JPH0931266A - Polyethylene-based resin material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyethylene-based resin material having high rigidity, heat resistance and transparency. SOLUTION: This polyethylene-based resin material is obtained by converting at least a part of fl crystal of a polyethylene-based resin composition which has >=5% β crystal fraction measured by using a press molded article isothermally crystallized at 30 deg.C and satisfies the following equation β(30)>β(100) when βcrystal contents isothermally crystallized at 30 deg.C and 100 deg.C are β(30) and β(100), respectively, and has 0.05-1,000g/10 minutes melt flow rate, into α crystal. The polyethylene-based resin material is useful as a material for a structural material suitable for various molding, etc., and as a substitute for an engineering plastic.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene resin material excellent in rigidity, heat resistance and transparency and a method for producing the same.

[0002]

2. Description of the Related Art Isotactic crystalline polypropylene (hereinafter abbreviated as PP) is relatively inexpensive and
It has excellent rigidity, surface gloss, and heat resistance, but the crystallinity does not increase sufficiently under normal crystallization conditions (70% or less).
Therefore, the rigidity and heat resistance are not sufficient to substitute for so-called engineering plastic, which is expensive and difficult to recycle. Therefore, many attempts have been made to use a filler such as talc or glass fiber for the purpose of improving the rigidity and heat resistance of the PP material, but the same molded product becomes heavier due to the increase in density, and the appearance deteriorates. Therefore, the material is not quantitatively limited and a satisfactory material is not obtained. In addition, for the purpose of PET substitution, etc., studies have been made using copolymerization of comonomers, transparent nucleating agents, etc., but none have yet been obtained that satisfy the balance between transparency and rigidity.

[0003]

The crystal part of PP has many crystal systems such as α crystal, β crystal, γ crystal and smectic crystal, and the molecular structure of PP, the presence of a crystal nucleating agent, Their amount changes depending on the crystallization conditions. Further, among these, α crystal is known to be the most stable and excellent in heat resistance among PP crystals. Therefore, in order to industrially improve the rigidity and heat resistance of PP, α crystal nucleating agents have been used, but sufficient rigidity and heat resistance have not been fully exhibited. The present invention has been made to solve the above problems, and provides a polypropylene resin material having high rigidity, heat resistance, and transparency, and a method for producing the same.

[0004]

According to the first aspect of the present invention,
The β crystal fraction measured by using a press-molded product that has been isothermally crystallized at 30 ° C. is 5% or more, and 30 ° C. and 100 ° C.
The β crystal content of each crystal is isothermally crystallized by β (30)
And β (100), the formula (1) is satisfied, and the formula (1) β (30)> β (100) and the polypropylene resin composition having a melt flow rate of 0.05 to 1000 g / 10 min. A method for producing a polypropylene-based resin material, which comprises converting at least a part of β crystal to α crystal. The invention according to claim 2 is 70 to 99.5% by weight of a polypropylene resin having a melt flow rate of 0.05 to 1000 g / 10 minutes, and the following (a):
And β obtained by melt-kneading the polypropylene resin having the physical properties of (b) with 0.5 to 30% by weight of a resin which has been treated to generate a peroxide radical, in a state in which the peroxide radical is not deactivated before melting. A method for producing a polypropylene resin material, which comprises converting at least a part of β crystals of a polypropylene resin composition having a crystal fraction of 5% or more into α crystals. (A) Melt flow rate is 5 g / 10 minutes or less (b) Isotactic pentad fraction (abbreviated as IP)
And the melt flow rate (abbreviated as MFR) have a relationship of (Equation 2) (Equation 2) IP> 0.0428 × log (MFR) +0.97

Here, it is desirable that the β crystal fraction be 2% or less by converting at least part of the β crystal into α crystal. Further, it is desirable to carry out the conversion by adding an α crystal nucleating agent. Further, the polypropylene resin composition preferably has an isotactic pentad fraction of the propylene chain of 0.970 or more. Further, the addition amount of the α crystal nucleating agent is preferably 0.01 to 30 parts by weight with respect to 100 parts by weight of the polypropylene resin composition. As the α crystal nucleating agent, an alkali metal salt is suitable. Furthermore, as the alkali metal salt, a phosphate alkali metal salt is suitable. Furthermore, as the alkali metal salt thereof, sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate is preferable.

The polypropylene resin material of the present invention is characterized by being obtained by these production methods. At this time, the polypropylene resin material has a melt flow rate (MFR) of 0.05 to 1000 g / 10 minutes, M
It is desirable that FR and the ratio of the endothermic amount ΔHm at the time of melting measured by the differential scanning calorimetry and the exothermic amount ΔHc at the time of crystallization satisfy (Equation 3). (Equation 3) ΔHm / ΔHc> 0.00007915log (MFR) +1.032

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is intended to obtain a polypropylene resin material having extremely excellent rigidity, heat resistance and transparency by controlling the crystal structure of the polypropylene resin. The α-crystal PP has excellent rigidity and heat resistance, while the β-crystal PP has a lower melting point than the α-crystal, and the higher the β-crystal fraction, the smaller the energy during melt molding of the resin and the better the moldability. Therefore, taking advantage of the respective characteristics of α crystal and β crystal, a large amount of β crystal is included before molding such as injection molding to improve moldability, and β crystal is converted to α crystal during or after molding, High rigidity and high heat resistance of molded products. When β crystal is once formed with β crystal nucleating agent and then recrystallized to α crystal by Self-Seeding method, nucleation during crystallization is promoted more than when starting from the same α crystal. (Ref: Lotz et al. (Fillon et.al., J. Polym. Sci. B, 31, 1407 (1993))).
Therefore, in the present invention, the increase of the nuclei makes the crystals finer and improves the transparency. By the way, the β crystal is converted to the α crystal by stretching, but the β crystal is more unstable than the α crystal, and therefore it is energetically advantageous to stretch from this state. As a practical method for forming a large amount of β crystals, a method using a β crystal nucleating agent is known (Japanese Patent Laid-Open No. 6-1892).
JP-A-6-107875), the presence of a β-crystal nucleating agent in these methods causes problems such as coloring, and even when the α-crystal nucleating agent is used, the β-crystals are converted to α-crystals. However, the present invention can avoid these inconveniences.

The present invention is to obtain a polypropylene resin material by converting β crystal of a specific polypropylene resin composition containing 5% or more of β crystal into α crystal. In the present invention, the polypropylene resin composition which is the base of the polypropylene resin material has a β crystal fraction of 5% or more. More preferably 15% or more, still more preferably 20
% Or more, more preferably 30% or more. By having the β crystal in an amount of 5% or more, energy during melt molding is small and moldability is excellent. On the other hand, if it is less than 5%, even if all the β crystals are converted to α crystals, the amount of crystal conversion from β crystals to α crystals is small, and a sufficient effect of improving the physical properties does not appear. Here, the β crystal fraction refers to the ratio of β crystals in the entire crystal part of the polypropylene resin composition. Unless otherwise specified, the β crystal fraction is measured for a press molded product (press sheet) crystallized isothermally at 30 ° C. The press-molded product was 0.5 mmt, and was preheated at 230 ° C. for 5 minutes using a dedicated mold of 10 cm × 10 cm, degassed, pressurized at 60 kg / cm ² for 5 minutes, and then cooled at 30 ° C. 10 minutes 60
It is prepared by pressurizing at kg / cm ² . To obtain the β crystal fraction, first, an X-ray generator (Rika Denshi Co., Ltd.
(U-200) using a CuK line monochromated with a Ni filter, under the conditions of 50 kV and 150 mA, the scattering angle (2
The X-ray profile is measured in the range of θ) of 10 to 30 °. To calculate the β-crystal fraction, A. Turner Jones et al; Mac was used after correcting the air scattering in the obtained scattering profile.
Calculated according to the method described in romol. Chem. 75, 134 (1964). That is, the peak heights corresponding to the scattering of the (110), (040), (130), and (300) crystal parts of the α crystal after subtracting the scattering of the amorphous part are h [ α] (110), h [α] (040), h
[Α] (130) and h [β] (300), and the β crystal fraction (k) was calculated from the following formula. k = h [β] (300) / (h [α] (110) + h [α] (040) + h [α]
(130) + h (β) (300))

