EP4093617A1 - Wet palette for water-based paint - Google Patents

Abstract

The invention relates to a wet palette for water-based paint that comprises a flat container (1) having a peripheral rim and, in its operational state, contains water (4). A water (4) retaining structure (2), preferably a sponge or foam, is placed in the flat container (1) and arranged so as to become impregnated and moistened by contact with and absorption of the water (4) contained in the flat container (1). A sheet of water-permeable paper (3) is positioned on the retaining structure (2) and, in its operational state, is in contact with the water-based paint (5) applied to an upper face of the sheet of paper (3). The sheet of paper (3) is a sheet of coated one side (C1S) paper having wet strength, i.e. a sheet of machine finished coated (MFC) paper or a sheet of cast coated paper, the coated upper face of which is used, in its operational state, as a support for the application of the water-based paint (5).

Description

WET PALETTE FOR WATER-BASED PAINT

TECHNICAL AREA

The present invention relates to a wet palette for water-based paint (hereinafter referred to as a "wet palette") which aims to prolong the life of a water-based paint during a painting session. or between painting sessions.

TECHNOLOGICAL BACKGROUND

In general, a wet palette comprises a box containing a foam or sponge saturated with water which, by capillarity, passes through a sheet of paper, for example parchment, on which a painting is positioned. The paint is then kept wet "in the open" during the painting session but also between painting sessions with a lid. Such a solution, in accordance with the preamble of claim 1, is for example described in US patent US 5,715,933 A or in US patent US 6,302,267 B1, the teaching of which is incorporated here by reference.

US Patent US 3,874,499 A discloses, with reference to Figures 1-8 thereof, various embodiments of an artist's palette which maintains water-based paints in a cool, workable condition during use or storage. . This palette includes a palette surface that provides a controlled amount of humidity to the paints applied thereon. A specific structure is provided, which comprises a paddle base member having a textured surface, supplied with water by means of a reservoir placed above the textured surface, and a cover sheet covering the major part of the textured surface . This coating sheet comprises an absorbent lower side, placed in contact with the textured surface, and a treated upper side, which is permeable to water, but substantially impermeable to the pigments of the water-based paints which are applied to the cover sheet. Water supplied to the textured surface from the reservoir passes by capillary action from the textured surface to the cover sheet and permeates the cover sheet to maintain a moisture level of the water-based paints. The sheet of coating can in particular consist of a permeable and water-resistant wallpaper whose upper surface is treated with a material permeable to water and preventing the permeation of the pigments contained in the water-based paints. In this case, an aqueous latex-based polymer emulsion is used to treat the upper surface of the cover sheet, which emulsion is applied in liquid form in order to form, after drying, a uniform layer on the upper surface of the sheet. of coating.

The solution described with reference to Figures 1 to 8 of US patent US 3,874,499 A therefore does not rely on the use of a wet palette comprising a water-retaining structure which is placed in a container filled with water and which is 'permeates and humidifies on contact with water, but on the use of a tank which must constantly supply water to the textured surface. This configuration is not adequate insofar as the water supply of the entire textured surface cannot be ensured in a uniform manner. This solution also requires that the covering sheet consisting of wallpaper be moistened beforehand before being placed on the textured surface, in particular by saturating the covering sheet with water on both sides using a damp sponge or running it under a faucet. The configuration of this palette is thus made more complex and its use more tedious and not very optimal.

American patent US 3,874,499 A also describes, with reference to its figure 9, another embodiment of an artist's palette which does not require a reservoir supplying a textured surface at the base of the covering sheet. According to this other embodiment, the reservoir and the textured surface are replaced by a water-retaining base structure, formed of a rigid water-absorbing material, which base structure is treated or coated on its bottom and its sides. side edges of waterproof material to contain water inside the base structure. This other pallet is used by previously supplying water to the base structure, through its upper face, and distributing the water inside the base structure, before applying the previously moistened covering sheet on the upper side of the basic structure. The solution described with reference to Figure 9 of US patent US 3,874,499 A therefore does not rely on the use of a wet pallet comprising a water-retaining structure which is placed in a container filled with water and which impregnates and humidifies on contact with water, but on the use of a basic structure combining the functions of container and water-retaining structure. Such a basic structure, moreover rigid, turns out in fact to be too complex and expensive to produce, which is not desirable, especially since it is necessary to periodically replace the water-retaining structure. .

The use of a wallpaper as described in the American patent US 3,874,499 A proves in any case to be unsuitable in practice, this type of paper having too high a weight, typically exceeding 120 g/m2 and possibly approaching or even exceeding 200 gsm. As explained above, the use of such a wallpaper therefore requires the covering sheet to be moistened beforehand and saturated with water before being able to apply the paint to the surface of this covering sheet, which makes its application not easy in practice.

