DD214623A1 - THERMOPLAST COMBINATIONS - Google Patents

Abstract

A construction material based on heat resistant polyolefins should be developed which has high heat distortion resistance, solvent resistance, stiffness, toughness, and good dielectric properties. These requirements are achieved by thermoplastic combinations based on branched polyolefins and norbornene-ethylene copolymers, optionally with the addition of stabilizers, lubricants, elastomers, thermoplastics and Verstaerkerstoffen. As branched polyolefins, polypropylene, polybutene-1 and poly-4-methylpentene-1 are preferably suitable. The thermoplastic combinations can be used in electrical engineering, electronics, precision engineering, mechanical engineering, chassis construction as well as in the construction of tanks.

Description

VEB Leuna-Werke Leuna, December 4, 1982

"Walter Ulbricht"

LP 82 116

Title of the invention Thermoplastic combinations Field of application of the invention

The invention relates to thermoplastic combinations which can be used under high continuous loads at high temperatures.

Characteristic of the known technical solutions

It is known that horbornene-ethylene copolymers are hard and brittle thermoplastics (US Pat. No. 2,799,668, British Pat. No. 7,77414, German Pat. No. 109,224). Such thermoplastics have insufficient resistance to impact and impact stress. Furthermore, it is known that the impact strength of norbornene-ethylene copolymers can be improved by modification with elastomers (DD-PS 129 799, 0 08 L / 235 389/4, C 08 L / 235 390/0, 0 08 L / 235 391/7, C 08 L / 235 393/3). The heat resistance, dimensional stability, hardness and rigidity

MRi 1983 * 079823

The performance of norbornene-ethylene copolymers is improved by combinations with particulate reinforcing agents (C08L / 235 394/1). An increase in solvent resistance is achieved by combination of norbornene-ethylene copolymers with polyamides (C08L / 235 392/5). It is also known to improve polypropylene strength, toughness and stiffness by addition of nucleating agents (DE-PS 2,536,348). Compressive strength and hardness of polypropylene can be increased by reinforcement with glass fibers, glass beads or talc (J. Robinson, Plastics 66 (1976), 506-510, ü Schurr, Plastverarbeiter 29 (1978), 351-З6О). Increased toughness of polypropylene can be achieved by combination with elastomers (T. Laus, Angew. Makromolekulare Chem. 60 (1977), 87-110). It is also known to increase the hardness of polybutene-1 by adding fillers (T. Reed, Plast., Technol. 12 (1966) 2, 38). Thermoplastic combinations for special applications, which also have a high heat resistance, solvent resistance, stiffness and toughness, are not yet known.

Object of the invention

The aim of the invention are thermoplastic combinations which at the same time possess high heat resistance, solvent resistance, stiffness, toughness and good dielectric properties.

Explanation of the essence of the invention

The invention has for its object to develop based on heat-resistant polyolefins a construction material, which also has a high heat resistance, solvent resistance, stiffness, toughness and good dielectisohe properties.

This object is achieved by thermoplastic combinations based on branched polyolefins, optionally with the addition of stabilizers and lubricants, according to the invention the combinations 5 to 95 % of a branched polyolefin, 95 to 5 % of a norbornene-ethylene copolymer and optionally 1 to 25 % of an Elasts and / or another thermoplastic and / or 1 to 50% of a fibrous and / or particulate reinforcing material.

The branched polyolefins used are preferably polypropylene, polybutene-1, poly-4-methylpentene-i and / or polyhexene-1. Copolymers with a norbornene content of 30 to 70 mol% are the most suitable norbornene-ethylene copolymers.

As fibrous reinforcing materials can be used for the combinations of glass fibers, asbestos fibers, mineral fibers and organic high modulus fibers; Calcium carbonate, silicates, metal powders, metal oxides, salts, glass microspheres, thermoset microspheres and modified thermoplastic regenerants are suitable as particulate reinforcing substances.

In order to improve the impact strength and notched impact strength of the combinations, elastics such as natural rubber, elastomeric ethylene co- and terpolymer or graft copolymers, polybutadiene, elastomeric butadiene copolymers and terpolymers or graft copolymers, chlorinated and chlorosulfonated polyethylene, polyisobutylene, polychloroprene, chlorohydrin rubbers, Butyl rubber, silicone rubber, fluorocarbon rubber, nitrosocarbon, Karboxynitrosokautschuk, Polyakrylatkautschuk or mixtures of these elastomers in concentrations up to 25 % can be used.

The preparation of the thermoplastic combinations of branched polyolefins and norbornene-ethylene copolymers, optionally with the addition of stabilizers, lubricants, elastomers, thermoplastics and reinforcing materials takes place in single-screw

or twin-screw extruders with good homogenization effect at processing temperatures preferably in the range 485 to 525 K. In this case, the components can be dosed simultaneously or there is a pre-homogenization of the Ejnel components before dosing.

