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1、BRITISH STANDARD CONFIRMED SEPTEMBER 1993 BS 4725:1987 ISO 276:1981 Specification for Linseed stand oil for paints and varnishes ISO title: Linseed stand oil for paints and varnishes Specifications and methods of test UDC 667.6:665.345.4 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:1
2、3 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4725:1987 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 on 30 November 1987 BSI 12-1999 First publi
3、shed April 1971 First revision November 1987 The following BSI references relate to the work on this standard: Committee reference PVC/3 Draft for comment 80/50278 DC ISBN 0 580 16190 0 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Pig
4、ments, Paints and Varnishes Standards Committee (PVC/-) to Technical Committee PVC/3, upon which the following bodies were represented: British Resin Manufacturers Association Fosfa International Oil and Colour Chemists Association Overseas Development Administration Tropical Development and Researc
5、h Institute Paint Research Association Paintmakers Association of Great Britain Ltd. Seed Crushers and Oil Processors Association Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2006, Uncontrolled Copy, (c) B
6、SI BS 4725:1987 BSI 12-1999i Contents Page Committees responsibleInside front cover National forewordii 1Scope and field of application1 2References1 3Definition1 4Required characteristics and their tolerances1 5Sampling1 6Viscosity2 7Polybromide test2 8Test for the presence of blown oils3 9Test rep
7、ort3 Table Required characteristics and their tolerances2 Publications referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4725:1987 ii BSI 12-1999 National foreword This British Standard has been prepared under t
8、he direction of the Pigments, Paints and Varnishes Standards Committee. It is identical with ISO 276:1981 “Linseed stand oil for paints and varnishes Specifications and methods of test”, published by the International Organization for Standardization (ISO). This revision supersedes BS 4725:1971, whi
9、ch is withdrawn. BS 4725 was first published in 1971 and this first revision brings the standard into line with international agreements by dual-numbering the ISO standard which was based on the British Standard. The main changes in this edition are as follows: a) the viscosity ranges of the five ty
10、pes of oil have been amended; b) the methods of test refer to separately published methods or are included in the main text rather than appendices; c) the polybromide test is only applied to the extra low viscosity grade. Terminology and conventions. The text of the International Standard has been a
11、pproved as suitable for publication as a British 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 curren
12、t practice to use a full point on the baseline as the decimal marker. The symbol “l” has been used to denote litre (and its submultiples). In British Standards it is current practice to use the symbol “L”. Wherever the words “International Standard” or “International Standard (ISO 276)” appear, refe
13、rring to this standard, they should be read as “British Standard” and “British Standard (BS 4725)” respectively. Additional information. In order to carry out some of the tests in this standard it is necessary for a reference sample and for certain conditions and test methods to be supplied or agree
14、d by the parties concerned (see the Table). Referring to the requirements for viscosity (see Table) the non-preferred units of poise are given in parentheses and are for information. The values given for 25 C are also for information and are used in countries where the lower temperature is difficult
15、 to maintain. For the purposes of this British Standard the temperature of 23 C and the measurement in pascal seconds should be used. The recommended method of measurement (see clause 6) is that described in BS 3900 “Methods of test for paints” Part A7 “Determination of the viscosity of paint at a h
16、igh rate of shear”, except that the test should be carried out at 23 C. This method currently records the result in poise and should be converted using the relationship 1 poise = 10 1 Pas. BS 3900-A7 will be revised when the revision of the equivalent ISO standard is available. Cross-references Inte
