Preformed stabilizers useful for the production of polymer polyols and polymer polyols produced therefrom
View Patent ↗Preformed stabilizers useful for the production of low viscosity, high solids polymer polyols are produced by free-radical polymerization of: (a) at least one ethylenically unsaturated macromolecule or macromer with (b) at least three different ethylenically unsaturated monomers in the presence of (c) at least one free-radical polymerization initiator, and, optionally, (d) a liquid diluent, and, optionally, (e) a chain transfer agent.
1. A preformed stabilizer formed by free-radical polymerization of a mixture comprising:
(a) at least one ethylenically unsaturated macromolecule or macromer,
with
(b) at least three different radically polymerizable ethylenically unsaturated monomers,
in the presence of
(c) at least one free-radical polymerization initiator,
and, optionally,
(d) a liquid diluent,
and, optionally,
(e) a chain transfer agent.
2. The preformed stabilizer of claim 1 in which (b) includes acrylonitrile and/or styrene.
3. The preformed stabilizer of claim 1 in which (b) includes a mixture of styrene and acrylonitrile in a weight ratio of 80:20 to 20:80.
4. The preformed stabilizer of claim 3 in which the styrene and acrylonitrile constitute at least 20% by weight of the total weight of (b).
5. The preformed stabilizer of claim 1 in which (b) includes an ethylenically unsaturated monomer containing a hydroxyl group.
6. The preformed stabilizer of claim 1 in which (b) includes at least one ethylenically unsaturated monomer selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate.
7. The preformed stabilizer of claim 4 in which (b) further includes at least one ethylenically unsaturated monomer selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate.
8. The preformed stabilizer of claim 1 in which (c) is selected from the group consisting of one or more peroxide initiators, one or more azo initiators and mixtures thereof.
9. The preformed stabilizer of claim 7 in which (c) is selected from the group consisting of one or more peroxide initiators, one or more azo initiators and mixtures thereof.
10. The preformed stabilizer of claim 1 in which (d) is selected from the group consisting of a mono-ol, a polyol, a hydrocarbon, an ether and mixtures thereof.
11. The preformed stabilizer of claim 9 in which (d) is selected from the group consisting of a mono-ol, a polyol, a hydrocarbon, an ether and mixtures thereof.
12. The preformed stabilizer of claim 1 in which (e) is selected from the group consisting of methanol, isopropanol, ethanol, tert-butanol, toluene, ethylbenzene, triethylamine, dodecylmercaptan, octadecylmercaptan, carbon tetrachloride, carbon tetrabromide, chloroform, and methylene chloride.
13. A continuous process for preparing a polymer polyol comprising:
free-radically polymerizing:
(1) a base polyol,
(2) the preformed stabilizer of claims 1 ,
and
(3) at least one ethylenically unsaturated monomer,
in the presence of
(4) at least one free-radical polymerization initiator comprising an azo compound that is free of nitrile groups,
and, optionally,
(5) a polymer control agent, and optionally
(6) a chain transfer agent.
14. A polymer polyol produced by the process of claim 13 .