WO2005028124A1

WO2005028124A1 - Method for surface modification of coated substrates

Info

Publication number: WO2005028124A1
Application number: PCT/EP2004/009615
Authority: WO
Inventors: Matthias Koch; Kerstin Motzkat
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 2003-09-08
Filing date: 2004-08-28
Publication date: 2005-03-31
Also published as: DE10341670A1

Abstract

A method for coating a substrate, wherein the substrate is provided with a coating agent; the non-hardened or cross-linked coating agent is brought into contact with a film wherein additives are placed on the side of the film facing the coating; the additives merge into the coating, whereupon the coating agent is hardened or cross-linked, and the film is subsequently removed from the surface of the coating.

Description

"Process for surface modification of coated substrates

The invention is in the field of modification of surfaces coated with coating compositions, in particular for the finishing of coated surfaces with special functional properties such as scratch resistance, dirt repellency, optical appearance, structuring, antiseptic or biocidal action, an additive being applied to the surface of the coating composition and this then crosslinked or cured after the modification. _

The coating of metallic or non-metallic objects is widespread. The surfaces are often pretreated, on the one hand to achieve decorative effects, and on the other hand to maintain certain product properties. Colorless or colored coating agents are used as coatings, which contribute significantly to the properties of the product. Colored lacquers can have a decorative effect, colorless lacquers plastically emphasize the surface, lacquers with certain admixtures produce special properties, e.g. biocidal properties, adhesion properties or corrosion protection. The service life of the substrates for the respective purpose is significantly increased.

The admixtures are usually introduced by simply mixing the active substance with the coating agent. Methods are also known for specifically influencing the surface by applying the admixture, for example by spraying. The strength or duration of the desired effect can generally be influenced by the amount of the admixture. From DE 101 18 345 surfaces and methods for producing the same are known in which the surface of a substrate is coated with an uncured one Coating is provided as an adhesive, coupling agent or varnish, and a finely divided, preferably hydrophobic powder is sprayed and pressed onto this surface, and the coating is then cured. After crosslinking, unnecessary, non-embedded powder is removed.

From DE 42 19 446 a method is known in which a decorative coating is applied to a possibly already coated substrate, in which a plastic film is coated with a non-crosslinked decorative material, which is brought onto the substrate and through the decorative layer Radiation is crosslinked, and then the plastic film is removed again from the now coated surface, either immediately or later after the transport, the crosslinked decorative material remaining on the substrate surface. The disturbances of the crosslinking reaction by oxygen should be avoided.

EP 0576419 describes thermoplastic films which are transferred to the roughened thermoplastic film via a carrier film with pigment particles dispersed in the binder by heat.

A method and the coated substrates are known from DE 101 44 531, in which a metal surface is provided with a coating agent, this is covered with a film and then the lacquer layer is crosslinked by means of radiation! The coating agent can optionally contain various admixtures in order to achieve special properties. After the coating has crosslinked, the film can be removed.

The above-mentioned procedure by adding an admixture to a coating agent has the disadvantage that if one wishes to change certain properties of the coating by adding additives, a higher amount of the additive in the entire coating agent is required in order to achieve a sufficient effect on the surface. An otherwise appropriate addition to the underside of the coating can also cause problems, for example bad ones Liability to be a cause. One way to get an increased concentration of the additive on the surface is to create a concentration gradient. In the case of mixtures, an enrichment on the surface only takes place if the physical parameters of the admixture and the coating agent cause the homogeneous coating to separate. Such segregation effects are difficult to control. Another possibility is a multiple coating with layers of different compositions, the additive being present in a higher concentration in the outer layer. This procedure is very complex to carry out.

The object of the invention is therefore to provide a method for finishing non-crosslinked coated surfaces, in which a predetermined amount of an additive is introduced into the upper layer of the coating, this composite is then hardened, and thereby a permanent modification of the surface is achieved with the desired properties.

The object is achieved by a method in which a coating agent is applied to a substrate, which is coated in a not or not completely cured or crosslinked state with a carrier film which is coated with at least one additive on the side of the surface facing the coating , and then the coating agent is crosslinked, the carrier film being removed from the substrate immediately or at a later time after the crosslinking.

