US 4,136,699 AGranted

Absorbent article with adhesive strip

AssigneeH. B. Fuller Company

InventorsJames A. Collins, Thomas H. Quinn

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Abstract

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.

Claims7

Dependent claims

In an article for absorbing fluids, the structure comprising:

(a) an elongated absorbent pad having essentially two major surfaces;
(b) an outer layer in adherent contact with at least one of said two major surfaces;
(c) a hot-melt pressure sensitive adhesive layer adhered to the outwardly facing surface of said outer layer, said hot-melt pressure-sensitive adhesive having a viscosity of 500 to 15,000 centipoise at its pour temperature, said pour temperature ranging from about 300.degree. to about 400.degree. F., said hot-melt pressure-sensitive adhesive comprising:
(i) 10-20% by weight of a rubbery copolymer selected from the group consisting of a radial block-copolymer, an A-B-A block copolymer, and mixtures thereof, said radial block copolymer being a teleblock copolymer comprising molecules having at least three polymerized butadiene branches radially branching out from a central hub, each said branch having polystyrene terminal blocks;
said A-B-A block copolymer having polystyrene end blocks and a rubbery, essentially saturated, poly(mono-olefin)-like midblock,
(ii) more than 120 but less than 500 parts by weight, per 100 parts by weight of said rubbery copolymer of an essentially hydrocarbon oil selected from the group consisting of naphthenic oils, paraffinic oils, and mixtures thereof;
the amount of said oil in said hot-melt pressure-sensitive adhesive composition being within the range of 15 to 40% by weight;
(iii) more than 250 but less than 500 parts per 100 parts by weight of said rubbery copolymer, of terpene tackifier resin;
the amount of terpene tackifier resin in said composition being within the range of 40 to 60% by weight.

6 more elements

A hot-melt pressure-sensitive adhesive composition having a Brookfield viscosity ranging from about 500 to 15,000 centipoise at the pour temperature, said pour temperature ranging from about 300.degree. to about 400.degree. F., said composition being substantially free of solvents with a boiling point below 200.degree. C. at atmospheric pressure and consisting essentially of:

(a) 10-20% by weight of a rubbery A-B-A block copolymer having polystyrene end blocks and a rubbery, essentially saturated, poly(mono-olefin)-like midblock, said A-B-A block copolymer being at least partially incompatible with terpene tackifying resins, said A-B-A block copolymer having a modulus at 300% extension of at least about 500 p.s.i. and an ultimate tensile strength in excess of about 2,000 p.s.i.;
(b) from about 300 to about 400 parts by weight, per 100 parts by weight of said A-B-A block copolymer, of terpene tackifier resin;
the amount of said terpene tackifier resin in said composition ranging from 40 to 60% by weight;
(c) from about 150 to about 350 parts by weight of an essentially hydrocarbon oil selected from the group consisting of naphthenic oils, paraffinic oils, and mixtures thereof;
the amount of said essentially hydrocarbon oil in said composition ranging from 15 to 40% by weight;
said pressure-sensitive adhesive composition having a measurable 500% modulus at 23.degree. C., being resistant to cohesive failure in P.S.T.C.-1 180.degree. peel strength tests throughout the aforementioned range of essentially hydrocarbon oil content, and exhibiting P.S.T.C.-1 values in excess of about 4 pounds per inch width.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/760,831Filed 21 Jan 1977 · continuation in part
Priority: 27 Jun 1975
Granted: 30 Jan 1979
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

A61F 13/5611
Specially adapted for sanitary napkins or the like: using fastening strips, e.g. adhesive, on the undergarment-facing side
A61L 15/585
Adhesives: mixtures of macromolecular compounds
C09J 153/025
Vinyl aromatic monomers and conjugated dienes: modified
A61F 13/58
Supporting or fastening means: adhesive tab fastener elements