DE2428464A1 - POLYESTER FILMS AND THEIR USE - Google Patents

Description

The invention relates to a polyester laminate film of a novel structure and its use.

In general, polyester films are important as plastic films because of their strength and heat resistance. It has now been found that a new and useful polyester film with several superior Properties not found in common polyester films in addition to the superior properties which are peculiar to polyester films, can be obtained by creating a layer structure of two or three layers made of polyester films in such a way that the two polyester films, which form the outer layer of the layer film, are made of two types of polyesters

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are built up, whose intrinsic viscosities differ from one another differ within a specific area.

The invention provides a stretch-oriented polyester layered film consisting of two or three layers of polyester films, the two polyester film A and polyester film B, which form the two outer layers of the layer film, made of a polyester with a Intrinsic viscosity from 0.35 to 1.0 and the intrinsic viscosity of a polyester that makes up the polyester film B is 0.02 to 0.5 larger than that of one of the polyester film A forming polyester, the layered film being corrugated in the width direction, the polyester film B is arranged inside the corrugation.

The invention is described in detail below.

The layered film of the invention is a layered structure of two or three layers of polyester films and the Both polyester films, which form the two outer layers of the layer film, are made of a polyester with an inherent viscosity (measurement of the molecular weight) of 0.35 to 1.0, preferably 0.4 to 0.9, the difference being the inherent viscosity between the one outer Layer forming polyester and the other outer layer forming polyester 0.02 to 0.5 »preferably 0.3 to 0.2 and particularly preferably 0.04 to 0.1. The layered film of the invention can only consist of the above described two polyester films or optionally a third polyester film between the two polyester films forming the outer layers to form a three-layer polyester layer film be interposed.

After stretching the polyester layered film thus produced (preferably biaxially stretched) and heat setting

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becomes the layered film in the width direction (the direction at right angles to the machining direction) of the layered film selected, wherein the film with the higher inherent viscosity is arranged in the interior of the corrugation, because a difference in shrinkage stress between the die outer layer forming polyester films, which is attributable to the difference in molecular weight. The layer film selected in this way has a very high rigidity compared to a flat layer film free from undulations. Increased stiffness is very desirable for various polyester film applications.

In the present application, the polyester film forming an outer layer is made of a polyester is constructed with a low inherent viscosity, referred to as "polyester film A" and the other outer Layer-forming polyester film, which is built up from a polyester with a higher inherent viscosity referred to as "polyester film B".

The polyester film that may exist between the polyester films A and B is referred to as "polyester film C".

The polyester constituting the polyester films A, B and C in the polyester layered film of the invention is a crystalline aromatic polyester that is a homopolyester such as polyethylene terephthalate, Polyethylene-2,6-naphthalate, polytetramethylene terephthalate, Polytetramethylene-2,6-naphthalate or polycarbonate; a copolyester, which consists of at least 85 Möl% units, the are derived from a monomer making up the homopolyester and not more than 15 mol% of units that are derived from another ester-forming monomer, is built up; a mixture of these polyesters or a poly

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merengend.sch, that of at least 90% by weight of such Homopolyester or copolyester and not more than 10% by weight of another polymer, which the excellent properties of the polyester practically not influenced, includes. Examples of the other polymer, that used to make the polycating mixture are polyamides, such as polycaprolactam or polyhexamethylene adipamide, polyolefins such as polyethylene, polypropylene or polybutene-1 and vinyl polymers such as polystyrene.

The polyesters constituting the polyester films A, B and C can be the same or different.

In order to impart good lubricity to the polyester layered film of the invention, a finely divided powder of an inert compound may be mixed and dispersed in the film. The fine particles of the inert compound can be incorporated into either or both of the polyester films A and B. Examples of suitable inert compounds are MgO, ZnO, MgCO 1, CaCO 4, CaSO 4, BaSO 4, Al ₂ O ₅ , SiO ₂ , TiO ₂ , terephthalates of Ca, Ba, Zn or Mn, carbon black, graphite and pigments. The shape of the particles of the inert compound can be rectangular or spherical. The particle diameter of the particles is not particularly limited. Usually, however, it is preferred that the arithmetic mean of the diameter of a particle be in the direction of its maximum diameter and that in the direction of its minimum diameter. is about 0.1 to 10 microns.

The finely divided inert compound can be used before or during the polymerization reaction to form the Polyesters are added. It can also be pelletized with the polyester in an extruder after polymerization be mixed. Or it is also possible

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adding the compound to a sheet form during melt extrusion of the polyester and placing it in the extruder to disperse. The amount of the inert compound to be added differs depending on the properties of the film and is not particularly limited. Usually the amount is 0.01 to 40% by weight, preferably 0.05 to 5% by weight, particularly preferably 0.1 Ms 2% by weight, based on the weight of the polyester film A or the polyester film B.

