KR20200132922A - Propylene resin composition, film using same, and use thereof - Google Patents

Abstract

[Problem] The present invention is a propylene-based resin composition capable of producing a film suitably usable as a high retort CPP, which is highly excellent in impact resistance at low temperatures and heat sealing strength after retort, as well as excellent rigidity and transparency, It is an object to provide a film and a laminate using the same, and a retort pouch. [Solution] The propylene resin composition of the present invention contains 75 to 95 mass% of a propylene-ethylene block copolymer (A) satisfying the following requirements (a-1) to (a-4), and a specific ethylene/α -It contains 5 to 25 mass% of olefin copolymer (B). (a-1) MFR is 2.0 to 8.0 g/10 min. (a-2) The amount of paraxylene soluble component is 15 mass% or more, and the amount of paraxylene soluble component (mass%) and the amount of n-decane soluble component (mass%) satisfy the specific relational expression (1). (a-3) The content of the structural unit derived from ethylene in the paraxylene-soluble component is 20 to 30 mass%. (a-4) In the paraxylene insoluble component, the pentad isotactic fraction is 94 mol% or more.

Description

Propylene resin composition, film using same, and use thereof

The present invention relates to a propylene resin composition suitable for CPP use, a film and a laminate made of the resin composition, and uses thereof. Specifically, the present invention relates to a propylene-based resin composition, a film and a laminate film using the same, and a retort pouch suitable for formation of a high-retort CPP layer having excellent impact resistance at low temperature and sterilizing at high temperature.

The retort packaging material is used for the purpose of long-term storage of the contents by filling the contents in the packaging material, sealing it and then performing heat sterilization at a temperature exceeding 100°C. The heat sterilization treatment of the retort packaging material is roughly classified into semi-retort (treatment temperature ≤ 120°C) and high retort (treatment temperature> 120°C) depending on the temperature.

Retort packaging materials are usually bonded with a surface protection/printing layer (such as polyethylene terephthalate (PET) film), a barrier layer (such as aluminum foil), and a heat sealing layer (such as a polyolefin film) through an adhesive. It has one configuration and is in contact with the contents because the heat sealing layer becomes the inside of the bag.

Conventionally, a polyolefin film having excellent heat sealing properties has been used for the heat sealing layer of a retort packaging material. As packaging materials for semi-retort, polyethylene-based resins such as LLDPE and HDPE having a relatively high density, and polypropylene-based resins having improved impact resistance by blending random PP with an elastomer component and the like are used.

On the other hand, in the packaging material for high retort, since the above material lacks heat resistance, a composition in which an elastomer component is further added to a propylene-ethylene copolymer (so-called block PP) is used, and a CPP film (poly A propylene-based non-oriented film) has been suitably used.

In addition, in order to cope with microwave heating in recent years, instead of using an aluminum foil for the barrier layer, a transparent type retort pouch using a barrier substrate such as inorganic vapor deposition PET has also been used.

For this reason, the heat sealing layer has a heat sealing strength required to protect the contents during heat sterilization or storage, sufficient impact resistance to withstand the drop of the bag filled with the contents, heat resistance to withstand heat sterilization, and low flavor that does not impair the flavor of the contents. Brittleness is required. Furthermore, in the transparent type retort pouch, it is required to have excellent transparency even for the CPP film serving as the sealant layer.

Various resin compositions used as the material of the CPP film have been proposed so far. For example, in Patent Documents 1 to 9, a resin composition containing a specific propylene/ethylene copolymer and an ethylene/α-olefin copolymer Or, in addition, a resin composition containing a hydrogenated styrene-based thermoplastic elastomer, polyethylene, or the like has been proposed. And by these, the CPP film which has heat sealing property, suppression of an orange peel phenomenon, and low temperature impact resistance is taught.

High retort CPP using block PP is excellent in heat resistance and relatively excellent in impact resistance, but it has a matrix/domain structure of a polypropylene homopolymer part and an ethylene/propylene rubber/polyethylene part, so the transparency may be insufficient. . In addition, the impact resistance is not necessarily satisfied with a large pouch or the like with a large inner volume, and the addition of an elastomer component (a low-density ethylene/α-olefin copolymer, etc.) has been performed.

In addition, since the addition of the elastomer component may cause problems such as a decrease in heat sealing strength after retort sterilization, a decrease in rigidity, and a decrease in blocking resistance, a high retort CPP film excellent in these properties is desired.

That is, the impact resistance at low temperature and heat sealing strength after retort sterilization are more excellent, and rigidity and transparency are also excellent, and the appearance of a CPP film suitable for high retort use has been desired.

The present inventors have excellent impact resistance at low temperature and heat sealing strength after retort by blending a specific amount of an ethylene/α-olefin copolymer of a specific composition to a propylene/ethylene block copolymer having a specific composition, and also rigidity. , The present invention was completed by finding that a highlet CPP film excellent in transparency was obtained.

Japanese Patent Publication No. 2015-168766 WO2017/38349 pamphlet Japanese Patent Laid-Open No. 2012-172124 Japanese Patent Application Publication No. 2006-104279 Japanese Patent Laid-Open No. 2010-150318 Japanese Patent Laid-Open No. 2000-256532 Japanese Patent Laid-Open No. 2003-183462 Japanese Patent Laid-Open No. 2003-96251 Japanese Patent Publication No. 2001-288330

The present invention is a propylene-based resin composition capable of producing a film suitable for use as a high retort CPP, which is excellent in impact resistance at low temperature and heat sealing strength after retort, as well as excellent rigidity and transparency, and a film using the same And it is an object to provide a laminate and a retort pouch.

The inventors of the present invention have studied intensively in order to achieve the above problems, and as a result, a resin composition containing a propylene/ethylene block copolymer showing specific properties and an ethylene/α-olefin copolymer is a film raw material for high retort CPP. In particular, it was found to be excellent, and the present invention was completed.

That is, the gist of the present invention relates to the following matters [1] to [7].

[1] 75 to 95 mass% of propylene-ethylene block copolymer (A) satisfying the following requirements (a-1) to (a-4),

A propylene-based resin composition comprising 5 to 25% by mass of an ethylene/α-olefin copolymer (B) satisfying the following requirements (b-1) and (b-2).

(a-1) The melt flow rate (230°C, 2.16 kg load) is 2.0 to 8.0 g/10 minutes.

(a-2) The amount of the paraxylene-soluble component is 15% by mass or more, and the amount of the paraxylene-soluble component (mass%) and the amount of the n-decane-soluble component (mass%) satisfy the following relational expression (1).

n-decane soluble component amount ≤ paraxylene soluble component amount × 0.95. (One)

(a-3) The content of the structural unit derived from ethylene in the paraxylene-soluble component is 20 to 30 mass%.

(a-4) In the paraxylene insoluble component, the pentad isotactic fraction (mmmm fraction) is 94 mol% or more.

(b-1) Melt flow rate (190°C, 2.16 kg load) is 0.5 to 5.0 g/10 minutes.

(b-2) The density is 890kg/m ³ ∼910kg/m ³ .

[2] The propylene resin composition according to [1], wherein the ethylene/α-olefin copolymer (B) further satisfies the requirement (b-3).

(b-3) The density X (kg/m ³ ) and the n-decane soluble component amount Y (mass %) satisfy the following relational expression (2).

Y≤0.0046X ² -8.578X+4000… (2)

[3] A film comprising the propylene-based resin composition according to [1] or [2].

[4] The film according to [3], which is a non-stretched film.

[5] A laminated film comprising a layer made of the propylene resin composition according to [1] or [2].

[6] The laminated film according to [5], wherein the layer made of the propylene resin composition according to [1] or [2] is provided as a surface layer on one side.

[7] A retort pouch comprising the laminated film according to [6].

The propylene resin composition of the present invention is suitable for production of films such as high retort CPP films, and is also excellent in blocking resistance. The film obtained from the propylene-based resin composition of the present invention has excellent heat sealing properties, high heat sealing strength, is suitable as an inner layer surface of a retort pouch, has excellent impact resistance at low temperatures, and has excellent quality as a high retort CPP film. In addition to excellence, transparency and rigidity are also excellent. The laminate of the present invention and the retort pouch comprising the same have excellent anti-blocking properties, so they have excellent handling properties when filling the contents, have high heat sealing strength, and have excellent heat sealing strength after retort sterilization treatment.

Hereinafter, the present invention will be described in detail.

<Propylene resin composition>

The propylene resin composition of the present invention contains a specific propylene/ethylene block copolymer (A) and an ethylene/α-olefin copolymer (B) as essential components.

Propylene/ethylene block copolymer (A)

The propylene-ethylene block copolymer (A) used in the present invention satisfies the following requirements (a-1) to (a-4). As long as the propylene-ethylene block copolymer (A) according to the present invention satisfies the following requirements (a-1) to (a-4), the polymerization catalyst or polymerization conditions used in its production are not particularly limited. . Moreover, the propylene-ethylene block copolymer (A) which concerns on this invention may be used individually by 1 type, and may be used in combination of 2 or more types. When two or more types are used in combination, the following requirements (a-1) to (a-4) are satisfied as the whole propylene/ethylene block copolymer combined.

(a-1) The melt flow rate (MFR) is 2.0 to 8.0 g/10 min. This MFR is a value measured under a load of 2.16 kg at 230° C. in accordance with ASTM D-1238, preferably 2.5 to 6.0 g/10 minutes, more preferably 3.0 to 5.0 g/10 minutes.

(a-2) The amount of the paraxylene-soluble component is 15% by mass or more, and the amount of the paraxylene-soluble component (mass%) and the amount of the n-decane-soluble component (mass%) satisfy the following relational expression (1).

n-decane soluble component amount ≤ paraxylene soluble component amount × 0.95. (One)

The amount of the paraxylene-soluble component of the propylene-ethylene block copolymer (A) is preferably 15 to 30% by mass, more preferably 20 to 30% by mass. In addition, the following relational expression (1') is preferably satisfied, and more preferably the following relational expression (1') is satisfied.

n-decane soluble component amount ≤ paraxylene soluble component amount × 0.90. (One')

0.80 ≤ n-decaine soluble component amount ≤ paraxylene soluble component amount × 0.90. (One'')

(a-3) The content of the structural unit derived from ethylene in the paraxylene-soluble component is 20 to 30 mass%. The content of the structural unit derived from ethylene in the paraxylene-soluble component is preferably 20 to 28 mass%, more preferably 22 to 28 mass%.

(a-4) In the paraxylene insoluble component, the pentad isotactic fraction (mmmm fraction) is 94 mol% or more. The isotactic fraction of pentade in the paraxylene insoluble component is preferably 94.5 mol% or more, and more preferably 95.0 mol% or more.

On the other hand, in the present invention, the amount of the paraxylene-soluble component, the amount of the paraxylene-insoluble component, and the amount of the n-decane-soluble component are ratios (mass%) determined by the test method described later.

The propylene/ethylene block copolymer (A) used in the present invention is usually a block copolymer having a propylene homopolymer portion and a propylene/ethylene random copolymer portion or an ethylene polymer portion. In the propylene-ethylene block copolymer (A) having a propylene homopolymer portion and a propylene-ethylene random copolymer portion, mainly the propylene-ethylene random copolymer portion becomes a paraxylene-soluble component and an n-decane-soluble component. The propylene homopolymer part becomes a paraxylene insoluble component and an n-decane insoluble component. Here, in paraxylene and n-decane, since n-decane becomes a poor solvent, a portion having some crystallinity in the copolymer is soluble in paraxylene and insoluble in n-decane. It is thought that there is a difference of becoming.

In the present invention, the ratio of the propylene-ethylene random copolymer portion is relatively higher than that of the conventional general-purpose propylene-ethylene block copolymer, and the ethylene content of the propylene-ethylene random copolymer portion is relatively low, and the propylene homopolymer portion has high stereoregularity. Moreover, by making a propylene-ethylene block copolymer (A) having a difference in the amount of paraxylene-soluble component and the amount of n-decane-soluble component as a main component of the propylene-based resin composition, the film obtained from the resin composition is particularly It shows properties suitable for the use of high retort CPP film.

That is, the propylene-ethylene block copolymer (A) according to the present invention satisfies the above requirements (a-1) to (a-4), and thus the copolymer (A) and ethylene-α obtained later -A resin composition containing an olefin copolymer (B) in a specific amount ratio is suitable for formation of films such as high retort CPP films, and the resulting film has heat sealing properties, impact resistance at low temperatures, heat sealing strength after retort, and rigidity , Transparency, and other properties can be achieved.

-Method for producing propylene-ethylene block copolymer (A)

The propylene-ethylene block copolymer (A) according to the present invention is not limited in its production method as described above, and the polymerization catalyst used in production and polymerization conditions are not particularly limited, but, for example, Ziegler-Natta system In the presence of an olefin stereoregular catalyst such as a catalyst or a metallocene catalyst, in the first polymerization step, a homopolymer portion of propylene or a random propylene-ethylene copolymer portion composed of propylene and a small amount of ethylene is prepared, and then a second polymerization step It is obtained by copolymerizing propylene with a larger amount of ethylene than in the first step to prepare a propylene-ethylene copolymer elastomer part.

In the production of the propylene-ethylene block copolymer (A) according to the present invention, as a polymerization catalyst, for example, a solid titanium catalyst component (I) described below, an organometallic compound catalyst component (II), and According to the requirements (a-1) to (a-4), both of the above requirements (a-1) to (a-4) are satisfied by polymerizing propylene and further copolymerizing propylene and ethylene using a catalyst for olefin polymerization containing an electron donor. The propylene-ethylene block copolymer (A) to be made can be manufactured suitably.

[Solid titanium catalyst component (I)]

The solid titanium catalyst component (I) constituting the catalyst for olefin polymerization includes, for example, titanium, magnesium, halogen and, if necessary, an electron donor. Known components can be used for the solid titanium catalyst component (I) without limitation.

In preparation of the solid titanium catalyst component (I), a magnesium compound and a titanium compound are usually used.

Specific examples of the magnesium compound include magnesium halides such as magnesium chloride and magnesium bromide; Alkoxymagnesium halides such as magnesium methoxychloride, magnesium ethoxychloride, and magnesium phenoxychloride; Alkoxy magnesium, such as ethoxy magnesium, isopropoxy magnesium, butoxy magnesium, and 2-ethylhexoxy magnesium; Aryloxy magnesium such as phenoxymagnesium; Carboxylate salts of magnesium such as magnesium stearate; And the like. Magnesium compounds may be used alone, or may be used in combination of two or more. Further, the magnesium compound may be a complex compound with another metal, a complex compound, or a mixture with another metal compound.

Among them, a magnesium compound containing halogen is preferable, and magnesium halide, particularly magnesium chloride is more preferable. In addition, alkoxy magnesium such as ethoxy magnesium is also preferable. Further, the magnesium compound may be a compound derived from another substance, for example, a compound obtained by contacting an organic magnesium compound such as a Grignard reagent with a titanium halide, a silicon halide, an alcohol halide, or the like.

As a titanium compound, a tetravalent titanium compound represented by the following formula is mentioned, for example.

Ti(OR) _g X _4-g

(In the formula, R is a hydrocarbon group, X is a halogen atom, and g is 0≤g≤4.)

Specific examples of the titanium compound include tetrahalogenated titanium such as TiCl ₄ and TiBr ₄ ; Tries such as Ti(OCH ₃ )Cl ₃ , Ti(OC ₂ H ₅ )Cl ₃ , Ti(OnC ₄ H ₉ )Cl ₃ , Ti(OC ₂ H ₅ )Br ₃ , Ti(OiC ₄ H ₉ )Br ₃ Halogenated alkoxy titanium; Dihalogenated alkoxy titanium, such as Ti(OCH ₃ ) ₂ Cl ₂ and Ti(OC ₂ H ₅ ) ₂ Cl ₂ ; Monohalogenated alkoxy titanium such as Ti(OCH ₃ ) ₃ Cl, Ti(OnC ₄ H ₉ ) ₃ Cl, and Ti(OC ₂ H ₅ ) ₃ Br; Tetraalkoxy titanium, such as Ti(OCH ₃ ) ₄ , Ti(OC ₂ H ₅ ) ₄ , Ti(OC ₄ H ₉ ) ₄ , and Ti(O-2-ethylhexyl) ₄ ; And the like. A titanium compound may be used individually by 1 type, and may be used in combination of 2 or more types. Among them, tetrahalogenated titanium is preferable, and titanium tetrachloride is more preferable.

As the magnesium compound and the titanium compound, for example, compounds described in detail in Japanese Unexamined Patent Application Publication No. 57-63310 and Japanese Unexamined Patent Application Publication No. Hei 5-170843 can also be used.

As a specific example of the preferable preparation method of the solid titanium catalyst component (I) used when producing the propylene-ethylene block copolymer (A) according to the present invention, the following methods (P-1) to (P-4) are mentioned. I can.

(P-1) A solid adduct consisting of an electron donor component (1) such as a magnesium compound and an alcohol, an electron donor component (2) described later, and a titanium compound in a liquid state, in a suspended state in the presence of an inert hydrocarbon solvent How to make contact.

(P-2) A method in which a solid adduct consisting of a magnesium compound and an electron donor component (1), an electron donor component (2), and a titanium compound in a liquid state are divided into contact with a plurality of times.

(P-3) A solid adduct consisting of a magnesium compound and an electron donor component (1), an electron donor component (2), and a titanium compound in a liquid state are brought into contact with each other in a suspended state in the presence of an inert hydrocarbon solvent, and a plurality of How to divide circuit and make contact.

(P-4) A method of contacting a liquid magnesium compound comprising a magnesium compound and an electron donor component (1), a liquid titanium compound, and an electron donor component (2).

The reaction temperature when preparing the solid titanium catalyst component (I) is preferably in the range of -30 to 150°C. Specifically, for example, a magnesium compound and a titanium compound are brought into contact at a temperature of 120 to 150°C in the presence of an electron donating compound and, if necessary, a silicon compound, and then with an inert solvent at a temperature of 100 to 150°C. It can be prepared by washing.

The preparation of the solid titanium catalyst component (I) may be performed in the presence of a known medium as necessary. Specific examples of the medium include slightly polar aromatic hydrocarbons such as toluene, and known aliphatic hydrocarbons or alicyclic hydrocarbon compounds such as heptane, octane, decane, and cyclohexane. Among them, aliphatic hydrocarbons are preferred.

As the electron donor component (1) used in the formation of a solid adduct or a liquid magnesium compound, a known compound capable of solubilizing a magnesium compound at a temperature range of about room temperature to 300°C is preferable. For example, alcohol, Aldehydes, amines, carboxylic acids and mixtures thereof and the like are preferred. Examples of these compounds include compounds described in JP-A-57-63310 A and JP-A 5-170843.

Specific examples of alcohols capable of solubilizing a magnesium compound include methanol, ethanol, propanol, butanol, isobutanol, ethylene glycol, 2-methylpentanol, 2-ethylbutanol, n-heptanol, and n-octane. Aliphatic alcohols such as ol, 2-ethylhexanol, decanol, and dodecanol; Alicyclic alcohols such as cyclohexanol and methylcyclohexanol; Aromatic alcohols such as benzyl alcohol and methylbenzyl alcohol; aliphatic alcohols having an alkoxy group such as n-butyl cellosolve; And the like.

