A kind of preparation method of low turbidity bisphenol A type cyanate ester prepolymer

Abstract

The invention discloses a preparation method of a low-turbidity bisphenol A type cyanate ester prepolymer. The preparation method of the low-turbidity bisphenol A type cyanate ester prepolymer comprises the steps that diphenol propane, cyan chloride and triethylamine are dissolved in a solvent for participating in a reaction, and recrystallization is carried out to obtain the low-turbidity bisphenol A type cyanate ester prepolymer; reaction liquid by vaporific injection is in fully contact with a catalyst in an internal atomization chamber through an atomization reaction device, the conversionrate of the bisphenol A type cyanate ester prepolymer is increased by 85-95%, and product turbidity and purification difficulty are effectively reduced; and a phase transfer catalyst is mixed with ethyl alcohol to form a catalyst for participating in a reaction, local polymerism taking the catalyst as the center cannot occur at an initiating stage, gels and solid particles cannot be formed, so that reactants are sufficiently in contact with each other, the reaction is more thorough, the turbidity of a reaction system is greatly reduced, the purification difficulty is further reduced, and theturbidity of the obtained bisphenol A type cyanate ester prepolymer is less than or equal to 5 FTU after detection, and is greatly superior to the standard of being less than or equal to 10 FTU in theprior art.

Description

technical field [0001] The invention relates to the technical field of polymer material synthesis, in particular to a method for preparing a low-turbidity bisphenol A type cyanate prepolymer. Background technique [0002] Bisphenol A cyanate resin is the most widely used cyanate resin on the market. The main reason for the high market share of this type of cyanate ester resin is that bisphenol A cyanate ester series products have the highest cost performance. Excellent heat resistance (Tg=290℃), excellent dielectric properties, very low dielectric constant (ε=2.64-3.11) and dielectric loss value ( tg=0.001-0.008), and has excellent mechanical properties and low hygroscopicity. Compared with thermosetting resin matrices such as phenolic resin, epoxy resin and bismaleimide that have been produced on a large scale, bisphenol A cyanate Resin has better overall performance. [0003] At present, the turbidity of bisphenol A cyanate is generally ≤10FTU. When the turbidity is hig...

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Problems solved by technology

But find through research, apply this method in the preparation of bisphenol A type cyanate ester prepolymer, still have following problem: (1) do not use the good solvent of solubility to dissolve diphenolic propane or cyanogen chloride After participating in the reaction, there are more by-products and low reaction yield. The small polar solvent causes a large number of products and by-products to precipitate, which greatly increases the difficulty of purification. After the bisphenol A cyanate monomer is purified, there is still a large turbidity. It is not conducive to the subsequent polymerization reaction, which reduces the quality of bisphenol A cyanate ester resin products; (2) in the trimerization reaction of bisphenol A cyanate ester monomers, the catalyst dilution rate is low and the dispersion is not ideal, resulting in catalyst and monomer Maintain a relatively high concentration, and the local polymerization phenomenon centered on the catalyst will occur in the initiation stage, forming gel and solid particles, greatly increasing the turbidity of the reaction system, and further increasing the difficulty of purification; (3) The catalyst cannot be mixed with the reaction during atomization. The liquid is fully sprayed out in the form of mist, so that the contact area of ​​the raw materials is small, and the reaction temperature cannot maintain a stable range, which is not conducive to the normal progress of the reaction.

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