DE1960266A1 - Process for the remuneration of microporous film material - Google Patents

Description

1960268

8153-69 / Dr.ν.ß / Be

Oasis Mon. IU 10
V.St.A. Patent Application
7U9 ^z ! -77 filed December 2nd Ί968

IHMONT COHPUiLA-TIOM New ,, York, Ν.Ϊ., V.St.A.

Procedure for remuneration; of microporous film material

The invention relates to a method for remuneration of microporous foil material made from a thermoplastic elastic polymer.

Microporous Ifolienmaberial as a leather razor made of a fibrous base material, such as a relatively thick woven fabric or a .Fasfleece, which is impregnated and coated with a much thinner ochicnt of a microporous polymer, such as a polyurebhan, is per se canb. I'Olienmaberial from such materials was already feminine as a substitute for leather for. "Upper leather" or "upper parts from men’s and. Damon Schuhon used» BeL Herr-.in ·· shoe upper parts beb. requests the appropriate be D ick 3 the JTo.lien · materials st v / a 1.5 to 'i, 8 mm, while the Sj'olierunateci.uL-thickness in Uarnonschuhoberbeileri c-jtwa ü _} 8 p.s 1,: mal beb rag b "The gcüüto '" ceil of the FoILemaaterialisbär-ki bsaüahb in every fi'all made of one fiber ! "iabarial and the microporous" folyurebharischiehfr on dom Fassemaberial Isb thin, a, B, ebv / a 0.25 bi ο 0, ^ 1- mm dj ο ic "

1980266

The invention relates to the treatment of something different microporous foil materials and. is "especially for her-. ■..,, position of better over-leather or upper ax. of shoes, as well as for the production of other objects. That microporous film material that is compensated according to the invention, • is not characterized in its extensibility by the presence of a reinforcing fabric such as a fibrous material Fabric or non-woven fabric, limited. It is about them -. entire thickness essentially made up of a material not made up of fibers elastomeric polymer material ,. in particular made of a polyurethane material. In contrast to the usual Leather substitute materials, the elongation at break of which is about 20 to 40%, can be used in the film material treated according to the invention much more than 50% are stretched, e.g. considerably over 100% and usually over 200%.

The method according to the invention for the treatment of microporous film material aas a thermoplastic elastomeric polymer, which has no film material ... made of preformed fibers as a component and is 0.63 to 2.5 mm thick, is characterized in that the film material. ψ at a temperature which is below "the temperature at which the material collapses and loses its porous structure, but is within 40 0 of this temperature", ■ allows the surface to shrink by at least about 5 7 ».

The microporous film material treated according to the invention, '. that is flexible and not reinforced, has a thickness of: at least 0.63 mm, e.g. about 0 ^ 75 to "2.5 'inni and preferably - · - about O ₅ 76 to 1.8 am, The heat treatment takes place "in such a way that the film material is allowed to shrink in the plane of the surface * This heat treatment" improves, "as has been found, the properties of the B'ol'ieiimaberräls considerably,

BATH ORIGINAL 0 09828/1 7-fiT.

e.g. through. Increase in flexural strength or by the Improvement of tear strength and other mechanical properties. The heat treatment makes it possible the properties of adjoining surfaces or successive foils, which are produced on an industrial scale precise monitoring of the manufacturing conditions for the microporous sheet material becomes difficult is to - balance; Such a heat treatment can result in films that are not all subject to the manufacturing regulations have the required properties and are therefore incurred as waste or are sold as a second choice, improved so that they are equivalent to a material of first quality. This is of considerable importance in the large-scale manufacture. The method according to the invention also enables the production of a microporous Low density film material in a first stage, the density being lower than that of the end product is desirable, with the material subsequently being converted into a microporous product with good properties and a larger one Density can be transferred with good vapor permeability can. Further advantages of the method according to the invention emerge from the following description.

The method of the invention is particularly useful for the production of substitutes for shoe upper leather. In the manufacture of shoes it is common to use the upper leather usually cut using a machine tool and to prepare and connect the parts of the upper part, with any duplicating material used or Lining is also prepared, e.g. by sewing and / or gluing, around the upper part of the shoe for mounting on the last to get ready. After attaching the insole to the bottom of the last, the upper part is placed on the last upset, tightened over the wooden strips so far,

00-98 28/1 T 6 1

that it is firmly attached to the last and connected to the insole. The covering is generally accomplished by means of devices that grip the upper and pull it over the edges, for example on the toe part and the side parts. ^x

During the fitting of the upper parts of the shoe the edges of the upper leather are generally "sharpened" by making a bevel on the inwardly facing "flesh side" of the Ledex ^ s is cut at the edge and the sharpened edge is then glued, folded once and pressed on, a clean finished seam or other edge being obtained.

The usual methods of making shoes are in How American Shoes Are Made, 3rd Edition, 1966, United Shoe Machinery Corporation. .

Excellent shoes were made with foil material that was tempered according to the invention instead of the usual Upper leather. The shaft from the tempered according to the invention. Foil material not only corresponds unusually well to this Last without wrinkling or wrinkling occurs, but also retains its shape on the last very well after the material is removed from the last . has been, especially if the upper part of a conventional heat treatment, e.g. with heat alone or with “The material has very good properties when Sharpening, especially if moistened with water before sharpening. The from the invention Shoes made with tempered film material are comfortable and the shafts show very good wear resistance. in the

9-828 / 1761

1980286

... ■■■■■■ ... - 3- \ :. .-., ■

In contrast to many shoes, which are reinforced with the usual fabric Leather substitutes have been produced for shoes made of olie material tempered according to the invention * do not have the difficulty of having to pull up on; the fabric pushes through the strips or the surface takes on an orange peel-like structure ».

The microporous foil materials treated according to the invention have pores that are suitable for those with 20/20 visual acuity are not visible. These pores have a maximum dimension of less than 100 μm, observed on the plane of the surface The top or bottom of the material on a cross-section of the material, as can be seen from the following, is the pore size is generally considerably less than 50 µm in the maximum extent.

The attached illustrations show photomicrographs of various microporous foil materials that have been used or produced according to the invention. These photomicrographs were obtained with an Easter electron microscope (i'yp JSM, Japan Electron Optics Laboratory Co., Ltd.), showing cross sections of the polishing material obtained by cutting the film thickness with a razor. When preparing for viewing, the cut foil material is given a very thin, even metallic coating of gold-palladium about 300 times thick. The coating may be by vapor deposition of the metal on the sample in a high vacuum, ^ »ß» are applied at 10 mm Hg _ä wobäi the sample while depositing the tails Me 'pivoted' Wim, .'damit ^das'Metall: gleichiaäßig diieOböüfläctie over the sample ₃ including the columns, "is distributed", the coating serves to dissipate the electron charge that would otherwise collect on the surface of the sample, "if this is the electron

ft Π Q ft O Ο / Ι η β 1

beam in the scanning electron microscope.

