Patent ID: 8435631

Claim:
A vapor permeable microporous material in contact with a volatile material comprising: a vapor permeable microporous material which comprises (a) a matrix of substantially water-insoluble thermoplastic organic polymer comprising polyolefin; (b) finely divided, substantially water-insoluble particulate filler, said particulate filler being distributed throughout said matrix and constituting from 20 to 90 percent by weight, based on the total weight of said microporous material; and (c) a network of interconnecting pores communicating substantially throughout said microporous material; wherein said microporous material has, a volatile material contact surface in contact with a volatile material, a vapor release surface, wherein said volatile material contact surface and said vapor release surface are substantially opposed to each other wherein (i) at least a portion of said volatile material contact surface has a first coating thereon, and/or (ii) at least a portion of said vapor release surface has a second coating thereon, wherein said first coating and said second coating each independently have a coating weight of from 0.01 to 3.0 g/m 2 , and wherein said first coating and said second coating each independently are selected from a coating composition comprising poly(vinyl alcohol), and a volatile material transfer rate, from said volatile material contact surface to said vapor release surface, of at least 0.04 to 0.6 mg/(hour*cm 2 ), wherein upon exposure of said microporous material to a temperature increase of from 25° C. to 60° C., said volatile material transfer rate increases by less than or equal to 150 percent, and wherein upon transfer of the volatile material from said volatile material contact surface to said vapor release surface, said vapor release surface is substantially free of volatile material in liquid form.