Wiredrawing aluminum laminated film and preparation method thereof

Abstract

The invention discloses a wiredrawing aluminum laminated film and a preparation method thereof, and belongs to the field of films. The wiredrawing aluminized film comprises a wiredrawing base material, a polyurethane coating and an aluminized layer which are arranged in sequence, the polyurethane coating is formed by curing a polyurethane coating, the polyurethane coating is subjected to plasma surface treatment, and the polyurethane coating comprises a waterborne polyurethane dispersion liquid, a diluent and water which are compounded according to the weight ratio of 1: (0.5-1): (0.5-1); the waterborne polyurethane dispersion liquid is prepared from the following raw materials in parts by weight: 2-8 parts of double-end hydroxypropyl polysiloxane; 15 to 20 parts of polyether polyol; 15 to 20 parts of diisocyanate; 3-6 parts of a chain extender; 5-9 parts of a hydroxyl acrylate monomer; 2-5 parts of an acrylate monomer; 1 to 3 parts of single-ended vinyl polysiloxane; and 80-90 parts of water. The method has the advantages that the adhesive force of the aluminum layer is improved, and the durability of the wiredrawing aluminum laminated film is improved.

Description

Technical Field

[0001] The present application relates to the field of thin films, and in particular to a brushed aluminum-plated film and a preparation method thereof. Background Art

[0002] Brushed aluminum film is a common decorative film that imitates the metallic luster and brushed texture of brushed aluminum materials. Therefore, it can replace metal sheets in appearance decoration. Brushed aluminum film has gradually been used in various fields of daily life, such as TV panels, refrigerator door panels, computer panels and other surface decorations of various household appliances, and has a wide range of uses in the packaging field, such as electronic equipment, beverage bottles, cosmetics, etc. Brushed aluminum film can protect the product surface from scratches or pollution, and can improve the visual effect of the product.

[0003] The base materials of existing brushed aluminized films are usually PET, PVC and CPP, among which PET is most commonly used for brushed aluminized films due to its stable and durable characteristics. First, the PET film is mechanically drawn under the treatment of a drawing device to form a drawing surface on one side of the PET film, and then the aluminum layer is fixedly attached to the drawing surface by vacuum aluminum plating to form a brushed aluminized film.

[0004] However, since the brushed aluminum-plated film substrate is subjected to brushing treatment, the sufficient contact between the aluminum layer and the substrate is affected, resulting in poor adhesion of the aluminum layer, which affects the durability of the brushed aluminum-plated film. Summary of the invention

[0005] In order to improve the adhesion of the aluminum layer and enhance the durability of the brushed aluminum-plated film, the present application provides a brushed aluminum-plated film and a preparation method thereof.

[0006] In the first aspect, the present application provides a brushed aluminum-plated film adopting the following technical solution: A brushed aluminum-plated film, comprising a brushed substrate, a polyurethane coating and an aluminum-plated layer arranged in sequence, wherein the polyurethane coating is formed by curing a polyurethane coating, the polyurethane coating is subjected to plasma surface treatment, and the polyurethane coating comprises an aqueous polyurethane dispersion, a diluent and water in a weight ratio of 1:(0.6-1):(0.6-1); The aqueous polyurethane dispersion is prepared from the following raw materials in parts by weight: 2-8 parts of double-terminal hydroxypropyl polysiloxane; 15-20 parts of polyether polyol; 15-20 parts of diisocyanate; 3-6 parts of chain extender; 5 to 9 parts of hydroxy acrylate monomer; 2-5 parts of acrylate monomer; 0.5-1 part of single-end vinyl polysiloxane; 80-90 parts of water.

[0007] By adopting the above technical solution, the polyurethane coating can effectively connect the substrate and the aluminum-plated layer, and under the plasma surface treatment, the bonding force between the polyurethane coating and the aluminum-plated layer is further improved, thereby improving the bonding force between the substrate and the aluminum-plated layer and improving the adhesion of the aluminum layer. Since the substrate is treated with wire drawing, the wire drawing surface of the substrate is uneven, and the ordinary polyurethane coating cannot fully contact the wire drawing surface of the substrate, which affects the improvement of the adhesion to the aluminum layer. Moreover, after long-term use, the bonding between the polyurethane coating and the substrate will also be reduced, and the durability of the wire drawing aluminum-plated film is insufficiently improved.

