JP6101362B2 - Multilayer film having an adhesive layer - Google Patents

Description

  The present disclosure generally relates to multilayer release films having an adhesive layer and methods for making such membranes.

  Multilayer films are increasingly used in the industry. For example, the film can be used as a protective coupling, mask, label, temporary security device, or any combination thereof. Transparent films are used as protective covers in display devices such as cell phones, portable game machines or even television displays. The film is also used as a protective coating on the part to reduce scratches and protect the color.

  Many such films are adhered to the surface using an adhesive. In particular, these films can contain an adhesive. However, achieving the desired viscosity in an adhesive coated on a multilayer film is a time consuming process and may require high temperatures.

  Inappropriate curing can result in poor adhesion of the multilayer film, or can lead to undesirable excessive adhesion, particularly in removable films. In many cases, a catalyst is added to the adhesive formulation to control curing. However, adding excess catalyst to the adhesive formulation can result in a significant reduction in pot life and unacceptably high viscosity.

  Thus, an improved multilayer film having an adhesive is desirable.

FIG. 1 includes an illustration of an exemplary multilayer film. FIG. 2 includes an illustration of an exemplary multilayer film. FIG. 3 includes an illustration of an exemplary multilayer film. FIG. 4 includes an illustration of an exemplary multilayer film. FIG. 5 includes an illustration of an exemplary method for forming a multilayer film.

  In certain embodiments, the multilayer film includes a substrate film, an adhesive layer that covers the substrate film, and a release layer or coating that contacts the adhesive layer. The release layer or coating includes a release material and an agent having activity on the components of the pressure-sensitive adhesive layer. The base material may include a polymer film, and may include an antistatic layer provided either between the polymer film and the pressure-sensitive adhesive layer or on the surface of the polymer film opposite to the pressure-sensitive adhesive layer. . In another example, a liner film can be applied over the release coating to facilitate removal of the release coating from the adhesive at the end of use. In certain instances, the multilayer film may be dispensed from a roll.

  In another exemplary embodiment, a method of forming a multilayer film comprising dispensing a substrate film, coating the substrate film with an adhesive composition, and applying a release coating to the adhesive composition. Coating. The release coating includes a release material and an agent that is active on the components of the adhesive composition. Optionally, a liner film may be applied over the release coating. Alternatively, the release coating may be applied to the side of the substrate film opposite the adhesive layer so that the release coating contacts the adhesive composition when the multilayer film is wound on a roll. In a further example, the substrate film can include an antistatic layer. Alternatively, the antistatic layer can be coated and cured on the major surface of the polymer film.

  FIG. 1 includes an illustration of an exemplary multilayer film 100. For example, the multilayer film 100 includes a base film 102, an adhesive layer 104, and a release coating 108. The release coating 108 is in contact with the pressure-sensitive adhesive layer 104. The pressure-sensitive adhesive layer 104 may be in direct contact with the main surface 110 of the base film 102, or an intervening layer may be present between the base film 102 and the pressure-sensitive adhesive layer 104. As illustrated, the second main surface 112 of the base film 102 may form an outer layer of the multilayer film 100.

  In the example, the substrate film 102 includes one or more polymer material layers. For example, the polymer material may be a thermoplastic polymer material. In another example, the polymer layer may be a thermosetting material. In certain instances, the polymer layer is an extruded layer. The extruded layer can include additional coatings. In examples, the polymer material may be a polyolefin, acetate polymer, acrylic polymer, polyaryl ether ketone, polyester, polycarbonate, polyvinyl chloride, polyether, polyamide, polyimide, thermoplastic elastomer, liquid crystal polymer, fluoropolymer, or any of these Combinations are listed.

  Exemplary polyolefins include polyolefin homopolymers such as polyethylene, polypropylene, polybutene, polypentene, or polymethylpentene; polyolefin copolymers such as ethylene-propylene copolymer, ethylene-butene copolymer, or ethylene-octene copolymer; or blends thereof Or a combination is mentioned. Exemplary polyethylenes include high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), very low density polyethylene, or any combination thereof. Exemplary polyamides include nylon 6, nylon 6,6, nylon 11, nylon 12, or any combination thereof. Specific vinyl acetate includes ethylene vinyl acetate (EVA). Exemplary polyaryletherketone can include polyetherketone, polyetheretherketone, polyetheretherketoneketone, or any combination thereof. In a particular example, the polyaryletherketone can include polyetheretherketone (PEEK).

