Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/10009—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets
  • B32B17/10036—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets comprising two outer glass sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/10165—Functional features of the laminated safety glass or glazing
  • B32B17/10174—Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/10165—Functional features of the laminated safety glass or glazing
  • B32B17/10431—Specific parts for the modulation of light incorporated into the laminated safety glass or glazing
  • B32B17/10467—Variable transmission
  • B32B17/10495—Variable transmission optoelectronic, i.e. optical valve
  • B32B17/10504—Liquid crystal layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/1055—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
  • B32B17/10761—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer containing vinyl acetal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/1055—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
  • B32B17/10788—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer containing ethylene vinylacetate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/10807—Making laminated safety glass or glazing; Apparatus therefor
  • B32B17/10889—Making laminated safety glass or glazing; Apparatus therefor shaping the sheets, e.g. by using a mould
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/133308—Support structures for LCD panels, e.g. frames or bezels
  • G02F1/133331—Cover glasses
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/40—Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/40—Properties of the layers or laminate having particular optical properties
  • B32B2307/414—Translucent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/40—Properties of the layers or laminate having particular optical properties
  • B32B2307/416—Reflective
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/536—Hardness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/546—Flexural strength; Flexion stiffness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2317/00—Animal or vegetable based
  • B32B2317/18—Cellulose, modified cellulose or cellulose derivatives, e.g. viscose
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2383/00—Polysiloxanes
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F2202/00—Materials and properties
  • G02F2202/28—Adhesive materials or arrangements

Definitions

• the invention relates to the field of laminated glazing.
• the invention will apply to all uses, in particular for buildings, such as exterior walls or partitions or other interior glazed surfaces, or for vehicles of the motor vehicle, bus, train, aircraft type. .
• a laminated glazing comprises two external glass substrates and at least one interlayer plastic film, very often polyvinyl butyral (PVB), making the two glass substrates integral.
• a laminated glazing may also comprise one or more other so-called functional films, such as, for example, infrared-reflecting films or liquid-crystal films.
• a laminated glazing incorporating a functional film sandwiched between the two outer glass substrates comprises between the two outer glass substrates, the functional film such as a liquid crystal cell, which is secured to the glass substrates by a PVB film coupled to each of the faces of the cell.
• a liquid crystal cell is in the form of a flexible film comprising liquid crystals encapsulated between two encapsulation sheets of polymeric material which are held at a constant distance by spacers such as glass beads. Each polymeric encapsulation sheet is provided with an electrode. When a voltage is applied to the electrodes, the liquid crystals change orientation and modify the light transmission through the cell, the glazing provided with the liquid crystal cell changing from a clear state to a dark state, or vice versa.
• the term "light state, dark state” means that the glazing has in its light state a light transmission in the visible greater than the light transmission that it has in its dark state.
• Liquid crystal cells are used in particular in certain building applications with flat glass.
• This technology has also recently been of interest to the automotive sector, for which the glazing requires darkening of the glass, such as for sunroofs, rear windows, sides or the gradient bands of the upper part of a windshield.
• the glazing is curved, and the lamination of functional films other than PVB does not prove to be so simple.
• the flexibility of functional films (liquid crystal or other), which are flexible, allows them a priori to marry a curved shape relatively easily.
• the bending actually generates significant visual defects.
• curved glazing is curved in two directions.
• the functional film although flexible, must deform locally in two directions to fit the curved shape, which is ultimately difficult.
• Significant visual defects emerge, such as wrinkling of the film in certain places, in particular mainly at the edges of the glazing. These defects are not aesthetically acceptable.
• the method of manufacturing laminated glazing involves high pressures and temperatures. These stresses can lead, in the case of functional liquid crystal films, to local deformations of the polymer sheets for encapsulating the liquid crystal cell, in particular an enlargement of the thickness of the cell. These deformations generate a local modification of the orientation of the liquid crystals, which is further accentuated when the glazing is curved. This results in an inhomogeneity in light transmission for the glazing, further manifesting itself visibly, by the presence of dark zones on a glazing which is normally light, or conversely the presence of light zones on a glazing which is normally dark.
