Superabsorbent water sensitive multilayer construction

#The invention is directed to a superabsorbent multilayer construction.

#Superabsorbent polymers, which are available as powders, particles, and aqueous compositions, absorb large quantities of water and are often used in absorbent articles to increase the absorbency of the article. Disposable diapers and feminine hygiene products often include superabsorbent polymers to enhance body fluid absorption. Superabsorbent polymers also have various applications in the medical, food, and agricultural industries.

#In one aspect, the invention features a multilayer construction that includes a first layer including water sensitive thermoplastic polymer, and a second layer disposed on the first layer, the second layer including superabsorbent polymer. In one embodiment, the thermoplastic polymer includes polyamide. In another embodiment the thermoplastic polymer includes the reaction product of polyoxyalkylene glycol diamine and an acid selected from the group consisting of dicarboxylic acid, dicarboxylic acid ester, and combinations thereof, the polyoxyalkylene glycol diamine having the formula NH2—(CH2)x—(OCH2—CH2)y—O—(CH2)x—NH2, where 2≦X≦3, and 1≦Y≦2. In other embodiments, the thermoplastic polymer includes the reaction product of adipic acid and polyoxyalkylene glycol diamine. In another embodiment, the thermoplastic polymer is water soluble.

#FULATEX PD8081H aqueous polyacrylic acid solution polymer and ammonium zirconyl carbonate composition (H. B. Fuller Company, St. Paul, Minn.) was coated onto a 50 um thick NP 2116 polyamide film (H. B. Fuller Company) and dried to form a film construction that included a 15 um superabsorbent polymer coating on the 50 um polyamide film.

#Water droplets were dropped onto the superabsorbent polymer surface of the film construction using an eye dropper. The treated film was observed. The water was rapidly adsorbed and then absorbed by the superabsorbent polymer and formed a gel in five seconds. The water was then absorbed by the thermoplastic layer of the film construction. After three minutes the film construction had dissolved in the location of the water droplets.

#Other features are present in the claims.