JP2014214235A - Propylene polymer composition and thermal-fusion film, laminate and package composed of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propylene polymer composition which is excellent in blocking resistance and heat seal strength, causes less deterioration of the heat seal strength even after heat treatment and has low-temperature impact resistance and a thermal-fusion laminate film using the composition.SOLUTION: A propylene polymer composition consists of a propylene polymer ingredient (A), a propylene-α-olefin random copolymer ingredient (B) and a random copolymer ingredient (C) of ethylene and a 4C or higher α-olefin. A thermal-fusion film and a laminate containing the composition are also provided.

Description

  The present invention uses a propylene polymer composition, a heat-fusible film suitably used as a packaging material for an article to be packaged such as a retort food made of the composition, and the heat-fusible film as a heat-fusible layer. The present invention relates to a laminated film and a package in which an article to be packaged that requires heating and sterilization treatment is packaged using the laminated film. In addition, heavy food applications that do not require heating and sterilization treatment, medical packaging such as infusion bags and blood bags that require heating and sterilization treatment, packaging bags for storing electronic parts, etc., base film for adhesive processing for protective films As a material for interior materials such as automobile ceiling materials, it is used in many fields.

  The food culture has diversified due to the effects of social changes such as an aging population, a nuclear family, an increase in the number of single employees, or an increase in the working generation, and the aging of the marriage age, etc. The demand for convenience is increasing. So, after putting the cooked food in a bag and sealing it, purchase so-called retort food that has been pressurized and heat sterilized, and put the retort food in a bag and heat it when necessary. Opportunities for taking out and serving meals are increasing. Such retort food has spread and expanded not only for home use but also for business use, and Japanese food culture has expanded to Asia, North America and the West. Therefore, a packaging material capable of packaging a large amount of food at a time is required.

  Retort food is generally stored at room temperature for a long period of time. In some cases, the film used for the packaging material is required to have high heat seal strength and low temperature impact resistance so as not to be damaged from the heat seal portion of the package. At the same time, after filling and sealing the food, the retort food is heated at a high temperature in a short time, for example, from about 100 ° C. to about 130 ° C. for about 30 minutes to 60 minutes, sometimes about 130 to 140 ° C. for about several minutes to about 10 minutes. -Since the retort sterilization process is performed using a high-pressure kettle, heat resistance of the heat seal part that can withstand the process is required. In order to preserve the strength of the bag in order to protect the contents such as transportation of food and dropping from the display stand, a strong heat seal strength is also required from the aspect of food quality control.

  Conventionally used films for this purpose include films made from blends of polypropylene and ethylene / α-olefin copolymer rubber, films made from polypropylene block copolymers, or polypropylene block copolymers thereof. It was a film produced from a blend with an ethylene / α-olefin copolymer rubber. Although they are excellent in heat resistance and low temperature impact strength, the balance between low temperature impact strength and blocking resistance is still insufficient, and heat seal strength tends to decrease after retorting. .

  Therefore, in order to prevent any decrease in heat seal strength after retorting, for example, a propylene / α-olefin block copolymer composed of 95 to 70% by weight of polypropylene block units and 5 to 30% by weight of elastomer block units is used. It has been proposed to use coalescence for the heat seal layer (Japanese Patent Laid-Open No. 2000-255012: Patent Document 1). However, a film formed from a propylene / α-olefin block copolymer containing an elastomer block unit having a propylene content of 30 to 70 mol% specifically described in Patent Document 1 has sufficient low-temperature impact strength. In addition, the seal strength tended to decrease after retorting. In addition, unevenness (so-called cocoon skin) is likely to occur on the surface of the package, which is a cause of poor appearance.

  Further, in order to improve the low temperature impact resistance, heat seal strength, heat resistance, etc. of the retort film, propylene having an intrinsic viscosity [η] of the p-xylene soluble part of 1.5 to 2.8 (dl / g). A composition in which 1 to 10% by weight of ethylene / α-olefin copolymer rubber is added to 90 to 99% by weight of an ethylene block copolymer (Japanese Patent Laid-Open No. 2000-119480: Patent Document 2) has been proposed. Although the film obtained from such a composition has improved low-temperature impact resistance, the blocking resistance is not good, and it is difficult to say that the effect of suppressing the reduction in seal strength after retort treatment is sufficient.

Furthermore, it has rigidity and low-temperature impact resistance, has excellent blocking resistance and heat seal strength, has a small decrease in heat seal strength even after heat treatment, and prevents or reduces the occurrence of irregularities on the surface of the package. As a heat-fusible laminated film using a fusible film, a propylene polymer component (A), a propylene / α-olefin random copolymer component (B) containing 70 to 85% by weight of propylene units, and ethylene and carbon The melt flow rate (230 ° C.) is 2 to 10 (g / 10 minutes), and the ethylene unit content is 10 to 10, comprising a random copolymer component (C) with an α-olefin of 4 or more. A method using a heat-fusible film made of a propylene polymer composition of 20% by weight (Patent No. 3905006: Patent Document 3) has been proposed.
However, it has been found that even when the proposed composition is used, the improvement in blocking resistance may still be insufficient.

