High-hardness varnish capable of resisting non-woven fabric bag imprinting as well as preparation method and application of high-hardness varnish

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a high-hardness varnish capable of resisting non-woven bag imprinting and a preparation method and application of the high-hardness varnish. The varnish comprises the following components in parts by mass: main paint: 64-67 parts of modified acrylic resin, 2-5 parts of nano barium sulfate, 28-35 parts of a first solvent, 0.1-2 parts of a drier, 0.2-0.8 part of an ultraviolet light stabilizer, 0.2-0.8 part of a hindered amine stabilizer and 0.1-0.5 part of a flatting agent; and a curing agent: 90-92 parts of aliphatic polyisocyanate and 8-10 parts of a second solvent. Compared with the prior art, the invention solves the problem of bag imprint generated by a paint film in the prior art, and solves the problems of low crosslinking density and poorer leveling degree, fullness and chemical resistance of varnish using medium-low hydroxyl acrylic resin. According to the scheme, the varnish with high hydroxyl value and high hardness is provided.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and particularly relates to a high-hardness varnish resistant to non-woven bag imprinting, a preparation method thereof, and an application thereof. Background Art

[0002] In the current environment of enterprises reducing costs and increasing efficiency, in order to manufacture more competitive products, some manufacturers increase the line speed of the spraying line to increase the number of products delivered offline per unit time, thereby reducing costs and completing more orders. However, at the same time, this will also lead to a significant reduction in the baking time of the products sprayed with varnish when passing through a drying oven of a fixed length. The cross-linking reaction of the varnish is insufficient after the baking time is shortened, resulting in insufficient hardness of the paint film when offline. And some manufacturers do not set natural drying to provide time for the cross-linking reaction of the paint film, or do not have secondary baking to provide conditions for the cross-linking reaction of the paint film, resulting in insufficient curing of the paint film when the product is offline, and the cross-linking reaction in the paint film is still in progress; at this time, if it is directly packaged with a non-woven bag and transferred to the next process, the surface of the paint film will produce bag imprints when it is in close contact with the non-woven bag, and the products with bag imprints need to be further polished, re-coated or directly scrapped, which instead causes additional costs to the manufacturer.

[0003] Currently, there are varnishes prepared with acrylic resins having an OH value of 66-116 mg KOH / g (stock solution) as the main body of the main paint in the market to have the effect of resisting non-woven bag imprints under short-time baking. For example, a fast-drying varnish and a preparation method thereof disclosed in CN108977017A use a hydroxyl acrylic resin FS-3566F (OH value: 75 mg KOH / g (stock solution)) as the main resin; however, the varnish made with medium and low hydroxyl acrylic resins as the main body has a low cross-linking density, poor leveling, fullness, and chemical resistance, and cannot meet the delivery requirements of manufacturers. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-hardness varnish resistant to non-woven bag imprinting, a preparation method thereof, and an application thereof to solve at least one of the above problems, and solve the problems in the prior art that bag imprints are generated when the paint film is not fully cured and in close contact with the non-woven bag, and the varnish using medium and low hydroxyl acrylic resins as the main body of the main paint to resist non-woven bag imprints has low cross-linking density, poor leveling, fullness, and chemical resistance. This solution provides a varnish with a high hydroxyl value and high hardness to fully solve the problem that the baking time of the production line is short, while the product varnish needs a long baking time to be fully cross-linked and cured and have sufficient hardness to be used for turnover with non-woven bag packaging when offline.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The first aspect of the present invention discloses a high-hardness varnish resistant to embossing of non-woven bags, comprising the following components in parts by mass:

[0007] Main paint: 64-67 parts of modified acrylic resin, 2-5 parts of nano barium sulfate, 28-35 parts of first solvent, 0.1-2 parts of dryer, 0.2-0.8 parts of ultraviolet light stabilizer, 0.2-0.8 parts of hindered amine stabilizer, 0.1-0.5 parts of leveling agent;

[0008] Curing agent: 90-92 parts of aliphatic polyisocyanate, 8-10 parts of second solvent.

