POE elastomer interior trim skin and preparation method thereof

Abstract

The invention relates to a POE elastomer interior trim skin and a preparation method thereof.The POE elastomer interior trim skin comprises an elastomer skin body, a bottom layer and a waterproof coating, the bottom layer is formed by attaching chlorinated polyolefin to the surface of the elastomer skin body, and the waterproof coating is formed by coating the surface of the bottom layer with waterproof paint; the hydrophobic coating is prepared from the following components in percentage by mass: 5 to 10 weight percent of nano silicon dioxide, 5 to 10 weight percent of organic silicon wear-resistant additive, 0 to 5 weight percent of perfluoroalkyl compound, 5 to 15 weight percent of carbodiimide cross-linking agent, 6 to 8 weight percent of modified composite starch and the balance of silicone resin, the modified composite starch comprises composite starch and esterified starch, and the raw materials of the composite starch comprise starch, sodium chlorate, sodium hydroxide and dodecenyl succinic anhydride. The water resistance of the POE elastomer interior trim skin can be remarkably improved, meanwhile, component analysis is inhibited, and the anti-aging stability is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of elastomers, in particular to a POE elastomer interior skin and a preparation method thereof. BACKGROUND

[0002] At present, the interior skin of a vehicle is usually prepared by using an elastomer such as PVC, PU or general TPU. Due to the molecular structure characteristics, such materials usually have excellent elasticity and recovery, and can quickly restore to the original state after deformation, thereby providing comfortable support and touch for interior parts such as seats, armrests and door panels.

[0003] However, the interior skin materials in the prior art each have its own inherent drawbacks. First, the widely used PVC skin has the risk of plasticizer migration and precipitation, which not only affects the touch, but also may harm human health and the environment. Second, the polyurethane (PU) or thermoplastic polyurethane (TPU) skin has polar ester bonds or urethane bonds in the molecular structure, which are easy to react with water molecules, resulting in water absorption of the material. When in a humid environment for a long time, water penetration will cause hydrolytic degradation of the material, resulting in problems such as insufficient aging resistance, mechanical property decline, surface powdering and cracking, which seriously affect the service life and appearance. SUMMARY

[0004] In order to improve the water resistance of the POE elastomer interior skin, the present application provides a POE elastomer interior skin and a preparation method thereof.

[0005] In a first aspect, the present application provides a POE elastomer interior skin, which adopts the following technical solution: A POE elastomer interior skin, comprising an elastomer skin body, a bottom layer and a waterproof coating, the bottom layer being formed by attaching a chlorinated polyolefin on the surface of the elastomer skin body, and the waterproof coating being formed by coating waterproof paint on the surface of the bottom layer; according to mass percentage, the waterproof paint comprises the following components: 5-10wt% of nano-silicon dioxide, 5-10wt% of silicone wear-resistant additive, 0-5wt% of perfluoroalkyl compound, 5-15wt% of carbodiimide crosslinking agent, 6-8wt% of modified composite starch, and the balance being silicone resin; The modified composite starch comprises composite starch and esterified starch, and the composite starch raw material comprises starch, sodium chlorate, sodium hydroxide and dodecenyl succinic anhydride.

[0006] By adopting the technical scheme, the bottom layer and the waterproof coating are coated on the surface of the elastomer skin body, the bottom layer is chlorinated polyolefin, has good adhesion, can make the waterproof coating and the elastomer skin body combine more stably, thereby further reducing the phenomenon of moisture erosion of the elastomer surface, the waterproof coating is added with nano silicon dioxide and silicone wear-resistant additives, so that the waterproof coating has good hydrophobic property, and composite starch is also added, the composite starch is modified by sodium chlorite and dodecenyl succinic anhydride, the starch treated by dodecenyl succinic anhydride has good hydrophobicity, and carboxymethyl is introduced by sodium chloroacetate, so that the prepared composite starch has better dispersity and compatibility, so that the prepared modified composite starch is uniformly dispersed in the system and can effectively play a hydrophobic role.

[0007] Preferably, the composite starch is prepared by the following method: The starch is mixed and activated with a sodium silicate solution, dodecenyl succinic anhydride is added and stirred uniformly, then a sodium silicate solution is added, stirred and then left to stand, heated and reacted, dried to obtain a pre-starch, ethanol, water and the pre-starch are mixed and stirred, sodium chloroacetate is added, stirred, then sodium hydroxide is added, condensed and refluxed, heated and reacted, cooled, filtered and washed, and dried to obtain the composite starch.

