Plastic part surface spraying process
By adding UV absorbers and phthalocyanine blue to the primer and topcoat of plastic parts, the fading problem of the dye layer during UV curing is solved, and the color stability and high-end decorative effect of the plastic parts are achieved.
Patent Information
- Application Number
- CN202510974110.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-15
- Publication Date
- 2025-10-17
Smart Images
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of plastic part decoration, in particular to a plastic part surface spraying process. BACKGROUND
[0002] In the production process of plastic products, in order to meet the diversified appearance requirements, the plastic parts will usually be colored before molding. Although this pre-coloring method can give the plastic parts the required color to some extent, it has limitations and cannot achieve complex color effects and high-end decoration requirements. Therefore, in many cases, subsequent surface treatment such as paint spraying and UV curing treatment is still needed for the plastic parts to further improve their appearance quality and decoration performance.
[0003] However, for plastic parts that have completed dyeing treatment, the ultraviolet radiation and heat generated during UV curing treatment will have photochemical and thermochemical effects on the dyeing layer. These effects will cause the dye molecules to decompose or denature, resulting in fading of the dyeing color. This fading phenomenon not only affects the appearance consistency of the product and reduces the decoration effect, but also may weaken the market competitiveness of the product. SUMMARY
[0004] In order to solve the fading problem of plastic parts during subsequent treatment such as UV curing in the prior art, the present application discloses a plastic part surface spraying process, which effectively prevents the colored plastic parts from discoloring or fading during UV curing treatment by adding ultraviolet absorbers and phthalocyanine blue in the components of the primer and topcoat, so that the original dyeing color can be maintained, thereby solving the fading problem of plastic parts during subsequent treatment such as UV curing in the prior art.
[0005] The technical solution adopted by the present application to solve its technical problems is: A plastic part surface spraying process, comprising the following steps: S01: cleaning the already dyed and molded plastic parts; S02: electrostatic treatment of the above-mentioned plastic parts, followed by primer spraying and UV curing; S03: placing the plastic parts into the vacuum coating cavity of the optical coating machine for vacuum optical coating; S04: electrostatic dust removal of the above-mentioned plastic parts, followed by topcoat spraying, UV curing, final inspection and packaging.
[0006] Optionally, the primer comprises the following components by weight: 13-15 parts of trifunctional reactive monomer; 5-6 parts of polyurethane acrylate oligomer; epoxy acrylate oligomer 11-15 parts; ultraviolet absorber 0.1-1.5 parts; phthalocyanine blue 0.1-0.2 parts; photoinitiator 3-4 parts; leveling agent 0.1-0.2 parts; organic solvent 50-60 parts; antioxidant 0.1-0.5 parts; polymerization inhibitor 0.1-0.5 parts.
[0007] Optionally, the ultraviolet absorber is selected from at least one of benzotriazole, benzophenone, hydroxyphenyl triazine.
[0008] Optionally, the organic solvent is selected from at least one of ethyl acetate, butyl acetate, methyl isobutyl ketone, propylene glycol methyl ether acetate.
[0009] Optionally, the trifunctional reactive monomer is selected from at least one of trimethylolpropane triacrylate, pentaerythritol triacrylate.
[0010] Optionally, the epoxy acrylate oligomer is selected from at least one of epoxy acrylate, modified epoxy acrylate.
[0011] Optionally, the polyurethane acrylate oligomer is selected from at least one of aliphatic polyurethane acrylate, aliphatic polyurethane hexaacrylate.
[0012] Optionally, the UV curing is performed by baking the sprayed plastic part for 3-5 minutes, and then irradiating with a UV mercury lamp for 20-40 seconds, with a UV energy of 300-600 mJ; the primer and the topcoat are each sprayed to a thickness of 15-20 μm.
[0013] Optionally, the step S03 comprises the following specific step: placing the plastic part into a vacuum coating cavity of an optical coating machine or a vertical coating machine, and performing vacuum optical coating treatment, wherein the coating material is zinc sulfide and silicon monoxide, and the coating time is 10-20 minutes.
[0014] Optionally, the topcoat comprises the following components in parts by weight: trifunctional reactive monomer 6-8 parts; polyurethane acrylate oligomer 5-6 parts; epoxy acrylate oligomer 10-12 parts; hydroxyethyl methacrylate 6-8 parts; special functional group acrylate oligomer 3-5 parts; ultraviolet absorber 0.1-1.5 parts; Phthalo blue 0.1-0.2 parts; Photoinitiator 3-4 parts; Leveling agent 0.1-0.2 parts; Organic solvent 50-60 parts; Antioxidant 0.1-0.5 parts; Polymerization inhibitor 0.1-0.5 parts.
