ES2348565T3 - POLYOLEFINE COMPOSITIONS. - Google Patents

Abstract

- Polyolefin compositions comprising, in percentage by weight, with reference to the sum of components 1) and 2): 1) 55-80% of a homopolymer or copolymer of propylene, containing, said copolymer, a percentage of up to a 15%, of ethylene and / or α-olefin (s) C4-C10. 2) 20-45%, of an ethylene copolymer, with one or more C4-C10 α-olefin (s), containing a percentage of 10 to 40%, of said C4-C10 α-olefin (s) ; having, said compositions, a value of MFR (fluidity index), measured in accordance with ASTM 1238, at a temperature of 230 ° C, and at 2.16 kg; 1 to 40 g / 10 minutes, a total ethylene content of 20%, or more, a total C4-C10 α-olefin content (s) of 4.5%, or more, a ratio factor of total ethylene content, with respect to the total content of C4-C10 α-olefin (s), of 2.3 or more, a total fraction soluble in xylene, at room temperature, of 20%, by weight, or greater , and a flexural modulus, referred to as a reactor grade, of more than 770 MPa, measured in accordance with ISO 178.

Description

The present invention relates to polyolefin compositions, comprising a propylene polymer component, selected from propylene homopolymers and random copolymers of propylene containing ethylene and / or other α-olefins as comonomers, and an ethylene copolymer with α - C4-C10 olefins.

The compositions of the present invention can easily be converted into various types of finished articles.

or semi-finished.

The compositions of the present invention having reduced values of MFR (fluidity index - [MFR, of its initials in English] -), are suitable for applications of films or films, in a particular way, for films or films per casting and biorientados, that exhibit a high gas permeability (breathing capacity), a reduced opacity (good optical properties) and a high modulus of flexion (rigidity), in addition to the unique balance of the properties, impact at reduced temperatures, brightness and good shrinkage or shrinkage properties. Thus, in this way, the aforementioned compositions can be used, in a particular way, for those applications of films or films, which require a breathing capacity, good optical properties and stiffness, such as those consisting of vegetable packaging fresh, rolled and flexible laminated packaging, and clear rotating bags.

Compositions comprising a polycrystalline propylene matrix and a rubber base, formed by an elastomeric copolymer of ethylene with α-olefins, are already known, in the specialized art of the art, and are described, in a particular way, in the European patents EP 170 255, EP 373 660, EP 603 723 and EP 1 135 440, in the international patent application 04/003 073.

Said compositions exhibit high impact resistance and, in the case of European patents EP 373 660, EP 603 723 and EP 1 135 440 and in international patent application 04/003 073, transparency values, which are interesting For many applications. However, the balance of the properties, as a whole, is not yet completely satisfactory, in the total range of possible applications, in view of the high standard standards required by the market. In the case of the international patent WO 04/003 073, a valuable balance of the properties is obtained, but, the balance of the stiffness and the impact, is not completely satisfactory, as regards certain applications, the preferred values of the flexural modulus, they are still unsatisfactory, especially considering the fact that a nucleating agent (Milland) has been used. In the international patent application EO 200 5 121 240, polymer compositions are disclosed, which have an improved balance or balance of impact (Izod), stiffness (flexural modulus) and reduced shrinkage. The compositions disclosed comprise a mixture of polymers, A, which comprise a crystalline propylene homopolymer or copolymer, and an ethylene copolymer, with one or more C4-C10 alpha-olefins. Such a mixture of polymers, has values of MFR (fluidity index), equal to or greater than 10 g / 10 minutes and, in combination with other optional additional components, this is particularly suitable for automobile bumpers and sidebands. Thus, there is still a need and a continuous demand, in terms of the fact of being able to have compositions of this type, with an improved balance or balance of the properties for the target target applications.

An excellent balance of the properties is that which has now been achieved by means of the polyolefin compositions of the present invention, which comprise, in percentage by weight, with reference to the sum of components 1) and 2):

1) 55 -80% of a homopolymer or copolymer of propylene, containing said copolymer, a percentage of up to 15%, of ethylene and / or C4-C10 α-olefin (s).

2) 20-45%, of an ethylene copolymer, with one or more C4-C10 α-olefin (s), containing a percentage of 10 to 40%, by weight, of said α-olefin (s) C4-C10; having the aforementioned compositions, an MFR (fluidity index) value (230 ° C, 2.16 kg) of 1 to 40 g / 10 minutes, a total ethylene content of 20%, or more, a total content of α-olefin (s) C4-C10 of 4.5%, or more, a ratio factor of the total ethylene content, with respect to the total content of α-olefin (s) C4-C10, of 2.3 or more, a total fraction soluble in xylene, at room temperature, of 20%, by weight, or greater, and a flexural modulus, referred to as a reactor grade, of more than 770 MPa.

Particularly preferred features, for the compositions of the present invention, are:

- an intrinsic viscosity of the fraction soluble in xylene, at room temperature, of 2 dl / g or less, in a preferable way, of 1.7 dl / g or less, in a mostly preferable way, of 1.1 a 1.7 dl / g, and even more preferably, from 1.1 to 1.5 dl / g;

-

a content of component 2) (branch) of 25-45%, preferably 25-40%, referring to said percentages, by weight, and referring to the sum of components 1) and 2);

-

a polymer content insoluble in xylene, at room temperature (23 ° C), for component 1), of not less than 90%, in a particular way, of not less than 93%, referring to said percentages , by weight, and referring to the weight of component 1);

-

a total ethylene content, corresponding to a value within a range of 20% to 40%, by weight;

-

a total content of α-olefin (s) C4-C10, corresponding to a value within about

margins ranging from 6% to 15%, by weight;

- Xylene soluble fraction, at room temperature: less than 35%, by weight, preferably 30%, by weight.

The ductile / brittle transition temperature is generally equal to or less than a value of -35 ° C, the lower limit being indicative for a temperature of approximately -60 ° C,

Throughout the present specification, the term "copolymer," as interpreted, also includes polymers, which contain, in addition to the main monomer, more than one class of additional comonomers.

The compositions of the present invention provide, in particular, a combination of high impact resistance (in terms of ductile / fragile transition temperature, and Izod impact resistance), high brightness, high resistance to stress bleaching, and a reduced thermal contraction, measured on plates, and a high gas permeability and a good transparency measured on the films or films.

Preferred polyolefin compositions, for application in films or films, in a particular way, for films or films by casting or biorientados, which exhibit high gas permeability, good optical and stiffness properties, measured on films, are those comprising, in percentage by weight, referred to the sum of components 1) and 2):

1) 55-75%, more preferably, 65-75%,

by weight, of a propylene homopolymer or copolymer,

containing, said copolymer, a percentage of up to 15% ethylene and / or C4-C10 α-olefin (s); Y

2) 24-45%, more preferably, 25-35%, by weight, of an ethylene copolymer, with one or more C4-C10 α-olefin (s), containing 15 to 40% of the cited α-olefin (s) C4-C10; having the aforementioned compositions, MFR values (flow rate) (230 ° C, 2.16 kg) of 1 to 4 g / 10 minutes, a total ethylene content of 20%, or more, a total content of α-olefin (s) C4-C10 of 6% or more, a ratio factor of the total ethylene content with respect to the total content of α-olefin (s) C4-C10 of 2.3 or more, a soluble fraction in total xylene, at room temperature of at least 20%, a flexural modulus of more than 770 MPa. The cited α-olefin (s) C4-C10, which are present, or may be present, as comonomers, in the components and fractions of the compositions of the present invention, are represented by the formula CH2-CHR, wherein , R, is an alkyl radical, linear or branched, with 2-8 carbon atoms, or an aryl radical (in a particular way, phenyl).

Examples of the aforementioned α-olefin (s) C4-C10 are, 1butene, 1-pentene, 1-hexene, 4-methyl-1-pentene and 1-octene. In a particular way, 1-butene is preferred.

The compositions of the present invention can be prepared by sequential polymerization, which comprises at least two sequential stages, wherein components 1) and 2) are prepared in subsequent stages.

separated, operating, at each stage, except in the first stage, in the presence of the polymer formed and the catalyst used in the preceding stage. The catalyst is added,

from

a shape preferable, only in the first stage,

though,

no however, its activity, is such that, is, is

still

active for the whole from the stages

subsequent.

Preferably, component 1) is prepared before component 2).

 Thus, therefore, the present invention is directed, in addition, to a process for the preparation of polyolefin compositions, as previously reported, above, comprising said process, at least two sequential stages of polymerization, each subsequent polymerization being conducted, in the presence of the polymeric material formed in the immediately preceding polymerization reaction, wherein the propylene polymerization step, to the polymer component 1), is carried out in at least one stage, since Then, at least one stage of copolymerization of the mixtures of ethylene with one or more C4-C10 α-olefin (s), to the elastomeric polymer component 2) is performed. The polymerization steps can be carried out in the presence of a specific Ziegler-Natta catalyst.

In accordance with a preferred form of presentation, all the polymerization steps are carried out in the presence of a catalyst comprising a trialkyl aluminum compound, optionally, an electron donor, and a solid catalyst component, comprising a halogen halide-Ti alcoholate, and an electron donor compound, supported on anhydrous magnesium chloride. Catalysts having the aforementioned characteristics, above, are well known in literature corresponding to patents, particularly; Particularly advantageous are the catalysts described in USP.

4,399,054 and in the European patent application EP-A-45

977. Other examples can be found in the patent

USP 4,472,524.

From

a shape preferable, he catalyst from

polymerization,

is a catalyst from Ziegler-Natta, that

It comprises a solid catalyst, which comprises:

a) Mg, Ti and halogen, and an electron donor (internal donor),

b) an alkyl aluminum compound and, optionally (but preferably),

c) one or more electron donor compounds (external donor).

The internal donor is preferably selected from the esters of monocarboxylic or dicarboxylic organic acids, such as benzoates, malonates, phthalates, and certain succinates. These are described in US patent 422 930, in European patent EP 45 977, and international patent applications WO 00/63 261 and WO 01/57 099, for example. Particularly suitable are esters of phthalic acid and succinate acid esters. Alkyl phthalates, such as diisobutyl phthalate, dioctyl phthalate and dibutyl phthalate, and benzylbutyl phthalate are preferred.

Among succinates, succinates selected from among the succinates of the formula (I), given below, are preferred below:

image 1

wherein, the radicals R1 and R2, the same or different or different from each other, are C1-C20 alkyl, C1-C20 alkenyl, C1-C20 cycloalkyl, C1-C20 aryl, C1-C20 arylalkyl, or alkylaryl groups C1-C20, linear or branched, optionally containing heteroatoms; the radicals R3 to R6, the same or different from each other, are hydrogen, or a C1-C20 alkyl, C1C20 alkenyl, C1-C20 cycloalkyl, C1-C20 aryl, C1-C20 arylalkyl, or C1-C20 alkylaryl group , linear or branched, which optionally contain heteroatoms, and radicals R3 to R6, which are attached to the same carbon atom, can be joined together, to form a cycle; with the proviso that, when R3 to R5, are simultaneously hydrogen, R6, is a radical selected from among primary, branched, secondary or tertiary alkyl groups, cycloakyl, aryl, arylalkyl or alkylaryl groups, having from 3 to 20 atoms of carbon;

 or of the formula (II) provided below, below:

image 1

wherein, the radicals R1 and R2, the same or different or different from each other, are C1-C20 alkyl, C1-C20 alkenyl, C1-C20 cycloalkyl, C1-C20 aryl, C1-C20 arylalkyl, or alkylaryl groups C1-C20, linear or branched, optionally containing heteroatoms and, the radical R3, is a linear, alkyl group, having at least four carbon atoms, optionally containing heteroatoms.

The alkyl-Al compounds used as cocatalysts, comprise Al trialkyls, such as trialkyl-Al, triisobutyl-Al, tri-n-butyl-Al, and linear or cyclic alkyl-Al compounds, which contain two or more atoms of Al, united, with respect to each other, by means of atoms of O or N, or groups SO4 or SO3. The alkyl-Al compound is generally used in an amount such that the Al / Ti ratio factor is of a value ranging from 1 to 1000. The external donor (c) may be of the same type, or this may be different from the succinates of the formula (I) or (II). Appropriate external donor compounds include silicone compounds, ethers, esters, such as phthalates, benzoates, succinates, also having a different structure with respect to those of the formula (I) or (II), amines, heterocyclic compounds and, in particular, 2,2,6,6-tetramethylpiperidine, ketones, and 1,3-dieters of the general formula (III):

image 1

wherein, RI and RII, the same or different from each other, are C1-C18 alkyl, C3-C18 cycloalkyl radicals or

RIII

C7-C18 aryl; and RIV, the same or different from each other, are C1-C4 alkyl radicals; or the 1,3-dieters, in which the carbon atom in position 2, belongs to a cyclic or polycyclic structure, formed with a number of up to 5, 6 or 7 carbon atoms, and containing two or three unsaturations.

Ethers of this type are described in published European patent applications EP 361 493 and EP 728

769

Preferred electron donor compounds that can be used as external donors include aromatic silicon compounds, which contain at least one Si-OR link, where R is a hydrocarbon radical. A particularly preferred class of external donor compounds is that corresponding to silicon compounds, of the formula Ra7Rb8Si (OR9) c, where, a and b, are integers from 0 to 2, c is an integer from 1 to 3 and , the sum (a + b + c), is 4; R7, R8, and R9, are C1-C18 hydrocarbon groups, which optionally contain heteroatoms. Particularly preferred are silicon compounds, in which, a is 1, b is 1, c is 2, at least one of R7 and R8 is selected from the alkyl, alkenyl, alkylene, cycloalkyl or aryl groups, branched, with 3-10 carbon atoms, which optionally contain heteroatomno, and R9, is a C1-C10 alkyl group, in a particular, methyl form. Examples of such preferred types of silicon are cyclohexyltrimethoxysilane, tert.-butyltrimethoxysilane, tert.-hexyltrimethoxysilane, cyclohexylmethyldimethoxysilane, 3,3,3-trifluoropropyl-2-ethylpiperidyldimethoxysilane, diphenyldimethoxyethyloxyethyloxyethoxyethyl, methoxymethoxysilane , dicyclopentyldimethoxysilane, 2-ethylpiperidinyl-2-tert.-butyldimethoxysilane, (1,1,1, trifluoro-2-propyl) -methoxydimethoxysilane, and (1,1,1-trifluoro-2-propyl) -2-ethylpiperidinyldimethoxysilane. Additionally, in addition, silicon compounds are also preferred, wherein, a is 0, c is 3, R8 is an alkyl group or

cycloalkyl

branched, that contains optionally

heteroatoms,

Y R9, is methyl. The examples specific

particularly

referrals from compounds from silicon,

they are (tert.-butyl) 2Si (OCH3) 2, (cyclohexyl) (methyl) Si (OCH3) 2, (phenyl) 2Si (OCH3) 2, and (cyclopentyl) 2Si (OCH3) 2.

Preferably, the electron donor compound (c) is used in an amount such that it provides a molar ratio factor between the organoaluminum compound and said electron donor compound (c), corresponding to a value within a range of 0.1 to 500, most preferably 1 to 300 and, in a particular way, 3 to 30.

As explained above, the solid catalyst component further comprises, in addition to the electron donor mentioned above, Ti, Mg and a halogen. In a particular way, the catalyst component comprises a titanium compound, which has at least one Ti-halogen link, and the electron donor compound, cited above, supported on a Mg halide. The magnesium halide is preferably MgCl2, in active form, which is widely known, following patent literature, as a support for Ziegler-Natta catalysts. US patents USP 4,298,718 and USP 4,495,338 were the first to describe the use of these compounds in Ziegler-Natta catalysts. It is known, following these patents, the fact that magnesium dihalides, in

shape

active used how a support or how a co

support,

in components from catalysts for the

polymerization

from olefins, from characterize, through a

X-ray spectrum, in which, the most intense diffraction line that appears in the spectrum of the non-active halide, is diminished in intensity, and is replaced by a halo or halo, whose maximum intensity, moves towards the lower angles , in relation to the most intense line.

Preferred titanium compounds are TiCl4 and

TiCl3; additionally, in addition, the

Ti haloalcoholates of the formula Ti (OR) n-yXy, where, n, is the valence of titanium, and, is a number between 1 and n, X, is halogen, and R, is a hydrocarbon radical, which has from 1 to 10 carbon atoms.

The preparation of the solid catalyst component can be carried out in accordance with various procedures, which are well known, in the specialized art of the art.

In accordance with a preferred process, the solid catalyst component can be prepared by reacting a titanium compound of the formula Ti (OR) n-yXy, wherein, n, is the valence of titanium, and y is a number between 1 and n, preferably, TiCl4, with a magnesium chloride, which is derived from an adduct of the formula MgCl2 · pROH, wherein, p, is a number between 0.1 and 6, preferably, a number that goes from 2 to 3.5 and, R, is a hydrocarbon radical, which has 1-18 carbon atoms. The adduct can be prepared, in an appropriate manner, in spherical form, by mixing alcohol and magnesium chloride, in the presence of inert hydrocarbon, immiscible with the adduct, operating under agitation conditions, at the melting temperature of the adduct ( 100 - 130 ° C). Then, the emulsion is rapidly extinguished, thereby causing solidification of the adduct, in the form of spherical particles.

Examples of spherical adducts prepared in accordance with this procedure are described in US Patents USP 4,399,054 and USP 4,469,648. The adduct thus obtained can be reacted, directly, with the Ti compound, or it can be previously subjected to thermally controlled de-alcoholization (80-130 ° C), so that an adduct is obtained, in which, the number of moles of alcohol, is generally less than 3, being preferably located between 0.1 and 2.5. The reaction with the Ti compound can be carried out by suspending the adduct (de-alcoholic or as such), in cold TiCl 4 (generally, at 0 ° C); The mixture is heated to a temperature of 80-130 ° C, and is maintained at this temperature for a period of 0.5-2 hours. The treatment with TiCl4 can be carried out once or several times. The electron donor compound (s) can be added during treatment with TiCl4.

Regardless of the preparation procedure used, the total amount of electron donor compound (s) is preferably a value such that the molar ratio factor, with respect to MgCl2, is 0.01 to 1 and, more preferably, from 0.05 to 0.5.

The catalysts can be previously contacted, with small amounts of olefin (prepolymerization), keeping the catalyst in suspension, in a hydrocarbon solvent, and polymerizing at corresponding temperatures at a level ranging from room temperature to 60 ° C, producing thus, in this way, a quantity of polymer of 0.5 to 3 times the weight of the catalyst. The operation can also take place in liquid monomer, producing, in this case, an amount of polymer, corresponding to 1000 times the weight of the catalyst.

By using the above-mentioned catalysts, above, the polyolefin compositions are obtained, in the form of spheroidal particles, the particles having an average diameter corresponding to a value within ranges ranging from 250 to 7000 µm, a fluidity of less than 0 seconds, and an apparent density (compacted), corresponding to a value greater than 0.5 g / ml.

The polymerization stages can occur in the liquid phase, in the gas phase, or in the liquid-gas phase. Preferably, polymerization of the polymer component 1) is carried out in a liquid monomer (for example, using liquid propylene, as a diluent), while the copolymerization steps of the elastomeric copolymer component 2) are carried out. in gas phase. Alternatively, all sequential polymerization steps can be performed in the gas phase.

The reaction temperature, in the polymerization step for the preparation of the polymer component 1), and the preparation of the elastomeric copolymer component 2), may be the same or different, and this is, preferably, corresponding to a value comprised within a range of 40 to 100 ° C; more preferably, the reaction temperature is that corresponding to a value within a range of 50 to 80 ° C, in the preparation of the polymer component 1), and that corresponding to a value comprised within about margins ranging from 70 to 100 ° C, for the preparation of the polymer component 2).

The pressure of the polymerization step to prepare the polymer component 1), if carried out in liquid monomer, is corresponding to a value that competes with the vapor pressure of the liquid propylene, at the operating temperature used, and this can be modified, by the vapor pressure of the small amount of inert diluent used, to introduce the catalyst mixture, by overpressure of the optional monomers, and by the hydrogen used as a molecular weight regulator.

The polymerization pressure is, preferably, corresponding to a value within ranges ranging from 33 to 43 bar, if performed in liquid phase, and 5 to 30 bar, if performed in gas phase. . The residence times, relative to the stages, depend on the desired ratio factor between the polymer components 1) and 2), and can be, in a usual way, those corresponding to values within ranges ranging from 15 minutes , up to 8 hours. Conventional molecular weight regulators, known in the art, may be used, such as chain transfer agents, (such as hydrogen or ZnEt2).

The compositions of the present invention can also be obtained by preparing, separately, the aforementioned components 1) and 2), proceeding to operate with the same catalysts, and substantially, under the same polymerization conditions as those set forth above, above (except as regards the fact that, a completely sequential polymerization process will not be carried out, but that the said components will be prepared in separate polymerization stages) and then, mechanically mixing the said components, in ground or softened state. Conventional mixing apparatus, such as helical spindle extruders, in particular double helical spindle extruders, can be used.

The compositions of the present invention may also contain additives commonly employed in the art of the art, such as oxidants, light stabilizers, heat stabilizers, nucleating agents, dyes and fillers.

In a particular way, the addition of nucleating agents, produces a considerable improvement in the important physical-mechanical properties, such as the modulus of elasticity referred to bending, the heat distortion temperature (HDT), the tensile strength in performance, and transparency.

Typical examples of nucleating agents are Na benzoate, talc, and 1,3- and 2,4-dibenzylidensorbitols.

Nucleating agents are added to the composition in accordance with the present invention, preferably, in amounts corresponding to a value within ranges ranging from 0.01% to 2%, by weight, of a more preferable form, from 0.05% to 1%, by weight, with respect to the total weight.

The addition of inorganic fillers, such as talc, calcium carbonate and mineral fibers, also produces an improvement of some mechanical properties, such as the modulus of elasticity referred to bending, and HDT.

The particularities are provided in the examples given below, which are provided to illustrate, without limitation, the present invention.

Examples 1 - 2

In a plant that operates continuously, in accordance with the liquid-gas mixed phase polymerization technique, tests were carried out, under the conditions specified in Table 1.

The polymerization was carried out in the presence of a catalyst system, in a series of two reactors, equipped with devices to transfer the product, from one reactor, to the other immediately following it.

Preparation of the solid catalyst component

Ziegler-Natta catalyst was prepared in accordance with example 5, lines 48-55 of European patent EP 728 769. Triethyl aluminum (TEAL) was used as catalyst, and dichloropentyldimethoxysilane, as an external donor, with the relationship factors indicated in Table 1.

Catalyst system and polymerization treatment

The solid catalyst component, described above, was brought into contact at a temperature of 12 ° C, over a period of 24 minutes, with triethylaluminum (TEAL) and dicyclopentyldimethoxysilane (DCPMS), as the external electron donor component . The ratio factor, by weight, between the TEAL and the solid catalyst component, and the ratio factor, by weight, between the TEAL and the DCPMS, are specified in Table 1.

The catalyst system is then subjected to prepolymerization, proceeding to keep it in suspension, in liquid propylene, at a temperature of 20 ° C, for a period of approximately 5 minutes, before introducing it into the first polymerization reactor.

Polymerization

The polymerization test is conducted continuously, in a series of three reactors, equipped with devices to transfer the product, from one reactor to the other immediately next to it. The first reactor is a liquid phase reactor, and the second reactor is a gas phase reactor with a fluidized bed. The polymer component 1) is prepared in the first reactor, while the polymer component 2) is prepared in the second reactor.

The temperature and pressure are kept constant, during the entire course of the reaction, from the

beginning to the end.

As a molecular weight regulator, it is used

hydrogen.

The gas phase (propylene, ethylene,

and hydrogen), be

continuously analyze, via gas chromatography.

To the

final from the career from test, be discharge the

Powdered matter, and dried under nitrogen flow.

The

data relative to the soluble in Xylene Y he

content of comonomers, in the final polymer compositions, reported in Table 1 and Table 2, are obtained from measurements carried out in the polymers thus obtained, which are stabilized, if necessary.

The polymer particles are then introduced into an extruder, where they are mixed with 1500 ppm Irganox B 215 (consisting of 1 part of Irganox 1010 and 2 parts of Irgafos 168) and 500 ppm of stearate. Ca. The previously cited compound, that is, Irganox 1010, is pentaerythril-tetrakis-2 (3,5-di-tert.-butyl-4-hydroxyphenyl) propanoate, whereas, Iregaphs 168, is the phosphite of tris (2,4-di-tert.butylphenyl), both marketed by the firm Ciba-Geigy. In example 1b, extrusion is conducted without Ca stearate, and with 900 ppm of Na benzoate, to obtain a nucleated composition. The polymer particles are extruded under a nitrogen atmosphere, and with a twin-screw extruder, at a rotation speed of 250 revolutions per minute, and at a

melting temperature of 200-250 ° C.

The data related to the physical-mechanical properties of the final polymer compositions, reported in Table 2, are obtained from measurements made in the extruded polymers in this way.

The data shown in the tables are obtained by using the following test procedures.

-Molar ratio factors of gases

Feeding Determined by gas chromatography.

-Ethylene and 1-butene content of polymers Determined by R.I.

-Fluency index (flux flow rate (MFR)

Determined in accordance with ASTM D 1238, condition L (MFR "L").

-Insoluble and soluble xylene fractions Determined as follows. We proceed to introduce 2.5 g polymer and 250 ml of

Xylene in a glass flask, equipped with a refrigerator and a magnetic stirrer. The temperature rises, over a period of 30 minutes, to the boiling point of the solvent. The clear solution thus obtained is then refluxed and stirred for an additional 30 minutes. The glass flask is then maintained, for a period of 10-15 minutes, at a temperature of 100 ° C, in a thermostatic water bath, at a temperature of 25 ° C, also, during a course of 20 minutes time. The solid thus formed is filtered on a rapid filter paper. 100 ml of the filtered liquid is poured into a previously weighed aluminum container, which is heated on a heating plate, under nitrogen flow, to remove the solvent, by evaporation. The container is then kept, in an oven, at a temperature of 80 ° C, under the action of vacuum, until a constant weight is obtained. We proceed, then,

to

calculate he percentage in weight from polymer soluble in

Xylene, at room temperature.

- Intrinsic viscosity

Determined

in tetrahydronaphthalene, to a temperature

135 ° C

- Flex module

Determined in accordance with ISO 178.

- Izod resistance to impact (with notch) Determined in accordance with ISO 180 / 1A.

-Preparation of plate specimens

Plates were prepared for measurements of D / B and resistance to stress bleaching (tension), with dimensions of 127 x 127 x 127 mm, as follows.

Back pressure (bar): 20 Injection time (s): 3 Maximum injection pressure (MPa): 14 Hydraulic injection pressure (MPa):

6-3 Hydraulic pressure of the first retention (MPa): 4 ± 2 Time of the first retention (s).

3 Hydraulic pressure of the second retention (MPa): 3 ± 2

Second retention time (s).

7

Cooling time (s)

20 Mold temperature (° C):

60

The melting temperature was that corresponding to a value within a range between 220 and 280 ° C.

The opacity measurement plates, 1 mm thick, were prepared by injection molding, with an injection time of 1 second, with a temperature of 230 ° C, and a mold temperature of 40 ° C.

The injection press was a Battenfeld® brand, type BA 500CD, with a closing force of 50 tons. The mold inserted, led to the molding of two plates (55 x 50 x 1 mm, each of them).

-Preparation of casting specimens

Films (films) of a thickness of 50 µm were prepared, proceeding to extrude each polymer composition, in an individual screw spindle extruder, of the Collin brand (ratio factor length / diameter of the screw spindle: 30), at a speed stretching of the film or film, 7 m / minute, and a melting temperature of 210-250 ° C.

-Preparation of BOPP films, for OTR measurement

The polymer composition was compression molded, in a machine of the CARVER type, at a temperature of 230 ° C, to obtain a 1 mm thick and 60 x 60 mm plate, and then it was stretched, using a machine of the TM-Long type, in an oven, at a temperature of 150 ° C, with a stretch ratio factor of 6 x 6, in both directions, to obtain a BOPP film, 30 µm thick.

-Ductile / brittle transition temperature (D / B)

Determined in accordance with the following procedure. Biaxial impact resistance was determined by an impact with a hammer, computerized, automatic.

Circular test specimens were obtained from plates, prepared in the manner described above, proceeding to cut them with a manual, circular punch (38 mm diameter). These were conditioned, for a period of at least 12 hours, at a temperature of 23 ° C, and an RH (relative humidity) of 50 and then placed in a thermostatic bath, at the test temperature , over a period of 1 hour.

The force-time curve was detected, during the impact of a hammer (5.3 kg, hemispherical punch with 1.27 cm in diameter), on the circular specimen, which remained on an annular support. The machine used was of the CEAST brand, type 6758/000, model nº 2.

The transition temperature D / B, means the temperature, at which, a percentage of 50% of the samples, experiences a break or fragile crack, when subjected to the aforementioned impact test test.

Resistance to stress bleaching

The bleaching resistance was determined at room temperature (approximately 23 ° C), holding small discs of the polymer to be tested (diameter 38 mm, thickness 1.5 mm, obtained from prepared plates of the form described above, above), to the impact of a dart that falls from different heights. The diameter of the dart was 1.27 mm and its weight was 263 g. Resistance to stress or tension bleaching is expressed as the diameter of the bleached area (average value of 10 specimens subjected to test tests, for each fall height).

Both the height and width (diameter) of the bleached area are recorded, and reported in Table 2.

-Thermal, longitudinal and transverse contraction

Test specimens, which had dimensions of 100 x 200 x 2.5 mm, were prepared by injection molding, using a molding machine of the "Sandretto Series Sette 190" type (where, 190, means 190 tons of closing force). The main processing parameters are reported below.

-Next pressure: 10 bar

-Injection time + residence time: 30 sec.

- Total cycle time:

55 sec

- Mold temperature:

40 ° C

- Melting temperature:

250 ° C

The

dimensions from the specimens from test, be

measured with a 3C measurement system, supplied with

a "contact probe" (Microval 3D). The contraction, of the difference between the initial dimension of the specimens, after the injection, and after a conditioning period of 48 hours, at a temperature of 23 ° C, and this was expressed as a percentage with respect to the initial dimensions of the specimens. The longitudinal contraction is the contraction or shrinkage, measured in the direction of the injection flow; The transverse contraction is the contraction or shrinkage through the direction of the injection flow.

-Opacity on plate

Determined in accordance with the following procedure. The plates, prepared as described above, were conditioned, for a period of 12 to 48 hours, at a relative humidity of 50 ± 5%, and at a temperature of 23 ± 1 ° C.

The instrument used for the test test was a photometer of the Gardner type, with an opacity measuring device, of the “Haze-meter UX-10” type, equipped with a G.E. 2019, and a filter C. The calibration of the instrument was carried out by carrying out a measurement in the absence of the sample (0% opacity), and a measurement with an intercepted ray of light (100% opacity).

The measurement and computation principle is provided in ASTM-D1003. The opacity measurements were carried out on five plates.

-Gloss on plate

Ten rectangular specimens (55 x 50 x 1 mm) were prepared for each polymer to be tested, by injection molding, using an injection press of the Battenfeld type BA500CD, operating under the

following conditions:

Helical spindle speed

120 rpm

Back pressure

10 bar

Mold Temperature:

40 ° C

Melting temperature:

260 ° C

Injection time:

3 sec

Time of first retention:

5 sec

Second retention time:

5 sec

Cooling time (after the second

retention:

10 sec

The value of the injection pressure should be sufficient, to fill the mold completely, in the period of time mentioned above.

Using a brightness meter, the fraction of luminous flux reflected by the surface of the specimens examined was measured, at an angle of incidence of 60 ° C. The value reported in Table 2 corresponds to the average brightness value, in 10 specimens, for each polymer tested.

The brightness meter used was a Zehntner type photometer set, model ZGM 1020 or 1022, with an incident angle of 60 ° C. The measurement principle is provided in ASTM S 2457. The calibration of the device is performed with a sample, which has a known brightness value.

-Opacity in the movie

Determined on films or films 50 µm thick, of the test composition, prepared as described above, above. The measurement was carried out on a 50 x 50 mm portion, cut from the central area of the film.

The instrument used for the test test was a Gardner type photometer, with a measuring device

opacity, of the type "Haze-meter UX-10",

equipped with a

lamp

from G.E. 2019, Y a filter C. The calibration of the

instrument,

be performed proceeding to wear to cape a

measurement in the absence of the sample (0% opacity), and a measurement with an intercepted beam of light (100% opacity).

-Gloss on the film Determined in the same specimens as for opacity.

The instrument used for the test test was a Zehntner model 1020 photometer for incident measurements. The calibration was carried out by carrying out a measurement at an angle of incidence of 60 °, on black glass, which had a standard brightness of 96.2%, and a measurement at an angle of incidence of 45 °, above black glass that had a standard brightness of 55.4%.

-Oxygen transmission (OTR) Measured on a Mocon OX-TRAN 2/61 type unit,

commercially available in the market, from the origin of the

Mocon Inc., at a temperature of 23 ° C, at a humidity

relative (RH) of 0%, and a percentage of 100% O2.

Comparative Example 1c

The final properties of the composition of comparative example 3, of the international patent application WO 04/003 073, are reported here, for comparative purposes. The composition in accordance with the present invention has a higher stiffness (flexural modulus of elasticity), while exhibiting a valuable balance of impact properties and optical properties, and thermal stability, even in the non-nucleated form from example 1 a.

Comparative Example 2c

The final properties of the hetereophasic propylene copolymer produced by Basell, under the trade name of Moplen 2000 HEXP, are reported in Table 2, for comparative purposes. The Moplen 2000 HEXP, is a hetereophasic copolymer, composed of a matrix of crystalline propylene polymer, and a component of ethylene-propylene rubber (EPR).

Comparative Example 3c

Table 2 also reports the final properties of a mixture consisting of:

40%, by weight, of a commercially available heterephase copolymer commercially composed of approximately 25% of a crystalline propylene polymer matrix, and approximately 75% of ethylene-propylene rubber (EPR) components.

60% crystalline propylene homopolymer, produced by Basell, under the trade name of Moplen HP522H.

The examples demonstrate the fact that, the

5 hetereophasic compositions obtained by mixing propylene polymers, for film or film applications, comprising amounts of ethylene-propylene rubber components, compared with the amounts of ethylene-alpha-olefin rubber component (2) of the

The present invention does not provide the valuable balance of the compositions in accordance with the present invention. Table 1 Polymerization process

Example

one* 2

TEAL / solid catalyst component

Weight ratio factor twenty 12

TEAL / DCPMS

Weight ratio factor 10 8

1st. liquid phase reactor: propylene homopolymer matrix

Polymerization temperature

° C 87 70

Pressure

MPa 38 39

Residence time

minutes 39 61

H2 feed

Mol ppm 4150 910

NFR "L"

g / 10 minutes 3. 4 2

Xylene soluble fraction

% in weigh 1.4 1.7

Branch

% in peo 63 67

Continued table 1

Example

one* 2

1st. liquid phase reactor: ethylene-butene-1 copolymer rubber

Polymerization temperature

° C 85 85

Pressure

Pub twenty 18

Residence time

minutes 47 2. 3

H2 / C2 -

Molar ratio factor 0.309 0.258

C4 - / (C4 - + C2 -)

Molar ratio factor 0.607 0.503

Branch

% in weigh 37 33

Butene-1 in rubber

% in weigh 26 26

Xylene soluble fraction

% in weigh 23.4 23.4

Notes: H2 feed = calculated with respect to the molar flow of propylene; C2 - = ethylene; C3 "= propylene; C4 - = butene 1 * Example 1 not according to the invention

5

10

Table 2

Example and comparative example

one* 2 1 C 2 C 3c

one

**1 B

nuc.

MFR "L"

g / 10 min. fifteen 16 3.3 19.4 18 3

Xylene soluble fraction

% in weigh 23.4 22.9 22.6 - twenty

I.V. of the fraction soluble in Xylene

dl / g 1.41 1.23 1.09 - 1.9

Ethylene content

% in weigh 27.2 24.3 25.4 - 7

1-butene content

% in weigh 9.6 8.5 8.0 -

Elast module referred to bending

MPa 816 995 775 760 997 730

Izod impact resistance

at 23 ° C kJ / m2 12.2 40.04 42.2 37.9 17.5 3. 4

at 0 ° C

kJ / m2 4.8 16.8 23.4 12.0 7.7

at -20 ° C

kJ / m2 4.0 6.2 7.9 8.8 3.1

D / B transition temperature

° C <-50 <-50 -fifty -fifty <-50

Bleaching resistance: Diameter (mm) of bleaching Area due to the impact of a hammer that falls from a height of

76 cm Mmx10 120 130 - - 190

30 cm

Mmx10 90 90 - - 170

20 cm

Mmx10 80 70 - - 140

10 cm

Mmx10 fifty 60 - - 110

5 cm

Mmx10 10 twenty - - 90

Contraction (longitudinal)

% 0.67 0.61 - - 1.24

Contraction (transversal)

% 0.80 0.90 - - 1.40

Table 2 (continued)

Example and comparative example

one* 2 1 C 2 C 3c

one

**1 B

nuc.

Plate opacity (1 mm)

% 48 60 28 23.7 > 90 53.2

Plate brightness (1 mm) at 60 °

% 95 92 106 - 52 91.8

Cast film opacity (50 µm)

% - - 8 - - 13

Glow in cast film (50 µm) at 45 °

% - - 62 - - 39.2

Oxygen transmission rate in

oc / m2 /

bioriented film, (thickness of

day - - 4039 - - 3817

30 µm)

* Example 1, not in accordance with the invention

** 1b nucl. = 1b nucleated

5

10

Claims (5)

1.-Polyolefin compositions comprising, in percentage by weight, with reference to the sum of components 1) and 2): 1) 55 -80% of a homopolymer or copolymer of propylene, containing said copolymer, a percentage of up to 15%, of ethylene and / or C4-C10 α-olefin (s). 2) 20-45%, of an ethylene copolymer, with one or more C4-C10 α-olefin (s), containing a percentage of 10 to 40%, of said C4-C10 α-olefin (s) ; having, said compositions, a value of MFR (fluidity index), measured in accordance with ASTM 1238, at a temperature of 230 ° C, and at 2.16 kg; 1 to 40 g / 10 minutes, a total ethylene content of 20%, or more, a total C4-C10 α-olefin content (s) of 4.5%, or more, a ratio factor of total ethylene content, with respect to the total content of C4-C10 α-olefin (s), of 2.3 or more, a total fraction soluble in xylene, at room temperature, of 20%, by weight, or greater , and a flexural modulus, referred to as a reactor grade, of more than 770 MPa, measured in accordance with the ISO standard 178. 2. The polyolefin compositions of claim 1, wherein the intrinsic viscosity of the soluble fraction, in xylene, at room temperature, is 2 dl / g or less. 3. The polyolefin compositions of claim 1, wherein the copolymer content of ethylene with one or more α-olefin (s) C4-C10, is 25-45%, by weight, of the total composition. 4. The polyolefin compositions of claim 1, which have a ductile / brittle transition temperature, equal to or less than -35 ° C. 5. A process for the preparation of the polyolefin compositions of claim 1, by sequential polymerization, carried out in at least two sequential stages of polymerization, conducting, each Subsequent polymerization, in the presence of the polymeric material formed in the immediately preceding polymerization reaction step. 6. Films comprising the polyolefin compositions of claims 1 or 7.