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
  • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
  • C09J175/04—Polyurethanes
  • C09J175/14—Polyurethanes having carbon-to-carbon unsaturated bonds
  • C09J175/16—Polyurethanes having carbon-to-carbon unsaturated bonds having terminal carbon-to-carbon unsaturated bonds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
  • C08F283/006—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polymers provided for in C08G18/00
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
  • C08F290/02—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated end groups
  • C08F290/06—Polymers provided for in subclass C08G
  • C08F290/067—Polyurethanes; Polyureas
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/81—Unsaturated isocyanates or isothiocyanates
  • C08G18/8141—Unsaturated isocyanates or isothiocyanates masked
  • C08G18/815—Polyisocyanates or polyisothiocyanates masked with unsaturated compounds having active hydrogen
  • C08G18/8158—Polyisocyanates or polyisothiocyanates masked with unsaturated compounds having active hydrogen with unsaturated compounds having only one group containing active hydrogen
  • C08G18/8175—Polyisocyanates or polyisothiocyanates masked with unsaturated compounds having active hydrogen with unsaturated compounds having only one group containing active hydrogen with esters of acrylic or alkylacrylic acid having only one group containing active hydrogen

Definitions

• the invention relates to a solvent-free or solvent-containing, low-monomer reactive adhesive with multi-stage curing, its production and its use as a laminating and coating adhesive for composite materials.
• adhesives based on polyurethane (PU) prepolymers that have reactive end groups are often used to produce composite materials, in particular composite foils.
• reactive adhesives there are end groups which can react with water or other compounds which have an acidic hydrogen atom.
• This form of reactivity makes it possible to bring the reactive PU prepolymers in the processable state (usually liquid to highly viscous) to the desired location in the desired manner and by adding water or other compounds that have an acidic hydrogen atom ( in this case called hardener) harden.
• the hardener is usually added immediately before application, with the processor only having a limited processing time after adding the hardener.
• the polyurethanes with reactive end groups usually used in 1K or 2K systems include, for example, the polyurethanes with preferably terminal isocyanate (NCO) groups.
• NCO terminal isocyanate
• polyfunctional alcohols with an excess of monomeric polyisocyanates, generally at least predominantly diisocyanates.
• a content of monomeric polyisocyanate has a disruptive effect, for example, when it comes to volatile diisocyanates: adhesives / sealants and, in particular, PU-based hotmelt adhesives are processed at elevated temperature.
• the processing temperatures of hot melt adhesives are between 100 ° C and 200 ° C, those of laminating adhesives between room temperature and 150 ° C. Even at room temperature, volatile diisocyanates, such as IPDI or TDI, have a vapor pressure that should not be neglected.
• volatile means substances which have a vapor pressure of more than about 0.0007 mm Hg or a boiling point of less than about 190 ° C (70 mPa) at about 30 ° C.
• PU prepolymers or adhesives based thereon are generally obtained with a viscosity which is usually outside the range for simple Processing methods usable range. This also happens / or additionally if you want to reduce the monomer content by reducing the NCO / OH ratio. In these cases, the viscosity of the polyurethane prepolymers can be reduced by adding suitable solvents.
• Another possibility for lowering the viscosity is to add an excess of monofunctional or polyfunctional monomers, for example monomeric polyisocyanates, as so-called reactive diluents.
• monofunctional or polyfunctional monomers for example monomeric polyisocyanates
• reactive diluents for example monomeric polyisocyanates
• the content of the resulting amines, especially the primary aromatic amines, must be below the detection limit of 0.2 micrograms of aniline hydrochloride / 100 ml sample based on aniline hydrochloride (Federal Institute for Consumer Health Protection and Veterinary Medicine, BGW, after official collection of test methods according to ⁇ 35 LMBG - Examination of foods / Determination of primary aromatic amines in aqueous test foods).
• Migrates are undesirable in the packaging sector, especially in food packaging.
• the migration of the migrates through the packaging material can lead to contamination of the packaged goods, on the other hand, depending on the amount of migratable free monomeric polyisocyanate, long waiting times are necessary before the packaging material is "Migrat-free" and may be used.
• Another undesirable effect that can be caused by the migration of monomeric polyisocyanates is the so-called anti-sealing effect in the production of bags or carrier bags from laminated plastic films: Often they contain laminated plastic films a lubricant based on fatty acid amides. By reaction of migrated monomeric polyisocyanate with the fatty acid amide and / or moisture, urea compounds are formed on the surface of the film which have a melting point which can be above the sealing temperature of the plastic films. This creates an alien anti-seal layer between the film parts to be sealed, which counteracts a uniform seal seam formation.
• Reactive adhesives that are suitable for the production of composite materials should therefore have a suitable processing viscosity, but if possible should not release or contain any volatile or migrable substances into the environment. Furthermore, there is a requirement for such reactive adhesives that, immediately after application to at least one of the materials to be joined, after they have been joined, they have a sufficiently good initial adhesion, which prevents the composite material from separating into its original constituents or a displacement of the bonded materials against one another as far as possible prevented. In addition, however, such an adhesive bond should also have a sufficient degree of flexibility to withstand the various tensile and tensile loads to which the composite material which is still in the processing stage is usually exposed, without damage to the adhesive bond and without damage to the bonded material, to survive.
• This methodology is described, for example, in DE 40 41 753 A1 and relates to reactive contact adhesives, processes for their production and their use.
• the publication describes two-stage polymerizable coating compositions based on urethane, which can be cured by a content of UV-polymerizable acrylate groups in the course of a first curing stage to form a solidified, but still structurally deformable or embossable material, followed by irreversible consolidation in a subsequent second stage.
• monofunctional acrylates are added to the adhesive as a reactive thinner.
• the adhesive described has pressure tack after irradiation; the intended use of the contact adhesive described is the bonding of wood and / or plastic parts at up to about 70 ° C., preferably at room temperature.
• the reactive adhesive should provide sufficient flexibility of the adhesive connection after the adhesive bonding has been carried out and, after complete curing, should lead to composite materials with excellent strength values with respect to the adhesive connection.
• this reactive adhesive should not contain any low molecular weight compounds capable of migration or volatility.
• the object of the invention is achieved by a solvent-free or solvent-containing low-monomer reactive adhesive with multi-stage curing, the at least one polyurethane prepolymer (A) with a low content of monomeric polyisocyanate (a) and at least one free one, for reaction with at least one acidic one Functional group containing hydrogen atom capable, in particular at least one isocyanate group, and contains at least one compound (B) with at least one functional group polymerizable by radiation.
• the low-monomer reactive adhesive contains in particular a polyurethane prepolymer (A), obtainable by reacting a) at least one monomeric polyisocyanate (a), b) at least one polyol (b) c) optionally at least one compound (c) which can be polymerized both by radiation has functional groups as well as at least one acidic hydrogen atom and d) optionally at least one silicon-organic compound (d).
