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GB/T 9268-1988《Determination of freeze-thaw resistance of latex paints》

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Home> Standard> GB/T 9268-1988《Determination of freeze-thaw resistance of latex paints》

GB/T 9268-1988 "Determination of freeze-thaw resistance of latex paints" is applicable to the determination of synthetic latex or synthetic resin emulsion as a paint. Test method for whether the viscosity of water-based paints with synthetic latex or synthetic resin emulsion is damaged in terms of anti-coalescence or anti-clumping and spots after being frozen and melted.

Number: GB/T 9268-1988Name: Determination of freeze-thaw resistance of latex paintsStatus: Abolish

Theme content and scope of application

This standard specifies a method for determining the freeze-thaw resistance of latex paints

This standard is suitable for testing whether there are any damaging changes in the viscosity, resistance to agglomeration or caking and spotting of water-based paints based on synthetic latex or synthetic resin emulsion after being frozen and thawed, and to determine the extent to which the original performance is maintained. method.

Reference Standard

GB1726 Determination of hiding power of coatings

GB3186 Sampling of coating products

GB9269 Determination of viscosity of architectural coatings - Stormer viscometer method

instrument

1. Freezer : A suitable box, the size of which should be able to accommodate several test samples, and the temperature inside the box should be able to be maintained at -18±2℃.

2. Test panel : a smooth-surfaced cardboard with adjacent black and white areas, covered with varnish so that the surface can be evenly coated with paint film without the paint liquid penetrating. Glass plates with black and white areas, such as those specified in GB 1726, can also be used.

3. Viscometer : Stormer viscometer with paddle-type rotor.

4. Paint brush : soft brush with a width of about 25mm.

Sample Preparation

1. Sampling according to GB 3186.

2. Stir the sample to be tested evenly and put it into a 500ml lined iron can with a sealing lid or a large-mouth glass or plastic bottle with a sealing lid. The filling amount is 2/3 of the container. , the container should be clean and the lid should be closed in time to prevent evaporation loss.

3. For each paint liquid tested, two identical samples should be prepared.

test

1. Use an ordinary stainless steel paint mixing knife to manually stir the test sample in the container (be careful when stirring to avoid bubbles). Then measure its initial viscosity according to GB 9269. After the test, seal the sample tightly, mark it with the words "Comparative Sample", and store it at 23±2℃.

2. After stirring another sample of the same sample according to the provisions of Article 1, mark it with the words "test sample" and put it in the freezer. The freezer temperature is maintained at -18±2°C. The sample jars must not be in contact with the box wall or bottom. There must be at least a 25mm gap between adjacent sample jars and between the sample jars and the box wall to facilitate the free circulation of air around the sample (the sample jar can be placed on a rack). The jar was placed in the freezer for 17 hours and then taken out and allowed to stand at 23 ± 2°C.

Note: During the entire mixing process, the comparison sample and the test sample should be treated exactly the same.

Inspection and result evaluation

1. Take the test sample out of the freezer and place it for 6 hours and 48 hours for inspection and evaluation respectively.

2. Before stirring the test sample, observe and evaluate the sedimentation, cementation, agglomeration, agglomeration and other conditions of the sample in the container, and indicate it as "no change", "slight" or "serious".

3. Stir and measure the viscosity of the test sample according to the provisions of Test 1.

4. After measuring the viscosity, immediately use a clean soft brush to brush the comparison sample and the test sample on the same test plate and dry for at least 24 hours. Then compare the test sample and the comparison sample, and visually observe and record the hiding power of the dry paint film. Changes in gloss, condensation, spots and color.

experiment report

The test report should at least include the following content:

a. Name, model, batch, production date and factory name of the tested material.

b. Measure the viscosity of the "test sample" and "comparison sample" of the test material, and indicate the time interval (i.e. at the beginning, 6 hours after freezing, 48 hours after freezing).

c. Visually observed changes in samples and dry paint films.

d. Test operator.

e. Test date.

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