JPH08239523A - Polypropylene resin composition, composition for producing film and the film - Google Patents

Abstract

PURPOSE: To obtain a polypropylene resin composition for the use of film formation capable of giving a film having excellent transparency and shock resistance and modified anti-blocking properties and slipperiness in the case where a basic resin is a propylene single polymer, and a film having excellent slipperiness by adding a small amount of a slipping agent in the cease where the basic resin is a propylene-ethylene randam copolymer. CONSTITUTION: This polypropylene resin composition is obtained by compounding 100 pts.wt. of a polypropylene resin with (A) 0.01-1.0 pts.wt. of an anti-blocking agent, (B) 0.01-0.5 pts.wt. of a fatty acid amide slipping agent and optionally (C) 0.01-1.0 pts.wt. of a phenolic antioxidant and/or a phosphorous-containing antioxidant. The anti-blocking agent is a surface-treated synthetic silica compound, and has a specific surface area determined by BET method of >=150m<2> /g and a DBA value of <=400meq/kg.

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, a film composition and a film, and more particularly, it retains good transparency and impact resistance when the base resin is a propylene homopolymer. In addition, it is possible to provide a film with significantly improved anti-blocking properties and slip properties, and in the case of a propylene-ethylene random copolymer, a film with good slip properties is provided without increasing the amount of lubricant added. The present invention relates to a polypropylene resin composition, a film composition and a film that can be used.

[0002]

2. Description of the Related Art Conventionally, polypropylene-based resin films have been used as packaging materials in a wide range of fields including food packaging because of their strength and transparency. This polypropylene-based resin film is usually an anti-blocking agent such as silica or zeolite in order to improve handling workability, such as preventing winding wrinkles during molding and improving the opening property when filling the contents. And a lubricant such as fatty acid amide is added. In addition, such a polypropylene-based resin film is generally formed at a temperature of about 20 to 40 ° C for 1 to several days in order to promote migration of a lubricant to the film surface after molding and to develop stable slipperiness. It is being stored (aged). By the way, in particular, homopolypropylene having a narrow molecular weight distribution and a short relaxation time τ at the same melt index (MI) is less likely to be oriented during molding, and therefore, even if the take-up speed is increased, it has excellent impact resistance and transparency. It has the feature of being obtained. However, on the other hand, in order to improve the anti-blocking property, it is necessary to add a large amount of the anti-blocking agent, and as a result, there is a drawback that the anti-blocking agent may not exhibit sufficient lubricity, probably because of the adsorption of the lubricant. Have

On the other hand, a propylene-ethylene random copolymer having a low content of a low molecular weight component has a feature of being particularly excellent in adhesion resistance because the bleeding of the low molecular weight component on the film surface is small. However, on the other hand, there is a drawback in that slipperiness is not easily exhibited even if a lubricant is added in an amount sufficient to improve slipperiness. In such a case, it is not preferable to add a large amount of a lubricant for improving the slipperiness because it causes bleeding of the film and adhesion to the chamber of a molding machine during film formation. In order to improve the slipperiness of a polyolefin-based film, a method has been proposed in which an antiblocking agent having an OH group content on the surface thereof is not more than a specific amount is used (Japanese Patent Laid-Open No. 4-22044).
3 gazette). In this method, the lubricant is likely to be transferred to the film surface, possibly because the lubricant is less likely to be adsorbed on the surface of the anti-blocking agent, and the slipperiness may be improved. However, in this method, among the disclosed antiblocking agents, those other than the synthetic silica-based agents generally have high hardness or are not porous. When an antiblocking agent having a high hardness is used, scratch resistance, which is one of the important characteristics of polypropylene resins, deteriorates. When a non-porous anti-blocking agent is used, it is necessary to add a large amount in order to impart anti-blocking properties, but even when a large amount is added, the effect of improving anti-blocking properties is not always sufficiently exhibited. There is also. Further, among the synthetic silica-based materials, those having a small amount of OH groups on the surface have a small specific surface area, so that the diameter of the primary particles is large and the binding of the primary particles is weak. As a result, the anti-blocking agent particles collapse during kneading and molding, making it difficult to form irregularities on the film surface, resulting in poor anti-blocking properties.

