FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13) Gulmohar Pack-Tech India Pvt. Ltd.
Sr. No. 80/11, Plot No. 1, Bhosari Alandi Road,
Dighi MagzineChowk, Behind Pragati Hotel,
Pune - 412105, Maharashtra, India
MULTIFUNCTIONAL HYBRID NANOCOMPOSITE BASED POLYMER
PACKAGING MATERIAL
The following specification particularly describes the invention and the manner in which
it is to be performed

MULTIFUNCTIONAL HYBRID NANOCOMPOSITE BASED POLYMER
PACKAGING MATERIAL
This application is filed as Complete Application in the Indian Patent Office.
Field of the Invention
The present invention is aimed to provide multifunctional hybrid nanocomposite packaging material that will have application as anticorrosion, antistatic, EMI shielding, antimicrobial, Oxygen scavenger, H2S absorber, UV-Absorption, Improved Food freshness, Improved barrier properties. The process of preparing such multifunctional hybrid nanocomposite based polymer packaging material is also disclosed.
Background of the Invention
In the globalized modern era packaging materials play a critical role in improving product shelf-life. Such packaging materials are manufactured in combination with other material/ products to achieve multifunctional activity, for example in protection from environment and stress, safety, identification, efficiency, convenience as well as improved packaging. The present invention finds application in the packaging and logistic industry where packaging of metal parts, instruments and electronic materials and food products are involved. While storing or transporting metal parts, instruments or electronic materials protection from corrosive environment, static charge generation, Electromagnetic Interference, microbial attack, UV radiation are factors that are important. The present invention is with regard to a novel packaging material with multifunctional activities wherein the metal products or instruments that are susceptible to corrosion may be protected from corrosive environments such as chlorine, sulfur, oxidation and so on containing moieties by using of packaging or wrapping.
US5154886 provides a specific polymer material for handling, shipping, and storage of integrated circuits wherein the circuit is protected from both corrosion and electrostatic discharge. The enclosure material includes a polymer matrix with both carbon black and a metal embedded. The metals of the invention, herein, include copper, iron, cobalt, and manganese.

WO2013178525 provides a low environmental impact hydrocarbon-based film for corrosion protection comprising metallic nanoparticles with specific surface area higher than 10m2/g, preferably 40m2/g.
From what is available in the packaging industry, it appears that there is a need to develop a multifunctional material with diverse properties which can protect the product from a variety of environmental factors.
Summary of the Invention
The present invention relates to novel multifunctional hybrid nanocomposite based packaging material that is used in the packaging industry and preparation of the said packaging material.
The novel multifunctional packaging material of the invention protects metal parts/ electronic materials from corrosion, damage due to static charge deposition, electromagnetic interference (EMI), microbial attack, oxidising agents, UV-radiation and so on in addition to improved food freshness (when the product packaged is food) and improved barrier properties.
In one aspect, the invention provides a multifunctional hybrid nanocomposite based
packaging material comprising metal powders blended with film forming polymers.
In another aspect, the invention provides a multifunctional hybrid nanocomposite based
packaging material comprising metal powders blended with thermoplastic polymers.
The aforesaid multifunctional hybrid nanocomposite further consists of precipitated silica,
oxides of inorganic metal and conducting polymer.
The metal powders are selected from the group of metals consisting of silver, aluminium,
copper, nickel and iron. The concentration of the metal powder ranges from 0.1% to 30%
and the particle size ranging from lOOnm to 10 micron.
In yet another aspect of the invention, the thermoplastic polymer of the invention is Low
Density Polyethylene (LDPE), Linear Low Density Polyethylene (LLDPE) or
Polypropylene (PP).
In another aspect, the oxides of inorganic metal is ZnO, TiC^, CaCC>3 or SiC>2.

