ASTM D476-15(R2021) pdf free download

ASTM D476-15(R2021) pdf free download.Standard Classification for Dry Pigmentary Titanium Dioxide Products
4. Basis for Classification
4.1 Titanium dioxide pigments can differ in many ways, including composition and performance. This classification outlines differences between pigment types that should be considered when selecting a product for a coating application. A minimum number of properties are given to highlight major differences, while allowing maximum flexibility.
5. Composition and Properties
5.1 Titanium Dioxide Pigments, should conform to the requirements for composition prescribed in Table 1. They are chemically prepared pigments consisting of anatase or rutile titanium dioxide with or without modifications with water- insoluble oxides of aluminum, silicon, zinc, etc., or other agents; these reagent materials are introduced specifically to improve those properties for which the pigment is used. The titanium dioxide pigments shall be free of extenders such as barium sulfate, clay, magnesium silicate, whiting, etc. 5.2 The desired properties of the pigment, other than as herein indicated, shall be subject to agreement between the purchaser and the seller and shall be based on a satisfactory match between the submitted pigment sample and a previously agreed upon reference sample (see 6.1.6).
6. Test Methods
6.1 Tests shall be conducted in accordance with the follow- ing test methods. Test procedures not covered by ASTM test methods shall be mutually agreed upon between the purchaser and the seller. 6.1.1 Chemical Analysis—Guide D34 or Test Methods D1394. 6.1.2 Specific Gravity—Test Methods D153. 6.1.3 Coarse Particles—Test Methods D185. 6.1.4 Moisture—Test Methods D280. 6.1.5 Matter Soluble in Water, Specific Resistance—Test Method D2448. The measured specific resistance of the aque- ous leachage from the pigment is an index of the level of water-soluble salts.6.1.6 Chalking Resistance—It is recommended that pur- chaser and seller agree upon standards and methods of test suitable for their requirements (see 5.2). Comparison in a good quality exterior air-dry alkyd enamel (trade sales or industrial) and exposure in Florida at 45° facing south are recommended. Chalking differences are minimized by less durable vehicles, while required exposure times are prolonged by more durable vehicles. Once the reference sample agreed upon between the purchaser and seller has qualified, subsequent shipments ofthat product may be compared with the reference sample by an agreed upon accelerated weathering test.
7. Keywords
7.1 anatase; dioxide pigments; rutile; titanium; white pig- ments