1.1 本试验方法包括测量某些碱溶性树脂中的游离酸度。 1.2 本试验方法不适用于苯乙烯-马来酸酐树脂。 1.3 树脂制造商应说明该测试方法是否可用于其产品。 1.4 以国际单位制表示的值应视为标准值。本标准不包括其他测量单位。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 4.1 本试验方法不适用于酸官能度因酸酐而产生的碱溶性树脂。酸酐功能树脂的制造、储存和可能污染的变化可能导致部分水解或酯化，这将使本试验方法的数据无效。 酸酐功能树脂应通过试验方法进行表征 第644页 . 4.2 本试验方法用于测量酸官能化树脂的性能。酸值决定了树脂的效用，也是一项重要的质量控制措施。

1.1 This test method covers the measurement of the free acidity present in certain alkali-soluble resins. 1.2 This test method is not suitable for styrene-maleic anhydride resins. 1.3 The resin manufacturer should specify whether or not this test method may be used for his product(s). 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 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. ====== Significance And Use ====== 4.1 This test method is not appropriate for alkali-soluble resins whose acid functionality is due to incorporated anhydrides. Variations in manufacture, storage, and possible contamination of anhydride functional resins may cause partial hydrolysis, or esterification, which will invalidate data from this test method. Anhydride functional resins should be characterized by Test Method D3644 . 4.2 This test method is used to measure a property of acid functionalized resins. Acid number determines the utility of resins as well as being a significant quality control measure.