Method for coating particulate material thereof

• US 3,935,339 A
• Filed: 07/16/1973
• Issued: 01/27/1976
• Est. Priority Date: 07/16/1973
• Status: Expired due to Term

• Current Assignee: Exxon Production Research Company (Exxon Mobil Corporation)
• Original Assignee: Exxon Production Research Company (Exxon Mobil Corporation)
• Inventors: Cooke, Claude E. Jr.
• Primary Examiner(s): Husack, Ralph
• Assistant Examiner(s): Konopacki, Dennis C.
• Application Number:
  US05/379,286
• Time in Patent Office: 925 Days
• Field of Search: 117/100 S, 117/100 A, 117/100 B, 117/100 M, 117/100 C, 117/100 D, 117/123 D, 117/119.6, 117/62.2, 117/109, 260/42.53, 106/308 M, 427/212, 427/216, 427/221, 427/340, 427/386, 427/388
• US Class Current: 427/216
• CPC Class Codes: B22C 1/226 Polyepoxides
• CPC Class Codes: C04B 14/00 Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone expanding or defibrillating materials C04B20/00
• CPC Class Codes: C04B 20/1037 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2996 Glass particles or spheres

Abstract

A Method of coating particulate materials (such as silica sand, glass beads, seeds and metal particles) with a liquid thermosetting epoxy resin which comprises agitating the epoxy resin with the particles in a nonpolar liquid, which is immiscible with the epoxy resin, and contains a nonionic surfactant having a molecular weight of at least 2,000 to retard the tendency of the epoxy coated particles to agglomerate during curing of the resin in the non-polar liquid. A suitable liquid for use as the immiscible liquid is a paraffinic oil which is aromatic-free and olefin-free.

Claims

1. A method of forming free-flowing resin-coated particles which comprises:

a. coating the particles of a particular substrate material with a liquid thermosetting epoxy resin;

b. in the presence of a curing agent capable of curing said epoxy resin to a solid infusible state, agitating said coated particles in a nonpolar liquid immiscible with said liquid resin and containing a nonionic surfactant having a molecular weight of at least 2000 which retards agglomeration of said resin coated particles until said epoxy resin cures to a solid, infusible state; and

thereafter

c. removing the coated particles from said immiscible liquid.

2. A method as defined in claim 1 wherein said particles are silica sand.

3. A method as defined in claim 1 wherein said particles are metal particles.

4. A method as defined in claim 3 wherein said metal particles are of a ferroalloy.

5. A method as defined in claim 1 wherein said immiscible liquid comprises a hydrocarbon oil substantially free of aromatics and olefins.

6. A method as defined in claim 1 wherein said surfactant is a non-ionic surfactant having a molecular weight between 2000 and 10,000.

7. A method as defined in claim 1 wherein said surfactant is a condensate of ethylene oxide and propylene oxide with glycerine.

8. A method as defined in claim 1 wherein said surfactant is a condensate of ethylene oxide and propylene oxide with propylene glycol.

9. A method as defined in claim 1 wherein said liquid resin contains said curing agent.

10. A method as defined in claim 1 wherein the liquid resin deposited on the particles constitutes from 2 to 15 weight percent of the coated particles.

11. A method as defined in claim 10 wherein said liquid resin contains an organofunctional silane coupling agent.

12. A method as defined in claim 2 wherein said silica sand has a particle size between about 6 and 100 mesh on the U.S. Standard Sieve Series.

15. A method as defined in claim 12 wherein said nonionic surfactant is present in said nonpolar, immiscible liquid in a concentration between about 0.2 and about 3.0 weight percent.

16. A method as defined in claim 15 and further comprising heating said resin-coated particles to temperature sufficient to further cure the resin.

17. A method as defined in claim 1 wherein said curing agent is contained in said nonpolar liquid.

13. A method of coating particulate material with a resin to form free-flowing, non-sticky, resin-coated particles which comprises:

a. mixing said particulate material with a liquid thermosetting epoxy resin and a curing agent for said epoxy resin to deposit a coating which substantially covers each particle;

b. curing said coated particles in contact with a nonpolar liquid immiscible with said resin and a minor amount of a nonionic surfactant having a molecular weight of at least 2000 until said resin cures to a hard, infusible state, said surfactant having the ability to retard agglomeration of said resin-coated particles; and

thereafter

c. removing said bath liquid containing said surfactant.

14. A method as defined in claim 13 wherein sufficient liquid resin is mixed with said particulate material to deposit a resin coating on said particles of between about 5 and about 15 weight percent based on the weight of the coated particles.