WO2007027163A2

WO2007027163A2 - Degradable biodegradable polypropylene film

Info

Publication number: WO2007027163A2
Application number: PCT/TR2005/000040
Authority: WO
Inventors: M. Necdet Kileci; Turgut Selbasti; Philippe Lavoisier; Sibel Tilfarligil; Eda Elgin Kilic; Mehmet Hayri Genc; Radu Baciu
Original assignee: Super Film Ambalaj Sanayi Ve Ticaret A. S.
Priority date: 2005-09-01
Filing date: 2005-09-01
Publication date: 2007-03-08
Also published as: TR200801372T2; WO2007027163A3

Abstract

The present invention is related to chemically degradable and/or biodegradable BOPP film that is suitable for all industrial applications such as packaging or non-packaging applications. The film is rendered degradable and/or biodegradable by addition of agents that promote the degradability by combination of heat and UV in a first step and absorption by micro-organism naturally present in soils (agents promoting degradability are metal carboxylate) in a second step. Film is not accumulated in nature due to a non-hazardous degradation process. The mono or multilayer degradable and/or biodegradable BOPP film is characterized in that the layer(s) comprises degradable masterbatch or compound.

Description

DEGRADABLE AND/OR BIODEGRADABLE BIAXIALLY ORIENTED

POLYPROPYLENE FILM

The main objective of the present invention is to provide a chemically degradable and/or biodegradable biaxially oriented film of a polypropylene that is suitable for all industrial applications such as packaging or non-packaging applications. The film is rendered degradable and/or biodegradable by addition of agents that promote the degradability by combination of heat and UV in a first step and absorption by microorganism naturally present in soils (those agents promoting degradability are metal carboxylates) in a second step. Film is not accumulated in nature due to a non-hazardous degradation process.

STATE OF THEART RELATEDWITH THE INVENTION

Synthetic fossil source have been widely used as base of polymeric plastics in all sectors of industry including packaging due to their superior characteristics and shelf life. With the increase of consumption of the synthetic polymer compounds in all sectors of packaging industry including primary packaging in contact with food, secondary over wrapping packaging and transport bags, the amount of waste of plastics has also incredibly increased.

It has become a major civil concern how the waste of plastics should be managed. Waste either goes to landfill, to compost or to incineration. Still landfill is the biggest way of waste disposal.

Incineration causes problem due to high heat generation in furnace and risk of emission of toxic substances, but landfill also causes problem of accumulation because they are degrading in very long period of time, also with wind blowing material can migrate to unpolluted areas. It is a major concern for our children to take care of environment.

Therefore all industry has to look forward how to manage the shelf life of polymeric materials such as polyolefins and make them becoming degradable and biodegradable in a predetermined period of time and without limited greenhouse effect as well.

The plastic packaging materials such as polyethylene, polypropylene, polyester have been widely used as a packaging material. Since polypropylene remains semi permanently in nature like other polyolefins, it cannot degrade when you disposed it to a landfill.

The prior art has attempted to make films biodegradable using some resins such as polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxybutyrate (PHB), polycaprolactone (PCL), polyethylene succinate (PES), polycaprolactone/polybutylene succinate mixtures or copolymers (PCL/PBS), polyethylene terephthalate/polyethylene succinate copolymers (PET/PES), polyhydroxybutyrate/polyhydroxyvalerate copolymers (PHB/PHV), polybutylene succinate/polybutylene adipate mixtures or copolymers (PBS/PBA) and polybutylene terephthalate/polybutylene adipate copolymers (PBT/PBA). The wastes of plasties must be recycled up to certain number due to some environmental and governmental regulations for example EC (European Community).

To increase the use and acceptance of biodegradable materials, cost and performance problems should be overcome. In this present invention these two difficulties overcome by using limited amount of degradable additive. Degradable and/or biodegradable biaxially oriented polypropylene which is developed in this present invention is much more economical, regarding the degradable and biodegradable materials used in the market. Polypropylene is one of the most commonly used polymeric base material for non-biodegradable films used in the various kinds of packaging or non packaging applications, for example flower packaging and labeling which are low cost without degradable products.

The degradable additive used in this present invention does not interfere with the additives such as slip, antiblock, antistatic, etc. used for the production of the regular BOPP. Hence, the performance of the biodegradable biaxially oriented polypropylene described in this present invention regarding the quality is the same as the regular biaxially oriented polypropylene product.

