Resin composition and its use

Abstract

The purpose of the present invention is to obtain a resin composition that exhibits good high-speed moldability, has low adhesion to a chill roller or guide roller at the time of film formation, and exhibits excellent adherence to a polar group-containing resin (polar resin). The present invention relates to a resin composition including: 75-100 parts by mass of a propylene-based polymer (A); and 0-25 parts by mass of a copolymer (B) that satisfies prescribed requirements and is composed of ethylene and at least one type of α-olefin selected from among α-olefins having 3-20 carbon atoms [where the total amount of (A) and (B) is 100 parts by mass]. At least part of the propylene-based polymer (A) is modified by a polar compound. The resin composition satisfies prescribed requirements.

Description

Technical Field

[0001] Polyolefin resins such as polyethylene and polypropylene are excellent in moldability, hygiene, water vapor barrier properties, etc., and are also inexpensive. Therefore, they are widely used as constituent materials for various food packaging materials.

[0002] Since polyolefin resins have high gas permeability, in order to maintain the freshness of the contents and extend the expiration date, they are often used as food packaging materials after being laminated with polar resins such as ethylene-vinyl alcohol copolymer (EVOH), polyamide (PA), and polyester (e.g., polyethylene terephthalate (PET)) having gas barrier properties.

[0003] Since polyolefin resins are inferior in adhesion to polar resins, graft-modified polyethylene, polypropylene, etc. are used as an adhesive layer, or polyolefin resins containing graft-modified polyethylene, polypropylene, etc. are used as polyolefin resins.

[0004] Food packaging materials made of such laminates are produced by melt (co)extrusion molding such as the casting method, inflation method, and extrusion coating method. And in order to improve the productivity of food packaging materials, speeding up the molding process has been studied. However, since some of the materials constituting the laminate cannot cope with high-speed molding, there are cases where the productivity of multilayer laminates cannot be improved.

[0005] In order to solve the above problems, for example, Patent Document 1 discloses that the molding stability of a polypropylene film is improved by blending a polypropylene resin with a high melt tension polypropylene resin. However, this is a description regarding the melt film stability during inflation molding, and no mention is made of high-speed moldability.

[0006] Patent Documents 2 and 3 disclose an adhesive resin composition capable of high-speed lamination molding. However, since it is a highly adhesive resin composition containing a soft polypropylene-based polymer, when co-extrusion film molding is performed with polypropylene or EVOH, if the "wrapping phenomenon" occurs where the adhesive resin composition wraps around the film edges, it may stick to the chill roll or guide roll, and the molding speed may not be increased.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] An object of the present invention is to obtain a resin composition having good high-speed moldability, low adhesiveness to a chill roll or guide roll during film molding, and excellent adhesiveness to a resin having a polar group such as ethylene-vinyl alcohol copolymer (EVOH), polyamide (PA), or polyester (polar resin), and a laminate suitable for a food packaging film containing the resin composition.

Means for Solving the Problems

[0009] The present invention is 75 to 100 parts by mass of a polypropylene-based polymer (A), and 0 to 25 parts by mass of a copolymer (B) of ethylene and at least one α-olefin selected from α-olefins having 3 to 20 carbon atoms, satisfying the following requirements (b-1) and (b-2) [however, the total of (A) and (B) is 100 parts by mass]. The propylene-based polymer (A) is at least partially modified with a polar compound, and The resin composition relates to a resin composition characterized by satisfying the following requirements (1) to (3). (b-1) The content of the structural unit derived from ethylene is 50 to 99 mol%, and the content of the structural unit derived from an α-olefin having 3 to 20 carbon atoms is 1 to 50 mol% (however, the total of the content of the structural unit derived from ethylene and the content of the structural unit derived from the α-olefin is 100 mol%). (b-2) The melt flow rate (MFR; 190 °C, 2.16 kg load) measured by ASTM D1238 is in the range of 0.1 to 50 g / 10 min. (1) The melt flow rate (MFR) measured at a temperature of 230 °C and a load of 2.16 kg is in the range of 1 to 100 g / 10 min. (2) The density is in the range of 0.89 to 0.93 g / cm 3 (3) The melt tension measured at 230 °C is 10.0 mN or less.

Advantages of the Invention

[0010] The resin composition of the present invention has good high-speed moldability, low adhesiveness to chill rolls and guide rolls during film forming, and excellent adhesiveness to resins having polar groups (polar resins) such as ethylene-vinyl alcohol copolymer (EVOH), polyamide (PA), and polyester (e.g., polyethylene terephthalate (PET)).

Embodiments for Carrying Out the Invention

[0011] The resin composition of the present invention is a composition containing a propylene-based polymer (A) and an ethylene-α-olefin copolymer (B) (hereinafter, the copolymer is also referred to as "ethylene-α-olefin copolymer (B)").

[0012] <Propylene-based polymer (A)> One of the components constituting the resin composition of the present invention, the propylene-based polymer (A), can satisfy the following requirements (1) to (4).

