An environmentally friendly recycled material

Abstract

The present invention discloses an environmentally friendly recycled material, relating to the field of rubber technology. The environmentally friendly recycled material of the present invention is made from waste steel wire load-bearing tire treads, which are crushed and impurity-removed, then added with an activator and activation-assisting particles, and then regenerated through microwave desulfurization and activation. The activator is a composite of hydroxyl-terminated liquid nitrile rubber and vegetable oil, and the activation-assisting particles are modified carbon nanotubes as carriers, which are adsorbed and loaded with ferric chloride and then grafted with isophorone diisocyanate. The present invention discloses an environmentally friendly recycled material. The addition of the activator and activation-assisting particles effectively eliminates thiol groups on the surface of rubber powder, preventing the reconnection of broken disulfide and polysulfide bonds on the surface of the rubber particles, thereby achieving the purpose of stabilizing the Mooney viscosity.

Description

Technical Field

[0001] The present invention relates to the field of rubber technology, in particular to an environmentally friendly recycled material. Background Art

[0002] With the continuous development and rapid progress of the automotive industry, the accumulation and production of scrap tires have gradually increased, causing serious environmental pollution and resource waste. Consequently, a wealth of technical literature exists in the existing art regarding the recycling of scrap tires, such as thermal cracking of scrap tires to produce products such as oil, fuel gas, and carbon black; and using scrap tires as raw material to produce rubber powder, which is then processed into reclaimed rubber. However, due to a disconnect between new technology development and applied research, the reclaimed rubber industry has consistently struggled with high pollution, high investment, low output, and low profits. In particular, the tightening of national environmental protection requirements in recent years has further increased the challenges faced by reclaimed rubber companies.

[0003] The traditional method of recycling rubber mainly focuses on cutting waste tires, crushing, magnetically separating, and grinding them into rubber powder, and then refining them to obtain recycled rubber. This process is relatively simple, but the surface of the vulcanized rubber powder crushed by the cutting machine has irregular spheres with sharp edges and cracks. During the desulfurization process, the softening oil added as an expansion agent and the cracking oil of the rubber powder itself will fill and wrap the surface of the powder, and the residual thiol groups in the softening oil and cracking oil will reconnect the broken disulfide bonds and polysulfide bonds, making the Mooney value of the reclaimed rubber return to its original value after desulfurization. Summary of the Invention

[0004] In response to the above problems, the purpose of the present invention is to disclose an environmentally friendly recycled material. By adding an activator and activation auxiliary particles, it can effectively eliminate the thiol groups on the surface of the rubber powder, prevent the broken disulfide bonds and polysulfide bonds on the surface of the rubber particles from reconnecting, and thus achieve the purpose of stabilizing the Mooney viscosity.

[0005] Specifically, the present invention provides an environmentally friendly recycled material, which is made from waste steel wire load-bearing tire treads. After crushing and removing impurities, an activator and activation auxiliary particles are added, and microwave desulfurization and activation regeneration are performed. The activator is a composite of terminal hydroxyl liquid nitrile rubber and vegetable oil. The activation auxiliary particles are modified carbon nanotubes as a carrier, which are adsorbed and loaded with ferric chloride and then grafted with isophorone diisocyanate.

[0006] The environmentally friendly recycled material of the present invention uses waste tires as raw materials, which are crushed and then used as an activator with a complex of end-hydroxyl liquid nitrile rubber and vegetable oil. Compared with the traditional production process, the present invention reduces the addition of exogenous oil by adding the end-hydroxyl liquid nitrile rubber, which not only reduces the wrapping of the exogenous oil on the rubber particles, but also reduces to a certain extent the decomposition of the exogenous oil to produce odorous substances during the preparation process. In addition, the vegetable oil used in the present invention is more environmentally friendly. At the same time, the end-hydroxyl liquid nitrile rubber can also react with the surface of the rubber particles to prevent the broken disulfide bonds and polysulfide bonds on the surface of the rubber particles from reconnecting, thereby achieving the purpose of stabilizing the Mooney viscosity. In addition, during the preparation process, the added end-hydroxyl liquid nitrile rubber can also undergo self-crosslinking to form a rubber-like substance, which can increase the compatibility between the recycled material and natural rubber, thereby improving the subsequent utilization performance of the recycled material.

