Extrusion moldings for tube containers and tube containers

Abstract

To provide a technology relating to an extrusion molding tube containing a plant-derived polyethylene resin and having excellent stress crack resistance, seal strength, and surface smoothness.SOLUTION: An extrusion molding article for a tube container has a tube shape as a whole, and a five-layer structure in which an innermost layer, a first adhesive layer, an intermediate layer, a second adhesive layer, and an outermost layer are laminated in order. Each of the innermost layer and the outermost layer comprises a plant-derived polyethylene resin.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an extrusion molded product for a tubular container and a tubular container. [Background technology]

[0002] Laminated tubes are known as tube containers for storing toothpaste, cosmetics, etc. Laminated tubes are manufactured using a laminated sheet made by laminating polyethylene resin, special paper, aluminum foil, etc., as a raw material. Generally, laminated tubes are manufactured by rolling a laminated sheet into a cylindrical shape, overlapping both ends of the sheet, welding the overlapped parts, and joining a cap fitting part to the resulting container body.

[0003] Such laminate tubes have the following problems, for example. Since laminate tubes are manufactured by overlapping both ends, a step occurs at the overlapped portion, which causes problems in appearance. Since the end faces of the laminate sheet are exposed at the overlapped portion, the contents contained therein permeate into the laminate from the end faces, which deteriorates the physical properties of the laminate sheet. In addition, since laminate tubes include a process of rolling into a cylindrical shape and it is desired to make the above-mentioned step less noticeable, it is difficult to make the tube thicker, and it is difficult to maintain sufficient strength in a tube with a large diameter.

[0004] In order to solve the above problems of laminated tubes, it has been proposed to manufacture the container body of a tube container by extrusion molding (Patent Documents 1 and 2). A tube container manufactured by extrusion molding is called an extrusion molded tube. An extrusion molded tube is manufactured by continuously extruding molten resin into a tube shape using an extruder, then cutting it to an appropriate length, and joining a cap fitting portion to the resulting container body. In the case of a multi-layer extrusion molded tube, it is manufactured by extruding multiple types of molten resin into a single mold using separate extruders, and forming a multi-layered tube shape within the mold.

[0005] Most of the tube containers currently on the market are made from petroleum-derived resins. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-309406 [Patent Document 2] Japanese Patent Application Publication No. 11-309785 Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above problems with laminated tubes and from the viewpoint of environmental protection, the present inventors have attempted to develop an extrusion-molded tube containing a plant-derived polyethylene resin, but have found the following new problems.

[0008] When plant-derived polyethylene resin was used instead of petroleum-derived polyethylene resin, the extrusion molding tube was more susceptible to stress cracks. In addition, when a multi-layer extrusion molding tube was manufactured consisting of a resin layer containing plant-derived polyethylene resin and a resin layer with gas barrier properties, the seal strength tended to decrease. In addition, when plant-derived polyethylene resin was used instead of petroleum-derived polyethylene resin, the surface of the extrusion molding tube was not smooth and was more susceptible to surface roughness.

[0009] Therefore, an object of the present invention is to provide a technique for an extrusion molded tube that contains a plant-derived polyethylene resin and has excellent stress crack resistance, seal strength, and surface smoothness. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided an extrusion-molded product for a tube container, which has an overall tubular shape and a five-layer structure in which an innermost layer, a first adhesive layer, an intermediate layer, a second adhesive layer, and an outermost layer are laminated in that order, and each of the innermost layer and the outermost layer contains a plant-derived polyethylene resin.

[0011] According to another aspect of the present invention, a container body including the above-mentioned extrusion molded product with one end sealed; a cap fitting portion joined to the other end of the extrusion molded product whose one end is sealed; A tube container comprising: Effect of the Invention

[0012] According to the present invention, it is possible to provide a technique for an extrusion molded tube which contains a plant-derived polyethylene resin and has excellent stress crack resistance, seal strength, and surface smoothness. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a cross-sectional view showing a five-layer structure of an extrusion molded product according to one embodiment of the present invention. [Diagram 2] FIG. 1 is a plan view showing a configuration of a tube container according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described below. The following description is for the purpose of explaining the present invention in detail and is not intended to limit the present invention.

[0015] 1. Extrusion moldings for tube containers The extrusion molded product for tube containers has a tube shape as a whole and has a five-layer structure in which an innermost layer, a first adhesive layer, an intermediate layer, a second adhesive layer, and an outermost layer are laminated in this order, and each of the innermost layer and the outermost layer contains a plant-derived polyethylene resin. In the following description, the extrusion molded product for tube containers will be simply referred to as an "extrusion molded product."

[0016] In this specification, the percentage (%) of plant-derived polyethylene resin contained in an extrusion molded product is referred to as the “biomass ratio.” In other words, the biomass ratio refers to a value calculated by the following formula. Biomass ratio (%) = {(total mass of plant-derived polyethylene resin) / (total mass of all resins constituting the extrusion molding product)} x 100

[0017] 1-1.Structure The extrusion molded product has a tube shape as a whole, and has a five-layer structure in which an innermost layer, a first adhesive layer, an intermediate layer, a second adhesive layer, and an outermost layer are laminated in this order. FIG. 1 is a cross-sectional view showing a five-layer structure of an extrusion molded product according to one embodiment of the present invention. As shown in FIG. 1, the extrusion molded product 1 has a five-layer structure in which an innermost layer 1a, a first adhesive layer 1b, an intermediate layer 1c, a second adhesive layer 1d, and an outermost layer 1e are laminated in this order. When the extrusion molded product 1 shown in FIG. 1 is used as a container body of a tube container, the surface on the innermost layer 1a side is adjacent to the internal space of the tube container, and the surface on the outermost layer 1e side is adjacent to the external space of the tube container.

[0018] The extrusion molded product 1 may be in a cylindrical shape or an elliptical cylindrical shape. The extrusion molded product 1 has a circumferential length of, for example, 30 to 190 mm. The extrusion molded product 1 preferably has a circumferential length of 40 to 160 mm. The circumferential length refers to the outer periphery of the tubular extrusion molded product 1.

[0019] The extrusion molded product 1 has a thickness of, for example, 0.19 to 0.55 mm, preferably 0.24 to 0.5 mm. The thickness refers to the thickness of the wall of the tubular extrusion molded product 1, and is the average value of thicknesses measured at three points set at approximately equal intervals along the longitudinal direction of the extrusion molded product 1.