[0013] 〈Requirement (1)〉 The melt flow rate (MFR) measured at a temperature of 230 °C and a load of 2.16 kg is in the range of 1 to 100 g / 10 min, preferably 1 to 50 g / 10 min, more preferably 1 to 30 g / 10 min. By satisfying the above range of the MFR of the propylene-based polymer (A), a molded article with good extrudability and excellent surface appearance can be obtained.

[0014] 〈Requirement (2)〉 The density is in the range of 0.89 to 0.93 g / cm 3 , preferably 0.89 to 0.92 g / cm 3 , more preferably 0.90 to 0.92 g / cm 3 of the range. By satisfying the above range of the density of the propylene-based polymer (A), the adhesiveness to the chill roll and guide roll during film forming is low, and the molding stability is excellent.

[0015] <Requirement (3)> The melt tension measured at 230 °C is in the range of 10 mN or less, preferably 9.5 mN or less. When the melt tension of the propylene-based polymer (A) is 10 mN or less, when the film take-up speed is increased, pulsation of the melt curtain extruded by melting hardly occurs, and the high-speed moldability is excellent.

[0016] 〈Requirement (4)〉 The propylene-based polymer (A) according to the present invention is at least partially modified with a polar compound, preferably modified with an unsaturated carboxylic acid or a derivative thereof (preferably graft-modified).

[0017] In the present invention, "modified with a polar compound in at least part" means both a mixture (composition) of an unmodified propylene-based polymer and a propylene-based polymer modified with a polar compound, and the case where the whole of the propylene-based polymer (A) is modified with a polar compound. The phrase "in at least part" indicates that it is not necessarily required that the whole of the propylene-based polymer (A) according to the present invention is modified with a polar compound.

[0018] The amount of modification of the polar compound (graft amount of the polar compound) in the propylene-based polymer (A) according to the present invention is in the range of 0.01 to 10% by mass, more preferably 0.02 to 5% by mass, and even more preferably 0.04 to 1% by mass.

[0019] The propylene-based polymer (A) according to the present invention may be a propylene-based polymer (A) entirely modified with a polar compound, or may be a mixture (composition) of a propylene-based polymer modified with a polar compound and an unmodified propylene-based polymer. In the case of a mixture, it is necessary that the amount of modification of the polar compound in the mixture satisfies the above range.

[0020] When the propylene-based polymer (A) according to the present invention is a mixture of a propylene-based polymer modified with a polar compound and an unmodified propylene-based polymer, it is preferable that the mixture satisfies the above requirements (1) to (3), and more preferably satisfies the following requirements (5) to (7). The propylene-based polymer modified with a polar compound or the unmodified propylene-based polymer does not necessarily need to satisfy all of the above requirements (1) to (3) and the following requirements (5) to (7).

[0021] Also, when the propylene-based polymer (A) according to the present invention is a mixture of a propylene-based polymer modified with a polar compound and an unmodified propylene-based polymer, the amounts of the propylene-based polymer modified with a polar compound and the unmodified propylene-based polymer are not particularly limited and can be appropriately determined depending on the amount of modification of the propylene-based polymer modified with a polar compound.

[0022] When the amount of modification of the propylene-based polymer (A) according to the present invention satisfies the above range, a resin composition excellent in adhesiveness to polar resins such as ethylene-vinyl alcohol copolymer (EVOH), polyamide (PA), and polyester can be obtained, and a molded article with a low content of foreign matters such as fish eyes and black spots can be obtained during melt extrusion molding.

[0023] As a method for bringing the amount of modification of the propylene-based polymer (A) according to the present invention within the above range, there can be adopted a method of modifying the propylene-based polymer with a polar compound to bring the amount of modification within the above range, or a method of mixing a propylene-based polymer obtained by previously increasing the amount of modification and an unmodified propylene-based polymer, and adjusting the amount of modification within the above range to obtain the propylene-based polymer (A).

[0024] As a method for modifying the propylene-based polymer according to the present invention, various known methods can be used. For example, the propylene-based polymer is dissolved in an organic solvent, and then a polar compound such as an unsaturated carboxylic acid or its derivative and, if necessary, a radical initiator such as an organic peroxide are added to the obtained solution, and the reaction is usually carried out at a temperature of 60 to 350°C, preferably 80 to 190°C, for 0.5 to 15 hours, preferably 1 to 10 hours. Alternatively, using an extruder or the like, in the absence of a solvent, a propylene-based polymer, an unsaturated carboxylic acid or its derivative, and, if necessary, a radical initiator such as an organic peroxide are added, and the reaction is usually carried out at a temperature equal to or higher than the melting point of the propylene-based polymer, preferably 160 to 350°C, for 0.5 to 10 minutes.

[0025] The amount of graft modification of the propylene-based polymer (A) is the amount of structural units (amount of graft modification) derived from a polar compound such as an unsaturated carboxylic acid or its derivative. Using an infrared absorption analyzer, the intensity of the peak (when maleic anhydride is used, 1790 cm -1 ) derived from the above structural units is measured and quantified using a calibration curve prepared in advance. The propylene-based polymer (A) according to the present invention preferably satisfies the following requirement (5).

