DESC:FIELD OF THE INVENTION:
The present invention relates to method of manufacturing an assembly layered over a carrier film. More particularly, the present invention relates to method of manufacturing a colour shift assembly layered over a carrier film, wherein the colour shift assembly layered over the carrier film is so designed, provides improved peeling of the colour shift assembly. Further the colour shift assembly is manufactured such that, the additional step of applying a black coat or an opaque coat over the colour shift assembly is eliminated, whilst maintaining the characteristic of colour shift assembly.
BACK GROUND OF THE INVNETION:
Generally, while manufacturing a colour shift film, the method comprises of coating a liquid crystal layer over a PET or PET like substrate, since PET provides an uniform or even surface for coating the liquid crystal. The basic nature of coating a colour shift element for example liquid crystal polymer, is that it needs to be coated on an uniform surface, since liquid crystal will not be able to show its colour shift ability on an uneven surface. Therefore manufacturing a colour shift assembly, usually takes place by coating liquid crystal layer over a PET or PET like substrate i.e, PET is usually selected for casting a film over a PET or PET like substrate. The colour shift film once formed over the PET are generally peeled off or released by air knife technique, that involves uniform blowing of air to evenly remove the colour shift film. But the disadvantage of using the air knife technique is that sometime the peeling off or releasing the colour shift film off the PET may result in cracking or breaking of the colour shift film thereby results in wastage of colour shift film. Further peeling or releasing the colour shift film using the air knife technique is a time consuming process.
Further, method of manufacturing colour shift film involves coating the surface of the colour shift film, with a black coat or an opaque coat, in order for colour shift film to show there dual colour property when applied over a valuable document to be secured. Applying a black coat or an opaque coat layer is an additional step while manufacturing the colour shift film, that further adds up to the limitation while manufacturing the same with respect to cost and time required to manufacture.
In order to overcome the above mentioned limitations, it is necessary to provide an improved method of manufacturing a colour shift assembly over a carrier film, wherein the colour shift assembly -carrier film duo is so designed that it provide efficient peeling off or releasing off the colour shift film from the carrier film with zero breakage. Additionally, the limitation of wastage of colour shift film needs to be addressed.
Further it is necessary to provide a method of manufacturing colour shift assembly wherein the additional step of applying a black coat is eliminated and at the same time the colour shift assembly exhibits the dual colour property of the colour shift film when applied over a security document.
OBJECT OF THE INVENTION:
The primary object of the present invention is to provide an improved method of manufacturing a colour shift assembly over a carrier film, wherein the carrier is a water soluble film.
Another object of the present invention is to provide an improved method of manufacturing a colour shift assembly over a carrier film, wherein the additional step of adding a black coat over the colour shift assembly is eliminated.
Yet another object of the present invention is to provide a method of manufacturing a colour shift assembly over a carrier film, wherein the (carrier film) water soluble film provides improved peeling of the colour shift film when coated over the said water soluble film.
Yet another object of the present invention is to provide a method of manufacturing a colour shift assembly over a carrier film, wherein the dual colour characteristic of the colour shift assembly is maintained for security purpose.
Yet another object of the present invention is to provide a method of manufacturing a colour shift assembly, that eliminates wastage of colour shift film when coated over the said water soluble film.
Yet another object of the present invention is to provide a method of manufacturing a colour shift assembly over a carrier film, that maintains the stability of the liquid crystal layer coated over the water soluble film thereby enhancing the phenomena of colour shift liquid film.
BRIEF DESCRIPTION OF THE INVENTION:
Fig. 1: Illustrates method of manufacturing Roll A;
Fig. 2: Illustrates method of manufacturing Roll B, by a direct and an indirect method;
Fig. 3: Illustrates method of manufacturing Roll C and application of said Roll C, over the article printed with opaque text.
DETAILED DESCRIPTION OF THE INVENTION:
While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described, and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claim. As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned.
Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.
In this disclosure, whenever a composition or an element or a group of elements is preceded with the transitional phrase “comprising”, it is understood that we also contemplate the same composition, element or group of elements with transitional phrases “consisting of”, “consisting”, “selected from the group of consisting of, “including”, or “is” preceding the recitation of the composition, element or group of elements and vice versa.
The present invention relates to method of manufacturing a colour shift assembly layered over a carrier film, wherein the colour shift assembly layered over the carrier film is so designed, provides improved peeling of the colour shift assembly. Further the colour shift assembly is manufactured such that, the additional step of applying a black coat or an opaque coat over the colour shift assembly is eliminated, whilst maintaining the characteristic of colour shift assembly.
