Regeneration method of waste rubber

Abstract

The invention belongs to the technical field of regenerated rubber, and provides a regeneration method of waste rubber. The method comprises the following steps: shearing waste rubber to obtain waste rubber powder; the method comprises the following steps: mixing the waste rubber powder, a softening agent, an activating agent and an anti-aging agent, reacting, and internally mixing after the reaction is finished to obtain the regenerated rubber. According to the method, the waste rubber is regenerated in a mode of combining physical and mechanical shearing at room temperature and chemical reaction at high temperature. Wherein the integrity of a main chain structure can be kept as far as possible in a physical and mechanical shearing mode at room temperature, the regeneration speed can be increased through a chemical reaction at high temperature, and sufficient regeneration of rubber is guaranteed; the two components cooperate with each other, so that the regeneration effect of the rubber is improved to a great extent. The finally prepared regenerated rubber has excellent strength and toughness.

Description

Technical Field

[0001] The invention relates to the technical field of recycled rubber, in particular to a method for recycling waste rubber. Background Art

[0002] Rubber recycling can turn waste rubber products into usable rubber materials, thereby saving resources and reducing the consumption of natural resources. In addition, recycled rubber materials can greatly reduce the generation of waste, thereby reducing the environmental burden and pollution to the natural environment. Therefore, recycling waste rubber is considered an important part of high-quality sustainable development and circular economy. By recycling waste rubber, the shortage of rubber resources can be effectively alleviated, the ecological environment can be protected, and the sustainable and healthy development of the industry can be promoted.

[0003] However, existing rubber recycling methods often have defects such as high energy consumption, the need to use toxic and harmful treatment agents, and serious environmental damage. In addition, the desulfurization degree, strength, and toughness of the recycled rubber products produced are poor, making it difficult to meet the rubber performance requirements of high-quality products. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems existing in the prior art and provide a method for regenerating waste rubber.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for regenerating waste rubber, comprising the following steps:

[0007] The waste rubber is sheared to obtain waste rubber powder; the waste rubber powder, a softener, an activator and an antioxidant are mixed and reacted, and after the reaction is completed, the mixture is mixed to obtain recycled rubber.

[0008] Preferably, the waste rubber includes waste tire rubber, waste EPDM rubber or waste butyl rubber.

[0009] Preferably, the shearing temperature is 20-30° C., and the shearing time is 10-30 min.

[0010] Preferably, the softener comprises coconut shell, linseed oil, glycerin, trioctyl citrate and rosin; the mass ratio of the coconut shell, linseed oil, glycerin, trioctyl citrate and rosin is 10-18:3-7:3-7:3-7:0.5-2.

[0011] Preferably, the activator comprises 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol, and the mass ratio of 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol is 1-5:1-5:1-5.

[0012] Preferably, the antioxidant includes antioxidant DOP, antioxidant MB and antioxidant DNP; the mass ratio of the antioxidant DOP, antioxidant MB and antioxidant DNP is 1-5:1-5:1-5.

[0013] Preferably, the mass ratio of the waste rubber powder, softener, activator and antioxidant is 90-110:10-30:3-10:1-5.

[0014] Preferably, the reaction temperature is 110-190° C., and the reaction time is 0.5-5 h.

[0015] Preferably, the banburying temperature is 120-190° C., the banburying speed is 50-150 r / min, and the banburying time is 5-20 min.

[0016] The beneficial effects of the present invention are:

[0017] The present invention provides a method for regenerating waste rubber, comprising the following steps: shearing the waste rubber to obtain waste rubber powder; mixing the waste rubber powder, a softener, an activator and an antioxidant, reacting, and performing banburying after the reaction to obtain regenerated rubber. The present invention adopts a method combining physical and mechanical shearing at room temperature with chemical reaction at high temperature to regenerate the waste rubber. The physical and mechanical shearing at room temperature can maintain the integrity of the main chain structure as much as possible, and the chemical reaction at high temperature can increase the regeneration speed and ensure the full regeneration of the rubber; the two work together to greatly improve the regeneration effect of the rubber. The regenerated rubber finally prepared by the present invention has excellent strength and toughness. DETAILED DESCRIPTION

[0018] The present invention provides a method for regenerating waste rubber, comprising the following steps:

[0019] The waste rubber is sheared to obtain waste rubber powder; the waste rubber powder, a softener, an activator and an antioxidant are mixed and reacted, and after the reaction is completed, the mixture is mixed to obtain recycled rubber.

[0020] In the present invention, the waste rubber preferably includes waste tire rubber, waste EPDM rubber or waste butyl rubber.

[0021] In the present invention, shearing is preferably carried out in an open mill, and the shearing temperature is preferably 20-30°C, more preferably 22-28°C, and more preferably 25-26°C; the shearing time is preferably 10-30 min, more preferably 15-25 min, and more preferably 18-20 min.

