JP3228106B2 - Polypropylene composition for laminated stretched film and laminated stretched film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polypropylene composition for a laminated stretched film and a laminated stretched film having such a composition in a surface layer. More specifically, a laminated stretched film that gives a film having an excellent balance between solvent resistance and hot tack property, and that when formed into a film, has very little hindrance to transparency and low-temperature heat sealability, and is excellent in film forming properties. The present invention relates to a polypropylene composition for use and a laminated stretched film having such a polypropylene composition in a surface layer.

[0002]

2. Description of the Related Art Since polypropylene has excellent physical properties, it has been used in a wide variety of applications, for example, in the field of packaging films. However, since a single-layer polypropylene film has a high heat-sealable temperature and a narrow appropriate temperature range, in order to improve the heat-sealability at a low temperature in this kind of application, the polypropylene film is usually made of ethylene and / or α-. In general, a polypropylene random copolymer obtained by random copolymerization of an olefin is used. In addition, the random copolymer has good randomness of the comonomer, low crystallinity and low melting point, and good transparency and heat sealability. On the other hand, as the content of ethylene and / or α-olefin increases, the There is a disadvantage that the solubility in organic solvents, which are considered unfavorable, for example, a saturated hydrocarbon-based solvent is significantly increased.

As a method for producing such a propylene random copolymer, attempts have recently been made to produce a propylene random copolymer by a so-called gas phase polymerization method in which a solvent or an active monomer liquid is substantially absent. However, for example, in the method described in JP-A-63-276541, the propylene / butene-1 copolymer as the main component is produced by a gas phase polymerization method,
The content of xylene solubles is as high as 15% by weight or more, which deteriorates blocking resistance and bleed whitening property, and is still insufficient as a packaging film. In particular, in the case of film formation using a large-sized processing machine, such a defect is likely to occur. Further, the low-temperature heat seal modifier contains many low molecular weight polymer components which are not preferable for a packaging film. For this reason, although excellent in low-temperature heat-sealing properties, the amount of deposits on the roll during longitudinal roll stretching during long-time film formation increases, and the film-forming property deteriorates.

Further, the method described in Japanese Patent Application Laid-Open No. 61-248740 can improve the low-temperature heat sealability of a composition, but it is difficult to obtain a propylene-ethylene copolymer or propylene-ethylene. The butene-1 copolymer has a high melting point of 140 ° C. or higher because of its low comonomer content, and is still insufficient for exhibiting high hot tack strength. JP-A-56-58861 also describes a film having improved transparency and low-temperature heat sealability. However, a propylene / ethylene copolymer or a propylene / ethylene / butene-1 copolymer as a main component is disclosed. Is
Since the comonomer content is low, it becomes a high melting point copolymer,
Difficulty in hot tack. JP-A-64-18633
The propylene-ethylene copolymer and the propylene-ethylene-butene-1 copolymer, which are also the main components in the publication, are produced by a bulk polymerization method, have a low comonomer content, and provide a favorable hot tack property. Is not enough.

Under such circumstances, the present applicant has already filed a Japanese Patent Application No. Hei 6-92317 as a composition having an excellent balance between low-temperature heat sealing properties and hot tack properties. In addition, the present applicant has filed Japanese Patent Application No. 5-262340 in order to obtain a polypropylene random copolymer composition having an excellent balance between solvent resistance and transparency.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a film which can be formed stably for a long time without impairing transparency and heat sealing properties which are inherently preferable properties of a polypropylene film. An object of the present invention is to provide a polypropylene composition for a laminated stretched film having an excellent balance of properties, and a laminated stretched film having such a composition in a surface layer.

[0007]

The present inventors have made intensive studies to develop such a polypropylene random copolymer composition, and as a result, have found that a crystalline propylene random copolymer having an α-olefin content in a specific range. And a propylene / α-olefin random copolymer having a specific range of α-olefin content and a crystalline propylene homopolymer having a specific range, and find that the above object can be achieved, and complete the present invention. Reached.

That is, the present invention relates to (A) propylene and α-
The propylene content obtained by polymerizing an olefin or propylene with an α-olefin and ethylene is 60 to
97% by weight, 0-6% by weight of ethylene component and 3-40% by weight of α-olefin component,
A crystalline propylene random copolymer 73 to 97 having a xylene-soluble content (hereinafter referred to as CXS) of 25% by weight or less.
% By weight, a propylene component content obtained by copolymerizing (B) propylene and an α-olefin is 35 to 75% by weight, and an α-olefin component content is 25 to 65% by weight.
Propylene · α having a CXS of 30% by weight or more
-2.5 to 17% by weight of an olefin random copolymer;
Further, (C) 0.5 to 1 crystalline propylene homopolymer
The present invention relates to a polypropylene composition for a laminated stretched film, which is a composition containing 0% by weight. The present invention also relates to a laminated film having the above composition in a surface layer.

According to the present invention, a crystalline propylene random copolymer having an .alpha.-olefin content sufficient to exhibit high hot tack strength and a propylene .alpha.-olefin having a low molecular weight and an improved low-temperature heat sealability. A composition comprising a random copolymer and a crystalline propylene homopolymer that improves solvent resistance and hot tack properties, and by laminating such a composition on one or both sides of a crystalline polypropylene film, a long-term stable film formation. It has become possible to obtain a film having excellent hot tack properties and solvent resistance without impairing the properties, transparency and heat sealing properties.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The crystalline propylene random copolymer (A) used in the polypropylene composition of the present invention includes propylene and α-
Propylene content of 60 to 97 obtained by copolymerizing olefin or propylene with α-olefin and ethylene
% By weight of a random copolymer.

