WO1994007808A1 - Aqueous casting compound for producing green ceramic films and ceramic mouldings produced therefrom - Google Patents

Aqueous casting compound for producing green ceramic films and ceramic mouldings produced therefrom Download PDF

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Publication number
WO1994007808A1
WO1994007808A1 PCT/EP1993/002584 EP9302584W WO9407808A1 WO 1994007808 A1 WO1994007808 A1 WO 1994007808A1 EP 9302584 W EP9302584 W EP 9302584W WO 9407808 A1 WO9407808 A1 WO 9407808A1
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WIPO (PCT)
Prior art keywords
casting compound
meth
weight
acrylate
compound according
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PCT/EP1993/002584
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German (de)
French (fr)
Inventor
Friedrich Hessel
Ute STÜRMER
Andreas Roosen
Joseph Thevissen
Helmut Rinno
Hans Trabitzsch
Original Assignee
Hoechst Aktiengesellschaft
Röhm Gmbh
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Application filed by Hoechst Aktiengesellschaft, Röhm Gmbh filed Critical Hoechst Aktiengesellschaft
Priority to EP93921844A priority Critical patent/EP0663893A1/en
Priority to JP6508666A priority patent/JPH08501766A/en
Publication of WO1994007808A1 publication Critical patent/WO1994007808A1/en

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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
    • C04B35/63424—Polyacrylates; Polymethacrylates
    • 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
    • C04B35/6344—Copolymers containing at least three different monomers

Definitions

  • the present invention relates to a casting compound containing ceramic powder, binder and dispersion medium which is suitable for producing green ceramic films by the film casting process.
  • the film casting process essentially provides for the dispersion of fine powder in a dispersion medium, with binder and plasticizer also expediently being added at the same time.
  • the casting compound formed in this way is poured onto a moving carrier surface and forms a layer there with a layer thickness that is as uniform as possible.
  • a more or less flexible film is obtained which can be further processed into green molded parts by cutting, punching, embossing or stacking, the molded parts are then subsequently subjected to a sintering process.
  • Organic solvents or solvent mixtures are usually used as the dispersion medium for the preparation of ceramic casting compounds for shaping by the film casting process.
  • Organic solvents such as trichlorethylene, toluene, MEK, ethanol or methanol are either easily flammable or their mass use is sometimes unsafe for health reasons.
  • the object of the invention was to provide a water-based casting compound which has good water processability, i.e. which does not tend to agglomerate during its production and does not form any disruptive bonds with the mixing and pouring units, and which at the same time ensures that the green film formed therefrom has a satisfactory storage and further processing capability, i.e. Under no circumstances should embrittlement and cracks appear in the green film during storage and transport to the processing units.
  • it must always be ensured that the green film formed from the casting compound has sufficient redispersibility in order to return the waste material as recyclate to the manufacturing process of the green film and thus to maintain the economical production of ceramic molded parts.
  • a casting compound of the type mentioned essentially contains water as a dispersion medium and that it contains, as a binder, an emulsion copolymer which comprises 95 to 75% by weight of esters of acrylic and / or methacrylic acid and is 5 to 25 wt .-% of ⁇ ,? -ethylenically unsaturated carboxylic acids, in an amount of 2.0 to 10 wt .-%, based on the total weight of the casting composition, the emulsion copolymer in Form of microspheres with an average particle size, expressed as weight average d w , in the range from 75 to 150 nm.
  • esters of acrylic or methacrylic acid are methyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyl (meth) acrylate, Glycidyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, tert-butyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide and (meth) acrylonitrile, while mentioning as ⁇ , ß-ethylenically unsaturated carboxylic acids in addition to acrylic acid and methacrylic acid also crotonic acid, maleic acid, itaconic acid or their half esters can be used.
  • the particle size distribution of the microspheres of the emulsion copolymer should preferably be narrow, in particular the quotient of the weight-average particle size d w and the number-average particle size d n should be a value of less than 1.3.
  • the particle size distribution d w / d n is a measure for assessing the uniformity of dispersion particles. It is defined as the quotient of the weight average of the particle diameter d w and its number average d n . If the particles are completely uniform, the quotient can assume the value 1, inconsistencies result in numerical values greater than 1 (see UEWoods et al., Journal of paint technology, Vol. 40, No. 527 (1968), page 545).
  • the particle size can be measured by known methods, for example by electron microscopy (SHMaron et al., Journal of applied Physics Vol. 23, (1952), p. 900).
  • the emulsion copolymers suitable as binders should preferably have a glass transition temperature T g in the range from -10 to + 10 ° C. Your minimum film forming temperature (MFT) should be between 0 and 5 ° C.
  • the acid content of the emulsion copolymers is preferably between 15 and 25 mol%.
  • the binder suitable for the casting composition according to the invention can contain, in addition to the emulsion copolymer, further water-soluble binders up to a maximum amount of 2% by weight, based on the total weight of the casting composition.
  • Water-soluble binders can contain both ionic polymers such as polyacrylic / methacrylic acid salts, copolymers such as polyacrylic / methacrylic ester / acid mixtures, cellulose derivatives or similar and non-ionic products such as polyvinyl alcohol, polyacrylamide or cellulose ether.
  • a good solubility of the binder results in good redispersibility, which at the same time results in a high sensitivity to moisture in the green film and can therefore have a negative effect on the physical properties of the green film, in particular on storage behavior.
  • a binder with a low sensitivity to moisture is selected, serious problems with the redispersion of waste material can result and the production shifts towards inefficiency.
  • a high solids content in the casting compound is important for achieving a high green density, but a high solids content also inevitably leads to viscosity and processing problems.
  • a higher drying temperature can adversely affect the redispersion behavior.
  • Good re-dispersibility of the green sheets must be provided for the reprocessing of film waste.
  • the binder should preferably be present in an amount of 3.0 to 6.0% by weight.
  • Glycerin, mono- or diethylene glycol or polyethylene glycol may also be present as plasticizers in the casting composition according to the invention, the plasticizing agents mentioned being present in the casting composition in an amount of 0 to 2.0% by weight, based on the total weight of the casting composition.
  • Suitable ceramic materials that are suitable for the casting compound according to the invention are metal oxides or non-oxides, which usually play a role in the production of ceramic molded parts for technical applications.
  • the ceramic powders can be used both alone and in mixtures.
  • Particularly typical ceramic powders include the oxides, carbides, nitrides, borides and sulfides of lithium, potassium, beryllium, magnesium, Boron, aluminum, silicon, copper, calcium, strontium, barium, zinc, cadmium, gallium, indium, titanium, zircon, bismuth or manganese.
  • the said ceramic powders can be contained in the casting compound in amounts of 70 to 85% by weight, preferably 75 to 80% by weight, based in each case on the total weight of the casting compound.
  • the dispersion medium for the casting compound according to the invention is essentially water and is used in an amount in the range from 15 to 20% by weight, based on the total weight of the casting compound. Smaller amounts of alcohol, higher-quality alcohol or silicones can be added to the dispersion medium as defoamers, smaller amounts of up to 0.5% by weight, preferably up to 0.1% by weight, based on the total weight of those used, according to the invention Casting compound to be understood.
  • a dispersant is added to stabilize the ceramic powder particles in solution to prevent sedimentation.
  • Salts of ⁇ , ⁇ -ethylenically unsaturated carboxylic acids, ionic and nonionic surfactants or carboxylic acid mixtures can be used as dispersants.
  • the casting compound according to the invention offers particular advantages in achieving a uniform film surface.
  • the H O content of the casting composition according to the invention is low in comparison with the literature, which at the same time results in a high solids content, and that nevertheless a readily processable composition can be obtained.
  • the casting compound according to the invention produces ceramic films with a high green density and thus a low sintering shrinkage.
  • Hostapal BV 50% sulfuric acid half ester of an ethoxylated
  • the result is an emulsion copolymer of methyl methacrylate, butyl acrylate and methacrylic acid / acrylic acid in a weight ratio of 35:65:10 and with a weight-average particle size of 120 nm and a particle size distribution d w / d n of 1.18.
  • ⁇ (ammonium polyacrylate, e.g. Dolapix CA, manufacturer Zschimmer and Schwarz,
  • ® rotational viscometer Haake RV 50, Fa. Häake
  • the slip is cast on a laboratory film casting machine, dried in a drying channel with preheated air up to 90 ° C in the counterflow principle.
  • the green film obtained (0.8 mm thick) is characterized by the green density. For this purpose, 3 test pieces are punched out of the film, precisely measured and weighed, and the green density is thus determined geometrically.
  • the surface of the film can be characterized by viewing it against the light. Specks or holes can be easily recognized.
  • test pieces are punched out of the green film obtained, measured and sintered at 1600 ° C. to form a dense body. The sintering shrinkage is determined by measuring the ceramic parts obtained.
  • a piece of green film is mixed with the amount of water from the original slip mixture and ground in a mortar. After 3 minutes, the slip obtained is poured out. If a lump-free film with comparable flexibility to the original film is created, it is recyclable. If a lumpy or brittle film is formed, it cannot be recycled.
  • Example 1 According to Example 1, a green sheet was obtained which had a green density of 2.40 g / cm 3 .
  • the green film was free of specks and was easy to recycle.
  • the sintering shrinkage was 19.5%.
  • Example 1 an emulsion copolymer was prepared which contained the same monomer units as in Example 1, but in a weight ratio of 50: 50: 3.
  • the green sheet produced with this emulsion copolymer in accordance with Example 1 had a spotty surface and was not recyclable.
  • Example 1 an emulsion copolymer of the same composition was produced, but with a weight-average particle size of 200 nm.
  • the slip produced with this emulsion copolymer in accordance with Example 1 showed a high tendency to dilatancy, which means increasing viscosity with increasing shear; therefore this slip could not be processed further.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Compositions Of Oxide Ceramics (AREA)

