MXPA99008009A - Pressure-sensitive adhesive tape - Google Patents

Abstract

The invention relates to a pressure-sensitive adhesive tape with improved room temperature handleability comprising an adhesive layer with at least one exposed surface and optionally a backing, wherein the pressure-sensitive adhesive layer comprises an epoxy/polyester based pressure sensitive adhesive which is cross-linkable upon exposure to actinic or e-beam irradiation and optionally heat, and comprises (i) 30-80%by weight of a polyester component comprising one or more amorphous polyesters compounds, (ii) 20-70%by weight of an epoxy component comprising one or more epoxy resins and/or monomers, (iii) 0-50%by weight of a hydroxyl-functional component containing one or more hydroxyl-containing compoundshaving a hydroxyl functionality of at least 1, and (iv) an effective amount of a photoinitiator component for cross-linking the pressure-sensitive adhesive, whereby the weight percentages refer to the total mass of components (i)-(iv) and add up to 100 wt.%, and which exhibits a holding power of at least 5 min.

Description

PRESSURE SENSITIVE ADHESIVE TAPE BACKGROUND OF THE INVENTION Field of the Invention This invention relates to a pressure sensitive adhesive tape with improved room temperature operability comprising at least one adhesive layer with at least one exposed surface and optionally one adhesive layer. support, wherein the pressure sensitive adhesive layer comprises an epoxy / polyester based pressure sensitive adhesive that is crosslinkable on exposure to actinic or electron beam irradiation. Furthermore, the invention is concerned with a method for gluing a first substrate to a second substrate when using such pressure sensitive adhesive tape and assembly or assembly prepared by such method.

Description of the Related Art U.S. Patent No. 4,920,182 describes UV-curable curable compositions comprising one or more epoxy resins having an average of at least two 1,2-epoxy groups per molecule, one or more flexible polyesters that are terminated on average by at least two carboxyl groups and a metallocene complex initiator. The composition, which can be used for the production of coatings REF; 31260 on a variety of substrates or as an adhesive, can be cured by the application of heat or with a combination of irradiation and heat. The curing temperature is generally 40-200 ° C, preferably 80-110 ° C. U.S. Patent No. 4,256,828 describes photocopolymerizable compositions containing epoxides, organic material with hydroxyl functionality such as hydroxyl terminated polyesters and a photosensitive aromatic sulfonium or iodonium salt of a complex ion containing hhalogen. The compositions can be used in a variety of applications, such as, for example, dye-curable inks, binders for abrasive particles, paints, adhesives, coatings for embossing and lithographic plates, protective coatings for metals, wood, etcetera. The compositions are normally coated on the respective surface and are photocurable at room temperature or at a lower temperature. The curable thermal melt compositions of European Patent Publication No. 0,620,259 comprise an epoxy component, a polyester component, a photoinitiator and optionally a hydroxyl-containing material. Thermal melt compositions, which may be adherent or non-adherent, may be applied to a variety of substrates by extrusion, spraying, etching or coating (e.g., when using a coating nozzle, a heated knife coating apparatus or roller or reverse roller coater). The thermal melt composition can also be applied as an uncured self-supporting adhesive film which, when used to bond a first substrate, can be irradiated on one or both sides and then placed between two substrates by the use of heat, pressure or both. heat and pressure to stick the film to the two substrates. Alternatively, it is possible to laminate the thermal melt adhesive film to a support at room temperature using a pressure of for example 0.7 Kg / cm2 (10 pounds / square inch) as suggested in U.S. Patent No. 5,436,063. This reference discloses a coated abrasive article comprising a support, a first binder on the support, a plurality of abrasive particles in the first binder and a second binder on the first binder and the abrasive particles. The first binder consists of a photocurable thermal fusion adhesive as described in European Patent Publication No. 0,620,259. While the crosslinkable thermal fusion epoxy / polyester-based adhesives described above have wide utility, there are certain specific applications where improved mechanical integrity and / or cohesion strength are desired or required. Therefore, there is a need for crosslinkable epoxy / polyester-based pressure sensitive adhesive materials available to those skilled in the art to enable them to select suitable adhesive materials that exhibit advantageous properties for a specific application and in particular, for the preparation of sensitive adhesive tapes under pressure, supported or not supported with improved and / or convenient handling at room temperature or at a lower temperature. Other objects of the present invention will appear from the specification detailed below.

