CS197075B1 - Method of simultaneously manufacturing at least two types of flexible webs - Google Patents

Description

The invention relates to a process for the simultaneous production of at least two kinds of flexible sheet materials comprising a porous polymer layer prepared by precipitation of a polymer solution layer.

The materials are suitable for use in the shoe, clothing, haberdashery, upholstery and other technical applications.

With respect to the construction, I present essentially two types:

1. Laminated materials composed of a porous polymer layer and a backing textile layer; comprising an additional textile formation as a reinforcing interlayer.

2. Self-supporting, all-polymorphic poromeric materials.

In addition to the qualitative classification according to the design, the sheet materials are also assessed according to the external appearance.

Mostly synthetic leather, like natural leather, is produced with a smooth face, eventually leather. with a face, which imitates some kinds of natural skins (beef or veal box, seam, reptile, etc.).

The second group includes materials with special pile character of the surface, referred to as valur, nubuck, suede and the like.

197 075

Synthetic skins and hygienic properties have a wide range of applications and their properties vary according to use.

The basic and common part of all types of poromeric synthetic skins with hygienic properties is a polymer porous layer, characterized in particular by its ability to pass gases and water vapor.

These porous layers are prepared from polymeric substances or polymers. from a mixture of polymeric substances (in the form of solutions, dispersions) such as rubbers, polyamide, polypeptides, polyvinyl chloride, polyacrylates, polyvinyl acetate and others, or mixtures thereof. Particular preference is given to polyurethanes or polyurethanes of the polyether or polyester type, preferably linear or slightly branched, respectively. mixtures of these polyurethanes with modifying additives of other polymers or copolymers, for example polyvinyl chloride, with inorganic or organic additives, which affect the course of the process or the like; regulate the formation and character of the porous structure.

Porous structures of polymeric materials are formed by various chemical, mechanical or physico-chemical processes.

Particularly important are the physicochemical processes for forming porous structures from polymeric substances. They are based on the coagulation by the dispersion effect of electrolytes or, in the case of thermosensitive dispersions, by the effect of heat, in particular the coagulation of solutions of polymeric substances in polar solvents such as dimethylformamide, dimethylsulfoxide or tetrahydrofuran by the action of non-solvents. The thickness of the microporous facing layer for multilayer poromerics is between 0.2 - 0.7 mm.

The nature of the porous structure formed by the coagulation of the solutions, in particular the size and pore size distribution, depends on the precipitation conditions. For flat materials with a smooth or tread surface, porous structures with relatively smaller pores are prepared; their average size is in the range of 0.5 - 30 µm, preferably 1 - 20 µm.

The technological process of controlled creation of the porous structure is very sensitive and in order to achieve the required quality it is necessary to maintain the specified technological conditions relatively precisely.

For velor or suede materials, porous structures with relatively larger pores are formed and may have a diameter of 100-300 µm. Since it is possible to settle for a wider pore size distribution, it is not so important to maintain technological conditions.

The principle of preparing a porous synthetic material with a velor or suede character generally is to first form a porous structure with a larger pore size by known methods and then to undergo a final mechanical treatment, eg splitting or grinding, to expose the porous a structure that is similar to velor or suede from natural leather.

The technology for producing microporous layers by precipitation of solutions of suitable polymeric substances is complicated and relatively complex. Production conditions, especially for coagulation, are unique to the character of the microporous structure and must be carefully observed during manufacture. Also

107075 devices for scrubbing precipitated formations are usually designed and implemented for a certain thickness and working speed. For this reason, the production facilities are essentially dedicated. The manufacturing process of poromeric sheet materials laminated, irrespective of the quality of the textile substrate, may be varied in whether it is a direct application of a polymer solution to a textile substrate or an indirect - reverse method where the polymer solution is applied to a temporary substrate.

Thus, the tachological process of producing a given type of planar poromeric material has virtually no degree of freedom for a possible change of sortimet. The implementation of a wider range of poromerics for various areas of exploitation is thus limited and the innovation of production at a given production facility is problematic.

