Resin composition, resin layer, laminate, and container

Abstract

To provide a resin composition, a resin layer, a laminate, and a container which employ a resin component having a controlled molecular weight distribution, thereby achieving excellent dispersibility of inorganic particles and ensuring that containers and the like produced therefrom meet physical requirements (moldability, impact resistance, and heat resistance).SOLUTION: The present invention provides a resin composition comprising one or more resin components and one or more inorganic particles, wherein, in a differential molecular weight distribution curve of the resin component as measured by gel permeation chromatography (GPC), a peak having a peak top in the range of 4.5 to 6.5 has a half width of 0.90 to 2.00. The present invention also provides a resin layer, a laminate, and a container which employ the resin composition.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 of inorganic particles by using a resin component with a controlled molecular weight distribution, and that enable containers and the like made therefrom to satisfy physical requirements (moldability, impact resistance, heat resistance). [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 one or more resin components and one or more inorganic particles, wherein the half-width of a peak having a peak top between 4.5 and 6.5 in a differential molecular weight distribution curve of the resin component as determined by resin permeation chromatography (GPC) is 0.90 or more and 2.00 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, by using a resin component with a controlled molecular weight distribution, it is possible to provide a resin composition, a resin layer, a laminate, and a container that have excellent dispersibility of inorganic particles and that satisfy the physical requirements (moldability, impact resistance, heat resistance) of containers and the like that use the resin composition, resin layer, laminate, and container. [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] FIG. 1 is a conceptual diagram of how to determine the half-value width. [Figure 5] 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 the dispersibility of inorganic particles or impact resistance.

[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 a resin composition having a specific molecular weight distribution.

[0010] Currently, resin compositions used for 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 their low dispersibility in the resin component, there is a limit to the upper limit of their content. It is also known that as the content of inorganic particles increases, the moldability and impact resistance described above decrease, and the moldability when molding the resin layer into a container also decreases.

[0011] Recently, there has been a strong demand for the content of the resin component to be 50.0% by mass or less in the resin composition. However, achieving this has been difficult using only the resin components that have been used up to now, as it is difficult to uniformly disperse inorganic particles 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 required characteristics.

[0012] In the present disclosure, "impact resistance" refers to the ability of a container to not break or to be suppressed when dropped. By preventing the container from breaking, damage to the contents is suppressed.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] It has been found that the resin composition of the present disclosure uses a resin component with a controlled molecular weight distribution, thereby improving the dispersibility of inorganic particles, increasing the content thereof, and reducing the content of the resin component in the resin composition, while providing a resin composition that is excellent in dispersibility and that satisfies the physical requirements (moldability, impact resistance, heat resistance) of containers and the like that use the resin composition. In particular, it has been found that the resin composition of the present disclosure has significantly improved impact resistance at low temperatures. Whether the molecular weight distribution of the resin component is controlled can be determined by the peak top position of the resin component (logM top) and half-width are within a specific range.

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

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

[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 contain one or more resin components and one or more inorganic particles, and to be a resin composition in which, in a differential molecular weight distribution curve of the resin components as measured by resin permeation chromatography (GPC), the half-value width of a peak having a peak top between 4.5 and 6.5 is 0.90 or more and 2.00 or less.

[0022] Hereinafter, in this disclosure, the term "differential molecular weight distribution curve" refers to a curve obtained by plotting the concentration fraction (W) differentiated by the logarithm of the molecular weight M, relative to logM determined from the molecular weight M calibrated with monodisperse polystyrene (PS) in GPC measurement. Log refers to a common logarithm with a base of 10. For details, see the explanations, examples, and FIG. 4 below.

[0023] The inorganic particles are hardly soluble in the resin component and may be partially dissolved, but it is preferable that the resin composition is in a state in which the inorganic particles are dispersed in the resin composition.

[0024] 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.

[0025] 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.

[0026] In the present disclosure, for example, "diluting by two times" means that 1 g by mass of a resin component is added to 1 g by mass of a masterbatch, and stirred as necessary to obtain a resin composition.

