Preparation process of degradable tire material compounded by PBS (Phosphate Buffer Solution) and natural rubber

Abstract

The invention relates to the technical field of tire material preparation, in particular to a preparation process of a degradable tire material compounded by PBS and natural rubber, and raw materials comprise the following components: poly (butylene succinate), natural rubber, a plasticizer, an antioxidant and a reinforcing agent. The components and the proportion are as follows: the proportion of the poly (butylene succinate) is 80 parts, and the molecular weight is 80,000-150,000 Da; the proportion of the natural rubber is 15 parts; the plasticizer is dioctyl phthalate, and the proportion of the plasticizer is 3 parts; the antioxidant is hindered phenol, and the proportion is 1 part; the reinforcing agent is white carbon black, the proportion is 1 part, the pretreated raw materials are sequentially added into an internal mixer for mixing, then the white carbon black is added for continuous mixing to achieve primary fusion, then the mixture is transferred to an open mill for continuous mixing to eliminate agglomeration, finally, the materials are cut into blanks, the blanks are put into a preheating mold of a press vulcanizer for vulcanization, and natural cooling is conducted after pressure relief; the invention aims to solve the problems of lack of environmental protection property, prominent contradiction between performance and environmental protection and the like of the existing tire material of the existing material.

Description

Technical Field

[0001] The invention relates to the technical field of tire material preparation, in particular to a process for preparing a degradable tire material composited with PBS and natural rubber. Background Art

[0002] Tire materials are a general term for various materials used to manufacture tires, including treads, sidewalls, carcasses and other components. Their core functions are to support vehicle weight, transmit driving and braking forces, and cushion road impacts. They must also possess properties such as wear resistance, aging resistance, high and low temperature resistance, high strength, and high elasticity.

[0003] Existing tires are mostly made of non-degradable synthetic rubber, such as styrene-butadiene rubber and butadiene rubber. Once discarded, they are difficult to degrade in the natural environment, resulting in large accumulations that cause pollution. Furthermore, recycling requires high-temperature incineration or landfill, which wastes resources and pollutes the environment. Moreover, it is difficult to strike a balance between performance and environmental protection. If high strength and high wear resistance are pursued, it is necessary to rely on a high proportion of non-degradable ingredients and reinforcing agents, sacrificing environmental protection. If degradable materials are tried, such as pure starch-based and pure PBS, there will be problems such as low strength, poor elasticity, and insufficient wear resistance, which cannot meet the needs of tire use. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation process of a degradable tire material composited with PBS and natural rubber, which solves the problems of existing tire materials such as lack of environmental protection and prominent contradiction between performance and environmental protection.

[0005] To achieve the above object, the present invention provides the following technical solution: a process for preparing a biodegradable tire material composited with PBS and natural rubber, wherein the raw materials include the following components: polybutylene succinate, natural rubber, a plasticizer, an antioxidant, and a reinforcing agent; the components and the proportions are as follows: the polybutylene succinate is in an amount of 80 parts, with a molecular weight of 80,000-150,000 Da; the natural rubber is in an amount of 15 parts; the plasticizer is dioctyl phthalate, in an amount of 3 parts; the antioxidant is a hindered phenol, in an amount of 1 part; and the reinforcing agent is white carbon black, in an amount of 1 part; The following steps are also included: Step 1: Drying pretreatment of raw materials; Step 2: Raw material plastication pretreatment; Step 3: Preliminary mixing; Step 4: Fine mixing; Step 5: Molding and vulcanization.

[0006] Preferably, the polybutylene succinate is passed through an 80-mesh sieve, and 80 parts of the polybutylene succinate particles are placed in a blast drying oven with a set temperature of 85°C and an air volume of 100 m 3 / h, dry for 4h.

[0007] Preferably, the natural rubber is cut into 5 cm×5 cm blocks, and the surface oil is removed. 15 portions of the natural rubber blocks are placed in an open mill, with the initial roller spacing adjusted to 0.5 mm, the roller speed 18 r / min, and the mixture is masticated at room temperature for 12 min.

[0008] Preferably, the white carbon black is passed through a 120-mesh sieve; the antioxidant 1010 and the plasticizer DOP are dried in an oven at 40° C. for 1 hour.