Some attempts have been made to achieve degradable plastic materials in the prior art. During the search performed on the biodegradable plastic materials, several patent publications were found. US 2004/0241359 describes a material which is PLA and a biodegradable base resin such as polyester mixture that can be processed into relatively thin films. A biodegradable film formable into biodegradable bags includes the blended product of polylactic acid and a suitable biodegradable polymeric resin such as polyester with starch. The blended product includes from about 5% to about 50% by weight polylactic acid. In preferred embodiments of the present invention, the polylactic acid-containing biodegradable films may be formed into a bag. Preferably, the biodegradable films of this invention are formed through a blown film process.

Even with those improvements, biaxially oriented polylactic acid-based film and blends have other disadvantages such as their high density 1.25 versus 0.9 for polypropylene, crispy noise when handled in the converting machines, high cost of raw material and green housing incidence (high percentage of acid gas emission and CO2 emission when degrading).

US patent application 2005/0008815 discloses biodegradable biaxially oriented polylactic acid-based film suitable for packaging films; such film which is a mixture of crystalline polylactic acid 95 to 60 parts by weigth with 5 to 40 parts of amorphous polylactic acid has tear strength in width direction of 10 to 200 mN. The film disclosed in this patent is suitable for bags and packaging films for various windows, particularly films for outlook window envelopes. The film is biodegradable and, as films for outlook window envelopes, is superior in the coating adaptability for an antistatic agent, a lubricant and an antiblocking agent or the like and in the high-speed cutting property. The major disadvantages of biaxially oriented polylactic acid films are their tensile strength in machine direction (MD) which are 15,950 psi while biaxially oriented Polypropylene is 27,550 psi. Such material has poor flexibility and therefore are not easy to use for wrapping applications. This invention discloses a biaxially oriented film of a polylactic acid resin comprising not less than 50% by weight of a polylactic acid resin.

In U.S. Pat. No 2005/0059796, it has been described that biodegradable aliphatic thermoplastic polyesters useful for the production of several types of articles such as films, sheets, nets, expanded molded products, and the like, and process for their production. This invention refers biodegradable polyesters of the diacid/diol type comprising at least one at least trifunctional compound in order to obtain articles with enhanced permeability, low gels content and an improved transparency.

U.S. Pat. No 2005/0151296 discloses a lactic acid-based resin composition that comprises a lactic acid-based resin (component (A)), and an ethylene-unsaturated carboxylic acid copolymer (component (B)) and/or an ethylene-unsaturated carboxylic acid copolymer ionomer (component (C)). The lactic acid-based resin composition has good physical properties in melt and can be efficiently formed into films and laminates through casting or extrusion lamination. The paper laminates obtained through extrusion lamination with the resin composition have good moisture barrier property, and have the advantages of good antibacterial ability, good biodegradability and low combustion heat. And the moldings obtained from the resin composition of the invention have a characteristic which is excellent in impact strength. Further, the films and sheets formed of the resin composition have good low-temperature heat-sealability and hot-tack sealability, and the resin composition well serves as a sealant. The resin composition is favorable to various materials in a broad range, for example, for wrapping and packaging materials for foods, drinks, electronic appliances, medicines and cosmetics, for materials for use in agriculture, civil engineering and construction and for materials for compost, etc. US 2005/0163944 describes a biodegradable film having two biodegradable resin layers and a biodegradable moisture barrier layer interposed between the resin layers. This invention also accomplishes the above object by providing a biodegradable container having a biodegradable container body coated with the biodegradable film of the present invention. This invention also provides biodegradable moistureproof paper having biodegradable paper coated with the biodegradable film of the present invention. This invention also provides a biodegradable container formed of the biodegradable moisture proof paper of the present invention.

In U.S. Pat. No 2002/0160201 , it has been described that a flexible biodegradable film enough for practical use, more precisely, to provide a biodegradable film which keeps itself flexible in severe condition, for example, even at high temperatures. Another object of the invention is to provide a softened biodegradable film which is substantially free from appearance change and morphology change such as transparency reduction, even when stored or used for a long period of time at high temperatures. To attain these objects, this invention provides a biodegradable oriented film of a plasticizer-containing biodegradable resin, of which the both surfaces are coated with at least one thin layer and of which the loop stiffness change (ΔR) after heat treatment at 13O⁰C for 30 minutes is at most 20%. The film is stretched at least monoaxially. The thin layer formed on the both surfaces of the biodegradable film of the invention is preferably so designed that it is effective for preventing the plasticizer in the film from scattering away and/or bleeding out. The biodegradable oriented film of the invention is useful, for example, for wrapping films. This coating makes of course some additional costs to the film and this thin layer does not degrade even with this thin layers.

