Odor-removing film-forming agent for automotive interior fabric and preparation method of odor-removing film-forming agent

Abstract

The invention discloses an odor-removing film-forming agent for an automotive trim fabric and a preparation method, and belongs to the technical field of post-treatment odor-removing materials.The preparation method comprises the steps that waterborne polyurethane, carboxylated nano-silica, polyvinyl alcohol and other film-forming materials are placed in a high-temperature and high-pressure reaction kettle to react, and finally the waterborne film-forming agent is synthesized; the waterborne polyurethane can form a continuous thin film on a base material (automotive interior fabric), and the polyvinyl alcohol can improve the binding strength between the thin film and fibers after film forming. The carboxylated nano silicon dioxide particles can react with waterborne polyurethane and polyvinyl alcohol under high-temperature and high-pressure conditions to form a network macromolecular structure, so that the softness of a material formed by the film-forming agent can be improved, the material can be dispersed in an aqueous solution, and gaps among fibers can be filled with the carboxylated nano silicon dioxide particles; and after the prepared film-forming agent is used for treating the automobile interior fabric, a soft and compact film can be formed on the surface of the automobile interior fabric, so that the purpose of preventing the peculiar smell of the automobile interior fabric from being emitted is achieved.

Description

Technical Field

[0001] This invention belongs to the field of post-treatment deodorizing materials technology, and particularly relates to an odor-removing film-forming agent for automotive interior fabrics and its preparation method. Background Technology

[0002] With the sustained and stable development of my country's economy, the public's demand for motorized travel is constantly increasing. By the end of 2024, the national car ownership reached 453 million vehicles. With technological advancements, improved living standards, and increased knowledge, people's awareness of environmental protection and health is also rising. In-car air quality is the first sensory impression people have upon entering a vehicle. Research shows that various odors can stimulate the human sense of smell and evoke emotions, thus influencing people's attitudes towards products to a certain extent.

[0003] The automotive industry occupies a vital position in my country's national economy, making significant contributions not only economically but also playing a crucial role in technological innovation and employment. In the future, with the development of new energy vehicles and continuous technological innovation, the automotive industry will continue to drive national economic development and technological progress. Therefore, implementing in-vehicle air pollution control and developing odor removal materials and technologies for automotive interior materials are undoubtedly of great significance for promoting the industrial upgrading of my country's automotive industry and protecting consumer health.

[0004] Currently, in-vehicle pollution control technologies mainly involve using zero-emission materials at the source, diluting odors with good ventilation and air exchange technology in the middle stage, and effectively adsorbing or degrading odors at the end stage. However, due to the special nature of automotive interior materials, baking techniques are commonly used to reduce odor levels by heating the interior fabrics to accelerate odor dissipation. This method, however, causes severe air pollution and is energy-intensive. Researchers have explored increasing temperature and pressure during material post-processing to promote VOC emissions from raw materials and adding vacuum devolatilization devices to extruders during material processing to remove small volatile molecules and reduce VOC release during use. Furthermore, some researchers have used devolatilization technology to heat polymer materials used in interior trim, causing catalysts, residual reactants, monomers, solvents, and other intercalations in the polymer to volatilize or degrade, effectively reducing the VOC content and odor of polymer interior trim. Ren et al. (Ren Chonglei et al., The Influence of Exhaust Ventilation Baking Post-Treatment Process on VOC Performance and Odor of Automotive Soft Interior Parts, Automotive Technology and Materials, 2017.9.20) used an exhaust ventilation baking process to reduce the volatile organic compound content of automotive interior parts in order to solve the problem of high VOC content and odor in automotive interior parts. The results showed that this process can significantly reduce the VOC content of automotive carpets and linings. However, the above method causes serious air pollution and has high energy consumption. As for end-of-pipe purification technology, activated carbon adsorption is a commonly used technology, but it can only physically adsorb low concentrations of gases and is easily saturated. Moreover, this method usually only treats the symptoms and not the root cause. Some researchers have used photocatalysis technology to purify the odor of automotive interior materials. However, photocatalysis technology only shows excellent photodegradation performance when the pollutant concentration is high, and the catalyst has poor adhesion to the interior materials, resulting in a hard feel and poor performance. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes an odor-removing film-forming agent for automotive interior fabrics and its preparation method.

