Film with snow melting function

Abstract

The invention discloses a thin film with a snow melting function. The thin film comprises an ETFE thin film, an electric heating coating and an insulating layer, comprising the following steps: uniformly stirring p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride, and heating for reaction to obtain an intermediate 1; mixing the intermediate 1, dichloromethane and triethylamine, slowly dropwise adding diphenyl chlorophosphate, and stirring for reaction after dropwise adding to obtain an intermediate 2; dissolving alpha, omega-bis (3-aminopropyl) polydimethylsiloxane in a dichloromethane solution, then adding a graphene oxide aqueous solution and the intermediate 2, then adding 4-dimethylaminopyridine, adding N, N-dimethylformamide after the reaction solution is clarified, and carrying out a reaction for 2-4 hours; adding N, N '-dicyclohexylcarbodiimide and N, N'-dicyclohexylcarbodiimide, heating to 25 DEG C, and reacting for 3 hours to obtain the modified silicone rubber, an electric heating coating prepared from the modified silicone rubber has uniform heat conduction and electric conduction performance and also has good flame-retardant and oxidation-resistant performance, the snow melting efficiency is greatly improved, and the service life of the electric heating coating is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of snow melting, and in particular to a film with snow melting function. Background Art

[0002] ETFE film is a high-strength, high-weather-resistant film made by extruding ETFE (ethylene-tetrafluoroethylene copolymer) raw materials. It is widely used in membrane structure buildings. ETFE film is widely used in the construction industry due to its excellent properties such as light weight, light transmission, heat insulation, corrosion resistance, weather resistance, and self-cleaning. In the cold northern regions, snow easily accumulates on the surface of ETFE film after snowfall in winter. Because the uneven surface and low strength of membrane structure buildings make it difficult to clean up the snow, it is necessary to develop an ETFE film material with snow melting function so that the snow can be quickly cleaned to ensure the safety and lighting of the building;

[0003] There are two existing ways to clear snow: manual cleaning: structures with flat surfaces can be cleaned manually on the roof, but this cleaning method has certain risks and is difficult and labor-intensive to clean; electric heating cleaning: adding a heating wire at the bottom of the film to heat the film to melt the snow for cleaning, but this method is costly and the heating wire is easily broken during operation;

[0004] Its existing patent CN 114806291 A also discloses a three-dimensional heat-conductive anti-icing electric heating coating based on in-situ growth and a preparation method thereof, wherein triethanolamine is used as a stripping aid to strip boron nitride into boron nitride nanosheets, and then the boron nitride nanosheets are used as a template and tetraethyl orthosilicate is used as a silicon source to in-situ grow silicon dioxide at the edge of the boron nitride nanosheets to obtain a composite nanofiller; the composite nanofiller is filled in a polytetrafluoroethylene coating, so that silicon dioxide connects the boron nitride nanosheets and forms a three-dimensional heat-conductive network, and then the anti-icing electric heating coating is sprayed on the surface of an aluminum plate to obtain the anti-icing electric heating coating; the anti-icing electric heating coating can effectively overcome the above-mentioned problems of manual cleaning and electric heating cleaning, but the electric heating coating has poor performance in anti-aging, flame retardancy and other properties, which will affect the use efficiency and safety of the electric heating coating. Summary of the invention

[0005] The purpose of the present invention is to provide a film with snow melting function to solve the following technical problems:

[0006] Although the anti-icing electric heating coating can effectively overcome the above-mentioned problems of manual cleaning and electric heating cleaning, the electric heating coating has poor performance in anti-aging and flame retardant properties, which will affect the use efficiency and safety of the electric heating coating.

