plastic containers

Abstract

To provide a plastic container excellent in a glide-down property and high in a long-lasting glide-down property.SOLUTION: There is provided a plastic container for storing a content. The innermost layer in contact with the content is composed of a resin composition formed by adding silicone and oleic acid amid or an emulsifier to a polyolefin resin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a plastic container. [Background technology]

[0002] Containers whose inner surface is made of a polyolefin resin are commonly used to store contents such as seasonings. Such containers are required to have a sliding property that allows the contents to quickly fall down the inner surface of the container so that the contents can be used up without loss. Patent Document 1 discloses a plastic container whose sliding property is improved by adding an unsaturated aliphatic amide and a saturated aliphatic amide as a lubricant to the polyolefin resin that constitutes the innermost layer of the plastic container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-214914 Public Relations Summary of the Invention [Problem to be solved by the invention]

[0004] However, even if the sliding property of a plastic container is good immediately after filling it with contents, it may deteriorate over the course of storage. Therefore, there is a demand for a plastic container that has long-lasting sliding property and that does not deteriorate much even after long-term storage.

[0005] The present invention has been made in consideration of the above circumstances, and provides a plastic container for storing contents such as condiments such as sauces and mayonnaise, which has excellent sliding properties and long-lasting sliding properties. [Means for solving the problem]

[0006] According to the present invention, there is provided a plastic container for storing contents, characterized in that the innermost layer that comes into contact with the contents is made of a resin composition in which silicone and oleic acid amide or an emulsifier are added to a polyolefin resin. [Effects of the Invention]

[0007] The inventors discovered that by constructing the innermost layer that comes into contact with the contents from a resin composition in which silicone and oleic acid amide or an emulsifier have been added to a polyolefin resin, the container exhibits excellent sliding properties when the contents are placed inside, and that there is little decrease in sliding properties even after long-term storage of more than 20 days, leading to the completion of the present invention.

[0008] Various embodiments of the present invention will be described below as examples, and the embodiments shown below can be combined with each other. Preferably, the emulsifier is a glycerin fatty acid ester. Preferably, the emulsifier is a diglycerin fatty acid ester. Preferably, the polyolefin resin is polypropylene. Preferably, the polyolefin resin is low-density polyethylene. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view of a plastic container 1 according to an embodiment of the present invention. [Figure 2] 1 is a diagram showing an example of the layer structure of a container body 2 of a plastic container 1. FIG. [Figure 3] 1 is a diagram showing another example of the layer structure of the container body 2 of the plastic container 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The features shown in the following embodiments can be combined with each other. Furthermore, each feature can be an invention independently.

[0011] 1. Plastic container composition FIG. 1 is a diagram showing an example of the configuration of a plastic container 1 according to an embodiment of the present invention. While the contents housed in the plastic container 1 are not particularly limited, the plastic container 1 is particularly suitable for housing aqueous contents. In the present invention, aqueous contents refer to contents having a water content of 30% by mass or more and a lipid content of less than 20% by mass, such as Worcestershire sauce, medium-thick sauce, and thick sauce. The plastic container 1 exhibits particularly excellent sliding properties and long-lasting sliding properties for the above-mentioned aqueous contents, and particularly for relatively viscous contents having a water content of 50% by mass or more and a lipid content of less than 20% by mass and a viscosity of 150 mPa·s or more, and the sliding properties are long-lasting.

[0012] A plastic container 1 according to an embodiment of the present invention comprises a container body 2 and a cap 3. The container body 2 comprises a storage section 21 for storing contents, and a mouth section 22 having an opening for discharging the contents from the storage section 21.

[0013] The cap 3 includes a cap body 32 and a cap cover 31. The cap body 32 and the cap cover 31 are connected at a connecting portion 33, allowing the cap cover 31 to be opened and closed. The cap body 32 includes an upper portion 32a, a discharge port 32b provided in the upper portion 32a, and a cylindrical portion 32c extending cylindrically from the outer periphery of the upper portion 32a.

