Method for preparing a non-pneumatic tire using waste tires

Abstract

The application provides a method for preparing a non-pneumatic tire by using waste tires, and comprises the following steps: waste tire recycling, coarse rubber powder pretreatment and non-pneumatic tire preparation. The non-pneumatic tire prepared by the method can be prepared by using waste tires. The waste tires are pretreated to obtain coarse rubber powder containing short fibers, and the non-pneumatic tire is prepared by using the coarse rubber powder. The process is green and environmentally friendly, and the product quality is good.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of materials, and particularly relates to a method for preparing a non-pneumatic tire by using waste and old tires. BACKGROUND

[0002] Tire is one of the main application products of rubber products, and half of the rubber consumption in the world is used for tire manufacturing, and the development of rubber materials applied to tires needs strong theoretical support and innovation. Although solid tires are not the mainstream products in tires, they are widely used in important fields such as mineral exploitation, engineering construction and cargo transportation due to their good load capacity and safety. In actual application, although the solid rubber tire has many advantages, the poor performance of the tire body material and the simple structure still limit its further application.

[0003] The selection of the tire body material of the solid tire is the key to tire manufacturing, and rubber material has a history of many years in the application in tire manufacturing as a material with high elasticity and stress deformation recovery. At present, rubber is still selected as the tire body material of the mainstream solid tire.

[0004] In recent years, polyurethane as a new material is also applied to tire manufacturing. Polyurethane elastomer also has elasticity, and its strength and wear resistance are better than those of rubber to some extent, which is the application basis of polyurethane as a tire material. At the same time, polyurethane material has a lower loss factor under dynamic use conditions, and can provide lower rolling resistance of the tire as a tire material, and has great advantages in energy saving. Since the 1970s of the last century, some tire companies abroad began to apply polyurethane material to tires, and the first company to use polyurethane to prepare solid tires was the American Goodyear Tire Company, which was followed by other companies. However, in recent years, polyurethane has not been better developed and applied.

[0005] Polyurethane tires have two fatal defects in actual use. One is that the heat resistance of polyurethane is poor. Although there is research and development of heat-resistant polyurethane materials, the upper limit of the temperature suitable for the application of polyurethane materials to tires is 80-90℃, and the strength and fatigue resistance of polyurethane materials will decrease seriously when the temperature exceeds this limit. For heavy-duty solid tires, the actual use temperature will be very high. The other is that the adhesion of polyurethane material to the ground is weaker than that of rubber, which makes the traction and wet skid resistance of polyurethane tires poor, and also limits the use of polyurethane tires. SUMMARY

[0006] Technical problem: In order to solve the defects of the prior art, the purpose of the present application is to provide a method for preparing a non-pneumatic tire by using waste and old tires.

[0007] Technical scheme: The present application provides a method for preparing a non-pneumatic tire by using waste and old tires, comprising the following steps:

[0008] (1) Waste and old tire recycling: clean the waste and old tire contained, crush the cleaned rubber in a crusher to 20-30mm coarse particles, and remove the iron impurities and coarse rubber particles through first magnetic separation; grind the coarse rubber particles in a grinder to 5-10mm, remove the iron impurities through second magnetic separation, continue to grind in a grinding wheel to 0.5-1.4mm, and screen through a filter screen, to obtain coarse rubber powder containing short fibers;

[0009] (2) Coarse rubber powder pretreatment: under low-temperature and anaerobic environment, desulfurize and regenerate the coarse rubber powder containing short fibers at 140-200℃ and 8-18Mpa for 1-6h by using swelling solvent as medium and thiol sulfide as desulfurizing agent, and the amount of desulfurizing agent is 8-15%.

[0010] (3) Preparation of airless tire:

[0011] (3.1) Stir the hydroxyl-alkyl silicone oil and the vinyl polyether uniformly in the presence of solvent, heat to 55-65℃, and react for 1-3h in the presence of catalyst; continue to heat the reaction system to 70-80℃, and then add diisocyanate, polyol, dimethylol propionic acid chain extender and triethylamine neutralizer, and continue to stir for 2-6h; under constant temperature, drop the capping agent, and continue to react for 3-5h, to obtain modified polyurethane;

[0012] (3.2) Put the pretreated coarse rubber powder, modified polyurethane, aramid fiber, antioxidant, deionized water, half of the mass of sulfur, aromatic oil, zinc oxide and stearic acid into a mixer, mix for 30-50s at a rotation speed of 60-100r / min, then add carbon black, antioxidant, silane coupling agent KH-560 and accelerator NS, mix for 30-50s at a rotation speed of 80-120r / min, perform discharge treatment on the reaction product, cool to room temperature, add the remaining sulfur into the mixed rubber, mix uniformly, perform vulcanization treatment, cool to room temperature, and shape, to obtain the airless tire.

