| 摘要 |
PROBLEM TO BE SOLVED: To obtain diffused light which diffuses with uniform luminance over wide visual sensation and is light with excellent transparency by hybridizing plural thermoplastic resins with a structure composed of the sea and islands and specifying the sectional shape of the island structures. SOLUTION: The light diffusive sheet 1 is composed of the sea structure 2 and the island structures 3 of various elliptical shapes consisting mainly of a minor diameter of 5 to 50μm. The island structures 4, 5 having the sizes and shapes exclusive of the minor diameter exist here and there. The greater part of the island structures 3 are arranged nearly perpendicularly to incident light 6. In the case of production by using, for example, two kinds of the transparent thermoplastic resins, even the resins varying in their melt flow rate(MFR) are generally mixed at the smaller mixing rate of the resin having the smaller MFR lower than mixing rate of the resin having the larger MFR. The resulted resin mixture is melted and is molded to a sheet form. The molding method in this case is executed by a method of compression molding to pack the resin mixture into metal molds and to thermally compress the resin mixture or extrusion molding to melt extrude the resin mixture by using an extruder and passing the resin mixture through a Tee die.
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