Heat-resistant and aging-resistant rubber special for automobile inner tube and preparation method of heat-resistant and aging-resistant rubber

Abstract

The invention provides heat-resistant and aging-resistant rubber special for an automobile inner tube and a preparation method of the rubber. The rubber is prepared from the following components in parts by weight: 100 parts of butyl rubber, 8-12 parts of phosphorus-containing polysilazane, 16-20 parts of an isocyanate composition, 10-14 parts of a vulcanizing agent, 30-35 parts of modified filler and 0.2-0.6 part of a silane coupling agent. The phosphorus-containing polysilazane, the isocyanate composition and the modified filler are added into the butyl rubber and vulcanized, and the prepared heat-resistant and aging-resistant rubber special for the automobile inner tube is excellent in comprehensive performance and good in heat resistance and aging resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber materials, and in particular relates to a heat-resistant and aging-resistant special rubber for automobile inner tubes and a preparation method thereof. Background Art

[0002] Butyl rubber is a material made by the copolymerization of isobutylene and isoprene. The main purpose of adding isoprene is to make the polymer contain unsaturated bonds, so that it can be vulcanized with sulfur to enhance its performance and make the application range of butyl rubber wider.

[0003] Butyl rubber inner tube is an inner tube made of butyl rubber. Butyl rubber is a synthetic rubber produced by the polymerization of isobutylene and a small amount of isoprene. It is known for its excellent air tightness, heat resistance, good elasticity, aging resistance and other properties. These characteristics make butyl rubber inner tubes superior to traditional natural rubber inner tubes in terms of air tightness, elasticity and other aspects. However, the thermal conductivity of butyl rubber is low. Under high temperature or long-term high-speed driving, more heat will be generated inside the tire. If this heat cannot be effectively conducted away, it will cause the temperature inside the tire to rise, which may accelerate the aging process of the rubber and affect the service life and safety of the tire.

[0004] In order to improve the thermal conductivity of butyl rubber inner tubes in the prior art, graphene is added during the preparation of butyl rubber to improve its thermal conductivity. However, graphene is a relatively new material with a high production cost. Adding graphene to butyl rubber will significantly increase the production cost of the inner tube and affect the market competitiveness of the product. At the same time, the mechanical properties of butyl rubber are not ideal and cannot meet market demand.

[0005] Therefore, there is an urgent need for a heat-resistant and aging-resistant special rubber for automobile inner tubes and a preparation method thereof. Summary of the invention

[0006] The purpose of the present invention is to provide a heat-resistant and aging-resistant special rubber for automobile inner tubes and a preparation method thereof.

[0007] In order to achieve the above object, the present invention provides the following technical solutions: A heat-resistant and aging-resistant special rubber for automobile inner tubes, comprising the following components in parts by weight: 100 parts of butyl rubber, 8-12 parts of phosphorus-containing polysilazane, 16-20 parts of isocyanate composition, 10-14 parts of vulcanizing agent, 30-35 parts of modified filler, and 0.2-0.6 parts of silane coupling agent; The preparation method of phosphorus-containing polysilazane comprises the following steps: S1: Dissolve 10 mol of methylhydrogendichlorosilane in xylene to form a 5-5.5 wt% solution, and add 2-2.5 mol of methylhydrogendichlorosilane to form a 5-5.5 wt% solution.3 / h flow rate of nitrogen, circulate reaction, control the reaction temperature to 10-20 ° C, react for 10-12 hours, filter out the by-product ammonium chloride, and obtain an alkyl hydrogen silazane oligomer solution; then add a Custer catalyst (CAS No. 68478-92-2, Wuhan Lanabai Pharmaceutical Chemical Co., Ltd., platinum catalyst), react at 100-110 ° C for 24-28 hours, remove xylene by vacuum distillation, and after cooling, obtain solid methyl hydrogen polysilazane; S2: dissolving 100 parts by weight of solid methyl hydrogen polysilazane in 100-120 parts by weight of butyl acetate, adding hydroxyethyl methacrylate phosphate and stirring evenly, heating at 80-90° C. for reaction for 2-4 hours, and removing butyl acetate by rotary evaporation to obtain phosphorus-containing polysilazane.

[0008] Furthermore, the weight ratio of the solid methyl hydrogen polysilazane to hydroxyethyl methacrylate phosphate is 100:(2-4).

