Polypropylene-based packaging material

Abstract

The present application relates to a polypropylene packaging material composed of an ethylene-propylene block copolymer having a resin having polypropylene as a main component as a matrix, a phase dispersion structure in which a polypropylene elastomer in a spindle shape becomes a domain, and capable of providing a packaging material having all of low-temperature drop impact resistance, blocking resistance, sliding property, and flavor.

Description

Technical Field

[0001] This invention relates to a polypropylene-based packaging material, and more specifically, to a polypropylene-based packaging material having drop impact resistance, anti-sticking properties, slip resistance, and flavor properties, preferably suitable for food packaging, and a laminate having a surface layer composed of the packaging material. Background Technology

[0002] Packaging materials made of propylene polymers exhibit excellent heat-sealing properties, heat resistance, hygiene, and flavor, making them widely used for packaging various foods. In recent years, from the perspectives of lightweighting and economy, the trend towards thinner-walled packaging containers is underway. Furthermore, to cope with use in cold regions, there is a need for improved low-temperature impact resistance, requiring even higher levels of impact resistance. Propylene block copolymers, known as impact polypropylene, are also used in packaging materials due to their high impact resistance.

[0003] In addition, other properties required for packaging materials include anti-blocking properties. That is, the films need to be resistant to sticking together when they are bonded together. However, the films made of the aforementioned propylene block copolymers lack anti-blocking properties due to the presence of soft rubber components, and further modification is desired. To improve properties such as resistance to falling impacts and resistance to adhesion, for example, Patent Document 1 below proposes an propylene-based resin composition which is formed by combining an ethylene / α-olefin copolymer with a propylene block copolymer.

[0004] Furthermore, in Patent Document 2 below, a multilayer film is proposed that uses a polypropylene block copolymer and has a surface layer composed of generally spherical elastomer particles dispersed therein. Existing technical documents Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-161033 Patent Document 2: Japanese Patent Application Publication No. 2006-198977 Summary of the Invention The problem that the invention aims to solve

[0006] In containers such as trays and cups, container forming, filling / sealing of contents, and packaging are carried out continuously while being transported on a conveyor line. Therefore, it is necessary to have good conveying properties, i.e., smoothness, to prevent container blockage on the production line. Excellent smoothness is also required in polypropylene packaging materials. In addition, in food applications, it is particularly important not to impair the flavor of the contents. However, the packaging materials using propylene block copolymers described in Patent Documents 1 and 2 above cannot fully meet all the requirements for drop impact resistance, anti-sticking properties, and slip resistance under low-temperature conditions. Furthermore, it is difficult to provide packaging materials that also possess these properties along with aesthetic characteristics and flavor.

[0007] Therefore, the object of the present invention is to provide a polypropylene-based packaging material that combines the properties of drop impact resistance, anti-adhesion, slip resistance, and flavor under low temperature conditions, as well as a laminate having the packaging material as a surface layer. Technical solution

[0008] According to the present invention, a polypropylene-based packaging material is provided, characterized in that it is an ethylene-propylene block copolymer having a phase dispersion structure in which a polypropylene-based elastomer with a spindle shape forms the structural domain, with the resin as the main component being polypropylene as the matrix.

[0009] The following are preferred contents in the packaging materials of the present invention. [1] The aspect ratio of the structural domain is in the range of 1.2 to 9.0. [2] The short axis of the structural domain is in the range of 0.2 to 4.0 μm, and the long axis is in the range of 0.5 to 5.0 μm. [3] The polypropylene elastomer contains 1 to 30 parts by mass of the polypropylene-based elastomer relative to 100 parts by mass of the resin with polypropylene as the main component. [4] The weight-average molecular weight (Mw) of the polypropylene elastomer is 500,000 to 1,000,000, and the number-average molecular weight (Mn) is 10,000 to 300,000. [5] The weight-average molecular weight (Mw) of the resin with polypropylene as the main component is 300,000 to 800,000, and the number-average molecular weight (Mn) is 10,000 to 300,000. [6] The homopolymer contains 1 to 30 parts by mass of homopolymer relative to 100 parts by mass of the ethylene-propylene block copolymer. [7] The surface roughness (Sa) is 0.15 to 1.0 μm. [8] It can be any shape of sheet, film, tray, or cup.

[0010] Furthermore, according to the present invention, a laminate is provided, characterized in that it is a laminate having a polypropylene layer as a surface layer, wherein the polypropylene layer is composed of an ethylene-propylene block copolymer as the aforementioned polypropylene-based packaging material, and the surface roughness Sa of the polypropylene layer is 0.15 to 1.0 μm.

[0011] In the laminate of the present invention, the following are preferred. [1] It shall have at least the following: the polypropylene layer as the inner layer and the outer layer, and an oxygen-absorbing layer and a gas-barrier layer as the intermediate layer. [2] It has the shape of a tray or cup.

[0012] Furthermore, according to the present invention, a method for manufacturing a laminate is provided, characterized in that it is a method for manufacturing a laminate having a polypropylene layer as a surface layer, wherein the polypropylene layer is composed of an ethylene-propylene block copolymer, wherein homopolymer polypropylene as a viscosity modifier is incorporated into the ethylene-propylene block copolymer, the MFR (230°C, 2.16 kg load) viscosity is adjusted to the range of 0.1 to 10 g / 10 min, and the viscosity-adjusted molten resin is extruded, thereby forming a surface layer with a surface roughness of 0.15 μm to 1.0 μm.

[0013] In the manufacturing method of the laminate of the present invention, the following is preferred. [1] 1 to 30 parts by weight of the homopolymer are added relative to 100 parts by weight of the ethylene-propylene block copolymer. [2] The polypropylene elastomer contains 1 to 30 parts by mass relative to 100 parts by mass of the ethylene-propylene block copolymer. [3] The weight-average molecular weight (Mw) of the polypropylene elastomer is 500,000 to 1,000,000, and the number-average molecular weight (Mn) is 10,000 to 300,000. [4] The weight-average molecular weight (Mw) of the resin with polypropylene as the main component is 300,000 to 800,000, and the number-average molecular weight (Mn) is 10,000 to 300,000. Invention Effects

[0014] The packaging material of the present invention has a resin matrix with polypropylene as the main component, and a spindle-shaped polypropylene elastomer as a dispersed structure of structural domains. By controlling the shape and size of the spindle-shaped structural domains, excellent drop impact resistance as well as sliding and anti-adhesion properties can be achieved. In addition, excellent flavor can be achieved by using specific polypropylene-based elastomers.