BRIEF DESCRIPTION OF THE INVENTION The present invention is concerned with a pressure sensitive adhesive tape with improved room temperature handling comprising at least one layer of pressure sensitive adhesive with at least one exposed surface and optionally a support, wherein the pressure sensitive adhesive layer comprises an epoxy / polyester based pressure sensitive adhesive which is crosslinkable on exposure to actinic or electron beam irradiation and which comprises: i) 30-80% by weight of a a pousse component comprising one or more amorphous polyester compounds; ii) 20-70% by weight of an epoxy component comprising one or more epoxy resins and / or monomers, iii) 0-50% by weight of a hydroxy-functional component containing one or more hydroxyl-containing compounds that have a hydroxyl functionality of at least 1 / iv) an effective amount of a photoinitiator component for crosslinking the pressure sensitive adhesive; wherein the percentages by weight refer to the total mass of the components (i) - (iv) and add up to 100% by weight and wherein in addition the pressure-sensitive adhesive exhibiting a holding power of at least 5 minutes. The present invention is further concerned with a method for gluing a first substrate to a second substrate with a pressure sensitive adhesive tape according to the invention having two exposed adhesive surfaces. The method comprises the steps of applying the first exposed surface of the adhesive. pressure sensitive to the first substrate and joining the second substrate to the second exposed surface of the pressure sensitive adhesive whereby the layer of pressure sensitive adhesive according to the invention is subjected to actinic or electron beam irradiation and optionally heat before gluing them to the respective substrate at the post-cure bonding time or after bonding them to the respective substrates. The invention is also concerned with assemblies that are obtainable by such a method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The term "pressure-sensitive adhesive tape" as referred to above and below describes essentially two-dimensional articles supported or not supported such as sheets, tapes, strips or die-cut parts (ie, the extension of articles). in two directions the extension in the third direction exceeds distinctly): i) which are adherent or sticky at room temperature and can be applied to a wide variety of substrates by exerting for example finger pressure and ii) which can be conveniently handled lower temperatures such as room temperature without breaking, that is, exhibiting a sufficiently high internal resistance and sufficiently high cohesiveness and a certain elasticity such that separable inner liners or liners can be easily separated from the tape without damage to the tape and the tape can be stretched so less lightly and transferred to the substrate manually. Characteristic (i) requires an initial 90 ° peel adhesion value on stainless steel as measured 20 minutes after application on the substrate in accordance with the test method specified below of at least 4N / 2.54 cm (1 inch) or more. Feature (ii) requires a retention power time as measured according to the test method specified in the experimental part below, of at least 5 minutes or more. The epoxy / polyester based pressure sensitive adhesive tapes according to the present invention are crosslinkable and can be converted to crosslinked pressure sensitive adhesive tapes on exposure to actinic or electron beam radiation and optionally to heat. The pressure sensitive adhesive crosslinked can stick for example two substrates and the resulting configuration is referred to as a set or assembly. The term adhesive film as referred to above and below describes bidemsional articles which may be adherent or non-adherent at room temperature and exhibit a detachment or debonding time of less than 5 minutes and in particular of not more than 3 minutes. The pressure sensitive adhesive tapes of the present invention that can be supported or not supported exhibit at least one layer of pressure sensitive adhesive comprising an epoxy / polyester based pressure sensitive adhesive. It was found that in order to impart improved room temperature workability to pressure sensitive adhesive tapes it is essential that the polyester component (i) of the pressure sensitive adhesive comprises one or more amorphous polyester compounds. The amorphous polyesters are differentiated from the crystalline polyesters in that they do not exhibit a measurable crystalline melting point when a sample of about 8 milligrams is subjected to a scanning or DSC scanning (differential scanning (or scanning) calorimetry) at a rate of 20. ° C / minute, from -60 ° C to 200 ° C. DSC measurements are preferably carried out by using commercially available DSC equipment such as for example a scanning or differential scanning calorimeter DSC7 from Perkin Elmer, Norwalk, CT, United States of America. As long as they do not exhibit a crystalline melting point when subjected to the DSC described above, the amorphous polyester compounds exhibit a glass transition temperature which is preferably between -20 ° C and 50 ° C. Especially preferred are the compounds of amorphous polyesters with a glass transition temperature between -15 ° C and 25 ° C and more preferred between 0 and 25 ° C. The amorphous polyester compounds that can be used for the preparation of the tapes according to the present invention include hydroxyl and carboxyl-terminated materials. The softening point or temperature is preferably between 50 and 150 ° C, more preferably between 70 and 140 ° C and more preferably between 60 and 110 ° C. The molecular weight is preferably adjusted to give a melt flow rate of 200 ° C of between 10 and 300 g / minute and more preferably between 20 and 250 g / minute. The melt flow rate is measured according to the DIN ISO 1133 standard by placing approximately 10 g of the respective amorphous polyester compound in a temperature-conditioned metal cylinder. Via a cylindrical mold, a force of 21.6 N acts on the molten sample. The amount of sample flowing through a standard nozzle at a certain time is weighed and converted at a given flow rate in grams / minute. Preferred amorphous compounds also have a weight average in number of about 7,500 to 200,000 and more preferably about 10,000 to about 50,000 as determined by GPC (gel permeation chromatography) in THF (tetrahydrofuran) calibrated with polystyrene. The polyester compounds which are useful for the preparation of the tapes according to the present invention can be obtained, for example as reaction products of dicarboxylic acids (or their diester equivalents) and diols. Examples of aliphatic dicarboxylic acids are saturated aliphatic dicarboxylic acids, such as oxalic acid, malonic acid, succinic acid, a-methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid or dimerized linoleic acid; or unsaturated aliphatic polycarboxylic acids, such as maleic acid, fumaric acid, mesaconic acid, citraconic acid, glutaconic acid or itaconic acid and also possible anhydrides of these acids. Examples of cycloaliphatic dicarboxylic acids are hexahydrophthalic, hexahydroisophthalic or hexahydroterephthalic, tetrahydrophthalic, tetrahydroisophthalic or tetrahydro-terephthalic acid or 4-methyltetrahydrophthalic acid, 4-methylhexahydrophthalic acid or endomethylenetetrahydrophthalic acid. Examples of aromatic dicarboxylic acids are phthalic acid, isophthalic acid and terephthalic acid. Examples of functional carboxylic acids are tricarboxylic or tetracarboxylic acids, such as trimellitic acid, trimesic acid, pyromellitic acid or benzophenotetracarboxylic acid; or trimerized fatty acids or mixtures of dimerized and trimerized fatty acids, such as are commercially available for example under the tradename Pripol®. Combinations or mixtures of any of the above diacids or polyacids may also be employed. Examples of suitable aliphatic diols are: a,? -alkylenediols, such as ethylene glycol, propan-1,2-diol, propan-1,3-diol, butan-1, -diol, pentan-1,5-diol, neopentyl- glycol, hexan-1, 6-diol, octan-1, 8-diol, decan-1, 10-diol or dodecan-1, 12-diol. Examples of suitable cycloaliphatic diols are 1,3-dihydroxycyclohexane, 1,4-dihydroxy-cyclohexane, 1-cyclohexanedimethanol, bis-4- (hydroxy-cyclohexyl) -methane or 2,2-bis- (4-hydroxycyclohexyl) -propane. . Examples of suitable polyfunctional alcohols are 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol or pentaerythritol. Long chain diols including poly (oxyalkylene) glycols in which the alkylene group preferably contains 2 to 9 carbon atoms (more preferably 2 to 4 carbon atoms) may also be used. Combinations of any of the above diols or polyols may also be used.

