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US 2003/0141031 A1Published application
Processes for preparing patterns for use in metal castings
AssigneeStyroChem Delaware, Inc.
InventorFred Sonnenberg
Life of this patent
Estimating the term…
Abstract
The present invention is directed to processes for forming styrenic polymers, and their related end uses. In particular, the present invention is directed to processes for preparing patterns for use in metal castings.
Claims15
A process for preparing a pattern for use in making metal castings which have significantly less residual carbon on the surface of the metal casting comprising:
- (a) adding an amount, effective for the purpose, of a combination of a bromine-attached aliphatic or aromatic flame retardant, and optionally, dicumyl peroxide to a suspension of vinyl aromatic polymer particles having a molecular weight of about 150,000 to 350,000 and having a bead size between 100 and 600 microns in diameter;
- and
- (b) adding a suitable blowing agent to the beads and heating to impregnate the beads, wherein said surface is selected from the group consisting of aluminum, brass, bronze, ductile iron, modular iron, grey iron, magnesium and steel.
A process for preparing a pattern for use in making metal castings which have significantly less residual carbon on the surface of the metal casting comprising:
- (a) adding an amount, effective for the purpose, of a combination of (1) a flame retardant selected from the group consisting of hexabromocyclododecane and tetrabromocyclooctane (2) dicumyl peroxide to a suspension of a polystyrene having a molecular weight of about 150,000 to 350,000 and having a bead size between 100 and 600 microns in diameter;
- and
- (b) adding a suitable blowing agent to the beads and heating to impregnate the beads, wherein said surface is selected from the group consisting of aluminum, brass, bronze, ductile iron, modular iron, grey iron, magnesium and steel.
Dependencies are inferred from the claim text.