Multilayer compositions, multilayer adhesive compositions, and methods of making same

Abstract

The present disclosure provides a multilayer composition including a first layer including a first adhesive composition; a second layer including a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; and a third layer including a second adhesive composition. A latent UV crosslinker is present in at least one of the first layer or the second layer. Additionally, a UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer. A method of making the multilayer composition is also provided. Further, a multilayer adhesive composition is provided, in which a first adhesive composition is crosslinked.

Description

PA102995W002MULTILAYER COMPOSITIONS, MULTILAYER ADHESIVE COMPOSITIONS, AND METHODS OF MAKING SAMEField

[0001] The present disclosure generally relates to the field of multilayer compositions, including multilayer adhesive compositions.Background

[0002] There remains a need for imparting UV radiation resistance to certain adhesives without preventing the use of convenient UV-induced curing and / or crosslinking.Brief Description of Drawings

[0003] FIG. 1 is a schematic cross-sectional view of an exemplary multilayer composition, according to some embodiments of the present disclosure.

[0004] FIG. 2 is a schematic cross-sectional view of an exemplary multilayer adhesive composition, according to some embodiments of the present disclosure.

[0005] Repeated use of reference characters in the specification and drawings is intended to represent the same or analogous features or elements of the disclosure. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the disclosure. The figures may not be drawn to scale.Summary

[0006] In a first aspect, a multilayer composition is provided. The multilayer composition comprises a first layer comprising a first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; and a third layer comprising a second adhesive composition. A latent UV crosslinker is present in at least one of the first layer or the second layer. Further, a UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer.

[0007] In a second aspect, a method of making a multilayer composition is provided. The method comprises coextruding a first solution, a second solution, and a third solution, thereby forming a multilayer composition. The multilayer composition comprises a first layer comprising a first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; and a third layer comprising a second adhesive composition. A latent UV crosslinker is present in at least one of the first layer or the second layer. Further, a UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer.

[0008] In a third aspect, a method of making a multilayer adhesive composition is provided. The method comprises exposing to UV radiation the multilayer composition according to any embodiment of the first aspect.

[0009] In a fourth aspect, a multilayer adhesive composition is provided. The multilayer adhesive composition comprises a first layer comprising a crosslinked first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; and a third layer comprising a second adhesive composition. Further, UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer.

[0010] The above summary is not intended to describe each embodiment. The details of one or more embodiments are also set forth in the description below. Other features, objects, and advantages will be apparent from the description and from the claims.Detailed Description

[0011] The terms “a”, “an”, “the”, “at least one”, and “one or more” are used interchangeably.

[0012] The term “and / or” means one or both such as in the expression A and / or B refers to A alone, B alone, or to both A and B.

[0013] The term “essentially” means 95% or more.

[0014] The term “optically clear” refers to an adhesive or an article that has a high light transmittance over at least a portion of the visible light spectrum (about 400 to about 700 nanometers), and that exhibits low haze, typically less than about 2%. In some embodiments, optically clear adhesives or articles exhibit a haze of less than 1% at a thickness of 50 micrometers or even 0.5% at a thickness of 50 micrometers. Typically, optically clear adhesives or articles have a visible light transmittance of at least 95%, often higher such as 97%, 98% or even 99% or higher.

[0015] The term “crosslinkable composition” refers to the reaction mixture that may be crosslinked. The crosslinkable composition may include polymerizable components plus any other material, such as, for example, a free radical initiator, a chain transfer agent, an antioxidant, a solvent, and the like that may be included in the reaction mixture.

[0016] The term “curable” means that a solid material can be transformed into a more crosslinked solid by means of stimuli induced crosslinking.

[0017] As used herein, a “latent UV crosslinker” is a crosslinker that is typically only reactive in the system under conditions of exposure to UV radiation of wavelengths or intensities that are different than any UV radiation wavelengths or intensities used in the preparation of the adhesive to subsequently be crosslinked.

[0018] The term “polymer” means homopolymers, copolymers, terpolymers, and the like.

[0019] The term “polymer additive” means a polymer that is distributed in another composition. In some embodiments, a polymer additive is homogeneously distributed in the composition.

[0020] The term “polymerizable component” refers to a compound that can undergo polymerization (i.e., the compound has a polymerizable group). The polymerizable component typically has an ethylenically unsaturated group such as a (meth)acryloyl-containing group or a vinyl group that is the polymerizable group. The compounds that have a polymerizable group can be referred to as a “monomer”.

[0021] The term “alkyl” refers to a monovalent radical of an alkane. Suitable alkyl groups can have up to 50 carbon atoms, up to 40 carbon atoms, up to 30 carbon atoms, up to 20 carbon atoms, up to 16 carbon atoms, up to 12 carbon atoms, up to 10 carbon atoms, up to 8 carbon atoms, up to 6 carbon atoms, up to 4 carbon atoms, or up to 3 carbon atoms. The alkyl groups can be linear, branched, cyclic, or a combination thereof. Linear alkyl groups often have 1 to 30 carbon atoms, 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Branched alkyl groups often have 3 to 50 carbon atoms, 3 to 40 carbon atoms, 4 to 20 carbon atoms, 3 to 10 carbon atoms, or 3 to 6 carbon atoms. Cyclic alkyl groups often have 3 to 50 carbon atoms, 5 to 40 carbon atoms, 6 to 20 carbon atoms, 5 to 10 carbon atoms, or 6 to 10 carbon atoms.

[0022] The term “alkylene” refers to a divalent group that is a radical of an alkane. The alkylene can be straight-chained, branched, cyclic, or combinations thereof. The alkylene typically has 1 to 20 carbon atoms. In some embodiments, the alkylene contains 4 to 14 carbon atoms, 1 to 10 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. The radical centers of the alkylene can be on the same carbon atom (i.e., an alkylidene) or on different carbon atoms. In certain embodiments, the alkylene can be substituted with an OH group.

[0023] The term “hydroxyl group” means a monovalent group of formula -OH.

[0024] The term “isocyanate group” means a monovalent group of formula -N=C=O.

[0025] The term “aryl” refers to a monovalent group that is radical of an arene, which is a carbocyclic, aromatic compound. The aryl can have one to five rings that are connected to or fused to the aromatic ring. The other ring structures can be aromatic, non-aromatic, or combinations thereof. Examples of aryl groups include, but are not limited to, phenyl, biphenyl, terphenyl, naphthyl, acenaphthyl, anthraquinonyl, phenanthryl, anthracenyl, pyrenyl, perylenyl, and fluorenyl.

[0026] The term “aralkyl” refers to a monovalent group of formula -R-Ar where R is an alkylene and Ar is an aryl group. That is, the aralkyl is an alkyl substituted with an aryl.

[0027] The term “aralkylene” refers to a divalent group of formula -R-Ar3- where R is an alkylene and Ar3is an arylene (i.e., an alkylene is bonded to an arylene).

[0028] The term “arylene” refers to a divalent group that is carbocyclic and aromatic. The group has one to five rings that are connected, fused, or combinations thereof. The other rings can be aromatic, non-aromatic, or combinations thereof. In some embodiments, the arylene group has up to 5 rings, up to 4 rings, up to 3 rings, up to 2 rings, or one aromatic ring. For example, the arylene group can be phenylene. The term “alkarylene” refers to a divalent group that is an arylene group substituted with an alkyl group or an arylene group attached to an alkylene group. Unless otherwise indicated, the alkarylene group typically has from 1 to 20 carbon atoms, 4 to 14 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Unless otherwise indicated, for both groups, the alkyl or alkylene portiontypically has from 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. Unless otherwise indicated, for both groups, the aryl or arylene portion typically has from 6 to 20 carbon atoms, 6 to 18 carbon atoms, 6 to 16 carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms. In certain embodiments, the arylene group or the alkarylene group has 4 to 14 carbon atoms.

[0029] The term “(meth)acryloyl” refers to a group of formula CH2=CR-(CO)- where R is hydrogen (for an acryloyl group) or methyl (for a methacryloyl group).

[0030] The term “diol” refers to a compound with two OH groups.

[0031] The term “(meth)acrylate” means acrylate or methacrylate. Likewise, the term (meth)acrylic acid” refers to methacrylic acid and / or acrylic acid and the term “(meth)acrylamide” refers to methacrylamide and / or acrylamide. Likewise, the term “(meth)allyl group” refers to a methallyl group and / or an allyl group.

[0032] The term “polyester” refers to repeating difunctional polymer wherein the repeat units are joined by ester linkages. Ester groups have the general formula -R — C(O) — OR’. The term “polyether” refers to repeating difunctional alkoxy radicals having the general formula -O-R-. Preferred R and R’ groups have the general formula -CJ / hn- and include, for example, methylene, ethylene and propylene (including n-propylene and i-propylene) or a combination thereof. Combinations of R and R’ groups may be provided, for example, as random or block type copolymers.

[0033] The term “polyol” refers to a compound with two or more hydroxyl (i.e., OH) groups.

[0034] The term “polymeric material” refers to any homopolymer, copolymer, terpolymer, and the like, as well as any diluent.

[0035] The term “substantially”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 10% for quantifiable properties) but again without requiring absolute precision or a perfect match. Terms such as same, equal, uniform, constant, strictly, and the like, are understood to be within the usual tolerances or measuring error applicable to the specific circumstance rather than requiring absolute precision or a perfect match.

[0036] By definition, the total weight percentages of all ingredients in a composition equals 100 weight percent.

[0037] As used herein, “adjacent” encompasses both in direct contact (e.g., directly adjacent) and having one or more intermediate layers present between the adjacent materials.

[0038] The term “film” or “layer” refers to a single stratum within a multilayer film or article.

[0039] The term “substrate” encompasses films, layers, and articles.

