1、July 2011 Translation by DIN-Sprachendienst.English price group 7No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 83
2、.180!$sAx“1803085www.din.deDDIN EN 1243Adhesives Determination of free formaldehyde in amino and amidoformaldehydecondensatesEnglish translation of DIN EN 1243:2011-07Klebstoffe Bestimmung des freien Formaldehydgehaltes in Amino- undAmido-Formaldehyd-KondensatenEnglische bersetzung von DIN EN 1243:2
3、011-07Adhsifs Dtermination du formald hyde libre dans les condensats de formaldhyde amino etamidoTraduction anglaise de DIN EN 1243:2011-07SupersedesDIN EN 1243:1999-05www.beuth.deIn case of doubt, the German-language original shall be considered authoritative.Document comprises 8 pages06.11 DIN EN
4、1243:2011-07 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 193 “Adhesives” (Secretariat: AENOR, Spain). The responsible German bodies involved in its preparation was the Normenausschuss Kunststoffe (Plastics Standards Committ
5、ee), Working Committee NA 054-04-06 AA Klebstoffe Terminologie; physikalisch-chemische Prfungen. The DIN Standards corresponding to the International Standards referred to in this document are as follows: EN ISO 3696 DIN ISO 3696 ISO 648 DIN EN ISO 648 Amendments This standard differs from DIN EN 12
6、43:1999-05 as follows: a) the foreword now includes a “Safety Statement” and an “Environmental Statement”; b) Clause 2 “Normative references” has been updated: EN ISO 15605, Adhesives Sampling (ISO 15605:2000) has been added; EN 1066, Adhesives Sampling has been deleted; EN 923:2005+A1:2008, EN ISO
7、3696:1995, ISO 385-1:1984 and ISO 648:2008 are now dated references; c) Clause 5 “Safety” has been deleted; d) the standard has been editorially revised. Previous editions DIN EN 1243: 1999-05 National Annex NA (informative) Bibliography DIN EN ISO 648, Laboratory glassware Single-volume pipettes DI
8、N ISO 3696, Water for analytical laboratory use Specification and test methods EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1243 April 2011 ICS 83.180 Supersedes EN 1243:1998English Version Adhesives - Determination of free formaldehyde in amino and amidoformaldehyde condensates Adhsifs - Dt
9、ermination du formaldhyde libre dans les condensats de formaldhyde amino et amido Klebstoffe - Bestimmung des freien Formaldehydgehaltes in Amino- und Amido-Formaldehyd-Kondensaten This European Standard was approved by CEN on 10 March 2011. CEN members are bound to comply with the CEN/CENELEC Inter
10、nal 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 standards may be obtained on application to the CEN-CENELEC Management Centre or to any
11、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 the CEN-CENELEC Management Centre has the same status as the official ver
12、sions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, S
13、lovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CE
14、N national Members. Ref. No. EN 1243:2011: EEN 1243:2011 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Principle 45 Reagents .46 Apparatus .57 Sampling .58 Procedure .59 Expression of results 610 Test report 6DIN EN 1243:2011-07 EN 1243:2011 (E) 3 Forewor
15、d This document (EN 1243:2011) has been prepared by Technical Committee CEN/TC 193 “Adhesives”, the secretariat of which is held by AENOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2
16、011, and conflicting national standards shall be withdrawn at the latest by October 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent righ
17、ts. This document supersedes EN 1243:1998. The main modifications regarding the previous version are in the Foreword, Normative References and Clause 4. SAFETY STATEMENT Persons using this document should be familiar with the normal laboratory practice, if applicable. This document does not purport
18、to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any regulatory conditions. ENVIRONMENTAL STATEMENT It is understood that some of the material permitted in t
19、his standard may have negative environmental impact. As technological advantages lead to acceptable alternatives for these materials, they will be eliminated from this standard to the extent possible. At the end of the test, the user of the standard should take care to carry out an appropriate dispo
20、sal of the wastes, according to local regulation. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland,
21、France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 1243:2011-07 EN 1243:2011 (E) 4 1 Scope This European Standard specifies a me
22、thod for the determination of the free formaldehyde content in amino and amido-formaldehyde condensate adhesives. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated refere
23、nces, the latest edition of the referenced document (including any amendments) applies. EN 923:2005+A1:2008, Adhesives Terms and definitions EN 1067, Adhesives Examination and preparation of samples for testing EN ISO 1042:1999, Laboratory glassware One-mark volumetric flasks (ISO 1042:1998) EN ISO
