Car cover and spraying construction method thereof

Abstract

The present application relates to the technical field of car covers, and specifically to a car cover and a spraying construction method thereof. The present application discloses a spraying construction method for a car cover, comprising the following steps: (1) cleaning and degreasing the car body; (2) masking the parts of the car body that do not need to be sprayed; (3) spraying an isolation primer; (4) spraying a transition layer material; (5) spraying a car cover film material; (6) spraying a protective layer material; and (7) post-processing the car body. The present application also discloses a car cover prepared by the above-mentioned spraying construction method for a car cover. The spraying construction method for the car cover of the present application is not only convenient to construct and easy to change color, and does not require a baking process, but also solves the curling problem that is easy to occur in the assembly and molding of the car cover and the problem that the back glue is difficult to peel off, and greatly reduces the construction time and cost, and improves the molding effect of the car cover.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle covers, and in particular to a vehicle cover and a spraying construction method thereof. Background Art

[0002] In order to protect the vehicle, extend the service life of the vehicle, and maintain the beauty and freshness of the vehicle's appearance, more and more people choose to cover the surface of the vehicle with a layer of car cover.

[0003] Currently, there are many types of car covers on the market, including TPU, PVC, and TPH. Invisible TPU and color-changing TPU car covers are the most commonly used because of their excellent mechanical properties and weather resistance, effectively protecting the vehicle's paint from pollution, corrosion, and minor scratches. However, existing TPU car covers also have some disadvantages:

[0004] (1) Due to the complicated production process of TPU car cover, which goes through a series of process steps such as granulation of isocyanate and polyol resin to TPU particles, TPU particle casting to prepare film material, film material gluing, and film material coating, the overall cost of TPU car cover film is relatively high;

[0005] (2) TPU color-changing car covers require adding color to the TPU film. Therefore, every time a user requires a color, the manufacturer must produce a large batch of film materials of that color on the production line. On the one hand, this causes a large backlog of inventory in the production and circulation links. On the other hand, the actual colors available to consumers are not rich, making it difficult to meet more personalized customization needs.

[0006] (3) The installation of TPU invisible car covers and TPU color-changing car covers is currently done manually, which is a cumbersome process with high labor costs, and there is no possibility of automation in the short term;

[0007] (4) When TPU invisible car covers and TPU color-changing car covers are attached to the curved surface of the car body, it is easy to cause curling due to stress, which affects the final molding effect;

[0008] (5) High-end TPU invisible car covers pursue thickness to improve protection capabilities, but TPU car cover films with a thickness of more than 300-400 microns are actually very difficult to stretch during construction, and it is impossible to increase the thickness further.

[0009] Therefore, the long construction time of TPU car covers, excessive reliance on the skills and experience of construction workers, high costs, and difficulty in meeting personalized customization needs have seriously restricted the development of TPU car covers and are also problems that need to be urgently solved in this field. Summary of the Invention

[0010] To solve the above technical problems, the present application provides a spray coating construction method for a car cover. By adopting a spray coating method to realize the molding of a TPU car cover, the cost is reduced, the construction time is shortened, and the molding quality of the car cover is improved.

[0011] In a first aspect, the present application provides a method for spraying a car cover.

[0012] A method for spraying a car cover comprises the following steps: (1) cleaning and degreasing the car body; (2) masking the parts of the car body that do not need to be sprayed; (3) spraying an isolation primer; (4) spraying a transition layer material; (5) spraying a car cover film material; (6) spraying a protective layer material; and (7) post-processing the car body.

[0013] Furthermore, the isolation primer comprises oligomers, hydrogenated C5 petroleum resin and organic solvent; the oligomers are synthesized by reacting isocyanate prepolymer and terminal hydroxyl polyester in a molar ratio of 1: (1.6-1.8) and have an average molecular weight of 1.0×10 4 ~1.2×10 4 The isocyanate prepolymer is a prepolymer with an average molecular weight of 3500 synthesized by reacting hydrogenated hydroxyl-terminated polybutadiene with an average molecular weight of 3000 and isophorone diisocyanate in a molar ratio of 1: (1.9 to 2.1); the hydroxyl-terminated polyester is a hydroxyl-terminated polyester with a molecular weight between 2000 and 2500 synthesized by reacting hydrogenated bisphenol A and 1,4-cyclohexanedicarboxylic acid in a molar ratio of 1: (0.8 to 0.85).