[0040] As used herein, “thickness” refers to the smallest dimension of a film or layer, e.g., in a z-axis while a major surface of the film or layer is in the x- and y-axes. Thickness may be determined using a micrometer gauge or doing a microscopic analysis of a cross-sectional sample of a layer or a multilayer composition.

[0041] The term “pressure-sensitive adhesive” or “PSA” is used in its conventional manner according to the Pressure-Sensitive Tape Council, which states that pressure-sensitive adhesives are known to possess properties including the following: (1) aggressive and permanent tack, (2) adherence with no more thanfinger pressure, (3) sufficient ability to hold onto an adherend, and (4) sufficient cohesive strength to be removed cleanly from the adherend. Materials that have been found to function well as PSAs include polymers designed and formulated to exhibit the requisite viscoelastic properties resulting in a desired balance of tack, peel adhesion, and shear holding power. PSAs are characterized by being normally tacky at room temperature (e.g., 20°C). Central to all PSAs is a desired balance of adhesion and cohesion that is often achieved by optimizing the physical properties of the elastomer, such as glass transition temperature and modulus. For example, if the glass transition temperature (Tg) or modulus of the elastomer is too high and above the Dahlquist criterion for tack (storage modulus of 3 x 106dynes / cm2at room temperature and oscillation frequency of 1 Hz), the material will not be tacky and is not useful by itself as a PSA material.

[0042] The term “glass transition temperature”, which can be written interchangeably as “Tg”, of a monomer refers to the glass transition temperature of the homopolymer formed from the monomer. The glass transition temperature for a polymeric material is typically measured by Dynamic Mechanical Analysis (“DMA”) at the maximum in tan delta (5).

[0043] The term “vinyl” refers to a polymerizable component that has a group CH2=CH- but that is not part of a (meth)acryloyl group.

[0044] Some advantages of using an optically clear adhesive (“OCA”) in optoelectronic devices may include, inter alia, an enhancement of the light extraction efficiencies between various optical components of the display and reduction of light scattering by mitigating refractive index mismatches at interfaces. As topographical features of optoelectronic device structures evolve into more complex geometries, there is an increasing demand for the development of highly compliant OCAs that can both adjust to these complex geometries as well as mitigate optical defects. However, once OCA film is integrated into the display, the OCA material should also be mechanically robust for the lifetime of the device in order to provide high mechanical stability and performance. One method of balancing these potentially opposing manufacturing requirements is through the use of a two-step UV curing process. Such two-step processes may allow for the UV process generation of an OCA having significant viscous character for compliance during lamination steps, followed by a UV-driven increase in the crosslinking density of the OCA after integration with the device.

[0045] For some applications, it may also be desirable for an OCA material to utilize UV-absorbing additives to protect any UV-sensitive components underneath the OCA layer. For example, hydroxyphenyl benzotriazole-based UV absorbers (e.g., TINUVIN 928 commercially available from BASF, Florham Park, New Jersey), which show high absorption below 380 nm wavelength of light, may be incorporated into OCAs to block UV light from reaching light-sensitive layers adjacent to the adhesive. However, this UV-absorbing function may intervene with one or both of the UV-based processes used to 1) generate the OCA; and 2) post-cure the OCA after lamination. The UV absorber in the OCA may block not only UV exposure from an end-user’s environment but may also block a significant portion of the UV spectrum used during the manufacturing of both the adhesive and display device. Reduced access to the post-lamination curing process not only limits the adhesive’s ability tobalance compliance with robust lifetime reliability but may also limit the adhesive and mechanical performance attributes of the OCA in general. Therefore, there is a need for technological development in OCA materials to incorporate UV-blocking functionality while retaining access to photopolymerization and photocuring mechanisms.

[0046] The present disclosure provides UV-absorbing and post-lamination curable compositions produced using a scheme that takes advantage of a combination of rapidly polymerizing acrylic monomers in conjunction with latent UV crosslinkers. This scheme allows for greater separation between the polymerization and crosslinking functions of the adhesive while concurrently allowing for the achievement of both functions in the presence of UV absorber additives.

[0047] Multilayer Compositions

[0048] In a first aspect, a multilayer composition is provided. The multilayer composition comprises a first layer comprising a first adhesive composition; a second layer comprising a (methjacrylate composition and a polymer additive distributed in the (methjacrylate composition; and a third layer comprising a second adhesive composition. A latent UV crosslinker is present in at least one of the first layer or the second layer. Further, a UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer.

[0049] Referring to FIG. 1, multilayer composition 100 comprises a first layer 110 comprising a first adhesive composition 111; a second layer 120 comprising a (methjacrylate composition 121 and a polymer additive 123 distributed in the (methjacrylate composition 121; and a third layer 130 comprising a second adhesive composition 131. A latent UV crosslinker present in at least one of the first layer or the second layer. A UV absorber (not shown) is present in at least one of the second layer 120 or the third layer 130. As can be seen in FIG. 1, the second layer 120 is disposed between the first layer 110 and the third layer 130. The second layer 120 has a first major surface 122 in contact with the first layer 110 and an opposing second major surface 124 in contact with the third layer 130.

[0050] It has unexpectedly been discovered that a polymer additive present in a core layer of a multilayer composition decreases diffusion of moieties present in different layers of the multilayer compositions; importantly, mitigating diffusion of latent UV crosslinkers and UV absorbers. Use of an additive enables simultaneous formation of the layers and does not involve the complexity of including a solid barrier (e.g., between fluid layers) to mitigate diffusion. In embodiments in which the multilayer composition is formed by coextrusion of three fluid layers, a desirably thinner multilayer composition may be produced than if the layers were separately laminated together or included a film layer in between fluid layers. In some preferred embodiments, when a UV absorber is present in the second layer, a latent UV crosslinker is present in the first layer.

[0051] Advantageously, the polymer additive can be selected such that optically clear compositions still exhibit a haze of 1.0% or less even with the polymer additive distributed in the second layer of the multilayer composition. For instance, the multilayer composition may exhibit a haze of 0.9% or less,0.8%, 0.7%, 0.6%, 0.5%, 0.4%, or even 0.3% or less. Haze may be determined according to the Haze Test described in detail in the Examples.

[0052] The various components of the multilayer compositions are described in detail below. Further, various additional optional components can be added to at least one of the first layer, the second layer, or the third layer, such as, for example, adhesion promoters (e.g., (3-glycidyloxypropyl)trimethoxysilane or (3-glycidyloxypropyl)triethoxysilane), colorants (e.g., titania or carbon black), dyes, corrosion inhibitors (e.g., benzotriazole), antistatic agents, plasticizers, thickeners, thixotropic agents, processing aides, nanoparticles, fibers, and combinations thereof. Generally, the amounts of each additive would depend on the intended use of the resulting composition.

[0053] In certain embodiments, one or more of the first adhesive composition, the (meth)acrylate composition, or the second adhesive composition is substantially acid-free. Being acid-free can be advantageous when one or more of the layers will be in contact with an acid-sensitive substrate during use.

[0054] First Layer

[0055] The first layer of the multilayer composition comprises a first adhesive composition that optionally comprises a latent UV crosslinker.

[0056] First Adhesive Composition

[0057] In some embodiments, the first adhesive composition comprises a partial reaction product of a polymerizable composition comprising at least one alkyl (meth)acrylate monomer, a hydroxy-functional monomer, and a photoinitiator.

[0058] Any suitable alkyl (meth)acrylate or mixture of alkyl (meth)acrylates can be used provided the glass transition temperature of the final (meth)acylate polymer is sufficiently low (e.g., no greater than 20°C). Some alkyl (meth)acrylate monomers can be classified as low Tgmonomers based on the glass transition temperature of the corresponding homopolymers. The low Tgmonomers, as measured from the corresponding homopolymers, often have a Tgno greater than 20°C, no greater than 10°C, no greater than 0°C, or no greater than -10°C.

[0059] Suitable low Tgalkyl (meth)acrylate monomers include, but are not limited to, non-tertiary alkyl acrylates but can be an alkyl methacrylate having a linear alkyl group with at least four carbon atoms. Specific examples of alkyl (meth)acrylates include, but are not limited to, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, sec -butyl acrylate, n-pentyl acrylate, 2-methylbutyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 4-methyl-2 -pentyl acrylate, 2- methylhexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, 2-octyl acrylate, isooctyl acrylate, isononyl acrylate, isoamyl acrylate, n-decyl acrylate, isodecyl acrylate, n-decyl methacrylate, lauryl acrylate, isotridecyl acrylate, n-octadecyl acrylate, isostearyl acrylate, n-dodecyl methacrylate, and combinations thereof. In some embodiments, the low Tgalkyl (meth)acrylate is selected from 2-ethylhexyl acrylate, isooctyl acrylate, n-butyl acrylate, 2-methylbutyl acrylate, 2-octyl acrylate, and combinations thereof. Other suitable monomers include branched long chain acrylates, such as those described in U.S. PatentNo. 8,137,807 (Clapper et al.). Additional suitable alkyl monomers include secondary alkyl acrylates, such as those described in U.S. Patent No. 9,102,774 (Clapper et al.).

[0060] Other alkyl (meth)acrylates that can be included in the polymerizable components are classified as high Tgmonomers based on the glass transition temperature of the corresponding homopolymers. The high Tgmonomers often have a Tggreater than 30°C, greater than 40°C, or greater than 50°C when homopolymerized (i.e., a homopolymer formed from the monomer has a Tggreater than 30°C, greater than 40°C, or greater than 50°C). Some suitable high Tgalkyl (meth)acrylate monomers include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl (meth)acrylate, cyclohexyl methacrylate, isobomyl (meth)acrylate, stearyl (meth)acrylate, and 3,3,5 trimethylcyclohexyl (meth)acrylate.

