DESC:FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

MULTILAYER PACKAGING FILM

APPLICANT:
RELIANCE INDUSTRIES LIMITED
an Indian Company
of 3rd Floor, Maker Chamber-IV
222, Nariman Point, Mumbai-400021,
Maharashtra, India.

Inventors:

1) SAMANTAPUDI VENKATARAMA RAJU; 2) JADHAV KISHOR SHANKAR;
2) 3) DONGRE TUSHAR JAYWANT

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

FIELD
The present disclosure relates to packaging films. Particularly, the present disclosure relates to multilayer packaging films.

BACKGROUND
The technology of milk packaging has evolved significantly over the years due to the exponential technological advancement coupled with increased awareness about the superior nutritive value of milk and milk derivatives. From refillable glass bottles to plastic pouches and now to paper cartons, the packaging technologists are striving to ensure that milk reaches a maximum consumer base.

However, in spite of the availability of user friendly packaging materials, the milk that is contained therein does not remain potable for longer durations. Emergence of ultra-high-temperature (UHT) processing techniques have attempted to enhance the shelf life of milk, but a characteristic burnt taste that accompanies UHT milk has marred the consumer compliance. Extended Shelf Life (ESL) milk is a new variety of processed milk having a highly improved shelf life which is prepared by subjecting milk to high temperatures, accompanied by a controlled filling environment and container sterilization; thereby making ESL milk a highly sought after milk variety. Consequently, packaging of ESL milk, which although is an emerging concept in the dairy industry, is gathering serious momentum.

The packaging material that has currently been developed and used for packaging ESL milk is multilayered and is typically three or seven layered. The seven layered packaging materials are expensive, whereas the three layered ones fall short of offering the most effective thickness to oxygen transmission rate ratio. The present disclosure therefore provides a multilayer packaging film for the packaging and storage of ESL milk that mitigates the drawbacks associated with the present technologies.

OBJECTS
Some of the objects of the present disclosure, which at least one embodiment is able to achieve, are discussed herein below.
It is an object of the present disclosure to provide packaging films.
It is another object of the present disclosure to provide multilayer packaging films.
It is yet another object of the present disclosure to provide multilayer packaging films which have improved barrier properties.
It is still another object of the present disclosure to provide multilayer packaging films which are economical and environment friendly.
It is yet another object of the present disclosure to provide packaging articles from the multilayer films.
It is still another object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Other objects and advantages of the present disclosure will be more apparent from the following description and accompanying drawing which is not intended to limit the scope of the present disclosure.

SUMMARY
The present disclosure provides a multilayer packaging film comprising:
i. a first layer comprising:
a. metallocene linear low density polyethylene (LLDPE) in an amount ranging from 15 to 45% of the total mass of the first layer,
b. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, and
c. low density polyethylene (LDPE) in an amount ranging from 15 to 45% of the total mass of the first layer;
ii. a second layer comprising:
a. high density polyethylene (HDPE) in an amount ranging from 10 to 100% of the total mass of the second layer,
b. metallocene LLDPE in an amount ranging from 0 to 90% of the total mass of the second layer,
c. butene LLDPE in an amount ranging from 0 to 90% of the total mass of the second layer,
d. LDPE in an amount ranging from 0 to 90% of the total mass of the second layer,
e. titanium dioxide in an amount ranging from 0 to 30% of the total mass of the second layer,
f. carbon black in an amount ranging from 0 to 20% of the total mass of the second layer, and
g. optionally, at least one organic salt in an amount ranging from 50 to 1000 ppm with respect to the total mass of the second layer; and
iii. a third layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
b. LDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
c. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
d. HDPE in an amount ranging from 30 to 60% of the total mass of the third layer, and
e. titanium dioxide in an amount ranging from 0 to 30% of the total mass of the third layer.
Typically, the proportion of the thickness of said first layer to said second layer to said third layer is 1:1:1 and the oxygen transmission rate of the multilayer packaging film of the present disclosure ranges from 1200 to 2600 cc/m2/ day at 90 microns thickness and from 700 to 1000 cc/m2/ day at 110 microns thickness.

BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will now be described with reference to accompanying non-limiting drawings, wherein:
Figure 1 illustrates the multilayer packaging film of the present disclosure, wherein:
A represents a first layer;
B represents a second layer; and
C represents a third layer.

