Resin composition, resin layer, laminate and container

Abstract

To provide a resin composition which reduces a content of a resin component by adding inorganic particles, and satisfies the requirement for physical durability (impact resistance) of a container using the resin component, a resin layer, a laminate and a container.SOLUTION: There are provided a resin composition which contains two or more kinds of inorganic particles, and one or more kinds of resin components, wherein the content of the total of the inorganic particles is 10.0 mass% or more and 80.0 mass% or less, and the content of the total of the resin components is 20.0 mass% or more and 70.0 mass% or less; a resin layer using the resin composition; a laminate; and a container.SELECTED DRAWING: Figure 1

Description

[Background technology]

[0001] Resin molded containers are used as containers for a variety of liquid or solid products, including food packaging, beverages, cooking oils, precision instruments, stationery, industrial products such as screws and nuts, detergents, shampoos, and seasonings (for example, Patent Document 1). This is because resins can be easily molded into required shapes and have the properties of high chemical and physical durability.

[0002] Furthermore, in order to achieve sufficient rigidity and strength required for food containers, studies have been conducted to use a specific resin composition for the heat insulating base layer in the laminated sheet (Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 08-244747 [Patent Document 2] Patent Publication No. 2021-37748 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide a resin composition, a resin layer, a laminate, and a container that have excellent dispersibility while reducing the content of resin components by adding inorganic particles, and that allow containers and the like using the same to satisfy physical requirements (moldability, impact resistance, heat resistance) and suppress elution therefrom. [Means for solving the problem]

[0005] As a result of extensive research into solving the above problems, the present inventors provide the following [1] to [6]. [1] A resin composition comprising two or more types of inorganic particles and one or more types of resin components, wherein the total content of the inorganic particles is 10.0% by mass or more and 80.0% by mass or less, and the total content of the resin components is 20.0% by mass or more and 70.0% by mass or less. [2] A resin layer using the resin composition according to [1]. [3] A laminate comprising the resin layer according to [2] and one or two surface layers. [4] A container comprising the resin layer according to [2]. [5] A container comprising the laminate described in [3]. [6] An article containing the container and contents described in [4] or [5]. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a resin composition, a resin layer, a laminate, and a container that have excellent dispersibility while reducing the content of resin components by adding inorganic particles, and that allow containers and the like using the same to satisfy physical requirements (moldability, impact resistance, heat resistance) and suppress elution therefrom. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram of a laminate of the present embodiment including one surface layer 120. FIG. [Figure 2] FIG. 1 is a conceptual diagram of a method for producing a resin composition, a resin layer, a laminate, a container, and an article according to the present embodiment (an example in which a masterbatch is not used). [Figure 3] 1 is a conceptual diagram relating to a method for producing a resin composition, a resin layer, a laminate, a container, and an article according to an embodiment of the present invention (an example using a masterbatch). [Figure 4] 1 is a schematic diagram of a laminate of the present embodiment including a surface layer 121 and a surface layer 122. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] The above-mentioned Patent Document 1 describes an invention relating to a resin bottle having a specific layer structure. However, although the invention describes imparting shape retention to this resin bottle, it does not consider improving impact resistance or elution from the resin bottle.

[0009] Although Patent Document 2 describes a laminated sheet containing only talc in an amount of about 20% as an inorganic filler, it does not examine the effects of using two or more types of inorganic particles.

[0010] Currently, resin compositions used in containers and the like are required to improve physical requirements (moldability, impact resistance, heat resistance, etc.) while being environmentally friendly. Environmentally friendly resin compositions are required to increase the content of inorganic particles in order to reduce the content of resin components in the resin composition. Increasing the content of inorganic particles can improve the heat resistance of a resin layer using a resin composition, but due to low compatibility with the resin component, there is a limit to the upper limit of the content. It is also known that increasing the content of inorganic particles reduces the moldability and impact resistance, as well as the moldability when molding the resin layer into a container. In addition, increasing the content of inorganic particles in the container material also poses the problem of leaching of components derived from the inorganic particles into the contents.

[0011] Recently, there has been a strong demand for the resin component content to be 50.0% by mass or less in the resin composition. However, if only one type of inorganic particle is used to achieve this, it is difficult to uniformly disperse the inorganic particle in the resin. Even if this is achieved, the impact resistance and moldability are significantly reduced. Poor impact resistance can lead to damage to the container during transportation or storage, and if the contents are liquid, there is a risk of leakage. Furthermore, when the contents are precision machinery such as a central processing unit (CPU), impact resistance is required to protect the CPU from external impact, but there have been problems such as the inability to meet these requirements. Furthermore, leaching from the container can have adverse effects on the human body in the case of food containers, and can cause a decrease in yield due to short circuits in the case of precision machinery.

[0012] In the present disclosure, "impact resistance" refers to the ability of a container or the like to not or is suppressed from breaking when dropped. In the present disclosure, "heat resistance" refers to the ability to retain the shape of a container at high temperatures after it has been made into a container; for example, in the case of a food container, this refers to the property of the container's shape changing little even when heated to high temperatures in a microwave oven or the like.

[0013] In the present disclosure, "moldability" means that the temperature and pressure range when using the resin composition to manufacture a container or the like is wide and within a range that can be achieved with ordinary manufacturing equipment, and that the physical properties of the resin composition do not change at those temperatures and pressures, the fluidity of the resin composition is suitable for injection molding or the like, and the shrinkage rate is small. For the resin composition of this embodiment, it is important that the temperature and pressure during molding are within an appropriate range, and that the shrinkage rate after manufacturing the laminate or container is small.

