Tyre for vehicle wheels comprising a composite reinforcing filler

Patent metadata

Field	Value
Publication number	US-11390118-B2
Application number	US-201816645085-A
Country	US
Kind code	B2
Filing date	Sep 12, 2018
Priority date	Sep 13, 2017
Publication date	Jul 19, 2022
Grant date	Jul 19, 2022

Abstract

The invention relates to a tyre (100) for vehicle wheels comprising at least one structural element comprising a vulcanized elastomeric material obtained by vulcanizing a vulcanizable elastomeric composition comprising at least one vulcanizable diene elastomeric polymer and at least one composite reinforcing filler, a process for producing a tyre (100) comprising the composite reinforcing filler, a masterbatch comprising the composite reinforcing filler and a process for producing the same, as well as a process for producing the composite reinforcing filler.

First claim

The invention claimed is:

1. A tyre for vehicle wheels comprising at least one structural element comprising a vulcanized elastomeric material obtained by vulcanizing a vulcanizable elastomeric composition comprising:
(a) at least one vulcanizable diene elastomeric polymer; and
(b) at least one composite reinforcing filler comprising a core, and the core comprises nanocrystalline cellulose and an at least partial coating comprising silica.

2. The tyre according to claim 1 , wherein the composite reinforcing filler has a core-shell structure, and the core-shell structure comprises a core comprising nanocrystalline cellulose and a shell comprising silica.

3. The tyre according to claim 1 , wherein the composite reinforcing filler has a diameter ranging from 10 nm to 60 nm and a length ranging from 100 nm to 1000 nm.

4. The tyre according to claim 1 , wherein the composite reinforcing filler has a degree of crystallinity ranging from 10% to 80%.

5. The tyre according to claim 1 , wherein the composite reinforcing filler has a density ranging from 1.5 g/cm 3 to 1.9 g/cm 3 .

6. The tyre according to claim 1 , wherein the composite reinforcing filler has a BET total surface area ranging from 20 m 2 /g to 400 m 2 /g.

7. The tyre according to claim 1 , wherein the composite reinforcing filler comprises from 20% to 80% by weight of silica with respect to the total weight of the composite reinforcing filler.

8. The tyre according to claim 1 , wherein the vulcanizable elastomeric composition comprises from 0.1 phr to 40 phr of the composite reinforcing filler per 100 phr of vulcanizable diene elastomeric polymer.

9. The tyre according to claim 1 , wherein the structural element is chosen from a tread band, a carcass structure, a belt structure, an underlayer, an anti-abrasive strip, a sidewall, a sidewall insert, a mini-sidewall, a flipper, a chafer, an underliner, rubber layers, a bead filling, and rubber sheets.

10. A process for producing a tyre for vehicle wheels, comprising:
providing a vulcanizable elastomeric composition comprising:
(a) at least one vulcanizable diene elastomeric polymer; and
(b) at least one composite reinforcing filler comprising a core, and the core comprises nanocrystalline cellulose and an at least partial coating comprising silica;

providing a tyre structural element comprising the vulcanizable elastomeric composition;
assembling the tyre structural element in a green tyre; and
vulcanizing the green tyre.

11. The process according to claim 10 , wherein providing a vulcanizable elastomeric composition comprises:
feeding to at least one mixing apparatus comprising at least one discontinuous mixer and at least one continuous mixer, or at least one discontinuous mixer or at least one continuous mixer:the at least one vulcanizable diene elastomeric polymer, and the at least one composite reinforcing filler;
mixing and dispersing to obtain the vulcanizable elastomeric composition; and
discharging the vulcanizable elastomeric composition from the at least one mixing apparatus.

12. The process according to claim 11 , wherein the composite reinforcing filler is fed to the at least one mixing apparatus in the form of a masterbatch and the masterbatch comprises:
at least one vulcanizable diene elastomeric polymer; and
the composite reinforcing filler.

13. A masterbatch comprising:
(a) at least one vulcanizable diene elastomeric polymer; and
(b) at least one composite reinforcing filler comprising a core and the core comprises nanocrystalline cellulose and an at least partial coating comprising silica.

