The precipitated silica of the invention is characterised by: The size of the particles of the precipitated silica disclosed in FR2997405 does not meet the criterion expressed by formula (I) hereunder. 7,070,749 does not disclose the size of the silica particles measured by means of centrifugal sedimentation in a disc centrifuge.įR2997405 discloses compositions comprising a Ti-doped precipitated silica in combination with selected phosphinate/phosphonate coupling agents. 7,070,749, which discloses foreign-atom-doped precipitated silicas suitable for use in papermaking applications. Ti, Zr, V, Sc) has been previously described, for instance in U.S. Precipitated silica containing transition metals (e.g. d50, measured by centrifugal sedimentation, with respect to its CTAB surface area. It has been found that good mechanical properties and reduced energy dissipation (hence heat build-up) in elastomeric compositions can be obtained by the use of a precipitated silica containing at least one metal M selected from the group consisting of the elements of groups 3, 4 and 5 in an amount of at least 0.1 mol % and having a large a median particle size. These objectives are achieved by the inventive precipitated silica defined in detail in the description which follows and in the claims and the examples. A further objective of the invention is to provide elastomeric compositions comprising the precipitated silica as reinforcing filler. A second objective of the invention is a process for the manufacture of the precipitated silica. SUMMARY OF INVENTIONĪ first objective of the present invention is to provide novel precipitated silica which, when incorporated efficiently into polymeric compositions, provides an improved balance of performance properties. Indeed there is always the need of precipitated silica capable of providing a balance between conflicting properties such as abrasion resistance and/or polymer reinforcement on one hand and reduced energy dissipation properties, which in turn provide for reduced heat build-up, on the other. In general, precipitated silica is used in order to improve the mechanical properties of the elastomeric composition as well as abrasion performance. Such use is highly demanding: the filler has to readily and efficiently incorporate and disperse in the elastomeric composition and, typically in conjunction with a coupling reagent, enter into a chemical bond with the elastomer(s), to lead to a high and homogeneous reinforcement of the elastomeric composition. In particular it is known to use precipitated silica as reinforcing filler in elastomeric compositions. The use of precipitated silica as a reinforcing filler in polymeric compositions is known. The present invention relates to precipitated silica and to a process for its manufacture.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |