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1、International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIATINOMEYPYHAPOHAR oPrAw3Au4n no CTAHAAC(AUHHRGANSATON ITERNATIONALE DE ORMALISATION #$qpJS fYJ*yc-, ;j.yjcc :- ; $.cy$ . / General methods of test for pigments and extenders - Part 23 : Determination of density (using a centrifuge to rem
2、ove entrained air) M 8 Descriptors : paints, pigments, tests, density measurement. z Price based on 2 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:49:22 MDTNo reprodu
3、ction or networking permitted without license from IHS -,-,- Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 member bodies). The work of developing Interna- tional Standards is carried out through IS0 technical committ
4、ees. 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
5、 the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. International Standard IS0 787/23 was developed by Technical Committee ISO/TC 35, Paints and varnishes, and was circulated to the member bodies in March 1
6、978. It has been approved by the member bodies of the following countries : Austria Bulgaria Canada Egypt, Arab Rep. France Germany, F. R. India Iran of Ireland Poland Israel Romania Italy South Africa, Rep. of Kenya Sweden Korea, Rep. of Switzerland Netherlands Turkey New Zealand United Kingdom Nor
7、way Yugoslavia No member body expressed disapproval of the document. International Organization for Standardization, 1979 0 Printed in Switzerland ii , Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not f
8、or Resale, 04/28/2007 07:49:22 MDTNo reproduction or networking permitted without license from IHS -,-,- 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
9、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 i
10、n 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 p
11、rocedures were widely used for determining the same or a similar characteristic of a pigment or ex- tender, 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 an
12、d, 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 OC Part 3 : Determination of matter soluble in water - Hot extraction method Part 4 : Determination of acidity or a
13、lkalinity 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 Part 8 : Determination of matter soluble in water - Cold extraction method Part 9 : Determination of pH va
14、lue of an aqueous suspension Part 10 : Determination of density - Pyknometer method Part 11 : Determination of tamped volume and apparent density after tamping Part 12 : Visual comparison of hue of powdered white pigment (Hollow cone methodIt) Part 13 : Determination of water-soluble sulphates, chlo
15、rides and nitrates Part 14 : Determination of resistivity of aqueous extract Part 15 : Comparison of resistance of coloured pigments of similar types to light from a specified light source Part 16 : Comparison of relative tinting strength (or equivalent colouring value) and colour on reduction in li
16、nseed stand oil using the automatic muller Part 17 : Comparison of lightening power of white pigments Part 18 : Determination of residue on sieve by a mechanical flushing procedure Part 19 : Determination of water-soluble nitrates - Salicylic acid method Part 20 : Comparison of ease of dispersion -
17、Oscillatory shaking method Part 21 : Comparison of heat stability of pigments using a stoving medium Part 22 : Comparison of resistance to bleeding of pigments Part 23 : Determination of density (using a centrifuge to remove entrained air) 1) This part will be withdrawn as the specified method is no
18、 longer in use. iii Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:49:22 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0
19、797/23-1979(E) General methods of test for pigments and extenders - Part 23 : Determination of density (using a centrifuge to remove entrained air) 0 Introduction This document is a part of IS0 787, Generalmethods of test for pigments and extenders. 1 Scope and field of application 1.1 Part 23 of th
20、is International Standard specifies a general method of test for determining the density of a sample of pig- ment or extender, using a centrifuge to remove entrained air. NOTE - When this general method is applicable to a given pigment or extender, only a cross-reference to it should be included in
21、the 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 determ
22、ination of density using a centrifuge be specified. 1.2 Part 10 of this International Standard specifies a general method of test for determining the density of a sample of pig- ment or extender, using a pyknometer. 2 References IS0 787, General methods for pigments and extenders - Part 10 : Determi
23、nation of density - Pyknometer method. ) IS0 842, Raw materials for paints and varnishes - Sampling. 3 Preliminary considerations 3.1 Displacement liquids of known density A liquid should be selected in which the material to be tested is insoluble, and which has good wetting properties and a low eva
24、poration rate under vacuum. High-boiling aromatic or aliphatic hydrocarbon solvents with a boiling point over 170 % are suitable. Particular care, however, may be necessary in the selection of the liquid if carbon black or organic dyestuffs are to be examined. 3.2 Temperature of the determination Th
25、e temperature tat which the determination is carried out will significantly affect the density of the displacement liquid used, but not that of the material tested. When using this method, therefore, it is most important that each weighing should be made at a constant temperature. It is desirable th
26、at a constant temperature room or enclosure should be used but if these are not available the temperature at which each weighing is made should be noted and corrections made to the density of the displacement liquid. 4 Apparatus 4.1 Centrifuge tube of glass or other suitable material such as polypro
27、pylene or stainless steel. 4.2 Cradle and loop of fine platinum or nickel-chromium wire not more than 0,12 mm diameter to suspend the tube from the balance. 4.3 Glass stirring rod, slightly longer than the tube (4.1). 4.4 Centrifuge, laboratory type. 4.5 Sieve, with nominal mesh aperture of 500 pm.
