Polyolefin base material paint surface invisible car cover

Abstract

The invention discloses a polyolefin base material paint surface invisible car cover which comprises a release layer, a pressure-sensitive adhesive layer, a first polyolefin modified layer, a thermoplastic plastic layer, a second polyolefin modified layer, a bottom coating, a self-repairing layer and a PET film for protection which are sequentially arranged from inside to outside. The release layer is any one of a PET release film and release paper; the thermoplastic plastic layer is any one of metallocene low-density polyethylene, polypropylene random copolymer and blends blended with other polyolefin. The coating has the characteristics of low price, durability, low use cost, high strength, high transparency, high extensibility, high weather resistance and good film pasting and self-repairing performance, and can be well applied to the use environment of the paint surface protective film.

Description

Technical Field

[0001] The invention relates to the technical field of automobile paint protection films, and in particular to a polyolefin-based paint-surface invisible car cover. Background Art

[0002] With the continuous improvement of people's living standards, the awareness of car paint protection has been continuously strengthened. In recent years, the domestic car paint protection film market has developed rapidly, but the imported TPU (thermoplastic polyurethane elastomer) paint protection film is expensive, and the cost of sticking it on a car is even more than 10,000 yuan. Although domestic TPU paint protection film is available, the price is still relatively high, so it is currently difficult to promote its large-scale use on ordinary commercial vehicles.

[0003] Looking back, the development of paint protection film can be divided into four stages. The first generation of paint protection film is polyurethane (PU), which was soon eliminated due to its poor weather resistance and yellowing. The second generation of paint protection film is polyvinyl chloride (PVC). Although the price is relatively low, it is not soft enough, resulting in poor tensile properties, unable to achieve a perfect hemming effect, and has a short service life and is prone to yellowing and cracking. The third generation of paint protection film is still PVC, but plasticizer is added to PVC, referred to as TPH. Although the material becomes soft, it is easy to become brittle and crack in winter due to the addition of volatile plasticizers, and its service life is only two to three years. The fourth generation of paint protection film is thermoplastic polyurethane (TPU), which has good strength, transparency, cold resistance, and elongation, but most TPUs are prone to yellowing and are very expensive, so their usage is limited. Although there are so-called TPUs that never yellow, they still need the test of time and are expensive.

[0004] In recent years, with the advancement of technology, the emergence of metallocene low-density polyethylene and polypropylene random copolymers has created good conditions for the production of high-strength, high-transparency, and high-elongation films, and can be used for automotive paint protection films. Summary of the invention

[0005] The purpose of the present invention is to provide a polyolefin-based paint-coated invisible car cover, which is inexpensive, durable, has low use cost, is suitable for the use environment of paint protection film, has the advantages of high strength, high transparency, high elongation, high weather resistance, and good film-sticking and self-repairing properties.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] A polyolefin-based paint invisible car cover, characterized in that it comprises a release layer, a pressure-sensitive adhesive layer, a first polyolefin modified layer, a thermoplastic plastic layer, a second polyolefin modified layer, a primer layer, a self-repairing layer, and a protective PET film arranged in sequence from the inside to the outside;

[0008] The release layer is any one of a PET release film and a release paper;

[0009] The thermoplastic plastic layer is any one of metallocene low-density polyethylene, polypropylene random copolymer, and a blend of polyolefins.

[0010] The preferred solutions are as follows:

[0011] Preferably, the first polyolefin modified layer, the thermoplastic plastic layer and the second polyolefin modified layer are three-layer co-extruded composite molding.

[0012] Preferably, the blend of other polyolefins is any one of ethylene, propylene, binary polymers of other olefins, and ternary polymers of other olefins.

[0013] Preferably, the first polyolefin modified layer and the second polyolefin modified layer are both a non-polar mixture of a blend of polyethylene and other polyolefins, and a polar mixture containing ethylene components.

[0014] Preferably: the first polyolefin modified layer and the second polyolefin modified layer are both polar mixtures containing ethylene components;

[0015] The polar mixture containing an ethylene component is any one of a copolymer of ethylene and acrylic acid, a copolymer of ethylene and vinyl acetate, and a copolymer of ethylene and its esters.

