Easy-to-clean coating for door sealing strip and preparation method of easy-to-clean coating

Abstract

The invention discloses an easy-to-clean coating for a door sealing strip and a preparation method of the easy-to-clean coating, and belongs to the technical field of door sealing strip coatings. The invention relates to a preparation method of an easy-to-clean coating for a door sealing strip, which specifically comprises the following steps: uniformly mixing modified polysiloxane and carboxyl functionalized silicon dioxide to form a coating turbid liquid, coating a door sealing strip substrate with the coating turbid liquid, forming transparent silicon rubber after a solvent is volatilized, and heating at 80-100 DEG C for 10-40 minutes to form the easy-to-clean coating for the door sealing strip. According to the easy-to-clean coating for the door sealing strip, carboxyl functionalized silicon dioxide is adopted as a cross-linking agent, and modified polysiloxane with small-molecule quaternary ammonium salt and fluorine-containing siloxane is cross-linked to form a network under the reaction condition, so that the easy-to-clean characteristic of the easy-to-clean coating for the door sealing strip is realized, and the easy-to-clean coating for the door sealing strip has the characteristics of being antibacterial, mildew-proof and smooth in hand feeling; and a new reference is provided for realizing the easy-to-clean function of the door sealing strip.

Description

Technical Field

[0001] The invention belongs to the technical field of door sealing strip coatings, and in particular relates to an easy-to-clean coating for a door sealing strip and a preparation method thereof. Background Art

[0002] The refrigerator door seal is a kind of accessory used to seal between the refrigerator door and the refrigerator body. It is usually composed of two parts: one is a soft polyvinyl chloride jacket, and the other is a magnetic strip. Usually, the quality of the seal will directly affect the sealing, heat preservation, refrigeration effect and service life of the refrigerator. It is absolutely a "small material with great use".

[0003] In actual use, refrigerator door seals easily accumulate dirt, grease and mold, which not only affects the appearance, but may also breed bacteria and endanger the health of users. Traditional cleaning methods usually require manual cleaning with detergents and brushes, which is time-consuming and labor-intensive with limited effectiveness. In addition, frequent cleaning may also cause wear on the surface of the seal, affecting its sealing performance and service life.

[0004] In recent years, as people's awareness of home hygiene and health has increased, the development of a door seal coating with an easy-to-clean function has become an industry hotspot to solve the problem. In the prior art, there are some patents on easy-to-clean coatings. For example, patent CN110183880A discloses a photocatalytic super-amphiphobic coating and its preparation method and application. The patent achieves self-cleaning by adding a photocatalyst to the coating using photocatalytic action. However, this method requires ultraviolet irradiation to work, and its effect is limited in the environment of insufficient light inside the refrigerator.

[0005] Therefore, it is of great practical significance to develop a door sealing strip coating that does not require special conditions, is mildew-proof and antibacterial, is easy to clean, and does not affect the performance of the sealing strip. Summary of the invention

[0006] The object of the present invention is to provide an easy-to-clean coating for a door sealing strip and a preparation method thereof, so as to solve the problems existing in the existing door sealing strip coating technology, such as difficulty in cleaning stains and easy breeding of mold and bacteria.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A method for preparing an easy-to-clean coating for a door sealing strip comprises the following steps:

[0009] The modified polysiloxane and carboxyl functionalized silica are uniformly mixed to form a coating suspension, which is then applied to the door sealing strip substrate. After the solvent evaporates, transparent silicone rubber is formed, which is then heated at 80-100°C for 10-40 minutes to form an easy-to-clean coating for the door sealing strip.

[0010] Furthermore, the mass ratio of the modified polysiloxane to the carboxyl functionalized silica is 5:0.32-1.6.

[0011] Furthermore, the modified polysiloxane is prepared by the following steps:

[0012] Octamethylcyclotetrasiloxane, γ-diethylenetriaminepropylmethyldimethoxysilane, dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, perfluorooctyltrimethoxysilane, hexamethyldisiloxane, tetramethylammonium hydroxide and deionized water are mixed; under N2 protection, the mixture is stirred at 90-100°C for 4-6 hours, and then the mixture is heated to 140-150°C and kept for 0.5-1 hour to obtain modified polysiloxane;

[0013] Furthermore, the mass ratio of octamethylcyclotetrasiloxane, γ-diethylenetriaminepropylmethyldimethoxysilane, dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, perfluorooctyltrimethoxysilane, hexamethyldisiloxane, tetramethylammonium hydroxide and deionized water is 100:9-70:0.5-0.9:0.5-0.9:0.5-0.9:0.5-0.9:1-10.

[0014] Furthermore, the carboxyl functionalized silica is prepared by the following steps:

[0015] 2-Cyanoethyltriethoxysilane is added to 30 mL of water, and after being fully dispersed, ammonia water is added, and the product is stirred at room temperature for 4-5 hours, and then centrifuged and washed with water and ethanol for 3-5 times to remove unreacted products, and then the product is placed at 60-70°C and dried for 10-12 hours to obtain a carboxyl functionalized silica intermediate;

[0016] The carboxyl functionalized silica intermediate is uniformly dispersed in a sulfuric acid solution and stirred at 60-70°C for 24 hours; after the reaction is completed, the product is centrifuged, washed with water and ethanol for 3-5 times in sequence, and then the product is placed at 60-70°C and dried for 10-12 hours to obtain carboxyl functionalized silica;

[0017] Furthermore, the purity of 2-cyanoethyltriethoxysilane is 95%; the mass fraction of ammonia water is 25-28%; the volume ratio of 2-cyanoethyltriethoxysilane and ammonia water is 1:1; and the mass fraction of sulfuric acid solution is 30%.

[0018] Furthermore, the ratio of the carboxyl functionalized silica intermediate to the sulfuric acid solution is 0.1 g:30 mL.

[0019] Furthermore, the coating is performed by spraying or brushing; the process parameters of the spraying are a spray gun diameter of 1.2 mm, a spraying pressure of 0.8 MPa, and a spray gun distance of 20 cm.

[0020] Furthermore, the door sealing strip substrate is made of materials such as polyvinyl chloride or thermoplastic elastomer.

[0021] An easy-to-clean coating for a door sealing strip is prepared by the above-mentioned preparation method.

[0022] Beneficial effects of the present invention:

[0023] (1) The present invention uses carboxyl functionalized silica as a cross-linking agent to combine the -NH2 group on the surface of the modified polysiloxane with the -COOH group of the carboxyl functionalized silica to form a cross-linking network, so that the nano-silica in the carboxyl functionalized silica forms a nano-rough structure in the easy-to-clean coating of the door sealing strip; in addition, the large amount of fluorine atoms present in the perfluorooctyltrimethoxysilane in the modified polysiloxane reduces the surface energy of the easy-to-clean coating of the door sealing strip, so that the easy-to-clean coating of the door sealing strip has a surface hydrophobic and oleophobic effect, thereby achieving the purpose of easy cleaning.

[0024] (2) The present invention uses dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride as an antibacterial functional monomer and uses a cross-linking agent to form a mesh-structured easy-to-clean coating for door sealing strips, in which the antibacterial functional monomer is evenly distributed, thereby greatly increasing the molecular weight of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, thereby transforming the originally small molecule quaternary ammonium salt antibacterial agent that only has antibacterial effect into a high molecular quaternary ammonium salt that has both antibacterial and antifungal effects, thereby achieving the purpose of antibacterial and mildew-proofing the easy-to-clean coating for door sealing strips.

[0025] (3) The present invention performs carboxyl modification on nano-silicon dioxide so that the carboxyl functionalized silicon dioxide is evenly distributed in the easy-to-clean coating of the door sealing strip. This uniform arrangement achieves the effect of making the easy-to-clean coating of the door sealing strip feel smooth. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] This embodiment provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0029] S1. Preparation of modified polysiloxane:

[0030] 100 g of octamethylcyclotetrasiloxane, 9 g of γ-diethylenetriaminepropylmethyldimethoxysilane, 0.5 g of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 0.5 g of perfluorooctyltrimethoxysilane, 0.5 g of hexamethyldisiloxane, 0.5 g of tetramethylammonium hydroxide and 1 g of deionized water were added into a sealed container, stirred and reacted at 90° C. for 6 h under N2 protection, heated to 150° C. and kept warm for 0.5 h, the catalyst was decomposed and low-boiling substances were removed under reduced pressure to obtain modified polysiloxane;