[0015] The present application has the following beneficial effects: The surface spraying process for plastic parts provided by the present application effectively solves the discoloration problem of the plastic parts after dyeing treatment in the subsequent UV curing process by adding ultraviolet absorbers and phthalo blue in the primer and topcoat components. The ultraviolet absorbers can absorb and shield ultraviolet radiation, reducing the risk of dye decomposition or denaturation of the plastic dyeing layer due to photochemical and thermal chemical effects; as a blue pigment, phthalo blue not only further enhances the color stability of the coating, but also synergistically acts with the ultraviolet absorbers and various components to ensure that the dyed plastic parts still maintain the original bright and stable color after UV curing, thereby significantly improving the color stability and appearance quality of the plastic parts, meeting the high-end decoration requirements. DETAILED DESCRIPTION
[0016] The present application will now be further described in detail. The examples described below are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application. Based on the examples of the present application, all other examples obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.
[0017] To solve the discoloration problem of the plastic parts in the subsequent treatment such as UV curing in the prior art, the present application provides a surface spraying process for plastic parts, comprising the following steps: A surface spraying process for plastic parts, comprising the following steps: S01: cleaning the already dyed and shaped plastic parts; S02: electrostatic treatment of the above-mentioned plastic parts, then primer spraying, and then UV curing; S03: placing the plastic parts into the vacuum coating cavity of the optical coating machine, and then performing vacuum optical coating; S04: electrostatic dust removal of the above-mentioned plastic parts, then topcoat spraying, UV curing, and finally inspection and packaging. Specifically, the primer of the present application preferably comprises the following components according to weight fraction: Trifunctional reactive monomer 13-15 parts; Polyurethane acrylate oligomer 5-6 parts; Epoxy acrylate oligomer 11-15 parts; UV absorber 0.1-1.5 parts; Phthalocyanine blue 0.1-0.2 parts; Photoinitiator 3-4 parts; Leveling agent 0.1-0.2 parts; Organic solvent 50-60 parts; Antioxidant 0.1-0.5 parts; Polymerization inhibitor 0.1-0.5 parts.
[0018] The preferred UV curing method of the present application is as follows: the sprayed plastic part is baked for 3-5 minutes, then irradiated by a UV mercury lamp for 20-40 seconds, and the UV energy is 300-600 mJ; the thickness of the primer and topcoat is 15-20 μm.
[0019] The preferred topcoat of the present application comprises the following components by weight: Trifunctional reactive monomer 6-8 parts; Polyurethane acrylate oligomer 5-6 parts; Epoxy acrylate oligomer 10-12 parts; Hydroxyethyl methacrylate 6-8 parts; Special functional group acrylate oligomer 3-5 parts; UV absorber 0.1-1.5 parts; Phthalocyanine blue 0.1-0.2 parts; Photoinitiator 3-4 parts; Leveling agent 0.1-0.2 parts; Organic solvent 50-60 parts; Antioxidant 0.1-0.5 parts; Polymerization inhibitor 0.1-0.5 parts.
[0020] The specific step S03 of the present application is as follows: the plastic part is placed into the vacuum coating cavity of an optical coating machine or a vertical coating machine, and vacuum optical coating treatment is performed, wherein the coating material is zinc sulfide and silicon monoxide, and the coating time is 10-20 minutes.
[0021] Generally, when the coating material is zinc sulfide and silicon monoxide, the coating layer is usually an optically transparent or translucent film layer, which has a high transmittance to UV light. Therefore, during the UV curing process, the dyeing layer on the surface of the plastic part is more easily affected by the radiation of UV light, and the dye molecules are easily photodegraded or discolored by UV irradiation. Therefore, it is necessary to add a UV absorber to the primer and topcoat to significantly reduce the radiation of UV light on the dyeing layer. At the same time, phthalocyanine blue is added as a blue pigment for stability, which can better compensate for the color change that may occur under the action of UV light and maintain the stability of the color.
[0022] When the coating material is aluminum, the aluminum film is a highly reflective metal film layer, which has high reflectivity to ultraviolet light and visible light. At this time, it is difficult for ultraviolet light to penetrate the aluminum film layer to act on the dyeing layer on the plastic surface, so the possibility of the dyeing layer being affected by ultraviolet light is greatly reduced. Based on this situation, there is no need to specially add ultraviolet absorbers and phthalocyanine blue in the primer and topcoat to meet the requirements for color stability, thereby simplifying the process and reducing costs.
[0023] In the present application, the preferred ultraviolet absorber is selected from at least one of benzotriazole, benzophenone, and hydroxyphenyl triazine.
[0024] In the present application, the preferred organic solvent is selected from at least one of ethyl acetate, butyl acetate, methyl isobutyl ketone, and propylene glycol methyl ether acetate.
