Layered material and method for producing a layered material

A process for the production of a surface-structured layer material, which comprises a backing layer (1) and a layer (2) of polyurethane connected thereto, wherein a leather, preferably a polished grain leather or a cowhide split leather, a textile fabric, preferably a woven or knitted fabric, a cellulose fiber material, an expanded foam, a leather fiber material or a microfiber fleece is used as the backing layer (1), in particular in fragmented form, and bonded to the layer (2), wherein at least one layer, preferably a single layer of a thermoplastic PU foam, in particular one containing gas bubbles, preferably a PU expanded foam, optionally containing hollow microspheres, and/or a PU foam containing hollow microspheres, is applied to the backing layer (1) as the layer (2), characterized in that

• the PU foam containing, in particular, gas bubbles, is produced with a PU dispersion mixture, the individual PU dispersions used to produce the PU dispersion mixture exhibiting different softening points in dried state,
• for the production of the PU dispersion mixture, one or more PU dispersions with heat-activated melt or contact adhesive properties and with a softening point in dried state higher than 40° C., preferably higher than 45° C., in the amount of 18 to 52% by weight of the finished PU dispersion mixture and one or more PU dispersions without melt or contact adhesive properties and with a softening point higher than 95° C., preferably higher than 125° C., in the amount of 39 to 73% by weight of the final PU dispersion mixture, are mixed,
• the PU dispersion mixture for the layer (2) is applied to the backing layer (1) with a thickness that, in dried state, ranges between 0.075 to 0.450 mm, preferably between 0.150 and 0.280 mm,
• before or at the same time as a structuring of the PU foam, an additional layer (3) of a non-foamed PU dispersion, representing a mixture of several PU dispersions, is applied to the layer (2),
• wherein the additional layer (3), which is built up with, optionally aliphatic, polyether, polyester and/or polycarbonate polyurethane, has a thickness of 0.015 to 0.060 mm, preferably 0.020 to 0.045 mm, after the solidification or drying, has a hardness greater than 70 Shore A, is not adhesive at temperatures of 125 to 165° C. and is optionally not thermoplastic.
• in that the layer (2) is brought to a temperature of 110 to 165° C., preferably 120 to 155° C., with the layer (3) for structuring,
• in that the cut-to-size and stamped parts (30) or the backing layer (1) are loaded during structuring, in particular to compensate for thickness variations in the backing layer (1) and to fully press the PU foam into the recesses of the mold (4) and to anchor it in the backing layer (1), by means of a pressure-elastic base part (10) which is at least as large as the part to be structured, and the backing layer (1), the additional layer (3) and the layer (2) are pressed together and bonded, by means of applying a contact pressure of 4 to 48 kg/cm2, preferably of 18 to 25 kg/cm2, and are structured with a mold (4), wherein the dried layer (2) is simultaneously or together with the additional layer (3) subjected to pressure with the structured mold (4) and a structuring is formed or stamped on the surface of the layer (2) and the additional layer (3) applied to the layer (2),
• wherein the layer (2) remains thermoplastic and the layer (2) and the additional layer (3), which is thinner and harder than the layer (2), cannot be separated after three-dimensional structuring has taken place, but can still be stamped several times or can be additionally structured with other stampings.