Silica Masterbatch Made with Emulsion and Solution Rubber

• US 20190322841A1
• Filed: 07/02/2019
• Published: 10/24/2019
• Est. Priority Date: 03/07/2014
• Status: Active Grant

• Current Assignee: Industrias Negromex S.A. de C.V. (Grupo Kuo, S.A.B. De C.V.)
• Original Assignee: Industrias Negromex S.A. de C.V. (Grupo Kuo, S.A.B. De C.V.)
• Inventors: Hardiman, Christopher J., Fu, Xuan, Scribner, Robert J., Maldonado Valenzuela, Julian
• Granted Patent: US 11,180,639 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 3/38 Steam distillation
• CPC Class Codes: C08F 2/44 Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
• CPC Class Codes: C08F 6/10 Removal of volatile materials, e.g. solvents C08F6/001, C08F6/003, C08F6/005, C08F6/006, C08F6/008, C08F6/02, C08F6/04 take precedence
• CPC Class Codes: C08J 2321/02 Latex
• CPC Class Codes: C08J 3/16 by coagulating dispersions C08J3/122 takes precedence
• CPC Class Codes: C08J 3/22 using masterbatch techniques
• CPC Class Codes: C08K 9/00 Use of pretreated ingredients
• CPC Class Codes: C08K 9/04 Ingredients treated with organic substances treated with macromolecular compounds C08K9/08
• CPC Class Codes: C08K 9/06 with silicon-containing compounds
• CPC Class Codes: C08L 21/00 Compositions of unspecified rubbers
• CPC Class Codes: C08L 21/02 Latex
• CPC Class Codes: C08L 2310/00 Masterbatches
• CPC Class Codes: C08L 2314/00 Polymer mixtures characterised by way of preparation

Abstract

The present invention provides a process for making a silica masterbatch that contains hydrophobated silica, solution-made rubber and emulsion-made rubber. Hydrophobated silica is mixed into a latex emulsion. Solution-rubber crumb in an aqueous suspension is mixed into the latex emulsion, which is coagulated, and a crumb is recovered, further homogenized, dried and baled to yield the silica masterbatch. A well-dispersed mixture of hydrophobated silica and emulsion-made rubber is added into a steam distillation step of a solution-rubber process from which a silica masterbatch is recovered. The emulsion-made rubber can be omitted to make a silica masterbatch of solution rubber and silica without emulsion rubber. The silica masterbatch has physical properties similar to those found in a comparable dry-mixed composition, but the silica masterbatch can be incorporated more easily and less expensively into tires and other rubber products than the dry-mixed composition.

Claims

1. A process for making silica-filled solution rubber, comprising the steps of:

hydrophobating silica with a coupling agent that bonds to the silica and provides a site for bonding to rubber;

mixing the hydrophobated silica into a process oil;

making a solution rubber stream comprising solution rubber in an organic solvent;

feeding the solution rubber stream to a steam distillation unit;

feeding the mixture of hydrophobated silica and process oil to the steam distillation unit;

operating the steam distillation unit; and

recovering a silica-filled solution-made rubber that comprises the solution rubber and the hydrophobated silica.

2. The process of claim 1, wherein the coupling agent is selected from the group consisting of:

bis-(3-trimethoxysilylpropyl)-disulfide (TMSPD), bis-(3-trimethoxysilylpropyl)-tetrasulfide (TMSPT), 3-mercaptopropyl trimethoxy silane, bis-(3-triethoxysilylpropyl)-disulfide (TESPD), bis-(3-triethoxysilylpropyl)-tetrasulfide (TESPT), 3-mercaptopropyl triethoxy silane and mixtures thereof.

3. The process of claim 1, wherein the solution rubber comprises a blend of styrene-butadiene rubber and polybutadiene rubber, wherein the polybutadiene rubber is synthesized with a lithium-based catalyst system.

4. The process of claim 1, wherein the solution rubber comprises a blend of styrene-butadiene rubber and polybutadiene rubber, wherein the polybutadiene rubber is synthesized with a neodymium-based catalyst system.

5. The process of claim 1, further comprising feeding a dispersant and a coagulant to the steam distillation unit.

6. The process of claim 5, wherein the silica-filled solution-made rubber contains less than 1 wt % extender oil, and wherein the silica-filled solution-made rubber has an average particle size of no more than about 3 mm.

