SELBASTI, Turgut (2. Organize Sanayi Bolgesi, Haci Sani Konukoglu BulvariNo.1 Baspinar, GAZIANTEP, 27120, TR)
GENC, Mehmet Hayri (2. Organize Sanayi Bolgesi, Haci Sani Konukoglu BulvariNo:1 Baspinar, GAZIANTEP, 27120, TR)
KILIC, Eda Elgin (2. Organize Sanayi Bolgesi, Haci Sani Konukoglu BulvariNo:1 Baspinar, GAZIANTEP, 27120, TR)
TILFARLIGIL, Sibel (2. Organize Sanayi Bolgesi, Haci Sani Konukoglu BulvariNo:1 Baspinar, GAZIANTEP, 27120, TR)
KILECI, Mehmet Necdet (2. Organize Sanayi Bolgesi, Haci Sani Konukoglu BulvariNo.1 Baspinar, GAZIANTEP, 27120, TR)
SELBASTI, Turgut (2. Organize Sanayi Bolgesi, Haci Sani Konukoglu BulvariNo.1 Baspinar, GAZIANTEP, 27120, TR)
GENC, Mehmet Hayri (2. Organize Sanayi Bolgesi, Haci Sani Konukoglu BulvariNo:1 Baspinar, GAZIANTEP, 27120, TR)
KILIC, Eda Elgin (2. Organize Sanayi Bolgesi, Haci Sani Konukoglu BulvariNo:1 Baspinar, GAZIANTEP, 27120, TR)
TILFARLIGIL, Sibel (2. Organize Sanayi Bolgesi, Haci Sani Konukoglu BulvariNo:1 Baspinar, GAZIANTEP, 27120, TR)
CLAIMS
1- Non-oriented barrier multilayer (2 or more layers) polymeric films for in-mould applications comprising; a) top layer which contacts the die/mould and comprising; • between 80 - 100 % by weight of copolymer, or
• between 80 - 100 % by weight of terpolymer, or
• between 80 - 100 % by weight of homopolymer, b) intermediate layers or bottom layer which contacts the product to be labelled being in different combinations selected from; • a layer or layers containing about 80 % to 100 % by weight of homopolymer.
• a layer or layers containing about 80 % to 100 % by weight of copolymer or terpolymer,
• a layer or layers containing about 50 % to 100 % by weight of anhydride grafted polyolefin as an adhesive (tie) layer. • a layer or layers layer containing about 80 % to 100 % ethylene vinyl alcohol
(EVOH) as a polymeric barrier material.
• a layer or layers containing about 80 % to 100 % polyamide or polyamide copolymers as a polymeric barrier material,
• a layer or layers containing about 50 % to 100 % by weight matte masterbatch,
• a layer or layers containing about 50 % to 100 % by weight HDPE (high density polyethylene) c) top layer or intermediate layers or bottom layer can contain antiblocking, antistatic, slip, UV stabilizer and/or coloring agent. Top layer or bottom layer can contain non migratory slip besides of these abovementioned additives.
2- Non-oriented barrier multilayer polymeric films for in-mould applications according to Claim 1 and characterized in that the terpolymer is preferably terpolymer of polypropylene, polyethylene and polybutylene.
3- Non-oriented barrier multilayer polymeric films for in-mould applications according to Claim 1 and characterized in that the copolymer is preferably copolymer of polypropylene and polyethylene. 4- Non-oriented barrier multilayer polymeric films for in-mould applications according to any of the preceding claims and characterized in that the film is metallized for barrier properties and/or visual appealing.
5- Non-oriented barrier multilayer polymeric films for in-mould applications according to any of the preceding claims and characterized in that the film has the thickness ranging from about 20 to about 250 micron, preferably from about 50 to about 150 micron, more preferably from about 70 to about 100 micron.
6- Non-oriented barrier multilayer polymeric films for in-mould applications according to any of the preceding claims and characterized in that the film has the density between about 0.7 g/cm 3 and 1.5 g/cm 3 , preferably between about 0.8 g/cm 3 and 1.0 g/cm 3 .
7- Non-oriented barrier multilayer polymeric films for in-mould applications according to any of the preceding claims and characterized in that the film is produced using the conventional techniques of producing non-oriented polymeric films which are known as cast or blown film processing in industry. 8- Non-oriented barrier multilayer polymeric films for in-mould according to any of the preceding claims and characterized in that the film is transparent or coloured or matte.
