Isoprene rubber (IR)

40.02 - Synthetic rubber and factice derived from oils, in primary forms or in plates, sheets or strip; mixtures of any product of heading 40.01 with any product of this heading, in primary forms or in plates, sheets or strip. - S ene-butadiene (%m) : 4002.1 1 4002.19 rubber (SBR); carboxylated styrene-butadiene rubber - - Latex - - Other 4002.20 - Butadiene rubber (BR) - Isobutene-isoprene (CIIR or BTIR) : 4002.3 1 4002.39 (butyl) rubber (IIR); halo-isobutene-isoprene rubber - - Isobutene-isoprene (butyl) rubber (IR) - - Other - CbIoroprene (chlorobutadiene) rubber (CR) : 4002.41 4002.49 4002.5 1 - - Latex - - Other - Acrylonitrile-butadiene rubber (NBR) : - - Latex 4002.59 - - Other 4002.60 - Isoprene rubber (IR) 4002.70 4002.80 4002.91 4002.99 - Ethylene-propylene-non-conjugateddiene rubber (EPDM) - Mixtures of any product of heading 40.01 with any product of this heading - Other : - - Latex - - Other This heading covers : Fc 1 ) Synthetic rubber as defined in Note 4 to this Chapter (see below). This includes s rubber latex, whether or not pre-vulcanised, and synthetic rubber m other primary o m or in plates, sheets or strip. The heading also covers synthetic rubber which has been treated oses of trans ort and preservation or with a view to obtaining particular the p? esigned to faci itate its subsequent use or to improve the qualities of the end properties product. Such treatment must not, however, alter its essential character as a raw material. In particular it must not contain any substance forbidden by Note 5 (A) to this Chapter. Among the products which have been corn ounded but which are not excluded from this heading by the rovisions of Note 5 are J e oil-extended rubbers; these contain up to approximately 5 % of oil. a (2) Factice derived from oils - Factice is the product of the reaction of certain vegetable or fish oils (whether or not oxidised or partly hydrogenated) with sulphur or sulphur chloride. Factice is physically weak and is used mainly compounded with natural or synthetic rubber, and also for the manufacture of erasers. (3) Intermixtures of any of the foregoing products. (4) Mixtures of any product of heading 40.01 with any product of this heading. Note 4 (Definition of synthetic rubber) This Note is in three parts. Whereas substances of Part vulcanisation, elongation and recovery criteria mentioned exempt from these re uirements. It should be noted that applies not only to hea ing 40.02 but also to Note 1. Conse used in the Nomenclature, it includes synthetic rubber as The expression " synthetic rubber " covers : (a) Unsaturated synthetic substances, which meet the re uirements concerning vulcanisation, elongation and recovery as laid down in Part (a? of the Note. For the purposes of the test, substances necessary for the cross-linking, such as vulcanising actrvators, accelerators or retarders may be added. The presence of small amounts of breakdown roducts of emulsifiers (Note 5 (B) (ii)) and very small amounts of the special purpose ad tives mentioned in Note 5 (B) (iii) is also permitted. However, the presence of any substances not necessary for the cross-linking, such as pigments other than those added solely for the purpose of identification), plasticisers, extenders,!i llers, reinforcin a ents, organic solvents is not permitted. Thus, the presence of mineral oil or diocty p thalate is not permitted for the purpose of the test. ‘I? t P Accordingly, in the case of substances containing materials not permitted by Note 4, such as mineral oil, the test is to be carried out on a sample which does not contain such materials or from which such materials have been removed. In the case of vulcanised articles, which cannot be tested as such, it is necessary to obtain a sample of the unvulcanised raw material from which the articles are made, in order to perform the test. (b) Thioplasts (TIM) which are saturated synthetic substances, obtained by the reaction of aliphatic dialides with a sodium olysulphide; they are generally vulcanisable with the classical-type wlcanising agents. &e mechanical pro erties of certain types of thioplasts are inferior to those of the other grades of synthetic ru ber but the have the advantage of being resistant to solvents. These should not be confused witK the polysulphides of heading 39.11 (see the Explanatory Note to that heading). ! (c) The products listed below, rovided that they comply with the conditions described in paragraph (a) above in regar to vulcanisation, elongation and recovery : 'f (1) Modified natural rubber, obtained by grafting or mixing rubber with plastics. Such rubber is usually obtained by fixing a polymerisable monomer onto the rubber by usin a polymerisation catalyst or by co-precipitation of a natural rubber latex with a syntfletic polymer latex. The main characteristic of modified natural rubber is that it is to a certain extent" self-reinforcing ", its properties in this respect being similar to those of a mixture of natural rubber and carbon black. (2) De-polymerised natural rubber, obtained by mechanical processing (pounding) at a given temperature. (3) Mixtures of unsaturated synthetic substances with saturated s thetic high polymers (e.g., mixtures of acrylonitrile-butadiene rubber and poly(viny chloride). !? This heading excludes : (a) Elastomers which do not comply with the conditions laid down in Note 4 to this Chapter (generally Chapter 39). @) The products of this headin compounded, before or after coagulation, with substances forbidden by Note 5 (A) to this Chapter (teading 40.05 or 40.06).