EP1904596A1

EP1904596A1 - Perfumed melt adhesive

Info

Publication number: EP1904596A1
Application number: EP06761930A
Authority: EP
Inventors: Erik Niehaus; Petra Padurschel; Marcel Roth; Gunter Hoffmann; Rolf Tenhaef; Georg Meine; Andreas Bauer
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2005-06-30
Filing date: 2006-05-20
Publication date: 2008-04-02
Also published as: WO2007057059A1; DE102005030431A1; MX2007015636A; BRPI0612816A2; US20080132625A1; RU2008102798A

Abstract

The invention relates to a melt adhesive which is used stick packagings and which consists of 10 - 75 wt.% of a polymer which is based on melt adhesives, 10 - 70 wt.% of an adhesive resin, 0 - 50 wt.% of a wax and/or a plasticizer, 0 - 15 wt.% of additives and 0,01 - 10 wt.% of at least one perfume. Said packaging is stuck by means of the melt adhesive. When the packaging is torn, the adhesive surfaces are exposed and the perfume is released. The invention also relates to a method for the continuous production of melt adhesives containing perfume.

Description

"Hot melt adhesive with fragrances"

The invention relates to a hot melt adhesive containing fragrances. In particular, hot melt adhesives are to be provided, the packaging materials stick together and release a fragrance when the adhesive surface is exposed, in particular even at low temperatures. Furthermore, the invention relates to a method for producing these hot melt adhesives, wherein the thermal stress is kept low by the production.

Hot melt adhesives are well known. These serve u.a. to that

Packaging of food, eg. As paper packaging, cans or

Container to be glued. Furthermore, hot melt adhesives are known which also bond textile fabrics or fibrous materials together.

Hot melt adhesives containing fragrances are already known. They are described, for example, in WO 03/048264. There are described hot melt adhesives containing fragrant materials with a flash point> 100 ⁰ F. These are prepared by stirring hot melt adhesives with a corresponding fragrance. Protective measures during training are not required. Use is described for use in diapers or other sanitary articles.

Food and other consumer items are often packaged in rupturable packaging, such as paper or plastic. Foods often have a characteristic odor, other items should smell pleasant. In order to give the buyer a positive sense of the content at the time of purchase or opening the packaging, it is possible to use volatile fragrances in the packaging. An introduction into the food is usually undesirable. An application but on the entire surface of the packaging leads already during storage to a loss of fragrances.

One way to fix fragrances is therefore to add adhesive substances, such as hot melt adhesives, with fragrances and apply these targeted to the packaging. In this case, fragrances are then released at these points. Thus, any packaging or other items can be provided with slowly released fragrances. Hot melt adhesives for the food industry must meet special requirements. Furthermore, they must meet optical requirements, d. H. the adhesives should be substantially clear or white in color.

Furthermore, it is necessary, especially when adding fragrances that are volatile at low temperature, to take appropriate measures during production in order to avoid an odor nuisance. This may be pure odor nuisance, but this can also lead to health hazards, eg. B. lead allergies. In addition, it must be avoided that polymers or fragrances decompose due to the thermal stress. This problem is to be considered especially in the production, because there the corresponding raw materials are processed in increased concentration or increased amounts.

It is therefore an object of the present invention to provide a hot melt adhesive which permits a targeted release of fragrances / flavorings. This should arise during the exposure of the adhesive surface of the substrates, which can happen even at low temperatures. Another object of the invention is to provide a method in which such fragrances can be incorporated gently into hot melt adhesives.

The object is achieved by a hotmelt adhesive based on 10-75% by weight of a hot melt adhesive base polymer, 10-70% by weight of a tackifying resin, 0-50% by weight of a plasticizer and / or wax, 0-15% by weight. Additives and 0.01-10% by weight of at least one perfume with a cLogP- Value between 1, 0 and 20. The sum of the components should be 100%.

Another object of the invention is a process for the preparation of hot melt adhesives according to the invention by continuous production in an extruder, wherein the fragrance is preferably incorporated in a late process stage. Another object of the invention is a bonded with such a hot melt adhesive package that exposes the adhesive surface when opening, thereby releasing the fragrance.

Under the hot melt adhesive base polymers thermoplastic synthetic polymers are understood that essentially determine properties important for hot melt adhesives, such as adhesion, strength and temperature behavior. Examples of such polymers are polyamide resins, copolyamides, polyetheramides, polyesteramides, polyesters, polyethers, polycarbonates; thermoplastic elastomers; reactive and non-reactive linear or branched thermoplastic polyurethanes; Polymers such as ethylene-vinyl acetate, ethylene, ethylene / acrylate, propylene / hexene, SIS, SBS, SEBS copolymers; Polyolefins, such as amorphous polyolefins, semi-crystalline polyolefins, in particular propylene or ethylene homopolymers or copolymers.

The hotmelt adhesive in the compositions according to the invention contains at least one base polymer having a molecular weight of 2,000-200,000 g / mol. Molecular weight data are intended to indicate the number average molecular weight as obtainable by gel permeation chromatography. Such polymers are already known to the person skilled in the art. Polymers based on propylene-styrene and / or ethylene-styrene copolymers, acrylate copolymers, ethylene-vinyl acetate copolymers, amorphous polypropylenes or other semicrystalline olefin copolymers are preferably used in the hotmelt adhesives according to the invention.