• the object of the invention is therefore to propose a laminated glazing comprising at least one flexible functional film which is laminated with lamination inserts, the laminated glazing not having the aforementioned drawbacks such as optical defects of the fold type, or the presence of inhomogeneous zones in light transmission when the flexible functional film is liquid crystal.
• the laminated glazing comprises at least a first glass substrate and a second glass substrate, at least one functional film placed between the two glass substrates, as well as at least a first interlayer lamination film between the first glass substrate and the functional film, and at least one second interlayer lamination film between the second glass substrate and the functional film (the functional film being flexible when handled during the glazing lamination manufacturing process).
• the functional film comprises at least one layer of a transparent adhesive material (also called OCA for "Optical Clear Adhesive" in English) which is viscoelastic so as to be able to deform in thickness during the lamination process of the glazing .
• the OCA thus integrated into the flexible functional film, is not solid.
• the OCA has a viscoelasticity such that it is able to vary locally in thickness when the functional film undergoes deformation stresses during the glazing lamination process.
• the term "functional film” means a film which gives the glazing at least one technical function, such as a solar control film (for example absorption and/or reflection of infrared), a protective film against radiation ultraviolet. It can also be an active film such as a film allowing the control of the opacity and/or of the light transmission, or even a heating film, etc.
• the qualifier “transparent” for OCA means a material which has a light transmission greater than or equal to 80%, preferably at least 90%.
• the OCA is in liquid form before the manufacture of the functional film and is capable of crosslinking after its application to at least one (flexible) substrate which constitutes the support for the OCA and can possess the technical function or functions of the functional film. Another flexible substrate with a technical function can also be associated with them.
• the way in which liquid OCA crosslinks depends on its nature.
• the OCA can be crosslinked in particular by supplying energy of the ultraviolet type, or at room temperature with the addition of a hardener.
• Said at least one functional film integrated into the glazing is an independent film that can be handled as it is before the manufacture of the glazing. It is a ready-to-use film which is stacked with all the glass substrates and the laminating films in the usual way during the manufacture of laminated glazing.
• the functional film is used like any type of film of the PVB type in the usual manufacture of laminated glazing, in particular in the manufacture of curved laminated glazing.
• said at least one viscoelastic OCA layer has a hardness between 10 and 50 ShoreOOO, in particular between 10 and 30 ShoreOOO.
• the hardness is measured according to the ASTM-D2240 standard on a sample having a thickness of 10 mm, the sample consisting of crosslinked OCA (with UVA) after having been cast in a liquid manner in a hollow mould.
• said at least one viscoelastic OCA layer has an elongation at break between 200% and 1000%, in particular between 250% and 1000%, preferably between 300% and 1000%.
• the functional film comprises at least a first flexible transparent substrate, a first OCA layer and a second flexible transparent substrate, the first flexible transparent substrate and/or the second flexible transparent substrate having a technical function to provide the technical function to said functional film.
• the outermost flexible transparent substrates of the functional film are composed of a separate material from PVB (polyvinyl butyral) or EVA (ethylene-vinyl acetate).
• the functional film comprises a first flexible transparent substrate, a first OCA layer, a second flexible transparent substrate with a technical function, a second OCA layer and a third flexible transparent substrate.
• the first and/or the third flexible transparent substrate can have a technical function which will be distinct from that of the second flexible transparent substrate.
• a flexible transparent substrate of the functional film can be a solar control film (for example reflecting and/or absorbing infrared), a UV protection film, a film allowing the variation of the opacity, or even a film allowing the variation of the light transmittance.
• the functional film comprises a flexible transparent substrate with a technical function which is an infrared-reflecting film.
• the flexible transparent substrate with a technical function of the functional film is for example a film made of PET (polyethylene terephthalate), PC (polycarbonate), PI (polyimide), PU (polyurethane) or TAC (cellulose triacetate).
• PET polyethylene terephthalate
• PC polycarbonate
• PI polyimide
• PU polyurethane
• TAC cellulose triacetate
• the or one of the flexible transparent substrates with a technical function of the functional film is a liquid crystal cell.
• the liquid crystal cell forms a flexible film that can be manipulated in itself.
