Olefin resin container

Abstract

The present invention provides an olefin resin container which has high mechanical strength and low production cost, while enabling the achievement of a large capacity, and which also has excellent chemical resistance and low dissolvability, thereby enabling easy storage of the content and easy transportation management. According to the present invention, an outer layer that is formed of an olefin resin and an additive is superposed on the outer side of an inner layer that is formed only of an olefin resin. An identification information display part on which identification information on the material of the container, the production history of the container and the material of the content of the container can be printed and updated, or alternatively, an identification information display part to and from which a sheet that is printed with identification information on the material of the container, the production history of the container and the material of the content of the container can be adhered and separated is arranged on the wall surface of the container in a position where the identification information is readable from the outside.

Description

[Technical field]

[0001] The present invention relates to an olefin-based resin container that has high mechanical strength, can be made large in capacity, can be manufactured at low cost, is resistant to chemicals and has low elution properties, and is easy to manage for storage and transportation of the contents.The present invention further relates to an olefin-based resin container that contains a biomass-derived olefin-based resin, is environmentally friendly, has excellent ESCR resistance (environmental stress crack resistance), has high mechanical strength, has excellent self-supporting properties, is resistant to chemicals and has low elution properties, and is easy to manage for storage and transportation of the contents. [Background technology]

[0002] 2. Description of the Related Art Conventionally, containers for filling beverages and edible liquids such as water, juice, soy sauce, and edible oil, chemicals such as kerosene, acetic acid, hydrochloric acid, and nitric acid, chemicals that are intermediates for special industrial products, and abrasives, cleaning solutions, developing solutions, resist agents, and the like used in the manufacturing process of electronic materials including semiconductors have generally been made of blow-molded olefin-based resins such as polyethylene resin and polypropylene resin.

[0003] Examples of such containers include "containers for storing high-purity solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, acetone, ethyl acetate, toluene, dimethylformamide, ethylene glycol acetate, methoxypropyl acetate, or butyl cellosorb, and at least the inner surface of the container has a density of 0.940 to 0.970 g / cm. 3 The resin is made of polyethylene or ethylene-α-olefin copolymer, and the contents of neutralizer, antioxidant and light stabilizer in the resin as determined by liquid chromatography are each 0.01% by weight or less based on the total weight of the resin, and the weight-average molecular weight of the resin as measured by gel permeation chromatography is 12 to 26 × 10 4 The molecular weight of the resin is 1×10 3"A container for high-purity solvents, characterized in that the following polymer is less than 2.5% by weight based on the total weight of the resin." (Patent Document 1), and "A container for high-purity solvents, characterized in that the following polymer is less than 2.5% by weight based on the total weight of the resin: 4 So, 1×10 3 Molecular weight of less than 5% by weight, density 0.940-0.970g / cm 3 a resin of polyethylene or ethylene-α-olefin copolymer, a neutralizing agent, an antioxidant, and a light-resistant stabilizer each of which is 0.01% by weight or less as determined by liquid chromatography, 0.01% by weight to 5% by weight of at least one light-shielding pigment selected from inorganic pigments such as titanium oxide, carbon black, and red iron oxide, phthalocyanine-based, quinacridone-based, and azo-based organic pigments, and a polymer having a number-average molecular weight of 2×10 3 "(Patent Document 2) has proposed a light-shielding container for high-purity chemicals molded from a resin composition containing less than 5% by weight of the above-mentioned olefin polymer dispersant." However, the containers described in Patent Documents 1 and 2 above have the disadvantages that they are difficult to mold, have high manufacturing costs, have low mechanical strength, are easily broken, and cannot have a large capacity.

[0004] Generally, containers filled with the above-mentioned contents are stored and transported, and after use, the empty containers are sent back to the manufacturer for reuse. In this case, identification information such as the type and amount of the contents, production date and time, production lot number, and shipping date and time are important, so various methods have been proposed to make this management easier.

[0005] For example, an identification information management system has been proposed, which includes: "a storage unit that stores content data including material information indicating the content of a container to which a mark has been applied using a device that applies a mark capable of obtaining identification information by reading the mark, in association with the identification information; an update unit that updates the content data associated in the storage unit with the identification information of the mark read from the mark applied to the container by the reader based on information including material information on a material that has been put into a specific container out of a plurality of materials according to a work process; a reception unit that receives information corresponding to an end input indicating that a work process on the marked container has ended; and when the reception unit determines that the information corresponding to the end input received is information indicating that the material in the marked container has been used and is empty, the content data associated with the identification information of the mark is deleted from the storage unit; and when the determination unit determines that the information corresponding to the end input received by the reception unit is information indicating that a material has been put into the marked container, the content data is updated to include material information on the material in the container in association with the identification information of the mark applied to the container into which the material has been put." (Patent Document 3). However, according to the system described in Patent Document 3, in order to identify the ingredients in the container, it is necessary to print and update the identification information of the ingredients in the container in a position on the container wall that can be read from the outside.

[0006] Meanwhile, in recent years, with the growing demand for the creation of a recycling-oriented society, research has been conducted into the use of biomass-derived olefin resins, polyesters, polylactic acid and other biodegradable resins, which are carbon-neutral renewable synthetic resins, instead of petroleum-derived olefin resins produced from fossil fuels.

[0007] For example, a synthetic resin container has been proposed that is a laminated synthetic resin container having an intermediate layer between an inner layer and an outer layer, the inner and outer layers being made of an olefin resin, the intermediate layer being made of a component mainly composed of biomass plastic, the amount of resin used in the inner and outer layers being 20 to 75 mass % of the total resin amount, the amount of resin used in the intermediate layer being 25 to 80 mass % of the total resin amount, the intermediate layer being made of at least one of polylactic acid, starch resin, PHA resin, aliphatic polyester mainly composed of biomass, and biodegradable plastic derived from biomass, and containing a modifier that is a flexible resin that accounts for 15 mass % or less of the total resin amount forming the intermediate layer. (Patent Document 4)

[0008] However, the above biomass-derived resins (biomass-derived olefin-based resins, polyesters, polylactic acid, and other biodegradable resins) have poorer physical properties than petroleum-derived olefin-based resins, and in particular, the melt-molded molded bodies have the disadvantage of being significantly inferior in physical properties such as mechanical strength. In addition, the above biomass-derived resins have low melt tensions, making them unable to be blow-molded, or even if blow-molding can be performed, they have low mechanical strength and cannot be used as containers. In particular, after filling a container with a liquid filling, the shape of the container may change or cracks may occur in the corners of the container (poor ESCR resistance) due to changes in the external environment or over time during storage or transportation. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 2749513 specification [Patent Document 2] Patent No. 2805723 specification [Patent Document 3] JP 2020-181482 A [Patent Document 4] Patent No. 5191776 specification Summary of the Invention [Problem to be solved by the invention]

[0010] In view of the above problems, the object of the present invention is to provide an olefin-based resin container that has high mechanical strength, can be made large in capacity, can be manufactured at low cost, has excellent chemical resistance, low elution, and is easy to manage for storage and transportation of the contents. Another object of the present invention is to provide an olefin-based resin container that is environmentally friendly, has high mechanical strength, excellent chemical resistance, low elution, excellent ESCR resistance, and is easy to manage for storage and transportation of the contents. [Means for solving the problem]

[0011] In order to achieve the above-mentioned object, the first invention of the present application is an olefin-based resin container in which an outer layer consisting of an olefin-based resin and additives is laminated on the outside of an inner layer consisting only of an olefin-based resin, and is characterized in that an identification information display unit on which identification information of the container material, the container's manufacturing history, and the materials inside the container can be printed and updated, or an identification information display unit on which a sheet on which identification information of the container material, the container's manufacturing history, and the materials inside the container can be attached and peeled off, is provided in a position readable from the outside of the container wall.