The invention also provides conducting polymers that are synthesized using monomers selected from the group consisting of pyrrole, thiophene and aniline, to produce conjugated polymers.
The polymers are selected from the group consisting of polypyrrole, polythiophene and polyaniline. The conjugated polymers comprise long chain sulfonic acid or phosphonic acid. The sulfonic acid is selected from the group consisting of methane sulfonic acid, lauryl benzene sulfonic acid, benzene sulfonic acid, dodecyl benzene sulfonic acid and dodecane benzene sulfonic acid. The phosphonic acid is selected from the group consisting of phosphonic acid, phenyl phosphonic acid, n-decylphosphonic acid, dodecylphosphonic acid, hexylphosphonic acid and tetradecylphosphonic acid. The nanocomposite of the invention is made at a melting temperature of the polymers ranging from 160°C-230°C and the said nanocomposite material has tensile strength in the range of 100-300 Kg/cm2.
The nanocomposite material of the invention has modulus in the range of 400-1000%. The invention also provides a process of preparing multifunctional hybrid nanocomposite based packaging material comprising the steps of:
a) dry mixing polymer granules with metal powder, nanomaterials and processable doped conducting polymers;
b) melt mixing the mixture of (a) in twin screw extruder at a melting temperature of the polymer to obtain a continuous thread;
c) The continuous thread obtained in step (b)is shred/cut and made into pellets of size in the range of 3 mm to 6 mm in length and 3mm to 4 mm diameter;
d) The pellets are used to make films by blown extrusion method.
The multifunctional hybrid nanocomposite based packaging material is used for packaging of metal parts, electronic materials and food substances.
Brief Description of Figures
Figure 1. (A) Hybrid composite polymer film before exposure to HC1 vapour; (B) The
composite film after exposure to HC1 vapour for 15 hours.

Figure 2. Hybrid composite polymer film (A) before exposure to H2S gas; (B) Composite film after exposure to H2S gas for 10 minutes; (C) Composite film after exposure to H2S gas for 20 minutes.
Figure 3. Hybrid composite polymer film (A) before and (B) after 10 hours of exposure to NH3 gas.
Detail Description of the Invention
The present invention provides a multifunctional hybrid nanocomposite based packaging material that is used in the packaging industry.
The present invention also provides a process of preparing a multifunctional hybrid composite film that finds application as anticorrosive, antistatic and antimicrobial packaging material. In addition the multifunctional hybrid composite film also exhibits the following properties:
- EMI (Electromagnetic Interference) shielding
- Oxygen scavenger
- H2S gas absorption
- HC1 gas absorption
- NH3 gas absorption
- antimicrobial
- UV absorption
Furthermore the packaging material of the present invention improves food freshness and improves barrier property.
In one embodiment, the base polymer for the packaging film material is chosen from a range of thermoplastic polymer which includes but not limited to Low Density Polyethylene, Linear Low Density Polyethylene, Polypropylene and so on. The role of the polymer material is to translate into shape(s) and structure(s) as well as render a barrier property. The polymer in the present invention also protects the objects inside the packaging film in such a way that the packaged object does not lose its property when exposed.

In one aspect, the polymer of choice is mixed with metal powder to make the composite. The metal powder is selected from a group of metals consisting of Silver, Aluminium, Copper, Nickel and Iron. The metal powder herein serves as a barrier by sealing the micro pores in the packaging films. Metal powder can act as active sites for blocking or for absorbing different gases. Metal particles such as Silver, Aluminium, Copper, Nickel, Iron and so on are also known for their antimicrobial behaviour. The packaging films prepared by using these polymer metal composites thus have antimicrobial activity measured by antimicrobial assay (See Table 6)
Metal powder concentration as provided herein ranges from 0.1% to 30%.
Metal powder particle size as provided herein is in the range of 100 nm to 10 micron.
In another embodiment of the invention, the composite films were prepared using different oxides of inorganic materials are also used. The inorganic oxides are selected from the group consisting of ZnO, Ti02, CaCO3 and SiO2.
The concentration of nanoparticle as meant in this invention ranges from 0.1% to 25%.
The particle size of ZnO, TiO2, CaCO3, SiO2 is in the range of lOnm to 10 micron.
The antibacterial and UV blocking properties of oxide of Zinc is well documented (Goh et al, Scripta Materialia 49: 78, 2014; Rajagopalan and Khanna, J of Scientific and Research Publications, 3: 1, 2013). Zinc Oxide (ZnO) is also used as an in gradient to remove hydrogen sulfide (H2S) which is considered to be one of the corrosive gases. ZnO is also considered to have odour removal property. Incorporation of ZnO also improves mechanical, water vapor barrier and thermal stability.
Ti02 is considered to have antimicrobial activityas reported previously. (Verdier et al, Coatings 4:670, 2014). TiO2 also absorbs UV light. It helps in minimising degradation of the packaging for example degradation due to embrittlement, fading and cracking.
The inventors of the present invention have used CaC03 as one of the materials due to the advantages it offers in as seen in other applications. CaCO3 is used in breathable film applications in hygiene, medical and roofing markets (US5855999, US6264864). Introduction of CaCO3 in the present invention improves the hardness, stiffness and

