WO2004054727A1

WO2004054727A1 - Method for coating a surface with a film and corresponding release agent

Info

Publication number: WO2004054727A1
Application number: PCT/EP2003/014175
Authority: WO
Inventors: Stefan Pfnür; Manfred Hunold
Original assignee: Stema Gmbh
Priority date: 2002-12-18
Filing date: 2003-12-12
Publication date: 2004-07-01
Also published as: DE10259355B3

Abstract

The invention relates to a release agent and to a method for coating a surface with a self-adhesive film, whereby the release agent allows the non-residue and non-destructive detachment of the self-adhesive film from the surface. The release agent consists of a composition of water, glycol, ethanol and a dishwashing liquid.

Description

Process for coating a surface with a film and release agent therefor

The invention relates to a release agent and a method for coating a surface with self-adhesive film.

Self-adhesive films are suitable for coating surfaces in order to protect them from damaging mechanical or chemical influences. The appearance and reflection properties of the objects to be coated can also be varied over a wide spectrum by suitable choice of color or motif for the film.

The trend towards coating motor vehicles, in particular passenger cars with foils, has been increasing steadily. The outer appearance color can be varied as desired by applying appropriately colored foils. The color of the vehicle for sale often plays a crucial role, especially for the used car market. By changing the vehicle color by attaching a color film or removing a previously applied film, the color can be adapted to the taste of the prospective buyer and thus significantly increase the probability of sales and sales value.

In addition, certain official or private institutions such as the police, post office, emergency doctors etc. use characteristic recognition or color patterns, which make reselling difficult and significantly reduce the sales value when the fleet is renewed. This high economic loss in value can be avoided by temporary coating with a color film.

Furthermore, the exterior color of vehicles is partially defined by law in relation to use in transport, so that the required regulations can be met by coating with self-adhesive film in the prescribed color. In particular, one should think of coatings for passenger cars, especially in the taxi sector. When the vehicle is sold, the film can be removed. The technology of film coating enables taxi companies, for example, to buy motor vehicles in a color-neutral manner and thus to better utilize used vehicles.

In the field of advertising and publicity there is also a need for options for covering large areas with transparent information such as glass or plexiglass panels with advertising information. The films applied to the back of a pane should either be permanently attached or, depending on the market situation and supply / demand conditions, be exchanged quickly and easily without damaging the slide. In this way, self-adhesive films designed to be effective in advertising can catch the interest of potential customers at public transport stops, shop window passages or to mark entrance doors. In this context, the focus is above all on the need to apply appropriate foils without bubbles or to be able to easily remove cosmetically disruptive air cavities.

A problem with a film coating is, in particular, the adhesiveness of the film to the surface to be coated. On the one hand, the adhesion must be strong enough so that the film does not come off after a short period of use or with low mechanical loads, but on the other hand, excessive adhesion is also not advantageous. If the film adheres too well to the surface, it becomes difficult, for example, to correct errors in the application of the film by pulling it off and pressing it on again without damaging the film or the surface. Liability should also lapse after a long time, e.g. by hardening the adhesive, do not reinforce too much. If, for example, it becomes necessary to remove the film when a vehicle is sold, the removal process becomes relatively time-consuming and therefore cost-intensive if the liability is too pronounced, and damage from peeled-off paint residues and remaining adhesive residues is also likely.

So far, the practice has been such that in order to apply a film free of air bubbles and without wrinkles to larger areas, the surfaces to be coated have been moistened with water and soap. The initial adhesion of the self-adhesive film applied to it is greatly reduced, so that the piece of film can be adjusted exactly. With a squeegee, air bubbles and excess water can then be spread out.

However, such a method is not suitable for the coating or gluing of curved and non-horizontal surfaces, since the film has to be drawn on curvatures, edges, bends and the like or deformed by means of hot air. To prevent the film from being deformed, the film must adhere to these areas immediately with full adhesion. Water as a separating layer on curved and non-horizontal surfaces would not be able to be fixed, since it drains away in accordance with the gravitational interaction and thus would reduce or prevent the film from adhering at those points where it needed full adhesion.

