Product for reducing sand adhesions
AssigneeASK Chemicals GmbH
InventorsChristian Priebe, Matthias Peter
Life of this patent
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Abstract
Molding material mixes that contain a polyurethane binder based on phenolic resins of the benzyl ether type and polyisocyanates are characterized by the inclusion of a polybutadiene derivative. In one case, the polybutadiene derivative has epoxide groups and hydroxyl groups. In another case, the polybutadiene derivative has succinic acid anhydride groups. Molds, cores and risers are produced using these molding material mixes. Inclusion of the polybutadiene derivatives results in a reduction of sand adhesions in the molding process.
Claims19
A molding material mixture, comprising:
- a) a refractory molding base material,
- b) a binder comprising a phenolic resin of the benzyl ether type and a polyisocyanate or the conversion product thereof, respectively, and
- c) at least one of:
- a polybutadiene derivative comprising epoxide groups and hydroxyl groups, or a polybutadiene derivative comprising succinic anhydride groups.
A binder comprising the following components, which are present separately from one another:
- i) a polyol component comprising
- a phenolic resin of the benzyl ether type, and
- ii) an isocyanate component comprising
- a polyisocyanate comprising at least two isocyanate groups per molecule,
- a solvent for the isocyanate component, and
- a polybutadiene derivative having epoxide groups and hydroxyl groups or a polybutadiene derivative having succinic anhydride groups.
An improved molding material mixture, exhibiting reduced adhesion, the molding material mixture comprising polyisocyanate, phenolic resin of the benzyl ether type and refractory molding base material, wherein the improvement comprises:
- incorporating as a release agent in the molding material mixture, at least one of:
- a polybutadiene derivative having epoxide groups and hydroxyl groups;
- and
- a polybutadiene derivative having succinic anhydride groups, in particular as an internal release agent.
Dependencies are inferred from the claim text.