When it is desired to color the polyester layered film of the invention, it is preferred to use a three-layered one Layered film using polyester film C containing a dye or pigment, to build. With this operation, the coloring agent becomes stable in the intermediate layer of the polyester film C without Retain leakage or separation due to surface friction. Of course it is also possible to use a coloring Means also to be incorporated into polyester film A or B or both polyester films A and B.

The polyester film G can also be used when it is desired to increase the thickness of the layered film raise.

The layered film of the invention can also contain other additives, such as, for example, customary stabilizers, matting agents or contain antistatic agents. The strength of the polyester layered film of the invention is not particularly limited, but it is usually preferred that the thickness be 1 to 2000 microns, especially 4 to 5000 microns. The ratio of the thickness of the polyester films in the layered film can be varied as desired will. In general, when the polyester layer film has a two-layer structure, it is preferred that the ratio of the thickness of each polyester film A and

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B to the thickness of the entire layered film is adjusted to 5 to 95%. If a three-layer structure containing the polyester film C is desired, the thickness of the polyester film C is subject to change. In particular, when it is desired to increase the thickness of the entire layered film, the thickness of the polyester film C is adjusted so that the thickness of the entire layered film becomes the desired thickness.

Any known conventional layering method can be used to manufacture the polyester layer film of the invention can be applied by the polyester films A and B and optionally also the polyester film C to be laminated. A preferred method is

that
therein, / polyesters which may or may not contain the inert compound are extruded to form polyester films A, B and C to form a layered film, for example, and then the obtained layered film is stretched and thermoset. The stretching of the layered film can be carried out either uniaxially or biaxially, but it is usually preferred to stretch the layered film in two directions successively or simultaneously.

As stated earlier, the polyester layered film of the invention is corrugated and possessed in the width direction because of this, the advantage of a far greater rigidity than the usual polyester films. Further, the polyester layer films have additional advantages of the invention. These additional benefits are more evident, though the inert compound is incorporated in the layered film of the invention.

At normal heat curing temperatures for one Layer base film in which a polyester with low

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Molecular weight, a film of the polyester has a low molecular weight due to the difference in molecular weight a higher degree of crystallization when thermosetting at the same temperature during takes place during the same period. On the other hand, as the degree of crystallization of a polyester film increases, its density is greater and the abrasion resistance of the film is increased. When the inert compound in the polyester film A (lower molecular weight polyester) is dispersed, the degree of crystallization of the polyester film becomes A further increased by the action of the inert compound, because this inert compound acts as a nucleating agent acts, which promotes the crystallization of the polyester. Hence, coupled with the influences of the molecular weight, as mentioned above, the degree of crystallization in the polyester film A is very high and the abrasion resistance of the surface of the polyester film A is markedly increased. Hence, the polyester layered film is of the invention for applications that require a surface area of the polyester layer film to have a high Has abrasion resistance, very useful. It also enables the lower molecular weight polyester has a higher terminal carboxyl group content than the higher molecular weight polyester Film of the lower molecular weight polyester better adhesion to the added inert compound. Thus, the incorporation and dispersion of the inert Compound in the polyester film A also from the standpoint of preventing leakage and separation of the added inert compound advantageous.

In another preferred embodiment of the

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invention, a polyester layer film is produced, whose

F-5 longitudinal value to at least "12.0 kg / mm through appropriate selection of the stretching conditions for the layered film has been set. The phrase "F-5 "Longitudinal Value" means a value obtained by stretching a film sample by 5% at room temperature and a relative humidity of 65% and a draw rate of 100% per minute using of a conventional tensile tester such as an Instron tensile tester, the related to this Time applied to the specimen is measured

and is reported as kg / mm of the cross-sectional area of the sample prior to testing.

If polyethylene-2,6-naphthalate is used as polyester, it is possible and expedient to use the F-5-

Set the longitudinal value to 16.0 kg / mm or more. The polyester layered film of the invention with a

F-5 longitudinal value of at least 12.0 kg / mm (at least 16.0 kg / mm when using polyethylene-2,6-naphthalate can be produced by any desired method. For example, a layered film can be stretched of a reoriented layered film at a ratio of 3 »5 to 6.0, preferably 4.0 to 5 * 0, in the longitudinal direction and at a ratio of 1.5 to 4.0, preferably 2.5 to 3 »5» in the transverse direction, the stretching ratio in the longitudinal direction to at least 0.3i, preferably at least 0.7 and particularly preferably 1.0 higher is set as that in the transverse direction and then

manufacturedx vreraen. send the stretched film is thermoset, / As a result of the stretching of the film, so the stretching ratio is higher in the longitudinal direction than in the transverse direction, the polyester layered film of the invention sufficiently retains

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Maintains strength in the longitudinal direction at and even if the thickness of the layer film is reduced very much he still has sufficient strength. This provides very great advantages in various applications.