[0009] Preferably, the modified acrylic resin is from Kedinge Materials The 90-92 parts of aliphatic polyisocyanate is N 3790BA from Covestro Germany N 3790BA.

[0010] with a hydroxyl value OH of 138 and a solid content between 73% and 77%.

[0011] Preferably, the nano barium sulfate is FB-30 nano-precipitated barium sulfate from Yunfu Hongzhi New Materials.

[0012] Preferably, it includes one or both of the following:

[0013] i) The first solvent is one or more of propylene glycol methyl ether acetate, xylene, or ethyl 3-ethoxypropionate,

[0014] ii) The second solvent is butyl acetate.

[0015] Preferably, the dryer is T-12.

[0016] Preferably, it includes one or both of the following:

[0017] i) The ultraviolet light stabilizer is 1130 of BASF Tianlerong series,

[0018] ii) The hindered amine stabilizer is 292 of BASF Tianlerong series.

[0019] Preferably, the leveling agent is acrylate-modified polysiloxane.

[0020] Preferably, the leveling agent is prepared by the following method:

[0021] T1: Mix toluene and polydimethylsiloxane in a mass ratio of 2:1, and add 15 ppm of catalyst chloroplatinic acid to the mixed solution, and stir evenly;

[0022] T2: Pass in N 2Using it as a protective gas and heating it to 80 - 85°C, a mixture of ethyl acrylate, methyl acrylate, and ethylene oxide with a mass ratio of 5:5:1 was dropped into the mixed solution, stirred and reacted for 2 - 3 h;

[0023] T3: After the reaction ended, vacuum was pumped to remove the solvent and filtered to remove the catalyst, obtaining acrylate - modified polysiloxane.

[0024] The second aspect of the present invention discloses a preparation method of a high - hardness varnish resistant to non - woven bag stamping as described in any one of the above, including the following steps:

[0025] Preparing the main paint: Mixing the modified acrylic resin, nano - barium sulfate with the first solvent, and dispersing them. Subsequently, adding a drier, an ultraviolet light stabilizer, a hindered amine stabilizer, and a leveling agent, and continuing to disperse and mix to obtain the main paint;

[0026] Preparing the curing agent: Mixing aliphatic polyisocyanate with the second solvent and dispersing them to obtain the curing agent.

[0027] The third aspect of the present invention discloses an application of a high - hardness varnish resistant to non - woven bag stamping as described in any one of the above, wherein the main paint and the curing agent are mixed at a mass ratio of 100:33.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The high - hardness varnish resistant to non - woven bag stamping in this technical solution, by using the modified acrylic resin of Keding Gongcai which has high fullness, good chemical resistance, and high hardness, and is paired with the fast - drying curing agent Covestro N 3790BA, enables the varnish to have a faster cross - linking reaction rate and film hardness during short - time baking. Paired with the drier T - 12, it further accelerates the cross - linking reaction rate of the paint film, achieving the purpose of rapid drying and full curing; at the same time, nano - barium sulfate is added to the formula to enhance the surface hardness of the paint film. Due to its ultra - fine particle size and low refractive index, it can still maintain good transparency and does not affect the gloss even when added to the varnish; the self - made leveling agent acrylate - modified polysiloxane makes the coating surface have high smoothness, which can reduce the friction between the non - woven bag and the coating. Under the combined action of the modified acrylic resin, fast - drying curing agent, nano - barium sulfate, and leveling agent, this varnish can meet the requirements and achieve the purpose of being packaged with non - woven bags immediately after offline cooling. Specific Embodiments

[0030] The present invention will be described in detail below with reference to specific embodiments, but it is by no means a limitation to the present invention. The preparation means, materials, structures, or composition ratios and other features not clearly described in this technical solution are regarded as common technical features disclosed in the prior art.

[0031] In the following description:

[0032] The modified acrylic resin is the commercially available Keding Gongcai

[0033] The first solvent can be one or several of propylene glycol methyl ether acetate, xylene, and ethyl 3-ethoxypropionate; in this solution, it is particularly selected as a mixture of commercially available propylene glycol methyl ether acetate, xylene, and ethyl 3-ethoxypropionate.