The manufacturers of self-adhesive films try to reduce the initial adhesion by means of the composition of the adhesive or by adding additives to the adhesive and to allow the residual air to be drawn out from under the film.

As described in EP 0 840 675 B1, this can be made possible, for example, by a layer of the finest glass beads on the adhesive layer, which act as spacers. Only by pressing on with the squeegee device are these beads pressed into the adhesive, which can then develop its full adhesive power. However, the composition of various adhesives is such that they initially have a low initial adhesion, which increases after a certain time.

The disadvantages of these methods lie in the relatively complex production and the associated costs.

From DE 44 42 670 Cl a method for applying self-adhesive films to motor vehicles is known, wherein before the motor vehicle is covered with the self-adhesive film, a release agent is applied to the surface to be covered with the self-adhesive film. Individual edge areas are left out of the release agent application. In this method, a release agent, the mineral and synthetic oils or fats, such as. B. Vaseline or fat cream used. The disadvantage of this method is that after the self-adhesive film has been removed, the release agent remains on the surface as an oily or greasy layer and can only be removed from the surface at great expense and at great expense.

The invention has for its object to develop a method and a release agent through which the disadvantages described above can be avoided.

The self-adhesive film should be able to be placed on the surface to be coated with a low initial adhesion in order to enable precise application, i. H. the film should be relatively easy to remove and put back on again in a corrected manner.

Furthermore, the release agent should be able to be applied to the surface with little effort.

The release agent should not run and should be able to be applied to smooth surfaces as well as to curved, uneven and non-horizontal surfaces.

By using the release agent, the air bubbles formed under the film during application should be easily spreadable with a doctor device.

Finally, after removing the self-adhesive film, the release agent should be easy to remove from the surface again.

The object is achieved according to the invention by a release agent according to patent claim 1 and a method according to patent claim 8. Advantageous further developments of the invention are defined in the dependent claims.

The release agent according to the invention contains water, glycol, ethanol and a dishwashing detergent.

It is advantageous if the proportion of dishwashing detergent is between 5 and 10 Volume percent is. The function of the dishwashing detergent is to separate the film surface and the surface to be coated from one another by the surface-active substances it contains, which carry oppositely charged groups.

If the proportion of dishwashing detergent is higher, the applied film becomes too concentrated, so that the separation effect predominates and the film no longer adheres when it is applied. If, on the other hand, the proportion of dishwashing detergent is lower, the initial adhesion of the film is too high, so that the film is difficult to remove even after a long period of use, if correction is necessary.

Any commercially available dishwashing detergent can be used. In particular, dishwashing detergents for private households, such as e.g. "Pril" or "Tempo" suitable.

It is particularly advantageous if the proportion of dishwashing detergent is 8 percent by volume.

In a particular embodiment of the release agent according to the invention, the proportion of ethanol is between 5 and 20 percent by volume. The ethanol improves the solubility of the dishwasher detergent in water. The hydrophobic portion of the ethanol interacts with the hydrophobic areas of the surfactants, while the hydrophilic hydroxyl group guarantees solubility with the water matrix. As a result, the ethanol significantly influences the ability of the self-adhesive film to make contact with the surface.

It is particularly advantageous if the proportion of ethanol is 12 percent by volume.

In a special embodiment of the release agent according to the invention, the proportion of glycol is between 10 and 30 percent by volume. The function of the glycol is to optimize the viscosity and thus the spreadability or sprayability as well as the adhesion of the release agent on the surface. If the proportion by weight of glycol is too high, the release agent is too viscous and not more brushable or sprayable. If the proportion of the glycol is too low, the release agent is too low in viscosity, so that it can flow off easily from curved and curved surfaces, making it difficult to apply the release agent evenly.

It is particularly advantageous if the proportion of glycol is 20 percent by volume.

The invention also relates to a method for coating a surface with a self-adhesive film, the release agent according to the invention being used.

Closed lacquered or smooth surfaces are particularly advantageous as surfaces. Open-porous lacquer surfaces are less suitable because the release agent penetrates into the openings and cavities near the surface and is therefore no longer available at the interface.

In these cases, a polishing or sealing process should take place before the method according to the invention can be used.