Abstract

The invention relates to a casting compound containing ceramic powder, binders and a dispersing agent suitable for producing green ceramic films by the film casting process. Its dispersing agent is essentially water and the binder is an emulsion copolymer made up of 95 to 75 wt.% acrylic or methacrylic acid esters and 5 to 25 wt.% (alpha),(beta) ethylenically unsaturated carboxylic acids in a proportion of 2.0 to 10 wt.% in relation to the total weight of the casting compound. Said emulsion copolymer is according to the invention in the form of microbeads with an average particle size, expressed in average weight dw, in the range of 75 to 150 nm.

Description

Beschreibungdescription
Wäßrige Gießmasse zur Herstellung von grünen Keramikfolien und daraus hergestellte KeramikformteileAqueous casting compound for the production of green ceramic films and ceramic molded parts made therefrom
Die vorliegende Erfindung betrifft eine Gießmasse enthaltend keramisches Pulver, Bindemittel und Dispersionsmedium, die sich dazu eignet um nach dem Foliengießverfahren grüne Keramikfolien herzustellen.The present invention relates to a casting compound containing ceramic powder, binder and dispersion medium which is suitable for producing green ceramic films by the film casting process.
Das Foliengießverfahren sieht im wesentlichen die Dispergierung von feinem Pulver in einem Dispersionsmedium vor, wobei gleichzeitig zweckmäßigerweise außerdem noch Bindemittel und Plastifiziermittel zugesetzt werden. Die so gebildete Gießmasse wird auf eine sich bewegende Trägeroberfläche gegossen und bildet dort eine Schicht mit möglichst gleichmäßiger Schichtdicke. Nach dem Verdampfen des Dispersionsmediums wird eine mehr oder minder flexible Folie erhalten, die durch Schneiden, Stanzen, Prägen oder Stapeln zu grünen Formteilen weiterverarbeitet werden kann, die Formteile werden dann anschließend einem Sinterprozess unterworfen. Zur Aufbereitung von keramischen Gießmassen für die Formgebung durch das Foliengießverfahren werden üblicherweise organische Lösemittel oder Lösemittelgemische als Dispersionsmedium eingesetzt. Organische Lösemittel wie Trichlorethylen, Toluol, MEK, Ethanol oder Methanol sind aber entweder leicht brennbar oder ihr massenhafter Einsatz ist teilweise aus gesundheitlichen Gründen bedenklich.The film casting process essentially provides for the dispersion of fine powder in a dispersion medium, with binder and plasticizer also expediently being added at the same time. The casting compound formed in this way is poured onto a moving carrier surface and forms a layer there with a layer thickness that is as uniform as possible. After the evaporation of the dispersion medium, a more or less flexible film is obtained which can be further processed into green molded parts by cutting, punching, embossing or stacking, the molded parts are then subsequently subjected to a sintering process. Organic solvents or solvent mixtures are usually used as the dispersion medium for the preparation of ceramic casting compounds for shaping by the film casting process. Organic solvents such as trichlorethylene, toluene, MEK, ethanol or methanol are either easily flammable or their mass use is sometimes unsafe for health reasons.
Um die Produktionsbedingungen und Produktionssicherheit in den Herstellungsbetrieben zu verbessern, sucht man schon lange nach geeigneten Möglichkeiten, die organischen Dispersionsmedien solcher Gießmassen durch Wasser völlig oder wenigstens teilweise zu substituieren. Die japanischen Patentpublikationen 180 955/1985 und 180 956/1985 beschreiben zwar schon wäßrige Gießschlicker, die dort beschriebenen Zusammensetzungen lassen aber mitunter noch zu wünschen übrig, was ihre Verarbeitbarkeit und ihre Recyclierbarkeit betrifft.In order to improve the production conditions and production security in the manufacturing companies, it has long been looking for suitable ways to completely or at least partially replace the organic dispersion media of such casting compounds with water. The Japanese patent publications 180 955/1985 and 180 956/1985 already describe aqueous casting slurries, but the compositions described therein sometimes still leave something to be desired in terms of their processability and recyclability.
Aufgabe der Erfindung war es, eine Gießmasse auf Wasserbasis zu schaffen, die eine gute Wasserverarbeitbarkeit besitzt, d.h. die bei ihrer Herstellung nicht zu Agglomeration neigt und auch mit den Misch- und Gießaggregaten keine störenden Verklebungen bildet, und die gleichzeitig gewährleistet, daß die daraus gebildete Grünfolie eine zufriedenstellende Lager- und Weiterverarbeitungsfähigkeit besitzt, d.h. es darf während des Lagerns und des Transportes im Betrieb zu den Weiterverarbeitungsaggregaten keinesfalls zu Versprödungserscheinungen und Rißbildungen in der grünen Folie kommen. Darüber hinaus muß immer gewährleistet sein, daß die aus der Gießmasse gebildete Grünfolie eine ausreichende Redispergierbarkeit besitzt, um das Verschnittmaterial als Recyclat wieder zu dem Herstellungsprozess der Grünfolie zurückzuführen und so eine wirtschafliche Produktion von keramischen Formteilen aufrechtzuerhalten.The object of the invention was to provide a water-based casting compound which has good water processability, i.e. which does not tend to agglomerate during its production and does not form any disruptive bonds with the mixing and pouring units, and which at the same time ensures that the green film formed therefrom has a satisfactory storage and further processing capability, i.e. Under no circumstances should embrittlement and cracks appear in the green film during storage and transport to the processing units. In addition, it must always be ensured that the green film formed from the casting compound has sufficient redispersibility in order to return the waste material as recyclate to the manufacturing process of the green film and thus to maintain the economical production of ceramic molded parts.