[0020] The innermost layer 1a has a thickness of, for example, 0.12 to 0.25 mm, preferably 0.14 to 0.24 mm. The first adhesive layer 1b has a thickness of, for example, 0.001 to 0.03 mm, preferably 0.005 to 0.02 mm. The intermediate layer 1c has a thickness of, for example, 0.01 to 0.1 mm, preferably 0.02 to 0.08 mm. The second adhesive layer 1d has a thickness of, for example, 0.001 to 0.03 mm, preferably 0.005 to 0.02 mm. The outermost layer 1e has a thickness of, for example, 0.06 to 0.2 mm, preferably 0.08 to 0.18 mm.

[0021] The extrusion molded product 1 can have any length, and may be longer than the container body of the tube container, or may be the same length as the container body of the tube container. In the former case, the extrusion molded product 1 is cut to the length of the container body of the tube container, and then used as the container body of the tube container.

[0022] 1-2.Resin The resins constituting the innermost layer 1a, the first adhesive layer 1b, the intermediate layer 1c, the second adhesive layer 1d, and the outermost layer 1e will be described in order below.

[0023] (Innermost layer 1a) The innermost layer 1a contains a plant-derived polyethylene resin. In a preferred embodiment, the innermost layer 1a contains a low-density polyethylene resin (Low Density Polyethylene: LDPE) and a linear low-density polyethylene resin (L-LDPE), and at least one of the low-density polyethylene resin (LDPE) and the linear low-density polyethylene resin (L-LDPE) is plant-derived.

[0024] That is, in a preferred embodiment, the innermost layer 1a is It may contain a plant-derived low-density polyethylene resin (biomass LDPE) and a plant-derived linear low-density polyethylene resin (biomass L-LDPE), It may contain a plant-derived low-density polyethylene resin (biomass LDPE) and a petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE), It may contain petroleum-derived low-density polyethylene resin (petroleum LDPE) and plant-derived linear low-density polyethylene resin (biomass L-LDPE).

[0025] Low-density polyethylene resin (LDPE) and linear low-density polyethylene resin (L-LDPE) are structurally different due to differences in the manufacturing methods. That is, low-density polyethylene resin (LDPE) is a polymer of ethylene, and has a structure in which ethylene is randomly branched and bonded. For this reason, low-density polyethylene resin (LDPE) has side chains with various carbon numbers bonded to the main chain, and the side chains include short-chain branches (e.g., short-chain branches with about 20 carbon atoms or less) and long-chain branches (e.g., long-chain branches with more than about 20 carbon atoms). On the other hand, linear low-density polyethylene resin (L-LDPE) is a copolymer of ethylene and α-olefin. For this reason, linear low-density polyethylene resin (L-LDPE) has no long-chain branches (e.g., long-chain branches with more than about 20 carbon atoms) bonded to the main chain, and only short-chain branches (e.g., short-chain branches with about 20 carbon atoms or less) bonded to the main chain.

[0026] In a further preferred embodiment, the innermost layer 1a is made of a plant-derived low-density polyethylene resin ( The present embodiment includes a plant-derived linear low-density polyethylene resin (biomass L-LDPE) and a plant-derived linear low-density polyethylene resin (biomass L-LDPE). This embodiment will be referred to as the "first embodiment" in the following description.

[0027] In another more preferred embodiment, the innermost layer 1a contains a plant-derived low-density polyethylene resin (biomass LDPE) and a petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE). This embodiment is referred to as "second embodiment" in the following description.

[0028] In another more preferred embodiment, the innermost layer 1a contains a petroleum-derived low-density polyethylene resin (petroleum-LDPE) and a plant-derived linear low-density polyethylene resin (biomass-LDPE). This embodiment is referred to as "third embodiment" in the following description.

[0029] The innermost layer 1a may contain a low-density polyethylene resin (LDPE) and a linear low-density polyethylene resin (L-LDPE) in a mass ratio of, for example, 9:1 to 1:9.

[0030] In the first embodiment, the innermost layer 1a contains a plant-derived low-density polyethylene resin (biomass LDPE) and a plant-derived linear low-density polyethylene resin (biomass L-LDPE) in a mass ratio of, for example, 9:1 to 4:6, preferably 8:2 to 4:6, more preferably 7:3 to 4:6, and even more preferably 6:4 to 4:6.

[0031] In the second embodiment, the innermost layer 1a contains a plant-derived low-density polyethylene resin (biomass LDPE) and a petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE) in a mass ratio of, for example, 9:1 to 4:6, preferably 9:1 to 5:5, more preferably 9:1 to 6:4, and even more preferably 9:1 to 7:3.

[0032] In the third embodiment, the innermost layer 1a contains petroleum-derived low-density polyethylene resin (petroleum LDPE) and plant-derived linear low-density polyethylene resin (biomass L-LDPE) in a mass ratio of, for example, 6:4 to 1:9, preferably 5:5 to 1:9, more preferably 4:6 to 1:9, and even more preferably 4:6 to 2:8.

[0033] Below, we will provide a detailed explanation of "plant-derived low-density polyethylene resin (biomass LDPE)", "plant-derived linear low-density polyethylene resin (biomass L-LDPE)", "petroleum-derived low-density polyethylene resin (petroleum LDPE)", and "petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE)".

[0034] "Plant-derived low-density polyethylene resin (biomass LDPE)" "Plant-derived low-density polyethylene resin (biomass LDPE)" is an ethylene polymer produced using plants as a raw material, and has a structure in which ethylene is randomly branched and bonded. "Plant-derived low-density polyethylene resin (biomass LDPE)" is, for example, a low-density polyethylene resin derived from sugarcane. Sugarcane-derived low-density polyethylene resin is an ethylene polymer produced using sugarcane as a raw material, and has a structure in which ethylene is randomly branched and bonded.

[0035] The density of "plant-derived low-density polyethylene resin (biomass LDPE)" is 0.91 g / cm 3 ~0.93g / cm 3 and preferably in the range of 0.915 g / cm 3 ~0.93g / cm 3 It is more preferable that the density of the resin described in this specification is a measured value obtained by a method in accordance with JIS K7112:1999.

[0036] The melt flow rate (MFR) of the "plant-derived low density polyethylene resin (biomass LDPE)" is preferably within the range of 0.1 g / 10 min to 10 g / 10 min, and more preferably within the range of 1 g / 10 min to 5 g / 10 min. The melt flow rate (MFR) of the resin described in this specification is a measured value obtained by a method conforming to JIS K7210:1999. Specifically, the melt flow rate is a measured value of the weight of the resin extruded in 10 minutes when a load of 21.18 N is applied to the resin at 190°C.