In the invention of claim 1, the polypropylene-based resin composition has a β crystal content of β (3) when isothermally crystallized (press molding) at 30 ° C. and 100 ° C., respectively.
(0) and β (100), (Equation 1) is satisfied. (Equation 1) β (30)> β (100) That is, the press-formed product is 0.5 mmt and 10 cm ×
After preheating for 5 minutes at 230 ° C using a dedicated 10 cm die, degassing and pressurizing at 60 kg / cm ² for 5 minutes, then 30 ° C and 10
60 kg / for 10 minutes each using a 0 ° C cooling press
When measuring the β crystal content of two types of molded products produced by pressurizing with cm ² , it is necessary that the β crystal content at 30 ° C. is higher than the β crystal content at 100 ° C. Satisfying this (Equation 1) means that higher β crystals are produced when molding is performed at a low temperature, and a primary molded product having a high β crystal fraction is obtained by molding at a low temperature. This means that β crystals are unlikely to form at high temperatures. This is a characteristic that conventional polypropylene resins do not have. Although details are not clear, as a result, the heat treatment and stretching of the β crystal of the temporary molded product obtained from this, the conversion to the α crystal by melting and kneading the nucleating agent (which is performed at a relatively high temperature) are further promoted, and the final It is thought that this leads to the effect of improving the physical properties of the molded product.

The invention according to claim 2 has an MFR of 0.05.
Polypropylene resin ((A
1) component) and a polypropylene resin having the following physical properties (a) and (b) that is treated to generate peroxide radicals (referred to as component (A2)) before melting the peroxide radicals. It is melt-kneaded without being deactivated. The polypropylene-based resin used as the component (A1) and the component (A2) in the present invention should have a high stereoregularity, and the catalyst system for obtaining the same is not particularly limited. However, when a Ziegler-based catalyst is used, it has a particularly high stereoregularity. It is preferred to use a specific magnesium supported catalyst system. The method of generating a peroxide radical is not particularly limited, but ionizing ray irradiation, particularly γ-ray irradiation is preferable.

The polypropylene resin as the component (A1) in the present invention is mainly homopolypropylene or propylene, and a small amount (10% by weight or less of the whole amount) of ethylene, butene-1, pentene-1, etc. -Random copolymers with olefins, or block copolymers with propylene and α-olefins such as ethylene and butene-1. In the block copolymer, it is preferable that the proportion of the copolymer rubber component of propylene and other α-olefin in the copolymer is 5 to 80% by weight,
The propylene content in the rubber component is preferably 30 to 70% by weight. These may be used alone or in combination of two or more. The polypropylene resin as the component (A1) has an MFR of 0.05 to 1000 g / 10 minutes, preferably 0.1 to 500 g / 10 minutes. MF
When R is less than 0.05 g / 10 minutes, the moldability is poor, while 10
If it exceeds 00 g / 10 minutes, a β crystal fraction of 5% or more cannot be obtained. The stereoregularity of the polypropylene chain of the component (A1) of the present invention is not particularly limited, but a polypropylene resin having a high stereoregularity gives more preferable results.

As one of the methods for obtaining the polypropylene resin treated to generate the peroxide radical of the component (A2) of the present invention, the polypropylene resin having the following physical properties (a) and (b) is subjected to γ-ray treatment. There is a method. (A) Melt flow rate (MFR) 5 g / 10 minutes or less (b) Isotactic pendat fraction (IP) and MF
R has the relationship of (formula 2) (formula 2) IP> 0.0428 × log (MFR) +0.97 (A2) MF of polypropylene resin used for component
The reason for setting R to 5 g / 10 min or less is that if the MFR exceeds 5 g / 10 min, a β crystal fraction of 5% or more cannot be obtained. Further, if the relationship between IP and MFR does not satisfy the above equation, the β crystal fraction of 5% or more cannot be obtained. In addition, IP means an isotactic fraction in a pendad unit in a polypropylene molecular chain measured by using nuclear magnetic resonance ( ¹³ C-NMR) with an isotope, and the measuring method is A.
Zambelli; Macromolecules, 6, 925 (1973), ibid, 8,687,
(1975), 13,267 (1980) for detailed description. That is, it is the isotactic fraction in pentane units in the polypropylene molecular chain measured using ¹³ C-NMR, and is the fraction of propylene monomer units in which five propylene monomer units are isotactically bonded in succession. Means

As a method for obtaining a polypropylene resin satisfying the above (formula 2), for example, a solid catalyst containing a magnesium compound, a titanium compound, a halogen-containing compound and an electron donating compound as essential components is further used as a catalyst of the general formula TiXa. Yb (in the formula, X is a halogen atom of Cl, Br, I, Y is an electron-donating compound such as diisobutyl phthalate or diisobutyl maleate, a is an integer of 3 or 4, and b is an integer of 3 or less. Examples of the highly stereoregular polypropylene-based resin obtained by polymerizing using a polymerization catalyst obtained by treating with a halogen-containing compound after treatment with a titanium compound represented by each of the above) and further washing with a hydrocarbon. The polypropylene-based resin is mainly homopolypropylene or propylene, and is a random copolymer with a small amount (10% by weight or less of the total) of α-olefin such as ethylene, butene-1, pentene-1, or the above-mentioned propylene. A block copolymer with an α-olefin such as ethylene or butene-1 is selected. These polypropylene resins may be used alone or in combination of two or more.

The polypropylene resin as the component (A2) of the present invention is obtained by subjecting the polypropylene satisfying the above (a) and (b) to a treatment for generating a peroxide radical. As a component (A2), a polypropylene resin having an MFR of 5 g / 10 minutes or less is treated to generate a peroxide radical, and the component (A1) and the generated peroxide radical are melt-mixed in a state in which they are not deactivated before melting. When the polypropylene resin composition is obtained, the β crystal content of polypropylene is 5% or more. The lower the MFR and the higher the isotactic pentad fraction (IP), the higher the β crystal fraction when melt-mixed with the component (A1) to form a primary molded product,
If the above relational expression of MFR and IP is satisfied, a higher β crystal fraction can be obtained. For example, MFR = 4g /
10 minutes IP = 0.996 or more, MFR = 3.0 g / 10 minutes IP = 0.990 or more, MFR = 2.0 g / 10 minutes IP
= 0.983 or higher, and MFR = 1.5 g / 10 min IP
= 0.978 or more.

