JP4640790B2 - container - Google Patents

Description

  The present invention relates to a container suitably used for housing various liquids and powders.

  There is known a liquid dispensing container in which a cap attached to the mouth and neck of a container body includes an inner cylinder, and an outer surface of the inner cylinder is in contact with an inner wall surface of the mouth and neck to form a sealing surface (for example, Patent Document 1). reference). In this liquid dispensing container, the outer diameter of the inner cylinder is set slightly larger than the inner diameter of the mouth and neck, and when the cap is attached to the mouth and neck, the inner cylinder moves the mouth and neck outward. A sealing surface is formed by spreading. In this state, tensile stress is applied to the mouth and neck.

  In this type of container, when the operation of pouring out the liquid contained in the container is repeated, the liquid may adhere to the mouth and neck. As described above, since tensile stress is applied to the mouth and neck, depending on the type of liquid contained in the container, the mouth and neck may cause environmental stress destruction (hereinafter referred to as ESC). . ESC is a brittle fracture that occurs with a tensile stress below the tensile strength of the resin. When ESC occurs in the mouth and neck, a crack occurs in the mouth and neck, and the liquid as the contents may leak from the crack.

  In order to prevent the occurrence of ESC, for example, it is conceivable to adopt a technique in which the difference between the outer diameter of the inner cylinder and the inner diameter of the mouth-neck portion is reduced to reduce the tensile stress applied to the mouth-neck portion. However, in this method, there is a possibility that a sealing surface is not surely formed between the inner cylinder and the mouth-neck portion due to subtle fluctuations in dimensions at the time of molding, thereby causing liquid leakage from the sealing surface. there is a possibility.

  Another approach is to increase the strength of the mouth and neck. For example, it has been proposed to increase the strength by crystallizing the constituent resin of the mouth and neck (see Patent Document 2). Although this method is effective in suppressing the occurrence of ESC, it requires a large amount of manufacturing equipment and is inferior in terms of manufacturing cost.

As a method other than these, it has been proposed to interpose an inner ring which is a separate member between the mouth neck and the inner cylinder (see Patent Document 3). This method is also effective in suppressing the occurrence of ESC, but the amount of resin used is increased by the amount of inner ring.
JP 61-93061 A JP-A-11-254515 JP 2004-210354 A

  Accordingly, an object of the present invention is to provide a container that can eliminate the various drawbacks of the prior art described above.

The present invention is a container having a cap attached to the mouth and neck of the container body, and used for containing contents containing an agent that induces environmental stress destruction,
The cap has an inner cylinder portion whose outer surface forms a sealing surface in close contact with the inner wall surface of the mouth and neck portion in the attached state to the mouth and neck portion,
A container having a flexural modulus (JIS K7171) of 2000 to 3000 MPa as a constituent material of the container body and a container having a flexural modulus (JIS K7171) of 650 to 1100 MPa as a constituent material of the cap. The object is achieved by providing.

  In the container of the present invention, even when an agent that induces ESC is contained in a state where tensile stress is applied to the mouth and neck of the container body, it is difficult for ESC to occur in the mouth and neck, and the contents leak out. Is prevented.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 shows a cross-sectional view of a main part in an embodiment of the container of the present invention. The container 10 of the present embodiment is made of resin, and has a cap 20 attached to the mouth and neck portion 12 of the container body 11 as shown in FIG. An engagement protrusion 13 is attached to the outer wall surface of the substantially intermediate portion in the height direction of the mouth / neck portion 12 of the container body 11. A portion of the mouth / neck portion 12 above the engagement protrusion 13 is a small outer diameter portion, and a plurality of anti-rotation protrusions 14 extending in the vertical direction are attached to the outer wall surface of the small outer diameter portion. ing.

  The cap 20 has a cap body 21 that is attached to the opening of the container body 11 by fitting, and a cover cap 22 that is attached to and detached from the cap body 21 by screwing (or fitting) or the like. The cover cap 22 is used as a measuring cup that receives and measures the content liquid poured out from the cap body 21. The cap 20 is attached to the container body 11 filled with the contents in the form of an assembly in which the cover cap 22 is attached to the cap body 21.

