Optical laminate, polarizer, and display apparatus
An optical laminate includes a translucent substrate, and at least one optical functional layer provided on of the translucent substrate. The optical functional layer has a concave-convex shape on at least one surface. The optical functional layer contains two types of inorganic fine particles, and resin particles. The optical laminate has an internal haze X and a total haze Y satisfying (1) Y>X, (2) Y≤X+17, (3) Y≤57, and (4) 19≤X≤40. The optical laminate has a transmitted image clarity of 30% to 70% as measured using a 0.5-mm width optical comb. The number of projections having a height of not smaller than 0.1 μm is not less than 600 per mm 2 of measurement area in the concave-convex shape as measured by optical interferometry at an outermost surface of the optical functional layer.
1. An optical laminate comprising a translucent substrate, and at least one optical functional layer provided on the translucent substrate, wherein
the at least one optical functional layer comprises a concave-convex shape on at least one surface, and the concave-convex shape comprises projections,
the at least one optical functional layer comprises inorganic fine particles comprising first and second types of inorganic fine particles, and also comprises resin particles,
an internal haze X and a total haze Y of the optical laminate satisfies the following conditions (1) to (4),
Y>X (1),
Y≤X+ 17 (2),
Y≤ 57 (3),
19≤ X≤ 40 (4),
the optical laminate comprises a transmitted image clarity of 30% to 70% as measured using a 0.5-mm width optical comb,
the number of projections comprising a height of not smaller than 0.1 μm is not less than 600 per mm 2 of measurement area in the concave-convex shape as measured by optical interferometry at an outermost surface of the at least one optical functional layer,
the number of projections comprising a height of not smaller than 0.1 μm and an area of smaller than 100 μm 2 in the concave-convex shape is not smaller than 65% of the number of all projections comprising a height of not smaller than 0.1 μm in the concave-convex shape as measured by optical interferometry at the outermost surface of the at least one optical functional layer, and
an average area of all projections comprising a height of not smaller than 0.1 μm is not greater than 500 μm 2 in the concave-convex shape as measured by optical interferometry at the outermost surface of the at least one optical functional layer.
2. The optical laminate according to claim 1 , wherein
the first and second types of inorganic fine particles of the at least one optical functional layer comprise inorganic nanoparticles and swellable clay.
3. The optical laminate according to claim 2 , wherein
a content proportion A (% by mass) of the resin particles in the at least one optical functional layer and a content proportion B (% by mass) of the inorganic nanoparticles in the at least one optical functional layer satisfies the following conditions (5) and (6):
0< B≤ 0.5 A− 0.0225 (5)
7.0≤ A≤ 15.0 (6)
4. The optical laminate according to claim 1 , wherein
the at least one optical functional layer comprises at least one layer comprising a radiation curable resin composition as a main component.
5. The optical laminate according to claim 1 , wherein
the first and second types of inorganic fine particles of the at least one optical functional layer form an aggregate.
6. The optical laminate according to claim 1 , further comprising:
a refractive index adjustment layer, an anti-static layer, an antifouling layer, or a combination thereof.
7. A polarizer comprising the optical laminate according to claim 1 , and
a polarizing substrate provided on the translucent substrate of the optical laminate.
8. A display apparatus comprising the optical laminate according to claim 1 .