JP7508753B2 - Liquid seasoning container - Google Patents

Description

The present invention relates to a liquid seasoning-filled container that includes an injection-molded product such as a lid and a hollow-molded product such as a container body.

Traditionally, bento lunches and prepared foods sold at supermarkets and convenience stores have come with liquid seasonings such as soy sauce and sauces filled in liquid seasoning containers. The liquid seasoning containers used are made of thermoplastic resin and have a cap-shaped lid and a colorless, transparent, bottle-shaped container body. The lid and container body come in a variety of sizes and shapes depending on the type and amount of liquid seasoning.

Liquid seasoning containers contain a lubricant to make them slippery, so that the surfaces of adjacent containers do not impede the movement of the containers themselves during manufacturing or transportation, and so that the inner surfaces of each container do not impede the fluidity of the contents (see Patent Documents 1 and 2). Patent Document 2 also discloses that mixing fatty acid amide lubricants with different melting points in a specified ratio makes the container slippery even when the temperature environment changes. This is due to the lubricant migration phenomenon (the behavior of the lubricant rising from the inside to the surface, bleeding), which causes the lubricant to gather near the surface during molding.

Patent No. 2779505 Patent No. 2627127

The lid and the container body are connected by threads on each, and usually the lubricant allows them to slide against each other and open easily. However, if the product is left for a certain period of time in a high temperature environment, such as in summer, the lubricant may re-dissolve within the molded product (single molecules become independent, and the lubricant concentration decreases near the surface), which may cause the threads to stick together (blocking). This can result in the lid not coming off or the container body becoming twisted and damaged.

Generally, the lid is injection molded and the container body is hollow molded, and there is no disclosure of an issue regarding the ease with which the threads of such an injection molded product and hollow molded product slide against each other. In particular, liquid seasoning containers are relatively small for thermoplastic resin containers, and should be designed to be easy to handle with the consumer's fingers, regardless of the season or other external environment. The inventors therefore focused on the lubricants contained in both the injection molded product and the hollow molded product.

Therefore, the object of the present invention is to provide a liquid seasoning-filled container in which an injection molded product and a hollow molded product, which are joined by threads, can be easily separated from each other regardless of the external environment.

That is, the present invention provides a liquid seasoning filling container having an injection-molded product with a screw thread, which contains a first lubricant having a melting point of 100°C or higher and a second lubricant having a melting point of less than 100°C , the first lubricant being an unsaturated higher fatty acid bisamide, and the content of the first lubricant being 500 to 1500 ppm .

That is, the present invention relates to a liquid seasoning filling container having a hollow molded product with a screw thread formed thereon, characterized in that it contains a first lubricant having a melting point of 100°C or higher and a second lubricant having a melting point of less than 100°C , the first lubricant being an unsaturated higher fatty acid bisamide, and the content of the first lubricant being 500 to 1500 ppm .

The unsaturated higher fatty acid bisamide is preferably ethylene bisoleamide (EBO) or ethylene biserucamide (EBE) .

It is also desirable that the pitch of the thread is 2.0 mm or less and the height of the thread is 0.5 mm or more .

In the present invention, the main component is preferably a polyolefin resin .

The content of the second lubricant is preferably 500 to 1000 ppm.

It is also preferable that the liquid seasoning filling container comprises the injection molded product and the hollow molded product, and that the threads of the injection molded product and the hollow molded product face each other.

The liquid seasoning-filled container according to the present invention allows the injection-molded product and the hollow-molded product, which are joined by their threads, to be easily separated from each other regardless of the external environment. In other words, depending on the specifications of the injection-molded product and/or the hollow-molded product, particularly the melting point, molecular weight, type and content of the lubricant contained therein, it is expected that blocking of the threads will be less likely to occur even in high-temperature environments such as summer.

FIG. 2 is a front view of the liquid seasoning filled container according to one embodiment of the present invention. FIG. 2 is a partially enlarged view of the liquid seasoning filling container.

Hereinafter, a liquid seasoning filled container in one embodiment of the present invention (hereinafter, also referred to as "this liquid seasoning filled container") will be described with reference to Figs. 1 and 2.
In addition, in the figure, when there are a plurality of identical parts, only one part is numbered, and the overlapping parts may be omitted. For convenience of explanation, certain parts and leading lines are shown by dashed lines or imaginary lines (two-dot chain lines).

