Abstract: A paper- or cardboard-based security product and a method of manufacturing it. The product comprises a paper or a cardboard which is equipped with an identifiable security symbol. According to the present invention, the security symbol comprises a layer in the product, one which consists of a synthetic, electrically conductive polymer, the conductivity of which has been changed locally to form an electrically conductive or, alternatively, electrically non-conductive figure. Furthermore, a figure indicating the security symbol has been fitted on the surface of the paper or the cardboard product. A security product according to the present invention can be produced simply by first applying a conductive polymer, for instance in a non-conductive form, onto a paper, after which an acidic figure is printed in such as way that the area below the figure becomes conductive. The figure can be detected and in this way it acts as a guarantee of authenticity for the product.

Abstract: A process of producing a fibrous composition, which includes a first component that comprises vegetable fibres and a second component that consists of a synthetic, electrically conductive polymer. According to the method, the vegetable fibres comprise porous, loose and separate fibres, and the electrically conductive polymer is an independently electrically conductive polymer which is doped in order to generate charge carriers in the polymeric material, the synthetic polymer being produced by in situ—polymerization inside the fibres and on their surfaces. The doping agent is an organic sulphonic acid which is allowed to absorb into the fibres in an aqueous medium, and after that a monomer corresponding to the polymer is brought into contact with the fibres and polymerised. By means of the invention, the electrically conductive polymers are attached to fibres so firmly that they are not substantially out-washable by water.

Abstract: Multilayered product and method for the production thereof. The product comprises at least one first layer, which is formed by cellulosic or lignocellulosic fibres, and at least one second layer, which is adjacent to the first layer or fitted at a distance therefrom. According to the invention the second layer contains a synthetic, electrically conducting polymer which is mixed with a binder which forms a binder matrix, said second layer being at least partially electrically conductive. By means of the invention it is possible to produce electrically conductive laminates which are suitable for authenticity products.