Interlayers and encapsulation layers for use with holographic optical elements

Abstract

To provide interlayers that provide desirable optical properties when incorporated into laminates containing a holographic optical element(s) (HOEs), and that maintain and do not impair properties of the HOE film.SOLUTION: A manufacturing process comprises the steps of: providing a first polymer layer comprising a low refractive index compound and a polymeric volume hologram; combining the first polymer layer and the polymeric volume hologram to form a combined layer; providing at least a first substrate; and laminating the combined layer and the at least first substrate to form a laminated structure. The first substrate is adjacent to the first polymer layer. The laminated structure has partitioned low refractive index compound levels within the polymeric volume hologram such that the light modification properties of the polymeric volume hologram following lamination and equilibration of the low refractive index compound with the polymer interlayer are greater than 70% of the magnitude of the original light modification properties of the polymeric hologram prior to the combination in at least one wavelength range.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001]

[0001] The present invention relates generally to polymer interlayers used to encapsulate and protect holographic optical elements, and laminates including these interlayers. More particularly, the present invention relates generally to polymer interlayers and laminates including at least one layer including a polymer interlayer and a holographic optical element. [Background technology]

[0002]

[0002] Generally, multi-layered glass panels include an interlayer or multiple interlayers or a laminate composed of an interlayer sandwiched between two glass panes. In some applications, the laminate may include only one glass pane or other rigid substrate. Laminated multi-layered glass panels are commonly utilized in architectural window applications, transportation vehicles (including cars, trucks, trains, boats, and airplanes), and photovoltaic solar panels. Multi-layered glass panels used in the first two applications are commonly referred to as laminated safety glass. Typically, the primary function of the interlayer in laminated safety glass is to absorb energy resulting from an impact or force applied to the glass, to hold the glass layers together even when force is applied, and to prevent the glass from shattering into sharp shards in the event of glass breakage. In addition to these safety benefits, the interlayer can additionally impart a higher acoustic rating to the laminated glass, reduce UV and IR transmission, and / or improve the aesthetics of the associated window.

[0003]

[0003] Typically, interlayers intended for use in laminated glass applications are generally manufactured by blending a polymeric resin, such as poly(vinyl acetal), with one or more plasticizers and melt processing the mixture into an interlayer by any applicable process or method known to those skilled in the art. Once formed, these interlayers, or multilayer interlayers, are typically wound into rolls for storage prior to later use in multilayer glass panels.

[0004] Interlayers can be incorporated into multilayer glass panels using various techniques known in the art. For example, at least one interlayer can be placed between two substrates, and excess interlayer can be trimmed from the edges to create an assembly. It is not uncommon for multiple interlayers to be placed within or between two substrates, thereby creating a multilayer stack having an outer glass panel and multiple inner polymer interlayers. Once formed, these stacks are typically processed to remove most of the interfacial air by any applicable process or method known to those skilled in the art, such as by nip rollers, vacuum bags, vacuum rings, or another suitable degassing mechanism. Additionally, the interlayers can be partially pressed to the substrates by any method known to those skilled in the art. In the final step, the interfacial bond created during the degassing operation is typically made more permanent by a high-temperature and / or high-pressure lamination process, some of which are known to those skilled in the art, such as, but not limited to, autoclaving.

[0005]

[0005] Higher performance laminates, such as windshields, are emerging that require additional functionality, such as head-up displays (HUDs). Polymer layers must not interfere with the optical properties of the glass laminate in which they are incorporated. Additional materials are believed to provide the required additional functionality.

[0006] Recent developments in materials, machine tools, and patterning are enabling holography to move from novelty products to highly technological applications. One such potential application is the use of holography as an angle-selective reflective element to enable automotive HUD technology. The most common application of holography is the use of optical elements, or holographic optical elements (HOEs). Holography has been advancing increasingly rapidly over the last decade, with the use of holographic elements now being proposed for applications such as fixed displays, automotive HUD applications, and user head-mounted glasses / displays. In all of these cases, a rational device setup has been envisioned, along with an understanding of the type and pattern of holographic element structures needed to produce the desired optical effect. However, in most cases, these technologies are still in the early stages of scaling, and organizations are working to produce prototypes that meet fitness-for-use criteria.

[0007] One such example of an early-stage development effort is the use of holography in automotive head-up display applications. It has been proposed to use holographic technology using an HOE embedded in the windshield or windshield to reflect light from a dash-mounted projector. The embedded HOE is designed to reflect light from a very narrow set of angles while allowing light to pass from most other angles; the result is a windshield system that reflects incident light from an in-dash projector system while not blocking the passage of light from all other angles. This allows the driver to simultaneously see what is happening outside the vehicle and perceive the informational image projected from the dash as well.

[0008]

[0008] Early adopters in this field have successfully designed and manufactured prototype HOE films that can demonstrate the ability to both reflect incident light at targeted angles while maintaining the ability to transmit light at other angles through the film. However, maintaining the desired optical properties when incorporating these films into finished windshields presents significant challenges. Lamination of HOE films into final laminated glass constructions invariably results in unintended material changes that affect the quality and intensity of light reflected by the HOE. More specifically, many of the combinations of commercially available interlayers and HOE films result in deficiencies in processability and / or functionality.

[0009]

[0009] The majority of the above HOE failures can be linked to the materials and processes used to fabricate the final component, such as a windshield. Attempts to laminate HOEs directly to or together with traditional interlayer films, such as PVB and polyurethane (TPU) interlayers, result in significant reductions in the intensity of the reflective response, typically on the order of 50–90%, although other reductions are possible. Separating or protecting the HOE from the polymer interlayer by capping it with a rigid, permeable surface helps preserve the intensity of the response, but has associated costs and can also have the unintended consequence of causing wrinkling and mottling of the HOE film at a level that reduces the quality of the reflective response (changes in reflected magnitude). Lamination quality can also be degraded with the addition of a rigid polymer substrate cap layer, as evidenced by bake tests and / or visible air trapped around the outer edges of the HOE.

[0010]

[0010] Commercially available HOE films are constructed from a variety of materials. In most cases, these films include a specially formulated elastic photopolymer film coated on a rigid substrate. In the final reflective film, the HOE is patterned for the desired optical effect by using high-intensity light (such as one or multiple lasers) to drive chemical reactions that create carefully designed areas of low and high refractive index within the elastic photopolymer film. A low refractive index compound (LRIC) (or multiple LRICs) is also often incorporated into the photopolymer layer to increase the refractive index difference within the patterned structure, enhancing the intensity of the HOE response.

[0011] LRICs are typically short-chain molecules that are mobile in most polymer films and are typically at least partially miscible. Lamination of E to a polymer film lacking the LRIC typically creates a concentration gradient that drives these LRIC moieties into the laminated film, which typically results in an unacceptable reduction in HOE reflection intensity. The final concentration level in both the initial HOE and the adjacent encapsulation layer depends primarily on (1) the relative solubility of the LRIC in each layer and (2) the relative thickness of each layer. Temperature, degree of contact, and time may also play a role in determining the final concentration level.

[0012]

[0012] The incompatibility of LRICs in encapsulating films, such as PVB or TPU, typically used in glass lamination, results in a net migration of these LRICs out of the original HOE film and into adjacent films or layers. This loss reduces the refractive index gradient within the HOE film, resulting in lower reflection intensity. While capping the HOE film with a rigid crystal or highly aligned superstrate prevents LRIC migration and alleviates this problem, it has been shown that such capping often results in other problems, such as the cost and tendency of the HOE film to wrinkle and bubble, as previously described. There is a clear need for an HOE film encapsulation system that prevents wrinkling, bubble formation, and the unacceptable loss of LRICs from the HOE film.

[0013]

[0013] Therefore, there is a need for an interlayer for use as an encapsulating film in a laminate that can provide the desired performance expected from a conventional glass laminate, while at the same time minimizing cost and not compromising the optical and physical properties of the HOE (or HOE film) incorporated into the laminate. Summary of the Invention

[0014] The present invention generally relates to an interlayer that exhibits superior properties and provides desirable characteristics when incorporated into a laminate, such as a windshield, window, or other glazing, containing a holographic optical element (HOE). When used in a laminate in conjunction with an HOE film, the interlayer maintains and does not detract from the properties of the HOE film.

[0015]

[0015] Embodiments of the present invention are described herein with reference to the following figures: [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 shows a cross-sectional view of an embodiment of a glass laminate containing an HOE film encapsulated between two interlayers. [Figure 2]

[0017] FIG. 1 shows a cross-sectional view of another embodiment of a glass laminate containing an HOE film encapsulated between two interlayers with an adhesive or bonding layer between the HOE film and the interlayers. DETAILED DESCRIPTION OF THE INVENTION

[0017]

[0018] The present invention generally relates to interlayers that exhibit superior properties and provide desirable optical characteristics when incorporated into laminates, such as windshields, windows, or other glazings, containing holographic optical elements (HOEs). When used in a laminate in conjunction with an HOE film, the interlayers maintain and do not impair the properties of the HOE film. More specifically, the present invention generally relates to the use of polymer interlayers in laminates comprising a polymer interlayer containing an LRIC and at least one HOE film. The present invention additionally relates to multilayer interlayers or sheets comprising a polymer layer or interlayer and an HOE film, where the polymer layer and the HOE film are in direct contact and the multilayer interlayer can be incorporated into a laminate. As described in further detail below, the polymer layers and interlayers are formulated and selected so that they can be used with an HOE film to form a laminate having an HOE film also incorporated therein. The polymer layers and interlayers described herein can provide desirable properties to a laminate while maintaining the desired optical properties required for such a laminate.

[0018]

[0019] It has been discovered that the polymer layer and the intermediate layer can be successfully formulated with one or more LRICs, so that the HOE film can be combined with the intermediate layer such that the final distribution level maintains HOE effectiveness (i.e., the effectiveness and strength of the HOE are not significantly reduced). The LRIC(s) in the intermediate layer can be the same or different from the LRIC(s) in the HOE. Additionally, the chemical and physical properties of these intermediate layer films can be modified to further enhance properties.

[0019]

[0020] As used herein, the term "interlayer" refers to a single or multi-layer polymer sheet that may be suitable for use with at least one rigid substrate to form a multi-layer panel. The terms "single-sheet" and "monolithic" interlayer refer to an interlayer formed from one single sheet, while the terms "multi-layer" and "multi-layer" interlayer refer to an interlayer having two or more sheets coextruded, assembled, laminated, or otherwise combined with one another.

