Epoxy sizing emulsion its preparation and application of the structurally modified polyurethane

The present invention relates to a urethane-modified epoxy resin structure sizing emulsion having a composition comprising: a polyurethane structurally modified epoxy resin composition 55 ~ 78wt%, surfactant 20 ~ 40wt%, the antioxidant 0.5 ~ 2wt %, leveling agent 1 ~ 2wt%, and antifreeze 0.5 ~ 1wt%; preparation comprising: bisphenol A type epoxy resin vacuum dehydration until no bubbles, the isocyanate was added after cooling to prepare an epoxy resin composition ; mass fraction of the above surfactants and antioxidants homogeneous mixing in an autoclave, and then gradually adding deionized water, antifreeze agents and leveling agents, i.e., too. Epoxy sizing agent emulsions prepared according to the present invention, carbon fibers having good bundling properties, wear resistance and toughness, and abrasion resistance and which is easy to cluster freely adjusted by the amount of the isocyanate component; the carbon fibers and sizing agent is not required adding sizing agent and field in the late secondary mixing, use good stability, good wettability of carbon fiber sizing, which will help stabilize the carbon fiber industrial production.