EP0150745B1 - Binder composition for moulding - Google Patents

Binder composition for moulding Download PDF

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Publication number
EP0150745B1
EP0150745B1 EP85100275A EP85100275A EP0150745B1 EP 0150745 B1 EP0150745 B1 EP 0150745B1 EP 85100275 A EP85100275 A EP 85100275A EP 85100275 A EP85100275 A EP 85100275A EP 0150745 B1 EP0150745 B1 EP 0150745B1
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EP
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Prior art keywords
binder
sand
sodium silicate
added
hygroscopic
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EP85100275A
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German (de)
French (fr)
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EP0150745A2 (en
EP0150745A3 (en
Inventor
Thomas A. Cobett
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Bi-Tec Gesellschaft fur Bindemittel-Technolo GmbH
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Bi-Tec Gesellschaft fur Bindemittel-Technologie GmbH
Bi-Vt Bindemittel-Verfahrens-Technik fur Giessereien GmbH
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Application filed by Bi-Tec Gesellschaft fur Bindemittel-Technologie GmbH, Bi-Vt Bindemittel-Verfahrens-Technik fur Giessereien GmbH filed Critical Bi-Tec Gesellschaft fur Bindemittel-Technologie GmbH
Priority to AT85100275T priority Critical patent/ATE61258T1/en
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
    • B22C1/186—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents contaming ammonium or metal silicates, silica sols
    • B22C1/188—Alkali metal silicates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
    • B22C1/167—Mixtures of inorganic and organic binding agents

Definitions

  • the invention relates to a binder mixture for solidifying the molding sand for foundry purposes, according to the first part of patent claim 1.
  • Patent document GB-A-1087767 discloses a mixture of aqueous sodium silicate solution with dry hygroscopic glucose, calcium carbonate and iron oxide.
  • polysaccharides which contain an anhydro-glucose unit, to the heat escaping during the casting process.
  • suitable polysaccharides for this beet or. Cane sugar or dextrin (broken down starch) are called, which are supposed to form raw materials for the in situ production of hygroscopical glucose.
  • a known binder composition (DE-A-2641249) of the type mentioned at the outset is intended to address the problem of creating sodium silicate binder compositions for the production of casting molds and cores which remain stable for three months or more when stored. It is recognized that when reducing cane sugar is used as a decay additive, strong hygroscopic behavior arises, which is disadvantageous for molds and cores in a moist atmosphere. To remedy this, an aqueous solution of a sodium silicate which contains a starch hydrolyzate with a dextrose equivalent of less than five is proposed as the binder composition. Catalytic hydrogenation with hydrogen is recommended as the preferred method for obtaining starch hydrolysates with such a low dextrose equivalent.
  • Hydrogenated starch hydrolyzate syrups with a dextrose equivalent of at most 0.01 are used as practical exemplary embodiments.
  • a chemical hardening agent namely esters of a polyhydric alcohol, is specified. So it becomes a binder consisting of a few Components taught, namely from an aqueous alkali silicate solution and a liquid starch hydrolyzate syrup with a dextrose equivalent, which should be dimensioned as low as possible.
  • a polyhydric alcohol, a non-hygroscopic starch hydrolyzate with a reducing power of 6-15%, non-hygroscopic starch, iron oxide and a lubricant are proposed as further additives in a binder mixture with the features mentioned in the preamble of claim 1.