Examples of di- or polycarboxylic acids, esters or anhydrides and di- or polyhydroxy compounds are only to illustrate the invention without limiting it. By reacting, for example, the dicarboxylic acids (or their diester equivalents) and the diols listed above may result in amorphous and / or semi-crystalline polystyrenes. The amorphous polyester compounds can be easily identified by subjecting them to DSC scanning or scanning as described above. Amorphous, instead of crystalline, polyester compounds can be obtained, for example, by reacting adducts with a high degree of stereoregularity that can not be effectively packaged in crystalline structures and impart a high degree of entropy to the resulting polymer. Details of the preparation of amorphous polymers can be found for example in Encyclopedia of Polymer Science and Engineering, New York 1988, vol. 12, pp. 1-312 and the references cited therein and in the Polymeric Materials Enclyclopedia, Boca Raton 1996, vol. 8, pp. 5887-5909 and the references cited therein. Amorphous polyester compounds are also commercially available, for example from Hüls AG, Mari, Germany, such as Dynapol S 1606, S 1611, S 1426, S 1427, S 1313, S 1421 and S 1420, Dynapol S 1313, S 1421 and S 1420 are preferred. The polyester component (i) of the pressure sensitive adhesive of the present invention may also comprise a small amount of crystalline polyester compounds. The pressure sensitive adhesive used for the preparation of the pressure sensitive adhesive tapes according to the invention further comprises an epoxy component (ii) containing one or more organic compounds having an oxirane ring polymerizable by ring opening . Such compounds, broadly called epoxides, include monomeric epoxy compounds and epoxides of the polymeric type and can be aliphatic, cycloaliphatic, aromatic or heterocyclic. The monomeric and the olimeric epoxy compounds preferably have two and more preferably 2 to 4 polymerizable epoxy groups per molecule. In epoxy resin or epoxy resin there may be many epoxy groups outstanding (for example a glycidyl methacrylate polymer could have several thousands of epoxy groups outstanding per average molecular weight). Oligomeric epoxides and in particular polymeric epoxy resins are preferred. The molecular weight of the epoxy-containing materials (ii) can vary from low molecular weight monomeric and oligomeric materials with a molecular weight for example of about 100 to polymeric resins with a molecular weight of about 50,000 or more and can vary widely in the nature of its fundamental chain and substituent groups. For example, the fundamental chain can be of any type and the substituent groups on it can be any group that does not have a nucleophilic or electrophilic group (such as an active hydrogen atom) that is reactive with an oxidant ring or that inhibits substantially the cationic polymerization. Illustrative of permissible substituent groups are halogens, ester groups, sulfonate groups, siloxane groups, nitro groups, amide groups, nitrile groups, phosphate groups, etc. Mixtures of various epoxy-containing compounds can also be used in the epoxy portion (ii) of the precursor of this invention. The epoxy component (ii) preferably comprises a mixture of two or more epoxy resins in order to modify and adapt the mechanical properties of the cured adhesive with respect to specific requirements. The term "epoxy resin" is used herein to denote any of dimeric, oligomeric or polymeric epoxy materials containing a plurality, that is, at least 2 of epoxy functional groups. Types of epoxy resins that can be used include, for example, the reaction product of bisphenol A and epichlorohydrin, the reaction product of phenol and formaldehyde (Novolac resin) and epichlorohydrin, perished epoxies, glycidyl esters, the reaction product of epichlorohydrin and p-amino phenol, the reaction product of epichlorohydrin and tetraphenol glyoxal and the like. Commercially available diglycidic esters of bisphenol-A are Araldite ™ 6010 from Ciba Geigy, DER ™ 331, from Dow Chemical and Epon ™ 825, 828, 826, 830, 834, 836, 1001, 1004, 1007, etc. of Shell Chemical. A Novolac phenol formaldehyde propolymer with polyepoxide function is available from Dow Chemical as DEN ™ 431 and 438 and from Ciba Geigy as CY-281 ™ and a Novolac prepolymer from cresol formaldehyde with polyepoxide function is available from Ciba Geigy as ECN ™ 1285, 1280 and 1299. A polyglycidyl ether of polyhydric alcohol is available from Ciba Geigy, based on butan-1,4-diol as Areldite ™ RD-2 and from Shell Chemical Corporation based on glycerin, such as Epon ™ 812 Suitable commercially available flexible epoxy resins include polyglycol diepoxies, DER ™ 732 and 736 from the Dow Chemical Company, diglycidyl ester of linoleic acid dimer, Epon ™ 871 and 872 from Shell Chemical Company, diglycidyl ester of a bisphenol in which the aromatic rings are bound by a long aliphatic chain, Lekutherm ™ X-80 from Mobay Chemical Company, synthetic rubber materials with epoxy function that are available from Shell Chemical Corporation and natural rubber materials with epoxy function such as ENR-10, ENR-25 and ENR-50 that are available from the Rubber Research Institute of Malaysia. The ENR materials are described in Encyclopedia of Polymer Science and Engineering, New York 1988, vol. 14, p. 769. The higher functional epoxy resins (this is a functionality greater than 2) that can be used include for example a solid epoxy Novolac resin, DEN ™ 485 from Dow Chamical Company, a solid tetrafunctional epoxy resin, Shell Epon ™ 1031 Chemical Company and N, N, N ', N'-tetraglycidyl-4,' -methylenebisbenzenamine, Araldite ™ MY 720 from Ciba Corporation. The difunctional epoxy resins which may be used include for example a solid resin, N, N, N ', N' -tetraglycidyl-a, A '-bis (4-aminophenyl) -p-diisopropyl benzene, HPT ™ 1071 from Shell Company , solid diglycidyl ether of bisphenol-9-fluorene, HPT ™ 1079 of Shell Chemical Company and para-aminophenol triglycidyl ether, Araldite ™ 0500/0510 of Ciba-Geigy Corporation. Useful cycloaliphatic epoxy resins include for example vinylcyclohexane dioxide which is commercially available as ERL-4206 from Union Carbide Corp., 3-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate available commercially as ERL-4221 from Union Carbide Corp. , 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexane carboxylate commercially available as ERL-4201 from Union Carbide Corp., bis (3, -epoxy-β-methylcyclohexylmethyl) adipate commercially available as ERL-4289 of Union Carbide Corp. or bis (2, 3-epoxycyclopentyl) ether commercially available as ERL-0400 from Union Carbide Corp. The pressure sensitive adhesive used for the preparation of pressure sensitive adhesive tapes in accordance with with the present invention further comprise as component (iv) a photoinitiating component comprising an effective amount of one or more photoinitiating compounds. The photopolymerization can be carried out at room temperature at a lower temperature but can also be carried out at higher temperatures which are preferably lower than the melting temperature of the pressure-sensitive adhesive tape in order to accelerate the reaction of reticulation. The photopolymerization is preferably carried out as cationic polymerization and the photoinitiators are preferably selected from a group consisting of metallocene salts and aromatic onium salts. Suitable salts of organometallic complex cations (or metallocene salts) include but are not limited to those salts having the following formula (I) [(L1XL2) Mp] qYn (I) wherein: Mp represents a metal ion selected from the group consisting of Cr, Mo,, Mn Re, Fe and Co, p denotes the charge of the metal ion; L "1 represents 1 or 2 ligands that contribute pi-electrons which may be the same ligand or a different ligand selected from the group of: 3-allyl, 5-cyclopentadimyl and 7-cycloheptatrylin, substituted or unsubstituted and 6-aromatic compounds selected from 6-benzene compounds and substituted 6-benzene compounds having 2 to 4 fused rings, each capable of contributing 3 to 8 pi-electrons to the valence envelope of Mp; L2 represents zero or 1 to 3 ligands that contribute an even number of sigma-electrons that can be the same ligand or a different ligand selected from the group of: carbon monoxide, nitrosonium, triphenyl phosphine, triphenyl stiline and phosphorus, arsenic and antimony derivatives , with the proviso that the total electronic load contributed to Mp results in a net positive residual charge of q to the complex; q is an integer that has a value of 1 or 2, the residual charge of the complex cation; Y is a halogen-containing complex anion selected from BF ", AsF6", PF6", SbF5OH", SbF6"and CF3S03"; and n is an integer having a value of 1 and 2, the number of complex anions required to nuetralize the charge q on the complex cation. Preferred examples of suitable salts of the organometallic complex which are cations useful in the pressure sensitive adhesive tape of the invention include the following: (? 6-benzene) (? 5-cyclopen-tadienyl) iron (+) hexafluoroantimonate; hexafluoroarsenate of (? 6-toluene) (? 5-cyclopenta-dienyl) iron (1+); hexafluorofluorophosphate (? 6-cumen) (? 5-cyclopen-thienyl) iron (1+); hexafluoroantimonate of (? 6-p-xylene) (? 5-cyclopen-thienyl) iron (1+); hexafluorophosphate of (? 6-xylenes) (mixed isomers) (? 5- cyclopentadienyl) iron (1+); triflute of (? 6-o-xylene) (? 5-cyclopentadienyl) iron (1+; (? 6-m-xylene) (? 5-cyclopentadienyl) iron tetraf luoroborate (1+); hexafluoroantimonate of (? 6-mesitylene) (rp-cyclopentadienyl) iron (1+); (? -hexamethyl-benzene) (? -cyclopentadienyl) iron pentafluorohydroxyantimonate (1-); (? 6-naphthalene) (? 5-cyclopen-thadienyl) iron tetrafluoroborate (1+); (? 6-pyrene) (? 5-cyclopentadienyl) iron triflate (1+); hexafluoroantimonate (6-toluene) (5-cyclopen-thienyl) iron (1+); hexafluoroantimonate of (? 6-cumen) (? 5-cyclopen-thienyl) iron (1+); hexafluoroantimonate of (? 6-p-xylene) (? 5-cyclo-pentadienyl) iron (1+); hexafluoroantimonate of (? 6-m-xylene) (? 5-cyclo-pentadienyl) iron (1+); hexafluoroantimonate of (? 6-hexamethylbenzene) (? 5-cyclopentadienyl) iron (1+); hexafluoroantimonate of (? 6-naphthalene) (? 5-cyclo-pentadienyl) iron (1+); (? 6-pyrene) (? 5-cyclo-pentadienyl) iron hexafluoroantimonate (1+); hexafluoroantimonate of (? € - acrylene) (? 5-cyclo-pentadienyl) iron (1+); hexafluoroantimonate of (? 6-perilylen) (? 5-cyclo-pentadienyl) iron (1+); pentafluorohydroxyantimonate of (β-acrylene) (rp-cyclopentadienyl) iron (1+); hexafluoroantimonate ((6-acetophenone) (rp-methyl-cyclopentadienyl) iron (1+); (? 6-Fluorine) (? 5-cyclo-pentadienyl) iron hexafluoroantimonate (1+). The metallocene salts of formula I and their preparation are described, for example, in U.S. Patent No. 5,089,536, U.S. Patent No. 5,059,701, and European Patent Publication No. 0,109,851. The metallocene salts can be used in conjunction with a reaction accelerator such as an oxalate ester of a tertiary alcohol. Also preferred are the aromatic onium salts which are described for example in U.S. Patent Nos. 4,069,054, 4,231,951 and 4,250,203. Such salts can be described by the formula: AX (II) wherein A is an organic cation selected from those described in U.S. Patent Nos. 3,708,296, 3,729,313, 3,741,769, 3,794,576, 3,808,006, 4,026,705, 4,058,401, 4,069,055, 4,101,513, 4,216,288, 4,394,403 and 4,623,676, all incorporated herein by reference and X is an anion wherein X is defined as Y in formula (I) above. A is preferably selected from diazonium, iodonium and sulfonium cations and more preferably from diphenyliodonium, triphenylsulfonium and phenylthiophenyl diphenylsulfonium. X is preferably selected from the group of anions consisting of CF3S03 ~, BF ", PF6 ~, SbF6 ~, SbF60H", AsF6 ~ and? BCl6 ~. Aromatic iodonium salts and aromatic sulfonium salts are preferred. Particularly preferred aromatic iodonium and aromatic sulfonium salts are described in the publication of "European Patent No. 0,620,259, p. 5 line 17 to page 6, line 29. Useful commercially available cationic photoinitiators include UVOX UVI-6974, a complex salt of aromatic sulfonium (Union Carbide Corp.) and IRGACURE 261, a complex salt of metallocene (Ciba-Geigy). The pressure sensitive adhesives which are useful for the preparation of the pressure sensitive adhesive tapes according to the invention optionally comprise a hydroxyl-functional component (iii) containing one or more hydroxyl-containing compounds having a hydroxyl functionality of at least 1 and more preferably at least 2. The hydroxyl-containing compounds should be substantially free of other groups containing "active hydrogen" such as amino and mercapto portions. The hydroxyl-containing compounds must also be substantially free of groups that can be thermally and / or photolytically unstable such that the compounds will not decompose or release volatile components when exposed to electron radiation or actinic radiation and optionally to heat during the cured. Preferably, the compounds contain two or more primary or secondary aliphatic hydroxyl groups (that is, the hydroxyl group is directly linked to a non-aromatic carbon atom). The hydroxyl group may be terminally located or may be pendent for a polymer or copolymer. The average equivalent weight number of the hydroxyl-containing material is preferably from about 31 to 2500, more preferably about 80 to 1000 and more preferably about 80 to 350. The hydroxyl number can be described by the equation: 56. 1 x 1000 x f OH = P.M. wherein OH = hydroxyl number of the hydroxyl compound of the hydroxyl functional compound; f = fucionality, that is, average of hydroxyl groups per molecule of the hydroxyl functional compound and P.M. = molecular weight of the hydroxyl functional compound (average in number). Illustrative examples of hydroxyl-containing materials include monomeric and polymeric compounds. The monomeric hydroxyl functional compounds comprise, for example, ethylene glycol, propylene glycol, 1,3-dihydroxypropane, 1,3-dihydroxybutane, 1,4-dihydroxybutane, 1,4-, 1,5- and 1,6-dihydroxyhexane, 1,2 -, 1,3-, 1,4-, 1,6- and 1,8-dihydroxyoctane, 1,1-dihydroxyhexane, 1,1-trimethylol-ethane, 1,1-trimethylolpropane, pentaerythritol, polycapro -lactone, xylitol, arabitol, sorbitol or mannitol. Suitable examples of polymeric hydroxyl functional compounds comprise, for example, polyoxyalkylene polyols (for example, polyoxyethylene and polyoxypropylene glycols and triols of equivalent weight of 31 to 2500 for diols or 80 to 350 for triols), polytetramethylene oxide glycols of variable molecular weight, hydroxyl-terminated polyesters and hydroxyl-terminated polyacetones. Useful commercially available hydroxyl containing materials include the POLYMEG series (available from QO Chemicals, Inc.) of polytetramethylene oxide glycols such as POLIMEG 650, 1000 and 2000; the TERATHANE series (from E.I. duPont de Nemours and Conpany) of polytetramethylene oxide glycols such as TERATHANE 650, 1000 and 2000; POLYTHF, a polytetramethylene oxide glycol from BASF Corp .; BUTVAR series (available from Monsanto Chemical Company) of polyvinylacetal resins such as BUTVAR B-72A, B-73, B-76, B-90 and B-98; the TONE series (available from Union Carbide) of polycaprolactone polyols such as TONE 0200, 0210, 0230, 0240 and 0260; the DESMOPHEN series (available from Miles Inc.) of saturated polyester polyols such as DESMOPHEN 2000, 2500, 2501, 2001KS, 2502, 2505, 1700, 1800 and 2504; the RUCOFLEX series (available from Ruco Corp.) of saturated polyester polyols such as S-107, S-109, S-1011 and S-1014; VORANOL 234-630 (a trimethylol propane) from Dow Chemical Company; VORANOL 230-238 (an adduct of glycerol oxide of polypropylene) from Dow Chemical Company; the SYNFAC series (from Milliken Chemical) of polyoxyalkylated bisphenol A 'such as SYNFAC 8009, 773240, 8024, 8027, 8026 and 8031; the ARCOL series (from Arco Chemical Co.) of polyoxypropylene polyols such as ARCOL 425, 1025, 2025, 42, 112, 168 and 240; and the SIMULSOL series (from Seppic, Paris, France) of bisphenol-A extended polyols such as SIMULSOL BPHE, BPIE, BPJE, BPLE, BPNE, BPRE, BPHP, BPIP, BPRP and BPUP.

