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: Disclosed herein is a process for producing pitch-based carbon fibers having the specific properties comparable to those of polyacrylonitrile(PAN)-based carbon fibers, wherein an optically isotropic pitch obtained by polymerizing naphthalene at a temperature of not more than 330.degree. C. and heating the thus obtained polymeric material at a temperature of 330.degree. to 440.degree. C. while introducing an inert gas thereinto to remove volatile components therefrom, is subjected to melt-spinning, infusibilization (therosetting) and carbonization and the thus obtained carbonized-fibers are subjected to heat treatment at a temperature of not less that 900.degree. C. to obtain the carbon fibers.

Abstract: Asphaltenes are separated from hydrocarbon oil by bringing the oil into contact with formic acid or a water-soluble organic acid consisting of carbon, hydrogen and oxygen and having at least two functional groups.

Abstract: An improved method for reducing fouling and corrosion of ethylene cracking furnaces petroleum feedstocks, the improvement comprising treating the petroleum feed stock with at least 10 ppm of a combination of a phosphorous antifoulant compound and a filming inhibitor. The antifoulant compound is chosen from the group consisting of phosphite esters, phosphate esters, thiophosphite esters, thiophosphate esters and mixtures thereof, said esters being characterized by the formulas ##STR1## where X equals S or O, and R.sub.1, R.sub.2, and R.sub.3, are each independently selected from the group consisting of hydrogen, water soluble amine, alkyl, aryl, alkaryl, cycloalkyl, alkenyl, and aralkyl group provided that in at least one and not more than two of each R.sub.1, R.sub.2, and R.sub.3 are water soluble amines having partition coefficients greater than 1.0 mixed with a filming amount of at least 2-20 ppm imidazoline filming inhibitor prepared preferably from naphthenic or fatty acids and poly amines.

Abstract: A mesophase pitch suitable for carbon fiber production is produced by heat soaking a heavy aromatic hydrocarbon feedstock at conditions such that a substantial part of the feedstock is converted to mesophase pitch. The mesophase pitch is separated from the heat soaked material by settling at a pressure higher than the pressure of the heat soaking step. In one embodiment, separate mesophase pitches having different properties can be recovered from the heat soaked feedstock.

Abstract: A process for the preparation of an excellent mesophase pitch suitable for use as a spinning pitch for the production of high performance carbon fibers is disclosed. The mesophase pitch can satisfy the four remarkable characteristics at the same time, i.e., a softening point of below 320.degree. C. as determined by Mettler method, a mesophase content of above 90% as examined on a polarized microscope, a quinoline insoluble content of less than 20%, and a xylene soluble content of less than 20%. The mesophase pitch is particularly homogeneous and is easily spinnable. The process can be characterized by a preliminary extraction step, a continuous heat treatment step, and an extraction step. In some cases, the preliminary extraction step can be omitted. Graphite fibers having a tensile strength of about 400 Kg/mm.sup.2 and a modulus of elasticity of above 60 ton/mm.sup.2 can be obtained from the mesophase pitch. Further, even carbon fibers prepared at a carbonization temperature of 1000.degree. C.

Abstract: A process for manufacturing a carbon fiber or graphite fiber includes melt-spinning a carbonaceous pitch, infusibilizing the resulting pitch fiber, carbonizing, and when necessary graphitizing the fiber. A precursor of the carbonaceous pitch is centrifuged in a molten state to separate the precursor pitch simultaneously into a solids slurry layer, an optically isotropic phase, and an optically anisotropic phase, and the latter is utilized as the carbonaceous pitch.

Abstract: An asphalt composition is disclosed having improved adhesion to aggregate comprising asphalt and an adhesion improving amount of an anti-stripping agent comprising the aminoester reaction product of at least one tall oil fatty acid and triethanolamine.

