Radiation-curable optical glass fiber coating compositions, coated optical glass fibers, and optical glass fiber assemblies
Optical fiber coatings are disclosed having excellent ribbon stripping and adhesion behavior. The coatings are radiation-curable. The excellent stripping and adhesion behavior can be achieved by several means which include by use of additives, by use of radiation-curable oligomers having higher molecular weight, or by use of coatings having certain thermal properties. Combination of means can be employed. Stripping behavior can be measured by crack propagation and fiber friction measurements.
1 . A radiation-curable inner primary coating composition for an optical glass fiber comprising an oligomer having at least one functional group capable of polymerizing under the influence of radiation, said composition after radiation cure having the combination of properties of:
(a) a fiber pull-out friction of less than 20 g/mm at stripping temperature;
(b) a crack propagation of greater than 1.0 mm at stripping temperature;
(c) a glass transition temperature of below 10° C.; and
(d) sufficient adhesion to said glass fiber to prevent delamination in the presence of moisture and during handling.
2 - 72 . (canceled)