▎ 摘　　要

NOVELTY - Phase change thin film comprises aqueous emulsion, phase-change microcapsule, antifoaming agent, thickening agent, dispersant and heat-conducting filler. USE - Used as phase change thin film containing phase-change microcapsule. ADVANTAGE - The film: has small thickness (can be as thin as 70 microns) and controllable thickness, high tensile strength and adhesion, and high enthalpy value (up to 154 J/g); and satisfies the requirements of electronic product heat management. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: preparing the phase change film, comprising (i) preparing heat-conducting composite premix by uniformly mixing heat-conducting filler with phase change microcapsules to obtain heat-conducting composite premix, (ii) preparing phase change microcapsule film preparation liquid by uniformly mixing thickening agent, antifoaming agent and heat-conducting composite premix prepared in the step (i), then adding aqueous emulsion and uniformly mixing to prepare a phase-change microcapsule film preparation liquid, and (iii) using the phase-change microcapsule film preparation liquid prepared in the step (ii) to coat and form a film to obtain a phase-change film, preferably the average thickness of the coating film is 0.07 mm, preferably the method further comprises surface treatment step of heat-conducting filler comprising using a silane coupling agent as the dispersant to carry out surface treatment on the heat-conducting filler to obtain a surface-treated thermally conductive filler; a phase change thin film prepared by the above-mentioned method; and a phase-change composite film based on phase-change microcapsules, comprising a heat absorbing layer and a base material layer, where the heat absorbing layer comprises phase change film, and is formed on one side of the base material layer.