Precured coated particulate material
AssigneeAcme Resin Corporation
InventorDavid R. Armbruster
Life of this patent
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Abstract
The present invention relates to coated particulate matter wherein the particles are individually coated with a cured combination of phenolic/furan resin or furan resin to form a precured resin coating on a proppant such as sand, thereby substantially improving the chemical resistance of the proppant over one having a straight phenolic precured coating. Another embodiment of this invention involves the use of multiple resin coatings on the particulate matter to form a final layered coating containing the desired amount of cured resin. This multiple coating of particulate material results in a final coated product that has a smoother and more uniform surface than particulate material having its entire resin coating applied in a single operation.
Claims36
Coated particulate material consisting essentially of particles resistant to melting at temperatures below about 450.degree. F., said particles individually coated with one or more layers of a cured resin selected from the group consisting of:
- (a) the combination of a phenolic resin and a furan resin;
- or
- (b) the terpolymer of a phenol, furfuryl alcohol and an aldehyde.
A process for producing coated particulate material consisting essentially of particles resistant to melting at temperatures below about 450.degree. F., comprising:
- mixing an uncured thermosetting resin with said particulate matter preheated to temperatures of about 225.degree.-450.degree. F., wherein the resin is selected from the group consisting of furan, the combination of a phenolic resin and a furan resin, or a terpolymer of phenol, furfuryl alcohol and formaldehyde;
- maintaining the particulate matter-resin mixture at a temperature of above about 200.degree. F. for a time sufficient to cure the resin.
A process for preparing particulate matter coated with incremental layers of a cured resin, comprising:
- (a) mixing an incremental amount of uncured resin selected from the group consisting of furan, the combination of a phenolic resin and a furan resin, or a terpolymer of phenol, furfuryl alcohol and formaldehyde, with particulate matter resistant to melting at temperatures of about 450.degree. F., and heating at a temperature of about 225.degree.-450.degree. F. for a time sufficient to coat said particulate matter with the resin;
- (b) contacting the resin coated particulate matter with a catalyst selected from the group consisting of:
- (i) acids with a pKa of about 4.0 or lower;
- (ii) water soluble multivalent metal ion salts;
- and
- (iii) ammonia or amine salts of acids with a pKa of about 4.0 or lower;
- and
- (c) repeating steps (a) and (b) until the total amount of resin coated on the particulate matter in incremental multiple layers is sufficient to produce a final coated particulate product that has a smoother and more uniform surface than if the total amount of resin was added in one application.
Dependencies are inferred from the claim text.