Another embodiment of the invention relates to a method in which the additive has a concentration gradient from the coating surface into the interior of the coating. Another embodiment relates to a method in which the additive is introduced in a form such that a slow release of an active substance from the additive to the coating surface takes place and a permanent effect is achieved with volatile additives. Another embodiment relates to a method in which the coating is treated with an embossing film with the additive and the surface is thus additionally processed spatially.

Another embodiment relates to a method in which the additive which gives the surface special properties is in powder form.

The invention also relates to substrates which are provided with a surface coating modified by the process.

The method according to the invention can be carried out on different substrates. These are provided with a coating in a known manner. The coating agent used can be solid, pasty or liquid. It is essential to the invention, however, that the coating is not or not fully cured or assumes a viscous state of aggregation before or during the application of the film. A film is then applied to the coating. This is previously coated with the additive on the side facing the coating. This additive should only adhere to the film so that a substantial part of the additive can be transferred to the surface of the coating. The film should be applied without bubbles to ensure that the entire surface of the substrate is evenly brought into contact with the additive. After the film has been applied, the coating composition is cured in a known manner. This can involve physical and / or chemical hardening processes. For example, curing can take place physically by cooling, or chemical crosslinking can be achieved thermally or by radiation. After crosslinking, the film is removed from the substrate immediately or later.

Through the contact of the additive with the uncured or uncrosslinked coating agent, the additive is transferred and a high concentration of the additive is obtained on the surface. Depending on the choice of additive, penetration of the additive into deeper areas of the coating can be determined. It a concentration gradient is formed. This can be done by migration or diffusion of parts of the additive, but the solid can also be enclosed by the coating agent. If solid powdery additives are used, these can optionally also be dissolved or suspended in the coating agent and diffuse into the coating, but it is also possible that parts of the powder are pressed deeper into the coating due to the mechanical load when the film is applied, and so on a concentration gradient is formed. As the concentration of a substance on or near the surface is important for many properties, a fully functional modified coated substrate is obtained in this way.

The method according to the invention is suitable for various substrates. The substrate can consist of metallic materials, but it can also consist of plastics or natural materials. In particular, metals and their alloys, such as ferrous materials, such as steel; Light metals such as aluminum, magnesium, titanium; Non-ferrous metals such as copper, zinc; Tin precious metals such as platinum, gold, silver; Plastics, such as polyurethane, polycarbonate, polyester; Wood materials such as MDF boards, wood, mineral surfaces such as glass or ceramics are suitable. Metallic substrates are particularly preferred. The surface of the substrates can be pretreated or already provided with one or more coatings. The substrate can have any shape, but is preferably in the form of plates, sheets or strips. The surface of the substrates is coated with a coating agent.

Before coating, the substrate should be essentially free of dust and grease; if necessary, it is subjected to cleaning or pretreatment. Various coating agents known per se, which can be hardened or preferably chemically crosslinked, can be applied as coating agents in the process according to the invention. However, they should generally be solvent-free when the film is applied, ie only contain small amounts from the manufacturing process or the application process of the coating agent. Preferred examples of such coatings are coating compositions which can be crosslinked thermally or by radiation. It can be 1-component or multi-component coating agent. The coating compositions can be liquid or, if appropriate, also in powder form. After application to the substrate, they form a homogeneous coating; if necessary, they are heated and can flow. Partial gelation can also take place, but the coating layer must not yet be completely crosslinked. An additional embodiment uses non-crosslinking coating agents that can be applied and flowed when hot, that physically cure at ambient temperature. Such coating compositions are also known to the person skilled in the art.

The binders of the coating compositions can be based on polyurethanes, polyesters, PVDF resins, polyacrylates or epoxy resins. The crosslinking can be carried out by free-radical or ionic polymerization of polymers containing double bonds, it can be carried out by reaction of reactive groups such as amine and isocyanate groups, it can be carried out by splitting off blocking protective groups, e.g. of blocked isocyanate groups.

