White ink, ink accommodating container, recording device, recording method, and recorded matter
White ink includes a crystalline urethane resin and a coloring material.
1. A white ink, comprising:
a urethane resin; and
a coloring material,
wherein the white ink has a melting peak as measured by a differential scanning calorimeter in the following conditions:
Measuring conditions:
four grams of the white ink is dried at 70 degrees C. for 18 hours and at 120 degrees C. for 15 minutes to prepare a measuring sample, thereafter, a thermal property of the measuring sample is measured by a differential scanning calorimeter Q2000, available from TA Instruments, is measured in a nitrogen atmosphere in a flow rate of 50 mL/minutes under the following temperature conditions: a graph of endotherm amount and exotherm amount is created from measuring results to determine whether the measuring sample has the melting peak in a second temperature rising; and
Temperature Conditions:
Starting Temperature: −20 degrees C.
First temperature rising rate: 10 degrees C./min
Ending temperature: 130 degrees C.
Holding time: one minute
Temperature falling rate: 10 degrees C./min
Ending temperature: −50 degrees C.
Holding time: five minutes
Second temperature rising rate: 10 degrees C./min
Ending temperature: 130 degrees C.
2. The white ink according to claim 1 , wherein the urethane resin has at least one of a cross-linking structure and an elongation structure derived from a polyamine.
3. The white ink according to claim 2 , comprising the elongation structure derived from a polyamine, wherein the polyamine comprises a triamine.
4. The white ink according to claim 1 , wherein the urethane resin has a melting point of from 40 to 100 degrees C.
5. The white ink according to claim 1 , wherein the urethane resin has a crystallization temperature of from −30 to 50 degrees C.
6. The white ink according to claim 1 , wherein a crystalline portion of the urethane resin comprises a polyester.
7. The white ink according to claim 1 , wherein the coloring material comprises at least one of a metal oxide, an inorganic hollow particle, and a resin hollow particle.