7. A process for making a silica masterbatch, comprising the steps of:

operating an emulsion rubber plant;

receiving the silica-filled solution-made rubber of claim 1 at the emulsion rubber plant;

making a polymer latex;

mixing the silica-filled solution-made rubber into the polymer latex to form a latex mixture;

mixing a coagulating agent into the latex mixture to form a coagulated mixture; and

recovering the silica masterbatch from the coagulated mixture.

8. A process for making a silica masterbatch, comprising the steps of:

operating an emulsion rubber plant;

receiving the silica-filled solution-made rubber of claim 2 at the emulsion rubber plant;

making a polymer latex;

mixing the silica-filled solution-made rubber into the polymer latex to form a latex mixture;

mixing a coagulating agent into the latex mixture to form a coagulated mixture; and

recovering the silica masterbatch from the coagulated mixture.

9. A process for making a silica masterbatch, comprising the steps of:

operating an emulsion rubber plant;

receiving the silica-filled solution-made rubber of claim 3 at the emulsion rubber plant;

making a polymer latex;

mixing the silica-filled solution-made rubber into the polymer latex to form a latex mixture;

mixing a coagulating agent into the latex mixture to form a coagulated mixture; and

recovering the silica masterbatch from the coagulated mixture.

10. A process for making a silica masterbatch, comprising the steps of:

operating an emulsion rubber plant;

receiving the silica-filled solution-made rubber of claim 4 at the emulsion rubber plant;

making a polymer latex;

mixing the silica-filled solution-made rubber into the polymer latex to form a latex mixture;

mixing a coagulating agent into the latex mixture to form a coagulated mixture; and

recovering the silica masterbatch from the coagulated mixture.

11. The process of claim 7, wherein the silica-filled solution-made rubber is not dried prior to receipt at the emulsion rubber plant, and wherein the silica-filled solution-made rubber is received in the form of rubber particles suspended in water or as a wet crumb.

12. A process for making a silica masterbatch, comprising the steps of:

(a) hydrophobating silica;

(b) receiving solution-made rubber crumb particles, wherein the solution-made rubber crumb particles were made in a solution process for making rubber;

(c) making a polymer latex;

(d) mixing the hydrophobated silica and the solution-made rubber crumb particles into the polymer latex;

(e) coagulating the polymer latex from step (d); and

(f) recovering a silica-filled rubber that comprises a mixture of silica, emulsion-made rubber and solution-made rubber.

13. The process of claim 12, wherein the silica is hydrophobated by

(i) dissolving a trimethoxy silane coupling agent in a mixture of alcohol, a weak acid and water to provide a trimethoxy silane coupling agent solution that contains at least about 75% water by weight, and

(ii) mixing the trimethoxy silane coupling agent solution with silica and adding a base to increase the pH to form the hydrophobated silica.

14. The process of claim 13, wherein the trimethoxy silane coupling agent is 3-mercaptopropyl trimethoxy silane, bis-(3-trimethoxysilylpropyl)-disulfide and/or bis-(3-trimethoxysilylpropyl)-tetrasulfide.

15. The process of claim 12, wherein an ethoxysilane is used to hydrophobate the silica.

16. The process of claim 12, wherein a triethoxy silane coupling agent is used to hydrophobate the silica.

17. The process of claim 12, wherein a triethoxy silane coupling agent is used to hydrophobate the silica, and wherein the triethoxy silane coupling agent is 3-mercaptopropyl triethoxy silane, bis-(3-triethoxysilylpropyl)-disulfide and/or bis-(3-triethoxysilylpropyl)-tetrasulfide.

18. The process of claim 12, wherein the solution-made rubber crumb particles are received in the form of rubber particles suspended in water or as a wet crumb, wherein the particles and the wet crumb have an average particle size of no more than about 3 mm, and wherein the solution-made rubber crumb particles contain less than 5 wt % extender oil.

19. The process of claim 12, further comprising mixing a process oil into the polymer latex to provide 25-50 phr of process oil in the silica-filled rubber.