The composition of the combinations is determined by the specific requirements of the specific field of application.

Additions of branched polyolefins to 30 % lead to a significant improvement in the solvent resistance of ethylene-norbornene copolymers, while the essential material properties of Norboinen-ethylene copolymers such as strength, modulus, hardness and heat resistance are largely retained.

Conversely, the addition of horbornene ethylene copolymers to branched polyolefins to a concentration of 30% by weight results in a significant increase in the strength, modulus, and hardness of the branched polyolefin without a significant decrease in toughness. Addition of elastomers provides additional improvement in the impact and notched impact strength of the branched polyolefin / norbornene-ethylene copolymer based combinations.

Pear-shaped or particulate reinforcing materials increase the hardness and dimensional stability of the polymer combinations. The highest heat resistance is achieved in combinations based on poly-4-methylpentene-1 and norbornene-ethylene copolymers.

embodiments

example 1

15 parts of an ITorbornen-ethylene copolymer with a norbornene content of 50 Шо1% and a "melt index of

2.7 g / 10 min at 483 K and 10.3 kp and 85 parts of polypropylene having a melt index of 30.4 g / 10 min · at 483 K and 10.3 kp are homogenized in the extruder at a melt temperature of 500 K. and sprayed to test bars. The combination has the following material properties:

Combination comparison

polypropylene

Tensile strength 36 N / mm ² 22 N / mm ²

Bend modulus 1532 N / mm ² 1282 N / mm ²

Impact resistance without breakage without breakage

Ball pressure hardness 65 N / mm ² 31 N / mm ²

2 2

Bending stress 50 N / mm 32 N / mm

Heat resistance 381 K 368 K

to Vioat

Example 2

70 parts of a norbornene-ethylene copolymer according to Example 1 are homogenized with 30 parts of polypropylene according to Example 1 in an extruder at a melt temperature of 510 K and sprayed to test bars. The combination has the following properties:

Tensile strength Impact resistance Impact resistance

Heat resistance according to Vicat

Solvent resistance Strength after cylinder storage

combination comparison Norbornene-ethylene copolymer 53 N / mm ² ρ 14 mJ / mm 60 N / mm ² о 15 mJ / mm ρ 1.2 mJ / mm ρ 2.1 mJ / mm 401K 406 K 20.3 N / mm ² 7 N / mm ²

Example 3

52.5 parts of a norbornene-ethylene copolyester according to Example 1, 22.5 parts of polypropylene according to Example 1 and 25 parts of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 42 % and a melt index of 0.5 g / 10 min 463 K / 2.1 kp are homogenized in the extruder at a melt temperature of 500 K. The combination has the following properties

Bending stress 50 H / mm

Impact resistance 47 mJ / mm Impact resistance 9 mJ / mm B-flexural modulus 1600 N / mm ²

Example 4

70 parts of isotactic polybutene-1 are homogenized with 30 parts of a norbornene-ethylene copolymer according to Example 1 in the extruder at 595 K and sprayed to test bars. The combination has the following properties:

Combination comparison

Polybutene-1

Tensile strength 44 N / mm ² 20 W / mm ²

Bending modulus 1750 N / mm ² 1200 N / mm ²

Ball pressure hardness 75 N / mm ² 35 N / mm ²

Impact resistance 74 mJ / mm without breakage

Heat resistance 383 K 369 K

to Vicat

Example 5

60 parts of a stabilized with diphenyl-p-phenylenediamine poly-4-methylpentene-1 are homogenized with 40 parts of a norbornene-ethylene copolymer in the extruder at 525 K and sprayed into test bars. The combination has the following properties:

Combination comparison

Poly-4-methylpentene-1

Tensile strength 55 H / mm ² 28 W / mm ²

Bend modulus 2400 N / mm ² 1300 N / mm ²

Ball hardness 120 N / mm ² 75 N / mm ²

Heat resistance 425 K 451 K

to Vicat

Claims (2)

invention claim 1. Thermoplastic combinations based on branched polyolefins, optionally with the addition of stabilizers and lubricants, characterized in that the combinations of 5 to 95 % of a branched polyolefin, 95 to 5 % of a norbornene-ethylene copolymer and optionally 1 to 25 % of an Elast and / or another herbalmold and / or 1 to 50 % of a fibrous and / or particulate reinforcing material. 2 · thermoplastic combinations according to item 1, characterized in that the combinations contain as branched polyolefins polypropylene, polybutene-1, poly-4-methylpentene-i and / or polyhexene-1.