The invention relates to a method to reduce or prevent agglomeration of polyisobutylene particles in aqueous media by LCST compounds and highly pure polyisobutylenes obtained thereby. The invention further relates to polyisobutylene products comprising the same or derived therefrom.

The invention relates to a method to reduce or prevent agglomeration of polyisobutylene particles in aqueous media by LCST compounds and highly pure polyisobutylenes obtained thereby. The invention further relates to polyisobutylene products comprising the same or derived therefrom.

A vinylidene fluoride copolymer composition having stable dispersibility in a dispersion medium over a long period of time, the composition having a melting temperature of 140? C. or lower, a reversing heat flow of the composition has endothermic peaks having an amount of enthalpy of fusion of 2 J/g or more, and an absolute value of a difference between a temperature showing a largest endothermic peak among the endothermic peaks and the melting temperature of the composition is 10? C. or lower. When a dispersion containing butyl butyrate and the vinylidene fluoride copolymer composition (vinylidene fluoride content rate of 10 mass %) is left to stand for 20 hours, a content rate of the vinylidene fluoride copolymer composition in an upper 20 vol % of the dispersion after the dispersion is left to stand is 4.0 mass % or more and 10 mass % or less.

A vinylidene fluoride copolymer composition having stable dispersibility in a dispersion medium over a long period of time, the composition having a melting temperature of 140? C. or lower, a reversing heat flow of the composition has endothermic peaks having an amount of enthalpy of fusion of 2 J/g or more, and an absolute value of a difference between a temperature showing a largest endothermic peak among the endothermic peaks and the melting temperature of the composition is 10? C. or lower. When a dispersion containing butyl butyrate and the vinylidene fluoride copolymer composition (vinylidene fluoride content rate of 10 mass %) is left to stand for 20 hours, a content rate of the vinylidene fluoride copolymer composition in an upper 20 vol % of the dispersion after the dispersion is left to stand is 4.0 mass % or more and 10 mass % or less.

A process for producing superabsorbents, comprising polymerization of a monomer solution and thermal surface postcrosslinking, wherein the monomer solution comprises at least 0.75% by weight of a hydroxyphosphonic acid or salts thereof, calculated on the basis of the total amount of monomer used, and at least 0.09% by weight of aluminum cations, calculated on the basis of the total amount of polymer particles used, is added to the polymer particles before, during or after the thermal surface postcrosslinking.

A process for producing superabsorbents, comprising polymerization of a monomer solution and thermal surface postcrosslinking, wherein the monomer solution comprises at least 0.75% by weight of a hydroxyphosphonic acid or salts thereof, calculated on the basis of the total amount of monomer used, and at least 0.09% by weight of aluminum cations, calculated on the basis of the total amount of polymer particles used, is added to the polymer particles before, during or after the thermal surface postcrosslinking.

A solvent-removing apparatus according to an embodiment includes a tank body accommodating an emulsion including first source material in a continuous phase and second source material in a dispersed phase, a fluid supply unit for supplying fluid into the tank body to cause the emulsion to circulate, and a discharge unit for discharging the gas in the tank body to the outside.

The present invention relates to a commercial reaction process for the selective oligomerization reaction of ethylene, and a method for efficiently removing reaction heat to be generated in a reaction and regulating the temperature of the reactor and, more specifically, to an oligomerization reaction process of ethylene by circulating a liquid mixture in the reactor, separating unreacted ethylene from this circulation flow by an apparatus for separating unreacted ethylene from the circulation flow, and then cooling the remaining mixture and reintroducing it to the reactor, thereby removing the reaction heat in the reactor and allowing temperature control.

A dried rheology modifier composition comprises a swellable emulsion polymer and a water soluble support polymer. In one embodiment the swellable emulsion polymer is polymerized in the presence of the water soluble support polymer. In one embodiment the swellable emulsion polymer is blended with the water soluble support polymer. The drying can be accomplished by spray drying, resulting in a non-tacky powder having good shelf life. The dried rheology modifiers can be subjected to a further heat treatment which can result in a rheology modifier that imparts a short flow characteristic to product formulations. The swellable emulsion polymer can be alkali swellable or acid swellable. The water soluble support polymer can be a polysaccharide or a derivative thereof, or a polyvinyl acetate or derivative thereof.

A dried rheology modifier composition comprises a swellable emulsion polymer and a water soluble support polymer. In one embodiment the swellable emulsion polymer is polymerized in the presence of the water soluble support polymer. In one embodiment the swellable emulsion polymer is blended with the water soluble support polymer. The drying can be accomplished by spray drying, resulting in a non-tacky powder having good shelf life. The dried rheology modifiers can be subjected to a further heat treatment which can result in a rheology modifier that imparts a short flow characteristic to product formulations. The swellable emulsion polymer can be alkali swellable or acid swellable. The water soluble support polymer can be a polysaccharide or a derivative thereof, or a polyvinyl acetate or derivative thereof.