[0008] By adopting the technical scheme, the starch is modified by dodecenyl succinic anhydride to obtain pre-starch with good hydrophobic property, and sodium chloroacetate is combined to make the prepared composite starch have good dispersity and compatibility, so as to reduce the aggregation of the starch in the system and make the prepared composite starch have good stability.

[0009] Preferably, the mass ratio between the starch and dodecenyl succinic anhydride is 1:(0.2-0.3).

[0010] Preferably, the mass ratio between the starch and dodecenyl succinic anhydride is within the above range, which can further improve the stability of the prepared composite starch as a whole.

[0011] Preferably, the mass ratio between the pre-starch, sodium chloroacetate and sodium hydroxide is 5.4:(2.2-2.6):1.

[0012] By adopting the technical scheme, the mass ratio between the pre-starch, sodium chloroacetate and sodium hydroxide is preferably within the above range, which can effectively improve the stability of the prepared composite starch.

[0013] Preferably, the esterified starch raw material includes ethylenediaminetetraacetic dianhydride and starch.

[0014] By adopting the technical scheme, the ethylenediaminetetraacetic dianhydride is combined with the starch, and then esterification is performed, so that the starch has good combination performance, and the overall adsorption effect of the starch can be effectively improved. After being combined with the composite starch, the esterified starch has uniform surface adhesion capacity, so that the starch can be fully combined with the base material and uniformly covered.

[0015] Preferably, the esterified starch is prepared by the following method: The acetic anhydride is mixed with anhydrous pyridine, and then the ethylenediaminetetraacetic acid is added. After being heated and stirred, the reaction is cooled, filtered, washed and dried to obtain the ethylenediaminetetraacetic dianhydride. The N,N-dimethylformamide, the starch and the ethylenediaminetetraacetic dianhydride are mixed, and then the reaction is heated. After being centrifuged, washed and dried, the esterified starch is obtained.

[0016] By adopting the technical scheme, the ethylenediaminetetraacetic dianhydride is a chelating agent with good biodegradability and good activity. The acid anhydride in the ethylenediaminetetraacetic dianhydride reacts with the hydroxyl group in the starch to modify the properties of the starch, so that the starch can be more uniformly distributed in the coating system, thereby improving the overall stability of the system.

[0017] Preferably, the mass ratio between the ethylenediaminetetraacetic dianhydride and the starch is 1:(2.4-2.8).

[0018] By adopting the technical scheme, the mass ratio between the ethylenediaminetetraacetic dianhydride and the starch is preferably within the above range, which effectively reduces the steric hindrance of the starch, improves the esterification degree of the starch, and effectively improves the overall stability of the prepared esterified starch.

[0019] Preferably, the reaction time between the starch and the ethylenediaminetetraacetic dianhydride is 18-22h.

[0020] By adopting the technical scheme, the reaction time is preferably within the above range, which can make the starch and the ethylenediaminetetraacetic dianhydride fully react, and the prepared esterified starch has good stability.

[0021] Preferably, the mass ratio between the composite starch and the esterified starch is 1:(0.6-0.8).

[0022] By adopting the technical scheme, the mass ratio between the composite starch and the esterified starch is preferably within the above range, so that the composite starch and the esterified starch can synergistically improve the overall surface activity of the starch composite after being compounded, so that the starch composite has good adhesion performance.

[0023] Preferably, the elastomer skin body is prepared from a thermoplastic polyolefin elastomer mixture comprising ethylene-octene copolymer, ethylene-propylene-diene rubber, dibromoneopentyl glycol, and a dynamic crosslinking agent.

[0024] By using the above technical solution, the long-chain structure of the ethylene-octene copolymer endows the system with good flexibility and low-temperature impact resistance, the ethylene-propylene-diene rubber forms an elastomer composite dispersed phase, and the dibromoneopentyl glycol, as a reactive flame retardant, is bonded to the polymer network during processing, thereby endowing the skin body with long-lasting, efficient, and less-migrating flame-retardant properties.