[0004]

Under the above circumstances, the present invention maintains good transparency and impact resistance as well as antiblocking property and antiblocking property, especially when the base resin is a homopolymer of propylene. A polypropylene resin capable of giving a film having remarkably improved slipperiness, and in the case of a propylene-ethylene random copolymer, a polypropylene resin capable of giving a film having good slipperiness even if the addition amount of a lubricant is not significantly increased. It is intended to provide a composition, a composition for a film and a film.

[0005]

The present inventors have previously found that when a synthetic silica antiblocking agent having a specific surface area and having silanol groups on the surface reduced by surface treatment is used, It has been found that a polypropylene resin composition for film molding, which is excellent in color resistance during processing, anti-blocking property and scratch resistance, can be obtained (Japanese Patent Application No. 6-27860). The present inventors have conducted further research in order to develop a polypropylene resin composition for film formation, which has the above-mentioned preferable properties. As a result, in the above-mentioned surface-treated synthetic silica-based anti-blocking agent, in order to reduce the silanol groups on the surface, which may cause the adsorption of the lubricant by the surface treatment, the base synthetic silica has a large surface area, and during kneading and molding. It is possible to use a material that does not easily collapse. Further, by using such a surface-treated synthetic silica-based anti-blocking agent, in the propylene homopolymer, good slipperiness can be obtained even if the anti-blocking agent is added in an amount sufficient to improve the anti-blocking property. It has been found that the propylene-ethylene random copolymer can be expressed, and good slipperiness can be expressed in the propylene-ethylene random copolymer without increasing the addition amount of the lubricant so much. The present invention has been completed based on such findings.

That is, in the present invention, (A) the specific surface area measured by the BET method is 150 m ² / g or more and the DBA value is 40 per 100 parts by weight of the polypropylene resin.
0.01 to 1.0 parts by weight of a surface-treated synthetic silica-based anti-blocking agent of 0 meq / kg or less,
(B) 0.01 to 0.5 parts by weight of a fatty acid amide lubricant, and optionally (C) 0.01 to 1.0 parts by weight of a phenolic antioxidant and / or a phosphorus antioxidant. A characteristic polypropylene resin composition is provided. The present invention also provides a film forming composition comprising the resin composition, and a film produced by forming the resin composition into a film.

In the resin composition of the present invention, examples of the polypropylene resin used as the base resin include propylene homopolymer, random copolymer of propylene and ethylene, propylene-ethylene-butene-1 ternary copolymer. Examples thereof include a polymer and a propylene-ethylene block copolymer (particularly one having a relatively small amount of propylene-ethylene random copolymer component). These polypropylene-based resins may contain a suitable modifier such as ethylene-propylene rubber (EPR). As polypropylene resin, propylene homopolymer When the polymer used is obtained by frequency dispersion measurement at a temperature ^{_{175 ℃ ω 0 = 10 0 rad}} / relaxation time in seconds tau (second) and Mel index [MI (g / 10
Min): 230 ° C., 2.16 kgf] satisfying the formula τ ≦ 0.65-0.025MI, anti-blocking property and slip property while maintaining good transparency and impact resistance. Is preferable, and those satisfying the formula τ ≦ 0.60-0.025MI are more preferable because transparency and impact resistance are further improved.

The relaxation time τ is calculated by Rheometrics
In a rotary rheometer manufactured by Cone Plate (25
mmφ, cone angle: 0.10 radian)
Ω when frequency dispersion measurement was performed at 175 ° C₀
= 10⁰The relaxation time τ in rad / sec.
It is calculated more. That is, the resin pellet
Complex modulus G measured by^*(Iω) is the stress σ^*And distortion
Only γ^*By σ^*/ Γ ^*When defined by^*(Iω) = σ^*/ Γ^*= G ′ (ω) + iG ″ (ω) τ (ω) = G ′ (ω) / ωG ″ (ω) (where G ′ is the storage elastic modulus and G ″ is the loss elastic modulus
Is shown. ), It is the value obtained.