[0011] The α-olefin may have 4 to 10 carbon atoms.
Α-olefins such as butene-1, pentene-1,
Hexene-1, heptene-1, octene-1,3-methylpentene-1 and the like can be mentioned. Of these, butene-1 is preferably used.

Crystalline propylene random copolymer (A)
Propylene component, ethylene component, and α-
The content of the olefin component is such that the propylene component content is 60 to 97% by weight, preferably 65 to 92% by weight, the ethylene component content is 0 to 6% by weight, preferably 0 to 5% by weight, and the α-olefin component content is Is 3 to 40% by weight
Preferably it is 3-35% by weight.

If the propylene component content is less than 60% by weight, the melting point is too low to deteriorate the film-forming properties, and if it exceeds 97% by weight, the melting point is so high that the low-temperature heat sealability is insufficient. The ethylene component is not an essential component, but is preferably contained up to about 6% by weight in view of long-term film-forming properties and hot tack strength. Further, the content of the α-olefin component is preferably 3 to 40% by weight, and the content is 3% by weight.
If it is lower than this, the melting point is high and hot tack strength is not developed,
If the content exceeds 40% by weight, the film-forming properties of the film deteriorate. In addition, in the copolymer of propylene and α-olefin containing no ethylene, the content of α-olefin is preferably 15% by weight or more. CXS of the crystalline propylene random copolymer (A) is 25% by weight or less, preferably 1 to 20% by weight, more preferably 1 to 15% by weight. If the CXS of the crystalline propylene random copolymer (A) exceeds the above limit, the hot tack property, the blocking resistance, and the film forming property are adversely affected.

Crystalline propylene random copolymer (A)
A compound obtained by decomposing a random copolymer obtained by copolymerizing propylene and an α-olefin with heat or peroxide to have Mw / Mn of 5.5 or less can also be preferably used.

Crystalline propylene random copolymer (A)
Is generally [η] = 0.3 to 6.0 dl / g, preferably [η] = 0.8 to 5.0 dl / g,
[Η] = 1.0 to 3.0 dl / g is more preferable.

Crystalline propylene random copolymer (A)
Can generally be produced by copolymerizing propylene and an α-olefin using a Ziegler-Natta catalyst, but in some cases, a soluble catalyst such as a metallocene can also be used.

Preferred catalyst systems include Ziegler-Natta catalyst systems which essentially contain at least titanium, magnesium, halogen and an electron donor, such as (a) a solid catalyst component which essentially contains titanium, magnesium, halogen and an electron donor. (b) an organometallic compound (c) general formula ^{R 1 R 2 Si (OR 3} ) 2 (R 1 is an alicyclic hydrocarbon group having 5 to 20 carbon atoms, R ^2, R ³ is 1 to carbon atoms And a catalyst system comprising a silicon compound represented by the following formula: The solid catalyst component (a) in the above catalyst system contains titanium, magnesium, and halogen as essential components. In general, a solid product obtained by reducing a titanium compound with an organic magnesium compound is treated with an ester compound, and then treated with an ester compound. Obtained by treatment with titanium chloride.

The titanium compound has the general formula Ti (OR) _b X
_4-b (R represents a hydrocarbon group having 1 to 20 carbon atoms, X represents a halogen atom, and b represents a number satisfying 0 <b ≦ 4).
Specific examples of R include alkyl groups such as methyl, ethyl, iso-propyl, butyl, iso-butyl, amyl, iso-amyl, hexyl, heptyl, octyl, decyl, dodecyl, phenyl, cresyl, xylyl, naphthyl and the like. Examples thereof include an aryl group, a cycloalkyl group such as cyclohexyl and cyclopentyl, an allyl group such as propenyl, and an aralkyl group such as a benzyl group.

As the magnesium component, any type of organomagnesium compound containing a magnesium-carbon bond can be used. Especially the general formula RMgX
(Wherein, R represents a hydrocarbon group having 1 to 20 carbon atoms, and X represents a halogen), and a general formula RR′Mg (where R and R ′ represent 1 to 20 carbon atoms). ~ 20
Represents a hydrocarbon group. Here, R and R 'may be the same or different. ) Is preferably used.

As the Grignard compound, methyl magnesium chloride, ethyl magnesium chloride, ethyl magnesium bromide, ethyl magnesium iodide, propyl magnesium chloride, propyl magnesium bromide, butyl magnesium chloride, butyl magnesium bromide, sec-butyl magnesium chloride, sec-butyl magnesium Bromide, tert
-Butylmagnesium chloride, tert-butylmagnesium bromide, amylmagnesium chloride, is
o-Amylmagnesium chloride, phenylmagnesium chloride, phenylmagnesium bromide, etc.
As magnesium compounds represented by R′Mg, diethyl magnesium, dipropyl magnesium, di-iso-
Propyl magnesium, dibutyl magnesium, di-s
ec-butyl magnesium, di-tert-butyl magnesium, butyl-sec-butyl magnesium, diamyl magnesium, diphenyl magnesium and the like.

The organoaluminum compound (b) used in combination with the solid catalyst component (a) has at least one Al-carbon bond in the molecule. Specific examples of such organoaluminum compounds include triethylaluminum, triisobutylaluminum, trialkylaluminum such as trihexylaluminum, diethylaluminum halide, dialkylaluminum halide such as diisobutylaluminum halide, a mixture of trialkylaluminum and dialkylaluminum halide, and tetraethylaluminum. Examples thereof include alkylalumoxane such as dialumoxane and tetrabutyldialumoxane.
Among these organoaluminum compounds, trialkylaluminum, a mixture of trialkylaluminum and dialkylaluminum halide, and alkyl alumoxane are preferable, and especially triethylaluminum, triisobutylaluminum, a mixture of triethylaluminum and diethylaluminum chloride and tetraethyldialumoxane are preferable. preferable. Further, the organoaluminum compound may be used in combination with a boron compound such as trityltetra (pentafluorophenyl) borate or N, N′-dimethylaniliniumtetra (pentafluorophenyl) borate. The amount of the organoaluminum compound used is from 1 to 1 per mole of titanium atom in the solid catalyst.
Although it can be selected from a wide range such as 000 mol, a range of 5 to 600 mol is particularly preferable.

The general formula of the electron donor R ¹ R ² Si (O
Examples of the silicon compound (c) represented by R ³ ) ₂ include cyclohexylethyldimethoxysilane, cyclohexylpropyldimethoxysilane, cyclohexyliso-propyldimethoxysilane, cyclohexylbutyldimethoxysilane, cyclohexyliso-butyldimethoxysilane, and cyclohexyltert-butyldimethoxysilane. , Cyclohexylpentyldimethoxysilane, cyclohexylhexyldimethoxysilane, cyclohexylethyldiethoxysilane, cyclohexylpropyldiethoxysilane, cyclohexyliso-propyldiethoxysilane, cyclohexylbutyldiethoxysilane, and the like.

The catalyst system comprises Al atoms in component (b) /
The molar ratio of Ti atoms in component (a) is 1 to 1000, preferably 5 to 600, and the molar ratio of Al atoms in component (c) / component (b) is 0.02 to 500, preferably 0.05. ~
The polymerization temperature is 20 to 150 ° C., preferably 50 to 95 ° C., and the polymerization pressure is atmospheric pressure to 40 Kg /
Under the condition of cm ² G, hydrogen is supplied for controlling the molecular weight, and propylene and α-olefin are polymerized.

Next, the propylene / α-olefin random copolymer (B), which is another component constituting the polypropylene composition of the present invention, is obtained by polymerizing propylene and α-olefin. -The propylene content in the olefin random copolymer (B) is 35 to 7;
A propylene / α-olefin random copolymer having 5% by weight and an α-olefin component content of 25 to 65% by weight.

The content of the propylene component in the propylene / α-olefin random copolymer (B) is 35 to 75% by weight, preferably 40 to 70% by weight. The content of α-olefin component is 25 to 65% by weight, preferably 30 to 60%.
% By weight. If the propylene component content is less than 35% by weight, the hot tack strength is poor, and if it exceeds 75% by weight, the low-temperature heat sealability is poor.

As the α-olefin of the α-olefin component constituting the propylene / α-olefin random copolymer (B), those used for the crystalline propylene random copolymer (A) can be similarly used. That is, α-olefins having 4 to 10 carbon atoms, for example, butene-1, pentene-1, hexene-1, heptene-1, octene-1,3-methylpentene-1 and the like, among which butene-1 is preferably used. . Further, a small amount of ethylene can be contained within a range not to impair the object of the present invention. The CXS of the propylene / α-olefin random copolymer (B) is at least 30% by weight, preferably at least 50% by weight, more preferably at least 70% by weight. If the CXS of the propylene / α-olefin random copolymer (B) is below the limit, the low-temperature heat sealability is adversely affected.

As the catalyst for producing the propylene / α-olefin random copolymer (B) of the present invention, those used for the crystalline propylene random copolymer (A) can be used in the same manner. It is more preferred to use a Ziegler-Natta catalyst containing a solid catalyst component which essentially comprises a halogen and an electron donor. Examples of such a polymerization catalyst include (a) a solid catalyst component essentially containing titanium, magnesium, halogen and an electron donor used when producing the crystalline propylene random copolymer (A). A solid catalyst component, (b) an organometallic compound, and (c) a general formula R ¹ R ² Si (OR ³ ) ₂ (R ¹ is an alicyclic hydrocarbon group having 5 to 20 carbon atoms, and R ² and R ³ are Which represents a hydrocarbon group having 1 to 20 carbon atoms).

The production of the copolymer (B) can be carried out in either a liquid phase or a gaseous phase, but it is particularly preferable to carry out the production under the conditions in which the copolymer dissolves in the liquid phase, that is, in the presence of a solvent. preferable. When performed in the liquid phase, an inert solvent such as hexane, heptane, an aliphatic hydrocarbon such as kerosene, an alicyclic hydrocarbon such as cyclohexane, benzene, toluene,
A so-called solvent method of polymerizing in an aromatic hydrocarbon such as xylene can be used. Alternatively, a so-called bulk method using the olefin itself as a reaction medium can be employed. Among these, it is most preferable to carry out in the presence of a solvent.
The copolymer of the present invention can be carried out in the same manner as a polymerization reaction of an olefin using a usual Ziegler-type catalyst. The temperature of the copolymer is usually selected in the range of 30 to 140 ° C, preferably 50 to 120 ° C. The polymerization is preferably carried out under pressure, usually from normal pressure to 50 kg / c.
It is preferable to carry out under a pressure of about m ² . The molecular weight can be adjusted to some extent by changing the polymerization conditions such as the polymerization temperature and the use ratio of the catalyst component, but the most effective method is to add hydrogen into the polymerization system.

The crystalline propylene homopolymer (C) in the polypropylene random copolymer composition of the present invention is usually a crystalline propylene homopolymer obtained by homopolymerizing propylene with a Ziegler-Natta catalyst. A polymer is used. However, in some cases a small amount of α
-An olefin (ethylene, butene-1, etc.) may be copolymerized. The crystalline propylene homopolymer (C) has a melting point measured by DSC of preferably 150 ° C. or higher, more preferably 155 ° C. or higher.

The boiling n-heptane insoluble content in the polypropylene composition of the present invention is usually determined by a crystalline melting peak derived from the crystalline propylene homopolymer (C) in a DSC curve obtained by differential scanning calorimetry. Is 152-
Detected at 168 ° C. The melting peak varies in the amount of heat of fusion depending on the amount of the crystalline propylene homopolymer (C). If this peak is not detected, both of the conflicting properties such as solvent resistance and hot tack property are satisfied. It is difficult to become a polypropylene random copolymer composition.

The polypropylene random copolymer composition of the present invention has a propylene component content of 60 to 97% by weight obtained by polymerizing propylene and an α-olefin or propylene, an α-olefin and ethylene, and an ethylene component content. Is 0 to 6% by weight and α-olefin component content is 3 to 40% by weight, and CXS is 25% by weight or less, and a crystalline propylene random copolymer (A) is polymerized with propylene and an α-olefin. A propylene / α-olefin random copolymer (B) having a propylene component content of 35 to 75% by weight, an α-olefin component content of 25 to 65% by weight, and a CXS of 30% by weight or more, and a crystal. The crystalline propylene homopolymer (C) is composed of the crystalline propylene homopolymer (C) and the crystalline propylene random copolymer. Coalescence (A) and the propylene · α
A blend of an olefin random copolymer (B), or a copolymer of propylene and an α-olefin or propylene with an α-olefin and ethylene after prepolymerization with propylene alone. Good.

Composition of the crystalline propylene random copolymer (A), the propylene / α-olefin random copolymer (B) and the crystalline propylene homopolymer (C) in the polypropylene random copolymer composition of the present invention The ratio of the crystalline propylene random copolymer (A) is 73 to 97% by weight, preferably 80 to 95.5% by weight, and more preferably 85 to 94.5% by weight. 2.5 to 17% by weight of a propylene / α-olefin random copolymer (B),
Preferably 4 to 15% by weight, more preferably 5 to 10% by weight.
% By weight. The content of the crystalline propylene homopolymer (C) is 0.5 to 10% by weight, preferably 0.5 to 5% by weight, and more preferably 0.5 to 2.7% by weight.

Crystalline propylene random copolymer (A)
If the content is less than 73% by weight, the hot tack property is poor, and if it exceeds 97% by weight, the heat sealing property is insufficient.
If the propylene / α-olefin random copolymer (B) is less than 2.5% by weight, the effect of improving hot tack in the low temperature range is not recognized, and if it exceeds 17% by weight, the heat sealability is improved. However, the hot tack strength of the entire seal area is deteriorated. On the other hand, if the content of the crystalline propylene homopolymer (C) is less than 0.5% by weight, the solvent resistance is insufficient, and if it is more than 10% by weight, the transparency is deteriorated and the hot tack strength is poor. Is not preferred.

Further, as the composition, those having a xylene-soluble content of 20% by weight or less at 20 ° C. are preferably used. Outside of these ranges, a polypropylene composition having good film-forming properties without impairing the transparency and heat-sealing properties, which is the object of the present invention, and having excellent solvent resistance and hot tack properties is obtained. Hateful.

The polypropylene composition has a melt flow rate of 1 to 50 g / 10 minutes, preferably 2 to 30 g / 1.
It is preferably 0 minutes, more preferably 3 to 20 g / 10 minutes, from the viewpoint of transparency and high-speed processability in film formation. Further, the polypropylene composition is soft, and the intrinsic viscosity thereof is preferably in the range of 1 to 3 dl / g as measured at 135 ° C. in tetralin.

The random copolymer composition of the present invention is blended with an antioxidant, a neutralizing agent, a lubricant, an antiblocking agent, an antistatic agent, and the like, if necessary, as long as the present invention is not impaired. be able to.

Next, the laminated stretched film of the present invention will be described. The stretched film having the polypropylene composition of the present invention in the surface layer can stably form a film for a long time without impairing transparency and heat sealing properties, which are inherently preferable properties of the polypropylene film, and has solvent resistance and hot A stretched film having an excellent balance of tackiness and having a surface layer laminated on one or both sides of a film as a substrate can be obtained.

The laminated stretched film of the present invention can be obtained by laminating the above-mentioned polypropylene composition on one side or both sides of a substrate film by a known method. As the substrate, for example, a crystalline α-olefin polymer is used, and in particular, crystalline polypropylene is preferably used. Crystalline polypropylene generally contains at least 80% of a boiling heptane-insoluble portion, has an intrinsic viscosity ([η]) of 1.3 to 4.2 dl / g, and has a propylene component of 95% or more in the polymer. Can be suitably used. Further, the crystalline polypropylene may be a copolymer containing 5% or less of ethylene and / or butene-1 component.

