JP2010137883A - Bottle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a bottle formed by biaxially stretching blow-molding a resin containing a polylactic acid, the problem being that when a dome-like expansion part is formed in the upper part of the bottle so as to have an oval cross-sectional shape and a waist continuous with the expansion part and narrowing inside is formed below the expansion part, stress concentrates on the waist, with result that the cross-sectional shape of the waist is deformed into a slanting oval shape from an original oval shape. <P>SOLUTION: The bottle 1 has a bottom 5 having a ground face F and formed by biaxially stretching blow-molding resin containing a polylactic acid. The bottle 1 has the oval cross-sectional shape, and the dome-shaped expansion part 3 in the upper part of the bottle 1. A waist part 4 is formed below the expansion part 3 so as to be continuous with the expansion part 3 and narrow inside. The waist part 4 is provided with an annular rib 7 extending around the bottle axis O. The rib 7 is disposed within the range of 5 mm above or below the narrowest part 4a of the waist along the axial line of the bottle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bottle that is easily decomposed by natural decomposition.

As a bottle that can be easily discarded, there is a bottle formed by blow molding a resin containing polylactic acid (see, for example, Patent Document 1).
JP 2002-274521 A

However, it is known that such a resin containing a lactic acid component is relatively brittle and has low impact strength (see, for example, Patent Document 2).
Japanese Patent No. 3809850

  For this reason, the cross-sectional shape of the bottle formed by blow molding a resin containing polylactic acid is an elliptical shape, and a bulge portion such as a dome shape is formed on the upper portion of the bottle, and below the bulge portion, When forming a waist part that is constricted on the inside in connection with the bulging part, the bottle with such a shape is loaded by applying a load from the top during loading, or by attaching a label to the waist part using a labeler. The cross-sectional shape of the waist part (particularly the deepest part of the waist part) may be deformed into an oblique elliptical shape with respect to the original elliptical shape.

  In contrast, in order to increase the mechanical strength (rigidity) of the waist part, the inventor of the present application has increased the rigidity by providing ribs on the waist part. However, the bottle containing polylactic acid is as described above. Since the impact strength is lower than that of a resin containing PET, cracks and the like are likely to occur.

  For this reason, for example, when the rib is an annular recess in which a concave portion curved toward the inside of the bottle circulates around the axis of the bottle, the depth of the concave portion is increased or R (curvature) forming the concave portion is formed. If the mechanical strength (rigidity) of the waist part is extremely increased by reducing the radius, cracking or the like may occur. For this reason, this inventor came to recognize that there exists a limit in improving the mechanical strength of a waist part by changing the form of the rib determined by the depth of a rib, a curvature radius, etc.

The problem to be solved by the present invention is that, in a bottle formed by biaxial stretching blow molding of a resin containing polylactic acid, the cross-sectional shape thereof is elliptical, and a bulging portion is formed at the top of the bottle, and When forming a waist part that is constricted inward on the lower side of the protruding part, connected to the bulging part,
When stress concentrates on the waist portion, the cross-sectional shape of the waist portion is deformed into an oblique elliptical shape with respect to the original elliptical shape.

The present invention has a bottom portion having a ground contact surface, and is a bottle formed by biaxially stretch blow molding a resin containing polylactic acid,
The bottle has an elliptical cross-sectional shape, and has a bulging portion at the top of the bottle, and a waist portion that is constricted inward from the bulging portion below the bulging portion. And forming
An annular rib that circulates around the axis of the bottle is provided at a predetermined position including the deepest portion of the waist portion. In addition, it is preferable that the said bulging part is dome shape.

  According to the present invention, the predetermined position including the deepest part of the waist part extends in the vertical direction along the axis of the bottle, and ranges from 8 mm above to 5 mm below from the deepest part of the waist part. In this range, it is preferable to dispose such a rib, but it is more preferable to dispose the rib within a range of 5 mm above and below the deepest part. In the present invention, in particular, it is more preferable that the upper limit is a position of 2 mm toward the upper side along the axis of the bottle from the deepest point, while the lower limit is a position of 1 mm or less toward the lower side. Most preferably, it is arranged at the deepest part.

  The rib is an annular concave portion in which a concave portion curved toward the inside of the bottle is made to circulate around the axis of the bottle, and each end portion of the concave portion is a curved surface continuous to the waist portion excluding the concave portion. Can be mentioned. The bottle may be a resin containing at least polylactic acid.

  Furthermore, the present invention can be applied as a seasoning-filled bottle filled with a seasoning, and edible oil is particularly preferable as the seasoning.

  In addition, the present invention is a bottle formed by biaxial stretching blow molding a resin containing polylactic acid, but as a resin to be used from the viewpoint of natural degradation, polylactic acid alone is 100% by mass, Alternatively, it is preferable to use a resin blended with another biodegradable resin.

