SECURITY ELEMENT/PRODUCT OBTAINED THEREFROM

FIELD OF THE INVENTION

The present invention relates to a security element or a security product. The security element or security product can be in the form of substrates. In particular, the present invention relates to a method for manufacturing a security element or security product and a security element or security product obtained therefrom. A specific example of the security element or security product is a security thread. The present invention provides an alternative solution for manufacturing of the security thread.

BACKGROUND OF THE INVENTION

In the contemporary world, the use of digital technology is inevitable. Every day the digital technology is becoming powerful and is developing rapidly. For example, devices such as processors for computers, the computers themselves, printers, photocopiers, and the like are becoming faster, powerful, smaller, and cheaper which allows them to be easily available. Further, these devices are being developed such that they are simple, and easy to operate and use, which is a boon to humans.

However, on the other hand, these very devices can be and are being misused for various ill- legal activities such as counterfeiting of currency notes, important documents, which may include documents such as passports, identification cards, and the like. Such use of these devices may lead to grave security breaches which is visibly not looked-for.

In the known art, in order to secure the currency notes, and important documents, one or more security features are added. The security features may include one or more features which are difficult or impossible to reproduce using the above-mentioned powerful devices.

EP 1467873 Bl (referred to hereinafter as EP ‘873) discloses methods for manufacturing substrates for use in varying shapes and sizes for various authenticating or security applications. FIG. 3 (see the accompanying drawing) illustrates a cross-sectional view across the width of an authenticating device manufactured in accordance with the methods disclosed in EP ‘873. The method of manufacturing the substrate (10) includes the steps of firstly applying a layer of resist (13) to some portions of a metallic layer (12). The metallic layer (12) is deposited at least a portion on a first side of a transparent polymeric film (11). The areas of the metal that are not covered by the resist (13) are removed to form de-metallized regions. Further, a layer of polymeric liquid crystal material (15) is applied onto the resist (13) and the de-metallized regions, and the resist (13) is darkly coloured which masks the underlying metal areas which gives rise to a color change effect in the areas covered by the polymeric liquid crystal material (15) on viewing in reflection from the first side. EP ‘873 however has the drawback that if it is required to use different coloured resist on board of the same security element in order to modify the final appearance of the color change effect in reflection view, print register tolerances may be introduced in the layout of the security feature. This may impact, for example, the alignment of the metal free areas realized with the different coloured resist.

WO 2016/177391 Al (referred to as WO ‘391 hereinafter) discloses a security element that improves the protection against forgery. The security element of WO ‘391 may be in the form of strips or patches and can be used in connection with currency notes, official and unofficial documents such as the passports, ID-cards, bank and credit cards, checks, paper, coupons vouchers, tickets, packages.

In particular, the security element of WO ‘391 includes a transparent film. The security element further includes a pattern of transparent and non-transparent regions formed on a first side of the transparent film and a pattern of transparent and non-transparent regions formed on a second side of the transparent film. The two patterns one the first and second side of the transparent film match with each other. The security element also includes a color changing layer covering the pattern on at least one side of the film.

WO ‘391 however has the drawback that, using this kind of structure for security elements having magnetic properties, the metal layer results on the same side where the magnetic areas are also printed and, if proper protection is not guaranteed, the interaction between the metal layer and the metal oxides included in the magnetic ink generate corrosion effects which damage the security element.

WO 2019/219234 Al (referred to as WO ‘234 hereinafter) discloses a method for production of a security element. The security element includes a transparent substrate film, a metal layer with holes arranged in a certain pattern, a black Photo-sensitive layer (light absorbing layer), deposited on the metal layer, which has openings and register with the gaps of the metal layer, and over it has a full-surface, also the openings and gaps covering color effect layer.

The method for producing a security element includes the steps of applying a washing ink on a substrate at locations where the metal layer is to have the gaps, the metal film being completely coated on the substrate. The washing ink being applied and removed in the gaps, over the metal layer. The black photo-sensitive layer (light-absorbing layer), is applied so that it also covers the gaps in the metal layer, which generates openings in the light layer. A color effect layer is applied over the black photo-sensitive layer (light-absorbing layer), thereafter.

WO ‘234 however has the drawback that the absence of a resist layer on the top of the metal layer may generate a weakness on the security element when subjected to the chemical and physical tests usually required in the technical specifications. Accordingly, there is felt a need to provide security elements that are relatively simple and at the same time are secure and are not easy to copy or counterfeit. Further, a relatively and simple method of manufacturing the security elements is also desired.

OBJECTS OF THE INVENTION

An object of the present invention is to solve one or more deficiencies encountered in the prior art or to at least deliver a beneficial substitute.

Another object of the present invention is to provide a method for manufacturing a security element or a security product with more validating and/or security features; and

Yet another object of the present invention is to provide a security element or a security product with one or more validating and/or security features.

Other objects and benefits of the present invention will be more apparent from the following description, which is not intended to bind the scope of the present invention.

SUMMARY OF THE INVENTION

The present invention relates to a security element or security product, which may be in form of a substrate. In particular, the present invention relates to a method for manufacturing a security element or security product and a security element or security product obtained therefrom.

In accordance with one aspect of the present invention, a method for manufacturing a security element or security product with colour change effect with patterns configured thereon is disclosed.

The method comprising the steps of providing a polymeric film having a first operative surface and a second operative surface opposite to the first operative surface, wherein the polymeric film is transparent.

Thereafter, depositing by any known methods, a metal layer on full surface of the polymeric film in contact with the second operative surface of the polymeric film, the metal layer having a first operative surface in contact with the second operative surface of the polymeric film, and a second operative surface.

This is followed by printing a protective resist mask on selected areas of the second operative surface of the metal layer, selected areas defining covered areas and uncovered areas, the protective resist mask having a first operative surface in contact with the second operative surface of the metal layer and a second operative surface. The uncovered area patterns are in the shape or form of text or symbols which includes letters, numbers, pictures, image, photographs etc., or combinations of thereof. The protective resist mask preferably is transparent.

This is followed by the step of removing metal from the uncovered areas from the metal layer by etching process using a chemically acidic or basic solution to obtain an etched metal layer or demetallized layer defining demetallized areas on the metal layer, wherein the demetallized areas are transparent, and remaining areas which are not etched are opaque or non-transparent due to presence of metal on these areas.

Further, this is followed by the step of depositing a photosensitive layer on the full surface obtained after processing of protective resist mask layer in above step, wherein the photosensitive layer having a first operative surface, and a second operative surface, wherein the first operative surface is in contact with the second operative surface of the protective resist mask and on demetallized transparent areas, of the metal layer. The photosensitive layer functions as a light absorbing layer.

Thereafter, curing of the photosensitive layer is carried out to obtain a cured photosensitive layer, followed by irradiating the cured photosensitive layer with an ultraviolet light from the side of the first operative surface of the polymeric film to obtain an irradiated photosensitive layer, wherein the ultraviolet light incident onto the photosensitive layer only through de-metallized areas, which being transparent to ultraviolet light, and ultraviolet light cannot affect the areas of the cured photosensitive layer, wherein the metal layer is not demetallized or is non-transparent.

This is followed by etching those areas of the irradiated photosensitive layer exposed to the ultraviolet light by using a chemically acidic or basic solution corresponding to the uncovered areas defining covered areas and uncovered areas of the irradiated photosensitive layer so as to achieve transparent areas in metal and photosensitive layers which are in perfect register with each other resulting in areas which are transparent from up to both inclusive.

A polymeric liquid crystal layer is depositing or transfer coating over the processed layer of photosensitive layer such that both the covered areas and the uncovered areas of the photosensitive layer are covered by the polymeric liquid crystal layer followed by drying the same by hot air to obtain dried polymeric liquid crystal layer.