As a specific example of a carboxylic acid, C7 or more organic carboxylic acids, such as caprylic acid and 2-ethylhexanoic acid, are mentioned. Specific examples of the aldehyde include aldehydes having 7 or more carbon atoms such as capric aldehyde and 2-ethylhexylaldehyde. As a specific example of an amine, C6 or more amines, such as heptylamine, octylamine, nonylamine, laurylamine, and 2-ethylhexylamine, are mentioned.

As the electron donor component (1), the above alcohols are preferable, and in particular, ethanol, propanol, butanol, isobutanol, hexanol, 2-ethylhexanol, and decanol are preferable.

The composition ratio of magnesium and electron donor component (1) in the obtained solid adduct or liquid magnesium compound differs depending on the type of compound to be used, so it cannot be uniformly defined, but for 1 mol of magnesium in the magnesium compound, the electron donor The component (1) is preferably 2 mol or more, more preferably 2.3 mol or more, particularly preferably 2.7 mol or more and 5 mol or less.

As a particularly preferred example of an electron donor used as needed for the solid titanium catalyst component (I), an aromatic carboxylic acid ester and/or a compound having two or more ether bonds through a plurality of carbon atoms (hereinafter, ``electron donor component (2)) 」).

As the electron donor component (2), known aromatic carboxylic acid esters and polyether compounds that are suitably used for catalysts for olefin polymerization in the related art, for example, JP 5-170843 or JP 2001-354714 The compounds described in the publications and the like can be used without limitation.

Specific examples of the aromatic carboxylic acid ester include aromatic carboxylic acid monoesters such as benzoic acid esters and toluic acid esters, as well as aromatic polyhydric carboxylic acid esters such as phthalic acid esters. Among them, aromatic polyhydric carboxylic acid esters are preferable, and phthalic acid esters are more preferable. As these phthalic esters, alkyl phthalate esters such as ethyl phthalate, n-butyl phthalate, isobutyl phthalate, hexyl phthalate, and heptyl phthalate are preferable, and diisobutyl phthalate is particularly preferable.

As a polyether compound, a compound specifically represented by the following structural formula is mentioned.

[Formula 1]

In the above formula, m is an integer of 1 ≤ m ≤ 10, more preferably an integer of 3 ≤ m ≤ ¹⁰ , and R ¹¹ to R ³⁶ are each independently a hydrogen atom, or carbon, hydrogen, oxygen, fluorine, It is a substituent having at least one element selected from chlorine, bromine, iodine, nitrogen, sulfur, phosphorus, boron and silicon. When m is 2 or more, a plurality of R ¹¹ and R ¹² may be the same or different, respectively. Any of R ¹¹ to R ³⁶ , preferably R ¹¹ and R ¹² may jointly form a ring other than a benzene ring.

Specific examples of such compounds include 2-isopropyl-1,3-dimethoxypropane, 2-s-butyl-1,3-dimethoxypropane, and 2-cumyl-1,3-dimethoxypropane. Monosubstituted dialkoxypropanes such as Paine; 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2-methyl-2-isopropyl-1,3 -Dimethoxypropane, 2-methyl-2-cyclohexyl-1,3-dimethoxypropane, 2-methyl-2-isobutyl-1,3-dimethoxypropane, 2,2-dia Isobutyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-diethoxypro Paine, 2,2-diisobutyl-1,3-dibutoxypropane, 2,2-di-s-butyl-1,3-dimethoxypropane, 2,2-dineopentyl-1 ,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane, etc. Disubstituted dialkoxypropanes of; 2,3-dicyclohexyl-1,4-diethoxybutane, 2,3-dicyclohexyl-1,4-diethoxybutane, 2,3-diisopropyl-1,4-die Toxibutane, 2,4-diphenyl-1,5-dimethoxypentane, 2,5-diphenyl-1,5-dimethoxyhexane, 2,4-diisopropyl-1,5- Dialkoxy alkanes such as dimethoxypentane, 2,4-diisobutyl-1,5-dimethoxypentane, and 2,4-diisoamyl-1,5-dimethoxypentane; 2-methyl-2-methoxymethyl-1,3-dimethoxypropane, 2-cyclohexyl-2-ethoxymethyl-1,3-diethoxypropane, 2-cyclohexyl-2-methoxy Trialkoxy alkanes such as methyl-1,3-dimethoxypropane; And the like. One type of polyether compound may be used alone, or two or more types may be used in combination. Among them, 1,3-dieters are preferable, and in particular, 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dime Toxoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2,2-bis(cyclohexyl Methyl)-1,3-dimethoxypropane is preferred.

In the solid titanium catalyst component (I), the halogen/titanium (atomic ratio) (i.e., the number of moles of halogen atoms/the number of moles of titanium atoms) is 2 to 100, preferably 4 to 90, and the electron donor component ( 1)/titanium atom (molar ratio) is 0 to 100, preferably 0 to 10, and the electron donor component (2)/titanium atom (molar ratio) is 0 to 100, preferably 0 to 10. The magnesium/titanium (atomic ratio) (that is, the number of moles of magnesium atoms/the number of moles of titanium atoms) is 2 to 100, preferably 4 to 50.

The solid titanium catalyst component (I) may be supported on an organic carrier or an inorganic carrier, and inorganic porous powders such as silica are suitably used as the carrier.

As a more detailed preparation condition for the solid titanium catalyst component (I), except for using the electron donor component (2), for example, conditions described in EP585869A1 or Japanese Patent Laid-Open No. Hei 5-170843 can be suitably used. .

[Organic metal compound catalyst component (II)]

The organometallic compound catalyst component (II) is a component containing a metal element selected from Group 1, Group 2, and Group 13 of the periodic table. For example, a compound containing a group 13 metal (organic aluminum compound, etc.), a complex alkylated product of a group 1 metal and aluminum, an organic metal compound of a group 2 metal, or the like can be used. Among them, organic aluminum compounds are preferred.

As the organometallic compound catalyst component (II), specifically, an organometallic compound catalyst component described in a known document such as EP585869A1 can be suitably used.

In the production of the propylene-ethylene block copolymer (A) according to the present invention, together with the above-described solid titanium catalyst component (I) and organometallic compound catalyst component (II), to the extent that the object is not impaired, the aforementioned electron donor In addition to the component (1) and the electron donor component (2), a known electron donor component (3) can be combined and used for prepolymerization and/or main polymerization.

As the electron donor component (3), an organosilicon compound is preferable. This organosilicon compound is, for example, a compound represented by the following formula.

R _n Si(OR') _4-n

(In the formula, R and R'are hydrocarbon groups, and n is an integer of 0<n<4.)

Specific examples of the organosilicon compound represented by the above formula include diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, and t-amylmethyldiethoxysilane. , Dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane Phosphorus, phenyltriethoxysilane, diphenyldimethoxysilane, cyclohexyltrimethoxysilane, cyclopentyltrimethoxysilane, 2-methylcyclopentyltrimethoxysilane, cyclopentyltri Ethoxysilane, dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane, tricyclopentylmethoxysilane, dicyclopentylmethylmethoxysilane, dicyclopentylethylmethoxysilane, cyclo Pentyldimethylethoxysilane or the like is used. Among them, vinyltriethoxysilane, diphenyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, and dicyclopentyldimethoxysilane are preferable.

Further, a silane compound represented by the following formula described in the pamphlet of International Publication No. 2004/016662 is also a preferred example of an organosilicon compound.

Si(OR ^a ) ₃ (NR ^b R ^c )

In the above formula, R ^a is a hydrocarbon group having 1 to 6 carbon atoms. For example, it is an unsaturated or saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, and a hydrocarbon group having 2 to 6 carbon atoms is particularly preferable. Specific examples include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, n-pentyl group, iso-pentyl group, cyclopentyl group, n-hexyl group And a cyclohexyl group. Among them, an ethyl group is particularly preferred.

R ^b is a C1-C12 hydrocarbon group or hydrogen. For example, it is a C1-C12 unsaturated or saturated aliphatic hydrocarbon group or hydrogen. Specific examples include hydrogen atom, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, n-pentyl group, iso-pentyl group, cyclopentyl group, n -Hexyl group, cyclohexyl group, octyl group, etc. are mentioned. Among them, an ethyl group is particularly preferred.

R ^c is a hydrocarbon group having 1 to 12 carbon atoms. For example, it is a C1-C12 unsaturated or saturated aliphatic hydrocarbon group. Specific examples include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, n-pentyl group, iso-pentyl group, cyclopentyl group, n-hexyl group , A cyclohexyl group, an octyl group, and the like. Among them, an ethyl group is particularly preferred.

Specific examples of the organosilicon compound represented by the above formula include dimethylaminotriethoxysilane, diethylaminotriethoxysilane, diethylaminotrimethoxysilane, and diethylaminotri-n-propoxysilane. , Di-n-propylamino triethoxysilane, methyl n-propylamino triethoxysilane, t-butylamino triethoxysilane, ethyl n-propylamino triethoxysilane, ethyl iso-propylamino Triethoxysilane, methylethylamino triethoxysilane, etc. are mentioned.

Moreover, as another example of an organosilicon compound, a compound represented by the following formula is also mentioned.

RNSi(OR ^a ) ₃

In the above formula, RN is a cyclic amino group. Specific examples include perhydroquinolino group, perhydroisoquinolino group, 1,2,3,4-tetrahydroquinolino group, 1,2,3,4-tetrahydroisoquinolino group, octamethyleneimino group, etc. Can be mentioned. R ^a is the same as above.

