TPU composite film with high-performance metal effect and preparation method thereof

Abstract

The invention discloses a TPU (Thermoplastic Polyurethane) composite film with a high-performance metal effect. The TPU composite film comprises a TPU film layer, a PET (Polyethylene Terephthalate) electroplated layer and an adhesive layer which are sequentially arranged from top to bottom, the TPU film layer is formed by coating a TPU composite material, the PET electroplated layer is formed by coating a PET base material with a conductive agent, and the adhesive layer is formed by coating UV elastic resin. Compared with a traditional electroplating material, the composite film has the advantages of being resistant to abrasion, bending and oxidation, not prone to falling off and the like, and is stable in performance and low in manufacturing cost.

Description

Technical Field

[0001] The invention relates to the technical field of TPU composite films, and in particular to a TPU composite film with high-performance metal effect and a preparation method thereof. Background Art

[0002] Thermoplastic polyurethanes (TPU) are a type of elastic polyurethane that can be plasticized by heat. Its molecular structure is a block linear polymer obtained by the polymerization reaction of diisocyanate molecules and polyols. The mechanical properties of TPU materials span a wide range and have the advantages of both rubber and plastic. TPU has excellent low temperature resistance, wear resistance, oil resistance, aging resistance, high rebound rate and other characteristics. It is widely used in industry, life, medical care, military industry and other aspects, and has great application prospects.

[0003] As one of the five major engineering plastics, polyethylene terephthalate (PET) is low in price and has good heat resistance, electrical insulation, chemical resistance, lubricity and excellent mechanical properties. It is now widely used in automotive parts and electronic and electrical fields.

[0004] As people have higher and higher requirements for appearance, they have put forward higher requirements for the coating performance of materials. Traditional decorative plastic electroplating substrates generally use ABS / PC or ABS; however, ABS has a large hardness, and it is difficult to fit stably at the corners when attached, and the heating temperature is high, which is not conducive to thermal bonding to the surface of shoes or bags, limiting its application range; for this reason, relevant technicians have modified ABS and TPU by blending to form ABS / TPU composites, combined the performance of the two, and then electroplated to form ABS / TPU blend films. For example, Chinese patent CN117601541A discloses a colored multi-layer electroplated TPU film and its preparation method and application, by melt-mixing modified carbon nanotubes with waste ABS, and adding sorbic acid, calcium carbonate and vulcanizing agent, the crosslinking density of the TPU film material is further increased. The synergistic effect of these modified components also significantly improves the compatibility of the waste ABS mixture with other components in the TPU system, thereby significantly improving the mechanical properties of the TPU film material. However, compared with TPU film, the adhesion and softness of ABS / TPU blend film are reduced, and compared with the electroplating effect of ABS film, the electroplating effect of ABS / TPU blend film is also reduced, and the electroplating layer on the surface is easy to fall off. The surface of TPU film is difficult to electroplate, and PET is a non-conductor. To electroplate it, a conductive layer must be coated on the surface of PET. The formation of the conductive layer requires roughening, sensitization, activation and chemical plating. Roughening is to etch away metal oxides through oxidation reaction and activate the workpiece to improve the electroplating bonding force. Summary of the invention

[0005] In view of this, the purpose of the present invention is to overcome the problems existing in the prior art and provide a TPU composite film with high-performance metal effect. Compared with traditional electroplating materials, the composite film has the characteristics of wear resistance, bending resistance, oxidation resistance, and not easy to fall off, and has stable performance and low production cost.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] A TPU composite film with high-performance metal effect comprises a TPU film layer, a PET electroplating layer and an adhesive layer which are arranged in sequence from top to bottom; the TPU film layer is formed by coating a TPU composite material, the PET electroplating layer is a PET electroplating layer formed by coating a conductive agent on a PET substrate, and the adhesive layer is formed by coating a UV elastic resin.

[0008] Preferably, the TPU composite material comprises the following raw materials in parts by weight: 40-60 parts of TPU, 40-60 parts of PA6, 1-3 parts of modified graphene, 0.5-2 parts of silicon dioxide, 1-5 parts of compatibilizer and 1-5 parts of lubricant. By blending TPU and PA6, TPU and PA6 have excellent compatibility, which can significantly improve the toughness, wear resistance and chemical resistance of the TPU composite material while reducing the amount of TPU used.

[0009] Preferably, the preparation method of the modified graphene is: dispersing graphene in a mixed solution of dimethylformamide and KH-550 coupling agent, adding acetic acid solution for dispersion after vacuum filtration, solid collection and multiple washing, adding boron nitride, condensing and refluxing at 70-80°C for 5-8h, filtering, washing and drying to obtain modified graphene. Boron nitride is a two-dimensional inorganic material with excellent chemical stability and mechanical properties, which is formed by covalently bonded B elements and N primary colors stacked by weak van der Waals forces. Graphene is modified by boron nitride and the modified graphene is added to the TPU composite material to improve the chemical resistance and aging resistance of the TPU composite material.