Due to the various superior properties, the polyester layer films of the present invention are suitable for Suitable for many applications, for example as ■ packaging films or foils, molded foils, films for outdoor applications, electrically insulating foils and metallizing films. Further, the polyester layered films of the invention are under Use of their high rigidity as base films for adhesive tapes, Measuring tapes and magnetic cards suitable. Or decorative films can also be made from it by applying desired colors can be produced.

Packaging films or sheets, Form films, films for outdoor use, electrical insulating tapes, metallizing films, measuring tapes and adhesive tapes to be mentioned with weather resistance. Measuring tapes and adhesive tapes with superior weather resistance and high Stiffness was previously required. Superior weather resistance can be added to the polyester layered film by using a mixture of polyethylene terephthalate and polyethylene-2,6-naphthalate than at least one of the polyester films A and B, which are the outermost layers of the layer film form, be granted.

The amount of polyethylene 2,6-naphthalate differs depending on the desired properties of the film. Usually, the suitable amount is, for example 0.1 to 100% by weight, preferably 0.5 to 30% by weight, more preferred 1.0 to 10.0% by weight based on the weight of the polyester film A or the polyester film B.

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It is believed that when made from the mixture of polyalkylene terephthalate and polyethylene-2,6-? Iaphthalate The built-up surface is exposed to sunlight, that surface is light of a short wavelength range (high energy) due to the content of polyethylene-2, 6-haphthalate absorbed and thus the deterioration of the film is inhibited. By mixing polyethylene-2,6-napJithalat in one or both of the Polyester films A (lower molecular weight polyester) and B (higher molecular weight polyester) the polyester layered film of the invention has high rigidity and superior weather resistance with no "deterioration superior strength and elongation inherent in polyester.

'' Depending on the combination of inherent viscosity and the amount of polyethylene-2,6-naphthalate added the direction of the corrugation is sometimes reversed to that given above. It is therefore preferred Measuring tapes, adhesive tapes and the like. Manufacture so that the surface exposed to sunlight is located outside.

With a view to imparting weatherability to the layered film of the invention, an ultraviolet absorbent can be used are incorporated into at least one of the polyester films A and B.

Another suitable use of the polyester sheet film the invention resides in a base for photographic films. At first, films were made Nitrocellulose or cellulose diacetate was used as the basis for photographic films, and later came cellulose triacetate films for use. In recent years, polyester films have become these common materials because of

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the various advantages that polyester films have, such as superior transparency and mechanical strength, high heat distortion temperature, chemical resistance and photographic inertness Emulsions. However, when a photographic emulsion which is a hydrophilic polymer, such as gelatine, which contains the main binder, is drawn onto the surface of a polyester film, curl occurs in the photographic film due to significant shrinkage and expansion Changes in humidity. This phenomenon also occurs when using a cellulose film such as a triacetate film, as a base, however, the degree of curling is far larger in this case than in the case the use of a polyester film as a basis. Because the curl of the photographic film is a decrease Because of the efficiency of enlargement and copying, films without curl are desirable. Polyester films have decreased elongation and concentration due to changes in humidity Compared to cellulose films, if, however, excessively after drawing up a photographic emulsion dried or left in low humidity after development, curl will occur, wherein the emulsion-coated surface is disposed inside. It seems difficult to get the corrugation completely to eliminate. Previous attempts to remove the curl or curl include a method in which the thickness of the polyester base film is increased or a method in which an anti-curling agent is applied to the surface is applied, however, these methods have many economic disadvantages.

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When the polyester layered film of the invention is used as Film base is used, and a photographic emulsion is coated on the raised portion of this layer film (i.e. on the surface of the polyester film with a lower inherent viscosity), the Corrugation of the photographic emulsion layer on the ground of shrinkage during drying and the corrugation of the film base itself against each other and the occurrence from curling or curling in the entire photographic film is very largely inhibited. In general the degree of expansion and contraction differs depending on the types, number, thickness and properties of the layers to be applied to the base film, such as a primer layer, a photographic one Emulsion layer, a protective layer or an antihalation layer. Therefore, if the extent of the Base film itself ascribable corrugation is regulated depending on these factors of the coating layers, so it is that it corresponds to the extent of the corrugation that can occur due to the coating layers possible to largely reduce the curl of the entire photographic film.

In the case of a three-layered film composed of polyester films A, B and C, the direction is the corrugation depending on the intrinsic viscosities of the polyester films A, B and C or the thickness of each layer occasionally reversed. In such a case it is preferred to apply an emulsion to the raised portion of the film. Because a higher degree of transparency for photographic Purposes, it is preferred not to incorporate an inert compound into such a photographic film base to incorporate.

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It has been found that the extent of curl is large of the inventive polyester film layer in a larger difference in the intrinsic viscosity between the two outer layers, a smaller difference in thickness is between the two outer layers and a higher heat set temperature.

