摘要:
In the preparation of a rubber-modified molding material, in a first stage, a first mixture (A) contains at least one alkyl acrylate or methacrylate (a) of the formula (I) ##STR1## where R.sup.1 is hydrogen or methyl and R.sup.2 is alkyl of 1 to 32 carbon atoms, a compound (b) of the formula (II) ##STR2## where R.sup.3 is hydrogen or methyl, R.sup.4 is hydrogen or alkyl of 1 to 8 carbon atoms, R.sup.5 is hydrogen or methyl and R.sup.6 is hydrogen or alkyl of 1 to 10 carbon atoms, preferably hydrogen, and, if required, a first monomer (c) or a plurality thereof is polymerized with free radicals to give a rubber (B),in a second stage, the resulting rubber (B) is mixed with a second monomer (d) or with a plurality thereof, preferably dissolved or swollen therein, to form a second mixture (C), andin a third stage, the second mixture (C) formed by mixing is polymerized with free radicals to give the rubber-modified molding material (D).
摘要:
The invention relates to expandable styrene polymers for elastic polystyrene foams, comprisinga) from 75 to 98% by weight of polystyrene and/or a styrene copolymer containing at least 50% by weight of copolymerized styrene,b) from 2 to 25% by weight of at least one styrene-soluble elastomer,c) from 1 to 15% by weight, based on the sum of a) and b), of a low-boiling blowing agent, and, if desired,d) conventional additives in effective amounts,where the unfoamed beads have a structure in which the elastomer phase is dispersed in the polystyrene phase in the form of cell particles, and to foams and foam moldings produced therefrom.
摘要:
The present invention deals with low temperature impact resistant, easily flowing, thermoplastic polyurethane elastomer compositions, comprising:A) 5-95 parts by weight of at least one thermoplastic polyurethane elastomer (A) having a Shore A hardness less hah 95; andB) 95-5 parts by weight of at least one thermoplastic polyurethane elastomer (B) having a Shore A hardness greater than 98, whereby the parts by weight of (A) and (B) total 100 parts by weight; andC) 0-60 weight percent based on the weight of (A) and (B) of a reinforcing filler.The products are prepared by melting together polyurethane elastomers (A) and (B) at temperatures of from 140.degree.-250.degree. C., preferably in an extruder, and are most preferred for the preparation of ski boots and injection molded articles for motor vehicles.
摘要:
The present invention relates to transparent essentially non-cellular polyurethane casting compositions that are sterilizable with superheated steam which are prepared by reacting:(A) modified diphenylmethane diisocyanates (A) liquid at 23.degree. C. obtained by reacting(A1) 4,4'-diphenylmethane diisocyanate or(A2) 2,4'-diphenylmethane diisocyanate or(A3) a diphenylmethane diisocyanate mixture with(A4) at least one polyoxypropylene polyol and/or(A5) at least one polyoxypropylene polyoxyethylene polyol containing 1 to 80 weight percent of ethylene oxide units whereby (A4) and (A5) have a functionality of 4 to 8 and a hydroxyl number of 150 to 500 and are obtained while using sucrose and/or preferably sorbitol as initiator molecules(A6) a mixture of (A4) and/or (A5) and at least one polyoxypropylene polyol and/or polyoxyethylene polyol initiated with glycerine and/or trimethylolpropane in a NCO:OH group ratio of 2.5:1 to 15:1 with(B) at least one compound having at least reactive hydrogen atoms which preferably contains no primary, secondary or tertiary amino groups in bonded form in the presence of or absence of(C) catalysts.The present invention also relates to a process for the preparation of polyurethane casting compositions and their use for medical-technical articles.
摘要:
Low-shrinkage nylon moldings are produced by activated alkaline lactam polymerization, preferably using the reactive injection molding technique, by a process wherein the polymerization is carried out in the presence of from 5 to 80% by weight of a polymer P which1. is completely soluble in the lactam,2. separates out in the course of polymerization at a conversion of from 1 to 50%,3. is composed of one or more blocks which are compatible with polylactam and one or more blocks which are incompatible therewith, and preferably4. possesses functional groups which are incorporated into the growing polylactam chain.
摘要:
Crystallite suspensions containing from 3 to 70 weight percent of a crystalline, ethylenically unsaturated polyester prepared through condensation polymerization, and having a molecular weight factor per double bond of 154.4 to 408, as the dispersed phase, and from 30 to 97 weight percent of a polyhydroxyl compound having a functionality of from 2 to about 8, a hydroxyl number of from 20 to 800, and a melting point of less than 30.degree. C. as the coherent phase are suitable for preparing non-cellular and cellular polyurethane- or polyurethane group-containing polyisocyanurate foams.
摘要:
Use of thermoplastic molding compositions comprising, as essential components, A) a polyester, B) from 20 to 200 mmol/kg of polyester A) of at least one compound of the general formula (I) where respectively independently at any position -A1- is —NR—, —O—, —S—, —CH=A4- where R is H or C1-6-alkyl, A4 is N or CH A2 is COOX or OX, where X is Li, Na, K, Rb, Cs, Mg/2, Ca/2, Sr/2, Ba/2, Al/3 A3 is C1-6-alkyl, C6-12-aryl, O7-13-alkaryl, C7-13-aralkyl, O—C1-6-alkyl, O—C6-12-aryl, O—C7-13-alkaryl, O—C7-13-aralkyl, COOX′, OX′, SX′, SO3X′, where X′ is H or X, S—C1-6-alkyl, S—C6-12-aryl, NR2, halogen, NO2, n is an integer from 1 to 4, and m is an integer from 0 to 4−n, where m=1, if A3=NO2, with the proviso that the number of mmol is based on the group(s) COOX and OX and SX′ where X′═X, to the extent that these are present in the compound of the general formula (I), and also moreover C) from 0 to 230% by weight of further added substances, based on the weight of component A), for producing laser-transparent moldings of any type.
摘要:
The invention relates to a process for the preparation of thermoplastic molding materials comprising A) from 39 to 99% by weight of at least one thermoplastic polymer, B) from 1 to 60% by weight of a flameproofing component comprising B1) an expandable graphite, and C) from 0 to 60% by weight of further additives, the percentages by weight being based in each case on the total weight of the components A) to C) and together giving 100% by weight, by mixing melts of the components A), B) and, if present, C) in a screw extruder, the screw extruder comprising at least one metering zone, one plasticating zone, one homogenization zone and one discharge zone in this sequence along the conveying direction, wherein the metering of the expandable graphite B1) into the screw extruder is effected at a point behind which—viewed in the conveying direction—the extruder screw comprises substantially no shearing elements, and thermoplastic molding materials which can be prepared by these processes, the use of said thermoplastic molding materials for the production of fibers, films, moldings and foams, and these fibers, films, moldings and foams themselves.
摘要:
The present invention relates to a process for producing polymer fibers, especially nano- and mesofibers, by electrospinning a colloidal dispersion of at least one essentially water-insoluble polymer in an aqueous medium, and to fibers obtainable by this process, to textile fabrics comprising the inventive fibers, and to the use of the inventive fibers and of the inventive textile fabrics.
摘要:
Molding materials (F) which are suitable for the production of shaped articles having reduced surface gloss and are based on polymers or polymer blends (P), preferably ASA polymers and/or styrene/acrylonitrile copolymers, contain a sufficient amount of a dull graft copolymer (A) admixed as dulling agent, which was prepared by one-stage or multistage graft copolymerization of monomers forming the hard shell onto an elastomeric acrylate polymer, the graft copolymerization being carried out to a conversion of more than 15% by thermal or free radical mass or solution polymerization.