Patent DE-102008039326-A1 (DE)
Title: Preparing electrically insulated electric sheet, to prepare laminated magnetic core, comprises coating one side of sheet using liquid mixture comprising hydrolyzed and condensed metal organic monomer, and heat treating coated sheet
Inventor: ZOCH HANS-WERNER
IPC: H01F3/02
Filed: 2008-08-22
Abstract: Method for preparing an electrically insulated electric sheet comprises: (a) coating at least one side of the electric sheet by applying a liquid mixture comprising the hydrolyzed and condensed metal organic monomer; and (b) heat treating the coated electric sheet initially at room temperature to 120[deg] C for 240 minutes, followed by heat treating at 220[deg] C to maximum of 400[deg] C in air or gas, other oxygen-containing gas for maximum of 300 minutes, and finally at 500[deg] C to maximum of 850[deg] C for maximum 300 minutes under vacuum or inert gas. Method for preparing an electrically insulated electric sheet comprises: (a) coating at least one side of the electric sheet by applying a liquid mixture comprising a hydrolyzed and condensed metal organic monomer, where the mixture is prepared from (i) at least one organosilane of formula ((R 1>) mSi(OR) n) (I), (ii) at least one compound of alkali- or earth alkali-hydroxide or -oxide or an acid dissolved in water, and (iii) optionally at least one metal alcoholate (which is alkoxide of silicon compound of formula (Si(OR 4)), aluminum compound of formula (Al(OR) 3), magnesium compound of formula (Mg(OR) 2), yttrium compound of formula (Y(OR) 3), cerium compound of formula (Ce(OR) 4), zirconium compound of formula (Zr(OR) 4) or titanium compound of formula (Ti(OR) 4)) or -acetyl acetonate (which is 2,4-pentane dionate of formula R=CH 3OCCHCOCH 3->), the portion of the organosilane in the metal organic monomer, relative to the total from the organosilane and metal-alcoholate or -acetyl acetonate, is 30-100 mol% and the pH of the liquid mixture is 6.5 or greater; and (b) heat treating the coated electric sheet initially at room temperature to 120[deg] C for 240 minutes, followed by heat treating at 220[deg] C to maximum of 400[deg] C in air or gas, other oxygen-containing gas for maximum of 300 minutes, and finally at 500[deg] C to maximum of 850[deg] C for maximum 300 minutes under vacuum or inert gas. R 1>H, alkyl (-C pH 2p+ 1), alkenyl (-C p+1H 2p+1) (e.g. vinyl), phenyl, allyl, acryl, acryloxyalkyl (-C pH 2p(CO)CH=CH 2), methacryl, methacryloxyalkyl (-C pH 2p(CO)C(CH 3)=CH 2) or glycidoxyalkyl (-C pH 2pOCH 2(CHOCH 2)); R : alkyl; and p : 1-14. Independent claims are included for: (1) the electrically insulated electric sheet obtained by the above method; (2) laminated magnetic core comprising at least two of the above electrically insulated electric sheet; (3) a process for the preparation of the laminated magnetic core comprising coating the electrically insulated electric sheet, provided that between the step of heating at 220[deg] C to maximum of 400[deg] C and the step of heating at 500[deg] C to maximum of 850[deg] C, or during the step of heating at 500[deg] C to maximum of 850[deg] C, the electric sheet is molded, where the molding step is carried out by bending or punching; and (4) a product with the laminated magnetic core.