INKS CONTAINING METAL PRECURSORS NANOPARTICLES

Abstract

Provided herein are novel ink formulations based on metal salts and metal complexes.

Claims

1. A printing formulation (ink) comprising at least one metal precursor in the form of a metal complex dissolved in a medium, wherein said complex having one or more hydroxy amine or amino acid complexing moieties.

2. The printing formulation of claim 1, further comprising at least one printing suitable liquid carrier.

3-12. (canceled)

13. The printing formulation of claim 1, wherein said metal precursor is of a metal of Groups IIIB, IVB, VB, VIB, VIIB, VIIIB, IB and IIB of block d of the Periodic Table of Elements.

14. The printing formulation of claim 13, wherein said metal is selected from Sc, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Y, Zr, Nb, Tc, Ru, Mo, Rh, W, Au, Pt, Pd, Ag, Mn, Co, Cd, Hf, Ta, Re, Os, Al, Sn, In, Ga and Ir.

15. The printing formulation of claim 14, wherein said metal is selected from Cu, Ni, Ag, Au, Pt, Pd, Al, Fe, Co, Ti, Zn, In, Sn and Ga.

16. The printing formulation of claim 15, wherein said metal is selected from Cu, Ni and Ag.

17. (canceled)

18. The printing formulation of claim 15, wherein said metal is Cu.

19-40. (canceled)

41. The printing formulation of claim 1, wherein the metal complex comprises organic complexing moieties.

42. The printing formulation of claim 41, wherein said complexing moieties are amino acids.

43. The printing formulation of claim 1, wherein the metallic complex is selected from a copper complex, a nickel complex, an aluminum complex, a cobalt complex, a tin complex, an indium complex, and a zinc complex.

44. The printing formulation of claim 43, wherein the metal is copper and the copper complex is selected to easily decompose at a low temperature.

45. The printing formulation of claim 43, wherein the copper complex comprises amine and hydroxy complexing moieties.

46. The printing formulation of claim 45, wherein the complexing moieties are selected from ethanol amine, di-ethanol amine, triethanol amine, amino methyl propanol (AMP 95), 1-amino-2-propanol, 3-amino-1-propanol and diisopropanolamine.

47-74. (canceled)

75. The printing formulation according to of claim 1, comprising at least one metal complex, wherein the at least one metal atom being associated to at least one additive.

76. The printing formulation of claim 75, wherein the additive is selected from conducting metallic particles, conducting metallic nanoparticles, a metal precursor, an oxidant, an anti-oxidant, a stabilizer, a solvent, a humectant, a dispersing agent, a binder, a reducing agent, a surfactant, a wetting agent and a leveling agent.

77. The printing formulation of claim 1, the formulation comprising the medium and a combination of: (1) metal precursor in the form of metal salt nanoparticles dispersed in said medium; and (2) the metal precursor in the form of the metal complex dissolved in said medium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0144] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0145] FIG. 1 demonstrates the effect of solid loading (copper formate wt %) on the particle size at a constant stabilizer-to-solid ratio. The upper line describes the effect for 30 min milling and the bottom line for 60 min of milling

[0146] FIG. 2 presents HR-SEM image of the a metallic layer after decomposition of a metal complex ink, in accordance with the present invention, as described in Example 1, formulation 3.

DETAILED DESCRIPTION OF EMBODIMENTS

[0147] I. Copper Complex Ink Formulation

[0148] Formulation 1:

[0149] 4 g copper formate (.Math.4H.sub.2O) were dissolved in 2 g amino methyl propanol (AMP). The mole ratio of copper formate to AMP was 0.8. The formulation was placed on polyethylene terphthalate (PET) film and was heated under nitrogen flow for 10 min at 150 C. A copper like appearance was observed and a sheet resistance of 5 mOhms per square was measured. The sheet resistance was measured again after a week and after a month, and the measured values were found to be, 7 and 10 mOhms per square, respectively.

[0150] Formulation 2:

[0151] A similar formulation was prepared with another solvent, in which 2.5 g copper formate was dissolved in 2 g butanol and 1.5 g amino methyl propanol (AMP).

[0152] Formulation 3:

[0153] A similar formulation was prepared with another solvent, in which 2.5 g copper formate was dissolved in 2 g dipropylene glycol methyl ether (DPM) and 1.5 g Amino methyl propanol (AMP). This formulation was placed on a glass slide and was heated under nitrogen flow for 20 min at 130 C. A copper like appearance was observed and a sheet resistance of 20 mOhms per square was measured. The sheet resistance was measured again after a week and after a month, and the measured values were found to be, 28 and 50 mOhms per square, respectively.

[0154] Formulation 4:

[0155] 2.5 g copper formate was dissolved in 2.5 g octanol, 5.5 g butanol and 1.5 g amino methyl propanol (AMP) and a wetting agent (BYK 333). The formulation was inkjet printed by UniJet printer equipped with Samsung Minihead (30 pl).

[0156] Formulation 5:

[0157] 3 g copper formate was dissolved in 2 g butanol and 2 g amino methyl propanol (AMP). The formulation was placed on a glass slide and was heated under nitrogen flow for 20 min at 200 C. A copper like appearance was observed and a sheet resistance of 33 mOhms per square was measured.

[0158] Formulation 6:

[0159] 2 g copper formate was dissolved in 7 g DPM and 1.5 g amino methyl propanol (AMP). That formulation was inkjet printed by UniJet printer equipped with Samsung Minihead (30 pl). The DSC results (not provided) obtained for Formulations 5 and 6 indicated that when a solvent such as butanol (which has a low boiling point) was used, as in Formulation 5, an endothermic peak of the solvent evaporation was observed at 110 C., and an exothermic peak of the copper complex decomposition was observed at 145 C. In the case of a high boiling point solvent, such as TPM, utilized in Formulation 6, these peaks were less clear. However, it was noted that the decomposition (accompanied by an exothermic peak) took place around 140 C., while the solvent evaporated at a much higher temperature of 172 C.

