Wear-resistant PVC decorative film and preparation method thereof

Abstract

The invention provides a wear-resistant PVC decorative film and a preparation method thereof, and relates to the field of composite films. Comprising a PVC base material layer, a bonding layer and a film covering layer which are sequentially arranged. The PVC base material layer is prepared from the following raw materials in parts by weight: 90 to 100 parts of PVC resin, 10 to 20 parts of chlorinated polyethylene resin, 1 to 5 parts of plasticizer, 1 to 5 parts of lubricant, 5 to 10 parts of montmorillonite / nano silicon dioxide compound and 1 to 5 parts of calcium-zinc compound stabilizer; the film coating layer is prepared from the following raw materials in parts by weight: 90 to 100 parts of PET (Polyethylene Terephthalate) resin; the adhesive is prepared from the following components in parts by weight: 10 to 20 parts of polyisocyanate, 5 to 10 parts of acrylate copolymer, 1 to 5 parts of modified flake alumina, 1 to 5 parts of modified glass flake and 0.1 to 0.2 part of dibutyltin dilaurate. And the bonding layer is a silicone adhesive. And the wear-resisting performance is good, the bonding strength between layers is high, and the service life is long.

Description

Technical Field

[0001] The present invention relates to the field of composite films, and in particular to a wear-resistant PVC decorative film and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) decorative film is a new decorative material made from PVC resin, using additives and calendering, laminating, or printing processes. It offers advantages such as lightness, durability, design flexibility, and environmental friendliness, making it widely used in architecture, furniture, transportation, and consumer electronics.

[0003] Through physical or chemical modification, the wear resistance of the surface of PVC decorative film can be improved. It can be applied to furniture, flooring, automotive interior, electronic products and other fields. For example, furniture veneer, interior decoration, commercial flooring, elevator interior and other high wear scenes can extend the service life of PVC decorative film. Currently, there are several ways to improve the wear resistance of PVC decorative film.

[0004] Surface coating technology: UV-curable coatings, nano-aluminum oxide, or silicone coatings are used to enhance the surface hardness of PVC decorative films. However, this increases production costs, and coating thickness and uniformity must be strictly controlled to ensure consistent wear resistance, placing stringent requirements on coating application.

[0005] Blending modification: Wear-resistant fillers (such as silica and silicon carbide particles) are added to the PVC base material to enhance scratch resistance. However, the dispersion and compatibility of the fillers must be strictly controlled to ensure improved wear resistance. In addition, the addition of fillers can affect the processing properties of the PVC decorative film, such as melt flowability and formability.

[0006] Composite structures: Composited with materials such as PET and TPU to form a multilayer structure to balance wear resistance and flexibility. The composite process increases production costs, and the interlayer bonding strength must be strictly controlled to ensure the stability of the composite structure and the consistency of wear resistance. For example, Patent 202410084124.6 discloses a PVC-PET composite sheet film and its preparation method. Polysiloxane / polyester diol complex, polyisocyanate, and modified nanosilica are added to polyethylene terephthalate (PET) to improve the wear resistance of PET, but the bonding strength between the layers needs to be improved. Summary of the Invention

[0007] The object of the present invention is to provide a wear-resistant PVC decorative film, which has good wear resistance, high bonding strength between layers and long service life.

[0008] Another object of the present invention is to provide a method for preparing a wear-resistant PVC decorative film, wherein the PVC film and the coating are first surface treated and then composited by hot pressing to form a chemical bond between the PVC film and the coating, thereby improving the bonding strength between the two layers.

[0009] The present invention solves the technical problem by adopting the following technical solutions.

[0010] On the one hand, an embodiment of the present invention provides a wear-resistant PVC decorative film, comprising a PVC substrate layer, an adhesive layer and a coating layer arranged in sequence;

[0011] The PVC substrate layer comprises the following raw materials by weight: 90-100 parts of PVC resin, 10-20 parts of chlorinated polyethylene resin, 1-5 parts of plasticizer, 1-5 parts of lubricant, 5-10 parts of montmorillonite / nanosilica composite, and 1-5 parts of calcium zinc composite stabilizer;

[0012] The coating layer comprises the following raw materials in parts by weight: 90-100 parts of PET resin; 10-20 parts of polyisocyanate, 5-10 parts of acrylate copolymer, 1-5 parts of modified flaky aluminum oxide, 1-5 parts of modified glass flakes, and 0.1-0.2 parts of dibutyltin dilaurate;

[0013] The bonding layer is a silicone adhesive.

[0014] In some embodiments of the present invention, the montmorillonite / nanosilica composite is prepared by the following method:

[0015] Nano-silica is calcined at 1200° C. for 1-2 hours in a mixed atmosphere of H2 and inert gas, and rapidly cooled to room temperature at a rate of 30-50° C. / min to obtain hydrophobic nano-silica; montmorillonite, hexadecyltrimethylammonium bromide, and an ethanol solution are mixed, ultrasonically dispersed at 60-70° C. for 1-2 hours, and then a silane coupling agent and the hydrophobic nano-silica are added. The mixture is ultrasonically dispersed for 10-20 minutes, centrifuged, vacuum dried at 50-60° C., and ground to obtain the montmorillonite / nano-silica composite.