JP 2000-255012 A JP 2000-119480 A Japanese Patent No. 3905006

  An object of the present invention is a propylene polymer composition suitable for obtaining a heat-fusible film having excellent blocking resistance and heat-sealing strength, having a small decrease in heat-sealing strength even after heat treatment, and having low-temperature impact resistance. And a heat-fusible laminated film using the composition.

The present invention comprises a propylene polymer component (A), a propylene / α-olefin random copolymer component (B), and a random copolymer component (C) of ethylene and an α-olefin having 4 or more carbon atoms. A polymer composition comprising:
(1) Propylene polymer component (A) and propylene / α-olefin random copolymer component (B) have a weight ratio represented by (A) / (B) in the range of 80/20 to 95/5. There,
(2) The propylene / α-olefin random copolymer component (B) has an intrinsic viscosity [η] in the range of 2 to 3.8 dl / g, and the propylene unit content exceeds 50 wt% and is 70 wt%. % Range,
(3) The ethylene / α-olefin random copolymer component (C) has a density of 0.865 to 0.910 g / cm ³ and occupies 2 to 15% by weight in the composition.
(4) The melt flow rate (230 ° C.) of the propylene polymer composition is 2 to 10 (g / 10 minutes), and the ethylene unit content is in the range of 5 to 15% by weight. A propylene polymer composition, and a heat-fusible film comprising the composition.

  The heat-fusible film obtained from the propylene polymer composition of the present invention is excellent in blocking resistance and heat seal strength, has a small decrease in heat seal strength even after heat treatment, and has low temperature impact resistance.

<Propylene polymer component (A)>
The propylene polymer component (A) which is the main component of the propylene polymer composition of the present invention is a propylene homopolymer or a copolymer of propylene and 10 wt% or less, preferably 5 wt% or less α-olefin. It is a coalescence. The α-olefin is an α-olefin having 2 to 10 carbon atoms other than propylene, such as ethylene, 1-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, Examples include 4-methyl-1-pentene, 1-hexene, and 1-octene. Among these polymers, a propylene homopolymer is preferably used because a film having excellent heat resistance can be obtained.
Two or more of the propylene polymer components (A) according to the present invention may be used.
In the propylene polymer component (A) according to the present invention, the intrinsic viscosity [η] measured at 135 ° C. in a decalin solvent is usually 1.5 to 2.5 dl / g, preferably 1.8 to 2. It is in the range of 3 dl / g.

<Propylene / α-olefin random copolymer component (B)>
The propylene / α-olefin random copolymer (B) which is one of the components of the propylene polymer composition of the present invention is a copolymer of propylene and the same α-olefin having 2 to 10 carbon atoms other than propylene as described above. It is a polymer and has elastomeric properties. As the α-olefin, ethylene is particularly preferable.
The propylene / α-olefin random copolymer component (B) according to the present invention has a propylene unit content of more than 50% by weight and less than 70% by weight, preferably 58 to 68% by weight, and an α-olefin unit content. Is more than 30% by weight and less than 50% by weight, preferably 32 to 42% by weight. When the content of the propylene unit is in the above range, a film having excellent low-temperature impact strength and low-temperature heat-sealing property and having high sealing strength after heat treatment is formed from the composition containing the copolymer component. be able to. In addition, content of a propylene unit can be measured by infrared absorption spectrum analysis.

The proportion of the copolymer (B) in the propylene polymer composition was determined by dissolving the composition sample (a: gram) in decane and then leaving it at 23 ° C. for 24 hours, and then separating the precipitate ( b: gram) can be separated, and the decane soluble part in the sample can be calculated as a copolymer (B) by the following formula.
Ratio of copolymer (B) = {(ab) / a} × 100 (% by weight)
The intrinsic viscosity [η] of the propylene / α-olefin random copolymer component (B) according to the present invention is 2 to 3.8 dl / g, preferably 2.5 to 3.7 dl / g. When the intrinsic viscosity [η] is in the above range, a film excellent in blocking resistance can be produced from a composition containing the intrinsic viscosity while suppressing the generation of fish eyes.
The intrinsic viscosity [η] is obtained from the viscosity measured at 135 ° C. in a decalin solvent for the collected precipitate by adding excess acetone to the decane-soluble portion separated by the above-described fractionation operation to precipitate the dissolved product. be able to.
Two or more of the propylene / α-olefin random copolymer component (B) according to the present invention may be used.

