INKS COMPRISING GELLANTS FOR 3D PRINTING
In one aspect, methods of printing a three-dimensional article are described herein. In some embodiments, a method described herein comprises jetting an ink at a temperature T 1 onto a substrate at a temperature T 2 to form a layer of the ink on the substrate. The method further comprises subsequently curing the layer of the ink. In some embodiments, T 1 is greater than T 2 and the ink in an uncured state has a liquid-gel transition temperature below T 1 and above T 2 . Further, the layer of the ink is deposited on the substrate at a rate R 1 in mg/s/in 2 that is within 60% of a gelation rate R 2 of the ink in inverse minutes in an uncured state at T 2 . The ink can comprise a curable material and a gellant.
1 . An ink for three-dimensional printing, comprising:
a curable material and a gellant, the gellant comprising a chemical species having one or more terminal olefin moieties linked to a hydrophobic segment by one or more urethane, urea, and/or amide moieties,
wherein the ink has a gelation rate of 0.56 to 20 min. −1 .
2 . The ink of claim 1 , wherein the ink has a gelation rate of 1.7 to 20 min. −1 .
3 . The ink of claim 1 , wherein the ink exhibits a liquid-gel transition between 30° C. and 75° C.
4 . The ink of claim 1 , wherein the ink makes a liquid-gel transition over a temperature range of X±15, X±10, or X±5, wherein X is a temperature at which the transition is centered.
5 . The ink of claim 4 , wherein the ink makes a liquid-gel transition over a temperature range of X±5.
6 . The ink of claim 1 , wherein the ink has a heat of fusion of a liquid-gel transition of 20 j/g or less.
7 . The ink of claim 1 , wherein the ink has a viscosity of 8.0 to 12.5 cP at 80° C.
8 . The ink of claim 1 , wherein the curable material comprises one or more oligomeric materials and wherein the one or more oligomeric materials comprise a urethane (meth)acrylate.
9 . The ink of claim 1 , wherein the curable material is present in the ink in an amount of 50-98 weight % and wherein the gellant is present in the ink in an amount of 2-20 weight %, based on the total weight of the ink.
10 . The ink of claim 1 , wherein the gellant is formed from the reaction of compound (A) with compound (B) and compound (C):
OCN—R 1 —NCO (A),
HO—R 2 —OH (B), and
wherein R 2 , R 2 , and R 3 are each independently a linear or branched alkyl, aryl, alkylaryl, or arylalkyl moiety having from 1 to 50 carbon atoms;
R 4 is —H or CH 3 ; and
X is —O—, —OCH 2 —, —OC(O)—, or —CH 2 —.
11 . The ink of claim 1 , wherein the gellant comprises a chemical species having the structure of Formula (I):
wherein R 1 , R 2 , and R 3 are each independently a linear or branched alkyl, aryl, alkylaryl, or arylalkyl moiety having from 1 to 30 carbon atoms;
R 4 is —H or CH 3 ;
X is —O—, —OCH 2 —, —OC(O)—, or —CH 2 —; and
represents a single carbon-carbon bond between the R 2 moieties.
12 . The ink of claim 1 , wherein the gellant comprises a chemical species having the structure of Formula (II):
13 . The ink of claim 1 , wherein the gellant is formed from the reaction of compound (A) or (A′) with compound (B) or (B′) and compound (C) or (C′):
OCN—R 1 —NCO (A),
R 1 —NCO (A′),
HO—R 2 —OH (B),
R 2 —OH (B′),
wherein R 2 , R 2 , and R 3 are each independently a linear or branched alkyl, aryl, alkylaryl, or arylalkyl moiety having from 1 to 50 carbon atoms;
R 4 is —H or —CH 3 ; and
X is —O—, —OCH 2 —, —OC(O)—, or —CH 2 —.
14 . The ink of claim 1 , wherein the gellant comprises a chemical species having the structure of Formula (III):
wherein R 2 , R 2 , and R 3 are each independently a linear or branched alkyl, aryl, alkylaryl, or arylalkyl moiety having from 1 to 50 carbon atoms;
R4 is —H or —CH 3 ; and
X is —O—, —OCH 2 —, —OC(O)—, or —CH 2 —.
15 . The ink of claim 1 , wherein the gellant comprises a chemical species of Formula (VI):
wherein x is an integer from 0 to 34;
y is an integer from 1 to 1 7; and
R 4 is H or CH 3 .
16 . The ink of claim 1 , wherein the gellant comprises a chemical species of Formula (VII):
wherein x is an integer from 0 to 34;
y is an integer from 1 to 17; and
R is H or CH 3 .
17 . The ink of claim 1 , wherein the ink has an optical transparency of at least 0% transmission between 350 nm and 750 nm, at a thickness of 0.03 to 5 mm.
18 . An ink for three-dimensional printing by jetting an ink at a temperature T 1 and at a rate R 1 in mg/s/in 2 onto a substrate at a temperature T 2 , the ink comprising:
a curable material and a gellant, the gellant comprising a chemical species having one or more terminal olefin moieties linked to a hydrophobic segment by one or more urethane, urea, and/or amide moieties,
wherein the ink, in an uncured state, has a liquid-gel transition temperature below T 1 and above T 2 , and
wherein R 1 is within 60% of a gelation rate R 2 of the ink in inverse minutes in an uncured state at T 2 , the percentage being based on the larger of R 1 and R 2 .
19 . The ink of claim 18 , wherein the gelation rate R 2 is 0.56 to 20 min. −1 .
20 . The ink of claim 18 , wherein the liquid-gel transition temperature is between 30° C. and 75° C.