JP5564337B2 - Crystalline propylene polymer, process for producing the same, and resin composition containing the same - Google Patents

Description

  The present invention relates to a crystalline propylene polymer having very high rigidity and heat resistance, no fish eye, and good moldability, a process for producing the same, and a resin composition containing the same. Crystalline propylene polymer with excellent drawability, excellent drawability and deep drawability, and suitable for the production of molded articles by thermoforming methods such as vacuum forming method or pressure forming method, including the manufacturing method and the same The present invention relates to a resin composition.

Crystalline polypropylene is relatively inexpensive, has excellent mechanical strength, and has excellent properties such as a high temperature that can be used, and is therefore used in various fields today. Further, depending on the application, higher mechanical strength is required, so that improvements in catalysts, polymerization additives, and the like have been made in the past, and attempts have been made to produce polypropylene with high stereoregularity and high rigidity.
However, in the improved catalyst with high stereoregularity, the molecular weight distribution tends to be narrow, the elastic properties at the time of melting are lowered, and the productivity at the time of molding is lowered, particularly vacuum forming and pressure forming. In the case of thermoforming, etc., a drawdown problem may occur.
In order to solve such a problem, even with an improved catalyst with high stereoregularity, a catalyst that does not narrow the molecular weight distribution of polypropylene has been developed, but it has a sufficient effect to compensate for the decrease in elastic properties. There was a problem that it could not be obtained, accompanied by a decrease in mechanical strength, and increased in cost.
Conventionally, it has been proposed to mix a high molecular weight component and a low molecular weight component of polypropylene with high stereoregularity off-line or in a polymerization blend. However, in this case, it is necessary to pay attention to the fact that the high molecular weight component is difficult to uniformly disperse, and the molded product is rough and fish eyes are generated.

  When separately polymerized high molecular weight components and low molecular weight components are mixed outside the polymerization process (off-line), the degree of mixing of both components is poor, and fish eyes are likely to occur. For this reason, various methods have been proposed in which both components are alternately produced in the polymerization process of propylene and improved by a so-called polymerization blend technique.

For example, a method for producing a low molecular weight component after producing a high molecular weight component is known (see, for example, Patent Documents 1 to 3).
However, this method generally tends to generate fish eyes. The reason is that when the high molecular weight component is produced, the catalyst may be partially deactivated, and in a certain portion, the low molecular weight component does not exist and only the high molecular weight component exists. In this case, a non-uniform mixing state is generated in a part thereof as in the case of off-line mixing. That is, the deactivation of the catalyst in the middle of the polymerization results in a reduction in the polymerization blend effect.
In addition, if the difference in molecular weight between the high molecular weight component and the low molecular weight component is reduced in order to suppress the generation of fish eyes, it is natural that sufficient melt elasticity cannot be obtained and the moldability cannot be improved.

Therefore, according to the knowledge of the present inventors in the conventional catalyst, fish eyes were not generated in the multistage polymerization process, and sufficient melt elasticity could not be obtained. In particular, in the multistage polymerization process comprising one or more bulk polymerization steps and one or more gas phase polymerization steps, the above problem was significant.
Further, in the improvement of rigidity, a nucleating agent is used as an additive in order to obtain a polypropylene having higher rigidity, but there has been a problem that the amount of use thereof has heretofore been large and the manufacturing cost becomes high.

JP-A-57-185304 Japanese Patent Laid-Open No. 02-232207 JP 08-157522 A

  The object of the present invention is, in view of the above-mentioned problems of the prior art, the conventional propylene polymer could not be achieved at all, the rigidity and heat resistance are very high, the moldability is further improved, there is no fish eye, It is an object of the present invention to provide a crystalline propylene polymer having significantly improved elastic properties at the time of melting, a method for producing the same, and a resin composition containing the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that crystalline polypropylene satisfying predetermined characteristics has good rigidity, heat resistance, moldability, and elastic properties, as well as fish eyes. In addition, when a specific catalyst with high stereoregularity is used to produce the catalyst by multistage polymerization, the catalyst is also characterized by hydrogen responsiveness. Thus, the crystalline propylene polymer can easily give a molecular weight difference between a high molecular weight component and a low molecular weight component, and can give elastic properties by performing a polymerization blend thereof. From these findings, the present invention has been completed.

That is, according to the first invention of the present invention, there is provided a method for producing a crystalline propylene polymer satisfying the following characteristics (a) to (c), including a bulk polymerization step and a gas phase polymerization step. Polymer MFR (MFR1) and crystalline propylene polymer produced by multistage polymerization of two or more stages, the polymer melt flow rate (MFR) obtained in each stage is successively reduced, and the first stage reaction vessel is produced. A method for producing a crystalline propylene polymer is provided in which the MFR ratio of MFR to MFR (MFR2) is represented by the following formula:
MFR1 / MFR2> 4.0
(A) Temperature at which the 40 ° C. soluble fraction (40 ° C. sol.) Is 1% by weight or less and the amount of the eluted component is the highest in the measurement of temperature rising elution fractionation (TREF) using orthodichlorobenzene as a solvent (Tp) is in the range of 113 to 125 ° C.
(B) The value of the storage elastic modulus at the intersection Gc between the frequency ω dependency curve G ′ (ω) of the storage elastic modulus and the frequency ω dependency curve G ″ (ω) of the loss elastic modulus by dynamic viscoelasticity measurement ( unit: when the 10 ^five times the reciprocal of Pa) was the PI, is PI of 4.0 or more.
(C) The melt flow rate (MFR2) measured according to JIS K7210 (230 ° C., 2.16 kg load) is 0.2 to 0.8 g / 10 min.

Further, according to the second aspect of the present invention, Oite the first invention, a manufacturing method of a crystalline propylene polymer which is characterized in that produced by multistage polymerization of four or more stages are provided.

According to the third invention of the present invention, in the first or second invention, the propylene containing the solid catalyst component (A) containing titanium, magnesium and halogen as essential components and the organoaluminum component (B). There is provided a method for producing a crystalline propylene polymer, characterized by using a polymerization catalyst.
Furthermore, according to a fourth invention of the present invention, in the third invention, the propylene polymerization catalyst further comprises the following polymerization additive (C): Is provided.
Polymerization additive (C): an organosilicon compound containing two or more Si—OR ¹ bonds (provided that R ¹ is a hydrocarbon group having 1 to 8 carbon atoms)

According to a fifth aspect of the present invention, in the third or fourth aspect , the solid catalyst component (A) is brought into contact with the following components (i), (ii), (iii) and (iv): A method for producing a crystalline propylene polymer is provided.
(I) Solid component containing titanium, magnesium and halogen as essential components (ii) Organosilicon compound containing two or more Si—OR ¹ bonds (where R ¹ is a hydrocarbon residue having 1 to 8 carbon atoms) is there.)
(Iii) Vinylsilane compound (iv) Organometallic compound of periodic group I-III metal

The crystalline propylene polymer of the present invention has a specific flexural modulus, dynamic viscoelasticity, and MFR, has very high rigidity and heat resistance, has no fish eye, and has good moldability.
The crystalline propylene polymer production method of the present invention can produce the crystalline propylene polymer easily and under high polymerization activity.

The frequency dependence curve G ′ (ω) and the frequency dependence curve G ″ are obtained by plotting the viscoelasticity of polypropylene with the sinusoidal frequency ω on the horizontal axis and the measured storage elastic modulus and loss elastic modulus plotted on the vertical axis. It is a figure which shows the relationship of ((omega)). It is a general figure which shows the relationship between the amount of sagging of a polypropylene-type thermoforming sheet | seat in heating resistance evaluation, and heating time.

The crystalline propylene polymer of the present invention is characterized by satisfying the characteristics (a) to (c) described in detail below, and produced by multistage polymerization using a specific catalyst having high stereoregularity. Is done.
Hereinafter, the present invention will be described in detail for each item.

1. Crystalline Propylene Polymer The present invention is a crystalline propylene polymer that satisfies the following characteristics (a) to (c).
(A) Temperature at which the 40 ° C. soluble fraction (40 ° C. sol.) Is 1% by weight or less and the amount of the eluted component is the highest in the measurement of temperature rising elution fractionation (TREF) using orthodichlorobenzene as a solvent (Tp) is in the range of 113 to 125 ° C.
(B) The value of the storage elastic modulus at the intersection Gc between the frequency ω dependency curve G ′ (ω) of the storage elastic modulus and the frequency ω dependency curve G ″ (ω) of the loss elastic modulus by dynamic viscoelasticity measurement ( unit: when the 10 ^five times the reciprocal of Pa) was the PI, is PI of 4.0 or more.
(C) The melt flow rate (MFR2) measured according to JIS K7210 (230 ° C., 2.16 kg load) is 0.2 to 0.8 g / 10 min.

  The crystalline propylene polymer of the present invention has a temperature of 40 ° C. sol. In the measurement of temperature rising elution fractionation (TREF) using orthodichlorobenzene as a solvent. Is 1% by weight or less, preferably 0.8% by weight or less, and more preferably 0.5% by weight or less. Furthermore, Tp is the range of 113-125 degreeC, the range of 115-120 degreeC is preferable, More preferably, it is the range of 116-119 degreeC. 40 ° C. sol. Is 1% by weight or more and Tp is less than 113 ° C., it is inconvenient because the required mechanical properties of the molded product cannot be obtained.

The details of the measurement method of the eluted component by temperature rising elution fractionation (TREF) used in the present invention are as follows.
A sample is dissolved in orthodichlorobenzene at 140 ° C. to obtain a solution. This is introduced into a 140 ° C. TREF column, cooled to 100 ° C. at a rate of 8 ° C./min, and then cooled to 40 ° C. at a rate of 4 ° C./min, and held for 10 minutes. Thereafter, orthodichlorobenzene as a solvent is allowed to flow through the column at a flow rate of 1 ml / min, and then the column is linearly heated to 140 ° C. at a temperature rising rate of 100 ° C./hour to obtain an elution curve.
Column size: 4.3mmφ × 150mm
Column packing material: 100 μm surface inactive treated glass beads Solvent: Orthodichlorobenzene Sample concentration: 5 mg / ml
Sample injection volume: 0.1 ml
Solvent flow rate: 1 ml / min Detector: Fixed wavelength infrared detector, manufactured by FOXBORO, MIRAN, 1A
Measurement wavelength: 3.42 μm

The crystalline propylene polymer of the present invention has a melt flow rate measured based on JIS K7210 (230 ° C., 2.16 kg load) in the range of 0.2 to 0.8 g / 10 min. 0.3 to 0.7 g / 10 min is preferable, and 0.3 to 0.6 g / 10 min is more preferable.
When the melt flow rate is less than 0.2 g / 10 min, the decrease in flowability causes a decrease in molding processability. On the other hand, when the melt flow rate exceeds 0.8 g / 10 min, the decrease in melt tension causes a decrease in molding processability. It is inconvenient.

Furthermore, the crystalline propylene polymer of the present invention has a frequency ω-dependent curve G ′ (ω) of storage elastic modulus measured by dynamic viscoelasticity and a frequency ω-dependent curve G ″ (ω) of loss elastic modulus. intersection value of the storage modulus Gc (unit: Pa) when the ¹⁰⁵ times the reciprocal of the PI, PI is not less than 4.0, preferably not less than 4.2, more preferably 4.4 or more. A PI of less than 4.0 is disadvantageous because it causes a decrease in moldability. PI is preferably 6.0 or less, and more preferably 4.8 or less.

  In the present invention, the dynamic viscoelasticity measurement refers to measuring the dynamic viscoelasticity of the polymer melt, and can be measured with an apparatus for measuring ordinary dynamic viscoelasticity. Examples of the apparatus for measuring dynamic viscoelasticity include, but are not limited to, a so-called mechanical spectrum meter manufactured by Rheometrics or Iwamoto Seisakusho.

  The measurement of dynamic viscoelasticity is performed in a molten state and generally measures strain and stress called the gap load method. The gap includes a cylindrical shape, a cone and disk shape, a parallel disk shape, and the like, and is not particularly limited. However, since a polymer melt is generally handled as a viscoelastic material, a parallel disk is used. Can be measured. If the viscosity of the polymer melt is as low as that of a low molecule, it can be measured using a cylindrical shape, a cone and a disk shape, etc., so that the measurement sample will not be washed away.

  In general, for the process of finishing a polymer material into a product, that is, molding, the viscoelastic behavior of the polymer melt at the molding temperature is important. For example, there may be observed a ballast effect in which the liquid shrinks in the streamline direction when it is pulled at a high speed, or when it is pushed out from a narrow tube, but this appears as a defect such as silver or flow mark in injection molding. . Such a phenomenon is thought to originate from rheological properties, particularly elasticity, long relaxation times, and even significant non-Newtonian properties.

In this viscoelastic phenomenology, a case where a liquid of a high-viscosity polymer melt is filled between two parallel plates and shifted (shear strain) is considered. After giving a constant strain: γ = γ ₀ at time: t = 0, the stress G (t) maintaining this constant strain amount decreases exponentially with time. This time indicates the speed at which the stress inherent in the high-viscosity liquid relaxes, and is called the relaxation time and indicates a value specific to the substance. The ratio of the relaxing stress σ (t) to the constant strain γ _{0 applied at} the beginning changes with time. The elastic modulus G (t) = σ (t) / γ ₀ is called the relaxation elastic modulus. When the constant strain is a strain that vibrates sinusoidally at an angular frequency ω, the elastic modulus G * (ω) defined as the ratio of the stress and the sinusoidal strain becomes a complex number, which is referred to as a complex elastic modulus. The real part is referred to as dynamic elastic modulus or storage elastic modulus G ′, and the imaginary part is referred to as loss elastic modulus G ″, whereby the non-Newtonian property of the polymer melt can be evaluated. That is, when sinusoidal strain is applied to the viscoelastic body, the stress has the same frequency but the phase changes. As shown by tan δ = G ′ / G ″ = 1 / ωτ, the phase of the stress advances with respect to the strain by δ.

The frequency dependence curve G ′ (ω) and the frequency dependence curve G ′ in which the viscoelasticity of a polypropylene is plotted with the storage elastic modulus and the loss elastic modulus plotted on the vertical axis with the frequency ω of sinusoidal strain taken on the horizontal axis. '(Ω) is shown in FIG.
The intersection of the frequency dependence curve G ′ (ω) of the dynamic modulus measured in the frequency range of 0.01 rad / sec to 150 rad / sec and the frequency dependence curve G ″ (ω) of the loss modulus is defined as Gc. The value obtained by multiplying the reciprocal of the storage elastic modulus value in Gc (unit: Pa) by 10 ⁵ was defined as the index PI for viscoelasticity (reference: edited by Edward P. Moore, Jr., translated by Yasuda et al., (Polypropylene Handbook, 1998, Industrial Research Committee).
In the present invention, the frequency dependence curves of the storage elastic modulus and loss elastic modulus include straight lines.

  Depending on the measurement conditions, there are cases where the curves of G ′ (ω) and G ″ (ω) do not have an intersection, but can have the intersection by appropriately selecting the measurement conditions. In general, Gc can be determined at a measurement temperature of 150 to 250 ° C. In the present invention, Gc can be measured at 230 ° C. Furthermore, when the viscosity is low, the frequency dependence of the complex elastic modulus can be obtained by measuring using a conical or cylindrical shape. Here, the Newtonian property indicates that it becomes a straight line when plotted as shown in FIG. 1 (reference: edited by Japanese Society of Rheology, Lecture / Rheology (1992); Nemoto et al., Journal of Rheology, Vol. 119, 181 (1991)).

  The index PI that defines the crystalline propylene polymer of the present invention is a useful index because it can easily represent polypropylene having a broader and more complicated form of molecular weight distribution. For example, a crystalline propylene polymer is a low molecular weight substance having a molecular weight of about 5000 or less, which is difficult to measure by general gel permeation chromatography (hereinafter also referred to as GPC), or a GPC due to a limit from the exclusion limit volume of the column. When an ultra-high molecular weight substance having a molecular weight of several million or more that is not suitable for measurement is included, it is useful to use this index PI instead of the molecular weight distribution. In addition, for example, in the molecular weight distribution curve of GPC, etc., it is unclear as typified by “become twin”, “being bimodal”, “having a shoulder”, “drawing a hem”, “camel-type distribution”, etc. This is useful because it can avoid unnecessary expressions.

In the crystalline propylene polymer of the present invention, the MFR ratio between the polymer (MFR1) produced in the first reactor and the crystalline propylene polymer (MFR2) obtained by multistage polymerization is represented by the following formula. It is characterized by that.
MFR1 / MFR2> 4.0

MFR1 / MFR2 in the present invention is preferably more than 4.0, more preferably 4.2 or more, and even more preferably 4.5 or more. If MFR1 / MFR2 is 4.0 or less, the moldability is likely to deteriorate.
Thus, after producing the low molecular weight component, after producing the high molecular weight component, the catalyst is partially deactivated at the same time the low molecular weight component is produced, and in a certain portion, the high molecular weight component is not present, In this case, since the low molecular weight component has a low viscosity, the mixed state is good even in off-line mixing, and fish eyes do not occur, which does not cause a problem. Therefore, a method of producing a high molecular weight component after producing a low molecular weight component is considered good.

2. Method for Producing Crystalline Propylene Polymer The crystalline propylene polymer used in the present invention can be obtained by two or more stages of multistage polymerization.
The catalyst used for producing the crystalline propylene polymer of the present invention includes (A) a solid catalyst component containing magnesium, titanium, and halogen as essential components, and (B) a Ziegler-Natta comprising an organoaluminum compound. A catalyst is preferred.

Furthermore, the solid catalyst component (A) is obtained by bringing the following components (i), (ii), (iii) and (iv) into contact with each other.
(I) Solid component containing titanium, magnesium and halogen as essential components (ii) Organosilicon compound containing two or more Si—OR ¹ bonds (where R ¹ is a hydrocarbon residue having 1 to 8 carbon atoms) is there.)
(Iii) Vinylsilane compound (iv) Organometallic compound of periodic group I-III metal

<Component (i)>
Component (i) is a raw material solid component containing titanium, magnesium and halogen. These three elements (three components) of titanium (Ti) -magnesium (Mg) -halogen are contained as essential components. Here, “contained as an essential component” means that in addition to the listed three components, other suitable elements may be included, and each of these elements is present as an arbitrary desired compound. As well as the fact that these elements may exist as bonded to each other.
The raw material solid components themselves containing titanium, magnesium and halogen are known. For example, JP-A-53-45688, 54-3894, 54-31092, 54-39483, 54-94591, 54-118484, 54-131589, 55-75411 55-90510, 55-90511, 55-90511, 55-127405, 55-147507, 55-155003, 56-18609, 56-70005, 56-72001, 56-86905, 56-90807, 56-155206, 57-92007, 57-12003, 58-5309, 58-5310, 58 -5311, 58-8706, 58-27732, 58-32604, 58-32605, 58-67 03, 58-117206, 58-127708, 58-183708, 58-183709, 59-149905, 59-149906, 60-130607, 61-55104 61-204204, 62-508, 62-15209, 62-20507, 62-184005, 62-236805, 63-199207, 63-264607, 63-264608, JP-A-1-79203, 1-139601, 1-215806, 7-258328, 7-269125, 11-21309, etc. Is used.