[0015] Furthermore, in the laminate of the present invention, by using the aforementioned polypropylene-based packaging material as the surface layer, the surface roughness (Sa) of which is 0.15 to 1.0 μm, excellent drop impact resistance, as well as a balance between slippage and anti-sticking properties, are achieved. In addition, in the laminate of the present invention, by using a propylene-based polymer with a molecular weight within the aforementioned range, excellent flavor is also achieved. Furthermore, in the method for manufacturing the laminate of the present invention, by combining homopolymer polypropylene, the viscosity of the ethylene-propylene block copolymer can be adjusted to a viscosity suitable for molding, thereby improving the moldability (workability) without compromising the impact resistance of the laminate. Attached Figure Description

[0016] Figure 1 This is a diagram used to illustrate the shape of the structural domains in the packaging material of the present invention. Detailed Implementation

[0017] (Polypropylene packaging materials) As described above, an important feature of the packaging material of the present invention is that it has a phase dispersion structure in which a polypropylene-based elastomer with a spindle shape forms a structural domain, with a resin as the main component being polypropylene. In this invention, the drop impact resistance is further improved by dispersing spindle-shaped structural domains composed of polypropylene elastomers in a matrix composed of a resin with polypropylene as the main component. Furthermore, by controlling the dispersion particle size of the structural domains composed of the rubber component, not only drop impact resistance can be achieved, but also slip resistance and anti-adhesion properties can be taken into account. In other words, in packaging materials using propylene block copolymers, to exhibit excellent drop impact resistance even at low temperatures, it is preferable to have a high content of rubber component (polypropylene-based elastomer), and the structural domains (dispersed particles) formed by this rubber component are also micro-dispersed, considering not only drop impact resistance but also appearance characteristics. On the other hand, to improve anti-blocking and slip resistance, it is preferable to have a low content of rubber component, and the size of the dispersed particles formed by this rubber component is such that they can form unevenness on the surface. In this invention, from the viewpoint of this invention, it has been found that by having a dispersion structure in which spindle-shaped structural domains composed of polypropylene elastomers are formed in a matrix composed of a resin mainly composed of polypropylene, excellent drop impact resistance as well as anti-adhesion and sliding properties can be achieved.

[0018] In this invention, to demonstrate the excellent drop impact resistance provided by the structural domains composed of polypropylene elastomers, the spindle-shaped structural domains are preferably spindle-shaped with an aspect ratio in the range of 1.2–9.0, 1.2–8.0, 1.9–8.0, and particularly 1.9–5.0. While a larger aspect ratio results in better drop impact resistance, it also tends to have poor slip resistance. Furthermore, the structural domains preferably have a minor axis in the range of 0.2–4.0 μm, particularly preferably in the range of 0.2–2.0 μm, and a major axis in the range of 0.5–5.0 μm, particularly preferably in the range of 0.5–3.0 μm. It should be noted that the methods for measuring the minor and major axes of the structural domains will be described later. Furthermore, the size of the equivalent circle's structural domain is preferably in the range of 0.5 μm to 5.0 μm, and particularly preferably in the range of 0.5 μm to 1.0 μm. When the size of the structural domain is too small, no surface unevenness is formed, resulting in poor sliding performance. When the size of the structural domain is too large, unevenness is formed, resulting in good sliding performance, but there is a tendency for poor resistance to drop impact.

[0019] The control of the shape and size of the structural domains is determined by the resin with polypropylene as the main component as the matrix and the molecular weight, composition, and compounding of the polypropylene elastomer. In the packaging material of the present invention, a polypropylene-based elastomer is preferably contained in an amount of 1 to 30 parts by weight, and particularly preferably 5.0 to 25 parts by weight, relative to 100 parts by weight of resin with polypropylene as the main component. When the amount of polypropylene-based elastomer is less than the above range, the drop impact resistance may not be sufficiently improved compared to the case within the above range. On the other hand, when the amount of polypropylene-based elastomer is more than the above range, compared to the case within the above range, not only are the anti-sticking and slippage properties reduced, but the flavor is also reduced, and the surface roughness is increased, resulting in poorer appearance characteristics.

[0020] [Resin with polypropylene as the main component] In the packaging material of the present invention, the resin that forms the matrix and is mainly composed of polypropylene is homopolymer or atactic polypropylene polymerized from monomers mainly composed of propylene. The weight-average molecular weight (Mw) of the resin with polypropylene as the main component is preferably in the range of 300,000 to 800,000, particularly preferably in the range of 300,000 to 600,000, and the number-average molecular weight (Mn) is preferably in the range of 10,000 to 300,000, particularly preferably in the range of 50,000 to 200,000. When the molecular weight of the resin with polypropylene as the main component is lower than the above ranges, compared to the case where it is within the above ranges, the drop impact resistance and hygiene may be reduced. On the other hand, when the molecular weight of the resin with polypropylene as the main component is higher than the above ranges, compared to the case where it is within the above ranges, the moldability may be reduced due to abnormal resin pressure. Furthermore, from the viewpoints of heat resistance and moldability, the mesoopentad fraction ([mmmm]), which is an indicator of stereoregularity, of the resin with polypropylene as the main component is preferably in the range of 95 to 99.

[0021] [Polypropylene Elastomers] In the packaging material of the present invention, polypropylene-based elastomers constituting the spindle-shaped structural domains can be exemplified by, for example, propylene-ethylene elastomers. As propylene-ethylene elastomers, random copolymers of propylene and ethylene with a mass ratio of ethylene units to propylene units in the range of 15:85 to 50:50 are preferred. Furthermore, elastomers copolymerized with α-olefins, etc., may be used as needed to improve compatibility and drop impact resistance. Ideally, the weight-average molecular weight (Mw) of the polypropylene elastomer is in the range of 500,000 to 1,000,000, preferably 650,000 to 1,000,000, more preferably 700,000 to 1,000,000, and particularly preferably 700,000 to 900,000; the number-average molecular weight (Mn) is in the range of 10,000 to 300,000, preferably 20,000 to 200,000, and particularly preferably 100,000 to 200,000. When the molecular weight is smaller than the above ranges, compared to the ranges, the structural domains become prismatic, the particle size is small, resulting in microdispersion, and the surface of the container becomes smooth, which may fail to meet the requirements for anti-blocking and slippage properties. On the other hand, when the molecular weight is larger than the above ranges, the structural domains become approximately spherical, the particle size is large, resulting in loose dispersion, and therefore the resistance to impact during drops may be poor. Furthermore, there is a tendency for a decrease in flavor. Therefore, by controlling the mass ratio and molecular weight of the ethylene and propylene units in the polypropylene elastomer, as well as the molecular weight of the resin with polypropylene as the main component, the structural domains of the polypropylene elastomer can be elongated to a spindle shape with the aforementioned aspect ratio, and the compatibility between the two can be improved. With the aforementioned micro-dispersion, drop impact resistance as well as anti-adhesion and sliding properties can be achieved.

