Polyetheylene moulding compound suitable as a pipe material with excellent processing properties

Abstract

The invention relates to a polymeric molding compound made from a first ethylene polymer (A) and from a second ethylene polymer (B) which is particularly suitable for producing thick-walled large-caliber pipes, wherein the molding compound comprises an amount in the range from 55 to 75% by weight of the first ethylene polymer (A) and an amount in the range from 25 to 45% by weight of the second ethylene polymer (B), based in each case on the total weight of the molding compound, where the first ethylene polymer (A) is a copolymer of ethylene with a 1-olefin having a total number of carbon atoms in the range from 4 to 10 as comonomer, and with a proportion of from 0.2 to 5% by weight of comonomer, based on the weight of the first ethylene polymer (A), and with a wide bimodal molar mass distribution, and where the second ethylene polymer (B) is a copolymer made from ethylene units and from a 1-olefin having a number of carbon atoms in the range from 4 to 10, which has a bimodal molar mass distribution differing from that of the first ethylene polymer (A). The invention further relates to a high-strength pipe made from this molding compound, and to its use for the transport of gas or water.

Description

technical field

[0001] The present invention relates to polymer molding compounds produced from a first ethylene polymer (A) and a second ethylene polymer (B). The processing performance of the molding compound makes it especially suitable for the manufacture of thick-walled and large-diameter pipes. Background technique

[0002] Polyethylene has been widely used in the manufacture of pipes, for example for gas conveying systems or water conveying systems, since such pipes require materials with high mechanical strength, high corrosion resistance and long-term durability. There is a great deal of literature describing such materials with a wide variety of properties and methods of making them.

[0003] EP-A-603935 already describes molding compounds with a bimodal molar mass distribution based on polyethylene, which are especially suitable for the manufacture of pipes. However, pipes made of the molding compound proposed in this document are poor in internal pressure long-...

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