Each photomicrograph is given an approximate size scale. When considering the Mikrophobografien "must be noted that the Easter Elektronenmikrpskop has a large .Fokussierungstiefe, which is about the 30Ofache those eines.Lichtmikroskops that about 300 / um -.

at 100x magnification or 100 / µm at 1000x magnification what makes you practically inside

the pores can see. ■ ■. ■

The method according to the invention has found the greatest breadth of application in the treatment of microporous film material which has a structure according to FIGS. 2 to 5, the pore system being cavities. 12 (FIG. 3), whose maximum dimensions are in the range up to about 45 μm and which are connected by connecting passages 13 which can have much smaller dimensions, for example a maximum dimension down to about 1/2 μm . The walls of the cavities can be very thin, as the wall between the two cavities in Fig. 4 shows at the top right. The other walls that can be taken from Pig, 4 are seen from the broad side or viewed at an angle, so that their true thickness is not readily apparent. The thickness of the walls seems to be in the order of magnitude of ^: 1 to 10 μm. Fine cavities 14 can also be present in the walls of the irregular cavities 12. A suitable process for the production of such a microstructure consists in that, for example, on an auxiliary carrier, a thick layer of a mixture of a leachable material, v / ie potassium chloride particles of microscopic size, with a solution of a thermoplastic polyurethane in a solvent , e.g. _a dimethylformamide ', and the layer on the carrier is treated with a liquid agent for coagulating and leaching, such as water,

BATH ORIGINAL 009828/176 1

which is a niclite solvent, the polyurethane coagulated to form a microporous film. Treatment with the coagulant is continued until essentially all solvent and leachables are removed. The obtained water vapor permeable Flexible sheet material is dried and stripped from the auxiliary carrier.

Another type of microporous sheet material made according to the invention can be treated, has a structure according to FIG. 1, wherein the pore system is essentially no larger Contains cavities 12, as shown in Fig. 5, but in their place many fine, interconnected Has pores of significantly smaller size. A method for making such a product makes of a mixture of the thermoplastic elastomeric polyurethane, which is uniformly in a volatile solvent mixed with a miscible, less volatile non-solvent distributed, use. According to a preferred embodiment of this method, a clear, hot solution of the polyurethane in the mixture of the solvent and the nonsolvent cooled until cloudy colloidal dispersion of the polyurethane is formed. This cloudy dispersion is applied as a thick layer on the auxiliary carrier poured and the solvent and the nonsolvent are evaporated. The film is then removed from the carrier.

Microporous films that have been treated according to the invention can also be produced by other processes. · The invention is not in its usefulness on substances limited, which have been prepared as described above or in the examples. It is applicable to all substances

OO9.ß? .R / 176-1

which are not through a reinforcement made of fiber material are limited in their dimensional stability. Other coagulation methods can be applied to the thick layer of the mixture of the polyurethane solution and the leachable Treat material. Such coagulation processes include cooling the mixture, e.g. -78 G or steaming the mixture with a non-solvent, e.g. in a humid atmosphere, or simply evaporating the solvent, preferably like this slow that the formation of, macroporous bubbles or Holes-in the foil is avoided or by using it various combinations of these coagulation processes, e.g. by freeze-drying before the leachable material, such as table salt or the other microscopic particulate material is removed. Instead of or together with Other microscopic pore-forming particulates can be used in addition to the salt particles. These Substances can be, for example, starch particles that are produced by treating the coagulated layer is removed with an aqueous starch degrading solution such as an enzyme of a known type or they can be other microscopic solid particles that are present in the polyurethane solution are insoluble and either by treating the coagulated film with water or with another suitable solvent for the particles can be dissolved out, the solvent not being a solvent for the polyurethane is. The particles can also be destroyed or removed in other ways. Examples of particulate matter of this type are sodium carbonate, oxalic acid, ammonium carbonate or suitable so-called microballoons forming substances. The particulate material forming the cavities can also be in the form of dispersed microscopic There are droplets of a liquid that is insoluble in the polyurethane solution, or it can be in the form of

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0 9 8 2 8/1761

1980266

■■ '■ .. - 9 ■ - ■

Via microscopic gas bubbles 'the particle size' ^{: of} the material composed of microscopic 'particles is considerably below 100 µm' and preferably below '50 µm and above about 'I / µm', in particular in the range τοη about 3 to 20 µm. The ratio between ^the: total volume of material. 'From the - · microscopic cavities ih forming particles ztim total volume of the polyurethane Löstmg can, for example in the range from about 0.5: 1 to 5: 1 or 6: 1,' preferably in / Range _: from about 1: 1 to 3: 1. Z * B. 178 g of the sodium chloride particles can be mixed with 333 g of a 30% solution of the polyurethane in dimethylformamide, a volumetric ratio of salt polymer of 1: 1 being obtained. ■ - '^; · ■ '■ · ■■ ^: V'"'

The heat treatment according to the invention can be carried out before or after the microporous material is tempered in one or more process steps. A very suitable tempering process consists in treating the surface with fine droplets of a solvent and heating in such a way that the microporous structure partially collapses along the surface and a thin, molten polyurethane skin is formed on the film häufig'eine series of very small impressions spaced apart, bounded by molten polyurethane material, for example, a thickness of 2-15 _{/'um..'besitzt}} on this surface _o Other 'suitable VergütungsbehandlUi) .-: consist gen " in the application of a 'thin. Oberflächenschiciit the Obero ffläche'der BiikropörÖsisti "ö'ülia _s 2.B, in the form öiher itfäßrigeu üifäü-Lsion. of a suitable .polyaierisats, aB »an illkjXacryLatpolyiiierisats' ο ti sr- -mischpoiymerisata _ä a βα.ηοί $ ϋΐ4ι? of batylaerylate, is about 15 % . Äcrylniti'il id .sfewa 1 ". To 2 '% .I'bacoQsäur" © _r' wherein DAA polymer beini uaxfcer JBirischluß a urea-fformalaaaya Kondeii · -

f% η an ^ ζ> ι 1 1 es

sationsprodukbs can be crosslinked in the! emulsion in a manner known per se. The amount of polymer can be so small that the pores are not closed or it can be sufficient to form a very thin layer less than about 1 µm thick. whereby the appearance of the material is improved without reducing the water vapor permeability; is significantly reduced. The outer coating can be continuous. Represent a layer that gives the material a patent leather sheen. You can thus use a conventional solution of polyvinyl butyral in an organic solvent. Apply in a mixture with a solvent-soluble melamine-IJOrmäldehydharz, evaporate the solvent and cure or crosslink the mixture. Another suitable tempering treatment consists in tanning the material with a solution of a soluble dye, ¹ for example from the group of "Irgaceb" colors according to US Pat. No. 2 55 '' 056 in solution in methanol according to In a preferred embodiment of the invention, dyeing precedes treatment with a sprayed-on solvent or application of a coating, or both. The heat treatment according to the invention should preferably follow immediately after the evaporation of volatile substances that are used in the tempering treatment

The-heat treatment in accordance ^with: the present invention is carried out, · during said non-reinforced, microporous polyurethane · 'film material lying free, so that it can shrink in dsr NoUser-a »The duration and iemperatux ¹ of treatment hängfr"■' ■ of of _5> eweiligen Zusaiam-maubsung of Pol / urethane from "■ 'you should not be so high' do that 'ä & s material melts' or a combination wasteland is .Poren.Verursach / t''WircL ^'Di'e:' '' The duration and temperature of the treatment should be, "Jedooh ¹ hochgeiiig", by an area shrinkage above & b \ i & 5% ».

