US 4,935,022 AGranted

Thin absorbent articles containing gelling agent

AssigneeThe Procter & Gamble Company

InventorsGlen R. Lash, Leonard R. Thompson

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Abstract

The present invention provides absorbent articles, such as disposable diapers, which utilize a particular type of stiffened cellulose fibers and a particlar type and form of polymeric gelling agent particles to enhance the absorbency characteristics of such articles. In these articles, the gelling agent material, combined in particulate form of a certain size with stiffened cellulose fiber material, is primarily placed in a lower fluid storage layer of the absorbent core of the article. Such a fluid storage lower layer of the absorbent core is placed underneath an upper, generally larger, fluid acquisition/distribution layer which also contains stiffened cellulose fibers and gelling agent particles of a certain size. This lower fluid storage layer is generally positioned toward the front of the absorbent article. Absorbent articles of this type can be fashioned into especially thin, compact, nonbulky diapers.

Claims20

Dependent claims

A disposable absorbent article comprising:

(A) a liquid impervious, elongated backing sheet;
(B) a liquid pervious topsheet;
and
(C) a layered absorbent core positioned between said backing sheet and said topsheet, said core comprising:
(i) an upper fluid acquisition/distribution layer having a density of from about 0.05 to 0.25 g/cm.sup.3 and a basis weight of from about 0.01 to 0.10 g/cm.sup.2 and comprising a combination of stiffened, twisted, curled cellulose fibers, and from about 3% to 15% by weight of said upper layer of particles of a hydrogel-forming polymeric gelling agent thoroughly dispersed among said fibers;
and
(ii) a lower fluid storage layer having a density of from about 0.06 to 0.3 g/cm.sup.3 and a basis weight of from about 0.02 to 0.12 g/cm.sup.2 and comprising a combination of stiffened, twisted, curled cellulose fibers and from about 15% to 60% by weight of said lower layer of particles of a hydrogel-forming polymer gelling agent thoroughly dispersed among said fibers;
wherein in both upper and lower layers the hydrogel-forming polymeric gelling agent has an equilibrium gel volume of at least about 20 grams of synthetic urine per gram of gelling agent and wherein in the upper layer the gelling agent particles have a mass median particle size ranging from about 400 to 1680 microns;
said lower fluid storage layer having a top surface area which is from about 0.25 to 0.95 times that of said upper fluid acquisition/distribution layer and said lower fluid storage layer further being positioned relative to said backing sheet and said upper layer in a manner such that at least about 75% of the polymeric gelling agent in said lower layer is found within the front two-thirds section of said absorbent article and such that at least about 55% of the polymeric gelling agent in said lower layer is found within the front half section of said absorbent article.

6 more elements

A disposable absorbent article comprising:

(A) a liquid impervious, elongated backing sheet;
(B) a liquid pervious topsheet;
and
(C) a layered absorbent core positioned between said backing sheet and said topsheet, said core comprising:
(i) an upper fluid acquisition/distribution layer having a density of from about 0.05 to 0.25 g/cm.sup.3 and a basis weight of from about 0.01 to 0.10 g/cm.sup.2 and consisting essentially of an airlaid mixture of stiffened, twisted curled cellulose fibers;
and from about 3% to 15% by weight of said upper layer of particles of a hydrogel-forming polymeric gelling agent;
and
(ii) a lower fluid storage layer having a density of from about 0.06 to 0.3 g/cm.sup.3 and a basis weight of from about 0.02 to 0.12 g/cm.sup.2 and consisting essentially of an airlaid mixture of stiffened curled cellulose fibers and from about 15% to 60% by weight of said lower layer of particles of a hydrogel-forming polymer gelling agent;
wherein, in both upper and lower layers;
(a) the stiffened, twisted, curled cellulose fibers have an average dry fiber twist count of at least about 4.5 twist nodes per millimeter, an average wet fiber twist count of at least about 3.0 twist nodes per millimeter and which is at least about 0.5 twist nodes per millimeter less than the average dry fiber twist count, a curl factor of at least about 0.30, a water retention value between about 28% and 50% and an alcohol retention value of less than about 30%;
and
(b) the hydrogel-forming polymeric gelling agent has an equilibrium gel volume of at least about 20 grams of synthetic urine per gram of gelling agent and the gelling agent particles have a mass median particle size ranging from about 410 to 1190 microns with no more than about 16% by weight of said particles having a particle size less than 200 microns and no more than about 16% by weight of said particles having a particle size greater than 1410 microns;
said lower fluid storage layer having a top surface area which is from about 0.25 to 0.95 times that of said upper fluid acquisition/distribution layer and said lower fluid storage layer further being positioned relative to said backing sheet and said upper layer in a manner such that at least about 75% of the polymeric gelling agent in said lower layer is found within the front two-thirds section of said absorbent article and such that at least about 55% of the polymeric gelling agent in said lower layer is found within the front half section of said absorbent article.

10 more elements

A disposable absorbent article comprising:

(A) a liquid pervious, elongated backing sheet;
(B) a liquid pervious topsheet;
and
(C) a layered absorbent core positioned between said backing sheet and said topsheet, said core comprising:
(i) an hourglass-shaped upper fluid acquisition/distribution layer having a density of from about 0.07 to 0.12 g/cm.sup.3 and a basis weight of from about 0.013 to 0.020 g/cm.sup.2 and consisting essentially of an airlaid mixture of stiffened, twisted, curled cellulose fibers;
and from about 5% to 8% by weight of said upper layer of particles of a hydrogel-forming polyacrylate or polyacrylate grafted starch gelling agent;
and
(ii) a lower fluid storage layer having a density of from about 0.15 to 0.20 g/cm.sup.3 and a basis weight of from about 0.05 to 0.07 g/cm.sup.2 and consisting essentially of an airlaid mixture of stiffened curled cellulose fibers and from about 20% to 50% by weight of said lower layer of particles of a hydrogel-forming polyacrylate or polyacrylate grafted starch gelling agent;
wherein in both upper and lower layers
(a) the stiffened, twisted, curled cellulose fibers have an average dry fiber twist count of at least about 6.5 twist nodes per millimeter, an average wet fiber twist count of at least about 5.0 twist nodes per millimeter and which is at least 1.0 twist nodes per millimeter less than the average dry fiber twist count, a curl factor of at least about 0.5, a water retention value of from about 35% to 42% and an alcohol retention value of less than about 27%;
and
(b) the hydrogel-forming gelling agent has an equilibrium gel volume of from about 22 to 35 grams of synthetic urine per gram of gelling agent and the gelling agent particles have a mass median particle size ranging from about 410 to 1190 microns with no more than about 16% by weight of said particles having a particle size less than 210 microns and no more than about 16% by weight of said particles having a particle size greater than 1100 microns;
said lower fluid storage layer having a top surface area which is from about 0.25 to 0.75 times that of said upper fluid acquisition/distribution layer and said lower fluid storage layer further being positioned relative to said backing sheet and said upper layer in a manner such that at least about 90% of the gelling agent in said lower layer is found within the front two-thirds section of said absorbent article and such that at least about 60% of the gelling agent in said lower layer is found within the front half section of said absorbent article.

10 more elements

Dependencies are inferred from the claim text.