Abstract: A shell-and-tube heat exchanger, for removing volatile substances from a polymer solution by degasification, includes a bundle of tubes arranged vertically and parallel to each other in a shell chamber through which a fluid heat-transfer medium flows. The upper end of each tube is fixed in an upper tube sheet and the lower end of each tube is fixed in a lower tube sheet, and the polymer solution flows through the tubes in the direction of gravity. One feature is that a multilayer woven wire fabric is attached to the top of the upper tube sheet. The finest meshed layer of the fabric has a mesh width of 50 ?m to 1000 ?m. The invention also relates to a method for removing volatile substances from a polymer solution by degasification in a shell-and-tube heat exchanger and use of the shell-and-tube heat exchanger.

Abstract: The present invention relates to thermoplastic molding compositions having a mixture of (a) from 10 to 50% by weight of a methyl methacrylate polymer as component (A), from 20 to 60% by weight of a copolymer as component (B), and from 20 to 70% by weight of a graft copolymer as component (C). Component (C) is obtainable from components (c1) a core, (c2) a first graft shell, and (c3) a second graft shell. The second graft shell (c3) is obtainable via polymerization of a C1-C8-alkyl ester of methacrylic acid as component (c31) and a further vinylaromatic monomer as component (c32). Graft copolymer (C) is produced via emulsion polymerization and is isolated from the reaction mixture by precipitation resulting from shear. Also disclosed are processes for producing the molding compositions, the use of the molding compositions, and moldings obtainable from the molding compositions.

Abstract: A shell-and-tube heat exchanger, for removing volatile substances from a polymer solution by degasification, includes a bundle of tubes arranged vertically and parallel to each other in a shell chamber through which a fluid heat-transfer medium flows. The upper end of each tube is fixed in an upper tube sheet and the lower end of each tube is fixed in a lower tube sheet, and the polymer solution flows through the tubes in the direction of gravity. One feature is that a multilayer woven wire fabric is attached to the top of the upper tube sheet. The finest meshed layer of the fabric has a mesh width of 50 ?m to 1000 ?m. The invention also relates to a method for removing volatile substances from a polymer solution by degasification in a shell-and-tube heat exchanger and use of the shell-and-tube heat exchanger.

Abstract: The present invention relates to thermoplastic molding compositions comprising a mixture composed of (A) at least one methyl methacrylate polymer, (B) at least one copolymer, obtainable via polymerization of a mixture, composed of (B1) at least one vinylaromatic monomer, and (B2) at least one vinyl cyanide, as monomers, (C) at least one graft polymer, obtainable from a core, and a first graft shell, and a second graft shell, (D) at least one polybutyl acrylate whose molar mass is from 1700 to 4000 g/mol (determined as Mw by means of gel permeation chromatography), and (E) if appropriate conventional additives, as component (E), to a process for preparation of these thermoplastic molding compositions, to the use of this thermoplastic molding composition for production of moldings, and also to the use of styrene-methyl methacrylate copolymers whose molar mass is from 1700 to 4000 g/mol (determined as Mw by means of gel permeation chromatography) for improvement of flowability and for reduction of the dependency

Abstract: The present invention relates to thermoplastic molding compositions comprising a mixture of (a) from 10 to 50% by weight, based on the entirety of components (A), (B), and (C), of a methyl methacrylate polymer as component (A), and (b) from 20 to 60% by weight, based on the entirety of components (A), (B), and (C), of a copolymer as component (B), obtainable via polymerization of a vinylaromatic monomer and of a vinyl cyanide, and (c) from 20 to 70% by weight, based on the entirety of components (A), (B), and (C), of a graft copolymer as component (C), obtainable from (c1) from 50 to 70% by weight, based on (C), of a core as component (C1), obtainable via polymerization of a 1,3-diene and of a vinylaromatic monomer and an agglomeration polymer, and (c2) from 15 to 25% by weight, based on (C), of a first graft shell as component (C2), obtainable via polymerization of a vinylaromatic monomer, of a C1-C8-alkyl ester of methacrylic acid, and/or of a C1-C8-alkyl ester of acrylic acid, and a crosslinking monomer,

