Functional film and method for producing same

A functional film comprising:

• a substrate containing an acetyl cellulose resin;
• a primer layer containing a filler and disposed on the substrate;
• and
• a functional layer containing a filler and disposed on the primer layer,
• wherein the substrate has a permeation layer adjacent to the primer layer and formed by permeation of a resin contained in the primer layer into part of the substrate, and the permeation layer has a thickness of 0.1 μm or more and 3.5 μm or less;
• the primer layer has a thickness of 0.1 μm or more and 1.0 μm or less;
• the filler in the primer layer and the filler in the functional layer are silica particles having an average particle size of 20 nm or more and 80 nm or less;
• in a cross section of the functional layer in a thickness direction, 90 particles or more and 150 particles or less of the filler in the functional layer are present per 0.5 μm2;
• in a cross section of the primer layer in the thickness direction, 15 particles or more and 45 particles or less of the filler in the primer layer are present per 0.2 μm2;
• and
• the primer layer and the functional layer each contain a resin, and the primer layer has the same resin component as the functional layer.

A functional film comprising:

• a substrate containing an acetyl cellulose resin;
• a primer layer containing a filler and disposed on the substrate;
• and
• a functional layer containing a filler and disposed on the primer layer,
• wherein the substrate has a permeation layer adjacent to the primer layer and formed by permeation of a resin contained in the primer layer into part of the substrate, and the permeation layer has a thickness of 0.1 μm or more and 3.5 μm or less;
• the primer layer has a thickness of 0.1 μm or more and 1.0 μm or less;
• the filler in the primer layer and the filler in the functional layer are silica particles having an average particle size of 20 nm or more and 80 nm or less;
• in a cross section of the primer layer in a thickness direction, 15 particles or more and 45 particles or less of the filler in the primer layer are present per 0.2 μm2;
• and
• the primer layer and the functional layer each contain a resin, and the primer layer has the same resin component as the functional layer.

A functional film comprising:

• a substrate containing an acetyl cellulose resin;
• a primer layer containing a filler and disposed on the substrate;
• and
• a functional layer containing a filler and disposed on the primer layer,
• wherein the substrate has a permeation layer adjacent to the primer layer and formed by permeation of a resin contained in the primer layer into part of the substrate, and the permeation layer has a thickness of 0.1 μm or more and 3.5 μm or less;
• the primer layer has a thickness of 0.1 μm or more and 1.0 μm or less;
• the filler in the primer layer and the filler in the functional layer are silica particles having an average particle size of 20 nm or more and 80 nm or less;
• the filler in the primer layer has a density of 15% or more and 30% or less in a cross section of the primer layer in a thickness direction;
• and
• the primer layer and the functional layer each contain a resin, and the primer layer has the same resin component as the functional layer.