20. A process for making a silica masterbatch, comprising the steps of:

making, obtaining or preparing a solution-made rubber stream having from about 5% to about 50% solids by weight in an organic solvent;

receiving a suspension of emulsion-made rubber particles in water, wherein the emulsion-made rubber particles contain silica dispersed within the particles;

feeding the solution-made rubber stream and the suspension of emulsion-made rubber particles to a steam distillation unit;

operating the steam distillation unit; and

recovering a silica-filled rubber that comprises solution-made rubber, emulsion-made rubber and silica.

21. The process of claim 20, further comprising adding a dispersant and a coagulant into the steam distillation unit.

22. The process of claim 21, wherein an aqueous stream is added to the steam distillation unit, and wherein the dispersant and the coagulant are in the aqueous stream.

23. The process of claim 20, further comprising adding a dispersant and a coagulant into the suspension of emulsion-made rubber particles in water.

24. The process of claim 20, wherein the silica has a BET surface area of between about 200 and about 400 m²/g.

25. The process of claim 20, wherein the solution-made rubber stream contains from about 10% to about 25% solids by weight.

26. The process of claim 20, further comprising adding a dispersant and a coagulant into the steam distillation unit,

wherein the steam distillation unit comprises a distillation column having an upper end and a lower end, wherein the lower end includes a reservoir for holding a liquid, wherein the liquid or the reservoir is heated,

wherein the solution-made rubber stream is fed into the upper end of the distillation column, wherein the suspension of emulsion-made rubber particles is fed into the reservoir, wherein the organic solvent is recovered from the upper end, wherein the silica-filled rubber is recovered from the lower end as particles suspended in an aqueous solution, and

further comprising separating the particles from the aqueous solution.

27. The process of claim 20, wherein the solution-made rubber stream is prepared by dissolving dry solution-made rubber in the organic solvent.

28. The process of claim 20, wherein the solution-made rubber stream comprises a solution-made rubber selected from the group consisting of styrene-butadiene rubber, natural rubber, neoprene rubber, acrylonitrile butadiene rubber, polybutadiene rubber, vinyl pyridine butadiene rubber, styrene butadiene termonomer rubber, EPDM, chloroprene, HNBR and SBS.

29. The process of claim 28, wherein the solution-made rubber comprises more than one rubber.

30. The process of claim 20, wherein the solution-made rubber stream comprises a blend of styrene-butadiene rubber and polybutadiene rubber, wherein the polybutadiene rubber is synthesized with a lithium-based catalyst system.

31. The process of claim 20, wherein the solution-made rubber stream comprises a blend of styrene-butadiene rubber and polybutadiene rubber, wherein the polybutadiene rubber is synthesized with a neodymium-based catalyst system.

32. The process of claim 20, wherein the silica is hydrophobated using a trimethoxy silane coupling agent.

33. The process of claim 32, wherein the trimethoxy silane coupling agent is bis-(3-trimethoxysilylpropyl)-disulfide, bis-(3-trimethoxy-silylpropyl)-tetrasulfide and/or 3-mercaptopropyl trimethoxy silane.

34. The process of claim 20, wherein the silica is hydrophobated using a triethoxy silane coupling agent.

35. The process of claim 34, wherein the triethoxy silane coupling agent is bis-(3-triethoxysilylpropyl)-disulfide, bis-(3-triethoxy-silylpropyl)-tetrasulfide and/or 3-mercaptopropyl triethoxy silane.

36. A process for making a silica masterbatch, comprising the steps of:

(a) hydrophobating silica and forming a compatibilized silica slurry;

(b) making a polymer latex using a process for making an emulsion-made rubber;

(c) mixing the compatibilized silica slurry into the polymer latex;

(d) coagulating the polymer latex from step (c); and

(e) recovering a first silica-filled rubber, wherein either

(i) solution-made rubber crumb particles are mixed into the polymer latex with the compatibilized silica slurry, wherein the solution-made rubber crumb particles are made in a solution process in which one or more monomers are polymerized in an organic solvent and coagulated to form the solution-made rubber crumb particles, and wherein the first silica-filled rubber is the silica masterbatch, or

(ii) the first silica-filled rubber is added into a process for making a solution-rubber to make a second silica-filled rubber, wherein the second silica-filled rubber is the silica masterbatch, and

wherein the silica masterbatch comprises a mixture of silica, emulsion-made rubber and solution-made rubber.