The amount of the polyester component (i) with respect to the total mass of the components (i) - (iv) is between 30% by weight - 80% by weight and preferably between 35% by weight and 55% by weight. weight. The polyester component comprises one or more polyester compounds and in particular 1-4 polyester compounds, at least one of them consisting of an amorphous polyester compound. Polyester components that only comprise amorphous polyester compounds are preferred. The amount of the epoxy component (ii) with respect to the total mass of the components (i) - (iv) is between 20% by weight to 70% by weight. The epoxy component comprises at least one epoxy resin or epoxy monomer, preferably 1-4 and more preferably 1-3 epoxy resins and / or monomers. The epoxy compounds may be liquid or solid at room temperature under normal conditions. It was found that the softness of the pressure sensitive adhesive at room temperature can be varied by varying the vitreous transition temperature of the polyester component (i) and the ratio of the liquid and solid epoxy compounds. In the case that the polyester component comprises more than one polyester compound, the vitreous transition temperature Tg can be estimated well by using the Fox equation where Tg, n is the glass transition temperature and Xn is the mole fraction, respectively of the n-th polyester compound. A complete description of the calculations of Tg based on the Fox equation can be found in Makromolekuele, 5th ed. by Hans-Georg Elias (Huethig & epf, 1990), p.856. In the case where the vitreous transition temperature of the polyester component (i) is less than 0 ° C, the mt / ms ratio of the sum of the masses of the liquid epoxy compounds and the liquid hydroxyl functional compounds with respect to the sum of the masses of the solid epoxy compounds and the solid hydroxyl functional compounds is preferably not more than 1.2 and especially preferably less than 0.50. In the case where the vitreous transition temperature of the polyester component is greater than 0 ° C and in particular greater than 10 ° C, the proportion of the masses of the liquid epoxy compounds and the liquid hydroxyl functional compounds with respect to the masses of the solid epoxy compounds and the solid hydroxyl functional compounds is preferably greater than 0.5, more preferably greater than 1 and more preferably greater than 2. It was also found that the adhesion to 90 ° release of the pressure sensitive adhesive on Stainless steel can be modified and adapted to specific needs by varying the ratio of mt / ms for a given Tg of the polyester component. Adhesion to the initial release on stainless steel, as measured 20 minutes after the application of the pressure-sensitive adhesive tape, can usually be increased in the case that the vitreous transition temperature of the polyester component is less than 0 °. C by decreasing the previous ratio rri? / Ms as long as the phase separation of the pressure sensitive adhesive is avoided. In the event that the vitreous transition temperature of the polyester component is greater than 0 ° C, the adhesion to the initial release can also be increased in general by decreasing the above proportion mt / ms as long as mt / ms is greater than 1 , whereas when the proportion of mI / m is decreased? in the area of m? / m? = 1, an increase in the addition to the release is usually observed. The amount of the optional functional hydroxyl component (iii) with respect to the total mass of the components (i) - (iv) is between 0-50% by weight and preferably between 5-35% by weight. The functional hydroxyl component, if present, preferably comprises 1-3 and more preferably 1 or 2 compounds. The hydroxyl functional compounds may be liquid or solid at room temperature under normal conditions but are preferably liquid. The amount of the functional hydroxyl component is preferably described in such a way that the combined mass of the epoxy component (ii) and the functional hydroxyl component (iii) with respect to the total mass of the components (i) - (v) is III S n = ?? ? »0.2 < < 0.7 «=] where mn is the mass of the nth compound and n is i, ii, iii and iv. This proportion is more preferably between 0.3 and 0.55. It was also found that the proportion of m (Xi) + (lii) /? Ri (i) of the sum of the masses of the liquid and solid epoxy compounds and the liquid and solid hydroxyl functional compounds with respect to the mass of the Polyester compounds are preferably less than 1.7, more preferably less than 1.6 and in particular less than 1.55. If the above ratio is more than 1.75 and in particular at least 1.8, the elasticity of the crosslinkable pressure-sensitive adhesive tape is insufficient and the holding power tends to be less than 5 minutes. The vitreous transition temperature of the pressure sensitive adhesive as measured by the peak or maximum in the delta tangent curve of 1 Hz when the sample is cooled to a temperature of about 50 ° C greater than its glass transition temperature Tg a a temperature of about 50 ° C lower than its vitreous transition temperature Tg at a rate of 2 ° C / minute when using a Rheometrics RDA II apparatus in the parallel plate cutting voltage mode, is preferably between -15 ° C and 30 ° C, more preferably between 0 ° C and 25 ° C. The glass transition temperature Tg of the pressure sensitive adhesive can be modified by controlling the Tg of the polyester compound (s) and / or the above ratio mt./ms. By increasing the amount of (the) polyester compound (s) with a lower value of Tg tends to decrease the Tg value of the pressure sensitive adhesive. The increase in the mt / ms ratio results in the decrease of the Tg of the pressure sensitive adhesive while the decrease in the mt / ms ratio tends to raise the Tg of the pressure sensitive adhesive. It is preferred that the pressure sensitive adhesive does not exhibit macroscopic phase separation. Macroscopic phase separation means that the components of the pressure-sensitive adhesive tape migrate to the release liner or liner that protects the exposed adhesive surfaces and results in easily visible haze on the internal release liner after it is separated from the ribbon Pressure sensitive adhesive. The amount of the photoinitiator component (iv) with respect to the total mass of the components (i) - (iv) is preferably between 0.01-5% by weight and more preferably between 0.1-2% by weight. The photoinitiator component preferably comprises 1-3 and more preferably 1 photoinitiator compound. The mass percentages given for components (i) - (iv) of the pressure sensitive adhesive are added to 100% by weight. The pressure sensitive adhesive may additionally comprise various fillers, adjuvants, additives and the like such as silica, glass, clay, talc, pigments, dyes, glass beads or bubbles, glass or ceramic fibers, antioxidants, flame retardants and the like to reduce the cost or weight of the composition, adjust the viscosity and provide additional reinforcement. Fillers and the like that are capable of absorbing the radiation used during the curing process must be used in an amount that does not adversely affect the curing process. The amount of such additives can be between 0-50% by weight and more preferably 1-05% by weight with respect to the total mass of the components (i) - (iv).

