787/21 International Standard OSI) INTERNATIONAL OKGANIZATION FOR STANDARDIZATION+MEXAYHAPOAHAA OPTAHW3ALMA NO CTAHAAPTW3AUMW+ORGANISATION INTE RNATIONALE DE NORMALISATION Generalmethodsoftestforpigmentsandextenders Part 21 : Comparison of heat stability of pigments using a stoving medium Methodesgenerales d'essai des pigments et matieres de charge Partie 21 : Comparaison de la stabilite a la chaleur des pigments en utilisant un liant au four First edition 1979-12-15 ISO 787/21-1979 (E) UDC 667.622 : 620.1 : 531.495 Ref.No.1SO787/21-1979 (E) Sescriptors : paints, pigments, tests, high temperature tests, stability tests, thermal stability, comparative tests. Price based on 2 pages Preisgr. B Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards institutes (iso member bodies). The work of developing Interna- tional 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 governmental, in liaison with Iso, also take part in the work. Draft International Standards adopted by the technical cormmittees are circulated to the memberbodies forapproval before their acceptance as International Standards by the ISO Council. International Standard ISO787/21 was developedby Technical Committee ISO/TC 35,Paints and varnishes, and was circulated to the member bodies in March 1978. It has been approved by the member bodies of the following countries : Australia Israel Romania Bulgaria Italy South Africa, Rep. of Canada Kenya Sweden Egypt, Arab Rep. of Korea, Rep. of Switzerland Netherlands Germany, F. R. Turkey India New Zealand United Kingdom Iran Norway Yugoslavia Ireland Poland The member body of the following country expressed disapproval of the document on technical grounds : France International OrganizationforStandardization,1979 Printed in Switzerland ii 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 individual pigments and extenders for which specifications might be required. In such cases, a cross-referencc 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 decided that all the general methods should be published as they become available, as parts of a single International 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 widely used for determining the same or a similar characteristic of a pigment or ex- tender, there wouid be no objection to including more than one of them in the Iso scrics. 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 Part 1 : Comparison of colour 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 : Determination of residue on sieve -- Oil method Part 6 Part 7 : Determination of residue on sieve -Water method Part 8 : Determination of matter soluble in water - Cold extraction method Part 9 :Determination ofpHvalue ofanaqueous suspension Part10:Determinationof density-Pyknometermethod Part 11 : Determination of tamped volume and apparent density after tamping Part12:Visual comparison of hue of powdered white pigment (Hollow cone method)1) Part 14 : Determination of resistivity of aqueous extract Part 15 : Comparison of resistance of coloured pigments of similar types to