37. The process of claim 36, wherein the silica has a BET surface area of between about 200 and about 400 m²/g.

38. The process of claim 36, wherein the polymer latex is made from monomers for making a rubber selected from the group consisting of styrene-butadiene rubber, natural rubber, neoprene rubber, acrylonitrile butadiene rubber, polybutadiene rubber, EPDM, chloroprene, HNBR, SBS, vinyl pyridine butadiene rubber and styrene butadiene termonomer rubber, and wherein the termonomer is selected from the group consisting of hydroxyalkyl acrylate, vinyl pyridine and acrylonitrile.

39. The process of claim 36, wherein calcium chloride is used as a coagulating agent for coagulating the polymer latex.

40. The process of claim 36, wherein the solution-made rubber crumb particles are mixed into the polymer latex with the compatibillized silica slurry, and wherein the solution-made rubber crumb particles have a diameter between about 0.5 and about 3.0 mm.

41. The process of claim 40, further comprising adding a process oil into the latex before the latex is coagulated, wherein an amount of process oil is added so that the silica masterbatch contains between about 15 and about 50 parts of process oil per 100 parts of rubber in the silica masterbatch.

42. The process of claim 41, wherein the solution-made rubber crumb particles contain less than 1 wt % extender oil, and wherein the process oil is selected from the group consisting of highly aromatic oil, aromatic oil (AO), treated distillate aromatic extract (TDAE), residual aromatic extract (RAE), mildly extracted solvate (MES), naphthenic oil, hydroprocessed naphthenic oil (HNO) and paraffinic oil.

43. The process of claim 36, wherein the solution-made rubber crumb particles are received in the form of rubber particles suspended in water or as a wet crumb.

44. The process of claim 36, wherein the solution-made rubber crumb particles are mixed into the polymer latex with the compatibillized silica slurry, further comprising obtaining the solution-made rubber crumb particles in the form of dry particles;

dissolving the dry particles in an organic solvent to yield a solution that contains from about 10 to about 35 wt % solution-made rubber;

adding a dispersant and a coagulant to the solution; and

steam distilling the solution.

45. The process of claim 36, wherein the first silica-filled rubber is added into a solution-rubber process to make the second silica-filled rubber, wherein the solution-rubber process includes a steam distillation step, and wherein the first silica-filled rubber is added into the steam distillation step.

46. The process of claim 45, wherein the silica has a BET surface area of between about 200 and about 400 m²/g, further comprising adding a dispersant and a coagulant into the steam distillation step.

47. The process of claim 36, wherein the silica is hydrophobated by

(i) dissolving a trimethoxy silane coupling agent in a mixture of alcohol, a weak acid and water to provide a trimethoxy silane coupling agent solution that contains at least about 75% water by weight, and

(ii) mixing the trimethoxy silane coupling agent solution with silica and adding a base to increase the pH to form the hydrophobated silica.

48. The process of claim 47, wherein the trimethoxy silane coupling agent is 3-mercaptopropyl trimethoxy silane, bis-(3-trimethoxysilylpropyl)-disulfide and/or bis-(3-trimethoxysilylpropyl)-tetrasulfide.

49. The process of claim 36, wherein an ethoxysilane is used to hydrophobate the silica.

50. The process of claim 36, wherein a triethoxy silane coupling agent is used to hydrophobate the silica.

51. The process of claim 36, wherein a triethoxy silane coupling agent is used to hydrophobate the silica, and wherein the triethoxy silane coupling agent is 3-mercaptopropyl triethoxy silane, bis-(3-triethoxysilylpropyl)-disulfide and/or bis-(3-triethoxysilylpropyl)-tetrasulfide.

52. The process of claim 36, wherein the solution-made rubber comprises a blend of styrene-butadiene rubber and polybutadiene rubber, wherein the polybutadiene rubber is synthesized with a lithium-based catalyst system.

53. The process of claim 36, wherein the solution-made rubber comprises a blend of styrene-butadiene rubber and polybutadiene rubber, wherein the polybutadiene rubber is synthesized with a neodymium-based catalyst system.