[0020]

[0021] The term "multilayer interlayer" refers to a polymer interlayer comprising at least two polymer layers. As discussed further below, the multiple layers may be separately extruded layers, coextruded layers, or any combination of separately extruded and coextruded layers. Thus, a multilayer interlayer may include, for example, two or more single-layer interlayers combined together (a "multilayer interlayer"); two or more layers coextruded together (a "coextruded interlayer"); two or more coextruded interlayers combined together; a combination of at least one single-layer interlayer and at least one coextruded interlayer; and a combination of at least one multilayer interlayer and at least one coextruded interlayer.

[0021]

[0022] As used herein, a holographic optical element (HOE) refers to a holographic configuration that includes at least one substrate, referred to as a holographic element substrate, and a holographic element or film, such as a volume hologram or polymer volume hologram. The terms holographic optical element and holographic element may be used interchangeably. An HOE film is a polymer film that uses holographic technology to change the way light travels through a medium, creating a typically translucent, mirror-like surface that reflects light at certain set angles and not at other angles.

[0022]

[0023] The intermediate layer may be used alone or in conjunction with another film, such as an HOE film, as an encapsulating layer that provides functional support, such as coating, adhesion, or protection, to the HOE film. More than one encapsulating layer and film may be used depending on the desired application and properties. For example, two intermediate layers may be used (on both sides) to encapsulate the HOE film. In embodiments, one intermediate layer may include an LRIC, while the second intermediate layer may be a conventional intermediate layer that does not include an LRIC. In other embodiments, both (or all) intermediate layers may include an LRIC.

[0023]

[0024] As described above, polymer layers or interlayers can be used to form multi-layer interlayers and laminates, such as windshields or other laminated glass panels, that are useful for many applications. In various embodiments, these polymer layers can be formed from thermoplastic resins such as ethylene vinyl acetate, thermoplastic polyurethanes, ionomers, poly(vinyl acetal), and mixtures thereof. Various configurations and types of polymer layers are described in detail below.

[0024]

[0025] The use of certain polymer layers in combination with HOEs can provide beneficial properties to glass laminates. When an HOE layer is included, depending on the layer and structure combination, plasticizers may partition or migrate into or out of the HOE layer, altering the layer thickness and properties of the HOE layer. Certain specially formulated types of interlayers may be preferred because they can alter the properties of the polymer layer. Plasticizer distribution can also change the properties of the polymer layer.

[0025]

[0026] Generally, the polymer layer can comprise at least 1, at least 2, at least 3, at least 4, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent of one or more thermoplastic resins, based on the total weight of the polymer layer. Additionally or alternatively, the polymer layer can comprise up to 99, 95, 90, 80, 70, 60, or 50 weight percent of one or more thermoplastic resins, based on the total weight of the polymer layer, although other amounts can be used as desired. The types of polymer layers and thermoplastic resins that can be used to prepare such layers are further described below.

[0026]

[0027] In various embodiments, the polymer layer and the HOE layer may be in direct contact with each other or may be indirectly adjacent to each other through another layer. In one or more embodiments, at least one polymer layer and at least one HOE layer are in direct contact with each other when forming an interlayer or laminate. In such embodiments, the polymer layer and the HOE layer are desirably bonded directly to each other, although an adhesive may be utilized to strengthen this bond. Generally, this bond may be formed when the layers are stacked against each other and the multilayer interlayer is heated above the glass transition temperatures of all layers. This may occur, for example, by stacking the layers against each other and using heat and / or pressure, or by co-extruding the layers, or a combination of both.

[0027]

[0028] In various embodiments, the layers or intermediate layers described herein may include at least two polymer layers (e.g., a single layer or coextruded multiple layers) disposed in direct contact with one another. When three or more layers are utilized in a multilayered intermediate layer, some layers may be referred to as skin layers, and one or more layers may be referred to as core layers. As used herein, "skin layer" generally refers to the outer layer of the intermediate layer, and "one or more core layers" generally refers to the inner layer or layers disposed between the skin layers. At least one surface of the core layer may be in direct contact with at least one surface of the skin layer, or may be in indirect contact with the skin layer through a tie layer, coating, or adhesive.

[0028]

[0029] Exemplary layer arrangements for multi-layer interlayer embodiments include: skin / core / skin, skin / core, skin / core / core / skin, and skin / core / core / core / skin, although other embodiments are possible as well, as known to those skilled in the art.

[0029]

[0030] Figure 1 depicts an exemplary laminate 10 including an HOE film layer 12 and two polymer layers 14, which form a multi-layer interlayer 16. As shown in Figure 1, the complete interlayer structure 16 is sandwiched between two rigid substrates 18, such as glass.

[0030]

[0031] The multilayer interlayers described herein can also have more than three layers (e.g., at least four, at least five, at least six, or up to ten or more individual layers). In various embodiments, the multilayer interlayer structures can contain two, three, four, or more polymer layers, two or more of which may be in direct contact with each other, with the HOE layer, or with other types of layers. The layers can have a variety of thicknesses, which are determined primarily by the type of interlayer or laminate in which the layer is being used, and can be any desired thickness.

[0031]

[0032] In various embodiments, the thickness or specification of any layer or intermediate layer may be adjusted to achieve the desired properties. And depending on the application, it can be at least about 0.5 mils, at least about 1, at least about 2, at least about 3, at least about 4, at least about 5, at least about 6, at least about 7, at least about 8, at least about 9, at least about 10, at least about 15, at least about 20, at least about 25, at least about 30, at least about 35, at least about 40, at least about 45, at least about 50, at least about 55, at least about 60 mils or more. In millimeters, the thickness of the polymer layer or intermediate layer can be at least about 0.025, at least about 0.05, at least about 0.075, at least about 0.10, at least about 0.125, at least about 0.150, at least about 0.175, at least about 0.20, at least about 0.225, at least about 0.25, at least about 0.38, at least about 0.51, at least about 0.64, at least about 0.76, at least about 0.89, at least about 1.02, at least about 1.15, at least about 1.28, at least about 1.52 mm or more.

[0032]

[0033] The polymer layers described herein can further include at least one plasticizer. Depending on the specific composition of the thermoplastic resin forming the polymer layer, the plasticizer can be present in an amount of at least 1 pound, at least 2 pounds, at least 3 pounds, at least 4 pounds, at least 5 pounds, at least 10 pounds, at least 15 pounds, at least 20 pounds, at least 25 pounds, at least 30 pounds, at least 35 pounds, at least 40 pounds, at least 45 pounds, at least 50 pounds, at least 55 pounds, at least 60 pounds, or more per 100 pounds of resin (phr). In embodiments, the amount of plasticizer can be 120 or less, 110 or less, 105 or less, 100 or less, 95 or less, 90 or less, 85 or less, 7 or less, 70 or less, 65 or less, 60 or less, 55 or less, 50 or less, 45 or less, or 40 phr or less, although other amounts may be used depending on the particular material and desired properties.

[0033]

[0034] In various embodiments, the intermediate layer can contain at least 2, at least 5, at least 8, at least 10, at least 13, at least 15, at least 18, or at least 20 weight percent or more of at least one plasticizer, based on the weight of the polymer layer. Additionally or alternatively, the polymer can contain up to 100, up to 80, up to 70, up to 60, up to 50, up to 40, up to 30, up to 25, or up to 20 weight percent of at least one plasticizer, based on the weight of the polymer layer.

[0034]

[0035] Useful low refractive index compounds or plasticizers for polymer layers include plasticizers that have a low refractive index and are compatible with other materials, such as those in the HOE film layer. While low refractive index compounds are often referred to herein as plasticizers, other compounds with a low refractive index that help adjust the refractive index but cannot be called "plasticizers" may also be used. Examples include, but are not limited to, LRICs such as fluorourethanes (or fluorinated urethanes) and fluorinated esters. Fluorurethanes can be obtained, for example, by reacting isocyanates with fluorinated alcohols. Examples of useful LRICs are described in U.S. Pat. No. 8,999,608. B2, the disclosure of which is incorporated herein by reference. In embodiments, the LRIC has a refractive index of less than about 1.45, or less than about 1.40, or less than about 1.35, or less than about 1.30, or less than about 1.25. In embodiments, an LRIC with as low a refractive index as possible is desired.

[0035]

[0036] In some embodiments, the polymer interlayer and the polymer volume hologram are similar in composition, such that the plasticizer distribution between the layers is similar and the amount of plasticizer in the polymer interlayer is within the range of −25 to +25 weight percent of the concentration of plasticizer in the polymer volume hologram. In embodiments, the polymer interlayer comprises a concentration of plasticizer within the range of −15 to +15 weight percent, or −10 to +10 weight percent, or −5 to +5 weight percent of the concentration of plasticizer in the original polymer volume hologram.

[0036] In other embodiments where the polymer interlayer and the polymer volume hologram have different physical properties such that the plasticizer distribution between the layers differs, the amount of plasticizer in the polymer interlayer may be less or more than the total amount of plasticizer in the original polymer volume hologram and should be determined through an understanding of the relative plasticizer distribution between the layers. In some embodiments, the amount of plasticizer in the polymer interlayer is at least 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or at least 90% by weight of the concentration of plasticizer in the polymer volume hologram. In other embodiments, the amount of plasticizer in the polymer interlayer is at least 101%, 110%, 120%, 130%, 140%, 150%, 200%, 300%, 400%, or at least 500% by weight or more of the concentration of plasticizer in the polymer volume hologram.

[0037]

[0037] In most embodiments, the polymer interlayer is formulated to minimize plasticizer incorporation so that the plasticizer level in the fully encapsulated polymer volume hologram is at least 70%, or at least 80%, or at least 90% of the starting level of plasticizer present in the original unlaminated or unencapsulated polymer volume hologram.

[0038] In embodiments, the polymer interlayer comprises a plasticizer or plasticizer blend selected to have a refractive index within −0.1 to +0.1 of the refractive index of the plasticizer or plasticizer blend in the original polymer volume hologram. In embodiments, the plasticizer or plasticizer blend is selected to have a refractive index within −0.05 to +0.05, or −0.02 to +0.02 of the refractive index of the plasticizer or plasticizer blend in the original polymer volume hologram.

