JP3578426B2 - Polypropylene film and laminate thereof - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention mainly relates to a polypropylene film and a laminate thereof preferably used as a sealant film or an adhesive film, and more particularly, to a low-temperature heat sealability, excellent blocking resistance and transparency, and a stretched polypropylene film, polyamide The present invention relates to a polypropylene film excellent in adhesiveness to a substrate composed of a film, a polyester film, a polyvinyl chloride film, an aluminum foil or the like, and a laminate thereof.
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
Conventionally, a propylene random copolymer film composed of propylene and another α-olefin, which has been used as a packaging film, is inferior in low-temperature heat sealability, blocking resistance, and transparency after aging.
[0003]
Therefore, for the purpose of improving the low-temperature heat-sealing property of the propylene random copolymer film, studies for increasing the α-olefin content as a comonomer in the propylene random copolymer have been conventionally conducted. However, although the low-temperature heat-sealing property is improved by increasing the α-olefin content, blocking resistance and transparency after aging are deteriorated, and a good film has not been obtained.
[0004]
Further, in order to improve low-temperature heat sealability, blocking resistance, and transparency after aging, improvement of a catalyst used in the preparation of a propylene random copolymer and a process for producing the same have been attempted, but are satisfactory. No propylene random copolymer film was obtained.
[0005]
On the other hand, a linear low-density ethylene copolymer film conventionally used as a packaging film has good low-temperature heat sealability but is inferior in scratch resistance and rigidity.
[0006]
Thus, both the conventional propylene random copolymer film and the linear low-density ethylene copolymer film can satisfy all the properties of low-temperature heat sealability, blocking resistance, and transparency after aging. could not.
[0007]
The present inventors have intensively studied to obtain a propylene random copolymer film excellent in low-temperature heat sealability, blocking resistance and transparency after aging, and have studied propylene and ethylene or α-olefins having 4 to 12 carbon atoms. Obtained by performing a random copolymerization with a metallocene-based olefin polymerization catalyst in the presence of a normal temperature n-decane extraction amount, a melting point and a melt flow rate from a propylene / α-olefin random copolymer having a specific range. The present inventors have found that a desired polypropylene film can be obtained, and have completed the present invention.
[0008]
[Object of the invention]
The present invention is intended to solve the problems associated with the prior art as described above, and is excellent in low-temperature heat sealability, blocking resistance and transparency after aging, and further, a stretched polypropylene film, a polyamide film, and a polyester. It is an object of the present invention to provide a polypropylene film having excellent adhesion to a substrate composed of a film, a polyvinyl chloride film, an aluminum foil or the like, and a laminate thereof.
[0009]
Summary of the Invention
The polypropylene film according to the present invention,
A propylene / α-olefin random copolymer (A) of propylene and ethylene or an α-olefin having 4 to 12 carbon atoms : 100 parts by weight;
Antiblocking agent: 0.01 to 0.5 parts by weight ,
This propylene / α-olefin random copolymer (A)
(I) a copolymer obtained by random copolymerization of propylene with ethylene or an α-olefin having 4 to 12 carbon atoms in the presence of a metallocene-based olefin polymerization catalyst,
( Ii ) normal temperature n-decane extraction amount is 2.5% by weight or less;
( Iii ) the melting point is in the range of 120 to 145 ° C;
( Iv ) The melt flow rate (MFR) is in the range of 0.5 to 15.0 g / 10 minutes.
[0010]
The α-olefin content in the propylene / α-olefin random copolymer (A) is preferably in the range of 1.0 to 10.0 mol%.
The polypropylene film according to the present invention is suitable as a sealant or adhesive film.
[0011]
Further, the polypropylene film laminate according to the present invention,
A polyamide film, a polyester film, a layer selected from a polyvinyl chloride film and an aluminum foil, or a stretched polypropylene film layer as a base material, and the polypropylene film according to the present invention as described above is provided on at least one surface of the base material. It is characterized by being laminated.
[0012]
Note that “film” in the specification of the present application indicates a film or a sheet.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the polypropylene film according to the present invention will be specifically described.
The polypropylene film according to the present invention is formed from a propylene / α-olefin random copolymer (A).
[0014]
Propylene / α - olefin random copolymer (A)
The propylene / α-olefin random copolymer (A) used in the present invention is a copolymer of propylene and ethylene or an α-olefin having 4 to 12 carbon atoms.
[0015]
The comonomer of the propylene / α-olefin random copolymer (A) is ethylene or an α-olefin having 4 to 12 carbon atoms, for example, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene , 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene and the like. These α-olefins (including ethylene) are used alone or in combination of two or more as comonomers.
