Biaxially oriented moldable sealable and non-sealable films and methods of making same

Abstract

The present invention relates to a biaxially oriented sealable and non-sealable polyester film of a multilayer structure B / B / A, comprising: (a) an outer layer B; (b) an intermediate layer B; and (c) an inner layer A. The present invention also relates to a method for preparing a biaxially oriented sealable polyester film as described herein. The biaxially oriented and non-sealable flexible polyester film of the present invention has enhanced mechanical properties, i.e. Tensile, elongation, dart impact, tear resistance, as well as better stretchability, high temperature stability, and high seal strength, low seal initiation temperature.

Description

Technical Field

[0001] The present invention relates to formable flexible sealable and non-sealable transparent biaxially oriented polyester films. In particular, the present invention relates to biaxially oriented sealable and non-sealable polyester films of multilayer structure B / B / A, which are characterized by high seal strength, good cold and hot formability properties and high temperature dimensional stability. The present invention also relates to a process for preparing the biaxially oriented sealable and non-sealable polyester films as described herein. Background Art

[0002] Multilayer films or laminates are used to package articles such as food products, electronic products or drugs in multilayer films or laminates to protect these packaged articles from mishandling and external contamination. Formable films are well known in the industry for packaging food, blister packaging, medical products, electronic products and industrial products. These formable films for packaging articles provide good printability, stretchability, barrier properties, clarity, mechanical properties, flame retardancy and resistance to ultraviolet light (UV). Formable films provide cost-effective packaging and easy handling of packaging materials, and ensure safe transportation and delivery to end users.

[0003] Forming is the process of converting a monolayer film, a multilayer film, a single material laminate, a multi-material laminate or a sheet, etc., into a mold of a desired shape by pressure molding or vacuum forming techniques. The simplest thermoforming process consists of heating a plastic sheet to its forming temperature and mechanically pressing it against a cooled solid shape called a mold. There are many variations and improvements to this simple thermoforming process. Such variations are used in large-format thermoforming rather than in small-format thermoforming processes, and the main reason for this is that thicker sheets maintain their formable temperature for a longer time. This allows more manipulation of the hot sheet before it is pressed against the mold surface. During this process, heat is lost very quickly from the thin sheet, and as a result, the thin sheet is formed faster. Therefore, the films produced by methods known in the art have a normal thickness range, i.e., 8μ to 75μ. In addition, these conventional films are produced with pigments such as silica, UV masterbatch, polyester sheets and combinations thereof. These films are produced by sequential biaxial orientation extrusion processes.

[0004] Cold-formable and heat-formable films are well known in the art and are found in a variety of different applications. In the case of vacuum forming or compressed air forming or the mechanical action of a die head, it is known that the film has formability (stretching) under hot and cold conditions. Typical film materials used for forming are polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), and especially polycarbonate (PC). In addition, multilayer film systems (PS / ethylene-vinyl alcohol copolymer (EVOH) / polyethylene (PE) or PP / EVOH / PE, and PE / EVOH / PE) are often used in food packaging applications because such systems are known to have good heat-sealing properties or vapor barriers for improved preservation properties. Typical application areas for formed films are meat or poultry, blisters, hard shell boxes, furniture or metal lamination (tank linings).

[0005] For example, referring to US2021 / 0301126 A1, it is composed of a biaxially oriented formable polyethylene terephthalate (PET) film having a multilayer layer A / B / A structure capable of thermoforming or cold forming. The film includes at least two outer layers A. The disclosed film can be thermoformed above its glass transition temperature (Tg) and below its melting temperature (Tm), and can be cold formed under ambient temperature and pressure conditions.

[0006] Reference is further made to US 11,041,056 B2 which describes a transparent biaxially oriented thermoformable polyester film comprising at least 85 wt% of a copolyester of which the dicarboxylic acid component is derived from 85 to 94 mol% of units based on terephthalic acid and from 6 to 15 mol% of units based on isophthalic acid.

[0007] Reference is also made to 2021 / 0395446A1, which relates to a crystallizable shrinkable film and a thermoformable film or sheet comprising a blend of a polyester composition comprising residues of terephthalic acid, neopentyl glycol (NRG), 1,4-cyclohexanedimethanol (CHDM), ethylene glycol (EG) and diethylene glycol (DEG), having certain advantages and improved properties within certain composition ranges. However, the films disclosed therein are not suitable for high temperature applications because these films have high shrinkage problems, which results in more losses.

[0008] Reference is also made to US2021 / 0292076 A1, which comprises a package having a laminate having the following substantially coextensive layers in the following order: (a) a non-sealable self-supporting thermoformable copolyester film layer having a first surface and a second surface, the second surface constituting the outermost exposed surface of the laminate; (b) a laminating adhesive layer on the first surface of the thermoformable copolyester film layer; and (c) a self-supporting thermoformable structural film layer having a first surface and a second surface, the first surface being in contact with the laminating adhesive layer. However, the film disclosed therein comprises a laminate of two different types of non-recyclable polymer films.

[0009] Although various efforts have been made to use biaxially oriented PET films in packaging applications, these conventional formable biaxially oriented PET films and methods of making the films, including those described above, have major disadvantages such as: (a) barrier properties and mechanical strength; (b) are not sealable; (c) do not exhibit good dimensional stability; and (d) do not provide a single family of multi-layer laminates, such as the printed PET film / adhesive / sealable film of the invention.

[0010] Therefore, there is a pressing need in the art to provide formable films that include a combination of desirable properties such as high mechanical strength (e.g., tensile, toughness, and elongation), better optical properties; balanced shrinkage in the longitudinal and machine directions at elevated temperatures, high temperature dimensional stability, puncture resistance; dart impact strength, better stretchability, cost effectiveness, better barrier properties, high seal strength at low seal initiation temperatures; and the ability to replace multilayer laminates with improved barrier properties. Purpose of the Invention

[0011] The main object of the present invention is to provide biaxially oriented formable sealable and non-sealable films of multilayer structure B / B / A.