[0025] In a second aspect, the application provides a method for preparing a POE elastomer interior skin, which uses the following technical solution: using extrusion composite molding, the elastomer is blended and vulcanized to form an extruded film in an extruder, and the film is compounded with the base fabric online; Dynamic vulcanization treatment: a crosslinking agent is added during extrusion to control the crosslinking degree at 5%-10%; The elastomer skin body raw materials are added to the extruder for blending, and at the same time, the vulcanization reaction is completed in the extruder to form an elastomer film material. After extrusion, the film material is bonded with the unwound base fabric to form a composite blank, which is the elastomer skin body; The TPO surface layer in the composite blank is modified by ionized gas; A printing process is used to coat chlorinated polyolefin on the surface-treated TPO surface layer, and after curing, a bottom coating layer is obtained. Then, a waterproof coating is coated on the surface of the bottom coating layer, and after drying, a surface coating layer is formed, and a blank is obtained; The coated blank is embossed, and after cooling and setting, a semi-finished product with three-dimensional texture is obtained; Through electron irradiation crosslinking technology, crosslinking is carried out to improve the temperature resistance and pattern retention of the POE elastomer interior skin.

[0026] In summary, the application has at least one of the following beneficial technical effects: 1. A bottom layer and a waterproof coating are coated on the surface of the elastomer skin body. The bottom layer is chlorinated polyolefin, which has good adhesion and can make the waterproof coating and the elastomer skin body more stable, thereby further reducing the occurrence of moisture erosion on the surface of the elastomer. Nano-silicon dioxide and organic silicon wear-resistant additives are added to the waterproof coating to make the waterproof coating have good hydrophobicity. Composite starch is also added, which is modified by sodium chlorite and dodecenyl succinic anhydride. The starch treated by dodecenyl succinic anhydride has good hydrophobicity, and then sodium chloroacetate is combined to introduce carboxymethyl, so that the prepared composite starch has better dispersity and compatibility, so that the modified composite starch uniformly disperses in the system and effectively plays a hydrophobic role. 2. Dodecenyl succinic anhydride was used to modify starch to obtain pre-made starch with good hydrophobic properties. Then, sodium monochloroacetate was used to bind it, so that the prepared composite starch has good dispersibility and compatibility, thereby reducing the phenomenon of starch agglomeration in the system and making the prepared composite starch have good stability. 3. Ethylenediaminetetraacetic dianhydride is a chelating agent with good biodegradability and activity. The anhydride in ethylenediaminetetraacetic dianhydride undergoes esterification with the hydroxyl groups in starch, thereby modifying the properties of starch and enabling it to be more evenly distributed in the coating system. This improves the overall stability of the system and provides good hydrophobic and dispersing properties, thus further protecting the elastic interior trim. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the embodiments: Raw material description: All raw materials in the examples are commercially available; among them, the organosilicon wear-resistant additive is polydimethylsiloxane (CAS No.: 9016-00-6).

[0028] Example 1 Preparation of compound starch: Mix 25g of starch (CAS No.: 9005-25-8) with 50g of sodium silicate solution, then pulverize and stir evenly in a grinder. Activate under sealed conditions for 60 minutes. Add 5g of dodecenylsuccinic anhydride (CAS No.: 25377-73-5), stir evenly, then add 10g of sodium silicate solution. Stir and allow to stand at 25°C for 3 hours under sealed conditions. Increase the temperature to 55°C and react for 180 minutes. Cool to 25°C and dry. To obtain pre-prepared starch, 50g of ethanol, 100g of deionized water, and 12.59g of pre-prepared starch were mixed and stirred at 300rpm. 5.08g of sodium monochloroacetate was added, and the mixture was stirred for 10min. Then, 2.33g of sodium hydroxide was added, and the mixture was refluxed. The temperature was then raised to 75℃ and reacted for 180min. After the reaction, the temperature was lowered to 35℃, and the pH of the system was adjusted to 8 using glacial acetic acid. After filtration, the mixture was washed with ethanol and dried at 55℃ to obtain composite starch.

