CS200765B1 - Process for the production of articles from polyvinyl chloride, both milled and dipped - Google Patents

Abstract

A method for producing articles from lightened and simultaneously softened polyvinyl chloride, the object of the invention is to produce articles from lightened and simultaneously softened polyvinyl chloride by extrusion and injection molding technology. This purpose is achieved by extruding a mixture of suspension or block PVC containing lubricants, fillers, stabilizers, decomposition activators of blowing agents, and possibly pigments in the simultaneous presence of blowing agents, plasticizers and modifiers at processing temperatures of 130 to 220 °C. The articles produced in this way can be used in various areas of industry and agriculture.

Description

( ⁵⁴ ) Manufacturing of articles made of polyvinyl chloride, both milled and dipped

The present invention is directed to the manufacture of articles made of poly (vinyl chloride) and molded polyvinyl chloride by extrusion and injection technology. This is accomplished by providing a slurry or block PVC blend containing lubricants, fillers, stabilizers, activators, the decomposition of the blowing agents, and possibly pigments ea in the presence of blowing agents, wetting agents and modifying agents, displaces at spray temperatures of 130 to 220 ° C. The articles produced in this way can be used in a wide variety of industries and in agriculture.

The present invention relates to the manufacture of articles made of lightweight and simultaneously softened polyvinyl chloride (PVC only), using simple processing techniques such as e.g. extrusion and injection.

The classic method of manufacturing articles made of lightweight, softened PVC consists in preparing a paste based on emulsion PVC and containing blowing agents, the processing of which requires special equipment and technologies. Softened suspension-based products block PVC, which are produced by conventional technologies, eg by extrusion or injection, they usually contain a maximum of 50 wt. parts of plasticizer per 100 wt. parts of PVC, so that an agglomerate or granulate of the PVC mixture can be used for processing, wherein the manufacture of the lightweight products from such narrowly blended mixtures is essentially of no technical sense.

According to the process of the present invention, articles can be produced from lightweight, softened PVC by simple technological processes, e.g. by extrusion, the starting material for the manufacture of these articles being a high-blown, powdered blend of suspension or block PVC.

The method for producing articles made of lightweight and concurrently softened PVC is preferably extruded according to the invention such that the mixture of suspension and / or block polyvinyl chloride with high particle porosity and a K-value of 60-75, preferably 70-75, containing lubricants, fills %, preferably microfine calcium carbonate in an amount of 5 wt. d. per 100 wt. d. polymer, stabilizers and activators of blowing agents based on inorganic and / or organic metal salts in amounts up to 5 wt. d. per 100 wt. d. % of polymer, and / or pigments, in the presence of blowing agents, preferably azodicarbonamide, in an amount of 0.1 to 0.2 wt. d. per 100 wt. d. % of polymer, plasticizer, preferably ester type in an amount of 50 to 100 wt. d. per 100 wt. d. % of the polymer and the additive, preferably acrylates, are extruded at processing temperatures of 130 ° C to 220 ° C, preferably at 150 ° C.

Suspended and / or block PVC with high particle porosity is used as the base material for the manufacture of articles made of lightweight, softened PVC, stabilizers preferably using basic sulphates and / or basic lead stearates, which can also act as activators of blowing agent decomposition. as lubricants, e.g. stearin, paraffins or montene waxes. In particular, ester plasticizers, e.g. dioctylphthalate. The filler may be micronized, surface-treated calcium carbonate and, if desired, pigments may also be used to color articles. Azodicarbonamide may be used as the blowing agent, and e.g. an acrylate-based modifier can be applied in an amount of e.g. 5 wt. d., wherein the mixture is preferably mixed on a high-speed fluid mixer and a final mixing temperature of e.g. 95 ° C and after cooling e.g. at 40 ° C, a free-flowing mixture is obtained which can either be processed directly by extrusion of the alpbo granulate and then processed e.g. injection molded and simultaneously softened articles at processing temperatures, preferably

200 705 at 150 ° C.