In particular, however, they are coating compositions which crosslink according to a radical and / or cationic reaction mechanism. Such coating compositions are widely known in the literature and have been described for various purposes. It can be clear lacquer layers or pigmented systems. Liquid or powder coating agents can be applied. The coating compositions can contain initiators. Thermal polymerization can be carried out using suitable initiators. In the process according to the invention, however, coating agents are preferred which contain photoinitiators and can be crosslinked by actinic radiation.

Such systems - in the case of systems which harden by the free radical mechanism - consist, for example, of at least one polymer, prepolymer or having free-radically polymerizable unsaturated groups Oligomers, reactive thinners or monomeric components, as well as from auxiliaries customary in paint. These can be leveling agents, solvents, adhesion promoters, thixotropic and anti-settling agents, pigments or dyes, and in particular polymerization initiators. In particular, prepolymers based on (meth) acrylate resins, optionally with other comonomers, have been found to be suitable. The initiators can be activated thermally or are photoinitiators. Examples of suitable coating systems curing by polymerization are described in DE-A 199 56 659, DE-A-199 25 631, US 59 87 727, WO 2001091926 or EP 0783534.

If it is a matter of cationic systems, such formulations consist, for example, of at least one polymer, prepolymer, oligomer or a monomeric component which has an oxirane group, and the auxiliaries and additives customary in lacquer listed above.

In the case of hybrid systems, these are mixtures that harden according to both radical and cationic mechanisms.

The coating compositions to be applied in the process according to the invention can be selected with a view to their later use. If the coated substrates are deformed, flexible coating layers are preferably favorable after crosslinking. The layers can be colorless to keep the substrate visible, but they can also be colored by dyes or pigments.

The coating compositions can be applied in a known manner. Such processes are, for example, the spray systems commonly used in painting technology, such as airless, air-assisted or electrostratically assisted spray processes. The coating agent is preferably applied to a flat workpiece or metal strip surface by flooding / squeezing, spraying / squeezing, suitable scraper or roller applications, for example in a roll coater. Such processes are known and are used in the coil coating process or similar processes for the surface finishing of Metal strips or metal plates are used and can be adapted depending on the specified system.

The coating composition according to the invention is generally applied at temperatures between 10 and 150 ° C., but preferably at 15 ° and 75 ° C. A smooth, closed surface is to be obtained, and the flow of powder coatings, for example, can be supported by elevated temperature. The coating layer can later be crosslinked thermally, in which case coating compositions with reactive chemically crosslinking functional groups are used, the coating is preferably crosslinked by actinic radiation, such as UV radiation, electron radiation or γ radiation. The electron radiation should have energy values between 50 and 500 keV. Crosslinking by UV radiation is preferred, in particular with a wavelength of 150 to 800 nm, particularly preferably between 200 and 450 nm. Corresponding radiation sources are known to the person skilled in the art. The radiation intensity and the duration of the radiation depend on the process conditions, e.g. Radiation source distance or relative movement between source and substrate. However, the duration is generally less than 60 seconds, preferably between 0.001 and 30 seconds. The respective plant parameters can be determined by a person skilled in the art by adaptation. However, the crosslinking should not be carried out immediately after the application, but only after the application of a film coated with the additive to the coated surface.

The layer thickness of the coating to be cured is 0.1 to 500 μm, preferably up to 100 μm, particularly preferably between 0.5 to 50 μm.

According to the invention, a carrier material, e.g. B. applied a carrier film which is coated with at least one additive. This film should be tear-resistant. It is resistant to the ingredients of the coating agent. The film should be stable under the crosslinking conditions and should not react with the coating agent. You should not additive permanently tie. Examples of such materials are e.g. B. silicon-coated polymer films. In the case of thermal crosslinking, the film should be stable at the necessary crosslinking temperatures; in the case of crosslinking by radiation, a film which is permeable to the high-energy radiation used is applied to the substrate.

A machine application process is preferably carried out, in particular in the case of flat substrates. For example, the tear-resistant film can be pulled off a supply roll, adherently coated with the additive, and applied bubble-free to the substrate surface previously coated with coating agent by means of a roller. The application of the film can be supported by external force, e.g. by pressing with a roller or by applying a vacuum. The parameters must be selected depending on the coating agent, film and substrate. In the case of powdery additives, the pressure can, if necessary, influence how far the additive penetrates into the surface. Embedding in the surface can also be supported by elevated temperature. After this process step, in the case of crosslinkable systems, the coating agent is crosslinked.