[0007] In addition, the present invention also adds activation auxiliary particles. The modified carbon nanotubes in the activation auxiliary particles have good absorption capacity for electromagnetic waves. Through the addition of activation auxiliary particles, microwave energy can be better utilized during the microwave desulfurization activation process to promote the breaking of carbon-sulfur bonds and disulfide bonds. Then, the surface-grafted isophorone diisocyanate reacts with the thiol groups on the surface of the colloid particles. On the one hand, the thiol groups on the surface of the colloid particles are eliminated, preventing the disulfide bonds and polysulfide bonds that have been broken on the surface of the colloid particles from reconnecting, thereby achieving the purpose of stabilizing the Mooney viscosity. On the other hand, the introduction of isocyanate groups on the recycled materials can effectively improve the adhesion performance of the recycled materials and expand their subsequent usability. By loading ferric chloride on the surface of the modified carbon nanotubes, the coordination effect of ferric chloride can promote the grafting of isophorone diisocyanate on the modified carbon nanotubes.

[0008] Furthermore, the mass ratio of the hydroxyl-terminated liquid nitrile rubber, the vegetable oil, and the activation auxiliary particles is 5:1:1.

[0009] Furthermore, the modified carbon nanotubes are carbon nanotubes modified with titanium nitride quantum dots.

[0010] Furthermore, the preparation method of the recycled material specifically comprises the following steps:

[0011] Crushing: The collected waste tires are cleaned and crushed, magnetically screened, and steel wires are removed to obtain rubber powder;

[0012] Desulfurization and activation: Add activation auxiliary particles to the rubber powder and subject it to microwave radiation treatment until smoke is slight. Add the activator while it is still hot and continue microwave radiation treatment. Then take it out and irradiate it with ultraviolet light, raise the temperature to 200℃ and keep it warm for 30-40 minutes to obtain the desulfurized rubber compound.

[0013] Refining: Add the desulfurized rubber material to the auxiliary materials and mix them on an open mill to obtain recycled rubber sheets. After standing for 4 hours, add the accelerator NS and place it on a flat vulcanizing machine for vulcanization to obtain environmentally friendly recycled materials.

[0014] Furthermore, the auxiliary materials include the following raw materials in parts by weight: 5-8 parts of stearic acid, 10-12 parts of sulfur, 1-3 parts of coumarone, and 1-2 parts of cycloparaffin oil.

[0015] Furthermore, the preparation method of the activation auxiliary particles is as follows: weigh ferric chloride, stir and dissolve it in deionized water to obtain a ferric chloride solution, soak the pretreated modified carbon nanotubes in the ferric chloride solution, ultrasonically disperse them, continue to stir and adsorb for 12-24 hours, take them out and stir and disperse them in N,N-dimethylacetamide according to a solid-liquid ratio of 1:10, add isophorone diisocyanate, heat to 80-85°C, continue to stir and react at a speed of 2000-2500 r / min for 6 hours, filter while hot after the reaction is completed, wash, dry, and grind to obtain activation auxiliary particles.

[0016] Furthermore, the preparation method of the modified carbon nanotubes is as follows: the pretreatment is: 25wt% nitric acid and 30wt% sulfuric acid are stirred and mixed in a volume ratio of 3:1 to obtain a mixed acid solution, the modified carbon nanotubes are stirred and dispersed in the mixed acid solution in a solid-liquid ratio of 1:100g / ml, placed in an ultrasonic oscillator, heated to 70°C, kept warm and continuously shaken for 10 hours, filtered, washed with deionized water to a pH of 6-7, and dried.