Specific examples of the organosilicon compound represented by the above formula include (perhydroquinolino) triethoxysilane, (perhydroisoquinolino) triethoxysilane, (1,2,3,4-tetrahydroquinolino). ) Triethoxysilane, (1,2,3,4-tetrahydroisoquinolino) triethoxysilane, octamethylene imino triethoxysilane, and the like.

Each of the organosilicon compounds described above may be used in combination of two or more.

As an aspect of the catalyst used in the production of the propylene-ethylene block copolymer (A) according to the present invention, specifically, in addition to the aspect described in each of the aforementioned documents, for example, Japanese Patent Laid-Open No. 2000-219787, Japanese Patent The aspects described in Unexamined Publication No. Hei 2-84404 and Japanese Unexamined Patent Publication No. 2002-30128, etc. are mentioned.

[polymerization]

The propylene-ethylene block copolymer (A) according to the present invention is the presence of a prepolymerization catalyst obtained by polymerizing propylene in the presence of the catalyst for olefin polymerization described above, and then copolymerizing propylene and ethylene, or prepolymerizing Then, propylene is polymerized, and then propylene and ethylene are copolymerized.

It is more preferable that the propylene/ethylene block copolymer (A) according to the present invention is produced in the presence of a prepolymerization catalyst.

The prepolymerization is carried out by prepolymerizing olefins in an amount of usually 0.1 to 1000 g, preferably 0.3 to 500 g, particularly preferably 1 to 200 g per 1 g of the catalyst for olefin polymerization. In the prepolymerization, a catalyst having a higher concentration than the catalyst concentration in the system in the main polymerization can be used.

The concentration of the solid titanium catalyst component (I) in the prepolymerization is usually 0.001 to 200 mmol, preferably 0.01 to 50 mmol, more preferably 0.1 to 20 mmol, in terms of titanium atoms per 1 liter of the liquid medium.

The amount of the organometallic compound catalyst component (II) in the prepolymerization may be an amount that usually produces 0.1 to 1000 g, preferably 0.3 to 500 g of polymer per 1 g of the solid titanium catalyst component (I), and the solid titanium catalyst component ( It is usually 0.1 to 300 moles, preferably 0.5 to 100 moles, more preferably 1 to 50 moles per mole of titanium atom in I).

In the prepolymerization, if necessary, the electron donor component may be used. In this case, these components are usually 0.1 to 50 moles, preferably 0.5 to 30 moles, per mole of titanium atoms in the solid titanium catalyst component (I). It is preferably 1 to 10 moles.

The prepolymerization can be carried out under mild conditions by adding an olefin and the above catalyst component to an inert hydrocarbon medium. When using an inert hydrocarbon medium, it is preferable to perform prepolymerization in a batch system.

Specific examples of the inert hydrocarbon medium include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; Alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, cycloheptane, methylcycloheptane, and cyclooctane; Aromatic hydrocarbons such as benzene, toluene, and xylene; Halogenated hydrocarbons such as ethylene chloride and chlorobenzene; Or a mixture of these, etc. are mentioned. Among them, aliphatic hydrocarbons are preferred.

Prepolymerization can also be carried out using olefin itself as a solvent. Further, prepolymerization may be performed in a substantially solvent-free state. In this case, it is preferable to continuously perform prepolymerization.

The olefin used in the prepolymerization may be the same as or different from the olefin used in the main polymerization described later. As the olefin, propylene is particularly preferred.

The temperature during prepolymerization is usually -20 to 100°C, preferably -20 to 80°C, and more preferably 0 to 40°C.

Next, a description will be given of the main polymerization carried out after via the prepolymerization or without via the prepolymerization.

The main polymerization can be divided into a process for producing a propylene homopolymer component and a process for producing a propylene-ethylene copolymer component.

The main polymerization (and prepolymerization) can be carried out in any of a liquid phase polymerization method such as a bulk polymerization method, a solution polymerization method, and a suspension polymerization method, or a gas phase polymerization method. As a process for producing the propylene homopolymer component, liquid phase polymerization such as bulk polymerization or suspension polymerization or gas phase polymerization is preferable. As a process for producing the propylene-ethylene copolymer component, liquid phase polymerization such as bulk polymerization or suspension polymerization or gas phase polymerization is preferable, and gas phase polymerization is more preferable.

When the main polymerization adopts the reaction mode of slurry polymerization, as the reaction solvent, an inert hydrocarbon used in the prepolymerization described above may be used, or an olefin which is a liquid in terms of reaction temperature and pressure may be used.

In the main polymerization, the solid titanium catalyst component (I) is used in an amount of usually 0.0001 to 0.5 mmol, preferably 0.005 to 0.1 mmol, in terms of titanium atoms per 1 liter of polymerization volume. In addition, the organometallic compound catalyst component (II) is usually used in an amount of 1 to 2000 moles, preferably 5 to 500 moles, per 1 mole of titanium atoms in the prepolymerization catalyst component in the polymerization system. When an electron donor component is used, it is used in an amount of usually 0.001 to 50 moles, preferably 0.01 to 30 moles, and more preferably 0.05 to 20 moles per 1 mole of the organometallic compound catalyst component (II).

When the main polymerization is carried out in the presence of hydrogen, the molecular weight of the resulting polymer can be adjusted (lowered), and a polymer having a large melt flow rate (MFR) can be obtained. Since the amount of hydrogen required to adjust the molecular weight varies depending on the type of production process to be used, the polymerization temperature, and pressure, it may be appropriately adjusted.

In the process of producing the propylene homopolymer component, the MFR can be adjusted by adjusting the polymerization temperature and the amount of hydrogen. Further, also in the process of producing a propylene-ethylene copolymer component, the intrinsic viscosity can be adjusted by adjusting the polymerization temperature, pressure, and amount of hydrogen.

In the main polymerization, the polymerization temperature of the olefin is usually 0 to 200°C, preferably 30 to 100°C, and more preferably 50 to 90°C. The pressure (gauge pressure) is usually normal pressure to 100 kgf/cm ² (9.8 MPa), preferably ² to 50 kgf/cm ² (0.20 to 4.9 MPa).

In the production of the propylene-ethylene block copolymer (A), polymerization can be carried out in any of batch, semi-continuous, and continuous methods. Furthermore, the shape of the reactor can be either a tubular type or a modeling type. Furthermore, the polymerization can be carried out by dividing into two or more stages by changing the reaction conditions. In this case, it is possible to combine coronal and molding.

In order to obtain the propylene-ethylene copolymer part in the propylene-ethylene block copolymer (A), the ethylene/(ethylene+propylene) gas ratio is controlled in the polymerization process 2 mentioned later. The ethylene/(ethylene+propylene) gas ratio is usually 5 to 80 mol%, preferably 10 to 70 mol%, and more preferably 15 to 60 mol%.

The n-decane-insoluble component and the paraxylene-insoluble component of the propylene-ethylene block copolymer (A) are mainly composed of a propylene homopolymer component. On the other hand, the n-decane-soluble component and the paraxylene-soluble component are mainly composed of an ethylene/propylene copolymer component which is a rubber component. For example, a propylene-ethylene block copolymer (A) is obtained by performing the following two polymerization steps 1 and 2 continuously.

(Polymerization process 1)

A step of polymerizing propylene in the presence of a solid titanium catalyst component to produce a propylene homopolymer component (propylene homopolymer production step).

(Polymerization process 2)

A process for producing an ethylene/propylene copolymer component by copolymerizing propylene and ethylene in the presence of a solid titanium catalyst component (copolymer rubber production process).

In particular, it is more preferable to perform the polymerization step 1 at the front end and to perform the polymerization step 2 at the rear end. Each polymerization step 1 and 2 can also be performed using two or more polymerization tanks. The content of the n-decane-soluble component and the paraxylene-soluble component of the propylene-ethylene block copolymer (A) can be adjusted by the polymerization time (retention time) of the polymerization step 1 and the polymerization step 2. In addition, the polymerization step 1 of the previous stage may be performed in a series of two or more polymerization reactors. In that case, the ratio of propylene and hydrogen in each stage may be different for each polymerization reactor.

Ethylene/α-olefin copolymer (B)

The ethylene/α-olefin copolymer (B) used in the present invention satisfies the following requirements (b-1) and (b-2). As long as the ethylene/α-olefin copolymer (B) according to the present invention satisfies the following requirements (b-1) and (b-2), the polymerization catalyst or polymerization conditions used in its production are not particularly limited. Does not. Further, the ethylene/α-olefin copolymer (B) according to the present invention may be used singly or in combination of two or more. When two or more types are used in combination, the following requirements (b-1) and (b-2) are satisfied as the entire combined ethylene/α-olefin copolymer.

(b-1) Melt flow rate (MFR) is 0.5 to 5.0 g/10 min. This melt flow rate is a value measured under a load of 190° C. and 2.16 kg in accordance with ASTM D-1238, preferably 0.5 to 4.0 g/10 minutes, more preferably 1.0 to 3.0 g/10 minutes.

(b-2) The density is 890kg/m ³ ∼910kg/m ³ . This density is preferably in the range of 890 to 905 kg/m ³ , more preferably 895 to 905 kg/m ³ .

The ethylene/α-olefin copolymer (B) according to the present invention is a resin obtained with the above-described propylene/ethylene block copolymer (A) by satisfying the above requirements (b-1) and (b-2). The film made of the composition is excellent in heat resistance and transparency, and particularly exhibits properties suitable for use in high retort CPP films.

It is preferable that the ethylene/α-olefin copolymer (B) according to the present invention further satisfies the following requirement (b-3) in addition to the above requirements (b-1) and (b-2).