[0022] Regarding the spindle shape of the polypropylene elastomer of the present invention, the following speculation is made. In containers such as films, sheets, cups, and trays produced through secondary processing, the resin is stretched in the extrusion (molding) direction. Therefore, the shape of the structural domains in the resin also follows, becoming thinner at the leading edge in the extrusion direction, resulting in a spindle shape. Figure 1 The spindle shape is shown. However, it can be assumed that the shape of the domain varies depending on the molecular weight of the matrix and the domain, the molecular weight of the domain itself, and the compatibility between the matrix and the domain. For example, when the molecular weight of the domain is low and the compatibility between the domain and the matrix is ​​high, it becomes prismatic with low surface roughness and smoothness, thus suggesting poor sliding properties. On the other hand, when the molecular weight of the domain is high and the compatibility between the domain and the matrix is ​​low, it becomes roughly spherical, suggesting poor resistance to drop impact. It should be noted that compatibility is affected by the composition of the polypropylene elastomer and the addition of ethylene-α-olefin copolymers, etc.

[0023] [Ethylene-propylene block copolymer] MFR (230°C, 2.16 kg load) of ethylene-propylene block copolymers with a phase dispersion structure of polypropylene elastomers in a spindle shape as the structural domain, with a resin matrix of polypropylene as the main component, is preferred for molding in the range of 0.1 to 10 g / 10 min, particularly 0.2 to 5 g / 10 min. Furthermore, the raw materials or a portion thereof for resins and polypropylene-based elastomers with polypropylene as the main component can be derived not only from petroleum, but also from ethylene-propylene block copolymers made from materials chemically recycled from waste plastics through monomerization technologies such as gasification and oil extraction, or from biomass materials derived from plants. Biomass quality can be measured using methods such as radiocarbon dating. Moreover, when manufacturing resins and polypropylene-based elastomers with polypropylene as the main component, from the perspective of reducing environmental impact, it is ideal to manufacture them in a catalyst system that does not use SVHC substances (Substances of Very High Concern) such as phthalate compounds during the polymerization stage from the raw material stage.

[0024] [Other ingredients] In the packaging material of the present invention, in addition to the ethylene-propylene block copolymer described above, homopolymer polypropylene is preferably incorporated as a viscosity modifier. In other words, for resins with polypropylene as the main component and resin compositions composed of polypropylene-based elastomers, in order to balance drop impact resistance and sliding properties, there is a tendency for polypropylene-based elastomers to have high molecular weights, sometimes resulting in high viscosity and poor formability. Therefore, by adjusting the viscosity by compounding homopolymer, the extrudability of the molten resin can be improved, and the formability (workability) can be improved without compromising the drop impact resistance of the packaging material. From the perspective of viscosity adjustment, the MFR (230°C, 2.16 kg load) of homopolymer polypropylene is preferably in the range of 0.5 to 20 g / 10 min. The homopolymer polypropylene is preferably added in an amount of 1 to 40 parts by weight, and particularly preferably 1 to 30 parts by weight, relative to 100 parts by weight of the ethylene-propylene block copolymer.

[0025] Furthermore, in the packaging material of the present invention, to further improve drop impact resistance, rubber components such as high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and other ethylene-α-olefin copolymers, elastomers, and plasmons can be added. Moreover, to improve slip resistance, lubricants such as calcium stearate and anti-blocking agents such as silica particles can be added in combination with the aforementioned rubber components. Small amounts of known additives such as antioxidants can also be added as needed. Due to the increasing environmental concerns in recent years, it is also important to combine waste plastics with materials that have undergone chemical recycling through monomerization technologies such as gasification and oil extraction, or biomass materials derived from plants, as part of the deplasticization process.

[0026] (Preparation of polypropylene-based packaging materials) The packaging materials of the present invention can be prepared by known methods such as melt extrusion or melt mixing of their particles using a mixer. In this invention, in order to make the structural domains of the polypropylene elastomer dispersed in a spindle shape with the aforementioned size and aspect ratio, melt mixing is required, and the mixing conditions need to be appropriately adjusted according to the viscosity of the resin used. There are no particular restrictions on the temperature conditions during melt mixing, but it is preferably carried out in the range of 170 to 270°C. At temperatures lower than the above range, mixing may not be efficient, and at temperatures higher than the above range, resin deterioration may occur.

[0027] The packaging material of the present invention can be formed into desired shapes such as films, sheets, tubes, etc. by known manufacturing methods such as extrusion molding or injection molding of melt-mixed resin, or the obtained sheet can be formed into shapes such as cups and trays by thermoforming. The surface roughness (Sa) of the packaging material of the present invention is preferably in the range of 0.15 to 1.0 μm. This allows for excellent anti-sticking and anti-slip properties without compromising appearance characteristics. It should be noted that surface roughness (Sa) is a parameter extending the arithmetic mean height of a line (Ra) to a surface, and is the average of the absolute values ​​of the differences in height between points relative to the average surface area, as specified in ISO 25178.

[0028] (Layered structure) In this invention, the molded body may be a single layer of a resin composition consisting of the above-mentioned ethylene-propylene block copolymer, or it may be a multilayered body having other layers. In the case of such a multilayer structure, the polypropylene layer composed of the ethylene-propylene block copolymer resin composition is preferably the surface layer (outermost or innermost layer), and is particularly ideally the outermost layer. That is, by having a dispersion structure in which spindle-shaped structural domains composed of polypropylene elastomers are dispersed in a matrix composed mainly of polypropylene in the surface layer of the laminate, the drop impact resistance is further improved, exhibiting excellent drop impact resistance even at low temperatures, and by having a surface roughness within the aforementioned range, excellent sliding and anti-adhesion properties are exhibited.

