UV (ultraviolet) jet printing pretreatment coating for PVC (polyvinyl chloride) edge band as well as preparation method and application of UV jet printing pretreatment coating

Abstract

The invention discloses a UV (ultraviolet) jet printing pretreatment coating for a PVC (polyvinyl chloride) edge band as well as a preparation method and application of the UV jet printing pretreatment coating, and the UV jet printing pretreatment coating comprises the following components in percentage by weight: 5-15% of hydroxyethyl methylacrylate, 5-10% of 1, 6-hexanediol diacrylate, 4-8% of an acylphosphine oxide photoinitiator, 3-8% of octyl acrylate and 30-40% of a polyurethane acrylate oligomer. The UV adhesive force auxiliary resin is prepared from the following components in percentage by weight: 1 to 4 percent of phosphoric acid modified methacrylate, 30 to 40 percent of UV titanium dioxide slurry, 0.1 to 1 percent of surfactant and 0.1 to 1 percent of photo-thermal composite stabilizer; the UV jet printing pretreatment coating prepared by the invention is directly coated on a colored PVC edge band by a roller coater and is connected with a line for UV curing, so that the colored PVC edge band is covered with a white coating, and the white coating is not only a prime coat, but also can be directly used as a finish coat, has good adhesive force to the colored PVC edge band when being used as the white prime coat, provides certain covering power, and can be used as a coating for coating the colored PVC edge band. And after the UV jet printing ink of the PVC edge band is subsequently jet-printed, accurate color expression and the adhesive force of the UV jet printing ink to the colored PVC edge band can be provided.

Description

Technical Field

[0001] The invention relates to the technical field of edge banding strip coatings, in particular to a UV pre-printing treatment coating for PVC edge banding strips, a preparation method and an application thereof. Background Art

[0002] Edge banding was originally used to seal and protect the cross-section of home furnishings and furniture panels, to beautify the decoration, make the panels more waterproof, and prevent the volatilization of formaldehyde inside the panels. It is an indispensable auxiliary material for various decorative panels. There are various edge bandings such as ABS, metal, acrylic, PVC, etc., among which PVC edge banding is the mainstream.

[0003] Entering a new era, competition among companies has shifted from "quality competition" to "decoration competition." The rise of the panel customization market has also led to higher demands for the functionality of edge banding. Consumers have higher requirements for the overall color of their home spaces. At the same time, they have begun to pursue "board edge integration," which means that the color, texture, and even touch of the edge banding and the panel must be consistent. Therefore, the panel edge banding that was previously only available in black, white, gray, brown, or a few basic colors is obviously unable to meet this demand. In order to adapt to development, the existing technology uses inkjet printing technology to print patterns on PVC edge banding strips, but the existing inkjet printing pigments can only perform well on white substrates. For colored edge banding, if the color is directly inkjet printed on the colored edge banding strip, the color cannot be accurately expressed. Therefore, it is urgent to develop a coating on the colored PVC edge banding strip to cover the base color and improve the adhesion of the upper UV inkjet film layer. Therefore, this application proposes a PVC edge banding UV printing pre-treatment coating and its preparation method and application. Summary of the Invention

[0004] The purpose of the present invention is to provide a UV pre-printing treatment coating for PVC edge banding, a preparation method and an application thereof, so as to solve the problems raised in the above background technology.

[0005] According to a first aspect of the present invention, a UV pre-printing treatment coating for PVC edge banding is provided, which is composed of the following components in percentage by weight: Hydroxyethyl methacrylate 5-15%, 1,6-hexanediol diacrylate 5-10%, acylphosphine oxide photoinitiator 4-8%, octyl acrylate 3-8%, polyurethane acrylate oligomer 30-40%, UV adhesion auxiliary resin phosphoric acid modified methacrylate 1-4%, UV titanium dioxide paste 30-40%, surfactant 0.1-1%, photothermal composite stabilizer 0.1-1%.

[0006] Hydroxyethyl methacrylate has the characteristics of low viscosity, low irritation, low shrinkage and low odor. The hydroxyethyl group it contains can also provide active functional groups for the upper ink layer to enhance the adhesion of the ink layer. 1,6-Hexanediol diacrylate is a difunctional monomer with extremely fast curing speed, low odor and strong toughness.

[0007] Octyl acrylate is a monofunctional long-chain monomer.

