Curable epoxy resin compositions and use in preparing formed, shaped, filled bodies

• US 4,806,576 A
• Filed: 09/11/1987
• Issued: 02/21/1989
• Est. Priority Date: 08/05/1982
• Status: Expired due to Term

• Current Assignee: Ashland Licensing and Intellectual Property Llc
• Original Assignee: Ashland Oil, Inc. (Ashland Global Holdings, Inc.)
• Inventors: Woodson, Wayne D.
• Primary Examiner(s): Jacobs, Lewis T.
• Application Number:
  US07/095,802
• Time in Patent Office: 529 Days
• Field of Search: 523/139, 523/466, 523/144, 523/145, 523/141, 252/523, 528/109, 528/405, 164/16, 264/83
• US Class Current: 523/139
• CPC Class Codes: B22C 1/2206 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: B22C 1/222 Polyacrylates
• CPC Class Codes: B22C 1/224 Furan polymers B22C1/2273 takes precedence
• CPC Class Codes: B22C 1/2246 Condensation polymers of aldehydes and ketones B22C1/224, B22C1/2273 take precedence
• CPC Class Codes: B22C 1/226 Polyepoxides
• CPC Class Codes: C08G 59/18 Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
• CPC Class Codes: C08G 59/40 characterised by the curing agents used
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 63/00 Compositions of epoxy resins; Compositions of derivatives of epoxy resins

Abstract

Curable epoxy resin compositions are described which comprise a mixture of an acid curable epoxy resin and a minor amount of an oxidizing agent capable of reacting with sulfur dioxide to form a catalyst for curing said epoxy resin. The curable epoxy resin composition may contain solid particulate materials. The procedures for curing such epoxy resins as well as methods for forming sand cores and molds also are described. Sand cores and molds produced in accordance with the method of the invention have sufficient strength and hardness after a few seconds of curing for normal foundry applications.

Claims

1. A curable binder composition comprising a mixture of

(a) a major amount of a free radical curable ethylenically unsaturated binder material,

(b) from 30 percent to 50 percent by weight of an epoxy resin, and

(c) an oxidizing agent capable of reacting with sulfur dioxide to form a catalyst for curing said resin mixture, said percent by weight of (b) being based upon the total weight of (a) and (b).

2. The composition of claim 1 wherein the oxidizing agent is a peroxide.

3. The composition of claim 1 wherein the epoxy resin is selected from the group consisting of (1) mixed aliphatic-aromatic epoxy resins derived from a bis(hydroxy-aromatic) alkane or a tetrakis(hydroxy-aromatic) akane with a halogen-substituted aliphatic epoxide, (2) novolac resins, and (3) aliphatic epoxy resins.

4. The composition of claim 3 wherein the ethylenically unsaturated binder material is a monomer.

5. The composition of claim 4 wherein the ethylenically unsaturated monomer is a monofunctional, diffunctional, trifunctional or tetrafunctional acrylate.

6. The compositions of claim 5 wherein the epoxy resin is a glycidyl ether of bisphenol A, B, F, G, or H.

7. The composition of claim 6 wherein the peroxide is methyl ethyl ketone peroxide, cumene hydroperoxide, paramenthane hydroperoxide, t-butyl hydroperoxide, diisopropyl benzene hydroperoxide, admixtures thereof or admixtures thereof with hydrogen peroxide.

8. A curable molding composition comprising a mixture of a major amount of a solid particulate material, and a minor amount of a binder composition comprising a mixture of

(a) a major amount of a free radical curable ethylenically unsaturated binder material,

(b) from 30 percent to 50 percent by weight of an epoxy resin, and

(c) an oxidizing agent capable of reacting with sulfur dioxide to form a catalyst for curing said resin mixture, said percent by weight of (b) being based upon the total weight of (a) and (b).

9. The composition of claim 8 wherein the oxidizing agent is a peroxide.

10. The molding composition of claim 9 wherein the epoxy resin is selected from the group consisting of (1) mixed aliphatic-aromatic epoxy resins derived from a bis(hydroxy-aromatic) alkane or a tetrakis(hydroxy-aromatic) alkane with a halogen-substituted aliphatic epoxide, (2) novolac resins, and (3) aliphatic epoxy resins.

11. The composition of claim 10 wherein the ethylenically unsaturated binder material is a monomer.

12. The composition of claim 11 wherein the ethylenically unsaturated monomer is a monofunctional, difunctional, trifunctional or tetrafunctional acrylate.

