An electrothermal film surface modification treatment method and an environment-friendly electrothermal film

Abstract

The application discloses a kind of electric heating film surface modification treatment method and environment-friendly electric heating film, belong to heating field.It is by solventless green environmental protection UV photocuring surface treatment to carbon fiber and PET film, obtain the carbon fiber prepreg and PET functional film that can be stored for a long time, when needing to carry out multilayer composite process, the two are compounded, short-time heating crosslinking is carried out, through the crosslinking reaction of carboxyl and epoxy group, just can obtain the composite layer with high interlayer composite force, structure is compact, so that electric heating film can be attached on wall body on a large scale conveniently, can generate far infrared radiation after electrification to realize heating, construction is convenient, low carbon environmental protection, the obtained electric heating film also has high stability, adhesion, flexibility and good weather resistance, can solve electric heating film easily deforms, service life is shorter, there are problems such as safety hidden trouble due to static electricity.

Description

Technical Field

[0001] This invention relates to the field of heating, and more particularly to a method for surface modification of an electric heating film and an environmentally friendly electric heating film. Background Technology

[0002] As people's living standards improve, various underfloor heating and wall heating products are gaining an increasingly larger share of the home heating market. Wall heating, as opposed to underfloor heating, involves installing the heating equipment on the wall. Currently, wall heating systems generally adopt a modular design, with the heating equipment designed as thin, panel-like modules that are hung on the wall. However, existing wall heating products still suffer from problems such as short lifespan, susceptibility to deformation, poor radiation performance, and unsightly appearance.

[0003] Given the aforementioned technical problems with existing wall heating devices, it is necessary to propose a new wall heating solution. This solution involves many aspects, including the preparation of heating materials, the molding of the heating wall (how the heating material integrates with the wall), and the construction of the heating system. In the preparation of the electric heating film, its core components are multi-layered carbon fiber and PET film, which are composited in multiple layers to create the electric heating film. For ease of construction, the carbon fiber layers and PET film layers need to undergo surface modification treatment beforehand.

[0004] In the preparation of electrothermal films, the core components are multilayered carbon fibers and PET films, which are then composited to form the electrothermal film. The carbon fiber layers and PET film layers require pre-treatment for surface modification. For ease of application, the pre-modified carbon fiber prepreg and PET functional film need to be able to be stored stably for a long period before being processed and used in the preparation of the thermoelectric film. If the modified carbon fiber prepreg and PET functional film cannot be stored stably for a long period, then the thermoelectric film preparation process must be carried out immediately after the surface modification treatment of the carbon fiber and PET film, which is inconvenient in terms of process convenience. Summary of the Invention

[0005] The main objective of this invention is to provide a method for surface modification of electrothermal film and an environmentally friendly electrothermal film, aiming to solve the technical problem that the modified carbon fiber prepreg and PET functional film cannot be stored stably for a long time during the preparation of electrothermal film, which limits the convenience of the preparation process.

[0006] To achieve the above objectives, the present invention provides a method for surface modification of an electrothermal film, wherein the electrothermal film comprises a PET film layer and a carbon fiber layer, and includes the following steps:

[0007] S10, surface modification of carbon fiber:

[0008] All raw materials constituting the epoxy-containing UV curable adhesive are mixed evenly to obtain the epoxy-containing UV curable adhesive; then the epoxy-containing UV curable adhesive is impregnated with carbon fiber and cured by ultraviolet light to prepare a UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg.

[0009] The epoxy-containing UV curable adhesive comprises the following raw materials by weight: 3-5 parts photoinitiator, 30-40 parts epoxy acrylate UV resin, 20-30 parts epoxy acrylate diluent, and 20-40 parts polyurethane acrylate UV resin.

[0010] S20, surface modification of PET film:

[0011] All raw materials constituting the UV-curable carboxyl-containing coating are mixed evenly to obtain the UV-curable carboxyl-containing coating; then the UV-curable carboxyl-containing coating is coated onto a PET film and cured by ultraviolet light to prepare a UV-curable carboxyl-containing coating surface-treated PET functional film.

[0012] The UV-curable carboxyl-containing coating, calculated by weight, comprises the following raw materials: 3-5 parts photoinitiator, 5-15 parts carboxyl acrylate monomer, 30-40 parts polyurethane acrylate, and 40-50 parts high acid value polyester acrylate UV resin.