• A polyurethane prepolymer
• Low-monomer reactive adhesive is understood to mean a reactive adhesive with a content of less than 0.1% by weight of monomeric polyisocyanate (a).
• Low content of monomeric polyisocyanate means a content of less than 0.5% by weight. , preferably less than 0.3% by weight and particularly preferably less than 0.1% by weight of monomeric polyisocyanate (a), based on the overall composition of the polyurethane prepolymer (A).
• a “polymerizable functional group” is understood to mean a group which can react by radical, anionic or cationic polymerization, polycondensation or polyaddition with a suitable further functional group while increasing the molecular weight of the molecule carrying it.
• the functional group is generally preferably an olefinically unsaturated double bond.
• the functional group can be, for example, an acid group or an alcohol group; in the case of polyaddition, for example, isocyanate groups or epoxy groups are suitable as functional groups.
• Irradiation is understood to mean irradiation with UV light or with electron beams.
• a functional group which can be polymerized by irradiation with UV light or with electron beams is, for example, a group with olefinically unsaturated ones Double bond.
• olefinically unsaturated double bonds are preferred, such as those present in the derivatives of acrylic acid or styrene.
• the derivatives of acrylic acid for example the acrylates and the methacrylates, are particularly suitable and preferred in the context of the present invention.
• the “curing” or “curing” of a composition containing polymerizable compounds is generally based on a polymerization reaction which is accompanied by at least an increase in the molecular weight of the compounds contained in the composition.
• crosslinking reactions usually also take place at the same time.
• the terms “hardening”, “hardening” or similar terms in the context of the following text therefore refer to polymerization reactions as can occur within individual components of the composition in each case in connection with the term, for example the radiation-induced polymerization of a component bearing double bonds.
• the terms also refer to polymerization reactions as they can take place under various components of the composition under consideration, for example the reaction of a component carrying isocyanate groups with a component carrying OH groups.
• the terms also refer to polymerization reactions as they can take place between a component of the composition under consideration and a component entering the composition due to external influence, for example the reaction between isocyanate groups and air humidity.
• the functional group capable of reacting with a compound having at least one acidic hydrogen atom is, for example, the isocyanate group or the epoxy group in the context of the present invention, the isocyanate group being particularly preferred.
• a compound having an acidic hydrogen atom is understood to mean a compound which has an active hydrogen atom which can be determined by the Zerewittinoff test and is bound to an N, O or S atom.
• active hydrogen atom which can be determined by the Zerewittinoff test and is bound to an N, O or S atom.
• These include in particular the hydrogen atoms of water, carboxy, amino, imino, Hydroxy and thiol groups. Water is particularly preferred in the context of the present invention, or those compounds which have amino or hydroxyl groups or both, or mixtures of two or more thereof.
• the polyurethane prepolymers (A) which can be used according to the invention can be prepared by reacting at least one monomeric polyisocyanate (a), or a mixture of two or more monomeric polyisocyanates, with at least one compound having at least one acidic hydrogen atom.
• Suitable monomeric polyisocyanates contain an average of two to at most about four isocyanate groups.
• diisocyanates as the monomeric polyisocyanates.
• Suitable monomeric polyisocyanates are: 1, 5-naphthylene diisocyanate, 2,2'-, 2,4- and / or 4,4'-diphenylmethane diisocyanate (MDI), hydrogenated MDI (H 12 MDI), ailophanates of MDI, xylylene diisocyanate ( XDI), tetramethylxylylene diisocyanate (TMXDI), 4,4'-diphenyldimethylmethane diisocyanate, di- and tetraalkylene diphenylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, the isomers of tolylene diisocyanate (methylene diisocyanate), 1-tolylene diisocyanate -2,4-diisocyanato-cyclohexane, 1,6-diiso
• 1-bromomethylphenyl-2,6-diisocyanate 3,3-bis-chloromethyl ether-4,4'-diphenyldiiso-cyanate.
• Sulfur-containing polyisocyanates are obtained, for example, by reacting 2 mol of hexamethylene diisocyanate with 1 mol of thiodiglycol or dihydroxydihexyl sulfide.
• Other diisocyanates that can be used include trimethylhexamethylene diisocyanate, 1,4-diisocyanatobutane, 1, 12-diisocyanatododecane and dimer fatty acid diisocyanate.
• tetramethylene hexamethylene, undecane, dodecamethylene
• 2,2,4-trimethylhexane-2,3,3-trimethyl-hexamethylene 1,3-cyclohexane, 1,4-cyclohexane, 1,3 - or 1, 4-tetramethylxylene
• isophorone 4,4-dicyclohexylmethane and lysine ester diisocyanate
• Tetramethylxylylene diisocyanate TXDI
• m-TMXDI from Cyanamid
• mixtures of 2 or more monomeric polyisocyanates contain polyisocyanates with uretdione, isocyanurate, allophanate, biuret, Iminooxathizindione and / or oxadiazinetrione structure.
• Polyisocyanates or polyisocyanate mixtures with an allophanate structure based on HDI, IPDI and / or 2,4 ' - or 4,4 ' - diisocyanatodicyclohexyimethane are particularly preferred.
• Polyisocyanates containing oxadiazinetrione groups can be prepared from diisocyanate and carbon dioxide.
• Suitable at least trifunctional isocyanates are polyisocyanates which are formed by trimerization or oligomerization of diisocyanates or by reaction of diisocyanates with polyfunctional compounds containing hydroxyl or amino groups.
• Isocyanates suitable for the production of trimers are the diisocyanates already mentioned, the trimerization products of the isocyanates HDI, MDI, TDI or IPDI being particularly preferred.
• polykisisocyanates such as 1,3,5-tris [6- (1-methyl-propylidene-aminoxycarbonylamino) -hexyl] -2,4,6-trixo -hexahydro-1, 3,5-triazine.
• polymeric isocyanates such as those obtained as a residue in the distillation bottoms from the distillation of diisocyanates.
• polymeric MDI as is available in the distillation of MDI from the distillation residue, is particularly suitable.
• IPDI, HDI, MDI and / or TDI is preferably used as monomeric polyisocyanate (a) individually or in a mixture.
• Suitable compounds having at least one acidic hydrogen atom are, for example, polyols (b).
• Polyols are understood to mean compounds which carry at least two hydroxy (OH) groups as functional groups.
• Suitable as polyol (b) is, for example, a polymer selected from a group comprising polyesters, polyethers, polyacetals or polycarbonates with a molecular weight (M n ) of at least about 200 g / mol, or mixtures of two or more thereof, the terminal OH groups exhibit.
• Polyesters which can be used as polyol (b) for the preparation of the PU prepolymer (A) in the context of the present invention can be obtained in a manner known to the person skilled in the art by polycondensation of acid and alcohol components, in particular by polycondensation of a polycarboxylic acid or a mixture of two or more Polycarboxylic acids and a polyol or a mixture of two or more polyols.
• polycarboxylic acids suitable for the preparation of the polyol (b) can be based on an aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic base body and, if appropriate, in addition to the at least two carboxylic acid groups, one or more substituents which are non-reactive in the context of a polycondensation, for example Halogen atoms or olefinically unsaturated double bonds.
• substituents which are non-reactive in the context of a polycondensation for example Halogen atoms or olefinically unsaturated double bonds.
• their anhydrides (where they exist), or esters thereof with C ⁇ ⁇ - are monoalcohols, or mixtures of two or more thereof, used for polycondensation.
• Suitable polycarboxylic acids are, for example, adipic acid, hydrophthalic succinic acid suberic acid, azelaic acid, sebacic acid, glutaric acid, glutaric anhydride, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetra-, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, dimer fatty acids or trimer fatty acids or Mixtures of two or more of them. If necessary, minor amounts of monofunctional fatty acids can be present in the reaction mixture.
• polyols can be used as diols for producing a polyester or polycarbonate which can be used as polyol (b).
• these are aliphatic polyols with 2 to 4 OH groups per molecule.
• the OH groups can be bound either primary or secondary.
• Suitable aliphatic polyols include, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3, 2,3-butanediol, 1,4-butenediol, 1,4-butynediol , Pentanediol-1, 5, and the isomeric pentanediols, pentenediols or pentindiols or mixtures of two or more thereof, hexanediol-1, 6, and the isomeric hexanediols, hexenediols or hexindiols or mixtures of two or more thereof, heptanediol-1, 7 as well as the isomeric heptane, heptene or heptine diols, octanediol I, 8 and the
• Highly functional alcohols such as, for example, glycerol, trimethylol propane, pentaerythritol or sugar alcohols such as sorbitol or glucose, and oligomeric ethers of the substances mentioned with themselves or in a mixture of two or more of the compounds mentioned, for example polyglycerol with a degree of polymerization of about 2, are also suitable to about 4.
• one or more OH groups can be esterified with monofunctional carboxylic acids having 1 to about 20 C atoms, with the proviso that on average at least two OH groups are retained.
• the higher-functionality alcohols mentioned can be used in pure form or, if possible, as the technical mixtures obtainable in the course of their synthesis.
• Polyether polyols can also be used as polyol (b).
• Polyether polyols which are to be used as polyol (b) or for the preparation of polyesters suitable as polyol (b) are preferably obtained by reacting low molecular weight polyols with alkylene oxides.
• the alkylene oxides preferably have two to about four carbon atoms.
• Suitable examples are the reaction products of Ethylengiyk 'ol, propylene glycol, the isomeric butanediols or hexanediols, as mentioned above, or mixtures of two or more thereof, with ethylene oxide, propylene oxide or butylene oxide or mixtures of two or more thereof.
• polyether polyols obtainable from the reactions mentioned and having a molecular weight (M n ) of from about 100 to about 3,000 g / mol, preferably from about 200 to about 2,000 g / mol, are particularly suitable.
• M n molecular weight
• the polyether polyols mentioned can be reacted with the above-mentioned polycarboxylic acids in a polycondensation reaction to give the polyesters which can be used as polyol (b).
• polyether polyols such as those formed in the manner described above.
• Polyether polyols are usually obtained by reacting a starter compound with at least two reactive hydrogen atoms with alkylene or arylene oxides, for example ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran or epichlorohydrin or mixtures of two or more thereof.
• Suitable starting compounds are, for example, water, ethylene glycol, propylene glycol-1, 2 or -1, 3, butylene glycol-1, 4, or -1, 3, hexanediol-1, 6, octanediol-1, 8, neopentylglycol, 1, 4-hydroxymethylcyclohexane , 2-methyl-1,3-propanediol, glycerin, trimethylolpropane, hexanetriol-1, 2,6, butanetriol-1, 2,4, trimethylolethane, pentaerythritol, mannitol, sorbitol, methylglycosides, sugar, phenol, isononylphenol, resorcinol, hydroquinone , 1, 2,2- or 1, 1, 2-tris- (hydroxyphenyl) -ethane, ammonia, methylamine, ethylenediamine, tetra- or hexamethyleneamine, triethanolamine, aniline,
• a polyether polyol and / or polyester polyol with a molar mass of 200 to 4000, preferably from 200 to 2000 g / mol, or a mixture of polyether polyols and / or polyester polyols, is particularly suitable for use as polyol (b) meet the restrictive criterion of molar mass.
• polyol (b) it is particularly advantageous if a mixture of one or more polyester polyols and one or more polyether polyols is used as the polyol (b).
• the various base polymers can differ, for example, in the molecular weight (M n ) or in the chemical structure, or in both.
• polyether polyols which have been modified by vinyl polymers.
• Such products are available, for example, in which styrene or acrylonitrile or a mixture thereof is polymerized in the presence of polyethers.
• Polyacetals are also suitable as polyol (b) or as a polyol component for the production of polyol (b).
• Polyacetals are understood to mean compounds as can be obtained by reacting glycols, for example diethylene glycol or hexanediol, with formaldehyde.
• Polyacetals which can be used in the context of the invention can also be obtained by the polymerization of cyclic acetals.
• Polycarbonates are also suitable as polyol (b) or as polyols for the production of polyol (b).
• Polycarbonates can be produced, for example, by the reaction of the abovementioned polyols, in particular diols such as propylene glycol, 1,4-butanediol or 1,6-hexanediol, diethylene glycol, triethylene glycol or tetraethylene glycol or mixtures two or more of them can be obtained with diaryl carbonates, for example diphenyl carbonate or phosgene.
• polyurethane prepolymers (A) with a low content of monomeric polyisocyanate and at least one free functional group capable of reacting with at least one compound having at least one acidic hydrogen atom , for example amines but also water.
• amines for example amines but also water.
• Amino alcohols such as ethanolamine, propanolamine, butanolamine, N-methylethanolamine, N-methylisopropanolamine, diethanolamine
• the polyol (b) is preferably reacted with the monomeric polyisocyanate (a) in a ratio of 1:> 2.
• an NCO: OH ratio of 2: 1 to 10: 1 is preferred, in particular an NCO: OH ratio of 3: 1 to 7: 1 is preferred.
• the reaction can take place, for example, in the presence of solvents.
• solvents In principle, all solvents commonly used in polyurethane chemistry can be used as solvents, in particular esters, ketones, halogenated hydrocarbons, alkanes, alkenes and aromatic hydrocarbons.
• solvents examples include methylene chloride, trichlorethylene, toluene, xylene, butyl acetate, amyl acetate, isobutyl acetate, methyl isobutyl ketone, methoxybutyl acetate, cyclohexane, cyclohexanone, dichlorobenzene, diethyl ketone, di-isobutyl ketone, dioxane, ethyl acetate, ethyl acetate, ethylene glycol monoethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylacetylethylace
• reaction components themselves are liquid or at least one or more of the reaction components form a solution or dispersion of further, insufficiently liquid reaction components, the use of solvents can be dispensed with entirely. Such a solvent-free reaction is preferred in the context of the present invention.
