DESC:FIELD OF INVENTION:

The present invention relates to a cost effective and environmentally friendlyself adhesive wall paper, coated with minimal adhesive material and the adhesive material layer is protected by a thin layer of water soluble film (WSF). The water soluble film provides easy, smooth movement and better coefficient of friction, faster dissolution as well as easy application on the wall surface. The invention also relates to a process for the preparation of cost effective and environmentally friendlyself adhesive wallpaper.

BACKGROUND OF INVENTION:

Traditionally, wall papers had a design on one side (face side) and an impervious substrate on the other side. This obverse side was coated with wet glue, during the time of application, and was done by workers skilled in the art of applying wall papers to the walls or floors. The other format for new wall paper which came to the market was having a coating of “wet glue” on the impervious side and the applicator expert had to unwind the WP roll, cut as per need, apply water, and fix it to the wall. It was understood that the application of water would “wet” the glue and make it tacky. Various attempts have been made to upgrade the “wet glue” to the modern pressure sensitive adhesive (PSA) coatings. This would look very similar to traditional self adhesive materials which consist of a substrate to be printed coated with an adhesive on one side and a silicone coated removable liner on the adhesive side, which is removed while applying the same or a pre-printed, pre cut design on a particular object/wall/floor/tile. When the silicone coated liner from the self adhesive material is removed, the adhesive material is exposed to open environment and the self adhesive material can then be applied simply by using specified pressure onto the front of the wall paper and the object to which it is expected to adhere.

All PSA (pressure sensitive adhesive) coated materials, also known as self adhesive materials must have a removable Liner —such as a silicone coated liner). Usually it is a type of Silicon coating that assists easy release. Removable films are selected from silicon coated papers, films, foils or fabrics. Silicon coating is done by application of solvent based/water based silicones. These are thermally cured or cured by Electron Beam or by UV radiation. Sometimes primer-coated papers are also used. Similarly films with or without primers, like polyester/polypropylene/PE (polyethylene)/HDPE (high density polyethylene) etc are also used for silicon coating. Most of these silicon coated liners are not biodegradable and so are not environmental friendly. Silicones coated with the aid of solvents are also adding to pollution.

Generally, wall papers are applied to a clean surface, after drying of the wall, optionally over the conventional putty covered smooth wall. Usually, wall papers are supplied in roll form, and are shaped into various sizes according to the requirement by the person skilled in the art of application. The application generally requires, applying water based or optionally, solvent based adhesive, to the wall and to the back side (obverse side) of the decorated wall paper. Wall papers are usually printed and available in various designs and colours.

273/MUM/2005 (WO2007015264) describes a process for preparation of liner-less self-adhesive materials and an apparatus and a method for applying the same liner–less self-adhesive material to an object. In WO2007015264, the self-adhesive material is protected by a protective layer which is a solution cast water-soluble substrate of thickness between 5 and 40 microns.

The disadvantage of using traditionally available wallpaper are that the affixing and application of water based adhesive, takes more than 48 hours to 96 hours to affix to the wall. During monsoons or in high humid climates, the affixing may even take longer. The wall papers remain affixed, till the strength of the adhesive or till the wall (to which it has been applied) remains dry. During monsoons or high humid climatic conditions, walls tend to “perspire” and sometimes, water seepage into walls, “lifts off” the wall paper (known as dog ears), at joints and becomes disjointed.

US5487929 relates to a decorative sheet material for applying to a wall, ceiling, floor, kitchen unit, table or other surface within domestic or industrial premises or place of amenity. In a preferred embodiment, this invention relates to wall coverings, such as wallpaper which utilize a pressure sensitive adhesive and a means to minimize initial adhesion of the wall covering to a wall. Maximum adhesion is subsequently attained after the wall covering has been repositioned as desired.

US2012/0061014 describes a self adhesive material comprising a face material coated with pressure sensitive adhesive which is protected with water-soluble protective layer of thickness less than 5 microns.

WO2015029049 describes linerless sheeting articles comprising a substrate, a pressure sensitive adhesive layer disposed on the substrate, and a water soluble protective layer disposed on the pressure sensitive adhesive layer.