[0061] The amount of the alkyl (meth)acrylate can be any suitable amount up to 100 weight percent based on the total weight of the polymerizable components. The amount can be, for example, up to 99 weight percent, up to 95 weight percent, up to 90 weight percent, up to 85 weight percent, up to 80 weight percent, up to 75 weight percent, up to 70 weight percent, up to 65 weight percent, up to 60 weight percent, up to 55 weight percent, up to 50 weight percent, or up to 45 weight percent. The amount of the alkyl (meth)acrylate is often at least 35 weight percent, at least 40 weight percent, at least 45 weight percent, or at least 50 weight percent.

[0062] If the alkyl (meth)acrylate is selected to include high Tgmonomers, the amount of this monomer is often no greater than 40 weight percent based on the total weight of polymerizable components. That is, the amount can be in a range of 0 to 40 weight percent based on the total weight of polymerizable components. If higher amounts are used, the overall Tgof the (meth)acrylate polymer may be too high. The amount of the high Tgalkyl (meth)acrylate monomer is often no greater than 35 weight percent, no greater than 25 weight percent, or no greater than 15 weight percent. If present, the amount of the high Tgalky (meth)acrylate monomer is often at least 0.5 weight percent, at least 1 weight percent, at least 3 weight percent, at least 5 weight percent, or at least 10 weight percent. If the polymerizable component includes high Tgalkyl (meth)acrylate monomers, enough low Tgalkyl (meth)acrylate monomers is typically added to form a (meth)acylate polymer with a Tgno greater than 20°C.

[0063] The alkyl (meth)acrylate monomer is typically selected to include a low Tgmonomer such as those that have a Tgno greater than -10°C when measured as a homopolymer. For example, the polymerizable components often contain at least 40 weight percent, at least 45 weight percent, at least 50 weight percent, at least 55 weight percent, at least 60 weight percent, at least 65 weight percent, or at least 70 weight percent and up to 95 weight percent, up to 90 weight percent, up to 85 weight percent, up to 80 weight percent, up to 75 weight percent, or up to 70 weight percent low Tgmonomer having a Tgno greater than -10°C when measured as a homopolymer. The amount is based on the total weight of polymerizable components. Suitable alkyl monomers that have a Tgno greater than -10°C when measured as a homopolymer include, but are not limited to, 2-ethylhexyl acrylate, isooctyl acrylate, N- butyl acrylate, 2-methylbutyl acrylate, 2-octyl acrylate, and combinations thereof.

[0064] In some embodiments, the (meth)acrylate polymer is substantially free of acidic monomers. As used herein to describe acidic monomers, the term “substantially free” means that the (meth)acrylate polymer contains less than 1 weight percent, less than 0.5 weight percent, less than 0.2 weight percent, or less than 0.1 weight percent of these monomers. In some embodiments, the crosslinkable composition may be substantially free of acid in order to eliminate indium tin oxide (“ITO”) and metal trace corrosion that otherwise could damage touch sensors and their integrating circuits or connectors.

[0065] The (meth)acrylate polymer typically has a glass transition temperature no greater than 25 °C as determined by Dynamic Mechanical Analysis. For example, the glass transition temperature can be no greater than 20 °C, no greater than 15 °C, no greater than 10 °C, no greater than 5 °C, no greater than 0 °C, or no greater than -5 °C. The glass transition temperature is often greater than -55 °C, greater than - 40 °C, or greater than -30 °C.

[0066] In some preferred embodiments, the alkyl (meth)acrylate monomer may be selected from the group consisting of 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, hexyl acrylate, butyl acrylate, cyclohexyl acrylate, isobomyl (meth)acrylate, and combinations thereof.

[0067] Some exemplary photoinitiators suitable to assist in at least partially reacting a polymerizable composition are benzoin ethers (e.g., benzoin methyl ether or benzoin isopropyl ether) or substituted benzoin ethers (e.g., anisoin methyl ether). Other exemplary photoinitiators are substituted acetophenones such as 2,2-diethoxyacetophenone or 2, 2-dimethoxy-2 -phenylacetophenone (commercially available under the trade designation IRGACURE 651 from BASF Corp. (Florham Park, NJ, USA) or under the trade designation ESACURE KB-1 from Sartomer (Exton, PA, USA)). Still other exemplary photoinitiators are substituted alpha-ketols such as 2-methyl-2 -hydroxypropiophenone, aromatic sulfonyl chlorides such as 2-naphthalenesulfonyl chloride, and photoactive oximes such as 1 -phenyl- 1,2- propanedione-2-(O-ethoxycarbonyl)oxime. Other suitable photoinitiators may include, for example, 1- hydroxy cyclohexyl phenyl ketone (commercially available under the trade designation IRGACURE 184), phenylbis (2,4,6-trimethylbenzoyl) phosphineoxide (commercially available under the trade designation IRGACURE 819), l-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-l-propane-l-one (commercially available under the trade designation IRGACURE 2959), 2-benzyl-2-dimethylamino-l-(4- morpholinophenyl) butanone (commercially available under the trade designation IRGACURE 369), 2- methyl-l-[4-(methylthio)phenyl]-2-morpholinopropan-l-one (commercially available under the trade designation IRGACURE 907), diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, obtained from IGM Resins USA Inc., Charlotte, North Carolina, and 2 -hydroxy -2 -methyl- 1 -phenyl propan-l-one (commercially available under the trade designation DAROCUR 1173 from Ciba Specialty Chemicals Corp. (Tarrytown, NY, USA)).

[0068] Sensitizers may also be used to enhance the efficacy of the photoinitiators in certain embodiments. Useful sensitizers may include, for example, isopropylthioxanthone (available under the trade name OMNIRAD ITX) and 4-diethyl-9H-thioxanthen-9-one (available under the trade name OMNIRAD DETX), as well as other thioxanthones based sensitizers.

[0069] In some embodiments, a polymerizable composition further includes at least one hydroxyfunctional monomer. Examples of suitable hydroxy -functional monomers include for instance and without limitation, 2 -hydroxy ethyl (meth)acrylate, 2-hydroxy-propyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and the like. In some embodiments, the polymerizable composition includes between about 0 and about 40 parts by weight of the hydroxy-functional monomer, particularly between about 5 and about 35 parts, and more particularly between about 10 and about 30 parts.

[0070] In some embodiments, the polymerizable composition further comprises at least one non-hydroxy functional polar copolymerizable monomer. Examples of suitable non-hydroxy functional polar copolymerizable monomers include for instance and without limitation, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, ether functional monomers such as 2-ethoxyethyl (meth)acrylate, 2- ethoxyethoxyethyl (meth)acrylate, dimethylaminoethyl(meth)acrylate, nitrogen containing monomers such as acrylamide, methacrylamide, N-alkyl substituted and N,N-dialkyl substituted acrylamides or methacrylamides where the alkyl group has up to 3 carbons, and N-vinyl lactams. Examples of suitable substituted amide monomers include for instance and without limitation, N,N-dimethylacrylamide, N,N- diethyl acrylamide, N-morpholino (meth)acrylate, N-vinyl pyrolidone and N-vinyl caprolactam. In some embodiments, the polymerizable composition includes between about 0 and about 20 parts by weight of the polar copolymerizable monomer, particularly between about 1 and about 15 parts, and more particularly between about 1 and about 10 parts.

[0071] In some embodiments, the polymerizable composition may include at least one crosslinking monomer. It is to be understood that the crosslinking monomer excludes the latent UV crosslinkers. In some cases, suitable crosslinking monomers include multifunctional (meth)acrylate monomers.Examples of useful multifunctional (meth)acrylate monomers include, but are not limited to, di(meth)acrylates, tri(meth)acrylates, and tetra(meth)acrylates, such as, for example, 1,6 -hexanediol di(meth)acrylate, polyethylene glycol) di(meth)acrylates, polybutadiene di(meth)acrylate, polyurethane di(meth)acrylates, and propoxylated glycerin tri(meth)acrylate, and mixtures thereof. Useful isocyanate cross-linkers may include, for example, an aromatic triisocyanate available as DESMODUR N3300 (Bayer, Cologne, Germany). If used, the crosslinking monomer is typically used in an amount of at least 0.01, 0.02, 0.03, 0.04, or 0.05 up to 1, 2, 3, 4, or 5 parts by weight, relative to 100 parts by weight of the total monomer content.

[0072] Other crosslinking methods, such as ionic crosslinking, acid-base crosslinking, or the use of physical crosslinking methods, such as by copolymerizing high Tgmacromers, such as, for example, polymethylmethacrylate macromer or polystyrene macromer, may also be used. When included, macromers may be used in an amount of about 1 to about 20 parts by weight of the total monomer components.

[0073] Chain-transfer agents are optionally included in a polymerizable composition to control the molecular weight of the (meth)acrylate polymer. Suitable chain-transfer agents include, but are not limited to, those selected from the group of carbon tetrabromide, hexabromoethane, bromotrichloromethane, 2-mercaptoethanol, tert-dodecylmercaptan, isooctylthiogly coate, 3 -mercapto-1,2-propanediol, cumene, pentaerythritol tetrakis(3 -mercapto butyrate) (available under the trade name KARENZ MT PEI from Showa Denko), 1,4-bis (3-mercaptobutylyloxy) butane (available under trade name KARENZ MT BD1 from Showa Denko), ethylene glycol bisthioglycolate, and mixtures thereof. Depending on the reactivity of the chain-transfer agent selected, the amount of chain transfer agent is often in a range of 0 to 5 weight percent based on the total weight of monomers in the polymerizable composition. In some embodiments, the amount of the chain transfer agent is at least 0.05 weight percent, at least 0.1 weight percent, at least 0.2 weight percent, at least 0.3 weight percent, or at least 0.5 weight percent and can be up to 5 weight percent, up to 4.5 weight percent, up to 4 weight percent, up to 3.5 weight percent, up to 3 weight percent, up to 2.5 weight percent, up to 2 weight percent, up to 1.5 weight percent, or up to 1 weight percent. The weight percent values are based on the total weight of the polymerizable components.