[0027] The resin composition of this embodiment has a resin layer that exhibits excellent impact resistance, and therefore can be preferably used as a container for the contents described below. Examples of suitable contents 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 of its excellent impact resistance, particularly at low temperatures, the resin composition is suitable for use as a container for frozen foods and other foods to be used at low temperatures.

[0028] In addition, because it has excellent moldability, it is excellent as a container that requires dimensional stability for precision equipment, etc. Furthermore, because it has excellent impact resistance even at high temperatures, it can withstand heating in a microwave oven, etc., and has excellent properties as a container that is expected to be used over a wide temperature range.

[0029] In addition, the resin composition of the present embodiment has excellent dispersibility of inorganic particles in the resin component, allowing the content of inorganic particles to be increased. Furthermore, since the inorganic particles are less likely to precipitate from the resin composition, the resin composition has long-term storage stability and is easy to produce, which is preferable because it also has excellent productivity.

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

[0032] <Resin component> The resin component must have a peak half-width of 0.90 to 2.00 in a differential molecular weight distribution curve measured by resin permeation chromatography (GPC), the peak having a peak top between 4.5 and 6.5.

[0033] 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.

[0034] The total content of the resin components in the resin composition of this embodiment is preferably 20.0 mass % or more and 70.0 mass % or less. The measurement method by GPC, the method of identifying peaks, and the half width of peaks will be described later.

[0035] The peak top in the specified region can be achieved by appropriately adjusting the content of the multiple components (hereinafter referred to as polymers for the sake of explanation) that make up the resin component. The polymer itself has a molecular weight distribution, and because molecular weight distributions are generally additive, when multiple polymers are used, the peak top position can be easily adjusted by appropriately determining the content of each polymer if the molecular weight distribution of each polymer is known. Similarly, with regard to the half-width of the peak, if the molecular weight distribution of each polymer is known, the content of each polymer can be adjusted to the desired half-width through simulation using a spreadsheet application or the like. When the polymer is obtained by polymerizing a specific monomer, if the differential molecular weight distribution curve of this polymer has the required peak top and half-width, it can be used as is. However, although it can be achieved by selecting polymerization conditions such as temperature conditions, catalyst type selection, catalyst amount, solvent selection, and solvent amount, it is generally difficult to achieve the required range of the differential molecular weight distribution curve of the polymer. Furthermore, even if the polymerization conditions can be determined, it is extremely difficult to scale up the process to an industrial scale and maintain those conditions throughout the polymerization reaction. Therefore, in terms of production efficiency, it is preferable to prepare a plurality of polymers with different differential molecular weight distribution curves and mix them appropriately so that the peak top and half width are at the desired positions.

[0036] The peak top 6 means the highest point in the range of 4.5 to 6.5 in log M, which is the horizontal axis of the differential molecular weight distribution curve, and the log M topFrom the above, the molecular weight M of peak top 6 top can be calculated.

[0037] logM top is preferably in the range of 4.7 to 6.2, more preferably in the range of 4.8 to 6.0, even more preferably in the range of 5.0 to 5.7, and even more preferably in the range of 5.1 to 5.6. When two or more peak tops exist within the above range, the highest peak is regarded as the peak top.

[0038] In order to simultaneously satisfy at least two of the following requirements: to improve impact resistance, to improve moldability, to improve long-term storage stability, to increase the total content of the inorganic particles to provide an environmentally friendly product by reducing the amount of resin used, and to improve heat resistance, the half-value width of the peak is preferably 0.95 to 1.90, more preferably 0.97 to 1.80, even more preferably 0.98 to 1.70, and even more preferably 0.99 to 1.60.

[0039] The half-width 9 of the peak of the resin component refers to the half-width of the peak to which the peak top 6 belongs. When multiple peaks are present and cannot be separated, the half-width refers to the combined half-width of the inseparable peaks. Figure 4 shows an example of multiple inseparable peaks. For example, in a differential molecular weight distribution curve obtained as described below, when the range of logM between 2.0 and 8.0 is set to 9.0 cm, dW / dlogM of peak top 6 is defined as the peak top height 8, and the width at 50% of this peak top height (the width is the absolute value of the difference between logM1 and logM2 at the two points where a line parallel to the horizontal axis at 50% of the peak top height intersects with the curve to which peak top 6 belongs in the differential molecular weight distribution curve) is the half-width 9.