DETAILED DESCRIPTION
The present disclosure provides a multilayer film for packaging perishable products such as milk that typically consists of three layers where typically the proportion of the thickness of the first layer to the second layer to the third layer is 1:1:1 Permutations and combinations of polyethylene having different densities along with certain additives are used to prepare the multilayer films of the present disclosure. The specific proportion and type of constituents in each layer synergistically imparts the desired resistance to gas permeability and light transmission; thereby resulting in an extended shelf life of the perishable product packed therein.
The first layer of the packaging film includes metallocene linear low density polyethylene (LLDPE) in an amount ranging from 15 to 45% of the total mass of the first layer, butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer and low density polyethylene (LDPE) in an amount ranging from 15 to 45% of the total mass of the first layer. Typically, all the constituents are homogenized to form the first layer.
The second layer of the packaging film includes high density polyethylene (HDPE) in an amount ranging from 10 to 100% of the total mass of the second layer, metallocene LLDPE in an amount ranging from 0 to 90% of the total mass of the second layer, butene LLDPE in an amount ranging from 0 to 90% of the total mass of the second layer, LDPE in an amount ranging from 0 to 90% of the total mass of the second layer, titanium dioxide in an amount ranging from 0 to 30% of the total mass of the second layer, carbon black in an amount ranging from 0 to 20% of the total mass of the second layer and optionally at least one organic salt in an amount ranging from 50 to 1000 ppm with respect to the total mass of the second layer. Typically, all the constituents are homogenized to form the second layer.
The third layer of the packaging film includes metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer, LDPE in an amount ranging from 15 to 45% of the total mass of the third layer, butene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer, HDPE in an amount ranging from 30 to 60% of the total mass of the third layer and titanium dioxide in an amount ranging from 0 to 30% of the total mass of the third layer. Typically, all the constituents are homogenized to form the third layer.
The oxygen transmission rate of the multilayer packaging film of the present disclosure depends on thickness of the film. When the thickness of the film is 90 microns, the oxygen transmission rate ranges from 1200 to 2600 cc/m2/ day and when the thickness is 110 microns, the oxygen transmission rate ranges from 700 to 1000 cc/m2/ day.
In a first embodiment, the three layer packaging film of the present disclosure includes metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer and LDPE in an amount ranging from 15 to 45% of the total mass of the first layer; HDPE in an amount ranging from 10 to 30% of the total mass of the second layer, metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the second layer, butene LLDPE in an amount ranging from 10 to 30% of the total mass of the second layer, LDPE in an amount ranging from 15 to 45% of the total mass of the second layer and titanium dioxide in an amount ranging from 10 to 30% of the total mass of the second layer and metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer, butene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer, LDPE in an amount ranging from 15 to 45% of the total mass of the third layer.
In a second embodiment, the three layer packaging film of the present disclosure includes metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer and LDPE in an amount ranging from 15 to 45% of the total mass of the first layer; HDPE in an amount ranging from 10 to 30% of the total mass of the second layer, metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the second layer, butene LLDPE in an amount ranging from 10 to 30% of the total mass of the second layer, LDPE in an amount ranging from 15 to 45% of the total mass of the second layer, titanium dioxide in an amount ranging from 10 to 30% of the total mass of the second layer and carbon black in an amount ranging from 5 to 20% of the total mass of the second layer and metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer, butene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer, LDPE in an amount ranging from 15 to 45% of the total mass of the third layer and titanium dioxide in an amount ranging from 10 to 30% of the total mass of the third layer.