The component (A2) of the present invention is preferably obtained by γ-irradiating polypropylene polymer powder or pellets in air or in an inert gas atmosphere containing 1% or more of active oxygen. It is preferably at least 3%, more preferably at least 5%. If the above conditions are not satisfied, a polypropylene resin composition having a β crystal content of 5% or more, which is a feature of the present invention, cannot be obtained. Irradiation dose is 5-100
kGy, preferably 8-80 kGy, especially 1
0 to 70 kGy is preferable. This is because if it is less than 5 kGy, the β crystal fraction cannot be increased. 100kGy
If it is 100 kGy or more, molecular weight cleavage occurs and gel tends to occur.
It is important that the polypropylene resin which is the component (A2) has a peroxide radical after γ-ray irradiation. This is observed from ESR measurements, as shown in FIG.
The ESR is a well-known device for detecting radicals contained in a sample, and the principle thereof is described in, for example, an introduction to electron spin resonance (M. Bersohn, JC Baird, N. Fujiwara, N. Watanabe,
Tokyo chemistry coterie). Further, the interpretation of the spectrum is shown in, for example, electron spin resonance (Hiroaki Ohya, Atsushi Yamauchi, Kodansha Scientific).

As shown in FIG. 4, the peroxide radicals are inactivated by heat treatment or the like, so that the peroxide radicals may be mixed with the component (A1) without being inactivated. is important. The composition ratio of the component (A2) in the total amount of the polypropylene resin composition composed of the component (A1) and the component (A2) of the present invention is 0.5 to 30% by weight.
And preferably 1 to 20% by weight, especially 3 to 15
% By weight is preferred. If the proportion of the component (A2) is less than 0.5% by weight, a polypropylene resin composition having a β crystal fraction of 5% or more cannot be obtained. On the other hand, if it exceeds 30% by weight, the cost becomes high, which is not preferable. A method for obtaining a polypropylene resin composition comprising the above component (A1) and the above component (A2) in the present invention will be described. First, (A1) component and (A2)
Melt and knead the ingredients. Specifically, for example, after performing dry blending using a mixer such as a Henschel mixer, a tumbler, or a ribbon mixer, melt mixing is performed using a Banbury, a kneader, or an extruder. As the extruder, either a single screw extruder or a twin screw extruder may be used. The temperature for melt mixing is generally 170 to 300 ° C, and preferably 180 to 280 ° C.

After the melt-kneading, cooling is performed in the temperature range of -15 to 120 ° C. The lower the cooling temperature, the better, preferably -15 to 60 ° C, more preferably -15 to 40 ° C. The lower the cooling temperature, the higher the β crystal production rate. Further, at this time, it is desirable to perform cooling in a state where the molecular orientation is as small as possible. Examples of the method for performing crystallization in a state with little orientation include press molding and extrusion molding. In order to cool the resin melt-kneaded in the extruder to obtain the intended polypropylene resin composition, it is preferable that the extrusion speed is slow so that orientation is not applied as much as possible. Although a suitable extrusion rate varies depending on the type of extruder, it is preferable to perform the extrusion rate such that orientation is not applied. The polypropylene resin composition obtained by the above method has an MFR of 0.05.
~ 1000 g / 10 min.

Further, in order to obtain a desired polypropylene resin material having high rigidity, high heat resistance and high transparency, the isotactic pentad fraction (IP) of the propylene chain of the above polypropylene resin composition is used. Is 0.970
The above is desirable. It is preferably 0.975 or more, more preferably 0.980 or more. IP is 0.9
When it is 70 or less, a molded product having sufficient rigidity, heat resistance and transparency cannot be obtained. The polypropylene resin composition in the present invention refers to a material composed of the component (A1) and the component (A2), and may be in the form of pellets, sheets or any other form. The polypropylene resin composition of the present invention may optionally contain various conventional additives such as antioxidants, weather resistance stabilizers, antistatic agents, lubricants, antifog agents, as long as the β crystal content is 5% or more. , Electrical property stabilizers, processing improvers, pigments, softeners and the like can be added within a range that does not impair the object of the present invention. In addition, when a low MFR (A1) component is used,
Based on low MFR polypropylene resin (A
2) When the component is added in a small amount, the MFR of the composition hardly changes, or rather decreases. The suppression of the decrease in the molecular weight becomes more remarkable by the addition of magnesium oxide, zinc oxide or the like.

The polypropylene-based resin composition of the present invention is a pellet-shaped product obtained by melt-kneading the polypropylene-based resin as the component (A1) and the component (A2), a product obtained by press-molding once, and a product shape. It may be in various forms such as injection molded. As a method of converting the β crystal of the polypropylene resin composition into the α crystal, a method of adding an α crystal nucleating agent to the polypropylene resin composition,
There are a method of heat-treating to form a molded body as it is, a method of stretching, and the like. The method of heat-treating to form a molded body as it is is preferably carried out at a temperature of 130 ° C. or higher in an oven or the like and lower than the melting temperature. As a stretching method, any stretching method usually used in industry (spinning, roll stretching, uniaxial and biaxial stretching, inflation molding, etc.) can be applied.

The α-crystal nucleating agent of the present invention will be described below. The α crystal nucleating agent is a polymer compound such as polyethylene, polypropylene having a long chain branch, poly-3-methylbutene-1, poly-4-methylpentene-1. Also, talc, calcium carbonate, lithium carbonate, mica,
Aluminum borate, potassium titanate, basic magnesium sulfate, sodium benzoate, aluminum-
a metal salt of a carboxylic acid such as p-t-butylbenzoate,
1,3,2,4-dibenzylidene sorbitol, 1,
3,2,4-bis (p-methylbenzylidene) sorbitol, 1,3,2,4-bis (p-ethylbenzylidene) sorbitol, 1,3-p-chlorobenzylidene-
Dibenzylidene sorbitol derivatives such as 2,4-p-methylbenzylidene sorbitol, sodium-
2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate, sodium-2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, sodium- Bis (4-t-butylphenyl) phosphate, sodium-bis (4-t-methylphenyl) phosphate, potassium-bis (4,6)
It is effective to use an alkali metal salt such as a phosphate alkali metal salt such as -di-t-butylphenyl) phosphate. For improving rigidity, a phosphate alkali metal salt is preferable, and sodium-
It is preferable to use 2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate. A sorbitol-based nucleating agent is preferably used for improving transparency.

The method for obtaining the polypropylene resin composition comprising the polypropylene resin composition and the α-crystal nucleating agent according to the present invention is a known method, for example, when it is obtained by melt-kneading with an extruder, it is uniaxial or biaxial. Any extruder may be used. The β-crystal in the polypropylene-based resin composition is converted into the α-crystal by melt-mixing the polypropylene-based resin composition and the α-crystal nucleating agent. The α-crystal nucleating agent may be added to the polypropylene resin composition as it is, or if necessary, a masterbatch prepared by kneading with a small amount of polypropylene resin may be added. To be more effective,
The α crystal nucleating agent is preferably added in an amount of 0.01 to 30 parts by weight based on 100 parts by weight of polypropylene after β crystal formation of the polypropylene resin. Below 0.01 parts by weight,
The effect is small, and when the amount is 30 parts by weight or more, the dispersion becomes poor, which is not preferable. More preferably, it is 0.05 to 20 parts by weight.

At least a part of the β crystal of the polypropylene resin composition, that is, a part or all of the β crystal is converted to an α crystal to be a constituent element of the polypropylene resin material of the present invention. Further, the β crystal content of the polypropylene resin composition is preferably 2% or less after conversion, and more preferably 1% or less. If it is 2% or less, the physical properties, rigidity, heat resistance, and transparency of the polypropylene resin material finally obtained will be better. In addition, α crystal of polypropylene has crystal forms of α ₁ and α _2.
2 is known to be more stable. Many crystal forms indicate high rigidity and high heat resistance.

The polypropylene resin material obtained in the present invention is preheated at 230 ° C. for 5 minutes by using a dedicated mold of 18 mm × 20 mm with a thickness of 2 mmt, and then degassed to 30 ° C.
The intensity of scattering (I ₂₎ derived from α ₂ and α ₁ when measured by X-ray when a sample produced by pressurizing with a cooling press at 50 kg / cm ^{2 for} 5 minutes was annealed at 160 ° C. for 2 hours. ) And the intensity R of the scattering (I ₁ ) derived from α ₁
= I ₂ / I ₁ (R is a measure of the amount of α ₂ ) is 1 or more. It is preferably 1.1 or more.
X-ray scattering profile is X-ray manufactured by Rika Electric Co., Ltd.
It measured using the CuK line monochromated by the Ni filter of the line generator (RU-200). The standard R of the amount of α ₁ to α ₂ is G. Guerra, V. Petraccone, P. Corradini,
C. De Rosa, R. Napoliano, and B. Pirozzi, J. Polm.
Sci., Polm. Phys. Ed., Vol. 22, 1029 (1984) was used for the following determination. That is, after drawing a baseline on the X-ray profile measured using CuK line according to FIG.
of the integrated intensity of the scattering between θ = 33.4 ° and 36.0 ° (from α ₁ and α ₂ ) I ₂ and the scattering between 2θ = 36.4 ° to 38.0 ° (from α ₁ only) The integrated intensity I ₁ was determined. The ratio R = I ₂ / I ₁ was used as an index of the amount of α ₂ .

In the polypropylene resin material of the present invention, the MFR (g / 10 minutes) determined based on JIS K-7210, Table 1, Condition 14 and the differential scanning calorimetry (20 ° C.)
/ Min) Endothermic amount (ΔHm (J / g)) when melted
And the heat generation amount (ΔHc (J / g)) during crystallization (ΔH
It is desirable that m / ΔHc) satisfy the following equation (Equation 3). (Equation 3) ΔHm / ΔHc> 0.00007915log (MFR) +1.032 The calorific value (ΔHc) during crystallization is relatively small compared to the endothermic value (ΔHm) at the time of melting obtained under these specific conditions. In the crystallization behavior of the composition of the present invention, there are more portions that cannot be detected by the above-mentioned differential scanning calorimetry, and as a result, the crystallization behavior of the composition of the present invention is affected. It seems to be one of the reasons why the physical properties are improved.

When the polypropylene-based resin composition of the present invention is obtained, if the polypropylene-based resin composition is in the form of pellets that have been melt-kneaded, or a product that has been press-molded once and then cut, etc. It is possible to use all additives such as a thermo-oxidative stabilizer, a nucleating agent other than the above, a light stabilizer, an antistatic agent, a lubricant, etc., which are blended with an ordinary polypropylene resin before obtaining a resin material. Further, it may be partially modified with a radical initiator such as a peroxide or a modifier such as an unsaturated carboxylic acid within a range satisfying the conditions. Furthermore, various polyethylene, polybutene, ethylene-propylene copolymers, olefin-based copolymers such as ethylene-butene copolymers, block copolymers having ethylene blocks and ethylene-butene blocks (hydrogenated-butadiene-
Block copolymer), a block copolymer having a block of styrene block and ethylene-butene (hydrogenated-styrene-butadiene-block copolymer), talc, calcium carbonate, lithium carbonate, mica, It is also possible to mix and use an inorganic filler such as glass fiber, aluminum borate, potassium titanate, or basic magnesium sulfate. Further, the above addition, modification or mixing may be carried out at the stage of obtaining the polypropylene resin composition.

[0026]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited to these examples. In addition, the measurement of various physical properties,
The procedure was as follows.

(1) Measurement of Isotactic Pentad Fraction (IP) Using the data obtained by ¹³ C-NMR, the above A.Za
It was calculated by the method of mbelli et al. (Macromolecules, 6,925 (1973)). (2) MFR JIS K-7210, Table 1, Condition 14 (Test temperature 23
It was measured at 0 ° C. and a test load of 2.16 kgf). (3) Flexural modulus Measured by ASTM D790. (4) Measured by HDT ASTM D648. (5) Measurement of haze (haze value) The haze (haze value) was measured using a press-molded product. The press-molded product is 0.5 mmt, and a dedicated mold of 10 cm × 10 cm is used. After preheating at 230 ° C. for 5 minutes, it is degassed to 60 kg /
After pressurizing at cm ² for 5 minutes, use a cooling press at 30 ° C for 5 minutes.
Made by pressurizing at 60 kg / cm ² for minutes, JIS K-7
According to 105, it was determined by a haze meter manufactured by Suga Test Instruments Co., Ltd.

(6) β Crystal Fraction Measurement (X-ray Diffraction Method) As the X-ray source, a Cuk ray obtained by a Rigaku Denki X-ray generator (RU-200) monochromated with a Ni filter was used. , 50KV, 150mA, scattering angle (2
The X-ray scattering profile of the sample was determined in the range of θ) = 10 to 30 deg. The β-crystal fraction was calculated by correcting the obtained scattering profile for air scattering and then
l. Chem. 75,134 (1964). The measurement was performed using a press-molded product as a sample. The press-molded product is 0.5 mmt, using a dedicated 10 cm x 10 cm die, preheated at 230 ° C for 5 minutes, degassed, pressurized at 60 kg / cm ² for 5 minutes, and then cooled at 30 ° C and 100 ° C. Was applied for 10 minutes at a pressure of 60 kg / cm ² .
Unless otherwise specified, the β crystal fraction refers to the value of that produced at 30 ° C. Further, the β crystal fractions of the films manufactured at 30 ° C. and 100 ° C. were designated as β (30) and β (100), respectively. (7) ESR measurement The measurement was performed using Jeol JES-FE1XG manufactured by JEOL Ltd., X-B
A granular resin was put into a sample tube for ond (made of quartz), and the measurement was performed at room temperature in air with a magnetic field of 3360 G and 100 G and a magnetic field sweep width. Frequency of modulating magnetic field is 100 kHz
z, the size is 6.3 G, and the response is 0.01 seconds.

(8) Measurement of R = I ₂ / I ₁ (R: index of amount of α ₂ ) The sample for measurement has a thickness of 2 mmt and is 18 mm × 20 mm.
After preheating at 230 ° C for 5 minutes using the special mold of
It was prepared by applying a pressure of 50 kg / cm ^{2 for} 5 minutes using a 30 ° C. cooling press. The X-ray scattering profile is
The measurement was carried out using CuK rays monochromated with a Ni filter of an R-200 X-ray generator (RU-200). As described above, the guideline for the amount of α ₁ to α ₂ is G. Guerra,
V. Petraccone, P. Corradini, C. De Rosa, R. Napolian
o, and B. Pirozzi, J. Polm. Sci., Polm. Phys. Ed.,
It was calculated according to the reference of Vol. 22, 1029 (1984). (9) Differential Scanning Calorimetry (DSC) Using DSC7 manufactured by Perkin Elmer, about 4 mg of a film-shaped sample was held at 230 ° C. for 5 minutes, and then 3
The temperature was lowered to 0 ° C at 20 ° C / min. Then, after holding at 30 ° C. for 5 minutes, the temperature was raised at 20 ° C./minute. ΔHc (J /
As shown in FIG. 1, g) is the temperature (Tcs) at which heat generation starts in the curve corresponding to the heat generation amount obtained when the temperature is lowered.
(° C.)) and a temperature 40 ° C. lower than the Tsc are connected by a straight line (baseline), and the area S ₁ surrounded by the baseline and the calorific value curve is integrated and obtained. ΔHm (J
/ G) is the temperature (Tm) at which the heat absorption ends in the curve corresponding to the heat absorption amount obtained at the time of temperature rise, as shown in FIG.
e (° C.)) and a temperature 65 ° C. lower than Tme are connected by a straight line (base line), and the area S ₂ surrounded by the base line and the endothermic curve is integrated to obtain.

