Automobile interior environment-friendly PVC (polyvinyl chloride) synthetic leather with low VOC (volatile organic compound) emission and preparation process

Abstract

The invention discloses automobile interior environment-friendly PVC synthetic leather with low VOC emission and a preparation technology, and relates to the field of high polymer new materials, the technology comprises the steps of mixing linen fibers and PLA fibers, and using a bio-based surface treating agent to improve the compatibility with PVC resin. And mixing the mixture with a stabilizer and a physical foaming agent, and curing and molding at proper temperature and pressure to form the synthetic leather. In order to solve the problem of VOC emission in automotive interior materials, low VOC emission is realized through an innovative PVC synthetic leather preparation process. By adopting a bio-based material and a physical foaming agent, the emission of harmful substances is reduced, and the environmental protection property is enhanced; foaming conditions are accurately controlled, a pore structure is optimized, and VOC release is reduced; the flame retardant and the antibacterial agent are added, so that the safety and sanitation of the material are improved; the VOC emission is obviously lower than that of a traditional method, and the environmental protection standard is met. According to the invention, material performance and environmental protection requirements are effectively balanced, and green development of automotive interior materials is promoted.

Description

Technical Field

[0001] The invention relates to the field of new polymer materials, and in particular to an environmentally friendly PVC synthetic leather for automobile interior decoration with low VOC emission and a preparation process thereof. Background Art

[0002] The synthetic leather industry has undergone multiple generations of product upgrades from PVC artificial leather to PU synthetic leather, and then to eco-functional polyurethane synthetic leather.

[0003] In the production process of traditional PVC synthetic leather, plasticizer DOP and heavy metal-containing stabilizers are used. These substances will pollute the environment, and the harmful substances that may remain in the product will also affect human health and product environmental indicators. In order to reduce the risk of VOC in the car, it is very important to develop low-VOC emission automotive interior materials. This includes selecting low-VOC raw materials, improving production processes, and adopting environmentally friendly formulas and technologies. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an environmentally friendly PVC synthetic leather for automotive interior with low VOC emissions and a preparation process to solve one or more problems in the prior art.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] A preparation process of environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, comprising the following steps:

[0007] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 60% to 80% of the total fiber amount, and the PLA fiber accounts for 20% to 40% of the total fiber amount. Cut the mixed fiber to a preset length. The preset length of the mixed fiber is 3 to 7 mm.

[0008] In S1, flax fiber and PLA fiber are mixed by a preset mass percentage and cut to a uniform length. This step helps to ensure the structural uniformity of the synthetic leather substrate and the mechanical properties of the reinforced material.

[0009] S2: Surface treatment of cut hybrid fibers using a bio-based surface treatment agent.

[0010] In S2, the hybrid fibers are surface treated with a bio-based surface treatment agent, which improves the compatibility of the fibers with the PVC resin, thereby enhancing the overall performance and durability of the synthetic leather.

[0011] S3: Using a high-speed mixing method, PVC resin, bio-based stabilizer and mixed fiber are mixed according to a preset mass percentage for 10 to 20 minutes until the mixture is uniform, wherein the PVC resin accounts for 85% to 90% and the mixed fiber accounts for 10% to 15%. The mixture is heated to the melting temperature range of the PVC resin, 170°C to 190°C, and maintained for 3 to 7 minutes to obtain a molten mixture.

[0012] In S3, PVC resin, bio-based stabilizer and mixed fiber are mixed by high-speed mixing method and heated to melt, ensuring the uniform dispersion and processing fluidity of the materials, laying a good foundation for subsequent foaming and molding.

[0013] S4: Under a preset temperature and pressure, the molten mixture is mixed with a physical foaming agent according to a preset mass percentage for 2 to 4 minutes for physical foaming.

[0014] In S4, physical foaming is carried out under controlled temperature and pressure, using carbon dioxide or nitrogen as a blowing agent: lightweighting of synthetic leather and improvement of its cushioning properties are achieved.

[0015] S5: injecting the treated mixture into a preheated mold, curing and molding the mixture in the mold at a preset temperature and pressure, and removing the molded synthetic leather from the mold after cooling;

[0016] In S5, preheating the mold can prevent the synthetic leather from cooling too quickly and causing uneven internal structure.

[0017] S6: For synthetic leather, coating, embossing and drying are performed in sequence within a preset mechanical pressure and temperature range, and the coating is cured within a preset temperature and time range.

[0018] In S6, coating the synthetic leather improves the surface wear resistance and tensile strength of the material, and further limits the emission of VOC molecules through the surface coating.

[0019] In a preferred embodiment of the present invention, in S4, the preset temperature is 70°C to 80°C.

[0020] In the above technical solution, the preset length of the mixed fiber of S1 is 3 to 7 mm, which helps to obtain better mechanical properties and surface effects.

[0021] In a preferred embodiment of the present invention, in S4, the physical foaming agent is one or more of a carbon dioxide foaming agent and a nitrogen foaming agent.

[0022] In the above technical solution, the physical foaming agent of S4 is selected as carbon dioxide or nitrogen, which helps to reduce environmental pollution and improve the environmental performance of the product.

[0023] In a preferred embodiment of the present invention, in S4, the preset pressure is 3-5 bar, and the physical foaming agent accounts for 5%-8% of the total weight. In this pressure range, the foaming agent can produce a pore structure with moderate size and density, reduce the emission of VOC molecules and enhance the structural strength of the material.

[0024] In a preferred embodiment of the present invention, in S5, the preheating temperature of the mold is 45° C. to 55° C. The preset temperature of the curing molding process is 110° C. to 130° C., the preset pressure of the curing molding process is 4 to 6 bar, and the curing molding process time is 15 to 25 minutes.

[0025] In the above technical solution, the mold preheating and curing molding conditions of S5 are precisely controlled, which helps to improve production efficiency and product consistency.

[0026] In a preferred embodiment of the present invention, in S6, colorant is added during the embossing process, accounting for 3% to 6% of the total mass.

[0027] In the above technical solution, the colorant is added during the embossing stage. The mechanical pressure of embossing is relatively large and the working temperature is relatively high. The combination of the colorant and the synthetic leather is more compact and firm, thereby improving the adding effect.

[0028] In a preferred embodiment of the present invention, in S6, the preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180°C, and the preset temperature of the embossing stage is 80°C to 100°C; the preset temperature of the drying stage is 60°C to 100°C, and the drying time is 10min to 15min; the coating curing temperature is 110°C to 130°C, and the curing stage time is 3h to 5h.

[0029] In the above technical solution, the preset temperature of the coating stage is slightly lower than the melting temperature of the PVC resin, which can not only restore a certain fluidity of the synthetic leather to facilitate coating, but also ensure that the pore structure generated in the foaming step is not destroyed. The preset temperature of the embossing stage is lower than the coating stage to prevent the antibacterial agent added in the coating stage from becoming ineffective. The preset temperature of the drying stage is lower than the curing temperature of the coating because the function of this stage is to remove excess moisture or solvent in the coating. Too high a temperature will cause deformation of the coating material and affect the coating effect.

[0030] In a preferred embodiment of the present invention, the bio-based stabilizer is one or more of epoxy linseed oil or fatty acid salt, and the bio-based surface treatment agent is one or more of alkyl glycoside or alkanolamide. Flame retardant and antibacterial agent need to be added in the preparation process, the flame retardant is one or more of aluminum hydroxide, polyphosphoamine, zinc borate, and the antibacterial agent is one or more of silver ion antibacterial agent, nano inorganic antibacterial agent, organosilicon quaternary ammonium salt antibacterial agent or chitosan quaternary ammonium salt antibacterial agent.

[0031] In the above technical solution, the selected bio-based stabilizers and surface treatment agents are environmentally friendly materials, which further enhances the environmental protection characteristics of synthetic leather. By adding flame retardants and antibacterial agents in specific steps, synthetic leather is given additional safety and hygiene, which broadens the application range of the product.

[0032] In a preferred embodiment of the present invention, in the preparation process, the flame retardant is directly added and mixed in any step S3 or S4, accounting for 5% to 8% of the total mass. The antibacterial agent is added in the coating stage S6, accounting for 0.5% to 3% of the total mass.

[0033] To achieve the above-mentioned purpose, the second technical solution adopted by the present invention is a low-VOC emission environmentally friendly PVC synthetic leather for automobile interior, which is prepared based on a preparation process for a low-VOC emission environmentally friendly PVC synthetic leather for automobile interior.

[0034] Compared with the prior art, the beneficial technical effects of the present invention are as follows

[0035] (i) By selecting environmentally friendly bio-based materials and biodegradable fibers, such as flax fiber and PLA fiber, not only the mechanical properties of synthetic leather are improved, but also its biodegradability is increased, which helps to reduce the environmental footprint. Secondly, the use of bio-based surface treatment agents and stabilizers enhances the compatibility of fibers with PVC resins, while reducing the addition of harmful substances during processing.

[0036] (ii) In the physical foaming process, the pore structure of synthetic leather is optimized by precisely controlling the addition ratio of the foaming agent and the temperature and pressure of the foaming process, which not only helps to improve the lightweight and cushioning performance of synthetic leather, but also reduces the escape of VOC molecules. During the curing process, precise control of temperature and pressure ensures the shape stability and dimensional accuracy of synthetic leather, while also affecting the release of VOCs.

[0037] (III) The coating treatment stage not only improves the appearance and feel of the product, but also enhances its functionality and safety by adding colorants and antimicrobial agents. Throughout the preparation process, the conditions of each step, such as melting, foaming, curing and cooling, are precisely controlled to ensure a balance between the physical properties and environmental performance of synthetic leather. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a schematic diagram of a process for preparing an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention more clear, the following is a further detailed description of a low VOC emission automotive interior environmentally friendly PVC synthetic leather and preparation process proposed by the present invention in combination with the accompanying drawings and embodiments. It should be noted that the structure, proportion, size, etc. shown in the drawings attached to this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0040] The preparation process of the environmentally friendly PVC synthetic leather for automobile interior with low VOC emission of the present invention comprises the following steps:

[0041] S1: Mixing flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 60% to 80% of the total fiber amount and the PLA fiber accounts for 20% to 40% of the total fiber amount. Cutting the mixed fiber to a preset length.

[0042] In S1, flax fiber is a natural plant fiber with excellent breathability and comfort. The use of flax fiber in synthetic leather can provide a texture and appearance that is closer to natural leather. PLA fiber is a bio-based degradable material derived from renewable resources such as corn starch or sugarcane. Its use helps to improve the environmental performance of synthetic leather and reduce the impact of the product on the environment after its life cycle. Flax fiber and PLA fiber are both biodegradable materials, and their combined use can reduce pollution to the environment. Flax fiber and PLA fiber can enhance the mechanical properties of synthetic leather, such as tensile strength, tear strength and abrasion resistance, thereby improving the durability and service life of the product.

[0043] The preset length of the mixed fiber is 3 to 7 mm. By mixing the flax fiber and the PLA fiber in a preset mass percentage and cutting them to a uniform length, this step helps to ensure the structural uniformity of the synthetic leather substrate and the mechanical properties of the enhanced material.

[0044] S2: Surface treatment of cut hybrid fibers using a bio-based surface treatment agent.

