Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
  • C09J7/22—Plastics; Metallised plastics
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
  • C09J7/29—Laminated material
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
  • C09J7/38—Pressure-sensitive adhesives [PSA]
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
  • G02F1/1336—Illuminating devices
  • G02F1/133602—Direct backlight
  • G02F1/133605—Direct backlight including specially adapted reflectors
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/02—Elements
  • C08K3/04—Carbon
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2301/00—Additional features of adhesives in the form of films or foils
  • C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
  • C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
  • C09J2301/124—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present on both sides of the carrier, e.g. double-sided adhesive tape
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2301/00—Additional features of adhesives in the form of films or foils
  • C09J2301/40—Additional features of adhesives in the form of films or foils characterized by the presence of essential components
  • C09J2301/408—Additional features of adhesives in the form of films or foils characterized by the presence of essential components additives as essential feature of the adhesive layer
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2301/00—Additional features of adhesives in the form of films or foils
  • C09J2301/40—Additional features of adhesives in the form of films or foils characterized by the presence of essential components
  • C09J2301/41—Additional features of adhesives in the form of films or foils characterized by the presence of essential components additives as essential feature of the carrier layer
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2323/00—Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
  • C09K2323/05—Bonding or intermediate layer characterised by chemical composition, e.g. sealant or spacer
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/133308—Support structures for LCD panels, e.g. frames or bezels
  • G02F1/133317—Intermediate frames, e.g. between backlight housing and front frame
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F2202/00—Materials and properties
  • G02F2202/28—Adhesive materials or arrangements
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
  • Y10T156/10—Methods of surface bonding and/or assembly therefor
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/28—Web or sheet containing structurally defined element or component and having an adhesive outermost layer
  • Y10T428/2804—Next to metal

Definitions

• the invention relates to double-sided PSA tapes with multilayer carrier structures and with light-reflecting and light-absorbing properties for the production of liquid crystal displays (LCDs).
• LCDs liquid crystal displays
• Pressure sensitive adhesive tapes are widely used processing aids in the age of industrialization. Especially for use in the computer industry very high demands are placed on pressure-sensitive adhesive tapes. In addition to a low outgassing behavior, the pressure-sensitive adhesive tapes should be usable over a wide temperature range and fulfill certain optical properties.
• a field of application are LCD displays that are needed for computers, televisions, laptops, PDAs, mobile phones, digital cameras, etc.
• a very common type of LCD module for such applications is shown in FIG.
• Fig. 1 shows the concept of a double-sided adhesive tape with a black absorption layer and a white reflection layer according to the prior art
• LEDs light emitting diodes
• LCD glass For the production of LC displays LEDs (light emitting diodes) are glued as a light source with the LCD glass.
• black double-sided pressure-sensitive adhesive tapes are usually used. The purpose of the black coloring is to ensure that no light penetrates from the inside to the outside and vice versa in the region of the double-sided pressure-sensitive adhesive tape.
• a concept for the production of black double-sided pressure-sensitive adhesive tapes consists in the coloring of the carrier material.
• very preferably double-sided pressure-sensitive adhesive tapes with polyester film carriers (PET) are used, since they can be punched very well.
• PET polyester film carriers
• the PET supports can be dyed with carbon black or black color pigments to achieve absorption of the light.
• the disadvantage of this existing concept is the low absorption of the light. In very thin carrier layers, only a relatively small number of carbon black particles or other black pigment particles can be introduced, with the result that complete absorption of the light is not achieved. With the eye and also with more intense light sources (light intensity greater than 600 candela) then the lack of absorption can be determined.
• Another concept for producing black double-sided pressure-sensitive adhesive tapes relates to the production of a two-layered support material by means of coextrusion.
• Carrier films are usually produced by extrusion.
• Coextrusion coextrudes, in addition to the conventional support material, a second black layer which fulfills the function of light absorption.
• This concept also has several disadvantages. For example, anti-blocking agents must be used for the extrusion, which then lead to the so-called pinholes in the product. These pinholes are optical defects (light transmission at these holes) and negatively affect the operation in the LCD.
• Another problem is the layer thicknesses, since the two layers are first formed individually in the nozzle and thus can be realized in total only relatively thick carrier layers, with the result that the film is relatively thick and inflexible and thus to the surfaces to be bonded only still badly fits.
• the must black layer also be relatively thick, otherwise no complete absorption can be realized.
• Another disadvantage is the changed mechanical properties of the carrier material, since the black layer has different mechanical properties to the original carrier material (eg pure PET).
• Another disadvantage for the two-layer version of the carrier material is the different anchoring of the adhesive on the coextruded carrier material. In this case, there is always a weak spot in the double-sided tape.
• a black color coat is coated on the support material. This can be done on one or both sides of the carrier. This too
• the maximum absorption properties do not meet the requirements, since only relatively thin paint layers can be applied. Here, too, one is limited in the layer thicknesses upwards, since otherwise the mechanical properties of the carrier material would change.
