FORM 2
THE PATENTS ACT 1970
(39of1970)
&
The Patent Rules, 2003
Complete Specification
(See section 10 and rule 13)
High Barrier Thermoforming Film And The Process To Make It
ACG Pharmapack Private Limited
Dalamal House. 10th Floor, Nariman Point, Mumbai 400 021. Maharashtra. India.
An Indian company registered under the Companies Act. 1956
The following specification particularly describes the invention and the manner in
which it is to be performed.

High Barrier Thermoforming Film And The Process To Make It
Field of invention:
The present invention is related to the films that are used for packaging purposed in food and pharmaceutical industry. More particularly, the invention relates to the films that are used in blister form medicinal tablet packaging.
Background of invention:
Metalized sheets or films for thermoformed trays consisting of a layer of thermoplastic sheet or film that has been metalized by a vacuum process to provide a metalized sheet or film are well-known. Metalized plastic articles may be prepared by applying a metal to a plastic material by vacuum deposition, electrolytic deposition, foil lamination or similar metalizing techniques. Such articles are widely employed for decorative purposes, particularly the metalized films which are quite flexible and can be shaped to some extent to conform to various contours.
The nature of these packagings requires them to be fairly ductile in nature so not only that the blisters can be formed with ease but that the barrier level remains at a high value throughout the shelf life. Techniques of forming multilayer films are known, however, achieving cost efficiency and also high barrier to moisture and gases remains to be an ongoing challenge for the pharmaceutical industry.

It is also possible that simply putting together two layers of metalized PVC (say. 250 microns) will provide enhanced water vapour barrier properties than a single layer. However, integrity of such a composite is difficult to achieve because it is not possible to achieve the sufficient interlayer bond strength between metal layers or even metal to PVC when you want to add one more polymeric layer through lamination process. Such a composite would also be quite heavy, relatively difficult to handle and very expensive.
If polypropylene (PP) alone were to be used for the purpose of making the film, it would need modifications to the currently used machinery for manufacturing thermoformed blisters, which although possible, is not a practical solution.
There is therefore a need to provide an inexpensive film for making thermoformed packaging articles suitable for food and pharmaceutical industries, which will provide high vapour barrier over the shelf life of the product.
Object of the invention:
Accordingly one object of the invention is to provide a film for making thermoformed packaging articles suitable for food and pharmaceutical industries, which will provide high vapour barrier over the shelf life of the product

Description of figures:
Figure 1-11 shows a cross sections of a typical structural composition of the invention and some of its embodiments Figure 12 shows the process of dry lamination
List of parts:
1- Base layer (PVC) 5- Metallisation layer 1 A-Coating layer (PVdC or 6- Colour laquor layer enhanced barrier PVdC) 7- Adhesive layer
2- MVB layer of PVdC 8- Colour pigment

3- EMVB layer of enhanced barrier PVdC
4- Lamination layer
Description of the invention:
The present invention provides a cost-efficient and effective film with an adequately high barrier to moisture, vapours and gases, for use in food and pharmaceutical industry. The film disclosed herein uses a base layer (1) which is provided with a coating (1 A) that is in the form of either a moisture vapour barrier layer (MVB) (2) or an enhanced moisture vapour barrier (EMVB) layer (3). A primer is provided between the base layer and either the MVB or EMVB layers.

The base layer (1) is typically made of PVC of food or pharmaceutical grade as per EC Directives and devoid of plasticizer. The thickness of the base layer ranges between 100 μm to 800 μm.
The MVB layer (2) is typically made of PVdC and the EMVB layer (3) is made of enhanced barrier grade of PVdC
The preferred embodiment of the invention comprises a base layer provided with a coating (1 A) which is in the form of the EMVB layer (3).
In a first aspect, the film of the invention has the EMVB layer which is further provided with a lamination (4). The lamination is typically provided in the form of polypropylene (PP) or special polypropylene which in turn may be either cast (CPP or SCPP) or blown (BPP or SBPP).
A second aspect provides an optional lamination (4) with metallization (5).
In yet another aspect of the invention, there is no coating (1A) provided on to the base layer (1) (that is MBV or EMVB is not provided) and the lamination (4) is provided directly on to the base layer (1).
In still further aspects of the invention, any of the earlier mentioned films may be provided with colour laquor (6).

One of the key advantages of the present invention over the currently available thermoformed films is now described. It is well known that enhanced barrier PVdC tends to be crystalline in nature. It is possible to thermoformed this material into small blisters, however, it's also well known that its brittleness in the sheet form increases with time. Therefore if a sheet film made from enhanced barrier PVdC is not used for blister forming soon after its manufacture, it adversely affects its machinability, which consequently leads to deterioration in its thermoforming properties. The existing films made from PVdC for the purpose of thermoforming blisters suffer from this limitation.
The present invention, on the other hand, discloses a film optionally incorporating enhanced barrier PVdC materials further optionally laminated with other ductile materials such as CPP, SCPP, BPP, or SBPP, and which is surprisingly found not only to improve its machinability (that is to say that its crystalline nature doesn't affect forming ability of the composite film) but also provides improved barrier property than that of the conventional films. The process of making this composite material is a challenging task, the details of which the present application discloses.
A dry lamination process or an inline lamination process is used to adhere various layers to each other. In the case of the dry lamination process an adhesive (7) is used as a glue between the base layer and any other layer.