The so obtained polymeric liquid crystal layer is dried by irradiating with ultraviolet light to obtain an oriented polymeric liquid crystal layer, thereby forming a film having a plurality of security elements. The security element is having the pattern in the shape or form of text, or symbols, wherein the symbols including letters, numbers, pictures, digital images, photographs, and combinations thereof, as a predefined security feature, or requested by the end user or customer.

The film so obtained is slitted into a continuous thread of any width, or length or cut into geometrical shapes with different designs and sizes, or punched into shapes of different designs and sizes to obtain the security element product or article.

The so obtained security element colour change effect is observed when the security element is viewed at different viewing angles from the side of coating of the polymeric liquid crystal layer. The colour change effect being visible only in the portion of the security element where patterns are not configured in the security elements or in the portion area of the security element where metal layer remains along with the black photosensitive ink within the security element and the colour change effect being not visible in the transparent area.

Further, by changing the composition of the polymeric liquid crystal layer, different colour combinations being achieved in the security element.

In accordance with one embodiment of the present invention, the polymeric film is a polyethylene terephthalate film, and having a thickness in the range of 6 pm to 30 pm.

In accordance with one embodiment of the present invention, the metal layer is made of a metal selected from the group consisting of aluminium, steel, copper (Cu), and combinations thereof, and having a deposit in the range of optical density of not less than 2 or minimum 400 Angstrom unit.

In accordance with one embodiment of the present invention, the protective resist mask is made of coloured resist material other than black colour.

In accordance with one embodiment of the present invention, the photosensitive layer is made of photosensitive black ink.

In accordance with one embodiment of the present invention, the curing of the photosensitive layer is achieved by employing hot air preferably in the temperature range of 80 °C to 90 °C.

In accordance with one embodiment of the present invention, the photosensitive layer is irradiated with ultraviolet light from the polymeric film side.

In accordance with one embodiment of the present invention, the polymeric liquid crystal layer is deposited by printing or transfer coating from a carrier.

In accordance with another embodiment of the present invention, a security element is disclosed. The security element or product having a polymeric film having a first operative surface, and a second operative surface opposite to the first operative surface, the polymeric film being transparent, a metal layer disposed on the polymeric film, the metal layer having a first operative surface, and a second operative surface, the second operative surface being in contact with the first operative surface, wherein the metal layer on the polymeric film having de-metallised portion at predefined positions, the metal layer defines transparent de-metallised areas in the shape or form of patterns, the patterns being in the form or shape of text or symbols, the symbols including letters, numbers, pictures, image, digital photographs, and combinations thereof, and adjacent metallised nontransparent areas, a protective resist mask layer deposited on the metal layer, wherein the protective resist mask having a first operative surface, and a second operative surface, the second operative surface being in contact with the first operative surface patterns configured in the shape or form of text or symbols, the symbols including letters, numbers, pictures, image, digital photographs, and combinations thereof registering with the pattern of the text, and symbols of the metal layer, a photosensitive layer disposed on said protective resist mask, the photosensitive layer having a first operative surface, and a second operative surface, the second operative surface being in contact with the first operative surface, patterns in the shape or form of text or symbols, the symbols including letters, numbers, pictures, image, photographs, and combinations thereof registering with the patterns of text, symbols, of the protective resist mask, and a polymeric liquid crystal layer deposited on the photosensitive layer the polymeric liquid crystal layer having a first operative surface, and a second operative surface, the first operative surface being in contact with the second operative surface, the polymeric liquid crystal layer covering both the non-transparent areas and transparent areas.

The colour change effect in the security element is only visible or observed at the different view angle from the polymeric liquid crystal layer side only, and the colour changing effect which being visible at different view angle having patterns in the shape or form of text or symbols, wherein the symbols including letters, numbers, pictures, image, photographs, and combinations thereof.

In accordance with one embodiment of the present invention, the polymeric film is made of polyethylene terephthalate.

In accordance with one embodiment of the present invention, the metal layer comprising a metal selected from the group consisting of aluminium, steel, copper (Cu) and combinations thereof, and having a thickness in the range of minimum optical density of 2 or maximum optical density of 400 Angstrom units.