Gelöst wird diese Aufgabe durch eine Gießmasse der eingangs genannten Gattung, deren Kennzeichenmerkmal darin zu sehen ist, daß sie als Dispersionsmedium im wesentlichen Wasser enthält und daß sie als Bindemittel ein Emulsionscopolymerisat, das zu 95 bis 75 Gew.-% aus Estern der Acryl- und/oder Methacrylsäure und zu 5 bis 25 Gew.-% aus σ, ?-ethylenisch ungesättigten Carbonsäuren aufgebaut ist, in einer Menge von 2,0 bis 10 Gew.- %, bezogen auf das Gesamtgewicht der Gießmasse, enthält, wobei das Emulsionscopolymerisat in Form von Mikrosphären mit einer mittleren Teilchengröße, ausgedrückt als Gewichtsmittel dw, im Bereich von 75 bis 150 nm vorliegt.This object is achieved by a casting compound of the type mentioned, the distinguishing feature of which can be seen in the fact that it essentially contains water as a dispersion medium and that it contains, as a binder, an emulsion copolymer which comprises 95 to 75% by weight of esters of acrylic and / or methacrylic acid and is 5 to 25 wt .-% of σ,? -ethylenically unsaturated carboxylic acids, in an amount of 2.0 to 10 wt .-%, based on the total weight of the casting composition, the emulsion copolymer in Form of microspheres with an average particle size, expressed as weight average d w , in the range from 75 to 150 nm.
Als Ester der Acryl- oder Methacrylsäure sind insbesondere Methyl(meth)acrylat, n-Butyl(meth)acrylat, 2-Ethlyhexyl(meth)acrylat, Ethyl(meth)acrylat, Glycidyl(meth)acrylat, Hydroxyethyl(meth)acrylat, Hydroxypropyl(meth)acrylat, tert.-Butyl(meth)acrylat, (Meth)acrylamid, N-Methylol(meth)acrylamid und (Meth)acrylnitril zu nennen, während als σ,ß-ethylenisch ungesättigte Carbonsäuren neben Acrylsäure und Methacrylsäure auch noch Crotonsäure, Maleinsäure, Itakonsäure oder deren Halbester in Frage kommen können.Particularly suitable esters of acrylic or methacrylic acid are methyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyl (meth) acrylate, Glycidyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, tert-butyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide and (meth) acrylonitrile, while mentioning as σ , ß-ethylenically unsaturated carboxylic acids in addition to acrylic acid and methacrylic acid also crotonic acid, maleic acid, itaconic acid or their half esters can be used.
Vorzugsweise soll die Teilchengrößenverteilung der Mikrosphären des Emulsionscopolymerisates eng sein, insbesondere soll der Quotient aus der gewichtsmittleren Teilchengröße dw und der zahlenmittleren Teilchengröße dn einen Wert von kleiner 1 ,3 ergeben. Die Teilchengrößenverteilung dw/dn ist eine Maßzahl zur Beurteilung der Einheitlichkeit von Dispersionspartikeln. Sie ist definiert als der Quotient aus dem Gewichtsmittel der Teilchendurchmesser dw und ihrem Zahlenmittel dn. Wenn die Teilchen völlig einheitlich sind kann der Quotient den Wert 1 annehmen, Uneinheitlichkeiten ergeben Zahlenwerte größer als 1 (vergl. U.E.Woods et al., Journal of paint technology, Vol. 40, Nr. 527 (1968), Seite 545). Die Messung der Teilchengröße kann nach bekannten Methoden erfolgen, beispielsweise elektronenmikroskopisch (S.H.Maron et al., Journal of applied Physics Vol. 23, (1952), S. 900).The particle size distribution of the microspheres of the emulsion copolymer should preferably be narrow, in particular the quotient of the weight-average particle size d w and the number-average particle size d n should be a value of less than 1.3. The particle size distribution d w / d n is a measure for assessing the uniformity of dispersion particles. It is defined as the quotient of the weight average of the particle diameter d w and its number average d n . If the particles are completely uniform, the quotient can assume the value 1, inconsistencies result in numerical values greater than 1 (see UEWoods et al., Journal of paint technology, Vol. 40, No. 527 (1968), page 545). The particle size can be measured by known methods, for example by electron microscopy (SHMaron et al., Journal of applied Physics Vol. 23, (1952), p. 900).
Vorzugsweise sollen die als Bindemittel geeigneten Emulsionscopolymerisate eine Glastemperatur Tg im Bereich von -10 bis + 10 °C aufweisen. Ihre minimale Filmbildetemperatur (MFT) soll zwischen 0 und 5 °C liegen. Der Säuregehalt der Emulsionscopolymerisate liegt bevorzugt zwischen 15 und 25 mol%.The emulsion copolymers suitable as binders should preferably have a glass transition temperature T g in the range from -10 to + 10 ° C. Your minimum film forming temperature (MFT) should be between 0 and 5 ° C. The acid content of the emulsion copolymers is preferably between 15 and 25 mol%.
Das für die erfindungsgemäße Gießmasse geeignete Bindemittel kann zusätzlich zu dem Emulsionscopolymerisat noch weitere wasserlösliche Binder bis zu einer Maximalmenge von 2 Gew.