EP0410765A2 - An electrically conductive ink - Google Patents

An electrically conductive ink Download PDF

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Publication number
EP0410765A2
EP0410765A2 EP90308226A EP90308226A EP0410765A2 EP 0410765 A2 EP0410765 A2 EP 0410765A2 EP 90308226 A EP90308226 A EP 90308226A EP 90308226 A EP90308226 A EP 90308226A EP 0410765 A2 EP0410765 A2 EP 0410765A2
Authority
EP
European Patent Office
Prior art keywords
electrically conductive
conductive ink
ink according
constituent
ink
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP90308226A
Other languages
German (de)
French (fr)
Other versions
EP0410765A3 (en
Inventor
Paul Davidson
Colin Ivan Terry
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thorn EMI PLC
Original Assignee
Thorn EMI PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thorn EMI PLC filed Critical Thorn EMI PLC
Publication of EP0410765A2 publication Critical patent/EP0410765A2/en
Publication of EP0410765A3 publication Critical patent/EP0410765A3/en
Withdrawn legal-status Critical Current

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/10—Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor
    • H05B3/12—Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/24—Conductive material dispersed in non-conductive organic material the conductive material comprising carbon-silicon compounds, carbon or silicon

Definitions

  • the present invention relates to an electrically conductive ink comprising a binder and an electrically conductive constituent, in particular to a conductive polymer, and to a thick film electrically resistive track made from the same.
  • Conductive polymer inks are known in the art.
  • Japanese Patent Application No. 60-218689 laid open under No. 62-7495 discloses examples of an electrically conductive ink in which the binder is a resin chosen from a group termed 'heat -resisting engineering plastics' and in which the electrically conductive powder is silver.
  • This publication further dicloses that tests have shown that gold, silver, copper, nickel and carbon are satisfactory as the electrically conductive powder used in the ink and accordingly claims an electrically conductive ink characterized by the fact that the electrically conductive powder is at least one of the powders chosen from the group consisting of gold, silver, copper, nickel and carbon.
  • Figure 1 which is taken from that publication, shows the variation of resistivity with proportion by weight of blends of silver and a second constituent.
  • Curve 2 is for a silver/graphite blend system;
  • Curve 4 is for a blend system containing a silver-based polymeric ink and a non-conductive aluminium based polymeric ink.
  • the resistivity of the ink increases with the proportion of the second constituent.
  • an electrically conductive ink comprising a binder and an electrically conductive constituent, wherein the electrically conductive constituent includes a dendritic metal.
  • the electrically conductive constituent comprises a mixture of dendritic metal and carbon.
  • the inventors have found that an ink of low resitivity can be achieved by a mixture of a dendritic metal and carbon, which is a contradistinction to the teachings of the prior art, as shown in Figure 1.
  • the dendritic metal consists of nickel.
  • Electrically conductive inks provided in accordance with the present invention are particularly suitable for the manufacture of heating elements for large areas such as door mirrors in motor vehicles. Heating elements so produced compare favourably in both cost and heating effect with prior art heating elements used for such applications.
  • a dendritic metal is one in which the surface of the metal appears spiky, and in powdered form, the granules are generally of equiaxial shape.
  • the binder and 100 g of the conductive constituent are added to 55g of the screen printing medium.
  • the mixture is then passed through a triple roll mill until the rheological properties suitable for screen printing known to those skilled in the art are obtained.
  • the resulting ink is screen printed in the desired pattern onto a substrate and cured at a temperature of 80 o C.
  • the ink exhibits good adhesion to a variety of types of substrates, including alumina, polyester, glass and painted surfaces.
  • the resistivity of tracks made from this ink was in the range of from 1.5 to 2.0 ohms per square.

Abstract

An electrically conductive ink, and film-type tracks made therefrom comprise a dendritic metal and carbon in a mixture which affords good electrical conductivity. Such inks and tracks are particularly adaptable for use in heated automotive mirrors.

