DE2031340A1 - Porous sheet-like material - Google Patents

Description

Nonwoven fabrics can be produced by various processes, e.g. carding, garnetting, and beating in air or in water, spinning from the melt of one or more threads and making mats with irregular Arrangement of the fibers.

Such non-woven fabric-like fabrics are proportionate useless as long as the fibers are not connected to each other. This connection can be frictional, e.g. with needle felts, or the fibers can be bonded to one another by an adhesive.

To give the non-woven textile products a useful resistance to give against wear and tear and a good tensile strength, a considerable part of the fibers must be connected to one another » This stiffens the structure in such a way that the handle and other properties differ from those of the usual woven fabric or knitted textile products. A wide one Such nonwoven fabrics are widely used as substitutes for Woven or knitted fabrics not found - / -

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There are numerous substitutes for leather, for example be used as upper leather for shoes or as material for handbags. These substances are called substitutes for leather, because their surface is similar to that of leather and they are similar feel like leather. Such substitutes include, for example, expanded vinyl compound films. You feel but not quite like leather. Especially when kinking or

They feel like plastics when lying down.

The substitutes for leather from plastics consist of at least two layers. The backsheet is a relatively expensive nonwoven mat made from staple fibers. the other layers, usually the top layer, are a microporous film. These microporous films become common made from solutions or dispersions of a resin and a liquid non-resin forming material. If he doesn't Resin-forming substance is removed or if a solvent which does not dissolve the resin is added, the resin coagulates. After washing and drying, a microporous film is obtained. When coagulating, they are likely to melt together Particles of the resin obtained. Elastomeric polyurethanes are now used for this. The surface layer can also be with the non-woven to the backing layer are directly connected,

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if you put the mentioned solution or dispersion on the surface applies, then coagulates, washes and dries · Man can also apply the solution or dispersion to a woven base and then coagulate, whereupon the surface layer is connected to the base by means of an adhesive. This usually involves soaking the non-woven layer Mat especially with a resin, so that the fibers with each other * - The mat can also be sewn through to increase its density and strength. Likewise, the density of the nonwoven mat can be enlarged by shrinking.

The formation of microporous films is very difficult to carry out, because for this one has to apply a liquid resin to a solid surface, whereupon the coagulation, washing out and drying follows. The final product obtained, i.e. the dry one microporous film, often contains depressions, small holes, has a surface like orange peel, has an uneven surface Thick, streaked on the surface and may have other bad qualities. You must therefore be particularly careful when making them.

There are other methods of making leather substitutes as well. These are also laminates,

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whose surface layer is relatively thin and looks like leather on the outside. These surface layers are made by incorporating a soluble salt into a Layer made of a polymer. The salt is then leached out so that there are gaps in the layer. if If sufficient amounts of salt are used, this layer can be permeable to air. But such layers are difficult to produce if you want to work continuously in order to produce a consistent product of good quality »In all Cases, however, this surface layer is not uniform

Another method described in the literature consists in mixing two immiscible polymers and pulling this mixture out of a mouthpiece into fibers. Then these fibers are disintegrated in water and overlapped on a sieve to form a thin film »One of the polymers is then dissolved out using a solvent * This solvent usually contains a salt that is soluble in water. Here, one of the polymers is decomposed in such a way that an adhesive is formed which connects the remaining fiber components to one another to form a sheet of plastic. None of the polymers is removed, so that the end product obtained contains considerable amounts of the adhesive, which is lost when the polymer dissolves

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Evaporation of the solvent and, if necessary, washing out the soluble salt is said to form a porous film. This film has a rough surface. In order to remove the roughness, the surface must then be heated be treated. This reduces the porosity of the film and gives it the appearance of a plastic. The film is relatively thin and should feel like leather. This claim is not true because it is not taken into account is that leather for footwear rarely has a thickness of less than 0.5 mm. Thicker films can be do not produce continuously and evenly according to the method described. The thin film thus obtained must So be applied to another carrier so that he can has the desired thickness for leather substitutes.

In the case of the known laminates used as a substitute for leather, the layers separate from one another so that the Product cannot be bent · In the usual bending tests in the leather industry, these substitutes have proven to be proven worse than good quality leather. The layered structure of leather is probably the reason for it Superiority.

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There are also processes for the manufacture of substitutes for Leather from needle felts described. These products have a rough surface that is only with great difficulty and Cost can be processed so that it has the appearance and properties of leather «This is about Fabrics with a layered structure, which are also sold nowadays, but cannot be seen as a substitute for leather- · nen.

The seams in needle felts, at which the staple fibers are connected to one another, form dense areas within the mat. The other areas are considerably less dense. As a result, the products produced in this way are poor and bend irregularly. There will be a large number of seams or a significant amount of glue is required to reduce this effect. More common when bending such The imperfections can be easily identified using needle felts. A needle felt is therefore not homogeneous and has a non-uniform one Density. Of course, when sewing evenly, a uniform and approximately uniformly dense structure can be obtained; When you wear it, however, the leather will not cover your entire surface worn out, but only at individual points. If there are irregularities in leather substitutes, there are areas where they are most likely to break.

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The invention relates to a porous sheet material of non-woven fibers and a process for its manufacture. This material can be used for different Purposes are used, e.g. for handbags, dialytic membranes, separators in batteries, textile products and synthetic leather · The material according to the invention feels like woven or knitted products, has the feel of such and on the other hand feels like leather. He therefore does not serve only as a substitute for leather but can be called synthetic leather be considered. This synthetic leather is microporous. The pores cannot be seen with the naked eye, but rather with the help of a microscope, as you can even with a microscope see the pores in the polished surface of leather can.

The material according to the invention is characterized in that it consists of ultra-fine, thermally deformable, molecular-oriented fibers which are connected to one another by fusing at their points of contact, have pores that are open, interconnected and extend from surface to surface and have a denier of less than have about 0.5. Preferably the fibers are less than about 5 microns in diameter.

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The type of fibers depends on what the product is for should be used «The density of the sheet, its thickness, the thickness and length of the fibers, the tensile strength and all other properties have an influence on the properties of the end product

The modulus of tensile strength is determined according to ASTM D-638 at an elongation of 1 % of the polymer used to make the ultrafine fibers.

A "predominant part" means that at least 50% by weight of the substance in question are present · A "lower proportion" means a smaller amount · The amounts given relate to on the total weight of the substances in question in the sheet-shaped end product β.

In the following description and claims, who> ° 'the non-extractable or residual ultrafine fibers and extractable ultrafine © fibers mentioned Extractable ultrafine fibers are those that can be removed from the structure and not sin.d included in the final _e Wicht "extractable or residual ultrafine fibers are those which are contained in the end product according to the invention «-.

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The process according to the invention consists of the following process steps;

(a) was extruded a mixture of non-miscible with each other, deformable in the heat polymer into a shaped body under stretching. Here at least one of the polymers is converted into extractable fibers and at least one of the other polymers is converted into the form of non-extractable fibers. Such a process is described in US Pat. No. 3,099,067.

(b) The ** xtrudate is processed into a sheet-shaped body, ZtB. by converting to each slurry and forming one Sheet from the slurry · One such process is in U.S. Patent No. 3,097,991. One can also interweave the extrudate, apply by air, overlapping superimpose and the like.

(c) The sheet obtained in step (b) heated so high that at least some of the ultra-fine fibers contained in it fuse together.

(d) At least part of the extractables are extracted ultrafine fibers from the sheet, making it porous and

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becomes permeable to the vapor of moisture ·. _; .

By "melting" or "fusing" are meant those working conditions in which two individual fibers of the same Composition and the warmth on the surface combine with each other «A connection on individual items is sufficient Dots, merging along the entire length is not required, although this can also happen.

The invention relates to a porous sheet made of fibers and a method for its manufacture. The majority of the fibers in the sheet are ultrafine and have a denier of less than 0.5 ♦ preferably a diameter of less than about 5 microns »Preferred are ultrafine fibers with a diameter of 0.1 to about 2.5 microns» In a preferred embodiment of the invention, a portion of the fibers contained in the sheet typically has at least 5% by weight, a tensile modulus of less than about 175O kg / cm. These fibers are fused together in the sheet. These types of ultrafine fibers can be present in the sheet up to an amount of 100 % of the total amount. Preferably, however, at least 10 % to 100 % of the fibers consist of those with one

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ο Modulus of tensile strength below about 1750 kg / cm »The proportion on these latter fibers influenced to a large extent the usability of the end product.

