JP2006274114A - Polypropylene resin composition for extrusion coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a propylene resin composition having excellent extrusion coating properties. <P>SOLUTION: The polypropylene resin composition comprises 99-80 wt.% of a polypropylene resin (A) that is prepared by using a metallocene catalyst, has [1] 20-50 g/10 minutes melt flow rate (ASTMD1238, 230°C, 2.16kg), [2]≥155°C melting point and [3] ≤0.05 mol% total of 2,1-bond amount and 1,3-bond amount measured by<SP>13</SP>C-NMR and 1-20 wt.% of a high-pressure polyethylene (B). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polypropylene resin composition for extrusion coating, and more particularly to a polypropylene resin composition capable of coating paper and plastic films at high speed.

Polypropylene resin is excellent in mechanical strength and food hygiene, and is used by being laminated with paper and other plastic films. One method of laminating polyolefin resin on paper or other plastic films is extrusion coating. In this method, since the melt tension of the polypropylene resin is small, the polypropylene resin extruded from the T-die has a problem that the neck-in is large, the ear portion is thick and uniform coating cannot be performed, and wide coating cannot be performed. In order to solve these problems, the melt tension of the polypropylene resin is usually improved by blending a small amount of high-pressure polyethylene into the polypropylene resin. However, since polypropylene resin has excellent melt stretchability, it can be extrusion coated at a high speed. However, polypropylene resin blended with high-pressure polyethylene to improve melt tension has low melt stretchability. For this reason, when extruded at a high speed, a phenomenon such as ear shaking occurs, and there is a problem that extrusion coating cannot be performed at a high speed. In JP-A-2002-363356, it can be improved by using a polypropylene resin obtained by using a metallocene catalyst, but it is still insufficient. Therefore, the appearance of a polypropylene resin composition for extrusion coating that is further excellent in high-speed extrusion moldability is desired.
JP 2002-363356 A

  An object of the present invention is to provide a polypropylene composition for extrusion coating, which is excellent in high-speed extrusion moldability, in which the problems of the conventional techniques are improved.

The polypropylene composition according to the present invention has a melt flow rate (ASTMD 1238, 230 ° C., load 2.16 kg) adjusted using a metallocene catalyst of 20 to 50 g / 10 min, a melting point of 155 ° C. or higher, and ¹³ C- 99 to 80% by weight of polypropylene resin (A) having a sum of 2,1-bond amount and 1,3-bond amount measured by NMR of 0.05 mol% or less, and high-pressure polyethylene (B) 1 to 20% by weight %. The polypropylene resin (A) preferably has an Mw / Mn measured by a gel permeation chromatograph (GPC) method in the range of 4.0 or less.

The propylene resin composition according to the present invention has an excellent balance between the melt tension and the melt stretching property, and can improve the extrusion coating property and the film forming speed, in particular, due to the characteristics such as a small motor load during extrusion. .

Hereinafter, the polypropylene resin composition according to the present invention will be specifically described.
Polypropylene resin (A)
The polypropylene resin (A) of the present invention has a [1] melt flow rate (ASTMD 1238, 230 ° C., load 2.16 kg) of 20 to 50 g / 10 minutes, [2] a melting point of 155 ° C. or higher, [3 ] The sum of 2,1-bond amount and 1,3-bond amount measured by ¹³ C-NMR is 0.05 mol% or less. When a polypropylene resin having a melt flow rate within the above range is used, the resulting polypropylene resin composition is excellent in extrusion moldability, and also has excellent meltability (melt tension), and is excellent in spreadability and stable. An extrusion coating material having quality can be provided.

  The melting point measured by a differential scanning calorimeter (DSC) is preferably 155 ° C. or higher, particularly preferably 158 ° C. to 165 ° C. When the polypropylene resin (A) having a melting point in this range is used, a polypropylene resin composition capable of providing a film having excellent rigidity and heat resistance can be obtained.

The 2,1-bond amount and 1,3-bond amount measured by ¹³ C-NMR in the component of the propylene resin (A) of the present invention that is insoluble in orthodichlorobenzene at 90 ° C. and soluble in 135 ° C. orthodichlorobenzene It is desirable that the bonding amount ratio is 0.05 mol% or less. When the amount of 2,1-bonds and 1,3-bonds are large, the heat resistance of the propylene polymer is lowered. Here, the amount of 2,1-bonds and the amount of 1,3-bonds are positional irregular units based on 2,1-insertion and positional irregular units based on 1,3-insertion of all propylene monomers. And is calculated according to the method described in JP-A-7-145212.

