WO2011110482A1

WO2011110482A1 - Use of an adhesive composition which can be activated for producing collapsible box blanks

Info

Publication number: WO2011110482A1
Application number: PCT/EP2011/053265
Authority: WO
Inventors: Dieter Urban; Karl-Heinz Schumacher; Stefan Kirsch; Uta Holzenkamp
Original assignee: Basf Se
Priority date: 2010-03-08
Filing date: 2011-03-04
Publication date: 2011-09-15

Abstract

The invention relates to the use of an adhesive composition which can be activated for producing a collapsible box blank, said collapsible box blanks with the adhesive composition applied thereto being resistant to blocking at 25°C. Said adhesive composition has, at a temperature of less than or equal to 25°C, an Ig G'-value of more than or equal to 6 and at a temperature of more than or equal to 120°C, an Ig G'-value of less than or equal to 4 and contains a copolymer having a glass transition temperature of more than 30°C. Said copolymer is made of first monomer and of more than 3 wt. % and less than 40 wt.% of a second monomer. The first monomer is selected from alkyl(meth)acrylates and vinyl aromates and the second monomer is selected from ethylenically unsaturated monomers with acidic groups and hydroxyalkyl(meth)acrylates.

Description

Use of an activatable adhesive composition for making carton blanks

description

The invention relates to the use of an activatable adhesive composition containing certain (meth) acrylate or vinylaromatic copolymers containing acid or hydroxy groups for the production of folding carton blanks, which are blockable at 25 ° C. with the adhesive composition applied thereto and the energy-activated production of folding cartons from corresponding folding carton blanks ,

Folding carton blanks are industrially prefabricated blanks that are supplied to the processing companies in a space-saving, folded-together state, where they are erected, filled and sealed into boxes. In many cases, the upright, each opposing parts are connected to each other by gluing and / or the boxes are sealed after filling by gluing. Conventionally, carton blanks to be bonded are unsealed, i. supplied without adhesive to the processing company, e.g. in the form of box type E according to the classification system of the European Carton Makers Association. The blanks are then provided with a hot melt adhesive immediately prior to introduction into the erecting device and glued after erection. There is a risk here that the erecting machines will be adversely affected by glue deposits on the nozzles and tools and that undesired, visible glue marks on the finished packaging may occur even with precise adhesive positioning. What is desired, therefore, is a technology in which it is possible to dispense with an adhesive application in the processing company immediately before the folding carton erection.

In DE 3246325 a process for the production of folding boxes is described, wherein on blanks an unspecified described dispersion coating is applied and a bonding is effected by the action of ultrasound. In WO 2004/076578 a reactivatable adhesive is described, which is reactivated by the action of a radiation energy having a wavelength of 400 nm to 100,000 nm. The radiation energy is generated in particular by NIR radiation, for example a halogen tungsten lamp, and the adhesive contains an NIR-absorbing ingredient. The unspecific, non-directional use of relatively high-energy NIR radiation can lead to an undesirable, large-scale heating of non-sticking packaging parts or the ingredients to be packaged, which increases the possibilities of filling the packages with heat or radiation sensitive. lent ingredients already before or immediately after irradiation impaired and also consumes more energy than is required for the actual bonding.

It was an object of the present invention to provide for folding carton production a technology which is as energy-efficient and time-efficient as possible, in which it is possible to dispense with an adhesive application in the processing company immediately before the folding carton installation. Ideally, the technology should additionally allow the gluing or gluing closing of cartons already filled with heat- or radiation-sensitive ingredients or to be filled immediately after the gluing.

The invention relates to the use of an activatable adhesive composition for the production of folding box blanks. The carton blanks have surface areas to which the activatable adhesive composition is applied and are block resistant at 25 ° C. The adhesive composition has an IgG 'value of greater than or equal to 6.0 at or equal to 25 ° C and at greater than or equal to 120 ° C an IgG' value of less than or equal to 4.0, containing at least one copolymer with a glass transition temperature of greater than 30 ° C, wherein the copolymer of at least a first monomer and more than 3 wt.% And less than 40 wt.%, Based on the total amount of monomers, at least one other of the first monomer second Monomer is formed, wherein the first monomer is selected from the group consisting of alkyl acrylates, alkyl methacrylates and vinyl aromatics and the second monomer is selected from the group consisting of ethylenically unsaturated monomers having acid groups, hydroxyalkyl acrylates and hydroxyalkyl methacrylates.