The present invention solves the possibility and the method for the simultaneous production of a wide range of sheet porometric materials, ie laminated sheet materials on various suitable substrates and / or self-supporting all-polymer type, in different thicknesses with smooth, embossed and / or velor, suede or nubuck.

The principle of the process according to the invention is that a self-supporting porous film or porous layer having a density of 0.2 - 0.9 g / cm ^-1 and a total thickness of 0.5 - 10 mm on a fibrous support is prepared by precipitation and the precipitated formation is mechanically separated by at least for two layers with thicknesses of 0.1 - 2 mm, which are bonded to the fiber backing layer or used as a self-supporting material.

Layers of different pore sizes and thicknesses may be embedded in the precipitated polymeric film. Thus, after the film has been divided into thinner layers, it is possible to obtain sheet materials having different properties, for example by bonding with different fibrous substrates, by blowing layers with larger pores onto the velor surface and the like.

In practice, according to the invention, a polymeric porous film of greater thickness is produced first, the thickness of this formation depends on the thicknesses required for the separate layers so that the polymeric porous film is used with minimal waste. It is advantageous to level the thickness of the polymeric porous film before mechanical separation into individual thin layers. It is best to carry out the equalization by the effect of heat and pressure on a calender with two rolls, at least one of which is metal with the possibility of heating. It is also possible to uniformize the thickness by grinding one or both surfaces. This makes it possible to obtain a velor or suede surface before mechanical separation into thinner layers.

The separation of the polymeric microporous film of greater thickness into individual layers is carried out, for example, on splitting machines of known construction. One layer is separated by passing through the splitting machine, the thicknesses of the subsequently separated microporous layers may be the same or different, depending on the type of poromeric sheet produced.

Substrates for the laminated porometric sheet materials are prepared separately. Here, for example, non-woven textile layers impregnated with polymeric binders can be used, which are subsequently converted into microporous form by coagulation.

197 07S

Further, it can be, for example, woven multi-warp satin or other weaves which can be combed and also impregnated with suitable polymeric binders in the form of solutions in polar solvents or in the form of dispersions.

In addition to textile materials, it is also possible to use natural leather as the substrate.

Another manufacturing process is the bonding of the polymer microporous formation and the selected substrate formation. For layered materials, the thickness of the microporous formation should be in the range of 0.1 - 1 mm, preferably 0.2 - 0.7 mm, depending on the advised quality of the final material.

Polyurethanes of a linear, but preferably crosslinkable, polyester or polyether type, adhesives based on natural and synthetic rubbers, copolymers and acrylate polymers in the form of solutions or dispersions can be used as adhesives.

The layered sheet thus obtained is subjected to a surface treatment.

In order to further elucidate the invention, the following examples are provided.

Example 1

Polyurethane-type polyurethane is used to prepare, by coagulation process, a base polymeric microporous film having a thickness of 1.6 mm with a uniform pore size throughout the cross section and a bulk density of 0.4 - 0.6 g.cm < -1 >. mm due to temperature and pressure between a pair of cylinders, one of which is heated. A 1.4 mm slot is set between the rollers and the temperature of the heated roll is 140 - X50 ° C (the exact temperature value depends on the pore size and the working speed).

The leveled foil is split on a belt splitter to two layers of different thicknesses: one with a thickness of 0.3 - 0.4 mm, the other with a thickness of 1.2 - 1.3 mm. The microporous layer 1.2 - 1.3 mm thick is surface treated. A polyesterurethane solution, dyed to the desired shade, is applied to the spraying machine. This is followed by embossing on a conventional treading machine with a cylinder heated to 130 - 140 ° C. The last treatment operation is the application of a transparent solution of polyesterurethane / cellulose mixture in suitable solvents.

This modified all-polymer material is intended to replace natural leather.

