Spraying-free antibacterial material for automobile and preparation method of spraying-free antibacterial material

Abstract

The invention discloses a spraying-free antibacterial material for automobiles and a preparation method of the spraying-free antibacterial material, and belongs to the field of high polymer materials. Step 2, preparing doped polyaniline; step 3, preparing functional components; and step 4, preparing the spraying-free antibacterial material to obtain the spraying-free antibacterial material for the automobile. Considering the dispersibility of each component in the preparation process, the scheme adopts different dispersion modes to prepare powdery modified titanium dioxide, doped polyaniline, functional components and the like, and the finally prepared product not only has a good antibacterial effect, but also has the characteristics of high strength, wear resistance, dirt resistance and the like.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and in particular to a spray-free antibacterial material for automobiles and a preparation method thereof. Background Art

[0002] As car ownership increases, the plastic feel inside cars is becoming increasingly pronounced. This plasticity isn't just felt visually and tactilely, it's also felt odorously. This is because interior panels often use a spray-coating process, and the volatile solvents don't evaporate easily within the confined space of the car, creating a "plastic smell." Furthermore, plastic surfaces easily absorb bacteria, causing odors and potentially respiratory infections. Spray-free materials are polymer-based composites that address these shortcomings. By filling them with colorants, they can be directly injection molded for use in automotive interiors.

[0003] CN110791083B discloses a highly antibacterial and weather-resistant spray-free filled polyamide composite material and its preparation method. Specifically, the composite material comprises the following raw materials by weight: 40-80 parts polyamide resin, 3-10 parts compatibilizer, 1-8 parts dispersant, 8-25 parts functionalized masterbatch, and 1-5 parts weathering additive. The functionalized masterbatch is composed of the following components by weight: 3-10 parts acrylate copolymer, 3-8 parts nano-aerogel, 1-6 parts silver ion antibacterial agent, and 1-5 parts metallic colorant. This invention can achieve a good appearance.

[0004] CN104530565B relates to a spray-free polypropylene composite material with antibacterial function, as well as its preparation method and application. The spray-free polypropylene composite material comprises the following components: 66.5-96% homopolypropylene, 0-30% transparent filler, 2-10% antibacterial agent masterbatch, 0.1-1.5% glass-based pearlescent pigment, 0.2-0.3% antioxidant, and 0.2-0.3% additive A. The invention obtains a spray-free polypropylene composite material with antibacterial function by mixing the aforementioned materials, then adding them to the main feed hopper of a parallel twin-screw extruder, melting, extruding, cooling, drying, and pelletizing. The above-mentioned spray-free material technologies can all achieve good antibacterial effects, but do not mention wear resistance. Summary of the Invention

[0005] To solve the above problems, the present invention provides a spray-free antibacterial material for automobiles and a preparation method thereof, which not only has good antibacterial effect, but also has the characteristics of high strength and wear resistance.

[0006] To achieve the above object, the technical solution of the present invention is: This proposal proposes a method for preparing a spray-free antibacterial material for automobiles, comprising the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, mixing 1 part of nano-titanium dioxide, 0.3-0.5 parts of aniline monomer, 0.01-0.05 parts of silane coupling agent and 0.5 parts to 1 part of organic solvent, ball milling for 3-5 hours, unloading, evaporating the solvent under vacuum conditions to obtain adhesion modified nano-titanium dioxide, and dispersing to obtain modified nano-titanium dioxide; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 0.8 mol / L-1.2 mol / L sulfuric acid solution, so that the mass concentration of aniline monomer in the solution is 0.05 g / L-0.15 g / L after addition, stirring at a speed of 5-10 r / s for 30 min-60 min, adding modified nano-titanium dioxide with a mass ratio of 0.1%-0.3% of the mass of aniline monomer, continuing stirring at a speed of 5-10 r / s for 60 min-120 min, and then dropwise adding 0.5 volume-1.5 volume of a strong acid solution containing ammonium persulfate and copper sulfate. After the dropwise addition is completed, reacting under low temperature, ultrasonic and stirring conditions for 4 h-8 h, filtering, washing, drying, and sieving to obtain doped polyaniline; The strong acid solution is a 0.8 mol / L-1.2 mol / L sulfuric acid solution or a 20%-35% hydrochloric acid solution; the concentration of ammonium persulfate in the strong acid solution is 200 g / L-250 g / L, and the concentration of copper sulfate is 10-20 g / L; Step 3, preparing a functional component: adding 0.5-1 part of a dispersant, 0.5-1 part of a weathering agent, and 5-10 parts of a filler to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 4, preparing a spray-free antibacterial material: heating 100 parts of polyamide resin to 220-300°C by weight, adding 30-70 parts of functional components under stirring, continuing stirring for 2-4 hours, then extruding, drying, and granulating to obtain a spray-free antibacterial material for automobiles.