9- Non-oriented barrier multilayer polymeric films for in-mould according to any of the preceding claims and characterized in that one or both sides of the film is treated using flame, corona, chemical, plasma treatment techniques. 10- Non-oriented barrier multilayer polymeric films for in-mould applications according to any of the preceding claims and characterized in that one or both sides of the film is chemically coated.
11- Non-oriented barrier multilayer polymeric films for in-mould applications according to any of the preceding claims and characterized in that in-moulding process is injection moulding, blow moulding or thermoforming. |
NON-ORIENTED BARRIER POLYMERIC FILMS FOR IN-MOULD (IML)
APPLICATIONS
This invention is related with multi layer (2 or more layers) non-oriented labelling material (film) to be used in in-mould labelling(IML) processes. This material uses different polymer compositions for different applications required by in-mould labelling (IML) processes. The polymeric materials used in the conventional production of non-oriented film are mainly polypropylene, polyethylene, polybutylene, polyamide, MXD-6, ethylene vinyl alcohol, polystyrene and homopolymer, terpolymer or copolymer of these materials mentioned above. Barrier polymeric film described in this present invention is non-oriented with improved processability and barrier properties using barrier polymeric materials such as, polyamide (PA), MXD-6, ethylene vinyl alcohol (EVOH) can be used for the production of the film.
STATE OF THE ART RELATED WITH THE INVENTION
Non oriented polymeric films are available for different applications such as food or non-food packaging, labelling, lamination with other kinds of polymers or packaging materials. Polymeric films can be non-oriented (cast), mono-oriented or both sided oriented(balanced or biaxially) depending on the properties of the final film, processing on packaging machine and properties needed for the goods to be packed.
These polymeric materials started to be used as label films such as wrap around labels, shrink labels, patch labelling, self-adhesive labels, etc. Mainly biaxially oriented polypropylene (BOPP) films with different characteristics are preferred depending upon lower density, high yield, easy processability, excellent optical properties, excellent mechanical properties, etc. Main preference is the cavitated white opaque BOPP films due to much lower density (g/cm 3 ) and higher yield (m 2 /kg) properties. For years, various containers and lids produced by injection processes have been labelled offline by using an adhesive to adhere the label to the container and the lid. This process had many disadvantages regarding the adhesion of the label to the container which end up non-uniform labelling and low speed application. One of the main disadvantages mostly revealed when the label required have different shapes such as round, oval, cross, square, etc.
After the development of in mould labelling technology, BOPP films were the main candidate as a label material due to above mentioned properties and additionally they have better insulation capability in which hold static charge on surfaces. Due to these properties, BOPP films are started to be used for a label material with the help of developed technologies in IML applications.
But along all these good properties BOPP films showed one of their disadvantages as being curled before or after printing process related with biaxially orientation process which ends up with inadequate dimensional stability. It is experienced that larger the label dimensions, higher the dimensional instability and worse curling effect. The basic process of in mould labelling is as follows:
1. The die/mould that will form the plastic product (container or lid) is opened to allow the label to be inserted and held in place either by a vacuum or by static.
2. The label is generally placed inside the die/mould by the use of a robotic arm.
3. The die/mould is closed automatically. 4. The plastic resin that is used to form the product are heated and injected into the die/mould.
5. The label is fused onto the outer surface of product as the product is forming.
6. The die/mould is opened, formed and labelled finished product drops or taken out.
7. The process begins again. Within this process non printed surface of the label is contacted with the molten polymer which constitutes the container or lid. Molten polymer is mainly polystyrene, polypropylene, polyvinylchloride, polyester, etc. and all these polymers are melted using the temperatures above 200 0 C. Even though, the label is cooled down in the mold; still higher heat of molten polymer affect the dimensional stability of the label and gives undesirable forming defects of the final product.
It is seen that non-oriented structures which have better dimensional stability, could overcome this problem which is affected by biaxially or balanced oriented labelling materials.
Six patent publications were found during the survey performed on the non- oriented barrier polymeric films for in-mould application developed with this invention as prior art.