[0031] S2. Preparation of carboxyl functionalized silica:

[0032] 1 mL of 95% pure 2-cyanoethyltriethoxysilane was added to 30 mL of aqueous solution under vigorous stirring. After being fully dispersed, 1 mL of 25% ammonia water was added. The solution was stirred at room temperature for 4 hours. After the reaction was completed, the product was centrifuged and washed with water and ethanol three times in sequence. The product was then placed in a 60°C constant temperature drying oven and dried for 10 hours to obtain a carboxyl functionalized silica intermediate.

[0033] 0.1 g of the carboxyl functionalized silica intermediate prepared in the previous step was uniformly dispersed in 30 mL of a 30% sulfuric acid aqueous solution, and stirred at 60° C. for 24 h. After the reaction was completed, the product was centrifuged, washed with water and ethanol three times in sequence, and then placed in a 60° C. constant temperature drying oven and dried for 10 h to obtain carboxyl functionalized silica.

[0034] S3. Preparation of easy-to-clean coating for door sealing strips:

[0035] 5 g of modified polysiloxane and 0.32 g of carboxyl functionalized silica are mixed evenly to form a coating suspension; the modified polysiloxane and carboxyl functionalized silica are mixed evenly to form a coating suspension, and the coating suspension is sprayed on the polyvinyl chloride substrate of the door sealing strip, and transparent silicone rubber is formed after the solvent evaporates, and then heated at 80°C for 40 minutes to form an easy-to-clean coating for the door sealing strip.

[0036] Example 2

[0037] This embodiment provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0038] S1. Preparation of modified polysiloxane:

[0039] 100 g of octamethylcyclotetrasiloxane, 9 g of γ-diethylenetriaminepropylmethyldimethoxysilane, 0.5 g of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 0.5 g of perfluorooctyltrimethoxysilane, 0.5 g of hexamethyldisiloxane, 0.5 g of tetramethylammonium hydroxide and 1 g of deionized water were added into a sealed container, stirred and reacted at 90° C. for 6 h under N2 protection, heated to 150° C. and kept warm for 0.5 h, the catalyst was decomposed and low-boiling substances were removed under reduced pressure to obtain modified polysiloxane;

[0040] S2. Preparation of carboxyl functionalized silica:

[0041] 1 mL of 95% pure 2-cyanoethyltriethoxysilane was added to 30 mL of aqueous solution under vigorous stirring. After being fully dispersed, 1 mL of 28% ammonia water was added. The solution was stirred at room temperature for 5 hours. After the reaction was completed, the product was centrifuged and washed with water and ethanol for 5 times in sequence. The product was then placed in a 70°C constant temperature drying oven and dried for 12 hours to obtain a carboxyl functionalized silica intermediate.

[0042] Take 0.1g of the carboxyl functionalized silica intermediate prepared in the previous step and evenly disperse it in 30mL of 30% sulfuric acid aqueous solution, and stir it at 70°C for 24h; after the reaction, centrifuge the product, wash it with water and ethanol 5 times in sequence, and then place the product in a constant temperature drying oven at 70°C and dry it for 12h to obtain carboxyl functionalized silica.

[0043] S3. Preparation of easy-to-clean coating for door sealing strips:

[0044] 5 g of modified polysiloxane and 0.32 g of carboxyl functionalized silica are mixed evenly to form a coating suspension; the modified polysiloxane and carboxyl functionalized silica are mixed evenly to form a coating suspension, and the coating suspension is sprayed on the polyvinyl chloride substrate of the door sealing strip, and transparent silicone rubber is formed after the solvent evaporates, and then heated at 80°C for 40 minutes to form an easy-to-clean coating for the door sealing strip.

