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1、BRITISH STANDARD BS 3279:1960 Specification for Seedlac Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 08:12:00 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3279:1960 This British Standard, having been approved by the Pigments, Paints and Varnishes Industry Standards Committee and endorsed
2、by the Chairman of the Chemical Divisional Council, was published under the authority of the General Council on 31 October 1960 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference PVC/4 Draft for comment A(PVC) 3701 ISBN 0 580 34075 9 Co-operating organi
3、zations The Pigments, Paints and Varnishes Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Admiralty Air Ministry Association of British Chemic
4、al Manufacturers Board of Trade* British Colour Makers Association British Railways, The British Transport Commission Building Industry Distributors Crown Agents for Oversea Governments and Administrations D.S.I.R. Building Research Station D.S.I.R. Laboratory of the Government Chemist* Incorporated
5、 Institute of British Decorators Lead Oxide Convention London County Council Ministry of Aviation* Ministry of Works National Paint Federation Oil and Colour Chemists Association* Paint Manufacturers and Allied Trades Association Post Office Research Association of British Paint, Colour and Varnish
6、Manufacturers Royal Institute of British Architects Society of British Paint Manufacturers Ltd.* Titanium Pigment Manufacturers Technical Committee White Lead Convention Zinc Development Association Zinc Pigment Development Association The Government departments and scientific and industrial organiz
7、ations marked with an asterisk in the above list, together with the following, were directly represented on the Committee entrusted with the preparation of this British Standard: British Electrical and Allied Industries Research Association British Electrical and Allied Manufacturers Association Bri
8、tish Hat and Allied Feltmakers Research Association London Chamber of Commerce, Incorp. London Shellac Trade Association Society for Analytical Chemistry Tropical Products Institute Individual manufacturers Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffield
9、un, na, Wed Nov 29 08:12:00 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3279:1960 BSI 12-1999i Contents Page Co-operating organizationsInside front cover Forewordii 1Scope1 2Description1 3Sample1 4Volatile matter1 5Matter insoluble in hot alcohol1 6Expression of analytical results1 7Colour index1
10、8Matter soluble in water1 9Non-volatile matter soluble in cold alcohol2 10Wax2 Appendix A Sampling3 Appendix B Method for the determination of volatile matter3 Appendix C Method for the determination of matter insoluble in hot alcohol5 Appendix D Method for the determination of colour index7 Appendi
11、x E Method for the determination of non-volatile matter soluble in cold alcohol7 Appendix F Method for the determination of matter soluble in water8 Appendix G Method for the determination of wax9 Figure 1 Siphon tube and adaptor4 Figure 2 Folding of filter paper6 Licensed Copy: sheffieldun sheffiel
12、dun, na, Wed Nov 29 08:12:00 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3279:1960 ii BSI 12-1999 Foreword This standard makes reference to the following British Standards: BS 410, Test sieves. BS 1957, Presentation of numerical values (fineness of expression; rounding of numbers). During recent y
13、ears, lac has been studied internationally through the International Organization for Standardization (ISO), by various Research Institutions and Trade Organizations in different parts of the world. It has been decided to split the subject matter of BS 954, the previous British Standard for all type
14、s of lac other than bleached lac, into three parts, covering seedlac, hand-made shellac and machine-made shellac, and to publish these as separate documents. Advantage has been taken of the work done at the ISO level, and the Committee responsible for the preparation of this standard desires to ackn
15、owledge its indebtedness to the sources of information thus utilized. The usual trade descriptions of the various grades of seedlac, as recognized in the United Kingdom, have been used throughout. These trade descriptions are well known internationally, and are recognized standards of the London She
16、llac Trade Association. An attempt has been made, however, to correlate these with the designations of the Recommendations of the International Organization for Standardization: the approximate correspondence for seedlac is as follows: The mandatory requirements included in this specification are th
