Method for improving dielectric constant of polypropylene film

[0005] The present invention proposes a method for improving the dielectric constant of polypropylene film to solve the problem of agglomeration easily occurring in the prior art when fillers with high dielectric constant...

Described pre-dispersion treatment is: be 65-90 ℃ at temperature, magnetic stirring disperses 1-10min under the condition that power is 250-700W; The composite filler of spheroidization high dielectric constant after surface treatment is carried out pre-treatment Dispersion treatment can effectively improve the interfacial compatibility between the spheroidized composite filler and polypropylene, so that the spheroidized composite filler with high dielectric constant has better dispersion in polypropylene and avoids the problem of agglomeration ;

From the data records of table 1, it can be seen that the application is made of porcelain particles, barium titanate, carbon nanotubes, and titanium dioxide as composite fillers, and there is a synergistic effect between the components of composite utilization, which has better interaction force , can be neatly arranged in the polypropylene body and form a good overlap with each other. From the comparison of Comparative Example 3 and Example 4, it can be seen that a single component is difficult to reach the technical effect of the present application; Comparative Example 1 and Example 4 The comparison shows that the addition of spheroidized high dielectric constant composite fillers in the preparation of polypropylene can effectively improve the dielectric constant of polypropylene films, and the breakdown field strength is greater than 430KV/mm, and the dielectric loss is less than 10-4; from the comparative example 2. Comparative analysis with Example 4 shows that: the composite filler with high dielectric constant is spheroidized to obtain a spheroidized high dielectric constant composite filler with an average particle diameter of 95-270nm and an average pore diameter of 350-650nm. Reduce the probability of the composite filler forming a conductive channel in the polypropylene film and promote the dielectric constant of the polypropylene film; and the spheroidized high dielectric constant composite filler is surface-treated, pre-dispersed and then added to the polypropylene to form The system helps to improve the dielectric constant of the polypropylene film; by contrasting Example 4 and Comparative Example 5 with Example 4 respectively, it can be seen that: in the present application, the composite filler of spherical high dielectric constant is subjected to surface treatment and pretreatment can It can effectively improve the interfacial compatibility between the spheroidized composite filler and polypropylene, so that the spheroidized high dielectric constant composite filler has better dispersion in polypropylene and avoids the problem of agglomeration; Comparing ratio 6 with Example 4, it can be seen that after adding the coupling agent, setting the ultrasonic vibration can further reduce the probability of agglomeration of the mixed system of spherical high dielectric constant composite filler and polypropylene, which helps to improve the dielectric strength of the polypropylene film. constant.

In addition, described surface treatment is: add surface treatment agent in the composite filler of spheroidization high dielectric constant, stir 10-25min under the stirring speed of 100-250r/min, leave standstill; In the present embodiment Among them, the surface treatment agent is one or more of silane coupling agent, stearic acid, fatty acid and aminosilane; the composite filler with spheroidized high dielectric constant has a larger specific surface area, and the surface treatment can While enhancing its mechanical properties, it can further provide a transition layer for the combination between the spheroidized high dielectric constant composit...