JP2002226645A - Polypropylene-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene-based resin composition which is excellent in rigidity and heat stability, has a low specific gravity, exhibits a small warpage of a molded article and is suited for structure material for automobile parts or household electric appliance parts. SOLUTION: Specific amounts of fine powder talc, magnesium 1,2- dihydroxystearate, a neutralizer of an inorganic type and magnesium salt of diterpene acid are blended with crystalline polypropylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene resin composition, and more particularly, it has excellent characteristics such as high rigidity, high heat resistance, low specific gravity, and low warpage, and is used for automobile parts and home electric parts. The present invention relates to a polypropylene-based resin composition for injection molding, which is useful as a material for the resin composition.

[0002]

2. Description of the Related Art Polypropylene is used in a wide variety of fields such as daily necessities and industrial parts because of its excellent properties such as excellent chemical resistance and low specific gravity. However, since high rigidity and heat resistance are required as materials for industrial parts such as automobile parts and home electric parts, a nucleating agent such as a metal salt of benzoic acid or a metal salt of organic phosphoric acid is blended with polypropylene and crystallized. Modification by a method of increasing the degree of conversion has been performed.
However, in many applications, materials obtained by this method may have insufficient rigidity and heat resistance. In order to meet these demands for high physical properties, compositions containing inorganic fillers such as talc and mica are widely used. However, in this method, in order to obtain the required high rigidity and heat resistance, it is generally necessary to mix an inorganic filler in an amount of about 10 to 40%, so that there is a disadvantage that the specific gravity of the material is increased. In addition, when the inorganic filler is filled in an amount of about 10 to 40%, there are adverse effects such as a decrease in impact resistance of the material and a decrease in gloss of a molded product.

On the other hand, since structures such as automobile parts and home electric parts often need to be assembled with other parts, it is necessary to suppress warpage deformation as small as possible when using resin molded products for these structures. As a method for suppressing the warpage of a polypropylene resin molded article, a method of blending 20% or more of an inorganic filler such as calcium carbonate is generally used. However, a drawback such as an increase in specific gravity and a decrease in impact strength is caused. There is.

[0004] In general, in an industrial polypropylene production process, a polypropylene resin produced in a polymerization tank is sent to an extruder through an empty feed line or the like through a drying process and the like, where it is melt-kneaded with additives and pelletized. Become. However, when attempting to mix a large amount of inorganic filler in this step, the inorganic filler remains in the system of the manufacturing process such as a hopper, a pipe, and an extruder cylinder,
Since there is a high risk of affecting contamination or the like on production grades not containing other inorganic fillers, it is extremely difficult industrially and is not usually performed.

[0005] Therefore, in order to produce a polypropylene resin composition containing an inorganic filler, a method is used in which the polypropylene pellets obtained in the above-mentioned production process are further charged into a special extruder and melt-kneaded with the inorganic filler. However, in this case, there is a disadvantage that the production cost of the material is increased due to complicated processes.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the above-mentioned drawbacks of the prior art, to provide excellent rigidity and heat resistance, a low specific gravity, and a small warpage of a molded article in an automobile part or home appliance. An object of the present invention is to provide a polypropylene-based resin composition which is suitable for a structural material of a part and does not require a dedicated extruder at the time of production and can suppress production cost.

[0007]

Means for Solving the Problems In view of the above-mentioned problems, the present inventors have continued intensive studies and have found that talc, magnesium 1,2-hydroxystearate,
The inventors have found that the above-mentioned problems can be solved by blending a specific amount of an inorganic neutralizing agent and a magnesium salt of diterpenic acids, and have led to the present invention.

That is, according to the present invention, (A) the MFR is from 6 to 50.
g / 10 min, the boiling heptane-insoluble content is 85% by weight or more, the main elution peak in the temperature-rise elution fractionation is 116 ° C. or more, and the half width temperature of the main elution peak is 3.
100 parts by weight of a highly crystalline polypropylene resin having a temperature of less than 7 ° C., (B) magnesium salt of diterpenic acid 0.1 to 0.1
2 parts by weight, (C) 0.5 to 6 parts by weight of talc, (D) 1,
Magnesium 2-hydroxystearate 0.03-1
It is a polypropylene resin composition comprising parts by weight and (E) 0.01 to 5 parts by weight of an inorganic neutralizing agent.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The melt flow rate (hereinafter abbreviated as MFR) of the highly crystalline polypropylene resin in the present invention is 6 to 5
0 g / 10 min, preferably 10 to 40 g / 10 min. Here, the MFR is a value at a cylinder temperature of 230 ° C. according to JIS K7210. M
If the FR is less than 6, the warpage of the molded article increases,
If it exceeds 50, the impact strength is significantly impaired.

