Moisture-curable silicone pressure-sensitive adhesives
AssigneeDow Corning Corporation
InventorsRobert H. Krahnke, Shawn K. Mealey, William J. Schoenherr, Schuyler B. Smith, deceased, Thomas J. Tangney
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Abstract
Silicone pressure sensitive adhesive compositions which cure in the presence of moisture comprise an adhesive component which bears alkoxy radical-containing curing radicals and, optionally, a catalyst to accelerate the reaction of moisture with the alkoxy radicals to form siloxane bonds. Curing provides adhesives ranging from pressure sensitive adhesives having improved properties to permanent adhesives. The adhesives are useful for adhering an object to a surface and thereafter improving the bond between the object and the surface by exposure to moisture.
Claims19
A composition comprising a silicone pressure sensitive adhesive component bearing curing radicals having the formula (MeO).sub.3 SiC.sub.2 H.sub.4 SiMe.sub.2 O-- wherein Me denotes methyl and wherein the silicone pressure sensitive adhesive component bearing curing radicals has been prepared by a method comprising reacting (i) a silicone pressure sensitive adhesive composition having reactive sites of the formula .ident.SiX, and X denotes an alkenyl radical, a hydroxyl radical or a hydrogen atom, substantially all X being OH, with (ii) a moisture-reactive compound having the formula {(MeO).sub.3 SiC.sub.2 H.sub.4 SiMe.sub.2 }.sub.2 NH;
- all other silicon-bonded radicals in (i) being selected from the group consisting of divalent oxygen atoms linking silicon atoms, hydrogen atoms and monovalent hydrocarbon radicals.
A silicone pressure sensitive adhesive bearing curing radicals of the formula (MeO).sub.3 SiC.sub.2 H.sub.4 SiMe.sub.2 -obtained by the method comprising reacting (i) a silicone pressure sensitive adhesive composition having reactive sites of the formula .ident.SiX and X denotes an alkenyl radical, a hydroxyl radical or a hydrogen atom, substantially all X radicals being hydroxyl, with (ii) a moisture-reactive compound having the formula {(MeO).sub.3 SiC.sub.2 H.sub.4 SiMe.sub.2 }.sub.2 NH, Me denotes methyl;
- all other silicon-bonded radicals in (i) being selected from the group consisting of divalent oxygen atoms linking silicon atoms, hydrogen atoms, hydroxyl radicals and monovalent hydrocarbon radicals.
A composition comprising a moisture-curable silicone pressure sensitive adhesive selected from the group consisting of a mixture of an organopolysiloxane resin with a polydiorganosiloxane gum having a viscosity at 25.degree. C. of at least 1,000,000 centipoise and a bodied product thereof wherein at least one of said organopolysiloxane resin, said polydiorganosiloxane gum or said bodied product bears curing radicals having the formula R.sub.b (R'O).sub.3-b SiZ-- wherein Z denotes a divalent radical linking the silicon atom of the curing radical to a silicon atom of the silicone pressure sensitive adhesive, R denotes a monovalent hydrocarbon radical, R' denotes an alkyl radical or alkoxyalkyl radical, and the subscript b has a value of 0 or 1;
- all other silicon-bonded radicals of the silicone pressure sensitive adhesive being selected from the group consisting of divalent oxygen atoms linking silicon atoms, hydrogen atoms and monovalent hydrocarbon radicals.
Dependencies are inferred from the claim text.