Photographic films made using the polyester layer films according to the invention were produced as film bases, are suitable as roll films, cinema films, plate-making photographic films, duplicate photographic films, 8 mm motion picture films, photographic Dry plates, flat films. And radiographic Movies.

Further, by drawing a suitable shrinkable coating layer on the polyester layer film, the Invention instead of mounting a photographic one Emulsion, in order to compensate for the corrugation of the layered film itself, a layered film or a layered foil is obtained suitable for writing, drawing or printing. ■

Another preferred use of the invention Polyester layered film is used as a raw material for the production of split or slit fibers.

Various methods, such as a beating method, a bending or kink method, a false twist method or a cutting method, have so far been used to produce threads by splitting a film-like or proposed film-like material. All such previous methods have the disadvantage that they are complicated Facilities and high production costs require and thus have low economic benefits. Furthermore, the threads obtained are lightly pressed flat

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and have poor softness, bulkiness and coating properties and thus result in shapes and a feel, far removed from such spun yarns.

Those obtained by cleaving the polyester layered film of the present invention obtained threads are spirally waved because of the difference in inherent viscosity between the Surface and the back of the threads have a difference in the shrinkage tension between them when applied high temperatures at the time of cleavage and at the time of swelling with solvents, the heat treatment after the cleavage and the post heat treatment after .dem stretching the film with it. Therefore have the filaments obtained have far superior softness, bulkiness and coating properties compared to those produced by common methods are obtained, while the high tensile strength, knot strength, plucking strength and durability, which is generally inherent in polyester fibers, is retained.

The split fibers can be made from the inventive polyester layer film by molecular orientation of the Layered film in the longitudinal direction either directly or after slitting and then splitting the film be produced either mechanically or chemically-mechanically. Specific means for splitting include a Process in which the oriented film is made into threads by twisting or rubbing on a thread winder or a carding machine, a method in which the oriented film is passed through a hammer, For example, a wedge or a cutting edge is knocked in the direction of the stretching by rolling or a process, in which the oriented film is swollen with a solvent to make it easier to split.

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The term "splitting" also denotes a method for producing thread-like material with a uniform Width using a micro slot.

The threads obtained have various shapes, such as, for example, a mass of completely separated Threads or a mass of separate threads, some of which are interconnected, depending on the one used Production method. Threads with particularly good softness, bulkiness and covering properties can, obtained when a longitudinally oriented film is split by twisting or friction and the obtained threads are collected in a cylindrical shape and at the same time the split portions or are subjected to fusel or surface roughening treatments by melting adhering portions of the threads or when the threads are inflated like a balloon, so that the fibers on the surface layer are partially melted be liable.

The threads thus obtained have excellent softness, bulk, coating properties and mechanical properties Strength and are suitable as fishing materials, for example as ropes or fishing nets, packaging materials, z. B. as transport bags, transport books, Wrapping tissues or automatic fastening cords or cords, construction materials such as various sheets and protective nets or braids, filter cloths, nets, covers, sails, Sewing thread and drive belt. The polyester threads thus obtained are particularly suitable for interior decorative purposes and outside, for example as carpets, such as base fabric, carpet pile, mats, simple floor coverings, Wall materials, such as wallpaper,

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Mat materials, curtains, interior decoration materials such as pillows, sheets or tablecloths. she are also suitable for knitting or warp-knitting, weaving, for thermal insulation, for the production of non-woven fabrics, for the production of paper-like webs and for the production of thermal insulation panels and also as split fibers used to treat heavy oils.

According to a preferred embodiment of the invention Threads becomes a thread by metallizing the polyester layer film and then splitting or Slitting the metallized film made. In this case, it is preferable to make the film more bulky for formation To subject slit fibers to a micro-slit treatment, and these fibers are useful for decorative purposes. Furthermore, split fibers, which are made of polyester film, ' containing a colorant dispersed therein instead of being obtained by plating the film, also for Suitable for decoration.

The following examples illustrate the invention. The various properties described in the examples were obtained on the basis of the following measurement methods. Inherent viscosity

Measured on an o-chlorophenol solution of the polyester at 35 C and expressed in 100 civg. stiffness

The measuring method is explained in the attached FIG. 1. A sample film A 1.27 cm wide and a length of 28 cm was taken in the measuring direction (machining direction). The sample was placed flat and a weight B was abandoned. The one between the sagging part C, which has a length of 7 »5 cm and the angle θ formed by the perpendicular was taken as a measure of the rigidity of the film.