Description

  • The present invention relates to an electrically conductive ink comprising a binder and an electrically conductive constituent, in particular to a conductive polymer, and to a thick film electrically resistive track made from the same.
  • Conductive polymer inks are known in the art. Japanese Patent Application No. 60-218689 laid open under No. 62-7495 (Nihon Shashin Insatsu) discloses examples of an electrically conductive ink in which the binder is a resin chosen from a group termed 'heat -resisting engineering plastics' and in which the electrically conductive powder is silver. This publication further dicloses that tests have shown that gold, silver, copper, nickel and carbon are satisfactory as the electrically conductive powder used in the ink and accordingly claims an electrically conductive ink characterized by the fact that the electrically conductive powder is at least one of the powders chosen from the group consisting of gold, silver, copper, nickel and carbon.
  • As disclosed by N. Nazarenko and C.N. Lazaridis 'Polymer Thick Film Conductors and Dielectrics for Membrane Switches and Flexible Circuitry' (Publication reprinted from the Proceedings of the 1982 ISHM Symposium), it is known that products having a low resistance can be made from silver-based conductive inks.
  • However, in view of the cost of silver, there is a need for conductive inks containing less silver. Figure 1 which is taken from that publication, shows the variation of resistivity with proportion by weight of blends of silver and a second constituent. Curve 2 is for a silver/graphite blend system; Curve 4 is for a blend system containing a silver-based polymeric ink and a non-conductive aluminium based polymeric ink. As can be seen from the Figure, the resistivity of the ink increases with the proportion of the second constituent.
  • It is an object of the present invention to provide a low resistivity electrically conductive ink suitable for producing a film-type heating track.
  • According to the present invention there is provided an electrically conductive ink comprising a binder and an electrically conductive constituent, wherein the electrically conductive constituent includes a dendritic metal. Thus, by incorporating a dendritic metal into the electrically conductive constituent, an ink of particularly low resistivity, as compared with the prior art is achieved.
  • Preferably, the electrically conductive constituent comprises a mixture of dendritic metal and carbon. The inventors have found that an ink of low resitivity can be achieved by a mixture of a dendritic metal and carbon, which is a contradistinction to the teachings of the prior art, as shown in Figure 1.
  • Preferably, the dendritic metal consists of nickel. Electrically conductive inks provided in accordance with the present invention are particularly suitable for the manufacture of heating elements for large areas such as door mirrors in motor vehicles. Heating elements so produced compare favourably in both cost and heating effect with prior art heating elements used for such applications.
  • An embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying drawings of which:
    • Figure 1 shows variation in resitivity with relative proportions of constituents in prior art inks;
    • and figure 2 shows variation in resistivity with relative proportions of nickel and carbon in an ink provided in accordance with the present invention.
  • It has been found that a method of manufacturing the electrically conductive which employs a powdered dendritic metal produces an ink with high electrical conductivity as compared to the prior art.
  • A dendritic metal is one in which the surface of the metal appears spiky, and in powdered form, the granules are generally of equiaxial shape.
  • A method of making an electrically conductive ink provided in accordance with the present invention is described below.
    • a) A stock solution of the binder is formed by dissolving 20 g of poly (vinyl butyral) granules (Butvar B76) in l00g of N-methyl-2-pyrrolidone. This is mixed using a high speed stirrer for 1 hour and then allowed to settle until the air disperses.
    • b) 55 ml of carbon black (type 40220) is baked for 1 hour at 125oC to remove any moisture. This is used with an equal volume of dendritic metal powder, nickel has been found to be particularly suitable for obtaining a high-conductivity ink, untilan homogenous blend is obtained. This forms the electrically conductive constituent.
    • c) A screen printing medium is produced by combining 50 g of Blythe medium type 63/182 with 5g of unaccelerated unsaturated polyester in styrene (manufactured by Scott Bader).
  • 50g of the binder and 100 g of the conductive constituent are added to 55g of the screen printing medium. The mixture is then passed through a triple roll mill until the rheological properties suitable for screen printing known to those skilled in the art are obtained. The resulting ink is screen printed in the desired pattern onto a substrate and cured at a temperature of 80oC.
  • The ink exhibits good adhesion to a variety of types of substrates, including alumina, polyester, glass and painted surfaces. The resistivity of tracks made from this ink was in the range of from 1.5 to 2.0 ohms per square.

Claims (11)

1. An electrically conductive ink comprising a binder and an electrically conductive constituent, wherein the electrically conductive constituent includes a dendritic metal.
2. An electrically conductive ink according to claim 1 wherein the electrically conductive constituent comprises a mixture of a dendritic metal and carbon.
3. An electrically conductive ink according to claim 1 or claim 2 wherein the dendritic metal consists of nickel.
4. An electrically conductive ink according to Claim 3 wherein the electrically conductive constituent includes nickel as a percentage by volume in the range from 30% to 85%.
5. An electrically conductive ink according to Claim 4 wherein the electrically conductive constituent includes nickel as a percentage by volume in the range of from 33% to 80%.
6. An electrically conductive ink according to Claim 5 wherein the electrically conductive constituent includes nickel as a percentage by volume in the range from 36% to 67%.
7. An electrically conductive ink according to claim 6 wherein the electrically conductive constituent constists of nickel and carbon in equal proportions by volume.
8. An electrically conductive ink according to any one of the proceding claims.
9. An electrically conductive ink according to claim 8 wherein the polymer comprises a thermoplastic resin.
10. An electrically conductive ink according to claim 8 wherein the binder comprises polyvinyl butyral.
11. A film-type track for use as a heating element constructed from an electrically conductive ink according to any one of the preceding claims.
EP19900308226 1989-07-26 1990-07-26 An electrically conductive ink Withdrawn EP0410765A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8917078 1989-07-26
GB898917078A GB8917078D0 (en) 1989-07-26 1989-07-26 An electrically conductive ink