[0016] Preferably: the thermoplastic plastic layer accounts for 95% of the total thickness of the first polyolefin modified layer to the second polyolefin modified layer;

[0017] The first polyolefin modified layer and the second polyolefin modified layer account for 3.5% of the total thickness of the first polyolefin modified layer to the second polyolefin modified layer;

[0018] The pressure-sensitive adhesive layer accounts for 13% of the total thickness from the pressure-sensitive adhesive layer to the self-healing layer;

[0019] The self-healing layer accounts for 8% of the total thickness from the pressure-sensitive adhesive layer to the self-healing layer;

[0020] The total thickness from the pressure-sensitive adhesive layer to the self-healing layer is 160 to 220 μm.

[0021] Preferably, the pressure-sensitive adhesive layer is a liquid acrylic pressure-sensitive adhesive, and the liquid acrylic pressure-sensitive adhesive is added with fine granular glass beads, transparent powder, and organic fine granular powder;

[0022] The organic fine granular powder is any one of PMMA fine particles, transparent MBS, ABS, PS, and binary or ternary copolymer fine particles;

[0023] The size of organic fine granular powder ranges from 5 to 30μ.

[0024] Preferably: a permeability enhancer is added to the first polyolefin modified layer, the thermoplastic plastic layer, and the second polyolefin modified layer;

[0025] The amount of permeation enhancer used ranges from 0.3% to 0.5%.

[0026] Preferably: UV absorber, hindered amine light stabilizer and antioxidant are added to the first polyolefin modified layer, the thermoplastic plastic layer and the second polyolefin modified layer;

[0027] The dosage of UV absorber, hindered amine light stabilizer and antioxidant is between 0.2% and 1%.

[0028] In summary, the present invention has the beneficial effects of being inexpensive, durable, and of low use cost, being well suited for the use environment of the paint protection film, having the characteristics of high strength, high transparency, high elongation, high weather resistance, and good film-sticking and self-repairing properties. DETAILED DESCRIPTION

[0029] Embodiment 1:

[0030] A polyolefin-based paint-surface invisible car cover, comprising a release layer, a pressure-sensitive adhesive layer, a first polyolefin modified layer, a thermoplastic plastic layer, a second polyolefin modified layer, a primer layer, a self-repairing layer, and a protective PET film, which are sequentially arranged from the inside to the outside;

[0031] The release layer is any one of PET release film and release paper; the thermoplastic plastic layer is any one of metallocene low-density polyethylene, polypropylene random copolymer, and blends blended with other polyolefins; the blends blended with other polyolefins are any one of ethylene, propylene, binary polymers of other olefins, and ternary polymers of other olefins.

[0032] Embodiment 2:

[0033] A polyolefin-based paint-surface invisible car cover, comprising a release layer, a pressure-sensitive adhesive layer, a first polyolefin modified layer, a thermoplastic plastic layer, a second polyolefin modified layer, a self-repairing layer, and a protective PET film, which are sequentially arranged from the inside to the outside;

[0034] The release layer is any one of PET release film and release paper; the thermoplastic plastic layer is any one of metallocene low-density polyethylene, polypropylene random copolymer, and blends blended with other polyolefins; the blends blended with other polyolefins are any one of ethylene, propylene, binary polymers of other olefins, and ternary polymers of other olefins.

[0035] The first polyolefin modified layer, the thermoplastic plastic layer and the second polyolefin modified layer are three-layer co-extrusion composite molding. The co-extrusion composite molding is formed by using a plastic multi-layer co-extrusion film blowing machine and a multi-layer co-extrusion cast film molding. The advantage of cast film molding is that the transparency of the film is better than that of blown film molding, and the thickness deviation of the film is easier to control, but there is a difference in the longitudinal and transverse tensile strength. The longitudinal tensile strength of cast film molding is better than the transverse tensile strength, while the longitudinal and transverse tensile strengths of blown film molding are more balanced.