  • the non-hygroscopic starch and the iron oxide being added in powder form and in an amount of 0.25 to 1% by weight of sand.
  • the non-hygroscopic starch and the iron oxide are added to the sand when this binder mixture is used according to the invention for the production of foundry molds before the addition of the sodium silicate and the modified carbohydrate.
  • the actual binder burns at about 200 ° C during the casting process.
  • the casting molds made from sand and the binder mixture according to the invention are absolutely resistant to the effects of moisture.
  • the sodium silicate and the modified carbohydrate are main components and have the following characteristic properties of this binder system: It is characterized by a low viscosity and a moisture resistance due to these components. This system also exhibits complete chemical reactions with the gelling reagents and increased reaction rates over the unmodified ones Sodium silicate binder systems. Another difference compared to the unmodified sodium silicate binder systems lies in the lower freezing point and an increased elasticity of the bonds between the grains of sand after the gelling process. This system is also characterized by a reduced catalyst consumption.
  • the modified carbohydrate is a non-hygroscopic starch hydrolyzate with a reducing power of 6-15%, which can also be added as a powder with -100 mesh to -200 mesh.
  • a lubricant for example in powder form, is added in an amount of 1 to 2% by weight of the amount of sand or else as an oil in an amount of 0.10-0.25% by weight of the amount of sand becomes.
  • the flowability of the sand mixture is improved by the addition of this lubricant.
  • the non-hygroscopic starch, the metal oxide and the lubricant bring about an increase in the tensile strength of the binder of almost 25% in the binder system according to the invention. This characteristic property can be improved by using CO2 or a chemical catalyst. Due to rapid drying, the mixture according to the invention shows high strength within a short time. It is also noteworthy that the set sand forms to achieve a Dehydration does not need to be oven dried or burned. This advantage is reflected in a large saving in energy and labor and thus in manufacturing costs.
  • ester compounds from a polyhydric alcohol and organic acids are used as catalysts.
  • the following acids have proven to be particularly suitable: acetic acid, carbonic acid, citric acid, glutaric acid and succinic acid. These different esters are mixed in different amounts and combinations.
  • the type and amount of the catalyst influence the production time of the molds, which can range from 2 minutes to several hours.
  • any sand customary in foundry technology such as e.g. Zircon, chromite, olivine, and silicate can be used.
  • the proportion of molding sand is approximately 96.5%, that of sodium silicate solution 3%, that of starch and metal oxide 0.5% and that of the lubricant up to 0.25%. If a catalyst is used, it is added in an amount of approximately 0.3%.
  • the ratio of the preparation time to the curing time is 1: 2.
  • the casting molds produced with the binder mixture according to the invention and the method according to the invention have a long shelf life, which amounts to approximately 30 days, with no special requirements being placed on the storage of the finished foundry molds.
  • the binder burns at about 200 ° C during the casting process, whereby the sand structure becomes loose and crumbles.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Mold Materials And Core Materials (AREA)
  • Reinforced Plastic Materials (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

The binder composition for consolidating the moulding sand for foundry purposes consists of an alkali metal silicate, preferably sodium silicate, a polyhydric alcohol and further additives, modified carbohydrates, non-hygroscopic starch, a metal oxide and a filler being envisaged as additives.

Description

Die Erfindung betrifft ein Bindemittelgemisch zur Verfestigung des Formsandes für Gießereizwecke, entsprechend dem ersten Teil des Patentanspruchs 1.The invention relates to a binder mixture for solidifying the molding sand for foundry purposes, according to the first part of patent claim 1.

Bei der Verwendung allgemein üblicher Bindemittelgemische ergeben sich teilweise folgende Schwierigkeiten: Einige Komponenten der herkömmlichen Gemische haben nicht nur einen starken, unangenehmen Geruch, sondern sind auch giftig und daher gesundheitsschädlich. Sie belasten die Umwelt und ihre Abfallprodukte müssen mit einem hohen finanziellen Aufwand beseitigt werden.When using generally customary binder mixtures, the following difficulties arise in some cases: Some components of the conventional mixtures not only have a strong, unpleasant smell, but are also toxic and therefore harmful to health. They pollute the environment and their waste products have to be disposed of at great expense.

Ein anderes Problem besteht darin, daß sich die mit einigen Bindemittelgemischen hergestellten Gießformen nach der Abkühlphase nur unter großen Schwierigkeiten von dem ausgehärteten Modell entfernen lassen. Bei komplizierteren Formgebungen ist es häufig notwendig, die Gießform in sorgfältiger Handarbeit zu entfernen. Dabei besteht die Gefahr der Beschädigung der Oberfläche des Modells. Dazu kommt, daß dieser zusätzliche Aufwand große Zusatzkosten verursacht, die sich unweigerlich in einer Verteuerung der Gießformen niederschlagen. Es hat sich außerdem gezeigt, daß die mit den seitherigen Bindemittelgemischen gegossenen Formen teilweis hygroskopische Eigenschaften zeigen und daher ihre Formbeständigkeit nur von kurzer Dauer ist. Dieses Phänomen erschwert eine gewisse Vorratshaltung und damit eine rationelle Arbeitsweise.Another problem is that the molds made with some binder mixtures are difficult to remove from the cured model after the cooling phase. With more complicated shapes, it is often necessary to remove the casting mold by hand. There is a risk of damaging the surface of the model. In addition, this additional effort causes great additional costs, which inevitably result in an increase in the cost of the casting molds. It has also been found that the molds cast with the binder mixtures since then have partly hygroscopic properties and therefore their dimensional stability is short-lived. This phenomenon complicates a certain stockpiling and therefore a rational way of working.

Aus dem Patentdokument EP-A-0029196 ist ein Bindemittel zur Herstellung von Formkörpern bekannt, das auf wässriger Kalimetall-Silikat-Lösung, insbesondere Natrium-Silikat-Lösung basiert. Als Verbesserung wird vorgeschlagen, reduktiv aminierte Mono-, Di- oder Oligosaccaride hinzuzugeben. Hierdurch soll die außerordentlich ausgeprägte Hygroskopi zität, durch welche sich die genannten Saccaride auszeichnen, stark vermindert werden.From the patent document EP-A-0029196 a binder for the production of moldings is known which is based on aqueous potassium metal silicate solution, in particular sodium silicate solution. As an improvement, it is proposed to add reductively aminated mono-, di- or oligosaccharides. This is said to be the extremely pronounced hygroscopia tity, by which the mentioned saccharides are characterized, are greatly reduced.

In dem Patentdokument GB-A-1087767 wird eine Mischung aus wässriger Natrium-Silikat-Lösung mit trockener hygroskopischer Glukose, Kalziumcarbonat und Eisenoxid offenbart. Um die Glukose an Ort und Stelle produzieren zu können, wird vorgeschlagen, Polysaccaride, die eine Anhydro-Glukoseeinheit enthalten, der beim Gießprozeß entweichenden Hitze auszusetzen. Als geeignete Polysaccaride hierfür werden Rüben-bzw. Rohrzucker oder Dextrin (zerlegte Stärke) genannt, die Ausgangsstoffe für die in situ-Produktion der hygroskokpischen Glukose bilden sollen.Patent document GB-A-1087767 discloses a mixture of aqueous sodium silicate solution with dry hygroscopic glucose, calcium carbonate and iron oxide. In order to be able to produce the glucose on the spot, it is proposed to expose polysaccharides, which contain an anhydro-glucose unit, to the heat escaping during the casting process. As suitable polysaccharides for this beet or. Cane sugar or dextrin (broken down starch) are called, which are supposed to form raw materials for the in situ production of hygroscopical glucose.