• the temperature is usually raised to accelerate the reaction. As a rule, the temperature is raised to about 40 to about 80 ° C. The onset of exothermic reaction then causes the temperature to rise.
• the temperature of the batch is kept at about 70 to about 110 ° C, for example at about 85 to 95 ° C or in particular at about 75 to about 85 ° C, if necessary the temperature is adjusted by suitable external measures, for example heating or cooling.
• customary catalysts can optionally be added to the reaction mixture.
• the addition of dibutyltin dilaurate or diazabicyclooctane (DABCO) is preferred. If it is desired to use a catalyst, the catalyst is generally added to the reaction mixture in an amount of about 0.001% by weight or about 0.01% by weight to about 0.2% by weight, based on the overall batch ,
• the reaction time depends on the polyol (b) used, on the monomeric polyisocyanate (a), on the reaction temperature and on the catalyst which may be present.
• the total reaction time is usually about 30 minutes to about 20 hours.
• the low content of monomeric polyisocyanate (a) in the polyurethane prepolymer (A) is achieved by removing the monomeric polyisocyanate (a) from the reaction product after the reaction of at least one monomeric polyisocyanate (a) with at least one polyol (b).
• the purification step can be carried out according to processes known per se, such as distillation, extraction, chromatography or crystallization processes, as well as from combinations of these processes.
• Non-solvents are in particular non-polar aprotic organic solvents such as e.g. Ethyl acetate, chlorobenzene, xylenes, toluene, or in particular boiling-point spirit.
• the excess monomeric polyisocyanate (a) can also be removed from the reaction mixture by distillation.
• the distillation is preferably carried out in vacuo with the aid of a thin-film evaporator or a thin-film evaporator.
• Another possibility of removing the monomeric polyisocyanate (a) from the reaction mixture is the selective extraction of the monomeric polyisocyanate (a), for example using supercritical carbon dioxide or other supercritical aprotic solvents. This extraction method is known for example from WO-97/46603.
• a polyurethane prepolymer (A) with a low content of monomeric polyisocyanate (a) which bears two functional groups through which Reaction with a compound having at least one acidic hydrogen atom are polymerizable.
• the polyurethane prepolymer (A) belongs to the group of NCO-terminated polyurethane prepolymers, obtainable by reacting polyols with IPDI, MDI, HDI and / or TDI.
• the polyurethane prepolymer (A) belongs to the group of NCO-terminated PU prepolymers, obtainable by reacting a mixture of a polyether polyol and / or polyester polyol with a molecular weight of about 800 to about 2000 and a polyether polyol and / or polyester polyol with a molecular weight of about 200 to about 700 with IPDI, MDI, HDI and / or TDI.
• the PU prepolymers (A) obtained in this way are freed from excess monomeric polyisocyanate (a), preferably by the thin-film distillation process, and, after this cleaning step, have a residual content of less than 0.5% by weight of monomeric polyisocyanate.
• a compound (c) is used to produce the PU prepolymer (A), which has both at least one functional group which can be polymerized by irradiation and at least one acidic hydrogen atom.
• Irradiation is understood to mean, in particular, irradiation with UV light or with electron beams.
• Compound (c) particularly preferably has, as a functional group polymerizable by irradiation with UV light or with electron beams, a group with an olefinically unsaturated double bond.
• the molar mass of compound (c) is in the range from 100 to 15,000 g / mol, preferably from 100 to 10,000 g / mol and particularly preferably from 100 to 8000 g / mol.
• Suitable for use as compound (c) are all polymeric compounds which can usually be used in adhesives, for example polyacrylates, polyesters, polyethers, polycarbonates, polyacetals, polyurethanes, polyolefins, or rubber polymers such as nitrile or styrene / butadiene rubber, provided that they contain at least one by irradiation functional group polymerizable with UV light or with electron beams and having at least one acidic hydrogen atom.
• polyacrylates, polyester acrylates, epoxy acrylates or polyurethane acrylates are preferably used as compound (c) for the preparation of the polyurethane prepolymer (A), since the polymers mentioned offer a particularly simple possibility of attaching the functional groups required according to the invention to the polymer molecule.
• Polyacrylates bearing OH groups are particularly suitable as compound (c).
• Such polyacrylates can be obtained, for example, by polymerizing ethylenically unsaturated monomers which carry OH groups.
• Such monomers are obtainable, for example, by the esterification of ethylenically unsaturated carboxylic acids and difunctional alcohols, the alcohol generally being only in a slight excess.
• Suitable, ethylenically unsaturated carboxylic acids are, for example, acrylic acid, methacrylic acid, crotonic acid or maleic acid.
• Corresponding acrylate esters or hydroxyalkyl (meth) acrylates carrying OH groups are, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate or 3-hydroxypropyl methacrylate or mixtures of two or more thereof.
• the molar ratios between the monomeric polyisocyanate (a), the polyol (b) and optionally the compound (c) are such that after component (a) has reacted with (b) and then the excess monomeric polyisocyanate (a) has been removed.
• the PU prepolymer (A) still contains 1 to 30% by weight, preferably 1 to 20% by weight, of free NCO groups. If, in addition to (a) and (b), the compound (c) is used to prepare the PU prepolymer (A), (A) contains 1 to 20% by weight, preferably 1 to 10% by weight and particularly preferably 1 up to 5% by weight of free NCO groups.
• the reaction ratio of components (a), (b) and (c) is chosen so that both good adhesion and cohesion are achieved.
• the proportion of functional groups polymerizable by irradiation with UV light or with electron beams determines the initial strength and the proportion of functional groups reactive with a compound having at least one acidic hydrogen atom determines the final strength of the bond.
• Good results can be obtained, for example, if 1 to 90% of the functional groups present as terminal groups in the polymer by irradiation with UV light or are functional groups polymerizable with electron beams, preferably 5 to about 80%, and particularly preferably 8 to about 75%.
• reactive adhesives based on polyurethane prepolymers with NCO end groups can lead to the development of carbon dioxide, which can have adverse effects on the surface structure, for example.
• reactive adhesives often do not adhere to smooth, inert surfaces, for example to surfaces made of glass, ceramic, metal or the like, which in some cases makes it necessary to use a primer before applying the reactive adhesive.
• an organic silicon compound preferably an alkoxysilane group, is introduced into the polyurethane as the reactive end group.
• an alkoxysilane of the general formula I is optionally used as component (d) as organic silicon compound for the preparation of the polyurethane prepolymer (A):
• X stands for a radical with at least one reactive functional group with acidic hydrogen, for example for a radical which has at least one OH, SH, NH, NH 2 --COOH or anhydride group or a mixture of two or more such groups.
