Coating composition, comprising organic ester compounds and particulate, amorphous silicon dioxide, for use in the foundry industry

A coating composition comprising

• (a) water,
• (b) one or more organic compounds of the formula (I)
• where R1 and R2
• are each monovalent groups which independently of one another each contain 1 to 26 C atoms, where R1 is attached via one of the C atoms contained in the group or via an O atom contained in the group, and where R2 is attached via a C atom contained in the group,
• or
• are linked to one another to form a ring structure such that the ring structure comprises a total of 4 to 7 ring atoms and the groups R1 and R2 comprise a total of 2 to 26 C atoms, where R1 is attached via one of the C atoms contained in the group or via an O atom contained in the group, and where R2 is attached via a C atom contained in the group,
• and
• (c) particulate, amorphous silicon dioxide, and
• (d) one or more further refractories,
• for producing a coating on a mold or a core, for use in the foundry.

The method of particulate, amorphous silicon dioxide in a coating composition comprising

• (a) water,
• (b) one or more organic compounds of the formula (I)
• where R1 and R2
• are each monovalent groups which independently of one another each contain 1 to 26 C atoms, where R1 is attached via one of the C atoms contained in the group or via an O atom contained in the group, and where R2 is attached via a C atom contained in the group,
• or
• are linked to one another to form a ring structure such that the ring structure comprises a total of 4 to 7 ring atoms and the groups R1 and R2 comprise a total of 2 to 26 C atoms, where R1 is attached via one of the C atoms contained in the group or via an O atom contained in the group, and where R2 is attached via a C atom contained in the group,
• and
• (d) one or more further refractories,
• for increasing the storage stability of the coating composition
• and/or
• as a means for reducing the detrimental effect, due to the coating with the water-containing refractory coating, on the flexural strength of a waterglass-bound core or waterglass-bound mold.