rubber.

[0042] 6. Polyester resin has good adhesion, which is beneficial to the bonding and molding of various raw materials, and at the same time improves the tensile strength of the rubber; stearic acid can play a lubricating role, which helps to improve the processing performance of chloroprene rubber and make the product easier to mold.

[0043] 7. Heavy magnesium carbonate can improve the mechanical strength, heat resistance and wear resistance of the sealing strip, thereby extending the service life of the product. In addition, it also has certain flame retardant properties; while cellulose has excellent temperature resistance, pressure resistance and barrier properties. The synergistic use of the two improves the physical properties and sealing effect of the automotive sealing strip.

[0044] 8. Plasticizers increase the flexibility and plasticity of materials such as chloroprene rubber, making the sealing strip easier to shape during processing, and the finished product has better softness and elasticity; 2-mercaptobenzimidazole and N,N-dicyclohexyl-2-benzothiazolesulfonamide not only shorten the vulcanization time of chloroprene rubber and improve production efficiency, but also increase the hardness and durability of the sealing strip. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the embodiments. Example 1

[0046] A rubber material for automobile sealing strips. The raw materials for the automobile sealing strips include, by weight, 90 parts of chloroprene rubber, 5 parts of stearic acid, 15 parts of carbon black, 5 parts of graphene oxide, 7 parts of polyester resin, 2 parts of plasticizer, 4 parts of filler, 1 part of antioxidant, 1 part of flame retardant, 5 parts of accelerator, and 2 parts of cross-linking agent.

[0047] The chloroprene rubber is modified chloroprene rubber, and the preparation method of the modified chloroprene rubber is:

[0048] The chloroprene rubber is dissolved in toluene, and then ethylene-vinyl acetate copolymer and N, N-methylenebisacrylamide are added thereto, stirred evenly, the pH value of the solution is adjusted to neutral, and then dibenzoyl peroxide is added, and the polymerization reaction is carried out at 55° C. for 2 hours. After the reaction is completed, the toluene is evaporated by heating, and the obtained solid is washed with deionized water and dried to obtain the modified chloroprene rubber;

[0049] Wherein, the amount of N,N-methylenebisacrylamide added is 0.05% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0050] The amount of dibenzoyl peroxide added is 0.05% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0051] The mass ratio of chloroprene rubber to ethylene-vinyl acetate copolymer is 8:5.

[0052] The carbon black is modified carbon black, and the preparation method of the modified carbon black is:

[0053] Carbon black N550 was added into nitric acid solution, reacted at 90°C for 3h, the reaction product was washed with deionized water, and dried at 60°C for 1h to obtain modified carbon black;

[0054] The concentration of the nitric acid solution is 1%wt, and the ratio of the added amount of carbon black to the nitric acid solution is 1:5g / mL.

[0055] The graphene oxide is modified graphene oxide, and the preparation method of the modified graphene oxide is:

[0056] Pre-treat natural graphite powder, add the pre-treated natural graphite powder into a reaction container, add perchloric acid and potassium permanganate into the reaction container, react at 20°C for 1 hour, heat to 38°C and continue stirring for 20 minutes, rinse with deionized water until the filtrate is neutral, and dry the obtained solid in a vacuum drying oven for 2 hours to obtain modified graphene oxide;

[0057] Among them, the mass ratio of the pretreated natural graphite powder to perchloric acid and potassium permanganate is 1:1:2.

[0058] The flame retardant is phosphate ester.

[0059] The accelerator is a mixture of 2-mercaptobenzimidazole and N,N-dicyclohexyl-2-benzothiazole sulfenamide, wherein the mass ratio of 2-mercaptobenzimidazole to N,N-dicyclohexyl-2-benzothiazole sulfenamide is 1:3.