In the present invention, in a bottle formed by biaxial stretching blow molding of a resin containing polylactic acid, the cross-sectional shape is an elliptical shape, and a bulge is formed at the top of the bottle, and the lower side of the bulge And forming a waist portion constricted inward from the bulging portion,
Furthermore, since an annular rib that circulates around the axis of the bottle is provided at the waist, even when stress is concentrated on the waist, the shape is geometrically changed by the rib. The mechanical strength of the waist can be increased. Therefore, when stress concentrates on the waist, it is possible to suppress the occurrence of a phenomenon in which the cross-sectional shape is deformed into an oblique elliptical shape with respect to the original elliptical shape.

  In addition, according to the present invention, the rib is disposed within the range of 8 mm above to 5 mm below from the deepest part of the waist part in the range extending vertically along the axis of the bottle. Thus, apart from increasing the mechanical strength by changing the shape of the rib, the mechanical strength in the vicinity of the deepest portion of the waist portion where deformation easily occurs can also be achieved by the arrangement of the rib.

  Therefore, according to the present invention, it is possible to provide a rib for increasing the mechanical strength without causing a crack or the like in the waist portion, thereby effectively increasing the mechanical strength of the waist portion. The deformation | transformation which generate | occur | produces in a waist part can be prevented effectively.

  In particular, the rib is an annular recess formed by circling around the axis of the bottle with a part of the waist curved toward the inside of the bottle, and each end of the rib is a waist excluding the rib. If the curved surface is continuous toward the part, excessive stress concentration on the rib can be reduced.

  Hereinafter, an embodiment of a bottle according to the present invention will be described in detail with reference to the drawings.

  1A and 1B are a front view and a side view showing a bottle 1 which is an embodiment of the present invention. FIGS. 2A to 2C are an AA sectional view, a BB sectional view, and a bottom view of FIG. 1A, respectively. 3 (a) and 3 (b) are an enlarged cross-sectional view of the main part showing the rib 2 provided on the bottle 1, and a transverse cross-sectional view showing a deformed state at the waist part.

  The bottle 1 is made of a resin containing polylactic acid that is reduced in molecular weight by being hydrolyzed with moisture in the environment and that is finally decomposed into carbon dioxide and water by the action of microorganisms or the like (not shown). The preform is formed by biaxial stretch blow molding of the preform.

  Further, the bottle 1 has an elliptical cross-sectional shape, and has a mouth portion 2 as an upper end portion and a dome-shaped bulging portion 3 below the mouth portion 2 as shown in FIGS. . As shown in the drawings, the bulging portion 3 has a shape covered with a bowl, which is formed by expanding the diameter outward from the lower side of the mouth portion 2.

  The bulging portion 3 has an elliptical cross-sectional shape, and as seen from a comparison of FIGS. 1 (a) and 1 (b), the appearance when viewed from the front is the appearance when viewed from the side. The shape is wider than the shape. Moreover, the bulging part 3 becomes the largest diameter in the AA cross-section part shown to Fig.1 (a). As shown in FIG. 2 (a), the maximum diameter portion (hereinafter referred to as “maximum bulging portion 3a”) has a short diameter Aa (x) extending perpendicularly to the front surface and a long diameter Aa. (y) extends perpendicular to the side.

  In addition, as shown in FIGS. 1 and 2, the bottle 1 has a waist portion 4 that is connected to the maximum bulging portion 3 a and is constricted inside the bottle 1. As shown in the drawings, the waist portion 4 has a minimum diameter portion (hereinafter referred to as “waist deepest portion 4a”) that becomes the minimum diameter in the BB cross-section portion by reducing the diameter inward from the maximum bulge portion 3a. And after reaching the waist deepest part 4a, it is formed into a drawing shape that is formed by expanding outward from the waist deepest part 4a.

  In addition, the diameter expansion from the waist deepest part 4a becomes a maximum diameter in CC cross-section part, and the bottom part 5 continues in this maximum diameter part (henceforth "the trunk | drum skirt part 4b").

  The waist 4 also has an elliptical cross-sectional shape, and as is apparent from a comparison of FIGS. 1 (a) and 1 (b), the appearance when viewed from the front is the appearance when viewed from the side. Compared to the shape of the wide. Further, as shown in FIG. 2B, the deepest waist portion 4a has a short diameter Ab (x) extending perpendicular to the front surface and a long diameter Aa (y) perpendicular to the side surface. Extend.

  In addition, as shown in FIG. 1, the reduced pressure absorption panel 4c is formed in the front and back surface between the waist deepest part 4a and the trunk | drum skirt part 4b, respectively.

