BS EN ISO 787-24-1988 General methods of test for pigments and extenders - Determination of relative tinting strength of coloured pigments and relative scattering power of white pi.pdf

1、BRITISH STANDARD BS EN ISO 787-24:1995 Incorporating Amendment No. 1 General methods of test for pigments and extenders Part 24: Determination of relative tinting strength of coloured pigments and relative scattering power of white pigments Photometric methods The European Standard EN ISO 787-24:199

2、5 has the status of a British Standard ICS 87.060.10BSENISO787-24:1995 This British Standard, having been prepared under the direction of the Pigments, Paints and Varnishes Standards Committee, was published under the authority of the Board of BSI and comes into effect on29February1988 BSI 03-2000 F

3、irst published February1988 The following BSI references relate to the work on this standard: Committee reference PVC/1 Draft for comment 80/55689 DC ISBN 0 580 16396 2 Amendments issued since publication Amd. No. Date of issue Comments 8681 December 1995 Indicated by a sideline in the marginBSENISO

4、787-24:1995 BSI 03-2000 i Contents Page National foreword ii Foreword 2 Text of EN ISO 787-24 3 Publications referred to Inside back coverBSENISO787-24:1995 ii BSI 03-2000 National foreword This Part of BS3483 has been prepared under the direction of the Pigments, Paints and Varnishes Standards Comm

5、ittee. It is identical with ISO787-24:1985 “General methods of test for pigments and extenders Part 24: Determination of relative tinting strength of coloured pigments and relative scattering power of white pigments Photometric methods” published by the International Organization for Standardization

6、 (ISO). In 1995 the European Committee for Standardization (CEN) accepted ISO787-24:1985 as European Standard EN ISO787-24:1995. As a consequence of implementing the European Standard this British Standard is renumbered as BS EN ISO787-24 and any reference to BS3483-A6 should be read as a reference

7、to BS EN ISO787-24. It has been assumed in the drafting of this standard that the execution of its provisions will be entrusted to appropriately qualified and experienced people. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a Br

8、itish Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the basel

9、ine as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”, “this part of ISO787” should be read as “this Part of BS3483”, and “ISO787-24” should be read as “BS3483-A6”. Cross-references International Standard

10、Corresponding British Standard ISO 591:1977 BS 1851:1978 Specification for titanium dioxide pigments for paints (Identical) BS 3483 Methods for testing pigments for paints ISO 787-2:1981 Part B6:1982 Determination of matter volatile at105 C (Identical) ISO 787-9:1981 Part C4:1982 Determination of pH

11、 value of an aqueous suspension (Identical) ISO 787-16:1986 Part A4:1988 Determination of relative tinting strength and colour on reduction of coloured pigments using visual comparison (Identical) ISO 787-17:1973 (published as Parts XIII to XVIII) Part A5:1974 Comparison of lightening power of white

12、 pigments (Technically equivalent) ISO 787-23:1979 Part B9:1980 Determination of density relative to water (using a centrifuge) (Identical) ISO 842:1984 BS 4726:1986 Methods for sampling raw materials for paints and varnishes (Identical) ISO 1524:1983 BS 3900 Methods of test for paints Part C6:1983

13、Determination of fineness of grind (Identical)BSENISO787-24:1995 BSI 03-2000 iii The Technical Committee has reviewed the provisions of ISO 787-10, ISO4652, and ISO6209, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A rela

14、ted British Standard to ISO 787-10 is BS3483-B8:1982 “Determination of density (pyknometer method)”. No British Standard corresponds either to ISO4652 or to ISO6209. Additional information. In order to carry out some of the tests described in this standard it is necessary for a reference sample to b

15、e supplied or agreed by the parties concerned (see clause4). A choice of method for density determination is given in8.2.1. For the British Standard the preferred method is ISO787-23 for which there is an identical British Standard (see above). A related British Standard to ISO787-10 is BS3483-B8:19

16、82 Determination of density (pyknometer method). A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal oblig