[0012] The second invention of the present application is an olefin-based resin container having a first layer made of a petroleum-derived olefin-based resin and a second layer made of an olefin-based resin composition consisting of 100 parts by weight of petroleum-derived olefin-based resin and 35 to 200 parts by weight of a biomass-derived olefin-based resin, the first layer being the inner layer and the second layer being the outer layer, characterized in that an identification information display unit on which identifying information of the container material, the container's manufacturing history, and the materials contained in the container can be printed and updated, or an identification information display unit on which a sheet on which identifying information of the container material, the container's manufacturing history, and the materials contained in the container can be attached and peeled off, is provided in a position readable from the outside of the container wall.

[0013] The third invention of the present application is an olefin-based resin container characterized in that, in the first invention of the present application, the additive is one or more of a heat stabilizer, a heat resistance improver, a light stabilizer, an ultraviolet absorber, an antioxidant, an impact modifier, an anti-fogging agent, an antistatic agent, a flame retardant, or a pigment.

[0014] The fourth invention of the present application is an olefin-based resin container characterized in that, in the second invention of the present application, a third layer made of a petroleum-derived olefin-based resin is laminated on the outside of the second layer.

[0015] A fifth invention of the present application is an olefin-based resin container according to the second or fourth invention of the present application, characterized in that the biomass ratio of the container measured in accordance with ASTM D6866 is 1 to 60%.

[0016] A sixth invention of the present application is an olefin-based resin container according to the second or fourth invention of the present application, characterized in that the petroleum-derived olefin-based resin and the biomass-derived olefin-based resin are high-density polyethylene.

[0017] The seventh invention of the present application is an olefin-based resin container according to the first or second invention of the present application, characterized in that the identification information is a barcode, a two-dimensional code, a QR code (registered trademark), or an RFID tag. Effect of the Invention

[0018] The olefin-based resin container of the first invention of the present application has the effects of high mechanical strength, large capacity, low manufacturing cost, excellent chemical resistance, low elution, and easy management of storage and transportation of the filled materials. The olefin-based resin container of the second invention of the present application has the effects of being environmentally friendly, high mechanical strength, excellent chemical resistance, low elution, excellent ESCR resistance, and easy management of storage and transportation of the filled materials. The third invention of the present application has the effect of improving physical properties such as mechanical strength. The fourth invention of the present application has the effect of further increasing mechanical strength. The fifth invention of the present application has the effect of being environmentally friendly. The sixth invention of the present application has the effect of further increasing mechanical strength. The seventh invention of the present application has the effect of easy management of storage and transportation of the filled materials. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a plan view of a bottom plate of one embodiment of an olefin-based resin container. [Diagram 2] 2(a) is a cross-sectional view taken along line AA in FIG. 1, and FIG. 2(b) is a cross-sectional view taken along line BB in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The olefin-based resin container of the first invention of this application is an olefin-based resin container in which an outer layer consisting of an olefin-based resin and additives is laminated on the outside of an inner layer consisting only of an olefin-based resin, and is characterized in that an identification information display unit on which identification information of the container material, the container's manufacturing history, and the materials contained in the container can be printed and updated, or an identification information display unit on which a sheet on which identification information of the container material, the container's manufacturing history, and the materials contained in the container can be attached and peeled off, is provided in a position readable from the outside of the container wall.

[0021] Examples of the olefin resin include high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, linear low-density polyethylene resin, polypropylene resin, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-vinyl acetate copolymer, and the like. Two or more types of olefin resins may be mixed depending on the desired physical properties. When an olefin resin container having excellent flexibility is to be obtained, low-density polyethylene resin and linear low-density polyethylene resin are preferred, and when an olefin resin container having high mechanical strength is to be obtained, high-density polyethylene resin and polypropylene resin are preferred.

[0022] The inner layer of the olefin resin container of the first invention of the present application is a resin layer consisting of only an olefin resin. The inner layer is a layer that comes into direct contact with the contents when the container is filled with beverages such as water, juice, soy sauce, and edible oil, chemicals such as kerosene, acetic acid, hydrochloric acid, and nitric acid, and medicines that are intermediates of special industrial products, and if the olefin resin forming the inner layer contains additives, the additives may dissolve into the contents or fall off, contaminating the contents. However, since the inner layer of the olefin resin container of the first invention of the present application is composed of only an olefin resin, it does not have the above-mentioned disadvantages.

[0023] The olefin resin container of the first invention of the present application is filled with various liquids and stored and transported, and various functions and effects are required depending on the liquid to be filled. Therefore, an outer layer made of an olefin resin and an additive is laminated on the outside of the inner layer made of only an olefin resin of the olefin resin container of the first invention of the present application. For example, it is preferable to add an inorganic filler to the olefin resin of the outer layer in order to make the container slippery and easy to stack and handle, and it is preferable to add an organic pigment or an inorganic pigment to the olefin resin of the outer layer in order to give the container light-shielding properties and make the identification information printed on the wall surface easy to read. Examples of the inorganic filler include commonly used substances such as talc, mica, calcium carbonate, magnesium hydroxide, alumina, zinc oxide, magnesium oxide, aluminum hydroxide, silica alumina, titanium oxide, calcium oxide, calcium silicate, basic magnesium carbonate, carbon fiber, and carbon black. Examples of the organic pigment include commonly used substances such as alkali blue, lysol red, carmine 6B, disazo yellow, phthalocyanine blue, quinacridone red, and isoindoline yellow. Examples of the inorganic pigments include commonly used substances such as red earth, yellow earth, green earth, malachite, chalk, graphite, iron blue, zinc oxide, cobalt blue, emerald green, viridian, and titanium white.

[0024] Other additives to be added to the olefin-based resin of the outer layer include heat stabilizers, heat resistance improvers, light stabilizers, ultraviolet absorbers, antioxidants, impact modifiers, anti-fogging agents, antistatic agents, flame retardants, etc., which have been commonly used in the past when molding olefin-based resins.

