Polyolefin composition for non-oriented films with improved oxygen barrier properties

Abstract

The present invention relates to a polyolefin composition suitable for the preparation of a non-oriented film having improved oxygen barrier properties, and to such a non-oriented film. The polyolefin composition comprises a propylene homopolymer or copolymer, a hydrocarbon resin and optionally a nucleating agent. The present invention also relates to the use of a hydrocarbon resin in a non-oriented film comprising a propylene homopolymer or copolymer for improving the oxygen barrier properties of said non-oriented film. The present invention allows the use of polypropylene based non-oriented films, such as cast films (CPP), for the packaging of sensitive food products.

Description

TECHNICAL FIELD

[0001] The present invention relates to a polyolefin composition suitable for preparing a non-oriented film having improved oxygen barrier properties, and to such a non-oriented film. The polyolefin composition comprises a propylene homopolymer or copolymer, a hydrocarbon resin and optionally a nucleating agent. The present invention further relates to the use of a hydrocarbon resin in a non-oriented film comprising a propylene homopolymer or copolymer for improving the oxygen barrier properties of said non-oriented film. BACKGROUND

[0002] It is known in the art to widely use films based on polyolefin compositions for various applications. One of these applications is food packaging. One of the main tasks in this respect is to provide films having sufficient oxygen barrier properties. The sufficiency in this respect depends on the type of food to be packaged, the required shelf life and environmental conditions, such as temperature and oxygen partial pressure. In particular, for sensitive food, increasing the oxygen barrier properties is always a task.

[0003] Films for food packaging are usually transparent, or more generally, should have good optical properties to provide an attractive appearance. This includes low haze, high transparency and high gloss in a uniform manner.

[0004] Furthermore, the mechanical properties should be sufficient to make the film easy to handle, while avoiding unintentional damage to the film. Finally, the easy processable film should be suitable for industrial applications.

[0005] In the case of transparent films, if the thickness of the film is reduced, the optical properties will be improved, i.e. the haze is reduced and the transparency is higher, however, the mechanical properties and the oxygen barrier properties are generally reduced as a consequence.

[0006] Generally, transparent films for food packaging having good oxygen barrier properties are biaxially oriented polypropylene (BOPP) films, or even better biaxially oriented polyamide (BOPA) films and biaxially oriented polyethylene terephthalate (BOPET) films.

[0007] To date, no solution can bring polypropylene-based non-oriented films (such as cast films (CPP)) close to these films. Typical approaches to improve the oxygen barrier properties are considered, but they do not provide an equivalent solution. The addition of quenching nucleating agents has only a limited effect and increases the haze. Oxygen scavengers have only a limited effect because the presence of moisture is required in the package in order to be effective. Nanoparticles are difficult to disperse on an industrial scale and are problematic in terms of food contact. Blends with barrier polymers are also not promising because these polymers are generally polar and therefore difficult to disperse in polypropylene, even with the use of coupling agents. This translates into unacceptable optical properties if transparency is required. Finally, the addition of fillers with a specific shape can slow down the transfer of oxygen through the film due to the high specific surface they provide. However, the dispersion of these fillers is difficult because, in order to maintain the specific shape, it is generally necessary to add at the end of the extruder screw. In addition, the optical properties are generally deteriorated. SUMMARY

[0008] It is therefore an object of the present invention to provide a polyolefin composition suitable for use in polypropylene-based non-oriented films with improved oxygen barrier properties.

[0009] The present invention is based on the finding that this object can be achieved by providing a polyolefin composition comprising a hydrocarbon resin and optionally a nucleating agent.

[0010] Thus, in a first aspect, the present invention relates to a polyolefin composition comprising:

[0011] - (A) a propylene homopolymer or copolymer having a MFR2 of 0.5 to 80 g / 10 min measured according to ISO 1133, and

[0012] - (B) a hydrocarbon resin product comprising a hydrocarbon resin, wherein the hydrocarbon resin has a weight average molecular weight of 500 to 5,000 g / mol, preferably 700 to 3,000 g / mol.

[0013] In a second aspect, the present invention relates to a polyolefin composition comprising:

[0014] - (A) a propylene homopolymer or copolymer having a MFR2 of 0.5 to 80 g / 10 min measured according to ISO 1133, and

[0015] - (B) a hydrocarbon resin product comprising a hydrocarbon resin, wherein the hydrocarbon resin has a melt viscosity of 80 to 400 mPa.s at 200°C, preferably 100 to 400 mPa.s at 200°C, more preferably 150 to 400 mPa.s at 200°C.

[0016] In a third aspect, the present application also relates to a polyolefin composition comprising:

[0017] - (A) a propylene homopolymer or copolymer having a MFR2 of 0.5 - 80 g / 10 min measured according to ISO 1133, and

[0018] - (B) a hydrocarbon resin product comprising a hydrocarbon resin, wherein the hydrocarbon resin has a softening point of 200°C or less, preferably 180°C or less, more preferably 170°C or less (ASTM-E28).

[0019] The softening point of the hydrocarbon resin of the hydrocarbon resin product is preferably 70°C or higher.

[0020] The hydrocarbon resin of the hydrocarbon resin product (B) according to the first or third aspect of the present application described above preferably has a melt viscosity at 200°C of 80 - 400 mPa.s, 100 - 400 mPa.s, more preferably 150 - 400 mPa.s at 200°C.

[0021] The hydrocarbon resin of the hydrocarbon resin product (B) according to the first or second aspect of the present application described above preferably has a softening point of 200°C or less, more preferably 180°C or less, still more preferably 170°C or less. The softening point will typically be 70°C or above.

[0022] The hydrocarbon resin of the hydrocarbon resin product (B) according to the second or third aspect of the present application described above preferably has a weight average molecular weight of 500 - 5,000 g / mol, preferably 700 - 3,000 g / mol.

[0023] The hydrocarbon resin of the hydrocarbon resin product (B) according to the first aspect of the present application described above preferably has a melt viscosity at 200°C of 80 - 400 mPa.s, 100 - 400 mPa.s, more preferably 150 - 400 mPa.s at 200°C, and has a softening point of 200°C or less, more preferably 180°C or less, still more preferably 170°C or less. The softening point will typically be 70°C or above.

[0024] The following disclosure of preferred embodiments and definitions is valid for any one of the first, second and third aspects of the polyolefin composition of the present application described above. DETAILED DESCRIPTION

[0025] In this text, the "polyolefin composition" is also referred to as "polymer composition" in short.

[0026] In this text, the propylene homopolymer or copolymer (A) and the hydrocarbon resin product (B) are also referred to as component (A) and component (B), respectively.

[0027] As will be explained in more detail with reference to the following examples, the combination of component (A) and component (B) of the present application is capable of significantly improving the oxygen barrier properties of the non-oriented film compared to a non-oriented film not comprising component (B). This improved oxygen barrier property is seen by a significant reduction of the oxygen transmission rate (OTR) of the non-oriented film. The OTR is preferably reduced by at least 30% and can be reduced up to about 50%.

[0028] Preferably, the stiffness of the non-oriented film is also enhanced and can even be doubled. This improved stiffness is reflected by the corresponding tensile properties. Thus, the present application provides a non-oriented film, such as a cast film, with properties close to those of an oriented film, such as a BOPP.

[0029] Preferably, the combination of component (A) and component (B) of the present application is capable of providing a non-oriented film with very good optical properties, such as one, more or all, preferably all, of reduced haze, increased gloss and transparency. The presence of component (B) also enables running a process for producing a non-oriented film with a higher cooling temperature without deteriorating the optical properties, such as producing a cast film with a relatively higher chill roll temperature. Preferably, due to the higher cooling temperature option, the presence of component (B) enables the addition of a nucleating agent, thereby further improving the oxygen barrier properties of the non-oriented film, i.e. further reducing the oxygen transmission rate, by the effect of the nucleating agent on the crystallinity. Finally, the presence of component (B) preferably reduces the melt pressure in the film making process, which facilitates the production process of an industrially viable film in terms of processability, which means that a higher throughput option is available (if desired).