[0026] 〈Requirement (5)〉 The propylene-based polymer (A) according to the present invention preferably has a melt tension measured at 250°C of 7 mN or less, more preferably 6.9 mN or less, and even more preferably 6.8 mN or less.

[0027] When the melt tension of the propylene-based polymer (A) measured at 250°C satisfies the above range, pulsation of the melt curtain during melt extrusion is less likely to occur when the film take-up speed is increased, and it has excellent high-speed moldability.

[0028] The melt tension of the propylene-based polymer (A) according to the present invention was measured by the following measurement method. Using an orifice with a nozzle diameter of 2.095 mm and a length of 8.0 mm on a Capirograph 1D (cylinder diameter 9.55 mm, cylinder effective length 250 mm) manufactured by Toyo Seiki Seisaku-sho, Ltd., the propylene-based polymer (A) was melt-extruded at set temperatures of 230°C and 250°C and a piston moving speed of 15 m / min, and the melt-extruded strand was taken up at a take-up speed of 15 m / min for a certain period of time. The average melt tension within the measurement time was defined as the melt tension (mN). The propylene-based polymer (A) according to the present invention preferably satisfies the following requirement (6).

[0029] 〈Requirement (6)〉 The propylene-based polymer (A) according to the present invention preferably has a crystallization peak measured by a differential scanning calorimeter (DSC) in the range of 120 to 135°C, more preferably 120 to 132°C, and even more preferably 120 to 130°C.

[0030] When the crystallization peak of the propylene-based polymer (A) satisfies the above range, solidification of the melt curtain during film molding progresses easily, and it has excellent molding stability. The propylene-based polymer (A) according to the present invention preferably satisfies the following requirement (7).

[0031] 〈Requirement (7)〉 The propylene-based polymer (A) according to the present invention preferably has a difference between the crystallization peak and the melting peak measured by a differential scanning calorimeter (DSC) in the range of 35 °C or more, more preferably 36 °C or more, and even more preferably 37 °C or more.

[0032] The propylene-based polymer (A) in which the difference between the crystallization peak and the melting peak satisfies the above range is excellent in adhesion to polar resins such as ethylene-vinyl alcohol copolymer (EVOH), polyamide (PA), and polyester.

[0033] The method for measuring the crystallization temperature (crystallization peak) and the melting point (melting peak) of the propylene-based polymer (A) according to the present invention will be described later.

[0034] The propylene-based polymer (A) according to the present invention can include a propylene homopolymer or a copolymer of propylene and at least one α-olefin having 2 to 20 carbon atoms other than propylene. Here, examples of the α-olefin having 2 to 20 carbon atoms other than propylene include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, etc., and ethylene or an α-olefin having 4 to 10 carbon atoms is preferred.

[0035] The copolymer of propylene and these α-olefins may be a random copolymer or a block copolymer. The structural units derived from these α-olefins can be contained in the copolymer of α-olefin and propylene at a ratio of 35 mol% or less, preferably 30 mol% or less.

[0036] Note that the propylene-based polymer (A) according to the present invention is not limited to one kind and may be a mixture (composition) of two or more kinds. When the propylene-based polymer (A) according to the present invention is a composition of two or more kinds, the composition preferably satisfies the above requirements.

[0037] The method for producing the propylene-based polymer (A) according to the present invention is not particularly limited, and examples thereof include well-known methods using well-known catalysts such as Ziegler-Natta catalysts and metallocene catalysts.

[0038] The propylene-based polymer (A) according to the present invention may have either an isotactic structure or a syndiotactic structure, and either structure can be selected in consideration of the compatibility with the ethylene-α-olefin copolymer (B) described below.

[0039] <Ethylene-α-olefin copolymer (B)> The ethylene-α-olefin copolymer (B), which is another component of the resin composition of the present invention, is a copolymer of ethylene and at least one α-olefin selected from α-olefins having 3 to 20 carbon atoms and satisfies the following requirements (b-1) and (b-2).

[0040] 〈Requirement (b-1)〉 The content of the structural unit derived from ethylene is in the range of 50 to 99 mol%, preferably 70 to 95 mol%, more preferably 75 to 90 mol%, and the content of the structural unit derived from an α-olefin having 3 to 20 carbon atoms is 1 to 50 mol%, preferably 5 to 30 mol%, more preferably 10 to 25 mol% (however, the total of the content of the structural unit derived from ethylene and the content of the structural unit derived from the α-olefin is 100 mol%).

[0041] By the content of the structural unit derived from ethylene satisfying the above range, the resin composition containing the ethylene-α-olefin copolymer (B) has good high-speed moldability and low adhesiveness to chill rolls and guide rolls during film molding.