Abstract: A paving composition formed of aggregate and asphalt cement in which the asphalt cement is treated with a combination of a primary catalyst comprising a compound chosen from the group consisting of asphalt cement soluble organic-manganese, organic-cobalt, and organic-copper compounds, or a mixture of two or more thereof, and a secondary catalyst comprising an asphalt cement soluble organic-iron compound.

Abstract: A novel optically anisotropic pitch is provided which is produced by thermal modification of a polymer having a structure of an alkylbenzene and a condensed aromatic compound with two to four fused rings bonded to each other via a methylene group.In preferred embodiments, the optical anisotropy is 80% or more. As the alkylbenzene there may be used xylene, trimethylbenzene or tetramethylbenzene. As the condensed aromatic compound with two to four fused rings, there may be used naphthalene, anthracene, phenanthrene, or naphthacene. The polymer starting material may be obtained by the reaction of a xylene formalin resin, mesitylene formalin resin or alkylbenzene and a condensed aromatic compound with two to four fused rings in the presence of a protonic acid as a catalyst.

Abstract: A process for producing an optically anisotropic pitch for use in the production of high performance carbon fibers, wherein a compound represented by the formula (1) as a raw starting material is mixed with one of heavy oils and subjected to thermal modification: ##STR1## wherein m is an integer of 2 or more; 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, a methyl group or an ethyl group; and R.sub.5 represents a hydrogen atom or a methyl group. The pitch has a softening point which can be set at discretion and excellent molecular orientation.

Abstract: A process for an efficient preparation of a mesophase pitch is disclosed. The process is suitable for the production of high performance carbon fibers, from a coal tar or a petroleum residual oil. More particularly, the present invention relates to a process for the preparation of a homogeneous mesophase pitch which comprises a continuous thermal treatment of a heavy oil or a pitch which does not contain quinoline insoluble fractions, in the presence or absence of an aromatic oil, subsequent distillation of the thermally treated product, recovery of a pitch with extremely low quinoline insoluble contents, hydrogenation of the pitch by continuous thermal treatment in the presence of a hydrogen-donating solvent, distillation and recovery of a hydrogenation pitch, and thermal treatment of the hydrogenated pitch. The mesophase pitch prepared by the process of the present invention is suitable for the production of high performance carbon fibers.

Abstract: An asphalt cement mixture is disclosed. The mixture has improved antistripping properties due to the inclusion therein of a minor amount of an antistripping agent produced by the condensation reaction of an amine, an aldehyde or aldehyde reaction synthon an alkylated phenol. The antistripping agent is preferably present in the asphalt cement in an amount of from about 0.25% to about 1% by weight based on the weight of the asphalt cement. The asphalt cement is combined with an aggregate to form a concrete and paved onto a road surface to provide a paved surface with improved durability.

Abstract: A process for producing pitch useful as a starting material for the manufacture of a carbon material is provided. The pitch is produced by polymerizing a condensed nuclear aromatic compound or a material containing the same. The polymerization is carried out in the presence of a hydrogen fluoride/boron trifluoride catalyst system. The condensed nuclear aromatic compounds which may be used in this process are naphthalene, anthracene, phenanthrene, acenaphthene, acenaphthylene, pyrene and mixtures thereof.

Abstract: Asphalt compositions are improved by incorporating therein the reaction product of (a) a phosphorus-containing compound, (b) an amine or polyamine and (c) a carbonyl-containing compound as an anti-stripping agent. These asphalt compositions are useful as a pavement material by blending with an aggregate.

Abstract: Bituminous compositions are improved by incorporating therein the reaction product of an organic amine with a substituted nitrogen-containing heterocyclic compound as an anti-stripping agent. These compositions are useful as a pavement material by blending with an aggregate.

Abstract: Pyrolysis tars are upgraded by hydrotreatment in the presence of a catalyst having a hydrogenation component and an acidic component. The treated pyrolysis tars are used to produce premium cokes useful in the production of graphite electrodes.

