Blocking groups for light polymerizable resins useful in additive manufacturing

Abstract

Provided herein is a method of forming a three-dimensional object in which the polymerizable liquid includes a mixture of (i) a light polymerizable first component, and (ii) a heat polymerizable second component; the heat polymerizable second component comprising (i) a first blocked reactive constituent that is blocked with a volatile blocking group, and optionally (ii) a curative. Upon heating a formed three-dimensional intermediate sufficiently, the volatile blocking group is cleaved and vaporizes out of the three-dimensional intermediate, to form the three-dimensional object. Also provided is a three-dimensional object produced by the method. Further provided is a polymerizable liquid composition useful for carrying out the method, and prepolymers and monomers useful for the polymerizable liquid composition.

We claim: 
     
         1 . A three-dimensional object produced by a method comprising:
 (a) providing a carrier and an optically transparent member having a build surface, said carrier and said build surface defining a build region therebetween;   (b) filling said build region with a polymerizable liquid, said polymerizable liquid comprising a mixture of (i) a light polymerizable first component, and (ii) a heat polymerizable second component;   said heat polymerizable second component comprising (i) a first blocked reactive constituent that is blocked with a volatile blocking group, and optionally but preferably (ii) a curative;   (c) irradiating said build region with light through said optically transparent member to form a solid polymer scaffold from said first component and also advancing said carrier and said build surface away from one another to form a three-dimensional intermediate having the same shape as, or a shape to be imparted to, said three-dimensional object, with said three-dimensional intermediate containing said first blocked reactive constituent in unpolymerized form; and then   (d) heating said three-dimensional intermediate sufficiently to (i) cleave said volatile blocking group from said reactive constituent and (ii) polymerize said blocked reactive constituent with itself, and/or said curative, and with (iii) said volatile blocking group vaporizing out of said three-dimensional intermediate, to form said three-dimensional object   (e.g., wherein said object includes a three-dimensional lattice).   
     
     
         2 . A polymerizable liquid composition (preferably non-aqueous) useful for producing objects by additive manufacturing, comprising:
 (a) a light polymerizable first component, and   (b) a heat polymerizable second component; said heat polymerizable second component comprising:
 (i) a first blocked reactive constituent that is blocked with a volatile blocking group, and 
 (ii) a curative, 
   wherein said light polymerizable first component comprises a second blocked reactive constituent that is blocked with a light reactive blocking group, optionally wherein during heating, at least a portion of a solid polymer scaffold produced by light polymerization of said second reactive constituent degrades and forms a constituent that participates in heat polymerizing, and said second blocked reactive constituent comprises a blocked polyisocyanate having two or more ethylenically unsaturated end groups.   
     
     
         3 . The composition of  claim 2 , wherein said volatile blocking group comprises a ketoxime, amide, imide, imidazole, pyrazole, alcohol, or sterically-hindered amine blocking group. 
     
     
         4 . The composition of  claim 2 , wherein said first blocked reactive constituent comprises a blocked polyisocyanate. 
     
     
         5 . The composition of  claim 2 , wherein said first blocked reactive constituent comprises a ketoxime-blocked polyisocyanate. 
     
     
         6 . The composition of  claim 2 , wherein said curative comprises a polyol, a polyamine, a polyetheramine, or a combination thereof. 
     
     
         7 . The composition of  claim 2 , wherein said first blocked reactive constituent is included in said polymerizable liquid in an amount of from 1, 2, 5 or 10 percent by weight, to 30, 40, or 50 percent by weight, or more. 
     
     
         8 . The composition of  claim 2 , said polymerizable liquid further comprising at least one photoinitiator (e.g., in an amount of from 0.1 to 1 or 5 percent by weight), optionally at least one dye (e.g., in an amount of 0.001 or 0.01 to 1 or 5 percent by weight), and optionally at least one filler (e.g., in an amount of 0.01 or 0.1 to 20 or 50 percent by weight). 
     