[0037] As the "plant-derived low-density polyethylene resin (biomass LDPE)", for example, plant-derived low-density polyethylene sold by Braskem can be used, and examples of such resins include those sold under the trade names SEB853, SBC818, SBF0323HC, STN7006, and SPB618.

[0038] "Plant-derived linear low-density polyethylene resin (biomass L-LDPE)" "Plant-derived linear low-density polyethylene resin (biomass L-LDPE)" is a copolymer of ethylene and α-olefin produced using plants as a raw material. "Plant-derived linear low-density polyethylene resin (biomass L-LDPE)" is, for example, a linear low-density polyethylene resin derived from sugarcane. Sugarcane-derived linear low-density polyethylene resin is a copolymer of ethylene and α-olefin produced using sugarcane as a raw material.

[0039] The "α-olefin" is at least one compound selected from the group consisting of α-olefins having 3 to 20 carbon atoms, and examples thereof include 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene.

[0040] The density of "plant-derived linear low-density polyethylene resin (biomass L-LDPE)" is 0.91 g / cm 3 ~0.93g / cm 3 and preferably in the range of 0.915 g / cm 3 ~0.93g / cm 3 In addition, the melt flow rate (MFR) of the "plant-derived linear low-density polyethylene resin (biomass L-LDPE)" is preferably in the range of 0.1 g / 10 min to 10 g / 10 min, and more preferably in the range of 1 g / 10 min to 5 g / 10 min.

[0041] As the "plant-derived linear low-density polyethylene resin (biomass L-LDPE)", for example, plant-derived linear low-density polyethylene sold by Braskem can be used, and examples thereof include resins sold under the trade names SLL118, SLL118 / 21, SLL218, SLL218 / 21, SLL318, SLH118, SLH218, and SLH0820 / 30AF.

[0042] "Petroleum-derived low-density polyethylene resin (petroleum LDPE)" "Petroleum-derived low-density polyethylene resin (petroleum LDPE)" is a polymer of ethylene produced using petroleum as a raw material, and has a structure in which ethylene is randomly branched and bonded.

[0043] The density of "petroleum-derived low-density polyethylene resin (petroleum LDPE)" is 0.91 g / cm 3 ~0.93g / cm 3 and preferably in the range of 0.915 g / cm 3 ~0.93g / cm 3 In addition, the melt flow rate (MFR) of the "petroleum-derived low density polyethylene resin (petroleum LDPE)" is preferably within a range of 0.1 g / 10 min to 10 g / 10 min, and more preferably within a range of 1 g / 10 min to 5 g / 10 min.

[0044] The "petroleum-derived low-density polyethylene resin (petroleum LDPE)" may be a commercially available petroleum-derived low-density polyethylene resin, examples of which include resin sold under the trade name Mirason by Dow Mitsui Polychemicals Co., Ltd., resin sold under the trade name Novatec by Japan Polyethylene Co., Ltd., resin sold under the trade name Petrothene by Tosoh Corporation, and resin sold under the trade name NUC by ENEOS NUC Corporation.

[0045] "Petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE)" "Petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE)" is a copolymer of ethylene and α-olefins produced using petroleum as a raw material.

[0046] The "α-olefin" is at least one compound selected from the group consisting of α-olefins having 3 to 20 carbon atoms, and examples thereof include 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene.

[0047] The density of "petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE)" is 0.91 g / cm 3 ~0.93g / cm 3 and preferably in the range of 0.915 g / cm 3 ~0.93g / cm 3 In addition, the melt flow rate (MFR) of the "petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE)" is preferably within a range of 0.1 g / 10 min to 10 g / 10 min, and more preferably within a range of 1 g / 10 min to 5 g / 10 min.

[0048] For the "petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE)", commercially available petroleum-derived linear low-density polyethylene resins can be used, examples of which include resins sold under the trade names Evolue, Neozex, or Ultozex by Prime Polymer Co., Ltd. and resins sold under the trade name Novatec by Japan Polyethylene Co., Ltd.

[0049] (1st adhesive layer 1b) The first adhesive layer 1b serves to bond the innermost layer 1a to the intermediate layer 1c. The first adhesive layer 1b contains, for example, an acid-modified polyethylene resin. The "acid-modified polyethylene resin" is preferably a maleic anhydride-modified polyethylene resin.

[0050] The first adhesive layer 1b typically contains a petroleum-derived acid-modified polyethylene resin. The "petroleum-derived acid-modified polyethylene resin" is a resin obtained by modifying petroleum-derived polyethylene with an unsaturated carboxylic acid or its anhydride. Such resins are known as adhesive resins because their adhesive properties are imparted by acid modification. Examples of unsaturated carboxylic acids or their anhydrides include acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, chloromaleic acid, butenylsuccinic acid, and their anhydrides.

[0051] The "petroleum-derived acid-modified polyethylene resin" is preferably a petroleum-derived maleic anhydride-modified polyethylene resin. More preferably, the "petroleum-derived acid-modified polyethylene resin" is a petroleum-derived maleic anhydride-modified low-density polyethylene resin (MA-modified LDPE), a petroleum-derived maleic anhydride-modified linear low-density polyethylene resin (MA-modified L-LDPE), or a mixture thereof.

[0052] "Petroleum-derived maleic anhydride modified low-density polyethylene resin (MA modified LDPE)" is a resin obtained by modifying an ethylene homopolymer produced using petroleum as a raw material with maleic anhydride.

[0053] The density of "petroleum-derived maleic anhydride modified low-density polyethylene resin (MA modified LDPE)" is 0.91 g / cm 3 ~0.93g / cm 3 and preferably in the range of 0.915 g / cm 3 ~0.93g / cm 3 It is more preferable that the density of the resin described in this specification is within the range of 100 to 2000. As described above, the density of the resin described in this specification is a measured value obtained by a method in accordance with JIS K7112:1999.

[0054] The melt flow rate (MFR) of the "petroleum-derived maleic anhydride-modified low-density polyethylene resin (MA-modified LDPE)" is preferably within the range of 0.1 g / 10 min to 10 g / 10 min, and more preferably within the range of 1 g / 10 min to 5 g / 10 min. As described above, the melt flow rate (MFR) of the resin described in this specification is a measured value obtained by a method conforming to JIS K7210:1999. Specifically, the melt flow rate is a measured value of the weight of the resin extruded in 10 minutes when a load of 21.18 N is applied to the resin at 190°C.

