JP-2022531662-A5 -

Dates

Publication Date

20230510

Application Date

20200428

Description

Unless otherwise indicated, the descriptions of elements in the figures should be understood to apply equally to corresponding elements in other figures. While specific embodiments have been illustrated and described herein, it will be understood by those skilled in the art that various alternative and/or equivalent practices can replace the illustrated and described embodiments without departing from the scope of this disclosure. This application is intended to encompass all adaptable or modified examples of the specific embodiments described herein. Therefore, this disclosure is limited only by the claims and their equivalents. Exemplary embodiments are described below. [Item 1] It is an optical stack, An optical film comprising a plurality of alternating first polymer layers and second polymer layers totaling at least 50, wherein each of the first polymer layer and the second polymer layer has an average thickness of less than approximately 500 nm, An optical adhesive disposed on the optical film, comprising: a first main surface facing the optical film and bonded to the optical film; and a second structured main surface on the opposite side, having a plurality of irregularly arranged intersecting channels formed thereon, wherein the channels define a plurality of substantially flat land regions therein, the land regions comprising at least about 50% of the total surface area of the second structured main surface, and as a result, when the optical stack is placed on a support surface with the second structured main surface of the optical adhesive in contact with the support surface, the optical stack is bonded to the support surface and can be removed from the support surface or slidably repositioned on the support surface without damaging the optical adhesive or the support surface, and when at least one of heat and pressure is applied, the optical stack is substantially permanently bonded to the support surface and the plurality of channels substantially disappear. [Item 2] The optical stack according to item 1, wherein the optical adhesive has sound-absorbing properties for reducing noise inside a motorized vehicle, and as a result, the ratio of the loss modulus G'' of the optical adhesive to the storage modulus G' exceeds approximately 0.3 for frequencies in the range of approximately 1000 Hz to approximately 3200 Hz. [Item 3] The optical stack according to item 1 or 2, wherein each of the plurality of irregularly arranged cross channels is substantially linear. [Item 4] The optical stack according to any one of items 1 to 3, wherein the optical film is a reflective polarizer or a mirror. [Item 5] The optical stack according to any one of items 1 to 4, wherein the optical adhesive comprises polyvinyl butyral, acrylate, thermoplastic polyurethane, ethylene-vinyl acetate, or one or more of these. [Item 6] The optical stack according to any one of items 1 to 5, wherein the optical stack is positioned on a support surface with the second structured main surface of the optical adhesive in contact with the support surface, and when the optical adhesive is heated to a temperature of about 40°C to 160°C and subjected to a pressure of about 4 atm to 12 atm, the optical stack is substantially permanently bonded to the support surface and the plurality of channels substantially disappear. [Item 7] It is an optical stack, Optical film and An optical adhesive comprising an optical adhesive that is adhered to the optical film and faces away from the optical film, wherein a plurality of channels are formed on the first main surface, each channel including a side wall that defines a raised portion extending upward beyond the portion of the first main surface near the channel and having substantially the same extent as the channel along at least a portion of the length of the channel, and as a result when the optical stack is placed on a support surface with the first main surface of the optical adhesive in contact with the support surface, the optical stack is bonded to the support surface and can be removed from the support surface or slidably repositioned on the support surface without damaging the optical adhesive or the support surface, and when at least one of heat and pressure is applied, the optical stack is substantially permanently bonded to the support surface and the plurality of channels and raised portions substantially disappear. [Item 8] The optical stack according to item 7, wherein the optical film comprises a plurality of alternating first polymer layers and second polymer layers that reflect or transmit light mainly by optical interference. [Item 9] The optical stack according to any one of items 1 to 6 and 8, wherein the first polymer layer has a first in-plane birefringence which is the difference between the refractive index along a first in-plane direction of the first layer and the refractive index along a second in-plane direction orthogonal to the first layer, and the second polymer layer h