[0008] To this end, a polyurethane prepolymer modified with double-terminal hydroxypropyl polysiloxane is first synthesized in the polyurethane coating, and then grafted and formed with polyacrylate containing silicone, which not only forms a water-based polyurethane with strong adhesion, but also the silicone tends to migrate to the surface of the coating during the film-forming process. In addition, the good flexibility of the water-based polyurethane drives the surface of the coating to have a tendency to expand, and the coating can better diffuse into the lines of the brushed surface, so that the coating and the brushed surface are fully in contact and form a strong bond, which indirectly improves the adhesion of the aluminum layer to the substrate. In addition, during long-term use, it is not easy for outside air or moisture to enter between the coating and the substrate, thereby improving the durability of the brushed aluminum film.

[0009] Optionally, the molecular weight of the dual-terminal hydroxypropyl polysiloxane is 700-1000, and the molecular weight of the single-terminal vinyl polysiloxane is 12000-14000.

[0010] By adopting the above technical scheme, polyurethane and polyacrylate form a core-shell cross-linked structure, and the double-ended hydroxypropyl polysiloxane and the single-ended vinyl polysiloxane are respectively combined with the polyurethane and the polyacrylate. By adjusting the molecular weights of the double-ended hydroxypropyl polysiloxane and the single-ended vinyl polysiloxane, the compatibility of polyurethane and polyacrylate is ensured, and the overall flexibility and filling properties of the aqueous polyurethane dispersion are improved, and the long-term stable bonding between the polyurethane coating and the substrate is improved. The various mechanical properties of the brushed aluminum-plated film are at a good level, and ultimately the durability of the brushed aluminum-plated film is improved.

[0011] Optionally, the polyether polyol includes one or both of polyethylene glycol and polypropylene glycol.

[0012] By adopting the above technical scheme, the ether bonds of polyethylene glycol and polypropylene glycol are easy to rotate, and the elongation and flexibility of the aqueous polyurethane dispersion can be improved by combining with double-terminal hydroxypropyl polysiloxane.

[0013] Optionally, the diluent includes isopropyl alcohol and ethylene glycol ethyl ether mixed in a weight ratio of 1:(0.4-0.6).

[0014] By adopting the above technical solution, a mixture of two solvents with a boiling point difference of more than 40°C is used as a diluent, so that the curing speed of the coating can be adjusted, the coating can be fully diffused into the lines of the brushed surface, and the durability of the brushed aluminum film can be improved.

[0015] Optionally, the diisocyanate is isophorone diisocyanate.

[0016] By adopting the above technical solution, isophorone diisocyanate has good light aging resistance, which helps to improve the durability of the brushed aluminum film.

[0017] Optionally, the hydroxyacrylate monomer includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate; the acrylate monomer includes one or more of methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate and propyl methacrylate.

[0018] By adopting the above technical solution, the above hydroxy acrylate monomer can react and combine with the NCO group of the polyurethane prepolymer, so that the polyacrylate and the polyurethane form a core-shell cross-linked structure, thereby improving the structural stability of the waterborne polyurethane.

[0019] Optionally, the brushed substrate includes a brushed surface and a non-brushed surface, the polyurethane coating is provided on the brushed surface, and the non-brushed surface is provided with a printed coating.

[0020] By adopting the above technical solution, the printed coating can be a pattern or color for decoration or identification, thereby enriching the appearance of the brushed aluminum film.

[0021] Optionally, the brushed substrate is a PET brushed film.

[0022] Optionally, the chain extender includes 1,4-butanediol and 2,2-dimethylolpropionic acid.

[0023] Optionally, the raw materials of the aqueous polyurethane dispersion also include: Neutralizer 0.5-1 part; Initiator 0.1-0.7 parts; Catalyst 0.01-0.03 parts; Viscosity modifier 5-15 parts.

[0024] Optionally, the neutralizing agent is triethylamine.

[0025] Optionally, the initiator is dibenzoyl peroxide.

[0026] Optionally, the catalyst is dibutyltin dilaurate.

[0027] Optionally, the viscosity modifier is acetone.

[0028] In the second aspect, the present application provides a method for preparing a brushed aluminum-plated film using the following technical solution: A method for preparing a brushed aluminum-plated film comprises the following steps: Mixing and stirring the aqueous polyurethane dispersion, the diluent and water to obtain a polyurethane coating; Applying polyurethane coating on the wire drawing surface of the substrate, drying and curing, and forming a polyurethane coating; The surface of the polyurethane coating is subjected to plasma surface treatment, and then aluminum is vacuum evaporated on the surface of the polyurethane coating to form an aluminum-plated layer, which is then dried and solidified to obtain a brushed aluminum-plated film.