[0055] Examples of the "petroleum-derived maleic anhydride modified low-density polyethylene resin (MA modified LDPE)" that can be used include a resin sold under the trade name "MODIC" (registered trademark) by Mitsubishi Chemical Corporation and a resin sold under the trade name "ADMER" (registered trademark) by Mitsui Chemicals, Inc.

[0056] "Petroleum-derived maleic anhydride modified linear low-density polyethylene resin (MA modified L-LDPE)" is a resin obtained by modifying a copolymer of ethylene and α-olefin, produced using petroleum as a raw material, with maleic anhydride. "α-olefin" is at least one compound selected from the group consisting of α-olefins having 3 to 20 carbon atoms, such as 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene.

[0057] The density of "petroleum-derived maleic anhydride modified linear low-density polyethylene resin (MA modified L-LDPE)" is 0.91 g / cm 3 ~0.93g / cm 3 and preferably in the range of 0.915 g / cm 3 ~0.93g / cm 3 In addition, the melt flow rate (MFR) of the "petroleum-derived maleic anhydride modified linear low-density polyethylene resin (MA modified L-LDPE)" is preferably in the range of 0.1 g / 10 min to 10 g / 10 min, and more preferably in the range of 1 g / 10 min to 5 g / 10 min.

[0058] Examples of the "petroleum-derived maleic anhydride modified linear low-density polyethylene resin (MA modified L-LDPE)" that can be used include a resin sold by Mitsui Chemicals, Inc. under the trade name "ADMER" (registered trademark), a resin sold by Mitsubishi Chemical Corporation under the trade name "MODIC" (registered trademark), and a resin sold by ARKEMA under the trade name "OREVAC" (registered trademark).

[0059] (middle layer 1c) The intermediate layer 1c preferably contains a resin having gas barrier properties. The resin constituting the intermediate layer 1c may be a resin known as a resin having gas barrier properties. The resin constituting the intermediate layer 1c may be, for example, an ethylene-vinyl alcohol copolymer resin (EVOH), nylon (NY), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), or polyvinylidene chloride (PVDC), and is preferably an ethylene-vinyl alcohol copolymer resin (EVOH).

[0060] Examples of the ethylene-vinyl alcohol copolymer resin (EVOH) that can be used include a resin sold by Mitsubishi Chemical Corporation under the trade name "Soarnol" (registered trademark) and a resin sold by Kuraray Co., Ltd. under the trade name "Eval" (registered trademark).

[0061] (2nd adhesive layer 1d) The second adhesive layer 1d serves to bond the outermost layer 1e to the intermediate layer 1c. The second adhesive layer 1d contains, for example, an acid-modified polyethylene resin. The "acid-modified polyethylene resin" is preferably a maleic anhydride-modified polyethylene resin.

[0062] The second adhesive layer 1d typically contains a petroleum-derived acid-modified polyethylene resin. The "petroleum-derived acid-modified polyethylene resin" is preferably a petroleum-derived maleic anhydride-modified polyethylene resin. More preferably, the "petroleum-derived acid-modified polyethylene resin" is a petroleum-derived maleic anhydride-modified low-density polyethylene resin (MA-modified LDPE), a petroleum-derived maleic anhydride-modified linear low-density polyethylene resin (MA-modified L-LDPE), or a mixture thereof.

[0063] The "petroleum-derived acid-modified polyethylene resin" contained in the second adhesive layer 1d is the same as the "petroleum-derived acid-modified polyethylene resin" described in the first adhesive layer 1b, and the description thereof can be referred to. The second adhesive layer 1d may have the same resin composition as the first adhesive layer 1b, or may have a different resin composition from the first adhesive layer 1b.

[0064] (outermost layer 1e) The outermost layer 1e contains a plant-derived polyethylene resin. In a preferred embodiment, the outermost layer 1e contains a low-density polyethylene resin (LDPE) and a linear low-density polyethylene resin (L-LDPE), and at least one of the low-density polyethylene resin (LDPE) and the linear low-density polyethylene resin (L-LDPE) is plant-derived.

[0065] That is, in a preferred embodiment, the outermost layer 1e is It may contain a plant-derived low-density polyethylene resin (biomass LDPE) and a plant-derived linear low-density polyethylene resin (biomass L-LDPE), It may contain a plant-derived low-density polyethylene resin (biomass LDPE) and a petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE), It may contain petroleum-derived low-density polyethylene resin (petroleum LDPE) and plant-derived linear low-density polyethylene resin (biomass L-LDPE).

[0066] In a further preferred embodiment, the outermost layer 1e contains a plant-derived low-density polyethylene resin (biomass LDPE) and a plant-derived linear low-density polyethylene resin (biomass L-LDPE). This embodiment is referred to as "first embodiment" in the following description.

[0067] In another more preferred embodiment, the outermost layer 1e contains a plant-derived low-density polyethylene resin (biomass LDPE) and a petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE). This embodiment is referred to as "second embodiment" in the following description.

[0068] In another more preferred embodiment, the outermost layer 1e contains a petroleum-derived low-density polyethylene resin (petroleum-LDPE) and a plant-derived linear low-density polyethylene resin (biomass-LDPE). This embodiment is referred to as "third embodiment" in the following description.

[0069] The outermost layer 1e can contain a low-density polyethylene resin (LDPE) and a linear low-density polyethylene resin (L-LDPE) in a mass ratio of, for example, 9:1 to 1:9.

[0070] In the first embodiment, the outermost layer 1e contains a plant-derived low-density polyethylene resin (biomass LDPE) and a plant-derived linear low-density polyethylene resin (biomass L-LDPE) in a mass ratio of, for example, 9:1 to 4:6, preferably 8:2 to 4:6, more preferably 7:3 to 4:6, and even more preferably 6:4 to 4:6.

[0071] In the second embodiment, the outermost layer 1e contains a plant-derived low-density polyethylene resin (biomass LDPE) and a petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE) in a mass ratio of, for example, 9:1 to 4:6, preferably 9:1 to 5:5, more preferably 9:1 to 6:4, and even more preferably 9:1 to 7:3.

[0072] In the third embodiment, the outermost layer 1e contains petroleum-derived low-density polyethylene resin (petroleum LDPE) and plant-derived linear low-density polyethylene resin (biomass L-LDPE) in a mass ratio of, for example, 6:4 to 1:9, preferably 5:5 to 1:9, more preferably 4:6 to 1:9, and even more preferably 4:6 to 2:8.