[Preparation of Polymer] Preparation of Solid Catalyst Component (Step 1) Preparation of Solid Component 47.6 g (50) of anhydrous magnesium chloride under a nitrogen atmosphere.
0 mmol), 259 ml of decane and 234 ml of 2-ethylhexyl alcohol (1.5 m
ol) is heated at 130 ° C. for 2 hours to form a uniform solution, and 11.1 g (75 mm) of phthalic anhydride is added to this solution.
ol) was added, and the mixture was further stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride in the homogeneous solution. After cooling the obtained homogeneous solution to room temperature, the whole amount was added dropwise to 2.0 liters (18 mol) of titanium tetrachloride kept at -20 ° C over 1 hour. After the dropping, the temperature of the mixed solution was raised to 110 ° C. over 4 hours, and when it reached 110 ° C., 26.8 ml of diisobutyl phthalate (1
25 mmol) was added, and the mixture was reacted with stirring at 110 ° C. for 2 hours. After completion of the reaction, a solid component was collected by hot filtration, and then 2.0 l of titanium tetrachloride (18
(mol) was suspended and treated at 110 ° C. for 2 hours. After the treatment was completed, the solid component was collected again by hot filtration and washed with 2.0 liters of decane at 110 ° C. seven times and 2.0 liters of hexane at room temperature three times.

(Step 2) TiCl ₄ [C ₆ H ₄ (COO ⁱ C
Preparation of ₄ H ₉ ) ₂ ] Into a solution of 1.0 liter of hexane containing 19 g (100 mmol) of titanium tetrachloride, 27.8 g of diisobutyl phthalate was added.
(100 mmol) was added dropwise for about 30 minutes while maintaining 0 ° C. After completion of the dropping, the temperature was raised to 40 ° C. and the reaction was performed for 30 minutes. After the reaction was completed, the solid component was collected and washed 5 times with 500 ml of hexane to obtain the desired product. (Step 3) Treatment with TiCl ₄ [C ₆ H ₄ (COO ⁱ C ₄ H ₉ ) ₂ ] 40 g of the solid component obtained in the above step 1 was added with toluene 600
Suspend in milliliters and mix with TiCl ₄ [C ₆ H ₄ at 25 ° C.
(COO ⁱ C ₄ H ₉ ) ₂ ] 10.3 g (22 mmol) and 1
Allowed to react for hours. After completion of the reaction, 200 ml (1.8 mol) of titanium tetrachloride was added, and the reaction was carried out at 110 ° C for 2 hours. After completion of the reaction, a solid component was collected by hot filtration, and then 600 ml of toluene and 200 ml of titanium tetrachloride (1.8 mol) were added to the reaction product.
Was suspended and then reacted at 110 ° C. for 2 hours. After the completion of the reaction, the solid component was collected again by hot filtration and washed with 1.0 liter of toluene at 110 ° C. seven times and with 1.0 liter of hexane at room temperature three times.

Preparation of Prepolymerization Catalyst Component Under an atmosphere of nitrogen, 500 ml of n-heptane, 6.0 g (0.053 mol) of triethylaluminum and 3.1 g (0 0.017 mol) and 100 g of the solid catalyst component obtained above were added, and the mixture was stirred at a temperature range of 0 to 5 ° C for 5 minutes. Next, 1 g of solid component
Propylene was fed into the autoclave so that 0 g of propylene was polymerized, and prepolymerized in the temperature range of 0 to 5 ° C for 1 hour. The obtained prepolymerized catalyst was washed 3 times with 500 ml of n-heptane and used for the following polymerization.

[Polymerization of Propylene (Component A1)] (PP-1) Polymerization was carried out in the following manner using an autoclave equipped with a stirrer and having an internal volume of 60 liters in a nitrogen atmosphere. Prepolymerization catalyst component prepared by the above method 2.
0 g, triethylaluminum 11.4 g (100 mm
ol), t-butyltrimethoxysilane 5.9 g (33
mmol), and then supply 18 kg of propylene and hydrogen so that the MFR of the polymer becomes 0.5 g / 10 minutes,
Polymerization was carried out at 70 ° C. for 30 minutes. Unreacted gas was purged to obtain the target polypropylene. The isotactic pentad fraction of PP was 0.994. P obtained
The MFR of P was 0.5 g / 10 minutes. (PP-2) Tosoh Akzo AA type titanium trichloride 6
g, diethyl aluminum chloride 23.5 g as a catalyst component, propylene 18 kg, polymer MF
Hydrogen was supplied so that R was 0.5 g / 10 minutes, and polymerization was carried out at 85 ° C. for 30 minutes. Unreacted gas was purged to obtain the target polypropylene. The isotactic pentad fraction of PP was 0.941. MF of the obtained PP
R was 0.5 g / 10 minutes.

(PP-3) Polymerization was carried out in the following manner using an autoclave equipped with a stirrer and having an internal volume of 60 liters in a nitrogen atmosphere. 2.0 g of prepolymerized catalyst component prepared by the above method, 11.4 g of triethylaluminum
(100 mmol) and 5.9 g (33 mmol) of t-butyltrimethoxysilane, and then propylene 1
8 kg, hydrogen was supplied so that the MFR of the polymer would be 30 g / 10 minutes, and polymerization was carried out at 70 ° C. for 30 minutes. Unreacted gas was purged to obtain the target polypropylene. The isotactic pentad fraction of the obtained PP is 0.994.
Met. The MFR of the obtained PP was 32.8 g / 10 minutes. (PP-4) Polymerization was carried out in the following manner using one autoclave equipped with a stirrer and having an internal volume of 60 liters under a nitrogen atmosphere. 2.0 g of the prepolymerized catalyst component prepared by the above method, 11.4 g of triethylaluminum (100 m
mol), 5.9 g of t-butyltrimethoxysilane (3
3 mmol), and then 18 kg of propylene, the ethylene content of the polymer is 2.0% by weight, and the MFR is 2.5 g / 10.
Supply ethylene and hydrogen to 70 min.
Polymerization was carried out for 30 minutes. Unreacted gas was purged to obtain the target propylene-ethylene copolymer. The obtained random copolymer had an MFR of 2.2 g / 10 minutes and an ethylene content of 1.7% by weight.

Table 1 shows the properties of each polypropylene resin of the A1 component.

[Table 1]

[Preparation of γ-Ray Irradiated Polypropylene Resin (A2 Component)] (γPP-1) PP-1 (MFR = 0.5 g / 10)
Min, IP = 0.994: (Formula 2) in the text is satisfied)
Using a γ-ray irradiation device (automatic irradiation table) of Koga Isotope Co., Ltd.
0kGy (minimum dose 47.5kGy, maximum dose 52.6k
Gy, measured with a Perspex line meter). The MFR after irradiation was 5.6 g / 10 minutes. The presence of peroxide radicals was confirmed by ESR measurement. (ΓPP-2) PP-2 (MFR = 0.5 g / 10
Min, IP = 0.941: Do not satisfy (Equation 2) in the text, using a γ-ray irradiation device (automatic irradiation table) of Koga Isotope Co., Ltd. in a nitrogen atmosphere with an active oxygen concentration of 4.8%. At 50 kGy (minimum dose 47.5 kGy, maximum dose 5
2.6 kGy, measured with Perspex line meter).
The MFR after irradiation was 17.0 g / 10 minutes. The presence of peroxide radicals was confirmed by ESR.