[0029] Preparation of esterified starch: 100g of acetic anhydride was mixed with 150g of anhydrous pyridine (CAS No.: 110-86-1), and 80g of ethylenediaminetetraacetic acid (CAS No.: 60-00-4) was added. The mixture was heated to 70℃ and stirred for 24h. After cooling to 25℃, the mixture was filtered and washed alternately with acetic anhydride and diethyl ether. After drying, ethylenediaminetetraacetic acid dianhydride was obtained. 50g of N,N-dimethylformamide, 20g of starch, and 48g of ethylenediaminetetraacetic acid dianhydride were mixed and heated to 80℃ under a nitrogen atmosphere. After reacting for 18h, the mixture was cooled to 25℃ and centrifuged to obtain a solid product. The solid product was washed with N,N-dimethylformamide, deionized water, sodium bicarbonate, and ethanol. After drying at 50℃, esterified starch was obtained.

[0030] Preparation of modified composite starch: 11.25g of esterified starch and 18.75g of composite starch were added to 200g of N,N-dimethylformamide (CAS No.: 68-12-2), centrifuged, washed and dried to obtain modified composite starch.

[0031] Preparation of waterproof coating: A waterproof coating is obtained by mixing nano-silica, organosilicon wear-resistant additive, carbodiimide (CAS No.: 151-51-9) crosslinking agent, modified composite starch and silicone resin. The proportions of nano-silica, organosilicon wear-resistant additive, carbodiimide crosslinking agent, modified composite starch and silicone resin by mass percentage are 5 wt%, 5 wt%, and 6 wt%. The balance is silicone resin.

[0032] Preparation of POE elastomer interior skin: Polypropylene, ethylene-octene copolymer (CAS No.: 26221-73-8), ethylene propylene diene monomer (EPDM) rubber, and dibromoneopentyl glycol (CAS No.: 3296-90-0) were mixed in a mass ratio of 2:2.5:1:0.3 to obtain a premix. The premix was fed into an extruder, where it was sheared and mixed by the screw in the barrel to achieve blending. At the same time, the vulcanization reaction was completed in the extruder to form a uniform elastomer film. After the film was extruded from the extruder die, it was immediately bonded to the unwound base fabric in the composite roller assembly to form a composite preform, which is the elastomer skin body. During the extruder blending stage, a dynamic crosslinking agent, triallyl isocyanurate (CAS No.: 1025-15-6), with a crosslinking degree of 5%, was added simultaneously. Using plasma treatment equipment, argon gas is introduced to form an ionized gas environment, which bombards the TPO surface layer in the composite billet, forming a nanoscale etched structure on the surface and introducing polar groups, thereby increasing the surface energy to over 60mN / m. A printing process is used to coat chlorinated polyolefin onto a surface-treated TPO layer. After drying and curing, a base layer is obtained. Then, a waterproof coating is applied to the surface of the base layer. After drying, a surface coating is formed, and a blank is obtained. The coated blank is fed into an embossing machine. The pre-set pattern is pressed onto the surface of the blank by the action of the heated pattern roller and the pressure roller. After cooling and shaping, a semi-finished product with a three-dimensional texture is obtained. By using electron beam crosslinking technology, crosslinking is performed to improve the temperature resistance and pattern retention, thus producing POE elastomer interior skin.

[0033] Example 2 Preparation of compound starch: 23.08g of starch was mixed with 50g of sodium silicate solution, pulverized and stirred evenly in a pulverizer, and activated for 60min under sealed conditions. 6.92g of dodecenylsuccinic anhydride was added and stirred evenly. Then, 10g of sodium silicate solution was added, stirred, and allowed to stand at 25℃ for 3h under sealed conditions. The temperature was then raised to 65℃ and reacted for 180min. After cooling to 25℃ and drying, pre-made starch was obtained. 50g of ethanol, 100g of deionized water, and 12g of pre-made starch were mixed and stirred at 300rpm. 5.78g of sodium monochloroacetate was added and stirred for 10min. Then, 2.22g of sodium hydroxide was added, refluxed, and then heated to 75℃ and reacted for 180min. After the reaction, the temperature was lowered to 35℃, and the pH of the system was adjusted to 8 using glacial acetic acid. After filtration, the mixture was washed with ethanol and dried at 55℃ to obtain composite starch.

