Patent ID: 7171103

Claim:
An inner primary coating composition having: (a) an in-situ modulus (after cure) of less than 0.6 MPa; (b) a cure dose to attain 95% of the maximum attainable modulus of less than 0.65 J/cm 2 ; and (c) a modulus retention ratio (after cure) of at least 0.6 after hydrolytic aging; wherein said composition comprises: (i) 20–98 wt. % relative to the total weight of the composition of a radiation curable urethane (meth)acrylate oligomer having polyether polyol backbone; (ii) 0–80% wt. % relative to the total weight of the composition of one or more reactive diluents; (iii) 0.1–20 wt. % relative to the total weight of the composition of one or more photoinitiators; and (iv) 0–5 wt. % relative to the total weight of the composition of additives.