The highly crystalline polypropylene resin of the present invention has a boiling heptane-insoluble portion of 85% by weight or more, preferably 90% by weight or more. If the boiling heptane insoluble content is less than 85% by weight, rigidity and heat resistance are insufficient.
Here, the boiling heptane-insoluble portion of the highly crystalline polypropylene resin is obtained by completely dissolving the resin in boiling xylene.
This is an extraction residue obtained by lowering the temperature to 0 ° C., allowing the mixture to stand, separating and filtering, drying the insoluble portion, and performing boiling heptane extraction with a Soxhlet extraction tube for 12 hours.

Further, the highly crystalline polypropylene resin of the present invention has a main elution peak temperature of 116 ° C. or higher in a temperature-rise elution fractionation (hereinafter abbreviated as TREF) using ortho-dichlorobenzene, and The half width temperature is less than 3.7 ° C. The higher the elution peak temperature in TREF and the smaller the half width temperature, the remarkably higher crystallization rate and higher crystallinity due to the interaction with a nucleating agent comprising a magnesium salt of diterpenic acid used in the present invention described later. To increase the rigidity,
In addition, it is possible to obtain a molded product with less warpage.

TREF is a technique for measuring the crystallinity distribution of a polyolefin. An ortho-dichlorobenzene solution of a polymer is introduced and held in a column, and the temperature is lowered to crystallize the filler in the column. The temperature of the column is raised while flowing chlorobenzene, and the concentration of the polymer eluted at each temperature is measured by detecting with an infrared detector. The temperature of the maximum peak appearing in the elution curve obtained by TREF is defined as the main elution temperature, and the half-width temperature of the main elution peak is the width of the peak at half the height of this peak.

The above-mentioned highly crystalline polypropylene resin is a propylene homopolymer, a propylene-ethylene block copolymer, a propylene-ethylene random copolymer, a copolymer with an α-olefin other than propylene, or a polypropylene-based copolymer of these. Polymers obtained by mixing two or more kinds of polymers at an arbitrary ratio, or those obtained by mixing different types of polymers or elastomers such as ethylene-α-olefin copolymers with a polypropylene-based polymer can also satisfy the above-mentioned requirements for the characteristic values. For example, it can be used as a highly crystalline polypropylene resin in the present invention.

Further, in consideration of heat resistance, the isotactic pentad fraction of the boiling heptane-insoluble component is preferably 0.98 or more, more preferably 0.985 or more. The isotactic pentad fraction of the boiling heptane-insoluble portion refers to the above-mentioned boiling heptane-insoluble portion of polypropylene as A.I. A method published by Zambelli et al. (Macromolecules 6 925).
1973) is a value obtained by measuring the fraction of propylene monomer units at the center of a chain in which five propylene monomer units are consecutively meso-bonded in pentad units in a polypropylene molecule.

In the present invention, a method for producing a highly crystalline polypropylene resin having such characteristics is disclosed in
JP-A-1583 can be used, but a known method for producing a polypropylene-based resin can be used without limitation.

The catalyst is generally a Ziegler-Natta type stereospecific catalyst, and a catalyst comprising a titanium compound supported on magnesium chloride or a titanium trichloride compound and an organoaluminum compound is used.

As the titanium compound, known compounds used for olefin polymerization can be used without any limitation.
In particular, a titanium compound containing titanium, magnesium and halogen as components and having a high catalytic activity and capable of obtaining a highly crystalline polymer is preferable. Examples of such a titanium compound include titanium halides, particularly titanium tetrachloride supported on various magnesium compounds. As a method for producing this catalyst, a known method is employed without any limitation. For example, a method of co-grinding titanium tetrachloride with a magnesium compound such as magnesium chloride, alcohol, ether,
Examples thereof include a method of co-grinding a titanium halide and a magnesium compound in the presence of an electron donor such as an ester, a ketone or an aldehyde, and a method of contacting a titanium halide, a magnesium compound and an electron donor in a solvent.

