Inks comprising gellants for 3d printing

Abstract

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.

That which is claimed: 
     
         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.