[0042] 〈Requirement (b-2)〉 The melt flow rate (MFR; 190 ° C., 2.16 kg load) measured by ASTM D1238 is in the range of 0.1 to 50 g / 10 min, preferably 0.1 to 35 g / 10 min, more preferably 1 to 35 g / 10 min.

[0043] As the method for producing the ethylene-α-olefin copolymer (B) according to the present invention, it is not particularly limited, and well-known methods using well-known catalysts such as Ziegler-Natta catalysts and metallocene catalysts can be mentioned.

[0044] 《Composition of Propylene Polymer (A) and Ethylene-α-olefin Copolymer (B)》 Quantification of the content ratio of the structural unit derived from α-olefin of the propylene polymer (A) and the structural unit derived from propylene, and quantification of the content ratio of the structural unit derived from α-olefin of the ethylene-α-olefin copolymer (B) and the structural unit derived from ethylene are 13 Performed by C-NMR under the following apparatus and conditions.

[0045] Using a JECX400P type nuclear magnetic resonance apparatus manufactured by JEOL Ltd., a mixed solvent of deuterated orthodichlorobenzene / deuterated benzene (80 / 20% by volume) was used as the solvent, the sample concentration was 60 mg / 0.6 mL, the measurement temperature was 120 °C, and the observed nucleus was 13 C (100 MHz), the sequence was single pulse proton decoupling, the pulse width was 4.62 μs (45° pulse), the repetition time was 5.5 s, the number of integrations was 8000 times, and the condition with 29.73 ppm as the reference value of the chemical shift was adopted.

[0046] <Resin Composition> The resin composition of the present invention contains 75 to 100 parts by mass, preferably 80 to 100 parts by mass, more preferably 90 to 100 parts by mass of the above propylene polymer (A), and 0 to 25 parts by mass, preferably 0 to 20 parts by mass, more preferably 0 to 10 parts by mass of the copolymer (B) with the above ethylene-α-olefin [however, the total of (A) and (B) is 100 parts by mass].

[0047] When the propylene-based polymer (A) contained in the resin composition of the present invention is a mixture of a propylene-based polymer modified with a polar compound and an unmodified propylene-based polymer, the amount of the propylene-based polymer modified with the polar compound in the propylene-based polymer (A) is usually in the range of 1 to 25 parts by mass or 1 to 25% by mass, preferably 2 to 20 parts by mass or 2 to 20% by mass, more preferably 3 to 15 parts by mass or 3 to 15% by mass. Furthermore, the resin composition of the present invention satisfies the following requirements (1) to (3).

[0048] 〈Requirement (1)〉 The melt flow rate (MFR) measured at a temperature of 230 °C and a load of 2.16 kg is in the range of 1 to 100 g / 10 min, preferably 1 to 50 g / 10 min, more preferably 1 to 30 g / 10 min. By satisfying the above range of the MFR of the resin composition, an extrudable resin composition with excellent surface appearance can be obtained.

[0049] 〈Requirement (2)〉 The density is in the range of 0.89 to 0.93 g / cm 3 , preferably 0.89 to 0.92 g / cm 3 , more preferably 0.90 to 0.92 g / cm 3 in the range of. By satisfying the above range of the density of the resin composition, a resin composition with low adhesiveness to the chill roll and guide roll during film forming and excellent molding stability can be obtained.

[0050] 〈Requirement (3)〉 The melt tension measured at 230 °C is in the range of 10 mN or less or 10.0 mN or less, preferably 9.5 mN or less, more preferably 9.1 mN or less.

[0051] By satisfying the above range of the melt tension of the resin composition, it is difficult to generate pulsation of the melt curtain during film forming, and a resin composition with excellent high-speed moldability can be obtained. The melt tension of the resin composition measured at 230°C can be controlled by changing the blending amounts of the propylene-based polymer (A) which tends to have a relatively low melt tension and the ethylene-α-olefin copolymer (B) which tends to have a relatively high melt tension, or by changing the blending amounts of the respective propylene-based polymers when the propylene-based polymer (A) is a composition of two or more types, or by changing the presence or absence, the addition amount, or the type of the crystallization nucleating agent described later, etc.

[0052] The resin composition of the present invention preferably satisfies the following requirement (4). 〈Requirement (4)〉 The melt tension of the resin composition of the present invention measured at 250°C is preferably in the range of 7 mN or less or 7.0 mN or less, more preferably 6.9 mN or less, and even more preferably 6.8 mN or less.

[0053] A resin composition whose melt tension measured at 250°C satisfies the above range is less likely to generate pulsations in the melt curtain during film forming and is excellent in high-speed moldability. The melt tension of the resin composition measured at 250°C can be controlled by the same method as the method for controlling the melt tension of the resin composition measured at 230°C. In addition, the measurement of the melt tension of the resin composition of the present invention is the same as the measurement method of the melt tension of the propylene-based polymer (A) described above. The resin composition of the present invention preferably satisfies the following requirement (5).

