Polymeric substrates coated with multilayer barrier films, their manufacture and use in electronic devices

Abstract

The present invention relates to a polymeric substrate coated with a multilayer barrier film, the multilayer barrier film having at least a radiation-cured intermediate layer on a polymeric substrate and one or more at least partially inorganic barrier layers on the intermediate layer, the intermediate layer being formed by applying and radiation-curing a radiation-curable intermediate layer coating material on the polymeric substrate, the radiation-curable intermediate layer coating material having a hydroxyl number in the range of 50 to 250 mg KOH / g. The present invention further relates to methods for making such a multilayer barrier film-coated polymeric substrate and methods of using the same.

Description

[Technical Field]

[0001] The present invention relates to a polymer substrate coated with a multilayer barrier film (MLBF), which comprises an intermediate layer between the polymer substrate and a further layer. The present invention further relates to a method for producing a substrate coated with the MLBF. Furthermore, the present invention relates to a method for using a substrate coated with the MLBF in photovoltaic applications. [Background technology]

[0002] Polymer films are widely used and useful in a wide range of industrial and consumer applications. Such films can be employed, for example, as clear or colored barrier films to protect various types of underlying substrates. Polymer films, particularly those made from semi-crystalline resins such as polyester materials, offer many desirable properties for barrier films. Among these are transparency, flexibility, impact resistance, scratch resistance, hardness, durability, toughness, flexibility, formability, lightweight, and reasonable cost.

[0003] In particular, such films find use in electronic devices, including optoelectronic devices, such as electroluminescent (EL) display devices (particularly organic light emitting diode, OLED, devices), electrophoretic displays (electronic paper), and flexible photovoltaic cells (CIGS, perovskite, and / or OPV).

[0004] Flexible polymer film substrates and the layers deposited thereon are typically transparent and must meet stringent specifications for optical clarity, flatness, and minimal birefringence. A total light transmittance (TLT) of at least 85% in the 400-1100 nm range and a haze of less than 2% are generally desirable. Surface smoothness and flatness are necessary to ensure the integrity of subsequently applied layers. Multilayer film stacks also desirably have good barrier properties, i.e., high resistance to gas, moisture, and solvent permeation.

[0005] Flexible polymer substrates and coating layers enable roll-to-roll manufacturing of electronic and optoelectronic devices, reducing costs.

[0006] However, polymer films often have disadvantages, such as poor chemical resistance, barrier properties, and dimensional stability compared to optical-quality glass or quartz. To minimize this problem, inorganic and organic barrier coatings have been developed, which are typically applied by a high-temperature sputtering process. US 6,198,217 discloses materials suitable as barrier layers. WO 2003 / 022575 A1 discloses flexible polymer films that include the deposition of a barrier layer on a polymer substrate and exhibit good high-temperature dimensional stability under high-temperature processing conditions experienced in the manufacture of backplanes and display devices.

[0007] However, some of the most desirable polymer films may be severely limited in their use if a submicron-sized, defect-free, transparent barrier layer needs to be deposited directly thereon.

[0008] WO 2022 / 233992 A1 describes a multilayer barrier film including an inorganic barrier layer deposited on a transparent polymer polyester film, and proposes the use of an optional UV-curable planarization layer between the polyester film and the inorganic barrier. Such a planarization layer is proposed in WO 2022 / 233992 A1, particularly for cases where a substrate film with high flatness is unavailable, for example, due to small scratches or dust-like particles adhering to its surface. Therefore, the main purpose of the planarization layer is to prevent damage, such as puncturing, to the multilayer barrier film. However, WO 2022 / 233992 A1 also mentions that the planarization layer may further serve to better maintain the polymer substrate film and MLBF together, especially when bending or heating, but does not provide any specific suggestions for achieving such a function. WO 2022 / 233992 A1 rather refers to the formulation of other UV-curable compositions used herein, which are however rather aimed at having good adhesion to topcoat layers, in particular topcoat layers containing fluoropolymers. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] US 6,198,217 [Patent Document 2] WO 2003 / 022575 A1 [Patent Document 3] WO 2022 / 233992 A1 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, there remains a need for an MLBF-coated substrate that includes an improved interlayer between the polymer substrate and the inorganic barrier layer, which interlayer has good adhesion to both the substrate and the inorganic barrier layer and functions as a planarizing layer. Furthermore, the dynamic mechanical properties of such MLBF-coated substrates should be excellent, and the interlayer coating material used to produce such an interlayer should have a suitable viscosity range. [Means for solving the problem]

[0011] The above object of the present invention is achieved by providing a polymer substrate (A) coated with a multilayer barrier film (MLBF), the multilayer barrier film comprising at least a radiation-cured intermediate layer (I) on a polymer substrate (A), and one or more at least partially inorganic barrier layers (B) on the intermediate layer (I) Including, The intermediate layer (I) is formed by applying a radiation-curable intermediate layer coating material (ICM) onto the polymer substrate and radiation curing, the radiation-curable intermediate layer coating material (ICM) having a hydroxyl number in the range of 50 to 250 mg KOH / g.

[0012] FIG. 1 shows a typical structure of an MLBF on a substrate (A) according to the present invention, which comprises, in that order, an intermediate layer (I), an at least partially inorganic barrier layer (B), and an optional topcoat layer (C).

[0013] Thus, in the MLBF on substrate (A) claimed according to the present invention, there is direct contact between substrate (A) and intermediate layer (I), and between intermediate layer (I) and the at least partially inorganic barrier layer (B), respectively.

[0014] The term "at least partially inorganic" in the context of an "at least partially inorganic barrier layer (B)" means that the inorganic barrier layer (B) itself can consist of one or more inorganic layers, i.e. layers that are completely composed of inorganic materials. In another embodiment, the "partially inorganic barrier layer (B)" consists of at least one inorganic layer and at least one organic layer, preferably arranged alternately; therefore, in such a case, the complete layer (B) consisting of inorganic and organic layers is understood as "partially inorganic". The term "radiation cured" with respect to the radiation cured intermediate layer (I) refers to the radiation curability of the crosslinkable monomers, oligomers and polymers used to prepare the radiation cured intermediate layer (I).

[0015] Hereinafter, a substrate coated with the claimed MLBF is also referred to as a "substrate coated with the multilayer barrier film of the present invention" or a "substrate coated with the MLBF of the present invention."

[0016] Yet another object of the present invention is to provide a method for producing a pharmaceutical composition comprising the steps of: a. providing a polymer substrate (A); b. applying a radiation-curable interlayer coating material (ICM) as defined above to the MLBF-coated substrate of the present invention and curing the radiation-curable interlayer coating material (ICM) to form a radiation-cured interlayer (I); c. depositing one or more inorganic layers on the substrate by one or more methods selected from chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), and sputtering to form one or more at least partially inorganic barrier layers (B); A method for producing a polymer substrate (A) coated with a multilayer barrier film, comprising:

[0017] Hereinafter, the method for producing a substrate coated with a multilayer barrier film will also be referred to as "a method for producing a substrate coated with a multilayer barrier film according to the present invention" or "a method for producing a substrate coated with an MLBF according to the present invention."

[0018] Yet another object of the present invention is a substrate coated with the MLBF of the present invention or a method for using a substrate coated with the MLBF of the present invention in an electronic device, including an optoelectronic device.

[0019] Hereinafter, a method for using the MLBF of the present invention or a substrate coated with the MLBF of the present invention in an electronic device including an optoelectronic device will also be referred to as a "method for use of the present invention."

[0020] Further preferred features and embodiments of the invention are disclosed in the dependent claims and the following detailed description. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 shows a typical structure of an MLBF on a substrate (A) according to the present invention. [Figure 2] FIG. 2 shows a possible “microarchitecture” of layer (B) when it consists of a layer stack (BiBo)n(Bi)t with n=2, t=1 and 0. [Figure 3] FIG. 3 shows the structure of an MLBF in another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Substrates coated with multi-layer barrier films In the following, various types of substrates that can be coated with the multilayer barrier film are disclosed, followed by a more detailed description of the formation of the intermediate layer (I) and the at least partially inorganic barrier layer (B).

[0023] Preferably, the polymer substrate (A) and all subsequent layers are transparent. The term "transparent," as used hereinafter with respect to layers and substrates, means that the layer and / or substrate is translucent, i.e., light-transmitting. The term "transparent," as used herein, can be quantified by determining the total luminous transmittance in accordance with ASTM D 1003:2013. Preferably, the total luminous transmittance thus determined for each layer of the MLBF, the MLBF itself, and the MLBF-coated substrates described hereinafter is in the range of 80% to 99%, more preferably in the range of 85% to 98%, and most preferably in the range of 90% to 97%.

[0024] Base material The substrate can be any polymeric substrate.

