REACTIVE ANTIOXIDANTS, PREPOLYMERS CONTAINING ANTIOXIDANTS, AND THEIR COMPOSITIONS Russian patent published in 2019 - IPC C08G75/06 C08K5/375 C08L81/02 C08L81/04 C09J181/02 

FIELD: chemistry.

SUBSTANCE: invention relates to a reactive antioxidant, to an aerospace sealant composition, as well as to a sealing method. Reactive antioxidant is a reaction product of polythiol and an antioxidant-containing precursor containing at least one group which is reactive with respect to thiol groups, and at least one antioxidant group, and has formula (1a), or formula (1b), or formula (1c), or combinations thereof, where each k independently represents number from 1 to 10 in formula (1a), each k independently represents number from 0 to 10 in formulas (1b), (1c), at least one k in formula (1b) or (1c) is not equal to 0; each R⁶ is hydrogen or contains a group having a terminal reactive group; each R³ independently contains a group of formula (2) below, in which n is integer from 0 to 60; each R¹ independently contains C_2-10 alkanediyl, C_6-8 cycloalkanediyl, C_6-10 alkanecycloalkanediyl, C_5-8 heterocycloalkanediyl or -[(-CHR-)_p-X-]_q-(-CHR-)_r-; where p is integer from 2 to 6; q is integer from 1 to 5; r is integer from 2 to 10; each R independently contains hydrogen or methyl; and each X independently contains -O- or -S-; each R² independently contains C_1-10-alkanediyl, C_6-8-cycloalkanediyl, C_6-14-alkancycloalkanediyl or -[(CHR-)_p-X-]_q-(-CHR-)_r-, where p, q, r, R and X are as defined for R¹; m is integer from 0 to 50; each -L'- is obtained from antioxidant-containing precursor L, where the antioxidant precursor L contains an antioxidant group and at least one group which is reactive with respect to the thiol group; B is a nucleus of z-valent polyfunctionalising agent B(-V)_z, where z is integer from 3 to 6; each -V is a group containing a terminal group which is reactive with respect to the terminal thiol group; each -V'- is obtained by reaction of -V with a thiol group; and R⁷ is {-V’-}{R⁶-S-[-R³-S-L’-S-]_k-R³-S-V’-}_z-1B. Sealant composition contains said antioxidant and a sulfur-containing prepolymer. Part sealing method consists in that, first, said composition is obtained and applied on at least part of the part. Then, curing is performed.

R⁶-S-[-R³-S-L’-S-]_k-R³-S-R⁶ (1a) {R⁶-S-[-R³-S-L’-S-]_k-R³-S-V’-}_zB (1b) {R⁷-S-[-R³-S-L’-S-]_k-R³-S-V’-}{R⁶-S-[-R³-S-L’-S-]_k-R³-S-V’-}_z-1B (1c) -R1-[-S-(CH2)2-O-(R2-O)m-(CH2)2-S-R1-]n- (2)

EFFECT: invention enables to obtain a sealant composition having high heat resistance.

19 cl, 1 tbl, 9 ex