[0037]

[Table 2]

[Temperature Dependence of β Crystal Fraction] 100% by weight of polypropylene resin composition containing 90% by weight of PP-1 as the component (A1) and 10% by weight of γPP-1 as the component (A2). Parts, 0.08 part by weight of di-t-butyl-p-cresol (BHT), pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-butylhydroxyphenyl) propionate] ( "Irganox 1010" manufactured by Nippon Ciba Geigy) is 0.05
By weight, 0.1 part by weight of calcium stearate (“calcium stearate”) was mixed and pelletized at 230 ° C. Using a high-pressure press (manufactured by Shoji Tekko Co., Ltd.), this was preheated at 230 ° C. for 5 minutes and degassed for 30 seconds, then left at 60 Kg / cm ² for 5 minutes, and then cooled at a specific cooling temperature (30 (10 to 100 ° C.) for 10 minutes to crystallize, and a 10 cm × 10 cm press sheet having a thickness of 0.5 mmt was produced. The temperature dependence of the β crystal fraction of the obtained press sheet is shown by “− ◯ −” in FIG. For comparison, the same evaluation was performed on pellets composed of the following two polypropylene resin compositions, and the results are shown in FIG. To 100 parts by weight of PP-11, 0.08 parts by weight of BHT, 0.05 parts by weight of Irganox 1010 and 0.1 parts by weight of calcium stearate were added and mixed, and a twin-screw extruder (“KTX-3
7 ”manufactured by Kobe Steel Ltd.) was melt-kneaded at 230 ° C. to prepare pellets, and the same evaluation was performed. It is shown by "-●-" in FIG. Furthermore, for 100 parts by weight of PP-11, 0.08 parts by weight of BHT, 1010 parts of Irganox
0.05 parts by weight, calcium stearate 0.1 parts by weight, a β crystal nucleating agent (“NCHESTER NU-100” manufactured by Shin Nippon Rika Co., Ltd.), and a twin-screw extruder (“KTX-3”).
7 ”) was melt-kneaded at 230 ° C. to prepare pellets, and the same evaluation was performed. It is shown by "-□-" in FIG. As is clear from FIG. 3, the polypropylene resin composition (-○-) of the present invention is different from the polypropylene resin composition of the comparative example in that it is characterized in that a large amount of β crystal is formed at low temperature. Have

[Preparation of Polypropylene Resin Material] Examples 1 to 11 and Comparative Examples 2, 3, 6, 7 to 15, 19 Polypropylene as component (A1) whose type and amount are shown in Tables 1 and 2. (A2) component (A2) gamma-irradiated polypropylene resin and BHT (0.05 parts by weight), Irganox 1010 (0.1% by weight) and calcium stearate (0.1 parts by weight). "SMV20 type" manufactured by Kawada Seisakusho Co., Ltd. was used for mixing, and a twin-screw extruder ("AS30 type" manufactured by Nakatani Machinery Co., Ltd.) was used, and the temperature was 230 ° C (200 using PP-3.
Pelletized. The screw speed of the extruder is 1
It was 00 rpm.

Examples 1 and 2 (examples utilizing crystal conversion from β crystal to α crystal by heat treatment), Comparative Examples 1 to 3 (Example 1) 97% by weight of PP-1 as component (A1), ( A2) Resin 1 containing 3% by weight of γPP-1
BHT in an amount of 0.05 parts by weight, Irganox 1010 in an amount of 0.1 parts by weight and calcium stearate in an amount of 0.1 parts by weight, were used to form a pelletized polypropylene resin composition by the above method. I got a thing. Using this pellet, a test piece for measuring the β crystal fraction was prepared (the β crystal fraction of the obtained press test piece was 43%.
Met). This test piece was heated for 2 hours in an oven whose temperature was controlled at 150 ° C. under a nitrogen atmosphere, and then cooled to room temperature to obtain a polypropylene resin material (β crystal content was 0%). After conditioning, the physical properties of this test piece were measured. The results are shown in Table 3.

(Example 2) PP-1 as component (A1)
Was used in the same manner as in Example 1 except that 90% by weight and 10% by weight of γPP-1 were used as the component (A2). The β crystal content of the pressed test piece before heat treatment was 47%. (Comparative Example 1) BHT 0.08 parts by weight, Irganox 10 which is a commercially available stabilizer, relative to 100 parts by weight of PP-1.
0.05 parts by weight of 10 and 0.1 parts by weight of calcium stearate were added, and the mixture was melt-kneaded at 230 ° C. using a twin-screw extruder (“KTX-37”) to form a pelletized polypropylene resin composition. Was produced. The pellet was used to prepare a test piece for measuring the β crystal fraction (the obtained press test piece had a β crystal fraction of 0%). The test piece was heated in an oven whose temperature was controlled at 150 ° C. for 2 hours under a nitrogen atmosphere, and then cooled to room temperature. After adjusting the condition of the test piece, the physical properties were measured. The results are shown in Table 3. (Comparative Example 2) PP-2 (MFR = 0.
6 g / 10 minutes, IP = 0.941) 90% by weight, Example 1 was repeated except that 10% by weight of γPP-2 was used as the component (A2). The β crystal fraction of the pressed test piece before heat treatment was 2%.

Comparative Example 3 The physical properties of the test piece of Example 2 before the heat treatment (β crystal content = 47%) were measured. The results are shown in Table 3.

[Table 3] Examples 3 to 9 (examples utilizing crystal conversion from β crystal to α crystal by α crystal nucleating agent), Comparative Examples 4 to 15 (Example 3) 99% by weight of PP-1 as component (A1), A polypropylene resin composition in the form of pellets was obtained by the above method using 1% by weight of γPP-1 as the component A2). Test pieces for measuring the β crystal fraction were prepared from the pellets. The obtained test piece (β crystal fraction 26%) was cut into 100 parts by weight of sodium-2,2′-methylene-bis (4,6-di-t) as a nucleating agent for α crystal.
-Butylphenyl) phosphate ("NA" manufactured by Asahi Denka Co., Ltd.
11 ") in an amount of 0.4 parts by weight, and a twin-screw extruder (KTX-
37) was used and melt-kneaded at 230 ° C. to obtain a polypropylene resin material. A test piece was prepared using the obtained polypropylene resin material (β crystal fraction 0%), and the physical properties were measured. The results are shown in Table 4.

(Example 4) PP-1 as component (A1)
Was used in the same manner as in Example 3 except that 98% by weight and 2% by weight of γPP-1 were used as the component (A2). The β-crystal fraction of the polypropylene resin composition is 39%, and sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA1
1 ″) was added in an amount of 0.4 part by weight, and the β-crystal content of the polypropylene resin material was 0%. The results are shown in Table 4. (Example 5) The procedure of Example 3 was repeated, except that 97 wt% of PP-1 was used as the component (A1) and 3 wt% of γPP-1 was used as the component (A2). The β-crystal fraction of the polypropylene resin composition is 42%, and sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA11”) which is a nucleating agent for α-crystal. To 0.4
Β of polypropylene resin material produced by adding parts by weight
The crystal fraction was 0%. The results are shown in Table 4.

