WO2021152413A1

WO2021152413A1 - Multilayer film with nanocomposite layer and glass layer

Info

Publication number: WO2021152413A1
Application number: PCT/IB2021/050270
Authority: WO
Inventors: Peter D. Condo; David Scott Thompson
Original assignee: 3M Innovative Properties Company
Priority date: 2020-01-29
Filing date: 2021-01-14
Publication date: 2021-08-05

Abstract

A multilayer film includes a glass layer with a thickness of less than 250 micrometers and a nanocomposite layer fixed to the glass layer. The nanocomposite layer includes at least one polymer and metal oxide nanoparticles dispersed in the at least one polymer. The at least one polymer includes a first polymer including (meth)acrylic acid monomer units. The metal oxide nanoparticles are surface modified with a carboxylic acid silane surface modifying agent. The multilayer film can include additional layers such as a low surface energy coating or a transparent energy dissipation layer. The multilayer film can be a transparent protective display film.

Description

MULTILAYER FILM WITH NANOCOMPOSITE LAYER AND GLASS LAYER

Background

Displays and electronic devices have evolved to be curved, bent, or folded and provide new user experiences. These device architectures may include flexible organic light emitting diodes (OLEDs) or plastic liquid crystal displays (LCDs), for example.

Summary

The present disclosure generally relates to multilayer films including a polymeric or nanocomposite layer and a glass layer. The multilayer film can be a display film for protecting a display and may survive flexing, folding or impact tests. The protective display film may maintain optical properties of a display film while providing impact and scratch resistance to the display. The display film may include a transparent anti-shatter layer disposed on a glass layer.

In some aspects, a multilayer film is provided. The multilayer film includes a glass layer with a thickness of less than 250 micrometers, or in a range from 25 to 100 micrometers. A nanocomposite layer is fixed to the glass layer. The nanocomposite layer includes at least one polymer and metal oxide nanoparticles dispersed in the at least one polymer. The at least one polymer includes a first polymer including (meth)acrylic acid monomer units (acrylic acid monomer units, methacrylic acid monomer units, or both acrylic acid and methacrylic acid monomer units). The metal oxide nanoparticles are surface modified with a surface modifying agent comprising a carboxylic acid silane of formula 1 :

Formula 1 where R1 is a Ci to Cio alkoxy group; R2 and R3 are independently selected from the group consisting of Ci to Cio alkyl and Ci to Cio alkoxy groups; and A is a linker group selected from the group consisting of Ci to Cio alkylene or arylene groups, Ci to Cio aralkylene groups, C2 to Ci₆ heteroalkylene or heteroarylene groups, and C2 to Ci₆ amide containing groups.

The multilayer film may include additional layers. For example, an additional nanocomposite layer may be fixed to the glass layer on the side opposite the nanocomposite layer. The additional nanocomposite layer may be as described for the nanocomposite layer. The additional nanocomposite layer may optionally be replaced with a layer of the at least one polymer without the metal oxide nanoparticles. In some embodiments, a transparent energy dissipation layer is fixed to the glass layer (or affixed to the additional nanocomposite layer) on the side opposite the nanocomposite layer. The transparent energy dissipation layer has a glass transition temperature of 27 degrees Celsius or less, a Tan Delta peak value of 0.5 or greater, or from 1 to 2, and/or a Young’s Modulus (E') greater than 0.9MPa over the temperature range of -40 degrees Celsius to 70 degrees Celsius. The transparent glass layer separates the transparent energy dissipation layer from the nanocomposite layer. The transparent energy dissipation layer may include a cross-linked polyurethane or a cross-linked polyurethane acrylate.

These and other aspects will be apparent from the following detailed description. In no event, however, should this brief summary be construed to limit the claimable subject matter.

Brief Description of the Drawings

FIGS. 1-5 are schematic diagram side elevation views of illustrative multilayer films;

FIG. 6 is a schematic illustration of an illustrative stress-strain curve;

FIGS. 7-12 are schematic diagram perspective views of display articles including illustrative multilayer films;

FIG. 13 is an image of multilayer film including a nanocomposite layer and a glass layer after being bent around a mandrel and broken where the nanocomposite layer prevented the glass layer from shattering; and

FIG. 14 is an image of multilayer film including a nanocomposite layer and a glass layer after being bent around a mandrel and shattered.

Detailed Description

In the following description, reference is made to the accompanying drawings that form a part hereof and in which various embodiments are shown by way of illustration. The drawings are not necessarily to scale. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present description. The following detailed description, therefore, is not to be taken in a limiting sense.

Flexible and foldable display architectures represent a new paradigm for displays and provide for significant expansion of design freedom and new form factors that may provide significant new value to consumers. One challenge is the outer protective layer on the display device, sometime referred to as cover glass, cover window films, or cover window sheets. Recent mobile displays have focused on the use of chemically strengthened glass sold under trade names like Gorilla Glass and Dragon Glass. In use these cover glasses tend to have thicknesses in the range of at least 400-500 micrometers in total thickness and provide a gloss surface to the displays and with proper coatings have low coefficient of friction and anti-reflective surfaces. One challenge with these cover glasses is that the emergence of flexible and foldable displays places a requirement on the cover glass surface in that it may be flexed or bent and in the case of folding may need to fold with bend radii of <10mm or <5mm or <3mm or even 1mm. A variety of hard coated plastic substrates have been explored. More exotic materials like hard coated colorless transparent polyimide films have been shown to have high hardness and good scratch resistance. However, many hard coated films fail to withstand folding events around a tight bend radius or impact events without showing visible damage.

Conventional ionic elastomers possess some of desired properties such as high visible transmission and low haze, chemical resistance, and flexibility. However, conventional ionic elastomeric polymers lack the desired mechanical features or abrasion resistance, impact resistance, tensile modulus, for example, desired for a protective layer in a display film.

Particulate fillers have been incorporated into polymers to improve mechanical properties. However, the vast majority of commercially available filled polymers are opaque and thus are unsuitable for use in optical articles. Additionally, rigid particulate fillers can adversely affect the flexibility properties of the polymers with which they are combined.

One technique for providing modified properties is to blend polymeric materials. This approach can be problematic as the preparation of blends to improve one property, such as flexibility, can adversely affect other properties, such as optical properties. This is especially true for optical properties, since the vast majority of polymer blends have at least some degree of immiscibility. A lack of miscibility can dramatically affect optical properties such as visible light transmission, haze and clarity. Even polymers that have the same or similar monomeric composition can be immiscible, if, for example, the polymers have differing degrees of branching. Thus, modification of a polymeric composition by blending the polymeric composition with another polymer, even a seemingly similar polymer, is not a trivial undertaking, especially when the blended composition has desired optical properties. It has been unexpectedly found that blends of different polymers including similar content of (meth)acrylic acid monomer units provide improved mechanical properties while maintaining desired optical properties (e.g., high optical transparency and/or low optical haze).

The multilayer films of the present disclosure achieve the contradictory goals of flexibility, optical transparency and improved mechanical properties, according to some preferred embodiments. The nanocomposite layers of the multilayer film typically include a polymeric matrix and a surface-modified nanoparticle filler. The polymeric matrix, which may also be referred to as a polymeric phase, includes at least one polymer (e.g., a polymer or a blend of polymers).

The nanocomposite layers of the present disclosure utilize metal oxide nanoparticles, which are particles with an average diameter that is in the nanometer range. These particles give improved mechanical properties to the nanocomposites, and because of their small size, according to some embodiments, the nanoparticles do not appreciably scatter visible light. The nanoparticles can be surface modified to achieve compatibility with the at least one polymer to avoid agglomeration or aggregation of the nanoparticles in the nanocomposite which would lead to inferior optical properties. The surface modifying agent is typically a carboxylic acid-functional silane. While not wishing to be bound by theory, it is believed that the acid-functional groups on the surface modifying agent improve the compatibility of the particles with the acid-functional (meth)acrylic polymer(s) of the at least one polymer. Some of the acid-functional groups on the surface-modified nanoparticles may also be neutralized like at least some of the acid-functional groups on the (meth)acrylic polymer(s). Acid-functional groups in the surface modifying agent are preferred for dispersibility of the nanoparticles in water. The acid groups of the acid silane, when added to the basic surface unmodified nanoparticle solution (for example, NACLO 2327), are at least partially neutralized which renders the silane soluble in the aqueous phase such that the surface of the silica can be modified readily. Furthermore, it has been found that in the coating and melt processing of the ionic elastomer nanocomposite materials that the acid silane on the surface of the particles can allow for interaction of the nanoparticles with the ionic groups of the elastic ionomer polymers leading to excellent compatibility of the nanoparticles in the host polymer matrix.

The present disclosure relates to multilayer display film with glass that protects a display and may survive flexing, folding or impact tests. According to some embodiments, the protective display film maintains optical properties of a display film while providing impact and scratch resistance to the display. The display film typically includes a transparent anti-shatter layer disposed on a glass layer.

The terms “display film”, “protective film”, “cover sheet film”, and “protective display film” are herein used interchangeably.

“Transparent substrate” or “transparent layer” refers to a substrate or layer that has a high light transmission (typically greater than 90%) over at least a portion of the surface of the substrate over at least a portion of the light spectrum with wavelengths of about 350 to about 1600 nanometers, including the visible light spectrum (wavelengths of about 380 to about 750 nanometers). “Polyurethane” refers to polymers prepared by the step-growth polymerization of hydroxyl-functional materials (materials containing hydroxyl groups — OH) with isocyanate- functional materials (materials containing isocyanate groups — NCO) and therefore contain urethane linkages ( — O(CO) — NH — ), where (CO) refers to a carbonyl group (C=0). The term may include “polyurethane-ureas” in which both urethane linkages and urea linkages are present.

“Polyurethane acrylate” refers to a polymer that includes primarily urethane and acrylate moieties or segments.

The phrase “glass transition temperature” refers herein to the “on-set” glass transition temperature by DSC and is measured according to ASTM E1256-082014.

The phrase “Tan Delta peak value” and peak temperature is measured according to the DMA analysis described in the Examples.

The terms “miscible” or “miscibility” refer to at least two polymers that are compatible with each other such that blends of the at least two polymers do not phase separate so as to form phase separated microdomains that are large enough to produce significant scattering of visible light (wavelengths of about 400 to about 700 nm).

The terms “immiscible” or “immiscibility” refer to at least two polymers that are incompatible with each other such that blends of the at least two polymers phase separate so as to form phase separated microdomains that are large enough to produce significant scattering of visible light (wavelengths of about 400 to about 700 nm) resulting in unacceptable haze.

The term “protective layer” may also be referred to as an abrasion resistant or anti-shatter layer. The protective layer may also be referred to as an “elastic ionomer nanocomposite layer”.

The present disclosure relates to multilayer films such as display films with glass that protect a display or display window and may survive flexing, folding or impact tests. The protective display film maintains optical properties of a display film while providing durability to the display. The multilayer film includes a nanocomposite layer which is preferably transparent, and which may be referred to as a transparent protective layer. In some embodiments, the transparent protective layer of a protective display film provides a layer that can contain glass fragments in the event the glass of the protective display film breaks or fractures.

According to some embodiments, these constructions enable curved, bendable, and dynamically reconfigurable displays that are both optically clear and meet the surface abrasion and impact resistance demands while maintaining the display form factor. The protective display film generally includes an elastic ionomer nanocomposite layer directly fixed to a thin glass layer. The elastic ionomer nanocomposite layer also provides protection to the display user in that it can act as an anti-shatter or anti-splinter film to contain glass fragments in the event the glass of the protective display film breaks or fractures. According to some embodiments, this protective display fdm enables displays to survive impact events and recover from bending. The protective display fdm includes at least one layer of ionomer nanocomposite fixed to a thin glass layer. The thin glass layer may be less than 500 micrometers, or less than 250 micrometers, or less than 200 micrometers, or less than 100 micrometers or less than 50 micrometers. The nanocomposite layer may be positioned to be the outer surface of the display. Alternatively, and additional hardcoat layer and/or a low surface energy layer may be disposed on the nanocomposite layer facing away from the display. The average thickness (unweighted mean thickness over an area of the layer) of the nanocomposite layer can be in the range of 5 to 250 micrometers, or 5 to 125 micrometers, or 5 to70 micrometers, or preferably 5 to 30 micrometers.

The protective display film can include a layered structure including other layers disposed on the side opposite the nanocomposite layer. These additional layers may include additional layers of nanocomposite, layers of elastic ionomer, and energy dissipating layers.

Energy dissipation layers may be a cross-linked polymer such as a cross-linked polyurethane material or a cross-linked polyurethane acrylate material. The energy dissipation layer is transparent and may have a glass transition temperature of less than 27 degrees Celsius, or less than 10 degrees Celsius, or less than 5 degrees Celsius. The protective display film may protect flexible optical displays even under conditions of dynamic folding. The energy dissipation layer may have a low glass transition temperature, such as 5 degrees Celsius or less, or zero degrees Celsius or less, or -5 degrees Celsius or less, or -10 degrees Celsius or less or in a range from -40 to 5 degrees Celsius, or in a range from -30 to 5 degrees Celsius, or in a range from -20 to 5 degrees Celsius, or in a range from -15 to 5 degrees Celsius. The energy dissipation layer has a Tan Delta peak value of 0.5 or greater, or 0.8 or greater, or 1.0 or greater, or 1.2 or greater. The energy dissipation layer or layers have a Young’s Modulus (E') greater than 0.9MPa over the temperature range of -40 degrees Celsius to 70 degrees Celsius. Other optional border elements may be created by die-cut (or otherwise converted) decorative film inserted between any layer(s) in the display film construction. While the present disclosure is not so limited, an appreciation of various aspects of the disclosure will be gained through a discussion of the examples provided below.

FIG. 1 is a schematic diagram side elevation view of an illustrative multilayer film 100. The multilayer film 100 can be a display film. The terms “display film”, “cover film”, “protective film”, “protective cover film” or “protective display film” are used interchangeable herein. The multilayer film 100 includes a glass layer 120 (preferably a transparent glass layer) and a nanocomposite layer 110 (e.g., a transparent elastic ionomer nanocomposite layer) disposed on the glass layer 120. The nanocomposite layer 110 includes at least one polymer 112 and metal oxide nanoparticles 114. The nanocomposite layer 110 is directly fixed to the glass layer 120. By directly fixed, it is meant that the nanocomposite layer is in direct contact to the glass. In some embodiments, the surface of the glass may be treated to enhance adhesion of the nanocomposite layer, but such treatment should not provide any significant change in thickness to the glass. Examples of such treatment may include acid or base etching of the glass surface, ion implantation at the surface designed to interact with the ionomer nanocomposite or for example silane treatment the glass surface to provide an associative or reactive group to which the ionomer nanocomposite layer can bond either covalently or no-covalently (for example hydrogen bonding or ionic bonding). The thickness of such surface treatment should not exceed lOOnm in thickness. The thickness of the nanocomposite layer 110 can be in the range of 5-125 microns, 5-70 microns, or 5-50 microns. In some exemplary cases, the thickness is in the range of 5-30 microns.

The surface of the nanocomposite 110 may be optionally provided with a low surface energy coating 105 to enhance abrasion resistance and provide improved tactile feel of the surface as described further elsewhere herein. The low surface energy coating 105 can result in a high static contact angle. A static water contact angle Q, which may be at least 100 degrees or at least 110 degrees is schematically illustrated in FIG. 1.

FIG. 2 is a schematic diagram side elevation view of an illustrative multilayer film 200 (e.g., a display film) that includes an additional (meth)acrylic acid layer 115 on the thin glass on the side opposite the outer nanocomposite layer (e.g., elastic ionomer nanocomposite layer) such that the thin glass layer 120 separates the nanocomposite layer 110 and the layer 115 which is typically an elastic ionomer layer. The display film 200 includes a glass layer 120 and a nanocomposite layer 110 disposed on the glass layer 120. The (e.g., transparent elastic ionomer) nanocomposite layer 110 and the (e.g., elastic ionomer) layer 115 are both directly fixed to the glass layer 120. As in the description of Figure 1, the surface of the glass may be treated to enhance adhesion of the nanocomposite layer, but such treatment should not provide any significant change in thickness to the glass. The thickness of such surface treatment should preferably not exceed 100 nm in thickness. The surface of the nanocomposite 110 may be optionally provided with a low surface energy coating 105 to enhance abrasion resistance and provide improved tactile feel of the surface, as described further elsewhere herein.