Publications (2)

Publication Number Publication Date
EP0410765A2 true EP0410765A2 (en) 1991-01-30
EP0410765A3 EP0410765A3 (en) 1991-05-29

Family

ID=10660650

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19900308226 Withdrawn EP0410765A3 (en) 1989-07-26 1990-07-26 An electrically conductive ink

Country Status (5)

Country Link
EP (1) EP0410765A3 (en)
JP (1) JPH03143967A (en)
AU (1) AU645020B2 (en)
CA (1) CA2021938A1 (en)
GB (1) GB8917078D0 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0753410A2 (en) * 1995-06-28 1997-01-15 Riso Kagaku Corporation Ink jet device and conductive liquid
WO2006076607A1 (en) * 2005-01-14 2006-07-20 Cabot Corporation Ink-jet printing of passive electricalcomponents
US8383014B2 (en) 2010-06-15 2013-02-26 Cabot Corporation Metal nanoparticle compositions
CN107071934A (en) * 2017-04-19 2017-08-18 苏州康智元智能科技有限公司 Graphene line with heating function and preparation method thereof

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4759899B2 (en) * 2001-09-28 2011-08-31 大日本印刷株式会社 Electromagnetic shielding material and flat cable with electromagnetic shielding
TW200642785A (en) 2005-01-14 2006-12-16 Cabot Corp Metal nanoparticle compositions
US7824466B2 (en) 2005-01-14 2010-11-02 Cabot Corporation Production of metal nanoparticles
WO2006076609A2 (en) 2005-01-14 2006-07-20 Cabot Corporation Printable electronic features on non-uniform substrate and processes for making same
WO2006076606A2 (en) 2005-01-14 2006-07-20 Cabot Corporation Optimized multi-layer printing of electronics and displays
US8158032B2 (en) * 2010-08-20 2012-04-17 Xerox Corporation Silver nanoparticle ink composition for highly conductive features with enhanced mechanical properties

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2124401A1 (en) * 1971-02-03 1972-09-22 Matsushita Electric Ind Co Ltd

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1159606B (en) * 1983-09-09 1987-03-04 Olivetti & Co Spa ELECTRICALLY CONDUCTIVE INK SELECTIVE INK PRINTERS
US5002826A (en) * 1988-09-01 1991-03-26 James River Corporation Of Virginia Heaters for use in microwave ovens

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2124401A1 (en) * 1971-02-03 1972-09-22 Matsushita Electric Ind Co Ltd
FR2124400A1 (en) * 1971-02-03 1972-09-22 Matsushita Electric Ind Co Ltd

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
database derwent world patent index & JPA 62074975(nihon shashin) 06-04-87 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0753410A2 (en) * 1995-06-28 1997-01-15 Riso Kagaku Corporation Ink jet device and conductive liquid
EP0753410A3 (en) * 1995-06-28 1997-06-25 Riso Kagaku Corp Ink jet device and conductive liquid
WO2006076607A1 (en) * 2005-01-14 2006-07-20 Cabot Corporation Ink-jet printing of passive electricalcomponents
US8668848B2 (en) 2005-01-14 2014-03-11 Cabot Corporation Metal nanoparticle compositions for reflective features
US8383014B2 (en) 2010-06-15 2013-02-26 Cabot Corporation Metal nanoparticle compositions
CN107071934A (en) * 2017-04-19 2017-08-18 苏州康智元智能科技有限公司 Graphene line with heating function and preparation method thereof

Also Published As

Publication number Publication date
EP0410765A3 (en) 1991-05-29
JPH03143967A (en) 1991-06-19
GB8917078D0 (en) 1989-09-13
AU645020B2 (en) 1994-01-06
AU5983590A (en) 1991-01-31
CA2021938A1 (en) 1991-01-27

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