14. The masterbatch according to claim 13 , wherein the composite reinforcing filler has a core-shell structure, and the core-shell structure comprises a core comprising nanocrystalline cellulose and a shell comprising silica..

15. The masterbatch according to claim 13 , wherein the composite reinforcing filler is present in an amount from 5 phr to 120 phr per 100 phr of the vulcanizable diene elastomeric polymer.

16. A process for producing a masterbatch comprising:
(a) at least one vulcanizable diene elastomeric polymer; and
(b) at least one composite reinforcing filler comprising a core and the core comprises nanocrystalline cellulose and an at least partial coating comprising silica;
wherein the process comprises:
I. providing an aqueous dispersion of the composite reinforcing filler;
II. adding, by mixing, the aqueous dispersion of step I. to a latex and the latex comprises the vulcanizable diene elastomeric polymer;
III. coagulating the latex resulting from step II. to obtain a coagulated product comprising the composite reinforcing filler; and
IV. purifying the coagulated product resulting from step III.

17. The process according to claim 16 , wherein purifying the coagulated product comprises at least one operation chosen from filtering, washing, centrifuging, drying, and lyophilizing.

18. A process for producing a composite reinforcing filler comprising:
(A). dispersing a nanocrystalline cellulose at a temperature ranging from 70° C. to 90° C. in an aqueous dispersing medium in the presence of at least one surfactant chosen from cationic surfactants and amphoteric surfactants to obtain an aqueous dispersion comprising nanocrystalline cellulose;
(B). adding at least one silica precursor compound to the aqueous dispersion resulting from step (A);
(C). depositing an at least partial coating of silica on the nanocrystalline cellulose by hydrolyzing the silica precursor compound to obtain a composite reinforcing filler comprising a core and the core comprises nanocrystalline cellulose and an at least partial coating comprising silica; and
(D). purifying the composite reinforcing filler resulting from step (C).

19. The process according to claim 18 , wherein the surfactant is chosen from benzalkonium chloride, cetrimonium chloride, hexadecyltrimethylammonium bromide, undecyl amido propyl trimethylammonium metasulphate, and coco alkyl trimethylammonium metasulphate.

20. The process according to claim 18 , wherein the surfactant is added in an amount ranging from 10% to 20%, by weight with respect to the weight of the nanocrystalline cellulose.

21. The process according to claim 18 , wherein the silica precursor compound is chosen from:
I. alkaline silicates of the formula:
M 2 O·n(SiO 2 )   (I)

wherein M is chosen from Na, K, and Li and wherein n is ranging from 0.5 to 4, II. tetra-alkyl derivatives of silicic acid of the formula
(RO) 4 Si   (II)

wherein the R groups are the same or different from each other and represent C 1 -C 6 alkyls, and
III. halosilanes of the formula
SiX 4 , (RO) 3 SiX, (RO) 2 SiX 2 , or (RO)SiX 3   (III)

wherein the R groups are the same or different from each other and are chosen from C 1 -C 6 alkyls, and X are the same or different from each other and are chosen from chlorine, bromine, and iodine.

22. The process according to claim 21 , wherein the silica precursor compound is an alkaline silicate.

23. The process according to claim 22 , wherein in step (B) the addition is carried out while keeping the aqueous dispersion in a basic medium and at a temperature ranging from 70° C. to 90° C.

24. The process according to claim 22 , wherein the amount of alkaline silicate ranges from 50% to 150%, by weight with respect to the weight of the nanocrystalline cellulose.

25. The process according to claim 22 ,

Assignees

• Pirelli

Inventors

• Castellani Luca
• Zoia Luca
• Ali Syed Danish
• Orlandi Marco
• Hanel Thomas

Classifications

• C08K2201/003

  Additives being defined by their diameter · CPC title

• C08L2310/00

  Masterbatches · CPC title

• C08L7/00

  Compositions of natural rubber · CPC title

• C08B15/05

  Derivatives containing elements other than carbon, hydrogen, oxygen, halogens or sulfur (esters or phosphorous acids C08B5/00) · CPC title

• C08K2201/011

  Nanostructured additives · CPC title