Diphenylguanidine-free rubber mixtures containing short-chain alkyl esters of glycerin

Patent metadata

Field	Value
Publication number	US-10150853-B2
Application number	US-201515315510-A
Country	US
Kind code	B2
Filing date	Jun 2, 2015
Priority date	Jun 3, 2014
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

The invention relates to substantially diphenylguanidine-free rubber mixtures comprising at least one rubber, one silica-based filler and/or carbon black and short-chain alkyl esters of glycerol, production of these, use and vulcanizates thus obtainable.

First claim

What is claimed is:

1. A substantially diphenylguanidine-free rubber mixture comprising:
at least one non-polar rubber selected from the group consisting of natural rubber (NR), styrene/butadiene rubber (SBR), polybutadiene rubber (BR), polyisoprene rubber (IR), isobutylene/isoprene rubber (IIR), epoxidized natural rubber (ENR) and ethylene/propylene/diene rubber EPDM,
a silica-based filler and/or carbon black,
a short-chain alkyl ester of glycerol according to formula (I)

in which R 1 , R 2 , and R 3 are mutually independently hydrogen or a straight-chain or branched C 1 -C 4 -alkyl moiety, and

an anti-reversion agent.

2. The rubber mixture according to claim 1 , wherein:
the rubber mixture comprises at most 1 phr of diphenylguanidine; and
the anti-reversion agent is selected from 1,6-bis(N,N-dibenzylthiocarbamoyldithio)hexane (CAS No.: 151900-44-6), 1,3-bis((3-methyl-2,5-dioxopyrrol-1-yl)methyl)benzene (CAS No. 119462-56-5), hexamethylene 1,6-bis(thiosulphate), and mixtures thereof.

3. The rubber mixture according to claim 1 , wherein:
the anti-reversion agent comprises 1,6-bis(N,N-dibenzylthiocarbamoyldithio) hexane (CAS No. 151900-44-6); and
the mixture comprises 0.1 to 15 phr of the 1,6-bis(N,N-dibenzylthiocarbamoyldithio) hexane (CAS No. 151900-44-6).

4. The rubber mixture according to claim 1 , wherein
the rubber mixture has a total content of, non-polar rubbers of at least 50 phr; and
the rubber mixture has at most 1 phr of diphenylguanidine.

5. The rubber mixture according to claim 1 , further comprising polar rubbers, where an individual content of any of butadiene/acrylonitrile rubber (NBR), partially or fully hydrogenated NBR (HNBR), partially or fully hydrogenated carboxylated nitrile butadiene rubber (HXNBR) and carboxylated nitrile butadiene rubber (XNBR) is smaller than 10 phr.

6. The rubber mixture according to claim 1 , further comprising at least one crosslinking agent.

7. The rubber mixture according to claim 1 , wherein the mixture comprises 0.1 to 40 phr of compounds of the formula (I).

8. The rubber mixture according to claim 1 , wherein the mixture comprises 50 to 100 phr of the silica-based filler and 0.2 to 12 phr of organic silanes.

9. The rubber mixture according to claim 1 , wherein the compound of the formula (I) is absorbed and/or adsorbed on a carrier selected from the group consisting of natural and synthetic silicates, aluminium oxide, carbon black and zinc oxide.

10. The rubber mixture according to claim 1 , wherein the rubber mixture has a cellulose and/or cellulose derivatives content of 0 to ≤1 phr.

11. A process for the production of the rubber mixture according to claim 1 , the process comprising mixing the at least one rubber, the silica-based filler and/or carbon black, the short-chain alkyl ester of glycerol according to formula (I), and the anti-reversion agent with one another at a temperature of 40 to 200° C.

12. A process for the production of rubber vulcanizates, the process comprising vulcanizing the rubber mixture according to claim 1 at a temperature of 100 to 250° C.

13. Vulcanizates obtained via vulcanization of rubber mixtures according to claim 1 .

14. Rubber products comprising one or more rubber vulcanizates according to claim 13 .

15. The rubber mixture according to claim 1 , wherein:
the at least one non-polar rubber is selected from the group consisting of NR, SBR and BR;
R 1 , R 2 , and R 3 are mutually independently hydrogen or methyl; and
the rubber mixture has at most 1 phr of diphenylguanidine.

16. The rubber mixture according to claim 15 , wherein the compound of the formula (I) is triacetin.

17. The rubber mixture according to claim 15 , wherein the rubber mixture comprises:
a total non-polar rubber content of at least 60 phr,
a content of compounds of the formula (I) of 0.2 to 20 phr, and
0.1 to 2 phr of 1,6-bis(N,N-dibenzylthiocarbamoyl dithio) hexane as the anti-reversion agent.

18. The rubber mixture according to claim 17 , further comprising:
polar rubbers, where an individual content of any of butadiene/acrylonitrile rubber (NBR), partially or fully hydrogenated NBR (HNBR), partially or fully hydrogenated carboxylated nitrile butadiene rubber (HXNBR) and carboxylated nitrile butadiene rubber (XNBR) is less than 0.01 phr;
at least one crosslinking agent selected from the group consisting of sulphur, dimorpholyl disulphide (DTDM), 2-morpholinodithiobenzothiazole (MBSS), caprolactam disulphide, dipentamethylenethiuram tetrasulphide (DPTT), tetramethylthiuram disulphide (TMTD) and tetrabenzylthiuram disulphide (TBzTD);
50 to 100 phr of the silica-based filler and 0.2 to 12 phr of sulphur-containing organic silanes; and
a cellulose and/or cellulose derivatives content of 0 to ≤1 phr.

19. The rubber mixture according to claim 15 , wherein:
the compound of the formula (I) is triacetin;
the rubber mixture comprises:
at least 70 phr of the non-polar rubbers,
0.2 to 1 phr of 1,6-bis(N,N-dibenzylthiocarbamoyl dithio) hexane;
3 to 8 phr of compounds of the formula (I);
less than 0.1 phr of diphenylguanidines; and
no cellulose and/or cellulose derivatives; and

the compounds of the formula (I) are absorbed and/or adsorbed on a carrier selected from the group comprising natural and synthetic silicates, aluminium oxide, carbon black and zinc oxide.

Assignees

• Lanxess Deutschland Gmbh

Inventors

• Feldhues Ulrich
• Unterberg Heinz
• Weidenhaupt Hermann-Josef
• Wiedemeier-Jarad Melanie

Classifications

• C08K5/103

  with polyalcohols · CPC title

• C08K3/04 Primary

  Carbon · CPC title

• C08L21/00

  Compositions of unspecified rubbers · CPC title

• C08K3/36

  Silica · CPC title

• B60C1/00

  Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition · CPC title