[0045] In S2, the bio-based surface treatment agent is one or more of alkyl glycoside or alkanolamide, and the amount of bio-based surface treatment agent added is 5% to 8% of the total mass of the mixed fiber. After the bio-based surface treatment, the compatibility of the mixed fiber and PVC resin is improved. Alkyl glycoside and alkanolamide are both non-ionic surfactants with excellent mildness, no irritation to the skin, non-toxic, and good compatibility with the skin. Alkyl glycoside and alkanolamide both have low surface tension, which can improve the wetting and penetration properties of the product, and help improve the processing properties of the material and the performance of the final product. Alkyl glycoside has a broad spectrum of antibacterial activity and can be used as a natural preservative in synthetic leather products.

[0046] S3: Using a high-speed mixing method, PVC resin, bio-based stabilizer and mixed fiber are mixed according to a preset mass percentage for 10 to 20 minutes until the mixture is uniform, wherein the PVC resin accounts for 85% to 90% and the mixed fiber accounts for 10% to 15%. The mixture is heated to the melting temperature range of the PVC resin, 170°C to 190°C, and maintained for 3 to 7 minutes to obtain a molten mixture.

[0047] In S3, the bio-based stabilizer is one or more of epoxy linseed oil or fatty acid salts, and the added mass of the bio-based stabilizer is 3% to 5% of the mass of the PVC resin. The bio-based stabilizer can withstand high temperatures during the production of PVC synthetic leather, prevent thermal degradation of the material during processing, improve the flexibility and aging resistance of PVC synthetic leather, and extend the service life of the product. It helps to reduce the emission of volatile organic compounds in the production process of synthetic leather, which meets the current environmental protection requirements.

[0048] The interaction between the molecular structure of flax fiber and PLA fiber and PVC resin enhances the overall structural stability of the material, which helps to form a more uniform pore structure during the foaming process. This is because: flax fiber is mainly composed of cellulose molecules, and its molecular structure contains a large number of hydroxyl groups (-OH) and other functional groups. These functional groups can form hydrogen bonds or van der Waals forces with chlorine atoms (Cl) in PVC resin or other additive molecules, thereby enhancing the interaction between the two. PLA fiber is a fiber form of polylactic acid, and its molecular chain contains ester groups (-COO-), which can also form relatively stable interactions with chlorine atoms in PVC resin or other additive molecules.

[0049] During the mixing process, the proportion of flax fiber and PLA fiber will affect the reinforcing effect of the mixed fiber on PVC resin.

[0050] S4: Under a preset temperature and pressure, the molten mixture is mixed with a physical foaming agent according to a preset mass percentage for 2 to 4 minutes for physical foaming, wherein the preset temperature is 70° C. to 80° C., the preset pressure is 3 to 5 bar, and the physical foaming agent accounts for 5% to 8% of the total weight.

[0051] In S4, the physical foaming agent is one or more of a carbon dioxide foaming agent and a nitrogen foaming agent. Physical foaming is carried out under controlled temperature and pressure, and carbon dioxide or nitrogen is used as a foaming agent to achieve lightweight synthetic leather and improve its cushioning properties. Carbon dioxide and nitrogen, as physical foaming agents, do not produce toxic gases or pollutants, and do not cause any harm to the environment and human body. After foaming with a physical foaming agent, no residue will be left in the material, and the effect on the performance of the foamed plastic is not significant, thereby ensuring the purity and performance of the synthetic leather. Both carbon dioxide and nitrogen have flame retardant properties, which can improve the flame retardant properties of synthetic leather and enhance the safety of the material.

[0052] During the foaming process, the use of carbon dioxide foaming agent, foaming temperature, pressure and time and other parameters are the key factors to achieve uniform distribution of foam and stable pore structure. By adjusting these parameters, it is possible to ensure that the foaming agent is evenly distributed in the PVC resin and produces uniform bubbles, thereby obtaining an ideal pore structure. A pore structure with too high a density will lead to a decrease in the flexibility and elasticity of the PVC synthetic leather, and a pore structure with too large a density will reduce the difficulty of VOC molecules to overflow, thereby increasing VOC emissions.