Ultrafine fibers with a modulus of tensile strength at about 1750 kg / cm are referred to as hard ultra fine fibers "" soft ultrafine fibers ¹ · designated ultrafine fibers having a higher modulus of tensile strength. As will be referred to as "designated. When the soft ulirafeinen fibers of elastomeric materials consist and the sheet contains at least 50 % of such soft ultrafine fibers, the end product has properties that enable its use as synthetic leather, if the content of soft elastomeric fibers is less than about 20 % with the remainder being hard ultrafine fibers, e.g. with a modulus of tensile strength over 700 kg / cm, the end product can be processed into textiles or handbags, depending on the type of ultrafine fibers. The thinner the end product, the sooner it can be used in the textile industry. The diameter of the ultrafine fibers also has an impact on how the final product is calibrated feels, that is, what its grip is like. Since the different components of the end product are essential for the intended use, different ones can be used

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Uses are mentioned, e.g. as synthetic Leather, for textile goods, rigid structures for bags, separators in batteries, filters and the like. Those differences are known to every person skilled in the art.

As already mentioned above, in process step (a) the ultrafine fibers formed.

There are two types of soft fibers according to the invention, viz elastomeric soft ultrafine fibers and non-elastomeric soft ultrafine fibers. The elastomeric ultrafine fibers are made made of a polymer with a modulus of tensile strength below about 700 kg / cm at 25 C. The modulus of the tensile strength is

2 2

preferably over 7 kg / cm, in particular over 17 »5 kg / cm.

ο A tensile strength of at least 3 »5 kg / cm is desirable,

2 in particular of at least 14 kg / cm. Have the best fabrics

a tensile strength of at least about kO kg / cm. In the isolated state, the elastomeric ultrafine fibers can be stretched by at least 100% of their length, with a restoration of at least about 50% to the original length of at least about 50% taking place after the tension is released at room temperature of 25 ° C. In addition, the elastomeric ultrafine fibers can be stretched at least 25% at room temperature.

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That is what makes these ultra-fine elastomeric fibers The polymer used is deformable under heat and can form extremely thin fibers with diameters under 5 microns Pressure and application of heat are withdrawn.

Thermoplastic fibers alone can be used to produce these fibers Polymers can be used, but one can optionally also use those polymers which, because of a partial crosslinking, are not completely thermoplastic, but are can be processed into ultra-fine fibers *

The non-elastomeric soft ultrafine fibers are also used made of a thermally deformable polymer.

Such polymers have a tensile strength modulus of less than

p O

Less than about 1750 kg / cm, usually over 350 kg / cm · Since these ultra-fine soft fibers do not have the rubber-like properties of elastomeric soft ultra-fine fibers, they do not regain their original length if after being stretched by 100 % during The train is lifted for 10 minutes at room temperature. Although these fibers are soft, they are nevertheless somewhat harder and stiffer than the ultra-fine fibers made from elastomeric materials.

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Hard, ultra-fine fibers consist of one that has been exposed to heat. malleable "polymer with a modulus of tensile strength about

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about 1750 kg / cm, preferably above about 3500 kg / cm «die

other properties, especially the dissimilarity with Rubbers are the same as above for the soft non-elastomers ultrafine fibers are described.

The raw materials also include other components, but these are not critical in production. These include, for example Fillers, pigments, dyes, plasticizers and the like. In the following they are referred to as "inert ingredients" designated.

The non-elastomeric soft polymers according to the invention, The soft non-elastomeric ultra-fine fibers from which the soft non-elastomeric ultra-fine fibers are made include low-density polyethylene, resinous Polyethylene oxides, polyvinyl acetates, partially hydrolyzed Polyvinyl acetates, non-elastomeric copolymers of ethylene and acrylic acid, non-elastomeric copolymers of ethylene and alkyl acrylates such as ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate and the like, adducts of maleic anhydride with pyrolyzed polyethylene, polypropylene, copolymers of Ethylene and propylene, polyepsiloncaprolactone, all aliphatic Polyester and polycarbonate and the like «

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Examples of elastomeric polymers for making the soft elastomeric ultrafine fibers are elastomeric polyurethanes, polyamides, polyesters, polycarbonates, polyalkyl acrylates, copolymers of ethylene and ethyl acrylate which can be saponified with alkalis, and the like.

Suitable elastomeric polyurethanes are the segmented ones Polymers of soft, low-temperature melting, hydroxyl-terminated polymers, which through Urethane bonds are interconnected to form rigid urethynes, polyamides, and polyurea compounds that melt at high temperatures and / or polyesters that have terminal isocyanate groups or groups with polyisocyanates react such as hydroxyl groups, amino groups, mercapto groups and the like.

The best urethanes that can be used typically contain at least one, preferably at least two, recurring polyether radicals, i.e. a polymeric radical, the recurring Ether bonds, for example -C-O-C-, with the carbon atoms adjacent to the oxygen in the inner Chain structure are saturated »and / or at least one, preferably at least two recurring polyester radicals, i.e., polymeric units with repeating ester bonds

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- 16 of the formula O

It

The polyether and polyester residues preferably have a molecular weight of at least about 500 and no more than about 7000. They are connected to the rest of the polymer by urethanyl

Bonds of formula

OR

Il I

connected, where R is a hydrogen atom or an organic Radical such as an alkyl radical having 1 to 8 carbon atoms Cycloalkyl radical with 5 to 8 carbon atoms, a phenyl radical or a benzyl radical. The urethany! Binding is connected with one carbon atom of the organic residue of an organoscale Diisozyanats, which in turn has the nitrogen atom an amide bond of the formula

RO

-N-C- ■, -i ■ -: i <3 -

of a residue that is not an active hydrogen atom contains, e.g., with the remainder of an organic diol, one Polyamine compound or an amine compound that has a urea bond the formula

0 ti

- IMH-C-NH -

forms. The polyether and polyester residues can also be urethane

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contain nyl bonds of the type described above in their chain. Such radicals preferably have a melting point below 150 C, preferably below 6O C,

The polyester radical can be formed by reacting a dicarboxylic acid with an organic diol or by condensation polymerization an alpha-omega-hydroxycarboxylic acid or an alpha-omega-lactone. Preferably the terminal ones are Hydroxyl radicals of this polyester blocked so that they are bonded to non-carbonylic carbon atoms. then these polyesters, when they have the desired molecular weight, are reacted with an organic diisocyanate. Preferably at least two moles of the diisocyanate are used per 1 mole of the polyester. A diisocyanatic prepolymer is formed with blocked end groups. Then you put the prepolymer with a chain extender, such as a diol or a Dithiol, a diamine or with water, with an essentially linear / solvent-soluble polyurethane is produced. One method for making these noted polyurethanes is described in U.S. Patent No. 3,097,192. Chain extenders include, for example, hydrazine, At hy lend lain in, 1,! - Propylenediamine, 1, Tl-Hutandiamine, 1,6-Hexamethy lend i «min, 1, 't-piperazine, ethylene glycol, 1,2-propylene glycol, 1, 'i-Hutnn <l LoI, ethanolamine, diethanolamine, urea,

Dimethylolurea and the like.

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Other suitable polyesters can be obtained by conversions of epsiloncaprolactone and / or alkyl-substituted epsiloncaprolactone with an active hydrogen containing Initiator, such as water, ethylene glycol, ethylene diamine, diethylene glycol, Dipropylene glycol or 1,2-propylene glycol. Such Methods are described in U.S. Patent Nos. 3,169,9-5, No. 3,186,971, and JMr. 3,427.3 ^ 6.

The polyesters with terminal hydroxyl groups and a molecular weight from 500 to 7OOO can then with an organic Diisocyanate are reacted, as a prepolymer, a polyurethane with a molecular weight of about 1000 to about 10,000 is created. The terminal isocyanate groups of this Polyurethanes can be blocked for direct reaction with the chain extender. Also terminal hydroxyl groups can be blocked, and the prepolymer can additionally be reacted with a diisocyanate, as is described in the US patent No. 3,186,971.

