Crosslinking Aid

- Mar 11, 2019 -

The crosslinking aid according to the present invention comprises a urethane poly(meth)acrylate in combination with TAIC.


The urethane poly(meth)acrylate can be synthesized, for example, from an organic isocyanate and a hydroxyl group-containing (meth)acrylate. The urethane poly(meth)acrylate having a high molecular weight is preferred. The number-average molecular weight of the urethane poly(meth)acrylate is not less than 1000, and preferably not less than 1200. The upper limit of the number-average molecular weight of the urethane poly(meth)acrylate is usually 10,000.


The organic isocyanate is a compound having two or more isocyanate groups in a molecule thereof. Examples of the organic group include a linear, branched or cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic ring group such as isocyanurate group. Specific examples of the organic isocyanate include 1,6-hexamethylene diisocyanate, isophorone diisocyanate, toluidine diisocyanate, MDI (diphenylmethane diisocyanate), hydrogenated MDI, xylylene diisocyanate, a trimer of 1,6-hexamethylene diisocyanate, a trimer of isophorone diisocyanate, and the like.


The hydroxyl group-containing (meth)acrylate is a (meth)acrylate having one or more hydroxyl groups in a molecule thereof. Examples of the hydroxyl group-containing (meth)acrylate include (meth)acrylates of polyhydric alcohols. Specific examples of the hydroxyl group-containing (meth)acrylate include trimethylolpropane di(meth)acrylate, pentaerythritol trimethacrylate, dipentaerythritol tetra(meth)acrylate, tripentaerythritol (meth)acrylate, polyalkyl diol (meth)acrylates, polyethylene glycol (meth)acrylate, polyalkylene glycol (meth)acrylates, glycerin di(meth)acrylate and polyol (meth)acrylates. These hydroxyl group-containing (meth)acrylates may be in the form of a single acrylate or a mixture of these acrylates.


The blending ratio (weight ratio) of the urethane poly(meth)acrylate and TAIC is usually 1:9 to 9:1 and preferably 1:1 to 1:4.