Process for making submicron stable latexes of hydrogenated block copolymers
AssigneeShell Oil Company
InventorsDavid M. Austgen, Jr., Jeffrey G. Southwick, Bing Yang
Life of this patent
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Abstract
This invention is a process for producing stable polymer emulsions and latexes with an average particle size of less than one micron. The polymers are hydrogenated block copolymers of conjugated dienes and vinyl aromatic hydrocarbons which may or may not contain polar functionality. The process comprises making a polymer cement of the polymer and a blend of a non-aromatic solvent for the vinyl aromatic hydrocarbon block which is immiscible with water and a non-aromatic cosolvent, emulsifying the polymer cement by adding it to an aqueous phase containing at least one surfactant and removing the solvent, cosolvent and excess water.
Claims14
A process for producing stable polymer cement emulsions with an average particle size of less than two microns, which comprises
- (a) making a polymer cement of a hydrogenated block copolymer of a conjugated diene and a vinyl aromatic hydrocarbon having an overall peak molecular weight as determined by gel permeation chromatography of 25,000 or more and a vinyl aromatic hydrocarbon block peak molecular weight as determined by gel permeation chromatography of 5000 or more and a blend of from 75 to 85 percent by weight of a non-aromatic solvent for the vinyl aromatic hydrocarbon block which has a solubility parameter in the range from 8.3 to 9.5, is a poor solvent for the conjugated diene blocks, and is immiscible with water, and from 15 to 25 percent by weight of the blend of a non-aromatic cosolvent having a solubility parameter of 7.0 to 8.2;
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- (b) emulsifying the polymer cement at an aqueous phase to cement weight ratio of from 10:1 to 1:3 by combining it with an aqueous phase containing from 0.1 to 10 weight percent of the aqueous phase of one or more surfactants.
A process for producing stable polymer cement emulsions with an average particle size of less than two microns, which comprises:
- (a) making a polymer cement of a block copolymer of a conjugated diene and a vinyl aromatic hydrocarbon having an overall peak molecular weight as determined by gel permeation chromatography of 25,000 or more and a vinyl aromatic hydrocarbon block molecular weight of 5000 or more which has been functionalized with polar groups and a blend of from 75 to 95 percent by weight of a non-aromatic solvent for the vinyl aromatic hydrocarbon block which has a solubility parameter in the range from 8.3 to 9.5, is a poor solvent for the conjugated diene blocks, and is immiscible with water, and from 5 to 25 percent by weight of the blend of a non-aromatic cosolvent having a solubility parameter of 7.0 to 8.2;
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- (b) emulsifying the polymer cement at an aqueous phase to cement weight ratio of from 10:1 to 1:3 by combining it with an aqueous phase containing from 0.1 to 10 weight percent of the aqueous phase of one or more surfactants.
Dependencies are inferred from the claim text.