[0008] According to an embodiment of the present invention, the acylphosphine oxide photoinitiator adopts one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide, and 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester. The photolysis products of the acylphosphine oxide photoinitiator are trimethylbenzoyl and diphenylphosphine. These two types of groups have high initiation activity and fast curing speed. The absorption wavelength can be moved to short wavelength, which has the effect of photobleaching the paint film without yellowing.

[0009] According to an embodiment of the present invention, the polyurethane acrylate oligomer is an aliphatic polyurethane acrylate having a molecular weight of 2000-5000 and a glass transition temperature Tg≤-20°C; The polyurethane acrylate oligomer is selected from one of UH9001 polyurethane acrylate, UH9040 polyurethane acrylate, US035-6H aliphatic polyurethane acrylate, UV7081B polyester acrylate oligomer, and UV7087 acrylate oligomer produced by Guangdong Zhongshan Qianyou Chemical Materials Co., Ltd. This type of oligomer is a UV light-curing resin, and its overall performance in flexibility, adhesion, and elasticity is the most balanced. The present invention applies a multi-functional oligomer with moderate softness and hardness for the UV inkjet printing pre-treatment coating for PVC edge banding, which helps to improve the adhesion and color development performance of the UV inkjet printing ink on the PVC edge banding.

[0010] According to an embodiment of the present invention, the UV titanium dioxide slurry is composed of the following components by weight: 30% rutile titanium dioxide, 60-62% UV monomer, 3% fumed silica matting powder, and 5-7% hyperdispersant.

[0011] According to an embodiment of the present invention, the hyperdispersant is one of the Lubrizol chemical hyperdispersants: Solsperse 32000 and Solsperse 36000.

[0012] According to an embodiment of the present invention, the particle size D99 of the UV titanium dioxide slurry is ≤5 μm.

[0013] Prepare UV titanium dioxide slurry. First, pre-mix the UV monomer and the hyperdispersant and stir until they are completely dissolved. Then add the rutile titanium dioxide from Chemours and the fumed silica matting powder from Evonik, Germany. Stir for 30 minutes until they are completely mixed. Transfer the mixture into a Shanghai Toppa horizontal 1.0L grinder. Keep the system temperature below 50°C during the entire process. Use 1.0mm 95% yttrium-stabilized zirconia beads and perform double-cylinder single-cycle grinding, that is, from cylinder A to cylinder B, and then from cylinder B to cylinder A, grind for 30-40 times, and grind to D. 99 UV titanium dioxide slurry TiO2# 1-6 is produced with a particle size no larger than 5μm, with 99% of the particles being smaller than 5μm. This process utilizes a fully ceramic, turbine, pin-type grinder manufactured by Shanghai Toppa (rotor made of 95% zirconium oxide, stator made of 95% zirconium oxide, and cylinder lining made of silicon carbide). The rutile titanium dioxide is TiO2902 from The Chemours Company.

[0014] The dispersants of Lubrizol Chemicals in the UK contain a large number of pigment-affinity groups, which can reduce the viscosity of the system and provide good dispersibility. These pigment-affinity groups can be firmly anchored on the surface of titanium dioxide, allowing the titanium dioxide to be dispersed and stabilized in the basic particle state. The other block copolymer on the dispersant can play a mutually repulsive role, thereby generating steric hindrance between each tiny titanium dioxide surface particle, forming a grid-like support shape. This support grid can prevent the tiny titanium dioxide surface particles from sinking due to gravity, and prevent the micron-sized titanium dioxide from agglomerating and settling. As a result, the UV pre-printing treatment coating for PVC edge banding applied in the present invention has the characteristics of low viscosity, good hiding power and anti-settling.

[0015] According to an embodiment of the present invention, the UV adhesion auxiliary resin phosphoric acid-modified methacrylate is selected from one of the three types: UC7400 phosphate ester acrylate of Qianyou Chemical Materials Co., Ltd. in Zhongshan City, Guangdong Province, Photomer4703 acid-functionalized acrylate, and Photomer 2203 acid-functionalized methacrylate of IGM Aijianmeng International Trading (Shanghai) Co., Ltd. It is rich in phosphoric acid functional groups and has good adhesion to the substrate, and is particularly suitable for substrates that are difficult to adhere to.

