Active Filler particles in Inks

• US 20070261595A1
• Filed: 10/06/2005
• Published: 11/15/2007
• Est. Priority Date: 10/08/2004
• Status: Abandoned Application

• Current Assignee: Qinetiq Limited (QinetiQ Group PLC)
• Original Assignee: Qinetiq Limited (QinetiQ Group PLC)
• Inventors: Johnson, Daniel, Damerall, William, Willis, Richard
• Application Number:
  US11/663,819
• Publication Number:
  US 20070261595A1
• Time in Patent Office: Days
• US Class Current: 106/31.130
• CPC Class Codes: C09D 11/101 Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing
• CPC Class Codes: C23C 18/1608 from pretreatment step, i.e. selective pre-treatment
• CPC Class Codes: C23C 18/1653 Two or more layers with at least one layer obtained by electroless plating and one layer obtained by electroplating
• CPC Class Codes: C23C 18/1831 Use of metal, e.g. activation, sensitisation with noble metals
• CPC Class Codes: C23C 18/30 Activating or accelerating or sensitising with palladium or other noble metal
• CPC Class Codes: C23C 18/31 Coating with metals
• CPC Class Codes: H05K 2201/0209 Inorganic, non-metallic particles
• CPC Class Codes: H05K 2201/0212 Resin particles
• CPC Class Codes: H05K 2203/0709 Catalytic ink or adhesive for electroless plating catalyst filler H05K2201/0236
• CPC Class Codes: H05K 3/182 characterised by the patterning method

Abstract

Autocatalytic plating is a form of electrode-less plating in which a metal, for example, cobalt, nickel, gold, silver or copper, is deposited onto a substrate via a chemical reduction process. Coatings derived from this process are usually more uniform and adherent than from other processes and can be applied to unusually shaped surfaces. Non-metallic surfaces can only usually be coated via this process following suitable sensitisation of the substrate. This invention therefore provides a method of preparing a substrate material for subsequent autocatalytic deposition of a metal coating reducing the need for surface preparation by using a reducible silver salt with a suitable filler in a printable ink formulation. Autocatalytic deposition may be used to coat whole surfaces or pre-determined patterns may be deposited by known printing methods.

Claims

1-31. -31. (canceled)

32. A method of preparing a substrate material for subsequent metal plating by an autocatalytic deposition process comprising coating some or all of the substrate material with an ink composition, comprising an ink formulation suitable for printing the substrate to be coated, silver as a reducible silver salt and filler particles, wherein said reducible silver salt is selected such that when reduced it is capable, once the coated substrate is introduced into an autocatalytic deposition solution, of catalysing the deposition of a metal from the autocatalytic deposition solution, onto the coated areas of the substrate, and wherein the proportion of the reducible silver salt is such that the ink composition contains less than 10% by weight of silver.

33. A method according to claim 32 wherein the ink composition is printed onto the substrate by a pattern transfer mechanism.

34. A method according to claim 32 wherein the ink composition contains less than 1% by weight of silver.

35. A method according to claim 34 wherein the ink composition contains less than 0.1% by weight of silver.

36. A method according to claim 32 wherein the reducible silver salt comprises a counterion, wherein the counterion selected from any organic or inorganic counterion.

37. A method according to claim 36 wherein the organic counterion is selected from short chain alkoxy acetate, citrate, acyloxy, or aryloxy, benzoate, or silver protein.

38. A method according to claim 36 wherein the inorganic counterion is selected from nitrate, carbonate, iodide, bromide, nitrite, oxide, perchlorate, permanganate, sulphite, sulphate, thiocyanate.

39. A method according to claim 38 wherein the counterion is nitrate.

40. A method according to claim 32 wherein the ink composition is curable by thermal radiation.

41. A method according to claim 32, wherein the ink composition is curable by Ultra Violet radiation.

42. A method according to claim 32 wherein the ink composition comprises a further metal or metal salt.

43. A method according to claim 32 wherein the ink composition further comprises a pigment or spectroscopically active material.

44. A method according to claim 32 wherein the filler particles are selected from particles of ceramics, polymers, plastics, metals, metal salts, metalloids, or non metals.

45. A method according to claim 44 wherein the filler particles are selected from titanium dioxide, carbon, calcium carbonate, calcium sulphate, alumina, silica or copper oxide.

46. A method according to claim 45 wherein the filler particles are selected from titanium dioxide particles.

47. A method according to claim 32 wherein the diameter of the filler particles is less than 100 μ

m.

48. A method according to claim 47 wherein the diameter of the filler particles is in the range of from 0.05 to 5 μ

m.

49. A method according to claim 48 wherein the diameter of the filler particles is in the range of from 0.2 to 2 μ

m.

50. A method according to claim 32 wherein the filler particles are present in the range of from 5 to 75% w/w of the dry ink composition.

51. A method according to claim 50 wherein the filler particles are present in the range of from 10 to 50% w/w of the dry ink composition.

52. A method according to claim 51 wherein the filler particles are present in the range of from 20 to 40% w/w of the dry ink composition.

53. A method of metal plating a substrate by an autocatalytic deposition process comprising the steps of:

a) preparing the substrate material according to the method of preparing a substrate material as claimed in claim 32, and

b) introducing the prepared substrate material from step (a) into an autocatalytic deposition solution, the autocatalytic solution comprising a metal salt and a reducing agent.

54. An ink composition for carrying out the method according to claim 32, the ink composition comprising a printable ink, a reducible silver salt and a particulate filler material, wherein said ink composition contains less than 10% by weight of silver.

55. An ink composition according to claim 54 wherein the ink composition contains less than 1% by weight of silver.

56. A method according to claim 34 wherein the ink composition contains less than 0.1% by weight of silver.

57. An ink according to claim 54 wherein the particulate filler material is selected from ceramics, polymers, plastics, metals, metal salts, metalloids, or non-metals.

58. An ink according to claim 57 wherein the particulate filler material is selected from titanium dioxide, carbon, calcium carbonate, calcium sulphate, alumina, silica or copper oxide.

59. An ink composition for carrying out the method according claim 32, the ink composition comprising a printable ink, silver nitrate and 5 to 75% w/w titanium dioxide particles.

60. A substrate having deposited thereon an ink composition according to claim 54.