[0013] Optionally, at least one layer of the UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg is bonded together with at least one layer of the UV-cured carboxyl-containing coating surface-treated PET functional film, and then heated for cross-linking to complete the preparation of the electrothermal film with respect to the PET film layer and the carbon fiber layer.

[0014] Optionally, the curing energy density is 1000-2000 mJ / cm³. 2 .

[0015] Optionally, the photoinitiator comprises at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0016] Optionally, the epoxy acrylate diluent comprises at least one of glycidyl acrylate and glycidyl methacrylate.

[0017] Optionally, in the step of surface modification of carbon fibers, the epoxy acrylate UV resin has a vinyl functionality ≥2, a viscosity of 10000-20000 mpa.s at 60°C, a softening point ≥100°C, and an epoxy equivalent of 1000-2000 g / Eq.

[0018] Optionally, in the step of surface modification of carbon fibers, the polyurethane acrylate UV resin has a vinyl functionality ≥2, a viscosity of 5000-30000 mpa.s at 60°C, and a glass transition temperature (Tg) ≤50°C.

[0019] Optionally, the carboxyacrylate monomer comprises at least one of acrylic acid and methacrylic acid.

[0020] Optionally, in the step of surface modification of the PET film, the polyurethane acrylate has a vinyl functionality ≥2 and a viscosity of 15000-25000 mPa·s at 60°C.

[0021] Optionally, in the step of surface modification of the PET film, the high acid value polyester acrylate UV resin has a viscosity of 200-5000 mpa.s at 25°C, an acid value of 100-300 mg KOH / g, and a vinyl functionality ≥1.

[0022] Optionally, in the step of surface modification of the PET film, the thickness of the UV-cured carboxyl-containing coating applied to the PET film is 10-20 μm.

[0023] In addition, to achieve the above objectives, the present invention also provides an environmentally friendly electrothermal film prepared by the surface modification treatment method described above.

[0024] The beneficial effects that this invention can achieve are:

[0025] Both carbon fiber and PET film undergo solvent-free, environmentally friendly UV curing processes. The UV-cured epoxy-based composite carbon fiber prepreg and the UV-cured carboxyl-based coated PET functional film obtained through the above surface modification treatment can be rolled up and stored for a long time. When an electric heating film is needed, the two are multi-layered composites. Under heating conditions, the core components of the electric heating film can be obtained in a short time through cross-linking of epoxy groups and carboxyl groups. This allows the electric heating film to be conveniently and extensively attached to walls, overcoming the limitations of existing wall heating products that can only be hung or attached to walls through complex construction methods. The construction is convenient, low-carbon, and environmentally friendly. After being powered on, it can generate far-infrared radiation to achieve heating.

[0026] The UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg and the UV-cured carboxyl-containing coating surface-treated PET functional film also play a protective, heat-conducting and heat-dissipating role, giving the electrothermal film high stability, adhesion, flexibility and good weather resistance, which can solve problems such as easy deformation, short service life and safety hazards caused by static electricity in electrothermal films. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 This is a schematic flowchart of the electrothermal film surface modification treatment method of the present invention.

[0029] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0033] Most wall heating systems currently use a modular design, where the heating equipment is designed as thin, plate-like modules that are hung on the wall. These wall heating products typically have problems such as short lifespan, easy deformation, difficult installation, and unsightly appearance.

[0034] Furthermore, in the preparation of the electrothermal film, its core components are multilayered carbon fiber and PET film. The carbon fiber layers and PET film layers need to undergo surface modification treatments beforehand, and then the two are composited in multiple layers to prepare the electrothermal film. For ease of construction, the pre-modified carbon fiber prepreg and PET functional film need to be able to be stored stably for a long period before being processed and used in the preparation of the thermoelectric film. If the modified carbon fiber prepreg and PET functional film cannot be stored stably for a long period, then the thermoelectric film preparation process must be carried out immediately after the surface modification treatment of the carbon fiber and PET film, which is insufficient in terms of process convenience.