[0039] Additional plasticizers may be used in the polymer layers, particularly those not adjacent to or in contact with the HOE in the layer, as long as the use of the plasticizer does not adversely affect the desired properties of the final part or cause the final properties of a laminate or other device incorporating the polymer layer and HOE to fall outside the desired performance range. The plasticizer may be any known in the art. The plasticizer may be either monomeric or polymeric in structure. In various embodiments, the plasticizer may be a compound having 30 or fewer, 25 or fewer, 20 or fewer, 15 or fewer, 12 or fewer, or 10 or fewer carbon atoms and a hydrocarbon segment of at least 6 carbon atoms. Suitable conventional plasticizers for use in these interlayers include, for example, esters of polybasic acids or polyhydric alcohols, among others. Suitable plasticizers include, for example, triethylene glycol di-(2-ethylhexanoate) ("3GEH"), triethylene glycol di-(2-ethylbutyrate), triethylene glycol diheptanoate, tetraethylene glycol diheptanoate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl sebacate, butyl ricinoleate, castor oil, dibutoxyethyl phthalate, diethyl phthalate, dibutyl phthalate, trioctyl phosphate, triethyl glycol ester of coconut oil fatty acid, phenyl ether of polyethylene oxide rosin derivative, oil-modified sebacic acid alkyd resin, tricresyl phosphate, and mixtures thereof. In certain embodiments, the plasticizer is 3GEH.

[0040] Additionally, other plasticizers, such as high refractive index plasticizers, may also be used, either alone or in combination with another plasticizer, particularly in layers not adjacent to or in contact with the HOE. As used herein, the term "high refractive index plasticizer" refers to a plasticizer having a refractive index of at least 1.460. High refractive index plasticizers refer to plasticizers having a refractive index of at least 1.460, at least 1.470, at least 1.480, at least 1.490, at least 1.500, at least 1.510, at least 1.520, and / or a refractive index of at most 1.600, at most 1.575, or at most 1.550, as measured above.

[0041]

[0041] When the resin layer or intermediate layer contains a high RI plasticizer, the plasticizer can be present alone in the layer or can be blended with one or more additional plasticizers. Examples of high refractive index plasticizer types or classes include, but are not limited to, polyadipates (RI of 1.460 to 1.485); epoxides such as epoxidized soybean oil (RI of 1.460 to 1.480); phthalates and terephthalates (RI of 1.480 to 1.540); benzoates and toluates (RI of 1.480 to 1.550); and other specialty plasticizers (RI of 1.490 to 1.520). Specific examples of suitable RI plasticizers are dipropylene glycol dibenzoate, tripropylene glycol dibenzoate, polypropylene glycol dibenzoate, isodecyl benzoate, 2-ethylhexyl benzoate, diethylene glycol benzoate, butoxyethyl benzoate, butoxyethyoxyethyl benzoate, butoxyethoxyethoxyethyl benzoate, propylene glycol dibenzoate, 2,2,4-trimethyl-1,3-pentanediol ... The high RI plasticizer may include, but is not limited to, dibenzoate isobutyrate, 1,3-butanediol dibenzoate, diethylene glycol di-o-toluate, triethylene glycol di-o-toluate, dipropylene glycol di-o-toluate, 1,2-octyl dibenzoate, tri-2-ethylhexyl trimellitate, di-2-ethylhexyl terephthalate, bis-phenol A bis(2-ethylhexanoate), di-(butoxyethyl) terephthalate, di-(butoxyethyoxyethyl) terephthalate, and mixtures thereof. In embodiments, the high RI plasticizer may be selected from dipropylene glycol dibenzoate and tripropylene glycol dibenzoate, and / or 2,2,4-trimethyl-1,3-pentanediol dibenzoate. In various embodiments, the plasticizer can be selected from at least one of the following: benzoates, phthalates, phosphates, arylene-bis(diarylphosphates), and isophthalates.

[0042] Other useful plasticizers include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, dibenzyl phthalate, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, triethyl citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl-tri-n-butyl citrate, and acetyl-tri-n-(2-ethylhexyl) citrate.

[0043] Mixtures of plasticizers may also be used. For example, a mixture of one or more LRICs with one or more conventional plasticizers may be used. Alternatively, two or more LRICs may be used alone or with other, non-conventional plasticizers.

[0044] The types of thermoplastic resins that can be used to form the layers are described in more detail below. EVA layer

[0045] In various embodiments, one or more of the polymer layers described herein may be ethylene. The film may comprise, consist essentially of, or consist of ethylene vinyl acetate ("EVA") resin. In such embodiments, the layer may also be referred to as an "EVA layer." These materials are commercially available, for example, as EVALAYER EV070C transparent EVA film (from Interlayer Solutions) and as VISTASOLAR® 520.68 film (from TPI All Seasons Co., LTD), as well as from other sources.

[0045]

[0046] In embodiments in which at least one layer comprises EVA, the layer may comprise at least one LRIC. The EVA layer may also optionally contain other plasticizers, depending on its properties and the other layers, if any. The amount of plasticizer, including any LRIC, may be in the same range as those previously disclosed.

[0046]

[0047] EVA with varying levels of vinyl acetate comonomer can be used depending on the desired properties. In certain embodiments, the EVA comprises a vinyl acetate content of at least 70, at least 80, or at least 90 and / or no more than 99, 98, or 95 weight percent. In other embodiments, the vinyl acetate content can be at least about 10, or at least about 15, or at least about 20, or at least about 25 or more and / or less than 70 weight percent, such as about 45 or less, about 40 or less, about 35 or less, or from about 20 to about 40 or from about 25 to about 35 weight percent, although various amounts may be used depending on the desired application and properties.

[0047]

[0048] In various embodiments, the EVA may include compounded EVA, which may, in embodiments, contain silane additives, peroxide additives, co-activators, UV blockers, and / or antioxidants. Alternatively, the EVA may include "uncompounded" EVA, which lacks one or more of the above-listed components contained in compounded EVA, such as peroxide additives (in which case the EVA is no longer heat-responsive). In various embodiments, the EVA may be maleated.

[0048]

[0049] EVA layers can be used alone or in conjunction with other polymer layers described herein to produce various types of multilayer interlayers, which may include other types of layers, including poly(vinyl acetal) layers, such as polyvinyl butyral ("PVB") layers. Exemplary multilayer interlayer embodiments include, but are not limited to: EVA / HOE / EVA, PVB / EVA / HOE / EVA / PVB, PVB / HOE / EVA, and PVB / HOE / EVA / PVB.

[0049]

[0050] Without wishing to be bound by theory, it is believed that the EVA layer can also function as a tie layer between the poly(vinyl acetal) layer and the HOE layer or film, strengthening the bond between these two layers. In such embodiments, the EVA layer can be at least partially interposed between the poly(vinyl acetal) layer and the HOE layer. In other embodiments, the EVA can be a separate layer rather than a tie layer.

[0050]

[0051] A multilayer interlayer containing an EVA layer and one or more other polymer layers can be manufactured using any method known in the art. For example, each layer can be formed separately using techniques known in the art and then laminated together. Alternatively, a multilayer interlayer containing an EVA layer and another polymer layer can be manufactured via coextrusion.

[0051]

[0052] Due to the crosslinking properties of EVA, it is generally desirable to avoid fully crosslinking the EVA when forming an EVA layer. Typically, partially crosslinked EVA can be further coextruded with other polymer layers to form a multilayer interlayer. Therefore, it may be desirable to utilize an extrusion temperature that does not fully crosslink the EVA. Thermoplastic polyurethane layer

[0053] In various embodiments, the polymer layers described herein can comprise, consist essentially of, or consist of thermoplastic polyurethane ("TPU") resin. In such embodiments, the polymer layers may also be referred to as "TPU layers." One example is product A4700NAT (available from Covestro LLC—Specialty Film (formerly Deerfield Urethane)). In various embodiments, the TPU can comprise an aliphatic isocyanate-polyether or polyester urethane. Additionally, in certain embodiments, the TPU can also include UV stabilizers and antioxidants, as well as other additives, to provide the TPU with additional stability when exposed to heat and UV light.

[0052]

[0054] In embodiments in which the polymer layer comprises a TPU, the layer may comprise at least one LRIC. The TPU layer may also optionally contain other plasticizers, depending on its properties and the other layers, if any. The amount of plasticizer, including any LRIC, may be in the same range as those previously disclosed.

[0053]

[0055] TPU layers can be used in conjunction with HOE layers and other polymer layers described herein to produce various types of multilayer interlayers, which may also include poly(vinyl acetal) or PVB layers. Exemplary multilayer interlayer embodiments include, but are not limited to: TPU / HOE / TPU, PVB / TPU / HOE / TPU / PVB, PVB / HOE / TPU, and PVB / HOE / TPU / PVB.

[0054]

[0056] Without wishing to be bound by theory, it is believed that the TPU layer can also function as a tie layer between the poly(vinyl acetal) layer and the film as well as other layers of various materials, such as an HOE, strengthening the bond between these two layers. In such embodiments, the TPU layer can be at least partially interposed between the poly(vinyl acetal) and the HOE layer or film. In other embodiments, the TPU can be a separate layer rather than a tie layer.

[0055]

[0057] The multi-layer interlayer containing the TPU layer and another polymer layer can be manufactured using any method known in the art. For example, each layer can be formed separately using techniques known in the art and then laminated together. Alternatively, the multi-layer interlayer containing the TPU layer and another polymer layer can be manufactured via coextrusion. Ionomer Layer

[0058] In various embodiments, the polymeric layers described herein can comprise, consist essentially of, or consist of ionomer resins. In such embodiments, the polymeric layers may also be referred to as "ionomer layers."

[0056]

[0059] Generally, ionomer resins can include partially neutralized acid-ethylene copolymers. Furthermore, ionomer resins can have, for example, 0.1 to 30 weight percent, 1 to 25 weight percent, or 5 to 20 weight percent acid functionality based on the total weight of the polymer. In one or more embodiments, the ionomer resins can have at least 0.1, at least 1, at least 5, at least 10, or at least 15 weight percent and / or no more than 30, no more than 25, or no more than 20 weight percent acid functionality from one or more acrylic acids. Such acrylic acids can include, for example, acrylic acid, maleic acid, maleic anhydride, methacrylic acid, itaconic acid, fumaric acid, monomethylmaleic acid, and mixtures thereof.

[0057]

[0060] Further, in various embodiments, the ethylene copolymer may be selected from the group consisting of acrylates, methacrylates, and combinations thereof. In such embodiments, the methacrylates may be selected from the group consisting of methyl acrylate, methyl methacrylate, butyl acrylate, Ionomer resins may include butyl methacrylate, glycidyl methacrylate, vinyl acetate, and mixtures thereof. Ionomer resins are further described in U.S. Patent Nos. 8,399,097 and 8,399,098, the disclosures of which are incorporated herein by reference in their entireties.