Mit einer bekannten Bindemittelzusammensetzung (DE-A-2641249) etwa der eingangs genannten Art soll das Problem angegangen werden, Natrium-Silikat-Bindemittelzusammensetzungen zur Herstellung von Gießformen und -kernen zu schaffen, die bei der Aufbewahrung für drei Monate oder mehr beständig bleiben. Es wird erkannt, daß bei Verwendung von reduzierendem Rohrzucker als Zerfallzusatz starkhygroskopisches Verhalten entsteht, was bei feuchter Atmosphäre für Formen und Kerne nachteilig ist. Zur Abhilfe wird als Bindemittelzusammensetzung eine wässrige Lösung eines NatriumSilikats vorgeschlagen, das ein Stärkehydrolysat mit einem Dextrose-Äquivalent kleiner als fünf enthält. Als bevorzugte Methode zur Gewinnung von Stärkehydrolysaten mit derart niedrigem Dextrose-Äquivalent wird eine katalytische Hydrierung mit Wasserstoff empfohlen. Als praktische Ausführungsbeispiele werden hydrierte Stärkehydrolysat-Sirupe mit einem Dextrose-Äquivalent von höchstens 0,01 verwendet. Schließlich wird noch die Einarbeitung eines chemischen Härtemittels, nämlich Ester eines mehrwertigen Alkohols angegeben. Es wird also ein Bindemittel bestehend aus wenigen Komponenten gelehrt, nämlich aus einer wässrigen Alkali-Silikat-Lösung und einem flüssigen Stärkehydrolysat-Sirup mit einem Dextrose-Äquivalent, das so niedrig wie möglich zu dimensionieren ist.A known binder composition (DE-A-2641249) of the type mentioned at the outset is intended to address the problem of creating sodium silicate binder compositions for the production of casting molds and cores which remain stable for three months or more when stored. It is recognized that when reducing cane sugar is used as a decay additive, strong hygroscopic behavior arises, which is disadvantageous for molds and cores in a moist atmosphere. To remedy this, an aqueous solution of a sodium silicate which contains a starch hydrolyzate with a dextrose equivalent of less than five is proposed as the binder composition. Catalytic hydrogenation with hydrogen is recommended as the preferred method for obtaining starch hydrolysates with such a low dextrose equivalent. Hydrogenated starch hydrolyzate syrups with a dextrose equivalent of at most 0.01 are used as practical exemplary embodiments. Finally, the incorporation of a chemical hardening agent, namely esters of a polyhydric alcohol, is specified. So it becomes a binder consisting of a few Components taught, namely from an aqueous alkali silicate solution and a liquid starch hydrolyzate syrup with a dextrose equivalent, which should be dimensioned as low as possible.

Zur Lösung der beim Stand der Technik auftretenden Probleme werden bei einem Bindemittelgemisch mit den im Oberbegriff des Patentanspruchs 1 genannten Merkmalen als weitere Additive ein mehrwertiger Alkohol, ein nichthygroskopisches Stärkehydrolysat mit einer Reduktionskraft von 6 - 15 %, nichthygroskokpische Stärke, Eisenoxid und ein Schmiermittel vorgeschlagen, wobei die nichthygroskopische Stärke und das Eisenoxid in Pulverform und in einer Menge von 0,25 bis 1 Gew.-% Sandmenge zugesetzt werden. Durch den Zusatz des Eisenoxids wird eine gewisse Fließfähigkeit und das Durchhärten erreicht. Der Zusatz der nichthygroskopischen Stärke und des Eisenoxids zum Sand erfolgt bei einer erfindungsgemäßen Verwendung dieses Bindemittelgemisches zur Herstellung von Gießereiformen vor der Zugabe des NatriumSilikats und des modifizierten Kohlehydrats.To solve the problems occurring in the prior art, a polyhydric alcohol, a non-hygroscopic starch hydrolyzate with a reducing power of 6-15%, non-hygroscopic starch, iron oxide and a lubricant are proposed as further additives in a binder mixture with the features mentioned in the preamble of claim 1. the non-hygroscopic starch and the iron oxide being added in powder form and in an amount of 0.25 to 1% by weight of sand. By adding the iron oxide, a certain fluidity and hardening is achieved. The non-hygroscopic starch and the iron oxide are added to the sand when this binder mixture is used according to the invention for the production of foundry molds before the addition of the sodium silicate and the modified carbohydrate.

Dabei hat es sich als vorteilhaft erwiesen, daß im Natriumsilikat ein Verhältnis von

        Na₂O : SiO₂

= 1 2 bis 1 : 3 besteht. Diese Komponenten des Bindemittelgemisches sind geruchlos und völlig ungefährlich, ja sogar eßbar. Der Umgang und das Arbeiten mit den Sandgemischen, die diese Komponenten enthalten, erfordern keinerlei Schutzmaßnahmen; die Beseitigung der Abfallprodukte ist völlig problemlos.It has proven to be advantageous that a ratio of

Na₂O: SiO₂

= 1 2 to 1: 3. These components of the binder mixture are odorless and completely harmless, even edible. Handling and working with the sand mixtures containing these components do not require any protective measures; the disposal of the waste products is completely problem-free.