[0009] The present invention adds phosphorus-containing polysilazane to the rubber system, which can improve the thermal conductivity of butyl rubber. The phosphorus-containing polysilazane of the present invention introduces phosphorus element, and the phosphorus atom has a high electronegativity and a large atomic radius, and can form a stronger polar bond, which can enhance the interaction between molecules, thereby improving the thermal conductivity of the material. The Si-N bond in the silazane structure has a high bond energy and good thermal stability, and can form a relatively rigid network structure. This rigid network structure helps to improve the thermal conductivity of the material. The interface interaction between the phosphorus-containing polysilazane and the butyl rubber can form a good interface bonding, which can reduce thermal resistance and improve the heat transfer efficiency at the interface, thereby improving the overall thermal conductivity. At the same time, the tear strength of the special rubber for automobile inner tubes is improved.

[0010] Furthermore, the preparation method of the isocyanate composition comprises the following steps: by weight, (1) 10 parts of polycaprolactone diol PCL400 (Guangzhou Haoyi New Materials Technology Co., Ltd.) and 0.25-0.27 parts of dibutyltin dilaurate (CAS No. 77-58-7) were added to 50-54 parts of 1.6 hexanediol diacrylate, and three equal batches of HDI trimer (model BasonatHI100ap, brand BASF) totaling 50-55 parts were added. The reaction temperature was maintained at 60-70°C, and the change in the -NCO group content in the hexanediol diacrylate was detected. When the -NCO group content reached the theoretical value of 75.6, semi-adduct 1 was obtained; (2) adding 15-15.5 parts of hydroxyethyl acrylate to the semi-adduct 1, maintaining the reaction temperature at 60-70°C, detecting the change in the -NCO group content in the hexanediol diacrylate, and obtaining the semi-adduct 2 when the -NCO group content reaches the theoretical value of 24.0; (3) adding 7-7.4 parts of methyl ethyl ketoxime to the semi-adduct 2, maintaining the reaction temperature at 60-70°C, detecting the change in the -NCO group content in the hexanediol diacrylate, and obtaining a light-curable polycaprolactone modified blocked isocyanate when the -NCO group content is 0; (4) 30-35 parts of a photocurable resin monomer, 1-3 parts of a photoinitiator, 40-45 parts of a photocurable polycaprolactone modified blocked isocyanate, and 10-15 parts of a chain extender are mixed uniformly to obtain an isocyanate composition.

[0011] Furthermore, the photocurable resin monomer is a mixture of acrylate monomer, acrylamide monomer and vinylamide in a weight ratio of 1: (1.3-1.6): (0.5-0.7).

[0012] Furthermore, the chain extender is a diol with a functionality of 2 and a molecular weight of 500-600.

[0013] The present invention can improve the tensile strength of the special rubber for automobile inner tubes by adding an isocyanate composition to the special rubber for automobile inner tubes. Because under heating conditions, the light-cured polycaprolactone modified blocked isocyanate will be unblocked to release isocyanate groups, and the isocyanate groups can react with active hydrogen (such as hydroxyl, amino, etc.) in butyl rubber to form crosslinking points. These crosslinking points increase the crosslinking density between rubber molecular chains, thereby making the network structure of the rubber more compact and strong. At the same time, the photoinitiator decomposes under light to generate free radicals, which trigger the polymerization reaction of the resin monomer to form a highly crosslinked network structure. The higher crosslinking density can significantly improve the tensile strength of the rubber.

[0014] Furthermore, the preparation method of the modified nanomaterial comprises the following steps: (1) mixing single-walled carbon nanotubes, nano-alumina and nano-cerium oxide in a weight ratio of 1: (1.2-1.4): (0.6-0.8) to obtain a mixed material 1; (2) Mix 1 part by weight of mixed material 1, 0.2-0.4 parts of silane coupling agent KH550, 20-23 parts of ethanol and 30-35 parts of deionized water, heat and stir at 80-85° C. for 3-4 hours, cool, filter, wash and dry to obtain mixed material 2; (3) Mix the mixed material 2, nano-polytetrafluoroethylene, polyvinyl alcohol and 45-50wt% ethanol aqueous solution in a weight ratio of 1: (10-15): (0.1-0.4): (60-80), disperse them evenly, and then spray dry them to obtain modified nanomaterials.

[0015] Furthermore, the single-walled carbon nanotube has a diameter of 1-2 nm, a length of 5-30 μm, and a specific surface area of ​​120 m 2 / g, the particle size of nano-alumina is 15-20nm, and the specific surface area is 150-200m 2 / g; the particle size of nano cerium oxide is 5-15nm, and the specific surface area is 20-40m 2 / g.