  Exemplary fluoropolymers include fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), perfluoroalkoxy (PFA), tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride (THV). ) Terpolymer, polychlorotrifluoroethylene (PCTFE), ethylene tetrafluoroethylene copolymer (ETFE), ethylene chlorotrifluoroethylene copolymer (ECTFE), terpolymer of ethylene, hexafluoropropylene, and tetrafluoroethylene, or these Any combination is mentioned.

  The acrylic polymer can include polyacrylate, polymethyl methacrylate, polymethacrylate, or any combination, for example, an impact grade or impact modified acrylic. The impact modified acrylic polymer generally comprises a copolymer of a monomer comprising an acrylic monomer and an effective amount of a suitable comonomer or graft site to produce the desired modulus and impact resistance. Acrylate rubber, polyacrylate rubber, polyacryl elastomer or may be referred to as “ACM”, a mixture of polyacrylate and polymethacrylate, polyacrylate and ethylene methacrylate copolymer (“EMAC”) (eg, Chevron Chemicals EMAC 2260), Alternatively, an acrylic elastomer that is a composition based on polyacrylate and ethylene butyl acrylate ("EBAC") may be used. Alternatively, the thermoplastic impact modified acrylic polymer is a transparent glassy acrylic polymer, such as a plastic copolymer of ethylene and a carboxylic acid compound selected from acrylic acid, methacrylic acid and mixtures thereof, and an elastomer. It may be a blend with the ingredients.

  Exemplary thermoplastic elastomers can include blends of polyolefins and elastomeric hard rubbers. For example, examples of the thermoplastic elastomer include polyolefin and an elastomer dispersed in the polyolefin. Exemplary elastomers can include diene elastomers. The diene elastomer is a crosslinkable copolymer comprising a diene monomer, such as ethylene propylene diene monomer (EPDM), ABS, or any combination thereof. Further exemplary elastomers may include elastomeric blends of olefins commonly known as thermoplastic olefins (TPO).

  In a further example, the polymer is a polyester, such as polyethylene terephthalate. In another example, the polyester is a liquid crystal polymer. Exemplary liquid crystal polymers include aromatic polyester polymers such as the trade names XYDAR® (Amoco), VECTRA® (Hoechst Celanese), SUMIKOSUPER ™ (Sumitomo Chemical), EKONOL ™ (Saint). -Gobain), DuPont HX (TM) or DuPont ZENITE (TM) (EI DuPont de Nemours), RODRUN (TM) (Unitika), GRANLAR (TM) (Grandmont), or any of these The combination of is mentioned. Examples of liquid crystal polymers include thermotropic (melt processable) liquid crystal polymers where the crystallinity of the constrained microlayer may be particularly advantageous.

  Returning to FIG. 1, the substrate film 102 has a thickness in the range of 0.5 mil to 10 mil, for example, in the range of 0.5 mil to 5.0 mil, in the range of 1 mil to 5.0 mil, or even in the range of 1 mil to 3 mil. Can have.

  The pressure-sensitive adhesive layer 104 may be formed from a curable pressure-sensitive adhesive composition. An adhesive is an adhesive whose degree of bonding is affected by the amount of pressure used to apply the adhesive to the surface. For example, the adhesive composition can include natural rubber, styrenic block copolymer, acrylate, polyurethane, silicone, polydiorganosiloxane polyurea copolymer, or any combination thereof. Exemplary styrenic block copolymers include styrene butadiene copolymer (SBR), styrene / isoprene / styrene block copolymer (SIS), acrylonitrile / styrene block copolymer, or any combination thereof.

  Acrylic polymers can be derived from monomers such as alkyl (meth) acrylates, alkyl acrylates, or alkyl methacrylates. Examples of alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) ) Acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (Meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, urethane Decyl (meth) acrylate, dodecyl (meth) acrylate or any combination thereof. In particular, the acrylic polymer may be polymethyl (meth) acrylate.