[0054] 〈Requirement (5)〉 The resin composition of the present invention preferably has a crystallization peak derived from the propylene-based polymer (A) in the range of 120 to 135°C, more preferably 120 to 132°C, and even more preferably 120 to 130°C when measured by a differential scanning calorimeter (DSC). A resin composition whose crystallization peak satisfies the above range is likely to progress solidification of the melt curtain during film forming and is excellent in molding stability.

[0055] The resin composition of the present invention preferably satisfies the following requirement (6). <Requirement (6)> When the resin composition of the present invention is measured by a differential scanning calorimeter (DSC) preferably represented by the following formula, the difference between the crystallization peak derived from the propylene-based polymer (A) and the melting peak derived from the propylene-based polymer (A) is 35 ° C or higher, more preferably 36 ° C or higher, still more preferably 37 ° C or higher. [Melting peak (° C) derived from propylene-based polymer (A)] - [Crystallization peak (° C) derived from propylene-based polymer (A)]

[0056] The resin composition in which the difference between the crystallization peak and the melting peak satisfies the above range is excellent in adhesion to polar resins such as ethylene-vinyl alcohol copolymer (EVOH), polyamide (PA), and polyester.

[0057] The measurement of the crystallization temperature (crystallization peak) and the melting point (melting peak) of the resin composition of the present invention is the same as the measurement method of the crystallization temperature (crystallization peak) and the melting point (melting peak) of the propylene-based polymer (A) described above.

[0058] The resin composition of the present invention preferably contains a crystal nucleating agent in addition to the propylene-based polymer (A) and the ethylene-α-olefin copolymer (B). Specific examples of the crystal nucleating agent that can be added to the resin composition of the present invention include, for example, sodium benzoate, bisbenzylidene sorbitol, bis (p-methylbenzylidene) sorbitol, bis (p-ethylbenzylidene) sorbitol, sodium-2,2 -Methylenebis (4,6-di-t-butylphenyl) phosphite, talc, titanium oxide, aluminum hydroxy-di-p-t-butylbenzoate, aromatic phosphate salt, aromatic carboxylic acid, D-glycero-L-glucono Nitol, nonitol-based nucleating agents such as 7,8,9,-trideoxy-3,5: 45-bis-O-[(R-propylphenyl) methylene], and rosin-based nucleating agents. These can be used alone or in combination of two or more.

[0059] When the resin composition of the present invention contains a crystal nucleating agent, it is 0.4 parts by mass or less with respect to the total amount of 100 parts by mass of the above propylene-based polymer (A) and the above ethylene-α-olefin copolymer (B).

[0060] The resin composition containing a crystal nucleating agent has a high solidification rate of the melt curtain after melt extrusion and excellent high-speed moldability. In addition, a molded article with excellent transparency can be obtained. Furthermore, the resin composition containing a crystal nucleating agent tends to have a lower melt tension compared to the resin composition not containing a crystal nucleating agent. The resin composition of the present invention can contain, as needed, known additives such as antioxidants, ultraviolet absorbers, neutralizing agents, light stabilizers, antistatic agents, antiblocking agents, lubricants, odor adsorbents, antibacterial agents, pigments, inorganic and organic fillers, and various synthetic resins, in addition to the above crystal nucleating agent, as long as the object of the present invention is not impaired.

[0061] The resin composition of the present invention can be used alone as a resin composition, for example, in a known thermoforming method such as calendering, extrusion molding, injection molding, inflation molding, blow molding, extrusion blow molding, injection blow molding, press molding, vacuum molding, foam molding, etc., to be used for, for example, sheets, films, hollow molded articles, etc. In addition, the resin composition of the present invention can also be laminated (bonded) with a substrate to form a laminate.

[0062] <Substrate> The substrate that can be laminated with the resin composition of the present invention is not particularly limited. For example, as long as it is in the form of a sheet, film, tray or container and can be used as a laminate, it is not particularly limited. Examples of the substrate include films made of polyesters typified by polyethylene terephthalate and polyethylene naphthalate, polycarbonate films, polyamide films made of nylon 6, nylon 66, etc., ethylene-vinyl alcohol copolymer films, polyvinyl alcohol films, polyvinyl chloride films, polyvinylidene chloride films, etc. thermoplastic resin films, or sheets made of these thermoplastic resins, and further, trays or cup-shaped containers obtained by thermoforming the sheets, and those shaped objects composed of aluminum foils, papers, etc.

[0063] Also, the thermoplastic resin film may be an unstretched film, or a uniaxially or biaxially stretched film. When the substrate is a thermoplastic resin, the resin composition of the present invention and the thermoplastic resin can be co-extrusion molded into a laminate, or the resin composition of the present invention can be extrusion coated (extrusion lamination) onto a previously obtained film or sheet of the thermoplastic resin to form a laminate. A laminate can be obtained by various known methods such as laminating a previously obtained film or sheet of a thermoplastic resin and a film or sheet of the resin composition of the present invention (by dry lamination). Among the methods for obtaining a laminate, the method of co-extrusion molding the resin composition of the present invention and the thermoplastic resin into a laminate is preferred.

