GB/T 5211.19-1988 Determination of relative tinting strength and dilution color of coloring pigments - Visual comparison method GB/T5211.19-1988 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of relative tinting strength and colour on teduction of coloured pigments--Visual comparison method
This standard is equivalent to ISO787/161986 "General test methods for pigments and extenders--Determination of relative tinting strength (or equivalent tinting value) and teduction of colour--Visual comparison method".
UDC 667.622:667
GB 5211.19-88
Replaces GB 1708-79
Part 16: Colouring pigmentswwW.bzxz.Net
This standard specifies the general test method for determining the relative tinting strength and teduction of two similar colouring pigments by visual comparison. When this general method is not applicable to a particular product, a special method should be specified to determine the diluted color and relative tinting strength of the pigment. 2 Reference standard GB9285 Sampling of raw materials for paints and varnishes 3 Principle The dispersions of the sample and the standard sample are prepared by an automatic grinder under certain conditions. The color pastes of the two dispersions are mixed with a certain proportion of the pigment paste. The two diluted color pastes composed are compared for tinting strength and diluted color. The main factors affecting the tinting strength of the pigment are as follows: the force applied by the automatic grinder; the selection of the best grinding concentration of the dispersion; the maximum grinding revolutions of the dispersion; the selection of the dilution ratio; 4 Strict control of material weight and operation.
4.1 Paint base
The following two paint bases are recommended:
4.1.1 Alkyd resin: A mixture based on 63″° (m, m) tar and 23% (m/m) phthalic anhydride, which should meet the following requirements:
Acid value maximum 15mgKOH-gt
Viscosity (solvent-free)
7 ~10Pas :
Hydroxy value is about 40mgKOHg.
4.1.2 Urethane modified linseed oil: should meet the following requirements: linseed oil content is about 80,
acid zero;
free isoroic acid
approved by the Ministry of Chemical Industry of the People's Republic of China on November 9, 1988 1222
implemented on April 1, 1989
free hydroxyl 0.8%~1.2%
viscosity (20℃)
4.2 White pigment paste
15~18Pa's
GB 5211.19--88
4.2.1 White paste based on alkyd resin shall have the following composition: a. 40 parts by mass of R-type titanium dioxide,
b. 56 parts by mass of alkyd resin (4.1.1), 4 parts by mass of calcium stearate.
Use a spatula to evenly mix the above components, then grind on a three-roll mill until the fineness measured on the fineness plate is less than 15um, and store in an airtight container, preferably a hose with a screw cap. 4.2.2 Based on urethane-modified linseed oil White paste should have the following composition: 40 parts by mass of R-type titanium dioxide;
50 parts by mass of urethane-modified linseed oil (4.1.2), b.
7 parts by mass of calcium stearate;
d. 3 parts by mass of synthetic silicon dioxide.
Use a spatula to evenly mix the above components, then grind on a three-stage mill until the fineness tested on the fineness plate is less than 15μm, and store in an airtight container, preferably a hose with a screw cap. The above two white pastes can be selected as needed. 5 Instruments|| tt||5.1 Automatic grinding machine: The diameter of the frosted glass plate is 180~250mm, the force applied to the grinding machine is about 1kN, and the speed is 70~120r/min. 5.2 Adjusting knife: Made of steel, with a conical blade, about 140~150mm long, about 20~25mm at the widest point, and not less than 12.5mm at the narrowest point. 5.3 Glass plate: Colorless and transparent, with a size of about 150mm×150mm. 5.4 Wet film preparation device: The gap is 50~100μm. 6 Sampling
Select the test pigment according to the provisions of GB9285 7 Test Procedure
7.1 Establishment of the Optimum Grinding Conditions for Pigment Dispersion 7.1.1 Grinding Concentration of Pigment Dispersion
The appropriate mass ratio of pigment to binder depends not only on the oil absorption of the pigment but also on the viscosity of the mixture during the grinding operation. In order to achieve the appropriate concentration of pigment for low, medium and high paint requirements, and to give about 2 mL of mixture in each case, the following three groups of amounts are recommended:
a. 3.0 g pigment and 1.5 g binder,
b. 1.0 g pigment and 1.5 g binder,
c. 0.5 g pigment and 1.5 g binder.