As shown in Figure 1, which shows the product of the invention obtained by a dry lamination process, the base layer (1) is made from polyvinylchloride (PVC). There is no coating (1A). With the help of an adhesive (7), a lamination (4) is provided in the form of CPP, BPP, SCPP, or SBPP. These have been illustrated in examples 3,4, and 5.
As shown in figure 2, as a further embodiment, the base layer (1) of PVC is provided (with the help of an adhesive layer (7)) with a coating (1A) that is in the form of an MVB layer (2) made of PVdC, which in turn is provided with a lamination selected from a group comprising CPP, BPP, SCPP, or SBPP or any combination thereof. These have been illustrated in examples, 6, 7, 8, and 9.
As shown in Figure 3, the base layer (1) made of PVC is provided (with the help of an adhesive (7)) with a coating (1A) of an EMVB layer (3) made from enhanced barrier PVdC material, which in turn is provided with a lamination (4). The lamination (4) is further provided with a metallised layer (5) such that the metallised surface is on the outside face of the composite film. The lamination (4) is in the form of CPP, BPP, SCPP, or SBPP. These have been illustrated in examples 10, 11, 13, and 13.
As shown in Figure 4, the base layer (1) is provided, with the help of an adhesive (7), with a coating (1A) which is in the form of the MVB layer (2) (made from PVdC) which is in turn provided with a metallised layer (5). A lamination (4) is

also provided such that the metallised surface is between the PVdC coating and the lamination (4). The lamination is in the form of CPP, BPP, SCPP, or SBPP. These have been illustrated in example 14,
As shown in Figure 5, the base layer (1) is provided, with the help of an adhesive (7), with a lamination (4), which is further metallised such that the metallised surface is on the outside face of the composite film. The lamination is in the form of CPP, BPP, SCPP, or SBPP. These have been illustrated in examples 15, 16, 17, and 18.
In Figure 6 the structure of the film of the invention shown is similar to that shown in Figure 5 except that the metallised surface is adjacent to the adhesive layer. These have been illustrated in examples 19 and 20.
In Figure 7 a film without the coating (1A) but with metallization and additional colour laquor is shown. Here, the base layer (1) is provided with the lamination (4) with the help of an adhesive (7). This is indicated in examples 21 and 22.
Figures 8-11 show the products of the invention which have been obtained using an inline lamination process. One of the key advantages of the inline lamination process is that there's no need for an adhesive (7), thereby reducing costs. A further surprising advantage of the inline process is that the coating (1 A) is also not required. Thus, a PVC base layer (1) along with a lamination layer which is

optionally metallised, is surprisingly found to provide high resistance against moisture and vapours. The lamination (4) is provided in the form of CPP, BPP, SCPP, or SBPP. A colour pigment (8) is added to the base layer (1) where a product of specific colour is desired.
PVDC (standard or enhanced barrier grades) used in the present invention is typically between ] gsm to 120 gsm weight.
With regards the lamination, the lamination thickness is between 20 to 400 mm. As mentioned earlier the lamination may be SCPP or SBPP or metalized (with aluminium) CPP or BPP, or metalized (with aluminium) SCPP or SBPP, all combinations used in a thickness range of 20 μm to 400 μm.
The thickness of the composite film of the present invention is in a range of 121 μm microns to 1073 μm.
Based on various combinations of the base layer and the EMVB layer and whether a primer layer is used many embodiments of the inventions are possible:
1 .Base PVC / primer/ PVdC (1 to 120 gsm) / adhesive / metalized CPP or BPP,
2. Base PVC / primer/ PVdC (1 to 120 gsm) / adhesive / CPP or BPP metalized,
3. Base PVC / primer/ enhanced barrier PVdC (1 to 120 gsm) / adhesive / metalized CPP or BPP,

4. Base PVC / primer/ enhanced barrier PVdC (1 to 120 gsm) / adhesive / CPP or BPP metalized,
5. Base PVC/ CPP or BPP,
6. Base PVC / primer/ PVdC (1 to 120 gsm) / adhesive / CPP or BPP,
7. Base PVC/primer/ enhanced barrier PVdC (1 to 120 gsm)/ adhesive/ CPP or BPP
The products of all above embodiments are provided with a colour lacquer as appropriate as below;
1. Colour lacquering on top of the film,
2. Colour lacquering on metallisation,
3. Colour lacquering sandwich between top layer and base layer,
4. Coloured top layer /pigmented top layer,
5. Pigmented top layer & then metalized,
6. Lacquered top layer and then metalized,
7. Based layer lacquered and then laminated, (outside)
8. Based layer pigmented and then laminated.
The process of making the film of the first embodiment is disclosed. The process of making the film of the present invention comprises the steps of lamination, lacquering, and barrier layer coating. Lamination may be using a dry lamination process or an innovative inline lamination process.

Lamination
1. Dry lamination
The dry lamination process is well known to a person skilled in the art, however, it has been incorporated here for making this document self contained.
As shown in Figure 2, base PVC gets unwound from the unwinder and passes through the tray that contains water based adhesive which is applied to the web. The doctoring process ensures the uniform coating of the adhesive with the help of doctor blade on PVC. Gravure roller is designed in such way that it picks up the required amount of adhesive and deposited over the web. The viscosity of the adhesive is maintained and monitored through out the process by adjusting temperature suitably. The deposited adhesive then travels through a specially designed tunnel-type oven with specific temperature zones and to provide a traveling path of approximately 10-12 m. The temperature in the oven is maintained in the range of 70 to 95°C to dry out the adhesive when it comes out of the tunnel. The metalized BPP or CPP film comes in contact with this web and both the films travel through nip roller whereby the two layers are stuck together under the action of the pressure. The composite layer thus formed passes over the drum that is equipped with chilled water circulation to help cool down the laminate. The controlled cooling also eliminated the cross linking of adhesive ensuring a good bonding between two layers of the laminate.

2. Inline lamination
The lamination takes place insitu with calendared PVC film. The PVC film is produced by thinning of sludge under the action of three pressing rollers in a calendaring device, and then cooling the film at various temperatures with the help of take off rollers. A suitable colour pigment (8) is added to the base layer where a coloured product is desired. The custom made BPP or CPP metallised or non metallised film then unwinds through in-house made assembly and travels along with the hot PVC film. The two films are pressed together in hot condition to form a laminate. This process does not need any adhesives. The top layer film is formulated in such a way that it provides self-adhesion to hot PVC film in-situ, which ensures the high level of interlayer bond strength.
Interlayer Bond Strength:
Inter layer bond strength between polymeric substrate (the PVC) and metallised polymer layer for the currently available comparable packaging materials is found to be between 250 and 300 gm for a 15 mm wide strip at cross head speed of 100 mm/min.
This is considered as excellent strength and there's no literature to suggest that higher bond strengths have been reported for similar products. It has also been noted that in the existing products that use metallised lamination, metal gets transferred to the PVC substrate and deteriorates the quality of lamination, subsequently leading to de-lamination.

In the present invention, the SCPP/SBPP is made in such a way that it will have the polar group formation on surface that enhances the bond between metal and polymeric substrate. When this metallised SCPP/SBPP or CPP/BPP get laminated with PVC and expose for interlayer bond strength measurement we achieve a bond of 450 gm/ 15 mm at 100 mm/min cross head speed. And moreover the metal transfer from one layer to other is minimal results in higher shelf life of the product.
In summary, PVC laminate made using either of the two lamination processes is unique in that it enhances the inter layer bond strength between PVC and the BPP (or CPP) or any other similar material. It further allows the laminated film to be thermoformed in smooth way. The inter-layer bond, strength obtained by the inline lamination process is favourably comparable with any of the off line lamination processes available.
Lacquering (optional in case of dry lamination)
The dry lamination machine is used for lacquering the film. Wherein the substrate comes to on gravure roller through unwinder and then gravure roller pick up the lacquer from the tray and deposits it on substrate. The doctoring technique is applied prior to deposition in order to ensure uniform deposition. The lacquered substrate travels trough a controlled heating tunnel with a passage length of 10m where it's dried.

Barrier layer coating
Water based barrier polymer is used for coating the PVC base substrate. PVC film is unwound and subjected to a corona treatment. Next, it is coated with a primer in first station using gravure deposition technology that enhances the surface tension of substrate. Primered substrate travels through a heating zone where the temperature is maintained to dry it completely. Dried primer-coated substrate is then deposited with a barrier-emulsified polymer such as PVDC and/or enhanced barrier PVDC. The polymer deposition is carried out using the gravure technique with the help of either doctor blade or air knife to ensure accurate deposition of the barrier polymer.
The film then made goes for lamination with desired polymeric layer such as the pp, CPP, BPP, or metalized forms of these or any combination thereof.
The film made out of this process gives excellent barrier properties that last through the shelf life a typical pharmaceutical product. The film also lends itself well to thermoforming blisters without having to make any alterations to the existing fhermoform blister machines.
Barrier values for various combinations measured on Mocon (Permatran-3/33)

Experiments and results:
Several experiments were conducted to assess the vapour/gas resistance (measured as water vapour transmission resistance - WVTR measured in grams of vapour per sq meter per day) of the product of the invention. Several combinations of materials and their relative positioning, which have been listed earlier, were tested.
Examples 1 and 2 represent the experiments carried out on metallised products made using currently known processes.
Example 1
A 250 micron pharmaceutical grade PVC film roll devoid of plasticizer having 600 mm width was subjected to an unwinder of a gravure coating machine. Ester-acrylic based primer of viscosity of 26 to 32 sec. was applied using the gravure roller to the PVC film and extra primer was removed by doctoring process such that the primer thickness was 0.8 microns. The PVC film with the primer was sent through on-line ovens maintained at a temperature of 75° C using a conveyer belt at a speed of 30 m/min for drying the primer on the film. The drying of the primer on the film was confirmed by non tackiness and by non blocking of rewinding at the rewinder roller.

The two layer film thus formed was transferred to a vacuum deposition machine. This machine had an in situ plasma device and was fitted with an evaporation boat in which material to be deposited was placed. The primer coated surface of the laminated film was first treated with plasma and thereafter was deposited with aluminum metal having 99.99% purity. Thickness of this deposited layer was 0.001 microns. The thickness was achieved by adjusting the speed, height of the gun and magnitude of vacuum.
This three layer film was exposed to a differential embossing grating process. A custom built machine was used for the embossing process. The three layered film was placed on an unwinder of this custom made machine followed by passing it through the roller maintained at a temperature of 130 to 150° C in order to soften it. A diamond pattern shim was pressed on the metallised side of the film to create a diffraction grating embossed effect on the film. The shim made for the above purpose was cut with a diamond pattern by using computerized laser cutting mechanism to avoid duplication of the pattern by any one else.
Blisters packs were formed from this laminate by thermoforming process which showed excellent thermoforming performance and showed the fine diamond holographic pattern even after the thermoforming process.
Specification of the film was as follows:
Total thickness 250 micron
Adhesion of embossed pattern with scotch tape test: passes

Thermoforming performance Excellent
Impact strength 953 g
Tensile strength - Longitudinal 511 kg/cm2
-Transverse 488 Kg/cm2
Elongation - Longitudinal 5%
Transverse 4.8%
WVTR 2.8 g/m2/day
Example 2
Rigid PVC of 250 micron that complies 21 CFR and FDA norms suited to use in pharmaceutical and food application is passed through corona treator which enhances the surface polarity of substrate. Then this treated film passed through tray containing primer, excess primer applied on treated substrate then wiped off either through doctor blade or air blow to ensure uniform primer coating of 1 to 2 gsm as per requirement. This coated film passed through hot air oven where it experience temperature of 80 to 90 Deg. Centigrade, that ensures solvent evaporation. Now this substrate is having affinity towards PVdC, then the same substrate is passed through different station where PVdC is being applied on substrate through same gravure coating technique, curing/ solvent evaporation happens same as that of the primer coating, every station has got capability of applying 10 gsm uniform coat of PVdC, this way substrate is getting coated with 40, 60, 90 and 120 gsm of PVdC. Three samples were tested - 2/1,2/2, and 2/3:
2/1:
Construction 250 micron PVC / 40 gsm PVdC

GSM 380 gm/m2
Thickness 274 μ
Dimensional stability MD - (-3)
TD-(l)
Tensile Strength MD > 518 kg/cm2
WVTR
(38° C and 98 % Rh) 0.7 gm/m2/day
2/2:
Construction 250 micron PVC / 60 gsm PVdC
GSM 400 gm/m2
Thickness 286 u
Dimensional stability MD - (-3)
TD-(l)
Tensile Strength MD > 518 kg/cm2
WVTR
(38° C and 98 % Rh) 0.65 gm/m2/day
2/3:
Construction 250 micron PVC / 90 gsm PVdC
GSM 430 gm/m2
Thickness 305 μ
Dimensional stability MD - (-3)
TD-(l)
Tensile Strength MD > 518 kg/cm2
WVTR
(38° C and 98 % Rh) 0.4 gm/mVday

Construction 250 micron PVC / 120 gsm PVdC
GSM 460 gm/m2
Thickness 323 ^L
Dimensional stability MD - (-3)
TD-(l)
Tensile Strength MD > 518 kg/cm2
WVTR
(38° C and 98 % Rh) 0.3 gm/m2/day
Examples of tests carried out on the product of the invention
Rigid PVC of desired thickness (between 200 and 250 micron was been used in the examples that follow) that complies 21 CFR and FDA norms suited to use in pharmaceutical and food application was passed through corona treator. This treatment was provided to enhance polar group formation over the surface of the film which in turn results in better wet ability. This film was next passed through a tray containing water-based adhesive comprising acrylates, polyurethane, and inomers cross linked with Isocyanate catalyst with heat or without cross linkers. This treatment was provided to enhance the interlayer bond strength between various layers of the film. An engrave gravure cylinder was next dipped into a tray containing the adhesive. The cylinder was rotated to pick up adhesive from the tray after which excess adhesive was wiped out with the help of a doctor blade to ensure uniform adhesive coating. The adhesive was then transferred over the substrate with the help of a rubber roller such that the substrate along with the

adhesive achieves required weightage (gsm). Next, the substrate with the adhesive applied to it was passed through an oven maintained at a temperature between 85 to 95 degree centigrade providing a travel path of 12 m, in order to evaporate water from the adhesive. Cast PP or Blown PP having thickness of a desired thickness was next unwound from the unwinder and brought in contact with base PVC substrate as it came out from the oven. Both films were nipped together, and were passed over a chilled roller for adhesion to take place. To get the proper jellification of the adhesive one hot roller is provided over substrate at the time of nipping and the temperature of this steel roller is maintained in the range of 80 to 95 degree Centigrade.
Laminate made out of this process is then subject to various testing after proper curing period. Test results for this laminate is as mentioned below. The following examples use various thicknesses of the PVC substrate and that of the Cast PP/Blown PP material.
In some of the examples, the rigid PVC is coated with a PVdC layer of desired thickness (40-80 gsm) before providing the corona treatment.
In some other examples, the Cast PP or Blown PP film is metallised with 99.99% pure aluminum in vacuum metallization technique before applying to the substrate such that the metallised side of the CPP/BPP is outside.

