COVERING COMPOSITION OF POWDER MATERIAL Russian patent published in 2023 - IPC C08G63/91 C09D167/02 C09D175/04 

FIELD: chemistry.

SUBSTANCE: group of inventions relates to a covering composition of powder material, which can be cured at low temperatures, to a method for the manufacture of such compositions, to a method for coating of products, using mentioned compositions, and to the resulting coated products. The covering composition of powder material contains one or more cross-linked components and a catalyst, where one or more cross-linked components are cross-linked using a real Michael addition (hereinafter – RMA) reaction. In this case, the powder covering composition contains: a) cross-linked component A having at least 2 acid donor groups C-H in activated methylene or methine, b) cross-linked component B having at least 2 activated unsaturated acceptor groups C=C, which react with component A of RMA reaction, forming a cross-linked mesh, c) latent catalyst system C containing a precursor of a strong base for catalysis of RMA crosslinking reaction with a delay at a curing temperature below 200°C. The catalyst system C is a latent catalyst system LCC having chemical latency, containing components, which react at the curing temperature to initiate a delayed reaction between cross-linked components A and B. Moreover, the mentioned latent catalytic system LCC contains, in LCC1 implementation option: a) weak base C2, b) activator C1 reacting with C2 or protonated C2 at the curing temperature, where the activator C1 is selected from a group containing epoxy, carbodiimide, oxetane, oxazoline, or aziridine functional components, preferably epoxy or carbodiimide. The system contains, in LCC2 implementation option: a) weak base C2, which is a donor S2 in the Michael reaction, and b) activator C1, which is an acceptor S1 in the Michael reaction, containing an activated unsaturated group C=C, reacting with S2 at the curing temperature, wherein, in case if S1 is acrylate, S2 has pKa of conjugate acid below 8, wherein pKa is defined as a value in an aqueous medium, and, in case if S1 is methacrylate, fumarate, itaconate, or maleate, S2 has pKa of conjugate acid below 10.5. A method for preparation of a covering composition of powder material, a method for coating of substrate of powder material, products coated with a powder composition, the use of a catalyst system C for catalysis of a crosslinking reaction in RMA crosslinking coating compositions of powder material at curing temperatures below 200°C, RMA crosslinking polymer, and its use in RMA crosslinking coatings of powder material, polymer containing groups of weak base C2, and its use as a latent main component of a catalyst of a covering composition of powder material are also described.

EFFECT: provision of a powder coating composition, which is cured at low temperatures with a high curing rate to obtain acceptable short curing times, but nevertheless with a sufficiently long film setting time at edges to ensure fluidity and coalescence, as well as to achieve good film formation with a good coating appearance.

24 cl, 15 tbl, 37 ex