-%, bezogen auf das Gesamtgewicht der Gießmasse, enthalten. Wasserlösliche Binder können sowohl ionische Polymere wie Polyacryl/methacrylsäuresalze, Copolymere wie Polyacryl/methacrylEster/säure- Gemische, Cellulosederivate oder ähnliche und nicht-ionische Produkte wie Polyvinylalkohol, Polyacrylamid oder Celluloseether enthalten. Damit ein Bindemittel für den Foliengießprozeß geeignet ist, sind viele verschiedene Anforderungen in Kombination zu erfüllen. Aus den teilweise widersprüchlichen Anforderungen ergeben sich kritische Faktoren für die Zusammensetzung einer konkreten Rezeptur zum Foliengießen auf Wasserbasis. Eine gute Löslichkeit des Bindemittels hat eine gute Redispergierbarkeit zur Folge, was aber gleichzeitig eine hohe Feuchtigkeitsempfindlichkeit der Grünfolie zur Folge hat und deshalb die physikalischen Eigenschaften der Grünfolie, insbesondere das Lagerverhalten, negativ beeinflussen kann. Wird hingegen ein Bindemittel mit einer niedrigen Feuchtigkeitsempfindlichkeit ausgewählt, können ernste Probleme beim Redispergieren von Verschnittmaterial daraus resultieren und die Produktion verschiebt sich hin zu UnWirtschaftlichkeit. Ein hoher Feststoffgehalt in der Gießmasse ist wichtig für das Erreichen einer hohen Gründichte, aber ein hoher Feststoffgehalt führt zwangsläufig auch zu Viskositäts- und Verarbeitungsproblemen. Eine höhere Trocknungstemperatur kann sich nachteilig auf das Redispergierverhalten auswirken. Zur Wiederaufbereitung von Folienverschnitt muß eine gute Redispergierbarkeit der Grünfolien gegeben sein.The binder suitable for the casting composition according to the invention can contain, in addition to the emulsion copolymer, further water-soluble binders up to a maximum amount of 2% by weight, based on the total weight of the casting composition. Water-soluble binders can contain both ionic polymers such as polyacrylic / methacrylic acid salts, copolymers such as polyacrylic / methacrylic ester / acid mixtures, cellulose derivatives or similar and non-ionic products such as polyvinyl alcohol, polyacrylamide or cellulose ether. In order for a binder to be suitable for the film casting process, many different requirements have to be met in combination. The sometimes contradicting requirements result in critical factors for the composition of a concrete formulation for water-based film casting. A good solubility of the binder results in good redispersibility, which at the same time results in a high sensitivity to moisture in the green film and can therefore have a negative effect on the physical properties of the green film, in particular on storage behavior. On the other hand, if a binder with a low sensitivity to moisture is selected, serious problems with the redispersion of waste material can result and the production shifts towards inefficiency. A high solids content in the casting compound is important for achieving a high green density, but a high solids content also inevitably leads to viscosity and processing problems. A higher drying temperature can adversely affect the redispersion behavior. Good re-dispersibility of the green sheets must be provided for the reprocessing of film waste.
Um eine gießfähige Rezeptur der Masse zu gewähleisten soll das Bindemittel vorzugsweise in einer Menge von 3,0 bis 6,0 Gew.-% enthalten sein.In order to ensure a pourable formulation of the composition, the binder should preferably be present in an amount of 3.0 to 6.0% by weight.
Als Plastifiziermittel können in der erfindungsgemäßen Gießmasse weiterhin Glycerin, Mono- oder Diethylenglykol oder Polyethylenglykol enthalten sein, wobei die genannten Plastifiziermittel in einer Menge von 0 bis 2,0 Gew-% in der Gießmasse enthalten sind, bezogen auf das Gesamtgewicht der Gießmasse.Glycerin, mono- or diethylene glycol or polyethylene glycol may also be present as plasticizers in the casting composition according to the invention, the plasticizing agents mentioned being present in the casting composition in an amount of 0 to 2.0% by weight, based on the total weight of the casting composition.
Als keramische Materialien, die sich für die erfindungsgemäße Gießmasse eignen kommen Metalloxide oder -nichtoxide in Betracht, die üblicherweise in der Produktion keramischer Formteile für technische Anwendungen eine Rolle spielen. Die keramischen Pulver können sowohl alleine wie auch in Mischungen eingesetzt werden. Besonders typische Keramikpulver umfassen die Oxide, Karbide, Nitride, Boride und Sulfide von Lithium, Kalium Beryllium, Magnesium, Bor, Aluminium, Silizium, Kupfer, Kalzium, Strontium, Barium, Zink, Cadmium, Gallium, Indium, Titan, Zirkon, Wismut oder Mangan. Die genannten keramischen Pulver können erfindungsgemäß in der Gießmasse in Mengen von 70 bis 85 Gew.-%, vorzugsweise von 75 bis 80 Gew.-%, enthalten sein, bezogen jeweils auf das Gesamtgewicht der Gießmasse.Suitable ceramic materials that are suitable for the casting compound according to the invention are metal oxides or non-oxides, which usually play a role in the production of ceramic molded parts for technical applications. The ceramic powders can be used both alone and in mixtures. Particularly typical ceramic powders include the oxides, carbides, nitrides, borides and sulfides of lithium, potassium, beryllium, magnesium, Boron, aluminum, silicon, copper, calcium, strontium, barium, zinc, cadmium, gallium, indium, titanium, zircon, bismuth or manganese. According to the invention, the said ceramic powders can be contained in the casting compound in amounts of 70 to 85% by weight, preferably 75 to 80% by weight, based in each case on the total weight of the casting compound.
Das Dispersionsmedium für die erfindungsgemäße Gießmasse ist im wesentlichen Wasser und wird in einer Menge im Bereich von 15 bis 20 Gew.- %, bezogen auf das Gesamtgewicht der Gießmasse, eingesetzt. Als Entschäumer können dem Dispersionsmedium kleinere Mengen an Alkohol, höherwertigem Alkohol oder an Silikonen zugesetzt sein, wobei unter kleineren Mengen erfindungsgemäß bis zu 0,5 Gew.-%, vorzugsweise bis zu 0,1 Gew.-%, bezogen auf das Gesamtgewicht der eingesetzten Gießmasse, verstanden werden sollen.The dispersion medium for the casting compound according to the invention is essentially water and is used in an amount in the range from 15 to 20% by weight, based on the total weight of the casting compound. Smaller amounts of alcohol, higher-quality alcohol or silicones can be added to the dispersion medium as defoamers, smaller amounts of up to 0.5% by weight, preferably up to 0.1% by weight, based on the total weight of those used, according to the invention Casting compound to be understood.