[0025] Suitable polymers include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalenedicarboxylic acid (PEN); polyimides; polyacrylates such as polymethyl methacrylate (PMMA); polyacrylamides; polycarbonates such as poly(bisphenol A carbonate); polyvinyl alcohol and its derivatives, such as polyvinyl acetate or polyvinyl butyral; polyvinyl chloride; polyolefins, including polycycloolefins, such as polyethylene (PE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE). Examples of polymers include high-density polyethylene (HDPE), polypropylene (PP), and polynorbornene; polysulfones, such as polysulfone (PSU), polyethersulfone (PES), and polyphenylenesulfone (PPSU); polyamides, such as polycaprolactam (PA6) or poly(hexamethylene adipamide) (nylon 66); cellulose derivatives, such as hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, methylhydroxypropyl cellulose, or nitrocellulose; polyurethanes; epoxy resins; melamine formaldehyde resins; and phenol formaldehyde resins. The term "polymer" includes copolymers made from two or more different monomers, such as poly(ethylene-co-norbornene) or poly(ethylene-co-vinyl acetate).

[0026] Of the aforementioned polymers, transparent polymers from the group consisting of polyesters, polyolefins, polyamides and polysulfones are preferred, with polyesters such as PET being most preferred.

[0027] Preferably, the polymer substrate should be heat stable to at least 140°C.

[0028] The substrate can be of any size and shape. Preferably, the substrate, most preferably the polymeric substrate, is in the form of a transparent polymeric substrate film. Preferred film thicknesses are in the range of 10 to 500 μm, more preferably 25 to 300 μm, and even more preferably 50 to 150 μm.

[0029] Intermediate layer (I) As stated above, "radiation cured" with respect to the radiation cured intermediate layer (I) means the radiation curability of the crosslinkable species selected from the monomers, oligomers and polymers used to prepare this layer.

[0030] Preferably, the radiation-curable monomers, oligomers and polymers contain at least one, preferably two or more, radiation-curable groups such as (meth)acrylic, vinyl and / or allyl groups, with (meth)acrylic groups being most preferred and more preferably being the only radiation-curable groups in the radiation-curable monomers, oligomers and polymers contained in the radiation-curable interlayer coating material (ICM) used to prepare the radiation-cured interlayer (I).

[0031] It is most preferred that the radiation-cured intermediate layer (I) is a (meth)acrylate layer, i.e., it is essential that at least a portion of the monomers, oligomers, and polymers before curing, i.e., before crosslinking, contain (meth)acrylic groups that react with each other to form the radiation-cured (meth)acrylate layer. The term "(meth)acrylate" refers to both "acrylate" and "methacrylate." The same applies to the use of the terms "(meth)acrylic" and "(meth)acrylic acid."

[0032] Thus, radiation curing is typically achieved by actinic radiation such as electron beam (EB) or UV radiation, with curing by UV radiation being particularly preferred.

[0033] The radiation-cured intermediate layer (I) is therefore preferably based on a UV-curable, solvent-free (meth)acrylic system, since the term "solvent-free" means free of non-reactive solvents, and reactive diluents are not excluded by this term.

[0034] The intermediate layer (I) provides good compatibility with many polymer films (A) and also at least partially with the inorganic layer (B). However, the polymer film (A) often does not have the best flatness due to, for example, small scratches or dust particles adhering to its surface. Therefore, it is preferable that the intermediate layer (I) also functions as a planarizing layer.

[0035] As a requirement of the present invention, the intermediate layer coating material (ICM) must have a hydroxyl number in the range of 50 to 250 mg KOH / g, preferably 55 to 250 mg KOH / g, and more preferably 60 to 230 mg KOH / g, as determined in detail in the experimental section of this specification. Therefore, the cured intermediate layer (I) will also contain hydroxyl groups, some of which will be present at the intermediate layer (I)-air interface. The inventors have found that the hydroxyl number has a positive effect on the adhesion of the subsequently deposited, at least partially inorganic, barrier layer (B). To introduce such hydroxyl functionality into the ICM and thus into the cured intermediate layer (I), the ICM must contain a hydroxy-functional radiation-curable component, such as a radiation-curable oligomeric (meth)acrylate-functional species and / or a radiation-curable (meth)acrylate-functional monomer, as described in more detail below.

[0036] Preferably, the intermediate layer coating material (ICM) used to prepare the intermediate layer (I) has a viscosity at 25°C, determined before curing, in the range of 80 to 250 mPas, more preferably 90 to 220 mPas, most preferably 100 to 200 mPas. Details of the viscosity measurement method are described in the experimental section of this specification.

[0037] Preferably, the intermediate layer coating material (ICM) used to prepare the intermediate layer (I) has a viscosity at 50°C determined before curing in the range of 20 to 80 mPas, more preferably 25 to 60 mPas, and most preferably 25 to 50 mPas. Details of the viscosity measurement method are described in the experimental section of this specification.

[0038] The cured intermediate layer (I) made from the intermediate layer coating material (ICM) should be flexible, but still have a glass transition temperature, determined as detailed in the experimental section of this specification, preferably in the range of 60 to 150°C, more preferably in the range of 70 to 145°C, and most preferably in the range of 80 to 145°C.

[0039] The storage modulus of the intermediate layer (I) at 20°C is determined as described in detail in the experimental section of this specification and is preferably at least 1000 MPa and preferably 3000 mPa or less, more preferably at least 1200 MPa and 2500 MPa or less, or even more preferably at least 1500 MPa and 2200 MPa or less.

[0040] The preferred components of the intermediate layer coating material (ICM) are as follows: The species used to form the intermediate layer coating material (ICM) and its intermediate layer (I) are preferably: i. one or more radiation-curable oligomeric (meth)acrylate functional species; ii. one or more radiation-curable (meth)acrylate-functional monomers; iii. optionally one or more adhesion promoters; iv. For UV curing, one or more photoinitiators; v. one or more compounds selected from UV absorbers and light stabilizers; and vi. optionally, one or more coating additives Includes.

[0041] Radiation-curable oligomeric (meth)acrylate functional species i. The one or more radiation-curable oligomeric (meth)acrylate functional species are preferably selected from the group consisting of polyester (meth)acrylates, epoxy (meth)acrylates, aliphatic and / or aromatic urethane (meth)acrylates, preferably aliphatic urethane (meth)acrylates, polyether (meth)acrylates and (meth)acrylated poly(meth)acrylates, of which urethane (meth)acrylates, especially aliphatic urethane acrylates and (meth)acrylated poly(meth)acrylates, are preferred.

[0042] Polyester (meth)acrylates typically have a lower viscosity than other oligomers, while epoxy (meth)acrylates are highly reactive, resulting in coatings that exhibit good hardness and chemical resistance.

[0043] The (meth)acrylated poly(meth)acrylate helps to provide good adhesion. Preferably, the (meth)acrylated poly(meth)acrylate has an acid value in the range of 0 to 10 mgKOH / g, more preferably 0 to 5 mgKOH / g, and most preferably 0 to 2 mgKOH / g, and / or a hydroxyl value in the range of 0 to 10 mgKOH / g, more preferably 0 to 5 mgKOH / g, and most preferably 0 to 2 mgKOH / g.

[0044] Aromatic urethane (meth)acrylates impart flexibility, elongation, toughness, good hardness, and chemical resistance to the resulting coatings, while multifunctional aromatic urethane (meth)acrylates exhibit improved reactivity. However, aliphatic urethane (meth)acrylates are preferred because they exhibit similarly good properties to aromatic urethane (meth)acrylates but are less prone to undesirable yellowing. Preferably, the aliphatic urethane (meth)acrylates have a (meth)acrylate functionality in the range of 2 to 4 and / or a hydroxyl number in the range of 1 to 20 mg KOH / g, more preferably 2 to 10 mg KOH / g, and even more preferably 2 to 8 mg KOH / g.

[0045] The aforementioned radiation-curable oligomeric (meth)acrylate functional species preferably contain functional groups selected from the group consisting of OH and COOH groups. Most preferably, urethane (meth)acrylates contain OH groups, while (meth)acrylated poly(meth)acrylates contain COOH and / or OH groups, preferably at least COOH groups.

[0046] The total amount of the one or more radiation-curable oligomeric (meth)acrylate-functional species i. is preferably in the range of 1% to 35% by weight, most preferably 3% to 30% by weight, and even more preferably 5% to 25% by weight, based on the combined weight of the radiation-curable oligomeric (meth)acrylate-functional species i. and the radiation-curable (meth)acrylate-functional monomer ii.

[0047] The total amount of the one or more radiation-curable oligomeric (meth)acrylate functional species i. is preferably in the range of 1% to 30% by weight, more preferably 3% to 25% by weight, and even more preferably 3% to 20% by weight, based on the interlayer coating material (ICM).

[0048] Radiation-curable (meth)acrylate-functional monomers ii. The one or more radiation-curable (meth)acrylate-functional monomers are known to those skilled in the art of radiation-curable compositions. Such radiation-curable (meth)acrylate-functional monomers have low viscosity. Such monomers are often used to dilute radiation-curable oligomeric (meth)acrylate-functional species and function as solvents, but are also referred to as radiation-curable reactive diluents because they remain in the cured coating after curing. Such monomers may optionally contain di- or tri-alkylene glycol groups, but are still considered monomers herein due to their distinct molecular weight.