• the liquid crystal cell is intended to provide the glazing with a function of varying its light transmission.
• a glazing having to comprise a liquid crystal cell having to comprise a liquid crystal cell
• the fact of laminating a liquid crystal cell in the form of a flexible film comprising a liquid crystal cell and at least one layer made of OCA which is viscoelastic so as to be able to deform in thickness during the process of laminating the glazing minimizes the risk of visual defects in the glazing, such as folds or defects of inhomogeneity of light transmission.
• the presence of such a viscoelastic OCA has the advantage of greatly reducing the risk of propagation of cracks at the level of the electrodes of the liquid crystal cell during the use of the glazing which undergoes cycles of deformation due to the temperature variation cycles.
• the liquid crystal cell may be in the form of a so-called “host-guest” cell containing a mixture of a liquid solution and liquid crystals.
• the liquid solution containing liquid crystals is trapped in a cavity delimited by two encapsulation substrates and a peripheral sealing gasket.
• the two encapsulation substrates are made of flexible polymeric material.
• the liquid solution containing the liquid crystals can comprise one or more dichroic dyes.
• the liquid crystal cell comprising a mixture of a liquid solution and liquid crystals, in which one or more dichroic dyes are dispersed, is generally called a “host-guest” liquid crystal cell, or even a “guest- host” using the English expression.
• the guest-host liquid crystal cell may further comprise one or more polarizers (on one or the outer faces of the cell).
• the liquid crystal cell can be a polymeric dispersed liquid crystal system “PDLC” or a cholesteric liquid crystal system “CLC” or a liquid crystal system in polymer network “PNLC”. These cells are in the form of a flexible substrate.
• PDLC polymeric dispersed liquid crystal system
• CLC cholesteric liquid crystal system
• PNLC polymer network
• the OCA selected according to the invention is chosen from OCAs based on acrylic, polyvinyl acetate, polyurethane, silicone, and epoxy.
• the laminated glazing of the invention can be building glazing. It can be used in double glazing or in triple glazing.
• the laminated glazing of the invention can be vehicle glazing, in particular a vehicle glazing chosen from an automobile, a train, a truck, an aircraft, a bus, and a military vehicle.
• the laminated glazing may be curved.
• the invention also relates to a use of a functional film in the manufacture of laminated glazing, the functional film being sandwiched between two lamination inserts and two glass substrates, characterized in that the film functional (which is flexible) comprises at least one layer of a transparent adhesive material (OCA) which is viscoelastic so as to be capable of deforming in thickness during the process of laminating the glazing, in particular OCA having a hardness comprised between 10 and 50 ShoreOOO.
• OCA transparent adhesive material
• FIG. 1 represents a partial schematic view in side section of a laminated glazing according to the invention.
• FIG. 2 is a schematic sectional view of an embodiment of a functional film according to the invention intended to be integrated into the glazing of FIG. 1, the functional film comprising a single layer of OCA.
• FIG. 3 is a schematic sectional view of another embodiment of a functional film according to the invention comprising two layers of OCA arranged on either side of a flexible substrate with a technical function.
• FIG. 4 corresponds to FIG. 2 integrating a liquid crystal cell in the functional film.
• FIG. 5 or figure 5 illustrates a laminated glazing incorporating the functional film of figure 4.
• FIG. 6 corresponds to the embodiment of the functional film of FIG. 3 incorporating a liquid crystal cell.
• FIG. 7 or figure 7 illustrates an embodiment of laminated glazing incorporating the functional film of figure 6.
• FIG. 8 or figure 8 is a partial photo of a laminated glazing of the invention according to figure 5.
• FIG. 9 is a partial photo of a comparative laminated glazing comprising a functional film with a guest-host cell without OCA.
• the laminated glazing 1 of the invention illustrated in Figures 1 and 2 has at least one technical function which cannot be integrated into a usual laminating film of the PVB or EVA type. Said at least one technical function is integrated into a functional film 2 illustrated in FIGS. 2 and 3, which is multilayered and comprises according to the invention at least one OCA layer 20, the OCA also being viscoelastic so as to be able to deform in thickness during the glazing lamination process.