[0010] Preferably, the silicon dioxide is hollow spherical silicon dioxide, and the diameter of the silicon dioxide is 200-250nm; the compatibilizer is selected from one or more of stearic acid monoglyceride, tristearic acid glyceride and pentaerythritol stearate; the lubricant is selected from one or more of butyl stearate or microcrystalline wax. Hollow spherical silicon dioxide is added to the TPU composite film. Silicon dioxide has high hardness and wear resistance, can absorb ultraviolet rays, and can effectively improve the tensile strength, impact strength and ultraviolet resistance of TPU. At the same time, silicon dioxide has stable silicon oxygen tetrahedron, which can improve the chemical resistance of TPU.

[0011] Preferably, the preparation method of the TPU composite material comprises the following steps: (1) adding TPU, PA6, modified graphene and silicon dioxide into a blender according to weight parts, and blending at a speed of 100-150 rpm / min for 15-30 minutes; (2) adding a compatibilizer and a lubricant into the blender according to weight parts, blending at a speed of 100-150 rpm / min for 5-10 minutes, and extruding and granulating to obtain a TPU film layer.

[0012] Preferably, the conductive agent comprises 5-20 parts of metal powder and 1-30 parts of hyperbranched polymer.

[0013] Preferably, the metal powder is one or more of aluminum powder, copper powder, zinc powder and iron powder, and the average particle size of the metal powder is 1-100 nm; the hyperbranched polymer is PAMAM, PPI or PLL.

[0014] Preferably, the preparation method of the PET electroplating layer comprises the following steps: (1) first dissolving metal powder and hyperbranched polymer in a methanol solution to form a varnish; (2) coating the varnish on the surface of the PET substrate, evaporating and drying the varnish on the surface to obtain the PET electroplating layer. If the average particle size of the metal powder is too high, the surface area of ​​the metal powder will be reduced, resulting in the inability of the metal powder to combine with the hyperbranched polymer to form a complete complex. Hyperbranched polymers are a type of highly branched three-dimensional macromolecules, and their viscosity does not change with the increase of molecular weight. By utilizing their rich terminal functional groups (ester bonds and double bonds), the metal ions of the metal powder are attached to or coordinated to the hyperbranched polymer to form a complex. In addition, the terminal functional groups contain a large number of ester bonds, which makes them have good dispersibility and good compatibility with the metal powder.

[0015] Preferably, the UV elastic resin comprises the following raw materials in parts by weight: 20-50 parts of polyurethane acrylate prepolymer, 50-60 parts of active monomer, 2-5 parts of photoinitiator, 1-5 parts of coupling agent and 40-50 parts of active diluent.

[0016] Preferably, the active monomers include hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate, and the weight ratio of hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate is 1:(0.5-1):(0.4-0.6):(0.5-0.6); the photoinitiator is selected from one or more of α,α-dimethylbenzil ketal, α,α-diethoxyacetophenone, 2-hydroxy-2-methyl-phenylacetone-1 and 1-hydroxy-cyclohexyl benzophenone; the coupling agent is selected from one or more of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy) silane, methyl trimethoxysilane, 3-ureapropyl triethoxysilane and diphenyl dimethoxysilane; the active diluent is selected from one or more of isobornyl acrylate, N,N-dimethylacrylamide and tris(2-hydroxyethyl)isocyanuric acid triacrylate. Hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate are used as active monomers. The short and long chains and different ring structures in their structures react with the polyurethane acrylate prepolymer to cross-link, reducing the volume shrinkage of the UV adhesive coating during the curing process, while reducing the cross-linking density and curing time of the adhesive layer, thereby improving the adhesion of the adhesive layer.

[0017] Preferably, the preparation method of the UV elastic resin comprises the following steps: (1) adding polyurethane acrylate prepolymer, active monomer, coupling agent and active diluent into a blender according to weight parts, and blending for 0.5-2h; (2) adding a photoinitiator into the blender, blending for 2-5h under -0.1MPa conditions, defoaming and discharging to obtain a UV adhesive coating.

[0018] Preferably, the thickness of the TPU film layer is 0.1-3 mm, the thickness of the PET electroplated layer is 1-5 mm, and the thickness of the adhesive layer is 0.001-0.005 mm.