     
         9 . The composition of  claim 2 , wherein during heating, at least a portion of a solid polymer scaffold produced by light polymerization of said second reactive constituent degrades and forms a constituent that participates in heat polymerizing. 
     
     
         10 . The composition of  claim 2 , wherein said second blocked reactive constituent is included in said polymerizable liquid in an amount of from 1, 2, 5 or 10 percent by weight, to 30, 40, or 50 percent by weight, or more. 
     
     
         11 . The composition of  claim 2 , wherein said first blocked reactive constituent (e.g., VBPU) and said second blocked reactive constituent (e.g., ABPU), are included together in said polymerizable liquid in a weight ratio of from 1:5, 1:10 or 1:20, to 5:1, 10:1 or 20:1. 
     
     
         12 . The composition of  claim 2 , wherein: said second component comprises precursors to a polyurethane, polyurea, or copolymer thereof; a silicone resin, an epoxy resin, a cyanate ester resin, or a natural rubber. 
     
     
         13 . A prepolymer compound of formula I: 
       
         
           
           
               
               
           
         
         wherein: 
         B 1  is a reactive blocking group (e.g., comprising acrylates, methacrylates, α-olefins, N-vinyls, acrylamides, methacrylamides, styrenics, epoxides, thiols, 1,3-dienes, vinyl halides, acrylonitriles, vinyl esters, maleimides, vinyl ethers, and ethylenically unsaturated end groups); 
         B 2  is a volatile blocking group (e.g., comprising ketoximes, amides, imides, imidazoles, oximes, pyrazoles, alcohols, phenols, sterically-hindered amines, lactams, succinimides, triazoles, and phthalimides); 
         R 1  and R 2  are independently selected from the group comprising an aliphatic, aromatic or mixed aliphatic and aromatic group 
       
       
         
           
           
               
               
           
         
         X is O, S, or NR 3 , wherein R 3  is H or a straight chain or branched C 1 -C 10  alkyl group; 
         Z is a polymeric organic group (e.g., (CH 2 ) 3 ); 
         n is an integer in the range of 1 to 150; and 
         m is an integer in the range of 1 to 100. 
       
     
     
         14 . The prepolymer compound of  claim 13 , wherein B 2  is a pyrazole 
       
         
           
           
               
               
           
         
       
     
     
         15 . The prepolymer compound of  claim 13 , wherein B 1  is an acrylate or methacrylate 
       
         
           
           
               
               
           
         
       
     
     
         16 . The prepolymer compound of  claim 14 , wherein B 1  is an acrylate or methacrylate 
       
         
           
           
               
               
           
         
       
     
     
         17 . A polymerizable liquid composition comprising a prepolymer compound of  claim 13 . 
     
     
         18 . The composition of  claim 17 , wherein said composition further comprises a curative. 
     
     
         19 . The composition of  claim 17 , said polymerizable liquid further comprising at least one photoinitiator (e.g., in an amount of from 0.1 to 1 or 5 percent by weight), optionally at least one dye (e.g., in an amount of 0.001 or 0.01 to 1 or 5 percent by weight), and optionally at least one filler (e.g., in an amount of 0.01 or 0.1 to 20 or 50 percent by weight). 
     
     
         20 . The polymerizable liquid composition of  claim 17 , wherein said composition further comprises a monomer compound of formula II: 
       
         
           
           
               
               
           
         
         wherein: 
         B 1  is a reactive blocking group (e.g., comprising acrylates, methacrylates, α-olefins, N-vinyls, acrylamides, methacrylamides, styrenics, epoxides, thiols, 1,3-dienes, vinyl halides, acrylonitriles, vinyl esters, maleimides, vinyl ethers, and ethylenically unsaturated end groups); 
         B 2  is a volatile blocking group (e.g., comprising ketoximes, amides, imides, imidazoles, oximes, pyrazoles, alcohols, phenols, sterically-hindered amines, lactams, succinimides, triazoles, and phthalimides); and 
         R 1  is an aliphatic, aromatic or mixed aliphatic and aromatic group (e.g., a straight chain or branched C 1 -C 15 alkyl or aromatic group).