[0034] The drier is the commercially available T-12 (dibutyltin dilaurate).

[0035] The ultraviolet light stabilizer is Tinuvin 1130 of the commercially available BASF Tinuvin series.

[0036] The hindered amine stabilizer is Tinuvin 292 of the commercially available BASF Tinuvin series.

[0037] The leveling agent is self-made acrylate-modified polysiloxane:

[0038] By adding 200 g of toluene, 100 g of polydimethylsiloxane, and 15 ppm of the catalyst chloroplatinic acid to a 500 mL three-necked flask, mechanically stirring evenly, introducing N 2 Protecting, slowly heating to 80 - 85 °C, gradually dropping a mixture of 50 g of ethyl acrylate, 50 g of methyl acrylate, and 10 g of ethylene oxide, stirring for 2 - 3 hours, cooling to stop the reaction, evacuating to remove the solvent, and filtering to remove the catalyst to obtain a colorless and transparent acrylate-modified polysiloxane.

[0039] The nano-barium sulfate is FB-30 high-transparency nano-precipitated barium sulfate from Yunfu Hongzhi New Materials.

[0040] The aliphatic polyisocyanate is the commercially available Covestro N 3790BA.

[0041] The second solvent of the curing agent is the commercially available butyl acetate.

[0042] A high-hardness varnish resistant to non-woven bag embossing comprises the following main paint and curing agent; among them, the component parts by mass of the main paint: 64 - 67 parts of modified acrylic resin, 2 - 5 parts of nano-barium sulfate, 28 - 35 parts of solvent, 1 - 2 parts of drier, 0.2 - 0.8 parts of ultraviolet light stabilizer, 0.2 - 0.8 parts of hindered amine stabilizer, and 0.1 - 0.5 parts of leveling agent. The component parts by mass of the curing agent: 90 - 92 parts of aliphatic polyisocyanate and 8 - 10 parts of solvent.

[0043] A preparation method of a high-hardness varnish resistant to non-woven bag stamping. Put modified acrylic resin, nano barium sulfate, and solvent into a container according to mass percentages, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Subsequently, put a drier, an ultraviolet light stabilizer, a hindered amine stabilizer, and a leveling agent into the container according to mass percentages, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Then, obtain the main paint;

[0044] Put aliphatic polyisocyanate and solvent into a container according to mass percentages, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1500 rpm. Then, obtain the curing agent;

[0045] Before the construction process, mix the main paint component and the curing agent component according to a mass ratio of 100:33 to obtain the varnish.

[0046] Example 1

[0047] A high-hardness varnish resistant to non-woven bag stamping. The base material includes the following components in parts by mass: Among them, the components of the main paint in parts by mass are: 65.5 parts of modified acrylic resin, 2 parts of nano barium sulfate, 31.5 parts of the first solvent, 0.1 part of a drier, 0.4 part of an ultraviolet light stabilizer, 0.2 part of a hindered amine stabilizer, and 0.3 part of a leveling agent acrylate-modified polysiloxane. The components of the curing agent in parts by mass are: 90 parts of aliphatic polyisocyanate and 10 parts of the second solvent.

[0048] Put modified acrylic resin, nano barium sulfate, and the first solvent into a container according to mass percentages, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Subsequently, put a drier, an ultraviolet light stabilizer, a hindered amine stabilizer, and a leveling agent into the container according to mass percentages, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Then, obtain the main paint;

[0049] Put aliphatic polyisocyanate and the second solvent into a container according to mass percentages, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1500 rpm. Then, obtain the curing agent;

[0050] Before the construction process, mix the main paint component and the curing agent component according to a mass ratio of 100:33 to obtain the varnish.

[0051] Example 2

[0052] A high-hardness varnish resistant to non-woven bag stamping. The base material comprises the following components in parts by mass: Among them, the main paint components in parts by mass are: 65.5 parts of modified acrylic resin, 3 parts of nano barium sulfate, 30.5 parts of the first solvent, 0.1 part of drier, 0.4 part of ultraviolet light stabilizer, 0.2 part of hindered amine stabilizer, and 0.3 part of leveling agent acrylate-modified polysiloxane. The curing agent components in parts by mass are: 92 parts of aliphatic polyisocyanate and 8 parts of the second solvent.

