787/4 International Standard (ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATION+MEXAYHAPOAHAR OPTAHM3AWA IO CTAHAAPTM3AUMM+ORGANISATION INTERNATIONALE DE NORMALISATION General methods of test for pigments and extenders Part 4 : Determination of acidity or alkalinity of the agueousextract Methodes generales d'essai des pigments et matieres de charge -Partie 4: Determination de Iacidite ou de I'alcalinite de I'extraitaqueux Firstedition-1981-09-15 UDC667.622:543.241 Ref.No. 1SO 787/4-1981 (E) Descriptors : paints, pigments, tests, chemical analysis, determination, acidity, alkalinity, extraction analysis. Price based on 2 pages Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (Iso member bodies). The work of developing Inter- national Standards is carried out through Iso technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented:on.that committee. International organizations, governmental and non-governmental, in liaison with Iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISo Council. International Standard ISO787/4wasdeveloped byTechnical CommitteeISO/TC35, Paints and varnishes, and was circulated to the member bodies in December 1979. It has been approved by the member bodies of the following countries : Australia India Poland Austria Ireland Romania Israel South Africa, Rep. of Canada Italy Spain China Kenya Sweden Egypt, Arab Rep. of Korea, Rep. of Switzerland France Netherlands United Kingdom Norway Germany, F. R. USSR No member body expressed disapproval of the document. This International Standard cancels and replaces ISo Recommendation R 787/4-1968, of which it constitutes a technical revision. InternationalOrganizationforStandardization,1981 Printed in Switzerland i The purpose of this International Standard is to establish a series of general test methods for pigments and extenders which are suitable for all or many of the individuai pigments and extenders for which specifications might be required. In such cases, a cross-reference to the general method should be included in the International Standard relating to that pigment or extender, with a note of any detailed modifications which might be needed in view of the special properties of the product in question. Technical Committee ISO/TC 35, Paints and varnishes, decided that all the general methods should be published as they become available, as parts of a single Interna- tional Standard, in order to emphasize the relationship of each to the whole series. The Technical Committee also decided that, where two or more procedures were wide- iy used for determining the same or a similar characteristic of a pigment or extender, there would be no objection to including more than one of them in the Iso series. In such cases it will, however, be essential to state clearly in a specification which method is to be used and, in the test report, which method has been used. Parts of the series already published are as follows : Part1: Comparison of colour of pigments Part 2: Determination of matter volatile at 105 C Part 3: Determination of matter soluble in water --Hot extraction method Part 4 : Determination of acidity or alkalinity of the aqueous extract Part 5 : Determination of oil absorption value Part 6 : Determination of residue on sieve - Oil method Part 7 : Determination of residue on sieve -- Water method - Manual procedure Part8: Determination of matter soluble in water- Coldextractionmethod Part 9 : Determination of pH value of an aqueous suspension Part 10 : Determination of density-- Pyknometermethod Part 11 : Determination of tamped volume and apparent density after tamping Part 13 : Determination of water-soluble sulphates, chlorides and nitrates P