[0058]

[0061] In embodiments in which the polymer layer comprises an ionomer, the layer may comprise at least one LRIC. The ionomer layer may also optionally contain other plasticizers, depending on its properties and the other layers, if any. The amount of plasticizer, including any LRIC, may be in the same range as those previously disclosed.

[0059]

[0062] Ionomer layers can be used in conjunction with other polymer layers and HOE layers described herein to produce various types of multilayer interlayers, which may also include poly(vinyl acetal) layers. Exemplary multilayer interlayer embodiments include, but are not limited to: ionomer / HOE / ionomer, PVB / ionomer / HOE / ionomer / PVB, PVB / HOE / ionomer, and PVB / HOE / ionomer / PVB.

[0060]

[0063] A multi-layer interlayer containing an ionomer layer and another polymer layer can be manufactured using any method known in the art. For example, each layer can be formed separately using techniques known in the art and then laminated together. Alternatively, a multi-layer interlayer containing an ionomer layer and another polymer layer can be manufactured via coextrusion. Poly(vinyl acetal) layer

[0064] In various embodiments, the polymer layers described herein can comprise, consist essentially of, or consist of a poly(vinyl acetal) resin, such as polyvinyl butyral. Poly(vinyl acetal) layers can be used in conjunction with other polymer layers described herein to produce various types of multilayer interlayers. Exemplary multilayer interlayer embodiments include, but are not limited to: PVB / adhesive coating (or tie layer) / HOE / adhesive coating (or tie layer) / PVB, PVB / other polymer / HOE / other polymer / PVB, PVB / HOE / other polymer, PVB / HOE / PVB, and PVB / HOE / other polymer / PVB.

[0061]

[0065] Poly(vinyl acetal) resins are described, for example, in U.S. Pat. Nos. 2,282,057 and 2,282,026, as well as Wade, B. 2016, Vinyl Acetal Polymers, Encyclopedia of Polymer Science and Technology, pp. 1-22 (online, Copyright 2016 They can be prepared by acetalization of poly(vinyl alcohol) with one or more aldehydes in the presence of a catalyst according to known methods, such as those described in John Wiley & Sons, Inc.

[0062]

[0066] Poly(vinyl acetal) resins typically have residual hydroxyl content, ester content, and acetal content. As used herein, residual hydroxyl content (calculated as PVOH) refers to the weight percent of moieties with hydroxyl groups remaining on the polymer chain. For example, poly(vinyl acetal) can be produced by hydrolyzing poly(vinyl acetate) to PVOH and then reacting the PVOH with an aldehyde, such as butyraldehyde or propionaldehyde, preferably butyraldehyde, to produce a polymer with repeating vinyl butyral units. In the process of hydrolysis of poly(vinyl acetate), typically, not all of the acetate side groups are converted to hydroxyl groups. For example, reaction with butyraldehyde typically does not result in the conversion of all hydroxyl groups on the PVOH to acetal groups. Thus, any finished polyvinyl butyral typically contains esters as side groups on the polymer chain. Residual ester groups, such as acetate groups (as vinyl acetate groups), and residual hydroxyl groups (as vinyl hydroxyl groups), as well as acetal (e.g., butyral) groups (as vinyl acetal groups), will be present. As used herein, residual hydroxyl content is measured on a weight percent basis according to ASTM 1396.

[0063]

[0067] In various embodiments, the poly(vinyl acetal) resin comprises a polyvinyl butyral resin, also referred to interchangeably herein as "PVB." An example polyvinyl butyral structure is used to further illustrate how the weight percentages are based on the moieties attached to the associated pendant groups:

[0064] [ka]

[0065]

[0068] Considering polyvinyl butyral of the above structure, the butyral or acetal content is based on the weight percentage of units A in the polymer, the OH content is based on the weight percentage of units B (polyvinyl OH moieties or PVOH) in the polymer, and the acetate or ester content is based on the weight percentage of units C in the polymer.

[0066]

[0069] The hydroxyl group content of the poly(vinyl acetal) resin is not particularly limited, but suitable amounts are at least 6, at least 8, at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, or at least 17, in each case up to 35 weight percent or more of PVOH. In some embodiments, the poly(vinyl acetal) can have a residual hydroxyl content of less than 15 weight percent, or less than 14, less than 13, less than 12, less than 11, less than 10, less than 9, or less than 8 weight percent. Generally, poly(vinyl acetal) resins with a lower hydroxyl weight percentage are capable of absorbing more plasticizer and absorbing plasticizer more efficiently.

[0067]

[0070] The poly(vinyl acetal) resin may also contain no more than 20 weight percent, no more than 17 weight percent, no more than 15 weight percent, no more than 13 weight percent, no more than 11 weight percent, no more than 9 weight percent, no more than 7 weight percent, no more than 5 weight percent, or no more than 4 weight percent residual ester groups, calculated as polyvinyl esters such as, for example, acetate, with the remainder being acetals such as butyraldehyde acetal, optionally including small amounts of other acetal groups such as, for example, 2-ethylhexanal groups (see U.S. Pat. No. 5,137,954). As with the residual hydroxyl group measurement, the weight percent of residual ester groups (i.e., residual acetate content) is based on the portion of the polymer backbone that is bonded to acetate groups, including pendant acetate groups.

[0068]

[0071] The poly(vinyl acetal) resins used in the present invention may also have an acetal content of at least 50, at least 5, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, or at least 90 weight percent or more. Additionally or alternatively, the acetal content may be up to 94, up to 93, It can be up to 92, up to 91, up to 90, up to 89, up to 88, up to 86, up to 85, up to 84, up to 83, up to 82, up to 80, up to 78, up to 77, up to 75, up to 70, or up to 65 weight percent.

[0069]

[0072] The acetal groups in the poly(vinyl acetal) resin can include vinyl propynyl or vinyl butyral groups. In one or more embodiments, the acetal groups include vinyl propynyl groups. In some embodiments, the poly(vinyl acetal) resin can include any aldehyde residue, and in some embodiments, at least one C4-C8 aldehyde residue. Examples of suitable C4-C8 aldehydes can include, for example, n-butyraldehyde, i-butyraldehyde, 2-methylvaleraldehyde, n-hexylaldehyde, 2-ethylhexylaldehyde, n-octylaldehyde, and combinations thereof. One or more poly(vinyl acetal) resins utilized in the layers and interlayers described herein may comprise a residual content of at least one C4-C8 aldehyde of at least 20, at least 30, at least 40, at least 50, at least 60, or at least 70 weight percent or more, based on the total weight of the aldehyde residuals of the resin. Alternatively, or additionally, the poly(vinyl acetal) resin may comprise no more than 99, no more than 90, no more than 85, no more than 80, no more than 75, no more than 70, or no more than 65 weight percent of at least one C4-C8 aldehyde. The C4-C8 aldehyde may be selected from the group listed above or may be selected from the group consisting of n-butyraldehyde, i-butyraldehyde, 2-ethylhexylaldehyde, and combinations thereof.

[0070]

[0073] The weight average molecular weight of the poly(vinyl acetal) resin is not particularly limited. The poly(vinyl acetal) resin has a weight average molecular weight (M) of at least 20,000, at least 30,000, at least 40,000, at least 50,000, at least 60,000, or at least 70,000. w ), preferably substantially up to 300,000 daltons, although higher molecular weights may be used in some cases, with no particular upper limit, in each case as determined by size exclusion chromatography using the low angle laser light scattering (SEC / LALLS) method of Cotts and Ouano in tetrahydrofuran, as known to those skilled in the art.

[0071]

[0074] The multilayer interlayer containing the poly(vinyl acetal) layer and one or more other polymer layers can be manufactured using any method known in the art. For example, each layer can be formed separately using techniques known in the art and then laminated together. Alternatively, the multilayer interlayer containing the poly(vinyl acetal) layer and one or more other polymer layers can be manufactured via coextrusion.

[0072]

[0075] In various embodiments, the HOE layer can be used with other polymer layers, such as acoustically regulating interlayers. Polymers that exhibit one set of desirable properties, such as acoustically regulating performance, often lack other desirable properties, such as impact resistance or strength. Therefore, to achieve a desired combination of properties, multilayered interlayers can be fabricated containing a poly(vinyl acetal) layer that exhibits desirable acoustically regulating performance and one or more other polymer layers that provide impact strength and resistance. In one or more embodiments, the acoustically regulating interlayer can contain a poly(vinyl acetal) layer having a Tg of at least -30, at least -25, at least -20, at least -15, at least -10, at least -5, or at least 0°C and / or less than 40, 30, 25, 20, 15, 10, or 5°C.

[0073]

[0076] Additionally, in various embodiments, the poly(vinyl acetal) resin or poly(vinyl acetal) layer may exhibit enhanced acoustic tuning properties, such as improved loss tangent, as compared to, for example, a comparable poly(vinyl n-butyral) resin layer. Loss tangent is the ratio of the loss modulus (G") in Pascals to the storage modulus (G') in Pascals of a specimen, as measured by Dynamic Modulus Analysis (DMTA). DMTA is performed in shear mode using a vibration frequency of 1 Hz and a temperature sweep rate of 3°C / min. The peak value of the G" / G' curve at the glass transition temperature is the loss tangent. A higher loss tangent indicates higher damping, which can be interpreted as better sound deadening properties or acoustic conditioning performance.

[0074]

[0077] Furthermore, in various embodiments, the poly(vinyl acetal) resin or poly(vinyl acetal) layer can exhibit a damping loss factor, or loss factor, of at least 0.10, at least 0.15, at least 0.17, at least 0.20, at least 0.25, at least 0.27, at least 0.30, at least 0.33, or at least 0.35. The loss factor is measured by the mechanical impedance measurement method described in ISO standard 16940. To measure the loss factor, a polymer sample is laminated between two sheets of clear glass, each 2.3 mm thick, and fabricated to have a width of 25 mm and a length of 300 mm. The laminated sample is then excited at its midpoint using a commercially available vibrator from Bruel and Kjar (Narum, The Netherlands), and an impedance head is used to measure the force and vibration velocity required to excite the bar into vibration. The resulting transfer function is recorded on a National Instrument data acquisition and analysis system, and the loss factor in the first vibration mode is calculated using the half-width method.