FIG. 3 is a schematic diagram side elevation view of an illustrative multilayer film 300 which may be a display film. The multilayer film 300 includes a glass layer 120 and a (e.g., transparent elastic ionomer) nanocomposite layer 110 disposed on the glass layer 120. The nanocomposite layer 110 is directly fixed to the glass layer 120. An additional layer 130 (e.g., transparent energy dissipation layer) may be directly fixed or coupled to the glass layer 120. When the additional layer 130 is a transparent energy dissipation layer, the transparent energy dissipation layer preferably has a glass transition temperature of 27 degrees Celsius or less and a Tan Delta peak value of 0.5 or greater, or from 1 to 2.

The transparent energy dissipation layer may, in some embodiments, not be a pressure sensitive adhesive or function as a pressure sensitive adhesive. For example, the transparent energy dissipation layer may have a Young’s Modulus larger than 0.9 MPa over the temperature range -40 degrees Celsius to 70 degrees Celsius. In some embodiments, the nanocomposite layer may have a Young’s Modulus and/or a shear modulus, larger than 0.9 MPa at 20 degrees Celsius.

The surface of the elastomeric ionomer nanocomposite 110 may be optionally provided with a low surface energy, low coefficient of friction coating 105 to provide improved tactile feel of the surface, as described further elsewhere herein.

FIG. 4 is a schematic diagram side elevation view of an illustrative multilayer film 400 (e.g., a display film) that includes a nanocomposite layer 110 (e.g., an elastic ionomer nanocomposite layer) and an additional layer 115 (e.g., an additional elastic ionomer layer) fixed on opposing sides of the thin glass such that the thin glass layer 120 separates the nanocomposite layer 110 and the additional layer 115. A layer 130 (e.g., a transparent energy dissipation layer) is directly fixed to the additional layer 115, such that the additional layer 115 separates the thin glass 120 and the layer 130. The additional layer 115 may be referred to as a first additional layer and the layer 130 may be referred to as a second additional layer. The surface of the elastomeric ionomer nanocomposite 110 may be optionally provided with a low surface energy and/or low coefficient of friction coating 105 to provide improved tactile feel of the surface as described further elsewhere herein. In some embodiments, the multilayer film 400 is a display film including, in order from an outer surface of the film, a coating 105, an elastic ionomer nanocomposite layer (layer 110), a thin glass layer 120, an additional elastic ionomer layer (additional layer 115), and a transparent energy dissipation layer (layer 130).

FIG. 5 is a schematic diagram side elevation view of an illustrative multilayer film 500 (e.g., display film) that includes a nanocomposite layer 110 (e.g., an elastic ionomer nanocomposite layer) and a substrate 150 with a hardcoat layer 170. The nanocomposite layer 110 is disposed between a thin glass layer 120 and the substrate layer 150 and is fixed on both the thin glass layer 120 and the substrate 150 surfaces, meaning the nanocomposite layer is in contact with the surface and no adhesive layer is present between the layers. The substrate layer 150 separates the hardcoat layer 170 from the nanocomposite layer 110. As in the description of Figure 1, the surface of the glass may be treated to enhance adhesion of the ionomer nanocomposite layer, but such treatment should not provide any significant change in thickness to the glass. Likewise, the surface of the substrate 150 may be treated to enhance adhesion to the nanocomposite layer 110. Surface treatments for the substrate layer may include treatment with an atmospheric plasma, plasma etching processes to nano roughen the surface and reactive coatings, for example a silane with a functional group designed to interact with the elastic ionomer nanocomposite. The thickness of such surface treatments for should not exceed lOOnm in thickness. The surface of the hardcoat layer 170 may be optionally provided with a low surface energy and/or low coefficient of friction coating 105 to provide improved tactile feel of the surface as described further elsewhere herein.

In any of the embodiments of FIGS. 1-5, for example, the nanocomposite layer 110 may be bonded directly to, and substantially coextensive with, the glass layer 120. Similarly, any other two layers illustrated as being immediately adjacent one another may be bonded directly to, and substantially coextensive with, each other. Two layers described as substantially coextensive means that the two layers extend over a common area being at least 70 percent of an area of the larger (by area) of the two layers, unless the context clearly indicates differently. In some cases, the common area is at least 80 percent or at least 90 percent of the area of the larger of the two layers.

A further display film embodiment includes an elastic ionomer nanocomposite layer disposed on a liner film, for example an unprimed polyester (PET) film layer where a premask film has been applied to the opposite surface of the elastic ionomer nanocomposite layer, where the elastic ionomer layer separates the liner film and the premask film. A further display embodiment includes an elastic ionomer layer disposed on a liner film, for example an unprimed polyester (PET) film layer where a premask film has been applied to the opposite surface of the elastic ionomer layer, where the elastic ionomer layer separates the liner film and the premask film. A further display film embodiment includes an energy dissipation layer separating two release liners. A further display film embodiment includes an energy dissipation layer separating a release liner from an adhesive layer, and a second release liner is disposed on the adhesive layer. The adhesive layer may be an optically clear adhesive layer, as described herein or a pressure sensitive adhesive layer, or any adhesive or coupling layer described herein.

The illustrative display film constructions may include an ink border that defines a viewing window. The ink border may be a continuous frame element printed, for example, onto the glass layer or the energy dissipation layer, for example.

The film may include one or more additional layers. Additional layers may include conductive layers for touch sensitive display elements or barrier layers. One or more additional transparent polymeric substrate layers may be disposed in the display film of any useful polymeric material that provides desired mechanical properties (such as dimensional stability) and optical properties (such as light transmission and clarity) to the display film. Examples of materials suitable for use in the polymeric substrate layer include polymethylmethacrylate, polycarbonate, polyamides, polyimide, polyesters (PET, PEN), polycyclic olefin polymers, and thermoplastic polyurethanes.

The optional one or more barrier layers may include a transparent barrier layer. The transparent barrier layer may be disposed on the glass layer or the elastic ionomer nanocomposite layer or the energy dissipation layer. The transparent barrier layer can mitigate or slow ingress of oxygen or water through the display film. Transparent barrier layers may include for example, thin alternating layers of silica, alumina or zirconia together with an organic resin. Exemplary transparent barrier layers are described in US7,980,910 and W02003/094256.

Optional additional layers may include a microstructure layer, an anti-glare layer, anti- reflective layer, or an anti-fingerprint layer. Additional optional layers may be disposed in the interior of the display film. One useful additional layer disposed within the display film is a sparkle reduction layer as described in WO2015/191949. The sparkle reduction layer may be particularly useful with high definition displays that include anti -glare coatings.

The overall thickness of the display film described herein may have any useful value depending on the application. The thickness of the display film is a balance between being thick enough to provide the desired display protection and thin enough to provide the level of flexibility desired for the device application and reduced thickness to meet desired design parameters. In some cases, the level of flexibility desired is a display film having a bend radius of 40mm or less, 20mm or less, 10mm or less, 7mm, or less, 5 mm or less, or 4 mm or less, or 3 mm or less or in a range from 1 to 20 mm, a range from 1 to 10mm, a range from 1 to 7mm, or a range of from 1 to 5mm. The overall thickness of the display film may be in a range from 30 to 300 micrometers, or from 40 to 200 micrometers, or from 40 to 150 micrometers. When the display film folds upon itself, it may have a total thickness in a range from 30 to 200 micrometers or from 40 to 150 micrometers. When the display film moderately flexes, it may have total thickness in a range from 300 to 500 micrometers. When the display film is curved but does not appreciably flex, it may have total thickness in a range from 500 to 1000 micrometers.

The multilayer films described herein may have a haze value of 4% or less, 3% or less, 2% or less, or 1.5% or less, or 1% or less, or 0.5% or less. In some embodiments the film may have a haze value of 5% or less. The multilayer film may have a clarity of 95% or greater, 97% or greater, 98% or greater, or 99% or greater. The multilayer film may have a visible light transmission of 85% or greater, or 90% or greater, or 93% or greater.

The multilayer film may have a yellow index or b* value of 5 or less, or 4 or less, or 3 or less, or 2 or less, or 1 or less. In many embodiments, the multilayer film may have a yellow index or b* value of 1 or less. The glass layer 120 may be formed of any useful glass material. The glass layer 120 may be treated to provide beneficial properties. For example, the glass layer 120 may be ion implanted, chemically strengthened or tempered, and the like. The glass layer 120 may have a thickness that is appropriate for a given bend radius or radius of curvature. The glass layer 120 may have an average thickness (unweighted mean over an area of the glass layer) of 500 micrometers or less, or 300 micrometers or less, or 250 micrometers or less, or from 10 to 200 micrometers, or from 25 to 100 micrometers, or from 25 to 50 micrometers. Suppliers of thin transparent glass include Coming, Nippon Electric Glass, Schott and Asahi Glass.

The nanocomposite layer 110 is typically an elastic ionomer nanocomposite layer that includes metal oxide nanoparticles. This layer may have a thickness in a range of 5-125 microns, 5-70 microns, or 5-50 microns. In some exemplary cases, the thickness is in the range of 5-30 microns. The elastic ionomer nanocomposite layer is capable of stretching within an elastic range, so that permanent deformation does not occur. The proportional limit for a material is defined as the maximum stress at which the stress is proportional to strain (Hooke's law). The elastic limit is the minimum stress at which permanent deformation can be measured. The elastic ionomer nanocomposite layer may have a strain at the elastic limit that is 10% greater than the strain at the proportional limit, 20% greater than the strain at the proportional limit, 50% greater than the strain at the proportional limit, or 100% greater than the strain at the proportional limit. The graph shown in FIG. 6 illustrates this concept.

Compositions suitable for use in the nanocomposite layer 110 include nanocomposites that include at least one (meth)acrylic polymer (e.g., one (meth)acrylic polymer or two or more miscible (meth)acrylic polymers) and surface-modified metal oxide nanoparticles, where the surface-modified metal oxide nanoparticles are surface modified with an acid-functional silane surface modifying agent, and where the (meth)acrylic polymer(s) are at least partially neutralized. The nanocomposites may be melt processable into films that are optically transparent. By melt processable it is meant that the nanocomposites are able to be melt processed, that is to say that the nanocomposites can be heated and made to flow without causing degradation. Melt processable does not mean that the nanocomposite has been melt processed and in no way indicates a processing step. The elastic ionomer nanocomposites may also be made by coating processes from aqueous dispersions on to a substrate such that the film can be removed from the substrate or transferred to another layer like thin glass layer 120

A wide range of (meth)acrylic polymers are suitable for use in the nanocomposites of this disclosure. The (meth)acrylic polymer(s) include (meth)acrylic acid monomers units (i.e., acrylic acid monomer units, methacrylic acid monomer units, or both acrylic acid monomer units and methacrylic acid monomer units). In some embodiments, the (meth)acrylic polymers are homopolymers of acrylic acid or methacrylic acid. In other embodiments, the (meth)acrylic polymers are copolymers of at least one (meth)acrylic monomer unit that is acid-functional and at least one monomer that is a (meth)acrylate that is not acid-functional. Additionally, the (meth)acrylic polymers can contain other non-(meth)acrylate monomers that are co-polymerizable with the (meth)acrylic and (meth)acrylate monomers. The copolymers can be formed by the polymerization or copolymerization using free radical polymerization techniques. In some embodiments, the at least one (meth)acrylic polymer includes a copolymer containing (meth)acrylic acid and at least one co-monomer. A wide range of co-monomers are suitable. Suitable co-monomers include ethylene, propylene, alkyl(meth)acrylates, aryl(meth)acrylates, alkaryl(meth)acrylates, acrylonitrile, and carbon monoxide.

In some embodiments, a nanocomposite includes at least one polymer and metal oxide nanoparticles dispersed in the at least one polymer of the nanocomposite. Each polymer can have a number average molecular weight of at least 10000 grams/mole. The at least one polymer of the nanocomposite includes a first polymer including (meth)acrylic acid monomer units (monomer units selected from the group consisting of methacrylic acid monomer units and acrylic acid monomer units). The metal oxide nanoparticles are surface modified with a surface modifying agent including a carboxylic acid silane of Formula 1 described elsewhere herein.

In some embodiments, the first polymer has a number average molecular weight of at least 12000 grams/mole or at least 15000 grams/mole. In some embodiments, each polymer of the at least one polymer has a number average molecular weight of at least 12000 grams/mole or at least 15000 grams/mole. For example, the at least one polymer can be a blend of first and second polymers, and each of the first and second polymers can have a number average molecular weight of at least 12000 grams/mole or at least 15000 grams/mole. The number average molecular mass of a polymer can be determined by gel permeation chromatography (GPC). Polymer characterization by GPC systems is well known. An example of such a system is the Viscotek TDAmax (Malvern Panalytical, a part of Spectris pic). This system is equipped with multiple detectors for determination of molecular weight. Absolute molecular weight of small polymers can be measured using a right angle light scattering detector, direct output of absolute molecular weight of polymers without extrapolation can be obtained using low angle light scattering. Additional detectors can be used to assess information concerning polymer structure, for example branching using intrinsic viscosity detector and information concerning copolymer composition can be investigated using a photodiode array UV detector when UV absorbing components are present. Further details of this instrument can be found from the supplier. In some embodiments, the first polymer, or each polymer of the at least one polymer, has a number average molecular weight less than 100,000 grams/mole. In some embodiments, the first polymer further includes at least one monomer unit (e.g., a second type of monomer unit when the (meth)acrylic acid monomer units are a first type of monomer unit) selected from the group consisting of ethylene, propylene, alkyl(meth)acrylates, aryl(meth)acrylates, alkaryl(meth)acrylates, acrylonitrile, and carbon monoxide. In some embodiments, the first polymer includes at least one monomer unit (e.g., a second type of monomer unit) selected from the group consisting of ethylene and propylene. In some such embodiments, the first polymer further includes at least one monomer unit (e.g., a third type of monomer unit) selected from the group consisting of n-butyl acrylate, isobutyl acrylate, isopropyl acrylate, n-propyl acrylate, ethyl acrylate, methyl acrylate, 2-ethylhexyl acrylate, iso-octyl acrylate and methyl methacrylate. The first polymer can be aterpolymer, for example. In some embodiments, the first polymer includes (meth)acrylic acid monomer units; ethylene monomer units, propylene monomer units, or a combination of ethylene and propylene monomer units; and at least one alkyl (meth)acrylate monomer unit. In some embodiments, the first polymer includes (meth)acrylic acid monomer units and ethylene monomer units.

The at least one polymer can be a blend of two or more (meth)acrylic polymers. A wide range of blends of (meth)acrylic polymers are suitable. Examples of suitable blends include blends of acrylic acid or methacrylic acid homopolymers with copolymers of acrylic acid or methacrylic acid and at least one additional monomer (e.g., selected from the group consisting of ethylene, propylene, alkyl(meth)acrylates, aryl(meth)acrylates, alkaryl(meth)acrylates, acrylonitrile, and carbon monoxide). Other examples include blends of acrylic acid or methacrylic acid homopolymers with copolymers of acrylic acid or methacrylic acid and at least two additional monomers (e.g., the copolymer can be aterpolymer). In some embodiments, the blends include a copolymer of acrylic acid or methacrylic acid and at least one additional monomer with a different copolymer of acrylic acid or methacrylic acid and at least one additional monomer. Yet other embodiments include blends of a copolymer of acrylic acid or methacrylic acid and at least one additional monomer with a copolymer of acrylic acid or methacrylic acid and at least two additional monomers. Additionally, the blend can also include different copolymers of acrylic acid or methacrylic acid and at least two additional monomers.

