Firstly, the water-based paint formula and pigment system concentration for scientifically characterizing the application performance of titanium dioxide were determined. On this basis, the influence of titanium dioxide's tinting power, brightness and dispersion on its application performance opacity, gloss and weather resistance was systematically analyzed. , The results show that the higher the color reduction power, brightness and dispersibility of titanium dioxide, the better the gloss and hiding power of the corresponding water-based paint film, but the weather resistance has little effect.

Keywords: titanium dioxide; hiding power; decolorizing power; dispersibility

Titanium dioxide (titanium dioxide) is one of the most important white pigments. It is widely used in coatings, plastics, papermaking, inks and synthetic fibers. Among them, the amount of coatings is the largest, accounting for about 60% of the total output of titanium dioxide. Due to the late development of the titanium dioxide industry in my country, the product variety is single, most of which are general-purpose products, and its testing standards generally adopt the national standard GB/T1706-2005, which mainly focus on physical and chemical indicators and pigment performance indicators, while more downstream application manufacturers The focus is on application indicators. In the general-purpose field, the pigment performance can partially characterize the application of the product, but in the special field or high-end field, the existing titanium dioxide factory inspection system cannot fully meet the requirements of downstream users. Grasping the relationship between titanium dioxide pigment performance indicators and application performance, on the one hand, can provide help for technical marketing, on the other hand, can carry out technical work such as quality improvement based on the feedback of product application status.

In this study, first of all, by improving the existing water-based coating formulations to remove the influence of other pigment fillers such as barium sulfate and heavy calcium, the formulation can truly and objectively reflect the impact of titanium dioxide on the coating performance; and through the performance of different pigments Analyze the application performance of titanium dioxide in water-based coatings, and find out the corresponding relationship between titanium dioxide pigment performance indicators and application performance.

1 Experimental part

1.1 Main raw materials and equipment

Rutile titanium dioxide: industrial grade, Pangang Group Titanium Industry Co., Ltd.; SD-800 modified styrene-acrylic emulsion: Nantong Shengda Chemical Co., Ltd.; wetting and dispersing agent, substrate wetting agent, leveling agent, thickening agent Other additives: Shunde Sansheng Trading Company.

QPM-5 flat grinder: Guangxi Wuzhou Runxun Gem Machinery Factory; QXD scraper fineness meter: Shanghai Modern Environmental Engineering Technology Co., Ltd.; SP60 series integrating sphere spectrophotometer: American X-Rite Co., Ltd.; BYK- Gardener 60° gloss meter; Germany; SDF04 high-speed disperser: Shanghai Weida Industry and Trade Co., Ltd., wet film preparation device: Shanghai Modern Environmental Engineering Technology Co., Ltd.; Ci3000+ xenon lamp aging test chamber: American Asia Pacific.

1.2 Test method

(1) Whiteness test

According to GB/T6749-1997 "Method for Representing Paint Film Color", the L*, a*, b* coordinate system is used to represent the color of the paint film, where L* represents lightness, a* represents from red to green, and b* represents from Yellow to blue.

(2) Fineness

According to the standard of GB/T6753.1-2007 "Determination of Grinding Fineness of Paints, Varnishes and Printing Inks", a scraper fineness meter is used for testing.

(3) Hiding power

Take a small amount of paint and place it on a flat, clean polyester film, use a 100 μm thick wet mill to quickly scrape the blade, and dry naturally

For 48 h, read the color value of the polyester film on the blackboard and white board with a colorimeter to obtain the opacity value. The higher the opacity value, the better the opacity.

(4) Weather resistance

According to the national standard GB/T1865-2009 "Artificial weathering of paints and varnishes and xenon arc radiation filtered by artificial radiation exposure", the aging is carried out to detect the gloss before and after aging.