EP0575631 relates to a recyclable label for in-mould labelling (IML) for reusable plastic containers and a process for the production thereof. The IML label has only polyethylene or polypropylene as plastic component and is embedded in the container wall by in-mould labelling during container production. Preferably the IML label consists essentially of a single plastic grade and corresponds to the container material. Apart from polyethylene or polypropylene, it has a filler and a colorant as additional components. The IML label is formed as a single-layer film.
US2004030050 provides isotactic polypropylene compositions suitable for cast film applications, cast polypropylene films made therefrom, and processes for forming such films. The novel polypropylene films are formed from film resins having a melt flow ratio of from 6-15 dg/min, with a narrow molecular weight distribution, narrow composition distribution, low level of solvent extractables, and increased film clarity (i.e., decreased haze %) compared to prior art Ziegler-Natta polypropylene film resins. The polypropylene films can be cast from an extruded polypropylene polymer, the extruded isotactic polypropylene polymer being formed by polymerization with a fluorided silica supported catalyst. US2005260427 is related with a biaxially-oriented opaque polypropylene multilayer film, made from a base layer, at least one first intermediate layer arranged thereon and a first surface layer arranged on the first intermediate layer. The first intermediate layer has essentially no vacuoles. The first surface layer comprises at least 80 wt.% of a propylene/ethylene copolymer with an ethylene content of 1.2 to <2.8 wt.% and a propylene content of 97.2- 98.8 wt.%, a melting point in the range 145 to 160 DEG C and a fusion enthalpy of 80 to 110 J/g. The base layer comprises vacuoles and has a density in the range 0.35 to 0.6 g/cm 3 . The invention further relates to the use of said film for the in-mould labelling of containers made from thermoplastic polymers.
In the patents mentioned above, no explanation is provided about non-oriented barrier polymeric films for in-mould applications
WO2005040270 describes a mono or a multi-layered cast film having at least one layer of a two component polymer compositions. More particularly, the invention relates to labels made from such cast film. The first component of the polymer composition is a high crystallinity polypropylene. The second component is a hetero-phasic polypropylene copolymer. The invention also relates to processes for making such cast films and labels thereof. The cast films according to the invention have characteristics suitable for label application such as low curl, stiffness, good die cutting, good thermal stability, printability and antistatic properties. In patent no WO2005040270, high crystallinity polypropylene and heterophasic polypropylene copolymer are mentioned to give characteristics for label application such as low curl, stiffness, good die cutting, good thermal stability, printability and antistatic properties.
US 6,911 ,244 B discloses a film structure and a method manufacturing the same.
More specifically the film structure may include a barrier material made from EVOH, nylon or thermally sensitive barrier material encapsulated by a first adhesive material. The barrier material and first adhesive material form a barrier layer and a first adhesive layers
when co-extruded. The barrier layer and the first set of adhesive layers may be co- extruded at the same or a similar temperature to form a first extrudate. The extrudate may be encapsulated by or otherwise co-extruded with a second adhesive material to form a second extrudate at a higher temperature than the first extrudate that then may be formed into a flat sheet via a die. The first set of adhesive layers protect the barrier layer from high temperatures and long residence times related to the coextrusion/lamination process that may degrade the barrier layer. In addition, acid terpolymer consisting of ethylene/methyl acrylate/acrylic acid adheres a barrier material of EVOH to outer layers of the film structure. In this publication an encapsulated barrier film is disclosed. The film is not for in-mould purposes. Additionally it has a sandwich structure. The sandwich structure gives the effects (sealability, stiffness, strength, heat resistance, durability and/or printability to the structure) to the film.
EP 0 387 883 A1 discloses a method for in mould applications. In this publication it is disclosed that some different base films such as polypropylene, polyethylene, polyester, polyvinylchioride are used. The details of the base films and properties have not been disclosed. The base film has a membrane layer for bonding to be welded by the heat of moulded article at time of the in-mould moulding. This membrane component are selected from heat weldable adhesive wax, a membrane of main component from copolymer of ethylene vinyl acetate, or any membrane of main component from polyvinyl acetate polymer, polyvinyl alcoholic polymer, polyacryl acid esteric polymer, vinyl chloride polymer, polyethylene polymer, polyurethane polymer or polyester polymer.