• X stands for OH, SH, H 2 N- (CH 2 ) 2 -NH, (HO-C 2 H 4 ) 2 N or NH 2
• A for CH 2 , CH 2 -CH 2 or CH 2 -CH 2 -CH 2 or a linear or branched, saturated or unsaturated alkylene radical with 2 to about 12 C atoms or for an arylene radical with about 6 to about 18 C atoms or an arylene alkylene radical with about 7 to about 19 C - Atoms or a siloxane radical substituted with alkyl, cycloalkyl or aryl groups and having about 1 to about 20 Si atoms
• Z stands for -O- CH 3 , -CH 3 , -CH 2
• variable n stands for 0, 1 or 2.
• starting materials suitable as component (d) are H 2 N- (CH 2 ) 3 -Si (O- CH 2 -CH 3 ) 3 , HO-CH (CH 3 ) -CH 2 -Si (OCH 3 ) 3 , HO- (CH 2 ) 3 -Si (O-CH 3 ) 3, HO-CH 2 -CH 2 -O-CH 2 - CH 2 -Si (OCH 3 ), (HO-C 2 H 4 ) 2 N- (CH 2 ) 3 -Si (O-CH 3 ) 3 , HO- (C 2 H 4 -O) 3 -C 2 H 4 -N (CH 3 ) - (CH 2 ) 3-Si (O- C 4 H 9 ) 3 , H 2 N-CH 2 -C 6 H 4 -CH 2 -CH 2 -Si (O-CH 3 ) 3, HS- (CH 2 )
• the monomeric polyisocyanate (a) is first reacted with the polyol (b) in a step reaction to form a reaction product with preferably terminal NCO groups.
• the excess monomeric polyisocyanate (a) is then removed by means of one of the cleaning processes described, preferably by means of thin-film distillation.
• the free NCO groups of the reaction product of monomeric polyisocyanate (a) with polyol (b) are optionally reacted with the compound (c), which has both polymerizable functional groups by irradiation and at least one acidic hydrogen atom and / or the alkoxysilane (d) ,
• the one-pot reaction is also possible here, in which components (a) to (d) are allowed to react in only one step and then the excess monomeric polyisocyanate is removed by one of the cleaning methods described.
• Variants of the step reaction described above are also possible, for example the combination in the order (a) + (c) + (b) + (d) with subsequent removal of the excess monomeric polyisocyanate by one of the cleaning methods described.
• the reactive adhesives according to the invention contain at least one compound which has at least one and preferably two functional groups which can be polymerized by irradiation with UV light or with electron beams.
• functional groups polymerizable with UV light or with electron beams have compound (B) at least one group with olefinically unsaturated double bond.
• Particularly suitable compounds (B) are di- or higher-functional acrylate or methacrylate esters.
• Such acrylate or methacrylate esters include, for example, esters of acrylic acid or methacrylic acid with aromatic, aliphatic or cycloaliphatic polyols or acrylate esters of polyether alcohols.
• polyols can be used as polyols for the preparation of an acrylate or methacrylate ester which can be used as compound (B), as have already been described as polyol (b) for the preparation of the PU prepolymer (A).
• Acrylate esters of aliphatic polyols with 2 to about 40 carbon atoms include, for example, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylol propane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and (meth) acrylate esters of sorbitol and others sugar alcohols.
• These (meth) acrylate esters of aliphatic or cycloaliphatic diols can be modified with an aliphatic ester or an alkylene oxide.
• the aliphatic ester modified acrylates include, for example, neopentyl glycol hydroxypivalate di (meth) acrylate, caprolactone modified neopentyl glycol hydroxypivalate di (meth) acrylates and the like.
• the alkylene oxide-modified acrylate compounds include, for example, ethylene oxide-modified neopentyl glycol di (meth) acrylates, propylene oxide-modified neopentyl glycol di (meth) acrylates, ethylene oxide-modified 1,6-hexanediol (meth) acrylates or propylene oxide-modified 1,6-hexanediol (meth) acrylates or mixtures of two or more of them.
• Acrylate monomers based on polyether polyols include, for example, neopentyl glycol-modified (meth) acrylates, trimethylolpropane di (meth) acrylates,
• Trifunctional and higher functional acrylate monomers include, for example
• Pentaerythritol tetra (meth) acrylate tris [(meth) acryloxyethyl] isocyanurate, caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate or trimethylolpropane tetra (meth) acrylate or mixtures of two or more thereof.
• di-, tri- or higher-functional acrylate monomers mentioned which can be used according to the invention as component B are di-, tri- and tetrapropylene glycol diacrylate, neopentylglycol propoxylate di (meth) acrylate,
• Trimethylolpropane tri (meth) acrylate, trimethylolpropane monethoxytri (meth) acrylate and pentaerythritol triacrylate are preferred.
• (Meth) acrylate esters based on polyols containing urethane groups can be prepared by reacting the polyols (b) already mentioned with the monomeric polyisocyanates (a) already mentioned, so that at least partially OH-terminated polyurethane prepolymers are formed which contain (meth) acrylic acid to be esterified to the corresponding mono- or diester.
• a compound is used as compound (B) which can be obtained by reacting (a) with (c).
• Isocyanatourethane acrylates obtainable by reacting isocyanate, for example based on HDI, with acrylate polyols are particularly preferred.
• esters of acrylic acid or methacrylic acid are particularly suitable as so-called “reactive thinners”.
• Particularly suitable compounds are, for example, the acrylic or methacrylic acid esters of aromatic, cycloaliphatic, aliphatic, linear or branched C.
• ⁇ o-Monoalcohols or from corresponding ether alcohols for example n-butyl acrylate, 2-ethylhexyl acrylate, octyl / decyl acrylate, isobornyl acrylate, 3-methoxybutyl acrylate, 2-phenoxyethyl acrylate, benzyl acrylate or 2-methoxypropyl acrylate.
• the compound (B) makes up up to about 80% by weight, but preferably less, for example about 40% by weight, 30% by weight or about 20% by weight in the reactive adhesive according to the invention.
• the use of smaller amounts is also possible, for example the reactive adhesive according to the invention can also contain only 10% by weight or an amount of about 0.5 to about 8% by weight of compound (B).
• the reactive adhesive as component (C) can contain at least one photoinitiator, which initiates a polymerization of olefinically unsaturated double bonds under UV radiation.
• a photoinitiator is generally used which is capable of initiating a radical polymerization of olefinically unsaturated double bonds when irradiated with light at a wavelength of about 215 to about 480 nm.
• all commercially available photoinitiators which are compatible with the reactive adhesive according to the invention, ie which give at least largely homogeneous mixtures, are suitable in principle for use as component (C).
• Type I substances that fragment.
• examples include benzophenone, camphorquinone, quantacure (manufacturer: International Bio-Synthetics), Kayacure MBP (manufacturer Nippon Kayaku), Esacure BO (manufacturer: Fratelli Lamberti), Trigonal 14 (manufacturer: Akzo), photoinitiators from Irgacure ® -, Darocure ® - or Speedcure ® series (manufacturer: Ciba-Geigy), Darocure ® 1173 and / or Fi-4 (manufacturer: Eastman).