  As shown in FIGS. 1 and 2, the bottom 5 has a cylindrical shape formed by hanging from the trunk skirt 4 b, and a flat ground surface f is formed at the lower end thereof. In addition, as shown in FIG.2 (c), the bottom part 5 has comprised the substantially octagonal column shape which the front and back, and the right-and-left side face comprised a plane, and was connected by the column part which curves between them gently. .

  In the case of a bottle having such a waist portion, when the load is applied from the mouth portion 2 at the time of loading, or by attaching a label to the trunk portion including the waist portion 4 using a labeler, the waist portion 4 (particularly, The cross-sectional shape of the waist deepest part 4a) may be deformed into a slanted elliptical shape as shown by the broken line in FIG. 3 (b) with respect to the original elliptical shape shown by the solid line in FIG.

  Therefore, the waist portion 4 is provided with an annular rib 7 that circulates around the axis L of the bottle 1 (hereinafter referred to as “bottle axis”). If the rib 7 is provided in the waist part 4, the mechanical strength of the waist part 4 is increased, so that deformation accompanying stress concentration on the waist part 4 can be suppressed.

  However, since the bottle 1 is made of a resin containing polylactic acid having a low mechanical strength in the first place, the mechanical strength is increased by geometrically changing the shape of the rib, for example, by providing a rib on the waist 4. There are also limits.

Therefore, as shown in FIG. 3 (a), the rib 7 is formed by curving a part 4d of the waist portion 4 toward the inside of the bottle 1 with a radius of curvature r ₁ and rotating around the bottle axis L. A curved surface formed with a radius of curvature r ₂ toward the outside of the bottle 1 as shown in the figure, with each end 4e of the rib (a part 4a of the waist part 4 forming the rib 7) 7 being a recess. By doing so, the waist portion 4 excluding the concave portion 7 is configured to be smoothly connected.

  According to such a configuration, concentration of stress applied to the rib 7 from the outside can be suppressed, and a certain level of mechanical strength can be ensured even for a bottle made of a resin containing polylactic acid having low mechanical strength. However, since the shape of the rib 7 is specified as described above, the effect of providing the rib 7 on the waist portion 4 for the bottle 1 cannot be fully exhibited.

  Therefore, in the present invention, in order to further improve the mechanical strength, the rib 7 extends in the up and down direction along the axis L of the bottle 1 with the waist deepest part 4a as the base point and the upper side from the base point. While the upper limit is a position 8 mm away, the lower limit is a position 5 mm below the base point.

  4 (a) to 4 (c) respectively show a configuration in which a rib 7 is provided at a position below the waist deepest portion 4a according to the present invention, and a minimum diameter portion of the rib 7 (hereinafter referred to as “rib” It is a perspective view which shows typically the form which provided the said rib 7 in the position which 7a (referred to as "deepest part") corresponds, and the form which provided the rib 7 in the position above the waist deepest part 4a.

  5 (a) and 5 (b) are a front view schematically showing the positional relationship with the deepest waist portion 4a when the rib 7 is arranged according to the present invention, and the deepest waist in FIG. 5 (a). It is a principal part enlarged view which expands the vicinity of the part 4a and shows the relationship with the position of the rib 7 typically.

The above range will be described in detail. As shown in FIG. 5A, the position Lo of the waist deepest portion 4a from the ground contact surface f is defined as a reference position (hereinafter referred to as “reference position Lo”). As shown, the lower limit of the preferred range is between positions L ₁ and L ₅ that are 5 mm downward from the reference position Lo along the bottle axis L, and 8 mm upward from the reference position Lo along the bottle axis L. position L ₆ is the upper limit of the preferred range. A more preferable range is a range between the lower limit L ₁ and the upper limit L ₂ (L ₁ ≦ Lo ≦ L ₂ ).

For this reason, as shown in FIG. 4, the position where the deepest portion 7 a is disposed with respect to the ground contact surface f is the position of the rib 7 (hereinafter referred to as “rib position”) L _7. For example, as shown in FIG. 5, the rib position L ₇ is in a range between the lower limit value L ₁ and the upper limit value L _2, which is a more preferable range (L ₁ ≦ L ₇ ≦ L ₂ ). What is necessary is just to arrange. However, according to the present invention, when the rib 7 is arranged in the range (L ₁ ≦ L ₇ ≦ L ₂ ), if the rib deepest portion 7a coincides with the waist deepest portion 4a, the waist portion 4 The mechanical strength can be maximized. For this reason, about the rib 7 which concerns on this form, as shown in FIG. 1, the rib deepest part 7a is arrange | positioned so that it may correspond with the waist deepest part 4a.

