| 摘要 |
1348850 Modified carbon black AGENCE NATIONALE DE VALORISATION DE LA RECHERCHE 25 June 1971 [26 June 1970] 29944/71 Heading C1A [Also in Division C3] Polymeric materials are grafted on to carbon black by mixing the black with a polymer, degassing the mixture of carbon black and polymer, introducing to the mixture a solvent for the polymer and forming a solution thereof, stirring and heating the mixture in the solvent until by a free radical mechanism polymer grafts are attached to the carbon black. The black used may be furnace black, thermal black, or channel black. The polymer used may be a graft copolymer, a block copolymer, a block homopolymer, or a polymer mixture. Preferably, a polymer having hydrogen on a tertiary carbon atom is used. Polystyrene, polyvinylacetate, polypropylene, polymethylmethacrylate, an acrylonitrile-styrene copolymer, polyvinyl chloride or a propylene based copolymer are given as suitable polymers. The solvent may be introduced into the mixture by condensing it from the vapour state on to the mixture. The solvent used may be an aromatic hydrocarbon, an ether, or in a preferred embodiment, the monomeric form of the polymer is used. Styrene, acrylonitrile, a mixture of the last two, and vinyl acetate are given as suitable materials. The mixture may be degassed at ambient temperature by the application of subatmospheric pressure, and the solvent may be distilled and condensed at this same pressure to form the desired solution containing carbon black, which is heated with stirring to at least 50‹ C. to produce the desired product. The product may be separated from the unused polymer by filtration or by centrifuge. Times, temperatures and pressures suitable for the process are given and claimed. The blacks produced are easily dispersed and find use in paints, varnishes and printing inks, and are improved as pigments, ultraviolet filters, fillers and antioxidants. The amount of polymer on the black varies between 1À2% and 11À5% by weight. |