(b-3) The density X (kg/m ³ ) and the n-decane soluble component amount Y (mass %) satisfy the following relational expression (2).

Y≤0.0046X ² -8.578X+4000… (2)

More preferably, the density X (kg/m ³ ) and the n-decane soluble component amount Y (mass %) satisfy the following relational expression (2').

Y≤0.00465X ² -8.625X+4000… (2')

If the density (kg/m ³ ) and the n-decane soluble component amount Y (mass %) of the ethylene/α-olefin copolymer (B) satisfy the above relationship, it is preferable because it is excellent in blocking resistance.

The ethylene/α-olefin copolymer (B) according to the present invention is obtained by copolymerizing ethylene and an α-olefin in the presence of a copolymerization catalyst. As an α-olefin, an α-olefin having 3 to 20 carbon atoms, preferably propylene, 1-butene, 2-methyl-1-propene, 2-methyl-1-butene, 3-methyl-1-butene, 1 -Hexene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3- Dimethyl-1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, methylethyl-1-butene, 1-octene, methyl- 1-pentene, ethyl-1-hexene, dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, etc. are mentioned. As the α-olefin, among them, propylene, 1-butene, 1-pentene, 1-hexene and 1-octene are preferable. Moreover, it is also preferable that the α-olefin is an α-olefin having 4 to 20 carbon atoms, and among them, 1-butene, 1-pentene, 1-hexene and 1-octene are preferable. The α-olefin copolymerized with ethylene may be used alone or in combination of two or more.

The ethylene/α-olefin copolymer (B) according to the present invention is not particularly limited, but the content of the structural unit derived from ethylene is preferably 90 mol% or more of the total structural units.

· Method for producing ethylene/α-olefin copolymer (B)

As described above, the ethylene/α-olefin copolymer (B) according to the present invention is not limited in its production method, and the polymerization catalyst used during production and polymerization conditions are not particularly limited, but, for example, ethylene and , The above-described α-olefin can be obtained by copolymerizing in the presence of a known catalyst for olefin polymerization, and preferably, it can be obtained by copolymerizing in the presence of a metallocene catalyst.

Propylene resin composition

The propylene resin composition of the present invention is a resin composition containing 75 to 95% by mass of the above-described propylene/ethylene block copolymer (A) and 5 to 25% by mass of the aforementioned ethylene/α-olefin copolymer (B). . The propylene resin composition of the present invention preferably contains 75 to 90 mass% of a propylene/ethylene block copolymer (A) and 10 to 25 mass% of an ethylene/α-olefin copolymer (B).

In addition, the propylene-based resin composition of the present invention may contain components other than the propylene-ethylene block copolymer (A) and the ethylene-α-olefin copolymer (B) within the range not impairing the object of the present invention, but is preferable. Preferably, the total of the propylene/ethylene block copolymer (A) and the ethylene/α-olefin copolymer (B) is 90% by mass or more, more preferably 93% by mass or more, further preferably, of the total propylene resin composition. It is 95% by mass or more. Examples of the components other than (A) and (B) include resin components other than (A) and (B), known additives, etc., but when used for a retort packaging film use, components and contents suitable for food packaging It is desirable. As additives, known additives to olefin-based polymers can be used within a range that does not impair the object of the present invention. For example, antioxidants, nucleating agents, lubricants, flame retardants, anti-blocking agents, colorants, inorganic or organic substances And fillers.

The propylene-based resin composition of the present invention is not particularly limited, but the melt flow rate (MFR) measured under a load of 2.16 kg at 230° C. in accordance with ASTM D-1238 is preferably 2 to 8 g/10 minutes, more preferably It is 2-6 g/10 minutes. A propylene-based resin composition having such a melt flow rate is preferable because the film moldability is good and a film excellent in low-temperature impact strength can be produced.

The propylene resin composition of the present invention contains a propylene/ethylene block copolymer (A) and an ethylene/α-olefin copolymer (B) satisfying each of the above-described requirements in a specific amount ratio, thereby making a high retort CPP film. It is suitable for film production such as, and has excellent transparency and blocking resistance. In addition, in the case of manufacturing a film, a laminated film, and a retort pouch made of the resin composition, the heat sealing property is excellent, the heat sealing strength is high, and the high heat sealing strength can be maintained even after high temperature treatment such as retort sterilization treatment. In addition, it is excellent in transparency, rigidity, and impact resistance at low temperatures, and it can be said that the quality as a high retort CPP film is excellent.

· Method for producing propylene resin composition

The propylene resin composition of the present invention can be manufactured by various known methods. For example, by blending a propylene/ethylene block copolymer (A) and an ethylene/α-olefin copolymer (B) obtained in advance, and additives as necessary, various known such as Henschel mixers, ribbon blenders, and Banbury mixers. A method of mixing by using a conventional device, or after mixing, melt at 170 to 300°C, preferably 190 to 250°C, using various known kneaders such as a single screw extruder or twin screw extruder, Brabender or roll. The method of kneading, etc. are mentioned.

<Film>

The film of the present invention is obtained from the propylene resin composition of the present invention described above, and contains a sheet-like material. The film of the present invention can be produced by a known method of molding an olefin-based polymer into a film. Such a film is excellent in heat sealing property and also excellent in shock absorption.

The film of the present invention can be produced, for example, by a film molding machine equipped with a T-die or a circular die at the tip of the extruder.

The thickness of the film of the present invention can be determined in various ways depending on the application, but is usually in the range of 10 μm to 250 μm, preferably 15 μm to 200 μm. Even if the film of the present invention is a relatively thin film, it is excellent in impact resistance at low temperatures.

The film of the present invention may be either a non-stretched (unstretched) film or a stretched film. For example, when used as a retort film, it is preferably a non-stretched film (CPP film).

The film of the present invention can be used as a single-layered film or as a laminated film laminated with other layers for various applications. Preferred uses include, for example, food packaging materials, optical sheets or metal surface protection materials, medical packaging materials or freshness-keeping packaging materials, heat sealing layers (sealing layers) of a multilayer retort packaging film described later, etc. And particularly suitable as a high retort CPP film.

<Laminated film>

The laminated film of the present invention has a layer made of the above-described propylene resin composition of the present invention. The laminated film of the present invention is a film obtained by laminating a layer made of the propylene-based resin composition of the present invention and one or more other layers, and is used for bonding each layer by pressing, adhesive, etc., and forming another layer on a certain layer. It may be formed by any method such as integration or a combination thereof.

The laminated film of the present invention may have two or more layers, such as having a layer made of a propylene-based resin composition on both sides, or may have it in an inner layer, and the configuration is not limited, but preferably, a propylene-based resin composition The formed layer has as a surface layer on one side. In such a laminated film, a layer made of a propylene-based resin composition functions as a heat sealing layer and also has shock absorption, and is suitable as a film for retort packaging or the like.

When the laminated film of the present invention is a film for retort packaging, it is preferable to have a base layer and a barrier layer in addition to the layer made of the propylene resin composition of the present invention, and may further have an impact absorbing layer or the like.

Examples of the substrate layer include films of polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polycarbonate films, polyamide films such as nylon 6 and nylon 66, ethylene/vinyl alcohol copolymer films, and polyvinyl alcohol. Films, polyvinyl chloride films, polyvinylidene chloride films, polyolefin films such as polypropylene, paper, nonwoven fabrics, and fabrics are mentioned. When the base material layer is a resin film, the film may be a non-stretched film or a film stretched in a uniaxial or biaxial direction. It is also preferable that such a base layer has printability, heat resistance during heat sealing, a protective function of a barrier layer, and the like.

As the barrier layer, a layer having a light-shielding property, a barrier property of oxygen or water vapor, etc. is preferable. For example, a metal such as aluminum or zinc, an oxide or an inorganic material such as silica or aluminum oxide is deposited on a resin film such as PET. An inorganic vapor deposition film, an aluminum foil, and the like. As the impact absorbing layer, films, such as polyester (nylon), etc. are mentioned, for example.

When the laminated film of the present invention is a film for high retort packaging, for example, the layer structure of the layer/barrier layer/substrate layer made of the propylene-based resin composition of the present invention, the layer/barrier made of the propylene-based resin composition of the present invention The layer structure of a layer/impact absorption layer/base layer, etc. are mentioned as a suitable layer structure. In addition, an adhesive layer made of a known adhesive may be provided between each of these layers.

When such a laminated film is used as a film for high retort packaging, usually, the layer made of the propylene resin composition of the present invention serves as a food contact side and acts as a heat-sealed sealant layer.

The method for producing the laminated film of the present invention is not particularly limited as described above, and a known method can be employed. For example, as a manufacturing method in the case of laminating a film made of the propylene resin composition of the present invention and another film or a laminated film, for example, an anchor coating agent based on urethane or isocyanate on one surface Is applied, and the other is stacked on top of the dry laminate, or the propylene resin composition of the present invention is directly extruded and laminated on the film or laminated film on which the layer made of the propylene resin composition of the present invention is laminated. The method of extrusion coating, etc. are mentioned. In addition, when the layer on which the layer made of the propylene-based resin composition of the present invention is laminated is formed of a thermoplastic resin, it may be formed into a laminated film directly from both resins by coextrusion.

When the laminated film of the present invention thus obtained is used as a packaging material, the heat-sealing strength (peeling strength of the heat-sealing portion) of the layer made of the propylene-based resin composition of the present invention is high, and high temperature and high pressure are performed. High heat sealing strength is maintained even after heat treatment such as retort sterilization treatment.

In the laminated film of the present invention, a heat sealing layer having properties such as heat resistance, impact resistance at low temperatures, high heat sealing strength, and rigidity is formed on the surface, and depending on the type of the base layer, high gas barrier properties or mechanical properties are provided. Since strength is additionally imparted, it can be used in a wide range of applications including retort food packaging. In addition, this laminated film may be used in the form of a film, or may be used as a packaging material after changing to the shape of a tray or container.

