Method for preparing multilayer optical laminates

Abstract

To provide methods for preparing multi-layer optical laminates that are free from defects such as orange peel, by not utilizing adhesive layers but laminating films between optical substrates such as glass.SOLUTION: Methods for preparing multi-layer optical laminates include: placing an optical film 30 free of an adhesive layer between a first glass substrate 10 free of an adhesive layer and a second glass substrate 20 free of an adhesive layer; placing the laminate under a vacuum; and then heating the laminate under pressure to a temperature above the softening temperature of the optical film. The glass substrates are free of an adhesive layer but may include a silane surface treatment. The resulting multi-layer laminate is optically clear and does not show scattering of reflected light by the optical film 30.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to a method for preparing multilayer optical laminates and to optical laminates. [Background technology]

[0002] A multilayer optical laminate is an optical structure comprising three or more material layers bonded together. These optical laminates may also be articles, meaning they may be used as is or combined with other layers or structures to form an article. Laminates can take on a wide variety of shapes and forms. In some cases, a multilayer optical laminate may include a combination of a relatively rigid or semi-rigid layer, such as a glass or polymer plate, and a flexible layer, such as a film. A wide variety of methods can be used to bond the layers together, and in many cases, an adhesive layer is used.

[0003] An example of multilayer optical laminates is safety glass, typically used in automobile windshields. To prevent the windshield from shattering, safety glass structures are generally multilayer articles having two layers of glass and an optically transparent film sandwiched between the two layers of glass. The film is often bonded to the glass with a heat-activated adhesive such as polyvinyl butyral (PVB). PVB is particularly preferred because it is optically transparent, non-sticky at room temperature, can be handled as a self-supporting film at room temperature, but becomes sticky when heated and strongly bonds to both the glass and the film. Typically, a safety glass laminate of glass / PVB / film / PVB / glass is prepared, placed in an autoclave, and subjected to heat and pressure to form the laminate article. A variation of this process is described in U.S. Patent Application Publication No. 2010 / 0285310 (Izurani et al.), which describes the production of laminated glass with a plastic film inserted by first creating a laminated film by thermocompression bonding and then laminating the laminated film between curved glass plates. [Overview of the Initiative]

[0004] Methods for preparing multilayer optical laminates and multilayer optical laminates are disclosed herein. In some embodiments, the method for preparing a laminate article includes providing a first glass substrate having a first main surface and a second main surface, the second main surface of which does not contain an adhesive layer; providing a second glass substrate having a first main surface and a second main surface, the first main surface of which does not contain an adhesive layer; providing a first optical film having a first main surface and a second main surface containing one or more layers of polymer material, the first and second main surfaces of which do not contain an adhesive layer; preparing a multilayer structure by arranging the first glass substrate, the first optical film, and the second glass substrate such that the second main surface of the first glass substrate is close to the first main surface of the first optical film, and the second main surface of the first optical film is close to the first main surface of the second glass substrate; arranging the multilayer structure in a vacuum chamber; and ensuring that the second main surface of the first glass substrate is in direct surface contact with the first main surface of the first optical film. The method includes: applying a vacuum to a vacuum chamber containing a multilayer structure such that the first main surface of a second glass substrate is in direct surface contact with the second main surface of a first optical film; releasing the vacuum from the vacuum chamber; removing the multilayer structure from the vacuum chamber and placing it in a device capable of supplying heat and / or pressure; raising and maintaining the temperature of the device capable of supplying heat and / or pressure to the softening temperature of the polymer material on the first and second main surfaces of the first optical film, or a temperature above that, while applying a pressure higher than atmospheric pressure to the multilayer structure; lowering the temperature of the device capable of supplying heat and / or pressure to room temperature; and releasing the pressure higher than atmospheric pressure from the multilayer structure to form a multilayer article that is optically transparent and does not exhibit scattering of reflected light from the first optical film.

[0005] In other embodiments, a method for preparing a laminate article includes providing a first glass substrate having a first main surface and a second main surface, wherein the second main surface is a treated surface that does not contain an adhesive layer; providing a second glass substrate having a first main surface and a second main surface, wherein the first main surface is a treated surface that does not contain an adhesive layer; providing a first optical film having a first main surface and a second main surface containing one or more layers of polymer material, wherein the first and second main surfaces do not contain an adhesive layer; preparing a multilayer structure by arranging the first glass substrate, the first optical film, and the second glass substrate such that the second main surface of the first glass substrate is close to the first main surface of the first optical film, and the second main surface of the first optical film is close to the first main surface of the second glass substrate; arranging the multilayer structure in a vacuum chamber; and ensuring that the second main surface of the first glass substrate is in direct contact with the first main surface of the first optical film. The method includes: applying a vacuum to a vacuum chamber containing a multilayer structure so that the first main surface of the second glass substrate is in direct surface contact with the second main surface of the first optical film; releasing the vacuum from the vacuum chamber; removing the laminate from the vacuum chamber and placing the multilayer structure in a device capable of supplying heat and / or pressure; raising and maintaining the temperature of the device capable of supplying heat and / or pressure to the softening temperature of the polymer material of the first and second main surfaces of the first optical film, or a temperature above that, while applying a pressure higher than atmospheric pressure to the multilayer structure; lowering the temperature of the device capable of supplying heat and / or pressure to room temperature; and releasing the pressure higher than atmospheric pressure from the multilayer structure to form a multilayer article that is optically transparent and does not exhibit scattering of reflected light from the first optical film.

[0006] Multilayer articles are also disclosed. In some embodiments, a multilayer article comprises a first glass substrate having a first principal surface and a second principal surface, a second glass substrate having a first principal surface and a second principal surface, and a first optical film having a first principal surface and a second principal surface comprising one or more layers of polymer material, wherein the second principal surface of the first glass substrate is interfacially bonded to the first principal surface of the first optical film, the interfacial bond does not include an adhesive layer, the second principal surface of the first optical film is interfacially bonded to the first principal surface of the second glass substrate, the interfacial bond does not include an adhesive layer, the second principal surface to the first glass substrate and the first principal surface of the second glass substrate are treated or untreated surfaces, the treated surface includes a silane coupling agent treated surface, the multilayer article is optically transparent and does not exhibit scattering of reflected light by the first optical film. [Brief explanation of the drawing]

[0007] This application can be understood more fully by considering the following detailed description of various embodiments of the present disclosure, together with the accompanying drawings. [Figure 1] This is a cross-sectional view of an embodiment of the method disclosed herein. [Figure 2] This is a cross-sectional view of another embodiment of the method of the present disclosure. [Figure 3] This is a cross-sectional view of yet another embodiment of the method of the present disclosure.