[0073] The resins contained in the outermost layer 1e, i.e., "plant-derived low-density polyethylene resin (biomass LDPE)", "plant-derived linear low-density polyethylene resin (biomass L-LDPE)", "petroleum-derived low-density polyethylene resin (petroleum LDPE)", and "petroleum-derived linear low-density polyethylene resin (petroleum L-LDPE)", are the same as those described for the innermost layer 1a, and the descriptions thereof can be referred to. The outermost layer 1e may have the same resin composition as the innermost layer 1a, or may have a resin composition different from that of the innermost layer 1a.

[0074] (Additives) The innermost layer 1a, the first adhesive layer 1b, the intermediate layer 1c, the second adhesive layer 1d, and the outermost layer 1e are mainly composed of resin, but may contain known additives in addition to the resin as necessary. As the additives, various additives known as resin additives can be used. As the additives, for example, antioxidants, ultraviolet absorbers, weather resistance agents, antistatic agents, fillers, crystal nucleating agents, color pigments, matting agents, color prevention agents, anti-fogging agents, flame retardants, antiblocking agents, lubricants (including slip agents and release agents), and CO 2 The total content of the additives can be, for example, 0.01 to 10 parts by mass with respect to 100 parts by mass of the resin of each layer.

[0075] (Biomass ratio) The extrusion-molded product 1 having the above-mentioned five layers contains the plant-derived polyethylene resin in an amount, for example, greater than 40% by mass. The extrusion-molded product 1 contains the plant-derived polyethylene resin in an amount of preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. That is, the proportion of the plant-derived polyethylene resin contained in the extrusion-molded product 1 (i.e., the biomass degree) is, for example, greater than 40% by mass, preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.

[0076] The upper limit of the proportion of plant-derived polyethylene resin contained in the extrusion molded product 1 (that is, the biomass ratio) is, for example, 85 mass %.

[0077] 1-3. Manufacturing method The extrusion molded product 1 can be manufactured by a known co-extrusion molding method, that is, by extruding the resin constituting the innermost layer 1a, the resin constituting the first adhesive layer 1b, the resin constituting the intermediate layer 1c, the resin constituting the second adhesive layer 1d, and the resin constituting the outermost layer 1e into one die by separate extruders, and forming a tube shape with a five-layer structure in the die.

[0078] In this specification, the term "extrusion molded product" refers to a product formed into a tubular shape by extrusion molding. In other words, the term "extrusion molded product" refers to a product that has a tubular shape immediately after extrusion molding. Therefore, the term "extrusion molded product" does not include a product that is extruded into a sheet shape and then rolled into a tubular shape.

[0079] 2. Molded products for tube containers The extrusion molded product 1 may have one or more additional layers on the extrusion molded product 1. That is, according to another aspect, a molded product for a tube container is provided, which includes an extrusion molded product and one or more layers provided on the extrusion molded product. In the following description, this molded product for a tube container is simply referred to as a "molded product."

[0080] The additional layer can be formed on the extrusion molded product according to known decoration techniques, for example, by printing, painting (e.g., clear coating for surface protection of the printed layer), labeling, hot stamping, shrink film application, vapor deposition, or film transfer. The additional layer can be one layer or multiple layers, for example, 1 to 5 layers.

[0081] 3. Tube containers The tube container is a container body including the above-mentioned extrusion molded product with one end sealed; a cap fitting portion joined to the other end of the extrusion molded product whose one end is sealed; It is equipped with:

[0082] Alternatively, the tube container may include: A container body including the above-mentioned molded article with one end sealed; a cap fitting portion joined to the other end of the molded article whose one end is sealed; It is equipped with:

[0083] A tube container according to one embodiment of the present invention will be described below with reference to Fig. 2. Fig. 2 is a plan view showing the configuration of a tube container according to one embodiment of the present invention.

[0084] As shown in Fig. 2, the tube container 10 includes a container body 11 and a cap fitting portion 12 joined to the container body 11. The tube container 10 is used by filling the container body 11 with contents and fitting a cap to the cap fitting portion 12. Here, the contents may be a high-viscosity liquid or a semi-solid. Examples of the contents include daily necessities such as face wash, cosmetics, toothpaste, and hand cream, and foods such as jam and butter.

[0085] The container body 11 is obtained by sealing one end of the extrusion molded product 1 described above. The sealing can be performed by a method known as an end sealing process for tube containers, for example, a heat sealing method, an ultrasonic sealing method, or a hot air sealing method. As described above, the extrusion molded product 1 may be provided with one or more additional layers on the outer surface before sealing one end. That is, the container body 11 may further include one or more additional layers formed according to a known decoration technique, for example, by printing, painting (for example, clear painting for protecting the surface of the printed layer), labeling, hot stamping, shrink film application, vapor deposition, or film transfer.

[0086] As shown in FIG. 2, the container body 11 includes a body portion 21 and a seal portion 22 provided at one end of the body portion 21.

[0087] The body portion 21 is an unsealed portion of the extrusion molded product 1 or a molded product. The end portion of the body portion 21 where the seal portion 22 is not provided has a circular or elliptical cylindrical shape when viewed from the opening.

[0088] The sealed portion 22 is a portion formed by thermally welding one end of the extrusion molded product 1 or a molded product. The sealed portion 22 has a flat shape, and the opposing inner surfaces are sealed. The sealed portion 22 closes one end of the container body 11.

[0089] The cap fitting portion 12 is provided at the end of the body portion 21 opposite to the end where the seal portion 22 is provided. The cap fitting portion 12 has a shoulder portion 31 that is integrally continuous with the end of the body portion 21 where the seal portion 22 is not provided, and a cylindrical mouth portion 32 provided at the center of the shoulder portion 31. The cap fitting portion 12 is manufactured by injection molding or compression molding separately from the body portion 21, and is joined to the body portion 21. In the case of injection molding, the formation of the cap fitting portion 12 and the joining of the cap fitting portion 12 to the container body 11 may be performed simultaneously by insert molding, or the cap fitting portion 12 may be injection molded as a separate part and then joined to the container body 11 by ultrasonic welding.

[0090] The shoulder 31 has an outer surface facing the exterior space of the tube container 10 and an inner surface facing the interior space of the tube container 10, each of which has a truncated cone shape tapering from the interior space to the exterior space. The outer peripheral edge of the shoulder 31 is continuous with the body 21. The mouth 32 is provided at the center of the shoulder 31 so as to protrude outward.