(Example 6) PP-1 as component (A1)
Was used in the same manner as in Example 3 except that 95% by weight and 5% by weight of γPP-1 were used as the component (A2). The β-crystal fraction of the polypropylene resin composition is 43%, and sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA1
1 ″) was added in an amount of 0.4 part by weight, and the β-crystal content of the polypropylene resin material was 0%. The results are shown in Table 4. (Example 7) The procedure of Example 3 was repeated, except that 90% by weight of PP-1 was used as the component (A1) and 10% by weight of γPP-1 was used as the component (A2). The β-crystal fraction of the polypropylene resin composition is 47%, and sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate (“NA11”), which is a nucleating agent for α-crystal, is used. 0.
The β crystal fraction of the polypropylene resin material prepared by adding 4 parts by weight was 0%. Table 5 shows the results.

(Example 8) PP-1 as component (A1)
Was carried out in the same manner as in Example 3 except that 85% by weight of γPP-1 and 15% by weight of γPP-1 were used as the component (A2). The β-crystal fraction of the polypropylene resin composition was 47%, and sodium-2,2'-methylene-bis (4,6-
Di-t-butylphenyl) phosphate (“NA1
1 ″) was added in an amount of 0.4 part by weight, and the β-crystal content of the polypropylene resin material was 0%. Table 5 shows the results. (Example 9) Same as Example 3 (melt kneading at 200 ° C) except that 90% by weight of PP-3 was used as the component (A1) and 10% by weight of γPP-1 was used as the component (A2). went. The β crystal fraction of the polypropylene resin composition is 1
7%, 0.4% by weight of sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate ("NA11"), which is a nucleating agent for α crystal, was added. The β crystal content of the polypropylene resin material was 0%. Table 5 shows the results.

[0046]

[Table 4]

[0047]

[Table 5]

Comparative Example 4 To 100 parts by weight of PP-1, 0.08 part by weight of a commercially available stabilizer, 0.05 parts by weight of Irganox 1010 and 0.1 parts by weight of calcium stearate were added. Twin screw extruder (KTX-3
7) was used and melt-kneaded at 230 ° C. to prepare pelletized polypropylene. This pellet (β crystal fraction 0
%) 100 parts by weight of sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate as a nucleating agent for α crystals ("NA11" manufactured by Asahi Denka Co., Ltd.)
0.4 part by weight of was added and melt-kneaded at 230 ° C. using a twin-screw extruder (KTX-37) to produce a polypropylene resin material. Using this, a test piece was prepared and its physical properties were measured. The results are shown in Table 6. (Comparative Example 5) The procedure of Comparative Example 4 was repeated except that PP-3 was used instead of PP-1, except that melt kneading was performed at 200 ° C. The β crystal fraction of the pellets corresponding to the polypropylene resin composition was 0%. A test piece was prepared using a polypropylene resin material and its physical properties were measured. The results are shown in Table 6.

(Comparative Example 6) PP-1 as component (A1)
By 99% by weight and 1% by weight of γPP-1 as the component (A2) by the above method.
7) was melt-kneaded at 230 ° C., and in the molten state, sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate was used as a nucleating agent for α crystal. (Asahi Denka Co., Ltd. "NA11") 0.4 part by weight was added to prepare a polypropylene resin material in pellet form. Using this, a test piece was prepared and its physical properties were measured. The results are shown in Table 6. (Comparative Example 7) The procedure of Comparative Example 6 was repeated except that 98% by weight of PP-1 was used as the component (A1) and 2% by weight of γPP-1 was used as the component (A2). Table 6 shows the results. (Comparative Example 8) Comparative example 8 was carried out in the same manner as in Comparative example 6 except that 97% by weight of PP-1 was used as the component (A1) and 3% by weight of γPP-1 was used as the component (A2). Table 7 shows the results.

(Comparative Example 9) PP-1 as component (A1)
Was used in the same manner as in Comparative Example 6 except that 95% by weight of γPP-1 and 5% by weight of γPP-1 were used as the component (A2). The results are shown in Table 7.
Shown in (Comparative Example 10) The procedure of Comparative Example 6 was repeated except that 90% by weight of PP-1 was used as the component (A1) and 10% by weight of γPP-1 was used as the component (A2). Table 7 shows the results. (Comparative Example 11) Comparative example 6 was carried out in the same manner as in Comparative example 6 except that 85% by weight of PP-1 was used as the component (A1) and 15% by weight of γPP-1 was used as the component (A2). Table 7 shows the results. (Comparative Example 12) The same as Comparative Example 6 (melt kneading at 200 ° C.) except that 90% by weight of PP-3 was used as the component (A1) and 10% by weight of γPP-1 was used as the component (A2). went. Table 8 shows the results. (Comparative Example 13) A polypropylene resin composition in the form of pellets was obtained by the above method using 90% by weight of PP-2 as the component (A1) and 10% by weight of γPP-2 as the component (A2). From the pellets, the above-mentioned test piece for measuring the β crystal fraction was produced. Obtained test piece (β crystal content 2%)
With respect to 100 parts by weight of the cut product, sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate as a nucleating agent for α crystal ("NA11" manufactured by Asahi Denka Co., Ltd.) 0.4 part by weight is added to the twin screw extruder (K
TX-37) was melt-kneaded at 230 ° C. to obtain a polypropylene resin material. A test piece was prepared using the obtained polypropylene resin material, and the physical properties were measured.
The results are shown in Table 8.

Comparative Example 14 PP-as the (A1) component
A polypropylene resin composition in the form of pellets was obtained by the above method using 97% by weight of 1 and 3% by weight of γPP-1 as the component (A2). From the pellets, a 10 cm × 10 cm press sheet having a thickness of 0.5 mmt was prepared at a pressing temperature of 135 ° C. based on the method described in the above section “[Temperature Dependence of β Crystal Fraction]”. Sodium-2,2'-methylene-bis (4,6-di-t-) as an α crystal nucleating agent was added to 100 parts by weight of the primary molded product obtained by cutting the obtained press sheet (β crystal content 0%). Butylphenyl) phosphate (“NA11” manufactured by Asahi Denka Co., Ltd.) was added in an amount of 0.4 part by weight and melt-kneaded at 230 ° C. using a twin-screw extruder (KTX-37) to obtain a polypropylene resin material. It was A test piece was prepared using the obtained resin material and its physical properties were measured. The results are shown in Table 8. (Comparative Example 15) Comparative example 14 was repeated except that 90% by weight of PP-1 was used as the component (A1) and 10% by weight of γPP-1 was used as the component (A2). The β crystal fraction of the obtained polypropylene resin composition sheet (primary molded product) was 0%. The results are shown in Table 8.

(Comparative Example 16) With respect to 100 parts by weight of PP-3, 0.08 part by weight of a commercially available stabilizer, 0.05 part by weight of Irganox 1010, 0.1 part by weight of calcium stearate, β 0.2 parts by weight of "Ngester NU-100" manufactured by Shin Nippon Rika Co., Ltd. was added as a crystal nucleating agent, and the mixture was melt-kneaded at 200 ° C using a twin-screw extruder (KTX-37) to prepare pellets. did. From the pellets, the press sheet for measuring the β crystal fraction (however, 10
Crystallization at 0 ° C.) was made. Obtained press sheet (β
100 parts by weight of the cut crystal fraction of 47%),
0.4 part by weight of sodium-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate ("NA11" manufactured by Asahi Denka Co., Ltd.) was added as an α crystal nucleating agent, and 2
Using a shaft extruder (KTX-37), the mixture was melt-kneaded at 200 ° C. to obtain a pellet-shaped polypropylene resin material. The β crystal fraction of this resin material was 6%. A test piece was prepared using this resin material, and the physical properties were measured. The results are shown in Table 9.

