Claims
- 1. An asbestos-cement product having bonded thereto a thin protective coating of a cured latex composition comprising a styrene-butadiene copolymer, the product being formed by the process comprising:
- forming the asbestos-cement product from an aqueous slurry of asbestos fibers and cement on a means for forming a product of predetermined dimension;
- removing the product from the means for forming the product;
- coating the product with a latex composition comprising a styrene-butadiene copolymer to a predetermined thickness;
- autoclaving the coated product for a predetermined time at a predetermed pressure and temperature in order to bond the latex composition to the asbestos-cement product;
- cooling the product to a predetermined temperature.
- 2. The product of claim 1 wherein the asbestos-cement product is precured for a predetermined time and temperature before autoclaving.
- 3. The product of claim 1 wherein the asbestos-cement product is precured for a predetermeined time and temperature before removal from the forming means, and precured for a second pretetermined time and temperature before autoclaving.
- 4. The product of claim 1 wherein the styrene-butadiene copolymer is unsaturated.
- 5. The product of claim 4 wherein the styrene-butadiene copolymer contains a vulcanizing agent.
- 6. The product of claim 5 wherein the styrene-butadiene copolymer contains an antioxidant and a filler.
- 7. The product of claim 1 wherein the copolymer coating thickness ranges from about 2 to 20 mils.
- 8. The product of claim 1 wherein the asbestos-cement product is autoclaved for about 8-16 hours at about 130-160 psi and about 345.degree.-375.degree. F.
- 9. The product of claim 1 being a pipe.
- 10. The product of claim 9 wherein the coating is applied to the interior surface thereof.
- 11. The product of claim 1 wherein the aqueous slurry of asbestos and cement contains silica.
CROSS-REFERENCE
This application is a division, of application Ser. No. 448,482, filed Dec. 10, 1980, now U.S. Pat. No. 4,489,109.
US Referenced Citations (8)
Foreign Referenced Citations (2)
Number |
Date |
Country |
2446703 |
Apr 1976 |
DEX |
0031000 |
Mar 1980 |
JPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
448482 |
Dec 1980 |
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