[0014] Preferably, the organic solvent includes xylene, toluene, ethylbenzene, butyl acetate, tert-butyl acetate, isobutyl acetate, and ethyl acetate. More preferably, the organic solvent comprises 15% to 20% xylene and 25% to 30% butyl acetate, based on the mass percentage of the stripping primer. Using a combination of xylene and butyl acetate as the organic solvent improves dissolution of oligomers and hydrogenated C5 petroleum resin, allowing for better adjustment of the primer's viscosity and workability, making it more adaptable to different usage scenarios.

[0015] Furthermore, the spraying operation of step (3) is specifically as follows: when spraying, a 1.3mm caliber pneumatic spray gun is used to first spray the isolation primer once using a mist spray method, and then the isolation primer is sprayed again using a medium wet spray method, so that the thickness of the isolation primer layer reaches 10 microns.

[0016] By using a 1.3mm caliber spray gun, the entire car can be sprayed in the shortest possible time. A spray gun with a caliber that is too small will prolong the spraying time; a spray gun with a caliber that is too large will cause sagging. If the thickness of the isolation primer layer is too thin, uneven thickness, dissolution during subsequent spraying, and other factors may cause the TPU car cover film material to contact the car paint surface. This will cause excessive adhesion and make it impossible to tear off the TPU car cover. This problem will not occur when the average thickness of the primer reaches 10 microns or more. In addition, since the primer itself does not have high elasticity and strength and only has moderate adhesion, increasing the primer thickness is meaningless and will increase costs and extend spraying time.

[0017] Furthermore, the transition layer material is obtained by mixing the isolation primer and the HDI dimer in a mass ratio of 10:1.

[0018] Since the adhesion between TPU car cover film material and isolation primer is low, by adding isocyanate components to the transition layer material, the transition layer can be chemically cross-linked with the car cover film, greatly improving the adhesion.

[0019] Furthermore, the spraying operation of step (4) is specifically as follows: during spraying, a pneumatic spray gun with a caliber of 1.5 mm is used to spray the transition layer once using a wet spraying method, so that the thickness of the transition layer reaches 20 microns.

[0020] Using a 1.5mm caliber spray gun makes spraying easier. Because the transition layer material contains isocyanate (HDI dimer), the material viscosity is higher than that of the isolation primer, so a larger caliber spray gun should be used to achieve the required thickness of 20 microns.

[0021] Since the TPU car cover material has low adhesion to the isolation primer, if the transition layer is too thin, on the one hand, there will be problems such as discontinuous paint film and inconsistent thickness. On the other hand, it may also cause the TPU car cover film to have too low adhesion, and when tearing off the film, the car cover film alone will be torn off and the isolation primer will remain on the car body; therefore, the transition layer must reach a certain thickness.

[0022] Furthermore, after spraying the transition layer, the car cover film should be sprayed within 15 minutes to 24 hours.

[0023] Furthermore, the car cover film material includes component A and component B; the component A is composed of isocyanate and solvent, and the isocyanate is selected from any one or more of hydrogenated MDI, HDI dimer or HDI trimer; the component B is composed of polycaprolactone diol, polycaprolactone triol, solvent and catalyst stannous octoate.

[0024] Preferably, the organic solvent may be selected from: xylene, ethylbenzene, butyl acetate, tert-butyl acetate, isobutyl acetate, ethyl acetate, etc.; preferably, the molecular weight of polycaprolactone triol is 1000-3000; more preferably, the solvent in component A accounts for 30-45% of the mass of isocyanate; the solvent in component B accounts for 30-45% of the total mass of polycaprolactone diol and polycaprolactone triol; and the catalyst accounts for 0.02-0.04% of the total mass of isocyanate, polycaprolactone diol and polycaprolactone triol.

[0025] Furthermore, the car cover film material optionally includes a color paste raw material, and the color paste raw material does not contain any resin.

[0026] By adding color paste to the car cover film material, it is easy to customize car covers of various colors, providing consumers with more options for personalized color-changing car covers.

