Flame-retardant abrasion-resistant conveyor belt

1 . A conveyor belt comprising:

a top cover layer,

a bottom cover layer, and

a reinforcement layer between the top and bottom cover layers,

wherein at least the top cover layer includes a cured elastomeric compound formed from a composition comprising:

one or more base elastomer(s);

one or more reinforcing agent(s) in a total amount from 30 phr to 80 phr;

flame retardants in a total amount from 20 phr to 65 phr;

wherein the flame retardants include:

one or more halogenated compound(s) in a total amount from 5 phr to 25 phr;

one or more antimony trioxide compound(s) in a total amount from 1 phr to 15 phr;

one or more alumina trihydrate compound(s) in a total amount from 2 phr to 25 phr; and

one or more intumescent graphite(s) in a total amount from 1 phr to 10 phr;

wherein the flame retardants cooperate in synergistic effect such that:

(i) the cured elastomeric compound has an afterglow value of less than 100 seconds in accordance with testing under ASTM D378 13.2 as associated with flame resistance; and

(ii) the cured elastomeric compound has a non-rotating DIN abrasion value from 5 mm 3 to 150 mm 3 according to DIN 53516, Method A as associated with abrasion resistance.

2 . The conveyor belt according to claim 1 , wherein:

the one or more base elastomers include a mixture of (i) one or more polybutadiene elastomers and (ii) one or more polyisoprene elastomer(s), wherein the base elastomers altogether constitute at least 90 phr of the base elastomers of the elastomeric composition;

the cured elastomeric compound has an afterglow value of less than 60 seconds in accordance with testing under ASTM D378 13.2 as associated with flame resistance; and

the cured elastomeric compound has a non-rotating DIN abrasion value from 10 mm 3 to 50 mm 3 according to DIN 53516, Method A as associated with abrasion resistance.

3 . The conveyor belt according to claim 1 , wherein:

the one or more base elastomers include a mixture of (i) one or more polybutadiene elastomers and (ii) one or more polyisoprene elastomer(s), wherein the base elastomers altogether constitute at least 90 phr of the base elastomers of the elastomeric composition;

the flame retardants are present in a total amount from 20 phr to 45 phr;

the one or more halogenated compound(s) are present in a total amount from 10 phr to 20 phr;

the one or more antimony trioxide compound(s) are present in a total amount from 1 phr to 5 phr;

the one or more alumina trihydrate compound(s) are present in a total amount from 5 phr to 15 phr;

the one or more intumescent graphite(s) are present in a total amount from 3 phr to 10 phr;

the cured elastomeric compound has an afterglow value of 40 seconds or less in accordance with testing under ASTM D378 13.2 as associated with flame resistance; and

the cured elastomeric compound has a non-rotating DIN abrasion value from 10 mm 3 to 50 mm 3 according to DIN 53516, Method A as associated with abrasion resistance.

4 . The conveyor belt according to claim 3 , wherein:

the one or more intumescent graphite(s) are present in a total amount from 3 phr to 5 phr; and

the cured elastomeric compound has a non-rotating DIN abrasion value from 10 mm 3 to 30 mm 3 according to DIN 53516, Method A as associated with abrasion resistance.

5 . The conveyor belt according to claim 4 , wherein:

the one or more polybutadiene elastomers are present in an amount of at least 80 phr and the one or more polyisoprene elastomer(s) are present in an amount of at least 10 phr.

6 . The conveyor belt according to claim 5 , wherein:

the one or more reinforcing agent(s) consist of only one or more carbon black(s) which is/are present in total amount from 30 phr to 80 phr.

7 . The conveyor belt according to claim 1 , wherein:

the one or more halogenated compound(s) includes decabromodiphenyl ethane(s).

8 . The conveyor belt according to claim 1 , wherein:

the one or more antimony trioxide compound(s) have at least 90% Sb 2 O 3 .

9 . The conveyor belt according to claim 1 , wherein:

the one or more alumina trihydrate compound(s) consist essentially of 100% alumina trihydrate.

10 . The conveyor belt according to claim 1 , wherein:

the one or more intumescent graphite(s) have an expansion ratio in a range from 250:1 to 350:1.

11 . The conveyor belt according to claim 10 , wherein:

the one or more intumescent graphite(s) have an average particle size in a range from 200 microns to 400 microns.

