摘要:
Poly(alkylene terephthalate) molding materials which contain, as the stabilizer, a diepoxide of molecular weight from 200 to 2,000, and a catalyst which is an alkali metal salt of a chelating agent possessing one or more --N(CH.sub.2 --COO.sup.-).sub.2 groups in the molecule. Preferred catalysts are trisodium nitrilotriacetate and tetrasodium ethylenediaminetetraacetate. The molding materials may be used for the manufacture of moldings, films, monofilaments and fibers.
摘要:
A process for the preparation of high molecular weight linear saturated polyesters derived from dicarboxylic acids or their ester-forming derivatives and aliphatic and/or cycloaliphatic diols, comprising the condensation of polyester precondensates having a relative viscosity of from 1.05 to 1.15 at from 220.degree. to 280.degree. C. under reduced pressure, wherein(a) the condensation is first started with from 70 to 95 percent by weight of the polyester precondensate and(b) after from 10 to 50% of the total condensation time the remaining 5 to 30 percent by weight of the polyester precondensate are added to the polyester melt undergoing condensation in accordance with (a), and the condensation is taken to completion.
摘要:
A process for the preparation of an amide-containing polyether comprises polycondensing a dihalobenzene compound, preferably bis-(4-chlorophenyl) sulfone or 4,4'-bis-(4"-chlorobenzoyl)-diphenyl ether, with an amide-containing bis-phenol of the formula HO-Ar.sup.1 -NHCO-Ar.sup.2 -CONH-Ar.sup.1 -OH where Ar.sup.1 is an aromatic radical of 6 to 12 carbon atoms and Ar.sup.2 is an aromatic radical of 6 to 12 carbon atoms or has the formula II ##STR1## where A.sup.1 is --SO.sub.2 --, --CO--, --C(CH.sub.3).sub.2 -- or 0 and n is 0 or 1, preferably 1,4-bis(4-hydroxybenzamido)-benzene, in the presence of an anhydrous alkali metal carbonate, and optionally in the presence of a bisphenol of the formula III ##STR2## where Ar.sup.1 and A.sup.1 have the above meanings and n and m are 0 or 1. The polyethers may be used to produce moldings, fibers, films, adhesives and coating materials.
摘要:
Thermoplastic molding compositions of polyoxymethylenes and glass fibers and containing from 0.1 to 5.0 per cent, by weight of the total weight of the mixture, of alkoxymethyl ureas having the formula ##EQU1## where R.sup.1 and R.sup.2 are the same or different and denote straight-chain or branched-chain alkyl of from 1 to 10 carbon atoms and R.sup.3 and R.sup.4 denote hydrogen or alkyl, or R.sup.3 and R.sup.4 are joined together to form a heterocyclic ring with the adjacent ureido group.
摘要:
Thermoplastic molding compositions based on polyoxymethylene and containing, to improve the impact resistance, a block copolymer of a diene polymer block B and at least one poly(alkylmethacrylate) block A.
摘要:
Impact-resistant thermoplastic molding compositions containing from 70 to 98 percent by weight of a polyoxymethylene and from 30 to 2 percent by weight of a block copolymer of the general formula A -- B -- A, wherein A is a polyalkylene oxide block and B is a diene polymer block.
摘要:
The present invention relates to a method for aerating and deaerating an oven (1), which has at least two oven muffles (2, 3) disposed one above the other, the feed apertures (5, 6) of which are or can be closed in each case by a door (7, 8), comprising the following procedural steps: cooling air (L) is drawn off from an outside area surrounding the oven (1), and the drawn-off air (L) is blown at least partially into interior spaces (9, 10) of the doors (7, 8) and then blown out into the outside area after flowing through at least a part of the interior spaces (9, 10), wherein the drawn-off air (L) is blown into the upper door (7) in an upper section of that door (7) and flows substantially downward from above through the interior space (9) of the door (7), wherein the drawn-off air (L) is blown into the interior space (10) of the lower door (8) at a bottom end section thereof and flows substantially upward through the interior space (10) of the door (8), and that the air blown into the interior spaces (9, 10) of the two doors (7, 8) is blown out to the outside area after flowing through the interior spaces (9, 10) of the doors (7, 8) in the lower section of the upper door (7) and the upper section of the lower door (8).
摘要:
Copolyamides are prepared by a continuous process in which(a) an aqueous solution of salts of equimolar amounts of diamines and dicarboxylic acids is passed, under superatmospheric pressure and with simultaneous evaporation of water, through a tubular precondensation zone with formation of a vapor phase and a prepolymer at above the melting point of the prepolymer,(b) the vapor phase is separated from the prepolymer melt,(c) the vapor phase is separated in a column into steam and an aqueous diamine solution, and the aqueous solution containing diamines is recycled to the polymerization,(d) the prepolymer melt is mixed with molten caprolactam at polyamide-forming temperatures, and(e) the mixture of prepolymer and caprolactam is passed downward through a vertical polymerization tube at polyamide-forming temperatures and a copolyamide is obtained.
摘要:
The present invention relates to a method for aerating and deaerating an oven (1), which has at least two oven muffles (2, 3) disposed one above the other, the feed apertures (5, 6) of which are or can be closed in each case by a door (7, 8), comprising the following procedural steps: cooling air (L) is drawn off from an outside area surrounding the oven (1), and the drawn-off air (L) is blown at least partially into interior spaces (9, 10) of the doors (7, 8) and then blown out into the outside area after flowing through at least a part of the interior spaces (9, 10), wherein the drawn-off air (L) is blown into the upper door (7) in an upper section of that door (7) and flows substantially downward from above through the interior space (9) of the door (7), wherein the drawn-off air (L) is blown into the interior space (10) of the lower door (8) at a bottom end section thereof and flows substantially upward through the interior space (10) of the door (8), and that the air blown into the interior spaces (9, 10) of the two doors (7, 8) is blown out to the outside area after flowing through the interior spaces (9, 10) of the doors (7, 8) in the lower section of the upper door (7) and the upper section of the lower door (8).
摘要:
Nylons are prepared by a continuous process in which, in a precondensation zone, an aqueous solution of a salt of a dicarboxylic acid of 6 to 18 carbon atoms and a diamine of 6 to 18 carbon atoms is heated to 250.degree.-300.degree. C. under superatmospheric pressure, with simultaneous vaporization of water and formation of a prepolymer, the prepolymer and the vapor are separated, and the former is fed into a polycondensation zone and condensed under superatmospheric pressure of from 1 to 10 bar and at from 250.degree. to 300.degree. C., wherein the aqueous salt solution is condensed under superatomspheric pressure of from 1 to 10 bar in the first third of the tubular precondensation zone provided with baffles, until the degree of conversion is not less than 93%, and the prepolymer and the vapor phase are brought into intimate contact with one another in the remaining two thirds of the precondensation zone.