Film for transparent screen and method for manufacture thereof, and transparent screen comprising same
Provided is a film for a transparent screen which can clearly display merchandise information, advertisement, or the like on a transparent partition or the like by projection without compromising the transmission visibility. A film for a transparent screen according to the present invention includes: a resin layer; and inorganic particles at least a portion of which is contained in an aggregated state in the resin layer, wherein primary particles of the inorganic particles have a median diameter of 0.1 to 50 nm and a maximum particle size of 10 to 500 nm, and the content of the inorganic particles is 0.015 to 1.2% by mass with respect to the resin.
1. A film for a transparent screen comprising:
a resin layer; and
inorganic particles at least a portion of which is contained in an aggregated state in the resin layer, wherein
primary particles of the inorganic particles have a median diameter of 0.1 to 50 nm and primary particles of the inorganic particles have a maximum particle size of 10 to 500 nm,
the content of the inorganic particles is 0.015 to 1.2% by mass with respect to the resin, and
the film for a transparent screen has a total light transmittance of 70% of higher, the haze value thereof is from 1.3% to 35%, and the image clarity thereof is 70% or higher.
2. The film for a transparent screen according to claim 1 , wherein
the inorganic particles are metal particles.
3. The film for a transparent screen according to claim 1 , wherein
the inorganic particles are at least one selected from the group consisting of zirconium oxide particles, titanium oxide particles, cerium oxide particles, barium titanate particles, barium sulfate particles, and silver particles.
4. The film for a transparent screen according to claim 1 , wherein
the resin layer comprises a thermoplastic resin.
5. The film for a transparent screen according to claim 4 , wherein
the thermoplastic resin comprises at least one selected from the group consisting of an acrylic resin, a polyester resin, a polyolefin resin, a cellulose resin, a vinyl resin, a polycarbonate resin, and a polystyrene resin.
6. The film for a transparent screen according to claim 4 , wherein
the thermoplastic resin comprises at least one selected from the group consisting of a polymethyl methacrylate resin, a polyethylene terephthalate resin, a polyethylene naphthalate resin, a polypropylene resin, a cycloolefin polymer resin, a cellulose acetate propionate resin, a polyvinyl butyral resin, a polycarbonate resin, and a polystyrene resin.
7. The film for a transparent screen according to claim 1 , wherein
the total light transmittance of the film for a transparent screen is 75% or higher, and the haze value thereof is from 1.5% to 30%.
8. The film for a transparent screen according to claim 1 , wherein
the image clarity of the film for a transparent screen is 80% or higher.
9. The film for a transparent screen according to claim 1 , wherein
the thickness of the resin layer is from 20 to 400 μm.
10. A transparent screen comprising the film for a transparent screen according to claim 1 .
11. A layered body comprising the transparent screen according to claim 10 .
12. A member for a vehicle comprising the transparent screen according to claim 10 .
13. A member for a house comprising the transparent screen according to claim 10 .
14. An image projection device comprising the transparent screen according to claim 10 and a projection device.
15. A method for manufacturing the film for a transparent screen according to claim 1 , comprising:
a step of kneading the resin and the inorganic particles by using a twin-screw kneading extruder while applying a shear stress of 3 to 1,800 kPa on average over the whole length of a screw of the twin-screw kneading extruder to obtain a resin composition; and
a step of forming a film made of the resin composition, wherein
the twin-screw kneading extruder comprises a flight screw including at least one mixing and kneading element selected from the group consisting of a kneading element, a mixing element, and a rotary element.
16. A method for manufacturing the film for a transparent screen according to claim 1 , comprising:
a step of mixing the inorganic particles and the resin to obtain an inorganic particle-attached resin composition;
a step of kneading the inorganic particle-attached resin composition and the resin to obtain an inorganic particle-dispersed resin composition; and
a step of forming a film made of the inorganic particle-dispersed resin composition.
17. The method for manufacturing a film for a transparent screen according to claim 16 , wherein
the step of kneading and/or the process of forming a film are performed by using a single- or twin-screw kneading extruder.