Water-based gloss oil, preparation method thereof and packaging paper

Abstract

The invention discloses water-based gloss oil, a preparation method thereof and packaging paper. The water-based gloss oil is prepared from the following raw materials in parts by mass: 30-50 parts of acrylic varnish, 3-5 parts of high-density polyethylene wax, 3-5 parts of polyethylene glycol, 3-5 parts of an anti-scraping agent, 0.01-1 part of wax emulsion, 0.1-1 part of a defoaming agent, 1-5 parts of a wetting agent, 5-10 parts of methyl ether, 20-30 parts of alcohol and 10-20 parts of deionized water. The packaging paper is prepared by coating water-based gloss oil on raw paper and drying the raw paper, the raw paper is 15-25g / m < 2 >, and the coating weight of the water-based gloss oil is 5g / m < 2 >. When the water-based gloss oil is dried, the VOC emission is low, and the prepared packaging paper has good scratch resistance, water resistance and yellowing resistance.

Description

Technical Field

[0001] The present invention relates to the field of wrapping paper, and particularly to an aqueous varnish, a preparation method thereof, and a wrapping paper. Background Art

[0002] In the traditional wrapping paper coating process, the varnish solvent system mainly uses an oil-based solvent as a dilution carrier. Such solvents are usually based on mineral oil or synthetic esters and have excellent wettability and leveling properties, which can effectively adjust the viscosity of the varnish and improve its application performance. The oil-based solvent molecules have a high compatibility with the varnish resin and can form a uniform and stable coating solution, ensuring that the varnish forms a continuous and dense protective film on the paper surface, thereby enhancing the abrasion resistance and gloss of the printed matter. However, the volatile organic compound (VOC) content of the oil-based solvent is relatively high, which does not meet the requirements of green and low-carbon sustainable development in terms of environmental protection and safety.

[0003] To solve the above problems, there has also appeared a varnish using an aqueous solvent as a dilution carrier in the prior art. For example, Chinese Patent with Publication No. CN103483907A discloses an aqueous varnish for cigarette tipping paper, which includes the following components: pure acrylic resin, wetting and dispersing agent, water, alcohol, defoaming agent, and surfactant. The above varnish produces less volatile organic compounds during drying. Since the main film-forming agent of the varnish is pure acrylic resin, coating on the base paper will improve the water resistance, but its scratch resistance is not good.

[0004] In view of this, the present invention provides an aqueous varnish, a preparation method thereof, and a wrapping paper to solve the above problems. Summary of the Invention

[0005] To overcome the above-mentioned deficiencies of the prior art, the present invention provides an aqueous varnish with low VOC emissions during drying, and the wrapping paper prepared therefrom has good scratch resistance, water resistance, and yellowing resistance.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] An aqueous varnish, comprising the following raw materials in parts by mass: 30 - 50 parts of acrylic varnish, 3 - 5 parts of high-density polyethylene wax, 3 - 5 parts of polyethylene glycol, 3 - 5 parts of scratch-resistant agent, 0.01 - 1 part of wax emulsion, 0.1 - 1 part of defoaming agent, 1 - 5 parts of wetting agent, 5 - 10 parts of methyl ether, 20 - 30 parts of alcohol, and 10 - 20 parts of deionized water.

[0008] Preferably, the density of the high-density polyethylene wax is 0.9 - 0.97 g / cm 3 , and the particle size is 1 - 10 μm.

[0009] Preferably, the scratch-resistant agent is a modified silicone compound.

[0010] Preferably, the wetting agent is at least one of Surfynol 104E, TEGO Wet 270, and BYK-346.

[0011] Preferably, the defoaming agent is at least one of TEGO Foamex 810, BYK-024, and Surfynol MD-20.

[0012] Preferably, the aqueous varnish comprises the following raw materials in parts by mass: 40 parts of acrylic varnish, 3-5 parts of high-density polyethylene wax, 3-5 parts of polyethylene glycol, 3-5 parts of scratch-resistant agent, 0.1-0.3 parts of wax emulsion, 0.1-0.3 parts of defoaming agent, 2-3 parts of wetting agent, 5-10 parts of methyl ether, 20-25 parts of alcohol, and 10-15 parts of deionized water.

