Binder based on phenolic resins of the benzyl ether type, containing free phenol and free hydroxybenzyl alcohols
AssigneeASK Chemicals GmbH
InventorsChristian Priebe, Philipp Schneider, Mark Stancliff, Brian Weaver
Life of this patent
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Abstract
The invention relates to a binder based on phenolic resins of the benzyl ether type and isocyanate compounds having at least two isocyanate groups, containing free phenol and free hydroxybenzyl alcohols in the polyol component. The invention further relates to mold material mixtures containing the binder and to cores, molds, or risers produced with the mold material mixtures and to the use thereof in metal casting.
Claims43
A binder for hardening mold material mixtures comprising:
- a polyol component, with the polyol component comprising a phenolic resin of the benzyl ether type;
- a isocyanate component comprised of one or more isocyanate compounds with at least 2 isocyanate groups per molecule;
- wherein the binder contains less than 3 weight percent of free phenol;
- wherein the binder has a saligenin (o-hydroxybenzyl alcohol) content in the range of 1 to 16 weight percent;
- wherein the binder has a hydroxybenzyl alcohol content in the range of 1 to 26 weight percent, in each case with reference to the weight of the phenolic resin of the benzyl ether type, and
- the binder is further characterized by at least one of the following:
- a) the binder contains free phenol and free hydroxybenzyl alcohol, and the weight ratio of free phenol to free hydroxybenzyl alcohol is 1:>1.2;
- and
- b) the binder contains free phenol and free saligenin, and the weight ratio of free phenol to free saligenin is 1:>1.1.
A mold material mixture comprising:
- a refractory mold base material;
- and
- a binder, wherein the binder comprises:
- a polyol component, with the polyol component being a phenolic resin of the benzyl ether type;
- and
- an isocyanate component comprised of one or more isocyanate compounds with at least 2 isocyanate groups per molecule;
- wherein, in each case with reference to the weight of the phenolic resin of the benzyl ether type:
- the binder contains less than 3 weight percent of free phenol;
- and
- the binder contains saligenin (o-hydroxybenzyl alcohol) in the range of 1 to 16 weight percent;
- and
- the binder contains hydroxybenzyl alcohol in the range of 1 to 26 weight percent;
- and
- the binder is further characterized by at least one of the following:
- a) the binder contains free phenol and free hydroxybenzyl alcohol, and the weight ratio of free phenol to free hydroxybenzyl alcohol is 1:>1.2;
- and
- b) the binder contains free phenol and free saligenin and the weight ratio of free phenol to free saligenin is 1:>1.1.
A kit for manufacturing a mold material mixture, comprising a binder and a refractory mold base material, wherein the kit comprises, separate from one another:
- an isocyanate component, comprising one or more isocyanate compounds with at least 2 isocyanate groups per molecule;
- and
- a phenolic resin component, comprising a phenolic resin of the benzyl ether type, and, wherein with reference to the weight of the phenolic resin of the benzyl ether type:
- the binder comprises free phenol at less than 3 weight percent;
- the binder comprises saligenin (o-hydroxybenzyl alcohol) in the range of 1 to 16 weight percent;
- and
- the binder comprises hydroxybenzyl alcohol in the range of 1 to 26 weight percent;
- wherein the binder is further characterized by at least one of the following features:
- a) the binder contains free phenol and free hydroxybenzyl alcohol, and the weight ratio of free phenol to free hydroxybenzyl alcohol amounts to 1:greater than 1.2;
- and
- b) the binder contains free phenol and free saligenin, and the weight ratio of free phenol to free saligenin amounts to 1:greater than 1.1.
Dependencies are inferred from the claim text.