[0012] It is another object of the present invention to provide a process for preparing the biaxially oriented sealable and non-sealable films as described herein. Summary of the invention

[0013] The present invention discloses biaxially oriented sealable and non-sealable films of multilayer structure B / B / A, comprising: (a) outer layer B; (b) middle layer B; and (c) inner layer A, wherein outer layer B and middle layer B contain at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and wherein inner layer A contains at least one component selected from the group consisting of at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, MBUV polymer, SH3-M polymer and combinations thereof. The present invention also discloses a cost-effective method for preparing biaxially oriented sealable and non-sealable films as described herein. The biaxially oriented polyester film as described herein has high seal strength at low seal initiation temperature and exhibits high mechanical strength, optical properties, stretchability (forming), and high temperature stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings constitute a part of the specification and are used to provide a further understanding of the present invention. Such drawings illustrate embodiments of the present invention and together with the description are used to describe the principle of the present invention.

[0015] Figure 1 Depicted is a diagram of the structure of a biaxially oriented non-sealable polyester film of multilayer structure B / B / A as described in Examples 1 and 2 of the present invention in accordance with one embodiment of the present invention.

[0016] Figure 2 Depicted is a diagram of the structure of a biaxially oriented sealable polyester film of multilayer structure B / B / A as described in Inventive Example 3 according to one embodiment of the present invention.

[0017] Figure 3 A conventionally known membrane in the prior art according to one embodiment of the present invention is depicted.

[0018] Figure 4 Laminate structures comprising the film of the present invention according to one embodiment of the present invention are depicted: (a) high barrier laminate; (b) high barrier aluminum foil-based laminate; and (c) single layer sustainable film structure (d) sustainable single family multilayer laminate for packaging. DETAILED DESCRIPTION

[0019] Although the present invention may have various modifications and alternative forms, its specific embodiments will be described in detail below. However, it should be understood that it is not intended to limit the present invention to the specific forms disclosed, but on the contrary, the present invention will cover all modifications, equivalents and alternatives falling within the scope of the present invention defined by the appended claims.

[0020] Although one or more features and / or elements may be described herein only in the context of a single embodiment, or alternatively in the context of more than one embodiment, or alternatively in the context of all embodiments, the features and / or elements may alternatively be provided individually or in any suitable combination or not at all. Conversely, any features and / or elements described in the context of separate embodiments may alternatively be implemented as being present together in the context of a single embodiment.

[0021] The terms used herein are only used for the purpose of describing specific multiple embodiments, and are not intended to limit multiple embodiments. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the / said" are intended to also include plural forms.

[0022] The term "biaxially oriented formable sealable polyester film" refers to a film that is stretched in both the machine direction and the transverse direction to produce molecular chain orientation in both directions. The film of the present invention is a "flexible formable film", which means that the film can be thermoformed and cold formed on commercially available thermoforming or cold forming machines with good flexibility or without loss of properties.

[0023] As used herein, the term "thermoforming" and variations thereof refer to pressure forming, vacuum forming, and die forming.

[0024] As used herein, the term "cold forming" and variations thereof refer to stretching without being subjected to heat.

[0025] The term "sealable film" refers to a film with high seal strength that can be used as a monolayer bag or as a sealant layer in a laminate.

[0026] The term "filler" refers to an inorganic material added to a polymer to enhance its mechanical and functional properties.

[0027] The term "modified thermoplastic polyethylene terephthalate (PET) polymer" refers to a PET polymer whose properties have been modified. The composition of the modified PET polymer comprises a combination of purified terephthalic acid (PTA), ethylene glycol (EG) and DEG (diethylene glycol). The presence of the modified PET polymer is important for improving the percentage of elongation and other functional properties of the film of the present invention.

[0028] The term "UV resistant masterbatch (MBUV) polymer" refers to a polymer comprising a mixture of 75% to 85% PET polymer and 15% to 25% of a premix, wherein the premix is ​​a mixture of a UV absorber and an antioxidant.

[0029] The term "heat sealable masterbatch or SH3-M" polymer refers to a polymer that is a blend of 70% to 90% PET and 10% to 30% isophthalic acid (IPA).

[0030] The term "dart impact resistance" refers to the ability of the films of the present invention to absorb high magnitude impacts.

[0031] The term "low seal initiation temperature" means the lowest temperature at which a particular seal strength level is obtained.

[0032] As used herein, the term "forming" is a process of transforming a single-layer film, a multi-layer film, a single material laminate, a multi-material laminate or a sheet, etc. into a mold of a desired shape by pressure molding or vacuum forming technology.

[0033] As discussed in the Background of the Invention section, conventional biaxially oriented PET films have major disadvantages such as uniform stretching and dimensional stability during thermoforming or cold forming.

[0034] To overcome the aforementioned problems, the present invention provides a biaxially oriented sealable polyester film of multilayer structure B / B / A, which has a desired set of properties, such as high mechanical strength, stretchability, high temperature stability, balanced shrinkage, and barrier properties and high seal strength properties at low seal initiation, etc. The sealable film of the present invention is particularly noteworthy for having good cold formability and hot formability, and for having excellent barrier and heat sealable properties after forming. In addition, the film of the present invention also exhibits excellent optical properties, especially high clarity, wherein the haze is less than 1.5%, and the gloss is greater than 120, and the clarity is greater than 88%.

[0035] In particular, the present invention discloses a biaxially oriented sealable and non-sealable polyester film of a multilayer structure B / B / A, comprising: (i) an outer layer B; (ii) an intermediate layer B; and (iii) an inner layer A, wherein the outer layer B and the intermediate layer B comprise at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and wherein the inner layer A comprises at least one component selected from the group consisting of at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, MBUV polymer, SH3-M polymer and combinations thereof. The presence of modified thermoplastic polyethylene terephthalate (PET) polymer and fillers such as silica is essential for obtaining a film having desired functional properties in terms of friction and sealability as well as good mechanical properties. In addition, in the absence of any of the layers (B / B / A) in the film, the functional and mechanical properties of the film are affected. The good mechanical properties of the film include a strength of more than 1300 Kg / cm in the longitudinal direction (MD). 2 Up to 1500Kg / cm 2 ; In the transverse direction (TD) greater than 1400Kg / cm 2 Up to 1750Kg / cm 2 The film also has excellent elongation properties in the machine direction (MD) and transverse direction (TD), which are in the range of 140 to 200 and 130 to 180, respectively. The film also has a low sealing initiation temperature in the range of 90°C to 100°C at 0.8 kg / cm 2 Up to 1.4kg / cm 2 The film has excellent sealing strength in the range of . The film also shows good moisture resistance and oxygen permeability. The thickness of the film is in the range of 8μ to 75μ. In addition to the above properties, the film also has the following properties: (i) excellent dart impact resistance in the range of 220gf to 850gf (meaning the ability to absorb high-level impact); (ii) puncture resistance in the range of 6N to 9N; (iii) glass transition temperature (Tg) and melting temperature (Tm) values ​​of 78.2 to 78.7 and 246.9 to 247.8, respectively; (iv) sealing initiation temperature in the range of 90°C to 100°C. The presence of the modified PET polymer is essential to obtain such a film: it exhibits stretchability in the range of 10mm to 17mm and exhibits enhanced structural and functional properties compared to films without any modified PET polymer.

