Patent ID: 6166107
Filing Date: 2000-12-26
Classification: B29C,B29D

Abstract:
A method for producing an optical rod-shaped graded-index polymer preform by making the composition of the preform near the core differ from the composition of the shell of the preform by polymerization with rotation of a mixture containing the starting substances, characterized 1) in that a mixture comprising various monomers is rotated and that after achieving a distribution of said monomers, the polymerization is carried out with rotation of the mixture, or 2) in that a monomer and thermoplastic polymer-containing mixture, whereby said monomer is different from the monomer from which said polymer has been prepared, is rotated and that, after achieving a distribution of said monomer and polymer, the monomer present in said mixture is subsequently polymerized with rotation, in which in both cases 1) and 2) the rotation is carried out with a diameter dependent rotation velocity, represented by the following general equation:rpm>10,000 d.sup.-0.5wherein:rpm=rotation velocity, revolutions per minuted=diameter of the preform (cm).