Stoppered caps and containers with lids

Abstract

To provide a plug-in type cap having a high capping intensity.SOLUTION: A plug-in type cap made of resin includes linear low-density polyethylene resin and high-density polyethylene resin, where contents of the high-density polyethylene resin with respect to total amounts of resin included in the plug-in type cap is 50 mass% or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a stopper cap and a container with a lid. [Background technology]

[0002] Lids made of polyethylene resin are widely used as caps (lids) to be fitted onto the mouths of containers that contain liquid or liquid-like contents (for example, Patent Document 1). As polyethylene resins, linear low-density polyethylene resin (LLDPE) is widely used as the base resin, and polyethylene resins in which part of the LLDPE is replaced with other polyethylene resins such as high-density polyethylene resin (HDPE) and low-density polyethylene resin (LDPE) are also known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 02-187440 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, a resin cap that uses linear low-density polyethylene resin as the base resin has the advantage of being flexible and can be fitted to the mouth of a container with little force (i.e., low plugging strength), but it also has the disadvantage of being prone to coming off easily. As a result, the cap may come off unintentionally when the internal pressure of the container increases, causing the contents to leak or dry out.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a stopper-type cap with high stoppering strength, and a lidded container having such a stopper-type cap. [Means for solving the problem]

[0006] The stoppered cap of the present invention is made of resin and contains a linear low-density polyethylene resin and a high-density polyethylene resin, and the content of the high-density polyethylene resin relative to the total amount of resin contained in the stoppered cap is 50 mass% or more.

[0007] It is preferable that the content of the high-density polyethylene resin relative to the total amount of resin contained in the stopper type cap is 70% by mass or more.

[0008] The content of the linear low-density polyethylene resin relative to the total amount of resin contained in the stoppered cap is preferably 5 to 30% by mass.

[0009] The melt flow rate of the high-density polyethylene resin at 190° C. and 2.16 kg is preferably 6 g / 10 min or more.

[0010] The high-density polyethylene resin preferably has a flexural modulus of 1000 MPa or more.

[0011] The high-density polyethylene resin is preferably a biomass-derived polyethylene resin.

[0012] It is preferable that the stoppering cap has a male thread portion that can be screwed onto the outer lid.

[0013] The lidded container of the present invention comprises a resin container and a cap fitted onto the opening of the container, the cap being the stoppered cap.

[0014] The resin container preferably contains polyethylene terephthalate.

[0015] The polyethylene terephthalate preferably includes biomass-derived polyethylene terephthalate. [Effects of the Invention]

[0016] According to the present invention, a stopper type cap having high stoppering strength can be provided. Also, according to the present invention, a container with a lid having such a stopper type cap can be provided. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view of a stopper cap according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The cap of this embodiment is made of resin and contains a linear low-density polyethylene resin and a high-density polyethylene resin, with the high-density polyethylene resin content being 50% by mass or more of the total amount of resin contained in the cap. Because this cap has high plugging strength, it is difficult to remove once it is fitted onto the mouth of a container, preventing leakage of the contents due to internal pressure of the container, etc.

[0019] The content of the high-density polyethylene resin relative to the total amount of resin contained in the stopper cap may be greater than 50% by mass, 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, or 80% by mass or more, and may be 95% by mass or less, or 90% by mass or less. For example, the content of the high-density polyethylene resin relative to the total amount of resin contained in the stopper cap may be greater than 50% by mass and 95% by mass or less, or may be 60 to 90% by mass. Because the stopper cap has a high-density polyethylene resin content of greater than 50% by mass relative to the total amount of resin contained in the stopper cap, the stopper cap has higher stoppering strength and is less likely to come off the opening of a container when stoppered, compared to stopper caps made of polyethylene resins other than high-density polyethylene resin.