[0040] The resin component is dissolved in tetrahydrofuran (THF) and subjected to resin permeation chromatography (GPC) to obtain a differential molecular weight distribution curve 5. The M represents the molecular weight in styrene equivalent terms using standard polystyrene (monodisperse).

[0041] From this differential molecular weight distribution curve 5, logM top and M top The peak top can be calculated by logM top means.

[0042] The GPC measurement is preferably carried out, for example, as follows. Apparatus: Size exclusion chromatograph (Tosoh HLC-8320GPC) Column temperature: 40℃ Detection method: Refractive index detector (RID) Mobile phase: tetrahydrofuran (THF, stabilizer-free) Sample concentration: 2% by mass Column: TSKgel Super HM-M (two columns in series) Calibration curve: Created using standard polystyrene (monodisperse)

[0043] In order to simultaneously satisfy at least two of the following: to improve impact resistance, to improve moldability, and to improve long-term storage stability, the lower limit of the total content of the resin components in the resin composition of this embodiment 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 simultaneously satisfy at least two of the following: to increase the total content of the inorganic particles, to provide an environmentally friendly product with a reduced amount of resin used, and to 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 excellently preferably 60.0% by mass or less, and even more excellently preferably 60.0% by mass or less.

[0044] 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.

[0045] 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.

[0046] <<Thermoplastic resin>> The resin component preferably contains one or more thermoplastic resins.

[0047] 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.

[0048] 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.

[0049] Examples of the thermoplastic resin include polyolefin resins, polyester resins, and polystyrene resins, with polyolefin resins being preferred due to their good moldability.

[0050] In order to improve impact resistance, the mass average molecular weight (Mw) of the polyolefin resin is preferably 30,000 or more and 1,000,000 or less, more preferably 50,000 or more and 800,000 or less, even more preferably 70,000 or more and 700,000 or less, and even more preferably 90,000 or more and 600,000 or less.

[0051] In order to improve impact resistance, the polydispersity (Mw / Mn) of the polyolefin resin is preferably 1.5 or more and 9.0 or less, more preferably 2.0 or more and 8.0 or less, even more preferably 2.5 or more and 7.5 or less, and even more preferably 3.0 or more and 7.0 or less.

[0052] 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.

[0053] 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.

[0054] In order to achieve the above Tg range, it is preferable to add a metallocene polyolefin resin to the polyolefin resin.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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).

[0059] 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.

[0060] The combined use of a metallocene polyolefin resin and a polyethylene resin produced without using a metallocene catalyst is preferred because it makes it easier to adjust the peak molecular weight and half width according to requirements.

[0061] (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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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).

[0066] (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.

[0067] 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.

[0068] 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-methylpenten-1-yl copolymer, and ethylene-octen-1-yl copolymer.

[0069] <Inorganic particles> The inorganic particles used in this embodiment are particles classified as inorganic substances, and their median diameter (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.

[0070] 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.

[0071] More specifically, 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 are preferred, calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, talc, carbon black, zeolite, molybdenum, diatomaceous earth, and bentonite are more preferred, calcium carbonate, silica, alumina, and talc are even more preferred, and calcium carbonate is even more preferred.

[0072] 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.

[0073] 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, the contents will be altered, so when basic particles are used, it is more preferable to use them 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.

[0074] The inorganic particles may be used alone or in combination of two or more. When two or more types are used in combination, preferred combinations include 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. More preferred are 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. 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.

[0075] The total content of the inorganic particles in the resin composition of the present embodiment is preferably 10.0% by mass or more and 80.0% by mass or less.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] <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.

[0082] For example, as the ultraviolet absorber, a benzotriazole-based compound is preferred.

[0083] 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.

[0084] 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.

[0085] [Resin layer] The resin layer of the present embodiment is required to be a resin layer using the above-mentioned resin composition.

[0086] 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.

[0087] [Laminate] The laminate of this embodiment must include the resin layer and one or two surface layers.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] <<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.

[0092] The surface layer is preferably the thermoplastic resin layer, and more preferably the PP resin layer that is substantially free of inorganic particles.

[0093] 〔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.