[0034] Preparation of esterified starch: 100g of acetic anhydride and 150g of anhydrous pyridine were mixed, and 80g of ethylenediaminetetraacetic acid was added. The mixture was heated to 70°C and stirred for 24h. After cooling to 25°C, the mixture was filtered and washed alternately with acetic anhydride and diethyl ether. After drying, ethylenediaminetetraacetic acid dianhydride was obtained. 50g of N,N-dimethylformamide, 20g of starch, and 56g of ethylenediaminetetraacetic acid dianhydride were mixed and heated to 80°C under a nitrogen atmosphere. After reacting for 22h, the mixture was cooled to 25°C and centrifuged to obtain a solid product. The solid product was washed with N,N-dimethylformamide, deionized water, sodium bicarbonate, and ethanol. After drying at 50°C, esterified starch was obtained.

[0035] Preparation of modified composite starch: 16.67g of esterified starch and 13.33g of composite starch were added to 200g of N,N-dimethylformamide, centrifuged, washed and dried to obtain modified composite starch.

[0036] Preparation of waterproof coating: A waterproof coating is obtained by mixing nano-silica, organosilicon wear-resistant additive, carbodiimide crosslinking agent, modified composite starch and silicone resin. The proportions of nano-silica, organosilicon wear-resistant additive, perfluoroalkyl compound, carbodiimide crosslinking agent, modified composite starch and silicone resin by mass percentage are 10 wt%, 10 wt%, 5 wt%, 15 wt%, and 8 wt%. The balance is silicone resin.

[0037] Preparation of POE elastomer interior skin: Polypropylene, ethylene-octene copolymer, ethylene propylene diene monomer (EPDM) rubber, and dibromoneopentyl glycol are mixed in a mass ratio of 2:2.5:1:0.3 to obtain a premix. The premix is ​​fed into an extruder, where it is sheared and mixed by the screw inside the barrel to achieve blending. Simultaneously, a vulcanization reaction is completed in the extruder to form a uniform elastomer film. After the film is extruded from the extruder die, it is immediately bonded online with the unwound base fabric in a composite roller assembly to form a composite preform, which is the elastomer skin body. During the extruder blending stage, a dynamic crosslinking agent, triallyl isocyanurate, with a crosslinking degree of 10% is added simultaneously. Using plasma treatment equipment, argon gas is introduced to form an ionized gas environment, which bombards the TPO surface layer in the composite billet, forming a nanoscale etched structure on the surface and introducing polar groups, thereby increasing the surface energy to over 60mN / m. A printing process is used to coat chlorinated polyolefin onto a surface-treated TPO layer. After drying and curing, a base layer is obtained. Then, a waterproof coating is applied to the surface of the base layer. After drying, a surface coating is formed, and a blank is obtained. The coated blank is fed into an embossing machine. The pre-set pattern is pressed onto the surface of the blank by the action of the heated pattern roller and the pressure roller. After cooling and shaping, a semi-finished product with a three-dimensional texture is obtained. By using electron beam crosslinking technology, crosslinking is performed to improve the temperature resistance and pattern retention, thus producing POE elastomer interior skin.

[0038] Example 3 Preparation of compound starch: 24g of starch was mixed with 50g of sodium silicate solution, pulverized and stirred evenly in a pulverizer, and activated for 60min under sealed conditions. 6g of dodecenylsuccinic anhydride was added and stirred evenly. Then 10g of sodium silicate solution was added, stirred, and allowed to stand at 25℃ for 3h under sealed conditions. The temperature was then raised to 60℃ and reacted for 180min. After cooling to 25℃ and drying, pre-made starch was obtained. 50g of ethanol, 100g of deionized water and 12.27g of pre-made starch were mixed and stirred at 300rpm. 5.46g of sodium monochloroacetate was added and stirred for 10min. Then 2.27g of sodium hydroxide was added, refluxed, and then heated to 75℃ and reacted for 180min. After the reaction, the temperature was lowered to 35℃, and the pH of the system was adjusted to 8 using glacial acetic acid. After filtration, the mixture was washed with ethanol and dried at 55℃ to obtain composite starch.

[0039] Preparation of esterified starch: 100g of acetic anhydride and 150g of anhydrous pyridine were mixed, and 80g of ethylenediaminetetraacetic acid was added. The mixture was heated to 70°C and stirred for 24h. After cooling to 25°C, the mixture was filtered and washed alternately with acetic anhydride and diethyl ether. After drying, ethylenediaminetetraacetic acid dianhydride was obtained. 50g of N,N-dimethylformamide, 20g of starch, and 52g of ethylenediaminetetraacetic acid dianhydride were mixed and heated to 80°C under a nitrogen atmosphere. After reacting for 20h, the mixture was cooled to 25°C and centrifuged to obtain a solid product. The solid product was washed with N,N-dimethylformamide, deionized water, sodium bicarbonate, and ethanol. After drying at 50°C, esterified starch was obtained.