[0036] The film of the invention, characterized by high transparency, has a low filling degree (i.e., a lower concentration of antiblocking agents (i.e., silica) as a result of which the film of the invention has good winding and processing qualities. During winding and unwinding of the film, the individual layers of the film may not adhere to each other even at elevated temperatures, e.g., 40° C. or 50° C.

[0037] The present invention also discloses a cost-effective process for preparing biaxially oriented sealable and non-sealable polyester films of multilayer structure B / B / A, the films having good longitudinal and transverse orientation, resistance to UV, high temperature dimensional stability and excellent heat seal strength at low seal initiation temperatures. The dimensional stability of the films provides a cavity of uniform thickness during film formation.

[0038] Due to the cold forming and hot forming properties of the film, the film of the present invention is used for packaging applications, wherein the film is formed into a desired packaging design by applying pressure to the mold at ambient temperature via cold forming and a hot forming process performed above the glass transition temperature and below its melting temperature. Thermoforming is performed in the film to a depth of 10 mm to 20 mm. Due to the high sealing strength, the film of the present invention can be used as a single-layer bag or as a sealant layer in a laminate. Therefore, the biaxially oriented sealable and non-sealable polyester film of the multilayer structure B / B / A is particularly useful for the following: pharmaceutical packaging applications, more particularly, blister packaging is for example used for capsules, tablets, ideally for cooked meat, cut meat, poultry or fish, or dry products such as wrapping paper, fresh protein, frozen food, sliced ​​cheese packaging, ideally for syringes, tablet packaging, dental instrument boxes, etc., as is or with a laminate structure. Preferably, the biaxially oriented sealable and non-sealable polyester film of the laminate structure is particularly useful for food packaging applications as is or with a laminate structure. The films of the present invention are also useful for monolayer sustainable packaging or to make sustainable recyclable laminates with additional polyester films.

[0039] Depending on the product requirements, the biaxially oriented sealable and non-sealable polyester films of the multilayer structure B / B / A can also be coated with a polymer material selected from polyvinyl alcohol (PVOH) / ethylene-vinyl alcohol copolymer (EVOH) / polyvinylidene chloride (PVDC) to improve barrier properties. The film is also optionally coated with an adhesion promoter or a functional polymer coating (acrylic primer coating). High sealing strength means that the film can be used as a single-layer bag or as a sealant layer in a laminate to replace sealable biaxially oriented polypropylene film / blown polyethylene film / cast polypropylene film (BOPP / PE / CPP / ). The film of the present invention can also replace biaxially oriented nylon film and PVC film for cavity stretching.

[0040] Furthermore, the biaxially oriented sealable and non-sealable polyester films of the multilayer structure B / B / A can be recycled without polluting the environment. Thus, the films of the invention from recycled or virgin materials do not exhibit practically impaired mechanical and other properties when compared to films produced from virgin PET materials. The films of the invention also contain a UV stabilizer, i.e. a light stabilizer which is a UV absorber.

[0041] In one embodiment of the present disclosure, a biaxially oriented sealable and non-sealable polyester film of a multilayer structure B / B / A is provided, comprising: (i) an outer layer B; (ii) an intermediate layer B; and (iii) an inner layer A, wherein the outer layer B and the intermediate layer B contain at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and wherein the inner layer A contains at least one component selected from the group consisting of: at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, MBUV polymer, SH3-M polymer and combinations thereof.

[0042] In one embodiment of the present invention, a biaxially oriented sealable and non-sealable film as described herein is provided, wherein the combined weight percentage of thermoplastic polyethylene terephthalate (PET) polymers is in the range of 55% to 75% relative to the film. In another embodiment of the present invention, the combined weight percentage of thermoplastic polyethylene terephthalate (PET) polymers is in the range of 58% to 73% relative to the film. In yet another embodiment of the present invention, the combined weight percentage of thermoplastic polyethylene terephthalate (PET) polymers is in the range of 60% to 70% relative to the film. In another embodiment of the present invention, the combined weight percentage of thermoplastic polyethylene terephthalate (PET) polymers is in the range of 63% to 68% relative to the film.

[0043] In one embodiment of the present invention, there is provided a biaxially oriented sealable and non-sealable film as described herein, wherein the weight percentage of the modified PET polymer is in the range of 30% to 45% relative to the film. In another embodiment of the present invention, the weight percentage of the modified PET polymer is in the range of 32% to 43% relative to the film. In yet another embodiment of the present invention, the weight percentage of the modified PET polymer is in the range of 35% to 40% relative to the film. In another embodiment of the present invention, the weight percentage of the modified PET polymer is in the range of 38% to 40% relative to the film.

[0044] In one embodiment of the present invention, there is provided a biaxially oriented sealable and non-sealable film as described herein, wherein the filler has a combined weight percentage in the range of 0.03% to 0.08% selected from silica. In another embodiment of the present invention, the combined weight percentage of fillers is in the range of 0.04% to 0.07%. In yet another embodiment of the present invention, the combined weight percentage of fillers is in the range of 0.05% to 0.07%.

[0045] In one embodiment of the present invention, a biaxially oriented sealable and non-sealable polyester film of a multilayer structure B / B / A is provided, comprising: (i) an outer layer B; (ii) an intermediate layer B; and (iii) an inner layer A, wherein the outer layer B and the intermediate layer B comprise at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and wherein the inner layer A comprises at least one component selected from the following: at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, MBUV polymer, SH3-M polymer and combinations thereof, wherein the combined weight percentage of the thermoplastic polyethylene terephthalate (PET) polymer is in the range of 55% to 75% relative to the film, and wherein the weight percentage of the modified PET polymer is in the range of 30% to 45% relative to the film, and wherein the filler in the range of 0.03% to 0.08% by weight is selected from silica.