[0014] When conventional resin compositions were used, the decrease in impact resistance was particularly noticeable at extremely low temperatures, such as -20°C or below. When used as a tray for frozen foods, the contents must be protected in the freezer, and when used as a container for transporting precision equipment, impact resistance is required at the extremely low temperatures of the cargo hold during transport as air cargo. For these reasons, there has been a demand for a resin composition that satisfies the requirements for physical impact resistance while reducing the content of resin components.

[0015] The resin composition of the present disclosure uses two or more types of inorganic particles in combination, thereby increasing the content thereof and reducing the content of the resin component in the resin composition, and it is possible to provide a resin composition that has excellent dispersibility and satisfies the physical requirements (moldability, impact resistance, heat resistance) of containers and the like that use the resin composition.

[0016] In addition, resin layers and laminates using the resin composition of the present disclosure have excellent moldability and suppress elution therefrom, making them excellent materials for containers.

[0017] The resin composition according to the present disclosure, and a resin layer, a laminate, a container, and an article using the same will be described below, but the present invention is not limited to the following examples.

[0018] In the present disclosure, the thickness direction 1 refers to the thickness direction of the resin layer (laminate) as shown in Fig. 1, and the width direction 2 refers to a direction different from the thickness direction and perpendicular to the longitudinal direction 3 of the resin layer (laminate). For example, when the resin layer (laminate) is manufactured by melt extrusion molding, the longitudinal direction 3 corresponds to the machine direction (MD), and the width direction 2 corresponds to the transverse direction (TD) perpendicular to the MD.

[0019] Hereinafter, an embodiment of the present disclosure (hereinafter, sometimes referred to as "the present embodiment") will be described. Note that in this disclosure, numerical values ​​related to "greater than or equal to," "less than or equal to," "to," etc., in describing a numerical range can be arbitrarily combined.

[0020] Furthermore, preferred provisions can be adopted arbitrarily. That is, one preferred provision can be adopted in combination with one or more other preferred provisions. A combination of preferred provisions can be considered more preferable.

[0021] [Resin composition] The resin composition of this embodiment is required to be a resin composition containing two or more types of inorganic particles and one or more types of resin components, in which the total content of the inorganic particles is 10.0 mass% or more and 80.0 mass% or less, and the total content of the resin components is 20.0 mass% or more and 70.0 mass% or less.

[0022] The inorganic particles are hardly soluble in the resin component and may be partially dissolved, but the resin composition is in a state in which the inorganic particles are dispersed in the resin composition.

[0023] The resin composition of this embodiment may be used to form a resin layer, which will be described later, as shown in Fig. 2, or may be used as a so-called masterbatch. When used as a masterbatch, a resin component and the like may be further added and the resulting resin composition may be used as a resin composition for forming a resin layer, as shown in Fig. 3. Hereinafter, unless otherwise specified, the resin composition refers to a resin composition used to form a resin layer, and a masterbatch is referred to as a masterbatch.

[0024] The masterbatch refers to a product in process that is diluted 2 to 10 times with a resin component to form a resin composition for forming a resin layer. The use of a masterbatch is preferred because the content of inorganic particles in the resin composition can be easily adjusted by dilution.

[0025] In the present disclosure, for example, "diluting two-fold" means that 1 part by mass of the resin component is added to 1 part by mass of the masterbatch, and stirred as necessary to form a resin composition.

[0026] The resin composition of the present embodiment is preferably used as a container for contents because the resin layer using the composition has excellent impact resistance. Examples of contents that can be used include liquid or solid foods such as food, beverages, cooking oils, and seasonings, as well as precision instruments, stationery, industrial products such as screws and nuts, and daily consumables such as detergents and shampoos. Because the resin composition has excellent impact resistance, particularly at low temperatures, it is suitable for use as a container for frozen foods and other foods to be used at low temperatures.

[0027] In addition, its excellent moldability makes it suitable for use as a container for precision instruments and other devices that require dimensional stability. Furthermore, its excellent impact resistance even at high temperatures means it can withstand heating in a microwave oven, etc., making it an excellent container for use over a wide temperature range.

[0028] Furthermore, the resin composition of the present embodiment is preferable because it has long-term storage stability since inorganic particles are less likely to precipitate from the resin composition, and it is easy to produce, resulting in excellent productivity.

[0029] Furthermore, the resin layer of the present embodiment is preferable because it suppresses elution originating from inorganic particles, thereby suppressing the influence on the contents.

[0030] The resin composition of the present embodiment may contain the resin component and inorganic particles in the above-mentioned amounts, but may further contain additives that are typically contained in resin compositions in the field, with the additives described below being preferred.

[0031] The inorganic particles, resin components and additives will be described below, but are not limited to the following examples.

[0032] <Inorganic particles> The inorganic particles used in this embodiment are particles classified as inorganic substances, and their particle size distribution (D 50 ) is preferably 1 μm or more and 100 μm or less. 50 means a value determined by laser analysis / scattering method, and can be measured, for example, by the method described in the Examples. The shape is preferably powder, spheres, flakes, granules, or fibers.

[0033] Examples of the inorganic particles include the following: carbonates, sulfates, silicates, phosphates, or borates of metals (calcium, magnesium, aluminum, titanium, iron, zinc, etc.); oxides of metals (calcium, magnesium, aluminum, titanium, iron, zinc, etc.); hydrates of the above salts or oxides, and the like, which may be synthesized or derived from natural minerals.