  Moreover, what processed these things with tungsten or a molybdenum compound etc. are mentioned.

  Examples of the magnesium compound used as a magnesium source in the present invention include magnesium halide, dialkoxymagnesium, alkoxymagnesium halide, magnesium oxyhalide, dialkylmagnesium, magnesium oxide, magnesium hydroxide, magnesium carboxylate and the like. Of these, preferred are magnesium halide, dialkoxymagnesium, and alkoxymagnesium halide.

Moreover, the titanium compound used as the titanium source has a general formula: Ti (OR ² ) _{4 -q} X _q (where R ² is a hydrocarbon group, preferably having about 1 to 10 carbon atoms, and X is And a compound represented by the formula: q represents 0 ≦ q ≦ 4.
Specific examples include TiCl ₄ , TiBr ₄ , Ti (OC ₂ H ₅ ) Cl ₃ , Ti (OC ₂ H ₅ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₃ Cl, Ti (O-i-C _{3). H 7) Cl 3, Ti (} O-n-C 4 H 9) Cl 3, Ti (O-n-C 4 H 9) 2 Cl 2, Ti (OC 2 H 5) Br 3, Ti (OC 2 H _{5) (O-n-C} 4 H 9) 2 Cl, Ti (O-n-C 4 H 9) 3 Cl, Ti (OC 6 H 5) Cl 3, Ti (O-i-C 4 H 9) ₂ Cl ₂ , Ti (OC ₅ H ₁₁ ) Cl ₃ , Ti (OC ₆ H ₁₃ ) Cl ₃ , Ti (OC ₂ H ₅ ) ₄ , Ti (On-C ₃ H ₇ ) ₄ , Ti (O— _{n-C 4 H 9) 4} , Ti (O-i-C 4 H 9) 4, Ti (O-n-C 6 H 13) 4, Ti (O- _{-C 8 H 17) 4, Ti} (OCH 2 CH (C 2 H 5) C 4 H 9) 4 , and the like.

Further, a molecular compound obtained by reacting TiX ′ ₄ (where X ′ is a halogen) with an electron donor described later can also be used as a titanium source.
Specific examples of such molecular compounds include TiCl ₄ · CH ₃ COC ₂ H ₅ , TiCl ₄ · CH ₃ CO ₂ C ₂ H ₅ , TiCl ₄ · CH ₃ COCl, TiCl ₄ · C ₆ H ₅ COCl, TiCl _{4 · C 6 H 5 CO 2} C 2 H 5, TiCl 4 · ClCOC 2 H 5, TiCl 4 · C 4 H 4 O and the like.

In addition, TiCl ₃ (including TiCl ₄ reduced with hydrogen, aluminum metal reduced or organometallic compound reduced), TiBr ₃ , Ti (OC ₂ H ₅ ) Cl ₂ , TiCl ₂ , It is also possible to use titanium compounds such as dicyclopentadienyl titanium dichloride and cyclopentadienyl titanium trichloride. Among these titanium compounds, TiCl ₄ , Ti (OC ₄ H ₉ ) ₄ , Ti (OC ₂ H ₅ ) Cl _{3 and the} like are preferable.

The halogen is usually supplied from the aforementioned halogen compounds of magnesium and / or titanium, but other halogen sources, for example, aluminum halides such as AlCl ₃ , boron halides such as BCl ₃ , SiCl It can also be supplied from known halogenating agents such as silicon halides such as ₄ ; phosphorus halides such as PCl ₃ and PCl ₅ ; tungsten halides such as WCl ₆ ; and molybdenum halides such as MoCl ₅ .
The halogen contained in the solid component (i) may be fluorine, chlorine, bromine, iodine or a mixture thereof, and chlorine is particularly preferable.

The solid component (i) contains an electron donor (internal donor) as an optional component. As described above, the electron donor can be used as a molecular compound reacted with TiX ′ ₄ (where X ′ is a halogen), or as an unreacted compound.
Examples of the electron donor (internal donor) that can be used for the production of the raw material solid component (i) include alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic acids or inorganic acids, ethers, Examples include oxygen-containing electron donors such as acid amides and acid anhydrides, nitrogen-containing electron donors such as ammonia, amines, nitriles, and isocyanates, and sulfur-containing electron donors such as sulfonate esters. it can.

More specifically, (i) alcohols having 1 to 18 carbon atoms such as methanol, ethanol, propanol, pentanol, hexanol, octanol, dodecanol, octadecyl alcohol, benzyl alcohol, phenylethyl alcohol, isopropylbenzyl alcohol,
(B) Phenols having 6 to 25 carbon atoms that may have an alkyl group such as phenol, cresol, xylenol, ethylphenol, propylphenol, isopropylphenol, nonylphenol, naphthol,
(C) C3-C15 ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone,
(D) Aldehyde having 2 to 15 carbon atoms such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde, naphthaldehyde,

  (E) methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, cellosolve acetate, ethyl propionate, methyl butyrate, ethyl valerate, ethyl stearate, methyl chloroacetate, ethyl dichloroacetate, Methyl methacrylate, ethyl crotonate, ethyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, cellosolve benzoate , Organic acid monoesters such as methyl toluate, ethyl toluate, amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, γ-butyrolactone, α-valerolactone, coumarin, phthalide Or diethyl phthalate, dibutyl phthalate, diheptyl phthalate, diethyl succinate, dibutyl maleate, diethyl 1,2-cyclohexanecarboxylate, ethylene carbonate, norbornanedienyl-1,2-dimethylcarboxylate, cyclopropane C2-C20 organic acid esters of organic acid polyvalent esters such as -1,2-dicarboxylic acid-n-hexyl, diethyl 1,1-cyclobutanedicarboxylate,

(F) Inorganic acid esters such as silicate esters such as ethyl silicate and butyl silicate,
(G) C2-C15 acid halides such as acetyl chloride, benzoyl chloride, toluic acid chloride, anisic acid chloride, phthaloyl chloride, isophthaloyl chloride,
(H) methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, furan, tetrahydrofuran, anisole, diphenyl ether, 2,2-dimethyl-1,3-dimethoxypropane, 2,2-diisopropyl-1,3-dimethoxypropane 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2-isopropyl-2-s-butyl-1,3-dimethoxypropane, 2-t- Butyl-2-methyl-1,3-dimethoxypropane, 2-t-butyl-2-isopropyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 2,2-dicyclohexyl- 1,3-dimethoxypropane, 2,2-dipheni 1,3-dimethoxypropane, 2,2-dimethyl-1,3-diethoxy propane, 2,2-diisopropyl-1,3-ethers having 2 to 20 carbon atoms such as diethoxy propane,

(L) Acid amides such as acetic acid amide, benzoic acid amide, toluic acid amide,
(Nu) Amines such as methylamine, ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, pyridine, picoline, tetramethylethylenediamine,
(L) Nitriles such as acetonitrile, benzonitrile, tolunitrile,
(V) 2- (Ethoxymethyl) -ethyl benzoate, 2- (t-butoxymethyl) -ethyl benzoate, ethyl 3-ethoxy-2-phenylpropionate, ethyl 3-ethoxypropionate, 3-ethoxy-2 Alkoxy ester compounds such as ethyl s-butylpropionate and ethyl 3-ethoxy-2-t-butylpropionate,

(Wa) Ketoester compounds such as ethyl 2-benzoylbenzoate, ethyl 2- (4′-methylbenzoyl) benzoate, ethyl 2-benzoyl-4,5-dimethylbenzoate,
(F) Sulfonic acids such as methyl benzenesulfonate, ethyl benzenesulfonate, ethyl p-toluenesulfonate, isopropyl p-toluenesulfonate, n-butyl p-toluenesulfonate, and s-butyl p-toluenesulfonate Examples thereof include esters.

  Two or more kinds of these electron donors can be used. Among these, organic acid ester compounds, acid halide compounds and ether compounds are preferable, and particularly preferable are those selected from the group consisting of phthalic diester compounds and phthalic dihalide compounds.

  The solid component (i) is produced by, for example, the following production method using other components as necessary.

(A) A method of contacting a magnesium halide with an electron donor and a titanium-containing compound.
(B) A method in which alumina or magnesia is treated with a halogenated phosphorus compound, and a magnesium halide, an electron donor, and a titanium halogen-containing compound are brought into contact therewith.
(C) Inert reaction products obtained by contacting a titanium halide compound and / or a silicon halogen compound and an electron donor with a solid component obtained by contacting magnesium halide with titanium tetraalkoxide and a specific polymer silicon compound. A method of washing with an organic solvent. In addition, as a polymer silicon compound used here, what is shown by a following formula is suitable.

-[Si (H) (R ³ ) -O-] _X-
Here, R ³ is a hydrocarbon group having about 1 to 10 carbon atoms, and x represents a degree of polymerization such that the viscosity of the polymer silicon compound is about 1 to 100 centistokes. Specifically, methyl hydrogen polysiloxane, ethyl hydrogen polysiloxane, phenyl hydrogen polysiloxane, cyclohexyl hydrogen polysiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3,5,7 , 9-pentamethylcyclopentasiloxane is preferred.

