Patent ID: 6951700

Claim:
A method of carrying out a stereolithographic process to produce a three-dimensional object, said method comprising the steps of: (i) supporting on a surface compound A, which comprises a group of sub-formula (I) where R 1 is CR a′ where R a′ is hydrogen or alkyl, and R 6 is a bond or R 1 and R 6 together form an electron withdrawing group; R 2 and R 3 are independently selected from (CR 7 R 8 ) n , or a group CR 9 R 10 , CR 7 R 8 CR 9 R 10 or CR 9 R 10 CR 7 R 8 where n is 0, 1 or 2, R 7 and R 8 are independently selected from hydrogen or alkyl, and either one of R 9 or R 10 is hydrogen and the other is an electron withdrawing group, or R 9 and R 10 together form an electron withdrawing group, and R 4 and R 5 are independently selected from C, CH or CR 11 where R 11 is an electron withdrawing group; the dotted lines indicate the presence or absence of a bond, and X 1 is a group CX 2 X 3 where the dotted line bond to which it is attached is absent and a group CX 2 where the dotted line bond to which it is attached is present, Y 1 is a group CY 2 Y 3 where the dotted line bond to which it is attached is absent and a group CY 2 where the dotted line bond to which it is attached is present, and X 2 , X 3 , Y 2 and Y 3 are independently selected from hydrogen and fluorine; provided that at least one of (a) R 1 and R 6 or (b) R 2 and R 3 or (c) R 4 and R 5 includes an electron withdrawing group that activates the cyclopolymerization reaction when irradiated, optionally in the presence of a photoinitiator; (ii) irradiating said compound to produce a first layer of hardened polymer therefrom; and then (iii) supporting further compound on the formed polymer and irradiating it to produce a successive hardened layer of polymer to produce the desired three-dimensional object.