EP0842054B1

EP0842054B1 - A method for applying paint to a surface

Info

Publication number: EP0842054B1
Application number: EP97920834A
Authority: EP
Inventors: Michael James Smith; Lezlie Hill
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Chemical Industries Ltd
Priority date: 1996-05-04
Filing date: 1997-05-02
Publication date: 2000-07-05
Anticipated expiration: 2017-05-02
Also published as: DE69702432T2; DE69702432D1; WO1997042041A1; AU2706497A; GB9609411D0; EP0842054A1; CA2253331A1; ATE194314T1

Abstract

Paint is applied to a surface system as a wall using a paint application system comprising a releasable backing (10) formed of water-permeable paper having a water-release layer thereon. The system includes a decoration layer (12) and a transparent barrier layer (13) disposed between the decoration layer (12) and the releasable backing (10). The decoration layer (12) is formed of a dried paint composition, e.g. a dried aqueous emulsion paint, comprising one or more pigments in a polymeric binder. An adhesive layer (14) is disposed on an opposite side of the decoration layer (12) to the barrier layer (13). The adhesive layer (14) is engaged with the surface to be decorated by the decoration layer (12). The backing (10) is removed so as to enable the decoration layer (12) applied to said surface to be viewed through the barrier layer (13). The barrier layer (13) prevents the adhesive of the adhesive layer reaching an outer surface of the applied layers.

Description

This invention relates to a method of decorating a surface such as interior walls, ceilings, doors, panels (metal, wood or plastics), trims or the like with paint, and also to a paint application system for use in such a method.

It is well known to decorate a surface using paint by applying a layer of liquid paint to the surface using a brush or roller, and allowing the resultant paint layer to dry. However, it requires a great deal of skill to apply the paint layer evenly and to prevent the paint from dripping or running whilst it is being applied, or after it has been applied and before it has dried. The use of thixotropic agents in the paint can assist in preventing dripping or running of the paint, but it can be even more difficult to apply such paint evenly over a large area. Additionally, the surface to be painted may be formed of a material which is incompatible with the paint being used. Another disadvantage of these known paints is that the appearance of the applied paint layer can be spoilt if it is touched or rubbed whilst still wet. Additionally, the formation of a patterned or textured paint layer requires an even greater skill on behalf of the painter or decorator. Furthermore, any unused paint in the container in which it is supplied tends to dry out unless very carefully protected. As a result, it may be difficult or impossible to use any left-over paint in a subsequent painting operation, thus potentially leading to considerable wastage.

US-A-4211810 discloses a self-adhering transfer having one or more layers of varnish or colour for applying lettering to signs, machines and devices for communication, information or warning purposes. The transfer has a releasable carrier on which are provided in order, a separating layer, one or more of the varnish or colour layers, a polyester resin intermediate blocking layer, an optional primer layer, an adhesive layer and a removable silicone paper layer. The materials used to form the colour layers are stated to be physically drying screen printing colours.

It is an object of the present invention to obviate or mitigate the above disadvantages.

According to a first aspect of the present invention, there is provided a method of decorating a surface with paint, said method comprising the steps of (a) providing a paint application system comprising a releasable backing, a decoration layer, a barrier layer, and an adhesive layer which is effective at a temperature of 5-35°C and which is disposed on an opposite side of the decoration layer to the releasable backing, wherein the decoration layer is formed of a dried paint composition comprising one or more pigments in an acrylic polymer, vinyl polymer or alkyd resin binder, and wherein the barrier layer is provided between the releasable backing and the adhesive layer; (b) engaging the adhesive layer of the paint application system with the surface to be decorated; and (c) removing the releasable backing so as to expose the applied decoration layer of the dried paint composition to view, the barrier layer preventing the adhesive of the adhesive layer from reaching an outer surface of the applied layers.

It will therefore be understood that the method of the present invention does not require the use of a liquid paint at all at the time of decoration and so does not possess any of the above disadvantages of using such a liquid paint during decoration.

According to a second aspect of the present invention, there is provided a paint application system for use in the method according to said first aspect of the present invention, said system comprising a releasable backing, a decoration layer, a barrier layer, and an adhesive layer which is effective at a temperature of 5-35°C and which is disposed on an opposite side of the decoration layer to the releasable backing, said barrier layer being provided between the adhesive layer and the releasable backing, wherein the decoration layer is formed of a dried paint composition comprising one or more pigments in an acrylic polymer, vinyl polymer or alkyd resin binder, and wherein when the adhesive layer of the system is engaged with a surface to be decorated, the releasable backing can be removed so as to expose the applied decoration layer of the dried paint composition to view, the barrier layer preventing the adhesive of the adhesive layer from reaching the outer surface of the applied layers.