[0019] A method for preparing the above-mentioned TPU composite film comprises the following steps:

[0020] (1) coating the conductive agent on the upper surface of the PET substrate, scraping and leveling it, and evaporating and drying the conductive agent;

[0021] (2) using a plasma process to perform electroplating to form a PET electroplating layer;

[0022] (3) applying a UV adhesive coating on the surface of the PET electroplating layer coated with a conductive agent, scraping and leveling it, and curing it with ultraviolet light through a UV machine to form an adhesive layer;

[0023] (4) The TPU composite material is compounded with the surface of the PET electroplating layer which is not coated with a conductive agent under high temperature and high pressure conditions to obtain a TPU composite film.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The TPU composite film of the present invention has a simple structure, adopts a structure of a TPU film layer, a PET electroplating layer and an adhesive layer, utilizes the TPU composite material to improve the elasticity and impact resistance of the composite film, and coats the conductive agent on the PET substrate to improve the metallic luster and bonding force of the composite film. The composite film has excellent adhesion, softness, oxidation resistance and metallic luster, and at the same time fills the defect that TPU cannot be electroplated;

[0026] (2) The preparation method of the TPU composite film of the present invention has simple process, easy operation and control, and can be industrialized for large-scale production. The prepared TPU composite film has stable performance, and has the characteristics of wear resistance, bending resistance, oxidation resistance, and not easy to fall off, and has excellent comprehensive performance. DETAILED DESCRIPTION

[0027] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the embodiments, but the contents mentioned in the embodiments are not intended to limit the present invention.

[0028] Example 1

[0029] A TPU composite film with high-performance metal effect comprises a TPU film layer, a PET electroplating layer and an adhesive layer which are arranged in sequence from top to bottom; the TPU film layer is formed by coating a TPU composite material, the PET electroplating layer is a PET electroplating layer formed by coating a conductive agent on a PET substrate, and the adhesive layer is formed by coating a UV elastic resin.

[0030] Preferably, the TPU composite material comprises the following raw materials in parts by weight: 40 parts of TPU, 40 parts of PA6, 1 part of modified graphene, 0.5 parts of silicon dioxide, 1 part of compatibilizer and 1 part of lubricant.

[0031] Preferably, the preparation method of the modified graphene is: dispersing graphene in a mixed solution of dimethylformamide and KH-550 coupling agent, adding acetic acid solution to disperse after vacuum filtration, solid collection and multiple washing, and then adding boron nitride, condensing and refluxing at 70°C for 5h, filtering, washing and drying to obtain modified graphene.

[0032] Preferably, the silicon dioxide is hollow spherical silicon dioxide, and the diameter of the silicon dioxide is 200 nm; the compatibilizer is stearic acid monoglyceride; and the lubricant is butyl stearate.

[0033] Preferably, the preparation method of the TPU composite material comprises the following steps: (1) adding TPU, PA6, modified graphene and silicon dioxide into a blender according to weight parts, and blending at a speed of 100 rpm / min for 15 minutes; (2) adding a compatibilizer and a lubricant into the blender according to weight parts, blending at a speed of 100 rpm / min for 5 minutes, and extruding and granulating to obtain a TPU film layer.

[0034] Preferably, the conductive agent comprises 5 parts of metal powder and 5 parts of hyperbranched polymer.

[0035] Preferably, the metal powder is aluminum powder, and the average particle size of the metal powder is 5 nm; and the hyperbranched polymer is PAMAM.

[0036] Preferably, the method for preparing the PET electroplating layer comprises the following steps: (1) first dissolving metal powder and hyperbranched polymer in a methanol solution to form a varnish; (2) coating the varnish on the surface of the PET substrate, evaporating and drying the varnish on the surface to obtain the PET electroplating layer.

[0037] Preferably, the UV elastic resin comprises the following raw materials in parts by weight: 20 parts of polyurethane acrylate prepolymer, 50 parts of active monomer, 2 parts of photoinitiator, 1 part of coupling agent and 40 parts of active diluent.

[0038] Preferably, the active monomers include hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate, and the weight ratio of hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate is 1:0.5:0.4:0.5; the photoinitiator is α, α-dimethylbenzil ketal; the coupling agent is vinyl triethoxysilane; and the active diluent is isobornyl acrylate.

[0039] Preferably, the preparation method of the UV elastic resin comprises the following steps: (1) adding the polyurethane acrylate prepolymer, the active monomer, the coupling agent and the active diluent into a blender according to parts by weight, and blending for 0.5 h; (2) adding the photoinitiator into the blender, blending for 2 h at -0.1 MPa, defoaming and discharging to obtain the UV elastic resin.

[0040] Preferably, the thickness of the TPU film layer is 0.1 mm, the thickness of the PET electroplated layer is 1 mm, and the thickness of the adhesive layer is 0.001 mm.