[0006] To achieve the above objectives, the present invention provides a method for preparing an odor-removing film-forming agent for automotive interior fabrics, comprising the following steps: mixing waterborne polyurethane, carboxylated nano-silica and polyvinyl alcohol in water, and obtaining the odor-removing film-forming agent for automotive interior fabrics after a hydrothermal reaction.

[0007] This invention synthesizes an aqueous film-forming agent by reacting film-forming materials such as waterborne polyurethane, carboxylated nano-silica, and polyvinyl alcohol in a high-temperature and high-pressure reactor. The waterborne polyurethane can form a continuous film on a substrate (mainly automotive interior fabric in this invention). Polyvinyl alcohol can improve the bonding strength between the film and the fibers after film formation. The carboxylated nano-silica particles can react with waterborne polyurethane and polyvinyl alcohol under high temperature and high pressure to form a network macromolecular structure, which can improve the softness of the film-forming material after film formation and disperse it in the aqueous solution. Moreover, the carboxylated nano-silica particles can fill the gaps between fibers, further preventing the emission of odors. After treating automotive interior fabric with the prepared film-forming agent, a soft and dense film can be formed on its surface, thereby achieving the purpose of preventing the emission of odors from automotive interior fabric.

[0008] In an embodiment of the present invention, the mass ratio of waterborne polyurethane, carboxylated nano-silica, and polyvinyl alcohol is (30.0-40.0):(3.0-5.0):(10.0-15.0).

[0009] In embodiments of the present invention, the average size of carboxylated nano-silica is 100-200 nm.

[0010] In the embodiments of the present invention, the number average molecular weight of polyvinyl alcohol is 16,000-20,000.

[0011] In an embodiment of the present invention, the hydrothermal reaction temperature is 140-180°C and the time is 12-24 hours.

[0012] In an embodiment of the present invention, the solid content of the odor-removing film-forming agent for automotive interior fabrics is 45-65%.

[0013] The present invention also provides an odor-removing film-forming agent for automotive interior fabrics prepared according to the above method.

[0014] The present invention also provides an application of the above-mentioned automotive interior fabric odor-removing film-forming agent in removing odors from automotive interior fabrics.

[0015] The present invention also provides a method for removing odors from automotive interior fabrics, using the aforementioned automotive interior fabric odor removal film-forming agent, the specific steps of which are as follows: immersing the automotive interior fabric in the aforementioned automotive interior fabric odor removal film-forming agent, followed by pre-drying and baking.

[0016] In an embodiment of the present invention, in the above method for removing odor from automotive interior fabrics, the soaking time is 1-30 min, the bath ratio is 1 g:(5-100) mL; the liquid retention rate of the automotive interior fabric after soaking is 20%-150%, the pre-drying temperature is 40-90℃, the pre-drying time is 3-5 min, the baking temperature is 90-200℃, and the baking time is 90-300 s.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] This invention utilizes waterborne polyurethane, carboxylated nano-silica, and polyvinyl alcohol as film-forming materials to prepare an aqueous film-forming agent in a high-temperature, high-pressure reactor. This agent can form a soft, dense film on the fiber surface, reducing or even preventing the emission of odors from automotive interior fabrics, thus achieving the goal of creating a healthy automotive cabin. Compared with traditional odor removal processes, this invention reduces energy consumption and air pollution, and improves the odor compliance rate of automotive interior materials. Detailed Implementation

[0019] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as any other stated value or each smaller range between intermediate values ​​within a range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials are described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention. All references to literature in this specification are incorporated by way of citation to disclose and describe the methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0022] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0023] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0024] This invention provides a method for preparing an odor-removing film-forming agent for automotive interior fabrics, comprising the following steps: mixing waterborne polyurethane, carboxylated nano-silica, and polyvinyl alcohol in water, and obtaining the odor-removing film-forming agent for automotive interior fabrics after a hydrothermal reaction.

