DE202022102535U1 - Film remover - Google Patents

Abstract

Film solvent, consisting of more than 50% by mass of an organic solvent or solvent mixture and a thickener, the solvent molecule(s) containing 2 to 4 oxygen atoms, of which at least one oxygen atom is doubly bonded to a carbon atom, or four ether groups or a nitrile group has, characterized in that the solvent or the mixture thereof has a vapor pressure at 20 ° C of over 0.1 hPa and under 30 hPa.

Description

The present invention relates to a film remover, in particular for the removal of plastic films, and in particular self-adhesive plastic films, from hard surfaces.

Acetone-based film removers are known. Such film removers are, on the one hand, dangerous because of their easy flammability, and on the other hand, their practical use is severely limited because of the rapid evaporation of the solvent. Out of EP 0 124 849 B1 A solvent-free agent for removing polymeric protective layers is known, but cannot remove all films. Out of WO 2004/090 085 A1 is a stripper for paints and the like that is completely free of volatile solvents, VOC. This stripper removes films too slowly.

There is therefore still a need for a less dangerous film remover that nevertheless adheres to the surfaces to be cleaned for a sufficiently long time that films applied to them are reliably removed or attacked to such an extent that they can be easily removed mechanically. Examples of films are PVC films.

The present invention provides the film removers according to claims 1 and 2 and the uses according to claims 14 and 16.

According to the first aspect of the invention, the film solvent contains at least 50% by mass of an organic solvent with two to four oxygen atoms, of which up to two are in carbonyl groups or with four ether groups or with a nitrile group, or a mixture of such, and has a sufficiently high Boiling point or correspondingly low vapor pressure (at room temperature), namely below 30 hPa, but above 0.1 hPa. Preferably all but one of the hydrogen atoms are bonded to carbon atoms, more preferably all of the hydrogen atoms. More preferably, 5 to 8 carbon atoms are present. If the film remover only contains one solvent component, a thickener is also present.

The components preferably have molecular weights of 103 to 200 g/mol and/or boiling points of 114 to 228°.

Due to the relatively high boiling point of its components, this film remover does not evaporate prematurely before the film to be removed is sufficiently attacked to be removed mechanically or comes off on its own. In the context of this application, plastic films are understood to mean films that were already solid films before they were attached to the substrate.

In embodiments, the main component (i.e. >50% by mass) of the film solvent is an organic solvent with at least one oxygen atom doubly bonded to a carbon atom or four ether groups, or a mixture of such solvents, in particular those with a molecular weight of 103-200 g/mol. Dibasic esters, alkanoic acid monoalkyl esters, terminal alkoxy esters, and oligoglycol ethers such as 2,5,7,10-tetraoxaundecane (TOU), and/or nitrogen compounds such as benzonitrile are particularly suitable. Smaller amounts of more volatile components such as acetone (<5% by mass) and butanone (<20% by mass) may also be present. Low-volatile components with a vapor pressure at 20 ° C of less than 0.1 Pa are preferably only contained at a maximum of 10% by mass.

The film remover preferably has a vapor pressure of less than 20 hPa, less than 15 hPa, less than 10 hPa or less than 5 hPa at 20 ° C.

Particularly preferred are those mixtures whose evaporation number (based on diethyl ether), determined according to DIN 53170, is at least 5 times the minimum effective time specified in minutes for the dissolution of a PVC film at 20 ° C and normal pressure. Alternatively, the evaporation number is chosen according to ASTM D3539, i.e. based on n-butyl acetate (which itself has an evaporation number of 12 based on diethyl ether). The duration of action refers to a removal of 90% of the surface of a 75 µm thick PVC film, with the film lifting off on its own.

The presence of the C=O double bonds in question can be easily detected using an IR spectrum, since these bonds cause strong absorption at characteristic wave numbers (carbonyl band at approx. 1550-1900 cm ^-1 , i.e. where there are hardly any other absorptions gives). The vapor pressure of a mixture can also be clearly determined, although careful thermostat control and the complete exclusion of foreign gases must be ensured. However, the vapor pressure of a mixture is not always exactly additive from the vapor pressures of its components weighted by the respective mole fraction, especially not when very different (e.g. polar and apolar) components are present next to each other, because specific deviations then occur.

If necessary, the film remover can additionally contain thickeners (e.g. cellulose ethers such as methyl hydroxypropyl cellulose, available under the name Tylose), which slows down or prevents drainage from inclined or vertical surfaces. A solubilizer with a molecular weight below 100 g/mol (for example ethanol) can then also be included.