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

[0008] A film with snow melting function, comprising: an ETFE film, an electric heating coating and an insulating layer; the electric heating coating is printed on the surface of the ETFE film, and the insulating layer is coated on the surface of the electric heating coating;

[0009] The electric heating coating is composed of modified silicone rubber and diluent;

[0010] The preparation process of modified silicone rubber comprises the following steps:

[0011] Step 1: After stirring p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride, heat to 113°C and react at this temperature for 2 hours, then heat the reaction system to 152°C and continue the reaction at this temperature for 1.5 hours. After the reaction is completed, intermediate 1 is obtained;

[0012] Step 2: Mix the intermediate 1, dichloromethane and triethylamine, stir and cool to 0°C under nitrogen protection, slowly drop a dichloromethane solution of diphenyl chlorophosphate, and after the addition is completed, keep the temperature unchanged and continue stirring the reaction for 24 hours to obtain the intermediate 2;

[0013] Step 3: First prepare a 0.1 mol / L NaOH aqueous solution, adjust the graphene oxide aqueous solution to make it weakly alkaline, and obtain a graphene oxide solution with a concentration of 1 mg / mL;

[0014] α,ω-bis(3-aminopropyl)polydimethylsiloxane was dissolved in dichloromethane solution, and then graphene oxide aqueous solution and intermediate 2 were added, followed by 4-dimethylaminopyridine. After the reaction solution was clarified, N,N'-dicyclohexylcarbodiimide was added, the temperature was raised to 25°C, and the reaction was carried out for 3 hours to obtain modified silicone rubber.

[0015] As a further solution of the present invention: the mass ratio of the modified silicone rubber to the diluent is 1-2:10-50.

[0016] As a further solution of the present invention: the dosage ratio of p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride is controlled to be 0.1 mol: 0.21-0.23 mol: 4-6 mol.

[0017] As a further solution of the present invention: the dosage ratio of the intermediate 1, dichloromethane, triethylamine and diphenyl chlorophosphate dichloromethane solution is controlled to be 2-5 g:10 mL:2.1 g:30 mL.

[0018] As a further solution of the present invention: the dichloromethane solution of diphenyl chlorophosphate is prepared by mixing diphenyl chlorophosphate and dichloromethane at a ratio of 1 g:10 mL.

[0019] As a further solution of the present invention: the weight ratio of the graphene oxide solution with a concentration of 1 mg / mL, α,ω-bis(3-aminopropyl)polydimethylsiloxane, the intermediate 2,4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is controlled to be 2:1-5:0.01:0.5-2.

[0020] As a further embodiment of the present invention: the diluent includes one or a mixture of several of acetone, ethanol, ethyl acetate, isopropanol, n-hexane, n-butanol and ethyl acetate.

[0021] As a further solution of the present invention: the preparation process of the film comprises the following steps:

[0022] ETFE film is surface treated;

[0023] Prepare an electric heating coating, which is composed of modified silicone rubber and a diluent, and the mass ratio of the modified silicone rubber to the diluent is 1-2:10-50;

[0024] Coating printing, the electric heating coating is directly printed on the surface of the ETFE film to form a heating layer.

[0025] As a further solution of the present invention: coating an insulating layer, the printed electric heating ETFE film needs to be coated with an insulating layer on the surface.

[0026] Beneficial effects of the present invention:

[0027] The silicone rubber of the present invention is prepared by using p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride to obtain an intermediate 1 containing amino groups and capable of generating free radicals with anti-aging properties. The intermediate 1, dichloromethane, triethylamine and diphenyl chlorophosphate are used to prepare a phosphorus-containing monomer, which can generate phosphorus oxygen free radicals during pyrolysis and can combine with active H· and OH· free radicals in flames to terminate the combustion reaction. Therefore, the intermediate 2 obtained by the present invention has not only anti-aging properties but also flame retardant properties. Then, a graphene oxide solution, α, ω-bis(3 -aminopropyl) polydimethylsiloxane and intermediate 2 are used to prepare modified silicone rubber, so that the modified silicone rubber is connected with graphene with high thermal conductivity and electrical conductivity and intermediate 2 with anti-aging and flame retardant properties, so that the graphene is evenly dispersed on the silicone rubber, and the graphene can improve the strength of the silicone rubber, effectively improving the strength of the electric heating coating at low temperatures; therefore, the electric heating coating prepared from the modified silicone rubber of the present invention has uniform thermal and electrical conductivity, and also has good flame retardant and antioxidant properties, which greatly improves the snow melting efficiency and increases its service life. DETAILED DESCRIPTION

[0028] 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.