[0014] An engaging portion (not shown) that can engage with the outer surface of the mouth portion 22 is formed on the inner surface of the cylindrical portion 32c, and by plugging the cap 3 onto the mouth portion 22 from above, the engaging portion engages with the outer surface of the mouth portion 22, and the cap 3 is attached to the container body 2. Note that the method of attaching the cap 3 to the container body 2 is not limited to the plugging method described above, and may be a screw method.

[0015] 2 is a diagram showing an example of the layer structure of the container body 2. The container body 2 has a multilayer structure including, from the inside out, an innermost layer 4, an intermediate layer 5, an adhesive resin layer 6, a barrier layer 7, an adhesive resin layer 8, and an outermost layer 9. The thickness ratios of the layers are, for example, as follows: Innermost layer 4: 10-40% Middle class 5: 30-60% Adhesive resin layer 6:1~10% Barrier layer 7: 5-10% Adhesive resin layer 8:1~15% Outermost layer 9: 20~60% Each layer will be described below.

[0016] (innermost layer 4) The innermost layer 4 is the layer that comes into contact with the contents and is composed of a resin composition containing a polyolefin-based resin. Examples of polyolefin-based resins include polyethylenes such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), as well as polypropylene (PP), poly-1-butene, and poly-4-methyl-1-pentene. The polyolefin-based resin may also be a random or block copolymer of α-olefins such as ethylene, propylene, 1-butene, or 4-methyl-1-pentene, or may be a so-called cyclic olefin resin (cycloolefin polymer (COP)) or a copolymer of a cyclic olefin and an α-olefin (a chain olefin), such as a so-called cyclic olefin copolymer (cycloolefin copolymer (COC)). These polyolefin-based resins may be used alone or in combination of two or more.

[0017] Among the polyolefin resins exemplified above, polyethylene or polypropylene is preferably used, and polyethylene or polypropylene is preferably used as the main component of the resin, i.e., it is preferably used in an amount of 50 mass% or more of the entire resin composition. As the polyethylene, low-density polyethylene or linear low-density polyethylene is preferably used in consideration of transparency, squeezability, etc.

[0018] Silicone (including silicone compounds) is added to the polyolefin resin as a lubricant. The addition of silicone improves the sliding properties of the innermost layer 4. Examples of the silicone to be added include organopolysiloxane (polyorganosiloxane), and those with a linear or partially branched molecular structure can be used. Among organopolysiloxanes, it is preferable to use diorganopolysiloxane.

[0019] Examples of silicon-bonded organic groups in diorganopolysiloxanes include alkyl groups such as methyl, ethyl, propyl, 3-chloropropyl, and 3,3,3-trifluoropropyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl, tolyl, and xylyl; aralkyl groups such as benzyl, phenethyl, and 3-phenylpropyl; and alkenyl groups such as vinyl, propenyl, butenyl, and hexenyl. Of these, alkyl groups, particularly methyl groups, are preferred. Hydroxyl groups or alkoxy groups may be bonded to the terminals of the diorganopolysiloxane. Examples of such diorganopolysiloxanes include dimethylpolysiloxanes capped at both ends with trimethylsiloxy groups, dimethylpolysiloxanes capped at both ends with silanol groups, dimethylpolysiloxanes capped at one end with a silanol group and the other end with a trimethylsiloxy group, methylphenylpolysiloxanes capped at both ends with trimethylsiloxy groups, dimethylsiloxane / methylvinylsiloxane copolymers capped at both ends with trimethylsiloxy groups, dimethylpolysiloxanes capped at both ends with dimethylvinylsiloxy groups, dimethylsiloxane / methylphenylsiloxane copolymers capped at both ends with trimethylsiloxy groups, and dimethylsiloxane / methyl(3,3,3-trifluoropropyl)siloxane copolymers capped at both ends with trimethylsiloxy groups. These may be used alone or in combination of two or more.

