ASTM D476-15 (R2021) pdf free download.Standard Classification for Dry Pigmentary Titanium Dioxide Products.
1.1 This classification describes eight types of dry pigmentary titanium dioxide products. grouped by composition, typical end use application, and some performance properties.
1 .2 The values stated in SI units are to he regarded as standard. No other units of measurement are included in this standard.
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 he 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 waterinsoluble 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 he 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 he based on a satisfactory match between the submitted pigment sample and a previously agreed upon reference sample (see 6. 1.6).
6. 1 .6 Chalking Resistance—It is recommended that purchaser and seller agree upon standards and methods of test suitable for their requirements (sec 5.2). Comparison in a good quality exterior air-dry alkyd enamel (trade sales or industrial) and exposure in Florida at 450 facing south are rccommcndcd. 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 of that 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 pigments.ASTM D476 pdf download.