1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 2475:2011Chloroprene rubber (CR) General-purpose types Evaluation procedureBS ISO 2475:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation
2、 of ISO 2475:2011. Itsupersedes BS ISO 2475:1999 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/50, Rubber - Raw, natural and synthetic, includinglatex and carbon black.A list of organizations represented on this committee can beobtained on request
3、 to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 69693 0ICS 83.060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard wa
4、s published under the authority of theStandards Policy and Strategy Committee on 30 November 2011.Amendments issued since publicationDate Text affectedBS ISO 2475:2011Reference numberISO 2475:2011(E)ISO 2011INTERNATIONAL STANDARD ISO2475Fifth edition2011-11-01Chloroprene rubber (CR) General-purpose
5、types Evaluation procedure Caoutchouc chloroprne (CR) Types usage gnral Mthode dvaluation BS ISO 2475:2011ISO 2475:2011(E) COPYRIGHT PROTECTED DOCUMENT ISO 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, ele
6、ctronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso
7、.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 2475:2011ISO 2475:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references 1 3 Sampling and sample preparation . 2 4 Physical and chemical tests on raw rubber . 2 4.1 Mooney
8、viscosity . 2 4.2 Volatile matter 2 4.3 Ash 2 5 Sulfur-modified chloroprene rubbers Preparation of the test mix for evaluation . 2 5.1 Standard test formulation . 2 5.2 Procedure . 3 6 Mercaptan-modified chloroprene rubbers Preparation of the test mix for evaluation 4 6.1 Standard test formulation .
9、 4 6.2 Procedure . 5 7 Preparation of the test mix for evaluation of sulfur-modified or mercaptan-modified chloroprene with miniature internal mixer (MIM) . 7 7.1 Standard test formulations . 7 7.2 Procedure . 7 8 Evaluation of vulcanization characteristics by a curemeter test . 8 8.1 Using an oscil
10、lating-disc curemeter 8 8.2 Using a rotorless curemeter . 8 9 Evaluation of tensile stress-strain properties of vulcanized test mixes . 8 10 Precision 9 11 Test report 9 Annex A (informative) Precision statement 10 Bibliography 12 BS ISO 2475:2011ISO 2475:2011(E) iv ISO 2011 All rights reservedForew
11、ord ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a techni
12、cal committee has been established 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. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of e
13、lectrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to
14、the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for i
15、dentifying any or all such patent rights. ISO 2475 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw materials (including latex) for use in the rubber industry. This fifth edition cancels and replaces the fourth edition (ISO 2475:1999), in which: the n
16、ormative references have been updated; the precision data (Clause 10) have been moved to informative Annex A. It also incorporates the Amendment ISO 2475:1999/Amd.1:2005 and the Technical Corrigendum ISO 2475:1999/Cor.1:2001. BS ISO 2475:2011INTERNATIONAL STANDARD ISO 2475:2011(E) ISO 2011 All right
17、s reserved 1Chloroprene rubber (CR) General-purpose types Evaluation procedure WARNING Persons using this International Standard should be familiar with normal laboratory practice. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the respon
18、sibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions. 1 Scope This International Standard specifies, for general-purpose chloroprene rubbers (CRs): physical and chemical tests on raw rubbers; standard materials, st
19、andard test formulations, equipment and processing methods for evaluating the vulcanization characteristics. General-purpose chloroprene rubbers fall into three broad classes based on the type of polymerization modifier used in their preparation: a) sulfur-modified types; b) mercaptan-modified types
20、; c) types modified by other products. For class c), the procedure for either a) or b) may be followed. 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 references, the
21、latest edition of the referenced document (including any amendments) applies. ISO 37, Rubber, vulcanized or thermoplastic Determination of tensile stress-strain properties ISO 247, Rubber Determination of ash ISO 248-1:2011, Rubber, raw Determination of volatile-matter content Part 1: Hot-mill metho