[0074] Latent UV Crosslinker

[0075] Optionally, the latent UV crosslinker is present in the first layer. Suitable latent UV crosslinkers include for instance and without limitation, a benzophenone-based monomer, a benzophenone-based polymer, or a combination of at least one multifunctional acrylate with UV photoinitiator.

[0076] Exemplary suitable benzophenone-based monomers and -polymers include for instance and without limitation, 2,2'-dihydroxybenzophenone, 2,4'-dihydroxybenzophenone, 4- acryloyloxybenzophenone, 4-acryloyloxyethoxybenzophenone, 4-acryloyloxy-4 '-methoxybenzophenone, 4-acryloyloxyethoxy-4 '-methoxybenzophenone, 4-acryloy loxy-4 '-bromobenzophenone, 4- acryloyloxyethoxy-4'-bromobenzophenone, 4-methacryloyloxybenzophenone, 4- methacryloyloxyethoxybenzophenone, 4-methacryloyloxy-4'-methoxybenzophenone, 4- methacryloyloxyethoxy-4'-methoxybenzophenone, 4-methacryloyloxy-4'-bromobenzophenone, 4- methacryloyloxyethoxy-4'-bromobenzophenone, benzophenone, 4-methylbenzophenone, 2,4,6- trimethylbenzophenone, 4-methoxybenzophenone, benzoylbenzoic acid, methyl-o-benzoylbenzoate, 4- benzoyl-4'-methyldiphenyl sulfide, 4,4'-dihydroxybenzophenone, 4,4'-dichlorobenzophenone, diesters of carboxymethoxybenzophenone and polytetramethylene glycol (for example, Omnipol BP, IGM Resins B.V. (Waalwijk, Netherlands)), and polymers of benzophenone derivatives (for example, Omnipol 2702, IGM Resins B.V. (Waalwijk, Netherlands)).

[0077] Suitable multifunctional acrylates and UV photoinitiators are described above in detail with respect to the use of a polymerizable composition in the first adhesive composition. In the case of using a multifunctional acrylate and a photoinitiator as the latent UV crosslinker, the UV photoinitiator has to be selected to absorb at a substantially different wavelength or intensity than any photoinitiator used to initiate polymerization of the polymerizable composition.

[0078] In some cases, the latent UV crosslinker comprises a photoacid generator or a photobase generator. A photoacid generator photolyzes upon exposure to actinic radiation yielding an acid and a residue compound; a photobase generator photolyzes upon exposure to actinic radiation yielding a base and a residue compound.

[0079] Ionic photoacid generators are known, and reference may be made to K. Dietliker, Chemistry and Technology of UV and EB Formulation for Coatings, Inks and Paints, vol. Ill, SITA Technology Ltd., London, 1991. Further reference may be made to Crivello J.V. (1984) Cationic polymerization — lodonium and sulfonium salt photoinitiators, in Initiators — Poly -Reactions — Optical Activity, Advances in Polymer Science, vol 62, Springer, Berlin, Heidelberg. Optionally, a photoacid generator comprises an onium salt. Common photoacid generators are onium salts such as triarylsulfonium salts, diazonium salts, or diaryliodonium salts. In some embodiments, the photoacid generator comprises an iodonium salt, a sulfonium salt, a dialkyl-4-hydroxyphenyl sulfonium salt, or a combination thereof.

[0080] Photobase generators include any compounds which liberate amines upon exposure to light, typically at a wavelength of about 270 to 420 nanometers, however other wavelengths may be suitable. The photobase generator includes groups that include an oxime ester, a benzyl carbamate, a benzoin carbamate, an O-carbamoylhydroxyamines, an O-carbamoyloximes, an aromatic sulfonamide, an N- arylformamide, or an 4-(ortho-nitrophenyl)dihydropyridine.

[0081] Polymeric Additive

[0082] Optionally, a polymeric additive is also present in the first adhesive composition. Suitable polymeric additives include any one or more of the polymeric additives described in detail below with respect to the second layer. In cases where a polymeric additive is included in more than one layer, the specific polymer additives in the various layers may be the same or different.

[0083] In some cases, the first adhesive composition is an optically clear adhesive.

[0084] Second Layer

[0085] The second layer comprises a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition. Optionally, the second layer also comprises a latent UV crosslinker. Optionally, the second layer also comprises a UV absorber.

[0086] (Meth) acrylate Composition

[0087] In some embodiments, the (meth)acrylate composition comprises at least one alkyl (meth)acrylate monomer, a hydroxy -functional monomer, and a photoinitiator. Exemplary suitable alkyl (meth)acrylate monomers, hydroxy -functional monomers, and photoinitiators are described above in detail with respect to a polymerizable composition for the first adhesive composition. Any combination of the above alkyl (meth)acrylate monomers, hydroxy -functional monomers, and photoinitiators may optionally be used for the (meth)acrylate composition of the second layer and may be the same or different than specific components included in the polymerizable composition. In some cases, the (meth)acrylate composition is at least partially polymerized.

[0088] Polymer Additive

[0089] The polymer additive functions to mitigate diffusion of other components between layers of the multilayer composition. Suitable polymer additives include those that are sufficiently compatible with the (meth)acrylate composition to remain distributed in the (meth)acrylate composition. Preferably, the use of a polymer additive does not significantly increase the haze of the resulting multilayer composition.In some embodiments, the polymer additive comprises at least one co-reactive group, for instance at least one acrylate group. In certain cases, the polymer additive comprises a block copolymer.

[0090] In certain embodiments, the polymer additive comprises a non-acrylic polymer functionalized with at least one pendant or telechelic (meth)acrylic group. In such cases, exemplary suitable non-acrylic polymers include for instance and without limitation, a polyvinyl acetal (e.g., polyvinyl butyral), a polyurethane, a polyester, a polysiloxane, a polyether, a synthetic rubber, or combinations thereof. The (meth)acrylic group(s) participate in polymerization with the (meth)acrylate composition, covalently bonding the polymer additive to the subsequently polymerized (meth)acrylate composition.

[0091] For example, some suitable (meth)acrylic group functionalized polyvinyl acetals are described in detail in PCT Application No. PCT / IB2024 / 057508 (Beagi et al.), including use of a polyvinyl acetal formed from a condensation reaction between polyvinyl alcohol and an aldehyde (typically formaldehyde). The polyvinyl acetal can be prepared by saponifying polyvinyl acetate to prepare polyvinyl alcohol and then acetalizing the polyvinyl alcohol with an aldehyde in the presence of a catalyst. The degree of saponification of the polyvinyl alcohol is not particularly limited, and is commonly within a range of 70 to 99.9 mol%, such as 80 to 99.8 mol%. Further, pendant methacrylate functionalization of a polyvinyl butyral is described in the Examples below. Advantageously, a functionalized polyvinyl acetal also imparts high modulus physical properties to the multilayer construction as well as decreasing diffusion of other components between layers of the multilayer construction.

[0092] Some suitable polyurethanes include for instance those formed using a polyester polyol that is a dimerized fatty acid-based polyester polyol. Such polyurethanes advantageously improve at least one physical property, for instance [the modulus and / or toughness, of the multilayer construction as well as decreasing diffusion of other components between layers of the multilayer constmction.

[0093] Some suitable polyesters include for instance and without limitation, polyethylene terephthalate (PET), polyethylene terephthalate (PBT), polylactic acid (PLA), polyhydroxybutyrate (PHB), polytrimethylene terephthalate (PTT), polyethylene terephthalate glycol (PETG), polycarbonate (PC), and combinations thereof.

[0094] Some suitable polysiloxanes include for instance and without limitation, polydimethylsiloxane (PDMS), poly methylhydro siloxane (PMHS), polymethylphenylsiloxane (PMPS), polydiphenylsiloxane (PDPS), polymethylvinylsiloxane (PMVS), polydiphenylsiloxane (PDPS), polydimethyl-co- methylvinylsiloxane (PDMVS), and combinations thereof.

[0095] Some suitable polyethers include for instance and without limitation, polyoxymethylene (POM), polyphenylene oxide (PPO), polyetherketone (PEK), polyetheretherketone (PEEK), epoxy resins, polyethylene oxide polymer and copolymers, polypropylene oxide polymers or copolymers, polytetrahydrofuran, and combinations thereof.

[0096] Some suitable synthetic rubbers include for instance and without limitation, butyl rubber, synthetic polyisoprene rubber, ethylene-propylene mbber, ethylene -propylene- diene mbber,polybutadiene rubber, polyisobutylene mbber, poly(alpha-olefin) rubber, nitrile rubber, and styrene - butadiene rubber, and combinations thereof.

[0097] In certain embodiments, the polymer additive comprises an acid functional group, an aldehyde functional group, an anhydride functional group, an isocyanate functional group, an epoxy functional group, a hydroxyl functional group, an amine functional group, an amide functional group, or a halogen functional group. Such functional groups may be advantageous when the (meth)acrylate composition includes a functional group that is able to covalently bond the polymer additive to the subsequently polymerized (meth)acrylate composition and / or that is able to form hydrogen bonds and / or ionic bonds with the polymerized (meth)acrylate composition due to having complementary functional groups.

[0098] In select embodiments, the polymer additive is selected from the group consisting of a (meth)acrylic-functionalized polyvinyl acetal, a (meth)acrylic-functionalized polyurethane, an acrylic block copolymer, and combinations thereof.