<Retort Pouch>

The retort pouch of the present invention comprises, among the laminated films described above, a layer made of the propylene resin composition according to the present invention as a surface layer on one side. The retort pouch of the present invention is a package for the purpose of long-term storage by filling contents such as food and sterilizing retort at high temperature, and the present invention is among the laminated films forming the same in the form of an object or the like. The layer made of the propylene-based resin composition thus becomes a heat sealing layer (sealing layer) and a surface in contact with contents such as food. The laminated film constituting such a retort pouch preferably has a barrier layer and a base layer in addition to a layer made of a propylene-based resin composition, and further preferably has an impact absorbing layer or the like. The retort pouch of the present invention has heat resistance, impact resistance at low temperatures, heat sealing strength, rigidity, gas barrier properties, etc., is suitable for high retort sterilization at high temperatures, and has a high heat sealing strength even after high temperature sterilization. , It has excellent long-term preservation.

Example

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

In Examples and Comparative Examples, various physical properties were measured or evaluated by the following methods.

(1) Melt flow rate (MFR)

In accordance with ASTM D-1238, the propylene polymer (propylene-ethylene block copolymer) was measured at 230°C under a load of 2.16 kg, and the ethylene polymer (ethylene-α-olefin copolymer) was measured at 190°C under a load of 2.16 kg. .

(2) Pentard isotactic fraction (mmmm fraction)

The pentad isotactic fraction (mmmm fraction) of the sample (propylene homopolymer) was measured using ¹³ C-NMR under the following conditions based on the attribution shown in Macromolecules, 8, 687 (1975) by A. zambelli et al. Then, it was set as the pentad isotactic fraction = (peak area at 21.7 ppm)/(peak area at 19 to 23 ppm).

(3) Paraxylene soluble component, insoluble component

The ratio of the paraxylene-insoluble component is to the boiling temperature by adding 5 g of a sample and 1 g of 2,6-di-tert-butyl-4-methylphenol (BHT) as an antioxidant to 700 ml of paraxylene, and stirring while heating. After heating up and completely dissolving, it was allowed to cool for 8 hours or more until it reached 25°C while stirring, and the precipitated component was filtered through a filter paper and taken, and this is a value calculated as an insoluble component. The ratio of the paraxylene-soluble component was taken as a value obtained by subtracting the value of the insoluble component from the total amount of the sample.

(4) n-decane soluble component

200 ml of n-decane was added to 5 g of the sample, and it was heated and dissolved at 145°C for 30 minutes. It cooled to 20 degreeC over about 3 hours, and left to stand for 30 minutes. Then, the precipitate (hereinafter, n-decane insoluble component) was separated by filtration. The filtrate was put in about 3 times the amount of acetone to precipitate a component dissolved in n-decane (precipitate (A)). The precipitate (A) and acetone were separated by filtration, and the precipitate was dried. On the other hand, even if the filtrate side was concentrated to dryness, no residue was observed.

The amount of n-decane soluble component was calculated|required by the following formula.

n-decane soluble parts (mass%) = [precipitate (A) mass/sample mass] × 100

(5) Content of structural units derived from ethylene

The content of the structural unit derived from ethylene in the paraxylene-soluble component of the propylene-ethylene block copolymer (A) is 1,2,4-trichlorobenzene/heavy benzene (2:1) solution 0.6 After dissolving in ml, carbon nuclear magnetic resonance analysis ( ¹³ C-NMR) was performed, and propylene, ethylene, and α-olefin were determined by quantification by diamond chain distribution.

For example, in the case of a propylene-ethylene copolymer,

PP=Sαα, EP=Sαγ+Sαβ, EE=1/2(Sβδ+Sδδ)+1/4Sγδ

It was calculated|required by the following calculation formulas (Eq-1) and (Eq-2) using.

Propylene (mol%)=(PP+1/2EP)×100/[(PP+1/2EP)+(1/2EP+EE)]… (Eq-1)

Ethylene (mol%) = (1/2EP+EE)×100/[(PP+1/2EP)+(1/2EP+EE)]… (Eq-2)

(6) Intrinsic viscosity [η]

It measured at 135 degreeC using a decalin solvent. About 20 mg of a sample was dissolved in 15 ml of decalin, and the specific viscosity ηsp was measured in an oil bath at 135°C. To this decalin solution, 5 ml of decalin solvent was added and diluted, and then the specific viscosity ηsp was measured in the same manner. This dilution operation was further repeated twice, and the value of ηsp/C when the concentration (C) was extrapolated to 0 was determined as the intrinsic viscosity.

[Η] = lim(ηsp/C) (C→0)

(7) film transparency (haze value)

It measured according to JIS K 7105.

(8) film blocking strength

The coating roll surfaces of the film of 10 cm in the MD direction x 10 cm in the TD direction are overlapped, and held in a thermostat at 80°C under a load of 200 g/cm ² for 3 days.

Thereafter, the condition was adjusted in a room at 23°C and 50% humidity for 24 hours or more, and then the peel strength when peeled at a tensile speed of 200 mm/min was measured, and the peel strength was divided by the width of the test piece (mN/cm). It was made into the blocking coefficient and the blocking resistance was evaluated. Here, the smaller the blocking coefficient is, the better the blocking resistance is.

(9) Tensile modulus (MD) of the film

According to JIS K7127, it measured under the conditions of crosshead speed: 500 mm/min, measurement direction: machine direction (MD direction), and load cell: 10 kg by a tensile tester.

(10) Impact resistance (film impact)

After conditioning the sample at a predetermined temperature (-20°C) of ±2°C and humidity of 50 ±10% for 16 hours or more, under the same temperature and humidity conditions, in a film impact tester manufactured by Toyo Seiki, 1/2 It evaluated by the impact fracture strength using an inch impact head.

(11) Heat sealing strength of laminated film

Using a heat seal tester manufactured by Toyo Seiki, a test piece of 100 mm width and 150 mm length was cut out from the laminated film, folded in half, and under the conditions of a predetermined heater temperature (200°C or 220°C), pressure of 0.2 MPa, and sealing time of 1 second. , After performing heat sealing, the sealed test piece was cut out into a test piece having a width of 15 mm, and the peel strength (N/15 mm) was measured using a Tensilon RT1225 type manufactured by Orientech, and it was set as the heat sealing strength before retort sterilization.

In addition, the test piece prepared by the above method was put in a hot water shower type high-pressure high-temperature sterilization apparatus, treated at 121°C for 30 minutes, and then cooled, the peel strength (N/15mm) was measured by the same method as above. Then, it was set as the heat sealing strength after retort sterilization.

(12) Fall test

Using a laminated film, a three-way sealed bag having a length of 175 mm and a horizontal direction of 125 mm was prepared using a woven machine. On the other hand, the sealing width is 10 mm. The prepared three-way sealed bag was filled with 200 ml of water, air was removed, and then the mouth part was sealed.

Twenty such bags were prepared and left to stand in an atmosphere of 5°C for 24 hours, and then, from a height of 10 cm, the horizontal direction was the fall direction, and a weight of 1300 g of the same size as the bag size was added to each bag. The number of times to the bag was counted by repeating the fall from the set as one set, and repeating the fall from the 20 sets as the upper limit. The number of times of bagging of 20 prepared bags was averaged, and the average value was taken as the average number of baggings.

[Production Example 1]

(Production of propylene-ethylene block copolymer (A-1))

(1) Preparation of solid titanium catalyst component

95.2 g of anhydrous magnesium chloride, 442 ml of decane, and 390.6 g of 2-ethylhexyl alcohol were heated at 130° C. for 2 hours to obtain a homogeneous solution, and then 21.3 g of phthalic anhydride was added to the solution, followed by 1 at 130° C. Stirring and mixing was performed over time, and phthalic anhydride was dissolved.

After cooling the thus-obtained homogeneous solution to room temperature, 75 ml of this homogeneous solution was added dropwise to 200 ml of titanium tetrachloride maintained at -20°C over 1 hour. After completion of charging, the temperature of this mixed solution was raised to 110°C over 4 hours, and when reaching 110°C, 5.22 g of diisobutyl phthalate (DIBP) was added, and the mixture was stirred and maintained at the same temperature for 2 hours.

After the completion of the reaction for 2 hours, the solid part was collected by thermal filtration, the solid part was resuspended in 275 ml of titanium tetrachloride, and then heated again at 110° C. for 2 hours. After completion of the reaction, the solid part was collected by heat filtration again, and sufficiently washed with decane and hexane at 110° C. until no free titanium compound was detected in the solution.

The solid titanium catalyst component prepared as described above was preserved as a hexane slurry, but part of it was dried to investigate the catalyst composition. The solid titanium catalyst component contained 2.3 mass% of titanium, 61 mass% of chlorine, 19 mass% of magnesium, and 12.5 mass% of DIBP.

(2) Preparation of pre-polymerization catalyst

87.5 g of the solid titanium catalyst component prepared in (1), 19.5 mL of triethylaluminum, and 10 L of heptane were charged into an autoclave by adding a stirrer with an inner volume of 20 L, maintained at an internal temperature of 15 to 20°C, charged with 263 g of propylene, and stirred for 100 minutes. While reacting. After the polymerization was completed, the solid component was precipitated, the supernatant was removed, and washing with heptane was performed twice. The obtained prepolymerization catalyst was resuspended in purified heptane and adjusted with heptane to obtain a solid catalyst component concentration of 0.7 g/L to obtain a catalyst slurry.