[0013] In step (2), the swelling solvent is supercritical carbon dioxide or supercritical ethanol; and the thiol sulfide is dithiothreitol, diphenyl disulfide or n-hexane thiol.

[0014] In step (3.1), the diisocyanate is 2,4-toluene diisocyanate, isophorone diisocyanate or hexane diisocyanate.

[0015] In step (3.1), the polyol is polyester diol with a molecular weight of 600-1000 or polypropylene glycol with a molecular weight of 400-2000.

[0016] In step (3.1), the catalyst is dibutyl tin dilaurate or stannous octoate; the solvent is butanone, N,N-dimethylformamide, toluene and / or N-methyl pyrrolidone.

[0017] In step (3.1), the terminal hydroxyalkyl silicone oil is a terminal hydroxymethyl silicone oil, a terminal hydroxyethyl silicone oil, a terminal hydroxypropyl silicone oil, or a terminal hydroxybutyl silicone oil.

[0018] In step (3.2), the amounts of the raw materials are as follows: 100 parts of the short-fiber-containing crude rubber powder, 30-40 parts of styrene-butadiene rubber, 20-30 parts of modified polyurethane, 80-120 parts of carbon black, 5-15 parts of aramid fiber, 5-10 parts of antioxidant, 3-6 parts of sulfur, 10-30 parts of aromatic oil, 1-3 parts of zinc oxide, 1-3 parts of stearic acid, 5-10 parts of silane coupling agent KH-560, and 4-8 parts of accelerator NS.

[0019] In step (3.2), the amounts of the raw materials are as follows: 100 parts of the short-fiber-containing crude rubber powder, 35 parts of styrene-butadiene rubber, 25 parts of modified polyurethane, 100 parts of carbon black, 10 parts of aramid fiber, 7.5 parts of antioxidant, 4.5 parts of sulfur, 20 parts of aromatic oil, 2 parts of zinc oxide, 2 parts of stearic acid, 7.5 parts of silane coupling agent KH-560, and 6 parts of accelerator NS.

[0020] Beneficial effects: The preparation method of the airless tire provided by the application can utilize waste tires to prepare the airless tire, the waste tires are pretreated to obtain the short-fiber-containing crude rubber powder, and the short-fiber-containing crude rubber powder is used to prepare the airless tire, so that the process is green and environmentally friendly, and the product quality is good. DETAILED DESCRIPTION

[0021] The following examples are given to further illustrate the application in conjunction with the specific embodiments. The following examples are merely illustrative of the present application and are not limiting the scope of the application.

[0022] In the following examples, the experimental methods are conventional experimental methods unless otherwise specified. The raw materials, experimental reagents, etc. used in the examples are commercially available products unless otherwise specified.

[0023] Example 1

[0024] The method for preparing the airless tire by using waste tires comprises the following steps:

[0025] (1) Waste and old tire recycling: clean the waste and old tire contained, crush the cleaned rubber in a crusher to 20-30mm coarse particles, remove the iron impurities and coarse rubber particles from the coarse particles by first magnetic separation; grind the coarse rubber particles to 5-10mm by a grinder, remove the iron impurities by second magnetic separation, continue to grind to 0.5-1.4mm by a grinding wheel, and screen by a filter screen, to obtain the coarse rubber powder containing short fibers;

[0026] (2) Coarse rubber powder pretreatment: under the conditions of low temperature and oxygen-free environment, desulfurize and regenerate the coarse rubber powder containing short fibers by using swelling solvent as medium and thiol sulfide as desulfurizing agent at 160℃ and 12Mpa for 3h, and the amount of desulfurizing agent is 7%;

[0027] The swelling solvent is supercritical carbon dioxide; and the thiol sulfide is dithiothreitol.

[0028] (3) Preparation of the airless tire:

[0029] (3.1) Stir the hydroxyl alkyl silicone oil and the vinyl polyether uniformly in the presence of a solvent, heat to 60℃, and react for 2h in the presence of a catalyst; continue to heat the reaction system to 75℃, and then add diisocyanate, polyol, dimethylol propionic acid chain extender, and triethylamine neutralizer, and continue to stir for 4h; under constant temperature, drop the capping agent, and continue to react for 4h, to obtain the modified polyurethane;

[0030] The diisocyanate is 2,4-toluene diisocyanate; the polyol is polyester diol with a molecular weight of 600-1000; the catalyst is dibutyl tin dilaurate; the solvent is N,N-dimethylformamide; and the hydroxyl alkyl silicone oil is hydroxymethyl silicone oil.