[0029] [Multi-layer structure] In the laminate of the present invention, it is important that the aforementioned polypropylene layer is the surface layer (outermost or innermost layer), at least the outermost layer, and preferably both the outermost and innermost layers. As long as the surface layer is composed of a polypropylene layer, various multilayer structures can be formed, and it is preferable to have other conventionally known layers such as a gas barrier layer, an oxygen absorption layer, an adhesive layer, a refrigerant layer, or an adsorbent layer as intermediate layers. The laminates of the present invention are not limited thereto; the following layer configurations can be exemplified. Examples include: polypropylene layer (outermost layer) / adhesive layer / gas barrier layer / adhesive layer / polypropylene surface layer (innermost layer), polypropylene layer (outermost layer) / adhesive layer / gas barrier layer / adhesive layer / oxygen absorbent layer / polypropylene layer (innermost layer), polypropylene layer (outermost layer) / adhesive layer / gas barrier layer / adhesive layer / oxygen absorbent layer / adhesive layer / gas barrier layer / adhesive layer / polypropylene layer (innermost layer), polypropylene layer (outermost layer) / recycled material layer / adhesive layer / gas barrier layer / adhesive layer / oxygen absorbent layer / polypropylene layer (innermost layer), polypropylene layer (outermost layer) / recycled material layer / adhesive layer / gas barrier layer / adhesive layer / polypropylene surface layer (innermost layer), polypropylene layer (outermost layer) / recycled material layer / adhesive layer / gas barrier layer / oxygen absorbent layer with gas barrier resin as the base resin / gas barrier layer / adhesive layer / layer containing adsorbent / polypropylene layer (innermost layer), etc. It should be noted that the innermost layer can be changed to the aforementioned polypropylene layer, or, in addition to the aforementioned polypropylene layer, it can also be made into a layer composed of an easily peelable resin.

[0030] In the laminate of the present invention, the thickness of each layer varies depending on the shape of the laminate, the manufacturing method, etc., and cannot be specified in general. When the laminate is a film or sheet, the thickness of the polypropylene surface layer (outermost layer) is preferably in the range of 5 to 800 μm, particularly preferably in the range of 5 to 500 μm, and the thickness of the polypropylene surface layer (innermost layer) is preferably in the range of 5 to 800 μm, particularly preferably in the range of 5 to 500 μm. Furthermore, regarding the thickness of other layers, when the outermost and innermost layers are within the above-mentioned thickness ranges, the gas barrier layer (total thickness in the case of multiple layers) is preferably in the range of 5 to 500 μm, particularly preferably in the range of 5 to 200 μm, and the oxygen absorption layer is preferably in the range of 5 to 500 μm, particularly preferably in the range of 5 to 200 μm. Furthermore, when a recycled material layer is provided, it is preferably formed in the range of 50 to 1000 μm, particularly preferably in the range of 50 to 800 μm. Furthermore, when an adsorbent layer is provided, it is preferably formed in the range of 5 to 500 μm, and particularly preferably in the range of 5 to 300 μm.

[0031] Furthermore, when the laminate of the present invention is a multi-layer container (cup, tray, etc.) formed by thermoforming such as air molding, in the main body portion that forms the thinnest wall of the multi-layer container, the thickness of the polypropylene surface layer (outermost layer) is preferably in the range of 1 to 160 μm, particularly preferably in the range of 1 to 100 μm, and the thickness of the polypropylene surface layer (innermost layer) is preferably in the range of 1 to 160 μm, particularly preferably in the range of 1 to 100 μm. Furthermore, regarding the thickness of other layers, when the outermost and innermost layers are within the aforementioned thickness ranges, the gas barrier layer (total thickness in the case of multi-layer formation) is preferably in the range of 1 to 100 μm, particularly preferably in the range of 1 to 40 μm, and the oxygen absorption layer is preferably in the range of 1 to 100 μm, particularly preferably in the range of 1 to 40 μm. Furthermore, when a recycled material layer is provided, it is preferably formed in the range of 10 to 200 μm, particularly preferably in the range of 10 to 160 μm. Furthermore, when an adsorbent layer is provided, it is preferably formed in the range of 1 to 100 μm, and particularly preferably in the range of 1 to 60 μm. Therefore, the effects of each layer, such as air barrier, oxygen absorption, or flavor, can be fully utilized without compromising drop impact resistance or formability.

[0032] [Gas barrier] In the laminate of the present invention, the gas barrier layer can use conventionally known barrier resins, and is particularly preferably composed of ethylene-vinyl alcohol copolymers. Regarding ethylene-vinyl alcohol copolymers, from the perspective of gas barrier properties, a copolymer saponified by saponifying an ethylene-vinyl acetate copolymer with an ethylene content of 20-60 mol%, particularly 25-50 mol%, to a saponification degree of 96% or more, particularly 99 mol% or more is preferred. In the present invention, it is particularly preferred to use a blend of an ethylene-vinyl alcohol copolymer with an ethylene content of 20-35 mol% and an ethylene-vinyl alcohol copolymer with an ethylene content of 36-50 mol% at a ratio (mass ratio) of 90:10-50:50, particularly 80:20-60:40. This maintains excellent gas barrier properties and improves moldability, thus enabling the lamination to be molded without appearance unevenness. The ethylene-vinyl alcohol copolymer should have a molecular weight sufficient to form a film, and ideally, it should have an intrinsic viscosity of 0.01 dl / g or higher, particularly 0.05 dl / g or higher, as measured typically at 30°C in a mixed solvent with a [phenol / water] mass ratio of 85 / 15.

[0033] In addition, examples of gas-barrier resins other than ethylene-vinyl alcohol copolymers include polyamides such as nylon 6, nylon 6.6, nylon 6 / 6.6 copolymer, poly(m-phenylene adipamide) (MXD6), nylon 6.10, nylon 11, nylon 12, and nylon 13. In these polyamides, the number of amide groups per 100 carbon atoms is preferably 5 to 50, and particularly preferably 6 to 20. These polyamides should also have a molecular weight sufficient to form a film; ideally, in concentrated sulfuric acid (concentration 1.0 g / dl), the relative viscosity measured at 30°C is 1.1 or higher, particularly 1.5 or higher. It should be noted that polyamide can be blended with ethylene-vinyl alcohol copolymer, and the preferred blending ratio (mass ratio) of ethylene-vinyl alcohol copolymer to polyamide is 50:50 to 99:1. Furthermore, in the case where polyamide is used as the matrix resin of the oxygen-absorbing resin composition as described below, the concentration of terminal amino groups is 40 eq / 10. 6 Polyamide resins with a content of more than g do not undergo oxidative degradation when absorbing oxygen, and are therefore ideal.