[0029] Example 1

[0030] The present invention is a film with snow melting function, comprising: an ETFE film, an electric heating coating and an insulating layer;

[0031] By printing a coating with electric heating function on the surface of ETFE film, the ETFE film is heated by electric heating. Because the electric heating coating is directly printed on the ETFE film, good heat conduction is ensured, which greatly improves the efficiency of ETFE snow melting.

[0032] The preparation process of the film with snow melting function comprises the following steps:

[0033] Step 1: ETFE film is surface treated to improve the bonding strength between the film and the coating;

[0034] Step 2: preparing an electric heating coating, which is composed of modified silicone rubber and a diluent, wherein the mass ratio of the modified silicone rubber to the diluent is 1:10; the diluent includes one or a mixture of acetone, ethanol, ethyl acetate, isopropanol, n-hexane, n-butanol, and ethyl acetate;

[0035] Step 3: Coating printing: the electric heating coating is directly printed on the surface heating layer of the ETFE film;

[0036] Step 4: Apply an insulating layer. The printed electric heating ETFE film needs to be coated with an insulating layer on the surface to ensure safety during operation.

[0037] Specifically, the preparation process of the modified silicone rubber comprises the following steps:

[0038] Step 1: After stirring p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride, heat to 113°C and react at a constant temperature for 2h, then heat the reaction system to 152°C and continue the constant temperature reaction for 1.5h. After the reaction is completed, when the system drops to 55°C, distill under reduced pressure for 30min, then add 2mol / L dilute hydrochloric acid to dissolve the remaining substance, filter, take the filtrate and neutralize it with 2mol / L dilute sodium hydroxide solution to pH 7-8, then a precipitate is generated, filter after the precipitation is complete, take the filter cake and wash it repeatedly for 3-5 times, and the crude product is recrystallized twice with ethanol / water, and finally dried in vacuo at 60°C for 24h to obtain intermediate 1;

[0039] The dosage ratio of p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride is controlled to be 0.1 mol: 0.21 mol: 4 mol;

[0040] Step 2: Mix the intermediate 1, dichloromethane and triethylamine, stir and cool to 0°C under nitrogen protection, slowly drop a dichloromethane solution of diphenyl chlorophosphate, keep the temperature unchanged after the dropwise addition, continue stirring and reacting for 24 hours, and perform post-treatment after the reaction. The post-treatment process is as follows: wash the obtained reaction solution with deionized water, 5% sodium hydroxide solution and deionized water in sequence, dry the obtained organic phase with anhydrous sodium sulfate, and remove the solvent by rotary evaporation after drying to obtain the intermediate 2;

[0041] The amount ratio of the intermediate 1, dichloromethane, triethylamine and diphenyl chlorophosphate dichloromethane solution is controlled to be 2g:10mL:2.1g:30mL, wherein the diphenyl chlorophosphate dichloromethane solution is a mixture of diphenyl chlorophosphate and dichloromethane at a ratio of 1g:10mL;

[0042] Step 3: First prepare a 0.1 mol / L NaOH aqueous solution, adjust the graphene oxide aqueous solution to make it weakly alkaline, and obtain a graphene oxide solution with a concentration of 1 mg / mL, so that the oxygen-containing groups on the surface of the graphene oxide are reacted;

[0043] α,ω-bis(3-aminopropyl)polydimethylsiloxane was dissolved in a dichloromethane solution, and then a graphene oxide aqueous solution and intermediate 2 were added, followed by 4-dimethylaminopyridine. After the reaction solution was clarified, N,N'-dicyclohexylcarbodiimide was added, and the temperature was raised to 25°C. After reacting for 3 hours, the solution was quickly poured into a mixed solvent (mixed with deionized water and methanol) for flocculation, and washed repeatedly three times, and vacuum dried to obtain a modified silicone rubber;

[0044] Among them, the weight ratio of graphene oxide solution with a controlled concentration of 1 mg / mL, α,ω-bis(3-aminopropyl)polydimethylsiloxane, intermediate 2,4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is 2:1:0.01:0.5.