[0009] Preferably, the dried PBS (80 parts), the plasticized natural rubber (15 parts), the plasticizer DOP (3 parts), and the antioxidant 1010 (1 part) are sequentially added to the internal mixer, the feed port is closed, and the parameters are set: temperature 125°C, rotor speed 70r / min, pressure 0.4MPa, mixing for 8 minutes, then adding white carbon black (1 part), continuing mixing for 4 minutes, and discharging the material.

[0010] Preferably, the material after internal mixing is transferred to an open mill, the initial roller gap is adjusted to 1.5 mm, the roller speed is 16 r / min and 19.2 r / min, the cooling system is turned on, the material is repeatedly turned over 5 times, the roller gap is gradually adjusted to 0.8 mm, and mixing is continued for 15 minutes.

[0011] Preferably, the finely mixed material is cut into blanks that match the tire component mold and placed in a preheated mold of a flat vulcanizer for vulcanization. After vulcanization, the pressure is released and the mold is opened, and the molded tire material is taken out and naturally cooled to room temperature.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The ring of the present invention is made by compounding biodegradable polybutylene succinate (PBS) with natural rubber. It can be naturally degraded after being discarded, thus solving the pollution caused by the non-degradability of traditional materials. It also has balanced performance. Through the reinforcement of white carbon black and the addition of antioxidants, it retains the elasticity of natural rubber while improving its strength and wear resistance. At the same time, the process is efficient and stable. After refined pretreatment and scientific feeding sequence, the raw materials are evenly dispersed, and there are no defects such as bubbles and lumps during processing. The batch production has a high pass rate. In addition, the antioxidant effectively inhibits aging and extends the service life, taking into account the requirements of environmental protection, performance and production practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0014] To make the purpose, 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 drawings in the embodiments of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0015] The invention provides a preparation process of a biodegradable tire material composited with PBS and natural rubber. The raw materials include the following components: polybutylene succinate, natural rubber, a plasticizer, an antioxidant, and a reinforcing agent. The components and the proportions are as follows: polybutylene succinate is in an amount of 80 parts, with a molecular weight of 80,000-150,000 Da; natural rubber is in an amount of 15 parts; the plasticizer is dioctyl phthalate, in an amount of 3 parts; the antioxidant is a hindered phenol, in an amount of 1 part; and the reinforcing agent is white carbon black, in an amount of 1 part. The following steps are also included: Step 1: Drying pretreatment of raw materials; Step 2: Raw material plastication pretreatment; Step 3: Preliminary mixing; Step 4: Fine mixing; Step 5: Molding and vulcanization; The polybutylene succinate is prepared using the company's C4 platform technology: agricultural straw is used as raw material, and succinic acid is produced through a two-step fermentation (fermentation conversion rate ≥92%), which is then obtained through esterification and polycondensation. The molecular weight is 80,000-150,000 Da, the carbon footprint is ≤-3.0tCO2 / ton, and the production cost is ≤8,800 yuan / ton. The polybutylene succinate has a molecular weight of 80,000-150,000 Da, a melting point of 110-120°C, a purity of ≥99%, a moisture content of ≤0.1%, and a 6-month soil degradation rate of ≥60%; the natural rubber Mooney viscosity (ML1+4, 100°C) is 40-60, the volatile matter is ≤0.8%, the ash content is ≤0.5%, and the nitrogen content is 2.8-3.0%; the purity of dioctyl phthalate is ≥99%, and the density is 0.98-0.99g / cm 3 , flash point ≥210℃, volatile matter ≤0.1%; antioxidant purity ≥98%, melting point 110-115℃, volatile matter ≤0.5%, antioxidant efficiency ≥90% (100℃ accelerated aging test); white carbon black particle size 15-20μm, specific surface area 150-200m 2 / g, pH value 6.5-7.5, oil absorption value ≥2.0mL / g.

[0016] Pass the polybutylene succinate through an 80-mesh sieve, and place 80 parts of polybutylene succinate granules into a blast drying oven with a set temperature of 85°C and an air volume of 100 m 3 / h, drying for 4h; Use a blast drying oven, the model of which is GZX-9070MBE. Its setting parameters are: temperature control range room temperature - 200 ° C, temperature accuracy ± 1 ° C, air volume adjustable (50-200m 3 / h), the inner tank is made of 304 stainless steel, which removes moisture from PBS particles (to avoid bubbles during processing) and ensures that the moisture content is ≤0.1% (detected by Karl Fischer titrator).