[0020] The weight-average molecular weight (Mw) of the silicone is preferably 1 million (1,000,000) or more, more preferably 1 million (1,000,000) to 10 million (10,000,000), even more preferably 1.5 million (1,500,000) to 10 million (10,000,000), and particularly preferably 5 million (5,000,000) to 10 million (10,000,000). When the weight-average molecular weight of the silicone is within the above range, the silicone is less likely to bleed out and can maintain good sliding properties without migrating into the contents. The weight-average molecular weight can be measured by a conventionally known method such as gel filtration chromatography.

[0021] The viscosity of the silicone is preferably 6,000,000 (6,000,000) cS or more, and particularly preferably 6,000,000 (6,000,000) to 10,000,000 (10,000,000) cS.

[0022] The amount of silicone added is preferably 2.5 to 10.0% by mass, more preferably 5 to 10% by mass, and particularly preferably 8 to 10% by mass, based on the total resin composition constituting the innermost layer 4. By setting the amount of lubricant added within this range, good sliding properties are exhibited, while problems such as reduced moldability and clouding of the resin composition caused by adding too much silicone are unlikely to occur. Silicone may also be added using a masterbatch (MB) mixed with a base resin made of a polyolefin resin such as polyethylene or polypropylene, or other resin. In this case, the silicone content can be adjusted to fall within the above range depending on the blending ratio of the masterbatch to the silicone (typically 10 to 70% by mass of silicone relative to the total masterbatch). (As a rough guide, the masterbatch is preferably added in an amount of 0.01 to 20% by mass, and particularly preferably 0.5 to 8.0% by mass, based on the total resin composition constituting the innermost layer 4, but is not particularly limited to these ranges.)

[0023] Oleic acid amide or an emulsifier is further added to the polyolefin resin constituting the innermost layer 4. By using oleic acid amide in combination with silicone, the durability of the sliding properties is improved, and the sliding properties of the innermost layer 4 are less likely to decrease even after long-term storage. The amount of oleic acid amide added is not particularly limited, but is preferably 0.01 to 10 mass % and more preferably 0.1 to 5 mass % of the total resin composition constituting the innermost layer 4.

[0024] By using an emulsifier in combination with silicone, the slipperiness of the innermost layer 4 due to the addition of silicone is less likely to decrease even after long-term storage. Examples of emulsifiers include polyhydric alcohol fatty acid esters, and among polyhydric alcohol fatty acid esters, it is preferable to use glycerin fatty acid esters, polyglycerin fatty acid esters, or sorbitan fatty acid esters. Examples of glycerin fatty acid esters include glycerin monodibehenate (HLB value 4.2), glycerin mono-12-hydroxystearate (HLB value 3.4), and glycerin monobehenate (HLB value 2.8). Examples of polyglycerol fatty acid esters include diglycerol fatty acid esters such as diglycerol oleate (HLB value 5.7), diglycerol stearate (HLB value 5.7), diglycerol laurate (HLB value 7.3), and diglycerol monolaurate (HLB value 9.4), as well as decaglycerol stearate (HLB value 12), decaglycerol laurate (HLB value 15.5), and polyglycerol polyricinoleate (HLB value 0.5). Examples of sorbitan fatty acid esters include sorbitan stearate (HLB value 5.4).

[0025] Among the above-mentioned exemplified substances, it is preferable to use glycerin fatty acid esters or diglycerin fatty acid esters, and it is more preferable to use diglycerin fatty acid esters. Furthermore, it is particularly preferable to use diglycerin oleate or diglycerin laurate as the diglycerin fatty acid ester. Furthermore, a combination of different types of emulsifiers may be used. The amount of emulsifier added is not particularly limited, but is preferably 0.1 to 5.0% by mass, and more preferably 0.3 to 1.0% by mass, of the total resin composition constituting the innermost layer 4.