22、d and oven method ISO 289-1, Rubber, unvulcanized Determinations using a shearing-disc viscometer Part 1: Determination of Mooney viscosity ISO 1795, Rubber, raw natural and raw synthetic Sampling and further preparative procedures ISO 2393, Rubber test mixes Preparation, mixing and vulcanization Eq
23、uipment and procedures BS ISO 2475:2011ISO 2475:2011(E) 2 ISO 2011 All rights reservedISO 3417, Rubber Measurement of vulcanization characteristics with the oscillating disc curemeter ISO 6502, Rubber Guide to the use of curemeters ISO 23529, Rubber General procedures for preparing and conditioning
24、test pieces for physical test methods 3 Sampling and sample preparation 3.1 Take a sample of mass approximately 1,5 kg by the method described in ISO 1795. 3.2 Prepare the test portion in accordance with ISO 1795. 4 Physical and chemical tests on raw rubber 4.1 Mooney viscosity Determine the Mooney
25、viscosity in accordance with ISO 289-1, on a test portion prepared as indicated in 3.2. Record the result as ML(1 + 4) at 100 C. 4.2 Volatile matter Determine the volatile-matter content in accordance with ISO 248-1:2011, either by the oven method or, if the rubber is in a suitable form (which is no
26、t the case if it is in chip or powder form), the hot-mill method, but with a mill roll temperature of 50 C 5 C. 4.3 Ash Determine the ash in accordance with ISO 247. 5 Sulfur-modified chloroprene rubbers Preparation of the test mix for evaluation 5.1 Standard test formulation The standard test formu
27、lation is given in Table 1. The materials shall be national or international standard reference materials, unless no standard reference materials are available, in which case the materials to be used shall be agreed between the interested parties. BS ISO 2475:2011ISO 2475:2011(E) ISO 2011 All rights
28、 reserved 3Table 1 Standard test formulation for evaluation of sulfur-modified chloroprene rubbers Material Parts by mass Chloroprene rubber (CR), sulfur-modified 100,00 Stearic acida0,50Magnesium oxideb4,00Carbon blackc25,00Zinc oxided5,00Total 134,50 aSee ISO 8312. bThe surface area of the magnesi
29、um oxide shall be between 130 m2/g and 200 m2/g. Magnesium oxide absorbs water and carbon dioxide when exposed to air and this can affect its activity in compounds. Store it in a dry environment. cThe current industry reference black (IRB), or an equivalent national or international standard referen
30、ce material, shall be used. dClass B1a (see ISO 9298:1995, Annex D). 5.2 Procedure 5.2.1 Equipment and procedure The equipment and procedure for preparation, mixing and vulcanization shall be in accordance with ISO 2393. 5.2.2 Premastication 5.2.2.1 Weigh out 500 g of chloroprene rubber. 5.2.2.2 Adj
31、ust the mill-roll temperature to 50 C 5 C. 5.2.2.3 Band the rubber with a mill opening of 1,5 mm and start the timer at the instant the rubber is banded. 5.2.2.4 Adjust the nip to maintain a rolling bank of approximately 12 mm in diameter. Mill the rubber for 6 min, cutting as necessary to maintain
32、a rolling bank and a tight band. 5.2.2.5 Remove the rubber from the mill and allow it to cool to room temperature prior to mixing. 5.2.3 Mill mixing procedure The standard laboratory mill batch mass shall be based on four times the recipe mass in grams. The surface temperature of the rolls shall be
33、maintained at 50 C 5 C throughout the mixing. A good rolling bank at the nip of the rolls shall be maintained during mixing. If this is not obtained with the nip settings specified hereunder, small adjustments to the mill opening might be necessary. BS ISO 2475:2011ISO 2475:2011(E) 4 ISO 2011 All ri
34、ghts reservedDuration (min) a) Band the premasticated rubber on the mill with a nip setting of 1,5 mm or a suitable setting to maintain a rolling bank .1,0 b) Add the stearic acid . 1,0 c) Add the magnesium oxide slowly, spreading it evenly over the entire width of the band. Ensure complete incorpor
35、ation before adding the carbon black .2,0 d) Add the carbon black. Open the nip at intervals to maintain a rolling bank. Sweep up and add any material which has fallen into the pan 5,0 e) Add the zinc oxide . 2,0 f) Make three 3/4 cuts from each side 2,0 g) Cut the batch from the mill. Set the nip a