Also, at the time of fixing a self adhesive material on a surface of an object, the removable liner is removed and the adhesive layer side of the self adhesive material is pressed on the surface of the object. But due to the nature of the PSA, crease formation and misalignment arises on the wallpaper. Such problems which arise while applying a self adhesive material to a surface is unavoidable, thereby resulting in a lot of wastage.

Further spreading of the adhesive material layer over the entire obverse surface of the wall paper leads to lot of wastage of the adhesive material. It has also been observed that spreading of the adhesive material layer over the entire obverse surface of the wall paper can also lead to usage of additional amount of the protective layer over the entire surface thereby increasing the cost of self adhesive wallpaper as also wastage of resources.

Therefore there is a need for a self adhesive wall paper, having a protective layer of water soluble film incorporated with surfactants, which will totally eliminate the need for removable films as also there is a need to minimize the usage of adhesive material and water soluble protective layer.

OBJECTS OF THE INVENTION:

It is an object of the invention to provide a self adhesive material with a water soluble protective layer wherein the adhesive material is provided on the obverse side of the substrate in segmented/patterned manner at discrete places.

It is an object of the invention to provide a self adhesive material, which eliminates the usage of liner, by providing a protective layer of water soluble film incorporated with surfactants and/or fillers that can be easily applied on the surface of an object.

It is yet another object of the invention to provide a self adhesive material which can be directly applied onto the desired object by sprinkling water onto the adhesive layer and thereby does not require the need of removal of liner layer.
It is yet another object of the invention to provide a self adhesive material, which does not create any liner disposable problem.

It is another object of the invention to provide a self adhesive wall paper which minimizes the usage of adhesive material and water soluble protective layer.
It is another object of the invention to provide a eco- friendly wall paper which is also economical.

It is yet another object of the invention to provide upgraded quality of wall paper such that the wall paper is not adversely affected by inherent or additional moisture in the walls, thereby avoiding the formation of “dog ears” or peeling off of the decoration/decorative wall paper.

It is yet another object of the invention to provide a convenient process for the application/ mounting of the wall paper onto the walls without the need of adhesive expert/specialists..

It is yet another object of the invention to provide a wall paper which consumes less adhesive material and sticks efficiently, without compromising its adhesion values.

It is yet another object of the invention to provide a wall paper with reduced self adhesive material by placing the pressure sensitive adhesive on the obverse side of the wallpaper in segmented/patterned manner at discrete places.

It is yet another object of the invention to provide a process for the preparation of a wall paper with reduced self adhesive material by placing the self adhesive material on the obverse side of the wallpaper in segmented/patterned manner at discrete places.

It is yet another object of the invention to provide a wall paper which consumes less water soluble film material, without compromising the safety of the adhesive material.

It is yet another object of the invention to provide a wall paper with reduced self adhesive material and reduced water soluble film by optionally placing the water soluble film in segmented/patterned manner at discreet places.

It is yet another object of the invention to provide a process for the preparation of a wall paper with reduced self adhesive material and reduced water soluble film by optionally placing the water soluble film in segmented/patterned manner at discreet places.

It is yet another object of the invention to provide an apparatus and a method for applying self adhesive material on an object such as wall as decorative purpose.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided a self adhesive wallpaper comprising a substrate, pressure sensitive adhesive layer coated onto the obverse side of the said substrate, and a protective layer of water soluble film substantially coating the pressure sensitive adhesive layer wherein the pressure sensitive adhesive layer is coated over the obverse side in a discontinuous manner preferably in a patterned/beaded/segmented form.

According to one aspect of the present invention there is provided a self adhesive wallpaper comprising a substrate, pressure sensitive adhesive layer coated onto the obverse side of the said substrate, and a protective layer of water soluble film substantially coating the pressure sensitive adhesive layer wherein the water soluble film layer is optionally provided only over the pressure sensitive adhesive layer in patterned/beaded/segmented form.

According to yet another aspect of the present invention there is provided a process for the preparation of a self adhesive wallpaper with reduced self adhesive material by placing the self adhesive material on the obverse side of the wallpaper in patterned/beaded/segmented form at discrete places.

According to yet another aspect of the present invention there is provided a process for the preparation of self adhesive wallpaper with reduced self adhesive material and reduced water soluble film by optionally providing the water soluble film in patterned/beaded/segmented form at discrete places.

DETAILED DESCRIPTION OF THE INVENTION:
The following detailed description illustrates the invention by way of examples and not by way of limitation. The following description provides the best mode of carrying out the present disclosure and enables one skilled in the art to make and use the invention claimed in the present disclosure.

