DE2148706A1 - Oriented films and methods of making them - Google Patents

Description

PATENT LAWYERS 2H8706 Dipi.-chem. Dr.D.ThoiTisen Dipi-ing. H. Tiedtke
Dipl.-Chem. G. BÜhliflCJ Oipl.-Ing. R. ΚϊηΠΘ MUNICH 15
KAISER-LUDWIG-PLATZ *
TEL 0811/53 0211
53 0212
TELEX: 5/24303 topat Dipl.-Ing. W. We IΠ [θ U ff FRANKFURT (MAIN) 50
FUCHSHOHL 71
TEU 0811/514668

Answer requested to - Please reply to: 8000 Munich 15 Sept. 29, 1971

Imperial Chemical Industries Limited London (Great Britain)

Oriented films and methods of making them

The invention relates to oriented films thermoplastic material and especially films made from a mixture consisting of polyethylene terephthalate and polyethylene 1,2-diphenoxyethane-4,4'-dicarboxylate, or from one Mixed polyesters are made from their monomeric precursors. The invention also relates to a method for producing such films.

It is known that by stretching or drawing polymeric materials to induce orientation of the molecular structure the physical properties of the material

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of the material can be modified. For example, uniaxially oriented films have increased tensile strength in the direction of stretching, but are comparatively weak in the transverse direction. A biaxially oriented film obtained by drawing an extruded or cast film simultaneously or successively in two directions at right angles to one another is generally strong in the direction of orientation, ie in the plane of the film, but weak at right angles thereto . Oriented films are generally dimensionally stabilized by a process known as heat setting.

In the case of polymeric materials of low intrinsic molecular viscosity, i.e. in the case of materials of low molecular weight, the individual polymer chains, which are irregularly entangled with one another, are comparatively short. Hence, v / enn P films made from such materials are oriented by drawing are small, the degree of residual entanglement between the polymer chains and the films are comparative because of the Shorten these chains accordingly weakly in a direction transverse to the direction or plane of the pull. Therefore, polyethylene terephthalate films suffer which normally consist of a polymer with an intrinsic viscosity measured in ortho-chloronhenol 25 ° C, made of no greater than about O, G, among a number of disadvantages. For example, a uniaxially oriented film made of polyethylene terephthalate exhibits an intrinsic viscosity

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Manufactured by etv / a 0.6 is »a remarkable trend towards Unfibrate when splitting along the direction in which the Film was stretched. Such fraying is likely to take place instead of when the film is fixed to give it dimensional stability. Biaxially oriented films made of polyethylene terephthalate of similar viscosity usually suffer from poor resistance to bending and tend to split (delaminate) under impact along the planes, parallel to the tensile plane.

In an attempt to overcome the disadvantages mentioned, it has been proposed to use polymeric materials with higher than normal intrinsic molecular viscosity, i.e. materials with comparatively high molecular weight, to use. However, as the intrinsic viscosity of a polymeric material increases, it increases likewise the cost and complexity of making such a polymer becomes that of extrusion and drawing The device required for the high viscosity polymer is more massive and therefore consumes more energy, and that for extruding the Highly viscous polymers increased degree of processing will likely lead to degradation of the polymer with, for example subsequent discoloration of the product.

Accordingly, the invention provides a method of making an oriented thermoplastic film, which consists in a mixture of polyethylene terephthalate and polyethylene-l, 2-diphenoxyethane-4,4'-dicarboxylate or one

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To form copolyesters of their monomeric precursors, v / obei the mixture or the mixed polyester is 10 to 80% PoIyäthylen-l wt., 2-diphenoxyäthan-4,4'-dicarboxylate or has the monomeric precursor, the mixture or the mixed polyesters in film form to extrude at a temperature of 270 to 320 C, quench the extruded material at a temperature below 80 ° C to obtain a film in substantially amorphous form, to heat the film to a temperature above about OO C, the film in to stretch at least one direction to an extent which is at least twice the original dimension in that direction and to heat set the drawn film at a temperature of 120 to 250 ° C.

Uniaxially or biaxially oriented films made by these processes are found to have improved resistance to breakage in a direction transverse to the direction of orientation, while the need for Use of a high molecular weight polymer is avoided. Although these improved properties both in Both uniaxially and biaxially oriented films, the method of the invention is particularly, albeit not exclusively limited to that - to the making of one uniaxially oriented film can be used, which is valuable for the production of belts or drive belts and tapes etc. is, which has a particularly high strength in one direction,

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combined with adequate resistance to fraying require this in the transverse direction. Although the films of the invention are made from a blend or containing a copolyester 10 to 30% by weight of polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate or its monomeric precursors are prepared, the resistance to fiberization and delamination of the Films considerably lower if the content of polyethylene-1,2-diphenoxyethane-4 , 4 '-clicarboxylate or its monomeric precursor in the blend or copolyester falls below about 15% by weight, while at the upper limit of the range the improvement the properties progressively lower when the content of polyethylene-l, 2-diphenoxyethane-4,4'-dicarboxylate or its monomeric precursor increases above about 65% by weight. It is preferred to use blends or copolyesters which 15 to 65% by weight of polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate or contain its monomeric precursors. Considerably less because of polyethylene terephthalate or its monomeric precursor are expensive to produce than polyethylene-1,2-diphenoxyethane-4,4 '. -dicarboxylate or its monomeric precursor, v / ird particularly preferred to use mixtures or mixed polyesters which contain the minimum amount of the latter, as far as "To unite with the production of films that make the desired Have resistance to fraying and delaminating. It is therefore preferred to use blends or mixed polyesters the 20 to 50% by weight of polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate or contain its monomeric precursors. One

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Mixture or a mixed polyester, egg about 20 wt.% Polyäthylenl, 2-diphenoxyethane-4,4'-dicarboxylate or contains its monomeric precursor, gives films with valuable properties, in particular a resistance to fraying.

The polyester components of the mixture are polyester, which consists essentially of terephthalic acid and ethylene glycol as well derived from 1,2-diphenoxyethane-4,4'-dicarboxylic acid and ethylene glycol are. These polyesters can be produced by a direct esterification reaction between ethylene glycol and the appropriate Acid or by effecting an ester exchange between ethylene glycol and the dialkyl ester of the appropriate acid (e.g. dimethyl terephthalate and dimethyl 1,2-diphenoxyethane-4,4'-dicarboxylate) be formed with subsequent polycondensation. When a mixed polyester is used to make the film fc, it can be obtained by reacting a mixture of the monomers Precursors, i.e. the acids or their dialkyl esters, with ethylene glycol through a direct esterification or ester exchange process be formed with subsequent polycondensation.

If the film is made from a mixture of the specified polyesters is prepared, the mixture of polyethylene terephthalate and polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate be effected in any suitable manner, for example by mechanical mixing of the desired

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Quantities of dry materials in a rotating drum.

It has been found that the two components of the mixture interact to form a copolyester, when they are brought into contact, e.g. in other education extruders. Therefore, the term "Geraisch" is intended to be a direct mixture of the two components, a mixture in which one partial exposure has taken place so that some copolyester along with the remainder of one or both of the components is present and even a copolyester in which a complete action of the two components has taken place has to include.

According to a preferred embodiment of the invention a uniaxially oriented FiIn is produced by a process that consists in moving the fiIn in one direction, preferably the machine direction, to an extent at least twice the original dimension in this direction is. The stretching can be brought about by conveying the amorphous film through a traction system, which suitably comprises slow rolls and fast rolls, between which the film in the desired stretch ratio is pulled.

The amount of stretching to which the films of the invention are subjected depends largely on that in the finished product

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Product desired tensile properties, the tensile strength in the stretching direction increases sharply with the increase in the degree of stretching. Irr general becomes a considerable one Degree of molecular orientation and consequent improvement in tensile properties is not achieved if the film is not at least is stretched twice its original dimension in the stretching direction. Uniaxially oriented films, which made by the process of the invention can be drawn or stretched to any extent with the maintenance of the required physical properties storms into the finished product. Un however one Avoid excessive shredding of the film is usually done according to the invention not expected draw ratios of about 5 or g times the original dimension of the To apply the film. Particularly valuable films are made by pulling the film to between approximately deir. 3.0 and 4.0 fadia of its original Preserved dimension in the stretching direction.

Although heat-setting of the uniaxially oriented films of the invention occurs at temperatures of 120 to 250.degree while the film is held under dimensional tension, it was observed that an increase in the heat setting temperature within the range mentioned, the elongation properties of the products in a direction transverse to the direction of extension, as demonstrated by the data listed in the table below, which the

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Change in a number of properties of films uniaxially drawn to three times the original dimension and shows the heat setting with changes in temperatures. The films were mixtures of polyethylene terephthalate and polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate with the listed composition. The change in the properties of the copolyester film follows a similar trend in relation to the heat setting temperature.

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• I. Urinary fixation Polyethylene * 5 Querdeh Transverse stretching transverse tension at 5% deh Transverse fracture module _! O
■ Η temp 1,2-diphene tion border tion
kg / cm * strength kg / mm I. temperature ° c oxyethane-4 _f 4'- 12th at break kg / cm ² (pound / sq.inch) kg / cm ² (Maschi 00 (1 minute dicarboxylate % (pound / sq. (pound / sq. nenrich long on Gev /. % in the 16 inch) 703 inch) tion) O right mixture (10000) th 22nd 12th 773 703 344 (11000) (10000) (12000) 560 140 0 0 10 773 738 330 (11000) (10500) (11800) 570 140 5 5 72 787 738 (11200) (10500) - 560 140 12th 12th 85 759 700 "■ (10800) (10000) - 580 140 16 16 410 773 (11000) 703 - 550 KJ
O 140 22nd 22nd (10000) co 6th 738 703 900 00 (10500) (10000) (12800) 470 - * 160 0 8th 787 738 344 (11200) (10500) (12000) 470 160 36 773 703 (11000) (10000) - 460 160 30th 733 703 co (10500) (10000) - 570 160 137 724 752 (10300) (10700) - 570 160 5 752 759 752 (10700) (10750) (10700) 570 200 6th 759 816 759 (10750) (11600) (10750) 560 200 6th 816 773 316 (11600) (11000) (11600) 560 200 12th 773 773 773. (11000) (11000) (11000) ' 530 200 62 309 (11500) - 570 200

2U8706

Of the properties listed in the table above, only the transverse elongation is particularly emphasized by the increase the heat setting temperature influenced, and to a FiIn which has improved resistance to fraying, it is clearly desirable to keep the film at the lowest possible temperature. However, the Zv / corner of the Thermal fixation process to stabilize the film dimensionally, that one induces crystallization without affecting the molecular orientation of the film, so that the finished film does not suffer from uncomfortable shrinkage, when heated at temperatures up to that at which the crystallization was carried out. En is therefore desirable to select a VJam fixation temperature which in the finished product the optinalo combination of durability offers against both fraying and shrinkage. The FiIn can expediently be in the temperature range from 180 to 210 C heat-set.

According to a further preferred embodiment of the The invention provides a biaxially oriented film by stretching the extruded film in two mutually perpendicular Directions made in the plane of the film.

The biaxial orientation can be carried out sequentially, e.g. by first inserting the film into the Machine direction stretches by placing it between pairs of

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let through slow and fast-running nip rollers and then the film in a direction transverse to the Iiaschinenriehtung means a tensioner, which stretches a set of clamps contains, which are movable along diverging guides in the plane of the film, the clamps the longitudinal edges of the film and stretch the film to an extent

fc which by the degree of divergence of the tensioner guides is determined. Simultaneous biaxial orientation of the film can be effected by using a spanner in which the longitudinal separation of the clamps is increased as the clamps diverge along the diverging line Guides aes tensioner progress. Alternatively, a at the same time biaxially oriented film can be produced with the aid of a tube or blown process, a thermoplastic Pipe is stretched in the longitudinal direction, inden it between spaced slowly and from each other. to run fast-

™ is passed through the nip rollers and the tube inside pressurized in the area between these nip rollers is to increase the cross-sectional area of the pipe to effect.

