A method of preparing a superabsorbent polymer, which enables the preparation of the superabsorbent polymer exhibiting an improved absorption rate while maintaining excellent absorption performances is provided. The method of preparing the superabsorbent polymer includes carrying out a crosslinking polymerization of a water-soluble ethylene-based unsaturated monomer having acidic groups which are at least partially neutralized, in the presence of an internal crosslinking agent having a predetermined chemical structure to form a water-containing gel polymer, gel-pulverizing the water-containing gel polymer, drying, pulverizing, and size-sorting the gel-pulverized water-containing gel polymer to form a base polymer powder, and carrying out a surface crosslinking of the base polymer powder by a heat treatment in the presence of a surface crosslinking agent, wherein the gel-pulverizing is carried out by extruding the water-containing gel polymer through a porous plate having a plurality of holes using a screw extruder mounted inside a cylindrical pulverizer under a condition that a chopping index is 28 (/s) or more.

The method produces hollow particles which have a high void ratio, which can reduce the residual amount of a sparingly water-soluble solvent used in the production process, and which are less likely to collapse. The method for producing hollow particles which comprise a shell and a hollow portion and which have a void ratio of 50% or more and 90% or less, wherein a suspension treatment of a mixture liquid containing a polymerizable monomer for shell, a polar resin, a hydrocarbon solvent, a sparingly water-soluble inorganic metal salt as a dispersant, and an aqueous medium is carried out to prepare a suspension in which droplets of a monomer composition containing the polymerizable monomer for shell, the polar resin and the hydrocarbon solvent are dispersed in the aqueous medium; a polymerization reaction of the suspension is carried out; and the hydrocarbon solvent is removed from the obtained hollow particles.

The method produces hollow particles which have a high void ratio, which can reduce the residual amount of a sparingly water-soluble solvent used in the production process, and which are less likely to collapse. The method for producing hollow particles which comprise a shell and a hollow portion and which have a void ratio of 50% or more and 90% or less, wherein a suspension treatment of a mixture liquid containing a polymerizable monomer for shell, a polar resin, a hydrocarbon solvent, a sparingly water-soluble inorganic metal salt as a dispersant, and an aqueous medium is carried out to prepare a suspension in which droplets of a monomer composition containing the polymerizable monomer for shell, the polar resin and the hydrocarbon solvent are dispersed in the aqueous medium; a polymerization reaction of the suspension is carried out; and the hydrocarbon solvent is removed from the obtained hollow particles.

Disclosed are a copolymerized PVDF resin for lithium battery binders and its preparation method. 300 to 600 parts of deionized water, 0.04 to 0.25 part of a pH buffer regulator, 85 to 99.5 parts of a vinylidene fluoride (VDF) monomer, 0.5 to 15 parts of a comonomer, 0.3 to 3 parts of a metallocene synergist, 0.2 to 1.0 part of an initiator, 0.08 to 0.35 part of a dispersant react at 40 to 65° C., 5.5-8.0 Mpa. At the end of the reaction, the unreacted monomers are recovered, and then the operations of washing, filtering, and drying are carried out to obtain the copolymerized PVDF resin. For the copolymerized PVDF resin for lithium battery binders, the binding of PVDF resin to a positive electrode active material and current collector is improved, and the rotational viscosity of the NMP solution and the preparation and dispersion requirements for PVDF resin slurry are reduced.

Disclosed are a copolymerized PVDF resin for lithium battery binders and its preparation method. 300 to 600 parts of deionized water, 0.04 to 0.25 part of a pH buffer regulator, 85 to 99.5 parts of a vinylidene fluoride (VDF) monomer, 0.5 to 15 parts of a comonomer, 0.3 to 3 parts of a metallocene synergist, 0.2 to 1.0 part of an initiator, 0.08 to 0.35 part of a dispersant react at 40 to 65° C., 5.5-8.0 Mpa. At the end of the reaction, the unreacted monomers are recovered, and then the operations of washing, filtering, and drying are carried out to obtain the copolymerized PVDF resin. For the copolymerized PVDF resin for lithium battery binders, the binding of PVDF resin to a positive electrode active material and current collector is improved, and the rotational viscosity of the NMP solution and the preparation and dispersion requirements for PVDF resin slurry are reduced.

A modified aluminum nitride particle comprises an aluminum nitride core and a shell surrounding the aluminum nitride core. The shell comprises a crosslinked organic polymer. Methods of making the modified aluminum nitride particle by admicellar polymerization are also disclosed.

A method for predicting physical properties of a polyethylene resin is provided, which can reliably predict a proper charging ratio of a crosslinking agent in the production process of a low density crosslinked polyethylene resin, and the physical properties of the polyethylene resin achieved therefrom. A method for producing a polyethylene resin by applying the same method is also provided.

A method for predicting physical properties of a polyethylene resin is provided, which can reliably predict a proper charging ratio of a crosslinking agent in the production process of a low density crosslinked polyethylene resin, and the physical properties of the polyethylene resin achieved therefrom. A method for producing a polyethylene resin by applying the same method is also provided.

This invention relates to a a one-step process for making a polymer composite suspension for coating plastic films characterized in that a first polymer is synthesized in-situ optionally in the presence of other polymers and in the presence of clay. Preferably the polymer composite suspension comprises a) 1.0 to 11.0 wt % of clay or silane modified clay, b) 0.1 to 10.0 wt % of poly (acrylic acid), which is a copolymer of acrylic acid (AA) with at least one other monomer selected from 2-ethylhexyl acrylate (ERA), β-carboxyethyl acrylate (β-CEA), methacrylamidoethyl ethylene urea (WAM II) and ethoxylated behenyl methacrylate (β-EHA), c) 1.0 to 15.0 wt % of other polymers, preferably poly (vinyl alcohol) and d) 70 to 97 wt % of water or mixture of water with 2-propanol. The coating films made from the suspensions show good barrier capabilities against water vapor and oxygen can be used to make barrier layers on or within plastic films for packaging applications. The invention also relates to methods for making silane modified clay usable in the process for making the suspensions.

This invention relates to a a one-step process for making a polymer composite suspension for coating plastic films characterized in that a first polymer is synthesized in-situ optionally in the presence of other polymers and in the presence of clay. Preferably the polymer composite suspension comprises a) 1.0 to 11.0 wt % of clay or silane modified clay, b) 0.1 to 10.0 wt % of poly (acrylic acid), which is a copolymer of acrylic acid (AA) with at least one other monomer selected from 2-ethylhexyl acrylate (ERA), β-carboxyethyl acrylate (β-CEA), methacrylamidoethyl ethylene urea (WAM II) and ethoxylated behenyl methacrylate (β-EHA), c) 1.0 to 15.0 wt % of other polymers, preferably poly (vinyl alcohol) and d) 70 to 97 wt % of water or mixture of water with 2-propanol. The coating films made from the suspensions show good barrier capabilities against water vapor and oxygen can be used to make barrier layers on or within plastic films for packaging applications. The invention also relates to methods for making silane modified clay usable in the process for making the suspensions.