[0013] To achieve the above object, the present invention further provides a method for preparing an aqueous varnish.

[0014] To achieve the above object, the present invention adopts the following technical solutions:

[0015] A method for preparing an aqueous varnish, comprising the following steps: adding acrylic varnish into a container, and then sequentially and slowly adding polyethylene glycol, ionized water, high-density polyethylene wax, wax emulsion, scratch-resistant agent, wetting agent, defoaming agent, methyl ether, and alcohol, and fully stirring and mixing during the feeding process to obtain the aqueous varnish.

[0016] To overcome the above-mentioned deficiencies of the present invention, the present invention further provides a wrapping paper, and there will be no curling or paper breakage after the ultra-thin base paper is coated with the aqueous varnish.

[0017] To achieve the above object, the present invention adopts the following technical solutions:

[0018] A wrapping paper is prepared by coating the aqueous varnish on a base paper and drying it, and the base paper is 15-25 g / m 2 , and the coating amount of the aqueous varnish is 5 g / m 2 .

[0019] Preferably, the drying temperature is 70-90 °C.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. The water-based varnish of this invention uses acrylic varnish as the primary film-forming agent, providing excellent adhesion and enhancing the flexibility and water resistance of the wrapping paper. Polyethylene glycol can adjust the film's flexibility, reducing the risk of brittle cracking. The combination of an anti-scratch agent, high-density polyethylene wax, and a wax emulsion improves the wrapping paper's wear resistance and scratch resistance. Furthermore, the high-density polyethylene wax and wax emulsion enhance the wrapping paper's smoothness, preventing even ultra-thin wrapping paper from sticking.

[0022] 2. Compared with the oil-based dilution system in the prior art, the present invention forms an aqueous dilution system by using deionized water, methyl ether, and alcohol, and adjusts the mass ratio between the components. This can avoid clogging or paper breakage and curling when applying water-based varnish, and produces less volatile organic compounds during drying, which meets the requirements of green and low-carbon production development.

[0023] 3. The present invention avoids adding amine compounds by optimizing the raw materials of water-based varnish, so that the packaging paper can resist yellowing and has good weather resistance. DETAILED DESCRIPTION

[0024] The following examples further illustrate the features of the present invention and other related features to facilitate understanding by those skilled in the art:

[0025] An embodiment of the present invention provides a water-based varnish comprising the following raw materials in parts by mass: 30 to 50 parts of acrylic varnish, 3 to 5 parts of high-density polyethylene wax, 3 to 5 parts of polyethylene glycol, 3 to 5 parts of an anti-scratch agent, 0.01 to 1 part of a wax emulsion, 0.1 to 1 part of a defoaming agent, 1 to 5 parts of a wetting agent, 5 to 10 parts of methyl ether, 20 to 30 parts of alcohol, and 10 to 20 parts of deionized water.

[0026] In some embodiments, the density of the high-density polyethylene wax is 0.9 to 0.97 g / cm 3 , particle size is 1 to 10 μm.

[0027] In some embodiments, the anti-scratch agent is a modified organosilicon compound.

[0028] In some embodiments, the wetting agent is at least one of Surfynol 104E, TEGO Wet 270, and BYK-346.

[0029] In some embodiments, the defoaming agent is at least one of TEGO Foamex 810, BYK-024, and Surfynol MD-20.

[0030] In some embodiments, the waterborne varnish comprises raw materials in the following parts by mass: 40 parts of acrylic varnish, 3 - 5 parts of high-density polyethylene wax, 3 - 5 parts of polyethylene glycol, 3 - 5 parts of scratch-resistant agent, 0.1 - 0.3 parts of wax emulsion, 0.1 - 0.3 parts of defoaming agent, 2 - 3 parts of wetting agent, 5 - 10 parts of methyl ether, 20 - 25 parts of alcohol, and 10 - 15 parts of deionized water.