[0025] The amounts of the inorganic filler, organic pigment, and inorganic pigment to be added are not particularly limited, but if the amount is increased, the mechanical strength of the resulting container, such as tensile strength, tensile modulus, and elongation, decreases, so it is preferably 5 parts by weight or less per 100 parts by weight of the olefin resin. The amount of other additives to be added is also not particularly limited, but it is preferably 2 parts by weight or less per 100 parts by weight of the olefin resin.

[0026] The olefin-based resin container of the first invention of the present application can be obtained by blow molding the above-mentioned olefin-based resin. Blow molding is a method of molding a resin into the shape of a mold by putting heated resin into a mold and blowing air into the resin from inside. For example, a resin consisting of only an olefin-based resin and a resin composition consisting of an olefin-based resin and an additive are melted to be in a molten state, and co-extruded into a mold so that a resin layer consisting of only an olefin-based resin is the inner layer and a resin composition layer consisting of an olefin-based resin and an additive is the outer layer to obtain a cylindrical parison, and then the mold is closed to sandwich the cylindrical parison, compressed air is blown into the parison with a blow pin to expand the parison, and the mold is closed so as to roll up the end of the parison to form the bottom part, and the expanded parison is pressed against a cooled mold to solidify, and the mold is opened after cooling for a certain period of time to obtain a molded product, thereby obtaining the olefin-based resin container of the first invention of the present application.

[0027] The olefin-based resin container of the first invention of the present application may have an inner layer made of only an olefin-based resin, an outer layer made of a resin composition made of an olefin-based resin and an additive, and an intermediate layer made of recycled materials, crushed materials of defective products generated during molding, etc., between the inner layer and the outer layer. The recycled materials and crushed materials of defective products generated during molding can be mixed with virgin raw materials, etc., or used as they are for the outer layer.

[0028] The second invention of the present application is an olefin-based resin container having a first layer made of a petroleum-derived olefin-based resin and a second layer made of an olefin-based resin composition consisting of 100 parts by weight of petroleum-derived olefin-based resin and 35 to 200 parts by weight of a biomass-derived olefin-based resin, the first layer being the inner layer and the second layer being the outer layer, characterized in that an identification information display unit on which identifying information of the container material, the container's manufacturing history, and the materials contained in the container can be printed and updated, or an identification information display unit on which a sheet on which identifying information of the container material, the container's manufacturing history, and the materials contained in the container can be attached and peeled off, is provided in a position readable from the outside of the container wall.

[0029] The petroleum-derived olefin resin is a polymer polymerized using olefin monomers such as ethylene monomers and propylene monomers refined from petroleum as the main raw material, and examples thereof include polyethylene homopolymers such as high-density polyethylene resins, medium-density polyethylene resins, and low-density polyethylene resins, copolymers of ethylene as the main component and α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, and 1-heptene, polypropylene homopolymers such as homopolypropylene resins and random polypropylene resins, copolymers of propylene as the main component and α-olefins such as ethylene, 1-butene, 1-hexene, 1-pentene, and 1-heptene, and the like. High-density polyethylene resins, medium-density polyethylene resins, homopolyethylene resins, and random polypropylene resins, which have high mechanical strength and excellent self-supporting properties, are preferred, and high-density polyethylene resins are more preferred. Moreover, these olefin resins may be used alone, or two or more types of olefin resins may be used in combination.

[0030] The biomass-derived olefin resins are polymers obtained by polymerizing olefins such as ethylene and propane that are chemically reacted and refined using ethanol or propanol produced from renewable natural raw materials (e.g., corn, sugarcane, beets, manioc, etc.).

[0031] Examples of the biomass-derived olefin resin include polyethylene homopolymers such as high-density polyethylene resin, medium-density polyethylene resin, and low-density polyethylene resin; copolymers of ethylene with α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, and 1-heptene; polypropylene homopolymers such as homopolypropylene resin and random polypropylene resin; copolymers of propylene with α-olefins such as ethylene, 1-butene, 1-hexene, 1-pentene, and 1-heptene; and the like. High-density polyethylene resin, medium-density polyethylene resin, homopolyethylene resin, and random polypropylene resin, which have high mechanical strength and excellent self-supporting properties, are preferred, and high-density polyethylene resin is more preferred. These olefin resins may be used alone, or two or more types of olefin resins may be used in combination.

[0032] The olefin-based resin container of the second invention of the present application can be obtained by blow molding the petroleum-derived olefin-based resin and the biomass-derived olefin-based resin. Blow molding is a method of molding a resin into the shape of a mold by putting heated resin into a mold and blowing air into the resin from inside. For example, a resin consisting of only a petroleum-derived olefin-based resin and a resin consisting of a petroleum-derived olefin-based resin and a biomass-derived olefin-based resin are melted to be in a molten state, and co-extruded into a mold so that a resin layer consisting of only a petroleum-derived olefin-based resin is the inner layer and a resin consisting of a petroleum-derived olefin-based resin and a biomass-derived olefin-based resin is the outer layer to obtain a cylindrical parison, and then the mold is closed to sandwich the cylindrical parison, compressed air is blown into the parison with a blow pin to expand the parison, and the mold is closed so as to roll up the end of the parison to form the bottom part, and the expanded parison is pressed against a cooled mold to solidify, and the mold is opened after cooling for a certain period of time to obtain a molded product, thereby obtaining the olefin-based resin container of the second invention of the present application.

[0033] The first layer in the olefin-based resin container of the second invention of the present application is made of a petroleum-derived olefin-based resin, and since it is the inner layer of the container, it is preferable that additives such as polymerization initiators and antioxidants are not contained as much as possible. Furthermore, if the first layer contains a biomass-derived olefin-based resin, when a filler such as a chemical is placed in the container, the filler will come into contact with the first layer, deteriorating the chemical resistance and elution resistance and decreasing the ESCR resistance, so it is preferable that the biomass-derived olefin-based resin is not contained in the first layer. If the first layer contains a biomass-derived olefin-based resin, it is preferable that the amount is 5% by weight or less.

[0034] The second layer in the olefin-based resin container of the second invention of this application consists of 100 parts by weight of petroleum-derived olefin-based resin and 35 to 200 parts by weight of biomass-derived olefin-based resin, and is the outer layer of the container. Therefore, even if the container contains a filling such as a chemical, the filling does not come into contact with the second layer. Therefore, even if the container contains a biomass-derived olefin-based resin, the chemical resistance and elution properties are not deteriorated, and the ESCR resistance is not reduced.

[0035] If the content of the biomass-derived olefin-based resin in the second layer is low, the friendliness to the environment is reduced, and conversely, if the content of the biomass-derived olefin-based resin in the second layer is high, moldability such as injection moldability and blow moldability is reduced, making it difficult to manufacture the container. Therefore, the second layer is composed of 100 parts by weight of the petroleum-derived olefin-based resin and 35 to 200 parts by weight of the biomass-derived olefin-based resin. Preferably, the second layer is composed of 100 parts by weight of the petroleum-derived olefin-based resin and 35 to 150 parts by weight of the biomass-derived olefin-based resin.

