Coating standard: gb1717-86 determination of pH value of pigment water suspension

Core tips: This standard specifies the general test method for the determination of pH value of pigment water suspension This standard is equivalent to the international standard iso787 / 9-1981 general test methods for pigments and extenders - Part 9: Determination of pH of water suspension Note: when this general method is applicable to designated pigments or pigments, as long as the terms referring to this method are included in the product standard of such pigments or pigments, and the changes required due to the characteristics of the products are indicated Only when this general method is not applicable to a specific product should the Paint knowledge how about Akzo Nobel Powder Coating Recommended introduction: powder coating is a kind of coating with different form from general coating, which is in powder form It is a new type of coating, because of its own advantages and more and more known by people Let's introduce Akzo Nobel Powder coating Akzo Nobel Powder coating is a cost-effective coating solution, which can be applied to different kinds of products After the treatment of static electricity and fire baking, a tough and durable coating surface will be formed, with the least impact on the environment Since the introduction of this technology, powder coating has been able to continue to maintain the Home of coatings: this standard specifies the general test method for the determination of pH value of pigment aqueous suspension This standard is equivalent to the international standard iso787 / 9-1981 general test methods for pigments and extenders - Part 9: Determination of pH of water suspension Note: when this general method is applicable to designated pigments or pigments, as long as the terms referring to this method are included in the product standard of such pigments or pigments, and the changes required due to the characteristics of the products are indicated Only when this general method is not applicable to a specific product, a special method shall be specified to determine the pH value of water suspension 1 reagent fresh distilled water or water of at least the same purity prepared by other methods Boil the water in a chemical resistant glass container for 5-10min, cool it, and protect the cooled water with an alkali asbestos pipe or similar device to avoid contact with the air It should be used immediately, and the storage time should not exceed 30min 2 instrument glass container (volume 50ml, made of chemical resistant glass, with ground glass plug or rubber plug Before the first use of the container, it must be soaked in boiling dilute hydrochloric acid, and then fully washed with distilled water; pH measuring device (capable of measuring to 0.1 unit, and calibrated with buffer solution with known pH value under the test temperature); balance (accurate to 0.01g or higher) 3 The determination step is to conduct parallel test of two samples at room temperature In a glass container, prepare a 10% (M / M) pigment suspension with distilled water (Chapter 1), plug the container, shake it vigorously for 1min, then leave it for 5min, remove the plug, and determine the pH value of the suspension, accurate to 0.1 unit If the pigment is easily dispersed in water, a wetting agent may be used When the pigment is insoluble in ethanol, anhydrous ethanol can be used as the wetting agent, and the dosage should be as small as possible, with a maximum of 5ml When the pigment is soluble in ethanol, a neutral non-ionic wetting agent can be used For example, if 10ml 0.01% (M / M) ethylene oxide complex is used, use blank test to determine whether the wetting agent is neutral If the wetting agent is used, the volume of water should be reduced to keep 10% (M / M) suspension Note: for pigments with low density, the concentration shall be less than 10% (M / M), which shall be described in the test report Record pH value, accurate to 0.1 unit, record suspension temperature, accurate to 1 ℃ If the difference of pH value measured by two parallel samples is greater than 0.3 unit, it shall be determined again 4 The expression of the result calculates the average value of the two measured values, accurate to 0.1 unit 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,