[0016]
The α-olefin content as described above is preferably 1.0 to 10.0 mol%, more preferably 2.0 to 7.0 mol, based on 100 mol% of the propylene / α-olefin random copolymer. %, Particularly preferably in the range of 3.0 to 5.0 mol%.
[0017]
The propylene / α-olefin random copolymer (A) used in the present invention as described above has the following properties.
(I) Room temperature n-decane extraction amount The room temperature n-decane extraction amount of the propylene / α-olefin random copolymer (A) used in the present invention is 2.5% by weight or less, preferably 2.0% by weight or less, More preferably, it is in the range of 1.5% by weight or less. The use of the propylene / α-olefin random copolymer having a normal-temperature n-decane extraction amount of 2.5% by weight or less makes it possible to obtain a propylene / α-olefin random copolymer excellent in blocking resistance and transparency after aging. A film (polypropylene film) is obtained.
The above normal-temperature n-decane extraction amount was determined by dissolving 5 g of a sample in n-decane 200 CC at 145 ° C. for 1 hour, allowing the sample to stand naturally, and dissolving the propylene-α- It is determined by measuring the amount of the olefin random copolymer.
[0018]
(Ii) Melting point The melting point of the propylene / α-olefin random copolymer (A) used in the present invention is in the range of 120 to 145 ° C, preferably 125 to 140 ° C, more preferably 125 to 135 ° C. When a propylene / α-olefin random copolymer having a melting point in the above range is used, a propylene / α-olefin random copolymer film having excellent low-temperature heat sealability as well as excellent blocking resistance and scratching resistance Is obtained.
The measuring method of the melting point is based on ASTM-D-790.
[0019]
(Iii) Melt flow rate (MFR)
The melt flow rate (MFR) of the propylene / α-olefin random copolymer (A) used in the present invention is 0.5 to 15.0 g / 10 minutes, preferably 3.0 to 10.0 g / 10 minutes, Preferably it is in the range of 5.0 to 8.0 g / 10 minutes. The propylene / α-olefin random copolymer (A) having a melt flow rate in the above-mentioned range has good moldability because melt extrusion is easy and sufficient melt tension is obtained.
The melt flow rate (MFR) is measured according to ASTM-D-1238 (230 ° C., 2.16 kg load).
[0020]
Propylene · alpha - olefin random copolymer of propylene · alpha-olefin random copolymer having the properties as preparation <br/> above (A) (A) uses the olefin polymerization catalyst of the metallocene Can be prepared. With a catalyst other than a metallocene-based olefin polymerization catalyst, for example, a conventionally known Ziegler-based catalyst, it is difficult to prepare a propylene / α-olefin random copolymer (A) having a normal-temperature n-decane extraction amount of 2.5% by weight or less. Can not.
[0021]
Examples of the metallocene olefin polymerization catalyst include (1) a transition metal metallocene compound (a), an organic aluminum oxy compound (b) and / or an ionized ionic compound (c), and if necessary, an organic aluminum compound. A catalyst combining (d) and
(2) a catalyst in which a transition metal metallocene compound (a), an organoaluminum oxy compound (b) and / or an ionized ionic compound (c) are supported on a particulate carrier,
(3) a solid catalyst component comprising a metallocene compound (a) of a transition metal, an organic aluminum oxy compound (b) and / or an ionized ionic compound (c) supported on a particulate carrier, and an organic aluminum compound ( A catalyst comprising d) is used.
[0022]
Such a metallocene-based olefin polymerization catalyst and its catalyst component (including a particulate carrier) are described in detail, for example, in JP-A-6-345809.
[0023]
Examples of the metallocene compound (a) include dimethylsilylene-bis (cyclopentadienyl) zirconium dichloride, rac-dimethylsilylene-bis {1- (4-phenylindenyl)} zirconium dichloride,
rac-dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride.
[0024]
Examples of the organic aluminum oxy compound (b) include methylaluminoxane, ethylaluminoxane, and propylaluminoxane.
[0025]
The ionized ionic compound (c) is a compound that forms an ion pair by reacting with the metallocene compound (a) as described above. Examples of the ionized ionic compound (c) include a Lewis acid and an ionic compound. Compounds. Borane compounds and carborane compounds are used as Lewis acids and ionic compounds.
[0026]
Examples of the Lewis acid used in the present invention include a magnesium-containing Lewis acid, an aluminum-containing Lewis acid, and a boron-containing Lewis acid. Among them, a boron-containing Lewis acid is preferable.