<Ethylene / α-olefin random copolymer component>
The ethylene / α-olefin random copolymer (C) which is one of the components of the propylene polymer composition of the present invention is a random copolymer of ethylene and an α-olefin having 4 or more carbon atoms, preferably 4 to 10 carbon atoms. It is a coalescence. Specific examples of α-olefins include 1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-tetradecene and 1-octadecene. Can do. Among these, 1-butene, 1-hexene, and 1-octene are particularly preferable. These α-olefins may be contained alone or in combination of two or more. Further, it may be a mixture of different ethylene / α-olefin random copolymers.
Specific examples of the preferred copolymer (C) include an ethylene / 1-butene random copolymer, an ethylene / 1-hexene random copolymer, and an ethylene / 1-octene random copolymer.

The density of the copolymer (C) is 0.865 to 0.910 g / cm ³ , preferably 0.875 to 0.900 g / cm ³ .
The content of ethylene units in the copolymer (C) is preferably 70 to 95 mol%, more preferably 80 to 93 mol%, and the content of α-olefin units is preferably 5 to 30 mol%, and more. Preferably it exists in the range of 7-20 mol%.

The copolymer component (C) desirably has any of the following physical properties, and a film having superior low temperature impact resistance and drop impact strength can be obtained from a propylene polymer composition containing the copolymer component (C). Can do.
(1) The melt flow rate value measured at 190 ° C. under a load of 2.16 kg in accordance with ASTM D 1238 is preferably 0.01 to 5 g / 10 minutes, more preferably 0.1 to 3 g / 10 minutes. is there.
(2) The crystallinity measured by the X-ray diffraction method is preferably 5 to 40%, more preferably 7 to 30%.
(3) The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is preferably 3 or less, more preferably 2.5 or less. .
(4) Using a differential scanning calorimeter (DSC), the melting point determined from an endothermic curve measured under conditions of a heating rate of 10 ° C./min is preferably 40 to 100 ° C., more preferably 60 to 90 ° C. is there.

<< Propylene polymer composition >>
The propylene polymer composition of the present invention comprises the propylene polymer component (A), the propylene / α-olefin random copolymer component (B), and the ethylene / α-olefin random copolymer component (C). Including
(1) The propylene polymer component (A) and the propylene / α-olefin random copolymer component (B) have a weight ratio represented by (A) / (B) of 80/20 to 95/5, preferably Is in the range of 84/16 to 88/12,
(2) The content of the ethylene / α-olefin random copolymer component (C) is 2 to 15% by weight in the propylene polymer composition, preferably 4 to 12% by weight [provided that (A) + ( B) + (C) = 100% by weight. ],
(4) The melt flow rate (230 ° C.) of the propylene polymer composition is 2 to 10 (g / 10 minutes), and the ethylene unit content is 5 to 15% by weight, preferably 8 to 13% by weight. It is in the range.

Weight ratio of propylene polymer component (A) and propylene / α-olefin random copolymer component (B), amount of ethylene / α-olefin random copolymer (C), and ethylene of propylene polymer composition The propylene polymer composition with the unit content satisfying the above range is excellent in blocking resistance, low temperature impact resistance, initial heat seal strength and heat seal strength after heat treatment when used in a heat-fusible film. It is possible to obtain a film suitable for packaging a film, in particular, a packaged article that requires heating and sterilization treatment such as retort food.
The propylene polymer composition of the present invention preferably has a melt flow rate (MFR) measured at 230 ° C. under a load of 2.16 kg in accordance with ASTM D 1238, preferably 2 to 10 g / 10 min, more preferably 2. It is in the range of 5-8 g / 10 minutes. A composition having such a melt flow rate can produce a film having good film moldability and excellent low-temperature impact strength.

<< Production Method of Propylene Polymer Composition >>
The propylene polymer composition of the present invention can be produced, for example, by the following method.
(1) Each of the propylene polymer component (A), the propylene / α-olefin random copolymer component (B), and the ethylene / α-olefin random copolymer component (C) is prepared in advance. Then, each component is mixed at a predetermined blending ratio.
(2) A mixture of the propylene polymer component (A) and the propylene / α-olefin random copolymer component (B) is prepared in advance, and then the ethylene / α-olefin random copolymer component (C). A method of mixing at a predetermined blending ratio.

  The mixture of the propylene polymer component (A) and the propylene / α-olefin random copolymer component (B) is composed of the propylene polymer component (A) and the propylene / α-olefin random copolymer component (B). Can be prepared by mixing with different polymerization steps. The polymerization step of the propylene polymer component (A) and the polymerization step of the propylene / α-olefin random copolymer component (B) may be performed in series or in parallel. In the former case, it does not matter which step is preceded, and it is preferable to start the polymerization step of the propylene polymer component (A) first as a highly crystalline polymer as the propylene polymer component (A). Is preferable because it can be produced. The first polymerization step can be carried out by either batch polymerization or continuous polymerization, but continuous polymerization is preferred. The continuous polymerization step may be a single stage composed of one polymerization vessel, or may be a method using a plurality of polymerization vessels in multiple stages. A mixture of the propylene polymer component (A) and the propylene / α-olefin random copolymer component (B) obtained through such a polymerization step is usually also referred to as a propylene / α-olefin block copolymer. It is manufactured and sold.

