阅读说明：本技术 一种汽车内饰吸音材料及其制备方法 (Automotive interior sound-absorbing material and preparation method thereof ) 是由 林冰 黄云龙 刘雨悦 于 2021-09-28 设计创作，主要内容包括：本发明提供一种汽车内饰吸音材料及其制备方法,所述汽车内饰吸音材料包括以下原料聚丙烯40～50份、乙烯-醋酸乙烯共聚物20～30份、秸秆3～8份、硼砂4～10份、二氧化钛1～4份、异抗坏血酸0.3～1.4份、改性混合液2～5份、六氟铝酸钠2～4份、硬脂酸锌1～4份、防霉剂0.3～0.6份；所述汽车内饰吸音材料的制备方法包括以下步骤：A、准备原料；B、用丙酮将改性混合液稀释得改性混合液稀释液；C、由秸秆、硼砂、二氧化钛制得烧结物；D、烧结物在改性混合液稀释液中改性得到混合物料B；E、物料的初混、高速混合、挤出、造粒即得汽车内饰吸音材料。本发明提出的吸音材料,具有良好的吸音性、防霉性、抑菌性和阻燃性,且甲醛的释放量低。(The invention provides an automotive interior sound-absorbing material and a preparation method thereof, wherein the automotive interior sound-absorbing material comprises the following raw materials of 40-50 parts of polypropylene, 20-30 parts of ethylene-vinyl acetate copolymer, 3-8 parts of straws, 4-10 parts of borax, 1-4 parts of titanium dioxide, 0.3-1.4 parts of isoascorbic acid, 2-5 parts of modified mixed solution, 2-4 parts of sodium hexafluoroaluminate, 1-4 parts of zinc stearate and 0.3-0.6 part of mildew preventive; the preparation method of the sound-absorbing material for the automotive interior comprises the following steps: A. preparing raw materials; B. diluting the modified mixed solution with acetone to obtain a modified mixed solution diluent; C. preparing sinter from straw, borax and titanium dioxide; D. modifying the sinter in the modified mixed solution diluent to obtain a mixed material B; E. and (3) carrying out primary mixing, high-speed mixing, extrusion and granulation on the materials to obtain the automotive interior sound-absorbing material. The sound-absorbing material provided by the invention has good sound-absorbing property, mildew resistance, antibacterial property and flame retardance, and the release amount of formaldehyde is low.)

1. The sound-absorbing material for the automotive interior is characterized by comprising the following raw materials in parts by weight: 40-50 parts of polypropylene, 20-30 parts of ethylene-vinyl acetate copolymer, 3-8 parts of straw, 4-10 parts of borax, 1-4 parts of titanium dioxide, 0.3-1.4 parts of isoascorbic acid, 2-5 parts of modified mixed solution, 2-4 parts of sodium hexafluoroaluminate, 1-4 parts of zinc stearate and 0.3-0.6 part of mildew preventive.

2. The automotive interior sound-absorbing material of claim 1, wherein the automotive interior sound-absorbing material comprises the following raw materials in parts by weight: 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive.

3. The sound-absorbing material for automobile interior according to claim 1 or 2, wherein the modified mixed solution is prepared by the following method:

s1, heating and dissolving N, N, N ', N' -tetramethyl formamidine hexafluorophosphate in a proper amount of acetone, adding a silane coupling agent accounting for 3-6% of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, absolute ethyl alcohol accounting for 5-8 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate and isopropanol accounting for 1-4 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, and mechanically stirring for 1-2 hours at 50-60 ℃ to obtain a mixed intermediate solution;

s2, adding 2-mercaptobenzothiazole accounting for 10% -15% of the mass of the N, N, N ', N' -tetramethyl chloroformamidine hexafluorophosphate into the mixed intermediate liquid prepared in the step S1, mechanically stirring for 1-2 hours in a circulating water condensation state, concentrating under reduced pressure, drying in vacuum, and cooling to room temperature to obtain the modified mixed liquid.

4. The sound-absorbing material for automobile interiors according to claim 3, wherein the rotation speed of the mechanical stirring in steps S1 and S2 is 400-600 r/min.

5. The sound-absorbing material for automobile interiors according to claim 3, wherein in step S2, the temperature of concentration under reduced pressure is 40-45 ℃, the temperature of vacuum drying is 50-55 ℃, and the time of vacuum drying is 4-8 h.