(D) A magnesium compound is dissolved with a titanium tetraalkoxide and / or an electron donor, and the titanium compound and the electron donor are brought into contact with a solid component precipitated with a halogenating agent or a titanium halogen compound. How to contact.
(E) An organomagnesium compound such as a Grignard reagent is allowed to act on a halogenating agent, a reducing agent, etc., and then contacted with an electron donor as necessary, and then a titanium compound and an electron donor are contacted. , How to contact each one separately.
(F) A method in which an alkoxymagnesium compound is contacted with a halogenating agent and / or a titanium compound in the presence or absence of an electron donor, or each is contacted separately.
Among these production methods, (A), (C), (D) and (F) are preferable.
The solid component (i) can be used as the solid catalyst component (A). Moreover, what made the solid component (i) and the below-mentioned (ii), (iii), and (iv) contact can also be used as a solid catalyst component (A).

<Component (ii)>
The component (ii) used for producing the solid catalyst component (A) according to the present invention is an organosilicon compound containing two or more Si—OR ¹ bonds (provided that R ¹ has 1 to 8 carbon atoms) Hydrocarbon group).

In the present invention, the bonding residue other than the —OR ¹ group bonded to the silicon atom is selected from hydrogen, halogen, a hydrocarbon group (eg, an alkyl group, a cycloalkyl group, an aryl group, etc.) and a siloxy group. It is usual to use one having a binding residue.

  Preferred organosilicon compounds in the present invention are those having at least one hydrocarbon group, more preferably a carbon atom adjacent to the silicon atom, that is, the α-position hydrocarbon atom is a secondary or tertiary carbon atom. It has a C3-C20 branched chain hydrocarbon group.

Specific examples of the organosilicon compound of component (ii) include (CH ₃ ) ₃ CSi (CH ₃ ) (OCH ₃ ) ₂ , (CH ₃ ) ₃ CSi (CH (CH ₃ ) ₂ ) (OCH ₃ ) ₂ , (CH ₃ ) ₃ CSi (CH ₃ ) (OC ₂ H ₅ ) ₂ , (CH ₃ ) ₃ CSi (C ₂ H ₅ ) (OCH ₃ ) ₂ , (CH ₃ ) ₃ CSi (n—C ₃ H ₇ ) (OCH ₃ ) ₂ , (CH ₃ ) ₃ CSi (n—C ₆ H ₁₃ ) (OCH ₃ ) ₂ , (C ₂ H ₅ ) ₃ CSi (CH ₃ ) (OCH ₃ ) ₂ , (CH ₃ ) (C _{2 H 5) CHSi (CH 3} ) (OCH 3) 2, ((CH 3) 2 CHCH 2) 2 Si (OCH 3) 2, (C 2 H 5) (CH 3) 2 CSi (CH 3) (OCH _{3) 2, (C 2 H} 5) (CH 3) 2 CSi (C _{3) (OC 2 H 5)} 2, (CH 3) 3 CSi (OCH 3) 3, (CH 3) 3 CSi (OC 2 H 5) 3, (CH 3) (C 2 H 5) CHSi (OCH 3 ) ₃ , (CH ₃ ) ₂ CH (CH ₃ ) ₂ CSi (CH ₃ ) (OCH ₃ ) ₂ , ((CH ₃ ) ₃ C) ₂ Si (OCH ₃ ) ₂ , (C ₂ H ₅ ) (CH ₃ ) ₂ CSi (OCH ₃ ) ₃ , (C ₂ H ₅ ) (CH ₃ ) ₂ CSi (OC ₂ H ₅ ) ₃ , (CH ₃ ) ₃ CSi (OC (CH ₃ ) ₃ ) (OCH ₃ ) ₂ , ( (CH ₃ ) ₂ CH) ₂ Si (OCH ₃ ) ₂ , ((CH ₃ ) ₂ CH) ₂ Si (OC ₂ H ₅ ) ₂ , (C ₅ H ₉ ) ₂ Si (OCH ₃ ) ₂ , (C _{5 H 9) 2 Si (OC 2} H 5) 2, (C 5 H 9) (CH 3) S _{(OCH 3) 2, (C} 5 H 9) ((CH 3) 2 CHCH 2) Si (OCH 3) 2, (C 6 H 11) Si (CH 3) (OCH 3) 2, (C 6 H 11 ) ₂ Si (OCH ₃ ) ₂ , (C ₆ H ₁₁ ) ((CH ₃ ) ₂ CHCH ₂ ) Si (OCH ₃ ) ₂ , ((CH ₃ ) ₂ CHCH ₂ ) ((C ₂ H ₅ ) (CH ₃ ) CH) Si (OCH ₃ ) ₂ , ((CH ₃ ) ₂ CHCH ₂ ) ((CH ₃ ) ₂ CH) Si (OC ₅ H ₁₁ ) ₂ , HC (CH ₃ ) ₂ C (CH ₃ ) ₂ Si ( _{CH 3) (OCH 3) 2} , HC (CH 3) 2 C (CH 3) 2 Si (CH 3) (OC 2 H 5) 2, HC (CH 3) 2 C (CH 3) 2 Si (OCH 3 _{) 3, (CH 3) 3} CSi (OCH (CH 3) 2) (O H _{3) 2,} include ₂ or the like _{(CH 3) 3 CSi (OC} (CH 3) 3) (OCH 3).

Among these, preferred are (CH ₃ ) ₃ CSi (CH ₃ ) (OCH ₃ ) ₂ , (CH ₃ ) ₃ CSi (CH (CH ₃ ) ₂ ) (OCH ₃ ) ₂ , (CH ₃ ) ₃ CSi (CH ₃ ) (OC ₂ H ₅ ) ₂ , (CH ₃ ) ₃ CSi (C ₂ H ₅ ) (OCH ₃ ) ₂ , (CH ₃ ) ₃ CSi (n—C ₃ H ₇ ) (OCH _{3 ) 2, (CH 3) 3} CSi (n-C 6 H 13) (OCH 3) 2, (C 5 H 9) 2 Si (OCH 3) 2, (C 5 H 9) 2 Si (OC 2 H 5 ) ₂ , (C ₆ H ₁₁ ) Si (CH ₃ ) (OCH ₃ ) ₂ , (C ₆ H ₁₁ ) ₂ Si (OCH ₃ ) _{2 and the} like.

<Ingredient (iii)>
Component (iii) is a vinyl silane compound. Examples of the vinylsilane compound include compounds in which at least one hydrogen atom in monosilane (SiH ₄ ) is replaced with a vinyl group (CH ₂ ═CH—). And some of the remaining hydrogen atoms are halogen (preferably Cl), alkyl group (preferably alkyl group having 1 to 12 carbon atoms), aryl group (preferably phenyl group), alkoxy group (preferably carbon number). 1 to 12 alkoxy groups) and other structures may be substituted.

More _{specifically, CH 2 = CH-SiH 3} , CH 2 = CH-SiH 2 (CH 3), CH 2 = CH-SiH (CH 3) 2, CH 2 = CH-Si (CH 3) 3, _{CH 2 = CH-SiCl 3,} CH 2 = CH-SiCl 2 (CH 3), CH 2 = CH-SiCl (CH 3) 2, CH 2 = CH-SiH (Cl) (CH 3), CH 2 = CH _{-Si (C 2 H 5) 3} , CH 2 = CH-SiCl (C 2 H 5) 2, CH 2 = CH-SiCl 2 (C 2 H 5), CH 2 = CH-Si (CH 3) 2 ( _{C 2 H 5), CH 2} = CH-Si (CH 3) (C 2 H 5), (CH 2 = CH) 2 -SiH 2, (CH 2 = CH) 2 -SiH (CH 3), (CH _{2 = CH) 2 -SiH (CH} 3), (CH 2 = CH) _{-Si (CH 3) 2, (} CH 2 = CH) 2 -SiCl 2, (CH 2 = CH) 2 -SiCl (CH 3), (CH 2 = CH) 2 -SiH (Cl), (CH 2 = _{CH) 2 -Si (C 2 H} 5) 2, (CH 2 = CH) 2 -SiCl (C 2 H 5), (CH 2 = CH) 2 -Si (CH 3) (C 2 H 5), ( _{CH 2 = CH) 3 -SiH,} (CH 2 = CH) 3 -Si (CH 3), (CH 2 = CH) 3 -SiCl, (CH 2 = CH) 3 -Si (C 2 H 5), ( CH ₂ ═CH) ₄ —Si and the like can be exemplified.
Of _{these, CH 2 = CH-Si (} CH 3) 3, (CH 2 = CH) 2 -Si (CH 3) 2 is preferred.

<Component (iv)>
Component (iv) is an organometallic compound belonging to Groups 1-3 of the periodic table. Since it is an organometallic compound, this compound has at least one organic group / metal bond. The organic group in that case is typically a hydrocarbon group having about 1 to 10 carbon atoms, preferably about 1 to 6 carbon atoms.
Further, examples of the metal of this compound include lithium, magnesium, aluminum and zinc, and aluminum is typical.

The remaining valence (if any) of the metal of the organometallic compound in which at least one of the valences is filled with an organic group is the hydrogen atom, halogen atom, hydrocarbon group (the hydrocarbon group is the number of carbon atoms) About 1 to 10, preferably about 1 to 6, or the metal via a carbon atom (specifically, —O—Al (CH ₃ ) — of methylalumoxane) and others.

