Claims
- 1. A process of casting a metal comprising:
- A. fabricating a molding assembly by applying an adhesive paste to at least two foundry shapes, wherein said shapes are made of foundry aggregate held together with a foundry binder, so as to bond said foundry shapes together as a molding assembly, wherein the adhesive paste comprises:
- I. a solventless Part I component comprising:
- A. a prepolymer having from 3-15 percent free isocyanate groups comprising the reaction product of a polyol and an aromatic polyisocyanate;
- B. an aliphatic polyisocyanate; and
- C. a thixotropic filler; and
- II. a solventless Part II component comprising a curative comprising:
- (1) a polyether polyol;
- (2) a diamine; and
- (3) a thixotropic filler, such that the amount of filler in the Part I and Part II is sufficient to increase the viscosity of the Part I and the Part II from 4,000 to 40,000 cps at 25.degree. C.
- B. pouring said metal while, in the liquid state, into or around said molding assembly;
- C. allowing said metal to cool and solidify so as to provide a formed metal article; and
- D. separating said metal article from said molding assembly.
- 2. The process of claim 1 wherein the desired weight ratio of the prepolymer of the Part I to the curative of the Part II is about 4:1.
- 3. The process of claim 2 wherein the amount of the filler in the Part I component is from 4 to 11 weight percent, said weight percent based upon the total weight of the Part I component, and the amount of filler in the Part II component is from 15 to 30 weight percent, said weight percent based upon the total weight of the Part II component.
- 4. The process of claim 3 wherein the prepolymer of adhesive of the Part I component is prepared by the reaction of a polyol having a molecular weight of 1000 to 3500 which is reacted with an organic polyisocyanate such that it contains from 7 to 10 percent free isocyanate.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of Ser. No. 08/040,171 filed on Mar. 30, 1993 and now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4552934 |
Rabito et al. |
Nov 1985 |
|
4724892 |
Schneider et al. |
Feb 1988 |
|
5143996 |
Chung et al. |
Sep 1992 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
40171 |
Mar 1993 |
|