GB/T 7463-2026Surface active agents - Determination of the power to disperse calcium soap - Acidimetric method (Modifled Schoenfeldt method) (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document replaces GB/T 7463-2008 "Determination of the Dispersing Power of Calcium Soap Surfactants - Acid Titration Method (Modified Schoenfeldt)".

Compared with GB/T 7463-2008, the main technical changes in the "Law on the Protection of Minors" are as follows, apart from structural adjustments and editorial modifications.

---The oleic acid type used in the preparation of sodium oleate reagent has been removed (see 5.2.1 in the 2008 edition).

This document is modified to adopt ISO 6387:1983 "Determination of the dispersing power of calcium soaps by acid titration (modified Schoenfeldt)".

Law)".

This document differs in structure from ISO 6387:1983.A summary table comparing the structural numbering changes between the two documents is attached.

Record A.

This document differs technically from ISO 6387:1983; a vertical single line is drawn on the outer margin of the relevant clauses.

(|) are marked. A summary of these technical differences and their causes can be found in Appendix B.

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the China National Light Industry Council.

This document is under the jurisdiction of the National Technical Committee on Standardization of Surfactants and Detergents (SAC/TC272).

1 Scope

This document describes an acid titration method for determining the amount of surfactant (surfactant) required to maintain a complete dispersion of at least 95% of calcium soap for 1 hour.

Minimum amount of the active ingredient (hereinafter the same).

Note. This method can also provide data on the amount of partially dispersed calcium soap when the amount of dispersant is insufficient.

This document applies to all types of surfactants, as long as they do not interfere with the acid titration of calcium soap, but they cannot be stored.

In basic inorganic salts, such as phosphates, carbonates, and silicates.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 6682 Specifications and test methods for water used in analytical laboratories (GB/T 6682-2008, ISO 3696:1987, MOD) QB/T 2116-2006 Laundry Detergent

3 Terms and Definitions

The following terms and definitions apply to this document.

The amount of calcium soap completely dispersed by 1g of dispersant.

Note. Measured in grams.

4 Principles

Prepare a 0.5% (mass fraction) soap aqueous solution, and after standing at the test temperature for 24 hours, take a whole portion of this solution. [The rest of the text appears to be incomplete and requires further context.] Mix one part with a dilute solution of the dispersant. Then mix with a specified volume of water of known calcium hardness. Keep the mixture at the test temperature.

Let it stand at a certain temperature for 1 hour (to allow the calcium soap flocculent layer to reach the surface), and titrate a whole fraction of the lower layer with bromocresol green as an indicator and standard hydrochloric acid solution.

Calcium soap present in the solution.

5 Reagents

Unless otherwise specified, only reagents confirmed to be of analytical grade and water conforming to GB/T 6682 grade III or above shall be used in the analysis.

5.1 Water with known calcium hardness, 1000 mg/L.

Prepare and dilute to 1000 mg/L according to the provisions of A.5 in QB/T 2116-2006 for standardization.

5.2 Sodium oleate, 100 g/L aqueous solution.