  The mixture of the propylene polymer component (A) and the propylene / α-olefin random copolymer component (B) according to the present invention is a propylene containing a propylene polymer component and a propylene / α-olefin random copolymer component.・ Propylene polymer component (A) and propylene / α-olefin random copolymer by appropriately mixing two or more types of propylene / α-olefin block copolymers manufactured and sold as α-olefin block copolymers You may adjust so that a weight ratio with a component (B) may become the said range.

  A mixture of the propylene polymer component (A) and the propylene / α-olefin random copolymer component (B) is produced using an olefin stereoregular polymerization catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst. can do. As an example of a polymerization catalyst, a solid titanium catalyst component having an active magnesium compound, a titanium compound, a halogen compound, and an internal electron donor as essential components is supported on an organic or inorganic carrier, and a group I to group III of the periodic table is supported thereon. Examples of the catalyst system include a metal organometallic compound component and an external electron donor. This catalyst system may be preliminarily polymerized with olefin prior to main polymerization of propylene or the like. The solid titanium catalyst component is preferably a reaction product obtained by reacting an alcohol-containing magnesium compound and titanium tetrachloride in a hydrocarbon solvent, and the external electron donor is a diether compound and / or silane. Compounds are preferred. The polymerization catalyst described here can also be used for the production of an ethylene / α-olefin random copolymer.

As a polymerization method, any method such as suspension polymerization in a hydrocarbon solvent, suspension polymerization in a propylene solvent, gas phase polymerization, or a combination thereof can be employed. For example, the first step can be carried out by suspension polymerization in a propylene solvent, and the subsequent second step can be carried out by gas phase polymerization.
The mixture of the propylene polymer component (A) and the propylene / α-olefin random copolymer component (B) is not subjected to the above-described polymerization step, and the propylene polymer component (A) and propylene • α- It can also be obtained by melt-kneading the olefin random copolymer component (B).

  In applications where a high impact resistance film is required, the propylene polymer composition can further contain an elastomer component. As the elastomer component that can be blended, a general thermoplastic rubber can be used. Examples include ethylene / propylene copolymer rubber, ethylene / 1-butene copolymer rubber, ethylene / 1-hexene copolymer rubber, ethylene / 1-octene copolymer rubber, ethylene / propylene / diene copolymer. Mention may be made of rubbers, ethylene / 1-butene / diene copolymer rubbers, ethylene / propylene / 1-butene copolymer rubbers, styrene / butadiene block copolymers or hydrogenated styrene / isoprene block copolymers. .

Further, prior to film formation, the propylene polymer composition is antioxidant, heat stabilizer, lubricant, antistatic agent, hydrochloric acid absorbent, antiblocking agent, slip agent, pigment, as long as the object of the present invention is not impaired. You may mix | blend dye etc.
Examples of the antioxidant include a phenolic antioxidant, an organic phosphite antioxidant, a thioether antioxidant, a hindered amine antioxidant, and the like. Examples of the antiblocking agent include aluminum oxide, fine powder silica, polymethyl methacrylate powder, and silicon resin.
Examples of the slip agent include bisamides such as ethylene bisstearamide, higher fatty acid amides such as oleic acid amide and erucic acid amide. Examples of the lubricant include higher fatty acid metal salts such as calcium stearate, zinc stearate, and metal montanate, and polyolefin waxes such as polyethylene wax and polypropylene wax. Examples of the nucleating agent include rosin nucleating agents such as dibenzylidene sorbitol and partial metal salts of rosin acid, aluminum nucleating agents, and talc.

<Heat-fusion film>
The heat-fusible film of the present invention is a film made of the propylene polymer composition of the present invention. The method for producing the film is not particularly limited, and can be carried out by a generally employed method. For example, the propylene polymer composition pellets or powder is melted using a single-screw or twin-screw extruder, and the molten resin is extruded into a film form from a T die or an annular die provided at the tip of the extruder. Can be manufactured. The temperature of the molten resin in the extruder is usually 200 to 300 ° C, preferably 200 to 280 ° C.
When the molten resin is extruded from a T-die, the extruded film is brought into contact with a roll set at a constant temperature with water or another medium, cooled and solidified, and then wound. When extruded from an annular die, the exterior and / or interior of the annular film is cooled with a cooling medium, such as cooled air or water, and then the film is slit or wound as it is. The film is manufactured. The film thus obtained has a thickness of usually 20 to 1000 μm, preferably 30 to 200 μm, more preferably 40 to 100 μm.

The heat-fusible film of the present invention can be used as a general packaging film as it is as a single layer, and is particularly suitable for a sealant film for a packaged bag requiring heating and sterilizing treatment such as retort food. Moreover, the heat-fusible film of this invention can be laminated | stacked on the layer which can become a base material, and it can be used for the same use in the form of a laminated body.
Further, the heat-fusible film of the present invention has the above-mentioned propylene polymer component (A) or propylene heavy component in the heat-fusible layer as long as the heat-fusible layer has a film layer comprising the propylene polymer composition of the present invention. A multilayer film structure in which layers containing a propylene polymer such as a coalescence composition are laminated may be used.