[0025] This invention synthesizes an aqueous film-forming agent by reacting film-forming materials such as waterborne polyurethane, carboxylated nano-silica, and polyvinyl alcohol in a high-temperature and high-pressure reactor. The waterborne polyurethane can form a continuous film on the substrate (automotive interior fabric), the polyvinyl alcohol can improve the bonding strength between the film and the fiber after film formation, and the carboxylated nano-silica particles can react with waterborne polyurethane and polyvinyl alcohol under high temperature and high pressure to form a network macromolecular structure, which can improve the softness of the film-forming material after film formation and disperse it in the aqueous solution. Moreover, the carboxylated nano-silica can fill the gaps between fibers, further preventing the emission of odors. After treating the automotive interior fabric with the prepared film-forming agent, a soft and dense film can be formed on its surface, thereby achieving the purpose of preventing the emission of odors from the automotive interior fabric.

[0026] In an embodiment of the present invention, the mass ratio of waterborne polyurethane, carboxylated nano-silica, and polyvinyl alcohol is (30.0-40.0):(3.0-5.0):(10.0-15.0).

[0027] In embodiments of the present invention, the average size of carboxylated nano-silica is 100-200 nm. When the average size of carboxylated nano-silica is less than 100 nm, on the one hand, its production cost increases significantly, and on the other hand, the nanoparticles that are too small cannot fully fill the gaps between fibers, resulting in insufficient odor dissipation from the fibers. When the average size of carboxylated nano-silica is greater than 200 nm, the nanoparticles that are too large cannot fill the gaps between fibers.

[0028] In the embodiments of the present invention, the number average molecular weight of polyvinyl alcohol is 16,000-20,000. A high number average molecular weight of polyvinyl alcohol will result in a harder film formed on the fiber surface after the reaction, affecting the feel; a low number average molecular weight will result in a weaker interaction between the fiber and the film after the reaction, affecting the film's strength and reducing its performance.

[0029] In embodiments of the present invention, the hydrothermal reaction temperature is 140-180°C, and the time is 12-24 hours. Too low a reaction temperature will prevent the reaction from proceeding and the formation of a robust network macromolecular structure will not occur. Too high a temperature will cause the carboxylated nano-silica to agglomerate rapidly, failing to achieve the desired effect of the present invention. Too short a reaction time will result in incomplete reaction, increasing usage costs, while too long a reaction time will reduce production efficiency.

[0030] In an embodiment of the present invention, the solid content of the odor-removing film-forming agent for automotive interior fabrics is 45-65%.

[0031] The present invention also provides an odor-removing film-forming agent for automotive interior fabrics prepared according to the above method.

[0032] The present invention also provides an application of the above-mentioned automotive interior fabric odor-removing film-forming agent in removing odors from automotive interior fabrics.

[0033] The present invention also provides a method for removing odors from automotive interior fabrics, using the aforementioned automotive interior fabric odor removal film-forming agent, the specific steps of which are as follows: immersing the automotive interior fabric in the aforementioned automotive interior fabric odor removal film-forming agent, followed by pre-drying and baking.

[0034] In an embodiment of the present invention, in the above method for removing odor from automotive interior fabrics, the soaking time is 1-30 min, the bath ratio is 1 g:(5-100) mL; the liquid retention rate of the automotive interior fabric after soaking is 20%-150%, the pre-drying temperature is 40-90℃, the pre-drying time is 3-5 min, the baking temperature is 90-200℃, and the baking time is 90-300 s.

[0035] In an embodiment of the present invention, the automotive interior fabric is kept at a liquid content of 20%-150% by rolling.

[0036] Unless otherwise specified, the room temperature in this invention is 25±2℃.

[0037] All raw materials used in the embodiments of this invention were purchased commercially. For example, the waterborne polyurethane (model FS-1556) was purchased from Anhui Feimiao Chemical Co., Ltd.; the carboxylated nano-silica was purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd. (model 103761), and the carboxylated nano-silica powder was prepared into a 1 mg / L aqueous suspension for use; the nano-silica was purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd. (model 103577), and the nano-silica powder was prepared into a 1 mg / L aqueous suspension for use.

[0038] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0039] The technical solution of the present invention will be further illustrated by the following embodiments.

[0040] Example 1

[0041] 30.0g of waterborne polyurethane, 5.0g of carboxylated nano-silica (average size 100-200nm) and 15.0g of polyvinyl alcohol (number average molecular weight 18000) were placed in a high temperature and high pressure reactor, and then 50mL of distilled water was added. After sealing, the mixture was reacted at 150℃ for 20 hours to obtain an odor removal film-forming agent for automotive interior fabrics with a solid content of 50%.