[0017] Furthermore, the preparation method of the modified carbon nanotubes is as follows: weighing melamine and adding it to methanol, magnetically stirring at room temperature for 12 hours, adding carbon nanotubes, continuing magnetic stirring for 6 hours, maintaining a constant temperature at 70°C until the methanol is completely volatilized, placing the remaining solid in a muffle furnace, and calcining at 550°C for 4 hours to obtain modified carbon nanotubes.

[0018] Beneficial effects of the present invention:

[0019] The present invention discloses an environmentally friendly recycled material, which eliminates the use of coal tar during the production process and does not generate a large amount of odorous substances during the production process. By adding an activator and activation auxiliary particles, the thiol groups on the surface of the rubber powder can be effectively eliminated, and the broken disulfide bonds and polysulfide bonds on the surface of the rubber particles can be prevented from reconnecting, thereby achieving the purpose of stabilizing the Mooney viscosity. In addition, a rubber-like substance can be formed on the surface of the rubber particles, thereby increasing its compatibility with substances such as recycled rubber and improving its subsequent usability. Compared with traditional production processes, the present invention is greener and more environmentally friendly. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below with reference to specific embodiments:

[0021] The environmentally friendly recycled material of the present invention is made from waste steel wire truck tire treads. After crushing and impurity removal, an activator and activation auxiliary particles are added to desulfurize and activate the regenerated material. The activator is a composite of hydroxyl-terminated liquid nitrile rubber and vegetable oil. The activation auxiliary particles are modified carbon nanotubes as a carrier, which are adsorbed and loaded with ferric chloride and then grafted with isophorone diisocyanate. The modified carbon nanotubes are carbon nanotubes modified with titanium nitride quantum dots. The details are as follows:

[0022] Example 1

[0023] Preparation of modified carbon nanotubes: Weigh 1 g of melamine and add it to 50 ml of methanol. Stir magnetically at room temperature for 12 hours. Add 200 mg of carbon nanotubes and continue stirring magnetically for 6 hours. Keep the temperature at 70°C until the methanol is completely evaporated. Place the remaining solid in a muffle furnace and calcine at 550°C for 4 hours to obtain modified carbon nanotubes.

[0024] Pretreatment: 25 wt% nitric acid and 30 wt% sulfuric acid were stirred and uniformly mixed in a volume ratio of 3:1 to obtain a mixed acid solution. The modified carbon nanotubes were stirred and dispersed in the mixed acid solution at a solid-liquid ratio of 1:100 g / ml. The solution was placed in an ultrasonic oscillator, heated to 70°C, kept warm and continuously shaken for 10 hours, filtered, washed with deionized water to a pH of 6-7, and dried.

[0025] Preparation of activation auxiliary particles: Weigh 25g of ferric chloride and stir and dissolve it in 50ml of deionized water to obtain a ferric chloride solution. Immerse the pretreated modified carbon nanotubes in the ferric chloride solution, ultrasonically disperse them, and continue stirring and adsorbing for 24 hours. Take them out and stir and disperse them in N,N-dimethylacetamide according to a solid-liquid ratio of 1:10. Add 200mmol of isophorone diisocyanate, heat to 85°C, and continue stirring at 2000r / min for 6 hours. After the reaction is completed, filter while hot, wash, dry, and grind to obtain activation auxiliary particles.

[0026] The modified carbon nanotubes are used to prepare recycled materials. The specific preparation method is as follows:

[0027] Crushing: The collected waste tires are cleaned and then coarsely crushed, magnetically separated, and then finely crushed. The steel wire is removed by secondary magnetic separation and passed through a 50-mesh sieve to obtain rubber powder.

