Method using coating technology to prepare solution-method phenolic aldehyde prepreg

Abstract

The invention relates to a method using the coating technology to prepare solution-method phenolic aldehyde prepreg. The method includes: performing suction filtration pretreatment on a phenolic resin solution to discharge the solvent in the phenolic resin solution; using a coating machine to evenly coat a high-temperature-resistant plastic film with resin after pretreatment, and thermally drying to form a resin film; covering the upper surface and the lower surface of fiber fabric with the resin film through continuous operations, and performing rolling compaction to obtain the phenolic aldehyde prepreg. The method has the advantages that the phenolic aldehyde prepreg prepared by the method is excellent in comprehensive performance, the resin content and the volatile matter content, lower than 1.5%, of the prepared phenolic aldehyde prepreg are easy to control as compared with those of traditional solution-method prepreg, the viscosity and process operability of the prepared phenolic aldehyde prepreg are equivalent to those of prepreg prepared by a hot-melt method, the whole cloth surface is smooth and flat, fit, free of bubbles and the like, and the prepared prepreg is especially applicable to an automatic discharge machine; in addition, the equipment cost of the used coating machine is 1/3-1/2 of that of an impregnator used in the hot-melt method, production energy consumption of the method is greatly lower than that of a solution method, high production efficiency is achieved, and accordingly the production cost of the finished product can be lowered evidently.

Description

technical field [0001] The invention relates to a method for preparing a phenolic prepreg, in particular to a method for preparing a solution-process prepreg by using glue coating technology, and belongs to the technical field of composite material preparation. Background technique [0002] Prepreg is a composite intermediate material made of fiber or fabric as a reinforcing material by impregnating a resin matrix. Its preparation method can be divided into two types: solution method and hot melt method according to the state of the resin used. The solution method is a process in which the fabric is impregnated with a resin solution containing a solvent, and the solvent is volatilized by heat treatment to make the resin have a certain degree of curing. Its advantages are simple equipment, low cost, and good adaptability. It is difficult to control the physical properties such as resin content and volatile matter content in the impregnation material, the process operability i...

AI Technical Summary

Problems solved by technology

On the one hand, this has led to limitations in the selection of resin-modified additives. For example, inorganic additives such as APP (ammonium polyphosphate) without surface modification have poor compatibility with alcoholic solvents and cannot be used together; It directly affects many final properties of prepregs. For example, the volatile content of solution-processed phenolic prepregs is generally between 4 and 6%. In order to ensure the performance of subsequent composite materials, vacuuming is also required during curing molding. To remove gas volatiles in the material, and when the volatile content is lower than 4%, the prepreg surface is dry and hard, non-sticky, and the process operability is poor

In addition, the amount of volatile matter will also affect the viscosity of the prepreg, which in turn affects its efficiency during use

In order to better expand the scope of material selection of phenolic resin modified additives, control the stability of the relevant physical properties of phenolic prepregs, and improve its operability, in order to achieve high comprehensive performance and technological There is an urgent demand for prepreg products with strong operability and low cost. Obviously, the phenolic prepreg prepared by the solution method cannot meet the needs.

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