3 in the production of a biaxially oriented film the degree to which the film has been stretched in one direction determines, to a certain extent, the degree to which the film is then stretched in a second direction can be stretched, and in general

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it is preferred that the degree of stretching in each direction be about does not exceed 4.5 times the original dimension in any direction. A biaxially oriented film with desirable Properties of tensile strength, resistance to delamination and film thickness are preferred achieved by having the film between 2.5 and 3.5 times its original dimensions in each of the stretches in both mutually perpendicular directions.

According to the invention, various additives, for example fillers, consisting of finely divided, particulate Materials, dyes, pigments, light stabilizers or antistatic agents are incorporated into the films will. Examples of suitable fillers are titanium dioxide, Silicon dioxide, silicates and alumino-silicates. The concentration The additive depends on the type of additive and the purpose for which the film is to be used, but it will be im In the case of pigments or dyes, it is normally preferred that the concentration be no greater than about 10% by weight while inert fillers can normally be used in amounts up to about 20% by weight.

The films of the invention can also be coated on other materials, which may or may not be in film form themselves. For example, they can be on wood, on paper, on metals or on

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other thermoplastics are stacked. Valuable laminates can also be obtained by coating the films of the invention on other thermoplastic materials, which are heat sealable. Examples of such laminates are those with polyethylene and polyvinyl acetate and ethylene-vinyl acetate mix polymers.

The invention also provides a heat set, oriented Film made from a polymer blend consisting of polyethylene terephthalate and polyethylene-1,2-diphenoxyethane-4,4 · dicarboxylate or a mixed polyester from their monomeric precursors, the mixture or mixed polyester 10 to 3O wt.% Polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate or its

contains monomeric precursors, and v / obei the film is oriented in an outlet by stretching in at least one direction is which is at least twice the original dimension in the relevant direction.

A film which is una; cially oriented by stretching 3.0 to 4 times in one direction and is formed from a genic or a mixed polyester containing about 20% by weight of polyethylene-1 _F 2-diphynoxyethane dicarboxylate or its monomeric precursor, has an elongation of at least 50% in the direction transverse to the direction of elongation, where the actual value depends on the temperature of the heat set, as discussed above,

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associated with a tension at 5% elongation of about 703 kg / cm (10,000 psi) in the transverse direction and a modulus of over 500 kg / now in the stretch direction. Such a film is not fraying.

The uniaxially oriented fingers of the invention are valuable for applications that require a product with a particularly high Require strength in one direction combined with adequate strength in the transverse direction. Typical applications are photographic film carriers, magnetic audio tapes, packaging tapes, adhesive tapes, drive belts, belts, insulating tape, Decorative yarn and metallized thread.

The biaxially oriented films of the invention are for Suitable for applications where a product with high flexural strength and repeated handling is required. Typical applications are films for drawing offices, applications, where the increased stiffness of a film facilitates the use of a particularly thin film, packaging film and hand- or machine-sorted index or registration cards for use in data retrieval systems.

If a mixture is used, the polyethylene terephthalate component It is advisable to have a standard intrinsic molar viscosity i.e., generally no greater than 0.7 and usually less than about 0.6 as measured in ortho-chlorophenol at 25 ° C. This refers to the basecoat

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Viscosity of the polyethylene terephthalate in a finished film. That of the respective polymer particle ocer chip before extrusion is etv / as higher and the lowering of the value can, for example, as a result of reject or regenerated polymers, for example Foldings of the finished film occur, which are associated with the starting materials or as a result of extrusion

P rides themselves involved. However, the invention is also applicable to mixtures which contain polyethylene terephthalate of an intrinsic molar viscosity which is considerably above the above value, for example up to about 1.3, in which case a decrease in the amount of polyethylene 1,2-diphenoxyethane-4,4'-dicarboxylate can be carried out in a mixture. The intrinsic viscosity of a polymer is in terms of defining the limit value at infinite dilution of the inherent viscosity of the polymer and is through

^ Measurement of inherent viscosity over a range of con-

centrations and determined by extropolation to a concentration of O. The inherent viscosity of a polymer, which by measuring the viscosity of a dilute solution of the polymer in a solvent and comparing it with that of Viscosity of the solvent alone is determined, is defi-

■ * ^{ned as}

1 . ( I Lö C * ^iog e Vi Lö

solution

Solution/

where C is the concentration in grams per deciliter of polymer in the solvent, | Solution is the viscosity of the dilute polymer solution and \ solvent is the viscosity of the solvent

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is. The viscosities listed in this description are consistently in ortho-chlorophenol as solvent 25 ° C determined.

