Low-odor gloss oil as well as preparation method and application thereof

Abstract

The invention relates to the technical field of printing and packaging, and particularly discloses low-odor gloss oil as well as a preparation method and application thereof. The invention discloses low-odor gloss oil, which is prepared from 30 to 36 parts of water-soluble acrylic resin, 30 to 36 parts of polyacrylate film-forming emulsion, 30 to 36 parts of polyacrylate non-film-forming emulsion, 8 to 16 parts of wax emulsion, 0.5 to 2 parts of wetting flatting agent, 0.04 to 0.08 part of defoaming agent, 8 to 12 parts of ammonia water and 27 to 33 parts of water. The polyacrylate film-forming emulsion and the polyacrylate non-film-forming emulsion are prepared by adding an oil-soluble redox system to remove residual monomers after raw materials are subjected to a synthesis reaction. The low-odor gloss oil prepared by using the technical scheme provided by the invention has excellent glossiness, and has excellent wear resistance, slip inhibition, wet adhesion resistance and water resistance.

Description

Technical Field

[0001] The present application relates to the technical field of printing and packaging, and in particular to a low-odor varnish and a preparation method and application thereof. Background Art

[0002] In the field of packaging and printing, in order to improve the glossiness of the product surface and the exquisiteness of the product itself, varnish is usually used to perform a glazing process on the product surface.

[0003] Currently, UV curing varnish and water-based varnish are commonly used. UV curing varnish is a solvent-free varnish. After being evenly applied on the surface of the product, it will undergo a polymerization reaction and rapidly solidify under the irradiation of ultraviolet light of a certain wavelength, forming a bright film layer on the surface of the product. Water-based varnish is a varnish made of water-based resin as the main agent, water as the solvent, and various additives. After being evenly applied to the surface of the product, it is heated to evaporate the water in the varnish, and the resin remains on the surface of the product to form a bright film layer. Compared with UV varnish, water-based varnish is required in more stringent fields such as food and medicine. However, water-based varnish has a certain irritating odor because the monomers remaining in the latex particles are difficult to remove and ammonia is used as a regulator, which has an adverse effect on workshop workers, especially in a closed workshop environment.

[0004] Therefore, a low-odor varnish is needed to meet market demand. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a low-odor varnish and a preparation method and application thereof.

[0006] The present application provides a low-odor varnish, specifically comprising the following components in parts by weight: 30-35 parts of water-soluble acrylic resin, 30-35 parts of polyacrylate film-forming emulsion, 30-35 parts of polyacrylate non-film-forming emulsion, 8-16 parts of wax emulsion, 0.5-2 parts of wetting and leveling agent, 0.04-0.08 parts of defoaming agent, 8-12 parts of ammonia water, and 27-33 parts of water; The polyacrylate film-forming emulsion is prepared by synthesizing an emulsifier, sodium bicarbonate, methyl methacrylate, butyl acrylate, isooctyl acrylate, and an initiator, and then adding an oil-soluble redox system to remove residual monomers. The polyacrylate non-film-forming emulsion is prepared by subjecting an emulsifier, sodium bicarbonate, methyl methacrylate, butyl acrylate and an initiator to a synthetic reaction, and then adding an oil-soluble redox system to remove residual monomers.

[0007] Preferably, the low-odor varnish specifically comprises the following components in parts by weight: 31-34 parts of water-soluble acrylic resin, 31-34 parts of polyacrylate film-forming emulsion, 31-34 parts of polyacrylate non-film-forming emulsion, 10-14 parts of wax emulsion, 1-1.5 parts of wetting and leveling agent, 0.05-0.07 parts of defoaming agent, 9-11 parts of ammonia water, and 29-31 parts of water.