One embodiment of the present invention discloses a method of manufacturing a colour shift assembly over a carrier film comprising the steps of:
Step 1:
Method of manufacturing Roll A:
Method of manufacturing Roll A (100); wherein the method of manufacturing Roll A comprises the steps of:
-taking a (carrier film), wherein the carrier film is a polyethylene terephthalate (PET) or PET like substrate (101) of specific thickness; wherein the thickness of the substrate ranges from 5 to 25 micron;
- coating a layer of liquid crystal layer (102) over the PET or PET like substrate; wherein the thickness of the coated layer of liquid crystal layer ranges from 1 to 5 micron;
- curing the layer of liquid crystal layer coated over the PET or PET like substrate to form a liquid crystal film; the first assembly thus formed is referred to as Roll A.
Step 2:
Method of manufacturing Roll B :
Method of manufacturing Roll B (200) may take place by direct casting of Roll B on Roll A; wherein the method of manufacturing Roll B comprises the step of:
- casting a layer of water soluble material (103) over the liquid crystal film (102) of Roll A (100); wherein the thickness of the water soluble coat ranges from 5 to 10 micron; this assembly thus formed is referred to as Roll B.
Another method of manufacturing Roll B (200) may take place by laminating a preformed WSF on Roll A (100); wherein the method of manufacturing Roll B comprises the step of:
- taking a preformed water soluble film (WSF) (103) on a PET (104); wherein the thickness of the water soluble film (103) ranges from 5 to 10 micron; wherein the water-soluble film is selected from polyvinyl alcohol (PVA), hydroxypropyl methyl cellulose (HPMC), or a water-soluble polymer blend;
and
- laminating the preformed water soluble film (WSF) (103) over the liquid crystal film (102) of Roll A (100) and simultaneously releasing the carrier PET (104); the second assembly thus formed is referred to as Roll B (200).
Optionally, polyethylene-based layer may be selected from high-density polyethylene (HDPE) or low-density polyethylene (LDPE) as the supporting film carrier, instead of water soluble film, wherein the water soluble film, HDPE and LDPE acts as a supporting layer of the assembly formed as Roll B.
Step 3:
Method of manufacturing Roll C :
The method of manufacturing Roll C (300) comprises the steps of:
- Releasing the PET or PET like substrate (101) of Roll A (100), so as to expose the liquid crystal film (102); wherein after removing the PET or PET like substrate (101), a colour shift film (102) coated over the water soluble layer (103) is obtained, the third assembly formed now is referred to as Roll C (300).
The last step is required only when Roll C is to be used by the end user.
The said assembly of Roll C thus obtained may be used specifically over a paper or an article printed with any text, wherein the text is printed using black coat or an opaque coat. By this methodology the present invention provides an efficient method of manufacturing a colour shift assembly wherein the water soluble film acts as a carrier film, wherein the additional step of adding a black coat over the colour shift film is eliminated, wherein the paper or article wherever printed with text mimics the characteristic of black coat. Thus this methodology enables to retain the colour shift property of the liquid crystal film as well as at the same time the additional step of applying the black coat over the colour shift film is eliminated.
Further a person skilled in the art will appreciate, that a colour shift film will only show its colour shift characteristic once coated over a black surface, without the said black surface the colour shift film will not be able to show its colour shift property. Since this method of manufacturing a colour shift assembly over a carrier film does not involves the additional step of coating a black coat over the colour shift film, this method of manufacturing the colour shift film saves a lot of time and resources.
The exposed surface of the liquid crystal film of Roll C (300) is adhered to the printed text on the paper or an article, wherein the text is printed using black coat, such that the colour shift layer film is sandwiched between the printed paper or an article (at the obverse side) and water soluble film (at the face side), wherein the water soluble film forms the outer most surface (or top coat) when Roll C is adhered to a printed paper or an article
Another advantage provided by this unique method of manufacturing the colour shift assembly is designed to release /peel the colour shift film evenly or uniformly due to the presence of the water soluble film that dissolves in water in fraction of seconds, since water soluble film acts as a carrier. The peeling or releasing of the liquid crystal film from the PET or PET-like substrate is facilitated by dissolution of the water-soluble film in water, thereby providing uniform release of the colour shift film.
Further the water soluble film stands out to be of superior choice since it is more adherent /effective in exposing the colour shift film rather than using the PET for releasing/peeling the colour shift assembly.
The present invention over comes the limitation of the prior art, by providing an improved method of manufacturing a colour shift assembly over a carrier film, wherein the carrier so designed provide improved peeling/exposing the colour shift assembly. Additionally, the limitation of wastage of colour shift film is also addressed. Further the time required to manufacture the said product requires less time and energy and curbs wastage of non-uniform colour shift film.