[0007] The spray-free antibacterial material for automobiles prepared by this solution has the following characteristics: 1. Add modified nano-titanium dioxide. Modified nano-titanium dioxide can improve the weather resistance of spray-free antibacterial materials. The dispersibility of nano-titanium dioxide has always been a pain point in its application in the field of polymer materials. This solution uses ball milling and vacuum evaporation of organic solvents to attach silane coupling agents and aniline monomers to the surface of nano-titanium dioxide, and further disperse to obtain modified nano-titanium dioxide. The aniline monomer attached to the modified titanium dioxide can participate in the polymerization reaction in step 2. As the reaction proceeds, the modified titanium dioxide enters the generated polyaniline, and eventually enters the dispersed polyaniline particles, that is, the doped polyaniline.

[0008] 2. The doped polyaniline is made into powder in consideration of dispersibility. This is mainly based on the following two considerations: a. The doped polyaniline contains polyaniline. Conventional high-speed stirring and mixing may cause the surface of the particles to melt due to heating of the stirrer and other reasons, resulting in poor dispersion. In step 3, in order to enhance the mixing effect, this solution uses an airflow mixer to mix the materials. Simply put, the components are blown up by gas, and the components are mixed with each other due to the disturbance of the airflow, and finally the functional components of this solution are obtained. If the doped polyaniline is a granular material, the uniformity of this solution cannot be obtained; b. The functional component contains polyaniline. The powder is easier to add evenly due to its large specific surface area and low melting point. Therefore, adding it under continuous stirring conditions in step 4 can mix the materials to the greatest extent, and at the same time melt the doped polyaniline and fully mix it with the molten polyamide, thereby improving the strength and wear resistance of the spray-free antibacterial material.

[0009] 3. Polyaniline has intrinsic antibacterial properties. The modified polyaniline prepared in step 2 of this protocol has intrinsic antibacterial properties. This is because polyaniline itself can be used as a preservative and bactericide. Furthermore, the design of doping ions, such as copper ions, can enhance its antibacterial properties.

[0010] 4. Polyaniline is conductive. The design of doped ions can enhance the conductivity of polyaniline, making the spray-free antibacterial material antistatic. Eliminating surface static electricity in automotive interiors can reduce dust adsorption, making the interior more resistant to dirt. Furthermore, polyaniline has an electrochromic effect. Applying different voltages within the mold during molding can produce different colors of molding material. Therefore, it can be used without the addition of metallic toner. Furthermore, because the copper ion-doped portion moves toward the lower potential, the molding surface of the material in that direction has better antibacterial properties.

[0011] Preferably, the dispersant is one or more of calcium stearate, zinc stearate, and copolyamide wax.

[0012] Preferably, the weathering agent is carbon black. Nano titanium dioxide itself is a weathering agent.

[0013] Preferably, the filler is one or more of zinc oxide powder, magnesium oxide powder, aluminum powder, copper-gold powder, and silicon dioxide powder. The filler is used to enhance wear resistance and strength, and metallic color powder is also added to adjust color and gloss.

[0014] Preferably, in step 1, the organic solvent is ethanol; and the dispersion method comprises placing the adhered modified nano-titanium dioxide in a blender and stirring at a speed of 10-30 rpm for 20-60 seconds. If the speed is too high, the silane coupling agent and aniline monomer attached to the surface of the modified nano-titanium dioxide may easily fall off, or the blender may heat up and cause adhesion.