[0016] According to an embodiment of the present invention, the surfactant used is BYK377 leveling agent produced by BYK Chemicals of Germany. This type of surfactant is a polyether / polyester polydimethylsiloxane containing an acrylate functional group, which can not only strongly reduce the surface tension of the system but also has excellent compatibility with the system. The double bonds in the acrylate functional groups contained in the surfactant can also participate in UV light curing polymerization reactions, so that they can be fixed on the surface of the ink layer, providing better surface smoothness and leveling properties.

[0017] The photothermal composite stabilizer uses the UV5151 light stabilizer from Tianjin Lianlong Company, which can capture free radicals and thus inhibit local free radical reactions caused by ultraviolet light. The combined use of the above-mentioned photoinitiator and ultraviolet light absorber can slow down the cross-linking during the use of the coating and enhance the stability of the coating.

[0018] According to a second aspect of the present invention, there is provided a method for preparing a UV pre-printing treatment coating for a PVC edge banding as described above, comprising the following steps: Step 1: Prepare UV titanium dioxide slurry: Mix and dissolve UV monomer and hyperdispersant, then add rutile titanium dioxide and fumed silica matting powder, and grind through double cylinder circulation until D99≤5μm; Step 2: stirring and dissolving hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, and acylphosphine oxide photoinitiator; Step 3: then add octyl acrylate, polyurethane acrylate oligomer, and UV adhesion auxiliary resin phosphoric acid-modified methacrylate in sequence and stir to mix; Step 4: Then add UV titanium dioxide slurry, surfactant, and photothermal composite stabilizer and stir for 30 minutes; Step 5: Filter through a three-stage melt-blown PP filter bag with a filter size of 100 μm → 20 μm → 3 μm to obtain the UV pre-printing treatment coating for the PVC edge banding.

[0019] According to the third aspect of the present invention, there is provided an application of the above-mentioned PVC edge banding UV pre-printing treatment coating in the surface coating of colored PVC edge banding, specifically: loading the PVC edge banding UV pre-printing treatment coating on the PVC edge banding UV coating equipment, setting the line speed of the coating machine, the pressure between the feeding roller, the coating roller, and the transfer roller, turning on the back-end LED-UV curing, etc., and starting coating. According to the subsequent process requirements, the speed, pressure, and light power parameters are changed to finally obtain a coated colored PVC edge banding with good adhesion, qualified whiteness, and glossiness that meets the standards, and enter the back-end printing module with the production line, set the printing mode, and then set the pattern to be output on the computer, send the pattern to the printer, and print the pattern. PVC edge banding UV ink, PVC edge banding digital printing equipment, using Japan Ricoh GEN5 nozzle (resolution exceeds 600×1200dpi), using American PHOTOPrint RIP software converts the image in the computer into a code that can be recognized by the inkjet printer and sends it to the PVC edge strip digital printing machine for printing. During printing, the PVC edge strip temperature is heated to 40-45℃, and the 600x900dpi 6-pass mode is used. The final printed product was found to have no ink flying, ink bleeding, ink blurring, or color loss, and the image is sharp and the color saturation is high.

[0020] Among them, the colored PVC edge banding is coated with PVC edge banding UV printing pre-treatment paint. After the coating thickness is 5-12μm, a white base color can be made. Then the PVC edge banding UV ink is directly sprayed on the surface of the colored PVC edge banding. It has the characteristics of good adhesion, high saturation, bright color, abrasion resistance and bending resistance, realizing the process requirements of integrating PVC edge banding and decorative board finishes.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The UV pre-printing treatment coating prepared by the present invention is directly coated on the colored PVC edge banding strip by a roller coater and then UV-cured in line, so that the colored PVC edge banding strip is covered with a layer of white coating. This white coating serves as both a primer and a topcoat. When used as a white primer, it has good adhesion to the colored PVC edge banding strip and provides a certain covering power, so that after the subsequent printing of the PVC edge banding strip with UV printing ink, accurate color expression can be provided and the UV printing ink has good adhesion to the colored PVC edge banding strip. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] Example 1, selection of UV titanium dioxide slurry, Group TiO2 1# TiO2 2# TiO2 3# TiO2 4# TiO2 5# TiO2 6# UV monomer 60% 60% 62% SOLSPERSE32000 7% 7% 7% 7% SOLSPERSE36000 7% 5% Fumed silica matting powder 3% 3% 3% 3% 3% 3% Rutile titanium dioxide 30% 30% 30% 30% 30% 30% statistics 100% 100% 100% 100% 100% 100% Viscosity cps centipoise 800 600 700 500 700 600 Viscosity after 4 weeks of hot storage 1100 1400 1700 3000 800 650 Heat storage after 4 weeks of settlement 2mm 5mm 3mm 13mm 2mm 2mm It can be seen from the above table that based on the screening and analysis of prefabricated titanium dioxide slurry, the TiO2 6# formula with the most stable viscosity and the best anti-settling effect is the best.