  In the polypropylene resin (A) used in the present invention, the ratio (Mw / Mn) of the weight average molecular weight Mw and the number average molecular weight Mn measured by gel permeation chromatography is preferably 4.0 or less, more preferably. Is preferably in the range of 1.8 to 3.5, particularly preferably 1.8 to 3.0. When a polypropylene resin (A) having Mw / Mn within the above range is used, the stretching characteristics are excellent, and a stable film can be formed even by high-speed extrusion.

  The polypropylene resin (A) as described above can be prepared using a metallocene catalyst.

  The metallocene catalyst used in the present invention includes at least one compound selected from metallocene compounds and compounds capable of reacting with organometallic compounds, organoaluminum oxy compounds and metallocene compounds to form ion pairs. Furthermore, a metallocene catalyst which can be subjected to stereoregular polymerization such as an isotactic or syndiotactic structure, if necessary, is preferably a metallocene catalyst comprising a particulate carrier. Among the metallocene compounds, a crosslinkable metallocene compound that has already been published (WO01 / 27124) by an international application filed by the present applicant is preferably used.

In the above general formula [I], R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ are It is selected from hydrogen, a hydrocarbon group, and a silicon-containing group, and each may be the same or different. Such hydrocarbon groups include methyl, ethyl, n-propyl, allyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n- Linear hydrocarbon groups such as nonyl and n-decanyl; isopropyl, tert-butyl, amyl, 3-methylpentyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1 -Branched hydrocarbon groups such as methyl-1-propylbutyl group, 1,1-propylbutyl group, 1,1-dimethyl-2-methylpropyl group, 1-methyl-1-isopropyl-2-methylpropyl group; Cyclic saturated hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, norbornyl group and adamantyl group; cyclic unsaturated carbonized groups such as phenyl group, tolyl group, naphthyl group, biphenyl group, phenanthryl group and anthracenyl group A hydrogen group; Saturated hydrocarbon group substituted with cyclic unsaturated hydrocarbon group such as benzyl group, cumyl group, 1,1-diphenylethyl group, triphenylmethyl group; methoxy group, ethoxy group, phenoxy group, furyl group, N-methylamino A heteroatom-containing hydrocarbon group such as a group, N, N-dimethylamino group, N-phenylamino group, pyryl group and thienyl group. Examples of the silicon-containing group include a trimethylsilyl group, a triethylsilyl group, a dimethylphenylsilyl group, a diphenylmethylsilyl group, and a triphenylsilyl group. Further, the adjacent substituents of R ⁵ to R ¹² may be bonded to each other to form a ring. Examples of such substituted fluorenyl groups include benzofluorenyl group, dibenzofluorenyl group, octahydrodibenzofluorenyl group, octamethyloctahydrodibenzofluorenyl group, octamethyltetrahydrodicyclopentafluorenyl group, etc. Can be mentioned.

In the general formula [I], R ¹ , R ² , R ³ and R ⁴ substituted on the cyclopentadienyl ring are preferably hydrogen or a hydrocarbon group having 1 to 20 carbon atoms. Examples of the hydrocarbon group having 1 to 20 carbon atoms include the hydrocarbon groups described above. More preferably, R ¹ and R ³ are hydrocarbon groups having 1 to 20 carbon atoms.

In the general formula [I], R ⁵ to R ¹² substituted on the fluorene ring are preferably hydrocarbon groups having 1 to 20 carbon atoms. Examples of the hydrocarbon group having 1 to 20 carbon atoms include the hydrocarbon groups described above. The adjacent substituents of R ⁵ to R ¹² may be bonded to each other to form a ring.

In the general formula [I], Y that bridges the cyclopentadienyl ring and the fluorenyl ring is preferably a group 14 element, more preferably carbon, silicon, or germanium, and further preferably a carbon atom. R ¹³ and R ¹⁴ substituted for Y are preferably hydrocarbon groups having 1 to 20 carbon atoms. These may be the same or different from each other, and may be bonded to each other to form a ring. Examples of the hydrocarbon group having 1 to 20 carbon atoms include the hydrocarbon groups described above.

