Claims
- 1. A process for the preparation of a binding agent mixture comprising reacting a low molecular weight lignin from the Organosolv process with phenol in a weight ratio of 1:20 to 3:1 at 100.degree. to 180.degree. C., adjusting the pH to an acidic value and condensing the mixture with 0.2 to 0.9 moles of formaldehyde per mole of phenol at 60.degree. to 120.degree. C. to form the binding agent, intensively mixing the resulting lignin-phenol novalac with a phenol novolac in a weight ratio of 10:90 to 90:10 at 100.degree. to 200.degree. C., cooling and optionally drying the homogeneous mixture and granulating or finely grinding the mixture to form a powdered binding agent.
- 2. The process of claim 1 wherein the weight ratio of lignin-phenol phenol novolac to phenol novolac is 30:70 to 70:30.
- 3. The process of claim 1 wherein the intensive mixing is effected at 130.degree. to 160.degree. C.
- 4. The process of claim 1 wherein the intensive mixing is effected with a kneader or extruder under high shear forces.
- 5. The process of claim 1 wherein the lignin-phenol novolac and the phenol novolac are dissolved in a weight ratio of 30:70 to 70:30 in a solvent selected from the group consisting of methanol, ethanol, isopropanol, acetone, furfuryl alcohol and ethylene glycol.
- 6. The process of claim 5 wherein the weight ratio of lignin-phenol novolac to phenol novolac is 45:55 to 55:45.
- 7. A binding agent mixture produced by the process of claim 1.
- 8. A binding agent mixture of claim 7 also containing a curing agent selected from the group consisting of hexamethylenetetramine and a reactive resin selected from the group consisting of phenol resol, epoxy resin and nitrogen containing polymers.
Priority Claims (1)
Number |
Date |
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Kind |
4136563 |
Nov 1991 |
DEX |
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Parent Case Info
This is a division of Ser. No. 966,298, filed Oct. 26, 1992, now U.S. Pat. No. 5,260,405.
US Referenced Citations (10)
Divisions (1)
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Number |
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966298 |
Oct 1992 |
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