[0049] The one or more (meth)acrylate functional monomers preferably include mono(meth)acrylate functional monomers, di(meth)acrylate functional monomers, and less preferably tri- and / or tetra(meth)acrylate functional monomers, with even higher functionalities not excluded but being even less preferred.

[0050] Of the one or more (meth)acrylate functional monomers, mono(meth)acrylate functional monomers and di(meth)acrylate functional monomers are most preferred.

[0051] To achieve the desired hydroxyl number of the interlayer coating material (ICM), it is typically insufficient for the radiation-curable oligomeric (meth)acrylate-functional species to contain only hydroxyl groups. Therefore, to achieve the required hydroxyl number of the ICM, it is usually necessary to use one or more (meth)acrylate-functional monomers having one or more additional hydroxyl groups.

[0052] The total amount of the one or more radiation-curable (meth)acrylate-functional monomers ii., preferably containing one or more hydroxyl groups, is preferably in the range of 18% to 95% by weight, most preferably 20% to 95% by weight, based on the total weight of the intermediate layer coating material (ICM), and is, of course, selected to meet the required hydroxyl number as defined herein above.

[0053] Preferred (meth)acrylate-functional monomers further having one or more hydroxyl groups are the mono(meth)acrylates and di(meth)acrylates of glycerol, trimethylolpropane, and trimethylolethane; and the mono(meth)acrylates, di(meth)acrylates, and tri(meth)acrylates of pentaerythritol, ditrimethylolpropane, and ditrimethylolethane. However, it is also possible to use α,ω-alkanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylates, such as 1,2-ethanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate, 1,3-propanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate, and 1,4-butanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate.

[0054] Among the above (meth)acrylate functional monomers further having one or more hydroxyl groups, di(meth)acrylate functional monomers further having one or two hydroxyl groups are even more preferred.

[0055] The most preferred di(meth)acrylate functional monomer having one additional hydroxyl group is glycerol di(meth)acrylate. The most preferred di(meth)acrylate functional monomer having two additional hydroxyl groups is 1,4-butanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate.

[0056] In addition to the (meth)acrylate functional monomer having one or more hydroxyl groups, other (meth)acrylate functional monomers are typically included in the intermediate layer coating material (ICM) used in the present invention.Such (meth)acrylate functional monomers preferably contain only hydrocarbon groups or ether oxygen-containing hydrocarbon groups in addition to (meth)acrylic groups.Examples of such (meth)acrylate functional monomers are listed below.

[0057] Examples of mono(meth)acrylate functional monomers include hydrocarbyl esters of (meth)acrylic acid, where the hydrocarbyl residue is aliphatic or aromatic, linear, branched, or cyclic, and preferably the hydrocarbyl group contains from 4 to 20, more preferably from 6 to 18, carbon atoms. Specific examples include alkyl (meth)acrylates such as cyclohexyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, tert-octyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, 4-n-butylcyclohexyl (meth)acrylate; bornyl (meth)acrylate; isobornyl (meth)acrylate; tricyclodecane methanol (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; and aryl (meth)acrylates such as 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, and 2,3,4,5-tetramethylphenyl (meth)acrylate. Further examples of mono(meth)acrylate functional monomers include ether oxygen-containing hydrocarbyl esters of (meth)acrylic acid, where the ether oxygen-containing hydrocarbyl residue can be aliphatic or aromatic and linear, branched, or cyclic, and preferably the ether oxygen-containing hydrocarbyl group contains 4 to 20, more preferably 6 to 18, carbon atoms. Specific examples include alkoxyalkyl (meth)acrylates such as butoxyethyl (meth)acrylate, butoxymethyl (meth)acrylate, and 3-methoxybutyl (meth)acrylate; aryloxyalkyl (meth)acrylates such as phenoxymethyl (meth)acrylate and phenoxyethyl (meth)acrylate; 2-ethylhexyl diglycol (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate, and 2-(2-butoxyethoxy)ethyl (meth)acrylate; and trimethylolpropane formal (meth)acrylate.

[0058] Of the aforementioned mono(meth)acrylate functional monomers, the cyclic hydrocarbon esters of (meth)acrylic acid and the cyclic ether oxygen-containing hydrocarbon esters of (meth)acrylic acid are most preferred, such as isobornyl (meth)acrylate, tricyclodecane ethanol (meth)acrylate, and trimethylolpropane formal (meth)acrylate.

[0059] Examples of di(meth)acrylate functional monomers are alkanediol di(meth)acrylates, where the alkanediol preferably contains 3 to 16 carbon atoms, more preferably 4 to 14. Specific examples include 1,3-propanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, and 1,14-tetradecanediol di(meth)acrylate. Further examples of di(meth)acrylate functional monomers include dialkylene glycol di(meth)acrylates, such as diethylene glycol di(meth)acrylate and dipropylene glycol di(meth)acrylate; trialkylene glycol (meth)acrylates, such as triethylene glycol di(meth)acrylate and tripropylene glycol di(meth)acrylate; and neopentyl glycol-propoxy di(meth)acrylate.

[0060] Less preferred are tri- and tetra(meth)acrylate functional monomers. The higher the functionality, the less preferred the monomer is in the present invention. Specific examples of tri(meth)acrylate functional monomers include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, or glycerol tri(meth)acrylate, and specific examples of tetra(meth)acrylate functional monomers include pentaerythritol tetra(meth)acrylate.

[0061] Preferably, the radiation curable composition of the present invention comprises only mono(meth)acrylic and di(meth)acrylic monomers from group ii. of radiation curable (meth)acrylate functional monomers.

[0062] The total amount of the one or more radiation-curable (meth)acrylate-functional monomers ii. is preferably in the range of 65% to 99% by weight, most preferably 70% to 97% by weight, and even more preferably 75% to 95% by weight, based on the combined weight of the radiation-curable oligomeric (meth)acrylate-functional species i. and the radiation-curable (meth)acrylate-functional monomers ii.

[0063] The total amount of the one or more radiation-curable (meth)acrylate-functional monomers ii. is preferably in the range of 65% to 95% by weight, more preferably 65% ​​to 92% by weight, and even more preferably 70% to 92% by weight, based on the total weight of the interlayer coating material (ICM).

[0064] Adhesion promoteriii. When an adhesion promoter is present, the one or more adhesion promoters are preferably selected from the group consisting of functionalized trialkoxysilanes and functionalized dialkoxyalkylsilanes, preferably functionalized trialkoxysilanes, such as functionalized trimethoxysilanes (wherein the functional group is preferably selected from thiol groups, (meth)acrylic groups, amino groups, and epoxy groups); and (meth)acrylated phosphate esters. Some of the aforementioned adhesion promoters iii. have (meth)acrylate groups and are monomers, but are not included in the amount of radiation-curable (meth)acrylate-functional monomer ii.

[0065] The total amount of the one or more adhesion promoters iii. is preferably in the range of 0% to 10% by weight, more preferably 1% to 8% by weight, and most preferably 2% to 7% by weight, based on the total weight of the radiation-curable interlayer coating material (ICM).

[0066] Photopolymerization initiator iv. In the case of UV curing, it is preferable to contain one or more α-cleavable photopolymerization initiators, such as, for example, one or more photopolymerization initiators selected from the group consisting of α-hydroxyketones (e.g., benzoin, acetophenone), α-alkoxyketones (e.g., benzointer, benzil ketal), α-aminoketones, and acylphosphine oxides.

[0067] The photopolymerization initiator is encompassed by the terms "surface-curing type" such as α-alkoxyketone and "bulk-curing type" such as acylphosphine oxide. When both are present, the mass ratio of the photopolymerization initiator between the surface-curing type and the bulk-curing type is preferably in the range of 1:4 to 1:1.

[0068] When included, the total amount of one or more photoinitiators iv. is preferably in the range of 0.5% to 6% by weight, most preferably 1% to 5% by weight, and even more preferably 2% to 4% by weight, based on the total weight of the radiation-curable interlayer coating material (ICM).

[0069] UV absorbers, light stabilizers v. The UV absorber is preferably selected from the group consisting of 2-(2'-hydroxyphenyl)benzotriazole, 2-hydroxybenzophenone, esters of substituted and unsubstituted benzoic acid, acrylates such as ethyl α-cyano-β,β-diphenylacrylate, 2-(2-hydroxyphenyl)-1,3,5-triazine and oxamide.

[0070] The total amount of the one or more UV absorbers v. is preferably in the range of 0% to 8% by weight, more preferably 1 to 6% by weight, and most preferably 2 to 5% by weight, based on the total weight of the radiation-curable interlayer coating material (ICM).