[0035] In view of this, the present invention provides a method for surface modification of electrothermal films, mainly concerning the surface modification of PET films and carbon fibers, as described above. Figure 1 This includes the following steps:

[0036] S10, surface modification of carbon fiber:

[0037] All raw materials constituting the epoxy-containing UV curable adhesive are mixed evenly to obtain the epoxy-containing UV curable adhesive; then the epoxy-containing UV curable adhesive is impregnated with carbon fiber and cured by ultraviolet light to prepare a UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg.

[0038] The epoxy-containing UV curing adhesive, by weight, comprises the following raw materials: 3-5 parts photoinitiator, 30-40 parts epoxy acrylate UV resin, 20-30 parts epoxy acrylate diluent, and 20-40 parts polyurethane acrylate UV resin.

[0039] The above raw materials can be mixed at 25-35℃ and stirred at 1000-1500 rpm to quickly obtain a more uniform epoxy-containing UV-curable adhesive.

[0040] This invention does not limit the type of photoinitiator. Preferably, the photoinitiator comprises at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide. By adding the above photoinitiator, it can be cured with ultraviolet light at room temperature, promoting the polymerization between components and obtaining a structurally stable UV-cured epoxy-based composite carbon fiber prepreg. This prepreg can be stored stably for a long time, overcoming the limitations of the prior art where the carbon fiber must be immediately processed into a thermoelectric film after surface modification, greatly improving the processing convenience of the electrothermal film.

[0041] This invention does not limit the type of epoxy acrylate diluent. Preferably, the epoxy acrylate diluent includes at least one of glycidyl acrylate and glycidyl methacrylate. The viscosity of the system can be adjusted by using the diluent described above.

[0042] Preferably, the epoxy acrylate UV resin selected in this invention has a vinyl functionality ≥2, a viscosity of 10000-20000 mpa.s at 60°C, a softening point ≥100°C, and an epoxy equivalent of 1000-2000 g / Eq; the polyurethane acrylate UV resin has a vinyl functionality ≥2, a viscosity of 5000-30000 mpa.s at 60°C, and a glass transition temperature (Tg) ≤50°C.

[0043] Under the aforementioned preferred conditions, an epoxy-containing UV-curable adhesive with good flowability, wettability, and non-sagging properties at room temperature can be obtained. Furthermore, the epoxy acrylate UV resin contains abundant epoxy groups, which is one of the key conditions guiding the modified carbon fiber and modified PET film through heat crosslinking and lamination.

[0044] After the preparation of the epoxy-containing UV-curable adhesive is completed, carbon fibers are impregnated in the epoxy-containing UV-curable adhesive and subjected to UV curing treatment by irradiation. The photoinitiator can promote the polymerization between the components to form a UV-curable epoxy-containing adhesive layer composite carbon fiber prepreg with stable structure and uniform and smooth appearance.

[0045] Preferably, the curing energy density is 1000-2000 mJ / cm³. 2 The above-mentioned photocuring process can be carried out normally at a room temperature of 25-35℃.

[0046] After undergoing the modification treatment described above, carbon fiber is modified carbon fiber prepreg, which has good flexibility and weather resistance and can be stored for a long time.

[0047] S20, surface modification of PET film:

[0048] All raw materials constituting the UV-curable carboxyl-containing coating are mixed evenly to obtain the UV-curable carboxyl-containing coating; then the UV-curable carboxyl-containing coating is coated onto a PET film and cured by ultraviolet light to prepare a UV-curable carboxyl-containing coating surface-treated PET functional film.

[0049] The UV-curable carboxyl-containing coating comprises, by weight, the following raw materials: 3-5 parts photoinitiator, 5-15 parts carboxyl acrylate monomer, 30-40 parts polyurethane acrylate, and 40-50 parts high acid value polyester acrylate UV resin.

[0050] The above raw materials can be mixed at 25-35℃ and stirred at 1000-1500 rpm to quickly obtain a more uniform UV-curable carboxyl-containing coating.

[0051] This invention does not limit the type of photoinitiator. Preferably, the photoinitiator includes at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide. By adding the above photoinitiator, it can be cured with ultraviolet light at room temperature to promote the polymerization between components and obtain a UV-cured carboxyl-containing coating surface-treated PET functional film with uniform and stable coating. It can be stored stably for a long time, breaking the limitation of the prior art that the PET film must be prepared into a thermoelectric film immediately after the surface modification treatment, and greatly improving the processing convenience of the thermoelectric film.