AIMS IN DEVELOPMENT OF THE PRESENT INVENTION
In developing the present invention; non-oriented barrier polymeric films for in- mould applications; • having a thickness ranging from about 20 to about 250 micron,
• having a density between about 0,7 g/cm 3 and 1 ,5 g/cm 3 ,
• using the conventional technique of producing non-oriented polymeric films,
• having 7 layers with different layer constructions depending on the desired properties for final application • having different barrier properties depending upon the final use.
• being transparent, coloured or matte.
• being metallized to increase barrier property and/or visual appealing, is aimed.
BRIEF DESCRIPTION OF THE FIGURES
Non-oriented barrier polymeric films for in-mould applications developed in this invention has been shown in the attached figure 1 (Cross sectional view of the film).
The parts (layers) of this invention shown in the figure are numberred and the definition of the numbers are given below.
1 - Layer 1 (top layer)
2- Layer 2
3- Layer 3
4- Layer 4 5- Layer 5
6- Layer 6
7- Layer 7 (bottom layer)
DESCRIPTION OF THE INVENTION The labelling materials for in mould labelling such as injection moulding, blow moulding and thermoforming applications described in this present invention are non- oriented barrier polymeric films. In this present invention, multi layer (2 or more layers) barrier polymeric films, can have polypropylene, polyethylene, polybutylene, polyamide, MXD-6, ethylene vinyl alcohol, polystyrene homopolymers and terpolymer or copolymer of these materials and also including organic or inorganic materials to obtain one or more properties such as slip, antistatic, antiblock, matte, color effect etc., to the final product, are described.
The layers of the non-oriented barrier polymeric films for in-mould applications developed in the present invention are grouped in 3 groups. • Group 1 consists layer 1 (top layer) (1),
• Group 2 consists layers 2 - 6 (intermediate layers) (2, 3, 4, 5, 6),
• Group 3 consists layer 7 (bottom layer) (7).
Top layer (1) is the layer which contacts the die/mould. Top layer (1) contains;
• Between 80 - 100 % by weight of copolymer, or • Between 80 - 100 % by weight of terpolymer, or
• Between 80 - 100 % by weight of homopolymer,
The terpolymer in the top layer (1) is preferably terpolymer of polypropylene, polyethylene and polybutylene. The copolymer in the top layer (1) is preferably copolymer of polypropylene and polyethylene.
The layers 2 - 6 (intermediate layers) (2, 3, 4, 5, 6) or bottom layer (7) can be in different combinations of the following;
• A layer or layers containing about 80 % to 100 % by weight of homopolymer.
• A layer or layers containing about 80 % to 100 % by weight of copolymer or terpolymer,
• A layer or layers containing about 50 % to 100 % by weight of anhydride grafted polyolefin as an adhesive (tie) layer.
• A layer or layers containing about 80 % to 100 % by weight of ethylene vinyl alcohol (EVOH) as a polymeric barrier material.
• A layer or layers containing about 80 % to 100 % polyamide or polyamide copolymers as a polymeric barrier material. • A layer or layers containing about 50 % to 100 % by weight of matte masterbatch.
• A layer or layers containing about 50 % to 100 % by weight of HDPE (high density )
Top layer or intermediate layers or bottom layer can contain antiblocking, antistatic, slip, UV stabilizer and/or coloring agent. The intermediate layers (2, 3, 4, 5, 6) are selected from the abovementioned layers. Top layer or bottom layer can contain non migratory slip besides of these abovementioned additives.
Non migratory slip in the top layer (1) or bottom layer (7) can be PMMA (polymethyl methacrylate), polyamide, polyester and their derivatives. Non migratory is spherical particles to give consistent slip property onto surface as well as nonblocking effect.
The film can also be metallized for barrier properties and/or visual appealing. One or both side can be treated by means of corona, flame, plasma and alike and/or chemically coated with such as acrylic, PVdC (polyvinyldichloride), PVOH (polyvinylhydroxide), PEN (polyethylenenaphthalate), PU (polyurethane), copolyester, etc. Preferred antiblocking agents are inorganic additives such as silicium dioxide, calcium carbonate, aluminium silicate, magnesium silicate, calcium phosphate and the like and/or organic polymers such as polyamides, polyesters and the like. Preference is given to silicium dioxide.
By applying the different layer combinations; the non-oriented barrier polymeric films for in-mould labelling applications, having;
• Matte,
• Transparent, • Colored,
• Metallized can be produced.
