SU1139639A1 - Method of obtaining multilayer plastic (modifications) - Google Patents

Abstract

1. A method of producing a multilayer plastic by extruding melts of amorphous and amorphous-crystalline polymers, cooling and orientation at the same temperature, characterized in that, in order to increase the strength of the plastic and simplify the process, a mixture of melts of these polymers is used at. each 10-90 wt.%, it is cooled in the temperature range from a temperature 10 ° C below the melting temperature of the amorphous-crystalline polymer to the glass transition temperature of the amorphous polymer, and after orientation it is further packaged in the temperature range from the orientation temperature to the melting temperature -crystalline polymer. 2. A method of producing multilayer plastic by extruding melts of two thermoplastic polymers by cooling and orientation at the same temperature, different TejM, which, in order to increase firmly (L plastic and simplify the process, use a mixture of melts of amorphous-crystalline polymers with different forging temperature at a content of each 10- 90 wt.%, It is cooled in the temperature range from the melting temperature of the low-melting polymer to from the temperature below it, and after orientation, an additional 0 is packed in the region of These temperatures range from the melting point of the low melting polymer to i, the temperature at the lower temperature, and the melting of the high melting polymer.

Description

The invention relates to the processing of thermoplastic polymers, specifically to the production of multilayer plastics, and can be used in the chemical industry, man-building, and agriculture. A known method of producing a multilayer plastic by co-extrusion through a flat-slot head: a multi-collector or a conventional slotted one, equipped with an adapter (distribution block) and a multiplier. In this way, multi-layer plastic is obtained containing 249 consecutive layers of polystyrene and polymethyl methacrylate 11-. The closest to the present invention is a method for producing a multilayer plastic by extruding a melt of two thermoplastic polymers (amorphous and amorphous crystal) by cooling and orientation at the same temperature. 23 In this method, plastic is obtained by layer-by-layer extrusion of polypropylene (PP) and polystyrene (PS). ) followed by simultaneous cooling and biaxial orientation by stretching. The content of PP and PS in plastic is from 80; 20 to 20:80 wt.%. At the same time, the number of layers remains constant, i.e. as the composition changes, the thickness of the polypropylene and polystyrene layers in a multilayer plate changes, and each layer consists of a homopolymer: PP or PS. Multilayer plastic (125 layers) is obtained, having a tensile strength from 6.0 to 11.2 kg / mm. Plastic produced by this method is characterized by insufficiently high strength values, which limits its scope (used mainly as a packaging material). The method is very complicated, since to obtain multilayer plastics with more than two layers or to obtain multilayer plastics consisting of more than two different polymers, complex technological equipment is needed. For example, the number of extruders combined into one unit for producing a complex plastic is equal to the number of polymers that make up the complex plastic. 92 In addition, the polymers used to obtain a multilayer plastic must have sufficient adhesion. Often, for co-extrusion, it is necessary to use a third (intermediate) polymer for the bonding of non-sticking polymers, which significantly complicates the process. An important criterion for the choice of polymers for multilayer plastic is their rheological properties. The polymers must have the same or slightly different viscosity. This limits the pair of polymers that can be used to make a multi-layer plastic. The purpose of the invention is to increase the strength of multilayer plastic and simplify the process. The goal is achieved by the fact that according to the method of producing multilayer plastic by extrusion of melts of amorphous and jorph-crystalline polymers, cooling and orientation at the same temperature, a mixture of melts of these polymers is used, each containing 1090 wt.%, Cooled in the temperature range from temperatures below the melting point of the amorphous-crystalline polymer to the glass transition temperature of the amorphous polymer, and after orientation they are additionally stacked in the temperature range from orientation ry to the melting temperature of semicrystalline polymer. In the second variant, the goal is achieved in that according to the method of producing multilayer plastic, extruding the thermoplastic polymers of the two thermoplastic polymers using a cooling and orientation at the same temperature uses a mixture of melts of amorphous-crystalline polymers with different melting points for each 10-90 wt.%, Cooling it in the temperature range from the melting temperature of the low-voltage polymer to a temperature 40 ° C below it, and after orientation it is further packaged in the temperature range from Aturi fusible low melting polymer to a temperature below the melting point 10c podimera high melting. The number of layers in the multilayer plastic obtained according to the proposed method is equal to the number of layers in the package and Vio can vary in a small interval (from 3-5 to 250-300). As K-components for the preparation of multilayer plastic, amorphous-crystalline polymers can be used, for example polyolefins, such as polyethylene (PE), polypropylene SPP) i various polyamides, for example polyamide 6, polyamide 12, polyamide 6.6; polyoxyethylene (POE), polyoxymethylene (polyformaldehyde PF) -, polyesters, for example polyethylene terephthalate (CETP); polycarbonates (PC and predominantly amorphous polymers, such as polystyrene (PS), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC). The method is carried out as follows. Plane preparation of a mixture of polymers, for example, PP and PS, obtained by melt displacement and extrusion through The slot head on a single-screw or twin-screw extruder is cooled to the orientation temperature and oriented by rolling on a roll mill or calender with a single-axis or biaxial stretching at a temperature between the PS glass transition temperature and melting PP, then the strip obtained after rolling is palletized (the number of layers is equal to five) and the plastic is molded by heating at a temperature between the rolling temperature and the melting point of PP.In addition, it is possible to simultaneously form a multilayer plastic and an article made of it. , production of packaging by winding on a cylindrical billet after the package has been programmed, it is possible to obtain a multilayer plastic in the form of a pipe. Section 1. Example 1. A flat billet obtained by extrusion of a mixture of PP and PS of a composition of 90:10 wt.% is oriented by rolling on rollers at a temperature (PS temperature of 100 ° C, PP melting point of 165 ° C), obtained by rolling tape the number of layers is 5) and is formed by heating at a temperature of 150 ° C. The resulting plastic has a strength: 26 kg / mm. Examples 2-32 are similar to Example 1. The conditions for the preparation of a multi-walled plastic and its composition are listed in the table. The data in examples 33-36 obtained by the method prototype. Thus, the invention makes it possible to produce plastic of any desired thickness with a tensile strength of up to 25-30 kg / mm, which is 1.5-2 times higher than that of the prototype. In addition, according to the proposed method, it is possible to obtain a multilayer plastic consisting of practically any necessary number of dissimilar layers, the number of layers being determined by the required final thickness of laminated plastic and the thickness of packaged tapes. . The invention provides a significant simplification of the equipment used: the molding of a multilayer plastic from a mixture of polymers makes it possible to limit the use of a single extruder to obtain a laminate of at least two thermoplastic polymers, and it is advisable to cool the mixture and orientation on a single unit, for example, a multi-roll calander.