[0034] Of these, particularly preferred are calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, clay, talc, kaolin, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, calcium silicate, aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica, carbon black, zeolite, molybdenum, diatomaceous earth, and bentonite.

[0035] Talc is classified as a clay mineral and is a silicate mineral (Mg3Si4O 10 It is a type of phyllosilicate (OH)2). It is a mineral composed of magnesium hydroxide and silicate, and includes rocks that are primarily composed of this mineral. It is also known as talc, steatite, soapstone, French chalk, and lava.

[0036] The inorganic component is preferably a mixture of salt particles such as metal carbonates, sulfates, silicates, phosphates, or borates, and neutral particles such as metal oxides, silica, carbon black, zeolites, diatomaceous earth, and natural products such as bentonite. If salt particles alone are used, the container using them will have basic properties, so it is preferable to use them in combination with neutral particles. In particular, if the contents are susceptible to basicity, such as food, they will be subject to deterioration, so it is more preferable to use basic particles in combination with neutral particles. This combination is preferable because it increases the content of inorganic particles while suppressing basicity, thereby reducing the content of the resin composition in the resin composition.

[0037] Combinations including talc and calcium carbonate, talc and magnesium carbonate, talc and titanium oxide, talc and carbon black, talc and silica, talc and diatomaceous earth, talc and bentonite, calcium carbonate and carbon black, calcium carbonate and silica, calcium carbonate and diatomaceous earth, and calcium carbonate and bentonite are preferred, with talc and calcium carbonate, talc and magnesium carbonate, talc and silica, calcium carbonate and carbon black, calcium carbonate and silica, calcium carbonate and diatomaceous earth, and calcium carbonate and bentonite being more preferred, with talc and calcium carbonate being even more preferred, and talc and calcium carbonate being even more preferred. The inorganic particles may be surface-modified or coated to improve dispersibility. The coating may be an organic coating such as silicone, or an inorganic coating such as silica gel or alumina.

[0038] As described above, it is preferable to contain talc and calcium carbonate. However, increasing the calcium carbonate content increases the basicity of the resin composition. This can lead to leaching from the inorganic particles and denaturing the contents. In contrast, using talc in combination is preferable because it increases the inorganic particle content while suppressing the basic effects of calcium carbonate. Furthermore, it has been found that it also improves impact resistance compared to using calcium carbonate alone. On the other hand, attempting to increase the inorganic particle content using talc alone is difficult due to the low dispersibility of talc in the resin composition. Therefore, combining talc and calcium carbonate is preferable because it increases the inorganic particle content in the resin composition and improves impact resistance. Furthermore, the improved dispersibility of the inorganic particles in the resin composition reduces the effects of inorganic particle precipitation during resin layer production, making it preferable from the standpoint of manufacturability. Additionally, when used as a container for frozen foods, for example, it is preferable because it can be used over a wide temperature range, from low temperatures during storage to high temperatures during cooking using a microwave oven, etc.

[0039] The total content of the inorganic particles in the resin composition of this embodiment must be 10.0% by mass or more and 80.0% by mass or less.

[0040] The lower limit of the total content of the inorganic particles is more preferably 30.0% by mass or more, even more preferably 35.0% by mass or more, even more preferably 40.0% by mass or more, and excellently preferred is 42.0% by mass or more, more excellently preferred is 45.0% by mass or more, and even more excellently preferred is 48.0% by mass or more. The upper limit is more preferably 68.0% by mass or less, even more preferably 65.0% by mass or less, even more preferably 62.0% by mass or less, and excellently preferred is 60.0% by mass or less, in order to increase the total content of the inorganic particles, thereby producing an environmentally friendly product with a reduced amount of resin used, and to improve heat resistance.

[0041] In the present disclosure, the "long-term storage stability" is determined by visually observing the precipitation of solid matter (inorganic particles) from the resin composition when the resin composition is left to stand at 25°C for 30 days, and if no solid matter is observed, the resin composition is determined to have excellent long-term storage stability.

[0042] When used as the masterbatch, the upper limit of the total content of the inorganic particles is preferably 90.0 mass% or less, more preferably 86.0 mass% or less, even more preferably 84.0 mass% or less, and even more preferably 82.0 mass% or less, and the lower limit is preferably 70.0 mass% or more, more preferably 73.0 mass% or more, even more preferably 75.0 mass% or more, and even more preferably 78.0 mass% or more.

[0043] When calcium carbonate is used as the inorganic particles, its D 50 is preferably 1.0 μm or more and 15.0 μm or less, more preferably 2.0 μm or more and 10.0 μm or less, and even more preferably 3.0 μm or more and 8.0 μm or less.

[0044] When talc is used as the inorganic particles, its D 50 is preferably 3.0 μm or more and 20.0 μm or less, more preferably 4.0 μm or more and 18.0 μm or less, and even more preferably 5.0 μm or more and 16.0 μm or less.

[0045] The content of calcium carbonate relative to the total amount of the inorganic particles is preferably 3.0 mass% or more and 50.0 mass% or less, more preferably 5.0 mass% or more and 40.0 mass% or less, even more preferably 6.0 mass% or more and 30.0 mass% or less, and even more preferably 8.0 mass% or more and 25.0 mass% or less.

[0046] The talc content relative to the total amount of the inorganic particles is preferably 40.0% by mass or more and 95.0% by mass or less, preferably 60.0% by mass or more and 93.0% by mass or less, preferably 70.0% by mass or more and 92.0% by mass or less, and preferably 75.0% by mass or more and 90.0% by mass or less.