[0016] The present invention attempts to reduce the gas permeability coefficient of the special rubber for automobile inner tubes and improve the sealing performance by adding nano materials, but the effect is not ideal. The present invention can improve the gas permeability coefficient of the special rubber for automobile inner tubes by modifying the nano materials. Analysis shows that the modified nano materials have higher compatibility in the system, thereby improving the gas permeability coefficient of the special rubber for automobile inner tubes.

[0017] When the nanomaterials with specific parameters and the photocurable resin monomers with specific proportions are used in the system of the present invention, the tensile strength of the rubber for automobile inner tubes after thermal aging can be improved. The nanomaterials of the present invention have a high specific surface area, can provide more active sites, and enhance the interaction with the rubber matrix. The cross-linked network formed by the nanomaterials and the resin monomers can improve the structural stability of the rubber, reduce the breakage of the molecular chains and the destruction of the cross-linking points during the thermal aging process, thereby maintaining the tensile strength of the rubber.

[0018] Nano polytetrafluoroethylene, Guangzhou Yinuo Chemical Technology Co., Ltd., brand JYN815.

[0019] Polyvinyl alcohol, Shandong Hongquan Chemical Technology Co., Ltd., PVA2488.

[0020] Furthermore, the silane coupling agent is selected from one or more of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0021] Furthermore, the vulcanizing agent is sulfur, which is purchased from Weifang Zhongheng Chemical Co., Ltd.

[0022] The present invention also provides a method for preparing heat-resistant and aging-resistant special rubber for automobile inner tubes, comprising the following steps: (1) Add butyl rubber into an internal mixer, with an initial mixing temperature of 70-75°C and a plasticizing time of 0.5-1 min; add phosphorus-containing polysilazane, with a mixing temperature of 110-120°C and a mixing time of 10-15 min to obtain a masterbatch; (2) adding the first-stage masterbatch and the isocyanate composition into an internal mixer, mixing for 7-10 min at a mixing temperature of 120-125° C. to obtain a second-stage masterbatch; (3) The second-stage masterbatch is mixed with the remaining components for the third time at a mixing temperature of 105-110°C for 5-10 minutes to obtain the final mixed rubber; (4) After the final rubber is pressed and cut into sheets on an open mixer, it is placed in a flat vulcanizer for vulcanization at a vulcanization temperature of 150-160°C, a vulcanization pressure of 15-20 MPa, and a vulcanization time of 30-40 min to obtain a heat-resistant and aging-resistant special rubber for automobile inner tubes.

[0023] Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. The present invention adds phosphorus-containing polysilazane to the rubber system, which can improve the thermal conductivity of butyl rubber and the tear strength of the special rubber for automobile inner tubes.

[0024] 2. The present invention can improve the tensile strength of the special rubber for automobile inner tubes by adding an isocyanate composition to the special rubber for automobile inner tubes.

[0025] 3. The present invention can improve the gas permeability coefficient of the special rubber for automobile inner tubes by modifying the nanomaterials.

[0026] 4. When nanomaterials with specific parameters and photocurable resin monomers with specific ratios are used in the system of the present invention, the tensile strength of the rubber for automobile inner tubes after thermal aging can be improved. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example 1 This embodiment provides a heat-resistant and aging-resistant special rubber for automobile inner tubes, comprising the following components in parts by weight: 100 parts of butyl rubber, 10 parts of phosphorus-containing polysilazane, 18 parts of isocyanate composition, 12 parts of vulcanizing agent, 32 parts of modified filler, and 0.4 parts of silane coupling agent; the silane coupling agent is silane coupling agent KH550. The vulcanizing agent is sulfur. It was purchased from Weifang Zhongheng Chemical Co., Ltd.

[0029] The preparation method of phosphorus-containing polysilazane comprises the following steps: S1: Dissolve 10 mol of methylhydrogendichlorosilane in xylene to form a 5.2 wt% solution. 3 / h flow rate of nitrogen, circulate reaction, control the reaction temperature to 15 ° C, react for 11 hours, filter out the by-product ammonium chloride, and obtain an alkyl hydrogen silazane oligomer solution; then add a Custer catalyst (CAS No. 68478-92-2, Wuhan Lanabai Pharmaceutical Chemical Co., Ltd., platinum catalyst) accounting for 110 ppm of the weight of the alkyl hydrogen silazane oligomer solution, react at 105 ° C for 26 hours, remove xylene by vacuum distillation, and after cooling, obtain solid methyl hydrogen polysilazane; S2: 100 parts by weight of solid methyl hydrogen polysilazane is dissolved in 110 parts by weight of butyl acetate, hydroxyethyl methacrylate phosphate is added and stirred evenly, and the mixture is heated at 85° C. for 3 hours, and butyl acetate is removed by rotary evaporation to obtain phosphorus-containing polysilazane.

