DD230828A1 - HOLLOW BODY FROM THERMOPLAST - Google Patents

Abstract

Depending on the field of application, hollow bodies made of thermoplastic must meet various requirements. Constant temperaturbestaendigkeit, dimensional accuracy, transparency, mechanical strength, resistance to various media such as hot water, acids, alkalis, saline solutions, organic substances, cosmetics, drinks, etc. are not provided by the known technical solutions in sufficient quantity or can be reached only with great effort , The inventive Hohlkoerper of ethylene-norbornene copolymers have a favorable property spectrum, which by modification of the starting polymer the respective application, for. B. water tank for hot water boiler, hollow body for the heating and ventilation of motor vehicles, packaging for drinks and cosmetics, can be adjusted. The hollow bodies are produced by known processes, such as blowing and injection blow molding.

Description

By modifying the starting material, it is possible to use non-transparent hollow bodies that resist organic growth. Solvents, oils and fats are resistant to manufacture. The melt index of the ethylene-norbornene copolymer is in the range of 0.1 g / 10 min to 40 g / 10 min, preferably between 0.5 g / 10 min and 20 g / 10 min, at 275 ° C and 2.1 kp load. The production of the hollow body is carried out with blow molding or injection blow molding machines. The melt temperature is in the extrusion of the melt tube or in the production of the preforms 200 to 300 ⁰ C, preferably 240 to 280 ° C. One- or two-dimensional stretching is possible. In this case, the temperature of the preform 160-260 ⁰ C.

Exemplary embodiments Example 1

Ethylene-norbornene copolymer having a Narbornenanteil of 55MoI .-%, a glass transition temperature of 145 ° C and a melt index of 2 g / 10 min is extruded on a hollow body blow molding machine with 60 mm single screw extruder and head at a melt temperature of 250 ° C to a tube and blown to a 10 l container for hot water boiler. The mass of the hollow body is 1150g, the average wall thickness 4mm.

Example 2

Ethylene-norbornene copolymer having a Narbornenanteil of 60 mol .-%, a glass transition temperature of 152 ° C and a melt index of 5g / 10 min is injected at a melt temperature of 255 ° C into preforms of 45 g weight. These preforms are blown after cooling to 19O ⁰ C to bottles of 0.51 volume and about 1.5 mm wall thickness. By the stretching process occurring, the toughness of the material is improved. The bottles are suitable for food and can be sterilized with saturated steam at 120 ° C.

Example 3

A compound of 55Ma .-% of an ethylene-norbornene copolymer having a norbornene content of 50 mol .-% and a glass transition temperature of 138 ⁰ C and 45 wt .-% of a 6-polyamide having a solution viscosity of 3.7, the melt index of3 , 8g / 10min, is extruded to a tube on a hollow-core blow molding machine with a 45 mm single-screw extruder and blown into a non-cylindrical hollow body with a volume of 4.51 and wall thicknesses between 2 and 3.5 mm for motor vehicle heaters. The hollow body is petrol and oil resistant, dimensionally stable up to 12O ⁰ C and weighs 320g.

Claims (3)