[0027]
Examples of the boron-containing Lewis acid include trifluoroboron, triphenylboron, tris (pentafluorophenyl) boron, and the like. Among them, tris (pentafluorophenyl) boron is particularly preferred.
[0028]
The ionic compound used in the present invention is a salt composed of a cationic compound and an anionic compound, and an ionic compound containing a boron compound as an anion is preferable. Specifically, trialkyl-substituted ammonium salts such as triethylammonium tetra (phenyl) boron, N, N-dialkylanilinium salts such as N, N-dimethylaniliniumtetra (phenyl) boron, di (n-propyl) ammonium Examples thereof include dialkylammonium salts such as tetra (pentafluorophenyl) boron and triarylphosphonium salts such as triphenylphosphoniumtetra (phenyl) boron.
[0029]
Examples of the organoaluminum compound (d) include trialkylaluminums such as trimethylaluminum, alkenylaluminums such as isoprenylaluminum, dialkylaluminum halides such as dimethylaluminum chloride, alkylaluminum sesquihalides such as methylaluminum sesquichloride, and methylaluminum dichloride And alkylaluminum hydrides such as diethylaluminum hydride.
[0030]
The particulate carrier is an inorganic or organic compound, and is a granular or particulate solid having a particle size of 10 to 300 μm, preferably 20 to 200 μm. The propylene / α-olefin random copolymer (A) used in the present invention is, for example, dimethylsilylene-bis (cyclopentadienyl) zirconium dichloride, rac-dimethylsilylene-bis {1- (4-phenylindenyl)} Propylene and ethylene in the presence of a metallocene compound (a) such as zirconium dichloride and an organoaluminum oxy compound (b) such as methylaluminoxane or a Lewis acid (ionized ionic compound (c)) such as trifluoroboron; An α-olefin having 2 to 4 carbon atoms, such as 1-butene, having a α-olefin content of preferably 1.0 to 10.0 mol% in a gas phase, a slurry state, a solution state, or the like. Can be obtained by copolymerizing
[0031]
Polypropylene film The polypropylene film according to the present invention can be prepared from the above-mentioned propylene / α-olefin random copolymer (A) by forming a film using an extruder.
[0032]
Prior to film forming, a resin modifier such as ethylene-propylene copolymer rubber, ethylene-butene copolymer rubber, propylene-butene copolymer rubber, etc., is added to the propylene / α-olefin random copolymer (A). Can be blended within a range that does not impair the purpose of the present invention.
[0033]
In addition, the propylene / α-olefin random copolymer (A) may be mixed with various commonly used additives such as antioxidants, antiblocking agents, ultraviolet absorbers, chlorine absorbers, slip agents, antistatic agents, Compounding agents such as a nucleating agent, a heat stabilizer, an antioxidant, an antifogging agent, a colorant, and a filler can be added within a range that does not impair the object of the present invention.
[0034]
The main ingredients are as follows.
(1) Antioxidant As the antioxidant, a conventionally known phenol-based or phosphorus-based antioxidant, or a combination of these antioxidants can be used.
[0035]
Examples of phenolic antioxidants include octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate and pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-). 4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 1,3,5-tris [ethylene -3- (3,5-Di-t-butyl-4-hydroxyphenyl) propionate] -s-triazine-2,4,6- (1H, 2H, 3H) trione, 1,2,3-tris (2 -Methyl-4-hydroxy-5-t-butylphenol) butane, 4,4-methylenebis (2,6-di-t-butylphenol) hexamethylene glycol- [Β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 6- (4-hydroxy-3,5-di-t-butylanilino) 2,4-bis-octyl-1, 3,5-triazole, 2,2-thio [diethyl-bis-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-methylenebis (4-methyl-6-t -Nonylphenol), 2,6-bis-[(2-hydroxy-3-t-butyl-4-hydroxyphenyl) propionyl-oxyethyl] isocyanurate, 3,5-di-t-butyl-4-hydroxy-toluene and the like Is used.
[0036]
Examples of the phosphorus-based antioxidants include triphenyl phosphite, diphenyl phosphite, didecyl phosphite, tridecyl phosphite, trioctadecyl phosphite, tris (2,4-di-t-butylphenyl) phosphite and tetrakis. (2,4-Dialkylphenyl) -4,4-biphenylenediphosphonite and the like are used.