The laminated stretched film of the present invention can be obtained, for example, by the following method. That is, a method of passing the base material layer and the polypropylene composition together between pressure rollers using a pre-formed sheet, applying the polypropylene composition on the base material layer as a solution or dispersion of a solvent such as toluene. A method of laminating, a method of laminating the above-mentioned polypropylene composition by melt extrusion coating on a substrate layer,
Alternatively, the laminated stretched film of the present invention can be obtained by a method in which the polypropylene composition and the base polymer are extruded by separate extruders, and the two are still joined in a molten state at a common die or at an exit.

Although the laminated film of the present invention can be used as it is, it is preferable to uniaxially or biaxially stretch the laminated film after laminating the above polypropylene composition. Such a stretched laminated film is manufactured by the following known method. That is,
1. 1. In an extrusion die for forming a sheet or in the vicinity of an outlet, a raw laminated sheet is produced by so-called co-pressing in which the two are combined in a molten state, and then biaxially stretched. 2. a method in which the above-mentioned polypropylene composition is extrusion-laminated on a sheet of a base material, and then biaxially stretched; A method in which a sheet of a base material is previously uniaxially stretched in the MD direction with a roll group including a metal roll in a heated state, and the polypropylene composition is subjected to extrusion lamination on this sheet, and then stretched in the TD direction. Among them, mainly 3 Is generally used.

The laminated stretched film produced as described above can be formed stably for a long time without impairing transparency and low-temperature heat sealability, and has an excellent balance between solvent resistance and hot tack. It is of great practical value.

Hereinafter, the present invention will be described specifically with reference to Examples, but the scope of the present invention is not limited to Examples.

The measured values of each item in the detailed description of the invention and the examples were measured by the following methods. (1) Butene content; determined by ¹³ C-nuclear magnetic resonance spectroscopy. (2) Ethylene content (% by weight); I was determined by the method described in “(i) Random copolymer” on page 256 of Polymer Analysis Handbook (1985, published by Asakura Shoten).
Determined by the R spectrum method. (3) Melt flow rate (MFR); JIS K7
According to No. 210, the measurement was carried out by the method of condition-14. (4) Transparency (haze): Measured according to JIS K 7105. (5) Boiling n-heptane insolubles; JIS K 6758
A sheet having a thickness of 1 mm obtained by molding according to
Each sample is put into a cylindrical glass filter as a strip sample of × 1 mm × 1 mm, and extracted by a Soxhlet extractor for 14 hours. In this case, the reflux frequency is set to about once / 5 minutes. The weight% of the insoluble matter was determined by weighing the insoluble matter after drying. (6) Melting point (Tm); Using a differential scanning calorimeter (manufactured by PerkinElmer, DSC), 10 mg of a test piece was previously melted at 220 ° C. for 5 minutes in a nitrogen atmosphere, and then at a temperature lowering rate of 5 ° C./min. The temperature was lowered to 40 ° C. for crystallization. Thereafter, the temperature was raised at 10 ° C./min, and the temperature of the maximum peak of the obtained melting endothermic curve was defined as the melting point. In addition, indium (I) measured at a heating rate of 10 ° C./min using this measuring instrument.
The melting point of n) was 156.6 ° C. (7) Low-temperature heat-sealing property (heat-sealing temperature ° C); 2 kg / c with a heat sealer (manufactured by Toyo Seiki Co., Ltd.) heated to a predetermined temperature by superposing the sealant surfaces of the films together.
Crimp 2 seconds under a load of m ² G for heat sealed. After leaving overnight, at 23 ° C, peeling speed 200mm / min, peeling angle 1
Peeling resistance when peeled at 80 degrees is 300g / 25mm
Was determined as the heat sealing temperature. (8) Hot tack property (g / 75 mm): A sealant surface of a film having a width of 75 mm is superposed on each other, and heated with a heat sealer (manufactured by Tester Sangyo) at a predetermined temperature for 2 k.
g / cm ² heat-sealed and crimped 2 seconds under a load of G.
Then, immediately after the load was removed, a peeling force was applied to the seal portion with a plate-like spring, and the peel length was １ ／ inch (3.2 m).
m) was determined. (9) 20 ° C. xylene solubles (CXS) (% by weight); After completely dissolving 1 g of a sample in 100 ml of boiling xylene, the temperature is lowered to 20 ° C. and left for 4 hours. Thereafter, this was separated by filtration into a precipitate and a solution, and the filtrate was dried to 70 ° C. under reduced pressure.
And dried. The weight was measured to determine the weight%. (10) Weight average molecular weight / number average molecular weight (Mw / M
n); gel permeation chromatography (GP
C) was measured under the following conditions. The calibration curve was prepared using standard polystyrene. Model Millipore Waters 150CV type column Shodex M / S 80 Measurement temperature 145 ° C, solvent ortho-dichlorobenzene, sample concentration 5mg / 8ml Note that the conditions of NBS (National Bureau of Standards)
Standards ReferenceMeterial 706 (Mw / Mn =
As a result, the molecular weight distribution (Mw / Mn) of 2.1 was obtained. (11) Film-forming properties: Good separation of the roll between the longitudinal stretching roll and the film during film formation, and almost no dirt on the roll observed with the naked eye, good roll separation and slight dirt on the roll The thing was marked as △.

