一种金属管，其包括聚酰胺模制组合物的层，重量％含有至少50聚酰胺组分，它由以下几部分组成：按重量计的聚酰胺I）60〜98质量份为10〜70毫克当量/千克的羧端基 和具有相对溶液粘度·相对，根据ISO 307使用在间甲酚0.5重量％的溶液在25℃下的至少1.90，并具有II）2〜40份（重量）的确定 这是由以下单体多胺 - 聚酰胺接枝共聚物制备：a）0.5〜25重量％，基于总单体混合物，具有至少4个氮原子的多胺，和b）75至99.5重量％， 基于总单体混合物，从内酰胺，E-氨基羧酸和/或二胺和二羧酸的等摩尔组合的形成聚酰胺的单体，条件是在该范围的接枝共聚物的氨基浓度为100至2500毫克当量/千克lieg t，其中所述重量份的I）和II）的总和为100，是用于used-用水解作用的介质接触。 这延长了使用寿命和改善高温的耐受性是可能的。

A metallic tube containing a layer of a polyamide molding composition, the weight .-% contains at least 50 a polyamide component, which comprises the following components:
I) 60 to 98 parts by weight of a polyamide containing 10 to 70 meq / kg of carboxyl end groups and a relative solution viscosity η _rel, determined according to ISO 307 using a 0.5 wt .-% solution in m-cresol at 25 ° C, has at least 1.90, and
II) 2 to 40 parts by weight of a polyamine-polyamide graft copolymer which is prepared from the following monomers:
a) 0.5 to 25 wt .-%, based on the total monomer mixture, of a polyamine having at least 4 nitrogen atoms and
b) from 75 to 99.5 wt .-%, based on the total monomer mixture, polyamide-forming monomers selected from lactams, ω-aminocarboxylic acids and / or equimolar combinations of diamine and dicarboxylic acid,
with the proviso that the amino group concentration of the graft copolymer in the range from 100 to 2500 meq / kg,

wherein the sum of the parts by weight of I) and II) is 100,
is used- for contact with a hydrolyzing acting medium. This extended service life and improved tolerance of high temperatures are possible.