Low-density, open-cell, soft, flexible, thermoplastic, absorbent foam and method of making foam

A soft, flexible, resilient, elastic, low-density, open-cell, thermoplastic, absorbent foam, comprising:

• a base resin, about 20% to about 50% by weight of a thermoplastic elastomer, and a surfactant;
• wherein the foam has an open cell content of greater than 55% and a fluid intake flux of about 1 ml/sec/in2 or greater upon a first insult, about 1 ml/sec/in2 or greater upon a second insult, and about 1 ml/sec/in2 or greater upon a third insult;
• the foam is soft and flexible, and has a compression resistance of about 20% compression set or less;
• and
• the thermoplastic elastomer is selected from the group consisting of styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-isoprene-butadiene-styrene (SIBS), styrene-ethylene/butylene-styrene (SEBS), styrene-ethylene/propylene-styrene (SEPS), polyolefin-based thermoplastic elastomers including ethylene α-olefin copolymers, hydrogenated butadiene-isoprene-butadiene block copolymers, stereoblock polypropylenes, ethylene-propylene-diene terpolymer (EPDM), ethylene-propylene random copolymers (EPM), ethylene propylene rubbers (EPR), thermoplastic polyether ester elastomers, ionomeric thermoplastic elastomers, polyamide thermoplastic elastomers, thermoplastic polyurethanes, and combinations thereof.

A soft, flexible, resilient, elastic, low-density, open-cell, thermoplastic, absorbent foam, comprising:

• between about 50% and 90% by weight, of a polystyrene base resin and between about 20% and about 50%, by weight, of a thermoplastic elastomer, wherein the thermoplastic elastomer has a styrenic block copolymer thermoplastic elastomer diblock content between about 50% and about 80% of a total weight of the thermoplastic elastomer;
• wherein the foam has an open cell content of greater than 55% and a fluid intake flux of about 1 ml/sec/in2 or greater upon a first insult, about 1 ml/sec/in2 or greater upon a second insult, and about 1 ml/sec/in2 or greater upon a third insult;
• the foam is soft and flexible, and has a compression resistance of about 20% compression set or less;
• and
• the thermoplastic elastomer is selected from the group consisting of styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-isoprene-butadiene-styrene (SIBS), styrene-ethylene/butylene-styrene (SEBS), styrene-ethylene/propylene-styrene (SEPS), polyolefin-based thermoplastic elastomers including ethylene α-olefin copolymers, hydrogenated butadiene-isoprene-butadiene block copolymers, stereoblock polypropylenes, ethylene-propylene-diene terpolymer (EPDM), ethylene-propylene random copolymers (EPM), ethylene propylene rubbers (EPR), thermoplastic polyether ester elastomers, ionomeric thermoplastic elastomers, polyamide thermoplastic elastomers, thermoplastic polyurethanes, and combinations thereof.

A method for producing a low-density, open-cell, thermoplastic, flexible, soft, absorbent foam, comprising the steps of:

• providing a foam polymer formula including a base resin, a plasticizing agent, a surfactant and about 20% to about 50% by weight of a thermoplastic elastomer;
• heating the foam polymer formula to create a polymer melt utilizing a blowing agent;
• foaming the polymer melt to a density of about 0.1 g/cm3 or less;
• and
• extruding the polymer melt to form an open-cell, soft, flexible, thermoplastic, absorbent foam;
• wherein the foam has an open cell content of greater than 55% and a fluid intake flux of about 1 ml/sec/in2 or greater upon a first insult, about 1 ml/sec/in2 or greater upon a second insult, and about 1 ml/sec/in2 or greater upon a third insult;
• the foam is soft and flexible, and has a compression resistance of about 20% compression set or less;
• and
• the thermoplastic elastomer is selected from the group consisting of styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-isoprene-butadiene-styrene (SIBS), styrene-ethylene/butylene-styrene (SEBS), styrene-ethylene/propylene-styrene (SEPS), polyolefin-based thermoplastic elastomers including ethylene α-olefin copolymers, hydrogenated butadiene-isoprene-butadiene block copolymers, stereoblock polypropylenes, ethylene-propylene-diene terpolymer (EPDM), ethylene-propylene random copolymers (EPM), ethylene propylene rubbers (EPR), thermoplastic polyether ester elastomers, ionomeric thermoplastic elastomers, polyamide thermoplastic elastomers, thermoplastic polyurethanes, and combinations thereof.