Peelable coating and color-coated sheet preparation process based on peelable coating

Abstract

The invention belongs to the technical field of color-coated sheet protection layer manufacturing, and relates to a strippable coating and a color-coated sheet preparation process based on the strippable coating. The strippable coating is prepared from the following components in parts by mass: hydroxyl-terminated hydrogenated polybutadiene, 4, 4-dicycloethyl methane diisocyanate, hydroxyethyl acrylate, pentaerythritol triacrylate, an initiator and a reactive diluent. The preparation process of the color-coated sheet based on the strippable coating comprises the following steps: step 1, uncoiling the metal base material, step 2, coating the strippable coating, and step 3, curing the coating. The problem that the color-coated sheet with a damaged protective layer is inconvenient for a worker to reutilize due to the fact that the protective layer of the existing color-coated sheet is too high in adhesiveness is effectively solved. By optimizing the coating preparation process of the color-coated sheet, the strippable protective layer is coated on the color-coated sheet through a roller coating process, the novel color-coated sheet with the strippable protective layer is prepared, and the production process and the use process of the protective layer of the traditional color-coated sheet are broken through.

Description

Technical Field

[0001] The invention relates to the technical field of color-coated plate protective layer manufacturing, and in particular to a strippable coating and a color-coated plate preparation process based on the strippable coating. Background Art

[0002] In the process of color-coated plates production, in order to make the color-coated plates have better corrosion resistance and wear resistance, it is often necessary to cover the surface of the color-coated plates with a protective layer. The existing protective layer has high adhesion after being covered on the surface of the color-coated plates. However, the high adhesion causes the protective layer to be damaged and when the original protective layer needs to be peeled off, the remaining protective layer is not easy to peel off from the color-coated plates. Therefore, the color-coated plates with residual protective layers can only be scrapped and cannot be reused. Summary of the invention

[0003] In view of the above situation, in order to overcome the defects of the prior art, the purpose of the present invention is to provide a peelable coating and a preparation process for applying the peelable coating to the color-coated plate, which effectively solves the problem that the adhesion of the protective layer of the existing color-coated plate is too high, making it inconvenient for the staff to reuse the color-coated plate with damaged protective layer.

[0004] The technical solution to the problem of the present invention is a strippable coating, which is composed of the following components by mass: 8-10 parts of terminal hydroxyl hydrogenated polybutadiene, 6-12 parts of 4,4-dicycloethylmethane diisocyanate, 2 parts of hydroxyethyl acrylate, 10-11 parts of pentaerythritol triacrylate, 3-4 parts of initiator and 3-4 parts of active diluent.

[0005] Preferably, the initiator is lauroyl peroxide, tert-butyl hydroperoxide or dicyclohexyl peroxydicarbonate.

[0006] Preferably, the reactive diluent is β-hydroxyethyl methacrylate, 1,6-hexanediol diacrylate or alkylene glycidyl ether.

[0007] A process for preparing a color-coated plate based on the strippable coating according to claim 1, comprising the following steps:

[0008] Step 1, coating preparation: prepare polyurethane acrylate in the order of ① terminal hydroxyl hydrogenated polybutadiene, ② 4,4-dicycloethylmethane diisocyanate, ③ hydroxyethyl acrylate, and ④ pentaerythritol triacrylate, add initiator and active diluent to polyurethane acrylate in sequence, stir at 1200r / min for 60s at room temperature to obtain a strippable coating.

[0009] Step 2, unwinding the metal substrate: using alkaline solution to clean the surface of the metal substrate to remove oil stains to obtain a clean metal substrate after unwinding;

[0010] Step 3, coating: coating the strippable coating on the clean metal substrate surface obtained in step 2 by using a roller coating device;

[0011] Step 4: Coating curing: Use a light curing device to irradiate the clean metal substrate surface coated with the strippable coating in step 3 to obtain a color-coated plate with a strippable coating.

[0012] Preferably, the alkali solution components in step 2 are 1-2 parts by mass of sodium hydroxide, 1-2 parts by mass of sodium silicate, 1-3 parts by mass of disodium phosphate and 1-2 parts by mass of sodium carbonate.

[0013] Preferably, the roller coating equipment in step three is a horizontal roller coater.

[0014] Preferably, the light curing equipment in step 4 is a crawler light curing machine, and the curing exposure time in step 4 is 60 seconds.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] The present invention optimizes the coating preparation process of the color-coated plate, and directly coats the peelable protective layer on the color-coated plate through a roller coating process to produce a new type of color-coated plate with a peelable protective layer, breaking the traditional production process and use process of the protective layer of the color-coated plate and improving the market value of the product; the present invention optimizes the formula of the peelable coating so that the protective layer coated on the color-coated plate can ensure the high strength of the color-coated plate while having good peeling performance; the present invention uses a preparation process to ensure that the protective layer can be peeled off from the surface of objects such as the color-coated plate and the device after the protective function is completed, and no substances that affect the base material of the color-coated plate, the use performance of the device, etc. will remain. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by relevant technicians in the field without creative work are within the scope of protection of the present invention.