17、ose for appearance and colour, volatile matter (moisture) and matter insoluble in hot alcohol, and methods of test are given for these. Also included are optional clauses and methods of test, operative only by agreement between purchaser and vendor, for colour index, matter soluble in water, non-vol
18、atile matter soluble in cold alcohol, and wax. It will be noted that no requirements have been given for a “bleach test” or “bleachability” or for the absence of visible impurities. In the opinion of the Committee, work is not yet in a sufficiently advanced state to allow of the former, and visible
19、impurities are effectively limited by the provisions of Clauses 2 and 5. 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 i
20、mmunity from legal obligations. Approximate U.K. gradingISO grading Golden KusmiSpecial Kusmi No. IA Kusmi No. 2B Golden BysackiC Fine BysackiD No equivalentE Ordinary BysackiF Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 9 and a back cove
21、r. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 08:12:00 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3279:1960 BSI 12-199
22、91 Mandatory clauses 1 Scope This British Standard specifies requirements for seedlac, the product obtained by washing crushed sticklac, the natural product of the lac insect (Laccifer lacca). Unless otherwise agreed between purchaser and vendor, the seedlac shall be of Indian origin and shall be of
23、 the crop implied by the grade name employed. Six grades are specified, as follows: Golden Kusmi Kusmi No. 1 Kusmi No. 2 Golden Bysacki Fine Bysacki Ordinary Bysacki 2 Description The form and condition of the material shall be as agreed between purchaser and vendor. The appearance and colour of the
24、 material shall be not inferior to those of an agreed sample, when judged by visual examination. 3 Sample For the purpose of examination under this specification samples shall be drawn, parted and prepared in the manner described in Appendix A. Only original unopened packages of shellac shall be sam
25、pled. Not less than 10 per cent of the packages, selected at random from each lot of not more than 200 packages, shall be sampled. 4 Volatile matter The material shall not yield more than 2.5 per cent by weight of volatile matter when tested in the manner described in Appendix B. 5 Matter insoluble
26、in hot alcohol The material shall not contain more than the following specified limits of matter insoluble in hot alcohol, when tested in the manner described in Appendix C. By agreement between purchaser and vendor this limit may be relaxed but under no circumstances shall it exceed the relaxed lim
27、it. 6 Expression of analytical results The results of analyses performed in accordance with the appendices to this standard shall be expressed to the number of significant figures indicated in the specification requirements. The principles embodied in BS 1957, “Presentation of numerical values (fine
28、ness of expression; rounding of numbers)”, apply to such results. Optional clauses 7 Colour index When agreed between purchaser and vendor, the colour index of the material shall not exceed the following limits when determined in the manner described in Appendix D: 8 Matter soluble in water When agr
29、eed between purchaser and vendor, the material shall not contain more than 1.0 per cent by weight of matter soluble in water, when determined in the manner described in Appendix F. GradeLimitRelaxed limit per cent by weight Golden Kusmi2.04.0 Kusmi No. 1 Kusmi No. 23.05.0 Golden Bysacki Fine Bysacki
30、3.06.0 Ordinary Bysacki5.08.0 GradeLimit Golden Kusmi 8Kusmi No. 1 Kusmi No. 210 Golden Bysacki15 Fine Bysacki22 Ordinary Bysacki50 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 08:12:00 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3279:1960 2 BSI 12-1999 9 Non-volatile matter soluble in c
31、old alcohol When agreed between purchaser and vendor, the material shall contain not less than the following amounts of non-volatile matter soluble in cold alcohol, when tested in the manner described in Appendix E: 10 Wax When agreed between purchaser and vendor, the material shall not contain more
32、 than 5.5 per cent by weight of wax, when determined in the manner described in Appendix G. GradeLimit per cent by weight Golden Kusmi90.0 Kusmi No. 1 89.0 Kusmi No. 2 Golden Bysacki Fine Bysacki Ordinary Bysacki87.0 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 08:12:00 GMT+00:00 2006, Unc
33、ontrolled Copy, (c) BSI BS 3279:1960 BSI 12-19993 Appendix A Sampling Drawing of samples Free-flowing seedlac. Take samples from different places in each package by means of a suitable tryer so as to yield a total of 5 kg (or 10 lb) of material consisting of approximately equal portions from each pa
34、ckage sampled. Thoroughly mix the material and heap and quarter along two diameters which intersect at right angles. Mix two opposite quarters and preserve in air-tight containers, seal and label as the “Original observation sample”. If necessary, further sub-divide by quartering to form a number of
