Production method of high-strength rubber powder

Abstract

A production method of high-strength rubber powder belongs to the field of rubber powder production, and comprises the following steps: 1, recovering waste tires, removing impurities, and crushing for later use; 2, fully mixing the waste tire powder obtained in the step 1 with 1, 2-polybutadiene, a thermoplastic elastomer, a plasticizer, a cross-linking agent, an inorganic filler, a light stabilizer, an antioxidant and a dispersing agent, and adding the mixture into a refiner for melting and refining; 3, after refining is completed, the mixture is transferred into a melting section of a double-screw extruder for extrusion granulation, and water cooling is adopted for cooling after granulation; and 4, crushing the rubber particles obtained in the step 3, sieving, and sub-packaging to obtain the high-strength rubber powder. The 1, 2-polybutadiene, the thermoplastic elastomer, the plasticizer and the inorganic filler are added and fused and mixed with the waste tires, so that the performance of the rubber powder can be improved; meanwhile, through the light stabilizer and the antioxidant, the light stability and the anti-aging performance of the waste tire material during recycling can be improved.

Description

Technical Field

[0001] The invention belongs to the field of rubber powder production, in particular to a method for producing high-strength rubber powder. Background Art

[0002] Rubber powder is obtained by crushing waste tires as raw materials to achieve the recycling of waste tires. Now rubber powder is widely used in the automotive industry, construction industry, medical industry, sports equipment manufacturing, home decoration, waterproof materials, and chemical industry. However, since rubber powder is produced from waste tires as the main raw material, its performance may vary due to the usage of different waste tires, resulting in poor performance of rubber powder. Therefore, the scope of use of rubber powder is affected and it can only be used in some fields with low performance requirements, thus limiting the use of rubber powder. Summary of the Invention

[0003] The present invention provides a method for producing high-strength rubber powder, which is used to solve the defects in the prior art.

[0004] The present invention is achieved through the following technical solutions:

[0005] A method for producing high-strength rubber powder comprises the following steps:

[0006] Step 1: Recycle waste tires, remove impurities and crush them for later use;

[0007] Step 2: The waste tire powder obtained in step 1 is fully mixed with 1,2-polybutadiene, thermoplastic elastomer, plasticizer, crosslinking agent, inorganic filler, light stabilizer, antioxidant and dispersant, and then added into a refiner for melt refining;

[0008] Step 3: After refining, transfer to the melting section of the twin-screw extruder for extrusion granulation, and use water cooling to cool down after granulation;

[0009] Step 4: Grind the rubber particles obtained in step 3, sieve and pack them to obtain high-strength rubber powder.

[0010] The method for producing high-strength rubber powder as described above comprises the following steps: in the step 1, after the waste tires are recycled, they are first cut into pieces by a block cutter and foreign matter attached to the surface of the waste tires (such as dirt and dust attached to the surface of the waste tires, stones stuck in the tire treads, etc.) is removed; the waste tire pieces obtained by the block cutter are crushed by a rubber crusher, and after crushing, they are passed through a magnetic separator to remove iron impurities (since a layer of wire mesh is generally present in waste tires, a certain amount of steel powder will be present after crushing and needs to be removed) and then set aside.

[0011] A production method of high-strength rubber powder as described above. In step two, the added mass parts of each substance are as follows: 70 - 90 parts of waste tire powder; 8 - 12 parts of 1,2-polybutadiene; 2 - 3 parts of thermoplastic elastomer; 1 - 2 parts of plasticizer; 0.5 - 1 part of crosslinking agent; 3 - 5 parts of inorganic filler; 0.2 - 0.6 part of light stabilizer; 0.2 - 0.4 part of antioxidant; 0.1 - 0.2 part of dispersant.

[0012] A production method of high-strength rubber powder as described above. The thermoplastic elastomer in step two is any one of thermoplastic elastomer SBS, thermoplastic elastomer TPV, and thermoplastic elastomer SEBS;

[0013] The plasticizer is any one of tributyl citrate, acetyl tributyl citrate, and tri-n-octyl trimellitate, or a mixture of any two or more of them in any proportion.

