Composite sheet, substrate for a display element including same, and display device including same
The present invention relates to a composite sheet, to a substrate for a display element including same, and to a display device including same. More specifically, the composite sheet comprises: a reinforcement-impregnated matrix; a coating layer formed on at least one surface of the matrix; and a barrier layer formed on at least one surface of the coating layer, wherein, if an elastic modulus of the matrix is E2 at a temperature of 25° C. and an elastic modulus of the coating layer is E3 at a temperature of 25° C., the ratio of the elastic modulus, i.e. E3/E2, is approximately 5×10 4 or less.
1. A composite sheet comprising:
a matrix comprising at least one of a silicone resin, a styrene-butadiene rubber (SBR), a butadiene rubber, an isoprene rubber, a chloroprene rubber, a neoprene rubber, an ethylene-propylene-diene terpolymer, a styrene-ethylene-butylene-styrene (SEBS) block copolymer, a styrene-ethylene-propylene-styrene (SEPS) block copolymer, an acrylonitrile-butadiene rubber (NBR), a hydrogenated nitrile rubber (NBR), a fluorinated rubber, or a plasticized polyvinyl chloride;
a reinforcement material impregnated into the matrix;
a coating layer formed on at least one surface of the matrix; and
a barrier layer formed on at least one surface of the coating layer, wherein the coating layer is formed between the matrix and the barrier layer,
wherein, when the matrix has an elastic modulus at 25° C. of E2 and the coating layer has an elastic modulus at 25° C. of E3, a ratio of the elastic modulus E3/E2 is about 5×10 4 or less,
wherein the coating layer comprises at least one of acrylic resins, epoxy resins, urethane resins, and unsaturated polyester resins.
2. The composite sheet according to claim 1 , wherein the ratio of the elastic modulus E3/E2 ranges from about 10 to about 5×104.
3. The composite sheet according to claim 1 , wherein the coating layer comprises at least two layers having different elastic moduli at 25° C.
4. The composite sheet according to claim 1 , wherein the coating layer has a gradient elastic modulus structure.
5. The composite sheet according to claim 4 , wherein the coating layer is prepared through plasma treatment of a coating layer material which is an organic/inorganic hybrid solution prepared by sol/gel hydrolysis.
6. The composite sheet according to claim 1 , wherein the matrix has an elastic modulus at 25° C. of about 0.1 GPa or less.
7. The composite sheet according to claim 1 , wherein the coating layer has an elastic modulus at 25° C. from about 0.1 GPa to about 10 GPa.
8. The composite sheet according to claim 1 , wherein the barrier layer has an elastic modulus at 25° C. of about 10 GPa or more.
9. The composite sheet according to claim 1 , wherein when the matrix has a thickness of T2 and the coating layer has a thickness of T3, a ratio of the thicknesses T3/T2 ranges from about 1×10 −3 to about 5×10 −1 .
10. The composite sheet according to claim 1 , wherein the reinforcement material comprises at least one of glass fibers, glass fiber cloths, glass fabrics, nonwoven glass fabrics, glass meshes, glass beads, glass flakes, silica particles, and colloidal silica.
11. The composite sheet according to claim 1 , wherein the barrier layer comprises at least one of silicon nitride, silicon oxide, silicon carbide, aluminum nitride, aluminum oxide, ITO, and IZO.
12. A substrate for display elements comprising the composite sheet according to claim 1 .
13. A display comprising the substrate for display elements according to claim 12 .