White ink, ink set, and inkjet recording method

Patent metadata

Field	Value
Publication number	US-9803093-B2
Application number	US-201615356832-A
Country	US
Kind code	B2
Filing date	Nov 21, 2016
Priority date	Dec 9, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A white ink includes a hollow resin particle, one or more first organic solvents, an acrylic silicone-based resin, a surfactant; and water. The luminosity (L*) of each of a first dried film having a thickness of 2.2-2.8 μm prepared by drying the white ink at 70 degrees C. and a second dried film having a thickness of 2.2-2.8 μm prepared by drying the white ink at 90 degrees C. is 50 or greater and the decrease ratio of the luminosity (L*) of the second dried film to the first dried film is 10 percent or less.

First claim

What is claimed is:

1. A white ink comprising
a hollow resin particle;
one or more first organic solvents;
an acrylic silicone-based resin;
a surfactant; and
water,
wherein luminosity (L*) of each of a first dried film having a thickness of 2.2-2.8 μm prepared by drying the white ink at 70 degrees C. and a second dried film having a thickness of 2.2-2.8 μm prepared by drying the white ink at 90 degrees C. is 50 or greater and
wherein a decrease ratio of the luminosity (L*) of the second dried film to the first dried film is 10 percent or less.

2. The white ink according to claim 1 , wherein mixing SP of a solution of the first organic solvent and the water of the white ink is 17.0-20.3 (cal/cm 3 ) 0.5 .

3. The white ink according to claim 1 , wherein glass transition temperature of the acrylic silicone-based resin is 30 degrees C. or lower.

4. The white ink according to claim 1 , wherein dynamic surface tension of the white ink is 18-21 mN/m at a bubble life time of 1,500 msec (as measured by maximum bubble pressure technique).

5. The white ink according to claim 1 , wherein each hydrogen bond term of said one or more first organic solvents is 3-6.8 (cal/cm 3 ) 0.5 , and each boiling point of said one or more first organic solvent is 150-300 degrees C.

6. The white ink according to claim 1 , wherein said one of more first organic solvent includes at least one of 1,2-propane diol, 1,3-propane diol, 1,2-butane diol, 1,3-butane diol, isoprene glycol, and an oxetane compound.

7. The white ink according to claim 1 , wherein a mass ratio of the acrylic silicone-based resin to the hollow resin particle is 0.25 to 1.

8. The white ink according to claim 1 , further comprising wax, which includes a polyethylene-based wax emulsion or carnauba wax and has a melting point of the wax is 80-140 degrees C.

9. An ink set comprising:
a white ink including a hollow resin particle, one or more first organic solvents, an acrylic silicone-based resin, a surfactant, and water; and
an ink including a coloring material, a second organic solvent, and water,
wherein luminosity (L*) of each of a first dried film having a thickness of 2.2-2.8 μm prepared by drying the white ink at 70 degrees C. and a second dried film having a thickness of 2.2-2.8 μm prepared by drying the white ink at 90 degrees C. is 50 or greater and wherein a decrease ratio of the luminosity (L*) of the second dried film to the first dried film is 10 percent or less.

10. An inkjet recording method comprising:
applying thermal energy or mechanical energy to a white ink and an ink of an ink set to discharge the white ink and the ink onto a recording medium; and
drying the white ink and the ink on the recording medium wherein the white ink includes a hollow resin particle, one or more first organic solvents, an acrylic silicone-based resin, a surfactant, and water; and the ink includes a coloring material, a second organic solvent, and water,
wherein luminosity (L*) of each of a first dried film having a thickness of 2.2-2.8 μm prepared by drying the white ink at 70 degrees C. and a second dried film having a thickness of 2.2-2.8 μm prepared by drying the white ink at 90 degrees C. is 50 or greater and
wherein a decrease ratio of the luminosity (L*) of the second dried film to the first dried film is 10 percent or less.

Assignees

• Katsuragi Koji
• Ricoh Co Ltd

Inventors

• Katsuragi Koji

Classifications

• C09D11/12

  based on waxes or bitumen · CPC title

• C09D11/36

  based on non-aqueous solvents · CPC title

• B41J2/14016

  Structure of bubble jet print heads · CPC title

• C09D11/40

  Ink-sets specially adapted for multi-colour inkjet printing · CPC title

• C09D11/322

  Pigment inks · CPC title