Zur Stabilisierung der keramischen Pulverteilchen in Lösung wird ein Dispergiermittel zugesetzt, um eine Sedimentation zu verhindern. Als Dispergiermittel können Salze von σ,ß-ethylenisch ungesättigten Carbonsäuren, ionische und nichtionische Tenside oder Carbonsäuregemische eingesetzt werden.A dispersant is added to stabilize the ceramic powder particles in solution to prevent sedimentation. Salts of σ, β-ethylenically unsaturated carboxylic acids, ionic and nonionic surfactants or carboxylic acid mixtures can be used as dispersants.
Für eine produktionsgerechte Verarbeitbarkeit von keramischen Gießmassen für das Foliengießen müssen verschiedene Anforderungen erfüllt sein: wasserverarbeitbar hoher Feststoffgehalt keramischer Pulver im Schlicker gute Verarbeitbarkeit (Viskosität von 1500 mPa-s bis 15000 mPa«s, besonders 1500 mPa-s bis 5000 mPa-s; Lagerfähigkeit des SchlickersVarious requirements must be met to ensure that ceramic casting compounds for film casting can be processed in line with production requirements: water-processable, high solids content of ceramic powder in the slip good processability (viscosity from 1500 mPa-s to 15000 mPa «s, especially 1500 mPa-s to 5000 mPa-s; storage life of the slip
>3 Tage) hohe Gießgeschwindigkeit / gutes Trocknungsverhalten> 3 days) high casting speed / good drying behavior
Ablöseverhalten von der Gießunterlage mechanische Eigenschaften / FlexibilitätDetachment behavior from the casting base mechanical properties / flexibility
Lagerfähigkeit der Grünfolie (geringe H2O-Aufnahme) Redispergierbarkeit der Grünfolie Ausbrennverhalten der organischen Additive.Storage life of the green sheet (low H 2 O absorption) Redispersibility of the green sheet Burn-out behavior of the organic additives.
Überraschend wurde gefunden, daß die erfindungsgemäße Gießmasse besondere Vorteile beim Erreichen einer gleichmäßigen Folienoberfläche bietet. Außerdem zeigte sich, daß ein im Vergleich zu Literaturangaben niedriger H O- Gehalt der erfindungsgemäßen Gießmasse möglich ist, woraus gleichzeitig ein hoher Feststoffgehalt resultiert, und daß trotzdem eine gut verarbeitbare Masse erhalten werden kann. Die erfindungsgemäße Gießmasse ergibt keramische Folien mit einer hohen Gründichte und damit niedriger Sinterschwindung.Surprisingly, it was found that the casting compound according to the invention offers particular advantages in achieving a uniform film surface. In addition, it was found that the H O content of the casting composition according to the invention is low in comparison with the literature, which at the same time results in a high solids content, and that nevertheless a readily processable composition can be obtained. The casting compound according to the invention produces ceramic films with a high green density and thus a low sintering shrinkage.
Die Erfindung soll nachfolgend anhand von Ausführungsbeispielen noch näher erläutert werden, ohne aber auf die konkret dargestellten Ausführungsformen beschränkt zu sein.The invention is to be explained in more detail below on the basis of exemplary embodiments, but without being restricted to the specifically illustrated embodiments.
Beispiel 1example 1
In einem Reaktionsbehälter mit Rührer werden 410 Volumenteile Wasser mit 7,5410 volumes of water with 7.5
Gew.-Teilen Emulgator (erhältlich bei der Hoechst AG unter der BezeichnungParts by weight of emulsifier (available from Hoechst AG under the name
® Hostapal BV 50%ig = Schwefelsäurehalbester eines ethoxylierten® Hostapal BV 50% = sulfuric acid half ester of an ethoxylated
Alkylphenols) unter intensivem Rühren auf eine Temperatur von 83 °C erhitzt. Dann werden 30 Gew.-Teile einer Monomeremulsion zusammen mit 0,28 Gew.- Teilen Ammoniumpersulfat in den Reaktionsbehälter eingelassen und über eineAlkylphenols) heated to a temperature of 83 ° C with vigorous stirring. Then 30 parts by weight of a monomer emulsion together with 0.28 parts by weight of ammonium persulfate are introduced into the reaction vessel and passed over a
Zeitspanne von 15 Minuten vorpolymerisiert. Die Monomeremulsion setzt sichPrepolymerized for 15 minutes. The monomer emulsion settles
® zusammen aus 360 Gew.-Teilen Wasser, 15 Gew.-Teile Hostapal BV 50%ig,® together from 360 parts by weight of water, 15 parts by weight of Hostapal BV 50%,
33,7 Gew.-Teile Acrylsäure, 41 ,2 Gew.-Teile Methacrylsäure, 2,7 Gew.-Teile Ammoniumpersulfat, 487 Gew.-Teile Butylacrylat und 262 Gew.-Teile Methylmethacrylat. Nach der Vorpolymerisationszeit wird der restliche Anteil an Monomeremulsion langsam über eine Zeitspanne von 3,5 Stunden zugeführt. Wenn der ganze Reaktionsansatz vereinigt ist, läßt man über eine weitere Zeitspanne von 2,5 Stunden bei einer Temperatur von 83 °C nachreagieren, dann wird auf Raumtemperatur abgekühlt. Das Ergebnis ist ein Emulsionscopolymersiat aus Methylmethacrylat, Butylacrylat und Methacrylsäure/Acrylsäure im Gewichtsverhältnis 35 : 65 : 10 und mit einer gewichtsmittleren Teilchengröße von 120 nm und einer Teilchengrößenverteilung dw/dn von 1 ,18.33.7 parts by weight of acrylic acid, 41.2 parts by weight of methacrylic acid, 2.7 parts by weight of ammonium persulfate, 487 parts by weight of butyl acrylate and 262 parts by weight of methyl methacrylate. After the prepolymerization period, the remainder of the monomer emulsion is slowly added over a period of 3.5 hours. When the entire reaction mixture has been combined, the mixture is left to react for a further period of 2.5 hours at a temperature of 83 ° C. then it is cooled to room temperature. The result is an emulsion copolymer of methyl methacrylate, butyl acrylate and methacrylic acid / acrylic acid in a weight ratio of 35:65:10 and with a weight-average particle size of 120 nm and a particle size distribution d w / d n of 1.18.
