| 摘要 |
PROBLEM TO BE SOLVED: To obtain a composition improving the coatability and adhesiveness of a polyolefin resin by preparing a copolymer resin by graft-copolymerizing a specific amount of anα,β-unsaturated carboxylic acid to a propylene-butene- ethylene copolymer having a specific molecular weight to lower and control a number average molecular weight to a specific value and dissolving the resin to an organic solvent in order to give a specific concentration. SOLUTION: Anα,β-unsaturated carboxylic acid (its derivative) (e.g. maleic acid anhydride) is graft-copolymerized to a propylene-butene-ethylene copolymer whose number average molecular weight is 20,000-30,000 or is reduced to 20,000-30,000 before the graft-copolymerization if it is not less than 20,000-30,000, which copolymer preferably contains 55-85 mol.% of propylene, 5-40 mol.% of butene and 1-10 mol.% of ethylene to obtain a graft-copolymer whose number average molecular weight is lowered and controlled to 3,000-16,000, preferably 4,800-16,000. The graft-copolymer is dissolved to an organic solvent (e.g. toluene) to give a solid content concentration of not less than 10 wt.%.
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