<Heat-bonding laminate>
The heat-fusible laminate of the present invention is a laminate in which a base material layer is laminated on one side of the above-described heat-fusible film of the present invention. The substrate layer is not particularly limited as long as it can be used as a packaging material, and the shape thereof may be any of a sheet, a film, a tray, a container and the like, but is preferably a film.
Examples of usable base layer materials include aluminum, paper, polyester film, polycarbonate film, polyamide film, ethylene / vinyl alcohol copolymer film, polyvinyl alcohol film, polyvinyl chloride film, and polyvinylidene chloride film. . Examples of the form of the base material layer include thermoplastic resin films and sheets, trays and cup-shaped containers obtained by thermoforming the sheets, or similar shapes formed from aluminum foil or paper. Examples of films include polyester resin films such as polyethylene terephthalate and polyethylene naphthalate, polycarbonate films, polyamide films such as nylon 6 and nylon 66, ethylene / vinyl alcohol copolymer films, polyvinyl alcohol films, polyvinyl chloride films, poly Examples thereof include a vinylidene chloride film and a polyolefin film such as polypropylene.

When the base material layer is in the form of a film, the film may be an unstretched film or a film stretched in a uniaxial or biaxial direction. Furthermore, the thermoplastic resin film may be a film in which a metal such as aluminum or zinc, an oxide such as silica or aluminum oxide, or an inorganic substance is vapor-deposited. Furthermore, the composite and laminated body which combined them may be sufficient.
As a method for forming a laminated film by forming the heat-fusible film layer according to the present invention on the surface of the base material layer, a generally-used lamination method can be used as it is, and in this case, the adhesive layer is bonded between the two layers. A layer can be provided. For example, a urethane or isocyanate anchor coating agent is applied to the base layer and then a heat-sealable film is dry laminated on it, or a propylene polymer composition is extruded directly onto the base layer and laminated. It can also be produced by extrusion coating. Moreover, when a base material layer is formed from a thermoplastic resin, it can also shape | mold directly from both resin to a laminated film by a coextrusion method. In addition, in the case of a laminated film for packaging of a packaged item that requires heating and sterilization treatment such as retort food, a base material layer is usually laminated on one side of the heat-fusible film, but as another packaging material When using, a base material layer may be laminated | stacked not only on one side of a heat-fusible film but on both surfaces.

The laminated film thus obtained has a high heat-sealing strength (peeling strength of the heat-sealed portion) of the heat-fusible film layer when used as a packaging material, and is also suitable for retort treatment performed at high temperature and high pressure. Even after heat treatment, high heat seal strength is maintained, for example, at least 35 (N / 15 mm) peel strength is maintained.
Further, depending on the type of the base material layer, high gas barrier properties, mechanical strength, and the like are further imparted, and therefore, it can be used in a wide range of applications including retort food packaging. Moreover, this laminated body can be used in the form of a film, or can be used as a packaging material after changing to the shape of a tray or a container.

<Packaging body>
A package of an object to be packaged such as retort food, medicine, medical instrument, pet food, etc. that requires heating and sterilization treatment is a laminate in which a base layer is laminated with a heat-fusible film having the above characteristics. Using film as at least one packaging material, placing the heat-fusible film layer on the inner surface side, filling or packaging the retort food that will be the contents, etc. An article to be packaged is packaged by heat-sealing the film layer.
The packaging material may be a single layer of heat-fusible film, but the above-mentioned heat-fusible laminated film is preferable because various properties of the base material layer can be used. When the heat-fusible laminated film is used for manufacturing a package such as a retort food, a specific example of the laminated film includes a combination of a base material layer and a heat-fusible film layer described below.
Polyester layer / heat-sealable film, polyamide layer / heat-sealable film, polyester layer / aluminum foil / heat-sealable film, polyester layer / polyamide layer / aluminum foil / heat-sealable film, polyamide layer / polychlorinated Vinylidene layer / polyester layer / heat-fusible film.
In the package, heat sealing is performed after the heat-fusible film layer is disposed so as to be located in the innermost layer. Therefore, the heat seal strength of the heat seal portion is high, and the heat seal strength is high even after the heat treatment. Is retained.

Thus, the heat-fusible film obtained from the propylene polymer composition of the present invention has a high heat seal strength, and the decrease in heat seal strength is extremely small even after heat treatment, resulting in blocking resistance. It has excellent low temperature impact strength. Furthermore, the seal part hardly peels off or breaks even if it is placed under normal temperature or refrigerated / frozen storage conditions for heating / sterilization treatment, transportation, and for a long period of time.
Therefore, when it is used as a package of a packaged item that requires heating and sterilization treatment, it is necessary to heat and sterilize the retort food, etc., which is the content during transportation or handling in stores or at home. The contents to be packaged are less likely to leak out, and the contents are not easily altered even when stored for a long time at room temperature or under refrigeration / freezing.
In addition, as a packaged object of the package of the present invention, not only general foods but also general objects to be packaged that require heating and sterilization treatment such as retort foods, pharmaceuticals, medical instruments, pet foods, etc. .