[0020] In this specification, the high density polyethylene resin is a polyethylene resin having a density of 0.942 g / cm as defined in JIS K6748:1995. 3The high-density polyethylene resin may be either a homopolymer of ethylene or a copolymer of ethylene and an olefin compound. The density of the high-density polyethylene resin is 0.948 to 0.970 g / cm 3 and 0.952 to 0.965 g / cm 3 The density of the high-density polyethylene resin can be measured by the method of ASTM D 792 or JIS K6922-1 or 2, or a method based thereon.

[0021] Examples of the olefin compound include α-olefins such as 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, etc. The content of structural units derived from the olefin compound in the high-density polyethylene resin may be 15% by mass or less, 10% by mass or less, or 1 to 8% by mass.

[0022] The melt flow rate (MFR) of the high-density polyethylene resin at 190°C and 2.16 kg may be 6 g / 10 min or more, 7 g / 10 min or more, 10 to 30 g / 10 min or more, or 15 to 25 g / 10 min or more. The MFR of the high-density polyethylene resin can be measured by the method of ASTM D1238 or JIS K6922-2 or a method based thereon.

[0023] The flexural modulus of the high-density polyethylene resin may be 1000 MPa or more, 1100 MPa or more, or 1200 MPa or more. The flexural modulus of the high-density polyethylene resin can be measured by the method of ASTM D2240 or JIS K6922-2 or a method based thereon.

[0024] The breaking elongation of the high-density polyethylene resin may be 20% or less, 3 to 15%, or 5 to 10%. The breaking strength of the high-density polyethylene resin may be 5 to 50 MPa, or 15 to 35 MPa. The breaking elongation and breaking strength of the high-density polyethylene resin can be measured by the method of ASTM D638 or a method based thereon.

[0025] The Shore D hardness of the high-density polyethylene resin may be 50 or more, may be 55 to 80, or may be 58 to 75. The Shore D hardness of the high-density polyethylene resin can be measured by the method of ASTM D2240 or JIS K 7215, or a method based thereon.

[0026] The Izod impact strength of the high-density polyethylene resin may be 10 J / m or more, and may be 15 to 40 J / m. The Izod impact strength of the high-density polyethylene resin can be measured by the method of ASTM D256 or a method based thereon.

[0027] The deflection temperature under load of the high-density polyethylene resin at 0.455 MPa may be 55° C. or higher, 60 to 80° C., or 65 to 75° C. The deflection temperature under load of the high-density polyethylene resin at 0.455 MPa can be measured by the test method of ASTM D648 or a method based thereon.

[0028] The Vicat softening temperature of the high-density polyethylene resin may be 110° C. or higher, 115 to 130° C., or 120 to 128° C. The Vicat softening temperature of the high-density polyethylene resin can be measured by the method of ASTM D1525 or JIS K7206, or a method based thereon.

[0029] The linear low-density polyethylene resin is not particularly limited, but may be a resin having a density of less than 0.942. The density of the linear low-density polyethylene resin is 0.800 to 0.940 g / cm 3 and 0.820 to 0.935 g / cm 3and 0.880 to 0.930 g / cm 3 and 0.900 to 0.925 g / cm 3 The density of the linear low-density polyethylene resin can be measured by the method of ASTM D1505 or JIS K6922-1, 2, or a method based thereon.

[0030] The flexural modulus of the linear low-density polyethylene resin may be 30 to 700 MPa, 50 to 500 MPa, 60 to 400 MPa, or 65 to 350 MPa. The flexural modulus of the linear low-density polyethylene resin can be measured by the method of JIS K 6922-2 or ASTM D790 or a method based thereon.

[0031] The MFR of the linear low-density polyethylene resin at 190°C and 2.16 kg may be 6 g / 10 min or more, 3 g / 10 min or more, 5 to 30 g / 10 min or more, or 7 to 25 g / 10 min or more. The MFR of the linear low-density polyethylene resin can be measured by the method of ASTM D1238 or JIS K6922-2 or a method based thereon.

[0032] The Vicat softening temperature of the linear low-density polyethylene resin may be 120° C. or less, 60 to 120° C., 63 to 110° C., or 65 to 105° C. The Vicat softening temperature of the linear low-density polyethylene resin can be measured by the method of ASTM D1525 or JIS K7206 or a method based thereon.

