Graphene-containing far-infrared warm-keeping polyurethane transfer film and preparation method thereof

Abstract

The invention relates to the technical field of transfer films, in particular to a graphene-containing far-infrared warm-keeping polyurethane transfer film and a preparation method thereof. The far-infrared warm-keeping polyurethane transfer film containing graphene comprises a three-layer structure including a supporting layer, a polyurethane transfer layer and a bonding layer, the polyurethane transfer layer is located on one side of the supporting layer, and the bonding layer is located on the other side of the polyurethane transfer layer; the polyurethane transfer layer is prepared from polyurethane resin, an organic solvent, an organic pigment and a composite modifier, the composite modifier is prepared from alkenyl modified graphene oxide, chloropropenyl modified hindered phenol and 4-allyloxy-2-hydroxybenzophenone, and the composite modifier is added, so that the polyurethane transfer layer is formed. The polyurethane transfer film has far infrared thermal insulation performance and good oxidation resistance and hydrolysis resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transfer film, in particular to a far-infrared thermal polyurethane transfer film containing graphene and a preparation method thereof. BACKGROUND

[0002] Although the dermal fabric has the characteristics of air permeability, softness and warmth, it has the shortcomings of high raw material cost and high price. As a kind of imitation leather material, polyurethane synthetic leather can approach the texture of real leather and replace the dermal fabric to a great extent, especially the microfiber leather, which is widely used. The microfiber leather is made of leather base cloth made of polyester or nylon superfine fiber and polyurethane, which has the characteristics of soft and delicate hand feeling, wear resistance and the like. At present, the production process of polyurethane synthetic leather mainly includes wet-dry process and full dry process. However, the wet-dry process has a long process, and the full dry process refers to the process of directly bonding and drying on the release paper to form the finished product, which has a short process flow.

[0003] The polyurethane resin includes polyether polyurethane and polyester polyurethane. The polyether polyurethane has good wear resistance and flexibility, and the polyester polyurethane has good mechanical strength. By using the two kinds of resins together, the comprehensive performance of the material can be improved. For example, Chinese patent CN 101204867B discloses a manufacturing method of PU transfer film. The plain oxford cloth is only used as a carrier. The wet polyurethane coating is coated on the plain oxford cloth, and then the PU dry transfer coating with leather pattern is compounded on the wet polyurethane coating. Finally, the PU transfer film is obtained by peeling off the plain oxford cloth. The wet slurry process formula includes polyurethane resin, DMF, solvent type colorant and wood powder. The dry slurry process formula includes polyurethane resin, solvent, colorant and leveling agent. The polyurethane resin includes polyester polyurethane resin and polyether polyurethane resin. However, the polyurethane material is prone to oxidation and cracking when exposed to air for a long time. The organic pigment is prone to discoloration under ultraviolet irradiation. In addition, the water resistance of the polyester polyurethane needs to be improved. SUMMARY

[0004] In view of the shortcomings of the prior art, the present application provides a far-infrared thermal polyurethane transfer film containing graphene and a preparation method, which solves the problem that the oxidation resistance and water resistance of the polyurethane-based material need to be improved in the prior art.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: A far-infrared thermal polyurethane transfer film containing graphene, comprising a support layer, a polyurethane transfer layer and a bonding layer, the polyurethane transfer layer is located on one side of the support layer, and the bonding layer is located on the other side of the polyurethane transfer layer. The support layer comprises a PET release film layer. The adhesive layer comprises a hot melt adhesive film layer; The raw materials for preparing the polyurethane transfer layer comprise a polyurethane resin, an organic solvent, an organic pigment and a composite modifier; The composite modifier is prepared by the following steps: S1, preparing alkenyl-modified graphene oxide and chloro-propenyl-modified hindered phenol; Preparation of the alkenyl-modified graphene oxide comprises: Carboxylated graphene oxide is reacted with γ-methacryloxypropyltrimethoxysilane to obtain the alkenyl-modified graphene oxide; Preparation of the chloro-propenyl-modified hindered phenol comprises: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine is reacted with 2-chloro-propenyl isothiocyanate to obtain the chloro-propenyl-modified hindered phenol; S2, the alkenyl-modified graphene oxide, the chloro-propenyl-modified hindered phenol and 4-propenyloxy-2-hydroxybenzophenone are reacted to prepare the composite modifier.

[0006] Preferably, the mass ratio of the polyurethane resin, the organic solvent, the organic pigment and the composite modifier is 100:(35-45):(2-3):(4-8); The polyurethane resin comprises a polyether type polyurethane resin and a polyester type polyurethane resin; The mass ratio of the polyether type polyurethane resin and the polyester type polyurethane resin is (0.5-2):1; The organic solvent comprises N,N-dimethylformamide (DMF).

[0007] Preferably, in S1, the alkenyl-modified graphene oxide is prepared by specifically comprising: Carboxylated graphene oxide is added into ethanol, ultrasonically dispersed, the pH value is adjusted to 5-6, and then γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is added dropwise, after the dropwise addition is completed, reaction is carried out, after the reaction is completed, filtration, washing and drying are carried out to obtain the alkenyl-modified graphene oxide; The mass ratio of the carboxylated graphene oxide, the ethanol and the γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is 1:(50-60):(80-120), and the reaction is carried out at a temperature of 50-70℃ for 20-30h.

[0008] Preferably, the γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is prepared by mixing γ-methacryloxypropyltrimethoxysilane (KH-570) with 95wt% ethanol aqueous solution, and the concentration of the γ-methacryloxypropyltrimethoxysilane is 25-35g / L.

[0009] Preferably, the carboxylated graphene oxide is prepared by the following steps: The graphene oxide is dispersed in deionized water, ultrasonic dispersion to obtain a graphene oxide dispersion, and then sodium hydroxide and monochloroacetic acid are added to the graphene oxide dispersion to react. The mass ratio of graphene oxide, deionized water, sodium hydroxide, and monochloroacetic acid is 0.1:(80-120):(5.5-6.5):(4.5-5.5), and the reaction conditions are ultrasonic reaction at a frequency of 60-80 kHz for 2.5-3.5 h.