[0046] In one embodiment of the present invention, there is provided a biaxially oriented sealable and non-sealable film as described herein, wherein the weight percentage of MBUV polymer in the range of 0.5% to 2% relative to the film comprises 75% to 85% of PET polymer and 15% to 25% of a premix comprising a blend of UV absorbers and antioxidants. In another embodiment of the present invention, the weight percentage of MBUV polymer in the range of 0.7% to 1.5% relative to the film. In yet another embodiment of the present invention, the weight percentage of MBUV polymer in the range of 0.8% to 1.2% relative to the film.

[0047] In one embodiment of the present invention, there is provided a biaxially oriented film as described herein, wherein the weight percentage of the SH3-M polymer is in the range of 10% to 30%. In another embodiment of the present invention, the weight percentage of the SH3-M polymer is in the range of 12% to 28%, or 15% to 25%, or 18% to 22%, wherein the SH3-M polymer comprises a blend of 70% to 90% PET and 10% to 30% isophthalic acid (IPA).

[0048] In one embodiment of the present invention, there is provided a biaxially oriented sealable and non-sealable film as described herein, wherein the thermoplastic polyethylene terephthalate (PET) polymer comprises: (i) 70% to 80% purified terephthalic acid (PTA); (ii) 20% to 30% ethylene glycol (EG); and (iii) 1% to 2% diethylene glycol. In another embodiment of the present invention, the thermoplastic polyethylene terephthalate (PET) polymer comprises: (i) 72% to 75% purified terephthalic acid (PTA); (ii) 22% to 27% ethylene glycol (EG); and (iii) 1.2% to 2% diethylene glycol.

[0049] In one embodiment of the present invention, there is provided a biaxially oriented sealable and non-sealable film as described herein, wherein the modified PET polymer comprises: (i) 65% to 85% purified terephthalic acid (PTA); (ii) 20% to 30% ethylene glycol (EG); and (iii) 4% to 10% diethylene glycol. In another embodiment of the present invention, the modified PET polymer comprises: (i) 68% to 82% purified terephthalic acid (PTA); (ii) 22% to 27% ethylene glycol (EG); and (iii) 5% to 9% diethylene glycol.

[0050] In one embodiment of the present invention, a biaxially oriented sealable and non-sealable polyester film of a multilayer structure B / B / A is provided, comprising: (i) an outer layer B; (ii) an intermediate layer B; and (iii) an inner layer A, wherein the outer layer B and the intermediate layer B comprise at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and wherein the inner layer A comprises at least one component selected from the group consisting of at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer. (PET) polymers, MBUV polymers and combinations thereof, wherein the combined weight percentage of thermoplastic polyethylene terephthalate (PET) polymers is in the range of 55% to 75% relative to the film, and wherein the weight percentage of modified PET polymers is in the range of 30% to 45% relative to the film, and wherein the combined weight percentage of fillers in the range of 0.03% to 0.08% is selected from silica, and wherein the MBUV polymer in the range of 0.5% to 2% weight percentage relative to the film comprises polymers and premixes.

[0051] In one embodiment of the present invention, a biaxially oriented sealable and non-sealable polyester film of a multilayer structure B / B / A is provided, comprising: (i) an outer layer B; (ii) an intermediate layer B; and (iii) an inner layer A, wherein the outer layer B and the intermediate layer B contain at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and wherein the inner layer A contains SH3-M, wherein the combined weight percentage of the thermoplastic polyethylene terephthalate (PET) polymer is in the range of 55% to 75% relative to the film, and wherein the weight percentage of the modified PET polymer is in the range of 30% to 45% relative to the film, and wherein the filler in the range of 0.03% to 0.08% is selected from silica, and wherein the weight percentage of the SH3-M polymer is in the range of 10% to 30%.

[0052] In one embodiment of the present invention, a biaxially oriented sealable and non-sealable polyester film of a multilayer structure B / B / A is provided, comprising: (i) an outer layer B; (ii) an intermediate layer B; and (iii) an inner layer A, wherein the outer layer B and the intermediate layer B comprise at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and wherein the inner layer A comprises at least one component selected from the group consisting of at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, MBUV polymer and combinations thereof, wherein the combined weight percentage of the thermoplastic polyethylene terephthalate (PET) polymer is in the range of 55% to 75% relative to the film. ET) polymer comprises: (a) 70% to 80% purified terephthalic acid (PTA); (b) 20% to 30% ethylene glycol (EG); and (c) 1% to 2% diethylene glycol (DEG), and wherein the modified PET polymer in the range of 30% to 45% by weight relative to the film comprises: (a) 65% to 85% purified terephthalic acid (PTA); (b) 20% to 30% ethylene glycol (EG); and (c) 4% to 10% diethylene glycol (DEG), and wherein the filler in the range of 0.03% to 0.08% by weight of the combined filler is selected from silica, and wherein the MBUV polymer in the range of 0.5% to 2% by weight relative to the film comprises polymer and premix.

[0053] In one embodiment of the present invention, a biaxially oriented sealable and non-sealable polyester film of a multilayer structure B / B / A is provided, comprising: (i) an outer layer B; (ii) an intermediate layer B; and (iii) an inner layer A, wherein the outer layer B and the intermediate layer B comprise at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and wherein the inner layer A comprises SH3-M, wherein the combined weight percentage of the thermoplastic polyethylene terephthalate (PET) polymer in the range of 55% to 75% relative to the film comprises: (a) 70% to 80% of the filler; and (b) 70% to 80% of the filler. 0% of purified terephthalic acid (PTA); (b) 20% to 30% of ethylene glycol (EG); and (c) 1% to 2% of diethylene glycol (DEG), and wherein the modified PET polymer in the range of 30% to 45% by weight relative to the film comprises: (a) 65% to 85% of purified terephthalic acid (PTA); (b) 20% to 30% of ethylene glycol (EG); and (c) 4% to 10% of diethylene glycol (DEG), and wherein the filler in the range of 0.03% to 0.08% by weight of the combined filler is selected from silica, wherein the weight percentage of the SH3-M polymer is in the range of 10% to 30%.

[0054] In one embodiment of the present invention, there is provided a biaxially oriented sealable and non-sealable film as described herein, wherein the thickness of the film is in the range of 8μ to 75μ. In another embodiment of the present invention, the thickness of the film is in the range of 10μ to 70μ, or 15μ to 65μ, or 20μ to 60μ, or 25μ to 55μ, or 30μ to 50μ, or 35μ to 45μ.