The problem of the solutions of the state of the art comprising a water-permeable paper are multiple and depend on the papers used, which may have one or more of these defects. Laying the paper on the wet surface is difficult and very often the sheet of paper warps because the fibers of the paper in contact with the water relax.

In addition, relatively fragile, the paper ends up degrading to make small pieces of paper debris, like fine dust.

Depending on the paint, especially for very thin paint, 'swirling' the paint will cause it to penetrate the paper causing the wet layer to stain. In addition to losing paint, the sponge or foam is stained and the paper is slightly transparent, the work surface is therefore partially soiled and becomes unusable, making the paper difficult to clean and re-use. These papers therefore lead to overconsumption of paint, difficulty in cleaning and reusing these papers, and degradation of the sponges and foams. Depending on the papers used, in particular parchment papers, the paint or water tends to gather on the surface, making mixing and the use of palettes difficult. This is due to too low surface energy.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a wet palette capable of keeping the paint wet the longest during a painting session and also between painting sessions.

Another object of the present invention is to prevent the sheet of paper used as a humidifying support from deteriorating, which would alter the quality of the paint.

Yet another object of the invention is to prevent the paint and the pigments contained in the paint (in particular the finer ones) from penetrating into the sheet of paper, so as to make it more robust in use, or even to allow and facilitate its cleaning, if necessary, and its reuse in the best conditions.

An additional object of the invention is to provide a wet palette which also makes it possible to work with thin layers of paint.

In accordance with the invention, the wet palette for water-based paint comprises a flat container having a peripheral rim and which, in its operational state, contains water, a water-retaining structure, preferably a sponge or a foam, which retaining structure is placed in the flat container and arranged to become impregnated and moistened by the contact and absorption of the water contained in the flat container, and a sheet of water-permeable paper, positioned on the retaining structure, and which, in its operational state, is in contact with water-based paint applied to an upper face of the sheet of paper. A lid can be added and placed on the flat container, thus enclosing the retaining structure as well as the sheet of paper in order to preserve the paint between various painting sessions.

According to the invention, the sheet of paper is a sheet of one-sided coated paper - or "C1 S" paper ("coated one side" in Anglo-Saxon terminology) - which is resistant to the wet state ("REH"), paper which is normally used for labeling, in particular of glass or metal containers, and whose coated upper face is used, in its operational state, as a support for the application of water-based paint.

A variety of papers are commercially available, including varying degrees of water absorption and wet strength (WWR). The Applicant has conducted multiple tests in this regard using various types of papers, and coated one side (C1S) wet strength (REH) papers are found to be optimal candidates for application in the the invention due in particular to their good ability to absorb water (on the uncoated side), their good resistance in the wet state (REH), the adequacy of the level of water permeability of the coating, and their good degree of impermeability to the pigments usually contained in water-based paints. As mentioned above, coated one side (C1 S) wet strength (REH) papers are usually used for labeling operations, in particular glass or metal containers, for example for the labeling of bottles. of glass. In this context, the underside of these coated papers is not normally exposed to the environment, but typically coated with an adhesive allowing the application and adhesion of the paper to the container in order to form labels. To the Applicant's knowledge, the use of this particular type of paper in the context of a wet palette, namely as a humidifying support, has not been envisaged until now, even less described or suggested in the state of the art.

According to the invention, the sheet of one-sided coated paper (C1 S) is more particularly a sheet of machine-coated paper, or "MFC" paper ("Machine Finished Coated" in English terminology) or a sheet of chrome-coated paper, or "coated on chrome"("castcoated" in Anglo-Saxon terminology), namely a paper whose coating is carried out by means of a polished chrome cylinder which gives the coating a greater shine and a smooth surface. In a preferred embodiment, the sheet of one-sided coated paper (C1 S) has a weight defined according to the ISO 536 standard which is between 30 g/m ² and 100 g/m ² , preferentially between 50 g/m ² and 100 g/m ² .

Wet strength (REH) can be imparted to the paper during its manufacture by the addition of reinforcing fibers or by an appropriate treatment which makes it possible to prevent tearing and disintegration of the sheet of paper in water. .

In one embodiment, the sheet of one-sided coated paper (C1 S) is preferably a sheet of wood-free paper, which makes it possible to prevent any yellowing of the paper.

Even more preferably, the sheet of one-sided coated paper (C1 S) has a COBB60 absorption index measured according to the ISO 535 standard on the side of its lower face which is between 10 g/m ² and 25 g/m ² , as well as a dry tensile strength measured according to the ISO 1924-2 standard which is between 50 N/15mm and 100 N/15mm.