[0033] Examples of commercially available linear low-density polyethylene resins include LUMITAC (registered trademark) 43-1 (manufactured by Tosoh Corporation), Novatec (registered trademark) LL UJ580 (manufactured by Japan Polyethylene Co., Ltd.), and UL814 (manufactured by Lotte Chemical Co., Ltd.).

[0034] The stopper cap of this embodiment contains a linear low-density polyethylene resin, which tends to have high stress cracking resistance against contents such as oil. Here, stress cracking resistance refers to the limit stress at which plastic cracks or breaks when left in the contents under a certain stress for a long period of time and then subjected to a load under this condition.

[0035] The content of the linear low-density polyethylene resin relative to the total amount of resin contained in the stopper cap may be 30% by mass or less, 5 to 30% by mass, 10 to 25% by mass, or 13 to 22% by mass. By including the linear low-density polyethylene resin as a resin in the stopper cap, flexibility can be imparted to the stopper cap.

[0036] The polyethylene resin contained in the stopper cap may contain a biomass-derived polyethylene resin (biomass polyethylene resin). The biomass-derived polyethylene resin may be either a high-density polyethylene resin or a low-density polyethylene resin, or may be a high-density polyethylene resin. When the polyethylene resin contains a biomass-derived polyethylene resin, the amount of fossil fuel-derived polyethylene resin used is reduced, thereby reducing the environmental impact.

[0037] Examples of biomass polyethylene resins include plant-derived biomass polyethylene resins. Plant-derived refers to polyethylene resins obtained by polymerizing ethylene synthesized using alcohol obtained by fermenting plants as a raw material. In other words, plant-derived biomass polyethylene resins contain carbon derived from plants. Examples of raw plant materials include, but are not limited to, corn, sugarcane, beet, manioc, and cassava.

[0038] As a high-density polyethylene resin, SHA7260 (manufactured by Braskem, biomass plastic content: 94.5%, density: 0.955 g / cm) is used. 3, MFR: 20 g / 10 min), SHC7260 (manufactured by Braskem, biomass content: 94%, density: 0.959 g / cm 3 Examples of linear low-density polyethylene resins that are biomass polyethylene resins include SLL318 (manufactured by Braskem, biomass content: 87%, density: 0.918 g / cm 3 Examples of low-density polyethylene resins that are biomass polyethylene resins include SBC818 (manufactured by Braskem, biomass content: 95%, density: 0.918 g / cm 3 , MFR: 8.3 g / 10 min). The biomass content of the resin can be measured by the method of ASTM D6866. When the high-density polyethylene resin is a biomass-derived polyethylene resin, there is a tendency for the stoppering strength to be further increased and for the open torque to be maintained.

[0039] The biomass content of the entire resin contained in the stopper cap may be 10% or more, 15% or more, or 20% or more.

[0040] The stoppering cap of this embodiment is a cap to be attached to the mouth of a container. The stoppering cap may have an opening. The opening may be a spout such as a nozzle. The stoppering cap may also be an inner stopper for a container. The container is not particularly limited, but may be a resin container. Examples of resins that are the material for the container include polyolefin resins such as polyester resin, polyethylene resin, and polypropylene resin. Examples of contents to be stored in the container include liquid seasonings such as dressings, beverages, etc.

[0041] FIG. 1 is a perspective view showing an example of a stopper type cap 1 according to this embodiment. The stopper type cap 1 has a fitting portion 2 for fitting onto the mouth of a container. The fitting portion 2 has a closure portion 2A that closes the mouth of the container when the stopper type cap is attached, and a flange portion 2B that forms the side wall of the fitting portion 2 and abuts against the mouth of the container when the cap is attached. A male thread portion 3 is provided on the closure portion 2A, and can be threaded onto an outer lid. A pouring tube portion 4 is provided at the center of the upper end of the male thread portion 3, and the contents of the container can be poured from the pouring tube portion 4.