The invention also provides the folding carton blanks produced according to the invention, the use of folded carton blanks for the energy-activated production of folding cartons and folding cartons produced according to this use.

The invention also provides a process for the production of folding cartons, wherein

(1) flat carton blanks are provided,

(2) an activatable on at least parts of the flat folding carton blanks

Adhesive composition is applied,

(3) the flat carton blanks are erected into a carton and

(4) before, during or after the erection of the folding box blanks, the adhesive composition is activated by the action of energy, thereby causing gluing of the folded box, wherein the adhesive composition

• has an Ig G 'value equal to or greater than 6.0 at less than or equal to 25 ° C and greater than or equal to 120 ° C an Ig G' value less than or equal to 4.0, and

• contains at least one copolymer with a glass transition temperature greater than 30 ° C, and

The copolymer of at least one first monomer and more than

3% by weight and less than 40% by weight, based on the total amount of monomers, of at least one second monomer other than the first monomer, wherein the first monomer is selected from the group consisting of alkyl acrylates, alkyl methacrylates and vinyl aromatics and the second Monomer is selected from the group consisting of ethylenically unsaturated monomers with acid groups, hydroxyalkyl acrylates and hydroxyalkyl methacrylates. The term "activatable adhesive composition" means that the adhesive composition or folding box with adhesive composition applied thereto at room temperature (25 ° C) and without energetic action (eg electromagnetic radiation) are not or only slightly adhesive that the Faltschachtelzuschnitte that in the As a rule, they are made of cardboard, they are block-resistant, and the adhesive composition becomes adhesive upon energetic action.

The term adhesive composition includes the adhesive agents and optional additives and solvents. Block-proof within the meaning of the application means that when lifting a single blank from a stack of several blanks no further blank adheres. In the stack, a pressure of up to 2 g / mm ² can occur.

The terms "energy-activated", "activated by the action of energy" or "energetic action" mean the action of energy in the form of radiation or ultrasound, in particular in the form of electromagnetic radiation Electromagnetic radiation can be, for example, IR radiation having a wavelength of 0.4 to 1000 μηι, NIR radiation of a wavelength of 0.4 to 100 μηη, microwave radiation of a wavelength of 1 mm to 1 m or radio waves of a wavelength of 1 m to 10 km.

The adhesive composition has a temperature-dependent tack profile. At room temperature (25 ° C) the composition is not or only slightly adhesive. At temperatures above room temperature, the composition is adhesive. Unless otherwise stated, physical parameters and properties refer to ratios at room temperature (25 ° C) and for the range of conventional relative humidity (30-90%). Preferably, at less than or equal to 25 ° C, the adhesive composition has an Ig G 'greater than or equal to 6.0, preferably from 6.0 to 8.0, and at temperatures greater than or equal to 120 ° C, an Ig G' smaller or equal to 4.0, preferably from 2.5 to 3.9, measured by means of a deformation-controlled rheometer with parallel-plate geometry (diameter 8 mm, sample thickness 0.9-1, 2 mm) or torsion -Rectangular geometry (sample width 6 mm, sample length 21 mm, sample thickness 0.9-1, 2 mm). The dynamic shear modulus G ^' is measured at a measurement frequency of 1 Hz with the torsion-rectangular geometry at 25 ° C and with the parallel-plate geometry at 120 ° C. From the adhesives are cast for the measurements films, which are dried to constant weight.

The IgG 'values of the invention can be adjusted by the monomer composition of the adhesive polymers or by addition of plasticizer. If the adhesive composition does not already have the Ig G 'values owing to the monomer composition of the polymers, the Ig G' values can be adjusted according to the invention by addition of the plasticizers described in more detail below

The adhesive composition may be a fusible solid composition, a polymer solution or a polymer dispersion (before application to the blanks and optionally drying). Preference is given to aqueous polymer solutions and aqueous polymer dispersions. Preferably, at least one polymer is contained, which has a glass transition temperature Tg of greater than 30 ° C, preferably greater than 35 ° C or greater than 40 ° C. The glass transition temperature can be determined by conventional methods such as differential scanning calorimetry (see, e.g.

ASTM 3418/82, so called "midpoint temperature"). In the case of aqueous polymer dispersions, the dispersion preferably contains solids contents of from 15 to 75% by weight, preferably from 40 to 75% by weight. In one embodiment, the adhesive composition contains at least 40 weight percent dispersed polymer.

For the purposes of the invention, copolymers are understood as meaning polymers of two or more different monomers. In the following, the term (meth) acrylate and similar terms are used as a shorthand notation for "acrylate or methacrylate".

The copolymers used in the adhesive composition can be obtained by radical polymerization of ethylenically unsaturated compounds. The copolymers preferably comprise at least 10% by weight or at least 20% by weight, or at least 40% by weight, more preferably at least 60% by weight, of the first monomers, which are preferably selected from C ₁ to C ₂ 0 alkyl (meth) acrylates and vinyl aromatics having up to 20 carbon atoms. The alkyl (meth) acrylate monomers are preferably selected from C ₁ -C 20 -alkyl (meth) acrylates, in particular C ₁ to C 10 -alkyl acrylates and C 1 to C 10 -alkyl methacrylates, or C 1 to C ₈ -alkyl (meth) acrylates. Suitable monomers are, for example, methyl methacrylate, methyl acrylate, n-butyl acrylate, ethyl acrylate, n-hexyl acrylate, octyl acrylate and 2-ethylhexyl acrylate. In particular, mixtures of (meth) acrylic acid alkyl esters are also suitable. Suitable vinylaromatics are vinyltoluene, α- and p-methylstyrene, α-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and preferably styrene. In one embodiment, the copolymers according to the invention contain styrene in amounts of from 10 to 60% by weight, preferably 20-50% by weight. The polymer to be used according to the invention is moreover composed of more than 3% by weight and up to 40% by weight, based on the total amount of monomers, of monomers which are selected from ethylenically unsaturated monomers having acid groups, hydroxyalkyl acrylates and hydroxyalkyl methacrylates. Monomers having acid groups are, in particular, ethylenically unsaturated compounds which have at least one carboxylic acid, sulfonic acid or phosphonic acid group. Preferred are carboxylic acid groups. Examples which may be mentioned are acrylic acid, methacrylic acid, itaconic acid, maleic acid or fumaric acid. The acid groups may be in the form of their salts. Preferred hydroxyalkyl (meth) acrylates are the C ₂ to C ₁₂ hydroxyalkyl (meth) acrylates and in particular the C ₂ to C ₆ or the C ₂ to C ₄ hydroxyalkyl (meth) acrylates. Very particular preference is given to hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate or hydroxybutyl methacrylate. The content of acid or hydroxy monomers in the copolymer can be, for example, 4 to 15% by weight in the case of aqueous dispersions, or in the case of aqueous solutions of up to 40% by weight, for example 24 to 40% by weight, based on the polymer be.

In addition to the major monomers, the polymer may contain other monomers, e.g. Vinyl esters of carboxylic acids containing up to 20 carbon atoms, ethylenically unsaturated nitriles, vinyl halides, vinyl ethers of alcohols containing 1 to 10 carbon atoms, aliphatic hydrocarbons having 2 to 8 carbon atoms and one or two double bonds or mixtures of these monomers. Vinyl esters of carboxylic acids having 1 to 20 carbon atoms are e.g. Vinyl laurate, vinyl stearate, vinyl propionate, vinyl versatate and vinyl acetate. Examples of nitriles are acrylonitrile and methacrylonitrile. The vinyl halides are ethylenically unsaturated compounds substituted with chlorine, fluorine or bromine, preferably vinyl chloride and vinylidene chloride. As vinyl ethers, there are e.g. Vinyl methyl ether or vinyl isobutyl ether. Preference is given to vinyl ethers of alcohols containing from 1 to 4 carbon atoms. Suitable hydrocarbons having 4 to 8 C atoms and two olefinic double bonds are e.g. Butadiene, isoprene and chloroprene. Hydrocarbons having 2 to 4 carbon atoms are e.g. Ethylene, propylene or butene.