<Overview of liquid seasoning container>
As shown in Fig. 1, the liquid seasoning-filled container T is filled with liquid seasoning for lunch boxes or side dishes, and includes an injection molded product 1 with a female screw thread 11a and a hollow molded product 2 with a male screw thread 21a. The screw thread 11a of the injection molded product 1 and the screw thread 21a of the hollow molded product 2 face each other. In other words, the injection molded product 1 is a cylindrical and concave lid body with a screw thread 11a on the inner side, and the hollow molded product 2 is a container body with a cylindrical protruding part 21 with a screw thread 21a on the outer side and an accommodating part 22 for the liquid seasoning molded integrally with the protruding part 21, which is an injection outlet for the liquid seasoning at its tip and is not numbered, for example, and which is a liquid seasoning such as soy sauce or sauce, or a semi-liquid dressing made by mixing two or more kinds of solid and liquid seasonings and ingredients such as ketchup or mayonnaise.
The injection molded product 1 may be a cap having a hinged or sliding opening and closing part that can be opened and closed freely. The shape of the hollow molded product 2 is not limited, and may be an elongated cylinder, a rectangular parallelepiped, a shape imitating a living thing such as a fish or an animal, a vehicle such as an automobile, a human, a character, etc. The liquid seasoning-filled container T may be completed in a state where the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2 having the liquid seasoning face each other (a state where the lid body is attached to the container body having the liquid seasoning), or may be completed in a state where the injection molded product 1 and the hollow molded product 2 are separate (a state where the lid body and the container body are separated).

<Components of injection molded product 1 and hollow molded product 2>
The injection molded product 1 and the hollow molded product 2 have a single-layer structure mainly composed of a polyethylene resin (PE) or a polypropylene resin (PP). Examples of polyethylene resins include high density polyethylene (HDPE), linear low density polyethylene (LLDPE), metallocene LLDPE, and side-chain branched low density polyethylene (HP-LDPE). If the main components of the injection molded product 1 and the hollow molded product 2 are the same material, blocking between the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2 may easily occur.
The injection molded product 1 and the hollow molded product 2 may have a multi-layer structure and may contain an antioxidant such as a polymer stabilizer to prevent deterioration, or an inorganic material such as aluminum oxide or silicon to prevent deformation. The melt flow rate (MFR) of the polyethylene resin or polypropylene resin may be selected to an optimum value in consideration of moldability, rigidity, and transparency.

<Melting Point of First Lubricant of Injection Molded Product 1 and Hollow Molded Product 2>
The injection molded product 1 and the hollow molded product 2 contain a first lubricant having a melting point of 100° C. to 160° C. If the melting point of the first lubricant is lower than 100° C., blocking between the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2 occurs due to remelting of the first lubricant in a high-temperature environment of 60 to 70° C., and if the melting point is higher than 160° C., uniform dissolution during melt extrusion may not occur, and bleeding may become significantly slow.

<Molecular Weight of First Lubricant for Injection Molded Product 1 and Hollow Molded Product 2>
The molecular weight of the first lubricant is 350 or more, preferably 400 or more, and more preferably 500 or more, with the upper limit being 700. If it is less than 350, the lubricant that has bled out may re-dissolve inside, causing blocking.

<Types of First Lubricant for Injection Molded Product 1 and Hollow Molded Product 2>
The first lubricant may be, for example, a saturated higher fatty acid amide, a saturated higher fatty acid bisamide, an unsaturated higher fatty acid bisamide, or an unsaturated higher fatty amine bisamide, among aliphatic monoamides and aliphatic bisamides belonging to the aliphatic compounds, and is preferably lauric acid amide, behenic acid amide (BA), methylene bisstearic acid amide, ethylene bispalmitic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, or hexamethylene bisoleic acid amide, more preferably stearic acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, or hexamethylene bisoleic acid amide, and more preferably stearic acid amide (SA), ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bisoleic acid amide (EBO), ethylene biserucic acid amide (EBE), N,N'-dioleyl adipamide, or N,N'-dioleyl sebacic acid amide.
The first lubricant may be any suitable one as long as it satisfies the above-mentioned melting point and molecular weight requirements and belongs to the aliphatic compound.

<Content of First Lubricant in Injection Molded Product 1 and Hollow Molded Product 2>
The content of the first lubricant is 200 to 1500 ppm, preferably 500 to 1500 ppm, and more preferably 750 to 1200 ppm. If it is less than 200 ppm, blocking between the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2 may occur due to re-dissolution inside, and if it is more than 1500 ppm, the first lubricant may bleed excessively onto the surface after molding, causing a powdery appearance.