The film consists, for example, of polyethylene, polypropylene, PET or mixtures thereof. It can be colored or transparent. It is tear-resistant so that it can be removed from the substrate surface immediately or in a later processing step by peeling it off. This can also be done by the end user, so that the film can additionally serve as protection for the object during further processing and / or transport. The film can be discarded or used again.

Another preferred embodiment applies the additive with a carrier film which is designed as an endless belt. The film surface is cleaned if necessary, then the additive is applied to one side, and then this side of the film is brought into contact with the coated surface. The coating agent is then crosslinked and the film is immediately removed again. Devices for the continuous endless conveying of films or tapes are known to the person skilled in the art.

The surfaces of the crosslinked surface obtained after removal of the carrier material are usually smooth. Another embodiment of the invention uses a film which has an embossed structure on the side for applying the additive. This makes it possible to introduce a spatial structure into the surface in addition to the modification with the additive. Such structures can support a dirt-repellent effect, for example.

The application of the additive to the film surface is known in principle. A flowable substance can be used, for example, by dipping, spraying, knife coating, inkjet method or other casting techniques, e.g. Curtain flow technique. Powdery substances can be applied, for example, by spraying, as a suspension or electrostatically. The additive should only adhere to the surface of the film in such a way that it can be transferred to the coating surface. One additive can be applied, but mixtures of several additives can also be applied. The amount of the substance on the coating surface can be influenced by the amount applied to the film. The . The amount transferred on the surface of the coating also depends on the contact time between the film and the coating agent before curing. The concentration of the additives can be specifically controlled via this parameter.

The contact time of the film with the coating before crosslinking depends on the choice of additive and coating agent. It should be so long that a sufficient amount of the additive is transferred to the surface. The contact should be at least 0.1 seconds before the coating crosslinks, but the time can also be longer, e.g. B. 1 sec. To 10 min. or more. The additive can migrate into the surface, or it is embedded in the surface, and a decreasing concentration gradient can preferably form in the depth of the coating. The gradient is for example, influenced by the viscosity of the additive or the coating agent, the compatibility of the additive / coating agent, the duration of the contact time in the uncrosslinked state and the amount of the additive. During the film / substrate contact time, the coating is cured or crosslinked. The curing or crosslinking is carried out using the methods described above. The concentration gradient that may be formed can still change even after the coating agent has crosslinked. Then the film can be removed again, either immediately, e.g. B. with a circumferential film or only after a long time.

According to the invention, the surfaces can be treated with various additives. The equipment and the selection can be made according to the desired properties of the coating, and several additives can also be combined. Those skilled in the art can select such additives accordingly. According to the invention, additive is understood only to mean those substances which are not coating agents and which on their own do not form any coatings, for example no lacquer or adhesive layers. These are substances which may also be present as a constituent in coating compositions, for example in dispersed or dissolved form. In the method according to the invention, however, they are only transferred via the carrier film. It is also possible that these additives react chemically with components of the coating agent. Such additives are then firmly built into the polymer matrix of the coating. Possibly. it is also possible to mix the additive with a small amount of a substance which can react with the coating agent or which aids in diffusion of the additive into the coating agent. Another procedure introduces a powder as a matrix as an additive, which contains slowly volatile substances or substances that diffuse out of the matrix. Additives that are difficult to tolerate or incompatible can also be incorporated into the coating. Examples of additives are biocidal, biorepulsive, biostatic or antiseptic substances, lubricating substances, adhesion or wetting substances, chemical activity or catalytic substances, surface hardness changing substances, chemical molecule-absorbing substances, pigmenting substances.