[0036] The petroleum-derived olefin resin in the second layer may be a recovered and crushed product of a petroleum-derived olefin resin molded body, or a recovered and crushed product of a molded body made of a petroleum-derived olefin resin and a biomass-derived olefin resin, for the purpose of cost reduction, waste reduction (reuse of waste), etc., or may include a recovered and crushed product of a petroleum-derived olefin resin molded body, a recovered and crushed product of a molded body made of a petroleum-derived olefin resin and a biomass-derived olefin resin, or a recovered and crushed product of a molded body made of a biomass-derived olefin resin. Since the recovered and crushed product may have reduced physical properties such as mechanical strength due to thermal history, the recovered and crushed product is preferably 300 parts by weight or less, more preferably 250 parts by weight or less, relative to 100 parts by weight of the petroleum-derived olefin resin in the second layer.

[0037] The petroleum-derived olefin resin in the first layer preferably does not contain recycled pulverized materials so that they do not leach into the filler, such as chemicals, when the filler is contained therein.

[0038] The petroleum-derived olefin-based resin of the first layer and the petroleum-derived olefin-based resin and biomass-derived olefin-based resin of the second layer may contain additives as needed, such as inorganic fillers such as calcium carbonate, magnesium carbonate, aluminum oxide, magnesium oxide, titanium oxide, magnesium hydroxide, talc, mica, and clay, heat stabilizers, heat resistance improvers, light stabilizers, ultraviolet absorbers, antioxidants, impact modifiers, anti-fogging agents, antistatic agents, flame retardants, colorants, and pigments that have traditionally been commonly used in molding olefin-based resins.

[0039] The thickness ratio of the first layer to the second layer is not particularly limited, but as the ratio of the first layer increases, the content of the biomass-derived olefin resin decreases, and the friendliness to the environment decreases. On the other hand, as the ratio of the second layer increases, the content of the biomass-derived olefin resin increases, and moldability such as injection moldability and blow moldability decreases, making it difficult to manufacture the container. Therefore, it is preferable that the thickness of the second layer is the same as or thicker than the thickness of the first layer, and more preferably, the thickness of the second layer is 1 to 3 when the thickness of the first layer is 1.

[0040] When the biomass degree of a container measured according to ASTM D6866 is low, the content of the biomass-derived olefin resin is low, and the environmental friendliness is reduced. Conversely, when the biomass degree of a container is high, the content of the biomass-derived olefin resin is high, and moldability such as injection moldability and blow moldability is reduced, making it difficult to manufacture the container. Therefore, the biomass degree of a container measured according to ASTM D6866 is preferably 1 to 60%, more preferably 15 to 50%.

[0041] The olefin-based resin container of the second invention of the present application may have a first layer made of a petroleum-derived olefin-based resin and a second layer made of an olefin-based resin composition consisting of 100 parts by weight of petroleum-derived olefin-based resin and 35 to 200 parts by weight of a biomass-derived olefin-based resin, in which the first layer is the inner layer and the second layer is the outer layer, and a third layer made of a petroleum-derived olefin-based resin is laminated on the outside of the second layer of the olefin-based resin container of the second invention of the present application.

[0042] The petroleum-derived olefin-based resin that constitutes the third layer of the three-layer olefin-based resin container is as described above, and additives that have traditionally been used when molding olefin-based resins can be added as needed.

[0043] The three-layered olefin resin container has a structure in which the first and third layers are resin layers made of petroleum-derived olefin resins, and the second layer made of an olefin resin composition made of 100 parts by weight of petroleum-derived olefin resin and 35 to 200 parts by weight of biomass-derived olefin resin is sandwiched between them as an intermediate layer, and therefore has excellent moldability such as injection moldability and blow moldability, is easy to manufacture, and has excellent physical properties such as mechanical strength and self-supporting ability. Furthermore, even if a three-layered olefin resin container is filled with a filler such as a chemical or washed with a cleaning solution, the filler or cleaning solution does not come into contact with the second layer, so that even if the second layer contains a biomass-derived olefin resin, the chemical resistance is not reduced, and impurities are not eluted, resulting in a reduction in ESCR resistance.

[0044] The ratio of the thickness of the first layer, the second layer, and the third layer is not particularly limited, but if the ratio of the first layer and the third layer is high, the content of the olefin resin derived from biomass is low, and the friendliness to the environment is reduced, while if the ratio of the second layer is high, the content of the olefin resin derived from biomass is high, and the moldability of the injection moldability and the blow moldability is reduced, making it difficult to manufacture the container. Therefore, the thickness of the second layer is preferably the same as or thicker than the thickness of the first layer and the third layer, and more preferably, when the thickness of the first layer and the third layer is 1, the thickness of the second layer is 1 to 10. In addition, the thickness of the third layer is preferably the same as or thicker than the thickness of the first layer, and more preferably, when the thickness of the first layer is 1, the thickness of the third layer is 1 to 3. The ratio of the thickness of the first layer, the second layer, and the third layer is preferably within the range of 1:2:1 to 1:6:2.

[0045] The biomass ratio of the three-layer olefin resin container measured in accordance with ASTM D6866 is also preferably 1 to 60%, more preferably 15 to 50%, for the reasons mentioned above.

[0046] The petroleum-derived olefin resin in the third layer may be a recovered and crushed product of a petroleum-derived olefin resin molded body, or a recovered and crushed product of a molded body made of a petroleum-derived olefin resin and a biomass-derived olefin resin, for the purpose of cost reduction, waste reduction (reuse of waste), etc., or may include a recovered and crushed product of a petroleum-derived olefin resin molded body, a recovered and crushed product of a molded body made of a petroleum-derived olefin resin and a biomass-derived olefin resin, or a recovered and crushed product of a molded body made of a biomass-derived olefin resin. Since the recovered and crushed product may have reduced physical properties such as mechanical strength due to thermal history, the recovered and crushed product is preferably 300 parts by weight or less, more preferably 250 parts by weight or less, relative to 100 parts by weight of the petroleum-derived olefin resin in the third layer.

[0047] The shape of the olefin-based resin container of the first invention and the olefin-based resin container of the second invention is not particularly limited as long as it is a shape of a container, but is preferably a substantially cylindrical or rectangular tube shape, and an identification information display part capable of printing and updating identification information of the material of the container, the manufacturing history of the container, and the material of the contents of the container, or an identification information display part capable of attaching and peeling off a sheet on which identification information of the material of the container, the manufacturing history of the container, and the material of the contents of the container is printed, is provided at a position readable from the outside of the container wall. The capacity of the olefin-based resin container of the first invention and the olefin-based resin container of the second invention is not limited, but is 0.2 to 1000 liters, preferably 5 to 200 liters. In addition, in the case of a flexible container, it may be a so-called composite type container used as an inner bag for cardboard or metal, or it may be a self-supporting hard type container.

[0048] The identification information display portion is preferably a flat portion that can be read from the outside of the container wall, and is preferably installed on the top wall or side wall of the container so that it is easy to print and update the identification information of the container material, the container's manufacturing history, and the materials contained in the container, and so that a sheet on which the identification information of the container material, the container's manufacturing history, and the materials contained in the container is printed can be easily attached and peeled off.

[0049] The upper wall or side wall of the olefin-based resin container can be used as it is as the identification information display part. However, if the olefin-based resin container is a transparent container, it is difficult to print and update the identification information, and the container is likely to peel off during transportation and may be difficult to read from the outside. In addition, when a sheet with the identification information printed thereon is attached to a transparent container, the attachment strength is weak and the sheet may fall off during transportation. Therefore, it is preferable that the identification information display part is flat, colored, matte-finished or corona-treated, has irregularities, and is opaque.

[0050] The method of printing the identification information on the identification information display section or updating the identification information can be any conventionally known method, and although handwriting is also acceptable, it is preferable to employ a printing method that can be managed by a computer, such as laser printing or inkjet printing. By doing so, the olefin resin container of the present invention can be suitably used in the identification information management system described in the above Patent Document 3.

[0051] Furthermore, when printing the identification information on the identification information display section by laser printing or the like, the printing is accompanied by a chemical reaction such as oxidation with the laser, so it is preferable to use an olefin-based resin which is more reactive than polyethylene resin, and it is preferable to add inorganic pigments, organic pigments, inorganic fillers, and other additives which have conventionally been commonly used in the manufacture of olefin-based resin containers to the outer layer.

[0052] As the sheet on which the identification information is printed, a conventionally known adhesive label or sheet having an adhesive or glue applied to one side of a paper or plastic sheet is preferably used.

[0053] Furthermore, the identification information is preferably a barcode, a two-dimensional code, a QR code (registered trademark) or an RFID tag. EXAMPLES

[0054] Examples of the present invention will be described below, but the present invention is not limited to these examples, and various changes and modifications can be made without departing from the technical scope of the present invention.

[0055] (Example 1 of the first invention of the present application) For the inner layer, high density polyethylene resin (blown additive-free grade, melt flow rate = 0.05 g / 10 min, density = 0.957 g / cm 3 For the outer layer, a resin composition consisting of 100 parts by weight of high-density polyethylene resin (blow grade, melt flow rate = 0.03 g / 10 min, density = 0.954 g / cm 3A resin composition consisting of 100 parts by weight of olefin resin and 1 part by weight of blue pigment was fed to a single-screw extruder with a screw diameter of 100 mm, melt-kneaded at 210°C, and co-extruded into two layers to obtain a two-layer parison. The obtained parison was fed to a mold and blow-molded to obtain a 200-liter drum-shaped two-layer olefin resin container.

[0056] The obtained olefin resin container was composed of a cylindrical side wall and flat top and bottom walls, and an opening through which the contents could be filled and discharged and an identification information display part were formed in the top wall. The identification information display part was approximately rectangular and was formed by applying a matte finish to the surface of the top wall, and was readable from the outside and could be printed and updated by laser printing.

[0057] The sidewall of the obtained olefin resin container was cut to obtain a sample for tensile testing. The thickness of the inner layer of the sample for tensile testing was 1.5 mm, and the thickness of the outer layer was 2.0 mm. When the tensile test was performed according to JIS K7161-1:2014, the tensile strength was 36 MPa and the breaking elongation was 1000%.

[0058] In addition, to measure the cleanliness of the obtained olefin resin container, 5 liters of ultrapure water was poured into the olefin resin container, shaken and stirred for 15 seconds, and then left for 30 minutes.The number of fine particles of 0.2 μm or more that had seeped into the ultrapure water was then calculated using a particle counter, and was found to be 2 particles / milliliter when converted to a full container.

[0059] (Example 2 of the first invention of the present application) For the inner layer, high density polyethylene resin (blown additive-free grade, melt flow rate = 0.05 g / 10 min, density = 0.957 g / cm 3 ) for the intermediate layer, and a resin composition consisting of 100 parts by weight of a high-density polyethylene resin (blow grade, melt flow rate = 0.03 g / 10 min, density = 0.954 g / cm 3) and 1.8 parts by weight of a gray pigment, and a resin composition for the outer layer comprising a high-density polyethylene resin (blow grade, melt flow rate = 0.03 g / 10 min, density = 0.954 g / cm 3 Resin compositions consisting of 100 parts by weight of olefin resin and 1.8 parts by weight of a gray pigment were fed to single-screw extruders with screw diameters of 55 mm, 90 mm, and 55 mm, respectively, and melt-kneaded at 210°C, and co-extruded into three layers to obtain a three-layer parison. The obtained parison was fed to a mold and blow-molded to obtain a 20-liter, approximately square cylindrical, three-layer olefin resin container.

[0060] The obtained olefin-based resin container was composed of a rectangular cylindrical side wall and flat top and bottom walls, and an opening through which the contents could be filled and discharged and an identification information display part were formed in the top wall. The identification information display part was approximately rectangular and was formed by applying a matte finish to the surface of the top wall, and was readable from the outside and could be printed and updated by laser printing.

[0061] The sidewall of the obtained olefin resin container was cut to obtain a sample for tensile testing. The thickness of the inner layer of the sample for tensile testing was 0.4 mm, the thickness of the intermediate layer was 0.7 mm, and the thickness of the outer layer was 0.4 mm. When the tensile test was performed according to JIS K7161-1:2014, the tensile strength was 36 MPa and the breaking elongation was 1000%.

[0062] In addition, to measure the cleanliness of the obtained olefin resin container, 5 liters of ultrapure water was poured into the olefin resin container, shaken and stirred for 15 seconds, and then left for 30 minutes.The number of fine particles of 0.2 μm or more that had seeped into the ultrapure water was then calculated using a particle counter, and was found to be 3 particles / milliliter when converted to a full container.

[0063] (Comparative Example 1 of the First Invention of the Present Application) High density polyethylene resin (blow grade, melt flow rate = 0.03g / 10min, density = 0.954g / cm 3A resin composition consisting of 100 parts by weight of the polyester resin and 1.8 parts by weight of a gray pigment was fed to a single-screw kneading extruder with a screw diameter of 90 mm, and melt-kneaded and extruded at 210°C to obtain a parison. The obtained parison was fed to a mold and blow molded to obtain a 20-liter olefin resin container in a roughly rectangular cylindrical shape.

[0064] The obtained olefin-based resin container was composed of a rectangular cylindrical side wall and flat top and bottom walls, and the top wall was formed with an opening through which the contents could be filled and discharged, and an identification information display part. The identification information display part was approximately rectangular, and was formed by applying a matte finish to the surface of the top wall, and was readable from the outside, and could be printed and updated by laser printing.

[0065] The sidewall of the obtained olefin resin container was cut to obtain a sample for tensile testing. The thickness of the sample for tensile testing was 1.5 mm. When a tensile test was performed in accordance with JIS K7161-1:2014, the tensile strength was 36 MPa and the breaking elongation was 1000%.

[0066] In addition, to measure the cleanliness of the obtained olefin resin container, 5 liters of ultrapure water was poured into the olefin resin container, shaken and stirred for 15 seconds, and then left for 30 minutes.The number of fine particles of 0.2 μm or more that had seeped into the ultrapure water was then measured with a particle counter, and the number was calculated to be 110 particles / milliliter when converted to a full container.

[0067] (Comparative Example 2 of the First Invention of the Present Application) High density polyethylene resin (blow grade, melt flow rate = 0.03g / 10min, density = 0.954g / cm 3 A resin composition consisting of 100 parts by weight of the above resin composition was fed to a single-screw kneading extruder having a screw diameter of 90 mm, and melt-kneaded and extruded at 210° C. to obtain a parison. The obtained parison was fed to a mold and blow molded to obtain a 20-liter olefin-based resin container having a substantially rectangular cylindrical shape.

[0068] The obtained olefin resin container was composed of a rectangular cylindrical side wall and flat top and bottom walls, and an opening through which the contents could be filled and discharged and an identification information display part were formed on the top wall. The identification information display part was approximately rectangular and was formed by applying a matte finish to the surface of the top wall, and was readable from the outside and could be printed and updated by laser printing, but the printing speed was very slow.

[0069] The sidewall of the obtained olefin resin container was cut to obtain a sample for tensile testing. The thickness of the sample for tensile testing was 1.5 mm. When a tensile test was performed in accordance with JIS K7161-1:2014, the tensile strength was 36 MPa and the breaking elongation was 1000%.

[0070] In addition, to measure the cleanliness of the obtained olefin resin container, 5 liters of ultrapure water was poured into the olefin resin container, shaken and stirred for 15 seconds, and then left for 30 minutes.The number of fine particles of 0.2 μm or more that had seeped into the ultrapure water was then measured with a particle counter, and calculated based on the full capacity of the container to be 100 particles / milliliter.

[0071] As is clear from a comparison of the above Examples 1 and 2 with Comparative Examples 1 and 2, the olefin-based resin container of the first invention of the present application has high mechanical strength and excellent cleanliness, and can therefore be suitably used in the fields of transporting food and industrial products.

[0072] (Example of the second invention) The olefin resins used are as follows: [Petroleum-derived olefin resin] p-HDPE; High density polyethylene resin (polyethylene blow grade, melt flow rate = 0.03 g / 10 min, density = 0.954 g / cm 3 ) Recycled crushed products: Recycled products made by crushing blow molded box-shaped containers made of the above p-HDPE [Biomass-derived olefin resin] Bio-HDPE: High density polyethylene resin (Braskem, melt flow rate = 0.34 g / 10 min, density = 0.956 g / cm 3 , biomass ratio = 96%)

[0073] (Example 1 of the second invention of the present application) An olefin resin composition consisting of 100 parts by weight of p-HDPE for the first layer, 50 parts by weight of Bio-HDPE for the second layer, 100 parts by weight of p-HDPE, and 1 part by weight of pigment was fed into a single-screw extruder with a screw diameter of 65 mm, melt-kneaded at 210°C, and then injected into a crosshead die. The molten parison was then fed into a blow molding die having an approximately cubic cavity, and after clamping, compressed air was injected to perform blow molding, thereby obtaining a 50-liter olefin resin container consisting of two layers of approximately cubic shape.

[0074] The obtained olefin resin container had a rectangular cylindrical side wall and flat top and bottom walls, and the top wall had an opening through which the contents could be filled and discharged, and an identification information display part. The identification information display part was approximately rectangular, and was formed by applying a matte finish to the surface of the top wall, and was readable from the outside and could be printed and updated by laser printing.

[0075] The sidewall of the obtained olefin resin container was cut and the thickness of the center of the sidewall was measured to be about 2 mm, and the thickness of the end of the sidewall was about 3 mm. The sidewall of the obtained two-layer olefin resin container was also cut and the thickness of the first layer and the second layer was measured by observing the cross section. The results are shown in Table 1 as a ratio.

[0076] (Example 2 of the second invention) An olefin resin composition consisting of 100 parts by weight of p-HDPE for the first layer, 50 parts by weight of Bio-HDPE, 100 parts by weight of p-HDPE, and 1.8 parts by weight of pigment for the second layer was fed into a single-screw extruder with a screw diameter of 65 mm, melt-kneaded at 210°C, and then injected into a crosshead die. The molten parison was then fed into a blow molding die having a roughly cubic cavity, and after clamping, compressed air was injected to perform blow molding, thereby obtaining a 50-liter olefin resin container consisting of two roughly cubic layers.

[0077] The obtained olefin-based resin container was composed of a rectangular cylindrical side wall and flat top and bottom walls, and an opening through which the contents could be filled and discharged and an identification information display part were formed on the top wall. The identification information display part was approximately rectangular and was formed by applying a matte finish to the surface of the top wall, and was readable from the outside and could be printed and updated by laser printing.

[0078] The sidewall of the obtained olefin resin container was cut and the thickness of the center of the sidewall was measured to be about 2 mm, and the thickness of the end of the sidewall was about 3 mm. The sidewall of the obtained two-layer olefin resin container was also cut and the thickness of the first layer and the second layer was measured by observing the cross section. The results are shown in Table 1 as a ratio.

[0079] (Comparative Example 1 of the Second Invention of the Present Application) An olefin resin composition consisting of 100 parts by weight of Bio-HDPE and 1.8 parts by weight of pigment was fed into a single-screw extruder with a screw diameter of 65 mm, melt-kneaded at 210°C, and then injected into a crosshead die. The molten parison was then fed into a blow molding die having an approximately cubic cavity, and after clamping, compressed air was injected to blow mold the composition, resulting in a 50-liter, approximately cubic, single-layer olefin resin container.

[0080] The obtained olefin-based resin container was composed of a rectangular cylindrical side wall and flat top and bottom walls, and an opening through which the contents could be filled and discharged and an identification information display part were formed on the top wall. The identification information display part was approximately rectangular and was formed by applying a matte finish to the surface of the top wall, and was readable from the outside and could be printed and updated by laser printing.

[0081] The side wall of the obtained olefin resin container was cut and the thickness of the center part of the side wall was measured to be about 2 mm, and the thickness of the end part of the side wall was about 5 mm.

[0082] (Comparative Example 2 of the Second Invention of the Present Application) An olefin-based resin composition consisting of 100 parts by weight of Bio-HDPE, 100 parts by weight of p-HDPE, and 1.8 parts by weight of pigment was fed to a single-screw extruder with a screw diameter of 65 mm, melt-kneaded at 210°C, and then injected into a crosshead die. The molten parison was then fed into a blow molding die having an approximately cubic cavity, and after clamping, compressed air was injected to blow mold the composition, resulting in a 50-liter, approximately cubic, single-layer olefin-based resin container.

