DE1253665B - Process for the production of synthetic leather-like laminates - Google Patents

Description

Process for the production of synthetic leather-like laminates The invention relates to a method for producing synthetic leather-like laminates by connecting open lattice-like fabrics, nets or similar carrier materials textile or non-textile origin with a film by coating on both sides of the composite of carrier material and film with spreadable plastic pastes containing carbon black based on vinyl chloride polymers or other thermoplastics and gel the coating compounds.

When coating mesh fabrics with the help of pastes according to the It is known in a coating process to apply a plastic film to one side of the fabric apply and then coat the other side using one of the paste processes.

The film side can also be coated with pastes afterwards will. Depending on the choice of film used, this process will be very Good strengths of the composite material achieved, even if the film in its composition usually differs from the composition of the pastes used.

Laminates are also known in which individual layers are conductive are, with optionally also insulating layers between the conductive layers Layers can be located.

Now coated mesh fabrics are used for special purposes required that not only have a certain surface conductivity, but also a Conductivity through the composite material (low volume resistance) have a safe discharge of static electricity or electrostatic Top-ups is possible. When working according to the very simple and cheap painting method such requirements could not be met so far, because the auxiliary film used due to their different composition always acts as a barrier layer.

The invention is characterized in that to produce a continuously conductive laminate the carrier material with a thin plastic film is connected on the basis of plasticized thermoplastics in such a way that that the warm, softened film with the application of pressure at the majority of the crossing points of the carrier material is broken.

As a carrier material, all known fabrics, nets or Similar underlay or carrier materials are used that provide the necessary Structure with a large number of local, roughly punctiform elevations (crosshair points, Knobs and the like) and tissue or grid gaps of about 30 to 90% of the total area own.

So you can z. B. also use wire mesh, but will preferably mesh fabric made of synthetic fibers z. B. based on polyesters or polyamides are used. These so-called synthetic fabrics are excellent Results of the composite material achieved with regard to mechanical values (tear resistance, Adhesion of the coating and the like) and in particular with regard to the invention important assets, a large number of breakouts in the plastic film to create. The thread count, d. H. the number of threads in a square Thread counters of 1 cm edge length counted in the warp and weft directions, aligns itself according to the strength of the threads. They should expediently in the weft and warp directions each about 2 to 12 threads per centimeter with a thread thickness of about 1000 to 100 denier. For example, choose a material of 1000 denier Polyester fibers or 840 denier polyamide fibers expediently a thread density between 2/2 and 7/7, with thinner material e.g. B. of 250 or 210 denier a higher thread density up to about 10/12 threads per centimeter.

As a plastic film, all films are of the appropriate thickness and Adhesive strength to the fabric and suitable for the coating to be applied.

Conventional foils with a predominant content have proven particularly useful of plasticized polyvinyl chloride (soft polyvinyl chloride), which after the calender or blow molding, in a thickness of 0.05 to 0.15 mm. the Plasticization of this film can be carried out by measures known per se, such as the selection of the Polymers and / or copolymers with a suitable molecular weight and / or Addition of known plasticizers. Of the to achieve the Breakthroughs above the crosshairs or intersections during lamination on the fabric, net or the like. The most favorable degree of softness of the film can be passed through easy to determine simple preliminary tests. As a material for the plastic film you can besides polyvinyl chloride and the vinyl chloride copolymers also other known ones and suitable homopolymers and / or copolymers are used, such as. B. polyamides. The laminating film itself can also contain other additives known per se, such as. B. light and heat stabilizers, lubricants, adhesion promoters, dyes and; or fillers such as chalk, silica, talc, graphite, carbon black, flame retardant additives among others. It should only be noted that the film used is made of such a material and such mixtures that can also be used with the plastic pastes to be applied later connects well.

This is the best way to proceed in the manufacture of this composite material before that the film and carrier material are brought together cold, then from the film side forth with a heating unit through direct heat transfer by means of a heated one The film is heated to about 135 to 160 ° C. by roller and / or by radiant heating and at the same time or afterwards by roller pairs with one adjustable as desired Pressure compresses the composite. Preheating the film without the carrier material running along is possible, but not recommended because the thin film does not require any special guidance Easily deformable in the heat and also against mechanical injuries in the Is usually very sensitive. In the doubling device, the Materials advantageously performed so that the film against the usually heated and if necessary with polytetrafluoroethylene or the like coated steel roller runs, while the fabric is pressed on with the help of the softer hard rubber pressure roller and is pushed through. The pressure of the pressure rollers is usually chosen to be higher, than is necessary for a corresponding normal doubling process. You want here to achieve precisely what must otherwise be avoided under all circumstances, namely piercing the film at the intersection or crossing points of the textile structure or mesh fabric. The pressure required and appropriate for this can be determined in a preliminary test can be determined very quickly and easily. Except for this roller lamination process However, other methods known per se can also be used to produce the composite Find use.

Both sides are known to the composite material produced in this way antistatic or known electrically conductive coatings using the paste coating process applied, or also z. B. Coatings with a high metal or heavy metal content.

The lamination process results in perforation or punctures of such a type and number that, on the one hand, a coating after the paste coating process without dripping through or smearing the back with normal coating pastes is possible, but that also on the other hand the connection of the coatings on the front and back of the web through the film Achievement of the continuous conductivity is guaranteed to a sufficient extent. This is due to the special type of opening at the crosshairs or crosshairs. - Intersections are made by simply perforating a plastic film cannot be reached. The use of such treated films would also require the additional operation of punching.

