US 11,655,382 B2
Ink formulations and film constructions thereof
Benzion Landa, Nes Ziona (IL); Gregory Nakhmanovich, Rishon LeZion (IL); Galia Golodetz, Rehovot (IL); and Sagi Abramovich, Ra'anana (IL)
Assigned to LANDA CORPORATION LTD., Rehovot (IL)
Filed on Jul. 6, 2020, as Appl. No. 16/921,736.
Application 16/921,736 is a continuation of application No. 16/048,299, filed on Jul. 29, 2018, granted, now 10,759,953.
Application 16/048,299 is a continuation of application No. 14/917,461, abandoned, previously published as PCT/IB2014/002395, filed on Sep. 11, 2014.
Claims priority of provisional application 61/876,727, filed on Sep. 11, 2013.
Claims priority of application No. 1401173 (GB), filed on Jan. 23, 2014.
Prior Publication US 2021/0062021 A1, Mar. 4, 2021
Int. Cl. C09D 11/107 (2014.01); C09D 11/106 (2014.01); C09D 11/30 (2014.01); C09D 11/38 (2014.01); C09D 11/104 (2014.01)
CPC C09D 11/107 (2013.01) [C09D 11/104 (2013.01); C09D 11/106 (2013.01); C09D 11/30 (2013.01); C09D 11/38 (2013.01)] 15 Claims
1. A method of indirect printing comprising:
a. providing a water-based ink formulation comprising:
(i) a solvent containing water;
(ii) at least one colorant dispersed or at least partly dissolved within the solvent;
(iii) at least one organic polymeric resin, dispersed within the solvent; and
(iv) a softening agent selected to reduce a glass transition temperature (Tg) Of said polymeric resin,
wherein the ink formulation provides all of a first feature, a second feature, a third feature, a fourth feature, and a fifth feature, said first through fifth features being defined below;
b. directing droplets of the ink formulation onto an intermediate transfer member (ITM) having a hydrophobic outer surface so as to form an ink image thereon;
c. subjecting the ink image, on the hydrophobic outer surface of the ITM, to a heating-and-drying process so as to obtain an ink film;
d. subjecting the ITM outer surface to pressurized contact with substrate so as to transfer the ink film thereto,
wherein the first, second, third, fourth, and fifth features are defined as follows:
i. according to the first feature, the ink formulation is either devoid of inorganic filler particles or has an inorganic filler particle concentration of less than 0.1 wt. %;
ii. according to the second feature, the ink formulation forms, when dried, a substantially dry ink residue having:
(A) a first dynamic viscosity within a range of 106 cP to 3·108 cP over at least part of a first temperature range of 60° C. to 110° C.; and
(B) a second dynamic viscosity of at least 6·107 cP, over at least a part of a second temperature range of 50° C. to 55° C.;
said second dynamic viscosity at 55° C. exceeding the first dynamic viscosity at 85° C.;
iii. according to the third feature, said softening agent has a pure vapor pressure of at most 0.40 kPa at 150° C.;
iv. according to the third feature, at least one particular resin of said organic polymeric resin having an elevated glass transition temperature (Tg) of at least 54° C.; and
v. according to the fifth feature, said softening agent is selected and/or added in an amount to reduce said elevated glass transition temperature by at least 5° C.