In accordance with one embodiment of the present invention, the protective resist mask layer is transparent or coloured.

In accordance with one embodiment of the present invention, the photosensitive layer is made of photosensitive black ink.

In accordance with one embodiment of the present invention, the different colour combinations are achieved by changing the composition of the polymeric liquid crystal layer.

In accordance with one embodiment of the present invention, the security element product is in the form of a thread, piece of any predefined geometrical shapes, and with dimension as per user requirement.

In accordance with one embodiment of the present invention, the security element having predefined thickness as per the end use.

In accordance with one embodiment of the present invention, the security element incorporated in a document, and product of value, the product of value being one of currency notes, passport papers, stamp paper, tax stamp papers, cheque, packaging, and labels. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

The present invention will now be described with the help of the accompanying drawing, in which:

FIG. la illustrates a schematic cross-sectional view of a security element with a polymeric film and a metal layer deposited thereon by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention;

FIG. lb illustrates a schematic cross-sectional view of the security element of FIG. la with a protective mask selectively deposited on the metal layer by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention;

FIG. 1c illustrates a schematic cross-sectional view of the security element of FIG. lb with the metal layer being selectively removed by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention;

FIG. Id illustrates a schematic cross-sectional view of the security element of FIG. 1c with a photo-sensitive layer preferably black (or light-absorbing layer), deposited on the protective mask layer by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention;

FIG. le illustrates a schematic cross-sectional view of the security element of FIG. Id with the photo-sensitive layer preferably black (or light-absorbing layer), being selectively etched by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention;

FIG. If illustrates a schematic cross-sectional view of the security element of FIG. le with a color effect layer being deposited on the selectively etched photo-sensitive layer (or light-absorbing layer), and the polymeric film on the de-metallized portion by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention;

FIG. 2 illustrates a flow chart of method for manufacturing of a security element in accordance with an embodiment of the present invention; and

FIG. 3 illustrates a cross-sectional view across the width of a conventional authenticating device.

LIST OF NUMERALS

The following is the list of numerals and their meaning as used in the present specification.

100 Security element

102 polymeric film 102a - First operative surface of the polymeric film

102b - Second operative surface of the polymeric film

104 - Metal layer

104a - First operative surface of the metal layer

104b - Second operative surface of the metal layer

104c - Metal elements

104cl - Non-transparent areas

104c2 - Transparent areas

104e - Etched metal layer

104f - Demetallized areas

106 - Protective resist mask

106a - First operative surface of the protective resist mask

106b - Second operative surface of the protective resist mask

106c - Text, symbols, or patterns the protective resist mask

106d - Covered areas

106e - Uncovered areas

108 - Photo-sensitive layer preferably Black (light-absorbing layer)

First operative surface of the Photo-sensitive layer preferably Black (light- 108a absorbing layer)

Second operative surface of the Photo-sensitive preferably Black layer 108b

(light-absorbing layer)

Text, symbols, or patterns on the Photo-sensitive preferably Black layer 108c

(light-absorbing layer)

Selectively removed Photo-sensitive layer preferably Black (light- 108r absorbing layer)

110 - Color effect layer

110a - First operative surface of the color effect layer

110b - Second operative surface of the color effect layer

S - Selective portion

R - Rest of portion

Md - Metal deficient region

Mr - Metal rich region

Direction from where Ultraviolet (U.V.) light radiate during

X manufacturing process

Y View side of security element for Color change effect

DETAILED DESCRIPTION The present invention will be described with reference to the accompanying embodiments and drawing, which do not limit the scope and realm of the present invention. The description delivered herein is merely by way of example and illustration.

The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments and drawings in the following description. Descriptions of the components and processing techniques, which are known in the art, are omitted so as not to unnecessarily obscure the embodiments herein. The examples used herein are projected simply to enable an understanding in which the embodiments herein may be accomplished and to further allow a person having ordinary skill in the art to exercise the embodiments herein. Accordingly, the examples must not be interpreted as restricting the scope of the embodiments presented herein.