[0010] Preferably, in S1, the chloro-propenyl-modified hindered phenol is prepared, specifically including: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine and 2-chloro-propenyl isothiocyanate are added to ethanol to react. The mass ratio of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine, 2-chloro-propenyl isothiocyanate, and ethanol is 29.2:(14-16):(400-600), and the reaction conditions are refluxing at a temperature of 85-95℃ for 4-5 h. The sulfur-modified hindered phenol, mercuric oxide, chloroform, and deionized water are mixed to react. The mass ratio of sulfur-modified hindered phenol, mercuric oxide, chloroform, and deionized water is 4.3:(8.2-8.5):(205-220):(135-145), and the reaction conditions are stirring at room temperature for 45-50 h.

[0011] Preferably, in S2, the composite modifier is prepared, specifically including: 4-propenyl-2-hydroxybenzophenone is added to toluene and stirred until dissolved to obtain a 4-propenyl-2-hydroxybenzophenone solution; benzoyl peroxide, alkenyl-modified graphene oxide, and chloro-propenyl-modified hindered phenol are added to the 4-propenyl-2-hydroxybenzophenone solution, and after stirring and dispersing, the temperature is raised to a set temperature to react. The mass ratio of 4-propenyl-2-hydroxybenzophenone, toluene, benzoyl peroxide, alkenyl-modified graphene oxide, and chloro-propenyl-modified hindered phenol is (50.8-55):(800-1000):(1.8-4.2):(48-52):(42.6-44), and the reaction conditions are reaction at a set temperature for 1-2 h. The set temperature is 90-100℃.

[0012] The application further discloses a preparation method of the graphene-containing far-infrared thermal polyurethane transfer film. Step (1), dissolving polyurethane resin in an organic solvent, adding organic pigments and a composite modifier, stirring and mixing to obtain a slurry; coating the slurry on the surface of a support layer, and performing solidification, water washing and drying to form a polyurethane transfer layer; Step (2), bonding a hot melt adhesive film on the surface of the polyurethane transfer layer, and performing pressing and cooling to form a bonding layer, thereby obtaining the graphene-containing far-infrared thermal polyurethane transfer film. The graphene-containing far-infrared thermal polyurethane transfer film comprises a support layer, a polyurethane transfer layer and a bonding layer, the support layer is a PET release film layer, and the bonding layer is a hot melt adhesive film layer.

[0013] Preferably, in the step (1), the coating amount of the slurry is 180-240 g / m 2 The solidification condition is 15-20 min of solidification at room temperature in a 16wt%-20wt% N,N-dimethylformamide aqueous solution, the water washing condition is water washing at a temperature of 60-80 ℃, the slurry is extruded once every 5 min during the water washing process, and the extrusion is performed 5-10 times, and the drying condition is 10-20 min of drying at 100-120 ℃.

[0014] Preferably, in the step (2), the thickness of the hot melt adhesive film is 0.1-0.2 mm, the softening point of the hot melt adhesive film is 120-130 ℃, and the pressing pressure is 4-6 MPa.

[0015] Compared with the prior art, the application has the following beneficial effects: In the application, the polyether type polyurethane and the polyester type polyurethane are used in combination, so that the excellent wear resistance and flexibility of the polyether type polyurethane and the high mechanical strength of the polyester type polyurethane can be combined, and the comprehensive performance of the polyurethane transfer film is good. The composite modifier prepared by using graphene oxide, hindered phenolic antioxidant and ultraviolet absorber as raw materials can effectively improve the far infrared warming, anti-aging and anti-ultraviolet properties of the polyurethane transfer film. In the preparation of the composite modifier, the graphene oxide is reacted with silane coupling agent γ-methacryloxypropyl trimethoxysilane to obtain alkenyl-modified graphene oxide, the hindered phenolic antioxidant 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl hydrazine is reacted with 2-chloroallyl isothiocyanate to obtain chloroallyl-modified hindered phenol, and the alkenyl-modified graphene oxide, the chloroallyl-modified hindered phenol and 4-propyleneoxy-2-hydroxybenzophenone are reacted under the action of an initiator to form a polymer, realizing the chemical bonding between the functional components and improving the compatibility and dispersion uniformity of the functional components and the base resin. Meanwhile, the migration of small molecule functional components can be prevented. In the process of modifying the hindered phenolic antioxidant 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl hydrazine to introduce alkenyl groups, the hydrazine group is bonded with the isothiocyanate group to generate a carbodiimide group, which has excellent hydrolysis resistance and can effectively improve the hydrolysis resistance of the polyester polyurethane. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The structure of the far infrared warming polyurethane transfer film containing graphene prepared in the present application is shown in the figure. In the figure, 1 is a support layer, 2 is a polyurethane transfer layer, and 3 is an adhesive layer. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0018] Embodiment 1