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Wear and tear

Measured according to ASTM method D1242-52T. Using a Taber wear tester, the amount of wear loss of a film sample under a load of 1000 g was measured using a CS-17 wear ring. The speed of rotation was 70 cycles / min, and the number of rotations was 1,000.
Density of the respective films constituting the layered film

Each polyester having different inherent viscosities for forming the polyester layer film was selected from among same conditions using the same extruder as used for co-extrusion of these polyesters is extruded into a layered film to form a film of the same thickness as the layered film. The density of each. the film thus obtained was measured and it was assumed that the density equal to that of the respective Was films which form the surface layers of the layered film. That used to measure density The solvent was a mixture of n-heptane and chloroform.

example 1

Polyethylene terephthalate was made using a Catalyst made from 40 mmol% manganese acetate, 20 mmol% antimony trioxide and 40 mmol% phosphoric acid, the percentages being based on the weight of the starting dimethyl terephthalate are related. No inert compound was added or became in this polymerization reaction a fine powder of kaolin with a particle diameter of 1 to 3 microns as an inert compound in an amount of 0.14% by weight or 0.28% by weight to form various Polymer with an inherent viscosity of 0.50, 0.65 or

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- ιε -

0.85 and which were free of kaolin or contained kaolin in the specified amount.

Then two polyesters of different intrinsic viscosity were used, selected from the above polyesters, among. Co-extruded using a common extruder, so that the ratio of the pilm starch had the values given in Table I, with those in the experiments Five unstretched polyester layer films listed in Table I, 1-5 were formed. Each of the unstretched films were initially made at a ratio of 3.4 in in the longitudinal direction and then at a ratio of 3.8 in the transverse direction to form a layered film stretched to a thickness of 36 microns and then stretched for 30 seconds heat-cured in hot air at 205 ° C. The stiffness, density and wear loss of the obtained Films were measured and the results are shown in Table I.

The sheet films in Experiments 1 to 5 were all corrugated in the width direction, with the polyester film with the higher inherent viscosity was located inwards from the bulge.

For comparison, the properties of polyester films with different inherent viscosities (without layer formation) measured. The results are shown in Comparative Examples 1 to 3. These films revealed a flat shape after heat curing. Table I clearly shows that the layered films have increased stiffness over planar ones Have individual films.

In Table I, the "surface" means a film with a higher inherent viscosity and the "back" means a film with a lower inherent viscosity.

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Table I.

(Continuation)

Trial no.

Comparison search no.

σ> co co

Stiffness (of any surface • film

(* 3) back

49.0 46.5 '

48.0 46.0

47.5. 46.0

ro films (mg)

43.0
46.5

Density of the film Oberig / cm ⁵ ) area 1.3972 '1.3968 1.3955 1.3950 1.3970

Back 1.4015 1.4019 1.3973 1.3975 1.4021

Loss of wear and tear on every surface

back

27 , 0 33 , 5 23 , 5 35 , 5, 33, 5 25th , 5 19th ,8th 22nd , 0 22nd , 0 27 5

42.5

17.7

42.0

22.2

■ * 1) The rigidity of each film was measured only in the machining direction '2) The stiffness was measured with the surface of the film B after < ■ 3) The measurement of the rigidity was carried out with the surface of the film A after

43.0

1.3972 1.3950.

25.9.

directed upwards,

Example 2

Layered films were made in the same manner as in Example 1 produced with the exception that kaolin as an inert compound to polyethylene-2,6-naphthalate with a Intrinsic viscosity of 0.50 or 0.63 was added and that Stretching the film first in the longitudinal direction at a stretch ratio of 3> 4 and then in the transverse direction at a draw ratio of 3 * 7 to form a Film was made 23 microns thick and then thermoset for 30 seconds at 230 ° C became. The rigidity, density and wear loss of the obtained sheet films were measured and the results are shown in Experiment 1 in Table II.

For comparison, the properties of the non-layered polyester single films were also measured and the results are given in comparative experiments ^ to 2. ! Table II clearly shows that when polyethylene-2, 6-naphthalate was used as the polyester, the results were the same as in Example 1.

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Table II

Trial no.Packaging trial no.112

Film Thickness Ratio (%)

Amount of added kaolin (% by weight)

Intrinsic viscosity of the film (100 cmVg)

strength

(yu)

° stiffness of each film co Ξ density of the film (g / cm ^) ro

ο wear loss of each film (mg)

surface

back

surface

back

surface

back

(* 2) surface

(* 3) back

surface

back

surface

back

0.14 0.60 0.48 23
34.0 32.5 1.3597 1.3613 57.9 43.5

(* 1), (* 2) and (* 3) are the same as given in Table I.

Single film Single film

0.14

0.48

23

29.0

1.3613

49.3

0.14

0.61 23

29.5 1.3596

57.1

Example 3

Polyethylene terephthalates having an inherent viscosity of 0.50, 0.65 and 0.85 were prepared in the same manner as in Example 1 using no inert compound or adding a fine powder of kaolin with a particle diameter of 1 to 3 microns in an amount of 0, 14 % produced. In the same manner as in Example 1, polyester sheet films of the invention (Trials 1 to 6) as shown in Table III were prepared using two polyesters selected from these having different intrinsic viscosities. In these experiments, the films were biaxially stretched sequentially in the stretching ratios in the longitudinal and transverse directions as shown in Table III to form sheet films 36 microns thick and then hot air for 30 seconds at the temperatures shown in Table III was held, thermoset. Furthermore, in each of the experiments, kaolin was incorporated into polyester film A (described as "rear side" in the table) with a lower inherent viscosity and no kaolin was incorporated into polyester film B (described as "surface" in the table) with a higher inherent viscosity incorporated. The strength, elongation, F-5, stiffness, density and wear loss of each of the films obtained are shown in Table III.