The description that follows the specific embodiments, fully disclose the overall nature of the embodiments provided herein, that others can, by applying present knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the wording or language employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with alteration within the essence and scope of the embodiments as described herein.

In accordance with the present invention a method for manufacturing a security element is disclosed. The present invention also relates to a security element obtained by employing the method of the present invention.

The present invention is described with reference to the accompanying drawing, wherein FIG. la illustrates a schematic cross-sectional view of a security element with a polymeric film and a metal layer deposited thereon by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention, FIG. lb illustrates a schematic cross- sectional view of the security element of FIG. la with a protective mask selectively deposited on the metal layer by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention, FIG. 1c illustrates a schematic cross-sectional view of the security element of FIG. lb with the metal layer being selectively removed by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention, FIG. Id illustrates a schematic cross-sectional view of the security element of FIG. 1c with a photosensitive layer preferably black (or light-absorbing layer), deposited on the protective mask layer by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention, FIG. le illustrates a schematic cross- sectional view of the security element of FIG. Id with the photosensitive layer preferably black (or light-absorbing layer), being selectively etched by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention, FIG. If illustrates a schematic cross-sectional view of the security element of FIG. le with a color effect layer being deposited on the selectively etched photosensitive layer (or light-absorbing layer), and the polymeric film on the de-metallized portion by employing the process/method steps of manufacturing the security element in accordance with embodiments of the present invention, FIG. 2 illustrates a flow chart of method for manufacturing of a security element in accordance with an embodiment of the present invention, and FIG. 3 illustrates a cross-sectional view across the width of a conventional authenticating device.

In accordance with an aspect of the present disclosure, a security element (100) is disclosed. In accordance with the embodiments of the present invention, all the layers of the security element (100) are placed and configured on one side of the transparent polymeric film. This single side coating of different layers gives sturdy effect to the security element (100) with respect to the chemical and physical properties including durability. This sturdiness effect is because of cross-linking of different layers on one side of the transparent polymeric film. In accordance with one embodiment of the present invention, the security element (100) can be in the form of a thread. Other forms of the security element (100) which a person having skill in the art may contemplate are also well within the ambit of the present invention, and the present invention is not limited to the thread.

The security element (100) is having color changing effect in different view angle and having patterns in the shape/form of text or symbols which may include letters, numbers, pictures, digital image, digital photographs etc., or combinations of thereof , visible in the security element. The color change effect can be seen at different view angle when seen from the side of coating of the polymeric liquid crystal layer, the color change effect is visible only in the portion of the security element where the patterns are not configured in the security elements or in other words the portion area of security element where metal layer remains in the security element. The color change effect is not visible in the transparent area. No color change effect can be observed on the pattern area configured on the security element, which is de-metalized area and transparent, through the security area.

In accordance with the embodiments of the present invention, the security element (100) comprising a polymeric film (102) having a first operative surface (102a), and a second operative surface (102b) which is opposite to the first operative surface (102a). In accordance with one embodiment of the present invention the polymeric film (102) is transparent. In accordance with one embodiment of the present invention, the polymeric film (102) is made of polyethylene terephthalate. The security element (100) further includes a metal layer (104) disposed on the polymeric film (102). The metal layer (104) is defined between a first operative surface (104a), and a second operative surface (104b). The second operative surface (102b) of the polymeric film (102) is in direct contact with the first operative surface (104a) of the metal layer (104). Further, the metal layer (104) on the polymeric film (102) is so deposited that it is characterized by having de-metallised portions or areas or regions (104e, 104f, 104c2) at predefined positions, thereby defining transparent demetallised areas (104e, 104f, 104c2) in the shape or form of patterns. The patterns can be in the form or shape of text or symbols, the symbols can include letters, numbers, pictures, image, digital photographs, and combinations thereof, and adjacent metallised non-transparent areas (104c, 104c 1). However, it is to be noted that the shape or form of the patterns are not limited to the above- mentioned examples and any other shapes or forms are also well within the ambit of the present invention. In one embodiment the polymeric film can be taken as pre-deposited metal layer for further processing.

