Defoaming kettle and defoaming method for preparing polyamide acid resin

Abstract

The invention discloses a defoaming kettle and a defoaming method for preparing polyamide acid resin. A thin layer distributor with an arch rotary curve surface is fixedly installed in a defoaming kettle tank body; the distance from the curve surface arch top of the thin layer distributor to the lower end opening of a feeding pipe ranges from 0.01mm to 1/3 of the height of the tank body; the clearance between the lower edge of the curve surface of the thin layer distributor and the inner wall of the tank body is 0.01mm-10mm; the rotary curve surface of the thin layer distributor is a spherical surface; a resin conveying pipeline between a reaction kettle and the defoaming kettle is provided with a metering pump; the tank body is provided with a sandwiched sleeve, and an heat conduction medium inlet and outlet are formed at the top and bottom of the tank body. The defoaming method comprises the step that resin entering the defoaming kettle falls on the arch top of the curve surface of the thin layer distributor, and disperses and flows downward along the curve surface of the thin layer distributor to form a thin layer which results in bubble breakage. The metering pump is used for adjusting the flow rate of resin so as to keep that the thickness of the resin solution layer on the thin layer distributor is less than 5mm. Defoaming is completed immediately when resin is conveyed completely, and then pressurization is carried out for discharging. During defoaming, a heat conduction medium is introduced for warming, and negative pressure is kept in the tank body. According to the invention, defoaming is complete, and the defoaming time is shortened greatly so as to guarantee subsequent continuous film preparation. The defoaming kettle is simple in structure and convenient to operate.

Description

technical field [0001] The invention relates to a synthesis technology of polyamic acid resin, in particular to a defoaming kettle and a defoaming method for producing polyamic acid resin. Background technique [0002] Polyimide film is a polymer material with excellent properties such as high strength, high toughness, wear resistance, high temperature resistance, and corrosion resistance. It is the main insulating material for making various medium and high-end electrical and electronic components, and is widely used in electrical and electronic industry. [0003] At present, the production process of polyimide film is to use polyamic acid resin solution as raw material, and salivate on a salivating machine to obtain a self-supporting polyamic acid thick film, and then heat stretching, imidization, cooling and setting to obtain a polyimide film. imide film. [0004] With the design requirements of light, thin, short, small and high reliability of downstream application pr...

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Problems solved by technology

[0007] In addition, there is a Chinese utility model patent "resin vacuum defoaming mixer" with the patent number 201220275415.6, and a Chinese invention patent application "rapid defoaming device" with the patent number 201110167565.5, but the existing design can only shorten the defoaming time. It is difficult to remove microscopic or nanoscale microbubbles

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