摘要:
Aromatic polyamide compositions with improved electrostatic properties, formed structures produced therefrom, and use and production thereof.Described are compositions comprising an aromatic polyamide which is soluble in organic solvents and from 0.01 to 30% by weight, based on the weight of the composition, of an organic or organometallic charge control agent.The compositions can be used for producing formed structures, in particular fibers; these fibers are preferably used for producing webs which can be used for producing dust filters.
摘要:
A process for producing fibers or films by the steps of:a) preparing an aromatic polyamide by polycondensation of dicarbonyl dihalides or mixtures thereof with at least two diamines in N-alkyllactams as a solvent, the polycondensation being of at least 90 mol %, based on the total amount of dicarbonyl dihalides in the reaction mixture, of compounds of the formula I or mixtures of such compoundsHal--OC--Ar.sup.1 --CO--Hal (I)with at least 90 mol%, based on the total amount of diamines in the reaction mixture, of compounds of the formula II and optionally III or mixtures of such compoundsH.sub.2 N--Ar.sup.2 --NH.sub.2 (II), H.sub.2 N--Ar.sup.3 --NH.sub.2 (III)where Ar.sup.1, Ar.sup.2 and Ar.sup.3 are independently of each other a bivalent aromatic radical, the proportion of structural repeat units in the aromatic polyamide derived from the compounds of the formula II, based on the proportion of the structural repeat units derived from the compounds of the formulae II and III, being at least 50 mol %, and said aromatic polyamide is soluble in organic solvents,b) forcing the solution of the aromatic polyamide obtained in step a) through dies of the desired cross-sectional shape at temperatures from 40.degree. to 120.degree. C. to form fibers or films,c) removing the organic solvent in a conventional manner to produce solvent-leaner or -free fibers or films sufficiently mechanically stable and nontacky for further processing.The process of the invention omits the customary neutralization after the aromatic polyamide has been prepared.
摘要:
Aromatic copolyamides, production thereof, formed structures and production thereofDescribed are aromatic copolyamides comprising the structural repeat units of the formulae I, II and III ##STR1## where Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.4 are independently of one another bivalent aromatic radicals whose valence bonds are disposed para or comparably coaxial or parallel to each other,
摘要:
Fibers having a tenacity of more than 80 cn/tex and a filament linear density of more than 8 dtex which contain as the fiber-forming material an aromatic polyamide which is soluble in organic solvents and spinnable from isotropic spinning solutions. The fibers can be used for example as reinforcing materials, as heat-resistant insulator materials, for producing filter fabrics or as insulating materials.
摘要:
Two-component loop yarns are composed of core and effect filaments, at least part of the core component consisting of aromatic polyamides, wherein the aromatic polyamides contain the structural repeat units of the formulae I and II--OC--Ar.sup.1 --CO--NH--Ar.sup.2 --NH-- (I)--OC--Ar.sup.1 --CO--NH--Ar.sup.3 --NH-- (II),where Ar.sup.1, Ar.sup.2 and Ar.sup.3 are each independently of the others a bivalent mono- or polycyclic aromatic radical whose free valences are disposed para or meta or comparably parallel, coaxial or angled to each other, and Ar.sup.2 and Ar.sup.3 each have different individual meanings within the scope of the given definitions, and the respective monomer components underlying the polymer are selected so as to produce an aromatic polyamide which forms preferably isotropic solutions in organic solvents.
摘要:
Novel aramid fibers with a spin finish having useful properties for the production of sheet materials are described in the present application. The aramid fibers contain at least three elements including an anionic antistat based on phosphoric, phosphonic, or phosphoric and phosphonic esters; a compound of the formula .sup.1 --COO--(CH.sub.2 --CH.sub.2 --O--).sub.x --R.sup.2 ; and a compound of the formula R.sup.2 --O--(R.sup.4 --O).sub.y --R.sup.5, wherein R.sup.1 is alkyl or alkenyl, x is an integer from 2 to 20 R.sup.2 is hydrogen or alkyl, R.sup.3 is alkyl or alkenyl, y is an integer from to 8, R.sup.4 is ethylene, propylene, or butylene, and R.sup.5 is alkyl.
摘要:
Porous carbon fibers, whose active centers are formed by pores that are filled at least in part by carbon and/or metal and/or metal carbide, obtainable by carbonization of organic or inorganic polymers, the use thereof for the adsorption or separation of gaseous substances, in particular of CO2, and also a method for the production thereof. First, a spinning mixture containing polyacrylonitrile-based polymer A and an organic or metallo-organic polymer B is produced. Next, the spinning mixture is spun to form mixed fibers of polymer A and polymer B. The mixed fiber is stabilized by oxidation. This is followed by carbonization or graphitization of the mixed fiber under non-oxidizing conditions in such a way that the polymer B forms a carbon and/or metal and/or metal carbide residue of at least 22 wt %, the residue forming active centers.
摘要:
Aromatic polyamide staple fiber bundles of improved dispersibility in viscous matrices and production of fiber-reinforced compositesDescribed are bundles of aromatic polyamide staple fibers having a staple length of at least 1 mm which have been provided with an effective amount of an agent which enhances the cohesion of the fiber bundle.The staple fiber bundles are held together by the adhesive before mixing into a matrix material and separate into individual fibers on mixing into the matrix material. There is no need for special mixing apparatus.
摘要:
A method monitors and measures the uniformity of tows with mechanical sensing elements in the course of production on a tow line. The tension of the running tow is measured upstream of a transport roll arrangement and is utilized as a measure of the uniformity of the tow. Irregularities in the tow result in tow tension determination outside a predetermined tension range, and when the determined tension measurement is outside that range the irregular tow portions are remove. Also, the frequency of tow tension determination outside a predetermined range may be used as an indication of tow quality and for removing substandard tows.
摘要:
Lightweight heat-conducting plates of compressed expanded graphite material have layer planes which are preferably disposed so as to be parallel to the surface so that heat conduction in a lateral direction is preferred to heat conduction perpendicular to the plate plane. The heat-conducting plates are suitable for the transmission of heat of floor-heating, wall-heating, ceiling-heating and other flatly disposed heating systems and air-conditioning ceilings, for the transmission of heat and the dissipation of heat in buildings, automobiles, machines, installations and containers. The heat-conducting plates are dimensionally stable without the addition of binder and aggregates and can be produced in a continuous process. A composite component having at least one heat-conducting plate and a method for production of heat-conducting plates are also provided.