DE2141639A1 - Process for the production of laminates - Google Patents

Description

"Process for the production of laminates ¹¹

The invention relates to a method for the integral, mechanically non-releasable connection of non-polar polymers Substances, such as especially polyolefins, with macromolecular, more or less polar substances, such as polyamides.

Objects made of non-polar plastics, such as polyethylene and polypropylene, for example films, foils, vessels, boats and floats are known. Hollow and solid objects made of polar plastics, especially nylon also known and in trade. Under combination of plastic materials to laminates (laminates) were films, foils and other flat structures have also been produced, e.g. packaging materials made of polyethylene foils with top layers made of polyvinyl chloride. Hollow bodies are also known, the walls of which are made of polyethylene layers with different

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different properties or made of solid polyethylene layers consist, between which a foam layer made of polyethylene is arranged. There were already top layers Made of polyester applied to foamed polyethylene layers, the latter on a solid polyethylene layer were arranged.

In general, the adhesion is between polar and non-polar Plastics quite unsatisfactory and often very bad, even when using an adhesive; usually leave the layers or the conductive layer can be easily separated from one another comes off easily from one of the two surfaces.

In practice, however, combinations of polar and non-polar plastics offer many advantages. Polyethylene does have one broad spectrum of chemical resistance, but for some purposes its stiffness is insufficient, e.g. for Larger containers or vessels with a volume of 5 t> 10 m or more and relatively large wall thicknesses are necessary for components. Polyamides are also at higher temperatures (150 ° G) stiffer and also resistant to some liquids, but not e.g. against strong acids and alkalis, while the resistance of polyethylene is sufficient in such cases. A laminar or layered structure in which the polyethylene is practically inseparable from the polyamide, offers some advantages. When it comes to excluding water and steam, polyethylene is appropriate. Other liquids such as aromatics, gasoline, organic solvents, etc. are preferably in contact with a Stored polyamide wall. An outer wall made of polyethylene can be advantageous to improve the impact strength and for protection against moisture and other atmospheric influences.

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The invention offers a solution to the problem of a practically inseparable connection between the surfaces of macromolecular polar and non-polar substances. It has been found that surfaces of objects such as films or foils, vessels, plates or even film and coating layers made of polyolefins can be bound practically inseparably to surfaces of polar substances, in particular polyamides (nylon), by means of an intermediate layer, the intermediate layer predominantly or entirely of slightly halogenated polyolefins with a halogen content of up to a maximum of 5 % ■> preferably 2 to 4%. Usually the adhesion is such that delamination becomes impossible.

Polyolefins can be used to form the layer structures of high, medium or low density and polyethylene Use polypropylene, optionally copolymerized with an ethylene component.

For example, polyvinyl chlorides, polystyrene, polyacrylates, polyesters and many others can be used as the polar component will.

The intermediate layer between these materials can consist of halogenated, preferably chlorinated, polyethylene or -a & e polypropylene. Sometimes it is advantageous to arrange a foam layer made of halogenated polyolefins as the intermediate layer, which can be produced in a manner known per se by mixing such polyolefins with a chemical compound that decomposes or vaporizes with generation of gas, so that a foam is formed when the halogenated particles melt together will.

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The application temperature of the halogenated polyolefins is usually below the melting point of the polyamide. and above the softening point of the halogenated polyolefin. For polyethylene and polycaprolactam "this means a temperature range of 110 to 220 ° 0, preferably 120 to 180 ° G.

The halogen, especially chlorine, content of the intermediate layer should be 0.2 to 5? preferably 2 to 4 ^c / o of the weight of the polyolefin, it being normally not expedient to go higher than 4) o. Under 1> there is already a favorable effect, but delamination cannot be ruled out. Adhesion is by no means sufficient below 0.2 yo.

It is known to produce thin tubes, the walls of which are made of laminated foils such as polyethylene and polyamide foils, the adhesion between these foils being improved by treatment with a dipole-generating gas such as fluorine and GhIOr _1, but also oxygen, ozone, boron trifluoride and many others will. The treatment takes place immediately after the films have left the extrusion die and before they are pressed together. This gas treatment of the surface is fundamentally different from the process according to the invention, in which the halogenated polyolefin is produced separately and used in this form. In the manufacture of larger objects, especially containers, the surface treatment becomes very difficult; In one experiment, for example, the chlorine was so irregularly distributed over the surface of the polyamide that the adhesion between the surfaces was practically inadequate, since the layers did not adhere to one another at all in many places.