[0008] In the following description of the exemplary embodiments, reference is made to the accompanying drawings illustrating various embodiments that may be used to implement the Disclosure. It should be understood that the embodiments can be used without departing from the scope of the Disclosure, and that structural modifications may be made. These drawings are not necessarily to a constant scale. Similar numbers used in the drawings indicate similar components. However, it should be understood that the use of a number indicating a component in a particular drawing is not intended to limit the component in another drawing that bears the same number. Detailed Description of the Invention

[0009] A multilayer optical laminate is an optical structure comprising three or more material layers bonded together. These optical laminates may also be articles, meaning they may be used as is or combined with other layers or structures to form an article. Laminates can take on a wide variety of shapes and forms. In some cases, a multilayer optical laminate may include a combination of a relatively rigid or semi-rigid layer, such as a glass or polymer plate, and a flexible layer, such as a film. A wide variety of methods can be used to bond the layers together, and in many cases, an adhesive layer is used.

[0010] As more complex multilayer optical laminates are developed and used, the requirements for these laminates are becoming stricter. Laminates must not only have structural limitations—that is, they must not be structurally unsuitable due to abscission or other reasons—but they must also possess high light transmittance, which must be maintained under various conditions; in other words, laminates must not develop optical defects. The occurrence of optical defects such as bubbles, localized abscission, cloudiness, and discoloration in laminated glass is an undesirable phenomenon that negatively affects the visual quality of the laminate but does not affect its structural safety. These defects can occur due to many influences during the manufacturing of the laminate and / or during its lifespan.

[0011] Many of these defects can be addressed by the use of an adhesive layer. However, one defect in optical laminates that can be created by the use of an adhesive layer is a phenomenon described as "orange peel." In many academic fields, the term "orange peel defect" is used to describe various different situations, such as the rough surface of a metal sheet on an automobile or the rough surface of a poorly polished lens. In the field of optical laminates, it has a somewhat different but relevant meaning. One useful description of orange peel defects in optical laminates is presented in paragraph 0008 of U.S. Patent Application Publication 2014 / 0220286 (Honeycutt et al.). This paragraph describes a situation in which a PET (polyethylene terephthalate) film is laminated between glass plates using polyvinyl butyral (PVB). The explanation states, "A further problem associated with laminates containing a PET layer between two PVB sheets is the formation of another type of optical distortion called undulation or orange peel. When PET is laminated between two layers of PVB, the PET does not 'flow' like the PVB, and therefore, even if the degassing of the laminate is excellent, it may appear wavy or have a surface that looks like applesauce when laminated." In some cases, the orange peel effect may not manifest as a visual defect visible to the naked eye, but when light passes through the laminate, the emitted light may have an uneven surface. This can be observed by observing the reflected image of a linear object, such as a fluorescent tube, from the laminate. Reflection of linear light should have a smooth surface, whereas in examples showing orange peel, the surface of reflection of linear light has a textured or wavy surface. Therefore, it is desirable to have multilayer laminates that have little or no scattering of reflected light by the films contained in the laminate structure.

[0012] This disclosure provides a method for preparing a multilayer optical laminate free from defects such as orange peel by laminating a film between optical substrates such as glass without using an adhesive layer. In this disclosure, the film is laminated directly onto the glass, and the film plays a role in bonding the optical substrates together without generating optical defects such as orange peel.

[0013] Unless otherwise indicated, all numbers used in this specification and in the claims to represent structural dimensions, quantities, and physical properties shall be understood in all cases to be modified by the term “approximately.” Therefore, unless otherwise indicated, the numerical parameters described in the above specification and in the appended claims are approximations that may vary depending on the desired properties that a person skilled in the art would seek to obtain using the teachings disclosed herein. Numerical ranges described by endpoints include all numbers encompassed within that range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range.

[0014] As used herein and in the appended claims, the singular forms "a," "an," and "the" include embodiments having multiple references unless otherwise specified. For example, "layer" includes embodiments having one or more layers. As used herein and in the appended claims, the term "or" is usually used to include "and / or" unless otherwise specified.

[0015] As used herein, the term “adjacent” refers to two layers that are adjacent to another layer. Adjacent layers may be in direct contact with each other, or there may be an intervening layer. There is no empty space between adjacent layers.

[0016] The terms "room temperature" and "ambient temperature" are used interchangeably and refer to their traditional meanings, namely temperatures between 20 and 25°C.

[0017] Unless otherwise specified, "optically transparent" means a layer, film, or article having high light transmittance over at least a portion of the visible light spectrum (approximately 400 to 700 nm). Typically, an optically transparent layer, film, or article has a luminous transmittance of at least 90%.

[0018] Unless otherwise indicated, the term "optically transparent" refers to a layer, film, or article that exhibits high light transmittance over at least a portion of the visible light spectrum (about 400 nm to about 700 nm) and exhibits low haze. Typically, an optically transparent layer, film, or article has a visible light transmittance value of at least 90%, often at least 95%, and a haze value of 5% or less, often 2% or less. Luminous transmittance and haze can be measured using techniques as described in ASTM D1003-11.

[0019] The term "alkyl" refers to a monovalent group that is a radical of an alkane, which is a saturated hydrocarbon. Alkyl can be linear, branched, cyclic, or a combination thereof, and typically has 1 to 20 carbon atoms. In some embodiments, the alkyl group contains 1 to 18, 1 to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, and ethylhexyl.

[0020] The term "aryl" refers to a monovalent group that is aromatic and carbocyclic. Aryl can have 1 to 5 rings connected or fused to an aromatic ring. Other cyclic structures may be aromatic, non-aromatic, or a combination thereof. Examples of aryl groups include, but are not limited to, phenyl, biphenyl, terphenyl, anthryl, naphthyl, acenaphthyl, anthraquinonyl, phenanthryl, anthracenyl, pyrenyl, perylenyl, and fluorenyl.

[0021] The term "alkylene" refers to a divalent radical derived from an alkane. The alkylene may be linear, branched, cyclic, or a combination thereof. The alkylene typically has 1 to 20 carbon atoms. In some embodiments, the alkylene contains 1 to 18, 1 to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. The radical centers of the alkylene may be on the same carbon atom (i.e., an alkylidene) or on different carbon atoms.

[0022] The term "arylene" refers to a divalent group that is carbocyclic and aromatic. This group has 1 to 5 rings that are connected, fused, or a combination thereof. Other rings may be aromatic, non-aromatic, or a combination thereof. In some embodiments, the arylene group has up to 5 rings, up to 4 rings, up to 3 rings, up to 2 rings, or one aromatic ring. For example, the arylene group may be phenylene.

[0023] The term "aralkylene" refers to a divalent group of the formula -R a -Ar a -[wherein R a is alkylene, and Ar a is arylene (that is, alkylene is bonded to arylene).]