[0027] Furthermore, the spraying operation of step (5) is specifically as follows: during spraying, component A and component B are added to the material barrel of a two-component polyurethane sprayer in a mass ratio of 1:1, the material temperature is set to 95-105°C, and component A and component B collide and mix at the outlet of the spray gun and then are immediately sprayed onto the vehicle body.

[0028] By mixing component A and component B at the outlet of the spray gun, it is possible to avoid the problem of pre-mixing and chemical reaction between the two, which will cause the viscosity to increase rapidly and gel within 20 minutes.

[0029] Furthermore, the car cover film material in step (5) should be sprayed 3-5 times to make the car cover film layer thickness reach 200-300 microns.

[0030] Furthermore, the protective layer material is made of fluorine-modified hydroxy acrylic resin and HDI trimer, and the fluorine-modified hydroxy acrylic resin is obtained by free radical copolymerization of 2-5% perfluorohexylethyl acrylate, 18-22% hydroxyethyl methacrylate, 40-50% isobornyl methacrylate, 10-15% methyl methacrylate, and 15-20% isooctyl methacrylate in butyl acetate.

[0031] Furthermore, solvents such as butyl acetate or xylene, UV absorbers, light stabilizers, and leveling agents are added to the fluorine-modified hydroxy acrylic resin, and then mixed with the HDI trimer for use.

[0032] Preferably, the protective layer material is a mixture of fluorine-modified hydroxy acrylic resin, HDI trimer, butyl acetate, and xylene in a mass ratio of (40-50):(8-12):(20-30):(15-25).

[0033] Furthermore, the spraying operation of step (6) is specifically as follows: using a 1.3 mm caliber pneumatic spray gun, wet spraying the protective layer material twice to make the protective layer thickness reach 60 microns.

[0034] Furthermore, the construction environment temperature of steps (3) to (6) is 25-35°C.

[0035] The car cover film material can be formed and solidified by spraying at room temperature, avoiding the need for high-temperature baking at 40-50°C. It is easier, more convenient and saves costs.

[0036] Furthermore, step (7) vehicle body post-processing is specifically as follows: after spraying, let it stand for 3 hours, then remove the masking film; after 24 hours, polish the surface to deal with defects.

[0037] Through further polishing, some dust spots and defects that appear during the spraying process can be removed, thereby improving the overall appearance quality of the car cover.

[0038] In a second aspect, the present application provides a car cover.

[0039] A car cover is prepared by adopting the above-mentioned spraying construction method of the car cover.

[0040] The beneficial technical effects brought about by this application are:

[0041] As can be seen from the above technical solutions, this application provides a method for spraying car covers. Compared with the existing technology, this application has the following obvious advantages:

[0042] (1) The present application uses a spraying method to form the TPU car cover, which is easy to construct and can perfectly fit the car cover on the curved surface of the vehicle. This not only solves the curling problem that is easy to occur during the assembly and molding of the car cover, but also greatly shortens the construction time and production costs.

[0043] (2) This application can easily change the color of car covers by adding colorants to the car covers, meeting the diverse customization needs of consumers;

[0044] (3) The selection of raw materials for each layer of the car cover of the present application allows construction to be performed at room temperature only, without the need for baking and other processes, which greatly saves construction time and cost;

[0045] (4) The present application arranges the isolation primer, transition layer, car cover film and protective layer in sequence, and combines the selection of specific construction conditions to not only ensure the molding effect of the car cover film, but also ensure that the car cover film can be completely peeled off without damaging the car paint, thus solving the problem that the back glue of the film car cover is difficult to peel off. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application. All raw materials used in the embodiments and comparative examples are common commercially available products unless otherwise specified.

[0047] Preparation Example 1 - Preparation of Isolation Primer

[0048] An isolation primer comprises 45 kg of oligomer, 10 kg of hydrogenated C5 petroleum resin, 15 kg of xylene and 30 kg of butyl acetate. The isolation primer is obtained by uniformly mixing the components.

[0049] The oligomers were prepared using the following method:

[0050] Hydrogenated bisphenol A and 1,4-cyclohexanedicarboxylic acid were mixed in a molar ratio of 1:0.8, and melt-polycondensed at 235°C for 7 hours under nitrogen protection to obtain a hydroxyl-terminated polyester with a molecular weight between 2000 and 2500.