The melt index (MI) is J
According to ISK-7210, temperature 230 ° C, load 2.16
It is a value measured under the condition of kgf. On the other hand, as the polypropylene resin, propylene and in the case of using a copolymer with other olefins, n- hexane soluble content when performing the extraction with boiling n- hexane (wt%: less, C ₆ soluble fraction Is less than 4.5% by weight, and the effect of improving the slipperiness is large, which is preferable. The C ₆ soluble content is
It is the value obtained by extracting the sample with boiling n-hexane using a heat-retaining Soxhlet extractor. The polypropylene resin may be used alone or in combination of two or more. In the resin composition of the present invention,
As the component (A), a surface-treated synthetic silica antiblocking agent is used. This synthetic silica-based antiblocking agent needs to have a specific surface area of 150 m ² / g or more as measured by the BET method. When the specific surface area is less than 150 m ² / g, the antiblocking property is insufficient and the object of the present invention cannot be achieved. In order to further improve the anti-blocking property, the specific surface area is preferably 200 m ² / g or more, particularly 200 to 100
0 m ² / g, especially 250~1000m ² / g are preferred. The measurement by the BET method is according to the method described in "Journal of the American Chemical Society (J. Amer. Chem. Soc.)", Volume 60, Page 309 (1983). went.

The surface-treated synthetic silica-based antiblocking agent has a DBA value of 400 meq / kg.
It must be: This DBA value is an index showing the amount of silanol groups on the surface, and its value is 400 meq.
If it exceeds / kg, the effect of improving the slipperiness will be insufficient and the object of the present invention will not be achieved. The DBA value is preferably 300 meq / kg or less, and particularly preferably 250 meq / kg or less, in order to better exert the effect of improving the slipperiness. The DBA value was 0.01 N per 1 g after firing the sample at 180 ° C for 2 hours and allowing it to cool in a desiccator.
100 ml of a toluene solution of di-n-butylamine (DBA) was added, the mixture was stirred with a stirrer for 1 hour, left to stand overnight, 5 ml of the supernatant was taken, and a water / methanol mixture (weight ratio 1/1) was added, p on the pH meter
It is a value obtained by titrating with 0.01N hydrochloric acid while measuring H.

The surface treatment method of the synthetic silica-based antiblocking agent is not particularly limited, and a conventionally known method,
For example, various methods such as a method of coating a fatty acid metal salt or wax on the surface of silica, or a method of substituting a silanol group on the surface of silica with an organic substance by using a coupling agent such as silane, silicone oil, or modified silicone oil are used. It can be carried out. The surface treatment method of the anti-blocking agent using the silane coupling agent or silicone oil is not particularly limited, and various known methods can be used. For example, the following method can be used. In the case of silane coupling agent: A solution of a silane coupling agent such as water or an organic solvent is prepared, an anti-blocking agent is immersed in this solution, and then the solvent is removed by filtration, compression, centrifugation, or the like, and dried. While stirring the anti-blocking agent using a mixer or blender, a silane coupling agent or its water,
Spray a solution such as an organic solvent and dry. In the case of silicone oil, etc. After dipping the anti-blocking agent in a solution of silicone oil (diluted in toluene, xylene, petroleum ether, isopropyl alcohol, volatile silicone oil, etc.), remove the solvent and heat bake. The anti-blocking agent is sprayed with a silicone oil or a solution thereof while stirring with a mixer or a blender, and heat-baked.

The silicone oil or modified silicone oil that can be used for the surface treatment of such an anti-blocking agent is not particularly limited, but examples of the silicone oil include dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane. , Fluoropolysiloxane, and the like. Modified silicone oils include those having an organic functional group at the side chain of dimethylpolysiloxane, those having an organic functional group at the end of the molecular chain, and those at both the side chain and the end. Some have functional groups, for example, carbinol modified polysiloxane, polyether modified polysiloxane, amino modified polysiloxane, epoxy modified polysiloxane, carboxyl modified polysiloxane, methacryl modified polysiloxane, mercapto. Sex polysiloxane, phenol-modified polysiloxane, alkyl-modified polysiloxane, methylstyryl group-modified polysiloxane, and fluorine-modified polysiloxanes.

On the other hand, the silane coupling agent which can be used for the surface treatment of the anti-blocking agent is not particularly limited, and examples thereof include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane and vinyltrioxide. Examples include acetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane.