A thinner layer of 0.3 - 0.4 mm thickness is bonded to a textile substrate prepared by impregnating the nonwoven fibrous layer with a polyurethane solution and subsequent coagulation. The lamination is carried out as follows: polyesterurethane solution with conc. 10 - 15 wt. is applied by rollers to the drum surface and is partially dried at 80 - 100 ° C. The coating weight after drying is between 10 - 20 g / m. An impregnated nonwoven fibrous layer is applied to the partially dried layer and removed from the roll surface.

In another part of the bonding line, a chipped microporous layer of 0.3 - 0.4 mm thickness is unwound and laminated using pressure rollers after previously activating the adhesive layer on the impregnated nonwoven layer by heat treatment at 80 - 100 ° C. This provides a layered -2-1 sheet material with a water vapor permeability of up to 6 mg-cm · hr.

Next, a water-dispersive matt mass dyed to the desired shade is applied. The wet weight depends on the color shade and varies between 60 - 120 g / m. After drying, it is embossed with a roller heated to 150 [deg.] C. while maintaining a gap between the embossing roller and the pressure roller, which is approximately 1/2 of the thickness of the embossing material. The last operation is the application of the final protective coating. The polyesterurethane spreader is used again

nitrocellulose with a weight ratio of 100: 60, the weight of the dried layer being 3-5 g / m.

This two-layer poromeric sheet material is useful for making shoe uppers.

Both materials have very good utility and processing properties, which are characterized by:

multiple bending resistance number of cycles min. 150,000 (Bally device)

Wet abrasion resistance number of cycles min. 1,000 (Veslic instrument) —2 —I water vapor permeability (mg, cm ^- , h,) 2-3

Example 2

Polymeric microporous foil of about 1.8 mm thickness is prepared from a mixture of polyether urethane and polyvinyl chloride by a fine-pored coagulation process of uniform size over a C-X rim of the spring and with a bulk density of 0.4 - 0.6 g.cm.

The leveling of the foil thickness is performed by grinding both surfaces on a 1.6 mm thick belt grinding machine.

By successive cleavage, 2 microporous layers of 0.3 mm thickness and 2 microporous layers of 0.5 mm thickness are prepared from this formation. The 0.5 mm thick layers are laminated with the impregnated nonwoven fibrous layer as described in Example 1 and surface treated. The thickness of the impregnated fiber layer may be 0.6-0.7 mm or 0.9-1.1 mm, so that the thickness of the finished materials is 1.1-1.2 mm (feminine type), respectively. 1,4 - 1,6 mm (men's type) Products are designed for production of shoe uppers.

The layers of 0.3 mm thickness are combined with a knitted fabric having a relatively high linear ductility. Therefore, it is preferable to use indirectly the method of applying the adhesive layer according to the procedure described in Example 1.

Surface treatment is carried out by means of raster rolls. The base ink layer is formed by successive deposits with screening rollers having about 625 to 3,136 mesh / cm ² ; drying at 80-110 ° C.

A further intaglio printing unit forms a discontinuous decorative layer (eg clouds) and, after drying, is applied with a raster roller having 625 mesh / cm ² , the final layer of the protective coating of softened nitrocellulose.

The product has satisfactory repeated bending resistance on a Bally flexometer (min. 100,000

187075 cycles), dry and wet abrasion resistance and sufficient water vapor permeability (min. 3 mg.cm.h.).

Example 3

A microporous polymer foil having a thickness of 2.8 mm was prepared from a solution of the polyether urethane-polyvinyl chloride mixture by coagulation. The microporous film has a considerably larger pore size on stiff surfaces than in the middle layers.

Leveling to a thickness of 2.5 mm is carried out by grinding on a belt grinding machine. The film obtained is divided into smaller thickness layers by splitting on a belt splitter as follows:

1. Coating with a thicker pore thickness of 1,1-1,2 mm;

2. coating with thicker pores with a thickness of 0,4 - 0,5 mmj

3. an inner layer with fine pores of 0,5 mm thickness;

4. Inner layer with fine pores of 0.3 mm thickness.

The internally separated fine-porous porous layers are laminated to textile substrates according to the procedures described in Examples 1 and 2 and have the same application.