In some embodiments, the at least one polymer includes a second polymer different from the first polymer. The first and second polymers can be different by virtue of having different molecular weights, different acid content, different neutralization percent, different amounts of the same monomer units, and/or by being compositionally distinct, for example. In some embodiments, the second polymer is compositionally distinct from the first polymer. Compositionally distinct in this context can be understood to mean that at least one of the first and second polymers has a least one type of monomer unit not present in the other of the first and second polymers. For example, the first polymer can include two different monomer units (e.g., (meth)acrylic acid and either ethylene or propylene) and the second polymer can include a different third monomer unit (e.g., n-butyl acrylate or isobutyl acrylate) in addition to the two monomer units of the first polymer. Compositionally distinct includes different acid types (e.g., methacrylic acid monomer units versus acrylic acid monomer units) and different ion types (an ion at least partially neutralizing an ionomer can be considered to be part of the ionomer), for example. The second polymer can have a number average molecular weight of at least 10000 grams/mole, or at least 12000 grams/mole, or at least 15000 grams/mole.

In some embodiments, the second polymer includes (meth)acrylic acid monomer units. In some embodiments, the second polymer includes at least one monomer unit selected from the group consisting of ethylene, propylene, alkyl(meth)acrylates, aryl(meth)acrylates, alkaryl(meth)acrylates, acrylonitrile, and carbon monoxide. In some embodiments, the second polymer includes at least one monomer unit selected from the group consisting of ethylene and propylene. In some such embodiments, the second polymer further includes at least one monomer unit selected from the group consisting of n-butyl acrylate, isobutyl acrylate, isopropyl acrylate, n- propyl acrylate, ethyl acrylate, methyl acrylate, 2-ethylhexyl acrylate, iso-octyl acrylate and methyl methacrylate. In some embodiments, the second polymer includes (meth)acrylic acid monomer units; ethylene monomer units, propylene monomer units, or a combination of ethylene and propylene monomer units; and at least one alkyl (meth)acrylate monomer unit. In some embodiments, the second polymer includes (meth)acrylic acid monomer units and ethylene monomer units.

In some embodiments, the content of (meth)acrylic acid monomer units in the first polymer, and optionally in the second polymer, is greater than 12 weight percent. This has been found to help in dispersing the first polymer, and optionally the second polymer, in water. In some embodiments, the content of (meth)acrylic acid monomer units in the first and the second polymers is similar. This has been found to help the compatibility of the polymers and to improve optical properties, for example. In some embodiments, the first polymer includes (meth)acrylic acid monomer units at a first weight percent wl, and the second polymer includes (meth)acrylic monomer units at a second weight percent w2. In some embodiments, at least one of wl and w2 (wl, or w2, or each of wl and w2) is greater than 12 weight percent, or greater than 13 weight percent, or greater than 14 weight percent, or greater than 15 weight percent. In some embodiments, at least one of wl and w2 is less than 50 weight percent, or less than 30 weight percent, or less than 25 weight percent. In some such embodiments, or in other embodiments, |wl- w2| is less than 15 weight percent or less than 14 weight percent, or less than 12 weigh percent, or less than 10 percent, or less than 8 percent, or less than 7 weight percent, or less than 6 weight percent. Smaller values of the difference |wl-w2| may be preferred when both the first and second polymers are formed from an aqueous dispersion, while larger values of the difference may be useful, in some embodiments, when the second polymer is added in a melt processing step.

In some embodiments, the nanocomposite is formed from an aqueous dispersion including the first and second polymers as described further elsewhere herein. In some such embodiments, or in other embodiments, each of wl and w2 is greater than 12 weight percent, or greater than 13 weight percent, or greater than 14 weight percent, or greater than 15 weight percent. In some such embodiments, or in other embodiments, |wl-w2| is less than 10 weight percent, or less than 9 weight percent, or less than 8 weight percent, or less than 7 weight percent, or less than 6 weight percent. In some embodiments, |wl-w2| is in a range of 0 to 10 weight percent or in a range of 0 to about 9 weight percent (e.g., 8.8 or 9 or 9.2 weight percent can be considered to be about 9 weight percent). In some cases, where each of the two polymers in dispersion includes two monomer units (e.g., a (meth)acrylic acid monomer unit and a second monomer unit such as ethylene or propylene), the acid content of either the first polymer (wl) or second polymer (w2) may be in a range greater than 27 weight percent, for example. When one of the two polymers (e.g., the first polymer) has an acid content of greater than 27%, the difference |wl-w2| may be up to 15 weight percent, for example.

In some embodiments, a first nanocomposite, or a first concentrated aqueous dispersion, that includes the first polymer is melt processed with the second polymer (also referred to as an additional polymer) to form a nanocomposite (e.g., a second nanocomposite) that includes both the first and second polymers. In some such embodiments, the second polymer is not dispersible in water with or without a neutralizing agent. In some embodiments, w2 can be less than 12 weight percent and/or |wl-w2| can be as high as 15 weight percent, for example. In some embodiments, wl is greater than 12 weight percent, or greater than 13 weight percent, or greater than 14 weight percent, or greater than 15 weight percent; or in a range of 13 to 50 weight percent, or 13 to 35 weight percent, or 13 to 27 weight percent, or 14 to 22 weight percent, or 15 to 21.5 weight percent, or 15 to 21 weight percent, or 15 to 20.5 weight percent. In some such embodiments, or in other embodiments, w2 is at least 10 weight percent; or in a range of 10 weight percent to 25 weight percent, or to 21.5 weight percent, to 21 weight percent, or to 20.5 weight percent; or w2 can be in any range described for wl . For example, in some embodiments, wl is in a range of 15 to 20.5 weight percent and w2 is in a range of 10 to 20.5 weight percent or 15 to 20.5 weight percent. In some embodiments, at least one of wl and w2 is in a range of 14 to 22 weight percent or in a range of 15 to 21.5 weight percent.

In some embodiments, the first polymer includes (meth)acrylic acid monomer units at a weight percent wl and further includes ethylene monomer units, and the second polymer includes (meth)acrylic acid monomer units at a weight percent wl and further includes ethylene monomer units. In some such embodiments, wl is greater than 15 weight percent, and |wl-w2| is less than 10 weight percent.

In some embodiments, the first polymer includes (meth)acrylic acid monomer units at a weight percent wl and further includes ethylene monomer units, and the second polymer includes (meth)acrylic acid monomer units at a weight percent wl, and further includes ethylene monomer units, and further includes at least one monomer unit selected from the group consisting of n-butyl acrylate, isobutyl acrylate, isopropyl acrylate, n-propyl acrylate, ethyl acrylate, methyl acrylate, 2- ethylhexyl acrylate, iso-octyl acrylate and methyl methacrylate. In some such embodiments, wl is greater than 15 weight percent, and |wl-w2| is less than 15 weight percent, or less than 13 weight percent, or less than 12 weight percent.

In some embodiments, the first polymer is at least partially neutralized. By this it is meant that the first polymer includes a carboxylic acid group where the proton of the carboxylic acid group is replaced by a cation, such as a metal cation. Monovalent, divalent, and higher valency cations are suitable. In some embodiments, the first polymer is at least partially neutralized with metal cations, alkylammonium cations, or a combination thereof. In some embodiments, the first polymer is at least partially neutralized with sodium cations, calcium cations, potassium cations, zinc cations, lithium cations, magnesium cations, aluminum cations, or a combination thereof. In some embodiments, the first polymer is at least partially neutralized with nonmetallic cations. For example, the first polymer can be at least partially neutralized with alkylammonium cations. In some embodiments, the nanocomposite is formed from an aqueous dispersion as described further elsewhere herein. In some embodiments, in the aqueous dispersion, the first polymer is at least partially neutralized with at least one nonvolatile neutralizing agent, or at least one volatile neutralizing agent, or a combination of volatile and nonvolatile neutralizing agents. For example, in some embodiments, in the aqueous dispersion, the first polymer is at least partially neutralized with nonvolatile amine cations, volatile amine cations (e.g., cations of dimethylethanolamine or ammonium cations), or a combination of volatile and nonvolatile amine cations. The first polymer can be at least partially neutralized with a combination of different types of cations (e.g., metallic and nonmetallic cations or any combinations of cations describe herein). The first polymer can be an at least partially neutralized ionomer prior to being dispersed in the aqueous dispersion. In some embodiments, the ionomer is sufficiently neutralized that no additional neutralizing agents need to be added to the aqueous dispersion. In other embodiments, the ionomer is further at least partially neutralized by additional neutralizing agents added to the aqueous dispersion.

In some embodiments, the second polymer is at least partially neutralized. In some embodiments, each polymer of the at least one polymer, or each polymer including (meth)acrylic acid monomer units, is at least partially neutralized. The second polymer, or other polymers of the at least one polymer, can be at least partially neutralized with any cation or combination of cations described for the first polymer.

Suitable ethylene (meth)acrylic acid copolymers can be obtained from commercial sources such as PRIMACOR 5980i from Dow Chemical Company (Midland, MI), NUCREL 925 and 960 from E. I. du Pont de Nemours and Company (Wilmington, DE), ESCOR 5200 from Exxon-Mobil (Irving, TX), and AC-5180 from Honeywell (Morris Plains, NJ), for example. Suitable partially neutralized ethylene (meth)acrylic acid copolymers can be obtained from commercial sources such as, for example, SURLYN 1601, 1706, 1707, 7940, 9020, 9120, 8150 and PC-350, and HPF 1000 from E. I. du Pont de Nemours and Company (Wilmington, DE), for example.

A wide range of metal oxide nanoparticles are suitable. Examples of suitable metal oxide nanoparticles include metal oxides of silicon (silicon is considered to be a metalloid and thus is included in the list of metal oxides), titanium, aluminum, hafnium, zinc, tin, cerium, yttrium, indium, antimony or mixed metal oxides thereof. Among the more desirable metal oxide nanoparticles are those of silicon. For example, the metal oxide nanoparticles can be silica (SiCE) nanoparticles or SiOx (0 < x < 2) nanoparticles.

The size of such particles can be chosen to avoid significant visible light scattering. The surface-modified metal oxide nanoparticles can be particles having a (e.g. unassociated) primary particle size or associated particle size of greater than 1 nm (nanometers) and less than 200 nm. In some embodiments, the particle size is greater than 4 nm, greater than 5 nm, greater than 10 nm, or greater than 20 nm. In some embodiments, the particle size is less than 190 nm, less than 150 nm, less than 100 nm, less than 75 nm, or less than 50 nm. Typically, the nanoparticles have a size ranging from 4-190 nm, 4-100 nm, 4-75 nm, 10-50 nm, or 20-50 nm. In embodiments where a low optical haze is desired, a particle size of less than 100 nm, less than 75 nm, or less than 50 nm is typically preferred. It is typically desirable that the nanoparticles are unassociated. Particle size can be measured in a wide variety of ways such as by transmission electron microscopy (TEM). Typically, commercially obtained metal oxide nanoparticles are supplied with a listed particle size or particle size range.

The nanoparticles are surface modified to improve compatibility with the polymer matrix material and to keep the nanoparticles non-associated, non-agglomerated, non-aggregated, or a combination thereof. The surface modification used to generate the surface-modified nanoparticles includes at least one acid-functional silane surface modifying agent. The acid- fiinctional silane surface modifying agent can have the general Formula 1 :

Formula 1 where R1 is a Ci to Cio alkoxy group; and R2 and R3 are independently selected from the group consisting of Ci to Cio alkyl and Ci to Cio alkoxy groups. The group A is a linker group selected from the group consisting of Ci to Cio alkylene or arylene groups, Ci to Cio aralkylene groups, C₂ to Ci₆ heteroalkylene or heteroarylene groups, and C₂ to Ci₆ amide containing groups. Amide containing groups include groups of the type -(CH₂) -NH-(CO)-(CH₂)_b-; where a and b are integers of 1 or greater, and (CO) is a carbonyl group C=0. In some embodiments, A is an alkylene group with 1-3 carbon atoms.

While acid-functional silanes may be commercially available, one aspect of the current disclosure includes the synthesis of the carboxylic acid-functional silanes of Formula 1. In addition to the synthetic process presented below, an anhydride -functional silane such as (3- triethoxysilyl)propylsuccinic anhydride, which can be obtained from commercial sources such as Gelest, Inc. (Morrisville, PA), could be used to prepare the acid-functional silane surface modification agent.

In some embodiments, a solution is prepared of an organic acid anhydride dissolved in a first organic solvent. A second solution is prepared of an aminosilane in a second organic solvent. The two solutions are combined. The combined solution is stirred continuously at a suitable temperature and duration to synthesize a carboxylic acid-functional silane of Formula 1. In other embodiments, a solution is prepared of an organic acid anhydride dissolved in an organic solvent. An aminosilane is dissolved in the organic acid anhydride solution. The solution containing the organic acid anhydride and aminosilane is stirred continuously at a suitable temperature and duration to synthesize a carboxylic acid silane of Formula 1. The first and second organic solvents may be the same or different. In the case where the first and second organic solvent are different, then the first and second organic solvents are miscible. Both first and second organic solvents are miscible with water.

Suitable organic acid anhydrides include succinic anhydride (3,4-dihdrofuran-2,5-dione), tetrahydrofuran-2,5-dione, 3-alkyltetrahydrofuran-2,5-diones such as 3-methyltetrahydrofuran-2,5- dione and 3-ethyltetrahydrofuran-2,5-dione, tetrahydropyran-2,6-dione, 3-alkyltetrahydropyran- 2,6-diones such as 3-methyltetrahydropyran-2,6-dione and 3-ethyltetrahydropyran-2,6-dione 4- alkyltetrahydropyran-2,6-diones such as 4-methyltetrahydropyran-2,6-dione, 4- ethyltetrahydropyran-2,6-dione, and 4,4’-methyltetrahydropyran-2,6-dione, oxepane-2,7-dione. Suitable organic acid anhydrides can be obtained from commercial sources such as Alfa Aesar (Ward Hill, MA) and Millipore Sigma (Burlington, MA). Succinic anhydride is a particularly suitable organic acid anhydride.

Suitable aminosilanes include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, p-aminophenyltrimethoxysilane, p-aminophenyltriethoxysilane, N- phenylaminopropyltrimethoxysilane, N-phenylaminopropyltriethoxysilane, n- butylaminopropyltrimethoxysilane, n-butylaminopropyltriethoxysilane, 3-(N- allylamino)propyltrimethoxysilane, (N,N-diethyl-3-aminopropyl)trimethoxysilane, and (N,N- diethyl-3 -aminopropyltriethoxysilane. Suitable aminosilanes can be obtained from commercial sources such as Gelest, Inc. (Morrisville, PA), Alfa Aesar (Ward Hill, MA), Millipore Sigma (Burlington, MA), and Momentive Performance Materials (Waterford, NY). A particularly suitable aminosilane is aminopropyltrimethoxysilane.

A wide variety of organic solvents can be used. Suitable organic solvents include N,N- dimethylformamide (DMF) which can be obtained from commercial sources such as OmniSolv (Billerica, MA).

In some embodiments, the surface -modified metal oxide nanoparticles are prepared by combining an aqueous nanodispersion of surface unmodified metal oxide nanoparticles of basic pH and a carboxylic acid-functional silane surface modifying agent, reacting the carboxylic acid- functional silane surface agent with the metal oxide nanoparticle surface resulting in an aqueous nanodispersion of surface-modified metal oxide nanoparticles where the nanoparticles are surface modified with a carboxylic acid. This can be carried out in a variety of ways. In some embodiments, an aqueous nanodispersion of surface unmodified metal oxide nanoparticles is combined with a solution of a carboxylic acid silane of Formula 1 in an organic solvent. In other embodiments, an aqueous nanodispersion of surface unmodified metal oxide nanoparticles is combined with a base and a solution of a carboxylic acid silane of Formula 1 in an organic solvent. In other embodiments, an aqueous nanodispersion of surface unmodified metal oxide nanoparticles is combined with a carboxylic acid silane of Formula 1. Generally, the carboxylic acid silane of Formula 1 is added at a concentration sufficient to modify 10 to 100% of the total metal oxide nanoparticle surface area in the nanodispersion. As was mentioned above, the metal oxide nanoparticles may have a variety of sizes. Typically, the average particle size is greater than 1 nm and less than 200 nm. In some embodiments, the particle size is greater than 4 nm, greater than 5 nm, greater than 10 nm, or greater than 20 nm. In some embodiments, the particle size is less than 190 nm, less than 150 nm, less than 100 nm, less than 75 nm, or less than 50 nm. Typically, the nanoparticles have a size ranging from 4-190 nm, 4-100 nm, 4-75 nm, 10-50 nm, or 20-50 nm.

