Light curable resin composition
The present application relates to a resin composition and in particular to a light-curable resin composition. It is known to achieve a thixotropic behavior of an adhesive composition by adding an inorganic additive like fumed silica. Adding inorganic additives results in significant particle problems as fumed silica is a solid particle and affects the optical performance of the adhesive composition. In accordance with the invention a particle free resin composition with a thixotropic behavior is provided. The inventive composition comprises a) 30 to 90 wt % of a urethane acrylate oligomer with a molecular weight greater than 15000, b) 2 to 40 wt % of a (meth)acrylate monomer having a benzene ring, and c) 0.2 to 10 wt % of a photo initiator.
1. An optical device comprising:
a) a touch screen; and
b) a base substrate selected from a display panel, a liquid crystal display, a plasma display, a light emitting display, an electrophenetic display and a cathode ray display, wherein the touch screen and the base substrate are adhered to one another by a cured reaction product of a composition comprising a light-curable composition, comprising
a) 30 to 90 wt % of a urethane acrylate oligomer with a molecular weight greater than 15000,
b) 2 to 40 wt % of a (meth)acrylate monomer having a benzene ring, and
c) 0.2 to 10 wt % of a photo initiator.
2. The device according to claim 1 , wherein the urethane acrylate oligomer is an aliphatic urethane acrylate.
3. The device according to claim 1 , wherein the (meth)acrylate monomer having a benzene ring is a member selected from the group consisting of benzyl acrylate, phenoxyethyl acrylate, nonylphenoxypolyethylene glycol acrylate, ethoxylated bisphenol A diacrylate, phenoxyethyl methacrylate, ethoxylated bisphenol A dimethacrylate, benzyl methacrylate, 1-phenylethyl methacrylate, 2-phenoxyethyl methacrylate, 2-phenylethyl methacrylate, 3-phenylpropyl methacrylate, 3-phenylpropyl acrylate and 2-phenoxyethyl acrylate and combinations thereof.
4. The device according to claim 3 , wherein the (meth)acrylate monomer having a benzene ring is a member selected from the group consisting of
5. The device according to claim 1 , wherein the photoinitiator is a member selected from the group consisting of phenylglyoxylates, α-hydroxyketones, α-aminoketones, benzildimethylketal, monoacylphosphinoxides, bisacylphosphinoxides, benzophenones, oxime esters, titanocene and combinations thereof.
6. The according to claim 1 , wherein the composition comprises:
a) 40 to 80 wt % of a urethane acrylate oligomer with a molecular weight of more than 15000,
b) 5 to 30 wt % of a (meth)acrylate monomer having a benzene ring, and
c) 0.5 to 6 wt % of a photo initiator.
7. The device according to claim 1 , wherein the composition further comprises up to 40 wt % deformer, ultra-violet light absorber, light stabilizer, silane coupling agent, antioxidant and combinations thereof.
8. The device according to claim 7 , wherein the deformer is based on silicones.
9. The device according to claim 7 , wherein the antioxidant is a member selected from the group consisting of phenolic, aminic, sulphur-based antioxidants and multifunctional antioxidants or combinations thereof.
10. The according to claim 7 , wherein the ultra-violet light absorber is a benzotriazole type ultra-violet light absorber.
11. The device according to claim 1 , wherein the composition comprises
a) 40 to 80 wt % of a urethane acrylate oligomer with a molecular weight of more than 20,000,
b) 5 to 30 wt % of a (meth)acrylate monomer having a benzene ring, and
c) 0.5 to 6 wt % of a photo initiator,
wherein the composition has a thixotropic ratio of 1.7.