[0042] The stopper cap of this embodiment is formed from a resin composition containing a linear low-density polyethylene resin and a high-density polyethylene resin. The resin composition may contain other resins in addition to the resin composition containing the linear low-density polyethylene resin and the high-density polyethylene resin. Examples of other resins include low-density polyethylene resin. The content of other resins may be 15% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total amount of resins contained in the stopper cap.

[0043] The resin composition may contain various additives, such as antioxidants, tackifiers, fillers, colorants, slipping agents, and various fillers, as needed. The content of the additives in the resin composition may be 15 parts by mass or less, 10 parts by mass or less, or 5 parts by mass or less, per 100 parts by mass of the resin. To reduce the opening torque of the stopper cap, the content of the slipping agent in the resin composition may be 5 parts by mass or less, 0.01 to 3 parts by mass, 0.05 to 2.5 parts by mass, or 0.5 to 2.5 parts by mass. To maintain a high opening torque of the stopper cap, the content of the slipping agent in the resin composition may be 1.5 parts by mass or less, 1 part by mass or less, 0.5 parts by mass or less, 0.3 parts by mass or less, or 0.1 parts by mass or less, per 100 parts by mass of the resin contained in the resin composition. The slipping agent preferably contains silicone, and may contain both the resin and silicone filled in the resin.

[0044] The container to which the stoppered cap of this embodiment is attached is not particularly limited, and may be made of resin, glass, or the like, and may be a resin container. In other words, the lidded container of this embodiment may have a container and a cap attached to the opening of the container. Examples of resins contained in the container include polyester resins such as polyethylene terephthalate (PET) and polyethylene resins. From the viewpoint of mechanical strength, it is preferable that the resin contains PET. The polyethylene terephthalate resin may be a biomass-derived polyethylene terephthalate resin, or a combination of biomass-derived and petroleum-derived polyethylene terephthalate resins may be used. Examples of PET include fossil fuel-derived PET and plant-derived PET. These can be used alone or in combination of two or more. When the PET contains plant-derived PET, it is possible to prevent a decrease in the mechanical strength and deterioration of the appearance of the bottle. When the PET contains plant-derived PET, the amount of fossil fuel-derived PET used is reduced, thereby reducing the environmental impact.

[0045] This embodiment also provides a combination product comprising a container and the stoppered cap attached to the mouth of the container. The combination product may further include an outer lid that covers the stoppered cap. The outer lid may be attached to the container, and if the stoppered cap has a male threaded portion, the outer lid may be threaded onto the stoppered cap via a female threaded portion that can be threaded onto the male threaded portion. The outer lid may be made of resin. The resin contained in the outer lid is not particularly limited, but may be a thermoplastic resin, a polyolefin resin, at least one of a polypropylene resin and a polyethylene resin, or a mixture of a polypropylene resin and a polyethylene resin. The polyethylene resin may be a biomass-derived polyethylene resin or a high-density polyethylene resin. [Example]

[0046] (Making the cap) A resin composition was prepared by mixing linear low-density polyethylene resin (LLDPE) and high-density polyethylene resin (HDPE) according to the composition shown in Table 1, and the resin composition was extrusion-molded to produce a stoppered cap having the shape shown in Figure 1. The abbreviations in Table 1 represent the following: The biomass degree in Table 1 is the biomass degree of the entire stoppered cap. SHA7260: Biomass high-density polyethylene resin UL814: Linear low-density polyethylene resin 43-1: LUMITAC® 43-1, a linear low-density polyethylene resin UJ580: Novatec® LL UJ580, a linear low-density polyethylene resin Colorant: TET29780 (cream), manufactured by Toyo Ink Co., Ltd. ML-950: Silicone masterbatch, manufactured by Hexa Chemical Co., Ltd.

