Melamine paper PVC film skin surface acrylic solid color mixed oil paint coating process

Abstract

The application discloses a melamine paper PVC film skin surface acrylic solid color mixed oil paint coating process and belongs to the PVC film skin coating technical field.The process takes acrylic paint as a base material, adds 1%-3% of a coupling agent as an adhesion promoting additive, adopts low-temperature construction and medium-low-temperature constant-temperature baking curing, and only needs single-pass colored topcoat spraying in the whole process, specifically includes four steps of substrate pretreatment, paint preparation, low-temperature topcoat spraying, medium-low-temperature baking drying and curing, and accurately limits core parameters such as construction temperature 18 DEG C, relative humidity 55%-65%, baking temperature 40 DEG C and baking duration 10 hours.The application significantly improves the adhesion between the paint film and the PVC substrate, realizes one-time forming, prevents plasticizer migration, has excellent paint film forming effect, simplifies the process, reduces energy consumption and cost, is suitable for various PVC film skin surface mixed oil solid color coating of whole-house customized furniture, PVC film pressure door plates and the like, and is suitable for industrialized batch production.

Description

Technical Field

[0001] This invention relates to the field of PVC film coating technology, and in particular to an acrylic solid color mixed paint coating process for melamine paper PVC film surfaces. It is applicable to the mixed oil solid color coating processing of various PVC film surfaces such as whole-house custom furniture, PVC membrane-pressed door panels, PVC-coated decorative panels, and home furnishings, and can be widely used in home decoration, building materials processing and other related industries. Background Technology

[0002] Currently, when applying solid color paint to PVC membrane surfaces, the industry mostly uses conventional multi-coat spraying processes, primarily employing ordinary acrylic paints, PU paints, and other conventional coatings. During application, drying methods typically involve either natural drying at room temperature or high-temperature baking. Furthermore, some processes lack specific adaptations for the characteristics of PVC membranes, such as low polarity, smooth surface, and the tendency to retain release agents. This results in a cumbersome and energy-intensive overall process, making it difficult to meet the demands of industrialized mass production.

[0003] The existing process of applying a mixed-oil solid color coating to the surface of PVC film has many defects, as follows: 1. PVC film has low surface polarity, a smooth surface, and is prone to leaving mold release agent residue. When ordinary acrylic paint is applied directly, the adhesion is extremely poor, and problems such as paint film peeling, flaking, and scratching are likely to occur, which cannot guarantee the durability of the coating. 2. Conventional processes require multiple coats of topcoat, which are cumbersome and time-consuming, severely impacting production efficiency and increasing labor and time costs. 3. High-temperature baking process can accelerate the precipitation of plasticizer inside PVC film, which can lead to softening, stickiness, bleeding, and mottling of the paint film, seriously affecting the stability and service life of the paint film; 4. Improper temperature control during construction can easily lead to defects such as whitening of the paint film, sagging, and incomplete drying, resulting in poor paint film formation and failing to meet the appearance requirements of high-end home decoration. 5. Existing processes do not optimize the adhesion between the paint film and the PVC substrate through additives, resulting in an inability to balance paint film adhesion, drying efficiency, and paint film stability, making it difficult to solve the industry's core pain points.

[0004] The existing PVC film coating process fails to achieve an integrated process of "one coat of colored topcoat forming, low-temperature construction + medium-low temperature baking and curing, and simultaneous improvement of substrate adhesion by coupling agent-modified acrylic paint". It cannot solve the industry problem of not being able to balance construction efficiency, paint film adhesion and prevention of plasticizer migration, thus restricting the application and promotion of PVC film in the field of high-end home decoration. Summary of the Invention

[0005] To address the aforementioned deficiencies in existing technologies, the present invention aims to provide a process for applying acrylic solid color mixed paint to the surface of melamine paper PVC film, specifically solving the following technical problems: 1. Addressing the characteristics of PVC film surface low polarity and easy residue of release agent, this product solves the problems of poor adhesion and easy peeling of ordinary acrylic paint coating, and significantly improves the bonding strength between the paint film and PVC substrate. 2. Simplify the painting process, enabling solid color mixed paint to be completed with just one coat of colored topcoat, reducing construction steps, significantly improving production efficiency, and adapting to industrialized mass production; 3. A combination of low-temperature construction and medium-low temperature baking is adopted to avoid the migration of plasticizers inside the PVC film caused by high temperature, thus eliminating problems such as paint film stickiness, bleeding, and softening. 4. Accurately control all parameters during construction and baking to ensure complete drying and a smooth finish of the paint film, avoiding defects such as whitening, sagging, and uneven drying. 5. By modifying acrylic paint with coupling agents, multiple layers of bridging primer are no longer required. A single topcoat can achieve excellent solid color coverage and coating effect, effectively reducing construction costs and paint waste.