[0029] By adopting the above technical solution, the polyurethane coating undergoes plasma surface treatment to improve the surface activity of the polyurethane coating, thereby improving the adhesion between the aluminum layer and the polyurethane coating.

[0030] Optionally, the method for preparing the aqueous polyurethane dispersion comprises the following steps: The double-terminal hydroxypropyl polysiloxane is mixed with the polyether polyol, and an inert gas is introduced for protection. The mixture is heated to 80-90°C, and a diisocyanate is added to react for 1-1.5 hours. The mixture is then cooled to 70-80°C, and a chain extender is added to react for 1.5-2.5 hours. The hydroxy acrylate monomer is then added to react for 1-1.5 hours. The acrylate monomer and the single-terminal vinyl polysiloxane are then added to initiate the polymerization reaction for 0.5-1 hour. The mixture is then cooled to 40-50°C, and water is added. The mixture is stirred and emulsified to obtain an aqueous polyurethane dispersion.

[0031] By adopting the above technical scheme, a polyurethane prepolymer modified with double-terminal hydroxypropyl polysiloxane is first synthesized, and then a hydroxy acrylate monomer is grafted to introduce polyacrylate into the polyurethane structure to form a core-shell cross-linked structure. At the same time, the structure of the water-based polyurethane is adjusted by single-terminal vinyl polysiloxane to improve the diffusibility of the water-based polyurethane and fully improve the bonding force between the drawing substrate and the polyurethane coating.

[0032] Optionally, the method for preparing the aqueous polyurethane dispersion comprises the following steps: The double-terminal hydroxypropyl polysiloxane is mixed with the polyether polyol, and an inert gas is introduced for protection. The mixture is heated to 80-90°C, and a diisocyanate is added to react for 1-1.5 hours. The mixture is then cooled to 70-80°C, and a chain extender is added to react for 2-2.5 hours. A viscosity modifier is then added, and a catalyst and a hydroxy acrylate monomer are added to react for 1-1.5 hours. An initiator, an acrylate monomer and a single-terminal vinyl polysiloxane are added to react for 0.5-1 hour. The mixture is then cooled to 40-50°C, and a neutralizer is added to react for 0.2-0.5 hours. Water is added, and the mixture is stirred and emulsified to obtain an aqueous polyurethane dispersion.

[0033] Optionally, the working gas in the plasma treatment method is air, the working gas flow rate is 1000-1500 sccm, and the plasma treatment power is 2-3 kW.

[0034] In summary, this application has the following beneficial effects: 1. The polyurethane coating can effectively connect the substrate and the aluminum-plated layer, and under the plasma surface treatment, the bonding force between the polyurethane coating and the aluminum-plated layer is further improved. In the polyurethane coating, a double-terminal hydroxypropyl polysiloxane-modified polyurethane prepolymer is first synthesized, and then grafted and formed into a polyacrylate containing silicone, which not only forms a water-based polyurethane with strong adhesion, but also the silicone tends to migrate to the coating surface during the film-forming process. In addition, the water-based polyurethane has good flexibility, which drives the coating surface to have a tendency to expand. The coating can better diffuse into the lines of the brushed surface, so that the coating is fully in contact with the brushed surface and forms a firm bond, thereby improving the durability of the brushed aluminum-plated film.

[0035] 2. Polyurethane and polyacrylate form a core-shell cross-linked structure. Double-ended hydroxypropyl polysiloxane and single-ended vinyl polysiloxane are respectively combined with polyurethane and polyacrylate. By adjusting the molecular weight of double-ended hydroxypropyl polysiloxane and single-ended vinyl polysiloxane, the compatibility of polyurethane and polyacrylate is ensured, and the overall flexibility and filling properties of the aqueous polyurethane dispersion are improved, thereby improving the long-term stable bonding between the polyurethane coating and the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a layer structure diagram of the brushed aluminum-plated film of Examples 1-3 of the present application.

[0037] Description of reference numerals: 1. Brushed substrate; 2. Polyurethane coating; 3. Aluminum coating. DETAILED DESCRIPTION

[0038] The following is combined with Figure 1 This application is described in further detail.

[0039] Preparation Example 1 The preparation method of the aqueous polyurethane dispersion comprises the following steps: Weigh 0.2 kg of double-terminal hydroxypropyl polysiloxane, 2 kg of polyether polyol, 1.5 kg of diisocyanate, 0.3 kg of chain extender, 0.5 kg of hydroxy acrylate monomer, 0.2 kg of acrylate monomer, 0.05 kg of single-terminal vinyl polysiloxane, 8 kg of water, 0.05 kg of neutralizer, 0.01 kg of initiator, 1 g of catalyst, and 0.5 kg of viscosity modifier.