[0045] Example 3

[0046] This embodiment provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0047] S1. Preparation of modified polysiloxane:

[0048] 100 g of octamethylcyclotetrasiloxane, 20 g of γ-diethylenetriaminepropylmethyldimethoxysilane, 0.6 g of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 0.65 g of perfluorooctyltrimethoxysilane, 0.6 g of hexamethyldisiloxane, 0.6 g of tetramethylammonium hydroxide and 3 g of deionized water are added into a sealed container, stirred and reacted at 95 ° C for 5 h under N2 protection, heated to 145 ° C and kept warm for 45 min, the catalyst is decomposed and low boiling points are removed under reduced pressure to obtain modified polysiloxane.

[0049] S2. Preparation of carboxyl functionalized silica:

[0050] 1 mL of 95% pure 2-cyanoethyltriethoxysilane was added to 30 mL of aqueous solution under vigorous stirring. After being fully dispersed, 1 mL of 25% ammonia water was added. The solution was stirred at room temperature for 4 hours. After the reaction was completed, the product was centrifuged and washed with water and ethanol three times in sequence. The product was then placed in a 60°C constant temperature drying oven and dried for 10 hours to obtain a carboxyl functionalized silica intermediate.

[0051] 0.1 g of the carboxyl functionalized silica intermediate prepared in the previous step was uniformly dispersed in 30 mL of a 30% sulfuric acid aqueous solution, and stirred at 60° C. for 24 h. After the reaction was completed, the product was centrifuged, washed with water and ethanol three times in sequence, and then placed in a 60° C. constant temperature drying oven and dried for 10 h to obtain carboxyl functionalized silica.

[0052] S3. Preparation of easy-to-clean coating for door sealing strips:

[0053] 5 g of modified polysiloxane and 0.32 g of carboxyl functionalized silica are mixed evenly to form a coating suspension; the modified polysiloxane and carboxyl functionalized silica are mixed evenly to form a coating suspension, and the coating suspension is then brushed on the thermoplastic elastomer (alloy formed by TPU and SEBS) as the base material of the door sealing strip, and transparent silicone rubber can be formed after the solvent evaporates, and then heated at 90°C for 20 minutes to form an easy-to-clean coating for the door sealing strip.

[0054] Example 4

[0055] This embodiment provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0056] S1. Preparation of modified polysiloxane:

[0057] 100 g of octamethylcyclotetrasiloxane, 20 g of γ-diethylenetriaminepropylmethyldimethoxysilane, 0.6 g of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 0.65 g of perfluorooctyltrimethoxysilane, 0.6 g of hexamethyldisiloxane, 0.6 g of tetramethylammonium hydroxide and 3 g of deionized water are added into a sealed container, stirred and reacted at 95 ° C for 5 h under N2 protection, heated to 145 ° C and kept warm for 45 min, the catalyst is decomposed and low boiling points are removed under reduced pressure to obtain modified polysiloxane.

[0058] S2. Preparation of carboxyl functionalized silica:

[0059] 1 mL of 95% pure 2-cyanoethyltriethoxysilane was added to 30 mL of aqueous solution under vigorous stirring. After being fully dispersed, 1 mL of 28% ammonia water was added. The solution was stirred at room temperature for 5 hours. After the reaction was completed, the product was centrifuged and washed with water and ethanol for 5 times in sequence. The product was then placed in a 70°C constant temperature drying oven and dried for 12 hours to obtain a carboxyl functionalized silica intermediate.

[0060] Take 0.1g of the carboxyl functionalized silica intermediate prepared in the previous step and evenly disperse it in 30mL of 30% sulfuric acid aqueous solution, and stir it at 70°C for 24h; after the reaction, centrifuge the product, wash it with water and ethanol 5 times in sequence, and then place the product in a constant temperature drying oven at 70°C and dry it for 12h to obtain carboxyl functionalized silica.

[0061] S3. Preparation of easy-to-clean coating for door sealing strips:

[0062] 5 g of modified polysiloxane and 0.32 g of carboxyl functionalized silica are mixed evenly to form a coating suspension; the modified polysiloxane and carboxyl functionalized silica are mixed evenly to form a coating suspension, and the coating suspension is then brushed on the thermoplastic elastomer (alloy formed by TPU and SEBS) as the base material of the door sealing strip, and transparent silicone rubber can be formed after the solvent evaporates, and then heated at 90°C for 20 minutes to form an easy-to-clean coating for the door sealing strip.