Specific examples of such organometallic compounds include (a) organolithium compounds such as methyllithium, n-butyllithium and tert-butyllithium, (b) butylethylmagnesium, dibutylmagnesium, hexylethylmagnesium and butylmagnesium. Organic magnesium compounds such as chloride and tert-butylmagnesium bromide, (c) Organic zinc compounds such as diethylzinc and dibutylzinc, (d) Trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n -Octyl aluminum, tri-n-decyl aluminum, diethyl aluminum monochloride, diisobutyl aluminum monochloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride Diethylaluminum hydride, diisobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminum phenoxide, and organic aluminum compounds such as methylaluminoxane.
Of these, organoaluminum compounds are particularly preferred.

<Production of solid catalyst component (A)>
In the solid catalyst component (A), the solid component (i) may be used as the solid catalyst component (A), but each component (i) to (iv) and optional components used as necessary may be used stepwise or It can also be produced by temporarily contacting each other and washing with an organic solvent in the middle and / or finally.
Specifically, (a): a method in which the component (i) and the component (iii) are contacted, then the component (ii) and the component (iv) are contacted, and finally washed (b): the component ( Method of contacting and washing component (iii) and component (iv) after contacting i) and component (ii), (c): contacting component (i), (ii), and (iii) simultaneously Later, a method of bringing component (iv) into contact and washing is employed.

  Solvents used for solvent cleaning include inert organic solvents, such as aliphatic or aromatic hydrocarbon solvents (eg, hexane, heptane, toluene, cyclohexane, etc.), or halogenated hydrocarbon solvents (eg, n-butyl chloride). 1,2-dichloroethylene, carbon tetrachloride, chlorobenzene, etc.).

The contact condition of each component constituting the solid catalyst component (A) needs to be carried out in the absence of oxygen, but may be any as long as the effect of the present invention is recognized. The following conditions are preferred.
The contact temperature is about −50 to 200 ° C., preferably 0 to 100 ° C. Examples of the contact method include a mechanical method using a rotating ball mill, a vibration mill, a jet mill, a medium stirring pulverizer, and the like, and a method of contacting by stirring in the presence of an inert diluent. Examples of the inert diluent used at this time include aliphatic or aromatic hydrocarbons, halogenated hydrocarbons, and polysiloxanes.

The amount ratio of each component used to constitute the solid catalyst component (A) can be arbitrary as long as the effect of the present invention is recognized, but generally it is preferably within the following range.
The usage-amount of the titanium compound of a component (i) is 0.0001-1000 by the molar ratio (Ti / Mg) with respect to the usage-amount of the magnesium compound to be used, Preferably it is 0.01-10. When a compound therefor is used as the halogen source, the amount used is 0.01 by mole relative to the amount of magnesium used, regardless of whether the titanium compound and / or magnesium compound contains halogen. -1000 is good, preferably 0.1-100. The use amount of the electron donor is 0.001 to 10 in molar ratio (halogen / Mg) to the use amount of the magnesium compound, preferably 0.01 to 5.

  The amount ratio of the component (i) and the component (ii) is 0.01 to 1000, preferably 0.1 in terms of the molar ratio of silicon of the component (ii) to the titanium component constituting the component (i) (silicon / titanium). ~ 100. The amount ratio of component (iii) to component (i) is 0.01 to 1000, preferably 0 in terms of the molar ratio of silicon atoms in component (iii) to titanium atoms in component (i) (silicon / titanium). .01-300. The amount ratio of the component (iii) to the component (i) is 0.01 to 1000, preferably 0.1 to 100, in terms of the metal molar ratio (metal / titanium) of the organometallic compound. The amount of the organometallic compound of component (iv) used is 0.1 to 100, preferably 1 to 50 in terms of the molar ratio of metal to the titanium component constituting component (i) (metal atom / titanium). In the middle and / or at the end of the production of the solid catalyst component (A), in addition to the solvent washing, a washing step with an inert organic solvent similar to that used in the solvent washing may be added. it can.

The (B) organoaluminum compound is used as a co-catalyst, for example, trialkylaluminum such as trimethylaluminum, triethylaluminum and triisobutylaluminum, alkylaluminum halide such as diethylaluminum chloride and diisobutylaluminum chloride, diethylaluminum hydride and the like Alkyl aluminum hydrides, alkyl aluminum alkoxides such as diethyl aluminum ethoxide, alumoxanes such as methylalumoxane and tetrabutylalumoxane, complex organoaluminum compounds such as dibutyl methylboronate, and lithium aluminum tetraethyl.
It is also possible to use a mixture of two or more of these.

In the production of the crystalline propylene polymer of the present invention, an electron donating compound (external donor) which is a polymerization additive (C) can be further used. As the electron donating compound (external donor), those exemplified as the electron donating compound (internal donor) in the case of the solid component (ii) and containing two or more Si—OR ¹ bonds exemplified in the component (iii) An organosilicon compound etc. can be illustrated. Among these, in particular, when tert-butylmethyldimethoxysilane is used as an external donor at the time of production, the isotactic pentad fraction (mmmm fraction) of the propylene polymer is further increased, and the rigidity is improved.

  In the catalyst containing the solid catalyst component (A) obtained by contacting the components (i) to (iv) and the organoaluminum (B), the melt flow rate varies greatly depending on the amount of hydrogen as a chain transfer agent ( (Hydrogen-MFR responsiveness is high).

As a polymerization mode, it is carried out by multi-stage polymerization combining a bulk polymerization process using propylene itself as a polymerization solvent and a gas phase polymerization process for polymerizing raw material propylene in a gas phase.
Each step of the bulk polymerization step and the gas phase polymerization step may have any number of steps. Examples thereof include a method in which bulk polymerization is performed in two stages and subsequently gas phase polymerization is performed in one stage, and a method in which bulk polymerization is performed in one stage and gas phase polymerization is performed in one stage.
However, it is preferable that each step of the bulk polymerization step and the gas phase polymerization step has two or more steps because the molecular weight distribution can be easily widened by the polymerization blend and more elastic properties can be imparted.

  Further, in the melt flow rate of the crystalline propylene polymer obtained from each stage of the multistage polymerization, it is preferable that the melt flow rate in the subsequent stage is at least lower than the melt flow rate in the previous stage. If the melt flow rate is higher than that in the previous stage, the crystalline propylene polymer may have insufficient melt elasticity or increase fish eyes.

In the production method of the present invention, the MFR ratio between the polymer (MFR1) produced in the first reactor and the crystalline propylene polymer (MFR2) obtained by multistage polymerization is represented by the following formula: To do.
MFR1 / MFR2> 4.0

As described above, MFR1 / MFR2 in the present invention is more than 4.0, preferably 4.2 or more, and more preferably 4.5 or more. If MFR1 / MFR2 is 4.0 or less, the molding processability is lowered, which is inconvenient.
Thus, after producing the low molecular weight component, after producing the high molecular weight component, the catalyst is partially deactivated at the same time the low molecular weight component is produced, and in a certain portion, the high molecular weight component is not present, In this case, since the low molecular weight component has a low viscosity, the mixed state is good even in off-line mixing, and fish eyes do not occur, which does not cause a problem. Therefore, a method of producing a high molecular weight component after producing a low molecular weight component is considered good.

  The crystalline propylene polymer of the present invention is a multi-stage that combines a bulk polymerization process using propylene itself as a polymerization solvent in the presence of a propylene polymerization catalyst and a gas phase polymerization process for polymerizing raw material propylene in a gas phase. It can be produced by polymerizing or copolymerizing propylene or a comonomer selected from propylene and an α-olefin such as ethylene. At that time, the chain transfer agent hydrogen is mainly charged into the bulk polymerization of the former stage to produce a high melt flow rate, and in the gas phase polymerization of the latter stage, further hydrogen is added to the hydrogen brought in from the previous stage according to the situation. By adding, it is preferable to produce a low melt flow rate. Here, by using the above catalyst as a propylene polymerization catalyst, it becomes possible to easily make a difference in melt flow rate and to obtain a crystalline propylene polymer having high melt elasticity.

  The polymerization reactor is not particularly limited in shape and structure, but a tank with a stirrer generally used in bulk polymerization, a tube reactor, a fluidized bed reactor in gas phase polymerization, a horizontal reactor having a stirring blade, etc. Is mentioned.

  As the polymerization tank, two or more tanks connected in series are used. The solid catalyst component (A) is supplied only to the first polymerization tank, and most of the organoaluminum (B) is supplied to the first polymerization tank. It doesn't matter.

In the first polymerization tank, a predetermined amount of propylene is continuously supplied under a constant polymerization pressure and temperature, and the catalyst and hydrogen are controlled so that the ratio of propylene to hydrogen is constant. The produced polymer is sequentially transferred to the next stage polymerization tank together with the unreacted raw material. In the second and subsequent polymerization tanks, no catalyst is supplied, and polymerization is carried out with the catalyst contained in the polymer transferred from the preceding polymerization tank.
In the second and subsequent polymerization tanks, the supply of propylene is continued so that the polymerization pressure is maintained at a predetermined value. Hydrogen may or may not be supplied after the second polymerization tank. When not supplied, hydrogen remaining as unreacted in the previous polymerization tank is transferred to the next-stage reactor and used. In order to give a broader molecular weight distribution and impart elastic properties, it is better not to supply after the second polymerization tank.