In one embodiment, the water-retaining structure is a smooth foam or sponge, in particular a polyvinyl alcohol (PVA) foam or a polyurethane foam, which has the required characteristics such as high absorption capacity, smooth surface limiting the development of mould.

The wet palette according to the invention can be used just as well with acrylic paint, gouache or any other type of water-based paint, such as watercolor.

It is also claimed to use a sheet of coated one side (C1 S) wet strength (REH) paper, namely a sheet of machine coated paper (MFC) or a sheet of coated chrome, as a moistening support for a wet palette for water-based paint, the coated side of said sheet of one-sided coated paper being used, in its operational state, as a support for the application of a paint with water, especially acrylic paint, gouache, or watercolor. This sheet of one-sided coated paper (C1 S) may preferably have the additional characteristics listed above. The invention also relates to a method for implementing a wet palette for water-based paint, in particular a wet palette according to the aforementioned embodiments, comprising the following steps: pouring water into a flat container comprising a peripheral rim then placing a water-retaining structure, preferably a sponge or a foam, in the flat container, or vice versa, the retaining structure becoming impregnated and moistened by contact and absorption of the water contained in the flat container; disposing a sheet of water-permeable paper on said retaining structure, the sheet of paper being a sheet of one-side coated (C1 S) wet-strength (REH) paper, namely a sheet of machine-coated paper ( MFC) or a sheet of chrome-coated paper, the coated upper face of which is used as a support for the application of water-based paint; and applying the water-based paint to the top, coated layer of the sheet of paper.

Other aspects of the invention are set out in the remainder of this description.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics and advantages of the invention will appear more clearly on reading the following detailed description of embodiments of the invention, which are presented solely by way of non-limiting examples and are illustrated by the appended drawings where the figure 1 shows an exploded view of a wet palette according to the present invention.

MODES FOR CARRYING OUT THE INVENTION

As illustrated in Figure 1, the wet palette comprises a flat container 1 having a peripheral rim which, in its operational state, contains water 4. A retaining structure 2 of water 4, preferably a flat sponge or foam , is placed in the flat container 1 to become impregnated and moistened by the contact and absorption of the water 4 contained in the flat container 1 . A sheet of paper 3 permeable to water is positioned on the retaining structure 2. In the operational state of the pallet, the sheet of paper 3 is in contact with a water-based paint 5, for example an acrylic paint, which is applied to the upper face of the sheet of paper 3. It will therefore be understood that the sheet of paper 3 acts here as a humidifying support making it possible to maintain the paint 5 in a wet state, while avoiding direct contamination by the paint 5 of the retaining structure 2.

According to the invention, the sheet of paper 3 is a sheet of one-sided coated paper, or "C1 S" paper, which is resistant to the wet state ("REH"), the upper side of which, coated, is used, in its operational state, as a support for the application of water-based paint 5. As already mentioned, this particular type of paper is known and available on the market, however for a completely different application, namely the labeling of plastic containers. glass or metal, in particular glass bottles. The use of such one-side coated (C1 S) wet-strength (REH) paper as a moistening support for a wet palette has not, to the Applicant's knowledge, been previously described or suggested in the state of the art.

In the example illustrated, it will be understood that the retaining structure 2 is saturated with water 4 by capillarity, and that the water passes through the sheet of paper 3 and hydrates the paint 5, here of the acrylic type. The paint is therefore kept wet in the "open sky" during the painting session, which allows it to be used for more than a few hours.

The use, according to the invention, of a sheet of coated paper on one side (C1 S) resistant to the wet state (REH) as a humidifying support for the wet palette offers the advantage that the sheet of paper 3 has a coating, on its upper face, intended to receive the water-based paint 5 and whose water permeability is comparatively less than the water permeability of the base of the sheet of paper 3 which is positioned in contact with the retaining structure 2. In addition, the coating offers a good degree of impermeability to the pigments contained in the water-based paint 5. This therefore results in a directional structure which ensures, on the one hand, good humidification of the paint 5 and prevents, on the other hand, the penetration of the pigments contained in the paint 5 into the sheet of paper 3, thus preventing soiling of this sheet of paper 3 and of the retaining structure 2 lying underneath. It turns out that the coated paper on one side (C1 S) resistant to the wet state (REH) is particularly suitable insofar as it also makes it possible to carry out a possible cleaning of the upper face of the sheet of paper 3 at the end of the painting session, and therefore a reuse of the sheet of paper 3, increasing the life of the sheet of paper 3 accordingly.