[0091] 3.Effects As described above, the extrusion molded product, molded product, and tube container of the present invention have a five-layer structure in which the innermost layer 1a, the first adhesive layer 1b, the intermediate layer 1c, the second adhesive layer 1d, and the outermost layer 1e are laminated in this order, and each of the innermost layer 1a and the outermost layer 1e contains a plant-derived polyethylene resin. In the present invention, the extrusion molded tube containing the plant-derived polyethylene resin is provided with an adhesive layer as an independent layer to give it a five-layer structure, thereby achieving excellent stress crack resistance, excellent seal strength, and excellent surface smoothness.

[0092] Preferably, the extrusion molded product, molded product, and tube container of the present invention have the above-mentioned five-layer structure, and further each of the innermost layer 1a and the outermost layer 1e contains a low-density polyethylene resin (LDPE) and a linear low-density polyethylene resin (L-LDPE), at least one of which is derived from a plant. In the present invention, by using such a combination of specific resins, it is possible to achieve better stress crack resistance, better seal strength, and better surface smoothness.

[0093] In addition, the extrusion molded product, molded product, and tubular container of the present invention have the following advantages: Since the extrusion molded product, molded product, and tubular container of the present invention contain a plant-derived polyethylene resin, they are less susceptible to CO2 emissions than petroleum-derived polyethylene resins. 2 This can contribute to reducing emissions. In addition, since the extrusion molded product, molded product, and tube container of the present invention are manufactured by extrusion molding, there are no overlapping parts (i.e., seams) as seen in laminated tubes, and a seamless appearance can be achieved. In addition, since the extrusion molded product, molded product, and tube container of the present invention are manufactured by extrusion molding, they can be easily made thicker than laminated tubes, and even tube containers with large diameters can maintain sufficient strength.

[0094] Furthermore, the extrusion molded product, molded product, and tube container of the present invention have the following advantages because they have the above-mentioned five-layer structure. In a multi-layer structure tube, when the innermost layer and the outermost layer are bonded to an intermediate layer having gas barrier properties, two methods are considered: a method of incorporating an adhesive resin into the innermost layer and the outermost layer, and a method of providing an adhesive layer containing an adhesive resin between the innermost layer and the intermediate layer and between the outermost layer and the intermediate layer. In the present invention, the first adhesive layer 1b and the second adhesive layer 1d are provided as independent layers to form a five-layer structure according to the latter method, so that it is not necessary to incorporate an adhesive resin into the innermost layer 1a or the outermost layer 1e. Therefore, in the present invention, the proportion of plant-derived polyethylene resin contained in the innermost layer 1a or the outermost layer 1e can be increased to a maximum of 100% by mass, thereby increasing the biomass degree of the extrusion molded product.

[0095] In addition, in the present invention, the first adhesive layer 1b and the second adhesive layer 1d are provided as independent layers to form a five-layer structure, so that the adhesive resin is not diluted as in the case where the adhesive resin is incorporated in the innermost layer 1a or the outermost layer 1e. Therefore, in the present invention, the amount of adhesive resin used can be reduced. Since the adhesive resin has a special chemical structure to exhibit adhesive properties and is a relatively expensive material, reducing the amount of adhesive resin used can reduce costs. EXAMPLES

[0096] [Example 1] [1-1] Manufacturing of extrusion molded products As resins for the innermost layer and the outermost layer, the following resins A to G were prepared.

[0097] Resin A: Petroleum-derived low-density polyethylene (density: 0.92 g / cm 3 , MFR: 1.9g / 10min (190℃, 21.18N load)) (hereinafter referred to as "petroleum LDPE"); Resin B: Plant-derived low-density polyethylene (density: 0.923 g / cm 3 , MFR: 2.7g / 10min (190℃, 21.18N load)) (hereinafter referred to as "biomass LDPE"); Resin C: Plant-derived linear low-density polyethylene (density: 0.916 g / cm 3 , MFR: 2.3g / 10min (190℃, 21.18N load)) (hereinafter referred to as "Biomass L-LDPE-1"); Resin D: Petroleum-derived maleic anhydride-modified low-density polyethylene (density: 0.93 g / cm 3 , MFR: 1.0 g / 10 min (190°C, 21.18 N load) (hereinafter referred to as "MA-modified LDPE-1"); Resin E: Petroleum-derived maleic anhydride-modified low-density polyethylene (density: 0.92 g / cm 3 , MFR: 1.5g / 10min (190°C, 21.18N load) (hereinafter referred to as "MA-modified LDPE-2"); Resin F: Plant-derived linear low-density polyethylene (density: 0.916 g / cm 3 , MFR: 1.0 g / 10 min (190°C, 21.18 N load) (hereinafter referred to as "Biomass L-LDPE-2"); Resin G: Petroleum-derived linear low-density polyethylene (density: 0.925 g / cm 3 , MFR: 1.9g / 10min (190℃, 21.18N load) (hereinafter referred to as "petroleum L-LDPE").

[0098] The adhesive resin for the first and second adhesive layers was petroleum-derived maleic anhydride-modified low-density polyethylene (density: 0.93 g / cm 3 , MFR: 1.0 g / 10 min (210°C, 21.18 N load) was prepared.

[0099] As the resin for the intermediate layer (barrier layer), ethylene-vinyl alcohol copolymer (density: 1.14 g / cm 3 , MFR: 12.0 g / 10 min (210°C, 21.18 N load) was prepared.

[0100] <Example 1> "Petroleum LDPE" was used as the resin that constitutes the innermost layer and the outermost layer. 0.1 parts by mass of antioxidant and 2.5 parts by mass of titanium oxide as a coloring pigment were added to 100 parts by mass of "petroleum LDPE" to obtain a mixture. Pellets of the above mixture, pellets of adhesive resin, and pellets of ethylene-vinyl alcohol copolymer were respectively put into three hoppers of a single-screw tube extruder. The set temperatures of the extruder and die were set to 170-200°C, and a tube with a five-layer structure of the innermost layer / first adhesive layer / middle layer / second adhesive layer / outermost layer was molded under molding conditions of a production speed of 60 tubes / min and a take-up speed of 10.8 m / min.

[0101] The resulting tube (i.e., extrusion molded product) had a circumference of 157 mm, a length of 180 mm, and an average wall thickness of 0.46 mm. The thicknesses of the innermost layer, first adhesive layer, intermediate layer, second adhesive layer, and outermost layer were 0.225 mm, 0.01 mm, 0.04 mm, 0.01 mm, and 0.175 mm, respectively.