Abstract: A process for producing a pitch useful as a raw material for carbon fibers, which comprises(1) heat-treating at least one starting material selected from the group consisting of a heavy oil obtained by fluid catalytic cracking of a petroleum, a distillate or a residual oil obtained by distilling the heavy oil, and a pitch obtained by heat-treating any of the foregoing materials at a temperature of 350.degree. to 550.degree. C.,(2) separating and removing insoluble substances from the reaction mixture obtained in step (1) to obtain a first treated mixture,(3) heating the first treated mixture obtained in step (2) at a temperature of 250.degree. to 400.degree. C. and removing light fractions which distill at said temperature to obtain a second treated mixture, and(4) treating the second treated mixture obtained in step (3) at a temperature of 430.degree. to 550.degree. C.

Abstract: Crushed sulfur is melted by and is mixed with hot liquid asphalt at a manufacturing plant, after which the mixture is formed into sulfur-asphalt pellets. The sulfur added to the asphalt prevents a mass of the pellets from flowing and conglomerating at ambient temperatures. The pellets thus may be shipped in bulk form and without special temperature control from the manufacturing plant site to a remote site where the pellets are mixed with heated aggregate and are melted to form a sulfur-extended bituminous concrete paving composition for application to a roadway. By mixing a fine mineral filler such as calcium hydroxide with the crushed sulfur and the hot liquid asphalt at the manufacturing plant, temperature-stable pellets may be produced while using a lower ratio of sulfur to asphalt in the mixture. If desired, aggregate also may be added to the mixture at the manufacturing plant to form briquettes and avoid the need of mixing the pellets with aggregate at the paving site.

Abstract: A nitro-substituted pitch demonstrates softening point temperatures in the range of 75.degree.-250.degree. C. and a coking value of at least about 40%. Such pitch is produced by reacting a tar with a nitrating agent at a temperature below 150.degree. C. and above about 0.degree. C.

Abstract: A method of producing high quality, homogenous asphalt comprising the steps of mixing and heating a hydrocarbon feedstock not normally suited for asphalt production with elemental sulfur and agitating the resulting mixture. A halide catalyst may be added to the mixture to promote the reaction of the hydrocarbon feedstock with the sulfur. If desired, the agitated mixture may be air blown in any conventional manner to increase its hardness.

Abstract: A simpler and new process for the polycondensation of a sulfonated coal tar fraction comprising: sulfonating a coal tar fraction having a distillation range of 200.degree. to 240.degree. at normal pressure, with an excess of 20-30% mole of sulfuric acid, as opposed to 105% in the prior art, for 4-8 hours at a temperature of 160.degree. C..+-.10.degree. C. under reflux. The product is diluted with water to render it fluid at about 80.degree. C. and molar ratio of formaldehyde per mole of the sulfonated coal tar fraction is then added gradually at a temperature of about 85.degree. C..+-.5.degree. C., then gradually heated for about 1 to 4 hours at 100.degree. to 106.degree. C., and then further raised to 106.degree. C.-120.degree. C. for 2 to 4 hours. The product is then cooled and neutralized. With this process, new polycondensates with improved properties are produced. The polycondensation including neutralization is completed within 16 hours from the time the formaldehyde is added.

Abstract: Sulfonated asphalt is produced by heating an asphaltic material, preferably having a softening point between about 315.degree. F. and 350.degree. F.

Abstract: Pyrolysis tars are upgraded by hydrotreatment thereof in the presence of an acidic catalyst. The treated pyrolysis tars are used to produce premium cokes useful in the production of graphite electrodes.

Abstract: An asphaltic composition comprising an asphalt admixed with an aggregate and at the interface between said asphalt and said aggregate the reaction product of an amine antistrip and an acid salt in an amount sufficient to bind said asphalt to said aggregate; said acidic salt being a divalent or trivalent metal salt of an inorganic acid.