[0019] The present embodiment discloses a preparation method of a far infrared warming polyurethane transfer film containing graphene, which comprises the following steps: Step (1), dissolving polyether polyurethane resin and polyester polyurethane resin in N,N-dimethylformamide, adding organic pigment permanent yellow GG and composite modifier, stirring and mixing to obtain a slurry; The mass ratio of the polyether polyurethane resin, the polyester polyurethane resin, the N,N-dimethylformamide, the organic pigment permanent yellow GG and the composite modifier is 50:50:35:2:4. The composite modifier is prepared by the following steps: S1, preparing alkenyl-modified graphene oxide and chloro-propenyl-modified hindered phenol; Preparation of the alkenyl-modified graphene oxide comprises: The graphene oxide is dispersed in deionized water and ultrasonically dispersed for 30 min at a frequency of 50 kHz to obtain a graphene oxide dispersion liquid. Sodium hydroxide and monochloroacetic acid are added to the graphene oxide dispersion liquid. The mass ratio of graphene oxide, deionized water, sodium hydroxide, and monochloroacetic acid is 0.1:80:5.5:4.5. Ultrasonic reaction is performed for 3.5 h at a frequency of 60 kHz. After the reaction is completed, filtration is performed, washing with deionized water is performed for 3 times, and drying is performed in a vacuum drying box at 50°C for 24 h to obtain carboxylated graphene oxide. The carboxylated graphene oxide is added to ethanol and ultrasonically dispersed for 30 min at a frequency of 50 kHz. The pH value is adjusted to 5 using 1 mol / L hydrochloric acid. A γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is added dropwise. The mass ratio of carboxylated graphene oxide, ethanol, and the γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is 1:50:80. After dropwise addition is completed, reaction is performed for 30 h at a temperature of 50°C. After the reaction is completed, filtration is performed, washing with ethanol is performed for 3 times, and drying is performed in a vacuum drying box at 50°C for 12 h to obtain alkenyl-modified graphene oxide. The γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is prepared by mixing γ-methacryloxypropyltrimethoxysilane with 95 wt% ethanol aqueous solution. The concentration of γ-methacryloxypropyltrimethoxysilane is 35 g / L. Preparation of the chloro-propenyl-modified hindered phenol comprises: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine and 2-chloro-propenyl isothiocyanate are added to ethanol. The mass ratio of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine, 2-chloro-propenyl isothiocyanate, and ethanol is 29.2:14:400. Reflux reaction is performed for 5 h at a temperature of 85°C. After the reaction is completed, cooling is performed to room temperature. Filtration is performed. Recrystallization is performed using a mixed solvent of chloroform and petroleum ether to obtain a thiourea-modified hindered phenol. The thiourea-modified hindered phenol, mercury oxide, trichloromethane, and deionized water are mixed. The mass ratio of the thiourea-modified hindered phenol, mercury oxide, trichloromethane, and deionized water is 4.3:8.2:205:135. Stirring reaction is performed for 45 h at room temperature. After the reaction is completed, the trichloromethane layer becomes black. Filtration is performed until the filtrate becomes clear. Drying is performed using CaCl2 for 2 h. Filtration is performed. The solvent is removed under reduced pressure. Recrystallization is performed using ethyl acetate. Drying is performed in a vacuum drying box at 50°C for 12 h to obtain a chloro-propenyl-modified hindered phenol. S2, 4-propenyl oxy-2-hydroxybenzophenone is added into toluene and stirred until dissolved to obtain a 4-propenyl oxy-2-hydroxybenzophenone solution; benzoyl peroxide, alkenyl-modified graphene oxide, chloro-propenyl-modified hindered phenol are added into the 4-propenyl oxy-2-hydroxybenzophenone solution, the mass ratio of 4-propenyl oxy-2-hydroxybenzophenone, toluene, benzoyl peroxide, alkenyl-modified graphene oxide, chloro-propenyl-modified hindered phenol is 50.8:800:1.8:48:42.6, after stirring and dispersing, the temperature is raised to 90℃, and the reaction is carried out at 90℃ for 2h, after the reaction is completed, toluene is removed by rotary evaporation at 75℃, the product after rotary evaporation is washed with ethanol for 3 times, and is placed in a 50℃ vacuum drying oven for drying for 12h to obtain a composite modifier; The slurry is coated on the surface of the PET release film, and a polyurethane transfer layer is formed through solidification, water washing and drying; The coating amount of the slurry is 200g / m 2 The solidification condition is solidification in 18wt% N,N-dimethylformamide aqueous solution at room temperature for 20min, the water washing condition is water washing at a temperature of 70℃, the water washing process is extruded once every 5min, and the extrusion is performed 10 times, and the drying condition is drying at 110℃ for 15min.

[0020] Step (2), a hot melt adhesive film is attached to the surface of the polyurethane transfer layer, and a bonding layer is formed through pressing and cooling to obtain a far infrared thermal polyurethane transfer film containing graphene; The thickness of the hot melt adhesive film is 0.15mm, the softening point of the hot melt adhesive film is 126℃, and the pressing pressure is 5MPa. The far infrared thermal polyurethane transfer film containing graphene comprises a support layer, a polyurethane transfer layer and a bonding layer, the support layer is a PET release film layer, and the bonding layer is a hot melt adhesive film layer.