[0040] Among them, the number average molecular weight of the double-terminated hydroxypropyl polysiloxane is 700; the polyether polyol is specifically polyethylene glycol with a number average molecular weight of 2000; the diisocyanate is specifically isophorone diisocyanate; the chain extender includes 0.1 kg of 1,4-butanediol and 0.2 kg of 2,2-dihydroxymethylpropionic acid, and the 2,2-dihydroxymethylpropionic acid is pre-dissolved in 0.2 kg of N-methylpyrrolidone to form a 2,2-dihydroxymethylpropionic acid solution; the hydroxyacrylate monomer is specifically hydroxyethyl methacrylate; the acrylate monomer is specifically methyl methacrylate; the number average molecular weight of the single-terminated vinyl polysiloxane is 12000; the neutralizer is specifically triethylamine; the initiator is specifically dibenzoyl peroxide; the catalyst is specifically dibutyltin dilaurate; and the viscosity modifier is specifically acetone.

[0041] The double-terminal hydroxypropyl polysiloxane and the polyether polyol are mixed, nitrogen is introduced for protection, the mixture is heated to 80°C, diisocyanate is added and reacted for 1.5 hours, then the temperature is lowered to 70°C, 1,4-butanediol is added and reacted for 1 hour, 2,2-dihydroxymethylpropionic acid solution is added and reacted for 1.5 hours, then a viscosity modifier is added, the mixture is stirred evenly, a catalyst and a hydroxy acrylate monomer are added and reacted for 1.5 hours, then an initiator, an acrylate monomer and a single-terminal vinyl polysiloxane are added and reacted for 1 hour, the mixture is cooled to 40°C, a neutralizer is added and reacted for 0.5 hours, water is added, the mixture is stirred and emulsified, and the viscosity modifier is removed by rotary evaporation to obtain an aqueous polyurethane dispersion.

[0042] Preparation Example 2 The preparation method of the aqueous polyurethane dispersion comprises the following steps: Weigh 0.8 kg of double-terminal hydroxypropyl polysiloxane, 1.5 kg of polyether polyol, 2 kg of diisocyanate, 0.6 kg of chain extender, 0.9 kg of hydroxy acrylate monomer, 0.5 kg of acrylate monomer, 0.1 kg of single-terminal vinyl polysiloxane, 9 kg of water, 0.1 kg of neutralizer, 0.07 kg of initiator, 3 g of catalyst, and 1.5 kg of viscosity modifier.

[0043] Among them, the number average molecular weight of the double-terminated hydroxypropyl polysiloxane is 1000; the polyether polyol is specifically polyethylene glycol with a number average molecular weight of 2000; the diisocyanate is specifically isophorone diisocyanate; the chain extender includes 0.3 kg of 1,4-butanediol and 0.3 kg of 2,2-dihydroxymethylpropionic acid, and the 2,2-dihydroxymethylpropionic acid is pre-dissolved in 0.3 kg of N-methylpyrrolidone to form a 2,2-dihydroxymethylpropionic acid solution; the hydroxyacrylate monomer is specifically hydroxyethyl methacrylate; the acrylate monomer is specifically methyl methacrylate; the number average molecular weight of the single-terminated vinyl polysiloxane is 14000; the neutralizer is specifically triethylamine; the initiator is specifically dibenzoyl peroxide; the catalyst is specifically dibutyltin dilaurate; and the viscosity modifier is specifically acetone.

[0044] The double-terminal hydroxypropyl polysiloxane and the polyether polyol are mixed, nitrogen is introduced for protection, and the mixture is heated to 90°C, and diisocyanate is added to react for 1 hour, and then the temperature is lowered to 80°C, 1,4-butanediol is added to react for 0.5 hour, and then 2,2-dihydroxymethylpropionic acid solution is added to react for 1 hour, and then a viscosity regulator is added. After stirring evenly, a catalyst and a hydroxy acrylate monomer are added to react for 1 hour, and then an initiator, an acrylate monomer and a single-terminal vinyl polysiloxane are added to react for 0.5 hour, and the temperature is lowered to 50°C, and a neutralizer is added to react for 0.2 hour, and water is added. The mixture is stirred and emulsified, and the viscosity regulator is removed by rotary evaporation to obtain an aqueous polyurethane dispersion.

