FORM 2
THE PATENTS ACT, 1970
PROVISIONAL SPECIFICATION
(SECTION 10)
TITLE : A BIO COMPOSTABLE FLEXIBLE PACKAGING MATERIAL WITH HIGH BARRIER PROPERTIES.
APPLICANT: MANUGRAPH INDIA LTD.,
Sidhwa House, 1st Floor, N.A.SawantMarg, Colaba, Mumbai - 400 005. Maharashtra,India, Indian National, an Indian Company incorporated under The Companies Act, 1956.

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

Field of the invention:
The Invention relates to a Bio-compostable Flexible packaging material having excellent water vapor barrier properties and oxygen barrier properties and method for making the same.
Plastics have been an important part of our lives today and flexible packaging is the most commonly used material for packaging. However there is an increasing environment and waste management concern on the disposal of post consumer waste generating by these synthetic packaging materials and other plastics. With the promotion of Composting and availability of commercial composting facilities all over the world and effective segregation of waste at source , compostable and biodegradable polymers derived from renewable raw material sources are now looked up to as a substitute to the synthetic packaging materials that are non compostable and have a very high end of life. The preference of using a Synthetic Polymeric packaging material over the earlier packaging materials like cardboard, Glass, tin, wood was that the polymers are designed to have a very good resistance to moisture and gas. Hence these polymers would facilitate the retention of freshness and aromas of the enclosures thereby giving a very good shelf life (i.e. retention of same state of the product when packed). These materials have been used for the properties exhibited like good seal ability, good barrier from Oxygen, and moisture, printability, gloss, aesthetics, transparency etc. In generalthese packaging materials - the mainstream of the packaging industry have become a huge industry and have replaced most of the traditional packaging materials like cardboard, tin and glass over the years. However these materials are acting as disposable flexible containers after single useand need to be disposed properly. The plastic laminates post use are supposed to be subjected to incineration treatment (which is actually done on a very small

percentage of the total produce) and most of these materials are however dumped into a land fill. Here these materials would remain for several hundreds of years. Again these traditional laminates cannot be recycled due to a mixed composition. Also when the plastic laminates are scattered as wastes in natural environments, they would remain in the same state for several hundreds of years without being degraded, thereby causing environmental pollution.
In recent years, plastics which are dumped in large quantities have been noted as a pollutive source in the natural environments. In order to solve this problem, biodegradable and compostable plastics have been marked as plastics which are "gentle to environment". These compostable plastics are reduced to C02, H20 and Biomass when degraded in a compost environment. In addition to Flexible packaging materials, other coated paper products such as Tetra packs, gable-top cartons, folding cartons, paper pouches, sandwich wraps, and ream wrap may also benefit from including an environmentally friendly biodegradable material. As these materials are one time use and are non recyclable due to the coating of synthetic polymeric materials for water barrier, these materials form a large portion of landfills and eventually cause pollution. These materials could be coated with biopolymers instead of synthetic polymers as the biopolymer materials are compostable and can also be re-pulped with paper. In metropolitan cities, where landfill space is very limited, compostable renewable-resource-based materials should preferred. In additional, municipal composting is a growing trend all over the world, especially where landfills are filling too quickly and related costs are rising rapidly.
The currently available biodegradable materials are poor in terms of barrier properties from moisture and gases thereby making them in-compatible with synthetic packaging materials. The present invention relates to a new

packaging material which completely eliminates the aforesaid drawbacks and provides the product packed with a minimum shelf life of 60 days to a maximum of 180 days and can be used in various industries like Packaging of dry and semi dry edible/non edible items, cement, envelopes, other packaging materials etc.
The paper based bio-compostable flexible packaging material made of such plastics in the end will undergo bio-degradation under the influence of bacteria. The bio-plastic laminate will degrade to CO 2 and H 2 O, and Biomass is generated and the paper that is made of wood pulp which is a type of cellulose will decompose in a similar time frame as that required for bio-plastics.
Description of the related prior art
Synthetic packaging materials have been made by combining the properties of 2 different polymers to create a barrier packaging material. This packaging material uses the combination of barrier properties of PET (poly ethylene terepthalate) in combination with the excellent heat sealing properties of PE (poly ethylene). The most conventional packaging material is PET-PE or PET -METPET- PE. Please refer to figure 1. Here the transparent PET layer is reverse printed and then further adhesive laminated to a multi layered PE layer. The lamination adhesive used is PU (poly urethane) based and the printing process is mostly Rotogravure.
A high barrier structure is created by using PET-METPET-PE wherein the transparent PET layer is reverse printed and further adhesive laminated to a Metallized PET (MET-PET). This structure is further adhesive laminated to a multilayer PE. Please refer to fig. in Prior art 2.

Since both the polymers belong to a different family of polymers and different chemical functional groups, they cannot be recycled together. In order to be recycled they have to be separated or de laminated which is not possible at all. Hence the end of life (natural breakdown to elemental form) of these packaging materials suspended in the environment can be a few hundred years to several thousand years. This would also occupy a very large landfill space.
Places where there is segregation of waste at source, these laminates would be subjected to incineration treatment. Here the cost of collection and disposal is very high with a negative output on disposal, as a very high amount of energy is utilized to incinerate the laminates. In most cases the laminates contain wet waste and this would consume a lot of energy to evaporate the liquid/water.
Since Paper has an inherent property of biodegradability under appropriate conditions and more attractive alternatives to simple land-filling have received increased attention. Among these primarily is the process of composting in which the waste(either post consumer or trims and factory waste) is degraded to Carbon dioxide ,water and biomass or Humus under accelerated and controlled conditions of moisture ,air and micro-organisms. Thus the mass of the waste is significantly reduced and the biomass acts as a fertilizer, soil conditioner and mulch for land and agriculture applications.
Paper packaging materials are manufactured by coating the paper or paper
board with resins or synthetic polymeric materials mostly Poly ethylene(PE) or
Poly propelene(PP).
The advantages of these coatings are seen in the following points.
A. Heat sealibility for the packaging material
B. Barrier properties from Moisture
C. Barrier to oxygen and other ambient gases

D. Vapor barriers to retain fragrances, flavours etc.
E. Printability in some cases as the polymer coating may act as a surface
smoothner in case of base papers to provide attractive non functional graphics.
Such constructions meet certain limited requirements in terms of barrier properties, however such constructions are compostable only to the degree to which the cellulose pulp(as in paper) is present. Under composting conditions the pulp fibers would be expected to decompose leaving a residue of BIOLOGICALLY INERT PLASTIC thereby spoiling the quality of compost.
Object of the invention
It is therefore the object of the invention to overcome these and other difficulties encountered in the prior art.
1 Given the current solid waste management problems another object of the invention is to provide a flexible packaging material that has the required barrier properties from oxygen and water vapor and will also degrade to Carbon dioxide and Bio-mass under composting conditions.
2. In poor waste management systems, most of the synthetic polymeric flexible packaging materials are scattered into the land and seas as litter and may take several hundred years to several thousands of years to degrade. Hence another object of invention is to provide a packaging materia! that would degrade in a relatively short span of time in the littered condition as well.

3. A further object of the invention is to provide as an environmentally improved alternative to plastic, a completely degradable and compostable flexible packaging material.
4. Another objective of the invention is to provide a flexible packaging material that can be re pulped with paper hence recycled. This should be possible with both the post consumer form as well as factory waste form.
5. Another objective of the invention is to provide the barrier properties of aluminum metal using a very thin coating of the metal which is by the means of vapor deposition technique( thickness in nano meters) hence reduce the resource utilization of metal to 700- 1000 times lesser than the usage of Aluminum foil .Here the vapor of aluminum is sandwiched between two layers of biopolymers hence giving the metal a sufficient coat weight for film formation and thereafter covering it with another bio polymer layer.
6. Another objective of the invention is to provide a very good bonding between the paper and certified compostable bio polymers without the usage adhesive thereby using a technique called as extrusion coating wherein the bonding between the two surfaces id by means of surface energy enhancement by means of corona treatment.
7. Another object of the invention is to have a sufficient bonding between the metalized surface and the certified bio compostable polymer without the usage of synthetic non-compostable adhesive.

Description of the Invention
The current invention relates to a bio-compostable flexible packaging material that is made up of a 100% compostable paper coated with a barrier layer and a sealant layer. The current invention overcomes the poltutive problems of synthetic packaging materials yet maintaining the same barrier properties required for the packaged products. The current invention is both re-pulpable with paper (hence recyclable) as well as 100% compostable as per the standard composting requirement and is given for testing.
The said compostable flexible packaging material is unique since it utilizes a very thin layer of aluminum that is vacuum deposited on a bio-compostable polymer that is extrusion coated on a base paper. Hence we have a paper based flexible packaging material that has a very thin aluminum layer (nanolayer) sandwiched between two biopolymer layers and all the layers are bonded without any lamination adhesive.{This is unlike the various paper based packaging materials using aluminum foil which is adhesive laminated to paper and the sealant layer). The barrier to water vapour is created by the vacuum metalized layer of aluminum and to provide the barrier properties of aluminum metal using a very thin coating of the metal which is by the means of vapor deposition technique( thickness in nano meters) hence reduce the resource utilization of metal to 700- 1000 times lesser than the usage of Aluminum foil Here the vapor of aluminum is sandwiched between two layers of biopolymers hence giving the metal a sufficient coat weight for film formation and thereafter covering it with another bio polymer layer.

Description of the drawings:
1. Figure 1 : "Prior art 1" shows a structure called PET(poly ethylene terepthalate) reverse printed with Ink and adhesive laminated to a multi layered polyethylene,
2. Figure 2 : Prior art 2" illustrates a high barrier structure for flexible packaging having PET or BOPP layer adhesive laminated to a metalized PET or Metalized BOPP layer further adhesive laminated to a multi layer or co extruded poly ethylene layer.
3. Figure 3: The concept and invention design/ structure or Invention 1 which illustrates a vacuum deposited metallic layer or similar barrier layer sandwiched between two biopolymer layers.
4. Figure 4: (Invention 2) Invention design/structure including primers and anchor coats for better adhesion.
(Conclusion. Ramification and scope of the invention)
The advantages of this type of compostaple packaging material over the conventional synthetic flexible packaging materials are.
1. The synthetic packaging materials cannot be recycled and have to be incinerated hence consume a lot of energy for disposal. The said compostable packaging material can be re-pulped with paper as the Co-polyester and polylactic acid based material will act as a binder in the paper forming process. Hence the material becomes 100% recyclable with paper.

2. The said bio-compostabie flexible packaging material is made by using all the ingredients that are 100% compostable and bIodegradable. The paper which is made from wood pulp is compostable element, the bio polymer is a certified compostable and biodegradable material, and the metal used is a nano layer and has no effect in the composting process and is retained in the elemental form in the nature as the other materials undergo a composting process.
3. There is no usage of adhesives since most of the adhesives are PU (poly urethane) based and are mostly non Bio- degradable and non compostable. Also the presence of an adhesive may increase the process of degradation of the structure. The absence of adhesives means that the layers are bound only by the adhesion which was created by the molten polymers and the cohesive forces between the two layers.

4. By using PLA as a material the usage of Fossil carbon is reduced as PLA is made from a 100% renewable source like sugarcane and com starch .while the synthetic packaging materials have a 100% fossilcarbon base.
5. The said packaging material uses paper as filler and Body and utilizes the best properties of the biopolymers like good heat sealability, moisture barrier and optimum utilization of the aluminum metal- A very thin deposition is only required to achieve barriers quite similar to those achieved by aluminum foil where the aluminum metal is a valuable resource.
Detailed description of the invention
The following detailed description illustrates embodiments of the present invention along with the processing method; however, it is not intended to limit

the scope of the appended claims in any manner. It is to be understood that changes and modifications may be made therein as will be apparent to those skilled in the art. Such variations are to be considered within the scope of the invention as defined in the claims.
The basic concept of the packaging material of the present disclosure includes:
1. A biodegradable paper substrate having two surfaces, and
2. A biodegradable polymer structure coated on at least one surface of the paper-based substrate.
3. A barrier layer positioned on at least one side of the biodegradable polymer coated surface.
4. The barrier layer being derived of metal layer.
5. A barrier layer is sandwiched between a biodegradable polymer structure having coated on at least one side of the paper-based substrate and a biodegradable polymer coated sealant layer.
FIG. 4- is a schematic illustration showing one embodiment of the disclosed packaging material including a biodegradable polymeric paper-based substrate having coated biodegradable polymer positioning on at least one side of the paper-based substrate and a barrier layer sandwiched between at least one surface of the structure of the coated layer and the biodegradable sealant layer.
The detailed description of the processing methods for the invention is elaborated below:-
1. A non-synthetic paper substrate having opposite sides which may be Kraft, one side clay coated Map-litho, Glassine etc, is taken in roll form. The grammage of the paper may be in the range of 30 to 70 gram per square meters. This high

starch paper is specially constructed having at least one rough side. The other side of the paper may be prepared smooth and printer friendly which may or may not have clay coated surface. The moisture content of the paper must be in the range of 5 to 6 percent. This paper is then taken further for extrusion coating on at least one side of the paper. The material to be extrusion coated is a biodegradable compostable polymer which may be selected from a group of Polylactide acids, Polybutylene adipate co-terepthalate, aromatic co-polyesters, (Polylactide, 1,4-Benzenedicarboxylic acid, 1,4-dimethyl ester, polymer with 1,4-butanediol and decanedioic acid), co-polyester of tetramethylene glycol with long chain dicarboxylic acid. The biodegradable compostable polymer, henceforth called as biopolymer, is extruded on the rough side of the paper substrate.
2. To enhance the adhesion between the paper substrate and biopolymer coating, the rough side of the paper may or may not be pre-coated with a primer. Please refer to Figure no. 5 for product. This primer is selected from group of Poly ethylene imine, Ethylene acrylic acid, Epotal etc.
3. The biopolymer coated paper substrate is further passed through a vacuum metallizer where a thin nano barrier layer is deposited on the biopolymer coated surface.. The barrier metal layer may be vapor deposited in the biopolymer coating layer by any known metal deposition methods. Examples of these methods include, but are not limited to, atomic layer deposition, chemical vapor deposition, physical vapor deposition, thermal spray coating, plasma spray, ion beam techniques, sputtering etc.

4. The biopolymer coated paper substrate deposited with the barrier layer is then
further extrusion coated with a biodegradable compostable sealant layer. The
may be selected from a group of Starch Polycaprolactum polymer blends, modified com starch with Copolyester etc.
5. To enhance the adhesion between the barrier layer and biopotymer sealant
layer coating, the barrier layer side of the biopotymer coated paper substrate
may or may not be pre-coated with a top-coat primer. Please refer to Figure no.
5. This primer is selected from group of Poly ethylene imine, Ethylene acrylic
acid, Epotal etc.



The above graph shows the barrier properties (Moisture Vapor Transmission Rate & Oxygen Transmission Rate) of the invention at various stages of development.
In the 1st stage, a biodegradable compostable paper substrate is taken and this biodegradable compostable paper substrate is then coated with a biodegradable compostable biopolymer by extrusion coating process. This biopolymer coated biodegradable compostable paper substrate is tested for barrier properties using standard Mocon WVTR& OTR testing equipment. The WVTR of the biopolymer coated biodegradable compostable paper substrate is around 220 the OTR of the biopolymer coated biodegradable compostable paper substrate is around 1400, as referred in the above graphs.

in the 2nd stage, the biopolymer coated biodegradable compostable paper substrate is then deposited with a barrier layer i.e. a nano-coating of metal layer by metallization process. The biopolymer coated biodegradable compostable paper substrate with the metal deposition is subjected to WVTR &OTR tests the results are in 12 and 59 respectively, as referred in the above graphs.
In the 3rd stage, The metal layer is top coated with a primer and the barrier properties are tested by WVTR &OTR tests, the results are 3 and 16 respectively.
In the final stage, biopolymer coated biodegradable compostable paper substrate with the metal deposition and topcoat is again extrusion coated with a biodegradable compostable sealant layer. This final structure henceforth referred to as product' is the tested for MVTR & OTR tests. The result of the product shows MVTR in the range of 0.5 and OTR in the range of 6, as referred in the above graphs. This is the acceptable range of packaging standards for high barrier flexible packaging for various food product, liquid, cosmetics etc.
With constant improvements in the technology and structural design of the invention, the desired barrier in the range of MVTR & OTR of less than 1 can be achievable, as referred in the above graphs.