[0031] (3.2) Put the pretreated coarse rubber powder, modified polyurethane, aramid fiber, antioxidant, deionized water, half of the amount of sulfur, aromatic oil, zinc oxide, and stearic acid into a banbury mixer, mix for 40s at a rotation speed of 80r / min, then add carbon black, antioxidant, silane coupling agent KH-560, and accelerator NS, mix for 40s at a rotation speed of 100r / min, perform discharge treatment on the reaction mixture, cool to room temperature, add the remaining sulfur to the mixed rubber, mix uniformly, perform vulcanization treatment, cool to room temperature, and shape, to obtain the airless tire.

[0032] The amount of each raw material is as follows: coarse rubber powder containing short fibers 100 parts, styrene-butadiene rubber 35 parts, modified polyurethane 25 parts, carbon black 100 parts, aramid fiber 10 parts, antioxidant 7.5 parts, sulfur 4.5 parts, aromatic oil 20 parts, zinc oxide 2 parts, stearic acid 2 parts, silane coupling agent KH-560 7.5 parts, and accelerator NS 6 parts.

[0033] Example 2

[0034] The method for preparing the non-pneumatic tire by using waste tires comprises the following steps:

[0035] (1) Waste tire recycling: clean the waste tires, crush the cleaned rubber into coarse particles of 20-30 mm in a crusher, remove the iron impurities and coarse rubber particles by first magnetic separation, grind the coarse rubber particles into 5-10 mm by a grinding machine, remove the iron impurities by second magnetic separation, continue to grind to 0.5-1.4 mm by a grinding wheel, and screen by a filter screen to obtain coarse rubber powder containing short fibers.

[0036] (2) Coarse rubber powder pretreatment: under the conditions of low temperature and anaerobic environment, desulfurize and regenerate the coarse rubber powder containing short fibers by using swelling solvent as medium and thiol sulfide as desulfurizing agent at 140℃ and 18Mpa for 6h, and the amount of desulfurizing agent is 15%.

[0037] The swelling solvent is supercritical ethanol, and the thiol sulfide is diphenyl disulfide.

[0038] (3) Preparation of non-pneumatic tire:

[0039] (3.1) Stir the hydroxyalkyl silicone oil and the vinyl polyether uniformly in the presence of a solvent, heat to 55℃, and stir to react for 3h in the presence of a catalyst; continue to heat the reaction system to 80℃, and then add diisocyanate, polyol, chain extender dimethylol propionic acid, and triethylamine neutralizer, and continue to stir to react for 2h; under constant temperature conditions, add a capping agent dropwise, and continue to react for 3-5h to obtain modified polyurethane.

[0040] The diisocyanate is isophorone diisocyanate, the polyol is polyester diol with a molecular weight of 600-1000, the catalyst is dibutyl tin dilaurate, the solvent is N-methyl pyrrolidone, and the hydroxyalkyl silicone oil is hydroxyethyl silicone oil.

[0041] (3.2) Put the pretreated coarse rubber powder, modified polyurethane, aramid fiber, antioxidant, deionized water, half of the mass of sulfur, aromatic oil, zinc oxide, and stearic acid into a banbury mixer, mix for 30s at a rotation speed of 100r / min, then add carbon black, antioxidant, silane coupling agent KH-560, and accelerator NS, mix for 50s at a rotation speed of 80r / min, perform discharge treatment on the reaction mixture, cool to room temperature, add the remaining sulfur to the mixed rubber, mix uniformly, perform vulcanization treatment, cool to room temperature, and then shape to obtain the non-pneumatic tire.

[0042] The amount of each raw material is: 100 parts of short fiber-containing coarse rubber powder, 30 parts of styrene-butadiene rubber, 30 parts of modified polyurethane, 80 parts of carbon black, 15 parts of aramid fiber, 5 parts of antioxidant, 6 parts of sulfur, 10 parts of aromatic oil, 3 parts of zinc oxide, 1 part of stearic acid, 5 parts of silane coupling agent KH-560, 4 parts of accelerator NS.