[0071] The light stabilizer v is preferably a hindered amine light stabilizer (HALS), including NOR-HALS. NOR-HALS is a subclass of HALS, also known as aminoxy radical hindered amine light stabilizers. HALS act as bases and are neutralized by acids, for example, but NOR-HALS are not strong bases and are not deactivated by hydrochloric acid.

[0072] The total amount of the one or more light stabilizers v. is preferably in the range of 0 to 5% by weight, more preferably 0.5 to 4% by weight, and most preferably 0.8 to 3% by weight, based on the total weight of the radiation-curable interlayer coating material (ICM).

[0073] Coating additivesvi. The radiation curable interlayer coating material (ICM) may contain typical coating additives such as leveling agents, antifoaming agents, and is preferably, but not necessarily, sensitive to radiation curing.

[0074] The amount of coating additive is preferably in the range of 0 to 5 wt %, more preferably 0 to 3 wt %, and most preferably 0 to 2 wt %, based on the total weight of the radiation curable interlayer coating material (ICM).

[0075] Particularly preferred embodiments of the interlayer coating material (ICM) The interlayer coating material (ICM) preferably comprises: i. one or more radiation-curable oligomeric (meth)acrylate-functional species selected from the group consisting of polyester (meth)acrylates, epoxy (meth)acrylates, aliphatic and / or aromatic urethane (meth)acrylates, preferably aliphatic urethane (meth)acrylates, polyether (meth)acrylates, and (meth)acrylated poly(meth)acrylates; ii. one or more radiation-curable (meth)acrylate-functional monomers selected from the group consisting of mono(meth)acrylate-functional monomers, di(meth)acrylate-functional monomers, and tri(meth)acrylate-functional monomers, wherein at least a portion of the (meth)acrylate-functional monomers have one or more hydroxyl groups; iii. optionally, one or more adhesion promoters selected from the group consisting of functionalized trialkoxysilanes and functionalized dialkoxyalkylsilanes functionalized with groups selected from thiol groups, (meth)acrylic groups, amino groups, and epoxy groups; and (meth)acrylated phosphate esters; iv. one or more photoinitiators; v. one or more compounds selected from UV absorbers and / or light stabilizers, preferably one or more compounds selected from the group consisting of hindered amine light stabilizers, including NOR-HALS; and vi. Optionally, one or more coating additives.

[0076] More preferably, the intermediate coating material (ICM) comprises: i. one or more radiation-curable oligomeric (meth)acrylate functional species selected from the group consisting of aliphatic and / or aromatic urethane (meth)acrylates, and (meth)acrylated poly(meth)acrylates; ii. one or more radiation-curable mono(meth)acrylate-functional monomers, and one or more di(meth)acrylate-functional, hydroxyl-group-containing monomers; iii. optionally, one or more adhesion promoters selected from the group consisting of (meth)acryltrialkoxysilanes, (meth)acryldialkoxyalkylsilanes; and (meth)acrylated phosphate esters; iv. one or more photoinitiators selected from the group consisting of α-cleavable photoinitiators such as α-hydroxyketones, α-alkoxyketones, α-aminoketones, and acylphosphine oxides; v. one or more compounds selected from the group consisting of 2-(2'-hydroxyphenyl)benzotriazole, 2-hydroxybenzophenone, esters of substituted and unsubstituted benzoic acid, acrylates such as ethyl α-cyano-β,β-diphenylacrylate, UV absorbers selected from the group consisting of 2-(2-hydroxyphenyl)-1,3,5-triazine and oxamide, and / or one or more light stabilizers selected from the group consisting of hindered amine light stabilizers including NOR-HALS; and vi. Optionally, one or more coating additives.

[0077] The most preferred interlayer coating materials (ICM) include: i. one or more radiation-curable oligomeric (meth)acrylate functional species selected from the group consisting of aliphatic urethane (meth)acrylates, and (meth)acrylated poly(meth)acrylates; ii. one or more radiation-curable mono(meth)acrylate-functional monomers, preferably selected from cyclic hydrocarbyl esters of (meth)acrylic acid and ether-oxygen-containing cyclic hydrocarbyl esters of (meth)acrylic acid; and one or more di(meth)acrylate-functional, hydroxyl-group-containing monomers; iii. optionally, one or more adhesion promoters selected from the group consisting of (meth)acryltrialkoxysilanes (meth)acryldialkoxyalkylsilanes; and (meth)acrylated phosphate esters; iv. one or more photoinitiators selected from the group consisting of α-cleavable photoinitiators such as α-hydroxyketones, α-alkoxyketones, α-aminoketones, and acylphosphine oxides; v. one or more compounds selected from the group consisting of 2-(2'-hydroxyphenyl)benzotriazole, 2-hydroxybenzophenone, esters of substituted and unsubstituted benzoic acid, acrylates such as ethyl α-cyano-β,β-diphenylacrylate, UV absorbers selected from the group consisting of 2-(2-hydroxyphenyl)-1,3,5-triazine and oxamide, and / or one or more light stabilizers selected from the group consisting of hindered amine light stabilizers including NOR-HALS; and vi. Optionally, one or more coating additives.

[0078] In any of the foregoing embodiments, but also generally, the (meth)acrylate-functional monomers further having one or more hydroxyl groups are the mono(meth)acrylates and di(meth)acrylates of glycerol, trimethylolpropane, and trimethylolethane; and the mono(meth)acrylates, di(meth)acylates, and tri(meth)acrylates of pentaerythritol, ditrimethylolpropane, and ditrimethylolethane. However, it is also possible to use α,ω-alkanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylates, such as 1,2-ethanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate, 1,3-propanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate, and 1,4-butanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate.

[0079] More preferred among the above-mentioned monomers are glycerol, di(meth)acrylates of trimethylolpropane and trimethylolethane, pentaerythritol, ditrimethylolpropane, ditrimethylolethane and 1,4-butanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate.

[0080] Most preferred are glycerol di(meth)acrylate and 1,4-butanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate, with glycerol di(meth)acrylate being even more preferred.

[0081] Preferred range of ingredients Preferably, the amounts of the above components i. to vi. in the intermediate layer coating material (ICM) are in the following ranges: i. 1 to 30% by mass, more preferably 3 to 25% by mass, and most preferably 3 to 20% by mass; ii. 65 to 95% by mass, more preferably 65 to 92% by mass, and most preferably 70 to 92% by mass; iii. 0 to 10% by mass, more preferably 1 to 8% by mass, most preferably 2 to 7% by mass, iv. 0.5 to 6% by mass, more preferably 1 to 5% by mass, most preferably 2 to 4% by mass; v. In the case of a UV absorber, 0 to 8% by weight, more preferably 1 to 6% by weight, most preferably 2 to 5% by weight, and In the case of a light stabilizer, 0 to 6 mass%, more preferably 0.5 to 4 mass%, most preferably 0.8 to 3 mass%, vi. 0 to 5% by mass, more preferably 0 to 3% by mass, most preferably 0 to 2% by mass.

[0082] The sum of all components contained in the intermediate layer coating material (ICM) is 100% by mass.

[0083] It is permissible to combine ranges of one or more ingredients with any range of other ingredients as long as the total of the ingredients does not exceed 100% by weight.

[0084] More preferably, the preferred ranges of i., ii., and iv. are combined, the more preferred ranges of i., ii., and iv. are combined, or the most preferred ranges of i., ii., and iv. are combined. Any of the aforementioned combined ranges can be independently combined with the preferred ranges, more preferred ranges, or most preferred ranges of components iii., v., and vi.

[0085] All of the most preferred ranges are combined, all of the more preferred ranges are combined, or all of the most preferred ranges are combined.

[0086] Thickness of the radiation-cured interlayer (I) formed from the radiation-curable interlayer coating material (ICM) The final thickness of the radiation-cured intermediate layer (I) is preferably in the range of 1 to 20 μm, more preferably 2 to 15 μm, and most preferably 4 to 10 μm. A layer thickness in this range facilitates crack-free and pinhole-free coating after deposition of the at least partially inorganic barrier layer, and still allows winding of the final film without damaging the at least partially inorganic barrier layer.

[0087] an at least partially inorganic barrier layer (B); The at least partially inorganic barrier layer (B) is preferably transparent and serves to provide a good moisture barrier to the MLBF. The water vapor transmission rate (WVTR) at 60°C and 90% relative humidity is preferably 5 x 10 -3 g / m 2 / day or less.

[0088] As defined above, the term "at least partially inorganic" in the context of an "at least partially inorganic barrier layer (B)" means that the inorganic barrier layer (B) itself consists of one or more inorganic layers, i.e., layers that are completely composed of inorganic materials, and is therefore an "inorganic barrier layer (B)". In another embodiment, the "partially inorganic barrier layer (B)" consists of at least one inorganic layer and at least one organic layer, preferably arranged in alternating order; therefore, a complete layer (B) consisting of inorganic and organic layers is in such a case understood as "partially inorganic".

