Container

Abstract

To provide a technique capable of preventing contamination of contents with impurities in a container highly filled with an inorganic powder.SOLUTION: The present invention provides a container. The container comprises a container body having an opening, and a lid for closing the opening. The opening includes a first threaded portion having threads formed thereon. The lid includes a second threaded portion to be screwed onto the first threaded portion. The first and second threaded portions contain an inorganic powder and a thermoplastic resin. The content of the inorganic powder is more than 50.0 mass% and less than or equal to 80.0 mass% relative to the total mass of the container. The inorganic powder satisfies all of predetermined requirements.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a container.

Background Art

[0002] In recent years, from the viewpoint of reducing the environmental load and the like, attempts have been made to highly fill resin molded products with inorganic substance powders (for example, Patent Document 1). Resin molded products highly filled with inorganic substance powders are generally superior in mechanical properties and the like compared to the resin alone.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the inventor has found that, for a container highly filled with an inorganic substance powder, while being excellent in strength and the like, the screwing portion (usually, thread) between the container body and the lid is liable to be chipped. In particular, it has been found that when a load is applied in a state where the lid is not fully closed (that is, in a state where the screwing between the container body and the lid is incomplete), the thread can be easily damaged. Debris and the like generated due to the damage of the screwing portion may impair the quality of the container contents.

[0005] The debris and the like contain impurities such as lead contained in the inorganic substance powder, and improvement is desired from the viewpoint of safety.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a technique capable of suppressing the mixing of impurities into the contents in a container highly filled with an inorganic substance powder.

Means for Solving the Problems

[0007] The inventors of the present invention have found that the above problems can be solved by blending an inorganic substance powder that satisfies predetermined requirements with respect to the content of trace components in a container highly filled with the inorganic substance powder, and have thus completed the present invention. More specifically, the present invention provides the following.

[0008] (1) A container, wherein the container comprises a container body having an opening and a lid for closing the opening, the opening is provided with a first screwing portion having a screw thread formed thereon, the lid is provided with a second screwing portion that is screwed with the first screwing portion, the first screwing portion and the second screwing portion contain an inorganic substance powder and a thermoplastic resin, the content of the inorganic substance powder is more than 50.0% by mass and 80.0% by mass or less with respect to the entire container, the inorganic substance powder mainly contains calcium carbonate and satisfies all of the following requirements: a container. (Requirement 1) The content of lead per 1 g of the inorganic substance powder is 20 μg or less. (Requirement 2) When the inorganic substance powder is 100% by mass, the total amount of alkali metals and magnesium is 1.0% by mass or less.

[0009] (2) The resin composition according to (1), wherein the content of the calcium carbonate is 80% by mass or more with respect to the inorganic substance powder.

[0010] (3) The container according to (1), wherein the calcium carbonate contains heavy calcium carbonate.

[0011] (4) The container according to (1), wherein the inorganic substance powder further satisfies the following requirement. (Requirement 3) The content of arsenic per 1 g of the inorganic substance powder is 3 μg or less.

[0012] (5) The container according to (3), wherein the heavy calcium carbonate contains heavy calcium carbonate having an average particle diameter of 0.7 μm or more and 6.0 μm or less by the air permeability method according to JIS M-8511:2014.

[0013] (6) The container according to (1), wherein the thermoplastic resin contains a polypropylene-based resin and / or a polyethylene-based resin.

[0014] (7) The container according to (6), wherein the polyethylene-based resin contains high-density polyethylene and / or linear low-density polyethylene.

[0015] (8) The container according to (6), wherein the polypropylene-based resin contains a polypropylene homopolymer and / or a polypropylene block polymer.

[0016] (9) The container according to (1), wherein the container is obtained by injection molding or compression molding.

[0017] (10) The container according to (1), wherein the container is a container for pharmaceuticals.

[0018] (11) The container according to (1), wherein the container is a container for cosmetics.

Advantages of the Invention

[0019] According to the present invention, a technique is provided that can suppress the mixing of impurities into the contents in a container highly filled with inorganic substance powder.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

[0021] <Container> The container according to one embodiment of the present invention can satisfy all of the following requirements. · The container includes a container body having an opening and a lid for closing the opening. · The opening is provided with a first threaded portion having a thread formed thereon. · The lid is provided with a second threaded portion that is screwed with the first threaded portion. · The first threaded portion and the second threaded portion contain an inorganic substance powder and a thermoplastic resin. · The content of the inorganic substance powder is more than 50.0 mass% and 80.0 mass% or less with respect to the whole container. · The inorganic substance powder mainly contains calcium carbonate powder and satisfies all of the following requirements. (Requirement 1) The content of lead per 1 g of the inorganic substance powder is 20 μg or less. (Requirement 2) When the inorganic substance powder is 100 mass%, the total amount of alkali metals and magnesium is 1.0 mass% or less.

[0022] The inorganic substance powder is known to have an effect of imparting mechanical properties to resin products. For example, the higher the content of the inorganic substance powder, the easier it is to enhance the drop impact resistance. However, the inventor has specified that in the case of a container in which the lid and the body are fitted by a screw, the higher the content of the inorganic substance powder, the more likely it is that the thread will be damaged even though the mechanical properties of the whole container are good. In particular, when a vertical load is applied to the lid in a state where the lid is not fully closed (that is, in a state where the screwing between the container body and the lid is incomplete), the thread is easily damaged. This point can be said to be a new problem peculiar to a container with a high filling of an inorganic substance powder.