Suitable base polymers for use in hot melt adhesives are polyacrylates. Such polyacrylates are obtainable, for example, by polymerization or copolymerization of ethylenically unsaturated Carboxylic acid esters, such as acrylic acid, methacrylic acid, crotonic acid or maleic acid esters. Preference is given to polymerizing customary C 1 to C ₁₅ -alkyl esters of (meth) acrylic acid. It may also contain OH-containing monomers. Such monomers are obtainable, for example, by the esterification of ethylenically unsaturated carboxylic acids and difunctional alcohols. Corresponding OH-unsaturated esters are, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate or mixtures thereof. Functionalized or unfunctionalized polymers can be obtained. Possibly. For example, ethylene can also be copolymerized. Such binders are commercially available.

Furthermore, known ethylene-vinyl acetate copolymers (EVA) can also be selected as base polymers. Preparation and composition of such EVA, optionally with further comonomers, are known to the person skilled in the art, for example under the trade names Alcudia EVA or Escorene.

In a preferred embodiment, atactic poly-α-olefins are selected as the base polymer. These may for example have a molecular weight of more than 4000 g / mol up to 200000 g / mol and consist of the monomers ethylene, propylene and / or further comonomers, such as styrene derivatives, diolefins or C ₄ - C ₂ O α-olefins, in particular also terpolymers suitable. Such largely amorphous poly-α-olefin (APAO) may carry functional groups on conventional substrates to improve the adhesion, in which case comonomers having functional groups are used, for example acrylic acid, maleic acid or vinyl acetate. These functional groups can be introduced either by copolymerization with small amounts of functional monomers or preferably by subsequent radical reaction of APAOs with such functional monomers. Such functionalized monomers are usually incorporated in amounts of 0.1 to 10 wt .-%. The softening temperatures of the substantially amorphous poly-α-olefins are usually about 100 ⁰ C (+ ring and ball method according to ASTM E 28). Such APAOs are known to those skilled in the art and suitable polymers or mixtures thereof can be used to be selected. They are available, for example, under the trade name Vestoplast.

In addition, proportionally largely crystalline poly-α-olefins can also be used. The degree of crystallization is usually> 55% (determination by differential calorimetry DSC). The largely crystalline poly-α-olefins can be prepared using Ziegler-Natta catalysts as isotactic polymers. In general, polyethylene, polypropylene, polybutylene or polystyrene or copolymers are used, preferably isotactic polypropylene copolymers having a molecular weight of more than 5000 g / mol are used.

A particularly preferred embodiment of the present invention works with polyolefins prepared by metallocene catalysis as a base polymer. This is to substantially linear copolymers of at least .Two monomers based on ethylene and / or propylene with optionally a further C ₄ - C ₂ 0 α-olefin comonomers, said copolymer having an Mn of 2,000 - 100,000 g / mol and a density between 0.85-0.96 g / cm ³ . They may be atactic, isotactic or syndiotactic polymers. Preference is given to copolymers which contain a propylene content of more than 80 mol% or an ethylene content of more than 75 mol%. It is also possible to modify these polymers, for example as described above, by grafting with functional monomers, by oxidation or by copolymerizing monomers containing aromatic groups. Particularly suitable is a grafting reaction with monomers containing aromatic groups, such as styrene or its derivatives.

These preferred polyolefin copolymers have a low polydispersity to Mw: MN <3, especially <2.5. The molecular weight of these polymers should in particular be less than 40,000 g / mol, in particular between 3,000 and 25,000 g / mol. It is also possible to use mixtures of polymers of different molecular weight. Such polymers are commercially available, for example under the trade name Licocene or Affinity. The choice of the base polymers is easily possible for the person skilled in the art. The polymers are known with their properties and can be selected depending on the application, eg spray application, for thermally sensitive substrates, fast setting times, special substrate adhesion. It can be used a single base polymer, but it can also be used mixtures of preferably two or more polymers. The amount should be based on the hot melt adhesive 10 to 75 wt.%, Preferably 20 to 65 wt.%.

As a further component, the hot-melt adhesive according to the invention contains at least one tackifying resin. The resin causes additional tackiness and improves the compatibility of the hot melt adhesive components. These are in particular resins which have a softening point of 70 to 150 ° C. These are, for example, aromatic, aliphatic or cycloaliphatic hydrocarbon resins, as well as modified or hydrogenated versions thereof. Examples include aliphatic or alicyclic petroleum hydrocarbon resins and hydrogenated derivatives. Further resins which can be used in the context of the invention are rosin and derivatives, such as rosin esters, in particular esters thereof with pentaerythritol or glycerol; preferably modified natural resins such as gum rosin resin, tall resin or wood rosin, e.g. fully saponified gum rosin or alkyl esters of optionally partially hydrogenated rosin with low softening points; Terpene resins, in particular copolymers of terpene, such as styrene-terpenes, α-methyl-styrene-terpenes, phenol-modified terpene resins and hydrogenated derivatives thereof; Acrylic acid copolymers, preferably styrene-acrylic acid copolymers and reaction products based on functional hydrocarbon resins. It is preferable to use hydrogenated hydrocarbon resins or rosin esters individually or in a mixture.

The tackifying resin has a lower molecular weight of below 3000 g / mol, in particular below 1500 g / mol. It may not be chemically reactive or it may optionally also contain functional groups, such as OH groups, carboxyl groups or double bonds. The amount of the resin is usually between 10 to 70% by weight, preferably between 10 to 50% by weight.

Optionally, waxes can be added to the hotmelt adhesive in amounts of from 0 to 50% by weight, preferably from 5 to about 30% by weight. These can also influence the viscosity of the hotmelt adhesive. The amount is dimensioned so that on the one hand, the viscosity is lowered to the desired range, on the other hand, the adhesion is not adversely affected. The wax may be natural, possibly also in chemically modified form, or of synthetic origin. Vegetable waxes, animal waxes or petrochemical waxes can be used as natural waxes. Hard waxes such as montan ester waxes, sasol waxes, mineral waxes, etc. can be used as the chemically modified waxes. As synthetic waxes find polyalkylene waxes and polyethylene glycol waxes use. Preferably, petrochemical waxes such as petrolatum, paraffin waxes, microcrystalline waxes and synthetic waxes are used, in particular polyethylene waxes having a molecular weight of 500-2000 g / mol, paraffin waxes, microcrystalline waxes or synthetic Fischer-Tropsch waxes, the melting points in the range of 50 to 140 ^0th C have.

Another component of the hotmelt adhesive according to the invention may be plasticizers. These plasticizers are preferably used for adjusting the viscosity or the flexibility, and are generally contained in a concentration of 0-25% by weight, preferably 2-15% by weight. Suitable plasticizers are, for example, medicinal white oils, naphthenic mineral oils, polypropylene, polybutene, polyisoprene oligomers, hydrogenated polyisoprene and / or polybutadiene oligomers, benzoate esters, phthalates, adipates, vegetable or animal oils and derivatives thereof. Hydrogenated plasticizers are selected, for example, from the group of paraffinic hydrocarbon oils. Polypropylene glycol, polybutylene glycol or polymethylene glycol are also suitable. Possibly. esters are also used as plasticizers, for. As liquid polyesters and glycerol esters or plasticizers based aromatic dicarboxylic acid ester. Likewise, alkyl monoamines and fatty acids having preferably 8 to 36 carbon atoms may be suitable.

Other additives can be incorporated in amounts of up to 15 wt .-% in the hot melt adhesive to vary certain properties. These may be, for example, dyes, pigments or fillers, such as titanium dioxide, talc, clay, chalk and the like. It may also be, for example, stabilizers or adhesion promoters.

The purpose of the stabilizers is to protect the adhesive composition from degradation during processing. Here are in particular the antioxidants to call or light stabilizers. They are usually added in amounts of up to 3 wt .-%, preferably in amounts of about 0.1 to 1, 0 wt .-% of the hot melt adhesive.

In addition, the hot melt adhesive according to the invention may contain adhesion promoters. Adhesion promoters are substances which improve the adhesion of the hotmelt adhesive to the substrate to be bonded. In particular, adhesion promoters should improve the aging behavior of bonds under the influence of humid atmosphere. Typical adhesion promoters are, for example, ethylene / acrylamide comonomers, polymeric isocyanates, reactive organosilicon compounds or phosphorus derivatives. These can also affect the wetting properties of the adhesive and thus the adhesion to the substrates.

The additives, such as pigments, dyes, stabilizers or adhesion promoters are known to the person skilled in the art. They are commercial products and the skilled person can select them according to the desired properties. It is important to ensure that a compatibility with the polymer mixture is given.

The hot-melt adhesive according to the invention must contain at least one fragrance. In this context, fragrances are to be understood as meaning all substances, such as fragrances, fragrances, aroma substances or perfume oils. They may be individual substances, but are usually mixtures of several substances. These together make up the fragrance note. This fragrance can be selected and compiled by a person skilled in the art. According to the invention, it is necessary that the fragrances have a certain polarity. This can be achieved that the fragrance on the one hand can be incorporated storage stable in the hot melt adhesive and does not damage the adhesion to the substrate, but still allows a targeted release to the ambient air. The polarity for fragrances is often given as the n-octanol / water partition coefficient (P). This value represents the distribution ratio in equilibrium concentration of the dissolved fragrance between both phases. The logarithmic values for base 10 (logP) are specified. For many fragrances, these logP values are given in the literature. It is also possible to calculate such values (clogP). Such calculation methods are given, for example, in "Comprehensive Medicinal Chemistry VOL 4, page 295." The values given can be determined experimentally or they can be calculated.These values are collectively referred to here as clogP value The numerical value gives a measure of hydrophilic / hydrophobic Properties of the perfume again.

According to the invention, the clogP value for the suitable fragrances should be between 1.0 and 20, preferably between 1.2 and 10.0, in particular up to about 5.0. Such fragrances are easy to incorporate into the polymers of the hot melt adhesives according to the invention. Furthermore, it is ensured that they are released from an applied adhesive top layer in the surrounding air. Since mixtures of fragrances are generally employed, at least 80% by weight of the proportions of active fragrance, i. without a possible carrier or solvent, have a corresponding clogP value.

Another measure of the characterization of fragrances is through the

Volatility of the odor (substantivity) given, which is also referred to as fragrance.

This classification into fragrances is often described in commercial fragrance components. Fragrances usually comprise three parts of the fragrance, such as top notes, preferably formed of volatiles, which reflect the first fragrance impression; Middle note, which gives a more lasting impression and lasts longer; Base note, which encompasses the long-lasting, less volatile fragrance impressions. According to the invention, the perfume consists for the most part of substances that are attributable to the heart or base note. Long-term adhesive components such as heart or base notes should be present in sufficient quantities, generally more than 50% by weight. By selecting the fragrances with an overwhelming amount of heart or base note and a selected clogP value of the individual fragrances, it is possible to homogeneously incorporate the fragrances into the adhesives according to the invention and to ensure a release over a period of about three hours.

The fragrances may be natural substances, such as essences of fruit parts, parts of plants, essential oils derived therefrom, or they may be synthetic odorants or fragrances. The synthetic products may be identical to natural fragrances, such as vanillin, menthol, eucalyptol, or they may be artificial products. These fragrances can be derivatives of hydrocarbons, heterocycles, alcohols, aldehydes, ketones, acetals, esters, phenols, phenol ethers or thiols. It may be individual compounds, but often mixtures of several substances are necessary. Examples of essential oils are aniseed oil, bitter almond oil, fennel oil, citrus oil, jasmine oil, rose oil, chamomile oil, clove oil, mint oil, cinnamon leaf oil, orange blossom oil, bergamot oil, eucalyptus oil, spruce alder oil, guaiac wood oil, ginger oil, iris oil, cajeput oil, cardamom oil, coriander oil, lavender oil, lime oil, tangerine oil or lemon balm oil; synthetic fragrance compounds include, for example, esters such as benzyl acetate, phenoxyethyl isobutyrate, p-tert-butylcyclohexyl acetate, linalyl acetate, dimethylbenzylcarbinylacetate, phenylethylacetate, linalylbenzoate, benzylformate, ethylmethylphenylglycinate, allylcyclohexylpropionate, styrallylpropionate and benzylsalicylate; Ketones or aldehydes such as 8-18 carbon atoms, citral, citronellal, citronellyloxyacetaldehyde, cyclamen aldehyde, hydroxycitronellal, lilial and bourgeonal; Ketones such as ionone, iso-methyl ionone and methyl cedryl ketone; Hydrocarbons such as limonene, pinene; Alcohols such as cinnamyl alcohol, aniseediol, vanillin, eugenol, thymol, pharnesol, borneol, anethole, citronellol, eugenol, geraniol, linalool, phenylethyl alcohol or ethers, such as benzyl ethyl ether, ambroxan. The listing is not an exhaustive list, but is only intended to show examples of different substance classes.

Lighter volatile fragrances are those fragrances of natural or synthetic origin that cause a rapid odor impression. This may also be in particular low-boiling fragrances, which can be used alone or in mixtures.

The perfume suitable according to the invention must be volatile. In general, the molecular weight is between 100 g / mol to 300 g / mol. In the context of the invention, more volatile fragrances are particularly preferred. The fragrances may be liquid, pasty or solid fragrances.

The fragrances can be used as a pure substance. They can be used as a solution in organic solvents or in water. The solvents used are, for example, alcohols, such as glycerol, ethylene glycol, propylene glycol, diethylene or dipropylene glycol, etc. They can also be used on carrier materials such as waxes, paraffins, etc. It is also possible to incorporate them into cluster compounds, such as cyclodextrin fragrance complexes.

The amount of perfume should be 0.01 to 10 wt .-%, preferably 0.05 to 5 wt .-%, in particular 0.1 to 3 wt .-%. if necessary, inert substances can additionally be added to the fragrance. Nevertheless, these may possibly increase the odor effect of the fragrance. The fragrances according to the invention should preferably be distributed homogeneously in the hotmelt adhesive. The hot-melt adhesive according to the invention should have a viscosity of between 100 and 15,000 mPas at 120 ° C. to 180 ^° C., preferably below 7,500 mPas at up to 150 ° C. (measured with Brookfield RVT, spindle 27 according to EN ISO 2555).

The hot melt adhesives according to the invention may be conventional hot melt adhesives which cause adhesion only on account of the thermoplastic properties. Furthermore, it may also be reactive hot melt adhesives such. B. via hot melt adhesives crosslinking isocyanate groups or it can be permanently tacky hot melt pressure sensitive adhesives. In the case of reactive hot melt adhesives, ensure that the reactive groups of the hot melt adhesive do not react with the fragrances. In the case of pressure-sensitive hot melt adhesives, it is possible to repeatedly bond these adhesive surfaces with the substrate.

The invention further relates to a process for the preparation of hot melt adhesives according to the invention which contain fragrances. In principle, it is also possible to carry out hot melt adhesives according to the invention by mixing the components with heating in a stirred tank. The temperature-sensitive substances, in particular the fragrances according to the invention, should be added to the reduced thermal load as possible at a later time. According to the invention, the process is carried out in a self-contained system, so that possible vaporizing substances can be sucked off.