  In another example, the acrylic polymer may be a copolymer derived from at least one acrylate monomer and at least one polymerizable comonomer. Exemplary polymerizable comonomers include acrylonitrile, acrylamide, methacrylamide, vinyl ester, vinyl ether, vinyl amide, vinyl ketone, styrene, halogen-containing monomers, ionic monomers, acid-containing monomers, base-containing monomers, reactive silicon-containing groups and polymerizability. Monomers having both unsaturated groups, olefins, or any combination thereof. In further examples, the acrylic polymer backbone is a polyether backbone, such as poly (ethylene glycol) (PEG), poly (propylene glycol) (PPG), and poly (tetramethylene glycol) (PTMG), or any combination thereof It may be grafted by a macromer having

  In another example, the pressure-sensitive adhesive layer 104 includes polyurethane. For example, a polyurethane adhesive can be formed by the reaction of an isocyanate and a polyol. The isocyanate component can include methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), or any combination thereof. In the examples, the isocyanate can include methylene diphenyl diisocyanate (MDI) or toluene diisocyanate (TDI). In particular, the isocyanate includes methylene diphenyl diisocyanate (MDI) or a derivative thereof.

  In examples, the polyol can be a polyether polyol, a polyester polyol, a modified or grafted derivative thereof, or any combination thereof. Suitable polyether polyols are obtained by polyinsertion by alkylene oxide double metal cyanide catalysis, in the presence of alkali hydroxide or alkali alcoholate as catalyst, preferably 2 to 4 reactive hydrogen atoms. Produced by the anionic polymerization of alkylene oxides by addition of at least one initiator molecule containing in bound form or by cationic polymerization of alkylene oxides in the presence of a Lewis acid, for example antimony pentachloride or boron fluoride etherate. obtain. Suitable alkylene oxides can contain 2 to 4 carbon atoms in the alkylene radical. Examples include tetrahydrofuran, 1,2-propylene oxide, 1,2- or 2,3-butylene oxide; ethylene oxide, 1,2-propylene oxide, or any combination thereof. The alkylene oxides can be used individually, sequentially or as a mixture. Examples of initiator molecules include water or dihydric or trihydric alcohols such as ethylene glycol, 1,2-propanediol and 1,3-propanediol, diethylene glycol, dipropylene glycol, ethane-1,4-diol, Glycerol, trimethylolpropane, or any combination thereof.

  The curable adhesive composition can include a crosslinking agent, a catalyst, a thickening resin, or any combination thereof.

  Exemplary crosslinkers include polyfunctional ethylenically unsaturated monomers. Such monomers include, for example, divinyl aromatics, divinyl ethers, multifunctional maleimides, multifunctional acrylates and methacrylates, or any combination thereof. An exemplary divinyl aromatic includes divinylbenzene. As examples of polyfunctional (meth) acrylates, mention may be made of tri (meth) acrylates or di (meth) acrylates which are compounds containing 3 or 2 (meth) acrylate groups. Exemplary tri (meth) acrylates include trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, pentaerythritol Triacrylates or any combination thereof may be mentioned. Exemplary di (meth) acrylates include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,4-butanediol di (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, alkoxylated 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, cyclohexanedimethanol di (meth) acrylate, alkoxyl Cyclohexanedimethanol diacrylate, ethoxylated bisphenol A di (meth) acrylate, neopentyl glycol diacrylate, polyethylene glycol di ( Data) acrylate, polypropylene glycol di (meth) acrylate, urethane di (meth) acrylates or any combination thereof.

  As another exemplary cross-linking agent, copolymers of alkyl methacrylates such as methyl methacrylate and monomers that impart reactive amino, epoxy, hydroxy and / or carboxyl groups, and styrene and epoxidized terminal groups Blocks, tapered or random copolymers of terminal vinyl groups with butadiene or isoprene containing vinyl groups or any combination thereof.

  Further exemplary crosslinking agents include isocyanate-based crosslinking agents such as aliphatic polyisocyanates, cycloaliphatic polyisocyanates, aromatic polyisocyanates, aromatic aliphatic polyisocyanates, and dimers and trimers thereof and reaction products thereof. Product or polymer. Examples of isocyanate crosslinking agents include tolylene diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, diphenylmethane diisocyanate, dimer of diphenylmethane diisocyanate, reaction product of trimethylolpropane and tolylene diisocyanate, trimethylolpropane (propnae) and A reaction product with hexamethylene diisocyanate, a polyether polyisocyanate, a polyester polyisocyanate, or any combination thereof. Another crosslinker includes Si-H terminal molecules.