17、rnational StandardCorresponding British Standard ISO 150:1980BS 6900:1987 Specification for raw, refined and boiled linseed oils for paints and varnishes (Identical) ISO 842:1984BS 4726:1986 Methods for sampling raw materials for paints and varnishes (Identical) BS 6782 Binders for paints ISO 3681:1
18、983Part 2:1987 Method for determination of saponification value (titrimetric method) (Identical) ISO 3682:1983Part 3:1987 Method for determination of acid value (titrimetric method) (Identical) Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI
19、 BS 4725:1987 BSI 12-1999iii 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 obligations. Summary of p
20、ages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 4, 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 table on the inside front cover
21、. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4725:1987 BSI 12-19991 1 Scope and field of application This Internation
22、al Standard specifies the requirements and the corresponding methods of test for five types of linseed stand oil suitable for paints and varnishes. 2 References ISO 150, Raw, refined and boiled linseed oil for paints and varnishes Specifications and methods of test. ISO 842, Raw materials for paints
23、 and varnishes Sampling. ISO 3681, Paint media Determination of saponification value Titrimetric method. ISO 3682, Paint media Determination of acid value Titrimetric method. 3 Definition linseed stand oil polymerized linseed oil obtained from linseed oil by heat treatment and conforming to the requ
24、irements given below NOTECertain of these materials are also referred to as “lithographic varnishes”. 4 Required characteristics and their tolerances The five types of linseed stand oils shall have the characteristics shown in the Table. 5 Sampling Take a representative sample of the oil as describe
25、d in ISO 842. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4725:1987 2 BSI 12-1999 Table Required characteristics and their tolerances Methods of test During the analyses, use only reagents of recognized analytical grade and only disti
26、lled water or water of equivalent purity. 6 Viscosity Any method for measuring the dynamic viscosity of liquids may be used. 7 Polybromide test 7.1 Reagents 7.1.1 Sulphuric acid, 196 g/l solution. 7.1.2 Potassium hydroxide, 56 g/l ethanolic solution. 7.1.3 Sodium sulphate, anhydrous. 7.1.4 Bromine 7
27、.1.5 Diethyl ether, 20 0,712 to 0,716 g/ml, yielding a non-volatile residue at 80 C of not more than 0,001 % (m/m). 7.1.6 Light petroleum (petroleum ether), boiling range 40 to 60 C. 7.2 Preparation of the fatty acids Saponify about 15 g of the oil with 70 ml of the ethanolic potassium hydroxide sol
28、ution (7.1.2) by boiling for 1 h under reflux. Characteristic Requirement Test method Stand oil 1 extra low viscosity Stand oil 2 low viscosity Stand oil 3 medium viscosity Stand oil 4 high viscosity Stand oil 5 extra high viscosity ViscosityClause 6 at 23C Pas P max. 0,9 (max. 9) 0,9 to 3,4 (9 to 3
29、4) 3,4 to 6,8 (34 to 68) 6,8 to 13 (68 to 130) min. 13 (min. 130) (at 25C) Pas P max. 0,8 (max. 8) 0,8 to 3 (8 to 30) 3 to 6 (30 to 60) 6 to 11 (60 to 110) min. 11 (min. 110) Clarity and colour To be agreed between the interested parties To be agreed between the interested parties To be agreed betwe
30、en the interested parties To be agreed between the interested parties To be agreed between the interested parties a OdourSimilar to that of a reference sample agreed between the interested parties Similar to that of a reference sample agreed between the interested parties Similar to that of a refere
31、nce sample agreed between the interested parties Similar to that of a reference sample agreed between the interested parties Similar to that of a reference sample agreed between the interested parties a Ash, max. % (m/m) 0,100,100,100,100,10ISO 150 Acid value, gKOH/kg max. 610121520ISO 3682 Saponifi
32、cation value gKOH/kg 186 to 200186 to 200186 to 200186 to 200186 to 200ISO 3681 Unsaponifiable matter, max. % (m/m) 2,02,02,02,02,0ISO 150 Polybromide test Negative result Clause 7 Test for presence of colophony (rosin) Negative result Negative result Negative result Negative result Negative result
33、ISO 150 Test for presence of blown oils Negative result Negative result Negative result Negative result Negative result Clause 8 a The method should be agreed between the interested parties. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS
34、 4725:1987 BSI 12-19993 Transfer the soap solution to a porcelain dish and, after addition of 50 ml of hot water, expel the ethanol by evaporating on a steam bath. Dissolve the soap in 50 ml of hot water, transfer to a beaker of 500 ml and acidify with 25 ml of the sulphuric acid solution (7.1.1). B
35、oil the solution whilst passing a slow current of carbon dioxide through it, until the layer of fatty acids is clear. Allow to cool to room temperature, add 150 ml of the light petroleum (7.1.6). Filter the light petroleum layer through anhydrous sodium sulphate (7.1.3) (the filtrate should not cont
36、ain water). Evaporate the solvent on the steam bath, removing the last traces with a slow current of carbon dioxide. 7.3 Procedure 7.3.1 Dissolve 1 g of the fatty acids (7.2) in 10 ml of diethyl ether, (7.1.5), and cool to 10 C in a 100 ml conical flask fitted with a ground glass stopper. Carefully
37、add 0,3 ml of bromine (7.1.4) whilst stirring the mixture. Swirl the mixture thoroughly. Place the flask in an ice water bath and allow to stand for 5 min at 0 C, until any sediment present has settled. Experience has shown that one of the following phenomena takes place: a) a crystalline sediment i
38、s produced (see 7.3.2); b) a crystalline sediment and dark emulsion are produced (see 7.3.3); c) a dark emulsion is formed (see 7.3.4); d) the solution is clear (see 7.3.4). 7.3.2 As the immediate formation of a crystalline sediment reveals the presence of linseed oil or another non-polymerized poly
39、bromide-forming oil, report the test as being positive. 7.3.3 If, in addition, an emulsion or a heavy liquid layer is formed on the bottom of the flask, as usually occurs in the case of stand oil of higher viscosity, add 5 ml of diethyl ether at 0 C and swirl the flask again in the ice water bath, i
40、n order to facilitate the detection and identification of the crystalline sediment. If this is not sufficient to dissolve the heavy liquid phase, make further additions of 5 ml of cold diethyl ether and cool again until the heavy liquid layer dissolves. Finally, examine the contents of the flask aga
41、in. If a crystalline sediment is present, report the test as being positive. 7.3.4 If only a dark emulsion of a heavy liquid layer is formed on the bottom of the flask, or if the solution is clear, allow the mass to stand in the ice water bath for 12 to 16 h. If crystals are formed after this period
42、, remove the liquid phase by additions of diethyl ether (5 ml at a time, as in 7.3.3), and examine again for the presence of crystals. If a clear solution is obtained and a crystalline sediment is not observed, the absence of linseed oil or an amount too small for detection is indicated. Report the
43、test as being negative. 7.4 Limit of sensitivity The presence of about 4 to 4,5 % (m/m) of linseed oil in linseed stand oil is detected immediately when using the procedure specified in 7.3.2 and 7.3.3. The presence of less than 4 % (m/m) of linseed oil may be detected by carrying out the procedure
44、specified in 7.3.4. The test described in 7.3.4 gives a negative result if the proportion of linseed oil present is less than about 2 to 3 % (m/m). NOTEBoth the polybromides of fish oil fatty acids and the hexabromides from the linolenic acid of linseed oil, form a crystalline sediment. 8 Test for t
45、he presence of blown oils Mix thoroughly in a 50 ml measuring cylinder fitted with a ground glass stopper, 10 ml of stand oil and 30 ml of the light petroleum (7.1.6). The solution should be clear. If after 3 days storage at room temperature the solution shows no deposit, report the test as being ne
46、gative. 9 Test report The test report shall contain at least the following information: a) the type and identification of the product tested; b) a reference to this International Standard (ISO 276); c) the results of the tests, and whether or not the product complies with the relevant specification
47、limits; d) any deviation, by agreement or otherwise, from the procedures specified; e) the date of the tests. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 4 blank Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2
48、006, Uncontrolled Copy, (c) BSI BS 4725:1987 BSI 12-1999 Publications referred to See national foreword. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 09:03:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 4725:1987 ISO 276:1981 BSI 389 Chiswick High Road London W4 4AL BSI British Standards
49、 Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while usin