The present invention provides a dispersion stabilizer for suspension polymerization that, when used for suspension polymerization of a vinyl compound, provides excellent polymerization stability, and can produce a vinyl polymer having a reduced number of coarse particles, and a reduced number of fisheyes when molded into a sheet form. The present invention also provides a method therewith. The present invention relates to a dispersion stabilizer for suspension polymerization of a vinyl compound, the dispersion stabilizer comprising a vinyl alcohol polymer (A) having a viscosity-average degree of polymerization of more than 400 and less than 1,000, a degree of saponification of more than 67 mol % and less than 78 mol %, 0.02 mol % to 1.0 mol % of a group having an ethylenic double bond in its side chain, and an absorbance (x) at 280 nm of more than 0.17 and less than 0.65 in an ultraviolet absorption spectrum of a 0.1 mass % aqueous solution.

The present invention relates to novel nanoparticles using an anionic polymer, a preparation method thereof, a composition, and the like, and the present invention is used for a method of necrosing cancer cells by blocking major blood vessels that supply nutrients to cancer cells to induce an embolic effect, and thus may be used for the treatment of patients with cancer.

The present invention relates to novel nanoparticles using an anionic polymer, a preparation method thereof, a composition, and the like, and the present invention is used for a method of necrosing cancer cells by blocking major blood vessels that supply nutrients to cancer cells to induce an embolic effect, and thus may be used for the treatment of patients with cancer.

The invention describes a method for manufacture of plasticized homopolymeric polyvinyl alcohol, the method including the steps of introducing a polyvinyl alcohol polymer or a blend thereof having a degree of hydrolysis in the range of 93 wt % to 98 wt % into a mixing reactor; adding a processing agent, a plasticizer and a reactive stabilizer to form a reaction mixture; wherein the plasticizer is selected from the group consisting of sugar alcohols, diols, triols, polyols and mixtures thereof; wherein the reactive stabilizer is selected from the group consisting of sodium stearate, potassium oleate, sodium benzoate, calcium stearate, stearic acid, dimethyl propionic acid, and mixtures thereof;-reacting the reaction mixture in a reaction zone to form plasticized polymer; and-allowing the plasticized polymer to pass from the reaction zone.

An object of the present invention is to provide a diverting agent that can exhibit sufficient filling properties against a fracture in a well in an excavation method using a hydraulic fracturing method, and that is excellent in solubility after a predetermined period of time has passed. The diverting agent of the present invention contains a polyvinyl alcohol-based resin having an average polymerization degree of 1000 or more.

An object of the present invention is to provide a diverting agent that exhibits sufficient filling properties against a fracture in a well because of swelling without completely dissolution for a certain period of time (about 30 minutes to 5 hours), and that quickly dissolves and be removed even at a low temperature of 40° C. to 60° C. after a certain period of time has passed. The present invention relates to a diverting agent containing a modified polyvinyl alcohol-based resin.

A polyvinyl alcohol has a number-average molecular weight (Mn) from 4,400 to 440,000, a molecular weight distribution (Mw/Mn) from 1.05 to 1.70, a degree of saponification from 80 to 99.99 mol %, and a carbon-carbon double bond content (X) of 0.1 mol % or less based on total monomer units, and satisfying a formula (1) below. A polyvinyl alcohol, having a narrow molecular weight distribution and a high number-average molecular weight with good hue, and a method for producing the same are thus provided.
X.Math.Mn≤1000  (1)

A polyvinyl alcohol has a number-average molecular weight (Mn) from 4,400 to 440,000, a molecular weight distribution (Mw/Mn) from 1.05 to 1.70, a degree of saponification from 80 to 99.99 mol %, and a carbon-carbon double bond content (X) of 0.1 mol % or less based on total monomer units, and satisfying a formula (1) below. A polyvinyl alcohol, having a narrow molecular weight distribution and a high number-average molecular weight with good hue, and a method for producing the same are thus provided.
X.Math.Mn≤1000  (1)

A hydrophilic polymer comprising pendent groups of the formula I: Wherein: W is independently selected from —OH, —COOH, —SO.sub.3H, —OPO.sub.3H, —O—(C.sub.1-4alkyl), —O—(C.sub.1-4alkyl)OH, —O—(C.sub.1-4alkyl)R.sup.2, —O—(C.sub.2H.sub.5O).sub.qR.sup.1—(C═O)—O—C.sub.1-4alkyl and —O—(C═O)C.sub.1-4alkyl; or a group —BZ; wherein —OH, COOH, O—PO.sub.3H and SO.sub.3H maybe in the form of a pharmaceutically acceptable salt; wherein: B is a bond, or a straight branched alkanediyl, oxyalkylene, alkylene oxaalkylene, or alkylene (oligooxalkylene) group, optionally containing one or more fluorine substituents; and Z is an ammonium, phosphonium, or sulphonium phosphate or phosphonate ester zwitterionic group; X is either a bond or a linking group having 1 to 8 carbons and optionally 1 to 4 heteroatoms selected from O, N and S; G is a coupling group through which the group of the formula I is coupled to the polymer and is selected from ether, ester, amide, carbonate, carbamate, 1,3 dioxolone, and 1,3 dioxane; R.sup.1 is H or C.sub.1-4 alkyl; R.sup.2 is —COOH, —SO.sub.3H, or —OPO.sub.3H.sub.2 q is an integer from to 4; n is an integer from 1 to 4; p is an integer from 1 to 3; and n+p is from 2 to 5; and wherein —COOH, —OPO.sub.3H.sub.2 and —SO.sub.3H as well as phenolic —OH maybe in the form of a pharmaceutically acceptable salt.

A hydrophilic polymer comprising pendent groups of the formula I: Wherein: W is independently selected from —OH, —COOH, —SO.sub.3H, —OPO.sub.3H, —O—(C.sub.1-4alkyl), —O—(C.sub.1-4alkyl)OH, —O—(C.sub.1-4alkyl)R.sup.2, —O—(C.sub.2H.sub.5O).sub.qR.sup.1—(C═O)—O—C.sub.1-4alkyl and —O—(C═O)C.sub.1-4alkyl; or a group —BZ; wherein —OH, COOH, O—PO.sub.3H and SO.sub.3H maybe in the form of a pharmaceutically acceptable salt; wherein: B is a bond, or a straight branched alkanediyl, oxyalkylene, alkylene oxaalkylene, or alkylene (oligooxalkylene) group, optionally containing one or more fluorine substituents; and Z is an ammonium, phosphonium, or sulphonium phosphate or phosphonate ester zwitterionic group; X is either a bond or a linking group having 1 to 8 carbons and optionally 1 to 4 heteroatoms selected from O, N and S; G is a coupling group through which the group of the formula I is coupled to the polymer and is selected from ether, ester, amide, carbonate, carbamate, 1,3 dioxolone, and 1,3 dioxane; R.sup.1 is H or C.sub.1-4 alkyl; R.sup.2 is —COOH, —SO.sub.3H, or —OPO.sub.3H.sub.2 q is an integer from to 4; n is an integer from 1 to 4; p is an integer from 1 to 3; and n+p is from 2 to 5; and wherein —COOH, —OPO.sub.3H.sub.2 and —SO.sub.3H as well as phenolic —OH maybe in the form of a pharmaceutically acceptable salt.