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US 10,307,752 B2Granted
Method for producing polymer, and polymer
AssigneeMitsubishi Chemical Corporation
InventorsSeiji Tsuchiya, Shinichi Maeda
Life of this patent
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Abstract
A method for producing a polymer of the present invention includes the following steps (a) and (b): step (a): producing a polymer in the presence of an acid or base catalyst; and step (b): contacting a solution containing the polymer obtained in step (a) to a mixed resin of an anion-exchange resin and a cation-exchange resin.
Claims11
A method for producing a polymer, the method comprising:
- producing a polymer by polymerizing monomers in the presence of an acid catalyst, terminating the polymerization using a basic compound and attaching a crosslinking agent to a side chain of the polymer;
- subsequently contacting a solution comprising the polymer with a mixed resin of an anion-exchange resin and a cation-exchange resin, to reduce residual metal impurities, acidic impurities, and basic impurities to a level such that a sum of concentrations of acidic and basic impurities is 50 ppm or lower;
- and metal impurity concentrations of sodium, potassium, calcium and iron are each 80 ppb or lower,
- subsequently passing the solution comprising the polymer through a filter that does not comprise a strongly acidic ion-exchange group but comprises a charge control agent for generating zeta potential,
- wherein the acid catalyst is p-tolulenesulfonic acid, and
- a mass ratio of the anion exchange resin to the cation-exchange resin is from 60/40 to 99/1.
3 more elements
A method for producing a polymer, comprising:
- producing a polymer by polymerizing monomers in the presence of a base catalyst, terminating the polymerization using an acidic compound, and attaching a crosslinking agent to a side chain of the polymer;
- subsequently contacting a solution comprising the polymer with a mixed resin of an anion-exchange resin and a cation-exchange resin, to reduce residual metal impurities, acidic impurities, and basic impurities to a level such that a sum of concentrations of acidic and basic impurities is 50 ppm or lower;
- and metal impurity concentrations of sodium, potassium, calcium and iron are each 80 ppb or lower, and
- subsequently passing the solution comprising the polymer through a filter that does not comprise a strongly acidic ion-exchange group but comprises a charge control agent for generating zeta potential,
- wherein the base catalyst is a tertiary amine.
2 more elements
A method for producing a polymer, the method comprising:
- producing a polymer by polymerizing monomers in the presence of a base catalyst, terminating the polymerization using an acidic compound, and attaching a crosslinking agent to a side chain of the polymer;
- and
- subsequently contacting a solution comprising the polymer with a mixed resin of an anion-exchange resin and a cation-exchange resin, to reduce residual metal impurities, acidic impurities, and basic impurities to a level such that a sum of concentrations of acidic and basic impurities is 50 ppm or lower;
- and metal impurity concentrations of sodium, potassium, calcium and iron are each 80 ppb or lower,
- wherein the base catalyst is a tertiary amine.
2 more elements
Dependencies are inferred from the claim text.