[0051] The hydrogenated hydroxy-terminated polybutadiene with an average molecular weight of 3000 and isophorone diisocyanate were mixed in a molar ratio of 1:1.9 and reacted at 80°C for 10 hours to obtain a prepolymer with an average molecular weight of 3500.

[0052] The prepolymer and the hydroxyl-terminated polyester were mixed in a molar ratio of 1:1.6 and reacted at 90 °C for 10 h to obtain a prepolymer with an average molecular weight of 1.0×10 4 ~1.2×10 4 of oligomers.

[0053] Preparation Example 2 - Preparation of transition layer material

[0054] The isolation primer prepared in Preparation Example 1 and HDI dimer were mixed in a mass ratio of 10:1 to obtain the isolation primer.

[0055] Preparation Example 3 - Preparation of car cover film material

[0056] The car cover film material includes component A and component B.

[0057] Component A is a mixture of isocyanate and ethyl acetate in a mass ratio of 1:0.4;

[0058] The mass ratio of polycaprolactone diol, polycaprolactone triol and butyl acetate in component B is 1:1:0.6, and the catalyst stannous octoate accounts for 0.02% of the total mass of isocyanate, polycaprolactone diol and polycaprolactone triol.

[0059] Preparation Example 4 - Preparation of protective layer material

[0060] A protective layer material is prepared by mixing fluorine-modified hydroxy acrylic resin, HDI trimer, butyl acetate and xylene in a mass ratio of 45:10:25:20.

[0061] The fluorine-modified hydroxy acrylic resin is obtained by free radical copolymerization of 2% perfluorohexylethyl acrylate, 18% hydroxyethyl methacrylate, 50% isobornyl methacrylate, 10% methyl methacrylate and 20% isooctyl methacrylate in butyl acetate.

[0062] No other additives were added to the protective layer material in this preparation example. In other preparation examples, appropriate amounts of UV absorbers, light stabilizers, leveling agents, and other additives may also be added to further enhance the anti-aging effect.

[0063] Example 1

[0064] A spraying construction method for a car cover comprises the following steps:

[0065] (1) Cleaning and degreasing the vehicle body: clean the vehicle surface and wipe it with degreaser to remove surface oil stains; then rinse it again with water;

[0066] (2) Use masking film to cover the parts of the car body that do not need to be sprayed (such as windows, lights, etc.); control the construction environment temperature at around 25℃-35℃;

[0067] (3) Spraying isolation primer:

[0068] When spraying, use a 1.3mm caliber pneumatic spray gun, first spray the isolation primer once with a mist spray method, and then spray the isolation primer again with a medium wet spray method, so that the thickness of the isolation primer layer reaches 10 microns;

[0069] (4) Spraying transition layer material:

[0070] When spraying, use a 1.5mm diameter pneumatic spray gun and wet spray to apply the transition layer once, so that the transition layer thickness reaches 20 microns. After spraying, let it stand for 15 minutes before spraying the car cover film material;

[0071] (5) Spraying car cover film materials:

[0072] When spraying, add component A and component B in a mass ratio of 1:1 into the material barrel of a two-component polyurethane sprayer. Set the material temperature to 100°C. After the components A and B collide and mix at the outlet of the spray gun, immediately spray them onto the car body. Spray four times to make the car cover film layer thickness reach 200 microns.

[0073] (6) Spraying protective layer material:

[0074] Use a 1.3mm diameter pneumatic spray gun to wet spray the protective layer material twice to make the protective layer thickness reach 60 microns;

[0075] (7) Body post-processing:

[0076] After the protective layer is sprayed, let it stand for 3 hours and then remove the masking film; after 24 hours, polish the surface to deal with defects.

[0077] Example 2

[0078] The difference from Example 1 is that a 1.0 mm caliber pneumatic spray gun is used during spraying in step (3).

[0079] Example 3

[0080] The difference from Example 1 is that a 1.5 mm caliber pneumatic spray gun is used during spraying in step (3).

[0081] Example 4

[0082] The difference from Example 1 is that a 1.3 mm caliber pneumatic spray gun is used during spraying in step (4).