[0045] Preparation Example 3 The preparation method of the aqueous polyurethane dispersion comprises the following steps: Weigh 0.4 kg of double-terminal hydroxypropyl polysiloxane, 1.7 kg of polyether polyol, 1.7 kg of diisocyanate, 0.4 kg of chain extender, 0.6 kg of hydroxy acrylate monomer, 0.3 kg of acrylate monomer, 0.08 kg of single-terminal vinyl polysiloxane, 8.5 kg of water, 0.07 kg of neutralizer, 0.03 kg of initiator, 1.5 g of catalyst, and 1 kg of viscosity modifier.

[0046] Among them, the number average molecular weight of the double-terminal hydroxypropyl polysiloxane is 700; the polyether polyol is specifically polyethylene glycol with a number average molecular weight of 2000; the diisocyanate is specifically isophorone diisocyanate; the chain extender includes 0.15 kg of 1,4-butanediol and 0.25 kg of 2,2-dihydroxymethylpropionic acid, and the 2,2-dihydroxymethylpropionic acid is pre-dissolved in 0.25 kg of N-methylpyrrolidone to form a 2,2-dihydroxymethylpropionic acid solution; the hydroxyacrylate monomer is specifically hydroxyethyl methacrylate; the acrylate monomer is specifically methyl methacrylate; the number average molecular weight of the single-terminal vinyl polysiloxane is 12000; the neutralizer is specifically triethylamine; the initiator is specifically dibenzoyl peroxide; the catalyst is specifically dibutyltin dilaurate; and the viscosity modifier is specifically acetone.

[0047] The double-terminal hydroxypropyl polysiloxane and the polyether polyol are mixed, nitrogen is introduced for protection, heated to 80°C, diisocyanate is added to react for 1.5 hours, then the temperature is lowered to 70°C, 1,4-butanediol is added to react for 1 hour, and then 2,2-dihydroxymethylpropionic acid solution is added to react for 1.5 hours, and then a viscosity regulator is added. After stirring evenly, a catalyst and a hydroxy acrylate monomer are added to react for 1.5 hours, and then an initiator, an acrylate monomer and a single-terminal vinyl polysiloxane are added to react for 1 hour, the temperature is lowered to 40°C, a neutralizer is added to react for 0.5 hours, water is added, stirred and emulsified, and the viscosity regulator is removed by rotary evaporation to obtain an aqueous polyurethane dispersion.

[0048] Preparation Example 4 The difference between this preparation example and preparation example 3 is that the number average molecular weight of the dual-terminal hydroxypropyl polysiloxane is 1200, and the number average molecular weight of the single-terminal vinyl polysiloxane is 10000.

[0049] Comparative Preparation Example 1 The difference between this comparative preparation example and preparation example 3 is that an equal amount of polyether polyol is used to replace the double-terminal hydroxypropyl polysiloxane, that is, no double-terminal hydroxypropyl polysiloxane is added, and the amount of polyether polyol used is 2.1 kg.

[0050] Comparative Preparation Example 2 The difference between this comparative preparation example and preparation example 3 is that an equal amount of acrylate monomer is used to replace the single-end vinyl polysiloxane, that is, the single-end vinyl polysiloxane is not added, and the amount of acrylate monomer used is 0.38 kg.

[0051] Comparative Preparation Example 3 The preparation method of the aqueous polyurethane dispersion comprises the following steps: Weigh 0.4 kg of double-terminal hydroxypropyl polysiloxane, 1.7 kg of polyether polyol, 1.7 kg of diisocyanate, 0.4 kg of chain extender, 8.5 kg of water, 0.07 kg of neutralizer, and 1 kg of viscosity modifier.

[0052] Among them, the number average molecular weight of the double-terminated hydroxypropyl polysiloxane is 700; the polyether polyol is specifically polyethylene glycol with a number average molecular weight of 2000; the diisocyanate is specifically isophorone diisocyanate; the chain extender includes 0.15 kg of 1,4-butanediol and 0.25 kg of 2,2-dihydroxymethylpropionic acid, and the 2,2-dihydroxymethylpropionic acid is pre-dissolved in 0.25 kg of N-methylpyrrolidone to form a 2,2-dihydroxymethylpropionic acid solution; the neutralizer is specifically triethylamine; and the viscosity regulator is specifically acetone.

