2results about How to "Reduce whiteness" patented technology

The invention discloses raw white two-side offset paper and a preparation method thereof, and belongs to the technical field of papermaking, and the method comprises the following steps: taking long-fiber paper pulp with ISO whiteness of 89-90%, short-fiber paper pulp with ISO whiteness of more than or equal to 89% and chemithermomechanical pulp with ISO whiteness of more than or equal to 77% as fiber raw materials, pulping, mixing 10-30wt% of long-fiber paper pulp, 55-80wt% of short-fiber paper pulp and 15-30wt% of chemithermomechanical pulp, and carrying out extrusion molding to obtain the raw white two-side offset paper. Mixed slurry is obtained; adding a purple dye, a blue dye, a yellow dye and a red dye into the mixed slurry according to a color mixing principle and a preset formula to obtain the mixed slurry added with the dyes; and sequentially carrying out sizing, net part forming, dehydration, pre-drying, surface sizing and post-drying on the mixed slurry added with the dye to obtain the raw white two-side offset paper. According to the method, the raw white two-side offset paper meeting the national standard eye protection requirement can be prepared, the pulp supply is more stable, and the product quality is more stable.

This invention provides a method for preparing and applying a trifluoromethoxyamide-bridged aromatic amine compound. The preparation method utilizes a continuous flow reaction system comprising two continuous flow reaction units connected in series, namely reaction unit A and reaction unit B. An amidation reaction is carried out in reaction unit A, and a reduction reaction is carried out in reaction unit B. The prepared trifluoromethoxyamide-bridged diamine compound exhibits high purity and whiteness and can be used to prepare polyimides for various electrical and optical components.