Reference Example 1 (a) Synthesis of organomagnesium compound A 1-liter flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer was replaced with argon, and then 32.0 g of milled magnesium for Grignard was charged. did. 120 g of butyl chloride and 500 parts of dibutyl ether are added to the dropping funnel.
and add about 30 ml to the magnesium in the flask.
The reaction was started dropwise. After the start of the reaction, the dropwise addition was continued at 50 ° C. for 4 hours, and after the completion of the dropwise addition, the reaction was further continued at 60 ° C. for 1 hour. Thereafter, the reaction solution was cooled to room temperature, and the solid content was separated by filtration. Butylmagnesium chloride in dibutyl ether was hydrolyzed with 1N sulfuric acid, and the concentration was determined by back titration with 1N aqueous sodium hydroxide using phenolphthalein as an indicator.
It was 1 mol / L. (B) Synthesis of solid product After a 500 ml flask equipped with a stirrer and a dropping funnel was replaced with argon, 240 ml of hexane, 5.4 g (15.8 mmol) of tetrabutoxytitanium and 61.4 g (295 mmol) of tetraethoxysilane were used. Was added to obtain a homogeneous solution. Next, 150 ml of the organomagnesium compound synthesized in (a) was heated at 5 ° C.
, The solution was gradually dropped from the dropping funnel over 4 hours. After completion of the dropwise addition, the mixture was further stirred at room temperature for 1 hour, then subjected to solid-liquid separation at room temperature, washed repeatedly with 240 ml of hexane three times, and dried under reduced pressure to obtain 45.0 g of a brown solid product. 1.7% by weight of titanium atoms, 33.8% by weight of ethoxy groups and 2.9% by weight of butoxy groups in the solid product
It was contained. Further, in the wide-angle X-ray diffraction diagram of this solid product by Cu-Ka line, no clear diffraction peak was observed at all, and the solid product had an amorphous structure. (C) Synthesis of ester-treated solid After replacing a 100 ml flask with argon, (b)
6.5 g of solid product synthesized in 16.2 m of toluene
l, and 4.3 ml of diisobutyl phthalate (16 mmol
l) was added, and the mixture was reacted at 95 ° C for 1 hour. (D) Synthesis of solid catalyst (activation treatment) After washing in the above (c), toluene.
2 ml, 0.36 ml of diisobutyl phthalate (1.3 m
mol), 2.2 ml (13 mmol) of butyl ether
And 38.0 ml (346 mmol) of titanium tetrachloride were added thereto and reacted at 95 ° C. for 3 hours. After the reaction, 9
After solid-liquid separation at 5 ° C, 2
Washing was performed twice. The above-mentioned treatment with a mixture of diisobutyl phthalate, butyl ether and titanium tetrachloride was repeated once more under the same conditions, and
After washing twice, 5.0 g of an ocher solid catalyst was obtained. The solid catalyst contained 2.4% by weight of titanium atoms, 18.4% by weight of magnesium atoms, and 16.8% by weight of phthalic acid esters. (E) Preparation method of propylene prepolymerization catalyst In a 220 L reactor in which the inside of the system was sufficiently purged with nitrogen, butane 97.9 L, 400 g of an ocher solid catalyst obtained in the same manner as in Reference Example (d), and triethylaluminum ( The following TE
Abbreviated as A. ) 2.6 mol and 0.384 mol of phenyltrimethoxysilane were added, and the propylene monomer was reacted at 16 ° C for 4.7 hours.
By removing the solvent and drying at 60 ° C. for 3 hours, the prepolymerization ratio (PP / cat.) = 99 g−PP / cat.
Was obtained. A part thereof was demineralized and kneaded in a roll. The melting point (Tm) by DSC was 165 ° C. by DSC.

Production of Crystalline Propylene Random Copolymer (A-1) Propylene and butene-1 were copolymerized using a fluidized bed reactor equipped with a stirrer having an internal volume of 1000 L. First,
Circulating nitrogen gas was supplied to the reactor at a flow rate of 140 m ³ / hr from the lower part of the reactor, and then 60 kg of propylene / butene-1 copolymer particles were supplied for dispersing the catalyst which had been dried and replaced beforehand, and the polymer particles were kept in a fluid state. Kept. The pressure was increased to 12.5 kg / cm ² · G with propylene, the prepolymerization catalyst was 142.8 g / hr, and the TEA was 39.2 mmol.
l / hr, 2.95 mmol / hr of cyclohexylethyldimethoxysilane (hereinafter abbreviated as CHEDMS) was supplied to the reactor, and then hydrogen and propylene were added so that the hydrogen concentration was 0.14 mol% and butene-1 was 21.9 mol%. , Butene-1, and the temperature of the fluidized bed was adjusted to 65 ° C. to initiate polymerization. While keeping the polymer particles at 60 kg, the polymer particles were sequentially taken out into a silo by differential pressure, and after monomer separation, 0.0075 L / Kg of methanol was added.
Irganox 1076 was supplied at 0.0016 g / Kg and treated with hot nitrogen at 60 ° C. for 2 hours.
Then, the mixture was further dried with hot nitrogen at 60 ° C. for 1.5 hours to obtain a white powdery polymer at 10.6 kg / hr.
This polymer had an intrinsic viscosity [η] of 2.76 dl / measured in a tetralin solvent at Mw / Mn = 3.3, 135 ° C.
g, butene content of the copolymer measured by ¹³ C-NMR was 22.4% by weight, and CXS = 7.9% by weight.