Other useful polyurethanes are described in U.S. Patent No. 2,871,218. The polyester-polyurethanes according to this patent are obtained by admixing a polyester blocked at the hydroxylic end groups,

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is obtained by reacting 1,4-butanediol with adipic acid to Diphynylmethan-p, p'-diisocyanate and 1,4-butanediol
in essentially stoichiometric proportions
The polyester should have a molecular weight of about 800 to
1200 have. For each mole of polyester, about 1.1 to 3.1 moles of the diisocyanate and about 0.1 to 2.1 moles of the butanediol are used. By increasing the molar proportion of the diisocyanate, the melting point and the hardness of the polyurethane obtained can be increased. By reducing the molar part of the diisocyanate, the melting point and the hardness of the polyurethane can be reduced «

The polyethers can be used in essentially the same manner
are characterized as the polyesters · They have roughly the same melting points, roughly the same molecular weight and
their hydroxylic end groups are blocked · They are formed by alkaline or acidic condensation of alkylene oxide. Such polyethers and their use in manufacture
of polyurethanes are described in U.S. Patents No. 2,813,776, No. 2,818,4o4, No. 2,929,800, No. 2,929,803, No. 2,929 * 8o4, No. 2,948,707, No. 3, 18o, 853 and No. 24,691.

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Suitable elastomeric polycarbonates include segmented polymers of soft, low-temperature melting polymers with multiple hydroxylic end groups, which are connected by carbonate bonds with rigid, high-temperature melting polymers multicarbonates.

elastomeric polycarbonates are described in Canadian Patent No. 668,153 (particularly Examples 2 and 3), U.S. Patent No. 3,030,335 (particularly Example 2 and Column 1, lines 56 to 68), in US Patent No. 3, 16l, 6l5 (especially Examples 3, 7, 10, 14, 15, 19, 20, 21, 22, 24 and 25) in U.S. Patent No. 3,2O7,814 (in particular Examples 1, 2, 5, 7 »9» 10 and 11), U.S. Patent No. 3,287,442 (particularly Examples 9, 10, 11, 13, 16, 18, 21, 23, 29 and JO). The above mentioned Patents also describe the processes and starting materials for the production of such elastomeric polycarbonates, which can be used according to the invention »

Elastomeric polyesters suitable according to the invention are described in U.S. Patent No. 2,623,031 (particularly examples 1, 2, 3, 4, 5 and 6) in U.S. Patent No. 3,023,192 (particularly all examples) in the U.S. Patent No. 3,037,960 (especially all examples) »Here

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they are also elastomeric segmented copolymers in which a soft section is connected to a hard section by an ester bond. The hard one
Section is a polyester while the soft section
a polyester or a polyether, as described above at
the description of the elastomeric polyurethanes is described.

Suitable elastonic polyalkyl acrylates include
Polyethyl acrylate, copolymers of ethyl acrylate and others
Alkyl acrylates such as n-butyl acrylate, 2-ethylhexyl acrylate and
like that. They also include copolymers of ethylene
Alkyl acrylates such as ethyl acrylate, which can be saponified with alkalis such as sodium hydroxide and / or potassium hydroxide,
being useful terpolymers of ethylene, alkyl acrylate and
Acrylic acid is formed. To other copolymers of this class
include copolymers of ethylene with acrylic acid and / or alkyl acrylates such as 2-ethylhexyl acrylate and the like.

Elastomeric polyamides suitable according to the invention are described in U.S. Patent Nos. 2,929,001 and 3, 0-9, 909.

The hard ultra-fine fibers are obtained from in the heat deformable polymers, such as high-density polyethylene, polypropylene, poly-1-uuten, polystyrene, poly-alpha-methyl

■ - / - ■■

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styrene, poly-alpha-chlorostyrene, copolymers of vinyl chloride and vinyl acetate, partially hydrolyzed copolymers of vinyl chloride and vinyl acetate, polyvinylpyrrolidone, copolymers of N-vinylpyrrolidone and vinyl acetate, copolymers of vinyl methyl ketone and vinyl chloride, vinyl acetate or N-vinylpyrrolidone, methacrylate, methacrylate! diethyl acetal of polyacrolein, copolymers of styrene and acrylonitrile, nylon such as polyhexamethylene adipate, Polytetramethylensebacamid, f poly-epsilon-caprolactam, polypyrrolidone, the Polyimidazoline, polyester such as polyethylene terephthalate ₈ poly-1,4-Cyclohexylenter terephthalate and the like, and Q3cymetb.ylenh9rpolym.ere Copolymers, ie the polymers of formaldehyde, polycarbonates such as the reaction products of phosgene or monomeric carbonate asters with bis-phenol A / 72-bis (4-hydroxyphenyl) propaneJ7 and the like, polyarylene polyethers according to US Pat. No. 3,264,536 and the like.

k The method according to the invention is used in the following Steps carried out.

Method step (a) i

Two or more thermally deformable polymers are mixed, melted and extruded into monofilaments, multiple filaments, rods, tapes or films, the extrudate being either stretching during or after extrusion. As

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already said, the extrudate contains at least one extractable and at least one non-extractable fiber. These fibers arise from the extrusion and stretching of a mixture of polymers which are immiscible with one another, i.e. that they are neither in a molten state nor in a solid state with one another are compatible. Typically, each of these polymers has a molecular weight greater than 10,000. For mixing them together Conventional methods and apparatus can be used to avoid incompatible polymers prior to extrusion. if the polymers as starting materials in powder form, as pellets or are in granular form of approximately the same dimensions, they can be in a dry state, e.g. in a cone-shaped Mixer or in a ribbon mixer. If but the particle sizes are too different, these methods of mixing are insufficient. In this case you can be in the heat work. For example, the polymers can be mixed on a two-wheel chair or in a Banbury mixer process at elevated temperatures. Another method is that you all the starting materials in a suitable common solvent or solvent mixture dissolves and the solvent or solvents then removed by evaporation. Another method that is particularly applicable when the polymers are at temperatures close to their melting point not be degraded, is the so-called double

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Extrusion · Here, the polymers are extruded in the usual way as a melt, then pelletized or chopped and mixed in the dry state prior to extrusion to form the moldings.

The particle sizes of the incompatible polymers in a dry mixture only affects the dimensions of the fibers in the end product if the mixture is in the molten state before being extruded through a mouthpiece or a slit and is mechanically processed with little acid two incompatible polymers in a heated cylinder with a piston that pushes the melt through a narrow mouthpiece without the mass being mechanically processed, the dimensions of the fibers in the extrudate can be regulated by choosing particles of the appropriate diameter in the dry Mixture, whereby must be taken into account in certain ψ stretching or pulling out. the diameter of the fibers and the particle size! " the starting materials.

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During normal work, however, the ultrafine fibers described above are created · During this work, somewhere during during extrusion, the mutually incompatible polymers are converted into a plastic state to such an extent that the particle sizes of the starting materials are not decisive for the dimensions of the fibers in the final product. Little work is required and the effect of one is enough Screw in a conventional extruder, also the processing of a particulate mixture of polymers in the heat on a two-roll mill or in a Banbury blender in front of the Extrusion is sufficient even if extruders are used in which no mechanical processing takes place, e.g. a Cylinder and a piston.

The working conditions during extrusion, in particular the temperature, can within a relatively wide range be changed. These conditions' depend on the physical and chemical properties of the extruded polymers »They can also be used with the same compositions of Experts can change · The mixture of each other not Compatible polymers must, however, be so fluid or soft in the extruder that when the extrudate is harvested, a uniform reduction of its diameter takes place «The extruded mixture has upon exit from the mouthpiece

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a fibrous structure, and drawing or stretching ensures that. Formation of ultra-fine fibers. This pulling out can also take place in the extruder itself, if it is built for this purpose _a

The fibers in the extrudate can be formed by drawing out or stretching in the heat or in the cold. »Each of these processes leads to special properties of the ultrafeix fibers contained in the end product . When pulling in the heat of the diameter of the Eactrudates and thus the diameter of the individual fibers is reduced "After the extraction of the melt in the heat of substantially di © fibers in the final product, no or only low molecular eisis Orientation ± n Lätigsrichfcung.

