An ink-printed substrate web is broadly used in various consumer products. For example, in personal care products such as disposable garments, it is often desired to provide graphic designs printed with an ink on the outside of the disposable garment to enhance the aesthetic appearance and the consumer acceptance and to make the diaper look more like a conventional baby garment. For this purpose, an ink-printed substrate web, which could be a polymeric film or a nonwoven fibrous web, is used for the outermost layer of the disposable garment.
One problem of the ink-printed substrate web is poor ink rub-off resistance. Ink rub-off is typically caused by abrasion of the ink with other substances such as clothes of the wearer of a disposable garment, a carpet on the floor or the like. One method of solving this problem is to print the graphics on an inner substrate web such as a film or a nonwoven to be covered by an outer substrate web. As the printed surface of the inner substrate web is covered with the outer substrate web, the printed graphic on the inner substrate web does not get abraded directly with other contacting substrates and ink rub-off does not occur. While the substrate web covering the printed surface of the inner substrate web contributes to reduce the abrasion of the printed surface, the outer substrate web tends to hide the graphics printed on the inner substrate web to make the graphics to have hazy appearance. The fibers in a nonwoven if a nonwoven is used for the outer substrate web appear very distinctively on the printed graphics when covering a dark colored graphics. This also limits the vivid color expression of the graphic.
Yet another way of circumventing the problem of ink rub-off is to put the printed surface inside and the non-printed surface outside such that the printed surface is not abraded. In this case, however, the substrate web itself printed with the graphics tends to hide the graphics. Thus, there is a need for an ink-printed substrate web having an ink-printed surface which can be exposed to abrasion, yet exhibiting good ink rub-off resistance.
Attempts have been made to improve ink rub-off resistance on a substrate web, e.g., in U.S. Pat. No. 5,458,590 issued on Oct. 17, 1995 to Schleintz et al. titled “INK-PRINTED, LOW BASIS WEIGHT NONWOVEN FIBROUS WEBS AND METHOD”, U.S. Pat. No. 5,695,855 issued on Dec. 9, 1997 to Yeo et al. titled “DURABLE ADHESIVE-BASED INK-PRINTED POLYOLEFIN NONWOVENS”, and U.S. Pat. No. 5,853,859 issued on Dec. 29, 1998 to Levy et al. titled “ROOM TEMPERATURE LATEX PRINTING”. However, the existing art may not provide all of the advantages and benefits of the present invention.