Glass temporary protection LED curing coating and preparation method thereof

Abstract

The invention relates to a glass temporary protection UV (ultraviolet) coating and a preparation method thereof. The glass temporary protection UV coating is prepared from anhydride modified polyurethane multifunctional acrylate, polyethylene glycol di (methyl) acrylate, acryloyl morpholine, dimethylacrylamide 1, methacrylic acid phosphate, a silane coupling agent, a photoinitiator, a leveling aid and the like. The radiation curing glass temporary protective coating provided by the invention has the advantages that the use is simple and convenient (curing can be completed within 1-2S to form protection), the film-forming adhesive force is excellent after the coating is irradiated by ultraviolet light with certain energy, the physical resistance of the coating film is good (scratching, scratching and peeling in the transportation, use and processing processes are avoided), and the coating film is easy to be separated after being soaked in alkaline water in the later period.

Description

Technical Field

[0001] The invention relates to the field of temporary protective coatings, in particular to a temporary protective UV coating for glass which is simple to prepare, has high hardness and is easy to clean, and a preparation method thereof. Background Art

[0002] With the increasing global awareness of environmental protection and increasingly stringent environmental regulations, consumers are increasingly eager for environmentally friendly products. UV coatings, with their significant advantages of low volatile organic compound emissions, are showing unlimited market potential, especially in the field of LED light curing. It is an inevitable trend to take it as the primary development direction, overcoming the shortcomings of traditional mercury lamp curing, such as short working life, potential mercury pollution, severe heat generation, and unstable ultraviolet light output.

[0003] Glass products can be seen everywhere in daily life, such as automobile glass, home decoration glass, and mobile phone screen protector glass. They are very susceptible to damage and pollution during daily processing. Temporarily coating a protective film on their surface is an important means of protection. In the existing technical field, there are common problems such as difficulty in film removal, long time consumption, and high labor consumption. There are also some solvent-based temporary protective coatings that contain volatile toxic and harmful solvents, which are harmful to the human body and the environment. Therefore, it is urgent to develop a temporary protective coating that is easy to remove, efficient, and environmentally friendly. Combined with the characteristics of UV radiation curing, the present invention provides a preparation method for an LED radiation curing coating that has good adhesion to glass, high hardness, and is easy to operate. After the protection is completed, the film can be easily removed by soaking in alkaline water. Summary of the invention

[0004] The purpose of the present invention is to provide a LED curing coating and a preparation method thereof which is simple to prepare, efficient, high hardness and easy to remove after protection is completed, in view of the defects of all the above-mentioned technologies.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A glass temporary protection LED curing coating, comprising the following components in parts by weight:

[0007] 50-70 parts of anhydride modified polyurethane multifunctional acrylate;

[0008] UV active monomer - 10-30 parts;

[0009] UV active monomer 2 10-25 parts;

[0010] 1 part of methacrylate phosphate;

[0011] 1 part of silane coupling agent;

[0012] 3-5 parts of photoinitiator;

[0013] 0.3 parts of leveling agent.

[0014] As a preferred solution, in the above-mentioned LED curing coating for temporary protection of glass, the anhydride-modified polyurethane multifunctional acrylate is a resin with the following structure, n≥0. According to the actual required performance, the actual value of n is preferably 4.

[0015]

[0016] As a preferred embodiment, the method for preparing the anhydride-modified polyurethane multifunctional acrylate of the present invention comprises the following steps:

[0017] (1) adding isophorone diisocyanate (IPDI), dibutyltin dilaurate as a catalyst, and p-hydroxyanisole as a polymerization inhibitor to pentaerythritol triacrylate, reacting at 80-90° C. for 2 hours, and when the NCO reaches the theoretical value, obtaining the first step intermediate product A;

[0018] (2) The intermediate product A obtained in the first step is cooled to 40-50° C., tetraethylene glycol is added, and dibutyltin dilaurate is added as a catalyst. After reacting at 80-90° C. for 2 hours, when the NCO theoretical value is , the intermediate product B in the second step is obtained;

[0019] (3) The intermediate product B obtained in the second step is cooled to 40-50°C, and trimellitic anhydride is added, triphenylphosphine is used as a catalyst, and the reaction is carried out at 110-120°C for 3 hours, and the temperature is kept for 1 hour. When the acid value reaches the theoretical value, anhydride-modified polyurethane multifunctional acrylate is obtained.