[0025] In the present application, the preferred trifunctional reactive monomer is selected from at least one of trimethylolpropane triacrylate and pentaerythritol triacrylate; further, the preferred trifunctional reactive monomer is trimethylolpropane triacrylate; and specifically, the preferred type of trimethylolpropane triacrylate is at least one of Changxing EM231 and Sanmee SM631.
[0026] In the present application, the preferred epoxy acrylate oligomer is selected from at least one of epoxy acrylate and modified epoxy acrylate; further, the preferred type of epoxy acrylate is at least one of Changxing 621A-80, Sanmee 6104, and Sanmee 6105; and specifically, the preferred type of modified epoxy acrylate is at least one of Changxing 6215-100 and Sanmee 6100d.
[0027] In the present application, the preferred polyurethane acrylate oligomer is selected from at least one of aliphatic polyurethane acrylate and aliphatic polyurethane hexaacrylate; further, the preferred type of aliphatic polyurethane acrylate is at least one of Changxing 6112-100 and Sanmee 6240; and specifically, the preferred type of aliphatic polyurethane hexaacrylate is at least one of Changxing 6145-100 and Sanmee 6621.
[0028] In the present application, the preferred special functional group acrylate oligomer is a solvent type modified acrylate; further, the preferred type of solvent type modified acrylate is at least one of Changxing 6071, Changxing 6063, and Changxing 6077.
[0029] In the present application, the addition of the ultraviolet absorber and phthalocyanine blue in the topcoat component can be flexibly adjusted according to actual conditions. If the plastic part can maintain stable color and no obvious discoloration after UV curing after adding only in the primer, the above components can not be added in the topcoat; if there is still slight discoloration after curing after adding in the primer, a proper amount of ultraviolet absorber and phthalocyanine blue can be added in the topcoat to further enhance the color stability, so as to fully realize the technical effect of the present application.
[0030] In addition, it is worth noting that the topcoat component of the present application also contains a special functional group acrylate oligomer. When it is necessary to add ultraviolet absorber and phthalocyanine blue in the topcoat, the amount of special functional group acrylate oligomer should be appropriately reduced. This is because although the special functional group acrylate oligomer can significantly improve the weather resistance, scratch resistance and adhesion of the topcoat coating, it may interact or compete with the ultraviolet absorber and phthalocyanine blue, weakening the effective absorption of the latter to ultraviolet and the stability of color. Therefore, by appropriately reducing the addition amount of special functional group acrylate oligomer, the adverse mutual interference between components can be avoided, ensuring that the ultraviolet absorber and phthalocyanine blue can play a more effective role, and further improving the color stability and comprehensive performance of the topcoat coating.
[0031] The preferred photoinitiator of the present application is selected from at least one of 1-hydroxycyclohexyl phenyl ketone, diphenyl-(2,4,6-trimethylbenzoyl) phosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1-propanone.
[0032] The preferred leveling agent of the present application is selected from at least one of BYK306, BYK333.
[0033] The preferred antioxidant of the present application is selected from at least one of antioxidant 1030, antioxidant 1076, antioxidant 1098.
[0034] The preferred polymerization inhibitor of the present application is selected from at least one of hydroquinone, p-hydroxyanisole, 2-tert-butyl hydroquinone.
[0035] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below.
[0036] Without special instructions, the leveling agent in each embodiment of the present application is BYK306; the polymerization inhibitor is hydroquinone; the photoinitiator is 1-hydroxycyclohexyl phenyl ketone; the antioxidant is antioxidant 1030; the solvent type modified acrylate is Changxing 6071; the amount of materials in each embodiment and the comparative example is calculated by weight fraction, and the surface spraying process of the plastic part in each embodiment of the present application includes the following steps: S01: cleaning treatment of the plastic part which has been dyed and formed; S02: After the electrostatic treatment of the plastic part, primer spraying is performed, the sprayed plastic part is baked for 3-5 minutes, and then irradiated with a UV mercury lamp for 20-40 seconds, the UV energy is 300-600 mJ; and the thickness of the primer spraying is 15-20 μm; S03: The plastic part is placed into the vacuum coating cavity of the optical coating machine or the vertical coating machine, and vacuum optical coating treatment is performed, wherein the coating material is zinc sulfide and silicon monoxide, and the coating time is 10-20 minutes; S04: After the electrostatic dust removal of the plastic part, topcoat spraying is performed, the sprayed plastic part is baked for 3-5 minutes, and then irradiated with a UV mercury lamp for 20-40 seconds, the UV energy is 300-600 mJ; and the thickness of the topcoat spraying is 15-20 μm; finally, inspection and packaging are performed.
[0037] Table 1 is the component ratio of the primer, and Table 2 is the component ratio of the topcoat, and the spraying process of the surface of the plastic part of each example is completed according to the above preparation method.
[0038] Comparative Example 1 This comparative example is the same as Example 1, except that no ultraviolet absorber is added to the primer of Comparative Example 1.