[0064] 《Uses》 The laminate containing the resin composition of the present invention has various known uses, for example, in the food field such as food packaging films and food containers such as cups, bottles, trays, tubes, BIB (bag-in-box), etc., and in non-food fields. Also, when using films made of polyesters typified by polyethylene terephthalate and polyethylene naphthalate, polycarbonate films, polyamide films made of nylon 6, nylon 66, etc., ethylene-vinyl alcohol copolymer films, polyvinyl alcohol films as the substrate, it also has excellent gas barrier properties.

[0065] (Packaging material) The laminate containing the resin composition of the present invention can also be used as a packaging material. As the packaging material, it is preferably used as a material (packaging material) for packaging containers and packaging bags such as food and beverage products, cosmetics, miscellaneous goods, food packaging, filling packaging, and fiber packaging.

[0066] The packaging container and the packaging bag may be obtained by vacuum forming or pressure air forming a film-like or sheet-like laminate into a desired shape, or may be obtained by manufacturing the laminate so as to have the shape of a desired packaging container and packaging bag.

[0067] The packaging container and the packaging bag for packaging the contents can be obtained, for example, by filling the container and the bag with the contents, and then covering the container with a known film as a lid material and heat-sealing the upper part or the side part of the container. The container and the bag are preferably used for packaging instant noodles, miso, jelly, pudding, snack foods, etc.

Examples

[0068] Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples in any way. The propylene-based polymer (A) and the ethylene-α-olefin copolymer (B) used in the examples and comparative examples are shown below. Unless otherwise specified, these polyolefins were all prepared by polymerization according to a conventional method.

[0069] (1) Propylene-based polymer (A) The propylene-based polymer (A) used in the examples and comparative examples was prepared by appropriately mixing the following PP-1, PP-2, and modified PP.

[0070] (1-1) PP-1: Homopolypropylene (propylene homopolymer) MFR = 7 g / 10 min, density 0.90 g / cm 3 . (1-2) PP-2: Homopolypropylene (propylene homopolymer) MFR = 3 g / 10 min, density 0.90 g / cm 3 . (1 - 3) Modified PP: Maleic anhydride modified homopolypropylene MFR = 100 g / 10 min, density 0.90 g / cm 3 , maleic anhydride grafting amount 1.0 mass%.

[0071] (2) Ethylene·α-olefin copolymer (B) (2 - 1) EBR: Ethylene·1-butene copolymer MFR = 4 g / 10 min, density 0.89 g / cm 3 , ethylene content = 88 mol%, 1-butene content = 12 mol%. As the crystal nucleating agent, Milliken's product name: Millad NX8000 (nonitol-based crystal nucleating agent) was used.

[0072] [Measurement conditions for physical properties] <Melt flow rate (MFR)> In accordance with ASTM D 1238, for propylene-based polymers, the MFR was measured at 230°C under a load of 2.16 kg, and for ethylene-based polymers, the MFR was measured at 190°C under a load of 2.16 kg.

[0073] <Density> The density was measured in accordance with JIS K7112 (density gradient tube method). <Composition of ethylene·α-olefin copolymer> Quantification of the content ratio of the structural units derived from α-olefin and the structural units derived from ethylene in the ethylene·α-olefin copolymer was 13 performed by C-NMR using the following apparatus and conditions.

[0074] Using a JEOL JECX400P type nuclear magnetic resonance apparatus manufactured by JEOL Ltd., a mixed solvent of deuterated orthodichlorobenzene / deuterated benzene (80 / 20 vol%) was used as the solvent, the sample concentration was 60 mg / 0.6 mL, the measurement temperature was 120°C, and the observed nucleus was 13C (100 MHz), the sequence was single - pulse proton decoupling, the pulse width was 4.62 μs (45° pulse), the repetition time was 5.5 s, the number of accumulations was 8000 times, and the condition with 29.73 ppm as the reference value of the chemical shift was adopted.

[0075] <Crystallization temperature and melting point> The crystallization temperature and melting point were measured as follows using a differential scanning calorimeter (DSC). About 5 mg of the sample was sealed in an aluminum pan, heated from room temperature to 230 °C at 10 °C / min, and the sample was held at 230 °C for 10 minutes to completely melt it. Then it was cooled to - 20 °C at 10 °C / min, left at - 20 °C for 10 minutes, and then the sample was heated again to 230 °C at 10 °C / min. The peak temperature detected in the cooling test was adopted as the crystallization temperature (Tc), and the peak temperature in this second heating test was adopted as the melting point (Tm).

[0076] <Amount of graft modification> The amount of the structural unit derived from the unsaturated carboxylic acid and / or its derivative (amount of graft modification) was measured by an infrared absorption analyzer for the intensity of the peak derived from the said structural unit (1790 cm when maleic anhydride was used -1 ), and quantified using a calibration curve prepared in advance.

