Rubber composition and a rubber product

Abstract

The present invention is directed to a rubber composition comprising 100 phr of at least one diene-based rubber, 30 phr to 250 phr of at least one filler, and 1 phr to 40 phr of an epoxidized and aminated fatty acid ester, wherein the epoxidized and aminated fatty acid ester is obtained from the reaction of an epoxidized fatty acid ester with an aliphatic amine. Furthermore, the present invention is directed to a rubber product, such as a tire, comprising such a rubber composition.

Claims

1. A rubber composition comprising: 100 phr of at least one diene-based elastomer, 30 phr to 250 phr of at least one filler, and 1 phr to 40 phr of an epoxidized and aminated fatty acid ester, wherein the epoxidized and aminated fatty acid ester is obtained from the reaction of an epoxidized fatty acid ester with an aliphatic amine.

2. The rubber composition of claim 1 wherein the aliphatic amine is a dialkyl amine having alkyl groups that contain from 1 to 8 carbon atoms.

3. The rubber composition of claim 2 wherein the aliphatic amine is a secondary non-cyclic amine.

4. The rubber composition of claim 1 wherein the fatty acid ester is a mono glyceride.

5. The rubber composition of claim 1 wherein the fatty acid ester is a diglyceride.

6. The rubber composition of claim 1 wherein the fatty acid ester is a triglyceride.

7. The rubber composition of claim 6 wherein the triglyceride is a vegetable oil which is selected from the group consisting of sunflower oil, soybean oil, palm oil, canola oil, rapeseed oil, corn oil, coconut oil, cottonseed oil, olive oil, peanut oil, and safflower oil.

8. The rubber composition of claim 1 wherein the fatty acid ester comprises at least one fatty acid chain, wherein at least all but one of the double bonds of each fatty acid chain are epoxidized.

9. The rubber composition of claim 1 wherein the degree of amination of the epoxidized double bonds is within a range of 5% to 90%.

10. The rubber composition of claim 1 wherein said at least one filler comprises from 50 phr to 250 phr of silica, and wherein said silica has a surface area within a range of 80 m.sup.2/g to 250 m.sup.2/g as determined in accordance with ASTM D5604-96, and wherein said silica has 5 to 15 silanol groups per square nanometer surface area.

11. The rubber composition of claim 1 wherein the epoxidized and aminated fatty acid ester is present at a level which is within the range of 1.5 phr to 15 phr.

12. The rubber composition of claim 1 wherein the rubber composition comprises a liquid plasticizer, wherein the ratio between the liquid plasticizer and the epoxidized and aminated fatty acid ester ranges from 20:1 to 3:1.

13. The rubber composition of claim 1, wherein said diene based rubber is further comprised of 60 phr to 100 phr of styrene butadiene rubber, and 0 phr to 40 phr of polybutadiene rubber.

14. The rubber composition of claim 1 wherein said styrene butadiene rubber has a glass transition temperature within a range of −85° C. to −5° C. and wherein the polybutadiene has a glass transition temperature which is within a range of −85° C. to −110° C.

15. The rubber composition of claim 1 wherein the epoxidized and aminated fatty acid ester comprises at least one fatty acid residue comprising from 1 to 4 epoxy groups, from 1 to 4 hydroxyl groups and from 1 to 4 amine groups.

16. The rubber composition of claim 1 wherein the aliphatic amine is selected from the group consisting of dimethylamine, diethylamine, di-n-propylamine, di-iso-propylamine, di-n-butylamine, di-iso-butylamine, di-t-butylamine, dipentylamines, dihexylamines, diheptylamines, and dioctylamines, bis(cyclohexylmethyl)amine, N-methylbenzylamine, N-ethylbenzylamine, N-isopropylbenzylamine, dibenzylamine, N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N-isopropylethanolamine, N-butylethanolamine, diethanolamine, diisopropanolamine, and bis(2-methoxyethyl)amine.

17. A rubber product comprising the rubber composition of claim 1 the rubber product is selected from a tire, a power transmission belt, a hose, a track, an air sleeve, and a conveyor belt.

18. A tire comprising one or more rubber components selected from a tread, a shear-band, rubber spokes, an under-tread, a sidewall, an apex, a flipper, a chipper, a chafer, a carcass, a belt, an overlay, and wherein one or more of the rubber components are comprised of the rubber composition of claim 1.

19. A rubber composition comprising: 100 phr of at least one diene-based elastomer, 30 phr to 250 phr of at least one filler, and 1 phr to 40 phr of an epoxidized and aminated fatty acid ester, wherein the epoxidized and aminated fatty acid ester is obtained from the reaction of an epoxidized fatty acid ester with a secondary amine having the following structure: ##STR00004## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are independently selected from hydrogens, linear or branched alkyl groups, cycloalkyl groups, aryl groups, hydroxyalkyl groups or alkoxyalkyl groups.