[0024] Example 2, selection of polyurethane acrylate oligomer, Group 1 2 3 4 5 6 7 8 HEMA 11% 11% 11% 11% 11% 11% 14% 11% HDDA 7% 7% 7% 7% 7% 5% Initiator TPO 5% 5% 5% 5% 5% 5% 5% 5% UH9001 36% UH9040 36% 38% 40% 42% US035-6H 36% UV7081B 36% UV7087 36% UC7400 2% 2% 2% 2% 2% 2% 2% 2% PHEA 4.6% 4.6% 4.6% 4.6% 4.6% 4.6% 4.6% 4.6% TiO2 6# 34% 34% 34% 34% 34% 34% 34% 34% BYK377 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% Composite stabilizer 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% statistics 100% 100% 100% 100% 100% 100% 100% 100% Curing speed NG OK NG NG OK OK OK OK Adhesion - OK - - NG OK OK OK Leveling - - - - - - - - Bending resistance - NG - - - OK OK OK Upper layer adhesion - - - - - - OK OK In the table, OK means the test passed; NG means the test failed.

[0025] As can be seen from the table above, based on the test results of curing speed, adhesion, bending resistance, and adhesion to the upper ink layer, UH9040 polyurethane acrylate is the best choice for polyurethane acrylate oligomer.

[0026] Example 3, Selection of Acylphosphine Oxide Photoinitiators, Group 1 2 3 4 5 6 7 8 HEMA 11% 10% 11% 9% 11% 11% 11% 10% HDDA 0% 0% 0% 0% 0% 0% 0% 0% Initiator TPO 5% 7% TPO-L 6% 8% 819 4% 5% TMO 6% 8% UH9040 40% 40% 40% 40% 40% 40% 40% 40% UC7400 2% 2% 2% 2% 2% 2% 2% 2% PHEA 5.6% 4.6% 4.6% 4.6% 6.6% 5.6% 4.6% 4.6% TiO2 6# 36% 36% 36% 36% 36% 36% 36% 36% BYK377 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% Composite stabilizer 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% statistics 100% 100% 100% 100% 100% 100% 100% 100% Curing speed OK OK NG NG OK OK OK OK Adhesion OK OK - - O OK OK OK Degree of yellowing OK OK - - NG NG OK NG Bending resistance OK OK - - - - OK - Upper layer adhesion OK NG - - - - OK - In the table, OK means the test passed; NG means the test failed.

[0027] As can be seen from the table above, based on the test results of curing speed, adhesion, yellowing resistance, bending resistance, and adhesion to the upper ink layer, the acylphosphine oxide photoinitiator uses the 1# 7# formula for the best effect.

[0028] TPO-L curing efficiency is completely below the TPO standard, so it is abandoned. 819 / BOAO curing efficiency is lower than TPO, but it is completely below the TPO standard. TMO curing efficiency is close to the TPO standard, and yellowing is acceptable. 7# is used in products exported to the EU.

[0029] Example 4, selection of UV adhesion promoting resin; Group 1 2 3 4 5 6 HEMA 11% 11% 11% 11% 11% 11% HDDA 0% 0% 0% 0% 0% 0% Initiator TPO 5% 5% 5% 5% 5% 5% UH9040 40% 40% 40% 40% 40% 40% UC7400 2% 3% 4% Photomer4703 2% 3% Photomer 2203 3% PHEA 5.6% TiO2 6# 36% 36% 36% 36% 36% 36% BYK377 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% Composite stabilizer 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% statistics 100% 100% 100% 100% 100% 100% Curing speed OK OK OK OK OK OK Adhesion OK OK OK NG OK OK Upper layer adhesion OK OK OK - OK OK In the table, OK means the test passed; NG means the test failed.

[0030] As can be seen from the table above, based on the evaluation results of curing speed, adhesion, and adhesion to the upper ink layer, UC7400 is the most effective UV adhesion-promoting resin.