BATH ORIGINAL 0Q9Ö2'8 / 1 7ßi "

preferably in the range of about 5 to 40%. In the case of a film material with a structure according to FIGS. 2 ″ to 5, an area shrinkage of approximately 10 to 20 % has given the best results. In the case of a film material with a structure according to FIG below the surface are on average larger than the pores in the body of the film, a shrinkage has o shown from about 20 to 40 ° / in the surface of the best results. the temperature during the heat treatment is preferably at least 2 ⁰ O below the temperature at which the microporous material collapses, i.e. the temperature at which the film material loses its pore structure, a phenomenon that can be recognized by the fact that the dry film becomes transparent or translucent. The temperature is well within 40 ^° C. of the temperature, at which the material collapses and usually within JO ⁰ G and often even well within 15 ° C of this temperature, e.g. 5 to 15 ° C belowhal b the temperature at which the material collapses .. The duration of the heat treatment is preferably quite short, well under 1 hour and usually well under 15 minutes. The optimal temperature and duration of the treatment can be determined by simple trial and error and depends in part on the efficiency with which the heat is transferred to the surface zone and through the surface zone of the microporous film, the film itself being a heat-insulating material. In general, the treatment in a convection oven lasts more than 1 minute, for example about 3 to 5 minutes The temperature measurement in a convection oven is carried out by means of a thermocouple which is placed in the air space tightly, for example directly above the surface of the film material.

0 0 9 B 7 B / 1 7 6 1

According to a particularly preferred embodiment of the method according to the invention, no or only a very small change in thickness of the material is observed during the heat treatment. According to another embodiment, which is particularly suitable when the microporous structure is present. the heat treatment has a lower density, e.g. a density of. about 0.2 to 0.3 g / cm, the treatment is carried out in such a way that a considerable decrease in thickness is achieved and thereby a greater reduction in

»Seal is achieved, whereby a material is produced which has a density above 0.35 g / cm ⁹ , for example from 0.35 to 0.5 g / cm. Treatment under conditions in which the strength of the material is reduced can also be used when a film which cannot be used for other purposes is to be rendered useful for certain purposes. For example, a material 1.1 mm thick that is too thick to be used in place of upper leather on women's shoes, although it would be suitable for other purposes, can be subjected to a heat treatment to bring the thickness to "0.8 mm, which is useful to decrease. preferably, the microporous films substantially free of visible pores (macropores) both before and after heat Behandlunge the increase in density is preferably about 4.5 h / ", for example above 10% and even.

up to 120 % or more, although preferably a density increase between 20 and 70%, especially 25 to 50%.

Surprisingly, various properties of the microporous films are achieved by changing the conditions of the heat treatment. For example, heat treatment under moderate conditions, e.g. at about 10, gave. .to 20 ⁰ C below the temperature at which the material collapses, over 10 min, an increase in density without a change in thickness and a considerable increase in flexural strength without an increase in tear strength or without

BAD ORiGfNAL

0 0 9 8 2 8/1761

the .water vapor permeability .of the · .öOIia. » With the ■ application of tougher conditions ^ a.Bp with p ^} G üaeerhaXb- the iDeaiperatur, with der.das. .Material together.üfalIc , üsr, '10 .mj.? I ₅ became aiii very. _; Significant diehteamstieg and ainilastieg dor '. Tear resistance observed, while the film still possessed a high water vapor permeability. Figs. 6 and 7 show cross-sections of products obtained by various heat treatments of the same ilusganife material were, namely a foliage material, with a denser. base layer and a less dense upper layer »In these Hikrophotogra.fien _: " the underneath surface of the, foil, runs diagonally at the lower right corner. of the picture, wasxid xlie upper surface diagonally at the upper left, corner-.the picture runs 'The -.' white band. represents .the background. and is .not to be considered; take into account »Fig *. 6 'is a product. that was obtained after moderate heat treatment, lig. 7 ^: is a. Product obtained after a more drastic heat treatment with a subsequent considerable reduction in the bend.

The; Properties of the treated material: are generally roughly the same in width and length. This is not the case with leather and certain synthetic leather substitutes, case _{3 in} which the orientation in a calibration limits the way in which the foil remains; The manufacture of shoes or other products is allowed to be made-b-eii.körinen = this -own- * creation "of the .o ^ fanclungs" according to the lier.geatelltsn! Foils allowed. The Äustfhneide ^ '^ ELe ^: sferitfönd ^ Hig! Surfaces, represent .- _: '■ ■.

The li / ä'cM ^ bBü ^ Mlif ^ 'will Xm, allgeßleiiion; m einani' hot-air. ' stroiii '& rcligiä.tüUrt ^' - ^^ B, Ln ^ einia göalgneten KonTektions "- oven, while the Follenmateriai horizontally on ainem '! rager

iiöta2.a, /. i7ii '

960266

lies, άΰ.Γ the güminDcJibo Scürurapfiinn; in "dar Übena allowed, z _a ß» ώΐη .-. ϊ.'α Ckit'cer odee a series of closely uöbexie.l.aander lie ge ad e υ. Rolls or υ L aera endless sails buohsbr-y Lien., Weiia dao Wa ce rial j the "bühruidolü v / ecden should be present in the form -.iLiiör continuous iTolie, little or no ο longitudinal tension is applied to the material by d-rsn Ox'en au. demand »The ± 'Ό Ii enma barial can also be, but is vrenigö desirable: is;, hung up vertically, become, iniioespecial wsnn the width of the ilaterials small and. the iüctii; erki * af b, aie facing shrinkage., therefore small isb «

öbabb. by. Heating by convection by means of its hot gas, the heat can also be heated up by radiation,: <5, B. by infrared heating devices, or. .Heiavorrichtungen by dielectric, such as those, arbeiben with Hundfunkfrecjuenzen or conductive heat .by -. wherein the material is performed over hot rollers, is guided such »B _o conventional hot plates, or durch.ein hot liquid medium, wherein, a shrinking in the plane can take place »

