Preparation method of PVC film photolithography for vacuum-formable UV coating

Abstract

This invention relates to the field of UV coating technology, specifically a method for preparing a PVC film photolithography-compatible UV coating, comprising: pouring PUA prepolymer and modified diluent into a high-speed mixer for uniform mixing; adding slow-release filler and photoinitiator to the high-speed mixer and mixing uniformly to obtain a mixture; and filtering and degassing the mixture to obtain a PVC film photolithography-compatible UV coating. The UV coating prepared by this invention, through the combined use of slow-release filler and modified diluent, improves the wear resistance, self-healing properties, and flexibility of the coating film, allowing for better application in blister packaging and effectively avoiding coating cracking or peeling caused by deformation of the blister packaging film.

Description

Technical Field

[0001] This invention relates to the field of UV coating technology, specifically a method for preparing blister-formable UV coatings using PVC film photolithography. Background Technology

[0002] Vacuum-formable UV coatings, also known as UV-cured coatings, offer excellent feel and scratch resistance. When applied to PVC film and cured with UV light, they can be vacuum-formed into a single unit with composite panels. They can be applied flat or bent for edge wrapping, making them widely applicable.

[0003] Adding particulate fillers to UV coatings can improve their corrosion resistance and abrasion resistance, but the coating's flexibility is poor. During vacuum forming, the coating deforms along with the PVC film; poor coating flexibility easily leads to cracking, affecting product quality. Therefore, a method for preparing vacuum-formable UV coatings using PVC film photolithography is proposed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing PVC film photolithography-based blister-formable UV coatings. By combining slow-release fillers and modified diluents, the wear resistance, self-healing properties, and flexibility of the coating are improved.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a PVC film photolithography-based thermoforming UV coating, comprising the following steps:

[0006] (1) Pour the PUA prepolymer and the modified diluent into a high-speed mixer and mix them evenly;

[0007] (2) Add the slow-release filler and photoinitiator to the high-speed mixer and mix them evenly to obtain a mixture;

[0008] (3) After the mixture is filtered and degassed, a PVC film photolithography process can be used to make a vacuum-formable UV coating.

[0009] Preferably, in step (1), the preparation method of the PUA prepolymer is as follows: S1-1, isophorone diisocyanate and dibutyltin dilaurate are stirred and mixed, then castor oil and acetone are added dropwise, and after being kept at 50-60℃ for 2-3h, hydroxyethyl acrylate, pentaerythritol tetraacrylate and 4-methoxyphenol are added dropwise and the reaction is continued for 3-4h to obtain the reaction material; S1-2, the reaction material is rotary evaporated to remove acetone to obtain the PUA prepolymer.

[0010] Preferably, in step S1-1, the mass ratio of isophorone diisocyanate, dibutyltin dilaurate, castor oil, hydroxyethyl acrylate, pentaerythritol tetraacrylate and 4-methoxyphenol is (9-10):(0.1-0.15):(12-15):(5-6):(2-3):(0.05-0.06).

[0011] Preferably, in step S1-1, the ratio of castor oil to acetone is 1:3 g / mL.

[0012] Preferably, in step (1), the modified diluent is prepared as follows: S2-1, cashew phenol, 4-(dimethylamino)pyridine, triethylamine, 4-methoxyphenol and tetrahydrofuran are mixed evenly, cooled to 0°C, acryloyl chloride is added with stirring, and then reacted at 40-45°C for 5-7 hours to obtain a premix; S2-2, the premix is ​​extracted with diethyl ether, washed with saturated sodium bicarbonate and deionized water in sequence, the upper layer solution is taken and dried with anhydrous magnesium sulfate, and then filtered and rotary evaporated to remove diethyl ether to obtain the modified diluent.

[0013] Preferably, in step S2-1, the mass ratio of cashew phenol, 4-(dimethylamino)pyridine, triethylamine, 4-methoxyphenol and acryloyl chloride is (28-30):(0.5-0.6):(10-12):(0.10-0.15):(9-10).

[0014] Preferably, in step S2-1, the ratio of triethylamine to tetrahydrofuran is 1:2 g / mL.