[0016] Under a reducing atmosphere, elemental silicon can be formed on the surface of nano-silica through high-temperature calcination. Subsequently, under the action of rapid cooling, a crack network is formed on the surface of nano-silica. The microcracks increase the surface roughness, reduce the hydroxyl (Si-OH) density, and improve the hydrophobicity.

[0017] Under the action of ultrasound, hexadecyltrimethylammonium bromide is used to exchange ions with the montmorillonite layers, so that hexadecyltrimethylammonium bromide is embedded in the montmorillonite layers and the interlayer spacing of the montmorillonite is increased. Subsequently, under the action of the coupling agent, the hydrophobic nano-silica enters the montmorillonite layers. The strong binding force between the two can also reduce the agglomeration of nano-silica and improve its dispersion uniformity in PVC.

[0018] During the preparation of PVC film, the layered montmorillonite is oriented through melt extrusion molding, and the nano-silica embedded between the layers can serve as reinforcing particles to improve the tensile strength of the PVC film. The hexadecyltrimethylammonium bromide embedded between the layers has a longer molecular chain and can be embedded in the PVC molecular chain, thereby enhancing the bonding force between montmorillonite and PVC.

[0019] In some embodiments of the present invention, the mass ratio of montmorillonite, hydrophobic nano-silica, hexadecyltrimethylammonium bromide, and ethanol is 1:(0.8-1):(0.3-0.5):(0.3-0.5).

[0020] In some embodiments of the present invention, the modified flaky aluminum oxide is prepared as follows:

[0021] Nano-flaky γ-Al2O3 is mixed with toluene, heated and stirred under an inert atmosphere. A toluene solution of oleamine is then added dropwise, and the mixture is refluxed at 100-120°C for 2-3 hours. The mixture is cooled, filtered, washed, vacuum-dried, and ground to obtain the modified flaky alumina. The amount of oleylamine added is 2-3% by weight of the γ-Al2O3. Oleylamine modifies the alumina surface, condensing with the surface hydroxyl groups to form Al-O-N bonds. The long C18 chain provides steric hindrance, inhibiting aggregation and promoting uniform dispersion of the flaky alumina within the coating.

[0022] In some embodiments of the present invention, the modified glass flakes are prepared by the following method:

[0023] Soak the glass flakes in a hydrofluoric acid solution for 1-2 minutes, wash them clean, and obtain pretreated glass flakes; mix the silane coupling agent, water, and acetic acid, stir them evenly, let them stand for 20-30 minutes, then add the pretreated glass flakes, octamercapto POSS, and dibenzoyl peroxide, react for 2-3 hours in an inert atmosphere at 80-100°C, quench the reaction, collect the solid by suction, and wash it to obtain the modified glass flakes. Through pretreatment, pits are formed on the surface of the glass flakes. Subsequently, under the action of silane coupling agent, water and acetic acid, covalent bonds are formed on the surface of the glass flakes, and the groups of the silane coupling agent (such as methoxy and ethoxy) are grafted to the surface of the glass flakes, providing active sites for subsequent reactions with the surface of the glass flakes. Subsequently, octamercapto POSS and dibenzoyl peroxide are added, and the thiol (-SH) forms a covalent bond with the metal oxide to enhance the interface bonding; during the melt extrusion molding process, the unreacted thiol is incorporated into the molecular chain of the PET resin to form a three-dimensional network structure, thereby enhancing the bonding strength between the modified glass flakes and the PET resin.

[0024] In some embodiments of the present invention, the mass ratio of pretreated glass flakes to octamercapto POSS is 1:(1-1.2). This ratio ensures that there are no unreacted thiol groups on the modified glass flakes. The volume ratio of silane coupling agent, water, and acetic acid is 1:(0.8-1):(0.8-1).

[0025] On the other hand, an embodiment of the present invention provides a method for preparing a wear-resistant PVC decorative film, which comprises: S1, mixing the raw materials of the PVC substrate layer, and melt-extruding to obtain a PVC film;

[0026] S2, mixing the raw materials of the coating layer, and melt-extruding to obtain a coating;

[0027] S3, in an atmosphere of oxygen and inert gas, plasma treating the surfaces of the PVC film and the covering film to be bonded, and then sequentially coating the surfaces of the PVC film and the covering film to be bonded with a silane coupling agent and a silicone adhesive;

[0028] S4, hot pressing and laminating at 110-120° C., and cooling to obtain the wear-resistant PVC decorative film.