[0083] Example 5

[0084] The difference from Example 1 is that during spraying in step (4), the thickness of the transition layer reaches 10 microns.

[0085] Example 6

[0086] The difference from Example 1 is that during spraying in step (4), the thickness of the transition layer reaches 30 microns.

[0087] Comparative Example 1

[0088] The difference from Example 1 is that step (3) of spraying the isolation primer is omitted.

[0089] Comparative Example 2

[0090] The difference from Example 1 is that step (4) of spraying the transition layer material is omitted.

[0091] Comparative Example 3

[0092] The difference from Example 1 is that in step (5), A and B are mixed before spraying.

[0093] Comparative Example 4

[0094] The difference from Example 1 is that step (6) of spraying the protective layer material is omitted.

[0095] Comparative Example 5

[0096] Commercially available film TPU car cover.

[0097] Performance testing

[0098] 1.1 Car film strength test

[0099] Test method: Film hardness test (pencil method) GB / T 6739-2006.

[0100] 1.2 Car film toughness test

[0101] Test method: GB / T6742-2007.

[0102] 1.3 Bond strength

[0103] Test method: According to the above embodiment and comparative example, the car cover was sprayed on the car panel with the original paint surface, and then the bonding strength (MPa) between the car cover and the car panel with the original paint surface was tested.

[0104] 1.4 Peeling condition detection

[0105] Test method: peel the car covers prepared in the above examples and comparative examples from the car panel, record the peeling feel and observe the residual glue on the peeled surface of the car panel.

[0106] 1.5 Bond strength after aging

[0107] Test method: According to the above embodiment and comparative example, the car cover was sprayed on the car panel with the original paint finish. After 1000 hours of xenon lamp irradiation, the adhesion strength (MPa) between the aged car cover and the car panel with the original paint finish was tested.

[0108] 1.6 Peeling test after aging

[0109] Test method: According to the above examples and comparative examples, the car cover was sprayed on the car panel with the original paint finish. After 1000 hours of xenon lamp irradiation, the aged car cover was peeled off the car panel. The peeling feel was recorded and the residual glue on the peeled surface of the car panel was observed.

[0110] Table 1

[0111]

[0112]

[0113] Combining the above examples, comparative examples and Table 1, it can be seen that

[0114] In terms of film strength and toughness, Examples 1-6 all achieved the same strength and toughness as traditional TPU car covers, or even achieved better strength. Comparative Examples 1-4 exhibited varying degrees of reduced film hardness due to the lack of a release primer, transition layer material, or protective layer material, or the mixing of the film materials prior to spraying.

[0115] From the perspective of bonding strength and peeling, comparing Examples 1-3, if the caliber of the spray gun is too large, it will cause sagging, and if the caliber of the spray gun is too small, the spraying time will be extended. Comparing Example 1 with Example 4, Example 4 uses a spray gun with a smaller caliber, which makes construction inconvenient, because the transition layer material adds HDI dimer on the basis of the isolation primer, so the viscosity of the material liquid is greater than that of the isolation primer, and a larger caliber spray gun is used for easy construction. Comparing Example 1 with Comparative Example 2, Example 5, and Example 6, if there is no transition layer or the transition layer is too thin, the adhesion between the car cover film and the primer is small, and it is easy to fall off from the vehicle surface; the transition layer exceeding 20 microns has no effect on the adhesion, so it is not necessary to keep increasing the thickness of the transition layer. Comparing Example 1 with Comparative Example 1, when there is no isolation primer, the car cover film is not easy to peel off from the vehicle surface, leaving residual glue, which will affect the next replacement of the car cover. Comparing Example 1 with Comparative Example 3, the car cover film material is easy to solidify, affecting the molding quality of the car cover film. Comparing Example 1 with Comparative Example 4, the car cover has better anti-aging performance after the protective layer material is sprayed. Compared with Example 1 and Comparative Example 5, the spray-on car cover of the present application is easier to tear off than the traditional film-applied TPU car cover, and there is no residual glue, making it more convenient to replace the car cover.

[0116] The above embodiments are only used to illustrate the present application and are not intended to limit the technical solutions described in the present application; therefore, ordinary technicians in this field can modify or replace the present application with equivalents; and all technical solutions and improvements that do not depart from the essential content of the present application should be included in the scope of the claims of the present application.