6. The sound absorbing material for automobile interiors according to claim 1 or 2, wherein the mildew preventive is prepared by mixing 3-6 mass percent of: 1, adding 6-caprolactone accounting for 5-8% of the total mass of the copper sulfate and the lauryl sodium sulfate and absolute ethyl alcohol accounting for 5-10 times of the total mass of the copper sulfate and the lauryl sodium sulfate, performing ultrasonic dispersion for 40-60 min, performing reduced pressure concentration, and drying to obtain the copper sulfate/lauryl sodium sulfate composite material.

7. The preparation method of the sound-absorbing material for the automotive interior is characterized by comprising the following steps of:

A. weighing 40-50 parts of polypropylene, 20-30 parts of ethylene-vinyl acetate copolymer, 3-8 parts of straw, 4-10 parts of borax, 1-4 parts of titanium dioxide, 0.3-1.4 parts of isoascorbic acid, 2-5 parts of modified mixed solution, 2-4 parts of sodium hexafluoroaluminate, 1-4 parts of zinc stearate and 0.3-0.6 part of mildew preventive for later use;

B. adding acetone which is 15-20 times of the weight of the modified mixed solution into the modified mixed solution weighed in the step A, and performing ultrasonic dispersion for 20-30 min to obtain modified mixed solution diluent;

C. mixing the straws weighed in the step A, borax and titanium dioxide to obtain a mixed material A, adding water accounting for 30% of the mass of the mixed material A into the mixed material A, mixing and stirring, making into small balls with the diameter of about 20mm by a ball forming machine, drying in an oven, sintering at 800-850 ℃ for 15-20 min, and cooling to room temperature to obtain a sinter;

D. adding the sinter obtained in the step C into the modified mixed solution diluent obtained in the step B, reacting for 20-30 min at 50-55 ℃, cooling to room temperature, filtering, and drying filter residues to obtain a mixed material B;

E. and (3) placing the polypropylene, the ethylene-vinyl acetate copolymer, the isoascorbic acid, the sodium hexafluoroaluminate, the zinc stearate and the mildew preventive which are weighed in the step (A) into a mixer, primarily mixing for 5-10 min, adding the mixed material B prepared in the step (D), mixing for 2-5 min at the rotating speed of 1000-1500 r/min, extruding by a double-screw extruder, and granulating by a granulator to obtain the automotive interior sound-absorbing material.

Technical Field

The invention relates to the technical field of automobile decoration materials, in particular to an automobile interior decoration sound-absorbing material and a preparation method thereof.

Background

With the improvement of living standard of people, automobiles become an indispensable part of daily life of people, and the annual demand is increasing continuously. On the premise of ensuring the material conditions, people begin to pay more and more attention to health problems, and the environment-friendly automobile decoration material becomes the mainstream development trend of the automobile decoration material. The safety performance of the automotive interior material is the most important of the automotive interior materials, and people inevitably contact the automotive interior during the use of the automobile, so the performance of the automotive interior is the most significant position in the aspect of evaluating the automotive performance. The external noise can interfere with a driver and a user in the automobile, and the sound absorption performance of the automobile interior material can be improved during design of the automobile so as to reduce the influence of the external noise on the driver and the user in the automobile. However, the existing sound-absorbing materials used for automobiles are various in types and different in performance, and a large amount of combustible substances are often filled in the existing sound-absorbing materials, so that the safety performance of the automobiles is reduced, and the existing sound-absorbing materials are single in function, so that the sound-absorbing effect is generally improved slightly in performance in other aspects, for example, the content of organic volatile matters such as formaldehyde is high, and the environment-friendly development concept is not met; the sound absorbing material is easily mildewed, especially in rainy season. Based on the defects in the prior art, the invention provides an automotive interior sound-absorbing material and a preparation method thereof.

Disclosure of Invention

The invention aims to solve the problems that the safety performance of an automobile is reduced due to the fact that a large amount of combustible materials are filled in the existing sound-absorbing material for the interior trim of the automobile, and the automobile is easy to mildew due to the fact that the content of organic volatile matters such as formaldehyde is high.

In order to achieve the purpose, the invention is realized by the following technical scheme:

the sound-absorbing material for the automotive interior comprises the following raw materials in parts by weight: 40-50 parts of polypropylene, 20-30 parts of ethylene-vinyl acetate copolymer, 3-8 parts of straw, 4-10 parts of borax, 1-4 parts of titanium dioxide, 0.3-1.4 parts of isoascorbic acid, 2-5 parts of modified mixed solution, 2-4 parts of sodium hexafluoroaluminate, 1-4 parts of zinc stearate and 0.3-0.6 part of mildew preventive

Preferably, the sound-absorbing material for the automotive interior comprises the following raw materials in parts by weight: 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive.