[0023] On the other hand, fragments and the like generated due to the breakage of the threaded portion may impair the quality of the container contents (for example, pharmaceuticals, cosmetics, etc.). In particular, the mixing of impurities such as lead contained in the inorganic substance powder into the contents should be avoided.

[0024] In a container with a low content of the inorganic substance powder (for example, one in which the content of the inorganic substance powder is 50.0 mass% or less with respect to the container), the thread is hardly damaged in the first place, and the above problems in the present invention do not exist.

[0025] In one embodiment of the present invention, "comprising component A" means substantially not containing components other than component A. In one embodiment of the present invention, "substantially not containing component B" includes, for example, an aspect of completely not containing component B.

[0026] In one embodiment of the present invention, "mainly containing component A" means that the content of component A is more than half with respect to the entire predetermined components. For example, "mainly containing component A" includes that the content of component A is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, even more preferably 99% by mass or more, and most preferably 100% by mass with respect to the entire predetermined components.

[0027] Hereinafter, the configuration of the container according to one embodiment of the present invention will be described in detail.

[0028] (1) Structure of the container In one embodiment of the present invention, the container includes a container body having an opening and a lid for closing the opening. The opening is provided with a first screwing portion formed with a screw thread. The lid is provided with a second screwing portion screwed with the first screwing portion. The container as described above includes, for example, a container provided with a screw-type fitting lid.

[0029] The "container body" in the container is a part having a space for storing the contents of the container. The shape and size of the container body can be appropriately set according to the use of the container and the like.

[0030] The "opening" in the container is a part for taking things in and out of the container, and is usually provided at one location in the container body. The shape and size of the opening can be appropriately set according to the use of the container and the like.

[0031] The "lid" in the container is a part for sealing the opening of the container body. The shape and size of the lid can be appropriately set according to the shape and size of the opening and the like.

[0032] Thread portions are formed on the opening and the lid, respectively, and are configured to be screwed together with each other. "Screwing together" includes screwing the container body and the lid by engaging the threads with each other. The "thread portion" includes, in each of the container body and the lid, the thread and the portion including the surface on which the thread is provided. For example, the thread portion in the container body may be the entire portion called the neck (the portion where the thread is provided). The thread portion in the lid may be the entire portion parallel to the neck of the container body.

[0033] The shape, size, etc. of the container are not particularly limited. For example, the container can be in any form such as cylindrical, bottle-shaped, wide-mouthed, jar-shaped, etc.

[0034] The composition of the container is not particularly limited except that the first thread portion and the second thread portion each contain an inorganic substance powder and a thermoplastic resin.

[0035] The types and amounts of the inorganic substance powder and the thermoplastic resin incorporated in the container body and the lid may be the same or different.

[0036] The present invention encompasses all of the following aspects. · The first thread portion and the second thread portion have the same composition. · The entire container body has the same composition. · The entire lid has the same composition. · The entire container body and the entire lid have the same composition.

[0037] From the viewpoint of economy and the like, a preferred embodiment of the present invention encompasses the aspect in which the entire container body and the entire lid have the same composition.

[0038] The dimensions of each part of the container can be appropriately set according to the shape of the container adopted, etc. For example, one aspect of the present invention encompasses a container that satisfies the following dimensions.

[0039] [Dimensions of the container body] Barrel diameter: 20 to 150 mm Height: 10 to 150 mm Thread diameter: 20 to 150 mm Thread height: 1 to 5 mm Head (part where the thread is provided): 20 mm

[0040] [Dimensions of the lid] Lid outer diameter: 20 to 150 mm Height: 10 to 50 mm Thread height: 1 to 5 mm

[0041] (2) Thermoplastic resin The thermoplastic resin constituting the container and the screwing part is not particularly limited, and resins that can be usually blended in resin molded products can be adopted. The thermoplastic resin may be used alone or in combination of two or more.

[0042] (2-1) Types of thermoplastic resin The thermoplastic resin is not particularly limited, but from the viewpoint of moldability and the like, polyolefin resins, polyester resins, polystyrene resins, etc. can be mentioned.

[0043] In one embodiment of the present invention, the thermoplastic resin preferably contains a polyolefin resin, and more preferably consists of a polyolefin resin. In one embodiment of the present invention, the "polyolefin resin" means a polyolefin resin having an olefin component unit as a main component. "Having an olefin component unit as a main component" means that the olefin component unit is contained in the polyolefin resin in an amount of 50% by mass or more (preferably 75% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more). In addition, the production method of the polyolefin resin used in the present invention is not particularly limited, and any method such as a method using a Ziegler-Natta catalyst, a metallocene catalyst, a radical initiator (oxygen, peroxide, etc.) can be used.

[0044] Examples of the polyolefin resin include polypropylene resins and polyethylene resins. From the viewpoint of being able to easily suppress breakage of the container and further being able to easily achieve a good appearance and the like, the thermoplastic resin preferably contains a polypropylene resin and / or a polyethylene resin, and more preferably consists of a polypropylene resin and / or a polyethylene resin.