[0037]
The phenolic antioxidant or the phosphorus antioxidant as described above is preferably 0.01 to 0.5 part by weight, more preferably 100 parts by weight of the propylene / α-olefin random copolymer (A). Is used in a proportion of 0.03 to 0.5 part by weight, particularly preferably 0.05 to 0.2 part by weight. When a phenolic antioxidant and a phosphorous antioxidant are used in combination, the weight ratio of the phenolic antioxidant / phosphorous antioxidant is preferably 70/30 to 30/70, more preferably 60/40 to 40/30. It is desirable to be in the range of 40/60.
[0038]
(2) Anti-blocking agent As the anti-blocking agent, for example, synthetic or natural silica, silicon dioxide, talc, zeolite and the like are used.
The average particle size of these antiblocking agents is preferably 5 μm or less, more preferably 4 μm or less. When the average particle size is in such a range, a polypropylene film having good transparency and scratch resistance can be obtained.
[0039]
The water content of the anti-blocking agent is preferably 15% by weight or less, more preferably 5% by weight or less. It is preferable to use an anti-blocking agent having a water content in the above range since foaming does not occur at the time of forming a polypropylene film.
[0040]
The anti-blocking agent is preferably in a proportion of 0.01 to 0.5 part by weight, more preferably 0.05 to 0.2 part by weight, based on 100 parts by weight of the propylene / α-olefin random copolymer (A). Used in
[0041]
(3) Slip agent As the slip agent, for example, one or a combination of two or more linear monocarboxylic acid monoamide compounds or linear monocarboxylic acid bisamide compounds can be used.
Examples of the linear monocarboxylic acid monoamide compound include oleic amide, stearic amide, erucic amide, palmitic amide, behenic amide, lauric amide and the like.
[0042]
Examples of the linear monocarboxylic acid bisamide compound include ethylene bisoleic acid amide, ethylene bis stearic acid amide, and methylene bis stearic acid amide.
[0043]
From the viewpoint of the film slip property during molding and the film slip property after molding, it is preferable to use a linear monocarboxylic acid monoamide compound alone. In the case of a polypropylene film laminate according to the present invention described below, it is preferable to use a linear monocarboxylic acid monoamide compound and a linear monocarboxylic acid bisamide compound in combination from the viewpoint of slip properties after lamination. .
[0044]
The slip agent as described above is preferably 0.01 to 1.0 part by weight, more preferably 0.03 to 0.5 part by weight, based on 100 parts by weight of the propylene / α-olefin random copolymer (A). Parts, particularly preferably 0.05 to 0.2 parts by weight. When a linear monocarboxylic acid monoamide compound and a linear monocarboxylic acid bisamide compound are used in combination, the weight ratio of linear monocarboxylic acid monoamide compound / linear monocarboxylic acid bisamide compound is preferably Is preferably in the range of 20/80 to 80/20, more preferably 30/70 to 70/30.
[0045]
The polypropylene film according to the present invention can be prepared, for example, by the following film forming method.
Using a single-screw or twin-screw extruder, the propylene / α-olefin random copolymer (A) melted at a temperature of 180 to 280 ° C. is extruded into a film having a thickness of 10 to 1000 μm, and is extruded. The polypropylene film according to the present invention can be obtained by winding the obtained film at a take-up speed of 5 to 200 m / hour. The propylene / α-olefin random copolymer (A) may contain the above-mentioned various additives.
The thickness of the polypropylene film according to the present invention is usually in the range of 5 to 1000 μm, preferably 10 to 300 μm, more preferably 15 to 100 μm.
[0046]
Polypropylene film laminate The polypropylene film laminate according to the present invention is based on a layer selected from a polyamide film, a polyester film, a polyvinyl chloride film and an aluminum foil, or a stretched polypropylene film layer. Is formed by laminating the above-described polypropylene film according to the present invention on at least one surface of the film.
[0047]
Such a polypropylene film laminate according to the present invention, the polypropylene film according to the present invention, by laminating a polypropylene film according to the present invention and the substrate prepared in advance, for example, or by laminating the polypropylene film layer according to the present invention on the substrate. It can be obtained by laminating by an extrusion lamination method.
[0048]
【The invention's effect】
The polypropylene film according to the present invention has less components in the low molecular weight region in the propylene / α-olefin random copolymer (A), and thus has a lower molecular weight component than the conventional propylene / α-olefin random copolymer film. Bleed-out is small. Therefore, the polypropylene film according to the present invention is excellent in anti-blocking property, and even when a higher anti-blocking property is required, the compounding amount of the anti-blocking agent can be significantly reduced, and scratch resistance ( Scratch resistance) and transparency after aging.
