RU2138514C1 - Propylene homopolymer, fibers, cloth, woven material, film - Google Patents

Abstract

FIELD: polymer materials. SUBSTANCE: propylene homopolymer having in its crystalline structure 20% of stereoblock, index of polydispersity 3.0 to 6.5, and melt flowability index from 0.15 to 1000 g/10 min is prepared by polymerization of propylene monomer in presence of catalyst containing (i) solid catalyst component containing active magnesium halide covered by titanium compound and aromatic acid ester as electron donor, (ii) alkyl aluminum compounds, and (iii) 3,3,3-trifluoropropylmethyl(or ethyl)dimethoxysilane. Fibers manufactured from polymer thus obtained have lower heat-joining temperature and more wide heat joining range. EFFECT: improved quality of fibers. 9 cl, 4 tbl, 2 dwg, 7 ex

Description

 The present invention relates to crystalline propylene homopolymers. More specifically, it relates to crystalline propylene homopolymers, films and fibers obtained from them, and non-woven fabric made from these fibers.

 In a spinning or staple non-woven method, spun or non-combed fibrous webs typically go through a heat-bonding step for processing into fabrics that have the solidity and strength required for various applications. In layered structures where there are two or more layers of nonwoven webs, thermal bonding is a necessary step for bonding the layers together. In these methods, the optimum thermal bonding temperature is selected in order to obtain acceptable tissue characteristics. Therefore, the interval of thermal bonding, the temperature range in which thermal bonding is provided, should also be wide enough for the practical implementation of the method.

When thermo-bonding staple or thermo-bonding fabrics from separate layers, the thermo-bonding temperature is usually the temperature at which maximum tissue strength is achieved, and is also called the optimal thermo-bonding temperature. For traditional homopolymer propylene resins, this temperature range is usually 140-150 ^° C for staple fabrics and 155-165 ^° C for thermally bonded fabrics. However, due to the high crystallinity of traditional homopolymer propylene resins, the thermal bonding interval is very narrow.

 For layered structures, the optimum temperature is usually chosen such that the difference in thermal bonding characteristics between the different types of layers can be balanced, since each layer has different thermal bonding characteristics due to the difference in fiber size or type of polymer used. This distinction is intentional because each layer is designed to fulfill the requirements for various physical properties.

 Take, for example, a layered structure in which the outer layers are intended to give strength and wear resistance, and the inner layers are for barrier properties. Due to differences in property requirements, the size of the fibers used for the inner layers is usually much smaller than the size of the fibers used for the outer layers. In addition, the type of polymer used is different in order to meet the molding requirements.

Due to differences in the type of polymer and the size of the fibers, the inner layers usually require a lower thermal bonding temperature than the outer layer, with a difference of 20 - 20 ^o C. This creates a problem when choosing the optimal thermal bonding temperature for layered structures. For example, if the thermal bonding temperature is set for the outer layer, there are pinholes caused by excessive melting of the fibers in the inner layer, which impair the barrier properties. On the contrary, if the temperature of thermal bonding is set for the inner layer, the laminate will have lower wear resistance due to inadequate thermal bonding of the outer layer.

 Therefore, to obtain high-quality laminates from traditional homopolymer propylene resins, the temperature of thermal bonding must be precisely controlled, which means a very narrow interval of thermal bonding. Since any deviation of the thermal bonding temperature can produce poor-quality fabrics, either due to the presence of pinholes or poor wear resistance, attempts have been made to solve this problem by using polypropylene resins with lower melting points for the outer layer, such as ethylene-propylene random copolymers . In the case of using statistical copolymers, it was hoped that the low-melting nature of the statistical copolymers would reduce the difference in the optimum thermal bonding temperature between the outer and inner layers. However, statistical copolymers tend to reduce the strength of the fabric, especially in the case of a staple-bonded layer, and, in some cases, create molding problems, such as adhesion to the molding equipment, which leads to disruption in the continuity of the molding.

 Therefore, there is a need for a propylene homopolymer from which fibers can be obtained having a lower temperature of thermal bonding and a wider range of thermal bonding.

 It was unexpectedly found that when using a special Ziegler-Natta catalyst on a carrier (substrate) containing 3,3,3-trifluoropropyl- (alkyl) dimethoxysilane, directly during polymerization, a propylene homopolymer is obtained, which has a crystalline structure different from the crystal structure of a traditional homopolymer propylene obtained with other Ziegler-Natta catalysts. The difference is that the crystal structure of the new homopolymer has a much higher stereo block content than the traditional propylene homopolymer, and the new propylene homopolymer has a relatively narrow molecular weight distribution.