17、ations. International Standard Corresponding British Standard ISO 3219:1977 BS 2782 Methods of testing plastics Method 730B:1978 Determination of the viscosity of polymers in the liquid, emulsified or dispersed state using a rotational viscometer working at a defined shear rate (Identical) ISO 3262:

18、1975 BS 1795:1976 Specification for extenders for paints (Identical) BS 6782 Binders for paints ISO 3682:1983 Part 3:1987 Method for determination of acid value (titrimetric method)d) (Identical) ISO 4629:1978 Part 4:1987 Method for determination of hydroxyl value (titrimetric method) (Identical) Su

19、mmary of pages This document comprises a front cover, an inside front cover, pages i to iv, theENISOtitle page, pages 2 to 14, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment

20、table on the inside front cover.iv blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 787-24 August 1995 ICS 87.060.10 Descriptors: Paints, pigments, tests, determination, colouring power, photometric method English version General methods of test for pigments and extenders Part24:Determi

21、nation of relative tinting strength of coloured pigments and relative scattering power of white pigments Photometric methods (ISO 787-24:1985) Mthodes gnrales dessai des pigments et matires de charge Partie 24: Dtermination du pouvoir colorant relatif des pigments colors et du pouvoir diffusant rela

22、tif des pigments blancs Mthodes photomtriques (ISO 787-24:1985) Allgemeine Prfverfahren fr Pigmente und Fllstoffe Teil 24: Bestimmung der relativen Farbstrke von Buntpigmenten und des relativen Streuvermgens von Weipigmenten Photometrische Verfahren (ISO 787-24:1985) This European Standard was appro

23、ved by CEN on1995-03-23. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national stand

24、ards 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 of a CEN member into its own language and notified to

25、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, Spain, Sweden, Switzerland and UnitedKingdom. CEN Eu

26、ropean Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 All rights of reproduction and communication in any form and by any means reserved in all countries to CEN and its members Ref. No. EN ISO

27、787-24:1995 EENISO787-24:1995 2 BSI 03-2000 Foreword The text of the International Standard from ISO/TC35, Paints and varnishes, of the International Organization for Standardization (ISO) has been taken over as a European Standard by the Technical Committee CEN/TC298, Pigments and extenders. This E

28、uropean Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February1996, and conflicting national standards shall be withdrawn at the latest by February1996. According to the CEN/CENELEC Internal Regulations, the

29、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 the UnitedKingdom. NOTENormative references to international publications

30、 are given inAnnex ZA (normative). Contents Page Foreword 2 0 Introduction 3 1 Scope and field of application 3 2 References 3 3 Definitions 3 4 Principle 4 5 Materials and equipment 5 6 Apparatus 5 7 Sampling 6 8 Procedure 6 9 Expression of results 7 10 Test report 7 Annex A Reflectivity and absorp

31、tion and scattering coefficients 8 Annex B K/S values as a function of measured Zor R Z 9 Annex ZA (normative) Normative references to international publications with their relevant European publications 14ENISO787-24:1995 BSI 03-2000 3 0 Introduction This document is a part of ISO787, General metho

32、ds of test for pigments and extenders. 1 Scope and field of application This part of ISO787 describes photometric methods of test for comparing in the visible spectrum a) the tinting strength of two similar (see note 1) coloured pigments dispersed in an alkyd resin without a drier; b) the scattering

33、 power of two white pigments of the same type dispersed in an alkyd resin without a drier. These methods of test provide an instrumental alternative to those described in ISO787-16 and ISO787-17 respectively, avoiding the necessity of visual matching. NOTE 1This International Standard is not appropr

34、iate for the comparison of coloured pigments that on reduction differ greatly in colour. NOTE 2When one of these general methods is applicable to a given pigment, only a cross-reference to the appropriate method should be included in the International Standard relating to that pigment, indicating an

35、y detailed modification which may be needed in view of the special properties of the product in question. Only when the appropriate method in this part of ISO787 is not applicable to a particular product should different photometric methods for determination of relative tinting strength and determin