US patent 5,470,526 issued November 28th 1995, to Minnesota Mining and ^' Manufacturing discloses degradable multilayered structures which are compostable. The composition includes thermoplastic polymer with a transition metal salt selected from cobalt, manganese, copper, cerium, vanadium and iron and a fatty acid. Composition will oxidatively degrade to an embrittled state in specific environment conditions. The film disclosed in this patent is not oriented film. Only under appropriate, low temperature conditions (i.e. below 60⁰C), can multilayered structures be uniaxially, biaxially or multiaxially oriented to further enhances their physical properties without loosing the mesophase form of polypropylene, mesopolymer blends, or mesocopolymers. Its degradability is 14 days under 49 ⁰C. The degradability of another type of the film of this invention is 14 days under 60 ⁰C. The film produced according to this patent can not be used mainly in general packaging including food or flower packaging, adhesive tape films and labelling, because; • In the BOPP film production the temperature can be between 120 to 250 ⁰C in different steps of the process,

• In printing, coating or wrapping conditions of the produced films, the temperature is above 100 ⁰C, US patent 5,321,065 issued on June 14th 1994 describes a degradable plastic film incorporating in ethylene copolymers some lignin in the form of powder, the film in 15 to 25 microns can be doubly decomposable by adding photoactive and oxidizing agents. Lignin is a polymeric vegetable material made of methoxyiated and hydroxylated cores and it is a by-product obtained in the manufacture of paper pulp, for this reason it is a renewable product. The drawback of this technology, is that if the lignin, included in a proportion of around 3 to 25% degrades itself the ethylene copolymer does not degrade and anyhow require photoactive agent.

US patent 5,384,183 issued on January 24th, 1995 is also related to degradable film consisting essentially of photodegradable polyethylene sheet with cerium salt of C16-₂0 fatty acid and with titanium dioxide, this titanium dioxide, normally considered as an opacifying agent is useful to control the rate of polymer degradation.

US patent 5,416,133 dated May 16, 1995, is directed to chemically degradable polyolefin film, mainly melt blown polyolefin, especially polyethylene, the incorporation of a metal carboxylate with 25 to 60% filler such as talc are made chemically and thermally degradable. Incorporation of filler is intended to reduce the price of the melt blown film.

The document U.S. Pat. No 2004/0076778 discloses a biodegradable bag for packing a food capable of storing a food such as a snack food which is required to have an oxygen barrier property and a water vapor barrier property, which can be produced at a high speed by a bag making and packaging machine, which can be degraded by naturally occurring microorganisms in soil or water finally to a non-hazardous degradation product, which can be biorecycled, and which is not accumulated in nature. This invention is directed to a biodegradable bag for packing a food, which comprises a laminated film obtainable by laminating in the following order; a sealant layer comprising a biodegradable polymer; a barrier layer having an oxygen barrier property and a water vapor barrier property; and a barrier layer-supporting substrate layer comprising a biodegradable polymer, said laminated film being heat-sealed in order for the sealant layer to be inside.

In U.S. Pat. No. 2004/0241359 and U.S. Pat. No 2005/0008815, the materials are made biodegradable by the addition of different percentages of polylactic acid by weight. These films are PLA based films and their densities are much higher when compared with the product of the present invention. In U.S. Pat. No 2005/0059796, biodegradable thermoplastic polyester for the production of films, sheets etc. is described. This invention is related only with the polyester.

In U.S. Pat. No 2005/0151296, a composition of lactic acid -based resin, ethylene carboxylic acid copolymer and ethylene- unsaturated carboxylic acid copolymer ionomer is disclosed. The product described in this patent has some disadvantages such as high density like first and second patent mentioned above.

The most important property of the invention described in US 2005/0163944 is to provide biodegradable moisture proof paper having biodegradable paper coated with the biodegradable film of the invention. This invention relates with a coated material requiring further processing unlike the product of this present invention.

The object of the invention described in U.S. Pat. No 2002/0160201 is to provide a softened biodegradable film which is substantially free from appearance change and morphology change such as transparency reduction, even when stored or used for a long period of time at high temperatures. This invention provides a biodegradable oriented film of a plasticizer-containing biodegradable resin, of which the both surfaces are coated with at least one thin layer to attain these objects. This invention is also related with a coated material requiring further processing unlike the product of this present invention.

U.S. Pat. No 2004/0076778 is directed to a biodegradable bag for packing a food, which comprises a laminated film obtainable by laminating in the following order; a sealant layer comprising a biodegradable polymer; a barrier layer having an oxygen barrier property and a water vapor barrier property; and a barrier layer-supporting substrate layer comprising a biodegradable polymer, said laminated film being heat-sealed in order for the sealant layer to be inside. This invention is related only with the biodegradable bags for food packaging.