  The cross-linking agent is used in an effective amount sufficient to cause cross-linking of the pressure-sensitive adhesive to impart the appropriate bond strength and to produce the desired final adhesive properties on the target substrate. The crosslinking agent may be used in an amount of 0.01 to 20 parts, for example 0.1 to 10 parts, based on the total weight of the monomers. For example, the amount of the isocyanate compound used is about 0.01 to 20 parts by weight, for example 0.05 to 15 parts by weight, based on 100 parts by weight of the polymer.

  The catalyst can include an organometallic catalyst, an amine catalyst, or a combination thereof. Examples of organometallic catalysts include dibutyltin dilaurate, lithium carboxylate, tetrabutyl titanate, bismuth carboxylate, or any combination thereof. In another example, the catalyst can include platinum-vinylsiloxane, a platinum-olefin complex, such as Pt-divinyltetramethyldisiloxane, or any combination thereof.

  Exemplary titanium catalysts include organofunctional titanates, siloxy titanates, or any combination thereof. Exemplary organofunctional titanates include 1,3-propanedioxytitanium bis (ethylacetoacetate); 1,3-propanedioxytitanium bis (acetylacetonate); diisopropoxytitanium bis (acetylacetonate); -Di-isopropoxy-bis (ethyl acetate) titanium; titanium naphthenate; tetrapropyl titanate; tetrabutyl titanate; tetraethylhexyl titanate; tetraphenyl titanate; tetraoctadecyl titanate; tetrabutoxy titanium; tetraisopropoxy titanium; Titanates; β-dicarbonyltitanium compounds such as bis (acetylacetonyl) diisopropyl titanate; or any combination thereof. Siloxy titanates include tetrakis (trimethylsiloxy) titanium, bis (trimethylsiloxy) bis (isopropoxy) titanium, or any combination thereof.

  Exemplary tin compounds include: dibutyltin dilaurate; dibutyltin diacetate; dibutyltin dimethoxide; carbomethoxyphenyltin tris-uberate; tin octoate; isobutyltin tricelloate; dimethyltin dibutyrate; dimethyltin dineodecanoate; Tin tartrate; dibutyltin dibenzoate; tin oleate; tin naphthenate; butyltin tri-2-ethylhexoate; tin butyrate; or any combination thereof. In another example, the catalyst can include a zirconium compound, such as zirconium octoate.

  As amine catalysts, tertiary amines such as tributylamine, N-methylmorpholine, N-ethylmorpholine, N, N, N ′, N′-tetramethylethylenediamine, pentamethyldiethylenetriamine and higher homologues, 1,4- Diazabicyclo- [2,2,2] -octane, N-methyl-N′-dimethylaminoethylpiperazine, bis (dimethylaminoalkyl) piperazine, N, N-dimethylbenzylamine, N, N-dimethylcyclohexylamine, N, N-diethylbenzylamine, bis (N, N-diethylaminoethyl) adipate, N, N, N ′, N′-tetramethyl-1,3-butanediamine, N, N-dimethyl-β-phenylethylamine, bis ( Dimethylaminopropyl) urea, bis (dimethylaminopropyl) a Amide groups (eg, formamide groups) such as 1,2,2-dimethylimidazole, 2-methylimidazole, monocyclic and bicyclic amidines, bis (dialkylamino) alkyl ethers such as bis (dimethylaminoethyl) ether And tertiary amines having any of these, or any combination thereof. Other examples of catalyst components include secondary amines such as dimethylamine, or aldehydes such as formaldehyde, or ketones such as acetone, methyl ethyl ketone or cyclohexanone, or phenols such as Mannich including phenol, nonylphenol or bisphenol. A base. Catalysts in the form of tertiary amines having hydrogen atoms that are active towards isocyanate groups include triethanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylethanolamine, and Mention may be made of alkylene oxides, for example reaction products with propylene oxide or ethylene oxide, or secondary-tertiary amines, or any combination thereof. A silamine having a carbon-silicon bond, such as 2,2,4-trimethyl-2-silamorpholine, 1,3-diethylaminomethyltetramethyldisiloxane, or any combination thereof can also be used as a catalyst.