[0021] Example 2

[0022] The embodiment discloses a preparation method of a far infrared thermal polyurethane transfer film containing graphene, and comprises the following steps: Step (1), polyether type polyurethane resin and polyester type polyurethane resin are dissolved in N,N-dimethylformamide, organic pigment permanent yellow GG and a composite modifier are added, and stirring and mixing are performed to obtain a slurry; The mass ratio of the polyether type polyurethane resin, the polyester type polyurethane resin, N,N-dimethylformamide, the organic pigment permanent yellow GG and the composite modifier is 50:50:3:8. The composite modifier is prepared by the following steps: S1, alkenyl-modified graphene oxide and chloro-propenyl-modified hindered phenol are prepared; Preparation of the alkenyl-modified graphene oxide includes: The graphene oxide was dispersed in deionized water and ultrasonically dispersed for 30 min at a frequency of 50 kHz to obtain a graphene oxide dispersion. Sodium hydroxide and monochloroacetic acid were added to the graphene oxide dispersion. The mass ratio of graphene oxide, deionized water, sodium hydroxide, and monochloroacetic acid was 0.1:120:6.5:5.5. Ultrasonic reaction was performed for 2.5 h at a frequency of 80 kHz. After the reaction was completed, filtration was performed, and washing was performed three times with deionized water. Drying was performed in a vacuum drying oven at 50°C for 24 h to obtain carboxylated graphene oxide. The carboxylated graphene oxide was added to ethanol and ultrasonically dispersed for 30 min at a frequency of 50 kHz. The pH value was adjusted to 6 using 1 mol / L hydrochloric acid. A γ-methacryloyloxypropyltrimethoxysilane-ethanol mixture was added dropwise. The mass ratio of carboxylated graphene oxide, ethanol, and the γ-methacryloyloxypropyltrimethoxysilane-ethanol mixture was 1:60:120. After dropwise addition was completed, reaction was performed at a temperature of 70°C for 20 h. After the reaction was completed, filtration was performed, and washing was performed three times with ethanol. Drying was performed in a vacuum drying oven at 50°C for 12 h to obtain alkenyl-modified graphene oxide. The γ-methacryloyloxypropyltrimethoxysilane-ethanol mixture was prepared by mixing γ-methacryloyloxypropyltrimethoxysilane with 95 wt% aqueous ethanol. The concentration of γ-methacryloyloxypropyltrimethoxysilane was 25 g / L. Preparation of the chloro-propenyl-modified hindered phenol includes: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine and 2-chloro-propenyl isothiocyanate were added to ethanol. The mass ratio of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine, 2-chloro-propenyl isothiocyanate, and ethanol was 29.2:16:600. Reflux reaction was performed at a temperature of 95°C for 4 h. After the reaction was completed, cooling was performed to room temperature. Filtration was performed, and recrystallization was performed using a mixed solvent of chloroform and petroleum ether to obtain a thiourea-modified hindered phenol. The thiourea-modified hindered phenol, mercury oxide, chloroform, and deionized water were mixed. The mass ratio of the thiourea-modified hindered phenol, mercury oxide, chloroform, and deionized water was 4.3:8.5:220:145. Stirring reaction was performed at room temperature for 50 h. After the reaction was completed, the chloroform layer became black. Filtration was performed until the filtrate became clear. Drying was performed using CaCl2 for 2 h. Filtration was performed. The solvent was removed under reduced pressure. Recrystallization was performed using ethyl acetate. Drying was performed in a vacuum drying oven at 50°C for 12 h to obtain a chloro-propenyl-modified hindered phenol. S2, 4-propenyl oxy-2-hydroxybenzophenone is added into toluene and stirred until dissolved to obtain a 4-propenyl oxy-2-hydroxybenzophenone solution; benzoyl peroxide, alkenyl-modified graphene oxide, chloro-propenyl-modified hindered phenol are added into the 4-propenyl oxy-2-hydroxybenzophenone solution, the mass ratio of 4-propenyl oxy-2-hydroxybenzophenone, toluene, benzoyl peroxide, alkenyl-modified graphene oxide, chloro-propenyl-modified hindered phenol is 55:1000:4.2:52:44, after stirring and dispersing, the temperature is raised to 100℃, and the reaction is carried out at 100℃ for 1h, after the reaction is completed, toluene is removed by rotary evaporation at 75℃, the product after rotary evaporation is washed with ethanol for 3 times, and is placed in a 50℃ vacuum drying oven for drying for 12h to obtain a composite modifier; The slurry is coated on the surface of the PET release film, and a polyurethane transfer layer is formed through solidification, water washing and drying; The coating amount of the slurry is 200g / m 2 The solidification condition is solidification in 18wt% N,N-dimethylformamide aqueous solution at room temperature for 20min, the water washing condition is water washing at a temperature of 70℃, the water washing process is extruded once every 5min, and the extrusion is performed 10 times, and the drying condition is drying at 110℃ for 15min.

[0023] Step (2), a hot melt adhesive film is attached to the surface of the polyurethane transfer layer, and a bonding layer is formed through pressing and cooling to obtain a far infrared thermal polyurethane transfer film containing graphene; The thickness of the hot melt adhesive film is 0.15mm, the softening point of the hot melt adhesive film is 126℃, and the pressing pressure is 5MPa. The far infrared thermal polyurethane transfer film containing graphene comprises a support layer, a polyurethane transfer layer and a bonding layer, the support layer is a PET release film layer, and the bonding layer is a hot melt adhesive film layer.