Further monomers are, for example, also (meth) acrylamides, phenyloxyethylglycol mono- (meth) acrylate, glycidyl (meth) acrylate, aminoalkyl (meth) acrylates, such as, for example, 2-aminoethyl (Meth) acrylate. Alkyl groups preferably have from 1 to 20 carbon atoms. Other monomers which may also be mentioned are crosslinking monomers. The other monomers are generally used in minor amounts, their proportion is generally less than 10 wt.%, In particular less than 5 wt.%.

The ratio of the monomers to each other is preferably adjusted so that the glass transition temperature of the polymer is greater than 30 ° C, or greater than 35 ° C or greater than 40 ° C. The preparation of the radically polymerized polymers can be carried out by emulsion polymerization known per se. In the emulsion polymerization, ionic and / or nonionic emulsifiers and / or protective colloids or stabilizers are used as surface-active substances and also suitable initiators and optionally molecular weight regulators. The emulsion polymerization is generally carried out at 30 to 130 ° C, preferably at 50 to 90 ° C. The polymerization medium may consist of water only, as well as of mixtures of water and thus miscible liquids such as methanol. Preferably, only water is used. In the polymerization, e.g. For better adjustment of the particle size, a polymer seed can be provided. In the emulsion polymerization, aqueous dispersions of the polymer are generally obtained with solids contents of 15 to 75 wt .-%, preferably from 40 to 75 wt .-%. Dispersions with the highest possible solids content are preferred. In one embodiment, the dispersion or adhesive composition contains at least 60% by weight of dispersed polymer. In order to achieve solids contents> 60 wt .-%, one should set a bimodal or polymodal particle size, otherwise the viscosity is too high and the dispersion is no longer manageable. The generation of a new generation of particles can be carried out, for example, by adding seed, by adding excess emulsifier amounts or by adding miniemulsions. The generation of one or more new particle generations can take place at any time. It depends on the particle size distribution desired for a low viscosity. The polymer thus prepared is used in the form of its aqueous dispersion. The size distribution of the dispersion particles may be monomodal, bimodal or multimodal. In the case of a monomodal particle size distribution, the average particle size of the polymer particles dispersed in the aqueous dispersion is preferably less than 400 nm, in particular less than 200 nm. More preferably, the average particle size is between 140 and

200 nm. By average particle size is meant here the d ₅₀ value of the particle size distribution, ie 50% by weight of the total mass of all particles have a smaller particle diameter than the d ₅₀ value. The particle size distribution can be determined in a known manner with the analytical ultracentrifuge (W. Mächtie, Makromolekulare Chemie 185 (1984), page 1025-1039). For bi- or multimodal particle size distribution, the particle size can be up to 1000 nm. The pH The value of the polymer dispersion is preferably adjusted to pH greater than 4.5, in particular to a pH of between 5 and 8.

The adhesive composition preferably contains at least one electromagnetic radiation, in particular microwave radiation absorbing material. This substance is preferably non-adhesive or tacky by itself and is preferably contained in an amount of from 2 to 30, especially from 5 to 15,% by weight, based on the total composition. Electromagnetic radiation or microwave radiation absorbing in the context of the invention is a substance when it absorbs energy when irradiated with electromagnetic waves, thereby heating and emits the absorbed energy as heat to the environment. The electromagnetic radiation absorbing material is e.g. selected from the group consisting of carbon black, graphite, organic color pigments and mixtures thereof.