The present invention relates to a cost effective and environmentally friendlyself adhesive wall paper, coated with minimal adhesive material and having a protective layer of water soluble film. The usage of protective layer of water soluble film avoids the need of laminating the adhesive material with an additional coating of removable film material like silicon..

The water soluble film provides easy, smooth movement and better coefficient of friction, faster dissolution as well as easy application on the wall surface.
The invention also relates to a process for the preparation of cost effective and environmentally friendlyself adhesive wallpaper.

The present invention provides a self adhesive material, comprising a face material coated/applied with pressure sensitive adhesive (PSA) on its one surface and a protective layer of water soluble film (WSF), incorporated with surfactants and/or fillers, laminated on the adhesive side of the said face material wherein the adhesive material is placed in patterned/beaded/segmented form at discrete places on the obverse side of the substrate.

This invention also provides a self adhesive material, comprising a face material coated/applied with pressure sensitive adhesive (PSA) on its one surface and a protective layer of water soluble film (WSF), incorporated with surfactants and/or fillers, laminated on the adhesive side of the said face material wherein the WSF layer is optionally placed in patterned/beaded/segmented form at discrete places.

The present invention in particular relates to Self Adhesive wall paper, with a water soluble film (WSF) coating, said water soluble film (WSF) coating “protects” the PSA till it is exposed, during the end use. The present invention primarily focus on being cost effective, by using water soluble film, thereby avoiding the use of Silicon Coated backing paper/substrate. The present invention also focuses on being cost effective by minimizing the usage of adhesive material on the obverse side of wall paper by providing the same in a segmented/patterned manner at discreet places on the obverse side of the wallpaper.

The present invention further also focuses on being cost effective by minimizing the usage of water soluble film (WSF) coating by optionally providing the same in a segmented/patterned manner.

The present invention uses different types of wallpaper which can be selected from wood, vinyl, Metallic, fabrics (woven & non-woven), Glass bead, leather and the like. However the above list of wallpaper is by no means limiting.

Adhesive materials used in this invention and which are also referred to as Pressure-sensitive adhesive (PSA, self-adhesive, self-stick adhesive) are adhesive which forms a bond when pressure is applied to the adhesive with the adherend. It is used in pressure-sensitive tapes, labels, glue dots, note pads, automobile trim, and a wide variety of other products. As the name "pressure-sensitive" indicates, the degree of bond is influenced by the amount of pressure which is used to apply the adhesive to the surface. Surface factors such as smoothness, surface energy, removal of contaminants, etc. are also important to proper bonding.

PSAs are usually designed to form a bond and hold properly at room temperatures. PSAs typically reduce or lose their tack at low temperatures and reduce their shear holding ability at high temperatures; special adhesives are made to function at high or low temperatures. It is important to choose an adhesive formulation which is designed for its intended use conditions.
The PSA is selected from any type of adhesive made from resins or polymers or copolymers of acrylics, rubber, hot melt, EVA. starch, polyurethane and the like which are soluble in organic/inorganic/hydrocarbon solvents or water which can be tabulated as follows:

Types of Wallpaper Adhesives
Curing type Carrier base Eg.
Drying Adhesives Solvent based Natural rubber, Acrylic
Water based Acrylics, Starch, PVA, Cellulose
Hot Melt Adhesives Solvent Less Acrylic/ SIS/ SBS/ Bituminous/ EVA
Presur Sensitive Adhesive (PSA) Solvent based Natural/ Synthetic rubber, Acrylic, Nitryle
Water based Natural/ Synthetic rubber, Acrylic
Moisture curing Cyano acrylate

However the above list of PSA is by no means limiting.

The said protective layer formed of WSF is made of film forming materials selected from polyvinyl alcohol copolymer ionomers, polyvinyl alcohol homopolymer, non-ionomeric poly vinyl alcohol polymer, polymethacrylate, polyvinyl alcohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid or polyurethane, polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch, gum arabic, pullulan or dextrin or water-soluble cellulose derivatives such as methyl cellulose, hydroxylpropyl cellulose, hydroxylpropyl methyl cellulose, hydroxylpropylethyl cellulose, hydroxy ethyl cellulose or carboxylmethyl cellulose or combination thereof. The said protective layer formed of WSF is incorporated with surfactants selected from anionic based surfactants, cationic based surfactants such as cetylpyridinium chloride; ampholytic surfactants like dodecyl betaine, dodecyl dimethylamine oxide; nonionic surfactants like alkyl polyethylene oxide, alkyl polyglucosides or a combination thereof. However the above list of WSF and surfactants is by no means limiting.