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There are also systems for the coating of surfaces with polar chlorinated polyethylenes with more than 5 '/ ^ chlorine content, preferably 20 to 40' / o chlorine, become known. The layer is applied by heating the object in question to at least 200 0 and then introducing it into a fluidized bed made of polyethylene chloride. This process has to be repeated several times until a satisfactory layer thickness is achieved. after 6 repetitions, for example, a layer thickness of only 0.4 mm was achieved. Treatment is complicated and limited to heat-resistant products.

Vulcanizable mixtures of chlorinated polyethylene with 15 to 50 % chlorine, a polyfunctional component with unsaturated end groups and an initiator, e.g. an organic peroxide, have already been proposed for lashing purposes and mixtures of polyolefins and / or chlorinated polyolefins with an adhesive are used for gluing seamless tubes known from polyamide with a protective cover made of fabric.

However, none of these prior publications indicated that ±;> polyolefins with less than 5> halogen would be suitable for the insoluble connection of polar and non-polar surfaces. Polyethylenes with a higher chlorine content have properties that differ more and more from those of polyethylenes. The weakly halogenated polyolefins with less than 5 "/ ■> -, preferably not more than 2 halogen, on the other hand, are much more similar to the starting polyolefins.

Given the low chlorine content, it is understandable since in certain mills the polyethylene is the basic ; jchicnb can be replaced by chlorinated polyethylene, so

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two layers suffice for the intended purpose, i.e. that the wall structure consists only of a weakly chlorinated polyethylene and a polyamide layer.

The weakly chlorinated polyethylenes according to the invention can be used in a wide variety of known i'ormsystems for thermoplastics are used. For example, you can peel off supply rolls for the production of laminated eolias Lay individual films made of polyethylene, weakly chlorinated polyethylene and polycaprolactam on top of one another and the Combination lead to the formation of a laminate sheet between a pair of rollers, at least one of which is heated. a cook It is more appropriate to first apply the chlorinated polyethylene to the heated polycaprolactam and only then the To connect the polyethylene surface with the surface of the chlorinated polyethylene.

Another implementation method uses a running belt made of, for example, interconnected rectangular Bowls with flat or relief-like walls can exist; the bowls pass one after the other the following facilities:

a) A feeding device where a certain amount of oraprolactam with catalyst and promoter is poured into the horizontal bowl, preferably over it maintaining a blanket of inert gas;

b) a heating device to bring the olaprolactam to the polymerization temperature (150 to ^ UU ⁰ O); It is advisable to keep the gas blanket in place during the polymerization.

The end product from this phase is made up of a solid plate

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Polycapro lac tain with a temperature of more than 13 ^: 0 ° C, preferably about 180 ⁰ C ^

c) a distribution device with which preferably powdery, weakly halogenated polyethylene is distributed evenly over the surface of the plate;

&) if necessary, a heated roller to spread the layer of halogenated polyethylene smoothly and evenly:

e) a distributor to distribute powdered polyethylene evenly over the chloropolyethylene surface;

£) if necessary a heating device to bring the temperature to the desired level;

UJ optionally a heated roller to the Polyäthylei smooth and spread it evenly:

h / a cooling device, around a fluid medium, e.g. water mist or cold air, to pass over the molding, if necessary, simultaneously from above and below;

1) a removal device for the fully formed panels, which can be used, for example, in the construction industry for insulating or decorative corners.

Of course, you can add pigments, dyes, insert sheets to the base materials or the molded parts and / or add fillers.

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In the above process, but also in other types of implementation, the massive layer of chlorinated polyolefin can be replaced by a porous (foamed) layer of chlorinated polyolefin by adding a propellant to the chlorinated polyethylene powder so that one immediately adheres to the polyamide - or polyethylene surface bonded foam layer receives. Suitable blowing agents are suitable any known blowing agent decomposes above about 130 ⁰ G, for example, certain types under the name "Porofor" (protected trade name of Bayer AG, Leverkusen) are available, such as "Porofor D-33" (a diphenyl sulfone ^-3,3! -Disulfohydrazide). When foaming, it is recommended to use a linking agent such as dicumyl peroxide or "Perkadox 14" (registered trademark of the "Koninklijke Industriele Maatschappij Woury & Van der Lande UV", Deventer, Holland), a linking agent based on 1,3-bis- ( tert-butylperoxyisopropyl) benzene to be used. Apart from the weight advantage, due to its elastic character, the foam has the advantage of not compensating for too great differences in the thermal expansion coefficients of the layers to be connected and thus preventing the occurrence of unacceptable stresses in the laminate structure.