(3) Main polymerization

In a vessel polymerization reactor with an inner volume of 58 L with a stirrer, 30 kg/hour of propylene, 40 NL/hour of hydrogen, 0.44 g/hour of the catalyst slurry prepared in (2) as a transition metal catalyst component, 4.9 mL/hour of triethylaluminum, die 1.6 mL/hour of cyclopentyldimethoxysilane was continuously supplied, and polymerization was carried out in a full liquid state in which no gas phase was present. The temperature of the tubular polymerization reactor was 70°C, and the pressure was 3.3 MPa/G (G = gauge pressure).

The resulting slurry was sent to a vessel polymerizer with an inner volume of 70 L equipped with a stirrer, and further polymerized. To the polymerization reactor, propylene was supplied at 15 kg/hour and hydrogen was supplied so that the hydrogen concentration in the gaseous phase became 1.5 mol%. The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 3.0 MPa/G.

The resulting slurry was transferred to a transfer tube with an inner volume of 2.4 L, the slurry was gasified, and separated by vaporization, and then a polypropylene homopolymer powder was sent to a gas phase polymerization reactor with an inner volume of 480 L, and ethylene/propylene block copolymerization was performed. . Propylene, ethylene, and hydrogen were continuously supplied so that the gas composition in the gas phase polymerization reactor was ethylene/(ethylene+propylene) = 0.20 (molar ratio) and hydrogen/ethylene = 0.078 (molar ratio). The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 1.0 MPa/G.

The resulting slurry was deactivated and vaporized, followed by vapor separation, and vacuum drying at 80°C. Thereby, a propylene/ethylene block copolymer (A-1) having a polypropylene portion and an ethylene/propylene copolymer portion was obtained.

Table 1 shows the physical properties of the obtained propylene-ethylene block copolymer (A-1).

(Production and evaluation of single layer film)

Using the obtained propylene-ethylene block copolymer (A-1), and using a single-layer CPP tester (made by Mitsubishi Heavy Industries, φ75mm) as a film forming machine, resin temperature setting: 250°C, chill roll temperature setting: 40°C, air gap Length: Under conditions of about 80 mm and a film forming speed of 40 m/min, a film having a film thickness of 70 μm was extruded, left standing at 40° C. for 24 hours, and aging was performed to obtain a single layer film. About the obtained single-layer film, transparency (haze value), blocking strength, and tensile modulus were measured by the method mentioned above. The result is combined with Table 1 and shown.

(Production and evaluation of laminated film)

From the outer surface, a polyethylene terephthalate film (12 μm)/aluminum foil (7 μm)/a single layer film (70 μm) obtained above is constructed, and a high retort CPP dry-rami adhesive (polyester polyol-based, solid content 35%) is interlayered. By using, dry lamination was carried out under conditions of a line speed of 80 m/min, and aging was performed at 40° C. for 5 days for the effect of an adhesive to obtain a laminated film.

Using the obtained laminated film, evaluation of heat sealing strength and falling body test were performed by the method mentioned above. The result is combined with Table 1 and shown.

[Production Example 2]

(Production of propylene/ethylene block copolymer (A-2))

(1) Preparation of solid titanium catalyst component

95.2 g of anhydrous magnesium chloride, 442 ml of decane, and 390.6 g of 2-ethylhexyl alcohol were heated at 130° C. for 2 hours to obtain a homogeneous solution, and then 21.3 g of phthalic anhydride was added to the solution, followed by 1 at 130° C. Stirring and mixing was performed over time, and phthalic anhydride was dissolved.

After cooling the thus-obtained homogeneous solution to room temperature, 75 ml of this homogeneous solution was added dropwise to 200 ml of titanium tetrachloride maintained at -20°C over 1 hour. After completion of charging, the temperature of this mixed solution was raised to 110°C over 4 hours, and when reaching 110°C, 5.22 g of diisobutyl phthalate (DIBP) was added, and the mixture was stirred and maintained at the same temperature for 2 hours.

After the completion of the reaction for 2 hours, the solid part was collected by thermal filtration, the solid part was resuspended in 275 ml of titanium tetrachloride, and then heated again at 110° C. for 2 hours. After completion of the reaction, the solid part was collected by heat filtration again, and sufficiently washed with decane and hexane at 110° C. until no free titanium compound was detected in the solution.

The solid titanium catalyst component prepared as described above was preserved as a hexane slurry, but part of it was dried to investigate the catalyst composition. The solid titanium catalyst component contained 2.3% by weight of titanium, 61% by weight of chlorine, 19% by weight of magnesium, and 12.5% by weight of DIBP.

(2) Preparation of prepolymerization catalyst

Solid catalyst component 100g, triethylaluminum 91.2mL, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane 30.8ml, heptane 10L was inserted into an autoclave with an inner volume of 20L stirrer, and internal temperature 15 The temperature was maintained at -20°C, and 1000 g of propylene was inserted, followed by reaction with stirring for 100 minutes. After the polymerization was completed, the solid component was precipitated, the supernatant was removed, and washing with heptane was performed twice. The obtained prepolymerization catalyst was resuspended in purified heptane, and it was adjusted with heptane so that the concentration of the solid catalyst component was 0.75 g/L.

(3) Main polymerization

In a 58L agitator-added vessel polymerization reactor, 30 kg/hour of propylene, 27 NL/hour of hydrogen, 0.33 g/hour of the catalyst slurry prepared in (2) as a transition metal catalyst component, 2.9 mL/hour of triethylaluminum, die Cyclopentyldimethoxysilane 0.76 mL/hour was continuously supplied, and polymerization was carried out in a full liquid state in which no gas phase was present. The temperature of the tubular polymerization reactor was 70°C and the pressure was 3.3 MPa/G.

The resulting slurry was sent to a vessel polymerizer with an inner volume of 70 L equipped with a stirrer, and further polymerized. To the polymerization reactor, propylene was supplied at 15 kg/hour and hydrogen was supplied so that the hydrogen concentration in the gaseous phase was 2.2 mol%. The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 3.0 MPa/G.

The resulting slurry was transferred to a transfer tube with an inner volume of 2.4 L, the slurry was gasified and separated from the vapor phase, and then the polypropylene homopolymer powder was sent to a gas phase polymerizer with an inner volume of 480 L, and ethylene/propylene block copolymerization was performed. Propylene, ethylene, and hydrogen were continuously supplied so that the gas composition in the gas phase polymerization reactor was ethylene/(ethylene+propylene) = 0.1965 (molar ratio) and hydrogen/ethylene = 0.1296 (molar ratio). The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 1.1 MPa/G.

The resulting slurry was deactivated and vaporized, followed by vapor separation, and vacuum drying at 80°C. Thereby, a propylene/ethylene block copolymer (A-2) having a polypropylene portion and an ethylene/propylene copolymer portion was obtained.

Table 1 shows the physical properties of the obtained propylene-ethylene block copolymer (A-2) and the evaluation results of the single-layer film and the laminated film prepared in the same manner as in Production Example 1 using the same.

[Production Example 3]

(Production of propylene-ethylene block copolymer (A'-3))

(1) Preparation of a solid titanium catalyst component, and (2) preparation of a prepolymerization catalyst were carried out in the same manner as in Production Example 2.

(3) Main polymerization

In a 58L agitator-added vessel polymerization reactor, 30 kg/hour of propylene, 27 NL/hour of hydrogen, 0.33 g/hour of the catalyst slurry prepared in (2) as a transition metal catalyst component, 2.9 mL/hour of triethylaluminum, die Cyclopentyldimethoxysilane 0.76 mL/hour was continuously supplied, and polymerization was carried out in a full liquid state in which no gas phase was present. The temperature of the tubular polymerization reactor was 70°C and the pressure was 3.3 MPa/G.

The resulting slurry was sent to a vessel polymerizer with an inner volume of 70 L equipped with a stirrer, and further polymerized. To the polymerization reactor, propylene was supplied at 15 kg/hour and hydrogen was supplied so that the hydrogen concentration in the gaseous phase was 2.2 mol%. The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 3.0 MPa/G.

The resulting slurry was transferred to a transfer tube with an inner volume of 2.4 L, the slurry was gasified and separated from the vapor phase, and then the polypropylene homopolymer powder was sent to a gas phase polymerizer with an inner volume of 480 L, and ethylene/propylene block copolymerization was performed. Propylene, ethylene, and hydrogen were continuously supplied so that the gas composition in the gas phase polymerization reactor was ethylene/(ethylene+propylene) = 0.3175 (molar ratio) and hydrogen/ethylene = 0.1283 (molar ratio). The polymerization was carried out at a polymerization temperature of 70°C and a pressure of 1.1 MPa/G.

The resulting slurry was deactivated and vaporized, followed by vapor separation, and vacuum drying at 80°C. Thereby, a propylene/ethylene block copolymer (A'-3) having a polypropylene part and an ethylene/propylene copolymer part was obtained.

Table 1 shows the physical properties of the obtained propylene-ethylene block copolymer (A'-3) and the evaluation results of the properties of the single-layer film and the laminated film prepared in the same manner as in Production Example 1 using the same.

[Production Example 4]

(Production of propylene-ethylene block copolymer (A'-4))

(1) Preparation of magnesium compound

When there is no generation of hydrogen gas from the inside of the system under reflux conditions after sufficiently replacing the reaction tank with an inner volume of 500 liters with nitrogen gas, adding 97.2 kg of ethanol, 640 g of iodine and 6.4 kg of metallic magnesium, and stirring To obtain a solid reaction product. The desired magnesium compound (solid product) was obtained by drying the reaction liquid containing this solid reaction product under reduced pressure.