[0042] Subsequently, the automotive interior fabric was immersed in a film-forming agent with a solid content of 50% for 10 minutes at a liquor ratio of 1:20 (g / mL). Then, a rolling mill was used to maintain a liquid content of 40% in the automotive interior fabric. Finally, it was pre-dried at 50℃ for 5 minutes and baked at 170℃ for 120 seconds to obtain a low-odor automotive interior fabric. The odor levels of the automotive interior fabric (original sample) and the low-odor automotive interior fabric (after treatment) under dry conditions were evaluated according to the SAIC Passenger Car Interior Parts and Materials Odor Test Method Standard (SMC 30156-2007 "Odor Test of Passenger Car Interior Materials"). The results are shown in Table 1.

[0043] Table 1. Odor levels of automotive interior fabrics before and after treatment with the film-forming agent of Example 1.

[0044] sample Test temperature Limit Results Details Scent Officer 1 Scent Agent 2 Scent Officer 3 Scent Officer 4 Scent Officer 5 Pass / Fail Original sample 80℃ ≤3.0 grade 3.5+ 4.0 3.5+ 3.5 4.0 Unqualified After processing 80℃ ≤3.0 grade 2.5 2.5+ 2.5 2.5 2.5+ qualified

[0045] Note: In Table 1, "+" indicates that the odor rating exceeds the current value but has not reached the next level. For example, 3.5+ means that the odor rating is greater than 3.5 but has not reached 4.0.

[0046] As can be seen from Table 1, the original sample had an odor level >3.5, which did not meet the qualified level; after treatment with the automotive interior fabric odor removal film-forming agent of this embodiment, the odor level of the automotive interior fabric reached 2.5-3, indicating that the automotive interior fabric odor removal film-forming agent synthesized in this invention has a significant effect on removing automotive interior odors.

[0047] Example 2

[0048] 40.0g of waterborne polyurethane, 3.0g of carboxylated nano-silica (average size 100-200nm) and 10.0g of polyvinyl alcohol (number average molecular weight 20000) were placed in a high-temperature and high-pressure reactor, and then 50mL of distilled water was added. After sealing, the mixture was reacted at 180℃ for 12 hours to obtain an odor-removing film-forming agent for automotive interior fabrics with a solid content of 51.5%.

[0049] Subsequently, the automotive interior fabric was immersed in the aforementioned automotive interior fabric odor removal film-forming agent with a solid content of 51.5% for 20 minutes at a liquor ratio of 1:50 (g / mL). Then, the automotive interior fabric was rolled to maintain an 80% liquid content. Finally, it was pre-dried at 70°C for 5 minutes and baked at 200°C for 90 seconds to obtain a low-odor automotive interior fabric. The odor levels of the automotive interior fabric (original sample) under dry conditions and the low-odor automotive interior fabric (after treatment) were evaluated (the testing standards were the same as in Example 1). The results are shown in Table 2.

[0050] Table 2 Odor ratings of automotive interior fabrics before and after treatment with the film-forming agent of Example 2.

[0051]

[0052]

[0053] Example 3

[0054] 35.0g of waterborne polyurethane, 4.0g of carboxylated nano-silica (average size 100-200nm) and 12.0g of polyvinyl alcohol (number average molecular weight 16000) were placed in a high temperature and high pressure reactor, and then 60mL of distilled water was added. After sealing, the mixture was reacted at 140℃ for 24 hours to obtain an odor removal film-forming agent for automotive interior fabrics with a solid content of 46%.

[0055] Subsequently, the automotive interior fabric was immersed in the aforementioned automotive interior fabric odor removal film-forming agent with a solid content of 46% for 30 minutes at a liquor ratio of 1:100 (g / mL). Then, the automotive interior fabric was rolled to maintain a liquid content of 150%. Finally, it was pre-dried at 90°C for 3 minutes and baked at 180°C for 150 seconds to obtain a low-odor automotive interior fabric. The odor levels of the automotive interior fabric (original sample) under dry conditions and the low-odor automotive interior fabric (after treatment) were evaluated (the testing standards were the same as in Example 1). The results are shown in Table 3.