• the double sided pressure sensitive adhesive tape should be reflective.
• double-sided pressure-sensitive adhesive tapes which have a black light-absorbing layer and a white or metallic layer on one side (see also Fig. 1 for the concept of a double-sided adhesive tape with a black absorption layer and a white reflection layer.
• Fig. 1 for the concept of a double-sided adhesive tape with a black absorption layer and a white reflection layer.
• double-sided pressure-sensitive adhesive tapes with a white and a black layer have process advantages over double-sided pressure-sensitive adhesive tapes with a metallic and a black layer, since positioning in the LCD in black / metallic pressure-sensitive adhesive tape punches easily involves kinks, which then have a directly negative effect on the reflective properties ,
• a reflective layer e.g. reflective particles are mixed into the PSA.
• the achievable reflective properties are insufficient.
• JP 2002-350612 describes double-sided adhesive tapes for LCD panels with light-protective properties.
• the function is achieved by a metal layer, which is applied on one or both sides of the carrier film, wherein the carrier film may additionally be colored.
• the adhesive tapes described there have only this function and thus do not connect the light-absorbing function on one side and the light-reflecting function on the other side.
• JP 2002-023663 also describes double-sided adhesive tapes for LCD panels with light-protective properties. Again, the function is achieved by a metal layer which is applied on one or both sides of the carrier film.
• the object of the invention is therefore to provide a double-sided pressure-sensitive adhesive tape, which avoids the pinholes and is able to completely absorb light, and which has an improved reflection of light.
• the invention thus relates to pressure-sensitive adhesive tapes, in particular for the production or bonding of optical liquid-crystal data displays (LCDs), comprising a top and a bottom, with light-reflecting properties on the top and light-absorbing properties on the bottom, further comprising a carrier film with a top and a underside, wherein the pressure-sensitive adhesive tape is provided on both sides with a PSA layer, and wherein the carrier film is light, especially white, and the pressure-sensitive adhesive layer on the underside of the pressure-sensitive adhesive tape is not transparent, in particular black colored.
• LCDs optical liquid-crystal data displays
• the pressure-sensitive adhesive tape of the invention consists of a white carrier film layer (a), a transparent PSA layer (b) and a non-transparent, especially carbon black-colored, pressure-sensitive adhesive layer (b) '.
• the double-sided pressure-sensitive adhesive tape consists of a white carrier film (a), a transparent pressure-sensitive adhesive layer (b) and a non-transparent, especially carbon black-colored pressure-sensitive adhesive layer (b) 'and a metallic layer (c).
• FIG. 4 shows an embodiment in which the double-sided pressure-sensitive adhesive tape consists of a white carrier film (a), a metallically reflecting layer (c), a transparent pressure-sensitive adhesive layer (b) and a non-transparent pressure-sensitive adhesive layer (b) colored in particular with carbon black. and a black lacquer layer (d).
• the carrier film (a) is preferably between 5 and 250 .mu.m, more preferably between 8 and 50 .mu.m, most preferably between 12 and 36 .mu.m thick, bright, in particular colored white and of very low light transmission.
• the layer (c) is metallic shiny and reduces the light absorption of the inventive pressure-sensitive adhesive tape.
• the film (a) is finished with a silver-colored coating and / or, in a preferred embodiment of the invention, vapor-coated on one side with aluminum or silver.
• the layer thickness of the layer (c) is preferably between 5 nm and 200 nm.
• the layer (d) is a black-colored lacquer layers, which preferably has a layer thickness between 0.01 and 5 microns.
• the pressure-sensitive adhesive layers (b) and (b) ' can be of different chemical nature, (b)' contains different color-bearing pigments, which have an advantageous effect on the light-absorbing properties and appear black.
• the pressure-sensitive adhesive layers (b) and (b) ' preferably have a thickness of 5 ⁇ m to 250 ⁇ m, respectively.
• the individual layers (b), (b 1 ), (c) and (d) can differ within the double-sided pressure-sensitive adhesive tape in terms of layer thickness, so that, for example, different thickness PSA layers can be applied, but some or all of the Layers are designed to be the same thickness, so that, for example, advantageously equally thick PSA layers can be present on both sides of the adhesive tape.
• Carrier film (a)
• all filmic polymer supports which can be dyed white can be used as the film supports.
• polyethylene, polypropylene, polyimide, polyester, polyamide, polymethacrylate, fluorinated polymer films, etc. can be used.
• polyester films are used, particularly preferably PET films (polyethylene terephthalate).
• PET films polyethylene terephthalate
• the films may be relaxed or have one or more preferred directions. Preferred directions are achieved by stretching in one or two directions.
• PET films are usually antiblocked, such as e.g. Silica, chalk or chalk, zeolites used.