[0075]

[0078] According to some embodiments, the poly(vinyl acetal) resin or poly(vinyl acetal) layer may exhibit desirable acoustic conditioning properties, as reflected, for example, by a reduction in sound transmission through the interlayer (i.e., sound transmission loss). In some embodiments, the acoustic conditioning interlayer may exhibit a sound transmission loss at a coincidence frequency of at least 34, at least 34.5, at least 35, at least 35.5, at least 36, at least 36.5, or at least 37 dB, measured according to ASTM E90 at 20° C. During such sound transmission testing, the interlayer is laminated between two sheets of 2.3 mm clear glass, and the test is performed at a reference frequency of 3,150 Hz. bonding layer

[0079] In various embodiments, one or more of the polymer layers described herein may be a tie layer. As used herein, "tie layer" refers to a layer or sheet in an interlayer that bonds at least two other layers together. The tie layer may comprise, consist essentially of, or consist of a thermoplastic resin selected from the group consisting of EVA, TPU, ionomer, polyvinyl acetate, mixed polyvinyl esters, ethylene vinyl alcohol, and combinations thereof. In other embodiments, the tie layer may comprise other materials known in the art.

[0076]

[0080] In embodiments in which the polymer layer includes a tie layer, the layer may include at least one LRIC. The tie layer may also optionally contain other plasticizers, depending on its properties and the other layers, if any. The amount of plasticizer may be in the same range as those previously disclosed, including any LRIC. Those skilled in the art will understand that in systems in which an interlayer and tie layer are used, the total amount of LRIC incorporated into each layer prior to lamination is not critical, so long as the final equilibrium level in the patterned HOE film laminated into the structure after distribution between the interlayer, tie layer, and HOE film layer exceeds the levels previously described. By way of example, it is possible to formulate the tie layer without an LRIC and the interlayer with sufficient LRIC for proper equilibration in both the tie layer and the patterned photopolymer. It is also possible to formulate the interlayer without an LRIC and the tie layer with sufficient LRIC for proper equilibration in both the tie layer and the patterned photopolymer. In other cases, it is possible to formulate both the tie layer and the intermediate layer with equal amounts of LRIC, as long as there is proper balance in both the tie layer and the patterned photopolymer. It is possible to formulate both the tie layer and the intermediate layer with different amounts of LRIC.

[0077]

[0081] Tie layers can be used in conjunction with the HOE and other polymer layers described herein to enhance the bond between the HOE layer and various other layers in multilayer interlayers, particularly poly(vinyl acetal) or PVB layers. An exemplary multilayer interlayer configuration containing a tie layer includes PVB / tie layer / HOE layer / tie layer / PVB. In such embodiments, the tie layer can be at least partially interposed and / or positioned between the poly(vinyl acetal) layer and the HOE layer.

[0078]

[0082] 2 depicts an exemplary laminate 10 including an HOE layer 12, two polymer layers 14, and two tie layers 20, which form a multi-layer interlayer 16. As shown in FIG. 2, the interlayer 16 is sandwiched between two rigid substrates 18, such as glass.

[0079]

[0083] The multilayer interlayer containing the tie layer and the HOE layer can be manufactured using any method known in the art. For example, each layer can be formed separately using techniques known in the art and then laminated together. Alternatively, the multilayer interlayer containing the tie layer and the HOE layer can also be manufactured using any suitable method, including, for example, extrusion coating, dip coating, solution coating, blade coating, puddle coating, air-knife coating, printing, powder coating, spray coating, and combinations thereof.

[0080]

[0084] Adhesive coatings can be used in conjunction with the HOE layers described herein to enhance the bond between the HOE layer and various other layers in a multi-layer interlayer, if desired. In such embodiments, the adhesive coating can be at least partially interposed and / or positioned between the interlayer and the HOE layer. Method for manufacturing an intermediate layer

[0085] Interlayers according to various embodiments of the present invention can be made by any suitable process known to those skilled in the art for manufacturing interlayers, without limitation to the manufacturing method. For example, it is contemplated that a layer or interlayer can be formed by extrusion or coextrusion. In an extrusion process, one or more thermoplastic resins, a plasticizer, and optionally one or more additives described above can be premixed and fed into an extrusion device. The extrusion device is configured to impart a specific shape to the thermoplastic composition to create an extruded sheet. The extruded sheet at an elevated temperature can then be cooled to form a polymer sheet. Once the sheet is cooled and set, it can be cut and rolled for subsequent storage, transportation, and / or use as an interlayer.

[0081]

[0086] Coextrusion is a process in which multiple layers of polymeric materials are extruded simultaneously. Typically, this type of extrusion utilizes two or more extruders to melt and deliver a steady volumetric throughput of various thermoplastic melts of different viscosities or other properties through a coextrusion die to a desired final form. The thickness of the multiple polymer layers exiting the extrusion die in a coextrusion process can generally be controlled by adjusting the relative speeds of the melts through the extrusion die and by the size of the individual extruders processing each molten thermoplastic material.

[0082]

[0087] The extrusion process can occur at temperatures known to those skilled in the art, depending on the material and application. The layers and interlayers described herein can be manufactured based on any suitable method. The resulting resin composition can be formed into a sheet or layer based on any suitable method, including, but not limited to, solution casting, compression molding, injection molding, melt extrusion, melt blowing, and combinations thereof. When the interlayer is a multilayer interlayer comprising two or more layers or sheets, such a multilayer interlayer can also be manufactured based on any suitable method, including, for example, coextrusion, blown film, melt blowing, dip coating, solution coating, blade, paddle, air-knife, printing, powder coating, spray coating, and combinations thereof. do.

[0083]

[0088] Alternatively, each layer of the interlayer may be separately formed or extruded into a sheet, the sheets stacked to form a laminate structure in the desired order, and then compressed under heat and pressure to form the multi-layer interlayer. In various embodiments of the present invention, the layers or interlayers may be formed by extrusion or coextrusion. In an extrusion process, one or more thermoplastic polymers, a plasticizer, and optionally at least one additive may be premixed and fed into an extrusion apparatus, and the layer or interlayer may be melted and extruded through a die, thereby providing an extruded sheet. Alternatively, one or more layers may be purchased or manufactured separately using processes known in the art.

[0084]

[0089] Other additives may be incorporated into any one of the above layers used to form the laminate or interlayer to improve the performance of the final product or to impart certain additional properties to the interlayer. Such additives include, but are not limited to, adhesion modifiers, antiblocking agents, dyes, pigments, stabilizers (e.g., UV stabilizers), antioxidants, flame retardants, IR absorbers or blockers (e.g., indium tin oxide, antimony tin oxide, lanthanum hexaboride (LaB6), and cesium tungsten oxide), processing aids, flow additives, lubricants, impact modifiers, nucleating agents, heat stabilizers, UV absorbers, dispersants, surfactants, chelating agents, coupling agents, adhesives, primers, reinforcing additives, and fillers, among other additives known to those skilled in the art.

[0085]

[0090] Additives in liquid, powder, or pellet form are often used and can be mixed into the thermoplastic resin or plasticizer before it reaches the extruder unit or in combination with the thermoplastic resin in the extruder unit. These additives are incorporated into the composition and the resulting interlayer to enhance certain properties of the interlayer and its performance in multilayer glass panel products. Laminate including HOE layer

[0091] The interlayers described above may have improved properties and be useful with certain films, such as HOE films. Layers and interlayers containing at least one LRIC may be combined with HOE films through processes known in the art, such as encapsulation. In embodiments, an HOE film may have a layer or interlayer containing at least one LRIC on one side (such as the HOE side of the HOE film) or on both sides. In other embodiments, an HOE film may have a layer or interlayer containing at least one LRIC on the HOE side of the HOE film and another layer or interlayer on the substrate side of the HOE film. Interlayer Properties and End Uses

[0092] The interlayers can be used in many applications, such as laminates or panels containing one or more rigid substrates. Panels made with the interlayers described herein, such as glass panels containing an interlayer laminated between two glass substrates, can have good optical clarity. The transparency of an interlayer laminated between glass substrates can be determined by measuring the haze value, which is a quantification of the light not transmitted through a sheet glass panel containing a multilayer interlayer. Percent haze can be measured according to the following technique: An instrument for measuring haze, the Haze Meter, Model D25, is available from Hunter Associates (Reston, Va.), and can be used in accordance with ASTM D1003-61 (reapproved in 1977) - Procedure A, using Illuminant C at a 2-degree observation angle. In various embodiments, such as front glass, the interlayers described herein may exhibit a haze of less than 10, less than 9, less than 8, less than 7, less than 6, less than 5, less than 4, less than 3, less than 2, less than 1.5, less than 1, less than 0.75, or less than 0.5 percent, as measured in accordance with ASTM D1003-61. In other embodiments, optical properties may be less important, or higher haze levels may be desirable or acceptable where lower clarity is desired.

[0086]

[0093] Another parameter used to determine optical performance is transparency, or percent luminous transmittance (%T vis) and is measured using a spectrophotometer such as a HunterLab UltraScan XE in accordance with ASTM D1003, Procedure B, using Illuminant C at a 2° observation angle. The values ​​provided herein were obtained by analyzing a polymer sample laminated between two sheets of clear glass (commercially available from Pittsburgh Glass Works, Pennsylvania), each having a thickness of 2.3 mm. In some embodiments where high luminous transmittance is desired, the resin compositions, layers, and interlayers of the present invention may have a percent luminous transmittance of at least 50, at least 70, at least 80, at least 81, at least 82, at least 83, at least 84, at least 85, at least 85.5, at least 86, at least 86.5, at least 87, at least 87.5, at least 88, or at least 90 percent or more. For applications where a lower luminous transmittance is desired, the percent luminous transmittance may be less than 50 percent.

[0087]

[0094] Yellowness Index ("YI") is another measure of optical quality. The Yellowness Index of a polymer sheet is measured from spectrophotometric light transmittance in the visible spectrum by laminating (and autoclaving) a 30 gauge (30 mil or 0.76 mm) sheet sample between two sheets of 2.3 mm clear glass using a HunterLab UltraScan XE, in accordance with ASTM method E313 (formerly D-1925) (Illuminant C, 2° observation angle). In various embodiments, the interlayer may exhibit a Yellowness Index of less than 20, less than 18, less than 16, less than 14, less than 12, less than 10, less than 8, less than 6, less than 5, less than 4, less than 3, less than 2, less than 1.5, less than 1.0, less than 0.75, less than 0.5, less than 0.4, or less than 0.3, in accordance with ASTM E313.

[0088]

[0095] Interlayers according to embodiments of the present invention may be utilized in multilayer panels or laminates that include at least one substrate, such as a rigid substrate. As used herein, "rigid" generally refers to a relative term relative to other layers. Any suitable rigid substrate may be used, and in some embodiments, may be selected from the group consisting of glass, polycarbonate, biaxially oriented PET, copolyester, acrylic, polyamide, cellulose triacetate, and combinations thereof. When the rigid substrate comprises a polymeric material, the polymeric material may or may not include a hardcoat surface layer. In some embodiments, a multilayer panel or laminate includes a pair of rigid substrates with a resin interlayer disposed therebetween. In other embodiments, a multilayer panel includes a rigid substrate and an interlayer that includes an HOE layer therebetween, optionally including a tie layer, adhesive coating, and / or adhesion promoter, if desired.

