摘要:
This invention describes high-strength fibers with high initial moduli from homopolymers or copolymers comprising at least 70% by weight repeating acrylonitrile and/or methacrylonitrile units, and a process especially adapted for their preparation, and their use, especially as reinforcing materials or for producing filters or friction coatings. The fibers according to the invention have a strength of more than 100 cN/tex and an initial modulus of more than 15 N/tex (based on 100% elongation).
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 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 and apparatus for guiding a continuous moving tow in synthetic fiber manufacture. The profile (the thickness distribution and width) and the position of the tow are continuously sensed in a non-contact manner and an appropriate electrical signal is generated. This electrical signal is used to control the profile and the position of the tow in such a way that its profile and position stay within predetermined target value ranges. The tow geometry is preferably sensed using a CCD camera, while the tow geometry is controlled using tow-engaging deflecting means. In this way it is possible to optimize tow profile and position, for example for entry into a stuffer box (FIG. 1).
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:
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:
Described are aramid fibers with a spin finish comprising A) a compound of the formula I and/or II R.sup.1 --COO--(R.sup.2 --O).sub.x --R.sup.3 (I) R.sup.3 --(O--R.sup.2).sub.x --OOC--R.sup.4 --COO--(R.sup.2 --O).sub.x --R.sup.3 (II) and B) a compound of the formula III ##STR1## where R.sup.1 is alkyl or alkenyl having eight to eighteen carbon atoms, x is an integer from four to twenty, R.sup.2 is butylene, propylene or ethylene, R.sup.3 is hydrogen or C.sub.1 -C.sub.22 -alkyl or C.sub.2 -C.sub.22 -alkenyl, R.sup.4 is alkylene or alkenylene having eight to eighteen carbon atoms, R.sup.5 is alkyl or alkenyl having eight to eighteen carbon atoms, R.sup.6 and R.sup.7 are each alkyl having one to twelve carbon atoms, and R.sup.8 is alkylene having one to four carbon atoms. The aramid fibers are usable in particular in the production of textile sheet materials by intermingling, twisting, braiding or folding.
摘要:
A process for producing mass-colored fiber or film, comprises the steps of:a) preparing a premix by grinding a composition comprising a polar aprotic organic solvent, 5 to 30% by weight of an aromatic polyamide and 0.5 to 5% by weight of a color-conferring solid component so that the color-conferring solid component has particles with an average diameter of less than 200 nm,b) preparing a forming solution by mixing the premix produced in step a) with a solution comprising a polar aprotic organic solvent and an aromatic polyamide which corresponds to the aromatic polyamide used in step a), just upstream of a forming die,c) extruding the forming solution through the forming die which comprises orifices in a predetermined number and shape to produce primary fiber or film,d) removing the polar aprotic organic solvent in a conventional manner to leave solvent-leaner or-free fiber or film of sufficient mechanical stability and nontackiness for further processing, ande) optionally orienting the resulting fiber or film in a convention manner.