[0053] Put the modified acrylic resin, nano barium sulfate, and the first solvent into a container according to the mass percentage, disperse for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm, then put the drier, ultraviolet light stabilizer, hindered amine stabilizer, and leveling agent into the container according to the mass percentage, and disperse for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm, and then obtain the main paint.

[0054] Put the aliphatic polyisocyanate and the second solvent into a container according to the mass percentage, disperse for 10 - 20 minutes under the condition of a rotation speed of 1500 rpm, and then obtain the curing agent.

[0055] Mix the main paint components and the curing agent components in a mass ratio of 100:33 before the construction process to obtain the varnish.

[0056] Example 3

[0057] A high-hardness varnish resistant to non-woven bag stamping. The base material comprises the following components in parts by mass: Among them, the main paint components in parts by mass are: 64 parts of modified acrylic resin, 3 parts of nano barium sulfate, 32 parts of the first solvent, 0.1 part of drier, 0.4 part of ultraviolet light stabilizer, 0.2 part of hindered amine stabilizer, and 0.3 part of leveling agent acrylate-modified polysiloxane. The curing agent components in parts by mass are: 92 parts of aliphatic polyisocyanate and 8 parts of the second solvent.

[0058] Put the modified acrylic resin, nano barium sulfate, and the first solvent into a container according to the mass percentage, disperse for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm, then put the drier, ultraviolet light stabilizer, hindered amine stabilizer, and leveling agent into the container according to the mass percentage, and disperse for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm, and then obtain the main paint.

[0059] Put the aliphatic polyisocyanate and the second solvent into a container according to the mass percentage, disperse for 10 - 20 minutes under the condition of a rotation speed of 1500 rpm, and then obtain the curing agent.

[0060] Mix the main paint components and the curing agent components in a mass ratio of 100:33 before the construction process to obtain the varnish.

[0061] Comparative Example 1:

[0062] The difference between this comparative example and Example 1 is that the resin used is ZENECA SETALUX 1753SS-70, with a solid content between 70% ± 2 and a hydroxyl content of 4.2%. It has excellent appearance, fast drying, fullness, high gloss, high weather resistance and chemical resistance.

[0063] Among them, the components in parts by mass of the main paint: 70 parts of ZENECA SETALUX 1753SS-70 resin (the amount of resin used in this comparative example is different from that in Example 1 to ensure the same solid content of the main paint resin), 2 parts of nano barium sulfate, 27 parts of the first solvent (the amount of solvent used in this comparative example is different from that in Example 1 due to the different solid content of ZENECA SETALUX 1753SS-70 resin and the change in the amount of solvent caused by different solid contents does not affect the performance comparison of the formulation), 0.1 part of drier, 0.4 part of ultraviolet light stabilizer, 0.2 part of hindered amine stabilizer, and 0.3 part of leveling agent acrylate modified polysiloxane. The components in parts by mass of the curing agent: 90 parts of aliphatic polyisocyanate and 10 parts of the second solvent.

[0064] Put ZENECA acrylic SETALUX 1753SS-70 resin, nano barium sulfate, and the first solvent into a container according to the mass percentage, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Then put the drier, ultraviolet light stabilizer, hindered amine stabilizer, and leveling agent into the container according to the mass percentage, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Then the main paint is obtained;

[0065] Put aliphatic polyisocyanate and the second solvent into a container according to the mass percentage, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1500 rpm. Then the curing agent is obtained;

[0066] Before the construction process, mix the main paint component and the curing agent component in a mass ratio of 100:33 to obtain the varnish.

[0067] Comparative Example 2:

[0068] The difference between this comparative example and Example 1 is that the addition amount of nano barium sulfate is 0.