Schlickerzubereitung:Preparation of slip:
In einer 5 I Kugelmühle werden 587,5 g Wasser, 60 g Dispergiermittel587.5 g of water and 60 g of dispersant are added to a 5 l ball mill
© (Ammoniumpolyacrylat, z.B. Dolapix CA, Hersteller Zschimmer und Schwarz,© (ammonium polyacrylate, e.g. Dolapix CA, manufacturer Zschimmer and Schwarz,
25%ig) mit 1950 g AI2O3 versetzt und 3900 g Mahlkörper vordispergiert. Nach 2 bis 4 h werden 1950 g AI2O3, 350 g des Dispersionsbinders (Feststoffgehalt 50%) und 37,5 g eines Weichmachers (z.B. PEG 400 oder PEG 600, Hersteller Hoechst AG) zugefügt und 24 h auf einem Rollenbock aufbereitet. Vor der Entleerung der Mühle wird ein Entschäumer zugesetzt und weitere 15 min aufgerollt. Der erhaltene Schlicker wird im Vakuum von Luftblasen befreit. Zur25%) with 1950 g Al 2 O 3 and 3900 g grinding media predispersed. After 2 to 4 hours, 1950 g of Al 2 O 3 , 350 g of the dispersion binder (solids content 50%) and 37.5 g of a plasticizer (for example PEG 400 or PEG 600, manufacturer Hoechst AG) are added and processed on a roller stand for 24 hours. Before the mill is emptied, a defoamer is added and rolled up for a further 15 min. The slip obtained is freed of air bubbles in vacuo. to
Charakterisierung des Schlickers wird die Viskosität mit Hilfe einesCharacterization of the slip is carried out using a viscosity
® Rotationsviskosimeters ( Haake RV 50, Fa. Häake) bestimmt. Der Schlicker wird auf einer Laborfoliengießanlage vergossen, in einem Trocknungskanal mit vorgewärmter Luft bis 90°C im Gegenstromprinzip getrocknet. Die erhaltene Grünfolie (0,8 mm dick) wird durch die Gründichte charakterisiert. Dazu werden aus der Folie 3 Probestücke ausgestanzt, exakt vermessen und gewogen und die Gründichte so geometrisch bestimmt.® rotational viscometer (Haake RV 50, Fa. Häake) determined. The slip is cast on a laboratory film casting machine, dried in a drying channel with preheated air up to 90 ° C in the counterflow principle. The green film obtained (0.8 mm thick) is characterized by the green density. For this purpose, 3 test pieces are punched out of the film, precisely measured and weighed, and the green density is thus determined geometrically.
Die Oberfläche der Folie kann durch Betrachten im Gegenlicht charakterisiert werden. Stippen oder Löcher können gut erkannt werden.The surface of the film can be characterized by viewing it against the light. Specks or holes can be easily recognized.
Aus der erhaltenen Grünfolie werden mehrere Probestücke ausgestanzt, vermessen und bei 1600°C zu einem dichten Körper gesintert. Die Sinterschwindung wird durch Ausmessen der erhaltenen Keramikteile bestimmt. Zum Testen der Recyclierungseigenschaften wird ein Stück Grünfolie mit der Menge Wasser aus dem ursprünglichen Schlickeransatz versetzt und in einem Mörser zerrieben. Nach 3 min wird der erhaltene Schlicker ausgegossen. Wenn eine klumpenfreie Folie mit vergleichbarer Flexibilität zur Ausgangsfolie entsteht, ist die Recyclingfähigkeit gegeben. Entsteht eine klumpige oder brüchige Folie, ist die Recyclingfähigkeit nicht gegeben.Several test pieces are punched out of the green film obtained, measured and sintered at 1600 ° C. to form a dense body. The sintering shrinkage is determined by measuring the ceramic parts obtained. To test the recycling properties, a piece of green film is mixed with the amount of water from the original slip mixture and ground in a mortar. After 3 minutes, the slip obtained is poured out. If a lump-free film with comparable flexibility to the original film is created, it is recyclable. If a lumpy or brittle film is formed, it cannot be recycled.
Ergebnis: Nach Beispiel 1 wurde eine Grünfolie erhalten, die eine Gründichte von 2,40 g/cm3 besaß. Die Grünfolie war frei von Stippen und ließ sich einwandfrei recyclieren. Die Sinterschwindung betrug 19,5 %.Result: According to Example 1, a green sheet was obtained which had a green density of 2.40 g / cm 3 . The green film was free of specks and was easy to recycle. The sintering shrinkage was 19.5%.
Beispiel 2 (Vergleichsbeispiel)Example 2 (comparative example)
Wie in Beispiel 1 wurde ein Emulsionscopolymerisat hergestellt, das die gleichen Monomereinheiten wie in Beispiel 1 enthielt, aber in einem Gewichtsverhältnis von 50 : 50 : 3. Die mit diesem Emulsionscopolymerisat im Anklang an Beispiel 1 hergestellte Grünfolie zeigte eine stippige Oberfläche und war nicht recyclierbar.As in Example 1, an emulsion copolymer was prepared which contained the same monomer units as in Example 1, but in a weight ratio of 50: 50: 3. The green sheet produced with this emulsion copolymer in accordance with Example 1 had a spotty surface and was not recyclable.
Beispiel 3 (Vergleichsbeispiel)Example 3 (comparative example)
Wie in Beispiel 1 wurde ein Emulsionscopolymerisat gleicher Zusammensetzung hergestellt, das aber eine gewichtsmittlere Teilchengröße von 200 nm besaß. Der mit diesem Emulsionscopolymerisat im Anklang an Beispiel 1 hergestellte Schlicker zeigte eine hohe Neigung zur Dilatanz, das bedeutet zunehmende Viskosität bei zunehmender Scherung; deshalb konnte dieser Schlicker nicht weiterverarbeitet werden. As in Example 1, an emulsion copolymer of the same composition was produced, but with a weight-average particle size of 200 nm. The slip produced with this emulsion copolymer in accordance with Example 1 showed a high tendency to dilatancy, which means increasing viscosity with increasing shear; therefore this slip could not be processed further.