Der eigentliche Binder verbrennt beim Gießprozeß bei ungefähr 200°C. Dabei brechen die durch ihn hervorgerufenen Bindungen zwischen den Sandkörnern zusammen, mit der Folge, daß die Sandform zerfällt und aus komplizierten Raumformen herausbröselt. Dadurch erübrigt sich ein vorher notwendiger, zusätzlicher Arbeitsvorgang, bei dem die Gießform mit viel Mühe von dem gegossenen Modell entfernt werden mußte. Auf der anderen Seite sind die aus Sand und dem erfindungsgemäßen Bindemittelgemisch hergestellten Gießformen gegen Feuchtigkeitseinflüsse absolut beständig.The actual binder burns at about 200 ° C during the casting process. The bonds he creates between the grains of sand break down, with the result that the sand mold disintegrates and crumbles out of complicated spatial shapes. This eliminates the need for an additional work step previously required, in which the casting mold had to be removed from the cast model with great difficulty. On the other hand, the casting molds made from sand and the binder mixture according to the invention are absolutely resistant to the effects of moisture.

Das Natriumsilikat und das modifizierte Kohlehydrat sind Hauptkomponenten und bedingen folgende charakteristische Eigenschaften dieses Bindersystems: Es zeichnet sich durch eine geringe Viskosität und eine durch diese Komponenten bedingte Feuchtigkeitsbeständigkeit aus. Außerdem weist dieses System vollständige chemische Reaktionen mit den Gelierreagenzien und erhöhte Reaktionsraten gegenüber den nichtmodifizierten Natriumsilikat-Bindersystemen auf. Ein weiterer Unterschied gegenüber den nichtmodifizierten Natriumsilikat-Bindersystemen liegt in dem tieferen Gefrierpunkt und einer erhöhten Elastizität der Bindungen zwischen den Sandkörnern nach dem Geliervorgang. Weiterhin zeichnet sich dieses System durch einen reduzierten Katalysatorverbrauch aus.The sodium silicate and the modified carbohydrate are main components and have the following characteristic properties of this binder system: It is characterized by a low viscosity and a moisture resistance due to these components. This system also exhibits complete chemical reactions with the gelling reagents and increased reaction rates over the unmodified ones Sodium silicate binder systems. Another difference compared to the unmodified sodium silicate binder systems lies in the lower freezing point and an increased elasticity of the bonds between the grains of sand after the gelling process. This system is also characterized by a reduced catalyst consumption.

Es liegt im Rahmen der Erfindung, daß das modifizierte Kohlehydrat ein nichthygroskopisches Stärkehydrolysat mit einer Reduktionskraft 6 - 15 % ist, das auch als Pulver mit -100 mesh bis -200 mesh zugesetzt werden kann.It is within the scope of the invention that the modified carbohydrate is a non-hygroscopic starch hydrolyzate with a reducing power of 6-15%, which can also be added as a powder with -100 mesh to -200 mesh.