• PET films are outstandingly suitable, since they allow very good adhesive properties for the double-sided adhesive tape, since the film is very flexible and can easily adapt to the surface roughness of the substrates to be bonded.
• the films are preferably pretreated.
• the films may be etched (e.g., with trichloroacetic acid or trifluoroacetic acid), pretreated with corona or plasma, or equipped with a primer (e.g., saran).
• the film contains color pigments or color-bearing particles, from which a
• titanium dioxide additives one differentiates between anatase and
• Rutile structure The differences show, for example, in the refractive indices, the
• the white pigments can also be combined with organic radicals. Furthermore, the white pigments can also be combined with organic radicals.
• the pigments or particles should advantageously always be smaller in diameter than the final layer thickness of the carrier film. Optimal colorations can be achieved with 5 to 40 wt .-% of particles based on the film material.
• the pressure-sensitive adhesives (b) and (b ') on both sides of the pressure-sensitive adhesive tape are preferably different.
• pressure-sensitive adhesive systems based on acrylate, natural rubber, synthetic rubber, silicone or EVA adhesives can be used as the raw material basis.
• the pressure-sensitive adhesive (b) should have a high transparency.
• natural rubber adhesives can be used for (b) and (b ').
• the natural rubber is not ground to a molecular weight (weight average) below about 100,000 daltons, preferably not below 500,000 daltons and additized.
• weight average molecular weight below about 100,000 daltons, preferably not below 500,000 daltons and additized.
• Natural rubbers or synthetic rubbers or any blends of natural rubbers and / or synthetic rubbers can be used, the natural rubber or the natural rubbers in principle from all available qualities such as Crepe, RSS, ADS, TSR or CV types, depending on the required purity and viscosity level, and the synthetic rubber or the synthetic rubbers from the group of the random copolymerized styrene-butadiene rubbers (SBR), the butadiene rubbers (BR), the synthetic polyisoprenes (IR), the butyl rubbers (NR), the halogenated Butyl rubbers (XIIR), the acrylate rubbers (ACM), the ethylene-vinyl acetate copolymers (EVA) and the polyurethanes and / or their blends can be selected.
• SBR random copolymerized styrene-butadiene rubbers
• BR butadiene rubbers
• IR synthetic polyisoprenes
• NR butyl rubbers
• XIIR
• thermoplastic elastomers having a weight fraction of from 10 to 50% by weight, based on the total elastomer content.
• SIS styrene-isoprene-styrene
• SBS styrene-butadiene-styrene
• (meth) acrylate PSAs are preferably used for (b) and (b 1 ).
• (Meth) acrylate PSAs which are obtainable by free-radical polymerization advantageously comprise at least 50% by weight of at least one acrylic monomer from the group of compounds of the following general formula:
• the monomers are preferably chosen such that the resulting polymers can be used as pressure-sensitive adhesives at room temperature or higher temperatures, in particular such that the resulting polymers have pressure-sensitive adhesive properties according to the Handbook of Pressure Sensitive Adhesive Technology by Donatas Satas (van Nostrand, New York 1989).
• the comonomer composition is selected such that the PSAs can be used as heat-activable PSAs.
• the molar masses M w of the polyacrylates used are preferably M w > 200,000 g / mol.
• acrylic or methacrylic monomers which consist of acrylic and methacrylic acid esters having alkyl groups of 4 to 14 carbon atoms, preferably 4 to 9 carbon atoms.
• Specific examples without getting through this To limit enumerate are Methlacrylat, methyl methacrylate, ethyl acrylate, n-butyl acrylate, n-butyl methacrylate, n-pentyl acrylate, n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, n-octyl methacrylate, n-nonyl acrylate, lauryl acrylate, stearyl acrylate , Behenyl acrylate, and their branched isomers, such as isobutyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, isooct
• cycloalkyl alcohols consisting of at least 6 C atoms.
• the cycloalkyl alcohols may also be substituted, e.g. by C 1-6 -alkyl groups, halogen atoms or cyano groups.
• Specific examples are cyclohexyl methacrylates, isobornyl acrylate, isobornyl methacrylates and 3,5-
• monomers which contain polar groups such as carboxyl radicals, sulfonic and phosphonic acids, hydroxyl radicals, lactam and lactone, N-substituted amide, N-substituted amine, carbamate, epoxy, thiol, alkoxy. Cyan radicals, ethers or the like wear.
• Moderate basic monomers are N, N-dialkyl-substituted amides, such as N 1 N-dimethylacrylamide, N, N-Dimethylmethylmethacrylamid, N-tert-butylacrylamide, N-vinylpyrrolidone, N-vinyllactam, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl methacrylate, diethylaminoethyl acrylate, N - Methylolmethacrylamid, N- (Buthoxymethyl) methacrylamide, N-methylolacrylamide, N- (ethoxymethyl) acrylamide, N-isopropylacrylamide, this list is not exhaustive.