[0028] Desulfurization activation: Weigh 10g of rubber powder, add 200mg of activation auxiliary particles to the rubber powder, and perform microwave radiation treatment until light smoke appears. Add 600mg of activator while hot, and continue microwave radiation treatment for 30min. The activator includes 500mg of end-hydroxyl liquid nitrile rubber and 100mg of vegetable oil. The end-hydroxyl liquid nitrile rubber and vegetable oil are quickly stirred and evenly added to the rubber powder. After the microwave treatment is completed, take out the rubber powder and heat it to 200℃ under ultraviolet light irradiation, and keep it warm for 40min to obtain a desulfurized rubber material.

[0029] Refining: Weigh 8 parts by weight of stearic acid, 12 parts by weight of sulfur, 2 parts by weight of coumarone, and 1 part by weight of cycloparaffin oil, stir and mix evenly to obtain auxiliary materials, add 1 g of auxiliary materials to the desulfurized rubber material, and then mix on an open mill to obtain regenerated rubber sheet. After standing for 4 hours, add 200 mg of accelerator NS, place it on a flat vulcanizer for vulcanization, and obtain environmentally friendly recycled materials.

[0030] Example 2

[0031] Preparation of modified carbon nanotubes: Weigh 1.64 g of melamine and add it to 80 ml of methanol. Stir magnetically at room temperature for 12 hours. Add 250 mg of carbon nanotubes and continue magnetic stirring for 6 hours. Keep the temperature at 70°C until the methanol is completely evaporated. Place the remaining solid in a muffle furnace and calcine at 550°C for 4 hours to obtain modified carbon nanotubes.

[0032] Pretreatment: 25 wt% nitric acid and 30 wt% sulfuric acid were stirred and uniformly mixed in a volume ratio of 3:1 to obtain a mixed acid solution. The modified carbon nanotubes were stirred and dispersed in the mixed acid solution at a solid-liquid ratio of 1:100 g / ml. The solution was placed in an ultrasonic oscillator, heated to 70°C, kept warm and continuously shaken for 10 hours, filtered, washed with deionized water to a pH of 6-7, and dried.

[0033] Preparation of activation auxiliary particles: Weigh 40g of ferric chloride and stir and dissolve it in 50ml of deionized water to obtain a ferric chloride solution. Immerse the pretreated modified carbon nanotubes in the ferric chloride solution, ultrasonically disperse them, and continue stirring and adsorbing for 12h. Take them out and stir and disperse them in N,N-dimethylacetamide according to a solid-liquid ratio of 1:10. Add 300mmol of isophorone diisocyanate, heat to 80°C, and continue stirring at 2200r / min for 6h. After the reaction is completed, filter while hot, wash, dry, and grind to obtain activation auxiliary particles.

[0034] The modified carbon nanotubes are used to prepare recycled materials. The specific preparation method is as follows:

[0035] Crushing: The collected waste tires are cleaned and then coarsely crushed, magnetically separated, and then finely crushed. The steel wire is removed by secondary magnetic separation and passed through a 50-mesh sieve to obtain rubber powder.

[0036] Desulfurization activation: Weigh 12g of rubber powder, add 150mg of activation auxiliary particles to the rubber powder, and microwave irradiate until light smoke appears. Add 450mg of activator while hot, and continue microwave irradiation for 30min. The activator includes 375mg of hydroxyl-terminated liquid nitrile rubber and 75mg of vegetable oil. The hydroxyl-terminated liquid nitrile rubber and vegetable oil are quickly stirred and evenly added to the rubber powder. After the microwave treatment is completed, take out the rubber powder and heat it to 200℃ under ultraviolet light irradiation and keep it warm for 35min to obtain a desulfurized rubber.

[0037] Refining: Weigh 5 parts by weight of stearic acid, 11 parts by weight of sulfur, 3 parts by weight of coumarone, and 1 part by weight of cycloparaffin oil, stir and mix evenly to obtain auxiliary materials, add 1.1 g of auxiliary materials to the desulfurized rubber material, and then mix on an open mill to obtain regenerated rubber sheet. After standing for 4 hours, add 150 mg of accelerator NS, place it on a flat vulcanizer for vulcanization, and obtain environmentally friendly recycled materials.