Abstract: 1. A process for reducing the sulfur content of petroleum asphaltenes containing sulfur comprising:(1) forming a mixture of petroleum asphaltenes containing sulfur and a liquid selected from the group consisting of water, methanol, carbon dioxide and mixtures thereof;(2) raising the temperature and pressure of the mixture to a temperature and pressure above the critical temperature and pressure of the liquid to convert the liquid to a supercritical fluid;(3) maintaining the mixture above the critical temperature and pressure of the liquid for a time sufficient to effect sulfur reduction;(4) reducing the pressure to a second lower pressure; and(5) recovering petroleum asphaltenes reduced in sulfur.

Abstract: A new and novel process is described for preparing an aromatic pitch having a high liquid crystal fraction and being suitable for carbon artifact manufacture, such as for the manufacture of pitch carbon fiber.

Abstract: Disclosed is a one-step method of producing an industrial asphalt from a bituminous material which comprises mixing together without air-blowing:(a) a feed material comprising a bituminous material having a viscosity of at least 50 centistokes at 350 degrees Fahrenheit and wherein the feed petroleum residuum forms a single phase when mixed with 5 percent of paratoluene sulfonic acid; and(b) from about 0.1 to 20.0 percent by weight of an organic sulfonic acid, said mixing being done at a temperature in the range of 351 to 600 degrees Fahrenheit, whereby the softening point of the feed is substantially increased and the penetration is significantly decreased.

Abstract: Until now, it has not yet been succeeded to prepare high performance carbon fibers having satisfactory strength from heavy oils of coal or petroleum origin. We now succeeded to prepare an excellent intermediate pitch which allows the preparation of high performance carbon fibers having tensile strength of higher than 300 Kg/mm.sup.2 and Young's modulus of 50 ton/mm.sup.2.The intermediate pitch can be obtained by heating a heavy oil of coal or petroleum origin in a tubular heater under a specific conditions, and then flash distilling the heater effluent in a flash distillation column under a specific condition so as to remove lighter fractions and recovering heavy fraction from the column bottom as the intermediate pitch. The process for the preparation of the intermediate pitch is simple and economical and allows continuous production without fluctuation of quality of the intermediate pitch. The intermediate pitch is also suitable for the production of higher density carbon products.

Abstract: Pitch is converted to mesophase pitch in the presence of catalytically effective amounts of oxides, diketones, carboxylates and carbonyls of metals selected from vanadium, chromium, molybdenum, iron, nickel and cobalt. The crystalloidal or mesophase pitch obtained can be used for the production of carbon fibers and other carbon and graphite products and articles of manufacture of unusually high quality.

Abstract: An asphalt-based composition comprising an air-blown blend of hard asphalt flux and the residue obtained by vacuum distilling the product obtained by the hydrogenation of asphalt flux, the composition meeting coating grade asphalt specifications.

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: In a process for producing an optically anisotropic carbonaceous pitch having a low softening point for the production of carbon material starting oil to be used is a tar-like substance which is a mixture of compounds not substantially containing chloroform insolubles but containing components having a boiling point of 540.degree. C. or more as principal components and consisting principally of carbon and hydrogen. The tar-like substance has a content of n-heptane insolubles of up to 1 wt % and contains an aromatic oil fraction and a resin fraction as the principal components of n-heptane soluble components. The aromatic carbon fraction, fa, is at least 0.7, the number-average molecular weight is up to 1,000 and the maximum molecular weight is up to 2,000 for each of the aromatic oil and resin fractions.

Abstract: Bulk mesophase can be economically produced without coking trouble from a heavy oil in an apparatus comprising: a heat-treatment vessel for heat treating the oil thereby to form pitch containing mesophase microspheres; a cyclone-type separator installed directly below the vessel and operating to cause the mesophase microspheres within the pitch introduced into the separator to coalesce thereby to separate the mesophase microspheres from the matrix pitch; and ascent and descent pipes communicatively connecting the interiors of the vessel and the separator, the ascent pipe returning matrix pitch after removal of the mesophase microspheres into the vessel together with newly supplied oil, which drives the matrix pitch by jet-pump action, the descent pipe introducing the pitch with mesophase microsphere into the top part of the separator in a horizontal tangential direction to produce a cyclone separation action therein.