[0055] In one embodiment of the present invention, there is provided a biaxially oriented sealable and non-sealable film as described herein, wherein the film has a percent elongation in the longitudinal direction and the transverse direction in the range of 150 to 200 and 135 to 180, respectively. In another embodiment of the present invention, the film has a percent elongation in the longitudinal direction and the transverse direction in the range of 160 to 190 and 140 to 170, respectively. In yet another embodiment of the present invention, the film has a percent elongation in the longitudinal direction and the transverse direction in the range of 170 to 180 and 150 to 160, respectively.

[0056] In one embodiment, a method for preparing a biaxially oriented sealable and non-sealable film as described herein is provided, the method comprising: (i) feeding at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, at least one modified thermoplastic polyethylene terephthalate (PET) polymer into an extruder at a temperature in the range of 255° C. to obtain a first mixture; (ii) co-feeding at least one ingredient selected from at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, MBUV polymer into a co-extruder at a temperature in the range of 265° C. to obtain a second mixture. , SH3-M polymers and combinations thereof; (iii) laminating the first mixture of step (a) and the second mixture of step (b) in an extrusion die to produce a laminated molten structure; (iv) extruding the laminated molten structure of step (c) from a slit die and then quenching it to produce a film having a multilayer structure such as B / B / A; (v) stretching the film of step (d) in a longitudinal direction at a temperature in the range of 80°C to 95°C to produce a longitudinally oriented film; (vi) stretching the longitudinally oriented film of step (e) in a transverse direction at a temperature in the range of 110°C to 190°C to prepare a biaxially oriented film; and (vii) stretchability in the range of 10 mm to 17 mm.

[0057] In one embodiment of the present invention, there is provided an article comprising a biaxially oriented film as described herein, wherein the article is selected from the group consisting of sustainable recyclable laminate bags, packaging materials for pharmaceutical packaging applications and blister packaging applications.

[0058] The present invention is described in more detail below in conjunction with non-limiting exemplary embodiments according to the following examples: Example

[0059] The following examples are put forward to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the present invention, and are not intended to limit the scope of what the inventors regard as their invention, nor are they intended to represent that the following experiments are all and only experiments performed. Methods for preparing several preferred embodiments will become more clear through the working examples provided below.

[0060] The following examples describe biaxially oriented sealable and non-sealable films produced according to the process of the present invention, wherein the films have a B / B / A layered structure comprising a combination of polyethylene terephthalate, modified polyethylene terephthalate and silica as a filler. The thickness of the films of the present invention is 12 μm, 23 μm and 36 μm. Layer B accounts for 85% of the total layer thickness, while layer A accounts for 15% of the total layer thickness. The film with a suitable orientation of B / B / A, as well as the presence of modified PET polymers and fillers in the film are also important for achieving a film that exhibits excellent functional properties and mechanical properties (including high seal strength). Example 1: Composition of biaxially oriented thermoformable PET film

[0061] This example describes the composition of a biaxially oriented thermoformable non-sealable PET film 1 (referred to as Film 1) based on a multilayer structure B / B / A of thermoplastic polyethylene terephthalate, modified polyethylene terephthalate sheets and silica as filler. Figure 1 Film 1 is depicted, and the composition of film 1 is provided in Tables 1 and 2 below. The layered structure (B / B) of the film consists of a polyethylene terephthalate (PET) sheet, a modified polyethylene terephthalate sheet, and 750 ppm of silica as a filler. The thermoplastic polyethylene terephthalate contains: 73.5% purified terephthalic acid (PTA) + 25% ethylene glycol (EG) + 1.5% diethylene glycol (DEG), while the modified polyethylene terephthalate contains 71% PTA + 23% EG + 6.0% DEG. The innermost layer A contains 1500 ppm of silica and polyethylene terephthalate (PET) containing 73.5% PTA + 25% EG + 1.5% DEG.

[0062] Table 1: Composition of membrane 1

[0063] Table 2 shows the total weight percentage of the components present relative to Film 1

[0064] Referring to Table 2, the film 1 of the present invention includes 0.086% by weight of silicon dioxide, 61.7% by weight of a PET polymer, and 38.18% by weight of a modified PET polymer relative to the weight of the film. Example 2: Composition of a biaxially oriented thermoformable PET non-sealable film containing MBUV

[0065] The layered structure (B / B) upper and middle layers of the film of this example comprise the same composition as mentioned in Example 1. However, the innermost layer A comprises an anti-UV masterbatch (MBUV) polymer containing PET polymer + 18.08% of a premix (mixture of UV stabilizer and antioxidant) to protect the film of the present invention from ultraviolet (UV) radiation. The CAS numbers of the UV absorbers are: (1) 018600-59-4 and (2) 2725-22-6, while the CAS numbers of the antioxidants are: (1) 040601-76-1 and (2) 31570-04-4. The ratio of UV absorber to antioxidant is 1:1 (i.e., the weight percentage of each UV absorber and antioxidant is 50% each).

[0066] The membrane of this example is referred to as "Membrane 2 (also Figure 1 )", and its composition is provided in Tables 3 and 4 below.

[0067] Table 3: Composition of Membrane 2

[0068] Table 4 shows the total weight percentage of the components present relative to Film 2

[0069] Referring to Table 4, Film 2 of the present invention contains 0.086% of silica relative to the weight percentage of the film, 60.67% of PET polymer relative to the weight percentage of the film, 38.18% of modified PET polymer relative to the weight percentage of the film, and 1.05% of MBUV polymer relative to the weight percentage of the film. Example 3: Composition of a biaxially oriented thermoformable PET sealable film comprising SH3-M polymer

[0070] In this embodiment, the biaxially oriented formable sealable polyester film prepared by sequential biaxial orientation of an extrudate has a B / B / A layer structure film, and the B / B / A layer structure film contains a heat-sealable masterbatch (SH3-M) polymer (which is a blend of PET+isophthalic acid (IPA)) in its innermost layer, so the film exhibits excellent heat-seal strength. The specific composition of the film of this embodiment (referred to as "Film 3") is provided in the following Tables 5 and 6. Figure 2 The structure of the sealable film of this embodiment is described in . The thickness of the B layer is 85% of the total thickness of the polyester film, and the A layer is 15% of the total thickness of the polyester film.