The solid polymeric material of the microporous films treated according to the invention is a thermoplastic elastomeric polyurethane material with a viscosity value. At least 0.6, preferably at least about 0.3 and in particular at least 1 -or-above -from iiolekülabschnifcten-raib U ".ce, brace bindings, · and in between- ■ .. lying longer sections, the s, B _a consist of polyester or polyamide. =. M ^ -urethane bonds are.. azOmatisohsn.Diisocyanaten abolished.,. ■ .- ■

1
as from JJiphenvlnisblian-ρ, ρ '-disocyanate and eollen .sogenarinbe ha τ be section. t; bo in the polymer molecule. form, while .the ^one ■ other Abachiiibfee _s a "ß" dio Vo Lva ^ l'he "od.er.-Polyä'bb.ers3 | SiaeacG are ... flexible -odor soft" polyurethane of this type are located -an

BATH ORIGINAL

098 2-8 / 178 1

known. You can, for example, by converting a polyester with Hydroxy1-Ehdgruppen with a relatively low molecular weight or a polyether, e.g., having a molecular weight below 6000, preferably between 800 and 2500 a low molecular weight glycol and a diisocyanate.

During the production of the polyurethane one can Polyester of a hydroxycarboxylic acid ,. e.g. polycaprolactone, or a polyester made from a glycol and a dicarboxylic acid, e.g. ethylene glycol adipate or 1,4-butanediol adipate or use a mixed polyester of these components. Examples of other dicarboxylic acids that can be used instead of or which can be used in addition to adipic acid are succinic acid, pimelic acid, suberic acid, azelaic acid or sebacic acid or aromatic acids such as phthalic acid or terephthalic acid. Examples for others Glycols that can be used to make the polyester are Ί, 6-hexanediol and 1,8-octanediol. The. Most useful polyesters are aliphatic polyesters, with the groups

-C-O-

separated by aliphatic chains averaging about 3 to 6 carbon atoms in length.

Typical polyethers that can be used to form the soft segments in elastomeric polyurethanes are usually those with an aliphatic character. One useful species has the formula H (EO) H, where E is a

rtn ger alkylene radical, e.g. * a tetramethylene-- or Λν1 ^; Γί ( ^; ϊ! r.üay pi-opylenrest isl and η the polymerization ^ for- ο ι ': ti more fi ;.

Ü Ü P: U ■ ·>< ■ '1 7 8 1

196026S

The "preferred diisocyanate is diphenylmethane-pjp'-diisocyanate, however, other diisocyanates as such or in admixture with the former can also be used. Examples of other diisocyanates are 2,4-2joluene diisocyanate, PjP'-diphenyl diisocyanate and tetramethylene diisocyanate.

The low molecular weight glycol acts as a chain extender. The "preferred Eettenverlängerer is Tötramethylene glycol, however, chain extenders other than such or can also be used ™ can be used in a mixture with it. Examples of others

. difunctional chain extenders are other dihydric alcohols, such as ethylene glycol, hydroxyamines, such as 2 ~ aminoethanol, Diamines, such as ethylenediamine or water. The amount of the chain extender used is preferred very high, so that a thermoplastic product with a high viscosity number is formed.

In the preferred group of polyester-polyurethanes which have been prepared with the aid of diphenylmethane-pjp'-diisocyanate, those with nitrogen contents in the range from 4 to 5% are preferably in the vicinity of 4 1/2%, fc for example 4.4 up to 4.6%, particularly suitable, as has been found.

The polyurethane material should have a melting point of at least 100 ⁰ C, preferably of above 150 ° C, for example from about 170 to 200 ⁰ C, measured by differential thermal analysis or by differential calorimetry. The material should, if it is formed into a smooth, void-free thin film 0.2 to 0.4 mm thick, have the properties listed below in

009828/1761

Dimethylformamide, followed by careful evaporation s of the solvent can be prepared in a dry atmosphere. The films are said to have tensile strength

of at least 210 kg / cm, preferably at least 350,

for example about 420 to 560 kg / cm, an elongation at break of at least 300%, preferably of at least 400%, for example about 500 to 700%, a modulus of elasticity of at least 105 kg / cm, preferably at least 350, for example about 560 to 770 kg / cm ² , a cutting line modulus 100% (force divided by load at 100 % elongation) of

at least 28 kg / cm, preferably at least 84, e.g.

have ρ
110 to 134 kg / cm /. These mechanical properties are measured according to ASTM D882-67.

The polyurethane, which is present as a thin film as examined above, should fully recover from a stretch of 5% at tree temperature (23 ° O), but preferably »assume permanent deformation after re'sc has been stretched 100%, as measured, for example, according to ASOJM D412-66. The deformation is usually in the range of about 5 to 20 %. The best fabrics used so far have a deformation in the range of 10 to 20%, e.g. about 15 % · A typical material shows a tension deformation of about 24 to 26% immediately after loosening the clamps, from which it is stretched at 100% for 10 minutes has been held, while the permanent deformation, which is measured here as stress deformation 1 h after the clamps have been released, is 14%, measured on a film sample 1 cm wide with a caliber length of 5 cm. and a loading rate for 100% elongation of 254% / min. Preferably the material has a Shore hardness of at least 75A, preferably from about 90A to 60D, measured in accordance with ASTM DI7O6-67.

0982

The polyurethane material can be made from polyurethane as such exist. The use of polyurethane materials, the mixtures of "Represent polyurethanes with other high polymers, such as with polyvinyl chloride or copolymers of vinyl chloride, in which Vinylac et at contain iat as a comonomer, such as Bakelite VYHH or VAGH (trade name), or with a rubber-like copolymer made from a conjugated one Diolefin and acrylonitrile, e.g. a copolymer made from ™ butadiene acrylonitrile (Hycar IO31, trade name). The amount of the other high polymer material is in generally below 40%, such as 10 to 20%, based on the total weight of the mixture.

The microporous film material treated according to the invention preferably has a density in the range from about 0.35 to 0.7, preferably in the range from about 0.35 to 0> 5 g / cm. The specific degree of shrinkage that occurs during the heat treatment occurring depends in part on the Structure of the material and its history. The density of the microporous film material before the heat

> Treatment is preferably below about 0.5, for example in the range from about 0.25 to 0.45 g / cm. The density of the polyurethane itself is usually about 1.2 g / cm ⁵ . It follows that in the microporous film · ■ material consists of about 1/4 to 1/2 of the volume of air.