[0008] Preferably, the synthesis method of the polyacrylate film-forming emulsion is: According to the formula, 0.5-0.7 parts by weight of emulsifier and 0.08-0.12 parts by weight of sodium bicarbonate are dissolved in deionized water, 1.2-1.6 parts by weight of methyl methacrylate, 0.8-1.2 parts by weight of butyl acrylate, and 1.4-1.8 parts by weight of isooctyl acrylate are added under nitrogen protection, stirred for 8-15 minutes, and 0.02-0.03 parts by weight of 0.8-1.2wt% ammonium persulfate initiator aqueous solution is slowly added dropwise to obtain a seed emulsion; 5-6 parts by weight of methyl methacrylate, 3.5-4.5 parts by weight of butyl acrylate, 6-7 parts by weight of isooctyl acrylate, and 0.18-0.22 parts by weight of methacrylic acid are continuously added dropwise to the seed emulsion, and 0.05-0.06 parts by weight of a 0.8-1.2 wt% aqueous solution of ammonium persulfate initiator is simultaneously added dropwise, and the mixture is stirred at a temperature of 80-90° C. for 50-80 min to obtain a random polyacrylate emulsion; At a temperature of 80-90° C., a redox system is added to the random polyacrylate emulsion system to continue the reaction of residual monomers, then the temperature is lowered to below 40° C., ammonia water is added to adjust the pH value to 8-9, stirred for 10-20 minutes, and filtered to obtain the polyacrylate film-forming emulsion.

[0009] Preferably, the synthesis method of the polyacrylate non-film-forming emulsion is: According to the formula, 0.5-0.7 parts by weight of emulsifier and 0.08-0.12 parts by weight of sodium bicarbonate are dissolved in deionized water, 2.0-2.4 parts by weight of methyl methacrylate and 1.6-2.0 parts by weight of butyl acrylate are added under nitrogen protection, stirred for 8-15 minutes, and 0.02-0.03 parts by weight of 0.8-1.2wt% ammonium persulfate initiator aqueous solution is slowly added dropwise to obtain a seed emulsion; 8.2-9.4 parts by weight of methyl methacrylate, 6.6-7.8 parts by weight of butyl acrylate, and 0.18-0.22 parts by weight of methacrylic acid are continuously added dropwise to the seed emulsion, and 0.05-0.06 parts by weight of a 0.8-1.2 wt% aqueous solution of ammonium persulfate initiator is simultaneously added dropwise, and the mixture is stirred at a temperature of 80-90° C. for 50-80 min to obtain a random polyacrylate emulsion; At a temperature of 80-90° C., a redox system is added to the random polyacrylate system to continue the reaction of residual monomers, then the temperature is lowered to below 40° C., ammonia water is added to adjust the pH value to 8-9, stirred for 10-20 minutes, and filtered to obtain the polyacrylate non-film-forming emulsion.

[0010] Preferably, the weight ratio of the redox system to the random polyacrylate system is 0.30-0.40:100; The redox system is composed of a mixture of an oxidant and a reductant in a weight ratio of 0.5-1:1.5-2.5; The oxidant is selected from one or more of tert-butyl hydroperoxide, tert-butyl peroctanoate, and benzoyl peroxide; The reducing agent is selected from one or more of sodium formaldehyde sulfoxylate, ferrous compounds, transition metal salts of carboxylic acids, reducing sugars, reducing sugar derivatives, sulfurous acid, and sulfoxylates.

[0011] Preferably, the weight ratio of the redox system to the random polyacrylate system is 0.50-0.60:100; The redox system is composed of a mixture of an oxidant and a reductant in a weight ratio of 0.5-1:3-4; The oxidant is selected from one or more of tert-butyl hydroperoxide, tert-butyl peroctanoate, and benzoyl peroxide; The reducing agent is selected from one or more of sodium formaldehyde sulfoxylate, ferrous compounds, transition metal salts of carboxylic acids, reducing sugars, reducing sugar derivatives, sulfurous acid, and sulfoxylates.

[0012] Preferably, the water-soluble acrylic resin is

[0013] Preferably, the wax emulsion is composed of wax emulsions having a weight ratio of 0.8-1.2:0.8-1.2 CT1806 and wax emulsion Ultralube GA 6668 are mixed.

[0014] In some specific embodiments, the wax emulsion The weight ratios of CT1806 and wax emulsion Ultralube GA6668 are 0.8:1, 0.8:1.2, 1:0.8, 1:1, 1:1.2, 1.2:0.8, and 1.2:1.

[0015] In a second aspect, the present application provides a method for preparing the above-mentioned low-odor varnish, which specifically comprises the following steps in sequence: According to the formula, weigh each raw material component separately; Pour water into a container, add water-soluble acrylic resin, then add ammonia water, stir at 300-500 rpm / min at 75-85°C until dissolved, then cool to room temperature for later use; According to the formula, pour the polyacrylate non-film-forming emulsion and the polyacrylate film-forming emulsion into the container in turn and stir evenly; Under stirring conditions, add wax emulsion in sequence and stir evenly; Under stirring conditions, add the wetting and leveling agent and stir evenly; Under stirring conditions, add water-soluble acrylic resin and stir evenly; Under stirring conditions, a defoamer is added, the pH is adjusted to 8-9 after stirring evenly, and the low-odor water-based varnish is obtained after filtering.