  The cap body 21 includes an outer cylinder part 31, a top surface part 32 extending inwardly from the upper end of the outer cylinder part 31, and an inner cylinder part 33 depending from the inner periphery of the top surface part 32. Yes. From the upper surface of the top surface portion 32, the cap fitting cylinder 34 stands up. The inner cylinder part 33 is surrounded by the outer cylinder part 31. An annular recess is formed in the cap body 21 by the outer cylinder portion 31, the top surface portion 32 and the inner cylinder portion 33. The neck and neck 12 of the container body 11 is fitted into the annular recess.

  The outer diameter of the inner cylinder part 33 is set slightly larger than the inner diameter of the mouth and neck part 12. Therefore, when the cap body 21 is attached to the mouth / neck portion 12, the inner cylinder portion 33 spreads the mouth / neck portion 12 outward, and as a result, the outer surface of the inner cylinder portion 33 is the surface of the mouth / neck portion 12. An annular sealing surface is formed in close contact with the inner wall surface.

  On the lower inner wall surface of the outer cylinder portion 31, a ridge 35 that engages with the lower surface of the engagement ridge 13 of the mouth-and-neck portion 12 described above is provided. On the inner wall surface of the outer cylinder portion above the protrusion 35, the fitting protrusion 36 that meshes with the rotation-preventing protrusion 14 of the mouth-and-neck portion 12 is attached so as to extend in the vertical direction.

  A partition plate 40 that partitions the inside and the outside of the cap body 21 extends inward from the lower end of the inner cylinder portion 33. From a substantially central portion of the partition plate 40, a bowl-shaped extraction tube 41 that is substantially concentric with the inner tube portion 33 protrudes upward. The bowl-shaped dispensing cylinder 41 is surrounded by the inner cylinder portion 33 and is coupled to the inner cylinder portion 33 via the partition plate 40. The tip of the bowl-shaped extraction tube 41 protrudes higher than the cap fitting tube 34 of the cap body 21 described above.

  The cap body 21 is formed with an annular liquid recovery portion 43 defined by the dispensing tube 41, the inner tube portion 33 and the partition plate 40. The partition plate 40 is inclined downward from the dispensing direction of the container 10 (indicated by an arrow in FIG. 1) in the opposite direction. The degree of inclination of the partition plate 40 is appropriately adjusted according to the type of contents.

  The bottom of the dispensing cylinder 41 is open to form a circulation port 42. The pouring cylinder 41 guides the contents taken from the container main body 11 through the circulation port 42 and pours out from the pouring spout 41A at the upper end of the pouring cylinder 41. In addition, a slit 44 </ b> A extending in the longitudinal direction of the dispensing cylinder 41 is formed in the dispensing cylinder 41 on the side surface opposite to the dispensing direction of the container 10 (indicated by an arrow in FIG. 1). The slit 44 </ b> A communicates with a liquid return port 44 </ b> B provided in the liquid recovery unit 43. The liquid return port 44B is formed at the lowest position in the partition plate 40 provided to be inclined.

  The cover cap 22 includes a top plate 50 and a measuring tube 51 that hangs down from the outer periphery of the top plate 50. An outward flange 52 extending in the horizontal direction from the outer wall surface of the measuring tube 51 is formed at a substantially intermediate portion in the height direction of the measuring tube 51. In a state where the cover cap 22 is attached to the cap body 21, the outward flange 52 is placed on the cap fitting cylinder 34 of the cap body 21. An outer cylinder 53 is suspended from the outer periphery of the outward flange 52. A male thread is attached to the inner wall surface of the outer cylinder 53, and this male thread is engaged with a female thread attached to the outer wall surface of the cap fitting cylinder of the cap body 21. In the screwed state, the inner ring 54 depending from the lower surface of the outward flange 52 is in close contact with the inner wall surface of the cap fitting tube 34 to form a seal surface.