[0030] Thus, the polyolefin composition according to the present application can further comprise a nucleating agent (C), also referred to as component (C) herein.

[0031] Component (A): propylene homopolymer or copolymer (A)

[0032] In the following, component (A), i.e. propylene homopolymer or copolymer (A), is further explained.

[0033] The melt flow rate (MFR2) of component (A), i.e. propylene homopolymer or copolymer (A), is preferably in the range of 0.5 to 20 g / 10 min, more preferably in the range of 1 to 20 g / 10 min.

[0034] In case component (A) is a propylene copolymer, one or more, e.g. two, three or more, comonomers can be present. Thus, the term copolymer as used herein includes terpolymers as well as copolymers based on more than three different polymerizable monomers.

[0035] The comonomer of the propylene copolymer as component (A) is preferably selected from the group consisting of ethylene, C4-C8-alpha olefins and mixtures thereof, suitably from the group consisting of ethylene, butene, hexene and / or octene.

[0036] The comonomer content in the propylene copolymer as component (A) is preferably less than 7.5 mol% based on the propylene copolymer. The comonomer content will typically be at least 0.5 mol% based on the propylene copolymer.

[0037] A particularly preferred component (A) is a propylene homopolymer.

[0038] The expression homopolymer as used in the present invention relates to a polypropylene consisting essentially of, i.e. at least 99.5 wt%, more preferably at least 99.8 wt% of propylene units. In a preferred embodiment, only propylene units are detectable in the propylene homopolymer. The comonomer content can be determined by means of13C NMR spectroscopy. 13 The comonomer content is measured by means of13C NMR spectroscopy.

[0039] In this respect, it is particularly preferred that the propylene homopolymer as component (A) has a pentad isotacticity (mmmm) equal to or greater than 98.0 mol%. Independently or additionally, it is particularly preferred that the propylene homopolymer has a melting temperature (Tm) of at least 150.0 °C. Independently or additionally, it is particularly preferred that the propylene homopolymer has a xylene cold soluble (XCS) content equal to or lower than 1.5 wt%. According to one particularly preferred embodiment, the propylene homopolymer has all of the above three particularly preferred properties. m ) of at least 150.0 °C. Independently or additionally, it is particularly preferred that the propylene homopolymer has a xylene cold soluble (XCS) content equal to or lower than 1.5 wt%. According to one particularly preferred embodiment, the propylene homopolymer has all of the above three particularly preferred properties.

[0040] It is further preferred that the propylene homopolymer as component (A) has an even higher pentad isotacticity (mmmm), i.e. equal to or greater than 98.5 mol%, more preferably equal to or greater than 99.0 mol%. The pentad isotacticity (mmmm) will need to be equal to or lower than 100.0 mol%, and will typically be equal to or lower than 99.8 mol%.

[0041] It is further preferred that the component (A), preferably the propylene homopolymer, has a melting temperature of at least 153.0 °C, more preferably of at least 163.0 °C. The upper limit value for the melting temperature will typically be equal to or lower than 175 °C.

[0042] It is further preferred that the component (A), preferably the propylene homopolymer, has a flexural modulus of at least 1,400 MPa, more preferably of at least 2,000 MPa. The flexural modulus will typically be equal to or lower than 4,000 MPa, preferably in the range of 2,000 to 3,000 MPa.

[0043] It is further preferred that component (A), preferably a propylene homopolymer, has a Vicat softening temperature of at least 140 °C, more preferably at least 145 °C, still more preferably at least 150 °C. The Vicat softening temperature is typically equal to or below 170 °C.

[0044] The amount of component (A), i.e. the propylene homo- or copolymer, is preferably 60 to 99 wt.-%, more preferably 60 to 98 wt.-% and still more preferably 70 to 95 wt.-%, 70 to 93 wt.-% or 70 to 90 wt.-%, based on the total polyolefin composition (100 wt.-%).

[0045] Component (A), i.e. the propylene homo- or copolymer (A), can be a commercially available product or can be produced, for example, by a conventional polymerization process and process conditions, using, for example, a conventional catalyst system, such as a Ziegler-Natta catalyst or a single-site catalyst, including a metallocene catalyst, preferably a Ziegler-Natta catalyst, which has the well-known meaning and is well described in the literature.

[0046] Component (A), i.e. the propylene homo- or copolymer (A), of the present application can be prepared, for example, in a conventional manner in a continuous multi-stage process. The process preferably comprises at least two polymerization stages. A preferred multi-stage process is a “loop-gas phase” process, such as the process developed by Borealis, referred to as BORSTAR® technology, e.g. as described in patent literature such as EP 0 887 379, WO 92 / 12182, WO 2004 / 000899, WO 2004 / 111095, WO 99 / 24478, WO 99 / 24479 or WO 00 / 68315. Technology).

[0047] Component (B): hydrocarbon resin product comprising a hydrocarbon resin

[0048] In the following, component (B) is further explained.

[0049] With regard to the weight average molecular weight, the melt viscosity and the softening point of the hydrocarbon resin of component (B), i.e. the hydrocarbon resin product, reference is made to the information already provided above, respectively.

[0050] The term “resin” as defined for component (B), i.e. the hydrocarbon resin product, has the meaning well known in the art.

[0051] The hydrocarbon resin of component (B), i.e. the hydrocarbon resin product, of the polyolefin composition of the present application is preferably amorphous.

[0052] The hydrocarbon resin of component (B), i.e. the hydrocarbon resin product, preferably further has the feature of a glass transition temperature of 0 to 100 °C, more preferably of 40 to 90 °C.

[0053] The hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) can be obtained from natural sources (i.e. from distillates of natural substances, such as distillates or extracts of inorganic materials or organic materials (such as plants)) or can be obtained by synthesis.

[0054] According to one embodiment, the hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) comprises an aliphatic resin, an aromatic resin, an aliphatic / aromatic copolymer resin or mixtures thereof. The aliphatic resin comprises a linear aliphatic resin (which can be unbranched or branched) and a cycloaliphatic resin.

[0055] In one embodiment of the present application, the aliphatic resin of component (B) (i.e. the hydrocarbon resin product) comprises a C5 monomer-based resin and / or a dicyclopentadiene monomer-based resin. Thus, the C5 monomer-based resin is a polymerisation product of C5 monomers, and the dicyclopentadiene monomer-based resin is a polymerisation product of dicyclopentadiene monomers. Preferably, in this embodiment, the C5 monomer-based resin and / or the dicyclopentadiene monomer-based resin is the major component (greater than 50 wt%, preferably greater than 60 wt%, preferably greater than 80 wt% of the C5 monomer-based resin and / or the dicyclopentadiene monomer-based resin based on component (B)).

[0056] The C5 monomers can include, for example, 1-pentene, isoprene, cyclopentadiene or 1,3-pentadiene monomers, or any combination thereof.

[0057] In another embodiment of the present application, the aliphatic resin of component (B) (i.e. the hydrocarbon resin product) comprises a mixture of alkanes, such as a mixture of pentanes.

[0058] In another embodiment of the present application, the aromatic resin of component (B) (i.e. the hydrocarbon resin product) comprises a C9 monomer-based resin (such as an indene resin, a coumarone resin, a styrene resin or a phenolic resin), such as an alkyl-phenol resin and a terpene-phenol resin and mixtures thereof. Thus, the C9 monomer-based resin is a polymerisation product of one or more C9 monomers. Preferably, in this embodiment, the C9 monomer-based resin is the major component (greater than 50 wt%, preferably greater than 60 wt%, preferably greater than 80 wt% of the aromatic resin based on component (B)).

[0059] The C9 monomers can include, for example, indene monomers, vinyl-toluene monomers, a-methylstyrene monomers or β-methylstyrene monomers.

[0060] The aromatic resin of component (B) (i.e. the hydrocarbon resin product) is typically based on more than one of the above monomer units, and can be, for example, a coumarone-indene resin, a phenol-modified coumarone-indene resin, an alkyl-phenol resin or a terpene-phenol resin.

[0061] In a preferred embodiment of the present application, the hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) comprises a polymer obtained from the polymerization of terpene units, sesquiterpene units, diterpene units and / or mixtures thereof, more preferably the hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) consists of a polymer obtained from the polymerization of terpene units, sesquiterpene units, diterpene units and / or mixtures thereof. These units can be aliphatic units or alicyclic units, e.g. monocyclic units or bicyclic units; or combinations thereof. A typical example of this embodiment is a polyterpene resin obtained from the catalytic polymerization of the bicyclic monoterpene pinene (β-pinene). The hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) can be obtained from natural substances (e.g. plants) or produced by synthetic reactions.

[0062] Thus, in another preferred embodiment of the present application, the hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) comprises a pine resin, such as rosin (the solid form of pine resin). Pine resin is typically a mixture consisting mainly of terpenes and their derivatives. As mentioned above, the pine resin can be of plant origin or of synthetic origin, i.e. the pine resin of this embodiment can be obtained from plants or prepared by synthetic reactions. In this embodiment, the hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) preferably consists of pine resin.

[0063] In another embodiment, the hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) comprises a partially or fully hydrogenated hydrocarbon resin derived from any of the above-mentioned hydrocarbon resins.

[0064] Preferably, the hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) comprises, preferably consists of, a partially or fully hydrogenated hydrocarbon resin derived from any of the above-mentioned hydrocarbon resins.

[0065] A particularly preferred hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) is a fully hydrogenated aliphatic C5 monomer-based resin.

[0066] Another particularly preferred hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) is an aromatic C9 monomer-based resin.

[0067] The hydrocarbon resin of component (B) (i.e. the hydrocarbon resin product) according to the present application can be in the form of the hydrocarbon resin as such (as received) or in the form of a masterbatch, wherein the hydrocarbon resin is mixed with a carrier.

[0068] Component (B) (i.e. the hydrocarbon resin product) can optionally comprise further ingredients, such as stabilizers as known in the art, supplied by the supplier. The carrier of the optional masterbatch of the hydrocarbon resin product (B) is typically a polymer, e.g. a polyolefin, such as polypropylene, which is compatible with component (A).

[0069] The amount of component (B) (i.e. the hydrocarbon resin product) is preferably 1 to 40 wt.%, more preferably 2 to 40 wt.%, still more preferably 5 to 30 wt.%, still more preferably 7 to 30 wt.% or 10 to 30 wt.%, based on the total polyolefin composition (100 wt.%).

[0070] The term "hydrocarbon resin" has the meaning generally accepted and well known in the art. The hydrocarbon resin product (B) is typically a commercially available product as supplied by the supplier, for example as a masterbatch as indicated above. It is understood here that in case of optional masterbatches or other optional components present in the hydrocarbon resin product (B), the amount of carrier and / or other components is part of the amount of the hydrocarbon resin product (B) based on the polyolefin composition (100 wt.%).

[0071] Nucleating agent (C)

[0072] As already mentioned above, the polyolefin composition according to the present application can comprise a nucleating agent (C).

[0073] Herein nucleating agent (C) means a compound or composition added to a solid polymer for the purpose of increasing the rate of crystallization and results in an increase in the degree of crystallinity of the solid polymer (and typically results in smaller crystal size).

[0074] The optional nucleating agent (C) can be any nucleating agent known in the art. As known to the skilled person, typically there are a- and b-nucleating agents.

[0075] The optional nucleating agent (C) can be introduced during the preparation of the polyolefin composition or it can be present and preferably present in component (A) before mixing of components (A) and (B) during the preparation of the polyolefin composition. Preferably, the nucleating agent (C) is introduced into the propylene homopolymer or copolymer (A), preferably into the propylene homopolymer, during the polymerization of the polymer (A).

[0076] The amount of the optional nucleating agent (C) can vary depending on the desired nucleating effect and can be chosen by the skilled person. In case the nucleating agent (C) is added to e.g. component (A) or the mixture of components (A) and (B) respectively, it can be added as such (pure) or in the form of a masterbatch in the form of the product as supplied by the supplier. In case of an optional product or masterbatch, any other components and / or carrier are calculated as amount of the nucleating agent (C).

[0077] The amount of optional nucleating agent (C) is preferably not more than 10,000 ppm, more preferably not more than 6,000 ppm, even more preferably not more than 5,000 ppm, based on the total polyolefin composition (100 wt.-%). The amount of optional nucleating agent (C) is typically at least 0.01 ppm, based on the total polyolefin composition (100 wt.-%).

[0078] In a preferred embodiment, the optional nucleating agent (C) is present at least in component (A). In this embodiment, the nucleating agent (C) is preferably introduced into the propylene homopolymer or copolymer (A), more preferably into the propylene homopolymer (A), during the polymerization of the polymer (A). In this embodiment, the amount of nucleating agent (C) in component (A) is preferably not more than 500 ppm, more preferably from 0.025 to 200 ppm and most preferably from 0.1 to 100 ppm, based on the combined weight of the propylene homopolymer or copolymer (A) and the nucleating agent (C).

[0079] One preferred embodiment of the optional nucleating agent (C) is an alpha-nucleating agent.

[0080] The optional alpha-nucleating agent (C) is preferably selected from the group consisting of:

[0081] (i) salts of monocarboxylic acids and polycarboxylic acids, and

[0082] (ii) dibenzylidene sorbitols (e.g. 1,3:2,4 dibenzylidene sorbitol) and C1-C8 alkyl substituted dibenzylidene sorbitol derivatives, and

[0083] (iii) salts of phosphoric acid diesters, and

[0084] (iv) vinyl cycloalkane polymers and vinyl alkane polymers, and

[0085] (v) mixtures thereof.

[0086] According to one particularly preferred embodiment, the optional alpha-nucleating agent (C) is a polymeric alpha-nucleating agent, more preferably comprises, still more preferably consists of, and yet more preferably is a vinyl cycloalkane polymer and / or a vinyl alkane polymer (iv) (also referred to herein as (optional) polymeric vinyl compound or polymerized vinyl compound).

[0087] In this regard, it is further preferred that the optional nucleating agent (C) comprises, more preferably consists of, a vinyl cycloalkane polymer and / or a vinyl alkane polymer (iv), wherein the potential vinyl compound has the formula

[0088]

[0089] wherein R 1 and R 2 are independently selected from C1-C4-alkyl groups or together form a saturated five- or six-membered ring, whereby the ring can be substituted and / or bridged by one or more C1- or C2-alkyl groups, and more preferably the vinyl compound is selected from the group consisting of vinylcyclopentane, vinylcyclohexane, vinyl-2-methyl-cyclohexane, vinyl-norbornane, 3-methyl-1-butene and mixtures thereof.

[0090] The optional alpha-nucleating agent (C) can also preferably be selected from polymers of vinyl compounds which satisfy the above formula but wherein R 1 and R 2 do not together form a saturated five- or six-membered ring but an unsaturated or aromatic five- or six-membered ring, whereby the ring can be substituted and / or bridged by one or more C1- or C2-alkyl groups, more preferably the vinyl compound is selected from the group consisting of styrene, p-methylstyrene and mixtures thereof.

[0091] Mixtures between any of the above exemplified vinylcycloalkane polymers and / or vinylalkane polymers and styrene and / or p-methylstyrene are also preferred.

[0092] Most preferred is that the optional alpha-nucleating agent (C) comprises, more preferably consists of, a vinylcyclohexane (VCH) polymer.

[0093] It is further preferred that the respective polymer of the optional vinyl compound is introduced into the propylene homopolymer or copolymer (A) during its polymerization by using the so-called BNT technology. With respect to the BNT technology, reference is made to the international applications WO 99 / 24478, WO 99 / 24479 and in particular WO 00 / 68315. According to this technology, a catalyst system, preferably a Ziegler-Natta procatalyst, in particular comprising a specific Ziegler-Natta procatalyst, an external donor and a cocatalyst, can be modified by polymerizing a vinyl compound as defined above in the presence of the catalyst system. The vinyl compound is as defined above. The polymerized vinyl compound is used as alpha-nucleating agent (C). The weight ratio of the vinyl compound to the solid catalyst component in the modification step of the catalyst is preferably up to 5 (5:1), more preferably up to 3 (3:1), such as in the range of 0.5 (1:2) to 2 (2:1).

[0094] Another preferred embodiment of the optional nucleating agent (C) is a β-nucleating agent (C). The term "β-nucleating agent" refers to any nucleating agent suitable for inducing crystallization of the propylene polymer in a hexagonal or quasi-hexagonal modification. Mixtures of these nucleating agents can also be used.

[0095] A suitable type of the optional β-nucleating agent (C) is a dicarboxylic acid derivative bisamide compound from C5-C8-cycloalkyl monoamines or C6-C12-aromatic monoamines and C5-C8-aliphatic dicarboxylic acids, C5-C8-cycloaliphatic dicarboxylic acids or C6-C12-aromatic dicarboxylic acids, such as N,N'-di-C5-C8-cycloalkyl-2,6-naphthalene dicarboxylic amide compounds.

[0096] Further suitable optional β-nucleating agents (C) are quinacridone compounds or quinacridonequinone compounds. Still further suitable optional β-nucleating agents (C) are dicarboxylic acid salts of metals from group 11a of the periodic table, which are well known and described in the literature.

[0097] Such nucleating agents are commercially available and described, for example, in "Plastic Additives Handbook", 5thEdition, 2001 by Hans Zweifel (pages 967 to 990).

[0098] Preferably, the polymer composition comprises a nucleating agent (C). Preferably, in this embodiment, the nucleating agent (C) is present at least in component (A). The nucleating agent (C) is preferably an α-nucleating agent (C) as defined above, including suitable and preferred subgroups thereof, for example, a polymeric α-nucleating agent (C).

[0099] It is preferred that components (A) and (B) (preferably (A), (B) and (C)) together constitute at least 80 wt.-%, more preferably at least 85 wt.-%, still more preferably at least 90 wt.-% (such as at least 95 wt.-% or at least 98 wt.-%) of the polyolefin composition of the present application. In addition to components (A) and (B) (preferably (A), (B) and (C)), the polyolefin composition can comprise and preferably comprises conventional additives. In a particular embodiment, the polyolefin composition consists of components (A) and (B) (preferably (A), (B) and (C)) and additives. Herein, it is understood that "additives" do not comprise the hydrocarbon resin product (B) nor the nucleating agent (C), i.e. components (B) and (C) are not considered "additives" herein.

[0100] The additives are preferably present in the polymer composition and can be present partially or completely in component (A), (B), optionally (C), and / or are added partially or completely to the polymer composition during the production of the polymer composition. The additives are suitably selected from the group of primary antioxidants (such as sterically hindered phenols) and secondary antioxidants (such as phosphites), UV stabilizers (such as sterically hindered amines), acid scavengers, carbon black, pigments, antistatic agents (such as glycerol monostearate), slip agents (such as oleamide), plasticizers, anti-scratch agents, dispersion aids, processing aids, lubricants, etc.

[0101] These additives are commercially available and are described in, for example, "Plastic Additives Handbook", 6th edition, 2009 by Hans Zweifel (pages 1141 to 1190) and are generally used in conventional amounts.

[0102] Furthermore, the additives can be added as such (neat) or in products provided by the suppliers (including masterbatches, wherein the additives are together with a carrier material). Any carrier material of the optional masterbatches is calculated as amount of additive based on the amount of the polymer composition (100 wt%).

[0103] The optional polymer carrier material, if any, of the hydrocarbon resin (B), the optional nucleating agent (C) or the optional additives is a carrier polymer to ensure a uniform distribution in the extruder during the production of the film. The optional polymer carrier material is not limited to a specific polymer. The optional polymer carrier material can be an ethylene homopolymer, an ethylene copolymer derived from ethylene and an alpha-olefin comonomer (such as a C3 to C8 alpha-olefin comonomer), a propylene homopolymer and / or a propylene copolymer derived from propylene and an alpha-olefin comonomer (such as ethylene and / or a C4 to C8 alpha-olefin comonomer).

[0104] Polymer (D)

[0105] The polymer composition of the present application can comprise a further polymer (D) in addition to the propylene homopolymer or copolymer (A) and the hydrocarbon resin product (B). In case of the optional further polymer (D), the amount of the component is less than 15 wt%, preferably less than 10 wt%, more preferably less than 9 wt% based on the weight of the polyolefin composition. It is understood here that any carrier polymer for the hydrocarbon resin product (B), the optional nucleating agent (C) or the optional additives is not included in the definition of the optional further polymer (D) and is not calculated as amount of the further polymer (D). Preferably, the polyolefin composition of the present application does not comprise a further polymer (D).

[0106] Polyolefin composition

[0107] The polyolefin composition of the present application preferably has an oxygen transmission rate d (1 mm film) of less than 61 ml / m 2 • d (1 mm film), preferably less than 60 ml / m 2 • d (1 mm film), such as 20 to 60 ml / m 2 • relative (normalized to 1 mm film thickness) oxygen transmission rate d (1 mm film).

[0108] The polyolefin composition of the present application preferably has a tensile modulus in machine direction (MD) of at least 1,000 MPa, preferably at least 1,200 MPa, preferably 1,000 to 4,000 MPa, preferably 1,200 to 3,000 MPa, when measured from film samples as described in the "Examples".

[0109] The polyolefin composition of the present application preferably has a tensile modulus in transverse direction (TD) of at least 1,000 MPa, preferably at least 1,200 MPa, preferably 1,000 to 4,000 MPa, preferably 1,200 to 3,000 MPa, when measured from film samples as described in the "Examples".

[0110] According to certain embodiments, the polyolefin composition according to the present application as detailed above does not comprise one, two, three or all of the following four blends:

[0111] - a blend of a polypropylene polymer having an MFR2 of 2.9 g / 10 min, 15 wt% of a dicyclopentadiene-based hydrocarbon resin having a softening point of 140°C and 180 ppm of a nucleating agent

[0112] - a blend of a propylene homopolymer having a density of 0.91 g / cm 3 and a melt index of 2.0 g / 10 min, 15 wt% of a fully hydrogenated hydrocarbon resin having a softening point of 125°C and 3,000 ppm of 1,3:2,4- dibenzylidenesorbitol

[0113] - a blend comprising a propylene ethylene random copolymer having a melt index of 7.2 g / 10 min at 230°C and a load of 2.16 kg, 0.3 wt% or 1.0 wt% of a hydrocarbon resin and 0.05 wt% of calcium stearate

[0114] - a blend of 83.3 wt% of a polypropylene, 14.7 wt% of a hydrocarbon resin, 0.08 wt% of a nucleating agent and 1.92 wt% of a low density polyethylene.

[0115] Use of the polyolefin composition and articles comprising the polyolefin composition

[0116] The polyolefin composition of the present application, i.e. any one of the three aspects of the polyolefin composition according to the present application, including all preferred embodiments thereof, is preferably used for the preparation of an article, more preferably a non-oriented film. Thus, the present application also relates to the use of the polyolefin composition according to the present application as described above for the preparation of an article, preferably a non-oriented film.

[0117] The present application also relates to an article, preferably a non-oriented film, such as a cast film, comprising, more preferably consisting of, at least 80 wt.-%, still more preferably at least 95 wt.-%, of the polyolefin composition according to the present application as described above, i.e. any one of the three aspects of the polyolefin composition according to the present application, including all preferred embodiments thereof.

[0118] A non-oriented film is also commonly referred to as an unoriented film.

[0119] A distinction between unoriented and oriented films is described, for example, in the polypropylene handbook, Nello Pasquini, 2nd edition, Hanser. Oriented films are typically mono- or biaxially oriented films, whereas unoriented films are cast, blown or tubular films. Thus, unoriented films are intentionally not stretched in the solid or near solid state in the longitudinal and / or transverse direction as oriented films are, i.e. unoriented films in the present context mean films which are not intended to be oriented. Thus, as clear to the skilled person, unoriented films are not mono- or biaxially oriented films.

[0120] Non-oriented films include cast films, tubular quench films and blown films. Cast films are particularly preferred.

[0121] The non-oriented film of the present application can be a monolayer film or a multilayer film.

[0122] The thickness of the film is not critical, but is typically in the range of 20 to 200 pm.

[0123] The monolayer film of the present application comprises, preferably consists of, at least 80 wt.-%, preferably at least 95 wt.-%, of the polymer composition of the present application.

[0124] The monolayer film of the present application comprises, based on the monolayer film (100 wt.-%), preferably hydrocarbon resin product (B) in an amount of 1 to 40 wt.-%, more preferably 2 to 40 wt.-%, and still more preferably 5 to 30 wt.-%, 7 to 30 wt.-% or 10 to 30 wt.-%.

[0125] The thickness of the monolayer film according to the present application is typically between 20 and 200 pm, suitably between 20 and 100 pm.

[0126] The multilayer film according to the present application comprises at least one layer comprising the polymer composition according to the present application. The one or more layers of the multilayer film comprising the polyolefin composition according to the present application as described above can be any one or more layers, for example one or more core layers or outer layers. The thickness of one layer of the multilayer film (each layer comprising the polyolefin composition according to the present application as described above) can vary between 1 and 200 pm, suitably between 1 and 190 pm, depending on the function of the layer, i.e. whether the function of the layer is for example as an outer layer (skin layer) or as a core layer, and thus is selected as known to the skilled person. For example, the outer layer can have a thickness of 2 to 3 pm and the thickness of the core layer can for example be 20 to 200 pm, such as 20 to 100 pm.

[0127] At least one layer of the multilayer film according to the present application comprises at least 80 wt.-%, preferably at least 95 wt.-%, of the polymer composition according to the present application, preferably consists of the polymer composition according to the present application.

[0128] The non-oriented film according to the present application, preferably a cast film, is preferably transparent.

[0129] The non-oriented film according to the present application, preferably a cast film, preferably has excellent optical properties, for example one, more or all (preferably all) of reduced haze, increased gloss and increased transparency (amount of light passing through the film).

[0130] The non-oriented film according to the present application, preferably a cast film, can be conventionally prepared as known in the art by extruding the polyolefin composition according to the present application (i.e. the pre-obtained melt mixture thereof) through a die having the dimensions required for the final film application.

[0131] Upon leaving the die in the extrusion step, the molten film immediately enters a cooling step in which the temperature of the film is reduced to solidify the film.

[0132] In a preferred embodiment, the non-oriented film, such as a cast film, is obtained by a process comprising the steps of:

[0133] (a) providing components for preparing a film comprising components (A) and (B),

[0134] (b) blending the components prior to or during melt mixing in an extruder for preparing the film,

[0135] (c) extruding the film via the extruder,

[0136] (d) cooling the resulting film, and

[0137] (e) recovering the resulting film.

[0138] In the extrusion step (c), the extrusion of the film, as is well known in the art, is by extruding the molten mixture of the polymer composition through a die having the dimensions required for the final film application.

[0139] Upon leaving the die in the extrusion step (c), the molten film immediately enters the cooling step (d) in which the temperature of the film is reduced to solidify the film.

[0140] Preferably, the cooling step (d) of the process for preparing the non-oriented film according to the application comprises cooling the extruded film at a cooling temperature, wherein the cooling temperature is higher than the cooling temperature of a film having the same components in the same relative amounts except that it does not contain the hydrocarbon resin product (B).

[0141] The cooling step (d) is generally performed rather quickly, i.e. at rather low cooling temperatures, because otherwise the resulting film is hazy. Surprisingly, according to the present application, the process can be performed at a relatively higher cooling temperature and a film with good optical properties is obtained.

[0142] According to a particularly preferred embodiment of the present application, the non-oriented film is a cast film and the cooling step (d) of the extruded film is performed by means of a cooling roll having a temperature of 20-90°C, more preferably 20-80°C, still more preferably 20-70°C, yet more preferably 20-60°C.

[0143] In some embodiments, the temperature of the cooling roll can also be 40-90°C, more preferably 40-80°C, yet more preferably 40-70°C, yet more preferably 40-60°C.

[0144] In some embodiments, the temperature of the cooling roll can also be 50-90°C, more preferably 50-80°C, still more preferably 50-70°C, yet more preferably 50-60°C.

[0145] The cast film process is well known to the skilled person and is well described in the literature.

[0146] According to another, but still preferred, embodiment of the present application, the non-oriented film is a blown film and the cooling step (d) of the extruded film is performed by means of air.

[0147] According to another, but still preferred, embodiment of the present application, the non-oriented film is a tubular quench film and the cooling step (d) of the extruded film is performed by means of water.

[0148] The processes for producing blown films with air cooling and tubular quench films with water cooling are known to the skilled person and are well described in the literature.

[0149] The non-oriented film of the present application is preferably a cast film, preferably a single layer cast film, comprising, preferably consisting of, the polyolefin composition of the present application as described above.

[0150] The present application also relates to the use of a hydrocarbon resin product comprising a hydrocarbon resin in a non-oriented film comprising a propylene homopolymer or copolymer, wherein said hydrocarbon resin of the hydrocarbon resin product has a weight average molecular weight of 500 to 5,000 g / mol, preferably of 700 to 3,000 g / mol, or a melt viscosity of 80 to 400 mPa.s at 200°C, preferably of 100 to 400 mPa.s at 200°C, more preferably of 150 to 400 mPa.s at 200°C, or a softening point of 200°C or less, preferably of 180°C or less, more preferably of 170°C, for improving the oxygen barrier properties of said non-oriented film. The softening point is preferably 70°C or more.

[0151] In a preferred embodiment, the present application relates to the use of a hydrocarbon resin product comprising a hydrocarbon resin in a non-oriented film comprising a propylene homopolymer or copolymer, wherein said hydrocarbon resin of the hydrocarbon resin product has a weight average molecular weight of 500 to 5,000 g / mol, preferably of 700 to 3,000 g / mol, and a melt viscosity of 80 to 400 mPa.s at 200°C, preferably of 100 to 400 mPa.s at 200°C, more preferably of 150 to 400 mPa.s at 200°C, and optionally a softening point of 200°C or less, preferably of 180°C or less, more preferably of 170°C, for improving the oxygen barrier properties of said non-oriented film. The softening point is preferably 70°C or more.

[0152] In another preferred embodiment, the present application relates to the use of a hydrocarbon resin product comprising a hydrocarbon resin in a non-oriented film comprising a propylene homopolymer or copolymer, wherein said hydrocarbon resin of the hydrocarbon resin product has a weight average molecular weight of 500 to 5,000 g / mol, preferably of 700 to 3,000 g / mol, and a softening point of 200°C or less, preferably of 180°C or less, more preferably of 170°C, for improving the oxygen barrier properties of said non-oriented film. The softening point is preferably 70°C or more.

