Abstract: In a process for the production of carbon fibers from high boiling bituminous substances in which a purified and polymerized concentrated carbon fiber precursor is spun into fibers which are oxidized and then carbonized and optionally graphitized, the improvement comprising adding to the carbon fiber precursor just before spinning 2 to 10% by weight of a solvent in which the precursor is insoluble or only slightly soluble under normal conditions and mixing the resulting mixture under hypercritical conditions for the solvent for at least 10 minutes without gas or solid inclusions formed in the fiber and neoformatgion of solids is prevented.

Abstract: In a process for the production of carbon fibers from high boiling bituminous substances in which a purified and polymerized concentrated carbon fiber precursor is spun into fibers which are oxidized and then carbonized and optionally graphitized, the improvement comprising just before spinning a supercritical gas is dissolved in mesophase pitch at a pressure of 100 to 350 bars and a temperature up to 150.degree. K. below the melting temperature of the mesophase pitch to form a low viscosity melt, separating the latter into an isotropic phase and an anisotropic carbon fiber precursor and spinning the latter into fibers whereby the spinning temperature is lowered and the mesophase contact is increased due to the viscosity lowering activity of the supercritical gas.

Abstract: A method of removing salts from coal tar and coal pitches comprising washing coal tar or coal pitch in a pressure container with water and a carbon dioxide containing gas at a temperature and pressure near the critical point of the gas in the optional presence of at least one member of the group consisting of a solvent and an entraining agent, removing the liquid or dissolved tar or pitch to obtain tar or pitch with a low salt content and removing the aqueous phase whereby all the resins remain in the tar or pitch.

Abstract: Coal tar oil is separated quantitatively into neutral oil, phenols and bases by a two stage extraction with overcritical gases. Carbon dioxide is employed as an overcritical extraction agent, and propane or butane are preferably added as entrainers. The neutral oil is obtained in the first stage. Tar bases can be employed as an additional entrainer for improving the selectivity. The bases are extracted in the second stage. The method is associated with the advantage that it saves energy and that no byproducts are generated.

Abstract: A process for the production of pitch raw materials having improved properties comprising extracting coal-tar pitch free of solids with a mixture of a supercritical gas extracting agent and an entrainer at elevated temperatures and pressures, passing the extraction mixture to a plurality of separation steps where the supercritical gas and entrainer are removed by lowering the pressure and/or raising the temperature, recycling the mixture of extracting agent and entrainer to the extraction step and recovering the pitch fractions from the separation step, the said pitch fractions being useful for diverse purposes such as soot production, electrode bonding agents, etc.

Abstract: A method for the production of a carbon fiber precursor from coal tar pitch comprising extracting coal tar pitch at elevated temperatures and pressures with a mixture of a supercritical gas and an entraining agent to obtain a solution free of quinoline-insoluble components, recovering from the solution by lowering the pressure and/or raising the temperature to obtain at least one fraction selected from the group consisting of quinoline-soluble fraction and toluene-soluble fraction, treating the said fraction(s) at 380.degree. to 450.degree. C. under a non-oxidizing atmosphere at atmosphere pressure until 40 to 65% by volume of the product is converted into pitch containing mesophase, extracting the latter pitch with a mixture of supercritical gas and an entraining agent to remove isotropic pitch and recovering isotropic pitch with a mesophase content of at least 75% by volume, a pyridine-insoluble matter content of 20 to 50% by weight, a mean molecular weight of 900 to 1200 and a melting point of 330.degree.

Abstract: Stable phenolic-modified hydrocarbon resins with an OH number which is 4.5 or greater are resonably priced and toxicologically generally regarded as safe resins for the development of leucopigments, especially for the development of colors in pressure sensitive recording materials. The softening point may be varied by copolymerization with multivalent phenolic compounds and vinyl phenol within the range of 70.degree.-90.degree. C.

Abstract: Aromatic hydrocarbon resins are disclosed prepared from aromatic, unsaturated hydrocarbons and a melted aromatic carboxylic acid polymerized in the presence of a Friedel-Crafts catalyst. The resin may be used in printing inks, for paper sizing, for coatings and other applications where natural resins have been used.

Abstract: Phenolic-modified hydrocarbon polymers with a high OH-number yet with excellent compatibility with non-polar solvents are suitable for preparing adhesives and coating materials. The polymers are obtained by isothermal, catalytic copolymerization of:30-40% by weight phenolic compounds,65-30% by weight aromatic, unsaturated hydrocarbons, and5-30% by weight isobutene.