 As used herein, the term “stereo block” means the crystal structure of a polymer obtained by a Ziegler-Natta polymerization method that has single defects in a polymerizable monomer unit in a polymer chain, such that the methyl group of the polymerized propylene monomer (defect of the monomer unit) is in a different plane with respect to to the methyl group of other polymerizable propylene monomers. The average number of defects in a monomer unit is 35 per 1000 carbon atoms of the polymer. The number of defects in the monomer unit varies from 20 to 60 per 1000 carbon atoms of the polymer.

 The high-block propylene homopolymers of the present invention provide an alternative to conventional propylene homopolymers used in single-layer applications and random ethylene-propylene copolymers used in layered structures. In single-layer applications, the propylene homopolymers of the invention have a lower thermal bonding temperature and a wider thermal bonding interval than conventional propylene homopolymers. In layered structures, said homopolymers of the invention have melting characteristics similar to commonly used statistical copolymers, and therefore narrow the difference between the thermal bonding temperatures between the layers. However, the high-block propylene homopolymers of the present invention are superior to statistical copolymers in that the reduction in tissue strength is much smaller than that of the statistical copolymer, and the propylene homopolymers of the invention are not sticky, thereby avoiding molding problems associated with the stickiness of the statistical copolymer.

 Accordingly, the present invention provides a propylene homopolymer having a stereo block content of at least 20%, preferably at least 25%, an IP (polydispersity index) value of from 3 to 6.5, preferably from 3.2 to 5.5, and a melt flow index ( MF) from 0.15 to 1000 g / 10 minutes. Another aspect of the invention are fibers obtained from a propylene homopolymer having a stereo block content of at least 20%, preferably at least 25%, an IP value of from 3.0 to 5.0, preferably from 3.2 to 4.0, and a MF from 0 , 15 to 1000 g / 10 minutes.

 Another aspect of this invention is a canvas containing fibers from a homopolymer having a stereo block content of at least 20%, preferably at least 25%, an IP value of from 3.0 to 5.0, preferably from 3.2 to 4.0, and PTR from 0.15 to 1000 g / 10 minutes, and tissue material obtained from it.

 An additional aspect of the present invention are films or sheets of propylene homopolymer having a stereo block content of at least 20%, preferably at least 25%, an IP value of from 4.5 to 6.5, preferably from 5 to 6.5, and MF from 0, 15 to 1000 g / 10 minutes.

 In FIG. 1 is a graph showing a comparison of tensile strength in the transverse direction (CD) of a fabric as a function of thermal bonding temperature for a propylene homopolymer of the present invention and a conventional propylene homopolymer and a random ethylene-propylene copolymer.

 In FIG. 2 is a graph showing a comparison of tissue softness as a function of thermal bonding temperature for the propylene homopolymer of the present invention and a conventional propylene homopolymer.

All parts and percentages in this application, unless otherwise indicated, are given by weight. The ambient temperature or room temperature is approximately 25 ^o C.

The catalyst used in the method for producing the propylene homopolymer of the present invention contains the reaction product: (A) a solid component of a catalyst containing active magnesium halide and a titanium compound supported thereon containing at least one Ti-halogen bond and an electron donor;
(B) A1 -alkyl compounds; and
(C) 3,3,3-trifluoropropyl (alkyl) dimethoxysilane.

 The electron donor compounds used in the solid component of the catalyst (A) include alkyl, aryl and cycloalkyl ethers of aromatic acids, especially benzoic acid or phthalic acid, and their derivatives. Specific examples include benzoate, n-butyl benzoate, methyl p-toluate, methyl p-methoxybenzoate and diisobutyl phthalate. In addition to the above, esters, alkyl or alkaryl ethers having only one ether bond, ketones, mono or polyamines, aldehydes and phosphorus compounds such as phosphines and phosphoramides can also be used as electron donors.

 Obtaining the above catalysts is carried out in various ways.

For example, magnesium halide (anhydrous, i.e. containing less than 1% water), a titanium compound and an electron-donating compound can be mixed in a mill under conditions when the magnesium halide is active. The mixed product is then treated one or more times with an excess of TiCl ₄ at temperatures from 80 to 135 ^° C., and then washed repeatedly with a hydrocarbon such as hexane until all chlorine atoms have disappeared.