In still some other examples, the Cast PP or Blown PP film is metallised with 99.99% pure aluminum in vacuum metallization technique before applying to the substrate such that the metallised side of the CPP or BPP is inside, that is it is in contact with the substrate.
In yet further examples 60 micron BPP metallised with 99.99% aluminum vapourisation as per prior art example subject to rotogravure printing and water base as well as solvent based roto gravure inks were used and these inks in various shades applied on metallised surface of this film.
Finally some examples reflect the lamination of various layers carried out as off line lamination (the dry process) and some others (as mentioned specifically) use inline lamination.
The process used for examples 3 to 27 is the same as that described above, that is using the dry lamination technology. However, there are some variations from example to example. Major variations include:
- the example 3 uses a PVC substrate which has been laminated with
Special cast PP in accordance with the process described above
in examples 6-9 a coating of PVdC has been applied between the PVC and blown PP layer
- in examples 10-13, enhanced barrier PVdC was used instead of PVdC

in examples 14-20 the vapour barrier layer has been metallised with metal side in or metal side out and using either blown PP or cast PP depending on the example - examples 21 -22 consider metallised and laquered films examples 23-27 used a inline lamination process
(Further to the above categorization, the product used in examples 3 to 23 is produced by a dry lamination process.)
Example 3 (see Fig 1)
Rigid PVC: 250 micron with corona treatment SCPP : 75 micron
GSM 417gm/m2
Thickness 328 (a.
Dimensional stability MD - (-2); TD - (1)
Tensile Strength MD - 567 kg/cm2; TD - 515 kg/cm2
% Elongation MD - 203; TD - 195
WVTR 2.33 gm/m2.day
Example 4 (see Fig 1)
Rigid PVC: 250 micron with corona treatment SBPP: 90 micron
GSM 426 gm/m2
Thickness 343 μ
Dimensional stability MD - (-1); TD - (0)
22

Tensile Strength MD - 531 kg/cm2; TD - 545 kg/cm2
% Elongation MD - 120; TD - 111
WVTR 1.54gm/m2.day
Example 5 (see Fig 1)
Rigid PVC: 200 micron with corona treatment
SCPP : 60 micron
GSM 326 gm/m2
Thickness 263 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 531 kg/cm2; TD - 545 kg/cm2
% Elongation MD - 120; TD - 111
WVTR 1.54gm/m2.day
Example 6 (see Fig 2)
Rigid PVC of 200 micron with corona treatment Coating of 40 gsm of PVdC; Blown PP: 60 micron
GSM 379 gm/m2
Thickness 28714.
Dimensional stability MD - (-3); TD - (1)
Tensile Strength MD - 518 kg/cm2; TD - 496 kg/cm2
% Elongation MD - 81; TD - 75
WVTR 0.67 gm/m2.day
OTR 0.98 cc/m2.day
Example 7 (see Fig 2)
Rigid PVC: 200 micron with corona treatment Coating of 60 gsm of PVdC Cast PP : 60 micron

GSM 384 gm/m2
Thickness 299 μ
Dimensional stability MD - (-3); TD - (1)
Tensile Strength MD - 482 kg/cm2; TD - 471 kg/cm2
% Elongation MD - 84; TD - 71
WVTR 0.49 gm/m2.day
OTR 0.74 cc/m2.day
Example 8 (see Fig 2)
Rigid PVC: 200 micron with corona treatment Coating: 90 gsm of PVdC Blown PP: 60 micron
GSM 421 gm/m2
Thickness 318 μ
Dimensional stability MD - (-4); TD - (1)
Tensile Strength MD - 496 kg/cm2; TD - 471 kg/cm2
% Elongation MD - 70; TD - 75
WVTR 0.38 gm/m2.day
OTR 0.48 cc/m2.day
Example 9 (see Fig 2)
Rigid PVC: 200 micron with corona treatment
Coating: 120 gsm of PVdC
SBlownPP: 60 micron
GSM 454 gm/m2
Thickness 336 μ
Dimensional stability MD - (-3); TD - (1)

Tensile Strength MD - 493 kg/cm2; TD - 478 kg/cm2
% Elongation MD - 69; TD - 57
WVTR 0.26 gm/m2.day
OTR 0.18cc/m2.day
Example 10 (see Fig 3)
Rigid PVC: 200 micron with corona treatment
Coating: 40 gsm of enhanced barrier PVdC.
SCPP : 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique with the metal side out
GSM 373 gm/m2
Thickness 300 u
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.416 gm/m2.day
Example 11 (see Fig 3)
Rigid PVC: 200 micron with corona treatment
Coating with 60 gsm of enhanced barrier PVdC
SBPP: 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique with the metal side out
GSM 379 gm/m2
Thickness 300 μ
Dimensional stability MD - (-2); TD - (0)
Tensile Strength MD - 506 kg/cm2
TD- 471 kg/cm2
% Elongation MD - 78

TD- 71
WVTR 0.319 gm/m2.day
Example 12 (see Fig 3)
Rigid PVC: 200 micron with corona treatment
Coating: 90 gsm of enhanced barrier PVdC
Cast PP : 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique with the metal side out
GSM 418gm/m2
Thickness 318 u
Dimensional stability MD - (-1); TD - (1)
Tensile Strength MD - 510 kg/cm2; TD - 451 kg/cm2
% Elongation MD - 51; TD - 48
WVTR 0.291 gm/m2.day
Example 13 (see Fig 3)
Rigid PVC: 200 micron with corona treatment
Coating: 120 gsm of enhanced barrier PVdC
Cast PP : 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique with the metal side out
GSM 448 gm/m2
Thickness 335 μ.
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 500 kg/cm2; TD - 472 kg/cm2
% Elongation MD - 45; TD - 38
WVTR 0.17gm/m2.day