[0020] As a preferred embodiment, in the above-mentioned glass temporary protection LED curing coating, the first UV active monomer is a bifunctional active monomer PEG200DA (polyethylene glycol diacrylate).

[0021] As a preferred embodiment, in the above-mentioned LED-cured coating for temporary protection of glass, the second monomer is one or a combination of two of the monofunctional active monomers dimethylacrylamide (DMAA) and acryloylmorpholine (ACMO).

[0022] As a preferred embodiment, the methacrylate phosphate mentioned above is 2-hydroxyethyl methacrylate phosphate. The methacrylate phosphate is produced by Changxing Company in Taiwan, China, and the product brand is EM39.

[0023] As a preferred embodiment, the photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, produced by Tianjin Jiuri New Materials, code-named TPO.

[0024] As a preferred solution, the silane coupling agent is 3-methacryloxypropyltrimethoxysilane, produced by Shin-Etsu Corporation of Japan, with the code name KBM-503.

[0025] As a preferred solution, the polyether-modified silicone leveling agent is the 333 leveling agent produced by BYK.

[0026] The invention provides a method for preparing a glass temporary protection LED curing coating, comprising the following steps: adding UV active monomer 1, monomer 2, methyl methacrylate phosphate, silane coupling agent, photoinitiator and leveling agent into a high-speed dispersing kettle according to a formula, rotating at a speed of 800 to 1200 revolutions per minute, stirring for 60 to 80 minutes, then adding anhydride modified polyurethane multifunctional acrylate, continuing to stir for 40 to 60 minutes, and after uniform dispersion, vacuum degassing to obtain the glass temporary protection LED curing coating.

[0027] More preferably, the present invention provides a method for preparing a UV wear-resistant skin-feel coating, comprising the following steps:

[0028] (1) First, the UV active monomer 1, active monomer 2, and initiator are placed in a dispersion tank at 800-1200 rpm for 30 min to dissolve and stir evenly;

[0029] (2) adding methacrylate phosphate and silane coupling agent into the dispersion tank of step 1 and dispersing for another 30 minutes;

[0030] (3) Slowly add the leveling agent and disperse at high speed for 20 minutes;

[0031] (4) adding the anhydride-modified polyurethane multifunctional acrylate into the dispersion tank of step 3 and dispersing at high speed for 60 minutes;

[0032] (5) Finally, the mixture obtained in step 4 is subjected to vacuum degassing, 300-mesh filtration, and packaging to obtain a glass temporary protection LED curing coating.

[0033] The present invention has the following advantages and beneficial effects:

[0034] 1. The LED curing coating for temporary protection of glass provided by the present invention has the characteristics of rapid curing under LED irradiation and can be cured into a film in only 1 to 2 seconds. The finished coating does not contain volatile organic solvents and is in line with the concept of environmental protection.

[0035] 2. The LED curing coating for temporary protection of glass provided by the present invention has a relatively high hardness and can protect the glass from being scratched during processing and transportation.

[0036] 3. The glass temporary protection LED curing coating provided by the present invention forms a film with extremely strong adhesion on the glass surface due to the introduction of multiple effective ingredients and the combination in a reasonable proportion. It has good protective performance during processing, does not fall off, and the protective film does not collapse during cutting processing, and is resistant to corrosion by cutting fluid.