[0071] Table 5: Composition of membrane 3

[0072] Table 6 shows the total weight percentage of the components present relative to Film 3

[0073] Referring to Table 6, Film 3 of the present invention contains 0.063% of silica relative to the weight percentage of the film, 46.75% of PET polymer relative to the weight percentage of the film, 38.18% of modified PET polymer relative to the weight percentage of the film, and 15% of SH3M polymer relative to the weight percentage of the film. Example 4: Method for making biaxially oriented formable polyester film

[0074] Based on different compositions as described in Examples 1, 2 and 3 of the present invention, biaxially oriented formable polyester films with B / B / A layer structures of different thicknesses (e.g., 12μ, 23μ or 36μ) were prepared. The biaxially oriented formable polyester film of the present invention was prepared via a conventional sequential biaxial orientation machine having a single screw main line extrusion and a twin screw sub-extrusion process.

[0075] The detailed method for preparing the biaxially oriented formable polyester films of Examples 1 and 2 of the present invention is provided below: (a) feeding thermoplastic polyethylene terephthalate (PET) and modified PET pellets and silica (filler) having desired properties into a main extrusion line at a temperature of 265° C. to obtain a first mixture; (b) A blend of standard PET pellets and silica as a filler (as in the case of Example 1), or a blend of standard PET pellets, silica as a filler and MBUV polymer (as in the case of Example 2) is fed to a sub-extrusion process at a temperature of 274° C. to obtain a second mixture. Steps (a) and (b) of the extrusion process allow the materials to be melted separately. (c) laminating the first mixture of step (a) and the second mixture of step (b) together in a feed zone to produce a laminated molten structure in an extrusion die. (d) quenching the laminated desired molten structure (e.g. B / B / A PET sheet) of step (c) extruded from the extrusion slot die with the help of a cooling casting drum to produce a thick and amorphous film having a multilayer structure like B / B / A. (e) The amorphous film of step (d) is then subsequently stretched in the machine direction (MD) or in the lengthwise axis of the film using a motorized heater roll set at a temperature range of 86° C. at a stretch ratio of less than 3 to produce a machine direction (MD) oriented film. (f) stretching the longitudinally oriented film of step (e) in the transverse direction (TD) by chain drive system transverse direction orientation (TDO) at a stretching temperature range of 110° C. to 190° C. at a TDO stretching ratio of less than 3 to prepare a biaxially oriented film of the present invention.

[0076] Table 7 discloses exemplary processing parameters for producing the formable flexible PET films of Examples 1 and 2.

[0077] Table 7: Processing parameters for the thermoformable PET films of Examples 1 and 2.

[0078] In addition, the following provides a detailed method for preparing the biaxially oriented formable polyester film of Example 3 of the present invention: a) feeding thermoplastic polyethylene terephthalate (PET) and modified PET pellets and silica (filler) having desired properties into a main extrusion line at a temperature in the range of 255° C. to 278° C. to obtain a first mixture; (b) SH3-polymer (blend of standard PET pellets and IPA polymer) was fed to a sub-extrusion process at a temperature of 274° C. to 275° C. to obtain a second mixture. Steps (a) and (b) of the extrusion process allowed the materials to melt separately. (c) laminating the first mixture of step (a) and the second mixture of step (b) together in a feed zone to produce a laminated molten structure in an extrusion die. (d) quenching the laminated desired molten structure (e.g. B / B / A PET sheet) of step (c) extruded from the extrusion slot die with the help of a cooling casting drum to produce a thick and amorphous film having a multilayer structure like B / B / A. (e) The amorphous film of step (d) is then subsequently stretched in the machine direction (MD) or in the lengthwise axis of the film at a temperature of 86° C. to 88° C. at a stretch ratio of less than 3.1 using a motorized heater roll set to produce a machine direction (MD) oriented film. (f) stretching the longitudinally oriented film of step (e) in a transverse direction (TD) by a chain drive system transverse direction orientation (TDO) at a stretching temperature in the range of 112° C. to 190° C. at a TDO stretching ratio in the range of 3.25% to 3.45% to prepare a biaxially oriented film of the present invention.

[0079] Table 8 discloses exemplary processing parameters for producing the formable sealable flexible PET film of Example 3.

[0080] The films of Examples 1 to 3 can be oriented by any common method, such as roll stretching, long gap stretching, tenter stretching, and tubular stretching. By using any of these methods, sequential biaxial stretching, simultaneous biaxial stretching, uniaxial stretching, or a combination of these can be performed. By the above-mentioned biaxial stretching, stretching in the machine direction and the transverse direction can be performed simultaneously. In addition, stretching can be performed first in one direction and then in the other direction, thereby producing effective biaxial stretching. Stretching of the film can also be performed by preliminarily heating the film at a temperature in the range of 5°C to 80°C (i.e., above its glass transition temperature). Example 5: Properties of Biaxially Oriented Formable Sealable Polyester Films

[0081] The biaxially oriented formable polyester films of Examples 1, 2 and 3 were evaluated based on different parameters such as dart impact, carboxyl end group analysis, intrinsic viscosity, oligomer content, DEG content and thermal characterization such as glass transition temperature.

[0082] The Tg (glass transition temperature) and Tm (melting temperature) of the films of Examples 1 to 3 were studied using a differential scanning calorimeter (DSC-4000 Perkin Elmer). The first exothermic peak was observed in the range of 74°C to 85°C, and the endothermic peak was observed in the temperature range of -260°C. The glass transition temperature of the film was observed in the range of 77°C to 82°C, and the melting temperature was observed in the range of 240°C to 260°C.

[0083] The dart impact strength or toughness of the film is evaluated according to ASTM D1709 by using a dart impact tester. The test uses a single dart configuration and a single drop height while varying the weight of the dart. In this case, the test specimen is securely clamped in the pneumatic ring of the drop tower base. The mounting bracket is adjusted to the appropriate drop height and the dart is inserted into the bracket. The dart is released so that it falls at the center of the test specimen. The dart weight and test results (pass / fail) are recorded. There are two methods (method A and method B) that can be used to record the dart impact strength or toughness. Test method A specifies that a dart with a diameter of 38mm (1.5") falls from 0.66m (26") . Test method B specifies that a dart with a diameter of 51mm (2") falls from 1.5m (60" ). In the present invention, method A is used and a series of 20 to 25 impacts are performed. The results of these impacts are used to calculate the impact failure weight, which is intended to mean the point at which 50% of the test specimens fail under the impact.

