1. Field of the Invention
This invention relates to textiles containing polyester fibers and particularly relates to compositions which can impart soil-release properties to polyester fibers after application to the textile and curing. It specifically relates to compositions which are partially esterified interpolymers of maleic anhydride for use as soil release finishes.
2. Description of the Prior Art
Synthetic fiber-containing clothing has brought great changes in the textile industry, partly because these clothes can retain an initial crease and partly because they can be washed with water. Additional crease-retention is generally imparted by treating the textile, before manufacture of the clothing, with resins and curing the resin on the textile after creasing and pressing as desired, thereby providing the so-called "wash-and-wear" and "durable press" clothing so plentiful in the clothing industry. However, clothing articles which contain polyester fibers also have the disadvantage of more readily picking up soil, and especially oily soil, than does natural-textile clothing. Moreover, when washed in a home washing machine, the polyester-containing clothing may become progressively more heavily soil-laden with successive washings because soil which is dispersed in the wash water redeposits onto the washed clothing before the end of the wash cycle.
The oleophilic and hydrophobic properties of linear polyester fibers, which are normally blended with cellulosics such as cotton and rayon, are responsible for this redeposition behavior. These polyester fibers actually seem to scavenge oily soil from the wash water. Aminoplast resins used in durable press finishing also have a tendency to retain oil-and water-borne stains. The combination of fairly high resin loads and high polyester content creates a serious soil retention problem for durable-press garments and other textile articles.
This behavior of polyester-containing textiles and several attempts to solve the problem are discussed in considerable detail in U.S. Pat. No. 3,377,249. In general, these prior attempts to improve the soil-resisting properties of polyester-containing cellulosic fabrics have used nitrogen-containing resins to impart hydrophilic qualities to the polyester fibers. The above-mentioned patent also discloses the application of aminoplast resins, in combination with a catalyst and a synthetic acid-emulsion polymer based on arcylic acid, to a textile which contains linear polyester fibers, whereby soil-release and durable-press characteristics are imparted thereto. However, these new developments have not completely solved the problem.
Several textile finishing compositions which counteract the soil-retention tendency of polyester-containing fabrics are now on the market. The two leading commercial types of soil-release textile finishes are the acrylic-emulsion type, such as Rhoplex SR-488, and the fluorocarbon-based type, such as 3M Scotchgard. The composition of the instant invention forms a third and advantageous type.