Ansi Internat Doc Sect International Standard (ISO 4621 Chrome oxide green pigments -- Specifications and methods of test Pigments verts d'oxyde de chrome - Speécifications et methodes d'essai First edition --- 1986-07-15 ISO 4621-1986 (E) UDC 667.622.117.61 Ref. No. ISO 4621-1986 (E) Descriptors : paints, pigments, chromium oxides, specifications, tests. Price based on 5 pages No reproduction or networking permitted without license from IHS Not for Resale Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental 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 least 75 % approval by the member bodies voting. International Standard ISO 4621 was prepared by Technical Committee ISO/TC 35, Paintsand varnishes. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. C InternationalOrganizationforStandardization,1986 Printed in Switzerland ional Organizati No reproduction or networking permitted without license from IHS ISO 4621-1986 (E) INTERNATIONAL STANDARD Chrome oxide green pigments - Specifications and methods of test 1 Scope and field of application ISo 6713,Paints and varnishes-Preparation of acid extracts from paints in liquid or powder form. This International Standard specifies the requirements and cor- responding methods of test for chrome oxide green pigments suitable for general use. 3Definition chrome oxide green pigment: An inorganic, coloured pig- 2 References ment consisting essentially of chromium(lll) oxide (Cr2O3) in the form of a dry powder. ISo385/1, Laboratoryglassware-Burettes-Part1: General requirements. 4 Classification ISo 648, Laboratory glassware - One-mark pipettes. This International Standard specifies the following three grades Iso 787, General methods of test for pigments and ex- of chrome oxide green pigments, which shall not be in admix- tenders ture with other colouring matter of organic or inorganic nature and shall be free from extenders or diluents (see also the note Part 1: Comparison of colour of pigments. to clause 9). Part 2: Determination of matter volatile at 105 oC. Grade 1: These pigments shall contain a residue on a sieve of 45 μm mesh aperture of not more than 0,01 % (m/m). Part 3: Determination of matter soluble in water -- Hot extractionmethod. Grade 2: These pigments shall contain a residue on a sieve of45μmmeshapertureofmorethan0.01%(m/m)and Part 5: Determination of oil absorption value. not more than 0,1 % (m/m). Part 7: Determination of residue on sieve -- Water method Grade 3: These pigments shal contain a residue on a sieve - Manual procedure. of45μmmeshapertureofmorethan0,1%(m/m)andnot more than 0,5 % (m/m). Part9:DeterminationofpHvalueofanaqueoussuspen- sion. Part 16: Determination of relative tinting strength (or 5 Required characteristics and their equivalent colouring value) and colour on reduction of tolerances coloured pigments -. Visual comparison method. 5.1 For chrome oxide green pigments complying with this Part 20: Comparison of ease of dispersion (Oscillatory shak- International Standard, the essential requirements are specified ing method). in table 1and the conditional requirements are referred to in table 2. For the conditional requirements according to table 2, ISo 842, Raw materials for paints and varnishes - Sampling. agreement between the intere