Claims
- 1. A method for accelerating the ambient temperature hardening of a mixture of a phenolic resin and magnesia aggregate wherein the mixture has a pH of at least 4.5 which comprises mixing:
- A. magnesia aggregate;
- B. a curable phenolic resin solution selected from the group consisting of a novolac, a resole having a viscosity of about 100 to 10,000 cps at 25.degree. C., and mixtures thereof the quantity of said resin being sufficient to bind the aggregate on thermal curing of the resin; and
- C. an accelerator compound in an amount sufficient to accelerate the ambient temperature hardening of said mixture, said compound selected from the group consisting of: a compound which provides to the mixture 4-aminobenzenesufonate anions, acetylacetone, 2-nitrophenol, 4-nitrophenol, salicylaldehyde; and a mixture of said accelerator compounds; provided however that the resin is a resole when the compound provides 4-aminobenzenesulfonate anions.
- 2. The method of claim 1 wherein the aggregate is deadburned magnesia.
- 3. The method of claim 1 wherein the aggregate is hardburned magnesia.
- 4. The method of claim 1 wherein the resin is a resole resin having a pH of 5 to 8.5 and a viscosity of 250 to 5,000 cps at 25.degree. C.
- 5. The method of claim 1 wherein the phenolic resin is the condensation product of phenol and formaldehyde.
- 6. The method of claim 1 wherein the compound is acetylacetone.
- 7. The method of claim 1 wherein the phenolic resin is a solution of novolac in an organic solvent and the aggregate contains from about 1.5% to 4% of calcium oxide.
- 8. The method of claim 1 wherein the phenolic resin is a mixture containing from about 1 to 4 parts by weight of resole for each part of novolac.
- 9. The method of claim 1 wherein the mixture includes an additive selected from the group consisting of from about 5% to 35% of graphite based on the weight of aggregate, 1% to 5% by weight of a metal powder selected from the group consisting of aluminum, magnesium, and silicon based on the weight of aggregate, and mixtures of said additives.
- 10. The method of claim 1 wherein the accelerator is salicylaldehyde.
- 11. The method of claim 1 wherein the accelerator provides 4-aminobenzenesulfonate anions.
- 12. The method of claim 1 wherein the ambient temperature is from about 60.degree. F. to 90.degree. F.
- 13. The method of claim 2 wherein the mixture includes from about 5% to 25% by weight, based on the weight of the resin, of an ester functional hardening agent selected from the group consisting of a lactone, a carboxylic acid ester, a cyclic organic carbonate and mixtures thereof.
- 14. The method of claim 4 wherein the resin has a viscosity of from about 250 to 5,000 cps at 25.degree. C. and a solids content of about 50% to 90% by weight, the mixture contains from about 3% to 12% by weight of water, the magnesia contains less than 3% by weight of calcium oxide, and the phenolic resole is the condensation product of phenol and formaldehyde.
- 15. The method of claim 4 wherein the resole resin contains less than 1% by weight of sodium or potassium.
- 16. A binder-aggregate composition having a pH of at least 4.5 which comprises a wet mixture of:
- A. magnesia aggregate;
- B. a curable phenolic resin solution selected from the group consisting of a novolac, a resole having a viscosity of about 100 to 10,000 cps at 25.degree. C., and mixtures thereof, the quantity of said resin being from about 3% to 15% by weight of the magnesia; and
- C. an accelerator compound in an amount sufficient to accelerate the ambient temperature hardening of said mixture, said compound selected from the group consisting of: a compound which provides to the mixture 4-aminobenzenesufonate anions, acetylacetone, 2-nitrophenol, 4-nitrophenol, salicylaldehyde; and a mixture of said accelerator compounds; provided however that the phenolic resin is a resole when the compound provides 4-aminobenzenesulfonate anions.
- 17. The composition of claim 16 wherein the phenolic resin is a resole having a viscosity of 250 to 5,000 cps at 25.degree. C. and wherein the resole contains from 3% to 15% by weight of water.
- 18. The composition of claim 16 wherein the compound is acetylacetone.
- 19. A binder-aggregate composition having a pH of at least 4.5 which comprises a wet mixture of:
- A. magnesia aggregate;
- B. a curable phenolic resole resin solution having a viscosity of about 100 to 10,000 cps at 25.degree. C., the quantity of said resin being from about 3% to 15% by weight of the magnesia; and
- C. a compound providing 4-aminobenzenesulfonate anions to the mixture in an amount sufficient to accelerate the ambient temperature hardening of said mixture.
- 20. The composition of claim 19 wherein the compound providing the resin is a resole.
Parent Case Info
This application is a divisional application of my copending application Ser. No. 07/943,046 filed on Sep. 10, 1992, now U.S. Pat. No. 5,218,010, which in turn is a divisional of my application Ser. No. 07/803,979 filed on Dec. 9, 1991, now U.S. Pat. No. 5,182,347, which is in turn is a continuation-in-part of my application Ser. No. 07/616,879 filed on Nov. 21, 1990, now U.S. Pat. No. 5,182,346, and which in turn is a continuation-in-part of Ser. No. 07/562,206 filed on Aug. 2, 1990, now U.S. Pat. No. 5,096,983 which issued on Mar. 17, 1992.
US Referenced Citations (22)
Foreign Referenced Citations (5)
Number |
Date |
Country |
0202004 |
Nov 1986 |
EPX |
57-051176 |
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JPX |
60-90251 |
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JPX |
89069046 |
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Divisions (2)
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Number |
Date |
Country |
Parent |
943046 |
Sep 1992 |
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Parent |
803979 |
Dec 1991 |
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Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
616879 |
Nov 1990 |
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Parent |
562206 |
Aug 1990 |
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