Note: If the selected mixture is found to be too thick or too thin when used on the grinder, another ratio should be used. 7.1.2 Grinding number of pigment dispersions
Weigh 1.5g of paint base and the above appropriate amount of pigments on a grinder with a force of 1kN for grinding, 50 turns per pass, a total of 200 turns, take out a slurry accounting for about 1/4 of the total volume and store it in a suitable container, then continue grinding to 300 and 400 turns, take out a small portion of the same slurry as above. Store it in a suitable container and set aside. Instructions for use:
1ISO787/16 Grind to 5μm.
GB 5211.19-88
On the lower plate of the grinder, place 3±0.01g of white pigment slurry (4.2) and the color pigment slurry that has been ground for 200 turns, containing about 0.12g of color pigment (see note). Mix the two color slurries without grinding, then apply minimum force, grind for 25 turns per pass, a total of 4 passes, collect the slurry and set aside. Weigh the same amount of color paste ground for 300 and 400 revolutions and 3.0 ± 0.01 g of white paste and repeat the above operation. Arrange these prepared diluted color pastes on a colorless glass plate in sequence and pull them down evenly with a wet film maker. Immediately visually compare the intensity of each color paste, evaluate the color paste showing the maximum color intensity, and record the most reasonable grinding revolution for the color paste as the optimal grinding revolution for the test. Note: When the colored pigment paste containing 0.12 g of colored pigment is mixed with 3.0 g of white pigment paste, its dilution ratio is 1:10. In order to produce a strong diluted color suitable for evaluating the intensity and hue of the diluted color paste, the ratio should be corrected to 1:5 or 1:20 (suitable for weak pigments or strong pigments, respectively) 7.2 Preparation of pigment dispersions
Prepare the dispersions of the pigment standards and test samples according to the conditions determined in 7.1. 7.3 Preparation of diluted color paste
Weigh 3.0±0.01g of white paste and grind it according to the amount of standard pigment dispersion (7.2) with the selected dilution ratio under minimum force. Grind it 25 times each time for a total of 4 times. Collect the diluted color paste for later use. Prepare the diluted color paste of the sample in the same way. 7.4 Comparison of diluted color and determination of relative tinting strength Arrange the two diluted color pastes prepared in 7.3 on a colorless glass plate (5.3). Use a wet film preparation device (5.4) to pull them down to form two uniform thickness opaque strips with a width of not less than 25mm and a contact side length of not less than 40mm. Use a finger to gently rub each color strip. Compare the difference in color depth between the rubbed and unrubbed surfaces. If there is a significant difference in the results, record it. Continue to test the unrubbed surface and immediately compare the tinting strength and hue of the two through the glass plate under scattered light or artificial daylight. If the color strength is equal and the hue is the same, the diluted color is the same and the relative tinting strength of the test sample is 100%. However, if the tinting strength is equal but the hue is different, the difference in the diluted color and its nature shall be noted. If the tinting strength is different, the amount of the test sample dispersion shall be estimated, weighed and another diluted color paste shall be prepared according to 7.3, while the standard sample remains unchanged, and the comparison shall be made until the tinting strength is equal. Note: The paint base of the paste should be consistent with the paint base of the pigment dispersion to avoid condensation. 8 Expression of results 1) The relative tinting strength of the test sample is calculated using the following formula: b×100=%
|||||||||||||||||||||||| Formula for standard sample: α—Mass of the sample to achieve the same tinting strength as the standard, gbMass of the standard sample, g.
9 Test Report
The test report shall at least include the following contents: a.
Type and name of the tested product and standard sample; b.
Grinding concentration and number of revolutions used to prepare the color pigment dispersion; c.
Dilution ratio used to prepare the diluted color paste; d.
Evaluate the test film under diffuse light or artificial daylight, e.
Test results expressed as in Chapter 8 and note the hue difference, f.
Differences from the operation specified in this test,
Test date.
Instructions for use
1]1S078716 The results are expressed as relative tinting strength and equivalent tinting value. 1224
Additional instructions:
GB5211.19-88
This standard is under the jurisdiction of the National Technical Committee for Standardization of Paints and Pigments. This standard was drafted by the Shanghai Dye Industry Research Institute. The main drafter of this standard is Tan Guifen.
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