[0153] In a preferred embodiment, the present application relates to the use of a hydrocarbon resin product comprising a hydrocarbon resin in a non-oriented film comprising a propylene homopolymer or copolymer, wherein said hydrocarbon resin of the hydrocarbon resin product has a melt viscosity of 80 to 400 mPa.s at 200°C, preferably of 100 to 400 mPa.s at 200°C, more preferably of 150 to 400 mPa.s at 200°C, and a softening point of 200°C or less, preferably of 180°C or less, more preferably of 170°C, for improving the oxygen barrier properties of said non-oriented film. The softening point is preferably 70°C or more.

[0154] Preferably, the oxygen barrier properties of the non-oriented film comprising the hydrocarbon resin product and the propylene homopolymer or copolymer are improved when the oxygen permeability of the non-oriented film is reduced by at least 15 %, more preferably by at least 30 %, still more preferably by at least 35 %, based on the same non-oriented film except that it does not comprise the hydrocarbon resin product.

[0155] With respect to this use according to the present application, it is also independently preferred that:

[0156] (a) the propylene homopolymer or copolymer is component (A) as defined above in connection with the polyolefin composition according to the present application (including the preferred embodiments),

[0157] and / or

[0158] (b) the non-oriented film comprises a nucleating agent as defined above for optional component (C) in connection with the polyolefin composition according to the present application (including the preferred embodiments), wherein the nucleating agent is comprised in the propylene homopolymer or copolymer,

[0159] and / or

[0160] (c) the hydrocarbon resin of the hydrocarbon resin product is further defined as defined above for the preferred embodiments of component (B) in connection with the polyolefin composition according to the present application,

[0161] and / or

[0162] (d) the non-oriented film is a cast film,

[0163] and / or

[0164] (e) the non-oriented film (single layer film) or at least one layer thereof (multi layer film) consists of the polyolefin composition as defined above in connection with the polyolefin composition according to the present application.

[0165] It is particularly preferred that items (a), (b) and (c) defined above are jointly fulfilled, even more preferably items (a), (b), (c) and (d) are jointly fulfilled, still more preferably item (e) is fulfilled, still more preferably items (e) and (d) are fulfilled, still more preferably all items (a), (b), (c), (d) and (e) defined above are jointly fulfilled.

[0166] The present application will now be further described in detail by the examples provided below.

[0167] Examples

[0168] 1. Definition / Measurement Methods

[0169] The following definitions of terms and determination methods apply for the above general description of the application as well as in the examples below unless otherwise defined.

[0170] MFR2 is measured according to ISO 1133 with a 2.16 kg load at 230 °C.

[0171] Pentad isotacticity (mmmm) is determined by 13 C NMR spectroscopy.

[0172] Quantitative nuclear-magnetic resonance (NMR) spectroscopy was employed to quantify the stereo-regularity (tacticity) and regio-regularity of the polymers.

[0173] Quantitative 1 H and 13 C NMR spectroscopy was recorded in solution state on a Bruker Advance III 400 NMR spectrometer operating at 400.15 and 100.62 MHz for 13 C, 1 H} respectively. Nitrogen was used for all pneumatic devices and all spectra were recorded at 125 °C using a 10 mm extended temperature probe optimized for 13 C.

[0174] For polypropylene homopolymers, about 200 mg of material was dissolved in 1,2-tetrachloroethane-d2(TCE-d2). To ensure a homogeneous solution, after the initial sample was prepared in the heating block, the NMR tube was further heated in a rotating oven for at least 1 hour. After insertion into the magnet, the tube was spun at 10 Hz. This setting was chosen mainly for the high resolution required for tacticity distribution quantification (Busico, V., Cipullo, R., Prog. Polym. Sci. 26 (2001) 443; Busico, V.; Cipullo, R., Monaco, G., Vacatello, M., Segre, A. L., Macromolecules 30 (1997) 6251). Standard single-pulse excitation was used with NOE and bi-level WALTZ16 decoupling schemes (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225; Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 11289). A total of 8192 (8k) transients were acquired for each spectrum.

[0175] Quantitative13 C{ 1 H}NMR spectra were processed, integrated, and the relevant quantitative properties were determined from the integrals.

[0176] For polypropylene homopolymer, all chemical shifts are internally referenced to the methyl isotactic pentad (mmmm) at 21.85 ppm.

[0177] The tacticity distribution was quantified by integrating the methyl region between 23.6 and 19.7 ppm, correcting for any sites not related to the stereosequence of interest (Busico, V., Cipullo, R., Prog. Polym. Sci. 26 (2001) 443; Busico, V., Cipullo, R., Monaco, G., Vacatello, M., Segre, A. L., Macromoleucles 30 (1997) 6251).

[0178] Specifically, the influence of regio defects and comonomer integration on the quantification of tacticity distribution was corrected by subtracting representative regio defects and comonomer integrals from the specific integration region of the stereosequence.

[0179] The isotacticity was determined at the pentad level and reported as the percentage of isotactic pentad (mmmm) sequences relative to all pentad sequences:

[0180] [mmmm] % = 100 * (mmmm / sum of all pentads)

[0181] The presence of 2,1 erythro regio defects was determined by the presence of two characteristic methyl sites at 17.7 and 17.2 ppm, respectively, and confirmed by other characteristic sites.

[0182] Characteristic signals corresponding to other types of regio defects were not observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253).

[0183] The amount of 2,1 erythro regio defects was quantified using the average integration of the two characteristic methyl sites at 17.7 and 17.2 ppm:

[0184] P 21e = (I e6 + I e8 ) / 2

[0185] The amount of 1,2 primary inserted propylene was quantified based on the methyl region, where the sites contained in this region that are not related to primary insertion and the primary insertion sites excluded from this region were corrected:

[0186] P 12 = I CH3 + P 12e

[0187] The total amount of propylene is quantified as the sum of the propylene of the main insertion and all other region defects present:

[0188] P 总共 = P 12 + P 21

[0189] The molar percentage of 2,1 erythro region defects is quantified relative to all propylene:

[0190] [21e] mol% = 100 * (P 21e / P 总共 )

[0191] Quantitative nuclear-magnetic resonance (NMR) spectroscopy is employed to quantify the comonomer content of the polymers.

[0192] Quantitative 1 H and 13 C{NMR spectra are recorded in solution state using a Bruker Advance III 400 NMR spectrometer operating at 400.15 and 100.62 MHz for 13 C{ and 1 H} respectively. Nitrogen is used for all pneumatic devices and all spectra are recorded at 125 °C using a 10 mm extended temperature probe optimised for 13 C. Approximately 200 mg of material is dissolved in 3 ml of 1,2-tetrachloroethane-d2 (TCE-d2) with chromium (III) acetylacetonate (Cr(acac)3) to give a 65 mM solution of relaxer in solvent as described in G. Singh, A. Kothari, V. Gupta, Polymer Testing 2009, 28(5), 475.

[0193] To ensure a homogeneous solution, after the initial sample was prepared in the heating block, the NMR tube was further heated in a rotating oven for at least 1 hour. After insertion into the magnet, the tube was spun at 10 Hz. This setting was chosen mainly for high resolution and quantitatively to need to quantify the exact ethylene content. Standard single pulse excitation without NOE was used, using optimized flip angles, 1 second recycle delay and a double- level WALTZ16 decoupling scheme as described in Z. Zhou, R. Kuemmerle, X. Qiu, D. Redwine, R. Cong, A. Taha, D. Baugh, B. Winniford, J. Mag. Reson. 187 (2007) 225 and V. Busico, P. Carbonniere, R. Cipullo, C. Pellecchia, J. Severn, G. Talarico, Macromol. Rapid Commun. 2007, 28, 1128. A total of 6144 (6k) transients were acquired per spectrum.

