49 results about "Poly(methacrylic acid)" patented technology

The purpose of the present invention is to provide a method for producing a catalyst for use in the production of methacrylic acid through the vapor-phase catalytic oxidation of methacrolein, isobutylaldehyde or isobutyric acid with high yield and high selectivity. A catalyst produced by adding an alkali metal element, particularly cesium among alkali metal elements, to a partially neutralized salt of a heteropoly acid by a specific method, wherein the partially neutralized salt contains Mo, V, P, an alkali metal element and NH4 as essential active components. The catalyst is characterized by having extremely high catalytic performance.

The present invention relates to a process for preparing alkyl methacrylates, especially MMA, and methacrylic acid, based on methacrolein, which has been oxidatively esterified in a second process stage. Methacrolein is obtainable in principle from C2 and C4 units. The present process has the advantage that the alkyl methacrylate and methacrylic acid can be obtained in a simple manner, in high yields and high purities, either as a mixture or as isolated product streams. In particular, the process of the invention has the great advantage that especially the ratio of the desired methacrylic acid and alkyl methacrylate, especially MMA, products can be adjusted freely within a wide range and varied by chemical engineering measures and operating parameters.

The invention discloses an alkaline-soluble acrylate polymer composition, which is prepared from the raw material formula by emulsion polymerization. The alkaline-soluble acrylate polymer composition comprises the following components in percentage by weight: 8wt%-15wt% of an unsaturated carboxylic acid monomer as a monomer phase, 19wt%-28wt% of at least one C1-C10 alkyl ester of acrylic acid or methacrylic acid, 60wt%-70wt% of deionized water as a water phase, 1wt%-3wt% of a prepolymerized linear polymer, 0wt%-3wt% of protective colloid, 0.05wt%-1.0wt% of an emulsifier, 0.05wt%-0.2wt% of a cross-linking agent and 0.05wt%-0.5wt% of an initiator, wherein the number-average molecular weight is 10,000-100,000; and the cross-linking agent is added to a reaction system after 28%-58% of monomer phase is consumed. The invention aims at providing the alkaline-soluble acrylate polymer composition which is small in amount in the formula, good in suspending power in a low pH condition, high in thickening capacity, and good in transparency; and meanwhile, a preparation method of the alkaline-soluble acrylate polymer composition is also provided.

A process for producing a (meth)acrylic acid compound, which comprises distilling acrylic acid, methacrylic acid (these will hereinafter generally be referred to as “(meth)acrylic acid”) or an ester thereof (these will hereinafter generally be referred to as “a (meth)acrylic acid compound”) in a distillation column to obtain a purified (meth)acrylic acid compound, characterized in that in the course of operation of the distillation column including suspension and resumption of the operation, the distillation column is washed with water and, thereafter, inside washing with an organic solvent and / or azeotropic distillation in the presence of the organic solvent is conducted. In some cases, washing with alkaline water may be added prior to the washing with water. Washing of the distillation column for separating and purifying a crude (meth)acrylic acid compound, can be carried out easily. In particular, in a process for producing a (meth)acrylic acid compound, a substance used in a step before or after the distillation column can be utilized to recover a valuable substance, and the distillation column can be efficiently cleaned.