[0014] A production method of high-strength rubber powder as described above. The crosslinking agent is any one of benzoyl peroxide or p-benzoquinone dioxime, or a mixture of the two in any proportion.

[0015] A production method of high-strength rubber powder as described above. The inorganic filler is methylated nano-titanium dioxide.

[0016] A production method of high-strength rubber powder as described above. The light stabilizer is any one of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol or 2-hydroxy-4-n-octyloxybenzophenone, or a mixture of the two in any proportion.

[0017] A production method of high-strength rubber powder as described above. The antioxidant is any one of 2,4-bis(octylthiomethyl)-6-methylphenol or pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], or a mixture of the two in any proportion.

[0018] A production method of high-strength rubber powder as described above. The dispersant is any one of sulfur-phosphorized polyisobutylene polyoxyethylene ester, sodium dodecyl sulfate, and polyethylene glycol, or a mixture of any two or more of them in any proportion.

[0019] A production method of high-strength rubber powder as described above. In step two, the refining temperature of the refining machine is 180 - 190 °C, and the refining time is 1 - 1.5 h.

[0020] In the above-mentioned method for producing high-strength rubber powder, the temperature of the melting section of the twin-screw extruder in step 3 is 190-200°C, and the head temperature of the twin-screw extruder is 180-190°C.

[0021] The advantages of the present invention are as follows: the performance of rubber powder can be improved by adding 1,2-polybutadiene, a thermoplastic elastomer, a plasticizer, and an inorganic filler to the waste tires after melt mixing; the inorganic filler is selected from methylated nano-scale titanium dioxide, which can improve the mechanical properties of the composite material; and the inorganic filler has a high specific surface area and a small grain size, so that the nano-scale titanium dioxide is evenly dispersed in the matrix, thereby enhancing the overall performance of the material; at the same time, the light stability and aging resistance of the waste tire material during recycling can be increased by using a light stabilizer and an antioxidant; at the same time, the crosslinking agent and the dispersant can make the 1,2-polybutadiene, the thermoplastic elastomer, the plasticizer, and the inorganic filler more evenly dispersed in the process of melt mixing with the waste tires, thereby ensuring the performance of the rubber powder. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0023] Example 1

[0024] Step 1: Use a block cutter to cut the waste tires into pieces and remove foreign matter attached to the surface of the waste tires. The waste tire pieces obtained by the block cutter are crushed by a rubber crusher. After crushing, they are passed through a magnetic separator to remove iron impurities and then set aside.

[0025] Step 2: Weigh the following substances according to the following weight ratios: 70 parts of waste tire powder; 8 parts of 1,2-polybutadiene; 2 parts of thermoplastic elastomer TPV; 1 part of acetyl tributyl citrate; 0.5 parts of p-quinone dioxime; 3 parts of methylated nano-scale titanium dioxide; 0.2 parts of 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxyphenol; 0.2 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; and 0.1 parts of sulfurized polyisobutylene polyoxyethylene ester; fully mix the weighed substances, add them into a refiner, and melt-refine them at a temperature of 180°C for 1.5 hours;

[0026] Step 3: After refining, transfer to the melting section of the twin-screw extruder for extrusion granulation. The temperature of the melting section of the twin-screw extruder is 190°C, and the head temperature of the twin-screw extruder is 180°C. After granulation, water cooling is used for cooling.

[0027] Step 4: Grind the rubber particles obtained in step 3, sieve and pack them to obtain high-strength rubber powder.

[0028] Example 2

[0029] Step 1: Use a block cutter to cut the waste tires into pieces and remove foreign matter attached to the surface of the waste tires. The waste tire pieces obtained by the block cutter are crushed by a rubber crusher. After crushing, they are passed through a magnetic separator to remove iron impurities and then set aside.

