Coating classification: application of wollastonite in interior wall emulsion paint

Core tip: Introduction: The main component of wollastonite is CaSiO3, its theoretical composition is: Cao accounts for 48.3%, SiO2 accounts for 51.7% With special needle structure, it is helpful to improve the scrub resistance and construction performance At the same time, it has high whiteness and refractive index, high dielectric, high electrical resistance, non-magnetic, strong heat resistance, corrosion resistance, alkali resistance, low temperature chemical inertia and low oil absorption, so it has attracted much attention Wollastonite is particularly suitable for the production of white and light colored coatings Some of the pigments will change color seriously after UV irradiation, but wollastonite has good stability Latex paint Paint agent, top 10 Chinese wall paint brands Recommended introduction: interior wall paint and exterior wall paint can achieve beautiful, clean and pleasant effects, but the effects in different environments are different, so the color of the paint will be different There are ten brands of Chinese paint, ten brands of global paint, ten brands of Chinese wall paint, and ten brands of Chinese paint, Famous trademark of Chinese paint and coating In private rooms, most of us choose according to our own personality, personal hobbies and living habits The younger generation will choose the interior wall paint with rich colors and bright colors, while the older ones will have some working experience Brief introduction: the main component of wollastonite is CaSiO3, its theoretical composition is: Cao accounts for 48.3%, SiO2 accounts for 51.7% With special needle structure, it is helpful to improve the scrub resistance and construction performance At the same time, it has high whiteness and refractive index, high dielectric, high electrical resistance, non-magnetic, strong heat resistance, corrosion resistance, alkali resistance, low temperature chemical inertia and low oil absorption, so it has attracted much attention Wollastonite is particularly suitable for the production of white and light colored coatings Some of the pigments will change color seriously after UV irradiation, but wollastonite has good stability 5% titanium dioxide can be replaced by Wollastonite in latex paint and 30% - 40% titanium dioxide in water-based paint without affecting its covering power Influence of wollastonite on emulsion paint: Test Method dry covering: scrape and apply 100 μ m film on BYK chart pa-2811 paper, and test the reflectance ratio on black-and-white bottom after dry; wet covering: the minimum construction thickness of the film when the black-and-white boundary line of sheen black-and-white covering instrument can be completely covered The smaller the thickness is, the smaller the wet covering power is; the washability is; the number of times required to brush 150 μ m film (maintained for 7 days) on black film with special cleaning medium; contrast rate: refer to 5.10 contrast rate test in GB / T 9756-2009; L * a * b *: scrape 100 μ m film on BYK chart pa-2811 paper, and use portable spectrophotometer to test after it is dry Ø test results 1 The influence of wollastonite on the covering power uses nyad1250 to replace 20%, 30% and 40% titanium dioxide respectively, so as to test the influence of different substitution amounts on the covering power of the coating The formula is shown in Table 1, and the test results are shown in Table 2 According to the test results in Table 2, the viscosity of wollastonite is 3-4 Ku lower, and the same pH value is rising continuously According to the dry and wet coverage tested by two different methods, the interior wall coating with 20% and 30% alternatives has no significant reduction, while the dry and wet coverage with 40% alternatives have decreased by 3% - 4% %The value of L * a * b * did not fluctuate greatly in the three substitutions; in the washability, 20% and 30% of the substitutions did not change, but 40% of the substitutions showed excellent washability Wollastonite needle like or fiber like structure can improve the porosity of high PVC interior wall emulsion paint, and its 95% whiteness can help improve the covering power, so even if replacing 20% - 30% in the formula %The low oil absorption of wollastonite can also reduce the viscosity of the coating, and the addition of wollastonite does not affect the washability of the coating However, when the replacement amount reaches 40%, the covering power of the coating decreases seriously, but the washability is improved significantly, which shows that the wear resistance of wollastonite is better than that of the same amount of titanium dioxide According to the results of the experimental design, wollastonite can completely replace the titanium dioxide in the formula of 20% - 30%, without affecting the dry and wet coverage, and to a certain extent, it can also improve the washability of the interior wall coating 2 The influence of wollastonite on the pH value of emulsion paint under the premise of not changing the PVC and pH value of the paint, add different quality wollastonite nyad1250 in the formula, determine the reduced addition amount of amp95, so as to determine the influence of wollastonite on the pH value of the paint See Table 3 for the test formula and table 4 for the test results The pH value of the formula can be well maintained by adding wollastonite instead of amp95 At the same time, it should be noted that after accelerated storage at 50 ℃ for 7 days, the pH value of interior wall coatings with wollastonite increased in the range of 0.12-0.19, while the pH value of interior wall coatings with amp95 alone decreased However, after accelerated storage at 50 ℃ for 30 days, the pH value of both of them decreased to the same level, and they were basically in the stage of pH stability It has been fully proved by this experimental design that wollastonite can replace part of the pH regulator without affecting the pH value of the emulsion paint under the condition of not changing the PVC of the emulsion paint, because wollastonite can hydrolyze to form alkaline Ca (OH) 2 in the emulsion paint, which is of great significance to reduce the VOC of the emulsion paint What's more, after 7 days of accelerated storage, the pH value of the emulsion paint added with wollastonite shows a rising trend, which is of great significance for the initial storage of the emulsion paint It can keep the emulsion paint in the optimal flow state all the time This is mainly because in the accelerated storage process, the temperature accelerates the hydrolysis speed of wollastonite, so the pH value shows a rising trend Conclusion: wollastonite can replace 20% - 30% titanium dioxide in the interior wall latex paint system without affecting the covering and washing resistance of the paint, and can improve the pH value of the system Application prospect: with the increasing price of titanium dioxide in the whole international market since 2011, it is an urgent task for various coating enterprises to find cheaper covering filler Currently, finding titanium dioxide with lower price is the first choice for many enterprises, but wollastonite is also a new type of alternative filler that can not be ignored It can not only replace 20% - 30% of titanium dioxide, but also improve the washability of the coating, and also has the function of pH value adjustment, which has a positive development significance for the application of high-performance interior wall coating with low VOC and low odor At the same time, the needle structure of wollastonite has good cracking resistance and weather resistance Therefore, wollastonite as an important filler will be more and more used in exterior wall coating Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,