According to another method, anhydrous magnesium halide is pre-activated by known methods, and then treated with an excess of TiCl ₄ containing an electron-donating compound in solution. Here again, heat treatment is carried out at temperatures ranging from 80 to 135 ^o C. Optionally, the heat treatment of TiCl _{4 is} repeated, and the solid component is washed with hexane or another hydrocarbon solvent in order to remove all traces of unreacted TiCl ₄ .

According to another method, the adduct MgCl ₂ • nROH, (in particular in the form of spheroidal particles), where H is usually from 1 to 3, and ROH is ethyl alcohol, butyl alcohol or isobutyl alcohol, reacts with an excess of TiCl ₄ containing electron-donating compound in solution. The temperature usually ranges from 80 to 120 ^° C. The solid is then isolated and treated more than once with TiCl ₄ , after which it is released and washed with hydrocarbon until all chlorine ions disappear.

According to another method, magnesium alcoholates and chloral alcoholates, in particular chloral alcoholates obtained in accordance with the method described in US Pat. No. 4,220,554, react with an excess of TiCl ₄ containing an electron-donor compound in solution under the reaction conditions described above.

 In the solid catalyst component (A), a titanium compound, expressed as Ti, is usually present in an amount of from 0.5 to 10% by weight. The amount of electron-donor compound that remains fixed on the solid component (internal donor) is usually 5 to 20% in moles with respect to the magnesium dihalo.

Suitable examples of a titanium compound having at least one Ti-halogen bond are Ti-tetrahaloids, in particular TiCl ₄ . However, titanium alkoxyhaloids may also be used.

 The above reactions cause the formation of magnesium halide in active form. In addition to these reactions, other reactions are known from the literature that cause the formation of activated magnesium halogen from magnesium compounds other than halogens, such as, for example, magnesium carboxylates.

The active form of magnesium halides in the components of the catalyst (A) can be determined by the fact that in the X-ray spectrum of the catalyst component there is no main reflection of the intensity that occurs in the spectrum of inactive magnesium chloride (having a specific surface area of less than 3 m ² / g), but there is a halo with maximum intensity, shifted to the position of the main reflection of the intensity of the inactivated magnesium dihalo, or by the fact that the main reflection of the intensity shows the width at 1/2 height not m less than 30% more than for the main reflection of the intensity that is present in the spectrum of inactive magnesium chloride.

 The most active forms are those in which the above halo appears on the x-ray spectrum of the component.

Al-алкил-соединения (В), используемые в качестве сокатализаторов, содержат Al-триалкилы, такие как Al-триэтил, Al-изобутил, Al-три-H-бутил, а линейные или циклические Al-алкил-соединения, содержащие два или более Al-атомов, соединенных через O- или V-атомы, или SO₄- и SO₃-группы.Among magnesium halides, magnesium chloride is the preferred compound. In the case of the most active forms of magnesium chloride, the X-ray spectrum of the catalyst component shows a halo instead of the reflection that appears in the spectrum of inactive chloride at a distance

Al-alkyl compounds (B) used as cocatalysts contain Al-trialkyls such as Al-triethyl, Al-isobutyl, Al-tri-H-butyl, and linear or cyclic Al-alkyl compounds containing two or more Al atoms connected via O- or V-atoms, or SO ₄ and SO ₃ groups.

Examples of these compounds are: (C ₂ H ₅ ) ₂ Al-O-Al (C ₂ H ₅ ) ₂ ; (C ₂ H ₅ ) ₂ Al-N (C ₆ H ₅ ) - AlC ₂ H ₅ ) ₂ ; (C ₂ H ₅ ) ₂ Al-SO ₂ -Al (C ₂ H ₅ ) ₂ ; CH ₃ [(CH ₃ ) -AI-O-] _n Al (CH ₃ ) ₂ ; [(CH) AI-O-] _n , where n is a number from 1 to 20.

 The Al-alkyl compound is usually used in amounts such that the Al / Ti ratio varies from 1 to 1000.

 The alkyl of 3,3,3-trifluoropropyl (alkal) dimethoxysilane component (C) may be either methyl or ethyl, and preferably methyl.

 The catalyst, i.e., components (A), (B) and (C), can be introduced into the polymerization reactor by separate means practically simultaneously, regardless of whether the polymer is already in the reactor, or sequentially if the monomer is introduced into the polymerization reactor later. Preferably, components (A) and (B) are pre-mixed, then said pre-mixture is contacted with component (C) prior to polymerization for 3 to about 10 minutes at room temperature.