[0089] When layer (B) consists of one or more inorganic layers, layer (B) is hereinafter referred to as (B i ) mwhere "i" represents "inorganic" and m represents the number of layers. Preferably, m is 1 to 2000, more preferably m=10 to 1000, and most preferably m=20 to 500.

[0090] When the layer (B) further comprises one or more organic layers in addition to the one or more inorganic layers, the layer (B) is hereinafter referred to as (B i B o ) n (B i ) t where "i" stands for "inorganic", "o" stands for "organic", and n stands for (B i B o ) and t represents the number of repeating layers, and t represents 1 or 0. The first layer of the barrier layer deposited on the intermediate layer (I) is always the inorganic layer B i However, the final layer in such a stack can be either an inorganic layer (t=1) or an organic layer (t=0). The presence of such an organic layer between inorganic layers provides additional flexibility to the barrier, especially when the MLBF thickness exceeds 50 nm.

[0091] FIG. 2 shows the layer (B) in the layer stack (B i B o ) n (B i ) t 1 shows a possible "microarchitecture" of layer (B) when it consists of:

[0092] The inorganic layer (B) is at least partially formed on the inorganic barrier layer (B i The essential presence of ) is responsible for the rollability and flexibility of the entire MLBF without the risk of compromising its water vapor transmission rate.

[0093] Inorganic layer (B i The deposition of the organic layer (B) can be achieved by several different techniques, such as, for example, chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD) and / or sputtering. oThe deposition of inorganic layers can be achieved, for example, by chemical vapor deposition (CVD), molecular layer deposition (MLD), organic (thermal or electron beam) deposition, wet coating deposition. Techniques such as PVD, CVD, sputtering for obtaining inorganic layers are known to those skilled in the art and are described, for example, in US 2013 / 0034689 A1 and EP 2 692 520 A1.

[0094] The inorganic materials used to form the one or more inorganic layers are selected from the group consisting of metal oxides, metal nitrides, metal oxynitrides, and combinations thereof.

[0095] The most preferred inorganic materials for forming the inorganic layer are metal oxides, particularly metal oxides of aluminum, titanium, silicon, zinc, zirconium, hafnium, indium, tin, indium-tin, tantalum, and calcium, of which aluminum, silicon, and titanium, or calcium with titanium and aluminum, are preferred oxide elements. In any of the embodiments described herein, it is particularly preferred to use metal oxides as the inorganic material for forming the inorganic layer(s).

[0096] It is also possible to use metal nitrides as inorganic materials. Among metal nitrides, the group of metal nitrides consisting of aluminum nitride, silicon nitride and boron nitride is preferred. The inorganic layer (B) on the intermediate layer (I) is i The formation of a metal nitride layer as a PET substrate is preferably achieved by PE (plasma-enhanced)-CVD, CVD, ALD, or sputtering. Suitable techniques are described, for example, in WO2011028119. A thin silicon nitride barrier layer produced by PE-CVD on a PET substrate was found to have a thickness of 5×10 -4 g / m 2 It has been shown in the literature (W. Manders et al., AIMCAL R2R Conference, Florida 2017) that the WVTR is 100 / day.

[0097] Furthermore, metal oxynitrides can be used as the inorganic material. Among metal oxynitrides, a group of metal oxynitrides consisting of aluminum oxynitride, silicon oxynitride, and boron oxynitride is preferred. The inorganic layer (B) on the intermediate layer (I) i The formation of a metal oxynitride layer as a metal oxide nitride layer is preferably achieved by PE (plasma-enhanced)-CVD, CVD, ALD, or sputtering. Suitable techniques are described, for example, in CN 1899815 B.

[0098] Inorganic layer (B i In (B), the above inorganic materials can be used in combination. i ) m In the stack of inorganic layers such as i ) can be independently selected from the inorganic materials described above, and (B i B o ) n (B i ) t and the values ​​of m, n and t are as described above in this specification. Preferably, the layer thickness of the one or more at least partially inorganic barrier layers (B) is in the range of 10 to 1000 nm in total, more preferably in the range of 20 to 500 nm, most preferably in the range of 30 to 200 nm.

[0099] Inorganic layer(s) (B i ), preferably a metal oxide layer (B i Among the aforementioned techniques for the deposition of (B) is preferred i ) m ALD when (B) is (B i B o ) n (B i ) t ALD in combination with MLD where:

[0100] Preferably, a transparent barrier layer (B iThe use of ALD techniques for the preparation of the metal oxide layers (B) is preferred because ALD allows for the stepwise formation of chemically bonded nanolaminate self-limiting layers with excellent thickness control, each of which is highly conformal, well-ordered, and dense, with defined thickness. Such methods, especially for the preparation of metal oxide layers (B), are particularly advantageous. i ) are disclosed, for example, in WO 2011 / 099858 A1, but are also part of combined ALD / MLD techniques, as disclosed, for example, in WO 2015 / 188990 A2 and WO 2015 / 188992 A1.

[0101] An even more preferred transparent barrier layer is (B i B o ) n (B i ) t where the layer (B i ) is obtained by ALD, and the layer (B o ) are prepared by MLD. By combining ALD and MLD techniques, it is possible to deposit alternating organic flexibiling layers at the molecular level (a few nanometers thick) that are deposited covalently and chemically bonded to inorganic materials, as disclosed, for example, in WO 2015 / 188990 A2 and WO 2015 / 188992 A1.

[0102] Layer (B o The organic molecules used in the MLD technique to obtain the inorganic layer (B) can be, for example, thiols, disulfides, sulfides, selenols, amines, carboxylates, phosphates or phosphonates, or derivatives thereof, as described in WO 2015 / 030297 A1, WO 2015 / 188990 A2 and WO 2015 / 188992 A1. i ) has a special functional group that can chemically bond to the

[0103] Layer (B oThe most preferred organic molecules for fabricating mercaptobenzoic acid (MERB) belong to the family of aromatic thiols, such as mercaptobenzoic acid, mercaptophenol, aminomercaptophenol, etc. The purpose of this organic molecular layer is to impart the flexibility and bendability required for roll-to-roll processing (also known as web processing, reel-to-reel processing, or R2R, the process of creating electronic devices on rolls of flexible plastic).

[0104] Some details regarding the preparation of the at least partially inorganic barrier layer(s) (B) are provided in the following section describing the method of preparing the MLBF-coated substrates of the present invention.

[0105] Radiation-cured (meth)acrylate layer (C) Like the other layers and the polymer substrate, the optional radiation-cured (meth)acrylate layer (C) is preferably a transparent layer. Most preferably, this layer functions as the topcoat layer (C), i.e., the outermost layer of the substrate coated with the MLBF of the present invention. Therefore, the radiation-cured (meth)acrylate layer (C) must not only at least partially adhere to the inorganic layer (B), but also meet the requirements for a topcoat layer, such as scratch resistance and weather resistance, and in particular, this layer must provide excellent heat resistance.

[0106] The term "radiation-cured" is used in the same manner as above for the intermediate layer (I).

[0107] The radiation-cured (meth)acrylate layer(s) (C), like the intermediate layer (I), are preferably based on a UV-curable, solvent-free (meth)acrylic system, the term "solvent-free" meaning free from non-reactive solvents, since reactive diluents are not excluded by this term.

[0108] Preferably, the coating material used to produce the radiation-cured (meth)acrylate layer (C) has a viscosity at 25°C, determined by capillary viscometer or rotational rheometer, before curing, of less than 500 mPas, more preferably less than 300 mPas.

[0109] The final thickness of the radiation-cured (meth)acrylate layer (C) is preferably in the range of 1 to 100 μm, more preferably 1 to 50 μm, and most preferably 5 to 30 μm. The coating materials applied to form the radiation-cured (meth)acrylate layer(s) (C) can be applied by the same standard wet coating methods as can be used for the interlayer coating material (ICM).

[0110] Similar to the intermediate layer coating material (ICM), the coating material (CCM) used to prepare the radiation-cured (meth)acrylate layer (C) preferably comprises the following components: i. one or more radiation-curable oligomeric (meth)acrylate functional species; ii. one or more radiation-curable (meth)acrylate-functional monomers; iii. optionally one or more adhesion promoters; iv. For UV curing, one or more photoinitiators; v. one or more compounds selected from UV absorbers, light stabilizers, and antioxidants; and vi. optionally, one or more coating additives Includes.

[0111] Components i.-vi. are typically the same as the intermediate layer coating material (I), but there are some preferred variations, as shown below.

[0112] Typically, the one or more radiation-curable oligomeric (meth)acrylate functional species i. used in the coating material (CCM) have a viscosity at 25°C of greater than 70 mPas, determined as described in the experimental part of the present invention.

[0113] The total amount of the one or more radiation-curable oligomeric (meth)acrylate functional species i. is preferably in the range of 5% to 30% by weight, most preferably 5% to 20% by weight, and even more preferably 5% to 15% by weight, based on the total weight of the radiation-curable coating material (CCM).