[0043] Example 3

[0044] The method for preparing the non-pneumatic tire from waste tires comprises the following steps:

[0045] (1) Waste tire recycling: clean the contained waste tires, crush the cleaned rubber in a crusher to 20-30mm coarse particles, and remove the iron impurities and coarse rubber particles through first magnetic separation; grind the coarse rubber particles to 5-10mm through a grinding machine, remove the iron impurities through second magnetic separation, and continue to grind to 0.5-1.4mm through a grinding wheel machine, and screen through a filter screen to obtain coarse rubber powder containing short fibers;

[0046] (2) Coarse rubber powder pretreatment: under the conditions of low temperature and anaerobic environment, using swelling solvent as medium and thiol sulfide as desulfurizer, the coarse rubber powder containing short fibers is desulfurized and regenerated at 200℃ and 8Mpa for 1h, and the amount of desulfurizer is 8%;

[0047] The swelling solvent is supercritical carbon dioxide; the thiol sulfide is n-hexyl mercaptan;

[0048] (3) Preparation of non-pneumatic tire:

[0049] (3.1) Stir the hydroxyl-alkyl silicone oil and the vinyl polyether uniformly in the presence of a solvent, heat to 65℃, and stir for 1h in the presence of a catalyst; continue to heat the reaction system to 70℃, and then add diisocyanate, polyol, dimethylol propionic acid chain extender, and triethylamine neutralizer, and continue to stir for 6h; under constant temperature conditions, add a capping agent dropwise, and continue to react for 3-5h to obtain modified polyurethane;

[0050] The diisocyanate is hexamethylene diisocyanate; the polyol is polyester diol with a molecular weight of 600-1000; the catalyst is stannous zinc acetate; the solvent is toluene; and the hydroxyl-alkyl silicone oil is hydroxyl butyl silicone oil.

[0051] (3.2) Take the pretreated coarse rubber powder, modified polyurethane, aramid fiber, antioxidant, deionized water, half the mass of sulfur, aromatic oil, zinc oxide, stearic acid into the internal mixer, mix for 50s at a speed of 60r / min, then add carbon black, antioxidant, silane coupling agent KH-560 and accelerator NS, mix for 30s at a speed of 120r / min, carry out the degassing treatment of the reactants, cool to room temperature, obtain the rubber compound, mix the remaining sulfur uniformly in the rubber compound, carry out the vulcanization treatment, cool to room temperature, shape, and obtain the airless tire.

[0052] The amount of each raw material is: coarse rubber powder containing short fibers 100 parts, styrene-butadiene rubber 40 parts, modified polyurethane 20 parts, carbon black 120 parts, aramid fiber 5 parts, antioxidant 10 parts, sulfur 3 parts, aromatic oil 30 parts, zinc oxide 1 part, stearic acid 3 parts, silane coupling agent KH-560 10 parts, and accelerator NS 8 parts.

[0053] Comparative Example 1

[0054] The method for preparing an airless tire from waste tires comprises the following steps:

[0055] (1) Waste tire recycling: clean the waste tires inside, crush the cleaned rubber into coarse particles of 20-30mm in a crusher, remove the iron impurities and coarse rubber particles through the first magnetic separation, grind the coarse rubber particles to 5-10mm in a grinding machine, remove the iron impurities through the second magnetic separation, continue to grind to 0.5-1.4mm in a grinding wheel machine, and screen through a filter screen to obtain coarse rubber powder containing short fibers;

[0056] (2) Coarse rubber powder pretreatment: under the conditions of low temperature and anaerobic environment, use swelling solvent as medium and thiol sulfide as desulfurizer to regenerate the coarse rubber powder containing short fibers at 160℃ and 12Mpa for 3h, and the amount of desulfurizer is 7%;

[0057] The swelling solvent is supercritical carbon dioxide, and the thiol sulfide is dithiothreitol;

[0058] (3) Preparation of airless tire:

[0059] Take the pretreated coarse rubber powder, polyurethane, aramid fiber, antioxidant, deionized water, half the mass of sulfur, aromatic oil, zinc oxide, stearic acid into the internal mixer, mix for 40s at a speed of 80r / min, then add carbon black, antioxidant, silane coupling agent KH-560 and accelerator NS, mix for 40s at a speed of 100r / min, carry out the degassing treatment of the reactants, cool to room temperature, obtain the rubber compound, mix the remaining sulfur uniformly in the rubber compound, carry out the vulcanization treatment, cool to room temperature, shape, and obtain the airless tire.

[0060] The amounts of the raw materials were as follows: 100 parts of the short fiber-containing crude rubber powder, 35 parts of styrene-butadiene rubber, 25 parts of polyurethane, 100 parts of carbon black, 10 parts of aramid fiber, 7.5 parts of antioxidant, 4.5 parts of sulfur, 20 parts of aromatic oil, 2 parts of zinc oxide, 2 parts of stearic acid, 7.5 parts of silane coupling agent KH-560, and 6 parts of accelerator NS.

[0061] Product properties of Examples 1 to 3 and Comparative Example 1 were tested.