EXAMPLES Next, although an Example demonstrates this invention in detail, this invention is not restrict | limited at all by those Examples.
In addition, the physical-property value which shows the property of a polymer and a polymer composition, and the physical-property value for evaluating a film and a laminated film were each measured with the test method described below.

(1) Measuring method of polymer physical properties (Examples 1-4, Comparative Example 1)
<Ethylene content>
Absorbance at 720 cm ⁻¹ was measured using an infrared absorption spectrum and calculated from the value.
<Intrinsic viscosity [η]>
Using an Ubbelohde viscometer, the polymer sample was dissolved in decalin, the viscosity of the solution was measured at 135 ° C., and the intrinsic viscosity was determined from the measured value.
<Melt flow rate (MFR)>
In accordance with ASTM D 1238, measurement was performed under the conditions of 190 ° C. or 230 ° C. and a load of 2.16 kg.
<Amount of decane soluble>
The composition sample was completely dissolved in decane and then left at 23 ° C. for 24 hours. Further, the precipitate was separated by centrifugation, and the weight was calculated by subtracting the weight of the precipitate from the sample weight.

(2) Method for measuring physical properties of monolayer film (Examples 1 to 4, Comparative Example 1)
<Blocking resistance (N / 5.2 cm ² )>
In advance, a biaxially stretched nylon film having a thickness of 15 μm is used as the base material layer, and the corona surface of the base material layer and the corona surface of the heat-fusible film having a thickness of 70 μm are dried using a urethane-based adhesive. Lamination was performed to obtain a heat-fusible laminated film.
A test piece of 20 × 150 mm was cut out from the laminated film, and the two heat-sealable film / heat-sealable film surface and Ny / heat-sealable film surface were overlapped and 5.2 cm ² . After leaving to stand at 50 ° C, 60 ° C, 70 ° C for 3 days under a 4kg load on the area, the peel strength was measured at a crosshead speed of 300 (mm / min) using a Tensilon universal testing machine RTM-100 manufactured by Orientec Corp. did.
<Heat seal strength (N / 15mm)>
The heat-sealable film layers of the above laminated film are overlapped with each other, and using a heat sealer TP-701-B manufactured by Tester Sangyo Co., Ltd. The heat sealing was performed under the condition of time 1 second.
Cut out a 15 mm wide test piece from the created heat seal part (vertical: side part) and peel off the heat seal part at a crosshead speed of 500 (mm / min) using a Tensilon universal testing machine RTM-100 manufactured by Orientec Corporation. The peel strength at that time was defined as the heat seal strength (N / 15 mm) before the retort sterilization treatment.
On the other hand, the heat seal strength after retort sterilization was measured by the following method. That is, it put into the hot-water shower type high-pressure high-temperature sterilization processing apparatus, processed for 30 minutes at 121 degreeC, and after natural drying, the heat seal intensity | strength (N / 15mm) was measured by the same method as the above.
<Impact strength (KJ / m)>
A 100 × 100 mm test piece was cut out from the heat-fusible film and measured using a constant temperature phased film impact tester manufactured by Toyo Seiki Co., Ltd. with a measurement temperature of −20 ° C. and a hammer tip diameter of 1/2 inch. .
<Bending whitening resistance>
The heat-fusible film was cut into A4 size, both ends of the film were held with both hands, and after thirty peeling, it was examined whether or not the bent portion of the film was whitened.
<Haze (%)>
Using Haze Meter (NDH-300A manufactured by Nippon Denshoku Industries Co., Ltd.), the haze of one heat-fusible film was measured according to JIS.
Measured according to K 7105.
<Surface roughness (μm)>
Ra (average roughness) and Rz (10-point average height) were measured with a non-contact three-dimensional surface shape roughness meter (WYKO).