[0024] Example 3

[0025] The embodiment discloses a preparation method of a far infrared thermal polyurethane transfer film containing graphene, and comprises the following steps: Step (1), polyether polyurethane resin and polyester polyurethane resin are dissolved in N,N-dimethylformamide, organic pigment permanent yellow GG and a composite modifier are added, and stirring and mixing are performed to obtain a slurry; The mass ratio of the polyether polyurethane resin, the polyester polyurethane resin, the N,N-dimethylformamide, the organic pigment permanent yellow GG and the composite modifier is 50:50:40:2.5:6. The composite modifier is prepared by the following steps: S1, alkenyl-modified graphene oxide and chloro-propenyl-modified hindered phenol are prepared; wherein the preparation of the alkenyl-modified graphene oxide comprises: The graphene oxide was dispersed in deionized water and ultrasonically dispersed for 30 min at a frequency of 50 kHz to obtain a graphene oxide dispersion liquid. Sodium hydroxide and monochloroacetic acid were added to the graphene oxide dispersion liquid. The mass ratio of graphene oxide, deionized water, sodium hydroxide, and monochloroacetic acid was 0.1:100:6:5. Ultrasonic reaction was performed for 3 h at a frequency of 70 kHz. After the reaction was completed, filtration was performed, and washing was performed three times with deionized water. Drying was performed in a vacuum drying oven at 50°C for 24 h to obtain carboxylated graphene oxide. The carboxylated graphene oxide was added to ethanol and ultrasonically dispersed for 30 min at a frequency of 50 kHz. The pH value was adjusted to 5.5 using 1 mol / L hydrochloric acid. A γ-methacryloyloxypropyltrimethoxysilane-ethanol mixture was added dropwise. The mass ratio of carboxylated graphene oxide, ethanol, and the γ-methacryloyloxypropyltrimethoxysilane-ethanol mixture was 1:55:100. After dropwise addition was completed, reaction was performed at a temperature of 60°C for 24 h. After the reaction was completed, filtration was performed, and washing was performed three times with ethanol. Drying was performed in a vacuum drying oven at 50°C for 12 h to obtain alkenyl-modified graphene oxide. The γ-methacryloyloxypropyltrimethoxysilane-ethanol mixture was prepared by mixing γ-methacryloyloxypropyltrimethoxysilane with 95 wt% ethanol aqueous solution. The concentration of γ-methacryloyloxypropyltrimethoxysilane was 30 g / L. wherein the preparation of the chloro-propenyl-modified hindered phenol comprises: 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine and 2-chloro-propenyl isothiocyanate were added to ethanol. The mass ratio of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine, 2-chloro-propenyl isothiocyanate, and ethanol was 29.2:15:500. Reflux reaction was performed at a temperature of 90°C for 4.5 h. After the reaction was completed, cooling was performed to room temperature. Filtration was performed. Recrystallization was performed using a mixed solvent of chloroform and petroleum ether to obtain a thiourea-modified hindered phenol. The thiourea-modified hindered phenol, mercury oxide, chloroform, and deionized water were mixed. The mass ratio of the thiourea-modified hindered phenol, mercury oxide, chloroform, and deionized water was 4.3:8.4:215:140. Stirring reaction was performed at room temperature for 48 h. After the reaction was completed, the chloroform layer became black. Filtration was performed until the filtrate became clear. Drying was performed using CaCl2 for 2 h. Filtration was performed. The solvent was removed under reduced pressure. Recrystallization was performed using ethyl acetate. Drying was performed in a vacuum drying oven at 50°C for 12 h to obtain a chloro-propenyl-modified hindered phenol. S2, 4-propenyl-oxy-2-hydroxybenzophenone was added into toluene and stirred until dissolved to obtain a 4-propenyl-oxy-2-hydroxybenzophenone solution; benzoyl peroxide, alkenyl-modified graphene oxide, chloro-propenyl-modified hindered phenol were added into the 4-propenyl-oxy-2-hydroxybenzophenone solution, the mass ratio of 4-propenyl-oxy-2-hydroxybenzophenone, toluene, benzoyl peroxide, alkenyl-modified graphene oxide, chloro-propenyl-modified hindered phenol was 53:900:3.6:50:43.5, after stirring and dispersing, the temperature was raised to 95℃, and the reaction was carried out at 95℃ for 1.5h, after the reaction was completed, toluene was removed by rotary evaporation at 75℃, the product after rotary evaporation was washed with ethanol for 3 times, and was dried in a vacuum drying oven at 50℃ for 12h to obtain a composite modifier; The slurry was coated on the surface of the PET release film, and a polyurethane transfer layer was formed by solidification, water washing and drying; The coating amount of the slurry was 200g / m 2 The solidification condition was 20min at room temperature in 18wt% N,N-dimethylformamide aqueous solution, the water washing condition was water washing at 70℃, and the slurry was extruded once every 5min, 10 times in total, and the drying condition was drying at 110℃ for 15min.

[0026] Step (2), a hot melt adhesive film was attached to the surface of the polyurethane transfer layer, and a bonding layer was formed by pressing and cooling to obtain a far infrared thermal polyurethane transfer film containing graphene; The thickness of the hot melt adhesive film was 0.15mm, the softening point of the hot melt adhesive film was 126℃, and the pressure of the pressing was 5MPa. The far infrared thermal polyurethane transfer film containing graphene comprises a support layer, a polyurethane transfer layer and a bonding layer, the support layer is a PET release film layer, and the bonding layer is a hot melt adhesive film layer.

[0027] Comparative Example 1 The present comparative example discloses a preparation method of a far infrared thermal polyurethane transfer film containing graphene, comprising the following steps: Step (1), polyether polyurethane resin and polyester polyurethane resin were dissolved in N,N-dimethylformamide, organic pigment permanent yellow GG and composite modifier were added, and stirred and mixed to obtain a slurry; The mass ratio of the polyether polyurethane resin, the polyester polyurethane resin, N,N-dimethylformamide, the organic pigment permanent yellow GG and the composite modifier was 50:50:35:2:4; The composite modifier was prepared by the following steps: S1, alkenyl-modified graphene oxide was prepared: The graphene oxide is dispersed in deionized water, ultrasonic dispersion is carried out for 30 min at a frequency of 50 kHz to obtain a graphene oxide dispersion liquid, sodium hydroxide and monochloroacetic acid are added to the graphene oxide dispersion liquid, the mass ratio of graphene oxide, deionized water, sodium hydroxide and monochloroacetic acid is 0.1:80:5.5:4.5, ultrasonic reaction is carried out for 3.5 h at a frequency of 60 kHz, after the reaction is completed, filtration is carried out, washing with deionized water is carried out for 3 times, and drying is carried out in a vacuum drying box at 50℃ for 24 h to obtain carboxylated graphene oxide; The carboxylated graphene oxide is added into ethanol, ultrasonic dispersion is carried out for 30 min at a frequency of 50 kHz, 1 mol / L hydrochloric acid is used to adjust the pH value to 5, and the γ-methacryloyloxypropyl trimethoxysilane-ethanol mixed solution is added dropwise, the mass ratio of carboxylated graphene oxide, ethanol and the γ-methacryloyloxypropyl trimethoxysilane-ethanol mixed solution is 1:50:80, after dropwise addition is completed, reaction is carried out at a temperature of 50℃ for 30 h, after the reaction is completed, filtration is carried out, washing with ethanol is carried out for 3 times, and drying is carried out in a vacuum drying box at 50℃ for 12 h to obtain alkenyl-modified graphene oxide; The γ-methacryloyloxypropyl trimethoxysilane-ethanol mixed solution is prepared by mixing γ-methacryloyloxypropyl trimethoxysilane with 95wt% ethanol aqueous solution, and the concentration of γ-methacryloyloxypropyl trimethoxysilane is 35g / L; S2, 4-propenyloxy-2-hydroxybenzophenone is added into toluene and stirred until dissolved to obtain a 4-propenyloxy-2-hydroxybenzophenone solution; benzoyl peroxide and alkenyl-modified graphene oxide are added into the 4-propenyloxy-2-hydroxybenzophenone solution, the mass ratio of 4-propenyloxy-2-hydroxybenzophenone, toluene, benzoyl peroxide and alkenyl-modified graphene oxide is 50.8:800:1.8:48, after stirring and dispersing, the temperature is raised to 90℃, reaction is carried out at 90℃ for 2 h, after the reaction is completed, toluene is removed by rotary evaporation at a temperature of 75℃, the product after rotary evaporation is washed with ethanol for 3 times, and drying is carried out in a vacuum drying box at 50℃ for 12 h to obtain a composite modifier; The slurry is coated on the surface of a PET release film, and a polyurethane transfer layer is formed through solidification, water washing and drying; The coating amount of the slurry is 200g / m 2 The solidification condition is solidification in 18wt% N,N-dimethylformamide aqueous solution at room temperature for 20 min, the water washing condition is water washing at a temperature of 70℃, the water washing process is extruded once every 5 min, and the extrusion is carried out for 10 times, and the drying condition is drying at 110℃ for 15 min.

