H.b. Fuller Company

James A Collins

Thomas H Quinn

Bernard T Juba

Paul A Englund

The disclosed article (e.g. a sanitary napkin) typically comprises (1) an elongated absorbent pad, (2) an outer covering layer in adherent contact with at least one surface of the pad, (3) an adhesive strip or layer on the exposed surface of the outer layer, and (4) a release liner for protecting the adhesive layer. The adhesive layer is useful for removably attaching the article to the inside of an undergarment or the like. Production of the article can be greatly simplified by using a hot-melt pressure sensitive adhesive (PSA) as the adhesive layer. However, the rubbery base for the hot-melt PSA should be very carefully selected. Two types of rubbery polymers provide good results, i.e. (a) an A-B-A block copolymer having polystyrene end blocks and a rubbery poly(ethylene-butylene) midblock and (b) a radial teleblock copolymer with branches having polystyrene terminal blocks and a butadiene segment in the center. One or both of these rubbery polymers is used to formulate the hot-melt PSA along with a suitable tackifier and a process oil.

Absorbent article with adhesive strip

A hot melt composition is used to form a closure liner, e.g. the circular, integral, gasket-like member adhered to the periphery of a circular top or closure for a food jar or the like. The hot melt composition is selected to have, in the solid state, sufficient deformabilty, resiliency, hardness, lubricity, and other requirements of closure liners. It has been found that silicone oil, used in a concentration of about 1-8% by weight of the total hot melt composition can provide a high degree of lubricity, similar to the type of lubricity in self-lubricated plastic bearings. The remainder of the hot melt system or composition generally comprises a rubbery block co-polymer (serving as a film former), a hydrocarbon wax, a hydrocarbon oil, and, if desired, a thermoplastic vinyl arene polymer such as poly(methylstyrene). To apply the hot melt composition to the closure, the hot melt is poured on in a molten or flowable state, and this flowable state is maintained, so that the resulting deposit of hot melt composition seeks its own level under the influence of gravity.

Hot melt container closure sealant

The disclosed heterogeneous hot-melt sealant system is particularly well suited to sealing the typical tongue-and-groove joint between the base and cover of a burial vault. The hot-melt system comprises a plurality of layers, each layer being a distinct phase which resists chemical or morphological penetration (e.g. paraffin oil migration) from the adjacent layer. The layers are typically applied to the groove in the cover for the vault by individual casting or pouring of each of a plurality of hot-melt compositions in the molten state. Each hot-melt composition comprises an essentially amorphous polypropylene, a hydrocarbon resin (e.g. synthetic terpene resin), and a hydrocarbon (e.g. paraffin) oil. The first (bottom) poured hot-melt contains more polypropylene and less oil and terpene resin than the second (upper) pour. The plurality of layers co-operate to provide a variety of properties including fast sealing (even at low temperatures) and low temperature flexibility (primarily contributed by the upper pour) and good long-term hydrostatic pressure resistance (primarily provided by the bottom pour).

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North Oaks, MN, United States of America

James A Collins