Abstract: A flexible conduit for coolant having a high bursting pressure above 8 bar at 100.degree. C. and high hydrolysis resistance comprising an outer layer of a material selected from the group consisting of homopolyamides, copolyamides and mixtures thereof with an excess of amino terminal groups, a non-swelling inner layer made of a material selected from the group consisting of non-halogenated copolyolefins, non-halogenated homopolyolefins and mixtures thereof and a middle layer compatible with the inner and outer layers made of a homopolyolefin or a copolyolefin with grafted functional groups, the layers being coextruded and corrugated during coextrusion.

Abstract: Cold impact-resistant tubing especially useful as a fuel line for motor vehicles which is stable in length, has a brief thermal overload capacity, and consists of at least three layers of at least two different mutually compatible polyamides. The tubing also preferably has an internal and an external layer of impact resistance-modified polyamide, with or without a plasticizer, and a barrier between the layers of impact resistance modifier-free homopolyamide, copolyamide or blends thereof.

Abstract: An article consisting of a base and one or more attachments thereto. The base is made of one thermoplastic polymer and the attachment is made of a second thermoplastic polymer which is at least partially incompatible with the first polymer. Either the first or second polymer contains 5 to 75% by weight of a third polymer which is an olefinic polymer having functional groups thereon. Either of the first two polymers may contain up to 90% of the usual additives. This enables the production of such articles with high interface strength.

Abstract: 4-component thermoplastic molding compositions which are easily processed on injection molding or extrusion machinery consisting essentially of amorphous copolyamides which can be produced from inexpensive raw materials, inexpensive elastomeric block polyetherpolyamides and block polyetheresterpolyamides as well as commercially available modified copolyolefins and are distinguished by high cold impact resistance, good ductility, variably adjustable rigidity which is independent of the degree of humidity and excellent pigment compatibility as well as by good stress crack resistance, thermal and dimensional stability.

Abstract: Molding compositions of thermoplastic plasticizer-containing polyamides exhibit greatly reduced migration of plasticizer or no migration at all due to having 0.1 to 20% by weight of sterically hindered carbodiimides of the formulaR.sub.1 --N.dbd.C.dbd.N--[R.sub.2 --N.dbd.C.dbd.N].sub.2 --R.sub.3wherein n is 0 to 100; R.sub.1 and R.sub.3 are individually a monovalent radical taken from the class consisting of aliphatic having 1 to 20 carbon atoms, cycloaliphatics having 6 to 20 carbon atoms, and aromatics having 8 to 20 carbon atoms and also having substituents; and R.sub.2 is a divalent radical taken from the class consisting of aliphatics having 1 to 20 carbon atoms, cycloaliphatic having 6 to 20 carbon atoms, and aromatics having 8 to 20 carbon atoms and also having substituents.

Abstract: Thermoplastic polyamide molding materials containing impact resistance-providing additives, which are reinforced with glass fibers and are colored with dyes and pigments, comprise a mixture of components A and B.Component A comprises glass fiber-containing polyamide and component B comprises polyamide with impact resistance-providing additives and can also contain dyes, pigments, heat and light-stabilizers, as well as processing agents.Due to the separate addition of the glass fibers and the impact resistance-providing additives, pigments, etc. to the polyamide, the conventional reduction in mechanical properties, such as impact resistance and notch toughness, on the addition of all the other components to the polyamide, is surprisingly prevented.