[0047] When talc and calcium carbonate are used in combination as the inorganic particles, the value obtained by dividing the content of the talc contained in the inorganic particles by the content of the calcium carbonate (the talc content (g by mass) / the calcium carbonate content (g by mass)) is preferably 1.0 to 10.0, more preferably 2.0 to 9.3, even more preferably 3.0 to 8.8, and even more preferably 3.8 to 8.5. The total content of the talc and calcium carbonate relative to the total amount of the inorganic particles is preferably 95.0% by mass or more, more preferably 98.0% by mass or more, and even more preferably 99.0% by mass or more. Although there is no particular upper limit, it is preferable that the inorganic particles essentially consist of the talc and calcium carbonate. In the present disclosure, "substantially" means excluding unintentionally contained impurities.

[0048] <Resin component> The resin component preferably contains a thermoplastic resin or a thermosetting resin, and in order to facilitate the production of the container described below, it preferably contains one or more types of thermoplastic resins. The total content of the resin components in the resin composition of this embodiment must be 20.0% by mass or more and 70.0% by mass or less.

[0049] The lower limit of the total content of the resin components is more preferably 22.0% by mass or more, even more preferably 25.0% by mass or more, even more preferably 28.0% by mass or more, even more preferably 30.0% by mass or more, and even more preferably 35.0% by mass or more in order to improve impact resistance, moldability, and long-term storage stability. The upper limit is more preferably 68.0% by mass or less, even more preferably 65.0% by mass or less, even more preferably 62.0% by mass or less, and even more preferably 60.0% by mass or less in order to increase the total content of the inorganic particles, produce an environmentally friendly product with a reduced amount of resin used, and improve heat resistance.

[0050] When used as the masterbatch, the upper limit of the total content of the resin components in the resin composition of the present embodiment is preferably 30.0 mass% or less, more preferably 28.0 mass% or less, even more preferably 25.0 mass% or less, and even more preferably 24.0 mass% or less, and the lower limit is preferably 20.0 mass% or more, more preferably 21.0 mass% or more, even more preferably 22.0 mass% or more, and even more preferably 23.0 mass% or more.

[0051] The value obtained by dividing the total content of the resin components by the total content of the inorganic particles (total content of the resin components (mass g) / total content of the inorganic particles (mass g)) is preferably 0.4 or more and 2.0 or less, more preferably 0.6 or more and 1.6 or less, even more preferably 0.7 or more and 1.4 or less, and even more preferably 0.8 or more and 1.2 or less, in order to improve the balance between at least two of impact resistance, moldability, heat resistance, elution of components derived from the inorganic particles, and long-term storage stability.

[0052] <<Thermoplastic resin>> The total content of the thermoplastic resin in the resin composition of this embodiment is preferably 20.0% by mass or more and 70.0% by mass or less. The lower limit of the total content of the thermoplastic resin is more preferably 22.0% by mass or more, even more preferably 25.0% by mass or more, even more preferably 28.0% by mass or more, more preferably 30.0% by mass or more, and even more preferably 35.0% by mass or more in order to improve impact resistance, moldability, and long-term storage stability. The upper limit is more preferably 68.0% by mass or less, even more preferably 65.0% by mass or less, even more preferably 62.0% by mass or less, and even more preferably 60.0% by mass or less in order to increase the total content of the inorganic particles, produce an environmentally friendly product with a reduced amount of resin used, and improve heat resistance. The upper limit is more preferably 68.0% by mass or less, even more preferably 65.0% by mass or less, even more preferably 62.0% by mass or less, and even more preferably 60.0% by mass or less, and even more preferably 60.0% by mass or less.

[0053] When used as the masterbatch, the upper limit of the total content of the thermoplastic resins in the resin composition of the present embodiment is preferably 30.0 mass% or less, more preferably 28.0 mass% or less, even more preferably 25.0 mass% or less, and even more preferably 24.0 mass% or less, and the lower limit is preferably 20.0 mass% or more, more preferably 21.0 mass% or more, even more preferably 22.0 mass% or more, and even more preferably 23.0 mass% or more.

[0054] Examples of the thermoplastic resin include polyolefin resins, polyester resins, and polystyrene resins, with polyolefin resins being preferred due to their good moldability. In order to improve impact resistance, the mass average molecular weight (Mw) of the polyolefin resin is preferably 30,000 or more and 500,000 or less, more preferably 50,000 or more and 300,000 or less, even more preferably 70,000 or more and 200,000 or less, and even more preferably 90,000 or more and 100,000 or less.

[0055] In order to improve impact resistance, the polydispersity (Mw / Mn) of the polyolefin resin is preferably 1.5 or more and 5.0 or less, more preferably 1.6 or more and 4.0 or less, even more preferably 1.7 or more and 3.0 or less, and even more preferably 1.9 or more and 2.2 or less.

[0056] In order to improve impact resistance, the glass transition point (Tg) of the polyolefin resin is preferably 100°C or higher, more preferably 108°C or higher, even more preferably 115°C or higher, and even more preferably 117°C or higher.

[0057] The upper limit of Tg is not particularly limited, but from the viewpoint of formability, it is preferably 150°C or less, more preferably 140°C or less, even more preferably 130°C or less, and even more preferably 125°C or less.

[0058] In order to achieve the above Tg range, it is preferable to add a metallocene polyolefin resin to the polyolefin resin.