[0077] 〈Film formability〉 The resin compositions obtained in the examples and comparative examples obtained by the following method were extruded at 240 °C using an extrusion molding machine with a T - die (film molding machine) using a screw with a diameter of 40 mm and an effective length L / D = 26, and taken up by a chill roll set at 25 °C to form a single - layer 40 - μm film. Single - layer films were formed under three conditions of take - up speeds of 5 m / min, 10 m / min, and 20 m / min, and the formability was judged according to the following two criteria.

[0078] Pulsation of the melt resin film extruded from the T - die Formability 〇: No pulsation occurs in the film width direction Formability △: Slight pulsation occurs in the film width direction Formability ×: Pulsation occurs in the film width direction Adhesion to the chill roll Moldability 〇: No peeling marks occur on the film surface when passing through the chill roll Moldability △: Slight peeling marks occur on the film surface when passing through the chill roll Moldability ×: Obvious peeling marks occur on the film surface when passing through the chill roll

[0079] 〈Production of the laminate〉 Using a three - type three - layer T - die forming machine (multilayer film forming machine), by co - extrusion molding, a laminate (laminated film) composed of ethylene - vinyl alcohol copolymer (Eval F101A manufactured by Kuraray Co., Ltd., MFR (190 °C, 2.16 kg) = 1.6 g / 10 min), the resin compositions obtained in the examples and comparative examples, and polypropylene (Prime Polypro F327 manufactured by Prime Polymer Co., Ltd., MFR = 7) was produced. The ethylene - vinyl alcohol copolymer was extruded at 220 °C using a screw with a diameter of 40 mm and an effective length L / D = 26, the resin composition was extruded at 240 °C using a screw with a diameter of 40 mm and an effective length L / D = 26, and polypropylene was extruded at 240 °C using a screw with a diameter of 50 mm and an effective length L / D = 28. The set temperature of the T - die was 220 °C. By appropriately adjusting the screw rotation speed, a laminate with ethylene - vinyl alcohol copolymer / resin composition / polypropylene = 40 / 40 / 160 μm was produced at a take - up speed of 5 m / min.

[0080] 〈Adhesion of the laminate〉 The adhesion (unit: N / 15 mm) of the obtained laminate was measured at room temperature of 23 °C by the T - peel method using a tensile testing machine. The cross - head speed was 300 mm / min.

[0081] [Example 1] As the propylene - based polymer (A), the above - mentioned PP - 1 (60 parts by mass), the above - mentioned PP - 2 (36 parts by mass) and the above - mentioned modified PP (4 parts by mass) were melt - kneaded at 230 °C using a single - screw extruder to obtain Resin Composition 1. The graft modification amount of the propylene - based polymer (A) in Resin Composition 1 is 0.04% by mass.

[0082] [Examples 2 to 5 and Comparative Examples 1 to 3] In Examples 2 to 5 and Comparative Examples 1 to 3, resin compositions were produced in the same manner as in Example 1 according to the formulation shown in Tables 1 to 2, respectively.

[0083] The composition obtained in Example 2 was designated as Resin Composition 2, and the amount of graft modification of the propylene-based polymer (A) in Resin Composition 2 was 0.08% by mass. The composition obtained in Example 3 was designated as Resin Composition 3, and the amount of graft modification of the propylene-based polymer (A) in Resin Composition 3 was 0.04% by mass. The composition obtained in Example 4 was designated as Resin Composition 4, and the amount of graft modification of the propylene-based polymer (A) in Resin Composition 4 was 0.04% by mass. The composition obtained in Example 5 was designated as Resin Composition 5, and the amount of graft modification of the propylene-based polymer (A) in Resin Composition 5 was 0.09% by mass.

[0084] The composition obtained in Comparative Example 1 was designated as Resin Composition 6, and the amount of graft modification of the propylene-based polymer (A) in Resin Composition 6 was 0.04% by mass. The composition obtained in Comparative Example 2 was designated as Resin Composition 7, and the amount of graft modification of the propylene-based polymer (A) in Resin Composition 7 was 0.04% by mass. The composition obtained in Comparative Example 3 was designated as Resin Composition 8, and the amount of graft modification of the propylene-based polymer (A) in Resin Composition 8 was 0.04% by mass.

[0085] The MFR, density, melting point, crystallization temperature of the resin compositions obtained in the examples and comparative examples, the results of the formability evaluation of the single-layer film of this resin composition, and the results of the adhesion evaluation of the laminate obtained from this resin composition are shown in Tables 1 to 2.