[0056] Table 3 Odor levels of automotive interior fabrics before and after treatment with the film-forming agent of Example 3.

[0057] sample Test temperature Limit Results Details Scent Officer 1 Scent Agent 2 Scent Officer 3 Scent Officer 4 Scent Officer 5 Pass / Fail Original sample 80℃ ≤3.0 grade 3.5+ 4.0 3.5+ 3.5 4.0 Unqualified After processing 80℃ ≤3.0 grade 3.0 3.0+ 2.5+ 3.0 2.5+ qualified

[0058] Example 4

[0059] 32.0g of waterborne polyurethane, 4.0g of carboxylated nano-silica (average size 100-200nm) and 10.0g of polyvinyl alcohol (number average molecular weight 18000) were placed in a high-temperature and high-pressure reactor, and then 30mL of distilled water was added. After sealing, the mixture was reacted at 160℃ for 18 hours to obtain an odor-removing film-forming agent for automotive interior fabrics with a solid content of 60.5%.

[0060] Subsequently, the automotive interior fabric was immersed in the aforementioned automotive interior fabric odor removal film-forming agent with a solid content of 60.5% for 1 minute at a liquor ratio of 1:5 (g / mL). Then, the automotive interior fabric was rolled to maintain a liquid content of 130%. Finally, it was pre-dried at 40°C for 5 minutes and baked at 90°C for 300 seconds to obtain a low-odor automotive interior fabric. The odor levels of the automotive interior fabric (original sample) under dry conditions and the low-odor automotive interior fabric (after treatment) were evaluated (the testing standards were the same as in Example 1). The results are shown in Table 4.

[0061] Table 4 Odor levels of automotive interior fabrics before and after treatment with the film-forming agent of Example 4.

[0062] sample Test temperature Limit Results Details Scent Officer 1 Scent Agent 2 Scent Officer 3 Scent Officer 4 Scent Officer 5 Pass / Fail Original sample 80℃ ≤3.0 grade 3.5+ 4.0 3.5+ 3.5 4.0 Unqualified After processing 80℃ ≤3.0 grade 2.5+ 3.0+ 2.5+ 3.0 3.0 qualified

[0063] Comparative Example 1

[0064] 35.0g of waterborne polyurethane and 15.0g of polyvinyl alcohol (number average molecular weight of 18000) were placed in a high-temperature and high-pressure reactor, and then 50mL of distilled water was added. After sealing, the mixture was reacted at 150℃ for 20 hours to obtain a film-forming agent with a solid content of 50%.

[0065] Subsequently, the automotive interior fabric was immersed in the aforementioned film-forming agent with a solid content of 50% for 10 minutes at a liquor ratio of 1:20 (g / mL). Then, a rolling mill was used to maintain a liquid content of 40% in the fabric. Finally, it was pre-dried at 50°C for 5 minutes and baked at 170°C for 120 seconds to obtain a low-odor automotive interior fabric. The odor levels of the dry automotive interior fabric (original sample) and the low-odor automotive interior fabric (after treatment) were evaluated (the testing standards were the same as in Example 1). The results are shown in Table 5.

[0066] Table 5. Odor ratings of automotive interior fabrics before and after treatment with the film-forming agent prepared in Comparative Example 1.

[0067] sample Test temperature Limit Results Details Scent Officer 1 Scent Agent 2 Scent Officer 3 Scent Officer 4 Scent Officer 5 Pass / Fail Original sample 80℃ ≤3.0 grade 3.5+ 4.0 3.5+ 3.5 4.0 Unqualified After processing 80℃ ≤3.0 grade 3.5 3 3.5 3.5 3.5 Unqualified

[0068] As shown in Table 5, the original sample had an odor level >3.5, failing to meet the acceptable level. After treatment with the film-forming agent prepared in Comparative Example 1, the odor level of the automotive interior fabric reached 3.5, also failing to meet the acceptable level. This indicates that the film-forming agent synthesized in this comparative example has almost no effect on removing odors from automotive interiors. This is because carboxymethylated nano-silica has continuous film-forming properties and small particle size, which can fill the gaps on the fiber surface, preventing the fabric odor from effectively dissipating and achieving the purpose of odor removal.