[0114] The one or more radiation-curable (meth)acrylate-functional monomers ii. are preferably the same as those described above for the intermediate layer coating material (I), except that less or no hydroxy-functional (meth)acrylate-functional monomers ii. are used in the coating material (CCM) that forms the radiation-cured (meth)acrylate layer (C). Accordingly, the hydroxyl number of the coating material (CCM) is preferably 1 to 100 mg KOH / g, more preferably 2 to 60 mg KOH / g, and most preferably 5 to 30 mg KOH / g.

[0115] Such radiation-curable (meth)acrylate-functional monomers preferably have low viscosity, preferably viscosities of 1 to 50 mPas, more preferably 2 to 40 mPas, or 2 to 30 mPas at 25°C. These monomers are also referred to as radiation-curable reactive diluents because they are used to dilute the radiation-curable oligomeric (meth)acrylate-functional species. Although such monomers may optionally contain dialkylene glycol or trialkylene glycol groups, they are considered monomers herein due to their well-defined molecular weight and viscosity of 50 mPas or less at 25°C.

[0116] The total amount of the one or more radiation-curable (meth)acrylate-functional monomers ii. is preferably in the range of 10% to 90% by weight, most preferably 15% to 85% by weight, and even more preferably 20% to 80% by weight, based on the total weight of the radiation-curable coating material (CCM).

[0117] Adhesion promoter iii., when present, is defined as the one or more adhesion promoters as in the interlayer coating material (ICM).

[0118] The total amount of the one or more adhesion promoters iii. is preferably in the range of 0.5% to 10% by weight, most preferably 1% to 8% by weight, and even more preferably 1.5% to 7% by weight, based on the total weight of the radiation-curable coating material (CCM).

[0119] For the preferred UV cure, one or more photoinitiators are used, which are defined in the same way as for the interlayer coating material (ICM).

[0120] When included, the total amount of one or more photoinitiators iv. is preferably in the range of 0.5% to 6% by weight, most preferably 2% to 5% by weight, and even more preferably 3% to 4% by weight, based on the total weight of the radiation-curable coating composition.

[0121] The UV absorbers and light stabilizers are defined in the same way as for the interlayer coating materials (ICM).

[0122] The total amount of one or more UV absorbers v. is preferably in the range of 1 to 5% by weight, more preferably 1.5 to 3.5% by weight, based on the total weight of the radiation-curable coating material (CCM). The total amount of one or more light stabilizers v. is preferably in the range of 0.2 to 4% by weight, more preferably 0.5 to 3% by weight, and most preferably 0.8 to 2% by weight, based on the total weight of the radiation-curable coating material (CCM).

[0123] Antioxidant v. is preferably tert-butyl hindered phenol and serves to improve long-term weather resistance and heat resistance, properties particularly relevant to the topcoat layer.

[0124] The total amount of the one or more antioxidants v. is preferably in the range of 0.1% to 2% by weight, more preferably 0.2 to 1% by weight, based on the total weight of the radiation curable coating material (CCM).

[0125] The coating material (CCM) may contain typical coating additives such as leveling agents, antifoaming agents, etc., which are preferably, but not necessarily, reactive in radiation curing. The amount of coating additives is preferably in the range of 0-5 wt %, more preferably 0-3 wt %, and most preferably 0-2 wt %, based on the total weight of the radiation-curable interlayer coating material (ICM).

[0126] Examples of such coating materials (CCM) are described in examples C1 and C2 of WO 2022 / 233992 A1.

[0127] Method for producing a substrate coated with a multilayer barrier film The present invention comprises at least the following steps: a. providing a polymer substrate (A); b. applying an intermediate layer coating material (ICM) as defined above and curing the intermediate layer coating material (ICM) to form a cured intermediate layer (I); c. depositing one or more inorganic layers on the substrate by one or more methods selected from chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), and sputtering to form one or more at least partially inorganic barrier layers (B); d. optionally applying one or more radiation-curable (meth)acrylic coating materials (CCM) onto the one or more at least partially inorganic barrier layers (B) to form one or more radiation-curable (meth)acrylate layers and curing said layers to form one or more radiation-cured (meth)acrylate layers (C); e. optionally repeating steps c. and d.; f. optionally applying and curing a further coating material to form a further coating layer (D); The present invention provides a method for producing a polymeric substrate coated with a multilayer barrier film, comprising:

[0128] Process a. The substrate used in the above method is a polymer substrate, and more preferably is a transparent polymer substrate selected from those mentioned above.Substrate, particularly polymer substrate, can typically be surface-treated to enhance the adhesion between the support and the layer provided thereon.Examples of such surface treatment include, but are not limited to, corona discharge treatment, flame treatment, UV treatment, low-pressure plasma treatment, and atmospheric pressure plasma treatment.

[0129] Process b. In step b., an interlayer coating material (ICM) as defined above is applied.

[0130] These components and preferred embodiments, as well as the preferred content of the components in the interlayer coating material (ICM), are described in detail above.

[0131] Since the intermediate layer coating material (ICM) should be radiation-curable to form the intermediate layer (I), which is preferably transparent, this material should preferably be substantially free of light-absorbing pigments and fillers. The same applies to any coating material (CCM) that forms any radiation-cured (meth)acrylate layer (C).

[0132] The interlayer coating material (ICM) can be applied by any suitable wet coating method. Suitable coating methods include, for example, spin coating, blade coating, knife coating, kiss roll coating, cast coating, slot orifice coating, calendar coating, die coating, dipping, brushing, bar casting, roller coating, flow coating, wire coating, spray coating, dip coating, whirler coating, cascade coating, curtain coating, air knife coating, gap coating, rotary screen, reverse roll coating, (reverse) gravure coating, metering rod (Meyer bar) coating, slot die (extrusion) coating, hot melt coating, roller coating, and flexographic coating. Suitable printing methods include silk screen printing, relief printing such as flexographic printing, inkjet printing, intaglio printing such as direct gravure printing or offset gravure printing, lithographic printing such as offset printing, or stencil printing such as screen printing.

[0133] For preferred UV curing, the curing wavelength range, intensity, and energy of the UV light are selected depending on the photosensitivity of the interlayer coating material (ICM). Typically, the wavelengths are in the UV-A, UV-B, and / or UV-C ranges. Preferably, the radiation includes light with a wavelength of less than 400 nm, more preferably less than 380 nm. Particularly preferred is a radiation of at least 600 mJ / cm. 2 , more preferably 800 mJ / cm 2 The radiation source is a UV mercury lamp with a UV-Vis intensity of 10 ...

[0134] Process c. The inorganic layer is applied to the substrate by one or more methods selected from chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), and sputtering to form one or more preferably transparent, at least partially inorganic barrier layers (B).

[0135] The aforementioned methods are known to those skilled in the art. CVD methods for producing such layers are described, for example, in DE 4035951 C1 or CA 2562914 A1 and references therein; PVD methods for producing such layers are described, for example, in EP 0645470 A1 or US 5900271 A and references therein; and sputtering methods for producing such layers are described, for example, in US 2004 / 0005482 A1. Furthermore, reference is made to the above paragraphs describing inorganic materials, i.e., metal oxides, metal nitrides and metal oxynitrides, and to the literature therein describing suitable application methods.

[0136] However, when such layers are only inorganic layers, preferably metal oxide layers, it is most preferred to produce the preferably transparent barrier layer or layers using an ALD method, which is described in detail, for example, in WO 2011 / 099858 A1.

[0137] If one or more inorganic layers are applied, then between two or more inorganic layers applied, for example, by ALD, an organic layer comprising organic molecules can be applied, for example, by molecular layer deposition techniques.

[0138] Such a layer (B o The organic molecules used in the MLD technique to obtain the inorganic layer (B i ), preferably a metal oxide layer (B i ), such as a thiol, disulfide, sulfide, selenol, amine, carboxylate, phosphate or phosphonate, or a derivative thereof.

[0139] Layer (B o The most preferred organic molecules for preparing ) belong to the family of aromatic thiols, such as mercaptobenzoic acid, mercaptophenol, aminomercaptophenol, etc.

[0140] Such a partially inorganic barrier layer (B) is formed by removing the first inorganic layer (B) in step c. i ) followed by the deposition of an organic layer (B o ) is deposited on an inorganic layer (B i ) and the deposition of both layers results in a layer thickness in the range of 10-1000 nm, with the final layer being an inorganic layer (B i ) or organic layer (B o ), resulting in the formation of a partially inorganic barrier layer (B).

[0141] The application of such layers by MLD is described, for example, in WO 2015 / 030297 A1, WO 2015 / 188990 A2 and WO 2015 / 188992 A1, which are incorporated herein by reference.

[0142] Optional process d. Step d. can be carried out in the same manner as described for step b., but utilizing a radiation curable (meth)acrylic coating material (CCM).

[0143] Any "Step e." Steps c. and d. can be repeated one or more times to enhance the barrier function of the MLBF coated substrate.