Claims

Patentansprüche: Claims:
1. Gießmasse enthaltend keramisches Pulver, Bindemittel und Dispersionsmedium, die sich dazu eignet um nach dem Foliengießverfahren grüne Keramikfolien herzustellen, dadurch gekennzeichnet, daß sie als Dispersionsmedium im wesentlichen Wasser enthält und daß sie als Bindemittel ein Emulsionscopolymerisat, das zu 95 bis 75 Gew.-% aus Estern der Acryl- und/oder Methacrylsäure und zu 5 bis 25 Gew.-% aus σ, ?-ethylenisch ungesättigten Carbonsäuren aufgebaut ist, in einer Menge von 2,0 bis 10 Gew.- %, bezogen auf das Gesamtgewicht der Gießmasse, enthält, wobei das Emulsionscopolymerisat in Form von Mikrosphären mit einer mittleren Teilchengröße, ausgedrückt als Gewichtsmittel dw, im Bereich von 75 bis 150 nm vorliegt.1. Casting compound containing ceramic powder, binder and dispersion medium, which is suitable for producing green ceramic films by the film casting process, characterized in that it essentially contains water as the dispersion medium and that it contains, as a binder, an emulsion copolymer which comprises 95 to 75% by weight. % is composed of esters of acrylic and / or methacrylic acid and 5 to 25% by weight of σ,? -ethylenically unsaturated carboxylic acids in an amount of 2.0 to 10% by weight, based on the total weight of the casting compound , contains, wherein the emulsion copolymer is in the form of microspheres with an average particle size, expressed as weight average d w , in the range from 75 to 150 nm.
2. Gießmasse nach Anspruch 1 , dadurch gekennzeichnet, daß sie als Ester der Acryl- oder Methacrylsäure Methyl(meth)acrylat, n-Butyl(meth)acrylat, 2- Ethlyhexyl(meth)acrylat, Ethyl(meth)acrylat, Glycidyl(meth)acrylat, Hydroxyethyl(meth)acrylat, Hydroxypropyl(meth)acrylat, tert.- Butyl(meth)acrylat, (Meth)acrylamid, N-Methylol(meth)acrylamid oder (Meth)acrylnitril enthält, und daß sie als σ,ß-ethylenisch ungesättigte Carbonsäuren neben Acrylsäure und Methacrylsäure auch noch Crotonsäure, Maleinsäure Itakonsäure oder deren Halbester enthält.2. Casting compound according to claim 1, characterized in that it is an ester of acrylic or methacrylic acid methyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethyl (meth) acrylate, glycidyl (meth ) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, tert-butyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide or (meth) acrylonitrile, and that they as σ, ß - In addition to acrylic acid and methacrylic acid, ethylenically unsaturated carboxylic acids also contain crotonic acid, maleic acid itaconic acid or their half esters.
3. Gießmasse nach Anspruch 1 , dadurch gekennzeichnet, daß die Teilchengrößenverteilung des Emulsionspolymerisats eng ist, wobei der Quotient aus der gewichtsmittleren Teilchengröße dw und der zahlenmittleren Teilchengröße dn einen Wert von kleiner 1 ,3 ergibt.3. Casting compound according to claim 1, characterized in that the particle size distribution of the emulsion polymer is narrow, the quotient of the weight-average particle size d w and the number-average particle size d n giving a value of less than 1.3.
4. Gießmasse nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß das Emulsionscopolymerisat eine Glastemperatur T im Bereich von -10 bis + 10 °C aufweist, daß seine minimale Filmbildetemperatur (MFT) zwischen 0 und 5 °C liegt, daß sein Säuregehalt zwischen 15 und 25 mol% beträgt.4. Casting compound according to one of claims 1 to 3, characterized in that the emulsion copolymer has a glass transition temperature T in the range from -10 to + 10 ° C, that its minimum film-forming temperature (MFT) is between 0 and 5 ° C is that its acidity is between 15 and 25 mol%.
5. Gießmasse nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß sie das Bindemittel in einer Menge von 3,0 bis 6,0 Gew.-% enthält.5. Casting compound according to one of claims 1 to 4, characterized in that it contains the binder in an amount of 3.0 to 6.0 wt .-%.
6. Gießmasse nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß sie zusätzlich Glycerin, Mono- oder Diethylenglykol oder Polyethylenglykol als Plastifiziermittel in einer Menge von 0 bis 2,0 Gew-%, bezogen auf das Gesamtgewicht der Gießmasse, enthält.6. Casting compound according to one of claims 1 to 5, characterized in that it additionally contains glycerol, mono- or diethylene glycol or polyethylene glycol as plasticizer in an amount of 0 to 2.0% by weight, based on the total weight of the casting compound.
7. Gießmasse nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß sie als keramisches Pulver Metalloxide oder -nichtoxide wie Karbide, Nitride, Boride und Sulfide von Lithium, Kalium Beryllium, Magnesium, Bor, Aluminium, Silizium, Kupfer, Kalzium, Strontium, Barium, Zink, Cadmium, Gallium, Indium, Titan, Zirkon, Wismut oder Mangan oder Mischungen von diesen.7. Casting compound according to one of claims 1 to 6, characterized in that it is a ceramic powder metal oxides or non-oxides such as carbides, nitrides, borides and sulfides of lithium, potassium beryllium, magnesium, boron, aluminum, silicon, copper, calcium, strontium , Barium, zinc, cadmium, gallium, indium, titanium, zircon, bismuth or manganese or mixtures of these.
8. Gießmasse nach Anspruch 7, dadurch gekennzeichnet, daß sie das keramische Pulver in einer Menge von 70 bis 85 Gew.-%, vorzugsweise von 75 bis 80 Gew.-%, enthält, bezogen jeweils auf das Gesamtgewicht der Gießmasse.8. Casting compound according to claim 7, characterized in that it contains the ceramic powder in an amount of 70 to 85 wt .-%, preferably from 75 to 80 wt .-%, based in each case on the total weight of the casting compound.
9. Gießmasse nach einem der Ansprüche 1 bis 8, dadurch gekennzeichnet, daß sie als Dispersionsmedium im wesentlichen Wasser in einer Menge im Bereich von 15 bis 20 Gew.-%, bezogen auf das Gesamtgewicht der Gießmasse, enthält.9. Casting compound according to one of claims 1 to 8, characterized in that it essentially contains water as a dispersion medium in an amount in the range from 15 to 20% by weight, based on the total weight of the casting compound.
10. Verwendung einer Gießmasse nach einem der Ansprüche 1 bis 9 zur Herstellung von Grünfolien nach dem Gießverfahren und deren Weiterverarbeitung zu keramischen Formteilen. 10. Use of a casting compound according to one of claims 1 to 9 for the production of green foils by the casting process and their further processing into ceramic molded parts.
PCT/EP1993/002584 1992-10-06 1993-09-23 Aqueous casting compound for producing green ceramic films and ceramic mouldings produced therefrom WO1994007808A1 (en)

