Nanocomposite comprising a layer silicate and a rubber

Patent metadata

Field	Value
Publication number	US-2018319951-A1
Application number	US-201615773802-A
Country	US
Kind code	A1
Filing date	Nov 4, 2016
Priority date	Nov 6, 2015
Publication date	Nov 8, 2018
Grant date	—

Abstract

The invention relates to specific nanocomposites comprising at least one sheet silicate and at least one rubber, to a process for production thereof and to various products based on these nanocomposites.

First claim

1 . Nanocomposites of sheet silicate particles encased by a rubber matrix, wherein the nanocomposites comprise:
≤6 vol % of at least one sheet silicate, and at least one rubber from the group of natural rubber, ethylene-propylene-diene rubbers, ethylene-vinyl acetate rubbers, ethylene-acrylate rubbers, acrylate rubbers, fluoro rubbers, styrene/diolefin rubbers, polychloroprenes, polybutadiene rubbers, polylsoprenes, butyl rubber, halobutyl rubbers, nitrile rubbers, carboxylated nitrile rubbers, hydrogenated nitrile rubbers, and carboxylated hydrogenated nitrile rubbers, and 50% of the sheet silicate particles in the rubber matrix have a maximum median particle size d 50 of 100 to 200 nm.

2 . The nanocomposites as claimed in claim 1 , wherein the nanocomposites have a mean particle surface area of 20 to 30 m 2 /cm 3 .

3 . The nanocomposites as claimed in claim 1 , wherein the nanocomposites have an aspect ratio of more than 50, where the aspect ratio is the ratio of the longitudinal extent of a nanocomposite particle to its thickness.

4 . The nanocomposites as claimed in claim 1 , wherein the nanocomposites have an exfoliation level of 30% to 99%.

5 . The nanocomposites as claimed in claim 1 , wherein the sheet silicate therein has a contact area of 20 to 50 g/m 3 .

6 . A latex comprising an aqueous suspension of the nanocomposites as claimed in claim 1 .

7 . Products, in the form of rubber mixtures, vulcanizates or elastomers, comprising the at least one nanocomposite as claimed in claim 1 in a base polymer or vulcanizate.

8 . The products as claimed in claim 7 , wherein the content of nanocomposite in the base polymer or vulcanizate is 0.1% to 10% by mass.

9 . The products claimed in claim 7 , wherein the base polymers or vulcanizates are the same rubbers as the rubbers in the nanocomposites.

10 . The products as claimed in claim 9 , wherein:
the rubbers in the base polymer or in the vulcanizate are selected from the group of natural rubber, ethylene-propylene-diene rubbers, ethylene-vinyl acetate rubbers, ethylene-acrylate rubbers, acrylate rubbers, fluoro rubbers, styrene/diolefin rubbers, polychloroprenes, polybutadiene rubbers, polylsoprenes, butyl rubber, halobutyl rubbers, nitrile rubbers, hydrogenated nitrile rubbers, and carboxylated butadiene/acrylonitrile rubber; and the products are products used for sealing of liquid media or gaseous media in the chemical industry, the domestic appliance industry or the motor vehicle industry, and the products comprise gaskets, membranes, gas pressure accumulators, hoses, housings for motors, pumps and electrically operated tools, rollers, tires, couplings, buffer stops, conveyor belts, drive belts, multilayer laminates or multilayer films, and sound- and vibration-dampening components.

11 . A process for producing nanocomposites, the process comprising:
a) introducing a sheet silicate raw material comprising layers of silicate platelets into an aqueous medium to open up the layers of the silicate platelets, b) mixing the opened-up silicate platelet layers with at least one latex to form a first mixture, c) introducing the first mixture into a flow reactor and converting the mixture to a laminar extensional flow to further or completely separate the silicate platelets from one another, d) admixing and mixing:
the first mixture having further or completely separated silicate platelets present therein, and
a coagulant based on at least one add or at/east one salt,
in at least one mixing unit for coagulation of latex coated platelets to form an intermediate, and
e) collecting and isolating the intermediate in an alkaline, aqueous medium, wherein the latex comprises at least one rubber from the group of natural rubber, ethylene-propylene-diene rubbers, styrene/diolefin rubber, polybutadiene rubber, polychloroprene, polyisoprene, butyl rubber, halobutyl rubber, nitrile rubber, carboxylated nitrile rubber, hydrogenated nitrile rubber, and carboxylated hydrogenated nitrile rubber, and the mixing units are mixing nozzles or precipitation nozzles.

12 . The process as claimed in claim 11 , wherein the flow reactor has the configuration of a conically tapering tube.

13 . The process as claimed in claim 11 , wherein the conversion to a laminar extensional flow in the flow reactor is effected at a pressure of 0.2 to 30 bar.

14 . The process as claimed in claim 12 , wherein the conically tapering tube has an angle θ* of 1 to 15°, where the angle θ* indicates the slope angle of the flow reactor.

15 . The process as claimed in claim 12 , wherein the conically tapering tube has a narrowing factor D o /D 1 of 1.1 to 20, where D 0 is the cross section of the conically tapering tube on commencement of the onset of extensional flow and D 1 is the cross section of the conically tapering tube prior to entry of the extensional flow into the at least one mixing unit.

16 . The process as claimed in claim 15 , wherein the conically tapering tube has a length L and generates an approximately hyperbolic flow profile in the laminar extensional flow over its length L.

17 . The process as claimed in claim 12 , wherein the approximately hyperbolic flow profile is a smooth hyperbolic profile of the laminar flow, without steps.

18 . The process as claimed in claim 16 , wherein a ratio L/D 1 is 100 to 400.

19 . The process as claimed in claim 15 , wherein:
the mixture is moved through the reactor and into the mixinc unit at an applied pressure p, a ratio of diameter D 1 to pressure p controls the extensional flow, the throughput, and the volume flow rates in the mixing unit for the coagulation, and the ratio D 1 /p is 10-20/1-2.

20 . The process as claimed in claim 11 , wherein the at least one mixing unit comprises a mixing unit that works either by the external mixing principle, or by the internal mixing principle.

21 . The process as claimed in claim 20 , wherein the mixing unit comprises a mixing nozzle in which the coagulant is added into the laminar extensional flow by the internal mixing principle at right angles or obliquely relative to the laminar extensional flow in the flow reactor or after exit from the flow reactor.

22 . The process as claimed in claim 21 , wherein the coagulant is added into the extensional flow via three substreams, one at each of three points at a separation of 120° from one another.

23 . The process as claimed in claim 22 , wherein the three substreams of the coagulant are added to the extensional flow in the same cross section of the mixing nozzle.

24 . The process as claimed in claim 21 , wherein the feed rate of the coagulant relative to the extensional flow rate in the mixing nozzle is in a ratio of 1:100.

25 .- 29 . (canceled)

30 . A method for increasing the resistance of robber-based products or vulcanizates in the event of a sudden pressure drop, the method comprising producing the rubber-based products or vulcanizates from rubber comprising the nanocomposites as claimed in claim 1 .

Assignees

• Arlanxeo Deutschland Gmbh

Inventors

• Fruh Thomas
• Gottlieb Nadine
• Lucassen Alex
• Bischoff Andreas
• Schuster Robert Hans
• Schellenberg Marion

Classifications

• C08K3/346 Primary

  Clay · CPC title

• C08K2201/005

  Additives being defined by their particle size in general · CPC title

• C08K9/04

  Ingredients treated with organic substances {(treated with macromolecular compounds C08K9/08)} · CPC title

• C08K2201/011

  Nanostructured additives · CPC title

• C08K3/04

  Carbon · CPC title