The heat treated microporous sheet material according to the invention preferably has an elongation at break above 50%, for example in the range from about 300 to 400% or above, a tensile strength above 35 kg / cm V

e.g. in the range of about 60 to 100 kg / cm ² , an elastic

ο .- ■■■■

modulus above 2 kg / cm, e.g. in the range from about 4 to

009828/1761

9 kg / cm ² and a tear strength (ASiIM D2212-64) above 1 kg / mm thickness, for example in the range from 2 to 5 kg / mm thickness. As will be seen from the following examples, the use of the heat treatment according to the invention produces significant improvements in the physical properties of the sheet material and enables good products to be made from weaker or less perfect microporous sheets while maintaining their permeability to moisture vapor. Before the heat treatment, the microporous film should preferably have an elongation at break of more than 50 % *, preferably of 7 * 0% or more, and a tensile strength of at least 5 kg / cm. Both before and after the heat treatment, the water vapor permeability should be maintained. The water vapor permeability should be at least 200 g / m 2/24 h, measured according to ASOM E 96-66, method B. It is also desirable that at least the outer surface of the film, after suitable annealing, be resistant to the passage of liquid water. For example, the coated film should have a hydrostatic compressive strength in accordance with British Standard Sheet 2823/1957 above 100 mm Hg.

The following examples illustrate the invention. In the examples, all pressures are atmospheric pressures if nothing other is mentioned. The stated proportions relate to the weight, unless otherwise stated is.

To> ie 1 1

According to the invention, a film material was heat-treated! which was a composite film pigmented from a microporous thermoplastic elastomer

009828/1761

Polyurethane represented in two parallel zones or layers one on top of the other. The base layer was about 1.2 m and weighed 590 g / m corresponding to a density of 0.48 g / cm. It was covered by a top layer about 0.5 mm thick. The overall density of the material was 0.42 g / cnr.

The thermoplastic polyurethane elastomer was endgrupp hydroxyl s of a molecular weight of about 2 000 as well as from 1,4-butanediol and 4,4-diphenylmethane diisocyanate produced from a polyester of ethylene glycol and adipic acid. Two homogeneous pigmented items containing finely ground sodium chloride dispersed in a solution of the polyurethane in IT, N-dimethylformamide ("DMi ¹ ") were prepared. In the one paste that was used for the base layer and is referred to below as the substrate paste, the weight ratio of sodium chloride: polyurethane was 1.78: 1. In the other paste used for the top layer, hereinafter referred to as top layer paste, this weight ratio was 3: 1.

To produce the pastes, a JO% solution of the Polyurethane with a viscosity number of 0.77 »measured in DMF, produced in dimethylformamide. A pigmented approach was prepared by mixing 40 kg of the polyurethane solution with 9 kg of carbon black and grinding the mixture.

The substrate paste consisted of 48.4 kg of the 30 # polyurethane solution, 750 g of the base batch, 1.6 kg of DMF and 26.8 kg of micropulverized sodium chloride (13 μm D average particle diameter), while the paste for the = top layer consists of 37.3 kg of the 30% polyurethane solution, Consisted of 8.9 kg of DMF, 6.25 kg of basal batch and 37.5 kg of the same micropulverized salt.

009828/1761

The average particle diameter of the salt is measured by common failures and becomes "of measurements the increase in light transmission versus time of a homogeneous suspension of the particles in an organic Liquid measured. Shadow photographs confirm that the powdered salt has no particles "whose Maximum dimensions are above 100 µm and only a few Particles larger than 50 µm in size.

The substrate paste is applied to a porous auxiliary carrier with a squeegee and then the top layer paste is poured directly onto the first poured paste with a squeegee positioned higher up. The carrier is then passed through a water bath, for example at 20 ° 0 over 3 b. or longer, with the two layers coagulating thoroughly. The carrier is then carried out by ironing through a borrow of leaching tanks in hot water, for example at 60.degree. C., for a few hours in order to leach out the sodium chloride. Subsequently, the structure is dried thoroughly in a hot air oven at a temperature of eg 120 ⁰ O. The dried film, after being stripped from the auxiliary carrier, has a cross-section corresponding to that of Figure 5, which is a cross-section showing part of the film at and near the zone where the two layers meet. This zone, which is parallel to the upper and lower surface of the film and is not shown in the photograph, looks in the photograph as if it is diagonally at an angle of about 45 ° from the lower left edge to the upper right edge of Fig. 5 runs. The surface of the film, which was in contact with the porous, somewhat rough auxiliary carrier and had been stripped from the auxiliary carrier, has a relatively rough, somewhat fibrous appearance and a corresponding feel.

009828 / ^ 76 1

The dried film is then remunerated by that the surface is treated with a fine spray of droplets of dimethylformamide, the Droplets touch the surface in small zones at a distance from each other. Very shortly afterwards, within seconds the surface is treated with hot air of e.g. 1QO ° C, whereby the solvent-enriched polymer melts together on the surface and the solvent evaporates quickly and a product is obtained whose pore structure collapses on the surface and which has numerous, has very small flat indentations on the surface by a skin of molten polyurethane are surrounded. This treatment leads to a darkening of the surface, increases the surface strength; against that Penetration of liquid water and results in a surface finish which roughly resembles the hair cell pattern of natural calfskin.

A dried self-supporting sheet material produced in this way is then treated with heat by being placed in a draft oven for 3 minutes, in which dry air of 168 ⁰ O is blown across it at a speed of about 100 cm / sec. will. The foil lies on an open grid in the oven. During the treatment, the film material shrinks in the longitudinal direction and in the width, the area shrinkage being 5 to 8 % . The thickness does not change significantly. The change in density therefore corresponds to an increase of about 5 to 8%. While the flexural strength of the material, measured by the formation of outwardly folded cracks during the cold flex test according to ASTM D2097-62X with a flex tester from Newark Leather Finish Cq. in an atmosphere of O ⁰ O less than 13 »5 h with the material

00982 a / 1761

that is not heat-treated, the heat-treated material withstands well over 25 hours. The test was then terminated because an edge crack occurred, which may have been caused by improper clamping in the test. The improvement in flexural strength is achieved without affecting the water vapor permeability of the film; surprisingly, the water vapor permeability according to ASiCM E96-66 method B actually increases from 420 g / m / 24 h before the heat treatment to 480 g / m / 24 h after the heat treatment at. The tear resistance according to ASTM D2212-64 remains unchanged. The temperature at which the starting material
measured in the same furnace.

Example 2

at which the starting material collapses is 19.2 ⁰ C,

Example 1 is repeated except that the film is not coated by spraying on dimethylformamide by applying a very thin discontinuous surface coating of an emulsion of a polyacrylate ester takes place, the layer corresponding to an amount of about 10 g / m polyacrylate.

The film is then treated with heat as in Example 1. After 34 h there are no outward folds Cracks are visible (in the same bending test as in Example 1) and the test is terminated. In contrast, develop such cracks appear before the lapse of 18.5 hours in the same material that was not heat treated. These The flexural strength is improved without the water vapor permeability of the film being reduced,

which is well over 5 ** Ό g / m / 24 h, measured as in 'Example 1., ■

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1960256

- 24 Example 3

The sheet material treated with heat in this example is, a non-tempered microporous material composed of a single layer with a density of 0.40 g / cm3 and a thickness of 1.9 mm. The pore structure corresponds to that of Eds. J and 4.

