![]() ![]() Original Assignee Battelle Memorial Institute Inc Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)īattelle Memorial Institute Geneva Research Center Nguyen Gunter Bellmann Francoise Boussel Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Expired - Lifetime Application number US06/598,351 Inventor Van T. Google Patents Low viscosity stable aqueous dispersion of graft carbon blackĭownload PDF Info Publication number US4530961A US4530961A US06/598,351 US59835184A US4530961A US 4530961 A US4530961 A US 4530961A US 59835184 A US59835184 A US 59835184A US 4530961 A US4530961 A US 4530961A Authority US United States Prior art keywords carbon black dispersion water particles grafted Prior art date Legal status (The legal status is an assumption and is not a legal conclusion. Google Patents US4530961A - Low viscosity stable aqueous dispersion of graft carbon black This would certainly result in heterogeneous crosslink distribution which would manifest itself in physical properties and possibly in some “chemical properties” of the reinforced vulcanizates.US4530961A - Low viscosity stable aqueous dispersion of graft carbon black Agglomeration of carbon black particles plus high crosslink density seems to be strongly indicated. After the dehydrogenation step, polymerization reactions, as described in this issue by Craig, should also be considered as possible. This activity directs the chemical reactions of vulcanization to the α-methylene carbon atom and may lead directly to coupling rather than addition reactions at the double bond. This probably involves chemisorption with dissociation of α-methylene hydrogen atoms. In the initial phases of vulcanization, its activity as a dehydrogenation catalyst is of considerable importance. 7) As a catalyst which promotes a type of decomposition of TMTD, and no doubt other systems, in a manner which is efficient in producing crosslinks. ![]() 6) As a catalyst in the presence of oxidizing agents for the conversion of hydrogen sulfide (and sulfanes) to sulfur. 5) As a catalyst for hydrogen sulfide formation (associated with 1, above) which is apparently necessary, at least under some conditions, to activate curing systems. (This particular activity has not been demonstrated it is suggested in this review only as a possibility.) 4) As a catalyst in activating accelerators by breaking -S-S- linkages, as in TMTD, -S-(S) x-S- linkages in the MBT polysulfide product of Dogadkin and Tutorskii˘, -S-N- linkages in Santocure, NOBS Special, etc. 3) As a catalyst to convert polysulfides to disulfides or prevent polysulfide formation. 2) As a catalyst for the oxidation of -SH intermediates to -S-S- crosslinks. During cure, carbon black may be considered to act in some, if not all, of the following ways: 1) As a catalyst for dehydrogenation by sulfur. During vulcanization, the action of carbon black will be dependent upon the nature of the rubber, the nature of the curing system and the presence of other compounding ingredients. Insofar as addition to carbon black is involved, the results of a) and c) are, for practical purposes, identical. c) Chemisorption of rubber molecules with dissociation-dehydrogenation-and chemical combination of the rubber-free radicals so formed with the carbon black surface or with themselves, a type of polymerization. b) Isomerization of the double bond structure of rubber molecules resulting in conjugation. ![]() This would be a case of alkylation of an aromatic material by an olefin. When carbon black is heated with rubber, as during hot mixing or during cure, the following types of reaction are considered possible: a) Alkylation (in a broad sense) of carbon black by rubber molecules. However, in some cases the chemical reactivity seems to be associated with catalytic activity. Much of the chemical reactivity results in removal of molecules or reactive intermediates which might otherwise produce crosslinks. In this discussion, we have indicated that carbon blacks display both chemical and catalytic activity which appear to be sufficient to radically alter the chemistry of vulcanization. ![]()
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