• hydroxyethyl acrylate hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, allyl alcohol, maleic anhydride,
• Itaconic anhydride itaconic acid, glyceridyl methacrylate, phenoxyethyl acrylate,
• photoinitiators having a copolymerizable double bond are used.
• Suitable photoinitiators are Norrish I and II photoinitiators. Examples are, for example, benzoin acrylate and an acrylated benzophenone from the company. UCB (Ebecryl P 36 ® ).
• UCB Ebecryl P 36 ®
• all photoinitiators known to those skilled in the art can be copolymerized, which can crosslink the polymer via UV irradiation via a radical mechanism.
• monomers which have a high static glass transition temperature are added to the comonomers described.
• Suitable components are aromatic vinyl compounds, such as, for example, styrene, wherein the aromatic nuclei preferably consist of C 4 - to cis units and may also contain heteroatoms.
• Particularly preferable examples are 4-vinylpyridine, N-vinylphthalimide, methylstyrene, 3,4-dimethoxystyrene, 4-vinylbenzoic acid, benzylacrylate, benzylmethacrylate, phenylacrylate, phenylmethacrylate, t-butylphenylacrylate, t-butylphenylmethacrylate, 4-biphenylacrylate and -methacrylate, 2-naphthylacrylate and methacrylate and mixtures of those monomers, this list is not exhaustive.
• the refractive index of the PSA increases and the scattering between the LCD glass and the PSA by e.g. Ambient light is minimized.
• the PSAs may be mixed with resins.
• Suitable tackifying resins to be added are the previously known adhesive resins described in the literature. Mention may be made of the pinene, indene and rosins, their disproportionated, hydrogenated, polymerized, esterified derivatives and salts, the aliphatic and aromatic hydrocarbon resins, terpene resins and terpene phenolic resins, and C5, C9 and other hydrocarbon resins. Any combination of these and other resins can be used to adjust the properties of the resulting adhesive as desired. In general, all (soluble) resins compatible with the corresponding polyacrilate can be used; in particular, reference is made to all aliphatic, aromatic, alkylaromatic hydrocarbon resins,
• Hydrocarbon resins based on pure monomers, hydrogenated hydrocarbon resins, functional hydrocarbon resins and natural resins.
• the presentation of the state of knowledge in the "Handbook of Pressure Sensitive Adhesive Technology" by Donatas Satas (van Nostrand, 1989) is expressly pointed out.
• optional fillers such as fibers, carbon black, zinc oxide, chalk, solid or hollow glass spheres, microspheres of other materials, silicic acid, silicates
• nucleating agents such as, for example, the plasticizers (plasticizers).
• such additives may be added only in amounts that do not affect the reflection of the metallic layer.
• the pressure-sensitive adhesives (b) and (b 1 ) differ only in the black particle additive.
• the pressure-sensitive adhesive (b 1 ) preferably contains between 2 and 30% by weight of carbon black, more preferably between 5 and 20% by weight of carbon black and most preferably between 8 and 15% by weight of carbon black.
• the soot has a light-absorbing function.
• Pigment blacks have proven to be outstandingly suitable.
• carbon black powders from Degussa are used. These are commercially available under the trade name Printex TM. For better dispersibility into the PSA it is particularly preferred to use oxidatively after-treated blacks.
• the pressure-sensitive adhesive (b ') of Be beneficial if in addition to carbon black color pigments are added.
• blue pigments such as aniline black BS890 from Degussa are suitable as additives.
• matting agents can be used as additives.
• the pressure-sensitive adhesive (b) and (b 1 ) differ not only in the black particle addition, but also in their chemical composition.
• different polyacrylates can be used as base material, which differ in the comonomers and / or in the additization.
• the layer (b 1 ) for example, natural rubber or synthetic rubber adhesives and to combine these with a transparent acrylic PSA (b).
• the pressure-sensitive adhesive (b 1 ) also preferably contains between 2 and 30% by weight of carbon black, more preferably between 5 and 20% by weight of carbon black and most preferably between 8 and 15% by weight of carbon black.
• the special carbon blacks and / or color pigments mentioned in the preceding section are also very advantageous here.
• crosslinkers and promoters can be admixed with the PSAs (b) and / or (b 1 ) for crosslinking.
• Suitable crosslinkers for electron beam crosslinking and UV crosslinking are, for example, difunctional or polyfunctional acrylates, difunctional or polyfunctional isocyanates (also in blocked form) or difunctional or polyfunctional epoxides.
• thermally activatable crosslinkers such as, for example, Lewis acid, metal chelates or multifunctional isocyanates.
• UV-absorbing photoinitiators For optional crosslinking with UV light, it is possible in particular to add UV-absorbing photoinitiators to the PSAs (b) and / or (b 1 ). helpful
• Photoinitiators which are very easy to use, benzoin ethers, such.