The adhesive composition preferably contains at least one plasticizer. The plasticizers are preferably contained in an amount of from 5 to 50, in particular from 5 to 35,% by weight, based on the total composition. Examples of plasticizers are phthalic acid esters, trimellitic acid esters, acyclic dicarboxylic acid esters, polymeric plasticizers, phosphoric acid esters, fatty acid esters, hydroxycarboxylic esters, epoxy plasticizers, polyamide plasticizers and polyalkylene glycols. Phthalic acid esters and trimellitic acid esters are, for example, the esters of phthalic acid, isophthalic acid or mellitic acid with C 1 -C 10 -alkanols, for example di-n-octyl phthalate, di-n-nonyl phthalate, di-n-decyl phthalate, diisodecyl phthalate, di-n-octyl isophthalate, Di-n-nonyl isophthalate, diisononyl phthalate, di-n-decyl isophthalate, di (2-ethylhexyl) phthalate, di-n-butyl phthalate, diisobutyl phthalate, dicyclohexyl phthalate, dimethyl phthalate, diethyl phthalate, tris (2-ethylhexyl) tri- laurate. mellitate. Acyclic dicarboxylic acid esters are for example the diesters of dicarboxylic acids with alkanols, especially the diesters of C ₄ to C ₀ dicarboxylic acids with C1 to Ci ₀ - alkanols, for example the diesters of adipic acid, decanedioic acid, glutaric acid,

Succinic acid, for example dimethyl adipate, diethyl adipate, di-butyl adipate, di-isobutyl adipate, glutaric acid di-ethyl glutarate, di-n-butyl glutarate, diisobutyl glutarate, dimethyl succinate, succinic acid succinate, di-succinic di-suberate, diisobutyl succinate and mixtures of the above-mentioned compounds , Polymeric plasticizers are, for example, the polyesters of dicarboxylic acids and alkanediols, in particular C ₄ to C _{1 0} dicarboxylic acids and C ₂ to C ₁ ₀ diols with molecular weights M r of from 1800 to 13 000, for example polyesters of adipic acid, decanedioic acid, azelaic acid or phthalic acid with diols, such as butane-1 , 3-diol, propane-1, 2-diol, butane-1, 4-diol, hexane-1, 6-diol and others. Phosphorus esters are, for example, phosphoric acid compounds which are at least monosubstituted by alkanol, for example C ₁ -C 10 -alkyl-di-C ₆ -C ₄ -aryl phosphates. Examples are isodecyldiphenyl phosphate, tricresyl phosphate, triphenyl phosphate, diphenylketone sylphosphate, diphenylacetylphosphate, tris (2-ethylhexyl) phosphate, tris (2-butoxyethyl phosphate, hydroxycarboxylic acid esters are, for example, citric acid esters such as tributyl O-acetyl citrate and corresponding tartaric and lactic acid esters.

Particularly preferred plasticizers are polyalkylene glycols, especially polyethylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol copolymers, in particular the block copolymers, and polypropylene glycols etherified with two different alcohols. Suitable polyalkylene glycols are especially those with egg nem molecular weight of 100 to 2000. Suitable plasticizers are polyethylene glycols, which are commercially available under the brand name Puriol ^® E. Preferably, at least one polyethylene glycol is present, in particular having a molecular weight of from 100 to 2000. The polyethylene glycols are preferably present in an amount of from 5 to 35, in particular from 10 to 30,% by weight, based on the total composition.

The adhesive composition may contain a tackifier (tackifying resins). Tackifiers are for example from Adhesive Age, July 1987, page 19-23 or Polym. Mater. Be. Closely. 61 (1989), pages 588-592. Tackifiers are, for example, natural resins, such as rosin resins and their derivatives formed by disproportionation or isomerization, polymerization, dimerization, hydrogenation. These may be present in their salt form (with, for example, monovalent or polyvalent counterions (cations) or preferably in their esterified form.) Alcohols used for the esterification may be monohydric or polyhydric, for example methanol, ethanediol, diethylene glycol, triethylene glycol Furthermore, hydrocarbon resins, for example cumarone-indene resins, polyterpene resins, hydrocarbon resins based on unsaturated C-H compounds, such as butadiene, pentene, methylbutene, isoprene, piperylene, divinylmethane, pentadiene, are also found. Cyclopentene, cyclopentadiene, cyclohexadiene, styrene, α-methylstyrene, vinyltoluene are also increasingly being used as tackifiers.Also polyacrylates which have a low molecular weight are used.Preferably these polyacrylates have a weight-average molecular weight M _{w of} less than 30 000. The polyacrylates are preferably at least 60 , in particular at least

80 wt .-% of Ci-C ₈ alkyl (meth) acrylates. Preferred tackifiers are natural or chemically modified rosin resins. Rosin resins consist predominantly of abietic acid or abietic acid derivatives. The tackifiers can be added in a simple manner to the polymer dispersion. The tackifiers are preferably themselves in the form of an aqueous dispersion. The amount by weight of the tackifiers is preferably 5 to 50 parts by weight, more preferably 10 to

30 parts by weight. based on 100 parts by weight of polymer (solid / solid).