  In the general formula [I], M is preferably a Group 4 transition metal, more preferably Ti, Zr, Hf and the like. Q is selected from the same or different combinations from halogen, a hydrocarbon group, an anionic ligand, or a neutral ligand capable of coordinating with a lone pair of electrons. j is an integer of 1 to 4, and when j is 2 or more, Qs may be the same or different from each other. Specific examples of the halogen include fluorine, chlorine, bromine and iodine, and specific examples of the hydrocarbon group include those described above. Specific examples of the anionic ligand include alkoxy groups such as methoxy, tert-butoxy and phenoxy, carboxylate groups such as acetate and benzoate, and sulfonate groups such as mesylate and tosylate. Specific examples of neutral ligands that can coordinate with a lone pair include organophosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, diphenylmethylphosphine, tetrahydrofuran, diethyl ether, dioxane, 1,2-dimethoxy. And ethers such as ethane. At least one Q is preferably a halogen or an alkyl group.

  Examples of such a bridged metallocene compound include isopropylidene (3-t-butyl-5-methylcyclopentadienyl) (3,6-di-t-butylfluorenyl) zirconium dichloride, isopropylidene (3-tert- Butyl-5-methyl-cyclopentadienyl) (fluorenyl) zirconium dichloride, isopropylidene (3-tert-butyl-5-methyl-cyclopentadienyl) (3,6-ditert-butylfluorenyl) zirconium dichloride Diphenylmethylene (3-tert-butyl-5-methyl-cyclopentadienyl) (fluorenyl) zirconium dichloride, diphenylmethylene (3-tert-butyl-5-methyl-cyclopentadienyl) (2,7-ditert -Butylfluorenyl) zirconium Dichloride, diphenylmethylene (3-tert-butyl-5-methyl-cyclopentadienyl) (3,6-ditert-butylfluorenyl) zirconium dichloride, 1-phenylethylidene (4-tert-butyl-2-methyl) -Cyclopentadienyl) (octamethyloctahydrodibenzofluorenyl) zirconium dichloride and the like are preferably used.

  In the metallocene catalyst according to the present invention, an ion pair is formed by reacting with an organometallic compound, an organoaluminum oxy compound, and a transition metal compound used together with the Group 4 transition metal compound represented by the general formula [I]. At least one compound selected from the compounds to be used, and the particulate carrier used as necessary, the compounds disclosed in the above-mentioned publications (WO01 / 27124) and JP-A-11-315109 by the present applicant Can be used without limitation.

High pressure polyethylene (B)
The high pressure polyethylene (B) used in the present invention is a polyethylene having a long chain branch obtained by radical polymerization of ethylene in the presence of peroxide at a pressure of 100 kg / cm 2 or more. The preferable melt flow rate (ASTMD 1238, 190 ° C., load 2.16 kg) of the high pressure polyethylene (B) is in the range of 0.01 to 100 g / 10 minutes, preferably 0.1 to 10 g / 10 minutes. The density (ASTMD 1505) is usually in the range of 0.900 to 0.940 g / cm 3, preferably 0.910 to 0.930 g / cm 3.

Polypropylene resin composition The polypropylene resin composition according to the present invention comprises 99 to 80 wt%, preferably 95 wt% of polypropylene resin (A) with respect to 100 wt% of the total of polypropylene resin (A) and high-pressure polyethylene (B). ˜85 wt%, and high pressure polyethylene (B) is contained in an amount of 1 to 20 wt%, preferably 5 to 15 wt%. In the polypropylene resin composition according to the present invention, in addition to the components (A) and (B), an antioxidant, a heat stabilizer, a light stabilizer, a weather stabilizer, and an antistatic agent may be used as necessary. Other additives such as a slip agent, an antiblocking agent, a hydrochloric acid absorbent, and a colorant can be blended within a range that does not impair the object of the present invention.

  In order to extrusion coat the substrate surface with the polypropylene resin composition according to the present invention, the polypropylene resin composition according to the present invention is melted with an extruder, and the molten resin is melted from a T-shaped die provided at the tip of the extruder. And the molten resin is coated on the traveling substrate. By this coating, a laminate composed of a base material and a polypropylene resin composition layer can be produced. Examples of the substrate that can be used in the present invention include paper, polypropylene film, and polyester film.