• Dimethoxy-2-phenyl-1-phenylethanone dimethoxyhydroxyacetophenone, substituted ⁇ -ketols, such as.
• 2-methoxy-2-hydroxypropiophenone aromatic sulfonyl chlorides, such as.
• 2-naphthyl sulfonyl chloride and photoactive oximes, such as. 1-phenyl-1,2-propanedione
• the above-mentioned and other usable Photoinititatioren and others of the type Norrish-I or Norrish-Il may advantageously contain the following radicals: benzophenone, Acetophenone, benzil, benzoin, hydroxyalkylphenone, phenylcyclohexylketone, anthraquinone, trimethylbenzoylphosphine oxide, methylthiophenylmorpholinketone, aminoketone, azobenzoin, thioxanthone, hexarylbisimidazole, triazine or fluorenone, each of these radicals additionally having one or more a plurality of halogen atoms and / or one or more alkoxy groups and / or one or more amino groups or hydroxy groups may be substituted.
• the monomers are advantageously chosen such that the resulting polymers can be used as PSAs at room temperature or higher temperatures, in particular in such a way that the resulting polymers have pressure-sensitive adhesive properties in accordance with Donatas Satas' Handbook of Pressure Sensitive Adhesive Technology (van Nostrand, vol. New York 1989).
• T G of the polymers of T G ⁇ 25 ° C. the monomers are very preferably selected in accordance with the above and the quantitative composition of the monomer mixture is advantageously selected such that, according to an equation (G1) analogously to the Fox equation (G1) (see TG Fox, Bull. Am. Phys Soc., 1 (1956) 123) gives the desired T G value for the polymer.
• n the number of runs via the monomers used
• W n the mass fraction of the respective monomer n (wt .-%)
• T G the respective glass transition temperature of the homopolymer of the respective monomers n in K.
• radical sources are peroxides, hydroperoxides and azo compounds
• typical free-radical initiators are potassium peroxodisulfate, dibenzoyl peroxide, cumene hydroperoxide, cyclohexanone peroxide, di-t-butyl peroxide, Azodiisoklarebutyronitril, Cyclohexylsulfonylacetylperoxid, diisopropyl percarbonate, t-butyl peroctoate, Benzpinacol.
• 1, 1'-azobis cyclohexanecarboxylic acid nitrile
• Vazo 88 TM from DuPont
• AIBN azodisobutyronitrile
• the average molecular weights M w of the PSAs formed in the free-radical polymerization are very preferably selected such that they are in a range from 200,000 to 4,000,000 g / mol; In particular, pressure-sensitive adhesives having average molecular weights M w of 400,000 to 1,400,000 g / mol are produced.
• the determination of the average molecular weight is carried out by size exclusion chromatography (GPC) or matrix-assisted laser desorption / ionization mass spectrometry (MALDI-MS).
• the polymerization may be carried out neat, in the presence of one or more organic solvents, in the presence of water or in mixtures of organic solvents and water.
• Suitable organic solvents are pure alkanes (eg hexane, heptane, octane, isooctane), aromatic hydrocarbons (eg benzene, toluene, xylene), esters (eg ethyl acetate, propyl, butyl or hexyl acetate), halogenated hydrocarbons (eg chlorobenzene) , Alkanols (eg methanol, ethanol, ethylene glycol,
• Ethylene glycol monomethyl ether and ethers (eg, diethyl ether, dibutyl ether) or mixtures thereof.
• the aqueous polymerization reactions can be treated with a water-miscible or hydrophilic cosolvent to ensure that the reaction mixture is in the form of a homogeneous phase during the monomer conversion.
• Advantageously usable cosolvents for The present invention is selected from the following group consisting of aliphatic alcohols, glycols, ethers, glycol ethers, pyrrolidines, N-alkylpyrrolidinones, N-alkylpyrrolidones, polyethylene glycols, polypropylene glycols, amides, carboxylic acids and salts thereof, esters, organosulfides, sulfoxides, sulfones, alcohol derivatives , Hydroxy ether derivatives, aminoalcohols, ketones and the like, as well as derivatives and mixtures thereof.
• the polymerization time is - depending on the conversion and temperature - between 2 and 72 hours.
• the polymerization can be initiated for the thermally decomposing initiators by heating to 50 to 160 ° C., depending on the type of initiator.
• the preparation it may also be advantageous to polymerize the (meth) acrylate PSAs in substance.
• the recuperymerisationstechnik is suitable here.
• the polymerization is initiated with UV light, but only to a low conversion about 10 - 30% out.
• this polymer syrup may e.g. are shrink-wrapped in films (in the simplest case ice cubes) and then polymerized in water to high sales.
• These pellets can then be used as acrylate hotmelt adhesives, with film materials which are compatible with the polyacrylate being used with particular preference for the melting process.