The adhesive composition may consist solely of the polymer or of the aqueous dispersion of the polymer, but it may also contain the abovementioned additives. and other additives such as fillers, dyes, flow control agents, thickeners, preferably associative thickeners, defoamers, pigments or wetting agents. For a better wetting of surfaces, the adhesive compositions may in particular wetting aids, for. For example, fatty alcohol ethoxylates, Alkylphenolethoxylate, Nonylphenolethoxylate, polyoxyethylene / -propylenes or sodium dodecylsulfonate included. The amount of additives is generally 0.01 to 5 parts by weight, in particular 0.1 to 3 parts by weight per 100 parts by weight of polymer (solid). The carton blanks may be of a suitable material for producing cartons. Suitable materials are eg cardboard, cardboard, corrugated cardboard or plastic. The surface may be paper-coated, laminated with films, coated with plastic, printed with ink, primed or painted. The surface of the blanks can be coated eg with PP, OPP, PVC, PE or with waxes. The thickness of the blank material is preferably 0.5 to 10 mm.

The adhesive composition can be applied to the folding box blanks by conventional application or coating methods, for example by means of a size press, film press, blade coater, air brush, doctor blade, curtain coating or spray coater. In a preferred embodiment, the application is effected by means of a printing application technique, eg flexographic printing, offset printing or screen printing. Preferred is flexographic printing. After the printed adhesive coating has dried, it is so block-resistant that the printed flat folding-box blanks can be stacked without sticking to one another. In particular, the printed adhesive is blockable so that a stack of the printed with the adhesive sheet blanks, which are usually cartons, can be stored under a weight of 2 tm ^{2 for} up to one year without adhering to each other when separating the individual boxes. In one embodiment, the adhesive composition is applied to the intended for the blanks, not yet cut raw material and then carried out the production of the blanks, for example by punching or cutting.

The blanks may be completely or partially coated with the adhesive composition. Preferably, the adhesive composition is applied only in those limited areas that are actually bonded. The applied amount (wet) is preferably 10 to 300 g / m ² . The layer thickness of the applied, dried adhesive is preferably from 5 to 200 μηη. To produce the folding boxes from the folding carton blanks provided with the adhesive composition, it is possible to use erecting machines known therefor, which are preferably modified in such a way that they have at least at least one source of electromagnetic radiation, eg have a built-in microwave generator or that they allow the irradiation of the blanks with an external radiation source. The adhesive-activating radiation may be done before the surfaces to be bonded are brought into contact with each other, or preferably while the surfaces are brought into contact. In general, this is done with a suitable for a permanent fixed connection high contact pressure. The time of radiation activation of the adhesive layer in the straightening machine is preferably less than 2 seconds, less than 1 second or less than 0.5 seconds. The adhesive layer becomes so sticky within the activation time that secure bonding of the folding carton takes place in the erecting machine, optionally with subsequent or simultaneous application of a contact pressure. The bonding is considered sufficiently safe, if in the case of glued boxes, the bond can be solved only with complete fiber breakage. When bonded in the straightening machine, the adhesive layer applied to a first portion of the surface of the blank may be adhered either to an adhesive layer applied to a second portion of the surface of the blank or to an adhesive-free portion of the blank. The adhesive-free area can also be printed, primed or painted on the spot to be bonded.

The activation of the adhesive layer is preferably carried out with electromagnetic radiation, in particular microwave radiation of a wavelength in the range 1 mm to 1 m, preferably from 5 mm to 0.5 m.

Radiation sources are e.g. IR lamps, lasers, radio wave or microwave generators. A preferred radiation source is a microwave concentrator with which microwaves can be focused, locally concentrated for local treatment of a workpiece and / or made usable for exciting plasma. An arrangement for the concentration of microwave energy in a local area of action is described, for example, in DE 10 2006 034084. Another device for producing microwaves for the treatment of workpieces is described in WO 00/75955. A portable microwave oven for local applications is described in JP 08-019620.

