Optical glass fiber with a primary coating of acrylic acid ester groups-containing organo-polysiloxanes

Claim 1

An optical glass fiber having a primary coating, comprising organo-polysiloxanes having alkyl groups bound to silicon and containing acrylic acid ester groups, where the organo-polysiloxanes are liquid at the application temperature and are polymerizable by high-energy radiation, wherein the organo-polysiloxanes are compounds having the general formula ##STR11## where the following applies: R 1 is methyl, R 2 is a linear-chain, branched, or cyclic alkyl residue with 5 to 18 carbon atoms, which can optionally be substituted with halogen, R 3 is an aralkyl of the following structure: ##STR12## where any R 4 is any substituent selected from the group consisting of hydrogen, alkyl with 1 to 12 carbon atoms and halogen, and R 5 is alkylene with 1 to 8 carbon atoms (linear-chain or branched), any Q is any member selected from the group consisting of: multiple acrylic and methacrylic acid esters of a polyol bound through the oxygen atom of a hydroxyl group minus the hydrogen atom to silicon, the polyol selected from the group consisting of pentaerythritol, trimethylolethane, trimethylolpropane, and glycerin; dimers of said esters; and oxyalkylene derivatives of said esters where the polyol has been converted so as to have 1 to 10 units of at least one of oxyethylene and oxypropylene, a is greater than or equal to 0.9 and b plus c is less than or equal to 0.9, b, c are 0 to 1.1, b plus c is greater than or equal to 0.1, Σa,b,c is 1.8 to 2.2, and d is 0.001 to 1.6, and wherein the organo-polysiloxanes contain a maximum of 4 percent by weight of fractions volatile at 130° C./30 mbar.