  In the container 10 of the present embodiment, the container 10 is tilted in the direction indicated by the arrow in FIG. 1 with the cover cap 22 removed from the cap body 21, and the contents are poured out from the bowl-shaped dispensing tube 41. The contents are injected into the measuring cylinder 51. When the desired amount of content is poured out, the container 1 is returned to the upright posture, and the pouring from the pouring cylinder 41 is terminated. At this time, a part of the contents flows down from the spout 41 </ b> A at the upper end of the pouring cylinder 41 along the outer wall surface of the pouring cylinder 41. The content that has flowed down is collected by the liquid recovery unit 43 and flows down along the inclined partition plate 40 toward the liquid return port 44B. Then, the contents are collected into the container body 11 through the liquid return port 44B.

  The container body 11 in the container 10 is made of a resin having a flexural modulus measured in accordance with JIS K7171 (hereinafter referred to as a value measured by this method) of 2000 to 3000 MPa, preferably 2200 to 2700 MPa. Has been. On the other hand, the cap body in the container 10 is made of a resin having a flexural modulus of 650 to 1100 MPa, preferably 800 to 1000 MPa. By adopting a combination of resins having a flexural modulus in such a range, an agent that induces ESC (hereinafter also referred to as an ESC inducer) under a state in which tensile stress is applied to the mouth and neck portion 12 of the container body 11. It was found by the present inventors that ESC does not occur in the mouth-and-neck portion 12 even when the contents including) are accommodated. The reason for this is considered to be that the tensile stress applied to the mouth-and-neck portion 12 is relaxed by the combination of the above-described resins, and it is difficult for the ESC inducer to penetrate into the mouth-and-neck portion.

  Examples of the resin having a flexural modulus in the above range that is preferably used as a constituent material of the container body 11 include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyvinyl chloride (PVC). Vinyl polymer and the like. In particular, by combining the container body 11 using a polyester resin having a bending elastic modulus in the above range and the cap 21 using a resin having a bending elastic modulus in the above range, it is possible to effectively generate ESC in the container main body 11. This is preferable. In particular, by using PET or PEN, it is possible to realize the container body 11 having a colored or colorless transparent member as a constituent material. In particular, PET has the advantage of being cheaper than PEN. From the viewpoint of preventing the occurrence of ESC, it is generally more effective to use polyethylene or polypropylene than to use PET or PEN. However, polyethylene and polypropylene have low transparency. A random copolymer of polypropylene is much more transparent than polyethylene or polypropylene, but inferior to PET or PEN. In addition, although a random copolymer of polypropylene has an advantage that it is cheaper than PET or PEN, it is not suitable as a material for a container because the impact resistance of a molded product is weak. The impact resistance can be increased by mixing polyethylene with a random copolymer of polypropylene, but on the other hand, the transparency becomes considerably low, resulting in a cloudy, white cloudy impression. Considering these comprehensively, it is advantageous to use PET or PEN from the viewpoint of suppressing the occurrence of ESC while realizing the transparent container body 11. By adding a colorant to PET or PEN, it is possible to make the container body 11 colored or translucent or translucent or opaque.

  On the other hand, as a resin having a flexural modulus in the above range that is preferably used as a constituent material of the cap body 21, a polyolefin resin such as polypropylene using at least propylene as a monomer, an acetal resin, polyethylene terephthalate, Examples include polybutyne terephthalate, 6-nylon, 6, 6-nylon, 12-nylon, and ABS resin. In particular, it is preferable to use polypropylene because the occurrence of ESC can be effectively suppressed while maintaining the fitting strength between the cap body 21 and the mouth and neck portion 12. In addition, the polyolefin-based resin has an advantage that it has good slip suitability on the cap sorter on the production line and on the rail at the time of alignment as compared to other resins such as low density polyethylene, and the line suitability is good. There is. Furthermore, the polyolefin-based resin is less likely to burn when it stays in a plasticizer of an injection molding machine as compared with other resins such as low-density polyethylene. Therefore, foreign matter resulting from scorch is not easily mixed into the molded product, and there is an advantage that a product excellent in appearance and quality can be obtained.