[0053] The double-terminal hydroxypropyl polysiloxane and the polyether polyol are mixed, nitrogen is introduced for protection, the mixture is heated to 80°C, diisocyanate is added and reacted for 1.5 hours, then the temperature is lowered to 70°C, 1,4-butanediol is added and reacted for 1 hour, 2,2-dihydroxymethylpropionic acid solution is added and reacted for 1.5 hours, then a viscosity regulator is added, the temperature is lowered to 40°C, a neutralizer is added and reacted for 0.5 hours, water is added, the mixture is stirred and emulsified, and the viscosity regulator is removed by rotary evaporation to obtain an aqueous polyurethane dispersion.

[0054] Example 1 A brushed aluminum film, such as Figure 1 As shown, it includes a wire drawing substrate 1, a polyurethane coating 2 and an aluminum plating layer 3 which are arranged in sequence.

[0055] The wire drawing substrate is a PET wire drawing film with a thickness of 45 μm.

[0056] The preparation method of the brushed aluminum-plated film comprises the following steps: Weigh 10 kg of aqueous polyurethane dispersion, 6 kg of diluent, and 6 kg of water.

[0057] The aqueous polyurethane dispersion is prepared according to Preparation Example 1; the diluent is specifically isopropanol.

[0058] The aqueous polyurethane dispersion, the diluent and water are mixed and stirred to obtain the polyurethane coating.

[0059] Polyurethane coating is applied on one side of the PET drawing film, with a coating amount of 0.82g / m 2 Then the PET drawing film is conveyed into the drying tunnel for drying and curing. The drying tunnel is divided into seven sections, and the temperature of each section is 90℃, 110℃, 120℃, 120℃, 130℃, 120℃, and 105℃ respectively. The drying tunnel is 10m long and the conveying speed is 60m / min, forming a polyurethane coating with a thickness of 0.08μm.

[0060] The surface of the polyurethane coating is subjected to glow discharge plasma treatment, the working gas in the plasma treatment method is air, the working gas flow rate is 1000 sccm, and the plasma treatment power is 2 kW.

[0061] Finally, it was sent to the vacuum evaporation equipment to vacuum evaporate aluminum on the surface of the polyurethane coating. During the vacuum evaporation process, the aluminum plating speed was 3.9m / s, the temperature of the heated aluminum wire was 1400℃, and the wire feeding speed of the aluminum wire was 700mm / min, forming an aluminum plating layer with a thickness of 450 angstroms. It was then dried and cured in a 60℃ oven for 72 hours to obtain a brushed aluminum-plated film.

[0062] Example 2 The difference between this embodiment and embodiment 1 is that the preparation method of the brushed aluminum-plated film is different.

[0063] Weigh 10 kg of aqueous polyurethane dispersion, 10 kg of diluent, and 10 kg of water.

[0064] The aqueous polyurethane dispersion is prepared according to Preparation Example 2, and the diluent is isopropanol.

[0065] The aqueous polyurethane dispersion, the diluent and water are mixed and stirred to obtain the polyurethane coating.

[0066] Polyurethane coating is applied on one side of the PET drawing film, with a coating amount of 0.94g / m 2 Then the PET drawing film is conveyed into the drying tunnel for drying and curing. The drying tunnel is divided into seven sections, and the temperature of each section is 90℃, 110℃, 120℃, 120℃, 130℃, 120℃, and 105℃ respectively. The drying tunnel is 10m long and the conveying speed is 60m / min, forming a polyurethane coating with a thickness of 0.08μm.

[0067] The surface of the polyurethane coating is subjected to a plasma treatment in a glow discharge manner. The working gas in the plasma treatment method is air, the working gas flow rate is 1500 sccm, and the plasma treatment power is 3 kW.

[0068] Finally, it was sent to the vacuum evaporation equipment to vacuum evaporate aluminum on the surface of the polyurethane coating. During the vacuum evaporation process, the aluminum plating speed was 3.9m / s, the temperature of the heated aluminum wire was 1400℃, and the wire feeding speed of the aluminum wire was 700mm / min, forming an aluminum plating layer with a thickness of 450 angstroms. It was then dried and cured in a 60℃ oven for 72 hours to obtain a brushed aluminum-plated film.

[0069] Example 3 The difference between this embodiment and embodiment 1 is that the composition of the polyurethane coating is different.

[0070] The composition of the polyurethane coating is: 10 kg of water-based polyurethane dispersion, 8 kg of diluent, and 8 kg of water.

[0071] The aqueous polyurethane dispersion was prepared according to Preparation Example 3, and the diluent was isopropanol.

[0072] The coating amount of polyurethane coating is 0.89g / m 2 .

[0073] Example 4 The difference between this embodiment and embodiment 3 is that the composition of the aqueous polyurethane dispersion is different.

