FIELD: chemistry.
SUBSTANCE: present invention relates to a sealing composition. Described is a sealing composition containing: (a) an isocyanate-terminal polythioether prepolymer, wherein said isocyanate-terminal polythioether prepolymer comprises the reaction product of reagents, including: (i) a polythioether polyol, wherein said polythioether polyol comprises the reaction product of reagents comprising a thiol-terminal polythioether prepolymer and hydroxy-functional vinyl ether selected from monovinyl triethylene glycol, 1,4-cyclohexanedimethyl monovinyl ether, 1-methyl-3-hydroxypropyl vinyl ether and 4-hydroxybutyl vinyl ether; where the thiol-terminal polythioether prepolymer includes a thiol-terminal polythioether prepolymer of Formula (23a), a thiol-terminal polythioether prepolymer of Formula (23b), and their combination: HS-R1-[-S-(CH2)p-O-[-R2-O-]m-(CH2)2-S-R1-]n-SH (23a), {HS-R1-[-S-(CH2)p-O-[-R2-O-]m-(CH2)2-S-R1-]n-S-V’-}z-B (23b), where: each R1 is independently selected from C2-10 alkandiyl, C6-8 cycloalkandiyl, C6-14 alkancycloalkandiyl and [(-CHR3-)s-X-]q-(-CHR3-)r-, where s is an integer from 2 to 6; q is an integer from 1 to 5; r is an integer from 2 to 10; each R3 is independently selected from hydrogen and methyl; and each X is independently selected from -O-, -S-; and each R2 is independently selected from C1-10 alkandiyl, C6-8 cycloalkandiyl, C6-14 alkancycloalkandiyl and -[(-CHR3-)s-X-]q-(-CHR3-)r-, where s, q, r, r3 and X have the same meanings as previously described for R1; m is an integer from 0 to 50; n is an integer from 1 to 60; p is an integer from 2 to 6; B is the core of a z-valent polyfunctionalizing agent B(-V)z, where z is an integer from 3 to 6; and each V is a fragment containing a terminal group capable of reacting with a thiol; and each -V'- is formed by the reaction of -V with a thiol; (ii) an aliphatic diisocyanate; and (b) a hardener, wherein said hardener comprises: (i) an aromatic amine, wherein said aromatic amine is selected from diethyltoluene diamine, dimethyltoluene diamine, and combinations thereof; and (ii) a polyfunctional silane, wherein said polyfunctional silane is selected from bis(triethoxysilylpropyl)amine, bis(triethoxysilylpropyl)tetrasulfide, and combinations thereof. Also a method for sealing a surface is described, in which the above composition is applied to a surface; and then the applied composition is cured and, thus, the surface has been sealed. Described is a cured sealant obtained from the above composition.
EFFECT: obtaining a fuel and water resistant sealant composition with improved strength and elongation values.
16 cl, 1 dwg, 8 tbl, 18 ex