[0029] By plasma treating the PVC film and the covering film, oxygen-containing functional groups are grafted onto the surface of the film. During the hot pressing composite process, the long carbon molecular chains of hexadecyltrimethylammonium bromide and silicone adhesive on the surface of the PVC film, and the octamercapto POSS and oleylamine on the surface of the covering film can form chemical bonds, or the molecular chains of the PET resin are embedded in the montmorillonite layers to form anchor points. The PVC resin molecules and the octamercapto POSS molecular chains are intertwined to improve the bonding strength between the PVC film and the covering film.

[0030] In some embodiments of the present invention, the power of the plasma treatment is 200-275 W·min / m², and the treatment time is 30-60 s.

[0031] In some embodiments of the present invention, in step S4, the pressure of the hot pressing composite is 0.5-1.0 MPa, and the time is 10-30 s.

[0032] In some embodiments of the present invention, in step S3, the amount of the coated silane coupling agent is 0.5-1 wt % of the silicone adhesive.

[0033] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0034] The wear-resistant PVC film provided by the present invention is composited with a PVC substrate layer and a coating layer, and has good wear resistance and strong interlayer bonding. A montmorillonite / nanosilica composite is added to the PVC base material, and the nanosilica can improve the mechanical properties of the PVC film. The layered structure of the montmorillonite enables it to form an intercalation or exfoliation structure in the PVC matrix, effectively transferring stress and enhancing mechanical properties. The composite of montmorillonite and nanosilica can, on the one hand, avoid the agglomeration of nanosilica and improve the dispersibility of nanosilica in the PVC substrate. On the other hand, the nanosilica is inserted into the interlayer of the montmorillonite, and the bonding strength between the two is high, which can improve the bonding strength between the nanosilica and the substrate, reduce the overflow of nanosilica during stress, and improve the tensile properties of the PVC film.

[0035] Flaky aluminum oxide and glass flakes are added to the coating layer. The flaky structure particles are stacked and arranged on the surface of the film, which can provide the film with barrier properties and wear resistance. The glass flakes and flaky aluminum oxide are used together to enhance the synergy and jointly improve the wear resistance of the PVC film.

[0036] The preparation method provided by the present invention first performs plasma treatment on the surface of the PVC film and the coating, grafts oxygen-containing functional groups such as -OH, -COOH, etc. on the surface of the PVC film and the coating, and then coats the surface with a silane coupling agent and a silicone adhesive. Under the action of the silane coupling agent and hot pressing, the adhesive and the PVC film and the coating can form a chemical bond, thereby improving the interlayer bonding strength of the PVC film and the coating. DETAILED DESCRIPTION

[0037] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0038] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to specific embodiments.

[0039] Example 1

[0040] 1. Prepare montmorillonite / nanosilica composites as follows:

[0041] In a mixed atmosphere of H2 and inert gas, nano-silica was calcined at 1200°C for 2 hours, and then rapidly cooled to room temperature at a rate of 50°C / min to obtain hydrophobic nano-silica;

[0042] Montmorillonite, hexadecyltrimethylammonium bromide, and an ethanol solution were mixed and ultrasonically dispersed at 70°C for 1 hour. A silane coupling agent and the hydrophobic nano-silica were then added and ultrasonically dispersed for 20 minutes. The mixture was centrifuged, vacuum-dried at 60°C, and ground to obtain a montmorillonite / nano-silica composite. The mass ratio of montmorillonite, hydrophobic nano-silica, hexadecyltrimethylammonium bromide, and ethanol was 1:0.8:0.3:0.5.

[0043] 2. Prepare modified flaky alumina as follows:

[0044] Nano-flaky γ-Al2O3 is mixed with toluene, heated and stirred uniformly under an inert atmosphere; a toluene solution of oleylamine is then added dropwise, and the mixture is refluxed at 100°C for 3 hours. The mixture is then cooled, filtered, washed, vacuum-dried, and ground to obtain the modified flaky aluminum oxide. The amount of oleylamine added is 3 wt% of the nano-flaky γ-Al2O3.

[0045] 3. Prepare modified glass flakes as follows:

[0046] Glass flakes were immersed in a hydrofluoric acid solution for 2 minutes and washed to obtain pretreated glass flakes. A silane coupling agent, water, and acetic acid were mixed, stirred, and allowed to stand for 20 minutes. The pretreated glass flakes, octamercapto POSS, and dibenzoyl peroxide were then added. The mixture was reacted at 100°C under an inert atmosphere for 3 hours, then quenched. The solid was collected by filtration and washed to obtain the modified glass flakes. The mass ratio of the pretreated glass flakes to the octamercapto POSS was 1:1.2. The volume ratio of the silane coupling agent, water, and acetic acid was 1:0.8:0.8.

