Foil adhesive system

Claim 1

A PROCESS OF BONDING METAL FOIL, COMPRISING THE STEPS OF PROVIDING METAL FOIL COATED WITH AN ADHESIVE COMPOSITION RESISTANT TO PREMATURE BONDING, AND SUBSEQUENTLY SUPERIMPOSING PIECES OF FOIL WITH SAID COATING THEREBETWEEN AND BONDING THEM TOGETHER BY THE APPLICATION OF HEAT AND PRESSURE, SAID ADHESIVE COMPOSITION HAVING (1) A RESIN COMPONENT, (2) A PLASTICIZER COMPONENT, AND (3) A COMPONENT OF INERT PARTICLES, SAID RESIN COMPONENT (1) CONSISTING OF A FIRST MATERIAL COMPRISING SOLVENT-SOLUBLE COPOLYMERS OF A VINYL HALIDE, A VINYL ESTER OF A LOWER SATURATED FATTY ACID, AND AN ALIPHATIC ALPHA, BETA-MONO-OLEFINIC CARBOXYLIC ACID, THE AMOUNT OF CARBOXYLIC ACID COMBINED IN THE COPOLYMER BEING BETWEEN ABOUT 0.1% AND ABOUT 4% BY WEIGHT OF THE POLYMER AND THE CARBOXYL GROUPS IN THE POLYMER BEING SUBSTANTIALLY UNREACTED, SAID FIRST MATERIAL CONSTITUTING ABOUT 50% TO 100% BY WEIGHT OF THE RESIN COMPONENT (1), THE BALANCE OF RESIN COMPONENT (1) BEING A VINYL POLYMERIC MATERIAL COMPATIBLE WITH SAID FIRST MATERIAL AS EVIDENCED BY CLARITY OF A SOLUTION OF A MIXTURE OF SAID MATERIALS, SAID PLASTICIZER COMPONENT (2) CONSISTING OF A PLASTICIZER FOR THE RESIN COMPONENT (1) WHICH HAS A BOILING POINT ABOVE 200*C., AND IS FLUID AT ABOUT 25*C., AND SAID COMPONENT (3) CONSISTING OF SMALL DISCRETE PARTICLES OF SILICA AEROGEL WHICH IS NOT CHEMICALLY OR PHYSICALLY ALTERED BY INTERMIXTURE WITH THE OTHER TWO COMPONENTS, THE PROPORTION BY WEIGHT OF THE RESIN COMPONENT BEING 60% TO 80% OF THE COMBINED WEIGHT OF THE RESIN AND PLASTICIZER COMPONENTS (1) AND (2), THE BALANCE OF SAID COMBINED WEIGHT BEING THE PLASTICIZER COMPONENT (2), AND THE PROPORTION OF THE SAID COMPONENT (3) BEING 1% TO 20% OF THE COMBINED WEIGHT OF THE SAID COMPONENTS (1), (2) AND (3).