Polyurethane casting compound for producing wear protection coatings in casting house applications

Patent metadata

Field	Value
Publication number	US-9738749-B2
Application number	US-201314430050-A
Country	US
Kind code	B2
Filing date	Oct 1, 2013
Priority date	Oct 1, 2012
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

The present invention relates to multi-component compositions including an isocyanate component and an amine component, wherein the isocyanate component includes a prepolymer, obtainable from toluene isocyanate and a polytetramethylene polyol, and the amine component includes a dialkylthio aryl diamine and possibly a polytetramethylene oxide polyamine. Corresponding compositions can be advantageously used as flowable or spreadable resin systems for producing surface protection coatings in casting house applications and are characterized by a significantly improved resistance to abrasion in comparison with conventional casting resin systems based on hexamethylene diisocyanate and dimethyl thiotoluene diamine.

First claim

The invention claimed is:

1. A model and/or core box for casting house applications, the model and/or core box having a coating made of a cured composition obtainable from a multi-component composition, the multi-component composition comprising:
an isocyanate component and an amine component, wherein
the isocyanate component comprises a prepolymer, obtainable from toluene diisocyanate and a polytetramethylene polyol, and
the amine component comprises a dialkylthio aryl diamine.

2. The model and/or core box according to claim 1 , wherein the model and/or core box is a model for producing sand molds or a core box for producing sand cores.

3. The model and/or core box according to claim 1 , wherein the coating made of the cured multi-component composition has a thickness in the range of about 6 to 15 mm.

4. The model and/or core box according to claim 1 , wherein the composition essentially consists of the isocyanate and amine components.

5. The model and/or core box according to claim 1 , wherein the polytetramethylene polyol has a calculated molecular weight (Mw) in the range of 500 to 1500.

6. The model and/or core box according to claim 1 , wherein the dialkylthio aryl diamine is present in the form of dimethyl thiotoluene diamine.

7. The model and/or core box according to claim 1 , wherein the amine component additionally contains a polytetramethylene oxide polyamine in the form of a diamine.

8. The model and/or core box according to claim 1 , wherein the polytetramethylene oxide part of the polytetramethylene oxide polyamine has a calculated molecular weight (Mw) in the range of 500 to 1500.

9. The model and/or core box according to claim 1 , wherein the amine component additionally has a non-saponifiable plasticizer.

10. The model and/or core box according to claim 9 , wherein the amine component has a dialkylthio aryl diamine content in the range of about 30 to 70 wt. %, a polytetramethylene oxide polyamine content in the range of about 5 to 25 wt. %, and a non-saponifiable plasticizer content in the range of 20 to 60 wt. %.

11. The model and/or core box according to claim 9 , wherein the non-saponifiable plasticizer is in the form of an alkyl sulfonate.

12. The model and/or core box according to claim 1 , wherein the isocyanate and amine components are present in a weight ratio in the range of about 4:1 to 2:1.

13. The model and/or core box according to claim 1 , further comprises a casting resin or surface resin for casting house model making.

14. The model and/or core box according to claim 1 , wherein the prepolymer has an isocyanate content in the range of 7 to 10%.

15. The model and/or core box according to claim 1 , wherein the dialkylthio aryl diamine is a dialkyl thiotoluene diamine.

16. The model and/or core box according to claim 1 , wherein the amine component further comprises a polytetramethylene oxide polyamine.

17. A method for producing models and/or core boxes for casting house applications, the method comprising:
mixing a multi-component composition,
applying or casting the multi-component composition onto a molded part, and
curing the multi-component composition that was applied or casted onto the molded part; wherein the multi-component composition comprises:
an isocyanate component and an amine component, wherein
the isocyanate component comprises a prepolymer, obtainable from toluene diisocyanate and a polytetramethylene polyol, and
the amine component comprises a dialkylthio aryl diamine.

18. The method according to claim 17 , wherein the dialkylthio aryl diamine is a dialkyl thiotoluene diamine.

19. The method according to claim 17 , wherein the amine component further comprises a polytetramethylene oxide polyamine.

20. The method according to claim 17 , wherein applying or casting the multi-component composition onto a molded part comprises casting the multi-component composition into a cavity that is formed by the molded part and a container or carrier that surrounds the molded part on a side that has a shape to be reproduced.

Assignees

• Sika Tech Ag

Inventors

• DÜRNAY Wolfgang
• Gneiting Florian

Classifications

• B22C3/00 Primary

  Selection of compositions for coating the surfaces of moulds, cores, or patterns · CPC title

• C08G18/7621 Primary

  being toluene diisocyanate including isomer mixtures · CPC title

• B22C9/00

  Moulds or cores (uniquely adapted to particular casting processes B22D); Moulding processes · CPC title

• B22C21/00

  Flasks; Accessories therefor (stripping plates B22C17/06) · CPC title

• B22C1/2273

  Polyurethanes; Polyisocyanates · CPC title