Next, as the organoaluminum compound,
Known compounds used for olefin polymerization can be used without any limitation. For example, alkyl aluminums such as trimethyl aluminum, triethyl aluminum and tri-n-propyl aluminum; and halogen-containing alkyl aluminums such as ethyl aluminum sesquichloride and diethyl aluminum chloride can be used.

Further, in order to enhance the crystallinity of the obtained polymer, it is preferable to use an electron donor in addition to the above titanium compound and organic aluminum compound. Examples of the electron donor include ether, amine, amide, sulfur-containing compound, nitrile, carboxylic acid, acid amide, acid anhydride, acid ester, and organosilicon compound. Of these, organosilicon compounds are most preferred.

The polymerization may be carried out in a gas phase or in a liquid phase. The polymerization may be carried out in an inert liquid or an inert solvent with respect to the catalyst.The polymerization may be carried out by introducing hydrogen during polymerization, or the obtained polymer may be prepared by a molecular weight regulator such as an organic peroxide. Degraded ones may be used. Further, the polymerization can be carried out by any of batch, semi-batch and continuous methods.

The polymerization conditions are not particularly limited as long as the effects of the present invention are recognized, and known conditions can be employed. For example, the polymerization temperature is 20-200 ° C., preferably 5
The range is 0 to 150 ° C. Further, the polymerization can be carried out in two or more stages under different conditions.

The polypropylene resin composition of the present invention contains a magnesium salt of diterpenic acid as a nucleating agent in an amount of 0.1 to 100 parts by weight of the highly crystalline polypropylene resin.
To 2 parts by weight, preferably 0.2 to 1 part by weight.
When the amount is less than 0.1 part by weight, a sufficient effect as a nucleating agent cannot be obtained, and when the amount exceeds 2 parts by weight, the rigidity of the composition decreases, which is not preferable.

The magnesium salt of a diterpene acid is a reaction product of a diterpene acid and a magnesium compound. Diterpenic acid is a rosin generally known as a natural resin obtained from pinaceous plants, specifically, a natural rosin such as gum rosin, tall oil rosin, wood rosin; disproportionated rosin, hydrogenated rosin, dehydrogenated Various modified rosins such as rosin, polymerized rosin, α, β-ethylenically unsaturated carboxylic acid modified rosin, and purified products of the above-mentioned natural rosin and modified rosin can be obtained as raw materials. Examples of the diterpenic acids include pimaric acid, sandaracopimaric acid, parastolic acid, isopimaric acid, abietic acid, dehydroabietic acid, neoabietic acid, dihydropimaric acid, dihydroabietic acid, tetrahydroabietic acid, and the like.

In the present invention, a magnesium salt of such a diterpene acid or a derivative thereof is used. In addition, these magnesium salts of diterpenic acids may be used as a mixture with diterpenic acids. In that case, the magnesium salt of diterpenic acids is
The content is preferably 20% by weight or more in the mixture.

The metal salts of diterpenic acids preferably used in the present invention are represented by the general formula (I)

[0026]

Embedded image

Or the general formula (II)

[0028]

Embedded image

(Wherein, R1, R2 and R3 are each a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group).

Specific examples of the alkyl group include methyl, ethyl, n-propyl, 1-propyl, n-butyl and 1-butyl.
Examples thereof include an alkyl group having 1 to 8 carbon atoms such as butyl, tert-butyl, pentyl, and octyl, and these groups may have a substituent such as a hydroxyl group, a carboxy group, an alkoxyl group, and a halogen.

Specific examples of the cycloalkyl group include cycloalkyl groups having 5 to 8 carbon atoms such as cyclopentyl, cyclohexyl, and cyclopeptyl. These groups include a hydroxyl group, a carboxyl group, an alkoxy group,
It may have a substituent such as halogen.

The aryl group includes an aryl group having 6 to 10 carbon atoms such as a phenyl group, a tolyl group and a naphthyl group, and these groups have a substituent such as a hydroxyl group, a carboxyl group, an alkoxy group and a halogen. May be.

The groups represented by R1, R2 and R3 may be the same or different. Among the compounds represented by the formulas (I) and (II), a compound in which R1, R2, and R3 are the same or different alkyl groups is preferable, R1 is a 1-propyl group, and R2 and R3 are Compounds that are methyl groups are more preferred.

Specific examples of the compound represented by the above formula (I) include magnesium dehydroabietic acid. Specific examples of the compound represented by the above formula (II) include dihydroabietic acid. Magnesium.