[0052] This invention does not limit the type of carboxyacrylate monomer, but it needs to have abundant carboxyl groups so that the PET film can acquire carboxyl groups, and then undergo a composite reaction with the aforementioned UV-curable epoxy-containing adhesive layer composite carbon fiber prepreg. Preferably, the carboxyacrylate monomer contains at least one of acrylic acid and methacrylic acid.

[0053] The present invention preferably uses a high acid value polyester acrylate UV resin with the following physicochemical properties: viscosity at 25°C of 200-5000 mpa.s, acid value of 100-300 mg KOH / g, and vinyl functionality ≥1.

[0054] UV-curable carboxyl-containing coatings made from high-acid-value polyester acrylate UV resins can improve the adhesion of coatings on PET films. Furthermore, when UV-curable carboxyl-containing coatings of PET functional films containing high-acid-value polyester acrylate UV resins are laminated with UV-curable epoxy-containing carbon fiber prepregs, they facilitate full chemical cross-linking between the two, improve interlayer bonding strength, and shorten the lamination time.

[0055] The present invention does not limit the method of coating the UV-curable carboxyl-containing coating onto the PET film. Preferably, a roller coating process is used to obtain a more smooth and uniform UV-curable carboxyl-containing coating surface-treated PET functional film.

[0056] After completing the above modification of PET film and carbon fiber, they can be wound up and stored separately. When preparing the electrothermal film, at least one layer of UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg is bonded together with at least one layer of UV-cured carboxyl-containing coating surface-treated PET functional film, and then heated for cross-linking to complete the preparation of the electrothermal film with respect to the PET film layer and carbon fiber layer.

[0057] The present invention does not limit the temperature and time of crosslinking. Preferably, a composite layer of PET film layer and carbon fiber layer with high interlayer bonding force can be obtained by heating and crosslinking at 120-150℃ for 1-2 hours.

[0058] The UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg is rich in epoxy groups, and the UV-cured carboxyl-containing coating surface-treated PET functional film is rich in carboxyl groups. When the two are bonded together, under heating conditions, chemical cross-linking occurs between the carboxyl groups and epoxy groups, resulting in a tightly structured composite layer in a short time. This composite layer forms the core component of the electric heating film, making construction convenient, low-carbon, and environmentally friendly. It allows the electric heating film to be easily and conveniently attached to walls on a large scale. When powered on, it generates far-infrared radiation to achieve heating, overcoming the technical problem that existing wall heating products can only be hung or attached to walls through complex construction methods.

[0059] The UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg and the UV-cured carboxyl-containing coating surface-treated PET functional film also play a protective, heat-conducting and heat-dissipating role, giving the electrothermal film high stability, adhesion, flexibility and good weather resistance. It can solve problems such as the electrothermal film being easy to deform, having a short service life, and safety hazards caused by the PET film easily carrying static electricity.

[0060] The above-mentioned surface modification treatment methods are all solvent-free, green and environmentally friendly UV curing processes. The UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg and the UV-cured carboxyl-containing coating surface-treated PET functional film obtained constitute the core components of the electrothermal film. They are used to prepare electrothermal films, which are convenient to construct, low-carbon and environmentally friendly, and can produce environmentally friendly electrothermal films.

[0061] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0062] In the following examples, the epoxy acrylate UV resin has a vinyl functionality ≥2, a viscosity of 10000-20000 mpa.s at 60°C, a softening point ≥100°C, and an epoxy equivalent of 1000-2000 g / Eq; the polyurethane acrylate UV resin has a vinyl functionality ≥2, a viscosity of 5000-30000 mpa.s at 60°C, and a glass transition temperature (Tg) ≤50°C; and the high acid value polyester acrylate UV resin has a viscosity of 200-5000 mpa.s at 25°C, an acid value of 100-300 mg KOH / g, and a vinyl functionality ≥1.