[0026] Furthermore, the polyolefin resin constituting the innermost layer 4 may contain both oleic acid amide and an emulsifier in addition to silicone.

[0027] (outermost layer 9) The outermost layer 9 is the layer disposed on the outermost side of the container body 2, and is composed of a resin composition containing a polyolefin-based resin. The preferred polyolefin-based resin is the same as that of the innermost layer 4, and it is more preferred that the polyolefin-based resins constituting the innermost layer 4 and the outermost layer 9 are the same.

[0028] It is preferable to add a fatty acid amide as a lubricant to the polyolefin resin. The addition of a fatty acid amide enables the plastic container 1 to exhibit slip properties in response to various environmental temperatures in each process, from molding to filling, transferring, and packaging of the contents, thereby eliminating problems such as poor slipperiness on the surface of the plastic container 1 in each process. For the outermost layer 9, it is preferable to use a resin composition in which a lubricant (particularly a fatty acid amide-based lubricant, described below) is added to, mixed with, and kneaded into the polyolefin resin in order to impart slipperiness to, for example, a food filling line or the like that is mainly made of metal materials such as stainless steel.

[0029] As the fatty acid amide, saturated fatty acid amides or unsaturated fatty acid amides can be used. Examples of saturated fatty acid amides include butylamide, hexylamide, decylamide, lauric acid amide, myristic acid amide, palmitic acid amide, and stearic acid amide. Among these saturated fatty acid amides, stearic acid amide is preferably used. These saturated fatty acid amides may be used alone or in combination of two or more.

[0030] Examples of unsaturated fatty acid amides include acrylamide, methacrylamide, crotonamide, isocrotonamide, undecylenic acid amide, cetoleic acid amide, oleic acid amide, erucic acid amide, ethylene bisoleic acid amide, oleyl palmitamide, stearyl erucamide, linoleic acid amide, linolenic acid amide, and arachidonic acid amide. Among these, those having 14 to 24 carbon atoms, such as cetoleic acid amide, oleic acid amide, erucic acid amide, linoleic acid amide, linolenic acid amide, and arachidonic acid amide, are preferred, with oleic acid amide being particularly preferred. These unsaturated fatty acid amides may be used alone or in combination of two or more.

[0031] The content of the fatty acid amide in the outermost layer 9 is preferably 0.01 to 10% by mass based on the entire resin composition constituting the outermost layer 9. By setting the amount of fatty acid amide added within the above range, good slip properties can be exhibited. The content of the fatty acid amide is particularly preferably 0.1 to 5% by mass based on the entire resin composition constituting the outermost layer 9.

[0032] (Middle Class 5) The intermediate layer 5 is a layer disposed between the innermost layer 4 and the outermost layer 9, and is composed of a resin composition containing a thermoplastic resin. The intermediate layer 5 is preferably composed of a resin composition containing a recycled material obtained by recycling scrap generated during the molding of the plastic container 1. Because the scrap contains all layers of the plastic container 1, the recycled material is a mixture of the resin compositions that make up each layer.

[0033] The resin composition constituting the mid layer 5 is preferably a mixture of a recycled material and a virgin thermoplastic resin. In this case, from the viewpoint of maintaining moldability and recycling resources, the amount of recycled material is preferably about 10 to 60 parts by weight per 100 parts by weight of the virgin thermoplastic resin (for example, the polyolefin resin of the innermost layer 4 or the outermost layer 9).

[0034] (Barrier layer 7) The barrier layer 7 is a layer disposed between the innermost layer 4 and the outermost layer 9, and is made of a resin with high gas barrier properties. Examples of such resins include ethylene vinyl alcohol copolymer (EVOH: saponified ethylene vinyl acetate copolymer, etc.) and aromatic polyamide. By providing the barrier layer 7, oxidative deterioration of the contents due to oxygen permeation can be effectively suppressed.