[0006] To achieve the above technical objectives, the present invention adopts the following technical solution: A process for applying a solid-color acrylic paint to the surface of melamine paper PVC film uses acrylic paint as a base, adds a coupling agent as an adhesion promoter, employs low-temperature application, and cures by baking at a medium-low temperature. Only one coat of colored topcoat is applied throughout the entire process. The specific steps are as follows: (1) Substrate pretreatment: Take the PVC film substrate to be coated, use a lint-free cloth dipped in isopropyl alcohol to wipe the surface of the substrate to remove surface release agent, oil stains, dust and impurities. After wiping, let it stand for 5 minutes to allow the solvent to completely evaporate. (2) Paint preparation: use acrylic solid color paint as the main paint, add coupling agent and stir evenly. The amount of coupling agent added is 1%-3% of the total mass of acrylic solid color paint. After preparation, let stand for 3 minutes to defoam and set aside. (3) Low temperature topcoat spraying: Under the conditions of ambient temperature of 18℃ and relative humidity of 55%-65%, the prepared acrylic solid color mixed paint is sprayed evenly on the surface of the pretreated PVC film in one go using a spray gun, and the wet film thickness is controlled to be 30-40μm. (4) Medium and low temperature baking and curing: Place the sprayed PVC film substrate into a constant temperature drying equipment, set the baking temperature to 40℃, and bake at a constant temperature for 10 hours to make the paint film completely dry and cured, thus completing the coating.

[0007] Furthermore, the coupling agent is a silane coupling agent, and the optimal addition amount is 3% of the total mass of the acrylic solid color paint.

[0008] Furthermore, the construction environment temperature is precisely controlled at 18℃±1℃, the baking and curing temperature is precisely controlled at 40℃±1℃, and the baking and curing time is precisely controlled at 10 hours±0.5 hours.

[0009] Furthermore, the isopropanol is analytical grade, and the topcoat is applied in a single coat, eliminating the need for multiple coats and primer layering.

[0010] Furthermore, the process is applicable to the mixed-oil solid color coating processing of PVC film surfaces such as whole-house customized furniture, PVC membrane-pressed door panels, PVC-coated decorative panels, and home furnishings.

[0011] The beneficial effects of this invention are as follows: 1. Significantly improved adhesion: By adding a coupling agent to the acrylic solid color paint, the bonding performance of the low polarity surface of the PVC film is effectively improved, which significantly enhances the adhesion between the paint film and the substrate. The paint film achieves a level 1 in the cross-cut test, and there is no peeling or flaking in the 100-cross test. The adhesion far exceeds that of ordinary acrylic paint coating processes, effectively extending the service life after coating.

[0012] 2. Significantly improved construction efficiency: Eliminating the cumbersome process of multiple sprayings in existing technologies, only one coat of colored topcoat is needed to achieve a complete coverage and high-quality mixed oil effect, greatly simplifying the construction process, shortening the construction cycle, and effectively improving production efficiency by more than 30%, making it suitable for industrialized mass production needs.

[0013] 3. Eliminate plasticizer migration: The 40℃ low-temperature baking process effectively avoids the precipitation of plasticizer inside the PVC film caused by high temperature stimulation, so that the paint film does not become sticky, discolored, or soft even after long-term storage. The paint film has extremely strong stability and solves the core defects of the existing high-temperature baking process.

[0014] 4. Excellent paint film forming effect: The application of 18℃ low-temperature construction, combined with precise temperature and humidity control, ensures that the paint film does not whiten, run, or have orange peel during the drying process. The surface is smooth and flat with uniform solid color, which can meet the appearance requirements of high-end home mixed oil finishes and enhance the added value of the product.

[0015] 5. Energy-saving and lower cost process: Single-coat spraying reduces paint waste, medium and low temperature baking significantly reduces energy consumption, and there is no need for multiple layers of bridging primer and topcoat, which can effectively reduce coating production costs, combining economy and environmental protection. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of the overall process of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] A process for applying acrylic solid color mixed paint to the surface of melamine paper PVC film uses acrylic paint as the base material and adds a coupling agent as an adhesion promoter. It employs low-temperature application and medium-low temperature constant-temperature baking for curing. The entire process requires only one coat of colored topcoat. The specific steps are as follows: 1. Substrate Pretreatment Take the PVC film substrate to be coated, use a lint-free cloth dipped in isopropyl alcohol to wipe the surface of the substrate thoroughly and evenly to remove the release agent, oil, dust and other impurities from the PVC film surface; after wiping, let the substrate stand for 5 minutes to allow the isopropyl alcohol solvent on the surface to completely evaporate, and obtain the pretreated PVC film substrate.