Preferably, the modified mixed solution is prepared by the following method:

s1, heating and dissolving N, N, N ', N' -tetramethyl formamidine hexafluorophosphate in a proper amount of acetone, adding a silane coupling agent accounting for 3-6% of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, absolute ethyl alcohol accounting for 5-8 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate and isopropanol accounting for 1-4 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, and mechanically stirring for 1-2 hours at 50-60 ℃ to obtain a mixed intermediate solution;

s2, adding 2-mercaptobenzothiazole accounting for 10% -15% of the mass of the N, N, N ', N' -tetramethyl chloroformamidine hexafluorophosphate into the mixed intermediate liquid prepared in the step S1, mechanically stirring for 1-2 hours in a circulating water condensation state, concentrating under reduced pressure, drying in vacuum, and cooling to room temperature to obtain the modified mixed liquid.

Preferably, in the step S1 and the step S2, the rotation speed of the mechanical stirring is 400 to 600 r/min.

Preferably, in step S2, the temperature for vacuum concentration is 40-45 ℃, the temperature for vacuum drying is 50-55 ℃, and the time for vacuum drying is 4-8 h.

Preferably, the mildew preventive is prepared from the following components in a mass ratio of 3-6: 1, adding 6-caprolactone accounting for 5-8% of the total mass of the copper sulfate and the lauryl sodium sulfate and absolute ethyl alcohol accounting for 5-10 times of the total mass of the copper sulfate and the lauryl sodium sulfate, performing ultrasonic dispersion for 40-60 min, performing reduced pressure concentration, and drying to obtain the copper sulfate/lauryl sodium sulfate composite material.

The invention also provides a preparation method of the sound-absorbing material for the automotive interior, which is characterized by comprising the following steps of:

A. weighing 40-50 parts of polypropylene, 20-30 parts of ethylene-vinyl acetate copolymer, 3-8 parts of straw, 4-10 parts of borax, 1-4 parts of titanium dioxide, 0.3-1.4 parts of isoascorbic acid, 2-5 parts of modified mixed solution, 2-4 parts of sodium hexafluoroaluminate, 1-4 parts of zinc stearate and 0.3-0.6 part of mildew preventive for later use;

B. adding acetone which is 15-20 times of the weight of the modified mixed solution into the modified mixed solution weighed in the step A, and performing ultrasonic dispersion for 20-30 min to obtain modified mixed solution diluent;

C. mixing the straws weighed in the step A, borax and titanium dioxide to obtain a mixed material A, adding water accounting for 30% of the mass of the mixed material A into the mixed material A, mixing and stirring, making into small balls with the diameter of about 20mm by a ball forming machine, drying in an oven, sintering at 800-850 ℃ for 15-20 min, and cooling to room temperature to obtain a sinter;

D. adding the sinter obtained in the step C into the modified mixed solution diluent obtained in the step B, reacting for 20-30 min at 50-55 ℃, cooling to room temperature, filtering, and drying filter residues to obtain a mixed material B;

E. and (3) placing the polypropylene, the ethylene-vinyl acetate copolymer, the isoascorbic acid, the sodium hexafluoroaluminate, the zinc stearate and the mildew preventive which are weighed in the step (A) into a mixer, primarily mixing for 5-10 min, adding the mixed material B prepared in the step (D), mixing for 2-5 min at the rotating speed of 1000-1500 r/min, extruding by a double-screw extruder, and granulating by a granulator to obtain the automotive interior sound-absorbing material.

Compared with the prior art, the sound-absorbing material provided by the invention has the advantages that:

1. the sound-absorbing material provided by the invention is reasonable in formula, the polypropylene and the ethylene-vinyl acetate copolymer are used as main raw materials, the sound-absorbing material is endowed with good mechanical property and elasticity, the flame retardance, the sound-absorbing property and the mildew-proof property of the sound-absorbing material are improved by adding the straw, the borax, the titanium dioxide, the isoascorbic acid, the modified mixed solution, the sodium hexafluoroaluminate, the zinc stearate and the mildew-proof agent, only a small amount of formaldehyde is released, the environment-friendly development concept is met, the problems that the safety performance of an automobile is reduced due to the fact that a large amount of combustible materials are filled in the existing sound-absorbing material for automobile interior trim, the content of organic volatile matters such as formaldehyde is high, and the mildew easily occurs are solved, and the sound-absorbing material has good economic benefit and popularization value.

2. The invention prepares the sinter with the porous structure by the straws, the borax and the titanium dioxide, and is matched with the modification of the sinter in the modified mixed diluent to enhance the flame retardant property and the sound absorption property of the sound absorption material, and can ensure that the release amount of formaldehyde is lower, so as to compound the development concept of environmental friendliness, wherein the modified mixed diluent has a remarkable promoting effect on the improvement of the flame retardant property and the sound absorption property by the treatment of the sinter, and particularly the N, N, N ', N' -tetramethyl chloroformamidine hexafluorophosphate in the modified mixed diluent can remarkably improve the flame retardant property of the sound absorption material and improve the sound absorption property of the sound absorption material.

