HOT MELT EPOXY BINDER WITH INCREASED MOISTURE RESISTANCE Russian patent published in 2023 - IPC C08L63/00 C08K5/21 C08K5/31 C08K5/16 

FIELD: polymer products.

SUBSTANCE: creating epoxy binders for semi-finished products (prepregs) to obtain structural polymer composite materials (PCM) based on fibrous fillers with energy-efficient curing modes and increased moisture resistance, which can be used in aviation, auto, machine and shipbuilding industries and other branches of industry. Hot melt epoxy binder for semi-finished prepregs consists of the following components, in the following amounts, wt.%: epoxy nitrogen-containing polyfunctional resin 35.0-65.0, liquid epoxy resin based on bisphenol A 20.0-45.0, isocyanate 2.5 -10, thermoplastic 1.0-7.0, latent curing agent - dicyandiamide 3.0-7.0, accelerator - asymmetrically disubstituted urea 0.6-2.5.

EFFECT: creation of a melt epoxy binder with increased moisture resistance, capable of curing at low curing temperatures (not more than 130°C) with improved process characteristics (high level of preservation of rheological characteristics during processing into prepreg and its viability at storage temperatures up to 25°C), which provides a high degree of curing and an increase in the degree of retention of the strength characteristics of the cured matrix, which is operated in moisture-saturated conditions at elevated temperatures, and is also characterized by optimal viscosity and fluidity, which will make it possible to obtain prepregs based on it, suitable for molding PCM with low porosity and low coefficient of variation of physical and mechanical characteristics.

4 cl, 2 tbl, 12 ex