[0041] A method for preparing the above-mentioned TPU composite film comprises the following steps:

[0042] (1) coating the conductive agent on the upper surface of the PET substrate, scraping and leveling it, and evaporating and drying the conductive agent;

[0043] (2) using a plasma process to perform electroplating to form a PET electroplating layer;

[0044] (3) applying a UV adhesive coating on the surface of the PET electroplating layer coated with a conductive agent, scraping and leveling it, and curing it with ultraviolet light through a UV machine to form an adhesive layer;

[0045] (4) The TPU composite material is compounded with the surface of the PET electroplating layer which is not coated with a conductive agent under high temperature and high pressure conditions to obtain a TPU composite film.

[0046] Example 2

[0047] A TPU composite film with high-performance metal effect comprises a TPU film layer, a PET electroplating layer and an adhesive layer which are arranged in sequence from top to bottom; the TPU film layer is formed by coating a TPU composite material, the PET electroplating layer is a PET electroplating layer formed by coating a conductive agent on a PET substrate, and the adhesive layer is formed by coating a UV elastic resin.

[0048] Preferably, the TPU composite material comprises the following raw materials in parts by weight: 60 parts of TPU, 60 parts of PA6, 3 parts of modified graphene, 2 parts of silicon dioxide, 5 parts of compatibilizer and 5 parts of lubricant.

[0049] Preferably, the preparation method of the modified graphene is: dispersing graphene in a mixed solution of dimethylformamide and KH-550 coupling agent, adding acetic acid solution to disperse after vacuum filtration, solid collection and multiple washing, and then adding boron nitride, condensing and refluxing at 80°C for 8h, filtering, washing and drying to obtain modified graphene.

[0050] Preferably, the silicon dioxide is hollow spherical silicon dioxide, and the diameter of the silicon dioxide is 250 nm; the compatibilizer is tristearate; and the lubricant is microcrystalline paraffin.

[0051] Preferably, the preparation method of the TPU composite material comprises the following steps: (1) adding TPU, PA6, modified graphene and silica into a blender according to weight parts, and blending at a speed of 150 rpm / min for 30 minutes; (2) adding a compatibilizer and a lubricant into the blender according to weight parts, blending at a speed of 150 rpm / min for 10 minutes, and extruding and granulating to obtain a TPU film layer.

[0052] Preferably, the conductive agent comprises 20 parts of metal powder and 30 parts of hyperbranched polymer.

[0053] Preferably, the metal powder is copper powder, and the average particle size of the metal powder is 100 nm; and the hyperbranched polymer is PPI.

[0054] Preferably, the method for preparing the PET electroplating layer comprises the following steps: (1) first dissolving metal powder and hyperbranched polymer in a methanol solution to form a varnish; (2) coating the varnish on the surface of the PET substrate, evaporating and drying the varnish on the surface to obtain the PET electroplating layer.

[0055] Preferably, the UV elastic resin comprises the following raw materials in parts by weight: 50 parts of polyurethane acrylate prepolymer, 60 parts of active monomer, 5 parts of photoinitiator, 5 parts of coupling agent and 50 parts of active diluent.

[0056] Preferably, the active monomers include hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate, and the weight ratio of hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate is 1:1:0.6:0.6; the photoinitiator is α,α-diethoxyacetophenone; the coupling agent is vinyltrimethoxysilane; and the active diluent is N,N-dimethylacrylamide.

[0057] Preferably, the preparation method of the UV elastic resin comprises the following steps: (1) adding polyurethane acrylate prepolymer, active monomer, coupling agent and active diluent into a blender according to weight parts, and blending for 2 hours; (2) adding a photoinitiator into the blender, blending for 5 hours under -0.1 MPa conditions, defoaming and discharging to obtain a UV elastic resin.

[0058] Preferably, the thickness of the TPU film layer is 3 mm, the thickness of the PET electroplated layer is 5 mm, and the thickness of the adhesive layer is 0.005 mm.

[0059] A method for preparing the above-mentioned TPU composite film comprises the following steps:

[0060] (1) coating the conductive agent on the upper surface of the PET substrate, scraping and leveling it, and evaporating and drying the conductive agent;

[0061] (2) using a plasma process to perform electroplating to form a PET electroplating layer;

[0062] (3) applying a UV adhesive coating on the surface of the PET electroplating layer coated with a conductive agent, scraping and leveling it, and curing it with ultraviolet light through a UV machine to form an adhesive layer;

[0063] (4) The TPU composite material is compounded with the surface of the PET electroplating layer which is not coated with a conductive agent under high temperature and high pressure conditions to obtain a TPU composite film.

[0064] Example 3

[0065] A TPU composite film with high-performance metal effect comprises a TPU film layer, a PET electroplating layer and an adhesive layer which are arranged in sequence from top to bottom; the TPU film layer is formed by coating a TPU composite material, the PET electroplating layer is a PET electroplating layer formed by coating a conductive agent on a PET substrate, and the adhesive layer is formed by coating a UV elastic resin.