The pressure sensitive adhesive useful for the preparation of the pressure-sensitive adhesive tapes of the present invention exhibits a holding power value, as measured in accordance with the modified version of PSTC-14 described in the test section. subsequently in the present, of at least 5 minutes, preferably of at least 10 minutes and more preferably of at least 20 minutes, which allow the preparation of the pressure-sensitive adhesive tapes with temperature handling properties improved environment. Adhesive pressure-sensitive adhesive tapes of the present invention with a thickness of for example 200 μm exhibit a certain elasticity and an elongation to the coating normally between 200% or more. The pressure sensitive adhesive used for the preparation of the pressure-sensitive adhesive tapes of the present invention exhibits a peel adhesion at 90 ° at room temperature on stainless steel 20 minutes after the application of at least 2N / 1.27 cm (0.5 inches), preferably at least 4N / 1.27 cm (0.5 inches), more preferably at least 6N / 1.27 cm (0.5 inches) and especially preferably at least 7.5N / 1.27 cm (0.5 inches). Adhesion to detachment can be modified and optimized with respect to a specific application by varying: the vitreous transition temperature of the amorphous polyester component (i), - the proportion of the liquid epoxy / solid epoxy compounds, - the amount of the optional functional hydroxyl component (iii) and / or - the ratio of the liquid / solid functional hydroxyl compounds, - the molecular weight of the components, as discussed above, without adversely affecting the mechanical integrity and manageability required at room temperature. pressure sensitive adhesive tape. The pressure sensitive adhesive tapes according to the present invention can be unsupported or supported. The unsupported pressure sensitive adhesive tapes that do not comprise any support (also referred to as transfer tapes) can be obtained for example, by mixing components (i) - (iii) and if fillers, adjuvants or other additional additives are present. in a suitable glass vessel at elevated temperatures sufficient to make the mixture liquid. Then the mixture is homogenized with a stirrer and the photoinitiator component (iv) is added. Then the resulting mixture is coated to the desired thickness on a first internal release liner such as a siliconized polyester film and a second internal liner is subsequently laminated on the exposed surface of the unsupported pressure sensitive adhesive tape. The addition of the photoinitiator component (iv) briefly before coating prevents or minimizes the degradation of the photoinitiator compounds and / or premature cationic polymerization. The method of preparing the unsupported pressure sensitive adhesive tapes summarized above illustrates the invention only without limiting it. Other methods can be used such as for example extrusion of unsupported adhesive tape according to support which can be for example an internal release coating. The supported pressure sensitive adhesive tapes comprise at least one support. Depending on the respective application, the support can be selected from a group of materials comprising polymer films of various stiffnesses, such as for example polyolefins, polyesters, polycarbonates or polymethacrylates, papers, nonwovens, metal fasteners of a part (which they are described for example in U.S. Patent 5,077,870) or metals. The thickness of the support commonly varies between 25μm and 3000μm, preferably between 25 and lOOOμm. The support material must be selected in such a way that the layers of the additive stick very strongly to it. Such a choice can be made easily and does not require any inventive effort of the expert. If desired, the support can be treated with chemical primers or primers or can be treated by corona. The pressure sensitive adhesive can be applied to the support by coating the molten mixture comprising the components (i) (iv) and if fillers, adjuvants or other additional additives are present. Due to its advantageous values of cohesion strength and retention power, the pressure sensitive adhesive used in the present invention allows the preparation of unsupported pressure sensitive adhesive tapes. The unsupported pressure sensitive adhesive tapes can be used for example to mount two substrates. The adhesive tape can be cut or punched to the desired symmetrical shape and applied to the first substrate at room temperature using finger pressure or an appropriate pressure transfer device. The curing reaction can be initiated for example by exposing the pressure-sensitive adhesive tape to actinic radiation (ie,, radiation having a spectrum in the UV or VIS spectral regions that overlap at least partially with the absorbance spectrum of the photoinitiating compounds) or electron radiation. Preferably, the energy is actinic radiation having a wavelength in the ultraviolet or visible spectral regions. Appropriate sources of actinic radiation include mixtures of mercury, xenon, carbon arc, tungsten filament lamps, sunlight, etc. Ultraviolet radiation, especially of a medium pressure mercury arc lamp, is especially preferred. Preferred radiation sources have an essential part of their spectral output in the wavelength range of 200-600 nm, more preferably 250-450 nm and more preferably 300-450 nm. The types of exposure can be less than about 1 second to 10 minutes or more (to provide a total energy exposure of usually between 25 and 2000 mJ / cm2 of UV-A energy measured by an appropriate photodetection device such as those obtained of EIT (Sterling, Virginia) and calibrated in accordance with NIST standards (National Institute of Standards and Technology) depending on the quantity and type of reagents involved, the energy source, the distance of the energy source, the thickness of the adhesive tape and the type of handling after the desired curing.