However, a preferred embodiment relates to a continuous production. In one embodiment, the already mixed hot melt adhesive is added to the extruder. This can be done in solid or even molten form. A further embodiment gives all constituents of the hotmelt adhesive, individually or premixed, in the extruder. Another embodiment first introduces individual components of the hot melt adhesive, such as the base polymer or blend of base polymers, into the extruder and, at a later time, further components, such as the tackifying resin, are added incrementally. When mixing and Melting in the extruder, the mixtures of the polymers are heated, melted and homogenized. The temperature is controlled and limited to a value, so that the polymers and other components are not too much thermally stressed. For example, little or no discoloration of the hotmelt adhesive should be observed in the end product. The temperature is below 180 ⁰ C, generally below 150 ⁰ C, preferably below 120 ⁰ C, in particular below 100 ⁰ C. By mixing and melting in the extruder, a particularly rapid and gentle homogenization of the materials is possible. The temperature in the extruder can be influenced by various measures. For example, it is possible to heat or cool the extruder. Furthermore, the temperature can be influenced or adjusted by the rotational speed of the extruder screws, by the shearing gap or the pitch of the extruder screws and by the molecular weight of the polymers contained in the mixture. If these are introduced as solids, they only melt in the course of the mixing process.

The order of addition may be selected to initially add the high molecular weight solid products which are then melted, and then the lighter melting, low viscosity products are incorporated. A corresponding procedure enhances the plasticizing and the mixing effect of the extruder.

When a homogeneous mixture of the stable hot melt adhesive components is present, the temperature sensitive and low viscosity portions are added to the extruder. These are, for example, plasticizers, waxes, additives, such as antioxidants or adhesion promoters. At this time, the fragrances can be added. It is expedient to limit the processing temperature at this time or possibly lower it beforehand, for example by cooling. For example, processing is possible even at temperatures up to 120 ⁰ C, possibly also some components, eg. As the fragrances, be added at temperatures up to 80 ° C. Due to the mixing and transport properties of the extruder, it is possible to use the To reduce operating temperature in the extruder, compared to other mixing units, and to achieve a shorter mixing time or residence time in the mixing unit. The metered addition of the other components can be done in one stage or in several stages, wherein the perfume is preferably introduced in the last stage at low temperature.

The perfume or fragrances may be in solid or liquid form. They can be added directly to the mixture. Furthermore, the fragrances can also be added if they are present, for example, absorbed on solid support materials. Even such solids are metered into the mixture at this time and are homogenized.

According to the invention it is possible to add one or more fragrances in concentrated form as a finished premix. However, especially at low levels, it is preferred to facilitate dosage of the amounts, to premix the perfumes and optionally their carrier materials in proportions of individual components of the hot melt adhesive, and then to dose. It is necessary that these shares do not react with the perfume mixture. For example, the perfume may be mixed in portions of the plasticizer, e.g. B. in liquid form, dissolved or dispersed, but it is also possible to disperse the fragrance in parts of the wax or the adhesive resin. These mixtures in the form of a masterbatch are then proportionally added, so that overall no change in the composition of the hot melt adhesive occurs. A particular embodiment works with aqueous solutions of the perfume components. Such aqueous solutions can be used in the process according to the invention, even if the working temperature in the mixture is above 100 ^° C., if vaporization of the low water content is avoided by the pressure inside the extruder. Homogeneous mixtures are formed, which release the water content only during degassing of the hotmelt adhesive. It is also possible to set a temperature of the mixture below 100 ^° C. With the procedure according to invention also an at least partial remaining of water shares in the hot melt adhesive can be achieved become. Such adhesives are then particularly suitable to receive polar fragrances and hold in the adhesive. It should be noted that water can be used as a solvent only insofar as it is non-reactive hot melt adhesives. When it comes to reactive hot-melt adhesives, for example isocyanate-reactive, water must be avoided during manufacture.

After complete mixing of the hotmelt adhesive components, the liquid or viscous hotmelt adhesive may be degassed and then discharged from the extruder. This is usually done using a cooling device. This cooling can still be done in the extruder or it happens after discharge from the extruder. This can be caused by cooled gases, eg. As air or carbon dioxide, done, which are directed to the hot melt adhesive. It is also known, the hot melt adhesive to a cooled pad, z. B. discharged a cooled sheet or a cooled belt, or he is preferably in a cold liquid, for. B. discharged water. Likewise, the hot melt adhesive immediately after cooling to a suitable temperature of a granulation or an underwater granulation can be subjected ul. It is also possible to package the hotmelt adhesive directly in, for example, foil bags, to close them and then to cool them. Particularly suitable for the gentle processing of hot melt adhesives is a temperature of the mixture when discharged from the extruder to less than 120 ⁰ C, in particular below 75 ° C.

Devices for mixing the components, metered addition of the components in the extruder and for discharging and filling of the hot melt adhesives are known in the art. These are the usual one or more screw extruders or preferably also twin screw extruders. The dosing devices for the fragrances should in principle not be in direct contact with the working air of the environment. It is preferred if these units are encapsulated or the air can be sucked out there. It is expedient for the procedure according to the invention if the fragrances or fragrance-containing precursors and the hot, fragrance-treated hot melt adhesive is further processed so that no significant amounts of the fragrance evaporate into the work environment. This can be ensured by closed equipment or by suction devices.