[0030] The weight ratio of the solid methyl hydrogen polysilazane to hydroxyethyl methacrylate phosphate is 100:3.

[0031] The preparation method of the isocyanate composition comprises the following steps: by weight, (1) 10 parts of polycaprolactone diol PCL400 (Guangzhou Haoyi New Materials Technology Co., Ltd.) and 0.26 parts of dibutyltin dilaurate (CAS No. 77-58-7) were added to 52 parts of 1.6 hexanediol diacrylate, and three equal batches of HDI trimer (model BasonatHI100ap, brand BASF) totaling 52 parts were added. The reaction temperature was maintained at 65°C, and the change in the -NCO group content in the hexanediol diacrylate was detected. When the -NCO group content reached the theoretical value of 75.6, semi-adduct 1 was obtained; (2) Add 15.2 parts of hydroxyethyl acrylate to the semi-adduct 1, maintain the reaction temperature at 65°C, and detect the change in the -NCO group content in hexanediol diacrylate. When the -NCO group content reaches the theoretical value of 24.0, the semi-adduct 2 is obtained; (3) Add 7.2 parts of methyl ethyl ketoxime to the semi-adduct 2, maintain the reaction temperature at 65°C, and detect the change in the -NCO group content in hexanediol diacrylate. When the -NCO group content is 0, a photocurable polycaprolactone modified blocked isocyanate is obtained; (4) 32 parts of a photocurable resin monomer, 2 parts of a photoinitiator benzoin ethyl ether, 42 parts of a photocurable polycaprolactone modified blocked isocyanate, and 10-15 parts of a chain extender are mixed uniformly to obtain an isocyanate composition.

[0032] The photocurable resin monomer is a mixture of acrylate monomer, acrylamide monomer and vinylamide in a weight ratio of 1:1.5:0.6.

[0033] The chain extender is polycaprolactone diol with a molecular weight of 550 and a typical hydroxyl value of 204 mgKOH / g, purchased from Guangzhou Haoyi New Materials Technology Co., Ltd., model Pasto Capa 2054.

[0034] The preparation method of the modified nanomaterial comprises the following steps: (1) mixing single-walled carbon nanotubes, nano-alumina and nano-cerium oxide in a weight ratio of 1:1.3:0.7 to obtain a mixed material 1; (2) Mix 1 part of mixed material 1, 0.3 part of silane coupling agent KH550, 22 parts of ethanol and 32 parts of deionized water in a weight ratio, heat and stir at 82° C. for 3.5 h, cool, filter, wash and dry to obtain mixed material 2; (3) Mix the mixed material 2, nano-polytetrafluoroethylene, polyvinyl alcohol and 47 wt % ethanol aqueous solution in a weight ratio of 1:12:0.3:70, disperse them evenly, and then spray dry them to obtain a modified nanomaterial.

[0035] The single-walled carbon nanotube has a diameter of 1-2 nm, a length of 5-30 μm, and a specific surface area of ​​120 m 2 / g, the particle size of nano-alumina is 15-20nm, and the specific surface area is 150-200m 2 / g; the particle size of nano cerium oxide is 5-15nm, and the specific surface area is 20-40m 2 / g.

[0036] Nano polytetrafluoroethylene, Guangzhou Yinuo Chemical Technology Co., Ltd., brand JYN815.

[0037] Polyvinyl alcohol, Shandong Hongquan Chemical Technology Co., Ltd., PVA2488.

[0038] The method for preparing the heat-resistant and aging-resistant special rubber for automobile inner tubes comprises the following steps: (1) Add butyl rubber into an internal mixer, with an initial mixing temperature of 72°C and a plasticizing time of 0.5 min; add phosphorus-containing polysilazane, with a mixing temperature of 115°C and a mixing time of 12 min to obtain a masterbatch; (2) adding the first-stage masterbatch and the isocyanate composition into an internal mixer, mixing for 8 min at a mixing temperature of 122° C. to obtain a second-stage masterbatch; (3) The second-stage masterbatch and the remaining components are mixed for the third time at a mixing temperature of 108°C for 8 minutes to obtain the final mixed rubber; (4) The final rubber mixture is pressed and cut into sheets on an open mixer and then placed in a flat vulcanizer for vulcanization at a vulcanization temperature of 155°C, a vulcanization pressure of 18 MPa, and a vulcanization time of 35 min to obtain a heat-resistant and aging-resistant special rubber for automobile inner tubes.