[0060] The filler is a mixture of heavy magnesium carbonate and cellulose, wherein the mass ratio of heavy magnesium carbonate to cellulose is 1:1;

[0061] The plasticizer is naphthenic mineral oil rubber plasticizer N4010;

[0062] The cross-linking agent is zinc oxide;

[0063] The polyester resin is polybutylene terephthalate;

[0064] The antioxidant is hindered phenol antioxidant 1010. Example 2

[0065] A rubber material for automobile sealing strips. The raw materials for the automobile sealing strips include, by weight, 100 parts of chloroprene rubber, 7 parts of stearic acid, 18 parts of carbon black, 6 parts of graphene oxide, 9 parts of polyester resin, 4 parts of plasticizer, 5 parts of filler, 2 parts of antioxidant, 2 parts of flame retardant, 7 parts of accelerator, and 3 parts of cross-linking agent.

[0066] The chloroprene rubber is modified chloroprene rubber, and the preparation method of the modified chloroprene rubber is:

[0067] The chloroprene rubber is dissolved in toluene, and then ethylene-vinyl acetate copolymer and N, N-methylenebisacrylamide are added thereto, stirred evenly, the pH value of the solution is adjusted to neutral, and then dibenzoyl peroxide is added, and the polymerization reaction is carried out at 65° C. for 3 hours. After the reaction is completed, the toluene is evaporated by heating, and the obtained solid is washed with deionized water and dried to obtain the modified chloroprene rubber;

[0068] Wherein, the amount of N,N-methylenebisacrylamide added is 0.07% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0069] The amount of dibenzoyl peroxide added was 0.08% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0070] The mass ratio of chloroprene rubber to ethylene-vinyl acetate copolymer is 1:1.

[0071] The carbon black is modified carbon black, and the preparation method of the modified carbon black is:

[0072] Carbon black N550 was added to a nitric acid solution, reacted at 95°C for 4 hours, the reaction product was washed with deionized water, and dried at 65°C for 2 hours to obtain modified carbon black;

[0073] The concentration of the nitric acid solution is 3%wt, and the ratio of the added amount of carbon black to the nitric acid solution is 1:7g / mL.

[0074] The graphene oxide is modified graphene oxide, and the preparation method of the modified graphene oxide is:

[0075] Pre-treat natural graphite powder, add the pre-treated natural graphite powder into a reaction container, add perchloric acid and potassium permanganate into the reaction container, react at 25° C. for 1.5 h, heat to 38° C. and continue stirring for 25 min, rinse with deionized water until the filtrate is neutral, and dry the obtained solid in a vacuum drying oven for 2.5 h to obtain modified graphene oxide;

[0076] Among them, the mass ratio of the pretreated natural graphite powder to perchloric acid and potassium permanganate is 1:1.5:2.5.

[0077] The flame retardant is a phosphite flame retardant.

[0078] The accelerator is a mixture of 2-mercaptobenzimidazole and N,N-dicyclohexyl-2-benzothiazole sulfenamide, wherein the mass ratio of 2-mercaptobenzimidazole to N,N-dicyclohexyl-2-benzothiazole sulfenamide is 1:3.5.

[0079] The filler is a mixture of heavy magnesium carbonate and cellulose, wherein the mass ratio of heavy magnesium carbonate to cellulose is 1:1.2;

[0080] The plasticizer is naphthenic mineral oil rubber plasticizer N4010.

[0081] The cross-linking agent is zinc oxide;

[0082] The polyester resin is polybutylene terephthalate;

[0083] The antioxidant is hindered phenol antioxidant 1010. Example 3

[0084] A rubber material for automobile sealing strips. The raw materials for the automobile sealing strips include, by weight, 110 parts of chloroprene rubber, 8 parts of stearic acid, 20 parts of carbon black, 7 parts of graphene oxide, 10 parts of polyester resin, 5 parts of plasticizer, 6 parts of filler, 3 parts of antioxidant, 3 parts of flame retardant, 8 parts of accelerator, and 4 parts of cross-linking agent.

[0085] The chloroprene rubber is modified chloroprene rubber, and the preparation method of the modified chloroprene rubber is:

[0086] The chloroprene rubber is dissolved in toluene, and then ethylene-vinyl acetate copolymer and N, N-methylenebisacrylamide are added thereto, stirred evenly, the pH of the solution is adjusted to neutral, and then dibenzoyl peroxide is added, and the polymerization reaction is carried out at 70° C. for 4 hours. After the reaction is completed, the toluene is evaporated by heating, and the obtained solid is washed with deionized water and dried to obtain the modified chloroprene rubber;

[0087] Wherein, the amount of N,N-methylenebisacrylamide added is 0.1% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0088] The amount of dibenzoyl peroxide added was 0.1% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0089] The mass ratio of chloroprene rubber to ethylene-vinyl acetate copolymer is 6:5.