[0045] (2-1-1) Polypropylene resin The polypropylene resin in the present invention includes a resin in which the propylene component unit is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and most preferably 80% by mass or more.

[0046] Examples of the polypropylene resin include polypropylene homopolymers (propylene homopolymers) and copolymers of propylene and other α-olefins (capable of copolymerizing with propylene). Examples of the "other α-olefins" include α-olefins having 4 to 10 carbon atoms (ethylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, 3-methyl-1-hexene, etc.).

[0047] Examples of the polypropylene homopolymer include linear or branched polypropylenes showing various stereoregularities (isotactic, syndiotactic, atactic, hemiisotactic, etc.).

[0048] The copolymer of propylene may be any of a polypropylene random copolymer (random copolymer), a polypropylene block copolymer (block copolymer), a binary copolymer, a ternary copolymer, etc. Specifically, an ethylene-propylene random copolymer, a butene-1-propylene random copolymer, an ethylene-butene-1-propylene random terpolymer, an ethylene-propylene block copolymer, etc. are included.

[0049] Among the above polypropylene-based resins, resins containing polypropylene homopolymer and / or polypropylene block polymer are preferred, and resins consisting of polypropylene homopolymer and / or polypropylene block polymer are more preferred.

[0050] (2-1-2) Polyethylene-based resin The polyethylene-based resin in the present invention includes resins in which the ethylene component unit is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and most preferably 80% by mass or more.

[0051] Examples of the polyethylene-based resin include high-density polyethylene (HDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-propylene-butene-1 copolymer, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-4-methylpentene-1 copolymer, ethylene-octene-1 copolymer, and the like.

[0052] As the polyethylene-based resin, resins containing high-density polyethylene and / or linear low-density polyethylene are preferred, and resins consisting of high-density polyethylene and / or linear low-density polyethylene are more preferred.

[0053] The high-density polyethylene preferably has an MFR (190 °C, 21.6 kg) according to JIS K 6922-1:2018 (ISO1133) of 5 g / 10 min or more and 15 g / 10 min or less, and more preferably 7 g / 10 min or more and 13 g / 10 min or less.

[0054] The linear low-density polyethylene preferably has an MFR (190 °C, 2.16 kg) according to JIS K 6922-1:2018 (ISO1133) of 0.5 g / 10 min or more and 1.5 g / 10 min or less, and more preferably 0.7 g / 10 min or more and 1.3 g / 10 min or less.

[0055] In a resin containing high-density polyethylene and linear low-density polyethylene, the mass ratio of the two (high-density polyethylene: linear low-density polyethylene) is preferably 90:10 to 50:50, more preferably 92:8 to 50:50, and even more preferably 94:6 to 50:50.

[0056] (2-2) Blending amount of thermoplastic resin The content of the thermoplastic resin can be appropriately set according to the blending amount of the inorganic substance powder and the like.

[0057] From the viewpoint of moldability and the like, the content of the thermoplastic resin is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more based on the whole container.

[0058] From the viewpoint of blending a sufficient amount of the inorganic substance powder and imparting strength to the whole container, the content of the thermoplastic resin is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less based on the whole container.

[0059] From the viewpoint of enhancing the flexibility of the screwing part of the container and being easy to suppress breakage, the content of the thermoplastic resin is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more based on the screwing part of the container. It is preferable that either the container body of the container or the screwing part of the lid satisfies the above requirements, and it is more preferable that both satisfy the requirements.

[0060] Although the content of the thermoplastic resin is not particularly limited, it is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less based on the screwing part of the container. It is preferable that either the container body of the container or the screwing part of the lid satisfies the above requirements, and it is more preferable that both satisfy the requirements.

[0061] (3) Inorganic substance powder The inorganic substance powder constituting the container and the screwing part is not particularly limited except that it mainly contains calcium carbonate powder, and an inorganic substance powder that can be usually blended in a resin molded product can be adopted. The inorganic substance powder may be used alone or in combination of two or more.

[0062] (3-1) Calcium carbonate powder As the calcium carbonate powder, any of heavy calcium carbonate powder and light calcium carbonate powder may be used. "Heavy calcium carbonate" is calcium carbonate obtained by mechanically pulverizing (dry method, wet method, etc.) natural raw materials (such as limestone) mainly composed of CaCO3. "Light calcium carbonate" is calcium carbonate prepared by a synthetic method (such as a chemical precipitation reaction). Therefore, heavy calcium carbonate and light calcium carbonate are clearly distinguished from each other.

[0063] The difference between heavy calcium carbonate and light calcium carbonate can be specified, for example, from the roundness calculated based on the analysis of the SEM image. The roundness of the heavy calcium carbonate powder is, for example, in the range of 0.50 or more and 0.95 or less. The roundness of the light calcium carbonate powder is, for example, approximately 1.00.

[0064] In one embodiment of the present invention, "roundness" is a value represented by the following formula and is an index of the degree of irregularity of particles. The closer the roundness is to "1" (the maximum value), the closer it is to a perfect circle, and the lower the numerical value, the higher the degree of irregularity. "Roundness" = (projected area of particles) / (area of a circle having the same perimeter as the projected perimeter of the particles)

[0065] Due to its manufacturing method, the shape of heavy calcium carbonate is not constant, and although it has a low cost, it is easy to stably impart good mechanical properties to resin molded products. Therefore, preferred embodiments of the present invention include embodiments in which calcium carbonate contains heavy calcium carbonate powder and embodiments in which calcium carbonate consists of heavy calcium carbonate powder.