The decoration layer may be or include (i) a continuous paint layer of any desired colour shade (including white or black) over the whole area of the backing; (ii) a continuous textured or patterned paint layer; (iii) a paint layer which is discontinuous over the area of the backing and which includes any one or more of a picture, pattern or ornamentation, or (iv) any combination of these.

The dried paint composition may be the same as or similar to a conventional paint of a type used in the decoration of surfaces found in buildings. The thickness of the dried paint layer is preferably about 30 to 200 µm, more preferably about 30 to 80 µm.

Useful paints include aqueous latexes of acrylic or vinyl polymers or organic solvent-borne alkyd resins all having weight average molecular weights of over 200,000 and viscosities of from 0.15 to 1.2 (preferably 0.4 to 0.8) pascal second (Pa.s) when measured at 25°C using an electrically operated "Rotothinner" according to the method of use for the "Electric Operated Model" as described in the leaflet "Sheen/ICI Rotothinners" available from Sheen Instruments Limited of Kingston-on-Thames, England.

Typical examples of acrylic polymers are the polymers and copolymers of alkyl unsaturated carboxylates, especially C₁ to C₈ alkyl acrylates and/or methacrylates and in particular the methyl, ethyl, butyl and 2-ethylhexyl esters. These alkyl esters are frequently copolymerized with acrylic or methacrylic acids to provide groups convertible to salts to confer water-solubility or hydrophilic characteristics. Other possible co-monomers include ethylenically unsaturated monomers such as ethylene, styrene, butadiene and vinyl chloride. Preferred acrylic polymers and copolymers have weight average molecular weights of from 500,000 to at least 1,000,000 and above where meaningful determination of molecular weights becomes difficult and ceases to be worthwhile.

Typical examples of vinyl polymers are the polymers and copolymers of vinyl carboxylates of which vinyl acetate and vinyl esters of C₁₀ to C₁₄ acids are the most important. Hydrophilic character is often imparted to the polymers by hydrolysing a portion of the acetate or other carboxylate moieties to form hydroxyl moieties, ie. notional copolymerized vinyl alcohol. The weight average molecular weight of vinyl polymers and copolymers is preferably from 100,000 to 1,000,000.

Alkyd resins are formed by the partial condensation of polyols such as glycerol or pentaerythritol with dicarboxylic acids or anhydrides such as isophthalic anhydride and terephthalic acid, and then condensation of unreacted hydroxyl groups with long chain (C₁₂ to C₃₀) unsaturated fatty acids such as oleic, ricinoleic, linoleic, linolenic and licanic, all derivable from natural oils. The minimum weight average molecular weight of useful alkyd resins is usually 100,000 and preferably 200,000. However, the possibilities for cross-linking mean that their molecular weights may be very much higher and often in the region where molecular weight determinations become meaningless.

The aqueous paints (eg the acrylics or vinyls) preferably contain from 1 to 10 wt% of drying retarder, typically a high boiling (boiling point preferably above 150°C) drying retarder liquid. Preferred retarders are alcohols, ethers or carboxylates such as ethylene glycol, propylene glycol, poly(ethylene glycols) or poly(propylene glycols) of number average molecular weight 250 to 5,000 and preferably 250 to 500, methoxy propanol, di-isobutyl adipate and trimethyl pentanediol isobutyrate. Toxicity considerations lead to a preference for propylene glycol (usually used in amounts of from 4 to 7 wt%) and poly(ethylene glycols) usually used in amounts of from 1 to 4 wt%.

Paints suitable for use in this invention will normally contain white opacifying pigment which is usually rutile titanium dioxide in combination with pigments imparting other colours. These pigments (insoluble colourants), which are commonly used in the paint industry, are distinguished from dyestuffs (soluble colourants) which are commonly used in the printing industry and which are relatively expensive. The efficiency of the pigments will generally be promoted by the presence of so-called extenders which space apart the pigment particles. Extenders include china clay (kaolin), chalk, powdered limestone and talc.

The barrier layer will normally be a matt or gloss transparent layer (eg. a lacquer), disposed between the backing and the decoration layer. It may be, for example, in the form of an acrylic resin in a solution of hydrocarbon solvent. The solvent may contain trimethylbenzene or diacetone alcohol. However, it is possible for the barrier layer to be disposed between the decoration layer and the adhesive layer if the nature of the backing and the decoration layer are such that they can be mutually separated.

