Abstract: A process for preparing a sterically hindered 3,5-dialkyl-4-hydroxybenzoic acid which comprises reacting a sterically hindered 2,6-dialkylphenol with an excess of sodium hydride or lithium hydride in a dry dipolar aprotic solvent, carboxylating the resulting anhydrous phenolate with an excess of carbon dioxide at atmospheric pressure and at a temperature of about 70.degree. C. to 80.degree. C., then destroying the excess sodium hydride or lithium hydride by addition of an alcohol, followed by acidifying the reaction mixture to obtain a high yield of the sterically hindered 3,5-dialkyl-4-hydroxybenzoic acid.

Abstract: This invention relates to polymer compositions containing light stabilizing amounts of an ester of a phosphinodithioic acid.

Abstract: N,N,N',N'-tetraarylquinone diimonium salt infrared absorbers of improved heat stability are prepared by oxidizing an N,N,N',N'-tetraarylquinonediamine with a cupric salt, such as cupric chloride or cupric nitrate, rather than a silver salt as heretofore.