Patent ID: 8394899
Filing Date: 2013-03-12
Classification: C08G,C08L

Abstract:
1. A method for producing a polymer polyol (Ia), the method comprising: a first step of polymerizing a monomer-containing mixture liquid (A1) comprising a polyol (a), an ethylenically unsaturated monomer (d), a radical polymerization initiator (k), and a dispersant (e), thereby obtaining a polymer polyol intermediate (B1); and an (i+1)th step of polymerizing a monomer-containing mixture liquid (Ai+1) comprising a polyol (a), an ethylenically unsaturated monomer (d), a radical polymerization initiator (k), a dispersant (e), and a base polymer polyol (hi) that is an intermediate (Bi), thereby obtaining a polymer polyol intermediate (Bi+1), where i is an integer incremented from 1 to n−1 whereby this step is repeated n−1 times, wherein the polymer polyol intermediate (Bi+1) is to be used as a base polymer polyol (hi+1) in a next step whereby the ethylenically unsaturated monomer (d) is polymerized likewise, wherein a total number n of repetition times is 3 to 7, each of the steps of the polymerizing the monomer-containing mixture liquid (A1) and the monomer-containing mixture liquid (Ai+1) is a one-step polymerization method, in which a mixture obtained by mixing (a), (d), (e), and optionally a diluent (c) is heated to a polymerization temperature and thereafter the radical polymerization initiator (k) is added to the mixture for polymerization, each concentration of the ethylenically unsaturated monomer (d) in the monomer-containing mixture liquids (A1) and (Ai+1) before the initiation of polymerization in each step is 7 mass % to 25 mass %, a polymer content in the base polymer polyol (hi) is 7 mass % to 50 mass %, and a polymer content in a polymer polyol (Ia) obtained finally is 30 mass % to 65 mass %.