[0063] Example 5

[0064] This embodiment provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0065] S1. Preparation of modified polysiloxane:

[0066] 100 g of octamethylcyclotetrasiloxane, 30 g of γ-diethylenetriaminepropylmethyldimethoxysilane, 0.7 g of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 0.7 g of perfluorooctyltrimethoxysilane, 0.7 g of hexamethyldisiloxane, 0.7 g of tetramethylammonium hydroxide and 5 g of deionized water were added into a sealed container, stirred and reacted at 100° C. for 4 h under N2 protection, heated to 140° C. and kept warm for 1 h, the catalyst was decomposed and low-boiling substances were removed under reduced pressure to obtain modified polysiloxane;

[0067] S2. Preparation of carboxyl functionalized silica:

[0068] 1 mL of 95% pure 2-cyanoethyltriethoxysilane was added to 30 mL of aqueous solution under vigorous stirring. After being fully dispersed, 1 mL of 25% ammonia water was added. The solution was stirred at room temperature for 4 hours. After the reaction was completed, the product was centrifuged and washed with water and ethanol three times in sequence. The product was then placed in a 60°C constant temperature drying oven and dried for 10 hours to obtain a carboxyl functionalized silica intermediate.

[0069] 0.1 g of the carboxyl functionalized silica intermediate prepared in the previous step was uniformly dispersed in 30 mL of a 30% sulfuric acid aqueous solution, and stirred at 60° C. for 24 h. After the reaction was completed, the product was centrifuged, washed with water and ethanol three times in sequence, and then placed in a 60° C. constant temperature drying oven and dried for 10 h to obtain carboxyl functionalized silica.

[0070] S3. Preparation of easy-to-clean coating for door sealing strips:

[0071] 5 g of modified polysiloxane and 1.6 g of carboxyl functionalized silica are mixed evenly to form a coating suspension; the modified polysiloxane and carboxyl functionalized silica are mixed evenly to form a coating suspension, and the coating suspension is sprayed on the polyvinyl chloride substrate of the door sealing strip, and transparent silicone rubber is formed after the solvent evaporates, and then heated at 100°C for 10 minutes to form an easy-to-clean coating for the door sealing strip.

[0072] Example 6

[0073] This embodiment provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0074] S1. Preparation of modified polysiloxane:

[0075] 100 g of octamethylcyclotetrasiloxane, 30 g of γ-diethylenetriaminepropylmethyldimethoxysilane, 0.7 g of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 0.7 g of perfluorooctyltrimethoxysilane, 0.7 g of hexamethyldisiloxane, 0.7 g of tetramethylammonium hydroxide and 5 g of deionized water were added into a sealed container, stirred and reacted at 100° C. for 4 h under N2 protection, heated to 140° C. and kept warm for 1 h, the catalyst was decomposed and low-boiling substances were removed under reduced pressure to obtain modified polysiloxane;

[0076] S2. Preparation of carboxyl functionalized silica:

[0077] 1 mL of 95% pure 2-cyanoethyltriethoxysilane was added to 30 mL of aqueous solution under vigorous stirring. After being fully dispersed, 1 mL of 28% ammonia water was added. The solution was stirred at room temperature for 5 hours. After the reaction was completed, the product was centrifuged and washed with water and ethanol for 5 times in sequence. The product was then placed in a 70°C constant temperature drying oven and dried for 12 hours to obtain a carboxyl functionalized silica intermediate.

[0078] 0.1 g of the carboxyl functionalized silica intermediate prepared in the previous step was uniformly dispersed in 30 mL of a 30% sulfuric acid aqueous solution, and stirred at 70° C. for 24 h. After the reaction was completed, the product was centrifuged, washed with water and ethanol five times in sequence, and then placed in a 70° C. constant temperature drying oven to dry for 12 h, thereby obtaining carboxyl functionalized silica.

[0079] S3. Preparation of easy-to-clean coating for door sealing strips:

[0080] 5 g of modified polysiloxane and 1.6 g of carboxyl functionalized silica are mixed evenly to form a coating suspension; the modified polysiloxane and carboxyl functionalized silica are mixed evenly to form a coating suspension, and the coating suspension is sprayed on the polyvinyl chloride substrate of the door sealing strip, and transparent silicone rubber is formed after the solvent evaporates, and then heated at 100°C for 10 minutes to form an easy-to-clean coating for the door sealing strip.