(2) Preparation of solid catalyst component

To a 500 L stirrer addition reaction tank with an inner volume of 500 L sufficiently substituted with nitrogen gas, 30 kg of the magnesium compound (not pulverized) obtained in (1) above, 150 liters of purified heptane, 4.5 liters of silicon tetrachloride, and 4.3 liters of diethyl phthalate were added. I put it in. The inside of the system was kept at 90° C., and 144 liters of titanium tetrachloride were added while stirring, and the mixture was reacted at 110° C. for 2 hours, and the solid component was separated and washed with purified heptane at 80° C. Further, 228 liters of titanium tetrachloride was added and reacted at 110°C for 2 hours, followed by washing sufficiently with purified heptane to obtain a solid catalyst component.

(3) Prepolymerization

230 liters of purified heptane was added to the addition reaction tank of a stirrer having an inner volume of 500 liters, and further 25 kg of the solid catalyst component obtained in (2) was added, and then, for 1 mol of Ti atoms in the solid catalyst component, tri After adding ethyl aluminum at a ratio of 0.6 mol and cyclohexylmethyldimethoxysilane at a ratio of 0.4 mol, propylene was introduced at a partial pressure of propylene until 0.3 kg/cm ² G, and reacted at 25° C. for 4 hours. After completion of the reaction, the solid catalyst component was washed several times with purified heptane, and carbon dioxide was supplied, followed by stirring for 24 hours.

(4) Main polymerization

As the polymerization front end, in the agitator addition polymerization apparatus (R-1) having an inner volume of 200 L, the solid catalyst component treated in (3) is 3 mmol/hr in terms of Ti atoms, and triethylaluminum is 413 mmol/hr ( 7.5 mmol/kg-PP), cyclohexylmethyldimethoxysilane was supplied at 105 mmol/hr (1.9 mmol/kg-PP), respectively, and propylene gas containing 0.07 mol% of hydrogen was supplied to the polymerization temperature. Propylene was polymerized at 75° C. and a total pressure of 30 kg/cm ² G.

Then, powder was continuously extracted from R-1, and it was transferred to an agitator addition polymerization apparatus (R-2) having an internal volume of 200 L. In (R-2), propylene, ethylene and hydrogen were supplied in a gas composition in a ratio of propylene: 81.4 mol%, ethylene: 14.5 mol%, hydrogen: 4.1 mol%, polymerization temperature 50°C, total pressure 11 kg/cm ^{At 2} G, propylene and ethylene were copolymerized.

A propylene-ethylene block copolymer (A'-4) was obtained by such a polymerization method.

Table 1 shows the physical properties of the obtained propylene-ethylene block copolymer (A'-4) and the evaluation results of the single-layer film and the laminated film prepared in the same manner as in Production Example 1 using the same.

[Example 1]

(Production of propylene resin composition (1))

80 parts by mass of the propylene-ethylene block copolymer (A-1) obtained in Production Example 1, and the ethylene-α-olefin copolymer (B-1) as an ethylene-hexene-1 copolymer (manufactured by Prime Polymer Co., Ltd., brand name: Evolu (registered trademark) SP0510, MFR: 1.2 g/10 min, density 904 kg/m ³ , n-decane soluble component 2.3 mass%) 20 parts by weight) and kneaded and assembled with a twin-screw kneader. , A propylene-based resin composition (1) was obtained.

Using the obtained propylene-based resin composition (1), using a single-layer CPP tester (made by Mitsubishi Hollow, φ75mm) as a film forming machine, resin temperature setting: 250°C, chill roll temperature setting: 40°C, air gap length: about 80mm , Under the conditions of a film forming speed of 40 m/min, a film having a film thickness of 70 μm was extrusion-molded, left standing at 40° C. for 24 hours to perform aging to obtain a single layer film. About the obtained single-layer film, transparency (haze value), blocking strength, and tensile modulus were measured by the method mentioned above. The results are shown in Table 2.

(Production and evaluation of laminated film)

From the outer surface, a polyethylene terephthalate film (12 μm)/aluminum foil (7 μm)/a single layer film (70 μm) obtained above is constructed, and a high retort CPP dry-rami adhesive (polyester polyol-based, solid content 35%) is interlayered. By using, dry lamination was carried out under conditions of a line speed of 80 m/min, and aging was performed at 40° C. for 5 days for the effect of an adhesive to obtain a laminated film.

Using the obtained laminated film, evaluation of the heat-sealing strength at a heat-sealing temperature of 200°C and 220°C, and a drop test were performed by the method described above. The result is combined with Table 2 and shown.

[Example 2]

In Example 1, in place of the propylene-ethylene block copolymer (A-1), except that the propylene-ethylene block copolymer (A-2) obtained in Production Example 2 was used, in the same manner as in Example 1, propylene-based A resin composition, a single layer film, and a laminated film were produced, and each property was evaluated. The results are shown in Table 2.

[Example 3]

In Example 2, the blending amount of the propylene-ethylene block copolymer (A-2) and the ethylene-α-olefin copolymer (B-1) was 90 parts by mass of the propylene-ethylene block copolymer (A-2), A propylene-based resin composition, a single-layer film, and a laminated film were produced in the same manner as in Example 2, except for changing to 10 parts by mass of the ethylene/α-olefin copolymer (B-1), and each property was evaluated. The results are shown in Table 2.

[Comparative Example 1]

In Example 1, in the same manner as in Example 1, except that the propylene-ethylene block copolymer (A'-3) obtained in Production Example 3 was used instead of the propylene-ethylene block copolymer (A-1), The system resin composition, a single layer film, and a laminated film were produced, and each property was evaluated. The results are shown in Table 2.

[Comparative Example 2]

In Comparative Example 1, the blending amount of the propylene/ethylene block copolymer (A'-3) and the ethylene/α-olefin copolymer (B-1) was 90 mass of the propylene/ethylene block copolymer (A'-3). Parts, except having changed to 10 parts by mass of ethylene/α-olefin copolymer (B-1), were carried out in the same manner as in Comparative Example 1 to produce a propylene-based resin composition, a single layer film, and a laminated film, and each property was evaluated. The results are shown in Table 2.

[Comparative Example 3]

In Comparative Example 1, in place of the ethylene/α-olefin copolymer (B-1), ethylene/hexene having an MFR of 4 g/10 min, a density of 918 kg/m ³ , and an n-decane soluble component amount of 0.5 mass% 1 In the same manner as in Comparative Example 1, except for using the copolymer ethylene/α-olefin copolymer (B-2) (manufactured by Prime Polymer Co., Ltd., brand name: Evol (registered trademark) SP2040), a propylene resin composition, A single layer film and a laminated film were produced, and each property was evaluated. The results are shown in Table 2.

[Comparative Example 4]

In Example 3, in place of the ethylene/α-olefin copolymer (B-1), an ethylene/α-olefin copolymer (B-3) having an MFR of 0.5 g/10 min and a density of 885 kg/m ³ (Mitsui Chemical Co., Ltd. product, brand name: Tafmer (registered trademark) A0585) was carried out in the same manner as in Example 3 to prepare a propylene resin composition, a single layer film, and a laminated film, and each property was evaluated. The results are shown in Table 2.

[Comparative Example 5]

In Comparative Example 1, instead of the ethylene/α-olefin copolymer (B-1), an ethylene/α-olefin copolymer having an MFR of 4.0, a density of 911 kg/m ³ , and an n-decane soluble component amount of 3.3% by mass Except having used (B-4) (Ultzex 1540L made by Prime Polymer), in the same manner as in Comparative Example 1, a propylene-based resin composition, a single layer film, and a laminated film were produced, and each property was evaluated. The results are shown in Table 2.

The propylene resin composition of the present invention is suitable for the production of a film or laminated film having excellent high heat sealing properties, heat resistance, and impact resistance at low temperatures, and the film is suitable for use in packaging that involves high retort high temperature sterilization. Thus, it can be suitably used for applications such as packaging films, retort pouches, and retort containers.

Claims (7)

75 to 95 mass% of propylene-ethylene block copolymer (A) satisfying the following requirements (a-1) to (a-4),
A propylene-based resin composition comprising 5 to 25% by mass of an ethylene/α-olefin copolymer (B) satisfying the following requirements (b-1) and (b-2).
(a-1) The melt flow rate (230°C, 2.16 kg load) is 2.0 to 8.0 g/10 minutes.
(a-2) The amount of the paraxylene-soluble component is 15% by mass or more, and the amount of the paraxylene-soluble component (mass%) and the amount of the n-decane-soluble component (mass%) satisfy the following relational expression (1).
n-decane soluble component amount ≤ paraxylene soluble component amount × 0.95. (One)
(a-3) The content of the structural unit derived from ethylene in the paraxylene-soluble component is 20 to 30 mass%.
(a-4) In the paraxylene insoluble component, the pentad isotactic fraction is 94 mol% or more.
(b-1) Melt flow rate (190°C, 2.16 kg load) is 0.5 to 5.0 g/10 minutes.
(b-2) The density is 890kg/m ³ ∼910kg/m ³ . The method of claim 1,
The propylene-based resin composition, wherein the ethylene/α-olefin copolymer (B) further satisfies the requirement (b-3).
(b-3) The density X (kg/m ³ ) and the n-decane soluble component amount Y (mass %) satisfy the following relational expression (2).
Y≤0.0046X ² -8.578X+4000… (2) A film comprising the propylene-based resin composition according to claim 1 or 2. The method of claim 3,
Film, characterized in that the non-stretched film. A laminated film comprising a layer made of the propylene-based resin composition according to claim 1 or 2. The method of claim 5,
A laminated film comprising a layer made of the propylene resin composition according to claim 1 or 2 as a surface layer on one side. A retort pouch comprising the laminated film according to claim 6.