The non-oriented barrier polymeric films for in-mould labelling applications can be produced as 2, 3, 4, 5, 6, 7 or layers. Non-oriented barrier polymeric films of the present invention are defined as, the films; a) having a thickness ranging from about 20 to about 250 micron, preferably from about 50 to about 150 micron, more preferably from about 70 to about 100 micron, b) having a density between about 0.7 g/cm 3 and 1.5 g/cm 3 , preferably between about 0.8 g/cm 3 and 1.0 g/cm 3 , c) are produced using the conventional technique of producing non-oriented polymeric films which are also known as cast or blown film processing in industry, d) having 2 or more layers with different layer constructions depending on the desired properties and final application of the films, e) having different barrier properties depending upon the final use, f) can be transparent, coloured or matte. g) can be metallized to increase barrier property or visual appealing,
The method for producing a non-oriented barrier polymeric films of the present invention is known as a cast process. The general definition of the process for the production of the non-oriented polymeric films are as follows; a) Feeding the prepared raw materials to each extruder having single or twin screws, b) Coextruding the melted materials of individual layers of the film through a die, c) Cooling down the non-oriented film, d) Treating the film (corona, flame, plasma, chemical), e) Winding the film up,
The raw materials are fed in each extruder which are either single screw or twin screw to have different layers depending upon the structure of the materials. The layers can constitute polypropylene, polyethylene, polybutylene, polyamide, MXD-6, ethylene vinyl alcohol, polystyrene homopolymers and terpolymer or copolymer of these materials and also including organic or inorganic materials to obtain one or more properties, and additionally the additives such as slip, antistatic, antiblock (synthetic or polymeric), coloring (organic or inorganic) and alike in masterbatch or compound form which are necessary for spesific end use properties. The materials are mixed and melted at a temperature preferably below 28O 0 C. The melt is then going onto chill roll where the roll cooling temperature are adjusted to control the crystallinity, then crystallized cast film going through automatic thickness control system.
Non-oriented film is then wound in the final width with as complementary steps, going through corona, flame or plasma treatment units and also in an edge cutting section where sides of final film are cut and going to recycling unit. The recycling material coming from edges are recycled directly in the suitable layers of the film without any effect on the film.
Slip agent can be selected from the group of oleamide, erucamide, secondary amides.
Antistatic agent can be selected from the group of fatty acid esters, ethoxylated alkylamines, diethanolamides, ethoxylated alcohol. Glycerol monostearate as fatty acid ester is preferrable against the others due to its compliance with food contact regulations and its fast migrating behaviour.
Antiblocking agent can be selected from the group of synthetic silica, natural silica, talc(magnesium hydrosilicate), zeolites, limestone. The barrier polymeric films produced with above mentioned process has advantages to be used as IML applications in injection moulding, blow mould and thermoforming applications to solve present problems. a) More elasticity in the mould compared with biaxially or balanced oriented polymeric films such as BOPP films. b) No curling property during handling c) No orange peel effect due to non-orientation d) Better processability for containers as well as for lids e) No distortion of the walls of the container due to non-orientation
f) Better barrier property related with the suitable polymeric materials for specific applications such as for food packaging and products containing fat, e.g. butter, margarine, meat pate, fresh cheese, fish, deli, etc., which needs mainly oxygen barrier. g) Low temperature stability compared with oriented polymeric films.
Non-oriented barrier polymeric films described in this present invention also have same characteristics such as printability for reel and/or sheet fed UV-Offset, roto gravure and or flexo, flatness, die cutting, slip, static chargeability, etc., besides solving the above mentioned problems. One of the main advantages in this present invention is to have a seven layer film which enable to produce such films; a) having the same polymeric materials on both sides of main layer to give balanced structures to provide better uniformity of final film to eliminate curling effect. b) having different polymeric materials which will provide barrier property of the final film for specific end uses. c) using two or more barrier polymeric materials which are not compatible together with the use of a tie (adhesive) layer between the layers
EXAMPLES OF THE PRESENT INVENTION Some of the examples for the compositional characteristics of the multilayer non- oriented barrier polymeric films of the present invention are as follows;
EXAMPLE 1
An example of the present invention is barrier matte non-oriented film for in-mould application is as follows;
Layer 1 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of terpolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antiblocking agent.