[0015] Preferably, in step 2, the low temperature, ultrasound, and stirring conditions are: -5°C to -10°C, 10 MHz to 20 MHz, and 1000 rpm to 2000 rpm; the drying temperature is 60°C to 90°C; and the doped polyaniline is sieved through a 20-50 mesh slap sieve. The low temperature takes into account the polymerization reaction temperature of polyaniline. The doped polyaniline obtained in step 2 is a powder. To obtain the finest possible powder, this solution uses ultrasound and high-speed stirring, and the particle size is controlled by slap sieves.

[0016] Preferably, in step 2, the rate of adding 0.5 to 1.5 volumes of the strong acid solution containing ammonium persulfate and copper sulfate is 0.0005 to 0.0008 volumes per second. For a sufficient reaction, the rate of adding the strong acid solution should not be too fast, which may cause uneven dispersion and uneven reaction.

[0017] Preferably, in step 4, the stirring rate is 5 r / s-10 r / s, and the drying temperature is 60°C-90°C.

[0018] This solution also proposes a spray-free antibacterial material for automobiles prepared by the above-mentioned method for preparing the spray-free antibacterial material for automobiles.

[0019] Compared with the prior art, the present invention has the following advantages: 1. The preparation principle is simple and can be adapted to large-scale production.

[0020] 2. This approach prepared modified titanium dioxide compatible with polyaniline-doped titanium dioxide to improve the product's weather resistance and enhance its wear resistance. Taking into account the dispersibility of each component during the preparation process, this approach employed different dispersion methods to prepare powdered modified titanium dioxide, polyaniline-doped titanium dioxide, and functional components. The resulting product not only exhibited excellent antibacterial properties but also exhibited high strength, wear resistance, and stain resistance. DETAILED DESCRIPTION

[0021] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0022] Example 1 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.4 parts of aniline monomer, 0.03 parts of silane coupling agent and 0.8 parts of ethanol were mixed and ball-milled for 4 hours, the mixture was unloaded, and the solvent was evaporated under vacuum conditions to obtain adhesion-modified nano-titanium dioxide, and the adhesion-modified nano-titanium dioxide was placed in a blender and stirred at a speed of 20 r / s for 40 seconds to obtain modified nano-titanium dioxide after dispersion; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 1 mol / L sulfuric acid solution, the mass concentration of aniline monomer in the solution after addition is 0.08 g / L, stirring at a speed of 8 r / s for 40 minutes, adding modified nano-titanium dioxide with a mass content of 0.2% of the aniline monomer, continuing stirring at a speed of 8 r / s for 90 minutes, and then dropping 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate and 15 g / L copper sulfate at a dropping rate of 0.0005 volume / s. After the dropwise addition is completed, reacting at a low temperature of -8°C, 15 MHz ultrasound and 1200 r / min stirring conditions for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 50-mesh sieve to obtain doped polyaniline; Step 3, preparing a functional component: adding 0.5 parts of calcium stearate, 0.5 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of magnesium oxide powder, and 2 parts of aluminum powder to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 4, preparing a spray-free antibacterial material: by weight, heat 100 parts of polyamide resin to 240°C, add 60 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain a spray-free antibacterial material for automobiles.

[0023] Example 2 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.5 parts of aniline monomer, 0.05 parts of silane coupling agent and 1 part of ethanol were mixed and ball-milled for 5 hours, unloaded, and the solvent was evaporated under vacuum conditions to obtain adhesion-modified nano-titanium dioxide. The adhesion-modified nano-titanium dioxide was placed in a blender and stirred at a speed of 30 r / s for 60 seconds to obtain modified nano-titanium dioxide after dispersion; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 1.2 mol / L sulfuric acid solution, the mass concentration of aniline monomer in the solution after addition is 0.12 g / L, stirring at a speed of 10 r / s for 60 minutes, adding modified nano-titanium dioxide with a mass content of 0.2% of the aniline monomer, continuing stirring at a speed of 10 r / s for 90 minutes, and then dropping 1 volume of 1 mol / L sulfuric acid solution containing 220 g / L ammonium persulfate and 20 g / L copper sulfate at a dropping rate of 0.0006 volume / s. After the dropwise addition is completed, reacting at a low temperature of -5°C, 15 MHz ultrasound and 1500 r / min stirring conditions for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 20-mesh sieve to obtain doped polyaniline; Step 3, preparing the functional component: by weight, adding 0.8 parts of calcium stearate, 0.8 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of copper and gold powder, and 2 parts of silicon dioxide powder to 100 parts of doped polyaniline, and mixing them evenly with an air flow mixer to obtain the functional component; Step 4, prepare spray-free antibacterial material: heat 100 parts of polyamide resin to 260°C by weight, add 60 parts of functional components under stirring conditions of 10r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain spray-free antibacterial material.