Adhesive pressure sensitive tapes must also be cured by exposure to electron beam radiation (e-beam). The necessary dosage is generally less than 1 megarad to 100 megarads or more. The curing speed tends to increase with the increased amounts of initiator at a given energy exposure. The curing speed also increases with the increased energy intensity. Subsequent to the initiation of the cationic curing reaction the second substrate is adhered to the pressure sensitive adhesive tapes by using pressure in the course of the handling time after curing. The handling time after curing gives the time during which the respective substrate can be reliably adhered to the adhesive surface sensitive to the curing pressure of the adhesive tape. With the increased crosslinking density of the pressure sensitive adhesive, the wetting properties of the adhesive tape with respect to the surface decrease and the desired mechanical properties of the assembly such as high values of cut resistance of overlap and / or impact resistance and they can not be obtained. The handling time after curing depends on the properties of the pressure sensitive adhesive used, the desis and irradiation geometry, the thickness of the pressure-sensitive adhesive tape, the substrates and the desired properties of the assembly. The handling time after curing can vary from 1 second to 2 hours and is preferably between 2 and 15 minutes and more preferably between 2 and 5 minutes. The unsupported pressure-sensitive adhesive tape can also be subjected to actinic radiation and / or electron beam radiation before being mounted to the substrates to thereby initiate the cationic curing reaction before assembly. The actinic and / or electron beam radiation can be applied to one or both sides of the pressure-sensitive adhesive tape. The activation of both sides of the pressure-sensitive adhesive tape results in more homogeneously cured pressure-sensitive adhesive tapes and is preferred. In the case that at least one of the substrates is transparent, for example to UV radiation, curing can also be initiated after adhering the substrates to the pressure-sensitive adhesive tape by emitting ultraviolet light through the transparent substrate. in ultraviolet light. If overexposure to ultraviolet light is only on one side of the tape, it is preferred that the UV source have a substantial UV emission between 300 and 400 nm to ensure the best uniform curing.

The pressure sensitive adhesive tape according to the invention can be used to glue a wide variety of substrates which can be selected from a group of materials consisting of glass, plastics, metals, ceramics and materials derived therefrom, such as by example ceramic coated glass. Depending on the substrates chosen, the mechanical properties of the cured assembly can sometimes be improved by heating one or both of the substrates and / or the pressure sensitive adhesive tape after it is applied to the substrate or substrates respectively. The applicable temperatures are preferably between 40 and 140 ° C and more preferably between 80 and 120 ° C. Although it is not desired to be limited by such a theory, it is speculated that due to the high temperature the wetting properties of the pressure-sensitive adhesive tape at the interface surface of the substrate / surface of the adhesive tape are improved, which results in a increased adhesion between the substrate and the tape. The heat applied to the belt or substrate is preferably kept low enough to facilitate surface wetting while preventing the entire pressure-sensitive adhesive tape from melting and becoming liquid. The heat applied to the pressure-sensitive adhesive tape after it has been activated, increases the speed of the epoxy curing reaction. The heat treatment can be applied to one or both respectively of the substrate / tape interfaces and it is also possible to maintain the assembly at an elevated temperature during the curing reaction in order to decrease the curing time. Mounts according to the present invention are characterized by advantageous mechanical properties and in particular by high values of cut resistance of overlap and / or impact resistance, as measured according to the test methods specified hereinafter. The assemblies of the present invention exhibit a shear strength of at least one overlap. 4 MPa, more preferably of at least 6 MPa and in particular of at least 8 MPa are preferred. The impact strength is preferably at least 3 KJ / m2 and more preferably at least 6 KJ / m2 and more preferably at least 9 KJ / m2. The pressure-sensitive adhesive tapes of the present invention are useful for various applications such as for example bonding applications in the automotive, construction or electronics industries. In a specific application an unsupported pressure sensitive adhesive tape of the present invention is used to adhere means of attachment to a windshield that allows for easy adjustment of the windshield when mounted thereto to the vehicle body. The attachment means may comprise for example a pin, fastener, strip or other fastener that is securely secured or adhered to the windshield when using an unsupported or supported pressure sensitive adhesive tape of the present invention. The other end of the joining means is placed at predetermined points of the vehicle body. In a specific embodiment, the other end of the attachment means can pass through a hole in the vehicle body where it is mechanically fastened, for example by applying a nut to the attachment means or can be retained in its place by gravity and friction. Specific geometries of the joining means can be taken for example from U.S. Patent 5,475,956. The joining means may comprise various materials such as for example metals such as brass, bronze, aluminum or steel and plastics such as PMMA (polymethylmethacrylate), polystyrene, polyamide, polycarbonate, polyester or other rigid and moderately polar plastics. In a particularly preferred embodiment, the joining means consist of an injection molded bolt having a base element of approximately 2-3 cm in diameter and a positioning element formed cylindrically of 2-3 com in length and 0.05 - 1 cm in diameter, which is perpendicular to the base. The pin is preferably manufactured from PMMA or from polyamide. A pressure-sensitive adhesive tape which can be crosslinked by UV light, which is preferably not supported, is unrolled from a roll, preferably in the form of dies and subjected to ultraviolet radiation. The first release liner or liner is removed and the activated pressure-sensitive adhesive tape is bonded to the back surface of the bolt. After removal of the second internal release liner, the bolt is attached to a predetermined position on the windshield, preferably to an area with a ceramic coating that has been preheated, for example with an IR heater, at a surface temperature of at least 60 ° C and preferably at least 100 ° C. It has been found that by subjecting the bonding means with the cured pressure sensitive adhesive after the windshield had been mounted on the vehicle body to a qualitative impact test (hammering on the windshield) this resulted in the breaking of the windshield instead of any failure of the union between the windshield and the bolt. The pressure-sensitive adhesive tape can also be used to adhere corbels or oven brackets, for structural elements or architectural configurations or for joining or bonding integrated circuit chips in the electronics industry. The invention is further illustrated by the following non-limiting examples. First, however, certain procedures and tests used in the examples will be described.

Test methods for uncured pressure sensitive adhesive tapes Adhesion of 90 ° release The 90 ° release adhesive was determined by using PSTC-2, a procedure specified in "Test Methods for Pressure Sensitive Adhesive Tapes" 12th edition, available from Pressure-Sensitive Adhesive Tape Council, 401 North Michigan Avenue, Chicago, IL 60611-4267, United States of America. A 1.27 cm x 8 cm strip of an unsupported pressure sensitive adhesive tape (200 μm thick) between two release layers was prepared as described in Example 1 and allowed to age for at least 24 hours before the tests. An internal release liner was removed and the exposed material was manually pressed on the obtuse side of a 125 μm thick sheet of anodized aluminum that serves as a support for the tape construction. The anodized aluminum sheet was 1.6 cm wide. The second internal release liner was removed from the exposed surface adhered to a stainless steel test panel that had previously been cleaned with methyl ethyl ketone and heptane. The construction thus prepared was configured in such a way that the anodized aluminum sheet had a non-glued adhesive-free tongue of approximately 10 cm for attachment to a tensile tester. The stuck construction was then passed twice with a 6.8 Kg roller and allowed to remain in contact with the test substrate for approximately 20 minutes before testing. The test construction thus obtained was then placed in a tensile tester (Instron ™) in such a way that the aluminum sheet was detached from the stainless steel test panel at a 90 degree angle. Adhesion to detachment was measured at a speed of 30.5 cm per minute and was recorded at N / 1.27 cm. The test was repeated 2 times and then the results were averaged.