[0066] (3-2) Types of inorganic substance powders other than calcium carbonate Examples of inorganic substance powders other than calcium carbonate include the following. Carbonates, sulfates, silicates, phosphates, or borates of metals (such as titanium, calcium, magnesium, aluminum, iron, zinc, etc.); Oxides of metals (such as titanium, calcium, magnesium, aluminum, iron, zinc, etc.); Hydrates of the above salts or oxides, etc.

[0067] Examples of inorganic substance powders other than calcium carbonate include titanium oxide, magnesium carbonate, zinc 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 sand, carbon black, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium sulfite, sodium sulfate, potassium titanate, bentonite, graphite, etc.

[0068] From the viewpoint that the effect of improving dispersibility is high and the effect according to the present invention can be more stably improved, as the inorganic substance powder other than calcium carbonate, components that do not contain any of lead, arsenic, alkali metals, and magnesium as constituent components are preferable. As such components, one or more of titanium oxide, zinc oxide, alumina, clay, talc, kaolin, aluminum hydroxide, aluminum silicate, calcium silicate, aluminum sulfate, calcium sulfate, barium sulfate, silica sand, carbon black, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium sulfite, bentonite, and graphite are preferable, and titanium oxide (TiO2) is more preferable.

[0069] The inorganic substance powder may be synthetic or derived from natural minerals.

[0070] (3-3) When containing a plurality of inorganic substance powders In the present invention, when two or more kinds are included as the inorganic substance powder, the combination ratio thereof is not particularly limited except that it mainly contains calcium carbonate powder, and can be appropriately set according to the effect to be obtained and the like.

[0071] In one aspect of the present invention, when containing two or more kinds of inorganic substance powders, the combination preferably includes a combination containing calcium carbonate and one or more other inorganic substance powders, more preferably a combination containing calcium carbonate and titanium oxide, and still more preferably a combination consisting of calcium carbonate and titanium oxide.

[0072] In one aspect of the present invention, when containing calcium carbonate and one or more other inorganic substance powders, the lower limit value of the content of the inorganic substance powder other than calcium carbonate is preferably 0.1% by mass or more, more preferably 1% by mass or more, and still more preferably 5% by mass or more based on the total inorganic substance powder. In one aspect of the present invention, when containing calcium carbonate and one or more other inorganic substance powders, the upper limit value of the content of the inorganic substance powder other than calcium carbonate is preferably 20% by mass or less, more preferably 10% by mass or less based on the total inorganic substance powder.

[0073] Whether calcium carbonate is contained in the inorganic substance powder in the resin composition and its content can be specified by firing the resin composition and performing ash analysis. The method of ash analysis can be applied mutatis mutandis to JIS K 7250-1:2006.

[0074] (3-4) Trace components in the inorganic substance powder As described above, the present invention uses, as the inorganic substance powder, those having a content of trace components within a predetermined range. By adjusting these components, even if the screwing part of the container is damaged, the mixing of impurities into the content of the container can be suppressed.

[0075] (3-4-1) Lead In one embodiment of the present invention, the lead content per 1 g of the inorganic substance powder is 20 μg or less. The lower the lead content, the easier it is to achieve the effects of the present invention. Per 1 g of the inorganic substance powder, it is preferably 10 μg or less, more preferably 3 μg or less. The lower limit of the lead content is not particularly limited, but per 1 g of the inorganic substance powder, it is preferably 0.0 μg or more.

[0076] (3-4-2) Alkali metals and magnesium In one embodiment of the present invention, when the inorganic substance powder is 100% by mass, the total amount of alkali metals and magnesium is 1.0% by mass or less. The lower the total amount of alkali metals and magnesium, the easier it is to achieve the effects of the present invention. When the inorganic substance powder is 100% by mass, it is preferably 0.8% by mass or less, more preferably 0.7% by mass or less. The lower limit of the total amount of alkali metals and magnesium is not particularly limited, but when the inorganic substance powder is 100% by mass, it is preferably 0.0% by mass or more.

[0077] (3-4-3) Other trace components The content of other trace components is not particularly limited, but the higher the purity of the inorganic substance powder, the easier it is to achieve the effects of the present invention.

[0078] For example, when the arsenic content per 1 g of the inorganic substance powder is preferably 3 μg or less, more preferably 2 μg or less, the safety of the container of the present invention is likely to be enhanced.

[0079] (3-4-4) Method for adjusting the content of trace components The method for adjusting the content of trace components is not particularly limited, and examples include the following. · Synthesis or collection of an inorganic substance powder that satisfies the requirements of the present invention. · Blending of an inorganic substance powder that does not satisfy any of the requirements of the present invention and an inorganic substance powder that satisfies the requirements of the present invention. ·A blend of an inorganic substance powder that satisfies only some of the requirements of the present invention (for example, only the lead content) and an inorganic substance powder that satisfies only another requirement of the present invention (for example, only the total amount of alkali metals and magnesium).

