Radiation Polymerizable Composition for Optical Fiber Primary Coating

The patent changes the chemical structure parameters of the urethane oligomer by introducing vinyl groups at terminal positions and incorporating maleimide structures. These parameter changes enable the oligomer to undergo rapid photopolymerization while maintaining the flexibility required for optical fiber primary coating layers, thus resolving the contradiction between curing rate and flexibility.

The patent creates a composite resin composition by combining specifically structured vinyl-containing urethane oligomers with maleimide compounds and photopolymerization initiators. This composite material achieves both fast curing rate through the maleimide-enhanced polymerization and maintained flexibility through the urethane oligomer's molecular structure with terminal vinyl groups.

By modifying the urethane oligomer structure to include terminal vinyl groups and maleimide moieties, the patent enables faster photopolymerization kinetics without sacrificing the elastic properties needed for flexibility. This parameter change allows high-speed curing that improves productivity while preserving the coating layer's ability to protect the optical fiber.

The maleimide compound acts as an intermediary that accelerates the photopolymerization process. It facilitates rapid crosslinking of the vinyl groups on the urethane oligomer, enabling fast curing for improved productivity while the urethane oligomer's base structure maintains the flexibility required for ease of operation.