In particular, it is preferred that the components of the hotmelt adhesive are homogenized and that the fragrances are added at a later time of the procedure at the lowest possible temperature. This metering can be carried out in a device encapsulated by the environment. Furthermore, it is preferred if the hotmelt adhesives are introduced immediately after extrusion into a closed silicone paper or plastic wrapper and then these are cooled and stored or packaged in a plastic wrapper after granulation.

The use of the hot melt adhesives of the invention is done in a known manner. For example, such hot melt adhesives can be applied to packaging materials. Such materials can be cardboard, corrugated, paper, printed paper, single and multi-layer plastic films, metallized films or printed substrates, plastics, and similar substrates. The application can be carried out by known processes, such as rolling, printing, knife coating, rolling, spraying or jet application, if appropriate also with a slot die. Corresponding substrates or corresponding application devices are known to the person skilled in the art. The application temperature depends on the choice of base polymers. Can vary from about 80 ⁰ C to 180 ⁰ C, preferably below 150 ⁰ C.

In order to avoid fragrance release during storage of the bonded substrates, it is expedient to cover the corresponding perfume-containing adhesive. This can be done by gluing to the second substrate side, but additional cover layers, such as film strips or paper layers, can be provided. After application of the hotmelt adhesive, the packaging is glued directly, ie the two substrate surfaces are brought together, pressed and connected. It should preferably be generated no free to the air or to the content facing hot melt adhesive surfaces.

If a sufficient fragrance effect of the hot melt adhesive according to the invention is present, an adhesive surface may be sufficient with an adhesive according to the invention, i. It is possible to glue more adhesive seams with commercial hot melt adhesives without fragrance. Likewise, if necessary, parallel to the perfume-containing adhesive surfaces such non-scented hot melt adhesives can be applied. Thus, free surfaces of the adhesive surfaces of an adhesive according to the invention can be shielded from the environment. This can reduce odor loss during storage.

An object of the invention is the use of fragrance-containing hot melt adhesives in the packaging of articles and the release of fragrances when tearing the package. When using the hotmelt adhesives according to the invention for bonding packaging, they are applied according to the known application methods. The hot melt adhesive of the invention is covered on both sides by a substrate and connects them. This adhesive surface should be arranged so that the adhesive seam is at least partially exposed when tearing the package. When the package is torn open or a re-sealable package is opened, a cohesive break in the hot-melt adhesive may occur or an adhesive break between the substrate surface and the hot-melt adhesive may be obtained. This rupture creates a large surface of the open hot melt adhesive. From this surface, the present invention in the hot melt adhesive fragrance can be released and immediately form a corresponding odor cloud. If small amounts of water are contained in the hotmelt adhesive, these may lead to reduced adhesion or cohesion. This facilitates the exposure of an adhesive surface. In addition, any water contained may evaporate and release the fragrances reinforced. This can lead to a release of the fragrances contained therein breaking the adhesive surface. It is also possible To bond packaging for foods that are stored at low temperature. When opening the package in the cold state, a corresponding fragrance can be released.

The hot melt adhesives according to the invention have only small proportions of the fragrances. Essentially, they should release an odor cloud only briefly when the appropriate packaging is opened. This should fly away after a short time. By selecting slow-acting fragrances, it is also possible to repeatedly release a cloud of perfume in multi-resealable packaging.

In a further embodiment, it is also possible, in the packaging of insensitive products, to apply an application surface with a fragrance-containing hot melt adhesive according to the invention within the packaging. The packaging is then glued with conventional hot melt adhesives. This makes it possible to achieve a fragrance cloud within the package. When the packaging is first torn open or when the packaging is reopened, when a resealable lid is present, a cloud of scent is released from the packaging volume. The corresponding product, eg. As detergent, can be removed and after sealing builds up again in the packaging again a fragrance cloud. A suitably designed packaging is suitable for goods that are not consumed and are not adversely affected by the contact with the fragrance cloud.

In a further embodiment, the hotmelt adhesive according to the invention is covered by an additional layer, in which case the hotmelt adhesive can also be applied to the outside of the packaging and then provided with a covering layer, for example a cover film. However, it is also possible to provide this covering with a, for example, pressure sensitive hot melt adhesive and applied in the form of a label on the packaging. If the fragrance note of the adhesive used corresponds to the inherent odor of the packaged product, so can, without opening the packaging, a appropriate fragrance impression to be conveyed to the customer. With a suitable choice of hot melt adhesives, the fragrance releasing adhesive surfaces can be closed again, and repeated removal of the fragrance is released again.

In any case, even after prolonged storage a fragrance effect of the bonded or applied hot melt adhesive is present. Due to the surface of the substrates, only a very small migration of the odorants is given, so that an odor effect is given even after prolonged storage to a sufficient extent. Possibly. For example, a suitable substrate surface may be selected that reduces diffusion into or through the substrate.

By selecting the adhesive for a product, it is possible to select the fragrance component to match the product. In this case, the adhesive according to the invention is applied so that it releases the fragrance when the package is opened. But it can also be applied to a free side of the package and thereby be provided with an additional cover layer.