[0035] The barrier layer 7 may be disposed between the intermediate layer 5 and the outermost layer 9 as shown in Fig. 2, or between the innermost layer 4 and the intermediate layer 5 as shown in Fig. 3. When the barrier layer 7 is disposed between the intermediate layer 5 and the outermost layer 9, that is, closer to the outermost layer 9 than the intermediate layer 5, an increase in the relative humidity of the barrier layer 7 due to moisture in the contents is suppressed. Since the oxygen transmission rate of EVOH increases as the relative humidity increases, by disposing the barrier layer 7 closer to the outermost layer 9 than the intermediate layer 5, an increase in the oxygen transmission rate can be suppressed.

[0036] (Adhesive resin layer 6,8) The adhesive resin layers 6, 8 are composed of an adhesive resin. Examples of adhesive resins include acid-modified polyolefin resins (e.g., maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene). The adhesive resin layers 6, 8 improve the adhesion between the barrier layer 7 and the innermost layer 4, the intermediate layer 5, or the outermost layer 9. Instead of providing the adhesive resin layers 6, 8, an adhesive resin may be blended into the barrier layer 7.

[0037] In addition, various additives generally used in the field of resin materials, such as plasticizers, antistatic agents, antioxidants, antifogging agents, ultraviolet absorbers, heat stabilizers, nucleating agents, release agents, colorants, and neutralizing agents, may be added to each of the above-mentioned layers within a range that does not impair the object and effect of the present invention.

[0038] 2. Manufacturing method of plastic container 1 The plastic container 1 can be formed by blow molding a parison. Blow molding may be direct blow molding or injection blow molding. In direct blow molding, a molten cylindrical parison extruded from an extruder is sandwiched between a pair of split molds and air is blown into the parison to produce the plastic container 1. In injection blow molding, a test-tube-shaped parison with a bottom, called a preform, is formed by injection molding, and this parison is used to perform blow molding.

[0039] In either blow molding method, the layer structure of the parison is the same as the layer structure of the plastic container 1. A multi-layer parison can be formed by co-extrusion molding, multi-layer injection molding, or the like. [Example]

[0040] 1. Sample Preparation A plastic container 1 (capacity: 500 ml) was manufactured having the shape shown in Fig. 1 and a layer structure including, from the inside out, an innermost layer 4, an adhesive resin layer 6, a barrier layer 7, an adhesive resin layer 8, an intermediate layer 5, and an outermost layer 9 as shown in Fig. 3. The plastic container 1 was manufactured by forming the container body 2 by blow molding and the cap 3 by injection molding.

[0041] [Table 1]

[0042] As the polyolefin resin contained in the resin composition of the innermost layer 4, polypropylene (PP) was used in Examples 1 and 2 and Comparative Examples 1 and 2, and low-density polyethylene (LDPE) was used in Examples 3 to 5 and Comparative Examples 3 to 5. Specifically, the following were used. Examples 1 and 2, Comparative Examples 1 and 2: Noblen (registered trademark) FSX16E9, manufactured by Sumitomo Chemical Co., Ltd. Examples 3 to 5 and Comparative Examples 3 to 5: Suntec (registered trademark) M2206 manufactured by Asahi Kasei Corporation

[0043] Silicone was added to the innermost layer 4 using a masterbatch in which silicone and a base resin (polypropylene in Examples 1 and 2 and Comparative Examples 1 and 2, and low-density polyethylene in Examples 3 to 5 and Comparative Examples 3 to 5) were blended in a ratio of 50% by mass:50% by mass. The amount of silicone added was 0.5% by mass with respect to the entire resin composition constituting the innermost layer 4. The silicone used had a weight-average molecular weight (Mw) of 1,000,000 or more and a viscosity of 6,000,000 cS or more. Specifically, the following masterbatch was used. Examples 1 and 2, Comparative Examples 1 and 2: ML-950 manufactured by Hexa Chemical Co., Ltd. Examples 3 to 5 and Comparative Examples 3 to 5: ML-950 manufactured by Hexa Chemical Co., Ltd.

