US3904716A - Carbon fibre production - Google Patents

Carbon fibre production Download PDF

Info

Publication number
US3904716A
US3904716A US458035A US45803574A US3904716A US 3904716 A US3904716 A US 3904716A US 458035 A US458035 A US 458035A US 45803574 A US45803574 A US 45803574A US 3904716 A US3904716 A US 3904716A
Authority
US
United States
Prior art keywords
particles
fibres
microns
spinning
heat treatment
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US458035A
Other languages
English (en)
Inventor
Roger Moreton
William Watt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BTG International Ltd
Original Assignee
Nat Res Dev
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nat Res Dev filed Critical Nat Res Dev
Application granted granted Critical
Publication of US3904716A publication Critical patent/US3904716A/en
Assigned to BRITISH TECHNOLOGY GROUP LIMITED reassignment BRITISH TECHNOLOGY GROUP LIMITED ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: NATIONAL RESEARCH DEVELOPMENT CORPORATION
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • D01F9/20—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products
    • D01F9/21—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • D01F9/22—Carbon filaments; Apparatus specially adapted for the manufacture thereof by decomposition of organic filaments from polyaddition, polycondensation or polymerisation products from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyacrylonitriles
    • 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
    • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
    • D01F6/28—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • D01F6/38—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds comprising unsaturated nitriles as the major constituent
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
    • Y10S264/19—Inorganic fiber

