FIELD: chemistry.
SUBSTANCE: described sealing cap comprises: a preformed, at least partially cured, first sealant composition forming a shell 1/32 to 1/4 inch thick or 1/2 inch thick; and at least partially uncured composition of the second sealant filling the noted shell, wherein the first sealant composition and the second sealant composition comprise: (i) a polythioether having end thiol groups including a polythioether having terminal thiol groups of a formula (II), a polythioether of a formula (III), or their combination: HS-R1-(-S-(CH2)2-O-[-R2-O-]m-(CH2)2-S-R1-]n-SH (II), B-(A-[R3]y-SH)z (III), wherein (1) each R1 independently represents a C2-10 n-alkanediyl group, a C2-6 branched alkanediyl group, a C6-8 cycloalkanediyl group C6-10 alkanecycloalkanediyl group, -[(-CH2-)p-X-]q-(-CH2-)r- or -[(-CH2-)p-X-]q-(-CH2-)r- where at least one -CH2- is replaced by a methyl group, wherein: (i) each X is independently selected from O, S and -NR6-, where R6 is a hydrogen atom or methyl; (ii) p is an integer having a value in range from 2 to 6, (iii) q is an integer having a value in the range of 0 to 5; and (iv) r is an integer having a value in the range of from 2 to 10; (2) each R2 is independently a C2-10 n-alkanediyl group, a C2-6 branched alkanediyl group, a C6-8 cycloalkanediyl group, a C6-10 alkanecycloalkanediyl group or -[(-CH2-)p-X-]q-(-CH2-)r-, wherein: (i) each X is independently selected from O, S and -NR6-, where R6 is a hydrogen atom or methyl; (ii) p is an integer having a value in the range of from 2 to 6; (iii) q is an integer having a value in the range of 0 to 5; and (iv) r is an integer having a value in the range of from 2 to 10; (3) m is a rational number in the range from 0 to 10; and (4) n is an integer having a value in the range of 1 to 60; (5) A is a structure represented by the formula: -R1-[-S-(CH2)2-O-[-R2-O-]m-(CH2)2-S-R1-]n-, in which (I) each R1 independently represents a C2-10 n-alkanediyl group, a C2-6 branched alkanediyl group, a C6-8 cycloalkanediyl group, a C6-10 alkanecycloalkanediyl group, -[(-CH2-)p-X-]q-(-CH2-)r- or -[(-CH2-)p-X-]q-(-CH2-)r-, wherein at least one -CH2- is replaced by a methyl group, wherein: (i) each X is independently selected from O, S and - NR6-, wherein R6 represents a hydrogen atom or a methyl group; (ii) p is an integer having a value in the range of from 2 to 6; (iii) q is an integer having a value in the range of 0 to 5; and (iv) r is an integer having a value in the range of from 2 to 10; (II), each R2 independently represents a C2-10 n-alkanediyl group, a C2-6 branched alkanediyl group, a C6-8 cycloalkanediyl group, a C6-10 alkanecycloalkanediyl group or -[(-CH2-)p-X-]q-(-CH2-)r-, wherein: (i) each X is independently selected from O, S and -NR6-, where R6 is a hydrogen atom or methyl; (ii) p is an integer having a value in the range of from 2 to 6; (iii) q is an integer having a value in the range of 0 to 5; and (iv) r is an integer having a value in the range of from 2 to 10; (III) m is a rational number in the range of 0 to 10; and (IV) n is an integer having a value in the range of from 1 to 60; (6) y is 0 or 1; (7) R3 is a single bond when y is 0, and -S-(CH2)2-[-O-R2-]m-O- when y is 1; (8) z is an integer ranging from 3 to 6; and (9) B is the z-valent residue of the polyfunctionalizing agent; and (ii) a compound containing terminal alkenyl groups comprising a polyvinyl ether and/or a polyallyl compound; the composition of the first sealant at least partially transmits ultraviolet radiation, and the composition of the second sealant is UV curable. A method for sealing a fastening device is also described, comprising: applying the abovementioned sealing cap to a fastening device; and ultraviolet exposure to the sealing cap to completely cure the second sealant in order to seal the fixing device. The fixing device including the above sealing cap is described.
EFFECT: producing a preformed sealing cap characterized by a shorter curing time and being visually transparent.
15 cl, 8 dwg, 8 tbl, 20 ex