Claims

1. A spraying construction method for a car cover, characterized in that: The following steps are involved: (1) Car body cleaning and degreasing; (2) Mask the parts of the vehicle body that do not need to be sprayed; (3) Spraying isolation primer; the isolation primer comprises oligomer, hydrogenated C5 petroleum resin and organic solvent; the oligomer is synthesized by reacting isocyanate prepolymer and terminal hydroxyl polyester in a molar ratio of 1: (1.6-1.8) with an average molecular weight of 1.0×10 4 ~1.2×10 4 The isocyanate prepolymer is a prepolymer with an average molecular weight of 3500 synthesized by reacting hydrogenated hydroxyl-terminated polybutadiene with an average molecular weight of 3000 and isophorone diisocyanate at a molar ratio of 1: (1.9-2.1); the hydroxyl-terminated polyester is a hydroxyl-terminated polyester with a molecular weight of 2000-2500 synthesized by reacting hydrogenated bisphenol A and 1,4-cyclohexanedicarboxylic acid at a molar ratio of 1: (0.8-0.85); (4) spraying a transition layer material; the transition layer material is obtained by mixing an isolation primer and an HDI dimer in a mass ratio of 10:1; (5) Spraying car cover film material; the car cover film material comprises component A and component B; the component A is composed of isocyanate and solvent, and the isocyanate is selected from any one or more of hydrogenated MDI, HDI dimer or HDI trimer; the component B is composed of polycaprolactone diol, polycaprolactone triol, solvent and catalyst stannous octoate; (6) Spraying protective layer materials; (7) Body post-processing; The spraying operation of step (3) is specifically as follows: when spraying, a 1.3 mm caliber pneumatic spray gun is used to first spray the isolation primer once by a mist spray method, and then the isolation primer is sprayed again by a medium wet spray method, so that the isolation primer layer thickness reaches 10 microns; The spraying operation of step (4) is specifically as follows: when spraying, a 1.5 mm caliber pneumatic spray gun is used to spray the transition layer once by wet spraying, so that the thickness of the transition layer reaches 20 microns; The spraying operation of step (5) is specifically as follows: when spraying, component A and component B are added into the material barrel of a two-component polyurethane sprayer in a mass ratio of 1:1, the material temperature is set to 95-105°C, and component A and component B collide and mix at the outlet of the spray gun and then are immediately sprayed onto the vehicle body.

2. The spray coating method for a car cover according to claim 1, characterized in that: After spraying the transition layer, the car cover film should be sprayed within 15 minutes to 24 hours.

3. The spraying construction method of a car cover according to claim 1, wherein the car cover film material optionally further includes a color paste raw material, and the color paste raw material does not contain any resin.

4. The spray coating method for a car cover according to claim 1, characterized in that: The car cover film material in step (5) should be sprayed 3-5 times to make the car cover film layer thickness reach 200-300 microns.

5. The spray coating method for a car cover according to claim 1, characterized in that: The protective layer material is made of fluorine-modified hydroxy acrylic resin and HDI trimer. The fluorine-modified hydroxy acrylic resin is obtained by free radical copolymerization of 2-5% perfluorohexylethyl acrylate, 18-22% hydroxyethyl methacrylate, 40-50% isobornyl methacrylate, 10-15% methyl methacrylate, and 15-20% isooctyl methacrylate in butyl acetate.

6. The spray coating method for a car cover according to claim 1, characterized in that: The spraying operation of step (6) is specifically as follows: using a 1.3 mm caliber pneumatic spray gun, wet spraying the protective layer material twice to make the protective layer thickness reach 60 microns.

7. The spray coating method for a vehicle cover according to any one of claims 1 to 6, characterized in that: The construction environment temperature of steps (3) to (6) is 25-35°C.

8. The spray coating method for a car cover according to claim 1, characterized in that: The vehicle body post-processing in step (7) is specifically as follows: after the protective layer is sprayed, the vehicle body is left to stand for 3 hours, and then the masking film is removed; after 24 hours, the surface is polished to treat the defective points.

9. A car cover prepared by the spraying construction method of any one of claims 1 to 8.

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