The film is made from a thermoplastic elastomeric W polyurethane, which is produced as follows:

To 20.7 kg of pure N, IT-dimethylformamide ( ¹¹ DMF "). In a 38 liter reactor, 4423.8 g of a polyester with a molecular weight of 2000, which is made from 1 mol of 1,4-butanediol, 1.13 mol of ethylene glycol and 2 moles of adipic acid had been produced (Desmophen 2001), 900.61 g of 1,4-butanediol, 0.5148 g of methanol, 2.154 g of trimethylolpropane (the amounts of monofunctional methanol and trifunctional trimethylolpropane are chosen so that an average functionality of 2 is achieved ), 0.04127 g of p-toluenesulfonic acid, 3.536 g of dibutyltin dilaurate and 3514.42 g of diphenylmethane-p, p'-dik isocyanate are added The solution is stirred for 21/2 hours at 49 ° C., the content of unreacted Isocyanate is determined by titration. An amount of 1,4-butanediol is then added which corresponds to an alcoholic hydroxyl group for each unreacted isocyanate group. The viscosity of the solution rises to 2450 P (Brookfield) after 6 hours, at which point 160 g a solution of 40 parts of methanol and 60 parts hurry DMF can be added to terminate the reaction. The viscosity of the solution obtained is 2100 P and the viscosity number is 1.115.

800 g of this polyurethane solution are mixed in 427 g of micropowder

009828/176 1

Sated sodium chloride (average particle diameter 10 μm, maximum particle size 52 μm) mixed in a mixer of 3.8 l with two mixing arms. After mixing for 65 minutes, the mixture is degassed at 4 mm Hg for about 30 minutes, spread between 3.25 mm thick pads on a porous support made of a sintered polyethylene sheet material treated with a surfactant "Duponol ME" was then immersed for 1 h in water von'20 ⁰ C and overnight in water at 57 ° C, dried, and stripped off from the carrier.

The oil material is heated in a convection oven according to Example 1, different temperatures being used below the temperature at which the material collapses (180 ⁰ O). The following results are obtained:

Heat treatment

no 168 ⁰ O, 174 ⁰ O 10 min 10 min Thickness (mm) 1.9 1.95 1.4 Shrinkage (% change): length -7 -6 broad -6 -6 Density (g / cm *) 0.40 0.52 0.68 % Change 0 30 % 70% Water vapor permeability (g / m ^2/24 h) 720 670 750 Tear strength (kg) 3.40 3.75 4.20

Flexural strength at -12 "0 (h)

24

48

0 0 9 8 2 S / '' ü

- 26 examples I 4

In this example, a slide is used for illustration, that of a microporous film of a structure according to FIG. 1 but a thickness considerably below that of preferred films had been made. Similar results were obtained with the thicker films.

The film was made from a polyester urethane having a molecular weight of about 60,000, the polyester urethane being made in accordance with U.S. Patent 2,871,218, column 4, lines 12-27. A mixture of 1447 g (1.704 mol) of hydroxyl-poly (tetramethylene adipate), molecular weight 849, hydroxyl number 130.4, acid number 0.89 and 109.6 g (1.218 mol) 1,4-butanediol is in a kettle with a volume of 4 liters melted and with a Spiralbandrührer about 20 min at a pressure of 5 to 6 mm stirred at 100 to 1to ⁰ C. 730 g (2.92 mol) of diphenylmethane-Pjp'-diiflocyanate are added to this mixture. The mixture is stirred for about 1 minute, and then poured into a lubricated container of 30 liters, which is immediately closed with a stopper. The "container" is placed in an oven at 140 ^° C. for 3.5 hours. The product is then cooled. A 20% strength solution of the polyester urethane obtained in tetrahydrofuran is prepared.

79.8 kg of this solution are heated to 62 ° 0 and up 62 to 73 ° G held while slowly 43.3 kg of 1-hexanol can be added. The solution is clear. The solution is then slowly cooled over 22 min until a temperature of 47 ° 0 Turbidity occurs. The cloudy solution is then cooled to 43 ° C. for a further 7 min and over a period of 3 min with a thickness of about 2.0 mm on the surface of a

009828/1761

196G266

^ air carrier, such as a percal fabric made of polyester and Cotton poured with a weight of 0.006 g / cm. The material is air-dried for 6 hours at increasing temperatures up to 120 ° 0 in order to remove the solvent and remove the non-solvent. After cooling down the microporous polyurethane film is peeled off the fabric made of polyester and cotton.

Regarding strength and other properties is the product is of poor quality, probably due to insufficient control of the conditions during the Cool down and when pouring.

The non-reinforced film obtained is then placed horizontally on a metal plate in a draft oven, in which dry, hot air of about 146 ° C is blown across it at a speed of about 100 cm / sec over a period of 5 minutes. at which the material collapses is 155 ° C. The film shrinks in length (in the machine direction "MD") by about 18% and in width (in the transverse direction "TD") by about 15%. The thickness remains at about 0 , 6 mm, measured with a gauge according to ASTM D1813-64. The measurement results are easily influenced by the different strengths of the material against compression, the thickness after the heat treatment being 0.61 mm compared to 0.58 mm before the heat treatment. The density determined by weighing a rectangular piece, measuring its length, width and thickness and calculating the volume on the basis of the measured dimensions is 0.479 g / cnr versus an original density of 0.557 g / cm, which means a density increase of 33%. The product characteristics' {chaften are listed below.

0M9.828 / 1761

196O266

With warmth
treatment According to thermal ASTM standard
treatment - 1.15 tensile strenght
(kg / cm.2) 1.25 MD 28.4 5 &, 5 D882 6? TD 29.5 60.0 Elongation at break (%) MD 250 560 " TD 247 250 Load at 25%
Elongation (kg / cm ^) MD 1.05 TD 1.00

Area under the force-strain curve
(kg, .cm / jcm ² )

MD
TD 2.89
2.99 7.5 *
7.54 π Tear resistance
(kg> MD
TD 0.4-5
0.54 1.25
1.10 D2212-64 Vapor permeability
(g / m.2 / 24 h) 850 855 E96-66

In a comparative experiment, the heat treatment was carried out in the same way, except that the layer of microporous polyurethane was not peeled off from the auxiliary carrier . Thus, the material placed in the furnace existed

0 09828/1761

made of a polyurethane layer that attaches to the cotton fabric impregnating the fabric with the polyurethane during of casting adhered. The presence of the cotton bottom layer prevented free shrinkage of the polyurethane top layer and the material curled up during the heat treatment.