[0030] Step 2: Weigh the following substances according to the following weight ratios: 90 parts of waste tire powder; 12 parts of 1,2-polybutadiene; 3 parts of thermoplastic elastomer SBS; 1 part of tributyl citrate; 1 part of tri-n-octyl trimellitate; 1 part of dibenzoyl peroxide; 5 parts of methylated nano-sized titanium dioxide; 0.6 parts of 2-hydroxy-4-n-octyloxybenzophenone; 0.4 parts of 2,4-bis(octylthiomethyl)-6-methylphenol; 0.1 parts of sodium lauryl sulfate; and 0.1 parts of polyethylene glycol; fully mix the weighed substances, add them to a refiner, and melt-refine them at 190°C for 1 hour;

[0031] Step 3: After refining, transfer to the melting section of the twin-screw extruder for extrusion granulation. The temperature of the melting section of the twin-screw extruder is 200°C, and the head temperature of the twin-screw extruder is 190°C. After granulation, water cooling is used for cooling.

[0032] Step 4: Grind the rubber particles obtained in step 3, sieve and pack them to obtain high-strength rubber powder.

[0033] Example 3

[0034] Step 1: Use a block cutter to cut the waste tires into pieces and remove foreign matter attached to the surface of the waste tires. The waste tire pieces obtained by the block cutter are crushed by a rubber crusher. After crushing, they are passed through a magnetic separator to remove iron impurities and then set aside.

[0035] Step 2: Weigh each substance according to the following parts by weight: 80 parts of waste tire powder; 10 parts of 1,2-polybutadiene; 2.5 parts of thermoplastic elastomer SEBS; 0.5 part of tributyl citrate; 0.5 part of acetyl tributyl citrate; 0.5 part of tri-n-octyl trimellitate; 0.4 part of dibenzoyl peroxide; 0.3 part of p-benzoquinone dioxime; 4 parts of methylated nanometer titanium dioxide; 0.2 part of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol; 0.2 part of 2-hydroxy-4-n-octyloxybenzophenone; 0.1 part of 2,4-bis(octylthiomethyl)-6-methylphenol; 0.2 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; 0.05 part of sulfurized and phosphated polyisobutylene polyoxyethylene ester; 0.05 part of sodium dodecyl sulfate; 0.05 part of polyethylene glycol; Fully mix the weighed substances and add them to a refining machine to conduct melt refining at a temperature of 185°C for 1.3 h;

[0036] Step 3: After the refining is completed, transfer it to the melting section of a twin-screw extruder for extrusion granulation. The temperature of the melting section of the twin-screw extruder is 195°C, and the temperature of the die head of the twin-screw extruder is 185°C. After granulation, water cooling is used for cooling;

[0037] Step 4: Crush the rubber particles obtained in Step 3, then sieve and package them to obtain high-strength rubber powder.

[0038] Comparative Example 1

[0039] Step 1: First, use a block cutter to cut the waste tire and remove the foreign matters attached to the surface of the waste tire. The waste tire blocks obtained by the block cutter are crushed on a rubber breaker, and after crushing, they are passed through a magnetic separator to remove iron impurities and then reserved;

[0040] Step 2: Weigh each substance according to the following parts by weight: 80 parts of waste tire powder; 10 parts of 1,2-polybutadiene; 0.5 part of tributyl citrate; 0.5 part of acetyl tributyl citrate; 0.5 part of tri-n-octyl trimellitate; 0.4 part of dibenzoyl peroxide; 0.3 part of p-benzoquinone dioxime; 4 parts of methylated nanometer titanium dioxide; 0.2 part of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol; 0.2 part of 2-hydroxy-4-n-octyloxybenzophenone; 0.1 part of 2,4-bis(octylthiomethyl)-6-methylphenol; 0.2 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; 0.05 part of sulfurized and phosphated polyisobutylene polyoxyethylene ester; 0.05 part of sodium dodecyl sulfate; 0.05 part of polyethylene glycol; Fully mix the weighed substances and add them to a refining machine to conduct melt refining at a temperature of 185°C for 1.3 h;

[0041] Step 3: After refining, transfer to the melting section of the twin-screw extruder for extrusion granulation. The temperature of the melting section of the twin-screw extruder is 195°C, and the head temperature of the twin-screw extruder is 185°C. After granulation, water cooling is used for cooling.

