EP-4735927-A1 - LIGHT CONTROL FILM

EP4735927A1EP 4735927 A1EP4735927 A1EP 4735927A1EP-4735927-A1

Abstract

A light control film includes an optical film shaped to define a plurality of substantially linear alternating ridges and grooves extending along substantially a same first direction and arranged along an orthogonal second direction. Each of the grooves includes first and second layers disposed therein and stacked along a thickness direction of the light control film. The second layer is disposed between the first layer and a bottom of the groove. For each pair of adjacent ridge and groove in the plurality of alternating ridges and grooves, an interface layer that is substantially coextensive along the first direction with the ridge is disposed between the ridge and the first layer disposed in the groove such that at least a portion of the second layer is not separated from the ridge by the interface layer.

Inventors

VAN LENGERICH, Henrik B.
KENNEY, RAYMOND J.
TARNOWSKI, David J.
CHEN-HO, KUI
COONCE, Benjamin R.
TIU, Brylee David B.
THUNHORST, KRISTIN L.
STAY, MATTHEW S.
SMITH, Matthew R.D.
HEINZEN, John-Paul R.
SCHMIDT, DANIEL J.
GOTRIK, Kevin W.
NELSON, Caleb T.
KAWAKAMI, Ellison G.
PICHA, Kayla C.

Assignees

3M Innovative Properties Company

Dates

Publication Date: 20260506
Application Date: 20240621

Claims (15)

1. A light control film comprising an optical film shaped to define a plurality of substantially linear alternating ridges and grooves extending along substantially a same first direction and arranged along an orthogonal second direction, each of the grooves comprising first and second layers disposed therein and stacked along a thickness direction of the light control film, each of the first and second layers having a maximum thickness of greater than about 0.01 microns, the second layer disposed between the first layer and a bottom of the groove, wherein, for each pair of adjacent ridge and groove in the plurality of alternating ridges and grooves, an interface layer that is substantially coextensive along the first direction with the ridge is disposed between the ridge and the first layer disposed in the groove such that at least a portion of the second layer is not separated from the ridge by the interface layer, the interface layer having a maximum thickness of greater than about 0.01 microns and less than about 10 microns.
2. The light control film of claim 1, wherein, for each pair of adjacent ridge and groove in the plurality of alternating ridges and grooves, no portion of the interface layer is disposed between the ridge and the second layer.
3. The light control film of claim 1, wherein in a planar cross-section of the optical film that is substantially orthogonal to the light control film and the first direction, each of the ridges has maximum width that is within 20% of a minimum width of the ridge.
4. The light control film of claim 1, wherein the second layers are less than about 10 microns thick and the first layers are greater than about 10 microns thick.
5. The light control film of claim 1, wherein the first layers have substantially a same first composition and the second layers have substantially a same second composition different from the first composition.
6. The light control film of claim 5, wherein the first composition comprises an acrylate and the second composition comprises one or more of a polyvinyl alcohol, a silicone, a wax, a paraffin, a hydrophobic material, a fluorinated material, ethylene vinyl acetate, polyvinyl butyral, polylactic acid, and a thermoplastic resin.
7. The light control film of claim 1, wherein for each pair of adjacent ridge and groove in the plurality of alternating ridges and grooves, each of the bottom of the grove and a top of the ridge is substantially free of any light absorbing layer.
8. The light control film of claim 1, wherein the interface layer is substantially light absorbing having an optical density of greater than about 0.1.
9. A light control film comprising a structured major surface extending continuously across substantially an entire length and an entire width of the light control film and comprising a plurality of structures, each of the structures comprising a top surface extending between and joining opposing side surfaces, such that for each pair of adjacent first and second structures in the plurality of structures: a first side surface of the first structure faces a second side surface of the second structure, the first and second side surfaces are connected to each other by a connecting surface portion of the structured major surface; a first layer having a same first composition coats at least a majority of each of the first and second side surfaces; and a same second layer having a same second composition different than the first composition, coats at least a majority of the connecting surface portion and coats adjacent portions of the first and second side surfaces.
10. The light control film of claim 9, wherein for each pair of adjacent first and second structures in the plurality of structures, no portion of the first layers is disposed between the second layer and the structured major surface.
11. The light control film of claim 9, wherein for each pair of adjacent first and second structures in the plurality of structures, the second layer coats portions of each of the first and second side surfaces.
12. A light control film comprising a structured major surface extending continuously across substantially an entire length and an entire width of the light control film and comprising a plurality of structures, each of the structures comprising a top surface extending between and joining opposing side surfaces of the structure, such that for each structure in the plurality of structures: a first layer having a same first composition is disposed on, and coextensive with, at least a majority of each of the first and second side surfaces; and a second layer having a same second composition different than the first composition coats at least a majority of the top surface and coats portions of each of the first and second side surfaces adjacent to the top surface.
13. The light control film of claim 12, wherein for each structure in the plurality of structures, the second layer is a release layer, and for each of the first and second side surfaces, the first layer is optically absorptive and substantially permanently attached to the side surface.
14. The light control film of claim 13, wherein for at least one side surface of each of at least some of the structures in the plurality of structures, the first layer at least partially covers the release layer.
15. The light control film of claim 12, further comprising a third layer disposed over the structured maj or surface and substantially filling spaces between adjacent structures of the plurality of structures, wherein for each of the structures, no portion of the third layer is disposed between the structure and either of the first or second layers.