[0024] The term "alkoxy" means a monovalent group of the formula -O-R, wherein R is an alkyl group.

[0025] Methods for preparing laminate articles are disclosed herein. These methods include forming a multilayer structure; placing the multilayer structure in a vacuum chamber; applying a vacuum to the vacuum chamber containing the multilayer structure; releasing the vacuum from the vacuum chamber; removing the multilayer structure from the vacuum chamber; placing the multilayer structure in a device capable of supplying heat and / or pressure; raising and maintaining a temperature while applying a pressure higher than atmospheric pressure to the multilayer structure; then lowering the temperature; and releasing the pressure to form an optically transparent multilayer article.

[0026] A multilayer structure is prepared by providing a first glass substrate having a first main surface and a second main surface, wherein the second main surface does not contain an adhesive layer; providing a second glass substrate having a first main surface and a second main surface, wherein the first main surface does not contain an adhesive layer; and providing a first optical film having a first main surface and a second main surface, wherein the first and second main surfaces do not contain an adhesive layer. The first optical film comprises one or more layers of polymer material. The multilayer structure is prepared by arranging the first glass substrate, the first optical film, and the second glass substrate such that the second main surface of the first glass substrate is close to the first main surface of the first optical film, and the second main surface of the first optical film is close to the first main surface of the second glass substrate.

[0027] When the multilayer structure is removed from the vacuum chamber, the second main surface of the first glass substrate comes into direct surface contact with the first main surface of the first optical film, and the first main surface of the second glass substrate comes into direct surface contact with the second main surface of the first optical film.

[0028] If the multilayer structure is placed within a device capable of supplying heat and / or pressure, the temperature is raised and maintained to or above the softening temperature of the polymer material on the first and second main surfaces of the first optical film. If the polymer material on the first and second main surfaces of the first optical film contains different materials, the temperature is raised and maintained to or above the higher softening temperature of the different materials.

[0029] The multilayer structure can be assembled in various ways and then placed in a vacuum chamber. In some embodiments, preparing the multilayer structure involves arranging first and second glass substrates and a first optical film within a frame, the frame including the first and second plates such that the first plate is in contact with the first principal surface of the first glass substrate and the second plate is in contact with the second principal surface of the second glass substrate. In some of these embodiments, each plate includes at least one orifice, which is connected to a compressed air pressure source, the orifice of the first plate is in fluid contact with the first glass substrate, and the orifice of the second plate is in fluid contact with the second glass substrate, and applying a pressure higher than atmospheric pressure to the multilayer structure involves applying compressed air pressure through the orifices of the first and second plates.

[0030] A wide variety of glass substrates are suitable. The glass substrates must be thick enough to make them rigid and optically transparent. The thickness of the glass substrate depends on various factors, such as the desired total thickness of the multilayer article formed. Typically, it is desirable that the formed multilayer article has a thickness of 2.5 millimeters or less.

[0031] A wide variety of optical films are suitable for use in the methods of this disclosure. As used herein, the term “optical film” refers to a film that can be used to produce an optical effect. Optical films are typically polymer-containing films, which may be single-layer or multi-layer. Optical films are flexible and may be of any suitable thickness. Optical films are often at least partially transparent, reflective, anti-reflective, polarizing, optically transparent, or diffusive to certain wavelengths of the electromagnetic spectrum (e.g., wavelengths in the visible, ultraviolet, or infrared regions of the electromagnetic spectrum). Exemplary optical films include, but are not limited to, visible light specular films, colored specular films, sunlight reflective films, infrared reflective films, ultraviolet reflective films, brightness-enhancing films, reflective polarizing films (such as dual brightness-enhancing films), absorptive polarizing films, optically transparent films, colored films, and anti-reflective films.

[0032] Some optical films have multiple layers, such as multiple layers of polymer-containing material (e.g., polymers containing or not containing dyes), or multiple layers of metal-containing material and polymer material. Some optical films have alternating layers of polymer material with different refractive indices. Other optical films have alternating polymer layers and metal-containing layers. Exemplary optical films are described in the following patents: U.S. Patent No. 6,049,419 (Wheatley et al.); U.S. Patent No. 5,223,465 (Wheatley et al.); U.S. Patent No. 5,882,774 (Jonza et al.); U.S. Patent No. 6,049,419 (Wheatley et al.); U.S. Reissue Patent No. 34,605 ​​(Schrenk et al.); U.S. Patent No. 5,579,162 (Bjornard et al.); and U.S. Patent No. 5,360,659 (Arends et al.).

[0033] In some particularly preferred embodiments, the first optical film includes a multilayer polarizing film. A wide variety of such films are suitable. Among the preferred multilayer polarizing films are those containing alternating layers of polyethylene terephthalate and polyethylene naphthalate.

[0034] A wide range of temperatures and pressures can be used with the multilayer optical laminates of this disclosure. In some embodiments, it may be desirable to raise and maintain the temperature of a device capable of supplying heat and / or pressure to at least 120°C for at least 30 minutes. In other embodiments, it may be desirable to raise and maintain the temperature of a device capable of supplying heat and / or pressure to at least 150°C for at least 1 hour. A wide range of pressures is also preferable. In some specific embodiments, the pressure is at least 5 kg / cm². 2 That is the case.

[0035] In some embodiments, the method further includes providing a third glass substrate having a first principal surface and a second principal surface, wherein the first principal surface of the third glass substrate does not contain an adhesive layer, and providing a second optical film having a first principal surface and a second principal surface, wherein the first principal surface and the second principal surface do not contain an adhesive layer. In these embodiments, preparing the multilayer structure further includes arranging the second optical film and the third glass substrate such that the first principal surface of the second optical film is close to the second principal surface of the second glass substrate, and the second principal surface of the second optical film is close to the first principal surface of the third glass substrate. Like the first optical film, the second optical film comprises one or more layers of polymer material. The first optical film and the second optical film may be the same, but typically they are different films. If the polymer materials of the first and second optical films contain different materials, the temperature is raised and maintained to or above the higher softening temperature of the different materials.

[0036] In other embodiments, the method further includes providing a third glass substrate having a first principal surface and a second principal surface, wherein the first principal surface of the third glass substrate does not contain an adhesive layer; providing a second optical film having a first principal surface and a second principal surface, wherein the first and second principal surfaces do not contain an adhesive layer; and providing a third optical film having a first principal surface and a second principal surface, wherein the first and second principal surfaces do not contain an adhesive layer. In these embodiments, preparing the multilayer structure further includes arranging the second optical film, the third optical film, and the third glass substrate such that the first principal surface of the second optical film is adjacent to the second principal surface of the second glass substrate, the first principal surface of the third optical film is adjacent to the second principal surface of the second optical film, and the second principal surface of the third optical film is adjacent to the first principal surface of the third glass substrate. Like the first optical film, the second and third optical films include one or more layers of polymer material. The first, second, and third optical films may be the same, but typically they are different films. If the polymer material of the optical film contains different materials, the temperature is raised and maintained to or above the higher softening temperature of the different materials.

[0037] In embodiments including additional films and glass substrates, the overall method remains the same. In these embodiments, the multilayer structure is prepared and processed in the same manner as described above.

[0038] Furthermore, a method for preparing a laminated article is also disclosed herein, wherein one or more of the surfaces of the glass substrate involved in the formation of the laminate are treated surfaces. The treated surfaces still do not contain an adhesive layer. Various surface treatments are suitable for forming the treated surfaces.

[0039] This method is similar to the method described above. These methods include forming a multilayer structure, placing the multilayer structure in a vacuum chamber, applying a vacuum to the vacuum chamber containing the multilayer structure, releasing the vacuum from the vacuum chamber, removing the multilayer structure from the vacuum chamber, placing the multilayer structure in a device capable of supplying heat and / or pressure, raising and maintaining the temperature of the multilayer structure while applying a pressure higher than atmospheric pressure, then lowering the temperature, and releasing the pressure to form an optically transparent multilayer article.

[0040] A multilayer structure is prepared by providing a first glass substrate having a first main surface and a second main surface, wherein the second main surface is a treated surface that does not contain an adhesive layer; providing a second glass substrate having a first main surface and a second main surface, wherein the first main surface is a treated surface that does not contain an adhesive layer; and providing a first optical film having a first main surface and a second main surface, wherein the first and second main surfaces do not contain an adhesive layer. The first optical film comprises one or more layers of polymer material. The multilayer structure is prepared by arranging the first glass substrate, the first optical film, and the second glass substrate such that the second main surface of the first glass substrate is close to the first main surface of the first optical film, and the second main surface of the first optical film is close to the first main surface of the second glass substrate.

[0041] When the multilayer structure is removed from the vacuum chamber, the second main surface of the first glass substrate comes into direct surface contact with the first main surface of the first optical film, and the first main surface of the second glass substrate comes into direct surface contact with the second main surface of the first optical film.

[0042] If the multilayer structure is placed within a device capable of supplying heat and / or pressure, the temperature is raised and maintained to or above the softening temperature of the polymer material on the first and second main surfaces of the first optical film. If the polymer material on the first and second main surfaces of the first optical film contains different materials, the temperature is raised and maintained to or above the higher softening temperature of the different materials.

[0043] The multilayer structure can be assembled in various ways and then placed in a vacuum chamber. In some embodiments, preparing the multilayer structure involves arranging first and second glass substrates and a first optical film within a frame, the frame including the first and second plates such that the first plate is in contact with the first principal surface of the first glass substrate and the second plate is in contact with the second principal surface of the second glass substrate. In some of these embodiments, each plate includes at least one orifice, which is connected to a compressed air pressure source, the orifice of the first plate is in fluid contact with the first glass substrate, and the orifice of the second plate is in fluid contact with the second glass substrate, and applying a pressure higher than atmospheric pressure to the multilayer structure involves applying compressed air pressure through the orifices of the first and second plates.

[0044] A wide variety of glass substrates are suitable. The glass substrates must be thick enough to make them rigid and optically transparent. The thickness of the glass substrate depends on various factors, such as the desired total thickness of the multilayer article formed. Typically, it is desirable that the formed multilayer article has a thickness of 2.5 millimeters or less.

[0045] In some particularly preferred embodiments, the first optical film includes a multilayer polarizing film. A wide variety of such films are suitable. Among the preferred multilayer polarizing films are those containing alternating layers of polyethylene terephthalate and polyethylene naphthalate.

[0046] A wide range of temperatures and pressures can be used with the multilayer optical laminates of this disclosure. In some embodiments, it may be desirable to raise and maintain the temperature of a device capable of supplying heat and / or pressure to at least 120°C for at least 30 minutes. In other embodiments, it may be desirable to raise and maintain the temperature of a device capable of supplying heat and / or pressure to at least 150°C for at least 1 hour. A wide range of pressures is also preferable. In some specific embodiments, the pressure is at least 5 kg / cm². 2 That is the case.

[0047] In some embodiments, the method further includes providing a third glass substrate having a first principal surface and a second principal surface, wherein the first principal surface of the third glass substrate is a treated surface that does not contain an adhesive layer, and providing a second optical film having a first principal surface and a second principal surface, wherein the first and second principal surfaces do not contain an adhesive layer. In these embodiments, preparing the multilayer structure further includes arranging the second optical film and the third glass substrate such that the first principal surface of the second optical film is close to the second principal surface of the second glass substrate, and the second principal surface of the second optical film is close to the first principal surface of the third glass substrate. Like the first optical film, the second optical film comprises one or more layers of polymer material. The first optical film and the second optical film may be the same, but typically they are different films. If the polymer materials of the first and second optical films contain different materials, the temperature is raised and maintained to or above the higher softening temperature of the different materials.

[0048] In other embodiments, the method further includes providing a third glass substrate having a first principal surface and a second principal surface, wherein the first principal surface of the third glass substrate is a treated surface that does not contain an adhesive layer; providing a second optical film having a first principal surface and a second principal surface, wherein the first and second principal surfaces do not contain an adhesive layer; and providing a third optical film having a first principal surface and a second principal surface, wherein the first and second principal surfaces do not contain an adhesive layer. In these embodiments, preparing the multilayer structure further includes arranging the second optical film, the third optical film, and the third glass substrate such that the first principal surface of the second optical film is adjacent to the second principal surface of the second glass substrate, the first principal surface of the third optical film is adjacent to the second principal surface of the second optical film, and the second principal surface of the third optical film is adjacent to the first principal surface of the third glass substrate. Like the first optical film, the second and third optical films include one or more layers of polymer material. The first, second, and third optical films may be the same, but typically they are different films. If the polymer material of the optical film contains different materials, the temperature is raised and maintained to or above the higher softening temperature of the different materials.

[0049] In embodiments including additional films and glass substrates, the overall method remains the same. In these embodiments, the multilayer structure is prepared and processed in the same manner as described above.

[0050] A wide variety of surface treatments are suitable for the methods of this disclosure. In some embodiments, the treated surfaces of first, second, and third glass substrates are prepared by a process comprising: providing a treatment solution; applying the treatment solution to the glass surface to form a continuous or discontinuous coating layer; and drying the continuous or discontinuous coating layer. The treatment solution comprises at least one silane coupling agent and a solvent.