• the laminated glazing 1 can in particular be curved while minimizing, thanks to the functional film 2, optical defects such as creases at the edge of the glazing.
• the lamination films 3 and 4 and/or the glass substrates 10 and 11 can also have technical features such as ultraviolet cutoff, infrared protection, acoustic properties, antireflection, non-stick, anti-scratch, photocatalytic, anti-fingerprint, anti-fog, coloring.
• the laminated glazing 1 comprises at least a first glass substrate 10 and a second glass substrate 11 respectively constituting the outer substrates of the glazing, at least one functional film 2, and a first interlayer film of lamination 3 which secures the first glass substrate 10 to the functional film 2, and a second intermediate lamination film 4 which secures the second glass substrate 11 to the functional film 2.
• the glass substrates 10 and 11 have a thickness suitable for the use of laminated glazing.
• the thickness may be between 0.3 mm and 15 mm, preferably between 1 to 5 mm; it is for example 1.6 mm, 1.8 mm or 2.1 mm.
• the interlayer lamination films 3 and 4 have in particular a thickness of between 0.07 mm and 2 mm, in particular is 0.38 mm or 0.76 mm.
• the first and second interlayer lamination films 3 and 4 are for example made of PVB.
• the functional film 2 is a flexible film, which can be manipulated independently to be deposited on one of the interlayer lamination films 3 or 4 during the stacking of the various substrates and films for the manufacture of the glazing by the lamination process.
• the functional film 2 comprises at least a first OCA layer 20 sandwiched between a first flexible transparent substrate 21 and a second flexible transparent substrate 22, the first flexible transparent substrate and / or the second flexible transparent substrate having a technical function.
• the OCA is a prisoner in Functional Movie 2.
• the technical function is for example given to the second flexible substrate 22 which consists for example of an infrared-reflecting PET film or, as illustrated in Figures 4 to 7, be a liquid crystal cell for varying the light transmission of the laminated glazing 1.
• the functional film 2 may include a third flexible substrate 23 which is attached to the second flexible substrate 22 by arranging another layer of OCA 20 at the interface.
• the second and third flexible substrates 22 and 23 each have for example a technical function.
• the OCA layer 20 of the flexible functional film 2 is made of a transparent viscoelastic material so that during the glazing lamination process, the OCA layer 20 (captive in the functional film) is able to deform locally in thickness in the functional film during the lamination of the glass substrates 10 and 11 and of said functional film 2. Consequently, the OCA layer 20 is sufficiently elastic to deform during the autoclaving step and to absorb the relaxation stresses during cooling of the glazing. Thus, it results unexpectedly that the addition of this layer of OCA 20 in the stack of the laminated glazing 1 minimizes the visual defects on the glazing.
• the OCA layer 20 may be a transparent adhesive material which has been deposited by liquid means on the first flexible substrate 21 thus serving as a support, which has been encapsulated using the second flexible substrate 22 and which has been cross-linked, to form a sandwiched layer, which is viscoelastic.
• the OCA layer 20 can be a transparent material in the form of a polymerized or pre-polymerized film.
• PSA Pressure Sensitive Adhesive in English
• post-adhesive polymer film partially crosslinked before assembly - and which will be completely crosslinked after assembly.
• the PSA film is typically adhered to the flexible substrate 22 by contact and application of mechanical pressure.
• the post-adhesive film is typically brought into contact with the flexible substrate 22 before further crosslinking causing adhesion to the substrate.
• Further crosslinking is generally carried out by photo-crosslinking, in particular using UV irradiation.
• the assembled glazing is placed under vacuum for degassing, then put in an autoclave under pressure, positive pressure of 2 to 4 bars for example, and possibly at a temperature above: ambient temperature.
• the use of a post-adhesive film proves to be particularly advantageous for producing curved glazing.
• the hardness of the OCA 20 layer is between 10 and 50 ShoreOOO, in particular between 10 and 30 ShoreOOO.
• the thickness of the OCA layer 20 is typically greater than 0.5 ⁇ m, preferably comprised in a range of values from 0.5 mm to 2 mm.
