Abstract: A mixture of polycyclic, aromatic polycarboxylic acids carrying nuclear nitro groups that is substantially soluble in a mixture of polar solvents but substantially insoluble in water and a process for preparing the mixture of polycyclic, aromatic polycarboxylic acids.

Abstract: A process for the production of aromatic dialdehydes which comprises reacting xylene chloride selected from the group consisting of .alpha.,.alpha.,.alpha.'-trichloroxylene alone, or a mixture of .alpha.,.alpha.,.alpha.'-trichloroxylene and .alpha.,.alpha.'-dichloroxylene, a mixture of .alpha.,.alpha.,.alpha.'-trichloroxylene and .alpha.,.alpha.,.alpha.',.alpha.'-tetrachloroxylene and a mixture of .alpha.,.alpha.,.alpha.'-trichloroxylene, .alpha.,.alpha.'-dichloroxylene and .alpha.,.alpha.,.alpha.',.alpha.'-tetrachloroxylene with nitric acid.

Abstract: A drilling fluid containing a new composition of matter resulting from the reaction of (1) substantially water-insoluble polycyclic, polycarboxylic acids obtained as a result of the oxidation of coal with (2) a base.

Abstract: A novel isomeric mixture of benzophenone pentacarboxylic acids and their anhydrides.

Abstract: An apparatus for producing an aromatic dicarboxylic acid by oxidizing a benzene derivative with molecular oxygen in the liquid phase in a lower aliphatic carboxylic acid as a solvent in the presence of an oxidation catalyst, wherein a starting material liquid e.g., a benzene derivative or a solution thereof in the lower aliphatic carboxylic acid, is fed into the liquid-phase reaction system in a uniformly dispersed state by being passed through a porous material causing the pressure of the starting material liquid just after passing through said porous material to drop more than about 1 kg/m.sup.2 in relation to the pressure of the starting material liquid just before passing through said porous material. The resultant aromatic dicarboxylic acid has high purity and has good color.

Abstract: A mixture of polycyclic aromatic polycarboxylic anhydrides carrying nuclear nitro groups that is substantially soluble in acetone but substantially insoluble in water and a process for preparing the mixture.

Abstract: A mixture of polycyclic aromatic polycarboxylic acids that is substantially insoluble in acetone and substantially insoluble in water and a process for preparing the mixture.