PHENOLIC ANTIOXIDANTS IN CRYSTAL FORM Russian patent published in 2009 - IPC C07C67/52 C07C69/732 C07C231/24 C07C235/34 C08K5/13 C08K5/20 

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of preparing solid particles used as phenolic antioxidants and including in, in fact, crystal form compound of formula: in which one of R₁ and R₂ independently on each other represent hydrogen atom or C₁-C₄alkyl, and the other one represents C₃-C₄alkyl; x represents zero (direct bond) or number from one to three; and Y represents C₈-C₂₂alkoxy or groups of incomplete formulas

or in which one of R₁' and R₂' independently on each other represent hydrogen atom or C₁-C₄alkyl, and the other one represents C₃-C₄alkyl; x represents zero (direct bond) or number from one to three; y represents number from two to ten; and z represents number from two to six, in which homogeneous water dispersion is prepared, which includes compound (I) or mixture of such compounds, where R₁, R₂, R₁' R₂', Y, x, y and z have values given above, by addition of incomplete ether of fatty acid polyoxyethylene sorbitan and inoculating crystals, and obtained crystals are separated from dispersion and process is carried out until solid particles are obtained. Invention also relates to novel crystal forms pentaerythrite tetrakis-[3-(3,5-ditret-butyl-4-hydroxyphenyl)propionate], (µ-form) of pentaerythrite tetrakis 3-(3,5-ditret-butyl-4-hydroxyphenyl)propionate], crystal form of N,N'-hexane-1,6-diyl-bis-[3-(3,5-ditret-butyl-4-hydroxyphenyl propionamide)], crystal form of N,N'-hexane-1,6-diyl-bis-[3-(3,5-ditret-butyl-4-hydroxyphenyl propionamide)] and crystal modification (β-form) of N,N'-hexane-4,6-diylbis-[3-(3,5-ditret-butyl-4- hydroxyphenyl propionamide)].

EFFECT: elaboration of improved method of preparing solid particles used as phenolic antioxidants.

10 cl, 2 ex