13. The composition of claim 12 wherein the epoxy resin is a glycidyl ether of bisphenol A, B, F, G, or H.

14. The composition of claim 13 wherein the peroxide is methyl ethyl ketone peroxide, cumene hydroperoxide, paramenthane hydroperoxide, t-butyl hydroperoxide, diisopropyl benzene hydroperoxide, admixtures thereof or admixtures thereof with hydrogen peroxide.

15. The composition of claim 14 wherein the solid particulate filler comprises inorganic abrasive particles.

16. The composition of claim 15 wherein the solid particulate filler comprises sand.

17. A method of curing binder compositions containing at least one epoxy resin which comprises the steps of

(a) preparing a mixture curable with gaseous sulfur dioxide comprising

(i) a major amount of a free radical curable ethylencially unsaturated binder material,

(ii) from 30 percent to 50 percent by weight an epoxy resin, and

(iii) an oxidizing agent capable of reacting with sulfur dioxide to form a catalyst for curing said resin mixture, said percent by weight of (a) (ii) being based upon the total weight of (a) (i) and (a) (ii), and

(b) contacting said mixture with gaseous sulfur dioxide.

18. The method of claim 17 wherein the oxidizing agent is a peroxide.

19. The method of claim 18 wherein the epoxy resin is selected from the group consisting of (1) mixed aliphatic-aromatic epoxy resins derived from a bis(hydroxy-aromatic) alkane or a tetrakis(hydroxy-aromatic) alkane with a halogen-substituted aliphatic epoxide, (2) novolac resins, and (3) aliphatic epoxy resins.

20. The method of claim 19 wherein the ethylenically unsaturated binder material is a monomer.

21. The composition of claim 20 wherein the ethylenically unsaturated monomer is a monofunctional, difunctional, trifunctional or tetrafunctional acrylate.

22. The method of claim 21 wherein the epoxy resin is a glycidyl ether of bisphenol A, B, F, G, or H.

23. The method of claim 22 wherein said peroxide is methyl ethyl ketone peroxide, cumene hydroperoxide, paramenthane hydroperoxide, t-butyl hydroperoxide, diisopropyl benzene hydroperoxide, admixtures thereof or admixtures thereof with hydrogen peroxide.

24. The method of claim 20 wherein the mixture is contacted with sulfur dioxide for a period of from a fraction of a second to about five minutes at a temperature of from ambient temperature to about 150°

C.

25. A method of forming foundry'"'"'s shapes which comprises the steps of

(a) mixing a major amount of solid particulate material with a minor amount of a binder composition comprising a mixture of

(i) a major amount of a free radical curable ethylenically unsaturated binder material,

(ii) from 30 percent to 50 percent by weight of an epoxy resin, said percent by weight of (a) (ii) being based upon the total weight of (a) (i) and (a) (ii), and

(iii) an oxidizing agent capable of reacting with sulfur dioxide to form a catalyst for curing said mixture,

(b) forming said mixture into the desired shape, and

(c) contacting said formed mixture with sulfur dioxide for a period of from a fraction of a second to about five minutes at a temperature of from room temperature to about 150 degrees C. to effect resin cure.

26. The method of claim 25 wherein the oxidizing agent is a peroxide.

27. The method of claim 26 wherein the epoxy resin is selected from the group consisting of (1) mixed aliphatic-aromatic epoxy resins derived fromm a bis(hydroxy-aromatic) alkane or a tetrakis(hydroxy-aromatic) alkane with a halogen-substituted aliphatic epoxide, (2) novolac resins, and (3) aliphatic epoxy resins.

28. The method of claim 27 wherein the ethylenically unsaturated binder material is a monomer.

29. The method of claim 28 wherein the ethylenically unsaturated monomer is a monofunctional, difunctional, triflunctional or tetrafunctional acrylate.

30. The method of claim 29 wherein the epoxy resin is a glycidyl ether of bisphenol A, B, F, G, or H.

31. The method of claim 30 wherein the peroxide is methyl ethyl ketone peroxide, cumene hydroperoxide, paramenthane hydroperoxide, t-butyl hydroperoxide, diisopropyl benzene hydroperoxide, admixtures thereof or admixtures thereof with hydrogen peroxide.

32. The method of claim 31 wherein the solid particulate material is sand.

33. The method of claim 32 wherein the formed shape, after contact with sulfur dioxide, is purged with air or inert gas and baked at an elevated temperature.