[0081] Comparative Example 1

[0082] This comparative example provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0083] Compared with Example 1, S1 in Example 1, preparation of modified polysiloxane, is replaced by the following steps: 100g octamethylcyclotetrasiloxane, 9g γ-diethylenetriaminepropylmethyldimethoxysilane, 0.5g hexadecyltrimethylammonium bromide, 0.5g perfluoropolyether, 0.5g hexamethyldisiloxane, 0.5g tetramethylammonium hydroxide and 1g deionized water are added to a sealed container, stirred and reacted at 90°C for 6h under N2 protection, heated to 150°C and kept warm for 0.5h, decomposed the catalyst and removed low boiling points under reduced pressure to obtain modified polysiloxane; the remaining raw materials and preparation process are the same as those in Example 1.

[0084] Comparative Example 2

[0085] This comparative example provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0086] S1. Preparation of modified polysiloxane:

[0087] 100 g of octamethylcyclotetrasiloxane, 9 g of γ-diethylenetriaminepropylmethyldimethoxysilane, 0.5 g of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 0.5 g of perfluorooctyltrimethoxysilane, 0.5 g of hexamethyldisiloxane, 0.5 g of tetramethylammonium hydroxide and 1 g of deionized water were added into a sealed container, stirred and reacted at 90° C. for 6 h under N2 protection, heated to 150° C. and kept warm for 0.5 h, the catalyst was decomposed and low-boiling substances were removed under reduced pressure to obtain modified polysiloxane;

[0088] S2. Preparation of easy-to-clean coating for door sealing strips:

[0089] 5 g of modified polysiloxane and 0.32 g of citric acid are mixed evenly to form a coating suspension; the modified polysiloxane and carboxyl functionalized silica are mixed evenly to form a coating suspension, and the coating suspension is then sprayed on the polyvinyl chloride substrate of the door sealing strip. After the solvent evaporates, transparent silicone rubber can be formed, and then heated at 80°C for 40 minutes to form an easy-to-clean coating for the door sealing strip.

[0090] Comparative Example 3

[0091] This comparative example provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0092] S1. Preparation of modified polysiloxane:

[0093] 100 g of octamethylcyclotetrasiloxane, 9 g of γ-diethylenetriaminepropylmethyldimethoxysilane, 0.5 g of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 0.5 g of perfluorooctyltrimethoxysilane, 0.5 g of hexamethyldisiloxane, 0.5 g of tetramethylammonium hydroxide and 1 g of deionized water were added into a sealed container, stirred and reacted at 90° C. for 6 h under N2 protection, heated to 150° C. and kept warm for 0.5 h, the catalyst was decomposed and low-boiling substances were removed under reduced pressure to obtain modified polysiloxane;

[0094] S2. Preparation of easy-to-clean coating for door sealing strips:

[0095] Mix 5g of modified polysiloxane and 0.32g of nano-silica evenly to form a coating suspension; mix the modified polysiloxane and carboxyl-functionalized silica evenly to form a coating suspension, and then spray the coating suspension on the polyvinyl chloride substrate of the door sealing strip. After the solvent evaporates, transparent silicone rubber can be formed, and then heated at 80°C for 40 minutes to form an easy-to-clean coating for the door sealing strip.

[0096] Comparative Example 4

[0097] This comparative example provides an easy-to-clean coating for a door sealing strip, which is prepared by the following steps:

[0098] S1. Preparation of modified polysiloxane:

[0099] 100 g of octamethylcyclotetrasiloxane, 9 g of γ-diethylenetriaminepropylmethyldimethoxysilane, 0.5 g of dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 0.5 g of perfluorooctyltrimethoxysilane, 0.5 g of hexamethyldisiloxane, 0.5 g of tetramethylammonium hydroxide and 1 g of deionized water were added into a sealed container, stirred and reacted at 90° C. for 6 h under N2 protection, heated to 150° C. and kept warm for 0.5 h, the catalyst was decomposed and low-boiling substances were removed under reduced pressure to obtain modified polysiloxane;