Example 5

A microporous polyester polyurethane film approximately 0.75 thick and having a structure according to FIG. 1, which had been prepared according to Example 4 and then had been dyed with Irgacet BL-Black (trade mark) in methanol solution and had a density of about 0.4 g / car, was in an oven according to Example 1 for 4 minutes at 157 ° O heated. It was then found that the microporous structure of the film had collapsed and the surface of the material was translucent or translucent. Another sample of the slightly microporous material was heated for 4 minutes under the same conditions but at a lower temperature of 143 ° C. The density of the material increased and the area shrank accordingly. The bite resistance increased by 40 % and the film retained good water vapor permeability properties.

Example 6

A pigmented microporous polyurethane film of approx 1.8 mm thick with a density of 0.41 g / cm, which was produced according to the general method according to Example 1 was, is heated in an oven according to Example 5 for 4 minutes. There are two experiments, each with a fresh sample carried out. At the first attempt, the air temperature is

009828/1761

^{146 0} C in the oven and 157 ° C on the second attempt. The material thickness remains unchanged at about 1.8 mm, "but the density increases to about 0.44 g / cm ^ in the sample treated at 146 ° 0, that is by 7%. The elongation at break is considerably higher in the heat-treated samples than the original material *

Example 7

A microporous polyurethane film is made from polyurethane that has been polymerized in solution. A polyester with hydroxyl end groups with a molecular weight of about 2000 was prepared by reacting with 1,4-butanediol and a slight molar excess of diphenyl * -methane-pjp'-diisocyanate in pure DMP at about 50.degree. When the reaction is complete, further 1,4-butanediol is added, which reacts with the excess isocyanate. The reaction is stopped by adding a small amount of a mixture of methanol and DMF. The solution contains about 30 % solid resin. 800 g of the solution are mixed with 427 g of micropulverized sodium chloride with an average particle size of 10 μm and a maximum particle size of 52 μm in a kneader with two stirring arms of 3.8 liters capacity for 65 minutes and then for about 30 minutes at 4 mm Hg degassed. The solution is then spread out between discs of 3125 on a porous auxiliary carrier made of a sintered polyethylene film which had been treated with a surface-active agent "Duponol MS", in water at 20 ° C. for 1 h and then in 57 ° O water overnight immersed, dried and removed from the submount. The procedure corresponds to the procedure described in Example 3, but an amount of diisocyanate is used that the temperature at which the microporous structure collapses, if the film according to

009828/176 1

Example 1 is heated for 10 min in a convection oven, is about 191 ° C. \ -

The foil is then in a hot air oven according to Example 1 heated for different periods of time at different temperatures. The results are in the following Table listed.

Heat treatment:
Temperature ( ⁰ C)
Time (min) | no 163
5 180
* 10 25th 180
30th 180
60 185
10 Thickness (mm) 1.27 1.27 1.06 720 1.01 0.92 0.81 Change in thickness (%) 2.6 MD
TD -6
O -8.2
-3.6 8th -9.1
-4.1 -9.5
-4.5 -11.8
- 5.2 Density (κ / cflr) 0.44 0.46 0.55 The uneven shrinkage seems
Relieve stresses τη , which 0.57 0.57 0.74 Increase in density "(%) 0 30th 30th 68 What s vapor through
nonchalance
(g / m ^2/24 h) 730 720 750 680 620 Tear resistance
(kg) 2.6 2.7 2.9 3.5 4-1.3. Flexural strength at
-120 ° C (h) 4th 6th 12th 12th 4th on faulty
on the slide during '

during manufacture, e.g. during leaching. .

009828/1761

1960268

Example 8

In this example a microporous film is treated, which has been made by a process wherein a solution of a polyurethane is the leachable particle contains, poured onto an auxiliary carrier, the solvent evaporates and the leachable particles by a leaching, medium removed.

A solution of a thermoplastic elastomeric polyurethane is made as follows. To 39.5 kg of DMF in an Eeaktor with 76 liters of content, 855% of the in Example 3 named polyester (Desmophen 2001), 176? g 1,4-butanediol, 6.80 g of dibutyltin dilaurate and 6683 g of diphenylmethane-p, p'-diisocyanate admitted. The solution is stirred at 49 ° C. for 2 1/2 hours. The content of unreacted Isocyanate is determined by titration. Then enough 1,4-butanediol is added that an alcoholic Hydroxyl group on each unreacted isocyanate group is absent. The viscosity of the solution increases over 3.4 hours on 360 P (Brookfield). At this point, 305 g of a mixture of methanol and DMF in a ratio of 50:50 added to terminate the reaction. The viscosity of the solution obtained is 2,400 P, the viscosity number is 1.00.

A 30% solution of the polyurethane in dimethylformamide is made with particles of sodium chloride with an average particle size of 6 µm and a maximum particle size of 40 µm according to microscopic examination a kneading mixer with two stirring arms at tree temperature Mixed for 1 hour with exclusion of air. Then will the mixture passed through a three-roll mill, the Rollers are set so that the salt particles do not split

0 09828/1761

to ensure the even distribution of the salt in the mixture to improve. The milled mixture is then degassed in vacuo at 4 mm Hg for 30 minutes at room temperature. The degassed mixture is spread on a water-permeable auxiliary carrier made of a porous polyethylene "Porex" (trade name) consisted and immediately into one Brought hot air oven to slowly evaporate the solvent, with the treatment 10 h at oven temperature lasted from 38 0. Then the mixture is turned into a Brought a water bath to leach out the salt, which e.g. 9 1/2 hours at 57 ° C and then 1 1/2 hours at 4-3 ° C dried in a convection oven. The film obtained is stripped from the auxiliary carrier.

The same procedure is carried out with two different ratios of salt polymer, with the ratio 3.8: 1 a less dense foil material and with the ratio 1.8: 1 a denser foil material is obtained. rehearse of these poles, which coincide at 179 ° E then treated with heat under different conditions. The results are shown in the following table:

- 34 · -

009828/178 1

Salt: polymer ratio

. (a). 8: 1 (c) 3, Ca). 8: 1 174 Heat treatment no 0>) 174 no (e) 10 Temperature ( ⁰ C) 168 1-0 165 1.35- Time (min) 1.34 60 0.99 1.9 5 0.60 Thickness (mm) 0.49 1.14 0.74 0.27 1.9 122 Density (g / cnr) O 0.63 51 0 0.33 Density increase (%) 28 22nd 2.27 Tear-resistant 2.6 6.0 1.14 speed (kg) 3.9

Other measurements on the heat-treated sample e _t compared to the same measurements on the "treated sample d" show that the tensile strength and the elongation at break are about 170% of the values before the heat treatment. The modulus at 25 % elongation is about 130 % of the value before The area under the force-strain curve, which shows the work required to break the material under tensile load, is about 320 % of the value before the heat treatment.