It is e.g. ensure food fragrances are selected that are not harmful to the packaged product and that are separated by a substrate side itself, e.g. B. by a foil to be kept away from the product; It can also be an outer packaging glued to the adhesive of the invention. When used for cosmetics or consumer goods, such as detergents, care must be taken that no health hazards, such as allergic reactions, are caused by the fragrance.

It is also possible to provide articles with olfactory marks by applying a fragrance containing hot melt. The perfume is then not tailored to the product, but should give a recognizable hint as a brand. Also in this case, the above-described compositions and usual application methods can be used. The procedure according to the invention makes it possible to glue, for example, food or consumer goods packaging, which causes the consumer a pleasant or food-typical odor when opened. Furthermore, it is possible, for example, to bond cosmetic packaging with such hot melt adhesives according to the invention. In this case, a matched to the application perfume can be added to the hot melt adhesive. The hotmelt adhesive according to the invention is used in particular for bonding packaging in the consumer goods industry, the food industry or the cosmetics industry.

By selecting the fragrances with suitable clogP values it can be ensured that the fragrance can be stably incorporated into the hot melt adhesive and migration into the substrate surface is reduced. Exudation to the surface of the adhesive bead is reduced and thus the adhesion to the substrate is not adversely affected. The production method according to the invention makes it possible to produce the products easily, with the exclusion or reduction of possible nuisance in the incorporation and handling of the perfume components. Continuous production using an extruder allows for lower processing temperatures and faster homogenization with shorter residence times. Therefore, the adhesive components and especially the

Fragrances exposed to only low temperature loads, so that the compounds are not thermally destroyed or only slightly loaded. The only small free outwardly facing surfaces of inventively produced and bonded packaging prevent premature distribution of the scent cloud during storage. In particular, in resealable packaging no fragrance components can diffuse into the environment even when re-closed. By exposing a large surface, the fragrance present according to the invention is released. The selection of the fragrances allows a reconciliation and assignment of fragrance and aroma cloud with special packaged products. The following examples show working methods according to the invention.

Fragrance mixture D1 clogP

3 parts musk anthranilate 2.2

10 parts heliotropin 1.65

4 parts of anisaldehyde 1, 67

6 parts of di-hydro-β-ionone 4,48

11 parts Aldehyde C09 (10%) 3.27

12 parts octalactone delta 1, 59

9 parts ethylvanillin 1, 55

13 parts ethylmaltol 1, 59

5 parts Linalool 2.85

8 parts Patschuly 83-2970 2.0

7 parts Vanillin 1, 4 to 100 with di-propylene glycol

Perfume mixture D2

30 parts vanilla dream 1, 7

22 parts of ethyl vanillin 1, 55

10 parts Benzoin siam 1,2

10 parts vanillin 1.4 to 100 with di-propylene glycol

Perfume mixture D3

0.2 part of perfume mixture 2

0.5 parts Plantacare 1200 (APG)

5.3 parts of water

Mix on the dissolver to form a stable emulsion.

Hot melt adhesive M1

Hot melt adhesive M2

Example 1 :

The olefin copolymer and the tackifier resin according to M1 are in a

Twin-screw extruder (Brabender) introduced and melted with heating and mixed. The two paraffin waxes are then metered in and homogenized in the extruder. The temperature is adjusted to 130 ⁰ C and then added 0.1 parts of D 1 and incorporated. The mixture is degassed, cooled to 120 ⁰ C and discharged from the extruder.

The adhesive is poured into silicon-lined molds and allowed to cool. The result is a solid at room temperature hot melt adhesive.

Example 2:

The hot melt adhesive according to M1 is produced. She will join afterwards

Room temperature in a twin-screw extruder introduced together with

0.2 parts D 2, mixed and melted. The mixture is degassed, adjusted to about 60 ⁰ C and discharged from the extruder.

The adhesive is discharged as a strand, cooled with air and then granulated.

The result is a solid at room temperature hot melt adhesive.

Example 3:

The hot melt adhesive according to M2 is produced. It is then heated and introduced at 80 ° C in a twin-screw extruder and homogenized. There are 5 parts of D3 added at about 80-90 ⁰ C and mixed. The mixture discharged from the extruder.

The adhesive is discharged as a strand, cooled with air and then granulated.

The result is a solid at room temperature hot melt adhesive. Example 4:

Copolymer and hydrocarbon resin according to M2 are in a

Twin-screw extruder (Brabender) introduced and melted with heating and mixed. Paraffin wax, plasticizer and additive are then metered in and homogenized in the extruder. Then 0.5 parts of D2 are added and incorporated. The mixture is discharged from the extruder at 100 ^° C.

Example 5:

The mixture of the individual binder components according to M2 is in a

Twin-screw extruder (Brabender) introduced, mixed and melted. Then the stabilizer is added and the D2 as

Premix added in an amount of 0.1 parts with 0.5 parts of ethanol and homogenized. The temperature is maintained at about 70 ⁰ C, the mixture is degassed and discharged from the extruder.

Bonding + Test 1:

Two paper substrates are bonded in each case with the hot melt adhesive according to Example 1 to 5, wherein the adhesive surface is about 2 cm ^{2 in} size. The scent is sticky

Substrate barely or not perceptible.

After 24 hours the glued area is torn open. The result is an exposed adhesive surface that spreads immediately a scent cloud.