Abstract: Pitch free from quinoline insoluble components is prepared by heat-treating coal tar or coal tar pitch in the absence or in the presence of carbonaceous particles and centrifuging at a high temperature the reaction product resulting from the heat treatment or a mixture of the reaction product from the heat treatment and coal tar-type light or middle oil.

Abstract: Formaldehyde adducts of amines, polyamines and amides conforming to the general formula ##STR1## are employed in asphalt compositions in order to improve the overall adhesion between the asphalt and aggregate or glass fiber or glass fiber mesh and to thereby increase the tensile strength of the asphalt composition.

Abstract: Disclosed is a one-step method of producing an industrial asphalt from a bituminous material which comprises mixing together without air-blowing:(a) a feed material comprising a bituminous material having a viscosity of at least 50 centistokes at 350 degrees Fahrenheit and wherein the feed petroleum residuum forms a single phase when mixed with 5 percent ferric chloride; and(b) from about 0.1 to 20.0 percent by weight of ferric chloride, said mixing being done at a temperature in the range of 351 to 600 degrees Fahrenheit, whereby the softening point of the feed is substantially increased and the penetration is significantly decreased.

Abstract: A method of producing carbon materials having high density and strength, which method includes starting from a calcined product or its classified product having particular properties obtained by calcining a residue after heat treatment, solvent extraction and filtration of coal tar pitch at 250.degree.-500.degree. C. in an inert gas atmosphere, and then molding, firing and graphitizing it.

Abstract: A mesophase pitch suitable for carbon products, particularly for carbon fibers, which has a mesophase content of at least 40%, preferably at least 60%, and a larger mesophase domain, is produced by adding at least one part by weight of at least one of an alcohol and a phenol to 100 parts by weight of heavy bitumens, subjecting the resulting mixture to pretreatment by heating at least at 250.degree. C., and then subjecting the pretreated mixture to heat treatment until mesophases are formed.

Abstract: Disclosed is a one-step method of producing an industrial asphalt from a bituminous material which comprises mixing together without air-blowing:(a) a feed material comprising a bituminous material having a viscosity of at least 50 centistokes at 350 degrees Fahrenheit and wherein the feed forms a single phase when mixed with 5 weight percent zinc chloride; and(b) from about 0.1 to 20.0 percent by weight of zinc chloride, said mixing being done at a temperature in the range of 351 to 600 degrees Fahrenheit, whereby the softening point of the feed is substantially increased and the penetration is significantly decreased.

Abstract: Disclosed is a one-step method of producing an industrial asphalt from a bituminous material which comprises mixing together without air-blowing:(a) a feed material comprising a bituminous material having a viscosity of at least 50 centistokes at 350 degrees Fahrenheit and wherein the feed material forms a single phase when mixed with 5 weight percent maleic anhydride; and(b) from about 0.1 to 20.0 percent by weight of maleic anhydride, said mixing being done at a temperature in the range of 351 to 600 degrees Fahrenheit, whereby the softening point of the feed is substantially increased and the penetration is significantly decreased.

Abstract: A process for air-blowing asphalt in the presence of hydrohalic acids, particularly hydrobromic acid, and an asphalt composition comprising a major amount of asphalt and a minor but effective amount of hydrohalic acid is disclosed.

Abstract: Disclosed is a one-step method of producing an industrial asphalt from a bituminous material which comprises mixing together without air-blowing:(a) a feed material comprising a bituminous material having a viscosity of at least 50 centistokes at 350 degrees Fahrenheit and wherein the feed petroleum residuum forms a single phase when mixed with 5 weight percent hydrobromic acid; and(b) from about 0.1 to 20.0 percent by weight hydrobromic acid, said mixing being done at a temperature in the range of 351 to 600 degrees Fahrenheit, whereby the softening point of the feed is substantially increased and the penetration is significantly decreased.