[0047] 4. Prepare the wear-resistant PVC decorative film as follows:

[0048] S1, according to 100 parts of PVC resin, 20 parts of chlorinated polyethylene resin, 5 parts of plasticizer, 5 parts of lubricant, 10 parts of montmorillonite / nanosilica composite, and 5 parts of calcium zinc composite stabilizer; the raw materials of the PVC substrate layer are mixed and melt-extruded to obtain a PVC film;

[0049] S2, 100 parts of PET resin; 20 parts of polyisocyanate, 10 parts of acrylate copolymer, 5 parts of modified flaky aluminum oxide, 5 parts of modified glass flakes, 0.2 parts of dibutyltin dilaurate, the raw materials of the coating layer are mixed and melt-extruded to obtain a coating;

[0050] S3: In an atmosphere of oxygen and inert gas (N2), the surfaces of the PVC film and the coating to be bonded are subjected to plasma treatment at a power of 200 W·min / m² and a treatment time of 60 s. Subsequently, a silane coupling agent and a silicone adhesive are sequentially coated on the surfaces of the PVC film and the coating to be bonded; the amount of the coated silane coupling agent is 1wt% of the silicone adhesive, and the amount of the silicone adhesive coated is 1.5g / cm 2 .

[0051] S4, hot pressing and laminating at 110-120° C. (pressure 1.0 MPa, time 20 s), and cooling to obtain the wear-resistant PVC decorative film.

[0052] Example 2

[0053] 1. Prepare montmorillonite / nanosilica composites as follows:

[0054] In a mixed atmosphere of H2 and inert gas, nano-silica was calcined at 1200°C for 1.5 hours and then rapidly cooled to room temperature at a rate of 50°C / min to obtain hydrophobic nano-silica;

[0055] Montmorillonite, hexadecyltrimethylammonium bromide, and an ethanol solution were mixed and ultrasonically dispersed at 70°C for 2 hours. A silane coupling agent and the hydrophobic nano-silica were then added, ultrasonically dispersed for 20 minutes, centrifuged, vacuum-dried at 60°C, and ground to obtain the montmorillonite / nano-silica composite. The mass ratio of montmorillonite, hydrophobic nano-silica, hexadecyltrimethylammonium bromide, and ethanol was 1:0.8:0.3:0.5.

[0056] 2. Prepare modified flaky alumina as follows:

[0057] Nano-flaky γ-Al2O3 is mixed with toluene, heated and stirred uniformly under an inert atmosphere, and then a toluene solution of oleylamine is added dropwise, and the mixture is refluxed at 100°C for 3 hours. The mixture is then cooled, filtered, washed, vacuum-dried, and ground to obtain the modified flaky aluminum oxide. The amount of oleylamine added is 1 wt% of the nano-flaky γ-Al2O3.

[0058] 3. Prepare modified glass flakes as follows:

[0059] Glass flakes were immersed in a hydrofluoric acid solution for 1.5 minutes and washed to obtain pretreated glass flakes. A silane coupling agent, water, and acetic acid were mixed, stirred, and allowed to stand for 30 minutes. The pretreated glass flakes, octamercapto POSS, and dibenzoyl peroxide were then added. The mixture was reacted under an inert atmosphere at 80°C for 3 hours, then quenched, the solid was collected by filtration, and washed to obtain the modified glass flakes. The mass ratio of the pretreated glass flakes to the octamercapto POSS was 1:1.2. The volume ratio of the silane coupling agent, water, and acetic acid was 1:1:1.

[0060] 4. Prepare the wear-resistant PVC decorative film as follows:

[0061] S1, according to 90 parts of PVC resin, 10 parts of chlorinated polyethylene resin, 1 part of plasticizer, 1 part of lubricant, 5 parts of montmorillonite / nanosilica composite, and 1 part of calcium zinc composite stabilizer; the raw materials of the PVC substrate layer are mixed and melt-extruded to obtain a PVC film;

[0062] S2, 90 parts of PET resin; 10 parts of polyisocyanate, 5 parts of acrylate copolymer, 1 part of modified flaky aluminum oxide, 1 part of modified glass flakes, 0.1 part of dibutyltin dilaurate, the raw materials of the coating layer are mixed and melt-extruded to obtain a coating;

[0063] S3: In an atmosphere of oxygen and inert gas (N2), the surfaces of the PVC film and the coating to be bonded are subjected to plasma treatment at a power of 200 W·min / m² and a treatment time of 30 seconds. Subsequently, a silane coupling agent and a silicone adhesive are sequentially coated on the surfaces of the PVC film and the coating to be bonded; the amount of the coated silane coupling agent is 1wt% of the silicone adhesive, and the coating amount of the silicone adhesive is 1.5g / cm2.

[0064] S4, hot pressing and laminating at 110-120° C. (pressure 1.0 MPa, time 30 s), and cooling to obtain the wear-resistant PVC decorative film.

[0065] Example 3

[0066] 1. Prepare montmorillonite / nanosilica composites as follows:

[0067] In a mixed atmosphere of H2 and inert gas, nano-silica was calcined at 1200°C for 2 hours, and then rapidly cooled to room temperature at a rate of 50°C / min to obtain hydrophobic nano-silica;

[0068] Montmorillonite, hexadecyltrimethylammonium bromide, and an ethanol solution were mixed and ultrasonically dispersed at 70°C for 1 hour. A silane coupling agent and the hydrophobic nano-silica were then added and ultrasonically dispersed for 20 minutes. The mixture was centrifuged, vacuum-dried at 60°C, and ground to obtain a montmorillonite / nano-silica composite. The mass ratio of montmorillonite, hydrophobic nano-silica, hexadecyltrimethylammonium bromide, and ethanol was 1:0.8:0.3:0.5.

