摘要:
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.
摘要:
A method of manufacturing a semiconductor device having a process for cleaning a semiconductor substrate after the semiconductor substrate is etched for patterning includes a first process of preparing the semiconductor substrate having a first temperature, a second process of setting the semiconductor substrate at a second temperature, a third process of etching the semiconductor substrate having the second temperature by etching liquid having a third temperature, a fourth process of cleaning the semiconductor substrate to which the etching liquid is adhered, by ultrapure water having a fourth temperature, wherein the second temperature is set at the range between the first and the third temperatures.
摘要:
A process for producing optically anisotropic pitch containing 80% or more of an anisotropic phase. A starting material is pyrolytically polycondensed. Afterward, the material is maintained at a temperature of between 350.degree. and 400.degree. C. to precipitate a portion of the material rich in the anisotropic phase having a high specific gravity. This portion is separated and further heat treated.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
It is an object to provide a product sales promotion method that is extremely advantageous for acquiring a new product purchaser. This object is achieved by the product sales promotion method in which a storage means is caused to store a point in time when a purchaser fulfilled an entry requirement and an entry term to which each purchaser belongs is determined, each purchaser is assigned a serial number larger than a serial number assigned to an existing member belonging to an immediately preceding entry term, every time bonus granting time arrives, a member who maintains a bonus granting requirement is arranged such that the higher the serial number, the higher position the member is positioned at, and a value obtained by multiplying the number of subordinate persons viewed from each member by a unit bonus amount is calculated, and a bonus is granted to each member.
摘要:
A method of manufacturing a semiconductor device having a process for cleaning a semiconductor substrate after the semiconductor substrate is etched for patterning includes a first process of preparing the semiconductor substrate having a first temperature, a second process of setting the semiconductor substrate at a second temperature, a third process of etching the semiconductor substrate having the second temperature by etching liquid having a third temperature, a fourth process of cleaning the semiconductor substrate to which the etching liquid is adhered, by ultrapure water having a fourth temperature, wherein the second temperature is set at the range between the first and the third temperatures.
摘要:
A carbon fiber-reinforced carbon composite material is disclosed which includes a matrix of carbon and unidirectionally oriented carbon fibers dispersed in the matrix, wherein the content of the carbon fibers is at least 50% based on the volume of the composite material, wherein the volume of pores having a pore diameter of 10 .mu.m or more is not greater than 5% of the total pore volume of the composite material, and wherein at least 90% of the total pore volume is the volume of open pores. The composite material is obtained by impregnating carbon fibers with a dispersion having a viscosity of 5-50 cP at 25.degree. C. and containing carbonaceous powder with an average particle diameter of smaller than 0.5 .mu.m in an organic solvent solution of a thermosetting resin. After unidirectionally aligning the carbon fibers, the impregnated fibers are molded and cured and then calcined.
摘要:
A composition for an optically anisotropic carbonaceous pitch suitable for the production of a carbon material having a high tensile strength and a high modulus of elasticity. The composition comprises about 2 to 20 percent by weight of a first, n-heptane-soluble component, about 15 to 45 percent by weight of an n-heptane-insoluble and benzene-soluble, second component and the balance of the composition including benzene-insoluble components. The composition has a volume ratio of an optically anisotropic phase of at least about 90% and a softening point of up to about 320.degree. C.