[0051] A wide variety of silane coupling agents are suitable. Particularly suitable silane coupling agents have a general structure: Z3Si-AX[wherein each Z is an alkyl group or alkoxy group, provided that at least one Z is an alkoxy group, A is a divalent linking group containing an alkylene group, an arylene group, or an aralkylene group, and X is an amino group-NR] 1 A functional group selected from 2, in the formula, each R 1 [These are independently hydrogen atoms, alkyl or aryl groups, isocyanate groups, or epoxy groups.]

[0052] A wide variety of solvents are suitable for preparing the treatment solution, provided that the solvent can solubilize the silane coupling agent and is sufficiently volatile to be easily removed by drying. Suitable solvents include ketones such as acetone or MEK (methyl ethyl ketone); aromatic liquids such as benzene or toluene; esters such as ethyl acetate; alkanes such as hexane or heptane; alcohols such as methanol, ethanol, or propanol; ethers such as ethyl ether or THF (tetrahydrofuran); or halogenated alkanes such as methylene chloride or carbon tetrachloride.

[0053] Also disclosed are multilayer articles prepared using the above method. In some embodiments, the multilayer article comprises a first glass substrate having a first main surface and a second main surface, a second glass substrate having a first main surface and a second main surface, and a first optical film having a first main surface and a second main surface comprising one or more layers of polymer material, wherein the second main surface of the first glass substrate is interfacially bonded to the first main surface of the first optical film, the interfacial bond does not include an adhesive layer, the second main surface of the first optical film is interfacially bonded to the first main surface of the second glass substrate, the interfacial bond does not include an adhesive layer, the second main surface to the first glass substrate and the first main surface of the second glass substrate are treated or untreated surfaces, the treated surface includes a silane coupling agent treated surface, and the multilayer article is optically transparent.

[0054] In other embodiments, the multilayer article further comprises a second optical film having a first main surface and a second main surface, and a third glass substrate having a first main surface and a second main surface, wherein the second main surface of the second glass substrate is interfacially bonded to the first main surface of the second optical film, the interfacial bond does not include an adhesive layer, the second main surface of the second optical film is interfacially bonded to the first main surface of the third glass substrate, the interfacial bond does not include an adhesive layer, the second main surface of the second glass substrate and the first main surface of the third glass substrate are treated or untreated surfaces, the treated surface includes a silane coupling agent treated surface, the multilayer article is optically transparent and does not exhibit scattering of reflected light by the first optical film.

[0055] In yet another embodiment, the multilayer article further comprises a second optical film having a first main surface and a second main surface, a third optical film having a first main surface and a second main surface, and a third glass substrate having a first main surface and a second main surface, wherein the second main surface of the second glass substrate is interfacially bonded to the first main surface of the second optical film, the interfacial bond does not include an adhesive layer, the second main surface of the second optical film is interfacially bonded to the first main surface of the third optical film, the interfacial bond does not include an adhesive layer, the second main surface of the third optical film is interfacially bonded to the first main surface of the third glass substrate, the second main surface of the second glass substrate and the first main surface of the third glass substrate are treated or untreated surfaces, the treated surface includes a silane coupling agent treated surface, the multilayer article is optically transparent and does not exhibit scattering of reflected light by the optical film.

[0056] Suitable glass substrates, optical films, and surface treatments are described in detail above. In some embodiments, the first optical film includes a multilayer polarizing film. In some of these embodiments, the multilayer polarizing film includes alternating layers of polyethylene terephthalate and polyethylene naphthalate.

[0057] In embodiments where one or more of the glass substrates comprises a treated surface, the treated surface has the general structure: Z₃Si-A-X [wherein each Z is an alkyl group or an alkoxy group, provided that at least one Z is an alkoxy group; A is a divalent linking group comprising an alkylene group, an arylene group, or an aralkylene group; and X is an amino group -NR 1 ₂, wherein each R 1 is independently a hydrogen atom, an alkyl or aryl group, an isocyanate group, or an epoxy group], and the treated surface is treated with a silane coupling agent having the above structure.

[0058] The methods and articles of the present disclosure may be further understood from the drawings. FIG. 1 shows an embodiment of the method of the present disclosure. In FIG. 1, an assembled multilayer structure includes a first glass substrate 10, a second glass substrate 20, and an optical film 30. The optical film 30 is held in place in proximity to the first glass substrate 10 and the second glass substrate 20 by clips 40. The assembled multilayer structure is placed in a vacuum chamber 60. Pressure plates 50 are placed on both sides of the assembled multilayer structure. The pressure plate 50 has an O-ring 51 and a compressed air line 55. This structure is subjected to process step A, in which a vacuum is applied to the vacuum chamber 60 to obtain a evacuated vacuum chamber 60'. The first glass substrate 10, the second glass substrate 20, and the optical film 30 are in contact and held together by the pressure plates 50 using compressed air provided by the compressed air lines 55, and the compressed air pressure is maintained by the O-rings 51. The optical film 30 is held by the clips 40. This structure is subjected to process step B, which comprises releasing the vacuum from the vacuum chamber 60', removing the multilayer assembly from the vacuum chamber, placing it in an oven 70, heating it to a temperature of at least 120°C, and then cooling it to room temperature. The first glass substrate 10, the second glass substrate 20, and the optical film 30 are in contact and held together by the pressure plates 50 using compressed air provided by the compressed air lines 55, and the compressed air pressure is maintained by the O-rings 51. The optical film 30 is held by the clips 40.

[0059] Figure 2 shows another embodiment of the method of the present disclosure. In Figure 2, the assembled multilayer structure includes a first glass substrate 110, a second glass substrate 120, a third glass substrate 180, and optical films 130 and 190. Optical film 130 is held in place by clips 140 in close proximity to the first glass substrate 110 and the second glass substrate 120, and optical film 190 is held in place by clips 140 in close proximity to the second glass substrate 120 and the third glass substrate 180. The assembled multilayer structure is placed in a vacuum chamber 160. Pressure plates 150 are placed on both sides of the assembled multilayer structure. The pressure plates 150 have O-rings 151 and compressed air tubes 155. The structure is subjected to process step A, in which a vacuum is applied to the vacuum chamber 160 to form a vacuum chamber 160'. The first glass substrate 110, optical film 130, second glass substrate 120, optical film 190, and third glass substrate 180 are in contact and held together by a pressure plate 150 using compressed air supplied by an air tube 155, with the compressed air pressure maintained by an O-ring 151. The optical films 130 and 190 are held by clips 140. This structure is subjected to process step B, which includes releasing the vacuum from the vacuum chamber 160', removing the multilayer assembly from the vacuum chamber, placing it in an oven 170, heating it to a temperature of at least 120°C, and then cooling it to room temperature. The first glass substrate 110, optical film 130, second glass substrate 120, optical film 190, and third glass substrate 180 are in contact and held together by a pressure plate 150 using compressed air supplied by an air tube 155, with the compressed air pressure maintained by an O-ring 151. The optical films 130 and 190 are held by clips 140.

