| 摘要 |
A urethane (meth)acrylate oligomer which is derived from a diisocyanate having two isocyanate groups which differ in reactivity; a chain-extending reagent which is a polyether polyol selected from ethoxylated and propoxylated derivatives of tri- and tetra- functional polyols; and a hydroxy (meth)acrylate selected from polyethylene glycol (meth)acrylate and polypropylene glycol (meth)acrylate. Preferably the chain-extending reagent is selected from ethoxylated and propoxylated derivatives of trimethylol propane, pentaerythritol and glycerol. Preferably the hydroxy (meth)acrylate is selected from polyethylene glycol monomethacrylate and polypropylene glycol monomethacrylate. The diisocyanate may be selected from cycloaliphatic, araliphatic and aromatic diisocyantes, preferably isophorone diisocyanate and 2,4-toluene diisocyanate. The urethane (meth)acrylate oligomer of this invention is suitable for use in adhesive compositions. |