Definitions

  • ABSTRACT A process for the preparation of polyacrylonitrile precursor fibres and their subsequent conversion to carbon fibres, in which at least the fibre spinning process and oxygen permeation process are carried out under conditions in which particles, and so far as the spinning solution is concerned air bubbles, are excluded from the liquids employed in the spinning process and from the gases in which such process and the oxygen permeation process take place is described.
  • Carbon fibres produced by the above process have an ultimate tensile strength which increases as the final heat treatment temperature is increased, over the whole range of final heat treatment temperatures used up to 3000C.
  • Carbon fibres produced by this process and by modifications of this process as hereinbefore described are disclosed in,for example UK Specifications 1,168,619, 1,165,252, 1,166,251, show a Youngs Modulus which increases as the final heat treatment temperature is in creased but the ultimate tensile strength shows a maximum, generally in the region of 1,500C. It is therefore impossible to obtain a carbon fibre by these processes having simultaneously maximum values of both Youngs Modulus and ultimate tensile strength.
  • a process for the preparation of polyacrylonitrile precursor fibres and their subsequent conversion to carbon fibres which includes the steps of spinning the polyacrylonitrile precursor fibres from solution, heating the precursor fibres at a temperature in the range 200300C in an oxidising atmosphere for a time sufficient to permit complete permeation of oxygen while the natural shrinkage of the polyacrylonitrile precursor fibre is at least restrained, followed by carbonisation and further heat treatment at temperature of up to 3,000C includes the improvement wherein the spinning process and oxygen permeation process are carried out under conditions in which particles, and also in the case of the spinning solution, gas bubbles, are excluded from the liquids employed in the spinning process and from the gases in which such process and the oxygen permeation process take place, whereby carbon fibres are produced having an ultimate tensile strength which increases as the final heat treatment temperature is increased over the whole range of final heat treatment temperatures.
  • the carbonisation and also the further heat treatment are also out under conditions in which particles are excluded.
  • the particles are excluded by filtering the said liquids and gases'through filters capable of removing any particles having a size greater than 3 microns.
  • the filtering applied to the liquids is such that the size of particles excluded is the smallest commensurate with ease of filtration.
  • a filter capable of excluding any particles having a size greater than 1.5 microns it had been found convenient to use a filter capable of excluding any particles having a size greater than 1.5 microns, whereas less viscous coagulation bath liquids and wash liquids can be conveniently filtered through a filter, capable of exeluding particles having a size greater than 0.25 microns.
  • the air or gas supplied to air or gas spaces around the apparatus is advantageously passed through laminar air flow filters capable of meeting Class clean room conditions as set forth in U.S. Federal Standard 209A, that is not more than 100 particles per cubic foot of a size greater than 0.5 microns and none greater than 5 microns, and preferably such gas or air does not contain more than 10 particles per cubic foot of a size greater than 0.5 microns.
  • a stage of the process eg the oxygen permeation step, carbonisation or further heat treatment is carried out in a stream of gas, that gas is passed through a 0.05 micron filter before contact with the fibre under heat treatment.
  • carbonisation means heating in vacuo, or in an inert of reducing atmosphere with respect to carbon, at a temperature at which volatile materials are driven off from the polyacrylonitrile fibres leaving a carbon residue which may contain a minon proportion of other elements, eg up to 5% by weight of nitrogen.
  • carbonisation takes place at temperatures broadly within the range 800 to 1200C although temperatures of up to 1500C may be included.
  • Further heat treatment may be an extension of the carbonisation process in which the temperature is raised to the described final temperature or it may be a separate step or steps.
  • polyacrylonitrile as used in the present specification includes within its scope copolymers or terpolymers or acrylonitrile with not more than 15% and preferably less than 10% by weight of other monomers, for example, methyl methacrylate, methyl acrylate or vinyl acetate, either alone or to which have been added polymers compatible with them.
  • carbon fibres having a length of less than 5 cm, produced in accordance with the present invention do not show a significant change in tensile strength as the gauge length of the test specimen is reduced.
  • the spinning apparatus was a laboratory spinning apparatus.
  • the apparatus included a reservoir for the spinning solution pressurised by argon and a stainless steel spinneret. After extrusion the fibre passed sequentially through a coagulation bath, 1.20 metres in length, a water wash bath, a steam stretch tube, 0.60 metres long, a filrther water wash bath, a traversing device, and was finally taken up on a fused silica collecting frame. All the baths were contained in polyethylene coated stainless steel tanks.
  • a bank of laminar air flow filters directed a flow of clear air towards the apparatus.
  • the flow was directed in a direction parallel to the longitudinal axis of the spinning apparatus with the mechanism of the spinning apparatus and the operators downstream of the apparatus so that any contamination generated by them was carried away from the apparatus.
  • the laminar air flow filters were nominally capable of providing a clean zone covering the apparatus up to Class 100 conditions as set forth in US Federal Standard 209A; that is less than 100 particles of size greater than 0.5 microns per cubic foot and none of 5 microns and a check of the apparatus showed that air delivered to the clean area did not contain more than particles of a size greater than 0.5 microns per cubic foot.
  • the material used in this work was polyacrylonitrile which included 6% by weight of methyl acrylate as comonomer and had a number average molecular weight of 52500.
  • the spinning solution was prepared by dissolving 14 weight of the polyacrylonitrile/methyl acrylate copolymer in a 50 weight aqueous sodium thiocyanate solvent at a temperature of 9095C.
  • the viscous co polymer solution was stirred for about an hour and while still hot was passed through a 1.5 micron filter.
  • the solution was then de-aerated by warming to a temperature of about 60C, and centrifuging in 3 inch tubes, in an 8 inch diameter centrifuge at 4000 evolutions per minute.
  • the coagulant bath contents, a 10% by weight aqueous sodium thiocyanate, solution, and the distilled water used in the wash baths and in the steam generators were filtered through 0.25 micron filters using a peristaltic pump to provide the driving force.
  • the spinning solution obtained as described above, at room temperature was spun through a five hole spinneret having 75 micron holes in a 10% by weight aqueous sodium thiocyanate coagulation bath at at extru sion rate of 0.30 metres/minute and the speed at the first roller was 0.60 meter/minute.
  • the temperature of the first wash bath was 50C, the steam stretch ratio was 14 and the final wash bath temperature was 30C.
  • the oxidised fibre while still on the fused silica collection frame was placed in a fused silica tube with a tightly fitting cap while in the clean zone to prevent contamination.
  • the tube was then transferred to a furnace and the oxidised fibre heated to 1000C for a period of /2 hour to carbonise the fibres. During the heating a stream of filtered nitrogen was passed over the fibres.
  • sample was split in two and each sample placed in a close fitting carbon tube.
  • One sample was heat treated at 1400C in a vacuum furnace for /2 hour and the other at 2500C in a carbon tube furnace for /2 hour in a steam filtered argon.
  • the carbonising and heat treatment furnaces were not in the clean zone but all transfers were carried out in the clean zone to prevent, or at least minimise, surface contamination during transfer.
  • the streams of nitrogen and argon used were filtered by passing them through 0.05 micron filter Control samples, using the same filtered spinning solution were spun on similar apparatus to the same parameters, but not in the clean zone and were then carbonised and further heat treated in exactly the same way as described above.
  • line 1 represents carbon fibres produced by the process of the present invention
  • line 2 represents carbon fibres produced by an identical process except that the fibres, although not deliberately contaminated, where not spun in clean conditions.
  • the dotted lines represent the 95% confidence limits of the quoted results.
  • Line 2 clearly shows a maximum in ultimate tensile strength, which is normally found
  • line 1 shows that the carbon fibre produced in accordance with the present invention has an ultimate tensile strength which increases as the final heat treatment temperature increases.
  • a process for the preparation of polyacrylonitrile precursor fibres and their subsequent conversion to carbon fibres which includes the steps of spinning the polyacrylonitrile precursor fibres from solution, heating the precursor fibres at a temperature in the range 200300C in an oxidising atmosphere for a time sufficient to permit complete permeation of oxygen while the natural shrinkage of the fibre is at least restrained, followed by carbonisation and further heat treatment at temperatures of up to 3000C which includes the improvement wherein the spinning process and oxygen permeation process are carried out under conditions in which particles, and in the case of the spinning solution, gas bubbles, are excluded from the liquids employed in the spinning process and from the gases in which such process and the oxygen permeation process take place, whereby carbon fibres are produced having an ultimate tensile strength which increases over the whole range of final heat treatment temperatures.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Inorganic Fibers (AREA)
  • Artificial Filaments (AREA)
US458035A 1973-04-06 1974-04-04 Carbon fibre production Expired - Lifetime US3904716A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1654673A GB1455724A (en) 1973-04-06 1973-04-06 Carbon fibre production