[0016] In a third aspect, the present application provides the application of the above-mentioned low-odor varnish in the field of packaging printing.

[0017] In summary, the technical solution of this application has the following effects: The technical solution provided in the present application adopts a post-treatment chemical method to add an oil-soluble redox initiator system to remove residual monomers after the synthesis reaction of the polyacrylate film-forming emulsion and the polyacrylate non-film-forming emulsion; the low-odor varnish prepared by mixing with the remaining components has excellent gloss, and has excellent wear resistance, anti-slip properties, anti-wet adhesion, water resistance, etc. DETAILED DESCRIPTION

[0018] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in the present application.

[0019] Water-soluble acrylic resin From BASF; wax emulsion Sourced from Onkel; wax emulsion (Ultralube GA 6668) sourced from Onkel; wetting and leveling agent (Surfynol OP-340) sourced from TEGO (Germany); defoaming agent (FOAMEX 1488) sourced from TEGO; emulsifier is composed of a mixture of sodium dodecyl sulfate and fatty alcohol polyoxyethylene ether in a weight ratio of 1:5; initiator is ammonium persulfate, sourced from Shanghai Aladdin Biochemical Technology Co., Ltd. Example

[0020] Examples 1-5 Examples 1-5 respectively provide a low-odor varnish and a preparation method thereof.

[0021] The difference between the above embodiments is that the dosage of each component in the low-odor varnish is different, as shown in Table 1.

[0022] The specific steps of the preparation method of the low-odor varnish in the above embodiment are: (1) The synthesis method of polyacrylate film-forming emulsion is: According to the formula, 0.6 parts by weight of an emulsifier (composed of a mixture of sodium lauryl sulfate and fatty alcohol polyoxyethylene ether in a weight ratio of 1:5) and 0.1 parts by weight of sodium bicarbonate are dissolved in deionized water, 1.4 parts by weight of methyl methacrylate, 1 part by weight of butyl acrylate, and 1.6 parts by weight of isooctyl acrylate are added to the monomers under nitrogen protection, stirred for 10 minutes, and 0.024 parts by weight of a 1wt% aqueous solution of ammonium persulfate initiator are slowly added dropwise to obtain a seed emulsion; 5.6 parts by weight of methyl methacrylate, 4 parts by weight of butyl acrylate, 6.4 parts by weight of isooctyl acrylate, and 0.2 parts by weight of methacrylic acid were continuously added dropwise to the seed emulsion, and 0.056 parts by weight of a 1 wt% aqueous solution of ammonium persulfate initiator was simultaneously added dropwise, and the mixture was stirred at 85° C. for 75 minutes to obtain a random polyacrylate emulsion; At a temperature of 85° C., a redox system was added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylic acid system was 0.45:100; the redox system was composed of a mixture of tert-butyl peroxide hydrogen oxidizing agent and sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 0.8:2) to continue the reaction of the residual monomers, and then the temperature was lowered to below 40° C., ammonia water was added to adjust the pH value to 8.5, stirred for 15 minutes, and filtered to obtain a polyacrylate film-forming emulsion (1 part by weight in this embodiment represents 100 g).

[0023] (2) The synthesis method of polyacrylate non-film-forming emulsion is: According to the formula, 0.6 parts by weight of emulsifier and 0.1 parts by weight of sodium bicarbonate were dissolved in deionized water, 2.2 parts by weight of methyl methacrylate and 1.8 parts by weight of butyl acrylate were added under nitrogen protection, stirred for 10 minutes, and 0.024 parts of 1wt% ammonium persulfate initiator aqueous solution were slowly added dropwise to obtain a seed emulsion; 8.8 parts by weight of methyl methacrylate, 7.2 parts by weight of butyl acrylate, and 0.2 parts by weight of methacrylic acid are continuously added dropwise to the seed emulsion, and 0.056 parts by weight of a 1 wt% aqueous solution of ammonium persulfate initiator is simultaneously added dropwise, and the mixture is stirred at a temperature of 80-90° C. for 75 minutes to obtain a random polyacrylate emulsion; At a temperature of 85° C., a redox system was added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylate system was 0.55:100; the redox system was composed of a mixture of a benzoyl peroxide oxidant and a sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 0.8:3.5) to continue the reaction of the residual monomers, and then the temperature was lowered to below 40° C., ammonia water was added to adjust the pH value to 8.5, the mixture was stirred for 15 minutes, and the polyacrylate non-film-forming emulsion was obtained by filtering.