Es liegt weiterhin im Rahmen der Erfindung, daß als Füllstoff ein Schmiermittel, beispielsweise in Pulverform in einer Menge von 1 bis 2 Gew. % der Sandmenge oder aber als Öl in einer Menge von 0,10 - 0,25 Gew. % der Sandmenge zugesetzt wird. Durch die Zugabe dieses Schmiermittels wird die Fließfähigkeit der Sandmischung verbessert. Die nichthygroskopische Stärke, das Metalloxid sowie das Schmiermittel bewirken in dem erfindungsgemäßen Bindersystem eine Erhöhung der Zugfestigkeit des Binders von nahezu 25 %. Diese charakteristische Eigenschaft kann noch durch den Einsatz von CO₂ oder eines chemischen Katalysators verbessert werden. Die erfindungsgemäße Mischung zeigt, bedingt durch eine schnelle Trocknung, innerhalb kurzer Zeit eine hohe Festigkeit. Es ist auch bemerkens - wert, daß die abgebundenen Sandformen zur Erreichung einer Dehydrierung nicht im Ofen getrocknet oder gebrannt werden müssen. Dieser Vorteil schlägt sich in einer großen Ersparnis an Energie und Arbeitsaufwand und damit an Herstellungskosten nieder.It is also within the scope of the invention that a lubricant, for example in powder form, is added in an amount of 1 to 2% by weight of the amount of sand or else as an oil in an amount of 0.10-0.25% by weight of the amount of sand becomes. The flowability of the sand mixture is improved by the addition of this lubricant. The non-hygroscopic starch, the metal oxide and the lubricant bring about an increase in the tensile strength of the binder of almost 25% in the binder system according to the invention. This characteristic property can be improved by using CO₂ or a chemical catalyst. Due to rapid drying, the mixture according to the invention shows high strength within a short time. It is also noteworthy that the set sand forms to achieve a Dehydration does not need to be oven dried or burned. This advantage is reflected in a large saving in energy and labor and thus in manufacturing costs.

Es hat sich als besonders vorteilhaft erwiesen, daß als Katalysatoren Esterverbindungen, aus einem mehrwertigen Alkohol und organischen Säuren, eingesetzt werden. Folgende Säuren haben sich als besonders geeignet erwiesen: Essigsäure, CarbonSäure, Zitronensäure, Glutarsäure und Bernsteinsäure. Diese verschiedenen Ester werden in unterschiedlichen Mengen und Kombinationen gemischt. Art und Menge des Katalysators beeinflussen die Produktionszeit der Gießformen, die sich von 2 Minuten bis mehrere Stunden erstrecken kann.It has proven to be particularly advantageous that ester compounds from a polyhydric alcohol and organic acids are used as catalysts. The following acids have proven to be particularly suitable: acetic acid, carbonic acid, citric acid, glutaric acid and succinic acid. These different esters are mixed in different amounts and combinations. The type and amount of the catalyst influence the production time of the molds, which can range from 2 minutes to several hours.

Bei dem Verfahren zur Herstellung von Gießereiformen kann als Formsand jeder in der Gießereitechnik übliche Sand, wie z.B. Zirkon, Chromit, Olivin, und Silikat verwendet werden. Der Anteil des Formsandes beläuft sich ungefähr auf 96,5 %, der der Natriumsilikatlösung auf 3 %, der der Stärke und des Metalloxids auf 0,5 % und der des Schmiermittels bis zu 0,25 %. Wird ein Katalysator verwendet, so wird dieser in einer Menge von ungefähr 0,3 % zugesetzt. Das Verhältnis der Vorbereitungszeit zur Härtungszeit beträgt 1 : 2. Die mit dem erfindungsgemäßen Bindemittelgemisch und dem erfindungsgemäßen Verfahren hergestellten Gießformen haben eine lange Haltbarkeit, die sich ungefähr auf 30 Tage beläuft, wobei für die Aufbewahrung der fertigen Gießereiformen keine besonderen Anforderungen gestellt sind. Der Binder verbrennt beim Gießprozeß bei ungefähr 200°C, wobei das Sandgefüge lose wird und abbröselt.In the process for producing foundry molds, any sand customary in foundry technology, such as e.g. Zircon, chromite, olivine, and silicate can be used. The proportion of molding sand is approximately 96.5%, that of sodium silicate solution 3%, that of starch and metal oxide 0.5% and that of the lubricant up to 0.25%. If a catalyst is used, it is added in an amount of approximately 0.3%. The ratio of the preparation time to the curing time is 1: 2. The casting molds produced with the binder mixture according to the invention and the method according to the invention have a long shelf life, which amounts to approximately 30 days, with no special requirements being placed on the storage of the finished foundry molds. The binder burns at about 200 ° C during the casting process, whereby the sand structure becomes loose and crumbles.