For low haze, typical preferred ranges are from 4-100 nm, 4-75 nm, or 4-50 nm. In some cases, a base may be added to the aqueous nanodispersion of surface unmodified metal oxide nanoparticles to maintain the pH in the desired range since the addition of the carboxylic acid silane solution of Formula 1 will tend to lower pH. In some cases, the organic solvent is removed from of the solution of carboxylic acid silane in organic solvent prior to combining the carboxylic acid silane and aqueous nanodispersion of surface unmodified metal oxide nanoparticles.

Aqueous nanodispersions of unmodified metal oxide nanoparticles may be prepared or, in some embodiments, aqueous nanodispersions of unmodified metal oxide nanoparticles may be obtained commercially. Suitable surface unmodified metal oxide nanoparticles include aqueous nanodispersions commercially available from Nalco Chemical Company (Naperville, IL) under the trade designation ‘Nalco Colloidal Silicas” such as products NALCO 2326, 1130, DVSZN002,

1142, 2327, 1050, DVSZN004, 1060, and 2329K; from Nissan Chemical America Corporation (Houston, TX) under the tradename SNOWTEX such as products ST-NXS, ST-XS, ST-S, ST-30, ST-40, ST-N40, ST-50, ST-XL, and ST-YL; from Nyacol Nano Technologies, Inc. (Ashland, MA) such as NEXSIL 5, 6, 12, 20, 85-40, 20A, 20K-30, and 20NH4. In some cases, the surface unmodified metal oxide nanoparticles may be dispersed in an aqueous solution with a pH in the range 8-12.

Suitable bases include ammonium hydroxide which can be obtained from commercial sources such as Millipore Sigma (Burlington, MA).

Typically, the surface-modified metal oxide nanoparticles are used as a nanodispersion, and the particles are not isolated. Another aspect of the present disclosure involves the preparation of nanodispersions of surface-modified metal oxide nanoparticles without precipitation, gelation, agglomeration, or aggregation, where the metal oxide nanoparticles are surface modified with a carboxylic acid silane of Formula 1.

In some embodiments, an aqueous nanodispersion of surface unmodified metal oxide nanoparticles and solution of a carboxylic acid silane of Formula 1 in an organic solvent are combined in a reactor and heated at a suitable temperature and duration to react the carboxylic acid silane of Formula 1 with the surface of the metal oxide nanoparticles. In other embodiments, an aqueous nanodispersion of surface-unmodified metal oxide nanoparticles, base, and a solution of carboxylic acid silane of Formula 1 in an organic solvent are combined in a reactor and heated at a suitable temperature and duration to react the carboxylic acid silane of Formula 1 with the surface of the metal oxide nanoparticles. In some embodiments, a solvent exchange is performed on the aqueous nanodispersion of surface-modified metal oxide nanoparticles and organic solvent to remove the organic solvent. In some embodiments, the reactor is open, under reflux conditions, and in other embodiments the reactor is closed and under pressure. In some embodiments, the reactor is glass and in some embodiments the reactor is stainless steel. A wide range of loadings of the surface-modified metal oxide nanoparticles in the nanocomposite are suitable. Typically, the nanocomposite includes at least 1% by weight of surface-modified metal oxide nanoparticles and no more than 70% by weight of surface -modified metal oxide nanoparticles. In some embodiments, the surface -modified metal oxide nanoparticle concentration is from 5-60% by weight, or from 10-50% by weight.

Additional additives may include flame retardants, thermal stabilizers, anti-slip agents, neutralizing agents, UV absorbers, light stabilizers, antioxidants, crosslinking agents, mold release agents, catalysts, colorants, anti-stat agents, defoamers, plasticizers, and other processing aids, for example.

An aqueous dispersion can be used in forming the nanocomposite or ionomer layers without nanoparticles. It has been unexpectedly found that high molecular weight (meth)acrylic polymer(s) (e.g., number average molecular weight of at least 10000 grams/mole) can be dispersed in water (e.g., with suitable neutralizing agents) and that the resulting aqueous dispersion is useful in making a nanocomposite, for example, with desired mechanical and optical properties. In some embodiments, an aqueous dispersion includes water; at least one polymer dispersed in the water; and metal oxide nanoparticles dispersed in the water. The at least one polymer includes a first polymer including (meth)acrylic acid monomer units and optionally having a number average molecular weight of at least 10000 grams/mole. The first polymer is at least partially neutralized. The metal oxide nanoparticles are surface modified with a carboxylic acid silane surface modifying agent. The carboxylic acid silane surface modifying agent can be or include a carboxylic acid silane of Formula 1, described elsewhere herein. The metal oxide nanoparticles can optionally be omitted when an ionomer layer not including nanoparticles is desired.

The layer 115 (e.g., transparent elastic ionomer layer) can be an elastic ionomer of one polymer, an elastic ionomer blend of two or more polymers or an elastic ionomer nanocomposite including metal oxide nanoparticles in one elastic ionomer polymer or two or more elastic ionomer polymer layers. In some cases, the layer 115 may include a multilayer structure (not shown in figures) with different elastic ionomer and/or elastic ionomer nanocomposite layers. The layer 115 may have a thickness in a range of 5-125 microns, 5-70 microns, 5-50 microns or from 5-30 microns. As with layer 110, the layer 115 is preferably capable of stretching within an elastic range, so that permanent deformation does not occur. The proportional limit for a material is defined as the maximum stress at which the stress is proportional to strain (Hooke's law). The elastic limit is the minimum stress at which permanent deformation can be measured. The elastic ionomer layer may have a strain at the elastic limit that is 10% greater than the strain at the proportional limit, 20% greater than the strain at the proportional limit, 50% greater than the strain at the proportional limit, or 100% greater than the strain at the proportional limit. Again, the graph shown in FIG. 6 illustrates this concept.

Compositions suitable for use in layer 115 include those that include at least one (meth)acrylic polymer (e.g., one (meth)acrylic polymer or two or more miscible (meth)acrylic polymers) and may optionally include surface-modified metal oxide nanoparticles, where the surface-modified metal oxide nanoparticles are surface modified with an acid-functional silane surface modifying agent, and where the (meth)acrylic polymer(s) are at least partially neutralized. The elastic ionomers may be melt processable into films that are optically transparent. By melt processable it is meant that the elastic ionomers are able to be melt processed, that is to say that the polymer or polymer nanocomposite can be heated and made to flow without causing degradation. Melt processable does not mean that the elastic ionomer has been melt processed and in no way indicates a processing step. The elastic ionomers may also be made by coating processes from aqueous dispersions on to a substrate such that the film can be removed from the substrate or transferred to another layer like thin glass layer 120.

A wide range of (meth)acrylic polymers are suitable for use in layer 115. The (meth)acrylic polymer(s) include (meth)acrylic acid monomers units (i.e., acrylic acid monomer units, methacrylic acid monomer units, or both acrylic acid monomer units and methacrylic acid monomer units). In some embodiments, the (meth)acrylic polymers are homopolymers of acrylic acid or methacrylic acid. In other embodiments, the (meth)acrylic polymers are copolymers of at least one (meth)acrylic monomer unit that is acid-functional and at least one monomer that is a (meth)acrylate that is not acid-functional. Additionally, the (meth)acrylic polymers can contain other non-(meth)acrylate monomers that are co-polymerizable with the (meth)acrylic and (meth)acrylate monomers. The copolymers can be formed by the polymerization or copolymerization using free radical polymerization techniques. In some embodiments, the at least one (meth)acrylic polymer includes a copolymer containing (meth)acrylic acid and at least one co monomer. A wide range of co-monomers are suitable. Suitable co-monomers include ethylene, propylene, alkyl(meth)acrylates, aryl(meth)acrylates, alkaryl(meth)acrylates, acrylonitrile, and carbon monoxide. Detailed description of the suitable compositions for layer 115 are detailed in the description of layer 110, and further supported by the experimental examples.

The layer 130, which may be referred to as an energy dissipation layer, may have a glass transition temperature of 27 degrees Celsius or less, or less than 10 degrees Celsius, or less than 5 degrees Celsius. The energy dissipation layer may have a low glass transition temperature, such as 5 degrees Celsius less, or zero degrees Celsius or less, or -5 degrees Celsius or less, or -10 degrees Celsius or less or in a range from -40 to 5 degrees Celsius, or in a range from -30 to 5 degrees Celsius, or in a range from -20 to 5 degrees Celsius, or in a range from -15 to 5 degrees Celsius, or in a range from -10 to 5 degrees Celsius, or in a range from -5 to 5 degrees Celsius. Glass transition temperature is herein characterized using Dynamic Mechanical Analysis using E".

The energy dissipation layer may have a Tan Delta peak value of 0.5 or greater, or 0.8 or greater, or 1.0 or greater, or 1.2 or greater, or from 0.5 to 2.5, or from 1 to 2.5, or from 1 to 2. The energy dissipation layer or layers have a Young’s Modulus (E') greater than 0.9MPa over the temperature range -40 degrees Celsius to 70 degrees Celsius. The energy dissipation layer would not be referred to as a pressure sensitive adhesive.

The energy dissipation layer may be formed of a plurality of layers, and at least two of these layers having a different glass transition temperature value. These layers may have a different glass transition temperature value by at least 2 degrees Celsius, or at least 5 degrees Celsius, or at least 10 degrees Celsius, for example. In some cases, the energy dissipation layer peak Tan Delta values may occur at different frequencies at a specified temperature.

The energy dissipation layer may have a thickness of at least 20 micrometers or at least 30 micrometers or at least 50 micrometers. The energy dissipation layer may have a thickness in a range from 20 to 200 micrometers, or 50 to 150 micrometers, or from 75 to 150 micrometers. The thickness of the energy dissipation layer may be a balance between being thick enough to provide the desired protection to the display and thin enough to provide the dynamic performance requirements and/or reduced thickness for industrial design considerations.

The layer 130 may be a cross-linked polymer layer formed of a cross-linked polyurethane material or a cross-linked polyurethane acrylate material. The layer 130 may be designed to have beneficial properties with respect to impact resistance and the ability to survive dynamic folding at low temperature conditions, for example.

A transparent cross-linked polyurethane layer preferably includes chemically or covalently crosslinked materials derived from step growth polymerization of isocyanate and polyol oligomers. Selection of reactant isocyanates and polyols may modify the glass transition temperature of the resulting cured polyurethane.

The cross-linked polyurethane layer may be coated onto the transparent polymeric or glass substrate layer (that may be primed) and then be cured or cross-linked to form a thermoset polyurethane layer. Alternatively, the cross-linked polyurethane layer could be produced as a film that is then laminated to the transparent glass layer in a subsequent process step. Such lamination could be assisted with heat, vacuum, or through the use of an adhesive or combination thereof.

Polyurethane is a polymer composed of organic units joined by carbamate (urethane) links. The polyurethanes described herein are thermosetting polymers that do not melt when heated. Polyurethane polymers may be formed by reacting a di- or polyisocyanate with a polyol. Both the isocyanates and polyols used to make polyurethanes contain on average two or more functional groups per molecule. The polyurethanes described herein may be derived from components that have functionality greater than 2.4 or 2.5.

For the purposes of processing, the isocyanate and polyol components can be mixed just prior to application of the material to the substrate used for making the display film. Generally, the average functionality of the isocyanates used to make the energy dissipation layer is less than 3.5 (i.e. an average of 3.5 isocyanate functional groups per molecule) or 3 or less. The ideal cured material exhibits stable material properties with respect to the display film use in application, i.e. the energy dissipation layer does not exhibit appreciable flow but is stable enough to provide durability in physical testing in folding devices, for example low temperature dynamic folding performance.

In some cases, the layer 130 may also contain inorganic nanoparticles, either functional that are chemically reacted to the matrix or non-functional that are not reacted to the energy dissipation layer matrix resin. The incorporation of nanoparticles may provide beneficial properties related to impact resistance and energy dissipation from impact events.

A wide variety of polyisocyanates may be used to from the cross-linked polyurethane layer. The term polyisocyanate includes isocyanate-functional materials that generally include at least 2 terminal isocyanate groups. Polyisocyanates include diisocyanates (materials with 2 terminal isocyanate groups) and higher polyisocyanates such as triisocyanates (materials with 3 terminal isocyanate groups), tetraisocyanates (materials with 4 terminal isocyanate groups), and the like. Typically, the reaction mixture contains at least one higher isocyanate if a difunctional polyol is used. Higher isocyanates are particularly useful for forming crosslinked polyurethane polymers. Diisocyanates may be generally described by the structure OCN — Z — NCO, where the Z group may be an aliphatic group, an aromatic group, or a group containing a combination of aromatic and aliphatic groups. In some embodiments, it is preferable to use an aliphatic isocyanate, such as isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4’-diisocyanate (H12MDI), dimeryl diisocyanate (DDI), pentamethylenediisocyanate (PDI), hexamethylenedisocyanate (HDI), and oligomers, derivatives, or combinations of these isocyanates. It may be preferable to include the use of alkyl and aromatic monoisocyanates, such as phenyl isocyanate and octyl isocyanate.

Higher functional polyisocyanates are particularly useful, such as triisocyanates, to form a crosslinked polyurethane polymer layer. Triisocyanates include, but are not limited to, polyfunctional isocyanates, such as those produced from isocyanurates, biurets, allophanates, uretdiones, iminooxadiazinediones, carbodiimides, uretoneimines adducts, and the like. Some commercially available polyisocyanates include portions of the DESMODUR and MONDUR series from Bayer Corporation, Pittsburgh, Pa., and the PAPI series from Dow Plastics, a business group of the Dow Chemical Company, Midland, Mich. In some embodiments, isocyanates based on HDI are preferred to provide a glass transition temperature below 10 °C. Monomeric HDI can be used, but in some embodiments, it is preferred to use oligomers of HDI. Oligomeric HDI can reduce the vapor pressure of the isocyanate to allow safer handling and may provide functionalities greater than 2.0 to provide chemical crosslinking of the energy dissipation layer material. The HDI oligomers can contain functional groups including isocyanurates, biurets, allophanates, uretdiones, iminooxadiazinediones, carbodiimides, or uretoneimines. In some embodiments, prepolymers derived from HDI and polyols can be used. In some embodiments, it is preferred to use HDI oligomers containing uretdione functionality and isocyanurate functionality. Particularly useful higher isocyanates include those available from Bayer Corporation under the trade designations DESMODURN3300A, Desmodur N3400, and MONDUR 489. An oligomer containing both uretdione and isocyanurate groups can be obtained under the trade name DESMODUR N3400, and an oligomer containing isocyanurate groups can be obtained under the tradename DESMODUR N3300. One particularly suitable aliphatic polyisocyanate is DESMODUR N3300A.

A wide variety of polyols may be used to form the cross-linked polyurethane layer. The term polyol includes hydroxyl-functional materials that generally include at least 2 terminal hydroxyl groups. Polyols include diols (materials with 2 terminal hydroxyl groups) and higher polyols such as triols (materials with 3 terminal hydroxyl groups), tetraols (materials with 4 terminal hydroxyl groups), and the like. Typically, the reaction mixture contains at least some diol and may also contain higher polyols. Higher polyols are particularly useful for forming crosslinked polyurethane polymers. Diols may be generally described by the structure HO — B — OH, where the B group may be an aliphatic group, an aromatic group, or a group containing a combination of aromatic and aliphatic groups, and the B group may contain a variety of linkages or functional groups, including additional terminal hydroxyl groups.

In some embodiments, the polyol is an oligomeric polyether such as polyethylene glycol, polypropylene glycol, or polytetramethylene ether glycol. In some embodiments, aliphatic polyester polyols are particularly useful. Useful polyester polyols are linear and non-linear polyester polyols including, for example, polyethylene adipate, polypropylene adipate, polybutylene adipate, polyhexamethylene adipate, polyneopentyl adipate, polycyclohexanedimethyl adipate, polydiethylene glycol adipate, polybutylene succinate, polyhexamethylene sebacate, polyhexamethylene dodecanedioate, and poly e-caprolactone and copolymers of these polyesters. Particularly useful are aliphatic polyester polyols available from King Industries, Norwalk, Conn., under the trade name “K-FLEX” such as K-FLEX 188 or K- FLEX A308. In some embodiments, the polyester polyol can include polyesters derived from cyclohexanedimethanol and aliphatic diacids. In some embodiments, it is preferred to use polyester polyols that are liquids at room temperature to facilitate mixing and coating at ambient temperature. In some embodiments, it is preferred to use polyester polyols that produce a sharp tan delta signal in DMA testing, such as polyesters based on cyclohexanedimethanol and neopentyl glycol.