Example 14 (see Fig 4)
Rigid PVC: 250 micron with corona treatment
Coating: 40 gsm of PVdC
Blown PP: 50 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique, with the metal side in contact with the substrate
GSM 425 gm/m2
Thickness 322 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.24 gm/m2.day
Example 15 (see Fig 5)
Rigid PVC: 200 micron with corona treatment
Cast PP : 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique with the metal side in contact with the substrate
GSM 317 gm/m2
Thickness 250 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.58 gm/m2.day
Example 16 (see Fig 5)
Rigid PVC: 200 micron with corona treatment
Blown PP: 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique, with the metal side out

GSM 317gm/m2
Thickness 300 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.62 gm/m2.day
Example 17 (see Fig 5)
Rigid PVC: 200 with corona treatment
Cast PP : 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique, with the metal side out
GSM 317gm/m2
Thickness 300 μ.
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.62 gm/m2.day
Example 18 (see Fig 5)
Rigid PVC: 200 micron with corona treatment
Blown PP: 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique, with the metal side out
GSM 317gm/m2
Thickness 300 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.62 gm/m2.day

Example 19 (see Fig 6)
Rigid PVC: 200 micron with corona treatment
Cast PP: 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique, with the metal side in contact with the substrate
GSM 317gm/m2
Thickness 250 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.58 gm/m2.day
Example 20 (see Fig 6)
Rigid PVC: 200 micron with corona treatment
Blown PP: 60 micron having metallised with 99.99% pure aluminum in vacuum
metallization technique, with the metal face in contact with the substrate
GSM 317gm/m2
Thickness 250 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.58 gm/m2.day
Example 21 (see Fig 7)
Rigid PVC - 200 micron with corona treatment
Blown PP - 60 micron metallised with 99.99% pure aluminum in vacuum
metallization technique and coloured with coloured surface in contact with base
PVC

GSM 327 gm/m2
Thickness 260 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.58 gm/m2.day
Example 22 (see Fig 7)
Rigid PVC - 200 micron with corona treatment
Cast PP - 50 micron having metallised with 99.99% pure aluminum in vacuum metallization technique and printed with various colours and in contact with base PVC substrate
GSM 317 gm/m2
Thickness 250 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 532 kg/cm2; TD - 507 kg/cm2
% Elongation MD - 64; TD - 49
WVTR 0.62 gm/m2.day
The following examples indicate results on product samples made using inline lamination.
Rigid PVC 200 micron thickness that complies 21 CFR and FDA norms suited to use in pharmaceutical and food application film is used in this application. 60 micron BPP film produced in such a way that during processing it is being blended with low molecular weight polymer that is compatible with

thermoformable polypropylene and can exhibit sticking properties when lower temperature applied while lamination. The same film was optionally metallised with 99.99% pure aluminum and ensured that metallised portion is coming in contact with PVC while inline lamination. This film is unwinded from unwinder and introduced it at one of the takeoff rollers of calendar where temperature is more than 100° C and then nipped it with rubber roller at the pressure of 6 kg/cm2 then allow it to cool down along with PVC film. This process which is nomenclature as in-line lamination gives strong inter layer bond between PVC and BPP, this bond is comparable with any of the offline lamination process.
Example 23 (Inline lamination - see Figure 8)
Rigid PVC : 200 micron
BPP - 60 micron (without metallization)
Inline lamination at more than 100° C and at a pressure of 6 kg/cm2
Test results of this specification is as mentioned below,
Construction 200 micron PVC / 60 micron BPP
GSM 326 gm/m2
Thickness 263 μ
Dimensional stability MD ~ (-1); TD - (0)
Tensile Strength MD - 531 kg/cm2; TD - 545 kg/cm2
% Elongation MD - 120; TD - 111
WVTR 1.54gm/m2.day
Example 24 (Inline lamination - see Figure 9)
Rigid PVC : 200 micron
BPP - 60 micron (metallized and metalized face in contact with PVC)

Inline lamination at more than 100° C and at a pressure of 6 kg/cm2
GSM 326 gm/m2
Thickness 263 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 531 kg/cm2; TD - 545 kg/cm2
% Elongation MD - 120; TD - 111
WVTR 1.54gm/m2.day
Example 25 (Inline lamination - see Figure 10)
Rigid PVC : 200 micron
BPP - 60 micron (metallized and metalized face on the outside)
Inline lamination at more than 100° C and at a pressure of 6 kg/cm2
GSM 326 gm/m2
Thickness 263 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 531 kg/cm2; TD - 545 kg/cm2
% Elongation MD - 120; TD - 111
WVTR 1.54gm/m2.day
Example 26 (Inline lamination - see Figure 11)
Rigid PVC : 200 micron with pink pigment
BPP - 60 micron (metallized and metalized face on the outside) Inline lamination at more than 100° C and at a pressure of 6 kg/cm2
GSM 326 gm/m2
Thickness 263 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 531 kg/cm2; TD - 545 kg/cm2
% Elongation MD - 120; TD - 111
WVTR 1.54gm/m2.day