20. The rubber composition of claim 19 wherein the molecular weight of the secondary amine does not exceed 555 g/mol.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The structure, operation, and advantages of the invention will become more apparent upon contemplation of the following description taken in conjunction with the accompanying drawings, wherein FIG. 1 is a schematic cross section of a tire comprising a rubber component with the rubber composition in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(2) FIG. 1 is a schematic cross-section of a tire 1 according to an embodiment of the invention. The tire 1 has a plurality of tire components such as a tread 10, an innerliner 13, a belt comprising four belt plies 11, a carcass ply 9, two sidewalls 2, and two bead regions 3, bead filler apexes 5 and beads 4. The example tire 1 is suitable, for example, for mounting on a rim of a vehicle, e.g. a truck or a passenger car. As shown in FIG. 1, the belt plies 11 may be covered by an overlay ply 12 and/or may include one or more breaker plies. The carcass ply 9 includes a pair of axially opposite end portions 6, each of which is associated with a respective one of the beads 4. Each axial end portion 6 of the carcass ply 9 may be turned up and around the respective bead 4 to a position to anchor each axial end portion 6. The turned-up portions 6 of the carcass ply 9 may engage the axial outer surfaces of two flippers 8 and axial inner surfaces of two chippers 7 which are also considered as tire components. As shown in FIG. 1, the example tread 10 may have circumferential grooves 20, each groove 20 essentially defining a U-shaped opening in the tread 10. The main portion of the tread 10 may be formed of one or more tread compounds. Moreover, the grooves 20, in particular the bottoms and/or sidewalls of the grooves 20 could be reinforced by a rubber compound having a higher hardness and/or stiffness than the remaining tread compound. Such a reinforcement may be referred to herein as a groove reinforcement.

(3) While the embodiment of FIG. 1 suggests a plurality of tire components including for instance apexes 5, chippers 7, flippers 8 and overlay 12, such and further components are not mandatory for the invention. Also, the turned-up end of the carcass ply 9 is not necessary for the invention or may pass on the opposite side of the bead area 3 and end on the axially inner side of the bead 4 instead of the axially outer side of the bead 4. The tire could also have for instance a different number of grooves 20, e.g. less than four grooves.

(4) One or more of the above tire components are made of a rubber composition in accordance with an embodiment of the present invention which comprises in a non-limiting example a blend of a solution polymerized styrene-butadiene rubber and a polybutadiene rubber, 80 phr of silica as a filler, and from 1.5 phr to 8 phr of an epoxidized and aminated triglyceride. In the present example, the epoxidized and aminated triglyceride has been prepared on the basis of soybean oil.

(5) As shown in below Table 1, Inventive Examples 1, 2, 3, 4, and 5, which are in accordance with embodiments of the present invention, comprise styrene butadiene rubber, polybutadiene, silica, TDAE oil and different amounts of epoxidized and aminated soybean oil. The Control Sample does not comprise any epoxidized and aminated vegetable oil but comprises only 26 phr TDAE oil instead.

(6) TABLE-US-00001 TABLE 1 phr Control Inventive Inventive Inventive Inventive Inventive Materials Sample Example 1 Example 2 Example 3 Example 4 Example 5 SBR.sup.1 80 80 80 80 80 80 Polybutadiene.sup.2 20 20 20 20 20 20 Silica.sup.3 80 80 80 80 80 80 Epoxidized and aminated 0 1.5 3 4.5 6 8 vegetable oil.sup.4 TDAE Oil 26 24.5 23 21.5 20 18 Zinc Oxide 2.5 2.5 2.5 2.5 2.5 2.5 Stearic Acid 3 3 3 3 3 3 Silane.sup.5 8 8 8 8 8 8 Antidegradant 2.5 2.5 2.5 2.5 2.5 2.5 Sulfur 1.1 1.1 1.1 1.1 1.1 1.1 MBT.sup.6 0.3 0.3 0.3 0.3 0.3 0.3 DPG.sup.7 3.2 3.2 3.2 3.2 3.2 3.2 CBS.sup.8 2.3 2.3 2.3 2.3 2.3 2.3 .sup.1as Sprintan ™ SLR 4602 from the company Trinseo .sup.2as Budene 1229 from Goodyear Chemical .sup.3as Zeosil ™ Premium 200MP .sup.4as an epoxidized and aminated soybean oil, with fatty acid residues having on average about 1.2 double bonds aminated, with the rest of double bonds remaining epoxidized. The amination was carried out with diethylamine .sup.5as Si266 ™ from the company Evonik .sup.6benzothiazyl disulfide .sup.7diphenylguanidine .sup.8N-cyclohexyl-benzothiazole-2-sulfenamide

(7) Table 2 shows test data obtained with the Control Sample and the Inventive Examples listed above in Table 1. Mixing energy is reduced in the silica compound up to the order of 10% with increasing epoxidized and aminated vegetable oil content. However, a plateau may be reached at about 6 phr epoxidized and aminated vegetable load. Moreover, tensile strength and modulus improve significantly by more than 10% upon partial replacement of TDAE oil by the epoxidized an aminated vegetable oil.

(8) TABLE-US-00002 TABLE 2 Control Inventive Inventive Inventive Inventive Inventive Property Sample Example 1 Example 2 Example 3 Example 4 Example 5 Mixing energy [kJ] 155 152 148 144 141 141 Tensile strength [MPa] 13 15 15 15 15 15 Storage Modulus at 6.5 8.2 8.2 8.2 8.2 8.2 200% [MPa]

(9) While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention.