DE3916630A1 - Removing organic components from pressed oxide ceramic material - by heating in nitrogen-oxygen atmos. contg. low amt. of oxygen to prevent temp. differential between inner and outer areas of body - Google Patents

Removing organic components from pressed oxide ceramic material - by heating in nitrogen-oxygen atmos. contg. low amt. of oxygen to prevent temp. differential between inner and outer areas of body

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Publication number
DE3916630A1
DE3916630A1 DE3916630A DE3916630A DE3916630A1 DE 3916630 A1 DE3916630 A1 DE 3916630A1 DE 3916630 A DE3916630 A DE 3916630A DE 3916630 A DE3916630 A DE 3916630A DE 3916630 A1 DE3916630 A1 DE 3916630A1
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DE
Germany
Prior art keywords
oxygen
organic components
ceramic material
oxide ceramic
contg
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.)
Withdrawn
Application number
DE3916630A
Other languages
German (de)
Inventor
August Dr Beer
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.)
Siemens AG
Original Assignee
Siemens AG
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 Siemens AG filed Critical Siemens AG
Priority to DE3916630A priority Critical patent/DE3916630A1/en
Publication of DE3916630A1 publication Critical patent/DE3916630A1/en
Withdrawn legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/632—Organic additives
    • C04B35/634—Polymers
    • C04B35/63404—Polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • C04B35/63416—Polyvinylalcohols [PVA]; Polyvinylacetates
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/632—Organic additives
    • C04B35/634—Polymers
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/638—Removal thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/64—Burning or sintering processes
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
    • C04B38/06—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Magnetic Ceramics (AREA)

Abstract

Pressed bodies made of finely ground oxide ceramic material are decarburised to remove the organic components such as binders, pressing agents, lubricants and softeners by burning out these components in a N2 -O2- containing atmosphere having a max. 20vol.% O2. USE/ADVANTAGE - In the production of ferrite-, hot conductor-, cold conductor and varistor-components. The decarburising process does not lead to a temperature variation between the inside and outside areas of the pressed body which could lead to cracking.

Description

Die Erfindung betrifft ein Verfahren zur Entbinderung bzw. Ent­ kohlung von Preßkörpern, bestehend aus feingemahlenen oxidkera­ mischen Werkstoffen, denen preßtechnisch bedingt organische Be­ standteile, nämlich Bindemittel, z.B. Polyviol, Preßhilfsmittel, insbesondere Gleitmittel und Weichmacher zugesetzt sind, die in einem der Sinterung ggf. getrennt vorgeschalteten Prozeß in O2-haltiger Atmosphäre ausgebrannt werden.The invention relates to a process for debinding or decarburization of compacts, consisting of finely ground oxide ceramics mixing materials to which, due to the pressing technology, organic constituents, namely binders, for example polyviol, pressing aids, in particular lubricants and plasticizers, are added, which may or may not be sintered. separately upstream process are burned out in an O 2 -containing atmosphere.

Beim Verpressen von oxidkeramischen Werkstoffen, insbesondere Werkstoffen für die Fertigung von Ferrit-, Heißleiter-, Kalt­ leiter- und Varistor-Bauelementen werden dem feingemahlenen Pul­ vergemisch in Form organischer Bestandteile die bereits erwähn­ ten Gleitmittel, Weichmacher und Bindemittel, z.B. Polyviole zugesetzt, welch letztes ein langkettier Polyalkohol ist, der im Temperaturbereich 200 bis 350°C unter Luftatmosphäre zu Wasser, Kohlendioxid, Kohlenmonoxid, Essigsäure und Formaldehyd ver­ brennt.When pressing oxide ceramic materials, in particular Materials for the production of ferrite, thermistor, cold conductor and varistor components are the finely ground Pul blended in the form of organic components that already mentioned lubricants, plasticizers and binders, e.g. Polyvioles added, the last one is a long-chain polyalcohol, which in the Temperature range 200 to 350 ° C under air atmosphere to water, Carbon dioxide, carbon monoxide, acetic acid and formaldehyde ver burns.

Die exotherme Reaktion führt dabei häufig zu einem Temperatur­ ungleichgewicht zwischen dem Innen- und Außenbereich des Preß­ körpers, was wiederum infolge unterschiedlicher Ausdehnung zur Rißbildung und damit zum Ausschuß von hochwertigen Bauelementen führen kann. Wesentliche Ursache hierfür ist, daß die im Innen­ bereich des Preßkörpers entwickelte Wärme infolge Isolation im Außenbereich nur ungenügend nach außen abgeführt werden kann und so die bereits angedeuteten Temperaturüberhöhungen im Preß­ körperinneren verursacht.The exothermic reaction often leads to a temperature imbalance between the inside and outside of the press body, which in turn due to different expansion to Cracking and thus the rejection of high-quality components can lead. The main reason for this is that the inside area of the compact developed heat due to insulation in Outside area can only be insufficiently discharged to the outside and so the already indicated temperature increases in the press caused inside the body.