[0036] The first polyolefin modified layer and the second polyolefin modified layer are any one of a non-polar mixture of a blend of polyethylene and other polyolefins, a polar mixture containing ethylene, a blend of low-density polyethylene and other polymers containing ethylene, and a copolymer of low-density polyethylene and other polymers containing ethylene. The first polyolefin modified layer and the second polyolefin modified layer are polar mixtures containing ethylene;

[0037] The polar mixture containing an ethylene component is any one of a copolymer of ethylene and acrylic acid, a copolymer of ethylene and vinyl acetate, and a copolymer of ethylene and its esters.

[0038] Low-density polyethylene modification adopts physical blending, which is generally difficult to achieve performance requirements, so chemical modification is the first choice. In order to improve the compatibility with metallocene low-density polyethylene and increase adhesion, mature materials can be purchased on the market. For example, copolymers containing ethylene components can be used alone or blended with copolymers containing ethylene components. The purpose is to increase the adhesion to the pressure-sensitive adhesive layer and to increase the adhesion to the primer.

[0039] Examples of the modified polyolefins containing ethylene components include: copolymers of ethylene acrylic acid and esters, such as EAA ethylene acrylic acid, EEA ethylene ethyl acrylate, EBA ethylene butyl acrylate, EMA ethylene methyl acrylate, EMMA ethylene methyl methacrylate and ionic resins; copolymers of ethylene and vinyl acetate (EVA) with different vinyl acetate contents; copolymers of ethylene and other products containing polar groups can be used, such as copolymers of ethylene and maleic acid.

[0040] The pressure-sensitive adhesive layer is a liquid acrylic pressure-sensitive adhesive, and the pressure-sensitive adhesive layer, the primer layer, and the self-repairing layer are formed by coating;

[0041] High-viscosity acrylic pressure-sensitive adhesives are available on the market in two types: emulsion type and solvent type. It is better to use solvent type for paint protection film because solvent type acrylic pressure-sensitive adhesives can easily penetrate into the swollen modified polyolefin to improve adhesion. The disadvantage is that solvent is discharged during coating, which will pollute the environment. Emulsion type acrylic pressure-sensitive adhesives are currently developing rapidly and can replace solvent type acrylic pressure-sensitive adhesives, which is beneficial to environmental protection. There is also a new coating process for UV-curing acrylic pressure-sensitive adhesives without solvent emissions, which will not be described in detail here.

[0042] Due to the poor water and moisture permeability of polyolefin, bubbles are easily generated between the invisible car cover and the paint. These bubbles are actually water vapor generated by spraying water when the film is applied. For this reason, without affecting the transparency of the paint protective film, fine granular glass beads, transparent powder, and organic fine granular powder are added to the liquid acrylic pressure-sensitive adhesive, which can accelerate the removal of the steam generated by spraying water when the film is applied under sunlight. The principle is that after adding fine granular beads, fine unevenness is generated on the surface of the acrylic pressure-sensitive adhesive, and tiny gaps are generated between the surface of the car body paint, that is, a channel that can remove water vapor is formed.

[0043] Organic fine granular powder can also be added to the acrylic pressure-sensitive adhesive. The organic fine granular powder is any one of PMMA fine particles, transparent MBS, ABS, PS, and their binary and ternary copolymer fine particles. Its refractive index is equivalent to that of polyolefin, and its softness is better than that of inorganic fine particles, and it will not significantly affect the transparency of the paint protective film.

[0044] In addition to adding fine granular glass beads and organic fine particles to the liquid adhesive as mentioned above, the liquid acrylic adhesive can also be coated, heated in a drying oven, fully cured and cooled, and the acrylic adhesive layer and PET release film or release paper are compounded and embossed together before being fully cooled and rolled up. At this time, fine unevenness is also produced on the surface of the adhesive layer. The embossing depth of the acrylic pressure-sensitive adhesive layer can refer to the size of the fine particles. The size range of the organic fine granular powder is 5 to 30μ, and the best effect can be achieved at 10 to 20μ.

[0045] You can also use any of the PET release film and release paper that have been embossed in advance, which can have the same effect after being compounded with the acrylic pressure-sensitive adhesive layer. When the PET release film and release paper are torn off during film application, the unevenness of the acrylic pressure-sensitive adhesive layer can effectively discharge water vapor under sunlight, eliminating the so-called bubbles.