In one embodiment of the invention, the packages are filled before, immediately after or simultaneously with the energetically activated bonding with the ingredients to be packaged. It is particularly advantageous if the ingredients to be packaged are sensitive to heat or radiation and a microwave concentrator is used as the radiation source. The adhesive activation can then be done in a very short time and locally limited, without heat or radiation sensitive ingredients of the packaging are affected. Sensitive ingredients are, for example, chocolate, ice cream, fat or waxy products, pharmaceuticals, cosmetics and similar products.

In one embodiment of the invention, the adhesive composition contains from 20 to 70% by weight, preferably from 30 to 50% by weight of at least one copolymer formed from at least one first monomer and from more than 3% by weight and less than 40% by weight. %, based on the total amount of monomers, of at least one second monomer other than the first monomer, wherein the first monomer is selected from the group consisting of alkyl acrylates, alkyl methacrylates and vinyl aromatics and the second monomer is selected from the group consisting of ethylenically unsaturated monomers with Acid groups, hydroxyalkyl acrylates and hydroxyalkyl methacrylates, from 2 to 30 wt.%, Preferably from 5 to 15 wt.% Of at least one electromagnetic radiation absorbing substance and

from 5 to 40% by weight, preferably from 10 to 35% by weight of at least one plasticizer.

Examples of Microwave Activatable Adhesive Compositions

The following abbreviations are used:

MMA: methyl methacrylate

S: styrene

BA: butyl acrylate

AS: acrylic acid

MAS: methacrylic acid

aMS: alpha-methylstyrene

Pluriol: polyethylene glycol

The Ig G 'values were measured as described above.

In each case, 20 g / m ² adhesive was applied firmly to two cardboard strips and then the two strips of adhesive layer against adhesive layer under a pressure of 15 g / cm ² superimposed and activated with the microwave so that in the adhesive layer for half a second Temperature of 120 ° C resulted. Thereafter, the bond was allowed to cool to room temperature before the strength of the bond was evaluated.

The bonding properties were evaluated by separating the bonded cardboard test pieces at the bonding site by pulling by hand.

"+" Means: severe separation at the bonding site under cardboard fiber breakage "-" means: Easy separation at the bonding site without fiber breakage

The blocking resistance was evaluated by a test in which, under a weight of 2 g / mm ² , the adhesive-coated and dried paperboard was stored against a ^second coated paperboard at 40 ° C for 3 days. The two adhesive layers were placed against each other.

"+" Means: After storage, the boxes could be separated without blocking each other.

"-" means: Adherence of the adhesive layers (blocking) after storage.

The following polymers are used (amount in parts by weight):

Adhesive compositions, dispersed or dissolved in water (in parts by weight):

Menger

Pluriol® ig G 'ig G' VerBlock¬

Polymer polymer carbon black

E 200 (25 ° C) (120 ° C) Bonding strength

Polymer 1 70 5 30 6.2 3.2 + +

Polymer 2 70 10 30 7, 1 3,7 + +

Polymer 3 70 10 30 6.8 3.4 + +

Polymer 4 90 10 10 7.2 2.3 + +

Comparative Examples

Polymer 5 80 10 20 7.2 4, 1 - +

Polymer 4 100 10 - 6.2 4.2 +

Polymer 6 90 10 10 5.2 3.0 + -

Claims

claims

Use of an activatable adhesive composition for making carton blanks having surface areas to which the activatable adhesive composition is applied, wherein

The folding carton blanks with adhesive composition applied thereto are block-resistant at 25 ° C., and

The adhesive composition has an IgG 'value of greater than or equal to 6.0 at less than or equal to 25 ° C. and an IgG' value of less than or equal to 4.0 at greater than or equal to 120 ° C., and

The copolymer is formed from at least one first monomer and from more than 3% by weight and less than 40% by weight, based on the total amount of monomers, of at least one second monomer other than the first monomer, wherein the first monomer is selected from the group consisting of alkyl acrylates, alkyl methacrylates and vinylaromatics and the second monomer is selected from the group consisting of ethylenically unsaturated monomers having acid groups, hydroxyalkyl acrylates and hydroxyalkyl methacrylates.