[0024] Example 3 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.3 parts of aniline monomer, 0.01 parts of silane coupling agent and 0.5 parts of ethanol were mixed and ball-milled for 5 hours, unloaded, and the solvent was evaporated under vacuum conditions to obtain adhesion-modified nano-titanium dioxide. The adhesion-modified nano-titanium dioxide was placed in a blender and stirred at a speed of 15 rpm for 20 seconds to obtain modified nano-titanium dioxide after dispersion; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 0.8 mol / L sulfuric acid solution, the mass concentration of aniline monomer in the solution after addition is 0.05 g / L, stirring at a speed of 5 r / s for 20 minutes, adding modified nano-titanium dioxide with a mass content of 0.3% of the aniline monomer, continuing stirring at a speed of 10 r / s for 100 minutes, and then dropping 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate and 15 g / L copper sulfate at a dropping rate of 0.0005 volume / s. After the dropwise addition is completed, reacting at a low temperature of -5°C, 15 MHz ultrasound and 1500 r / min stirring conditions for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 50-mesh sieve to obtain doped polyaniline; Step 3, preparing the functional component: by weight, adding 0.8 parts of zinc stearate, 0.8 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of copper-gold powder, and 2 parts of silicon dioxide powder to 100 parts of doped polyaniline, and mixing them evenly with an air flow mixer to obtain the functional component; Step 4, prepare spray-free antibacterial material: heat 100 parts of polyamide resin to 280°C by weight, add 40 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain spray-free antibacterial material.

[0025] Comparative Example 1 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing doped polyaniline: adding aniline monomer to 1 volume of 1 mol / L sulfuric acid solution, after the addition, the mass concentration of aniline monomer in the solution is 0.08 g / L, stirring at a speed of 8 r / s for 40 minutes, and then continuing to stir at a speed of 8 r / s for 90 minutes, and then adding 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate and 15 g / L copper sulfate dropwise at a dropping rate of 0.0005 volume / s. After the dropwise addition is completed, reacting at a low temperature of -8°C, 15 MHz ultrasound and 1200 r / min stirring conditions for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 50-mesh sieve to obtain doped polyaniline; Step 2, preparing a functional component: adding 0.5 parts of calcium stearate, 0.5 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of magnesium oxide powder, and 2 parts of aluminum powder to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 3, preparing a spray-free antibacterial material: by weight, heat 100 parts of polyamide resin to 240°C, add 60 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain a spray-free antibacterial material for automobiles.

[0026] Comparative Example 2 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.03 parts of silane coupling agent and 0.8 parts of ethanol were mixed and ball-milled for 4 hours, the mixture was unloaded, and the solvent was evaporated under vacuum conditions to obtain adhesion-modified nano-titanium dioxide, and the adhesion-modified nano-titanium dioxide was placed in a blender and stirred at a speed of 20 r / s for 40 seconds to obtain modified nano-titanium dioxide after dispersion; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 1 mol / L sulfuric acid solution, the mass concentration of aniline monomer in the solution after addition is 0.08 g / L, stirring at a speed of 8 r / s for 40 minutes, adding modified nano-titanium dioxide with a mass content of 0.2% of the aniline monomer, continuing stirring at a speed of 8 r / s for 90 minutes, and then dropping 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate at a dropping rate of 0.0005 volume / s. After the dropwise addition is completed, reacting at a low temperature of -8°C, 15 MHz ultrasound and 1200 r / min stirring conditions for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 50-mesh sieve to obtain doped polyaniline; Step 3, preparing a functional component: adding 0.5 parts of calcium stearate, 0.5 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of magnesium oxide powder, and 2 parts of aluminum powder to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 4, preparing a spray-free antibacterial material: by weight, heat 100 parts of polyamide resin to 240°C, add 60 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain a spray-free antibacterial material for automobiles.