[0083] The obtained olefin-based resin container was composed of a rectangular cylindrical side wall and flat top and bottom walls, and an opening through which the contents could be filled and discharged and an identification information display part were formed on the top wall. The identification information display part was approximately rectangular and was formed by applying a matte finish to the surface of the top wall, and was readable from the outside and could be printed and updated by laser printing.

[0084] The side wall of the obtained olefin resin container was cut and the thickness of the center part of the side wall was measured to be about 2 mm, and the thickness of the end part of the side wall was about 5 mm.

[0085] (Examples 3 to 6 of the second invention) The first layer was made of p-HDPE, the second layer was made of an olefin-based resin composition consisting of p-HDPE, Bio-HDPE, and recycled pulverized material, and the third layer was made of an olefin-based resin composition consisting of p-HDPE, an antistatic agent, and a pigment, each of which was melt-kneaded at 210°C and then injected into a crosshead die to form a three-layer co-extrusion. The molten three-layer parison was then fed into a blow molding die having a roughly cubic cavity, and after clamping, compressed air was injected to perform blow molding, resulting in a roughly cubic three-layer 50-liter olefin-based resin container.

[0086] The obtained olefin-based resin container was composed of a rectangular cylindrical side wall and flat top and bottom walls, and an opening through which the contents could be filled and discharged and an identification information display part were formed on the top wall. The identification information display part was approximately rectangular and was formed by applying a matte finish to the surface of the top wall, and was readable from the outside and could be printed and updated by laser printing.

[0087] The sidewall of the obtained olefin resin container was cut and the thickness of the center of the sidewall was measured to be about 2 mm, and the thickness of the end of the sidewall was about 3 mm. The sidewall of the obtained three-layer olefin resin container was also cut and the cross section was observed to measure the thicknesses of the first layer, the second layer, and the third layer. The results are shown in Table 2 as ratios.

[0088] Using the side walls of the olefin resin containers of Examples 1 to 6 and Comparative Examples 1 and 2, a tensile test was performed in accordance with JIS K7127:1999 to measure the tensile strength (extrusion direction), tensile modulus (extrusion direction), and breaking elongation (extrusion direction). The measurement results are shown in Tables 1 and 2. In addition, using the olefin resin containers of Examples 1 to 6 and Comparative Examples 1 and 2, an ESCR test was performed in accordance with the stress cracking test for polyethylene cans of JIS Z1706:1995. Cases where no cracks were observed visually are indicated as "◯", and cases where cracks were observed are indicated as "cracks", and the results are shown in Tables 1 and 2. Furthermore, using parts of the olefin resin containers of Examples 1 to 6 and Comparative Examples 1 and 2, the biomass degree of the olefin resin containers was measured in accordance with ASTM D6866. The measurement results are shown in Tables 1 and 2.

[0089] [Table 1]

[0090] [Table 2]

[0091] The inner layer of the olefin-based resin container of the first invention of the present application is made of only an olefin-based resin container, and the inner layer of the olefin-based resin container of the second invention of the present application is made of an olefin-based resin derived from petroleum, and both of the inner layers of the olefin-based resin containers are characterized in that no additives are added. Therefore, the container has the characteristic of being a clean container, with no additives eluting into the liquid contained in the container. Therefore, the present inventor investigated the cleanliness of the olefin-based resin depending on whether or not there is an additive, and the results are described below.

[0092] As an example of the present invention, a 20-liter, approximately square cylindrical, three-layered olefin resin container was used, which was manufactured as in Example 2 of the first invention of the present application, and as a comparative example, a 20-liter, approximately square cylindrical, three-layered olefin resin container was used, which was manufactured in the same manner as in Example 2 of the first invention of the present application, except that the high-density polyethylene resin in the inner layer was blended with 1.0% by weight of a residual chlorine neutralizer for the catalyst and an antioxidant to prevent thermal degradation. These containers were then filled with 18×10 ultrapure water purified using an ultrapure water production system Cascada II.I manufactured by Nippon Pall Corporation. 6 Five liters of ultrapure water with a purity of Ω·m or more was poured in, and after stirring so that the ultrapure water was in contact with the entire inner surface of the container, 30 minutes later, the particles in the ultrapure water in the container were counted using a particle counter (KS-19F) manufactured by Rion Co., Ltd. As a result, in the olefin resin container of the embodiment of the present invention, the number of particles with a size of 0.03 μm or more was 7.8 pieces / milliliter, the number of particles with a size of 0.04 μm or more was 3.6 pieces / milliliter, and the number of particles with a size of 0.05 μm or more was 2.3 pieces / milliliter. On the other hand, in the olefin resin container of the comparative example, the number of particles with a size of 0.03 μm or more was 83.8 pieces / milliliter, the number of particles with a size of 0.04 μm or more was 47.4 pieces / milliliter, and the number of particles with a size of 0.05 μm or more was 13.5 pieces / milliliter. Thus, it can be seen that the olefin resin container of the present invention is clean.

[0093] In general, when olefin-based resin containers are obtained by blow molding olefin-based resins, antioxidants and the like are often added to the raw material olefin-based resins such as high-density polyethylene resins. Therefore, due to the action of additives such as antioxidants, the olefin-based resins are less susceptible to thermal decomposition or oxidative decomposition during melt kneading. Since the olefin-based resins are less susceptible to thermal degradation, the flow of the resin on the mold surface is smooth.

[0094] On the other hand, for clean olefin-based resin containers, that is, containers that do not dissolve or dissolve very little into the contents of the container, such as chemicals or special industrial intermediates, additives such as antioxidants are not added to the raw material olefin-based resin such as high-density polyethylene resin, or the amount of additives added is extremely small, in order to suppress dissolution into the contents of the container. Therefore, olefin-based resins for clean olefin-based resin containers are thermally decomposed or oxidatively decomposed during melt kneading, resulting in disturbances in the flow of the resin on the mold surface. In order to suppress this, it is preferable to extrude at a low temperature to suppress thermal deterioration as much as possible. The roughness of the inner layer surface of the container obtained in this way is preferably 8.4 μm in arithmetic mean roughness Ra and 40.6 μm in ten-point mean roughness Rz, more preferably 6.6 μm in arithmetic mean roughness Ra and 32.1 μm in ten-point mean roughness Rz, and even more preferably 1.3 μm in arithmetic mean roughness Ra and 7.5 μm in ten-point mean roughness Rz.