[0090] The carbon black is modified carbon black, and the preparation method of the modified carbon black is:

[0091] Carbon black N660 was added into nitric acid solution, reacted at 100°C for 5 hours, the reaction product was washed with deionized water, and dried at 70°C for 3 hours to obtain modified carbon black;

[0092] The concentration of the nitric acid solution is 5%wt, and the ratio of the added amount of carbon black to the nitric acid solution is 1:10g / mL.

[0093] The graphene oxide is modified graphene oxide, and the preparation method of the modified graphene oxide is:

[0094] Pre-treat natural graphite powder, add the pre-treated natural graphite powder into a reaction container, add perchloric acid and potassium permanganate into the reaction container, react at 30° C. for 2 h, heat to 38° C. and continue stirring for 30 min, rinse with deionized water until the filtrate is neutral, and dry the obtained solid in a vacuum drying oven for 3 h to obtain modified graphene oxide;

[0095] Among them, the mass ratio of pretreated natural graphite powder to perchloric acid and potassium permanganate is 1:2:3.

[0096] The flame retardant is a silicone resin flame retardant, and the specific model is Dow Corning silicone flame retardant FCA-107.

[0097] The accelerator is a mixture of 2-mercaptobenzimidazole and N,N-dicyclohexyl-2-benzothiazole sulfenamide, wherein the mass ratio of 2-mercaptobenzimidazole to N,N-dicyclohexyl-2-benzothiazole sulfenamide is 1:4.

[0098] The filler is a mixture of heavy magnesium carbonate and cellulose, wherein the mass ratio of heavy magnesium carbonate to cellulose is 1:1.5;

[0099] The plasticizer is naphthenic oil 4006.

[0100] The cross-linking agent is magnesium oxide;

[0101] The polyester resin is polybutylene terephthalate;

[0102] The antioxidant is an aromatic amine antioxidant, p-phenylenediamine. Example 4

[0103] A rubber material for automobile sealing strips. The raw materials for the automobile sealing strips include, by weight, 110 parts of chloroprene rubber, 7 parts of stearic acid, 18 parts of carbon black, 7 parts of graphene oxide, 10 parts of polyester resin, 4 parts of plasticizer, 5 parts of filler, 3 parts of antioxidant, 3 parts of flame retardant, 7 parts of accelerator, and 3 parts of cross-linking agent.

[0104] The chloroprene rubber is modified chloroprene rubber, and the preparation method of the modified chloroprene rubber is:

[0105] The chloroprene rubber is dissolved in toluene, and then ethylene-vinyl acetate copolymer and N, N-methylenebisacrylamide are added thereto, stirred evenly, the pH of the solution is adjusted to neutral, and then dibenzoyl peroxide is added, and the polymerization reaction is carried out at 70° C. for 3 hours. After the reaction is completed, the toluene is evaporated by heating, and the obtained solid is washed with deionized water and dried to obtain the modified chloroprene rubber;

[0106] Wherein, the amount of N,N-methylenebisacrylamide added is 0.08% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0107] The amount of dibenzoyl peroxide added was 0.08% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer;

[0108] The mass ratio of chloroprene rubber to ethylene-vinyl acetate copolymer is 12:5.

[0109] The carbon black is modified carbon black, and the preparation method of the modified carbon black is:

[0110] Carbon black N660 was added into nitric acid solution, reacted at 95°C for 5 hours, the reaction product was washed with deionized water, and dried at 70°C for 3 hours to obtain modified carbon black;

[0111] The concentration of the nitric acid solution is 4%wt, and the ratio of the added amount of carbon black to the nitric acid solution is 1:8g / mL.