 Propylene monomer can be introduced into the polymerization reactor before, simultaneously with or after the introduction of the catalyst.

 If necessary, hydrogen can be added as a regulator of the degree of polymerization to reduce the molecular weight of the polymer.

 The polymerization can be carried out by a suspension, liquid-phase or gas-phase method or by combining liquid-phase and gas-phase methods using separate reactors that can operate periodically or continuously.

The polymerization is usually carried out at a temperature of 40-90 ^o C at atmospheric pressure or elevated pressure.

The catalysts can pre-interact with small amounts of propylene monomer (prepolymerization), maintaining the catalyst in suspension in a hydrocarbon solvent and polymerizing at a temperature of 60 ^o C or lower for a time sufficient to obtain a polymer in an amount of 0.5 to 3 times the mass of the catalyst .

 The prepolymerization can be performed in liquid or gaseous monomer to obtain in this case a polymer in an amount up to 1000 times the mass of the catalyst.

 The following examples are provided to illustrate the invention and are not intended to limit the scope of the invention.

где G' - модуль накопления, G'' - низкий модуль.Unless otherwise indicated, the following studies are used to determine the characteristics of the propylene homopolymers of the present invention, fabrics obtained from them, and comparative fabric materials:
Properties - Method
Melt Flow Index (MFI), g / 10 min - ASTM-D 1238 Mode 1
Intrinsic viscosity (XB = JV) - Determined in tetrahydronaphthalene at 135 ^o C
Determination of tensile strength - ASTM-D 1682 and ASTM-D 1776
Determination of Softness - ASTM-D 1388-64
Polydispersity Index (PI = PJ) - Determination of the molecular weight distribution in a Mw / Mn polymer
To determine the IP value, modular separation at a low modulus value, for example 500 Pa, is determined at a temperature of 200 ^o C using a parallel-plate rheometer model RMS -800, supplied by PHEOMETRJCS (USA), when operating with an oscilloscope frequency that increases from 0, 1 to 100 rad / s. From the value of the modular separation of IP can be obtained using the following equation:
IP = 54.6 (separation modulus) ^-1.76

where G 'is the storage modulus, G''is the low modulus.

 The method of fractional leaching with increasing temperature (MPVPT = TREF).

This technique is a method for studying the crystal structure of a polymer. The technique uses xylene as a solvent to dissolve the crystalline structure of the polymer and determines the dissolved amount when the temperature rises above room temperature to the point where the entire polymer dissolves. The part dissolved at room temperature is designated as the atactic part, dissolved in the range from room temperature to 100 ^o C, is designated as a stereo block, and the part remaining above 100 ^o C is called isotactic.

The percentage of insoluble in xylene -2.5 g of the polymer is dissolved in 250 ml of xylene at 135 ^o C with stirring. After 20 minutes, the solution is cooled to 25 ^o C, with stirring, and then precipitated for 30 minutes.

The precipitate is filtered off with filter paper, the solution is evaporated in a stream of nitrogen, and the precipitate is dried under vacuum at 80 ^o C until a constant weight is reached, then the percentage by weight of the polymer dissolved in xylene at room temperature is calculated. The percentage by weight of the polymer, insoluble in xylene at room temperature, is taken as an indicator of the stereoregularity of the polymer. The value obtained in this way corresponds practically to the stereoregularity index determined by extraction in boiling n-heptane, which, when determined, corresponds to the stereoregularity index of polypropylene. Melting point (T _PL - M. R.) - is determined by the method of DSC (differential scanning calorimetry). The samples are pre-melted with increasing temperature to 200 ^o C and maintained at this temperature for 5 minutes. The samples are then cooled to 50 ^° C. and then reheated until completely melted. Heating and cooling are carried out at a rate of 10 ^o C per minute. The melting point indicated here refers to the upper peak of the DSC curve obtained in the second melting process.

Example 1
Obtaining a solid catalyst component
In a 500 ml reactor equipped with a porous diaphragm, 225 ml of TiCl _{4 are} introduced at 0 ^° C. With stirring for 15 minutes, 10.3 g of microspheroidal MgCl ₂ / 2.1 C ₂ H ₅ OH are added. At the end of the addition, the temperature is brought to 70 ^° C., 9 mmol of diisobutyl phthalate is added, the contents are heated to 100 ^° C. and maintained at this temperature for 2 hours, after which TiCl _{4 is} filtered off. Then 200 ml of TiCl _{4 are} added and the contents are reacted at 120 ^° C. for 1 hour, after which they are filtered and washed at 60 ^° C. with anhydrous heptane until the chlorine ions completely disappear from the filtrate.

 Analysis of the solid component shows that the solid component of the catalyst contains 16.7 wt.% Mg, 2.35 wt.% Ti and 7.2 wt.% Diisobutyl phthalate.

The microspheroidal adduct MgCl ₂ / 2,1 C ₂ H ₅ OH is obtained as follows:
48 g of anhydrous MgCl ₂ , 77 g of anhydrous C ₂ H ₅ OH and 810 g of kerosene are introduced in an inert gas atmosphere at room temperature into a 2 liter autoclave equipped with a turbine stirrer and immersion tube. The contents are heated to 120 ^° C. with stirring, and an adduct forms between MgCl ₂ and the alcohol, which melts and remains mixed with the dispersant. Inside the autoclave, a nitrogen pressure of 15 atmospheres is maintained. The submersible tube of the autoclave is heated to 120 ^o C using a heating jacket and has an inner diameter of 1 mm and a length of 3 m from end to end of the heating jacket.

 The mixture circulates through the tube at a speed of 7 m / s.

The dispersion is collected in a 5-liter flask with stirring, and this flask contains 2.5 l of kerosene and is cooled externally with a jacket at an initial temperature of 40 ^o C.

The final temperature of the emulsion is 0 ^° C. The spherical solid product constituting the dispersed phase of the emulsion is separated by precipitation and filtration, then washed with heptane and dried.

All of the above operations are performed in an inert gas atmosphere. 130 g of the adduct MgCl ₂ / 2,1 C ₂ H ₅ OH is obtained in the form of solid spherical particles with a maximum diameter of less than 50 microns. The product is dealcoholized at temperatures that gradually increase from 50 to 100 ^o C in a stream of nitrogen until the alcohol content reaches 2.1 mol per mole of MgCl ₂ .

Propylene Polymerization
The polymerization is carried out continuously in a number of circulation reactors equipped with devices for transporting the product exiting the reactor immediately preceding to the next reactor.

 The content of hydrogen and monomer in the liquid phase is continuously analyzed, and they are supplied in such a way that the required concentration is kept constant.

 The catalytic mixture is obtained by contacting a mixture of triethylaluminum (TEA1) and 3,3,3-trifluoropropyl (methyl) dimethoxysilane (TEA1 / silane weight ratio is shown in Table A) with the solid catalyst component obtained above in a container for about 13-15 minutes.

 The catalyst is then transferred to another reactor where polymerisation in the liquid phase takes place to form fraction (A).

 The product from the above reactor is fed to the second reactor in the liquid phase to form fraction (B).

 Operating conditions for the preparation and physical properties of the obtained propylene homopolymer are given below in Table A.

Table a
TEA1 / silane, mass. - 2,3
First reactor
Temperature, ^o C - 70
Pressure, bar - 34
Duration of stay, min - 107
With ₃ feeds, kg / h - 350
The resulting polymer, kg / h - 153
PTR, g / 10 min - 0.8
H.V., dl / g - 3.04
Second reactor
Temperature, ^o C - 65
Pressure, bar - 34
Time of stay, min - 75
H ₂ , g / h - 20.5
C ₃ feeds, kg / h - 150
The resulting polymer, kg / h - 200
PTR, g / 10 min - 3.9
H.V., long.d - 2.34
Final product
The total polymer yield, kg - 1400
PTR, g / 10 min - 3.8
H.V., dl / g - 2.62
Mp., ^O C - 161
IP - 4.7
Insoluble in xylene,% - 96.1
Example 2
The flocculent material of Example 1 is mixed with 1000 ppm of stabilizer Irganox 1076, 550 ppm of calcium stearate and Lupersol 101 using conventional extrusion and granulation to obtain a MFI of 38 g / 10 min.

Comparative Example 1
A propylene homopolymer of the pF-301 trademark in the form of granules having a TPR of 38 g / 10 min and a PI of 2.5.

 From the data given in table 1 (see the end of the description), it can be seen that the homopolymer of the present invention has a much higher stereo block content than traditional propylene homopolymer.