[0022] In the present invention, the softener preferably includes coconut shell, linseed oil, glycerin, trioctyl citrate and rosin; the mass ratio of the coconut shell, linseed oil, glycerin, trioctyl citrate and rosin is preferably 10-18:3-7:3-7:3-7:0.5-2, more preferably 12-16:4-6:4-6:4-6:1-1.5, more preferably 14-15:5-5.5:5-5.5:5-5.5:1.2-1.3.

[0023] In the present invention, the activator preferably includes 1-hexanethiol, 1-pentanethiol and dithioerythritol, and the mass ratio of 1-hexanethiol, 1-pentanethiol and dithioerythritol is preferably 1-5:1-5:1-5, further preferably 2-4:2-4:2-4, and more preferably 2.5-3:2.5-3:2.5-3.

[0024] In the present invention, the antioxidant preferably includes antioxidant DOP, antioxidant MB and antioxidant DNP; the mass ratio of the antioxidant DOP, antioxidant MB and antioxidant DNP is preferably 1-5:1-5:1-5, more preferably 2-4:2-4:2-4, and more preferably 3:3:3.

[0025] In the present invention, the mass ratio of the waste rubber powder, softener, activator and antioxidant is preferably 90-110:10-30:3-10:1-5, more preferably 95-105:15-25:5-8:2-4, and more preferably 100-103:20-23:6-7:3-3.5.

[0026] In the present invention, the reaction temperature is preferably 110-190°C, more preferably 130-170°C, more preferably 150-160°C; the reaction time is preferably 0.5-5h, more preferably 1.5-4h, more preferably 2.5-3h.

[0027] In the present invention, after the reaction is completed, the system is water-cooled and then banburying is performed; the temperature of the water used for water-cooling is preferably 10 to 20°C, more preferably 12 to 18°C, and more preferably 15 to 16°C; the target temperature of the water-cooling is preferably ≤60°C, more preferably ≤55°C, and more preferably ≤50°C.

[0028] In the present invention, the banburying temperature is preferably 120-190°C, more preferably 140-170°C, and more preferably 150-160°C; the banburying speed is preferably 50-150r / min, more preferably 70-130r / min, and more preferably 100-110r / min; the banburying time is preferably 5-20min, more preferably 10-15min, and more preferably 12-13min.

[0029] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0030] Example 1

[0031] In this embodiment, the softener includes coconut shell, linseed oil, glycerin, trioctyl citrate and rosin, and the mass ratio of coconut shell, linseed oil, glycerin, trioctyl citrate and rosin is 15:5:5.5:5:1.2; the activator includes 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol, and the mass ratio of 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol is 2.5:2.5:3; the antioxidant includes antioxidant DOP, antioxidant MB and antioxidant DNP, and the mass ratio of antioxidant DOP, antioxidant MB and antioxidant DNP is 3:3:3;

[0032] The waste tire rubber was sheared at 25°C in an open mill, and the shearing time was set to 20 minutes to obtain waste rubber powder; the waste rubber powder, softener, activator and antioxidant were mixed (the mass ratio of waste rubber powder, softener, activator and antioxidant was 103:23:7:3), and reacted in a reactor at 160°C, and the reaction time was set to 2.5 hours. After the reaction, the system was water-cooled (the temperature of the water for water-cooling was 15°C, and the target temperature of the water-cooling was 60°C), and finally mixed at 150°C, and the mixing speed was set to 100r / min for 13 minutes to obtain recycled rubber.

[0033] Example 2

[0034] In this embodiment, the softener includes coconut shell, linseed oil, glycerin, trioctyl citrate and rosin, and the mass ratio of coconut shell, linseed oil, glycerin, trioctyl citrate and rosin is 12:4:4:4:1.5; the activator includes 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol, and the mass ratio of 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol is 3:3:2; the antioxidant includes antioxidant DOP, antioxidant MB and antioxidant DNP, and the mass ratio of antioxidant DOP, antioxidant MB and antioxidant DNP is 2:2:3;

[0035] The waste tire rubber was sheared at 28°C in an open mill, and the shearing time was set to 18 minutes to obtain waste rubber powder; the waste rubber powder, softener, activator and antioxidant were mixed (the mass ratio of waste rubber powder, softener, activator and antioxidant was 95:15:5:2), and reacted in a reactor at 130°C, and the reaction time was set to 4 hours. After the reaction, the system was water-cooled (the temperature of the water for water-cooling was 18°C, and the target temperature of the water-cooling was 60°C), and finally mixed at 160°C, and the mixing speed was set to 110r / min for 12 minutes to obtain recycled rubber.