[0080] (3-4-5) Method for measuring trace components The content of trace components contained in the inorganic substance powder is specified by the following method described in the 9th Edition of the Japanese Pharmacopoeia of Food Additives (Ministry of Health, Labour and Welfare, Consumer Affairs Agency). The amount of trace components specified by this method does not necessarily accurately include the trace components contained in the inorganic substance powder other than calcium carbonate powder in the inorganic substance powder. However, since calcium carbonate powder is the main component in the inorganic substance powder, it sufficiently reflects the properties of the entire inorganic substance powder.

[0081] Regarding the purity test of calcium carbonate, etc., the 9th Edition of the Japanese Pharmacopoeia of Food Additives (Ministry of Health, Labour and Welfare, Consumer Affairs Agency) has the following description (pages 748 - 749). “(3) Lead Pb: 3 μg / g or less as Pb (2.0 g, Method 5, comparison solution: 6.0 mL of lead standard solution, flame method) Add 20 mL of hydrochloric acid (1→4) to this product, cover with a watch glass, etc., and gently boil for 15 minutes. After cooling, add 30 mL of water to obtain a sample solution. If the sample does not dissolve, evaporate to dryness, add 20 mL of hydrochloric acid (1→4) to the residue, cover with a watch glass, etc., and gently boil for 5 minutes. After cooling, add 30 mL of water to obtain a sample solution. However, change the amount of diammonium hydrogen citrate solution (1→2) shown in Method 5 to 50 mL, use 1 mL of bromothymol blue test solution as the indicator, and add aqueous ammonia until the yellow color of the solution changes to yellow - green.” “(4) Alkali metals and magnesium: 1.0% or less Weigh 1.0 g of this product, gradually add 30 mL of hydrochloric acid (1→10) to dissolve it, boil to expel carbon dioxide. After cooling, neutralize with ammonia test solution, add 60 mL of ammonium oxalate monohydrate solution (1→25), and heat on a water bath for 1 hour. After cooling, add water to make 100 mL, stir well, filter, measure 50 mL of the filtrate, add 0.5 mL of sulfuric acid, evaporate to dryness, and then heat strongly at 600 °C until it reaches a constant weight, and measure its mass.” “(6) Arsenic As: 3 μg / g or less as As (0.50 g, standard arsenic solution 3.0 mL, apparatus B) Weigh this product, moisten it with 1 mL of water, add 4 mL of hydrochloric acid (1→4), and dissolve it to obtain a test solution.”

[0082] Regarding the purity test, etc. of titanium oxide (titanium dioxide), the 9th Edition of the Japanese Pharmacopoeia of Food Additives (Ministry of Health, Labour and Welfare, Consumer Affairs Agency) has the following description (pages 808 - 809). “(3) Lead Pb: 10 μg / g or less as Pb (4.0 g, comparison solution, lead standard solution 4.0 mL, flame method) Add 50 mL of hydrochloric acid (1→20) to this product, cover it with a watch glass, etc., and boil for 20 minutes. Then, centrifuge to precipitate the insoluble matter. Filter the supernatant, wash the used container and the residue three times with 10 mL of hot water each time using the same filter paper, and filter again. Further, wash the used filter paper with 10 - 15 mL of hot water, and combine the washing liquid with the filtrate. After cooling, add water to make 100 mL to obtain a sample solution. Measure 10 mL of the sample solution, add hydrochloric acid in a volume of 1 / 4, and gently heat to evaporate to dryness. Add a small amount of nitric acid (1→100) to the residue and warm it. After cooling, add more nitric acid (1→100) to make exactly 10 mL to obtain a test solution. Separately, accurately measure a lead standard solution, add nitric acid (1→100) to make exactly 10 mL to obtain a comparison solution.” “(4) Arsenic As: 1 μg / g or less as As (10 g, standard color, arsenic standard solution 3.0 mL, apparatus B) Weigh this product, put it into a 250 mL beaker, add 50 mL of hydrochloric acid (1→20), cover it with a watch glass, etc., heat until boiling, and further boil gently for 15 minutes. Then, centrifuge to precipitate the insoluble matter. Filter the supernatant, wash the used beaker and the residue three times with 10 mL of hot water each time using the same filter paper, and filter again. Further, wash the used filter paper with 10 - 15 mL of hot water, and combine the washing liquid with the filtrate. After cooling, add water to make 100 mL to obtain a sample solution. Measure 15 mL of the sample solution to obtain a test solution.”

[0083] (3 - 5) Other conditions for inorganic substance powders The inorganic substance powder can be in any form as long as it satisfies the above conditions for trace components.

[0084] The average particle size of the inorganic substance powder can be appropriately set according to the moldability to be achieved and the like. However, from the viewpoint of easily realizing stable dispersibility and easily exhibiting homogeneous mechanical properties throughout the resin molded product, the average particle size by the air permeability method according to JIS M-8511:2014 in the inorganic substance powder is preferably 0.7 μm or more and 6.0 μm or less, more preferably 1.0 μm or more and 5.5 μm or less. The average particle size of the inorganic substance powder only needs to satisfy the above requirements for the entire inorganic substance powder.