3. The mildew preventive used in the invention has a remarkable promotion effect on the mildew resistance of the sound-absorbing material, and the mildew resistance and the bacteriostatic property of the copper sulfate are remarkably improved by adding the commonly used mildew preventive copper sulfate and matching with the lauryl sodium sulfate and the 6-caprolactone in a reasonable proportion.

Detailed Description

The present invention will be further illustrated with reference to the following specific examples.

Example 1

The invention provides an automotive interior sound-absorbing material which comprises the following raw materials in parts by weight: 40 parts of polypropylene, 30 parts of ethylene-vinyl acetate copolymer, 3 parts of straw, 4 parts of borax, 4 parts of titanium dioxide, 0.3 part of isoascorbic acid, 5 parts of modified mixed solution, 4 parts of sodium hexafluoroaluminate, 1 part of zinc stearate and 0.6 part of mildew preventive;

the modified mixed solution is prepared by the following method:

s1, heating and dissolving N, N, N ', N' -tetramethyl formamidine hexafluorophosphate in a proper amount of acetone, adding a silane coupling agent accounting for 3% of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, absolute ethyl alcohol accounting for 8 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate and isopropanol accounting for 1 time of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, and mechanically stirring at 50 ℃ and the rotating speed of 600r/min for 1h to obtain a mixed intermediate solution;

s2, adding 2-mercaptobenzothiazole accounting for 10% of the mass of the N, N, N ', N' -tetramethyl chloroformamidine hexafluorophosphate into the mixed intermediate liquid prepared in the step S1, mechanically stirring for 1h at the rotating speed of 600r/min in the state of circulating water condensation, decompressing and concentrating at 40 ℃, vacuum drying for 8h at 50 ℃, and cooling to room temperature to obtain a modified mixed liquid;

the mildew preventive is prepared from the following components in percentage by mass of 3: 1, adding 6-caprolactone accounting for 8 percent of the total mass of the copper sulfate and the lauryl sodium sulfate and absolute ethyl alcohol accounting for 5 times of the total mass of the copper sulfate and the lauryl sodium sulfate, performing ultrasonic dispersion for 60min, performing reduced pressure concentration, and drying to obtain the copper sulfate/lauryl sodium sulfate composite material;

a preparation method of an automotive interior sound-absorbing material comprises the following steps:

A. weighing 40 parts of polypropylene, 30 parts of ethylene-vinyl acetate copolymer, 3 parts of straw, 4 parts of borax, 4 parts of titanium dioxide, 0.3 part of isoascorbic acid, 5 parts of modified mixed solution, 4 parts of sodium hexafluoroaluminate, 1 part of zinc stearate and 0.6 part of mildew preventive for later use;

B. adding acetone which is 15 times of the modified mixed solution in mass into the modified mixed solution weighed in the step A, and performing ultrasonic dispersion for 20min to obtain modified mixed solution diluent;

C. mixing the straws weighed in the step A, borax and titanium dioxide to obtain a mixed material A, adding water accounting for 30% of the mass of the mixed material A into the mixed material A, mixing and stirring, preparing into small balls with the diameter of about 20mm by a ball forming machine, drying in an oven, sintering at 800 ℃ for 20min, and cooling to room temperature to obtain a sinter;

D. c, adding the sinter obtained in the step C into the modified mixed solution diluent obtained in the step B, reacting at 50 ℃ for 30min, cooling to room temperature, filtering, and drying filter residues to obtain a mixed material B;

E. and (3) placing the polypropylene, the ethylene-vinyl acetate copolymer, the isoascorbic acid, the sodium hexafluoroaluminate, the zinc stearate and the mildew preventive which are weighed in the step (A) into a mixer, primarily mixing for 5min, adding the mixed material B prepared in the step (D), mixing for 2min at the rotating speed of 1500r/min, extruding by a double-screw extruder, and granulating by a granulator to obtain the automotive interior sound-absorbing material.