[0031] To sum up, this application loads the PVC edge banding UV printing pre-treatment coating on the PVC edge banding UV coating equipment, sets the line speed of the coating machine, the pressure between the feeding roller, the coating roller, and the transfer roller, turns on the rear-stage LED-UV curing, etc., starts coating, and changes the speed, pressure, and light power parameters according to the subsequent process requirements to finally obtain a coated colored PVC edge banding with good adhesion, qualified whiteness, and glossiness that meets the standards, and enters the rear-stage printing module along the production line, sets the printing mode, and then sets the pattern to be output on the computer, sends the pattern to the printer, and prints the pattern. PVC edge banding UV ink, PVC edge banding digital printing equipment, uses Japan Ricoh GEN5 nozzle (resolution exceeds 600×1200dpi), and uses American PHOTOPrint RIP Ruipu software to convert the pattern in the computer into a code that can be recognized by the inkjet printer and send it to the PVC edge banding digital printing equipment for printing; when printing, the PVC edge strip temperature is heated to 40-45°C, and 600x900dpi is used. 6-pass mode; in the end, it was found that the printed product had no ink flying, ink bleeding, ink blurring, or color missing, and the picture was sharp and the color saturation was high.

[0032] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A UV pre-printing treatment coating for PVC edge banding, characterized in that: According to weight percentage, it is composed of the following ingredients: Hydroxyethyl methacrylate 5-15%, 1,6-hexanediol diacrylate 5-10%, acylphosphine oxide photoinitiator 4-8%, octyl acrylate 3-8%, polyurethane acrylate oligomer 30-40%, UV adhesion auxiliary resin phosphoric acid modified methacrylate 1-4%, UV titanium dioxide paste 30-40%, surfactant 0.1-1%, photothermal composite stabilizer 0.1-1%.

2. The UV pre-printing treatment coating for PVC edge banding according to claim 1, characterized in that: The acylphosphine oxide photoinitiator is one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-di(p-tolyl)phosphine oxide and 2,4,6-trimethylbenzoylphenyl ethylphosphonate.

3. The UV pre-printing treatment coating for PVC edge banding according to claim 1, characterized in that: The polyurethane acrylate oligomer is an aliphatic polyurethane acrylate with a molecular weight of 2000-5000 and a glass transition temperature Tg≤-20°C.

4. The UV pre-printing treatment coating for PVC edge banding according to claim 1, characterized in that: The UV titanium dioxide slurry is composed of the following components in percentage by weight: 30% rutile titanium dioxide, 60-62% UV monomer, 3% fumed silica matting powder, 5-7% hyperdispersant.

5. The UV pre-printing treatment coating for PVC edge banding according to claim 4, characterized in that: The hyperdispersant is one of Solsperse 32000 and Solsperse 36000.

6. The UV pre-printing treatment coating for PVC edge banding according to claim 1, characterized in that: The particle size D99 of the UV titanium dioxide slurry is ≤5 μm.

7. The UV pre-printing treatment coating for PVC edge banding according to claim 1, characterized in that: The UV adhesion auxiliary resin phosphoric acid modified methacrylate is one of UC7400 phosphate ester acrylate, Photomer 4703 acid functionalized acrylate, and Photomer 2203 acid functionalized methacrylate.

8. The UV pre-printing treatment coating for PVC edge banding according to claim 1, characterized in that: The surfactant is BYK377 leveling agent; the photothermal composite stabilizer is UV5151 light stabilizer.

9. A method for preparing a UV pre-printing treatment coating for PVC edge banding according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Prepare UV titanium dioxide slurry: Mix and dissolve UV monomer and hyperdispersant, then add rutile titanium dioxide and fumed silica matting powder, and grind through double cylinder circulation until D99≤5μm; Step 2: stirring and dissolving hydroxyethyl methacrylate, 1,6-hexanediol diacrylate, and acylphosphine oxide photoinitiator; Step 3: then add octyl acrylate, polyurethane acrylate oligomer, and UV adhesion auxiliary resin phosphoric acid-modified methacrylate in sequence and stir to mix; Step 4: Then add UV titanium dioxide slurry, surfactant, and photothermal composite stabilizer and stir for 30 minutes; Step 5: Filter through a three-stage melt-blown PP filter bag with a filter size of 100 μm → 20 μm → 3 μm to obtain the UV pre-printing treatment coating for the PVC edge banding.

10. Use of the UV pre-printing treatment coating for PVC edge banding according to any one of claims 1 to 8 in surface coating of colored PVC edge banding.