[0066] Preferably, the TPU composite material comprises the following raw materials in parts by weight: 50 parts of TPU, 50 parts of PA6, 2 parts of modified graphene, 1 part of silicon dioxide, 3 parts of compatibilizer and 3 parts of lubricant.

[0067] Preferably, the preparation method of the modified graphene is: dispersing graphene in a mixed solution of dimethylformamide and KH-550 coupling agent, adding acetic acid solution to disperse after vacuum filtration, solid collection and multiple washing, and then adding boron nitride, condensing and refluxing at 75°C for 6h, filtering, washing and drying to obtain modified graphene.

[0068] Preferably, the silicon dioxide is hollow spherical silicon dioxide, and the diameter of the silicon dioxide is 225 nm; the compatibilizer is pentaerythritol stearate; and the lubricant is butyl stearate.

[0069] Preferably, the preparation method of the TPU composite material comprises the following steps: (1) adding TPU, PA6, modified graphene and silica into a blender according to weight parts, and blending at a speed of 125 rpm / min for 20 minutes; (2) adding a compatibilizer and a lubricant into the blender according to weight parts, blending at a speed of 125 rpm / min for 8 minutes, and extruding and granulating to obtain a TPU film layer.

[0070] Preferably, the conductive agent comprises 10 parts of metal powder and 15 parts of hyperbranched polymer.

[0071] Preferably, the metal powder is zinc powder, and the average particle size of the metal powder is 50 nm; and the hyperbranched polymer is PLL.

[0072] Preferably, the method for preparing the PET electroplating layer comprises the following steps: (1) first dissolving metal powder and hyperbranched polymer in a methanol solution to form a varnish; (2) coating the varnish on the surface of the PET substrate, evaporating and drying the varnish on the surface to obtain the PET electroplating layer.

[0073] Preferably, the UV elastic resin comprises the following raw materials in parts by weight: 35 parts of polyurethane acrylate prepolymer, 55 parts of active monomer, 3 parts of photoinitiator, 3 parts of coupling agent and 45 parts of active diluent.

[0074] Preferably, the active monomers include hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate, and the weight ratio of hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate is 1:0.75:0.5:0.55; the photoinitiator is 2-hydroxy-2-methyl-phenylacetone-1; the coupling agent is vinyl tri(β-methoxyethoxy) silane; and the active diluent is tri(2-hydroxyethyl)isocyanuric acid triacrylate.

[0075] Preferably, the preparation method of the UV elastic resin comprises the following steps: (1) adding polyurethane acrylate prepolymer, active monomer, coupling agent and active diluent into a blender according to weight parts, and blending for 1 hour; (2) adding a photoinitiator into the blender, blending for 3 hours under -0.1 MPa conditions, defoaming and discharging to obtain a UV elastic resin.

[0076] Preferably, the thickness of the TPU film layer is 1 mm, the thickness of the PET electroplated layer is 3 mm, and the thickness of the adhesive layer is 0.003 mm.

[0077] A method for preparing the above-mentioned TPU composite film comprises the following steps:

[0078] (1) coating the conductive agent on the upper surface of the PET substrate, scraping and leveling it, and evaporating and drying the conductive agent;

[0079] (2) using a plasma process to perform electroplating to form a PET electroplating layer;

[0080] (3) applying a UV adhesive coating on the surface of the PET electroplating layer coated with a conductive agent, scraping and leveling it, and curing it with ultraviolet light through a UV machine to form an adhesive layer;

[0081] (4) The TPU composite material is compounded with the surface of the PET electroplating layer which is not coated with a conductive agent under high temperature and high pressure conditions to obtain a TPU composite film.

[0082] Example 4

[0083] A TPU composite film with high-performance metal effect comprises a TPU film layer, a PET electroplating layer and an adhesive layer which are arranged in sequence from top to bottom; the TPU film layer is formed by coating a TPU composite material, the PET electroplating layer is a PET electroplating layer formed by coating a conductive agent on a PET substrate, and the adhesive layer is formed by coating a UV elastic resin.

[0084] Preferably, the TPU composite material comprises the following raw materials in parts by weight: 55 parts of TPU, 45 parts of PA6, 2 parts of modified graphene, 1 part of silicon dioxide, 2 parts of compatibilizer and 3 parts of lubricant.

[0085] Preferably, the preparation method of the modified graphene is: dispersing graphene in a mixed solution of dimethylformamide and KH-550 coupling agent, adding acetic acid solution to disperse after vacuum filtration, solid collection and multiple washing, and then adding boron nitride, condensing and refluxing at 75°C for 6h, filtering, washing and drying to obtain modified graphene.