Example 2

The invention provides an automotive interior sound-absorbing material which comprises the following raw materials in parts by weight: 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive;

the modified mixed solution is prepared by the following method:

s1, heating and dissolving N, N, N ', N' -tetramethyl formamidine hexafluorophosphate in a proper amount of acetone, adding a silane coupling agent accounting for 4% of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, absolute ethyl alcohol accounting for 6 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate and isopropanol accounting for 2 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, and mechanically stirring at 55 ℃ and the rotating speed of 500r/min for 2 hours to obtain a mixed intermediate solution;

s2, adding 2-mercaptobenzothiazole accounting for 12% of the mass of the N, N, N ', N' -tetramethyl chloroformamidine hexafluorophosphate into the mixed intermediate liquid prepared in the step S1, mechanically stirring for 2 hours at the rotating speed of 500r/min under the state of circulating water condensation, decompressing and concentrating at 45 ℃, vacuum drying for 6 hours at 55 ℃, and cooling to room temperature to obtain a modified mixed liquid;

the mildew preventive is prepared from the following components in percentage by mass: 1, adding 6-caprolactone 6 percent of the total mass of the copper sulfate and the lauryl sodium sulfate and absolute ethyl alcohol 8 times of the total mass of the copper sulfate and the lauryl sodium sulfate, ultrasonically dispersing for 60min, concentrating under reduced pressure, and drying to obtain the copper sulfate/lauryl sodium sulfate composite material;

a preparation method of an automotive interior sound-absorbing material comprises the following steps:

A. weighing raw materials according to 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive for later use;

B. adding acetone which is 20 times of the modified mixed solution in mass into the modified mixed solution weighed in the step A, and performing ultrasonic dispersion for 25min to obtain modified mixed solution diluent;

C. mixing the straws weighed in the step A, borax and titanium dioxide to obtain a mixed material A, adding water accounting for 30% of the mass of the mixed material A into the mixed material A, mixing and stirring, making into small balls with the diameter of about 20mm by a ball forming machine, putting into an oven for drying, sintering at 850 ℃ for 15min, and cooling to room temperature to obtain a sinter;

D. adding the sinter obtained in the step C into the modified mixed solution diluent obtained in the step B, reacting at 55 ℃ for 20min, cooling to room temperature, filtering, and drying filter residues to obtain a mixed material B;

E. and (3) placing the polypropylene, the ethylene-vinyl acetate copolymer, the isoascorbic acid, the sodium hexafluoroaluminate, the zinc stearate and the mildew preventive which are weighed in the step (A) into a mixer, primarily mixing for 8min, adding the mixed material B prepared in the step (D), mixing for 4min at the rotating speed of 1200r/min, extruding by a double-screw extruder, and granulating by a granulator to obtain the automotive interior sound-absorbing material.

Example 3

The invention provides an automotive interior sound-absorbing material which comprises the following raw materials in parts by weight: 50 parts of polypropylene, 20 parts of ethylene-vinyl acetate copolymer, 8 parts of straw, 10 parts of borax, 1 part of titanium dioxide, 1.4 parts of isoascorbic acid, 2 parts of modified mixed solution, 2 parts of sodium hexafluoroaluminate, 4 parts of zinc stearate and 0.3 part of mildew preventive;

the modified mixed solution is prepared by the following method:

s1, heating and dissolving N, N, N ', N' -tetramethyl formamidine hexafluorophosphate in a proper amount of acetone, adding a silane coupling agent accounting for 6% of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, absolute ethyl alcohol accounting for 5 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate and isopropyl alcohol accounting for 4 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, and mechanically stirring at the rotating speed of 400r/min for 2 hours at the temperature of 60 ℃ to obtain a mixed intermediate solution;

s2, adding 15% by mass of 2-mercaptobenzothiazole of N, N, N ', N' -tetramethyl chloroformamidine hexafluorophosphate into the mixed intermediate liquid prepared in the step S1, mechanically stirring for 2 hours at the rotating speed of 400r/min under the state of circulating water condensation, decompressing and concentrating at 45 ℃, vacuum drying for 4 hours at 55 ℃, and cooling to room temperature to obtain a modified mixed liquid;

the mildew preventive is prepared from the following components in percentage by mass of 6: 1, adding 6-caprolactone accounting for 5 percent of the total mass of the copper sulfate and the lauryl sodium sulfate and absolute ethyl alcohol accounting for 10 times of the total mass of the copper sulfate and the lauryl sodium sulfate, performing ultrasonic dispersion for 40min, and performing reduced pressure concentration and drying to obtain the copper sulfate/lauryl sodium sulfate composite material;

a preparation method of an automotive interior sound-absorbing material comprises the following steps:

A. weighing 50 parts of polypropylene, 20 parts of ethylene-vinyl acetate copolymer, 8 parts of straw, 10 parts of borax, 1 part of titanium dioxide, 1.4 parts of isoascorbic acid, 2 parts of modified mixed solution, 2 parts of sodium hexafluoroaluminate, 4 parts of zinc stearate and 0.3 part of mildew preventive for later use;