[0031] An embodiment of the present invention further provides a method for preparing a waterborne varnish, comprising the following steps: adding acrylic varnish into a container, and then successively and slowly adding polyethylene glycol, ionized water, high-density polyethylene wax, wax emulsion, scratch-resistant agent, wetting agent, defoaming agent, methyl ether, and alcohol, and fully stirring and mixing throughout the feeding process to obtain the waterborne varnish.

[0032] An embodiment of the present invention also provides a wrapping paper, which is obtained by coating the waterborne varnish on a base paper and drying. The base paper is 15 - 25 g / m 2 , and the coating amount of the waterborne varnish is 5 g / m 2 .

[0033] In some embodiments, the drying temperature is 70 - 90 °C.

[0034] Example 1

[0035] A method for preparing a waterborne varnish, comprising the following steps: adding 40 g of acrylic varnish into a container, starting a stirrer, stirring at a speed of 200 - 400 rpm, and then successively and slowly adding 4.5 g of polyethylene glycol, 12 g of ionized water, 4.5 g of high-density polyethylene wax, 0.15 g of wax emulsion, 4.5 g of scratch-resistant agent (modified silicone compound), 3 g of wetting agent (Surfynol 104E), 0.3 g of defoaming agent (TEGO Foamex810), and stirring for 2 - 5 minutes each time after adding a raw material to ensure complete dispersion. Then continue to add 7.5 g of methyl ether and 23.55 g of alcohol. After that, increase the stirring speed to 800 - 1200 rpm and continue for 15 minutes to ensure uniform dispersion of wax particles and scratch-resistant agent. Finally, filter through a 300-mesh sieve to remove undispersed particles to obtain a uniform and stable waterborne varnish.

[0036] Coat the waterborne varnish on a base paper of 17 g / m 2 , and the coating amount of the waterborne varnish is 5 g / m 2 . Then dry at 80 °C to obtain a wrapping paper.

[0037] Examples 2 - 4 change the raw material formula according to Table 1 and prepare the wrapping papers of Examples 2 - 4 according to the preparation method of Example 1.

[0038] Table 1 shows the waterborne varnish formulas of Examples 1 - 3 and Comparative Examples 1 - 3

[0039]

[0040] For Examples 1 - 3 and Comparative Examples 1 - 3, the following tests were conducted on the obtained wrapping papers.

[0041] I. Determine the abrasion resistance grade of the wrapping paper according to ASTM D5264 standard.

[0042] II. Determine the number of abrasion resistance times of the wrapping paper according to ASTM D4060 standard.

[0043] III. Yellowing resistance test: After the wrapping paper is placed under UV lamp illumination for 500 hours, compare the color difference with the initial state (ΔE = 0.3 for the original wrapping paper). Contact the wrapping paper with a test paper containing 2,6 - di - tert - butyl - 4 - methylphenol (BHT) for 24 hours at a temperature of 50 °C.

[0044] IV. Observe whether paper breakage occurs in the base paper during the process of applying the water - based varnish during the coating process.

[0045] V. Observe whether the wrapping paper curls after drying.

[0046] VI. Test the slipperiness of the wrapping paper

[0047] VII. Anti - adhesion test: Stack the wrapping papers and place them in an environment of 70 °C.

[0048] Table 2 Performance test results of Examples 1 - 3 and Comparative Examples 1 - 3

[0049]

[0050] (1) The abrasion resistance performance of the wrapping papers in Examples 1 - 3 is better than that of Comparative Examples 1 - 2. This is because the combination of anti - scratch agent, high - density polyethylene wax, and wax emulsion in the water - based varnish improves the abrasion resistance and anti - scratch performance of the wrapping paper. By comparing Example 1 and Example 2, it can be seen that the content of acrylic varnish in the water - based varnish affects the abrasion resistance performance. Since acrylic varnish is a film - forming component of the water - based varnish, reducing the addition amount of acrylic varnish will affect the film - forming effect of the wrapping paper and further affect the abrasion resistance performance of the wrapping paper.