[0037] 4. The glass temporary protection LED curing coating provided by the present invention has a fast film stripping speed after processing, which can be completed in 1 minute. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the structure of anhydride-modified polyurethane multifunctional acrylate. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below by examples. These examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0040] 1. The anhydride-modified polyurethane multifunctional acrylate described in the following examples has the following structure:

[0041]

[0042] Anhydride-modified polyurethane multifunctional acrylate is prepared by the following method:

[0043] (1) In a four-necked flask at room temperature, 1 mol of isophorone diisocyanate (IPDI), 0.2 g of dibutyltin dilaurate as a catalyst, and 2 g of p-hydroxyanisole as a polymerization inhibitor are slowly added dropwise to 1 mol of pentaerythritol triacrylate. The addition is completed in half an hour. There is a certain amount of heat release during the addition process. The temperature is controlled below 80° C., and then the reaction is carried out at 80-90° C. for 2 hours. When NCO ≤ 8.3%, the first intermediate product A is obtained;

[0044] (2) cooling the intermediate product A obtained in the first step to 40-50° C., adding 1 mol of tetraethylene glycol dropwise, and adding 0.2 g of dibutyltin dilaurate catalyst after the addition is complete. The mixture is kept at 80-90° C. for 2 hours. When NCO ≤ 0.3%, the intermediate product B in the second step is obtained.

[0045] (3) The intermediate product B obtained in the second step is cooled to 40-50° C., and then 1 mol of trimellitic anhydride is added, and 3 g of triphenylphosphine is used as a catalyst. The reaction is carried out at 110-120° C. for 3 hours, and the temperature is kept for 1 hour. When the acid value is ≤125 mg KOH / g, anhydride-modified polyurethane multifunctional acrylate is obtained.

[0046] 2. Prepare the glass temporary protection LED curing coating according to the raw material ratios in Table 1 below.

[0047] Table 1

[0048]

[0049]

[0050] The coatings of Examples 1 to 3 and Comparative Examples 1 to 3 were coated on a standard mirror glass plate (Guangzhou Biaogeda BGD2604) with a coating amount of 10 g / m 2 (The obtained paint film thickness is generally about 10μm), after roller coating, it is leveled by far infrared for 10 seconds, and irradiated under LED light (395nm wavelength) at an energy of 1000mj / cm 2 Oxygen curing conditions.

[0051] After UV curing, the test samples were placed in a constant temperature and humidity room (temperature 21°C to 25°C, humidity 45% to 55%) for 60 minutes to stabilize the state of the test samples. Various performance tests were performed on Examples 1 to 3 and Comparative Examples 1 to 3 (all results were measured in a constant temperature and humidity laboratory). The performance test methods are shown in Table 2.

[0052] Table 2

[0053] project index Test Method Remark Pencil hardness (Mitsubishi) On request GB / T6739-1996 Trolley-type pencil hardness tester (the higher the hardness, the better) Cutting fluid resistance On request soak The paint film is intact and does not fall off for more than 120 minutes Adhesion ≤1 level GB / T9268-1998 Grid knife (3M tape) Alkaline bubble shedding On request 5% NaOH\60℃ soak Overall shedding in less than 1 minute (stopwatch)

[0054] Table 3

[0055]

[0056] The anhydride-modified polyurethane multifunctional acrylate in the present invention can give the paint film strong hardness and scratch resistance. This resin has a reasonable 4-ethoxy structure through effective structural design, so as to achieve reasonable hydrophilicity (excessive hydrophilicity is not resistant to cutting fluid, and it is also necessary to consider that the film is easy to fade in the later stage), and the terminal dicarboxyl structure is designed, which can react quickly in alkaline water, destroy the paint film structure, and facilitate film fading; the introduction of PEG200DA (polyethylene glycol diacrylate) long-chain monomer increases the flexibility of the paint film, reduces the shrinkage of UV curing, and increases the adhesion. In addition, the introduction of ethoxylated groups makes it easier to fall off when soaked in alkaline water; the synergistic addition of monofunctional monomers DMAA and ACMO can not only improve the LED photopolymerization activity of the overall coating, but also utilize the hydrophilic properties of the two to make it easier to fall off when soaked in alkaline water. The synergistic addition of methacrylic acid phosphate and 3-methacryloxypropyl trimethoxysilane improves the adhesion of the coating on the glass, making the incision protection paint film less likely to collapse during processing; the selected 2,4,6-trimethylbenzoyl-diphenylphosphine oxide TPO has relatively strong absorption near the wavelength of 395nm, is the most representative LED photoinitiator, has high initiation efficiency, and does not yellow. By comparison, the comprehensive performance of Examples 1 to 3 of the present invention is better than that of Comparative Examples 1 to 3, especially Example 2 shows the best comprehensive performance.