[0059] When a polyolefin-based resin is used as the thermoplastic resin, the total content of the polyolefin-based resin with respect to the total content of the resin composition is preferably 20.0% by mass or more and 70.0% by mass or less. The lower limit of the total content of the thermoplastic resin is more preferably 22.0% by mass or more, even more preferably 25.0% by mass or more, even more preferably 28.0% by mass or more, even more preferably 30.0% by mass or more, and even more preferably 35.0% by mass or more, in order to improve impact resistance, moldability, and long-term storage stability. The upper limit is more preferably 68.0% by mass or less, even more preferably 65.0% by mass or less, even more preferably 62.0% by mass or less, even more preferably 60.0% by mass or less, and even more preferably 60.0% by mass or less, in order to increase the total content of the inorganic particles, produce an environmentally friendly product with reduced resin usage, and improve heat resistance.

[0060] When used as the masterbatch, the upper limit of the total content of the polyolefin resin in the resin composition of the present embodiment is preferably 30.0 mass% or less, more preferably 28.0 mass% or less, even more preferably 25.0 mass% or less, and even more preferably 24.0 mass% or less, and the lower limit is preferably 20.0 mass% or more, more preferably 21.0 mass% or more, even more preferably 22.0 mass% or more, and even more preferably 23.0 mass% or more.

[0061] The polyolefin resin is preferably a polyolefin resin containing, as the main component, a component unit derived from an olefin, and the component unit derived from an olefin is preferably contained in the polyolefin resin at 60.0 mass % or more, more preferably 70.0 mass % or more, even more preferably 80.0 mass % or more, even more preferably 90.0 mass % or more, and most preferably 95.0 mass % or more.

[0062] The polyolefin resin of the present disclosure may be one obtained by a general production method, but methods using a metallocene catalyst, a Ziegler-Natta catalyst, a radical initiator, or the like are preferred. However, when impact resistance at low temperatures is required, a metallocene polyolefin resin produced using a metallocene catalyst is preferred, as metallocene polyolefin resins have a narrow molecular weight distribution and high copolymerizability. Examples of polyolefin resins include polypropylene resins (hereinafter referred to as PP resins) and polyethylene resins (hereinafter referred to as PE resins).

[0063] It is also preferable to use a metallocene-based polyolefin resin in combination with a polyethylene-based resin produced without using a metallocene-based catalyst, and a combination of a metallocene-based PP resin and a PP resin, a combination of a metallocene-based PE resin and a PE resin, and further combinations thereof are also preferred.

[0064] (Polypropylene resin (PP resin)) The polypropylene-based resin (PP resin) in this embodiment may be a polypropylene homopolymer, or may be a copolymer of propylene and another α-olefin. The polypropylene homopolymer may be an isotactic type in which the chirality of carbon atoms to which methyl groups are attached faces the same direction relative to the polymer main chain, a syndiotactic type in which the carbon atoms are arranged alternately, an atactic type in which the carbon atoms are arranged randomly, or a hemiisotactic type which is a combination of these.

[0065] The copolymer preferably contains 60.0% by mass or more of component units derived from propylene in the PP resin, more preferably 70.0% by mass or more, even more preferably 80.0% by mass or more, and even more preferably 85.0% by mass or more.

[0066] The copolymer may be any of a polypropylene random copolymer (random copolymer), a polypropylene block copolymer (block copolymer), a binary copolymer, a ternary copolymer, etc., and preferred examples include an ethylene-propylene random copolymer, a butene-1-propylene random copolymer, an ethylene-butene-1-propylene random terpolymer, and an ethylene-propylene block copolymer.

[0067] Preferred examples of the α-olefin include α-olefins having 4 to 10 carbon atoms (such as ethylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, and 3-methyl-1-hexene).

[0068] (Polyethylene resin (PE resin)) The polyethylene resin (PE resin) in the present disclosure may be a polyethylene homopolymer, or may be a copolymer of ethylene and another α-olefin.

[0069] The copolymer preferably contains ethylene-derived component units in an amount of 70.0% by mass or more, more preferably 80.0% by mass or more, even more preferably 90.0% by mass or more, and even more preferably 95.0% by mass or more, in the PE resin.

[0070] Preferred examples of polyethylene resins include low-density polyethylene (LDPE), high-density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMW-PE), ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-propylene-butene 1 copolymer, ethylene-buten-1-yl copolymer, ethylene-hexen-1-yl copolymer, ethylene-4-methylpentene 1 copolymer, and ethylene-octen-1-yl copolymer.

[0071] <Additives> If necessary, the resin composition may further contain additives, such as foaming agents, colorants, lubricants, antistatic agents, antioxidants, ultraviolet absorbers, and light stabilizers that are commonly used in the art.

[0072] For example, as the ultraviolet absorber, a benzotriazole-based compound is preferred. Since these additives improve impact resistance and moldability, the total content of the additives relative to the total content of the resin composition is preferably 10.0 mass% or less, more preferably 8.0 mass% or less, even more preferably 5.0 mass% or less, even more preferably 3.0 mass% or less, and even more preferably 1.0 mass% or less. There is no particular restriction on the lower limit value as long as the resin composition of the present embodiment exhibits the effects of the invention.

[0073] [Resin layer] The resin layer of the present embodiment is required to be a resin layer using the above-mentioned resin composition. In this embodiment, the thickness of the resin layer is preferably 50 μm or more, more preferably 100 μm or more, even more preferably 150 μm or more, and even more preferably 200 μm or more in order to improve impact resistance, and is preferably 2000 μm or less, more preferably 1800 μm or less, even more preferably 1500 μm or less, even more preferably 1200 μm or less, and even more preferably 1000 μm or less in order to improve moldability.