[0094] [Goods] The article of this embodiment must include the container and the contents described below.

[0095] <<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.

[0096] [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.

[0097] The resin composition of this embodiment can be produced, for example, by the following production method.

[0098] 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.

[0099] 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. 5, 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.

[0100] 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.

[0101] 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.

[0102] [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.

[0103] The resin composition, resin layer, laminate, container and article of the present embodiment preferably satisfy the following items [1] to

[13] . [1] A resin composition comprising one or more resin components and one or more inorganic particles, wherein the differential molecular weight distribution curve of the resin component measured by gel permeation chromatography (GPC) has a half-width of 0.90 to 2.00, the half-width of a peak having a peak top between 4.5 and 6.5. [2] The resin composition according to [1], which contains one or more thermoplastic resins as the resin component. [3] The resin composition according to [2], wherein the thermoplastic resin contains a polyolefin resin. [4] The resin composition according to any one of [1] to [3], wherein the polydispersity (Mw / Mn) of the resin component is 1.5 or more and 9.0 or less. [5] The resin composition according to any one of [1] to [4], wherein the inorganic particles contain calcium carbonate. [6] The median diameter (D 50 The resin composition according to any one of [1] to [5], wherein the average particle size is 1 μm or more and 100 μm or less. [7] The resin composition according to any one of [1] to [6], 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 (g by mass) / total content of the inorganic particles (g by mass)) is 0.4 or more and 2.0 or less. [8] The resin composition according to any one of [1] to [7], further comprising an additive. [9] A resin layer using the resin composition according to any one of [1] to [8].

[10] A laminate comprising the resin layer according to [9] and one or two surface layers.

[11] A container comprising the resin layer according to [9].

[12] A container comprising the laminate according to

[10] .

[13] An article comprising the container and contents described in

[11] or

[12] . [Example]

[0104] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples.

[0105] (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.

[0106] 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 were no problems with the manufacturing process. C rating (marked as C in the table): Defects were found on the entire bottom of the container.

[0107] 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.

[0108] 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 judged to have heat resistance (marked A in the table, and rated as passing), and if there was a change in appearance, it was judged to have no heat resistance (marked B in the table, and rated as failing).

[0109] 5.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.

[0110] 6. 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.

[0111] 7.Molecular weight etc. The peak top, half width, number average molecular weight (Mn), weight average molecular weight (Mw), average molecular weight (Mz) and polydispersity (Mw / Mn) of the resin components used in each of the Examples and Comparative Examples were determined as follows.

[0112] Tetrahydrofuran (THF) was added to the resin component to be measured and stirred to prepare a homogeneous solution of 2 mg / mL. The resulting solution was filtered through a membrane filter (PTFE, pore size: 0.45 μm), and the filtrate was subjected to molecular weight measurement as follows. If inorganic particles were present, they were removed. Apparatus: Size exclusion chromatograph (Tosoh HLC-8320GPC) Eluent: tetrahydrofuran (stabilizer-free) Column: TSKgel Super HM-M (two columns in series) Detector: differential refractometer Measurement temperature: 40℃ Flow rate: 0.6mL / min Injection volume: 20μL Molecular weight calculation conditions Relative molecular weight values ​​were calculated based on standard substances. Standard material: 12 standard polystyrenes (molecular weight 504 to 1.09 x 10 6 ) Calibration curve: cubic approximation curve

[0113] From the obtained results, a differential molecular weight distribution curve (differential molecular weight distribution curve) was created, with the horizontal axis representing logM, calculated from the molecular weight M calibrated with monodisperse polystyrene (PS), and the vertical axis representing the value (dW / dlogM) obtained by differentiating the concentration fraction (W) with the logarithm of the molecular weight M (Figure 4). From the obtained differential molecular weight distribution curve, a peak top (logM) was found in the range corresponding to a molecular weight of 4.5 or more and 6.5 or less in terms of monodisperse polystyrene. top ) for the peak having the peak top 6, a line parallel to the horizontal axis is drawn at 50% of the height 8 of the peak top 6, and the absolute value of the difference between logM1 and logM2 at the two points where this line intersects with the curve to which the peak top 6 belongs in the differential molecular weight distribution curve is taken as the half-width 9. The line extending vertically from the peak top 6 intersects with the horizontal axis top to the molecular weight M top It was decided that:

[0114] 8.Materials used (resin component) Polypropylene resin (PP resin): Polypropylene block copolymer was used in appropriate combination. top The half-width, Mw and Mw / Mn are summarized in the table below. In Table 1, "-" indicates that the data was not measured.

[0115] [Table 1]

[0116] Example 1 49 parts by mass of resin component 1 and inorganic particles (calcium carbonate: manufactured by Shiraishi Calcium Co., Ltd., product name: Whiten SB Aka, D 50 51 parts by mass of a PP resin (4.3 μm thick) was 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 surface layers 121 and 122. The raw materials were melted and mixed at a predetermined temperature from each extruder and 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 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.

[0117] 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).

[0118] The results of dispersibility, moldability, impact resistance and heat resistance are shown in Table 2. Examples 2 and 3 The laminate and test container of Example 2 were produced in the same manner as in Example 1, except that resin component 1 was replaced with resin component 2, and the laminate and test container of Example 3 were produced in the same manner as in Example 1, except that resin component 1 was replaced with resin component 3.

[0119] The results of dispersibility, moldability, impact resistance and heat resistance are shown in Table 2. (Comparative Examples 1 and 2) A laminate and a test container were produced in the same manner as in Example 1, except that resin component 1 was replaced with resin component 4 (Comparative Example 1) and resin component 1 was replaced with resin component 5 (Comparative Example 2).

[0120] The results of dispersibility, moldability, impact resistance and heat resistance are shown in Table 2. In Table 2, "-" indicates that the laminate could not be produced and therefore could not be evaluated.

[0121] [Table 2]

[0122] It was confirmed that the resin compositions of Examples 1, 2, and 3 had no practical problems. In contrast, the resin composition of Comparative Example 1, which used resin component 4, had poor dispersibility of inorganic particles, and the moldability, impact resistance, and heat resistance of the test container were poor. The resin composition of Comparative Example 2, which used resin component 5, had even lower dispersibility than Comparative Example 1, and it was not possible to prepare a laminate using this composition, so it was not possible to evaluate the moldability, impact resistance, and heat resistance. [Industrial Applicability]

[0123] The resin composition, resin layer, laminate, container, and article of this embodiment use a resin component with a controlled molecular weight distribution, which provides excellent dispersibility of inorganic particles, and containers and the like using such resin components satisfy physical requirements (moldability, impact resistance, heat resistance), so the containers of this embodiment are suitable for use in food products, etc. [Explanation of symbols]

[0124] 1 Thickness direction 2 Width direction 3 Longitudinal direction 5 Differential molecular weight distribution curve 6 Peak Top 7 logM at the peak top top 8 Peak top height 9 Peak half-width 10 logM1 when molecular weight M1 11 logM2 when molecular weight M2 100 laminate 110 Resin layer 120 Surface layer 121 Surface layer 122 surface layer

Claims

1. One or more resin components; One or more types of inorganic particles, A resin composition, wherein in a differential molecular weight distribution curve of the resin component by resin permeation chromatography (GPC), the half-value width of a peak having a peak top between 4.5 and 6.5 is 0.90 or more and 2.00 or less.

2. The resin composition according to claim 1 , wherein the resin component comprises one or more thermoplastic resins.

3. The resin composition according to claim 2 , wherein the thermoplastic resin comprises a polyolefin resin.

4. The resin composition according to claim 1, wherein the polydispersity (Mw / Mn) of the resin component is 1.5 or more and 9.0 or less.

5. The resin composition according to claim 1 , wherein the inorganic particles contain calcium carbonate.

6. The median diameter (D ５０ 2. The resin composition according to claim 1, wherein the average particle diameter is 1 μm or more and 100 μm or less.

7. 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.

8. The resin composition according to claim 1 , further comprising an additive.

9. A resin layer using the resin composition according to claim 1.

10. A laminate comprising the resin layer according to claim 9 and one or two surface layers.

11. A container comprising the resin layer of claim 9.

12. A container comprising the laminate of claim 10.

13. An article comprising the container and contents of claim 11 or 12.

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