Water-based conductive ink for rapid prototype in writable electronics

Patent metadata

Field	Value
Publication number	US-10442946-B2
Application number	US-201815901916-A
Country	US
Kind code	B2
Filing date	Feb 22, 2018
Priority date	Apr 3, 2017
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

The present application describes a composition and method thereof to make low cost environment friendly and highly safe conducive ink by using micro-sized silver particles, water, edible level thickener, water-based solvent, water-based resin and surfactant. The conductive ink may be written by various kinds of writing devices like gel pen, ball pen etc. on various substrates like paper, plastic, metal, etc. form a conductive trace. As additional features of the present application, the composition comprises erasable conductive ink, which is fast curing and conductive immediately upon application, having multiple applications for educational purpose to help students have a better understanding of how electronic work and even design their own electronics conveniently.

First claim

What is claimed is:

1. A composition for a conductive ink, comprising:
a solvent;
conductive particles free from any nanoparticles, wherein the conductive particles further comprise one or more metals;
an edible thickener;
a surfactant; and
water in the range of 30%-60% weight by weight of the composition, wherein said composition comprises a dispersant comprising a water-based resin having concentration in a range of 1% to less than 5% weight by weight of the composition wherein the water-based resin comprises one or more compounds selected from a group consisting of aldehyde ketone resin, epoxy, phenol-formaldehyde resin and polyvinylidene difluoride (PVDF), and wherein the water-based resin having the concentration in the range of 1% to less than 5% weight by weight of the composition makes the conductive ink erasable.

2. The composition of claim 1 , wherein the conductive particles comprise one or more particles selected from the group consisting of silver, copper, gold, carbon and any other conductive metal alloy particles.

3. The composition of claim 1 , wherein the conductive particles have a size in a range of 1 to 15 micrometers and are added at a concentration in a range of 15% to 50% weight by weight of the composition.

4. The composition of claim 1 , wherein the solvent is water-based and nontoxic, and wherein the solvent comprises a glycol selected from one of ethylene glycol, diethylene glycol, and triethylene glycol, or a propanol selected from one of 2-propanol and methoxy-propanol, an ether selected from one of ethylene glycol monomethyl ether, triethylene glycol monomethyl ether, and propylene glycol monomethyl ether, an acetate selected from one of methyl acetate, ethyl acetate, and butyl acetate, or any combinations thereof.

5. The composition of claim 4 , wherein concentration of the solvent is less than 30% weight by weight of said composition.

6. The composition of claim 1 , wherein the edible thickener is water-based, and wherein the edible thickener further comprises one or more of a biological gum, sodium alginate and cellulose, wherein the biological gum comprises one or more selected from the group consisting of Cyamopsis tetragonoloba gum, Xanthomonas polysaccharide and carrageenan gum, and wherein the cellulose comprises one or more selected from the group consisting of carboxy methyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl methyl cellulose (HPMC), and carboxymethyl cellulose, and wherein the thickener functions as a thickener, an adhesion promoter and a thixotropic agent, and wherein the thickener has a concentration in a range of less than 1% to less than 5% weight by weight of the composition.

7. The composition of claim 1 , wherein said dispersant comprises a water-based, adhesion promoter resin.

8. The composition of claim 1 , wherein the surfactant comprises one or more compounds selected from a group consisting of disodium monolauryl sulfosuccinate (DLS), disodium laureth sulfosuccinate (MES), disodium cocoyl monoethanolamide sulfosuccinate (DCMS), sodium dodecyl sulfate (SDS), sodium lauryl sulfate (SLS), and soap of fatty acid potassium (SFP), wherein the surfactant has a concentration of less than 5% weight by weight of said composition.

9. The composition of claim 1 , wherein the composition has a shelf life of at least 24 months, and wherein said composition has a viscosity of 100-10000 cP under 25° C.

10. The composition of claim 3 , wherein the composition is used in a number of writing devices including gel pen, ball point pen, ink pen, or brushes for writing on a plurality of substrates, and wherein, said writing forms one or more conductive traces comprising uniform percolation network at room temperature without any curing process.

11. A conductive trace formulation comprising:
a water-based conductive ink, said ink comprising, a solvent, conductive particles comprising one or more metals, an edible thickener, a surfactant, water in the range of 30%-60% weight by weight of the composition, and a dispersant comprising a water-based resin having concentration in a range of 1% to less than 5% weight by weight of the composition, wherein the water-based resin comprises one or more compounds selected from a group consisting of aldehyde ketone resin, epoxy, phenol-formaldehyde resin and polyvinylidene difluoride (PVDF), and wherein the water-based resin having the concentration in the range of 1% to less than 5% weight by weight of the composition makes the conductive ink erasable, and wherein the ink is provided in a writing device and said writing device is moved over a surface comprising one or more flexible substrates to form said conductive trace.

12. The conductive trace formulation of claim 11 , wherein the conductive particles comprise one or more of silver, copper, gold, carbon or any other conductive metal alloy particles and wherein the conductive particles have a size in the range of 1 to 15 micrometers and are present at a concentration in the range of 15% to 50% weight by weight of said ink.

13. The conductive trace formulation of claim 11 , wherein concentration of the solvent is less than 30% weight by weight of said composition.

14. The conductive trace formulation of claim 11 , wherein the flexible substrate is one of copy paper, photo paper, polyethylene terephthalate (PET), flexible printed circuit (FPC), plastic, and metal substrate.

15. The conductive trace formulation of claim 11 , wherein the resistivity of said conductive trace written by said writing devices is in the range of 0.5 to 30 Ω·cm depending on different substrates and wherein said conductive trace can load at least 6 A current flow depending on different substrates.

16. The conductive trace formulation of claim 11 , wherein said conductive trace is capable of being converted from erasable to inerasable by adjusting the amount of said water-based resin.

17. The conductive trace formulation of claim 11 , wherein said conductive trace is cured at room temperature without necessity of additional or external heat.

Assignees

• Nano & Advanced Materials Inst Ltd

Inventors

• Wang Yuechen
• Xu Tao
• Fu Li

Classifications

• C09D11/16

  Writing inks · CPC title

• C09D11/52 Primary

  Electrically conductive inks · CPC title

• C09D11/17

  characterised by colouring agents · CPC title

• H05K3/12

  using {thick film techniques, e.g.} printing techniques to apply the conductive material {or similar techniques for applying conductive paste or ink patterns} · CPC title

• B41M5/0023

  Digital printing methods characterised by the inks used (inks per se C09D11/00) · CPC title