[0102] <Example 2> A tube having a five-layer structure was produced in the same manner as in Example 1, except that "biomass LDPE" was used as the resin constituting the innermost layer and the outermost layer.

[0103] <Example 3> A tube having a five-layer structure was produced in the same manner as in Example 1, except that "Biomass L-LDPE-1" was used as the resin constituting the innermost layer and the outermost layer.

[0104] <Example 4> In Example 4, a tube having a three-layer structure was manufactured. A mixed resin obtained by dry blending "MA-modified LDPE-1", "MA-modified LDPE-2" and "biomass L-LDPE-2" in a mass ratio of 50:20:30 was used as the resin constituting the innermost layer and the outermost layer. 0.1 parts by mass of an antioxidant and 2.5 parts by mass of titanium oxide as a coloring pigment were added to 100 parts by mass of the mixed resin to obtain a mixture. Pellets of the above mixture and pellets of an ethylene-vinyl alcohol copolymer were respectively put into two hoppers of a single-screw tube extruder. The set temperatures of the extruder and die were set to 170 to 200°C, and a tube having a three-layer structure of the innermost layer / middle layer / outermost layer was molded under molding conditions of a production speed of 60 tubes / min and a take-up speed of 10.8 m / min.

[0105] The resulting tube (i.e., extrusion molded product) had a circumference of 157 mm, a length of 180 mm, and an average wall thickness of 0.46 mm. The thicknesses of the innermost layer, intermediate layer, and outermost layer were 0.225 mm, 0.06 mm, and 0.175 mm, respectively.

[0106] <Example 5> A tube having a five-layer structure was produced in the same manner as in Example 1, except that a mixed resin obtained by dry blending "biomass LDPE" and "biomass L-LDPE-1" in a mass ratio of 50:50 was used as the resin constituting the innermost layer and the outermost layer.

[0107] <Example 6> A tube having a five-layer structure was produced in the same manner as in Example 1, except that a mixed resin obtained by dry blending "biomass LDPE" and "petroleum L-LDPE" in a mass ratio of 85:15 was used as the resin constituting the innermost layer and the outermost layer.

[0108] <Example 7> A tube having a five-layer structure was produced in the same manner as in Example 1, except that a mixed resin obtained by dry blending "biomass LDPE" and "biomass L-LDPE-1" in a mass ratio of 70:30 was used as the resin constituting the innermost layer and the outermost layer.

[0109] <Example 8> A tube having a five-layer structure was produced in the same manner as in Example 1, except that a mixed resin obtained by dry blending "biomass LDPE" and "petroleum L-LDPE" in a mass ratio of 70:30 was used as the resin constituting the innermost layer and the outermost layer.

[0110] <Example 9> A tube having a five-layer structure was produced in the same manner as in Example 1, except that a mixed resin obtained by dry blending "petroleum LDPE" and "biomass L-LDPE-1" in a mass ratio of 30:70 was used as the resin constituting the innermost layer and the outermost layer.

[0111] [1-2] Evaluation method The physical properties of the tubes of Examples 1 to 9 were evaluated by the following methods.

[0112] <Stress crack resistance> One end of the obtained tube was heat sealed, and a 5 cm section was cut from the end to prepare a test piece. The test piece was immersed in a 10% Igepal (poly(oxyethylene) nonylphenyl ether) aqueous solution and stored in a 65°C thermostatic chamber for a specified time. After storage, the presence or absence of cracks was visually determined. Evaluation criteria 〇: No cracks after 24 hours of storage △: Small cracks are observed after 6 hours of storage. ×: Large cracks were observed after 6 hours of storage (leading to leakage of contents)

[0113] <Ultrasonic seal strength> Using an ultrasonic sealer (TS-2 manufactured by Branson, Power Supply 2000X), the sample was sealed under the sealing conditions of 90% amplitude and 200 msec welding time, and then evaluated by the method described below. The sealed sample was cut into 15 mm wide strips to prepare test pieces. The sealed portion of the test piece was opened 180° and attached to the grip of a tensile tester (manufactured by Shimadzu Corporation, product name AUTOGRAPH AGS-X). A T-type tensile test was performed at a tensile speed of 50 mm / min, and the stable value was taken as the ultrasonic seal strength [N]. Evaluation criteria 〇 :35 N or more △: 23 N or more, less than 35 N × :Less than 23 N

[0114] <Surface roughness> The surface roughness of the resulting tube was visually inspected. Evaluation criteria 〇: No roughness △: Slightly rough ×: Significant roughness

[0115] <Biomass ratio> The percentage (%) of plant-derived polyethylene resin contained in the obtained tube, i.e., the "biomass ratio", was calculated using the following formula. Biomass ratio (%) = {(total mass of plant-derived polyethylene resin) / (total mass of all resins constituting the extrusion molding product)} x 100

[0116] [1-3] Evaluation results The "resin compositions of the innermost and outermost layers" and "evaluation results" of the tubes of Examples 1 to 9 are shown in Table 1 below. The "blending amount" values ​​in the table represent parts by mass, and the "ultrasonic seal strength" values ​​represent Newtons.

[0117] [Table 1]

[0118] The tube of Example 1 has a five-layer structure of an innermost layer / first adhesive layer / middle layer / second adhesive layer / outermost layer, and each of the innermost layer and the outermost layer is made of petroleum-derived polyethylene resin and does not contain plant-derived polyethylene resin. The tube of Example 1 showed good results in all of the stress crack resistance test, ultrasonic seal strength test, and surface roughness test.

[0119] The tubes of Examples 2 and 3 have a five-layer structure similar to that of Example 1, with the innermost layer and the outermost layer each being composed of a plant-derived polyethylene resin. The tube of Example 2 was more susceptible to stress cracking and tended to have a lower seal strength than the tube of Example 1, but both were at a level that would not be a problem in practical use. Also, the tube of Example 3 was slightly roughened on the surface compared to the tube of Example 1, but was at a level that would not be a problem in practical use.

[0120] The tube of Example 4 has a three-layer structure of innermost layer / middle layer / outermost layer, with the innermost layer and outermost layer each being composed of a plant-derived polyethylene resin and an adhesive resin. The tube of Example 4 showed good results in all of the stress crack resistance test, ultrasonic seal strength test, and surface roughness test. However, since the adhesive resin is incorporated into the innermost layer and the outermost layer of the tube of Example 4, the adhesive resin is diluted and a large amount of adhesive resin is used. Therefore, the tube of Example 4 has a lower biomass degree than the tubes with a five-layer structure (Examples 2, 3, and 5 to 8).