[0063] Example 1

[0064] Reference Figure 1 , Figure 1This is a schematic diagram of a method for modifying the surface of an electrothermal film, including the following steps:

[0065] S10, surface modification of carbon fiber:

[0066] Weigh 3g of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone, 30g of epoxy acrylate UV resin, 30g of glycidyl methacrylate, and 37g of polyurethane acrylate UV resin. Stir at 1000rpm at 25℃ until homogeneous to obtain an epoxy-containing UV-curable adhesive. Impregnate carbon fibers with the epoxy-containing UV adhesive for dip coating, then apply a 1000mJ / cm² coating solution. 2 UV curing was performed using ultraviolet light to prepare UV-cured epoxy-based composite carbon fiber prepreg, which was then stored for later use.

[0067] S20, surface modification of PET film:

[0068] Weigh 3g of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone, 40g of polyurethane acrylate, 15g of acrylic acid, and 42g of high-acid-value polyester acrylate UV resin. Mix thoroughly at 1000rpm under 25°C to obtain a UV-curable carboxyl-containing coating. Apply the UV-curable carboxyl-containing coating to a PET film using a roller coating process, achieving a coating thickness of 20μm. Then, apply a 1000mJ / cm² spray. 2 UV curing was performed to prepare a UV-cured PET functional film with a carboxyl-containing coating, which was then stored for later use.

[0069] Example 2

[0070] Reference Figure 1 , Figure 1 This is a schematic diagram of a method for modifying the surface of an electrothermal film, including the following steps:

[0071] S10, surface modification of carbon fiber:

[0072] Weigh 5g of photoinitiator 1-hydroxycyclohexylphenyl ketone, 30g of epoxy acrylate UV resin, 30g of glycidyl acrylate, and 35g of polyurethane acrylate UV resin. Stir at 1000rpm at 25℃ until homogeneous to obtain an epoxy-containing UV-curable adhesive. Impregnate carbon fibers with the epoxy-containing UV adhesive for dip coating, then apply a 2000mJ / cm² coating solution. 2 UV curing was performed using ultraviolet light to prepare UV-cured epoxy-based composite carbon fiber prepreg, which was then stored for later use.

[0073] S20, surface modification of PET film:

[0074] Weigh 5g of photoinitiator 1-hydroxycyclohexylphenyl ketone, 40g of polyurethane acrylate, 5g of methacrylic acid, and 50g of high-acid-value polyester acrylate UV resin. Stir at 1500rpm at 25℃ until homogeneous to obtain a UV-curable carboxyl-containing coating. Apply the UV-curable carboxyl-containing coating to a PET film using a roller coating process, achieving a coating thickness of 15μm. Then, apply a solution of 1500mJ / cm². 2 UV curing was performed to prepare a UV-cured PET functional film with a carboxyl-containing coating, which was then stored for later use.

[0075] Example 3

[0076] Reference Figure 1 , Figure 1 This is a schematic diagram of a method for modifying the surface of an electrothermal film, including the following steps:

[0077] S10, surface modification of carbon fiber:

[0078] Weigh 4g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 40g of epoxy acrylate UV resin, 20g of glycidyl methacrylate, and 20g of polyurethane acrylate UV resin. Stir at 1500rpm at 30℃ until homogeneous to obtain an epoxy-containing UV-curable adhesive. Impregnate carbon fibers with the epoxy-containing UV adhesive for dip coating, then apply a coating solution of 1500mJ / cm². 2 UV curing was performed using ultraviolet light to prepare UV-cured epoxy-based composite carbon fiber prepreg, which was then stored for later use.

[0079] S20, surface modification of PET film:

[0080] Weigh 4g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 30g of polyurethane acrylate, 15g of methacrylic acid, and 50g of high-acid-value polyester acrylate UV resin. Mix thoroughly at 1500rpm under 30℃ to obtain a UV-curable carboxyl-containing coating. Apply the UV-curable carboxyl-containing coating to a PET film using a roller coating process, achieving a coating thickness of 10μm. Then, apply a 2000mJ / cm² spray. 2 UV curing was performed to prepare a UV-cured PET functional film with a carboxyl-containing coating, which was then stored for later use.