12 . The conveyor belt according to claim 1 , wherein:

the flame retardants form a flame-retardant system which is the only flame retardant system in the composition, the flame-retardant system consisting essentially of the one or more halogenated compound(s), the one or more antimony trioxide compound(s), the one or more alumina trihydrate compound(s), and the one or more intumescent graphite(s), which are present in a total amount from 20 phr to 45 phr.

13 . The conveyor belt according to claim 1 , wherein:

the composition is devoid of styrene butadiene elastomer (SBR), ethylene propylene diene monomer (EPDM) elastomer, ethylene vinyl acetate elastomer (EVM), nitrile butadiene elastomer (NBR), and chlorinated polyethylene (CPE).

14 . A method of improving a conveyor belt, comprising:

providing a top cover layer, a bottom cover layer, and a reinforcement layer between the top and bottom cover layers to form the conveyor belt, wherein at least the top cover layer includes a cured elastomeric compound formed from a composition comprising: one or more base elastomer(s) and one or more reinforcing agent(s) in a total amount from 30 phr to 80 phr;

improving a combination of both abrasion resistance and flame resistance of the cured elastomeric compound by incorporating a flame-retardant system into the composition, in which the flame-retardant system includes flame retardants in a total amount from 20 phr to 65 phr;

wherein the flame retardants include:

one or more halogenated compound(s) in a total amount from 5 phr to 25 phr;

one or more antimony trioxide compound(s) in a total amount from 1 phr to 15 phr;

one or more alumina trihydrate compound(s) in a total amount from 2 phr to 25 phr; and

one or more intumescent graphite(s) in a total amount from 1 phr to 10 phr;

wherein the improving the combination of both the abrasion resistance and the flame resistance is provided by the flame retardants cooperating in synergistic effect such that: (i) the cured elastomeric compound has an afterglow value of less than 100 seconds in accordance with testing under ASTM D378 13.2 as associated with flame resistance; and (ii) the cured elastomeric compound has a non-rotating DIN abrasion value from 5 mm 3 to 150 mm 3 according to DIN 53516, Method A as associated with abrasion resistance.

15 . A conveyor belt comprising:

a top cover layer,

a bottom cover layer, and

a reinforcement layer between the top and bottom cover layers,

wherein at least the top cover layer includes a cured elastomeric compound formed from a composition comprising:

one or more base elastomer(s), the one or more base elastomers including a mixture of (i) one or more polybutadiene elastomers and (ii) one or more polyisoprene elastomer(s), wherein the base elastomers altogether constitute at least 90 phr of the base elastomers of the elastomeric composition, the one or more polybutadiene elastomers being present in an amount of at least 80 phr and the one or more polyisoprene elastomer(s) being present in an amount of at least 10 phr;

one or more reinforcing agent(s) in a total amount from 30 phr to 80 phr, the one or more reinforcing agent(s) consisting of only carbon black(s) which is/are present in total amount from 30 phr to 80 phr;

a single flame-retardant system consisting of a plurality of flame retardants present in a total amount from 20 phr to 45 phr, wherein the plurality of flame retardants consist of:

one or more halogenated compound(s) in a total amount from 10 phr to 20 phr, the one or more halogenated compound(s) including decabromodiphenyl ethane(s);

one or more antimony trioxide compound(s) in a total amount from 1 phr to 5 phr, the one or more antimony trioxide compound(s) having at least 90% Sb 2 O 3 ;

one or more alumina trihydrate compound(s) in a total amount from 5 phr to 15 phr, the one or more alumina trihydrate compound(s) consisting essentially of 100% alumina trihydrate; and

one or more intumescent graphite(s) in a total amount from 3 phr to 5 phr, the one or more intumescent graphite(s) having an expansion ratio in a range from 250:1 to 350:1, and having an average particle size in a range from 200 microns to 400 microns;

wherein the flame retardants cooperate in synergistic effect such that:

(i) the cured elastomeric compound has an afterglow value of 40 seconds or less in accordance with testing under ASTM D378 13.2 as associated with flame resistance; and

(ii) the cured elastomeric compound has a non-rotating DIN abrasion value from 10 mm 3 to 30 mm 3 according to DIN 53516, Method A as associated with abrasion resistance.