In a third embodiment of the present disclosure, the three layer packaging film includes metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer and LDPE in an amount ranging from 15 to 45% of the total mass of the first layer; HDPE in an amount ranging from 30 to 60% of the total mass of the second layer, metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the second layer, LDPE in an amount ranging from 15 to 45% of the total mass of the second layer, titanium dioxide in an amount ranging from 10 to 30% of the total mass of the second layer and carbon black in an amount ranging from 5 to 20% of the total mass of the second layer and metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer, HDPE in an amount ranging from 30 to 60% of the total mass of the third layer, LDPE in an amount ranging from 15 to 45% of the total mass of the third layer and titanium dioxide in an amount ranging from 10 to 30% of the total mass of the third layer.
In a fourth embodiment of the present disclosure the three layer packaging film includes metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer and LDPE in an amount ranging from 15 to 45% of the total mass of the first layer; HDPE in an amount ranging from 30 to 60% of the total mass of the second layer, metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the second layer, LDPE in an amount ranging from 15 to 45% of the total mass of the second layer, titanium dioxide in an amount ranging from 10 to 30% of the total mass of the second layer, carbon black in an amount ranging from 5 to 20% of the total mass of the second layer and at least one organic salt in an amount ranging from 50 to 1000 ppm with respect to the total mass of the second layer and metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer, HDPE in an amount ranging from 30 to 60% of the total mass of the third layer, LDPE in an amount ranging from 15 to 45% of the total mass of the third layer, and titanium dioxide in an amount ranging from 10 to 30% of the total mass of the third layer.
The present disclosure also provides an article prepared from the multilayer packaging film of the present disclosure. The article provided in the present disclosure is selected from the group consisting of pouch, container, can, bottle, crate, box, sachet, lid, bag, jar and canister.
The present disclosure will now be discussed in the light of the following non-limiting embodiments:
Example 1: Process for the preparation of the multilayered film of the present disclosure
40 grams of metallocene LLDPE, 40 grams of butene LLDPE, 20 grams of LDPE were admixed to form a first layer admixture. 40 grams of HDPE, 30 grams of metallocene LLDPE, 15 grams of LDPE, 10 grams of titanium dioxide, 5 grams of carbon black and 100 grams of an organic salt were admixed to for a second layer admixture. Similarly, 30 grams of metallocene LLDPE, 40 grams of HDPE, 20 grams of LDPE and 10 grams of titanium dioxide were admixed to form a third layer admixture. The three admixtures so prepared were fed in the hoppers of respective layer extruders of a three layer blown film plant. The material extruded out in the form of a three layer film of desired thickness at a blow up ratio of 1:9:1. The film was passed on-line through corona treatment for improving the printability of the outer surface of the film. A corona treatment of 40-44 dyne was given to the outer surface. The film was slit open on the edges before winding, resulting in two separate rolls, the rolls were converted in to flat film. The film obtained was shifted to the printing station for printing the art work related to the product to be packed. The film was slit into required size on the slitter and rewinder machine after the printing and then was dispatched to the dairy for filling operation.
Example 2: Shelf life testing
Shelf lives of products packed in films of Embodiments 3 and 4 prepared in accordance with the present disclosure were compared to that of the commercially available films. Similarly, the opacity and oxygen transmission rate (OTR) were also compared. The results obtained are presented in Table 1.
Table 1. Properties of the multilayer films of the present disclosure
Sr. No. Sample Thickness
(Microns) Opacity
(%) Oxygen transmission rate
(cc/m2/day) Dart impact strength
(g/microns)
1 Commercially available film A 90 72 4330 2.5
2 Commercially available film B 90 70 > 5500 1.9
3 Embodiment 3 90 100 2540 1.4
4 Embodiment 4 90 100 1250 1.4
5 Commercially available film C 110 100 1200 1.9
6 Embodiment 3 110 100 890 1.4