The outer layers with thicker pores are used to prepare flat material with a velor character.

First, these layers are subjected to dyeing with organic dyes to the desired shade. The dyeing bath contains water, an organic dye, a surfactant, or a surfactant. a polymeric binder, e.g. of the polyacrylate type. Directional dye bath formulations (in parts by weight solution 1,2 metal-complex dyes 100 solution of anionic surfactant 100 water dispersion polyacrylate 200 water 600

Suitable organic dyes are 1,2 metal-complex dyes. The strip passes through the inking unit at normal or slightly elevated temperature (up to 40 ° C). The material retention time in the bath is about 1 min. At the exit of the strip from the bath, excess dye solution is purged and the material is dried at 80-100 ° C. This is followed by surface treatment by conventional methods. A layer with thicker pores with a thickness of 1.1 - 1.2 mm is used as the all-polymer type for the production of shoe uppers.

A layer with thicker pores of 0.4 - 0.5 mm thickness is used to prepare the laminate by laminating with a suitable textile substrate, in this case with a one-side combed polyamide fabric. An adhesive system based on water-dispersive polymeric binders of a number of polyacrylates is used to join the two layers. The aqueous dispersion of self-crosslinkable acrylates is mixed with water, thickener, and excipients to give a paste having a viscosity of 1,500-3,000 mPas and a dry matter of 25-50 l% by weight. The paste is applied with a knife to the textile substrate in an amount such that the weight of the adhesive layer after drying is 10-20 g / m. The adhesive-coated textile substrate passes through a drying tunnel heated to 100-120 ° C, then a microporous layer is laminated between the rubber rollers to allow the side

187075 with thicker pores formed the outer surface of the laminate. This formation is continued with a drying channel heated to 100-120 ° C and dried thoroughly. This is followed by grinding the surface with thicker pores with sandpaper. To improve the abrasion resistance of the velor surface, it is sprayed with an emulsion nitrocellulose lacquer, colored with organic dyes.

Directional lacquer formulation:

Emulsion nitrolac (13%) 100 Water 30 Ethanol 20

1,2 metal-complex dye (3%) 5 o

Injection weight is 10 - 20 g / m,

Water resistance is increased by hydrophobization, eg with a silicone oil solution or emulsion.

Velor materials on cotton fabric are suitable for applications in the clothing industry.

Example 4.

A microporous film with a thickness of 3.7 mm similar to that of Example 3 was prepared.

The thicknesses are leveled by hanging on a belt grinding machine. and

The separated outer layers of thickness 1.1 - 1.2 mm are characterized in that one surface has a roughly porous structure, the other is finely porous. These formations are surface treated by a conventional fine pore surface treatment process.

The surface treatment is carried out either by applying a dyed solvent system, e.g. polyurethane, using gravure printing rolls (see Example 2), or by using a water-dispersive coating composition containing, for example, polyacrylate binders (see Example 1).

In this way, an all-polymer sheet material is obtained whose porous structure is characterized by a density gradient in cross-section, similar to that of natural leather, and exhibits utility properties which permit use in the footwear industry.

The two separate layers, each 0.3 - 0.5 mm thick, are laminated discontinuously to natural leather with chipped or abraded faces. The adhesive layer is formed from an aqueous dispersion of polyester urethane densified to a viscosity of 3000 mPas. Individual pieces of natural leather are applied with this adhesive so that the weight of the adhesive layer after drying p

ranged from 10 to 20 g / m depending on the quality of the surface of the split.

After pre-drying at 60 ° C, a separate layer with a thickness of 0.3 - 0.5 mm at a temperature of max. 80 ° C and a specific pressure of 0.2 - 1 kp.cm ² is discontinuously laminated in a tray press.