Ground glass fiber or carbon fiber plates, such as those used for example in kitchen facilities, but also for motor vehicle bodies, are also suitable as surfaces.

In an advantageous embodiment of the method according to the invention, the method comprises at least the following steps:

- providing the surface;

- application of the release agent on the surface, e.g. by spraying or by a cloth soaked in the release agent;

The release agent can, for example, be applied to the surface as a thin film using a pressure sprayer.

- curing or drying the release agent applied to the surface; The drying process can be accelerated with the help of a warm air blower.

The hardening or drying process improves the consistency of the release agent. The release agent forms a thin, even layer on the surface. After drying, another layer of release agent can be applied, which in turn is followed by a drying process. Depending on the surface properties, this cycle can be repeated several times, so that rough and open-pored materials such as wood can also be coated in a suitable manner.

- Apply the self-adhesive film to the surface.

The self-adhesive film is applied in a known manner and therefore need not be explained in more detail.

To ensure that the film adheres quickly in certain problem areas such as edge areas or deep-drawn areas of the surface, it is advisable to briefly heat these areas to a temperature of around 60 ° to 80 ° C using an industrial hair dryer. In the case of deep-drawn areas, so-called "beads", as they often occur on vehicle bodies, it is also advisable to clean the surface with ethanol before applying the release agent.

In a particularly advantageous embodiment of the method according to the invention, motor vehicles are coated.

When applying the film to motor vehicles, as is taught in DE 44 42 670, it can be expedient that the edge areas of the door surface, the beads and the door handle recess are spared by the release agent which is otherwise applied flatly, since here the film adheres completely is required; the adhesion of the film is reduced on the other surface areas, which makes it easier to remove the film coating.

In a further advantageous application of the method according to the invention, transparent surfaces are coated on the back by applying a self-adhesive film. The film can be a mirror image wear written lettering, which is visible through the transparent surface. Glass or plexiglass panes, for example, are suitable as transparent surfaces.

Up to now, appropriate foils had to be glued wet on these surfaces in order to allow the subsequent easy removal of unsightly air voids. However, the subsequent drying process takes a relatively long time.

The method according to the invention allows self-adhesive films to be applied easily to transparent surfaces and the air voids to be removed quickly without the use of additional moisture. The drying process required in conventional processes can thus be dispensed with and valuable working time can be saved.

By applying the method described in the claims, the application of the film coating and later the removal while protecting the surface is much easier. Even after years of use, whereby the adhesive often converts to a cement-like layer that sticks extremely stubbornly to the surface, the film can be removed without leaving any adhesive residues and without damaging the surface. Under conventional circumstances, these residues had to be removed at great expense in terms of time and expense, although it could not be ruled out that the surface would be affected in the required complex cleaning process, for example by changing the reflective properties or detaching layers near the surface. The release agent itself is readily water-soluble and can also be removed completely by simply rinsing it off without leaving any residue.

Claims

Patent claims

1. Release agent, which contains water, glycol, ethanol and a dishwashing detergent.

2, parting agent according to claim 1, wherein the proportion of dishwashing agent is between 5 and 10 percent by volume.

3. Release agent according to claim 2, wherein the proportion of dishwashing detergent is 8 percent by volume.

4. Release agent according to one of claims 1 to 3, wherein the proportion of ethanol is between 5 and 20 percent by volume.

5. Release agent according to claim 4, wherein the proportion of ethanol is 12 percent by volume.

6. Release agent according to one of claims 1 to 5, wherein the proportion of glycol is between 10 and 30 percent by volume.

7. Release agent according to claim 6, wherein the proportion of glycol is 20 percent by volume.

8. A method for coating a surface with self-adhesive film, a release agent according to one of claims 1 to 7 being used.

9. The method according to claim 8, comprising at least the following steps:

- providing the surface; - applying the release agent to the surface;

- curing or drying the release agent applied to the surface;

- Apply the self-adhesive film to the surface.

10, The method according to any one of claims 8 or 9, wherein motor vehicles are coated.

11. The method according to any one of claims 8 or 9, wherein transparent surfaces are coated on the back.