[0038] Example 3

[0039] Preparation of modified carbon nanotubes: Weigh 2 g of melamine and add it to 65 ml of methanol. Stir magnetically at room temperature for 12 hours. Add 200 mg of carbon nanotubes and continue magnetic stirring for 6 hours. Keep the temperature at 70°C until the methanol is completely evaporated. Place the remaining solid in a muffle furnace and calcine at 550°C for 4 hours to obtain modified carbon nanotubes.

[0040] Pretreatment: 25 wt% nitric acid and 30 wt% sulfuric acid were stirred and uniformly mixed in a volume ratio of 3:1 to obtain a mixed acid solution. The modified carbon nanotubes were stirred and dispersed in the mixed acid solution at a solid-liquid ratio of 1:100 g / ml. The solution was placed in an ultrasonic oscillator, heated to 70°C, kept warm and continuously shaken for 10 hours, filtered, washed with deionized water to a pH of 6-7, and dried.

[0041] Preparation of activation auxiliary particles: Weigh 30g of ferric chloride and stir and dissolve it in 50ml of deionized water to obtain a ferric chloride solution. Immerse the pretreated modified carbon nanotubes in the ferric chloride solution, ultrasonically disperse them, and continue stirring and adsorbing for 20 hours. Take them out and stir and disperse them in N,N-dimethylacetamide according to a solid-liquid ratio of 1:10. Add 250mmol of isophorone diisocyanate, heat to 85°C, and continue stirring at 2500r / min for 6 hours. After the reaction is completed, filter while hot, wash, dry, and grind to obtain activation auxiliary particles.

[0042] The modified carbon nanotubes are used to prepare recycled materials. The specific preparation method is as follows:

[0043] Crushing: The collected waste tires are cleaned and then coarsely crushed, magnetically separated, and then finely crushed. The steel wire is removed by secondary magnetic separation and passed through a 50-mesh sieve to obtain rubber powder.

[0044] Desulfurization activation: Weigh 10g of rubber powder, add 250mg of activation auxiliary particles to the rubber powder, and microwave irradiate until light smoke appears. Add 750mg of activator while hot, and continue microwave irradiation for 30min. The activator includes 625mg of hydroxyl-terminated liquid nitrile rubber and 125mg of vegetable oil. The hydroxyl-terminated liquid nitrile rubber and vegetable oil are quickly stirred and evenly added to the rubber powder. After the microwave treatment is completed, take out the rubber powder and heat it to 200℃ under ultraviolet light irradiation, and keep it warm for 30min to obtain a desulfurized rubber.

[0045] Refining: Weigh 6 parts by weight of stearic acid, 10 parts by weight of sulfur, 1 part by weight of coumarone, and 2 parts by weight of cycloparaffin oil, stir and mix evenly to obtain auxiliary materials, add 1.2 g of auxiliary materials to the desulfurized rubber material, and then mix on an open mill to obtain regenerated rubber sheet. After standing for 4 hours, add 220 mg of accelerator NS, place it on a flat vulcanizer for vulcanization, and obtain environmentally friendly recycled materials.

[0046] The environmentally friendly recycled materials prepared in Examples 1 to 3 were stored, and their Mooney viscosities (ML100°C (1+4)) were measured according to (GB / T 13460 2008 Recycled Rubber) at 0 days, 10 days, 20 days, and 30 days. At the same time, the recycled rubber prepared by the existing method was used as a comparative example. The measurement results are as follows:

[0047] 0 days 10 days 20 days 30 days Example 1 71 71 72 74 Example 2 68 69 71 73 Example 3 70 72 73 74 Comparative Example 71 78 85 96

[0048] It can be seen that the Mooney viscosity value of the environmentally friendly recycled material of the present invention is more stable than that of the traditional recycled rubber. Under the condition of storage for the same time, the Mooney viscosity value of the environmentally friendly recycled material of the present invention changes less.