impact strength in extruded film. CaCO3 eliminates the negative catalytic effect on the aging of polymers (Kwon et al., Polymer 43: 6901,2002). In addition, CaCO3 has low refractive index and high whiteness which can help in reduction of consumption of expensive abrasive pigments such as titanium dioxide. Another advantage of low abrasiveness material is that it contributes to low wear and tear in the extrusion machine parts such as extruder screws and cylinders.
On the other hand incorporation of SiO2 in packaging film improves gas barrier and heat resistance property (Olmos et al. European Polymer Journal, 47:1495, 2011). It also improves mechanical properties of the film such as high tensile strength and Young's modulus.
In a preferred embodiment, electronically conducting polymer is synthesized using a range of monomers selected from the group consisting of pyrrole, thiophene and aniline, to obtain conjugated polymers selected from the group consisting of polypyrrole, polythiophene and polyaniline (Modak et al. Procedia Materials Science 10:588,2015). Schematic 1 provides the electronically conductive polymers used in the multicomposition.
Schematic 1

The uniquely synthesized processable conjugated polymers of the invention are prepared using long chain sulfonic acid or phosphonic acid. Examples of sulfonic acid include but not limited to methane sulfonic acid, lauryl benzene sulfonic acid, benzene sulfonic acid, dodecyl benzene sulfonic acid and dodecane benzene sulfonic acid. Similarly, examples of phosphonic acid include but not limited to phosphonic acid, phenyl phosphonic acid, n-decylphosphonic acid, dodecylphosphonic acid, hexylphosphonic acid and tetradecylphosphonic acid.
The particle size of the synthesised conducting polymers is in the range of 10 nm to 100 micron.
Conducting polymer percentage in the composite is in the range of 0.1 % to 25%.
Conducting polymers are selected from the group consisting of polypyrrole,
polythiophene and poly aniline.
The invention provides a process of preparing the multifunctional hybrid composite films disclosed in this specification.
In one embodiment the present invention provides a process of preparing multifunctional hybrid composite films; The process comprises the steps of:

a) dry mixing polymer granules with metal powder, nano materials and processable doped conducting polymers.
b) Melt mixing the mixture of (a) in twin screw extruder at a melting temperature of the polymer to obtain a continuous thread
c) The continuous thread obtained in step (b)is shred/cut and made into pellets of size in the range of 3 mm to 6 mm in length and 3mm to 4 mm diameter.
d) The pellets are used to make films by blown extrusion method.
In another embodiment of the invention, the process of making composite films uses conductive carbon black. The function of structural self-sensing, electromagnetic shielding and thermal interfacing of carbon materials (Chung, Carbon 50:3342, 2012) has been utilized in developing composite films. Concentration of conductive carbon black is in the range of 0.1 % to 25%.
Composites are made at melting temperature of the polymers, preferably at 160°C-230°C by twin screw extruder. Schematic 2 provides the process of preparing hybrid composite material. Schematic 2

Films are made by blown film extrusion process. Thickness of the films is in the range of 25 micron to 250 micron.These composite films have tensile strength in the range of 100-300 Kg/cm2is prepared modulus is in the range of 400-1000%(See Table 3).
Nanomaterials, as provided in the present invention includes but not limited to ZnO, Ti02s CaC03, Si02 A12O3, CuO, Cu20, MgO, NiO, ln203, Zr02.
Dopants influence the property of conducting polymers. Properties such as conductivity, procesibility, solubility, particle size are dependent on dopants. Doped conducting polymers were used for making the films to tailor the properties of the polymers.
These multifunctional hybrid composite material when exposed to NH3 gas, changes its colour from brown to black. These packaging material when exposed to HC1 vapour, changes its colour from brown to yellow and when exposed to H2S gas, changes its colour from brown to black. Change of colour indicates that the corrosive gas present in the atmosphere is absorbed by the metal particle and neutralize the gas. Change in colour is also due to decrease in corrosion protection abilities of the film. The colour change is also indicative of saturation.
Uses of the Invention
The utility of this invention is to protect the material packaged from the following:
- microbial attacks, that is growth of microbes on the metal surface
- corrosion caused by microbial attacks and corrosive gases
- electromagnetic interference
- damages caused due to static charges
- support in reducing UV absorption
- improve food freshness in cases where the packaged material is a food article
- improve barrier properties
The foregoing examples are set forth for better understanding of the embodiments and are not to be construed to limit the invention in any way.

Example 1. Preparation of polymer metal composites and films using Blown Film extrusion method
The detail procedure of preparing the multifunctional packaging film of the invention is given below. At first master batch of the composition is prepared. For making master batch of the composite, 4975g of LDPE Polymer (Low Density Polyethylene, Reliance Packaging Grade: 24FS040) was dry mixed with 25 g of ultra-fine Copper powder (Supplied by P.P. Patels, Solapur, Maharashtra, India) for 15 minutes. Once mixed properly, it was poured in the feeder of the twin screw extruder (Inventa Technologies, Chennai). Twin Screw Extruder was kept fixed at 350RPM. The temperatures at different zones of the Twin Screw Extruder is accounted in Table 1. The polymer composite molten thread coming out from the extruder was allowed to pass through water tank attached to it. The thread was then passed through automatic cutter machine to make granules of the composite. Size of the granules is in the range of 3 mm to 6 mm in length and 3 mm to 4 mm diameter. Table 1. Table of Temperatures at different Zones of Twin Screw Extruder

Zone Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7
Temperature (°C) 160 160 180 190 190 200 200
These master batch granules were further used to make composites films using Blown Film extrusion machine.
For making plastic films, 6kg of LLDPE (Linear Low Density Polyethylene, Indian Oil Corporation Limited IOCL, Grade Propel 010F18S), 3.5kg of LDPE (Reliance Grade 24FS040) and 0.5kg of master batch is physically mixed well. This was then poured in the feeder of Blown film extrusion machine (Subham extrusion Technik, Ahmedabad, Gujarat). The temperature at different zone of the extrusion machine is given in Table 2. Films of 80 micron thickness was prepared. The width of films was 12 inches .Colour of the extruded blown films was brown in colour.
Table 2. Temperatures at different zones of Blown Film extruder machine

Zone
Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6
Temperature 200°C 190°C 185°C 180°C 170°C 165°C
Example 2. Preparation of composites and films using Blown Film extrusion method
Herein, 4970g of LDPE Polymer (Low Density Polyethylene, Reliance Packaging Grade: 24FS040) was dry mixed with 25g of ultra fine Copper powder ( Supplied by P. P. Patels, Solapur, Maharashtra, India ) and 5 g of precipitated Silica (Mansill75, Synthetic Amorphous Silica) for 15 minutes. It was then mixed in the twin screw extruder, detailed procedure of which is given in the Example 1. All other conditions are same as explained in the Example 1. These master batch granules were used to make composites films using Blown Film extrusion machine.
For making plastic film, 9.5 kg of LDPE (Reliance Grade 24FS040) and 0.5kg of master batch was physically mixed well. This is then poured in the feeder of Blown Film extrusion machine. The temperature at different zone of the extrusion machine is given in Table 2. Films of 80 micron thickness was prepared. The width of films was 12 inches. Colour of the extruded blown films was brown in colour.
Example 3. Preparation of polymer composites films
Herein, master batch of the composition is prepared by mixing, 4960g of LDPE Polymer (Low Density Polyethylene, Reliance Packaging Grade: 24FS040), 25g of ultra fine Copper powder, 5 g of precipitated Silica 5 g of ZnO and 5 g of Conducting Polyaniline. These masterbatch granules were used to make composites films using Blown Film extrusion machine.
For making plastic film, 9.5 kg of LDPE(Reliance Grade 24FS040) and 0.5kg of master batch was physically mixed well. This is then poured in the feeder of Blown film extrusion machine Colour of the extruded blown films was black in colour.
Example 4. Characterization of Films

The films were characterized by different techniques as followed:
Mechanical Property
The mechanical property of the films was studied. The tensile strength and elongation
testing of the films were carried out as per ASTM D882-02. Tensile strength testing was
carried out by Komputerised Universal Testing Machine, manufactured by Star Testing
Systems, Mumbai, India. The results for the films prepared in Example 1 are given in the
Table 3.
Table 3. Table of mechanical properties of the composite film

Sr.No Test Parameters Results Test method
1 Tensile Strength 143.5Kg/cm" ASTM D882-02
2 Elongation 600% ASTM D882-02
Films exposure with HCl gas
In a stoppered conical flask HCl vapour is taken. A plastic composite film of dimension 4 inches x 5 inches is kept inside the conical flask and allowed to HCl gas exposure. It was observed that with exposure to HCl gas, the colour of the film changes from brown to greenish and then to yellowish. In Figurel, the film exposed to HCl gas for 15 hours is shown.
Films exposure with H2S gas
A 4 inches x 5 inches piece composite film prepared by given in example 1 is cut and kept in a stoppered conical flask containing H2S gas. It was observed that after 20 minutes exposure to H2S gas, the colour of the film completely changes from brown to black which can be seen in the Figure 2.
Films exposure with NH3 gas
NH3vapour is takenin a stoppered conical flask where a small plastic composite film of dimension 3 inches x 0.5 inches is kept inside. It was observed that with exposure to NH3 vapour, the colour of the film changes from brown to blackish. In the Figure 3 film exposed to NH3 vapour for 10 hours is shown.

Salt spray tests
Anticorrosion salt fog spray tests are done to check the corrosion resistant effectiveness of the packets made out of the plastic films. For that purpose small coupon of dimemnsion 1 inch x 3 inches is kept inside the plastic packet of size 4 inches x 6 inches. Salt spray test was done per ASTM standard ASTM Bl 17-2011. The solution for salt spray was 5% NaCl. The pH of the solution was in the range of 6.8-7.2. The temperature of the test chamber was maintained 35 ± 2°C. The volume for collection of the liquid is in the range of 1.1 to 1.3 ml/hour. The experiment is performed for different duration. In case of packet prepared by film in Example 1, duration of salt spray testing is 168hrs whereas in case of packet prepared by film in Example 2, duration of salt spray testing is 528 hours. In both the cases the salt fog spray test as per ASTM Bl 17-2011 is passed by the packets. The details of the salts fog spray test are given in Table 4 and Table 5.
Table 4. Table of anticorrosion study of the composite film. Study period 168 hours.

Salt spray test 1
Duration in hours Observation on sample 1
24hrs Material surface found free from rust
48hrs Material surface found free from rust
72hrs Material surface found free from rust
96hrs Material surface found free from rust
120 hrs Material surface found free from rust
144 hrs Material surface found free from rust
168 hrs Material surface found free from rust
Table 5. Table of anticorrosion study of the composite film prepared as in Example 1 (Study period 528 hours)

Salt spray test 2
Duration in Hours Day no Observation on sample 2

24 hours
1 No rust on material surface
48 hours 2 No rust on material surface
72 hours 3 No rust on material surface
96 hours 4 No rust on material surface
120-240 hours 5-10 No rust on material surface
264 hours 11 No rust on material surface
288-480 hours 12-20 No rust on material surface
504 hours 21 No rust on material surface
528 hours 22 Red rust on material surface (Water vapor observed inside the plastic bag)
Antimicrobial activity assay
Antimicrobial tests were also performed of the plastic films for E. coli, S. aureus, Salmonella spp. and yeast & mould count was done as per standard IP 2014. The tests performed shows that these films exhibited antimicrobial activity. Detailed results are given in the Table 6. Table 6: Table of antimicrobial study of the composite film. Study period 144 hours

Sr.
No Parameters Results Units Standard method
1 E. coli Absent - IP 2014
2 S. aureus Absent - IP 2014
3 Salmonella spp Absent - IP 2014
4 Yeast & Mould count 1.0 cfu/gm IP 2014