  In a further example, the amine catalyst is pentamethyldiethylenetriamine, dimethylaminopropylamine, N, N′dimethylpiperazine and dimorpholinoethyl ether, N, N′dimethylaminoethyl N-methylpiperazine, JEFFCAT® DM-70 ( N, N ′ dimethylpiperazine and dimorpholinoethyl ether), imidazoles, triazines, or any combination thereof.

  As a catalyst for free radical polymerization, free radical initiators such as azo type initiators such as 2,2'-azobis (isobutyronitrile) may be mentioned. Other initiators include dialkyl peroxides such as di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5- Di (t-butylperoxy) -3-hexyne, dicumyl peroxide, t-butylcumyl peroxide and α, 60′-bis (t-butylperoxy) isopropylbenzene, diacyl peroxide, such as benzoyl peroxide P-chlorobenzoyl peroxide, m-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, peroxyesters such as t-butyl perbenzoate, peroxydicarbonates such as diisopropylperoxy Dicarbonate and di-2-ethylhexyl Peroxydicarbonate, peroxyketal, such as 1,1-di (t-butylperoxy) cyclohexane and 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, or these Peroxide initiators including any combination are mentioned. Peroxyesters include t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, or any combination thereof. A particularly useful peroxyester as a secondary initiator for reducing residual monomer is t-amyl peroxypivalate.

  A thickener may be combined with the adhesive composition. The thickening agent may be substantially compatible with the base polymer. “Substantially compatible” means that when the thickener and polymer are combined, the resulting combination is substantially transparent in the form of a dry film with respect to normal vision, as opposed to opaque. means. Exemplary thickeners include rosin and rosin derivatives, including naturally occurring rosin materials in pine tree oleoresin, and derivatives thereof, such as rosin esters, modified rosins, such as fractionation, hydrogenation, dehydration A primed and polymerized rosin, a modified rosin ester, or any combination thereof may be mentioned.

  Other exemplary thickening agents include terpene resins that are hydrocarbons of formula C10H16 present in most plant essential oils and oleoresin, and α-pinene, β-pinene, dipentene, limonene, myrcene, bornylene, Phenol-modified terpene resins such as camphene, or any combination thereof. Exemplary thickeners include, for example, aliphatic hydrocarbon resins based on C9, C5, dicyclopentadiene, coumarone, indene, styrene, substituted styrene and styrene derivatives, aromatic hydrocarbon resins, or the like Arbitrary combinations can also be mentioned. Another exemplary thickening agent includes liquid paraffin, such as alkyl naphthene.

  The amount of thickener may be in the range of 0% to 60%, for example in the range of 5% to 60%, by total weight of the one or more thickeners.

  Adhesive compositions include diluents, relaxation agents, plasticizers, excipients, antioxidants, UV stabilizers, anti-irritants, opacifiers, fillers such as clays and silicas, pigments and mixtures thereof, antiseptics Mention may also be made of agents, as well as other components or additives.

  Returning to FIG. 1, the adhesive layer 104 is in the range of 0.1 mil to 10 mil, for example in the range of 0.25 mil to 5.0 mil, in the range of 0.25 mil to 2 mil, or even in the range of 0.25 mil to 1 mil. Can have a thickness.

  The release layer or coating 108 can include a composition that is immiscible with the adhesive composition. The release layer or coating 108 may be in direct contact with the adhesive layer 104. In particular, at least a portion of the release layer or coating 108 can be easily separated from the adhesive layer 104. For example, the release layer or coating 108 can include a release material, such as a silicone-based, fluorine-based, long-chain alkyl-based, fatty acid amide-based, silica powder material, or any combination thereof. Exemplary release materials are silicone-based release materials such as addition curable and condensation curable silicones. In this type of release material, a platinum (Pt) or rhodium (Rh) catalyst is generally used as a curing catalyst for the release agent.

  Alternatively, the release material may be formed from grease or oil that maintains some viscosity. For example, the release material can include silicone grease, fluorosilicone oil, phenyl silicone oil, paraffin wax, or any combination thereof.