(3) Measuring method of physical properties of multilayer film (Examples 5 to 10, Comparative Example 2)
<Blocking resistance (N / 5.2 cm ² )>
An aluminum foil surface of a laminate in which a biaxially stretched polyethylene terephthalate film (PET) having a thickness of 12 μm and an aluminum foil (AL) having a thickness of 7 μm are dry-laminated using a urethane adhesive in advance as a base material layer. Then, the corona surface of the heat-fusible film having a thickness of 70 μm was dry-laminated using a urethane adhesive to obtain a laminate.
A 20 × 150 mm test piece is cut out from the laminated film, and the two heat-sealable film / heat-sealable film surfaces and the PET / heat-sealable film surface are overlapped, and 5.2 cm ² . After leaving to stand at 50 ° C, 60 ° C, 70 ° C for 3 days under a 4kg load on the area, the peel strength was measured at a crosshead speed of 300 (mm / min) using a Tensilon universal testing machine RTM-100 manufactured by Orientec Corp. did.
<Heat seal strength of bag-made products (N / 15mm)>
The heat-fusible film laminate was made into a bag to obtain a three-side sealed bag having a bag size of 125 mm × 175 mm. From the lateral heat seal portion (side portion) and bottom heat seal portion (bottom portion) of the bag-made product, a test piece having a width of 15 mm was cut off, and the heat seal portion was peeled off at a crosshead speed of 500 (mm / min). The peel strength at that time was defined as the heat seal strength (N / 15 mm) before the retort sterilization treatment. The measurement of the heat seal strength after the retort sterilization treatment was performed as described above.
<Dropping bag breaking strength (times)>
The prepared three-side seal bag is filled with 200 CC of water, and using the above-mentioned heat sealer TP-701-B manufactured by Tester Sangyo Co., Ltd. Heat sealing was performed. Also, put it in a hot water shower type high-pressure high-temperature sterilizer, treat it at 121 ° C for 30 minutes, let it air dry, store it in an atmosphere of 5 ° C, and under the same conditions, weigh 40cm in height and 1.0kg in weight. It was dropped on a flat surface until it was broken, and the number of drops was counted when the bag was broken.

The polymers used in Examples and Comparative Examples of the present invention are shown below.
(1) Propylene polymer composition-1 (propylene / α-olefin block copolymer)
: (P-1)
Melt flow rate (230 ° C.): 2.5 g / 10 minutes.
Propylene polymer component (a1-1): 72% by mass
Propylene / ethylene random copolymer component (a2-1): 13% by mass
Ethylene unit content: 22 mass%, intrinsic viscosity [η]: 3.2 dl / g
-Ethylene / 1-butene random copolymer (a3-1): 15% by mass
Density: 0.885 g / cm ³ , ethylene unit content: 79% by mass
(2) Propylene polymer composition-2 (propylene / α-olefin block copolymer)
: (P-2)
Melt flow rate (230 ° C.): 3.2 g / 10 minutes.
Propylene polymer component (b1-1): 85% by mass
Propylene / ethylene random copolymer component (b2-1): 15% by mass
Ethylene unit content: 22 mass%, intrinsic viscosity [η]: 3.2 dl / g
(3) Propylene polymer composition-3 (propylene / α-olefin block copolymer)
: P-3)
Melt flow rate (230 ° C.): 8.5 g / 10 minutes
Propylene polymer component (c1-1): 87.5% by mass
Propylene / ethylene random copolymer component (c2-1): 12.5% by mass
Ethylene unit content: 43% by mass, intrinsic viscosity [η]: 3.6 dl / g

Example 1
The propylene polymer composition-1: 70% by mass and the propylene polymer composition-3: 30% by mass are mixed, and the propylene polymer composition having the components shown in Table 1 (Composition-I ), Using an unstretched film molding machine equipped with a 40mmφ extruder, extrude from a T-die at 270 ° C at an extrusion temperature of 250 ° C, quench with a 40 ° C casting roll, and corona-treat one side. A heat-fusible film having a thickness of 70 μm was obtained. The physical properties of the obtained heat-fusible film were measured by the method described above. The results are shown in Table 1.

(Example 2)
In place of the composition-I used in Example 1, the propylene polymer composition-1: 60% by mass and the propylene polymer composition-3: 40% by mass were mixed and listed in Table 1. Except for using the propylene-based polymer composition (Composition-II) having components, the same procedure as in Example 1 was performed to obtain a heat-fusible film having a thickness of 70 μm. The physical properties of the obtained heat-fusible film were measured by the method described above. The results are shown in Table 1.

Example 3
In place of the composition-I used in Example 1, the propylene polymer composition-1: 50% by mass and the propylene polymer composition-3: 50% by mass were mixed and listed in Table 1. Except for using the propylene-based polymer composition (Composition-III) having components, the same procedure as in Example 1 was performed to obtain a heat-fusible film having a thickness of 70 μm. The physical properties of the obtained heat-fusible film were measured by the method described above. The results are shown in Table 1.

Example 4
In place of the composition-I used in Example 1, the propylene polymer composition-1: 30% by mass and the propylene polymer composition-3: 70% by mass were mixed, Except for using the propylene-based polymer composition (Composition-IV) having components, the same procedure as in Example 1 was performed to obtain a heat-fusible film having a thickness of 70 μm. The physical properties of the obtained heat-fusible film were measured by the method described above. The results are shown in Table 1.

(Comparative Example 1)
In place of the composition-I used in Example 1, 70% by mass of the propylene polymer composition-1 and 30% by mass of the propylene polymer composition-2 are mixed, and are described in Table 1. Except for using the propylene-based polymer composition (Composition-V) having components, the same procedure as in Example 1 was performed to obtain a heat-fusible film having a thickness of 70 μm. The physical properties of the obtained heat-fusible film were measured by the method described above.
As shown in Table 1, it can be seen that the heat-fusible films of the examples are excellent in blocking properties, heat seal properties with little change before and after retorting, low-temperature impact properties, and bending whitening properties.