  The propylene resin composition according to the present invention contains a polypropylene resin (A) having a specific melt flow rate and a melting point, which is prepared using a metallocene catalyst, and a high-pressure polyethylene resin (B). In particular, the extrusion coating property and the film forming speed can be improved from the characteristics such as excellent balance with the melt-drawing characteristics and low motor load during extrusion. Therefore, the polypropylene resin composition according to the present invention can be suitably used for applications such as paper coating and coating on a stretched polypropylene film.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by these Examples. In addition, evaluation of each characteristic in an Example etc. was performed as follows.
(1) Melt flow rate
Measured according to ASTM D1238 (230 ° C., load 2.16 kg).
(2) Melting point Measurement was performed using a differential scanning calorimeter (DSC, manufactured by Perkin Elmer). Here, the endothermic peak in the third step was defined as the melting point (Tm).

(Measurement condition)
First step: The temperature is raised to 240 ° C. at 10 ° C./min and held for 10 min.

    Second step: Decrease the temperature to 60 ° C at 10 ° C / min.

Third step: Increase the temperature to 240 ° C at 10 ° C / min.
(3) Measurement of 2,1-insertion and 1,3-insertion
^{Using 13} C-NMR, the amounts of 2,1-insertion bonds and 1,3-insertion bonds were measured according to the method described in JP-A-7-52212.
(4) GPC molecular weight distribution (Mw / Mn)
It measured as follows using GPC-150C Plus made from Waters. The separation columns were TSKgel GMH6-HT and TSKgel GMH6-HTL, the column size was 7.5 mm in inner diameter and 600 mm in length, the column temperature was 140 ° C., and o-dichlorobenzene (Wako Pure Chemical Industries) was used as the mobile phase. Industry) and BHT (Wako Pure Chemical Industries) 0.025% by weight as an antioxidant, moved at 1.0 ml / min, the sample concentration was 0.1% by weight, the sample injection volume was 500 microliters, A differential refractometer was used as a detector. Standard polystyrene used was manufactured by Tosoh Corporation for molecular weights of Mw <1000 and Mw> 4 × 10 ⁶ , and used by Pressure Chemical Co. for 1000 ≦ Mw ≦ 4 × 10 ⁶ .
(5) Extrusion coating property The polypropylene resin composition was extruded with a predetermined amount of extrusion, and the take-off speed was changed, and the end portion (ear) of the extruded film was observed with the naked eye for shaking and pulsation.
(6) Neck-in property The neck-in property was evaluated by the following neck-in amount.

  Neck-in amount = (width of lip portion of T-die (cm)) − (width of molded film (cm))

(1) Production of Solid Catalyst Support 300 g of SiO ₂ (manufactured by Dokai Chemical Co., Ltd.) was sampled into a 1 L branch flask, and 800 mL of toluene was put into a slurry. Next, the solution was transferred to a 5 L four-necked flask, and 260 mL of toluene was added. 2830 mL of methylaluminoxane (hereinafter referred to as MAO) -toluene solution (Albemarle 10 wt% solution) was introduced. The mixture was stirred for 30 minutes while remaining at room temperature. The temperature was raised to 110 ° C. over 1 hour, and the reaction was carried out for 4 hours. After completion of the reaction, it was cooled to room temperature. After cooling, the supernatant toluene was extracted and replaced with fresh toluene until the replacement rate reached 95%.
(2) Production of solid catalyst (support of metal catalyst component on support)
In a glove box, 2.0 g of isopropylidene (3-t-butyl-5-methylcyclopentadienyl) (3,6-di-t-butylfluorenyl) zirconium dichloride is weighed in a 5 L four-necked flask. It was. The flask was taken out, 0.46 liters of toluene and 1.4 liters of MAO / SiO2 / toluene slurry prepared in 1) were added under nitrogen, and the mixture was stirred for 30 minutes to carry. The resulting isopropylidene (3-t-butyl-5-methylcyclopentadienyl) (3,6-di-t-butylfluorenyl) zirconium dichloride / MAO / SiO2 / toluene slurry was 99 in n-heptane. % Substitution was performed and the final slurry volume was 4.5 liters. This operation was performed at room temperature.
(3) Production of prepolymerization catalyst 202 g of the solid catalyst component prepared in (2) above, 174 mL of triethylaluminum, and 100 L of heptane were inserted into an autoclave with a stirrer having an internal volume of 200 L, and the internal temperature was maintained at 15 to 20 ° C. to 2828 g of ethylene. Inserted and allowed to react with stirring for 180 minutes. After completion of the polymerization, the solid component was precipitated, and the supernatant was removed and washed with heptane twice. The obtained prepolymerized catalyst was resuspended in purified heptane and adjusted with heptane so that the solid catalyst component concentration was 2 g / L. This prepolymerized catalyst contained 10 g of polyethylene per 1 g of the solid catalyst component.