The major disadvantages of PLA based materials when compared to degradable and/or biodegradable BOPP films developed according to this invention are hereinunder. a) They are produced from non food corns, b) They consume fertilizers and pesticides, c) They have higher density than polypropylene, d) They degrade with 60% more acid gas emission and 40% more CO₂ emission, e) They have higher cost when compared with non degradable materials and other biodegradable materials. f) They have lower tensile strength in both machine and transverse directions, g) They have lower puncture resistance, h) They have low moisture resistance. i) It is difficult to control degradability. The present invention solves these disadvantages.

ADVANTAGES OF THIS PRESENT INVENTION

Advantages of this present invention are as follows; b) Product of this present invention is made degradable and/or biodegradable with the addition of limited amount of degradable additives. c) No process parameters change is necessary to make degradable and/or biodegradable product. Therefore, the process parameters of the regular biaxially oriented polypropylene film can be used for the production of biodegradable film described in this present invention. d) No need to modify the production line of the regular BOPP for the production of the material described in this present invention. e) The additive used in this present invention does not interfere with the additives such as slip, antiblock, antistatic, etc. used for the production of the regular BOPP. Consequently, physical properties such as haze, gloss, etc. or mechanical properties such as tensile strength, elongation at break, shrinkage, etc. of the degradable and biodegradable film of this invention are almost the same as the regular BOPP film. f) The recycling material coming from edges are recycled directly in the film (up to 25%) without any effect on the film. g) Density of the degradable and/or biodegradable product formed in this present invention is lower compared with the PLA based materials and naturally degradable cellulose. h) Biodegradable product described in this invention unlike the PLA based materials is not noisy and crispy material when handled. i) Biodegradable product described in this invention has wide thickness range from very thin films such as 5 μm to thicker films such as 100 μm.

EXPLANATION OF THE INVENTION The film according to the present invention is preferably produced by using the following process and has the characteristics below.

The general definition of the process for the production of the biodegradable BOPP film is as follows: (a) Coextruding the melted materials of individual layer(s) of the film through a die.

(b) Biaxially stretching the film at a machine and a transverse direction.

(c) Cooling down the biaxially stretched film.

(d) Treating the film (corona, flame, plasma ... etc).

(e) Winding the film up. A method for producing a biaxially oriented film of the present invention is known as a flat tenter process (sequential or simultaneous stretching), but may also be made on a tubular method such as bubble or double bubble process technology as well.

On the flat tenter process as sequential stretching, the process starts from the gravimetric dosing of each component in each of the layers that will constitute the film. The film can also produced by simultaneous stretching process.

The active additive that promotes degradability, which is metal carboxylate, is mixed into every layer(s) of the film. The layers constitute polypropylene homopolymer, terpolymer or copolymer of polypropylene according to the final use, and additionally the additives such as slip, antistatic, antiblock (synthetic or polymeric), coloring (organic or inorganic) and cavitating agents (organic or inorganic) or alike in masterbatch or compound form which are necessary for specific end use properties.

The prepared raw material is fed in each extruder which are either single screw or twin screw extruder and melt mixed preferably at a temperature below 27O⁰C, where the active additive is not degrading, The melt is then going through a multimanifold die with manual or automatic thickness control system, the melt is then going onto a chill roll where the water bath and roll cooling temperature are adjusted to control the crystallinity.

Non oriented crystallized film is then stretched in the machine direction (MD) in a ratio from 4 to 7, more preferably in a range from 5 to 6, the film is preheated to allow MD stretching and heat set at the outlet part of the MD section before entering the TD

(transverse direction) stretching unit. Transverse direction (TD) stretching is in a ratio from 7-10, more preferably 8-9. Operating temperatures are between 120-140 ⁰C for preheating, 80 - 130 ⁰C in the stretching zone and 130-140 ⁰C on the heat setting zone of MDO (machine direction orienter) section

MD oriented film goes into the transverse direction (TD) orienting section, the film is conveyed in an oven by clips, it is preheated, drawed in the TD direction and heat stabilized before leaving the TDO (transverse direction orienter) section.

Temperature in the oven are related to thermal exchange within the film, speed and final film thickness; typical temperatures are in a range of 160-180⁰C in the preheating zone , 150-160⁰C in stretching zone and 160-170⁰C in heat setting zone. Biaxially oriented film is then wound in the final width with as complementary steps, going through corona or flame or plasma treatment units and also in an edge cutting section where sides of TD stretch film are cut and going to recycling unit.

