Patent ID: 7846984

Claim:
A method for recycling an ultraviolet curing resin that is in a colored, uncured state, the method comprising: collecting a mixture of uncured ultraviolet curing resin comprising at least one photo initiator and an organic composition comprising a coloring substance; than that of the ultraviolet decoloring the collected mixture by irradiating the mixture with light of a wavelength in the vicinity of the maximum absorption wavelength of the coloring substance; and collecting an ultraviolet curing resin that is in a decolored, uncured state; wherein the maximum absorption wavelength of the photo initiator (λ 1 ) and the maximum absorption wavelength of the coloring substance (λ 2 ) satisfy the following expressions: λ1<λ2 λ1>420 nm; and wherein a wavelength of light that is irradiated for decoloring (λ 3 ) and the wavelength λ 2 satisfy the following expression: (λ2−40) nm≦λ3≦(λ2+80) nm.