[0086] Preferably, the silicon dioxide is hollow spherical silicon dioxide, and the diameter of the silicon dioxide is 200 nm; the compatibilizer is stearic acid monoglyceride; and the lubricant is butyl stearate.

[0087] Preferably, the preparation method of the TPU composite material comprises the following steps: (1) adding TPU, PA6, modified graphene and silica into a blender according to weight parts, and blending at a speed of 100 rpm / min for 15 minutes; (2) adding a compatibilizer and a lubricant into the blender according to weight parts, blending at a speed of 100 rpm / min for 8 minutes, and extruding and granulating to obtain a TPU film layer.

[0088] Preferably, the conductive agent comprises 5-20 parts of metal powder and 1-30 parts of hyperbranched polymer.

[0089] Preferably, the metal powder is iron powder, and the average particle size of the metal powder is 55 nm; and the hyperbranched polymer is PPI.

[0090] Preferably, the method for preparing the PET electroplating layer comprises the following steps: (1) first dissolving metal powder and hyperbranched polymer in a methanol solution to form a varnish; (2) coating the varnish on the surface of the PET substrate, evaporating and drying the varnish on the surface to obtain the PET electroplating layer.

[0091] Preferably, the UV elastic resin comprises the following raw materials in parts by weight: 45 parts of polyurethane acrylate prepolymer, 50 parts of active monomer, 4 parts of photoinitiator, 3 parts of coupling agent and 45 parts of active diluent.

[0092] Preferably, the active monomers include hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate, and the weight ratio of hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate is 1:0.5:0.5:0.5; the photoinitiator is 1-hydroxy-cyclohexyl benzophenone; the coupling agent is methyltrimethoxysilane; and the active diluent is isobornyl acrylate.

[0093] Preferably, the preparation method of the UV elastic resin comprises the following steps: (1) adding polyurethane acrylate prepolymer, active monomer, coupling agent and active diluent into a blender according to weight parts, and blending for 1 hour; (2) adding a photoinitiator into the blender, blending for 3 hours under -0.1 MPa conditions, defoaming and discharging to obtain a UV elastic resin.

[0094] Preferably, the thickness of the TPU film layer is 2 mm, the thickness of the PET electroplated layer is 2 mm, and the thickness of the adhesive layer is 0.002 mm.

[0095] A method for preparing the above-mentioned TPU composite film comprises the following steps:

[0096] (1) coating the conductive agent on the upper surface of the PET substrate, scraping and leveling it, and evaporating and drying the conductive agent;

[0097] (2) using a plasma process to perform electroplating to form a PET electroplating layer;

[0098] (3) applying a UV adhesive coating on the surface of the PET electroplating layer coated with a conductive agent, scraping and leveling it, and curing it with ultraviolet light through a UV machine to form an adhesive layer;

[0099] (4) The TPU composite material is compounded with the surface of the PET electroplating layer which is not coated with a conductive agent under high temperature and high pressure conditions to obtain a TPU composite film.

[0100] Example 5

[0101] A TPU composite film with high-performance metal effect comprises a TPU film layer, a PET electroplating layer and an adhesive layer which are arranged in sequence from top to bottom; the TPU film layer is formed by coating a TPU composite material, the PET electroplating layer is a PET electroplating layer formed by coating a conductive agent on a PET substrate, and the adhesive layer is formed by coating a UV elastic resin.

[0102] Preferably, the TPU composite material comprises the following raw materials in parts by weight: 45 parts of TPU, 50 parts of PA6, 3 parts of modified graphene, 2 parts of silicon dioxide, 1 part of compatibilizer and 2 parts of lubricant.

[0103] Preferably, the preparation method of the modified graphene is: dispersing graphene in a mixed solution of dimethylformamide and KH-550 coupling agent, adding acetic acid solution to disperse after vacuum filtration, solid collection and multiple washing, and then adding boron nitride, condensing and refluxing at 78°C for 7h, filtering, washing and drying to obtain modified graphene.

[0104] Preferably, the silicon dioxide is hollow spherical silicon dioxide, and the diameter of the silicon dioxide is 250 nm; the compatibilizer is tristearate; and the lubricant is microcrystalline paraffin.

[0105] Preferably, the preparation method of the TPU composite material comprises the following steps: (1) adding TPU, PA6, modified graphene and silica into a blender according to weight parts, and blending at a speed of 120 rpm / min for 25 minutes; (2) adding a compatibilizer and a lubricant into the blender according to weight parts, blending at a speed of 130 rpm / min for 7 minutes, and extruding and granulating to obtain a TPU film layer.

[0106] Preferably, the conductive agent comprises 5-20 parts of metal powder and 1-30 parts of hyperbranched polymer.