[0069] Among them, the components in parts by mass of the main paint: 65.5 parts of modified acrylic resin, 33.5 parts of the first solvent, 0.1 part of drier, 0.4 part of ultraviolet light stabilizer, 0.2 part of hindered amine stabilizer, and 0.3 part of leveling agent acrylate modified polysiloxane. The components in parts by mass of the curing agent: 90 parts of aliphatic polyisocyanate and 10 parts of the second solvent.

[0070] Put the modified acrylic resin and the first solvent into a container by mass percentage, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Subsequently, put the drier, ultraviolet light stabilizer, hindered amine stabilizer, and leveling agent into the container by mass percentage, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Then, the main paint is obtained.

[0071] Put the aliphatic polyisocyanate and the second solvent into a container by mass percentage, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1500 rpm. Then, the curing agent is obtained.

[0072] Mix the main paint component and the curing agent component in a mass ratio of 100:33 before the construction process to obtain the varnish.

[0073] Comparative Example 3

[0074] The difference between this comparative example and Example 1 is that 0.3 parts of the leveling agent TEGO100 is used.

[0075] Among them, the mass parts of the main paint components are: 65.5 parts of modified acrylic resin, 2 parts of nano barium sulfate, 31.5 parts of the first solvent, 0.1 part of drier, 0.4 part of ultraviolet light stabilizer, 0.2 part of hindered amine stabilizer, and 0.3 part of TEGO100 leveling agent. The mass parts of the curing agent components are: 90 parts of aliphatic polyisocyanate and 10 parts of the second solvent.

[0076] Put the modified acrylic resin, nano barium sulfate, and the first solvent into a container by mass percentage, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Subsequently, put the drier, ultraviolet light stabilizer, hindered amine stabilizer, and leveling agent into the container by mass percentage, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1000 rpm. Then, the main paint is obtained.

[0077] Put the aliphatic polyisocyanate and the second solvent into a container by mass percentage, and disperse them for 10 - 20 minutes under the condition of a rotation speed of 1500 rpm. Then, the curing agent is obtained.

[0078] Mix the main paint component and the curing agent component in a mass ratio of 100:33 before the construction process to obtain the varnish.

[0079] Table 1 summarizes the formulation compositions of Examples 1 - 3 and Comparative Examples 1 - 3.

[0080] Table 1 Formulation Compositions of Examples 1 - 3 and Comparative Examples 1 - 3

[0081] Example 1 Example 2 Example 3 Modified acrylic resin 65.5 65.5 64 Nano barium sulfate 2 3 3 First solvent 31.5 30.5 32 Drying agent 0.1 0.1 0.1 UV light stabilizer 0.4 0.4 0.4 Hindered amine stabilizer 0.2 0.2 0.2 Leveling agent 0.3 0.3 0.3 Aliphatic polyisocyanate 90 92 92 Second solvent 10 8 8 Comparative Example 1 Comparative Example 2 Comparative Example 3 Modified acrylic resin Zahn resin 70 65.5 65.5 Nano barium sulfate 2 0 2 First solvent 27 33.5 31.5 Drying agent 0.1 0.1 0.1 UV light stabilizer 0.4 0.4 0.4 Hindered amine stabilizer 0.2 0.2 0.2 Leveling agent 0.3 0.3 Degussa 0.3 Aliphatic polyisocyanate 90 90 90 Second solvent 10 10 10

[0082] The resins prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests. The test methods are as follows, and the test results are shown in Table 2:

[0083] For acid resistance, refer to Test Method GB / T 9274-1988, Method A;

[0084] For alkali resistance, refer to Test Method GB / T 9274-1988, Method A;

[0085] For pencil hardness, refer to Test Method GB / T 6739-2006;

[0086] For printing on non-woven bag packaging, the test method is as follows: The product paint film is baked at 70°C for 40 min, 80 min, and 120 min under three different conditions. After cooling for 30 minutes, it is overlaid with a non-woven bag, and a steel block with a length and width of 20 cm × 10 cm and a weight of 1000 ± 1 g is placed on the non-woven bag. After standing for 4 h, the steel block and the non-woven bag are removed to check whether there are bag prints on the surface of the paint film.

