Significance and Use

Control of water content is often important in controlling the performance of paint and paint ingredients, and it is critical in controlling volatile organic compound (VOC) content.

Paint materials are often insoluble in common Karl Fischer solvents such as methanol. Pyridine has been found to be a nearly universal solvent for these materials; however, the Karl Fischer reaction is too slow in that solvent at room temperature. To speed it up, 1-ethylpiperidine is added at 5 % as a buffer, or catalyst.

For nonpyridine-based reagents, a number of different solvent systems are available to increase solubility and to minimize interferences from ketones and aldehydes.

1. Scope

1.1 This test method is applicable to all paints and paint materials, including resins, monomers, and solvents, with the exception of aldehydes and certain active metals, metal oxides, and metal hydroxides. While the evaluation was limited to pigmented products containing amounts of water in the 30 to 70 % range, there is reason to believe that higher and lower concentrations can be determined by this test method.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only..

1.3 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. Specific hazard statements are given in Section 7.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D1193 Specification for Reagent Water

D3960 Practice for Determining Volatile Organic Compound (VOC) Content of Paints and Related Coatings

E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals

E203 Test Method for Water Using Volumetric Karl Fischer Titration

Keywords

Karl Fischer reagent method; moisture content; water content; Karl Fischer reagent method--water content; Moisture analysis--paints/related coatings/materials; Solvents--paints/related coatings/materials; Water content--paints/related coatings/materials; Latex paints; Monomers; Pyridine; Resins; Solventborne paints/coatings;

ICS Code

ICS Number Code 87.040 (Paints and varnishes)

DOI: 10.1520/D4017-02R08E01

ASTM International is a member of CrossRef.

ASTM D4017