[0047] (Cocking strength) The stoppering strength was measured using a compression tester (Shimadzu Corporation, Model: Autograph AGS-X 5kN). Specifically, each stoppering cap of the Examples and Comparative Examples was placed on the mouth of a polyethylene terephthalate bottle, a jig was placed over the stoppering cap, and the maximum test force (N) was measured when the stoppering cap was pressed into the jig using the compression tester. Measurements were conducted on 16 samples for each Example and Comparative Example, and the average value was taken as the stoppering strength. The results are shown in Table 1. The measurement conditions were a descending speed of 10 mm / min and a bottle distortion in the compression direction of 3.5 mm. The bottles were formed from a resin composition obtained by mixing biomass-derived PET (trade name "PAPET BIO BCB80", manufactured by Lotte Chemical Co., Ltd.) and a green-colored masterbatch (trade name "PT-RM-SAB 16C2125 TGN", manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) in a mass ratio of 95.2:4.8.

[0048] (opening torque) A stopper-type cap was attached to the mouth of a bottle, and a resin outer cap was then attached to the resulting bottle with an inner stopper. The outer cap was attached by screwing the female thread of the outer cap onto the male thread of the stopper-type cap. The opening torque of the bottle with the outer cap attached was measured using a digital torque meter (manufactured by Tohnichi Manufacturing Co., Ltd., model: 2TME1000CN2). The opening torque is the maximum torque value in each measurement. Measurements were conducted on 16 samples for each example and comparative example, and the average value was taken as the opening torque. The results are shown in Table 1. The outer cap was formed from a resin composition containing polypropylene resin and biomass high-density polyethylene resin.

[0049] [Table 1]

[0050] As is clear from a comparison between Examples 1 to 3 and Comparative Examples 1 and 2, the cap of the present embodiment had excellent capping strength. Therefore, the cap is less likely to come off the container, and displacement of the cap due to swelling pressure of the contents, etc., can be suppressed. Furthermore, a comparison between Examples 1 and 2 and Comparative Examples 1 and 2 shows that Examples 1 and 2 maintain sufficient opening torque, and are able to sufficiently prevent the outer lid from coming off due to vibrations during transportation, etc. Furthermore, in applications where ease of opening is important, the addition of a sliding material, as in Example 3, can significantly reduce the opening torque while maintaining the capping strength. [Explanation of symbols]

[0051] 1...stopper cap, 2...fitting portion, 2A...closure portion, 2B...flange portion, 3...male thread portion, 4...pouring tube portion.

Claims

1. A resin stopper-type cap, A linear low-density polyethylene resin and a high-density polyethylene resin are included, The content of the high-density polyethylene resin relative to the total amount of resin contained in the stopper cap is 50% by mass or more, A stopperable cap, wherein the content of the linear low-density polyethylene resin relative to the total amount of resin contained in the stopperable cap is 5 to 30 mass %.

2. 2. The stopper cap according to claim 1, wherein a content of the high-density polyethylene resin relative to a total amount of resin contained in the stopper cap is 70% by mass or more.

3. A stopper cap as described in claim 1, wherein the content of the high-density polyethylene resin relative to the total amount of resin contained in the stopper cap is 70 mass% or more, and the high-density polyethylene resin is a high-density polyethylene resin derived from biomass.

4. The stopper cap according to any one of claims 1 to 3, wherein the high-density polyethylene resin has a melt flow rate of 6 g / 10 min or more at 190°C and 2.16 kg.

5. The stopper cap according to any one of claims 1 to 4, wherein the high-density polyethylene resin has a flexural modulus of 1000 MPa or more.

6. 2. The stopper cap according to claim 1, wherein the high-density polyethylene resin is a biomass-derived high-density polyethylene resin.

7. The stopper cap according to any one of claims 1 to 6, having a male thread portion that can be threadably engaged with the outer lid.

8. A resin container and a cap attached to the opening of the container, A container with a lid, wherein the cap is a stopper-type cap according to any one of claims 1 to 7.

9. The container with lid according to claim 8 , wherein the resin container contains polyethylene terephthalate.

10. 10. The container with lid of claim 9, wherein the polyethylene terephthalate comprises biomass-derived polyethylene terephthalate.

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