DD220857A1 - THERMOPLASTIC COMBINATIONS BASED ON POLYMERIC ALDEHYDE - Google Patents

Abstract

A design material based on polymeric aldehydes should be developed which has good heat distortion resistance, stiffness and toughness. These requirements are solved by thermoplastic combinations based on polymeric aldehydes and norbornene-ethylene copolymers, optionally with the addition of stabilizers, lubricants, elastomers, thermoplastics and Verstaerkerstoffen. Suitable polymeric aldehydes are homopolymers such as polyformaldehyde, polyacetaldehyde, polyglyoxal, polytrifluoroacetaldehyde or copolymers with aldehydes such as formaldehyde-amide copolymers. The thermoplastic combinations are suitable for use in mechanical engineering, vehicle construction and precision engineering.

Description

VEB Leuna-Werke "Walter Ulbricht"

; -83160: '/. '. "... '..' Title of the invention ·

Thermoplastic combinations based on polymeric aldehydes Field of application of the invention; , .. '

The invention relates to thermoplastic combinations based on polymeric aldehydes which can be used under high continuous loads at elevated temperature.

Characteristic of the known technical solutions>

It is known that polymeric aldehydes based on .formaldehyde. , by ionic polymerization of formaldehyde (W: »Kern, Angew Ghem. (73 (1961), 17T, BE-PS 590243; BE-PS 608622) or trioxane (US-PS 2,795,571, US-PS 2,947,727; The heat resistance of polyformaldehyde is limited by the drop in rigidity at elevated temperature to a maximum continuous service temperature of about 358 K. It is also known that the heat resistance of polyformaldehyde can be increased by adding fillers or glass. -

fibers (W. Schütte, Kunststoffe 66 (1976), 604). It is known that orbornene -ethylene copolymers are hard and brittle thermoplastics (US Pat. No. 2,799,668, British Pat. No. 777,414, DD-FS 109224). ^

A modification of the material properties of norbornene-ethylene copolymers can be achieved by combination with elastomers (DD-PS 129799). '

Object of the invention

The aim of the invention are thermoplastic combinations which simultaneously have a good heat resistance, stiffness and toughness.

Explanation of the essence of the invention

The invention has for its object to develop based on polymeric aldehydes a construction material, which at the same time has a good heat resistance, stiffness and toughness.

This Aufgäbe is achieved by thermoplastic combinations based on polymeric aldehydes, optionally with the addition of stabilizers and lubricants, the combinations according to the invention 5 to 95 % of a polymeric aldehyde, 95 to 5% of a Worbornen-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 Kärkerstoffs »

As polymeric aldehydes, polyformaldehyde, polyacetaldehyde, polyglyoxal, polytrifluoroacetaldehyde and corresponding copolymers with aldehydes, such as formaldehyde-amide copolymers, are advantageously used. As norbornene-ethylene copolymers, copolymers having a norbornene content of 30 to 70 mol % are most suitable * As fibrous

Reinforcement fabrics can be used for combinations of glass fibers, asbestos fibers, mineral fibers and organic Ilochmodulfasern. Suitable particulate reinforcing materials are calcium carbonate, silicates, metal powders, metal oxides, salts, microglass beads, thermoset microspheres and modified thermoplastic regenerants. To improve the impact strength and impact strength of the combinations, elastomers such as natural rubber, elastomeric ethylene and / or terpolymers or graft copolymers, polybutadiene, butadiene copolymers and terpolymers _; or "Pfropi5kopolymere, chlorinated and chlorosulfonated polyethylene, polyisobutylene, polychloroprene,, chlorohydrin rubber, butyl rubber, silicone rubber, Pluorkarbon- rubber, Nitrosokautschuk, Karboxynitrosokautsehuk, Polyakrylatkautschuk or mixtures of these elastomers in concentrations up to 25 % . The preparation of the thermoplastic combinations other than polymeric aldehydes and urorbornene-ethylene copolymers, optionally with the addition of stabilizers, lubricants, elastomers, thermoplastics and reinforcing agents in single-screw or twin-screw extruders of good homogenizing effect at processing temperatures preferably in the range 480 to 505 K. The components can be dosed simultaneously be, or it happens. derDosierung a pre-homogenization of the individual components. 'The composition of the combinations is determined by the property requirements of the specific field of application.' In combinations of polyformaldehyde and Norbornfn-ethylene copolymers heat distortion, hardness and strength of the combinations with increasing content of lorbornene-ethylene copolymer increase. The addition of elastomers provides an additional improvement in impact resistance, combinations based on polymeric aldehydes and norbornene-ethylene copolymers. -

Fiber-shaped and particulate reinforcing materials increase the hardness and dimensional stability of the combinations »

embodiments

In the embodiments, a norbornene-ethylene copolymer having a norbornene content of 50 mol % and a melt index of 0.3 g / 10 min at 483 K / 2, -1 kp ν and a formaldehyde-amide copolymer;

with the following properties: Melt index (g / 10 min at 48 K / 2.1 kp). : 11.6.: Density (g / cm ³ ): 1.4041

Bending modulus (K / mm ² ),:. 2260

Heat resistance according to Martens (K): 320

'Example 1 . '.'';'' - .. '. "'.';^'.'; ·: - - '...

10 parts Porraaldehyd- ^ amide copolymer are homogenized with 30 parts of norbornene-ethylene copolymer in the extruder at 435 K and sprayed at a melt temperature of 505 K to test specimens, - The combination has the following properties: Schiheizindex,. (g / 10 min · at 483 K / 2.1 kp): 7.6 Density (g / cm ³ ) "" 1. "" 1.2510 Bend modulus (N / mm ² ): 2722

Heat resistance according to Martens (K): 336

Example 2 λ

30 parts of formaldehyde-amide copolymer, 25 parts of norbornene-ethylene copolymer, 30 parts of stearic acid-coated chalk and 15 parts of ethylene-vinyl acetate-capolymer (vinyl acetate content 35% by weight, gel content 4 %) are added after mixing in a twin-screw extruder homogenized at a melt temperature of 502 K and sprayed at 507 K to test specimens. The combination has the following properties:;

Scbmelzindex (. G / 10 min at 483 C / 2.1 ^kp): 3.6 Density (g / cm ^3): 1.4018

Bending modulus (I / mm ² ); : 2750

Heat resistance according to Martens (K): '

Claims (1)

Invention claim> ** ·· -. ''. ' ^;> "· ^-... '.' - · '.: ^; - ^: -ΐ' · Thermoplastic combinations based on polymeric aldehydes, optionally with the addition of stabilizers and lubricants, characterized in that the combinations comprise 5 to 95% of a polymeric aldehyde, 95 to 5% of a horbornene-ethylene copolymer and optionally 1 to 25 % of an elastomer and / or other thermoplastics and / or. or 1 to 50 % of a fibrous and / or particulate reinforcing material. Therapy combinations according to item 1, characterized in that the combinations contain, as polymeric aldehydes, homopolymers such as polyformaldehyde, polyacetaldehyde, polyglyoxal, polytrifluoroacetaldehyde or copolymers with aldehydes such as formaldehyde-amide copolymers.