Thiol-ene cured oil-resistant polyacrylate sealants for in-place gasketing applications

摘要

The present invention relates to thiol-ene curing compositions, which cure upon exposure to ultraviolet (UV) light and/or heat. The compositions include components having alkenyl (or “ene”) functionality and components having thiol functionality, which undergo thiol-ene curing. The compositions also include a cure system. More specifically, in some embodiments, the curable compositions include a vinyl polymer bearing alkenyl or thiol terminal functional group(s) and a cross-linking agent having the opposing functionality, i.e., thiol cross-linking agents with alkenyl-terminated vinyl polymers and vinyl cross-linking agents with thiol-terminated vinyl polymers. Also provided are methods of making and using the compositions, such as for sealants for in-place gasketing applications.

主权项

1. A composition comprising:
(a) a vinyl polymer bearing at least one terminal functional group having the formula I or II:wherein:
R1 and R2 are independently selected from the group consisting of H, C1-6 alkyl and C4-8 cycloalkyl, or R1 and R2 when taken together with the carbon atoms to which they are attached complete a C4-8 cycloalkenyl ring optionally containing a heteroatom; X is selected from the group consisting of C1-12 hydrocarbyl, oxygen and sulfur, wherein said C1-12 hydrocarbyl optionally comprises one or more groups selected from ether, thioether, acetal, thioacetal, ester, thioester, urethane, urea, thiourea, amine, amide, thioamide, carbamate and carbonate; Y is selected from the group consisting of C1-17 hydrocarbyl optionally comprising one or more groups selected from ether, thioether, acetal, thioacetal, ester, thioester, urethane, urea, thiourea, amine, amide, thioamide, carbamate and carbonate; x is 1 to 3; (b) a cross-linking agent comprising one or more of: (i) a thiol cross-linking agent when said vinyl polymer of (a) bears at least one functional group having the formula I; or (ii) a vinyl cross-linking agent when said vinyl polymer of (a) bears at least one functional group having the formula II; and (c) a cure system, wherein said vinyl polymer has the formula III:wherein n is 2 and A is a vinyl polymer backbone selected from the formulas V and VI:wherein:
R3 is selected from C1-6 alkyl, —CH2OCH3 and —CH2CH2OCH3; R4 is ethyl; R5 is independently selected from —OC(O)—CH2—CH3; —OC(O)—CH2—CH2—OCH3; and —OC(O)—(CH2)3—CH3; m is 10 to 10,000; and p is 5 to 5,000.