The (e.g., energy dissipation) layer 130 may be derived from an oligomeric polyol. In some embodiments, the polyol component may include a chain extender with a molecular weight of less than 200 g/mol. In some embodiments, the polyol component comprises only oligomeric polyol and is substantially free of chain extenders.

To produce an energy dissipation layer with a glass transition temperature below 10 °C, it can be preferable to limit the amount of the isocyanate component. In some embodiments using HDI-derived isocyanates, it can be preferable to use less than 40 wt% isocyanate component based on the total core layer composition, or less than 38 wt%, or less than 35 wt%. In some embodiments, it is preferable to use an isocyanate component containing uretdione groups. When uretdione groups are included, it can be preferable to use an excess of hydroxyl functional groups relative to isocyanate groups. The excess hydroxyl groups can react with the uretdione groups to form allophanate groups to provide cure and chemical crosslinking. In some embodiments, it is preferable to include only a single polyol component to produce a narrow tan delta peak. In some embodiments, it is preferable to use a polyol component and an isocyanate component that are miscible with each other at room temperature.

The cross-linked polyurethane layer is preferably prepared such that the combined average functionality of the polyol component and the isocyanate component is greater than 2.4 or 2.5. In some cases, both the polyol and isocyanate each have an average functionality greater than 2.4 or 2.5. In some cases, only the isocyanate has an average functionality greater than 2.4 or 2.5, and the polyol component has an average functionality of about 2.0. In some cases, only the polyol has an average functionality greater than 2.4 or 2.5, and the isocyanate component has an average functionality of about 2.0.

The isocyanate index is defined as the molar content of isocyanate functional groups divided by the hydroxyl functional groups. The crosslinked polyurethane is preferably prepared with an isocyanate index between 0.6 and 1.2 or between 0.7 and 1.1 or between 0.75 and 1.05.

In some cases, the isocyanate component can contain uretdione functionality. Under appropriate conditions, excess hydroxyl groups can react with the uretdione functional groups for form an allophanate group that further enhances crosslinking. When uretdione functional groups are present, an alternative index can be calculated by dividing the sum of the moles of isocyanate functional groups and uretdione functional groups by the moles hydroxyl functional groups. In some embodiments, it is preferable that this alternative index be between 0.8 and 1.2 or between 0.85 and 1.1 or between 0.90 and 1.0.

The degree of crosslinking of the polyurethane energy dissipation layer can be related to the amount of gel content in the urethane. The gel content can be measured by submerging a sample of urethane in a solvent, such as refluxing THF, to extract the non-gel component. The gel content can then be measured gravimetrically by dividing the remaining dried weight after extraction by the weight of sample before extraction. In some embodiments, the core layer can have a gel content of greater than 80%, or greater than 90%, or greater than 95%.

The reactive mixture used to form the cross-linked polyurethane layer also contains a catalyst. The catalyst facilitates the step-growth reaction between the polyol and the polyisocyanate. Conventional catalysts generally recognized for use in the polymerization of urethanes may be suitable for use with the present disclosure. For example, aluminum -based, bismuth-based, tin-based, vanadium-based, zinc-based, or zirconium-based catalysts may be used. Tin-based catalysts are particularly useful. Tin-based catalysts have been found to significantly reduce the amount of outgassing present in the polyurethane. Most desirable are dibutyltin compounds, such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetylacetonate, dibutyltin dimercaptide, dibutyltin dioctoate, dibutyltin dimaleate, dibutyltin acetonylacetonate, and dibutyltin oxide. In particular, the dibutyltin dilaurate catalyst DABCO T-12, commercially available from Air Products and Chemicals, Inc., Allentown, Pa. is particularly suitable. The catalyst is generally included at levels of at least 200 ppm or even 300 ppm or greater.

In some embodiments, it is desirable for the glass transition temperature of the cross- linked polyurethane layer (or core layer) be 10 degrees Celsius or less, or 5 degrees Celsius or less, or 0 degrees Celsius or less, or -5 degrees Celsius or less, or -10 degrees Celsius or less, or in a range from -40 to 5 degrees Celsius, or in a range from -30 to 5 degrees Celsius, or in a range from -20 to 5 degrees Celsius, or in a range from -15 to 5 degrees Celsius. In some cases, it is also desirable that the crosslinked material have a high Tan Delta (>0.5, >0.8, >1.0 or greater than 1.2).

The transparent cross-linked polyurethane layer may have a cross-link density in a range from 0.1 to 1.0 mol/kg or from 0.2 to 0.9 mol/kg or from 0.37 to 0.74 mol/kg. The crosslink density of the cured polyurethane coatings is calculated using the method described in Macromolecules, Vol. 9, No. 2, pages 206-211 (1976). To implement this model, integral values for chemical functionality are required. DESMODURN3300 is reported to have an average functionality of 3.5 and an isocyanate equivalent weight of 193 g/equiv. This material was represented in the mathematical model as a mixture of 47.5 wt% HDI trimer (168.2 g/equiv.), 25.0 wt% HDI tetramer (210.2 g/equiv.), and 27.5 wt% of HDI pentamer (235.5 g/equiv.). This mixture yields an average equivalent weight of 193 g/equiv. and an average functionality of 3.5. Desmodur N3400 is reported to have an average functionality 2.5 and an equivalent weight of 193, and it is reported to be blend of the HDI isocyanurate trimer and HDI uretdione dimer. This material was represented in the mathematical model as a mixture of 19 wt% HDI isocyanurate trimer, 33 wt% HDI uretdione dimer, and 10 wt% of HDI uretdione trimer and 38 wt% of HDI tetramer having one isocyanurate group and one uretdione group. In the mathematical model, the functionality was determined by the sum the isocyanate groups and the uretdione groups in the cases where there was an excess of hydroxyl groups relative to the sum of the isocyanate and uretdione groups.

A cross-linked polyurethane containing energy dissipation layer or layers may be formed by free radical polymerization of multifunctional urethane acrylate oligomers. The urethane acrylate oligomer may be mixed with other low molecular weight monofunctional and/or multifunctional acrylates to modify the pre-cured viscosity of the resin for the purposes of processing. Generally, the average functionality of the multifunctional acrylate used in the energy dissipation layer prior to cure is less than 3 (i.e. 3 functional acrylate functional groups per molecule) or can be 2 or less. The cured (or crosslinked) material may exhibit stable material properties with respect to the display fdm use in application, that is, the energy dissipation layer may, in some embodiments, not exhibit appreciable flow.

The transparent polyurethane acrylate material may be coated onto the transparent polymeric or glass substrate layer (that may be primed) and then be cured or cross-linked to form a thermoset or cross-linked polyurethane acrylate layer. The polyurethane acrylates described herein are thermosetting polymers that do not melt when heated, according to some embodiments.

Urethane acrylate oligomers can be comprised of a wide variety of urethane materials with acrylate or methacrylate reactive groups. Urethane acrylate oligomers are commercially available from vendors such as, for example, Sartomer of Exton, Pennsylvania (a subsidiary of Arkema) and Allnex (Ebecryl Brand name).

Examples of commercially available aliphatic urethane oligomers include but are not limited to CN9002, CN9004 and CN3211 available from Sartomer Company and those sold under the Ebecryl brand name.

In some embodiments, a multilayer fdm includes an additional layer 130 disposed on the glass layer 120 opposite the nanocomposite layer 110, where the additional layer 130 includes a cross-linked polyurethane or a cross-linked polyurethane acrylate. In some embodiments, a multilayer fdm includes a first additional layer 115 disposed on the glass layer 120 opposite the nanocomposite layer 110, where the first additional layer 115 includes at least one polymer, where the at least one polymer of the first additional layer includes a first polymer including (meth)acrylic acid monomer units. In some embodiments, the first additional layer 115 further comprises surface-modified metal oxide nanoparticles dispersed in the at least one polymer of the first additional layer 115. In some embodiments, the multilayer film further includes a second additional layer 130 disposed on the first additional layer 115 with the first additional layer 115 being between the glass layer 120 and the second additional layer 130. The second additional layer 130 can include a cross-linked polyurethane or a cross-linked polyurethane acrylate.

In some embodiments, the substrate 150 is or includes a polymeric substrate. The substrate may be formed of any useful polymeric material, for example, that provides desired mechanical properties (such as dimensional stability) and optical properties (such as light transmission and clarity). In some embodiments, the substrate 150 includes one or more of polyester (e.g., polyethylene terephthalate, polyethylene naphthalate), polycarbonate, polymethylmethacrylate, cyclic olefin polymer, cyclic olefin copolymer, or polyimide.

In some embodiments, the substrate 150 is or includes a nominally colorless polyimide. Nominally colorless polyimide can be formed via chemistry or via nanoparticle incorporation. Some exemplary nominally colorless polyimides formed via chemistry are described in WO 2014/092422. Some exemplary nominally colorless polyimides formed via nanoparticle incorporation are described in Journal of Industrial and Engineering Chemistry 28 (2015) 16-27. Useful nominally colorless polyimide films may have glass transition temperatures greater 220 degrees Celsius or greater than 250 degrees Celsius or even greater than 300 degrees Celsius and tensile moduli greater than 6GPa, or greater than 6.5GPa or even Greater than 7GPa. These high modulus polymers exhibit excellent resistance to plastic deformation. In some cases, nominally colorless that the b* value for the film is less no more than 5. In some preferred cases, b* is no more than 4, or no more than 3, or no more than 2.

The substrate 150 may be primed or treated to impart some desired property to one or more of its surfaces. For example, the substrate 150 may be primed to improve adhesion of the elastic ionomer nanocomposite layer 110 to the substrate 110. Additionally, the substrate 150 may be primed or treated to enhance adhesion between the hardcoat 170 and the substrate 150. Examples of such treatments include corona, flame, plasma and chemical treatments such as, acrylate or silane treatments.

The hardcoat layer 170 typically has a thickness of less than 50 micrometers or less than 40 micrometers. The hardcoat layer 170 may have a thickness in a range from 2 to 30 micrometers, or from 2 to 15 micrometers, or from 3 to 10 micrometers. The hardcoat layer may include nanoparticles.

Suitable hardcoats can include a variety of cured polymeric materials having inorganic nanoparticles. These hardcoats can include but are not limited to (meth)acrylic based hardcoats, siloxane hardcoats, polyurethane hardcoats and the like. One preferable class of hardcoats include acrylic hardcoats that include inorganic nanoparticles. Such hardcoats can have a polymerizable resin composition including mixtures of multifunctional (meth)acrylic monomers, oligomers, and polymers, where the individual resins can be monofunctional, difunctional, trifunctional, tetrafunctional or have even higher functionality.

In preferred cases, the polymerizable (meth)acrylate components of the resin system are chosen such that when polymerized, the hardcoat contains little to no free (meth)acrylic monomers.

Details of suitable acrylic hardcoats can be found in International Appl. Pub. No. WO 2019/111207 (Condo et al.) and in U.S. Pat. Appl. Nos. 62/845541; 62/845558; and 62/845533.

A low surface energy coating 105 may be applied to the surface of the nanocomposite layer 110 or to the hardcoat layer 170 Such layers can provide a low coefficient of friction coating 105 to provide improved lubricity and tactile feel of the surface.

They also can impart water and oil repellency, easy to clean properties to the surface because of the highly fluorinated surface. Such coating layers can be created for example by application of fluorosilane coatings to the surface. The coatings can be applied from solution in coating processes, spray processes, or by physical vapor deposition processes. The layers typically have thicknesses in the range of 1-50 nm and result in no negative change in optical properties. In some cases, the fluorosilane can be added to the hardcoat solution during coating and it is expressed to the surface of the hardcoat layer. Examples of suitable fluorosilane coatings are OPTOOL DSX-E and OPTOOL DAC-HP available for Daiken Chemical Europe GmbH (Dusseldorf, Germany) and NOVEC Electronic grade coatings available from 3M Company (St. Paul, MN) one particular solution being NOVEC 2202. The surface of the layers may be treated prior to coating to improve adhesion. Some examples of treatment can be plasma cleaning of the surface, atmospheric plasma activation of the surfaces, or plasma etching of the surface and deposition of a thin glass like layer designed to have chemical bonding to the fluorosilane. Examples of plasma etching processes may be found in U.S. Pat. Appl. Pub. No. 2010/0165276 (David et al.). In some embodiments, a layer (e.g., the coating 105 having a surface energy less than 35 mN/m, or less than 30 mN/m, or less than 25 mN/m is disposed on the nanocomposite layer 110 opposite the glass layer 120 In some embodiments, a layer (e.g., the coating 105 layer having a static water contact angle of at least 100 degrees, or at least 110 degrees is disposed on the nanocomposite layer 110 opposite the glass layer 120 A static water contact angle Q is schematically illustrated in FIG. 1. FIG. 7 is a schematic diagram side elevation view of an illustrative multilayer fdm 100 on an optical display 160 forming an article 700. A coupling layer 140 fixes the film 100 to the optical display 160.

FIG. 8 is a schematic diagram side elevation view of an illustrative multilayer film 200 on an optical display 160 forming an article 800. A coupling layer 140 fixes the display film 200 to the optical display 160

FIG. 9 is a schematic diagram side elevation view of an illustrative multilayer film 300 on an optical display 160 forming an article 900. A coupling layer 140 fixes the multilayer film 300 to the optical display 160.

FIG. 10 is a schematic diagram side elevation view of an illustrative multilayer film 400 on an optical display 160 forming an article 1000. A coupling layer 140 fixes the multilayer film 400 to the optical display 160.

FIG. 11 is a schematic diagram side elevation view of an illustrative multilayer film 500 on an optical display 160 forming an article 1100. A coupling layer 140 fixes the multilayer film 500 to the optical display 160.

As previously described the multilayer films 100, 200, 300, 400 and 500 in FIGS. 7-11 may include additional elements and layers that are not shown.

For the purposes of the following description of the coupling layer 140, multilayer film 100 will be used, but the coupling layer may be disposed on any of the multilayer film constructions described herein.

A coupling layer 140 adheres the display film 100 to the optical display 160. The coupling layer 140 may be a pressure sensitive adhesive. In some cases, the coupling layer 140 permanently fixes the multilayer film 100 to the optical display 160. In other cases, the multilayer film and coupling layer 140 can be removed/debonded/repositioned, relative to the optical display 160, with the application of heat or mechanical force such that the display film is replaceable or repositionable by the consumer.

The coupling layer may include acrylate, silicone, silicone polyoxamide, silicone polyurea, polyolefin, polyester, polyurethane or polyisobutylene or mixtures thereof as long as the coupling layer has suitable optical properties in terms of low haze, high transmission and low yellow index. In some cases, the coupling layer may be an optically clear adhesive or pressure sensitive adhesive.

The coupling layer 140 may have a shear modulus (G’) of 300 kPa or less, or 200 kPa or less, or 100 kPa or less or 50 kPa or less over a temperature range for example -40°C to 70°C, or from -40°C to 50°C, or from -30°C to 50°C, or from -20°C to 50°C. The rheological properties of the material can be measured using a parallel plate rheometer to probe the shear modulus as a function of temperature as well as to determine the glass transition temperature (Tg) of the material. This test can be done by using an 8 mm diameter by about 1 mm thick disk of the coupling layer material and placing it between the probes of a DHR parallel plate rheometer (TA Instruments, New Castle, DE). A temperature scan can be performed, for example, by ramping from -45°C to 50°C at 3°C/min. During this ramp, the sample is oscillated at a frequency of 1 Hz and a strain of approximately 0.4%. The shear moduli (G' and G") are recorded at selected key temperatures. The Tg of the material can be determined as the peak in the tan delta vs. temperature profde. To ensure sufficient compliance of the coupling material over the typical range of use temperatures, it is preferred to have the shear storage modulus (G') below about 2 MPa over the entire temperature range from about -20°C to about 40°C when measured using the test described above

A release liner or premask layer (not shown) may be disposed on the coupling layer 140. The release liner may be easily removed for application to an optical display or to reveal the multilayer film, before placement onto an optical display 160. The removable or release liner (or premask layer) may provide transport protection to the underlying multilayer film and optional coupling layer 140. The removable liner may be layer or film that has a low surface energy to allow clean removal of the liner from the multilayer film 100 and optional coupling layer 140. The removable liner may be a layer of polyester coated with a silicone, for example.