The properties of the polyester films with the different inherent viscosities are also for comparison as individual films without layer formation as comparative experiments 1 to 4 shown in Table III.

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Ratio of film thicknesses (%) surface to back surface side '

Amount of added kaolin (% by weight

attempt
No.
1

5
4th

5
6th

50
50
50
50
50
50

70 70 70 50 50 50

surface

back

Table III

Intrinsic viscosity of each film (100 CmVgJ) surface side

Stretch ratio
(Longitudinal x
across)

Hardening furnace

0 0 0 0 0 0

0.14

0.14

0.14

0.14,

0.14

0.14, 0.65
0.63
0.75
0.63
0.65
0.75

0.50
0.50
0.62
0.50
0.50
0.62

5.9 χ 3.7 4.4 χ 3.3 4.4 χ 3.3 3.9 χ 3.7 4.4 χ 3.3 4.4 χ 3.3

205

195 195 205 195 195

to compare,

^ Ver

° search-

fl No. to _Λ

Single film Single film Single film Single film

0.14 0.14 0.14 0.14

0 , 63 3.5 X 3.8 0 , 50 4.4 X 3.5 0 , 62 4.4 X 5.5 0 , 75 4.4 X 5.5

205 195 195 195

Table III (continuation f

Strength (* 1) stiffness (* 3.J Physical Properties Reverse
page of stretched films ) Back
page Results of tensile strength Value - ₂
(kg / mm) ke i * 2) Return
• page Density c T, 3987 Loss of wear and tear 31 Testing 10 ^ 5 (JO Upper
area 47.5 les films 1.3985 (me ' ¹ 32 fracture
strain Fracture-
consolidate
k'eit 2
(kg / mm) 15.5
10.9. 36 - 52.0 47.5 (g / cm?) 1.3942 Upper
area 35 MD 91
TD 133 35
24 15, Ö £
11.1 K Verse.-
Part no.
co 1
OO 36 55.0 47.0 Upper
area 1.3987 40 ' "32 MD 69
TD 135 42
33 13.7
10.3 £ 2 36 54.5 49.0 ' 1.3943 1.3985 ' 42 33 MD 75
TD 140 43
31 15.6
10.7 P. ³
co 36 54.5 50.5 1.3939 1.3942 46 37 MD 110
TD 135 36
23 15.9 co 4 36 56.5 51.5 1.3913 41 MD 70
TD 137 43 *
32 2428 5 36 56.0 1.3943 40 MD 77
TD 1J8 42 6th 1.3939 £ 6 - 1.3913 •

! -

-24 a -

Table III (continued ) “Physical Properties of Stretched Films

Strength (/ 0

* 1) stiffness

Top and back side

Film density (s / cm?)

Attrition Loss (mg)

surface

Rear surface

Backside

Tensile test results

Elongation at break (%)

Breaking strength ρ (kg / mm)

■ b-5-vert (kg / mm)

Comparative test no.

36 36 36 36

41.5 44.5

45.0

46.0

1.4013 1.3985 1.5942

1.5916

21 MD
TD 120
99 22nd
24 10.8
11.8 50 MD
TD 55
150 40
29 15-1
10 ^ 9 55 MD
TD 57
155 42
51 15.8
10.7 59 MD
TD 60
157 44
54 15.6
10.8 2428

cn

Footnote: 1 *, 2 * and 3 * in Table III are the same as in Table I.

• Example 4

Polyethylene-2,6-naphthalate polymer with an inherent viscosity of 0.57 and polyethylene terephthalate polymers with an inherent viscosity of 0.65 and 0.55 were in the prepared in the same way as in Examples 1 and 2. Then the above polymers were passed through an ordinary co-extrusion machine co-extruded so that the films obtained have the polyethylene-2,6-naphthalate content given in Table IV and the strength of each film component was as shown in Table IV. It two unstretched polyester layer films were prepared (Trials 1 and 2). Then each of the films in the Lengthwise at a stretch ratio of 3 * 6 and then stretched in the transverse direction at a ratio of 4.1 to form a film 45 microns thick and then for 30 seconds with hot air at 215 ° C thermoset. The inherent viscosity and rigidity of the obtained films were measured. Also became the polyethylene terephthalate film surface and the polyethylene terephthalate / polyethylene-2,6-naphthalate film surface of the polyester layer film is each connected to a high pressure mercury lamp as a substitute for the sunlight during the predetermined periods of time and then the strength and elongation of the heat deteriorated films was measured. The results are given in Table IV.