Abstract: The invention provides a novel pitch material useful as a base material of carbon fibers having excellent mechanical properties and characterized by a unique combination of several property parameters including the content of the optically anisotropic phase of at least 80%, a content of the pyridine-insoluble matter in the range from 30 to 70% by weight, a number average molecular weight in the range from 1000 to 1400 and a softening point in the range from 330.degree. to 380.degree. C. Such a pitch material is obtained from a starting pitch of a petroleum-based residual oil freed from light oily matter through a two-step heat treatment, of which the first step is performed at 400.degree. to 460.degree. C. under a pressure of 5 to 50 mmHg and the second step is performed at 450.degree. to 550.degree. C. for 0.2 to 30 minutes under a pressure of 0.1 to 5 mmHg. The advantages obtained by use of a film evaporator in the above mentioned heat treatment are described.

Abstract: The invention provides a method for the preparation of a pitch spinnable into pitch filaments as a precursor of carbon fibers starting from a pitch material such as coal tar and coal tar pitch. Different from the conventional procedure involving hydrogenation of the starting pitch, the starting pitch in the inventive method is first heated together with an aromatic oil, preferably, in the presence of a cracking catalyst such as silica-alumina and zeolite at 350.degree. to 500.degree. C. for 10 to 60 minutes under no pressurization with hydrogen and, after removal of insoluble materials, then heated at a temperature of 430.degree. to 600.degree. C. The thus obtained pitch for spinning has good spinnability and the carbon fibers prepared from the pitch have a unique microscopic structure and excellent physical properties exceeding by far the conventional pitch-based carbon fibers and approximating the HP-grade carbon fibers prepared from polyacrylonitrile fibers.

Abstract: The present invention relates to specialty pitches having low Q.I. content, lower viscosity, lower average Q.I. particle size, lower ash content, higher toluene insoluble and beta-resin content. They may be prepared by extracting the coal-tar material with a solvent, where the solvent contains at least one n-methyl-2-pyrrolidone and the wash oil fraction of coal-tar distillate. The solvent-dissolved fraction of the coal-tar material is then distilled to obtain the specialty pitch material.

Abstract: In a process for producing an optically anisotropic carbonaceous pitch having a low softening point for the production of carbon material a starting oil to be used is a tar-like substance which is a mixture of compounds not substantially containing chloroform insolubles but containing components having a boiling point of 540.degree. C. or more as principal components and consisting principally of carbon and hydrogen. The tar-like substance has a content of n-heptane insolubles of up to 1 wt % and contains an aromatic oil fraction and a resin fraction as the principal components of n-heptane soluble components. The aromatic carbon fraction, fa, is at least 0.7, the number-average molecular weight is up to 1,000 and the maximum molecular weight is up to 2,000 for each of the aromatic oil and resin fractions.

Abstract: Pitch is converted to mesophase pitch in the presence of catalytically effective amounts of oxides, diketones, carboxylates and carbonyls of metals selected from vanadium, chromium, molybdenum, iron, nickel and cobalt. The crystalloidal or mesophase pitch obtained can be used for the production of carbon fibers and other carbon and graphite products and articles of manufacture of unusually high quality.

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 substantially uniform mesophase pitch is prepared by treating a mesophase forming pitch material at elevated temperatures above about 380.degree. C. to produce a mixture of mesophase and non-mesophase pitch containing about 20% to about 80% mesophase. The mixture is then maintained at a temperature below about 400.degree. C. for a time sufficient to allow the mesophase to coalesce and settle as a lower separable layer. A mesophase pitch so produced may contain from 90 to 100% mesophase with a softening point of less than 320.degree. C.