  In certain instances, the release coating 108 includes an agent, such as a catalyst, that is active to facilitate curing of the curable adhesive composition. For example, the agent can facilitate crosslinking of at least one component of the pressure-sensitive adhesive composition. In particular, the release coating 108 comprises an agent, such as the above catalyst, in the range of 0.01% to 5.0% by weight, for example in the range of 0.1% to 2.5% by weight, 0.5%. % To 2.0% by weight, or even 0.5% to 1.5% by weight.

  The release coating 108 may have a thickness in the range of 0.025 mil to 10 mil, for example in the range of 0.025 mil to 5.0 mil, in the range of 0.25 mil to 2 mil, or even in the range of 0.25 mil to 1 mil. it can.

  In the particular embodiment shown in FIG. 2, the multilayer film 200 includes a substrate film 202 that includes more than one layer. For example, the polymeric substrate 202 can include a polymer film 204 and an antistatic layer 206. The pressure-sensitive adhesive layer 208 may be coated on the polymer film 204, and the release coating 210 may be coated on the pressure-sensitive adhesive layer 208. Optionally, the liner film 212 may be applied over the release coating 210. Alternatively, the release coating 210 may be coated on the liner film 212 and the combined layers (210, 212) are in contact with the adhesive layer 208 on the release coating surface (210).

  The polymer layer 204 may be formed from the polymers described above in connection with the substrate film 102. Antistatic coating 206 can comprise a dissipative polymer such as polyether block amide, ionomer, polyimide, polyamide, or any combination thereof.

  In another example, the antistatic coating 206 can include a filled polymer. Examples of the polymer include acrylate, polyolefin, polyurethane, polyester, polyether, polyamide, polyimide, polyaryletherketone, or any combination thereof. Exemplary fillers can include conductive fillers such as metal particles, conductive ceramic particles, carbon black, conductive fibers, carbon nanotubes, graphene, or any combination thereof. In a further example, the antistatic coating can include a deposited metal layer, such as a sputtering or vapor deposition layer.

  In particular, the antistatic coating 206 can have a surface resistivity in the range of 105 to 1012 Ω / sq. For example, the surface resistivity of the antistatic coating may range from 108 to 1012 Ω / sq, such as from 109 to 1012 Ω / sq.

  The pressure-sensitive adhesive layer 208 and the release coating 210 may be formed from the above materials. In particular, the release coating 210 includes an agent, such as a catalyst, that activates at least one component of the adhesive layer 208.

  Optionally, the liner film 212 may be applied over the release coating 210. In the example, liner film 212 includes a film or paper that adheres to the release coating. Exemplary polymer films may include polyolefin, acetate, acrylic, polyaryletherketone, polyester, polyether, polyamide, polyimide, thermoplastic elastomer, styrene polymer, liquid crystal polymer, fluoropolymer, or any combination thereof. it can. In the example, the release liner 212 includes a cellulose acetate film. In another example, the liner film 212 includes a polyolefin film. In a further example, the liner film 212 includes a polyester film. In an example, the liner film 212 may be treated to improve adhesion to the release coating, for example, by corona discharge, plasma discharge, ion treatment, and the like. The liner film 212 can have a thickness in the range of 0.5 mil to 5 mil, such as in the range of 0.5 mil to 3 mil, or even in the range of 1 mil to 3 mil.

  In another exemplary embodiment shown in FIG. 3, the multilayer film 300 can include a substrate film 302. In the example, the substrate film 302 includes a polymer film 304 and an antistatic layer 306. In the exemplary multilayer film 300, the adhesive 308 may be provided on the first major surface 312 of the substrate film 302, while the release coating 310 is provided on the opposite major surface 314 of the substrate film 302. Good. When the multilayer film is wound on a roll for later dispensing, the release coating 310 is placed in contact with the adhesive layer 308 to facilitate curing or crosslinking of the adhesive layer 308.