Use according to claim 1, characterized in that the adhesive composition additionally contains at least one non-adhesive, electromagnetic radiation absorbing substance.

Use according to claim 2, characterized in that the electromagnetic radiation absorbing material is selected from the group consisting of carbon black, graphite, organic color pigments and mixtures thereof.

Use according to one of the preceding claims, characterized in that the adhesive composition additionally contains at least one plasticizer.

Use according to the preceding claim, characterized in that the plasticizer is a polyalkylene glycol.

Use according to the preceding claim, characterized in that the plasticizer is a polyethylene glycol.

Use according to one of the preceding claims, characterized in that the adhesive composition a) contains 20 to 70% by weight of at least one copolymer formed from at least one first monomer and from more than 3% by weight and less than 40% by weight, based on the total amount of monomers, of at least one second of the first monomer A monomer, wherein the first monomer is selected from the group consisting of alkyl acrylates, alkyl methacrylates and vinyl aromatics and the second monomer is selected from the group consisting of ethylenically unsaturated monomers having acid groups, hydroxyalkyl acrylates and hydroxyalkyl methacrylates

b) from 2 to 30% by weight of at least one electromagnetic radiation absorbing substance and

c) contains from 5 to 35 wt.% Of at least one plasticizer.

8. Use according to one of the preceding claims, characterized in that the Faltschachtelzuschnitt has areas on which the activatable adhesive composition is printed in a layer thickness of 5 to 200 μηη.

9. Use according to one of the preceding claims, characterized in that the vinylaromatics of the first monomer of the copolymer are styrene or alkylstyrene. 10. Faltschachtelzuschnitt, prepared by using an activatable adhesive composition according to any one of claims 1 to 8.

1 1. Use of a folding box blank according to claim 9 for the energy-activated production of folding cartons.

12. Use according to the preceding claim, characterized in that the activation of the adhesive composition is effected by electromagnetic radiation.

Use according to the preceding claim, characterized in that the activation of the adhesive composition takes place in a period of less than 2 seconds by microwave radiation of a wavelength of 1 mm to 1 m. 14. Use according to the preceding claim, characterized in that the activation of the adhesive composition by means of a microwave concentrator takes place. Folding box produced by using a folding box blank according to claim 10.

Process for the production of folding cartons, wherein

(1) flat carton blanks are provided,

(2) an activatable adhesive composition is applied to at least parts of the flat folding carton blanks,

(3) the flat carton blanks are erected into a carton and

(4) before, during or after the erection of the carton blanks the adhesive composition is activated by the action of energy and the gluing of the carton is effected

Method according to one of the preceding method claims, characterized in that the adhesive composition additionally contains at least one plasticizer.

Method according to one of the preceding method claims, characterized in that the adhesive composition additionally contains at least one non-adhesive, electromagnetic radiation absorbing substance.

19. Method according to one of the preceding method claims, characterized in that the adhesive composition a) contains 20 to 70% by weight of at least one copolymer formed from at least one first monomer and from more than 3% by weight and less than 40% by weight, based on the total amount of monomers, of at least one second of the first monomer Monomer, wherein the first monomer is selected from the group consisting of alkyl acrylates, alkyl methacrylates and vinyl aromatics and the second monomer is selected from the group consisting of ethylenically unsaturated monomers having acid groups, hydroxyalkyl acrylates and hydroxyalkyl methacrylates;

b) from 2 to 30% by weight of at least one electromagnetic radiation absorbing substance; and

c) contains from 5 to 35 wt.% Of at least one plasticizer.

Method according to one of the preceding method claims, characterized in that the adhesive composition is printed on at least partial areas of the folding box blanks in a layer thickness of 5-200 μm.

Method according to one of the preceding Verfahrensansprüche, characterized in that the activation takes place in a period of less than 2 seconds by microwave radiation of a wavelength of 1 mm to 1 m.

Method according to one of the preceding method claims, characterized in that the microwave activation takes place by means of a microwave concentrator.

23. The method according to any one of the preceding method claims, characterized in that the folding box is filled before or immediately after the activation of the adhesive composition with ingredients to be packaged.