Coating standard: gb5211.6-85 determination of acid resistance of pigments

Core tip: this standard is a general test method for pigments to determine the acid resistance of pigments 1 Definition When the pigment contacts with acid solution, due to the action of pigment and acid, the color of acid solution will be stained and the color of pigment itself will be changed The acid resistance of pigment refers to the ability of pigment to resist the action of acid and cause the color of acid solution and the color change of pigment 2 Hydrochloric acid (gb622): 2% solution; balance (sensitivity 0.001g); test tube (capacity 25ml, with grinding plug); electric oscillator (oscillation frequency 280 ± 5 times / min, oscillation amplitude 40 ± 2m Paint knowledge | precautions for wall paint color selection Recommended introduction: when painting the wall, the owner sometimes has difficulty in choosing what color of the wall paint to paint In fact, there is no ugly color in the wall paint, only the disharmonious color matching The use of wall color contains the knowledge of health Too strong color will stimulate people's perception, make people have a sense of fidgety, affect people's mental health Grasp the basic principles of wall color and paint a colorful space 1、 Wall paint color selection notice 1 Light color is generally used for the top surface Light colors make people feel light, dark colors make people feel heavy Usually, the treatment of rooms is from top to bottom, from shallow to deep For example, the ceiling and walls of rooms are white and Home of coatings: this standard is a general test method for pigments to determine the acid resistance of pigments 1 It is defined that the color of acid solution and the color change of pigment itself will be caused by the action of pigment and acid after the contact of pigment and acid solution The acid resistance of pigment refers to the property that pigment can resist the action of acid and cause the color change of acid solution and pigment 2 materials and equipment Hydrochloric acid (gb622): 2% solution; balance (sensitivity 0.001g); test tube (capacity 25ml, with grinding plug); electric oscillator (oscillation frequency 280 ± 5 times / min, oscillation amplitude 40 ± 2mm); filter paper (slow speed, gb1915); fine hole crucible (capacity 25ml); suction filtration bottle (capacity 125ml); cuvette (thickness 0.5cm, height 6.4cm); color comparison frame (color comparison frame should have two holes, just right Insert two cuvettes with white background; use gb251-84 and gb250-84 grey grading cards 3 Two parallel tests are required for the determination step 3.1 preparation of test solution and filter cake Weigh two samples of pigment, 0.5g each, accurate to 0.001g, and put them into two test tubes respectively, one of which is added with 20ml distilled water, the other is added with 20ml hydrochloric acid solution, put them for 5min, cover the grinding plug tightly, fix them horizontally on the electric oscillator, shake them for 5min, take them off, pour them into the fine hole crucible laid with three layers of filter paper, vacuum filter until the clear filtrate is obtained 3.2 evaluation of color change grade 3.2.1 fill the cuvette with 2% hydrochloric acid solution and the clear filtrate respectively, put two cuvettes into the cuvette hole respectively, under the North natural light, the incident light and the observed object form a 45 ° angle, the observation direction is perpendicular to the surface of the observed object, and contrast the color gray grading card to visually evaluate the color level of the filtrate 3.2.2 take out the filter cake from the two crucibles after filtration, put it on the white porcelain plate, press on the colorless glass, and use the same method as 3.2.1 to control the fading grey grading card to visually assess the color change level of the pigment 3.3 the parallel test results shall be of the same level The results showed that the acid resistance of the pigment was expressed by the staining grade of the filtrate, the discoloration grade of the filter cake, or both the staining grade of the filtrate and the discoloration grade of the filter cake When the filtrate is stained, the best discoloration of filter cake is grade 5, and the worst discoloration is grade 1 The staining degree of filtrate is between the two grades, which is indicated by 4-5, 3-4, 2-3 and 1-2 The discoloration degree of filter cake is between the two levels, which is indicated by 4 / 5, 3 / 4, 2 / 3 and 1 / 2 If it also indicates the degree of staining of filtrate and the degree of discoloration of filter cake, it means a [b], a means the degree of staining of filtrate, and [b] means the degree of discoloration of filter cake Note: for example, if the stickiness of a certain pigment filtrate is grade 5 and the color change is 4 / 5, it means 5 [4 / 5] 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,