The nature of the work in the heat or the cutting of the two or more incompatible granulated polymers influences the diameter of the ultrafeisisn Fasora when it emerges from the mouthpiece of the extruder "Der Untarachied"'' between the diameter of the bore of the extruder and dam üurshaiaea © ** de »Mouthpiece © of the Sefalitses vsruraaelit a certain weight loss of the sneaser, which is also the case with extruders

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the same design may change depending on the Mouthpiece · Know the melt and the extrusion conditions is fixed for a given mixture of polymers, a single determination of the fiber dimensions is sufficient for, given working conditions, to establish approximately the amount of draw required to produce fibers of the desired Diameter is required. If you have ideal properties of the individual ultrafine fibers in the extrudate, i.e. the shape of uniform rods with a preferably circular cross-section, and if you then further the extrudate pulls out so that the fibers are pulled out by the same corresponding amount, the diameter is one Fiber after drawing is equal to the diameter before drawing divided by the square root of the ratio the new length to the old length

The extrudate can, if required, also in the cold stretched to achieve molecular orientation of the fibers · This cold stretching is best done immediately performed after hot undressing, or you can it can also be carried out at any time later, even after the extrudate has been stored.

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The cold stretching is primarily used to achieve a molecular orientation of the ultrafine fibers in the longitudinal direction. This orientation by stretching is well known in the manufacture of synthetic fibers. This improves physical properties such as tensile strength and, in some cases, also improves heat aging. The stretching of the extrudate is carried out in the same way as previously known. The degree of orientation in the individual fibers depends on the type of polymer used and on the intended use of the end product. Thanks to the dependence of the diameter on the length of the ultrafine fibers before and after drawing, cold drawing with an elongation of several 100 % causes a molecular orientation, but does not change the diameter of the ultrafine fibers significantly, even if this was previously caused by the Heat pull down is reduced to about 0.125 microns.

Preferably, W is stretched, the melt of the immiscible polymer during or after the extruding at least 1OO% to obtain a final product gutverwendbares · This extraction causes a corresponding verrin .gerung the diameter or thickness of the extrudate. Pulling out can be achieved through the shape of the opening

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of the extruder or by pulling the extrudate as it exits from the opening at great speed.

As noted, the extruded molded body contains numerous ultrafine fibers. This is regardless of whether the extrudate is in the form of a single thread, multiple threads, one Films or the like. For example, an extruded Rod with a square cross-section with an edge length of about 2.5 cm contain 1,000,000 or more of such fibers, which are parallel to the pull axis of the rod.

Process stage (b): '

As is described, for example, in the US patent specification No. 3,097,991, the shaped body obtained after process step (a) can easily be converted into a slurry. In this prior publication, only one shaped body in the form of a single thread is described, but several threads or films can also be cut into strips and treated in the same way. They are maintained in the usual way to form a slurry from which a felt can easily be made. Here, the ultrafine fibers of the extrudate are first converted into a slurry. If you process a film, a tape or a rod, · ο these are initially at certain intervals

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split open and then cut to specific lengths. Man
then place them in water where the slurry forms.

Single threads and multiple threads become certain quantities
cut up, depending on the extent of whipping or refining. The cut extrudates with
the ultra-fine fibers should have a length of no more than about 30 cm f "preferably not more than about 20 cm, most have of not less than 1.5 Now, when you made into the slurry. The thickness and width of the shaped bodies from which the slurry is made should be no more than about 12.5 mm, preferably no more than about 6 mm. The slurry is nothing more than a dispersion of the cut and / or split shaped body.

The slurry is then treated so that a
fc fibrillation takes place. The pieces are treated mechanically so that they break and split up, the fiber bundle of the original pieces being divided into smaller bundles and into individual fibers. When fibrillation
extremely small bundles of ultra-fine fibers or
individual ultra-fine fibers that break off the surface of this
small bundles are split off as fibrils. For this purpose, the usual methods of whipping or refined

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BATH ORIGINAL

■ ■ .- 3.1 ■ -

reti von Papier, «an works for example in a Dutchman, a Hydrapulper, a Vortex whipper, a Sharplepulper, a Dynopulper, a Jordan refiner, a Bauerraff ineur, a curlator refiner.

Whipping or refining is important and affects some significant properties of the final product. When the length of the ultrafine fibers or the fiber bundles when it is opened is not greatly reduced and if the length of the fibers is more than about 12.5 mm, the inventive End product has a great tensile strength, but in some cases other properties, such as the porosi_ did and the grip worsened. When you hit or refining can also be done in the presence of smaller amounts of common staple fibers such as cotton, nylon, polyester, acrylic fibers, Modacrylic fibers and the like work to increase the wear resistance and tensile strength of the end product to improve. However, these additional fibers do not in themselves contribute to achieving the structure of the end product according to the invention.

You can even partially whip a given slurry and refine them and then add them to a slurry combine with another composition, e.g. a composition

1098 13/1775

pulp slurry for papermaking or with another partially whipped or refined Slurry of other ultrafine fibers. In this manner mixtures of different fibers can be obtained in a simple manner. In some cases changes are made to the Making a pulp with fibers of different lengths is of significant advantage in making different end products.

Typically, whipping and refining reduces the length of the extruded shapes to less than about 2.5 cm, typically less than about 12.5 ^mm, and typically to lengths between about 0.8 and 10 mm. The slurry obtained in this way can now be used for the production of the felt sheet after process step (b). Here you can work in a known manner by hand or with a machine.

If desired, the slurry or pulp can also contain other way, e.g. in a ball mill with water or by finely grinding the parts and then Immersing the fragments with fibrils protruding from their surface in water. The sheets from these

109813/1775

slurries can either be made by hand in the usual way if you put the slurry on a sieve brings, squeezes the mass until a filter cake is formed, removes more water by suction and then the whole thing heated to remove the rest of the water. The best way to make such sheets is by machine e.g. on an Eourdrinier paper machine. Here you can The usual processes known from the manufacture of paper are used to produce very good uniform cohesion Fily. Sheets to be obtained afterwards according to the procedure step (c) are treated.

As already said, the pulp can contain ultrafine fibers from different formic or ρ er η, which are obtained in process step (a). The slurry may therefore contain different fibers, and / or the Puple can also ZelluloHßfasern or other fibers such as cotton, polyester .Nylon _t, contain Acryiverbindungen and Modacrylverbindungen. These slurries can be formed in the first stages, for example before or during the placing in the head cheese in a Fourdrinier machine. A person skilled in the art can easily make numerous changes here.

H) 9 Β 1 3 /! 7 7 Γ »

BATH ORIGINAL

- 3k -.

The matted sheet obtained in this way with the ultra-fine fibers is now ready for process step (c).

Instead of forming a pulp, forming a sludge and felting, other methods can of course be used. This includes laying in the air Staple fibers, the crosswise overlapping laying of strips, Films or tapes of the incompatible polymers by hand or by means of machines for formation a mat or a fabric, or the weaving of ribbons or strips into a fabric. These products are also then ready for process step (c).

Process step (c):

The dry sheet obtained in step (b) is then heated so high that at least some of the non-extractable ultrafine fibers in the sheet melt or soften. The temperature used for this is one that under the pressure used the non-extractable ultrafine Fibers soften enough to fuse together with bonding and to bind all of the fibers in the sheet together connect to. It is desirable, but not necessary, to also place the oxidizable ultrafine fibers in the sheet with one another too merged. As a rule, the softening

10 9 8 5 13/177 _BAD

temperature of non-extractable ultra-fine fibers higher than the softening temperature of the extractable ultrafine fibers, so that the latter also with each other upon heating merge.

In an advantageous embodiment of the invention Procedure when heating is a pressure on the surfaces of the sheet exercised. The temperature during pressing should be at least as high as the softening temperature of the non-extractable ultrafine fibers to be bonded together, i.e. the softening temperature of the Fibers at normal temperature and pressure. -

As already said, the temperature should be such that the majority of the non-extractable ultrafine fibers in the sheet melt together.

This process step can be carried out in a platen press with the plates at the desired temperature be heated. One can also use the sheet that is used in the process step (b) is obtained, perform between pairs of heated rollers, or it can be carried around a large roller under pressure around by means of an endless conveyor belt, whereby the Conveyor belt comprises at least part of the circumference of the roller.