The recycling material coming from edges are recycled directly in the film without any effect on the film. When a tubular method is chosen, a heat treatment method wherein a film is heated by external hot air and the like, while kept in tensed stage by controlling and maintaining internal pressure of the bubble by sealing internal air.

The thickness of the film of the present invention is preferably in the range from 5 to 100 μm, more preferably in the range from 7 to 50 μm. In particular, the thickness of the film is preferably in the range from 15 to 50 μm to provide mechanical and optical properties for different industrial applications.

If non oriented monolayer PP film is produced according to this invention then the thickness can be up to 200 μm.

The primary objective of this present invention is to replace the non-degradable BOPP film with the degradable and/or biodegradable counterpart for packaging applications such as fresh vegetable and fruit packaging, food or any good packaging, or any non packaging applications such as flower wrapping, labelling, adhesive tape applications and different industrial applications ...etc.

The second aim of this present invention is not to change the physical or mechanical properties of standard non-degradable BOPP to meet the requirements of the specified applications.

To achieve these objectives, some active agents are added to each layer of the material of this present invention. By using these active agents added to each layer, the shelf life of the film is controlled. The material of this present invention having monolayer or multilayer structure has the same mechanical and optical properties as normal unfilled polypropylene film before going to landfill. To produce a multilayered degradable and/or biodegradable biaxially oriented polypropylene film, some active agents have been added to each layer. In degradation, large molecules are broken into smaller molecules or fragments. Normally, oxygen is incorporated into these molecular fragments. Typically, strong, tough plastic films become weak and brittle as a result of oxidative degradation. Heat or exposure to UV light initiates the process of degradation and mechanical stress enhances this process.

On the other hand, biodegradation is the process by which microorganisms (microbes such as bacteria, fungi or algae) convert materials into biomass, carbon dioxide and water. Biomass is a general term used to refer to the cells of the microorganisms that are using the material as a carbon source to grow on. Biodegradable products can be classified into 5 categories;

1- Biopolymers coming from plants (starch, cellulose, lignin,)

2- Biopolymers produced by chemical polymerisation, joining renewable raw materials with industrial polymerisation process (PLA)

3- Biopolymers produced by micro-organism genetically modified (PHA, PHV, PHB) 4- Synthetic polymers

5- Fossil source of polymers such as PE, PP, PET with additives that promote their biodegradability.

This present invention belongs to 5^th category of degradable polymers.

The process parameters of the regular biaxially oriented polypropylene film are used to have the product of this present invention therefore no need to change any process conditions used in the production of regular BOPP film.

It is important that degradable and/or biodegradable property must not be revealed until the shelf life of the product completed. Accordingly, the heat applied to the product in melting or extrusion stages of the production must not activate the degradation process. A flat tenter process technology with draw ratio in machine direction from 4 to 7 and in the transverse direction from 7 to 10 is used to orient the multilayer polypropylene film in both axis. The multilayered biaxially oriented polypropylene film described in this present invention undergoes two step degradation process after completion of its shelf life or when it goes to landfill. In first step of the degradation, heat or exposure to UV light initiates the process of degradation by oxidation and mechanical stress enhances this process. In the second step, the product of this present invention which is fragmented in much shorter oxidized molecules is converted to biomass, carbon dioxide and water by microorganisms accumulated in nature.

The density of the product developed in this present invention is lower when compared with PLA based biodegradable material. Consequently, the yield (m²/kg) of the product developed in this present invention is higher. Multilayer biaxially oriented polypropylene film of this present invention shows no crispy noise effect that can be seen in PLA based biodegradable material.

The multilayer film of the present invention can be produced by the conventional methods such as sequential stretching, simultaneous stretching used in the production of biaxially stretched polyolefins. Since stretching ratios are independently adjustable in sequential stretching, that one is preferable method for the production of the multilayer film of the present invention among the others.

The characteristics of the raw materials used in the formulation of the multilayer film of the present invention are as follows; Polypropylene homopolymer having a melting point of 150 ⁰C or above, melt flow rate between about 2.0 to 4.0 is preferred to be used.

Antiblocking agent from the group of inorganic additives such as silicon dioxide, calcium carbonate, aluminum silicate, magnesium silicate, calcium phosphate and the like and/or organic polymers for example polyamides, polyesters and the like. Preferred antiblocking agent is aluminum silicate.

Terpolymer of ethylene, propylene and butylene is preferred to be used in this present invention. Such material brings, sealability of film and is mostly used on the skin layers of multilayered film.