In a preferred embodiment, antibacterial or biocidal compounds can be contained in the coating agent. These are, for example, organic substances such as betaines, phenol and phenol derivatives (e.g. 4-chloro-3,5-xylenol, 4,6-dichloro-3,5-xylenol, 2-benzyl-4-chlorophenol, 2,2 '-Methylenbis (4-chlorophenoI), 2-phenylphenol), chlorine or hypochlorite-releasing compounds such as -chloro-4-methylbenzenesulfonamide, Λ /, / V-dichloro-4-methylbenzenesulfonamide and polymeric analogs, 1, 3-dichloro- 5,5-dimethylhydantoin, trichloroisocyanuric acid; iodophors; 3-iodo-2-propynyl butyl carbamate; quaternary ammonium compounds such as Λ / -benzyl- / V, Λ / -dialkyl-alkylammonium halides, benzethonium chloride, and cetylpyridinium chloride; Biguanidines such as chlorhexidine; Alcohols such as famesol, phenylethanol and 2-phenoxyethanol; Aldehydes such as glutaraldehydes; heterocyclic compounds such as methyl isothiazolinone and other isothiazolinone derivatives; polymeric compounds, such as Amina T100 (Degussa) or inorganic substances, such as silver particles. These compounds can migrate into the coating composition during manufacture or are pressed into the surface as a powder. They lead to long-term antibacterial surfaces. In particular, compounds can be used which can slowly diffuse to the surface in the crosslinked film.

Another preferred embodiment is the use of substances that chemically influence the surface. Such substances are, for example, hydrophobizing compounds such as alkyl-, silicone- or perfluoro group-containing substances, hydrophilizing compounds such as substances with a high number of polar groups such as OH, NH, COOH, PO ₃ H, -CH ₂ -O-CH ₂ -. These can be applied to the surface of the coating as a powder or as a liquid. In this case it is preferred if the applied compounds react with functional groups of the coating agent. This means that the surface can be permanently modified. Another preferred embodiment is the use of powders. These can be powders that are inert and modify the coating surface. Examples include nanoscale powders made from aluminum oxide, silicon oxide, zirconium oxide or boron nitride.

According to the invention, however, it is also possible to use powders which have cavities in which other more volatile compounds are incorporated. Such powders are, for example, finely divided zeolites, cyclodextrins and their derivatives. Another embodiment uses other chemical substances or cavity molecules as an additive, such as crown ethers, cucurbiturils, calixarenes, phthalocyanines or other chelating agents. Such voids in powders or molecules form host-guest complexes, e.g. together with fragrance or aroma substances that release the stored substance over a longer period of time. The host substance is selected in accordance with the guest molecule. As a guest molecule, it is also possible to introduce compounds which, as a pure substance, are incompatible with the coating composition or which can lead to undesirable reactions when crosslinked. The powders are to be introduced into the coating so that they are essentially embedded in the binder. A concentration gradient can also be generated here by the pressure and the flowability of the coating agent. The aim is to create a smooth surface that has no structure due to the powder on the surface.

Another preferred embodiment is the use of substances as additives which have a catalytic activity. Such catalytic properties are, for example, radical-forming substances, such as organic metal complexes, biocatalysts, such as enzymes, photocatalysts, such as titanium dioxide. Surfaces can thus be produced which, for example, have a dirt-reducing effect or which have a biocidal effect. Additives can also be applied which have a catalytic effect on the surface of the coating composition. Different chemical reactions with the interior of the coating material can then take place there. Objects according to this invention are distinguished by the fact that they have a customary coating which has been modified on the surface permanently or long-term with chemical substances. They show a better surface quality according to the selected additive and are inexpensive to manufacture. They contain a predefined amount of additives, which are present in higher concentrations, especially on the surface. Simple and fast production processes are possible, in particular for substrates in the form of strips, sheets or plates.

The method according to the invention provides a substrate with a surface coating, the properties of which can be influenced depending on the functional purpose. The person skilled in the art can influence the properties via the selection and amount of the additives. Since the additive is predominantly only on the surface of the coating, the amount of the additive can be reduced compared to the admixture in the entire coating composition. Another advantage of the method according to the invention is that possible problems on the underside of the coating to the substrate, for example disturbed adhesion of the coating, can be avoided by the targeted modification of the surface. A site selectivity, i.e. this method enables additives to be brought to a specific, desired location.