According to a further embodiment of the invention, a method for producing a microporous polymer film material consists in ^{mixing a layer of a polymer solution in a hygroscopic organic solvent, e.g. N, N 1} -dimethylformamide, with microscopic, preferably hygroscopic, water-soluble filler particles, which are dispersed in the solution are and subsequent evaporation of the solvent in air at a temperature below 40 ° 0, preferably at 30 to AO ⁰ C and immersing the layer obtained in water for

0 0 9828/1761

Leaching of the filler.
Example 9

Another suitable polyurethane that can be used in place of the Polyurethane mentioned in the above examples can be used using polycaprolactone ("Max D56O") with an average molecular weight from 2029 instead of GK The polycaprolactone has alcoholic hydroxyl groups at both ends by initiating the polymerization of C-Gaprolactone in the presence of 1,4-butanediol were manufactured. The acid number of the product is 1 or less.

The auxiliary carrier used in the preceding examples usually consists of a sheet of porous synthetic plastic material, which is obtained by spreading a uniform layer of low-pressure, high-density polyethylene powder on a smooth metal surface and then placing the smooth metal surface with the layer in an oven heated to a suitable temperature for sintering the particles. The surface of the obtained sintered sheet material which has been in contact with the smooth metal surface is smoother than the other surface. The polyurethane layer is formed on the smoother surface. A typical sub-carrier has a thickness of 1.7 i 0.01 mm country has an air permeability 396-113 of air / minute at a static water pressure of 203 mm and weighs 12,25 g / m ^2.

In the above examples, the product of the heat treatment furnace is removed, placed flat on a metal table and leave to cool at room temperature of about 25 ° G to the air

009 828/1761

calmly. When working continuously, the The foil leaving the oven can be cooled quickly, e.g. by blowing air at room temperature. In the examples there is no external mechanical force on the foils during heat treatment or during cooling applied.

In terms of structure, the preferred type of mikrofe . Porous sheet material can be seen from the photomicrographs

2 to 4 that the volume of the foils is largely taken up by the cavities of generally rounded or compact but not very elongated shape, the maximum dimensions of the cavities being in the range of 10 to 45 μm, which are interconnected by smaller passages are connected. In each cross-section through these foils some cavities are cut through in a transverse plane so that their full diameter appears, while others are cut through on one or the other side of the transverse plane, so that the apparent diameter of such voids can be considerably lower on the Photografie than the actual diameter w.

The preferred thermoplastic elastomeric polyurethanes, which are tempered according to the invention, should be few or have no chemical crosslinking points at all. They are believed to get their properties in the first place Line of hydrogen bonds rather than crosslinks. The force-strain curves are the same general figure like the curves according to FIG. 1 in the article by Stetz and Smith in "Rubber Age", May 1965 »page While the polyurethane as such usually has a stress deformation below 100%, as already

0098 2 8/176 1

refines, the preferably used microporous polyurethane films generally recover completely without permanent deformation under normal dry conditions at room temperature.

The measurements given in the examples were carried out at room temperature (23 ° C) if nothing other is mentioned.

The water vapor permeability of a black calf chrome leather for men's shoes 1st quality, according to which in the

Measured in the methods mentioned in 2 examples, is 680 g / m / 24 h.

While the examples were done in air, are similar results obtainable when under a nitrogen atmosphere is being worked on.

PATENT CLAIMS

0 09828/176 1

Claims (16)

- 38 P ATENTANSP EU .CH E 1) J method for the treatment of microporous film material made from a thermoplastic elastomeric polymer which does not have any I-sheet material made of preformed fibers as a component and is approximately 0.63 "to 2.5 m thick, characterized in that the I-sheet material is at a temperature below the temperature at which the material collapses and loses its porous structure, but lies within 40 ^° C. of this temperature, can shrink by at least about 5% of the area. 2) Method according to claim 1, characterized in that g e k e η η draws that an area shrinkage of about 5 to 40% is allowed to take place. 3) Method according to claim 1 or 2, characterized in that the heating under Conditions carries out that during the heating Thickness of the film material essentially unchanged remain. . Λ) 'Method according to claim 1 or 2, characterized ge ken η ζ e i c h η e t that the heating is carried out under conditions that the thickness of the film material decreases during heating. 5) Method according to claim 4, characterized that one does not compress the sheet material during heating with a decrease in thickness. 0 09828/176 1 6) Method according to claim 1 to 5 j, characterized in that a film material is used as the starting material, the density of which is below about 0.5 g / cToP . 7) Method according to claim 6, characterized in that a film material is used as the starting material, the density of which is about 0.2 to 0.45 g / cm- ⁵ . 8) Method according to claim 1 to 7, characterized in that g e k e η η draws that one can use a film material as the starting material used, its elongation at break above 50%, its water permeability at least 200 g / m / 24 h ο. and the tensile strength of which is at least 5 kg / cm. 9) Method according to claim 1 to 8, characterized in that a microporous IOlienmaterial used as a starting material, the pores of which form compact cavities of about 20 to 45 / .mu.m before heating Maximum dimension is made possible by connections with smaller Diameter are connected. 10) procedural r s according to claim 1 to 9, characterized in that there is used as starting material is a polyurethane film material which has a yield strength at about 5 "to 20% elongation and has a breaking elongation of at least 300%. 11) Method according to claim 1 to 10, characterized in that g e k e η η, is characterized that you can use a polyurethane film material as the IOlienmaterial used, the polyurethane being the reaction product of (a) a soft polyester in which 0 09828/176 1 the groups 0 I! -C-O- by aliphatic chains with an average of 3 to 6 »“ Carbon atoms are separated one behind the other and the has a molecular weight of 800 to 6,000 and (Td) Diphenylmethane-pjp'-diisocyanate is the polyurethane is chain extended and thermoplastic and made in dimethylformamide remains soluble after heating. fe 12) Method according to claim 1 to 11, characterized in that one is on the film material applying a surface layer of molten polyurethane about 2 to -J5 / µm thick. 13) The method according to claim 1 to 12, characterized g e ken It is indicated that a microporous sheet material is made of a thermoplastic, elastomeric Polyurethane is used, mixed with 0 to 40% by weight of another thermoplastic, elastomeric polymer and that has a thickness of 0.63 t> is 2.5 mm. 14) Method according to claim 13? characterized geke η η - W is characterized by heating under conditions in which there is an increase in density of the film material between about 20 and 50%. ' 15) Method according to claim 1 to 14, characterized in that a microporous film material is used, which consists of a polymer solution in one hygroscopic organic solvent that contains microscopic water-soluble filler particles dispersed a layer from this solution, evaporation of the solvent 009828/1761 in air at a temperature of 4G ⁰ G or below and immersing the layer in water to leach the killant. 16) Use-the according to claim 1 "to 15 reimbursed Folxenmaterials for the manufacture of uppers of shoes as a leather substitute. 09828/176