In one embodiment of the present invention, the backing comprises a water-permeable substrate having a release layer thereon which is in contact with the barrier layer, the release layer being water-sensitive so as to allow the substrate to be separated from the barrier layer and the decoration layer when water which has permeated through the substrate reaches the release layer. The water-permeable substrate is preferably formed of paper and preferably has a thickness in the range of 80 to 135 µm, more preferably 90 to 120 µm. The use of such a backing is advantageous in that it is strong enough to enable it to be handled without damage prior to being adhered to the wall in use, whilst it is sufficiently pliable for it to be applied successfully to a relatively rough or textured wall.

In cases where the decoration layer contains design features requiring particular orientation or positioning on the surface being decorated, it is preferred for the reverse side of the backing, ie. the side opposite to that carrying the above-mentioned layers, to have lines and/or other markings thereon to assist in correct orientation or positioning of these design features of the decoration layer on the surface.

In an alternative embodiment, the backing comprises a stretchable film which is preferably biaxially stretchable. In a particularly convenient embodiment, the film is a stretchable cast polypropylene or polyethylene film. The stretchable film is preferably translucent to permit correct positioning of the decoration layer on the wall, particularly when it includes design features requiring particular orientation or positioning.

The thickness of the stretchable film is preferably in the region of 20 to 60 µm, most preferably 30 to 40 µm. The stretchable film preferably has an elongation DT break of 400 to 800%, and preferably has a tensile strength of 10 to 12 N/mm².

The stretchable film is preferably releasably carried on a substrate or support. A low-tack adhesive layer, eg an aqueous based adhesive such as an EVA, PVA or acrylic adhesive, may be used for this purpose. Release of the stretchable film can be effected simply by peeling it from the substrate or support without the need to moisten the latter.

The substrate or support used to carry the stretchable film is preferably a cast-coated paper, although it may be any other form of substrate or support, eg. a silicone-impregnated paper. Since the substrate or support for the stretchable film is intended to be peeled away before application to the surface to be decorated, the above-mentioned preferred thickness limitations for the backing of said one embodiment above are no longer preferred.

The backing may be of any desired size and/or shape. For example it may take the form of an elongate sheet which may be provided in the form of a roll so as to enable the decoration layer to be applied over a large surface area, for example even over the whole of a wall or walls of a room so that the decoration layer of dried paint can be applied in an analogous way to applying wallpaper except that, in the present invention, the backing does not remain secured to the wall in the final decorated wall.

Thus, in one embodiment of the method of the present invention, the surface is a wall, at least one length of the paint application system is applied to the wall so as to extend from the top to the bottom of the wall, and the backing is removed.

The adhesive layer is preferably clear. The adhesive layer may be derived from an aqueous or a solvent-based adhesive formulation, preferably the former. The adhesive layer is one which is effective at a temperature in the range of 5 - 35°C so that no special measures such as heating to activate the adhesive need be employed. The adhesive layer is most preferably a pressure-sensitive adhesive having a high peel-strength. A peel-away layer, eg. a silicone-coated paper, may cover the adhesive layer to protect it until immediately before it is engaged with the surface to be decorated.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

Fig. 1 is a schematic exploded perspective view of one embodiment of a paint application system used in the invention,

Fig. 2 is an exploded side view of the system of Fig 1, showing the layers thereof, and

Fig. 3 is a schematic section through another paint application system according to the present invention.

Referring now to Fig. 1, the paint application system is designed to be applied to a surface such as a wall, ceiling, panel or the like, particularly in a domestic environment, effectively to provide a painted pattern on such surface, in place of, or complementing, wallpaper. The system of Fig. 1 is particularly suitable for use where the wall has a textured covering providing a ridged or otherwise rough surface, and it can also be used to decorate a surface to which conventional emulsion paint has been applied. Fig. 1 shows the basic structure of the system which is made up of five layers. As used herein, the term 'layer' is used to cover not only complete sheets, but also other components contributing to the thickness of the system, such as the dry paint pattern to be applied, as well as adhesive, and barrier applied only in the area of the pattern rather than in the form of a sheet. In other words, a layer of the system can be any component contributing to the thickness thereof.