Depending on the choice of additives, it is also possible to incorporate volatile substances, which usually cannot be applied permanently to surfaces, into a coating. In this case, the concentration gradient changes during the life of the object. In such cases, accumulation on the surface avoids long diffusion paths to the surface of the coating. In addition, near-surface cavity molecules can also be reversibly loaded with desired substances during the usual lifespan if the amount of the stored substance has become too small. The following examples are intended to explain the invention.

Example 1 :

A) A 10% solution of AMINA T 100 (Degussa) in ethanol is applied to a 60 μm thick polypropylene film. The solvent then evaporates. A UV-curing coating agent is applied in a roll coater with a layer thickness of approx. 5 μm to a metal sheet and then the film with the AMINA T 100 coated side is applied to the liquid binder layer without bubbles. The composite piece is passed and crosslinked in a UV belt system at a belt speed of approx. 20 m / min under a UV lamp (fusion lamp, 240 W / cm, H lamp). The film is then removed.

The surface is subjected to a test to determine the biofilm reduction. The coated metal sheet is cut into approximately 2.5 x 2.5 cm small plates, sterilized and incubated for 6 hours in 1:20 diluted culture medium, inoculated with P. aeruginosa, at 30 ° C. The metal plates are then dried and colored with Safranin O. Then the safranin O is extracted with DMSO and the absorption of the test sheet at 492 nm is enjoyed. As a result, a 90% reduction based on metal platelets without coating is obtained.

B (comparative test): 1% by weight of AMINA T100 is homogeneously mixed with the UV-crosslinkable coating agent, which is the maximum amount of AMINA T10O that can be dissolved in the coating agent. The coating agent is applied to the sheet with a layer thickness of 5 μm and cured analogously to Example 1A.

The surface is then subjected to the biofilm reduction test. As a result, only a reduction of approx. Obtained 12% based on metal plates without coating. Example 2:

A) A PP film (thickness 60 microns) with a 20% solution of

Perfluoroalkylethyl (meth) acrylate coated in methyl ethyl ketone. The solvent evaporates at room temperature.

A sheet metal substrate is coated with a UV varnish as in Example 1 and the film with the coated side is applied immediately thereafter.

The coating agent is crosslinked as in Example 1 and the film is removed.

The contact angle (circle fitting method) is measured and an angle of 120 ± 2 ° is determined.

B (comparative test): A test is carried out with an analog substrate and a coated and hardened coating agent without modification. The angle measured is 67 + 2 °.

C) The surface from Examples 2A) is 5 min. Stored in MEK and then dried. The contact angle is determined and a value of 120 ± 2 ° is obtained

The experiment shows that the additive has penetrated the surface of the coating agent from the film. There it is also firmly attached to the surface against solvents.

A determination of the F concentration with XPS measurement shows as a gradient a decrease from an initial value on the surface of 37 F atom% to approx. 10.5 F atom% after approx. 100 nm, approx. 6 F atom% in 1000 nm depth and approx. 1.5 F atom% in 1600 nm. Example 3:

A) 1 g of nanoscale aluminum oxide is slurried in 9 g of ethanol and a PP film is coated with this suspension. The solvent can evaporate.

A sheet is coated analogously to Example 1) and coated with the film.

The coating agent is then crosslinked and the film is removed.

The surface hardness is determined using a Erichsen Model 318 hardness test rod and a value of 2.3 N is determined.

A cross section of the substrate shows a decrease in the Al concentration in the

Depth measured using the XPS method.

B (comparative test): A test according to Example 3 A) is carried out, an uncoated film being placed thereon.

After cross-linking the surface, the surface hardness is determined. The surface hardness is significantly lower at 1.5 N.

Example 4:

A film is mirrored in an inkjet printer

Lettering coated with standard color toner.

A sheet is coated according to Example 1A) and the film with the printed

Applied side down.

After networking and removing the film, the correct lettering is on the

Surface applied. It is also against common household organic

Solvents such as acetone, ethanol and mineral spirits are resistant.

Example 5:

An OPP film is charged statically and held over finely powdered heptadecanfluor-1-nonanol powder, the OPP film homogeneously covering itself with a thin layer of the fluoroalcohol. A polyurethane (PUR) formulation is produced by homogeneously mixing 2.8 g of melted PEG (M = 12,000 g / mol), 0.06 g of trimethylolpropane and 0.12 g of 2,4-TDI.