[0069] Comparative Example 2

[0070] 5.0g of carboxylated nano-silica (average size 100-200nm) and 15.0g of polyvinyl alcohol (number average molecular weight 18000) were placed in a high-temperature and high-pressure reactor, and then 80ml of distilled water was added. After sealing, the mixture was reacted at 150℃ for 20 hours to obtain a film-forming agent with a solid content of 20%.

[0071] The automotive interior fabric was then immersed in a film-forming agent with a solid content of 20% for 10 minutes at a liquor ratio of 1:20 (g / mL). The fabric was then rolled to maintain a liquid hold of 40%. Finally, it was pre-dried at 50°C for 5 minutes and then baked at 170°C for 120 seconds to obtain a low-odor automotive interior fabric. The odor levels of the dry automotive interior fabric (original sample) and the low-odor automotive interior fabric (after treatment) were evaluated (the testing standards were the same as in Example 1). The results are shown in Table 6.

[0072] Table 6. Odor ratings of automotive interior fabrics before and after treatment with the film-forming agent prepared in Comparative Example 2.

[0073] sample Test temperature Limit Results Details Scent Officer 1 Scent Agent 2 Scent Officer 3 Scent Officer 4 Scent Officer 5 Pass / Fail Original sample 80℃ ≤3.0 grade 3.5+ 4.0 3.5+ 3.5 4.0 Unqualified After processing 80℃ ≤3.0 grade 3.5+ 3.5+ 3.5 3.5 4.0 Unqualified

[0074] As shown in Table 6, the original sample had an odor level >3.5, failing to meet the acceptable level. After treatment with the film-forming agent in this comparison, the odor level of the automotive interior fabric was ≥3.5, also failing to meet the acceptable level. This indicates that the film-forming agent synthesized in this comparative example has almost no effect on removing odors from automotive interiors. This is mainly because the film-forming agent prepared without the addition of water-based polyurethane has poor film-forming effect and cannot form a network structure. It dissolves in water and cannot form a film, let alone form a continuous film on the fabric surface, resulting in a high odor level for the treated automotive interior fabric, failing to meet the acceptable level.

[0075] Comparative Example 3

[0076] 40.0g of waterborne polyurethane and 5.0g of carboxylated nano-silica (average size 100-200nm) were placed in a high-temperature and high-pressure reactor, and then 55mL of distilled water was added. After sealing, the mixture was reacted at 150℃ for 20 hours to obtain a film-forming agent with a solid content of 45%.

[0077] The automotive interior fabric was then immersed in a film-forming agent with a solid content of 45% for 10 minutes at a liquor ratio of 1:20 (g / mL). The fabric was then rolled to maintain a liquid hold of 40%. Finally, it was pre-dried at 50°C for 5 minutes and then baked at 170°C for 120 seconds to obtain a low-odor automotive interior fabric. The odor levels of the dry automotive interior fabric (original sample) and the low-odor automotive interior fabric (treated) were evaluated (the testing standards were the same as in Example 1). The results are shown in Table 7.

[0078] Table 7 Odor ratings of automotive interior fabrics before and after treatment with the film-forming agent prepared in Comparative Example 3.

[0079] sample Test temperature Limit Results Details Scent Officer 1 Scent Agent 2 Scent Officer 3 Scent Officer 4 Scent Officer 5 Pass / Fail As is 80℃ ≤3.0 grade 3.5+ 4.0 3.5+ 3.5 4.0 Unqualified After processing 80℃ ≤3.0 grade 3.5 3.5 3.0 3.0 3.5 Unqualified

[0080] As shown in Table 7, the original sample had an odor level >3.5, failing to meet the acceptable level. After treatment with the film-forming agent of this comparative example, the odor level of the automotive interior fabric was ≥3.0, also failing to meet the acceptable level. This indicates that the film-forming agent synthesized in this comparative example did not have a significant removal effect on automotive interior odors. This is mainly because the film-forming agent without added polyvinyl alcohol (number average molecular weight of 18000) had a slightly poorer film-forming effect, resulting in a higher odor level for the treated automotive interior fabric, which failed to meet the acceptable level.

[0081] Comparative Example 4

[0082] Same as Example 1, except that the carboxylated nano-silica was replaced with nano-silica (average size 100-200nm).

