Composition comprising silver nanowires in an alcohol/water mixture and dispersed styrene/(meth)acrylic copolymers for the preparation of electroconductive transparent layers

Patent metadata

Field	Value
Publication number	US-10526501-B2
Application number	US-201615564779-A
Country	US
Kind code	B2
Filing date	Mar 21, 2016
Priority date	Apr 9, 2015
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

Described is a composition suitable for the preparation of an electroconductive transparent layer, said composition comprising a mixture of water and one or more alcohols, electroconductive nanoobjects and one or more dissolved styrene/(meth)acrylic copolymers.

First claim

The invention claimed is:

1. A composition, comprising:
(A) a mixture comprising, based on a total volume of the mixture:
(A-1) 70-98 vol % of water, and
(A-2) 2-30 vol % of one or more alcohols selected from the group consisting of methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol and t-butanol,

(B) electroconductive nanoobjects, said electroconductive nanoobjects (B) having two external dimensions ranging from 1 nm to 100 nm and a third external dimension ranging from 1 μm to 100 μm, wherein a total weight fraction of said electroconductive nanoobjects (B) ranges from 0.01 wt.-% to 1 wt.-% based on a total weight of the composition, and
(C) dissolved in mixture (A), one or more styrene/(meth)acrylic copolymers, said dissolved copolymers (C) each having a number average molecular weight ranging from 500 g/mol to 22000 g/mol, wherein a total weight fraction of said dissolved copolymers (C) ranges from 0.02 wt.-% to 5 wt.-%, based on the total weight of the composition,
wherein the composition comprises 5 wt. % or less, based on the total weight of the composition, of constituents which at 25° C. and 101.325 kPa are solid, and
wherein the composition does not comprise carbon nanotubes.

2. The composition according to claim 1 , wherein said electroconductive nanoobjects (B) have
a length ranging from 1 μm to 100 μm, and
a diameter ranging from 1 nm to 100 nm,
wherein said electroconductive nanoobjects (B) comprise one or more materials selected from the group consisting of silver, copper, and gold.

3. The composition according to claim 1 , wherein said electroconductive nanoobjects (B) are selected from the group consisting of nanowires and nanotubes.

4. The composition according to claim 1 , wherein the ratio between the total weight of said electroconductive nanoobjects (B) and the total weight of said dissolved copolymers (C) ranges from 1:20 to 20:1.

5. The composition according to claim 1 , wherein the one or more alcohols (A-2) are selected from the group consisting of i-propanol, n-butanol and t-butanol.

6. The composition according to claim 1 , comprising
(A) the mixture,
(B) silver nanowires as the electroconductive nanoobjects, said silver nanowires (B) having a length ranging from 10 μm to 50 μm and a diameter ranging from 3 nm to 30 nm, wherein a total weight fraction of said silver nanowires (B) is 0.5 wt.-% or less, based on the total weight of the composition, and
(C) dissolved in mixture (A), a styrene/(meth)acrylic copolymer,
said dissolved copolymer (C) having a number average molecular weight ranging from 1700 g/mol to 15500 g/mol, wherein a weight fraction of said dissolved copolymer (C) is less than 2 wt.-%, based on the total weight of the composition,

wherein a ratio between the total weight of said silver nanowires (B) and the weight of said dissolved copolymer (C) ranges from 1:5 to 5:1.

7. The composition according to claim 1 , wherein the mixture consists of:
(A-1) 75-85 vol % of the water,
(A-2) 15-25 vol % of the one or more alcohols selected from the group consisting of methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol and t-butanol.

8. A method for preparing an electroconductive layer having a light transmission of 80% or more measured according to ASTM D1003 (procedure A) as published in November 2013 on a substrate, the method comprising:
preparing or providing the composition according to claim 1 ,
applying said composition to a surface of a substrate, and
removing the constituents which at 25° C. and 101.325 kPa are liquid from said composition to such extent that a layer is formed on said surface of said substrate.

9. The method according to claim 8 , wherein said applying is carried out by a technique selected from the group consisting of spin coating, draw down coating, roll-to-roll coating, gravure printing, microgravure printing, screen-printing, flexoprinting and slot-die coating.

10. The method according to claim 8 , wherein said substrate comprises a material selected from the group consisting of glass and an organic polymer.

11. The method according to claim 8 , wherein said substrate comprises polyethylene terephthalate.

12. The method according to claim 9 , wherein said removing is achieved by subjecting said composition applied to said surface of said substrate to a temperature ranging from 100° C. to 150° C. for a duration of 15 minutes or less.

Assignees

• Basf Se

Inventors

• Dietsch Herve
• Sturm Thomas
• Seyfried Danny
• Zhang Rui

Classifications

• C08K2003/0831

  Gold · CPC title

• C08K7/04

  inorganic · CPC title

• C08K3/046

  Carbon nanorods, nanowires, nanoplatelets or nanofibres · CPC title

• C09D11/033

  characterised by the solvent · CPC title

• C08K3/041

  Carbon nanotubes · CPC title