[0045] Example 2

[0046] The difference from Example 1 is that:

[0047] The preparation process of the film with snow melting function comprises the following steps:

[0048] Step 1: ETFE film is surface treated to improve the bonding strength between the film and the coating;

[0049] Step 2: preparing an electric heating coating, which is composed of modified silicone rubber and a diluent, wherein the mass ratio of the modified silicone rubber to the diluent is 1.5:30; the diluent includes one or a mixture of acetone, ethanol, ethyl acetate, isopropanol, n-hexane, n-butanol, and ethyl acetate;

[0050] Step 3: Coating printing: the electric heating coating is directly printed on the surface heating layer of the ETFE film;

[0051] Step 4: Apply an insulating layer. The printed electric heating ETFE film needs to be coated with an insulating layer on the surface to ensure safety during operation.

[0052] Specifically, the preparation process of the modified silicone rubber comprises the following steps:

[0053] Step 1: After stirring p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride, heat to 113°C and react at a constant temperature for 2h, then heat the reaction system to 152°C and continue the constant temperature reaction for 1.5h. After the reaction is completed, when the system drops to 55°C, distill under reduced pressure for 30min, then add 2mol / L dilute hydrochloric acid to dissolve the remaining substance, filter, take the filtrate and neutralize it with 2mol / L dilute sodium hydroxide solution to pH 7-8, then a precipitate is generated, filter after the precipitation is complete, take the filter cake and wash it repeatedly for 3-5 times, and the crude product is recrystallized twice with ethanol / water, and finally dried in vacuo at 60°C for 24h to obtain intermediate 1;

[0054] The dosage ratio of p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride is controlled to be 0.1 mol: 0.212 mol: 5 mol;

[0055] Step 2: Mix the intermediate 1, dichloromethane and triethylamine, stir and cool to 0°C under nitrogen protection, slowly drop a dichloromethane solution of diphenyl chlorophosphate, keep the temperature unchanged after the dropwise addition, continue stirring and reacting for 24 hours, and perform post-treatment after the reaction. The post-treatment process is as follows: wash the obtained reaction solution with deionized water, 5% sodium hydroxide solution and deionized water in sequence, dry the obtained organic phase with anhydrous sodium sulfate, and remove the solvent by rotary evaporation after drying to obtain the intermediate 2;

[0056] The amount ratio of the intermediate 1, dichloromethane, triethylamine and diphenyl chlorophosphate dichloromethane solution is controlled to be 4g:10mL:2.1g:30mL, wherein the diphenyl chlorophosphate dichloromethane solution is a mixture of diphenyl chlorophosphate and dichloromethane at a ratio of 1g:10mL;

[0057] Step 3: First prepare a 0.1 mol / L NaOH aqueous solution, adjust the graphene oxide aqueous solution to make it weakly alkaline, and obtain a graphene oxide solution with a concentration of 1 mg / mL, so that the oxygen-containing groups on the surface of the graphene oxide are reacted;

[0058] α,ω-bis(3-aminopropyl)polydimethylsiloxane was dissolved in a dichloromethane solution, and then a graphene oxide aqueous solution and intermediate 2 were added, followed by 4-dimethylaminopyridine. After the reaction solution was clarified, N,N'-dicyclohexylcarbodiimide was added, and the temperature was raised to 25°C. After reacting for 3 hours, the solution was quickly poured into a mixed solvent (mixed with deionized water and methanol) for flocculation, and washed repeatedly three times, and vacuum dried to obtain a modified silicone rubber;

[0059] Among them, the weight ratio of graphene oxide solution with a controlled concentration of 1 mg / mL, α,ω-bis(3-aminopropyl)polydimethylsiloxane, intermediate 2,4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is 2:3:0.01:1.2.

