DE1053362B - Process for the production of laminatable and heat-sealable films made of high molecular weight polyalkylene terephthalates, especially polyethylene terephthalates - Google Patents

Description

GERMAN

The from the esters of terephthalic acid with dihydric alcohols, especially from terephthalic acid glycol estarn, High polymer available through polycondensation, substances have recently been considerable acquired technical interest, for example also on the. Area of foil production. Man maintains them as high molecular weight polyalkylene terephthalates or, if they are made using ethylene glycol are produced as an esterification component, to be referred to as high molecular weight polyethylene terephthalate.

The films are obtained therefrom in a manner known per se by exiting the molten polycondensate from a slot, and z. B. can cool on smooth surfaces. The Eigenschäften of these films obtained by cooling from the melt, making it very greatly improved that they both are stretched length and width by, for example d.er to 2 to 3 ¹ Make original dimensions, and while maintaining this stretch be heated to a higher temperature, for example 140 to 230 ° C; this temperature treatment is usually referred to as fixation. The films treated in this way have very high strength and are very resistant to organic solvents. These properties make them appear particularly suitable for most uses for which plastic films come into consideration. However, the unusual resistance to organic solvents creates difficulties when it comes to the films, with each other or with other substrates, e.g. B. other foils to connect. In addition, the foils can practically not be welded by heat.

In the case of films made from regenerated cellulose, it is known that a thermoplastic can be used on them Coating produced in order to be able to weld them by the action of heat or connect them to other foils. In the case of the coated films made from high molecular weight polyalkylene terephthalates, the Creation of a firmly adhering coating considerable difficulties.

The present invention aims to create surfaces of the films made of high-molecular-weight films that are tempered by stretching and heating. Polyalkylene terephthalates, especially the. Polycondensation products of terephthalic acid glycol esters, in the sense of that the foils can be welded and glued easily. This should also enable to combine these foils with layers or films of other plastics.

The method according to the invention consists in that a method of production is applied to the tempered polycondensate film
of laminatable and heat-sealable films

from high molecular weight

Polyalkylene terephthalates,

especially polyethylene terephthalates

Applicant:

Kalle & Co. Aktiengesellschaft,
Wiesbaden-Biebrich, Rheinstr. 45

Dr. Otto Herrmann and Dr. Hermann Müller,

Wiesbaden,
have been named as inventors

Applies polyethylene layer in the presence of anchoring agents, which at temperatures between 100 and 230 ° C surprisingly good adhesion of the polyethylene layer on the coated polycondensate film cause.

Anchoring means in the context of the invention are organic isocyanates, provided they are heavier are volatile and can therefore be brought into action at 100 to 230 ° C. The term iso ^ Cyanate for the purposes of the present invention includes the mono-, di- and polyisocyanates, and also their monomeric, dimeric and polymeric forms .. It also includes the so-called blocked isocyanates, among including the reaction of the isocyanates with short-chain tertiary aliphatic alcohols with Ethylenimine and compounds formed with acetamide. These compounds show at temperatures from 100 to 230 ° C there is a more or less strong tendency to re-form isocyanate, and are sufficient hardly volatile. The tri-N, N, N-ethylenine phosphine oxide are also considered anchoring agents in the context of the invention and p-nitroaniline.

The anchoring effect is achieved the better and faster, the higher the temperature which heats the tempered polycondensate film during or after the application of the polyethylene layer will. As has been shown, it is not feasible to go beyond the temperature that is during the production of the coated film in the case of heat setting has been applied. So if you want> for example, the anchoring by using a

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Increase temperature of 210 ° C, so you have to use the painting process. to apply. Another unifying film runs out, which after the entanglement to simplify the work process is fixed in this case at least 210 ° C. Since it is generally still achieved, if the anchoring agent is advantageous, the coating, dissolves with polyethylene in this solution and applies it through the polyethylene layer in one operation with fast, ie at the highest possible temperature. It is therefore advisable to add many of the anchors, the polycondensation agents are already sufficiently soluble in the warm polyethylene solution at the highest possible temperature and do not lose their effectiveness even when standing.
Finally, when applying the polyethylene layer, the polyethylene layer can also be applied to the polycondensate film only in small quantities. For example, on the polygen, a polyethylene film with a percent solution of the anchoring agent, e.g. B. tightly and then apply this loose bond to isocyanate, in a thin layer, the solution heated -140 to 230 ° C, so that the polyethylene film means you remove and raw heating. then apply 15 a, uf the underlying polycondensate film to the polyethylene on one or both sides. melts. Man. In this way, a well-adhering polycondene phosphine oxide is provided with a well-adhering film as anchoring agent.

be adherent, the film after application, the solution It is surprising that by the above

for a short time to a temperature between 100 and 20 processes the high-quality tempered. Slides off.

230 ° C, but by no means above that of the heat ^: high molecular weight. Polyalkylene terephthalates one

fixation of the foils applied. Temperature, for easier processing. Polyethy-

warm before the coating with polyethylene is also poorly soluble, only with very little

follows. With the isocyanates and the masked iso- genes. Ν substances can be combined and also chemically

cyanates, this preheating is usually not inert.

brariht. If the change agent in the solution creates adhesive polyethylene coatings on the

or melt of polyethylene is sufficiently soluble, quality polycondensate films. succeed,

it can also be added to this solution or melt

put. Even with this type of application, only a few examples are given

small amounts of anchoring agent required. 30 · 1. A 25 μ thick tempered poly-

There are several ways of applying the polyethylene terephthalic acid glycol ester film, which was obtained from a corresponding layer on the possibly prepainted polychend thicker backing film, by applying a condensate film. Man. A poly can be applied one after the other in the transverse direction to the ethylene melt from a slot nozzle in a thin threefold and in the longitudinal direction to 2.7 times its layer while still hot on the polycondensate film, and in this state it can be stretched up to the temperature go, preventing shrinkage for 2 minutes to which 205 ° C had heated during the heat setting of the polycondensate film. This remunerated film is applied. Also if you want polyethylene, made from thin sides, with an approximately 2% solution of one of the melt at the highest possible temperature for the action of tertiary. Applying butyl alcohol to the formation of a layer, the product obtained in this way is often pre-coated under the action of methylene heat in order to obtain a lene chloride. Slight heating, good adhesion not sufficient, since usually only the methylene chloride is evaporated. Thin, rapidly cooling layers of polyethylene are obtained that are extremely thin and non-sticky. Prefix ,,
be considered. A subsequent heating of the pre-coated polycondensate bundle to temperatures between 100 and 230 ° C 45 is extruded an approximately 40 μ thick molten film is therefore always recommended to create a layer of polyethylene as much as possible. This is used to achieve well-known adhesion. ter way an extruder with a slot nozzle. The poly

Another way to form the polyethylene, - ethylene layer flows on the tempered. Polycondensate coating is the application of a polyethylene film just before it passes a nip, solution, e.g. B. a 85 to 110 ° C warm solution of 50 from a rubber roller and a 80 ° C erPolyäthylen In trichlorethylene, chlorobenzene, xylene: heated polished metal roller is formed, and ü. Like. "In the case of one-sided coating, it is true that the metal roller covers the polyethylene layer Polyethylene solution is pressed onto the polycondensate film with the aid of a caster. The thus obtained Apply polycondensate film, the solvent composite film is then in a heating channel or on then remove by drying in the heat for 3 minutes on a correspondingly large heating roller and the generally required post-heating is heated to 170 to 180 ° C. You make sure that the Perform at 100 to 230 ° C. The warm polyethylene-polyethylene solution melted at this temperature can be used also in, the known paint layer is exposed.

Devices on both sides of the tempered Polykon. A composite film about 65 μ thick is obtained, apply the densat film and carry out the further treatment such as 60, which is heat-sealable on one side and stated above. The application at glued seams, which are extremely strong, the Poilyäthylenschicht can, as described above. The permeability of this composite film against. Luftben, be made to see if the anchoring moisture is very low. Also, their permeability is now in a very thin layer on the speed against. Gases and flavors is unusual polycondensate has applied, or whether one- 65 low and practically negligible. The film there as a component of the polyethylene melt or "-", is therefore very "good for packaging purposes. solution applies. When it comes to the ^r The product of action of tertiary butyl alcohol polycondensate film with very thin. Coating of hol on toluene diisocyanate was produced in such a way that polyethylene, for example 3 to 30 μ thick, was coated with 40 g of tertiary butyl alcohol at about 100 ° C; it is preferable to add the polyethylene solution to 70 45 g of toluene diisocyanate, the mixture

3 hours, held at 100 ° C, another 45 g of tolylene diisocyanate added and the aforementioned temperature was maintained for a further 4 hours. The one after cooling down The crystal slurry formed from the reaction mixture was washed out with petroleum ether and dissolved in methylene chloride solved.

