Direct melt-spun full-matte high-viscosity pet/low-viscosity pet two-component elastic fiber and preparation method therefor

A liquid titanium dioxide matting agent, used for a full-matte PET two-component elastic fiber, the PET two-component elastic fiber containing a first PET component and a second PET component, the viscosity of the first PET component and the second PET component being different, wherein, the liquid titanium dioxide matting agent is consisted of titanium dioxide and a carrier;

• the carrier is a linear polyester or a small molecule ester;
• each end of the linear polyester contains a carboxyl functional group or a hydroxyl functional group independently, and the molecular weight of the linear polyester is 1800˜2500;
• the small molecule ester has an ABA or BAB structure, where A is a dibasic acid, and B is a diol;
• the viscosity of the carrier is 2˜20 Pa·s at 25° C., and 1.0˜8.0 Pa·s at 60° C.;
• the small molecule ester has a melting point lower than or equal to 20° C., and a boiling point higher than or equal to 290° C.;
• the thermal weight loss of the carrier under nitrogen protection at 290° C. for 2.0 hours is less than or equal to 0.2%;
• in percent by weight, the liquid titanium dioxide matting agent contains 20%-50% of titanium dioxide and 50%-80% of the carrier.