[0044] In Examples 3 to 5 and Comparative Example 2, oleic acid amide was added to the innermost layer 4, and in Comparative Example 4, erucic acid amide was added to the innermost layer 4 using a masterbatch in which a base resin (low-density polyethylene in Examples 3 to 5 and Comparative Example 4, and polypropylene in Comparative Example 2) and oleic acid amide or erucic acid amide were blended in a predetermined ratio. Specifically, the following was used. Examples 3 to 5: A-10 (1.7% oleamide masterbatch), manufactured by Sumitomo Chemical Co., Ltd. Comparative Example 2: MS02 (5% oleic acid amide masterbatch), manufactured by Sumitomo Chemical Co., Ltd. Comparative Example 4: ESQ-4 (4% erucamide masterbatch) manufactured by Prime Polymer Co., Ltd.

[0045] In Examples 1 and 4, diglycerin laurate was added as an emulsifier to the innermost layer 4, and in Examples 2 and 5 and Comparative Example 5, diglycerin oleate was added. Specifically, the following were used. Examples 1 and 4: Rikemal L-71-D, manufactured by Riken Vitamin Co., Ltd. Examples 2 and 5, Comparative Example 5: Rikemal O-71-D(E), manufactured by Riken Vitamin Co., Ltd.

[0046] In all Examples and Comparative Examples, low-density polyethylene was used as the polyolefin resin constituting the outermost layer 9. Specifically, Suntec (registered trademark) F2206 manufactured by Asahi Kasei Corporation was used.

[0047] The intermediate layer 5 was made of a mixture of recycled material obtained by recycling scraps generated during the molding of the plastic container 1 and the polyolefin resin that constitutes the outermost layer 9.

[0048] In all examples and comparative examples, an ethylene vinyl alcohol copolymer (SF7503B, manufactured by Mitsubishi Chemical Corporation) was used as the resin constituting the barrier layer 7.

[0049] The adhesive resin layer 6 was formed using the following adhesive resin. Examples 1 and 2, Comparative Examples 1 and 2: P674V, manufactured by Mitsubishi Chemical Corporation Examples 3 to 5 and Comparative Examples 3 to 5: Modic (registered trademark) L522, manufactured by Mitsubishi Chemical Corporation

[0050] The adhesive resin layer 8 was formed using the following adhesive resin. Examples 1 and 2, Comparative Examples 1 and 2: Modic (registered trademark) L522, manufactured by Mitsubishi Chemical Corporation Examples 3 to 5 and Comparative Examples 3 to 5: Modic (registered trademark) L522, manufactured by Mitsubishi Chemical Corporation

[0051] 2. Evaluation 2.1.Slip-off test First, a sliding test was conducted on the manufactured plastic container 1. Okonomiyaki sauce (manufactured by Otafuku Sauce Co., Ltd., moisture content: approximately 60%, viscosity: 840 mPa·s (23°C), ingredients: vegetables, fruits, spices, etc.), which is classified as a Worcestershire sauce, was filled to approximately one-third of the plastic container's capacity, and the cap 3 was attached. The plastic container 1 was rotated and inverted (with the cap 3 positioned vertically below the container body 2) to allow the contents to adhere to the entire inner surface of the container body 2 and move most of the contents toward the opening 22. The plastic container 1 was then left standing in an upright position (with the cap 3 positioned vertically above the container body 2), and the sliding of the contents was observed. The contents adhering to the inner surface of the portion of the container body 2 that was not filled with the contents in the upright position were visually inspected, and the time t [h] until it was confirmed that the contents were free of adhesion to at least 80% of the inner surface was measured. The measurement results were evaluated based on the following criteria, and the results are shown in Table 1. A:t≦1[h] B:1[h] <t≦3[h] C:3[h] <t