-1- 595 88 Invention claim: 1. hollow body made of thermoplastic material, characterized in that the hollow body contain ethylene-norbornene copolymers or mixtures of ethylene-norbornene copolymers with elastomers, other polymers and additives. 2. Hollow bodies according to item 1, characterized in that the copolymers contain stabilizers or stabilizer mixtures, dyes or pigments. 3. hollow body according to item 1, characterized in that the copolymers elastomers or other polymers or copolymers such as natural rubber, elastomeric ethylene co- and terpolymers or graft copolymers, polybutadiene, elastomeric butadiene co- and terpolymers or graft copolymers, chlorinated and chlorosulfonated polyethylene, polyisobutylene, polyisoprene, polychloroprene, chlorohydrin rubber, butyl rubber, silicone rubber, polysulfide rubber, fluorocarbon rubber, nitroso rubber, carboxy cyrositroc rubber, polyacrylate rubber, polyurethane rubber, polyethylene, polypropylene, polybutene-1, ethylene-vinyl acetate copolymers, polyamides, thermoplastic polyesters, Polystyrene, polycarbonate, polyphenylene oxide, polysulfones or mixtures thereof. Field of application of the invention The invention relates to thermoplastic hollow bodies for use as liquid containers in technical installations or in consumer goods and as packaging materials. These hollow bodies are characterized by dimensional stability. They are resistant to a variety of media, such as hot water, acids, alkalis, cosmetics, detergents, aggressive gases and, if modified, also to petrol, oils and oily media. The continuous use temperature is at least 100 ⁰ C. Characteristic of the known technical solutions As a material for hollow bodies for receiving liquids and gases, which are used in technical equipment, consumer goods and packaging materials, thermoplastics have prevailed due to the economic favorable shape. Depending on the type of medium, the pressure and the temperature, the most varied requirements are placed on the materials used. Despite a variety of possible materials, the solutions used in practice are often unsatisfactory. So is z. B. the maximum continuous service temperature of many, long used for the production of hollow bodies thermoplastics such as polybutylene terephthalate, polybutene-1, all straight-chain polyamides, polyethylene, polyvinyl chloride, polystyrene and polymethylmethacrylate below 100 ⁰ C (K.-U. Buehler, Spezialplaste, Akademie-Verlag Berlin 1978). Polypropylene to 120 ⁰ C can be used, is nicrvt used when transparency is required (A.Schley, A.Schwarz, Kunststoffhandbuch, Vol. IV, Polyolefins, Carl-Hanser-Verlag, Munich, 1969). 6- and 6,6-polyamides are not sufficiently resistant to hydrolysis at higher temperatures, because of their tendency to absorb water from the environment, they are also not very dimensionally stable (A. Müller, Kunststoffhandbuch Bd.Vl, 1969, Carl Hanser Verlag Munich). Object of the invention The aim of the invention is to produce hollow body made of thermoplastic with advantageous properties such as dimensional stability, strength, low weight, transparency and resistance to hot water, acids, alkalis and salt solutions. Explanation of the essence of the invention The object of the invention is to find a suitable thermoplastic material for hollow bodies, which are characterized by dimensional stability, strength, light weight, transparency and resistance to media such as hot water, acids, alkalis, saline solutions, cosmetics, aerosols, oils. This object is achieved by hollow bodies made of thermoplastic, wherein according to the invention contain the hollow body ethylene-norbornene copolymers or mixtures of ethylene-norbornene copolymers with elastomers, other polymers and additives. The copolymers or their mixtures are melted and shaped by blowing or injection blow molding into hollow bodies. The hollow body production can be associated with a one- or two-dimensional stretching process. Advantageously, the copolymer contains 25 to 90 mol%, preferably 40 to 80 mol%, of nerbornene. Optionally, 0.02 to 3.0 wt .-%, preferably 0.05 to 1.0 wt .-%, of a stabilizer or stabilizer mixture. Furthermore, dyes, pigments, elastomers or other polymers or copolymers such as natural rubber, elastomeric ethylene copolymers and terpolymers or graft copolymers, polybutadiene, elastomeric butadiene copolymers and terpolymers or graft copolymers may advantageously be used, depending on the intended use , chlorinated and chlorosulfonated polyethylene, polyisobutylene, polyisoprene, polychloroprene, chlorohydrin rubber, butyl rubber, silicone rubber, polysulfide rubber, fluorocarbon rubber, nitroso rubber, carboxy cyrositroc rubber, polyacrylate rubber, polyurethane rubber, polyethylene, polypropylene, polybutene-1, ethylene-vinyl acetate copolymers, polyamides, thermoplastic polyesters , Polystyrene, polyphenylene oxide, polysulfone, polycarbonate or mixtures thereof.