[0060] Example 3

[0061] The preparation process of the film with snow melting function comprises the following steps:

[0062] Step 1: ETFE film is surface treated to improve the bonding strength between the film and the coating;

[0063] Step 2: preparing an electric heating coating, which is composed of modified silicone rubber and a diluent, wherein the mass ratio of the modified silicone rubber to the diluent is 2:50; the diluent includes one or a mixture of several of acetone, ethanol, ethyl acetate, isopropanol, n-hexane, n-butanol, and ethyl acetate;

[0064] Step 3: Coating printing: the electric heating coating is directly printed on the surface heating layer of the ETFE film;

[0065] Step 4: Apply an insulating layer. The printed electric heating ETFE film needs to be coated with an insulating layer on the surface to ensure safety during operation.

[0066] Specifically, the preparation process of the modified silicone rubber comprises the following steps:

[0067] Step 1: After stirring p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride, heat to 113°C and react at a constant temperature for 2h, then heat the reaction system to 152°C and continue the constant temperature reaction for 1.5h. After the reaction is completed, when the system drops to 55°C, distill under reduced pressure for 30min, then add 2mol / L dilute hydrochloric acid to dissolve the remaining substance, filter, take the filtrate and neutralize it with 2mol / L dilute sodium hydroxide solution to pH 7-8, then a precipitate is generated, filter after the precipitation is complete, take the filter cake and wash it repeatedly for 3-5 times, and the crude product is recrystallized twice with ethanol / water, and finally dried in vacuo at 60°C for 24h to obtain intermediate 1;

[0068] The dosage ratio of p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride is controlled to be 0.1 mol: 0.23 mol: 6 mol;

[0069] Step 2: Mix the intermediate 1, dichloromethane and triethylamine, stir and cool to 0°C under nitrogen protection, slowly drop a dichloromethane solution of diphenyl chlorophosphate, keep the temperature unchanged after the dropwise addition, continue stirring and reacting for 24 hours, and perform post-treatment after the reaction. The post-treatment process is as follows: wash the obtained reaction solution with deionized water, 5% sodium hydroxide solution and deionized water in sequence, dry the obtained organic phase with anhydrous sodium sulfate, and remove the solvent by rotary evaporation after drying to obtain the intermediate 2;

[0070] The amount ratio of the intermediate 1, dichloromethane, triethylamine and diphenyl chlorophosphate dichloromethane solution is controlled to be 5g:10mL:2.1g:30mL, wherein the diphenyl chlorophosphate dichloromethane solution is a mixture of diphenyl chlorophosphate and dichloromethane at a ratio of 1g:10mL;

[0071] Step 3: First prepare a 0.1 mol / L NaOH aqueous solution, adjust the graphene oxide aqueous solution to make it weakly alkaline, and obtain a graphene oxide solution with a concentration of 1 mg / mL, so that the oxygen-containing groups on the surface of the graphene oxide are reacted;

[0072] α,ω-bis(3-aminopropyl)polydimethylsiloxane was dissolved in a dichloromethane solution, and then a graphene oxide aqueous solution and intermediate 2 were added, followed by 4-dimethylaminopyridine. After the reaction solution was clarified, N,N'-dicyclohexylcarbodiimide was added, and the temperature was raised to 25°C. After reacting for 3 hours, the solution was quickly poured into a mixed solvent (mixed with deionized water and methanol) for flocculation, and washed repeatedly three times, and vacuum dried to obtain a modified silicone rubber;

[0073] Among them, the weight ratio of graphene oxide solution with a controlled concentration of 1 mg / mL, α,ω-bis(3-aminopropyl)polydimethylsiloxane, intermediate 2,4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is 2:5:0.01:2.