Example 27 (Inline lamination - see Figure 11)
Rigid PVC : 200 micron with green laquor
BPP - 60 micron (metallized and metalized face on the outside)
Inline lamination at more than 100° C and at a pressure of 6 kg/cm2
GSM 326 gm/m2
Thickness 263 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 531 kg/cm2; TD - 545 kg/cm2
% Elongation MD - 120; TD - 111
WVTR 1.54gm/m2.day
Example 28 (Inline lamination - see Figure 11)
Rigid PVC : 200 micron with blue pigment
BPP - 60 micron (metallized and metalized face on the outside)
Inline lamination at more than 100° C and at a pressure of 6 kg/cm2
GSM 326 gm/m2
Thickness 263 μ
Dimensional stability MD - (-1); TD - (0)
Tensile Strength MD - 531 kg/cm2; TD - 545 kg/cm2
% Elongation MD - 120; TD - 111
WVTR 1.54gm/m2.day
Various materials being used in Pharma industry to pack medicine as single dose in blister form, Cold Form Blister is the ultimate one that contains 15 micron Nylon/ aluminum foil 45 to 60 micron / 60 micron PVC this is also known as Alu-Alu structure and barrier of this material is almost "0" for gases as well as for

water vapour. But being aluminum as one of the largest component in it, has limitation on forming cavity results in employing cold forming technique that hampers productivity, increase the area required hence need more material, bigger shape of blister results in additional expenses on secondary packing, increase in secondary packaging is also because of aluminum which is flimsy and not friendly for logistic. Over and above this it is opaque so one cannot see through the product packed inside, requires lot of energy not only to form as blister but also while getting aluminum from earth. Cost of this material is Rs. 800 to 850 /kg.
There is one more polymeric material known as Aclar used for blister application having WVTR from 0.26 to 0.08 gm/m2/day (38°C and 98 % Rh) available in 23, 51,76 and 102 micron need to laminate with rigid PVC for blister application and costing between Rs.1000 to 2000 /kg as barrier increases the cost also increases.


No. Rigid PVC PVdC
Coating
(thk) Cast PP or Blown PP Weight of
finished product Thickne ss of finished product Dimensional stability in % Tensile Strength % Elongation WVTR OTR
(μ) (gsm) (M) (gsm) (μ) MD TD MD (kg/cm2) TD (kg/cm2) MD TD (gm/m2.d ay) (cc/m2. day)
Dry lamination
3 250 None 75 417 328 (-2) 1 567 515 203 195 2.33
4 250 None 90 426 343 (-1) 0 531 545 120 111 1.54
5 200 None 60 326 263 (-1) 0 531 545 120 111 1.54
6 200 40 60 379 287 (-3) 1 518 496 81 75 0.67 0.98
7 200 60 60 384 299 (-3) 1 482 471 84 71 0.49 0.74
8 200 90 60 421 318 (-4) 1 496 471 70 75 0.38 0.48
9 200 120 60 454 336 (-3) 1 493 478 69 57 0.26 0.18
10 200 40 60* 373 300 (-1) 0 532 507 64 49 0.416
11 200 60 60* 379 300 (-2) 0 506 471 78 71 0.319
12 200 90 60* 418 318 (-1) 1 510 451 51 48 0.291
13 200 120 60* 448 335 (-1) 0 500 472 45 38 0.17
14 250 40 50** 425 322 (-1) 0 532 507 64 49 0.24
15 200 None 60** 317 250 (-1) 0 532 507 64 49 0.58
16 200 None 60* 317 300 (-1) 0 532 507 64 49 0.62
17 200 None 60* 317 300 (-1) 0 532 507 64 49 0.62
18 200 None 60* 317 300 (-1) 0 532 507 64 49 0.62
19 200 None 60** 317 250 (-1) 0 532 507 64 49 0.58

20 200 None 60** 317 250 (-1) 0 532 507 64 49 0.58
21 200 None 60+ 327 260 (-1) 0 532 507 64 49 0.58
22 200 None 50+ 317 250 (-1) 0 532 507 64 49 0.62
Inline lamination (at more than 100°C and at a pressu re of 6 kg/cm2)
23 200 None 60 326 263 (-1) 0 531 545 120 111 1.54
24 200 None 60++ 326 263 (-1) 0 531 545 120 111 1.54
25 200 None 60++ 326 263 (-1) 0 531 545 120 111 1.54
26 200* None 60++ 326 263 (-1) 0 531 545 120 111 1.54
27 200*2 None 60++ 326 263 (-1) 0 531 545 120 111 1.54
27 200*3 None 60++ 326 263 (-1) 0 531 545 120 111 1.54
having metallised with 99.99% pure aluminum in vacuum metallization technique with the metal side out
having metallised with 99.99% pure aluminum in vacuum metallization technique, with the metal side in contact with the
** substrate
printed metallised CPP or BPP hence metal inside
+ metallised coloured (out side)
+* Metallised and metallised face in contact with PVC
* with pink laquor #3 with green laquor
#z With blue pigments

The following table provides a summary of the results presented earlier in terms of the most important parameters - the WVTR

Sr.
No. Composite WVTR (gm/m2/day)
I PVC 250 μm (prior art) 3 to 3.5
2 Metalized PVC 250 μm (prior art) 1.8 to 2.5
3 PVC 250 urn/ PVdC 40 g/m2 (prior art) 0.65 to .70
4 PVC 250 μm/ PVdC 90 g/m2 (prior art) 0.31 to 0.36
5 PVC 200 μm/ 50 micron CPP or BPP metalized (metal out side) (more economical, environmentally friendly) 0.59 to 0.62
6 PVC 200 μm/ 50 micron CPP or BPP metalized (metal inside) 0.22 to 0.26
7 PVC 250 μm/ enhanced barrier PVdC 40 g/m2/ 50 CPP or BPP metalized (metal inside) 0.14 to 0.15
8 Metalized CPP or BPP 50 urn 0.45 to 0.60
9 200 micron PVC/60 micron CPP or BPP 1.4 to 1.5
It has been found that the invention offers several benefits over the conventional comparable products. Some of these are:
1. Enhanced barrier properties for PVC alone without coating of PVdC that improves the barrier properties of the base film.
2. The product of the present invention (serial no. 5) provides barrier properties of that of the 40 gsm coated PVdC over PVC (serial no. 3). It is also seen that placing the metalized surface inside (serial no. 6), the barrier value improves further and. This is a major advantage as the product of the instant invention is substantially lighter in weight than existing products