The sheet films in Experiments 1 and 2 were curled in the width direction after thermosetting, wherein the polyester film having a higher inherent viscosity was arranged inside the corrugation.

5 0 9812/0698

For comparison, the results are with a film made only of polyethylene terephthalate with no mixed polyethylene-2,6-naphthalate existed, shown in Table V as Comparative Experiment 1. Revealed even after heat curing this film has a flat shape. The layer films using a mixture of polyethylene terephthalate and Polyethylene-2,6-naphthalate had very much increased stiffness compared to the flat single film due to the corrugated Shape. Table IV clearly shows that the layer films, which are a mixture of polyethylene terephthalate and polyethylene-2,6-naphthalate contained, exhibited very good weather resistance, which is evident from the results of the Radiation from a high pressure mercury lamp onto the surface of the polyethylene-2,6-naphthalate-containing film is shown became.

In Table IV, "surface" means a fiI with a higher intrinsic viscosity and the "back" means a fiI with a lower intrinsic viscosity.

The intrinsic viscosity of the surface and back film (films A and B) was measured on samples that were separated were taken at the time of melt extrusion.

509812/0698

Table IV

Attempt no.

PEN content in polyester filem A (% by weight) Intrinsic viscosity (100 cnr / g) surface / back

(* 1) stiffness

(* 2) surface (* 3) back

relationship

■ surface

PET

^ Backside irradiated surface

^ PET + PEN '

direction

Empty test (0) Elongation at break (%)

Breaking strength (k / 2)

Irradiation time (h)

Elongation at break (%)

60

Breaking strength (kg / cm ² )

Elongation at break

120

Breaking strength (/ ^)

5 VJlO PET top
area (PET + PEN)
surface 0.594 / 0.504 70/30 MD
TD MD
TD 48.5
46.5 48,
45, (PET + PEN)
surface 100.3
70.0 50/50 MD
TD PET top
flow MD
TD 105.3
71.2

2600

2.7 58.6

.25.5 32.5

830 1580

1750 1920

1.9 45.3

17.3 44.3

680 1430
1470 1970

2140

2940

2.3 49.5

13.4 $ 21

690 1450 ■ 1350 1690

1.8, 15.4 19.3 21J0

610 1120

1200 1490

Footnote: (1 *), (2 *) and (3 *) are the same as given in Table I. MD = machining direction and TD β transverse direction.

CX)

-F-

cn

Table V

Comparative example

Component of PET alone

Intrinsic viscosity (100 cm3 / g)

Stiffness (* 1) 41.8

Irradiated surface PET surface

Direction TD

cn o co

Empty attempt (O)

Elongation at break (%) Breaking strength (mg / cm Jf

κ) irradiation time (h)

60

Elongation at break (%)

Breaking strength (kg / cm)

ο σ) to

120

Elongation at break (%) '' Breaking strength (mg / cm2)

102.5 93.6

2440 2 580

2.1 16 ,?

750 1360

1.8 1.8

680 720

PET = polyethylene terephthalate MD = machining direction (longitudinal direction)

TD = Cross Direction (1 *) The stiffness of the film was measured in the machine direction only

Example 5

A film with an inherent viscosity of 0.61, the obtained by extruding polyethylene terephthalate alone and a film with an inherent viscosity of 0.56 obtained by extruding polyethylene terephthalate alone were laminated by the co-extrusion method to form a layered film, wherein the ratio of the strengths of the two components of the film was 30:70. The layered film was biaxial at first in the longitudinal direction at a ratio of 3 * 0 and then stretched in the transverse direction at a ratio of 3i3 and then for 30 seconds at 210 ° C at constant Thermoset length to form a film 100 microns thick.

A primer layer containing a hydrophilic copolymer of vinyl acetate and maleic anhydride was applied to the raised part (surface with a lower inherent viscosity) of the resulting polyethylene terephthalate layer film and dried at 60 ° C. for 10 seconds, which was followed by a heat treatment for 7 minutes at I30 ⁰ C connected. Then, an ordinary silver halide emulsion for negatives was coated thereon to a thickness of 20 microns and dried.

For comparison, a single layer film with an inherent viscosity of 0.61 and the same thickness was used made under the same film-making conditions. The amount of curl of the film was determined after viewing the film at a predetermined humidity was measured before and after & r development. The results are in Table VI reproduced.