[0027] Comparative Example 3 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.4 parts of aniline monomer, 0.03 parts of silane coupling agent and 0.8 parts of ethanol were mixed and ball-milled for 4 hours, the mixture was unloaded, and the solvent was evaporated under vacuum conditions to obtain modified nano-titanium dioxide; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 1 mol / L sulfuric acid solution, the mass concentration of aniline monomer in the solution after addition is 0.08 g / L, stirring at a speed of 8 r / s for 40 minutes, adding modified nano-titanium dioxide with a mass ratio of 0.2% of the aniline monomer, continuing to stir at a speed of 8 r / s for 90 minutes, and then dropping 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate and 15 g / L copper sulfate at a dropping rate of 0.0005 volume / s. After the dropwise addition is completed, reacting at a low temperature of -8°C, 15 MHz ultrasound and 1200 r / min stirring conditions for 6 hours, filtering, washing with deionized water, and drying at 80°C to obtain doped polyaniline; Step 3, preparing a functional component: adding 0.5 parts of calcium stearate, 0.5 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of magnesium oxide powder, and 2 parts of aluminum powder to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 4, preparing a spray-free antibacterial material: by weight, heat 100 parts of polyamide resin to 240°C, add 60 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain a spray-free antibacterial material for automobiles.

[0028] Comparative Example 4 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.4 parts of aniline monomer, 0.03 parts of silane coupling agent and 0.8 parts of ethanol were mixed and ball-milled for 4 hours, the mixture was unloaded, and the solvent was evaporated under vacuum conditions to obtain adhesion-modified nano-titanium dioxide, and the adhesion-modified nano-titanium dioxide was placed in a blender and stirred at a speed of 40 r / s for 40 seconds to obtain modified nano-titanium dioxide after dispersion; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 1 mol / L sulfuric acid solution, the mass concentration of aniline monomer in the solution after addition is 0.08 g / L, stirring at a speed of 8 r / s for 40 minutes, adding modified nano-titanium dioxide with a mass content of 0.2% of the aniline monomer, continuing stirring at a speed of 8 r / s for 90 minutes, and then dropping 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate and 15 g / L copper sulfate at a dropping rate of 0.0005 volume / s. After the dropwise addition is completed, reacting at a low temperature of -8°C, 15 MHz ultrasound and 1200 r / min stirring conditions for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 50-mesh sieve to obtain doped polyaniline; Step 3, preparing a functional component: adding 0.5 parts of calcium stearate, 0.5 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of magnesium oxide powder, and 2 parts of aluminum powder to 100 parts of doped polyaniline by weight, and stirring and mixing at a speed of 1000 r / min to obtain a functional component; Step 4, preparing a spray-free antibacterial material: by weight, heat 100 parts of polyamide resin to 240°C, add 60 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain a spray-free antibacterial material for automobiles.

[0029] Comparative Example 5 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.4 parts of aniline monomer, 0.03 parts of silane coupling agent and 0.8 parts of ethanol were mixed and ball-milled for 4 hours, the mixture was unloaded, and the solvent was evaporated under vacuum conditions to obtain adhesion-modified nano-titanium dioxide, and the adhesion-modified nano-titanium dioxide was placed in a blender and stirred at a speed of 20 r / s for 40 seconds to obtain modified nano-titanium dioxide after dispersion; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 1 mol / L sulfuric acid solution, so that the mass concentration of aniline monomer in the solution is 0.08 g / L after addition, adding modified nano-titanium dioxide with a mass content of 0.2% of the aniline monomer, and dropping 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate and 15 g / L copper sulfate at a dropping rate of 0.0005 volume / s. After the dropwise addition is completed, reacting at a low temperature of -8°C and stirring at 800 rpm for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 50-mesh sieve to obtain doped polyaniline; Step 3, preparing a functional component: adding 0.5 parts of calcium stearate, 0.5 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of magnesium oxide powder, and 2 parts of aluminum powder to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 4, preparing a spray-free antibacterial material: by weight, heat 100 parts of polyamide resin to 240°C, add 60 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain a spray-free antibacterial material for automobiles.