Retention power A modified version of the PSTC-14 standard was applied, a procedure specified in "Test Methods for Pressure Sensitive Adhesive Tapes" 12th edition, available from Pressure-Sensitive Adhesive Tape Council, 401 North Michigan Avenue, Chicago, IL 60611-4267 , United States of America . An unsupported pressure sensitive adhesive tape having a thickness of approximately 200 microns, sandwiched between two silicone PET release liners was cut into a strip 1.27 cm wide and 8 cm long. An internmo release liner was removed from the face of the exposed adhesive bonded to an anodized aluminum liner 125 microns thick, 1.6 cm wide and approximately 10 cm long such that an area of 2 cm on the end of the Aluminum strip was not coated with the adhesive. The second internal release liner was removed and the entire exposed adhesive face adhered to a rigid aluminum plate that had been cleaned twice with heptane. Then, the newly formed assembly is passed four times with a 2Kg roller. After a one-minute residence time, the assembly was suspended perpendicular to the direction of the gravitational force by attaching one end of the rigid aluminum plate to a vertical pedestal such that the rigid aluminum substrate was on top and the flexible aluminum coating was suspended therefrom. Then a weight of 150 g was attached to the opposite end of the aluminum coating that was not glued to the aluminum plate. The time rred for tape gluing to fail as measured by the weight drop is recorded in minutes.

Static cut This test is based on the PSTC-7 PSTC method (procedure A), a procedure specified in "Test Methods for Pressure Sensitive Adhesive Tapes" 12th edition available from Pressure-Sensitive Tape Council, 401 North Michigan Avenue, Chicago, IL 60611-4267, United States of America. All measurements of this type were made at room temperature. An unsupported pressure-sensitive adhesive tape having a thickness of approximately 200 μm, sandwiched between two internal release liners, was obtained as described in Example 1. An internal release liner was separated and replaced by a layer of 125 μm thickness of anodized aluminum sheet. Then the second internal release liner was removed, to produce an adhesive tape with an aluminum support that was used in the static cut test. A 1.27 cm wide strip of tape prepared by the method described above was adhered to a flat, rigid stainless steel plate with 2.54 cm length of tape in contact with the panel. Then the total glued area was 1.27 cm x 2.54 cm. Then the panel with the adhered tape test sample was placed on a special support tilted 2 degrees from the vertical for 10 minutes. Then a weight of 50 g was hung from the free end of the tape. The time required for the weight to fall is the value in the static cut in hours.

Test methods for cured pressure-sensitive adhesive tapes Impact resistance A modified version of ISO 9653 was applied. The modification consisted of changes in the sample assembly configuration and the glued area. An adapted layer was integrated in such a way that the sides of the metal test plates could be mechanically retained in the area of the stage and smaller test bodies adhered thereto. The configuration of the glued mount used to perform the test measurements consisted of an aluminum test body having the dimensions of 15 mm x mm x 5 mm adhered to an aluminum test plate having the dimensions of 2.54 cm x 10 cm x 2 mm. The test body was placed in relation to the test plate in such a way that the 10 cm side of the test body was parallel to a line that differed from the minimum point of the oscillation of the pendulum. The area stuck was 1.27 cm x 2 cm. The aluminum test plate and the aluminum test body were cleaned by light abrasion with a scouring pad Scotchbrite ™ with water and then washed with MEK (methyl ethyl ketone), then isopropanol followed by a final rinse with MEK (methyl ethyl ketone) ). Then the aluminum weights are allowed to dry in air before the test assembly is prepared. An unsensitive pressure-sensitive adhesive tape of 250 microns thick that was prepared as described in Example 1 and allowed to age for at least 24 hours before testing. A sample having dimensions of 1.27 cm x 2.0 cm is cut. An internal coating was removed and the exposed pressure sensitive adhesive was irradiated with 200 mJ / cm2 of an ultraviolet light bulb (H-bulb available from Fusion Systems Corporation, Rockville, Maryland, United States of America) contained in a source of high density ultraviolet light also commercially available from Fusion Systems Corporation. The amount of energy used to irradiate the adhesive face was measured by using a UVI MAP (TM) UV temperature measurement / graphing system, model UM365H-S (Electronic Instrumentation Technology Inc., Starling, Virginia, United States of America) designed to measure UV-A radiation in the range of 320-390 nm. The device was calibrated according to the standards of N.I.S.T. (National Institute of Standards and Technology). Then the irradiated pressure sensitive adhesive was adhered to the aluminum test body in such a way that the 1.27 cm width of the adhesive strip was centered and parallel to the 20 mm edge of the test body. Then the second inner liner was removed from the adhesive and irradiated in the same manner as described above. Then the exposed adhesive was adhered to the test plate, to glue the test body and the test plate together. Then the attached assembly was held together with pliers, a moderate manual pressure is used for about a second. The glued sample assembly is allowed to cure or solidify at a temperature of 23 ° C to 50% relative humidity for 3 days before testing. A commercially available impact tester is used as model 5102 from Zwick GmbH, Ulm, Germany. A pendulum of 4 Joules was used, corresponding to a weight of 934.6 g at a speed of 2.93 m / second. This speed was generated by lifting the pendulum to the full extent of 160 ° at an arm length of 225 mm before the weight is released and allowed to strike the assembly or sample assembly in a shear mode described in ISO 9653 and designed to cut the test body of the test plate. The amount of energy absorbed by the sample set as the pendulum breaks the adhesive bond was measured by reading the height of the pendulum swing and recorded in Joules. The test was carried out in each of three separate assemblies and the results were averaged.

Superposition cut A modified version of ISO 4587 was used. Aluminum coupons (100 mm x 25 mm 2 mm) were subjected to a light abrasion treatment with a Scotchbrite ™ cleaning pad (available from 3M Company) followed by soap / water and finally cleaned with isopropanol. The assemblies or assemblies were prepared by removing one of the two protective inner liners and a pressure-sensitive adhesive strip (1.27 cm x 2.54 cm) as generated in the examples, irradiating the exposed adhesive surface in the manner described in FIG. the test section for the previous impact resistance, except that the pressure-sensitive adhesive tape was irradiated with 400 mJ / cm2 from both sides and then glued from the irradiated adhesive to the aluminum coupon. The second protective inner liner was removed and the second surface of the adhesive also irradiated in the same manner. Finally, the second surface of the adhesive tape was glued to the second aluminum coupon in a configuration described in the standard method. The adhesive was aligned with the longer side perpendicular to the direction of the force applied during the test and was always placed in such a way that it was level with the end of the coupon stuck. The glued assemblies were held together with pliers by using moderate manual pressure for approximately one second and are allowed to cure at a temperature of 23 ° C and 50% relative humidity for at least 3 days before testing. The dynamic superposition cut test was carried out on assemblies or assemblies comprising the Al coupon / adhesive / coupon sequence prepared as described above. The test method deviated from the standard test method specified above in that the transverse velocity was 5 mm / minute. The test was repeated three times for each sample and the average value was recorded in MPa.

Materials used in the examples DYNAPOL S 1313 polyester compounds, amorphous copolyester, Tg = 13 ° C, softening point or temperature Ts = 100 ° C, commercially available from Hüls AG, Mari, Germany. DYNAPOL S 1421, amorphous copolyester Tg = -4 ° C, Ts = 80 ° C, commercially available from Hüls AG, Mari, Germany DYNAPOL S 1402, slightly crystalline copolyester, Tg = -12 ° C, melting point Tm = 92 ° C, commercially available from Hüls AG, Mari, Germany DYNAPOL S 1359, slightly crystalline copolyester, Tg = -16 ° C, Tm = 100 ° C, commercially available from Hüls AG, Mari, Germany DYNAPOL S 1227, moderately crystalline copolyester, Tg = 13 ° C, Tm = 118 ° C, commercially available from Hüls AG, Mari, Germany DYNAPOL S 1228, moderately crystalline polyester, Tg = -3 ° C, Tm = 110 ° C, commercially available from Hüls AG, Mari, Germany .