[0053] The interaction between the molecular structure of flax fiber and PLA fiber and PVC resin enhances the overall structural stability of the material, which helps to form a more uniform pore structure during the foaming process. This is because: flax fiber is mainly composed of cellulose molecules, and its molecular structure contains a large number of hydroxyl groups (-OH) and other functional groups. These functional groups can form hydrogen bonds or van der Waals forces with chlorine atoms (Cl) in PVC resin or molecules of other additives, thereby enhancing the interaction between the two. PLA fiber is a fiber form of polylactic acid, and its molecular chain contains ester groups (-COO-). These ester groups can also form relatively stable interactions with chlorine atoms or molecules of other additives in PVC resin. The synergistic effect of flax fiber and PLA fiber not only improves the mechanical properties, wear resistance and corrosion resistance of PVC synthetic leather, but also makes the synthetic leather more stable during use.

[0054] The addition of flax fiber and PLA fiber provides more nucleation points for the foaming process. Under the action of the foaming agent, bubbles are more likely to form around these nucleation points, and the growth process of the bubbles is more uniform, which helps to form a uniform pore structure.

[0055] The proportion of flax fiber and PLA fiber in Scheme S1 will affect the physical properties of the final synthetic leather.

[0056] In the preparation process, a flame retardant needs to be added. The flame retardant is one or more of aluminum hydroxide, polyphosphate amine, and zinc borate. The flame retardant is directly added and mixed in any step S3 or S4.

[0057] S5: injecting the treated mixture into a preheated mold, curing and molding the mixture in the mold at a preset temperature and pressure, and taking the molded synthetic leather out of the mold after cooling.

[0058] In S5, the preheating temperature of the mold is 45°C to 55°C. The preset temperature of the curing process is 110°C to 130°C, the preset pressure of the curing process is 4 to 6 bar, and the curing time is 15 to 25 minutes. The mixture is injected into the preheated mold and cured. By precisely controlling the curing conditions, the shape stability and dimensional accuracy of the synthetic leather product are ensured.

[0059] In S5, the cooling method is one or more of air cooling or natural cooling. The synthetic leather after molding is cooled to room temperature by air cooling or natural cooling. The cooling rate of the synthetic leather is effectively controlled by air cooling or natural cooling, which prevents thermal damage and internal stress of the material, and also helps to reduce energy consumption and improve production efficiency.

[0060] S6: For synthetic leather, coating, embossing and drying are performed in sequence within a preset mechanical pressure and temperature range, and the coating is cured within a preset temperature and time range.

[0061] In S6, the preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3 h to 5 h. Coating synthetic leather improves the surface wear resistance and tensile resistance of the material, and further limits the dispersion of VOC molecules through the surface coating.

[0062] The preset temperature of the coating stage is slightly lower than the melting temperature of PVC resin, which can restore a certain fluidity of synthetic leather for easy coating and ensure that the pore structure produced in the foaming step is not destroyed. The preset temperature of the embossing stage is lower than that of the coating stage to prevent the antibacterial agent added in the coating stage from becoming ineffective. The preset temperature of the drying stage is lower than the curing temperature of the coating because this stage is used to remove excess water or solvent in the coating. Too high a temperature will cause deformation of the coating material and affect the coating effect.

[0063] It is also necessary to add an antibacterial agent in the preparation process, and the antibacterial agent is one or more of a silver ion antibacterial agent, a nano inorganic antibacterial agent, a silicone quaternary ammonium salt antibacterial agent or a chitosan quaternary ammonium salt antibacterial agent. The antibacterial agent is added in a post-processing manner in S6. The antibacterial agent can withstand changes in temperature and pressure in the preparation process without losing its effect and remains effective for a long time. The antibacterial agent has a broad-spectrum antibacterial effect and can effectively fight against a variety of bacteria and viruses, including Staphylococcus aureus, Escherichia coli, etc., and is harmless to the human body and is not easy to cause bacterial resistance.

