Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
  • D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
  • D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
  • D01F9/14—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments
  • D01F9/145—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues
  • D01F9/155—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues from petroleum pitch
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
  • D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
  • D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
  • D01F9/14—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments
  • D01F9/145—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues
  • D01F9/15—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from pitch or distillation residues from coal pitch

Definitions

• the present invention relates to a process for producing a carbon fiber from pitch material such as a coal-originated pitch, a petroleum pitch or a baked polymer pitch. More particularly, it relates to a process for producing such a pitch-type carbon fiber of high quality which is composed of carbon fiber monofilaments bound together without direct adhesion or fusion to one another, and which is easy to handle.
• pitch material such as a coal-originated pitch, a petroleum pitch or a baked polymer pitch. More particularly, it relates to a process for producing such a pitch-type carbon fiber of high quality which is composed of carbon fiber monofilaments bound together without direct adhesion or fusion to one another, and which is easy to handle.
• the present inventors have previously proposed to use a silicone oil as the oiling agent for bundling.
• the present invention provides a process for producing a carbon fiber from pitch material, which comprises melt spinning pitch material in a gaseous atmosphere to form precursory pitch fibers and bundling the precursory pitch fibers, followed by infusible treatment and carbonization and optionally by graphitization, characterized in that an aqueous emulsion of a silicone oil is applied as an oiling agent to the precursory pitch fibers prior to or during the bundling operation.
• the pitch material to be used in the present invention there may be mentioned a coal-originated pitch such as coal tar pitch or liquefied coal; a petroleum pitch such as a distillation residue obtained by the distillation of crude oil under atmospheric or reduced pressure or a heat-treated product thereof, or a heat-treated product of by-product tar obtained by the pyrolysis of naphtha; and a baked polymer pitch obtained by the carbonization of a synthetic or natural resin.
• a coal-originated pitch such as coal tar pitch or liquefied coal
• a petroleum pitch such as a distillation residue obtained by the distillation of crude oil under atmospheric or reduced pressure or a heat-treated product thereof, or a heat-treated product of by-product tar obtained by the pyrolysis of naphtha
• a baked polymer pitch obtained by the carbonization of a synthetic or natural resin.
• the melt spinning of the pitch material is conducted by extruding it into a gaseous atmosphere through spinning nozzles in the same manner as in the case of the dry melt spinning of ordinary synthetic fibers. It is preferred to employ a method wherein the pitch material is melted by an extruder or the like and extruded into a gaseous atmosphere from spinning nozzles directed downwardly, whereupon the extruded fibers are cooled and solidified. It is usual to employ spinning nozzles with discharge outlets having a diameter of from 0.1 to 0.5 mm.
• the temperature of the spinning nozzles is determined depending upon the type of the pitch material to provide a melt viscosity most suitable for spinning, and it is usually selected within a range of from 250 to 350°C. It is effective for the stabilization of spinning to provide temperature-keeping cylinders below the spinning nozzles.
• an aqueous emulsion of a silicone oil is applied as an oiling agent to the precursory pitch fibers obtained by the spinning, prior to or during the bundling operation.
• a silicone oil dimethylpolysiloxane is usually employed.
• modified dimethylpolysiloxane derivatives obtained by introducing various groups to dimethylpolysiloxane there may be mentioned, for example, methylphenylpolysiloxane or hydrodienepolysiloxane.
• silicone oils may be used alone or in combination as a mixture of at least two different kinds.
• the aqueous emulsion of a silicone oil may be prepared by mixing the silicone oil with water by means of a common mixing device such as a high speed mixer, a colloid mill or a homogenizer so that the silicone oil constitutes from 0.1 to 35% by weight in the mixture.
• a common mixing device such as a high speed mixer, a colloid mill or a homogenizer
• an emulsifier may be added.
• an emulsifier there may be employed conventional emulsifiers.
• a nonionic emulsifier such as a sorbitan fatty acid ester e.g.
• sorbitan palmitic acid ester sorbitan stearic acid ester, polyoxyethylene sorbitan fatty acid ester or polyoxyethylene sorbitan caproic acid ester, polyoxyethylene lauric acid ester, acetylated monoglyceride, acetylated glyceryl monostearate or a polyoxyethylene lanolin derivative; an anionic emulsifier such as an alkyl sulfate, sodium laurylsulfate, sodium cetylsulfate, a dialkyl sulfosuccinate or sodium di-2-ethylhexyl sulfosuccinate; or a cationic emulsifier such as alkyl pyridinium chloride. Further, a small amount of fine solid particles may be added to the aqueous emulsion of a silicone oil.
• the amount exceeds 15% by weight, depending upon the concentration of the oiling agent, the evaporation at the time of the infusible treatment will be inadequate, and the agent will remain on the filaments and thus hinders the infusible reaction, and a low molecular weight gas generated from the fibers during the infusible treatment will not sufficiently be dissipated, whereby the strength of the carbon fiber will be reduced.
• the precursory pitch fibers having the aqueous solution of a silicone oil applied thereon and bundled, are subjected to infusible treatment and carbonization treatment in accordance with known methods.
• the infusible treatment may be conducted by heating the tow of fibers at a temperature of from 150 to 360 0 C for from 5 minutes to 10 hours in an oxidizing atmosphere such as oxygen, ozone, air, a nitrogen oxide, halogen or sulfur dioxide.
• the carbonization treatment may be conducted by heating the tow of fibers at a temperature of from 1000 to 2500 0 C for from 0.5 minute to 10 hours in an inert gas atmosphere such as nitrogen or argon.
• a load or tension may be applied to the tow of fibers to some extent during the infusible treatment, the carbonization treatment or the graphitization treatment for the purpose of preventing shrinkage or deformation.
• the infusible treatment it is desirable to preliminarily adjust the deposition of water on the precursory pitch fibers to a level of at most 0.1% by weight either by providing a drier immediately before the infusible treatment furnace, or by drying, at the initial stage of the infusible treatment, the precursory pitch fibers at from 50 to 100°C for 5 minutes to 2 hours.
• Coal tar-originated pitch material (meso-phase pitch having an optical anisotropy of 100%) was melt-spun into a gaseous atmosphere at a spinneret temperature of 330°C. Then, an oiling agent as identified in Table 1 was applied by spraying to the precursory pitch fibers having a diameter of 10 ⁇ m thereby obtained, and the fibers were bundled together. The bundled fiber (i.e. tow) was dried in air at 80 0 C for 30 minutes. Then, it was heated from 150°C to 350°C over a period of 2 hours 40 minutes and held at that temperature for 30 minutes to conduct infusible treatment.
• the fiber was subjected to carbonization treatment by heating it in argon from room temperature to 1,400°C over a period of 2 hours 20 minutes, and then maintaining it at that temperature for one hour, whereby a carbon fiber was obtained.
• Example 1 The operation was conducted in the same manner as in Example 1 except that no oiling agent was used or the amount or the type of the oiling agent was varied. The results are shown in Table 1.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Textile Engineering (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Inorganic Fibers (AREA)

Applications Claiming Priority (2)

Publications (3)

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Family Applications (1)

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Cited By (3)

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Family Cites Families (5)

• 1984
  • 1984-09-11 JP JP59190404A patent/JPH06102852B2/ja not_active Expired - Lifetime
• 1985
  • 1985-09-02 EP EP85111031A patent/EP0175200B1/de not_active Expired - Lifetime
  • 1985-09-02 DE DE8585111031T patent/DE3578440D1/de not_active Expired - Lifetime

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