<Second Lubricant for Injection Molded Product 1 and Hollow Molded Product 2>
The injection molded product 1 and the hollow molded product 2 further contain a second lubricant having a melting point of less than 100°C. The second lubricant is less likely to bleed in a room temperature environment of less than 60°C, so the content of the first lubricant can be made smaller than that of the first lubricant alone. In other words, it is expected to achieve a content at which the first lubricant is effective in the high temperature environment and a content at which the second lubricant is effective in the room temperature environment. The second lubricant is, for example, an unsaturated higher fatty acid amide, preferably erucic acid amide, and more preferably oleic acid amide, among aliphatic monoamides and aliphatic bisamides belonging to aliphatic compounds. The content of the second lubricant is 500 to 1000 ppm, more preferably 600 to 900 ppm, and more preferably 700 to 800 ppm.

<Proportions and dimensions of each part of the injection molded product 1 and the hollow molded product 2>
To obtain the effect of this embodiment, as shown in Figure 2, the pitch p of the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2 is 2.0 mm or less, preferably 1.5 mm or less, more preferably 1.0 mm or less, and even more preferably 0.8 mm or less. If it is greater than 2.0 mm, the diameters of the thread 11a and the thread 21a will be relatively large, and the rotational moment applied to the injection molded product 1 will be relatively large, so that the injection molded product 1 will be able to rotate easily even if blocking occurs between the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2.
The height h of the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2 is 0.5 mm or more, preferably 0.65 mm or more, and more preferably 0.8 mm or more. If it is less than 0.5 mm, the contact area between the thread 11a and the thread 21a becomes relatively narrow, so that the rotation moment applied to the injection molded product 1 is relatively small and the injection molded product 1 is easy to rotate even if blocking occurs between the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2. Moreover, the height h is preferably 0.3 to 1.0 mm, and more preferably 0.5 to 0.8 mm.
The outer diameter 1w of the injection molded product 1 is 10 mm or less, preferably 8.5 mm or less, and more preferably 7 mm or less. If the outer diameter 1w is greater than 10 mm, the rotational moment applied to the injection molded product 1 becomes relatively large, and the injection molded product 1 is likely to rotate even if blocking occurs between the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2.
The ratio of the outer diameter 1w of the injection molded product 1 to the outer diameter 22w of the accommodating portion 22 adjacent to the boundary portion 22b between the protrusion 21 and the accommodating portion 22 of the hollow molded product 2 is 1:2.5 or less, preferably 1:1.8 or less, and more preferably 1:1.2 or less. If the ratio is greater than 1:2.5, the stress on the accommodating portion 22 due to the twisting of the protrusion 21 accompanying the rotation of the injection molded product 1 will be relatively large, and the injection molded product 1 will be able to rotate easily even if blocking occurs between the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2.
The pitch p and height h of the thread 11a of the injection molded product 1 and the thread 21a of the hollow molded product 2 may correspond to the size (including thickness, capacity, total length, etc.) of the injection molded product 1 and the hollow molded product 2, including the outer diameter 1w of the injection molded product 1. The thickness of the injection molded product 1 may be 0.5 to 2.0 mm, and preferably 0.8 to 1.2 mm. The thickness of the hollow molded product 2 may be 0.3 to 1.5 mm, and preferably 0.4 to 1.0 mm. There is no limitation on the capacity of the hollow molded product 2, and it may be 50 ml or less, preferably 30 ml or less, and more preferably 10 ml or less. In addition, when the hollow molded product 2 is even smaller, it may be 7 ml or less, preferably 5 ml or less, and more preferably 3 ml or less.

Examples and comparative examples of the present liquid seasoning-filled container will be described with reference to Tables 1 and 2.
The tests in the Examples and Comparative Examples (hereinafter also referred to as "main tests") employ an injection molded product (lid) and a hollow molded product (container body) of predetermined specifications, and after the injection molded product is attached to the hollow molded product containing the liquid seasoning and left in a predetermined high-temperature space for a predetermined period of time, the degree of blocking between the injection molded product and the hollow molded product and the ease of separating them are evaluated on a five-point scale (1 being the worst and 5 being the best).

The common conditions for this test, as well as the conditions for the examples and comparative examples, are listed below.