• OCA is based on viscoelastic silicone.
• This OCA in viscoelastic silicone has a hardness between 10 and 30 ShoreOOO shore A.
• the layer of OCA in viscoelastic silicone has a thickness of 1 mm.
• the PSA film is preferably chosen from polymers based on acrylate, urethane acrylate or fluoro urethane acrylate or silicone.
• the post-adhesive film is preferably a photo-crosslinked post-adhesive film based on acrylate.
• the second flexible substrate 22 is a liquid crystal guest-host cell, for example commercial, the outer face of the guest-host cell forming the outer face functional flexible film 2.
• the third substrate 23 does not necessarily have a technical function but makes it possible to sandwich a liquid crystal guest-host cell 22 between two layers of OCA 20; this symmetrical stack with two layers of OCA on each side of the liquid crystal guest-host cell makes it possible, depending on the uses, to further minimize the risk of optical defects, in particular in reflection.
• the liquid crystal guest-host cell 22 comprises a mixture of a solution in liquid form 22A, liquid crystals and at least one dichroic dye, the mixture in liquid form being trapped between two encapsulation substrates in flexible material 22B and 22C, and a peripheral seal 22D.
• the two encapsulation substrates made of flexible material 22B and 22C are kept spaced apart by spacers, not shown, which are incorporated into the sealing joint 22D making it possible to delimit the sealed cavity receiving the liquid solution 22A with liquid crystals.
• the peripheral sealing joint 22D is for example made of epoxy resin or silicone.
• the inner surface facing the cavity of each of the two encapsulation substrates 22B and 22C is covered with an electrode, for example made of ITO, itself covered with an alignment layer, the alignment layers being in contact with the liquid solution 22A.
• the liquid crystal cell 2 has a total thickness of between 250 and 350 ⁇ m.
• the liquid crystal functional film 2 has for example a thickness of the order of 1.4 mm
• the laminated glazing 1 sees its light transmission modified when an electric voltage is applied to the electrodes of the liquid crystal cell 2.
• the two encapsulation substrates 22B and 22C of the liquid crystal cell (of the functional film) 2 are flexible. They may be of glass which is thin enough to provide the liquid crystal cell with flexibility.
• the glass encapsulation substrates 22B and 22C have for example a thickness of less than 1000 ⁇ m, in particular between 25 ⁇ m and 700 ⁇ m, preferably a thickness of less than 300 ⁇ m, or even less than 100 ⁇ m.
• the laminated glazing 1 of Figure 5 corresponds to the glazing of Figure 1 for which the functional flexible film 2 corresponds to that of Figure 4 in order to give the glazing a function of variable light transmission thanks to the crystal cell Iiquide22.
• the laminated glazing 1 of Figure 7 uses the functional film 2 of Figure 6 for a variable light transmission function through the Iiquide22 crystal cell which is sandwiched between two layers of OCA.
• the functional films 2 of the invention with a viscoelastic OCA is advantageously used in curved glazing.
• Laminated roof glazings which are curved have been manufactured and photographed at their edge: the photo of FIG. 8 is a laminated glazing 1 of the invention according to FIG.
• FIG. 9 is a laminated glazing using the same liquid crystal cell 22, but alone and directly laminated between two PVB interlayer films associated with the glass substrates.
• the laminated glazing of Figure 9 shows folds at the edge, while the laminated glazing of the invention visible in Figure 8 does not show any defect (the photo of Figure 8 shows the glazing with a moiré to the back of the glazing so as to be able to more easily visualize, in the event of visual defects, these defects).

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• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Nonlinear Science (AREA)
• Mathematical Physics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Joining Of Glass To Other Materials (AREA)
• Laminated Bodies (AREA)

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• 2021
  • 2021-07-19 FR FR2107778A patent/FR3125252B1/fr active Active
• 2022
  • 2022-07-18 CN CN202280005038.0A patent/CN115835961A/zh active Pending
  • 2022-07-18 WO PCT/FR2022/051423 patent/WO2023002111A1/fr active Application Filing
  • 2022-07-18 EP EP22754479.8A patent/EP4373670A1/de active Pending

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