Preferably, the sheet of paper 3 is provided with a permeability at the level of the coating making it possible to work with paints 5 with very fine particles and pigments. In this context, the coating can in particular have a microporous structure which makes it possible to limit the absorption of the paint 5 and the pigments in the paper, while allowing the humidity to pass through.

Ideally, the sheet of paper 3 has a wet opacity (measured according to ISO 2471) that is greater than 80% so that the humidity does not negatively affect the visual appearance of the sheet of paper 3.

The retaining structure 2 can advantageously be a foam or a smooth sponge, in particular a polyvinyl alcohol foam (PVA) or a polyurethane foam, limiting the development of mould. An antifungal treatment of the sheet of paper 3 is in this respect also possible, even advisable.

The retaining structure 2 and the sheet of paper 3 preferably have identical shapes. In particular, the retaining structure 2 and the sheet of paper 3 can advantageously be embossed so as to create hydrating basins arranged to receive a paint 5, in particular liquid.

In contact with water, ordinary paper relaxes and warps. It becomes relatively brittle and crumbles over time. Small pieces of paper can end up in the paint. The sheet of paper 3 according to the invention makes it possible to avoid these drawbacks. A thin, uncoated sheet of paper would allow paint to penetrate, which would damage the retaining structure. According to the invention, the sheet 3 is made of a wet-strength paper (REH) in order to prevent the sheet of paper 3 from tearing and disintegrating in the water, which would render it unusable. This wet strength (WWR) can be achieved during papermaking by the incorporation of reinforcing fibers, for example synthetic, or by adding additives of the polyamide-amine-epichlorohydrin (PAE) type.

It is advantageous to use paper whose weight (defined according to the ISO 536 standard) is between 30 g/m ² , or even 50 g/m ² , and 100 g/m ² , depending on the paint 5 used. The upper face of the sheet of paper 3 is moreover printable, which in particular allows the possible printing of guides or patterns.

According to a particularly preferred variant embodiment, the sheet of paper coated on one side (C1S) has an absorption index COBB60 (measured according to standard ISO 535) on the side of its lower face, uncoated, which is between 10 g/ m ² and 25 g/m ² , as well as a dry tensile strength (measured according to standard ISO 1924-2) which is between 50 N/15mm and 100 N/15mm.

The sheet of one-sided coated paper (C1S) can more particularly be, in a first alternative embodiment, a sheet of machine-coated paper, or “MFC” paper (“Machine Finished Coated” in English terminology). An example of such a machine-coated paper is, for example, marketed by the company Feldmuehle GmbH (www.feldmuehle- under the designation SaxaSet® with a grammage of 70, 75 or 80 g/m ² (SaxaSet® being a registered trademark of Feldmuehle GmbH).

The sheet of one-sided coated paper (C1 S) can alternatively be, in a second embodiment, a sheet of chrome coated paper, or "coated on chrome"("castcoated" in Anglo-Saxon terminology), namely a paper whose coating is carried out by means of a polished chrome cylinder which gives the coating a greater shine and a smooth surface. An example of such a chrome-coated paper is for example marketed by the company Zanders Paper GmbH (www.zanders.com) under the designation Chromolux® 900 E with a weight of 80 or 90 g/m ² (Chromolux® being a trademark registered of Zanders Paper GmbH). This paper also has the advantage of being a wood-free paper, with high whiteness and good gloss on the coating side (i.e. a whiteness of around 89% according to ISO 2469 standard and a gloss greater than 57% according to ISO 8254-2), and which does not yellow and offers good robustness in use.

The above examples of one side coated (C1 S) wet strength (REH) papers are given for illustrative purposes and other papers of similar categories (machine coated or chrome coated) could be used, in particular depending on the properties of the water-based paint 5 used.

If necessary, the underside of the sheet of paper 3 could be additionally treated or coated with a light coating in order to stabilize the sheet of paper (and avoid for example a rolling up on itself or a stretching of the sheet of paper 3, in particular because of a differentiated absorption between the lower and upper faces) and/or in order to adjust the level of water absorption of the sheet of paper 3.

Of course, the wet palette according to the invention can also comprise a cover or other similar element making it possible to enclose the paint 5 hermetically outside the periods of the painting sessions when the artist is not painting.

It will generally be understood that various modifications and/or improvements obvious to those skilled in the art can be made to the embodiments described in the present description without departing from the scope of the invention defined by the appended claims.

In particular, the sheet of paper 3 can optionally be treated or coated with a light coating on its underside in order to adjust, if necessary, the degree of water absorption of the sheet of paper 3 and therefore the degree of humidity of this sheet, without this affecting the properties of the coating applied to the upper face where the paint is applied.

