Foam test for double metal cyanide-catalyzed polyols
AssigneeArco Chemical Technology, L.P.
InventorsJose F. Pazos, Veril C. Jividen
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Abstract
Double metal cyanide-catalyzed polyols are made by an improved process in which a starter is continuously added during polymerization of the epoxide. The process includes a continuously added starter (S.sub.c), and optionally, an initially charged starter (S.sub.i). The continuously added starter comprises at least about 2 equivalent percent of the total starter used. The process enables the use of water and low molecular weight polyol starters in DMC-catalyzed polyol synthesis. In addition, the process gives polyether polyols having reduced levels of high molecular weight polyol tail, which can adversely affect polyurethane foam processing.
Claims10
A foam test for polyols which is sensitive to the presence of high molecular weight polyol tail species in the polyols and which comprises:
- (a) preparing a one-shot polyurethane foam from about 100 parts of a polyol to be tested, about 6.5 parts of water, about 15 parts of dichloromethane, about 0.1 parts of a blowing catalyst which comprises 70 wt. % of bis(2-dimethylaminoethyl)ether and 30 wt. % of dipropylene glycol, about 0.25 parts of a urethane catalyst which comprises 97 wt. % of stannous octoate and 3 wt. % of 2-ethylhexanoic acid, about 0.5 parts of a polyalkylene oxide-methylsiloxane copolymer surfactant, and about 78 parts of toluene diisocyanate;
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- (b) after the foam rises and cures, measuring the degree of foam settling or collapse;
- wherein foam collapse indicates the presence of more than about 200 ppm of high molecular weight polyol tail in the tested polyol, said tail having a number average molecular weight greater than about 100,000 as measured by gel permeation chromatography.
A foam test for polyols which is sensitive to the presence of high molecular weight polyol tail species in the polyols and which comprises:
- (a) preparing a one-shot polyurethane foam from about 100 parts of a polyol to be tested, about 6.5 parts of water, about 15 parts of dichloromethane, about 0.1 parts of a blowing catalyst which comprises bis(2-dimethylaminoethyl)ether, about 0.25 parts of a urethane catalyst which comprises stannous octoate, about 0.5 parts of a silicone surfactant, and about 78 parts of toluene diisocyanate;
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- (b) after the foam rises and cures, measuring the degree of foam settling or collapse;
- wherein foam collapse indicates the presence of more than about 200 ppm of high molecular weight polyol tail in the tested polyol, said tail having a number average molecular weight greater than about 100,000 as measured by gel permeation chromatography.
A process for making a polyether polyol, said process comprising:
- (a) polymerizing an epoxide in the presence of a double metal cyanide (DMC) catalyst, a continuously added starter (S.sub.c), and optionally, an initially charged starter (S.sub.i), said S.sub.c comprising at least about 2 eq. % of the total starter used, wherein the S.sub.c and the epoxide are continuously added to the reactor during step (a) to produce a polyol intermediate;
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- (b) reacting the polyol intermediate with additional epoxide in the absence of a continuously added starter to produce a polyether polyol.
A process for making a polyether diol, said process comprising:
- (a) polymerizing propylene oxide in the presence of a zinc hexacyanocobaltate catalyst, a continuously added starter (S.sub.c), and optionally, an initially charged starter (S.sub.i), said S.sub.c comprising at least about 2 eq. % of the total starter used, wherein the S.sub.c and the propylene oxide are continuously added to the reactor during step (a) to produce a polyether diol intermediate;
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- (b) reacting the diol intermediate with additional propylene oxide in the absence of a continuously added starter to produce a polyether diol.
Dependencies are inferred from the claim text.