[0018] Embodiment 1

[0019] Step 1, coating preparation, based on a metal substrate with a width of 0.5 meters, add 8-10 parts of terminal hydroxyl hydrogenated polybutadiene, 8-10 parts of 4,4-dicycloethylmethane diisocyanate, 2 parts of hydroxyethyl acrylate, 10-11 parts of pentaerythritol triacrylate, 3-4 parts of initiator and 3-4 parts of active diluent in sequence, and stir in a reactor at room temperature at 1200r / min for 60s or use other mixing methods to a viscosity of 466-556 centistokes (mm2 / s), specific gravity 1.00-1.20g / ml and other appropriate conditions to obtain a strippable coating;

[0020] Step 2, unwinding the metal substrate, and evenly applying an alkali solution composed of sodium hydroxide, sodium silicate, disodium phosphate, sodium carbonate, and having a pH value of 8.0 on the surface of the metal substrate to remove the oil stains attached to the surface of the metal substrate, thereby obtaining a clean metal substrate surface;

[0021] Step 3: coating, using a horizontal roller coating device to coat the strippable coating on the surface of the clean metal substrate obtained in step 2, ensuring that the coating thickness is 0.03 mm to 0.045 mm, to obtain a metal substrate covered with the coating;

[0022] Step 4: Curing the coating: The metal substrate covered with the coating obtained in step 3 is passed through a crawler light curing machine and exposed for 60 seconds to obtain a color-coated plate covered with a strippable coating.

[0023] The prepared color-coated plates were treated at room temperature to simulate the consumption of the protective layer of the color-coated plates under actual conditions. When the protective layer of the color-coated plates was consumed to a point that it was insufficient to protect the color-coated plates, the color-coated plates were taken out for surface protective layer scraping. An unwinding machine was used to reciprocate mechanically scrape the surface of the color-coated plates at a force of approximately 2.7 N / cm (it can be directly peeled off with manual assistance). After 1 minute, the surface protective layer of the color-coated plates was completely scraped off, and no damage was caused to the surface of the color-coated plate substrate.

[0024] Embodiment 2

[0025] Step 1: Preparation of coating: Based on a metal substrate with a width of 0.5 m, add 6-7 parts of hydroxyl-terminated hydrogenated polybutadiene, 6-8 parts of 4,4-dicycloethylmethane diisocyanate, 2 parts of hydroxyethyl acrylate, 10-11 parts of pentaerythritol triacrylate, 3-4 parts of initiator and 3-4 parts of active diluent in sequence, and stir in a reactor at room temperature at 1200 r / min for 60 s or use other mixing methods until the viscosity reaches 466-556 centistokes (mm 2 / s), specific gravity 1.00-1.20g / ml and other appropriate conditions to obtain a strippable coating;

[0026] Step 2, unwinding the metal substrate, and evenly applying an alkali solution composed of sodium hydroxide, sodium silicate, disodium phosphate, sodium carbonate, and having a pH value of 8.0 on the surface of the metal substrate to remove the oil stains attached to the surface of the metal substrate, thereby obtaining a clean metal substrate surface;

[0027] Step 3: coating, using a horizontal roller coating device to coat the strippable coating on the surface of the clean metal substrate obtained in step 2, ensuring that the coating thickness is 0.03 mm to 0.045 mm, to obtain a metal substrate covered with the coating;

[0028] Step 4: Curing the coating: The metal substrate covered with the coating obtained in step 3 is passed through a crawler light curing machine and exposed for 60 seconds to obtain a color-coated plate covered with a strippable coating.

[0029] The prepared color-coated plates were treated at room temperature to simulate the consumption of the protective layer of the color-coated plates under actual conditions. When the protective layer of the color-coated plates was consumed to the point where it was insufficient to protect the color-coated plates, the color-coated plates were taken out for surface protective layer scraping. An unwinding machine was used to reciprocate mechanically scrape the surface of the color-coated plates at a force of approximately 2.7 N / cm (it can be directly peeled off with manual assistance). After 1 minute, a small amount of residue remained on the surface protective layer of the color-coated plates, and no damage was caused to the surface of the color-coated plate substrate.