(4) Main polymerization Propylene is 28 kg / hour, hydrogen is 3 NL / hour, and the catalyst slurry produced in (3) is 3.1 g / hour, and triethylaluminum is 2.0 g / hour in a tubular polymerization vessel having an internal volume of 58 L. The time was continuously supplied, and polymerization was carried out in a full liquid state without a gas phase. The temperature of the tubular reactor was 30 ° C., and the pressure was 3.2 MPa / G.
The obtained slurry was sent to a vessel polymerization vessel equipped with a stirrer having an internal volume of 1000 L and further polymerized. To the polymerization vessel, propylene was supplied at 60 kg / hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase was 0.20 mol%. Polymerization was performed at a polymerization temperature of 72 ° C. and a pressure of 3.1 MPa / G.
The obtained slurry was sent to a vessel polymerization vessel equipped with a stirrer having an internal volume of 500 L and further polymerized. To the polymerization vessel, propylene was supplied at 13 kg / hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase was 0.20 mol%. Polymerization was performed at a polymerization temperature of 71 ° C. and a pressure of 3.0 MPa / G.
The obtained slurry was sent to a vessel polymerization vessel equipped with a stirrer having an internal volume of 500 L and further polymerized. Propylene was supplied to the polymerization vessel at 17 kg / hour, and hydrogen was supplied so that the hydrogen concentration in the gas phase was 0.20 mol%. Polymerization was performed at a polymerization temperature of 69 ° C. and a pressure of 3.0 MPa / G.
After vaporizing the resulting slurry, gas-solid separation was performed to obtain a propylene polymer. The resulting propylene polymer was vacuum dried at 80 ° C.
The resulting propylene polymer (A) has a melt flow rate of 25 g / 10 min, a melting point of 158 ° C., Mw / Mn of 2.0, and the sum of 2,1-bond amount and 1,3-bond amount. It was 0 mol%.

90 parts by weight of the above-obtained propylene polymer (A) and high-pressure low-density polyethylene (B) [trade name: Mirason 11P, manufactured by Mitsui Chemicals, Inc. (melt flow rate (ASTMD 1238, 190 ° C., load 2.16 kg)) : 7.2 g / 10 min, density (ASTM D1505): 0.917 g / cm ³ )] 10 parts by weight, Irgnox 1010 (trademark) [phenolic antioxidant, manufactured by Ciba Specialty Chemicals Co., Ltd.] as an antioxidant and Add 0.1 parts by weight of Irgafos168 (trademark) [phosphorus-based antioxidant, manufactured by Ciba Specialty Chemicals Co., Ltd.] and 0.1 parts by weight of calcium stearate as a hydrochloric acid absorbent, and melt knead in a single screw extruder Thus, a pellet of the polypropylene resin composition was obtained.

  The pellets of the polypropylene resin composition obtained by the above method were evaluated for laminating properties on paper at a resin temperature of 280 ° C. using a laminating machine having a screw system of 65 mmφ and a die width of 500 mm. The ears of the film-forming film were stable up to 350 m / min. The neck-in amount at that time was 85 mm.

Isopropylidene (3-tert-butyl-5-methylcyclopentadienyl) (3,6-di-tert-butylfluorenyl) zirconium dichloride is converted to 1-phenylethylidene (4-tert-butyl-2-methylcyclopenta). A propylene polymer (A) was obtained in the same manner as in Example 1 except that it was changed to (dienyl) (octamethyloctahydrodibenzofluorenyl) zirconium dichloride.
The resulting propylene polymer (A) has a melt flow rate of 25 g / 10 min, a melting point of 160 ° C., Mw / Mn of 2.0, and the sum of 2,1-bond amount and 1,3-bond amount. It was 0 mol%.

90 parts by weight of the above-obtained propylene polymer (A) and high-pressure low-density polyethylene (B) [trade name: Mirason 11P, manufactured by Mitsui Chemicals, Inc. (melt flow rate (ASTMD 1238, 190 ° C., load 2.16 kg)) : 7.2 g / 10 min, density (ASTM D1505): 0.917 g / cm ³ )] 10 parts by weight, Irgnox 1010 (trademark) [phenolic antioxidant, manufactured by Ciba Specialty Chemicals Co., Ltd.] as an antioxidant and Add 0.1 parts by weight of Irgafos168 (trademark) [phosphorus-based antioxidant, manufactured by Ciba Specialty Chemicals Co., Ltd.] and 0.1 parts by weight of calcium stearate as a hydrochloric acid absorbent, and melt knead in a single screw extruder As a result, a pellet of the polypropylene resin composition was obtained.

