| 摘要 |
1) Specific polyurethane prepolymer (PP2) comprising at least two terminal (2-oxo-1,3-dioxolan-4-yl)methyl carbamate groups of low viscosity, its preparation process and its use in the manufacture of an adhesive composition.;2) Multicomponent system comprising, as first component (A), a composition comprising at least one such polyurethane prepolymer and, as second component (B), a composition comprising at least one curing agent comprising at least two primary amine (—NH2) groups (B1).;3) Process for assembling materials employing the polyurethane prepolymer (PP2) according to the invention. |
| 主权项 |
1. A process for the preparation of a polyurethane prepolymer having (2-oxo-1,3-dioxolan-4-yl)methyl carbamate end groups (PP2) comprising:
in a first stage (denoted E1), the preparation of a polyurethane prepolymer having NCO end groups (PP1) by a polyaddition reaction: (i) of at least one diisocyanate chosen from the following aliphatic or aromatic diisocyanates, and their mixtures: a1) isophorone diisocyanate (IPDI), a2) 2,4-toluene diisocyanate (2,4-TDI), a3) 2,4′-diphenylmethane diisocyanate (2,4′-MDI), (ii) with at least one polyol chosen from polyether polyols and polydiene polyols, at a reaction temperature T1 of less than 95° C., under anhydrous conditions and in amounts of diisocyanate(s) and of polyol(s) resulting in an NCO/OH molar ratio, denoted r1, ranging from 1.6 to 1.9; then in a second stage (denoted E2), the reaction, under anhydrous conditions, at a reaction temperature T2 of less than 95° C., of the product formed in the first stage E1 with at least one glycerol carbonate in an amount of glycerol carbonate resulting in an NCO/OH molar ratio, denoted r2, ranging from 0.9 to 1.0, it being possible for the 2,4-toluene diisocyanate (2,4-TDI) to be used in the form of a TDI mixture a2) comprising at least 99% by weight of 2,4-toluene diisocyanate (2,4-TDI), with respect to the total weight of said mixture a2), and it being possible for the 2,4′-diphenylmethane diisocyanate (2,4′-MDI) to be used in the form of an MDI mixture a3) comprising at least 99% by weight of 2,4′-diphenylmethane diisocyanate (2,4′-MDI), with respect to the total weight of said mixture a3). |