[0030] Comparative Example 6 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.4 parts of aniline monomer, 0.03 parts of silane coupling agent and 0.8 parts of ethanol were mixed and ball-milled for 4 hours, the mixture was unloaded, and the solvent was evaporated under vacuum conditions to obtain adhesion-modified nano-titanium dioxide, and the adhesion-modified nano-titanium dioxide was placed in a blender and stirred at a speed of 20 r / s for 40 seconds to obtain modified nano-titanium dioxide after dispersion; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 1 mol / L sulfuric acid solution, the mass concentration of aniline monomer in the solution after addition is 0.08 g / L, stirring at a speed of 8 r / s for 40 minutes, adding modified nano-titanium dioxide with a mass content of 0.2% of the aniline monomer, continuing stirring at a speed of 8 r / s for 90 minutes, and then dropping 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate and 15 g / L copper sulfate at a dropping rate of 0.0005 volume / s. After the dropwise addition is completed, reacting at a low temperature of -8°C, 15 MHz ultrasound and 1200 r / min stirring conditions for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 50-mesh sieve to obtain doped polyaniline; Step 3, preparing a functional component: adding 0.5 parts of calcium stearate, 0.5 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of magnesium oxide powder, and 2 parts of aluminum powder to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 4, preparing a spray-free antibacterial material: by weight, heat 100 parts of polyamide resin to 240°C, add 10 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain a spray-free antibacterial material for automobiles.

[0031] Comparative Example 7 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.4 parts of aniline monomer, 0.03 parts of silane coupling agent and 0.8 parts of ethanol were mixed and ball-milled for 4 hours, the mixture was unloaded, and the solvent was evaporated under vacuum conditions to obtain adhesion-modified nano-titanium dioxide, and the adhesion-modified nano-titanium dioxide was placed in a blender and stirred at a speed of 20 r / s for 40 seconds to obtain modified nano-titanium dioxide after dispersion; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 1 mol / L sulfuric acid solution, the mass concentration of aniline monomer in the solution after addition is 0.08 g / L, stirring at a speed of 8 r / s for 40 minutes, adding modified nano-titanium dioxide with a mass content of 0.2% of the aniline monomer, continuing stirring at a speed of 8 r / s for 90 minutes, and then dropping 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate and 15 g / L copper sulfate at a dropping rate of 0.0005 volume / s. After the dropwise addition is completed, reacting at a low temperature of -8°C, 15 MHz ultrasound and 1200 r / min stirring conditions for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 50-mesh sieve to obtain doped polyaniline; Step 3, preparing a functional component: adding 0.5 parts of calcium stearate, 0.5 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of magnesium oxide powder, and 2 parts of aluminum powder to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 4, preparing a spray-free antibacterial material: by weight, heat 100 parts of polyamide resin to 240°C, add 100 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain a spray-free antibacterial material for automobiles.

[0032] Comparative Example 8 A spray-free antibacterial material for automobiles is prepared by the following steps: Step 1, preparing modified nano-titanium dioxide: by weight, 1 part of nano-titanium dioxide, 0.4 parts of aniline monomer, 0.03 parts of silane coupling agent and 0.8 parts of ethanol were mixed and ball-milled for 4 hours, the mixture was unloaded, and the solvent was evaporated under vacuum conditions to obtain adhesion-modified nano-titanium dioxide, and the adhesion-modified nano-titanium dioxide was placed in a blender and stirred at a speed of 20 r / s for 40 seconds to obtain modified nano-titanium dioxide after dispersion; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 1 mol / L sulfuric acid solution, until the mass concentration of aniline monomer in the solution is 0.08 g / L, stirring at a speed of 8 r / s for 40 minutes, adding modified nano-titanium dioxide with a mass ratio of 0.2% of the aniline monomer, continuing stirring at a speed of 8 r / s for 90 minutes, adding 1 volume of 1 mol / L sulfuric acid solution containing 200 g / L ammonium persulfate and 15 g / L copper sulfate, reacting at a low temperature of -8°C, 15 MHz ultrasound and stirring at 1200 r / min for 6 hours, filtering, washing with deionized water, drying at 80°C, and sieving through a 50-mesh sieve to obtain doped polyaniline; Step 3, preparing a functional component: adding 0.5 parts of calcium stearate, 0.5 parts of carbon black, 2 parts of zinc oxide powder, 2 parts of magnesium oxide powder, and 2 parts of aluminum powder to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 4, preparing a spray-free antibacterial material: by weight, heat 100 parts of polyamide resin to 240°C, add 60 parts of functional components under stirring conditions of 8r / s, continue stirring for 3 hours, then extrude, dry at 80°C, and granulate to obtain a spray-free antibacterial material for automobiles.

