The invention relates to the technical field of
papermaking, in particular to a water-in-
oil emulsion type nano cross-linked
copolymer papermaking retention aid and a preparation method thereof. The water-in-
oil emulsion type nano cross-linked
copolymer papermaking retention aid comprises the following components: a water phase, an
oil phase and a
phase inversion agent, the
mass ratio of the water phase to the
oil phase is (7.2-7.5): (2.5-2.8), and the water phase comprises the following components in parts by weight: 10-15 parts of a template
polymer, 300-320 parts of
acrylamide, 80-120 parts of a cationic
monomer, 0.01-0.04 part of a structure
regulator, 200-300 parts of water and 0.1-0.5 part of an initiator; the
oil phase comprises the following components in parts by weight: 220-260 parts of
white oil and 25-35 parts of an emulsifier; the molecular weight of the template
polymer is 500,000-1,000,000, and the
retention rate of the filler and the strength of finished paper can be remarkably improved.