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This latter process is carried out in a Rotocure apparatus used for curing rubber will. Suitable apparatus for heating and applying pressure are for example in US Pat. No. 2,971,218 described. Optionally, the sheet can also be dielectric be heated.

Usually a pressure of at least 1.5 to 2 kg / cm is used. The pressure should be sufficient to reduce the thickness of the sheet by at least 5 % . This compression is permanent because the sheet does not regain its original thickness when the pressure is released and cooled to room temperature. When the ultrafine fibers are oriented by drawing, little shrinkage is usually observed during the heat treatment under pressure. The sheet can shrink in length or in width or in thickness or in two or more of these directions »

Process step (d);

In this process step, the microporosity and the Air permeability achieved. The sheet treated according to process step (c) is preferably introduced into Bath of a liquid that is a solvent for the extractable tiltrafine fibers, but the non-extractable ones.

109S13 / 177S

does not substantially dissolve ultrafine fibers in the sheet. Choosing a suitable solvent is important in producing the desired end product »The solvent should make the extractable ultrafine fibers lightly
dissolve and should not attack the non-extractable ultrafine fibers at all if possible. If usual
Staple fibers are incorporated into the blait, the solvent should not dissolve these staple fibers. It is essential that practically all extractable ultrafine fibers are removed from the sheet, so that it subsequently contains practically no such fibers. The formation of resinous non-fibrous material within the sheet should be avoided
will. The loosened fibers should therefore be removed practically completely. A sheet-shaped one is obtained here
End product with the desired porosity and / or air permeability. In this way, a sheet with a uniform porosity is also obtained.

To do this, the sheet is immersed in the bath of the solvent. This bath should contain practically no liquid that is a solvent for the non-extractable
Fibers is. However, liquids can also be present that are neither extractable nor non-extractable
Loosen fibers in order to reduce the rate of dissolution

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gel. Other methods can be used instead of immersion use, e.g. spraying the leaf with a solvent until the extraction is complete ». After the extraction The leaf is then dried at the lowest possible temperature in order to remove practically all traces of the solvent. Desirably this dry temperature is below the Softening temperature of the non-extractable ultrafine Fibers.

Typically, the volume of solvent used is greater than the volume of the extractable fibers. Preferably a substantial excess of the solvent is used. You can also use several successive baths for extraction to achieve maximum extraction of the extractable fibers. The leaf so depleted has after. Drying the desired properties of porosity, des Grip, feels wanted and the like.

Before or during process step (d), the sheet embossed in the heat with a heated embossing roller to apply figures to one or both of the surfaces. Embossing can also be done after extraction. It should be noted, however, that some the pores of the surface here compressed or you

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- 39 diameter is reduced so that the porosity decreases *

In addition, one or both surfaces of the obtained The sheet can be polished or cleaned so that the surfaces have certain properties that the end product for make it suitable for the intended purpose without affecting the porosity.

One of the most important properties of leather is impermeability for liquids with simultaneous permeability of moisture vapor. This quality is important for the upper leather of shoes.

The erfinduii _o sgemäße synthetic leather has the same characteristics. It also has the flexibility, feel and other properties of leather,

The permeability for the vapor of moisture is

2 measure by the amount of moisture in grams per meter each Hour passed through the sheet under the following conditions:

a circular disc of a leaf of certain surface area is attached to a mug at its edge with wax, containing excess amounts of a desiccant, such as

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Calcium chloride contains. The beaker is kept in an atmosphere of 21 ° C. and 65 % relative humidity for 16 hours, after which the beaker with the film is weighed.

After the first weighing, the beaker is left in the same atmosphere for another hour and weighed again « This process is repeated until a constant

Permeability to moisture vapor measured in grams

2
per meter per hour is reached. The final liert is called MVT. The MVT value of good calfskin is between about 15 and about 60 and higher, usually between about 20 and about 25 * The most widespread substitute for leather is called "Corfam" by the company E ₀ I ₉ du Pont de Nemours & Co · distributed. This leather substitute has MVT values between 15 and about 35 h ± s 40, which also depends on the embossing and treatment of the surface »

Synthetic leather should also be able to withstand bends, have a good grip, feel good, and be easy to work with be to have good abrasion resistance and good tensile strength »Some of these properties can only be can be determined by the subjective judgment of experts »The synthetic leather according to the invention corresponds to - all these prerequisites and also has hinsiclitlieli the physical properties different advantages over ©

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the products on the market today.

An important property of the synthetic according to the invention Leather is extremely homogeneous because it is uniform Made from a non-woven base material will be produced. A pad for the inventive Synthetic leather is not required in many cases because it is exceptionally good physical Has properties. In some cases it may be desirable to connect it to an underlay, e.g. a woven one or non-woven fabric to give it the stability you want admit.

The surface of the synthetic leather according to the invention is very uniform, which is a consequence of the method used is. In many cases it is not necessary to treat the surfaces with a lacquer or a latex, whatever is required for the usual substitutes for leather. The surface of the synthetic leather can be embossed to give it a grainy appearance, such as the appearance of crocodile leather, calf leather and snake leather, the surface can also be brushed in the usual way so that it looks like Swedish leather.

- k2 - *

Had the majority of the fused ultra-fine fibers in the sheet is made of elastomeric soft ultrafine fibers · The remaining fibers may or soft ultrafine fibers be · Preferably, the sheet of at least 6O weight "-% elastomarer soft ultrafine fibers, in particular at least 75% of such . In a particularly preferred embodiment of the invention, hard ultrafine fibers are present in amounts of not more than 10% by weight. For most uses, the best product is a sheet in which 100 % of the fibers are soft, ultra-fine fibers. Up to 25% by weight of these soft, ultra-fine fibers can consist of a non-elastomeric material. Preferably, however, all ultrafine fibers should consist of an elastomeric soft material »

In the production of such a sheet, after process step (a), a shaped body is formed in which the The amount of elastomeric soft ultrafine fibers is not significantly greater than the amount of non-elastomeric soft or hard fibers ultrafine fibers.

Preferably, the amount of these elastomeric ultrafine fibers is not greater than the amount of non-elastomeric soft ones or hard ultrafine fibers. The volume content of elastomer

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Its soft ultrafine fibers can go down to 20 % of the volume of non-elastomeric hard or soft ultrafine fibers. In a particularly good embodiment, the volume content of elastomeric soft ultrafine fibers is between 40 and 98 % of the volume content of non-elastomeric hard or soft ultrafine fibers.

The sheet is then processed according to the process steps described (a) to (d). When performing the process step (c) the temperature for bonding between the fibers should be at least the grazing temperature of the elastomeric soft ultrafine fibers. It is very desirable that the non-elastomeric hard or ^ oak ultrafine fibers Er "· i.; hung temperature s that are below the softening temperatures of elastomers soft ultra-fine fibers. When performing of method step (c) should preferably be a Pressure can be applied to the surface of the sheet to reduce its thickness

A high concentration of elastomeric ultrafine fibers is important and significant for the production of good synthetic leather. When non-elastomeric ultrafine fibers are present in too large quantities, the properties

1Ö98137177S

BATH ORIGINAL

adversely affect the end product »

In this regard, synthetic leather is an important one Embodiment of the invention. Typically it has one greater thickness than the usual makes. In many cases a thickness over 0.25 »preferably over 0.5 mm. In most Cases a thickness of 2.5 mm is not achieved. This substantial Thickness is an important property of the end product. The presence of greater amounts of elastomeric ultrafine Fibers make a major contribution to this.