[0086] [Table 1]

[0087] [Table 2]

Claims

1. A resin composition containing 100 parts by mass of a propylene-based polymer (A) satisfying the following requirements (a-1) to (a-3) [provided that the total of (A) and a copolymer (B) of ethylene and at least one α-olefin selected from α-olefins having 3 to 20 carbon atoms satisfying the following requirements (b-1) and (b-2) is 100 parts by mass.], wherein at least a part of the propylene-based polymer (A) is modified with a polar compound, and the polar compound is an unsaturated carboxylic acid or a derivative thereof, the propylene-based polymer (A) consists only of a propylene-based polymer modified with a polar compound or is a mixture of a propylene-based polymer modified with a polar compound and an unmodified propylene-based polymer, and the amount of modification of the polar compound in the propylene-based polymer modified with the polar compound is 0.01 to 1% by mass. In the case of the mixture, the amount of modification of the polar compound in the mixture is 0.01 to 1% by mass, and the resin composition is characterized by satisfying the following requirements (1) to (3). (a-1) The melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg is in the range of 1 to 100 g / 10 min, (a-2) having a density in the range of 0.89 to 0.93 g / cm 3 in the range of (a-3) The melt tension measured at 230°C is 10 mN or less, (b-1) The content of the structural unit derived from ethylene is 50 to 99 mol%, and the content of the structural unit derived from an α-olefin having 3 to 20 carbon atoms is 1 to 50 mol% (provided that the total of the content of the structural unit derived from ethylene and the content of the structural unit derived from an α-olefin is 100 mol%).), (b-2) The melt flow rate (MFR; 190°C, 2.16 kg load) measured by ASTM D 1238 is in the range of 0.1 to 50 g / 10 min. (1) The melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg is in the range of 1 to 100 g / 10 min, (2) having a density in the range of 0.89 to 0.93 g / cm 3 ; (3) The melt tension measured at 230°C is 10.0 mN or less.

2. 75 parts by mass or more and less than 100 parts by mass of a propylene-based polymer (A) satisfying the following requirements (a-1) to (a-3), A copolymer (B) of ethylene and at least one α-olefin selected from α-olefins having 3 to 20 carbon atoms, which satisfies the following requirements (b-1) and (b-2), is more than 0 part by mass and 25 parts by mass or less [however, the total of (A) and (B) is 100 parts by mass.], and a resin composition containing a crystal nucleating agent, the propylene-based polymer (A) is at least partially modified with a polar compound, and the polar compound is an unsaturated carboxylic acid or a derivative thereof, the content of the crystal nucleating agent is 0.4 part by mass with respect to the total amount of 100 parts by mass of the propylene-based polymer (A) and the ethylene / α-olefin copolymer (B), and the resin composition is characterized by satisfying the following requirements (1) to (3). (a-1) The melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg is in the range of 1 to 100 g / 10 min, (a-2) having a density in the range of 0.89 to 0.93 g / cm 3 in the range of (a-3) The melt tension measured at 230°C is 10 mN or less, (b-1) The content of the structural unit derived from ethylene is 50 to 99 mol%, and the content of the structural unit derived from an α-olefin having 3 to 20 carbon atoms is 1 to 50 mol% (however, the total of the content of the structural unit derived from ethylene and the content of the structural unit derived from an α-olefin is 100 mol%).), (b-2) The melt flow rate (MFR; 190°C, 2.16 kg load) measured by ASTM D 1238 is in the range of 0.1 to 50 g / 10 min. (1) The melt flow rate (MFR) measured at a temperature of 230°C and a load of 2.16 kg is in the range of 1 to 100 g / 10 min, (2) having a density in the range of 0.89 to 0.93 g / cm 3 inclusive; (3) The melt tension measured at 230°C is 10.0 mN or less.

3. The resin composition according to claim 1, wherein the resin composition contains a crystal nucleating agent.

4. The resin composition according to claim 3, wherein the content of the crystal nucleating agent is 0.4 part by mass or less with respect to 100 parts by mass of the propylene-based polymer (A).

5. The resin composition according to any one of claims 2 to 4, wherein the crystal nucleating agent is a nonitol-based crystal nucleating agent.

6. The resin composition according to claim 2, wherein the resin composition contains 90 parts by mass or more and less than 100 parts by mass of the propylene-based polymer (A) and more than 0 part by mass and 10 parts by mass or less of the copolymer (B) [however, the total of (A) and (B) is 100 parts by mass.].

7. The resin composition according to any one of claims 1 to 6, wherein the amount of the propylene-based polymer modified with a polar compound in the propylene-based polymer (A) is in the range of 1 to 25% by mass.

8. The resin composition according to any one of claims 1 to 7, wherein the melt tension measured at 250 ° C is 7.0 mN or less.

9. The resin composition according to any one of claims 1 to 8, wherein the crystallization peak derived from the propylene-based polymer (A) when measured by a differential scanning calorimeter (DSC) is in the range of 120 to 135 ° C.

10. The resin composition according to any one of claims 1 to 9, wherein the difference between the crystallization peak derived from the propylene-based polymer (A) and the melting peak derived from the propylene-based polymer (A) when measured by a differential scanning calorimeter (DSC) represented by the following formula is 35 ° C or more. (Melting peak (° C) derived from propylene-based polymer (A)) - (Crystallization peak (° C) derived from propylene-based polymer (A))

11. A laminate having a layer containing the resin composition according to any one of claims 1 to 10.

12. The laminate according to claim 11, wherein the laminate is a film for food packaging.

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