36、ation of relative scattering power be specified. 2 References ISO 591, Titanium dioxide pigments for paints. ISO 787, General methods of test for pigments and extenders Part 2: Determination of matter volatile at105 C Part 9: Determination of pH value of an aqueous suspension Part 10: Determination

37、of density Pyknometer method Part16:Determination of relative tinting strength (or equivalent colouring value) and colour on reduction of coloured pigments Visual comparison method Part 17: Comparison of lightening power of white pigments Part 23: Determination of density (using a centrifuge to remo

38、ve entrained air). ISO 842, Raw materials for paints and varnishes Sampling. ISO 1524, Paints and varnishes Determination of fineness of grind. ISO 3219, Plastics Polymers in the liquid, emulsified or dispersed state Determination of viscosity with a rotational viscometer working at defined shear ra

39、te. ISO 3262, Extenders for paints. ISO 3682, Binders for paints and varnishes Determination of acid value Titrimetric method. ISO 4629, Binders for paints and varnishes Determination of hydroxyl value Titrimetric method 1) . ISO 4652, Rubber compounding ingredients Carbon black Determination of spe

40、cific surface area Nitrogen adsorption methods. ISO 6209, Rubber compounding ingredients Carbon black Determination of solvent extractable material. 3 Definitions 3.1 For coloured and black pigments 3.1.1 tinting strength the ability of a pigment (see the note) to absorb incident light, thereby havi

41、ng the power to colour or darken, for example, a white paint in which it is incorporated NOTEAlthough the properties tested are strictly those of the pigmented binder, absorption and scattering by the binder are relatively small and it is assumed in this International Standard that the material unde

42、r test is the dispersed pigment. 3.1.2 spectral absorption coefficient K() the fraction of the diffusely incident spectral radiant flux of wavelength that is absorbed in an elementary layer within a material, divided by the thickness of the layer (Kubelka-Munk analysis) NOTEK() is a measure of the t

43、inting strength of coloured pigments in a material and is expressed in units of reciprocal film thickness. 3.1.3 absorbance index K p () the spectral absorption coefficient of the pigmented binder divided by the pigment concentration C m : where C mis the pigment concentration, for example, expresse

44、d as the ratio by mass of pigment to binder 3.1.4 relative tinting strength K r () the ratio of the absorbance index of the test sampleK p1 () to that of an agreed reference pigmentK p2 (), expressed as a percentage: 1) In course of preparation. (Revision of ISO4629:1978.) . . . (1) . . . (2)ENISO78

45、7-24:1995 4 BSI 03-2000 3.2 For white pigments 3.2.1 scattering power the ability of a pigment (see the note to3.1.1) to diffuse incident light, thereby having the power to confer opacity and lightness to, for example, a paint in which it is incorporated 3.2.2 spectral scattering coefficient S() the

46、 net transfer of spectral radiant flux of wavelength in the outward direction from an elementary layer within a body of material illuminated from outside, divided by the product of the thickness of the layer and the difference between the magnitude of the flux in the two directions through the layer

47、 (Kubelka-Munk analysis) NOTES() is a measure of the scattering power of white pigments in a material and is expressed in units of reciprocal film thickness. 3.2.3 scattering index S p () the spectral scattering coefficient of the pigmented binder divided by the pigment concentration C m(see3.1.3):

48、3.2.4 relative scattering power S r () the ratio of the scattering index of the test sample S p3 () to that of an agreed reference pigment S p4 (), expressed as a percentage: 3.3 reflectivity Z the reflectance of a paste or a paint film of such thickness that further increase in thickness gives no f

49、urther change in reflectance the reflectivity , corrected according to equation(10), is related to K/S by the equation values of K/S as a function of100 Zor100 R Zare given inAnnex B NOTE 1Kubelka-Munk analysis is strictly applicable only to monochromatic radiation, as indicated in equations(1) to(4). In practice, however, correct results are often also obtained if the mean value for wider wavebands is taken, as is the case when filters are used. Hence, in the subsequent equations