Extractant and extraction method for removing color-expressing foreign substances from colored polymer containing ester functional group, and method for chemically selecting polymer containing ester functional group from colored polymer mixture

A method for selectively removing disperse dye from a colored polymer containing an ester functional group, comprising:

• heating an extractant to a temperature of 70° C. to 200° C. and bringing the extractant into direct contact with the colored polymer containing the ester functional group, thereby eluting the disperse dye from the colored polymer;
• and
• wherein the colored polymer comprises a mixed resin including a polymer resin containing an ester functional group and at least one additional component selected from polyethylene, polypropylene, polystyrene, polyvinyl chloride, cotton, linen, wool, rayon, acetate, acrylic, nylon, and spandex;
• and
• wherein the extractant comprises one or more compounds represented by at least one of Formula 1 or Formula 2,
• wherein, in the course of the contact with the extractant, the disperse dye is selectively extracted from the colored polymer containing the ester functional group;
• wherein, in Formula 1,
• A1 is selected from among a carboxy group, an aldehyde group, and a nitrile group,
• R1 is any one selected from among hydrogen, a hydroxy group, an ether group, an aldehyde group, a carboxy group, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 4 to 6 carbon atom, and an aryl group having 6 to 12 carbon atoms, the m is any one integer selected from 0 to 5,
• when m is 2 or greater, each R1 is the same or different,
• n is any one integer selected from 1 to 6,
• when n is 2 or greater, each A1 is the same or different, wherein, in Formula 2,
• A2 is at least one selected from among an ether group and a carbonyl group, R2 is an alkyl group having 1 to 10 carbon atoms,
• n is any one integer selected from 1 to 6, wherein when the n is 2 or greater, A2 and R2 is each independently the same or different,
• and other definitions of R1 and m are same as those in Formula 1 above.