Similarly, PE films, PET films, PP films, metallized PE films, metallized paper, cardboard are bonded as a substrate. There is hardly a fragrance perceptible. If the bond breaks at room temperature, a well-perceived scent cloud is formed. Bonding + test 2:

Two PET film substrates are bonded to the hot melt adhesive according to Example 2, wherein the adhesive surface is about 2 cm ^{2 in} size. The scent is sticky

Substrate barely or not perceptible. The bonded substrates are stored at 0 ⁰ C.

After 24 hours the glued area is torn open. The result is an exposed adhesive surface that spreads immediately a cloud of perfume.

Claims

claims

1. hot melt adhesive for bonding packaging material containing a) 10 to 75 wt.% Of at least one adhesive base polymer b) 10 to 70 wt.% Of at least one tackifying resin c) 0 to 50 wt.% Of at least one wax and / or plasticizer d) 0-15% by weight of additives e) 0.01-10% by weight of at least one perfume having a clogP value of between 1.0 and 20, the sum being 100%.

2. Hot melt adhesive according to claim 1, characterized in that the base polymer of polyolefin (co) polymers, ethylene-vinyl acetate (co) polymers, polyurethanes, polyesters and / or polyamides is selected.

3. hot melt adhesive according to claim 1 or 2, characterized in that the viscosity between 100 to 15,000 mPas at 120 to 180 ⁰ C and the base polymer has a molecular weight of 2000 to 200000 g / mol.

4. hot melt adhesive according to one of claims 1 to 3, characterized in that the perfume has a clogP value between 1, 2 to 10 and a molecular weight of less than 300 g / mol.

5. hot melt adhesive according to one of claims 1 to 4, characterized in that the perfume is selected from aromatic or aliphatic esters, aromatic or aliphatic alcohols, aromatic or aliphatic ketones or aldehydes and / or aliphatic or aromatic ethers.

6. hot melt adhesive according to one of claims 1 to 5 containing a) 10 to 65 wt.% Of at least one linear copolymer of ethylene and / or propylene with optionally at least one C ₄ - C 20 α-olefin comonomer, where i) the Copolymer has a M _n of 2000 to 100000 and ii) has a density between 0.85 to 0.96 g / cm ³ , b) 10 to 50 wt.% Of a tackifier resin, c) 0 to 30 wt.% Of a plasticizer and / or waxes, d) 0-15% by weight of additives and e) 0.05-5% by weight of a perfume which predominantly has a heart and / or base note.

7. hot melt adhesive according to claim 6, characterized in that the copolymer of propylene with at least one further C2 or C4 - C2 ₀ α-olefin and is prepared by metallocene catalysis.

8. hot melt adhesive according to claim 7, characterized in that the copolymer has a molecular weight of 3000 - 25000 g / mol having a dispersity Mw: MN <3.

9. A process for the continuous production of a fragrance-containing hot melt adhesive, characterized in that in an extruder a) in a first stage, the hot melt adhesive or the adhesive components are mixed and melted, wherein the temperature of the melt is maintained below 180 ⁰ C, b) in a further stage at least one liquid or solid fragrance is added and homogenized, c) and the product is cooled and bottled.

10. The method according to claim 9, characterized in that a) in a first stage, the base polymer and the tackifying resin are mixed, b) in a second stage or optionally in further stages plasticizer, wax and additives are added and homogenized, wherein the mixture is maintained at a temperature below 180 ⁰ C, c) incorporated in a final stage of the fragrance, which alone, as a mixture with a proportion of a component of the hot melt adhesive or mixed with a solvent added, and d) the product if necessary Degassed, cooled and bottled.

11. The method according to claim 10, characterized in that the temperature of the mixture in the extruder prior to the addition of the fragrances below 120 ⁰ C.

12. The method according to claim 10 or 11, characterized in that the perfume is incorporated in a homogeneous mixture with portions of a plasticizer or a wax.

13. The method according to claim 10 or 11, characterized in that the fragrance is dissolved in aqueous solution or emulsion or in organic solvents, incorporated.

14. The method according to claim 13, characterized in that the pressure in the extruder during homogenization is so great that no vapor bubbles occur at the processing temperature.

15. The method according to any one of claims 9 to 14, characterized in that the addition of the fragrance is carried out in a system encapsulated by the environment, so that only small amounts of the fragrance escape into the environment.

16. The method according to any one of claims 9 to 15, characterized in that the extruder is a twin-screw extruder.

17. Use of a hotmelt adhesive according to one of claims 1 to 8 for the production of packaging.

18. Use according to claim 17, characterized in that when opening the package, an adhesive surface is exposed and thereby the fragrance is released.

19. Use according to claim 18, characterized in that the packaging is resealable on the adhesive surface.

20. Use according to claim 18 or 19, characterized in that in addition an adhesive without fragrances is used.

21. Use according to claim 17, characterized in that the hot melt adhesive is applied to an outer side of the package and is glued to a cover layer.

22. Use according to claim 17, characterized in that the hotmelt adhesive is applied to the inner surface of the packaging.

23. Use according to one of claims 17 to 22 for packaging in the consumer goods, food or cosmetics industry.

24. Use according to claim 23 for the preparation of a package for goods that are stored at low temperature.