[0087] Table 2 Performance test results of Examples 1-3 and Comparative Examples 1-3

[0088]

[0089] Table 2 shows the comparison of the performance and actual application between the examples and the comparative examples. It can be seen that the pencil hardness of Comparative Examples 1-3 after baking at 70°C for 40 min is not as high as that of Examples 1-3. After baking at 70°C for 40 min and standing for 30 min, there are no bag prints on the non-woven bag packaging of Examples 1-3, which can meet the production line requirements, while Comparative Examples 1-3 require a longer baking time to meet the packaging requirements; moreover, the formula of this solution has a higher pencil hardness.

[0090] In summary, the formula of the present invention has a high paint film hardness under the conditions of short baking time and low baking temperature to resist the imprint caused by the turnover of non-woven bag packaging immediately after the product comes off the production line, and at the same time has good chemical resistance and good light aging resistance.

[0091] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A high-hardness varnish for resisting non-woven bag embossing, characterized in that: The composition comprises the following components in parts by weight: Main paint: 64-67 parts of modified acrylic resin, 2-5 parts of nano barium sulfate, 28-35 parts of the first solvent, 0.1-2 parts of drying agent, 0.2-0.8 parts of ultraviolet light stabilizer, 0.2-0.8 parts of hindered amine stabilizer, 0.1-0.5 parts of leveling agent; Curing agent: 90-92 parts of aliphatic polyisocyanate and 8-10 parts of the second solvent.

2. The high-hardness varnish for resisting non-woven bag embossing according to claim 1, characterized in that: The modified acrylic resin is MR14898, 90-92 parts of the aliphatic polyisocyanate are from Covestro of Germany N 3790BA.

3. The high-hardness varnish for resisting non-woven bag embossing according to claim 1, characterized in that: The nano barium sulfate is FB-30 nano precipitated barium sulfate produced by Yunfu Hongzhi New Materials.

4. The high-hardness varnish for resisting non-woven bag embossing according to claim 1, characterized in that: Include one or both of the following: i) the first solvent is one or more of propylene glycol methyl ether acetate, xylene or ethyl 3-ethoxypropionate, ii) The second solvent is butyl acetate.

5. The high-hardness varnish for resisting non-woven bag embossing according to claim 1, characterized in that: The drying agent is T-12.

6. The high-hardness varnish for resisting non-woven bag embossing according to claim 1, characterized in that: Include one or both of the following: i) The ultraviolet light stabilizer is 1130 of BASF Tianlerong series, ii) The hindered amine stabilizer is 292 of BASF Tianlerong series.

7. The high-hardness varnish for resisting non-woven bag embossing according to claim 1, characterized in that: The leveling agent is acrylate modified polysiloxane.

8. The high-hardness varnish for resisting non-woven bag embossing according to claim 7, characterized in that: The leveling agent is prepared by the following method: T1: Toluene and polydimethylsiloxane were mixed in a mass ratio of 2:1, and 15 ppm of catalyst chloroplatinic acid was added to the mixed solution and stirred evenly; T2: introduce N2 as protective gas and raise the temperature to 80-85°C, add a mixture of ethyl acrylate, methyl acrylate and ethylene oxide in a mass ratio of 5:5:1 dropwise to the mixed solution, stir and react for 2-3 hours; T3: After the reaction is completed, vacuum is applied to remove the solvent and the catalyst is removed by filtration to obtain acrylate-modified polysiloxane.

9. A method for preparing a high-hardness varnish for resisting non-woven bag stamping according to any one of claims 1 to 8, characterized in that: The steps include: Preparing the main paint: mixing the modified acrylic resin, nano barium sulfate and the first solvent, and dispersing them, then adding a drying agent, an ultraviolet light stabilizer, a hindered amine stabilizer and a leveling agent, and continuing to disperse and mix to obtain the main paint; Prepare the curing agent: mix the aliphatic polyisocyanate with the second solvent and disperse them to obtain the curing agent.

10. An application of a high-hardness varnish for resisting non-woven bag embossing as claimed in any one of claims 1 to 8, characterized in that: The main paint and the curing agent are mixed in a mass ratio of 100:33.

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