[0083] The odor levels of automotive interior fabrics under dry conditions (original sample) and low-odor automotive interior fabrics (after treatment) were evaluated (the testing standards were the same as in Example 1), and the results are shown in Table 8.

[0084] Table 8 Odor levels of automotive interior fabrics before and after treatment with the film-forming agent of Comparative Example 4

[0085] sample Test temperature Limit Results Details Scent Officer 1 Scent Agent 2 Scent Officer 3 Scent Officer 4 Scent Officer 5 Pass / Fail Original sample 80℃ ≤3.0 grade 3.5+ 4.0 3.5+ 3.5 4.0 Unqualified After processing 80℃ ≤3.0 grade 3.5 3.5+ 3.5 3.5 3.5 Unqualified

[0086] As described above, this invention synthesizes an aqueous film-forming agent by reacting film-forming materials such as waterborne polyurethane, carboxylated nano-silica, and polyvinyl alcohol in a high-temperature, high-pressure reactor. The waterborne polyurethane forms a continuous film on the substrate (automotive interior fabric), while polyvinyl alcohol improves the bonding strength between the film and fibers after film formation. The carboxylated nano-silica particles react with the waterborne polyurethane and polyvinyl alcohol under high temperature and pressure to form a network macromolecular structure, enhancing the softness of the film-forming material and dispersing it in the aqueous solution. Furthermore, the carboxylated nano-silica particles fill the gaps between fibers, further preventing odor emission. When automotive interior fabrics are treated with the odor-removing film-forming agent prepared using this invention, a soft and dense film forms on their surface, thereby preventing the emission of odors from the automotive interior fabrics. The odor level of the fabric under dry conditions was evaluated according to the SAIC Motor interior parts and materials odor test method standard. The results showed that after the automotive interior fabric was treated with the film-forming agent prepared in each embodiment, its odor level reached 2.5-3, indicating that the film-forming agent prepared in this invention has a significant effect on removing odor from automotive interior fabric.

[0087] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing an odor-removing film-forming agent for automotive interior fabrics, characterized in that, Includes the following steps: A film-forming agent for removing odors from automotive interior fabrics is obtained by mixing waterborne polyurethane, carboxylated nano-silica, and polyvinyl alcohol in water and reacting them hydrothermally.

2. The preparation method of the odor-removing film-forming agent for automotive interior fabrics according to claim 1, characterized in that, The mass ratio of waterborne polyurethane, carboxylated nano-silica, and polyvinyl alcohol is (30.0-40.0):(3.0-5.0):(10.0-15.0).

3. The method for preparing the odor-removing film-forming agent for automotive interior fabrics according to claim 2, characterized in that, The average size of carboxylated nano-silica is 100-200 nm.

4. The preparation method of the odor-removing film-forming agent for automotive interior fabrics according to claim 2, characterized in that, The number average molecular weight of polyvinyl alcohol is 16,000-20,000.

5. The method for preparing the odor-removing film-forming agent for automotive interior fabrics according to claim 1, characterized in that, The hydrothermal reaction takes place at a temperature of 140-180℃ for 12-24 hours.

6. The method for preparing the odor-removing film-forming agent for automotive interior fabrics according to claim 1, characterized in that, The solid content of the odor-removing film-forming agent for automotive interior fabrics is 45-65%.

7. A film-forming agent for removing odors from automotive interior fabrics, characterized in that, It is prepared according to the preparation method of any one of claims 1-6.

8. The application of the automotive interior fabric odor-removing film-forming agent as described in claim 7 in removing odors from automotive interior fabrics.

9. A method for removing odors from automotive interior fabrics, characterized in that, The specific steps for using the odor-removing film-forming agent for automotive interior fabrics according to claim 7 are as follows: Immerse the automotive interior fabric in the odor-removing film-forming agent for automotive interior fabrics according to claim 7, and then pre-dry and bake it.

10. The method for removing odors from automotive interior fabrics according to claim 9, characterized in that, Soaking time is 1-30 min, bath ratio is 1 g: (5-100) mL; after soaking, the liquid retention rate of automotive interior fabric is 20%-150%, pre-drying temperature is 40-90℃, pre-drying time is 3-5 min, baking temperature is 90-200℃, baking time is 90-300 s.

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