[0024] (3) The preparation method of low-odor varnish is: According to the formula shown in Table 1, weigh each raw material component respectively; Pour water into a container, add water-soluble acrylic resin, then add ammonia water, stir at 400 rpm / min at 80°C until dissolved, then cool to room temperature for later use; According to the formula, pour the polyacrylate non-film-forming emulsion and polyacrylate film-forming emulsion into the container in turn and stir evenly; under the stirring condition of 400rpm / min, add the wax emulsion (the weight ratio of wax emulsion is 1:1) in turn. CT1806 and wax emulsion Ultralube GA 6668 are mixed and stirred evenly; Under the stirring condition of 400rpm / min, add the wetting and leveling agent and stir evenly; Under stirring condition of 400 rpm / min, add water-soluble acrylic resin and stir evenly; Under the stirring condition of 400 rpm / min, a defoamer was added, the pH was adjusted to 8-9 after stirring evenly, and a low-odor water-based varnish was obtained after filtering.

[0025] Table 1 The amount of each component in the low odor varnish in Examples 1-5 Embodiment 6-9 Examples 6-9 provide a low-odor varnish and a preparation method thereof. The difference between the above embodiment and embodiment 2 is that in the synthesis method of the polyacrylate film-forming emulsion, the amount or type of the redox system is different, as shown below.

[0026] In Example 6: Synthesis method of polyacrylate film-forming emulsion: At a temperature of 85° C., a redox system is added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylate system is 0.45:100; the redox system is composed of a mixture of tert-butyl peroctanoate oxidant and sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 0.8:2) to continue the reaction of residual monomers, and then the temperature is lowered to below 40° C., ammonia water is added to adjust the pH value to 8.5, stirred for 15 minutes, and filtered to obtain a polyacrylate film-forming emulsion.

[0027] In Example 7: Synthesis method of polyacrylate film-forming emulsion: At a temperature of 85° C., a redox system was added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylate system was 0.55:100; the redox system was composed of a mixture of tert-butyl peroxide hydrogen oxidizing agent and sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 0.8:3.5) to continue the reaction of residual monomers, and then the temperature was lowered to below 40° C., ammonia water was added to adjust the pH value to 8.5, stirred for 15 minutes, and filtered to obtain a polyacrylate film-forming emulsion.

[0028] In Example 8: In the synthesis method of polyacrylate film-forming emulsion: At a temperature of 85° C., a redox system was added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylate system was 0.30:100; the redox system was composed of a mixture of tert-butyl peroxide hydrogen oxidizing agent and sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 0.5:2.5) to continue the reaction of residual monomers, and then the temperature was lowered to below 40° C., ammonia water was added to adjust the pH value to 8.5, stirred for 15 minutes, and filtered to obtain a polyacrylate film-forming emulsion.

[0029] In Example 9: Synthesis method of polyacrylate film-forming emulsion: At a temperature of 85° C., a redox system was added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylate system was 0.40:100; the redox system was composed of a mixture of tert-butyl peroxide hydrogen oxidizing agent and sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 1:1.5) to continue the reaction of residual monomers, and then the temperature was lowered to below 40° C., ammonia water was added to adjust the pH value to 8.5, stirred for 15 minutes, and filtered to obtain a polyacrylate film-forming emulsion.

[0030] The other process parameters in the above embodiment are the same as those in embodiment 2.

[0031] Examples 10-13 Examples 10-13 provide a low-odor varnish and a preparation method thereof. The difference between the above embodiment and embodiment 2 is that in the synthesis method of the polyacrylate non-film-forming emulsion, the amount or type of the redox system is different, as shown below.