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The curl value as a measure of the degree of curl used in Table VI was used measured in the following way. A circular sample with a diameter of 100 mm was made from the film whose Corrugation value should be measured, cut out. The sample was left at a certain relative humidity stand for 4-8 hours to initiate the corrugation. Then the corrugated circular sample was placed on a flat Plate ,, for example a glass plate with the corrugated part on the underside brought this sample with the flat plate came into contact at two points on the circumference. The distance (X mm) between the two points was measured by means of a cathetometer. The curl value is expressed in (100 - X) mm. The corrugation against the emulsion-coated Surface was indicated by + and the corrugation against the opposite surface by -. The results are given in Table VI.

Table VI

Film base curl value before curl value after

location development development

fo RH 70% RH ~ 50% RH 70% RH

At- shift-. ι * η * j. ο α λ. η game film ^{+ 1} ' ⁵ "°' ^{3 + 2} ' ^{1 + 0} single

same-film

* EH equals relative humidity

From the results in Table VI, it can be seen that the photographic films made using of the layer film according to the invention were produced as a basis, very considerably reduced dimensions Had curl.

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Example 6

A film with an inherent viscosity of 0.62, the by extrusion of polyethylene terephthalate alone was obtained and a film with an inherent viscosity of 0.50, the extrusion of polyethylene terephthalate obtained alone, were made into a laminate, the ratio of the strengths between the two film components set to 1: 1 and the film was then turned in the longitudinal direction at a ratio of 4.0 to form a layered film stretched to a thickness of 90 microns. The received Film was passed between rubber sheets and pressure was applied to the film in a direction perpendicular to the Applied stretching direction to split it into monofilaments with an average size of 1600 denier. The strings became to an extent in an atmosphere at 300 ° C twisted and bundled with about 1000 turns per meter, while the filaments partially melted to form a yarn. The yarn gave good knitting ability and weaving ability and had a good grip. In addition, the yarn had excellent softness, bulk and covering properties compared to split fibers on one under the same conditions formed single film were obtained.

Example 7

A film with an inherent viscosity of 0.60 obtained by extruding polyethylene-2,6-naphthalate alone was and a film with an inherent viscosity of 0.48, the extrusion of polyethylene-2,6-naphthalate was obtained alone, were converted into a laminate

50981 2/0698

works so that the ratio of the strengths of the film components was set to 4: 6. The layered film was made in the longitudinal direction at a ratio of 4.5 stretched. The film obtained was passed through rubber sheets and pressure was applied to it in a direction perpendicular to the direction of stretching to make it into threads with a middle size of 1000 denier. The threads became about 1000 twists per meter twisted and bundled while partially melting to form a yarn. The obtained yarn was good Knitting ability and weaving ability and superior grip. The yarn was also excellent in softness, bulk -and covering properties compared with a yarn, & s by splitting one under the same conditions produced single film was obtained.

5098 1/2/0698

Claims (10)

Claims / "iy stretch-oriented polyester layered film, featured through two or three polyester film layers, both the polyester film A and the polyester film B, like both outer layers of the layer film, made of a polyester with an inherent viscosity of 0.35 up to 1.0. are built up and the inherent viscosity of the polyester forming the polyester film B is 0.02 to 0.5 greater is than that of the polyester constituting the polyester film Ά with the layer film being corrugated in the width direction, wherein the polyester film B is arranged inside the curve. 2. Layer film according to claim 1, characterized in that that it has an overall thickness of 1 to 2000 microns. 3. Layer film according to claim 1 or 2, characterized in that it contains at least one inert compound with a particle diameter of 0.1 to 10 microns, consisting of MgO, ZnO, MgCO ,, CaCO ^, CaSO ^, BaSO ₄ , O iO p ₂ , calcium terephthalate, barium terephthalate, zinc terephthalate, manganese terephthalate, carbon black, graphite and / or pigments. 4. Layer film according to claim 1 to 3> characterized in that the polyester film building up the layer film is a film from a polyester in which at least 85 mole percent of the repeating units from ethylene terephthalate, Ethylene-2,6-naphthalate, tetramethylene tere- · phthalate, tetramethylene-2,6-njaphthalate or carbonate units and not more than 15 mol% of the repeating units are built up from another ester-forming monomer, or a film from one 509812/0698 Polymer blend is that of at least 90 wt.% Of the Polyester and no more than 10% by weight of any other polymer. 5 Layer film according to Claims 1 to 4, characterized in that that it has an F-5 longitudinal value of less at least 12.0 kg / mm. ' 6. Layer film according to claim 1, characterized in that that at least one of the polyester films A and B consists of a film composed of a polymer mixture Polyethylene terephthalate and polyethylene-2,6-naphthalate. 7 · Use of the layer film according to claim 1 to 6 as a film basis for a measuring tape. 8. Use of the layered film according to claims 1 to 6 as a film base for an adhesive tape. 9 · Use of the layer film according to claim 1 to 6 as a film base for a photographic film after coating a photographic emulsion layer on the surface of the polyester film A of the layered film. 10. Use of the layered film according to claim 1 to 6, wherein the layered film according to claim 1 to 6 below Formation of threads is split. 50981 2/0698