The invention is illustrated, but not limited, by the following examples.

example 1

Polyethylene terephthalate with an intrinsic molar viscosity (measured in o-chlorophenol at 25 C) of 0.65 was with different amounts of polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate mixed with an intrinsic molar viscosity (measured in o-chlorophenol at 25 C) of 0.74, which corresponds to 22.7 kg batches resulted, containing in each case 0.16 and 22% by weight of the mixture of polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate. Any approach was dried at 150 ° C for about 4 hours, then extruded from a slot die at a temperature of 280 ° C, at 20 ° C ■ Quenched by means of a cooled rotating drum for production an amorphous, flat film layer 0.25 mm thick, stretched longitudinally at 95 C to an extent that is in • "in the table below and at 200 C 1 minute long heat set. The table gives various properties of the resulting films.

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- 18 -

Polyäthylen-1,2-üiphen-Streckoxyäthan-4,4 ^u behaves- dicarboxylate: nis (wt.% In the mixture)

Quer- Querspan- Querfe- module stretching at stigkeit (machine transverse yield strength 5% elongation kg / cn ² direction kg / cn ² kg / cn ² (pcund / nq. Tung) (%) (pomd / sq.ipound / sa . inch) kg / rnm ^ inch) inch)

0 5 752 752 752 570 3.0 (10700) (10700) (10700) 16 12th 773 773 773 5 30 3.0 (11000) (llOOO) (11000) 22nd 62 309 773 570 3.0 (11500) (11000) - 0 6th 717 717 900 720 3.5 (10200) (1Ο2ΟΟ) (12800) 16 12th 710 710 886 680 3.5 (10100) (1O1OO) (12600) 22nd 46 696 696 737 670 3.5 (9900) (9900) (11200) 0 9 724 724 1OO 5 320 4.0 (11300) (1130O) (14300) 16 ■ 10 703 703 372 790 • 1.0 (10000) (1OOOO) (12400) 22nd 32 773 773 840 4.0 (11000) (10000) - 0 9 731 731 963 310 4.5 (1Ο4ΟΟ) (1040O) (13700) 16 10 710 71Ο 907 83O 4.5 (10100) (1O1OO) (12900) 22nd 22nd 703 7O3 316 395 4.5 (10000) (IOOOO) (1160O)

These data demonstrate the improved stretch properties obtained across the direction in which the film was stretched by increasing the content of polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate in the mixtures, the improvement being particularly noticeable at a 22% by weight concentration Polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate. A considerable one Improvement of the modulus can also be seen at higher stretching ratios.

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Example 2

Further approaches to the polymer mixtures can be found in Example 1 was prepared, and each mixture was continuously fed from a slot nozzle at a temperature of 280 ° C into a chilled rotary casting drum held at 20 ° C. The GuRfiIm, which was 0.25 mm thick, was in the forward direction and 3, times between slow and high-speed rollers or bolls drawn at a temperature of about 95 ° C and then 3.1 times at a temperature of 11O ° C in a tensioner. Before winding, the film was subjected to a temperature of 180 ° C. while it was on was prevented from shrinking to cause crystallization. The properties of the resulting, biaxially oriented Films are listed in the table below.

Polyethylene elongation stretching tension 1,2-diphen-

oxyüthan-4,4'-%

dicarboxylate

Wt.% In the

limit kg / cn ²

at D -ä elongation

inch)

mix

(POHd ⁷ Si inch)

Breaking strength module strength kg / mm ² kg / cm ² iaound / sq. inch) ■

108 970 1005 1881 410 Ilmachine 405 direction 412 0 (13300) (14300) (26800) 114 934 IO12 1900 404 444 5 (14000) (1440O) (27000) 95 879 914 1643 12th (12500) (13000) (23400) 103 344 3C5 17O6 IG (12000) (12300) (24300) 110 844 053 1797 22nd (12000) (12200) (25600)

0
5

1012 100 (14400) 1023

72 (15700)

921 (13100) 1134

(16200)

1951 (27800) 2063

(29400)

470 Querrich-475 tion

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90 935 1050 2250 485 ■ Querrich 12th (13300) (15000) (32000) 100 372 921 1944 475 tion 16 (12400) (13100) (27700) 75 351 914 1914 505 22nd (12100) (13000) (27200)

The improvement in the modulus of the film both in the machine and in the transverse direction with increasing modulus is particularly striking Content of polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate.