[0060] Figure 3 shows another embodiment of the method of the present disclosure. In Figure 3, the assembled multilayer structure includes a first glass substrate 210, a second glass substrate 220, a third glass substrate 280, and optical films 230, 290, and 300. Optical film 230 is held in place by clips 240 in close proximity to the first glass substrate 210 and the second glass substrate 220, and optical films 290 and 300 are held in place by clips 240 in close proximity to the second glass substrate 220 and the third glass substrate 280. The assembled multilayer structure is placed in a vacuum chamber 260. Pressure plates 250 are placed on both sides of the assembled multilayer structure. The pressure plates 250 have O-rings 251 and compressed air tubes 255. The structure is subjected to process step A, which involves applying a vacuum to the vacuum chamber 260 to make it a vacuum chamber 260'. The first glass substrate 210, optical film 230, second glass substrate 220, optical film 290, optical film 300, and third glass substrate 280 are in contact and held together by a pressure plate 250 using compressed air supplied by an air tube 255, with the compressed air pressure maintained by an O-ring 251. The optical films 230, 290, and 300 are held by clips 240. This structure is subjected to process step B, which includes releasing the vacuum from the vacuum chamber 260', removing the multilayer assembly from the vacuum chamber, placing it in an oven 270, heating it to a temperature of at least 120°C, and then cooling it to room temperature. The first glass substrate 210, optical film 230, second glass substrate 220, optical film 290, optical film 300, and third glass substrate 280 are in contact and held together by a pressure plate 250 using compressed air supplied by an air tube 255, with the compressed air pressure maintained by an O-ring 251. The optical films 230, 290, and 300 are held in place by the clip 240.

[0061] This disclosure includes the following embodiments.

[0062] One embodiment is a method for preparing a laminated article. Embodiment 1 is a method for preparing a laminated article, comprising: providing a first glass substrate having a first main surface and a second main surface, wherein the second main surface does not contain an adhesive layer; providing a second glass substrate having a first main surface and a second main surface, wherein the first main surface does not contain an adhesive layer; providing a first optical film having a first main surface and a second main surface containing one or more layers of polymer material, wherein the first and second main surfaces do not contain an adhesive layer; preparing a multilayer structure by arranging the first glass substrate, the first optical film, and the second glass substrate such that the second main surface of the first glass substrate is close to the first main surface of the first optical film, and the second main surface of the first optical film is close to the first main surface of the second glass substrate; arranging the multilayer structure in a vacuum chamber; and ensuring that the second main surface of the first glass substrate is in direct surface contact with the first main surface of the first optical film, and the second glass The preparation method includes: applying a vacuum to a vacuum chamber containing a multilayer structure such that the first main surface of a substrate is in direct surface contact with the second main surface of a first optical film; releasing the vacuum from the vacuum chamber; removing the multilayer structure from the vacuum chamber and placing the multilayer structure in a device capable of supplying heat and / or pressure; raising and maintaining the temperature of the device capable of supplying heat and / or pressure to the softening temperature of the polymer material of the first and second main surfaces of the first optical film, or a temperature above that, while applying a pressure higher than atmospheric pressure to the multilayer structure; lowering the temperature of the device capable of supplying heat and / or pressure to room temperature; and releasing the pressure higher than atmospheric pressure from the multilayer structure to form a multilayer article that is optically transparent and does not exhibit scattering of reflected light from the first optical film.

[0063] Embodiment 2 is the method according to Embodiment 1, further comprising providing a third glass substrate having a first main surface and a second main surface, wherein the first main surface of the third glass substrate does not contain an adhesive layer, and providing a second optical film having a first main surface and a second main surface containing one or more layers of polymer material, wherein the first main surface and the second main surface do not contain an adhesive layer, and further comprising arranging the second optical film and the third glass substrate such that the first main surface of the second optical film is close to the second main surface of the second glass substrate and the second main surface of the second optical film is close to the first main surface of the third glass substrate.

[0064] Embodiment 3 is a method of the embodiment that further includes providing a third glass substrate having a first main surface and a second main surface, wherein the first main surface of the third glass substrate does not contain an adhesive layer; providing a second optical film having a first main surface and a second main surface containing one or more layers of polymer material, wherein the first main surface and the second main surface do not contain an adhesive layer; and providing a third optical film having a first main surface and a second main surface containing one or more layers of polymer material, wherein the first main surface and the second main surface do not contain an adhesive layer, and further includes arranging the second optical film, the third optical film and the third glass substrate such that the first main surface of the second optical film is close to the second main surface of the second glass substrate, the first main surface of the third optical film is close to the second main surface of the second optical film, and the second main surface of the third optical film is close to the first main surface of the third glass substrate.

[0065] Embodiment 4 is the method according to any one of Embodiments 1 to 3, wherein preparing a multilayer structure involves arranging first and second glass substrates and a first optical film within a frame, the frame comprising first and second plates such that the first plate contacts the first main surface of the first glass substrate and the second plate contacts the second main surface of the second glass substrate.

[0066] Embodiment 5 is the method of Embodiment 4, wherein each plate includes at least one orifice, the orifice being connected to a compressed air pressure source, the orifice of the first plate being in fluid contact with a first glass substrate, the orifice of the second plate being in fluid contact with a second glass substrate, and applying a pressure higher than atmospheric pressure to the multilayer structure is achieved by applying compressed air pressure through the orifices of the first and second plates.

[0067] Embodiment 6 is the method according to any one of Embodiments 1 to 5, wherein the first optical film includes a multilayer polarizing film.

[0068] Embodiment 7 is the method according to Embodiment 6, wherein the multilayer polarizing film includes alternating layers of polyethylene terephthalate and polyethylene naphthalate.

[0069] Embodiment 8 is a method according to any one of Embodiments 1 to 7, wherein raising and maintaining the temperature of a device capable of supplying heat and / or pressure includes raising the temperature to at least 120°C for at least 30 minutes.

[0070] Embodiment 9 is a device capable of supplying heat and / or pressure, wherein the pressure of the device is at least 5 kg / cm². 2 This is a method according to any one of embodiments 1 to 8, which is raised to a certain level.