[0084] The puncture resistance of the film of the present invention was studied using the standard ASTM F1306-16 for the slow puncture resistance of flexible films and laminates. The puncture resistance of the barrier, in which any sharp object pointing downward will not penetrate the film or laminate, is a crucial part of the quality of thin flexible materials. ASTM F1306 is a specification for the slow puncture resistance of flexible barrier films and laminates. The thin flexible specimen must have a uniform thickness, 0.0025 mm or 0.0001 inch. For this purpose, a universal testing machine with a recording device and a puncture probe is used to perform the test. Finally, the force, energy and elongation to perforate the material are observed.

[0085] Parameters such as carboxyl end group analysis, intrinsic viscosity, oligomer content, DEG content, and thermal characterization such as glass transition temperature and melting temperature values ​​of the compositions are described in Table 9.

[0086] Table 9: Analysis of the membranes of the invention based on different parameters

[0087] In addition, the properties of biaxially oriented formable polyester films of B / B / A multilayer structures with different thicknesses (eg, 12μ, 23μ, and 36μ) were evaluated based on different parameters as described in Table 10 below.

[0088] Table 10: Properties of biaxially oriented formable polyester films

[0089] It can be inferred from Table 10 that the biaxially oriented formable polyester film of the B / B / A multilayer structure having an outer layer B, an intermediate layer B and an inner layer A (the outer layer B and the intermediate layer B contain at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and the inner layer A contains at least one component selected from the following: at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, MBUV polymer, SH3-M polymer and combinations thereof) exhibits the following properties: (a) high dart impact resistance in the range of 200 gf to 850 gf; (b) good puncture resistance, i.e., greater than 4.5 N; (c) high seal strength (0.8 kg / cm2) at a low seal initiation temperature (90°C to 100°C); 2 Up to 1.4kg / cm 2 ); (d) an elongation in the longitudinal direction in the range of 140 to 200% and an elongation in the transverse direction in the range of 130 to 180%.

[0090] In addition, thermoformable films having properties of tensile strength, elongation, dart impact and puncture resistance as well as thermal properties such as seal initiation temperature were compared for all three films of Examples 1 to 3 as shown above. Thus, all three films exhibited both cold forming and hot forming properties.

[0091] In general, it can be inferred from Tables 9 and 10 that the technical properties of the films of the present invention are due to the presence of the modified thermoplastic polyethylene terephthalate (PET) polymer in layer B, and the fillers (e.g. silica) present in the inner layer A, the outer layer B and the intermediate layer B. Example 6: Comparative Example

[0092] This example shows a comparison between the biaxially oriented sealable films of the present invention and conventional films known in the art. Table 11 shows a comparison of oxygen and water transmission rates between conventional films and working films of the present invention. Water vapor transmission rate (WVTR) or moisture vapor transmission rate (MVTR) is the rate at which water vapor passes through a solid material in a specific period of time. OTR-oxygen transmission rate (OTR) is the rate at which oxygen molecules pass through a solid material in a given period of time.

[0093] Table 11: Comparison of oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) between conventional films and working films of the present invention.

[0094] The normal film as mentioned in Table 11 is a film without a barrier coating film which can be prepared by any of the three embodiments of the present invention. The polyvinylidene chloride (PVDC) coated film is an online / offline coated film capable of providing a high oxygen and moisture barrier. In addition, the cold formed film is a film that is stretched against a cavity under cold conditions (i.e., without any heating).

[0095] It should also be noted that the presence of the modified PET polymer is crucial to achieving the film of the present invention that exhibits better functional properties and mechanical properties compared to conventional biaxially oriented films or biaxially oriented polypropylene films / polyethylene films / cast polypropylene films (BOPP / BOPA / PE / CPP) having an A / B / A structure. In addition, the presence of fillers (e.g., silica) in all three layers (i.e., outer layer B and intermediate layer B and inner layer A) is equally important for achieving the biaxially oriented formable film of the present invention. The absence of the modified PET polymer and the filler or the replacement of the modified PET polymer and the filler with any other material will not produce a film with desired functional properties and / or mechanical properties. In particular, a film without fillers may increase the coefficient of friction, and the roll is not easy to open. In addition, in the absence of the modified PET polymer, the structural strength and functional properties of the film are affected.

[0096] For example, the presence of modified PET polymer is important to achieve films with stretchability in the range of 10 mm to 17 mm and exhibiting better structural and functional properties. The effect of the presence of modified PET polymer is demonstrated in Table 12 below.

[0097] Table 12: Effect of the presence of modified PET polymer in the film

[0098] Referring to Table 12, it can be inferred that the presence of modified PET polymer is essential to achieve films (Film 1, Film 2 and Film 3) that exhibit stretchability in the range of 10 mm to 17 mm. The absence of modified PET polymer (as in the case of TF PET polymer without modified PET polymer) resulted in films with a stretchability of less than 10 mm and were therefore considered non-working films. Example 7: Application of the membrane of the present invention

[0099] The biaxially oriented sealable films of the present invention are useful as is or in laminate structures for various packaging, pharmaceutical packaging applications, more specifically, blister packaging such as for capsules, tablets, ideally for deli meats, cuts of meat, poultry or fish, or dry products such as wraps, fresh proteins, frozen foods, sliced ​​cheese packaging, ideally for syringes, tablet packaging, dental instrument boxes, etc. The films of the present invention are also useful for single layer sustainable packaging or to make sustainable recyclable laminates with another polyester film.

[0100] This example utilizes the biaxially oriented sealable film of the present invention to prepare a laminate structure that is further used in laminate packaging materials. Figure 4 Various types of laminate structures comprising the biaxially oriented sealable film of the present invention (as obtained in Example 3) are shown. Figure 4(a) shows a laminate structure comprising a nylon film sandwiched between biaxially oriented polyester films of the present invention. Figure 4 (b) shows an aluminum foil sandwiched between biaxially oriented sealable polyester films of the present invention. Figure 4 (c) shows a single-layer sustainable structure of a single family, and Figure 4 (d) Sustainable mono-family multi-layer laminates. Laminates comprising the films of the present invention exhibit high mechanical strength (e.g., tensile, toughness and elongation), high seal strength, improved barrier properties, better optical properties, balanced shrinkage at elevated temperatures in the longitudinal and machine directions, high temperature dimensional stability, puncture resistance, dart impact strength compared to multilayer films or conventional films (sealable BOPP, PE) or films using PVC, PS, PP, especially PC. Figure 3 Membranes generally known in the art are depicted. Advantages of the present invention:

[0101] The present invention discloses biaxially oriented sealable and non-sealable polyester films of multilayer structure B / B / A, comprising: (a) outer layer B; (b) middle layer B; and (c) inner layer A, wherein outer layer B and middle layer B comprise at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and wherein inner layer A comprises at least one component selected from the group consisting of at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, MBUV polymer, SH3-M polymer and combinations thereof. The present invention also discloses a cost-effective method for preparing biaxially oriented polyester films of multilayer structure B / B / A as included herein.