36、t 0,8 mm and pass the rolled batch lengthways through the mill six times .2,0 Total time 15,0 h) Sheet the batch to an approximate thickness of 6 mm and check-weigh the batch (see ISO 2393). If the mass of the batch differs from the theoretical value by more than +0,5 %/1,5 %, discard the batch and
37、re-mix. Remove sufficient material for curemeter testing. i) Sheet the batch to an approximate thickness of 2,2 mm for preparing test slabs or to the appropriate thickness for preparing ISO ring specimens in accordance with ISO 37. j) Condition the batch for 2 h to 24 h after mixing and prior to vul
38、canizing, if possible at standardtemperature and humidity as defined in ISO 23529. 6 Mercaptan-modified chloroprene rubbers Preparation of the test mix for evaluation 6.1 Standard test formulation The standard test formulation is given in Table 2. The materials shall be national or international sta
39、ndard reference materials, unless no standard reference materials are available, in which case the materials to be used shall be agreed between the interested parties. BS ISO 2475:2011ISO 2475:2011(E) ISO 2011 All rights reserved 5Table 2 Standard test formulations for evaluation of mercaptan-modifi
40、ed chloroprene rubbersaMaterial Formulation A (parts by mass) Formulation B (parts by mass) Chloroprene rubber (CR), mercaptan-modified 100,00 100,00 Magnesium oxideb4,00 4,00Carbon blackc25,00 25,00Zinc oxided5,00 5,00MTT 80 in polymeric binder (curative)e0,45 Sulfur 1,00Di-ortho-tolyl guanidine (D
41、OTG)f1,00 N-cyclohexyl-2-benzothiazyl sulfenamide (CBS) 1,00 Total 134,45 137,00aThe CR test formulation contains 3-methylthiazolidinethione-2 (MTT) (in the case of formulation A) or sulfur/DOTG/CBS (in the case of formulation B) instead of ethylene thiourea, a suspected carcinogen. bThe surface are
42、a of the magnesium oxide shall be between 130 m2/g and 200 m2/g. Magnesium oxide absorbs water and carbon dioxide when exposed to air and this can affect its activity in compounds. Store it in a dry environment. cThe current industry reference black (IRB), or an equivalent national or international
43、standard reference material, shall be used. dClass B1a (see ISO 9298:1995, Annex D). eMTT 80 can be obtained from Rhein Chemie Rheinau GmbH, Mlheimer Str. 24-28, D-68219 Mannheim 81, Germany.This information is given for the convenience of users of this International Standard and does not constitute
44、 an endorsement by ISO of this product. fUnder some conditions, DOTG might generate o-toluidine emissions classified as carcinogenic by the International Agency for Research on Cancer. Avoid exposure to emissions during curing of mixes. 6.2 Procedure 6.2.1 Equipment and procedure The equipment and p
45、rocedure for the preparation, mixing and vulcanization shall be in accordance with ISO 2393. 6.2.2 Premastication 6.2.2.1 Weigh out 500 g of chloroprene rubber. 6.2.2.2 Adjust the mill-roll temperature to 50 C 5 C. 6.2.2.3 Band the rubber with a mill opening of 1,5 mm and start the timer at the inst
46、ant the rubber is banded. 6.2.2.4 Adjust the nip to maintain a rolling bank of approximately 12 mm in diameter. Mill the rubber for 6 min, cutting as necessary to maintain a rolling bank and a tight band. 6.2.2.5 Remove the rubber from the mill and allow it to cool to room temperature prior to mixin
47、g. BS ISO 2475:2011ISO 2475:2011(E) 6 ISO 2011 All rights reserved6.2.3 Mill mixing procedure The standard laboratory mill batch mass shall be based on four times the recipe mass in grams. The surface temperature of the rolls shall be maintained at 50 C 5 C throughout the mixing. A good rolling bank
48、 at the nip of the rolls shall be maintained during mixing. If this is not obtained with the nip settings specified hereunder, small adjustments to the mill opening might be necessary. Duration (min) a) Band the premasticated rubber on the mill with a nip setting of 1,5 mm or a suitable setting to m
49、aintain a rolling bank .1,0 b) Add the magnesium oxide slowly, spreading it evenly over the entire width of the band. Ensure complete incorporation before adding the carbon black .2,0 c) Add the carbon black. Open the nip at intervals to maintain a rolling bank. Sweep up and add any material which has fallen into the pan 5,0 d) Add the zinc oxide . 2,0 e) If using formulation A, add the MTT 80 . 1,0 If using formulation B, add the sulfur, DOTG and CBS .