[0071] Embodiment 10 is a method for preparing a laminate article, comprising: providing a first glass substrate having a first main surface and a second main surface, wherein the second main surface is a treated surface that does not contain an adhesive layer; providing a second glass substrate having a first main surface and a second main surface, wherein the first main surface is a treated surface that does not contain an adhesive layer; providing a first optical film having a first main surface and a second main surface containing one or more layers of polymer material, wherein the first and second main surfaces do not contain an adhesive layer; preparing a multilayer structure by arranging the first glass substrate, the first optical film, and the second glass substrate such that the second main surface of the first glass substrate is close to the first main surface of the first optical film, and the second main surface of the first optical film is close to the first main surface of the second glass substrate; arranging the multilayer structure in a vacuum chamber; and ensuring that the second main surface of the first glass substrate is in direct contact with the first main surface of the first optical film. The preparation method includes: applying a vacuum to a vacuum chamber containing a multilayer structure so that the first main surface of the second glass substrate is in direct surface contact with the second main surface of the first optical film; releasing the vacuum from the vacuum chamber; removing the multilayer structure from the vacuum chamber and placing the multilayer structure in a device capable of supplying heat and / or pressure; raising and maintaining the temperature of the device capable of supplying heat and / or pressure to the softening temperature of the polymer material of the first and second main surfaces of the first optical film, or a temperature above that, while applying a pressure higher than atmospheric pressure to the multilayer structure; lowering the temperature of the device capable of supplying heat and / or pressure to room temperature; and releasing the pressure higher than atmospheric pressure to the multilayer structure to form a multilayer article that is optically transparent and does not exhibit scattering of reflected light from the first optical film.

[0072] Embodiment 11 is the method according to Embodiment 10, wherein the treated surfaces of the first and second glass substrates are prepared by a process comprising: providing a treatment solution containing at least one silane coupling agent and a solvent; applying the treatment solution to the glass surface to form a continuous or discontinuous coating layer; and drying the continuous or discontinuous coating layer.

[0073] Embodiment 12 describes a silane coupling agent with a general structure: Z3Si-AX[wherein each Z is an alkyl group or alkoxy group, provided that at least one Z is an alkoxy group, A is a divalent coupling group comprising an alkylene group, an arylene group, or an aralkylene group, and X is an amino group-NR] 1 A functional group selected from 2, in the formula, each R 1 The method according to Embodiment 11, wherein is independently a hydrogen atom, an alkyl or aryl group, an isocyanate group, or an epoxy group.

[0074] Embodiment 13 is a method according to any one of Embodiments 10 to 12, further comprising providing a third glass substrate having a first main surface and a second main surface, wherein the first main surface of the third glass substrate is a treated surface that does not contain an adhesive layer, and providing a second optical film having a first main surface and a second main surface containing one or more layers of polymer material, wherein the first main surface and the second main surface do not contain an adhesive layer, and further comprising arranging the second optical film and the third glass substrate such that the first main surface of the second optical film is close to the second main surface of the second glass substrate and the second main surface of the second optical film is close to the first main surface of the third glass substrate.

[0075] Embodiment 14 is a method according to any one of Embodiments 10 to 12, further comprising: providing a third glass substrate having a first main surface and a second main surface, wherein the first main surface of the third glass substrate is a treated surface that does not contain an adhesive layer; providing a second optical film having a first main surface and a second main surface containing one or more layers of polymer material, wherein the first main surface and the second main surface do not contain an adhesive layer; and providing a third optical film having a first main surface and a second main surface containing one or more layers of polymer material, wherein the first main surface and the second main surface do not contain an adhesive layer, wherein preparing a multilayer structure further comprises arranging the second optical film, the third optical film, and the third glass substrate such that the first main surface of the second optical film is close to the second main surface of the second glass substrate, the first main surface of the third optical film is close to the second main surface of the second optical film, and the second main surface of the third optical film is close to the first main surface of the third glass substrate.

[0076] Embodiment 15 is a method according to any one of Embodiments 10 to 14, wherein preparing a multilayer structure involves arranging first and second glass substrates and a first optical film within a frame, the frame comprising the first and second plates such that the first plate contacts the first main surface of the first glass substrate and the second plate contacts the second main surface of the second glass substrate.

[0077] Embodiment 16 is the method of Embodiment 15, wherein each plate includes at least one orifice, the orifice being connected to a compressed air pressure source, the orifice of the first plate being in fluid contact with a first glass substrate, the orifice of the second plate being in fluid contact with a second glass substrate, and applying a pressure higher than atmospheric pressure to the multilayer structure is achieved by applying compressed air pressure through the orifices of the first and second plates.

[0078] Embodiment 17 is a method according to any one of Embodiments 10 to 16, wherein the first optical film includes a multilayer polarizing film.

[0079] Embodiment 18 is the method of Embodiment 17, wherein the multilayer polarizing film includes alternating layers of polyethylene terephthalate and polyethylene naphthalate.

[0080] Embodiment 19 is a method according to any one of Embodiments 10 to 18, wherein raising and maintaining the temperature of a device capable of supplying heat and / or pressure includes raising the temperature to at least 120°C for at least 30 minutes.

[0081] Embodiment 20 is a device capable of supplying heat and / or pressure, wherein the pressure of the device is at least 5 kg / cm². 2 This is a method according to any one of embodiments 10 to 19, which is raised to a certain level.

[0082] Multilayer articles are also disclosed. Embodiment 21 includes a multilayer article comprising: a first glass substrate having a first main surface and a second main surface; a second glass substrate having a first main surface and a second main surface; and a first optical film having a first main surface and a second main surface comprising one or more layers of polymer material, wherein the second main surface of the first glass substrate is interfacially bonded to the first main surface of the first optical film, the interfacial bond does not include an adhesive layer; the second main surface of the first optical film is interfacially bonded to the first main surface of the second glass substrate, the interfacial bond does not include an adhesive layer; the second main surface to the first glass substrate and the first main surface of the second glass substrate are treated or untreated surfaces, the treated surface includes a silane coupling agent treated surface; the multilayer article is optically transparent and does not exhibit scattering of reflected light by the first optical film.

[0083] Embodiment 22 is a multilayer article according to Embodiment 21, wherein the article further comprises a second optical film having a first main surface and a second main surface, and a third glass substrate having a first main surface and a second main surface, wherein the second main surface of the second glass substrate is interfacially bonded to the first main surface of the second optical film, the interfacial bond does not include an adhesive layer, the second main surface of the second optical film is interfacially bonded to the first main surface of the third glass substrate, the interfacial bond does not include an adhesive layer, the second main surface of the second glass substrate and the first main surface of the third glass substrate are treated or untreated surfaces, the treated surface includes a silane coupling agent treated surface, the multilayer article is optically transparent and does not exhibit scattering of reflected light by the optical film.