[0074] [Laminate] The laminate of this embodiment must include the resin layer and one or two surface layers. The laminate of this embodiment preferably includes the resin layer and further includes a surface layer on one or both sides of the resin layer. The surface layer may be formed directly on the resin layer, or, if necessary, the surface layer may be laminated via a primer layer or an adhesive layer as another layer.

[0075] In particular, when a basic compound such as calcium carbonate is used as the inorganic particles and the contents are affected by the basicity, providing a surface layer on the content side of the resin layer is preferable because the effect of the basic compound on the contents can be suppressed.Providing a surface layer on the content side of the resin layer is preferable because the content of the basic compound such as calcium carbonate in the resin composition can be increased.

[0076] The layer thickness of the laminate is determined by the configuration of the resin layer, surface layer, and other layers, and the layer thickness of each layer, but in order to improve moldability and impact resistance, it is preferably 50 μm or more and 2000 μm or less, more preferably 100 μm or more and 1800 μm or less, even more preferably 150 μm or more and 1500 μm or less, even more preferably 180 μm or more and 1200 μm or less, and even more preferably 200 μm or more and 1000 μm or less.

[0077] <<Surface layer>> In order to suppress the influence of the base of the contents and to improve moldability, the thickness of the surface layer is preferably 1 μm or more and 500 μm or less, more preferably 2 μm or more and 300 μm or less, even more preferably 5 μm or more and 200 μm or less, even more preferably 0 μm or more and 100 μm or less, and even more preferably 10 μm or more and 80 μm or less. The surface layer is preferably the thermoplastic resin layer, and more preferably the PP resin layer.

[0078] 〔container〕 The container of this embodiment must include the resin layer or the laminate. The container has excellent impact resistance, heat resistance, and chemical stability, making it an excellent container for protecting the contents described below during transportation. Furthermore, because of its excellent moldability, it can be manufactured inexpensively, and since it can be molded to fit the shape of a precision instrument when transporting it, it is an excellent container because it can prevent the precision instrument from moving and being damaged during transportation. The container shape may be appropriately determined based on the shape of the contents, etc.

[0079] [Goods] The article of this embodiment must include the container and the contents described below. <<Contents>> The contents may be liquid, liquid crystal, or solid, such as food, beverages, cooking oil, seasonings, precision instruments such as CPUs and memory, stationery, industrial products such as screws or nuts, machine tools such as pliers or hammers, and daily consumables such as detergents or shampoos.

[0080] [Methods for producing resin composition, resin layer, and laminate] Examples of the methods for producing the resin composition, resin layer, laminate, and container of this embodiment will be described below, but the present invention is not limited thereto. The resin composition of this embodiment can be produced, for example, by the following production method. Two or more types of inorganic particles, one or more types of resin components, and additives as required are melt-mixed in appropriate amounts, and cooled to form a masterbatch.

[0081] A laminate can be produced using a two-kind, three-layer co-extruder. More specifically, as the resin composition for forming the resin layer 110 shown in FIG. 4, an appropriate blending amount of the masterbatch, one or more resin components, and additives as necessary are melt-mixed and fed into a single extruder. The raw materials for forming the surface layers 121 and 122 on both sides are also fed into the extruder and fed to a two-kind, three-layer feedblock T-die at a predetermined temperature. A three-layer sheet is extruded through a die adjusted to an appropriate lip clearance, rolled with three polishing rolls, and cooled to room temperature. A three-layer sheet including the resin layer 110 with the surface layers 121 and 122 laminated on both sides is formed, and then wound into a roll, thereby producing the laminate.

[0082] When forming a laminate without using a masterbatch, a resin composition for forming a resin layer can be used in an extruder with appropriate amounts of two or more types of inorganic particles, one or more resin components, and additives as needed. Although the above-mentioned manufacturing method has been described as an example having two surface layers, by not forming unnecessary surface layers, it is possible to manufacture a laminate having the desired resin layer or a surface layer on only one side.

[0083] Although the method of co-extrusion has been described as a method for producing a laminate, a T-die method, an inflation method, a calendar method, etc. may also be used.

[0084] [Container manufacturing method] The laminate (resin composition) exemplified above can be molded into a desired shape by a method commonly used in the art, such as vacuum molding, pressure molding, matched mold molding, etc. The resin composition, resin layer, laminate, container and article of the present embodiment preferably satisfy the following items [1] to

[16] .

[0085] [1] Two or more types of inorganic particles; One or more resin components, The total content of the inorganic particles is 10% by mass or more and 80% by mass or less, A resin composition in which the total content of the resin components is 20% by mass or more and 70% by mass or less. [2] The resin composition according to [1], wherein the value obtained by dividing the total content of the resin components by the total content of the inorganic particles (total content of the resin components (mass g) / total content of the inorganic particles (mass g)) is 0.4 or more and 2.0 or less. [3] The resin composition according to [1] or [2], wherein the inorganic particles include calcium carbonate and talc. [4] The particle size distribution (D 50 ) is 1.0 μm or more and 15.0 μm or less. [5] The particle size distribution of the talc (D 50The resin composition according to [3] or [4], wherein the particle size is 3.0 μm or more and 20.0 μm or less. [6] The resin composition according to any one of [3] to [5], wherein the content of the calcium carbonate relative to the total amount of the inorganic particles is 3% by mass or more and 50% by mass or less. [7] The resin composition according to any one of [3] to [6], wherein the content of the talc relative to the total amount of the inorganic particles is 40% by mass or more and 95% by mass or less. [8] The resin composition according to any one of [3] to [7], wherein the value obtained by dividing the content of the talc contained in the inorganic particles by the content of the calcium carbonate (the content of the talc (mass g) / the content of the calcium carbonate (mass g)) is 1.0 or more and 10.0 or less. [9] The resin composition according to any one of [1] to [8], which contains one or more thermoplastic resins as the resin component.