  In the polymerization method of the present invention, the polymerization pressure is not particularly limited, but is usually 0.2 to 5 MPa, preferably about 0.3 to 2 MPa. The polymerization pressure at each stage may be the same or different.

  Moreover, in the polymerization method of this invention, although it does not specifically limit regarding polymerization temperature, Usually, 20-100 degreeC, Preferably it selects from the range of 40-80 degreeC. The polymerization temperature at each stage may be the same or different.

  Furthermore, in the polymerization method of the present invention, the polymerization time is not particularly limited, but is usually 10 minutes to 10 hours. Generally, 30 minutes to 2 hours are standard for bulk polymerization, gas phase polymerization step, each step, and bulk polymerization, and 2 to 5 hours are standard for gas phase polymerization. In addition, the polymerization time of each stage of the multistage is not particularly limited, but is set to 30 minutes for the first stage, 30 minutes for the second stage, and 1 hour for the third stage.

3. Polypropylene resin composition The polypropylene resin composition of the present invention comprises 0.05 to 0.15 parts by weight of a nucleating agent per 100 parts by weight of a crystalline propylene polymer.

  In the present invention, the nucleating agent is used in an amount of 0.05 to 0.15 parts by weight, preferably 0.05 to 0.12 parts by weight, based on 100 parts by weight of the crystalline propylene polymer. -0.10 weight part is further more preferable. If the amount of the nucleating agent used exceeds 0.15 parts by weight, the production cost increases, which is inconvenient.

  Specific examples of the nucleating agent include sodium-2,2′-methylene-bis- (4,6-di-t-butylphenyl) phosphate, sodium-2,2′-ethylidene-bis- (4 , 6-Di-t-butylphenyl) phosphate, sodium-2,2'-ethylidene-bis- (4-i-propyl-6-t-butylphenyl) phosphate, sodium-2,2'-butylidene- Bis- (4,6-dimethylphenyl) phosphate, sodium-2,2′-butylidene-bis- (4,6-di-t-butylphenyl) phosphate, sodium-2,2′-t-octylmethylene -Bis- (4,6-methylphenyl) phosphate, sodium-2,2'-tert-octylmethylene-bis- (4,6-di-tert-butylphenyl) phosphate Sodium-2,2′-methylene-bis- (4-methyl-6-tert-butylphenyl) phosphate, sodium-2,2′-methylene-bis- (4-ethyl-6-tert-butyl) Phenyl) phosphate, sodium (4,4′-dimethyl-6,6′-di-t-butyl-2,2′-biphenyl) phosphate, sodium-2,2′-ethylidene-bis- (4-s -Butyl-6-t-butylphenyl) phosphate, sodium-2,2'-methylene-bis- (4,6-di-methylphenyl) phosphate, sodium-2,2'-methylene-bis- (4 , 6-di-ethylphenyl) phosphate and the like, but is not limited thereto.

  In the polypropylene resin composition containing the crystalline propylene polymer and the crystalline propylene polymer of the present invention, known antioxidants, neutralizing agents, antistatic agents, and weather resistance used in conventional polyolefins are optionally added. An agent or the like may be added.

  The crystalline propylene polymer of the present invention can be used alone as it is, or can be used by adding another polypropylene or another polymer such as ethylene rubber.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples. Analysis and evaluation methods performed in Examples and Comparative Examples are as follows.

1. Melt flow rate (MFR)
MFR was measured according to JIS K6758 (conditions 230 ° C., load 2.16 kgf) (unit: g / 10 minutes).

2. Flexural modulus Test specimens were prepared by injection molding according to the method described in JIS K6758 and measured at 23 ° C. at a bending speed of 2 mm / min according to JIS K7203.

3. Melting point (Tm)
The melting point (Tm) was measured using a Seiko DSC. After taking 5.0 mg of sample and holding it at 200 ° C. for 5 minutes, it is crystallized at a rate of temperature decrease of 10 ° C./min to 40 ° C. to erase its thermal history, and further melted at a rate of temperature increase of 10 ° C./min. The melting point (Tm) was defined as the peak temperature of the melting curve.

4). Ethylene content The ethylene content was measured with an infrared spectrometer (IR700 manufactured by JASCO Corporation).

5. Temperature rising elution fractionation (TREF)
The method described in the present specification was carried out, and the component (40 ° C. sol.) Eluted at a temperature of 40 ° C. or lower and the temperature (Tp) when the amount of the eluted component was the largest were measured.

6). Measurement of dynamic viscoelasticity A propylene-based resin was compression-molded by a press at 230 ° C. for 5 minutes so as not to contain bubbles, and a disk-shaped measurement sample having a thickness of 1.5 mm and a diameter of 25 mm was obtained.
The measurement was performed using a rheometer (RMS800) manufactured by Rheometrics. Using parallel disks with a diameter of 25 mm arranged with a gap of 1.4 mm, a sample with an MFR of 2 g / 10 min or less is 230 ° C., a sample with an MFR of over 2 g / 10 min is 210 ° C., The storage elastic modulus (G ′) and loss elastic modulus (G ″) were measured at a frequency range of 0.01 rad / sec to 150 rad / sec. Curve G '(omega) and G''(omega) and a storage modulus at Gc point of intersection is (unit: Pa) 10 ⁵ times the reciprocal of the PI.

7). Thermoformability test (Drawdown resistance evaluation)
The polypropylene obtained in each of Examples and Comparative Examples was molded into a sheet for thermoforming, and the drawdown resistance was evaluated. The sheet is cut to a size of 300 mm square, the opening is fixed horizontally to a frame having a size of 250 mm × 250 mm, and this is heated from above and below by a 400 ° C. heater. In this state, the phenomenon shown in FIG. 2 occurs between the amount of sag (sag length) and the heating time of the sheet.
First, the central part of the sheet hangs down by heating. The sagging sheet then lifts and then sags again. This time the return phenomenon does not occur.
The time required for the amount of sag to reach 10 mm and 20 mm from the time when the above-mentioned first sag was returned was defined as “holding time”. It can be said that the longer the “holding time”, the more excellent the vacuum forming and pressure forming properties.

[Example 1]
(I) Production of solid catalyst component (a) 20 liters of dehydrated and deoxygenated n-heptane was introduced into a tank equipped with a stirrer with an internal volume of 50 liters purged with nitrogen, and then 10 moles of magnesium chloride and 20 moles of tetrabutoxytitanium And then reacting at 95 ° C. for 2 hours, lowering the temperature to 40 ° C., introducing 12 liters of methylhydropolysiloxane (viscosity 20 centistokes), and further reacting for 3 hours. The solid component produced was removed and washed with n-heptane.
Subsequently, 5 liters of dehydrated and deoxygenated n-heptane was introduced into the tank using the tank equipped with a stirrer, and then 3 mol of the solid component synthesized above was introduced in terms of magnesium atom. Subsequently, 5 mol of silicon tetrachloride was mixed with 2.5 liters of n-heptane and introduced at 30 ° C. for 30 minutes. The temperature was raised to 70 ° C. and reacted for 3 hours. Then, the reaction solution was taken out, The resulting solid component was washed with n-heptane.
Subsequently, 2.5 liters of dehydrated and deoxygenated n-heptane was introduced into the tank using the tank with a stirrer, and 0.3 mol of phthalic acid chloride was mixed and introduced at 90 ° C. for 30 minutes. And reacted at 95 ° C. for 1 hour. After completion of the reaction, washing with n-heptane was performed. Next, 2 liters of titanium tetrachloride was added at room temperature, and the temperature was raised to 100 ° C., followed by reaction for 2 hours. After completion of the reaction, washing with n-heptane was performed. Further, 0.6 liters of silicon tetrachloride and 8 liters of n-heptane were introduced, reacted at 90 ° C. for 1 hour, and sufficiently washed with n-heptane to obtain a solid component. This solid component contained 1.30% by weight of titanium.
Next, 8 liters of n-heptane, 400 g of the solid component obtained above, 0.27 mol of t-butylmethyldimethoxysilane and 0.27 mol of vinyltrimethylsilane were introduced into the tank equipped with a stirrer substituted with nitrogen, Contact was made at 30 ° C. for 1 hour. Next, the mixture was cooled to 15 ° C., 1.5 mol of triethylaluminum diluted in n-heptane was introduced over 15 minutes under 15 ° C., and after the introduction, the temperature was raised to 30 ° C. and reacted for 2 hours. The solid catalyst component (a) (390 g) was obtained by washing with heptane.
The obtained solid catalyst component (a) contained 1.22% by weight of titanium.
Further, 6 liters of n-heptane and 1 mol of triisobutylaluminum diluted in n-heptane were introduced over 30 minutes at 15 ° C., and then about 0.4 kg of propylene was controlled so as not to exceed 20 ° C. Per hour for 1 hour to conduct prepolymerization.
As a result, a polypropylene-containing solid catalyst component (a) in which 0.9 g of propylene was polymerized per 1 g of solid was obtained.