These magnesium salts of diterpenic acids can be produced by subjecting rosin to disproportionation or dehydrogenation as required, followed by purification, and then distilling the resulting diterpene acid into magnesium by a conventional method. . Of course, not only those diterpene acids extracted from the rosin but also those that can be synthesized may be used as synthesized products.

The propylene resin composition of the present invention contains 0.5 to 6 parts by weight of talc. If the amount of talc is less than 0.5 part by weight, the rigidity is insufficient, the surface impact strength is lowered, and the warpage of the molded product is increased. When the amount of talc exceeds 6 parts by weight, the rigidity is increased, but the surface impact strength is reduced, the glossiness of the molded product surface is reduced, and the specific gravity is increased, and the object of the present invention is impaired. Further, by setting the blending amount of talc to 3 to 20 times the blending amount of the nucleating agent consisting of the metal salt of diterpenic acids, the crystallinity is enhanced by the synergistic effect with the nucleating agent consisting of the metal salt of diterpenic acid. Improves rigidity and impact resistance. Further, by controlling the state of crystal orientation, the anisotropy of the molding shrinkage is reduced, and the warpage of the molded product can be significantly reduced.

As the talc used in the present invention, it is preferable to use talc having an average particle diameter of 2 to 8 μm as measured by laser diffraction, since the effect of improving the surface impact strength is enhanced. Further, in consideration of the effect of improving rigidity, the aspect ratio measured by an electron microscope is preferably 5 or more.

The polypropylene resin composition of the present invention contains 0.03 to 1 part by weight of magnesium 1,2-hydroxystearate. When the amount is less than 0.03 parts by weight, the rigidity is insufficient, and when the amount exceeds 1 part by weight, the surface of the molded article is easily contaminated by bleed.

The polypropylene-based resin composition of the present invention contains 0.01 to 5 parts by weight of an inorganic neutralizer per 100 parts by weight of the highly crystalline polypropylene-based resin. When the amount of the inorganic neutralizing agent is less than 0.01 part by weight, the effect of improving the rigidity is low, and when the amount exceeds 5 parts by weight, the effect of the neutralizing agent is saturated, which is not only economically unfavorable but also increases the specific gravity. Absent.

As the inorganic neutralizing agent, known ones such as synthetic hydrotalcite and a composite hydroxide salt of lithium and aluminum can be used without limitation, and a composite hydroxide salt of lithium and aluminum is most preferable. . The composite hydroxide salt of lithium and aluminum is generally represented by the general formula (III) [LiAl ₂ (OH) ₆ ] ₂ X · mH ₂ O (III) (where X is CO ₃ , SO ₄ or a HPO _4, m is a compound represented by a number from 0 to 3.). Such a composite hydroxide salt of lithium and aluminum effectively acts on the nucleating agent comprising the metal salt of diterpenic acid, and increases the rigidity of the polypropylene resin composition.

In the present invention, a composite hydroxide salt of lithium and aluminum which is preferably used is, for example, [LiAl ₂ (OH) ₆ ] ₂ CO ₃ .1.6H ₂ O [LiAl ₂ (OH) ₆ ] ₂ SO ₄ .1.2H ₂ O [LiAl ₂ (OH) ₆ ] ₂ HPO ₄ .1.4H ₂ O.

Further, various additives can be appropriately added to the highly crystalline polypropylene resin constituting the composition of the present invention so far as the effects of the present invention are not impaired. Specifically, phenol-based, organic phosphite-based, phosphite-based organic phosphorus-based, thioether-based antioxidants; hindered amine-based heat stabilizers; benzophenone-based, benzotriazole-based, benzoate-based ultraviolet absorbers, etc. Nonionic, cationic, anionic and other antistatic agents; bisamides, waxes, amides, waxes, organometallic salts, esters and other lubricants;
Oxide-based decomposers; metal deactivators such as hydrazines and amines; flame retardants such as brominated organic, phosphoric, antimony trioxide, magnesium hydroxide, and red phosphorus; organic pigments; inorganic pigments; Organic fillers; inorganic and organic antibacterial agents such as metal ions;

In consideration of the basic processing stability and heat aging resistance of the polypropylene resin composition, a phenolic antioxidant is added to 100 parts by weight of the highly crystalline polypropylene resin. 0.01 to 1 part by weight, and / or hindered amine stabilizer 0.0
1 to 1 part by weight, and a phosphorus-based antioxidant 0.01 to 1
It is preferable to add parts by weight. In addition, when high heat resistance is required, a sulfur-based antioxidant, when high weather resistance is required, an ultraviolet absorber, when deterioration prevention due to metal contact is required. Can use a copper damage inhibitor.