[0069] 2. Prepare modified flaky alumina as follows:

[0070] Nano-flaky γ-Al2O3 is mixed with toluene, heated and stirred uniformly under an inert atmosphere, and then a toluene solution of oleylamine is added dropwise, and the mixture is refluxed at 100°C for 3 hours. The mixture is then cooled, filtered, washed, vacuum-dried, and ground to obtain the modified flaky aluminum oxide. The amount of oleylamine added is 1 wt% of the nano-flaky γ-Al2O3.

[0071] 3. Prepare modified glass flakes as follows:

[0072] Glass flakes were immersed in a hydrofluoric acid solution for 2 minutes and washed to obtain pretreated glass flakes. A silane coupling agent, water, and acetic acid were mixed, stirred, and allowed to stand for 20 minutes. The pretreated glass flakes, octamercapto POSS, and dibenzoyl peroxide were then added. The mixture was reacted at 100°C under an inert atmosphere for 3 hours, then quenched. The solid was collected by filtration and washed to obtain the modified glass flakes. The mass ratio of the pretreated glass flakes to the octamercapto POSS was 1:1. The volume ratio of the silane coupling agent, water, and acetic acid was 1:0.8:1.

[0073] 4. Prepare the wear-resistant PVC decorative film as follows:

[0074] S1, according to 100 parts of PVC resin, 20 parts of chlorinated polyethylene resin, 5 parts of plasticizer, 5 parts of lubricant, 10 parts of montmorillonite / nanosilica composite, and 5 parts of calcium zinc composite stabilizer; the raw materials of the PVC substrate layer are mixed and melt-extruded to obtain a PVC film;

[0075] S2, 90 parts of PET resin; 10 parts of polyisocyanate, 5 parts of acrylate copolymer, 1 part of modified flaky aluminum oxide, 1 part of modified glass flakes, 0.1 part of dibutyltin dilaurate, the raw materials of the coating layer are mixed and melt-extruded to obtain a coating;

[0076] S3: In an atmosphere of oxygen and inert gas (N2), the surfaces of the PVC film and the coating to be bonded are subjected to plasma treatment at a power of 200 W·min / m² and a treatment time of 30 seconds. Subsequently, a silane coupling agent and a silicone adhesive are sequentially coated on the surfaces of the PVC film and the coating to be bonded; the amount of the coated silane coupling agent is 1wt% of the silicone adhesive, and the coating amount of the silicone adhesive is 1.5g / cm2.

[0077] S4, hot pressing and laminating at 110-120° C. (pressure 1.0 MPa, time 30 s), and cooling to obtain the wear-resistant PVC decorative film.

[0078] Example 4

[0079] 1. Prepare montmorillonite / nanosilica composites as follows:

[0080] calcining nano-silica at 1200°C for 1-2 hours in a mixed atmosphere of H2 and inert gas, and rapidly cooling to room temperature at a rate of 30-50°C / min to obtain hydrophobic nano-silica;

[0081] Montmorillonite, hexadecyltrimethylammonium bromide, and an ethanol solution are mixed and ultrasonically dispersed at 60-70°C for 1-2 hours. A silane coupling agent and the hydrophobic nano-silica are then added, ultrasonically dispersed for 10-20 minutes, centrifuged, vacuum-dried at 50-60°C, and ground to obtain the montmorillonite / nano-silica composite. The mass ratio of montmorillonite, hydrophobic nano-silica, hexadecyltrimethylammonium bromide, and ethanol is 1:0.8:0.3:0.5.

[0082] 2. Prepare modified flaky alumina as follows:

[0083] Nano-flaky γ-Al2O3 is mixed with toluene, heated and stirred uniformly under an inert atmosphere, and then a toluene solution of oleylamine is added dropwise, and the mixture is refluxed at 100°C for 3 hours. The mixture is then cooled, filtered, washed, vacuum-dried, and ground to obtain the modified flaky aluminum oxide. The amount of oleylamine added is 2.5 wt% of the nano-flaky γ-Al2O3.

[0084] 3. Prepare modified glass flakes as follows:

[0085] Glass flakes were immersed in a hydrofluoric acid solution for 1.5 minutes and washed to obtain pretreated glass flakes. A silane coupling agent, water, and acetic acid were mixed, stirred, and allowed to stand for 30 minutes. The pretreated glass flakes, octamercapto POSS, and dibenzoyl peroxide were then added. The mixture was reacted under an inert atmosphere at 80°C for 3 hours, then quenched, the solid was collected by filtration, and washed to obtain the modified glass flakes. The mass ratio of the pretreated glass flakes to the octamercapto POSS was 1:1.2. The volume ratio of the silane coupling agent, water, and acetic acid was 1:1:1.