[0099] Latent UV Crosslinker

[0100] Optionally, the latent UV crosslinker is present in the second layer. Suitable latent UV crosslinkers include for instance and without limitation, those described above in detail with respect to the first layer. It is expressly contemplated that when a latent UV crosslinker is included in both of the first layer and the second layer that the specific latent UV crosslinkers in the two layers may be the same or different.

[0101] UV Absorber

[0102] In certain embodiments, an ultraviolet (UV) absorber is present in the second layer. Useful UV absorbers may include an organic UV absorber, a dye (e.g., tartrazine (Fischer Scientific, Waltham, MA) and sodium copper chlorophyllin (TCI Chemicals, Tokyo, Japan), a pigment, a red shifted ultraviolet absorber, nanoparticles (e.g., inorganic nanoparticles), or any combination thereof.

[0103] In some cases, the UV absorber is selected from the group consisting of a benzotriazole, a substituted triazine, an oxazolic acid amide, a substituted benzophenone, derivatives thereof, and combinations thereof.

[0104] For instance, two suitable organic UV absorbers include commercial products such as, or 2-(2H- Benzotriazol-2-yl)-6-(l-methyl-l-phenylethyl)-4-(l, 1, 3, 3 -tetramethylbutyl) phenol (commercially available as TINUVIN 928) or “TINUVIN CARBOPROTECT”, both from BASF, (Florham Park, New Jersey).

[0105] The concentration of a UV absorber may be at least 0.25 wt.%, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or at least 5 wt.% of the composition (i.e., the (meth)acrylate composition of the second layer or the second adhesive composition of the third layer). The concentration of the UV absorber is typically no greater than 15 wt.%, 14, 13, 12, or 10 wt.%. In some preferred embodiments, the concentration of the UV absorber ranges from 0.3 pph to 5 pph with respect to the composition (i.e., the (meth)acrylate composition of the second layer or the second adhesive composition of the third layer).

[0106] In some embodiments, the inclusion of the ultraviolet absorber can reduce the transmission (e.g. of a 100 microns thick adhesive layer) at 380 nm and 385 nm to less than 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, or2%. In some preferred embodiments the UV absorber has lower than 15 % transmittance at 365 nm for a 0.1 mm thick coating. In some preferred embodiments the UV absorber has higher than 70 % transmittance at 420 nm for a 0.1 mm thick coating.

[0107] Exemplary suitable nanoparticles include carbon black, titanium dioxide, zinc oxide, cesium dioxide, zirconium dioxide, barium sulfate, or combinations thereof. These particular nanoparticles tend to be stable to ultraviolet radiation in addition to absorbing the radiation.

[0108] Some suitable red shifted UV absorbers (RUVAs) absorb at least 70% (in some embodiments, at least 80%, or even greater than 90%) of the UV light in the wavelength region from 180 nm to 430 nm. RUVAs typically have enhanced spectral coverage in the long-wave UV region, enabling it to block high wavelength UV light. One of the most effective RUVA is a benzotriazole compound, 5-trifluoromethyl- 2-(2-hydroxy-3-alpha-cumyl-5-tert-octylphenyl)-2H-benzotriazole (available under the trade designation “CGL-0139” from BASF). Other exemplary benzotriazoles include 2-(2 -hydroxy-3, 5-di-alpha- cumylphehyl)-2H-benzotriazole, 5-chloro-2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-2H-benzotiazole, 5-chloro-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H -benzotriazole, 2-(2 -hydroxy-3, 5-di-tert-amylphenyl)- 2H-benzotriazole, 2-(2 -hydroxy -3-alpha-cumyl-5-tert-octylphenyl)-2H-benzotriazole, 2-(3-tert-butyl-2- hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole. Further exemplary RUVAs includes 2(-4,6- diphenyl-l-3,5-triazin-2-yl)-5-hexyloxy-phenol. Other exemplary UV absorbers include those available from BASF under the trade designations “TINUVIN 1577,” “TINUVIN 900,” “TINUVIN 1600,” and “TINUVIN 777.” Other exemplary UV absorbers are available, for example, in a polyester master batch under the trade designation “TA07-07 MB” from Sukano Polymers Corporation, Dunkin, SC. An exemplary UV absorber for polymethylmethacrylate is a masterbatch available, for example, under the trade designation “TAI 1-10 MBO1” from Sukano Polymers Corporation.

[0109] In some cases, the second adhesive composition is an optically clear adhesive.

[0110] Third Layer

[0111] The third layer comprises a second adhesive composition and optionally a UV absorber.

[0112] Second Adhesive Composition

[0113] In some cases, the second adhesive composition comprises a partial reaction product of a polymerizable composition comprising at least one alkyl (meth)acrylate monomer, a hydroxy-functional monomer, and a photoinitiator. Exemplary suitable alkyl (meth)acrylate monomers, hydroxy -functional monomers, and photoinitiators are described above in detail with respect to a polymerizable composition for the first adhesive composition. Any combination of the above alkyl (meth)acrylate monomers, hydroxy -functional monomers, and photoinitiators may optionally be used for the second adhesive composition and may be the same or different than specific components included in the polymerizable composition of the first adhesive composition.

[0114] UV Absorber

[0115] In certain embodiments, a UV absorber is present in the third layer. Suitable UV absorbers include any one or more of the UV absorbers described in detail above with respect to the second layer.In cases where a UV absorber is included in each of the second layer and the third layer, the specific UV absorbers in the two layers may be the same or different.

[0116] Polymeric Additive

[0117] Optionally, a polymeric additive is also present in the second adhesive composition. Suitable polymeric additives include any one or more of the polymeric additives described in detail above with respect to the second layer. In cases where a polymeric additive is included in more than one layer, the specific polymer additives in the various layers may be the same or different.

[0118] Methods

[0119] In a second aspect, a method of making a multilayer composition is provided. The method comprises coating a first solution, a second solution, and a third solution, thereby forming a multilayer composition. The multilayer composition comprises a first layer comprising a first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; and a third layer comprising a second adhesive composition. A latent UV crosslinker is present in at least one of the first layer or the second layer. Further, a UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer. It is noted that the first solution forms the first layer, the second solution forms the second layer, and the third solution forms the third layer. It is to be understood that there will be some intermingling between the adjacent layers due to the three solutions being in a fluid physical state at the time of coating.

[0120] In some embodiments, the first solution, the second solution, and the third solution are simultaneously coated, e.g., on a carrier such as a liner. In alternate embodiments, the three solutions are sequentially coated. By “sequential” is meant that the three solutions are not all coated at the same time; however, no particular order is required and two of the solutions may be coated at the same time.Further, “sequential” encompasses two of the solutions being separately coated at the same time, for instance coated onto separate carriers.

[0121] In some cases including sequential coating, a first solution may be coated on a first carrier (e.g., a liner) and a third solution may be coated on a second carrier (e.g., a liner), then a second solution may be coated on top of either the first solution or the third solution. Next, the construction may be laminated together to form a multilayer composition having five layers having an order of the first carrier / the first layer / the second layer / the third layer / the second carrier. In select embodiments, the first solution, the third solution, or both, may undergo partial polymerization prior to the deposition of the second solution.

[0122] In some embodiments, the method further includes exposing at least one of the first solution, the second solution, or the third solution to actinic radiation prior to the coextruding. Such exposure can result in at least partial polymerization of the first adhesive composition, the (methjacrylate composition, and / or the second adhesive composition. Any one or more of the three solutions may be exposed to actinic radiation before coextruding the solutions. Any form of actinic radiation may be used, i.e., radiation that leads to the production of photochemical activity. For example, actinic radiation maycomprise radiation of from about 250 nm to about 700 mu. In some cases, a wavelength range is selected to have little to no overlap with wavelengths at which the latent UV crosslinker has substantial absorption to minimize premature crosslinking. In some cases, a UV intensity is selected that initiates at least partial polymerization without activating the latent UV crosslinker. Sources of actinic radiation include tungsten halogen lamps, xenon and mercury arc lamps, incandescent lamps, germicidal lamps, fluorescent lamps, lasers and light emitting diodes. UV-radiation can be supplied using a high intensity continuously emitting system such as those available from Fusion UV Systems.

[0123] It is expressly contemplated that the multilayer composition formed by a method according to this aspect may be any multilayer composition described in detail above with respect to the first aspect. For instance, the components of each of the first layer, the second layer, and the third layer include any of the above-described components of the three layers that are detailed in the first aspect.

[0124] In a third aspect, a method of making a multilayer adhesive composition is provided. The method comprises exposing to UV radiation a multilayer composition according to any embodiment of the first aspect described in detail above. The UV radiation, often between about 240 nm and 460 nm, is selected to initiate the latent UV crosslinker for crosslinking of at least the first adhesive composition. In some cases, the second adhesive composition is also crosslinked, for instance due to the inclusion of a multifunctional (meth)acrylate monomer in the composition.

[0125] Multilayer Adhesive Compositions

[0126] In a fourth aspect, a multilayer adhesive composition is provided. The multilayer adhesive composition comprises a first layer comprising a crosslinked first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; and a third layer comprising a second adhesive composition. Further, UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer.

[0127] Referring to FIG. 2, multilayer composition 200 comprises a first layer 210 comprising a crosslinked first adhesive composition 211; a second layer 220 comprising a (meth)acrylate composition 221 and a polymer additive 223 distributed in the (meth)acrylate composition 221; and a third layer 230 comprising a second adhesive composition 231. A UV absorber (not shown) is present in at least one of the second layer 220 or the third layer 230. As can be seen in FIG. 2, the second layer 220 is disposed between the first layer 210 and the third layer 230. The second layer 220 has a first major surface 222 in contact with the first layer 210 and an opposing second major surface 224 in contact with the third layer 230.