[0039] Example 2 This embodiment provides a heat-resistant and aging-resistant special rubber for automobile inner tubes, comprising the following components in parts by weight: 100 parts of butyl rubber, 8 parts of phosphorus-containing polysilazane, 20 parts of isocyanate composition, 10 parts of vulcanizing agent, 35 parts of modified filler, and 0.2 parts of silane coupling agent; the silane coupling agent is silane coupling agent KH570. The vulcanizing agent is sulfur. It was purchased from Weifang Zhongheng Chemical Co., Ltd.

[0040] The preparation method of phosphorus-containing polysilazane comprises the following steps: S1: Dissolve 10 mol of methylhydrogendichlorosilane in xylene to form a 5.5 wt% solution. 3 / h flow rate of nitrogen, circulate reaction, control the reaction temperature to 20 ° C, react for 10 hours, filter out the by-product ammonium chloride, and obtain an alkyl hydrogen silazane oligomer solution; then add a Custer catalyst (CAS No. 68478-92-2, Wuhan Lanabai Pharmaceutical Chemical Co., Ltd., platinum catalyst) accounting for 110ppm of the weight of the alkyl hydrogen silazane oligomer solution, react at 110 ° C for 24 hours, remove xylene by vacuum distillation, and after cooling, obtain solid methyl hydrogen polysilazane; S2: 100 parts by weight of solid methyl hydrogen polysilazane is dissolved in 120 parts by weight of butyl acetate, hydroxyethyl methacrylate phosphate is added and stirred evenly, and then heated at 80° C. for 4 hours, and butyl acetate is removed by rotary evaporation to obtain phosphorus-containing polysilazane.

[0041] The weight ratio of the solid methyl hydrogen polysilazane to hydroxyethyl methacrylate phosphate is 100:2.1.

[0042] The preparation method of the isocyanate composition comprises the following steps: by weight, (1) 10 parts of polycaprolactone diol PCL400 (Guangzhou Haoyi New Materials Technology Co., Ltd.) and 0.25 parts of dibutyltin dilaurate (CAS No. 77-58-7) were added to 54 parts of 1.6 hexanediol diacrylate, and three equal batches of HDI trimer (model BasonatHI100ap, brand BASF) totaling 50 parts were added. The reaction temperature was maintained at 70°C, and the change in the -NCO group content in the hexanediol diacrylate was detected. When the -NCO group content reached the theoretical value of 75.6, semi-adduct 1 was obtained; (2) Add 15.5 parts of hydroxyethyl acrylate to the semi-adduct 1, maintain the reaction temperature at 60°C, and detect the change in the -NCO group content in hexanediol diacrylate. When the -NCO group content reaches the theoretical value of 24.0, the semi-adduct 2 is obtained; (3) Add 7 parts of methyl ethyl ketoxime to the semi-adduct 2, maintain the reaction temperature at 70°C, and detect the change in the -NCO group content in hexanediol diacrylate. When the -NCO group content is 0, a photocurable polycaprolactone modified blocked isocyanate is obtained; (4) 30 parts of a photocurable resin monomer, 3 parts of a photoinitiator benzoin ethyl ether, 40 parts of a photocurable polycaprolactone modified blocked isocyanate, and 15 parts of a chain extender are mixed uniformly to obtain an isocyanate composition.

[0043] The photocurable resin monomer is a mixture of acrylate monomer, acrylamide monomer and vinylamide in a weight ratio of 1:1.3:0.7.

[0044] The chain extender is polycaprolactone diol with a molecular weight of 550 and a typical hydroxyl value of 204 mgKOH / g, purchased from Guangzhou Haoyi New Materials Technology Co., Ltd., model Pasto Capa 2054.

[0045] The preparation method of the modified nanomaterial comprises the following steps: (1) mixing single-walled carbon nanotubes, nano-alumina and nano-cerium oxide in a weight ratio of 1:1.2:0.6 to obtain a mixed material 1; (2) Mixing 1 part by weight of mixed material 1, 0.4 part by weight of silane coupling agent KH550, 23 parts by weight of ethanol and 30 parts by weight of deionized water, heating and stirring at 85° C. for 3 h, cooling, filtering, washing and drying to obtain mixed material 2; (3) Mix the mixed material 2, nano-polytetrafluoroethylene, polyvinyl alcohol and 45 wt % ethanol aqueous solution in a weight ratio of 1:10:0.1:60, disperse them evenly, and then spray dry them to obtain a modified nano-material.