[0015] Preferably, in step (2), the method for preparing the slow-release filler is as follows: hollow mesoporous silica microspheres are poured into flaxseed oil and ultrasonically treated for 3-5 hours; after filtration, the surface is dried and sprayed with polyvinyl alcohol solution, and after drying, the slow-release filler is obtained.

[0016] Preferably, in step (2), the photoinitiator is selected from photoinitiator 1173.

[0017] The present invention also provides a PVC film photolithography process blister-formable UV coating, which comprises the following raw materials by weight percentage: 60-75% PUA prepolymer, 15-20% modified diluent, 10-15% slow-release filler, and 2-4% photoinitiator.

[0018] This invention provides a method for preparing a vacuum-formable UV coating using PVC film photolithography, which has the following advantages compared to existing technologies:

[0019] The UV coating prepared by this invention improves the wear resistance, self-healing properties and flexibility of the coating film by using a combination of slow-release filler and modified diluent, so that the coating film can be better applied to blister films and effectively avoids the problem of coating cracking or peeling caused by deformation of blister films.

[0020] This invention utilizes the reaction of chlorinated acrylic acid with the phenolic hydroxyl groups of cashew phenol to prepare a modified diluent, which is then added to the coating. Its side-chain alkyl aliphatic chain structure increases the flexibility of the coating film, allowing the coating film to withstand greater deformation without cracking, making it well-suited for use in blister packaging films.

[0021] This invention involves coating linseed oil into hollow mesoporous silica microspheres. When cracks appear in the coating, the polyvinyl alcohol film ruptures, allowing the internal linseed oil to flow out to the cracks and come into contact with oxygen. The linolenic acid then cross-links and solidifies, thus healing the cracks. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0023] Figure 1 This is the infrared spectrum of the PUA prepolymer in Example 2 of the present invention. Detailed Implementation

[0024] The following embodiments are provided to illustrate the implementation of this application in detail, so that the process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0025] Example 1

[0026] The preparation method of PUA prepolymer is as follows:

[0027] S1-1. Isophorone diisocyanate and dibutyltin dilaurate were stirred and mixed, then castor oil and acetone were added dropwise. After keeping the mixture at 60°C for 2 hours, hydroxyethyl acrylate, pentaerythritol tetraacrylate and 4-methoxyphenol were added dropwise and the reaction was continued for 4 hours to obtain the reaction material.

[0028] The mass ratio of isophorone diisocyanate, dibutyltin dilaurate, castor oil, hydroxyethyl acrylate, pentaerythritol tetraacrylate, and 4-methoxyphenol is 10:0.1:15:5:3:0.05; the ratio of castor oil to acetone is 1:3 g / mL.

[0029] S1-2. The acetone in the reactants is removed by rotary evaporation to obtain the PUA prepolymer.

[0030] Example 2

[0031] The preparation method of PUA prepolymer is as follows:

[0032] S1-1. Isophorone diisocyanate and dibutyltin dilaurate are stirred and mixed, then castor oil and acetone are added dropwise. After keeping the mixture at 50°C for 3 hours, hydroxyethyl acrylate, pentaerythritol tetraacrylate and 4-methoxyphenol are added dropwise and the reaction continues for 3 hours to obtain the reaction material.

[0033] The mass ratio of isophorone diisocyanate, dibutyltin dilaurate, castor oil, hydroxyethyl acrylate, pentaerythritol tetraacrylate, and 4-methoxyphenol is 9:0.15:12:6:2:0.06; the material-to-liquid ratio of castor oil to acetone is 1:3 g / mL.

[0034] S1-2. The acetone in the reactants is removed by rotary evaporation to obtain the PUA prepolymer.

[0035] Example 3

[0036] The preparation method of the modified diluent is as follows:

[0037] S2-1. Cashew phenol, 4-(dimethylamino)pyridine, triethylamine, 4-methoxyphenol and tetrahydrofuran are mixed evenly, cooled to 0°C, and acryloyl chloride is added with stirring. Then the mixture is reacted at 45°C for 5 hours to obtain a premix.

[0038] The mass ratio of cashew phenol, 4-(dimethylamino)pyridine, triethylamine, 4-methoxyphenol and acryloyl chloride is 30:0.5:12:0.10:10; the material-to-liquid ratio of triethylamine and tetrahydrofuran is 1:2 g / mL.

