Phenolic resin composition and the use thereof in a rubber composition to reduce hysteresis

1. A phenolic resin composition comprising:

a phenolic resin admixed with and/or modified by one or more functionalized organosulfur compounds, wherein the organosulfur compound is a thiol, disulfide, polysulfide, or thioester compound, and wherein the functionalization of the organosulfur compound comprises one or more phenolic moieties having one or more unsubstituted para- or ortho-positions, at least one phenolic moiety being bonded to the thiol, disulfide, polysulfide, or thioester moiety through a linking moiety and at least one heteroatom-containing divalent moiety selected from the group consisting of imine, amine, amide, imide, ether, and ester moiety.

2. The phenolic resin composition of claim 1 , wherein the phenolic resin composition comprises the admixture of the phenolic resin and the functionalized organosulfur compounds.

3. The phenolic resin composition of claim 1 , wherein the phenolic resin composition comprises the reaction product of:

at least one phenolic compound,

at least one aldehyde, and

the one or more functionalized organosulfur compounds.

4. The phenolic resin composition of claim 1 , wherein the phenolic resin is a monohydric- or dihydric-phenolic-aldehyde resin, optionally modified by a naturally-derived organic compound containing at least one unsaturated bond.

5. The phenolic resin composition of claim 1 , wherein the phenolic resin is used as a bonding resin or a reinforcing resin.

6. The phenolic resin composition of claim 1 , wherein the amount of the functionalized organosulfur compound ranges from about 0.1 to about 25 wt %.

7. The phenolic resin composition of claim 1 , wherein the organosulfur compound is a thiol, disulfide, or thioester compound, having at least one functionalization connected to the thiol, disulfide, or thioester moiety through a linking moiety and at least an imine, amine, ether, or ester moiety.

8. The phenolic resin composition of claim 1 , wherein one or more organosulfur compounds have the structure of formula (B-1) or (B-2):

R 5 —R 3 —R 1 —X—R 2 —R 4 —R 6   (B-1)

or

R 5 —R 3 —R 1 —S—H  (B-2),

wherein:

X is S z or S—C(═O);

z is an integer from 2 to 10;

R 1 and R 2 each are independently a divalent form of C 1 -C 30 alkane, divalent form of C 3 -C 30 cycloalkane, divalent form of C 3 -C 30 heterocycloalkane, divalent form of C 2 -C 30 alkene, or combinations thereof; each optionally substituted by one or more alkyl, alkenyl, aryl, alkylaryl, arylalkyl, or halide groups;

R 3 and R 4 each are independently absent, or a divalent form of imine (—R′″—N═C(R′)—R′″—), amine (—R′″—N(R′)—R′″—), amide

imide

ether (—R′″—O—R′″—), or ester

provided that at least one of R 3 and R 4 is present;

R 5 and R 6 each are independently H, alkyl, aryl, alkylaryl, arylalkyl, acetyl, benzoyl, thiol, sulfonyl, nitro, cyano, epoxide

anhydride

acyl halide

alkyl halide, alkenyl, or a phenolic moiety having one or more unsubstituted para- or ortho-positions; provided that at least one of R 5 and R 6 is a phenolic moiety having one or more unsubstituted para- or ortho-positions; and provided that when R 3 is —R′″—O—R′″—, R 5 is not H, and when R 4 is —R′″—O—R′″—, R 6 is not H; and

each R′ is independently H or alkyl, each R″ is independently alkyl, and each R′″ is independently absent or divalent form of alkane.

9. A rubber composition, comprising:

(i) a rubber component comprising a natural rubber, a synthetic rubber, or a mixture thereof,

(ii) a phenolic resin component comprising one or more phenolic resins; and

(iii) an organosulfur component comprising one or more functionalized organosulfur compounds, wherein the organosulfur compound is a thiol, disulfide, polysulfide, or thioester compound, and wherein the functionalization of the organosulfur compound comprises one or more phenolic moieties having one or more unsubstituted para- or ortho-positions, at least one phenolic moiety being bonded to the thiol, disulfide, polysulfide, or thioester moiety through a linking moiety and at least one heteroatom-containing divalent moiety selected from the group consisting of imine, amine, amide, imide, ether, and ester moiety.

10. The rubber composition of claim 9 , wherein

component (ii) is pre-admixed with or pre-modified by component (iii).

11. The rubber composition of claim 9 , further comprising

one or more methylene donor agents.

12. The rubber composition of claim 9 , wherein the interaction between the component (i) and the components (ii) and (iii) reduces the hysteresis increase or heat buildup compared to a rubber composition without the component (iii).

13. The rubber composition of claim 12 , wherein the heat buildup, as measured by a flexometer, is reduced by at least about 1° C., compared to a rubber composition without the component (iii).

14. The rubber composition of claim 12 , wherein the hysteresis increase, as measured by tan δ, is reduced by at least about 10%, compared to a rubber composition without the component (iii).

15. The rubber composition of claim 9 , wherein the phenolic resin is a monohydric- or dihydric-phenolic-aldehyde resin, optionally modified by a naturally-derived organic compound containing at least one unsaturated bond.

16. The rubber composition of claim 9 , wherein the organosulfur compound is a thiol, disulfide, or thioester compound, having at least one functionalization connected to the thiol, disulfide, or thioester moiety through a linking moiety and an imine or ester moiety.

17. The rubber composition of claim 9 , wherein the amount of the components (ii) and (iii) in the rubber composition range from about 0.5 to about 50 parts per 100 parts rubber by weight.

18. A rubber product formed from the rubber composition of claim 9 .

19. A process for preparing a rubber composition, comprising:

mixing (i) a rubber component comprising a natural rubber, a synthetic rubber, or a mixture thereof, (ii) a phenolic resin component comprising one or more phenolic resins, and (iii) an organosulfur component comprising one or more functionalized organosulfur compounds, wherein the organosulfur compound is a thiol, disulfide, polysulfide, or thioester compound, and wherein the functionalization of the organosulfur compound comprises one or more phenolic moieties having one or more unsubstituted para- or ortho-positions, at least one phenolic moiety being bonded to the thiol, disulfide, polysulfide, or thioester moiety through a linking moiety and at least one heteroatom-containing divalent moiety selected from the group consisting of imine, amine, amide, imide, ether, and ester moiety.

20. The process of claim 19 , wherein the mixing further comprises:

pre-mixing or pre-modifying the component (ii) with component (iii).

21. The process of claim 19 , further comprising:

adding one or more methylene donor agents to the rubber composition.

22. The process of claim 19 , further comprising:

forming a rubber product from the rubber composition, wherein the rubber product is selected from the group consisting of a tire or tire component, a hose, a power belt, a conveyor belt, a printing roll, a rubber wringer, a ball mill liner, and combinations thereof.

23. The process of claim 19 , wherein the phenolic resin is a monohydric- or dihydric-phenolic-aldehyde resin, optionally modified by a naturally-derived organic compound containing at least one unsaturated bond.

24. The process of claim 19 , wherein the organosulfur compound is a thiol, disulfide, or thioester compound, having at least one functionalization connected to the thiol, disulfide, or thioester moiety through a linking moiety and an imine or ester moiety.

25. The process of claim 19 , wherein the mixing results in an interaction between the component (i) and the components (ii) and (iii) to reduce the hysteresis increase, caused in the rubber composition when a phenolic resin is added to the rubber composition, compared to a rubber composition without the component (iii).

26. The process of claim 25 , further comprising:

curing (vulcanizing) the rubber composition to further reduce the hysteresis increase.