[0046] The single-walled carbon nanotube has a diameter of 1-2 nm, a length of 5-30 μm, and a specific surface area of ​​120 m 2 / g, the particle size of nano-alumina is 15-20nm, and the specific surface area is 150-200m 2 / g; the particle size of nano cerium oxide is 5-15nm, and the specific surface area is 20-40m 2 / g.

[0047] Nano polytetrafluoroethylene, Guangzhou Yinuo Chemical Technology Co., Ltd., brand JYN815.

[0048] Polyvinyl alcohol, Shandong Hongquan Chemical Technology Co., Ltd., PVA2488.

[0049] The method for preparing the heat-resistant and aging-resistant special rubber for automobile inner tubes comprises the following steps: (1) Add butyl rubber into an internal mixer, with an initial mixing temperature of 70°C and a plasticizing time of 0.5 min; add phosphorus-containing polysilazane, with a mixing temperature of 120°C and a mixing time of 15 min to obtain a masterbatch; (2) adding the first-stage masterbatch and the isocyanate composition into an internal mixer, mixing for 10 min at a mixing temperature of 125° C. to obtain a second-stage masterbatch; (3) The second-stage masterbatch and the remaining components are mixed for the third time at a mixing temperature of 110°C for 10 min to obtain the final mixed rubber; (4) The final rubber mixture is pressed and cut into sheets on an open mixer, and then placed in a flat vulcanizer for vulcanization at a vulcanization temperature of 150°C, a vulcanization pressure of 20 MPa, and a vulcanization time of 30 min, thereby obtaining a heat-resistant and aging-resistant special rubber for automobile inner tubes.

[0050] Comparative Example 1 The difference between this comparative example and Example 1 is: a heat-resistant and aging-resistant special rubber for automobile inner tubes, comprising the following components in parts by weight: 100 parts of butyl rubber, 28 parts of phosphorus-containing polysilazane, 12 parts of vulcanizing agent, 32 parts of modified filler, and 0.4 parts of silane coupling agent.

[0051] Comparative Example 2 The difference between this comparative example and Example 1 is: a heat-resistant and aging-resistant special rubber for automobile inner tubes, comprising the following components in parts by weight: 100 parts of butyl rubber, 28 parts of isocyanate composition, 12 parts of vulcanizing agent, 32 parts of modified filler, and 0.4 parts of silane coupling agent.

[0052] Comparative Example 3 The difference between this comparative example and Example 1 is: a heat-resistant and aging-resistant special rubber for automobile inner tubes, comprising the following components in parts by weight: 100 parts of butyl rubber, 18 parts of phosphorus-containing polysilazane, 10 parts of isocyanate composition, 12 parts of vulcanizing agent, 32 parts of modified filler, and 0.4 parts of silane coupling agent.

[0053] Comparative Example 4 The difference between this comparative example and Example 1 is that the photocurable resin monomer is a mixture of acrylate monomer, acrylamide monomer and vinylamide in a weight ratio of 1:1:1.

[0054] Comparative Example 5 The difference between this comparative example and Example 1 is that single-walled carbon nanotubes, nano-alumina and nano-cerium oxide are mixed in a weight ratio of 1:1:1 to obtain a mixed material 1.

[0055] Comparative Example 6 The difference between this comparative example and Example 1 is that the diameter of the single-walled carbon nanotube is 4-6 nm, the length is 20-30 μm, and the specific surface area is 80 m 2 / g; the particle size of nano-alumina is 20-30nm, and the specific surface area is 50-100m 2 / g; and the particle size of nano cerium oxide is 30-50nm, and the specific surface area is 40-60m 2 / g.

[0056] Comparative Example 7 The difference between this comparative example and Example 1 is: The preparation method of the modified nanomaterial comprises the following steps: (1) mixing single-walled carbon nanotubes, nano-alumina and nano-cerium oxide in a weight ratio of 1:1.3:0.7 to obtain a mixed material 1; (2) Mix 1 part of mixed material 1, 0.3 part of silane coupling agent KH550, 22 parts of ethanol and 32 parts of deionized water in a weight ratio, heat and stir at 82° C. for 3.5 h, cool, filter, wash and dry to obtain a modified nanomaterial.

[0057] Performance Testing The special rubbers for automobile inner tubes prepared in Examples 1-2 and Comparative Examples 1-7 were subjected to performance tests.

[0058] 1. Use GT-AT-3000 universal tensile testing machine to test tensile stress-strain properties according to GB / T528-2009; 2. Test tear strength according to GB / T529-2008. 3. Determine the heat-resistant air aging test with reference to GB / T3512-2001: 100℃×72h, calculate the tensile strength retention rate = tensile strength after aging / tensile strength before aging × 100%; elongation at break retention rate = elongation at break after aging / elongation at break before aging × 100%.

[0059] 4. The air permeability coefficient is measured by an automated air permeability tester according to ISO2782:1995. The test gas is N 2 , the test temperature is 23℃, the test sample is a circular sheet with a diameter of 8cm and a thickness of 1mm.

[0060] 5. The thermal conductivity is tested by TC3000 thermal conductivity meter produced by Xianxiaxi Electronic Technology Co., Ltd. The sample test conditions are: pressure 500g, acquisition time 5s, heating voltage 1.0v, acquisition mode normal, and temperature is room temperature.

[0061] Table 1 Performance test results From the above performance test results, it can be seen that the heat-resistant and aging-resistant special rubber for automobile inner tubes of Examples 1-2 have excellent comprehensive performance and good heat resistance and aging resistance, especially the comprehensive performance of Example 1 is the most outstanding, which is mainly due to the synergistic effect between the components.

[0062] However, the comparative examples are obviously inferior to the embodiments in the corresponding performance tests because they do not adopt the necessary technical solutions. No isocyanate composition is added to comparative example 1, no phosphorus-containing polysilazane is added to Dibili 2, and the ratio of phosphorus-containing polysilazane and isocyanate composition in comparative example 3 is different. From the results, it can be seen that the thermal conductivity and tensile strength of the special rubber for automobile inner tubes are reduced, indicating that the phosphorus-containing polysilazane and isocyanate composition are compounded and added to the special rubber for automobile inner tubes at the same time, which can improve the thermal conductivity and tensile strength of the special rubber for automobile inner tubes. The ratio of the photocurable resin monomer in comparative example 4 is different. From the results, it can be seen that the tensile strength of the special rubber for automobile inner tubes after thermal aging is reduced; the ratio of nanomaterials in comparative example 5 is different, and the gas permeability coefficient of the special rubber for automobile inner tubes is deteriorated; the parameters of nanomaterials in comparative example 6 are different, and the tensile strength of the special rubber for automobile inner tubes after thermal aging is reduced; the modification method of nanomaterials in comparative example 7 is different, and the gas permeability coefficient of the special rubber for automobile inner tubes is deteriorated. The above experimental results further prove the importance of the technical solution defined in the present invention for its technical effect.

[0063] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A heat-resistant and aging-resistant special rubber for automobile inner tubes, characterized in that: The invention comprises the following components in parts by weight: 100 parts of butyl rubber, 8-12 parts of phosphorus-containing polysilazane, 16-20 parts of isocyanate composition, 10-14 parts of vulcanizing agent, 30-35 parts of modified filler, and 0.2-0.6 parts of silane coupling agent; The preparation method of phosphorus-containing polysilazane comprises the following steps: S1: Dissolve 10 mol of methylhydrogendichlorosilane in xylene to form a 5-5.5 wt% solution, and add 2-2.5 mol of methylhydrogendichlorosilane to form a 5-5.5 wt% solution. 3 / h flow rate of nitrogen, circulate reaction, control the reaction temperature to 10-20 ° C, react for 10-12 hours, filter out the by-product ammonium chloride, and obtain an alkyl hydrogen silazane oligomer solution; then add a Custer catalyst, react at 100-110 ° C for 24-28 hours, remove xylene by vacuum distillation, and after cooling, obtain solid methyl hydrogen polysilazane; S2: dissolving 100 parts by weight of solid methyl hydrogen polysilazane in 100-120 parts by weight of butyl acetate, adding hydroxyethyl methacrylate phosphate and stirring evenly, heating at 80-90° C. for reaction for 2-4 hours, and removing butyl acetate by rotary evaporation to obtain phosphorus-containing polysilazane.

2. The heat-resistant and aging-resistant special rubber for automobile inner tubes according to claim 1, characterized in that: The weight ratio of the solid methyl hydrogen polysilazane to hydroxyethyl methacrylate phosphate is 100:(2-4).

3. The heat-resistant and aging-resistant special rubber for automobile inner tubes according to claim 1, characterized in that: The preparation method of the isocyanate composition comprises the following steps: by weight, (1) 10 parts of polycaprolactone diol PCL400 and 0.25-0.27 parts of dibutyltin dilaurate are added to 50-54 parts of 1.6 hexanediol diacrylate, and three equal batches of HDI trimer are added, totaling 50-55 parts, and the reaction temperature is maintained at 60-70° C. The change in the -NCO group content in the hexanediol diacrylate is detected. When the -NCO group content reaches the theoretical value of 75.6, a semi-adduct 1 is obtained; (2) adding 15-15.5 parts of hydroxyethyl acrylate to the semi-adduct 1, maintaining the reaction temperature at 60-70° C., detecting the change in the -NCO group content in the hexanediol diacrylate, and obtaining the semi-adduct 2 when the -NCO group content reaches the theoretical value of 24.0; (3) adding 7-7.4 parts of methyl ethyl ketoxime to the semi-adduct 2, maintaining the reaction temperature at 60-70° C., detecting the change in the -NCO group content in the hexanediol diacrylate, and obtaining a light-curable polycaprolactone modified blocked isocyanate when the -NCO group content is 0; (4) 30-35 parts of a photocurable resin monomer, 1-3 parts of a photoinitiator, 40-45 parts of a photocurable polycaprolactone modified blocked isocyanate, and 10-15 parts of a chain extender are mixed uniformly to obtain an isocyanate composition.

4. The heat-resistant and aging-resistant special rubber for automobile inner tubes according to claim 3, characterized in that: The photocurable resin monomer is a mixture of acrylate monomer, acrylamide monomer and vinylamide in a weight ratio of 1: (1.3-1.6): (0.5-0.7).

5. The heat-resistant and aging-resistant special rubber for automobile inner tubes according to claim 3, characterized in that: The chain extender is a diol with a functionality of 2 and a molecular weight of 500-600.

6. The heat-resistant and aging-resistant special rubber for automobile inner tubes according to claim 1, characterized in that: The preparation method of the modified nanomaterial comprises the following steps: (1) mixing single-walled carbon nanotubes, nano-alumina and nano-cerium oxide in a weight ratio of 1: (1.2-1.4): (0.6-0.8) to obtain a mixed material 1; (2) mixing 1 part by weight of mixed material 1, 0.2-0.4 part by weight of silane coupling agent KH550, 20-23 parts by weight of ethanol and 30-35 parts by weight of deionized water, heating and stirring at 80-85° C. for 3-4 hours, cooling, filtering, washing and drying to obtain mixed material 2; (3) Mix the mixed material 2, nano-polytetrafluoroethylene, polyvinyl alcohol and 45-50wt% ethanol aqueous solution in a weight ratio of 1: (10-15): (0.1-0.4): (60-80), disperse them uniformly, and then spray dry them to obtain modified nano-materials.

7. The heat-resistant and aging-resistant special rubber for automobile inner tubes according to claim 6, characterized in that: The single-walled carbon nanotube has a diameter of 1-2 nm, a length of 5-30 μm, and a specific surface area of ​​120 m 2 / g, the particle size of nano-alumina is 15-20nm, and the specific surface area is 150-200m 2 / g; the particle size of nano cerium oxide is 5-15nm, and the specific surface area is 20-40m 2 / g.

8. The heat-resistant and aging-resistant special rubber for automobile inner tubes according to claim 1, characterized in that: The silane coupling agent is selected from one or more of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570.

9. The heat-resistant and aging-resistant special rubber for automobile inner tubes according to claim 1, characterized in that: The vulcanizing agent is sulfur.

10. A method for preparing the heat-resistant and aging-resistant special rubber for automobile inner tubes according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) adding butyl rubber into an internal mixer, with an initial mixing temperature of 70-75° C. and a plasticizing time of 0.5-1 min; adding phosphorus-containing polysilazane, with a mixing temperature of 110-120° C. and a mixing time of 10-15 min, to obtain a masterbatch; (2) adding the first-stage masterbatch and the isocyanate composition into an internal mixer, mixing for 7-10 min at a mixing temperature of 120-125° C. to obtain a second-stage masterbatch; (3) The second-stage masterbatch is mixed with the remaining components for the third time at a mixing temperature of 105-110° C. for a mixing time of 5-10 min to obtain a final mixed rubber; (4) After the final rubber is pressed and cut into pieces on an open mixer, it is placed in a flat vulcanizer for vulcanization at a vulcanization temperature of 150-160° C., a vulcanization pressure of 15-20 MPa, and a vulcanization time of 30-40 min to obtain a heat-resistant and aging-resistant special rubber for automobile inner tubes.

Images