[0032] In Example 10: In the synthesis method of polyacrylate non-film-forming emulsion: At a temperature of 85° C., a redox system was added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylate system was 0.55:100; the redox system was composed of a mixture of tert-butyl peroxide hydrogen oxidizing agent and sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 0.8:3.5) to continue the reaction of residual monomers, and then the temperature was lowered to below 40° C., ammonia water was added to adjust the pH value to 8.5, stirred for 15 minutes, and filtered to obtain a polyacrylate non-film-forming emulsion.

[0033] In Example 11: Synthesis method of polyacrylate non-film-forming emulsion: At a temperature of 85° C., a redox system is added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylate system is 0.35:100; the redox system is composed of a mixture of a benzoyl peroxide oxidant and a sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 0.8:2) to continue the reaction of the residual monomers, and then the temperature is lowered to below 40° C., ammonia water is added to adjust the pH value to 8.5, the mixture is stirred for 15 minutes, and the polyacrylate non-film-forming emulsion is obtained by filtering.

[0034] In Example 12: Synthesis method of polyacrylate non-film-forming emulsion: At a temperature of 85° C., a redox system is added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylate system is 0.50:100; the redox system is composed of a mixture of a benzoyl peroxide oxidant and a sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 0.5:4) to continue the reaction of the residual monomers, and then the temperature is lowered to below 40° C., ammonia water is added to adjust the pH value to 8.5, the mixture is stirred for 15 minutes, and the polyacrylate non-film-forming emulsion is obtained by filtering.

[0035] In Example 13: Synthesis method of polyacrylate non-film-forming emulsion: At a temperature of 85° C., a redox system is added to the random polyacrylate system (the weight ratio of the redox system to the random polyacrylate system is 0.60:100; the redox system is composed of a mixture of a benzoyl peroxide oxidant and a sodium formaldehyde sulfoxylate reducing agent in a weight ratio of 1:3) to continue the reaction of the residual monomers, and then the temperature is lowered to below 40° C., ammonia water is added to adjust the pH value to 8.5, the mixture is stirred for 15 minutes, and the polyacrylate non-film-forming emulsion is obtained by filtering.

[0036] The other process parameters in the above embodiment are the same as those in embodiment 2.

[0037] Examples 14-17 Examples 14-17 respectively provide a low-odor varnish and a preparation method thereof The difference between the above embodiment and embodiment 2 is that the types of wax emulsions are different, as shown below.

[0038] In Example 14: the wax emulsion is a wax emulsion CT1806.

[0039] In Example 15: the wax emulsion is composed of a wax emulsion having a weight ratio of 2:1 CT1806 and wax emulsion Ultralube GA 6668 are mixed.

[0040] In Example 16: the wax emulsion is composed of a wax emulsion having a weight ratio of 0.8:1.8 CT1806 and wax emulsion Ultralube GA 6668 are mixed.

[0041] In Example 17: the wax emulsion is composed of a wax emulsion having a weight ratio of 1.2:0.8 CT1806 and wax emulsion Ultralube GA 6668 are mixed.

[0042] The other process parameters in the above embodiment are the same as those in embodiment 2.

[0043] Comparative Example Comparative Example 1-2 Comparative Examples 1-2 respectively provide a low-odor varnish and a preparation method thereof.

[0044] The difference between the comparative example and Example 2 is that the dosage of each component in the low-odor varnish is different, as shown in Table 1.

[0045] The other process parameters in the above comparative example are the same as those in Example 2.

[0046] Performance testing (1) Odor evaluation: After on-site evaluation by multiple people, the varnish prepared in the examples of the present application has almost no odor at all, has excellent comprehensive application performance, and is suitable for use in the fields of pharmaceutical packaging, food packaging, commercial publishing, etc.

[0047] (2) Glossiness: Use a 0# wire rod to scrape the sample and use a 60-degree gloss meter to measure the glossiness of the water-based varnish after drying. The paper is standard black and white cardboard.

[0048] (3) Abrasion resistance test: Tested according to GB / T 7706-2008 “Letterpress Decorative Printing”.

[0049] (4) Slippery: The slippery degree of water-based varnish is measured using a slip angle tester.