[0194] Quantification 13 C{ 1 The NMR spectra were processed, integrated and from the integrals the relevant quantitative properties were determined. Using the chemical shift of the solvent, all chemical shifts were indirectly referenced to the central methylene group of the ethylene block (EEE) at 30.00 ppm. Even if this structural unit is not present, this approach can be made to a comparable reference.

[0195] Since characteristic signals corresponding to 2,1 erythro regio defects were observed (as described in L. Resconi, L. Cavallo, A. Fait, F. Piemontesi, Chem. Rev. 2000, 100(4), 1253, in Cheng, H. N., Macromolecules 1984, 17, 1950 and in W-J. Wang and S. Zhu, Macromolecules 2000, 33, 1157), a correction for the influence of regio defects on the determination of the properties was necessary. No characteristic signals corresponding to other types of regio defects were observed.

[0196] Characteristic signals corresponding to ethylene incorporation were observed (as described in Cheng, H. N., Macromolecules 1984, 17, 1950) and the comonomer fraction was calculated as the fraction of ethylene in the polymer relative to all monomers in the polymer.

[0197] The method of W-J. Wang and S. Zhu, Macromolecules 2000, 33 1157 was used to calculate the fraction of 2,1 erythro regio defects by integration of the signals at 18.5 and 18.6 ppm. 13 C{ 1H} The integral of the multiple signals over the entire spectral region in the spectrum was used to quantify the comonomer fraction. This method was chosen because of its robust nature and the ability to indicate the presence of regional defects if needed. The integration region was slightly adjusted to improve applicability over the entire range of comonomer contents encountered.

[0198] Mole percent comonomer incorporation was calculated from mole fraction.

[0199] Weight percent comonomer incorporation was calculated from mole fraction.

[0200] Vicat softening temperature: The softening point of a soft plastic can be measured according to the ISO 306:2013 standard method on a 240 x 240 x 4 mm test specimen plaque with a conditioning time of 96 hours or more, a heating rate of 50 K / h and a load of 10 N.

[0201] Softening point was measured according to ASTM-E28.

[0202] Melting temperature (T m ), crystallization temperature (T cr ) and degree of crystallinity: The melting temperature of the employed polymer was measured according to ASTM D3418. The T m and T cr of a 3 + / - 0.5 mg sample were measured with a Mettler TA820 differential scanning calorimetry (DSC). Both the crystallization and melting curves were obtained during cooling and heating scans between -10 and 200 °C at 10 °C / min. The melting and crystallization temperatures were taken as the endothermic and exothermic peaks. The degree of crystallinity was calculated by comparison with the heat of fusion of a perfectly crystalline polymer of the same polymer type (e.g. 290 J / g for polyethylene).

[0203] Glass transition temperature (T g ) was measured by dynamic mechanical analysis according to ISO 6721-7. Measurements were made on compression molded samples (40 · 10 · 1 mm 3 ) in torsion mode between -100 °C and +150 °C with a heating rate of 2 °C / min and a frequency of 1 Hz.

[0204] Flexural modulus: The flexural modulus was measured according to ISO 178. Test specimens of dimensions 80 x 10 x 4.0 mm 3 (length x width x thickness) were prepared by injection molding according to EN ISO 1873-2. The test specimens were conditioned at 23 °C and 50 % relative humidity. The span length between the supports was 64 mm, the test speed was 2 mm / min and the pressure was 100 N.

[0205] The content of xylene cold solubles (XCS) was measured at 25°C according to ISO 16152; First Edition; 2005-07-01.

[0206] Number average molecular weight (M n ), weight-average molecular weight (M w ) and polydispersity (M w / M n The following method was used to measure the sample using gel permeation chromatography (GPC):

[0207] Weight-average molecular weight (Mw) and polydispersity (M w / M n M n It is the number average molecular weight and M w The weight-average molecular weight (MA) was measured using methods based on ISO 16014-1:2003 and ISO 16014-4:2003. A Waters Alliance GPCV 2000 instrument equipped with a refractive index detector and an online viscometer was used with a 3×TSK-gel column (GMHXL-HT) from TosoHaas and 1,2,4-trichlorobenzene (TCB, stabilized with 200 mg / L 2,6-di-tert-butyl-4-methylphenol) as solvent at a constant flow rate of 1 mL / min at 145 °C. 216.5 μL of sample solution was injected for each analysis. The column setup was calibrated by relative calibration using 19 narrow MWD polystyrene (PS) standards ranging from 0.5 kg / mol to 11500 kg / mol and a set of well-characterized broad polypropylene standards. All samples were prepared by dissolving 5–10 mg of polymer in 10 mL of stabilized TCB (same as the mobile phase) at 160 °C and keeping the solution under continuous shaking for 3 hours before loading it onto the GPC instrument.

[0208] Melt viscosity was measured according to ASTM D-3236.

[0209] Transparency, haze, and clarity: All optical parameters of a 40 μm thick cast film were measured. Transparency, haze, and clarity were measured according to ASTM D 1003.

[0210] The gloss is measured at a 60° angle according to DIN 67530 for a 40 μm thick cast film.

[0211] Tensile tests (modulus, strength and elongation at break) were performed at 23°C using a 40 μm thick cast film, in accordance with ISO 527-1 (Type 2 specimen, 15 mm wide, crosshead speed of 1 mm / min) and ISO 527-3 (Type 2 specimen, 15 mm wide, speed of 200 mm / min).

[0212] Oxygen barrier properties (i.e. oxygen transmission rate) were measured on cast films of 40 μιη thickness. The sample was mounted as a sealed half-barrier between two chambers at ambient atmospheric pressure. One chamber was slowly purged with a mixture of nitrogen and hydrogen (2% H2in N2) at a given temperature and relative humidity, and the other chamber was purged with an oxygen stream instead of the N2stream at the same temperature and relative humidity. As oxygen permeates the film into the nitrogen carrier gas, it is transported to a coulometric detector where it generates an electric current proportional to the amount of oxygen flowing into the detector per unit time. Oxygen transmission rate (OTR) tests were performed according to ASTM D 3985 at 23°C and 0% relative humidity using 10 seem of N2 / H2and O2(99.999%) gases and a 1 cm2film surface area. 2 Oxygen transmission rate (OTR) tests were performed according to ASTM D 3985 at 23°C and 0% relative humidity using 10 seem of N2 / H2and O2(99.999%) gases and a 1 cm2film surface area.

[0213] 2. Examples

[0214] In the following Inventive Examples (IE) and Comparative Examples (CE), the following compounds were used.

[0215] HD915CF is a propylene homopolymer containing 200 ppm or less of nucleating agent. It has an MFR2of 8 g / 10 min, a melting temperature of 164-170°C, a flexural modulus of 2,100 MPa and a Vicat softening temperature of 158°C.

[0216] HD601CF is a propylene homopolymer. The polymer does not contain any nucleating agent. HD601CF has an MFR2of 8 g / 10 min, a melting temperature of 164°C, a flexural modulus of 1,450 MPa and a Vicat softening temperature of 154°C.

[0217] HD915CF and HD601CF are commercially available from Borealis AG or Borouge, respectively.

[0218] Arkon P-125 is a fully hydrogenated hydrocarbon resin and is commercially available from Arakawa Chemical Industries, Ltd., Japan. The hydrocarbon resin has a softening point (ASTM E-28) of 125°C, a weight average molecular weight Mwof 1300 g / mol, and a melt viscosity of 300 mPa.s at 200°C measured according to ASTM D-3236. w

[0219] ​Constab MA930PP is a masterbatch containing 60 wt.-% of a fully hydrogenated hydrocarbon resin and is commercially available from Constab Polyolefin Additives GmbH. The hydrocarbon resin has a softening point of 150 °C (ASTM E-28), a weight average molecular weight Mw of 800 g / mol and a melt viscosity of 200 mPa.s at 200 °C measured according to ASTM D-3236. w and a melt viscosity of 200 mPa.s at 200 °C measured according to ASTM D-3236.