[0064] To achieve the above-mentioned purpose, the second technical solution adopted by the present invention is a low-VOC emission environmentally friendly PVC synthetic leather for automobile interior, based on a preparation process of a low-VOC emission environmentally friendly PVC synthetic leather for automobile interior.

[0065] In order to ensure the completeness and rationality of this plan, the optimal ratio of flax fiber and PLA fiber needs to be verified before its specific implementation.

[0066] The synthetic leathers in samples one to five were cut into samples of different sizes and tested using the strip method according to the national standard GB / T38612-2020 (Test methods for artificial leather and synthetic leather - Determination of tensile load and elongation at break). The test results are shown in Table 1.

[0067] Table 1 The percentage of flax fiber and PLA fiber and the physical strength data of synthetic leather

[0068]

[0069] It can be seen from Table 1 that from sample 1 to sample 3, the proportion of flax fiber gradually increases, and the tensile strength and elongation at break also increase accordingly. At this time, the proportion in sample 3 is the best.

[0070] From sample three to sample five, the proportion of flax fiber gradually increases, while the tensile strength and elongation at break decrease. At this time, the proportion in sample three is the best.

[0071] Therefore, when flax fiber accounts for 70% and PLA fiber accounts for 30%, this solution has the best ratio.

[0072] Embodiment 1

[0073] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0074] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0075] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0076] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0077] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 3 bar, and the carbon dioxide foaming agent accounts for 5% of the total weight.

[0078] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0079] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0080] Embodiment 2

[0081] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0082] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0083] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0084] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0085] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 4 bar, and the carbon dioxide foaming agent accounts for 5% of the total weight.

[0086] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0087] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0088] Embodiment 3

[0089] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0090] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0091] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0092] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0093] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 5 bar, and the carbon dioxide foaming agent accounts for 5% of the total weight.

[0094] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0095] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0096] Embodiment 4

[0097] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0098] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0099] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0100] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0101] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 4 bar, and the carbon dioxide foaming agent accounts for 6% of the total weight.

[0102] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0103] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0104] Embodiment 5

[0105] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0106] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0107] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0108] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0109] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 4 bar, and the carbon dioxide foaming agent accounts for 7% of the total weight.

[0110] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0111] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0112] Embodiment 6

[0113] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0114] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0115] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0116] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0117] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 4 bar, and the carbon dioxide foaming agent accounts for 8% of the total weight.

[0118] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0119] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0120] Comparative Example 1

[0121] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0122] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0123] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0124] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0125] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 4 bar, and the carbon dioxide foaming agent accounts for 9% of the total weight.

[0126] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0127] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0128] Comparative Example 2

[0129] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0130] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0131] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0132] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0133] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 5 bar, and the carbon dioxide foaming agent accounts for 9% of the total weight.

[0134] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0135] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0136] Comparative Example 3

[0137] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0138] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0139] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0140] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0141] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 7 bar, and the carbon dioxide foaming agent accounts for 5% of the total weight.

[0142] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0143] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0144] Comparative Example 4

[0145] This embodiment provides an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, and the preparation method is as follows:

[0146] S1: Mix flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 70% of the total fiber amount and the PLA fiber accounts for 30% of the total fiber amount. Cut the mixed fiber into a length of 5 mm.

[0147] S2: The cut mixed fibers are surface treated with a bio-based surface treatment agent. The bio-based surface treatment agent is an alkyl polyglycoside.

[0148] S3: Use a high-speed mixing method to mix PVC resin, bio-based stabilizer, flame retardant and mixed fiber according to the preset mass percentage for 15 minutes until the mixture is uniform, wherein the PVC resin accounts for 90%, the mixed fiber accounts for 10%, the bio-based stabilizer is 4% of the PVC resin, and the flame retardant is 6% of the total mass. Heat the mixture to 180°C, the melting temperature range of the PVC resin, and maintain it for 5 minutes to obtain a molten mixture. The bio-based stabilizer is epoxy linseed oil and the flame retardant is chlorine hydroxide.