According to the second aspect of the invention, use of the film remover includes removing one or more films from a painted surface, where the base surface may be a metal, glass, plastic or wooden surface in embodiments. The use of the film remover includes first applying it to the film to be removed, then, if necessary, the subsequent application of further film remover to dried areas, especially on overhead edges, and finally the removal of residues of the film to be removed by peeling or wiping it off the surface, if necessary with the help of a tool. In some cases, an adhesive layer of the film remains on the surface to be cleaned; This adhesive layer can then be removed with a conventional cleaning agent. The time period between the initial application of the film remover to the film and the complete removal of the film is defined as the exposure time: Then the evaporation time according to DIN 53170 is preferably greater than 5 times the exposure time in minutes; more preferably less than 50 times this.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0124849 B1 [0002]
• WO 2004090085 A1 [0002]

Claims (21)

Film solvent, consisting of more than 50% by mass of an organic solvent or solvent mixture and a thickener, the solvent molecule(s) containing 2 to 4 oxygen atoms, of which at least one oxygen atom is doubly bonded to a carbon atom, or four ether groups or a nitrile group has, characterized in that the solvent or the mixture thereof has a vapor pressure at 20 ° C of over 0.1 hPa and under 30 hPa. Film solvent, consisting of more than 50% by mass of a mixture of organic solvents and optionally a thickener, the molecules of each mixture component having 2 to 4 oxygen atoms, of which at least one oxygen atom is doubly bonded to a carbon atom or four ether groups or a nitrile group, characterized in that that the solvent mixture has a vapor pressure at 20 ° C of over 0.1 hPa and under 30 hPa. Film remover Protection claim 1 or 2 , wherein the solvent or the components of the mixture have or have 5 to 8 carbon atoms. Film remover Protection claim 3 , including dibasic esters, alkanoic acid monoalkyl esters, terminal alkoxy esters, in particular vicinal diones, 2,5,7,10-tetraoxaundecane, TOU, and/or 2,5,8,11-tetraoxadodecane, TEGDME. Film remover according to one of the preceding claims, wherein the solvent mixture contains less than 5% by mass of acetone and less than 20% by mass of butanone-2. Film remover according to one of the preceding claims, wherein the solvent mixture contains less than 10% by mass of low-volatility components with a vapor pressure at 20 ° C of less than 0.1 Pa. Film remover according to one of the preceding claims, wherein the solvent has an average molecular weight, or the components of the solvent mixture each have a molecular weight of 103 to 200 g/mol. Film remover Protection claim 7 , further containing a solubilizer for gelling the thickener, the solubilizer having a molecular weight of less than 100 g/mol. Film remover according to one of the preceding claims, the vapor pressure of which at 20°C is below 20 hPa, below 15 hPa, below 10 hPa or below 5 hPa. Film remover according to one of the preceding claims, wherein the content of the solvent or solvents is over 55% by weight. Film remover according to one of the preceding claims, wherein the flash point is above 65°C. Film solvent according to one of the preceding claims, wherein the boiling points of the solvent components are between 114°C and 228°C. Film remover according to one of the preceding claims, wherein all hydrogen atoms of the solvent components are bonded to carbon atoms. Use of the film remover according to one of the preceding claims for removing one or more films from a hard surface. Use after Protection claim 14 , where the surface is a glass surface, a metal surface, a plastic surface or a wooden surface. Use after Protection claim 14 , where the surface is a painted surface. Use after Protection claim 16 , where the base surface under the paint is a metal surface, a plastic surface or a wooden surface. Use of a composition containing more than 50% by mass of an organic solvent or a mixture thereof and optionally a thickener as a film solvent, characterized in that the molecules of the solvent or each mixture component contain either 2 to 4 oxygen atoms, of which at least one oxygen atom is doubly bonded to a carbon atom, or have four ether groups or one nitrile group, and the solvent or mixture thereof has a vapor pressure at 20 ° C of over 0.1 hPa and under 30 hPa. Use after one of the Protection claims 14 until 18 , whereby the evaporation number of the film remover according to DIN 53170 is at least 5 times its exposure time in minutes, the exposure time being the period of time between the initial application of the film remover to the film to be removed and the 90% detachment based on the area of the film under normal conditions, where The exposure time refers to a PVC film that is 50 to 150 µm thick and is to be removed. Use after Protection claim 19 , whereby the evaporation rate of the film remover is a maximum of 50 times its exposure time in minutes. Use after one of the Protection claims 14 until 20 , for defoliating motor vehicles or rail vehicles.