[0034] [Oxygen-absorbing layer] In the laminate of the present invention, the oxygen-absorbing layer may be composed of a resin composition in which the propylene polymer constituting the polypropylene layer, a known propylene polymer (hereinafter, they are sometimes referred to together as "propylene polymer"), a gas-barrier resin, or a recycled resin is used as the matrix resin, and the matrix resin contains an inorganic oxygen absorber or an organic oxygen absorber composed of (i) an oxidizing organic component and (ii) a transition metal catalyst (oxidation catalyst).

[0035] (Inorganic oxygen absorbent) Examples of inorganic oxygen absorbents include: iron powder, titanium dioxide, cerium oxide, ferrous salts, dithionites, sulfites, metal halides, and zeolites. Iron powder and metal halides are particularly desirable. Known iron powders such as reduced iron powder, atomized iron powder, electrolytic iron powder, and carbonyl iron powder can be used. Among these, reduced iron powder with a porous structure and large specific surface area is preferred, and rotary kiln reduced iron powder is particularly preferred. Rotary kiln reduced iron powder has high purity and a large specific surface area, thus exhibiting excellent oxygen absorption performance. One type of iron powder can be used, or two or more can be used in combination. The iron powder content in the oxygen absorbent is preferably 3 to 40 parts by mass relative to 100 parts by mass of the oxygen absorbent, more preferably 5 to 30 parts by mass.

[0036] Examples of metal halides include alkali metals, alkaline earth metals, copper, zinc, iron, etc. Specifically, examples include sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, potassium iodide, calcium chloride, magnesium chloride, barium chloride, etc. Sodium chloride is preferred. One or more of these metal halides may be used.

[0037] The amount of the halide metal is preferably 0.1 to 10 parts by mass relative to 100 parts by mass of iron powder, which is the main component of the oxygen absorber, and more preferably 1 to 5 parts by mass. Sufficient oxygen absorption performance can be obtained by adding 0.1 parts or more of halide metal relative to 100 parts by mass of iron powder. Furthermore, by adding less than 10 parts by mass of halide metal relative to 100 parts by mass of iron powder, the decrease in oxygen absorption performance caused by the reduction in iron powder content can be suppressed. In addition, poor appearance and adhesion of halide metal to the contents caused by halide metal leaching can be suppressed.

[0038] In addition to iron powder and metal halides, the oxygen absorbent of the present invention may also contain alkaline substances. By including alkaline substances, the amount of hydrogen generated by the reaction of iron with water can be reduced. Examples of such alkaline substances include: magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium carbonate, calcium carbonate, strontium carbonate, and barium carbonate. Among these, calcium hydroxide and calcium oxide, as a dehydrated product of calcium hydroxide, are preferred. One or more of these alkaline substances may be used.

[0039] (Organic oxygen absorber) (i) Oxidizing organic components As oxidizing organic components, polymers containing ethylene-based unsaturated groups can be listed. These polymers have carbon-carbon double bonds, and the double bond portion, particularly the α-methylene group adjacent to the double bond portion, is readily oxidized by oxygen, thereby capturing oxygen. Such polymers containing ethylene-based unsaturated groups can be used as oxidizing polymers, either homopolymers of polyenes derived from polyene monomers, or random copolymers or block copolymers combining two or more of the aforementioned polyenes or combining them with other monomers. Among the polymers derived from polyenes, polybutadiene (BR), polyisoprene (IR), natural rubber, nitrile rubber (NBR), styrene-butadiene rubber (SBR), chloroprene rubber, and ethylene-propylene-diene rubber (EPDM) are preferred, but are not limited to these.

[0040] In addition to using the polymers containing ethylene-based unsaturated groups mentioned above, polymers that are easily oxidized, such as polypropylene, ethylene / propylene copolymers, or poly(m-phenylene adipamide) with a terminal amino concentration of less than 40 eq / 106 g, can also be used as oxidizing organic components. It should be noted that, from the viewpoint of moldability, the viscosity of the above-mentioned oxidizing polymers and their copolymers at 40°C is preferably in the range of 1 to 200 Pa·s. These polyene polymers are preferably acid-modified polyene polymers that have incorporated carboxylic acid groups, carboxylic anhydride groups, and hydroxyl groups. The oxidizing organic components, which are composed of these oxidizing polymers or their copolymers, are preferably contained in the oxygen-absorbing resin in a proportion of 0.01 to 10% by mass.

[0041] (ii) Transition metal catalysts As a transition metal catalyst, group VIII metals such as iron, cobalt, and nickel are preferred. Other metals that can be used include group I metals such as copper and silver; group IV metals such as tin, titanium, and zirconium; group V metals such as vanadium; group VI metals such as chromium; and group VII metals such as manganese. Transition metal catalysts are typically used in the form of inorganic salts, organic salts, or complex salts of the aforementioned transition metals with lower valence numbers. Examples of inorganic salts include halides such as chlorides, sulfur-containing oxygen salts such as sulfates, nitrogen-containing oxygen salts such as nitrates, phosphorus-containing oxygen salts such as phosphates, and silicates. Examples of organic salts include carboxylates, sulfonates, and phosphonates. Furthermore, examples of transition metal complexes include complexes with β-diketones or β-keto esters. In oxygen-absorbing resins, transition metal catalysts are preferably in the range of 100 to 3000 ppm, based on the concentration of transition metal atoms (mass concentration basis).

[0042] [Adhesive layer] In the laminate of the present invention, adhesive layers can be formed between the layers as needed. In particular, when the gas barrier layer is composed of an ethylene-vinyl alcohol copolymer, the adhesion between the gas barrier layer and the polypropylene layer forming the inner and outer layers is poor, so it is preferable to include an adhesive layer. As adhesive resins used in adhesive layers, the following thermoplastic resins can be listed: thermoplastic resins containing carbonyl (-CO-) groups based on carboxylic acids, carboxylic anhydrides, carboxylate salts, carboxylic amides, carboxylic esters, etc., in the main chain or side chain at a concentration of 1 to 700 milliequivalents (meq) / 100g resin, especially 10 to 500 (meq) / 100g resin.