[10] The resin composition according to [9], wherein the thermoplastic resin contains a polyolefin resin.

[11] The resin composition according to any one of [1] to

[10] , further comprising an additive.

[12] A resin layer using the resin composition according to any one of [1] to

[11] .

[13] A laminate comprising the resin layer according to

[12] and one or two surface layers.

[14] A container comprising the resin layer according to

[12] .

[15] A container comprising the laminate according to

[13] .

[16] An article comprising a container as described in

[14] or

[15] and its contents. [Example]

[0086] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples.

[0087] (Evaluation method) 1.Dispersibility The state of melt mixing in the single extruder described below was visually observed and rated on the following three levels, with A and B being considered acceptable. A rating (marked as A in the table): Uniformly dispersed. B rating (marked as B in the table): Solids that were not dispersed in the resin were observed, but the moldability rating below was A or B, and there were no practical problems. C rating (marked as C in the table): Unable to dissolve and mix or the moldability rating below is C.

[0088] 2.Moldability The containers formed from the laminate were visually inspected and rated on the following three levels, with ratings of A and B being considered acceptable. A rating (marked as A in the table): No defects (holes, uneven thickness or burrs) were found on the container. B rating (marked as B in the table): Test containers were found to have whitening only around the convex parts of the mold used during molding, but there are no problems with the manufacturing process. C rating (marked as C in the table): Defects were found on the entire bottom of the container.

[0089] 3. Shock resistance The resulting container was left to stand for 1 hour in a thermostatic chamber at 60°C, 25°C, or -20°C. While maintaining each of these temperatures, a 300g stainless steel chisel (with a hemispherical tip and a radius of 6.35mm) was dropped vertically onto the bottom of the container from a height of 100cm. After the drop, the bottom of the container was visually inspected and rated on the following three levels. A rating of A was considered a pass. A rating (marked as A in the table): A scratch can be seen at the point of impact, but the container has not been penetrated. B rating (marked as B in the table): A hole can be seen penetrating the container at the point of impact, but no other damage can be seen on the bottom of the container. C rating (marked as C in the table): Damage spreads across the entire bottom of the container.

[0090] 4.Heat resistance The container was left standing at 120°C for 8 hours, and the appearance and surface condition were visually inspected. If there was no change, it was evaluated as having heat resistance (marked as A in the table), and if there was a change in appearance, it was evaluated as not having heat resistance (marked as B in the table).

[0091] 5. Evaluation of evaporation residue The evaporation residue test is a test to measure the amount of substance that migrates from the sample to the leaching solution using a specified method, and was evaluated using the method using a one-sided extractor described in the Standards for Foods, Additives, etc. (Ministry of Health and Welfare Notification No. 370, December 28, 1959). The following leaching solutions were used: Water (organo corporation, ion-exchanged water treated with G-10, electrical conductivity: 1μS / cm or less, evaluated for elution in acidic foods with a pH of 5 or higher) 4% acetic acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade, diluted with the above water to 4.0% by mass, used to evaluate elution in acidic foods with a pH of 5 or less) 20% ethanol (Fujifilm Wako Pure Chemical Industries, Ltd., special grade, diluted with the above water to 20.0% by mass, used to evaluate elution into alcoholic beverages) n-Heptane (Fujifilm Wako Pure Chemical Industries, Ltd., special grade, evaluated for elution into oils, fats, and fatty products) The raw materials blended for the resin layer 110 used in the examples or comparative examples were used in a single extruder to produce a resin layer 110 having a layer thickness of 250 μm. The obtained resin layer was placed in a single-side extruder used in the test prescribed in Notification No. 370 of the Ministry of Health, Labor and Welfare. 2 The test solution was prepared by leaving the sample in contact with 600 ml of leaching solution for 2 hours.

[0092] 250 ml of the test solution (when heptane was used as the leaching solution, 250 ml of the test solution was transferred to a recovery flask and concentrated under reduced pressure to a few ml, and the flask was washed twice with 5 ml of heptane) was placed in a heat-resistant glass evaporating dish that had been dried at 105°C and evaporated to dryness in a water bath. Next, it was dried at 105°C for 2 hours and then allowed to cool in a desiccator. After cooling, it was weighed to determine the difference in weight a (mg) before and after the evaporation dish, and the amount of evaporation residue was calculated using the following formula. Evaporation residue (μg / ml) = ((ab) x 1,000) / sample volume of test solution (ml) where b: Blank test value (mg) obtained for the same amount of leaching solution as the test solution The amount of evaporation residue when each leaching solution was used was evaluated on a three-point scale as follows. In the table, the amount of evaporation residue is listed for each leaching solution (water, 4% acetic acid, 20% ethanol, heptane). A and B ratings were considered pass.

[0093] A rating (listed as A in the table): Less than 10 μg / ml B rating (marked as B in the table): Less than 30 μg / ml C rating (listed as C in the table): 30 μg / ml or more

[0094] 6.Layer thickness The thickness of each layer was determined by the following method. The sample was cut in the thickness direction using a microtome (REM-710 lithratome, manufactured by Yamato Koki Kogyo Co., Ltd.), and the obtained cross section was observed with a laser microscope (VHX-6000, manufactured by Keyence Corporation) to determine the layer thickness.