35、 original observation samples. Part the other two quarters of the material as described below to form the analysis sample. Blocky or matted seedlac. Take small pieces not more than 1.2 in (3 cm) across from different places in each package by chipping or other suitable means so as to yield a total o
36、f 5 kg (or 10 lb) of material consisting of approximately equal portions from each package sampled. Thoroughly mix the material and heap and quarter along two diameters which intersect at right angles. Mix two opposite quarters and preserve in air-tight containers, seal and label as the “Original ob
37、servation sample”. If necessary, further sub-divide by quartering to form a number of original observation samples. Part the other two quarters of the material as described below to form the analysis sample. Preparation of samples Thoroughly mix the material obtained above, and heap and quarter alon
38、g two diameters which intersect at right angles. Mix two opposite quarters and grind the mixture to pass entirely through an 8 mesh BS test sieve1). Thoroughly mix and twice divide by quartering into four samples, each of approximately 300 g (or 11 oz). Place these samples in air-tight containers, s
39、eal and label each as “Analysis sample”. a) Sample for determination of volatile matter. Grind an adequate amount (40 to 50 g) of the “Analysis sample” to pass entirely through an 18 mesh BS test sieve1), taking all precautions to avoid loss of volatile matter. Place in an air-tight container and la
40、bel “Sample for volatile matter determination”. b) Prepared sample for all determinations other than volatile matter. Grind an adequate amount of the “Analysis sample” to pass entirely through a 36 mesh BS test sieve1). Transfer to an air-tight container and label as “Prepared sample for all determi
41、nations other than that for volatile matter”. Appendix B Method for the determination of volatile matter Principle The volatile matter content is determined by heating a weighed portion of the sample at 41 1 C for 4 hours and then keeping it over concentrated sulphuric acid in vacuo for 18 hours. Pr
42、ocedure Weigh, to an accuracy of 0.0005 g, a clean, dry, flat-bottomed dish of about 75 mm diameter, provided with a ground glass cover. Transfer about 2 g of the sample reserved for this purpose (see Appendix A) into the dish and re-weigh to the same accuracy. Place the dish and its cover separatel
43、y in a well-ventilated oven maintained at 41 1 C for 4 hours. At the end of this period, transfer the dish and cover to a vacuum desiccator containing concentrated sulphuric acid. Immediately evacuate the desiccator and continue drying in vacuo for 18 hours. Remove the dish and immediately replace t
44、he cover and weigh to an accuracy of 0.0005 g. Express the loss in weight as a percentage of the weight of the sample taken. Calculation 1) BS 410, “Test sieves”. Volatile water, per cent by weight where W= weight in grammes of sample taken, andW1= weight in grammes of sample after drying. 100WW1()
45、W - -= Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 08:12:00 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3279:1960 4 BSI 12-1999 Dimensions in millimetres Figure 1 Siphon tube and adaptor Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 08:12:00 GMT+00:00 2006, Uncontrolled Copy, (
46、c) BSI BS 3279:1960 BSI 12-19995 Appendix C Method for the determination of matter insoluble in hot alcohol Apparatus a) Siphon tube2), of glass, of the Knoefler type, having minimum internal dimensions of 52 mm height and 32 mm diameter, resting in an adaptor tube in such a way that the siphon tube
47、 is surrounded by the ascending vapours of the boiling solvent (Figure 1). b) Condenser, of any convenient pattern. c) Flask, of any convenient size. d) Filter paper, 12.5 cm diameter, medium grade3). e) Weighing bottles, of glass, height 80 1 mm, diameter 40 1 mm with ground glass stoppers. Assembl
48、y of apparatus Assemble the siphon tube, adaptor, condenser and flask, using corks or ground glass joints, so that the solvent can be kept boiling in the flask and its vapour passed upwards, by way of the adaptor, to the condenser and the refluxing solvent run from the condenser into the cup of the
49、siphon tube. Reagent Alcohol, 95 per cent (v/v) ethanol or 95 per cent (v/v) industrial methylated spirit4). Procedure Fold a filter paper so that it forms a completely closed envelope, as illustrated in Figure 2. Mark this paper, S, for sample: wrap it closely in a second filter paper marked C, for counterpoise. Separate the filter papers and dry in an oven at 100 2 C for 30 minutes. Rapidly transfer to weighing bottles which have been kept in a desiccator over concentrated sulphuric aci