The water-soluble carrier film provides improved adhesion and stability to the liquid crystal film during manufacturing the colour shift assembly over a carrier film, enhances the colour-shifting property of the coated liquid crystal layer. Further, due to this method of manufacturing a colour shift assembly over a WSF (water soluble film) eliminates the need for a black coat, thereby reducing time, cost, and energy required for manufacturing the colour shift assembly. The resulting colour shift assembly film retains dual-colour shifting property when viewed against a black printed background.
The present invention relates to method of manufacturing a colour shift film assembly over a carrier film, wherein the carrier so designed provide improved peeling off or releasing of the colour shift film as well as eliminates the additional step of applying a black coat over the colour shift film. Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be providing broadest scope consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and appended claims.

,CLAIMS:1. A method of manufacturing a colour shift assembly over a carrier film, the method comprising the steps of:
- taking a carrier film, wherein the carrier film is a polyethylene terephthalate (PET) or PET-like substrate (101);
- coating a liquid crystal layer (102) on said PET film, wherein the thickness of the liquid crystal layer ranges from 1 to 5 microns;
- curing the coated liquid crystal layer to obtain a liquid crystal film to form a first assembly (Roll A) (100);
- casting a layer of water-soluble film (103) over the cured liquid crystal film of Roll A to obtain a second assembly (Roll B) (200); or laminating a water-soluble film over the cured liquid crystal film of Roll A to obtain a second assembly (Roll B) (200);
- releasing the PET or PET-like substrate of Roll A so as to expose the liquid crystal film coated over the water-soluble film, thereby forming a third assembly (Roll C) (300);
wherein the water-soluble film acts as the carrier film for the colour shift assembly and enables peeling or releasing of the colour shift film without breakage or wastage, and wherein the method eliminates an additional step of coating a black or opaque layer over the colour shift assembly.
2. The method as claimed in claim 1, wherein the thickness of the water-soluble film (103) ranges from 5 to 10 microns.
3. The method as claimed in claim 1, wherein the water-soluble film (103) may be selected from polyvinyl alcohol (PVA), hydroxypropyl methyl cellulose (HPMC), or a water-soluble polymer blend.
4. The method as claimed in claim 1, wherein supporting film carrier made of a polyethylene-based layer may be selected from high-density polyethylene (HDPE) or low-density polyethylene (LDPE) as the supporting film carrier, instead of the water-soluble film.
5. The method as claimed in claim 1, wherein laminating the water-soluble film (103) comprises providing a pre-formed water-soluble film (103) coated over a PET substrate (104) and bonding it to the liquid crystal layer of Roll A.
6. The method as claimed in claim 1, wherein the colour shift assembly (300) obtained as Roll C is adhered to a paper or an article printed with opaque or black text, such that the text mimics the black coat, thereby enabling dual-colour shift characteristics of the liquid crystal film.
7. The method as claimed in claim 1, wherein peeling or releasing of the liquid crystal film (102) from the PET or PET-like substrate (101) is facilitated by dissolution of the water-soluble film in water, thereby providing uniform release of the colour shift film.
8. The method as claimed in claim 1, wherein the water-soluble carrier film (103) provides improved adhesion and stability to the liquid crystal film during manufacturing and enhances the colour-shifting property of the coated liquid crystal layer.
9. The method as claimed in claim 1, wherein the elimination of the black coat reduces the time, cost, and energy required for manufacturing the colour shift assembly.
10. The method as claimed in claim 1, wherein the resulting colour shift assembly film retains dual-colour shifting property when viewed against a black printed background.
11. A colour shift assembly over a carrier film consists of:
- a carrier film, wherein the carrier film is a polyethylene terephthalate (PET) or PET-like substrate (101);
- a liquid crystal layer (102) coated on said PET film, wherein the thickness of the liquid crystal layer ranges from 1 to 5 microns; wherein the liquid crystal film exhibits dual-colour shift characteristics when viewed against a black or opaque background, the first assembly obtained in Roll A (100);
- cast water-soluble film (103) layer or laminate a preformed layer of water-soluble film (103) over the cured liquid crystal film of Roll A to obtain a second assembly (Roll B) (200);
- release the PET or PET-like substrate of Roll A so as to expose the liquid crystal film coated over the water-soluble film, wherein the liquid crystal film having a thickness of 1 to 5 microns and wherein the water-soluble film layer of thickness 5 to 10 microns provided beneath the liquid crystal film;
wherein the liquid crystal film is free from PET substrate, and wherein the water-soluble film acts as the carrier film for the colour shift assembly and enables peeling or releasing of the colour shift film without breakage or wastage; and
wherein the assembly is adapted to be adhered to a paper or article printed with opaque or black text, such that the printed text mimics the black coat and enables dual-colour shift characteristics of the liquid crystal film.