Slip/antistatic masterbatch having a melt flow rate close to that of homopolymer is preferable.

Degradable masterbatch or compound used in this present invention can have as active agents inbodied in polyolefin resins; • transition metal salt selected from cobalt, manganese, copper, cerium, vanadium, aluminum, antimony, barium, cadmium, lead, silver, sodium, zinc, iron and alike, and a fatty ester providing unsaturated species, and free acid, or

• salts having organic and inorganic ligands, suitable inorganic ligands includes chlorides, nitrates, sulfates and the like,

The preferred active agent of degradable masterbatch or compound used in the present invention are inorganic ligands such as octanoates, acetates, stearates, oleates, naphtenates, linoleates, tallates and the like.

Polyolefins are carbon chains containing carbon hydrogen and small amounts of oxygen. These polymers react with oxygen in the air. Since this oxidation reaction is too slow, they cannot be accepted as degradable materials. To accelerate this oxidation reaction, the degradable masterbatch or compounds as catalysts are added in this present invention.

In processing of polymers, hydroperoxides are formed due to oxidation. Free radicals are produced due to the decomposition of hydroperoxides with heat, light or metal catalysts. After that, these free radicals undergo chain reaction to produce oxidation products. Acceleration of oxidation occurs because of the new oxidation reactions of produced free radicals. As a result of these oxidation reactions, carbon chain of the polymer is broken and its chain length is reduced. The final result of all these reactions is that the chain scission of polymer and transition of material from tough state to brittle state. At this state, polymeric material is ready for the attack of microorganisms (microbes such as bacteria, fungi or algae) which convert materials into biomass, carbon dioxide and water.

PREFERRED APPLICATION OF THE INVENTION The main feature of the present invention is to add degradable masterbatch or compound into the layer(s) of the mono or multilayer BOPP film to make it degradable and/or biodegradable.

The degradable masterbatch or compound is between about 0.5 % to about 10 % by weight of the layer, more preferably from about 1 % to about 3 % by weight of the layer.

The mono or multilayered biaxially oriented polypropylene film according to this present invention is produced under the same process parameters as regular unfilled (without degradable masterbatch or compound) biaxially oriented polypropylene film. The mono or multilayered biaxially oriented polypropylene film according to this present invention is extruded before orientation under the same extrusion temperature parameters as regular unfilled film; extrusion and melt temperature does not start activation of film degradation. The mono or multilayered biaxially oriented polypropylene film according to this present invention has lower density than PLA based biodegradable material.

The mono or multilayered biaxially oriented polypropylene film according to this present invention has no crispy noise effect in comparison with PLA based biodegradable material. In the application of this present invention, the degradable masterbatch or compound can be added some of the the layer(s) of the multilayer BOPP film to make it degradable and/or biodegradable.

The recycling material coming from edges are recycled directly in the film of present invention (up to 25%) without any effect on the film. The mono or multilayered biaxially oriented polypropylene film according to this present invention can be in different color, cavitated, metallized or coated according to the application.

EXAMPLES OF THE APPLICATION OF THE PRESENT INVENTION

Some of the examples for the compositional characteristics of the multilayer film of the present invention are as follows;

EXAMPLE 1

An example of the present invention for heat sealable degradable and/or biodegradable BOPP film is below.

Layer 1 (First skin layer) contains between about 92 % and about 99 % by weight of terpolymer, more preferably from about 94 % to 98 % by weight, between about 0.5 % to about 4 % by weight of antiblocking agent, more preferably from about 1 % to about 3 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight.

Layer 2 (First intermediate layer) contains between about 96 % and about 99.5 % by weight of homopolymer, more preferably from about 97 % to 99 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight. Layer 3 (Main layer) contains between about 92 % and about 99 % by weight of homopolymer, more preferably from about 94 % to 98 % by weight, between about 0.5 % to about 4 % by weight of slip/antistatic masterbatch, more preferably from about 1 % to about 2 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight.

Layer 4 (Second intermediate layer) contains between about 96 % and about 99.5 % by weight of homopolymer, more preferably from about 97 % to 99 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight. Layer 4 can be totally identical with layer 2 or slight modifications can be made.

Layer 5 (Second skin layer) contains between about 96 % and about 99.5 % by weight of terpolymer, more preferably from about 97 % to 99 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight.

The heat sealable degradable and/or biodegradable BOPP film given in the Example 1 is used especially for fresh vegetable and fruit packaging.

The test results for quality parameters comparing Example 1 (having degradable masterbatch) with standard film (without degradable masterbatch) are given in the following table.