[0046] The above two methods can effectively eliminate the bubbles generated when spraying water on the film under sunlight, and the best bonding effect can be obtained by drying it for several days. After coating using the above method, the glue side is compounded with a layer of PET release film and release paper, which can be easily peeled off during on-site construction, making it convenient for pasting construction.

[0047] The thermoplastic plastic layer accounts for 95% of the total thickness of the first polyolefin modified layer to the second polyolefin modified layer;

[0048] The first polyolefin modified layer and the second polyolefin modified layer account for 3.5% of the total thickness from the first polyolefin modified layer to the second polyolefin modified layer; the pressure-sensitive adhesive layer accounts for 13% of the total thickness from the pressure-sensitive adhesive layer to the self-repairing layer; the self-repairing layer accounts for 8% of the total thickness from the pressure-sensitive adhesive layer to the self-repairing layer; the total thickness from the pressure-sensitive adhesive layer to the self-repairing layer is 160 to 220 μ.

[0049] The first polyolefin modified layer, the thermoplastic plastic layer and the second polyolefin modified layer are added with a transmittance enhancer; the dosage of the transmittance enhancer ranges from 0.3% to 0.5%; the first polyolefin modified layer, the thermoplastic plastic layer and the second polyolefin modified layer are added with a UV absorber, a hindered amine light stabilizer and an antioxidant; the dosage of the UV absorber, the hindered amine light stabilizer and the antioxidant ranges from 0.2% to 1%.

[0050] The thermoplastic plastic layer with the highest material consumption in the present invention, i.e. any one of the relatively low-priced metallocene low-density polyethylene, polypropylene random copolymer, and blends with other polyolefins, no longer uses expensive thermoplastic polyurethane (TPU), which not only reduces the cost but also has better suitability for the use environment of the paint protection film, i.e., it has high strength, high transparency, high elongation, high weather resistance, and good film-sticking and self-repairing properties.

[0051] Therefore, the patent of the present invention effectively overcomes the disadvantage of expensive raw materials in the prior art and has high industrial utilization value.

[0052] The materials used in the patent of the present invention are: mLLDPE8315, EAA1321, acrylate glue 3440-01, self-repairing coating D061, primer UK U-09LV, permeability enhancer HPN20E, solvent-resistant PMMA KM-5000 fine particles, UV absorber 531, hindered amine light stabilizer 2020, antioxidant 1010; the above materials are mixed evenly according to the prescribed ratio using a low-speed mixer, and then added into the hopper or tray on the corresponding extrusion equipment.

[0053] The experimental equipment used is a three-layer co-extrusion casting machine with a width of 500mm, an extrusion temperature of 180-200℃, a film thickness of 145-155μ, both sides of the film can be corona treated, and the surface tension is not less than 38 dynes; then a solvent-based coating machine with a width of 500mm is used to coat the corresponding acrylic pressure-sensitive adhesive and self-healing agent on both sides of the middle layer of the three-layer co-extrusion, as well as the necessary PET release film. The testing equipment for raw materials and finished products mainly includes melt index meter, general tensile testing machine, heat aging oven, UV aging tester, high and low temperature environmental test chamber, and microscope for detecting the thickness of each layer.

[0054] The processing process of embodiment 1 is as follows:

[0055] Step 1: co-extrusion (film blowing, casting, corona treatment) of the first polyolefin modified layer, the thermoplastic plastic layer, and the second polyolefin modified layer;

[0056] Step 2, rolling down after film formation;

[0057] Step 3, coating a second pressure-sensitive adhesive layer;

[0058] Step 4, compounding the embossed release layer;

[0059] Step 5, rolling up the semi-finished product after compounding;

[0060] Step six, apply the sixth layer of primer;

[0061] Step 7, roll down after coating;

[0062] Step 8, applying the seventh self-repairing layer;

[0063] Step nine, compounding a protective PET film on the coated self-repairing layer;

[0064] Step 10, roll up the finished product.