[0036] Example 3

[0037] In this embodiment, the softener includes coconut shell, linseed oil, glycerin, trioctyl citrate and rosin, and the mass ratio of coconut shell, linseed oil, glycerin, trioctyl citrate and rosin is 16:6:5:6:1.3; the activator includes 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol, and the mass ratio of 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol is 2:2:2.5; the antioxidant includes antioxidant DOP, antioxidant MB and antioxidant DNP, and the mass ratio of antioxidant DOP, antioxidant MB and antioxidant DNP is 4:4:3;

[0038] The waste tire rubber was sheared at 22°C in an open mill, and the shearing time was set to 25 minutes to obtain waste rubber powder; the waste rubber powder, softener, activator and antioxidant were mixed (the mass ratio of waste rubber powder, softener, activator and antioxidant was 105:25:8:3.5), and reacted in a reactor at 170°C, and the reaction time was set to 1.5 hours. After the reaction, the system was water-cooled (the temperature of the water for water-cooling was 10°C, and the target temperature of the water-cooling was 50°C), and finally, it was mixed at 170°C, and the mixing speed was set to 130r / min for 10 minutes to obtain recycled rubber.

[0039] Example 4

[0040] The other conditions in Example 1 were kept unchanged, and the composition of the softener was modified to be coconut shell, glycerin and rosin, and the mass ratio of coconut shell, glycerin and rosin was 15:5.5:1.2 to obtain recycled rubber.

[0041] Example 5

[0042] The other conditions in Example 1 were kept unchanged, and the activator was changed to single 1-hexanethiol to obtain regenerated rubber.

[0043] Example 6

[0044] The other conditions in Example 1 remain unchanged, and the antioxidant is changed to a single antioxidant DOP to obtain regenerated rubber.

[0045] Comparative Example 1

[0046] The other conditions in Example 1 are kept unchanged, and the step of shearing the waste rubber is omitted to obtain the recycled rubber.

[0047] Comparative Example 2

[0048] The other conditions in Example 1 are kept unchanged, and the addition of the softener is omitted to obtain the regenerated rubber.

[0049] Comparative Example 3

[0050] The other conditions in Example 1 are kept unchanged, and the addition of the activator is omitted to obtain the regenerated rubber.

[0051] The reclaimed rubbers prepared in Examples 1 to 6 and Comparative Examples 1 to 3 were subjected to performance tests, wherein the test standard was based on the national standard GB / T 13460-2008; the performance test results of different reclaimed rubbers were obtained through the tests, as shown in Table 1.

[0052] Table 1 Performance test results of different recycled rubber

[0053]

[0054]

[0055] It can be seen from the above embodiments that the present invention provides a method for regenerating waste rubber, comprising the following steps: shearing the waste rubber to obtain waste rubber powder; mixing the waste rubber powder, a softener, an activator and an antioxidant, reacting, and performing banburying after the reaction to obtain regenerated rubber. The present invention adopts a combination of physical and mechanical shearing at room temperature and chemical reaction at high temperature to regenerate the waste rubber. The physical and mechanical shearing at room temperature can maintain the integrity of the main chain structure as much as possible, and the chemical reaction at high temperature can increase the regeneration speed and ensure the full regeneration of the rubber; the two cooperate with each other and greatly improve the regeneration effect of the rubber. The regenerated rubber finally prepared by the present invention has excellent strength and toughness. In addition, the present invention reasonably sets the composition of the softener, activator and antioxidant and their ratios, so that the various raw materials cooperate with each other, further ensuring that the obtained regenerated rubber has excellent performance.

[0056] The above is only 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 principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for regenerating waste rubber, characterized in that: It includes the following steps: The waste rubber is sheared to obtain waste rubber powder; the waste rubber powder, a softener, an activator and an antioxidant are mixed and reacted, and after the reaction is completed, the mixture is mixed to obtain recycled rubber.

2. The method for recycling waste rubber according to claim 1, characterized in that: The waste rubber includes waste tire rubber, waste EPDM rubber or waste butyl rubber.

3. The method for recycling waste rubber according to claim 1 or 2, characterized in that: The shearing temperature is 20-30° C., and the shearing time is 10-30 min.

4. The method for recycling waste rubber according to claim 3, characterized in that: The softener comprises coconut shell, linseed oil, glycerin, trioctyl citrate and rosin; the mass ratio of the coconut shell, linseed oil, glycerin, trioctyl citrate and rosin is 10-18:3-7:3-7:3-7:0.5-2.

5. The method for recycling waste rubber according to claim 4, characterized in that: The activator comprises 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol, and the mass ratio of 1-hexyl mercaptan, 1-pentyl mercaptan and dithioerythritol is 1-5:1-5:1-5.

6. The method for recycling waste rubber according to claim 5, characterized in that: The antioxidants include antioxidant DOP, antioxidant MB and antioxidant DNP; the mass ratio of the antioxidant DOP, antioxidant MB and antioxidant DNP is 1-5:1-5:1-5.

7. The method for recycling waste rubber according to claim 1 or 6, characterized in that: The mass ratio of the waste rubber powder, the softener, the activator and the antioxidant is 90-110:10-30:3-10:1-5.

8. The method for recycling waste rubber according to claim 7, characterized in that: The reaction temperature is 110-190° C., and the reaction time is 0.5-5 h.

9. The method for recycling waste rubber according to claim 8, characterized in that: The temperature of the banburying is 120-190° C., the speed of the banburying is 50-150 r / min, and the time of the banburying is 5-20 min.

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