As the phenolic antioxidant, 3,
5-di-t-butyl-4-hydroxytoluene, tetrakis [methylene-3,5-di-t-butyl-4-hydroxyphenyl] propionate] methane, tris (3
5-di-t-butyl-4-hydroxybenzyl) isocyanurate, n-octadecyl-3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate,
Tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4, 6-trimethylbenzene, 3,9-bis {2- [3 (3-t-butyl-4-hydroxy-5-
Methylphenyl) propionyloxy] -1,1-dimethylethyl {2,4,8,10-tetraoxaspiro [5,5] undecane.

Hindered amine stabilizers include bis (2,2,6,6-tetramethyl-4piperidyl) sebacate and bis-succinate- (2,2,6,6-tetramethyl-4-piperidyl) Ester, bis (1,2,
2,6,6, -pentamethyl-4-piperidyl) sebacate, 8-benzyl-7,7,9,9-tetramethyl-
3-octyl-1,3,8-triazaspiro [4,5]
Undecane-2,4-dione, 1- [2- [3- (3,
5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine, 2
Bis (1,2,2,6,-(3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid
6-pentamethyl-4-piperidyl), poly [@ 6-
(1,1,3,3-tetramethylbutyl) amino-1,
3,5-triazine-2,4-diyl {2,2,6
6-tetramethyl-4-piperidyl) imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}], dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy- 2,2,6,6-tetramethylpiperidine polycondensate, N, N'-bis (3-
Aminopropyl) ethylenediamine 2,4-bis [N
-Butyl-N- (1,2,2,6,6-pentamethyl-
4-piperidyl) amino] -6-chloro-1,3,5-
And triazine condensates.

As a phosphorus-based antioxidant, tris (2,
4-di-t-butylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol-di-phosphite, tris (mono, di-norylphenyl) phosphite, tetrakis (2,4 -Ji-
(t-butylphenyl) -4,4′-biphenylenephosphonite, bis (2,4-di-t-methylphenyl) pentaerythritol-diphosphite and the like.

Examples of the sulfur-based antioxidants include dimyristyl thiodipropionate, trilauryl trithiophosphite, dioctadecyl disulfide, pentaerythrityl tetrakis (β-lauryl thiopropionate), distearyl disulfide, And stearyl thiodipropionate.

As the ultraviolet absorbing material, 2- (3-t-butyl-2-hydroxy-5-methylphenyl) -5-chlorobenzotriazole, 2'4'-di-t-butylphenyl-3,5-di- t-butyl-4 hydroxybenzoate and the like.

Examples of the copper damage inhibitor include 3- (N-salicyloyl) amino 1,2,4-triazole and N, N'-bis [3 (3,5-t-butyl-4-hydroxyphenyl) propionyl]. Hydrazine, 2,2′-oxamide-bis [ethyl-3- (3,5-di-tert-butyl-4-
Hydroxyphenyl) propionate].

In the present invention, the above-mentioned components can be blended by any ordinary method used for mixing resins without any limitation. For example, a method in which an additive component is added to a powdery or pellet-like highly crystalline polypropylene-based resin, mixed with a tumbler, a Henschel mixer, or the like, and then melt-kneaded with an extruder to form pellets or the like is preferable. The order of addition of each component is not particularly specified,
Each component may be mixed in a different order from the above method. Furthermore, a masterbatch in which each component is concentrated and blended at a high concentration can be prepared and mixed and used.

The polypropylene resin composition of the present invention comprises:
It is formed into automobile parts, home electric parts and the like by a known molding method such as injection molding, press molding, extrusion molding, stampable molding and the like. Usually, it is generally formed by injection molding. This injection molding may be performed by any method such as single-axis injection molding, multi-axis injection molding, injection compression molding, gas assist injection, gas compression injection molding, melt core molding, insert molding, core back molding, and two-color molding. .

[0052]

According to the present invention, a magnesium salt of diterpenic acid, talc,
By blending magnesium 1,2-hydroxystearate and an inorganic neutralizing agent in specific amounts, it is excellent in rigidity and heat resistance, and has low specific gravity and low warpage of molded products. A suitable polypropylene-based resin composition can be obtained.