[0085] In order to enhance the dispersibility and reactivity of the inorganic substance powder, the surface of the inorganic substance powder may or may not be surface-modified in advance according to a conventional method. Examples of the surface modification method include physical treatment methods (such as plasma treatment) and chemical treatment methods (methods using coupling agents or surfactants).

[0086] The shape of the inorganic substance powder is not particularly limited and may be any of particulate (spherical, irregular, etc.), flaky, granular, fibrous, etc.

[0087] (3-6) Blending amount of inorganic substance powder In one aspect of the present invention, the content of the inorganic substance powder is not particularly limited as long as the content of the inorganic substance powder in the entire container is more than 50.0% by mass and 80.0% by mass or less.

[0088] The lower limit of the content of the inorganic substance powder is more than 50.0% by mass, preferably 52.0% by mass or more, more preferably 54.0% by mass or more, and still more preferably 56.0% by mass or more with respect to the entire container from the viewpoint of blending a sufficient amount of the inorganic substance powder and solving the problems peculiar to the present invention.

[0089] From the viewpoint of moldability and the like, the upper limit of the content of the inorganic substance powder is 80.0% by mass or less, preferably 78.0% by mass or less, more preferably 76.0% by mass or less, and still more preferably 74.0% by mass or less with respect to the entire container.

[0090] From the viewpoint of blending a sufficient amount of the inorganic substance powder and solving the problems peculiar to the present invention, the lower limit of the content of the inorganic substance powder is more than 50.0% by mass, preferably 52.0% by mass or more, more preferably 54.0% by mass or more, and still more preferably 56.0% by mass or more with respect to the screwed portion of the container. It is preferable that either the container body or the screwed portion of the lid in the container satisfies the above requirements, and it is more preferable that both satisfy the requirements.

[0091] From the viewpoint of moldability and the like, the upper limit of the content of the inorganic substance powder is 80.0% by mass or less, preferably 78.0% by mass or less, more preferably 76.0% by mass or less, and still more preferably 74.0% by mass or less with respect to the screwed portion of the container. It is preferable that either the container body or the screwed portion of the lid in the container satisfies the above requirements, and it is more preferable that both satisfy the requirements.

[0092] From the viewpoint of easily solving the problems peculiar to the present invention, the content of calcium carbonate in the inorganic substance powder is preferably 70.0% by mass or more, more preferably 80.0% by mass or more, and most preferably 100.0% by mass with respect to the entire inorganic substance powder.

[0093] Whether calcium carbonate is contained in the inorganic substance powder and its content can be specified by firing the resin molded product and performing ash analysis.

[0094] (4) Other components In the container, other components other than the inorganic substance powder and the thermoplastic resin may or may not be blended within a range that does not inhibit the effects of the present invention.

[0095] As the other components, any components that can be usually blended in the resin molded product can be adopted. Examples of such components include colorants, lubricants, dispersants, antistatic agents, antioxidants, heat stabilizers, ultraviolet absorbers, and the like. The types and amounts of these components can be appropriately set according to the desired effects and the like.

[0096] In a preferred embodiment of the present invention, the container includes those consisting only of a thermoplastic resin and an inorganic substance powder.

[0097] (5) Ratio of thermoplastic resin to inorganic substance powder In the container, the mass ratio of the thermoplastic resin to the inorganic substance powder (thermoplastic resin: inorganic substance powder) is preferably less than 50: more than 50 to 20:80, more preferably 45:55 to 20:80, and still more preferably 40:60 to 25:75.

[0098] (6) Method for manufacturing the container The method for manufacturing the container is not particularly limited, and any method known as a method for manufacturing a resin container or the like can be adopted.

[0099] For example, the constituent components of the container may be pelletized (resin composition) and then formed into the container, or the constituent components of the container may be melt-kneaded and directly formed into the container.

[0100] Examples of the forming method of the container include injection molding and compression molding.

[0101] An ink-receiving layer may be provided on the surface of the container as needed. In the present invention, the "ink-receiving layer" includes any configuration adopted in the field of printing paper, and includes, for example, a coating layer for fixing the ink applied by printing without bleeding. The printing method is not particularly limited, and examples include inkjet printing. The type of the coating layer is not particularly limited, and includes a swelling type, a matte type, and the like. The ink-receiving layer can be provided by applying and drying a coating liquid for the ink-receiving layer on the surface of the single-layer portion using a coating device (such as a gravure coater or a bar coater).

[0102] (7) Use of the container The container can be used for the purpose of containing any substance.

[0103] The container can be, for example, a container for pharmaceuticals, a container for cosmetics, etc.

[0104] The form of the substance contained in the container is not particularly limited, and it can be a substance such as liquid, solid, gel, cream, etc.

Example

[0105] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0106] <Fabrication and evaluation of the container> A substantially cylindrical wide-mouth container (jar container) was fabricated by the following method, and the presence or absence and degree of lead contamination were evaluated when a local load was applied to its screwing portion (thread).

[0107] (1) Preparation of materials The materials for the container were prepared as follows.

[0108] (1-1) Inorganic substance powder The following were prepared as inorganic substance powders. · Calcium carbonate particles (heavy calcium carbonate particles): The average particle diameter by the air permeability method according to JIS M-8511:2014 for these calcium carbonate particles was 2.0 μm. · Titanium oxide particles: The average particle diameter by the air permeability method according to JIS M-8511:2014 for these titanium oxide particles was 0.6 μm.