[0086] 4. Prepare the wear-resistant PVC decorative film as follows:

[0087] S1, according to 90 parts of PVC resin, 10 parts of chlorinated polyethylene resin, 1 part of plasticizer, 1 part of lubricant, 5 parts of montmorillonite / nanosilica composite, and 1 part of calcium zinc composite stabilizer; the raw materials of the PVC substrate layer are mixed and melt-extruded to obtain a PVC film;

[0088] S2, 100 parts of PET resin; 20 parts of polyisocyanate, 10 parts of acrylate copolymer, 5 parts of modified flaky aluminum oxide, 5 parts of modified glass flakes, 0.2 parts of dibutyltin dilaurate, the raw materials of the coating layer are mixed and melt-extruded to obtain a coating;

[0089] S3: In an atmosphere of oxygen and inert gas (N2), the surfaces of the PVC film and the coating to be bonded are subjected to plasma treatment at a power of 200W·min / m² and a treatment time of 30-60s. Subsequently, a silane coupling agent and a silicone adhesive are sequentially coated on the surfaces of the PVC film and the coating to be bonded; the amount of the coated silane coupling agent is 1wt% of the silicone adhesive, and the coating amount of the silicone adhesive is 1.5g / cm2.

[0090] S4, hot pressing and laminating at 110-120° C. (pressure 1.0 MPa, time 30 s), and cooling to obtain the wear-resistant PVC decorative film.

[0091] Example 5

[0092] 1. Prepare montmorillonite / nanosilica composites as follows:

[0093] In a mixed atmosphere of H2 and inert gas, nano-silica was calcined at 1200°C for 2 hours, and then rapidly cooled to room temperature at a rate of 30°C / min to obtain hydrophobic nano-silica;

[0094] Montmorillonite, hexadecyltrimethylammonium bromide, and an ethanol solution were mixed and ultrasonically dispersed at 60°C for 1.5 hours. A silane coupling agent and the hydrophobic nano-silica were then added, ultrasonically dispersed for 15 minutes, centrifuged, vacuum-dried at 50°C, and ground to obtain the montmorillonite / nano-silica composite. The mass ratio of montmorillonite, hydrophobic nano-silica, hexadecyltrimethylammonium bromide, and ethanol was 1:1:0.5:0.5.

[0095] 2. Prepare modified flaky alumina as follows:

[0096] γ-Al2O3 and toluene are mixed, heated and stirred uniformly under an inert atmosphere; a toluene solution of oleylamine is then added dropwise, and the mixture is refluxed at 120°C for 3 hours. The mixture is cooled, filtered, washed, vacuum dried, and ground to obtain the modified flaky alumina. The amount of oleylamine added is 2 wt% of the γ-Al2O3.

[0097] 3. Prepare modified glass flakes as follows:

[0098] Glass flakes were immersed in a hydrofluoric acid solution for 2 minutes and washed to obtain pretreated glass flakes. A silane coupling agent, water, and acetic acid were mixed, stirred, and allowed to stand for 30 minutes. The pretreated glass flakes, octamercapto POSS, and dibenzoyl peroxide were then added. The mixture was reacted at 100°C under an inert atmosphere for 3 hours, then quenched. The solid was collected by filtration and washed to obtain the modified glass flakes. The mass ratio of the pretreated glass flakes to the octamercapto POSS was 1:1. The volume ratio of the silane coupling agent, water, and acetic acid was 1:0.8:0.8.

[0099] 4. Prepare the wear-resistant PVC decorative film as follows:

[0100] S1, according to 100 parts of PVC resin, 15 parts of chlorinated polyethylene resin, 3 parts of plasticizer, 3 parts of lubricant, 8 parts of montmorillonite / nanosilica composite, and 3 parts of calcium zinc composite stabilizer; the raw materials of the PVC substrate layer are mixed and melt-extruded to obtain a PVC film;

[0101] S2, 100 parts of PET resin; 15 parts of polyisocyanate, 8 parts of acrylate copolymer, 3 parts of modified flaky aluminum oxide, 3 parts of modified glass flakes, 0.2 parts of dibutyltin dilaurate, the raw materials of the coating layer are mixed and melt-extruded to obtain a coating;

[0102] S3: In an atmosphere of oxygen and inert gas (N2), the surfaces of the PVC film and the coating to be bonded are subjected to plasma treatment at a power of 200 W·min / m² and a treatment time of 50 seconds. Subsequently, a silane coupling agent and a silicone adhesive are sequentially coated on the surfaces of the PVC film and the coating to be bonded; the amount of the coated silane coupling agent is 1wt% of the silicone adhesive, and the coating amount of the silicone adhesive is 1.5g / cm2.

[0103] S4, hot pressing and laminating at 110-120° C. (pressure 1.0 MPa, time 10 s), and cooling to obtain the wear-resistant PVC decorative film.

