Liquid formulation for reaction injection molding and manufacturing method thereof

A method for manufacturing a liquid formulation for reaction injection molding for polymerizing a norbornene-based monomer in the presence of a metathesis polymerization catalyst comprising tungsten as a center metal, the liquid formulation comprising a norbornene-based monomer, provided that in case where the norbornene-based monomer includes exo-dicyclopentadiene, a content of exo-dicyclopentadiene is from 0 to 2% by mass of the norbornene-based monomer, an activator of the catalyst, and an ether compound wherein the ether compound is dipropyleneglycol dimethyl ether,

• the method comprising the step of mixing a liquid mixture comprising the ether compound and the activator of the catalyst with the norbornene-based monomer,
• wherein the norbornene-based monomer is selected from the group consisting essentially of norbornene, norbornenes having an alkyl group, norbornenes having an alkenyl group, norbornenes having an aromatic ring, norbornenes having a polar group including an oxygen atom, dicyclopentadiene, methyldicyclopentadiene, tricyclo[5.2.1.02,6]deca-8-ene, tetracyclo[9.2.1.02,10.03,8]tetradeca-3,5,7,12-tetraene, tetracyclo[10.2.1.02,11.04,9] pentadeca-4,6,8,13-tetraene, tricyclopentadiene, tetracyclododecene, tetracyclododecenes having an aromatic ring, tetracyclododecenes having a substituent including an oxygen atom, tetracyclododecenes having a substituent including a halogen atom, tetracyclododecenes having a substituent including a silicon atom, hexacycloheptadecene, hexacycloheptadecenes having an alkyl group, hexacycloheptadecenes having a double bond outside the ring, hexacycloheptadecenes having an aromatic ring, hexacycloheptadecenes having a substituent including an oxygen atom, hexacycloheptadecenes having a substituent including a halogen atom, and hexacycloheptadecenes having a substituent including a silicon atom.