[0107] Preferably, the metal powder is aluminum powder, and the average particle size of the metal powder is 45 nm; and the hyperbranched polymer is PAMAM.

[0108] Preferably, the method for preparing the PET electroplating layer comprises the following steps: (1) first dissolving metal powder and hyperbranched polymer in a methanol solution to form a varnish; (2) coating the varnish on the surface of the PET substrate, evaporating and drying the varnish on the surface to obtain the PET electroplating layer.

[0109] Preferably, the UV elastic resin comprises the following raw materials in parts by weight: 30 parts of polyurethane acrylate prepolymer, 52 parts of active monomer, 4 parts of photoinitiator, 3 parts of coupling agent and 45 parts of active diluent.

[0110] Preferably, the active monomers include hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate, and the weight ratio of hydroxyethyl methacrylate, benzyl methacrylate, lauryl acrylate and isobornyl acrylate is 1:0.8:0.4:0.5; the photoinitiator is 1-hydroxy-cyclohexyl benzophenone; the coupling agent is methyltrimethoxysilane; and the active diluent is N,N-dimethylacrylamide.

[0111] Preferably, the preparation method of the UV elastic resin comprises the following steps: (1) adding polyurethane acrylate prepolymer, active monomer, coupling agent and active diluent into a blender according to weight parts, and blending for 1 hour; (2) adding a photoinitiator into the blender, blending for 4 hours under -0.1 MPa conditions, defoaming and discharging to obtain a UV elastic resin.

[0112] Preferably, the thickness of the TPU film layer is 1 mm, the thickness of the PET electroplated layer is 3 mm, and the thickness of the adhesive layer is 0.004 mm.

[0113] A method for preparing the above-mentioned TPU composite film comprises the following steps:

[0114] (1) coating the conductive agent on the upper surface of the PET substrate, scraping and leveling it, and evaporating and drying the conductive agent;

[0115] (2) using a plasma process to perform electroplating to form a PET electroplating layer;

[0116] (3) applying a UV adhesive coating on the surface of the PET electroplating layer coated with a conductive agent, scraping and leveling it, and curing it with ultraviolet light through a UV machine to form an adhesive layer;

[0117] (4) The TPU composite material is compounded with the surface of the PET electroplating layer which is not coated with a conductive agent under high temperature and high pressure conditions to obtain a TPU composite film.

[0118] Comparative Example 1

[0119] Compared with Example 5, the difference is that: Comparative Example 1 uses graphene oxide, and the other raw materials, components, and preparation steps are the same.

[0120] Comparative Example 2

[0121] Compared with Example 5, the difference is that: Comparative Example 2 uses independent metal powder and hyperbranched polymer, and the other raw materials, components and preparation steps are the same.

[0122] Comparative Example 3

[0123] Compared with Example 5, the difference is that: Comparative Example 3 does not use PA6, and the other raw materials, components, and preparation steps are the same.

[0124] Comparative Example 4

[0125] Compared with Example 5, the difference is that the active monomer in Comparative Example 4 is hydroxyethyl methacrylate, and the other raw materials, components and preparation steps are the same.

[0126] Adhesion test: According to the coating test method of GB / T9286-88, the adhesive layer of the TPU composite film in Examples 1-5 and Comparative Examples 1-4 was bonded to glass for testing.

[0127] Peel strength decay rate: According to GB / T2791-1995 standard, the adhesive layer in the TPU composite film in Examples 1-5 and Comparative Examples 1-4 was bonded to glass for testing. After aging in a high temperature and high temperature humidity test box, the T-peel strength before and after aging was tested. Curing conditions: 250W ultraviolet lamp irradiation, lamp distance of 4cm, high temperature and high humidity test conditions of 85℃ / RH85%, test period of 120h, peel strength decay rate (%) = (T-peel strength before aging - T-peel strength after aging) / T-peel strength before aging * 100%.

[0128] Average gloss: According to ASTM D2457-13 standard, the TPU composite films in Examples 1-5 and Comparative Examples 1-4 were tested, and 10 test points were selected from the surface of the TPU film layer in the TPU composite film using a universal 60° mirror gloss tester.

[0129] Wear resistance: According to BG / T1768-2006 standard, the TPU composite films in Examples 1-5 and Comparative Examples 1-4 were tested, with a rubber grinding wheel load of 1 kg and a friction coefficient of 200 cycles, and the mass loss was calculated.

[0130]

[0131] As can be seen from the above table, the TPU composite films prepared in Examples 1-5 have good adhesion, peel strength, wear resistance and glossiness.

[0132] By comparing Example 5 and Comparative Example 1, it can be seen that the present application uses boron nitride to modify graphene, and adding the modified graphene to the TPU composite material can improve the impact resistance of the TPU composite material and enhance the mechanical properties of the TPU film layer.

