【国外标准】 Standard Practice for Evaluating Touch-Up Properties of Architectural Coatings under Various Environmental Conditions

5.1 During construction of a home, paints are subjected to a wide variety of drying conditions, and this may exhibit differences between the original coat and the touched-up area in appearance after its full cure. Therefore, it it essential for the paint to be able to perform under a wide variety of drying conditions. A paint that does this is very advantageous to the contractor.5.2 It is possible for a paint to have excellent color touch-up, but poor sheen touch-up, or vice-versa. The ideal paint will have both excellent color and sheen touch-up under testing conditions.5.3 Color, gloss and base choice can have a major impact on touch-up of the paint.1.1 This practice determines the ability of a paint to be recoated or “touched up” in small areas. Variations in color, gloss, and sheen that result in a different appearance from the original paint can be evaluated visually.1.2 This practice describes evaluation of touch-up characteristics in a laboratory-scale controlled environment as opposed to a full-scale field environment.1.3 Evaluation of touch-up properties under constant drying conditions is described. Environmental conditions can be adjusted to incorporate high or low temperature drying , or both. The changes in application temperature can lead to larger differences in touch-up than applying both coats under the same environmental conditions.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.