[0074] The aqueous polyurethane dispersion was prepared by Preparation Example 4.

[0075] Example 5 The difference between this embodiment and embodiment 3 is that the composition of the diluent is different.

[0076] The diluent is prepared by mixing isopropyl alcohol and ethylene glycol ethyl ether in a weight ratio of 1:0.4.

[0077] Example 6 The difference between this embodiment and embodiment 3 is that the composition of the diluent is different.

[0078] The diluent is prepared by mixing isopropyl alcohol and ethylene glycol ethyl ether in a weight ratio of 1:0.6.

[0079] Example 7 The difference between this embodiment and embodiment 3 is that the non-drawn surface of the brushed aluminum-plated film is also provided with a printed coating.

[0080] After the step of preparing the brushed aluminized film, a UV printing coating is applied to the non-brushed surface of the brushed aluminized film, and UV curing is performed to finally form patterns and colors on the brushed aluminized film.

[0081] Comparative Example 1 The difference between this comparative example and Example 3 is that the composition of the aqueous polyurethane dispersion is different.

[0082] The aqueous polyurethane dispersion was prepared by Comparative Preparation Example 1.

[0083] Comparative Example 2 The difference between this comparative example and Example 3 is that the composition of the aqueous polyurethane dispersion is different.

[0084] The aqueous polyurethane dispersion was prepared by Comparative Preparation Example 2.

[0085] Comparative Example 3 The difference between this comparative example and Example 3 is that the composition of the aqueous polyurethane dispersion is different.

[0086] The aqueous polyurethane dispersion was prepared by Comparative Preparation Example 3.

[0087] Comparative Example 4 The preparation method of the brushed aluminum-plated film comprises the following steps: The drawing surface of the PET drawing film is subjected to a plasma treatment in a glow discharge manner. The working gas in the plasma treatment method is air, the working gas flow rate is 1000 sccm, and the power of the plasma treatment is 2 kW.

[0088] Finally, it was sent to the vacuum evaporation equipment to vacuum-evaporate aluminum on the drawing surface. During the vacuum evaporation process, the aluminum plating speed was 3.9m / s, the temperature of the heated aluminum wire was 1400℃, and the wire feeding speed of the aluminum wire was 700mm / min, forming an aluminum plating layer with a thickness of 450 angstroms. It was then dried and cured in an oven at 60℃ for 72 hours to obtain a drawing aluminum-plated film.

[0089] Performance Testing The following tests were performed on the brushed aluminum-plated films prepared in Examples 1-6 and Comparative Examples 1-4.

[0090] Adhesion of aluminized layer: refer to QB / T 2358-1998 "Test method for heat sealing strength of plastic film packaging bags", heat seal the heat sealing layer of EAA film and the aluminized layer of brushed aluminized film, the heat sealing temperature is 125℃, the pressure is 0.25MPa, and the heat sealing time is 1.8s. Then use a tensile testing machine to peel off the aluminized layer from the brushed aluminized film to obtain adhesion data. The results are shown in Table 1.

[0091] Adhesion durability: The brushed aluminum-plated film was placed in a test box at 120°C and 85% humidity for aging for 240 hours, and then the aluminum-plated layer adhesion test was performed. The results are shown in Table 1.

[0092] Table 1 Adhesion(N / 15mm) Adhesion after aging (N / 15mm) Example 1 3.5 2.8 Example 2 3.2 2.6 Example 3 3.7 3.0 Example 4 3.3 2.3 Example 5 3.6 3.2 Example 6 3.8 3.4 Comparative Example 1 2.9 1.5 Comparative Example 2 2.8 1.5 Comparative Example 3 2.5 1.1 Comparative Example 4 1.3 0.5 It can be seen from Table 1 that the brushed aluminum-plated films prepared in Examples 1-3 all have relatively high adhesion of the aluminum-plated layer, and can still maintain the adhesion of the aluminum-plated layer at a relatively high level after aging under high temperature and high humidity, and thus have good durability.

[0093] Compared with comparative examples 3-4, the mechanical properties of Example 3 are better than those of comparative examples 3-4. Further combined with Table 1, it can be seen that Example 3 has a more obvious advantage in adhesion. It is proved that compared with directly evaporating the aluminum coating on the brushed surface, first forming a polyurethane coating on the brushed surface can help improve the bonding force between the brushed substrate and the aluminum coating, and the cross-linked structure of polyurethane and polyacrylate is helpful to improve the durability of the brushed aluminum coating.