[0043] Preferred examples of adhesive resins include: blends of ethylene-acrylic acid copolymers, ionically crosslinked olefin copolymers, maleic anhydride-grafted polyethylene, maleic anhydride-modified polypropylene, maleic anhydride-grafted polypropylene, acrylic acid-grafted polyolefins, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, and maleic anhydride-modified olefin resins. Maleic anhydride-modified polypropylene or maleic anhydride-grafted polypropylene is particularly preferred. One or more adhesive resins can be used, or they can be incorporated into polyolefin-based resins.

[0044] [Contains adsorbent layer] In the laminate of the present invention, the adsorbent layer formed as needed is preferably located on the inner side of the oxygen absorption layer, thereby suppressing the transfer of byproducts generated by the oxygen absorption reaction into the container and improving the flavor of the contents. The adsorbent is preferably incorporated into the propylene-based polymer or recycled resin. As an adsorbent, conventionally known adsorbents can be used, with porous inorganic materials with silicates as the main component being preferred, such as zeolite, powder of activated clay obtained by acid treatment of montmorillonite and other saponite clay minerals, especially high silica zeolite (silica / alumina ratio of 100 or more) as Na-type ZSM5 zeolite, which has excellent function in capturing the odor of plastics and capturing the above-mentioned oxidation decomposition products. Such adsorbents are typically incorporated into the adsorbent-containing layer at a concentration of 0.5 to 10% by mass.

[0045] [Easy-to-peel layer] In the laminate of the present invention, for example, when the laminate of the present invention is a flanged tray or cup obtained by thermoforming multiple layers of sheets, it is preferable that the innermost layer of the laminate is an easy-peel layer (easy-opening layer). That is, in such a tray or cup, by making the upper surface of the flange portion for joining the lid material an easy-peel layer, the opening capability of the lid is significantly improved. As such an easy-to-peel layer, for example, for a cover material whose mating surface with at least the flange portion is made of an propylene polymer or an ethylene polymer, it is preferable to form an easy-to-open layer from a blend of an propylene polymer and an ethylene polymer. Examples of propylene-based polymers, besides homopolymers, include random copolymers of propylene with ethylene or other α-olefins such as 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene. Examples of ethylene-based polymers include homopolymers of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and medium / high-density polyethylene (MDPE, HDPE); or copolymers or ionomers of ethylene with other α-olefins such as 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene, as well as vinyl monomers such as (meth)acrylic acid, ethyl (meth)acrylate, methyl (meth)acrylate, vinyl acetate, and styrene.

[0046] (Manufacturing method of laminated bodies) In the method for manufacturing the laminate of the present invention, homopolymer polypropylene, which is used as a viscosity modifier, is incorporated into the ethylene-propylene block copolymer and melt-blended. Molten resin with an MFR (230°C, 2.16 kg load) viscosity adjusted to the range of 0.2 to 5 g / 10 min is then extruded, thereby forming a laminate with a surface roughness (Sa) in the range of 0.15 to 1.0 μm, particularly preferably in the range of 0.15 to 0.80 μm. As described above, by incorporating homopolymeric polypropylene in an amount of 1 to 40 parts by weight, particularly 1 to 30 parts by weight, relative to 100 parts by weight of the ethylene-propylene block copolymer, the viscosity of the resin composition can be adjusted to the aforementioned range without compromising the excellent properties of the laminate of the present invention, such as drop impact resistance, anti-blocking properties, and slip resistance. This improves moldability (workability) and allows the surface roughness (Sa) of the polypropylene layer to be adjusted to the aforementioned range. That is, if the MFR of the resin composition is lower than the aforementioned range, abnormal resin pressure may prevent film formation, resulting in the inability to obtain the desired laminate, or fluctuations may occur due to unstable flow, potentially making it impossible to adjust the surface roughness (Sa) to the aforementioned range. Furthermore, if the MFR is higher than the aforementioned range, there is a tendency for the surface smoothness to increase, making it difficult to adjust the surface roughness (Sa) to the aforementioned range.

[0047] The melt blending of ethylene-propylene block copolymers and homopolymer polypropylene can be carried out by known methods such as dry mixing of their particles using a mixer and then melt extrusion, or melt blending of their particles using a mixer. In this invention, in order to make the structural domains of the polypropylene elastomer dispersed in a spindle-shaped state of the aforementioned size, melt mixing is required, and the mixing conditions need to be appropriately adjusted according to the viscosity of the resin used. There are no particular restrictions on the temperature conditions during melt mixing, but it is preferably carried out in the range of 170 to 270°C. At temperatures lower than the above range, mixing may not be efficient, and at temperatures higher than the above range, resin deterioration may occur.

[0048] In addition to using a melt resin (blended with adjusted MFR) as described above, the laminate of the present invention can also be manufactured by conventionally known methods, and is not limited thereto. It can also be laminated with other layers by co-extrusion or co-injection molding, extrusion lamination, or by pre-forming a single-layer film or sheet from the above-mentioned blend by extrusion molding and then laminating with other layers by dry lamination, thereby forming multilayer films, multilayer sheets, multilayer tubes, etc. Furthermore, by thermoforming the multilayer sheet, it can be formed into cups, trays, etc.

[0049] In the method for manufacturing the laminate of the present invention, it is ideal that the intermediate layer constituting the laminate is a substance with a heat shrinkage rate similar to that of the resin composition (blend) constituting the polypropylene layer, used as the various resins or resin compositions constituting the intermediate layer. For example, by using the resin composition (blend) constituting the polypropylene layer as the matrix of the oxygen-absorbing resin layer, curling and shifting caused by the difference in shrinkage rates of the molded laminate can be suppressed, and the occurrence of molding defects can be suppressed. Furthermore, according to the manufacturing method of the present invention, a laminate with a polypropylene surface layer having a surface roughness (Sa) in the range of 0.15 to 1.0 μm can be formed, thus improving the sliding properties. Even when the molding process, filling / sealing process, packaging process, etc. are carried out continuously on the conveyor line, container blockage will not occur, demonstrating excellent productivity. Other layers, not limited to these, include, for example, gas barrier layers, oxygen absorption layers, recycled material layers, easy-peel layers, adhesive layers, and other known layers that have been used in polypropylene multilayer packaging materials. It should be noted that, in the case of a multilayer structure, ideally, the resin or resin composition constituting the other layers should have a thermal shrinkage rate similar to that of the ethylene-propylene block copolymer, thereby suppressing curling and shifting caused by the difference in shrinkage rates of the laminated sheets and suppressing the occurrence of molding defects. Example