The removable liner may provide temporary structure to the optional coupling layer 140. For example, WO2014/197194 and WO2014/197368 describe removable liners that emboss a coupling layer where the coupling layer loses its structures slowly once the removable liner is stripped away from the optical adhesive layer. This allows for ease of application where the temporary structure can allow for air bleed in lamination which then disappears in the laminated construction.

FIG. 12 is a schematic diagram perspective view of an illustrative folding article 1200 including an illustrative multilayer fdm 200. The multilayer fdm 200 may be any of the multilayer fdm constructions described herein disposed on an optical element such as an optical display 340. The display device is, in some embodiments, not be a folding article and may only flex within a certain range, for example, or may be a static curved display device.

An optical display 340 may form at least a portion of display device. The display device 1200 may include a display window 320. The display device 1200 can be any useful article such as a phone or smartphone, electronic tablet, electronic notebook, computer, and the like. The optical display may include an organic light emitting diode (OLED) display panel. The optical display may include a liquid crystal display (LCD) panel or a reflective display. Examples of reflective displays include electrophoretic displays, electrofluidic displays (such as an electrowetting display), interferometric displays or electronic paper display panels, and are described in U.S. Pat. Appl. Pub. No. 2015/0330597. In some cases, the optical display could be a static graphic fdm.

The multilayer fdm 100 and the optical display 340 may be foldable so that the optical display 340 faces itself and at least a portion of multilayer fdm 100 contacts or directly faces another portion of the protective fdm 100, as illustrated in FIG. 10. The multilayer fdm 100 and the optical display 340 may be flexible or bendable or foldable so that a portion of the multilayer fdm 100 and the optical display 340 can articulate relative to another portion of the multilayer fdm 100 and the optical display 340. The multilayer fdm 100 and the optical display 340 may be flexible or bendable or foldable so that a portion of the multilayer fdm 100 and the optical display 340 can articulate at least 90 degrees or at least 170 degrees relative to another portion of the multilayer fdm 100 and the optical display 340.

The multilayer fdm 100 and the optical display 340 may be flexible or bendable or foldable so that a portion of the multilayer fdm 100 and the optical display 340 can articulate relative to another portion of the multilayer fdm 100 and optical display 340 to form a bend radius of 5 mm or less in the multilayer fdm 100 at the bend or fold line. The multilayer fdm 100 and the optical display 340 may be flexible or bendable or foldable so that a portion of the multilayer fdm 100 and optical display 340 can articulate relative to another portion of the multilayer fdm 100 and the optical display 340 to form a bend radius such that the multilayer fdm 100 overlaps itself and is separated from each other by a distance on 10 mm or less, or 6 mm or less or 3 mm or less or 1 mm or less.

In some embodiments, an optical device (e.g., corresponding to article 700, 800, 900,

1000, 1100, or 1200), includes an optical display 160 or 340 and any of the multilayer fdm described herein bonded to the optical display 160. In some embodiments, the multilayer fdm is bonded to, and substantially coextensive with, a light output surface of the optical display 160.

The multilayer fdms described herein may have a haze value of 5% or less, 4% or less, 3% or less, 2% or less, or 1.5% or less, or 1% or less. In some embodiments the multilayer fdm may have a haze value of greater than 5% if the surface is structured to provide an antiglare function. The multilayer fdm may have a clarity of 95% or greater, 97% or greater, 98% or greater, or 99% or greater. The multilayer fdm may have a visible light transmission of 85% or greater, or 90% or greater, or 93% or greater.

The multilayer fdm may have a yellow index or b* value of 5 or less, or 4 or less, or 3 or less, or 2 or less, or 1 or less. In many embodiments the multilayer fdm may have a yellow index or b* value of 1 or less. Objects and advantages of this disclosure are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this disclosure.

Examples

Table 1. List of Materials used.

Preparatory Examples

Preparation of Polyol-1 with Catalyst In a standard mixer equipped with low shear blade was placed 200 lbs (91 kg) of K-FLEX

188 and 42 grams of DABCO T-12. The components were mixed under vacuum for 4 hours at 70°C and 28 inches (71 cm) of mercury to eliminate dissolved gases in the resin. The resulting resin was placed into 5 gallon (19 liter) pails for later use. Preparation of Polyol-2 with Catalyst

In a standard mixer equipped with low shear blade was placed 200 lbs (91 kg) of Fomrez 55-112 and 42 grams of DABCO T-12. The components were mixed under vacuum for 4 hours at 70°C and 28 inches (71 cm) of mercury to eliminate dissolved gases in the resin. The resulting resin was placed into 5 gallon (19 liter) pails for later use.

Preparatory Example 1: preparation of carboxylic acid silane solution

2500 grams of DMF was placed in a 4 liter brown glass jug. A Teflon coated stir bar was added to the jug, the jug was placed on a stir plate, and stirring initiated. 225 grams of succinic anhydride (SA) was added to the jug which dissolved in the DMF. 400 grams of 3- aminopropyltrimethoxysilane (APTMS) was slowly added to the jug. The solution in the jug was continuously stirred for 24 hours at room temperature to complete synthesis of the carboxylic acid silane which was confirmed by NMR. The resulting solution had 20.0 % by weight carboxylic acid silane in DMF. The carboxylic acid silane reaction is believed to be:

Preparatory Example 2: Carboxylic acid modified S1O₂ nanodispersion

49.33 kilograms of aqueous colloidal silica dispersion (NALCO 2327) was placed in a 75.71 liter stainless steel reactor. Agitation was initiated. 15.58 kilograms of carboxylic acid silane solution from Preparatory Example 1 was added to the reactor. The contents of the reactor were heated to 80°C. Upon reaching 80°C, the reactor was sealed, and the contents of the reactor maintained at 80°C with continuous agitation for 24 hours. After 24 hours, the contents of the reactor were cooled and filtered with a 50 pm filter and transferred to two 18.93 liter plastic lined metal drums. The pH of the nanoparticle dispersion was 5.5 and the nanoparticle concentration was calculated to be 31.3 wt%.

Preparatory Example 3: Carboxylic acid modified S1O₂ nanodispersion

3000 grams of carboxylic acid modified S1O2 nanodispersion from Preparatory Example 2 was placed in a 3.78 liter clear glass jar. A Teflon coated stir bar was added to the jar. The jar was placed on a stir plate and agitation initiated. 71.2 grams of aqueous ammonium hydroxide solution, nominally 28 wt%, was added to the nanoparticle dispersion. The contents of the jar were mixed for 20 minutes and then the stir bar was removed from the jar. The pH of the nanoparticle dispersion was 10.0 and the nanoparticle concentration was calculated to be 30.6 wt%.

Preparatory Example 4: NaOH Solution

3000 grams of deionized water was placed in a 3.8 liter clear glass jar. A Teflon coated stir bar was added to the jar. The jar was placed on a stir plate and stirring initiated. 1156 grams of sodium hydroxide (NaOH) pellets were incrementally added to the jar. The NaOH pellets dissolved in the water forming a clear solution that was 28 weight percent NaOH. The Teflon coated stir bar was removed from the jar. Preparatory Example 5: Preparation of 15 wt% SURLYN 9120 aqueous dispersion

27.76 kilograms of deionized water was placed in a 37.85 liter stainless steel reactor. 5.11 kilograms of SURLYN 9120 ionomer was added to the reactor and agitation with a stainless steel blade was initiated at 30 rpm. SURLYN 9120 is a partially neutralized poly(ethylene-co- methacrylic acid) ionomer with a melt flow index (MFI) of 1.3, acid content of 19 weight percent, with 38% neutralization with Zn²⁺ ions. 1.21 kilograms of the 28 weight percent sodium hydroxide (NaOH) aqueous solution from Preparatory Example 4 was added to the reactor. The agitation was increased to 120 rpm. The mixture was heated to 150°C and held for 2.5 hours with continuous agitation in the closed (pressurized) reactor. The ionomer dispersed to form a milky white aqueous solution with -15% by weight neutralized SURLYN 9120.

Preparatory Example 6: Preparation of 15 wt% 44/56 PRIMACOR 5980i/SURLYN 9120 dispersion

27.58 kilograms of deionized water was placed in a 37.85 liter stainless steel reactor. 2.27 kilograms of PRIMACOR 5980i was added to the reactor. 2.90 kilograms of SURLYN 9120 was added to the reactor and agitation with a stainless steel blade was initiated at 30 rpm. PRIMACOR 5980i is a poly(ethylene-co-acrylic acid) Copolymer with a MFI of 300, acid content of 20.5 weight percent, and it is not neutralized. SURLYN 9120 is a partially neutralized poly(ethylene- co-methacrylic acid) ionomer with a melt flow index (MFI) of 1.3, acid content of 19 weight percent, with 38% neutralization with Zn²⁺ ions. 1.53 kilograms of the 28 weight percent sodium hydroxide (NaOH) aqueous solution from Preparatory Example 4 was added to the reactor. The agitation was increased to 120 rpm. The mixture was heated to 150°C and held for 2.5 hours with continuous agitation in the closed (pressurized) reactor. The ionomer dispersed to form a milky white aqueous solution with -15% by weight neutralized SURLYN 9120.

Preparatory Example 7: Preparation of 15 wt% SURLYN 8150 aqueous dispersion

1275 grams of deionized water was placed in a two liter cylindrical glass reactor (Ace Glass, Vineland, NJ). 225 grams of SURLYN 8150 ionomer was added to the reactor and agitation initiated at 120 rpm. SURLYN 8150 is a partially neutralized poly(ethylene-co-methacrylic acid) ionomer with a MFI of 4.5, acid content of 19 weight percent, and 45 percent neutralization with Na⁺ ions. No additional base was added to the reactor. The mixture was heated to 100°C and held for 2.5 hours with continuous agitation in the open (atmospheric pressure) reactor. The ionomer dispersed to form a hazy aqueous dispersion.

Preparatory Example 8: Preparation of 15 wt% SURLYN 7940 aqueous dispersion 1248 grams of deionized water was placed in a two liter cylindrical glass reactor (Ace Glass, Vineland, NJ). 225 grams of SURLYN 7940 ionomer was added to the reactor and agitation initiated at 120 rpm. SURLYN 7940 is a partially neutralized poly(ethylene-co-methacrylic acid) ionomer with aMFI of 2.6, acid content of 15 weight percent, and 40 percent neutralization with Li⁺ ions. 26 grams of DMEA was added to the reactor. The mixture was heated to 100°C and held for 2.5 hours with continuous agitation in the open (atmospheric pressure) reactor. The ionomer dispersed to form an opaque white aqueous dispersion.

Preparatory Example 9: Preparation of 15 wt% NUCREL 960 aqueous dispersion

27.95 kilograms of deionized water was placed in a 37.85 liter stainless steel reactor. 5.10 kilograms of NUCREL 960 copolymer was added to the reactor and agitation initiated with a stainless steel blade was initiated at 30 rpm. NUCREL 960 is a poly(ethylene-co-methacrylic acid) copolymer with a MFI of 60, acid content of 15 weight percent, and 0 percent neutralization. 0.95 kilograms of the 28 weight percent sodium hydroxide solution from Preparatory Example 4 was added to the reactor. The agitation was increased to 120 rpm. The mixture was heated to 150°C and held for 2.5 hours with continuous agitation in the closed (pressurized) reactor. The ionomer dispersed to form a hazy aqueous dispersion of partially neutralized ionomer.

Preparatory Film Substrates for Layers 110 and 115 Preparatory Film Substrate Example SI

A film was made by coating the 15 wt% SURLYN 9120 aqueous dispersion from Preparatory Example 5 on to the unprimed side of a 75 pm polyester substrate (PET). The dispersion was applied to the PET substrate in a roll to roll process where the solution was metered through a slot die onto the moving web. Thickness was controlled by the use of a metering pump and a mass flow meter and solution was filtered through a Roki HT-40 filter (ROKI TECHNO Co., Ltd., Tokyo, Japan). The volatile components of the dispersion were removed by drying in a three-zone air flotation zoned oven (ovens temperatures set to 66°C, 93°C and 135°C). The dried coating had a thickness of ~10mhi and the film was wound into a roll. The coating on PET had a Transmission of 93.0%, Haze of 0.82%, and Clarity of 99.9%. The PET with no coating had a Transmission of 91.5%, Haze of 0.65%, and Clarity of 99.9%.

Preparatory Film Substrate Example S2

A coating solution was made by mixing 1319 grams of the 15 wt% dispersion of SURLYN 9120 from Preparatory Example 5 and 431 grams of carboxylic acid modified S1O2 nanodispersion from Preparatory Example 3. A film was made by coating the ionic elastomer nanocomposite dispersion onto a 75 pm polyester substrate (PET). The dispersion was applied to the unprimed side of the PET substrate in a roll to roll process where the solution was metered through a slot die onto the moving web. Thickness was controlled by the use of a metering pump and a mass flow meter and solution was filtered through a Roki HT-40 filter (ROKI TECHNO Co., Ltd., Tokyo, Japan). The volatile components of the dispersion were removed by drying in a three-zone air flotation zoned oven (ovens temperatures set to 66°C, 93°C and 135°C). The dried coating had a thickness of ~10pm and the film was wound into a roll. The dried film had 40 wt% 20nm S1O2 nanoparticles. The coating on PET had a Transmission of 92.8%, Haze of 0.54%, and Clarity of 99.9%.

Preparatory Film Substrate Example S3

A film was made by coating the 15 wt% 44/56 PRIMACOR5980i/SURLYN 9120 aqueous dispersion from Preparatory Example 5 on to the unprimed side of a 75 pm polyester substrate (PET). The dispersion was applied to the PET substrate in a roll to roll process where the solution was metered through a slot die onto the moving web. Thickness was controlled by the use of a metering pump and a mass flow meter and solution was filtered through a Roki HT-40 filter (ROKI TECHNO Co., Ltd., Tokyo, Japan). The volatile components of the dispersion were removed by drying in a three-zone air flotation zoned oven (ovens temperatures set to 66°C, 93 °C and 135°C). The dried coating had a thickness of ~10pm and the film was wound into a roll. The coating on PET had a Transmission of 93.4%, Haze of 0.54%, and Clarity of 99.9%.

Preparatory Film Substrate Example S4

A coating solution was made by mixing 1326 grams of the 15 wt% 44/56 PRIMACOR5980i/SURLYN 9120 aqueous dispersion from Preparatory Example 5 and 424 grams of carboxylic acid modified S1O2 nanodispersion from Preparatory Example 2. A film was made by coating the elastic ionomer nanocomposite dispersion onto the unprimed side of a 75um polyester substrate (PET). The dispersion was applied to the PET substrate in a roll to roll process where the solution was metered through a slot die onto the moving web. Thickness was controlled by the use of a metering pump and a mass flow meter and solution was filtered through a Roki HT-40 filter (ROKI TECHNO Co., Ltd., Tokyo, Japan). The volatile components of the dispersion were removed by drying in a three-zone air flotation zoned oven (ovens temperatures set to 66°C, 93°C and 135°C). The dried coating had a thickness of ~10pm and the film was wound into a roll. The dried film had 40 wt% 20nm S1O2 nanoparticles. The coating on PET had a Transmission of 92.9%, Haze of 0.53%, and Clarity of 99.9%. Preparatory Film Substrate Example S5

A coating solution was made by mixing 1319 grams of the 15 wt% dispersion of SURLYN 8150 from Preparatory Example 6 and 431 grams of carboxylic acid modified S1O2 nanodispersion from Preparatory Example 2. A film was made by coating the elastic ionomer nanocomposite dispersion onto the unprimed side of a 75 pm polyester substrate (PET). The dispersion was applied to the PET substrate in a roll to roll process where the solution was metered through a slot die onto the moving web. Thickness was controlled by the use of a metering pump and a mass flow meter and solution was filtered through a Roki HT-40 filter (ROKI TECHNO Co., Ltd., Tokyo, Japan). The volatile components of the dispersion were removed by drying in a three-zone air flotation zoned oven (ovens temperatures set to 66°C, 93°C and 135°C). The dried coating had a thickness of ~10mhi and the film was wound into a roll. The dried film had 40 wt% 20nm S1O2 nanoparticles. The coating on PET had a Transmission of 93.0%, Haze of 0.59%, and Clarity of 99.9%.