[0039] S2-2. The premix was successively extracted with diethyl ether, washed with saturated sodium bicarbonate and deionized water. The supernatant was taken and dried with anhydrous magnesium sulfate. The diethyl ether was then removed by filtration and rotary evaporation to obtain the modified diluent.

[0040] Example 4

[0041] The preparation method of the modified diluent is as follows:

[0042] S2-1. Cashew phenol, 4-(dimethylamino)pyridine, triethylamine, 4-methoxyphenol and tetrahydrofuran are mixed evenly, cooled to 0°C, and acryloyl chloride is added with stirring. Then the mixture is reacted at 40°C for 7 hours to obtain a premix.

[0043] The mass ratio of cashew phenol, 4-(dimethylamino)pyridine, triethylamine, 4-methoxyphenol, and acryloyl chloride was 28:0.6:10:0.15:9; the material-to-liquid ratio of triethylamine and tetrahydrofuran was 1:2 g / mL. S2-2, the premix was successively extracted with diethyl ether, washed with saturated sodium bicarbonate, and washed with deionized water. The supernatant was collected and dried over anhydrous magnesium sulfate, then filtered and rotary evaporated to remove the diethyl ether, yielding the modified diluent.

[0044] Example 5

[0045] A method for preparing PVC film photolithography-based thermoforming UV coatings includes the following steps:

[0046] (1) The following raw materials are prepared by weight percentage: 68% PUA prepolymer, 15% modified diluent, 15% slow-release filler, and 11732% photoinitiator;

[0047] The preparation method of the above-mentioned slow-release filler is as follows: Hollow mesoporous silica microspheres (particle size of 3-5 μm, mesopore size of 10 nm or more) are poured into flaxseed oil and ultrasonically treated for 5 h; after filtration, the surface is dried and sprayed with polyvinyl alcohol solution. After drying, the slow-release filler is obtained.

[0048] (2) Pour the PUA prepolymer and the modified diluent into a high-speed mixer and mix them evenly;

[0049] (3) Add the slow-release filler and photoinitiator 1173 to the high-speed mixer and mix them evenly to obtain a mixture;

[0050] (4) After the mixture is filtered and degassed, a UV coating that can be vacuum-formed using PVC film photolithography is obtained.

[0051] In this embodiment, the PUA prepolymer from Example 1 and the modified diluent from Example 3 are used.

[0052] Example 6

[0053] A method for preparing PVC film photolithography-based thermoforming UV coatings includes the following steps:

[0054] (1) The following raw materials are prepared by weight percentage: 66% PUA prepolymer, 20% modified diluent, 10% slow-release filler, and 11734% photoinitiator.

[0055] The preparation method of the above-mentioned slow-release filler is as follows: Hollow mesoporous silica microspheres (particle size of 3-5 μm, mesopore size of 10 nm or more) are poured into flaxseed oil and ultrasonically treated for 3 h; after filtration, the surface is dried and sprayed with polyvinyl alcohol solution. After drying, the slow-release filler is obtained.

[0056] (2) Pour the PUA prepolymer and the modified diluent into a high-speed mixer and mix them evenly;

[0057] (3) Add the slow-release filler and photoinitiator 1173 to the high-speed mixer and mix them evenly to obtain a mixture;

[0058] (4) After the mixture is filtered and degassed, a UV coating that can be vacuum-formed using PVC film photolithography is obtained.

[0059] In this embodiment, the PUA prepolymer from Example 2 and the modified diluent from Example 3 are used.

[0060] Example 7

[0061] A method for preparing PVC film photolithography-based thermoforming UV coatings includes the following steps:

[0062] (1) The following raw materials are prepared by weight percentage: 70% PUA prepolymer, 15% modified diluent, 12% slow-release filler, and 11733% photoinitiator.

[0063] The preparation method of the above-mentioned slow-release filler is as follows: Hollow mesoporous silica microspheres (particle size of 3-5 μm, mesopore size of 10 nm or more) are poured into flaxseed oil and ultrasonically treated for 4 h; after filtration, the surface is dried and sprayed with polyvinyl alcohol solution. After drying, the slow-release filler is obtained.