  The multilayer polymeric substrate is shown as having an antistatic layer 306 on the major surface of the substrate film 302 that is in contact with the release coating 310, but the antistatic coating and other layers have been repositioned. Good. For example, the multilayer film shown in FIG. 4 includes a polymeric substrate 402 with a polymer layer 404 in contact with a release coating 410 and an antistatic layer 406 in contact with an adhesive layer 408. When the film 400 is rolled, a release coating 410 comprising an active agent in at least one component of the adhesive composition in the adhesive layer 408 comes into contact with the adhesive layer 408, resulting in an adhesive composition in the layer 408. To cure and crosslink.

  FIG. 5 includes an illustration of an exemplary process for forming a multilayer film. For example, process 500 includes a roll of substrate film 502 into which the substrate film is dispensed. The substrate film 502 can include one or more polymer film layers. In some cases, the substrate film includes an antistatic layer. Alternatively, the antistatic layer may be dispensed and cured as a coating at the coating station 504. The antistatic coating (not shown) may be designed to cure at room temperature by some other curing mechanism in response to heat and in response to actinic radiation. For example, the antistatic coating may be processed in an oven 514.

  The pressure-sensitive adhesive composition may be coated on the substrate film 502 at the coating station 506. The adhesive composition can be selected from the compositions disclosed above. Optionally, the adhesive composition may be baked or dried in an oven 516, for example. Alternatively, the adhesive composition may be treated with actinic radiation.

  A release coating may also be applied over the adhesive composition at the coating station 508. The release coating includes an active agent in at least one component of the adhesive composition dispensed at 506. In the example, the release coating is not heat treated after deposition. Alternatively, the release coating can be cured by actinic radiation or heat treatment.

  Alternatively, the release coating may be applied to the major surface of the substrate film 502 opposite to the adhesive composition applied at 506. When the multilayer film is wound on roll 510, the release coating applied at 508 contacts the opposite side of the multilayer film with the adhesive coating.

  While the coating station (504, 506 or 508) is shown as a distribution on the substrate film 502, other coating techniques can be used to apply the coating layer. For example, roll coating, gravure coating, knife coating, dip coating, spray coating, slot die coating, or variations thereof.

  Optionally, the system 500 includes a roll 512 for dispensing a liner film over the release coating dispensed at 508. The multilayer film is wound on a roll 510 that is stored for later use. Variations on this process are possible. For example, as disclosed above, the release coating station 508 may dispense the release coating from the roll 512 onto the liner film, and the lamination station will bond this substructure to the substrate film / release coating substructure. Can do.

  Once formed, the multilayer film has a peel strength of 1000 g / inch or less, such as a range of 2 g / inch to 500 g / inch, a range of 3 g / inch to 200 g / inch, or a peel strength of 4 g / inch to 100 g / inch. Can have strength. Peel strength is measured at an angle of 180 ° to the stainless steel plate and a peel rate of 12 inches / minute.

  Furthermore, the cure performance may be measured as a cure index defined as the ratio of the peel strength at 18 hours divided by the peel strength at 7 days. In particular, the multilayer film can have a cure index of 2 or less, such as 1.5 or less, or even 1.2 or less.

  An adhesive mixture is prepared comprising an acrylic adhesive, an isocyanate crosslinker and a dibutyltin dilaurate catalyst. The mixture is cast into a 2 mil thick polyethylene terephthalate (PET) sheet and dried in an oven at 135 ° C. for 1.5 minutes. The final thickness of the adhesive is 0.55 mil to 0.6 mil. One set of sheets is covered with a tin-containing silicone-release coating liner; the other set is covered with a tin catalyst-free silicone-release coating liner. Samples are aged at room temperature for 18 hours, 3 days or 7 days. After aging for a specified time, the release coating liner is removed and the PSA is laminated to the PET substrate with a 4.5 lb lab roller. After 20 minutes, PSA peel adhesion is tested and recorded. The peel test parameters are 180 ° and 12 inches / minute.

  As shown in Table 1 below, after 18 hours, the peel strength of the sample with the tin-containing silicone-release coating liner reached full cure, but the peel strength of the sample with the tin-free silicone-release coating liner Is still expensive. After aging for 3 days, PSA with tin-free silicone-release coating liner approaches full cure.

