摘要:
Linear high molecular weight polyamides containing a regulated level of amino and carboxyl end groups are prepared in a continuous process by reacting polyamides in the melt with polyamide-forming diamines or dicarboxylic acids by continuous mixing for a residence time of .ltoreq.10 minutes, granulating the polyamide, and further condensing the polyamide granules thus obtained in solid phase in the presence of inert gases until the viscosity has reached the desired level.
摘要:
Block polymers of vinylaromatics and conjugated dienes which posses acidic terminal groups and are in the form of salts which contain divalent or polyvalent metal cations or cation complexes. A process for the preparation of such salts of block polymers containing acid groups, and the use of these polymers as thermoplastic materials, as thermoplastic elastomers, for modifying thermoplastic materials, as viscosity index improvers in lubricating oils or as components in hot melt adhesives.
摘要:
Photopolymerizable mixtures of (a) one or more block copolymers, (b) one or more photopolymerizable, ethylenically unsaturated, low molecular weight compounds and (c) a photopolymerization initiator, with or without (d) other additives, contain as component (a) block copolymers which are composed solely of elastomeric polymer blocks, and contain two or more elastomeric polymer blocks having a glass transition temperature of from -20.degree. C. to +15.degree. C., linked by one or more elastomeric polymer blocks having a glass transition temperature of below -20.degree. C.
摘要:
Mixtures which can be crosslinked by photopolymerization and are based on binders, photopolymerizable monomers which are compatible with these, photoinitiators and thermal polymerization inhibitors contain, as the binder, polymers of the formula I ##STR1## where Pol is a radical of a block copolymer prepared by sequential anionic polymerization of conjugated dienes and vinyl aromatics,R.sup.1 is a vicinal alkanediyl group,R.sup.2 is a divalent hydrocarbon group of 2 to 20 carbon atoms,X.sup.- is an acid anion,M is a metal cation, a metal cation complex or cation of an amine, anda and n are each an integer from 1 to 10.
摘要:
In an ion beam apparatus a structure for controlling the surface potential of the target comprising an electron source adjacent to the beam for providing electrons to the beam and means between the target and source for inhibiting rectilinear radiations, i.e., electron and other particle and photon radiations between said source and said target. This prevents heating of the target by the electron source and cross-contamination between the source and the target. The apparatus further includes means for maintaining said shield means at a lower temperature than said target. A further structure is provided for the measurement of the ion beam current while controlling said surface potential of the target which includes: walls adjacent to and electrically insulated from the target and surrounding the beam whereby the walls and target provide a Faraday Cage, means for introducing variable quantities of electrons into the beam within the Faraday Cage, means for measuring the target current, means for combining and measuring the target and wall currents to provide said ion beam current measurement and means for varying the quantities of introduced electrons to control the target current and thereby the target surface potential. Likewise, this apparatus further includes means for maintaining said shielding means at a temperature lower than said target.
摘要:
A chuck for a workpiece, rotatable in spaced relation to and about an axis of rotation, and having a clamp jaw radially movable under centrifugal force to engage the workpiece against fixed mating clamp members. The structure can also have optional means enabling the chuck to tilt, with the workpiece, from a home position to a preselected angle under the rotation thereof about a pivot axis perpendicular to and spaced from the axis of rotation with return of the chuck to the home position under gravitational force when rotation thereof is stopped.
摘要:
A process for the preparation of a linear polyamide by reacting the appropriate dicarboxylic acid and diamine in a liquid reaction medium with the addition of a catalytically effective phosphorus compound, removing the reaction medium to give a solid salt, precondensing the latter in the solid phase at a temperature of from 140.degree. C. to 5.degree. C. below the melting point of the salt and continuing condensation at a temperature above that used for the precondensation until the desired degree of condensation is reached.
摘要:
Polymers and copolymers of conjugated dienes and aromatic vinyl compound which have a carboxyl end group and are present as salts, the salts containing metal cations or metal cation complexes which are bivalent or polyvallent and also a process for preparing such salts of polymers which contain carboxyl end groups and their use for modifying thermoplastic materials or as vulcanizable materials.
摘要:
A welding apparatus for bonding small wires to a metal surface wherein an electric current is passed through a portion of a wire in contact with a welding tip, the apparatus having a welding tip support means for supporting the welding tip for rectilinear movement, the support means having movable mass less than 10 grams, the low mass enabling the welding tip to maintain contact with the wire portion during the molten phase of the wire during the welding operation, and a means to urge the tip support means into engagement with the wire.
摘要:
Thermoplastic molding materials containA) 4-94% by weight of a partly aromatic, semicrystalline copolyamide having a triamine content of less than 0.5% by weight and composed of(A.sub.1) 20-90% by weight of units derived from terephthalic acid and hexamethylenediamine,(A.sub.2) 0-50% by weight of units derived from .epsilon.-caprolactam,(A.sub.3) 0-80% by weight of units derived from adipic acid and hexametheylenediamine and(A.sub.4) 0-40% by weight of further polyamide-forming monomers, the amount of components (A.sub.2) or (A.sub.3) or (A.sub.4) or of mixtures thereof being not less than 10% by weight,B) 4-94% by weight of a polyolefin homo- or copolymer or a mixture thereof,C) 2-20% by weight of an adhesion promoter,D) 0-20% by weight of a toughening polymer andE) 0-60 % by weight of additives and processing assistants.