[0040] Preparation of modified composite starch: 17.65g of esterified starch and 12.35g of composite starch were added to 200g of N,N-dimethylformamide, centrifuged, washed and dried to obtain modified composite starch.

[0041] Preparation of waterproof coating: A waterproof coating is obtained by mixing nano-silica, organosilicon wear-resistant additive, carbodiimide crosslinking agent, modified composite starch and silicone resin. By mass percentage, the proportions are: nano-silica 7wt%, organosilicon wear-resistant additive 7wt%, perfluoroalkyl compound 2.5wt%, carbodiimide crosslinking agent 10wt%, modified composite starch 7wt%, and the balance is silicone resin.

[0042] Preparation of POE elastomer interior skin: Polypropylene, ethylene-octene copolymer, ethylene propylene diene monomer (EPDM) rubber, vinylbenzene, dibromoneopentyl glycol, and dynamic crosslinking agent triallyl isocyanurate were mixed in a mass ratio of 2:2.5:1:1:0.3 to obtain a premix. The premix was fed into an extruder, where it was sheared and mixed by the screw in the barrel to achieve blending. At the same time, a vulcanization reaction was completed in the extruder to form a uniform elastomer film. After the film was extruded from the extruder die, it was immediately bonded online with the unwound base fabric in a composite roller assembly to form a composite preform, which yielded the elastomer skin body. The dynamic crosslinking agent triallyl isocyanurate was added simultaneously during the extruder blending stage, with a crosslinking degree of 7%. Using plasma treatment equipment, argon gas is introduced to form an ionized gas environment, which bombards the TPO surface layer in the composite billet, forming a nanoscale etched structure on the surface and introducing polar groups, thereby increasing the surface energy to over 60mN / m. A printing process is used to coat chlorinated polyolefin onto a surface-treated TPO layer. After drying and curing, a base layer is obtained. Then, a waterproof coating is applied to the surface of the base layer. After drying, a surface coating is formed, and a blank is obtained. The coated blank is fed into an embossing machine. The pre-set pattern is pressed onto the surface of the blank by the action of the heated pattern roller and the pressure roller. After cooling and shaping, a semi-finished product with a three-dimensional texture is obtained. By using electron beam crosslinking technology, crosslinking is performed to improve the temperature resistance and pattern retention, thus producing POE elastomer interior skin.

[0043] Example 4 Example 4 is based on Example 3. In Example 4, when preparing the pre-made starch, 27.27g of starch and 2.73g of dodecenyl succinic anhydride were used.

[0044] Example 5 Example 5 is based on Example 3. In Example 5, when preparing the pre-made starch, 21.43g of starch and 8.57g of dodecenyl succinic anhydride were used.

[0045] Example 6 Example 6 is based on Example 3. In Example 6, when preparing the composite starch, the amount of pre-made starch used is 13.67g, the amount of sodium monochloroacetate used is 3.8g, and the amount of sodium hydroxide used is 2.53g.

[0046] Example 7 Example 7 is based on Example 3. In Example 7, when preparing the composite starch, the amount of pre-prepared starch used is 10.91g, the amount of monochloroacetic acid used is 7.07g, and the amount of sodium hydroxide used is 2.02g.

[0047] Example 8 Example 8 is based on Example 3. In Example 8, 40g of ethylenediaminetetraacetic acid dianhydride was added during the preparation of esterified starch.

[0048] Example 9 Example 9 is based on Example 3. In Example 9, 64g of ethylenediaminetetraacetic acid dianhydride was added during the preparation of esterified starch.

[0049] Example 10 Example 10 is based on Example 3. In Example 10, the esterification time for preparing esterified starch is 15 hours.

[0050] Example 11 Example 11 is based on Example 3. In Example 10, the esterification interval was 23 hours when preparing esterified starch.

[0051] Example 12 Example 12 is based on Example 3. In Example 12, when preparing the modified composite starch, the amount of composite starch used is 21.43g and the amount of esterified starch used is 8.57g.

