High temperature resistant conveyor belt

Patent metadata

Field	Value
Publication number	US-12030724-B2
Application number	US-202217809274-A
Country	US
Kind code	B2
Filing date	Jun 28, 2022
Priority date	Jun 28, 2022
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

Heavy duty conveyor belts having excellent resistance to high temperatures. These conveyor belts can be repeatedly exposed to temperatures of greater than 150° C. or even greater than 200° C. without compromising the strength or reliability of the belt while providing a greatly extended service life. The conveyor belts generally include a reinforcement layer, a carry cover layer disposed above the reinforcement layer, a pulley cover layer disposed beneath the reinforcement layer. The carry cover layer contains a high temperature resistant compound based upon a peroxide curable rubber mixture of ethylene propylene copolymer with ethylene based polyolefin elastomer, and in some aspects, further includes a combination of diphenylamine (DPA), zinc 2-mercaptomethyl benzimidazole (ZMTI), and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), and additionally, any other suitable additives.

First claim

What is claimed is:

1. A conveyor belt comprising a reinforcement layer, a carry cover layer above the reinforcement layer, and a pulley cover layer beneath the reinforcement layer, wherein the carry cover layer comprises a peroxide curable rubber mixture of ethylene propylene copolymer and ethylene based polyolefin elastomer, and wherein the peroxide curable rubber mixture further comprises diphenylamine (DPA), zinc 2-mercaptomethyl benzimidazole (ZMTI), and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ).

2. The conveyor belt according to claim 1 , wherein the peroxide curable rubber mixture has, after curing, a heat aged elongation % of more than 50% after 240 hours of heat exposure at 177° C., and wherein the elongation testing is performed according to ASTM D412.

3. The conveyor belt according to claim 2 , wherein the heat aged elongation % is more than 60%.

4. The conveyor belt according to claim 3 , wherein the heat aged elongation % is more than 64.0%.

5. The conveyor belt according to claim 1 , wherein the ethylene based polyolefin elastomer is a straight chain ethylene based polyolefin elastomer.

6. The conveyor belt according to claim 5 , wherein the straight chain ethylene based polyolefin elastomer is devoid of branching by copolymerization with propylene.

7. The conveyor belt according to claim 1 , wherein the ethylene based polyolefin elastomer has branching by copolymerization with propylene.

8. The conveyor belt according to claim 1 , wherein the ethylene based polyolefin elastomer is incorporated into the peroxide curable rubber mixture in an amount of from 20 to 50 parts per hundred (phr) rubber weight.

9. The conveyor belt according to claim 1 , wherein the ethylene propylene copolymer is incorporated into the peroxide curable rubber mixture in an amount of from 45 to 85 parts per hundred (phr) rubber weight.

10. A conveyor belt comprising a reinforcement layer, a carry cover layer above the reinforcement layer, and a pulley cover layer beneath the reinforcement layer, wherein the carry cover layer comprises a peroxide curable rubber mixture of ethylene propylene copolymer and ethylene based polyolefin elastomer, and wherein the peroxide curable rubber mixture further comprises a heat aged elongation extension package.

11. The conveyor belt according to claim 10 , wherein the peroxide curable rubber mixture has, after curing, a heat aged elongation % of more than 50% after 240 hours of heat exposure at 177° C., and wherein the elongation testing is performed according to ASTM D412.

12. The conveyor belt according to claim 11 , wherein the heat aged elongation % is more than 60%.

13. The conveyor belt according to claim 12 , wherein the heat aged elongation % is more than 64.0%.

14. The conveyor belt according to claim 10 , wherein a heat aged elongation extension package consists of at least two members selected from the group consisting of diphenylamine (DPA), zinc 2-mercaptomethyl benzimidazole (ZMTI), and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ).

15. The conveyor belt according to claim 10 , wherein a heat aged elongation extension package consists of diphenylamine (DPA), zinc 2-mercaptomethyl benzimidazole (ZMTI), and 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ).

16. The conveyor belt according to claim 10 , wherein the peroxide curable rubber mixture has, after curing, a heat aged elongation % of more than 20% after 240 hours of heat exposure at 177° C., and wherein the elongation testing is performed according to ASTM D412.

17. The conveyor belt according to claim 10 , wherein the ethylene based polyolefin elastomer is a straight chain ethylene based polyolefin elastomer.

18. The conveyor belt according to claim 17 , wherein the straight chain ethylene based polyolefin elastomer is devoid of branching by copolymerization with propylene.

19. The conveyor belt according to claim 10 , wherein the ethylene based polyolefin elastomer is incorporated into the peroxide curable rubber mixture in an amount of from 20 to 50 parts per hundred (phr) rubber weight.

20. The conveyor belt according to claim 10 , wherein the ethylene propylene copolymer is incorporated into the peroxide curable rubber mixture in an amount of from 45 to 85 parts per hundred (phr) rubber weight.

Assignees

• Contitech Transportbandsysteme

Inventors

• Prater Grant

Classifications

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L23/16

  Ethylene-propylene or ethylene-propylene-diene copolymers · CPC title

• B65G2207/22

  Heat or fire protection · CPC title

• B29D29/06

  Conveyor belts · CPC title

• B65G15/38

  with flame-resistant layers, e.g. of asbestos, glass · CPC title