Since the polypropylene-based resin composition of the present invention contains only a small amount of talc, the talc is further added to a special extruder to mix the talc with the polypropylene pellets obtained in the production process. Therefore, there is no need to melt-knead with talc, and it can be melt-kneaded together with other additives into pellets in a general industrial polypropylene production process, thereby suppressing production cost.

[0054]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to the following Examples.
Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

The symbols and characteristic values of the polypropylene resins used in the examples are as shown in Table 1. The structural analysis of the polypropylene-based resin shown in Table 1 was performed as follows.

MFR 230 ° C., load 2.1 according to JIS K7210
The measurement was performed at 6 kg.

Ethylene content Calculated using a chart of ¹³ C-NMR spectrum.
That is, first, the ratio of the monomer unit based on ethylene is firstly described in Polymer Vol. 29, 1848 (1988).
Year), determine peak attribution,
Next, Macromolecules Volume 10, 773
Calculated by the method described in section (1977).

5 g of a boiling heptane-insoluble matter content After completely dissolving 5 g of a polypropylene resin in 500 ml of boiling xylene, the temperature was lowered to 20 ° C. and allowed to stand still for about 20 hours, followed by separation and filtration, and drying of the insoluble portion. Further, the dry weight of the extraction residue obtained by performing boiling heptane extraction with a Soxhlet extraction tube for 12 hours was measured, and the insoluble content was determined by the following equation.

Boiling heptane insoluble content (%) = weight of extraction residue / sample weight before extraction × 100 · isotactic pentad content of boiling heptane insoluble
The boiling heptane-insoluble part obtained by the above operation was treated with ¹³ C-NM
R was measured using the obtained NMR chart. Za
mbelli et al. (Macrom
olecules 6 925 1973)
The fraction of the propylene monomer unit at the center of the chain in which five propylene monomer units were consecutively meso-bonded in the pentad unit in the polypropylene molecule was calculated, and the fraction was determined as the isotactic pentad fraction of the boiling heptane-insoluble portion.

Temperature rise elution fractionation (TREF) MPC-1000 manufactured by Uniflows Co., Ltd. was used. 25 mg of a sample was added to 5 ml of orthodichlorobenzene (hereinafter abbreviated as ODCB) at 140 ° C. under a nitrogen atmosphere.
After dissolving for 0 minute, 0.5 ml of this sample solution was pumped into a TREF column (inner diameter 4.6 mm, length 150 mm) packed with chromosolve as an inert carrier.
After stopping the liquid feeding, the temperature was lowered from 140 ° C. to 0 ° C. at 5 ° C./h to crystallize the polymer on the carrier. Thereafter, the temperature was raised at 40 ° C./h while continuously flowing ODCB at 1 ml / min, and the polymer concentration eluted at each temperature was measured by detecting with an infrared detector. The temperature of the maximum peak appearing in the elution curve obtained by TREF was defined as the main elution temperature, and the width of the peak at half the height of the peak was defined as the half width temperature of the main elution peak.

The additives used in the examples and their symbols are as follows. A1: Magnesium 1,2-hydroxystearate A2: Magnesium stearate B1: Complex hydroxide salt of lithium and aluminum; [L
iAl ₂ (OH) ₆ ] ₂ CO ₃ .1.6H ₂ O B3: Calcium stearate C1: Magnesium salt of diterpenic acids; mixture of dehydroabietic acid and magnesium dehydroabietic acid (magnesium salt content is 30% by weight) T1 : Talc; average particle diameter (light scattering method) 4.5 µm; aspect ratio (electron microscopy method) 10.3 Molding of polypropylene resin and evaluation of physical properties and the like of the molded article were performed as follows.

-0.05 parts by weight of tetrakis [methylene-3,5-di-t-butyl-4-hydroxyphenyl] propionate] methane per 100 parts by weight of the pre-mixed polypropylene resin;
0.05 parts by weight of tris (2,4-di-t-butylphenyl) phosphite and the types and amounts of additives shown in Table 2 were blended and premixed with a Henschel mixer for 5 minutes.

[0063] - pelletizing the preliminary mixture 50mmφ extruder (full flight type screw, cylinder: L / D = 28, with a vent)
And pelletized at a resin temperature of 230 ° C.