In Fig. 1, the system is shown as having a backing formed of a water-release base paper 10 which is shown to be of square/rectangular shape. This base paper 10 constitutes one outer layer of the system. The other outer layer is, in this embodiment, formed as a protective sheet 11, of the same or substantially the same shape as the base paper 10. A decoration layer 12 is formed as a middle layer which is, in use, applied to a surface to be decorated. In this embodiment, the decoration layer 12 is a dried painted pattern in the form of a portion of a rose bush formed of screenprinted emulsion paint. Relative to the inner surface of the base paper 10, this would normally be printed in reverse, i.e. a mirror image, as would be the case for non-symmetrical designs. Between the decoration layer 12 and the base paper 10 is a barrier layer 13, the shape and extent of this layer 13 matching that of the paint pattern, and similarly being printed in reverse. Similarly matching the shape and extent of the painted pattern is a clear adhesive layer 14 disposed between the decoration layer 12 and the protective sheet 11, and also in reverse. The arrangement of layers of the system is shown in enlarged detail in Fig. 2, with the

layers

13, 14, in this embodiment, being shown to extend somewhat beyond that of the decoration layer 12.

By way of example, various possible compositions for the layers making up the paint application system will now be referred to. However these are by way of example only and can be varied as required.

The base paper 10 can be paper having a thickness of preferably between 80-135 µm which has been coated with a sealant layer, and a water-release layer formed e.g. of dextrin or other water-soluble gum. After wetting, the paper is capable of being peeled away by virtue of the provision of the release layer.

The barrier layer 13 is in the form of a matt or gloss transparent lacquer, this being, for example, in the form of an acrylic resin in a solution of hydrocarbon solvent. The solvent may contain trimethylbenzene or diacetone alcohol. The purpose of this barrier layer 13 is to prevent seepage of adhesive from the adhesive layer to the outer surface of the applied layers, in use. Without the barrier layer 13, adhesive seeping through the decoration layer 12 would produce a 'tacky' feel to the touch at the outer surface, ie. the finished surface, of the applied layers. As mentioned, the barrier layer 13 matches the shape and form of the colour image defined by the decoration layer 12, and this layer 13 is, for example, printed onto the base paper using a conventional silk screen process.

The decoration layer 12 defining the required colour image is, for example, applied by screen printing an aqueous emulsion paint such as that sold by ICI Paints under the Registered Trade Mark DULUX, but containing 5 wt% of a drying inhibitor, such as propylene glycol, to prevent the emulsion paint from drying in the screen and to ensure a smooth coating of the paint forming the decoration layer. The emulsion paint is then dried either by natural air drying on a rack or by forced air drying using warm air so as to complete the decoration layer.

The adhesive layer 14, which like the layer 13, matches or substantially matches the shape and extent of the colour image defined by the decoration layer 12, can be a spirit-based, high-tack pressure sensitive adhesive which comprises a synthetic rubber composition in a mixture of aromatic and aliphatic solvents.

Finally, the protective sheet 11 can be a transparent silicone release paper of silicone-treated vegetable parchment. This serves merely to protect the adhesive layer 14 prior to use.

Preferably, though not essentially, the release-layer coated base paper is similar to that produced by Tullis Russell Brittains Decalcomania Papers Ltd. and known as FOTOCAL paper for the production of transfers using a colour photocopying technique. The paper employed therein has a thickness of about 110 µm.

In use, the protective sheet 11 is removed and the remaining layers are applied to the surface to receive the decoration layer 12, with the adhesive layer 14 being engaged directly against the surface so as to adhere securely thereto. The outer face of the base paper 10 is then sponged with water, preferably tepid water, until it is substantially soaked.

Approximately 15 to 20 seconds later, with the water having permeated through the paper 10, and loosened the release coating thereon, it is possible for a user to grip a corner of the paper 10 and to peel it off the surface being decorated, the barrier layer 13 carrying the paint design forming the decoration layer 12 detaching itself from the paper 10, thereby leaving the remaining

layers

12, 13 and 14 in place with the dried paint pattern decorating the surface. The sheet 11 would normally be provided, in use, between pairs of laminates in a stack, but could be omitted if required, though some means of preventing premature sticking of the adhesive layer would normally be required.

As explained above, the use of a particular water-release base paper provides a peel-off release which is particularly suitable for decorating rough or emulsioned walls or other corresponding surfaces.

It will be appreciated that although, as described, both the barrier layer and the adhesive layer match or substantially match the shape and extent of the painted pattern of the decoration layer 12, this is not essential, although normally they would not be of smaller shape/extent than the painted pattern 12. They could however be larger, and indeed could merely be in the form of sheets equivalent to the

sheets

10 and 11.

In a further modification (not shown), the decoration, barrier and

adhesive layers

12, 13 and 14, are provided on a biaxially stretchable cast polypropylene film carried on a cast-coated paper substrate through the intermediary of a low-tack adhesive layer. In a particular example of this modified arrangement, the cast-coated paper substrate has a thickness of 155 µm and has a surface smoothness of <0.6 µm (Parker Print Surf conditions S10) at its surface upon which the low-tack adhesive layer is provided. The low-tack adhesive layer has a thickness of 15 µm and is an EVA/PVA blend of controlled surface tension, of the type available from Autobond Ltd under the designation 0110/1. The stretchable cast polypropylene film has a thickness of 30 µm and is of the type available from Rexham under the designation CEX001.

