Talking about the formula of waterborne coating oil and its performance

Glossing is almost an indispensable processing step in modern packaging printing. Printing gloss can enhance the gloss of the ink, increase the heat resistance and moisture resistance of the ink layer, and play a role in protecting the printed and beautifying packaging products. Water-based printing coating is not only low-cost, simple and easy to operate, but also has the advantages of high transparency, high abrasion resistance, fast film formation, rapid drying, non-toxic and tasteless compared to other coating oils. Has been widely used.

This article mainly through a series of experiments to explore the reasonable formula of high gloss waterborne varnish, in order to improve the decorative effect of waterborne varnish, but also to ensure that waterborne varnish has good water resistance, friction resistance and other Resistance to resistance, and performance testing of Varnish formulated Varnish, and analysis of test results.

1, test materials

Acrylic resin: HR-2007 Lauter International Co., Ltd. (China, Tianjin)

L-630 Tianjin Lilong Fine Chemical Co., Ltd.

Acrylic emulsion: Omnicryl-1830 Lauter International Limited (China, Tianjin)

L-631 Tianjin Lilong Fine Chemical Co., Ltd.

Wax Dispersion System: Flexonic-600 Lauter International Limited (China, Tianjin)

Others: isopropyl alcohol, sodium carboxymethyl cellulose, tributyl phosphate, 28% ammonia, water, etc.

2, test formula

3, the test process

1) Dissolution process of HR-2007 resin solution

The resin is crushed into a fine powder, the resin powder is white, then the powder is poured into the container by the amount, and all the water is added to the container and stirred until it becomes a paste. In order to make the paste liquid not too thick, you can first use ammonia to adjust the pH of the water to about 10, or after pouring the water into the container, add a small amount of ammonia to stir for about 1.5 hours, remove the resin solution and wait.

2) Preparation of Varnishes

The 0# formula requires that the thickener is first dissolved in water to form a colorless, transparent thick and sticky liquid, and then the other raw materials are poured into the container, stirred for 1 to 1.5 hours, and finally the impurities are filtered out using a 100 mesh filter. , complete the entire process. When formulating 1#, 2#, and 3# formulas, it is only necessary to pour all the raw materials into the container and stir on the stirrer for 1 to 1.5 hours. Then remove the impurities with a 100 mesh filter. The water-based coating just removed from the mixer should contain a considerable amount of fine air bubbles, but all air bubbles can be substantially eliminated by placing them for 24 hours.

4, test results and analysis

1) Test results

For the four formulations of waterborne oil pH value, solid content, viscosity, gloss, water resistance and other performance indicators were tested, the results are shown in Table 5.

2) Test analysis and conclusion

Gloss: It can be seen from Table 5 that 2# Varnish is the highest gloss formula, and 3# is the worst one. In fact, 0# is affected by the thickener so that the gloss is lower than 2#. When no thickener is added, its gloss is similar to 2#, and the viscosity is about 0.050Pa·s, which is also similar to 2#. From the results of 0# and 1#, it can be seen that the proportion of the resin liquid and the resin emulsion has a certain influence on the gloss. Increasing the proportion of the resin liquid can effectively increase the gloss of the aqueous coating oil and increase the resin emulsion. The proportion is the opposite. In addition, different resin structures also have a certain influence on glossiness. It can be said that the choice of resin has a decisive influence.

Water resistance: It can be seen from the water resistance of 0#, 1#, and 2# coating oil that the ratio of resin liquid to resin emulsion has a certain influence on the water resistance of coating oil. Increasing the proportion of resin emulsion can improve the water resistance. Varnish water resistance, and increase the proportion of resin liquid is the opposite effect.

Evaluation of comprehensive indicators: As can be seen from Table 5, 0# Varnish is a very good Varnish for various properties, but from the economic point of view, due to the higher price of Laureate International Co., Ltd. resin emulsion, so the cost High; while 2# Polishing Oil is similar to 0# in glossiness, only slightly inferior in water resistance to 0# Polishing Oil, but the resin emulsion of Tianjin Lilong Co., Ltd., which is much lower in price, is used, so the cost is higher than 0# is much lower. In addition, Lauter International Co., Ltd.'s solid resin prices and resin emulsions are similar, but the resin liquid during the formulation process adds a lot of water, so the cost of the resin liquid is also much lower than the resin emulsion, increasing the amount of resin liquid is also reducing costs An effective means. The price to pay for this is a relatively low gloss, but a low gloss requirement and a low cost varnish are more suitable. 3# waterborne varnish is an unsuccessful experimental product in terms of its performance.

Source: 21st Century Fine Chemicals Network