An approx. 100 μm thick film is drawn from this mixture on a glass plate. The previously coated OPP film is then placed on this film so that the fluoroalcohol is pressed into the liquid matrix. After a curing time of 24 hours, the OPP film is removed, and a contact angle of 105 ± 5 ° could be determined after applying a drop of water. The PUR matrix coated without heptadecanfluor-1-nonanol and hardened for just as long, on the other hand, only has a contact angle of 60 ± 5 °.

Example 6:

A) Preparation of a β-cyclodextrin - peppermint oil complex 1 g of β-cyclodextrin is dispersed in 60 g of distilled water at room temperature and 4 g of peppermint oil are added. After stirring for 15 minutes, the colorless precipitate is filtered off and dried overnight in a desiccator.

Yield: 1.1 g of β-cyclodextrin - peppermint oil complex

B) The ß-cyclodextrin - peppermint oil complex obtained from A) is distilled in 9 g. Slurried water and spread the dispersion on an OPP film with a 20 μm doctor blade. Then allowed to dry at room temperature. The film prepared in this way is applied in an analogous manner to Example 5 on an approximately 100 μm thick PUR film. The film is removed after a curing time of 24 hours.

C) As a comparison test, PUR films are covered with OPP film which is completely uncoated or only coated with β-cyclodextrin.

Claims

Expectations

1.) Method for coating a surface with a coating agent wherein, a) an essentially solvent-free coating agent is applied to the surface, b) a carrier film is provided on one side with at least one additive adhering to the carrier film, c) to which no or incompletely crosslinked or hardened coating, this carrier film is applied with the coated side turned towards the coating, d) the carrier film is kept in contact with the coating agent for at least 0.1 seconds, e) the coating agent is then chemically, thermally and / or is crosslinked or hardened by actinic radiation, and f) the carrier film is removed from the surface after the crosslinking, the additive having at least partially transferred to the surface of the coating.

2.) Method according to claim 1, characterized in that a concentration gradient of the additive with respect to the surface is present in the coating after crosslinking.

3.) Method according to claim 1 or 2, characterized in that a liquid substance is applied as an additive.

4.) Method according to claim 1 or 2, characterized in that a solid substance is applied as an additive.

5.) Method according to claim 1 to 4, characterized in that a substance reactive with the coating agent is applied as an additive.

6.) Method according to claim 3 to 5, characterized in that the additive can diffuse into the coating before crosslinking.

7.) Method according to claim 4 or 5, characterized in that the additive is embedded in the surface before crosslinking.

8.) Method according to claim 1 to 7, characterized in that a biocidal substance is applied as an additive.

9.) Method according to claim 1 to 7, characterized in that an adhesion-improving or an adhesion-worsening substance is applied as an additive.

10.) Method according to claim 1 to 7, characterized in that a surface-hardening substance is applied as an additive.

11.) Method according to claim 1 to 7, characterized in that a surface hydrophobizing or hydrophilizing substance is applied as an additive.

12.) Method according to claim 1 to 7, characterized in that a catalytically active substance is applied as an additive.

13.) Method according to claim 1 to 7, characterized in that a host-guest substance is applied as an additive.

14.) Method according to claim 1 to 13, characterized in that the coating is crosslinked by actinic radiation.

15.) Method according to claim 1 to 13, characterized in that the coating is thermally crosslinked.

16.) Method according to claim 1 to 13, characterized in that a 2-component system is used as the coating agent.

17.) The method according to claim 1, characterized in that the substrate is web or plate-shaped.

18.) Method according to claim 1 to 17, characterized in that the carrier film is removed from the surface immediately after crosslinking.

19.) Method according to claim 1 to 17, characterized in that the carrier film is removed from the surface only later.

20.) Method according to claim 17, characterized in that the substrate is metallic.

21.) Method according to claim 20 for use in the coil coating process.

22.) Object with a coated surface which has been modified on the surface by applying an additive, characterized in that the additive has been applied to the surface via a film before the crosslinking of the coating agent and has been crosslinked or cured immediately afterwards.

23.) Object according to claim 22, characterized in that the concentration of the additive decreases in the depth of the coating.