Blocking groups for light polymerizable resins useful in additive manufacturing

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.

A prepolymer compound of formula I:

• wherein:
• B1 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);
• B2 is a volatile blocking group (e.g., comprising ketoximes, amides, imides, imidazoles, oximes, pyrazoles, alcohols, phenols, sterically-hindered amines, lactams, succinimides, triazoles, and phthalimides);
• R1 and R2 are independently selected from the group comprising an aliphatic, aromatic or mixed aliphatic and aromatic group
• X is O, S, or NR3, wherein R3 is H or a straight chain or branched C1-C10 alkyl group;
• Z is a polymeric organic group (e.g., (CH2)3);
• n is an integer in the range of 1 to 150;
• and
• m is an integer in the range of 1 to 100.