[0050] (5) Anti-adhesion: First, use a No. 0 wire rod to apply water-based varnish on white cardboard and dry it. Cut the white cardboard coated with water-based varnish into two 12 cm × 12 cm test samples. Then, place one of the test samples (water-based varnish side facing up) on a glass plate in an oven, and drip 0.2 mL of water on the test sample (water-based varnish side facing up); cover the other test sample (water-based varnish side facing down) on the dripping test sample (water-based varnish side facing up); place a glass plate on the test sample (water-based varnish side facing down), and place another 1 kg block on the glass plate. Finally, dry in an oven at 60°C for 60 minutes, and observe the adhesion of the two test samples.

[0051] The evaluation criteria for anti-adhesion are as follows: Excellent: The test sample slides off directly without any adhesion; Good: The test sample is sticky, and there is no paper tearing on the surface; Middle: The test sample surface is sticky and the surface is slightly torn; Poor: The test sample surface is severely adhered and the paper is torn in a large area.

[0052] (6) Water resistance: First, use a No. 0 wire rod to apply water-based varnish on white cardboard and dry it. Then, drip water on the surface coated with water-based varnish. After 30 minutes, use filter paper to absorb the water and observe the water penetration on the sample surface.

[0053] The water resistance evaluation criteria are as follows: Excellent: There is almost no water stain on the surface of the test sample; Good: Slight water stains on the surface of the test sample; Middle: obvious water stains on the surface of the test sample; Poor: The surface of the test sample is torn.

[0054] Test results: as shown in Table 2.

[0055] Table 2 Performance test results of low odor varnish in Examples and Comparative Examples Combined with Table 2, by comparing the test results of the embodiments and the comparative examples, it can be seen that the low-odor varnish prepared by the technical solution provided by the present application has a gloss of up to 55±5, a wear resistance of up to 400 times, a slip angle of 22-28, excellent resistance to wet adhesion, excellent water resistance, and excellent comprehensive application performance, and is suitable for pharmaceutical packaging, food packaging, commercial publishing and other fields.

[0056] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A low-odor varnish, characterized in that: Specifically, it includes the following components in parts by weight: 30-35 parts of water-soluble acrylic resin, 30-35 parts of polyacrylate film-forming emulsion, 30-35 parts of polyacrylate non-film-forming emulsion, 8-16 parts of wax emulsion, 0.5-2 parts of wetting and leveling agent, 0.04-0.08 parts of defoaming agent, 8-12 parts of ammonia water, and 27-33 parts of water; The polyacrylate film-forming emulsion is prepared by synthesizing an emulsifier, sodium bicarbonate, methyl methacrylate, butyl acrylate, isooctyl acrylate, and an initiator, and then adding an oil-soluble redox system to remove residual monomers. The polyacrylate non-film-forming emulsion is prepared by subjecting an emulsifier, sodium bicarbonate, methyl methacrylate, butyl acrylate and an initiator to a synthetic reaction, and then adding an oil-soluble redox system to remove residual monomers.

2. The low-odor varnish according to claim 1, characterized in that: Specifically, it includes the following components in parts by weight: 31-34 parts of water-soluble acrylic resin, 31-34 parts of polyacrylate film-forming emulsion, 31-34 parts of polyacrylate non-film-forming emulsion, 10-14 parts of wax emulsion, 1-1.5 parts of wetting and leveling agent, 0.05-0.07 parts of defoaming agent, 9-11 parts of ammonia water, and 29-31 parts of water.

3. The low-odor varnish according to claim 1, characterized in that: The synthesis method of the polyacrylate film-forming emulsion is: According to the formula, 0.5-0.7 parts by weight of emulsifier and 0.08-0.12 parts by weight of sodium bicarbonate are dissolved in deionized water, 1.2-1.6 parts by weight of methyl methacrylate, 0.8-1.2 parts by weight of butyl acrylate, and 1.4-1.8 parts by weight of isooctyl acrylate are added under nitrogen protection, stirred for 8-15 minutes, and 0.02-0.03 parts by weight of 0.8-1.2wt% ammonium persulfate initiator aqueous solution is slowly added dropwise to obtain a seed emulsion; 5-6 parts by weight of methyl methacrylate, 3.5-4.5 parts by weight of butyl acrylate, 6-7 parts by weight of isooctyl acrylate, and 0.18-0.22 parts by weight of methacrylic acid are continuously added dropwise to the seed emulsion, and 0.05-0.06 parts by weight of a 0.8-1.2 wt% aqueous solution of ammonium persulfate initiator is simultaneously added dropwise, and the mixture is stirred at a temperature of 80-90° C. for 50-80 min to obtain a random polyacrylate emulsion; At a temperature of 80-90° C., a redox system is added to the random polyacrylate emulsion system to continue the reaction of residual monomers, then the temperature is lowered to below 40° C., ammonia water is added to adjust the pH value to 8-9, stirred for 10-20 minutes, and filtered to obtain the polyacrylate film-forming emulsion.