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0897196A1 (en) * 1997-08-13 1999-02-17 Siemens Aktiengesellschaft Method of manufacturing an insulating component for a high-temperature fuel-cell and high-temperature fuel-cell
WO2000043328A1 (en) * 1999-01-20 2000-07-27 Siemens Aktiengesellschaft Aqueous ceramic casting material, method for producing said casting material and use of the same
EP1090890A3 (en) * 1999-10-05 2002-01-02 Rohm And Haas Company Method for preparing ceramic compositions
WO2002018300A1 (en) * 2000-09-01 2002-03-07 Epcos Ag Ceramic slip and method for production of a ceramic film blank
CN1125794C (en) * 1999-02-05 2003-10-29 北京航空材料研究院 Process for synthesizing composite ceramic powder body
US6790907B2 (en) * 2000-06-29 2004-09-14 Murata Manufacturing Co. Ltd. Ceramic slurry composition and manufacturing method therefor
WO2004110954A1 (en) 2003-06-10 2004-12-23 Robert Bosch Gmbh Method for producing ceramic green films for ceramic components
CN1321090C (en) * 2004-04-09 2007-06-13 中国航空工业第一集团公司北京航空材料研究院 Enzymatic gel reacting synthetic method of composite ceramic powder
US7713896B2 (en) 2004-04-14 2010-05-11 Robert Bosch Gmbh Method for producing ceramic green compacts for ceramic components

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19940653A1 (en) 1999-08-26 2001-03-01 Franz Koppe Process for making a porcelain body
KR100587461B1 (en) * 2004-06-17 2006-06-09 전자부품연구원 Slurry composition for use in Green Sheet and Green Sheet made therefrom

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4329271A (en) * 1980-12-15 1982-05-11 Gte Products Corporation Flexible ceramic tape and method of making same
EP0237273A1 (en) * 1986-03-07 1987-09-16 BASF Aktiengesellschaft Ceramics
WO1988007505A1 (en) * 1987-04-01 1988-10-06 Ceramics Process Systems Polymerizable binder solution for low viscosity, highly loaded particulate slurries and methods for making green articles therefrom
US4836966A (en) * 1984-03-15 1989-06-06 Isoo Shimuzu Binder for ceramics
JPH01289804A (en) * 1988-05-17 1989-11-21 Mizutani Paint Kk Water-dispersed resin composition
JPH03150257A (en) * 1989-11-04 1991-06-26 Daiichi Seramo:Kk Composition for injection molding and sintered material obtained therefrom
EP0511429A1 (en) * 1989-11-04 1992-11-04 Dai-Ichi Ceramo Co., Limited Injection compacting composition for preparing sintered bodies

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4329271A (en) * 1980-12-15 1982-05-11 Gte Products Corporation Flexible ceramic tape and method of making same
US4836966A (en) * 1984-03-15 1989-06-06 Isoo Shimuzu Binder for ceramics
EP0237273A1 (en) * 1986-03-07 1987-09-16 BASF Aktiengesellschaft Ceramics
EP0428177A2 (en) * 1986-03-07 1991-05-22 BASF Aktiengesellschaft Ceramics
WO1988007505A1 (en) * 1987-04-01 1988-10-06 Ceramics Process Systems Polymerizable binder solution for low viscosity, highly loaded particulate slurries and methods for making green articles therefrom
JPH01289804A (en) * 1988-05-17 1989-11-21 Mizutani Paint Kk Water-dispersed resin composition
JPH03150257A (en) * 1989-11-04 1991-06-26 Daiichi Seramo:Kk Composition for injection molding and sintered material obtained therefrom
EP0511429A1 (en) * 1989-11-04 1992-11-04 Dai-Ichi Ceramo Co., Limited Injection compacting composition for preparing sintered bodies

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 9001, Derwent World Patents Index; AN 90-005252 *
PATENT ABSTRACTS OF JAPAN vol. 015, no. 373 (C - 0689) 19 September 1991 (1991-09-19) *
See also references of EP0663893A1 *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0897196A1 (en) * 1997-08-13 1999-02-17 Siemens Aktiengesellschaft Method of manufacturing an insulating component for a high-temperature fuel-cell and high-temperature fuel-cell
WO2000043328A1 (en) * 1999-01-20 2000-07-27 Siemens Aktiengesellschaft Aqueous ceramic casting material, method for producing said casting material and use of the same
US6521686B1 (en) 1999-01-20 2003-02-18 Siemens Aktiengesellschaft Aqueous ceramic casting material, method for producing said casting material and use of the same
CN1125794C (en) * 1999-02-05 2003-10-29 北京航空材料研究院 Process for synthesizing composite ceramic powder body
EP1090890A3 (en) * 1999-10-05 2002-01-02 Rohm And Haas Company Method for preparing ceramic compositions
US6790907B2 (en) * 2000-06-29 2004-09-14 Murata Manufacturing Co. Ltd. Ceramic slurry composition and manufacturing method therefor
WO2002018300A1 (en) * 2000-09-01 2002-03-07 Epcos Ag Ceramic slip and method for production of a ceramic film blank
WO2004110954A1 (en) 2003-06-10 2004-12-23 Robert Bosch Gmbh Method for producing ceramic green films for ceramic components
CN1321090C (en) * 2004-04-09 2007-06-13 中国航空工业第一集团公司北京航空材料研究院 Enzymatic gel reacting synthetic method of composite ceramic powder
US7713896B2 (en) 2004-04-14 2010-05-11 Robert Bosch Gmbh Method for producing ceramic green compacts for ceramic components

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