B. adding acetone which is 20 times of the modified mixed solution in mass into the modified mixed solution weighed in the step A, and performing ultrasonic dispersion for 30min to obtain modified mixed solution diluent;

C. mixing the straws weighed in the step A, borax and titanium dioxide to obtain a mixed material A, adding water accounting for 30% of the mass of the mixed material A into the mixed material A, mixing and stirring, making into small balls with the diameter of about 20mm by a ball forming machine, putting into an oven for drying, sintering at 850 ℃ for 15min, and cooling to room temperature to obtain a sinter;

D. adding the sinter obtained in the step C into the modified mixed solution diluent obtained in the step B, reacting at 55 ℃ for 20min, cooling to room temperature, filtering, and drying filter residues to obtain a mixed material B;

E. and (3) placing the polypropylene, the ethylene-vinyl acetate copolymer, the isoascorbic acid, the sodium hexafluoroaluminate, the zinc stearate and the mildew preventive which are weighed in the step (A) into a mixer, primarily mixing for 10min, adding the mixed material B prepared in the step (D), mixing for 5min at the rotating speed of 1000r/min, extruding by a double-screw extruder, and granulating by a granulator to obtain the automotive interior sound-absorbing material.

Comparative example 1

The sound-absorbing material for the automotive interior comprises the following raw materials in parts by weight: 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive;

the mildew preventive is prepared from the following components in percentage by mass: 1, adding 6-caprolactone 6 percent of the total mass of the copper sulfate and the lauryl sodium sulfate and absolute ethyl alcohol 8 times of the total mass of the copper sulfate and the lauryl sodium sulfate, ultrasonically dispersing for 60min, concentrating under reduced pressure, and drying to obtain the copper sulfate/lauryl sodium sulfate composite material;

a preparation method of an automotive interior sound-absorbing material comprises the following steps:

A. weighing raw materials according to 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive for later use;

B. taking the same amount of acetone as in the step B of the embodiment 2, and ultrasonically dispersing for 25 min;

C. mixing the straws weighed in the step A, borax and titanium dioxide to obtain a mixed material A, adding water accounting for 30% of the mass of the mixed material A into the mixed material A, mixing and stirring, making into small balls with the diameter of about 20mm by a ball forming machine, putting into an oven for drying, sintering at 850 ℃ for 15min, and cooling to room temperature to obtain a sinter;

D. c, adding the sinter obtained in the step C into acetone obtained in the step B, reacting for 20min at 55 ℃, cooling to room temperature, filtering, and drying filter residues to obtain a mixed material B;

E. and (3) placing the polypropylene, the ethylene-vinyl acetate copolymer, the isoascorbic acid, the sodium hexafluoroaluminate, the zinc stearate and the mildew preventive which are weighed in the step (A) into a mixer, primarily mixing for 8min, adding the mixed material B prepared in the step (D), mixing for 4min at the rotating speed of 1200r/min, extruding by a double-screw extruder, and granulating by a granulator to obtain the automotive interior sound-absorbing material.

Comparative example 2

The sound-absorbing material for the automotive interior comprises the following raw materials in parts by weight: 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive;

the modified mixed solution is prepared by the following method:

s1, adding 4% by mass of a silane coupling agent of N, N, N ', N' -tetramethylformamidine hexafluorophosphate in step S1 of example 2, 6 times by mass of absolute ethanol of N, N, N ', N' -tetramethylformamidine hexafluorophosphate in step S1 of example 2, and 2 times by mass of isopropanol of N, N, N ', N' -tetramethylformamidine hexafluorophosphate in step S1 of example 2 to acetone in the same amount as in step S1 of example 2, and mechanically stirring at 55 ℃ for 2 hours at a rotation speed of 500r/min to obtain a mixed intermediate solution;

s2, adding 2-mercaptobenzothiazole accounting for 12% of the mass of the N, N, N ', N' -tetramethyl chloroformamidine hexafluorophosphate in the step S1 of the example 2 into the mixed intermediate solution prepared in the step S1, mechanically stirring for 2 hours at the rotating speed of 500r/min under the condition of circulating water condensation, decompressing and concentrating at 45 ℃, vacuum drying for 6 hours at 55 ℃, and cooling to room temperature to obtain a modified mixed solution;

the mildew preventive is prepared from the following components in percentage by mass: 1, adding 6-caprolactone 6 percent of the total mass of the copper sulfate and the lauryl sodium sulfate and absolute ethyl alcohol 8 times of the total mass of the copper sulfate and the lauryl sodium sulfate, ultrasonically dispersing for 60min, concentrating under reduced pressure, and drying to obtain the copper sulfate/lauryl sodium sulfate composite material;

a preparation method of an automotive interior sound-absorbing material comprises the following steps:

A. weighing raw materials according to 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive for later use;

B. adding acetone which is 20 times of the modified mixed solution in mass into the modified mixed solution weighed in the step A, and performing ultrasonic dispersion for 25min to obtain modified mixed solution diluent;

C. mixing the straws weighed in the step A, borax and titanium dioxide to obtain a mixed material A, adding water accounting for 30% of the mass of the mixed material A into the mixed material A, mixing and stirring, making into small balls with the diameter of about 20mm by a ball forming machine, putting into an oven for drying, sintering at 850 ℃ for 15min, and cooling to room temperature to obtain a sinter;

D. adding the sinter obtained in the step C into the modified mixed solution diluent obtained in the step B, reacting at 55 ℃ for 20min, cooling to room temperature, filtering, and drying filter residues to obtain a mixed material B;

E. and (3) placing the polypropylene, the ethylene-vinyl acetate copolymer, the isoascorbic acid, the sodium hexafluoroaluminate, the zinc stearate and the mildew preventive which are weighed in the step (A) into a mixer, primarily mixing for 8min, adding the mixed material B prepared in the step (D), mixing for 4min at the rotating speed of 1200r/min, extruding by a double-screw extruder, and granulating by a granulator to obtain the automotive interior sound-absorbing material.

Comparative example 3

The invention provides an automotive interior sound-absorbing material which comprises the following raw materials in parts by weight: 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive;

the modified mixed solution is prepared by the following method:

s1, heating and dissolving N, N, N ', N' -tetramethyl formamidine hexafluorophosphate in a proper amount of acetone, adding a silane coupling agent accounting for 4% of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, absolute ethyl alcohol accounting for 6 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate and isopropanol accounting for 2 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, and mechanically stirring at 55 ℃ and the rotating speed of 500r/min for 2 hours to obtain a mixed intermediate solution;

s2, adding 2-mercaptobenzothiazole accounting for 12% of the mass of the N, N, N ', N' -tetramethyl chloroformamidine hexafluorophosphate into the mixed intermediate liquid prepared in the step S1, mechanically stirring for 2 hours at the rotating speed of 500r/min under the state of circulating water condensation, decompressing and concentrating at 45 ℃, vacuum drying for 6 hours at 55 ℃, and cooling to room temperature to obtain a modified mixed liquid;

the mildew preventive is prepared from the following components in percentage by mass: 1, adding 6-caprolactone 6 percent of the total mass of the copper sulfate and the lauryl sodium sulfate and absolute ethyl alcohol 8 times of the total mass of the copper sulfate and the lauryl sodium sulfate, ultrasonically dispersing for 60min, concentrating under reduced pressure, and drying to obtain the copper sulfate/lauryl sodium sulfate composite material;

a preparation method of an automotive interior sound-absorbing material comprises the following steps:

A. weighing raw materials according to 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive for later use;

B. adding acetone which is 20 times of the modified mixed solution in mass into the modified mixed solution weighed in the step A, and performing ultrasonic dispersion for 25min to obtain modified mixed solution diluent;

C. mixing the straws weighed in the step A and borax to obtain a mixed material A, adding water accounting for 30% of the mass of the mixed material A into the mixed material A, mixing and stirring, making into small balls with the diameter of about 20mm by a ball forming machine, putting into an oven for drying, sintering at 850 ℃ for 15min, and cooling to room temperature to obtain a sinter;

D. adding the sinter obtained in the step C into the modified mixed solution diluent obtained in the step B, reacting at 55 ℃ for 20min, cooling to room temperature, filtering, and drying filter residues to obtain a mixed material B;

E. and (3) placing the polypropylene, the ethylene-vinyl acetate copolymer, the isoascorbic acid, the sodium hexafluoroaluminate, the zinc stearate and the mildew preventive which are weighed in the step (A) into a mixer, primarily mixing for 8min, adding the mixed material B prepared in the step (D), mixing for 4min at the rotating speed of 1200r/min, extruding by a double-screw extruder, and granulating by a granulator to obtain the automotive interior sound-absorbing material.