[0028] Step (2), a hot melt adhesive film is attached to the surface of the polyurethane transfer layer, a bonding layer is formed through pressing and cooling, and a far infrared thermal polyurethane transfer film containing graphene is obtained. The thickness of the hot melt adhesive film is 0.15mm, the softening point of the hot melt adhesive film is 126℃, and the pressure of the pressing is 5MPa. The graphene-containing far-infrared thermal polyurethane transfer film comprises a support layer, a polyurethane transfer layer and a bonding layer, the support layer is a PET release film layer, and the bonding layer is a hot melt adhesive film layer.

[0029] Comparative Example 2 The present comparative example discloses a preparation method of a graphene-containing far-infrared thermal polyurethane transfer film, comprising the following steps: Step (1), dissolving polyether polyurethane resin and polyester polyurethane resin in N,N-dimethylformamide, adding organic pigment permanent yellow GG and composite modifier, stirring and mixing to obtain slurry; The mass ratio of the polyether polyurethane resin, the polyester polyurethane resin, the N,N-dimethylformamide, the organic pigment permanent yellow GG and the composite modifier is 50:50:35:2:4; The composite modifier is prepared by the following steps: S1, preparing alkenyl-modified graphene oxide and alkenyl-modified hindered phenol; The preparation of the alkenyl-modified graphene oxide comprises: The graphene oxide is dispersed in deionized water and ultrasonically dispersed at a frequency of 50 kHz for 30 min to obtain a graphene oxide dispersion liquid. Sodium hydroxide and monochloroacetic acid are added to the graphene oxide dispersion liquid. The mass ratio of the graphene oxide, the deionized water, the sodium hydroxide and the monochloroacetic acid is 0.1:80:5.5:4.5. Ultrasonic reaction is carried out at a frequency of 60 kHz for 3.5 h. After the reaction is completed, filtration is carried out, washing with deionized water is carried out for 3 times, and drying is carried out in a vacuum drying oven at 50℃ for 24 h to obtain carboxylated graphene oxide. The carboxylated graphene oxide is added to ethanol and ultrasonically dispersed at a frequency of 50 kHz for 30 min. The pH value is adjusted to 5 by using 1 mol / L hydrochloric acid. A γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is added dropwise. The mass ratio of the carboxylated graphene oxide, the ethanol and the γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is 1:50:80. After the dropwise addition is completed, reaction is carried out at a temperature of 50℃ for 30 h. After the reaction is completed, filtration is carried out, washing with ethanol is carried out for 3 times, and drying is carried out in a vacuum drying oven at 50℃ for 12 h to obtain alkenyl-modified graphene oxide. The γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is prepared by using γ-methacryloxypropyltrimethoxysilane and 95wt% ethanol aqueous solution. The concentration of the γ-methacryloxypropyltrimethoxysilane is 35g / L. The preparation of the alkenyl-modified hindered phenol comprises: The 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine is added into toluene, and 3-isocyanate propylene is added dropwise under ice bath stirring, the mass ratio of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl hydrazine, toluene, 3-isocyanate propylene is 29.2:500:9, the dropwise adding time of 3-isocyanate propylene is 30 min, after the dropwise adding is completed, the reaction is carried out at 5℃ for 5h, after the reaction is completed, filtration is carried out, the filter cake is recrystallized with chloroform, and the recrystallization is dried in a vacuum drying box at 50℃ for 12h to obtain the alkenyl-modified hindered phenol; S2, 4-propenyloxy-2-hydroxybenzophenone is added into toluene and stirred until dissolved to obtain a 4-propenyloxy-2-hydroxybenzophenone solution; benzoyl peroxide, alkenyl-modified graphene oxide, alkenyl-modified hindered phenol are added into the 4-propenyloxy-2-hydroxybenzophenone solution, the mass ratio of 4-propenyloxy-2-hydroxybenzophenone, toluene, benzoyl peroxide, alkenyl-modified graphene oxide, alkenyl-modified hindered phenol is 50.8:800:1.8:48:42.6, after stirring and dispersing, the temperature is raised to 90℃, the reaction is carried out at 90℃ for 2h, after the reaction is completed, toluene is removed by rotary evaporation at 75℃, the product after rotary evaporation is washed with ethanol for 3 times, and is dried in a vacuum drying box at 50℃ for 12h to obtain a composite modifier; The slurry is coated on the surface of the PET release film, and a polyurethane transfer layer is formed through solidification, water washing and drying; The coating amount of the slurry is 200g / m 2 The solidification condition is solidification in 18wt% N,N-dimethylformamide aqueous solution at room temperature for 20min, the water washing condition is water washing at a temperature of 70℃, the water washing process is extruded once every 5min, and the extrusion is performed 10 times, and the drying condition is drying at 110℃ for 15min.

