Preparation method
(1) Preparation of acrylic prepolymer. Benzoyl peroxide was evenly mixed with styrene, methacrylic acid and methyl acrylate in proportion, and 20% of the mixture was added to the four-mouth flask with butanol, evacuated and filled with N, and the temperature was raised to 93℃. The remaining 80% of the mixture was uniformly added with a balanced feeding funnel within 5h, and kept warm for 2h to make it fully polymerized, and a transparent and viscous prepolymer was obtained for use.
(2) Preparation of epoxy acrylic emulsion. Epoxy resin, bisphenol A, ethylene glycol monobutyl ether and n-butylamine were added to the four-way flask in proportion, evacuated and filled with N, then heated up, and the reaction temperature was maintained at 150℃ for 2h, until the epoxy value of the reactants was reduced to a certain degree, acrylic prepolymer was added, and the temperature was adjusted to 94℃. When 40% dimethylethanolamine was added to hold for 3h, the reactants changed from cloudy to white and the viscosity increased. Then add the remaining dimethylethanolamine and water and stir thoroughly for 40min to form a uniform and stable emulsion.
(3) Preparation of thermochromic materials. Take CuCl·2H,0, CoCl· 6H,0, MgClg·6H,0 and mix well, dissolve in a small amount of water, add ethanol, stir and add. Al,0,(for chromatographic purposes), dried at 100℃ and ground.
Its color change is: light yellow (24℃)×→ yellowish green (45℃)×→ emerald green (91℃)×→ grassy green (95℃).
(4) Preparation of epoxy acrylic thermochromic paint. The deionized water is first put into a high-speed mixer, and the dispersant and part of the defoamer are added under low speed mixing. After mixing evenly, the discolored material is poured into the vortex created by the impeller; Increase the rotational speed of the impeller, add thickening agent, film forming agent and anti-mold agent, stir for 30min, disperse evenly, slowly add epoxy acrylic emulsion and remaining defoamer at low speed, and adjust the pH value to 8~9; Add water or thickener, adjust viscosity, sieve, discharge.
[Properties] The epoxy acrylic acid coating with excellent performance of environmentally friendly epoxy acrylic acid emulsion as the main film forming material, the inorganic thermal discoloration material dispersed in the epoxy acrylic acid resin, the epoxy acrylic acid thermal discoloration coating made of excellent performance, little pollution, obvious effect of heat discoloration.
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