The pellets of the polypropylene resin composition obtained by the above method were evaluated for laminating properties on paper at a resin temperature of 280 ° C. using a laminating machine having a screw system of 65 mmφ and a die width of 500 mm. The ear of the film-forming film was stable up to 380 m / min. The neck-in amount at that time was 90 mm.
[Comparative Example 1]

  3 ml of purified toluene and 0.1 ml of a 0.5 mol / l tri-n-butylaluminum (hereinafter abbreviated as TNBA) toluene solution as an organometallic compound are mixed and stirred for 1 minute, and then silica is supported as a promoter component. 100 mg of methylaluminoxane (methylaluminoxane content 26.6% by weight) was added.

Next, 0.5 mmol / l of bis [2-methyl-4- (1-naphthyl)-(η5-1-indenyl)] dimethylsilanezirconium dichloride (hereinafter abbreviated as 2MNIZ) as a metallocene compound was added to the above solution. -Toluene solution (2 ml) was added, and the mixture was stirred at room temperature for 30 minutes and at 65 ° C for 30 minutes. Then, after cooling this solution to room temperature, toluene was distilled off under reduced pressure, a solution obtained by mixing 5 ml of purified hexane and 0.1 ml of TNBA hexane solution was added and stirred for 5 minutes. After removing the supernatant with a syringe, a mixed solution of 0.1 ml of a mixture of 5 ml of purified hexane and 0.1 ml of TNBA hexane solution was added to obtain a slurry of a catalyst for propylene polymerization.
To a 1.5 liter autoclave, 0.5 ml of a 0.5 mol / l TNBA hexane solution, 330 g of propylene and 270 ml of hydrogen were added, and the temperature was raised to 60 ° C. Thereafter, the entire propylene polymerization catalyst was injected into the autoclave and propylene polymerization was performed for 10 minutes to obtain a propylene polymer.
The resulting propylene polymer (A) has a melt flow rate of 25 g / 10 min, a melting point of 145 ° C., Mw / Mn of 2.3, and the sum of 2,1-bond amount and 1,3-bond amount. It was 0.85 mol%.

90 parts by weight of the above-obtained propylene polymer (A) and high-pressure low-density polyethylene (B) [trade name: Mirason 11P, manufactured by Mitsui Chemicals, Inc. (melt flow rate (ASTMD 1238, 190 ° C., load 2.16 kg)) : 7.2 g / 10 min, density (ASTM D1505): 0.917 g / cm ³ )] 10 parts by weight, Irgnox 1010 (trademark) [phenolic antioxidant, manufactured by Ciba Specialty Chemicals Co., Ltd.] as an antioxidant and Add 0.1 parts by weight of Irgafos168 (trademark) [phosphorus-based antioxidant, manufactured by Ciba Specialty Chemicals Co., Ltd.] and 0.1 parts by weight of calcium stearate as a hydrochloric acid absorbent, and melt knead in a single screw extruder As a result, a pellet of the polypropylene resin composition was obtained.

The pellets of the polypropylene resin composition obtained by the above method were evaluated for laminating properties on paper at a resin temperature of 280 ° C. using a laminating machine having a screw system of 65 mmφ and a die width of 500 mm. The ear of the film-forming film was stable at 300 m / min. The neck-in amount at that time was 85 mm.

Claims (2)

[1] Melt flow rate (ASTMD 1238, 230 ° C., load 2.16 kg) prepared by using a metallocene catalyst was 20 to 50 g / 10 minutes, [2] Melting point was 155 ° C. or higher, and [3] ¹³ C -99 to 80% by weight of a polypropylene resin (A) having a sum of 2,1-bond amount and 1,3-bond amount measured by NMR of 0.05 mol% or less, and high-pressure polyethylene (B) 1-20 A polypropylene resin composition for extrusion coating, comprising: wt%. 2. The polypropylene resin composition for extrusion coating according to claim 1, wherein the polypropylene resin (A) has a Mw / Mn measured by a gel permeation chromatograph (GPC) method in a range of 4.0 or less. object.