It should be mentioned in particular that the weakly halogenated Layer can also be used to expand or change the chemical resistance of the polyamides. Rigid polyamide containers can be used in this way to store or transport e.g. mineral acids and alkalis.

A preferred method for shaping Hollow bodies, containers, bottles, boats, reservoirs, motor vehicle bodies or their parts and the like is the sintering process, being solid thermoplastic powder in the ii'orm

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be abandoned, which is at atmospheric pressure as a result the heat supplied through the wall of the wall gradually dissipates from the Attach the wall and form a layer that covers the wall flow together. In modern devices the form rotates around two axes, preferably perpendicular to one another, The rotation around one or both axes can also be a rocking movement. This rocking motion can be pretty about you small angle, e.g. 30 ° above and below the horizon, but also over larger angles up to 90 ° above and below the horizontal surface, i.e. as a half notation in both Calibrations are carried out.

Furthermore, a static sintering process is known in which the ϊοπα completely filled and after settling a (part of the Powder on the wall is emptied again, followed mostly by heating to create a smooth inner surface is still going on. A rotation around an axis (mono-rotation) can be used to shape cylindrical products. be performed. The heating through the Eormwand can with hot air or molten salt and the like. Or else with double-walled JOrms with hot oil. In particular With rocking systems you can also heat with gas flames from burners, which are probably the rocking movement, but not follow the rotational movement around an axis perpendicular to the swing axis. You can also heat electrically, either by resistance ™ or by induction or dielectric heating. There is also infrared radiation often an advantage.

In the present process it is preferred, but not necessary to start with the anionic polymerization of caprolactam at 130 to 200 ⁰ G by a liquid in the ii'orm, optionally up to 10 G or more in

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the polymerization temperature heated mixture of caprolactam, catalyst and Prolnotor introduces and the mold moves so that the liquid is evenly distributed over the mold wall, whereupon the temperature on the brings desired value. A good distribution can be achieved, for example, by double or mono rotation, if necessary with a rocking motion combined, depending on the one in question Shape, can be obtained. The polymerization proceeds very quickly with the formation of a solid polymer layer on the Molded wall.

Here you bring in the chlorinated polyethylene, whereby it it is not necessary to first cool the mold. It is advisable to move the mold during or immediately after the addition to continue without further heating, because the temperature is usually high enough to use the halogenated polyethylene Bring stratification. After a chlorinated polyethylene layer has formed over the polycaprolactam surface the polyethylene powder is added, preferably again without prior cooling. This creates an inner layer made of polyethylene.

The product is removed from the mold after it has cooled down by itself or with cooling. The laminate walls are generally not delaminatable by mechanical means.

About the notched impact strength, especially at low temperatures To increase, one can also in advance the chlorinated polyethylene thoroughly and homogeneously with a propellant mix so that a foam layer is formed when heated.

Of course, in this case you can also choose the one or the other

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Add known additives to basic materials, x ^ ie pigments, dyes, Fillers, stabilizers, lubricants, etc.

The chlorination of polyethylene can be done in a simple manner be effected by treating polyethylene powder at normal or elevated temperature with chlorine to the desired chlorine content has been reached. In order to accelerate the reaction, apart from an elevated temperature, e.g. 75 ° C, also use increased pressure.

Other known chlorination processes can also be used, for example chlorination of a dispersion of the polyethylene in an organic liquid, such as carbon tetrachloride, by introducing chlorine gas at 70 ° or higher. The polyethylene can also be in solution, especially if you are at temperatures above 100 C and below Pressure works. The chlorination can also be carried out with sulfuryl chloride.

The thickness of the individual layers can be chosen very differently. The polyethylene and polyamide layers can be less than 1 mm to several cm thick. The same applies to the chlorinated layer, whose thickness also applies to the Can be on the order of a few hundredths of a mm or even less.