EXAMPLE 2

An example of the present invention for non heat sealable degradable and/or biodegradable BOPP film is below.

Layer 1 (First skin layer) contains between about 92 % and about 99 % by weight of homopolymer, more preferably from about 94 % to 98 % by weight, between about 0.5 % to about 4 % by weight of antiblocking agent, more preferably from about 1 % to about 3 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight.

Layer 2 (First intermediate layer) contains between about 96 % and about 99.5 % by weight of homopolymer, more preferably from about 97 % to 99 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight.

Layer 3 (Main layer) contains between about 96 % and about 99.5 % by weight of homopolymer, more preferably from about 97 % to 99 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight.

Layer 5 (Second skin layer) contains between about 92 % and about 99 % by weight of homopolymer, more preferably from about 94 % to 98 % by weight, between about 0.5 % to about 6 % by weight of antiblocking agent, more preferably from about 1 % to about 5 % by weight, between about 0.5 % to about 4 % by weight of non-migratory antiblock masterbatch, more preferably from about 1 % to about 3 % by weight between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight. Layer 5 can be totally identical with layer 1 or slight modifications can be made. The non heat sealable degradable and/or biodegradable BOPP film given in the

Example 2 is used especially for flower packaging.

The test results for quality parameters comparing Example 2 (having degradable masterbatch) with standard film (without degradable masterbatch) are given in the following table.

EXAMPLE 3

Another example of the present invention for non heat sealable degradable and/or biodegradable BOPP film is below.

Layer 1 (First skin layer) contains between about 88 % and about 98.5 % by weight of homopolymer, more preferably from about 91 % to 97 % by weight, between about 0.5 % to about 4 % by weight of antiblocking agent, more preferably from about 1 % to about 3 % by weight, between about 0.5 % to about 4 % by weight of antistatic masterbatch, more preferably from about 1 % to about 3 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch, more preferably from about 1 % to about 3 % by weight.

Layer 5 (Second skin layer) contains between about 86 % and about 98.5 % by weight of homopolymer, more preferably from about 89 % to 97 % by weight, between about 0.5 % to about 4 % by weight of antiblocking agent, more preferably from about 1 % to about 3 % by weight, between about 0.5 % to about 4 % by weight of antistatic masterbatch, more preferably from about 1 % to about 3 % by weight more preferably from about 1 % to about 3 % by weight, between about 0.5 % to about 4 % by weight of degradable masterbatch.

The non heat sealable degradable and/or biodegradable BOPP film given in the Example 3 is used especially for labeling.

The test results for quality parameters comparing Example 3 (having degradable masterbatch) with standard film (without degradable masterbatch) are given in the following table.

The examples of the films according to this present invention can be created with many different combinations and different number of layers.

Degradability tests have been performed to compare Examples 1 , 2 and 3 (having degradable masterbatch) with standard films (without degradable masterbatch or compound) to see the brittleness.

Totally brittleness is the state at which the films of the present invention has no or little tear or tensile strength and crumble when folded. This state shows that the polymeric film of the present invention has become totally brittle and this property was tested by hand.

A4 size samples of the films with and without degradable masterbatch have been put under UV lamp in the lab for testing photo degradation. During the UV lamp tests, the films having degradable masterbatch according to the examples 1, 2 and 3 have become totally brittle in 10 days. But in the non degradable counterpart of the examples no change has occurred.

The same size samples of the films with and without degradable masterbatch have been put into the standard lab type oven at 70 ⁰C for testing thermal degradation.

During the thermal degradation tests, the films having degradable masterbatch according the examples 1, 2 and 3 have become totally brittle in 35 days. But in the non degradable counterpart of the examples no change has occurred.

If the films having degradable masterbatch are not exposed to sun and stays in normal temperature then no change occurs.

The present invention can be applied directly to cast polypropylene film process without orientation by adding the degradable masterbatch or compound into the layers with the similar ratios stated above.

Claims

1- A mono or multilayer degradable and/or biodegradable biaxialiy oriented polypropylene film characterized in that the layer(s) comprises degradable masterbatch or compound. 2- A mono or multilayer degradable and/or biodegradable biaxialiy oriented polypropylene film according to Claim 1 and characterized in that the degradable masterbatch or compound has transition metal salt selected from cobalt, manganese, copper, cerium, vanadium, aluminum, antimony, barium, cadmium, lead, silver, sodium, zinc, iron and alike, and a fatty ester providing unsaturated species, and free acid as active agent.