[0074] Comparative Example 1

[0075] Comparative Example 1 Compared with Example 1, silicone rubber is used instead of modified silicone rubber to prepare the electric heating coating;

[0076] Performance Testing:

[0077] The electric heating coatings of Examples 1-3 and Comparative Example 1 were tested. After the electric heating coatings were adjusted to 120°C in the aging box, the test specimens were placed in the aging box for experiment. After 72 hours, the samples were taken out and the electric thermal conductivity of the electric heating coatings of Examples 1-3 and Comparative Example 1 was tested. The test results are as follows: Thermal conductivity W / (m·K) Example 1 1.8 Example 2 1.9 Example 3 1.7 Comparative Example 1 0.1

[0078] It can be seen from the above table that the modified silicone rubber prepared in the present invention still has good electrical and thermal conductivity after long-term aging.

[0079] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A film with snow melting function, characterized in that: include: ETFE film, electric heating coating and insulation layer; An electric heating coating is printed on the surface of the ETFE film, and an insulating layer is coated on the surface of the electric heating coating; The electric heating coating is composed of modified silicone rubber and diluent; The preparation process of modified silicone rubber comprises the following steps: Step 1: After stirring p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride, heat to 113°C and react at this temperature for 2 hours, then heat the reaction system to 152°C and continue the reaction at this temperature for 1.5 hours. After the reaction is completed, intermediate 1 is obtained; Step 2: Mix the intermediate 1, dichloromethane and triethylamine, stir and cool to 0°C under nitrogen protection, slowly drop a dichloromethane solution of diphenyl chlorophosphate, and after the addition is completed, keep the temperature unchanged and continue stirring the reaction for 24 hours to obtain the intermediate 2; Step 3: First prepare a 0.1 mol / L NaOH aqueous solution, adjust the graphene oxide aqueous solution to make it weakly alkaline, and obtain a graphene oxide solution with a concentration of 1 mg / mL; α,ω-bis(3-aminopropyl)polydimethylsiloxane was dissolved in dichloromethane solution, and then graphene oxide aqueous solution and intermediate 2 were added, followed by 4-dimethylaminopyridine. After the reaction solution was clarified, N,N'-dicyclohexylcarbodiimide was added, the temperature was raised to 25°C, and the reaction was carried out for 3 hours to obtain modified silicone rubber.

2. The film with snow-melting function according to claim 1, characterized in that: The mass ratio of modified silicone rubber to diluent is 1-2:10-50.

3. The film with snow-melting function according to claim 1, characterized in that: The dosage ratio of p-hydroxymethylbenzaldehyde, aniline and aniline hydrochloride is controlled to be 0.1 mol: 0.21-0.23 mol: 4-6 mol.

4. The film with snow-melting function according to claim 1, characterized in that: The dosage ratio of intermediate 1, dichloromethane, triethylamine and diphenyl chlorophosphate dichloromethane solution is controlled to be 2-5 g:10 mL:2.1 g:30 mL.

5. The film with snow-melting function according to claim 1, characterized in that: The dichloromethane solution of diphenyl chlorophosphate is prepared by mixing diphenyl chlorophosphate and dichloromethane in a ratio of 1 g:10 mL.

6. The film with snow-melting function according to claim 1, characterized in that: The weight ratio of graphene oxide solution with a concentration of 1 mg / mL, α,ω-bis(3-aminopropyl)polydimethylsiloxane, intermediate 2,4-dimethylaminopyridine and N,N'-dicyclohexylcarbodiimide is controlled to be 2:1-5:0.01:0.5-2.

7. The film with snow-melting function according to claim 1, characterized in that: The diluent includes one or a mixture of acetone, ethanol, ethyl acetate, isopropanol, n-hexane, n-butanol, and ethyl acetate.

8. The film with snow-melting function according to claim 1, characterized in that: The preparation process of the film comprises the following steps: ETFE film is surface treated; Prepare an electric heating coating, which is composed of modified silicone rubber and a diluent, and the mass ratio of the modified silicone rubber to the diluent is 1-2:10-50; Coating printing, the electric heating coating is directly printed on the surface of the ETFE film to form a heating layer.

9. The film with snow-melting function according to claim 8, characterized in that: Coating an insulating layer: coating an insulating layer on the surface of the printed electric heating ETFE film.