[0128] In some embodiments, the multilayer adhesive composition exhibits a 180 degree peel of 3.0 Newtons per centimeter (N / cm) or greater at 25 degrees Celsius, as determined by the 180 Peel on Glass Test Method, such as 3.5 N / cm, 4.0 N / cm, 4.5 N / cm, 5.0 N / cm, 5.5 N / cm, 6.0 N / cm, 6.5 N / cm, 7.0 N / cm, 7.5 N / cm, 8.0 N / cm, 8.5 N / cm, 9.0 N / cm, 9.5 N / cm, or 10.0 N / cm, or greater, as determined by the 180Degree Peel Test Method. Typically, a maximum 180 degree peel exhibited by a multilayer adhesive composition according to various embodiments of the present disclosure is 20.0 N / cm.

[0129] Preferably, the multilayer adhesive composition exhibits a haze of 1.0% or less, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, or even 0.3% or less. Haze may be determined according to the Haze Test described in detail in the Examples. Such a low haze helps enable the multilayer adhesive composition to be used as an optically clear adhesive.

[0130] The multilayer adhesive composition may be deposited onto substrates at useful thicknesses ranging from 50 micrometers to 10000 micrometers, 100 micrometers to 5000 micrometers, or 250 micrometers to 1000 micrometers. Useful substrates can be of any nature and composition, and can be inorganic or organic. Representative examples of useful substrates include ceramics, siliceous substrates including glass, metal (e.g., aluminum or steel), natural and man-made stone, woven and nonwoven articles, polymeric materials, including thermoplastic and thermosets, (such as polymethyl (meth)acrylate, polycarbonate, polystyrene, styrene copolymers, such as styrene acrylonitrile copolymers, polyesters, polyethylene terephthalate), silicones, paints (such as those based on acrylic resins), powder coatings (such as polyurethane or hybrid powder coatings), and wood; and composites of the foregoing materials.

[0131] Select Embodiments of the Disclosure

[0132] In a first embodiment, the present disclosure provides a multilayer composition. The multilayer composition comprises a first layer comprising a first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; and a third layer comprising a second adhesive composition. A latent UV crosslinker is present in at least one of the first layer or the second layer. A UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer.

[0133] In a second embodiment, the present disclosure provides a multilayer composition according to the first embodiment, wherein the UV absorber is present in the third layer.

[0134] In a third embodiment, the present disclosure provides a multilayer composition according to the first embodiment or the second embodiment, wherein the UV absorber is present in the second layer.

[0135] In a fourth embodiment, the present disclosure provides a multilayer composition according to any of the first through third embodiments, wherein the polymer additive comprises at least one coreactive group.

[0136] In a fifth embodiment, the present disclosure provides a multilayer composition according to any of the first through fourth embodiments, wherein the polymer additive comprises at least one acrylate group.

[0137] In a sixth embodiment, the present disclosure provides a multilayer composition according to any of the first through fourth embodiments, wherein the polymer additive comprises a non-acrylic polymer functionalized with at least one pendant or telechelic (meth)acrylic group.

[0138] In a seventh embodiment, the present disclosure provides a multilayer composition according to the sixth embodiment, wherein the non-acrylic polymer comprises a polyvinyl acetal, a polyurethane, a polyester, a polyether, a polysiloxane, a synthetic rubber, or combinations thereof.

[0139] In an eighth embodiment, the present disclosure provides a multilayer composition according to any of the first through fourth embodiments, wherein the polymer additive comprises an acid functional group, an aldehyde functional group, an anhydride functional group, an isocyanate functional group, an epoxy functional group, a hydroxyl functional group, and amine functional group, an amide functional group, or a halogen functional group.

[0140] In a ninth embodiment, the present disclosure provides a multilayer composition according to any of the first through third embodiments, wherein the polymer additive comprises a block copolymer.

[0141] In a tenth embodiment, the present disclosure provides a multilayer composition according to any of the first through ninth embodiments, wherein the polymer additive is selected from the group consisting of a (meth)acrylic -functionalized polyvinyl acetal, a (meth)acrylic-functionalized polyurethane, an acrylic block copolymer, and combinations thereof.

[0142] In an eleventh embodiment, the present disclosure provides a multilayer composition according to the tenth embodiment, wherein the polyurethane of the (meth)acrylic -functionalized polyurethane was formed using a polyester polyol that is a dimerized fatty acid-based polyester polyol.

[0143] In a twelfth embodiment, the present disclosure provides a multilayer composition according to the tenth embodiment, wherein the polyvinyl acetal of the (meth)acrylic-functionalized polyvinyl acetal was formed using 20 weight percent (wt.%) or less of polyvinyl alcohol.

[0144] In a thirteenth embodiment, the present disclosure provides a multilayer composition according to any of the first through twelfth embodiments, wherein the first adhesive composition is an optically clear adhesive.

[0145] In a fourteenth embodiment, the present disclosure provides a multilayer composition according to any of the first through thirteenth embodiments, wherein the first adhesive composition comprises a partial reaction product of a polymerizable composition comprising at least one alkyl (meth)acrylate monomer, a hydroxy -functional monomer, and a photoinitiator.

[0146] In a fifteenth embodiment, the present disclosure provides a multilayer composition according to the fourteenth embodiment, wherein the polymerizable composition further comprises at least one nonhydroxy functional polar copolymerizable monomer.

[0147] In a sixteenth embodiment, the present disclosure provides a multilayer composition according to the fourteenth embodiment or the fifteenth embodiment, wherein the first adhesive composition further comprises at least one crosslinking monomer.

[0148] In a seventeenth embodiment, the present disclosure provides a multilayer composition according to any of the first through sixteenth embodiments, wherein the second adhesive composition is an optically clear adhesive.

[0149] In an eighteenth embodiment, the present disclosure provides a multilayer composition according to the seventeenth embodiment, wherein the second adhesive composition comprises a partial reactionproduct of a polymerizable composition comprising at least one alkyl (meth)acrylate monomer, a hydroxy -functional monomer, and a photoinitiator.

[0150] In a nineteenth embodiment, the present disclosure provides a multilayer composition according to any of the first through eighteenth embodiments, wherein the (meth)acrylate composition comprises at least one alkyl (meth)acrylate monomer, a hydroxy -functional monomer, and a photoinitiator.

[0151] In a twentieth embodiment, the present disclosure provides a multilayer composition according to the nineteenth embodiment, wherein the (meth)acrylate composition is at least partially polymerized.

[0152] In a twenty -first embodiment, the present disclosure provides a multilayer composition according to any of the first through twentieth embodiments, wherein the UV absorber is selected from the group consisting of a benzotriazole, a substituted triazine, an oxazolic acid amide, a substituted benzophenone, derivatives thereof, and combinations thereof.

[0153] In a twenty-second embodiment, the present disclosure provides a multilayer composition according to any of the first through twenty -first embodiments, wherein the latent UV crosslinker comprises at least one of a benzophenone-based monomer, a benzophenone-based polymer, or a combination of at least one multifunctional acrylate with UV photoinitiator.

[0154] In a twenty -third embodiment, the present disclosure provides a multilayer composition according to any of the first through twenty -second embodiments, wherein at least one of the first adhesive composition or the second adhesive composition is substantially acid-free.

[0155] In a twenty -fourth embodiment, the present disclosure provides a multilayer composition according to any of the first through twenty -third embodiments, wherein at least one of the first layer, the second layer, or the third layer further comprises at least one additive selected from the group consisting of an adhesion promoter, a pigment, a dye, a corrosion inhibitor, an antistatic agent, a plasticizer, a thickener, a thixotropic agent, a processing aide, a plurality of nanoparticles, a plurality of fibers, and combinations thereof.

[0156] In a twenty -fifth embodiment, the present disclosure provides a multilayer composition according to any of the first through twenty -fourth embodiments, exhibiting a haze of 1.0% or less.

[0157] In a twenty-sixth embodiment, the present disclosure provides a multilayer composition according to any of the first through twenty -fifth embodiments, wherein the latent UV crosslinker is present in the first layer.

[0158] In a twenty-seventh embodiment, the present disclosure provides a multilayer composition according to any of the first through twenty-sixth embodiments, wherein the latent UV crosslinker is present in the second layer.

[0159] In a twenty -eighth embodiment, the present disclosure provides a multilayer composition according to any of the first through twenty-seventh embodiments, wherein the first adhesive composition further comprises a polymer additive.

[0160] In a twenty -ninth embodiment, the present disclosure provides a multilayer composition according to any of the first through twenty -eighth embodiments, wherein the second adhesive composition further comprises a polymer additive.

[0161] In a thirtieth embodiment, the present disclosure provides a method of making a multilayer composition. The method comprises coating a first solution, a second solution, and a third solution, thereby forming a multilayer composition. The multilayer composition comprises a first layer comprising a first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; and a third layer comprising a second adhesive composition. A latent UV crosslinker is present in at least one of the first layer or the second layer. A UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer.

[0162] In a thirty -first embodiment, the present disclosure provides a method of making a multilayer composition according to the thirtieth embodiment, wherein the coating of the first solution, the second solution, and the third solution is simultaneous.

[0163] In a thirty-second embodiment, the present disclosure provides a method of making a multilayer composition according to the thirtieth embodiment, wherein the coating of the first solution, the second solution, and the third solution is sequential.

[0164] In a thirty -third embodiment, the present disclosure provides a method of making a multilayer composition according to any of the thirtieth through thirty-second embodiments, further comprising exposing at least one of the first solution, the second solution, or the third solution to actinic radiation prior to the coating.

[0165] In a thirty -fourth embodiment, the present disclosure provides a method of making a multilayer composition according to any of the thirtieth through thirty -third embodiments, wherein the multilayer composition is according to any of the first through twenty -ninth embodiments.

[0166] In a thirty -fifth embodiment, the present disclosure provides a method of making a multilayer adhesive composition, comprising exposing the multilayer composition according to any of the first through twenty -ninth embodiments to UV radiation.

