Stacked structure for display cover window having improved scratch resistance using difference in elastic modulus and method of manufacturing the same
The present disclosure relates to a stacked structure for a display cover window having improved scratch resistance using a difference in elastic modulus, and a method of manufacturing the same. The stacked structure for a display cover window includes a base member having an elastic modulus of 2.5 GPa to 5.5 GPa; a hard coating member disposed on the base member and having an elastic modulus of 0.546 times to 2.4 times the elastic modulus of the base member; and a damping member disposed beneath the base member and having an elastic modulus of 0.0000018 to 0.02 times the elastic modulus of the base member. The stacked structure for a display cover window has an effect of remarkably improving scratch resistance by reducing a normal force, which is a major component of frictional force that is a main cause of scratching.
1 . A stacked structure for a display cover window having improved scratch resistance using a difference in elastic modulus, comprising:
a base member having an elastic modulus of 2.5 GPa to 5.5 GPa;
a hard coating member disposed on the base member and having an elastic modulus of 0.546 times to 2.4 times the elastic modulus of the base member; and
a damping member disposed beneath the base member and having an elastic modulus of 0.0000018 times to 0.02 times the elastic modulus of the base member,
wherein
the hard coating member has an elastic modulus of 3.0 GPa to 6.0 GPa, and
the damping member has an elastic modulus of 0.01 GPa to 0.05 GPa,
wherein the damping member has a thickness of 0.05 times to 0.36 times the thickness of the base member, and the damping member has a thickness of 10 μm to 20 μm,
wherein the hard coating member includes 3 to 5 parts by weight of hexamethylene diisocyanate trimer (HDI-trimer), 20 to 24 parts by weight of pentaerythritol triacrylate (PETA), 10 to 15 parts by weight of nano-silica, 5 to 8 parts by weight of methyl methacrylate, 10 to 15 parts by weight of a curing agent, 0.1 to 0.5 parts by weight of a leveling agent, and 1 to 2 parts by weight of a photocuring agent, the base member includes poly (methyl methacrylate) (PMMA), and the damping member includes any one of a cured silicon-based adhesive layer or a cured acryl-based adhesive layer.
2 . The stacked structure for a display cover window of claim 1 , wherein the hard coating member has a thickness of 0.001 times to 0.198 times the thickness of the base member.
3 . The stacked structure for a display cover window of claim 2 , wherein the base member has a thickness of 101 μm to 1000 μm,
the hard coating member has a thickness of 1 μm to 20 μm.
4 . The stacked structure for a display cover window of claim 3 , wherein the base member include:
a first base member having a thickness of 45 μm to 350 μm or less,
an auxiliary damping member disposed beneath the first base member and having a thickness of 11 μm to 300 μm or less; and
a second base member disposed beneath the auxiliary damping member and having a thickness of 45 μm to 350 μm or less.
5 . A method of manufacturing a stacked structure for a display cover window having improved scratch resistance using a difference in elastic modulus, comprising: preparing a base member having an elastic modulus of 2.5 GPa to 5.5 GPa and a thickness of 101 μm to 1000 μm and made of poly (methyl methacrylate) (PMMA) materials; preparing a hard coating solution by dissolving a solid component containing 3 to 5 parts by weight of hexamethylene diisocyanate trimer (HDI-trimer), 20 to 24 parts by weight of pentaerythritol triacrylate (PETA), 10 to 15 parts by weight of nano-silica, 5 to 8 parts by weight of methyl methacrylate, 10 to 15 parts by weight of a curing agent, 0.1 to 0.5 parts by weight of a leveling agent, and 1 to 2 parts by weight of a photocuring agent in a solvent component containing 8 to 12 parts by weight of methyl cellosolve, 2 to 4 parts by weight of butyl alcohol, and 25 to 27 parts by weight of 1-methoxy-2-propanol; forming a hard coating member having an elastic modulus of 0.546 times to 2.4 times the elastic modulus of the base member and having a thickness of 0.001 times to 0.198 times the thickness of the base member by applying the hard coating solution to an upper portion of the base member, heat-drying the hard coating solution to remove the solvent, and photocuring the hard coating solution; and forming a damping member having an elastic modulus of 0.0000018 times to 0.02 times the elastic modulus of the base member and a thickness of 0.05 times to 0.36 times the thickness of the base member by applying a silicon-based adhesive layer or an acryl-based adhesive layer toa lower portion of the base member and curing the silicon-based adhesive layer or the acryl-based adhesive layer, wherein the hard coating member has an elastic modulus of 3.0 GPa to 6.0 GPa, and the damping member has an elastic modulus of 0.01 GPa to 0.05 GPa, and wherein the damping member has a thickness of 10 μm to 20 μm.
6 . The method of manufacturing a stacked structure for a display cover window of claim 5 , wherein the forming of the hard coating member is applying the hard coating solution to the upper portion of the base member, heat-drying the hard coating solution at 80° C. to 90° C. for 30 seconds to 90 seconds to remove the solvent, and photocuring the hard coating solution with an amount of light of 300 mJ to 4 mJ, and the forming of the damping member is applying the silicon-based adhesive layer or the acryl-based adhesive layer to the lower portion of the base member, primarily heat-curing the silicon-based adhesive layer or the acryl-based adhesive layer at 110° C. to 130° C. for 90 to 150 seconds, and secondarily heat-curing the silicon-based adhesive layer or the acryl-based adhesive layer at 150° C. to 170° C. for 90 to 150 seconds.