[0057] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A glass temporary protection UV coating, characterized in that: Contains the following raw materials in parts by weight: 50-70 parts of anhydride modified polyurethane multifunctional acrylate; UV active monomer - 10-30 parts; UV active monomer 2 10-25 parts; 1-3 parts of methacrylate phosphate; 1 to 3 parts of silane coupling agent; 3-5 parts of photoinitiator; 0.3 to 1 part of leveling agent.

2. The glass temporary protection UV coating according to claim 1, characterized in that: It is made of the following raw materials in parts by weight: 50-70 parts of anhydride modified polyurethane multifunctional acrylate; UV active monomer - 10-30 parts; UV active monomer 2 10-25 parts; 1 part of methacrylate phosphate; 1 part of silane coupling agent; 3-5 parts of photoinitiator; 0.3 parts of leveling agent.

3. A glass temporary protection LED curing coating according to claim 1 or 2, characterized in that: The anhydride-modified polyurethane multifunctional acrylate has the structure shown below: n≥0。 4. The glass temporary protection LED curing coating according to claim 3, characterized in that: The preparation method of the anhydride-modified polyurethane multifunctional acrylate comprises the following steps: (1) adding isophorone diisocyanate, dibutyltin dilaurate as a catalyst, and p-hydroxyanisole as a polymerization inhibitor to pentaerythritol triacrylate, reacting at 80-90° C., and obtaining the first step intermediate product A when NCO reaches a theoretical value; (2) The intermediate product A obtained in the first step is cooled to 40-50° C., tetraethylene glycol is added, and dibutyltin dilaurate is added as a catalyst, and the reaction is carried out at 80-90° C. When the NCO theoretical value is reached, the intermediate product B in the second step is obtained; (3) The intermediate product B obtained in the second step is cooled to 40-50°C, and trimellitic anhydride is added, and triphenylphosphine is used as a catalyst. The reaction is carried out at 110-120°C and the temperature is kept constant. When the acid value reaches the theoretical value, anhydride-modified polyurethane multifunctional acrylate is obtained.

5. The glass temporary protection LED curing coating according to claim 1, characterized in that: The UV active monomer 1 is polyethylene glycol di(meth)acrylate; The second UV active monomer is one of acryloylmorpholine and dimethylacrylamide, or a combination of both.

6. The glass temporary protection LED curing coating according to claim 1, characterized in that: The methacrylate phosphate is 2-hydroxyethyl methacrylate phosphate.

7. The glass temporary protection LED curing coating according to claim 1, characterized in that: The silane coupling agent is 3-methacryloxypropyltrimethoxysilane.

8. The glass temporary protection LED curing coating according to claim 1, characterized in that: The photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

9. The glass temporary protection LED curing coating according to claim 1, characterized in that: The leveling aid is polyether modified silicone.

10. The method for preparing the glass temporary protection LED curing coating according to any one of claims 1 to 9, characterized in that: The following steps are involved: According to the formula, UV active monomer 1, UV active monomer 2, photoinitiator, methacrylate phosphate, silane coupling agent and leveling aid are added into a high-speed dispersing kettle at a speed of 800-1200 rpm and stirred. Then, anhydride-modified polyurethane multifunctional acrylate is added and stirred continuously. After uniform dispersion, vacuum degassing is performed to obtain a temporary glass protective UV coating.

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