[0102] The main advantages of the biaxially oriented sealable and non-sealable polyester films of the present invention are: (a) It exhibits good cold formability and hot formability, and also exhibits excellent barrier properties and heat sealability properties after forming. (b) It has a low sealing initiation temperature of 90°C at 0.8 kg / cm 2 Up to 1.4kg / cm 2 Highest sealing strength in the range. (c) It also exhibits excellent optical properties, especially high clarity, and also has good puncture resistance. (d) Its thickness is in the range of 8μ to 75μ. (e) It has good barrier properties, especially to aroma, oxygen and water vapor. (f) The film also has excellent elongation properties in the machine direction (MD) and the transverse direction (TD), which are in the range of 140 to 200 and 130 to 180, respectively. (g) In addition to the above properties, the film also has the following properties: (i) excellent dart impact resistance in the range of 220 gf to 850 gf (meaning the ability to absorb high magnitude impact); (ii) puncture resistance in the range of 6N to 9N; (iii) glass transition temperature (Tg) and melting temperature (Tm) values ​​of 78.2 to 78.7 and 246.9 to 247.8, respectively; (iv) sealing initiation temperature in the range of 90°C to 100°C; and (v) stretchability in the range of 10 mm to 17 mm. (h) The film of the present invention is characterized by having high transparency, having a low filling degree (i.e., low antiblocking agent concentration), wherein the filler facilitates roll unrolling and provides a good coefficient of friction, so that the film of the present invention has good winding and processing qualities. (i) The membrane of the present invention can be recycled without polluting the environment, and the membrane is produced from recycled materials or virgin materials. (j) The film as is or in a laminate structure is particularly useful for pharmaceutical packaging applications, more particularly, blister packaging such as for capsules, tablets, ideally for deli meats, cuts of meat, poultry or fish, or dry products such as wrapping paper, fresh protein, frozen food, sliced ​​cheese packaging, ideally for syringes, tablet packaging, dental instrument boxes, etc. (j) The membrane of the present invention is produced by an economical process.

Claims

1. A biaxially oriented sealable and non-sealable polyester film of multilayer structure B / B / A, comprising: a) outer layer B; b) middle layer B; and c) Inner layer A, wherein the outer layer B and the middle layer B comprise at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer and at least one modified thermoplastic polyethylene terephthalate (PET) polymer, and The inner layer A comprises at least one component selected from the group consisting of at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, an anti-UV masterbatch (MBUV) polymer, a heat-sealable masterbatch (SH3-M) polymer, and combinations thereof.

2. The biaxially oriented sealable and unsealable film according to claim 1, wherein the combined weight percentage of said thermoplastic polyethylene terephthalate (PET) polymer is in the range of 55% to 75% with respect to said film.

3. The biaxially oriented sealable and non-sealable film according to claim 1, wherein the weight percentage of said modified PET polymer is in the range of 30% to 45% with respect to said film.

4. The biaxially oriented sealable and non-sealable film as claimed in claim 1, wherein said filler in a combined weight percentage ranging from 0.03% to 0.08% is selected from silica.

5. The biaxially oriented sealable and non-sealable film as claimed in claim 1, wherein the MBUV polymer comprises PET polymer, UV absorber and antioxidant in a range of 0.5 to 2 weight percent relative to the film.

6. The biaxially oriented sealable and non-sealable film of claim 1, wherein the SH3-M polymer comprises PET polymer and isophthalic acid (IPA) in an amount ranging from 10% to 30% by weight.

7. The biaxially oriented sealable and unsealable film of claim 1, wherein the thermoplastic polyethylene terephthalate (PET) polymer comprises: a) 70% to 80% purified terephthalic acid (PTA); b) 20% to 30% ethylene glycol (EG); and c) 1% to 2% of diethylene glycol (DEG).

8. The biaxially oriented sealable and non-sealable film of claim 1, wherein the modified PET polymer comprises: a) 65% to 85% purified terephthalic acid (PTA); b) 20% to 30% ethylene glycol (EG); and c) 4% to 10% diethylene glycol (DEG).

9. The biaxially oriented sealable and non-sealable film according to any one of claims 1 to 8, wherein the thickness of the film is in the range of 8μ to 75μ.

10. The biaxially oriented sealable and unsealable film according to any one of claims 1 to 8, wherein the film has a percentage of elongation in the longitudinal direction and the transverse direction in the range of 140 to 200 and 130 to 180, respectively, and wherein the film has a low seal initiation temperature in the range of 90°C to 100°C at 0.8 kg / cm 2 Up to 1.4kg / cm 2 The invention relates to a high sealing strength in a range of 200 mm to 800 mm, and wherein the stretchability of the film is in a range of 10 mm to 17 mm.

11. A method for preparing a biaxially oriented sealable and non-sealable film according to any one of claims 1 to 10, the method comprising: a) feeding at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, and at least one modified thermoplastic polyethylene terephthalate (PET) polymer into an extruder at a temperature in the range of 255° C. to 278° C. to obtain a first mixture; b) co-feeding at least one ingredient into a co-extruder at a temperature of 265° C. to 280° C. to obtain a second mixture, wherein the at least one ingredient is selected from at least one filler, at least one thermoplastic polyethylene terephthalate (PET) polymer, MBUV polymer, SH3-M polymer, and combinations thereof; c) laminating the first mixture of step (a) and the second mixture of step (b) in an extrusion die to produce a laminated molten structure; d) extruding the laminated molten structure of step (c) from the extrusion die, and then quenching it to produce a film having a multilayer structure as B / B / A; e) stretching the film of step (d) in the longitudinal direction at a temperature in the range of 80° C. to 95° C. to produce a longitudinally oriented film; as well as f) stretching the longitudinally oriented film of step (e) in a transverse direction at a temperature ranging from 110° C. to 190° C. to prepare a biaxially oriented film.

12. An article comprising the biaxially oriented sealable and non-sealable film according to any one of claims 1 to 10, wherein the article is selected from sustainable recyclable laminate bags, packaging materials for medical packaging applications and blister packaging applications.

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