Abstract: The present invention relates to thermoplastic molding compositions comprising a mixture of (A) from 30 to 69% by weight, based on the sum of components (A), (B) and (C), of a methyl methacrylate polymer, (B) from 30 to 69% by weight, based on the sum of components (A), (B) and (C), of a copolymer obtainable by polymerizing a styrenic monomer and a vinyl cyanide, and (C) from 1 to 40% by weight, based on the sum of components (A), (B) and (C), of a graft copolymer obtainable from (C1) from 60 to 90% by weight, based on (C), of a core obtainable by polymerizing a 1,3-diene and a styrenic monomer, (C2) from 5 to 20% by weight, based on (C), of a first graft shell, and (C3) from 5 to 20% by weight, based on (C), of a second graft shell composed of an alkyl (meth)acrylate polymer, with the proviso that the ratio of (C2) to (C3) is in the range from 2:1 to 1:2.

Abstract: The present invention relates to thermoplastic molding compositions comprising a mixture composed of (A) at least one methyl methacrylate polymer, (B) at least one copolymer, obtainable via polymerization of a mixture, composed of (B1) at least one vinylaromatic monomer, and (B2) at least one vinyl cyanide, as monomers, (C) at least one graft polymer, obtainable from a core, and a first graft shell, and a second graft shell, (D) at least one polybutyl acrylate whose molar mass is from 1700 to 4000 g/mol (determined as Mw by means of gel permeation chromatography), and (E) if appropriate conventional additives, as component (E), to a process for preparation of these thermoplastic molding compositions, to the use of this thermoplastic molding composition for production of moldings, and also to the use of styrene-methyl methacrylate copolymers whose molar mass is from 1700 to 4000 g/mol (determined as Mw by means of gel permeation chromatography) for improvement of flowability and for reduction of the dependency

Abstract: The present invention relates to thermoplastic molding compositions comprising a mixture of (A) from 30 to 69% by weight, based on the sum of components (A), (B) and (C), of a methyl methacrylate polymer, (B) from 30 to 69% by weight, based on the sum of components (A), (B) and (C), of a copolymer obtainable by polymerizing a styrenic monomer and a vinyl cyanide, and (C) from 1 to 40% by weight, based on the sum of components (A), (B) and (C), of a graft copolymer obtainable from (C1) from 60 to 90% by weight, based on (C), of a core obtainable by polymerizing a 1,3-diene and a styrenic monomer, (C2) from 5 to 20% by weight, based on (C), of a first graft shell, and (C3) from 5 to 20% by weight, based on (C), of a second graft shell composed of an alkyl (meth)acrylate polymer, with the proviso that the ratio of (C2) to (C3) is in the range from 2:1 to 1:2, the essence of the invention being that the first graft shell (C2) is obtainable by polymerizing a monomer mixture consisting of (C21) from 30 to 39% by we

Abstract: Polymer powders which are redispersible in water and are obtainable by atomizing aqueous polymer dispersions to which from 3 to 50% by weight, based on the polymer, of a water-soluble alkali metal salt or alkaline earth metal salt of a phenolsulfonic acid/formaldehyde condensate has been added are used as additives in hydraulic binders.

Abstract: A novel, optically transparent, isotropic molding for optical purposes which is free of orientation birefringence consists of a mixture of polyphenylene ethers, vinylaromatic polymers and additives. The novel molding contains traces of novel diphenoquinone and/or diphenohydroquinone derivatives as additives and may also contain novel ammonium salts of sulfuric acid half esters of diphenohydroquinones as further additives. The novel molding has a yellowness index (YI) of from 40 to 90. It can be produced in a simple manner by injection molding processes. The novel molding in the form of a circular disk having a central hole is very useful as a dimensionally stable substrate of audio compact disks (CD), audiovisual compact disks (CDV), laser-optical computer disks and magneto-optical computer disks, and data media of this type which contain these novel dimensionally stable substrates have particularly advantageous performance characteristics.