Thickness forms. The tempered polyterephthalic acid glycol ester film coated in this way is then first ^{dried at HO 0} C in the drying tunnel, towards the end

2. A 25 μ thick tempered polyterephthalic acid glycol ester film, as has been described in Example 1, becomes thin with a solution at 30 ° C coated with 2% tolylene diisocyanate in methylene chloride. This prefix can also be used instead a 2% solution of the urea compound which is formed from 1 mole of phenyl isocyanate and 1 mole of ethyleneimine. The slide passes through first a short distance at a temperature of 60 ° C, during which the solvent evaporates completely, and then a drying tunnel on an endless metal belt. Before entering the drying tunnel the slide from one. Caster with a 80 ° C 15% solution of polyethylene in a mixture watered from chlorobenzene and trichlorethylene (1: 3). The caster is set so that a uniformly thick polyethylene layer of 25 μ is formed when it dries Thickness forms. The coated polyterephthalic acid glycol ester film is then first dried in the drying tunnel at 110 ° C, towards the end the temperature rises to 170 ° C.

A composite film is obtained with the same good properties as in Example 1, those for air humidity is a little more permeable.

Is used in this example. Place the solution with 15% polyethylene a similar one with 12% polyethylene and 3% polyisobutylene, -so · obtained if otherwise the same working conditions are observed, a composite film whose heat-sealable one is used . Surface still, easier with paper and the like Documents can be glued by heat and pressure.

3. It is based on a tempered polycondensate film, which is 12 μ thick, but was otherwise remunerated in the same way as in. Example 1 is described .. The film is passed through a 8O ⁰ C warm solution, which by dissolving 6 parts of polyethylene and 0.12 parts of the compound

O O

: n-c-NH- (CH ₂ ) _e -NH-c-n;

CH,

CH,

50

has been obtained in 94 parts of chlorobenzene. The film leaves this solution in a vertical direction up at low speed, leaving only thin, even layers of polyethylene on both. Sides of the film are left behind. The coated film is then dried for 2 to 3 minutes at 160 ° C. she then has about 5 μ thick polyethylene coatings on both sides, which adhere so firmly that the tempered Polycondensate film provides firm connections when heat-sealed. The slide is on both sides heat sealable. It can therefore be glued to all sorts of packaging containers and also has increased interest as electrical insulation film.

4. A 25 μ thick tempered polyterephthalic acid glycol ester film, which was tempered in the same way as described in Example 1, is coated on one side with an 80 ^(O C solution, which is obtained by dissolving 4 parts by weight of low-pressure polyethylene and 0.15 parts by weight of a polyisocyanate produced by reacting 2,4-tolylene diisocyanate and hexanetriol, such as is commercially available under the trademarked name “Desmodur TH”, in 96 parts of chlorobenzene Minutes at 160 ° C. After drying, it has an approximately 5 μm thick coating of low-pressure polyethylene on one side, which adheres very firmly the apparatus described in Example 1 is used.

Claims (3)

Patent claims: 1. Process for the production of laminatable and heat-sealable films from high molecular weight Polyalkylene terephthalates, especially polyethylene terephthalates, characterized in that one stretched in the longitudinal and transverse directions to at least the double of their original dimensions and polycondensate films fixed at temperatures from 140 to 230 ° C in the presence of hardly volatile organic. Isocyanates, isocyanates restoring compounds, tri-Ν, Ν, Ν-äthylenimiinophasphkiO'xyd or p-nitroaniline as an anchoring agent at elevated temperatures between 100 and 230 ° C, but below the fixing temperature of the polycondensate film Provides temperatures with a layer consisting entirely or predominantly of polyethylene. 2. The method according to claim 1, characterized in that the coated polycondensate film even after the polyethylene layer has been applied to the fixing temperature Exceeding temperatures heated. 3. The method according to claim 1 and 2, characterized in that the coated polycondensate film before coating with polyethylene with a solution of poorly volatile, organic Isocyanates, isocyanate-restoring compounds, Trr- Ν, Ν, Ν - äthyleniminophosphinoxyd or treated p-nitroaniline and increased the fixing temperature of the polycondensate film is not exposed to excessive temperatures. Considered publications:
German Patent Nos. 747 627, 818 576, 931216; Swedish patent specification No. 128 424 (Chem, Zentralblatt, 1951, II, p. 1227). © 80J 770/307 3.59