[0052] 2.2. Storage test After the above-described sliding property test, a storage test was conducted to evaluate the durability of sliding property. The plastic container 1 was rotated or otherwise coated with the contents to adhere to the entire inner surface of the container body 2, and then the plastic container 1 was left in an inverted position. This operation was performed once a day (i.e., every 24 hours). Immediately before this operation (i.e., 24 hours after the operation on the previous day), the contents adhering to the inner surface of the container body 2 of the plastic container 1, where no contents had been filled, were visually confirmed. If it was confirmed that 80% or more of the inner surface was free of contents, the storage test was continued. If not (if it was visually confirmed that less than 80% of the inner surface was free of contents), the storage test was terminated. The day on which the sliding property test was conducted was designated as day 0, and the number of days until it was confirmed that 80% or more of the inner surface of the unfilled portion of the container body 2 was free of contents was used as an index of the durability of sliding property. The results are shown in Table 1.

[0053] 2.3.Evaluation Results In the sliding property test, equivalent sliding properties were observed in Examples 1 to 5 and Comparative Examples 2 to 4. The sliding property of Comparative Example 5, in which the innermost layer 4 was formed from a resin composition in which only an emulsifier was added to low-density polyethylene, was low. Note that, since the sliding property of Comparative Example 5 was low from the beginning, a subsequent storage test was not conducted.

[0054] In Examples 1 to 5, in which silicone and oleic acid amide and / or an emulsifier were added to the polyolefin resin, improved durability of the sliding properties was observed compared to Comparative Examples 1 to 4. Furthermore, when Example 3, in which oleic acid amide was added as the fatty acid amide, was compared with Comparative Example 4, in which erucic acid amide was added, Example 3 showed improved durability of the sliding properties. [Explanation of symbols]

[0055] 1: plastic container, 2: container body, 3: cap, 4: innermost layer, 5: middle layer, 6: adhesive resin layer, 7: barrier layer, 8: adhesive resin layer, 9: outermost layer, 12: glycerin monolayer, 21: storage section, 22: mouth section, 31: cap cover, 32: cap body, 32a: upper section, 32b: discharge port, 32c: tubular section, 33: connecting section

Claims

1. A plastic container containing an aqueous content, The plastic container has a multi-layer structure including a plurality of layers, the innermost layer that comes into contact with the contents is made of a resin composition in which silicone and oleic acid amide or an emulsifier are added to a polyolefin resin, The emulsifier is a polyhydric alcohol fatty acid ester, The weight average molecular weight of the silicone is 1,000,000 or more, The emulsifier is a diglycerin fatty acid ester, A plastic container (excluding those in which the silicone contains a polyolefin chain), wherein the number of carbon atoms in the fatty acid unit of the diglycerin fatty acid ester is 12 or 18.

2. A plastic container containing an aqueous content, The plastic container has a multi-layer structure including a plurality of layers, The innermost layer that comes into contact with the contents is made of a resin composition in which silicone and an emulsifier are added to a polyolefin resin, The emulsifier is a polyhydric alcohol fatty acid ester, The weight average molecular weight of the silicone is 1,000,000 or more, The emulsifier is a diglycerin fatty acid ester, A plastic container (excluding those in which the silicone contains a polyolefin chain), wherein the number of carbon atoms in the fatty acid unit of the diglycerin fatty acid ester is 12 or 18.

3. A plastic container containing an aqueous content, The plastic container has a multi-layer structure including a plurality of layers, The innermost layer that comes into contact with the contents is made of a resin composition in which silicone and oleic acid amide are added to a polyolefin resin, A plastic container, wherein the weight average molecular weight of the silicone is 1,000,000 or more.

4. The plastic container according to any one of claims 1 to 3, A plastic container, wherein the polyolefin resin is polypropylene.

5. The plastic container according to any one of claims 1 to 3, A plastic container, wherein the polyolefin resin is low-density polyethylene.

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