The composition of the mixture according to the method

eight

Table continuation

PO / PE

132 160 92 (20:80)

PO / PE (10:90)

132 160 120

PA-12 / PE (10:90)

132 162 92

PA-12 / PE (30:70)

132 162 100 152

PA-12 / PE (50:50)

132 162 132 140 23PA-12 / PE (90:10) 132 162 120 24PA-6 / PET (10:90) 230 250 190 25PA-6 / PET (20:80) 230 250 200 26IIA-6 / PET (50 : 50) 230 250 230 27PA-6 / PET (80:20) 230 250 210 28PA-6 / PET 90:10) 230 250 210 2911A-12 / P1F1A (90:10) 95 162 95 30PA-12 / PMMV ( 50:50) 95 162 151 31PA-12 / PMMA (30:70) 95 162 140 32PA-12 / PMMA (10:90) 95 162 110

Prototype

145 10 18.7

132 10, 17.4

14.2

140

Biaxial stretching

15.8 Same

18.6

Biaxial stretching 132 18.9 The same 235 15 38.4 Rollers 230 15 36.2 240 15 31.0 235 15 30.8 235 15 29.3 26.9 Discharge 130 5

n39639

PI / PS. (20:80)

166

100

PI / PS (0:60}

166

100

nn / fic

(60: AO)

166

100 PP / NA 166 100

10 Continuation of the table

125

5.6

Biaxial orientation

125 7.2

Also

125 9.8 125 11.2

Claims (2)

1. A method for producing multilayer plastic by extruding melts of amorphous and amorphous crystalline polymers, cooling and orienting at the same temperature, characterized in that, in order to increase the strength of the plastic and simplify the process, a mixture of melts of these polymers is used at. contents of each 10-90 wt.%, it is cooled in the temperature range from a temperature of 10 ° C below the melting temperature of the amorphous crystalline polymer to the glass transition temperature of the amorphous polymer, and after orientation it is additionally packaged in the temperature range from the orientation temperature to the melting temperature of the amorphous crystalline polymer. 2. A method for producing multilayer plastic by extruding the melts of two thermoplastic polymers by cooling, cooling and orientation at the same temperature, characterized * in that, in order to increase the strength of the plastic and simplify the process, a mixture of melts of amorphous-crystalline polymers with different melting points with each 10 -90 wt.%, Cool it in the temperature range from the melting point of the low-melting polymer to a temperature 40 ° C below it, and after orientation it is additionally packaged in the temperature range round of low melting polymer melting temperature to \ temperature of 10 ° C below the melting point of the high melting polymer.