• Irgacure ® 651, Irgacure ® 369, Irgacure ® 184, Irgacure ® 907, Irgacure ® 1850, Irgacure ® 1173 (Darocure ® 1173), Irgacure ® 1116, Speedcure ® EDB, Speedcure ® ITX, Irgacure ® 784 or Irgacure are particularly suitable ® 2959 or mixtures of two or more of them. Also suitable is 2,4,6-trimethylbenzene diphenylphosphine oxide (Lucirin TPO, manufacturer: BASF AG), which can also be used in a mixture with one or more of the photoinitiators mentioned above.
• Conventional low molecular weight photoinitiators can contribute to migratation in composite materials.
• the photoinitiators contained in the reactive adhesive themselves are suitable as migrates, but a further source of migratory agents are also fragments of the photoinitiators, as may arise when the reactive adhesive is irradiated with UV rays.
• the aim is to avoid as far as possible migratable compounds in the reactive adhesive.
• the content of migratable compounds in the reactive adhesive according to the invention can generally be reduced even further if the photoinitiator has a molecular weight which largely complicates or even prevents migration.
• component (C) therefore contains, at least in part, a photoinitiator which has a molar mass of more than about 200 g / mol.
• a photoinitiator which has a molar mass of more than about 200 g / mol.
• Commercially available photoinitiators that meet this condition are, for example, Irgacure® 651, Irgacure® 369, Irgacure® 907, Irgacure® 784, Speedcure® EDB, or Speedcure® ITX.
• photoinitiators which fulfill the above-mentioned condition with regard to their molar mass can also be obtained by reacting a low molecular weight photoinitiator which has at least one acidic hydrogen atom, for example an amino group or an OH group, with a high molecular weight compound having at least one isocyanate group (polymer-bound photoinitiators).
• a low molecular weight photoinitiator which has at least one acidic hydrogen atom for example an amino group or an OH group
• a high molecular weight compound having at least one isocyanate group polymer-bound photoinitiators.
• Compounds which carry more than one photoinitiator molecule, for example two, three or more photoinitiator molecules are preferably used as the component.
• Such compounds can be obtained, for example, by reacting a polyol with suitable polyisocyanates and photoinitiators with at least one acidic hydrogen atom.
• polyols mentioned above can be used as polyols, but in particular neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol and their alkoxylation products with C 2 . 4 alkylene oxides.
• component (C) contains a photoinitiator which can be obtained by reacting an at least trihydric alcohol with caprolactone to form a polycaprolactone having at least three OH groups and having a molecular weight of about 300 to about 900, and then the polycaprolactone is linked by means of a monomeric polyisocyanate with 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methylpropan-1-one.
• Suitable monomeric polyisocyanates for reaction with the polyols mentioned are, for example, all the monomeric polyisocyanates (a) mentioned in the context of this text.
• the 2,4- and 2,6-isomers of tolylene diisocyanate (TDI) are particularly preferred, the isomers being able to be used in their pure form or as a mixture.
• photoinitiators which have an acidic hydrogen atom are suitable as photoinitiators for producing the polymer-bound photoinitiators.
• photoinitiators which can be used in component (C) can also be prepared by using a deficit of photoinitiator molecules with at least one acidic hydrogen atom in the preparation of component A. This leads to a connection of the photoinitiator to a molecule of the PU prepolymer (A).
• photoinitiator to a polymer chain, for example to the PU prepolymer (A), by adding the photoinitiator having a corresponding functional group in monomeric form to the reactive adhesive, and then, for example, during a Storage time of the reactive adhesive with a corresponding polymeric component, for example PU prepolymer (A), reacts.
• the photoinitiator with a functional group polymerizable by irradiation with UV light or with electron beams
• the functional group polymerizable with UV light or with electron beams being connected to the photoinitiator, for example, by reacting the photoinitiator with an unsaturated carboxylic acid
• suitable unsaturated carboxylic acids are acrylic acid or methacrylic acid.
• the reaction products of Irgacure® 2959 with acrylic acid or methacrylic acid are particularly suitable in the context of the present invention.
• component (C) which is both a photoinitiator and a functional group which can be polymerized by irradiation with UV light or with electron beams or a functional group capable of reacting with a compound having at least one acidic hydrogen atom , or both.
• the reactive adhesive according to the invention contains component (C) in an amount of 0 to 15% by weight, based on the total reactive adhesive.
• the reactive adhesive according to the invention can cure as a 1-component reactive adhesive after completion of a first curing stage by irradiation with, for example, electron beams or UV rays (in conjunction with a corresponding photoinitiator as component (C)) under the influence of atmospheric moisture to the required final strength.
• component (C) a photoinitiator as component (C)
• a quick attainment of a certain ultimate strength, ie, a high If the curing speed is required, for example in order to enable the bonded materials to be processed as quickly as possible, the curing speed based on curing by atmospheric humidity may be too low. In such cases, a hardener (D) can be added to the reactive adhesive before processing.
• the invention therefore also relates to a reactive adhesive which, in the form of a two-component reactive adhesive as hardener (D), contains 0 to 60% by weight of a compound having at least two functional groups, each having at least one acidic hydrogen atom.
• the molar mass of (D) is in a range from 50 to 10,000 g / mol, preferably 50 to 6,000 g / mol and particularly preferably in a range from 50 to 3000 g / mol.
• a hardener (D) is preferably a compound having at least two functional groups, each having at least one acidic hydrogen atom, or a mixture of two or more such compounds which can react with the corresponding functional group of the PU prepolymer (A).
• the corresponding functional groups of the PU prepolymer (A) are understood to mean all the functional groups present in the PU prepolymer (A) which cannot be polymerized by irradiation under the conditions according to the invention, in particular isocyanate groups.
• Primary or secondary amino groups, mercapto groups or OH groups are particularly suitable as functional groups with at least one acidic hydrogen atom that are reactive with the corresponding functional groups of the PU prepolymer (A).
• the compounds which can be used as hardeners (D) can each contain amino groups, mercapto groups or OH groups exclusively or in a mixture.
• the reactive adhesive according to the invention preferably contains a compound having at least two OH groups as hardener (D).
• the functionality of the compounds that can be used in the hardener (D) is generally at least about two.
• the hardener (D) preferably has a proportion of more highly functional compounds, for example with a functionality of three, four or more.
• the total (average) functionality of the hardener (D) is, for example, about two (for example if only difunctional compounds are used as the hardener (D)) or more, for example about 2.1, 2.2, 2.5, 2.7 , or 3. If appropriate, the hardener (D) can have an even higher functionality, for example about four or more.
• the hardener (D) preferably contains a polyol carrying at least two OH groups.
• the hardener (D) is generally used in an amount such that the ratio of functional groups of the component (A) reactive with the hardener (D) to groups of the hardener (D) reactive with corresponding functional groups of the component (A) is approximately 5: 1 to about 1: 1, in particular about 2: 1 to about 1: 1.