Description

LIGHT CONTROL FILM TECHNICAL FIELD The present description generally relates to light control films. BACKGROUND A light control film generally controls the angular distribution of light transmitted through the light control film. SUMMARY In some aspects, the present description provides a light control film including an optical film shaped to define a plurality of substantially linear alternating ridges and grooves extending along substantially a same first direction and arranged along an orthogonal second direction. Each of the grooves includes first and second layers disposed therein and stacked along a thickness direction of the light control film. Each of the first and second layers has a maximum thickness of greater than about 0.01 microns. The second layer is disposed between the first layer and a bottom of the groove. For each pair of adjacent ridge and groove in the plurality of alternating ridges and grooves, an interface layer that is substantially coextensive along the first direction with the ridge is disposed between the ridge and the first layer disposed in the groove such that at least a portion of the second layer is not separated from the ridge by the interface layer. The interface layer has a maximum thickness of greater than about 0.01 microns and less than about 10 microns. In some aspects, the present description provides a light control film having a structured major surface extending continuously across substantially an entire length and an entire width of the light control film and including a plurality of structures. Each of the structures has a top surface extending between and joining opposing side surfaces. The light control film is such that for each pair of adjacent first and second structures in the plurality of structures: a first side surface of the first structure faces a second side surface of the second structure, where the first and second side surfaces are connected to each other by a connecting surface portion of the structured major surface; a first layer having a same first composition coats at least a majority of each of the first and second side surfaces; and a same second layer having a same second composition different than the first composition, coats at least a majority of the connecting surface portion and coats adjacent portions of the first and second side surfaces. In some aspects, the present description provides a light control film having a structured major surface extending continuously across substantially an entire length and an entire width of the light control film and comprising a plurality of structures. Each of the structures having a top surface extending between and joining opposing side surfaces of the structure. The light control film is such that for each structure in the plurality of structures: a first layer having a same first composition is disposed on, and coextensive with, at least a majority of each of the first and second side surfaces; and a second layer having a same second composition different than the first composition coats at least a majority of the top surface and coats portions of each of the first and second side surfaces adjacent to the top surface. In some aspects, the present description provides a method of making a light control film. The method includes: depositing an optically absorptive layer onto a first structured major surface of a first film such that the optically absorptive layer substantially conforms to the first structured major surface, where the first structured major surface comprises a plurality of first structures arranged along a first direction and defining a plurality of first channels extending along an orthogonal second direction, and where each first channel is disposed between adjacent first structures and has an open top opposite a bottom of the first channel; removing the optically absorptive layer from a top portion of each first structure of the plurality of first structures, where the top portions of the first structures are adjacent to the open tops of the first channels; for each first channel in the plurality of first channels, disposing a release layer on the optically absorptive layer along the bottom of the first channel and along at least a portion of sidewalls of the first structures adjacent the first channel; after the removing and disposing steps, substantially filling each first channel in the plurality of first channels with a resin; solidifying the resin to form a second film including a land portion and a second structured major surface including a plurality of second structures, where each second structure extends from the land portion to a top portion of the second structure, and where the top portion extends between and joins opposing sidewalls of the second structure; separating the first and second films such that the second film includes the optically absorptive layer disposed on the sidewalls and top portions of the second structures; and for each second structure in