[0052] Example 13 Example 13 is based on Example 3. In Example 13, when preparing the modified composite starch, the amount of composite starch used is 15g and the amount of esterified starch used is 15g.

[0053] Comparative Example 1 Comparative Example 1 is based on Example 3. In Comparative Example 1, the composite starch was not treated with sodium monochloroacetate and sodium hydroxide.

[0054] Comparative Example 2 Comparative Example 2 is based on Example 3, except that in the preparation of the composite starch, the pre-made starch was replaced with ordinary starch.

[0055] Performance testing Samples from Examples 1-13 and Comparative Examples 1-2 were taken and subjected to the following performance tests: (1) Hydrophobic properties Test the hydrophobic angle of the sample surface and fill in the test results in Table 1.

[0056] (2) Mechanical strength Using ASTM D-412 as the testing reference, the tensile strength of the specimens was tested three times, and the test results were recorded in Table 1. Using ASTM D-412 as the testing reference, the elongation at break of the specimens was tested. Each specimen was tested three times, and the average value was taken. The test results were recorded in Table 1.

[0057] Table 1 Performance test results of Examples 1-13 and Comparative Examples 1-2 As shown in Table 1, the hydrophobic angles of Examples 1-3 are all above 135°, indicating that the POE elastomer interior skin prepared in this application has good waterproof effect; the tensile strength of Examples 1-3 is all above 22MPa, and the elongation at break is all above 680%, indicating that the POE elastomer interior skin prepared in this application has good mechanical strength.

[0058] In Examples 4 and 5, the mass ratio between starch and dodecenyl succinic anhydride during the preparation of pre-prepared starch was not within the range specified in this application. When the amount of dodecenyl succinic anhydride added was too small, it was difficult to further improve the surface tension of the prepared pre-prepared starch, resulting in poor viscosity improvement and difficulty in further stabilizing its dispersion in the coating system. When the amount of dodecenyl succinic anhydride added was too large, the reaction efficiency was affected, resulting in excessive system viscosity, decreased stability, and difficulty in uniformly dispersing the prepared pre-prepared starch. The performance of the subsequently prepared composite starch also decreased, affecting the stability of the system. Therefore, the performance of Examples 4 and 5 decreased.

[0059] In Examples 6 and 7, the mass ratio of pre-prepared starch, monochloroacetic acid, and sodium hydroxide during the preparation of composite starch was not within the range specified in this application. When the amount of sodium monochloroacetate added was too small or too large, the degree of substitution of dodecenyl succinic anhydride was difficult to further increase, and the viscosity of the system was too large, which reduced the stability of the prepared composite starch and made it difficult to disperse evenly in the system, affecting the overall stability of the system. This resulted in a decrease in the hydrophobic properties and mechanical strength of the hydrophobic coating on the surface.

[0060] In Examples 8 and 9, the mass ratio of starch to ethylenediaminetetraacetic dianhydride decreased during the preparation of esterified starch. When the amount of ethylenediaminetetraacetic dianhydride added was too small, it was difficult to further improve the hydrophobic properties and compatibility of the starch, thus reducing the stability of the prepared hydrophobic coating. When the amount of ethylenediaminetetraacetic dianhydride added was too large, the steric hindrance of the starch restricted the hydroxyl groups of ethylenediaminetetraacetic dianhydride, and the stability of the system decreased. Therefore, Examples 8 and 9 could not be further stabilized on the bottom surface, thus affecting the overall stability of the system. As a result, the performance of Examples 8 and 9 decreased.

[0061] In Examples 10 and 11, the esterification time was not within the range specified in this application when preparing esterified starch. When the esterification time was too short, the esterification reaction was insufficient and the stability of the system decreased. When the esterification time was too long, side reactions may occur, affecting the overall purity and stability of the system. Therefore, the performance of Examples 10 and 11 decreased.

[0062] In Examples 12 and 13, the mass ratio between the composite starch and the esterified starch during the preparation of the modified composite starch was not within the range specified in this application. When the content of esterified starch was too high or too low, the bonding stability between the modified composite starches was affected, thereby affecting the overall stability of the hydrophobic coating.

