Insulating glass unit with a system of structural primary sealant.

An insulating glass unit (40) including: a first sheet (44) of glass; a second sheet (50) of glass; and a spacer system (56) including (i) a spacer (58) positioned between an inner surface (46) of the first sheet (44) of glass and an inner surface (52) of the second sheet (50) of glass, and (ii) a sealant system (60) for adhering the inner surfaces (46, 52) of the sheets (44, 50) to the spacer (58), the sealant system (60) having a dual-seal system having two regions sealants separate or distinct (80, 82), including: at least a primary sealant (82), including: (a) at least one thermoplastic hot melt having a melting temperature of about 125 ° F (51 ° C) to 250 ° F (121 ° C); and (b) at least one curable material, wherein the primary sealant, when cured, forms a covalent bond between the spacer (58) and leaves (44, 50), and wherein the primary sealant has an initial hardness in the range of 25 Shore a to 45 Shore a and a post-cure of about 30 Shore a to 65 Shore a and, upon curing, a transmission rate lower moisture vapor 2, 5 g / m2 / day and a hardness value module curing the order of 35 psi (2, 5 kg / cm2) to 100 psi (7 kg / cm2), and a secondary sealant (80) having a cured higher than the primary sealant (82) module.