Preparatory Film Substrate Example S6

A coating solution was made by mixing 1319 grams of the 15 wt% dispersion of SURLYN 7940 from Preparatory Example 8 and 431 grams of carboxylic acid modified S1O2 nanodispersion from Preparatory Example 3. A film was made by coating the elastic ionomer nanocomposite dispersion onto the unprimed side of a 75um polyester substrate (PET). The dispersion was applied to the PET substrate in a roll to roll process where the solution was metered through a slot die onto the moving web. Thickness was controlled by the use of a metering pump and a mass flow meter and solution was filtered through a Roki HT-40 filter (ROKI TECHNO Co., Ltd., Tokyo, Japan). The volatile components of the dispersion were removed by drying in a three-zone air flotation zoned oven (ovens temperatures set to 66°C, 93°C and 135°C). The dried coating had a thickness of ~ 1 Omip and the film was wound into a roll. The dried film had 40 wt% 20nm S1O2 nanoparticles. The coating on PET had a Transmission of 92.9%, Haze of 0.66%, and Clarity of 99.8%.

Preparatory Film Substrate Example S7

A coating solution was made by mixing 1319 grams of the 15 wt% dispersion of NUCREL 960 from Preparatory Example 8 and 431 grams of carboxylic acid modified S1O2 nanodispersion from Preparatory Example 3. A film was made by coating the elastic ionomer nanocomposite dispersion onto the unprimed side of a 75um polyester substrate (PET). The dispersion was applied to the PET substrate in a roll to roll process where the solution was metered through a slot die onto the moving web. Thickness was controlled by the use of a metering pump and a mass flow meter and solution was fdtered through a Roki HT-40 fdter (ROKI TECHNO Co., Ltd., Tokyo, Japan The volatile components of the dispersion were removed by drying in a three- zone air flotation zoned oven (ovens temperatures set to 66°C, 93 °C and 135°C). The dried coating had a thickness of ~10pm and the fdm was wound into a roll. The dried fdm had 40 wt% 20nm S1O2 nanoparticles. The coating on PET had a Transmission of 92.7%, Haze of 0.54%, and Clarity of 99.9%.

Preparatory Film Substrate Example S8

A coating solution was made by mixing 659.5 grams of the 15 wt% dispersion of NUCREL 960 from Preparatory Example 8 and 659.5 grams of the 15 wt% dispersion of SURLYN 9120 from Preparatory Example 5 and 43 lg of carboxylic acid modified S1O2 nanodispersion from Preparatory Example 3. A film was made by coating the elastic ionomer nanocomposite dispersion onto the unprimed side of a 75um polyester substrate (PET). The dispersion was applied to the PET substrate in a roll to roll process where the solution was metered through a slot die onto the moving web. Thickness was controlled by the use of a metering pump and a mass flow meter and solution was filtered through a Roki HT-40 filter (ROKI TECHNO Co., Ltd., Tokyo, Japan). The volatile components of the dispersion were removed by drying in a three-zone air flotation zoned oven (ovens temperatures set to 66°C, 93°C and 135°C). The dried coating had a thickness of ~ 1 Opm and the film was wound into a roll. The dried film had 40wt% 20nm S1O2 nanoparticles. The coating on PET had a Transmission of 92.7%, Haze of 0.62%, and Clarity of 99.9%.

Preparatory Film Substrate Example S9

A melt-processed monolithic film of a SURLYN 9120 ionomer was prepared using a Plasti-corder (C.W. Brabender Instruments, Inc., South Hackensack, NJ). 50.0 grams of SURLYN 9120 pellets was added to the preheated Plasti-corder and was processed for 15 minutes at 150°C and 75 rpm. After processing the melt-processed material was cooled to room temperature. A portion of the melt-processed material was pressed into a film using an Auto Series Hot Press (Carver Inc., Wabash, IN). A portion of the melt-processed film was placed between two layers of polyimide film which were between two polished aluminum plates. To press the samples, the melt-processed material was pressed to 900 kg force at 125°C and held for 5 minutes. The sample was then pressed to 10900 kg force at 125°C and held for 0.1 minutes (6 seconds). The pressed film was removed from the press and from between the aluminum plates and cooled to room temperature. The polyimide sheets are removed once the film sufficiently cooled. The thickness of the pressed film was 7.1 mil (-180 microns) and the film had a Transmission of 92.3%, Haze of 3.5%, and Clarity of 96.8%. Films of controlled thickness may be made via known extrusion casting and orientation methods to produce rolls of monolithic film at thickness from 25-250 microns.

Preparatory Film Substrate Example S10

A melt-processed monolithic film of a 44 wt% PRIMACOR 5980i and 56% SURLYN 9120 ionomer was prepared using a Plasti-corder (C.W. Brabender Instruments, Inc., South Hackensack, NJ). 22.0 grams of PRIMACOR 5980i pellets and 28.0 grams SURLYN 9120 pellets were added to the preheated Plasti-corder and the materials were processed for 15 minutes at 150°C and 75 rpm to form a blend. After processing the melt-processed polymer blend was cooled to room temperature. A portion of the melt-processed material was pressed into a film using an Auto Series Hot Press (Carver Inc., Wabash, IN). A portion of the melt-processed film was placed between two layers of polyimide film which were between two polished aluminum plates. To press the samples, the melt-processed material was pressed to 900 kg force at 125°C and held for 5 minutes. The sample was then pressed to 10900 kg force at 125°C and held for 0.1 minutes (6 seconds). The pressed film was removed from the press and from between the aluminum plates and cooled to room temperature. The polyimide sheets are removed once the film sufficiently cooled. The thickness of the pressed film was 6.5 mil (-165 microns) and the film had a Transmission of 92.4%, Haze of 3.1%, and Clarity of 97.1%. Films of controlled thickness may be made via known extrusion casting and orientation methods to produce rolls of monolithic film at thickness from 25-250 microns.

Preparatory Film Substrate Example Sll

A melt-processed monolithic nanocomposite film with a composition of 20 wt% 20nm S1O2 nanoparticles 40 wt% SURLYN 9120 and 40 wt% NUCREL 699 was prepared using a Plasti-corder (C.W. Brabender Instruments, Inc., South Hackensack, NJ). 25.0 grams of the coating from Preparatory example S2 was removed from the PET substrate, along with 5.0 grams of SURLYN 9120 pellets and 20.0 grams of NUCREL 699 pellets were added to the preheated Plasti-corder and the materials were processed for 15 minutes at 150°C and 75 rpm to form a nanocomposite blend. After processing the melt-processed polymer blend was cooled to room temperature. A portion of the melt-processed material was pressed into a film using an Auto Series Hot Press (Carver Inc., Wabash, IN). A portion of the melt-processed film was placed between two layers of polyimide film which were between two polished aluminum plates. To press the samples, the melt-processed material was pressed to 900 kg force at 125°C and held for 5 minutes. The sample was then pressed to 10900 kg force at 125°C and held for 0.1 minutes (6 seconds). The pressed film was removed from the press and from between the aluminum plates and cooled to room temperature. The polyimide sheets are removed once the film sufficiently cooled. The thickness of the pressed film was 7.7 mil (-196 microns) and the film had a Transmission of 93.0%, Haze of 3.4%, and Clarity of 94.3%. Films of controlled thickness may be made via known extrusion casting and orientation methods to produce rolls of monolithic film at thickness from 25-250 microns.

Preparatory Film Substrate Example S12

A melt-processed monolithic nanocomposite film with a composition of 20 wt% 20nm S1O2 nanoparticles 40 wt% SURLYN 9120 and 40wt% PRIMACOR 1410 was prepared using a Plasti-corder (C.W. Brabender Instruments, Inc., South Hackensack, NJ). 25.0 grams of the coating from Preparatory Example S2 was removed from the PET substrate, along with 5.0 grams of SURLYN 9120 pellets and 20.0 grams of PRIMACOR 1410 pellets were added to the preheated Plasti-corder and the materials were processed for 15 minutes at 150°C and 75 rpm to form a nanocomposite blend. After processing the melt-processed polymer blend was cooled to room temperature. A portion of the melt-processed material was pressed into a film using an Auto Series Hot Press (Carver Inc., Wabash, IN). A portion of the melt-processed film was placed between two layers of polyimide film which were between two polished aluminum plates. To press the samples, the melt-processed material was pressed to 900 kg force at 125°C and held for 5 minutes. The sample was then pressed to 10900 kg force at 125°C and held for 0.1 minutes (6 seconds). The pressed film was removed from the press and from between the aluminum plates and cooled to room temperature. The polyimide sheets are removed once the film sufficiently cooled. The thickness of the pressed film was 11.3 mil (-287 microns) and the film had a Transmission of 91.2%, Haze of 3.6%, and Clarity of 96.1%. Films of controlled thickness may be made via known extrusion casting and orientation methods to produce rolls of monolithic film at thickness from 25-250 microns.

Preparatory Film Substrate Example S13

A melt-processed monolithic nanocomposite film with a composition of 20 wt% 20nm S1O2 nanoparticles 40 wt% SURLYN 8150 and 40 wt% SURLYN 9020 was prepared using a Plasti-corder (C.W. Brabender Instruments, Inc., South Hackensack, NJ). 25.0 grams of the coating from Preparatory example S5 was removed from the PET substrate, along with 5.0 grams of SURLYN 8150 pellets and 20.0 grams of SURLYN 9020 (terpolymer) pellets were added to the preheated Plasti-corder and the materials were processed for 15 minutes at 150°C and 75 rpm to form a nanocomposite blend. After processing the melt-processed polymer blend was cooled to room temperature. A portion of the melt-processed material was pressed into a film using an Auto Series Hot Press (Carver Inc., Wabash, IN). A portion of the melt-processed film was placed between two layers of polyimide film which were between two polished aluminum plates. To press the samples, the melt-processed material was pressed to 900 kg at 125°C and held for 5 minutes. The sample was then pressed to 10900 kg force at 125°C and held for 0.1 minutes (6 seconds). The pressed film was removed from the press and from between the aluminum plates and cooled to room temperature. The polyimide sheets are removed once the film sufficiently cooled. The thickness of the pressed film was 3.5 mil (~89 microns) and the film had a Transmission of 93.4%, Haze of 3.6%, and Clarity of 94.7%. Films of controlled thickness may be made via known extrusion casting and orientation methods to produce rolls of monolithic film at thickness from 25-250 microns.

Preparatory Energy Dissipation Layers (Layer 130)

Aliphatic Polyurethane Energy Dissipation Layer Intermediates PU15-PU22

Samples of shape memory polyurethane (PU) were prepared in a roll to roll process where the isocyanate and polyol with catalyst were mixed using an inline dynamic mixer. The solutions were applied to a moving web between two silicone release liners at an appropriate flow rate to achieve the desired final sample thickness. The polyurethane between films were heated at 70°C and wound into a roll. The films were postbaked at 70°C for 24 hours prior to lamination to glass. Samples had a range of equivalents of NCO reacted with 1.0 equivalents of -OH, as shown in Table 2 in order to achieve the desired glass transition temperature and crosslink concentration. Relative proportions by mass of Polyol 1 and Polyisocyanate 1 for intermediate films PU15-PU22 are shown in Table 2. The coated materials contained about 350ppm dibutyltin dilaurate catalyst.

Table 2: Coating compositions and theoretical crosslink concentration

Polyurethane Film Preparative Intermediates PU23-PU26

The polyurethanes for Examples PU23 - PU26, were composed of a polyol 1 (K-FLEX 188) reacted with a blend of multifunctional isocyanates, Polyisocyanate 1 and Polyisocyanate 2, prepared in the same manner as samples P15-PU22. The weight ratio Polyol 1 to Polyisocyanate 1 to Polyisocyanate 2 for samples PU23-PU26 are shown in Table 3. Polyisocyanate 2 contains a uretdione unit that can react with excess OH in the polyol component at elevated temperature to form an allophanate group. For this reason, the table contains two stoichiometric ratio columns. The first calculates the NCO/OH ratio based on only existing NCO content in Polyisocyanate 1 and Polyisocyanate 2 at the beginning of the reaction. The NCO+UD/OH ratio accounts for the ratio after the uretdione is reacted with excess OH of the polyol. The theoretical gel content and crosslink concentration are reported in Table 3. Table 3: Mix ratios for polyurethanes for Examples PU13-PU16

Polyurethane Film Preparative Intermediate PU27

Polyurethane Substrate intermediate PU27 coating was made with an alternative polyol, Fomrez 55-112 (Polyol 2) in order to provide a film having a lower glass transition temperature . The polyurethane was composed of polyol 2 reacted with Polyisocyanate 1, prepared in the same manner as samples PU15-PU22. The weight ratio Polyol 2 to Polyisocyanate 1 for sample PU27 is shown in Table 4. Ovens were run at 70°C and the samples were post-cured for 24 hours at 70°C Table 4: Coating composition and theoretical crosslink concentration

Polyurethane Film Intermediates Characterization

The glass transition temperature of the polyurethane coatings was characterized using Q800 DMA from TA Instruments. Samples were cut into strips 6.35 mm wide and about 4 cm long. The thickness of each film was measured. The films were mounted in the tensile grips of a Q800 DMA from TA Instruments with an initial grip separation between 16 mm and 19 mm. The samples were then tested at an oscillation of 0.2% strain and 1 Hz throughout a temperature ramp from -50 °C to 200 °C at a rate of 2 °C per minute. The results are shown in Table 5. The onset of the glass transition was determined by DSC and by location of peak for E". The temperature at which the Tan Delta signal reached a maximum was recorded as the peak Tan Delta temperature.

Table 5: Thermal and mechanical properties of the coatings alone

Preparatory Substrate Example S15:

Into a Flacktek Inc. size 20 speedmixer cup was added 14 g of K-FLEX 188 containing ~500ppm of DABCO T-12 and ~10.0g of Desmodur N-3300A. The contents were mixed using a Flacktek DAC 150 FVZ-K speedmixer and were mixed at 1500 rpm for 30 seconds. The resulting resin was viscous was homogeneous and near colorless. A sample of 100 micron thick Schott glass (Type D263™ T eco), 152.4mm x 50.4mm was provided and placed onto the surface of a silicone release liner where the glass wetout to the surface of the silicone liner. The viscous mixture was applied to the surface of the glass by coating the polyurethane over the glass sample by pulling two release liners with the glass on the lower release liner under a notch bar having a defined gap to produce a 100 micron thick coating of polyurethane on the 100 micron thick glass. The sample between liners was cured at 70°C for 24 hours. The two release liners were removed to give the glass and polyurethane construction. Excess polyurethane was trimmed from the edge of the glass and the construction was subjected to ball drop and impact testing and results are described in Table 6.

Preparatory Substrate Example S16:

A 3 inch by 6 inch (7.6 cm x 15.2 cm) sample of glass was cut using a diamond scribe from a roll of NEG glass (material OA-10G, 300 mm wide, 30m length, 100 micron thickness). A fdm sample of shape memory polyurethane was prepared by coating between two silicone release liners. The polyurethane film was made by mixing a polyol containing ~500ppm of a tin catalyst and an isocyanate. The Polyol with catalyst (K-FLEX 188) and isocyanate (DESMODUR N3300) were added to separate pumps with mass flow controllers. The Polyol with catalyst was heated to 60 degrees C to lower the viscosity. The two components were delivered in controlled stoichiometry from the pumps via mass flow control to a Kenics static mixer (355mm long, with 32 elements). The mass flow rate for the Polyol with catalyst and DESMODUR N3300 were to 32.8 g/min and 20.74 g/min respectively to give an overall target NCO/OH ratio for the polyurethane reactive mixture of 0.8. The 2-part polyurethane reactive mixture was coated between two silicone release liners (T50 release liner available from Eastman Chemical). The reactive mixture was coated to a desired thickness between the release fdms in a continuous fashion using a notch bar coating method where thickness was controlled by setting a defined gap. The coated polyurethane film was heated at elevated temperature on hot platens to gel the polyurethane film and resulting film was placed into a 70°C oven for 16 hours to cure. The resulting film with liners was -260 um. The polyurethane film was ~156um. Physical properties of this film should correlate with Preparatory Polyurethane Film Preparative Intermediate PU17.