[0220] HPN20E is an alpha-nucleating agent commercially available from Milliken Chemical.

[0221] Preparation of cast film samples

[0222] Cast films with a thickness of about 40 pm were prepared from propylene homopolymer compounded with a hydrocarbon resin (product) and / or, if any, an alpha-nucleating agent on a Collin equipment with different cooling roll (CR) temperatures.

[0223] Single layer films were cast co-extruded (three extruders fed with the same product in structure 1 / 2 / 1).

[0224] Total thickness: 40 pm

[0225] Total throughput: 6 kg / h

[0226] Melt temperature: 210-220 °C depending on the test sample

[0227] The cooling roll temperature was between 20 and 50 °C depending on the trial, as shown in the following Table 1.

[0228] In case of the inventive example, the melt pressure is reduced. The more component (B) the more the melt pressure is reduced.

[0229] The following table shows the films prepared according to the inventive example (IE) and the comparative example (CI) and the resulting properties.

[0230] In the following table, the following abbreviations and units are used:

[0231] P1 stands for Polymer 1, HD601 CF

[0232] P2 stands for Polymer 2, HD915 CF

[0233] HR1 stands for hydrocarbon resin product 1, Arkon P-125, in an amount of 10 or 20 wt.-%

[0234] HR2 stands for hydrocarbon resin product 2, Constab MA930PP, in an amount of 10 or 20 wt.-%

[0235] NA stands for nucleating agent, HPN20E, in an amount of 500 or 1,000 ppm

[0236] CRT stands for chill roll temperature

[0237] TH stands for thickness of the cast film

[0238] OTR stands for oxygen transmission rate, average of three measurements, SD is the standard deviation; for films of 40.0 pm thickness

[0239] Calculated values and calculated values for films of 1 mm thickness

[0240] HZ stands for haze

[0241] GL stands for gloss

[0242] TM stands for tensile modulus; MD is machine direction, TD is transverse direction

[0243] Table 1: Composition and properties of cast films

[0244]

[0245] The overview shown in Table 1 demonstrates the very effective properties of the present application, as shown in the inventive examples. In the inventive examples, the oxygen transmission rate is greatly reduced to values comparable to BOPP films of the same thickness. However, the good optical properties are retained, and the mechanical properties (i.e. tensile modulus) are improved. This offers the possibility to package more sensitive foodstuffs. Alternatively, the film thickness can be reduced, or the additional layer lamination can be saved, while maintaining the same oxygen transmission rate.

[0246] The presence of the hydrocarbon resin allows the polypropylene-based cast film (CPP) to be processed at higher chill roll temperatures, i.e. without producing hazy films. As can be seen from examples CE1-CE3, the increase in chill roll temperature does not affect the oxygen transmission rate in the absence of any nucleating agent, whereas examples CE4-CE6 with nucleating agent show an effect on the oxygen transmission rate at higher chill roll temperatures (i.e. 50°C). However, it is known to the skilled person that chill roll temperatures higher than 30°C result in hazy films. This is confirmed by the properties of CE6. The addition of the nucleating agent as an additive (CE7-CE10) either reduces (i.e. improves) the oxygen transmission rate (compare CE3 with CE7 and CE8) or further improves the oxygen transmission rate (compare CE6 with CE9 and CE10), respectively. However, the properties of CE10 confirm that hazy films are produced.

[0247] The addition of hydrocarbon resin further improved the oxygen transmission rate (compare CE9 with IE1). As the amount of hydrocarbon resin increased, the effect on the oxygen transmission rate also increased (compare IE2 with IE3, IE4 with IE5). These greatly improved oxygen transmission rate films showed acceptable optical properties and enhanced tensile modulus (see IE3 and IE5). The films of the present application also had excellent processability.

[0248] The use of hydrocarbon resin in cast films comprising propylene homopolymers or copolymers according to one aspect of the present application improved the oxygen barrier properties of the cast films, the oxygen transmission rate of the cast films was reduced by at least 15% based on the same cast film except that it did not contain the hydrocarbon resin (compare CE6 with IE2, OTR reduced by 20%; compare CE6 with IE3, OTR reduced by 32%; compare CE6 with IE5, OTR reduced by 35%).

[0249] Table 2 below shows the same examples and cast films as Table 1, in addition providing additional information regarding the measured oxygen transmission rate values.

[0250] Table 2: Composition and properties of cast films

[0251]

Claims

1. A non-oriented cast film comprising a polyolefin composition, said polyolefin composition comprising -(A) A propylene homopolymer or copolymer having an MFR2 of 0.5-80 g / 10 min as measured according to ISO 1133. -(B) A hydrocarbon resin product comprising a hydrocarbon resin, wherein the hydrocarbon resin is characterized by: Weight-average molecular weight of 500-5000 g / mol or Melt viscosity of 80-400 mPa·s at 200°C, measured according to ASTM D-3236. or According to the softening point of 200°C or lower as measured by ASTM E-28, Or in any combination of them, and -(C) Nucleating agent, In this composition, based on the total polyolefin composition, the amount of component (A) is 70-90% by weight. In this composition, based on the total polyolefin composition, the amount of component (B) is 10-30% by weight. During the polymerization of component (A), the nucleating agent (C) is introduced into the propylene homopolymer or copolymer (A), and based on the combined weight of the propylene homopolymer or copolymer (A) and the nucleating agent (C), the amount of the nucleating agent (C) in component (A) is from 0.1 to 100 ppm. The components (A), (B), and (C) together constitute at least 95% by weight of the polyolefin composition. The non-oriented cast film is obtained from the polyolefin composition in the cast film production method, wherein the cooling roller has a temperature of 40-90°C.

2. The non-oriented cast film comprising a polyolefin composition according to claim 1, wherein the nucleating agent is an α-nucleating agent.

3. The non-oriented cast film comprising a polyolefin composition according to claim 2, wherein the nucleating agent (C) is a polymer α-nucleating agent.

4. The non-oriented cast film comprising a polyolefin composition according to claim 3, wherein the nucleating agent (C) is selected from the group consisting of vinyl cycloalkane polymers and vinyl alkane polymers and mixtures thereof.

5. The non-oriented cast film comprising a polyolefin composition according to claim 4, wherein the nucleating agent (C) comprises a vinylcyclohexane polymer.

6. The non-oriented cast film comprising a polyolefin composition according to claim 4, wherein the nucleating agent (C) is composed of a vinylcyclohexane polymer.

7. A non-oriented cast film comprising a polyolefin composition according to any one of claims 1 to 6, wherein component (A) is a propylene copolymer, the comonomer in component (A) is ethylene and / or C4-C8-α-olefin, and the content of the comonomer is less than 7.5 mol% based on the propylene copolymer.

8. The non-oriented cast film comprising a polyolefin composition according to any one of claims 1 to 6, wherein component (A) is a propylene homopolymer.

9. A non-oriented cast film comprising a polyolefin composition according to any one of claims 1 to 6, wherein the propylene homopolymer or copolymer (A) has a melt temperature (T0) of at least 150.0°C as measured by differential scanning calorimetry (DSC). m ).

10. A non-oriented cast film comprising a polyolefin composition according to any one of claims 1 to 6, wherein the propylene homopolymer or copolymer (A) has - Flexural modulus of at least 1400 MPa as measured according to ISO 178 and / or - Vicat softening temperature of at least 140°C as measured according to ISO 306.

Images