thus the comparable savings (commercial and environmental) to be had by using the invention are substantial.
3. It is evident that metalized PVC has limited scope in enhancing barrier properties which is in a tune of 1.8 to 2.5 over plain PVC having barrier of 3 to 3.5 gm/m2/day,
4. As the PVC supports PP to form without carrying out any modification in existing thermoform blister machine, the invention can me manufactured using existing machinery without modification.
5. Various colour combinations make this product to stand out in crowd and act as overt anticouterfeit solution that can be made out by the layman.
It is evident from the forgoing discussion that the present invention comprises the following items and embodiments
1. A high barrier thermoforming film comprising a substrate made of polyvinyl chloride characterized in that said substrate is further applied with at least one element from a group comprising a coating of moisture and vapour barrier material, and a lamination material.
2. A high barrier thermoforming film as described in embodiment I characterized in that said coating is in the form of materials such as polyvinylidene chloride (PVdC) or enhanced polyvinylidene chloride, and said lamination is made of a material selected from a group comprising

polypropylene, cast polypropylene, blown polypropylene, special cast polypropylene, or special blown polypropylene.
3. A high barrier thermoforming film as described in embodiments 1 to 2, wherein said film is further provided with a metallised layer, the metallised face being either in proximity with the substrate or on the outside face of said film.
4. A high barrier thermoforming film as described in embodiments 3 wherein the metallization layer is achieved with fine metal powder.
5. A high barrier thermoforming film as described in embodiments 3 and 4 wherein the metal used for metallization of said film is aluminium.
6. A high barrier thermoforming film as described in embodiments 1 to 5 wherein the thickness of said substrata is in the range between 100 μm to 1000 μm.
7. A high barrier thermoforming film as described in embodiments 3 to 6 wherein the metallised layer is of the thickness between up to 125 urn.
8. A process of making a high barrier thermoforming film of claims 1 to 7 comprising the steps of providing a corona treated substrate and applying at least one of the following layers: i) a coating of moisture and vapour barrier material ii) a lamination layer, to said substrate, wherein either of the two layers may be optionally metallised, wherein in the case where said coating is applied it is applied using a dry lamination process and wherein when only a combination of a substrata and the lamination layer is used, a wet lamination process is used.

9. A process of making a high barrier thermoforming film as claimed in claim 8 wherein the metallised surface is either in proximity of the substrate or on the outside face of the composite film.
10. A process of making a high barrier thermoforming film as claimed in claims 8 and 9 wherein the material used for lamination is selected from a group of materials comprising polypropylene, cast polypropylene, blown polypropylene, special cast polypropylene, or special blown polypropylene.
While the above description contains much specificity, these should not be construed as limitation in the scope of the invention, but rather as an exemplification of the preferred embodiments thereof. It must be realized that modifications and variations are possible based on the disclosure given above without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.

We claim:
1. A high barrier thermoforming film comprising a substrate made of polyvinyl chloride characterized in that said substrate is further applied with at least one element from a group comprising a coating and a lamination material, said coating made of moisture and vapour barrier material.
2. A high barrier thermoforming film as claimed in claim 1 characterized in that said coating is in the form of materials such as polyvinylidene chloride (PVdC) or enhanced polyvinylidene chloride or a combination thereof, and said lamination is made of a material selected from a group comprising polypropylene, cast polypropylene, blown polypropylene, special cast polypropylene, or special blown polypropylene.
3. A high barrier thermoforming film as claimed in claims 1 to 2, wherein said film is further provided with a metallised layer, the metallised face being either in proximity with the substrate or on the outside face of said film.
4. A high barrier thermoforming film as claimed in claim 3 wherein the metallization layer is achieved with fine metal powder.
5. A high barrier thermoforming film as claimed in claims 3 and 4 wherein the metal used for metallization of said film is aluminium.
6. A high barrier thermoforming film as claimed in claims 1 to 4 wherein the thickness of said substrata is in the range between 100 μm to 1000 μm.
7. A high barrier thermoforming film as claimed in claims 3 to 6 wherein the metallised layer is of the thickness between up to 125 μm.

8. A process of making a high barrier thermoforming film of claims 1 to 7 comprising the steps of providing a corona treated substrate and applying at least one of the following layers: i) a coating of moisture and vapour barrier material ii) a lamination layer, to said substrate, wherein either of the two layers may be optionally metallised, wherein in the case where said coating is applied it is applied using a dry lamination process and wherein when only a combination of a substrata and the lamination layer is used, a wet lamination process is used.
9. A process of making a high barrier thermoforming film as claimed in claim 8 wherein the metallised surface is either in proximity of the substrate or on the outside face of the composite film.
10. A process of making a high barrier thermoforming film as claimed in claims 8 and 9 wherein the material used for lamination is selected from a group of materials comprising polypropylene, cast polypropylene, blown polypropylene, special cast polypropylene, or special blown polypropylene.