3- A mono or multilayer degradable and/or biodegradable biaxialiy oriented polypropylene film according to Claim 1 and characterized in that the degradable masterbatch or compound is salts having organic and inorganic ligands, suitable inorganic ligands includes chlorides, nitrates, sulfates and the like. 4- A mono or multilayer degradable and/or biodegradable biaxialiy oriented polypropylene film according to Claim 1 and characterized in that the degradable masterbatch or compound is inorganic ligands such as octanoates, acetates, stearates, oleates, naphtenates, linoleates, tallates and the like.

5- A mono or multilayer degradable and/or biodegradable biaxialiy oriented polypropylene film according to any of the preceding Claims and characterized in that the degradable masterbatch or compound is between about 0.5 % to about 10 % by weight of the layer.

6- A mono or multilayer degradable and/or biodegradable biaxialiy oriented polypropylene film according to any of the preceding Claims and characterized in that the degradable masterbatch or compound is more preferably from about 1 % to about

3 % by weight of the layer.

7- A mono or multilayer degradable and/or biodegradable biaxialiy oriented polypropylene film according to any of the preceding Claims and characterized in that it is produced under the same process parameters as regular unfilled (without degradable masterbatch) biaxialiy oriented polypropylene film.

8- A mono or multilayer degradable and/or biodegradable biaxialiy oriented polypropylene film according to any of the Claims 1 - 7 and characterized in that the process of production is flat tenter process. 9- A mono or multilayer degradable and/or biodegradable biaxially oriented polypropylene film according to any of the Claims 1 - 8 and characterized in that the tenter process of production is simultaneous or sequential stretching.

10- A mono or multilayer degradable and/or biodegradable biaxially oriented polypropylene film according to any of the Claims 1 -7 and characterized in that the process of production is bubble process.

11- A mono or multilayer degradable and/or biodegradable biaxially oriented polypropylene film according to any of the preceding Claims and characterized in that it is extruded before orientation under the same extrusion temperature parameters as regular unfilled film and extrusion and melt temperature does not start activation of film degradation.

12- A mono or multilayer degradable and/or biodegradable biaxially oriented polypropylene film according to any of the preceding Claims and characterized in that it has lower density than PLA based biodegradable material. 13- A mono or multilayer degradable and/or biodegradable biaxially oriented polypropylene film according to any of the preceding Claims and characterized in that it has no crispy noise effect in comparison with PLA based biodegradable material.

14- A multilayer degradable and/or biodegradable biaxially oriented polypropylene film according to any of the preceding Claims and characterized in that the degradable masterbatch or compound is added some of the the layer(s).

15- A multilayer degradable and/or biodegradable biaxially oriented polypropylene film according to any of the preceding Claims and characterized in that the recycling material coming from edges are recycled directly in the film (up to 25%) without any effect on the film. 16- A mono or multilayer degradable and/or biodegradable polypropylene film produced by cast process without orientation characterized in that the layer(s) comprises degradable masterbatch or compound.

17- A mono or multilayer degradable and/or biodegradable polypropylene film produced by cast process without orientation according to Claim 16 and characterized in that the degradable masterbatch or compound has transition metal salt selected from cobalt, manganese, copper, cerium, vanadium, aluminum, antimony, barium, cadmium, lead, silver, sodium, zinc, iron and alike, and a fatty ester providing unsaturated species, and free acid as active agent. 18- A mono or multilayer degradable and/or biodegradable polypropylene film produced by cast process without orientation according to Claim 16 and characterized in that the degradable masterbatch or compound is salts having organic and inorganic ligands, suitable inorganic ligands includes chlorides, nitrates, sulfates and the like. 19- A mono or multilayer degradable and/or biodegradable polypropylene film produced by cast process without orientation according to Claim 16 and characterized in that the degradable masterbatch or compound is inorganic ligands such as octanoates, acetates, stearates, oleates, naphtenates, linoleates, tallates and the like.

20- A mono or multilayer degradable and/or biodegradable polypropylene film produced by cast process without orientation according to any of the Claims 16 - 19 and characterized in that the degradable masterbatch or compound is between about 0.5 % to about 10 % by weight of the layer.

21 -A mono or multilayer degradable and/or biodegradable polypropylene film produced by cast process without orientation according to Claim 16 - 20 and characterized in that the degradable masterbatch or compound is more preferably from about 1 % to about

3 % by weight of the layer.

22- A mono or multilayer degradable and/or biodegradable polypropylene film produced by cast process without orientation according to any of the preceding Claims and characterized in that the film is in different color, cavitated, metallized or coated according to the application.