Patent ID: 7683152

Claim:
A partial block polyimide-polysiloxane copolymer comprising repeat unit structures having the following structural formulae (2) and (8): wherein X is at least one aromatic ring-containing tetravalent organic radical selected from the group consisting of: Y 2 is a divalent organic radical having the structural formula (3), Y 3 is a divalent organic radical having the structural formula (9), Y 2 and Y 3 are contained in the copolymer in molar amounts y 2 and y 3 , respectively, which satisfy y 2 /(y 2 +y 3 )=0.5 to 0.01 and y 3 /(y 2 +y 3 )=0.5 to 0.99, m is a weight average value of 9.1 to 50, j is a weight average value of 8.8 to 50, wherein R 1 is a divalent organic radical of 3 to 9 carbon atoms, R 2 and R 3 are each independently a substituted or unsubstituted, monovalent hydrocarbon radical of 1 to 8 carbon atoms, and n is an integer of 1 to 150, wherein A is a radical selected from the following group [9a]: group [9a] B is a radical selected from the following group [9b]: group [9b] R is each independently a hydrogen atom, halogen atom or substituted or unsubstituted, monovalent hydrocarbon radical of 1 to 8 carbon atoms, and k is a natural number of 1 to 5.