The said protective layer formed of WSF is incorporated with fillers selected from calcium carbonate, titanium dioxide, zinc oxide and the like. However the above list of fillers is by no means limiting.

Accordingly the present invention discloses a self adhesive wall paper, in which the said face material side of the laminate is printed with desired matter or graphic. The present invention relates to Self Adhesive wall paper, coated with a water soluble film (WSF) coating, said water soluble film (WSF) coating “protects” the PSA till it is exposed, during the end use. The Self Adhesive wall paper, with a water soluble film (WSF) coating is applied by applying water on the back surface of the laminate and thereby expose the water soluble film and affixing the same on the desired location/wall.

After application, “dog ears” or “puffed surface” were not observed in humid climates, as the PSA is engineered in such a way that it affix to walls, including putty covered walls or tiles, and once applied becomes hydrophobic. Once the water is squeezed out, the wall paper properly fixes to the wall, as PSA is activated to take the permanent “grip” and affixes to the wall, and it remains affixed for much longer than the traditional PVAC or other types of adhesives.

Further the problem associated with crease formation is solved by the present invention, as the printed face material/wall paper could be adjusted/repositioned properly because of the nature of the wallpaper that also help in faster breakage and dissolution of the film.

Further, disposal of silicon based removable films are avoided, thus making the wallpaper eco-friendly.

The present invention also relates to a process for the preparation of a wall paper with reduced self adhesive material by placing the self adhesive material on the obverse side of the wallpaper in segmented/patterned manner at discrete places.
The non-limiting process steps involved are as follows:
Process 1
a. Take a wall Paper Face Material
b. Printing of adhesive on Wall Paper face material by Screen Printing or Gravure or any other process to obtain wallpaper with adhesives as shown in Figure 2
c. Drying
d. Lamination of Water Soluble Film on adhesive layer to obtain wallpaper embossed with adhesives and WSF.
e. Drying
f. Self Adhesive Wall Paper as shown in Figure 1Bis ready

The present invention also relates to a process for the preparation of a wall paper with reduced self adhesive material and reduced water soluble film by optionally providing the water soluble film in segmented/patterned manner at discreet places where in the process steps are as follows:
Process 2
a. Take a wall Paper Face Material
b. Printing of adhesive on Wall Paper face material by Screen Printing or Gravure or any other process to obtain wallpaper with adhesives as shown in Figure 2
c. Drying
d. Printing of Water Soluble Film on adhesive by Screen printing or Gravure or any other Process to obtain wallpaper embossed with adhesives and WSF as shown in Figure 3
e. Drying
f. Self Adhesive Wall Paper as shown in Figure 1A is ready

Figure 1A is a cross-sectional view of embodied Wallpaper comprising both adhesive layer and Water soluble film layer in continuous form;
Figure 1B is a cross-sectional view of embodied Wallpaper comprising adhesive layer in patterned form and Water soluble film layer is also in patterned form;
Figure 2: Self adhesive wallpaper embossed with adhesive in pattern form;
Figure 3: Self adhesive wallpaper embossed with adhesive and wherein adhesive part is specifically coated with Water soluble film.

In Figure 1A and 1B, (1) refers to water soluble film, (2) refers to adhesive layer and (3) refers to face wall paper.

The present invention has been briefly described with the above mentioned reference purely for the sake of understanding and not by way of any limitation and the present invention includes all legitimate developments within the scope of what has been described herein before.