[0100] S2. Preparation of easy-to-clean coating for door sealing strips:

[0101] A mixture of 5g of modified polysiloxane, 0.16g of citric acid and 0.16g of nano-silica was mixed evenly to form a coating suspension; the modified polysiloxane and carboxyl functionalized silica were mixed evenly to form a coating suspension, and the coating suspension was sprayed on the polyvinyl chloride substrate of the door sealing strip. After the solvent evaporated, transparent silicone rubber was formed, and then heated at 80°C for 40 minutes to form an easy-to-clean coating for the door sealing strip.

[0102] The performance of the easy-to-clean coatings for door sealing strips prepared in Examples 1 to 6 and Comparative Examples 1 to 4 was tested;

[0103] Among them, the test standard for easy cleaning is evaluated by testing the contact angle between the coating and water;

[0104] Among them, the test method for antibacterial performance is:

[0105] The coatings obtained from Examples 1 to 6 and Comparative Examples 1 to 4 were cut into samples of 10 mm × 10 mm and sterilized by ultraviolet irradiation for 3 h; the Escherichia coli strain was activated and prepared into a bacterial suspension with a concentration of 3 × 104 cfu / mL; the sample was placed in the bacterial suspension, shaken at 300 r / min for 5 min at room temperature, 1 mL of the bacterial suspension was diluted to 100 times, 1 mL of the diluted bacterial suspension was inoculated into an agar medium, and cultured at 37° C. for 16 h, and the colonies were counted according to the method in GB / 15979-2024, and the antibacterial rate was calculated: antibacterial rate = (average colony count before sample shaking - average colony count after sample shaking) / average colony count before sample shaking × 100%;

[0106] Among them, the test method for antifungal mycelium is:

[0107] The coatings obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were cut into 10 mm × 10 mm samples and placed in the center of a culture dish. An appropriate amount of rice sheath blight suspension was taken with a pipette and evenly dripped on the surface of the sample to ensure that the bacterial suspension covered the entire surface of the sample, as a treatment group; a blank control group without a sample block was set at the same time; a mycelium block (with a diameter of 6 mm) at the edge of the test bacterial colony was punched with a hole puncher, with the bacterial surface facing down, moved to the center of the plate, placed in a constant temperature incubator at 28°C and cultured for a certain period of time, and then the colony diameter was measured by the cross method, and the inhibition rate was calculated; each treatment was repeated 3 times; colony expansion diameter (mm) = colony average diameter (mm) - 6 mm; mycelium growth inhibition rate = (control group colony expansion diameter - treatment group colony expansion diameter) * 100% / control group colony expansion diameter;

[0108] Among them, the test method for hand feel evaluation is:

[0109] 30 experienced leather engineers conducted sensory evaluation and scoring: 20 cm long door seal strips with easy-to-clean coating were cleaned and dried at 40°C. After drying, the leather surface was gently touched to feel its feel; after being stored away from light for 7 days, 30 days and 90 days, the leather surface was touched again to feel its feel; the smoothness index of the test results was evaluated on a scale of 0-5, with high scores indicating dryness and smoothness, and low scores indicating roughness and astringency. The final data was averaged;

[0110] The performance test results are shown in Table 1.

[0111] Table 1

[0112]

[0113]

[0114] It can be seen from Table 1 that the water contact angles of the easy-to-clean coatings for door sealing strips prepared in Examples 1 to 6 are all greater than 150°, indicating that the hydrophobic effect is good and the easy-to-clean effect is excellent; and by comparing Example 1 with Comparative Examples 2 to 4, it can be seen that the addition of carboxyl-functionalized silica to produce crosslinking can significantly improve the easy-to-clean performance of the easy-to-clean coating for door sealing strips.

[0115] The antibacterial rate and antifungal rate of the easy-to-clean coating for door sealing strips prepared in Examples 1 to 6 are respectively greater than 99.83% and 30.02%, indicating that the easy-to-clean coating for door sealing strips prepared in the present invention has excellent antibacterial and anti-mildew effects; by comparing Example 1 with Comparative Examples 1 to 4, it can be found that this is because the carboxyl-functionalized silica is cross-linked to form a network, and the polymer quaternary ammonium salt formed therefrom has good antibacterial and antifungal effects, thereby enabling the easy-to-clean coating for door sealing strips to achieve the desired antibacterial and anti-mildew effects.