Reference Example 2 (a) Preparation method of propylene polymerization catalyst 150 L of sufficiently purified hexane was added to a 250 L reactor equipped with a stirrer, and the system was sufficiently purged with nitrogen.
51.8 g of EA 3.2 mol, CHEDMS 0.32 mol and the solid catalyst obtained in Reference Example (d) are added in terms of titanium atoms. While maintaining 25 ° C., 2.8 kg of propylene was continuously added over 2 hours.

The crystalline propylene random copolymer (A-
2) Production A polymerization temperature of 80 ° C.
Joint pressure 18Kg / cm ^TwoG, average residence time is 6 hours
The catalyst component adjusted in Reference Example 2 (a) was supplied as
Sometimes CHEDMS 5 mmol / hr (TEA / CHED
(MS = 10/1 molar ratio) while supplying water in the polymerization layer.
Propylene and ethylene with an elemental concentration of 0.22%
Gas phase polymerization was performed by continuously supplying butene-1. Get
The copolymer obtained had an ethylene content of 4.4% by weight, butene
One content was 4.1% by weight. Also, MFR = 2.
1, CXS = 6.8% by weight, Mw / Mn = 2.9
Was.

REFERENCE EXAMPLE 3 (a) Preparation method of propylene prepolymerization catalyst 100 ml of sufficiently purified hexane was added to a 500 ml reactor equipped with a stirrer, and the system was sufficiently purged with nitrogen beforehand. Then, 1.24 mmol of TEA and CHEDMS were added.
0.124 mmol of the solid catalyst obtained in Reference Example 1 (d) (see Synthesis Example) was converted to titanium
Add 1 g. By continuously adding propylene while maintaining the temperature at 20 ° C. or lower, and adjusting the amount of absorption, a propylene prepolymerization catalyst of polypropylene / solid catalyst = 2.4 (weight ratio) was obtained.

Production of propylene / α-olefin random copolymer (B) A propylene / butene-1 copolymer was produced by a continuous process using the solid catalyst obtained by preparing the propylene prepolymerization catalyst of Reference Example 2. did. The polymerization reaction has an internal volume of 100
The reaction was continuously carried out in a liquid-filled state with a reaction layer having a liter of warm water jacket and a stirrer. Regarding the supply of the prepolymerized catalyst to the reaction layer, 150 liters of n-hexane and 27.5 g of TEA for protecting the catalyst were first prepared in a prepared layer with a stirrer having an internal volume of 250 liters.
5g and 27.5g of TEA were added at the same time, followed by stirring and circulation.
The suspension was continuously supplied to the reaction layer at 15 L / hr. For the supply of the cocatalyst to the reaction layer, the internal volume was 80 L
Was diluted with n-hexane, and 0.035 kg / hr as TEA was continuously supplied to the reaction layer. Regarding the supply of monomer to the reaction layer,
First, propylene 3.6 was added to the preparation layer with an internal volume of 300 liters.
Kg / hr and 12.9 kg / hr of 1-butene were continuously supplied, and at the same time, n-hexane was also supplied such that the preparation layer maintained a constant level. The pressure of this monomer solution is increased from the preparation layer by a pump and cooled to about -5 ° C.
It was continuously supplied to the reaction layer at 4 kg / hr. Hydrogen was used as a molecular weight regulator, and was continuously joined to the monomer solution line before being supplied to the reaction layer. The temperature of the reaction layer was kept at 40 ° C. by adjusting the cooling temperature of the monomer solution and the temperature of the hot water jacket. Regarding the pressure of the reaction layer, 1
It was adjusted to keep 5 kg / cm ² . (The polymer concentration in the reaction tank was 3.1%.) A small amount of methanol was added to the polymer solution extracted from the reaction tank to stop the polymerization reaction, and unreacted monomers were removed by depressurization. . After further washing with alkaline water, the solvent was removed by steam in a large amount of water to remove the copolymer to 2 kg /
hr. Drying was performed with a vacuum dryer equipped with a heating device. The butene content of the copolymer measured by ¹³ C-NMR was 57.9% by weight, and the intrinsic viscosity measured with a tetralin solvent at 135 ° C. was 1.6 dl / g. MFR =
5.6, and Mw / Mn = 3.6.

Example 1 0.15% by weight of calcium stearate, 0.1% by weight of Sumilizer BHT, Irganox 1010 0.05 were added to the crystalline propylene random copolymer (A-1) obtained in Reference Example 1. % By weight, 2,5-dimethyl 2,
5 After adding di (tert-butylperoxy) hexane and mixing with a Henschel mixer, the mixture was granulated and pelletized while decomposing peroxide with a 40 mmφ extruder. The MFR of the obtained pellet was 6.7. 94% by weight of the obtained pellets and the propylene
5% by weight of an α-olefin random copolymer (B) and 1% by weight of a homopolypropylene (intrinsic viscosity = 1.83 dl / g, MFR = 5.1) as a crystalline homopolymer (C) were mixed with a Henschel mixer. Similarly, the mixture was granulated and pelletized with a 40 mmφ extruder to obtain a polypropylene random copolymer composition shown in Table 1. Next, as a base material layer, Sumitomo Noblen FS2011D (Sumitomo Chemical MFR = 2.5
g / 10 minutes) and using the above-mentioned pellets as a heat-seal layer on the surface, a two- or three-layer laminated stretched film was obtained with a tenter-type stretching machine. The base material layer of this film was melt-extruded at a resin temperature of 257 ° C., and the heat seal layer was melt-extruded at a resin temperature of 222 ° C. and rapidly cooled by a cooling roll at 30 ° C. to obtain a thickness of 0.9 mm. After cooling and solidifying into a sheet, and preheating, the film is stretched 5 times in the longitudinal direction at a stretching temperature of 120 ° C. by the difference in roll peripheral speed of the longitudinal stretching machine, and subsequently stretched 8 times in the transverse direction at a stretching temperature of 157 ° C.
Heat treatment was carried out at 165 ° C., and a two or three layer laminated stretched film having a sealant thickness of 1 μm and a base material of 20 μm was obtained without a film formation defect due to adhesion to a roll even for a long time. Table 2 shows the film forming properties, heat sealing temperature, hot tack strength, and transparency (haze) of the obtained film.

