Abstract: A method for effectively decreasing electromagnetic radiation by means of active absorbing material in a broad frequency band, preferably from 100 MHz-10 GHz, is provided wherein the material combines the desired shielding properties with the heat insulating properties of a porous material in addition to providing a favourable ratio between density and resistance. The method includes use of an absorber granulate which consists of a highly porous glass and/or ceramic granulate which is coated or filled with ferrite and/or an electrically conductive material.

Abstract: The invention relates to a method for effectively decreasing electromagnetic radiation by means of active absorbing material in a broad frequency band, preferably from 100 MHz-10 GHz, wherein said material combines the desired shielding properties with the heat insulating properties of a porous material in addition to providing a favourable ratio between density and resistance. The inventive method is characterised by an absorber granulate which consists of a highly porous glass and/or ceramic granulate which is coated or filled with ferrite and/or an electrically conductive material.

Abstract: The present invention relates to modifying agents for melamine-formaldehyde resins and highly reactive thermosetting resins which are prepared with this agent and consist of 1 mol of melamine, 1.5 to 3.5 mol of formaldehyde, 0.5 to 5% by weight of a polyhydric alcohol, based on the melamine plus formaldehyde, and 0.5 to 10% by weight of the modifying agent, based on the liquid resin. The modifying agent can be added to the melamine-formaldehyde resin as a pulverulent mixture before or during the condensation reaction or in the liquid state in the form of a condensation product prepared in a known manner. The modifying agent consists of 10 to 75% by weight of dicyandiamide, 5 to 70% by weight of cold water-soluble starch (soluble between about 18.degree. and about 25.degree. C.) and 20 to 85% by weight of a guanamine. The highly reactive resins modified in this way are preferably used for coating chipboard and hardboard by a short cycle process.