In the resin composition of the present invention, the surface-treated synthetic silica-based antiblocking agent as the component (A) may be used alone or in combination of two or more kinds. Further, the blending amount must be selected in the range of 0.01 to 1.0 parts by weight with respect to 100 parts by weight of the polypropylene resin. If this amount is less than 0.01 part by weight, the anti-blocking property will be insufficient, and 1.0
When it exceeds the weight part, the transparency decreases. From the viewpoint of the balance between anti-blocking property and transparency, the preferable blending amount is
It is in the range of 0.03 to 0.7 parts by weight, particularly preferably in the range of 0.05 to 0.5 parts by weight. From the viewpoint of antiblocking property and transparency, the average particle size of this antiblocking agent is 1 to 6 μm as measured by the Coulter counter method.
About m is preferable. In the resin composition of the present invention,
A fatty acid amide lubricant is used as the component (B). The fatty acid amide lubricant is not particularly limited, and conventionally known ones such as erucic acid amide, behenic acid amide,
Oleic acid amide, stearic acid amide, N-stearyl lauric acid amide, N-stearyl stearic acid amide, N-stearyl behenic acid amide, N-stearyl erucic acid amide, N-oleyl oleic acid amide, N-oleyl behenic acid amide, N -Lauryl erucamide,
Elenbis oleic acid amide, ethylene bis stearic acid amide, hexamethylene bis oleic acid amide, hexamethylene bis erucic acid amide and the like can be mentioned.

In the resin composition of the present invention, these fatty acid amide lubricants may be used alone,
You may use it in combination of 2 or more type. In addition, the blending amount is 0.0 with respect to 100 parts by weight of the polypropylene resin.
It is necessary to select in the range of 1 to 0.5 parts by weight. If the blending amount is less than 0.01 part by weight, the slipperiness is insufficient, and if the blending amount exceeds 0.5 part by weight, bleed whitening on the film surface and adhesion of the lubricant to the chamber of the molding machine become remarkable. . From the viewpoint of making the slipperiness good, and suppressing the bleeding and whitening of the film surface and the adhesion of the lubricant to the chamber of the molding machine, etc., the preferable compounding amount is 0.01 to 0.
The range is 3 parts by weight, and the range of 0.02 to 0.2 parts by weight is particularly preferable.

In the resin composition of the present invention, in addition to the above-mentioned components (A) and (B), in some cases (C)
As a component, a phenolic antioxidant or a phosphorus antioxidant can be blended. There is no particular limitation on the phenolic antioxidant, and conventionally known ones such as 2,
6-di-t-butyl-4-methylphenol, n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-
Tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2-t-butyl-
6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1
-(2-Hydroxy-3,5-di-t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate, triethylene glycol-bis- [3- (3
-T-butyl-5-methyl-4-hydroxyphenyl)
Propionate], 1,6-hexanediol-bis-
[3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,9-bis [1,1-di-
Methyl-2- [β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl]
-2,4,8,10-Tetraoxaspiro [5,5] undecane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) Benzene, tris (3,5-di-t-butyl-4-
Hydroxybenzyl) isocyanurate, tris (4-
t-butyl-2,6-di-methyl-3-hydroxybenzyl) isocyanurate and the like.

The phosphorus antioxidant is also not particularly limited, and conventionally known ones such as tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and bis (2). , 4-Di-t-butylphenyl) pentaerythritol-di-phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, bis (2,4,6) -Tri-t-butylphenyl) pentaerythritol-di-phosphite, methylenebis (2,4
-Di-t-butylphenyl) octyl phosphite, tetrakis (2,4-di-t-butylphenyl) -4,
4'-biphenylene-di-phosphonite, tetrakis (2,4-di-t-butyl-5-methylphenyl)-
4,4′-biphenylene-di-phosphonite and the like can be mentioned.

In the resin composition of the present invention, as the component (C), the above phenolic antioxidants may be used alone or in combination of two or more. Also,
The phosphorus antioxidants may be used alone or in combination of two or more. Further, one or more phenolic antioxidants and one or more phosphorus antioxidants may be used in combination. The antioxidant of the component (C) is 0.0 with respect to 100 parts by weight of the polypropylene resin.
It is mixed in a ratio of 1 to 1.0 parts by weight. This blended amount is 0.0
If it is less than 1 part by weight, the effect of adding the antioxidant may not be sufficiently exhibited, and the thermal stability during molding may be insufficient.
On the other hand, if the amount exceeds 1.0 part by weight, the effect is not improved for the amount, and it is rather economically disadvantageous. From the viewpoint of the antioxidant effect and economical efficiency, the preferable blending amount is in the range of 0.04 to 0.8 parts by weight, and particularly preferably in the range of 0.07 to 0.5 parts by weight.