[0112] The graphene oxide is modified graphene oxide, and the preparation method of the modified graphene oxide is:

[0113] Pre-treat natural graphite powder, add the pre-treated natural graphite powder into a reaction container, add perchloric acid and potassium permanganate into the reaction container, react at 28°C for 1.5h, heat to 38°C and continue stirring for 28min, rinse with deionized water until the filtrate is neutral, and dry the obtained solid in a vacuum drying oven for 3h to obtain modified graphene oxide;

[0114] Among them, the mass ratio of the pretreated natural graphite powder to perchloric acid and potassium permanganate is 1:1.5:2.5.

[0115] The flame retardant is a silicone flame retardant, and the specific model is Dow Corning silicone flame retardant FCA-117.

[0116] The accelerator is a mixture of 2-mercaptobenzimidazole and N,N-dicyclohexyl-2-benzothiazole sulfenamide, wherein the mass ratio of 2-mercaptobenzimidazole to N,N-dicyclohexyl-2-benzothiazole sulfenamide is 1:4.

[0117] The filler is a mixture of heavy magnesium carbonate and cellulose, wherein the mass ratio of heavy magnesium carbonate to cellulose is 1:1.5;

[0118] The plasticizer is naphthenic oil 4006.

[0119] The cross-linking agent is magnesium oxide;

[0120] The polyester resin is polybutylene terephthalate;

[0121] The antioxidant is an aromatic amine antioxidant, p-phenylenediamine. Example 5

[0122] The preparation method of the automobile sealing strip rubber material in Examples 1-4 comprises the following steps:

[0123] S1, modified chloroprene rubber and stearic acid are placed in an internal mixer and mixed at 120-130°C for 15-20 minutes;

[0124] S2, then add accelerator, crosslinking agent, antioxidant, plasticizer and flame retardant, and continue mixing at 150-160°C for 10-20 minutes;

[0125] S3. Finally, add polyester resin, modified carbon black, modified graphene oxide and filler, mix at 180-210° C. for 15-20 min to obtain the automotive sealing strip rubber material. Example 6

[0126] An automobile sealing strip is obtained by extruding the automobile sealing strip rubber materials in embodiments 1 to 5 into sealing strip blanks with specific shapes through an extruder, and then cooling and shaping the blanks to obtain the automobile sealing strips. Comparative Example 1

[0127] The modified chloroprene rubber was replaced by EPDM rubber, and the other conditions were exactly the same as those in Example 3. Comparative Example 2

[0128] No modified carbon black was used, and other conditions were exactly the same as in Example 3. Comparative Example 3

[0129] No modified graphene oxide was used, and other conditions were exactly the same as in Example 3. Comparative Example 4

[0130] No modified carbon black and modified graphene oxide were used, and other conditions were exactly the same as in Example 3. Comparative Example 5

[0131] No polyester resin was used, and other conditions were exactly the same as in Example 3. Comparative Example 6

[0132] No filler was used, and other conditions were exactly the same as in Example 3. Comparative Example 7

[0133] No accelerator was used, and other conditions were exactly the same as in Example 3. Comparative Example 8

[0134] Carbon black N550 was used as the raw material, i.e., the carbon black was not modified, and other conditions were exactly the same as those in Example 3. Comparative Example 9

[0135] Chloroprene rubber was used as the raw material, i.e., the chloroprene rubber was not modified, and other conditions were exactly the same as those in Example 3.

[0136] The performance of the automotive sealing strip rubber materials obtained in Examples 1-4 and Comparative Examples 1-9 was tested, and the results are shown in the following table:

[0137] Table 1

[0138]

[0139] It can be seen from the table that modified carbon black and modified graphene oxide have a great influence on the physical properties of the sealing strip rubber material, especially the synergistic effect of modified carbon black and modified graphene oxide, which greatly improves the elongation at break of the sealing strip rubber material; in addition, the compression permanent deformation of the sealing strip rubber material of the present invention changes little with the increase of time, indicating that the sealing strip rubber material has good stability and a long service life.