[0064] (2) Pour the PUA prepolymer and the modified diluent into a high-speed mixer and mix them evenly;

[0065] (3) Add the slow-release filler and photoinitiator 1173 to the high-speed mixer and mix them evenly to obtain a mixture;

[0066] (4) After the mixture is filtered and degassed, a UV coating that can be vacuum-formed using PVC film photolithography is obtained.

[0067] In this embodiment, the PUA prepolymer from Example 2 and the modified diluent from Example 4 are used.

[0068] Comparative Example 1

[0069] A method for preparing PVC film photolithography-based thermoforming UV coatings includes the following steps:

[0070] (1) The following raw materials are prepared by weight percentage: 82% PUA prepolymer, 15% modified diluent, and 11733% photoinitiator.

[0071] (2) Pour the PUA prepolymer and the modified diluent into a high-speed mixer and mix them evenly;

[0072] (3) Add photoinitiator 1173 to the high-speed mixer and mix evenly to obtain a mixture;

[0073] (4) After the mixture is filtered and degassed, a UV coating that can be vacuum-formed using PVC film photolithography is obtained.

[0074] In this comparative example, the PUA prepolymer from Example 2 and the modified diluent from Example 4 were used.

[0075] Comparative Example 2

[0076] A method for preparing PVC film photolithography-based thermoforming UV coatings includes the following steps:

[0077] (1) The following raw materials are prepared by weight percentage: 70% PUA prepolymer, 15% modified diluent, 12% hollow mesoporous silica microspheres, and 11733% photoinitiator.

[0078] (2) Pour the PUA prepolymer and the modified diluent into a high-speed mixer and mix them evenly;

[0079] (3) Add hollow mesoporous silica microspheres (particle size of 3-5 μm, mesopore size of 10 nm or more) and photoinitiator 1173 to a high-speed stirrer and mix them evenly to obtain a mixture;

[0080] (4) After the mixture is filtered and degassed, a UV coating that can be vacuum-formed using PVC film photolithography is obtained.

[0081] In this comparative example, the PUA prepolymer from Example 2 and the modified diluent from Example 4 were used.

[0082] Comparative Example 3

[0083] A method for preparing PVC film photolithography-based thermoforming UV coatings includes the following steps:

[0084] (1) The following raw materials are prepared by weight percentage: 70% PUA prepolymer, 15% hydroxyethyl methacrylate diluent, 12% slow-release filler, and 11733% photoinitiator.

[0085] The preparation method of the above-mentioned slow-release filler is as follows: hollow mesoporous silica microspheres are poured into flaxseed oil and ultrasonically treated for 4 hours; after filtration, the surface is dried and sprayed with polyvinyl alcohol solution. After drying, the slow-release filler is obtained.

[0086] (2) Pour the PUA prepolymer and hydroxyethyl methacrylate diluent into a high-speed mixer and mix them evenly.

[0087] (3) Add the slow-release filler and photoinitiator 1173 to the high-speed mixer and mix them evenly to obtain a mixture;

[0088] (4) After the mixture is filtered and degassed, a UV coating that can be vacuum-formed using PVC film photolithography is obtained.

[0089] In this comparative example, the PUA prepolymer from Example 2 was used.

[0090] Quality Inspection

[0091] Using the PVC film photolithography process vacuum-formable UV coatings in Examples 5-7 and Comparative Examples 1-3 as test samples, the coatings were applied to thin films and then photocured to obtain the coating film.

[0092] 1. The coating abrasion tester was used for measurement, with the load controlled at 1×10⁻⁶. 4 N, starting at 100 revolutions. The abrasion resistance calculation formula is as follows: Abrasion resistance = (mass of the coating sample before wear - mass of the coating sample before wear) / coating thickness. The elongation at break of the coating was tested according to GB / T2567-2008 standard. The specific results are shown in the table below.

[0093] Table 1 Abrasion resistance and elongation at break

[0094] category Abrasion resistance (mg / μm) Elongation at break (%) Example 5 3.1 15.0 Example 6 3.0 16.4 Example 7 2.8 15.5 Comparative Example 1 4.6 15.2 Comparative Example 2 3.2 14.9 Comparative Example 3 3.3 10.7

[0095] As can be seen from the table above: compared with Example 7, no slow-release filler was added in Comparative Example 1, which resulted in a significant decrease in the wear resistance of the coating film; compared with Example 7, no modified diluent was used in Comparative Example 3, which resulted in poor toughness.