[0104] Comparative Example 1

[0105] The difference from Example 1 is that montmorillonite and nano-silica are used instead of the montmorillonite / nano-silica composite in Example 1, and the mass ratio of montmorillonite to nano-silica is 1:0.8. The rest of the raw material ratios and preparation methods are the same as those in Example 1.

[0106] Comparative Example 2

[0107] The difference from Example 1 is that flaky alumina is used instead of the modified flaky alumina in Example 1, and glass flakes are used instead of the modified glass flakes in Example 1. The rest of the raw material ratios and preparation methods are the same as those in Example 1.

[0108] Comparative Example 3

[0109] The difference from Example 1 is that montmorillonite and nano-silica are used instead of the montmorillonite / nano-silica composite in Example 1, and the mass ratio of montmorillonite to nano-silica is 1:0.8; flaky alumina is used instead of the modified flaky alumina in Example 1; and glass flakes are used instead of the modified glass flakes in Example 1. The remaining raw material ratios and preparation methods are the same as those in Example 1.

[0110] Comparative Example 4

[0111] The difference from Example 1 is that, when preparing the wear-resistant PVC decorative film, in step S3, plasma treatment is not performed, and hot pressing and lamination are directly performed. The remaining raw material ratios and preparation methods are the same as those of Example 1.

[0112] It should be noted that in the above embodiments and comparative examples, the plasticizer used is dioctyl phthalate, the lubricant is calcium stearate, the calcium-zinc composite stabilizer is the PVC calcium-zinc stabilizer produced by Fujian Ruide Chemical Technology Co., Ltd., and the remaining raw materials not otherwise specified are purchased directly from the market.

[0113] Experimental example

[0114] 1. Bonding strength test

[0115] According to the method in GB / T529-2008, the tear strength of the films of Examples 1-5 and Comparative Examples 1-4 was tested, with each group tested 3 times and the average value was taken. The results are shown in Table 1.

[0116] 2. Peel strength test

[0117] According to the ASTM D903 standard, the peel strength of each film at 90° was tested. Each group was tested 3 times and the average value was taken. The results are shown in Table 1.

[0118] 3. Wear resistance test

[0119] With reference to GB1768-79 (89), the diameter of the grinding disc was 200 mm, the diameter of the center hole was 9 mm, and the films were ground 100 times after drying. The weight loss of the films was tested and the abrasion resistance was calculated. Each group was tested 3 times and the average value was taken. The results are shown in Table 1.

[0120] Table 1

[0121] Tear strength (KN / m) Peel strength (KN / m) Wear resistance (%) Example 1 84.3 2.63 3.21 Example 2 53.9 2.48 3.13 Example 3 85.2 2.57 3.24 Example 4 84.7 2.61 3.04 Example 5 85.3 2.45 3.11 Comparative Example 1 58.1 1.42 4.05 Comparative Example 2 57.2 1.35 8.72 Comparative Example 3 53.6 1.22 10.34 Comparative Example 4 75.6 2.03 3.46

[0122] It can be concluded from Table 1 that the PVC composite films of Examples 1-5 have excellent tear resistance, glass resistance and wear resistance.

[0123] In Comparative Example 1, the montmorillonite / nanosilica composite was not added, and the tear strength of the film decreased, and the peel strength and wear resistance also decreased. In Comparative Example 2, the modified flaky alumina and modified glass flakes were not added, and accordingly, the mechanical properties of the film decreased accordingly. In Comparative Example 3, the montmorillonite / nanosilica composite, modified flaky alumina, and modified glass flakes were not added. Compared with Comparative Examples 1 and 2, the mechanical properties of the composite film of Comparative Example 3 were the worst. It can be seen that the montmorillonite / nanosilica composite, modified flaky alumina, and modified glass flakes have a synergistic effect, working together to improve the mechanical properties of the film. In Comparative Example 4, the film was not plasma treated, and the tear strength and wear resistance of the film decreased slightly, and the peel strength also decreased to a certain extent, but the peel strength was higher than that of Comparative Examples 1-3.

[0124] In summary, the wear-resistant PVC film provided by the embodiment of the present invention is composed of a composite of a PVC substrate layer and a coating layer, and has good wear resistance and strong interlayer bonding. By adding a montmorillonite / nanosilica composite to the PVC base material, nanosilica can improve the mechanical properties of the PVC film. The layered structure of montmorillonite enables it to form an intercalation or peeling structure in the PVC matrix, effectively transferring stress and enhancing mechanical properties. Compounding montmorillonite and nanosilica can, on the one hand, avoid the agglomeration of nanosilica and improve the dispersibility of nanosilica in the PVC substrate. On the other hand, nanosilica is inserted into the montmorillonite layer, and the bonding strength between the two is high, which can improve the bonding strength between nanosilica and the substrate, reduce the overflow of nanosilica during the stress process, and improve the tensile properties of the PVC film.