In accordance with one embodiment of the present invention, the metal layer (104) comprises a metal which is selected from the group consisting of aluminium, steel, copper (Cu) and combinations thereof. In accordance with one embodiment of the present invention, the metal layer (104) can have a thickness in the range of a minimum optical density of 2 or maximum optical density of 400 Angstrom units.

Further, a protective resist mask (106) is deposited on the metal layer (104). The protective resist mask (106) is defined by and between a first operative surface (106a), and a second operative surface (106b). The second operative surface (104b) being in contact with the first operative surface (106a). The protective resist mask (106) has patterns (106c) which are configured in various shapes or forms of text or symbols, wherein the symbols can include letters, numbers, pictures, image, digital photographs, and combinations thereof. In accordance with one embodiment of the present invention, the shape for forms of the protective resist mask (106) registers with the patterns of the text, and symbols of the metal layer (104), as described herein above.

In accordance with one embodiment of the present invention, the protective resist mask (106) is transparent. In accordance with another embodiment of the present invention, the protective resist mask (106) is coloured. In accordance with one embodiment of the present invention, the protective resist mask (106) is made by means of coloured resist material other than black.

The security element (100) further includes a photosensitive layer (108). The photosensitive layer (108) is disposed on the protective resist mask (106). The photosensitive layer (108) is defined by and between a first operative surface (108a), and a second operative surface (108b). The second operative surface (106b) of the protective resist mask (106) is in contact with the first operative surface (108a) of the photosensitive layer (108). In accordance with the present invention the patterns (108c) can be implemented in various shapes or forms of text or symbols. The symbols can be in form of letters, numbers, pictures, image, photographs, and combinations thereof. Further, in accordance with one embodiment of the present invention, the patterns (108c) register with the patterns (106c) of text, or symbols of the protective resist mask (106).

In accordance with one embodiment of the present invention, the photosensitive layer (108) is made of photosensitive black ink.

The security element (100) further includes a polymeric liquid crystal layer (110). The polymeric liquid crystal layer (110) is deposited on the photosensitive layer (108). In accordance the present invention, the polymeric liquid crystal layer (110) is defined by and between a first operative surface (110a), and a second operative surface (110b). The first operative surface (110a) is in contact with the second operative surface (108b). The polymeric liquid crystal layer (110) is disposed such that both the non-transparent areas (104cl) and transparent areas (104c2) are covered.

In accordance with the present invention, the colour change effect in the security element (100) is only visible or observed when the security element (100) is viewed at the different view angles from the polymeric liquid crystal layer side only, and further the colour changing effect is visible at different view angle in form of patterns which can be in the shape or form of text or symbols. The symbols can include letters, numbers, pictures, image, photographs, and combinations thereof.

In accordance with one embodiment of the present invention, different colour combinations can be achieved by changing the composition of the polymeric liquid crystal layer (110).

In accordance with one embodiment of the present invention, the security element (100) or product is in the form of a thread, piece of any predefined geometrical shapes, and with dimension as per user requirement. In accordance with one embodiment of the present invention, the security element (100) having predefined thickness as per the end use. In accordance with one embodiment of the present invention, the security element can be incorporated in a document, and product of value, the product of value being one of currency notes, passport papers, stamp paper, tax stamp papers, cheque, packaging, and labels.

In accordance with the present invention, the color change effect in the security element is observable at different view angles from the polymeric liquid crystal layer side only.

In accordance with one embodiment of the present invention, the color effect layer is generated by employing optical variable inks including such as the optical variable pigments.

In accordance with another aspect of the present invention, a method (200) of manufacturing the security element (100) or security product described herein above is disclosed. More specifically, the method (200) of manufacturing the security element (100) or the security product is described by referring to the FIG. 2, wherein FIG. 2 illustrates a flow chart of the method (200) for manufacturing the security element (100)/security product in accordance with the present invention.

The method (200) for manufacturing a security element (100)/security product with color change effect with patterns configured thereon comprises the following steps which are described herein below in detail.