4. The low-odor varnish according to claim 1, characterized in that: The synthesis method of the polyacrylate non-film-forming emulsion is: According to the formula, 0.5-0.7 parts by weight of emulsifier and 0.08-0.12 parts by weight of sodium bicarbonate are dissolved in deionized water, 2.0-2.4 parts by weight of methyl methacrylate and 1.6-2.0 parts by weight of butyl acrylate are added under nitrogen protection, stirred for 8-15 minutes, and 0.02-0.03 parts by weight of 0.8-1.2wt% ammonium persulfate initiator aqueous solution is slowly added dropwise to obtain a seed emulsion; 8.2-9.4 parts by weight of methyl methacrylate, 6.6-7.8 parts by weight of butyl acrylate, and 0.18-0.22 parts by weight of methacrylic acid are continuously added dropwise to the seed emulsion, and 0.05-0.06 parts by weight of a 0.8-1.2 wt% aqueous solution of ammonium persulfate initiator is simultaneously added dropwise, and the mixture is stirred at a temperature of 80-90° C. for 50-80 min to obtain a random polyacrylate emulsion; At a temperature of 80-90° C., a redox system is added to the random polyacrylate emulsion system to continue the reaction of residual monomers, then the temperature is lowered to below 40° C., ammonia water is added to adjust the pH value to 8-9, stirred for 10-20 minutes, and filtered to obtain the polyacrylate non-film-forming emulsion.

5. The low-odor varnish according to claim 3, characterized in that: The weight ratio of the redox system to the random polyacrylate system is 0.30-0.40:100; The redox system is composed of a mixture of an oxidant and a reductant in a weight ratio of 0.5-1:1.5-2.5; The oxidant is selected from one or more of tert-butyl hydroperoxide, tert-butyl peroctanoate, and benzoyl peroxide; The reducing agent is selected from one or more of sodium formaldehyde sulfoxylate, ferrous compounds, transition metal salts of carboxylic acids, reducing sugars, reducing sugar derivatives, sulfurous acid, and sulfoxylates.

6. The low-odor varnish according to claim 4, characterized in that: The weight ratio of the redox system to the random polyacrylate system is 0.50-0.60:100; The redox system is composed of a mixture of an oxidant and a reductant in a weight ratio of 0.5-1:3-4; The oxidant is selected from one or more of tert-butyl hydroperoxide, tert-butyl peroctanoate, and benzoyl peroxide; The reducing agent is selected from one or more of sodium formaldehyde sulfoxylate, ferrous compounds, transition metal salts of carboxylic acids, reducing sugars, reducing sugar derivatives, sulfurous acid, and sulfoxylates.

7. The low-odor varnish according to claim 1, characterized in that: The water-soluble acrylic resin is Joncryl®678.

8. The low-odor varnish according to claim 1, characterized in that: The wax emulsion is composed of a mixture of wax emulsion Ultralube® CT1806 and wax emulsion Ultralube GA 6668 in a weight ratio of 0.8-1.2:0.8-1.

2.

9. The method for preparing the low-odor varnish according to any one of claims 1 to 8, characterized in that: Specifically, the following steps are performed in sequence: According to the formula, weigh each raw material component separately; Pour water into a container, add water-soluble acrylic resin, then add ammonia water, stir at 300-500 rpm / min at 75-85°C until dissolved, then cool to room temperature for later use; According to the formula, pour the polyacrylate non-film-forming emulsion and the polyacrylate film-forming emulsion into the container in turn and stir evenly; Under stirring conditions, add wax emulsion in sequence and stir evenly; Under stirring conditions, add the wetting and leveling agent and stir evenly; Under stirring conditions, add water-soluble acrylic resin and stir evenly; Under stirring conditions, a defoamer is added, the pH is adjusted to 8-9 after stirring evenly, and the low-odor water-based varnish is obtained after filtering.

10. Use of the low-odor varnish according to any one of claims 1 to 8 in the field of packaging printing.

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