[0017] Cut the natural rubber into 5cm×5cm blocks, remove the oil from the surface, put 15 pieces of natural rubber blocks into the open mill, adjust the initial roller gap to 0.5mm, the roller speed to 18r / min, and masticate at room temperature for 12min; The model of the mixing mill is XK-160, with a roller diameter of 160 mm, a roller gap adjustment range of 0.1-5 mm, a roller speed of 16-20 r / min, and electric heating (room temperature - 150 ° C). The initial roller gap is adjusted to 0.5 mm, the roller speed is 18 r / min, and the mixing is performed at room temperature for 12 minutes. The material is turned over every 3 minutes until the Mooney viscosity drops to 30-35 (ML1+4, 100 ° C). Mechanical shearing is used to reduce the molecular weight of natural rubber and improve its plasticity, which is convenient for subsequent mixing with PBS.

[0018] The white carbon black was passed through a 120 mesh sieve; the antioxidant 1010 and the plasticizer DOP were dried in an oven at 40°C for 1 h; Control particle size distribution, remove moisture, and enhance interfacial bonding with the substrate.

[0019] Dried PBS (80 parts), masticated natural rubber (15 parts), plasticizer DOP (3 parts), and antioxidant 1010 (1 part) were added to the internal mixer in sequence. The feed port was closed and the parameters were set as follows: temperature 125°C, rotor speed 70 r / min, pressure 0.4 MPa, and mixing for 8 minutes. Then, white carbon black (1 part) was added and mixing continued for 4 minutes. The material was discharged. The internal mixer model is XSM-50, with a working volume of 50L, a rotor speed of 30-100r / min, a temperature control range of room temperature-200℃, and a pressure of 0.3-0.6MPa. It can efficiently mix multiple raw materials in a closed environment and achieve preliminary compatibility of PBS melt and natural rubber through high temperature and shear force.

[0020] The mixed material was transferred to an open mill, the initial roller gap was adjusted to 1.5 mm, the roller speed was 16 r / min and 19.2 r / min, the cooling system was turned on, the material was repeatedly turned over 5 times, the roller gap was gradually adjusted to 0.8 mm, and mixing was continued for 15 min; The model of the open mill is XK-250, the roller diameter is 250 mm, the roller gap adjustment range is 0.1-10 mm, the roller speed ratio is 1:1.2, the cooling system (water temperature ≤ 25 ° C), the initial roller gap is adjusted to 1.5 mm, the roller speed is 16 r / min (front roller), 19.2 r / min (rear roller), further disperse the raw materials, eliminate agglomerates through the shear force of the rollers, and make the white carbon black, antioxidants, etc. evenly distributed in the matrix. Mixing is carried out for 15 minutes, during which samples are taken for observation (the surface of the material is smooth, without white spots or lumps).

[0021] The finely mixed material is cut into blanks that match the tire component mold and placed in the preheated mold of the flat vulcanizer for vulcanization. After the vulcanization is completed, the pressure is released and the mold is opened. The molded tire material is taken out and naturally cooled to room temperature; The flatbed vulcanizing press model is XLB-D400×400×2, with a working pressure of 10-20MPa. The mold is preheated to 135°C, the heating temperature is room temperature-200°C, the hot plate size is 400×400mm, and the pressure holding accuracy is ±0.1MPa. The material is shaped in the mold, and high temperature and high pressure promote intermolecular cross-linking to improve the structural stability and mechanical properties of the material. It is naturally cooled to room temperature for about 30 minutes. Under high temperature and high pressure, PBS and natural rubber molecules form a partially cross-linked structure. At the same time, the mold gives the material a specific shape such as sidewall and tread segments, and finally a tire material with both biodegradability and mechanical properties is obtained.