• the reactive adhesive according to the invention generally has a viscosity of 100 mPa.s to 26,000 mPa.s at 70 ° C. (measured according to Brookfield, RVT DV-II digital viscosimeter, spindle 27).
• the viscosity of the adhesive is selected so that it has a viscosity of about 1,000 mPas to about 5,000 mPas (measured according to Brookfield, RVT DV-II digital viscosimeter, spindle 27) at typical processing temperatures.
• Typical processing temperatures are, for example, approximately 25 to approximately 70 ° C. in the production of flexible packaging films (flexible packaging), approximately 70 to approximately 80 ° C. in the lamination of high-gloss films and approximately 80 to approximately 130 ° C. in textile applications.
• the reactive adhesive according to the invention can also contain, as component (E), additives which may have a proportion of up to about 50% by weight of the total adhesive.
• additives (E) which can be used in the context of the present invention include, for example, plasticizers, stabilizers, antioxidants, adhesion promoters, dyes or fillers.
• plasticizers used are plasticizers based on phthalic acid, in particular dialkyl phthalates, phthalic esters which have been esterified with an alkanol having from about 6 to about 14 carbon atoms being preferred. Di-isononyl or di-iso-tridecyl phthalate are particularly preferred.
• plasticizers for example sucrose benzoate, diethylene glycol dibenzoate and / or diethylene glycol benzoate, in which about 50 to about 95% of all hydroxyl groups have been esterified, phosphate plasticizers, for example t-butylphenyldiphenylphosphate, polyethylene glycols and their derivatives, for example diphenyl ether, of poly (ethylene glycol), liquid resin derivatives, for example the methyl ester of hydrogenated resin, vegetable and animal oils, for example glycerol esters of fatty acids and their polymerization products.
• phosphate plasticizers for example t-butylphenyldiphenylphosphate
• polyethylene glycols and their derivatives for example diphenyl ether
• liquid resin derivatives for example the methyl ester of hydrogenated resin
• vegetable and animal oils for example glycerol esters of fatty acids and their polymerization products.
• Stabilizers or antioxidants which can be used as additives (E) in the context of the invention include phenols, sterically hindered phenols of high molecular weight (M n ), polyfunctional phenols, sulfur- and phosphorus-containing phenols or amines.
• Phenols which can be used as additives in the context of the invention are, for example, hydroquinone, hydroquinone monomethyl ether 2,3- (di-tert-butyl) hydroquinone, 1,3,5-trimethyl-2,4,6-tris (3,5-di tert-butyl-4-hydroxybenzyl) benzene; Butylated hydroxytoluene (BHT), pentaerythritol tetrakis 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate; n-octadecyl-3,5-di-tert-butyl-4-hydroxyphenyl) propionate; 4,4-methylenebis (2,6-di-tert-butyl-phenol); 4,4-thiobis (6-tert-butyl-o-cresol); 2,6-di-tert-butylphenol; 2,6-di-tert-butyl-n-
• OctyIthio ethyl-3,5-di-tert-butyl-4-hydroxybenzoate; and sorbitol hexa [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]; and p-hydroxydiphenylamine or N, N'-diphenylenediamine or phenothiazine.
• the reactive adhesive according to the invention can contain adhesion promoters as component (E).
• Adhesion promoters are substances that improve the adhesive strength of materials to be combined. In particular, adhesion promoters are said to improve the aging behavior of bonds to moist atmospheres.
• Typical adhesion promoters are, for example, ethylene / acrylamide comonomers, polymeric isocyanates, reactive organosilicon compounds or phosphorus derivatives.
• phosphorus derivatives are preferably used as adhesion promoters, as are disclosed in WO 99/64529 (page 7, line 14 to page 9, line 5), for example 2-methacryloyloyethyl phosphate, bis (2-methacryloxyoxyethyl) ) phosphate, or mixtures thereof.
• (Meth) acrylate carboxylic acid-containing compounds can also be used as adhesion promoters. Compounds of this type are disclosed, for example, in WO 01/16244 (page 7, line 7 to page 8, line 31) or in WO 00/29456 (page 11, line 15 to page 12, line 2).
• Commercially available products are for example from UCB-Chemicals, B- 1620 Drugsbos, Belgium under the product class "Ebecryl", for example Ebecryl 168 or Ebecryl 170, available.
• Further additives (E) can be included in the reactive adhesives according to the invention in order to vary certain properties. These can include, for example, dyes such as titanium dioxide, fillers such as talc, clay and the like. If necessary, small amounts of thermoplastic polymers can be present in the adhesives according to the invention, for example ethylene vinyl acetate (EVA), ethylene acrylic acid, ethylene methacrylate and ethylene-n-butyl acrylate copolymers, which optionally give the adhesive additional flexibility, toughness and strength.
• EVA ethylene vinyl acetate
• EVA ethylene acrylic acid
• methacrylate ethylene methacrylate
• ethylene-n-butyl acrylate copolymers which optionally give the adhesive additional flexibility, toughness and strength.
• hydrophilic polymers for example polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl methyl ether, polyethylene oxide, polyvinyl pyrrolidone, polyethyloxazoline or starch or cellulose esters, in particular the acetates with a degree of substitution of less than 2.5, which, for example, increase the wettability of the adhesives.
• the solvent-free or solvent-containing low-monomer reactive adhesive with multi-stage curing preferably contains
• V 0 to 50% by weight, preferably 1 to 20% by weight of additives (E), the sum of the constituents mentioned giving 100% by weight.
• reaction adhesive according to the invention can still contain up to 60% by weight of an inert solvent, which have already been described in the preparation of the polyurethane prepolymer (A).
• the reactive adhesives according to the invention can be produced by customary techniques known to the person skilled in the art in the production of polymeric mixtures.
• the reactive adhesive according to the invention can be used in the bonding of a wide variety of materials.
• the materials that can be glued include for example wood, metal, glass, plant fibers, stone, paper, cellulose hydrate, plastics such as polystyrene, polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, copolymers of vinyl chloride and vinylidene chloride, copolymers of vinyl acetate olefins, polyamides, or metal foils, for example made of aluminum, lead or Copper.
• the reactive adhesive according to the invention is used in the production of composite materials.
• the reactive adhesive according to the invention is particularly suitable for composite materials which are used in the food packaging sector.
• Another object of the present invention is therefore also a method for producing composite materials, characterized in that a reactive adhesive according to the invention is used.
• the composite materials which can be produced with the aid of the reactive adhesive according to the invention are film composites which can be obtained by partially or completely gluing films.
• the reactive adhesive according to the invention can be applied to the materials to be bonded, in particular the foils, using machines which are usually used for such purposes, for example conventional laminating machines.
• the application of the reactive adhesive in the liquid state to a film to be bonded to a laminate is particularly suitable.
• the film coated with the reactive adhesive in this way is laminated with at least one second film, optionally under pressure, and then irradiated with UV light or electrons.
• the film coated with the reactive adhesive is first transferred to an irradiation zone in which the polymerization reaction, that is to say the crosslinking of the individual components, is initiated by irradiation with ultraviolet radiation or electron radiation.