[0039] Comparative Example 2 This comparative example is the same as Example 1, except that no phthalocyanine blue is added to the primer of Comparative Example 2.
[0040] Comparative Example 3 This comparative example is the same as Example 1, except that the amount of the special functional group acrylate oligomer in Comparative Example 3 is 10 parts.
[0041] Comparative Example 4 This comparative example is the same as Example 1, except that the phthalocyanine blue in the primer of Example 1 is replaced with an anthraquinone dye (blue).
[0042] Comparative Example 5 This comparative example is the same as Example 1, except that the thickness of the primer spraying in Comparative Example 5 is 10 μm.
[0043] Comparative Example 6 This comparative example is the same as Example 1, except that the UV energy in the UV curing process of Comparative Example 6 is 800 mJ.
[0044] Table 3 is the performance parameters of the plastic parts prepared in each example and comparative example of the present application, and the following performance parameters are measured by visual method.
[0045] It can be seen from the above data that, by the plastic part surface spraying process provided by the application, by adding ultraviolet absorber and phthalocyanine blue in the primer component and the synergistic effect between the components, the plastic parts after dyeing treatment in each embodiment of the application will not discolor or fade during the UV curing process, can maintain the original dyeing color, significantly improve the color stability and appearance quality of the plastic parts.
[0046] Based on the above ideal embodiments according to the application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the application. The technical scope of the application is not limited to the content in the specification, and the technical scope must be determined according to the scope of claims.
Claims
1. A plastic part surface spraying process, characterized in that: The following steps are involved: S01: Cleaning of dyed and molded plastic parts; S02: spraying primer on the plastic parts after electrostatic treatment, and then UV curing; S03: The plastic part is then placed into the vacuum coating chamber of the optical coating machine for vacuum optical coating; S04: After electrostatic dust removal, the above plastic parts are sprayed with topcoat, UV cured, and finally inspected and packaged.
2. The plastic part surface spraying process according to claim 1, characterized in that: The primer comprises the following components in parts by weight: 13-15 parts of trifunctional reactive monomer; 5-6 parts of polyurethane acrylate oligomer; 11-15 parts of epoxy acrylate oligomer; 0.1-1.5 parts of ultraviolet absorber; Phthalocyanine blue 0.1-0.2 parts; 3-4 parts of photoinitiator; 0.1-0.2 parts of leveling agent; 50-60 parts of organic solvent; 0.1-0.5 parts of antioxidant; 0.1 to 0.5 parts of polymerization inhibitor.
3. The plastic part surface spraying process according to claim 2, characterized in that: The ultraviolet absorber is selected from at least one of benzotriazole, benzophenone and hydroxyphenyltriazine.
4. The plastic part surface spraying process according to claim 2, characterized in that: The organic solvent is selected from at least one of ethyl acetate, butyl acetate, methyl isobutyl ketone, and propylene glycol methyl ether acetate.
5. The plastic part surface spraying process according to claim 2, characterized in that: The trifunctional reactive monomer is selected from at least one of trimethylolpropane triacrylate and pentaerythritol triacrylate.
6. The plastic part surface spraying process according to claim 2, characterized in that: The epoxy acrylate oligomer is selected from at least one of epoxy acrylate and modified epoxy acrylate.
7. The plastic part surface spraying process according to claim 2, characterized in that: The polyurethane acrylate oligomer is selected from at least one of aliphatic polyurethane acrylate and aliphatic polyurethane hexaacrylate.
8. The plastic part surface spraying process according to claim 1, characterized in that: The UV curing method is: baking the sprayed plastic part for 3 to 5 minutes, and then irradiating it with a UV mercury lamp for 20 to 40 seconds, with UV energy of 300 to 600 millijoules; the thickness of the primer and topcoat sprayed is 15 to 20 μm.
9. The plastic part surface spraying process according to claim 1, characterized in that: The specific steps of step S03 are: placing the plastic part into the vacuum coating chamber of an optical coating machine or a vertical coating machine, and performing vacuum optical coating treatment, wherein the coating material is zinc sulfide and silicon monoxide, and the coating time is 10 to 20 minutes.
10. The plastic part surface spraying process according to claim 1, characterized in that: The topcoat comprises the following components in parts by weight: 6-8 parts of trifunctional reactive monomer; 5-6 parts of polyurethane acrylate oligomer; 10-12 parts of epoxy acrylate oligomer; 6-8 parts of hydroxyethyl methacrylate; 3-5 parts of special functional group acrylate oligomer; 0.1-1.5 parts of ultraviolet absorber; Phthalocyanine blue 0.1-0.2 parts; 3-4 parts of photoinitiator; 0.1-0.2 parts of leveling agent; 50-60 parts of organic solvent; 0.1-0.5 parts of antioxidant; 0.1 to 0.5 parts of polymerization inhibitor.