[0081] Example 4

[0082] Reference Figure 1 , Figure 1 This is a schematic diagram of a method for modifying the surface of an electrothermal film, including the following steps:

[0083] S10, surface modification of carbon fiber:

[0084] Weigh 3g of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone, 37g of epoxy acrylate UV resin, 20g of glycidyl acrylate, and 40g of polyurethane acrylate UV resin. Stir at 1000rpm at 25℃ until homogeneous to obtain an epoxy-containing UV-curable adhesive. Impregnate carbon fibers with the epoxy-containing UV adhesive for dip coating, then apply a 1500mJ / cm² coating solution. 2 UV curing was performed using ultraviolet light to prepare UV-cured epoxy-based composite carbon fiber prepreg, which was then stored for later use.

[0085] S20, surface modification of PET film:

[0086] Weigh 4g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 35g of polyurethane acrylate, 15g of acrylic acid, and 40g of high-acid-value polyester acrylate UV resin. Mix thoroughly at 1000rpm under 30℃ to obtain a UV-curable carboxyl-containing coating. Apply the UV-curable carboxyl-containing coating to a PET film using a roller coating process, achieving a coating thickness of 10μm. Then, apply a 2000mJ / cm² spray. 2 UV curing was performed to prepare a UV-cured PET functional film with a carboxyl-containing coating, which was then stored for later use.

[0087] Example 5

[0088] Reference Figure 1 , Figure 1 This is a schematic diagram of a method for modifying the surface of an electrothermal film, including the following steps:

[0089] S10, surface modification of carbon fiber:

[0090] Weigh 5g of photoinitiator 1-hydroxycyclohexylphenyl ketone, 30g of epoxy acrylate UV resin, 25g of glycidyl methacrylate, and 40g of polyurethane acrylate UV resin. Stir at 1500rpm at 30℃ until homogeneous to obtain an epoxy-containing UV-curable adhesive. Impregnate carbon fibers with the epoxy-containing UV adhesive for dip coating, then apply a 2000mJ / cm² coating solution. 2 UV curing was performed using ultraviolet light to prepare UV-cured epoxy-based composite carbon fiber prepreg, which was then stored for later use.

[0091] S20, surface modification of PET film:

[0092] Weigh 5g of photoinitiator 1-hydroxycyclohexylphenyl ketone, 37g of polyurethane acrylate, 10g of methacrylic acid, and 48g of high-acid-value polyester acrylate UV resin. Mix thoroughly at 1000rpm under 35℃ to obtain a UV-curable carboxyl-containing coating. Apply the UV-curable carboxyl-containing coating to a PET film using a roller coating process, achieving a coating thickness of 15μm. Then, apply a solution of 1500mJ / cm². 2 UV curing was performed to prepare a UV-cured PET functional film with a carboxyl-containing coating, which was then stored for later use.

[0093] Example 6

[0094] Reference Figure 1 , Figure 1 This is a schematic diagram of a method for modifying the surface of an electrothermal film, including the following steps:

[0095] S10, surface modification of carbon fiber:

[0096] Weigh 4g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 30g of epoxy acrylate UV resin, 30g of glycidyl methacrylate, and 36g of polyurethane acrylate UV resin. Stir at 1500rpm at 30℃ until homogeneous to obtain an epoxy-containing UV-curable adhesive. Impregnate carbon fibers with the epoxy-containing UV adhesive for dip coating, then apply a 1000mJ / cm² coating solution. 2 UV curing was performed using ultraviolet light to prepare UV-cured epoxy-based composite carbon fiber prepreg, which was then stored for later use.

[0097] S20, surface modification of PET film:

[0098] Weigh 3g of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone, 35g of polyurethane acrylate, 13g of acrylic acid, and 49g of high-acid-value polyester acrylate UV resin. Mix thoroughly at 1500rpm under 25°C to obtain a UV-curable carboxyl-containing coating. Apply the UV-curable carboxyl-containing coating to a PET film using a roller coating process, achieving a coating thickness of 20μm. Then, apply a 1000mJ / cm² spray. 2 UV curing was performed to prepare a UV-cured PET functional film with a carboxyl-containing coating, which was then stored for later use.

[0099] Application Example 1

[0100] At 120℃, a layer of UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg is combined with a layer of UV-cured carboxyl-containing coating surface-treated PET functional film, and then heated and crosslinked for 1 hour to obtain the PET film layer and carbon fiber layer of the electrothermal film.