[0053]

[Table 6] *: PP-based resin material produced without passing through β-crystal-containing pellets.

[0054]

[Table 7] *: PP-based resin material produced without passing through β-crystal-containing pellets.

[0055]

[Table 8] *: PP-based resin material produced without passing through β-crystal-containing pellets. **: Primary compact before adding α crystal nucleating agent (130 ° C crystallization)
The β crystal fraction of is 0%.

[0056]

[Table 9] The rigidity and heat resistance also greatly depend on the MFR of the resin. Examples 1-8 and Comparative Examples 1-4, 6-11, 13-
When 15 is a low MFR, Example 9 and Comparative Examples 5 and 12,
16 corresponds to the case of high MFR. From Tables 3 to 9, in the MFR of the same degree, the polypropylene-based resin material of the example is more rigid than the polypropylene-based resin material of the comparative example.
It can be seen that it has excellent heat resistance.

Examples 10 and 11 (example utilizing crystal conversion from β crystal to α crystal by α crystal nucleating agent), Comparative Example 19 (Example 10) 95% by weight of PP-1 as component (A1), Using 5% by weight of γPP-1 as the component (A2),
1,3,2,4-bis (p-methylbenzylidene) sorbitol as a crystal nucleating agent ("Gelol M" manufactured by Shin Nippon Rika Co., Ltd.
D-R ") was used in the same manner as in Example 3 except that 0.3% by weight was used. The results are shown in Table 10. (Example 11) 95% by weight of PP-4 was used as the component (A1), 5% by weight of γPP-1 was used as the component (A2), and 0.25% of "gelol MD-R" was used as the α crystal nucleating agent.
The same procedure as in Example 3 was carried out except that the weight% was used. The results are shown in Table 10. (Comparative Example 19) 95% by weight of PP-1 and 5% by weight of γPP-1 were used, and "gelol MD-R" was used as an α crystal nucleating agent.
Was performed in the same manner as in Comparative Example 9 except that 0.3% by weight was used.
The results are shown in Table 10.

[0058]

[Table 10] *: PP-based resin material produced without passing through β-crystal-containing pellets.

(Comparative Example 17) The procedure of Comparative Example 4 was repeated except that 100 parts by weight of PP-1 was used and no nucleating agent was used.
The results are shown in Table 11. (Comparative Example 18) The same method as in Comparative Example 4 was carried out except that 100 parts by weight of PP-1 was used and 0.3% by weight of "gelol MD-R" was used as the α crystal nucleating agent. Table 1 shows the results
1 is shown. Comparative Example 20 The procedure of Comparative Example 4 was repeated except that 100 parts by weight of PP-4 was used and no nucleating agent was used. Table 11 shows the results.
It was shown to. (Comparative Example 21) The procedure of Comparative Example 4 was repeated except that 100 parts by weight of PP-4 was used and 0.25% by weight of "gelol MD-R" was used as the α crystal nucleating agent. The results are shown in Table 11.

[0060]

[Table 11]

[0061]

The polypropylene resin material of the present invention is
The rigidity, heat resistance, and transparency are extremely superior to conventional ones. Therefore, it is particularly suitable as a substitute for engineering plastics as a raw material for structural materials used in injection molding, blow molding, sheet molding, vacuum molding and the like.

[Brief description of drawings]

FIG. 1 is a graph showing a calorific value curve during crystallization by a differential scanning calorimetry method.

FIG. 2 is a graph showing an endothermic curve at the time of melting by a differential scanning calorimetry method.

FIG. 3 is a graph showing the press temperature dependence of the β crystal fraction.

FIG. 4 is an ESR spectrum of polypropylene.

Front page continued (72) Inventor Murayama Koshin 2 Oita City, Oita Prefecture, 2 Oita, Nakajima, Japan Polyolefin Co., Ltd. Oita Plant (72) Inventor Hideharu Goto 2 Oita, Oita Prefecture, Naka, 2 Showa Denko Shares Company Oita Plant (72) Inventor Tasuke Kinoshita Oita City, Oita Prefecture 2nd Nakanoshima, Japan Polyolefin Co., Ltd. Oita Research Center

Claims (11)

[Claims] 1. A β crystal content of 5% or more when measured using a press-molded product which is crystallized isothermally at 30 ° C., and a β crystal content ratio when crystallized isothermally at 30 ° C. and 100 ° C., respectively. Is β (30) and β (100),
(Equation 1) is satisfied, (Equation 1) β (30)> β (100), and at least a part of β crystal of the polypropylene resin composition having a melt flow rate of 0.05 to 1000 g / 10 minutes is α crystal. A method for producing a polypropylene-based resin material, comprising: 2. A melt flow rate of 0.05 to 100.
70 to 99.5% by weight of polypropylene resin, which is 0 g / 10 minutes, and 0.5 to 30% by weight of polypropylene resin having the following physical properties (a) and (b), which is treated to generate peroxide radicals. % Is 5 and the β crystal fraction obtained by melt-kneading is a state in which peroxide radicals are not deactivated before melting.
% Or more of at least a part of β crystal of the polypropylene resin composition is converted to α crystal. (A) Melt flow rate is 5 g / 10 minutes or less (b) Isotactic pentad fraction (abbreviated as IP)
And the melt flow rate (abbreviated as MFR) have a relationship of (Equation 2) (Equation 2) IP> 0.0428 × log (MFR) +0.97 3. At least a part of β crystal is converted to α crystal,
The method for producing a polypropylene-based resin material according to claim 1 or 2, wherein the β crystal fraction is 2% or less. 4. The method for producing a polypropylene resin material according to claim 1, wherein the conversion is performed by adding an α-crystal nucleating agent. 5. The polypropylene resin composition has a propylene chain isotactic pentad fraction of 0.9.
It is 70 or more, The manufacturing method of the polypropylene resin material of Claim 1 or 2 characterized by the above-mentioned. 6. The polypropylene-based resin composition according to claim 10.
The method for producing a polypropylene resin material according to claim 4, wherein the amount of the α-crystal nucleating agent added is 0.01 to 30 parts by weight with respect to 0 parts by weight. 7. The method for producing a polypropylene resin material according to claim 4, wherein the α-crystal nucleating agent is an alkali metal salt. 8. The method for producing a polypropylene resin material according to claim 7, wherein the alkali metal salt is a phosphate alkali metal salt. 9. The alkali metal salt is sodium-2, 2 '.
-Methylene-bis (4,6-di-t-butylphenyl)
9. The method for producing a polypropylene-based resin material according to claim 8, which is a phosphate. 10. A polypropylene-based resin material obtained by the method according to any one of claims 1 to 9. 11. The polypropylene resin material according to claim 10, having a melt flow rate of 0.05 to 1000 g / 10 minutes, a melt flow rate (MFR), and an endothermic amount at the time of melting measured by a differential scanning calorimetry method. ΔHm and calorific value during crystallization Δ
A polypropylene-based resin material having a ratio of Hc that satisfies (Equation 3). (Equation 3) ΔHm / ΔHc> 0.00007915log (MFR) +1.032