• the thermally conductive material additives can be added before or after the polymerization.
• poly (meth) acrylate pressure-sensitive adhesive compositions is anionic polymerization.
• inert solvents are preferably used as the reaction medium, e.g. aliphatic and cycloaliphatic hydrocarbons, or aromatic hydrocarbons.
• the living polymer in this case is generally represented by the structure P L (A) -Me, where Me is a Group I metal, such as lithium, sodium or potassium, and P L (A) is a growing polymer of the acrylate monomers ,
• the molecular weight of the polymer to be prepared is controlled by the ratio of initiator concentration to monomer concentration.
• Suitable polymerization initiators are, for example, n-propyllithium, n-butyllithium, sec-butyllithium, 2-naphthyllithium, cyclohexyl lithium or octyllithium, although this list is not exhaustive.
• initiators based on samarium complexes for the polymerization of acrylates are known (Macromolecules, 1995, 28, 7886) and can be used here.
• difunctional initiators such as 1, 1, 4 J 4-tetraphenyl-1 J 4-dilithiobutane or i .i ⁇ - tetraphenyl-i ⁇ -dilithioisobutan.
• Co-initiators can also be used. Suitable coinitiators include lithium halides, alkali metal alkoxides or alkylaluminum compounds.
• the ligands and coinitiators are chosen so that acrylate monomers, such as n-butyl acrylate and 2-ethylhexyl acrylate, can be polymerized directly and need not be generated in the polymer by transesterification with the corresponding alcohol.
• control reagent of the general formula is then preferably used:
• R and R 1 are independently selected or the same and - branched and unbranched d- to Ci 8 alkyl radicals; C 3 to C 8 alkenyl radicals; C 3 to Cis alkynyl radicals;
• Cis-alkyl radicals C 3 -C 8 -alkenyl radicals, C 3 -C 8 -alkynyl radicals;
• Control reagents of type (I) preferably consist of the following compounds:
• Halogen atoms are in this case preferably F, Cl, Br or I, more preferably Cl and Br.
• Alkyl, alkenyl and alkynyl radicals in the various substituents are outstandingly suitable for both linear and branched chains.
• alkyl radicals containing 1 to 18 carbon atoms are methyl, ethyl,
• alkenyl radicals having 3 to 18 carbon atoms are propenyl, 2-butenyl, 3-butenyl, isobutenyl, n-2,4-pentadienyl, 3-methyl-2-butenyl, n-2-octenyl, n-2-dodecenyl,
• alkynyl of 3 to 18 carbon atoms examples include propynyl, 2-butynyl, 3-butynyl, n-2-octynyl and n-2-octadecynyl.
• hydroxy-substituted alkyl radicals are hydroxypropyl, hydroxybutyl or hydroxyhexyl.
• halogen-substituted alkyl radicals are dichlorobutyl, monobromobutyl or
• Carbon chain is, for example, -CH 2 -CH 2 -O-CH 2 -CH 3 .
• C 3 -C 2 cycloalkyl radicals for example, cyclopropyl, cyclopentyl, cyclohexyl or trimethylcyclohexyl serve.
• C 6 -C 8 -aryl radicals serve, for example, phenyl, naphthyl, benzyl, 4-tert-butylbenzyl or other substituted phenyl, such as ethyl, toluene, xylene, mesitylene, isopropylbenzene,
• R 2 can also be selected independently of R and R 1 from the above-mentioned group for these radicals.
• polymerisation is usually carried out only to low conversions (WO 98/01478 A1) in order to realize the narrowest possible molecular weight distributions. Due to the low conversions, however, these polymers can not be used as pressure-sensitive adhesives and in particular not as hotmelt PSAs, since the high proportion of residual monomers adversely affects the adhesive properties, the residual monomers in the concentration process contaminate the solvent recycled and the corresponding self-adhesive tapes show a very high outgassing behavior. In order to avoid this disadvantage of lower conversions, in a particularly preferred procedure the polymerization is initiated several times.
• nitroxide-controlled polymerizations can be carried out.
• radical stabilization nitroxides of the type (Va) or (Vb) are used in a favorable procedure:
• R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 independently represent the following compounds or atoms: i) halides, such as chlorine, bromine or iodine ii) linear, branched, cyclic and heterocyclic hydrocarbons having 1 to
• Compounds of (Va) or (Vb) may also be bound to polymer chains of any kind (primarily in the sense that at least one of the above radicals represents such a polymer chain) and thus be used for the construction of polyacrylate PSAs.