Der vorliegenden Erfindung liegt die Aufgabe zugrunde, ein Ver­ fahren der eingangs genannten Art anzugeben, das bei der Entbin­ derung das Temperaturungleichgewicht zwischen dem Innen- und Außenbereich des Preßkörpers und damit Rißbildungen im Preß­ körper weitgehend unterbindet.The present invention has for its object a Ver drive of the type mentioned at the outset  the temperature imbalance between the inside and Outside of the press body and thus cracks in the press body largely prevented.

Zur Lösung dieser Aufgabe sieht die Erfindung vor, daß die Ent­ binderung in einem N2-O2-Gemisch mit maximal 20 Vol% O2, ins­ besondere 1 bis 18 Vol% O2 erfolgt, wobei der O2-Gehalt im Ge­ misch mit zunehmender Aufheizgeschwindigkeit geringer gewählt wird.To achieve this object, the invention provides that the Ent binding takes place in a N 2 -O 2 mixture with a maximum of 20 vol% O 2 , in particular 1 to 18 vol% O 2 , the O 2 content in the mixture is selected with increasing heating rate lower.

Es hat sich gezeigt, daß bei einer Entbinderung in dieser, in ihrem O2-Gehalt reduzierten Atmosphäre keine Temperaturüberhö­ hungen im Preßkörperinneren auftreten; d.h. daß die Entbin­ derung bzw. Entkohlung im Preßkörperinneren nicht rasch und da­ mit quasi nicht unter explosionsartiger Verbrennung des Sauerstoffs erfolgt.It has been shown that in the case of debinding in this atmosphere, which is reduced in its O 2 content, there are no temperature increases in the interior of the compact; that is, the debinding or decarburization in the interior of the compact does not take place quickly and with virtually no explosion of oxygen.

Was die Aufheizzeit und die hierzu in entsprechende Beziehung gesetzten O2-Gehalte im N2-O2-Gemisch betrifft, so ist beispiels­ weise bei einer Aufheizzeit von 5 Stunden (160 ... 350°C) ein O2-Gehalt von ca. 13 Vol% und bei einer Aufheizzeit von ca. 3 Stunden ein solcher von ca. 6 Vol% erforderlich.As for the heating time and this set in corresponding relationship O 2 content in the N 2 -O 2 mixture concerns, then example, at a heating time of 5 hours (160 ... 350 ° C), an O 2 content of ca 13 vol% and a heating time of approx. 3 hours requires approx. 6 vol%.

Reine Stickstoff-Atmosphäre bzw. eine Atmosphäre mit einem O2- Gehalt von weniger als 1 Vol% würde hingegen Kohlenstoffreste entstehen lassen, die beim anschließenden Sinterprozeß reduzie­ rend wirken und die magnetischen bzw. elektrischen Eigenschaften der oxidkeramischen Werkstoffe verschlechtern.A pure nitrogen atmosphere or an atmosphere with an O 2 content of less than 1% by volume, on the other hand, would leave carbon residues, which have a reducing effect in the subsequent sintering process and worsen the magnetic or electrical properties of the oxide-ceramic materials.

Claims (3)