• the reactive adhesive according to the invention becomes sticky due to the radiation and the associated crosslinking reaction of the individual components contained in the reactive adhesive, for example contact sticky, but preferably pressure sensitive.
• the first film coated with the irradiated reactive adhesive is laminated with at least one second film, if appropriate with the application of pressure. This procedure is particularly advantageous when two films are to be glued together which are not transparent to the radiation required to initiate the polymerization.
• the described gluing and laminating processes can be repeated several times, so that laminates can be produced which consist of more than two glued layers.
• the bonding and lamination processes described are usually carried out under a protective gas atmosphere, ie in the presence of inert gases such as nitrogen.
• a protective gas atmosphere ie in the presence of inert gases such as nitrogen.
• the described bonding and laminating processes with the reactive adhesive according to the invention can also be carried out without any problems under a normal atmosphere, as typically prevails in the production halls.
• the invention thus also relates to a composite material produced by a method according to the invention using a reactive adhesive according to the invention.
• the reactive adhesive according to the invention can be applied to the surfaces to be bonded by all suitable methods, for example by spraying, knife coating, 3-4 roller application units in the case of using a solvent-free reactive adhesive or 2 roller application units in the case of using a solvent-containing reactive adhesive.
• NCO value of the end product 6.08% by weight; Monomer content: ⁇ 0.1% by weight; Brookfield viscosity at 50 ° C: 8300 mPa.s
• NCO value of the end product 2.4% by weight (theoretical value: 2.8% by weight), Brookfield viscosity at 70 ° C: 8600 mPa.s
• NCO adduct (2) In a three-necked flask equipped with a stirrer, thermometer and drying tube, 263.76 g of the above-mentioned NCO adduct (2) are heated to 40 ° C. with stirring and then tert with 0.5 g of 2,6-di. butyl-4-methylphenoI added. After ten minutes, 36.24 g of hydroxypropyl acrylate are added. The mixture is allowed to react at 70-75 ° C for four hours and is then bottled. NCO value of the end product: 3.5% by weight (theoretical value: 3J5%); Brookfield viscosity at 70 ° C: 4000 mPa.s
• NCO value of the end product 3.9% by weight (th. Value: 5.2% by weight); Brookfield viscosity at 70 ° C: 1400 mPa.s
• NCO adduct (4) In a three-necked flask equipped with a stirrer, thermometer and drying tube, 749.28 g of the above-mentioned NCO adduct (4) are heated to 70 ° C. with stirring and then tert with 0.5 g of 2.6 di. butyl-4-methylphenol added. After five minutes, 50.72 g of hydroxypropyl acrylate are added. The mixture is allowed to react at 70-75 ° C for three hours and is then bottled. NCO value of the end product: 1.9% by weight (theoretical value: 2.0%); Brookfield viscosity at 70 ° C: 7000 mPa.s PU prepolymer (6):
• NCO value of the end product 5.83% by weight; Monomer content: 0.1% by weight MDI; Brookfield viscosity at 50 ° C: 7600 mPa.s The undistilled part contains 8.9% by weight MDI, NCO value: 8.19% by weight, Brookfield viscosity at 50 ° C: 5700 mPa.s.
• NCO value of the end product 3.95% by weight (theoretical value: 4.14%), monomer content: 0.06% by weight MDI, Brookfield viscosity at 70 ° C: 2400 mPa.s.
• NCO value of the end product 5.45% by weight (theoretical value: 5.78%), monomer content: 4.3% by weight of MDI, Brookfield viscosity at 70 ° C: 1900 mPa.s. PU PrepoIvmer (7):
• NCO value of the end product 12.50% by weight; Monomer content: ⁇ 0.5% by weight HDI; Brookfield viscosity at 20 ° C: 5300 mPa.s The undistilled part contains 4.9 GW% HDI, NCO value: 14.32% by weight, Brookfield viscosity at 20 ° C: 4900 mPa.s.
• Reactive adhesive (1) 1-component reactive adhesive based on PU prepolymer (1)
• Reactive adhesive (2) 1-component reactive adhesive based on PU prepolymer (2)
• Reactive adhesive (3) 1-component reactive adhesive based on PU prepolymer (3)
• Reactive adhesive (4) 2-component reactive adhesive based on PU prepolymer (4)
• Reactive adhesive (5) 1-component reactive adhesive based on PU prepolymer (5)
• Reactive adhesive (6) 2-component reactive adhesive based on PU prepolymer (5)
• 3J9 g of a polyether polyol with a viscosity of 4380 m.Pas (20 ° C.), an OH number of 391 and a silicon content of 4.9% by weight are used as hardener (D).
• the monomeric polyisocyanate (a) in the polyurethane prepolymer (A) and in the reactive adhesives according to the invention was determined by means of gel permeation chromatography (GPC) or
• HPLC High performance liquid chromatography
• Polyester film (PET film) with a film thickness of 12 micrometers
• PE film made of polyethylene (PE film) with a film thickness of 17 micrometers
• Oriented polyamide (PA) film with a film thickness of 15 micrometers. It was always laminated first and then irradiated.
• the bond adhesion and the seal seam adhesion are measured with a Zwick Z2.5 tensile testing machine on 15 mm wide strips. (Test speed: 100 mm / min.)
• VH stands for composite liability
• SNH seal seam adhesion
• the samples were analyzed by liquid chromatography after derivatization for the degradation product of HDI (1,6-diaminohexane).
• the reactive adhesive systems according to the invention are migration-free after only one day.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Polyurethanes Or Polyureas (AREA)

Applications Claiming Priority (5)

Publications (1)

Family

ID=26007465

Family Applications (1)

Country Status (11)

Cited By (2)

Families Citing this family (49)

Family Cites Families (9)

• 2001
  • 2001-10-13 EP EP01988752A patent/EP1328603A1/de not_active Withdrawn
  • 2001-10-13 JP JP2002537832A patent/JP4399159B2/ja not_active Expired - Fee Related
  • 2001-10-13 PL PL01362645A patent/PL362645A1/xx unknown
  • 2001-10-13 BR BRPI0114826-5A patent/BR0114826B1/pt not_active IP Right Cessation
  • 2001-10-13 HU HU0301437A patent/HUP0301437A3/hu unknown
  • 2001-10-13 MX MXPA03003287A patent/MXPA03003287A/es unknown
  • 2001-10-13 CA CA2426554A patent/CA2426554C/en not_active Expired - Fee Related
  • 2001-10-13 US US10/415,009 patent/US20040084138A1/en not_active Abandoned
  • 2001-10-13 WO PCT/EP2001/011856 patent/WO2002034858A1/de active Application Filing
  • 2001-10-13 AU AU2002221673A patent/AU2002221673A1/en not_active Abandoned
• 2003
  • 2003-04-15 NO NO20031760A patent/NO20031760L/no unknown

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events