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1、General methods of test for pigments and extenders - Part 9 : Determination of pH value of an aqueous suspension Mthodes gnrales dessai des pigments et matires de charge - Partie 9 . = Dtermination du pH dune suspension aqueuse First edition - 1981-09-15 COPYRIGHT International Organization for Stan
2、dardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services 787 PT 7-81 Fo re wo r d IS0 (the Internetional Organitatlon for Standardization) is a worldwide federation of national standards Institutes (IS0 m
3、ember bodies), The work of developlnfj Inter- national Standards Is carried out through 180 technical committees, Every member body interested in a subJect for whlch a technical committee has been Bet up has the right to be represented on that committee, International organhations, governmental and
4、non-governmental, In liaison with ISO, elso take part In the work. Draft Internatlonal Standards adopted by the teChniCRl committee8 ere circulrrted to the member bodies for approval before their acceptance as International Standarde by the IS0 Council, International Standard IC0 787/9 was developed
5、 by Technical Committee ICO/TC 35, Paints and varnishes, and was circulated to the member bodies in November 1070. It has beon approved by the member bodies of the following countriee : Australla Austria Brazil Canada China France Germany, F. R, India Ireland Romania Israel South Africa, Rep, of Ita
6、ly Spain Kenya Sweden Korea, Rep, of Switzerland Netherlands United Kingdom Norway USSR Poland No member body expressed disapproval of the document, This Internatlonal Standard cancels and replaces IS0 Recommendation R 787/9=1070, of which It constitutes a technical revision. O International Organiz
7、etion far Standardlnation, 1981 Printed i n Switzerland li 4853903 0073081 q r COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services The purpose of this Int
8、ernational 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-reference to the general method should be included in the Int
9、ernational 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 the
10、y 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- ly used for determining the same or a similar characteristic of a pigment or exten
11、der, there would be no objection to including more than one of them in the IS0 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
12、 : Part 1 : Comparison of colour of pigments Part 2 : Determination of matter volatile at 105 O 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 : D
13、etermination of residue on sieve - Oil method Part 7 : Determination of residue on sieve - Water method - Manual procedure Part 8 : Determination of matter soluble in water - Cold extraction method Part 9 : Determination of pH value of an aqueous suspension Part 10 : Determination of density - Pykno
14、meter method Part 11 : Determination of tamped volume and apparent density after tamping Part 13 : Determination of water-soluble sulphates, chlorides and nitrates Part 14 : Determination of resistivity of aqueous extract Part 15 : Comparison of resistance of coloured pigments of similar types to li
15、ght from a specified light source Part 16 : Comparison of relative tinting strength (or equivalent colouring value) and colour on reduction in linseed stand oil using the automatic muller Part 17 : Comparison of lightening power of white pigments Part 18 : Determination of residue on sieve - Water m
16、ethod - Mechanical flushing procedure Part 19 : Determination of water-soluble nitrates - Salicylic acid method Part 20 : Comparison of ease of dispersion - Oscillatory shaking method Part 21 : Comparison of heat stability of pigments using a stoving medium Part 22 : Comparison of resistance to blee
17、ding of pigments Part 23 : Determination of density (using a centrifuge to remove entrained air) Part 24 : Determination of relative tinting strength of coloured pigments and relative scattering power of white pigments - Photometric method COPYRIGHT International Organization for Standardization Lic
18、ensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services INTERNATIONAL STANDARD IS0 787/9-1981 (E) 4853903 0073083 2 - 787 PT 7-81 - General methods of test for pigments and extenders - Part 9 : Determination of pH valu
19、e of an aqueous suspension O Introduction 4.2 pH measuring device, capable of measurement to 0,l unit, calibrated against buffer solutions of known pH value at This document is a part of IS0 787, Generalmethods of test for the temperature of the test. pigments and extenders. 4.3 Balance. with an app
20、ropriate accuracy. 1 This part of IS0 787 specifies a general method of test for determining the pH value of an aqueous suspension of a cam- ple of pigment or extender. NOTE - When fhis general method is applicable to a given pigment or extender, only a cross-reference to it should be included in th
21、e Interna- tional Standard relating to that pigment or extender, with a note of any detailed modification which may be needed in view of the special pro- perties of the material in question. Only when this general method is not applicable to a particular material should a special method for determin
22、ation of pH value be specified. Scope and field of application 5 sampling Take a representative sample of the material to be tested as described in 842. 6 Procedure Carry out the determination in duplicate at room temperature. 2 Reference IS0 842, Raw materials for paints and varnishes - Sampling. 3
23、 Reagent Freshly distilled water, boiled before use to remove carbon dioxide, or water otherwise prepared of at least equivalent pu- rity. The water shall be boiled and cooled in a vessel made of chemically resistant glass, immediately before use. It shall be boiled for 5 to 10 min only, in order to
24、 avoid an increase of its pH value due to alkali dissolved from the glass vessel. Because water rapidly absorbs carbon dioxide, the cooled water shall be protected from access to the atmosphere and shall be stored for not more than 30 min. The closed container should be pro- tected by a soda asbesto
25、s tube or similar device. Prepare a 10 % (m/rn) suspension of the material under test, using the distilled water (clause 3), in the glass container (4.1). Stopper the container and shake it vigorously for 1 min. Allow it to stand for 5 min, remove the stopper and determine, to the nearest 0,l unit,
26、the pH value of the suspension. If the material does not disperse easily in water, a wetting agent should be used; in the case of materials not soluble in ethanol, up to 5 ml of ethanol may be used but care should be taken to ensure that the minimum quantity is used and that it is neutral and free f
27、rom pyridine. in the case of pigments soluble in ethanol, a neutral non-ionic wetting agent such as 10 ml of a 0,Ol % (m/rn) solution of an ethylene oxide condensate should be used. The neutrality of the wetting agent should be checked by making a blank determination. If a wetting agent is used, the
28、 volume of the water should be reduced so that a 10 % (rn/rn) suspension is obtained. The type and quantity of wetting agent used shall be stated in the test report. 4 Apparatus 4.1 resistant glass, fitted with a ground glass or rubber stopper. Before using the container for the first time, boil dil
29、ute hydrochloric acid placed in the container and then rinse it thoroughly with distilled water, The rubber stopper shall not have been used for any other purpose. NOTE - With pigments and extenders of relatively low density, it may be necessary to use a suspension of less than 10 % (rn/rn). In such
30、 cases the concentration of the suspension used should be stated in the test report. Record the pH values to the nearest 0,l unit and record the temperature of the suspension to the nearest 1 OC. If the duplicate determinations of pH differ by more than 0,3 unit, the procedure shall be repeated. Gla
31、ss container, of capacity 9 mi, made of chemically 1 COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services IS0 787/9-1981 (E) 7 Expression of results b) a r
32、eference to this International Standard (IS0 787/9); Calculate the mean of two determinations and report the result to the nearest 0,l unit. 8 Test report c) if used, the type and quantity of wetting agent; d) the result of the test as indicated in clause 7, and the test temperature; e) any deviatio
33、n, by agreement or otherwise, from the procedure specified; The test report shall contain at least the following information : a) the type and identification of the product tested; f) the date of the test. COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services