We Claim :
1. A bio- compostable packaging material having two sides.providing the base as
paper having an externa! surface and an internal surface. Treating at least the
internal surface with corona discharge or flame or Priming or all of these or in
combination with two of three, coating at least the internal surface with a
biopolymer using the extrusion coating process giving a coat weight of 5
grams per square meters to 35 grams per square meters. This coating must
be capable of preventing leaks.The extrusion coated side thereafter will be
metalized with either the crucible type process or boat type process of
metallization or physical vapor deposition.
The metalized surface is thereafter covered with a 2nd layer of biopolymer again using the extrusion coating technique.
2. A bio-compostable packaging material in claim 1 wherein a barrier layer is positioned on at least one side of the packaging material. The barrier layer being derived from a sandwiched layer of vacuum deposited aluminum metal layer between two layers of biopolymer wherein the said layers of biopolymers are extrusion coated over the paper surface and the said Aluminum metal is a vacuum deposited nano layer which is further covered by the second layer of bio polymer material using the extrusion coating process.
3. A bio-compostable packaging material in claim 1 wherein the extrusion coating grade biopolymer material may be selected from a group of Polylactic acids, Polybutyleneadipate co-terepthalate, aromatic co-polyesters, Benzenedicarboxylic acid, dimethyl ester, polymer with butanediol and decanedioic acid, Co-polyester of tetramethylene glycol with long chain dicarboxylicdiacids, and their combination thereof.
4. A bio-compostable packaging material in claim 1 wherein the barrier metal layer may be vapor deposited in the biopolymer coating layer by any known

metal deposition methods including but not limited to like, atomic layer deposition, chemical vapor deposition, physical vapor deposition, thermal spray coating, plasma spray, ion beam techniques, sputtering etc.
5. A bio-compostable packaging material in claim 1 wherein the barrier layer is a vapor deposition layer of pure Aluminum metal or Melamine or SiOx or AI2O3 having a thickness of 1500 angstrom or less.
6. A bio-compostable packaging material in claim 1 wherein the base material used is paper not limited to but possibly a non-synthetic paper which may be Kraft, one side clay coated Map-litho, Glassine,C1S wood free base or related papers mostly taken in roll form or reel form.
7. A bio-compostable packaging material in claim 1 wherein the said bio-compostable material is made from any certified bio-compostable polymer adhering to the standards of either EN13432 or ASTM D6400 or ISO 17088 or Green PLA of Japan.
8. A bio-compostable packaging material in claim 1 wherein all the primers used will be mostly compostable or if having non compostable content will be less than 1% in weight of the total.
9. A bio-compostable packaging material in claim 1 wherein the material will have one printing surface and one sealing surface.
10. A bio-compostable packaging material in claim9 wherein the printing surface may be made of a clay coated or carbonate mixed with binder coated to enhance the printing ability of the paper and the sealing surface will be made of the biopolymer layer.

11. A bio-compostable packaging material in claim 1 wherein the said paper will be a non synthetic paper and possibly but not restricted to having a paper made from sustainable forestry requirement.
12. A bio-compostable packaging material in claim 1 wherein the vacuum deposited barrier layer which may be described in claim 5 is sandwiched between 2 biopolymer layers thereby givind the sandwiched barrier layer a form of a very thin film and hence creating the required barrier to moisture and oxygen.
13. A bio-compostable packaging material in claim 1 wherein the entire structure created will be either used bio-compostable dexible packagion material for dry and semi liquid packaging with thinner construction or by changing the thickness and type of the paper base can also be used in the more rigid forms of packaging materials. In the second case the bio polymer may further be coated over the printed surface hence can form constructions like tetra brick(non Aseptic) for fresh liquid foods with a very less shelf life.