The stretchable cast polypropylene film is cut through around the area of the localised pattern of the decoration layer to enable localised separation of the appropriate part of the polypropylene film from the paper substrate.

In use, the laminate consisting of the adhesive layer, the decoration layer, the barrier layer and the polypropylene film are peeled away from the paper substrate prior to application to the wall to be decorated, this being permitted by the low-tack adhesive layer. This laminate is applied, adhesive layer down against wall to be decorated. The stretchable nature of the polypropylene film permits the decoration layer and the barrier layer to lie in intimate contact with the surface of the wall even if it is relatively rough and/or has a textured surface. The polypropylene film is then peeled away.

Referring now to Fig. 3, parts of the system which are similar to those of the embodiment of Fig. 1 are accorded the same reference numerals. In this embodiment however, the system illustrated therein comprises a water-permeable paper backing 10 in the form of a continuous or semi-continuous web having the above-described release layer thereon. The barrier layer 13 is applied uniformly over the whole of one surface of the backing 10. Likewise, the decoration layer 10 is a plain (i.e. unpatterned) layer of aqueous emulsion paint which is applied uniformly over the whole of the surface of the barrier layer 13, and the adhesive layer 14 is also a complete covering layer. However, the decoration layer 10 could be patterned or textured. Subsequently, the coated web thus produced is cut into relatively long lengths such as are commonly used for wallpaper, and wound to form rolls which are then packaged and sold for use in place of wallpaper to provide a complete covering of dry paint from top to bottom of a wall or walls of a room.

Claims

A method of decorating a surface with paint, said method comprising the steps of (a) providing a paint application system comprising a releasable backing, a decoration layer, a barrier layer, and an adhesive layer which is effective at a temperature of 5-35°C and which is disposed on an opposite side of the decoration layer to the releasable backing, wherein the decoration layer is formed of a dried paint composition comprising one or more pigments in an acrylic polymer, vinyl polymer or alkyd resin binder and wherein the barrier layer is provided between the releasable backing and the adhesive layer; (b) engaging the adhesive layer of the system with the surface to be decorated; and (c) removing the releasable backing so as to expose the applied decoration layer of the dried paint composition to view, the barrier layer preventing the adhesive of the adhesive layer from reaching an outer surface of the applied layers.
A method as claimed in claim 1, wherein the decoration layer is or includes a continuous paint layer of a colour including white or black.
A method as claimed in claim 1, wherein the decoration layer is or includes a picture, pattern or ornamentation, or any combination thereof.
A method as claimed in claim 1, 2 or 3, wherein the polymeric binder comprises particles derived from a dispersion or solution of a film-forming polymer.
A method as claimed in claim 1, 2 or 3, wherein the dried paint composition is a dried emulsion paint composition.
A method as claimed in claim 5, wherein the dried emulsion paint composition is derived from an emulsion paint composition containing up to 10 wt% of a drying retarder.
A method as claimed in any preceding claim, wherein the backing comprises a water-permeable substrate having a release layer thereon which is in contact with the barrier layer, the release layer being water-sensitive, and wherein the water-permeable substrate is dampened after step (b) so as to allow the latter to be removed in step (c) when water which has permeated through the substrate has reached the release layer.
A method as claimed in any one of claims 1 to 6, wherein the backing comprises a stretchable film.
A method as claimed in claim 8, wherein the stretchable film is releasably carried on a substrate or support and is released from the latter before step (b).
A method as claimed in any preceding claim, wherein the surface is a wall, and at least one length of the paint application system is applied to the wall so as to extend from the top to the bottom of the wall by engaging the adhesive layer with the wall in step (b).
A paint application system for use in the method according to any preceding claim, said system comprising a releasable backing, a decoration layer, a barrier layer, and an adhesive layer which is effective at a temperature of 5-35°C and which is disposed on an opposite side of the decoration layer to the releasable backing, said barrier layer being provided between the adhesive layer and the releasable backing, wherein the decoration layer is formed of a dried paint composition comprising one or more pigments in an acrylic polymer, vinyl polymer or alkyd resin binder, and wherein when the adhesive layer of the system is engaged with a surface to be decorated, the releasable backing can be removed so as to expose the applied decoration layer of the dried paint composition to view, the barrier layer preventing the adhesive of the adhesive layer from reaching the outer surface of the applied layers.