The residual shrinkage of the biaxially oriented films are measured after the films are heated at 190 "C for 5 minutes had been. The results obtained are shown in the table below.

Polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate; % By weight in the mixture

12th

16

Shrinkage%

5.1 5.5 4.2 5.8

Example 3

A uniaxially oriented copolyester film was made and tested.

The copolyester was derived from terephthalic acid and dimethyl-1,2-diphenoxyethane-4,4'-dicarboxylate and ethylene glycol,

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Various proportions of dimethyl 1,2-diphenoxyethane-4,4'-dicarboxylate were used in the manufacture of the copolyester. There was 0.125% by weight of kaolin (china clay) in the copolyester incorporated during the polymerization.

The copolyester was extruded from a slot die and quenched to a temperature of about 20 ° C. using a cooled rotating drum, resulting in an amorphous, flat film about 0.25 mm thick. The film was then stretched in the longitudinal direction at various stretching ratios listed in the table below and at a temperature of about 95 ° C. Finally, the film at 140 ⁰ C was heat-set for 1 minute while being maintained under tension dimension. The properties listed in the table below were measured.

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Share of

Streck- Grundnio- Dimethyl- Querdeh- Querstreck-Querspan- Querbruch- Modul
Relative Vis-1,2-diphen-

nis kosity oxyethane

of the poly 4,4'-dimeric carboxvlate% by weight

Break kg / cm 5% elongation

% (pound / s.nung

inch) kg / cm2

(pound / sn.inch)

U ^g £?! L

direction

kg / well

I. 3.2: 1 0.65 O 30th 612 - 633 500 CN (3700) 548 (9000) Oil 3.2: 1 0.70 15th 265 570 (7800) 471 590 t (8100) 548 (6700) 3.2: 1 0.67 20th 202 577 (7 SOO) 520 500 ... " (8200) 464 (7400) - 3.2: 1 0.76 20th 271 485 (6600) 464 570 (6900) 726 (6600) 3.2: 1 0.68 30th GO 758 (8900) 654 320 ο (10500) 555 (9,300) to 3.5: 1 0.65 O 132 570 (7900) 492 SOO (3100) 478 (7000) 3.5: 1 0.70 15th 305 520 (G300) 450 830 'S » (7400) 605 (6400) 3.5: 1 0.67 20th 114 605 (8600) 562 660 • »a (8600) 478 (3000) 3.5: 1 0.76 20th 385 435 (6800) 499 870 Often (6900) 628 (7100) 3.5: 1 0.63 30th 96 675 (3900) 492 360 (9600) 605 (7000) 4.0: 1 0.65 O 33 626 (3600) 492 770 (3900) 527 (7000) 4.0: 1 0.70 15th 163 543 (7500) 520 790 (7800) 478 (7400) 4.0: 1 0.67 20th 356 492 (6300) 591 320 (7000) 443 (8400) 4.0: 1 0.76 20th 324 450 (6300) 492 G 50 (G400) (7000) 4.0: 1 0.68 30th

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It can be seen that the presence of a comonomer showed a significant improvement in lateral elongation at break compared to the control films Polyethylene terephthalate gives, the improvement being most outstanding when 20 or 30 wt.% Comonomer is used became. This improvement offers greater resistance to fraying.

Example 4

The procedure of Example 3 was repeated, except that the thermal fixing treatment was carried out at 200 ⁰ C for 1 minute. The results for various copolymer components and draw ratios are shown in the table below.