[0049] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents shall be encompassed by the claims of the present invention. Any techniques, shapes, and structures not described in detail herein are well known.

Claims

1. An environmentally friendly recycled material, characterized in that: The recycled material is made from waste steel wire load-bearing tire treads, which are crushed and impurity-removed, and then added with an activator and activation auxiliary particles, and then subjected to microwave desulfurization activation and regeneration. The activator is a composite of hydroxyl-terminated liquid nitrile rubber and vegetable oil. The activation auxiliary particles are made from modified carbon nanotubes as carriers, which adsorb and load ferric chloride and are then grafted with isophorone diisocyanate. The preparation method of the activation auxiliary particles is as follows: ferric chloride is weighed and stirred and dissolved in deionized water to obtain a ferric chloride solution, the pretreated modified carbon nanotubes are immersed in the ferric chloride solution, ultrasonically dispersed, and continuously stirred and adsorbed for 12-24 hours, taken out and stirred and dispersed in N,N-dimethylacetamide at a solid-liquid ratio of 1:10, isophorone diisocyanate is added, the temperature is raised to 80-85° C., and the reaction is continuously stirred at a speed of 2000-2500 r / min for 6 hours. After the reaction is completed, the activated auxiliary particles are filtered while hot, washed, dried, and ground to obtain the activation auxiliary particles. The modified carbon nanotubes are prepared by weighing melamine and adding it to methanol, magnetically stirring the mixture at room temperature for 12 hours, adding carbon nanotubes, continuing magnetic stirring for 6 hours, and maintaining the temperature at 70°C until the methanol is completely volatilized. The remaining solid is placed in a muffle furnace and calcined at 550°C for 4 hours to obtain the modified carbon nanotubes.

2. The environmentally friendly recycled material according to claim 1, characterized in that: The mass ratio of the hydroxyl-terminated liquid nitrile rubber, the vegetable oil, and the activation auxiliary particles is 5:1:

1.

3. The environmentally friendly recycled material according to claim 1, characterized in that: The modified carbon nanotubes are carbon nanotubes modified with titanium nitride quantum dots.

4. An environmentally friendly recycled material according to any one of claims 1 to 3, characterized in that: The preparation method of the recycled material specifically comprises the following steps: Crushing: The collected waste tires are cleaned and crushed, magnetically screened, and steel wires are removed to obtain rubber powder; Desulfurization and activation: Add activation auxiliary particles to the rubber powder and subject it to microwave radiation treatment until smoke is slight. Add the activator while it is still hot and continue microwave radiation treatment. Then take it out and irradiate it with ultraviolet light, raise the temperature to 200℃ and keep it warm for 30-40 minutes to obtain the desulfurized rubber compound. Refining: Add the desulfurized rubber material to the auxiliary materials and mix them on an open mill to obtain recycled rubber sheets. After standing for 4 hours, add the accelerator NS and place it on a flat vulcanizing machine for vulcanization to obtain environmentally friendly recycled materials.

5. The environmentally friendly recycled material according to claim 4, characterized in that: The auxiliary materials include the following raw materials in parts by weight: 5-8 parts of stearic acid, 10-12 parts of sulfur, 1-3 parts of coumarone, and 1-2 parts of cycloparaffin oil.

6. The environmentally friendly recycled material according to claim 5, characterized in that: The pretreatment comprises the following steps: uniformly mixing 25 wt% nitric acid and 30 wt% sulfuric acid in a volume ratio of 3:1 to obtain a mixed acid solution; dispersing the modified carbon nanotubes in the mixed acid solution in a solid-liquid ratio of 1:100 g / ml; placing the modified carbon nanotubes in an ultrasonic oscillator, heating the mixture to 70°C, maintaining the temperature and continuously shaking the mixture for 10 hours, filtering the mixture, washing the mixture with deionized water until the pH value is 6-7, and drying the mixture.