As already mentioned, when one-sided painting occurs with conductive Coating masses some mass at the penetration points of the film at the crosshair points through and shaft so a conductive connection to the subsequently on the opposite side to be applied coating compound. Since the penetration points of the foil only at the intersection or. -Interfaces of the carrier material are located, the mass is thereby still held by the carrier material, and the risk of the coating slip dripping through and thus the smearing of the coating device is practically eliminated. Of course, several lines of the conductive coating compound can also be used on both sides can be applied in strengths and compositions as appropriate for the specific Application purpose are required.

For the production of conductive coatings on this composite material Plastisols and / or organosols based on polyvinyl chloride plasticizers are particularly suitable, those by the appropriate addition of z. B. highly conductive carbon blacks the desired Conductive properties were given. Such mixtures are for example described in patent 1217,916.

But it can also be done in a different way than the one described above Coating compositions made conductive find use. The application of pure aqueous plastic dispersions are not recommended in most cases, because here the bond with the base material is not very strong and the resulting Coatings are not very resistant.

As was also found, coatings have proven particularly useful, consisting of a mixture of a) about 35 to 90 parts by weight of a stock paste, consisting of vinyl chloride polymers such as polyvinyl chloride and / or vinyl chloride copolymers, and a customary plasticizer content, preferably a plasticizer content between 45 and 60 percent by weight of the polymer fraction, b) about 65 to 10 parts by weight a carbon black paste of electrically conductive carbon black with sufficient for paste formation Amount of plasticizer; and c) about 2 to 12, preferably 3 to 7 parts by weight of one 15 to 40 weight percent, preferably 20 to 30 weight percent solution of polymers in organic solvents.

The mixtures can also contain additives known per se, such as adhesion promoters, Heat and light stabilizers, crosslinkers, blowing agents, dyes, fillers and the like. Like. Contain the directly or via one or more of those mentioned under a) to c) Components of the mixture can be fed.

For the production of the master paste, as easily as possible pastable, little Polyvinyl chloride types and / or copolymers that require plasticizers are used, which you can use for pasting at temperatures below or up to about 25 ° C sufficient amounts of plasticizers and, if necessary, extenders at lower levels mechanical stress, so that a gelation and / or Swelling the polymer particles is avoided as far as possible.

For the production of the carbon black paste they are already considered to be highly conductive known types of carbon black from acetylene, furnace or channel blacks with specific Surfaces of more than 100 m2 / g used. These carbon blacks are made with the same or other compatible plasticizers, such as those used for the production of plastisol pastes Find use, mixed and homogenized in kneaders and / or on the roller mill, where, as with the parent paste itself, only a minimum of plasticizers, if possible, d. H. only so much plasticizer is used that the carbon black is evenly wetted and a mass of an ointment-like consistency is created.

Copolymers in particular have been used for the production of the polymer solution of vinyl chloride proved suitable, e.g. B. with styrene, vinylidene chloride, unsaturated Carboxylic or dicarboxylic acids, but especially with vinyl acetate, individually or as a mixture; however, mixtures of different such polymers or copolymers can also be used be used. The solvents used for these polymers have differed from the organic ones Liquids especially polar compounds have been proven, including especially those made of the groups of ethers, ketones and esters. These solvents can also be used individually or in a mixture or possibly also with solvents from other substance classes come into use together.

The mixing of the stock paste, carbon black paste and plastic solution takes place expediently by stirring in the carbon black paste and the plastic solution at the same time into the stock paste with a low-shear stirrer or through Stir the carbon black paste into the two other components of the mixture.

The mixtures described can be perfectly applied by the paste coating process process and deliver coatings of excellent quality. The association too to the support sheet is very good. The conductivity or the antistatic properties of the end product can be reduced by the carbon black content of the coating compounds Limits can be varied and adjusted.

Claims (3)

Claims: 1. Method for producing artificial leather-like Laminates by joining open lattice-like fabrics, nets or the like Carrier materials of textile or non-textile origin with a film on both sides Coating of the composite of carrier material and film with spreadable carbon black containing Plastic pastes based on vinyl chloride polymers or other thermoplastics and gelation of the coating compositions, characterized in that for production a continuously conductive laminate, the carrier material with a thin Plastic film based on plasticized thermoplastics is so connected that the warm, softened sheet under pressure is applied to the majority the intersection of the carrier material is broken. 2. The method according to claim 1, characterized in that a paste-like mixture is used as the coating compound from a) 35 to 90 parts by weight of a stock paste consisting of vinyl chloride polymers and a customary amount of plasticizer, b) 65 to 10 parts by weight of a carbon black paste of electrically conductive carbon black with a sufficient amount of plasticizer to form a paste and c) 2 to 12 parts by weight of a 15 to 40 weight percent solution of polymers is used in organic solvents. 3. The method according to claim 2, characterized in that additives known per se such as light and heat stabilizers, adhesion promoters, crosslinkers, blowing agents, fillers, dyes and the like are also introduced into the paste. Considered publications: German Auslegeschriften No. 1103 007, 1038 953; Austrian patent specification No. 188 907.