[0095] Furthermore, in order to investigate the cleanliness of the 20-liter, approximately square-tubular, three-layered olefin-based resin container prepared as in Example 2 of the first invention of the present application, the amount of metal eluted into the acidic chemical solution was measured by inductively coupled plasma mass spectrometry. That is, hydrochloric acid and ultrapure water were mixed to prepare 1 mol / liter hydrochloric acid, and 100 milliliters of this hydrochloric acid was poured into the olefin-based resin container, and the olefin-based resin container was sealed, and the container was inverted so that the mouth and bottom of the container were upside down and left at 50°C for 72 hours, and then naturally cooled to room temperature, and the hydrochloric acid in the container was taken out, and the amount of metal ions eluted into the hydrochloric acid was measured by inductively coupled plasma mass spectrometry. As a result, the amounts of iron, copper, zinc, cobalt, nickel, chromium, aluminum, sodium, titanium, and lithium were 1 μg / liter or less, the amounts of calcium and sulfur were 2 μg / liter or less, and the amount of silicon was 10 μg / liter or less.

[0096] The olefin-based resin container of the present invention is suitable as an olefin-based resin container that has high mechanical strength, can be made large in capacity, can be produced at low cost, has excellent chemical resistance, low elution, and is easy to manage for storage and transportation of the contents.The olefin-based resin container of the present invention is also suitable as an olefin-based resin container that is environmentally friendly, has high mechanical strength, excellent chemical resistance, low elution, excellent ESCR resistance, and is easy to manage for storage and transportation of the contents.

[0097] Olefin-based resin containers are often used as containers for storing chemicals in the semiconductor and liquid crystal fields. Examples of the above-mentioned chemicals in the semiconductor field include CMP slurry, photoresist, developer, etching solution, cleaning solution, etc., and in the liquid crystal field include photoresist, color resist, color filter material, etc.

[0098] On the other hand, chemicals in the semiconductor and liquid crystal fields are very expensive, and from a cost perspective, plastic drum users want to reduce the amount of residual chemicals as much as possible. Therefore, plastic drum users have a very strong demand for the can manufacturers to reduce the amount of residual chemicals.

[0099] Furthermore, in recent years, with the rise in awareness of resources and the environment, there has been an increasing demand for recycling used plastic drums. In the recycling of such plastic drums, the material remaining in the drums is unnecessary and requires waste liquid treatment, which incurs treatment costs. Therefore, from this point of view, there is a demand to reduce the amount of residue.

[0100] Furthermore, resin drums are formed by blow molding, and a parting line (PL) is formed on the inner surface of the can along the linear joint between a pair of dies, and a meat chunk (protrusion) is generated in which the resin material bulges toward the inside of the can along the parting line. Therefore, when the amount of remaining contents becomes small, the contents may be divided into two by the meat chunk. In contrast, since there is only one discharge tube, it may happen that only one of the two divided contents can be discharged. There is also a need to reduce the amount of remaining contents due to the structure unique to such resin drums. The height of the meat chunk is proportional to the wall thickness of the resin drum. Therefore, in large resin drums having a relatively large capacity of about 100 to 200 liters, there is an increased need to reduce the amount of remaining contents due to the above-mentioned structure.

[0101] FIG. 1 is a plan view of a bottom plate 1 of an olefin resin container for meeting the above-mentioned requirement to reduce the amount of residue in the container, FIG. 2(a) is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 2(b) is a cross-sectional view taken along the line BB in FIG. 1. In FIG. 1, a recess 2 for accommodating the amount of residue and a protrusion 3 for reducing the amount of residue are formed on the bottom plate 1. As shown in FIG. 2(a), a part 2a of the recess 2 for accommodating the amount of residue is hollowed out in a curved shape, and the contents 5 accommodated in the flat part 4 of the recess 2 move from the flat part 4 to the part 6 hollowed out in a curved shape, so that the contents 5 remaining in the recess 2 can be collected by inserting a discharge tube 7 into the container from an opening (not shown) at the top of the container and connecting the discharge tube 7 to a pump (not shown) under reduced pressure. The flat part 4 can also be inclined from the periphery to the part 5 hollowed out in a curved shape, as shown by the imaginary line 4a. If the recess 2 is thus composed of the inclined part 4a and the part 6 hollowed out in a curved shape, the contents 5 can be discharged more smoothly, which is preferable. [Explanation of symbols]

[0102] 1 Bottom plate 2 Recess 3. Convex part for reducing residue 4 Flat area 4a Slope 5. Contents 6. Curved hollowed out area 7 Discharge tube

Claims

1. An olefin-based resin container for chemicals, comprising an inner layer made of blown additive-free high-density polyethylene resin and an outer layer made of high-density polyethylene resin and additives laminated on the outside, and an identification information display section on which identification information of the container material, the manufacturing history of the container, and the materials of the container contents can be printed and updated, or an identification information display section on which a sheet on which identification information of the container material, the manufacturing history of the container, and the materials of the container contents can be attached and peeled off, is provided at a position readable from the outside of the container wall. The olefin-based resin container for chemicals is characterized in that, in order to facilitate management for reuse by the manufacturer after use of the olefin-based resin container for chemicals, a recess for accommodating residual chemical liquid is formed in the bottom plate of the olefin-based resin container for chemicals, the recess has a flat portion and a curved hollow portion, and the chemical liquid remaining in the bottom plate is configured to move from the flat portion to the curved hollow portion or is configured to slope downward from the peripheral portion of the recess to the curved hollow portion.

2. An olefin-based resin container having a first layer consisting of only a petroleum-derived olefin-based resin and a second layer consisting of an olefin-based resin composition consisting of 100 parts by weight of a petroleum-derived olefin-based resin and 35 to 200 parts by weight of a biomass-derived olefin-based resin and additives, the first layer being an inner layer and the second layer being an outer layer, and having an identification information display part on which identification information of the material of the container, the manufacturing history of the container, and the material of the contents of the container can be printed and updated at a position readable from the outside of the container wall, or an identification information display on which a sheet on which identification information of the material of the container, the manufacturing history of the container, and the material of the contents of the container can be printed and peeled off. an olefin-based resin container for chemicals having a bottom plate provided with a recess for accommodating residual chemical liquid, in order to facilitate management for reuse by the manufacturer after use of the olefin-based resin container for chemicals, the recess having a flat portion and a curvedly hollowed-out portion, and the chemical liquid remaining in the bottom plate is configured to move from the flat portion to the curvedly hollowed-out portion or is configured to slope downward from the peripheral portion of the recess to the curvedly hollowed-out portion.

3. The olefin-based resin container for chemicals according to claim 1 or 2, characterized in that the additive is one or more of a heat stabilizer, a heat resistance improver, a light stabilizer, an ultraviolet absorber, an antioxidant, an impact modifier, an anti-fogging agent, an antistatic agent, a flame retardant or a colorant.

4. 4. The olefin-based resin container for chemicals according to claim 3, characterized in that the biomass content of the container measured in accordance with ASTM D6866 is 1 to 60%.

5. 4. The olefin-based resin container for chemicals according to claim 3, characterized in that the identification information is a bar code, a two-dimensional code, a QR code (registered trademark), or an RFID tag.

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