  If the flexural modulus is within the above range, the type of the polyolefin resin is not particularly limited. For example, a homopolymer of propylene and a propylene copolymer using propylene and other polymerizable monomers can be used.

  As is clear from the above description, the container 10 of the present embodiment is effective for containing the contents containing the ESC inducer. Various ESC inducers are known. Examples thereof include chlorine-based oxides such as hypochlorite and dichloroisocyanurate, peroxides such as hydrogen peroxide and sodium percarbonate, various surfactants and organic solvents.

In particular, as the organic solvent, those having a log P _OW of −1.0 to 3.0, particularly −0.8 to 2.0, particularly −0.5 to 1.5 are likely to induce ESC. It became clear as a result of examination. According to the container 10 of this embodiment, even if the content containing such an organic solvent is accommodated, generation | occurrence | production of ESC is suppressed effectively. Here, logP _OW is a coefficient indicating the affinity of the organic solvent for water and 1-octanol, and is a 1-octanol / water partition coefficient, which is a value obtained by calculation by the f-value method (hydrophobic fragment constant method). Say. Specifically, the chemical structure of an organic solvent is decomposed into its constituent components, and the hydrophobic fragment constant (f value) of each fragment is integrated (CLOGP3 Reference Manual Daylight Software 4.34, Albert Leo, David Weininger, Version 1, March 1994).

Examples of the organic solvent having logP _{OW in the} above range include those represented by the following formulas (1), (2), and (3).
R ¹ —OH (1)
[In formula, R < ¹ > shows a C4-C8 hydrocarbon group, for example, an alkyl group, an allyl group, or an allylalkyl group. ]
R ² — (O—R ³ ) f—O—R ⁴ (2)
[Wherein R ² and R ⁴ represent a hydrogen atom, R ⁸ CO—, a hydrocarbon group having 1 to 7 carbon atoms such as a hydrogen atom, an alkyl group, an allyl group, or an allylalkyl group, and R ³ represents a carbon number 2-9 alkylene groups are shown. f is a number from 1 to 5. R ⁸ represents an alkyl group having 1 to 3 carbon atoms. ]
R ⁵ —O—CH ₂ CH (O—R ⁶ ) CH ₂ —O—R ⁷ (3)
[Wherein R ⁵ represents an alkyl group having 3 to 8 carbon atoms, and R ⁶ and R ⁷ represent an alkyl group having 1 to 3 carbon atoms which may be substituted with a hydrogen atom or a hydroxy group. ]

  Specific examples of the organic solvent represented by the above formulas (1), (2) and (3) include n-butanol, isobutanol, 2-butanol, n-hexanol, cyclohexanol, phenol, benzyl alcohol and phenethyl. Alcohol, 2-phenoxyethanol, 2-benzyloxyethanol, diethylene glycol monobenzyl ether, diethylene glycol monophenyl ether, triethylene glycol monophenyl ether, tetraethylene glycol monophenyl ether, 2-ethylhexane-1,3-diol, hexane-1 , 6-diol, nonane-1,6-diol, 2-methyloctane-1,8-diol, 2-butoxyethanol, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether 2- (2-methyl) propoxyethanol, diethylene glycol mono-2-methylpropyl ether, 2-propoxy-1-propanol, dipropylene glycol monopropyl ether, 2-butoxy-1-propanol, dipropylene glycol monobutyl ether, 2-t-butoxy-1-propanol, 2-phenoxy-1-propanol, 2-ethoxypropyl-1-acetate, 2-propoxypropyl-1-acetate, 1,2-diacetoxypropane, 3-dimethyl-3 Examples include -methoxy-1-propanol, 1,3-dimethylbutyl glyceryl ether, pentyl glyceryl ether, and hexyl glycetyl ether.