DER 331 epoxy resins, epoxy equivalent weight of about 187, liquid at room temperature and atmospheric pressure, commercially available from Dow Chemical Comp., Midland, MI. EPON 1001, epoxy equivalent in weight of about 515, solid at room temperature and atmospheric pressure, commercially available from Shell Chemical.

Functional hydroxyl compounds VORANOL 230-238, adduct of glycol polyol and propylene oxide having a hydroxyl number of 38, molecular weight (number average) of 700, liquid at room temperature and atmospheric pressure, commercially available from Dow Chemical, Midland, MI (referred to in the tables below as V 230-238). SIMULSOL BPHE, a difunctional bisphenol A based polyol, liquid at room temperature and atmospheric pressure, molecular weight (number average) of 315, commercially available from Seppic, Paris, France (hereinafter referred to as BPHE). SIMULSOL BPRE, a difunctional bisphenol A based polyol, liquid at room temperature and atmospheric pressure, molecular weight (number average) of 755, commercially available from Seppic, Paris, France (hereinafter referred to as BPRE). TONE 0305, a tri-functional polycaprolactam-based polyol, liquid at room temperature and atmospheric pressure, molecular weight (number average) of 540, commercially available from Union Carbide (hereinafter referred to as T 0305) TERETHANE 1000, a polyol a base of difunctional poly THF, liquid at room temperature and atmospheric pressure, molecular weight (number average) of 1000, commercially available from DuPont (hereinafter referred to as T 1000).

UVOX cationic photoinitiator UVI 6974, triarylsulfonium complex salt, commercially available from Union Carbide, Danbury, CT.

Examples Examples 1-12 The polyester component (i), the epoxy component (ii) and the hydroxyfunctional component (iii) as specified in table 1 were combined in a closed glass vessel and placed in a forced air oven for 2 hours at 150 ° C. The resulting mixture was stirred until a homogeneous mixture was obtained. The photoinitiator component (iv) as specified in table 1 was then added and the mixture was again stirred until the photoinitiator dissolved. Then the resulting liquid mixture was poured between two siliconized internal PET release liners or liners previously threaded in a heated knife coating apparatus. The heated knife coater had a bed temperature of 100 ° C and the blade was preheated in an oven at 120 ° C before coating. The coating by heated blades results in an unsupported pressure sensitive adhesive tape with a thickness of approximately 200 μm between the internal PET release liners. The unsupported pressure sensitive adhesive tapes were tested according to the test methods specified above and the results obtained are summarized in Table 2.

Comparative Example 1 An unsupported pressure sensitive adhesive film having the composition specified in the table 1 was prepared according to the method of example 1.

Although comprising the amorphous polyester DYNAPOL S 1421, the unsupported pressure sensitive adhesive film exhibits a holding power of virtually 0 minutes. (See table 2) which is due to the low proportion of liquid / solid epoxy resins of approximately 1.93.

Comparative Example 2 An unsupported pressure sensitive adhesive film having the composition specified in Table 1 was prepared according to the method of Example 1. Although it comprises the amorphous polyester DYNAPOL S 1313, the pressure sensitive adhesive film is not supported exhibits a holding power of less than 5 minutes (see table 2) because the ratio of müu + dii) / m (i) is 1.75 which is too high to give the required elasticity of the pressure-sensitive adhesive tape.

Comparative Example 3 An unsupported pressure sensitive adhesive film having the composition specified in Table 1 was prepared according to the method of Example 1. Although it comprises the amorphous polyester DYNAPOL S 1313, the pressure sensitive adhesive film not supported exhibits a hold power of virtually 0 minutes (see table 2) resulting from the low ratio of m? / ms to 0.

Comparative Examples 4-18 Unsupported pressure sensitive adhesive films having the composition specified in Table 1 were prepared according to the method of Example 1. The films were tested according to the test methods specified above and the results obtained. they are summarized in table 2. The adhesive films of comparative examples 1-16 comprising slightly crystalline and moderately crystalline polymers exhibit insufficient values of retention power.

Table 1 Table 1 (continued) Table 2 Table 2 (continued) N / A: Not applicable. The test could not be carried out because the materials had very little cohesion resistance to be handled, a hold power of virtually 0 minutes and / or no appropriate sample could be obtained for the respective test. N / T: not tested. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Claims (11)

1. Claims Having been described in the invention as above, the content of the following claims is claimed as property: 1. A pressure-sensitive adhesive tape with improved room temperature handling, characterized in that it comprises at least one layer of pressure-sensitive adhesive. with at least one exposed surface and optionally a support, wherein the pressure-sensitive adhesive layer comprises an epoxy / polyester-based pressure sensitive adhesive comprising: (i) 30-80% by weight of a silicone component; polyester comprising one or more amorphous polyester compounds; (ii) 20-70% by weight of an epoxy component comprising one or more epoxy resins and / or monomers; (iii) 0-50% by weight in a functional hydroxyl component comprising one or more hydroxyl-containing compounds having a hydroxyl functionality of at least 1; and (iv) an effective amount of a photoinitiating component for crosslinking the pressure sensitive adhesive; wherein the percentages by weight refer to the total mass of the components (i) - (iv) and add up to 100% by weight and the pressure sensitive adhesive exhibits a holding power of at least 5 minutes and It is crosslinkable in the exposure to actinic radiation or electrons and optionally heat, to the point of losing its wetting properties.
2. 2. The pressure-sensitive adhesive tape according to claim 1, characterized in that the amorphous polyester compounds exhibit a glass transition temperature between -20 and 50 ° C.
3. 3. The pressure sensitive adhesive tape according to claims 1-2, characterized in that the proportion of the sum of the masses of the compounds of the components (i) - (ii) which are liquid at room temperature with respect to the total mass of the components (i) - (iii) is not more than 0.6.
4. 4. The pressure-sensitive adhesive tape according to claims 1-3, characterized in that the proportion of the sum of the masses of the components (ii) and (iii) with respect to the total mass of the components (i) - (iv) is between 0.2 and 0.7.
5. 5. The pressure-sensitive adhesive tape according to claims 1-4, characterized in that it exhibits a 90 ° release adhesion value at room temperature on stainless steel 20 minutes after application and at least 4 N / 1.27 cm (0.5 inches).
6. 6. The pressure sensitive adhesive tape according to claims 1-5, characterized in that it comprises a photoinitiating component consisting of one or more photoinitiators for cationic crosslinking.
7. 7. The pressure sensitive adhesive tape according to claim 6, characterized in that the photoinitiator component comprises one or more photoinitiators selected from the group consisting of aromatic onium complex salts and metallocene salts. The pressure sensitive adhesive tape according to claims 1-7, characterized in that the functional hydroxyl component comprises one or more compounds selected from the group consisting of extended bisphenol A polyols, glycol polyol adducts and oxides of propylene, polyols based on polycaprolactam and polyols based on polytetrahydrofuran. 9. A method for attaching or sticking a first substrate to a second substrate with a pressure sensitive adhesive tape according to claims 1-8 having two exposed adhesive surfaces, the method is characterized in that it comprises the steps of applying a first one. exposed surface of the pressure sensitive adhesive tape the first substrate and join the second substrate to a second exposed surface of the pressure sensitive adhesive, whereby the pressure sensitive adhesive is subjected to actinic or electron beam irradiation and optionally heat before gluing them to the respective substrate in the post-cure bonding time or after sticking them or joining them to the respective substrates. 10. The method of compliance with the claim 9, characterized in that the first and second substrates are selected from the group comprising glass, glass coated ceramic, metal, plastic or ceramic. 11. An assembly characterized in that it is obtainable by a method according to claims 9-10.