Propylene homopolymers are obtained in accordance with the procedure of Example 1, except that a solid catalyst component with a granular MgCl ₂ substrate is used instead of the MgCl ₂ / alcohol adduct and 3,3,3-trifluoropropyl (methyl) -dimethoxysilane and other donors are used, listed in table 2 as external donors. The crystal structure of the obtained propylene homopolymers is analyzed for the content of atactic, stereoblock, and isotactic components. The results are shown in table 2 (see the end of the description).

 It can be seen that the crystal structure of propylene homopolymer obtained with 3,3,3-trifluoropropyl (methyl) dimethoxysilane as an external donor has a much higher stereoblock content than the crystal structures of homopolymers obtained using other external donors.

Reference Example 2
The statistical copolymer of ethylene with propylene of the SA-849 trademark, containing 3% ethylene and having an MFI of 10 to 38 g / 10 min, was tested according to the procedure of Example 2. The statistical copolymer has a stereo block content of 94.2%, an isotactic content of 2.5%, and atactic content of 3.3%.

Example 3
The propylene homopolymer of Example 2 and Comparative Examples 1 and 2 are processed into melt non-woven material. The granular product is extruded to a traditional molding equipment to produce nonwoven material from a melt, where the molten polymer is converted into fibers, which are laid on a tape to form a canvas and then thermally bonded to a calender at 5 different thermal bonding temperatures.

Upon receipt of the nonwoven material from the melt by the spinneret method, the following conditions are used:
Transmission Speed - 0.35 g / min / hole
Extrusion temperature - 210 ^o C
Belt speed - 27 m / min
Base fabric weight - 40 g / m ²
Fiber Size - 28 microns
Thermal bonding temperature - 104, 116, 127, 138, 149 ^o C
The strength of the resulting tissues is determined, the results are shown in FIG. 1. Three polymers are compared: the propylene homopolymer from example 2, the traditional homopolymer from comparative example 1, and the traditional random ethylene-propylene copolymer from comparative example 2.

The tensile strength in the transverse direction (CD) is one of the most important strength requirements for nonwoven materials obtained from the melt spunbond. When the propylene homopolymer of the present invention is compared with a conventional propylene homopolymer, it can be seen that the propylene homopolymer of the invention has a lower optimum thermal bonding temperature than the traditional propylene homopolymer, 127 ^° C. versus 138 ^° C. The propylene homopolymer of the present invention also has a wider thermal bonding range, t .e. the fusing curve is smoother near the optimum fusing temperature compared to the traditional propylene homopolymer.

 Compared to the traditional random ethylene-propylene copolymer of comparative example 2, the propylene homopolymer of the present invention provides fabrics with higher tensile strength, although both polymers have lower strength than the traditional propylene homopolymer. In addition, the propylene homopolymer of the invention provides a wider thermal bonding interval compared to the conventional random copolymer used.

Example 4
The fabrics obtained in Example 3 are tested for softness, which is inversely proportional to the length of the bend. The results are shown in FIG. 2.

It can be seen that the homopolymer of the present invention is softer at lower thermal bonding temperatures, while the traditional homopolymer of Comparative Example 1 is softer at higher temperatures. At optimum thermal bonding temperatures of 127 ^° C for the homopolymer of the present invention used here and 138 ^° C for the traditional propylene homopolymer, the softness of the fabric made from the homopolymer of the present invention is comparable to the softness of the fabric of the traditional propylene homopolymer.

Example 5
An ultrahigh MFI propylene homopolymer is obtained in accordance with the procedure of Example 1, except that the polymerization temperature is 60 ^° C instead of 65 ^° C, and the homopolymer has the following characteristics: MFI 278 g / 10 min, IP 4.2, stereo block content 25 , 2%, atactic content of 3.8% and isotactic content of 71.0%.

 The resulting polymer is an emulsion stabilized with 1000 ppm stabilizer Crganox 1076 and 500 ppm calcium stearate and 500 ppm Lupersol 101 to give a MFI of 600 g / 10 min.

Reference Example 3
Serially supplied by HIMONT (USA), an HH-442H propylene homopolymer with an ultra-high MFI, having an MFI of 800 g / 10 min, a stereo block content of 16.5%, an atactic content of 3.3%, and an isotactic content of 80.1%.