[0144] Optional process f. The radiation-cured (meth)acrylate layer (C) is preferably the outermost coating layer, i.e., the topcoat layer, but the present invention does not exclude the application of one or more additional layers, although this is not preferred. Such coating layers may be cured by thermal curing, i.e., a mechanism that does not involve radiation but involves a binder having reactive functional groups and a separate crosslinker having functional groups reactive to the binder's functional groups. Such layer (D) may be the thermally cured layer (D) described in WO 2022 / 233992 A1.

[0145] Use of multi-layer barrier films and substrates coated with MLBF The substrate coated with this MLBF can be used as a protective sheet for electronic devices, including optoelectronic devices, for example, photovoltaic applications.This protective sheet can preferably be used as a front protective sheet (front sheet) or a rear protective sheet (back sheet) in applications such as solar cell modules, due to its light weight, flexibility and advantageous cost.Other possible applications include portable lighting devices, pre-packaging of electronics, including optoelectronics, and displays, such as OLED screens. [Example]

[0146] The present invention will now be illustrated by the following examples, in which all parts are by weight and percentages for components of compositions are by weight unless otherwise specified.

[0147] Test Procedure Interlayer Coating Materials (ICM) Testing Hydroxyl number (OH number) The hydroxyl number was determined by acetylating the free hydroxyl groups with acetic anhydride and titrating the excess acid using a Mettler Toledo Titrator Compact V20.

[0148] viscosity Viscosity was measured at 25°C or 50°C after 10 minutes of stirring at 100 rpm using a Brookfield CAP2000+ viscometer (spindle: conical disc code 1014 01).

[0149] Multilayer (barrier) film testing The multilayer (barrier) films were placed in sealed amber glass bottles and stored at a temperature of 23±2°C under uncontrolled air for at least 24 hours.

[0150] Tape cross-cut adhesion The cross-cut adhesion of the tapes was measured according to ASTM D3359-17 (6 blades, 2 mm apart; before (0 h) and after (168 h) climatic aging (temperature 85° C., relative humidity 85%); tape: Tesakrepp® 4331).

[0151] Dynamic Mechanical Analysis (DMA) DMA was measured using a Waters TA Instrument Discovery DMA 850 (frequency: 1 Hz, single; heating: equilibrate at 10°C; isothermal 5 min at 10°C; heat ramp: 5°C / min; method: multi-frequency strain).

[0152] The following parameters were determined: (a) Storage modulus at 20°C; (b) Glass transition temperature.

[0153] Coating layer thickness The layer thicknesses were measured for the dried or cured layers (P), (B), (C) and (D) using a non-destructive dry film measurement with a Coating Thickness Gauge, such as a Byko-Test 4200 (available from BYK Instruments).

[0154] Water Vapour Transmission Rate (WVTR) Test Water vapor transmission rate (WVTR) was evaluated optically by measuring the degradation of a layer of calcium metal deposited on a glass substrate, which reacts with moisture / water to form transparent, non-conductive calcium hydroxide and hydrogen over time. A multilayer barrier film (intermediate layer (I) + partially inorganic barrier layer (B)) supported by a polymer film (A) functions as what is called a "barrier film" in the cell, as shown in Figure 3 of the following scientific paper: Organic Electronics, 2014, 15, pp. 3746-3755. WVTR tests were performed at 60°C (90% relative humidity).

[0155] The WVTR test method and apparatus are described in detail in US2006 / 0147346A1 and Organic Electronic, 2014, 15, pp. 3746-3755.

[0156] Figure 3 from the latter scientific paper shows a schematic diagram of a calcium test cell and an illustration of the residual permeation pathways (black arrows) into the cell: a thin calcium film (the "sensor") is encapsulated by two barrier films (substrates, typically glass) and an adhesive perimeter seal. The sensor measures the combined permeability of all these barriers, plus the ingress of water vapor via interfacial permeation. The cavity is filled with nitrogen.

[0157] Example Polymer film / substrate (A) A polyester optical film (PET; polyethylene terephthalate; film thickness 125 μm; SKYROL® V7610 polyester film commercially available from Curbell Plastics) was used as the polymer substrate.

[0158] Interlayer Coating Material (ICM) Example 1 To a 200 ml dark brown four-neck round-bottom flask equipped with a magnetic stirrer, thermocouple, and condenser, 67.1 ml of glycerol dimethacrylate (328.66 mmol; 75 g), 13.74 ml of 1,4-butanediylbis[oxy(2-hydroxy-3,1-propanediyl)]diacrylate (46.19 mmol; 16 g), and 5 g of an aliphatic polyurethane acrylate resin, Laromer® UA9033 ((meth)acrylic group-functionalized urethane (meth)acrylate oligomer; Mw: ca. 1230 g / mol, OH number: ca. 6 mg KOH / g), were added sequentially under nitrogen atmosphere at room temperature with continuous stirring. To this mixture was added 1.0 ml of Tinuvin® 292 (1.32 mmol, 1 g) followed by 3 g of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (7.17 mmol).

[0159] The resulting mixture was left stirring under nitrogen overnight, filtered through a 1 μm plastic filter, and then coated onto a 125 μm PET film (SKYROL® V7610 polyester film) under nitrogen with a metal bar coater blade at 20 mm / min, followed by curing with a Hg-UV lamp. The final coating thickness is shown in Table 2.

[0160] The properties of the intermediate layer coating material (ICM) and the cured intermediate layer (I) are shown in Tables 1 and 2.

[0161] Examples 2 to 8 The intermediate layer coating materials (ICM) of Examples 2 to 8 and the intermediate layers (I) produced therewith were prepared in the same manner as in Example 1. The relevant amounts and data for Examples 2 to 8 are shown in Tables 1 and 2. Examples 7 and 8 relate to intermediate layer coating materials (CM) with hydroxyl values ​​(OH values) outside the range of 50 to 250 mg KOH / g, with hydroxyl values ​​(OH values) of 31 and 254 mg KOH / g, respectively.

[0162] Preparation of a partially inorganic barrier layer (B) The ALD deposition process of the polymer film (A) coated with the intermediate layer (I) was performed in a roll-to-roll line equipped with a 600 mm diameter cylindrical reactor (effective length 611 mm) divided into 20 segments (each segment approximately 94 mm long). Each segment contained a dosing section, an exhaust section, and an inert gas curtain section to separate the gases between the different segments to prevent contamination. The deposition and film functionalization process used a mixture of three gases: trimethylaluminum (TMA), distilled water (HO), and an organic precursor (4-mercaptophenol). Each precursor was dosed from a different segment within the cylinder. The pressure for dosing the different gases was approximately 300 mbar, and the temperature ranged from 110 to 120 °C.

[0163] For deposition, the polymer film (A) coated with the cured intermediate layer (I) was moved around the reactor at a speed of 1-2 m / min while the cylinder rotated at a surface speed opposite to the web speed. There was no direct contact between the substrate and the reactor.

[0164] When the polymer film (A) coated with the intermediate layer (I) was in the segment reaction volume, a monolayer of the precursor was deposited. By adjusting the web and / or drum speed containing the segment / precursor combination, AlO x A heterogeneous, partially inorganic barrier layer structure composed of an organic precursor was deposited on the film substrate.

[0165] The partially inorganic barrier layers thus prepared had a total thickness in the range of 40-50 nm, which was adjusted to provide optimal WVTR barrier properties and prevent cracking during film handling.

[0166] result As shown in Table 2, in Examples 1 to 6, all within the range of 50 to 250 mgKOH / g, the adhesion after tape cross-cut adhesion testing for both the substrate and interlayer assembly (A / I) and the substrate, interlayer, barrier layer, and topcoat layer assembly (A / I / B / C) was excellent at "hour 0." Even after 168 hours of weathering, three of the six examples were excellent and the other three were very good. This is particularly good because the cured interlayer is not actually directly exposed to weathering; only subsequent layers, especially the outermost layers, are exposed to weathering.

[0167] The storage modulus is in the most favorable range in all examples, and the glass transition temperature is high enough to resist undesirable softening in the typical temperature range of practice.

[0168] Furthermore, the WVTR remains in the desirable range. In Example 7, with a hydroxyl number below 50 mg KOH / g, the adhesion after the tape crosscut adhesion test of the assembly A / I / B / C is already unacceptable at "0 hours".

[0169] Example 8, with a hydroxyl number greater than 250 mg KOH / g, exhibits unacceptable adhesion after tape cross-cut adhesion testing of assembly A / I / B / C after 168 hours of weather aging. Storage modulus and glass transition temperature cannot be measured because the layers are too brittle.

[0170] Furthermore, the WVTR values ​​of Comparative Examples 7 and 8 are both greater than the desired range.

[0171] [Table 1]

[0172] [Table 2]

Claims

1. A polymer substrate (A) coated with a multilayer barrier film, the multilayer barrier film comprising at least a radiation-cured intermediate layer (I) on a polymer substrate (A), and one or more at least partially inorganic barrier layers (B) on said intermediate layer (I); Including, the intermediate layer (I) is formed by applying a radiation-curable intermediate layer coating material (ICM) onto the polymer substrate and then radiation-curing it; A polymer substrate (A) coated with a multilayer barrier film, wherein the radiation-curable interlayer coating material (ICM) has a hydroxyl number in the range of 50 to 250 mg KOH / g.

