1、DEUTSCHE NORM April 1995 c - a 5 P C I ; % c L c C - a p 2 z c c C Y E c C 2 c a c C 2 3 D c L L x U A? a E 1: I: n I * c c C 2 o DIN General methods of test for pigments and extenders Determination of pH value of an aqueous suspension English version of DIN EN IS0 787-9 EN IS0 787-9 (IS0 787-9 : 19
2、81) This standard incorporates the English version of Is0 787-9. ICs 87.060.10; 87.060.30 Descriptors: Pigments, extenders, pH value, testing. Allgemeine Prfverfahren fr Pigmente und Fllstoffe. Teil 9: Bestimmung des pH-Wertes einer wssrigen Suspension (IS0 787-9: 1981) Supersedes DIN IS0 787-9, Aug
3、ust 1983 edition. European Standard EN IS0 787-9: 1995 has the status of a DIN Standard. A comma is used as the decimal marker. National foreword This standard has been published in accordance with a decision taken by CEN/TC 298 to adopt, without alteration, International Standard IS0 787-9 as a Eur
4、opean Standard. The responsible German body involved in its preparation was the Norrnenausschu Pigmente und Fllstoffe (Pigments and Extenders Standards Committee). DIN V 53242-1 and DIN 43242-4 are the standards corresponding to International Standard IS0 842 referred to in clause 2. Amendments IS0
5、787-9 having been adopted as a European Standard, the status of the corresponding DIN Standard (DIN IS0 787-9) has been changed accordingly. Previous editions DIN 53200: 1965-09, 1978-12; DIN IS0 787-9: 1983-08. Standards referred to (and not included in Reference) DIN V 53242-1 DIN 53242-4 Raw mate
6、rials for paints and varnishes; sampling; concepts and general information Raw materials for paints and varnishes; sampling of solid matter EN comprises 4 pages. Eeoth Verlag GmbH, Berlin, has the exclusive right of sale for German Standards(DIN-Normen). 11.95 Sales No. 11 05 DIN EN IS0 787-9 Engl.
7、Price group EUROPEAN STANDARD NORME EUROPENNE EUROPAISCHE NORM EN IS0 787-9 March 1995 ICs 87.060.10; 87.060.30 Descriptors: Pigments, extenders, pH value, testing. English version General methods of test for pigments and extenders Part 9: Determination of pH value of an aqueous suspension (IS0 787-
8、9: 1981) Mthodes gnrales dessai des pig- ments et matires de charge. Partie 9: Dtermination du pH dune suspension Allgemeine Prfverfahren fr Pigmente und Fllstoffe. Teil 9: Bestimmung des pH-Wertes einer wssrigen Suspension aqueuse (IS0 787-9: 1981) (IS0 787-9: 1981) This European Standard was appro
9、ved by CEN on 1994-10-17 and is identical to the IS0 Standard as referred to. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipu- late the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bib
10、liographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility
11、of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal
12、, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1995. Copyright reserved to all CEN members. Ref. No. EN IS0 787-9:1995 E Page 2 EN IS0
13、 787-9 : 1995 Foreword International Standard IS0 787-9: 1981 General methods of test for pigments and extenders; determination of pH value of an aqueous suspension, which was prepared by ISO/TC 35 Paints and varnishes of the International Organization for Standardization, has been adopted by Techni
14、cal Committee CEN/TC 298 Pigments and extenders as a European Standard. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, and conflicting national standards withdrawn, by September 1995 at the latest. In accordance
15、with the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Endorsemen
16、t notice The text of the International Standard IS0 787-9:1981 was approved by CEN as a European Standard without any modifi- cation. Page 3 EN IS0 787-9: 1995 O Introduction This document is a part of IS0 787, Generaimethods of test for pigments and extenders. 1 Scope and field of application This
17、part of IS0 787 specifies a general method of test for determining the pH value of an aqueous suspension of a sam- ple of pigment or extender. NOTE - When this general method is applicable to a given pigment or extender, only a cross-reference to it should be included in the Interna- tional Standard
18、 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 determination of pH value be speci
19、fied. 2 Reference IS0 842, Raw materiais for paints and varnishes - Sampling. 3 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 glas
20、s, immediately before use. It shall be boiled for 5 to 10 min only, in order to 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
21、 more than 30 min. The closed container should be pro- tected by a soda asbestos tube or similar device. 4 Apparatus 4.1 resistant glass, fitted with a ground glass or rubber stopper. Glass container, of capacity 50 ml, made of chemically Before using the container for the first time, boil dilute hy
22、drochloric 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. 4.2 pH measuring device, capable of measurement to 0,l unit, calibrated against buffer solutions of known pH value at the temperature of the t
23、est. 4.3 Balance, with an appropriate accuracy. 5 Sampling Take a representative sample of the material to be tested as described in IS0 842. 6 Procedure Carry out the determination in duplicate at room temperature. Prepare a 10 % (mlml suspension of the material under test, using the distilled wate
24、r (clause 31, 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, the pH value of the suspension. If the material does not disperse easily in water, a wetting agent should be us
25、ed; 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 from pyridine. In the case of pigments soluble in ethanol, a neutral non-ionic wetting agent such as 10 ml of a
26、0,Ol % (mim) 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 volume of the water should be reduced so that a 10 % (m/m) suspension is obtained. The type and quantity of wet
27、ting agent used shall be stated in the test report. NOTE - With pigments and extenders of relatively low density, it may be necessary to use a suspension of less than 10 % Irn/mi. In such cases the concentration of the suspension used should be stated in the test report. Record the pH values to the
28、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. Page 4 EN IS0 787-9 : 1995 7 Expression of results b) a reference to this International Standard (IS0 787/9); Calcul
29、ate the mean of two determinations and report the result to the nearest 0,l unit. c) if used, the type and quantity of wetting agent; dl the result of the test as indicated in clause 7, and the test temperature; e) any deviation, by agreement or otherwise, from the procedure specified; 8 Test report 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.