In the first step, a polymeric film (102) is provided. The polymeric film (102) is having a first operative surface (102a) and a second operative surface (102b) opposite to the first operative surface (102a)(202). The polymeric film (102), in accordance with one embodiment of the present invention is transparent.

In accordance with one embodiment of the present invention, the polymeric film (102) is made of polyethylene terephthalate. In accordance with one embodiment, the polymeric film (102) is having a thickness in the range of 6 pm to 30 pm.

The polymeric film (102) may be cleaned using one or more cleaning solutions to render the polymeric film (102) or at least the second operative surface (102b) of the polymeric film (102) free of any dirt or foreign particles.

A metal layer (104) is deposited on full surface of the polymeric film (102)(204). The metal layer (104) can be deposited by any known method for deposition of the metals, which are known in the art. More specifically, the metal layer (104) is deposited such that the metal layer (104) is in contact with the second operative surface (102b) of the polymeric film (102). More specifically, a first operative surface (104a) of the metal layer (104) is in contact with the second operative surface (102b) of the polymeric film (102). Further, the metal layer (104) has a second operative surface (104b) opposite to the first operative surface (104a).

In accordance with one embodiment of the present invention, the metal layer (104) can be made of a metal selected from the group consisting of aluminium, steel, copper (Cu), and combinations thereof. Further, the metal layer (104) is having an optical density of not less than 2 or minimum 400 Angstrom unit.

Once the metal layer (104) is in place, a protective resist mask (106) is printed on selected areas of the second operative surface (104b) of the metal layer (104). More specifically, the protective resist mask (106) is deposited such that selected areas (106d) are covered by the protective resist mask (106) while other unselected areas remain uncovered which being referred to as uncovered areas (106e) hereinafter (206). In accordance with the present invention, the protective resist mask (106) is having a first operative surface (106a) in contact with the second operative surface (104b) of the metal layer (104) and a second operative surface (106b). The uncovered areas (106e) have patterns formed thereon, which are in the shape or form of text or symbols. The symbols can include letters, numbers, pictures, image, photographs etc., or combinations thereof. The protective resist mask (106) is preferably transparent. In accordance with one embodiment of the present invention, the protective transparent resist mask (106) is made by means of coloured resist material. In accordance with one embodiment of the present invention, the protective transparent resist mask (106) is made by means of coloured resist material other than black.

In the next step, the metal, which is not covered by the protective transparent resist mask (106) is removed (208). In accordance with the embodiments of the present invention, the step of removal of the metal from the uncovered areas (106e) from the metal layer (104) is achieved by etching process. In one embodiment, the removal of the metal is achieved by using a chemically acidic or basic solution to obtain an etched metal layer or demetallized layer (104e) defining demetallized areas (104f) on the metal layer (104). The demetallized areas are transparent (104f), and remaining areas which are not etched are opaque or non-transparent due to presence of metal on these areas.

Once the de-metallization is completed, a photosensitive layer (108) is deposited (210). More specifically, the photosensitive layer (108) is deposited on the full surface obtained after processing of protective resist mask (106) in the above step. The photosensitive layer (108) is having a first operative surface (108a), and a second operative surface (108b). The first operative surface (108a) of the photosensitive layer (108) is in contact with the second operative surface (106b) of the protective resist mask (106), and on demetallized transparent areas (104f), of the metal layer (104). In accordance with one embodiment of the present invention, the photosensitive layer (108) functions as a light absorbing layer.

In accordance with one embodiment of the present invention, the photosensitive layer (108) is made of photosensitive black ink.

The photosensitive layer (108) is then cured to obtain cured photosensitive layer (108)(212). The step of curing is carried out by using any known technique. In accordance with one embodiment of the present invention, the step of curing of the photosensitive layer (108) is achieved by employing hot air preferably at temperature in the range of 80 °C to 90 °C.