[0050] The present invention will be further illustrated by experimental examples, but the present invention is not limited to these embodiments. (Experimental Examples 1-5) Using six different 7-layer multilayer sheet forming machines, the resins are melt-blended using a single-screw extruder. The mixture is then extruded from the T-die at a temperature of 230°C into sheets, which are then brought into contact with cooling rollers for curing and winding, thus forming a multilayer sheet with a thickness of 500μm. The layer structure, from the outside in, is: outermost PP layer / recycled material layer / adhesive layer / barrier layer / adhesive layer / oxygen scavenger layer / inner PP layer / easy-to-peel adhesive layer. In the outermost and inner PP layers, ethylene-propylene block copolymer particles and a white coloring resin were used. The ethylene-propylene block copolymer particles consisted of a polypropylene-based resin and a polypropylene elastomer having the compositions and molecular weights shown in Table 1. In the recycled material layer, a substance was used: 100 parts by weight of waste material from the crushing of a portion of the multilayer sheet, decorative parts, and sheet skeleton generated during this test, combined with 44 parts by weight of the ethylene-propylene block copolymer shown in Table 1, and with the addition of a compatibilizer and a white coloring resin. In the adhesive layer, maleic anhydride-modified polypropylene was used. In the oxygen scavenger layer, a resin composition was used, consisting of 29 parts by weight of an iron-based oxygen absorber (a mixture of 100 parts by weight of reduced iron powder, 2 parts by weight of sodium chloride, and 1 part by weight of calcium hydroxide) and 71 parts by weight of atactic polypropylene with an MFR of 0.6 g / 10 min. In the easy-peel adhesive layer, a resin was dry-blended from polypropylene and polyethylene. In addition, the obtained multilayer sheet is heated to 145°C and vacuum-pressed with plunger assistance to form a multilayer tray with flanges. It should be noted that the container dimensions are as follows: flange outer diameter: major axis: 155mm × minor axis: 120mm; mouth diameter: major axis: 135mm × minor axis: 100mm; bottom outer diameter: major axis: 115mm × minor axis: 90mm; height: 35mm.

[0051] (Experimental Example 6) A multi-layer tray was formed using 17.7 parts by mass of homopolymer polypropylene, which was dry-mixed with 2.0 g / 10 min MFR (230 °C, 2.16 kg load) in 100 parts by mass of resin for the outermost PP layer and the inner PP layer. Otherwise, the multi-layer tray was formed in the same manner as in Experimental Example 1.

[0052] Various determination methods are described below. Structural Analysis of Ethylene-Propylene Block Copolymers In the ethylene-propylene block copolymers used in Experimental Examples 1-5, through 13 The proportions and molecular weights of the resin (PP component) and polypropylene-based elastomer (rubber component) were determined by C-NMR (Nippon Electronics) and GPC (Agilent) measurements. As a sample pretreatment, the resin was dissolved under reflux in xylene, cooled, and then subjected to solid-liquid separation. The xylene-soluble fraction was redeprecipitated with toluene, and the precipitate was filtered, dried, and its mass was determined as the rubber component amount. The xylene-insoluble fraction was redeprecipitated with methanol, filtered, and dried to obtain the PP component. In Example 6, homopolymer polypropylene was dry-mixed, and therefore used as the calculated value.

[0053] (1) Dispersed state (domain shape and size) The cross-section cut parallel to the traction direction during sheet manufacturing at the bottom of the obtained multilayer tray was observed using a transmission electron microscope (TEM, manufactured by Hitachi). As a pretreatment, the sample cut from the multilayer tray was adhered to a low-temperature support stage and cut into a plane using a microtome (manufactured by Leica) equipped with a diamond blade via a low-temperature system (manufactured by Leica). Vapor staining with metal oxides was then performed to prepare ultrathin sections. Using image analysis software (Mac-View, manufactured by Mountech), the complete structural domains of the polypropylene elastomer in the outermost PP layer of the multilayer tray were measured based on the obtained TEM images (20μm × 20μm square). The minor and major axes of each domain were determined, and the aspect ratio and equivalent circle size of the structural domains were calculated. The average value was calculated based on the measurement results of the total number of structural domains.

[0054] (2) Surface roughness Sa (unit: μm) A 10mm × 10mm sample piece was cut from the bottom of the obtained multi-layer tray. The shape of the outer surface of the container was measured using a non-contact surface shape measuring machine (Zygo Corporation). MetroPro (Ver. 9.1.4 64-bit) was used as the application for measurement and image analysis. The measurement range was 282μm × 212μm, and wavelengths below 1.326μm were truncated from the obtained raw data for noise reduction. The average value was calculated based on N = 5.

[0055] (3) Sliding property (unit: N) Regarding the sliding properties of the multi-layer trays, a friction testing machine (Toyo Seiki) was used, with the load applied to the force sensor during measurement taken as the dynamic friction force, to determine the drag resistance value. Measurements were performed at 100 mm / min under conditions of 23°C and 50% RH, with a multi-layer tray placed on an SUS plate and a load of 600 g. The average value was calculated based on N=5. The evaluation criteria are as follows. 〇: Less than 2.5N. Δ: 2.5N or more but less than 3.0N. ×: 3.0N or more.

[0056] (4) Resistance to drop impact 200g of distilled water was added to the obtained multi-layer pallet, which was then heat-sealed with a lid and boiled at 95℃ for 30 minutes for sterilization. Afterward, it was stored at 5℃ for 24 hours. Following storage, the pallet was dropped from a height of 150cm at 5℃ to determine its drop strength. The drop strength was set to N = 20. The evaluation criteria are as follows. 〇: The number of fractures is 3 or less. Δ: Fewer than 10 fractures. ×: More than 10 cracks.

[0057] (5) Flavor Add 200g of distilled water to the resulting multi-layered tray, heat-seal with a lid, sterilize by boiling at 95℃ for 30 minutes, and then store at room temperature for 24 hours. After storage, 10 participants conducted a sensory evaluation based on a four-point method, and the average score was calculated. The evaluation criteria are as follows: 0 represents no taste, and 4 represents a level where the taste was very perceptible. 〇: Less than 2.5. Δ: 2.5 or more and less than 3.5. ×: 3.5 or more.