Example 2 Evaluation was carried out in the same manner as in Example 1 except that the mixing ratio between the crystalline propylene random copolymer (A-1) and the propylene / α-olefin random copolymer (B) was changed. ,
A polypropylene random copolymer composition shown in Table 1 was obtained. Table 2 shows the evaluation results.

Example 3 To the crystalline propylene random copolymer (A-2) obtained in Reference Example 2, 0.1% by weight of calcium stearate, 0.2% by weight of Sumilizer BHT, and Irganox 1010 0.05 % By weight, 2,5-dimethyl 2,5
After adding di (tert-butylperoxy) hexane and mixing with a Henschel mixer, the mixture was granulated and pelletized while decomposing peroxide with a 40 mmφ extruder. The MFR of the obtained pellet was 5.9. 84% by weight of the obtained pellets and propylene / α used in Example 1
-15% by weight of an olefin random copolymer (B) and 1% by weight of a crystalline propylene homopolymer (C) were added, mixed with a Henschel mixer, similarly granulated and pelletized with a 40 mmφ extruder, and the polypropylene shown in Table 1 A random copolymer composition was obtained. Table 2 shows the evaluation results.

Comparative Example 1 The crystalline propylene random copolymer (A-1) was evaluated alone, and the evaluation results are shown in Table 2.

Comparative Example 2 The crystalline propylene random copolymer (A-1) obtained in Reference Example 1 and the propylene / α-olefin random copolymer (B) obtained in Reference Example 3 were used. Evaluation was performed in the same manner as in Example 1 except that the mixing ratio was changed, and a polypropylene random copolymer composition shown in Table 1 was obtained. Table 2 shows the evaluation results.

Comparative Example 3 Evaluation was performed in the same manner as in Example 3 except that the crystalline propylene homopolymer (C) was omitted, and a polypropylene random copolymer composition shown in Table 1 was obtained. Table 2 shows the evaluation results. If the composition of the copolymer or the composition of the composition is out of the range of the present invention, the film-forming properties, transparency, low-temperature heat sealability, poor balance between solvent resistance and hot tack property, and the object of the present invention Cannot be achieved.

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

Industrial Applicability According to the present invention, a polypropylene composition which gives a film for laminating and stretching which is excellent in film-forming properties of a film and which has an excellent balance between solvent resistance and hot tack property, and a laminate having such a composition in a surface layer A stretched film can be obtained.

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Atsushi Ohara 5-1, Anesaki Beach, Ichihara-shi, Chiba Sumitomo Chemical Co., Ltd. (56) References JP-A-63-276541 (JP, A) JP-A-61- 169246 (JP, A) JP-A-54-95684 (JP, A) JP-A-54-48846 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 23/10-23 /14

Claims (7)

(57) [Claims] (A) A propylene component content of 60 to 97% by weight and a ethylene component content of 0 to 6% by weight obtained by copolymerizing propylene and an α-olefin or propylene, an α-olefin and ethylene. And a crystalline propylene random copolymer having an α-olefin content of 3 to 40% by weight and a xylene-soluble component at 20 ° C. (hereinafter referred to as CXS) of 25% by weight or less, (B)
The propylene component content obtained by polymerizing propylene and an α-olefin is 35 to 75% by weight, the α-olefin component content is 25 to 65% by weight, and CXS is 3%.
It is characterized by comprising 2.5 to 17% by weight of a propylene / α-olefin random copolymer which is 0% by weight or more, and 0.5 to 10% by weight of a crystalline propylene homopolymer (C). A polypropylene composition for a laminated stretched film. 2. A crystalline propylene random copolymer (A)
2. The polypropylene composition for a laminated stretched film according to claim 1, wherein the propylene content of the polypropylene is 65 to 92% by weight. 3. A propylene / α-olefin random copolymer (B) is produced by using a solid catalyst component containing Ti, Mg, halogen and an electron donor as essential components in the presence of a solvent to form propylene and an α-olefin. The polypropylene composition for a laminated stretched film according to claim 1, which is obtained by polymerizing 4. The polypropylene composition for a laminated stretched film according to claim 1, wherein the α-olefin is butene-1. 5. The method according to claim 1, wherein the crystalline propylene homopolymer (C) is D
The polypropylene composition for a laminated stretched film according to claim 1, wherein the polypropylene composition is a crystalline propylene homopolymer having a melting point of 150 ° C or higher as measured by SC. 6. The polypropylene composition for a laminated stretched film according to claim 1, wherein the xylene-soluble content of the composition at 20 ° C. is 20% by weight or less. 7. A laminated stretched film having the polypropylene composition for a laminated stretched film according to any one of claims 1 to 6 as a surface layer.