[0033] Test method: Gloss test: Refer to ISO2813 standard.

[0034] Spray-free surface condition test: Prepare a standard sample of 355×100×3.2mm, place it in a standard environment of 20℃ and 50% RH for 48 hours, and observe the weld line condition on the sample surface in a standard inspection light box; Antibacterial test: refer to the standard method of GB / T31402, and the test bacteria are Escherichia coli; Weather resistance test: Refer to SAE J2527, a special standard for automotive exterior parts; Abrasion resistance test: Refer to ASTM D3702 sample preparation, test conditions: pressure: 100N, speed: 0.5m / s, wear time: 2h, wear rate = wear mass / initial mass*100%.

[0035] Dirt resistance test: Prepare a 60mm×60mm×3.2mm sample, place it in the same outdoor environment for 2 weeks, and observe the surface condition.

[0036] Table 1 Serial number Glossiness (60°) No spraying condition Escherichia coli Gloss after aging (60°, 2000h) Color difference after aging (2000h) Wear rate% Surface condition after standing outdoors for 2 weeks Example 1 84 none 99.2 71 2.3 25 Easy to erase Example 2 86 none 99.3 72 2.4 23 Easy to erase Example 3 82 none 99.4 71 2.8 24 Easy to erase Comparative Example 1 74 obvious 98.6 68 1.7 36 Not easy to erase Comparative Example 2 75 obvious 98.2 59 1.8 45 Not easy to erase Comparative Example 3 73 obvious 97.6 64 1.4 38 Not easy to erase Comparative Example 4 62 obvious 98.4 61 1.8 41 Not easy to erase Comparative Example 5 64 obvious 98.3 53 1.6 42 Not easy to erase Comparative Example 6 57 obvious 83 61 1.6 38 Not easy to erase Comparative Example 7 82 obvious 99.3 65 1.9 39 Not easy to erase Comparative Example 8 66 obvious 98.2 58 1.8 37 Not easy to erase From the above results, it can be seen that the products prepared in Examples 1-3 are better than those in Comparative Examples 1-8 in terms of test results, which is due to the combination of formula and process.

[0037] The main difference between Comparative Example 1 and Example 1 is that no modified nano-titanium dioxide is added in Comparative Example 1. Therefore, Comparative Example 1 has poor weather resistance and insufficient wear resistance.

[0038] The main difference between Comparative Example 2 and Example 1 is that no aniline monomer is added in the preparation of the modified titanium dioxide in Comparative Example 2. The modified nano-titanium dioxide in Comparative Example 2 is not firmly bonded to polyaniline, resulting in poor performance.

[0039] Poor dispersion can lead to degraded performance. The main difference between Comparative Example 3 and Example 1 is that the modified nano-titanium dioxide prepared in step 1 and the doped polyaniline prepared in step 3 were not fully dispersed. The main difference between Comparative Example 4 and Example 1 is that the mixing was performed at a speed of 1000 r / min in step 3, resulting in the melting and adhesion of the polyaniline in some functional components. The main difference between Comparative Examples 5 and 8 and Example 1 is that the stirring was not sufficient in step 2.

[0040] The main difference between Comparative Example 6 and Example 1 is that too little functional component was added in step 4. The main difference between Comparative Example 7 and Example 1 is that too much functional component was added in step 4. From the antibacterial test, Comparative Example 6 confirms the antibacterial effectiveness of the functional component, with polyaniline playing the main role.

