Abstract: A pitch having optical anisotropy for use in production of carbon fibers, wherein the pitch is prepared using a compound represented by the formula (I) as a raw starting material and subjecting the compound to thermal modification and then removing light fractions ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 each represents a hydrogen atom or a methyl group or an ethyl group; R.sub.5 represents a hydrogen atom or a methyl group; the total number of carbon atoms of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is from 2 to 4 and the total number of carbon atoms of R.sub.6, R.sub.7, R.sub.8 and R.sub.9 is from 2 to 4; and m is at least 3. The pitch is substantially homogeneous in quality, has a low softening point and has excellent molecular orientation.

Abstract: A composition useful as a paper sizing agent comprising a substituted succinic anhydride of the formula: ##STR1## wherein R is a hydrocarbon group having at least 6 carbon atoms selected from the group consisting of an alkyl group, an alkenyl group, an aralkyl group or an aralkenyl group,and a non-ionic surface active agent having a terminal hydroxyl group bonding to tertiary carbon. The composition has excellent storage stability, and can exhibit an excellent sizing effect even if stored for a long term.

Abstract: A pitch is disclosed which is used as a raw material for making carbon fibers. The pitch has a quinoline insoluble content of 7-18% by weight and a toluene insoluble content of 70-90% by weight. Further, the pitch preferably has a n-heptane soluble content of 1.0% by weight or less. A process for producing the pitch is also disclosed. The process comprises carrying out thermal modification of a petroleum heavy residual oil having a boiling point of 400.degree. C. or more (atmospheric pressure) and a sulfur content of 1.5% by weight or less. Insoluble substances are then separated and removed by heating at a temperature of 380.degree. C. or less. Thereafter, a low boiling point fraction is removed by vacuum distillation. The pitch can be utilized to producd carbon fibers without breaking of filaments in spinning or adhesion by fusion of the fibers in infusibilization. The carbon fibers produced have a high tensile strength and high modulus of elasticity.

Abstract: A process for producing a pitch is disclosed. The process involves distilling a heavy petroleum oil under reduced pressure to obtain a distillate, the distillate is hydrogenated to obtain a hydrogenated oil which is subjected to catalytic cracking. The cracked oil is subjected to distillation to obtain a high boiling point fraction having a boiling point of more than 300.degree. C. The high boiling point fraction is subjected to thermal modification in order to obtain the pitch. The pitch can be utilized in order to produce carbon fibers of high quality. By utilizing the process a greater variety of starting materials can be utilized in order to produce the pitch which is utilized to produce high quality carbon fibers.

Abstract: A process for producing a pitch which is used as a raw material for producing carbon fibers is disclosed. The process comprises subjecting a petroleum heavy residual oil to hydrogenation treatment in the presence of catalysts, removing a low boiling point fraction of the oil by reduced pressure distillation, subjecting the resulting reduced pressure distillation residual oil to solvent extraction treatment, and carrying out thermal modification of the resulting extraction component.By utilizing the process for producing the pitch it is possible to use a wide variety of different types of oils in order to produce carbon fibers. The carbon fibers produced from the pitch produced according to the disclosed process have desirable characteristics.

Abstract: A process for producing a pitch used as a raw material for producing carbon fibers is disclosed. The process comprises the steps of carrying out catalytic cracking of a hydrogenated residual oil prepared by hydrogenation treatment of a petroleum heavy residual oil or a mixture composed of said hydrogenated residual oil and a hydrogenated distillate oil which is prepared by hydrogenation treatment of a reduced pressure distillate oil prepared by reduced pressure distillation of the petroleum heavy residual oil. The resulting cracking oil is then distilled to produce a high boiling point fraction having a boiling point of 300.degree. C. or more. The fraction is then subjected to thermal modification. The pitch is then utilized to produce carbon fibers which have desirable characteristics. The process is advantageous in that it makes possible the use of a wide variety of different types of oils in order to produce a pitch which can be utilized in producing carbon fibers having desirable characteristics.

Abstract: The disclosure relates to a composition suitable for use in mechanical power transmission devices. It has as its principal component a hydrocarbon oil which has from 19 to 30 carbon atoms, inclusive, and three six-membered carbocyclic rings and consists of a mixture of compounds having the following formula: ##STR1## wherein R.sup.1 is a divalent straight or branched chain radical C.sub.y H.sub.2y where y is an integer of 1 through 3; R.sup.2 is a straight chain radical C.sub.z H.sub.2z where z is an integer of 1 through 3; R.sup.3, R.sup.4, and R.sup.

Abstract: A coal-oil mixture comprising pulverized coal dispersed in hydrocarbon oil containing olefinic hydrocarbons having at least 8 carbon atoms in an amount of at least 5% by volume, based on the total volumes of the hydrocarbon oil and the olefin.