[0049]
Moreover, the melting point of the propylene / α-olefin random copolymer (A) is in the range of 120 to 145 ° C, so that the polypropylene film according to the present invention is excellent in blocking resistance and low-temperature heat sealability.
[0050]
Furthermore, the polypropylene film according to the present invention is excellent in adhesion to a plastic film such as a polyamide film, a polyester film, a polyvinyl chloride film, a stretched polypropylene film, or a metal foil such as an aluminum foil.
[0051]
The polypropylene film laminate according to the present invention has excellent adhesion between the above-described substrate and the layer of the polypropylene film according to the present invention, and the polypropylene film layer has a low-temperature heat-sealing property, blocking resistance, and after aging. Excellent transparency.
[0052]
The polypropylene film according to the present invention having the above-described effects is suitable as a sealant or adhesive film, and can be used for applications such as packaging films for foods, clothes, sundries, and the like.
[0053]
Further, the polypropylene film laminate according to the present invention can be used for applications such as packaging films for foods, clothing, sundries and the like.
[0054]
【Example】
Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.
[0055]
[Examples 1 to 5]
After adding each amount of silica (anti-blocking agent, average particle size = 3 μm) to each of the polypropylene resins shown in Examples 1 to 5 of Table 1 prepared using a metallocene-based olefin polymerization catalyst. A T-die film was formed under the following conditions.
[0056]
Model: T-die molding machine with a 65 mm diameter extruder [manufactured by Toshiba Machine Co., Ltd.]
Molding temperature: 230 ° C
Take-off speed: 30m / min Cooling: Chill roll temperature 40 ° C
Film thickness: 25 μm
The transparency, blocking resistance, scratch resistance and heat sealability of the polypropylene film obtained as described above were tested by the following methods.
The results are shown in Table 1.
[0057]
<Test method>
(1) Transparency Based on ASTM-D-1003, the haze (%) of the film at 23 ° C. and the film haze (%) after 3 days at 80 ° C. were determined.
(2) Blocking resistance According to ASTM-D-1893, the blocking force (N / m) after 1 day at 50 ° C. and the blocking force (N / m) after 7 days at 50 ° C. It was measured.
(3) Heat sealability After using a heat sealer, two films are superimposed and heat-sealed at a seal pressure of 0.2 MPa, a seal time of 1 second, and at an interval of 5 ° C., and then a heat seal tensile tester [Co., Ltd.] Made by Toyo Seiki Seisakusho, Ltd.] at 500 mm / min to confirm that the seal portion was completely sealed without peeling off, and the temperature at the time of complete seal was taken as the heat seal temperature (° C.). .
[0058]
(4) Scratch resistance (scratch resistance)
The film was rubbed with both hands, and the scratch resistance of the film surface was evaluated according to the following four-stage scale.
[4-level display]
A: Very good B: Excellent C: Poor D: Very poor
[Comparative Examples 1-4]
Each amount of silica (same as silica used in Examples 1 to 5) was added to each of the polypropylene resins shown in Comparative Examples 1 to 3 in Table 1 prepared using a Ziegler-based olefin polymerization catalyst. After that, a T-die film was formed under the same conditions as in Examples 1 to 5.
[0060]
The same tests as in Examples 1 to 5 were conducted on the transparency, blocking resistance, scratch resistance, and heat sealability of the obtained polypropylene film.
The results are shown in Table 1.
[0061]
[Table 1]

Claims (4)

A propylene / α-olefin random copolymer (A) of propylene and ethylene or an α-olefin having 4 to 12 carbon atoms : 100 parts by weight;
Antiblocking agent: 0.01 to 0.5 parts by weight ,
This propylene / α-olefin random copolymer (A)
(I) a copolymer obtained by random copolymerization of propylene with ethylene or an α-olefin having 4 to 12 carbon atoms in the presence of a metallocene-based olefin polymerization catalyst,
( Ii ) normal temperature n-decane extraction amount is 2.5% by weight or less;
( Iii ) the melting point is in the range of 120 to 145 ° C;
( Iv ) A polypropylene film having a melt flow rate (MFR) in the range of 0.5 to 15.0 g / 10 minutes. The polypropylene film according to claim 1 , wherein the α-olefin content in the propylene / α-olefin random copolymer (A) is in a range of 1.0 to 10.0 mol%. The polypropylene film according to claim 1, which is a film for a sealant or an adhesive. A polyamide film, a polyester film, a layer selected from a polyvinyl chloride film and an aluminum foil, or a stretched polypropylene film layer as a base material, and the polypropylene film according to claim 1 or 2 on at least one surface of the base material. A polypropylene film laminate, which is laminated.