The resin composition of the present invention contains various additives that are commonly used, such as a residual chlorine neutralizer, an antistatic agent, an antifogging agent, an ultraviolet absorber, and the like, as long as the object of the present invention is not impaired. A hindered amine type light stabilizer (HALS) and the like can be added. The method for preparing the polypropylene-based resin composition of the present invention is not particularly limited, and a conventionally known method such as the polypropylene-based resin, the component (A),
A method of mixing the component (B) and the component (C) and various additives used as necessary with a tumbler blender, a Henschel mixer, or the like, and after the mixing, melt kneading using a single-screw extruder or a multi-screw extruder. A method of granulating, or a method of melt-kneading and granulating with a kneader, Banbury mixer or the like can be adopted. In the preparation of this resin composition, a masterbatch was prepared in advance with a small amount of a polypropylene resin and various desired additives, and using this and the polypropylene resin, and optionally the remaining additives, the above The resin composition may be prepared in this manner.

The polypropylene resin composition of the present invention thus obtained is useful as a material for film formation, and a desired film can be obtained by forming the film. For example, the film can be formed by uniaxially or biaxially stretching the resin composition of the present invention by T-die film forming, water-cooled inflation forming, or forming into a sheet with a T-die. The film may be a single layer film or a multilayer film with another resin.

[0021]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The anti-blocking property and the slip property of the film were evaluated according to the following procedures. (1) Anti-blocking property Films are stacked on top of each other and stored in a constant temperature bath at 60 ° C for 3 hours with a load of 36 g / cm ² , and the maximum load for shearing and peeling is determined as the blocking strength, and the adhesion resistance is determined. The sex was evaluated. Test conditions are test speed: 20
mm / min, load cell: 2 kg. (2) Sliding property According to ASTM D-1894, the angle (θ) at which the film starts to slide when the inclined plate is tilted is measured, and the coefficient of static friction =
tan θ was determined and the slip property was evaluated. The physical properties of the polypropylene resin and the anti-blocking agent were measured according to the methods described in the text of the specification.

Examples 1 to 4 and Comparative Example 1 100 parts by weight of a propylene homopolymer having an MI of 7.1 g / 10 minutes and a relaxation time τ of 0.39 seconds were added to 100 parts by weight of an anti-blocking agent of the type and amount shown in Table 1. Acid and erucic acid amide as a lubricant
0.1 part by weight, Irganox 1010 (pentaerythrityl tetrakis [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate], manufactured by Ciba-Geigy) 0.075 parts by weight and Irgafos 168 as a phosphorus antioxidant.
[Tris (2,4-di-t-butylphenyl) phosphite, manufactured by Ciba-Geigy] 0.075 parts by weight was kneaded by a twin-screw extruder, pelletized, and then screw diameter 4
0 mm, screw L / D = 25 single screw extruder, die width 500 mm, die lip 0.6 mm coat hanger type T
-A die was attached, and the above kneaded and pelletized raw material was molded at a processing temperature of 215 ° C and a cooling roll temperature of 30 ° C to obtain a cast film having a thickness of 30 µm. This film was stored at a temperature of 40 ° C. for 24 hours to stabilize its slipperiness, and then conditioned at a temperature of 23 ± 2 ° C. and a humidity of 50 ± 10% for 16 hours or more. Was evaluated. The results are shown in Table 1.