[0089]

[0096] In various embodiments, the interlayers of the present invention are most commonly utilized in multilayer panels that typically include two substrates, such as a pair of glass substrates, with the interlayer disposed between the two substrates. An example of such a construction is: glass / interlayer / glass, where the interlayer may include any of the interlayers described above, including an HOE. These examples of multilayer panels are not intended to be limiting in any way, as one skilled in the art will readily recognize that numerous constructions other than those described above can be made using the interlayers of the present invention.

[0090]

[0097] The interlayers described herein can be laminated between glasses using techniques known in the art. A typical glass lamination process involves the following steps: (1) assembling two substrates (e.g., glass) and an interlayer; (2) briefly heating the assembly via IR radiation or convection; (3) passing the assembly through pressure nip rolls for a first degassing step; (4) heating the assembly a second time to a suitable temperature, such as about 50°C to about 120°C, to create a temporary bond to the assembly sufficient to seal the edges of the interlayer; and (5) passing the assembly through a second pressure nip roll to further seal the edges of the interlayer. (5) autoclaving the assembly to allow for further processing; and (6) autoclaving the assembly at an appropriate temperature and pressure, such as a temperature between 80 and 150°C and a pressure between 15 and 200 psig, for approximately 30 to 90 minutes. Other commercially practiced means known in the art for use in degassing the interlayer-glass interface (steps 2-5) include vacuum bag and vacuum ring processes, in which a vacuum is applied to remove air. An alternative lamination process involves the use of a vacuum laminator that first degasses the assembly and then completes the lamination at a sufficiently high temperature and vacuum.

[0091]

[0098] The various embodiments of the present invention described above should be used only as examples and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments set forth above can be easily made by those skilled in the art without departing from the spirit of the present invention. The present invention can be further illustrated by the following examples of embodiments thereof, but it will be understood that these examples are included solely for illustrative purposes and are not intended to limit the scope of the present invention unless specifically stated otherwise. [Example]

[0092]

[0099] Interlayer films and laminates having the configurations described and illustrated below can be produced by layering separate films (of different materials, such as PVB, TPU, EVA, ionomers, and others, with varying thicknesses and different plasticizer types and amounts) with an HOE film. Films or layers can also be layered or constructed via hand-molding techniques to form multilayer interlayers, such as HOEs encapsulated by one or more polymer layers. The HOE film or layer can be any desired HOE film, such as those previously described. The formed interlayer can then be laminated between two annealed glass sheets, such as glass sheets each 2.3 mm thick. The lamination process utilized a typical vacuum bag degassing followed by autoclaving to laminate all samples, including: (1) assembling the substrate, interlayer, and HOE film in a predetermined order and placing them in a vacuum bag; (2) vacuuming at room temperature for 20 minutes followed by an additional 60 minutes at 105°C; and (3) removing the sample from the vacuum bag and autoclaving at fixed conditions of 125°C and 13 bar for 40 minutes. As further described below, multiple samples can be fabricated using this lamination technique. Control example

[0100] The laminate with the configuration of glass / PVB / HOE / PVB / glass was 27.5 The HOE layer can be fabricated using two layers of 0.38 mm PVB formulated with weight percent 3GEH plasticizer (38 phr loading) (and a standard additive package), and the HOE layer is encapsulated between the two PVB layers. The laminate stack is then laminated using a vacuum bag degassing process followed by a standard autoclave lamination process known in the art. The completed construction contains a working volume hologram with a peak reflection near the originally programmed wavelength. The signal intensity of the hologram is reduced due to the reduced concentration of LRIC plasticizer in the HOE layer after redistribution through the full thickness of the volume hologram layer and the PVB layer encapsulating the holographic element or volume hologram.

[0093] Example 1

[0101] The laminate having a structure of glass / PVB / HOE / PVB / glass was 20 wt. The HOE layer can be fabricated using two layers of 0.38 mm PVB formulated with 100% 3GEH plasticizer (25 phr added) (and a standard additive package), and the HOE layer is encapsulated between the two PVB layers. The laminate stack is then laminated using a vacuum bag degassing process followed by a standard autoclave lamination process known in the art. The completed construction contains a working volume hologram with a peak reflection near the originally programmed wavelength. The signal intensity of the hologram is measured by measuring the volume hologram layer and the holographic element. This is due to the reduced concentration of LRIC plasticizer in the HOE layer after redistribution through its entire thickness with the PVB layer encapsulating the electron or volume hologram.

[0094] Example 2

[0102] The laminated body having a structure of glass / TPU / HOE / TPU / glass is LRIC This can be fabricated using two 0.5mm layers of plasticizer-free TPU and an HOE layer, encapsulating the HOE layer between the two TPU layers. The laminate stack is then laminated using a vacuum bag degassing process followed by a standard autoclave lamination process known in the art. The completed construction contains an actuated volume hologram with a peak reflection near the originally programmed wavelength. The signal intensity of the hologram is reduced due to the reduced concentration of the LRIC plasticizer originally contained in the HOE layer after redistribution across the entire thickness of the volume hologram layer and the TPU layer encapsulating the holographic element or volume hologram.

[0095] Example 3

[0103] The laminate having a structure of glass / PVB / HOE / PVB / glass was 20 wt. A volume hologram can be fabricated using two layers of 0.38 mm PVB formulated with 100% bis(2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl)(2,2,4-trimethylhexane-1,6-diyl)biscarbamate (a fluorinated LRIC plasticizer), and an HOE layer, encapsulated between the two PVB layers. The laminate stack is then laminated using a vacuum bag degassing process, followed by a standard autoclave lamination process known in the art. The completed configuration contains a working volume hologram with a peak reflection near the originally programmed wavelength. The signal intensity of the hologram is slightly reduced due to the reduced concentration of the LRIC plasticizer in the HOE layer after redistribution through the full thickness of the volume hologram layer and the PVB layer encapsulating the holographic element or volume hologram.

[0096] Example 4

[0104] The laminate having the structure of glass / PVB / HOE / PVB / glass was 10 wt. The HOE layer can be fabricated using two layers of 0.38 mm PVB formulated with 10% 3GEH and 10% by weight of a fluorinated LRIC plasticizer, and the HOE layer is encapsulated between the two PVB layers. The laminate stack is then laminated using a vacuum bag degassing process followed by a standard autoclave lamination process known in the art. The completed configuration contains a working volume hologram with a peak reflection near the originally programmed wavelength. The hologram signal intensity is at or near the originally programmed intensity.

[0097] Example 5

[0105] The laminate having a structure of glass / TPU / HOE / TPU / glass was 20 wt. The HOE layer can be fabricated using two layers of 0.5 mm TPU formulated with a fluorinated LRIC plasticizer (100%) and an HOE layer, encapsulated between the two TPU layers. The laminate stack is then laminated using a vacuum bag degassing process followed by a standard autoclave lamination process known in the art. The completed construction contains a working volume hologram with a peak reflection near the originally programmed wavelength. The hologram signal intensity is at or near the originally programmed intensity.

[0098] Example 6

[0106] A laminate having a structure of glass / 3-layer PVB / HOE / 3-layer PVB / glass is An acoustically controlled tri-layer midlayer can be fabricated using two tri-layers of 0.38 mm PVB compounded with 27.5 weight percent 3GEH plasticizer (38 phr loading) in the skin layers, and an HOE layer, with the HOE layer encapsulated between two tri-layers of PVB. The laminate stack is laminated using a pressure bag degassing process followed by a standard autoclave lamination process known in the art. The completed configuration contains a working volume hologram with a peak reflection close to the originally programmed wavelength. The hologram signal intensity is slightly reduced due to a reduced concentration of the LRIC plasticizer in the HOE layer after redistribution through the full thickness of the volume hologram layer and the PVB layer encapsulating the holographic element or volume hologram.

[0099] Example 7

[0107] The laminate with the structure of glass / PVB / HOE / PVB / glass is wedge-shaped. This can be fabricated using two layers of 0.38 mm PVB formulated with 27.5 weight percent 3GEH plasticizer (38 phr loading) in a three-layer acoustically regulated skin layer incorporating ITO absorbers for solar control, and an HOE layer, encapsulated between the two PVB layers. The laminate stack is then laminated using a vacuum bag degassing process followed by a standard autoclave lamination process known in the art. The completed construction contains a working volume hologram with a peak reflection near the originally programmed wavelength. The signal intensity of the hologram is slightly reduced due to the reduced concentration of the LRIC plasticizer in the HOE layer after redistribution through the full thickness of the volume hologram layer and the PVB layer encapsulating the holographic element or volume hologram.

[0100] Example 8

[0108] A laminate having a structure of glass / 3-layer PVB / HOE / 3-layer PVB / glass is It can be fabricated using two 0.38 mm PVB trilayers formulated with 10 weight percent 3GEH and 10 weight percent fluorinated LRIC plasticizer in the three skin layers, and an HOE layer, encapsulated between the two PVB trilayers. The laminate stack is then laminated using a vacuum bag degassing process followed by a standard autoclave lamination process known in the art. The completed construction contains a working volume hologram with a peak reflection near the originally programmed wavelength. The hologram signal intensity is at or near the originally programmed intensity.

[0101] Example 9

[0109] The laminate with the structure of glass / PVB / HOE / PVB / glass is wedge-shaped. The HOE layer can be fabricated using two layers of 0.38 mm PVB formulated with 10 weight percent 3GEH and 10 weight percent fluorinated LRIC plasticizer in a three-layer acoustically regulated skin layer incorporating ITO absorbers for solar control, and the HOE layer is encapsulated between the two PVB layers. The laminate stack is then laminated using a vacuum bag degassing process followed by a standard autoclave lamination process known in the art. The completed construction contains a working volume hologram with a peak reflection near the originally programmed wavelength. The hologram signal intensity is at or near the originally programmed intensity.