The combined body is treated according to the customary procedures for the treatment of natural leather.

Advantageously, a high-gloss varnish based on polyurethane varnishes is performed. \

Impregnation with the means used to soften natural leathers is carried out as the finishing of the reverse side.

Standard lacquer formulation (in parts by weight) Polyesterurethane solution with free isocyanate groups (45%) 100 Catalyst / organotin compound (15%) 3 xylene 100

The lacquer is applied by spraying so that the weight of the lacquer layer after drying is 20-30 g.Di. ^-2 . Drying of the wet deposit is carried out at a temperature of 60-70 ° C and further allowed to be recharged under the influence of atmospheric moisture in a free storage for 24 hours.

The lacquer treatment carried out by this process has several times higher utility properties than the leather finish. Above all, the resistance to repeated bending increases without damaging the paint film.

Example 5

From a mixture of polyetherurethane with polyvinyl chloride, a microporous foil of 1.5 mm thickness is prepared on a finished ^x substrate by a caugation procedure. The top side of the film has a layer of significantly thicker pores, towards the center and to the other surface the microporous structure is substantially finer. After the film is dried, the thickness is equalized by a pressure temperature between the rollers with a slot of 1.3 mm. Depending on the softening point of the polyurethane, the temperature of the heated cylinder is between 150 - 180 ° C.

The nonwoven fibrous layer impregnated with butadiene-acrylonitrile latex is first laminated to a film thus prepared and adjusted to a thickness of 1 mm. A polyerethane aqueous dispersion containing 40-50 wt. Dry matter and concentrated to a viscosity of approximately 1 500 to 2 000 MPas. Using a knife, a layer of polyurethane new paste with a weight of 50 - 60 g / m is applied to the surface of the film with thicker pores. Immediately after the deposition, the textile backing layer is deposited, squeezed gently between the roll rolls, and the formation is dried at 120 ° C.

The laminated structure is then separated by first splitting off a microporous layer having a thickness of 0.8 mm. The laminated laminate therefore has a total thickness of 1.5 mm and is characterized by an advantageous pore size gradation from the thickest of the textile backing to the fine on the newly formed surface. Surface treatment of this semi-product is carried out with cylinders with raster and decorative engravings similar to those described in Example 2.

The remainder of the 0.8 mm thick film after surface treatment can be used as a single-layer material or split into two layers and laminated.

The thinner layer is laminated with a crosslinkable polyacrylate (see Example 3) to a synthetic fiber knit. A layer of 0.5 mm thickness is laminated to an impregnated non-woven fibrous layer of 0.7 mm thickness as described in step 1 using a polyurethane solution applied to the heated hub.

Upon light aniline treatment, upper material for women's shoes is obtained

Claims (5)

OBJECT OF THE INVENTION A method for the simultaneous production of at least two kinds of flexible sheet materials comprising a porous polymer layer prepared by precipitation of a polymer solution layer, characterized in that by precipitation a self-supporting film or porous layer having a bulk density of 0.2-0.9 g / cm @ -1 and total thickness is prepared. 0.5 - 10 mm on the fibrous backing and the precipitated formation is mechanically separated into at least two layers of 0.1 - 2 mm thickness, which are joined to the fibrous backing or used as a self-supporting material. 2. Method according to claim 1, characterized in that a porous formation is obtained by precipitation, which comprises layers with pores of different size, preferably 1 to 10 [mu] m in diameter, and 20 - 200 µm. 3. A method according to claim 1, characterized in that the precipitated polymer layer is firstly unilaterally or bilaterally bonded to the substrate and then divided into the desired thicknesses. 4. Method according to claims 1 and 2, characterized in that the porous formation prepared by shrinkage is first abraded on at least one side with pores having diameters of 20-300 [mu] m, preferably 20-200 [mu] m, on a velor surface. 5. Method according to claim 1 or 2, characterized in that the porous formation prepared by precipitation is first coated with at least one side.