28、4.6 Balance, accurate to 1 mg or better. 5 Sampling Take a representative sample of the material to be tested as described in IS0 842. 1) At present at the stage of draft. (Revision of ISO/R 787/10-1970.) 1 Copyright International Organization for Standardization Provided by IHS under license with I
29、SO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:49:22 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 787/23-1979 (E) 6 Procedure where 6.1 Test portion Thoroughly mix a sufficient quantity of the test sample to oc- cupy about half the vo
30、lume of the centrifuge tube (4.11, and pass it through the sieve (4.5). Dry by heating it at 105 + 2 OC for 2 h and allow to cool to room temperature in a desiccator. 6.2 Determination Clean and thoroughly dry the tube and stirring rod (4.3). Sus- pend them from the balance (4.6) by means of the cra
31、dle and loop (4.2) and weigh them in air. Completely immerse the tube and stirring rod in the displace- ment liquid contained in a 250 ml beaker, and allow to stand for a sufficient time in the constant-temperature room or enclosure for the whole to reach the temperature of the room or enclosure (th
32、e time necessary for this may be 1 h or longer). Suspend the tube and stirring rod from the balance and weigh. Remove the tube and stirring rod from the displacement liquid and wipe them clean and dry. Weigh into the tube a quantity of the dried sample sufficient to occupy about half the volume (the
33、 quantity required for this is from 1 to IO g depending on the density). Add displacement liquid to the material in the tube, gradually and with careful stirring, until the material is wetted and completely covered and has a layer of clear liquid above it. Add further displacement liquid to bring th
34、e level to about 13 mm from the top of the tube. Place the tube, complete with stirring rod, into the centrifuge (4.41, suitably balanced, and spin it until the occluded air is removed and the solid material is reduced to a closely packed mass (for a centrifuge operating at 4 500 r/min a period of 1
35、5 min should be sufficient). Remove the tube from the centrifuge and fill it with displace- ment liquid. Lower the tube and stirring rod carefully into a 250 ml beaker containing displacement liquid, and allow the whole to stand in the constant-temperature room or enclosure until the temperature of
36、the whole is at the temperature of the room or enclosure. Suspend the tube and stirring rod by means of the cradle and loop and weigh. 7 Expression of results Calculate the density of the material tested, expressed in grams per millilitre, by the formula ml is the mass, in grams, of the cradle (4.21
37、, tube (4.1 I and stirring rod (4.3) in the displacement liquid; m2 is the mass, in grams, of the material in air; m3 is the mass, in grams, of the cradle, tube, stirring rod and material in the displacement liquid; Q is the density, in grams per millilitre, of the displacement liquid at the tempera
38、ture t. 8 Precision 8.1 Repeatability (4 The value below which the absolute difference between two single test results on identical material, obtained by one operator in one laboratory using the same equipment within a short interval of time using the standard test method, may be expected to lie wit
39、h a 95 % probability, is 0,03 g/ml. 8.2 Reproducibility (R) The value below which the absolute difference between two test results, each the mean of duplicate measurements, on identical material, obtained by operators in different laboratories, using the standardized test method, may be ex- pected t
40、o lie with a 95 % probability, is 0,05 g/ml. 9 Test report The test report shall include at least the following information : a) the type and identification of the product tested; b) a reference to this International Standard or to a cor- responding national standard; c) details of the displacement
41、liquid used and the temperature of the determination; d) any deviation, by agreement or otherwise, from the test procedure specified; e x m2 e) the result of the test; m2 - (m3 - ml) 2 f) the date of test. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 07:49:22 MDTNo reproduction or networking permitted without license from IHS -,-,-
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