Formulações de borracha de silicone de componente único reticuláveis sob temperatura ambiente com ácidos silìcicos hidrófobos

• Main Authors: MARIO SCHOLZ, KENICHI KAWAMOTO, MICHAEL KEMPF, CHRISTIAN PANZ
• Format: Patent
• Language: Portuguese
• Published: 09.09.2003
• Edition: 7
• Subjects: ADHESIVES; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; DYES; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; POLISHES; PREPARATION OF CARBON BLACK; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS,TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS

"FORMULAçõES DE BORRACHA DE SILICONE DE COMPONENTE úNICO RETICULáVEIS SOB TEMPERATURA AMBIENTE COM áCIDOS SILìCICOS HIDRóFOBOS". A invenção refere-se a formulações de borracha de silicone de componente único (RTV-1K) reticulável à temperatura ambiente com ácidos silícicos hidrófobos, que apresentam uma absorção d'água extraordinariamente reduzida, um elevado grau branco e propriedades reológicas exatas ajustáveis bem como estáveis ao armazenamento com elevado efeito espessante nos vulcanizados de borracha de silicone. Introduction of hydrophobic silicic acid of low water content and low moisture uptake into a single component room temperature crosslinked silicone rubber formulation, improves the mechanical properties, the whiteness grade and the rheological properties without affecting the storage stability. A silicone rubber formulation (RTV-1K) contains: (a) 0.5-60 wt.% of hydrophobic silicic acid having the properties: C content less than 3.1%, methanol utilizability greater than 60%, remission value greater than 94%, BET/STAB ratio greater than 1 and less than 3, DBP take up less than 230 g/100 g, BET surface 50-110 m2/g, STAB surface greater than 30 m2/g, water vapor absorption at 30 degrees C and 30 RF less than 1.3 and at 30 degrees C and 70 REF less than 1.7, and (b) 40-99.5 wt.% of an organopolysiloxane of formula (I). ZnSiR3-n-O-(SiR2O)x-SiR3-nZ'n (I) R = alkyl, acetoxy, oxime, alkoxy, amido, aryl, 1-50C alkenyl, optionally substituted with O, S, F, Cl, Br or I, and/or polystyrene, polyvinyl acetate, poly(meth)acrylate- or polyacrylonitrile with 50-10,000 repeating units; Z = OH, Cl, Br, I or up to 20 C acetoxy, amino, amido, aminoxy, oxime, alkoxy, alkenyloxy, acryloxy or phosphate, where the organic residue can have up to 20 C; Z' = oxime, alkoxy, amido or acetoxy; n = 1-3; and x = 100-15,000.