Finally, although reference has been made to the use of an acrylic paint, the wet palette according to the invention can be used together with any other type of water-based paint, in particular but not exclusively gouache or watercolor.

Claims

1 . Wet palette for water-based paint comprising: a flat container (1) having a peripheral rim and which, in its operational state, contains water (4); a retaining structure (2) for water (4), preferably a sponge or a foam, which retaining structure (2) is arranged in the flat container (1) and arranged to soak up and moisten by contact and the absorption of water (4) contained in the flat container (1); and a sheet of paper (3) permeable to water (4), positioned on said retaining structure (2), and which, in its operational state, is in contact with water-based paint (5) applied to an upper face of the sheet of paper (3), characterized in that the sheet of paper (3) is a sheet of one-side coated (C1 S) wet-strength (REH) paper whose upper face, coated is used, in its operational state, as a support for the application of the water-based paint (5), the sheet of one-side coated paper (C1 S) being a sheet of machine-coated paper (MFC) or a sheet of chrome coated paper. 2. Wet pallet according to claim 1, characterized in that a sheet of coated paper on one side (C1 S) has a basis weight defined according to the ISO 536 standard which is between 30 g/m ² and 100 g/m ² . 3. Wet pallet according to claim 2, characterized in that a sheet of one-sided coated paper (C1 S) has a basis weight defined according to the ISO 536 standard which is between 50 g/m ² and 100 g/m ² . 4. Wet pallet according to any one of the preceding claims, characterized in that the sheet of one-sided coated paper (C1 S) is a sheet of wood-free paper. 5. Wet pallet according to any one of the preceding claims, in which the sheet of one-sided coated paper (C1S) has a COBB60 absorption index measured according to the ISO 535 standard on the side of its lower face which is between 10 g /m ² and 25 g/m ² , as well as a dry tensile strength measured according to the ISO 1924-2 standard which is between 50 N/15mm and 100 N/15 mm. 6. Wet pallet according to any one of the preceding claims, in which the retaining structure (2) is a foam or a smooth sponge, in particular a polyvinyl alcohol (PVA) foam or a polyurethane foam. 7. Wet pallet according to claim 6, in which the retaining structure (2) is a polyvinyl alcohol foam (PVA) or a polyurethane foam. 8. Wet palette according to any one of the preceding claims, further comprising a cover arranged to be placed on the flat container (1) and enclose the retaining structure (2) as well as the sheet of paper (3) in order to preserve the painting between various painting sessions. 9. Use of one side (C1 S) coated wet strength (REH) sheet of paper, i.e. machine coated (MFC) sheet or chrome coated paper sheet, such as moistening support (3) of a wet palette for water-based paint, the coated side of said sheet of one-sided coated paper (C1S) being used, in its operational state, as a support for the application of a water-based paint water (5). 10. Use according to claim 9, characterized in that a sheet of one-sided coated paper (C1S) has a basis weight defined according to the ISO 536 standard which is between 30 g/m ² and 100 g/m ² . 11 . Use according to Claim 10, characterized in that a sheet of one-sided coated paper (C1 S) has a basis weight defined according to the ISO 536 standard which is between 50 g/m ² and 100 g/m ² . 12. Use according to any one of claims 9 to 11, characterized in that the sheet of one-sided coated paper (C1 S) is a sheet of wood-free paper. 13. Use according to any one of claims 9 to 12, in which the sheet of one-sided coated paper (C1 S) has an absorption index COBB60 measured according to the ISO 535 standard on the side of its lower face which is between 10 g/m ² and 25 g/m ² , as well as a dry tensile strength measured according to the ISO 1924-2 standard which is between 50 N/15mm and 100 N/15 mm. 14. Use according to any one of claims 9 to 12, for the application of acrylic paint, gouache, or watercolor. 15. A method of implementing a wet palette for water-based paint, in particular a wet palette according to any one of claims 1 to 8, comprising the following steps: pouring water (4) in a flat container (1) having a peripheral rim and then place a water-retaining structure (2), preferably a sponge or foam, in the flat container (1), or conversely, the water-retaining structure ( 2) becoming impregnated and moistened by contact with and absorption of the water (4) contained in the flat container (1); disposing a sheet of paper (3) permeable to water (4) on said retaining structure (2), the sheet of paper (3) being a sheet of coated paper on one side (C1 S) resistant to the wet state ( REH), namely a sheet of machine-coated paper (MFC) or a sheet of chrome-coated paper, the upper, coated face of which is used as a support for the application of water-based paint (5); and apply the water-based paint (5) to the upper, coated side of the sheet of paper (3).