[0042] Step 4: Grind the rubber particles obtained in step 3, sieve and pack them to obtain rubber powder.

[0043] Comparative Example 2

[0044] Step 1: Use a block cutter to cut the waste tires into pieces and remove foreign matter attached to the surface of the waste tires. The waste tire pieces obtained by the block cutter are crushed by a rubber crusher. After crushing, they are passed through a magnetic separator to remove iron impurities and then set aside.

[0045] Step 2: Weigh the following substances according to the following weight ratios: 80 parts of waste tire powder; 0.5 parts of tributyl citrate; 0.5 parts of acetyl tributyl citrate; 0.5 parts of trioctyl trimellitate; 0.4 parts of dibenzoyl peroxide; 0.3 parts of p-quinone dioxime; 0.2 parts of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol; 0.2 parts of 2-hydroxy-4-octyloxydiphenyl 0.2 parts of ketone; 0.1 parts of 2,4-bis(octylthiomethyl)-6-methylphenol; 0.2 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; 0.05 parts of sulfurized polyisobutylene polyoxyethylene ester; 0.05 parts of sodium lauryl sulfate; 0.05 parts of polyethylene glycol; after weighing, thoroughly mix all the materials, add them to a refiner, and melt refine at 185°C for 1.3 hours;

[0046] Step 3: After refining, transfer to the melting section of the twin-screw extruder for extrusion granulation. The temperature of the melting section of the twin-screw extruder is 195°C, and the head temperature of the twin-screw extruder is 185°C. After granulation, water cooling is used for cooling.

[0047] Step 4: Grind the rubber particles obtained in step 3, sieve and pack them to obtain rubber powder.

[0048] Comparative Example 3

[0049] Step 1: Use a block cutter to cut the waste tires into pieces and remove foreign matter attached to the surface of the waste tires. The waste tire pieces obtained by the block cutter are crushed by a rubber crusher. After crushing, they are passed through a magnetic separator to remove iron impurities and then set aside.

[0050] Step 2: Weigh each substance according to the following parts by weight: 80 parts of waste tire powder; 10 parts of 1,2-polybutadiene; 0.5 part of tributyl citrate; 0.5 part of acetyl tributyl citrate; 0.5 part of tri-n-octyl trimellitate; 0.4 part of dibenzoyl peroxide; 0.3 part of p-benzoquinone dioxime; 4 parts of methylated nano-titanium dioxide; 0.2 part of 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol; 0.2 part of 2-hydroxy-4-n-octyloxybenzophenone; 0.1 part of 2,4-bis(octylthiomethyl)-6-methylphenol; 0.2 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; 0.05 part of sulfur-phosphorized polyisobutylene polyoxyethylene ester; 0.05 part of sodium dodecyl sulfate; 0.05 part of polyethylene glycol; After weighing, fully mix the substances and add them to a refining machine for melting and refining at a temperature of 185°C for 1.3 h;

[0051] Step 3: After the refining is completed, transfer it to the melting section of a twin-screw extruder for extrusion granulation. The temperature of the melting section of the twin-screw extruder is 195°C, and the temperature of the head of the twin-screw extruder is 185°C. After granulation, water cooling is used for cooling;

[0052] Step 4: Crush the rubber particles obtained in Step 3, then sieve and package them to obtain rubber powder.

[0053] Carry out tensile strength and elongation at break performance tests on the high-strength rubber powder prepared in Examples 1-3, the rubber powder prepared in Comparative Examples 1-3, and the blank control example (waste tires are directly crushed and reserved). (After kneading into sheets and forming films according to the test formula for tensile strength and elongation at break in GB / T 19208-2020 "Vulcanized Rubber Powder", the tensile strength and elongation at break are tested according to GB / T 528-2009 "Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber"). The test results are shown in Table 1.