[0058] Based on the results, the spindle-shaped polypropylene elastomers in Examples 1 and 6 achieved a good balance between sliding properties and drop impact resistance, resulting in excellent performance. In particular, Example 6 exhibited low resin viscosity and excellent film-forming properties. Example 2 showed slightly lower drop impact resistance, likely due to the smaller amount of polypropylene elastomer. Examples 3 and 5 also showed slightly lower drop impact resistance, likely due to the shape or particle size of the polypropylene elastomer. Furthermore, the poor flavor was presumably influenced by the molecular weight of the polypropylene elastomer. Example 4 showed good drop impact resistance but poor sliding properties. This is presumably because the prismatic shape of the polypropylene elastomer, with a high aspect ratio, resulted in a smooth surface and a large contact area.

[0059] [Table 1] Industrial availability

[0060] The packaging material and the laminate with layers made of the packaging material as the surface layer of the present invention exhibit excellent impact resistance, anti-blocking properties, and flavor, and also possess excellent slip properties, thus providing excellent conveyability on the production line. Therefore, the packaging material and the laminate are preferably used for packaging materials for mass-produced food products, and are particularly preferred for containers for rice and other products where flavor is important. Furthermore, since the packaging material and the laminate are made of a propylene-based polymer with excellent heat resistance, they are also preferably used as packaging materials such as pouches that include cooking and sterilization processes.

Claims

1. A polypropylene-based packaging material, characterized in that, It is an ethylene-propylene block copolymer as follows: The ethylene-propylene block copolymer has a phase dispersion structure with polypropylene as the main component as the resin matrix and spindle-shaped polypropylene elastomers forming the structural domains. The copolymer contains 1 to 30 parts by mass of homopolymer polypropylene relative to 100 parts by mass of the ethylene-propylene block copolymer.

2. The polypropylene-based packaging material according to claim 1, wherein, The aspect ratio of the structural domain is in the range of 1.2 to 9.

0.

3. The polypropylene-based packaging material according to claim 1 or 2, wherein, The minor axis of the structural domain is in the range of 0.2 to 4.0 µm, and the major axis is in the range of 0.5 to 5.0 µm.

4. The polypropylene-based packaging material according to claim 1 or 2, wherein, The resin, which is mainly composed of polypropylene, contains 1 to 30 parts by mass of the polypropylene-based elastomer, relative to 100 parts by mass of the resin.

5. The polypropylene-based packaging material according to claim 1 or 2, wherein, The weight-average molecular weight (Mw) of the polypropylene elastomer is 500,000 to 1,000,000, and the number-average molecular weight (Mn) is 10,000 to 300,000.

6. The polypropylene-based packaging material according to claim 1 or 2, wherein, The resin with polypropylene as its main component has a weight-average molecular weight (Mw) of 300,000 to 800,000 and a number-average molecular weight (Mn) of 10,000 to 300,000.

7. The polypropylene-based packaging material according to claim 1 or 2, wherein, The surface roughness Sa is 0.15–1.0 µm.

8. The polypropylene-based packaging material according to claim 1 or 2, wherein, It can take any of the following forms: sheet, film, tray, or cup.

9. A polypropylene-based packaging material, characterized in that, It is an ethylene-propylene block copolymer as follows: The ethylene-propylene block copolymer has a phase dispersion structure with polypropylene as the main component as the resin matrix and spindle-shaped polypropylene elastomers forming the structural domains. The resin, which is mainly composed of polypropylene, contains 1 to 30 parts by mass of the polypropylene-based elastomer, relative to 100 parts by mass of the elastomer. The aspect ratio of the structural domain is in the range of 1.2 to 8.0, and the minor axis of the structural domain is in the range of 0.2 to 4.0 μm and the major axis is in the range of 0.5 to 5.0 μm. The weight-average molecular weight (Mw) of the polypropylene elastomer is 500,000 to 1,000,000, and the number-average molecular weight (Mn) is 10,000 to 300,000.

10. The polypropylene-based packaging material according to claim 9, wherein, The resin with polypropylene as its main component has a weight-average molecular weight (Mw) of 300,000 to 800,000 and a number-average molecular weight (Mn) of 10,000 to 300,000.

11. The polypropylene-based packaging material according to claim 9 or 10, wherein, The copolymer contains 1 to 40 parts by mass of homopolymer polypropylene relative to 100 parts by mass of the ethylene-propylene block copolymer.

12. The polypropylene packaging material according to claim 9 or 10, wherein it is any one of sheet, film, tray, or cup.

13. A laminated body, characterized in that, The laminate having a polypropylene layer as a surface layer is composed of an ethylene-propylene block copolymer, which is a polypropylene-based packaging material as described in any one of claims 1-6 and 9-11. The surface roughness Sa of the polypropylene layer is 0.15 to 1.0 µm.

14. The laminate according to claim 13, wherein, It shall have at least the following features: the polypropylene layer as the inner layer and the outer layer, and an oxygen-absorbing layer and a gas-barrier layer as the intermediate layer.

15. The laminate according to claim 13 or 14, wherein, It has the shape of a tray or cup.

16. A method for manufacturing a laminated body, characterized in that, A method for manufacturing a laminate having a polypropylene layer as a surface layer, wherein the polypropylene layer is composed of an ethylene-propylene block copolymer, the ethylene-propylene block copolymer having a phase dispersion structure in which a polypropylene-based elastomer with a spindle shape forms the structural domains, wherein... By incorporating homopolymer polypropylene as a viscosity modifier into the ethylene-propylene block copolymer and performing melt mixing, the MFR viscosity at 230°C and 2.16 kg load is adjusted to the range of 0.1 to 10 g / 10 minutes. The molten resin with the adjusted viscosity is then extruded, thereby forming a surface layer with a surface roughness of 0.15 µm to 1.0 µm.

17. The method for manufacturing a laminate according to claim 16, wherein, 1 to 30 parts by weight of the homopolymer are added relative to 100 parts by weight of the ethylene-propylene block copolymer.

18. The method for manufacturing a laminate according to claim 16 or 17, wherein, The polypropylene elastomer contains 1 to 30 parts by weight of the polypropylene-based elastomer relative to 100 parts by weight of the ethylene-propylene block copolymer.

19. The method for manufacturing a laminate according to claim 16 or 17, wherein, The weight-average molecular weight (Mw) of the polypropylene elastomer is 500,000 to 1,000,000, and the number-average molecular weight (Mn) is 10,000 to 300,000.

20. The method for manufacturing a laminate according to claim 16 or 17, wherein, The resin with polypropylene as its main component has a weight-average molecular weight (Mw) of 300,000 to 800,000 and a number-average molecular weight (Mn) of 10,000 to 300,000.

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