End products of this type differ markedly from synthetic leather in some respects. Not woven Manufactures do not require the use of elastomeric ultrafine fibers, although these can be used if desired can be. That in process steps (c) and (d) treated sheet need not consist only of ultra-fine fibers, as is usually the case with synthetic leather. The sheet can also contain common staple fibers »The end product after process step (d) is porous, but does not need to be microporous like synthetic leather. Used in the manufacture of synthetic leather in process step (b) a pulp in which the ultrafine fibers are broken up to an approximately uniform length

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are. However, it can also be beneficial to use a pulp that contains ultra-fine fibers of various lengths from 0.2 to 25 mm »

Synthetic leather shouldn't be board-like in most cases. However, if desired and for certain uses, some nonwoven end products can be board-like. In other cases, very soft and pliable nonwoven products that cannot be used as a leather substitute can be useful for certain other purposes _{or the like}

When assessing non-woven fabrics, the Handle important · There are important subjective standard requirements here. The differences between a soft and a stiff handle are imprecise * this difference is ab- ' depending on the modulus of the polymer used to produce the ultrafine fibers, on the cross-section of the ultrafine Fibers, the apparent density of the porous sheet and the shape of the ultrafine fibers. In a non-porous, fully compressed structure, where no individual ultra-fine fibers can be recognized, the soft feel decreases, if that used for hearing sharing the ultrafine fibers

ο polymer has a modulus of tensile strength above about 700 kg / cm

'■■■ - / -

109813/1775

B ^r '-D ORiQfNAL

Has. If the density of the sheet is reduced in process step (d), a softer feel is achieved, even if the modulus of the tensile strength of the polymer of the ultra-fine fibers is 3500 kg / cm ο if the sheet is thin _; is, the modulus of the tensile strength to achieve a soft grip can also be greater than 3500 kg / cm and, for example, 3500 ° kg / cm. The more porous or less dense the sheet, the higher the modulus of tensile strength of the polymer can be in order to obtain an end product with a soft hand. It can thus be seen that there are several important variables in the manufacture of final nonwoven products in accordance with the invention. This is a great advantage since, because of the larger number of variables, a person skilled in the art can more easily achieve the desired properties.

In the manufacture of nonwoven fabrics , it is desirable that the sheet contain no more than 10% by weight, preferably no more than 25% by weight, of staple fibers. The use of staple fibers increases the abrasion resistance and tensile strength, but a disadvantage d ri handle. Another and very welcome option is to use two different slurries in process step (b), each of which is made from a product from process step (a), but one with pulp containing fibers

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a length of no more than about 12.5 mm and the other Slurry longer fibers, no more than about 25 mm Length, contains. These pulps can be used in various proportions depending on the characteristics of the desired End product are mixed together * The term "fiber length" denotes the mean fiber length. Man Can be used as ultrafine fibers of various lengths to improve either the abrasion resistance or the tensile strength of the To influence the end product. As the density of the sheet increases, so does tensile strength and abrasion resistance to, but the grip deteriorates, if not then care is taken that the modulus of the tensile strength of the

2

sern and about 3500 kg / cm, preferably below 1750 kg / cm, especially below? üO. Leaves of higher density from soltihen Fibers with a low modulus of tensile strength do not differ significantly in terms of their grip. ,

Also important for the manufacture of non-woven fabrics Scrolling is the fact that process step (c), where merging takes place, also without the use of Pressure can be carried out on the surfaces of the sheet can. In some cases, especially when a textile-like appearance is desired, it is important while heating not to put pressure on the surfaces of the leaf.

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As I said, pulp is not necessary to get the sheet you want. You can, for example, the extruded molded body, preferably in Form of threads, split films, ribbons or strips, weave into a product that after fusing and extracting the desired porous end product. You can also cut single filaments or multi-filament extrudates of immiscible polymers into staple fibers, which with With the help of air it can be blown into a felt, which is then fused and extracted into a porous end product can be. One-way oriented films made of immiscible polymers can cross over one another can be arranged, for example, by winding on a core or a cross-wound bobbin. Here, too, a sheet is created that can be processed into the porous end product by melting and extraction. You can also use toothed needles Sew such sheets together or lay one or more such films on top of each other in order to mix the fibril bundles to reach. A desired end product can also be obtained from this by melting and extraction.

As used herein, the term "nonwoven fabrics" relates not just on synthetic leather. The expression is supposed to

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generally refer to a fabric-like textile product, that is used where customary, woven or knitted Makes are used.

Although the moldings can be made into one by weaving or knitting Can unite sheet, the fused and extracted final product cannot be regarded as a woven or knitted fabric will. When fusing, the woven or knitted structure is destroyed. The essential cohesiveness of the fused Leaf is the cohesion between the mutually compatible Fibrils. After extracting the extractables With ultrafine fibers or fibrils, the porous end product has a structure that a woven or knitted fabric has little or no structure is equivalent to.

A stiff and board-like structure can be achieved by selecting a hard non-extractable fiber by itself or in admixture with soft non-extractable fibers or by producing a relatively dense structure with a low MVT value from any fibers. The methods mentioned above can be used for this purpose. The density can be regulated, for example, by reducing the proportion of extractable fibers or by reducing the amount extracted. Conversely, practically all extractable fibers can also be removed from the sheet, the density being controlled

109813/1775 " ^A.

2ÖI134Ö

- 50 - ■ "*

by the proportion of such fibers in the sheet before extraction or by subsequent hot compression of the porous sheet to permanently reduce its density.

These end products have good structural stability and can be used as separators in separators for Batteries, as insulation material, as building material, for baskets and the same.

The following examples describe some embodiments of the invention without limiting it.

First, some elastomeric thermoplastic polyurethanes will be described, their use in the below the following examples.

Polyurethane A.

730 g (g, 75 equivalents) of polycaprolactone diol, hereinafter referred to as "polyol", are placed in a 2000 ml side reaction bottle with a heating mantle, a stirrer, a thermometer, an ebulator and a vacuum inlet tube "ΗίβΝΗ The polyol has a molecular weight of 2000 and is formed by reacting epsilon caprolactone with diethylene glycol. The polyol is heated to 100 ° C and degassed at this

1098 13/1775 " ^Λ

_ 51 -

this temperature for 1 hour under a pressure of about 2.5mm of mercury to remove moisture and dissolved gases. 565 g of bis ^ -Isocyanatophenyl) methane are in similarly melted and degassed at 50C. The temperature of the polyol is then increased to 149 C. The vacuum is interrupted and the heated and degassed polyol is poured

ο *
into a cylindrical steel mold heated to 177 ° C. 16: 9 g (3 »75 equivalents) of 1,4-butanediol are added to the polyol with stirring, whereupon the 565 g of bis- (4-isocyanatophenyl) methane are added. After the addition of the latter, the mixture is stirred for 1 minute and cured in an air oven at 177 ° C. for 1 hour. The thermally deformable elastomeric polyurethane obtained is granulated.

Polyurethane B.

This elastomer is produced in the same way as polyurethane A. with the exception that the equivalent proportions from bis- (4-isocyanatophenyl) methane to polyol to 1,4-butanediol at 5slj4 instead of 6: 1: 5. The quantities and Equivalents are the following,

. Weight equivalents

(G)

Polyol 730 0.75

1,4-butanediol 135.3 3.00

Bis (4-isocyanatophenyl) methane

■■ '.' ■ 471.6 3.75

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The polyurethanes A. and B made as described above have the following physical properties

stocks.

Table ^I AB

50 45 165 85 335 225 345 380 305 360 51 k5 51 55 37 47

Shore hardness D modulus 100 % kg / cm ²

Modulus 300 % kg / cm ²

I 2

w tensile strength kg / cm

final elongation %

ο C-wear kg / cm

B-Compression % Lasting Resistance %

Polyurethane G,

This polyurethane is an elastomer that is probably formed by the reaction of one of the hydroxylic end groups blocked polyethylene adipate with a molecular weight over 700 and probably under 2000, with bis (4-isocyanatophenyl) methane and 1,4-butanediol. This polyurethane is sold under the trade name "ESTANE 5701 resin" by B.F.Goodrich Chemical Company. "It has the following physical properties?

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Specific granted Hardness, durometer A Durometer G tensile strength (kg / em

Modulus at an elongation of 3GO % (kg / cm)

Elongation {%)

, 3

Graves wear (kg / cm) (approx.) Embrittlement temperature {C) Freezing point according to Gehman (C)

Abrasion according to Taber (loss in »ng) (CS17 wheel, 1000 g weight, 5000 cycles)

Stick temperature (C)

value ASTM-No .: 1.20 D12-27 88 D-676 60

5 170

B ~ k

91 D-624 500 D-746 25th D-1053 -62 -35

Polyurethane D.