[0102] Example 10

[0110] The laminate with the configuration Glass / HOE / PVB / Glass contains 10% by weight The HOE layer can be fabricated using one layer of 0.38 mm PVB formulated with 3GEH and 10 weight percent fluorinated LRIC plasticizer, and the HOE layer is applied or coated directly to the glass and laminated to the PVB without a rigid polymer carrier film. The laminate stack is then laminated using a vacuum bag degassing process followed by a standard autoclave lamination process known in the art. The completed construction contains a working volume hologram with a peak reflection near the originally programmed wavelength. The signal intensity of the hologram is a function of the concentration of the LRIC plasticizer in the HOE layer after redistribution through the full thickness of the volume hologram layer and the PVB layer encapsulating the holographic element or volume hologram. The difference is slightly reduced due to the decrease in the intensity.

[0103]

[0111] The optical properties of the laminate were compared with the initial HOE film reflectance and the laminate under the same conditions. The resulting configuration can then be measured and the reflection intensity determined, as determined by comparing the resulting digital image with the reflection. Table 1 shows various possible configurations and the signal intensities obtained after lamination.

[0104] [Table 1]

[0105]

[0112] The above results demonstrate that signal strength can be enhanced by incorporating LRIC plasticizers into the polymer interlayer. When using a blend of LRIC and a conventional plasticizer, the signal strength is slightly reduced, but is still better than laminates using only a conventional plasticizer such as 3GEH, or no plasticizer (e.g., with a TPU interlayer).

[0106]

[0113] Constructions made with interlayers that do not contain fluorinated LRICs generally have a low yield. They exhibit significantly lower holographic efficiency, observed through a significant reduction in reflected signal intensity. Incorporation of LRICs, such as fluorinated LRICs, into a polymer layer, such as PVB, generally allows for signal intensity to be maintained. This effect is achieved by incorporating enough fluorinated LRICs into the interlayer to prevent a concentration gradient that would otherwise result in migration of fluorinated LRICs out of the original HOE film or layer. This effect also occurs for LRICs of different chemical compositions. As long as the concentration level in the interlayer is designed in a way that prevents diffusion of LRICs from the HOE film into the interlayer, the refractive index target for the HOE can be maintained.

[0107]

[0114] Formulation changes result in improved encapsulation of the HOE layer and post-lamination results It is also possible to achieve this. Example 1 highlights the extent to which constructions using low levels of 3GEH plasticizer can result in reduced HOE signal intensity loss. Compare Example 1 with the control. Modifications to the PVB chemistry can also result in similar improvements. However, for many polymer interlayers, formulation changes, while they can help improve distribution, are doubtful of completely preventing LRIC loss from the HOE to the non-LRIC-containing interlayer. However, improvements to the interlayer formulation, through changes in plasticizer type and content, as shown in Example 4, have been found to be particularly effective when combined with the addition of LRIC.

[0108]

[0115] The LRICs present in the polymer interlayer and the HOE film are chemically similar. It is also expected that similar improvements can be achieved by compounding the intermediate layer with LRICs other than those used in the examples, as long as they have similar refractive indices. LRICs with different chemical structures can be used to achieve the same effect, but they must be carefully selected to achieve a distribution ratio that maintains the desired lattice spacing and refractive index within the HOE film.

[0109]

[0116] Some HOE films are produced without the use of LRIC, but instead with polymer The holographic effect achieved depends on the refractive index of the grating. In such cases, an intermediate layer with LRIC can be used to provide a refractive index modifier to such an HOE film, increasing the refractive index difference between the grating phases. Such an approach increases the effectiveness of the hologram overall.

[0110]

[0117] These LRICs are incorporated into the HOE film during lamination (i.e., LR It is also possible to simplify the HOE film fabrication process by designing a holographic photopolymer film without an LRIC, understanding that ICs migrate from the interlayer to the HOE film once laminated. This effectively makes the interlayer the LRIC delivery system. In such cases, it is expected that the initial HOE pattern must be modified to produce stripes with initial dimensions designed to change to the desired level following LRIC equilibration after lamination. definition

[0118] It is understood that the following is not intended to be an exclusive list of defined terms. Other definitions may be given in the above description, for example, with use of the defined terms in context.

[0111]

[0119] As used herein, the terms "a," "an," and "the" refer to one means one or more.

[0120] As used herein, the term "and / or" refers to a list of two or more items. When used in a list, it means that any one of the listed items can be utilized alone, or any combination of two or more of the listed items can be utilized. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A only; B only; C only; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C.

[0112]

[0121] As used herein, the term "comprising" "Comprises" and "comprise" are open-ended transitional terms used to transition from a subject listed before the term to one or more elements listed after the term, and the element or elements listed after the transitional term are not necessarily the single element that makes up the subject. As used herein, the terms "having," "has," and "have" have the same open-ended meaning as "including," "including," and "comprises" listed above. As used herein, the terms "including," "include," and "included" have the same non-limiting meaning as "including," "including," and "comprises" set forth above.

[0113]

[0122] As used herein, the term "about" means within 10 percent of the stated value. The present description uses numerical ranges to quantify certain parameters related to the present invention. It should be understood that when numerical ranges are provided, such ranges should be construed as providing literal support for claim limitations reciting only the upper limit of the range, as well as for claim limitations reciting only the lower limit of the range. For example, a disclosed numerical range of 10 to 100 provides literal support for claims reciting "greater than 10" (without an upper limit) and claims reciting "less than 100" (without a lower limit).

[0114]

[0123] In certain embodiments, multiple polymer or substrate layers create a laminate structure. In some embodiments, the polymer or substrate layer may be used in a manufacturing method. In such cases, the polymer or substrate layer may be described as a first or second polymer or substrate layer. As used herein, the terms "first," "second," and the like are used to describe various elements, but such elements should not necessarily be limited by these terms. These terms are used only to distinguish one element from another and do not necessarily imply a particular order or even a particular element. For example, an element may be considered a "first" element in this description and a "second" element in a claim without any conflict. While consistency will be maintained within this description and with respect to each independent claim, it is not intended that such terminology be consistent therebetween.

[0115]

[0124] Various interlayers and Examples of polymer interlayers and laminates containing these interlayers include, but are not limited to, the following: One skilled in the art will appreciate that the various combinations and properties can be varied as desired.

[0116]

[0125] A polymer interlayer is used to encapsulate the polymer volume hologram. The polymer interlayer may include a total amount of plasticizer within the range of -25 to +25 weight percent of the total amount of plasticizer in the polymer volume hologram. In embodiments, the polymer interlayer may include a total amount of plasticizer within the range of -15 to +15 weight percent, or -10 to +10 weight percent, or -5 to +5 weight percent of the concentration of plasticizer in the original polymer volume hologram.

[0117]

[0126] In embodiments, the polymer interlayer comprises between 0 and 50 weight percent of the interlayer. In embodiments, the polymer interlayer comprises a total amount of plasticizer in the range of 0 to 30 weight percent, or 0 to 20 weight percent, or 0 to 10 weight percent, or 0 to 5 weight percent of the interlayer.

[0118]

[0127] In embodiments, the polymer interlayer contains a concentration of a low refractive index plasticizer (LRIC). When a polymer interlayer is used to encapsulate the polymer volume hologram and laminated, the light modulating properties of the polymer volume hologram, after lamination and plasticizer equilibration with the polymer interlayer, are greater than 70%, greater than 80%, or greater than 90% of the magnitude of the original light modulating properties in at least one wavelength range. In embodiments, the LRIC in the HOE may be the same as the LRIC in the interlayer. In other embodiments, the LRIC in the HOE may be different from the LRIC in the interlayer. In other embodiments, the HOE may not contain an LRIC plasticizer prior to encapsulation and lamination (or equilibration) with the interlayer.

[0119]

[0128] In embodiments, the polymeric interlayer comprises a polymer or elastomer or blend of polymers or elastomers selected from polyurethanes, poly(vinyl acetals) such as poly(vinyl butyral), ethylene vinyl acetate copolymers, polyvinyl alcohol, cellulose esters, polyolefin elastomers, acrylics, polysiloxanes, and ionomers.

[0120]

[0129] In some embodiments, the polymer interlayer may be a plasticizer in a polymer volume hologram. In other embodiments, the polymer interlayer comprises at least one plasticizer or plasticizer blend that is different from the plasticizer or plasticizer blend in the polymer volume hologram.

[0121]

[0130] In embodiments, the polymer interlayer comprises a plasticizer or blend of plasticizers, The plasticizer blend, or plasticizers in the blend, is selected to have a refractive index within −0.1 to +0.1 of the refractive index of the plasticizer, plasticizer blend, or plasticizers in the blend in the original polymer volume hologram. In embodiments, the plasticizer or plasticizer blend is selected to have a refractive index within −0.05 to +0.05, or −0.02 to +0.02, of the refractive index of the plasticizer, plasticizer blend, or plasticizers in the blend in the original polymer volume hologram.

[0122]

[0131] In an embodiment, the multi-layer interlayer comprises a polymer interlayer and a polymer volume hologram. wherein the polymer interlayer is in direct contact with the polymer volume hologram. In other embodiments, the multi-layer interlayer comprises a polymer film, wherein the polymer film is adjacent to and disposed between the polymer interlayer and the polymer volume hologram. In other embodiments, the multi-layer interlayer comprises a bonding layer comprising any of the polymers described above, wherein the bonding layer is adjacent to and disposed between the polymer interlayer and the polymer volume hologram. In embodiments, the polymer film and / or bonding layer allow one or more plasticizers in the polymer interlayer to migrate into the polymer volume hologram. In embodiments, the polymer film and / or bonding layer allow one or more plasticizers in the polymer volume hologram to migrate into the polymer interlayer. In embodiments, the polymer film and / or bonding layer separates a portion of the polymer interlayer from the polymer volume hologram. In other embodiments, the polymer film and / or bonding layer separates the entire polymer interlayer from the polymer volume hologram.

[0123]

[0132] In embodiments, the polymer interlayer is a fully encapsulated polymer volume hologram. The plasticizer level is selected to minimize plasticizer incorporation so that the plasticizer level in grams is at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% of the starting level of plasticizer.

[0124]

[0133] In embodiments, the polymer interlayer may be 0.05 mm to 1.5 mm, 0.1 mm to It has a thickness of 0.8 mm or in the range of 0.2 mm to 0.4 mm.

[0134] In embodiments, the polymer interlayer and / or tie layer may further comprise an adhesion promoter. In embodiments, the adhesion promoter comprises a silane adhesion promoter. In embodiments, the adhesion promoter is incorporated into the polymer interlayer and / or tie layer.

[0125]

[0135] In embodiments, the polymer interlayer may provide acoustically tuned sound insulation characteristics, constant or variable angle These may have additional functionality such as wedges, dyes, particles, infrared or solar absorbers, or layers that selectively block portions of the electromagnetic spectrum.