Example 6
The ultra-high MFI propylene homopolymer from Example 5 and from Comparative Example 3 are processed into canvases in an aerodynamic manner. The operating conditions used for this are as follows:
Transmission rate - 0.4 g / min / hole
Melt temperature - 254 ^o C and 232 ^o C
Base fabric weight - 34 g / m ²
Air temperature - 285 ^o C
The fabrics are tested for softness, machine bending length (MD) in cm and transverse bending length (CD) in cm are given in Table 3 (see end of description).

 The softness of the fabric made from the propylene homopolymer of the present invention is comparable to the softness of the fabric from the traditional propylene homopolymer.

Example 7
This example illustrates a film material made from the propylene homopolymer of the present invention in granular form, having a MFI of 2.75 g / 10 min, PI 5 and 4.3% soluble in xylene, and a film from a traditional propylene homopolymer, commercially available from HIMONT ( Canada) in granular form, having a MFI of 2.0 g / 10 min, PI 5.3 and 4.6% soluble in xylene.

The sheet product is extruded on a 1 1/2 inch Killion extruder under the following conditions:
Zone N 1 - 450 ^o F (232.2 ^o C)
Zone N 2 - 480 ^o F (248.8 ^o C)
Zone N 3 - 480 ^o F (248.8 ^o C)
Zone N 4 - 480 ^o F (248.8 ^o C)
Sprue - 480 ^o F (248.8 ^o C)
Die No. 1 - 480 ^o F (248.8 ^o C)
Die N 2 - 480 ^o F (248.8 ^o C)
Speed - 97 rpm
The temperature of the cooling roll - 120-125 ^o F (49 ^o C - 52 ^o C)
The speed of rotation of the cooling roll is 6.8 ft / min (2.07 m / min).

Sample sheets of a propylene homopolymer of the present invention and a conventional propylene homopolymer stretched in the machine direction of the exhaust apparatus at 3 inch / s, 35 lb / ⁱⁿ² force (2.46 K / cm ² and simultaneous 6x drawing.

 Measurements of stress versus orientation at the yield point in the machine direction are performed at different temperatures on 2 films.

 The results are shown in table 4.

 The propylene homopolymer of the present invention can be used for a spunbond non-woven layer in the FAF (spunbond-aerodynamic-spunbond) layered non-woven structure and in the production of other non-woven materials, thermally bonded staple fibers, as well as films, sheets, spunbond fabrics to fabrics obtained by the aerodynamic method.

 Other characteristics, advantages, and variations of the invention described herein will be readily apparent to those skilled in the art from the above description. From this point of view, while individual examples of the invention are described in sufficient detail, variations and modifications of these examples can be made without departing from the spirit and scope of the invention, as set forth in the description and reflected in the claims.

Claims (9)

1. A propylene homopolymer, characterized in that it has a stereo block content of at least 20% in its crystal structure, a polydispersity index value of 3.0-6.5 and a melt flow rate of 0.15-1000 g / 10 min, which is obtained by polymerization of a monomer propylene in the presence of a catalyst containing the reaction product: (A) a solid catalyst component containing an active magnesium halide and a titanium compound supported thereon having at least one Ti-halogen bond and an aromatic acid ester as a donor electrons; (B) Al-alkyl compounds; (C) 3,3,3-trifluoropropyl (C _1-2 alkyl) dimethoxysilane.  2. The propylene homopolymer according to claim 1, characterized in that it has a stereo block content of at least 25%, a polydispersity index value of 3.2 - 5.5.  3. A fiber obtained from a propylene homopolymer, characterized in that the propylene homopolymer has a stereo block content of at least 20% in its crystal structure, a polydispersity index value of 3.0 - 5.0 and a melt flow rate of 0.15 - 1000 g / 10 min  4. A canvas containing fibers obtained from a propylene homopolymer, characterized in that the propylene homopolymer has a stereo block content of at least 20% in its crystal structure, a polydispersity index value of 3.0 - 5.0 and a melt flow rate of 0.15 - 1000 g / 10 min.  5. The canvas according to claim 4, characterized in that it is a non-woven canvas obtained by spinning a non-woven material from a melt.  6. The canvas according to claim 4, characterized in that it is a non-woven canvas obtained by the method of blasting from the melt.  7. Fabric material, characterized in that it is obtained from the canvas according to claim 5.  8. A fabric material, characterized in that it is obtained from the canvas according to claim 6.  9. A film from a propylene homopolymer, characterized in that the propylene homopolymer has a stereo block content of at least 20% in its crystal structure, a polydispersity index of 4.5-6.5 and a melt flow rate of 0.15-1000 g / 10 min.

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