[0133] By comparing Example 5 and Comparative Example 2, it can be seen that the present application performs a composite treatment on the metal powder and the hyperbranched polymer and coats it on the surface of the PET substrate, thereby improving the fluidity and compatibility of the metal powder in the PET electroplating layer, improving the electroplating performance of the PET substrate, and ensuring the glossiness of the PET electroplating layer.

[0134] By comparing Example 5 and Comparative Example 3, it can be seen that the present application adopts the blending of TPU and PA6, which improves the compatibility and toughness of the TPU composite material, so that the TPU film layer has the advantages of wear resistance, impact resistance and stable performance.

[0135] By comparing Example 5 and Comparative Example 4, it can be seen that the present application adopts a compounded active monomer, and the side chain structure of the active monomer undergoes a cross-linking reaction with the polyurethane acrylate prepolymer, which shortens the curing time of the UV adhesive coating and improves the adhesion of the adhesive layer.

[0136] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A TPU composite film with high performance metal effect, characterized in that: It includes a TPU film layer, a PET electroplating layer and an adhesive layer arranged in sequence from top to bottom; the TPU film layer is coated with a TPU composite material, the PET electroplating layer is a PET electroplating layer formed by coating a conductive agent on a PET substrate, and the adhesive layer is coated with a UV elastic resin.

2. The TPU composite film with high performance metal effect according to claim 1, characterized in that: The TPU composite material comprises the following raw materials in parts by weight: 40-60 parts of TPU, 40-60 parts of PA6, 1-3 parts of modified graphene, 0.5-2 parts of silicon dioxide, 1-5 parts of a compatibilizer and 1-5 parts of a lubricant.

3. The TPU composite film with high performance metal effect according to claim 2, characterized in that: The preparation method of the modified graphene is as follows: dispersing the graphene in a mixed solution of dimethylformamide and a KH-550 coupling agent, performing vacuum filtration, solid collection and multiple washing, adding an acetic acid solution for dispersion, adding boron nitride, condensing and refluxing at 70-80° C. for 5-8 hours, filtering, washing and drying to obtain the modified graphene.

4. The TPU composite film with high performance metal effect according to claim 2, characterized in that: The preparation method of the TPU composite material comprises the following steps: (1) adding TPU, PA6, modified graphene and silicon dioxide into a blender according to weight parts, and blending at a speed of 100-150 rpm / min for 15-30 minutes; (2) adding a compatibilizer and a lubricant into the blender according to weight parts, blending at a speed of 100-150 rpm / min for 5-10 minutes, and extruding and granulating to obtain a TPU film layer.

5. The TPU composite film with high performance metal effect according to claim 1, characterized in that: The conductive agent includes 5-20 parts of metal powder and 1-30 parts of hyperbranched polymer.

6. The TPU composite film with high performance metal effect according to claim 5, characterized in that: The preparation method of the PET electroplating layer comprises the following steps: (1) first dissolving metal powder and hyperbranched polymer in a methanol solution to form a varnish; (2) coating the varnish on the surface of the PET substrate, evaporating and drying the varnish on the surface to obtain the PET electroplating layer.

7. The TPU composite film with high performance metal effect according to claim 1, characterized in that: The UV elastic resin comprises the following raw materials in parts by weight: 20-50 parts of polyurethane acrylate prepolymer, 50-60 parts of active monomer, 2-5 parts of photoinitiator, 1-5 parts of coupling agent and 40-50 parts of active diluent.

8. The TPU composite film with high performance metal effect according to claim 7, characterized in that: The preparation method of the UV elastic resin comprises the following steps: (1) adding polyurethane acrylate prepolymer, active monomer, coupling agent and active diluent into a blender according to weight parts, and blending for 0.5-2 hours; (2) adding a photoinitiator into the blender, blending for 2-5 hours under -0.1 MPa conditions, defoaming and discharging to obtain the UV elastic resin.

9. The TPU composite film with high performance metal effect according to claim 1, characterized in that: The thickness of the TPU film layer is 0.1-3 mm, the thickness of the metal layer is 0.01-0.05 mm, and the thickness of the adhesive layer is 0.001-0.005 mm.

10. A method for preparing a TPU composite film according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) coating the conductive agent on the upper surface of the PET substrate, scraping and leveling it, and evaporating and drying the conductive agent; (2) using a plasma process to perform electroplating to form a PET electroplating layer; (3) applying a UV adhesive coating on the surface of the PET electroplating layer coated with a conductive agent, scraping and smoothing it, and curing it with ultraviolet light through a UV machine to form an adhesive layer; (4) The TPU composite material is compounded with the surface of the PET electroplating layer which is not coated with a conductive agent under high temperature and high pressure conditions to obtain a TPU composite film.

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