The very good adhesion of the weakly chlorinated polyethylenes or polypropylenes is particularly surprising Polycaprolactam, of which it should be noted that polyethylene is subjected to surface oxidation in a known manner shows no adhesion to the caprolactam polymer at all. Very good adhesion came first with anionic

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polymerized caprolactam. It is possible that here the -G-IT- group of the caprolactam polymer with the chlorine below I! I.

OH

HCl formation reacts, ie a chemical bond is formed. This appears likely to the extent that the HCl is taken up and bound in the alkaline medium of the lactam polymer. Although anionically polymerized polyamide balanced with water also showed excellent adhesion with halogenated polyolefin, the results were consistently unsatisfactory and it is therefore recommended to use both the anionically and hydrolytically polymerized polyamide as a dry, anhydrous product. Numerous attempts were made, the polymerization of caprolactam being ^{carried out at 160 °} C. and 50 ~ / o NaH in oil as catalyst (0.25 %) and phenyl isocyanate (1 ^c / o) being present as promoter. The catalyst was admixed with the molten caprolactam at 120 ° C., after which the promoter was added at the same temperature. The results are listed in the following table, the abbreviations have the following meanings:

PCL = polycaprolactam

LDPECl = chlorinated higher density polyethylene

(Cl = 2 to 3)

HDPECl = chlorinated low density polyethylene

(Cl = 2 to 3 Grew .- ^)

LDPE = high density polyethylene (low pressure

process)

HDPE = low density polyethylene (high pressure

process)

PPCl = chlorinated polypropylene

PP = polypropylene

(Including the letter S means that the layer is foamed became.)

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Table of laminated polyolefin and polycaprolactam layers

lower layer intermediate layer upper- enamel-. !Result

Layer index "the

(DIN 53735E) lamination

Polyolefin tion

PCL LDPEOl LDPE 5 POLE HDPEOl HDPE 20th PCL HDEEGl LDPE IN- PCL LDPEOl HDPE CVI PCL PPOl PP - PCL PPCl HDPE 2 PCL PPOl LDPE 7th PCL HDPEOl PCL - PCL LDPECl POLE PCL PPCl PCL - LDPE LDPECl POLE IN- HDPE HDPEOl POLE 2 LDPE HDPECl PCL 5 HDPE LDPECl PCL 20th PP PPOl PCL - HDPE PPCl PCL 2 LDPE PPCl PCL 7th PCL HDPESCl POLE - PCL LDPESCl POLE PCL PPSCl PCL - POLE LDPESCl HDPE 7th LDPE HDPESOl PCL

= excellent
= good to very good

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In no case did sieve let the layers separate.

The invention is based on the following embodiment "examples explained.

Example 1 Manufacture of a container for gasoline

In this case a sintering machine was used, where "at the mold rotated at 30 rpm and 6 full open and Companions rocked. Swing angle 85 ° up and down. The heating was done with gas flames from burners, which were in the swing frame ".

The volume of the container was 60 1. The mold was previously flushed through with inert gas.

First, 3 kg of caprolactam with 0.25 % catalyst (NaH) and 1% accelerator (phenyl isocyanate) were brought into the mold heated to 160 °. The polymerization proceeded very quickly with the formation of a solid layer about 4 mm thick on the mold wall. The mold was continuously connected to the atmosphere through a funnel.

1.25 kg of chlorinated polyethylene with 2.2% chlorine were poured into the fitting. The powder formed a closed one even layer on the POL surface, whereupon without Interrupting 1.25 kg of HDPE was added, which forms a uniform, well-adhering layer on the HDPECl surface formed.

After cooling with water mist, the product was removed from the mold and " further cooled with water. In the cross-section were the three

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Layers clearly visible. A longitudinal section in which two half cylinder surfaces were obtained could be made without deformation be loaded with 100 kg on the convex side. It was impossible to close the layers by mechanical means separate.

Example 2

As described above, the sheets of paper churned out became flat made, xirelche from a PCL layer, one foamed on top HDPECl layer (foam compound "Porofor D-33") and a dense PCL layer sintered thereon. In this way they became highly water repellent and receiving insulating components.

Example 3

Hylon-11 (known under the protected trade name "Rilsan" the French company "Organico", Paris) in granulate form, was sintered to a flat round disc (diameter 20 cm, height 2 cm). Sintering temperature 200 ° C.