Further, the cured photosensitive layer (108) is irradiated with an ultraviolet light from the side of the first operative surface (102a) of the polymeric film (102) to obtain an irradiated photosensitive layer (108)(214). The ultraviolet light is incident onto the photosensitive layer (108) only through de-metallized areas (104f)(108d), which being transparent to the ultraviolet light, and the ultraviolet light cannot affect the areas of the cured photosensitive layer (108), wherein the metal layer which is not demetallized and hence is non-transparent.

In the next step, the areas of the irradiated photosensitive layer (108) exposed to the ultraviolet light are etched by using a chemically acidic or basic solution. More specifically, the uncovered areas (106e) are etched defining covered areas (108c) and uncovered areas (108d) ( 16) of the irradiated photosensitive layer (108) so as to achieve transparent areas in metal and photosensitive layers which are perfectly register with each other resulting in areas which are transparent from (102) up to (108) both inclusive.

Upon etching the irradiated photosensitive layer (108), a polymeric liquid crystal layer (110) is deposited or transfer coated thereover such that both the covered areas (108c) and the uncovered areas (108d) of the photosensitive layer (108) are covered by the polymeric liquid crystal layer (110) (218). This step of deposition or transfer coating of the polymeric liquid crystal layer (110) is followed by drying the same by hot air to obtain dried polymeric liquid crystal layer (110). The polymeric liquid crystal layer (110) is deposited by printing or transfer coating from a carrier.

Further, in accordance with the embodiments of the present invention, the photosensitive layer (108) is irradiated with ultraviolet light from the polymeric film side of the security element (100) to obtain an oriented polymeric liquid crystal layer (110) (220), thereby forming a film having a plurality of security elements (100). The security element (100) comprising patterns in the shape or form of text, or symbols. The symbols can include letters, numbers, pictures, digital images, photographs, etc., and combinations thereof, as a predefined security feature, or requested by the end user or customer.

The security element (100) which is in form of the film is slitted into a continuous thread of any width, or length or cut into geometrical shapes with different designs and sizes, or punched into shapes of different designs and sizes to obtain the security element product or article.

The so obtained security element (100) colour change effect can be observed when the security element is viewed at different viewing angles from the side of coating of the polymeric liquid crystal layer (110) and further that the colour change effect is visible only in the portion of the security element (100) where patterns are not configured in the security elements or in the portion of the security element where metal layer remains along with the photosensitive ink within the security element and the colour change effect is not visible in the transparent area.

In accordance with the embodiments of the present invention, the composition of the polymeric liquid crystal layer (110) can be changed to obtain different colour combinations in the security element. Application of the security element of the present invention:

The security element (100) of the present invention as disclosed and described herein above can be for example used in the form of a security thread in the documents of value like currency notes, passport paper, stamp paper or any other document which requires security features to identify the counterfeiting products.

Technical advance and advantages of the present invention

The present invention provides one or more technical advances and advantages of which a few are listed herein:

The security element disclosed herein is: o secure; o sturdy; o durable; and o Not easy to copy or counterfeit; and

The method for manufacturing the security element is: o Simple; o Faster production; o More precision in manufacturing; o More precision in pattern making; o More crisp and sharp Color change effect due to distinct process steps; and o Easy to work with.

Economic significance

The one of the objects of the Patent Law is to provide protection to new technologies in all fields and domain of technologies. The new technologies contribute in the country economy growth by way of involvement of new efficient and quality method or product manufacturing in India. To provide the protection of new technologies by patenting the product or process will contribute for innovation development in the country. Further, by granting patent the patentee can contribute in manufacturing the new product or use of new process of manufacturing by himself or by technology collaboration or through the licensing.

The applicant submits that the present disclosure will contribute in country economy, which is one of the purposes to enact the Patents Act, 1970. The product in accordance with present invention will be in great demand in country and worldwide due to novel technical features of the present invention. The present invention provides technical advancement in the field of security elements or security products. The technology will provide cheaper products, and save time of the total process of manufacturing the security element or product. The savings in the production time will improve the productivity, and cost cutting of the product, which will directly contribute to economy of the country.

The economic significance details requirement may be called during the examination.