<Common conditions for this test>
Injection molded product: First lubricant = EBO (melting point = 100°C or higher, molecular weight = 589), second lubricant = oleic acid amide (melting point = less than 100°C), main component = polyethylene or polyolefin resin, thread pitch and height = 1.25 mm and 0.65 mm, outer diameter = 8.5 mm, thickness = 1.0 mm
Hollow molded product: Molding method = Extrusion blow, First lubricant, Second lubricant, Main component, Thread pitch and height = Same as injection molded product, Shape: Long and thin cylinder, Capacity = 6 ml, Thickness = 0.5 mm
Content of secondary lubricant in injection molded products and hollow molded products = 750 ppm
Test environment: A box containing a plurality of liquid seasoning-filled containers, each having an injection molded product attached to a hollow molded product containing liquid seasoning, was left in a room at 40° C. for 7 days.

Example 1
Injection molded product: content of first lubricant = 1000 ppm, Hollow molded product: content of first lubricant = 0
Example 2
Injection molded product: content of first lubricant = 0, Hollow molded product: content of first lubricant = 1000 ppm
Example 3
Injection molded product: content of first lubricant = 500 ppm, Hollow molded product: content of first lubricant = 500 ppm
Example 4
Injection molded product: content of first lubricant = 200 ppm, Hollow molded product: content of first lubricant = 0
Example 5
Injection molded product: content of first lubricant = 350 ppm, Hollow molded product: content of first lubricant = 0
Example 6
Injection molded product: content of first lubricant = 750 ppm, Hollow molded product: content of first lubricant = 0
Example 7
Injection molded product: content of first lubricant = 1500 ppm, Hollow molded product: content of first lubricant = 0
Example 8
Injection molded product: content of first lubricant = 2000 ppm, Hollow molded product: content of first lubricant = 0

<Comparative Example 1>
Injection molded product: content of first lubricant = 0, Hollow molded product: content of first lubricant = 1000 ppm

<Supplementary information on Examples and Comparative Examples>
In Examples 1 to 3, the difference in the content of the first lubricant in the injection molded product and the hollow molded product (0, 500 ppm, or 1000 ppm) is considered, and in Examples 1 and 4 to 8, the difference in the content of the first lubricant only in the injection molded product (200 to 2000 ppm) is considered together with Comparative Example 1.

<Considerations of Examples 1 to 3>
As shown in Table 1, according to the above examples, the best evaluation was achieved when the content of the first lubricant in the injection molded product, the content of the first lubricant in the hollow molded product, and the total content of the first lubricant in the injection molded product and the hollow molded product were each 1000 ppm. In addition, in comparison between the above examples and Comparative Example 1, the worst evaluation was achieved when the content of the first lubricant in the injection molded product and the hollow molded product was zero.
In addition, according to Example 6, the injection molded product achieved the best evaluation even though the content of the first lubricant in the injection molded product was 750 ppm.

<Considerations of Example 1 and Examples 4 to 8>
As shown in Table 2, according to the above examples, when the content of the first lubricant in the injection molded product was 350 ppm or less, it did not reach the best evaluation, but when it was 750 ppm or more, it reached the best evaluation. In addition, comparing the above examples with Comparative Example 1, when the content of the first lubricant in the injection molded product was at least zero, it was rated as the worst.

T Liquid seasoning filled container 1 Injection molded product 11a Thread 2 Hollow molded product 21 Protrusion 21a Thread 22 Storage part

Claims (7)

A liquid seasoning container having an injection molded product with a screw thread formed therein,
Contains a first lubricant having a melting point of 100° C. or more and a second lubricant having a melting point of less than 100° C.
The first lubricant is an unsaturated higher fatty acid bisamide,
The content of the first lubricant is 500 to 1500 ppm.
A liquid seasoning filled container. A liquid seasoning container having a hollow molded product with a screw thread formed thereon,
Contains a first lubricant having a melting point of 100° C. or more and a second lubricant having a melting point of less than 100° C.
The first lubricant is an unsaturated higher fatty acid bisamide,
The content of the first lubricant is 500 to 1500 ppm.
A liquid seasoning filled container. 3. The liquid seasoning filling container according to claim 1 , wherein the unsaturated higher fatty acid bisamide is ethylene bisoleamide (EBO) or ethylene biserucamide (EBE) . The pitch of the thread is 2.0 mm or less,
4. A liquid seasoning filling container according to claim 1 , wherein the height of the screw thread is 0.5 mm or more. 5. The liquid seasoning-filled container according to claim 1 , wherein a main component is a polyolefin-based resin . 6. The liquid seasoning filling container according to claim 1, wherein the content of the second lubricant is 500 to 1000 ppm.
The injection molded product and the hollow molded product are provided,
7. The liquid seasoning filling container according to claim 1, wherein the threads of the injection molded product and the threads of the hollow molded product face each other.

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