Publications (1)

Publication Number Publication Date
US3904716A true US3904716A (en) 1975-09-09

Family

ID=10079273

Family Applications (1)

Application Number Title Priority Date Filing Date
US458035A Expired - Lifetime US3904716A (en) 1973-04-06 1974-04-04 Carbon fibre production

Country Status (6)

Country Link
US (1) US3904716A (enrdf_load_stackoverflow)
JP (1) JPS5052323A (enrdf_load_stackoverflow)
CA (1) CA1050222A (enrdf_load_stackoverflow)
DE (1) DE2416674C2 (enrdf_load_stackoverflow)
FR (1) FR2224405B1 (enrdf_load_stackoverflow)
GB (1) GB1455724A (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4925604A (en) * 1984-10-16 1990-05-15 Nikkiso Co., Ltd. Process for preparing a carbon fiber of high strength

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58214526A (ja) * 1982-06-09 1983-12-13 Toray Ind Inc 高強伸度炭素繊維束
JPS58220821A (ja) * 1982-06-09 1983-12-22 Toray Ind Inc 高強伸度アクリル系炭素繊維束およびその製造法
JPS59137513A (ja) * 1983-01-27 1984-08-07 Toray Ind Inc 高品質，高性能炭素繊維の製造法
CN101260172B (zh) 2007-03-07 2010-05-19 中国科学院化学研究所 超高分子量聚丙烯腈基碳纤维纺丝原液的制备方法
WO2016114385A1 (ja) * 2015-01-16 2016-07-21 三菱レイヨン株式会社 アクリル繊維束の製造方法及び加圧スチーム延伸装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3595946A (en) * 1968-06-04 1971-07-27 Great Lakes Carbon Corp Process for the production of carbon filaments from coal tar pitch

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4925604A (en) * 1984-10-16 1990-05-15 Nikkiso Co., Ltd. Process for preparing a carbon fiber of high strength

Also Published As

Publication number Publication date
FR2224405A1 (enrdf_load_stackoverflow) 1974-10-31
JPS5052323A (enrdf_load_stackoverflow) 1975-05-09
FR2224405B1 (enrdf_load_stackoverflow) 1979-07-06
GB1455724A (en) 1976-11-17
DE2416674A1 (de) 1974-11-07
DE2416674C2 (de) 1984-05-24
CA1050222A (en) 1979-03-13

Similar Documents

Publication Publication Date Title
US3595946A (en) Process for the production of carbon filaments from coal tar pitch
US3997638A (en) Production of metal ion containing carbon fibers useful in electron shielding applications
US3716607A (en) Heat treatment of molten carbonaceous material prior to its conversion to carbon fibers and other shapes
DK143610B (da) Fremgangsmaade til fremstilling af eventuelt carboniserede begfibre
US3904716A (en) Carbon fibre production
CN105200566B (zh) 一种采用原丝拉伸技术制备高强高模碳纤维的方法
US3718493A (en) Process for the production of carbon filaments from coal tar pitch
CA1317422C (en) Formation of melt-spun acrylic fibers possessing a highly uniform internal structure which are particularly suited for thermal conversion to quality carbon fibers
Moreton et al. The spinning of polyacrylonitrile fibres in clean room conditions for the production of carbon fibres
US3841079A (en) Carbon filaments capable of substantial crack diversion during fracture
US3925524A (en) Process for the production of carbon filaments
US3720759A (en) Process for the production of carbon and graphite fibers
CA1055664A (en) Rapid thermosetting of carbonaceous fibers produced from mesophase pitch
JPS602352B2 (ja) プリメソフエ−ス炭素質の製造方法
EP0201213B1 (en) Stabilization of pitch fiber
US3846833A (en) Acrylic filaments which are particularly suited for thermal conversion to carbon filaments
JPS60155714A (ja) ピツチ系炭素繊維の製造方法
USRE27794E (en) Heat treatment of molten carbonaceous material prior to its conversion to carbon fibers and other shapes
JP2849156B2 (ja) 中空炭素繊維の製造方法
CN118814316A (zh) 一种聚丙烯腈基碳纤维、原液及其制备方法
JP3613304B2 (ja) 活性炭素繊維の製造方法
JP2018122293A (ja) ガス分離用炭素膜の製造方法および不融化繊維
JPH0329885B2 (enrdf_load_stackoverflow)
JPH0681221A (ja) 炭素繊維の製造方法
JPH01314734A (ja) ピッチ系炭素繊維の製造法

Legal Events

Date Code Title Description
AS Assignment

Owner name: BRITISH TECHNOLOGY GROUP LIMITED, ENGLAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:NATIONAL RESEARCH DEVELOPMENT CORPORATION;REEL/FRAME:006243/0136

Effective date: 19920709