[0167] In a thirty-sixth embodiment, the present disclosure provides a multilayer adhesive composition comprising a first layer comprising a crosslinked first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; and a third layer comprising a second adhesive composition. A UV absorber is present in at least one of the second layer or the third layer. The second layer is disposed between the first layer and the third layer

[0168] In a thirty-seventh embodiment, the present disclosure provides a multilayer adhesive composition according to the thirty-sixth embodiment, wherein the second adhesive composition is crosslinked.

[0169] In a thirty -eighth embodiment, the present disclosure provides a multilayer adhesive composition according to the thirty-sixth embodiment or the thirty-seventh embodiment, exhibiting a haze of 1.0% or less.

[0170] In a thirty -ninth embodiment, the present disclosure provides a multilayer adhesive composition according to any of the thirty-sixth through thirty -eighth embodiments, exhibiting a 180 Peel on Glass at 25 degrees Celsius of 3.0 Newtons per centimeter (N / cm) or greater.EXAMPLES

[0171] Unless otherwise noted or readily apparent from the context, all parts, percentages, ratios, etc. in the Examples and the rest of the specification are by weight. Table 1 (below) lists materials used in the examples and their sources. In the Tables, "NA" means not applicable. In the examples:Table 1. Materials List

[0172] Preparatory Example PVB 0.65-Pendant Methacrylate

[0173] Polyvinylbutyral (PVB) is used as an important polymer additive in the core layer of the composite constructions. It has the ability to generate high modulus physical properties for the core layer as well as serves to decrease diffusion between the latent UV crosslinker in the top skin layer and the UV absorber additives in the bottom skin layer of the three-layer embodiment. To aid in the reactive compatibilization of the acrylate monomer in the core layer and the PVB polymer additive, pendant methacrylate functionalization of a specific grade of PVB was undertaken as shown below:

[0174] 425 grams (g) of 30HH grade PVB was blended with 2075 g of 2EHA in a vessel utilizing a mixing blade and applied heat. This solution was mixed for 90 minutes at a temperature of approximately 50°C until the PVB was well solvated by the 2EHA. 0.125 g of DBT was added and allowed to mix for 10 minutes. 2.76 g of IEM was added to the vessel and the solution was mixed for 20 hours at a temperature of approximately 60°C.

[0175] Preparatory Example PUR 764-3

[0176] Similar to PVB, polyurethane resin was also utilized as a polymer addition to the core layer construction. PUR was synthesized to be compatible and co-reactive with the acrylic monomercomposition of the core constructions and plays a key role in both the physical properties of this layer and in controlling the diffusion of key constituents (UV crosslinker and UV absorbers) between each skin layer. The stmcture of the PUR having telechelic methacrylate functionality is shown below:

[0177] To a resin reaction vessel equipped with a mechanical stirrer, a condenser, and an air inlet, 291.82 g of Priplast 3196 (Croda Inc, Edison, NJ), 27.0 g of Desmodur W (Covestro LLC, Pittsburgh, PA), 0.16 g of XK-651(King Industries, Norwalk, CT), 0.06 g of BHT (TCI America, Portland, OR) and 50 g of MEK (EMD Millipore Corporation, Burlington, MA)were added. The solution was heated up to 75°C while stirring. The temperature was maintained at 75±2°C until the NCO content reached the theoretical NCO value, which was determined by utilizing a standard dibutylamine back titration method. Upon obtaining the theoretical NCO value, the polyurethane was then end capped by adding 3.14 g of HEMA (2 -hydroxyethyl methacrylate, TCI, Tokyo, JP). During the reaction, an additional 100 g of MEK was added to dilute the viscosity of the mixture. After the reaction was completed, 322 g of 2-EHA was added, followed by the evaporation of MEK through a Rotavapor to obtain a polyurethane (meth)acrylate (IV = 0.71) in 2EHA (BASF, Ludwigshafen, Germany) with a weight ratio of 1: 1.

[0178] Preparatory Coating Solutions for Outer Composite Layers

[0179] Preparatory coating solutions S1-S6 were prepared according to the formulations listed below in Table 2. The components as denoted by part A were charged to a quart glass jar, purged with nitrogen for 300 seconds, and then irradiated with 365 nm irradiation with an intensity of 0.3 mW / cm2until the solution reached a viscosity of about 500-3000 centipoises as measured by a Brookfield viscometer (Brookfield AMETEK, Middleboro, MA). Following this step, the additional components denoted in part B were added to the solutions and mixed thoroughly.

[0180] Table 2. Coating Solutions for Outer Composite LayersPreparatory Coating Solutions for Core Composite Lavers

[0181] Preparatory coating solutions Cl, C3, C6, and C9 were prepared according to the formulations listed below in Tables 3 A and 3B. The components as denoted by part A were charged to a quart glass jar, purged with nitrogen for 300 seconds, and then irradiated with 365 nm UV irradiation with an intensity of 0.3 mW / cm2until the solution reached a viscosity of about 500-3000 centipoises as measured by a Brookfield viscometer. Following this step, the additional components denoted part B were added to the solutions and mixed thoroughly.

[0182] Preparatory coating solutions C2, C4, C5, C7, C8, CIO, and Cll were prepared by combining all components in part A and part B together until thoroughly mixed and did not require the UV processing step as described above for C2 as an example.Table 3 A. Preparatory Coating Solutions for Core Composite LayersTable 3B. Preparatory Coating Solutions for Core Composite Layers

[0183] Preparation of Composite Multi-layer Optical Adhesives

[0184] Coating solutions were combined and coated into the target multilayer composite adhesives as indicated in Table 4 below. For examples utilizing simultaneous coating (SC) methods, the solutions were coated in a set up similar to that described in EP305161 A3 : 3M “Unified Pressure Sensitive Adhesive”. A die with three cavities, each fed with a separate reservoir and pump deposited the multilayer construction between siliconized PET release liners SKC RF02N and SKC RF22N (SKC Haas, KR). Pump rates were used to control target caliper for each layer as indicated in Table 4. Constructions were cured down line using a UV irradiation dose of approximately 12,600 mJ / cm2at a wavelength of approximately 405 nm.

[0185] Multilayer constructions generated through the lamination and indicated by “Lam” process were made using the same equipment. However, each layer was coated and UV irradiated separately as opposed to the simultaneous three-layer coating. Each individual layer was then stripped of its release liner and laminated together under hand roller pressure to form the three-layer composite.Table 4. Examples 1-9 and Comparative Examples 1-4

[0186] Haze Test

[0187] Haze measurements were made using a HunterLab (Reston, VA) UltrascanPro Spectrophotometer in transmission mode. 100 micrometer adhesive composites between siliconized PET were prepared as described above. One of the carrier liners was removed and the sample was laminated to a clear piece of 0.7 mm thick LCD glass (Swift Glass, Elmira Heights, New York). The sample was placed in the UltrascanPro Spectrophotometer to measure transmission and % Haze through the OCA / glass assembly.

[0188] Dynamic Mechanical Analysis (DMA)

[0189] Dynamic mechanical analysis was used to probe the modulus as a function of temperature as well as to determine the glass transition temperature (Tg) of the material. 100 micrometer adhesive composites between siliconized PET were prepared as described above. One liner was removed, and the adhesive was layered to a thickness of approximately 1000 micrometers. An 8 mm diameter by about 1-mm thick disk of laminated assembly layers was placed between the probes of a DHR parallel plate rheometer (TA Instruments, New Castle, DE). A temperature scan was performed by ramping from -45°C to 150°C at 3°C / minute. During this ramp, the sample was oscillated at a frequency of 1 Hz and a strain of approximately 0.4%. The shear storage modulus (G’), loss modulus (G”) and tan delta was recorded at select temperatures during this scan. The Tgof the material was also determined as the peak in the tan delta vs. temperature profile. In particular, the tan delta intensity at a set temperature of 70°C was utilized to approximate the degree of crosslinking within the sample elastomer. Furthermore, the differential between the Tan Delta before and after applying a UV dose to the adhesive or multilayer composite adhesive divided by the initial Tan Delta measurement before applying the full UV dose was utilized to calculate the extent of the ability of the composite to crosslink and cure.

[0190] 180 Peel on Glass Test

[0191] 100 micrometer adhesive composites between siliconized PET were prepared as described above. The first liner was stripped away and the OCA was laminated to plasma treated PET liner. A 0.5 inch (1.27 centimeter (cm)) by 6 inch (15.24 cm) strip was cut from this construction, the second release liner was removed, and the strip was laminated to the air side of a standard float glass plate using a 4.5 pound roller. The construction of glass / OCA / PET was placed in an autoclave with applied settings of 50°C and 5 kilograms of pressure for 20 minutes. The sample was then aged for over 12 hours in an environment of 25°C and 55% humidity prior to testing. Peel adhesion force was acquired using an I- mass SP2100 peel tester (Strongsville, OH) with a 10 N load cell. Peel tests were conducted with approximately a 180 degree angle of the debonding substrate with respect to the glass substrate and at a rate of approximately 6 cm / minute.Table 5 A, Performance of Examples 1-9 and Comparative Examples 1-4Table 5B. Performance of Examples 1-8 and Comparative Examples 1-2

[0192] As denoted in Tables 5A and 5B above, all examples and comparative examples exhibited a degree of UV blocking functionality as indicated by a reduction in transmitted light through the adhesive at a wavelength of 380 nm as compared to 420 nm. All examples showed a degree of optical clarity with haze values under 1%. However, Comparative Example 2 (CE2) exhibits undesirably higher haze due to an excess loading of acrylic block copolymer in the core layer that likely becomes incompatible with the majority and random acrylic copolymer composition in Core C7 (Table 4). Similarly, if the PVB polymer additive does not have the pendant methacrylate functionality as in the case of CE4 (Core Cl 1 of Table 4), the composite will also exhibit higher than 1% haze.