• controlled regulators are chosen for the polymerization of compounds of the type:
• TEMPO 2,2,6,6-tetramethyl-piperidine-1-oxyl
• 4-benzoyloxy-TEMPO 4-methoxy-TEMPO
• 4-chloro-TEMPO 4-hydroxy-TEMPO
• 4-oxo-TEMPO 4-amino-TEMPO, 2,2,6,6, -tetraethyl-1-piperidinyloxy, 2,2,6-trimethyl-6-ethyl-1-piperidinyloxy • N-tert-butyl-1-phenyl-2 methyl propyl nitroxide
• No. 4,581,429 A discloses a controlled-free radical polymerization process which uses as initiator a compound of the formula R'R "NOY, in which Y is a free radical species capable of polymerizing unsaturated monomers, but the reactions generally have low conversions WO 98/13392 A1 describes open-chain alkoxyamine compounds which have a symmetrical substitution pattern
• EP 735 052 A1 discloses a process for the preparation of thermoplastic elastomers having narrow molecular weight distributions
• WO 96/24620 A1 describes a polymerization process employing very specific radical compounds such as phosphorus-containing nitroxides based on imidazolidine
• WO 98/44008 A1 discloses specific nitroxyls based on morpholines, piperazinones and piperazine diones DE 199 49 352 A1 describes heterocyclic compounds al koxyamine as regulators in controlled radical polymerizations.
• ATRP polyacrylate PSA atom transfer radical polymerization
• halide e
• Cu, Ni , Fe, Pd, Pt, Ru, Os, Rh, Co, Ir, Ag or Au complexes EP 0 824 111 A1, EP 826 698 A1, EP 824 110 A1, EP 841 346 A1, EP 850 957 A1.
• ATRP atom transfer radical polymerization
• the PSA is coated from solution onto the carrier material in a preferred procedure.
• layers (a) and / or (b) can optionally be pretreated.
• the solvent is removed via heat supply, for example in a drying tunnel, and optionally the crosslinking reaction is initiated.
• the polymers described above can furthermore also be coated as hotmelt systems (ie from the melt). For the production process, it may therefore be necessary to remove the solvent from the PSA.
• a very preferred method is concentration over a single or twin screw extruder.
• the twin-screw extruder can be operated in the same direction or in opposite directions.
• the solvent or water is preferably distilled off over several vacuum stages. In addition, depending on the distillation temperature of the solvent is heated counter.
• the residual solvent contents are preferably ⁇ 1%, more preferably ⁇ 0.5% and very preferably ⁇ 0.2%.
• the twin-screw extruder can also be used for compounding with the carbon black. In this way, the carbon black can be distributed very finely distributed in the pressure-sensitive adhesive matrix.
• the hotmelt is very preferably processed from the melt.
• the PSAs are coated by a roll coating process. Different roll coating processes are described in the Handbook of Pressure Sensitive Adhesive Technology by Donatas Satas (van Nostrand, New York 1989), in another embodiment a melt die is coated, in another preferred process extrusion is applied
• the extrusion dies used may advantageously come from one of the following three categories: T-die, fish-tail die and stirrup nozzle The individual types differ in the shape of their flow channel.
• the coating can also give the PSAs orientation.
• crosslinking is effected with electron and / or UV radiation.
• UV crosslinking is irradiated by short-wave ultraviolet irradiation in a wavelength range of 200 to 400 nm, depending on the UV photoinitiator used, in particular using high-pressure or medium-pressure mercury lamps at a power of 80 to 240 W / cm ,
• the irradiation intensity is adapted to the respective quantum yield of the UV photoinitiator and the degree of crosslinking to be set.
• Typical irradiation devices that can be used are linear cathode systems, scanner systems or segmented cathode systems, if it is an electron beam accelerator.
• the typical acceleration voltages are in the range between 50 kV and 500 kV, preferably 80 kV and 300 kV.
• the applied waste cans range between 5 to 150 kGy, in particular between 20 and 100 kGy.
• a silver-colored lacquer can be applied to the foil layer (a) and / or the foil layer (a) can be vapor-coated on one side with a metal, eg aluminum or silver.
• a binder matrix is mixed with silver color pigments. Suitable binder matrix are, for example, polyurethanes or polyesters which have a high refractive index and high transparency.
• the color pigments can also be incorporated in a polyacrylate or polymethacrylate matrix and then cured as a lacquer.
• the film layer (a) is instead or additionally vapor-coated on one side with aluminum or silver.
• the sputtering process should be controlled so that the aluminum or silver is applied very uniformly to avoid pinholes.
• the color layer (d) can fulfill various functions.
• the color layer has the function of additional absorption of the external light. Therefore, in this case, for the double-sided pressure-sensitive adhesive tape, the transmittance in a wavelength range of 300 - 800 nm should be ⁇ 0.5%, more preferably ⁇ 0.1%, most preferably ⁇ 0.01%. In particular, this is achieved advantageously with a black lacquer layer.
• black color pigments are mixed into the paint matrix.
• varnish materials e.g. Polyesters, polyurethanes, polyacrylates or polymethacrylates are used in conjunction with the paint additives known to the person skilled in the art.
• carbon black or graphite particles are mixed into the binder matrix as coloring particles.
