Water-borne, water redispersible, laminating adhesives for nonwoven applications

摘要

A specific class of water-borne, water redispersible laminating adhesives is disclosed which is desirable for bonding nonwoven substrates to themselves or to other substrates. The adhesives provide improved bond strength and improved water redispersibility when compared to laminating adhesives currently used for the same purpose. Furthermore, the novel adhesives are much less sensitive to the presence of significant levels of plasticizer than are laminating adhesives currently used, which exhibit reduced water redispersibility when such plasticizers are present in significant amounts. The novel laminating adhesives contain an aqueous styrene/acrylic polymer dispersion prepared by radical-initiated emulsion polymerization of unsaturated monomers in the presence of starch degradation products having a weight average molecular weight range of from about 2500 to 25000 and which are obtainable by hydrolysis in the aqueous phase. The adhesives may contain only the starch-modified, styrene/acrylic polymer dispersion, or may further include other components, such as plasticizers and/or rheology modifiers, when required. The novel adhesives are particularly useful in disposable articles wherein a nonwoven substrate is bonded to a second substrate via a water-borne, laminating adhesive. The disposable articles may include an absorbent core portion disposed between and proximate the nonwoven and second substrate.