1. Verfahren zur Entbinderung von Preßkörpern, bestehend aus feingemahlenen oxidkeramischen Werkstoffen, denen prozeßtech­ nisch bedingt organische Bestandteile, nämlich Bindemittel, Preßhilfsmittel, insbesondere Gleitmittel und Weichmacher zuge­ setzt sind, die in einem der Sinterung ggf. getrennt vorgeschal­ teten Prozeß in O2-haltiger Atmosphäre ausgebrannt werden, dadurch gekennzeichnet, daß als O2-hal­ tige Atmosphäre ein N2-O2-Gemisch mit maximal 20 Vol% O2 vor­ gesehen ist.1. A process for the debinding of compacts, consisting of finely ground oxide-ceramic materials, which are caused by process-related organic components, namely binders, pressing aids, in particular lubricants and plasticizers, which are optionally separated from the sintering process in O 2 -containing Atmosphere burned out, characterized in that an N 2 -O 2 mixture with a maximum of 20 vol% O 2 is seen as the O 2 -containing atmosphere. 2. Verfahren nach Anspruch 1, dadurch gekenn­ zeichnet, daß ein N2-O2-Gemisch mit 1 bis 18 Vol% O2 vorgesehen ist.2. The method according to claim 1, characterized in that an N 2 -O 2 mixture with 1 to 18 vol% O 2 is provided. 3. Verfahren nach Anspruch 1 und 2, dadurch ge­ kennzeichnet, daß der O2-Gehalt im N2-O2-Gemisch mit zunehmender Aufheizgeschwindigkeit geringer gewählt wird.3. The method according to claim 1 and 2, characterized in that the O 2 content in the N 2 -O 2 mixture is chosen to be lower with increasing heating rate.
DE3916630A 1989-05-22 1989-05-22 Removing organic components from pressed oxide ceramic material - by heating in nitrogen-oxygen atmos. contg. low amt. of oxygen to prevent temp. differential between inner and outer areas of body Withdrawn DE3916630A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE3916630A DE3916630A1 (en) 1989-05-22 1989-05-22 Removing organic components from pressed oxide ceramic material - by heating in nitrogen-oxygen atmos. contg. low amt. of oxygen to prevent temp. differential between inner and outer areas of body

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE3916630A DE3916630A1 (en) 1989-05-22 1989-05-22 Removing organic components from pressed oxide ceramic material - by heating in nitrogen-oxygen atmos. contg. low amt. of oxygen to prevent temp. differential between inner and outer areas of body

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DE3916630A1 true DE3916630A1 (en) 1990-11-29

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4229316A1 (en) * 1992-09-02 1994-03-03 Siemens Matsushita Components Mfr. of elongated ceramic bodies - by sintering assembly of adhesively-bonded part bodies.

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2650083A1 (en) * 1976-10-30 1978-05-03 Daimler Benz Ag non-porous silicon nitride mouldings prodn. - by moulding silicon powder and silicone resin binder, opt. hardening and nitriding
DE2944029A1 (en) * 1978-12-25 1980-07-03 Tdk Electronics Co Ltd METHOD FOR PRODUCING A SINTER BODY FROM CERAMIC MATERIAL FOR A VOLTAGE-RESISTANT RESISTANCE
DE2930847A1 (en) * 1979-07-30 1981-02-19 Nippon Crucible Co Sintered silicon carbide body - formed without sintering aid, prepd. from silicon carbide powder contg. boron component
EP0276148A2 (en) * 1987-01-20 1988-07-27 Keramont Advanced Ceramic Products Corporation Process for removing carbon or carbon compounds comprised in binders from non-oxide ceramics, and sintered bodies obtained therefrom
EP0276760A1 (en) * 1987-01-27 1988-08-03 Air Products And Chemicals, Inc. A CO2 copolymer binder for forming ceramic bodies and a shaping process using the same
EP0216436B1 (en) * 1985-09-26 1989-04-26 "Studiecentrum voor Kernenergie", "S.C.K." Method for manufacturing a sintered product

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2650083A1 (en) * 1976-10-30 1978-05-03 Daimler Benz Ag non-porous silicon nitride mouldings prodn. - by moulding silicon powder and silicone resin binder, opt. hardening and nitriding
DE2944029A1 (en) * 1978-12-25 1980-07-03 Tdk Electronics Co Ltd METHOD FOR PRODUCING A SINTER BODY FROM CERAMIC MATERIAL FOR A VOLTAGE-RESISTANT RESISTANCE
DE2930847A1 (en) * 1979-07-30 1981-02-19 Nippon Crucible Co Sintered silicon carbide body - formed without sintering aid, prepd. from silicon carbide powder contg. boron component
EP0216436B1 (en) * 1985-09-26 1989-04-26 "Studiecentrum voor Kernenergie", "S.C.K." Method for manufacturing a sintered product
EP0276148A2 (en) * 1987-01-20 1988-07-27 Keramont Advanced Ceramic Products Corporation Process for removing carbon or carbon compounds comprised in binders from non-oxide ceramics, and sintered bodies obtained therefrom
EP0276760A1 (en) * 1987-01-27 1988-08-03 Air Products And Chemicals, Inc. A CO2 copolymer binder for forming ceramic bodies and a shaping process using the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4229316A1 (en) * 1992-09-02 1994-03-03 Siemens Matsushita Components Mfr. of elongated ceramic bodies - by sintering assembly of adhesively-bonded part bodies.
DE4229316C2 (en) * 1992-09-02 1998-08-13 Siemens Matsushita Components Process for the production of elongated ceramic bodies of any geometric shape

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