Back to results
US 4,318,959 AGranted
Low-modulus polyurethane joint sealant
OwnerRobert M. Evans, Thomas M. Leonardinventors
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
OwnerRobert M. Evans, Thomas M. Leonardinventors
Estimating the term…
A profound improvement in the properties and capabilities of elastomeric polyurethane joint sealing compositions is achieved by incorporating a fibrillated polyolefin of high surface area which is rendered compatible by combining it with effective stabilizing cofillers, such as titanium dioxide, calcium carbonate, carbon black, fibrous talc, serpentine, kaolin, or various other metal silicate fillers. Such cofillers are capable of improving compatibility and stabilizing the sealant mixture so that unacceptable sweat out or exudation of liquid is prevented and so that the outer surface of the applied sealant has an acceptable surface quality after curing. When 2 to 8 percent by weight of fibrillated polyolefin of macrofibrillar structure, preferably containing macrofibrils with diameters from 1 to 10 microns, is incorporated in a polyurethane joint sealant together with 8 to 30 percent of stabilizing cofillers, it becomes possible to provide revolutionary new joint sealants with remarkable properties, such as Boeing sag values of 0.1 and below for caulking compositions applied to extremely wide joints. These unique non-sag joint sealants can be compounded to form strong soft low-modulus elastomers ideally suited for vertical joints subject to extreme cyclical movement as is common in modern building construction.
A laminate comprising two layers of glass secured together along their inner edge portions by an interposed layer of an elastomeric polyurethane sealant composition having a Shore A durometer hardness not in excess of 40 and an elongation of at least 150 percent, said polyurethane composition containing 2 to 8 percent by weight of a fibrillated polyolefin with a surface area of at least 5 square meters per gram and 8 to 30 percent by weight of a compatible cofiller that stabilizes the composition to prevent substantial exudation of liquid.
In an insulating glass unit comprising a pair of flat glass panes held in parallel spaced relation by a peripheral elastomeric sealant interposed between and adhered to the edge portions of the panes, said sealant containing at least 30 percent by weight of a polyurethane prepared by reacting an aromatic diisocyanate with a hydroxyl-terminated polydiene having a molecular weight of 2000 to 5000, the improvement wherein said sealant contains 2 to 8 percent by weight of a fibrillated polyolefin with a surface area (BET) of at least 5 square meters per gram and 8 to 30 percent by weight of a compatible cofiller that stabilizes the composition to prevent substantial exudation of liquid.
An article comprising a glass member, a metallic member for supporting said glass member, and an elastomeric polyurethane joint sealant composition disposed between and adhered to said glass member and said metallic member to hold them together, said joint sealant composition comprising 30 to 70 percent by weight of a polyurethane prepolymer with a free NCO content of 1.5 to 8 percent, up to 45 percent by weight of a plasticizer, 2 to 8 percent by weight of fibrillated polyolefin with a surface area (BET) of 5 to 30 square meters per gram, and 8 to 30 percent by weight of a compatible stabilizing cofiller that prevents substantial exudation of liquid.
An article comprising a first rigid metallic member, a second rigid member spaced from said first member to provide a narrow joint, and an elastomeric polyurethane joint composition disposed between and adhered to said members to seal said joint, said composition comprising 30 to 70 percent by weight of a polyurethane prepolymer with a free NCO content of 1.5 to 8 percent, up to 45 percent by weight of a viscous plasticizer, 2 to 8 percent by weight of fibrillated polyolefin with a surface area (BET) of at least 5 square meters per gram comprising a major portion by weight of macrofibrils with a diameter of 1 to 10 microns and an average length up to 1 millimeter, and 8 to 30 percent by weight of a compatible cofiller that stabilizes the composition to prevent substantial exudation of liquid.
Dependencies are inferred from the claim text.