Claims (8)

  1. Binder composition for hardening the moulding sand for moulding purposes, with a sodium silicate solution, characterised by the further additives:
    - polyhydric alcohol
    - a non-hygroscopic starch hydrolysis product with a reduction power of 5 to l5%
    - non-hygroscopic starch
    - iron oxide and
    - a lubricant,
    in which case the non-hygroscopic starch and the iron oxide are added in powdered form in a quantity of 0.25 to 2% by weight of the quantity of sand.
  2. Binder according to claim 1, characterized in that in the sodium silicate of the sodium silicate solution, the ratio of Na₂O to SiO₂ is from 1:2 to 1:3.
  3. Binder according to one of claims 1 to 2, characterised in that the non-hygroscopic starch hydrolysis product is added with a reduction power of 6 to 15% as powder with 0.149 mm (100 mesh) to 0.074 mm (200 mesh).
  4. Binder composition according to one of claims 1 to 3, characterised in that the lubricant is added in powdered form in a quantity of 1 to 2% by weight of the sand quantity.
  5. Binder composition according to claim 4, characterized in that the lubricant is added as oil in a quantity of 0.10 - O.25% by weight of the sand quantity.
  6. Binder according to one of claims 1 to 5, characterised in that the catalyst is an ester compound or carbonic acid.
  7. Binder according to claim 6, characterised in that the ester compound is an ester composed of a polyhydric alcohol and an organic acid.
  8. Use of the binder compound according to one of claims 1 to 7 for manufacturing mouldings, wherein the non-hygroscopic starch and the iron oxide are added to the sand before the addition of the sodium silicate solution and the non-hygroscopic starch hydrolysis product with a reduction power of 6 to 15%.
EP85100275A 1984-02-02 1985-01-12 Binder composition for moulding Expired - Lifetime EP0150745B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85100275T ATE61258T1 (en) 1984-02-02 1985-01-12 BINDER MIXTURE FOR CONSOLIDATION.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19843403583 DE3403583A1 (en) 1984-02-02 1984-02-02 Binder mix for consolidation
DE3403583 1984-02-02

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EP0150745A2 EP0150745A2 (en) 1985-08-07
EP0150745A3 EP0150745A3 (en) 1986-11-26
EP0150745B1 true EP0150745B1 (en) 1991-03-06

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EP (1) EP0150745B1 (en)
AT (1) ATE61258T1 (en)
DD (1) DD233959A5 (en)
DE (1) DE3403583A1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02165840A (en) * 1988-12-20 1990-06-26 M D Kasei Kk Molding material for sand mold for casting and production of sand mold for casting
HUE029506T2 (en) 2006-10-19 2017-02-28 Ask Chemicals Gmbh Moulding material mixture containing carbohydrates
DE102006061876A1 (en) * 2006-12-28 2008-07-03 Ashland-Südchemie-Kernfest GmbH Molding material mixture, useful for producing casting molds for metal processing, comprises a fireproof molding base material, a binder based on water glass, a particulate metal oxide, e.g. silicon dioxide and further a carbohydrate
CN105983645A (en) * 2015-12-31 2016-10-05 安徽创奇乐智能游乐设备有限公司 High-refractoriness and low-expansion molding sand for steel castings and preparation method of molding sand
WO2019027038A1 (en) * 2017-08-03 2019-02-07 旭有機材株式会社 Mold material, method for producing same, method for producing mold, and method for regenerating recovered refractory aggregate

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LU34695A1 (en) * 1955-10-14
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AU2236370A (en) * 1969-11-17 1972-05-18 Minerals, Binders, Clays (Proprietary) Limited Improvements in the co2 process for bonding, moulding and core sands in foundries
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DE2946500A1 (en) * 1979-11-17 1981-05-27 Henkel KGaA, 4000 Düsseldorf Binder based on alkali metal silicate solutions and their use

Also Published As

Publication number Publication date
DE3403583C2 (en) 1987-12-17
DE3403583A1 (en) 1985-08-08
DD233959A5 (en) 1986-03-19
EP0150745A2 (en) 1985-08-07
EP0150745A3 (en) 1986-11-26
ATE61258T1 (en) 1991-03-15

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