2. 2. The polymer substrate (A) coated with a multilayer barrier film according to claim 1, wherein the polymer substrate is selected from the group consisting of polyesters, polyimides, polyacrylates, polyacrylamides, polycarbonates, polyvinyl alcohols, polyvinyl chlorides; polyolefins, polysulfones, polyamides, cellulose derivatives, polyurethanes, epoxy resins, melamine formaldehyde resins, and phenol formaldehyde resins.

3. The radiation curable interlayer coating material (ICM) i. one or more radiation-curable oligomeric (meth)acrylate functional species; ii. one or more radiation-curable (meth)acrylate-functional monomers; iii. optionally one or more adhesion promoters; iv. for UV curing, one or more photoinitiators; v. one or more compounds selected from UV absorbers and light stabilizers; and vi. Optionally, one or more coating additives A polymer substrate (A) coated with the multilayer barrier film according to claim 1 or 2, comprising:

4. The intermediate layer coating material (ICM) i. one or more radiation-curable oligomeric (meth)acrylate functional species selected from the group consisting of polyester (meth)acrylates, epoxy (meth)acrylates, aliphatic and / or aromatic urethane (meth)acrylates, preferably aliphatic urethane (meth)acrylates, polyether (meth)acrylates, and (meth)acrylated poly(meth)acrylates; ii. one or more radiation-curable (meth)acrylate-functional monomers selected from the group consisting of mono(meth)acrylate-functional monomers, di(meth)acrylate-functional monomers, and tri(meth)acrylate-functional monomers, wherein at least a portion of the (meth)acrylate-functional monomers have one or more hydroxyl groups; iii. one or more optional adhesion promoters selected from the group consisting of functionalized trialkoxysilanes and functionalized dialkoxyalkylsilanes functionalized with a group selected from a thiol group, a (meth)acrylic group, an amino group, and an epoxy group; and (meth)acrylated phosphate esters; iv. one or more photoinitiators; v. one or more light stabilizers selected from the group consisting of hindered amine light stabilizers, including NOR-HALS; and vi. Optionally, one or more coating additives A polymer substrate (A) coated with the multilayer barrier film according to claim 1 or 2, comprising:

5. i. the one or more radiation-curable oligomeric (meth)acrylate functional species is selected from the group consisting of aliphatic and / or aromatic urethane (meth)acrylates, and (meth)acrylated poly(meth)acrylates; ii. one or more radiation-curable di(meth)acrylate functional monomers contain one or more hydroxyl groups, preferably one hydroxyl group; iii. the one or more optional adhesion promoters are selected from the group consisting of (meth)acryltrialkoxysilanes, (meth)acryldialkoxyalkylsilanes; and (meth)acrylated phosphate esters; iv. the one or more photoinitiators are selected from the group consisting of α-cleavable photoinitiators such as α-hydroxyketones, α-alkoxyketones, α-aminoketones, and acylphosphine oxides; v. the one or more compounds are selected from UV absorbers selected from the group consisting of 2-(2'-hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones, esters of substituted and unsubstituted benzoic acid, acrylates such as ethyl α-cyano-β,β-diphenylacrylate, 2-(2-hydroxyphenyl)-1,3,5-triazines, and oxamides; and one or more light stabilizers selected from the group consisting of hindered amine light stabilizers including NOR-HALS; A polymer substrate (A) coated with the multilayer barrier film according to claim 4.

6. ii. one or more radiation-curable mono(meth)acrylate-functional monomers include cyclic hydrocarbyl esters of (meth)acrylic acid and ether oxygen-containing cyclic hydrocarbyl esters of (meth)acrylic acid; and one or more di(meth)acrylate-functional, hydroxyl group-containing monomers; v. the one or more light stabilizers are selected from the group consisting of hindered amine light stabilizers, including NOR-HALS; A polymer substrate (A) coated with the multilayer barrier film according to claim 4.

7. ii. The polymer substrate (A) coated with the multilayer barrier film of claim 4, wherein the one or more radiation-curable mono(meth)acrylate functional monomers comprise at least one of: mono(meth)acrylates and di(meth)acrylates of glycerol, trimethylolpropane, and trimethylolethane; and mono(meth)acrylates, di(meth)acylates, and tri(meth)acrylates of pentaerythritol, ditrimethylolpropane, and ditrimethylolethane; and α,ω-alkanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate.

8. ii. The multilayer barrier film-coated polymer substrate (A) of claim 3, wherein the one or more radiation-curable mono(meth)acrylate functional monomers comprise at least one of glycerol di(meth)acrylate and 1,4-butanediylbis[oxy(2-hydroxy-3,1-propanediyl)]di(meth)acrylate.

9. Components i. to vi. of claim 3 are present in the following ranges: i. 1 to 30% by mass, ii. 65-95% by mass, iii. 0 to 10% by mass, iv. 0.5 to 6% by mass, v. 0 to 8% by weight of a UV absorber, and 0 to 6% by weight of a light stabilizer; vi. 0-5% by mass A polymer substrate (A) coated with the multilayer barrier film of claim 3, comprising:

10. said at least partially inorganic barrier layer (B) (1) An inorganic layer (B) formed by atomic layer deposition and made of one or more inorganic materials selected from the group consisting of metal oxides, metal nitrides, metal oxynitrides, and combinations thereof. ｉ ) or (2) A partially inorganic barrier layer (B) is formed in the layer stack (B ｉ B ｏ ) ｎ (B ｉ ) ｔ where B ｉ is an inorganic layer made of one or more inorganic materials selected from the group consisting of metal oxides, metal nitrides, metal oxynitrides, and combinations thereof; and B ｏ is an organic layer formed by molecular layer deposition, n=1 to 100 and t=0 or 1, and n B ｉ a first of the layers is formed directly on the radiation-cured intermediate layer (I); A polymer substrate (A) coated with the multilayer barrier film according to claim 1 or 2.

11. 3. A polymer substrate (A) coated with a multilayer barrier film according to claim 1 or 2, further comprising one or more radiation-cured (meth)acrylate layers (C) on said at least partially inorganic barrier layer (B).

12. The polymer substrate (A) has a thickness in the range of 10 to 500 μm; the radiation-cured intermediate layer (I) has a thickness in the range of 1 to 20 μm; said at least partially inorganic barrier layer (B) having a thickness in the range of 10 to 1000 nm; The radiation-cured (meth)acrylate layer (C) as defined in claim 11 has a thickness in the range of 1 to 100 μm; and 2. The multilayer barrier film-coated polymer substrate (A) of claim 1, wherein the at least partially inorganic barrier layers (B) and the radiation-cured (meth)acrylate layers (C) form an alternating layer stack of at least partially inorganic barrier layers (B) and radiation-cured (meth)acrylate layers (C), and a first at least partially inorganic barrier layer (B) is in direct contact with the radiation-cured intermediate layer (I).

13. a. providing a polymer substrate (A); b. applying a radiation-curable interlayer coating material (ICM) according to claim 3 and curing said radiation-curable interlayer coating material (ICM) to form a radiation-cured interlayer (I); c. depositing one or more inorganic layers (B) on the substrate by one or more methods selected from chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), and sputtering; ｉ ) to form one or more at least partially inorganic barrier layers (B); A method for producing a polymer substrate (A) coated with the multilayer barrier film of claim 1, comprising:

14. Step c. is followed by a further step of: d. applying one or more radiation-curable (meth)acrylic coating materials (CCM) onto the one or more at least partially inorganic barrier layers (B) to form one or more radiation-curable (meth)acrylate layers and curing said layers to form one or more radiation-cured (meth)acrylate layers (C); e. Optionally repeating steps c. and d.; and f. Optionally, applying and curing a further coating material to form a further coating layer (D). A method for producing a polymer substrate (A) coated with the multilayer barrier film of claim 13, comprising:

15. In step c., the first inorganic layer (B ｉ ) is deposited, followed by the deposition of an organic layer (B ｏ ) by molecular layer deposition (MLD) to form an inorganic layer (B ｉ ) and the deposition of both layers is repeated until a layer thickness in the range of 10-1000 nm is obtained, the last layer being an inorganic layer (B ｉ ) or organic layer (B ｏ 14. The method for producing a polymer substrate (A) coated with a multilayer barrier film according to claim 13, wherein the polymer substrate (A) is a polymer having a hydroxyl group and a hydroxyl group, and the hydroxyl group is a hydroxyl group.

16. 10. Use of a substrate coated with the multilayer barrier film of claim 1 or 2 in an electronic device, including an optoelectronic device.

17. 16. Use of a substrate coated with a multilayer barrier film obtainable by the method of claim 14 or 15 in an electronic device, including an optoelectronic device.

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