[0095] 7. Average particle size (D 50 ) Average particle size at 50% of cumulative volume (D 50 ) was measured using a laser diffraction / scattering particle size distribution analyzer (Partica LA-950 manufactured by Horiba Ltd.), and the powder to be measured was added to the flow cell of the analyzer, ultrasonicated, and then the particle size distribution was measured. Using the cumulative curve of the particle size distribution obtained, the particle size was calculated sequentially from the smallest particle size, and the particle size at which it reached 50% (volume basis) of the total was taken as the average particle size (D 50 ) was decided.

[0096] 8.Materials used (resin component) Polypropylene resin (PP resin): Polypropylene block copolymer (melting point 160°C) (Inorganic particles) Calcium carbonate: Shiraishi Calcium Co., Ltd., product name: Whiten SB Aka, D 50 =4.3μm Talc: Manufactured by Nippon Talc, product name: MS-W, D 50 =13.9μm Example 1 The raw materials blended for the resin layer 110 were adjusted in the blending amounts shown in Table 1 below.

[0097] [Table 1]

[0098] The raw materials formulated for the resin layer 110 were supplied to a single extruder (diameter 65 mm, L / D: 32), and the PP resin was also supplied to a single extruder (diameter 130 mm, L / D: 32) as a raw material for the surface layers 121 and 122. The raw materials melted and mixed at a predetermined temperature from each extruder were supplied to a two-kind, three-layer feedblock T-die. A three-layer sheet was extruded through a die adjusted to an appropriate lip clearance. The sheet was rolled with three polishing rolls and cooled to room temperature to form a three-layer sheet with a total thickness of 500 μm, which was then wound into a roll to form the laminate 100. The surface layer 121 had a thickness of 100 μm, the surface layer 122 had a thickness of 100 μm, and the resin layer 110 had a thickness of 300 μm.

[0099] The laminate produced as described above was deep-drawn to produce a container. The laminate 100 was molded into a cup-shaped test container with an opening diameter of 50 mm, a bottom diameter of 45 mm, and a height of 55 mm using a single-shot molding machine (manufactured by NK Enterprises). The evaluation results of the resulting resin composition, laminate and container are summarized in the following table.

[0100] [Table 2]

[0101] In Table 2, the Reference Example did not use inorganic particles, and therefore dispersibility was not evaluated, and is therefore marked with "-." In Comparative Example 2, the inorganic particles could not be uniformly dispersed, the dispersibility was rated C, a laminate could not be produced, and evaluation of moldability and other aspects was not possible, and is therefore marked with "-." In Comparative Example 1, it was confirmed that the elution into water and 4% acetic acid exceeded the standard value.

[0102] From the results of Examples 1 and 2 shown in Table 2, the resin composition of this embodiment was able to reduce the content of the resin component. Furthermore, even with the reduced content of the resin component, the resin composition had excellent dispersibility, and a laminate using this composition had excellent moldability, impact resistance, and heat resistance, and evaluation of the evaporation residue confirmed that the amount of eluted material was extremely small. [Industrial Applicability]

[0103] It has been found that the resin composition, resin layer, laminate, container, and article of this embodiment have excellent dispersibility while reducing the content of resin components, and that containers and the like using them satisfy physical requirements (moldability, impact resistance, heat resistance). Furthermore, because elution from them is suppressed, the container of this embodiment is suitable for use in food and the like. [Explanation of symbols]

[0104] 1 Thickness direction 2 Width direction 3 Longitudinal direction 100 laminate 110 Resin layer 120 Surface layer 121 Surface layer 122 Surface layer

Claims

1. Two or more types of inorganic particles; One or more resin components, The total content of the inorganic particles is 10.0% by mass or more and 80.0% by mass or less, A resin composition, wherein the total content of the resin components is 20.0% by mass or more and 70.0% by mass or less.

2. 2. The resin composition according to claim 1, wherein a value obtained by dividing the total content of the resin components by the total content of the inorganic particles (total content of the resin components (mass g) / total content of the inorganic particles (mass g)) is 0.4 or more and 2.0 or less.

3. The resin composition according to claim 1 or 2, wherein the inorganic particles contain calcium carbonate and talc.

4. The particle size distribution (D ５０ 4. The resin composition according to claim 3, wherein the average particle size is 1.0 μm or more and 15.0 μm or less.

5. The particle size distribution of the talc (D ５０ 5. The resin composition according to claim 3, wherein the average particle size is 3.0 μm or more and 20.0 μm or less.

6. The resin composition according to any one of claims 3 to 5, wherein the content of the calcium carbonate relative to the total amount of the inorganic particles is 3.0 mass% or more and 50.0 mass% or less.

7. The resin composition according to any one of claims 3 to 6, wherein the content of the talc relative to the total amount of the inorganic particles is 40.0 mass% or more and 95.0 mass% or less.

8. 8. The resin composition according to claim 3, wherein a value obtained by dividing the content of the talc contained in the inorganic particles by the content of the calcium carbonate (the content of the talc (mass g) / the content of the calcium carbonate (mass g)) is 1.0 or more and 10.0 or less.

9. The resin composition according to any one of claims 1 to 8, comprising one or more thermoplastic resins as the resin component.

10. The resin composition according to claim 9 , wherein the thermoplastic resin comprises a polyolefin-based resin.

11. The resin composition according to any one of claims 1 to 10, further comprising an additive.

12. A resin layer using the resin composition according to any one of claims 1 to 11.

13. A laminate comprising the resin layer according to claim 12 and one or two surface layers.

14. A container comprising the resin layer of claim 12.

15. A container comprising the laminate of claim 13.

16. An article comprising the container of claim 14 or 15 and contents.

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