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AssigneeASK Chemicals GmbH
InventorsJens Müller, Diether Koch, Marcus Frohn, Jörg Korschgen
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The invention relates to a mould material mixture for producing casting moulds for metal processing, a process for producing casting moulds, casting moulds which can be obtained by the process and their use. The production of the casting moulds is carried out using a refractory base moulding material and a binder based on water glass. A proportion of a particulate metal oxide selected from the group consisting of silicon dioxide, aluminium oxide, titanium oxide and zinc oxide is added to the binder, with particular preference being given to using synthetic amorphous silicon dioxide. The mould material mixture contains a surface-active material as further significant constituent. The addition of the surface-active material enables the flowability of the mould material mixture to be improved, which makes it possible to produce casting moulds having a very complicated geometry.
1-24. (canceled)
A process for producing casting moulds for metal processing comprising at least the following steps:
The process according to claim 1, wherein the surfactant comprises a sulphate, or a sulphonate group or both.
The process according to claim 1, wherein the surfactant is selected from the group consisting of oleyl sulphate, stearyl sulphate, palmityl sulphate, myristyl sulphate, lauryl sulphate, decyl sulphate, octyl sulphate, 2-ethylhexyl sulphate, 2-ethyloctyl sulphate, 2-ethyldecyl sulphate, palmitoleyl sulphate, linolyl sulphate, lauryl sulphonate, 2-ethyldecyl sulphonate, palmityl sulphonate, stearyl sulphonate, 2-ethylstearyl sulphonate, linolyl sulphonate, hexyl phosphate, 2-ethylhexyl phosphate, capryl phosphate, lauryl phosphate, myristyl phosphate, palmityl phosphate, palmitoleyl phosphate, oleyl phosphate, stearyl phosphate, poly-(1,2-ethanediyl-)-phenol hydroxyphosphate, poly-(1,2-ethanediyl-)-stearyl phosphate, and poly-(1,2-ethanediyl-)-oleyl phosphate.
The process according to claim 1, wherein the surfactant is contained in the mould material mixture from 0.001 to 1% by weight relative to the weight of the refractory base moulding material.
The process according to claim 1, wherein the refractory base moulding material comprises a regenerated refractory base moulding material.
The process according to claim 1, wherein the mould material mixture further comprises at least one carbohydrate.
The process according to claim 1, wherein the mould material mixture further comprises at least one phosphorus-containing compound.
The process according to claim 1, wherein the particulate metal oxide is selected from the group consisting of precipitated silicic acid, pyrogenic silicic acid and mixtures thereof.
The process according to claim 1, wherein the water glass has an SiO2/M2O ratio in the range from 1.6 to 4.0, wherein M stands for sodium ions or potassium ions or both.
The process according to claim 1, wherein the mould material mixture comprises less than 20% by weight of the binder.
The process according to claim 1, wherein the binder comprises from 2 to 80% by weight particulate metal oxide, relative to the binder.
The process according to claim 1, wherein the refractory base moulding material comprises hollow microspheres.
The process according to claim 1, wherein the base moulding material contains at least a proportion of glass granules, glass beads, spherical ceramic moulding materials or mixtures thereof.
The process according to claim 1, wherein an oxidisable metal and an oxidant are added to the mould material mixture.
The process according to claim 1, wherein the mould material mixture comprises an inorganic additive that is solid at room temperature.
The process according to claim 1, wherein the mould material mixture comprises at least one silane or siloxane.
The process according to claim 1 wherein the mould material mixture is heated to a temperature in the range from 100 to 300° C.
The process according to claim 1 wherein heated air is blown into the moulded mould material mixture in order to cure it.
The process according to claim 1 wherein heating of the moulded mould material mixture is effected by the action of microwaves.
The process according to claim 1 wherein the refractory base moulding material comprises between 10 and 90% by weight regenerated refractory base moulding material obtained from reconditioning refractory base moulding material by at least a heat treatment or mechanical treatment or by both of a mould material mixture previously cured in the presence of a water glass binder and the surfactant increases the flowability of the mould material mixture.
The process according to claim 1 wherein mould material mixture is moulded and cured in a core shooting machine.
Dependencies are inferred from the claim text.