Microbeads comprising silicate fibres with needle-shaped morphology of nanometric size, preparation thereof, elastomeric compositions and tyres for vehicles comprising them

Patent metadata

Field	Value
Publication number	US-2020299482-A1
Application number	US-201816765677-A
Country	US
Kind code	A1
Filing date	Nov 28, 2018
Priority date	Nov 29, 2017
Publication date	Sep 24, 2020
Grant date	—

Abstract

Microbeads are described, comprising silica fibres with needle-shaped morphology of nanometric size, characterised by reduced dustiness and good dispersibility in elastomeric materials, a process for the preparation thereof and the use thereof in the production of vehicle tyres.

First claim

1 - 23 . (canceled)

24 . A microbead having an average diameter of at least 50 microns, comprising:
A silica, and B silicate fibres with needle-shaped morphology of nanometric size, wherein the silica A and the silicate fibres B are present in a weight ratio of A to B ranging from 0.5:1 to 15:1 and in a total amount of A+B of at least 90% by weight of the microbead when dry.

25 . The microbead according to claim 24 , wherein the average diameter is at least 60, at least 70, or at least 80 microns.

26 . The microbead according to claim 24 , wherein the weight ratio of A to B ranges from 0.7:1 to 10:1, from 0.7:1 to 5:1, from 0.8:1 to 3:1, from 0.9:1 to 2.5:1, or from 0.9:1 to 1.1:1.

27 . The microbead according to claim 24 , wherein the silica A is a precipitated amorphous silica.

28 . The microbead according to claim 24 , wherein the silicate fibres B are chosen from fibres of sepiolite, fibres of palygorskite, fibres of wollastonite, fibres of imogolite, and said fibres when modified, and mixtures thereof.

29 . The microbead according to claim 28 , wherein the silicate fibres B are fibres of sepiolite modified by acid treatment or surface deposition of amorphous silica or derivatization with quaternary ammonium salts.

30 . The microbead according to claim 24 , wherein the silicate fibres B are present in an amount of at least 5% or at least 10% by weight of the microbead when dry.

31 . The microbead according to claim 24 , wherein:
the silicate fibres B are sepiolite fibres or modified sepiolite fibres, the weight ratio of A to B ranges from 0.9:1 to 1.1, and the average diameter of the microbead is at least 70 microns.

32 . The microbead according to claim 24 , prepared by a process comprising:
providing an aqueous suspension comprising the silica A and the silicate fibres B in a weight ratio of A to B ranging from 0.5:1 to 15:1, from 0.7:1 to 10:1, or from 0.7:1 to 5:1, and in a total amount of A+B of at least 5% (w/w) of the suspension, and drying the aqueous suspension by nebulisation.

33 . A process for preparing a microbead comprising silica A and silicate fibres with needle-shaped morphology of nanometric size B comprising:
providing an aqueous suspension comprising the silica A and the silicate fibres B in a weight ratio of A to B ranging from 0.5:1 to 15:1, from 0.7:1 to 10:1, or from 0.7:1 to 5:1, and in a total amount of A+B of at least 5% (w/w) or at least 10% (w/w) of the suspension, and drying the aqueous suspension by nebulisation.

34 . The process according to claim 33 , wherein a liquid phase of the aqueous suspension comprises at least 80%, at least 90%, or at least 95% (w/w) water.

35 . The process according to claim 33 , wherein the aqueous suspension comprising the silica A and the silicate fibres B is prepared starting from wet filtration cakes of silica A and silicate fibres B.

36 . A vulcanisable elastomeric composition for tyre components, comprising:
(a) 100 phr of at least one diene elastomer, (b) 2 to 110 phr of microbeads, (c) 0 to 120 phr of a standard reinforcing filler, (d) 0.1 to 15 phr of a vulcanising agent, and (e) 0.1 to 20 phr of a coupling agent; wherein the microbeads have an average diameter of at least 50 microns and comprise
A silica, and
B silicate fibres with needle-shaped morphology of nanometric size,
wherein the silica A and the silicate fibres B are present in a weight ratio of A to B ranging from 0.5:1 to 15:1 and in a total amount of A+B of at least 90% by weight of the microbeads when dry.

37 . The elastomeric composition according to claim 36 , wherein the silicate fibres B are present in an amount greater than 15 phr or of at least 20 phr, at least 25 phr, or at least 30 phr.