注：（ ）内の数字は、マトリックスとゴムドメインの合計を100wt%とした
ときの量比を示す。

Note: Numbers in parentheses are the total of matrix and rubber domain 100wt%
The quantity ratio is shown.

(Example 5)
Except that the propylene polymer composition-1 (P-1) is laminated on the intermediate layer and the corona-treated layer using the composition-I used in Example 1 as a heat-sealing layer, the same procedure as in Example 1 is performed. A heat-fusible film having a thickness of 70 μm was obtained. The physical properties of the obtained heat-fusible film were measured by the method described above. The results are shown in Table 2.
(Example 6)
The same procedure as in Example 1 was performed except that the propylene polymer composition-1 (P-1) was laminated on the intermediate layer and the corona-treated layer using the composition-II used in Example 2 as a heat-sealing layer. A heat-fusible film having a thickness of 70 μm was obtained. The physical properties of the obtained heat-fusible film were measured by the method described above. The results are shown in Table 2.
(Example 7)
The same procedure as in Example 1 was performed except that the propylene polymer composition-1 (P-1) was laminated on the intermediate layer and the corona-treated layer using the composition-III used in Example 3 as a heat-sealing layer. A heat-fusible film having a thickness of 70 μm was obtained. The physical properties of the obtained heat-fusible film were measured by the method described above. The results are shown in Table 2.

(Example 8)
The same procedure as in Example 1 was performed except that the propylene polymer composition-1 (P-1) was laminated on the intermediate layer and the corona-treated layer using the composition-IV used in Example 4 as a heat-sealing layer. A heat-fusible film having a thickness of 70 μm was obtained. The physical properties of the obtained heat-fusible film were measured by the method described above. The results are shown in Table 2.
Example 9
The same procedure as in Example 1 was performed except that the composition-II used in Example 2 was used as a heat-sealing layer, and the propylene polymer composition-2 (P-2) was laminated on the intermediate layer and the corona-treated layer. A heat-fusible film having a thickness of 70 μm was obtained. The physical properties of the obtained heat-fusible film were measured by the method described above.
(Example 10)
The same procedure as in Example 1 was performed except that the composition-II used in Example 2 was used as a heat-sealing layer, and the propylene polymer composition-3 (P-3) was laminated on the intermediate layer and the corona-treated layer. A heat-fusible film having a thickness of 70 μm was obtained. The physical properties of the obtained heat-fusible film were measured by the method described above.

(Comparative Example 2)
The same procedure as in Example 1 was conducted except that the composition-V used in Comparative Example 1 was used as a heat-sealing layer, and the propylene polymer composition-1 (P-1) was laminated on the intermediate layer and the corona-treated layer. A heat-fusible film having a thickness of 70 μm was obtained. The physical properties of the obtained heat-fusible film were measured by the method described above. As shown in Table 2, it can be seen that the heat-fusible laminates of the examples are excellent in blocking property, heat sealability with little change before and after retorting, and drop bag breaking strength.

The heat-fusible film and the laminate thereof of the present invention can be used not only as a general-purpose packaging film but also as a packaging film for an article to be packaged that requires heating / sterilization treatment such as retort food. Furthermore, for heavy food applications that do not necessarily require heating and sterilization treatment, medical packaging such as infusion bags and blood bags that require heating and sterilization treatment, packaging bags for storing electronic parts, etc. As a material for interior materials such as base films and automobile ceiling materials, it is used in many fields.

Claims (5)

A propylene polymer composition comprising a propylene polymer component (A), a propylene / α-olefin random copolymer component (B), and a random copolymer component (C) of ethylene and an α-olefin having 4 or more carbon atoms. Because
(1) Propylene polymer component (A) and propylene / α-olefin random copolymer component (B) have a weight ratio represented by (A) / (B) in the range of 80/20 to 95/5. There,
(2) The propylene / α-olefin random copolymer component (B) is in the range of 2 to 3.8 dl / g, and the content of propylene units is more than 50% by weight and less than 70% by weight (however, And the total content of propylene units and α-olefin units is 100% by weight).
(3) The ethylene / α-olefin random copolymer component (C) has a density of 0.865 to 0.910 (g / cm ³ ), and 2 to 15% by weight [provided that (A) + (B) + (C) = 100 wt% ],
(4) The melt flow rate (230 ° C.) of the propylene polymer composition is 2 to 10 (g / 10 minutes), and the ethylene unit content is in the range of 5 to 15% by weight. Propylene polymer composition.   A heat-fusible film comprising the propylene polymer composition according to claim 1.   A heat-fusible film having a multilayer structure of two or more layers comprising the propylene polymer composition according to claim 1 in a heat-fusible layer.   A heat-fusible laminate, wherein a base material layer is laminated on one side of the heat-fusible film according to claim 2. A package using the heat-fusible laminate according to claim 4.