[0121] The tubes of Examples 5 and 7 have a five-layer structure similar to that of Example 1, with the innermost layer and the outermost layer each being composed of a plant-derived low-density polyethylene resin and a plant-derived linear low-density polyethylene resin. Both the tubes of Examples 5 and 7 showed good results in all of the stress crack resistance test, ultrasonic seal strength test, and surface roughness test.

[0122] The tubes of Examples 6 and 8 have a five-layer structure similar to that of Example 1, with the innermost layer and the outermost layer each being composed of a plant-derived low-density polyethylene resin and a petroleum-derived linear low-density polyethylene resin. Both the tubes of Examples 6 and 8 showed good results in all of the stress crack resistance test, ultrasonic seal strength test, and surface roughness test.

[0123] The tube of Example 9 has a five-layer structure similar to that of Example 1, and the innermost layer and the outermost layer are each composed of a petroleum-derived low-density polyethylene resin and a plant-derived linear low-density polyethylene resin. The tube of Example 9 showed good results in all of the stress crack resistance test, ultrasonic seal strength test, and surface roughness test. The following claims as originally filed of this application are given as embodiments. [1] An extrusion-molded product for tube containers, which has an overall tubular shape and a five-layer structure in which an innermost layer, a first adhesive layer, an intermediate layer, a second adhesive layer, and an outermost layer are laminated in that order, and each of the innermost layer and the outermost layer contains a plant-derived polyethylene resin. [2] The extrusion-molded product described in [1], wherein each of the innermost layer and the outermost layer contains a low-density polyethylene resin and a linear low-density polyethylene resin, and at least one of the low-density polyethylene resin and the linear low-density polyethylene resin is derived from plants. [3] The extrusion-molded product according to [2], wherein the innermost layer and the outermost layer each contain a plant-derived low-density polyethylene resin and a plant-derived linear low-density polyethylene resin. [4] The extrusion molded product according to [2], wherein each of the innermost layer and the outermost layer contains a plant-derived low-density polyethylene resin and a petroleum-derived linear low-density polyethylene resin. [5] The extrusion molded product according to [2], wherein each of the innermost layer and the outermost layer contains a petroleum-derived low-density polyethylene resin and a plant-derived linear low-density polyethylene resin. [6] The extrusion-molded product according to any one of [2] to [5], wherein each of the innermost layer and the outermost layer contains the low-density polyethylene resin and the linear low-density polyethylene resin in a mass ratio of 9:1 to 1:9. [7] The extrusion molded product according to any one of [1] to [6], wherein the extrusion molded product contains more than 40 mass% of a plant-derived polyethylene resin. [8] The extrusion-molded product according to any one of [1] to [7], wherein each of the first adhesive layer and the second adhesive layer contains an acid-modified polyethylene resin. [9] The extrusion molded product according to [8], wherein the acid-modified polyethylene resin is a maleic anhydride-modified polyethylene resin.

[10] The extrusion molding according to any one of [1] to [9], wherein the intermediate layer contains a resin having gas barrier properties.

[11] The extrusion molded product according to

[10] , wherein the resin is an ethylene-vinyl alcohol copolymer resin.

[12] An extrusion molding according to any one of [1] to

[11] , one or more layers disposed on the extrusion; A molded article for a tube container comprising:

[13] A container body including the extrusion molded article according to any one of [1] to

[11] having one end sealed or the molded article according to

[12] having one end sealed; a cap fitting portion joined to the other end of the extrusion molded product having one end sealed or the molded product having one end sealed; A tube container comprising: [Explanation of symbols]

[0124] 1...extrusion molded product, 1a...innermost layer, 1b...first adhesive layer, 1c...middle layer, 1d...second adhesive layer, 1e...outermost layer, 10...tube container, 11...container body, 12...cap fitting portion, 21...body portion, 22...seal portion, 31...shoulder portion, 32...mouth portion.

Claims

1. An extrusion-molded product for a tube container, having a seamless tube shape as a whole and a five-layer structure in which an innermost layer, a first adhesive layer, an intermediate layer, a second adhesive layer, and an outermost layer are laminated in this order, each of the innermost layer and the outermost layer containing a low-density polyethylene resin and a linear low-density polyethylene resin, and at least one of the low-density polyethylene resin and the linear low-density polyethylene resin being plant-derived.

2. The extrusion-molded product according to claim 1, wherein each of the innermost layer and the outermost layer contains a plant-derived low-density polyethylene resin and a plant-derived linear low-density polyethylene resin.

3. The extrusion-molded product according to claim 1, wherein each of the innermost layer and the outermost layer contains a plant-derived low-density polyethylene resin and a petroleum-derived linear low-density polyethylene resin.

4. The extrusion-molded product according to claim 1, wherein each of the innermost layer and the outermost layer contains a petroleum-derived low-density polyethylene resin and a plant-derived linear low-density polyethylene resin.

5. The extrusion-molded product according to any one of claims 1 to 4, wherein each of the innermost layer and the outermost layer contains the low-density polyethylene resin and the linear low-density polyethylene resin in a mass ratio of 9:1 to 1:

9.

6. The extrusion-molded product according to any one of claims 1 to 5, wherein the extrusion-molded product contains a plant-derived polyethylene resin in an amount exceeding 40% by mass.

7. The extrusion-molded product according to any one of claims 1 to 6, wherein each of the first adhesive layer and the second adhesive layer contains an acid-modified polyethylene resin.

8. The extrusion-molded product according to claim 7, wherein the acid-modified polyethylene resin is a maleic anhydride-modified polyethylene resin.

9. The extrusion-molded product according to any one of claims 1 to 8, wherein the intermediate layer contains a resin having gas barrier properties.

10. The extrusion-molded product according to claim 9, wherein the resin is an ethylene-vinyl alcohol copolymer resin.

11. An extrusion-molded product according to any one of claims 1 to 10, and one or more layers provided on the extrusion-molded product A molded product for a tube container comprising.

12. A container body including an extrusion-molded product according to any one of claims 1 to 10 with one end sealed or a molded product according to claim 11 with one end sealed, and a cap fitting portion joined to the other end of the extrusion-molded product with one end sealed or the molded product with one end sealed A tube container comprising.

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