[0062]

[0063]

[0064] It is obvious that the above description of the specific embodiments of the present application does not limit the application of the present application, and various equivalent replacements or modifications can be made according to the actual situation for those skilled in the art. All these replacements or modifications shall belong to the protection scope of the claims attached to the present application as long as they do not deviate from the spirit of the present application.

Claims

1. A method for preparing pneumatic tires using waste tires, characterized in that: Includes the following steps: (1) Waste tire recycling: The waste tires contained in the tires are cleaned, and the cleaned rubber is crushed into coarse particles of 20-30mm in a crusher. The coarse particles are subjected to a first magnetic separation to obtain iron impurities and coarse rubber particles. The coarse rubber particles are ground to 5-10mm in a grinder, and the iron impurities are removed by a second magnetic separation. The particles are then ground to 0.5-1.4mm in a grinding wheel and screened through a filter screen to obtain coarse rubber powder containing short fibers. (2) Pretreatment of coarse rubber powder: Under low temperature and oxygen-free environment, the coarse rubber powder containing short fibers is desulfurized and regenerated at 140-200℃ and 8-18 MPa for 1-6 hours using a swelling solvent as a medium and mercaptan sulfides as desulfurizing agents, with a desulfurization agent dosage of 8-15%. (3) Preparation of pneumatic tires: (3.1) Hydroxyl-terminated silicone oil and vinyl polyether are stirred evenly in the presence of solvent, heated to 55-65℃, and stirred for 1-3 hours in the presence of catalyst; the reaction system is further heated to 70-80℃, and then diisocyanate, polyol, dimethylolpropionic acid chain extender and triethylamine neutralizer are added, and the reaction is stirred for 2-6 hours; under constant temperature conditions, end-capping agent is added dropwise, and the reaction is continued for 3-5 hours to obtain modified polyurethane; (3.2) Take the pretreated coarse rubber powder, modified polyurethane, aramid fiber, antioxidant, deionized water, half the mass of sulfur, aromatic oil, zinc oxide, and stearic acid and put them into a mixer. Mix them at a speed of 60-100 r / min for 30-50 s. Then add carbon black, antioxidant, silane coupling agent KH-560 and accelerator NS. Mix them at a speed of 80-120 r / min for 30-50 s. Remove the reactants and cool them to room temperature to obtain the compound. Add the remaining sulfur to the compound and mix evenly. Perform vulcanization treatment, cool to room temperature, and mold to obtain the pneumatic tire. In step (3.1), the diisocyanate is 2,4-toluene diisocyanate, isophorone diisocyanate, or hexamethylene diisocyanate; the polyol is a polyester diol with a molecular weight of 600-1000 or polypropylene glycol with a molecular weight of 400-2000; the catalyst is dibutyltin dilaurate or stannous zincate; the solvent is methyl ethyl ketone, N,N-dimethylformamide, toluene, and / or N-methylpyrrolidone; and the hydroxyalkyl-terminated silicone oil is hydroxymethyl silicone oil, hydroxyethyl silicone oil, hydroxypropyl silicone oil, or hydroxybutyl silicone oil.

2. The method for preparing pneumatic tires using waste tires according to claim 1, characterized in that: In step (2), the swelling solvent is supercritical carbon dioxide or supercritical ethanol; the thiol sulfide is dithiothreitol, diphenyl disulfide or n-hexanethiol.

3. The method for preparing pneumatic tires using waste tires according to claim 1, characterized in that: In step (3.2), the amounts of each raw material are as follows: 100 parts of coarse rubber powder containing short fibers, 30-40 parts of styrene-butadiene rubber, 20-30 parts of modified polyurethane, 80-120 parts of carbon black, 5-15 parts of aramid fiber, 5-10 parts of antioxidant, 3-6 parts of sulfur, 10-30 parts of aromatic oil, 1-3 parts of zinc oxide, 1-3 parts of stearic acid, 5-10 parts of silane coupling agent KH-560, and 4-8 parts of accelerator NS.

4. The method for preparing pneumatic tires using waste tires according to claim 1, characterized in that: In step (3.2), the amounts of each raw material are as follows: 100 parts of coarse rubber powder containing short fibers, 35 parts of styrene-butadiene rubber, 25 parts of modified polyurethane, 100 parts of carbon black, 10 parts of aramid fiber, 7.5 parts of antioxidant, 4.5 parts of sulfur, 20 parts of aromatic oil, 2 parts of zinc oxide, 2 parts of stearic acid, 7.5 parts of silane coupling agent KH-560, and 6 parts of accelerator NS.

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