[0030] Embodiment 3

[0031] Step 1: Preparation of coating: Based on a metal substrate with a width of 0.5 m, add 11-13 parts of hydroxyl-terminated hydrogenated polybutadiene, 10-12 parts of 4,4-dicycloethylmethane diisocyanate, 2 parts of hydroxyethyl acrylate, 10-11 parts of pentaerythritol triacrylate, 3-4 parts of initiator and 3-4 parts of active diluent in sequence, and stir in a reactor at room temperature at 1200 r / min for 60 s or use other mixing methods until the viscosity reaches 466-556 centistokes (mm 2 / s), specific gravity 1.00-1.20g / ml and other appropriate conditions to obtain a strippable coating;

[0032] Step 2, unwinding the metal substrate, and evenly applying an alkali solution composed of sodium hydroxide, sodium silicate, disodium phosphate, sodium carbonate, and having a pH value of 8.0 on the surface of the metal substrate to remove the oil stains attached to the surface of the metal substrate, thereby obtaining a clean metal substrate surface;

[0033] Step 3: coating, using a horizontal roller coating device to coat the strippable coating on the surface of the clean metal substrate obtained in step 2, ensuring that the coating thickness is 0.03 mm to 0.045 mm, to obtain a metal substrate covered with the coating;

[0034] Step 4: Curing the coating: The metal substrate covered with the coating obtained in step 3 is passed through a crawler light curing machine and exposed for 60 seconds to obtain a color-coated plate covered with a strippable coating.

[0035] The prepared color-coated plates were treated at room temperature to simulate the consumption of the protective layer of the color-coated plates under actual conditions. When the protective layer of the color-coated plates was consumed to the point where it was insufficient to protect the color-coated plates, the color-coated plates were taken out for surface protective layer scraping. An unwinding machine was used to reciprocate mechanically scrape the surface of the color-coated plates at a force of approximately 2.7 N / cm (it can be directly peeled off with manual assistance). After 1 minute, a small amount of residue remained on the surface protective layer of the color-coated plates, and no damage was caused to the surface of the color-coated plate substrate.

[0036] Comparative ratio,

[0037] The traditional surface protective film of color-coated plates is mainly made of polyethylene (PE), PET (polyester), CPP (polypropylene), PVC (polyvinyl chloride), and OPP. On this basis, the PE / PET / CPP / PVC and other protective layers are directly covered on the surface of the color-coated plates through the film roller equipment.

[0038] When the protective layer of the color-coated plate is consumed to the point where it is insufficient to protect the color-coated plate, the color-coated plate is taken out for scraping off the surface protective layer. The surface of the color-coated plate is scraped off manually with the assistance of an unwinder. The surface protective layer of the color-coated plate is completely scraped off, which can easily cause residual glue, marks, scratches, etc. on the surface of the color-coated plate.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A peelable coating, characterized in that: The invention is composed of the following components by mass: 8-10 parts of terminal hydroxyl hydrogenated polybutadiene, 6-12 parts of 4,4-dicycloethylmethane diisocyanate, 2 parts of hydroxyethyl acrylate, 10-11 parts of pentaerythritol triacrylate, 3-4 parts of initiator and 3-4 parts of active diluent.

2. A strippable coating according to claim 1, characterized in that: The initiator is lauroyl peroxide, tert-butyl hydroperoxide or dicyclohexyl peroxydicarbonate.

3. A strippable coating according to claim 1, characterized in that: The active diluent is β-hydroxyethyl methacrylate, 1,6-hexanediol diacrylate or alkylene glycidyl ether.

4. A process for preparing a color-coated plate based on the strippable coating according to claim 1, characterized in that: The following steps are included Step 1, coating preparation: prepare polyurethane acrylate in the order of ① terminal hydroxyl hydrogenated polybutadiene, ② 4,4-dicycloethylmethane diisocyanate, ③ hydroxyethyl acrylate, and ④ pentaerythritol triacrylate, add initiator and active diluent to polyurethane acrylate in sequence, stir at 1200r / min for 60s at room temperature to obtain a strippable coating. Step 2, unwinding the metal substrate: using alkaline solution to clean the surface of the metal substrate to remove oil stains to obtain a clean metal substrate after unwinding; Step 3, coating: coating the strippable coating on the clean metal substrate surface obtained in step 2 by using a roller coating device; Step 4: Coating curing: Use a light curing device to irradiate the clean metal substrate surface coated with the strippable coating in step 3 to obtain a color-coated plate with the strippable coating.

5. A process for preparing a color-coated plate based on a strippable coating according to claim 4, characterized in that: The components of the alkali solution in step 2 are 1-2 parts of sodium hydroxide, 1-2 parts of sodium silicate, 1-3 parts of disodium phosphate and 1-2 parts of sodium carbonate by mass.

6. A process for preparing a color-coated plate based on a strippable coating according to claim 4, characterized in that: The roller coating equipment in step 3 is a horizontal roller coater.

7. A process for preparing a color-coated plate based on a strippable coating according to claim 4, characterized in that: The light curing equipment in step 4 is a crawler light curing machine, and the curing exposure time in step 4 is 60 seconds.