[0051] (2) The wrapping papers in Examples 1 - 3 have good yellowing resistance performance. This is because the present invention selects the raw materials of the water - based varnish by preference and avoids adding amine compounds, enabling the wrapping paper to be resistant to yellowing and having good weather resistance.

[0052] (3) In Examples 1 to 3, when applying a relatively thin base paper with aqueous varnish, since the aqueous dilution system composed of ionic water, methyl ether, and alcohol has a relatively low volatilization temperature, it can accelerate the film-forming speed of the aqueous varnish, resulting in a low paper breakage rate during coating. Further, by comparing Example 1 with Example 3, it can be seen that increasing the addition amount of acrylic varnish in the aqueous varnish will reduce the film-forming speed of the aqueous varnish and increase the paper breakage rate. Therefore, the addition amount of acrylic varnish should not be too high.

[0053] (4) The appearance of the wrapping paper in Examples 1 to 3 is flat, and there is no curling at the edges. However, the wrapping paper in Example 3 and Comparative Example 1 shows curling. This is because the volatilization speed of the aqueous dilution system is relatively slow, and the aqueous dilution system penetrates the base paper, causing the fibers on one side of the base paper to expand while there is no obvious change on the other side. During drying, the coated surface shrinks more severely, resulting in the paper curling towards the coated surface. In contrast, the volatilization speed of the aqueous dilution system of the aqueous varnish in Examples 1 to 3 is fast, reducing the curling of the base paper.

[0054] (5) The wrapping paper in Examples 1 to 3 has smoothness and anti-sticking properties, which is due to the combination of high-density polyethylene wax and wax emulsion, reducing the friction of the film-forming varnish.

[0055] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. An aqueous varnish for preparing wrapping paper, characterized in that, It comprises raw materials in the following parts by mass: 30 to 50 parts, 3 to 5 parts of high-density polyethylene wax, 3 to 5 parts of polyethylene glycol, 3 to 5 parts of anti-scratch agent, 0.01 to 1 part of wax emulsion, 0.1 to 1 part of defoamer, 1 to 5 parts of wetting agent, 5 to 10 parts of methyl ether, 20 to 30 parts of alcohol, and 10 to 20 parts of deionized water.

2. The water-based varnish according to claim 1, wherein The density of the high-density polyethylene wax is 0.9 to 0.97 g / cm 3 , and the particle size is 1 to 10 μm.

3. The waterborne varnish according to claim 1, wherein, The anti-scratch agent is a modified silicone compound.

4. An aqueous varnish according to claim 1, characterized in that, The wetting agent is at least one of Surfynol 104E, TEGO Wet 270, and BYK-346.

5. A water-based varnish according to claim 1, characterized in that, The defoamer is at least one of TEGO Foamex 810, BYK-024, and Surfynol MD-20.

6. The waterborne varnish according to claim 1, wherein, It comprises raw materials in the following parts by mass: 40 parts of acrylic varnish, 3 to 5 parts of high-density polyethylene wax, 3 to 5 parts of polyethylene glycol, 3 to 5 parts of anti-scratch agent, 0.1 to 0.3 part of wax emulsion, 0.1 to 0.3 part of defoamer, 2 to 3 parts of wetting agent, 5 to 10 parts of methyl ether, 20 to 25 parts of alcohol, and 10 to 15 parts of deionized water.

7. A method for preparing the aqueous varnish according to any one of claims 1 to 6, characterized in that, It comprises the following steps: adding acrylic varnish into a container, and then sequentially and slowly adding polyethylene glycol, ionized water, high-density polyethylene wax, wax emulsion, anti-scratch agent, wetting agent, defoamer, methyl ether, and alcohol, and fully stirring and mixing them throughout the feeding process to obtain the aqueous varnish.

8. A wrapping paper, characterized in that, It is prepared by coating the base paper with the aqueous varnish according to any one of claims 1 to 6 and drying, and the base paper is 15 to 25 g / m 2 , and the coating amount of the aqueous varnish is 5 g / m 2 .

9. A wrapping paper according to claim 8, characterized in that, The drying temperature is 70 to 90 °C.

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