[0030] Step (2), a hot melt adhesive film is attached to the surface of the polyurethane transfer layer, a bonding layer is formed through pressing and cooling, and a far infrared thermal polyurethane transfer film containing graphene is obtained; The thickness of the hot melt adhesive film is 0.15mm, the softening point of the hot melt adhesive film is 126℃, and the pressing pressure is 5MPa. The far infrared thermal polyurethane transfer film containing graphene comprises a support layer, a polyurethane transfer layer and a bonding layer, the support layer is a PET release film layer, and the bonding layer is a hot melt adhesive film layer.

[0031] In the above examples and comparative examples, the polyester type polyurethane is polycarbonate polyurethane, the processing temperature is 160-180℃, and the polyether type polyurethane is polytetrahydrofuran ether glycol type polyurethane, and the temperature resistance is 120-130℃.

[0032] Test Example (1) Warm-keeping performance and far infrared heating performance: the polyurethane transfer film is attached to the surface of the leather base cloth, the bonding layer of the polyurethane transfer film is in contact with the leather base cloth, and then compression and cooling are performed to obtain a polyurethane synthetic leather sample; the warm-keeping performance of the synthetic leather sample is determined according to the standard GB / T35762-2017 “Textiles - Determination of thermal transmission property - Flat-plate method”; the far infrared heating performance of the synthetic leather sample is determined according to the standard GB / T30127-2013 “Textiles - Determination and evaluation of far infrared property”; and the determination results of the warm-keeping performance and the far infrared heating performance are shown in Table 1 and Table 2, respectively: Table 1

[0033] As shown in Table 1, the polyurethane transfer film prepared in the application has good warm-keeping performance. The introduction of graphene can effectively improve the warm-keeping performance of the polyurethane transfer film; the higher the CLO value, the better the warm-keeping performance of the polyurethane synthetic leather sample. Compared with Example 1, in Comparative Example 1, the amount of the modifier graphene is increased without changing the amount of the composite modifier and without containing the hindered phenol in the composite modifier, and the warm-keeping performance is actually enhanced.

[0034] Table 2

[0035] As shown in Table 2, the polyurethane transfer film prepared in the application has good far infrared heating performance. The introduction of graphene can effectively improve the far infrared heating performance of the polyurethane transfer film. Compared with Example 1, in Comparative Example 1, the amount of the modifier graphene is increased without changing the amount of the composite modifier and without containing the hindered phenol in the composite modifier, and the far infrared heating performance is actually enhanced.

[0036] (2) Anti-ultraviolet performance: the polyurethane synthetic leather sample obtained by the method in Test Example (1) is irradiated under ultraviolet light of 380 nm for 4000 h, and the color change value, i.e. the color difference (ΔE), before and after irradiation is determined, and the determination results are shown in Table 3, respectively: Table 3

[0037] As shown in Table 3, the polyurethane transfer film prepared in the application has good anti-ultraviolet performance. The addition of the ultraviolet absorber 4-propyleneoxy-2-hydroxybenzophenone can effectively improve the anti-ultraviolet performance of the polyurethane transfer film. Compared with Example 1, in Comparative Example 1, the amount of the ultraviolet absorber is increased without changing the amount of the composite modifier and without containing the hindered phenol in the composite modifier, and the anti-ultraviolet performance is actually enhanced.

[0038] (3) Oxidation resistance: the slurry prepared in step (1) of Example-3 and Comparative Examples 1-2 was cast, then solidified, washed, extruded, dried, and cut into dumbbell-shaped test samples according to the methods of Example 1-3 and Comparative Examples 1-2, respectively. The tensile strength retention rate of the test samples after thermal oxidation aging at 140°C for 1000h was determined according to ISO527-2012 at a tensile rate of 5mm / min. The test results are shown in Table 4: Table 4

[0039] As shown in Table 4, the polyurethane transfer film prepared in the present application has good oxidation resistance. The introduction of hindered phenolic antioxidant can effectively improve the oxidation resistance of the polyurethane transfer film. Compared with Example 1, in Comparative Example 1, the composite modifier does not contain a chloro-propenyl-modified hindered phenol, and no hindered phenolic antioxidant is introduced, and the oxidation resistance is greatly reduced.

[0040] (4) Hydrolysis resistance: the test samples obtained by the method of Test Example (3) were boiled in water at 120°C for 200h, and then the tensile strength retention rate of the test samples was determined according to ISO527-2012 at a tensile rate of 5mm / min. The test results are shown in Table 5: Table 5

[0041] As shown in Table 5, the polyurethane transfer film prepared in the present application has good hydrolysis resistance. In the preparation of the composite modifier, the reaction of 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl hydrazine and 2-chloro-propenyl isothiocyanate introduces an alkenyl group into the molecular structure of the hindered phenolic antioxidant, and the carbodiimide group generated by the reaction of the hydrazide group and the isothiocyanate group has excellent hydrolysis resistance, which can effectively improve the hydrolysis resistance of the polyester polyurethane, and further improve the hydrolysis resistance of the polyurethane transfer film. Compared with Example 1, in Comparative Example 1, the composite modifier does not contain a chloro-propenyl-modified hindered phenol, i.e., no carbodiimide is introduced, and the hydrolysis resistance is greatly reduced; in Comparative Example 2, the alkenyl-modified hindered phenol is prepared by the reaction of 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl hydrazine and 3-isocyanate propylene, and no carbodiimide is introduced, and the hydrolysis resistance of the polyurethane transfer film is greatly reduced.

[0042] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A far infrared warming polyurethane transfer film containing graphene, characterized by, It comprises a support layer, a polyurethane transfer layer on one side of the support layer, and a bonding layer on the other side of the polyurethane transfer layer; The support layer comprises a PET release film layer; The bonding layer comprises a hot melt adhesive film layer; The raw materials for preparing the polyurethane transfer layer comprise polyurethane resin, organic solvent, organic pigment, and composite modifier; The composite modifier is prepared by the following steps: S1, preparing alkenyl-modified graphene oxide and chloro-propenyl-modified hindered phenol; Preparation of alkenyl-modified graphene oxide comprises: Carboxylated graphene oxide is reacted with γ-methacryloxypropyltrimethoxysilane to obtain alkenyl-modified graphene oxide; Preparation of chloro-propenyl-modified hindered phenol comprises: 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl hydrazine is reacted with 2-chloro-propenyl isothiocyanate to obtain chloro-propenyl-modified hindered phenol; S2, alkenyl-modified graphene oxide, chloro-propenyl-modified hindered phenol, and 4-propenyloxy-2-hydroxybenzophenone are reacted to prepare a composite modifier.

