Abstract: The present invention relates to a process for production of (meth)acrylic acid, whereby first a crude (meth)acrylic acid is produced and this crude (meth)acrylic acid is then continuously purified, whereby the continuous purification of the crude (meth)acrylic acid comprises the following process steps: a) in a composition comprising (meth)acrylic acid and impurities, precipitating the impurities in crystalline form from the composition; and b) separating the crystalline impurities precipitated from the composition. The invention also relates to the (meth)acrylic acid obtainable by this process, a device for production of (meth)acrylic acid, the use of the device or of a purification device for production of (meth)acrylic acid, (meth)acrylic acid, water-absorbing polymers, the use of water-absorbing polymers as well as fibers, sheets, foams and composites.

Abstract: A process for the preparation of (meth)acrylic acid is disclosed that includes: (a) contacting a product gas containing (meth)acrylic acid obtained from a gas phase oxidation with an aqueous phase in a quenching unit to obtain an aqueous quenched phase, (b) distilling the quenched phase in a distillation unit to obtain a bottom product and a top product, and (c) crystallizing at least the bottom product in a crystallization unit to obtain pure (meth)acrylic acid. An organic separating agent can be added after the quenching unit, such as at the latest in the crystallization unit. Also disclosed are a device for the preparation of (meth)acrylic acid, a process for the preparation of a polymer from the (meth)acrylic acid, a device for the preparation of the polymer, a polymer obtainable by this process, and the use of the (meth)acrylic acid or the polymer in a chemical product, such as fibers or shaped articles.

Abstract: The invention concerns a process for purification of an acidic monomer having a double bond, as well as a device for synthesis of an acidic monomer having a double bond, a process for producing an acidic monomer having a double bond, an acid monomer having a double bond and obtainable by this process, fibers, formed bodies, films, foams, superabsorbent polymers and other special polymers based on or containing this acidic monomer, the use of this acidic monomer in or for producing fibers, formed bodies, films, foams, superabsorbent polymers or other special polymers.

Abstract: A process for the preparation of (meth)acrylic acid is disclosed that includes: (a) contacting a product gas containing (meth)acrylic acid obtained from a gas phase oxidation with an aqueous phase in a quenching unit to obtain an aqueous quenched phase, (b) contacting the quenched phase with an organic separating agent in an extraction unit to give a first phase and at least one other phase, (c) crystallizing at least one of the first phase and the at least one other phase, such as by a suspension crystallization, in a crystallization unit to obtain a pure (meth)acrylic acid. Also disclosed are a device for the preparation of (meth)acrylic acid, a process for the preparation of a polymer from the (meth)acrylic acid, a device for the preparation of the polymer, a polymer obtainable by this process, and the use of the (meth)acrylic acid or the polymer in a chemical product, such as fibers or shaped articles.

Abstract: The present invention relates to a process for production of (meth)acrylic acid, whereby first a crude (meth)acrylic acid is produced and this crude (meth)acrylic acid is then continuously purified, whereby the continuous purification of the crude (meth)acrylic acid comprises the following process steps: a) in a composition comprising (meth)acrylic acid and impurities, precipitating the impurities in crystalline form from the composition; and b) separating the crystalline impurities precipitated from the composition. The invention also relates to the (meth)acrylic acid obtainable by this process, a device for production of (meth)acrylic acid, the use of the device or of a purification device for production of (meth)acrylic acid, (meth)acrylic acid, water-absorbing polymers, the use of water-absorbing polymers as well as fibers, sheets, foams and composites.

Abstract: The present invention relates to a process for cleaving a (meth)acrylic acid oligomer of structure I wherein R1 is a hydrogen atom or a C1 to C10 alkyl groups, R2 is a hydrogen atom or a methyl group, and n is a whole number within the range between 1 and 200, optionally in the presence of a cleaving agent of the structure R3—OH or of the structure (R4)2—N—H, whereby R3 is a hydrogen atom, a C1 to C12 alkyl group, or a —CxH2x—OH— group, whereby x is a whole number within a range from 1 to 12, and R4 is a hydrogen atom or a C1 to C12 alkyl group, with the proviso that not both R4 groups are hydrogen atoms, whereby the (meth)acrylic acid oligomers are heated with the cleaving agent to a temperature of at least 50° C. at a pressure of at least 1 bar.

Abstract: The invention concerns a process for purification of an acidic monomer having a double bond, as well as a device for synthesis of an acidic monomer having a double bond, a process for producing an acidic monomer having a double bond, an acid monomer having a double bond and obtainable by this process, fibres, formed bodies, films, foams, superabsorbent polymers and other special polymers based on or containing this acidic monomer, the use of this acidic monomer in or for producing fibres, formed bodies, films, foams, superabsorbent polymers or other special polymers.