[0023]

[Table 1]

Examples 5 to 8 and Comparative Examples 2 to 5 MI: 6.7 g / 10 minutes, ethylene unit content: 3.4% by weight, C ₆ soluble content: 3.2% by weight propylene-ethylene random To 100 parts by weight of the copolymer, 0.25 parts by weight of the anti-blocking agent shown in Table 2, 0.08 parts by weight of erucamide as a lubricant, and Irganox 1010 (as mentioned above) as a phenol-based antioxidant are added. 03 parts by weight and Irgafos 168 as a phosphorus-based antioxidant (supra) 0.12
After kneading and pelletizing parts by weight with a twin-screw extruder, a coat hanger type T-die with a die width of 500 mm and a die lip of 0.6 mm was attached to a single-screw extruder with a screw diameter of 40 mm and a screw L / D = 25. Kneaded and pelletized raw material is processed at 220 ℃, chill roll temperature is 30 ℃
To obtain a cast film having a thickness of 30 μm.
This film was stored at a temperature of 40 ° C. for 24 hours to stabilize the slipperiness, and then the temperature was 23 ± 2 ° C. and the humidity was 50 ± 1.
After conditioning at 0% for 16 hours or more, antiblocking property and slipperiness were evaluated. The results are shown in Table 2.

[0025]

[Table 2]

Examples 9 to 12 and Comparative Examples 6 to 9 100 parts by weight of a propylene-ethylene random copolymer having the properties shown in Table 3, 0.20 parts by weight of an anti-blocking agent shown in Table 3, and a lubricant were used. 0.08 part by weight of erucic acid amide, 0.15 part by weight of Irganox 1010 (supra) as a phenolic antioxidant and Irganox 107
6 [n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, manufactured by Ciba-Geigy] 0.07 parts by weight and Sand Starve P-EPQ [tetrakis as a phosphorus-based antioxidant. (2,4-di-
t-butylphenyl) -4,4'-biphenylene-diphosphonite, manufactured by Sand Co.] 0.035 parts by weight was kneaded by a twin-screw extruder and pelletized, and then the screw diameter was 4
0 mm, screw L / D = 25 single screw extruder, die width 500 mm, die lip 0.6 mm coat hanger type T
-A die was attached, and the above kneaded and pelletized raw material was molded at a processing temperature of 220 ° C and a cooling roll temperature of 30 ° C to obtain a cast film having a thickness of 30 µm. This film was stored at a temperature of 40 ° C. for 24 hours to stabilize the slipperiness, and then conditioned at a temperature of 23 ± 2 ° C. and a humidity of 50 ± 10% for 16 hours or more. evaluated. The results are shown in Table 2.

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

EFFECTS OF THE INVENTION The polypropylene resin composition of the present invention can sufficiently utilize the performance of the fatty acid amide lubricant by selecting a specific anti-blocking agent. Particularly, when the base resin is a propylene homopolymer, it is excellent. It is possible to provide a film which has excellent transparency and impact resistance and has significantly improved antiblocking property and slipperiness. Further, in the case of a propylene-ethylene random copolymer, the composition of the present invention can give a film having good slipperiness even if the amount of the lubricant added is not significantly increased.

Claims (6)

[Claims] 1. A specific surface area measured by the (A) BET method is 150 with respect to 100 parts by weight of a polypropylene resin.
m ² / g or more and DBA value is 400 meq / kg
The following surface-treated synthetic silica-based antiblocking agent 0.01 to 1.0 parts by weight, and (B) a fatty acid amide-based lubricant
A polypropylene-based resin composition comprising 0.01 to 0.5 part by weight. 2. The specific surface area measured by the (A) BET method is 150 with respect to 100 parts by weight of the polypropylene resin.
m ² / g or more and DBA value is 400 meq / kg
The following surface-treated synthetic silica anti-blocking agent 0.01 to 1.0 parts by weight, (B) fatty acid amide lubricant 0.0
1-0.5 parts by weight, and (C) a phenol-based antioxidant and / or a phosphorus-based antioxidant 0.01-1.0 parts by weight are blended, and the polypropylene resin composition characterized by the above-mentioned. 3. The polypropylene resin has a temperature of 175 ° C.
Ω ₀ = 10 ⁰ r obtained by frequency dispersion measurement at
The propylene homopolymer in which the relationship between the relaxation time τ (second) at ad / sec and the mel index [MI (g / 10 min): 230 ° C., 2.16 kgf] satisfies the formula τ ≦ 0.65-0.025MI. The composition according to claim 1 or 2, which is 4. The polypropylene-based resin is a copolymer of propylene and another olefin having an n-hexane soluble content of 4.5% by weight or less when extracted with boiling n-hexane. Or the composition according to 2. 5. A film-molding composition comprising the composition according to claim 1 or 2. 6. A film produced by forming the composition according to claim 1 or 2.