[0094] Compared with Comparative Examples 1-2, it can be seen that Example 3 has an obvious advantage in the durability of the adhesion of the aluminum coating, proving that the aqueous polyurethane dispersion modified with silicone in multiple steps can fully diffuse to the surface of the brushed substrate, reducing the interference of external air or water vapor between the coating and the substrate, thereby improving the continuous adhesion of the aluminum coating.

[0095] Compared with Example 4, Example 3 also has an obvious advantage in the durability of the aluminum coating adhesion, proving that the synergistic combination of the two double-terminal hydroxypropyl polysiloxanes and the single-terminal vinyl polysiloxane helps to improve the continuous bonding between the coating and the substrate.

[0096] The adhesion durability of the aluminum-plated layer of Examples 5-6 is higher than that of Example 3, which proves that by adjusting the composition of the diluent and regulating the curing speed of the coating, the diffusivity of the aqueous polyurethane dispersion can be fully utilized, thereby improving the durability of the brushed aluminum-plated film.

[0097] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A brushed aluminum film, characterized in that: The invention comprises a wire drawing substrate, a polyurethane coating and an aluminum plating layer which are arranged in sequence, wherein the polyurethane coating is formed by curing a polyurethane coating, the polyurethane coating is subjected to plasma surface treatment, and the polyurethane coating comprises an aqueous polyurethane dispersion, a diluent and water in a weight ratio of 1:(0.6-1):(0.6-1); The aqueous polyurethane dispersion is prepared from the following raw materials in parts by weight: 2-8 parts of double-terminal hydroxypropyl polysiloxane; 15-20 parts of polyether polyol; 15-20 parts of diisocyanate; 3~6 parts of chain extender; 5-9 parts of hydroxy acrylate monomer; 2-5 parts of acrylate monomer; 0.5~1 part of single-end vinyl polysiloxane; 80~90 parts of water.

2. The brushed aluminum-plated film according to claim 1, characterized in that: The molecular weight of the double-terminal hydroxypropyl polysiloxane is 700-1000, and the molecular weight of the single-terminal vinyl polysiloxane is 12000-15000.

3. The brushed aluminum-plated film according to claim 1, characterized in that: The polyether polyol includes one or both of polyethylene glycol and polypropylene glycol.

4. The brushed aluminum-plated film according to claim 1, characterized in that: The diluent includes isopropyl alcohol and ethylene glycol ethyl ether mixed in a weight ratio of 1:(0.4-0.6).

5. The brushed aluminum-plated film according to claim 1, characterized in that: The diisocyanate is isophorone diisocyanate.

6. The brushed aluminum-plated film according to claim 1, characterized in that: The hydroxy acrylate monomer includes one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate; the acrylate monomer includes one or more of methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate and propyl methacrylate.

7. A brushed aluminum-plated film according to any one of claims 1 to 6, characterized in that: The wire drawing substrate comprises a wire drawing surface and a non-wire drawing surface, the polyurethane coating is arranged on the wire drawing surface, and the non-wire drawing surface is provided with a printed coating.

8. A method for preparing a brushed aluminum-plated film according to any one of claims 1 to 7, characterized in that: The following steps are involved: Mixing and stirring the aqueous polyurethane dispersion, the diluent and water to obtain a polyurethane coating; Applying polyurethane coating on the wire drawing surface of the substrate, drying and curing, and forming a polyurethane coating; The surface of the polyurethane coating is subjected to plasma surface treatment, and then aluminum is vacuum evaporated on the surface of the polyurethane coating to form an aluminum-plated layer, which is then dried and solidified to obtain a brushed aluminum-plated film.

9. The method for preparing a brushed aluminum-plated film according to claim 8, characterized in that: The preparation method of the aqueous polyurethane dispersion comprises the following steps: Mix the double-terminal hydroxypropyl polysiloxane and the polyether polyol, pass an inert gas for protection, heat to 80-90°C, add diisocyanate to react for 1-1.5h, then cool to 70-80°C, add a chain extender to react for 1.5-2.5h, then add a hydroxy acrylate monomer to react for 1-1.5h, then add an acrylate monomer and a single-terminal vinyl polysiloxane to initiate a polymerization reaction for 0.5-1h, cool to 40-50°C, add water, stir and emulsify to obtain an aqueous polyurethane dispersion.

10. The method for preparing a brushed aluminum-plated film according to claim 8, characterized in that: The working gas in the plasma treatment method is air, the working gas flow rate is 1000~1500sccm, and the power of the plasma treatment is 2~3kW.

Images