  In the container 10 of the present embodiment, the various ESC inducers may be stored alone, or may be stored in a state diluted with a solvent such as water. The contents stored in the container 10 may be a liquid or a solid such as a powder. ESC tends to occur when the contents are liquid rather than solid.

  As is clear from the above description and the examples to be described later, according to the container 10 of the present embodiment, ESC is generated in the mouth-and-neck portion 12 of the container body 11 even if the contents containing the ESC inducer are accommodated. It becomes difficult. Further, by fitting the cap body 21 to the mouth-and-neck portion 12, the amount of resin used can be reduced compared to the case of screwing, which is economical. Moreover, since the amount of resin discharged after use can be reduced, the environmental load is reduced. Furthermore, since there is no need to interpose an inner ring as a separate member between the mouth / neck portion 12 and the cap body 21, it is economical from this point of view and the environmental load is reduced. By not using the inner ring, the volume of the liquid recovery unit 43 can be increased when using the container body of the mouth and neck having the same inner diameter as compared to when the inner ring is inserted. There are also advantages. The ability to increase the volume of the liquid recovery unit 43 is advantageous in that the content can be prevented from overflowing from the liquid recovery unit 43 when the content is replenished.

  The present invention is not limited to the embodiment. For example, in the above-described embodiment, the cap body 21 is fitted to the mouth / neck portion 12 of the container body 11, but the cap body may be screwed to the mouth / neck portion instead.

  In addition, according to the container 10 of the above-described embodiment, the occurrence of ESC in the mouth-and-neck portion 12 is effectively suppressed, but for the purpose of further suppressing the occurrence of ESC, Patent Document 2 described above is used. It is not impeded to apply the crystallization technique described in 1 to the mouth-and-neck portion 12.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Example 1]
A container having the form shown in FIG. 1 was produced. The container body was manufactured by injection molding using polyethylene terephthalate having a flexural modulus of 2400 MPa. The cap body was manufactured by injection molding using polypropylene having a flexural modulus of 950 MPa.

  This container contained propylene glycol diluted with water. The concentration was 14% by weight. The container in this state was stored at 50 ° C. for 1 month. The condition of the mouth and neck after storage was visually observed. As a result, no defects such as cracks occurred in the mouth and neck.

[Comparative Example 1]
In Example 1, the cap body was manufactured by injection molding using a propylene homopolymer having a flexural modulus of 1650 MPa. A container was obtained in the same manner as in Example 1 except for this. The same contents as in Example 1 were accommodated in this container and stored under the same conditions as in Example 1. When the state of the mouth and neck after storage was visually observed, cracks were found in the mouth and neck.

It is principal part sectional drawing of one Embodiment of the container of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Container 11 Container main body 12 Mouth neck part 20 Cap 21 Cap main body 22 Cover cap 33 Inner cylinder part

Claims (4)

A cap is attached to the mouth and neck of the container body, and is a container used to contain contents containing an agent that induces environmental stress destruction,
The cap has an inner cylinder portion whose outer surface forms a sealing surface in close contact with the inner wall surface of the mouth and neck portion in the attached state to the mouth and neck portion,
A container using a material having a flexural modulus (JIS K7171) of 2000 to 3000 MPa as a constituent material of the container body and a material having a flexural modulus (JIS K7171) of 650 to 1100 MPa as a constituent material of the cap.   The cap further includes an outer cylinder part surrounding the inner cylinder part, and an annular recess is formed between the inner cylinder part and the outer cylinder part, and the mouth and neck part is fitted in the annular recess. The container according to claim 1.   The container according to claim 1 or 2, wherein the constituent material of the container body is a polyester resin, and the constituent material of the cap is a polyolefin resin using at least propylene as a monomer. The cap further includes a partition plate extending inwardly from a lower end of the inner tube portion, and a pouring tube surrounded by the inner tube portion and coupled to the inner tube portion via the partition plate. The container according to any one of claims 1 to 3, wherein an annular liquid recovery part is formed by the inner cylinder part, the dispensing cylinder and the partition plate.

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