[0063] In Comparative Example 1, the composite starch was not treated with sodium monochloroacetate and sodium hydroxide. It was simply a combination of starch treated with dodecenyl succinic anhydride and esterified starch. This made it difficult to further improve the surface activity of the composite starch, which reduced the stability of the modified composite starch in the coating system and caused agglomeration, thus affecting the overall stability of the comfort coating.

[0064] In Comparative Example 2, when preparing composite starch, the pre-prepared starch was replaced with ordinary starch. The starch that was not modified with dodecenyl succinic anhydride was difficult to further improve the viscosity, surface tension and stability of the starch. The stability of the prepared starch decreased, which affected the stability of the prepared hydrophobic coating.

[0065] This specific embodiment is merely an explanation of this application and is not intended to limit it. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification but must be determined according to the scope of the claims.

Claims

1. A POE elastomeric interior skin characterized by: The hydrophobic coating includes the following components by mass percentage: Nano-silicon dioxide 5-10wt%, silicone wear-resistant additive 5-10wt%, perfluoroalkyl compound 0-5wt%, carbonized diimine crosslinking agent 5-15wt%, modified composite starch 6-8wt%, and the rest is silicone resin; The modified composite starch includes composite starch and esterified starch, and the composite starch raw material includes starch, sodium monochloroacetate, sodium hydroxide and dodecenyl succinic anhydride.

2. A POE elastomeric interior skin according to claim 1, wherein: The composite starch is prepared by the following method: The starch is mixed and activated with sodium silicate solution, dodecenyl succinic anhydride is added and stirred uniformly, then sodium silicate solution is added, stirred and then placed, heated and reacted, dried to obtain pre-prepared starch, ethanol, water and pre-prepared starch are mixed and stirred, sodium monochloroacetate is added, stirred, then sodium hydroxide is added, condensed and refluxed, heated and reacted, cooled, filtered and washed, and dried to obtain composite starch.

3. A POE elastomeric interior skin according to claim 1, wherein: The mass ratio between the starch and dodecenyl succinic anhydride is 1:(0.2-0.3).

4. The POE elastomeric interior skin of claim 1, wherein: The mass ratio between the pre-prepared starch, sodium monochloroacetate and sodium hydroxide is 5.4:(2.2-2.6):

1.

5. The POE elastomeric interior skin of claim 1, wherein: The esterified starch raw material includes ethylenediaminetetraacetic dianhydride and starch, and the esterified starch is prepared by the following method: The acetic anhydride is mixed with anhydrous pyridine, ethylenediaminetetraacetic acid is added, heated and stirred, cooled, filtered and washed, and dried to obtain ethylenediaminetetraacetic dianhydride; N,N-dimethylformamide, starch and ethylenediaminetetraacetic dianhydride are mixed, heated to react, cooled, centrifuged to obtain solid product, washed and dried to obtain esterified starch.

6. A POE elastomeric interior skin according to claim 5, wherein: The mass ratio between the ethylenediaminetetraacetic dianhydride and starch is 1:(2.4-2.8).

7. A POE elastomeric interior skin according to claim 5, wherein: The reaction time between the starch and ethylenediaminetetraacetic dianhydride is 18-22h.

8. A POE elastomeric interior skin according to claim 1, wherein: The mass ratio between the composite starch and esterified starch is 1:(0.6-0.8).

9. A POE elastomeric interior skin according to claim 1, wherein: The elastomer skin body is prepared from a thermoplastic polyolefin elastomer mixture including ethylene-octene copolymer, ternary ethylene-propylene rubber, dibromoneopentyl glycol and dynamic crosslinking agent.

10. A method of making the POE elastomeric interior skin of any of claims 1-9, wherein: The method includes the following steps: The elastomer skin body raw material is added to the extruder for blending, and vulcanization is completed in the extruder to form an elastomer film material, which is then combined with the unwound base cloth to form a composite blank, i.e. the elastomer skin body; The TPO surface layer in the composite blank is modified by ionized gas; A chlorinated polyolefin is coated on the surface-treated TPO surface layer by printing process to form a bottom layer coating after curing, and then a waterproof coating is coated on the surface of the bottom layer coating to form a surface coating after drying, and a blank is formed; The coated blank is embossed, and a semi-finished product with three-dimensional texture is obtained after cooling and setting; POE elastomer interior skin is prepared by crosslinking through electron irradiation crosslinking technology to improve temperature resistance and pattern retention.

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