38 . The elastomeric composition according to claim 36 , comprising silica as the standard reinforcing filler (c) in an amount less than 25 phr or not exceeding 15 phr.

39 . The elastomeric composition according to claim 36 , wherein a weight ratio of total silica in the composition to silicate fibres B is less than 2.7:1, less than 1.8:1, or 1:1 or less.

40 . The elastomeric composition according to claim 36 , wherein
the diene elastomer (a) is chosen from natural or synthetic 1,4-polyisoprene, 3,4-polyisoprene, polybutadiene, halogenated isoprene/isobutene copolymers, nonhalogenated isoprene/isobutene copolymers, 1,3-butadiene/acrylonitrile copolymers, styrene/1,3-butadiene copolymers, styrene/isoprene/1,3-butadiene copolymers, styrene/1,3-butadiene/acrylonitrile copolymers, and mixtures thereof; the standard reinforcing filler (c) is chosen from carbon black, precipitated amorphous silica, amorphous silica of natural origin, calcium carbonate, titanium dioxide, talc, alumina, kaolin, and mixtures thereof; the vulcanising agent (d) is chosen from (i) soluble sulphur (crystalline sulphur), (ii) insoluble sulphur (polymer sulphur), (iii) oil-dispersed sulphur, and (iv) sulphur donors; and the coupling agent (e) is a silane coupling agent having at least one hydrolysable silane group.

41 . A vulcanisable or vulcanised elastomeric compound prepared by a process comprising mixing or mixing and vulcanizing an elastomeric composition comprising:
(a) 100 phr of at least one diene elastomer, (b) 2 to 110 phr of microbeads, (c) 0 to 120 phr of a standard reinforcing filler, (d) 0.1 to 15 phr of a vulcanising agent, and (e) 0.1 to 20 phr of a coupling agent; wherein the microbeads have an average diameter of at least 50 microns and comprise
A silica, and
B silicate fibres with needle-shaped morphology of nanometric size,
wherein the silica A and the silicate fibres B are present in a weight ratio of A to B ranging from 0.5:1 to 15:1 and in a total amount of A+B of at least 90% by weight of the microbeads when dry.

42 . A tyre component comprising a vulcanised elastomeric composition comprising:
(a) 100 phr of at least one diene elastomer, (b) 2 to 110 phr of microbeads, (c) 0 to 120 phr of a standard reinforcing filler, (d) 0.1 to 15 phr of a vulcanising agent, and (e) 0.1 to 20 phr of a coupling agent; wherein the microbeads have an average diameter of at least 50 microns and comprise
A silica, and
B silicate fibres with needle-shaped morphology of nanometric size,
wherein the silica A and the silicate fibres B are present in a weight ratio of A to B ranging from 0.5:1 to 15:1 and in a total amount of A +B of at least 90% by weight of the microbeads when dry.

43 . The tyre component according to claim 42 , wherein the tyre component is chosen from tread, under-layer, anti-abrasive strip, sidewall, sidewall insert, mini-sidewall, under-liner, rubber layers, bead filler, and sheet.

44 . A tyre for vehicle wheels comprising at least one component, wherein the at least one component comprises a vulcanised elastomeric composition comprising:
(a) 100 phr of at least one diene elastomer, (b) 2 to 110 phr of microbeads, (c) 0 to 120 phr of a standard reinforcing filler, (d) 0.1 to 15 phr of a vulcanising agent, and (e) 0.1 to 20 phr of a coupling agent; wherein the microbeads have an average diameter of at least 50 microns and comprise
A silica, and
B silicate fibres with needle-shaped morphology of nanometric size,
wherein the silica A and the silicate fibres B are present in a weight ratio of A to B ranging from 0.5:1 to 15:1 and in a total amount of A+B of at least 90% by weight of the microbeads when dry.

45 . The tyre according to cla

Assignees

• Pirelli

Inventors

• Giannini Luca
• Tadiello Luciano
• Hanel Thomas
• Perez Cacho Jorge
• Julve Sebastian Daniel Javier

Classifications

• C08K9/02 Primary

  Ingredients treated with inorganic substances · CPC title

• C08K2201/003

  Additives being defined by their diameter · CPC title

• B60C1/00

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

• C08K7/10

  Silicon-containing compounds · CPC title

• C08K3/346

  Clay · CPC title