At 200 ⁰ C 50 g PECl were added at 3 7 "Cl with further heating. The adhesion was very good. Separation strength> 35 kg / cm.

Example 4-

Instead of Kylon-11 from example t> , hydrolytically polymerized Hylon-6 (polycaprolactam) was used. The solid disk of the same dimensions as in Example 3 was heated to 160 ° C., after which PECl with 3 % chlorine was added. The adhesion was very poor.

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The experiment was repeated after using the same nylon-6 was heated to 160 ° C for 2 hours. The adhesion was better, but a third, two-hour heating to 160 ° C ■ necessary to achieve a really flawless adhesion.

Example £

716 g of caprolactam with 0.25% NaH and 1 % phenyl isocyanate were polymerized at 170 ⁰ O in an oil bath. After cooling, an extremely thin white surface layer could be seen on the upper surface that was in contact with the air. PEG1 did not unite with this surface. After the disk had been inverted, perfect adhesion with PECl (50 g; Cl 3? ») Was achieved after sintering at 170 ° G.

A PE layer was prepared by adding 116 g of PE-powder (d = 2 mm) and heating to 170 ⁰ C on the sintered PEGL surface area.

When the three-layer disk was examined, it was found that a force of 30 kg / cm at 20 ° C. perpendicular to the surface did not cause delamination, but that the PE began to expand. The combination was subjected to a cold test, the test piece was kept for 24 hours at -20 ° G and then for 2 hours at +80 ⁰ C and this cycle was repeated ten times. There was no sign of any delamination.

Example 1 6

A sintering apparatus and a mold according to Example 1 were used. First there was an amount of 1.6 kg of HDPE in the on

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A mold heated to 160 ° C. was introduced, whereupon, as soon as a layer had formed, 0.8 kg of HDPECI (with 2.2% chlorine) were added without interruption. An approximately 3 mm thick layer was attached to the mold wall. After the mold had been flushed with inert gas, 2 kg of caprolactam with 0.25 % catalyst (NaH) and 1 % accelerator (phenyl isocyanate) were polymerized in the mold at 160 ° C., with an approximately 2 mm thick layer of PCL on the first formed Layer formed. The adhesion between the layers forming the wall of the object obtained after cooling was mechanically comparable to that of the laminated wall of the product according to Example 1.

Claims

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Claims (7)

Claims 1. Process for the production of laminates (Laminates), in which a layer of a non-polar with a layer of a polar thermoplastic Resin is firmly connected, characterized in that between each two Surfaces of the resin layers to be connected an intermediate layer of polyolefin with 0.2 to 5 wt .-% Halogen, in particular chlorine, which is anchored in both surfaces, forms. 2. The method according to claim 1, in particular for the production of laminates, in which the surface a polyamide layer is firmly connected to that of a polyolefin layer, characterized in that the surface of a corresponding shape first with a dry polar or a dry apolar thermoplastic Coated synthetic resin, after which a second layer is applied to the free surface of the synthetic resin in question of weakly halogenated polyolefin with 0.2 to 5 wt .-% halogen and the resulting free area made of halogenated polyolefin coated with the other synthetic resin. 3. Process according to claim 1 or 2, characterized in that the layers are through Sintering the finely divided resins produced, the resins being introduced into the mold one after the other without one die.vorangehende layer on a below the sintering temperature the temperature lying on the next shift cools down. 209816/13 2 0 2U1639 4.. Process according to claim 1, 2 or 3 »characterized in that the polyamide layer formed by placing the monomer in the mold together with a catalyst and a promoter introduces and polymerizes it into a cohesive layer by the supply of heat. 5. The method according to any one of claims 2 to 4, characterized in that the layers one after the other without interruption of the proceedings Pormungsver- t in a mold forming, which is rotatable in a known per se ¥ else to two mutually perpendicular axes. 6. The method according to any one of claims 1 to 5, characterized in that the pulverized halogenated polyolefin for the purpose of forming a foam intermediate layer, which the polar with the apolar resin layer connects, adds a propellant. 7. Modification of the method according to one of the claims 1 to 6, characterized in that f for the purpose of generating a bilaminar structure, the first introduced resin layer covered with a layer of weakly halogenated polyolefin. 867 2098 16/1320