[0020] 2. Paint mixing Acrylic solid color paint is used as the main paint. A special coupling agent is added to it and stirred evenly to fully integrate the coupling agent with the acrylic solid color paint. The amount of coupling agent added is 1%-3% of the total mass of the acrylic solid color paint. After mixing, the mixture is allowed to stand for 3 minutes for defoaming treatment to obtain a directly sprayable acrylic solid color mixed paint for later use.

[0021] 3. Low-temperature topcoat spraying Under construction conditions with an ambient temperature of 18℃ and a relative humidity of 55%-65%, the mixed acrylic solid color paint is sprayed evenly onto the pre-treated PVC film surface in one pass using a spray gun, achieving single-pass coating without the need for multiple coats. During the spraying process, the wet film thickness is controlled at 30-40μm to ensure complete coverage of the solid color, uniform paint film without missed areas or runs.

[0022] 4. Medium and low temperature baking, drying and curing After the PVC film substrate has been sprayed, place it stably into a constant temperature drying equipment, set the baking temperature to 40℃, and bake it at a constant temperature for 10 hours to allow the paint film to dry and cure completely. After removing it, the acrylic solid color mixed oil coating process on the entire PVC film surface is complete.

[0023] The core process parameters of this invention are as follows, and their precise definition is key to achieving the technical effects of this invention: 1. Ambient temperature during construction: 18℃ (±1℃); 2. Relative humidity of the construction environment: 55%-65%; 3. Paint system: acrylic solid color paint + coupling agent, wherein the amount of coupling agent added is 3% of the total mass of acrylic solid color paint (optimal addition amount); 4. Number of topcoat coats: Only 1 coat; 5. Single coat wet film thickness: 30-40μm; 6. Baking and curing temperature: 40℃ (±1℃); 7. Baking and curing time: 10 hours (±0.5 hours); 8. Solvent for PVC substrate pretreatment: isopropanol. Example 1

[0024] 1. PVC substrate pretreatment: Take a PVC membrane-pressed door panel substrate (specifications: 1220mm×2440mm×2mm), use a lint-free cloth dipped in isopropyl alcohol (analytical grade) to wipe the surface of the substrate thoroughly to remove surface release agent, oil stains and dust impurities. After wiping, let it stand for 5 minutes to allow the surface solvent to completely evaporate. 2. Paint preparation: Take 1000g of acrylic solid color topcoat as the main paint, add 30g of silane coupling agent (addition amount is 3%), stir with a stirrer at 300r / min for 5min, after stirring evenly, let stand for 3min to defoam, and obtain acrylic solid color mixed paint for later use. 3. Topcoat spraying: Under the conditions of ambient temperature of 18℃ and relative humidity of 60%, the prepared acrylic solid color mixed paint is sprayed evenly onto the surface of the pretreated PVC membrane door panel in one go using a spray gun. The wet film thickness is controlled at 35μm to ensure complete coverage of the solid color and uniform paint film without any missed spots. 4. Baking and curing: Place the PVC membrane door panel after spraying smoothly into a constant temperature drying equipment, set the baking temperature to 40℃, and bake at a constant temperature for 10 hours. After removing it, cool it to room temperature to complete the coating.

[0025] Performance test results: After coating using the process described in this embodiment, the adhesion of the paint film reached level 1 in the cross-cut test (according to GB / T 9286-1998 standard); after placing the coated substrate in a constant temperature environment of 40℃ for 72 hours, there was no plasticizer migration or re-sticking; the paint film surface was smooth without whitening or sagging, and the solid color coverage was complete, meeting the appearance requirements of high-end home decoration; after baking at 40℃ for 10 hours, the paint film was completely cured and there was no stickiness to the touch.

[0026] Comparative Example 1 (Standard process, no coupling agent added + multiple spraying) 1. PVC substrate pretreatment: Same as in Example 1; 2. Paint preparation: Take 1000g of ordinary acrylic solid color topcoat, without adding coupling agent, stir it evenly and set aside; 3. Topcoat spraying: Under normal temperature (25℃) and humidity conditions, spray the pre-treated PVC membrane door panel in two coats using a spray gun. Let it stand for 1 hour after each coat, and control the total wet film thickness to be 35μm. 4. Drying and curing: Use room temperature natural drying method, dry for 24 hours to complete the coating.

[0027] Performance test results: The paint film adhesion was substandard, with large-area peeling observed in the cross-cut adhesion test; after placing the coated substrate in a constant temperature environment of 40℃ for 24 hours, the paint film softened and became sticky again; the construction cycle was as long as 26 hours, resulting in low production efficiency; and the paint film had slight sagging, failing to meet the requirements for high-end finishes.

[0028] Comparative Example 2 (Conventional baking process, high-temperature baking) 1. PVC substrate pretreatment: Same as in Example 1; 2. Paint preparation: Same as in Example 1; 3. Topcoat spraying: Same as in Example 1; 4. Baking and curing: Place the PVC membrane door panel after spraying into a constant temperature drying equipment, set the baking temperature to 60℃, bake at a constant temperature for 5 hours, remove and cool to room temperature to complete the coating.

