Jet drop printing process utilizing a radiation curable ink

• US 4,303,924 A
• Filed: 12/26/1978
• Issued: 12/01/1981
• Est. Priority Date: 12/26/1978
• Status: Expired due to Term

• Current Assignee: Eastman Kodak Company
• Original Assignee: MEAD Corporation (Meadwestvaco Corporation)
• Inventors: Young, Ainslie T. Jr.
• Primary Examiner(s): Hartary, Joseph W.
• Application Number:
  US05/973,120
• Time in Patent Office: 1,071 Days
• Field of Search: 346/1, 346/75, 346/140 R, 106/20, 106/22, 106/30, 427/54.1
• US Class Current: 347/102
• 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: C09D 11/36 based on non-aqueous solvents

Abstract

A jet drop printing process utilizing a radiation (UV, electron beam, etc.) curable ink composition. The ink composition includes a low molecular weight multifunctional ethylenically unsaturated material, a low molecular weight monofunctional ethylenically unsaturated material, a reactive synergist, a dye colorant, and an oil soluble salt. A small amount of organic polar solvent and stabilizer may also be included. In addition, when a UV cure is used, a photoinitiator is also added to the mixture. In order to function properly in the jet drop printing process, the ink composition should have a viscosity of less than about 15 centipoise, a resistivity of around 50-5000 ohm-cm, and a surface tension of approximately 20-70 dynes/cm.

Claims

1. A jet drop printing process utilizing a radiation curable jet printing ink, comprising:

ejecting at high speed from an orifice or orifices a radiation curable ink composition comprising a mixture of

(a) 5-80% of a low molecular weight multifunctional ethylenically unsaturated material which will polymerize and cure upon irradiation,

(b) 0-90% of a low molecular weight monofunctional ethylenically unsaturated material for viscosity control, cured film flexibility and bond strength,

(c) 0-15% of a reactive synergist to promote curing efficiency,

(d) 0.2-10% of a solvent dye colorant which does not interfere with the curing efficiency,

(e) 0.5-15% of an oil soluble salt to impart conductivity,

(f) 0.2-20% of a photoinitiator, and

(g) 0-30% of an organic polar solvent compatible with said mixture, said radiation curable ink having a viscosity of less than about 15 centipoise, a resistivity of approximately 50-5000 ohm-cm, and a surface tension of approximately 20-70 dynes/cm so that the stream of said ink composition issuing from said orifice or orifices breaks into droplets,

passing said stream of droplets through a charge ring to thereby differentially charge said droplets,

selectively deflecting said differentially charged droplets and directing them toward a paper substrate positioned so as to receive a portion of said differentially charged droplets,

depositing at least a portion of said droplets in a pattern on said paper substrate, and

passing said substrate having said pattern deposited thereon under a radiation source for a sufficient period of time to cure said radiation curable jet printing ink whereby there is formed on said substrate a pattern which is light absorptive at infrared wavelengths, smear resistant and waterproof.

2. The process of claim 1 wherein said radiation source is an ultraviolet light.

3. The process of claim 1 wherein said ink composition further includes a small amount of stabilizer to prevent premature curing of said mixture.