[0041] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a spray-free antibacterial material for automobiles, characterized in that: The following steps are involved: Step 1, preparing modified nano-titanium dioxide: by weight, mixing 1 part of nano-titanium dioxide, 0.3-0.5 parts of aniline monomer, 0.01-0.05 parts of silane coupling agent and 0.5 parts to 1 part of organic solvent, ball milling for 3-5 hours, unloading, evaporating the solvent under vacuum conditions to obtain adhesion modified nano-titanium dioxide, and dispersing to obtain modified nano-titanium dioxide; Step 2, preparing doped polyaniline: adding aniline monomer to 1 volume of 0.8 mol / L-1.2 mol / L sulfuric acid solution, so that the mass concentration of aniline monomer in the solution is 0.05 g / L-0.15 g / L after addition, stirring at a speed of 5-10 r / s for 30 min-60 min, adding modified nano-titanium dioxide with a mass ratio of 0.1%-0.3% of the mass of aniline monomer, continuing stirring at a speed of 5-10 r / s for 60 min-120 min, and then dropwise adding 0.5 volume-1.5 volume of a strong acid solution containing ammonium persulfate and copper sulfate. After the dropwise addition is completed, reacting under low temperature, ultrasonic and stirring conditions for 4 h-8 h, filtering, washing, drying, and sieving to obtain doped polyaniline; The strong acid solution is a 0.8 mol / L-1.2 mol / L sulfuric acid solution or a hydrochloric acid solution with a mass concentration of 20%-35%; The concentration of ammonium persulfate in the strong acid solution is 200g / L-250g / L, and the concentration of copper sulfate is 10-20g / L; Step 3, preparing a functional component: adding 0.5-1 part of a dispersant, 0.5-1 part of a weathering agent, and 5-10 parts of a filler to 100 parts of doped polyaniline by weight, and mixing them uniformly with an air flow mixer to obtain a functional component; Step 4, preparing a spray-free antibacterial material: heating 100 parts of polyamide resin to 220-300°C by weight, adding 30-70 parts of functional components under stirring, continuing stirring for 2-4 hours, then extruding, drying, and granulating to obtain a spray-free antibacterial material for automobiles.

2. The method for preparing the spray-free antibacterial material for automobiles according to claim 1, characterized in that: The dispersant is one or more of calcium stearate, zinc stearate and copolyamide wax.

3. The method for preparing the spray-free antibacterial material for automobiles according to claim 1, wherein: The weathering additive is carbon black.

4. The method for preparing the spray-free antibacterial material for automobiles according to claim 1, wherein: The filler is one or more of zinc oxide powder, magnesium oxide powder, aluminum powder, copper-gold powder, and silicon dioxide powder.

5. The method for preparing the spray-free antibacterial material for automobiles according to claim 1, characterized in that: In step 1, the organic solvent is ethanol; the dispersion method is: putting the adhesion-modified nano-titanium dioxide into a blender and stirring at a speed of 10 rpm to 30 rpm for 20 s to 60 s.

6. The method for preparing the spray-free antibacterial material for automobiles according to claim 1, characterized in that: In step 2, the low temperature, ultrasound and stirring conditions correspond to: -5°C to -10°C, 10 MHz to 20 MHz, 1000 r / min to 2000 r / min; the drying temperature is 60°C to 90°C; and the screening method is to obtain the doped polyaniline by sieving through a 20-50 mesh slapping sieve.

7. The method for preparing the spray-free antibacterial material for automobiles according to claim 1, wherein: In step 2, 0.5 volumes to 1.5 volumes of a strong acid solution containing ammonium persulfate and copper sulfate are added dropwise at a rate of 0.0005 volumes / s to 0.0008 volumes / s.

8. The method for preparing the spray-free antibacterial material for automobiles according to claim 1, wherein: In step 4, the stirring rate is 5 r / s-10 r / s, and the drying temperature is 60° C.-90° C.

9. A spray-free antibacterial material for automobiles prepared by the method for preparing the spray-free antibacterial material for automobiles according to any one of claims 1 to 8.