The advantage of the above-mentioned method of production of articles made of lightweight and at the same time softened PVC is the possibility of using simple processing technologies, such as e.g. extrusion or injection molding, using a high-soaked powder and bulk mixture as the starting mixture. The manufactured articles are characterized by low hardness and specific weight, high flexibility and at the same time lowering and lower material costs.

Example 1

A 100 wt.% Dry mix was prepared on a high-speed fluidized bed mixer. d. suspension PVC with a K-value of 71 and a high porosity of the particles, 2.5 wt. d. a stabilizer comprising tribasic sulfate and dibasic lead stearate and calcium stearate and lubricating agents based on paraffin waxes, 5 wt. d. micronised calcium carbonate filler, 80 wt. d. dioctyl phthalate as plasticizer, 5 wt. d. polymethyl methacrylate as modifying additive and 0.5 wt. d. azodicarbonamide blowing agents, the mixture is stirred until a temperature of 95 ° C is reached and then cooled to 40 ° C. From the finished powder mixture, a rectangular cross-sectional profile is made on a single-screw extruder at temperatures of 150 ° C, 165 ° C, 175 ° C, 185 ° C set in each machine zone starting from the hopper and at a nozzle of 180 ° C. The profile thus prepared has a specific gravity of 850 kg / m @ 2 and a hardness of 60 ShA.

Example 2

The mixture prepared as in Example 1 is extruded on a twin screw extruder through a rectangular die at temperatures of 140 ° C, 160 ° C, 160 ° C, 150 ° C, 160 ° C set in each zone starting from the hopper and on the die at 155 ° C. The profile thus prepared has a specific gravity of 870 kg / m 2 and a hardness of 58 ShA.

Example 3

The mixture prepared as in Example 1 is rolled on a two-roll calender at 130 ° C until the rolls are wrapped and subsequently pressed at 150 ° C for 5 minutes. The board thus prepared has a density of 820 kg / jp and a hardness of 54 ShA.

Example 4

A dry blend having a 100 wt. d. K-value 70 PVC with high particle porosity, 2.0 wt. d. a stabilizer comprising barium sulphates and lead stearates and stearic acid and paraffinic acid lubricants, 5 wt. parts by weight of micronized calcium carbonate filler, 95 wt. d. dioctyl phthalate as plasticizer, 5 wt. d. polymethyl methacrylate as modifying additive and 0.5 wt. d. Blowing Agent

200,700 azodicarbonamide, the mixture is stirred until a temperature of 90 ° C is reached and then cooled to 40 ° C. A flat profile of a rectangular cross-section is produced on the twin screw extruder at temperatures of 140 ° C, 160 ° C, 160 ° C, 170 ° C, 150 ° C set in each machine zone starting from the hopper and at a 140 ° G die. The profile thus prepared has a specific gravity of 830 kg / m @ 2 and a hardness of 49 ShA.

Example 5

The mixture prepared according to Example 4 aa is injected into a double mold at an injection molding machine at temperatures of 170 ° C, 170 ° C, 180 ° C on bands starting from the hopper and at a tip of 1.90 ° C, mold 40 ° C. The flat circles thus obtained have a hardness of 46 ShA and a specific gravity of 820 kg / m < 3 >.

Claims (1)

OBJECT OF THE INVENTION A method for producing articles from drawn and co-plated polyvinyl chloride, preferably by extrusion technology, characterized in that the mixture of suspension and / or block polyvinyl chloride with a high particle porosity and a K-value of 60-75, preferably 70-75, containing lubricating, preferably microfine calcium carbonate in an amount of 5 wt. parts per 100 wt. d. polymer, stabilizers and activators of blowing agents based on inorganic and / or organic metal salts in amounts up to 5 wt. d. per 100 wt. d. % of polymer and / or pigments in the presence of blowing agents, preferably azodicarbonamide in an amount of 0.1 to 2.0 wt. d. % of polymer, wetting agent, preferably ester type in an amount of 50 to 100 wt. d. per 100 wt. d. polymer and modifying additives, preferably acrylates, extrudes at processing temperatures of 130 ° C to 220 ° C, preferably at a temperature of 1.50 ° C.