[0022] Working principle: Biodegradable polybutylene succinate (PBS, 80 parts) is used as the matrix to provide basic structure and biodegradability, and is screened with an 80-mesh sieve and dried at 85℃ for 4 hours to remove moisture and impurities; natural rubber (15 parts) is cut to remove oil and dirt, and then plasticized at room temperature for 12 minutes on an open mill (roller spacing 0.5mm, roller speed 18r / min) to reduce the molecular weight to improve plasticity, forming an interpenetrating network with PBS to supplement elasticity; plasticizer DOP (3 parts) promotes the compatibility of the two, white carbon black (120-mesh sieve treatment, 1 part) is used to reinforce and improve strength and wear resistance, and antioxidant 1010 (dried at 40℃ for 1 hour, 1 part) to inhibit oxidative aging; during processing, the pretreated raw materials are first added to an internal mixer (125°C, 70r / min, 0.4MPa) and mixed for 8 minutes, and then white carbon black is added and mixed for 4 minutes to achieve preliminary fusion. Subsequently, the raw materials are transferred to an open mixer (initial roller spacing 1.5mm, roller speed 16r / min and 19.2r / min). After 5 turnovers, the roller spacing is adjusted to 0.8mm and the mixing is continued for 15 minutes to eliminate agglomeration. Finally, the material is cut into billets and placed in a flat vulcanizer preheating mold for vulcanization. After pressure relief, it is naturally cooled to finally form a tire material with biodegradability, elasticity, strength and aging resistance.

[0023] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a biodegradable tire material composited with PBS and natural rubber, wherein the raw materials include the following components: polybutylene succinate, natural rubber, a plasticizer, an antioxidant, and a reinforcing agent; The ingredients and proportions are as follows: polybutylene succinate is in an amount of 80 parts, with a molecular weight of 80,000-150,000 Da; natural rubber is in an amount of 15 parts; the plasticizer is dioctyl phthalate, with a proportion of 3 parts; the antioxidant is hindered phenol, with a proportion of 1 part; the reinforcing agent is white carbon black, with a proportion of 1 part; The following steps are also included: Step 1: Drying pretreatment of raw materials; Step 2: Raw material plastication pretreatment; Step 3: Preliminary mixing; Step 4: Fine mixing; Step 5: Molding and vulcanization.

2. The process for preparing a degradable tire material composited with PBS and natural rubber according to claim 1, wherein: The polybutylene succinate was passed through an 80-mesh sieve, and 80 parts of the polybutylene succinate particles were placed in a blast drying oven with a set temperature of 85°C and an air volume of 100 m 3 / h, dry for 4h.

3. The process for preparing a degradable tire material composited with PBS and natural rubber according to claim 1, wherein: The natural rubber was cut into 5 cm×5 cm blocks, and the surface oil was removed. 15 portions of the natural rubber blocks were placed in an open mill, with the initial roller spacing adjusted to 0.5 mm and the roller speed set to 18 r / min, and the rubber was masticated at room temperature for 12 minutes.

4. The process for preparing a degradable tire material composite of PBS and natural rubber according to claim 1, wherein: The white carbon black was passed through a 120-mesh sieve; the antioxidant 1010 and the plasticizer DOP were dried in an oven at 40° C. for 1 hour.

5. The process for preparing a degradable tire material composited with PBS and natural rubber according to claim 1, wherein: The dried PBS (80 parts), the plasticized natural rubber (15 parts), the plasticizer DOP (3 parts), and the antioxidant 1010 (1 part) were added to the internal mixer in sequence, the feed port was closed, and the parameters were set as follows: temperature 125°C, rotor speed 70 r / min, pressure 0.4 MPa, and mixing for 8 minutes. Subsequently, white carbon black (1 part) was added, mixing was continued for 4 minutes, and the material was discharged.

6. The process for preparing a degradable tire material composited with PBS and natural rubber according to claim 5, characterized in that: The mixed material was transferred to an open mixing mill, the initial roller gap was adjusted to 1.5 mm, the roller speed was 16 r / min and 19.2 r / min, the cooling system was turned on, the material was repeatedly turned over 5 times, the roller gap was gradually adjusted to 0.8 mm, and mixing was continued for 15 minutes.

7. The process for preparing a degradable tire material composited with PBS and natural rubber according to claim 1, characterized in that: The finely mixed material is cut into blanks that match the tire component mold and placed in the preheated mold of the flat vulcanizer for vulcanization. After vulcanization is completed, the pressure is released and the mold is opened. The molded tire material is taken out and naturally cooled to room temperature.

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