A glass/polyurethane construction was made by peeling the liner from one side of the polyurethane film and laminating it to the 3 inch by 6 inch (7.6 cm x 15.2 cm) glass sample. This laminated structure was heated at 70°C for approximately 24 hours. The second liner was removed from the polyurethane layer and the glass/polyurethane construction was subjected to ball drop and impact testing and results are described in Table 6.

Preparatory Substrate Example S17:

A 3 inch by 6 inch (7.6 cm x 15.2 cm) sample of glass was cut using a diamond scribe from a roll of NEG glass (material OA-10G, 300 mm wide, 30m length, 100 micron thickness).

To 3400) were added to separate pumps with mass flow controllers. The Polyol with catalyst was heated to 60 degrees C to lower the viscosity. The two components were delivered in controlled stoichiometry from the pumps via mass flow control to a Kenics static mixer (355mm long, with 32 elements). The mass flow rates for the Polyol with catalyst and DESMODUR N3300 and Desmodur 3400 were set to 65.2 g/min, 17.4 g/min and 17.4 g/min respectively to give an overall target NCO/OH ratio for the polyurethane reactive mixture of 0.67. The 2-part polyurethane reactive mixture was coated between two silicone release liners (for example T50 release liner available from Eastman Chemical). The reactive mixture was coated to a desired thickness between the release films in a continuous fashion using a notch bar coating method where thickness was controlled by setting a defined gap. The coated polyurethane film was heated at elevated temperature (~160°F) on hot platens to gel the polyurethane film and resulting film was placed into a 70°C oven for 16 hours to cure. The resulting film with liners was -240 pm thick. The polyurethane film was -136 pm thick.

A glass/polyurethane construction was made by peeling the liner from one side of the polyurethane film and laminating it to the glass. This laminated structure was heated at 70°C for approximately 24 hours. The second liner was removed and the glass/polyurethane construction was subjected to ball drop and impact testing and results are described in Table 6. Table 6: Impact test results for Glass Polyurethane Constructions

The impact resistance of the Preparative Substrate Examples S15 - S17 were tested two ways: first by dropping a 4.3 g stainless steel ball on to the glass side of each construction and then by dropping a BIC (Societe Bic, Ile-de-France, France) stick pen (1mm ball tip) with cap attached to the non-writing end (total weight 5.5 g), from the specified height. The drop height was measured from the bottom of the ball or writing tip of the pen to the surface of the sample. The ball and pen were both dropped down a narrow tube that ensured that the pen hit the sample at approximately 90 degree angle with respect to the surface. A new area of the sample free of pre existing cracks was used for each drop test. The maximum drop height that could be tested with the apparatus was 27 cm for the ball and 16 cm for the pen. The critical height was recorded as the maximum height the ball or pen could be dropped from without a permanent mark or the glass cracking.

Examples

Comparative Example 1:

A sample of 100 micron thick Schott glass (Type D263™ T eco), 152.4mm x 50.4mm was provided for optical and impact testing the data for which is shown in Table 7. A bending test was performed by bending the glass sample around a 4 mm diameter mandrel. This test was done very carefully in controlled conditions with proper safety equipment and shielding. The glass broke in the course of the bending around the mandrel long before reaching a 2 mm radius and the glass exploded. As can be seen in Figure 14, the glass shattered into literally thousands of fine shards.

Example 1:

A sample of 100 micron thick Schott glass (Type D263™ T eco), 152.4mm x 50.4mm was provided. To a first side of the glass was laminated the Elastic Ionomer Fayer of Preparatory Film Substrate Example S2. A few drops of deionized water were placed onto the glass and the SURFYN 9120 nanocomposite ionomer layer was wet down to the glass. A squeegee was used to squeeze out and remove excess DI water between the glass and the ionomer film. The film was allowed to sit at room temperature for approximately 1 hour and was then placed into a 70°C oven to bond the ionomer film to the glass. The ionomer glass composite construction was removed from the oven and was allowed to cool. The PET layer was removed from the ionomer giving an example of the construction shown in FIG. 1. The optical properties of this samples were measured using aHazegard Plus giving a transmission of 93.1%, haze of 0.95%.

Example 2:

A sample of 100 micron thick Schott glass (Type D263™ T eco), 152.4mm x 50.4mm was provided. To a first side of the glass was laminated the Elastic Ionomer Layer of Preparatory Film Substrate Example S2. A few drops of deionized water were placed onto the glass and the SURLYN 9120 nanocomposite ionomer layer was wet down to the glass. A squeegee was used to squeeze out and remove excess DI water between the glass and the ionomer film. The film was allowed to sit at room temperature for approximately 1 hour and was then placed into a 70°C oven to bond the ionomer film to the glass. The ionomer glass composite construction was removed from the oven and was allowed to cool. A second layer of the 9120 ionomer film coated on PET was then applied to the opposite side of the glass using the same procedure. Once the second layer was cool, one of the PET layers was removed from the ionomer. To the surface of that ionomer was added a second 9120 ionomer layer using the same procedure. Once cooled, the PET was removed from the second ionomer layer and the procedure was repeated again to put down a third layer of ionomer again using the same procedure. Once cooled, the PET films were removed from the 9120 ionomer layers on both sides of the glass giving a construction having an ~10 micron layer of 9120 ionomer on one side and a ~30 micron layer on the opposite side of the 100 micron glass layer giving an example of the construction shown in FIG. 2. Optical measurements and impact testing was performed on this sample based on the details described below and data is shown Table 7. A bending test was performed by bending the sample around a 4 mm diameter mandrel. The glass broke in the course of the bending event and as can be seen in Figure 13 the elastic ionomer layer contained the broken glass fragments.

Example 3:

A sample of 100 micron thick Schott glass (Type D263™ T eco), 152.4mm x 50.4mm was provided. To a first side of the glass was laminated the Elastic Ionomer Layer of Preparatory Film Substrate Example SI. A few drops of deionized water were placed onto the glass and the SURLYN 9120 ionomer layer was wet down to the glass. A squeegee was used to squeeze out and remove excess DI water between the glass and the ionomer film. The film was allowed to sit at room temperature for approximately 1 hour and was then placed into a 70°C oven to bond the ionomer film to the glass. The ionomer glass composite construction was removed from the oven and was allowed to cool. A second layer of the 9120 ionomer film coated on PET was then applied to the opposite side of the glass using the same procedure. Once the second layer was cool, one of the PET layers was removed from the ionomer. To the surface of that ionomer was added a second 9120 ionomer layer using the same procedure. Once cooled, the PET was removed from the second ionomer layer and the procedure was repeated again to put down a third layer of ionomer again using the same procedure. Once cooled, the PET films were removed from the 9120 ionomer layers on both sides of the glass giving a construction having an ~10 micron layer of 9120 ionomer on one side and a ~30 micron layer on the opposite side of the 100 micron glass layer giving an example of the construction shown in FIG. 2. Optical measurements and impact testing were performed on this sample based on the details described below and data is shown Table 7.

Table 7: Impact test results for Glass Polyurethane Constructions

The impact resistance of Examples 2 and 3 were tested by dropping a BIC (Societe Bic S.A. Ile-de-France, France) stick pen (1mm ball tip) with cap attached to the non-writing end (total weight 5.5 g), from the specified height. The sample was placed onto a steel plate at the bottom of the apparatus. The drop height was measured from the bottom of the writing tip of the pen to the surface of the sample. The pen was dropped down a narrow tube that ensured that the pen hit the sample at approximately 90 degree angle with respect to the surface. A new area of the sample free of pre-existing cracks was used for each drop test. The maximum drop height that could be tested with the apparatus was 20 cm for the pen. The critical height was recorded as the maximum height the pen could be dropped from without the glass cracking or fracturing.

Example 4:

To the free side of the glass of Preparatory Substrate S16 is laminated the Elastic Ionomer Fayer of Preparatory Film Substrate Example S2. A few drops of deionized water are placed onto the glass and the SURFYN 9120 nanocomposite ionomer layer is wet down to the glass. A squeegee is used to squeeze out and remove excess DI water between the glass and the ionomer film. The film is allowed to sit at room temperature for approximately 1 hour and is then placed into a 70°C oven to bond the ionomer film to the glass. The ionomer glass composite construction is removed from the oven and allowed to cool. The PET layer is removed from the ionomer giving an example of the construction shown in FIG. 3. The sample is expected to have transmission > 90%, Haze < 2%, and clarity > 95%. The glass is expected to survive a pen drop impact from a height in excess of 16cm and a ball drop impact of greater than 27 cm (test protocol detailed above for Table 6).

Example 5:

A sample of 100 micron thick Schott glass (Type D263™ T eco), 152.4mm x 50.4mm was provided. To a first side of the glass was laminated the Elastic Ionomer Layer of Preparatory Film Substrate Example S2. A few drops of deionized water weree placed onto the glass and the SURLYN 9120 nanocomposite ionomer layer was wet down to the glass. A squeegy was used to squeeze out and remove excess DI water between the glass and the ionomer film. The film was allowed to sit at room temperature for approximately 1 hour and was then placed into a 70°C oven to bond the ionomer film to the glass. The ionomer glass composite construction was removed from the oven and was allowed to cool.

A film sample of shape memory polyurethane was prepared by coating between two silicone release liners. The polyurethane film was made by mixing a polyol containing ~500ppm of a tin catalyst and an isocyanate. The Polyol with catalyst (K-FLEX 188) and isocyanate mixture (DESMODUR N3300 and DESMODUR 3400) were added to separate pumps with mass flow controllers. The Polyol with catalyst was heated to 60 degrees C to lower the viscosity. The two components were delivered in controlled stoichiometry from the pumps via mass flow control to a Kenics static mixer (355mm long, with 32 elements). The mass flow rates for the Polyol with catalyst and DESMODUR N3300 and DESMODUR 3400 were set to 65.2 g/min, 17.4 g/min and 17.4 g/min respectively to give an overall target NCO/OH ratio for the polyurethane reactive mixture of 0.67. The 2-part polyurethane reactive mixture was coated between two silicone release liners (for example T50 release liner available from Eastman Chemical). The reactive mixture was coated to a desired thickness between the release films in a continuous fashion using a notch bar coating method where thickness was controlled by setting a defined gap. The coated polyurethane film was heated at elevated temperature (~160°F) on hot platens to gel the polyurethane film and resulting film was placed into a 70°C oven for 16 hours to cure. The resulting film with liners was -240 um. The polyurethane film was ~136um.

A glass/polyurethane construction is made by peeling the liner from one side of the polyurethane film and laminating it to the glass. This laminated structure is heated at 70°C for approximately 24 hours. The second liner is removed from the polyurethane and the PET layer is removed from the Elastic Ionomer nanocomposite layer and the sample is tested. The sample is expected to have transmission > 90%, Haze < 2%, and clarity > 95%. The glass is expected to survive a pen drop impact from a height in excess of 16cm and a ball drop impact of greater than 27 cm (test protocol detailed above for Table 6).

Test Methods:

Transmission/Haze/Clarity T esting

Luminous transmission, haze, and clarity using a BYK-Gardner Haze-Gard Plus model 4725 (available from BYK-Gardner Columbia, MD). Measurements are the average of three measurements on a given sample. Samples with obvious optical defects in film preparation were not used in optical testing.

The film constructions described in the above examples with elastic ionomer nanocomposite glass composites may use a variety of elastic ionomer nanocomposites, additional examples shown in Preparatory Film Substrate Examples S4 -S8 and SI 1 - S13. These nancomposite layers can have a variety of thicknesses as needed for specific applications can be used in both layers 110 and 115. Elastic ionomer layers without nanoparticles for layer 115 may also be used, some additional examples shown in Preparatory Film Substrate Examples S3 and S9 and S 10. There are many suitable energy dissipation layer compositions that may be used for layer 130. The properties of some suitable examples detailed in Preparative Polyurethane intermediates PU15-PU27.

All references, patents, and patent applications referenced in the foregoing are hereby incorporated herein by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description shall control.

Descriptions for elements in figures should be understood to apply equally to corresponding elements in other figures, unless indicated otherwise. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof. Terms such as “about” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “about” as applied to quantities expressing feature sizes, amounts, and physical properties is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “about” will be understood to mean within 10 percent of the specified value. A quantity given as about a specified value can be precisely the specified value. For example, if it is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, a quantity having a value of about 1, means that the quantity has a value between 0.9 and 1.1, and that the value could be 1.

All references, patents, and patent applications referenced in the foregoing are hereby incorporated herein by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description shall control. Descriptions for elements in figures should be understood to apply equally to corresponding elements in other figures, unless indicated otherwise. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations, or variations, or combinations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.

Claims

What is claimed is:

1. A multilayer film comprising: a glass layer having a thickness less than 250 micrometers; a nanocomposite layer fixed to the glass layer, the nanocomposite layer comprising: at least one polymer, the at least one polymer comprising a first polymer comprising (meth)acrylic acid monomer units; and metal oxide nanoparticles dispersed in the at least one polymer, the metal oxide nanoparticles being surface modified with a surface modifying agent comprising a carboxylic acid silane of Formula 1 :

Formula 1 wherein:

R1 is a Ci to Cio alkoxy group;

R2 and R3 are independently selected from the group consisting of Ci to Cio alkyl and Ci to Cio alkoxy groups; and

A is a linker group selected from the group consisting of Ci to Cio alkylene or arylene groups, Ci to Cio aralkylene groups, C2 to Ci₆ heteroalkylene or heteroarylene groups, and C2 to Ci₆ amide containing groups.

2. The multilayer film of claim 1, wherein the average thickness of the glass layer is in a range of 25 micrometers to 100 micrometers.

3. The multilayer film of claim 1 or 2, where the nanocomposite layer has an average thickness in a range of 5 micrometers to 125 micrometers.

4. The multilayer film of any one of claims 1 to 3, wherein the first polymer further comprises at least one monomer unit selected from the group consisting of ethylene and propylene.

5. The multilayer film of any one of claims 1 to 4, wherein the at least one polymer further comprises a second polymer different from the first polymer, the second polymer comprising (meth)acrylic acid monomer units.

6. The multilayer film of claim 5, wherein the first polymer comprises (meth)acrylic acid monomer units at a first weight percent wl, and the second polymer comprises (meth)acrylic acid monomer units at a second weight percent w2, at least one of wl and w2 being greater than 12 weight percent, wherein |wl-w2| is less than 12 weight percent.

7. The multilayer film of any one of claims 1 to 6, wherein the nanocomposite layer has a shear modulus greater than 0.9 MPa at 20 degrees Celsius.

8. The multilayer film of any one of claims 1 to 7, wherein the first polymer has a number average molecular weight of at least 10000 grams/mole.

9. The multilayer film of any one of claims 1 to 8, wherein the nanocomposite layer is bonded directly to, and substantially coextensive with, the major surface of the glass layer.

10. The multilayer film of any one of claims 1 to 9, further comprising a layer having a static water contact angle of at least 100 degrees disposed on the nanocomposite layer opposite the glass layer.

11. The multilayer film of any one of claims 1 to 10, further comprising an additional layer disposed on the glass layer opposite the nanocomposite layer, the additional layer comprising a cross-linked polyurethane or a cross-linked polyurethane acrylate.

12. The multilayer film of any one of claims 1 to 10, further comprising a first additional layer disposed on the glass layer opposite the nanocomposite layer, the first additional layer comprising at least one polymer, the at least one polymer of the first additional layer comprising a first polymer comprising (meth)acrylic acid monomer units.

13. The multilayer film of claim 12, wherein the first additional layer further comprises surface- modified metal oxide nanoparticles dispersed in the at least one polymer of the first additional layer.

14. The multilayer film of claim 12 or 13, further comprising a second additional layer disposed on the first additional layer, the first additional layer being between the glass layer and the second additional layer, the second additional layer comprising a cross-linked polyurethane or a cross- linked polyurethane acrylate.

15. An optical device comprising an optical display and the multilayer fdm of any one of claims 1o 14 bonded to the optical display.