(Ii) Production of crystalline propylene polymer 1 Crystalline propylene polymer 1 was obtained using a polymerization tank in which two stirred bulk polymerization tanks and two gas phase fluidized beds, a total of four, were connected.
As the catalyst, the solid catalyst component (a) after the prepolymerization is continuously supplied to the first reactor so as to achieve a target production amount, and triethylaluminum as a co-catalyst is also added to the first reactor only in the catalyst. Was continuously fed at a molar ratio of 5 to magnesium. Further, tert-butylmethyldimethoxysilane as an electron donating compound was added to the first reactor only at 3.0 mol. ppm was fed continuously.
The operating conditions of each polymerization tank were as follows: the first reactor was a bulk polymerization with a temperature of 70 ° C., a pressure of 2.8 MPaG, a hydrogen concentration of 2.5 mol%, an average residence time of 0.5 hours, and the second reactor was Bulk polymerization with 67 ° C., pressure 2.5 MPaG, hydrogen concentration 1.3 mol%, average residence time 0.4 hour, third reactor 80 ° C., pressure 1.7 MPaG, average residence time 0.7 hour, hydrogen Gas phase polymerization at a concentration of 4.0 × 10 ⁻² mol%, the fourth reactor is a gas phase at 80 ° C., a pressure of 1.1 MPaG, a hydrogen concentration of 3.9 × 10 ⁻³ mol% and an average residence time of 1.4 hours. Performed by polymerization.
As a result of this polymerization, a crystalline propylene polymer 1 having a catalytic activity of 31,000 gPP / gcat and an MFR of 0.33 g / 10 min was obtained. The MFR obtained in each stage was 1.91 g / 10 minutes from the first reactor, 1.82 g / 10 minutes from the second reactor, 0.73 g / 10 minutes from the third reactor, and the fourth reaction. The output was 0.33 g / 10 min [MFR ratio (MFR1 / MFR2) = 5.8].
The measured physical properties of the obtained crystalline propylene polymer 1 are shown in Table 1.

(Iii) Production of polypropylene resin composition 1 With respect to 100 parts by weight of the crystalline propylene polymer 1, 0.05 part by weight of IRGANOX 1010 (phenolic antioxidant) and 0 part of IRGAFOS168 (phosphorous processing stabilizer) 0.1 part by weight, 0.05 part by weight of DHT4A (hydrotalcite), and Adekastab NA11 (sodium-2,2-methylenebis (4,6-di-t-butylphenyl) phosphate) as a nucleating agent The polypropylene resin composition 1 was obtained by mix | blending 1 weight part, melt-kneading using an extruder, and pelletizing.

The pellets obtained above were melt-extruded from a 40 mmφ extruder into a sheet having a resin temperature of 240 ° C. and a width of 400 mm. Next, the molten sheet was guided to a polishing roll (polishing temperature: upper 50 ° C., middle 80 ° C., lower 50 ° C.) and solidified by cooling to produce a polypropylene sheet having a thickness of 0.5 mm and a width of 350 mm.
The results of the evaluation of the mechanical properties and thermoformability of the sheet thus obtained are shown in Table 1.

[Example 2]
(I) Production of crystalline propylene polymer 2 The hydrogen concentrations in the first, second, third and fourth reactors were 3.0 mol%, 1.5 mol% and 5.0 × 10 ⁻² mol, respectively. %, 4.7 × 10 ⁻³ mol%, and the same conditions as in Example 1 were used.
As a result of this polymerization, a crystalline propylene polymer 2 having a catalytic activity of 32,000 gPP / gcat and an MFR of 0.60 g / 10 min was obtained.
In addition, the MFR obtained in each stage was 1.98 g / 10 minutes from the first reactor, 2.43 g / 10 minutes from the second reactor, 1.19 g / 10 minutes from the third reactor, and the fourth reaction. The output was 0.60 g / 10 min [MFR ratio (MFR1 / MFR2) = 5.0].
The measured physical properties of the obtained crystalline propylene polymer 2 are shown in Table 1.

(Ii) Production of polypropylene resin composition 2 With respect to 100 parts by weight of crystalline propylene polymer 2, 0.05 part by weight of IRGANOX 1010, 0.1 part by weight of IRGAFOS 168, 0.05 part by weight of DHT4A, nucleation A polypropylene resin composition 2 was obtained by blending 0.1 part by weight of NA11 as an agent, and melt-kneading and pelletizing using an extruder.
Thereafter, sheet molding and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
(I) Production of crystalline propylene polymer 3 Crystalline propylene polymer 3 was obtained using a polymerization tank in which two stirred bulk polymerization tanks and two gas phase fluidized beds, a total of four, were connected.
The solid catalyst component (a) after the prepolymerization as a catalyst is continuously supplied to the first reactor so as to reach a target production amount, and triethylaluminum as a cocatalyst is also supplied only to the first reactor. It supplied continuously so that it might be set to 5 molar ratio with respect to the magnesium in a catalyst. Further, tert-butylmethyldimethoxysilane as an electron donating compound was added to the first reactor only at 3.0 mol. ppm was fed continuously.
The operating conditions of each polymerization tank were as follows: the first reactor had a temperature of 70 ° C., a pressure of 2.9 MPaG, a hydrogen concentration of 2.4 mol%, an ethylene concentration of 0.3 mol%, and an average residence time of 0.5 hours. Polymerization, the second reactor is 67 ° C., the pressure is 2.6 MPaG, the hydrogen concentration is 1.4 mol%, the ethylene concentration is 0.2 mol%, the average residence time is 0.4 hour bulk polymerization, the third reactor is 80 C., pressure 1.7 MPaG, average residence time 0.7 hours, hydrogen concentration 2.1 × 10 ⁻² mol%, ethylene concentration 0.1 mol% gas phase polymerization, fourth reactor is 80 ° C., pressure 1 The gas phase polymerization was performed at a pressure of 0.1 MPaG, a hydrogen concentration of 2.8 × 10 ⁻³ mol%, an ethylene concentration of 5.0 × 10 ⁻³ mol%, and an average residence time of 1.4 hours.
As a result of this polymerization, a crystalline propylene polymer 3 having a catalytic activity of 35,000 gPP / gcat, an MFR of 0.61 g / 10 min, and an ethylene content of 0.35 wt% was obtained.
The MFR obtained in each stage was 3.40 g / 10 minutes from the first reactor, 2.90 g / 10 minutes from the second reactor, 1.40 g / 10 minutes from the third reactor, and the fourth reaction. The output was 0.61 g / 10 min [MFR ratio (MFR1 / MFR2) = 5.6].
The measured physical properties of the obtained crystalline propylene polymer 3 are shown in Table 1.

(Ii) Production of polypropylene resin composition 3 With respect to 100 parts by weight of crystalline propylene polymer 3, 0.05 part by weight of IRGANOX 1010, 0.05 part by weight of IRGAFOS 168 and 0.05 part by weight of calcium stearate are blended. The polypropylene resin composition 3 was obtained by melt-kneading and pelletizing using an extruder.
Thereafter, in the same manner as in Example 1, sheet forming and evaluation were performed. The results are shown in Table 1.

[Comparative Example 2]
(I) Production of solid catalyst component (b) 6 liters of n-hexane, 5.0 mol of diethylaluminum monochloride (DEAC), and 12.0 mol of diisoamyl ether were mixed at 25 ° C. for 5 minutes, and the same temperature for 5 minutes. To obtain a reaction solution (I) (diisoamyl ether / DEAC molar ratio 2.4). 40 moles of titanium tetrachloride was placed in a nitrogen-substituted reactor and heated to 35 ° C., and the entire amount of the reaction solution (I) was added dropwise to the reactor over 180 minutes, then kept at the same temperature for 30 minutes and heated to 75 ° C. The reaction was further allowed to proceed for 1 hour, cooled to room temperature, the supernatant was removed, 30 liters of n-hexane was added, and decantation was repeated 4 times to obtain 1.9 kg of a solid product (II). .
With the total amount of this solid product (II) suspended in 30 liters of n-hexane, 1.6 kg of diisoamyl ether and 3.5 kg of titanium tetrachloride were added at 20 ° C. over about 5 minutes at room temperature. And reacted at 60 ° C. for 1 hour. After completion of the reaction, the mixture was cooled to room temperature (20 ° C.), the supernatant was removed by decantation, 30 liters of n-hexane was added, stirred for 15 minutes, and allowed to stand to remove the supernatant 5 times. After repeating, it was dried under reduced pressure to obtain a solid catalyst component (b).

(Iii) Production of preactivated catalyst (c) After replacing a stainless steel reactor with an inclined volume of 200 liters with inclined blades with nitrogen gas, 20 liters of n-hexane, 420 g of diethylaluminum monochloride, solid catalyst component (b) After adding 30 g at room temperature, the mixture was reacted at a propylene partial pressure of 5 kg / cm ² G for 5 minutes, and unreacted propylene and n-hexane were removed under reduced pressure to obtain a pre-activated catalyst (c) powder. (30.0 g reaction of propylene per gram of solid product (b)).

(Iii) Production of Crystalline Propylene Polymer 4 Crystalline propylene polymer 4 was obtained using one stirred bulk polymerization tank.
A pre-activated catalyst (c) is continuously supplied as a catalyst so as to reach a target production amount, diethylaluminum monochloride as a co-catalyst is 450 wtppm, and methyl methacrylate as an electron donating compound is continuously 7.0 wtppm. Supplied.
Further, bulk polymerization was performed with the polymerization tank operating at a temperature of 70 ° C., a pressure of 3.0 MPaG, a hydrogen concentration of 0.6 mol%, and an average residence time of 2.8 hours.
As a result of this polymerization, a crystalline propylene polymer 4 having a catalyst activity of 4,500 gPP / gcat and an MFR of 0.50 g / 10 min was obtained.
The measured physical properties of the obtained crystalline propylene polymer 4 are shown in Table 1.

(Iv) Production of polypropylene resin composition 4 100 parts by weight of crystalline propylene polymer 4 is blended with 0.1 part by weight of IRGANOX 1010, 0.1 part by weight of IRGAFOS 168 and 0.1 part by weight of calcium stearate. The polypropylene resin composition 4 was obtained by melt-kneading and pelletizing using an extruder.
Thereafter, in the same manner as in Example 1, sheet forming and evaluation were performed. The results are shown in Table 1.

[Comparative Example 3]
(I) Production of Crystalline Propylene Polymer 5 Crystalline propylene polymer 5 was obtained using a polymerization tank in which a total of four stirred bulk polymerization tanks and two gas phase fluidized beds were connected.
The solid catalyst component (a) after prepolymerization is continuously supplied as a catalyst to the first reactor so as to achieve a target production amount, and triethylaluminum is also used as a cocatalyst, which is also a catalyst only in the first reactor. It supplied continuously so that it might become a 5 molar ratio with respect to magnesium in. Further, tert-butylmethyldimethoxysilane as an electron donating compound was added to the first reactor only at 3.0 mol. ppm was fed continuously.
The operating conditions of each polymerization tank were as follows: the first reactor was a bulk polymerization with a temperature of 70 ° C., a pressure of 2.9 MPaG, a hydrogen concentration of 1.1 mol%, an average residence time of 0.6 hours, and the second reactor was Bulk polymerization with 67 ° C., pressure 2.6 MPaG, hydrogen concentration 0.6 mol%, average residence time 0.4 hour, third reactor 80 ° C., pressure 1.7 MPaG, average residence time 0.7 hour, hydrogen Gas phase polymerization at a concentration of 8.0 × 10 ⁻² mol%, the fourth reactor was carried out by gas phase polymerization at 80 ° C., pressure 1.1 MPaG, hydrogen concentration 0.1 mol%, average residence time 1.4 hours. It was.
As a result of this polymerization, a crystalline propylene polymer 5 having a catalytic activity of 35,000 gPP / gcat and an MFR of 0.47 g / 10 min was obtained. The MFR obtained in each stage was 0.50 g / 10 minutes from the first reactor, 0.55 g / 10 minutes from the second reactor, 0.55 g / 10 minutes from the third reactor, and from the fourth reactor. It was 0.47 g / 10 minutes [MFR ratio (MFR1 / MFR2) = 1.1].
The measured physical properties of the obtained crystalline propylene polymer 5 are shown in Table 1.

(Ii) Production of polypropylene resin composition 5 With respect to 100 parts by weight of crystalline propylene polymer 5, 0.1 part by weight of IRGANOX 1010, 0.2 part by weight of IRGAFOS 168 and 0.1 part by weight of calcium stearate are blended. The polypropylene resin composition 5 was obtained by melt-kneading and pelletizing using an extruder.
Thereafter, in the same manner as in Example 1, sheet forming and evaluation were performed. The results are shown in Table 1.

[Comparative Example 4]
(Ii) Production of crystalline propylene polymer 6 Polymerization was carried out using a continuous reaction apparatus in which two fluidized bed reactors having an internal volume of 230 liters were connected. First, in a first reactor, a polymerization temperature of 75 ° C., a propylene partial pressure of 1.8 MPa, and hydrogen as a molecular weight control agent are continuously added so that the hydrogen / propylene molar ratio becomes 1.1 × 10 ^−3. While feeding, triethylaluminum was fed at 5.25 g / hr and the solid catalyst component (a) was fed so that the polymer polymerization rate was 20 kg / hr. The powder polymerized in the first reactor (crystalline propylene polymer) was continuously withdrawn so that the amount of powder held in the reactor was 60 kg and transferred continuously to the second reactor (pre-stage polymerization step). .
Propylene is continuously supplied at a polymerization temperature of 80 ° C. so that the pressure becomes 2.0 MPa, and hydrogen as a molecular weight control agent is adjusted to a hydrogen / propylene molar ratio of 1.0 × 10 ^−2. And ethyl alcohol as an active hydrogen compound was supplied in an amount of 1.0-fold mol with respect to triethylaluminum. The powder polymerized in the second reactor is continuously extracted into the vessel so that the amount of powder held in the reactor is 40 kg, and the reaction is stopped by supplying nitrogen gas containing moisture to obtain a polypropylene resin. (Post polymerization process).
As a result of this polymerization, a crystalline propylene polymer 6 having a catalyst activity of 13,000 gPP / gcat and an MFR of 0.50 g / 10 min was obtained. The MFR obtained in each stage was 0.10 g / 10 min from the first reactor and 0.60 g / 10 min from the second reactor [MFR ratio (MFR1 / MFR2) = 0.2]. .
The measured physical properties of the obtained crystalline propylene polymer 6 are shown in Table 1.

(Iii) Production of polypropylene resin composition 6 With respect to 100 parts by weight of crystalline propylene polymer 6, 0.05 part by weight of IRGANOX 1010, 0.1 part by weight of IRGAFOS 168, 0.05 part by weight of DHT4A, and NA11 The polypropylene resin composition 6 was obtained by mix | blending 0.2 weight part, melt-kneading using an extruder, and pelletizing.
Thereafter, in the same manner as in Example 1, sheet forming and evaluation were performed. The results are shown in Table 1.

The following matters were found from the above examples and comparative examples.
(1) Examples 1 and 2 are examples of crystalline propylene polymers having extremely high rigidity and excellent heat resistance and drawdown resistance. In addition, the amount of the nucleating agent used can be reduced as compared with the prior art, and the manufacturing cost can be suppressed.
(2) Comparative Example 1 is an example of a crystalline propylene polymer having excellent drawdown resistance but low rigidity. From the comparison with Examples 1 and 2, the bending elastic modulus is low, and it is difficult to apply to fields that require high rigidity such as an automobile deck board. In addition, it has a low melting point and is difficult to apply to fields requiring heat resistance.
(3) Comparative Example 2 is an example of a crystalline propylene polymer having low melt viscoelasticity and further low rigidity. From comparison with Examples 1 and 2, the drawdown resistance is poor and the flexural modulus is also low. Furthermore, it has a low melting point and is difficult to apply to fields requiring heat resistance.
(4) Comparative Example 3 is an example of a crystalline propylene polymer having high rigidity but low melt viscoelasticity. From comparison with Examples 1 and 2, it is clear that the drawdown resistance is poor.
(5) Comparative Example 4 is an example of a crystalline propylene polymer having slightly low melt viscoelasticity and rigidity. Despite the large amount of nucleating agent used, the flexural modulus is low as compared with Examples 1 and 2. In addition, since the method of producing high molecular weight polypropylene in the former stage and low molecular weight polypropylene in the latter stage, the production efficiency is poor, and fish eyes (FE) are more likely to occur.

  The crystalline propylene polymer of the present invention is extremely high in rigidity, and further excellent in heat resistance and drawdown resistance, and therefore suitable for production of a molded product by a thermoforming method such as a vacuum forming method or a pressure forming method, It can be used and has high industrial applicability.

Claims (5)

A method for producing a crystalline propylene polymer satisfying the following characteristics (a) to (c):
Manufactured by multi-stage polymerization of two or more stages including a bulk polymerization process and a gas phase polymerization process, and the melt flow rate (MFR) of the polymer obtained in each stage is sequentially reduced and manufactured in a first-stage reaction tank. A method for producing a crystalline propylene polymer, wherein the MFR ratio of the MFR (MFR1) of the polymer and the MFR (MFR2) of the crystalline propylene polymer is represented by the following formula .
MFR1 / MFR2> 4.0
(A) Temperature at which the 40 ° C. soluble fraction (40 ° C. sol.) Is 1% by weight or less and the amount of the eluted component is the highest in the measurement of temperature rising elution fractionation (TREF) using orthodichlorobenzene as a solvent (Tp) is in the range of 113 to 125 ° C.
(B) The value of the storage elastic modulus at the intersection Gc between the frequency ω dependency curve G ′ (ω) of the storage elastic modulus and the frequency ω dependency curve G ″ (ω) of the loss elastic modulus by dynamic viscoelasticity measurement ( unit: when the 10 ^five times the reciprocal of Pa) was the PI, is PI of 4.0 or more.
(C) The melt flow rate (MFR2) measured according to JIS K7210 (230 ° C., 2.16 kg load) is 0.2 to 0.8 g / 10 min.   The method for producing a crystalline propylene polymer according to claim 1, wherein the crystalline propylene polymer is produced by multistage polymerization of four or more stages. The crystalline propylene according to claim 1 or 2 , wherein a propylene polymerization catalyst comprising a solid catalyst component (A) containing titanium, magnesium and halogen as essential components and an organoaluminum component (B) is used. A method for producing a polymer. The method for producing a crystalline propylene polymer according to claim 3 , wherein the propylene polymerization catalyst further contains the following polymerization additive (C).
Polymerization additive (C): an organosilicon compound containing two or more Si—OR ¹ bonds (provided that R ¹ is a hydrocarbon group having 1 to 8 carbon atoms) The crystalline propylene polymer according to claim 3 or 4 , wherein the solid catalyst component (A) is obtained by contacting the following components (i), (ii), (iii) and (iv): Manufacturing method.
(I) Solid component containing titanium, magnesium and halogen as essential components (ii) Organosilicon compound containing two or more Si—OR ¹ bonds (where R ¹ is a hydrocarbon residue having 1 to 8 carbon atoms) is there.)
(Iii) Vinylsilane compound (iv) Organometallic compound of periodic group I-III metal

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