Bending test (measurement of bending elastic modulus and bending strength) Using an injection molding machine having a mold clamping force of 150 tons, the above pellets were used as a bending test piece having a length of 5 inches, 1/2 inch and a thickness of 1/8 inch. Was molded. The resin temperature is 230 ° C and the mold cooling water temperature is 40 ° C. Using the obtained test piece, JIS
The flexural modulus (rigidity) and flexural strength were measured according to K7110.

Measurement of Specific Gravity The above-mentioned bending test piece was measured according to JIS K7112.

Molding of Box Molded Article The above-mentioned pellets were molded into the box molded article shown in FIGS. 1 and 2 using an injection molding machine having a mold clamping force of 150 tons. FIG. 1 is a perspective view from the opening surface, and FIG. 2 is a perspective view from the bottom surface. This box-shaped molded product has a width a of 100 mm, a length b of 130 mm, a height c of 70 mm, and a distance d between outer surfaces of the long side of the opening of 105 m when there is no shrinkage and warpage.
m and thickness t are 2.0 mm. The actual molded product has a shape different from these dimensions due to shrinkage of the resin or the like. The gate position A is provided at the center of the bottom surface.

The molding was performed under the conditions of a resin temperature of 200 ° C., a mold cooling water temperature of 30 ° C., a filling time of 1.5 seconds, a holding pressure of 50 MPa, a holding time of 5 seconds, and a cooling time of 8 seconds.

Measurement of the amount of warpage deformation The measured minimum distance d 'between the outer surfaces of the long sides of the opening of the box-shaped product obtained by the above method was measured, and dd' was taken as the amount of warpage deformation (mm).

Surface Impact Strength Measurement In addition, on the bottom surface of the box-shaped molded product, the distance e from the short side is 100 mm on a line connecting the centers of the short sides.
g of iron ball was dropped, and a ball-drop impact test was performed in an atmosphere of 23 ° C., and the surface impact strength (g · cm) was calculated from the minimum height at which cracks occurred.

Example 1 [Preparation of solid titanium compound] The solid titanium compound was prepared according to the method of Example 1 in JP-A-11-1583.

That is, 10 g of diethoxymagnesium and 80 ml of toluene were charged into a 200 ml round bottom flask which was sufficiently replaced with nitrogen gas and equipped with a stirrer.
It was in a suspended state. Then, 20 ml of titanium tetrachloride was added to the suspension solution, and the temperature was raised. When the temperature reached 80 ° C., 2.7 ml of di-n-butyl phthalate was added, and the temperature was further increased by 1 ml.
10 ° C. Thereafter, the reaction was performed while stirring at a temperature of 110 ° C. for 2 hours. After the reaction, 90
Washed twice with 100 ml of toluene at 20 ° C., and newly added 20 ml of titanium tetrachloride and 80 ml of toluene.
And reacted while stirring for 2 hours. After the completion of the reaction, the solid was washed 10 times with 100 ml of n-heptane at 40 ° C. to obtain a solid titanium compound. The solid-liquid in the solid titanium compound was separated, and the titanium content in the solid component was measured to be 2.98% by weight.

[Preliminary polymerization] Inner volume 1 l with N ₂ substitution
After charging 200 ml of purified n-hexane, 50 mmol of triethylaluminum, 10 mmol of dicyclopentyldimethoxysilane, and 5 mmol of solid titanium compound component in terms of Ti atom, the propylene was adjusted to about 2 g per 1 g of solid titanium catalyst component. 3
It was continuously introduced into the autoclave for 0 minutes. The temperature during this period was kept at 10 ° C. After 30 minutes, the reaction was stopped, and the inside of the autoclave was sufficiently replaced with N2. The solid component of the obtained slurry was washed four times with purified n-hexane to obtain a solid titanium catalyst. As a result of analyzing the solid titanium catalyst, 2.4 g of propylene was polymerized per 1 g of the solid titanium compound.

[Main polymerization] N ₂ -substituted internal volume 400
After 100 kg of propylene was added to 1 l of the polymerization tank, 75 mmol of triethylaluminum, 37.5 mmol of dicyclopentyldimethoxysilane, and hydrogen gas were charged, the internal temperature of the polymerization tank was raised to 65 ° C., and the prepolymerization was performed. 0.25 mmol of the solid titanium catalyst as Ti atom
I was charged. Then, the internal temperature of the polymerization tank was raised to 70 ° C.
The polymerization of homopolypropylene was carried out for a period of time. After completion of the polymerization, 50 ml of methanol was added as a polymerization terminator to stop the reaction, and then 30 k of liquid propylene was added to the polymerization tank.
After stirring for 1 hour, the mixture was allowed to stand and the resin particles were settled, and a liquid propylene portion was extracted from an upper portion of the polymerization tank by an extraction nozzle. The resin slurry in the polymerization tank was sent to a flash tank and separated from unreacted propylene to obtain a white granular PP resin (PP-1).

Using the obtained PP resin, an ethylene content measurement, a boiling heptane insoluble fraction measurement, an isotactic pentad fraction measurement of the boiling heptane insoluble fraction, and a temperature rise elution fractionation measurement were carried out as described above. The results are shown in Table 1. Using the obtained resin, premixing, pelletization, bending test, specific gravity measurement, molding of a box-shaped molded product, measurement of the amount of warpage deformation, and measurement of surface impact strength were performed as described above, and the results are shown in Table 2.

Examples 2 to 4 and Comparative Examples 1 and 2 In the main polymerization, the hydrogen gas concentration was adjusted to obtain various MFRs.
The same operation as in Example 1 was performed except that a PP resin having a value (PP-2 to 6) was obtained, and the results are shown in Tables 1 and 2.

Comparative Example 3 Diphenylmethoxysilane was used in place of dicyclopentyldimethoxysilane used in the main polymerization of Example 1,
The same operation as in Example 1 was performed except that the PP resin (PP-7) was obtained, and the results are shown in Tables 1 and 2.

Example 5 The same operation as in Example 1 was carried out except that a mixture of PP-1 and PP-6 at a ratio of 7: 3 (PP-8) was used as the PP resin, and the results were shown in Table 1. 1 and Table 2.

Comparative Example 4 Homopolypropylene was polymerized for 3 hours by the same operation as the main polymerization of Example 1, and after purging unreacted gas in the system, ethylene and propylene were added to 35/65.
, And the amount of hydrogen gas was adjusted so as to obtain the MFR shown in Table 1. The internal temperature of the polymerization tank was 55 ° C, and the total pressure was 0.5M.
Polymerization was performed at Pa for 60 minutes.

After completion of the polymerization, the reaction was stopped by adding 50 ml of methanol as a polymerization terminator, and then 30 kg of liquid propylene was added to the polymerization tank. After stirring for 1 hour, the mixture was allowed to stand to sediment the resin particles. The portion was extracted from the upper part of the polymerization tank with an extraction nozzle attached.
The resin slurry in the polymerization tank was sent to a flash tank and separated from unreacted propylene to obtain a white granular block type PP resin (PP-9).

Thereafter, the same operation as in Example 1 was carried out, and the results are shown in Tables 1 and 2. Example 6 As PP resin, a mixture of PP-1 and PP-9 in a ratio of 4: 6 (PP- The same operation as in Example 1 was performed except that 10) was used, and the results are shown in Tables 1 and 2.

Examples 7 to 11 and Comparative Examples 5 to 13 The same operations as in Example 1 were carried out except that the types and amounts of the additives were changed to the values shown in Table 2, and the results are shown in Tables 1 and 2. Was.

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[Table 1]

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[Table 2]

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[Table 3]

[Brief description of the drawings]

FIG. 1 is a schematic view (a perspective view from an opening surface) of a box-shaped molded product molded for evaluation of warpage deformation.

FIG. 2 is a schematic view (a perspective view from the bottom) of a box-shaped molded product molded for evaluation of warpage deformation.

[Explanation of symbols]

 a: Width b: Length c: Height d: Distance between outer surfaces of long side of opening e: Distance from short side of surface impact strength measurement position A: Gate position B: Surface impact strength measurement position

Claims (1)

[Claims] (A) MFR is 6 to 50 g / 10 min.
Has a boiling heptane insoluble content of 85% by weight or more,
100 parts by weight of a highly crystalline polypropylene resin having a main elution peak of 116 ° C. or higher and a half width temperature of the main elution peak of less than 3.7 ° C. in the temperature-rise elution fractionation, and (B) magnesium salt of diterpenic acid 0.1 ~ 2 parts by weight,
(C) 0.5 to 6 parts by weight of talc, (D) 0.03 to 1 part by weight of magnesium 1,2-hydroxystearate,
(E) A polypropylene resin composition comprising 0.01 to 5 parts by weight of an inorganic neutralizer.