,CLAIMS:We claim
1. A self adhesive wallpaper comprising a substrate, pressure sensitive adhesive layer coated onto the obverse side of the said substrate, and water soluble film layer coating the pressure sensitive adhesive layer wherein the pressure sensitive adhesive layer is coated over the obverse side in continuous or in discontinuous manner in a patterned/beaded/segmented form.
2. A self adhesive wallpaper comprising a substrate, pressure sensitive adhesive layer coated onto the obverse side of the said substrate, and water soluble film layer coating the pressure sensitive adhesive layer, wherein the water soluble film is optionally provided in a manner sufficient to coat only the pressure sensitive adhesive layer.
3. A self adhesive wallpaper/label/material as claimed in claim 2 wherein the water soluble film layer is coated optionally in patterned/beaded/segmented form over the pressure sensitive adhesive layer.
4. A self adhesive wallpaper/label/material as claimed in any one of the preceding claim, wherein the wall paper/label/material is selected from wood, vinyl, Metallic, fabrics (woven & non-woven), Glass bead, leather and the like
5. A self adhesive wallpaper/label/material as claimed in any one of the preceding claim, wherein the pressure sensitive adhesive material is selected from drying adhesives such as solvent based natural rubber , acrylic adhesive and water based acrylic, starch , PVA, cellulose adhesive, hot melt PSA such as solvent less acrylic/ SIS/ SBS/ Bituminous/ EVA, pressure sensitive adhesive such as solvent based natural/ synthetic rubber, acrylic, nitrile, water based natural/ synthetic rubber, acrylic, moisture curing adhesive such as cyano acrylate.
6. A self adhesive wallpaper/label/material as claimed in any one of the preceding claim, wherein the water soluble film material is selected from—film forming materials such as polyvinyl alcohol copolymer ionomers, polyvinyl alcohol homopolymer, non-ionomeric poly vinyl alcohol polymer, polymethacrylate, polyvinyl alcohol, polyacrylamide, polymethacrylamide, polyacrylic acid, polymethacrylic acid or polyurethane, polyethyleneglycol, polyvinylpyrrolidone, proteinaceous binders such as gelatin, modified gelatins such as phthaloyl gelatin, polysaccharides such as starch, gum arabic, pullulan or dextrin or water-soluble cellulose derivatives such as methyl cellulose, hydroxylpropyl cellulose, hydroxylpropyl methyl cellulose, hydroxylpropyl ethyl cellulose, hydroxy ethyl cellulose or carboxylmethyl cellulose or combination thereof., surfactants such as anionic based surfactants, cationic based surfactants such as cetylpyridinium chloride; ampholytic surfactants like dodecyl betaine, dodecyl dimethylamine oxide; nonionic surfactants like alkyl polyethylene oxide, alkyl polyglucosides or a combination thereof. and fillers such as calcium carbonate, titanium dioxide, zinc oxide and the like.
7. A self adhesive wallpaper/label/material as claimed in any one of the preceding claim, wherein the thickness of the adhesive layer is ranging from 15 microns to 60 microns, preferably from 20 to 45 microns, more preferably from 25 microns to 35 microns and the thickness of the water soluble film layer is less than 3 microns more preferably less than 2 microns.
8. A process for the preparation of a self adhesive wallpaper with reduced self adhesive material by placing the self adhesive material on the obverse side of the wallpaper in patterned/beaded/segmented form at discrete places.
9. A process for the preparation of a self adhesive wallpaper comprising self adhesive material in patterned/beaded/segmented form at discrete places comprising the steps of:
a. Take a wall Paper Face Material;
b. Printing of adhesive on Wall Paper face material by Screen Printing or Gravure or any other process to obtain wallpaper embossed with adhesives as shown in Figure 2;
c. Drying;
d. Lamination of Water Soluble Film on the adhesive layer to obtain wallpaper embossed with adhesives and WSF;
e. Drying to obtain Self Adhesive Wall Paper as shown in Figure 1B.
10. A process for the preparation of a self adhesive wallpaper with reduced water soluble film layer by coating the water soluble film layer only over the patterned/beaded/segmented form of pressure sensitive adhesive layer.
11. A process for the preparation of a self adhesive wallpaper comprising water soluble film layer in patterned/beaded/segmented form at discrete places on the adhesive layer comprising the steps of:
a. Take a wall Paper Face Material;
b. Printing of adhesive on Wall Paper face material by Screen Printing or Gravure or any other process to obtain wallpaper embossed with adhesives as shown in Figure 2;
c. Drying;
d. Printing of Water Soluble Film on adhesive by Screen printing or Gravure or any other Process to obtain wallpaper embossed with adhesives and WSF as shown in Figure 3;
e. Drying to obtain self Adhesive Wall Paper as shown in Figure 1A.