This polyurethane is an elastomer that is likely to be created by reacting a blocked at the terminal hydroxyl polyethylene adipate with a molecular weight over 700 and probably under 2000 with bis- (4-isocyanatophenyl) ■ Methane and 1,4-uutanediol. This polyurethane is used under the Trade name "ESTANE 57 ^ 0 χ O7O resin" from the company U.F. Goodrich Chemical Company. It has the following physical properties:

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value ASTM No .: 1, 20 D12-27 95 D676 70 48 405 D-412 245 450 49 D-624 <-73 D-746 -18 D-1053 11 D-395-5-5

Specific weight hardness, durometer A durometer C

Durometer D Tensile Strength (kg / cm) (Min.)

Modulus at an elongation of 300 % (kg / cm2) elongation (%) (min.) Wear according to Grave (kg / cm) Embrittlement temperature (C) Freezing point according to Gehman (C)

Compression according to method A * 22 hours (ä 70 ⁰ C

Abrasion according to Taber (loss in mg) (CS17-Rad ₅ 1000 g weight

5OOO cycles)

Stick temperature (° C) 175 -

* According to method A, a constant compression pressure is achieved

exercised at constant temperature.

example 1

1200 g of polyurethane D, 400 g of a polypropylene resin suitable for the production of films and fibers with a: melt index of 2 to k and a density of 0.88 and 2 * t00 g of atactic crystalline clear polystyrene with a molecular weight of

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■ - 55 -

50,000 were mixed. The resins were in slices from etvra 3 mm in front. The three resins were mixed in a drum. The mixture was in an extruder with a diameter of about 32 mm and a single screw conveyor melted at 180 ° C.

The extruded strand was cut into pellets about 3 mm. These pellets were mixed, remelted and extruded from the same extruder into a strand of & wa 1.5 "" n diameter. A Godet device pulled the strand out of the extruder at a rate of about 3 meters per minute. The strand was then placed in a glycerine drawing bath kept at 125.degree. There the strand was drawn out at a speed of about Jk m per minute. This gave the strand a molecular Orieiüß- tion 110-10 X 100% = a 1000% strength by stretch orientation.

The strand was cut into pieces 12.5 mm to 15 cm in length. These pieces were now opened in a device according to Noble and Wood with a distance of the cutting edges of 0.125. This resulted in a completely dissolved pulp of the individual threads of the polymer.

The pulp was then post-processed on a laboratory device Noble and Wood made a sheet of 30 x 30 cm with a thickness processed by 5 mm.

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The sheet-shaped felt was dried in an air oven at 70 ° C. After drying, the felt was treated with a

A pressure of 7 kg / cm was compressed in a platen press, a sheet with a thickness of 3 now being produced. This The leaves were placed in a beaker containing toluene to extract the polystyrene. After the extraction, the leaf was dried to form a semi-finished leather-like end product. The sheet was about 4/10 of its true density, one Porosity similar to that of leather with an MVT of I5 and mechanical properties similar to those of leather. It left flexed excellently and had good abrasion resistance. It had the crush resistance and feel of leather.

Example 2

The procedure of Example 1 was repeated with the exception that 1000 g of polyurethane D with 1000 g of atactic crystalline clear polystyrene were mixed. The pellets of about 3 <nm were melted and formed into a strand about 1.5 mm in diameter extruded, whereupon this pulled out with a device according to Godet at a speed of about 3 ni per minute became. In a stretching bath made of glycerine, the strand was at 125 ° C. at a speed of about 75 m per minute stretched. The molecular orientation is expressed by

the formula 25O - 25 X 100 % ~ 9OO%. The strand then turned 25

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cut into pieces with lengths of 6 to about 100 mm and in a Noble and Wood impact device with leaf spacings pitched by about 0.175 mm »This resulted in a pulp of mixed polymers

The pulp was processed in a device according to Noble and Wood to a sheet of 30 × 30 cm with a thickness of 2.5.

The sheet-shaped felt was dried in an air oven at 65 ° C. After drying, it was at 170 C with a pressure compressed by about 2 kg / cm in a platen press, wherein it was given a thickness of 1.5 rom. Then they brought the sheet into a beaker with toluene to extract the polystyrene. After extracting, the leaf was dried and had the Semi-processed leather appearance. The apparent density is rf about half the true density, the porosity is that comparable to calfskin, the leaf had an MVT value of lö and mechanical properties similar to those of Leather. When buckled, it had excellent durability and good abrasion resistance. It had the turning properties and the handle of leather,

10981 3/1775

Example 3

Example 1 was repeated with the exception that * 100 g 'polystyrene according to Example 2, 800 polyurethane' D and 200 g polypropylene according to Example were mixed. The mixed pellets were melted and extruded in an extruder according to Example 1 at 200 ° C. m was pulled out per minute. They led the strand by a stretching bath of 130 C and pulled in _Rait: a speed of 30 m per minute from. this gave an orientation of 900%. The strand into pieces of. cut about 2.5 to about 75 cm and opened in a Noble and Wood device with knife spacings of 0.15 mm.

The pulp thus obtained was made into a sheet of felt 30 30 cm thick in a Noble and Wood apparatus of 1.25 mm processed.

The felt was dried in an air oven at 50.degree. C. After drying, it was pressed together at 170.degree. C. with a pressure of 3.5 kg / cm, a sheet with a thickness of 0.625 mm being formed. The polystyrene was extracted in a beaker with toluene. After the extraction, the leaf was dried and

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had the appearance of semi-worked leather. The sheet had about half of its theoretical density, one porosity similar to that of calfskin, an MVT of 30 and mechanical Properties similar to those of leather · Otherwise behaved it is like the end product according to Example 3

example k

The "procedure of Example 3 is repeated with the exception that 600 g of polyurethane D-, I56 polyurethane C, 2kk g of polypropylene

and 1000 polystyrene were used. The four resins were mixed in the form of discs of about 6 mm in a drum. The mixture was melted in an extruder at 175 ° C. The extruded strand was processed into disks and melted again and drawn out in the form of a strand with a diameter of about 0.8 mm at a speed of about 7 "1 / 2minute with a device according to Godet. The strand was then placed in a drawing bath Glycerol at 125 ° C. and stretched it at a speed of about 70 m per minute. A molecular orientation of 1000 % was achieved. The strand was cut and opened in a device according to Woble and Wood with knife intervals of 0.175 mm.

1098 13/1775

- 6ü -

The pulp became a sheet of 30 x 30 cm with a thickness of about 0.9 mm processed in a device according to Noble and Wood.

The obtained felt sheet was placed in an oven in air at 25 ° G dried. After drying it was at 17O C under a

Pressure of 7 kg / cm compressed to a thickness of 0.45 mm. The polystyrene was then extracted with toluene in a beaker. Subsequently, the sheet was dried. It had about the Half of its true density, a porosity equal to that of glove leather or a dense fabric and mechanical properties similar to those of leather it had the properties given in Example 2.

Example 5

The procedure of Example 4 was repeated with the exception that 1000 polystyrene and 1000 polyurethane A were used. The mixture was at 195 C in an extruder with an internal 30mm diameter and a single screw conveyor melted. The extruded strand was cut into disks as described above. These pellets again became one Strand with a diameter of 0.8 mm drawn out at a speed of about 6 m per minute. Then you stretched in

109813/1775

; -61 - ■■■ '.

a glycerine bath at 125 C at a rate of 27 ra per minute, a stretching of 370 % was achieved for molecular orientation. This strand was pitched in a Noble and Wood device with knife spacings of 0.15. \

The pulp was made into a paper felt of 30 x 30 cm with a thickness of 0.43 mm on a device according to Noble and Wood.

processed.

It was dried at 75 C ⁱⁿ air in an oven. After drying, the felt was pressed together at 190 C under a pressure of 3.5 kg / cm in a platen press so that it had a thickness of 0.18 mm. The polystyrene was then extracted with toluene. Extraction was followed by drying. The sheet had about half its theoretical density, was well porous, had an MVT value of 51 and had mechanical properties between those of glove leather and a dense fabric. The other properties were the same as described in the previous examples.

Example 6

500 g of polystyrene according to Example 2 and 500 g of polyurethane B were mixed * The pellets of about 3 ^mm were placed in a drum

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mixes. The equipment was melted in an extruder with an internal diameter of 30 mm at 220.degree. C. and extruded. The extruded strand was cut into pellets of 3 ^mm , mixed and re-extruded into a strand with a diameter of O.8 mm. The strand was drawn out of the extruder at a speed of 6 m per minute. Then it was stretched in a glycerine bath at 130 ° C. at a speed of 30 m per minute, so that the 400% 1-ge stretching resulted in a molecular orientation . The stretched strand was cut into pieces from 6 mm in length to 15 cm in length and opened in a device according to Noble and Wood with measuring distances of 0.15 mm.