[0126]

[0136] In an embodiment, the laminate comprises a first rigid substrate, a first polymer interlayer, an HOE film, and a second polymer interlayer. In an embodiment, the rigid substrate comprises a film, a second polymer interlayer, and a second rigid substrate. The substrate may be glass, polycarbonate, polyethylene terephthalate, acrylic, polyester, or any other rigid substrate known in the art. In embodiments, the first and second polymer interlayers are the same. In other embodiments, the first and second polymer interlayers are different. In embodiments, at least one of the first and second polymer interlayers is a multi-layer interlayer.

[0127]

[0137] In an embodiment, the laminate is disposed between the first polymer layer and the HOE film. In an embodiment, the laminate further comprises a tie layer disposed between the second polymer layer and the HOE film. In an embodiment, the laminate further comprises a tie layer disposed between both the first polymer layer and the HOE film and the second polymer layer and the HOE film.

[0128]

[0138] In an embodiment, the structure comprises a polymer volume hologram and a polymer volume hologram. and a polymer interlayer used to encapsulate the polymer volume hologram, wherein the polymer interlayer initially contains a concentration of a low refractive index compound, and the light modulating properties of the polymer volume hologram, after lamination and low refractive index compound equilibration with the polymer interlayer, are greater than 70% of the magnitude of the original light modulating properties of the original polymer hologram in at least one wavelength range.

[0129]

[0139] In an embodiment, the structure is a polymer volume hologram without a low refractive index compound. and a polymer interlayer used to encapsulate the polymer volume hologram, the polymer interlayer comprising a concentration of a low refractive index compound, wherein the light modulating properties of the polymer volume hologram, after lamination and low refractive index compound equilibration with the polymer interlayer, are greater than 70% of the magnitude of the original light modulating properties in at least one wavelength range. In embodiments, the light modulating properties of the polymer volume hologram, after lamination and low refractive index compound equilibration with the polymer interlayer, are greater than 80%, 90%, 100%, 200%, 300%, 400%, 500%, 600%, 700%, 800%, 900%, or 1000% of the magnitude of the original light modulating properties in at least one wavelength range.

[0130]

[0140] In an embodiment, the structure comprises a polymer volume hologram and a polymer volume hologram. and a polymer interlayer adjacent to the hologram, the polymer interlayer comprising a low refractive index compound at a concentration within the range of −25 to +25 weight percent of the concentration of the low refractive index compound in the polymer volume hologram.

[0131]

[0141] In embodiments, the polymer interlayer comprises between 0 and 50 weight percent of the structure. The total amount of low refractive index compounds in the

[0142] In embodiments, the polymer interlayer is selected from the group consisting of polyurethane, poly(vinyl butyral), The polymer or elastomer or blend of polymers or elastomers may be selected from poly(vinyl acetals) such as ethylene vinyl acetate copolymers, polyvinyl alcohol, cellulose esters, polyolefin elastomers, acrylic resins, polysiloxanes, and ionomers.

[0132]

[0143] In embodiments, the polymer interlayer is a low refractive index layer in the original polymer volume hologram. The low refractive index compound is selected to have a refractive index within the range of −0.1 to +0.1 of the refractive index of the compound.

[0133]

[0144] In an embodiment, the polymer interlayer is in direct contact with the polymer volume hologram. In embodiments, the multilayer interlayer comprises a polymer film or tie layer adjacent to and disposed between the polymer interlayer and the polymer volume hologram. In embodiments, the polymer film or tie layer is configured to allow one or more plasticizers in the polymer interlayer to pass from the polymer interlayer to the polymer volume hologram. This allows for transfer of the low refractive index compound from the polymer interlayer to the polymer interlayer, or from the polymer interlayer to the polymer volume hologram, and from the polymer volume hologram to the polymer interlayer. In embodiments, the polymer interlayer is selected so that the level of the low refractive index compound in the polymer volume hologram is at least 50% of the starting level of the low refractive index compound.

[0134]

[0145] In embodiments, the multi-layer interlayer further comprises a second polymer interlayer, or At least one of the first and second polymer layers is a multi-layer polymer interlayer.

[0146] In embodiments, the polymer interlayer comprises a polymer interlayer and a polymer volume hologram. Incorporating more than 50% of the low refractive index compound required for proper functionality of the complete laminate structure containing the ram.

[0135]

[0147] In an embodiment, a complete polymeric volume hologram containing a polymeric interlayer and a polymeric volume hologram is provided. There are non-patterned photosensitive polymer films made without refractive index-modifying plasticizers or plasticizer blends that are designed for the production of polymer volume hologram films for use in lamination with interlayers that contain refractive index-modifying plasticizers at levels greater than 50%, preferably greater than 75%, and preferably greater than 90% to achieve adequate functionalization of the laminate structure.

[0136]

[0148] In an embodiment, a complete polymeric volume hologram containing a polymeric interlayer and a polymeric volume hologram is provided. To achieve proper functionalization of the laminated structure, patterned polymer volume hologram films exist that do not employ refractive index-modifying plasticizers or plasticizer blends for use in lamination with interlayers that contain refractive index-modifying plasticizers at levels greater than 50%, preferably greater than 75%, and preferably greater than 90%.

[0137]

[0149] In embodiments, the polymer volume hologram may be patterned or unpatterned. Polymer volume holograms include photoactive polymer films and do not contain plasticizers during manufacture.

[0150] In embodiments, the gratings may be configured to exhibit the desired optical response following re-equilibration of the plasticizer after lamination. In embodiments, the light-modulating efficiency of the grating increases by at least 25%, at least 50%, at least 75%, at least 100%, at least 500%, or at least 1000% following re-equilibration of the plasticizer after lamination.

[0138]

[0151] In an embodiment, the manufacturing method comprises: This involves fabricating a low refractive index grating, the pattern of which is designed to achieve the desired pattern only after lamination and equilibration of the low refractive index compound.

[0139]

[0152] In embodiments, the substrate is glass, polycarbonate, polyethylene terephthalate, The polymer may be cellulose, acrylic, polyester, polyamide or cellulose triacetate.

[0153] In embodiments, the laminate comprises at least one substrate and a multilayer structure as described herein. Including any of the intermediate layers.

Claims

1. 1. A method of manufacturing a polymer volume hologram, comprising the steps of: providing a first polymer layer comprising a low refractive index compound; assembling the first polymer layer and the polymer volume hologram to form an assembly; providing at least a first substrate; and laminating the assembly and the at least first substrate to form a laminate structure, wherein the first substrate is adjacent to the first polymer layer; and the laminate structure has a level of low refractive index compound distributed within the polymer volume hologram such that light modulating properties of the polymer volume hologram, after lamination and equilibration of the low refractive index compound with the polymer interlayer, are greater than 70% of the magnitude of the original light modulating properties of the polymer hologram before assembly in at least one wavelength range.

2. The method of claim 1 , wherein the initial polymer volume hologram does not contain a low refractive index compound.

3. The method of claim 1 , wherein the initial polymer volume hologram comprises a low refractive index compound.

4. The method of claim 1 further comprising one or more additional polymer layers.

5. The method of claim 1 , wherein the polymer volume hologram is disposed on a second substrate.

6. The method of claim 1 further comprising a second substrate.

7. 7. The method of claim 3, wherein the low refractive index compound in the polymer layer is different from the low refractive index compound in the polymer volume hologram.

8. The method of claim 3 , wherein the low refractive index compound in the polymer layer is the same as the low refractive index compound in the polymer volume hologram.

9. The method of any one of claims 3 to 8, wherein the polymer interlayer comprises a low refractive index compound at a concentration within the range of -25 to +25 weight percent of the concentration of the low refractive index compound in the polymer volume hologram.

10. 10. The method of claim 1, wherein the polymer interlayer comprises a total amount of low refractive index compounds in the range of greater than 0 to less than 50 weight percent of the laminate structure.

11. 11. The method of any one of claims 1 to 10, wherein the polymeric interlayer comprises a polymer or elastomer or a blend of polymers or elastomers selected from polyurethanes, poly(vinyl acetals) such as poly(vinyl butyral), ethylene vinyl acetate copolymers, polyvinyl alcohol, cellulose esters, polyolefin elastomers, acrylics, polysiloxanes, and ionomers.

12. 12. The method of claim 3, wherein the low refractive index compound in the polymer interlayer is selected to have a refractive index within the range of −0.1 to +0.1 of the refractive index of the low refractive index compound in the polymer volume hologram.

13. The polymer film or tie layer may further comprise a polymer film or tie layer, wherein the one or more low refractive index compounds in the polymer interlayer are capable of transporting the polymer volume hologram from the polymer layer.

13. The method of claim 1, wherein the polymer volume hologram is transferred from the polymer interlayer to the ram, or from the polymer interlayer to the polymer volume hologram, and from the polymer interlayer to the polymer volume hologram.

14. The method of any one of claims 1 to 13, wherein the polymer layer further comprises an adhesion promoter.

15. 15. The method of any one of claims 1 to 14, wherein at least some of the polymer layers have at least one of: a tapered intermediate layer, acoustically regulating sound deadening properties, or an element that selectively blocks a portion of the electromagnetic spectrum, or the polymer layers include at least one of the following: dyes, colorants, pigments, particles, infrared or solar absorbers.

16. The method of claim 1 , wherein the low refractive index compound comprises at least two different low refractive index compounds.

17. The method of claim 1 , wherein the polymer volume hologram comprises a patterned or non-patterned photosensitive polymer film, and the polymer volume hologram does not contain a low refractive index compound before the assembly step.

18. 1. A method of manufacturing a polymeric volume hologram comprising: providing a first polymer layer comprising a low refractive index compound, a polymer volume hologram, and a second polymer layer; assembling the first polymer layer, the polymer volume hologram, and the second polymer layer to form an assembly, wherein the polymer volume hologram is between the first polymer layer and the second polymer layer; providing at least a first substrate; and laminating the assembly with the at least first substrate to form a laminate structure, wherein the laminate structure has a level of the low refractive index compound distributed within the polymer volume hologram such that the light modulating properties of the polymer volume hologram, after lamination and low refractive index compound equilibration with the polymer interlayer, are greater than 70% of the magnitude of the original light modulating properties of the polymer hologram before assembly in at least one wavelength range.

19. 19. The method of any one of claims 1 to 18, wherein the light modulating properties of the polymer volume hologram, after lamination and equilibration of the low refractive index compound with the polymer interlayer, are greater than 100% of the magnitude of the original light modulating properties of the pre-assembly polymer hologram in at least one wavelength range.

20. A laminated structure produced by the method according to any one of claims 1 to 19.

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