[0116] The hand feel evaluation of the easy-to-clean coating for door sealing strips prepared in Examples 1 to 6 is all 5, indicating that the easy-to-clean coating for door sealing strips feels smooth. Comparison between Example 1 and Comparative Example 3 to Comparative Example 4 shows that the cross-linking effect of the system caused by an appropriate amount of carboxyl-functionalized silica greatly improves the smooth effect of the easy-to-clean coating for door sealing strips.

[0117] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0118] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an easy-to-clean coating for a door sealing strip, characterized in that: The steps include: The modified polysiloxane and carboxyl functionalized silica are uniformly mixed to form a coating suspension, and then the coating suspension is coated on a door sealing strip substrate, and then heated at 80-100° C. for 10-40 minutes to form an easy-to-clean coating for the door sealing strip.

2. The method for preparing an easy-to-clean coating for a door sealing strip according to claim 1, characterized in that: The mass ratio of the modified polysiloxane to the carboxyl functionalized silica is 5:0.32-1.

6.

3. The method for preparing an easy-to-clean coating for a door sealing strip according to claim 1, characterized in that: The modified polysiloxane is prepared by the following steps: Octamethylcyclotetrasiloxane, γ-diethylenetriaminepropylmethyldimethoxysilane, dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, perfluorooctyltrimethoxysilane, hexamethyldisiloxane, tetramethylammonium hydroxide and deionized water are mixed; under N2 protection, the mixture is stirred at 90-100°C for 4-6 hours, and then the mixture is heated to 140-150°C and kept for 0.5-1 hour to obtain modified polysiloxane.

4. The method for preparing an easy-to-clean coating for a door sealing strip according to claim 3, characterized in that: The mass ratio of the octamethylcyclotetrasiloxane, γ-diethylenetriaminepropylmethyldimethoxysilane, dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, perfluorooctyltrimethoxysilane, hexamethyldisiloxane, tetramethylammonium hydroxide and deionized water is 100:9-70:0.5-0.9:0.5-0.9:0.5-0.9:0.5-0.9:1-10.

5. The method for preparing an easy-to-clean coating for a door sealing strip according to claim 1, characterized in that: The carboxyl functionalized silica is prepared by the following steps: 2-Cyanoethyltriethoxysilane is added to 30 mL of water, and after being fully dispersed, ammonia water is added, and the product is stirred at room temperature for 4-5 hours, and then centrifuged and washed with water and ethanol for 3-5 times to remove unreacted products, and then the product is placed at 60-70°C and dried for 10-12 hours to obtain a carboxyl functionalized silica intermediate; The carboxyl functionalized silica intermediate is uniformly dispersed in a sulfuric acid solution and stirred at 60-70°C for 24 hours. After the reaction is completed, the product is centrifuged and washed with water and ethanol for 3-5 times in sequence, and then the product is dried at 60-70°C for 10-12 hours to obtain carboxyl functionalized silica.

6. The method for preparing an easy-to-clean coating for a door sealing strip according to claim 5, characterized in that: The purity of 2-cyanoethyltriethoxysilane is 95%; the mass fraction of ammonia water is 25-28%; the volume ratio of 2-cyanoethyltriethoxysilane and ammonia water is 1:1; and the mass fraction of sulfuric acid solution is 30%.

7. The method for preparing an easy-to-clean coating for a door sealing strip according to claim 5, characterized in that: The usage ratio of the carboxyl functionalized silica intermediate to the sulfuric acid solution is 0.1 g:30 mL.

8. The method for preparing an easy-to-clean coating for a door sealing strip according to claim 1, characterized in that: The coating is performed by spraying or brushing.

9. The method for preparing an easy-to-clean coating for a door sealing strip according to claim 1, characterized in that: The door sealing strip substrate is made of polyvinyl chloride or thermoplastic elastomer.

10. An easy-to-clean coating for a door sealing strip, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9.

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