[0149] S4: Under a preset temperature and pressure, the molten mixture is mixed with a carbon dioxide foaming agent according to a preset mass percentage for 3 minutes for physical foaming, wherein the preset temperature is 75° C., the preset pressure is 7 bar, and the carbon dioxide foaming agent accounts for 6% of the total weight.

[0150] S5: inject the treated mixture into a mold preheated to 50° C., and solidify the mixture in the mold at a temperature of 120° C. and a pressure of 5 bar. The solidification molding process takes 20 minutes. After cooling, the molded synthetic leather is taken out of the mold.

[0151] S6: For synthetic leather, coating, embossing and drying are carried out in sequence within the preset mechanical pressure and temperature range, and the coating is cured within the preset temperature and time range. The preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180 ° C, and the preset temperature of the embossing stage is 80 ° C to 100 ° C; the preset temperature of the drying stage is 60 ° C to 100 ° C, and the drying time is 10 min to 15 min; the coating curing temperature is 110 ° C to 130 ° C, and the curing stage time is 3h to 5h. 4% of colorant and 2% of antibacterial agent are mixed in the coating material, and the antibacterial agent is a silver ion antibacterial agent.

[0152] The synthetic leathers in Examples 1 to 6 and Comparative Examples 1 to 4 were cut into samples of different sizes, and VOC emissions were tested on the samples using the gas phase separation qualitative method according to the national standard GB 21902-2008 "Synthetic Leather and Artificial Leather Industry Pollutant Emission Standard". The test results are shown in Table 2.

[0153] Table 2 VOC emission data of samples in Examples 1 to 6 and Comparative Examples 1 to 4 As can be seen from Table 2, the VOC emissions in Examples 1 to 6 are all lower than those in Comparative Examples 1 to 4. The preparation process of the environmentally friendly PVC synthetic leather for automotive interior with low VOC emissions in the present invention can effectively ensure that the PVC emissions of the PVC synthetic leather meet national standards.

[0154] In Examples 1 to 3, the foaming pressure gradually increased, and the VOC emission of the samples did not change significantly but gradually decreased. This is because the increase in foaming pressure will cause the average size of the pore structure in the sample to slightly decrease, limiting the escape of some VOC macromolecules from the pore structure, so the VOC emission will slightly decrease.

[0155] In Examples 4 to 6, the proportion of the foaming agent in the total mass gradually increased, and the VOC emission of the samples gradually increased. This is because the increase in the proportion of the foaming agent leads to an increase in the pore structure in the PVC synthetic leather, and the number of VOC small molecules escaping from it also increases accordingly.

[0156] Therefore, the best embodiment is embodiment three.

[0157] In Comparative Examples 1 and 2, compared with Examples 1 to 6, the pressure during the sample production process is within the preset range, but the excessive addition of the foaming agent results in an excessive number of pore structures in the sample, and the number of VOC small molecules escaping also increases accordingly.

[0158] In Comparative Examples 3 and 4, compared with Examples 1 to 6, the proportion of the foaming agent in the sample production process is within the preset range, but the foaming pressure increases, and the resulting pore structure is over-compressed, causing structural damage, which in turn causes a large amount of VOC molecules to escape.

[0159] Therefore, the proportion of the added foaming agent and the size of the foaming pressure are of great significance to the preparation process of the present invention.