• an electrical conductivity is additionally achieved by this addition at very high additive content (> 20% by weight), so that the inventive double-sided pressure-sensitive adhesive tapes likewise have antistatic properties.
• the invention further relates to the use of the inventive double-sided pressure-sensitive adhesive tapes for bonding or producing optical liquid-crystal data displays (LCDs), the use for bonding LCD glasses and liquid-crystal data displays and devices with liquid-crystal data displays which comprise a pressure-sensitive adhesive tape according to the invention in its product structure exhibit.
• the double-sided pressure-sensitive adhesive tapes can with a or two release films and / or release papers.
• the transmission was measured in the wavelength range from 190 to 900 nm using a Uvikon 923 from the company Biotek Kontron.
• the Absolute Transmission is given as the value at 550 nm in%.
• a commercially very strong light source for example overhead projector type Liesegangtrainer 400 KC type 649, halogen lamp 36 V, 400 W
• This mask contains in the middle a circular opening with a diameter of 5 cm.
• the double-sided LCD tape is placed on this circular opening. In fully darkened surroundings, the number of pinholes is then counted electronically or visually. These are recognizable as translucent dots when the light source is switched on.
• the reflection test is carried out according to DIN standard 5063 part 3.
• the measuring instrument used was an Ulbrecht ball type LMT.
• the reflectance is given as the sum of directed and scattered light fractions in%.
• a 200 L reactor conventional for radical polymerizations was charged with 2400 g of acrylic acid, 64 kg of 2-ethylhexyl acrylate, 6.4 kg of N-isopropylacrylamide and 53.3 kg of acetone / isopropanol (95: 5). After 45 minutes, passing nitrogen gas while stirring, the reactor was heated to 58 0 C and added 40 g of 2,2'-azoisobutyronitrile (AIBN). Subsequently, the outer heating bath was heated to 75 ° C and the reaction was carried out constantly at this external temperature. After 1 h reaction time again 40 g of AIBN was added. After 5 h and 10 h each was diluted with 15 kg acetone / isopropanol (95: 5).
• AIBN 2,2'-azoisobutyronitrile
• Soot mass 1 In a drum, the polymer 1 is diluted with petroleum spirit to a solids content of 30%. Subsequently, with vigorous stirring, 8% by weight of carbon black (pigment black, Printex TM 25, Degussa AG), based on the polymer 1, is mixed in. For homogenization, the solution is homogenized for 10 minutes with an Ultratrurrax.
• carbon black pigment black, Printex TM 25, Degussa AG
• polymer 1 In a drum, polymer 1 is diluted with petroleum spirit to a solids content of 30%. Subsequently, with vigorous stirring, 10% by weight of carbon black (pigment black, Printex TM 25, Degussa AG), based on the polymer 1, is mixed in. For homogenization, the solution is homogenized for 10 minutes with an Ultratrurrax.
• carbon black pigment black, Printex TM 25, Degussa AG
• polymer 1 In a drum, polymer 1 is diluted with petroleum spirit to a solids content of 30%. Subsequently, with vigorous stirring, 12% by weight of carbon black (pigment black, Printex TM 25, Degussa AG), based on the polymer 1, is mixed in. For homogenization, the solution is homogenized for 10 minutes with an Ultraturrax. Networking
• the carbon blacks and polymer 1 are coated from solution onto a siliconized release paper (PE-coated release paper from Loparex), dried for 10 minutes in an oven at 100 ° C. and then crosslinked at a dose of 25 kGy at an acceleration voltage of 200 kV.
• the mass application was in each case 50 g / m 2
• the film was vapor-deposited at a width of 300 mm by the sputtering method.
• positively charged, ionized argon gas is fed into a high-vacuum chamber.
• the charged ions then strike a negatively charged Al plate and dissolve aluminum particles at the molecular level, which then deposit on the polyester film passed over the plate.
• the film 1 is coated in the lamination process with the polymer 1 on one side with 50 g / m 2 and on the metal-coated side with the soot mass 1 with 50 g / m 2 .
• the film 1 is coated in the lamination process with the polymer 1 on one side with 50 g / m 2 and on the metal-coated side with the soot mass 2 at 50 g / m 2 .
• the film 1 is coated in the lamination process with the polymer 1 on one side with 50 g / m 2 and on the metal-coated side with the soot mass 3 with 50 g / m 2 .
• Example 4 The film 2 is coated in the lamination process with the polymer 1 on one side with 50 g / m 2 and on the other side with the soot mass 1 with 50 g / m 2 .
• the film 2 is coated in the lamination process with the polymer 1 on one side with 50 g / m 2 and on the other side with the soot mass 2 with 50 g / m 2 .
• the film 2 is coated in the lamination process with the polymer 1 on one side with 50 g / m 2 and on the other side with the soot mass 3 with 50 g / m 2 .

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