GB859433A - Process for the bleaching of waxes or wax-like materials by oxidation and the new compositions of matter thus obtained - Google Patents

Abstract

A process for bleaching waxes, or mixtures thereof with fatty acids comprises adding at least one partial oxidation product of one or more hydrocarbons that are solid at room temperature, and then bleaching the homogeneous mixture at an elevated temperature, usually 90 DEG -130 DEG C., with chromosulphuric acid (i.e. a solution of chromium trioxide in sulphuric acid). The partially oxidized hydrocarbon, which is suitably a partially oxidized paraffin wax or polyethylene, may constitute up to 80% of the mixture, but is usually 10-70%, most of the oxygen present being contained in hydroxyl groups ; the oxidized hydrocarbon preferably has both an acid value and a hydroxyl value of 10-80. The chain length of this oxidized material is the longer the more carbon atoms are contained in the chain in the wax and acid. The wax and oxidized hydrocarbon may both be crude products, and the preferred wax is crude Montan wax, although carnauba, ouricuri, and candellila wax, beeswax, cane wax, peat wax may also be treated, if required in the presence of fatty acids such as behenic or arachidic acid. The bleached product may be esterified with monohydric alcohols having at least 15 carbon atoms or with polyhydric alcohols and then suitably partially neutralized with an alkaline earth hydroxide or with zinc oxide or hydroxide, whereby the hardness of the product is increased.ALSO:A process for bleaching waxes, or mixtures thereof with fatty acids comprises adding at least one partial oxidation product of one or more hydrocarbons that are solid at room temperature, and then bleaching the homogeneous mixture at an elevated temperature, usually 90-130 DEG C., with chromosulphuric acid (i.e. a solution of chromium trioxide in sulphuric acid). The partially oxidized hydrocarbon which is suitably a partially oxidized paraffin wax or polyethylene, may constitute up to 80% of the mixture, but is usually 10-70%, most of the oxygen present being contained in hydroxyl groups; the oxidized hydrocarbon preferably has both an acid value and a hydroxyl value of 10-80. The chain length of this oxidized material is the longer the more carbon atoms are contained in the chain in the wax and acid. The wax and oxidized hydrocarbon may both be crude products, and the preferred wax is crude Montan wax, although carnauba, ouricuri, and candellila wax, beeswax, cane wax, peat wax may also be treated if required in the presence of such fatty acids as behenic or arachidic acid. The bleached product may be esterified with monohydric alcohols having at least 15 carbon atoms or with polhydric alcohols, and then suitably partially neutralized with an alkaline earth hydroxide or with zinc oxide or hydroxide, whereby the hardness of the product is increased.