The shelf life of the products packed in films of Embodiment 3 and 4 was found to be around 39 days; whereas that of the products packed in commercial films is around 20 to 25 days. Thus, it is evident that the packaging film of the present disclosure improves the shelf life of the products packed therein.
It is thus evident that the multilayer films prepared in accordance with the present disclosure are better in terms of opacity, OTR and dart impact strength as compared to the commercially available films.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE
The multilayer films of the present disclosure have the following advantages:
- the films have a low oxygen transmission rate; thereby extending the shelf life of the products stored in the multilayer film;
- properties such as opacity and dart impact strength are also improved as compared to the commercially available films

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention and the claims unless there is a statement in the specification to the contrary.
While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications in the process or compound or formulation or combination of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
,CLAIMS:We Claim:
1. A multilayer packaging film comprising:
i. a first layer comprising:
a. metallocene linear low density polyethylene (LLDPE) in an amount ranging from 15 to 45% of the total mass of the first layer,
b. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, and
c. low density polyethylene (LDPE) in an amount ranging from 15 to 45% of the total mass of the first layer;
ii. a second layer comprising:
a. high density polyethylene (HDPE) in an amount ranging from 10 to 100% of the total mass of the second layer,
b. metallocene LLDPE in an amount ranging from 0 to 90% of the total mass of the second layer,
c. butene LLDPE in an amount ranging from 0 to 90% of the total mass of the second layer,
d. LDPE in an amount ranging from 0 to 90% of the total mass of the second layer,
e. titanium dioxide in an amount ranging from 0 to 30% of the total mass of the second layer,
f. carbon black in an amount ranging from 0 to 20% of the total mass of the second layer, and
g. optionally, at least one organic salt in an amount ranging from 50 to 1000 ppm with respect to the total mass of the second layer; and
iii. a third layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
b. LDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
c. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
d. HDPE in an amount ranging from 30 to 60% of the total mass of the third layer, and
e. titanium dioxide in an amount ranging from 0 to 30% of the total mass of the third layer,
2. The multilayer packaging film as claimed in claim 1, wherein the proportion of the thickness of said first layer to said second layer to said third layer is 1:1:1.
3. The multilayer packaging film as claimed in claim 1, being characterized by oxygen transmission rate ranging from 1200 to 2600 cc/m2/ day at 90 microns thickness.
4. The multilayer packaging film as claimed in claim 1, being characterized by oxygen transmission rate ranging from 700 to 1000 cc/m2/ day at 110 microns thickness.
5. A multilayer packaging film as claimed in claim 1, comprising:
i. a first layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer,
b. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, and
c. LDPE in an amount ranging from 15 to 45% of the total mass of the first layer;
ii. a second layer comprising:
a. HDPE in an amount ranging from 10 to 30% of the total mass of the second layer,
b. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the second layer,
c. butene LLDPE in an amount ranging from 10 to 30% of the total mass of the second layer,
d. LDPE in an amount ranging from 15 to 45% of the total mass of the second layer, and
e. titanium dioxide in an amount ranging from 10 to 30% of the total mass of the second layer, and
iii. a third layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
b. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
c. LDPE in an amount ranging from 15 to 45% of the total mass of the third layer.
6. A multilayer packaging film as claimed in claim 1, comprising:
i. a first layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer,
b. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, and
c. LDPE in an amount ranging from 15 to 45% of the total mass of the first layer;
ii. a second layer comprising:
a. HDPE in an amount ranging from 10 to 30% of the total mass of the second layer,
b. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the second layer,
c. butene LLDPE in an amount ranging from 10 to 30% of the total mass of the second layer,
d. LDPE in an amount ranging from 15 to 45% of the total mass of the second layer,
e. titanium dioxide in an amount ranging from 10 to 30% of the total mass of the second layer, and
f. carbon black in an amount ranging from 5 to 20% of the total mass of the second layer; and
iii. a third layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
b. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
c. LDPE in an amount ranging from 15 to 45% of the total mass of the third layer; and
d. titanium dioxide in an amount ranging from 10 to 30% of the total mass of the third layer.

7. A multilayer packaging film as claimed in claim 1, comprising:
i. a first layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer,
b. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, and
c. LDPE in an amount ranging from 15 to 45% of the total mass of the first layer;
ii. a second layer comprising:
a. HDPE in an amount ranging from 30 to 60% of the total mass of the second layer,
b. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the second layer,
c. LDPE in an amount ranging from 15 to 45% of the total mass of the second layer,
d. titanium dioxide in an amount ranging from 10 to 30% of the total mass of the second layer, and
e. carbon black in an amount ranging from 5 to 20% of the total mass of the second layer; and
iii. a third layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
b. HDPE in an amount ranging from 30 to 60% of the total mass of the third layer,
c. LDPE in an amount ranging from 15 to 45% of the total mass of the third layer, and
d. titanium dioxide in an amount ranging from 10 to 30% of the total mass of the third layer.
8. A multilayer packaging film as claimed in claim 1, comprising:
i. a first layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer,
b. butene LLDPE in an amount ranging from 15 to 45% of the total mass of the first layer, and
c. LDPE in an amount ranging from 15 to 45% of the total mass of the first layer;
ii. a second layer comprising:
a. HDPE in an amount ranging from 30 to 60% of the total mass of the second layer,
b. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the second layer,
c. LDPE in an amount ranging from 15 to 45% of the total mass of the second layer,
d. titanium dioxide in an amount ranging from 10 to 30% of the total mass of the second layer,
e. carbon black in an amount ranging from 5 to 20% of the total mass of the second layer, and
f. at least one organic salt in an amount ranging from 50 to 1000 ppm with respect to the total mass of the second layer; and
iii. a third layer comprising:
a. metallocene LLDPE in an amount ranging from 15 to 45% of the total mass of the third layer,
b. HDPE in an amount ranging from 30 to 60% of the total mass of the third layer,
c. LDPE in an amount ranging from 15 to 45% of the total mass of the third layer, and
d. titanium dioxide in an amount ranging from 10 to 30% of the total mass of the third layer.
9. An article prepared from the multilayer packaging film as claimed in claim 1, said article being selected from the group consisting of pouch, container, can, bottle, crate, box, sachet, lid, bag, jar and canister.