Moisture-curable silylated polyurea and adhesive, sealant and coating compositions containing same

A pressure sensitive moisture-curable adhesive composition comprising a silylated polyurea or mixture thereof which comprises the reaction product of at least one organofunctional silane (a) possessing hydrolyzable functionality and at least one amine-terminated polyurea prepolymer (b), organofunctional silane (a) being an amine-reactive silane (a)(1) and, polyurea (b) being obtained from the reaction of at least one polyamine (c) and at least one polyisocyanate (d) in the substantial absence of organofunctional silane (a), the polyurea prepolymer possessing an average of from 80 to 100 equivalent percent of urea groups based on the total equivalents of urea and urethane groups therein, and wherein the silylated polyurea possesses a number average molecular weight of from 3,000 to 100,000 and a viscosity of from 5,000 to 5,000,000 cps and wherein the adhesive possesses a probe tack for 100 g/cm2 applied force of from 393 g/cm2 to 635 g/cm2, wherein polyurea prepolymer (b) is reacted with organofunctional silanes of the general formula:

• Q-R1—SiXaY3-a
• wherein Q is an amine-reactive functionality, R1 is a divalent bridging group having from 2 to 12 carbon atoms, each X is independently hydrogen or hydrocarbyl of up to 12 carbon atoms, each Y is the same or different hydrolyzable group and a is 0, 1 or 2;
• wherein amine-reactive silane (a)(1) is at least one isocyanatosilane (a)(1)(i) selected from the group consisting of methyldimethoxysilylethyl isocyanate, trimethoxysilylethyl isocyanate, ethyldimethoxysilylethyl isocyanate, methyldiethoxysilylethyl isocyanate, trimethoxysilylethyl isocyanate, ethyldiethoxysilylethyl isocyanate, methyldimethoxysilylpropyl isocyanate, trimethoxysilylpropyl isocyanate, ethyldimethoxysilylpropyl isocyanate, methyldiethoxysilylpropyl isocyanate, triethoxysilylpropyl isocyanate, ethyldiethoxysilylpropyl isocyanate, methyldimethoxysilylpropyl isocyanate, methyldimethoxysilylbutyl isocyanate, trimethoxysilylbutyl isocyanate, ethyldimethoxysilylbutyl isocyanate, methyldiethoxysilylbutyl isocyanate, trimethoxysilylbutyl isocyanate, ethyldiethoxysilylbutyl isocyanate, methyldimethoxysilylpentyl isocyanate, trimethoxysilylpentyl isocyanate, ethyldimethoxysilylpentyl isocyanate, methyldiethoxysilylpentyl isocyanate, triethoxysilylpentyl isocyanate, ethyldiethoxysilylpentyl isocyanate, methyldimethoxysilylpentyl isocyanate, methyldimethoxysilylhexyl isocyanate, trimethoxysilylhexyl isocyanate, ethyldimethoxysilylhexyl isocyanate, methyldiethoxysilylhexyl isocyanate, triethoxysilylhexyl isocyanate, ethyldiethoxysilylhexyl isocyanate, methyldimethoxysilylhexyl isocyanate and λ-trimethoxysiloxydimethylsilylpropyl isocyanate, and/or
• at least one epoxysilane (a)(1)(ii) selected from the group of 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)-ethyltriethoxysilane and/or,
• at least one (meth)acryloxysilanes (a)(1)(iii) selected from the group of 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-acryloxypropyltriisopropoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxyisobutyltrimethoxysilane, 3-acryloxypropyltrichlorosilane, 3-methacryloxyisobutyltrichlorosilane, 3-methacryloxyisobutyltrichorosilane and 3-methacryloxypropyl[tris(beta-methoxyethoxy)] silane;
• and,
• wherein polyurea (b) is amine-terminated polyurea (b)(1) or mixture thereof in which at least a portion up to substantially all of the amine groups present therein are secondary amine groups.