[0065] The processing process of the second embodiment is as follows:

[0066] Step 1, co-extrusion (blowing film or casting or corona treatment) of the first polyolefin modified layer, the thermoplastic plastic layer and the second polyolefin modified layer;

[0067] Step 2, rolling down after film formation;

[0068] Step 3, coating a second pressure-sensitive adhesive layer;

[0069] Step 4, compounding the embossed release layer;

[0070] Step 5, rolling up the semi-finished product after compounding;

[0071] Step six, directly apply the seventh self-repairing layer;

[0072] Step 7, compounding a protective PET film on the coated self-repairing layer;

[0073] Step eight, roll up the finished product.

[0074] Among them, the present invention produces an invisible car cover with a total thickness of 190μ by mixing different materials, namely Experiment 1 to Experiment 7, and Comparative Examples 1 to Comparative Examples 3, as shown in the table below.

[0075]

[0076]

[0077] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the relevant technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A polyolefin-based paint-surface invisible car cover, characterized in that: It includes a release layer, a pressure-sensitive adhesive layer, a first polyolefin modified layer, a thermoplastic plastic layer, a second polyolefin modified layer, a primer layer, a self-repairing layer, and a protective PET film which are sequentially arranged from the inside to the outside; The release layer is any one of a PET release film and a release paper; The thermoplastic plastic layer is any one of metallocene low-density polyethylene, polypropylene random copolymer, and a blend of polyolefins.

2. The polyolefin-based paint-surface invisible car cover according to claim 1, characterized in that: The first polyolefin modified layer, the thermoplastic plastic layer and the second polyolefin modified layer are three-layer co-extrusion composite molding.

3. The polyolefin-based paint-surface invisible car cover according to claim 2, characterized in that: The other polyolefin blend is any one of ethylene, propylene, binary polymers of other olefins, and ternary polymers of other olefins.

4. The polyolefin-based paint-surface invisible car cover according to claim 3, characterized in that: The first polyolefin modified layer and the second polyolefin modified layer are both a non-polar mixture of a blend of polyethylene and other polyolefins or a polar mixture containing an ethylene component.

5. The polyolefin-based paint-surface invisible car cover according to claim 4, characterized in that: The first polyolefin modified layer and the second polyolefin modified layer are both polar mixtures containing ethylene components; The polar mixture containing an ethylene component is any one of a copolymer of ethylene and acrylic acid, a copolymer of ethylene and vinyl acetate, and a copolymer of ethylene and its esters.

6. The polyolefin-based paint-surface invisible car cover according to claim 5, characterized in that: The thermoplastic plastic layer accounts for 95% of the total thickness of the first polyolefin modified layer to the second polyolefin modified layer; The first polyolefin modified layer and the second polyolefin modified layer account for 3.5% of the total thickness of the first polyolefin modified layer to the second polyolefin modified layer; The pressure-sensitive adhesive layer accounts for 13% of the total thickness from the pressure-sensitive adhesive layer to the self-healing layer; The self-healing layer accounts for 8% of the total thickness from the pressure-sensitive adhesive layer to the self-healing layer; The total thickness from the pressure-sensitive adhesive layer to the self-healing layer is 160 to 220 μm.

7. The polyolefin-based paint-surface invisible car cover according to claim 6, characterized in that: The pressure-sensitive adhesive layer is a liquid acrylic pressure-sensitive adhesive, to which fine granular glass beads, transparent powder, and organic fine granular powder are added; The organic fine granular powder is any one of PMMA fine particles, transparent MBS, ABS, PS, and binary or ternary copolymer fine particles; The size of organic fine granular powder ranges from 5 to 30μ.

8. The polyolefin-based paint-surface invisible car cover according to claim 7, characterized in that: The first polyolefin modified layer, the thermoplastic plastic layer, and the second polyolefin modified layer are added with a permeability enhancer; The amount of permeation enhancer used ranges from 0.3% to 0.5%.

9. The polyolefin-based paint-surface invisible car cover according to claim 8, characterized in that: UV absorber, hindered amine light stabilizer and antioxidant are added to the first polyolefin modified layer, the thermoplastic plastic layer and the second polyolefin modified layer; The dosage of UV absorber, hindered amine light stabilizer and antioxidant is between 0.2% and 1%.

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