24、3696:1995, Water for analytical laboratory use Specification and test methods (ISO 3696:1987) EN ISO 15605, Adhesives Sampling (ISO 15605:2000) EN ISO 385:2005, Laboratory glassware Burettes (ISO 385:2005) ISO 648:2008, Laboratory glassware Single-volume pipettes (ISO 648:2008) 3 Terms and definitio
25、ns For the purposes of this document, the terms and definitions given in EN 923:2005+A1:2008 and the following apply. 3.1 free formaldehyde percentage (m/m) of unreacted formaldehyde in the product 4 Principle Reaction of the free formaldehyde with sodium sulphite, in the presence of a measured exce
26、ss of acid, in accordance with the reaction: CH2O + Na2SO3+ H2O CH2(OH)SO3Na + NaOH and alkaline titration of the unreacted excess acid. The acid-sulphite mixture provides an essentially neutral buffered system which prevents hydrolysis of condensed formaldehyde. A reaction temperature close to 0 C
27、helps to ensure the absence of side reactions. 5 Reagents 5.1 Hydrochloric acid, aqueous 0,5 M standard volumetric solution. NOTE Sulphuric acid 0,25 M can be used as an alternative. DIN EN 1243:2011-07 EN 1243:2011 (E) 5 5.2 Sodium sulphite, aqueous 1 M solution. 5.3 Hydrochloric acid, aqueous 0,1
28、M solution in sodium sulphite. The solution shall be freshly prepared by mixing 80 ml of sodium sulphite solution (5.2) with 20 ml of hydrochloric acid 0,5 M solution (5.1). NOTE Sulphuric acid can be used as an alternative. 5.4 Sodium hydroxide, aqueous 0,1 M standard volumetric solution. 5.5 Dimet
29、hylsulphoxide, aqueous 50 % v/v solution, or other solvents such as ethyleneglycol. NOTE When using a solvent different from dimethylsulphoxide, preliminary comparative tests should be carried out to check possible side reactions. 5.6 Thymolphthalein, 0,1 % m/v solution in ethanol 5.7 Deionized or d
30、istilled water, grade 3 as specified in EN ISO 3696:1995. 6 Apparatus 6.1 Ordinary laboratory apparatus All volumetric glassware shall be class A, conforming to EN ISO 385:2005, ISO 648:2008 or EN ISO 1042:1999 as appropriate. 6.2 Analytical balance, accurate to within 0,1 g. 6.3 Conical flask, capa
31、city 300 ml. 6.4 Ice and water bath. 7 Sampling Take a significant sample of the adhesive to be tested in accordance with EN ISO 15605. Homogenize as described in EN 1067. 8 Procedure 8.1 Disperse solid adhesives in water (5.7) at 50 % m/m and carry out the analysis within 2 h. Where the solid adhes
32、ive is a formulated type (with fillers and acid catalyst), neutralize the dispersion with sodium hydroxide (5.4) before the analysis. The neutralization of formulate adhesive dispersion shall be done in the following way: Weight the amount of dispersion to analyse and add sodium hydroxide (5.4) till
33、 pH 7,0 0,2 and record the volume used (Vx). Throw away the sample. Weigh the same amount of another sample of dispersion, add the volume of sodium hydroxide Vxand proceed as described in 8.2, 8.3 and 8.4. 8.2 Weigh, to the nearest 0,1 g, in a 300 ml conical flask (6.3) 5 g of liquid adhesive or dis
34、persion (8.1); add 50 ml of dimethylsulphoxide solution (5.5) previously cooled and put the flask in the ice and water bath (6.4) for 20 min (internal temperature 5 C). DIN EN 1243:2011-07 EN 1243:2011 (E) 6 8.3 Add rapidly, within 5 s, and whilst stirring, 30 ml of hydrochloric acid 0,1 M solution
35、in sodium sulphite (5.3) previously cooled in the ice and water bath (6.4); wait 5 min to ensure complete reaction of the formaldehyde with sulphite; add 1 ml of thymolphthalein solution (5.6) and titrate immediately (in less than 1 min) the excess of acid with the sodium hydroxide 0,1 M solution (5
36、.4) to the blue colour change. Record the volume, V1, of the sodium hydroxide solution used, in millilitres. NOTE A potentiometric titration can be used if the temperature and the time conditions are respected. 8.4 Carry out a blank test under the same conditions, but without the adhesive, and note
37、the volume V2, in millilitres, of sodium hydroxide solution used. NOTE If the difference V2- V1is lower than 3 ml, the analysis should be repeated weighing a larger quantity of adhesive (i.e. 10 g). 9 Expression of results The free formaldehyde content shall be calculated by the following formula: F
38、ree formaldehyde % = m3,002 M )V(V12where V1is the volume, in millilitres, of 0,1 M sodium hydroxide solution (5.4) used for the adhesive test; V2is the volume, in millilitres, of 0,1 M sodium hydroxide solution (5.4) used for the blank test; M is the molarity of sodium hydroxide solution (5.4); m i
39、s the mass, in grams, of the adhesive test portion. NOTE For the solid adhesives “m“ is of the test portion (50 % dispersion). 10 Test report The test report shall include: a) reference to this European Standard, i.e EN 1243; b) the type and designation of the adhesive tested; c) the result of the test expressed in accordance with Clause 9; d) any modification to the procedure described and any circumstances affecting the result; e) date of the test. DIN EN 1243:2011-07