Claims We Claim:
1. A multifunctional hybrid nanocomposite based packaging material comprising metal powders blended with film forming polymers
2. A multifunctional hybrid nanocomposite based packaging material comprising metal powders blended with thermoplastic polymers.
3. A multifunctional hybrid nanocomposite based packaging material comprising metal powders blended with film forming polymers and further consisting of precipitated silica.
4. A multifunctional hybrid nanocomposite based packaging material comprising metal powders blended with film forming polymers and further consisting of precipitated silica, oxides of inorganic metal and conducting polymer.
5. The multifunctional hybrid nanocomposite based packaging material of claim 1 or 2, wherein the said metal powders are selected from the group of metals consisting of silver, aluminium, copper, nickel and iron.
6. The multifunctional hybrid nanocomposite based packaging material of claim 1 or 2, wherein the said metal powder is copper.
7. The multifunctional hybrid nanocomposite based packaging material of claim 1 or 2, wherein the said film forming polymer is a thermostatic polymer.
8. The multifunctional hybrid nanocomposite based packaging material of claim 7, wherein the said thermostatic polymer is selected from the group consisting of LDPE, LLDPE and PP.
9. The multifunctional hybrid nanocomposite based packaging material of claim of 4, wherein the said oxides of inorganic metal is selected from the group consisting of ZnO, Ti02, CaC03, and Si02.
10. The multifunctional hybrid, nanocomposite based packaging material of claim of 4,
wherein the said conducting polymers are synthesized using monomers selected from the
group consisting of pyrrole, thiophene and aniline, to produce conjugated polymers.
The multifunctional hybrid nanocomposite based packaging material of claim of 10, wherein the polymers are selected from the group consisting of polypyrrole, polythiophene and polyaniline,

11. The multifunctional hybrid nanocomposite based packaging material of claim of 10, wherein the said conjugated polymers comprise long chain sulfonic acid or phosphonic acid.
12. The multifunctional hybrid nanocomposite based packaging material of claim of 11, wherein the sulfonic acid is selected from the group consisting of methane sulfonic acid, lauryl benzene sulfonic acid, benzene sulfonic acid, dodecyl benzene sulfonic acid and dodecane benzene sulfonic acid.
13. The multifunctional hybrid nanocomposite based packaging material of claim of 11, wherein the phosphonic acid is selected from the group consisting of phosphonic acid, phenyl phosphonic acid, n-decylphosphonic acid, dodecylphosphonic acid, hexylphosphonic acid and tetradecylphosphonic acid.
14. The metal powder of claim 1, wherein the said metal powder is in the concentration ranging from 0.1% to 30% and the particle size ranging from lOOnm to 10 micron.
15. The conducting polymers of claim 4, wherein the said polymer percentage in the nanocomposite is in the range of 0.1% to 25% and the particle size of the polymer is in the range of lOOnm to 10 micron.
16. The multifunctional hybrid nanocomposite based packaging material of claim of 1, wherein the said nanocomposite is made at a melting temperature of the polymers ranging from 160°C-230°C.
17. The multifunctional hybrid nanocomposite based packaging material of claim of 1, wherein the said nanocomposite material has tensile strength in the range of 100-300 Kg/cm2.
18. The multifunctional hybrid nanocomposite based packaging material of claim of 1, wherein the said nanocomposite material has modulus in the range of 400-1000%.
19. A process of preparing multifunctional hybrid nanocomposite based packaging material comprising the steps of:

(a) dry mixing polymer granules with metal powder, nano materials and processable doped conducting polymers;
(b) melt mixing the mixture of (a) in twin screw extruder at a melting temperature of the polymer to obtain a continuous thread;
(c) The continuous thread obtained in step (b)is shred/cut and made into pellets of size in the range of 3 mm to 6 mm in length and 3 mm to 4 mm diameter;

(d) The pellets are used to make films by blown extrusion method.
20. A multifunctional hybrid nanocomposite based packaging material, the said packaging
material used for packaging of metal parts, electronic materials and food substances.
21. A multifunctional hybrid nanocomposite based packaging material, the said packaging
material comprising the properties of protecting metal parts/ electronic materials from
corrosion, damage due to static charge deposition, electromagnetic interference (EMI),
microbial attack, oxidising agents, UV-radiation and improving food freshness and barrier
properties.