Coating standard: gb5211.19-88 determination of relative tinting power and tinting of coloured pigments visual comparison method

Core tip: this standard is equivalent to iso787 / 16-1986 general test methods for pigments and extenders - Part 16: Determination of relative tinting power (equivalent tinting value) and diluted color - Visual comparison method 1 subject definition and scope of application This standard specifies a general test method for determining the relative tinting force and tinting of two similar pigments by visual comparison When this general method is not applicable to a specific product, a special method shall be specified to determine the Application scope and advantages of roller ceramic coating Recommended introduction: the surface of ceramic rubber plate used for roller ceramic coating is cast into durable rubber plate by hundreds of independent small ceramic pieces Each ceramic piece has raised characteristics Under general conveyor belt pressure, thousands of unique cast bumps can produce positive traction, prevent slipping and extend the service life of conveyor belt roller At the same time, the bottom layer adopts high-quality rubber, which has strong elasticity and can play a good impact resistance role The scope of application of roller ceramic coating is one three six 83857180 (the same as V) 1 Roller coating in extremely harsh working environment 2 The belt joint is not suitable for fixing with iron buckle; 3 It is suitable for leather Home of coatings: this standard is equivalent to iso787 / 16-1986 general test methods for pigments and extenders - Part 16: Determination of relative tinting power (equivalent tinting value) and diluted color - Visual comparison method 1 Subject determination and scope of application this standard specifies a general test method for the determination of relative tinting power and tinting of two similar pigments by visual comparison When this general method is not applicable to a specific product, a special method shall be specified to determine the tinting and relative tinting power of pigments 2 principle the dispersions of the sample to be tested and the standard sample are prepared under certain conditions by the automatic grinder The two dispersions and the color paste are mixed with a certain proportion of white pigment paste The color intensity and the color fading of the two diluted color pastes are compared The main factors affecting the pigment coloring power are as follows: the force exerted on the automatic grinder; the selection of the best grinding concentration of the dispersion; the best grinding revolution of the dispersion; the selection of the dilution ratio; the strict control of weighing and operation 3 materials 3.1 alkyd resin is recommended as follows: a mixture of 63% (M / M) linseed oil and 23% (M / M) phthalic anhydride, with a maximum acid value of 15 m g KOH / g, a viscosity (no solution) of 7-10 PA · s and a hydroxyl value of about 40 mg KOH / g 3.1.2 linseed oil modified by carbamate; linseed oil content is about 80%; acid value is zero; free isocyanate is zero; free hydroxyl is 0.8 ~ 1.2%; viscosity (20 ℃) is 15 ~ 18pa · s 3.2 white pigment slurry 3.2.1 the white slurry based on alkyd resin shall be composed of 40 parts of R-type titanium dioxide, 56 parts of alkyd resin and 4 parts of calcium stearate Mix the above components evenly with the adjusting knife, then grind them on the three roller mill until the fineness tested on the fineness plate is less than 15um, and store them in the airtight container, preferably the hose with screw cap 3.2.2 the white pulp with carbamate modified linseed oil as the base material shall have the following components: 40 parts of R-type titanium dioxide; 50 parts of carbamate modified linseed oil; 7 parts of calcium stearate; 3 parts of synthetic silicon dioxide Mix the above components evenly with the adjusting knife, then grind them on the three roller mill until the fineness tested on the fineness plate is less than 15um, and store them in the airtight container, preferably the hose with screw cap The above two kinds of white pulp can be selected as needed 4 Instrument automatic grinder (the diameter of frosted glass plate is 180-250mm, the force applied on the grinder is about 1kn, the rotating speed is 70-120r / min); knife adjustment (made of steel, tapered blade, the length is about 140-150 mm, the widest part is about 20-25 mm, the narrowest part is not less than 12.5 mm); glass plate (colorless and transparent, the size is about 150 mm × 150 mm); wet film maker (the gap is 50-100um) 5 Select representative samples of test pigments according to gb9285 6 determination step 6.1 determination of the best grinding conditions of pigment dispersion 6.1.1 the appropriate mass ratio of pigment and paint base depends not only on the oil absorption of pigment, but also on the viscosity of mixture during grinding operation In order to make the pigment with low paint, medium paint and high paint demand reach appropriate concentration, and to make the mixture of about 2ml in each case, the following three groups are recommended: a.3.0g pigment and 1.5g paint base; b.1.0g pigment and 1.5g paint base; c.0.5g pigment and 1.5g paint base; Note: if it is found that the selected mixture is too thick or too thin when used on the grinder, another ratio should be used 6.1.2 take 1.5g of paint base and appropriate amount of the above pigment and add 1kn force to the grinder for grinding, 50 revolutions for each time, 200 revolutions in total, take out the slurry accounting for about 1 / 4 of the total volume and store it in a proper container, and then continue to grind to 300 revolutions and 400 revolutions, respectively take out a small part of the same slurry Also store in a suitable container for use On the lower plate of the grinder, place 3 ± 0.01g white pigment slurry and the color pigment slurry that has been ground for 200 revolutions, the content of which is about 0.12g color pigment Mix the two kinds of color pastes under the action of no grinding, and then apply the minimum force Grind for 25 revolutions each time, 4 times in total Collect the pastes and place them for use In addition, weigh the same amount of 300 and 400 revolutions of color paste and 3 ± 0.01g white paste and repeat the above operations Arrange the prepared diluted color pastes on the colorless glass plate in turn, pull them down evenly with the wet film preparation device, immediately visually compare the strength of each color pastes, evaluate the color pastes showing the maximum color strength, and record the most reasonable grinding revolution of the color pastes as the best grinding revolution of the test Note: when the pigment paste containing 0.12g pigment is mixed with 3.0g white pigment paste, its dilution ratio is 1:10 In order to produce a strong wash tint to evaluate the strength and hue of the wash pastes, the ratio should be modified to 1:5 or 1:20 (for weak or strong pigments, respectively) 6.2 preparation of pigment dispersion prepare the dispersion of pigment standard sample and sample according to the conditions determined in 7.1 6.3 preparation of diluted color paste: weigh 3 ± 0.01g white paste, grind it under the minimum force according to the amount of standard pigment dispersion with the selected dilution ratio, grind it for 25 revolutions each time, 4 times in total, and the collected diluted color paste is ready for use Prepare the diluted color paste of the sample in the same way 6.4 comparison of tinting and determination of relative tinting power Arrange the two diluted color pastes prepared in 7.3 on the colorless glass plate, and pull them down with the wet film preparation device to form two opaque strips with uniform thickness of not less than 25 mm in width and not less than 40 mm in contact side length Lightly rub each color strip with a finger to compare the difference of color depth between the rubbed and non rubbed surfaces If there is obvious difference in the result, record it Continue to test the surface that has not been rubbed, and immediately compare the tinting intensity and hue of the two through the glass plate under the scattered light or artificial sunlight If the color intensity is the same and the color phase is the same, the tinting power of the tested sample is 100% However, if the tint intensity is equal and the hue is different, note that the difference in tint is in its nature If the colouring strength is different, the amount of the dispersion of the test sample shall be estimated After weighing, another dilute color paste shall be prepared according to 7.3, while the standard sample shall not be changed, and then the comparison shall be conducted until the colouring strength is equal Note: the paint base of white pulp shall be consistent with that of pigment dispersion to avoid flocculation 7 Calculate the relative colouring force x (%) of the test sample according to formula (1): x = B × 100 / a (1) of the standard sample, where a -- the mass of the sample reaching the same colouring strength as the standard, G; B -- the mass of the standard sample, G 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,