[0140] It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

Claims

1. A rubber material for automobile sealing strips, characterized in that: The raw materials of the automobile sealing strip include, by weight: 90-110 parts of modified chloroprene rubber, 5-8 parts of stearic acid, 15-20 parts of modified carbon black, 5-7 parts of modified graphene oxide, 7-10 parts of polyester resin, 2-5 parts of plasticizer, 4-6 parts of filler, 1-3 parts of antioxidant, 1-3 parts of flame retardant, 5-8 parts of accelerator, and 2-4 parts of cross-linking agent; The preparation method of the modified chloroprene rubber is: The chloroprene rubber is dissolved in toluene, and then ethylene-vinyl acetate copolymer and N, N-methylenebisacrylamide are added thereto, stirred evenly, the pH of the solution is adjusted to neutral, and then dibenzoyl peroxide is added, and the polymerization reaction is carried out at 55-70° C. for 2-4 hours. After the reaction is completed, the toluene is evaporated by heating, and the obtained solid is washed with deionized water and dried to obtain the modified chloroprene rubber; Wherein, the amount of N,N-methylenebisacrylamide added is 0.05-0.1% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer; The amount of dibenzoyl peroxide added is 0.05-0.1% w / w of the total amount of chloroprene rubber and ethylene-vinyl acetate copolymer; The mass ratio of chloroprene rubber to ethylene-vinyl acetate copolymer is 8-12:5-10; The preparation method of the modified carbon black is: Add carbon black into nitric acid solution, react at 90-100°C for 3-5h, rinse the reaction product with deionized water, and dry at 60-70°C for 1-3h to obtain modified carbon black; The concentration of the nitric acid solution is 1-5%wt, and the ratio of the amount of carbon black to the amount of the nitric acid solution added is 1:5-10g / mL; The preparation method of the modified graphene oxide is: Pre-treat natural graphite powder, add the pre-treated natural graphite powder into a reaction container, add perchloric acid and potassium permanganate into the reaction container, react at 20-30° C. for 1-2 hours, heat to 38° C. and continue stirring for 20-30 minutes, rinse with deionized water until the filtrate is neutral, and dry the obtained solid in a vacuum drying oven for 2-3 hours to obtain modified graphene oxide; The mass ratio of the pretreated natural graphite powder to perchloric acid and potassium permanganate is 1:1-2:2-3.

2. The rubber material for automobile sealing strips according to claim 1, characterized in that: The flame retardant is one of a phosphorus-based flame retardant and a silicon-based flame retardant.

3. The rubber material for automobile sealing strip according to claim 1, characterized in that: The accelerator is a mixture of 2-mercaptobenzimidazole and N,N-dicyclohexyl-2-benzothiazole sulfenamide, wherein the mass ratio of 2-mercaptobenzimidazole to N,N-dicyclohexyl-2-benzothiazole sulfenamide is 1:3-4.

4. The rubber material for automobile sealing strips according to claim 1, characterized in that: The filler is a mixture of heavy magnesium carbonate and cellulose, wherein the mass ratio of heavy magnesium carbonate to cellulose is 1:1-1.5; The plasticizer is one of naphthenic mineral oil and naphthenic oil.

5. The rubber material for automobile sealing strip according to claim 1, characterized in that: The cross-linking agent is one of zinc oxide and magnesium oxide; The polyester resin is a polyester resin containing a benzene ring structure; The antioxidant is one of aromatic amine antioxidants, hindered phenol antioxidants or a mixture thereof.

6. The method for preparing the rubber material for automobile sealing strips according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, modified chloroprene rubber and stearic acid are placed in an internal mixer and mixed at 120-130°C for 15-20 minutes; S2, then add accelerator, crosslinking agent, antioxidant, plasticizer and flame retardant, and continue mixing at 150-160°C for 10-20 minutes; S3. Finally, add polyester resin, modified carbon black, modified graphene oxide and filler, mix at 180-210° C. for 15-20 min to obtain the automobile sealing strip rubber material.

7. An automobile sealing strip, characterized in that: The invention comprises a main body structure made of the automobile sealing strip rubber material according to any one of claims 1 to 5, and a film structure of a thermoplastic polyurethane film wrapped around the periphery of the main body structure.

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