  In particular, it has been discovered that the curing time can be reduced by adding a catalyst to the release layer. Curing time can be accelerated by adding a catalyst to the pressure sensitive adhesive composition, but increasing the amount of catalyst in the pressure sensitive adhesive composition results in low pot life and high viscosity during coating. Unless this discovery is made, less catalyst in the pressure sensitive adhesive composition results in longer cure times and potentially poor cure. The catalyst in the release coating can reduce or eliminate the amount of catalyst in the pressure sensitive adhesive composition and provide a long pot life during manufacture while providing less cure time after coating.

  Not all of the above activities in the detailed description or examples are required, some of the specific activities may not be required, and one or more additional activities may be performed in addition to the above Note that you get. Furthermore, the order in which activities are listed is not necessarily the order in which they are performed.

  In the foregoing specification, the concepts are described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense and all such modifications are intended to be included within the scope of the invention.

  The terms “comprises”, “comprising”, “includes”, “including”, “has”, “having” or any other variation thereof is , As used herein, is intended to cover non-exclusive inclusions. For example, a process, method, article or device that includes an enumeration of features is not necessarily limited to only those features, but is not explicitly listed or includes other features specific to such processes, methods, articles or devices. May be. Further, unless expressly stated to the contrary, “or” refers to generic “or” rather than exclusive “or”. For example, condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or does not exist), A is false (or does not exist) and B is true (or Present), and A and B are true (or present).

  Also, the use of “a” or “an” is used to describe the elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

  Benefits, other advantages, and solutions to the problems have been described above with regard to specific embodiments. However, the benefits, advantages, and solutions to the problem, as well as any features that may give rise to or become more obvious any benefit, advantage, or solution, are not exact in any or all of the claims Should not be construed as required or required features.

Those skilled in the art, after reading the specification, may have given certain features described herein in the context of separate embodiments in combination in a single embodiment for clarity. You will recognize the good. Conversely, various features that are described in the context of a single embodiment for the sake of brevity may be imparted separately or in any subcombination. Further, reference to values stated in ranges include each and every value within that range.

Claims (15)

A base film having first and second major surfaces;
An adhesive layer provided on the first main surface of the base film and containing a curable composition;
A multilayer film comprising: a release layer provided on the pressure-sensitive adhesive layer on the opposite side of the base film and including a release material and a catalyst configured to cure the curable composition.   The multilayer film according to claim 1, wherein the release material is a silicone-based, fluorine-based, long-chain alkyl-based, fatty acid amide-based, silica powder material, or any combination thereof.   The multilayer film of claim 1, wherein the curable composition comprises a polymer including natural rubber, styrenic block copolymer, acrylate, polyurethane, silicone, polydiorganosiloxane polyurea copolymer, or any combination thereof.   The multilayer film of claim 1, wherein the curable composition comprises a crosslinking agent.   The multilayer film according to claim 1, wherein the catalyst is an organometallic catalyst, an amine catalyst, or a combination thereof.   The multilayer film according to claim 1, wherein the base film includes an antistatic layer.   The multilayer film of claim 6, wherein the antistatic layer comprises a dissipative polymer.   The multilayer film of claim 6, wherein the antistatic layer comprises a conductive filler. The multilayer film according to claim 6, wherein the antistatic layer has a surface resistivity in the range of 10 ⁵ to 10 ¹² Ω / sq.   The multilayer film of Claim 1 which further contains the liner film provided in the said mold release layer on the opposite side to the said adhesive layer.   The liner film is polyolefin, acetate, acrylic, polyaryletherketone, polyester, polyether, polycarbonate, polyvinyl chloride, polyamide, polyimide, thermoplastic elastomer, styrene polymer, liquid crystal polymer, fluoropolymer, or any combination thereof The multilayer film according to claim 10, comprising:   The multilayer film of claim 1, wherein the curable composition has a peel strength in the range of 2 g / inch to 500 g / inch.   The multilayer film of claim 1, wherein the multilayer film has a cure index of 2 or less. The multilayer film of claim 1, wherein the curable composition comprises a polymer and a cross-linking agent; and the multilayer film further comprises a liner film on the release layer. A method of forming a multilayer film comprising:
Dispensing a substrate having first and second major surfaces;
Coating the first major surface of the substrate with a curable adhesive composition;
In coating with a release coating and contacting the curable adhesive composition, the release coating includes a release material and a catalyst configured to cure the curable adhesive composition. And said contacting.

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