[0109] Only calcium carbonate particles were used to prepare the following "inorganic powder 1" to "inorganic powder 3". First, three types with different trace component contents (calcium carbonate purity) recovered from different mines were blended in various ratios to prepare inorganic powders 1 to 3 (Table 1). The trace component content in the calcium carbonate particles was measured in accordance with the section on "Calcium Carbonate" (pages 748 - 749) of the 9th Edition of the Japanese Pharmacopoeia (Ministry of Health, Labour and Welfare, Consumer Affairs Agency). This pharmacopoeia stipulates the measurement methods for trace components (lead, alkali metals and magnesium, hydrochloric acid-insoluble substances, and free alkali, etc.) contained in calcium carbonate.

[0110] Furthermore, the following "inorganic powder 4" was prepared using calcium carbonate particles and titanium oxide particles. The purchased titanium oxide particles and calcium carbonate particles were blended at a mass ratio of titanium oxide particles:calcium carbonate particles = 10:90 to prepare "inorganic powder 4". "Inorganic powder 1" was used as the calcium carbonate particles. The trace component content in the titanium oxide particles was measured in advance in accordance with the section on "Calcium Carbonate" (pages 748 - 749) of the 9th Edition of the Japanese Pharmacopoeia (Ministry of Health, Labour and Welfare, Consumer Affairs Agency). As a result, the trace components contained in titanium dioxide were all below the detection limit. Therefore, the amount of trace components contained in the inorganic substance powder used in this example is consistent with the amount of trace components contained in the calcium carbonate powder.

[0111] In Table 1, each trace component content means the following. · Lead: The content of lead per gram of inorganic substance powder (unit: μg) · Alkali metals: The total amount of alkali metals and magnesium (unit: mass%) when the inorganic substance powder is 100 mass% · Arsenic: The content of arsenic per gram of inorganic substance powder (unit: μg)

[0112]

Table 1

[0113] (1 - 2) Thermoplastic resin One of the following thermoplastic resins was used. Polypropylene resin (PP): Polypropylene block copolymer (melting point 160 °C) Polyethylene resin (PE): Blend of HDPE and LLDPE (HDPE:LLDPE (mass ratio) = 70:30) In addition, the MFR (190 °C, 2.16 kg) of the above HDPE according to JIS K 6922-1:2018 (ISO1133) is 7.5 g / 10 min. The MFR (190 °C, 2.16 kg) of the above LLDPE according to JIS K 6922-1:2018 (ISO1133) is 0.8 g / 10 min.

[0114] (2) Production of the container The thermoplastic resin and the inorganic substance powder were mixed at the ratios shown in Tables 2 to 5 to obtain pellets. Next, using the obtained pellets, a container (container body and lid) was produced by injection molding. A transparent gel was put into the obtained container up to about 1 / 3 of the height of the container body.

[0115] The substantially cylindrical wide-mouth container produced in this example consists of a container body having an opening and a lid for closing the opening. Threads (screw engagement parts) are formed on the container body and the lid, respectively, and they are designed to be screwed together. The dimensions of each part of the container are as follows.

[0116] (2-1) Dimensions of the container body Barrel diameter: 90 mm Height: 85 mm Thread diameter: 63 mm Height of the thread: 1.5 mm Neck length (part where the thread is provided): 20 mm

[0117] (2-2) Dimensions of the lid Outer diameter of the lid: 70 mm Height: 25 mm Height of the thread: 1.5 mm

[0118] (3) Strength Evaluation - 1 For each container having the composition shown in Tables 2 and 3, in accordance with JIS Z 0202:2017, a drop impact test was conducted on the entire container and evaluated according to the following criteria. The results are shown in the "Drop Test" items of Tables 2 and 3.

[0119] [Evaluation Criteria] None: No damage to the container was observed. Minor: Slight damage (such as cracks) to the container was observed. Major: Clear damage (such as cracks and chips) to the container was observed.

[0120] As shown in Tables 2 and 3, the strength (such as impact resistance) of the entire container was higher as the content of the inorganic substance powder was higher. In this example, the results using "Inorganic Powder 1" were shown. However, even when "Inorganic Powder 2" or "Inorganic Powder 3" was used instead of "Inorganic Powder 1", the same tendency as above was observed.

[0121] (4) Strength Evaluation - 2 First, the lid of each container having the composition shown in Tables 2 and 3 was screwed together to about half the height of the neck of the container body, leaving the lid in a half-closed state (that is, not fully closed). In this state, a load was applied from directly above the lid towards the container body. This test was carried out with reference to the tensile test (JIS K 7113:1995, etc.).

[0122] When the lid of the container under load reached the bottommost part of the neck of the container body, the lid of the container was removed, and the damaged state of the thread was visually observed and evaluated according to the following criteria. The results are shown in the "Damage" items of Tables 2 and 3.

[0123] [Evaluation Criteria] None: No damage to the thread was observed. Minor: Slight damage (such as cracks) to the thread was observed. Major: Clear damage (such as cracks and chips) to the thread was observed.

