GB/T 6744-2008 in English

《GB/T 6744-2008色漆和清漆用漆基 皂化值的测定 滴定法》由TC5（全国涂料和颜料标准化技术委员会）归口，主管部门为中国石油和化学工业联合会。
本标准于１９８６年首次发布。本标准代替ＧＢ／Ｔ６７４４―１９８６《色漆和清漆用漆基皂化值的测定法》。本标准规定了以滴定法测定色漆和清漆用漆基中被酯化的酸的含量（包括漆基中游离酸和酸酐的含量）的步骤。本标准不适用于超出正常皂化作用而与碱可进一步反应的漆基。本标准与ＧＢ／Ｔ６７４４―１９８６的主要技术差异为：
―――前版系等效采用ＩＳＯ３６８１：１９８３。
―――增加了试验方法的原理。
―――修改了皂化值的定义和计算公式。

Scope

This standard specifies the procedure for determining the content of esterified acid (including the content of free acid and anhydride in the binder) in the binder for paints and varnishes by titration. Due to the different saponification resistance of different paint bases, this standard has limitations in application. If necessary, the experiment can be repeated under more severe conditions to test the complete saponification value, such as prolonging the saponification time, increasing the concentration of potassium hydroxide solution, or using alcohol with a higher boiling point as a solvent. This standard does not apply to binders that can further react with alkali beyond normal saponification. Appendix A specifies the method for the determination of the saponification value of hard-to-saponifiable paint bases.