The pulp became in a Noble and Wood device a felt-like sheet of 30 30 cm with a thickness of 3 | 2 mm manufactured.

It was dried in an oven in air at 75 ° C. and then pressed

ο 2

at 190 C with a pressure of 3 «5 kg / cm to a thickness of 1.5 mm. The polystyrene was stripped with toluene. When dry, the sheet had the appearance of a semi-machined Leather. Ee had about half its theoretical density and a porosity and mechanical properties similar to those of leather were comparable. Besides, it had the properties of the end products according to the previous examples *

10 9 8 13/1775 * - / -

Example 7

The procedure of Example 2 was repeated with the exception that 1000 polystyrene, 333 g polypropylene according to Example 4 and 666 g polyurethane D were used. The strand of the re-extruded pellets with a diameter of about 0.8 mm was drawn out at a speed of 6 m per minute. It was stretched in a stretching bath made of glycerine at a speed of 75 m per minute, so that a molecular orientation was achieved by stretching 1150 % . After cutting, the strand was then opened in a device according to Noble and Wood with knife spacings of 0.2.

The pulp became a felt sheet of 30 30 cm with a Processed thickness of 5 mm.

It was dried in an oven in air at ^^ C, whereupon the sheet was pressed together at 165 ° C under a pressure of 10 kg / cm to a thickness of 3 »2 mm. The polystyrene was then extracted with toluene. Extraction was followed by drying. The end product, similar to semi-worked leather, had a density of about half the theoretical density, a porosity like that of leather and otherwise the same properties as the end products obtained according to the preceding examples. '.

109813/1775 " ^A.

Example 8

The procedure of Example 7 was repeated except that 756 g of polyurethane D, 244 g of polypropylene and 1000 g of polystyrene were used. The strand extruded with a diameter of 0.4 mm was drawn out at a speed of 10 m per minute. In a stretching of glycerol of the strand at 13O C at a rate of 100 was m per minute stretched so that the molecular orientation achieved by a w 1000% ± ^ <s stretching wurde4 the chopped strand was mixed with in a device according to Noble and Wood Knife distances of about 0.125 tnm and processed into a pulp.

A felt sheet of 30 × 30 cm with a Thickness of 3i3 mm made.

The sheet was dried in air at 6ºC and in an oven then pressed together at 170 ° C and a pressure of 3> 5 kg / cm. The polystyrene was extracted with toluene. The final product had the properties described in the previous example.

Example 9

The procedure of Example 8 was repeated with the exception that 1000 g of polyvinyl acetate, 667 g of polyurethane D and 333 g

10 9 813/1775

Polypropylene were used. From an extruder with a single screw conveyor, the molten mixture was extruded at 170 ° C into a strand with a diameter of 0.8 mm and pulled out at a speed of 8 m per minute. The strand was stretched at a speed of 80 m per minute in a stretching bath made of glycerine at 120 ° C. so that a molecular orientation was achieved by a 900% stretch. Otherwise the procedure became the previous one Examples repeated, the polyvinyl acetate being extracted with toluene.

Example K)

The ■. Example 6 was repeated with the exception that a mixture au «pellets of 3 mm through a mouthpiece with several Orifices were extruded to form a yarn of 20 monofilaments, each monofilament being 1 denier of 0.5. The yarn was oriented by stretching.

The yarn was woven with 120 x 120 wefts. The 30 × 30 cm sample was pressed together at 190 ° C. in a plate press with a pressure of 31 ¹ J kg / cm, so that a sheet with a thickness of about 0.05 mm was obtained. The polystyrene was then removed by extraction with toluene, the procedure of Example (> being repeated. A soft, very porous sheet with good strength and considerable elasticity was obtained.

109813/1775 " ^A.

Example 11

The procedure of Example <"> was repeated with the exception that a felt of 3 »2 mm thick was made, which at 19O ° C was compressed to a sheet 1.5 mm thick.

The table below shows the characteristics of this Sheet.

1098 13/177 5

thickness
(mm) density
(g / cm ³ ) Tensile strength elongation
^speed ₂ %
(kg / cm) 93 5 %
Tangent
Modulus
(k _lC ; / cm2) Abrasion
lb / in. MVT Bally
Flexo
meter
Cycles Satra
Flex Synthetic
Leather after
Example 11 1.5 0.530 52 36 171 216 l8 ⁽² > '1.6 MM > 8 MM Corfam (Dupont) 1.6 >
0.500 84 23 164 125 19th 100 M. Agtran (Goodrich) ¹ ■ »5: 0.580 97 44 147 183 17th 50 M. 1 MM Calfskin vertical
to the backbone 1.3 0.630 I89 I61 216 28 > 1 ₅ 6 MM ^ 8 MM

oj calfskin parallel

_iTo the backbone to

1.3

0.630

265

280

347 2.8 ■. > 1.6 MM) 8 MM

-j (.l) 75 % relative humidity at

cn · ■ ■ ''. . ■.

(2) unprocessed »the surface is not coated

1.6 MM and 8 MM mean 1.6 million and 8 million, respectively 100 M and 50 M mean 100,000 and 50

2031140

Example 12

The procedure of Example 1 was repeated by combining equal parts by weight of polypropylene and polystyrene without the addition of polyurethane D. The pulp made from polypropylene and polystyrene fibers was made into a sheet with a size of 30 × 30 cm processed with a thickness of 0.38 mm. After pressing in the Warm, extraction with toluene and drying left a 0.125 mm thick porous nonwoven sheet of polypropylene fibers received · This sheet can be used to make separators in batteries and baskets.

Example 13

The procedure of Example 12 was repeated with equal amounts by weight of polypropylene and polycaprolactan with one Molecular weight of 40,000. It became a 0.05 mm thick porous nylon sheet obtained after extraction with toluene, which after hot pressing had a thickness of 0.25 mm. That nonwoven product had a good grip and can be used for Manufacture of outer clothing can be used.

ORIGlfslAL INSPECTED

9 8 1 3/1 7 7 5

Claims (10)

Pat ent test Porous sheet-like material, thereby g e k e η η show that he is made of ultrafine, in the Consists of warm, deformable, molecularly oriented fibers, which are connected to one another by fusing at their points of contact, open to one another, to one another connected pores extending from surface to surface and have a denier of less than about 0.5. 2. Material according to claim 1, characterized in that g e k e η η-z eic h η e t that the fibers have a diameter of we less than about 0.5 microns. 3. Material according to claim 1 or 2, d a d u r c h g ek e η η ζ e i c h η e t that the predominant © share of the Fibers consists of an elastomeric material. h "material, that all the fibers consist nfich J claim ₁ dadurchgeke η η- χ eic Ii et π from an elastomeric material. 5 * A material according to any one of claims 1 to h _t '1 ABy ge mark · / eic et h'n in that the fibers consist of an elastomeric polyurethane .. 109 813/177 6 0RJ3INAL INSPECTED 6. Material according to one of claims 1 to 5 »thereby characterized as having a thickness of at least 0.5 µm and being microporous. 7. A method for producing a material according to one of the Claims 1 to 6 * characterized in that that he ^ (a) under stretching a mixture of mutually immiscible, heat-deformable polymers into one Extruded molded body containing ultrafine fibers, (b) the molding processed into a sheet, (c) the sheet is heated to such an extent that at least some of the fibers formed in process step (a) are interconnected merges, (d) extracting at least a portion of the ultrafine fibers. 8. The method according to claim 7 »d a d u r c h g e k e η n- ^ draws that the starting material is a mixture of extractable and non-extractable polymers used· 9. The method according to claim 8, characterized by using a mixture that has a contains a predominant proportion of extractable polymers. 10 9 8 13/1775 ORIGINAL WSPPCTED 10. The method according to any one of claims 7 to 9, characterized geke η η ζ eic h η et that the surface of the sheet is kept under pressure during process step (c). 109813/1775 ORSGiNALlHSPECTED