Patent ZA-200901213-B (ZA)
Title: Method for the production of a breathable multilayer synthetic leather,and breathable multilayer synthetic leather
Inventor: FISCHER BERND
IPC: D06N/
Filed: 2009-02-20
Abstract: The manufacturing of breathable multilayered artificial leather with a carrier layer (3) from a textile surface structure for motor vehicles as seat cover, comprises applying and hardening a covering layer (1) on a removable base with a thickness of 30-100 mu m in a dry condition of 30-40 g/m 2>, applying an intermediate layer (2) on the covering layer based on a polyurethane, applying the intermediate layer on the carrier layer based on partially opened cell polyurethane-impact foam, and removing the base from the covering layer. The manufacturing of breathable multilayered artificial leather with a carrier layer (3) from a textile surface structure for motor vehicles as seat cover, comprises applying and hardening a covering layer (1) on a removable base with a thickness of 30-100 mu m in a dry condition of 30-40 g/m 2>, applying an intermediate layer (2) on the covering layer based on a polyurethane, applying the intermediate layer on the carrier layer based on partially opened cell polyurethane-impact foam, removing the base from the covering layer, applying and imprinting an aqueous aliphatic polyurethane dispersion in fluid form on the base for the formation of the covering layer with a solid content of 30-60 %, vaporizing the water content of the polyurethane dispersion by supplying heat within a short time and producing a film free drying of the dispersion on the base under the formation of the covering layer with micropores. The micropores are produced with a diameter of 10-70 mu m in the covering layer. The dispersion is sprayed on the base in drop form by an injection nozzle. The application of the dispersion on the base is carried out by a screen- and/or sieve printing process. The base is formed in the form of strip-shaped and continuous circular manner and is led over a heated roller to heat the base on a suitable temperature for the vaporization of the water content of the dispersion. The dispersion applied on the base is heated by heat radiation and/or microwaves for the vaporization of the water content. The heat supply is carried out by the base. The water content of the dispersion applied on the base is vaporized in less than 5 seconds. A siliconized textile surface structure or siliconized paper or a metallic substrate or a fabric coated with polytetrafluoroethylene is used as base of a plastic foil. The base is provided with an upper surface profile. The dispersion contains water-soluble and low-boiling organic solvents. The intermediate layer is applied on the covering layer. The intermediate layer has a foam weight of 400-500 g/l. Two intermediate layers are applied one after the other in a thickness of 200-800 mu m on the covering layer and/or the intermediate layer. The first intermediate layer applied on the covering layer has a foam weight of 400-600 g/l and the second intermediate layer has a foam weight of 300-500 g/l. The intermediate layers are produced with an average pore size of 100-200 mu m. A varnish layer (4) is applied on the covering layer, whose side is turned away to the intermediate layer after the removal of the base. The upper surface of the covering layer is embossed after the removal of the base by vacuum embossing or an edge-shaped embossing profile. A clutch, tissue, fabric, fleece or its combinations is used as the carrier layer with or without impregnation. The carrier layer is applied on not yet completely dried up intermediate layer, so that the carrier layer partially sinks into the intermediate layer. An independent claim is included for breathable multilayered artificial leather with a carrier layer from textile surface structure.