[0160] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A process for preparing environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, characterized in that: The following steps are included: S1: mixing flax fiber and PLA fiber according to a preset mass percentage to obtain mixed fiber, wherein the flax fiber accounts for 60% to 80% of the total fiber amount, and the PLA fiber accounts for 20% to 40% of the total fiber amount; cutting the mixed fiber to a preset length; wherein the preset length of the mixed fiber is 3 to 7 mm; S2: surface treatment of cut hybrid fibers using bio-based surface treatment agents; S3: Mixing the PVC resin, the bio-based stabilizer and the mixed fiber according to a preset mass percentage for 10 to 20 minutes by a high-speed mixing method until the mixture is uniform, wherein the PVC resin accounts for 85% to 90%, the mixed fiber accounts for 10% to 15%, and the bio-based stabilizer accounts for 3% to 5% of the PVC resin; heating the mixture to the melting temperature range of the PVC resin, 170° C. to 190° C., and maintaining it for 3 to 7 minutes to obtain a molten mixture; S4: under a preset temperature and pressure, mixing the molten mixture with a physical foaming agent according to a preset mass percentage for 2 to 4 minutes for physical foaming; S5: injecting the treated mixture into a preheated mold, curing and molding the mixture in the mold at a preset temperature and pressure, and removing the molded synthetic leather from the mold after cooling; S6: For synthetic leather, coating, embossing and drying are performed in sequence within a preset mechanical pressure and temperature range, and the coating is cured within a preset temperature and time range.

2. The process for preparing the environmentally friendly PVC synthetic leather for automobile interior with low VOC emission as claimed in claim 1, characterized in that: In S4, the preset temperature is 70°C to 80°C.

3. The process for preparing the environmentally friendly PVC synthetic leather for automobile interior with low VOC emission as claimed in claim 1, characterized in that: In S4, the physical foaming agent is one or more of a carbon dioxide foaming agent and a nitrogen foaming agent.

4. The process for preparing the environmentally friendly PVC synthetic leather for automobile interior with low VOC emission as claimed in claim 1, characterized in that: In S4, the preset pressure is 3-5 bar, and the physical foaming agent accounts for 5%-8% of the total weight.

5. The process for preparing the environmentally friendly PVC synthetic leather for automobile interior with low VOC emission as claimed in claim 1, characterized in that: In S5, the preheating temperature of the mold is 45°C to 55°C; the preset temperature of the curing molding process is 110°C to 130°C, the preset pressure of the curing molding process is 4 to 6 bar, and the time of the curing molding process is 15 to 25 minutes.

6. The process for preparing the environmentally friendly PVC synthetic leather for automobile interior with low VOC emission as claimed in claim 1, characterized in that: In S6, colorant is added during the embossing process, accounting for 3% to 6% of the total mass.

7. The process for preparing the environmentally friendly PVC synthetic leather for automobile interior with low VOC emission as claimed in claim 1, characterized in that: In S6, the preset mechanical pressure for coating and embossing is 10 bar to 15 bar, and the preset temperature of the coating stage is 170 to 180°C, and the preset temperature of the embossing stage is 80°C to 100°C; the preset temperature of the drying stage is 60°C to 100°C, and the drying time is 10min to 15min; the coating curing temperature is 110°C to 130°C, and the curing stage time is 3h to 5h.

8. The process for preparing the environmentally friendly PVC synthetic leather for automobile interior with low VOC emission as claimed in claim 1, characterized in that: The bio-based stabilizer is one or more of epoxy linseed oil or fatty acid salts, and the bio-based surface treatment agent is one or more of alkyl glycosides or alkanolamides; flame retardants and antibacterial agents need to be added in the preparation process, the flame retardant is one or more of aluminum hydroxide, polyphosphate amine, and zinc borate, and the antibacterial agent is one or more of silver ion antibacterial agent, nano inorganic antibacterial agent, silicone quaternary ammonium salt antibacterial agent or chitosan quaternary ammonium salt antibacterial agent.

9. The process for preparing the environmentally friendly PVC synthetic leather for automobile interior with low VOC emission as claimed in claim 8, characterized in that: In the preparation process, the flame retardant is directly added and mixed in any step S3 or S4, accounting for 5% to 8% of the total mass; the antibacterial agent is added in the S6 coating stage, accounting for 0.5% to 3% of the total mass.

10. An environmentally friendly PVC synthetic leather for automobile interior with low VOC emission, prepared based on the preparation process of an environmentally friendly PVC synthetic leather for automobile interior with low VOC emission according to any one of claims 1 to 9.

Images