[0096] 2. Scratch self-healing and repeated self-healing: A fine scratch was made on the coating surface with a scalpel, and it self-healed at room temperature until the fine crack disappeared. After the scratch self-healed, another fine crack was made in the same location, and the above operation was repeated to observe whether the crack could continue to self-heal. The specific test results are shown in the table below.

[0097] Table 2 Self-healing properties

[0098] category Healing status Repeated self-healing times Example 5 heal 13 Example 6 heal 12 Example 7 heal 14 Comparative Example 1 Unhealed / Comparative Example 2 Unhealed / Comparative Example 3 heal 13

[0099] As can be seen from the table above, no slow-release filler was used in Comparative Example 1, so there was no tendency for self-healing. This shows that the use of slow-release filler can indeed give the coating film better self-healing properties.

[0100] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing PVC film photolithography-based thermoforming UV coatings, characterized in that, Includes the following steps: (1) Pour the PUA prepolymer and the modified diluent into a high-speed mixer and mix them evenly; (2) Add the slow-release filler and photoinitiator to the high-speed mixer and mix them evenly to obtain a mixture; (3) After the mixture is filtered and degassed, a UV coating that can be vacuum-formed using PVC film photolithography is obtained; In step (1), the preparation method of the PUA prepolymer is as follows: S1-1. Isophorone diisocyanate and dibutyltin dilaurate are stirred and mixed, then castor oil and acetone are added dropwise. After keeping the mixture at 50-60℃ for 2-3 hours, hydroxyethyl acrylate, pentaerythritol tetraacrylate and 4-methoxyphenol are added dropwise and the reaction continues for 3-4 hours to obtain the reaction material. S1-2. The reactants are rotary evaporated to remove acetone, and PUA prepolymer is obtained. In step (1), the modified diluent is prepared as follows: S2-1. Cashew phenol, 4-(dimethylamino)pyridine, triethylamine, 4-methoxyphenol and tetrahydrofuran are mixed evenly, cooled to 0°C, and acryloyl chloride is added with stirring. Then the mixture is reacted at 40-45°C for 5-7 hours to obtain a premix. S2-2. The premix was successively extracted with diethyl ether, washed with saturated sodium bicarbonate and deionized water. The supernatant was taken and dried with anhydrous magnesium sulfate. Then, the diethyl ether was removed by filtration and rotary evaporation to obtain the modified diluent. In step (2), the slow-release filler is prepared as follows: hollow mesoporous silica microspheres are poured into flaxseed oil and ultrasonically treated for 3-5 hours; after filtration, the surface is dried and sprayed with polyvinyl alcohol solution. After drying, the slow-release filler is obtained.

2. The method for preparing PVC film photolithography-processable UV coating according to claim 1, characterized in that, In step S1-1, the mass ratio of isophorone diisocyanate, dibutyltin dilaurate, castor oil, hydroxyethyl acrylate, pentaerythritol tetraacrylate and 4-methoxyphenol is (9-10):(0.1-0.15):(12-15):(5-6):(2-3):(0.05-0.06).

3. The method for preparing PVC film photolithography-processable UV coating according to claim 1, characterized in that, In step S1-1, the ratio of castor oil to acetone is 1:3 g / mL.

4. The method for preparing PVC film photolithography-processable UV coating according to claim 1, characterized in that, In step S2-1, the mass ratio of cashew phenol, 4-(dimethylamino)pyridine, triethylamine, 4-methoxyphenol and acryloyl chloride is (28-30):(0.5-0.6):(10-12):(0.10-0.15):(9-10).

5. The method for preparing a PVC film photolithography-processable UV coating according to claim 1, characterized in that, In step S2-1, the ratio of triethylamine to tetrahydrofuran is 1:2 g / mL.

6. The method for preparing PVC film photolithography-processable UV coating according to claim 1, characterized in that, In step (2), the photoinitiator is selected from photoinitiator 1173.

7. The PVC film photolithography-processable blister UV coating prepared by the preparation method according to any one of claims 1-6, characterized in that, By weight percentage, it includes the following raw materials: 60-75% PUA prepolymer, 15-20% modified diluent, 10-15% slow-release filler, and 2-4% photoinitiator.

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