[0124] As shown in Tables 2 and 3, the higher the content of the inorganic substance powder (especially when it exceeds 50.0% by mass), the more clearly the thread damage due to the load on the lid was observed. As shown in "Strength Evaluation - 1", although the strength of the whole container (such as impact resistance) was higher as the content of the inorganic substance powder was higher, the poor resistance to such local loads was a very unexpected finding.

[0125] (5) Evaluation of the incorporation of trace components Similar to the above "Strength Evaluation - 2", the lid of each container was screwed to about half of the neck length of the container body, and the lid was in a half-closed state. A load was applied from directly above the lid towards the container body until it reached the bottommost part of the neck length of the container body. Next, the lid of the container was removed, all the gel in the container body was recovered, and in accordance with the section on "Calcium Carbonate" in the 9th Edition of the Japanese Pharmacopoeia (Ministry of Health, Labour and Welfare, Consumer Affairs Agency) (pages 748 - 749), the total amount of trace components (such as lead) in the gel was confirmed and evaluated according to the following criteria. The results are shown in the section on "Incorporation of Trace Components" in Tables 4 and 5.

[0126] [Evaluation Criteria] None: No incorporation of trace components was observed at all. Low: The lead content per gram of gel was 0.01 μg or less. High: The lead content per gram of gel was more than 0.01 μg.

[0127] [Table 2]

[0128] [Table 3]

[0129] [Table 4]

[0130] [Table 5]

[0131] First, as shown in the "Reference Example", it was confirmed that the higher the content of the inorganic substance powder, the easier it is to increase the drop impact resistance. However, the higher the content of the inorganic substance powder, the lower the resistance to local loads. Conventionally, it has been known that blending inorganic substance powder enhances the mechanical properties of resin products, but the finding that it can be inferior to such local loads is extremely unexpected.

[0132] From the above results, the present inventors confirmed that for containers with a high content of inorganic substance powder, particularly containers with a content of more than 50.0% by mass and 80.0% by mass or less, although the mechanical properties of the whole container are good, thread breakage is likely to occur.

[0133] As shown in the "Examples", it was specified that even if thread breakage occurs in a container with a high filling of inorganic substance powder, by satisfying the requirements of the present invention, mixing of trace components can be suppressed.

[0134] On the other hand, in the "Comparative Examples" that do not satisfy the requirements of the present invention, many impurities were mixed into the contents of the container. Also, in a container with a low content of inorganic substance powder (for example, Comparative Example 3-2), even though an inorganic substance powder with a high content of trace components was used, since the content of the inorganic substance powder was low, thread breakage did not occur in the first place, and it should be noted that there is no problem in the present invention.

[0135] Even when using other inorganic substance powders (in this example, titanium oxide) together with heavy calcium carbonate powder as the inorganic substance powder, results of the same tendency as above were obtained. Also, in the same manner as "Inorganic Powder 4", when blending titanium oxide particles:calcium carbonate particles (mass ratio) = 10:90 for "Inorganic Powder 2" or "Inorganic Powder 3", results of the same tendency as when using only "Inorganic Powder 2" or "Inorganic Powder 3" were obtained respectively. From this, it was found that if an inorganic substance powder is used so as to satisfy the requirements of the present invention, the type of the inorganic substance powder itself does not significantly affect the results.

[0136] In this example, heavy calcium carbonate was employed as the inorganic substance powder, but the same tendency as above was also observed for other inorganic substance powders (light calcium carbonate, talc, etc.).

Claims

1. A container comprising: The container comprises a container body having an opening and a lid for closing the opening, the opening includes a first threaded portion; the lid includes a second screw portion that is screwed into the first screw portion, the first screw-type portion and the second screw-type portion contain an inorganic powder and a thermoplastic resin; The content of the inorganic powder is more than 50.0% by mass and not more than 80.0% by mass with respect to the entire container, The container, wherein the inorganic substance powder mainly contains calcium carbonate and satisfies all of the following requirements: (Requirement 1) The lead content per gram of the inorganic substance powder is 20 μg or less. (Requirement 2) When the inorganic substance powder is taken as 100% by mass, the total amount of alkali metal and magnesium is 1.0% by mass or less.

2. The resin composition according to claim 1 , wherein the content of the calcium carbonate is 80 mass % or more based on the inorganic substance powder.

3. 10. The container of claim 1, wherein the calcium carbonate comprises ground calcium carbonate.

4. 2. The container of claim 1, wherein the inorganic powder further meets the following requirements: (Requirement 3) The arsenic content per gram of the inorganic substance powder is 3 μg or less.

5. The container according to claim 3, wherein the heavy calcium carbonate contains heavy calcium carbonate having an average particle size of 0.7 μm or more and 6.0 μm or less as measured by an air permeability method in accordance with JIS M-8511:2014.

6. The container according to claim 1 , wherein the thermoplastic resin comprises a polypropylene-based resin and / or a polyethylene-based resin.

7. The container according to claim 6, wherein the polyethylene-based resin comprises high density polyethylene and / or linear low density polyethylene.

8. The container according to claim 6 , wherein the polypropylene-based resin comprises a polypropylene homopolymer and / or a polypropylene block polymer.

9. The container according to claim 1 , wherein the container is obtained by injection molding or compression molding.

10. The container of claim 1 , wherein the container is a pharmaceutical container.

11. The container of claim 1 , wherein the container is a cosmetic container.

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