[0101] Application Example 2

[0102] At 130℃, two layers of UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg are alternately laminated with two layers of UV-cured carboxyl-containing coating surface-treated PET functional film, and then heated and crosslinked for 2 hours to obtain the PET film layer and carbon fiber layer of the electrothermal film.

[0103] Application Example 3

[0104] At 150℃, a layer of UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg is combined with a layer of UV-cured carboxyl-containing coating surface-treated PET functional film, and then heated and crosslinked for 1 hour to obtain the PET film layer and carbon fiber layer of the electrothermal film.

[0105] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for modifying the surface of an electrothermal film, characterized in that, The electrothermal film comprises a PET film layer and a carbon fiber layer, and the surface modification treatment method for the electrothermal film includes the following steps: Surface modification of carbon fibers: All raw materials constituting the epoxy-containing UV curable adhesive are mixed evenly to obtain the epoxy-containing UV curable adhesive; then the epoxy-containing UV curable adhesive is impregnated with carbon fiber and cured by ultraviolet light to prepare a UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg. The epoxy-containing UV curing adhesive comprises, by weight, the following raw materials: 3-5 parts photoinitiator, 30-40 parts epoxy acrylate UV resin, 20-30 parts epoxy acrylate diluent, and 20-40 parts polyurethane acrylate UV resin. Surface modification of PET film: All raw materials constituting the UV-curable carboxyl-containing coating are mixed evenly to obtain the UV-curable carboxyl-containing coating; then the UV-curable carboxyl-containing coating is coated onto a PET film and cured by ultraviolet light to prepare a UV-curable carboxyl-containing coating surface-treated PET functional film. The UV-curable carboxyl-containing coating comprises, by weight, the following raw materials: 3-5 parts photoinitiator, 5-15 parts carboxyl acrylate monomer, 30-40 parts polyurethane acrylate, and 40-50 parts high acid value polyester acrylate UV resin.

2. The method for modifying the surface of the electrothermal film according to claim 1, characterized in that, At least one layer of the UV-cured epoxy-containing adhesive layer composite carbon fiber prepreg is bonded together with at least one layer of the UV-cured carboxyl-containing coating surface-treated PET functional film, and then heated for crosslinking to complete the preparation of the electrothermal film with respect to the PET film layer and the carbon fiber layer.

3. The method for modifying the surface of the electrothermal film according to claim 1, characterized in that, In the step of surface modification of carbon fibers, the curing energy density of ultraviolet light curing is 1000-2000 mJ / cm². 2 .

4. The method for modifying the surface of the electrothermal film according to claim 1, characterized in that, The photoinitiator comprises at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

5. The method for modifying the surface of the electrothermal film according to claim 1, characterized in that, The epoxy acrylate diluent contains at least one of glycidyl acrylate and glycidyl methacrylate.

6. The method for modifying the surface of the electrothermal film according to claim 1, characterized in that, In the step of surface modification of carbon fiber, the epoxy acrylate UV resin has a vinyl functionality ≥2, a viscosity of 10000-20000 mpa.s at 60°C, a softening point ≥100°C, and an epoxy equivalent of 1000-2000 g / Eq. And / or, the polyurethane acrylate UV resin has a vinyl functionality ≥2, a viscosity of 5000-30000 mpa.s at 60°C, and a glass transition temperature (Tg) ≤50°C.

7. The method for modifying the surface of the electrothermal film according to claim 1, characterized in that, The carboxyacrylate monomer contains at least one of acrylic acid and methacrylic acid.

8. The method for modifying the surface of the electrothermal film according to claim 1, characterized in that, In the step of surface modification of PET film, the polyurethane acrylate has a vinyl functionality ≥2 and a viscosity of 15000-25000 mPa·s at 60°C. And / or, the high acid value polyester acrylate UV resin has a viscosity of 200-5000 mpa.s at 25°C, an acid value of 100-300 mg KOH / g, and a vinyl functionality ≥1.

9. The method for modifying the surface of the electrothermal film according to claim 1, characterized in that, In the step of surface modification of the PET film, the thickness of the UV-cured carboxyl-containing coating applied to the PET film is 10-20 μm.

10. An environmentally friendly electrothermal film obtained by the surface modification treatment method according to any one of claims 1 to 9.

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