[0084] Embodiment 23 is a multilayer article according to Embodiment 21, wherein the article further comprises a second optical film having a first main surface and a second main surface, a third optical film having a first main surface and a second main surface, and a third glass substrate having a first main surface and a second main surface, wherein the second main surface of the second glass substrate is interfacially bonded to the first main surface of the second optical film, the interfacial bond does not include an adhesive layer, the second main surface of the second optical film is interfacially bonded to the first main surface of the third optical film, the interfacial bond does not include an adhesive layer, the second main surface of the third optical film is interfacially bonded to the first main surface of the third glass substrate, the second main surface of the second glass substrate and the first main surface of the third glass substrate are treated or untreated surfaces, the treated surface includes a silane coupling agent treated surface, the multilayer article is optically transparent and does not exhibit scattering of reflected light by the optical film.

[0085] Embodiment 24 is a multilayer article according to any one of Embodiments 21 to 23, wherein the first optical film includes a multilayer polarizing film.

[0086] Embodiment 25 is a multilayer article according to Embodiment 24, wherein the multilayer polarizing film includes alternating layers of polyethylene terephthalate and polyethylene naphthalate.

[0087] Embodiment 26 includes a treated surface on the second main surface of the first glass substrate and the first main surface of the second glass substrate, wherein the treated surface has a general structure: Z3Si-AX[wherein each Z is an alkyl group or alkoxy group, provided that at least one Z is an alkoxy group, A is a divalent linking group including an alkylene group, an arylene group, or an aralkylene group, and X is an amino group-NR 1 A functional group selected from 2, in the formula, each R 1 The multilayer article according to any one of embodiments 21 to 25 includes a treated surface that has been treated with a silane coupling agent having independently a hydrogen atom, an alkyl or aryl group, an isocyanate group, or an epoxy group. [Examples]

[0088] These examples are for illustrative purposes only and are not intended to limit the scope of the appended claims. All parts, percentages, ratios, etc., in the examples and elsewhere in this specification are by weight unless otherwise indicated. The solvents and other reagents used were obtained from Sigma-Aldrich Chemical Company (Milwaukee, Wisconsin) unless otherwise noted. The following abbreviations are used: mm = millimeter, Pa = Pascal, min = minute, hr = hour, Kg = kilogram, cm = centimeter.

[0089] [Table 1]

[0090] Test method Yuzu skin test The orange peel test was performed by observing the reflected image generated when a linear fluorescent tube was illuminated on the structure described below. The presence or absence of orange peel was easily perceptible visually. The test results were reported as "Good" if no orange peel was observed, or "NG" if orange peel was observed.

[0091] Bonding test The bonding test indicates whether the bonding between layers is strong enough to withstand the waterjet cutting process. The data is presented as "Good" if no delamination occurs during the waterjet cutting process, "Acceptable" if the waterjet cutting was successful but some delamination occurred during the process, or "NG" if the structure could not withstand the waterjet cutting.

[0092] Warping test Warping refers to the flatness of a 300mm diameter stack before waterjet cutting and is detected by visual observation. The data is presented as "Good" if no warping is observed, "Acceptable" if some warping is observed, or "NG" if the structure is severely distorted.

[0093] Examples 1-2 and Comparative Examples C1-C2 An example of a flat lens optical article containing a laminated stack of three glass plates and three optical films. In each case, the formed optical article had a diameter of 34 mm and a thickness of approximately 2.5 mm. The article was manufactured by assembling and fabricating the laminated stack structure.

[0094] The assembly and fabrication of laminate stack structures were generalized: For each item, the laminate stack assembly was arranged in the following order: Glass plate / AP film / PFS / PF / plate film / glass plate.

[0095] The general procedure for assembling and fabricating laminate stack assemblies was as follows:

[0096] 1) Each film was attached to its own ring frame. 2) The glass plate and the film with a ring frame were sequentially placed in a vacuum chamber between two 30 mm thick aluminum press plates equipped with O-rings, sealing the aluminum press plates to the glass plate, and the entire structure was held together between the two aluminum press plates with bolts. 3) The vacuum chamber was pumped down to a pressure of 50 Pa, and the layers of the assembly were pressed together with the press plate. 4) Break the vacuum and remove the stack along with the press plate. 5) Place all the stacks together in an air-circulating oven for 1 hour. 6) Remove the stack and allow it to cool to room temperature. 7) Cut out the stack along the edge of the glass. 8) Cut to the final diameter (34 mm) using a water jet.

[0097] Comparative Example C1 For Comparative Example C1, the assemblies were joined using OCA so that they were in the following order: Glass plate / OCA / AP film / OCA / PFS / OCA / PF / OCA / Plate film / OCA / Glass plate.

[0098] The resulting structure failed the yuzu peel test (described above), and no further testing was conducted.

[0099] Examples 1-2 and Comparative Example C2 In Examples 1 and 2 and Comparative Example C2, OCA was not used. The difference between them is that in Examples 1 and 2, immediately before the vacuum in the vacuum chamber was broken, compressed air pressure (5 kg / cm²) was applied to the two outer glass plates of the structure through the inlet of the aluminum press plate. 2The result was the application of compressed air pressure. In Comparative Example C2, compressed air pressure was not applied. In Example 1 and Comparative Example C2, the stack was heated at a temperature of 150°C for 1 hour, and in Example 2, the stack was heated at a temperature of 100°C for 1 hour. A summary of these conditions, as well as the results of the orange peel test, bonding test, and warping test (described above), are shown in Table 1.

[0100] [Table 2]

Claims

1. A multilayer article comprising a first glass substrate, a second glass substrate, and a multilayer polarizing film disposed between the first and second glass substrates and interfacially bonded to the first and second glass substrates, The interfacial bond does not include a heat-activated adhesive layer containing polyvinyl butyral, and the multilayer polarizing film is directly bonded to the first glass substrate and the second glass substrate. The multilayer article has a visible transmittance of 90% or more and a haze of 5% or less, in accordance with ASTM D1003-11. Multilayer articles.

2. The multilayer article according to claim 1, wherein the multilayer polarizing film includes alternating layers of polyethylene terephthalate and polyethylene naphthalate.

3. The main surface of the first glass substrate on the multilayer polarizing film side and the main surface of the second glass substrate on the multilayer polarizing film side include a treated surface, and the treated surface has a general structure: Z ３ Si-A-X [wherein each Z is an alkyl group or alkoxy group, provided that at least one Z is an alkoxy group, A is a divalent linking group containing an alkylene group, an arylene group, or an aralkylene group, and X is an amino group-NR １ ２ A functional group selected from, where each R in the formula １ The multilayer article according to claim 1 or 2, comprising a treated surface treated with a silane coupling agent having independently a hydrogen atom, an alkyl or aryl group, an isocyanate group, or an epoxy group.

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