[0054] Tensile strength (MPa) Elongation at break (%) Example 1 55.1 723 Example 2 54.8 731 Example 3 55.7 747 Comparative Example 1 47.6 626 Comparative Example 2 48.2 589 Comparative Example 3 46.3 597 Blank Control Example 25.3 259

[0055] Table 1

[0056] It can be seen from the data in Table 1 that the high-strength rubber powder prepared in Examples 1-3 of the present invention has good tensile strength and elongation at break compared with the rubber powder prepared in Comparative Examples 1-3, and is far superior to the blank control example in terms of performance compared with the blank control example. Therefore, the present invention can prepare high-strength rubber powder to meet higher performance requirements, so that it can be used in a wider range of fields.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A production method of high-strength rubber powder, characterized in that: The steps include: Step 1: Recycle waste tires, remove impurities and crush them for later use; Step 2: The waste tire powder obtained in step 1 is fully mixed with 1,2-polybutadiene, thermoplastic elastomer, plasticizer, crosslinking agent, inorganic filler, light stabilizer, antioxidant and dispersant, and then added into a refiner for melt refining; Step 3: After refining, transfer to the melting section of the twin-screw extruder for extrusion granulation, and use water cooling to cool down after granulation; Step 4: Grind the rubber particles obtained in step 3, sieve and pack them to obtain high-strength rubber powder.

2. The production method of a high-strength rubber powder according to claim 1, characterized in that: In the step 1, after the waste tires are recycled, they are first cut into pieces by a block cutter and foreign matter attached to the surface of the waste tires is removed. The waste tire pieces obtained by the block cutter are crushed by a rubber crusher, and then passed through a magnetic separator to remove iron impurities and set aside.

3. The production method of a high-strength rubber powder according to claim 1, characterized in that: The added mass proportions of the substances in step 2 are as follows: 70-90 parts of waste tire powder; 8-12 parts of 1,2-polybutadiene; 2-3 parts of thermoplastic elastomer; 1-2 parts of plasticizer; 0.5-1 parts of crosslinking agent; 3-5 parts of inorganic filler; 0.2-0.6 parts of light stabilizer; 0.2-0.4 parts of antioxidant; and 0.1-0.2 parts of dispersant.

4. A production method of a high-strength rubber powder according to claim 1, characterized in that: The thermoplastic elastomer in step 2 is any one of thermoplastic elastomer SBS, thermoplastic elastomer TPV and thermoplastic elastomer SEBS; The plasticizer is any one of tributyl citrate, acetyl tributyl citrate and tri-n-octyl trimellitate, or a mixture of any two or more of them in any proportion.

5. The method for producing high-strength rubber powder according to claim 1, wherein: The cross-linking agent is any one of dibenzoyl peroxide and p-quinone dioxime, or a mixture of the two in any proportion; The inorganic filler is methylated nano-scale titanium dioxide.

6. The production method of a high-strength rubber powder according to claim 1, characterized in that: The light stabilizer is any one of 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxyphenol or 2-hydroxy-4-n-octyloxybenzophenone or a mixture of the two in any proportion.

7. The method for producing high-strength rubber powder according to claim 1, wherein: The antioxidant is any one of 2,4-bis(octylthiomethyl)-6-methylphenol or pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate or a mixture of the two in any proportion; The dispersant is any one of sulfur-phosphorized polyisobutylene polyoxyethylene ester, sodium lauryl sulfate and polyethylene glycol, or a mixture of any two or more of them in any proportion.

8. The production method of a high-strength rubber powder according to claim 1, characterized in that: The refining temperature of the refiner in step 2 is 180-190° C., and the refining time is 1-1.5 hours.

9. The production method of a high-strength rubber powder according to claim 1, characterized in that: The temperature of the melting section of the twin-screw extruder in step 3 is 190-200°C, and the head temperature of the twin-screw extruder is 180-190°C.