Layer 2 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of polypropylene homopolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antistatic agent.
Layer 3 contains 100 % anhydride grafted polyolefin as a tie layer.
Layer 4 contains 100 % ethylene vinyl alcohol (EVOH) as a polymeric barrier material.
Layer 5 contains 100 % anhydride grafted polyolefin as a tie layer. Layer 6 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of polypropylene homopolymer, between about 2 % to about 10 % by weight preferably from about 4 % to about 8 % by weight of antistatic agent.
Layer 7 contains 100 % matte masterbatch.
EXAMPLE 2
Another example of the present invention is a barrier white colored, one side matte non-oriented film for in-mould application is as follows;
Layer 1 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of terpolymer, between about 2 % to about 10 % by weight and more preferably from about 4 % to about 8 % by weight of antiblocking agent.
Layer 2 contains between about 55 % to about 83 % by weight and preferably from about 62 % to about 76 % by weight of polypropylene homopolymer, between about
15 % to about 35 % by weight and preferably from about 20 % to about 30 % by weight of white masterbatch, between about 2 % to about 10 % by weight and preferably from about
4 % to about 8 % by weight of antistatic masterbatch.
Layer 3 contains 100 % anhydride grafted polyolefin as a tie layer.
Layer 4 contains 100 % ethylene vinyl alcohol (EVOH) as a polymeric barrier material. Layer 5 contains 100 % anhydride grafted polyolefin as a tie layer.
Layer 6 contains between about 55 % to about 83 % by weight and preferably from about 62 % to about 76 % by weight of polypropylene homopolymer, between about
15 % to about 35 % by weight and preferably from about 20 % to about 30 % by weight of white masterbatch, between about 2 % to about 10 % by weight preferably from about 4 % to about 8 % by weight of antistatic masterbatch.
Layer 7 contains 100 % matte masterbatch.
EXAMPLE 3
Third example of the present invention is transparent barrier non-oriented film for in-mould application is as follows;
Layer 1 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of terpolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antiblocking agent.
Layer 2 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of polypropylene homopolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antistatic agent.
Layer 3 contains 100 % anhydride grafted polyolefin as a tie layer.
Layer 4 contains 100 % ethylene vinyl alcohol (EVOH) as a polymeric barrier material.
Layer 5 contains 100 % anhydride grafted polyolefin as a tie layer. Layer 6 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of polypropylene homopolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antistatic agent.
Layer 7 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of terpolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antiblocking agent.
COMPARATIVE EXAMPLE 1
A comparative example of the present invention is matte non-oriented polymeric polypropylene film for in-mould application is as follows;
Layer 1 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of terpolymer, between about 2 % to about 10 % by weight preferably from about 4 % to about 8 % by weight of antiblocking agent.
Layer 2 to Layer 6 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of polypropylene homopolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antistatic agent
Layer 7 contains 100 % matte masterbatch.
COMPARATIVE EXAMPLE 2
Another comparative example of the present invention is one white colored, one side matte non-oriented polymeric polypropylene film for in-mould application is as follows;
Layer 1 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of terpolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antiblocking agent. Layer 2 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of polypropylene homopolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antistatic agent.
Layer 3 contains between about 80 % to about 90 % by weight and preferably from about 85 % to about 95 % by weight of polypropylene homopolymer, between about 10 % to about 20 % by weight and preferably from about 5 % to about 15 % by weight of white masterbatch.
Layer 4 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of polypropylene homopolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antistatic agent.
Layer 5 contains between about 80 % to about 90 % by weight and preferably from about 85 % to about 95 % by weight of polypropylene homopolymer, between about 10 % to about 20 % by weight and preferably from about 5 % to about 15 % by weight of white masterbatch.
Layer 6 contains between about 90 % to about 98 % by weight and preferably from about 92 % to about 96 % by weight of polypropylene homopolymer, between about 2 % to about 10 % by weight and preferably from about 4 % to about 8 % by weight of antistatic agent. Layer 7 contains 100 % matte masterbatch.
TEST RESULTS
The three examples and two comparative examples described above have been tested. The test results are given in the following Table.
As it can be seen from these results, examples of this present invention showed 5 much better barrier properties compared with the standard films according to the comparative examples.