2. The graphene-containing far infrared warming polyurethane transfer film according to claim 1, characterized in that, The mass ratio of the polyurethane resin, the organic solvent, the organic pigment, and the composite modifier is 100:(35-45):(2-3):(4-8).

3. The graphene-containing far infrared warming polyurethane transfer film according to claim 2, characterized in that, The polyurethane resin comprises polyether type polyurethane resin and polyester type polyurethane resin; The mass ratio of the polyether type polyurethane resin and the polyester type polyurethane resin is (0.5-2):1; The organic solvent comprises N,N-dimethylformamide.

4. The graphene-containing far infrared warming polyurethane transfer film according to claim 1, characterized in that, In S1, the preparation of alkenyl-modified graphene oxide specifically comprises: Carboxylated graphene oxide is added to ethanol, ultrasonic dispersion is performed, the pH value is adjusted to 5-6, γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is added dropwise, after the dropwise addition is completed, reaction is performed, after the reaction is completed, filtration, washing, and drying are performed to obtain alkenyl-modified graphene oxide; The mass ratio of carboxylated graphene oxide, ethanol, and γ-methacryloxypropyltrimethoxysilane-ethanol mixed solution is 1:(50-60):(80-120), and the reaction condition is 50-70℃ for 20-30h.

5. The graphene-containing far infrared warming polyurethane transfer film according to claim 4, characterized in that, The carboxylated graphene oxide is prepared by the following steps: Graphene oxide is dispersed in deionized water to obtain a graphene oxide dispersion liquid, sodium hydroxide and monochloroacetic acid are added to the graphene oxide dispersion liquid, reaction is performed, after the reaction is completed, filtration, washing, and drying are performed to obtain carboxylated graphene oxide; The mass ratio of graphene oxide, deionized water, sodium hydroxide, and monochloroacetic acid is 0.1:(80-120):(5.5-6.5):(4.5-5.5), and the reaction condition is ultrasonic reaction at a frequency of 60-80kHz for 2.5-3.5h.

6. The graphene-containing far infrared warming polyurethane transfer film according to claim 1, characterized in that, In S1, the preparation of chloro-propenyl-modified hindered phenol specifically comprises: 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl hydrazine and 2-chloro-propenyl isothiocyanate are added to ethanol, reaction is performed, after the reaction is completed, cooling, filtration, and recrystallization are performed to obtain a thiourea-modified hindered phenol; The mass ratio of 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl hydrazine, 2-chloropropenyl isothiocyanate and ethanol is 29.2:(14-16):(400-600), and the reaction condition is refluxing at 85-95 DEG C for 4-5h; The thiourea modified hindered phenol, mercury oxide, chloroform and deionized water are mixed, reacted, separated and purified, and dried to obtain the chloropropenyl modified hindered phenol. The mass ratio of the thiourea modified hindered phenol, mercury oxide, chloroform and deionized water is 4.3:(8.2-8.5):(205-220):(135-145), and the reaction condition is stirring at room temperature for 45-50h.

7. The graphene-containing far infrared warming polyurethane transfer film according to claim 1, characterized in that, In S2, the composite modifier is prepared, specifically including: The 4-propenyl-2-hydroxybenzophenone is added into toluene and stirred until dissolved to obtain a 4-propenyl-2-hydroxybenzophenone solution; the benzoyl peroxide, the alkenyl modified graphene oxide, and the chloropropenyl modified hindered phenol are added into the 4-propenyl-2-hydroxybenzophenone solution, stirred and dispersed, then heated to a set temperature, reacted, and after the reaction, rotary evaporated, purified and dried to obtain the composite modifier. The mass ratio of the 4-propenyl-2-hydroxybenzophenone, toluene, benzoyl peroxide, alkenyl modified graphene oxide and chloropropenyl modified hindered phenol is (50.8-55):(800-1000):(1.8-4.2):(48-52):(42.6-44), and the reaction condition is reacting at the set temperature for 1-2h. The set temperature is 90-100 DEG C.

8. A method of producing a far infrared warming polyurethane transfer film containing graphene according to any one of claims 1 to 7, characterized by, The steps include: Step (1), the polyurethane resin is dissolved in an organic solvent, the organic pigment and the composite modifier are added and stirred to obtain a slurry; the slurry is coated on the surface of a PET release film, and after solidification, water washing and drying, a polyurethane transfer layer is formed; Step (2), a hot melt adhesive film is attached to the surface of the polyurethane transfer layer, and after pressing and cooling, a bonding layer is formed to obtain a graphene-containing far infrared thermal polyurethane transfer film; The graphene-containing far infrared thermal polyurethane transfer film includes a support layer, a polyurethane transfer layer and a bonding layer, the support layer is a PET release film layer, and the bonding layer is a hot melt adhesive film layer.

9. The method for preparing a far-infrared heat-insulating polyurethane transfer film containing graphene according to claim 8, characterized in that, The coating amount of the slurry in step (1) is 180-240 g / m 2 The coagulation conditions are coagulation in 16 wt% to 20 wt% aqueous N,N-dimethylformamide at room temperature for 15-20 min, the water washing conditions are water washing at a temperature of 60-80 °C, the water washing is performed by extrusion every 5 min, 5-10 times of extrusion, and the drying conditions are drying at 100-120 °C for 10-20 min.

10. The method for preparing a graphene-containing far-infrared heat-insulating polyurethane transfer film according to claim 8, characterized in that, In step (2), the thickness of the hot melt adhesive film is 0.1-0.2mm, the softening point of the hot melt adhesive film is 120-130 DEG C, and the pressure of the pressing is 4-6MPa.

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