Conductive ink or paint

• US 6,537,359 B1
• Filed: 10/18/2000
• Issued: 03/25/2003
• Est. Priority Date: 03/03/1998
• Status: Expired due to Term

• Current Assignee: Henkel IP & Holding GmbH (Henkel AG & Co KGaA)
• Original Assignee: National Starch and Chemical Investment Holding Corporation (Ingredion Incorporated)
• Inventors: Spa, Wijchert H.
• Primary Examiner(s): KLEMANSKI, HELENE G
• Application Number:
  US09/623,378
• Time in Patent Office: 888 Days
• Field of Search: 106/31.92, 106/31.32, 106/31.64, 252/500, 252/510, 252/512, 252/514
• US Class Current: 106/31.92
• CPC Class Codes: C09D 11/52 Electrically conductive inks
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H05K 1/095 for polymer thick films, i.e. having a permanent organic polymeric binder

Abstract

The invention relates to a deformable, electrically conductive ink or paint. When the ink or paint is applied to a substrate in the form of a particular pattern, this pattern will also be electrically conductive after deformation. The invention also relates to the use of a deformable, electrically conductive ink or paint for providing an electromagnetic shielding layer or a functionally conductive path.

Claims

1. An electrically conductive, organic solvent based ink or paint comprising electrically conductive particles, a binding agent and a solvent, wherein the ink or paint, after having been applied to a substrate and dried, forms a pattern that can be thermally deformed to an elongation of at least 30% while maintaining a surface resistance of no greater than 10,000 Ω

/□

.

2. An ink or paint according to claim 1, wherein the pattern can be elongated by at least 50%.

3. An ink or paint according to claim 1, wherein the pattern, after elongation, maintains a surface resistance of 100 Ω

/□

at most.

4. An ink or paint according to claim 1, wherein the electrically conductive particles are plate-shaped particles.

5. An ink or paint according to claim 4, wherein the electrically conductive particles are plate-shaped particles having a thickness of 2 μ

m at most and a d₅₀ value of 1-20 μ

m.

6. An ink or paint according to claim 4 or 5, wherein the electrically conductive particles are selected from the group consisting of metal and carbon particles.

7. An ink or paint according to any one of claims 4-6, wherein the binding agent is an elastic resin.

8. An ink or paint according to claim 7, wherein the resin has a molecular weight distribution (M_w/M_n) of 4 at most.

9. An ink or paint according to claim 7 or 8, wherein the resin has a glass-transition temperature of between 10 and 70°

C.

10. An ink or paint according to any one of claims 4-9, wherein the ink or paint comprises 3-90 wt. % of solid substance, calculated on the total quantity of ink or paint.

11. A method for producing a pattern of ink or paint according to any one of the preceding claims on a substrate, wherein the ink or paint is applied to the substrate and dried to form a pattern, which pattern can be thermally deformed to a degree of elongation of 30%, after which the pattern has a surface resistance of 377 Ω

/□

at most.

12. A method according to claim 11, wherein the pattern is deformed to a degree of elongation of at least 30% and has a surface resistance of 377 Ω

/□

or less.

13. A coating in the form of a pattern obtainable by a method according to claim 11 or 12.

14. A method of providing an electromagnetic shielding layer or a functionally conductive path to a substrate comprising the step of applying the ink or paint of claim 1 to a substrate.

15. A method according to claim 14, further comprising the step of applying the ink or paint utilizing an in-mould or an in-mould decoration technique.

16. A substrate comprising an electromagnetic shielding layer or a functionally conductive path of an ink or paint according to claim 1.

17. A substrate according to claim 16, wherein the substrate is selected from the group consisting of a printed circuit board, a printed switch, a heating element, a medical sensor, a membrane switch, or a housing of a telephone, personal computer, computer monitor or television.

18. An ink or paint according to claim 2, wherein the pattern can be elongated by at least 75 to 100%.

19. An ink or paint according to claim 3, wherein the pattern, after elongation, maintains a surface resistance of 0.05-10 Ω

/□

.

20. An ink or paint according to claim 5, wherein the electrically conductive particles are plate-shaped particles having a thickness of 1 μ

m.

21. An ink or paint according to claim 4, wherein the electrically conductive particles are plate-shaped particles having a d₅₀ value of 10-15 μ

m.

22. An ink or paint according to claim 8, wherein the resin has a molecular weight distribution (M_w/M_n) of 3 at most.

23. An ink or paint according to any one of claim 10, wherein the ink or paint comprises 45-75 wt. % of solid substance, calculated on the total quantity of ink or paint.

24. An ink or paint according to claim 1, wherein the binding agent is a resin.