[0160] Formulation 7:

[0161] 1.75 g copper formate was dissolved in 3 g butanol, 5 g triprolylene glycol methyl ether (TPM) and 1 g amino methyl propanol (AMP). The formulation was inkjet printed by UniJet printer equipped with Samsung Minihead (30 pl). The printed patterns were heated to 150 C. for 10 min and the resistance along 2.5 cm lines was measured at 7.8 Ohms, while the sheet resistance measured was 0.156 Ohms per square.

[0162] Formulation 8:

[0163] Nickel acetate with AMP in DPM4 g Nickel acetate was dissolved in 2 g DPM and 2 g amino methyl propanol (AMP). The formulation was drawn down on a glass slide and was heated under nitrogen flow for 30 min at 250 C. A shiny grey appearance was observed and a sheet resistance of 1.7 Ohms per square was measured.

[0164] Formulation 9:

[0165] Nickel acetate with AMP in butanol4 g Nickel acetate was dissolved in 2 g butanol and 2 g amino methyl propanol (AMP). The formulation was drawn down on a glass slide and was heated under nitrogen flow for 15 min at 250 C. A shiny grey appearance was observed and a sheet resistance of 6.5 Ohms per square was measured.

[0166] II. Copper Metal Particles Obtained by Bead Milling

EXAMPLE 1

[0167] 75 g of copper formate was mixed with 7.5 g of a cationic polymer (MW=2000) and with 67.5 g DPM (Dipropylene glycol methyl ether). The mixture was bead milled (WAB) to obtain copper formate nanoparticles with an average diameter of 290 nm (according to DLS measurements, not shown).

[0168] The formulation was drawn down on a glass slide and heated to 200 C. under nitrogen for 20 min A sheet resistance of 20 mOhms per square was measured. The heating was carried out under reducing atmosphere. In several alternatives, the reducing atmosphere contained hydrogen, formic acid or other carboxylic acids.

EXAMPLE 2

[0169] 75 g of copper formate was mixed with 7.5 g of an ammonium salt of a co-polymer with acidic groups, 67.5 g DPM (dipropylene glycol methyl ether). The mixture was bead milled (WAB) by using 0.35mm beads to obtain copper formate nanoparticles with an average diameter of 568 nm (according to DLS measurements, not shown).

EXAMPLE 3

Copper Particles Obtained by Bead Milling with 0.1 mm Beads

[0170] The particles obtained in Example 2 were further milled using 0.1 mm beads. The particle size decreased to 115 nm.

EXAMPLE 4

[0171] 75 g of Nickel formate were mixed with 7.5 g of a cationic polymer (MW=2000) with 67.5 g DPM (Dipropylene glycol methyl ether). Then, the mixture was bead milled (WAB) to obtain nickel formate nanoparticics.

EXAMPLE 5

Mixture of Copper and Nickel Precursor Particles Obtained by Bead Milling

[0172] 37.5 g of Nickel formate and 37.5 g of copper formate were mixed with 7.5 g of a cationic polymer (MW=2000) with 67.5 g DPM (Dipropylene glycol methyl ether). Then the mixture was bead milled (WAB) to obtain copper and nickel formate NPs.

EXAMPLE 6

Silver Lactate Particles Obtained by Bead Milling

[0173] Silver lactate was milled with a stabilizing polymer with and DPM (Dipropylene glycol methyl ether). The formulation was drawn down on a glass slide and heated to 170 C. for 5 min in air. A sheet resistance of 6 Ohms per square was measured.

EXAMPLE 7

Silver Oxalate Particles Obtained by Bead Milling

[0174] Silver oxalate was milled with a stabilizing polymer with and DPM (Dipropylene glycol methyl ether). The formulation was drawn down on a glass slide and heated to 150 C. A sheet resistance of 0.2 Ohms per square was measured.

EXAMPLE 8

Washing of Copper Formate Particles by Centrifugation

[0175] The particles obtained in Example 2 were washed by centrifugation at 4000 RPM for 25 min, then the supernatant was decanted and the centrifugation was repeated again. The obtained dispersion was drawn down on a glass slide and was heated under nitrogen to 200 C. for 30 min. The obtained layer showed a sheet resistance of 0.5 ohms/square.

EXAMPLE 9

Copper Precursor as Particles Obtained by Precipitation

[0176] 2 g of copper carbonate were mixed with an polymeric stabilizer in DPM in a hot bath (95 deg C.). Then 4 ml of formic acid were added and after a few seconds a gas was released (CO.sub.2) from the reactor accompanied by a color change of the dispersion from green to blue, indicating the formation of copper formate.

[0177] III. Copper Metal Particles Obtained by Precipitation

EXAMPLE 1

Copper Precursor Particles Obtained by Precipitation

[0178] 1 ml of 10 wt % copper formate aqueous solution was injected to 5 ml acetone with 0.1 g of a polymeric stabilizer while stirring at room temperature. After a few minutes the stirring was stopped and copper formate nanoparticles with an average diameter of 700 nm (according to DLS measurements) were obtained.

EXAMPLE 2

Copper Precursor Particles Obtained by Emulsion-Solvent Evaporation

[0179] An emulsion was formed by homogenizing 10.25 g cyclometicone and 2.25 g Abil EM90 with 12.5 g aqueous solution of 10 wt % copper formate. After evaporation of the water from the emulsion by a rotor evaporator, a dispersion of copper formate nanoparticles with a diameter of 236 nm (according to DLS measurements) was obtained.