Comparative example 4

The invention provides an automotive interior sound-absorbing material which comprises the following raw materials in parts by weight: 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive;

the modified mixed solution is prepared by the following method:

s1, heating and dissolving N, N, N ', N' -tetramethyl formamidine hexafluorophosphate in a proper amount of acetone, adding a silane coupling agent accounting for 4% of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, absolute ethyl alcohol accounting for 6 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate and isopropanol accounting for 2 times of the mass of the N, N, N ', N' -tetramethyl formamidine hexafluorophosphate, and mechanically stirring at 55 ℃ and the rotating speed of 500r/min for 2 hours to obtain a mixed intermediate solution;

s2, adding 2-mercaptobenzothiazole accounting for 12% of the mass of the N, N, N ', N' -tetramethyl chloroformamidine hexafluorophosphate into the mixed intermediate liquid prepared in the step S1, mechanically stirring for 2 hours at the rotating speed of 500r/min under the state of circulating water condensation, decompressing and concentrating at 45 ℃, vacuum drying for 6 hours at 55 ℃, and cooling to room temperature to obtain a modified mixed liquid;

the mildew preventive is prepared from the following components in percentage by mass: 1, adding absolute ethyl alcohol which is 8 times of the total mass of the copper sulfate and the lauryl sodium sulfate, ultrasonically dispersing for 60min, concentrating under reduced pressure, and drying to obtain the copper sulfate/lauryl sodium sulfate composite material;

a preparation method of an automotive interior sound-absorbing material comprises the following steps:

A. weighing raw materials according to 45 parts of polypropylene, 25 parts of ethylene-vinyl acetate copolymer, 5 parts of straw, 7 parts of borax, 2 parts of titanium dioxide, 0.7 part of isoascorbic acid, 3 parts of modified mixed solution, 3 parts of sodium hexafluoroaluminate, 2 parts of zinc stearate and 0.4 part of mildew preventive for later use;

B. adding acetone which is 20 times of the modified mixed solution in mass into the modified mixed solution weighed in the step A, and performing ultrasonic dispersion for 25min to obtain modified mixed solution diluent;

C. mixing the straws weighed in the step A, borax and titanium dioxide to obtain a mixed material A, adding water accounting for 30% of the mass of the mixed material A into the mixed material A, mixing and stirring, making into small balls with the diameter of about 20mm by a ball forming machine, putting into an oven for drying, sintering at 850 ℃ for 15min, and cooling to room temperature to obtain a sinter;

D. adding the sinter obtained in the step C into the modified mixed solution diluent obtained in the step B, reacting at 55 ℃ for 20min, cooling to room temperature, filtering, and drying filter residues to obtain a mixed material B;

E. and (3) placing the polypropylene, the ethylene-vinyl acetate copolymer, the isoascorbic acid, the sodium hexafluoroaluminate, the zinc stearate and the mildew preventive which are weighed in the step (A) into a mixer, primarily mixing for 8min, adding the mixed material B prepared in the step (D), mixing for 4min at the rotating speed of 1200r/min, extruding by a double-screw extruder, and granulating by a granulator to obtain the automotive interior sound-absorbing material.

The sound-absorbing materials obtained in examples 1 to 3 and comparative examples 1 to 3 were subjected to performance tests, and the test results are shown in table 1.

Table 1:

in Table 1, the horizontal burning velocity is tested with reference to the standard GB 8410-2006; the vertical burning speed is tested according to the standard GB 32086-2015; the limiting oxygen index is tested with reference to the standard GB/T5454-1997.

The experimental results in table 1 show that the sound absorption coefficient of the sound absorbing material (examples 1 to 3) provided by the present invention is high and can reach more than 0.8, and the flame retardant property is excellent, the horizontal burning speed and the vertical burning speed are both 0, and the limiting oxygen index can reach more than 30%, compared with comparative examples 1 to 3, the modified mixed diluent has obvious advantages, which indicates that the modified mixed diluent of the present invention has double effects on the flame retardant property and the sound absorbing property of the sound absorbing material, especially, the N, N' -tetramethylchloroformamidine hexafluorophosphate in the modified mixed diluent has an outstanding effect, and the presence of titanium dioxide in the sound absorbing material also has certain effects on the flame retardant grade and the sound absorption coefficient.

The test results of formaldehyde emission of the sound-absorbing materials obtained in examples 1 to 3 also showed that the sound-absorbing materials obtained in examples 1 to 3 all had a formaldehyde emission of 0.9mg/kg or less, and met the relevant standards.

The sound-absorbing materials prepared in example 2 and comparative example 4 were tested for their bacteriostatic and anti-mildew properties with reference to the GB/T24346-2009 standard, and the results are shown in Table 2.

Table 2:

the experiment result in table 2 shows that the sound-absorbing material obtained by the invention has excellent bacteriostatic and mildewproof effects, and the 6-caprolactone in the mildewproof agent has a remarkable promoting effect on improving the mildewproof and bacteriostatic effects of copper sulfate.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.