[0029] Performance test results: The paint film showed slight color bleeding, the PVC film edge showed slight wrinkling, and the plasticizer was clearly exuded; although the paint film adhesion reached level 1, the stability was poor, and it was prone to softening after long-term storage, which could not meet the requirements for long-term use.

[0030] Test methods The performance tests of this invention were all performed in accordance with the following standards and methods: 1. Adhesion test: The test shall be conducted in accordance with GB / T 9286-1998 "Cross-cut test of paint and varnish film". The cross-cut tester shall be used to cut the paint film surface into a grid, and the peeling of the paint film after cutting shall be observed to determine the adhesion level. 2. Plasticizer migration resistance test: Place the coated PVC film substrate in a constant temperature environment of 40℃ for 72 hours, and visually observe whether the paint film shows phenomena such as stickiness, bleeding, or softening to determine the plasticizer migration resistance performance. 3. Paint film appearance test: The visual method is used to observe whether the paint film surface is smooth and whether there are defects such as whitening, runs, orange peel, and missed spraying under natural light conditions to determine the paint film forming effect. 4. Drying performance test: After baking at 40℃ for 10 hours, the paint film is checked by touch to see if it is completely cured and not sticky, and the drying performance is judged.

[0031] In summary, this invention achieves integrated optimization of solid color coating for PVC film, as detailed below: 1. The first single-coat spraying process of acrylic paint + coupling agent is specifically adapted to the surface characteristics of PVC film, which is low polarity and easy to leave mold release agent residue. Through the adhesion promotion effect of the coupling agent, the bonding strength between the paint film and the substrate is greatly improved, which solves the industry pain point of poor adhesion of existing processes. 2. The exclusive process parameters of precise low-temperature construction at 18℃ + baking at medium-low temperature of 40℃ for 10 hours ensure the drying efficiency of the paint film and effectively avoid the migration of plasticizers in the PVC film caused by high temperature, thus balancing drying efficiency and paint film stability. 3. Achieve one-coat topcoat application for PVC film mixed with solid color paint, completely eliminating the cumbersome process of multiple spraying and multiple layers of primer in existing technologies, greatly improving production efficiency, reducing construction costs, and solving the industry's problem of being unable to simultaneously achieve construction efficiency, adhesion, and prevention of plasticizer migration.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coating process for acrylic solid color mixed paint on the surface of melamine paper PVC film, characterized in that: Using acrylic paint as a base, a coupling agent is added as an adhesion promoter. Low-temperature application and medium-low temperature constant-temperature baking curing are employed. Only one coat of colored topcoat is applied throughout the entire process. The specific steps are as follows: (1) Substrate pretreatment: Take the PVC film substrate to be coated, use a lint-free cloth dipped in isopropyl alcohol to wipe the surface of the substrate to remove surface release agent, oil stains, dust and impurities. After wiping, let it stand for 5 minutes to allow the solvent to completely evaporate. (2) Paint preparation: use acrylic solid color paint as the main paint, add coupling agent and stir evenly. The amount of coupling agent added is 1%-3% of the total mass of acrylic solid color paint. After preparation, let stand for 3 minutes to defoam and set aside. (3) Low temperature topcoat spraying: Under the conditions of ambient temperature of 18℃ and relative humidity of 55%-65%, the prepared acrylic solid color mixed paint is sprayed evenly on the surface of the pretreated PVC film in one go using a spray gun, and the wet film thickness is controlled to be 30-40μm. (4) Medium and low temperature baking and curing: Place the sprayed PVC film substrate into a constant temperature drying equipment, set the baking temperature to 40℃, and bake at a constant temperature for 10 hours to make the paint film completely dry and cured, thus completing the coating.

2. The acrylic solid color mixed paint coating process for melamine paper PVC film surface according to claim 1, characterized in that, The coupling agent is a silane coupling agent, and the optimal addition amount is 3% of the total mass of the acrylic solid color paint.

3. The acrylic solid color mixed paint coating process for melamine paper PVC film surface according to claim 1, characterized in that, The construction environment temperature is precisely controlled at 18℃±1℃, the baking and curing temperature is precisely controlled at 40℃±1℃, and the baking and curing time is precisely controlled at 10 hours±0.5 hours.

4. The acrylic solid color mixed paint coating process for melamine paper PVC film surface according to claim 1, characterized in that, The isopropanol is of analytical grade, and the topcoat is applied in a single coat, eliminating the need for multiple coats and primer layering.

5. The acrylic solid color mixed paint coating process for melamine paper PVC film surface according to claim 1, characterized in that, The process described is applicable to the mixed-oil solid color coating of PVC film surfaces such as whole-house custom furniture, PVC membrane-pressed door panels, PVC-coated decorative panels, and home furnishings.

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