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Stretch Grundinveriiältlare Viscosity

of the polymer

Content of Dinethyl-1,2-diphenoxyethane-4,4'-dicarboxylate (lev /.%

Querueh- Querstreck-Qucrspan- Querbruch- Modul nung glue limit tion with strength ("laschi η τ-Ί ι / -Οι T'r-r / mi 'ζ s Πηΐι— 2 ncnrich

< _P Ä _q . * ψ *

inch) kg / now

fracture

kg / cm ' ¹ 5% expansion

(pound / so, nung-, inch). kg / en ¹

3.2: 1 0.65 0 _ _ MS 593 580 675 654 (8500) 3.2: 1 0.70 15th 4th (9GOO) (9,300) 703 460 731 703 (10000) 3.2: 1 0.67 20th 5 (10400) (10000) 663 570 661 (9500) 3.2: 1 0.76 20th 4th - (9400) 541 520 492 534 (7700) 3.2: 1 0.63 30th IS (7000) (7600) 900 740 N) I 794 737 (12800) O -ςτ 3.5: 1 0.65 0 6th (11300) (11200) 703 630 to ^Μ 316 759 (11000) 00 ι
«■ 3.5: 1 0.70 15th 5 (11600) (10300) 612 710 577 499 (3700) 'S » 3.5: 1 0.67 20th 4th (3200) (7100) 731 670 -J » 703 724 (10400) -J 3.5: 1 0.76 20th 5 (10000) (10300) 485 570 520 485 (6900) 00 3.5: 1 0.68 30th 117 (7400) (6900) 737 930 710 773 (11200) 4.0: 1 0.65 0 6th (10100j (11000) 703 860 773 668 (10000) 4.0: 1 0.70 15th 6th (11000) (9500) 703 830 654 703 (10000) 4.0: 1 0.67 20th 11 (9300) (10000) 733 730 717 724 (10500) 4.0: 1 0.76 2.0 4th (10200) (10300) 415 670 415 415 (5900) 4.0: 1 0.6 S 30th 141 (5900) (5900)

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From this example it can be seen that the improvement in the transverse elongation at break and then the resistance to it Defibration is most noticeable when 30% by weight comonomer is used. Unless high ureme fixing temperatures namely 200 C, as in this example, are applied, it is generally necessary to use a higher concentration Comonoitierem apply to have adequate resistance to Ensure defibration than would be necessary if a lower heat setting temperature, such as that in the example 3 is applied.

209814/1728

Claims (4)

Claims 1. Heat-set oriented, preferably uniaxially oriented film, characterized in that it consists of a polymeric mixture, containing polyethylene terephthalate and polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate or one Copolyesters from their monomeric precursors, the mixture or the copolyester from 10 to 80% by weight of polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate or contains its monomeric precursor and wherein the film is stretched in at least one direction is oriented to an extent -which is at least twice the original dimension in that direction amounts to. 2. Heat-set oriented film with uniaxial orientation according to claim 1, characterized in that the Polymer mixture or the copolyester about 2O% by weight of polyethylene-1, 2-diphenoxyethane-4,4'-dicarboxylate or its monomers Contains precursors and the film by 3.0 to 4.0 times in is oriented in one direction by stretching and an elongation of at least 50% and a tension at 5% elongation of 703 kg / cm in each case in the direction transverse to the stretching and a module of over 500 kg / mm in the stretching direction to v / eist. 3. Process for producing an oriented, thermoplastic Film according to one of the preceding claims, characterized in that a mixture of Polyäthylonte- 2098U / 1728 rephthalate and polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate or a copolyester from their monomeric precursors,
wherein the mixture or the copolyester 10 to 50 wt.% Polyäthylen- 1, 2-diphenoxyü than- 4, 4'-dicarboxylate or its monomeric precursor contains that the mixture or the copolyester in film form at a temperature of 270 ° to 32O ° C extruded,
the extruded material at a temperature below 30 ° C
quenching to obtain a film in substantially amorphous form, that the film is heated to a temperature above about GO ° C, that the film is stretched in at least one direction in a / lus-wet which is at least twice the original dimension in that direction and that the stretched film is heat-set at a temperature of 120 to 250 ° C. 4. The method according to claim 3, characterized in that there is used as a mixture or copolyester such as 20 wt.% Polyüthylen-1,2-diphenoxyüthan-4,4'-dicarboxylate and / or contain its monomeric precursors. 2098U / 1728 IAD ORfGINAL