[0193] 180 degree peel on glass demonstrates the benefit of co-extruding multiple layers and curing simultaneously (CE1, EX3, and EX9) as opposed to individually coating / curing the layers and then laminating the layers together (CE3 and CE4). The systems utilizing the simultaneous coating method and then simultaneous curing process have significantly higher peel strength compared to the laminated samples in which the interlayer adhesion strength between the layers is likely the weakest link. However, simultaneous coating of solutions has the greatest risk of diffusion and migration of both the latent UV crosslinkers and UV absorbers in both top and bottom outer layers, respectively. Advantageously, at least certain embodiments of the present disclosure provide mitigated diffusion while also taking advantage of the excellent interlayer strength generated from the simultaneous coating method (followed by the simultaneous curing process). Moreover, the addition of particular polymeric additives to the coating solutions prior to UV curing can help to mitigate this diffusion as well as retain the functionality of each layer of the target multilayer adhesive composition.

[0194] The mitigation of diffusion and retention of layer functionality can be assed in one manner by the efficiency of the latent UV crosslinking of the top (e.g., first) layer. As described above, the diffusion of UV absorber into the top outer layer is particularly limiting as the absorbers diffusing upwards from the core layer and / or bottom layer will prevent the necessary degree of UV activation of latent crosslinkers in the top layer, inhibiting this important function for adhesive robustness and device reliability. To measure the extent of crosslinking during different stages of cure, the Tan Delta parameter was utilized representing the ratio of viscous to elastic contribution in the adhesive composite. Thus, lower Tan Delta measurements generally indicate a more crosslinked network and greater elastic behavior. Furthermore, the sensitivity of this measurement has proven to be a useful method to compare the degree of crosslinking between different elastomer systems indirectly using bulk mechanical analysis.

[0195] The differential between the Tan Delta before and after applying a UV dose to the adhesive or multilayer adhesive composition was utilized to gauge the efficiency of the ability of the composite to crosslink and cure. Typically, the UV cure elicits a lower Tan Delta value and thus, the percent reduction of the Tan Delta measurement with application of UV irradiation was used to indicate the effectiveness of the cure mechanism within the adhesive composition. In Examples with polymeric additives in the coextmded solutions, the percent reduction of Tan Delta is high (>25%) in most cases and remains high even upon the aging of the composite, suggesting that little to no diffusion of the UV absorbers in the bottom skin layer. However, in Comparative Example 1, in which there is no additional polymericadditive utilized in the co-extruded core solution layer (Cl of Table 4), not only does the reduction in Tan Delta start below 25%, but also drops to under 10% after aging suggesting much greater diffusion of UVAs into the UV curable layer and an undesirable decrease in cure functionality.

[0196] Other modifications and variations to the present disclosure may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present disclosure, which is more particularly set forth in the appended claims. It is understood that aspects of the various embodiments may be interchanged in whole or part or combined with other aspects of the various embodiments. All cited references, patents, or patent applications in the above application for letters patent are herein incorporated 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. The preceding description, given in order to enable one of ordinary skill in the art to practice the claimed disclosure, is not to be construed as limiting the scope of the disclosure, which is defined by the claims and all equivalents thereto.

Claims

What is claimed is:

1. A multilayer composition comprising: a first layer comprising a first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; a third layer comprising a second adhesive composition; a latent UV crosslinker present in at least one of the first layer or the second layer; and a UV absorber present in at least one of the second layer or the third layer; wherein the second layer is disposed between the first layer and the third layer.

2. The multilayer composition of claim 1, wherein the UV absorber is present in the third layer.

3. The multilayer composition of claim 1 or claim 2, wherein the UV absorber is present in the second layer.

4. The multilayer composition of any of claims 1 to 3, wherein the polymer additive comprises at least one co-reactive group.

5. The multilayer composition of any of claims 1 to 4, wherein the polymer additive comprises at least one acrylate group.

6. The multilayer composition of any of claims 1 to 4, wherein the polymer additive comprises a non-acrylic polymer functionalized with at least one pendant or telechelic (meth)acrylic group.

7. The multilayer composition of claim 6, wherein the non-acrylic polymer comprises a polyvinyl acetal, a polyurethane, a polyester, a polyether, a polysiloxane, a synthetic rubber, or combinations thereof.

8. The multilayer composition of any of claims 1 to 4, wherein the polymer additive comprises an acid functional group, an aldehyde functional group, an anhydride functional group, an isocyanate functional group, an epoxy functional group, a hydroxyl functional group, and amine functional group, an amide functional group, or a halogen functional group.

9. The multilayer composition of any of claims 1 to 3, wherein the polymer additive comprises a block copolymer.

10. The multilayer composition of any of claims 1 to 9, wherein the polymer additive is selected from the group consisting of a (meth)acry lic-functionalized polyvinyl acetal, a (meth)acrylic-functionalized polyurethane, an acrylic block copolymer, and combinations thereof.

11. The multilayer composition of claim 10, wherein the polyurethane of the (meth)acrylic- functionalized polyurethane was formed using a polyester polyol that is a dimerized fatty acid-based polyester polyol.

12. The multilayer composition of claim 10, wherein the polyvinyl acetal of the (meth)acrylic- functionalized polyvinyl acetal was formed using 20 weight percent (wt.%) or less of polyvinyl alcohol.

13. The multilayer composition of any of claims 1 to 12, wherein the first adhesive composition is an optically clear adhesive.

14. The multilayer composition of any of claims 1 to 13, wherein the first adhesive composition comprises a partial reaction product of a polymerizable composition comprising at least one alkyl (meth)acrylate monomer, a hydroxy -functional monomer, and a photoinitiator.

15. The multilayer composition of claim 14, wherein the polymerizable composition further comprises at least one non-hydroxy functional polar copolymerizable monomer.

16. The multilayer composition of claim 14 or claim 15, wherein the first adhesive composition further comprises at least one crosslinking monomer.

17. The multilayer composition of any of claims 1 to 16, wherein the second adhesive composition is an optically clear adhesive.

18. The multilayer composition of claim 17, wherein the second adhesive composition comprises a partial reaction product of a polymerizable composition comprising at least one alkyl (meth)acrylate monomer, a hydroxy -functional monomer, and a photoinitiator.

19. The multilayer composition of any of claims 1 to 18, wherein the (meth)acrylate composition comprises at least one alkyl (meth)acrylate monomer, a hydroxy -functional monomer, and a photoinitiator.

20. The multilayer composition of claim 19, wherein the (meth)acrylate composition is at least partially polymerized.

21. The multilayer composition of any of claims 1 to 20, wherein the UV absorber is selected from the group consisting of a benzotriazole, a substituted triazine, an oxazolic acid amide, a substituted benzophenone, derivatives thereof, and combinations thereof.

22. The multilayer composition of any of claims 1 to 21, wherein the latent UV crosslinker comprises at least one of a benzophenone-based monomer, a benzophenone-based polymer, or a combination of at least one multifunctional acrylate with UV photoinitiator.

23. The multilayer composition of any of claims 1 to 22, wherein at least one of the first adhesive composition or the second adhesive composition is substantially acid-free.

24. The multilayer composition of any of claims 1 to 23, wherein at least one of the first layer, the second layer, or the third layer further comprises at least one additive selected from the group consisting of an adhesion promoter, a pigment, a dye, a corrosion inhibitor, an antistatic agent, a plasticizer, a thickener, a thixotropic agent, a processing aide, a plurality of nanoparticles, a plurality of fibers, and combinations thereof.

25. The multilayer composition of any of claims 1 to 24, exhibiting a haze of 1.0% or less.

26. The multilayer composition of any of claims 1 to 25, wherein the latent UV crosslinker is present in the first layer.

27. The multilayer composition of any of claims 1 to 26, wherein the latent UV crosslinker is present in the second layer.

28. The multilayer composition of any of claims 1 to 27, wherein the first adhesive composition further comprises a polymer additive.

29. The multilayer composition of any of claims 1 to 28, wherein the second adhesive composition further comprises a polymer additive.

30. A method of making a multilayer composition, the method comprising: coating a first solution, a second solution, and a third solution, thereby forming a multilayer composition, the multilayer composition comprising: a first layer comprising a first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; a third layer comprising a second adhesive composition;a latent UV crosslinker present in at least one of the first layer or the second layer; and a UV absorber present in at least one of the second layer or the third layer; wherein the second layer is disposed between the first layer and the third layer.

31. The method of claim 30, wherein the coating of the first solution, the second solution, and the third solution is simultaneous.

32. The method of claim 30, wherein the coating of the first solution, the second solution, and the third solution is sequential.

33. The method of any of claims 30 to 32, further comprising exposing at least one of the first solution, the second solution, or the third solution to actinic radiation prior to the coating.

34. The method of any of claims 30 to 33, wherein the multilayer composition is according to any of claims 1 to 29.

35. A method of making a multilayer adhesive composition, comprising exposing the multilayer composition of any of claims 1 to 29 to UV radiation.

36. A multilayer adhesive composition comprising a first layer comprising a crosslinked first adhesive composition; a second layer comprising a (meth)acrylate composition and a polymer additive distributed in the (meth)acrylate composition; a third layer comprising a second adhesive composition; and a UV absorber present in at least one of the second layer or the third layer; wherein the second layer is disposed between the first layer and the third layer.

37. The multilayer adhesive composition of claim 36, wherein the second adhesive composition is crosslinked.

38. The multilayer adhesive composition of claim 36 or claim 37, exhibiting a haze of 1.0% or less.

39. The multilayer adhesive composition of any of claims 36 to 38, exhibiting a 180 Peel on Glass at 25 degrees Celsius of 3.0 Newtons per centimeter (N / cm) or greater.

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