[0125] Flaky aluminum oxide and glass flakes are added to the coating layer. The flaky structure particles are stacked and arranged on the surface of the film, which can provide the film with barrier properties and wear resistance. The glass flakes and flaky aluminum oxide are used together to enhance the synergy and jointly improve the wear resistance of the PVC film.

[0126] The preparation method provided by the present invention first performs plasma treatment on the surface of the PVC film and the coating, grafts oxygen-containing functional groups such as -OH, -COOH, etc. on the surface of the PVC film and the coating, and then coats the surface with a silane coupling agent and a silicone adhesive. Under the action of the silane coupling agent and hot pressing, the adhesive and the PVC film and the coating can form a chemical bond, thereby improving the interlayer bonding strength of the PVC film and the coating.

[0127] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

Claims

1. A wear-resistant PVC decorative film, characterized in that: It includes a PVC base material layer, an adhesive layer and a coating layer arranged in sequence; The PVC substrate layer comprises the following raw materials by weight: 90-100 parts of PVC resin, 10-20 parts of chlorinated polyethylene resin, 1-5 parts of plasticizer, 1-5 parts of lubricant, 5-10 parts of montmorillonite / nanosilica composite, and 1-5 parts of calcium zinc composite stabilizer; The coating layer comprises the following raw materials in parts by weight: 90-100 parts of PET resin; 10-20 parts of polyisocyanate, 5-10 parts of acrylate copolymer, 1-5 parts of modified flaky aluminum oxide, 1-5 parts of modified glass flakes, and 0.1-0.2 parts of dibutyltin dilaurate; The bonding layer is a silicone adhesive.

2. The wear-resistant PVC decorative film according to claim 1, characterized in that: The montmorillonite / nano-silica composite is prepared by the following method: In a mixed atmosphere of H2 and inert gas, nano-silica is calcined at 1200°C for 1-2 hours and then rapidly cooled to room temperature to obtain hydrophobic nano-silica; Montmorillonite, hexadecyltrimethylammonium bromide and ethanol solution are mixed, ultrasonically dispersed at 60-70° C. for 1-2 hours, and then a silane coupling agent and the hydrophobic nano-silica are added. The mixture is ultrasonically dispersed for 10-20 minutes, centrifuged, vacuum-dried at 50-60° C., and ground to obtain the montmorillonite / nano-silica composite.

3. The wear-resistant PVC decorative film according to claim 1, characterized in that: The modified flaky aluminum oxide is prepared as follows: The nano-flaky γ-Al2O3 is mixed with toluene, heated and stirred evenly under an inert atmosphere; then a toluene solution of oleamine is added dropwise, and the mixture is refluxed at 100-120°C for 2-3 hours; the mixture is cooled, filtered, washed, vacuum dried, and ground to obtain the modified flaky alumina.

4. The wear-resistant PVC decorative film according to claim 1, characterized in that: The amount of oleylamine added is 2-3 wt% of the nano-sheet γ-Al2O3.

5. The wear-resistant PVC decorative film according to claim 1, characterized in that: The modified glass flakes are prepared by the following method: Soak the glass flakes in a hydrofluoric acid solution for 1-2 minutes and wash them clean to obtain pretreated glass flakes; Mix the silane coupling agent, water and acetic acid, stir evenly, let it stand for 20-30 minutes, then add pretreated glass flakes, octamercapto POSS and dibenzoyl peroxide, react for 2-3 hours at 80-100°C in an inert atmosphere, quench the reaction, collect the solid by filtration, and wash to obtain the modified glass flakes.

6. The wear-resistant PVC decorative film according to claim 5, characterized in that: The mass ratio of pretreated glass flakes to octamercapto POSS is 1:(1-1.2).

7. A method for preparing the wear-resistant PVC decorative film according to any one of claims 1 to 6, characterized in that: It includes: S1, mixing the raw materials of the PVC substrate layer, and melt-extruding to obtain a PVC film; S2, mixing the raw materials of the coating layer, and melt-extruding to obtain a coating; S3, in an atmosphere of oxygen and inert gas, plasma treating the surfaces of the PVC film and the covering film to be bonded, and then sequentially coating the surfaces of the PVC film and the covering film to be bonded with a silane coupling agent and a silicone adhesive; S4, hot pressing and laminating at 110-120° C., and cooling to obtain the wear-resistant PVC decorative film.

8. The method for preparing the wear-resistant PVC decorative film according to claim 7, characterized in that: The power of the plasma treatment is 200-275 W·min / m², and the treatment time is 30-60s.

9. The method for preparing the wear-resistant PVC decorative film according to claim 7, characterized in that: In step S4, the hot pressing and laminating process is performed at a pressure of 0.5-1.0 MPa and for a time of 10-30 seconds.

10. The method for preparing the wear-resistant PVC decorative film according to claim 7, characterized in that: In step S3, the amount of the coated silane coupling agent is 0.5-1 wt % of the silicone adhesive.