Patent ID: 6770404
Filing Date: 2004-08-03
Classification: G03F

Abstract:
An ultraviolet transparent material exhibiting an absorbance/micron (A/micrometer) &lE;1 at wavelengths from 187-260 nm comprising: amorphous vinyl copolymers of CX2&boxH;CH2, wherein X is â€”F or â€”CF3 and up to 25 mole % of one or more monomers CRaRb&boxH;CRcRd where the CRaRb&boxH;CRcRd enters the copolymer in approximately random fashion or 40 to 60 mole % of one or more monomers CRaRb&boxH;CRcRd in the case where the CRaRb&boxH;CRcRd enters the copolymer in approximately alternating fashion where each of Ra, Rb, and Rc is selected independently from H or F and where Rd is selected from the group consisting of â€”F, â€”CF3, â€”ORf where Rf is CnF2n+1 with n=1 to 3, â€”OH (when Rc&boxH;H), and Cl (when Ra, Rb, and Rc&boxH;F), with the proviso that not all of Ra-d can be F.