That is, in the bottle 1 formed by biaxial stretching blow molding of a resin containing polylactic acid, the cross-sectional shape is elliptical as in this embodiment, and the dome-shaped bulging portion 3 is formed on the bottle 1. And forming a waist portion 4 constricted inward from the bulging portion 4 below the bulging portion 3,
Furthermore, if an annular rib 7 that circulates around the axis L is provided on the waist portion 4, the shape is geometrically changed by the rib 7 even when stress is concentrated on the waist portion 4. The mechanical strength of the waist part 4 can be increased. Therefore, according to the present embodiment, it is possible to suppress the occurrence of a phenomenon in which the stress is concentrated on the waist portion 4 so that the cross-sectional shape thereof is deformed into an oblique elliptical shape with respect to the original elliptical shape.

  In addition, according to the present embodiment, the rib 7 is arranged in the range of 8 mm above to 5 mm below from the waist deepest part 4a in the range extending in the vertical direction along the bottle axis L. Thus, apart from increasing the mechanical strength by the change in the shape of the rib 7, the mechanical strength in the vicinity of the waist deepest portion 4a where deformation easily occurs can be increased by the arrangement of the rib 7.

  Therefore, according to this embodiment, it is possible to provide the rib 7 for increasing the mechanical strength without causing cracks or the like in the waist portion 4, thereby effectively increasing the mechanical strength of the waist portion 4. Since it raises, the deformation | transformation which generate | occur | produces in the said waist part 4 by the stress concentration to the waist part 4 can be prevented effectively.

  In particular, as in the present embodiment, the rib 7 is an annular recess formed around the axis L in which a portion 4d of the waist portion 4 is curved toward the inside of the bottle 1, and the end of the rib 7 If each of the portions 4e is a curved surface that gradually leads toward the waist portion 4 excluding the rib 7, excessive stress concentration on the rib 7 can be alleviated.

<Bond bending strength>
A flat rigid body is placed on the mouth part 2 of the bottle 1 (polylactic acid content: 100% by mass) according to the present invention, and the bending strength when a load is applied to the bottle 1 depends on the change in the position of the rib. The analysis results are shown in Table 1.

The bottle 1 was a flat bottle having an internal capacity of 400 (grams), and the rib depth to be formed was d = 1 mm. The lower limit of the rib position L ₇ is L ₃ = 15 mm (−15 mm), and toward the reference position Lo, L ₅ = 10 mm (−10 mm), L ₁ = 5 mm (−5 mm), and The upper limit values were L ₄ = 15 mm (+15 mm), L ₂ = 5 mm (+5 mm), and L ₆ = 10 mm (+10 mm).

  In addition, the bending strength is indicated by a limit value (N) at which the waist deepest portion 4a does not cause the oblique ellipse to change, and when the rib deepest portion 7a matches the waist deepest portion 4a. The ratio (%) with respect to the limit value (N) is shown.

As is clear from Table 1, when the rib 7 is arranged so that the waist deepest portion 4a coincides with the rib deepest portion 7a, the lower limit of setting the reference position Lo as the waist deepest portion 4a. In the range from the value L ₃ (= −15 mm) to the upper limit value L ₄ (= + 15 mm) (L ₃ ≦ L ₇ ≦ L ₄ ), in particular, the lower limit value L ₁ (= −5 mm) to the upper limit value L ₂ If it is within the range up to (= + 5 mm) (L ₁ ≦ L ₇ ≦ L ₂ ), a high bending strength of 90% or more of the bending strength obtained when the waist deepest portion 4a and the rib deepest portion 7a are matched. Strength can be obtained.

  Furthermore, the graph which analyzed in detail the relationship between a rib position, buckling strength, etc. is shown in FIG.

As is apparent from FIG. 6, the rib deepest portion 7a is particularly within the range (L ₁ ≦ L ₀ ≦ L ₂ ) from the lower limit value L ₁ (= −5 mm) to the upper limit value L ₂ (= + 5 mm). If it is within the range (L ₁ ≦ L ₀ ≦ L ₂ ) from the lower limit L ₇ (= −2 mm) to the upper limit L ₈ (= + 5 mm), the waist deepest part 4a and the rib deepest part 7a are made to coincide. A high bending strength close to the bending strength obtained at the time can be obtained.

<Natural degradation test>
When the bottle 1 of the present invention was subjected to a natural decomposition test according to the composting test (JIS K6953: 2000), sufficient natural decomposition was confirmed.

<Seasoning filling bottle>
A bottle 1 at rib position 0 shown in Table 1 was filled with 400 g of canola oil, and a label was attached to the waist using a labeler to produce a seasoning-filled bottle. There was no abnormality such as deformation in the bottle.

  The bottle according to the present invention can be used in the food field such as seasonings and beverages containing edible oil, and in the cosmetic field such as shampoo and rinse.

(a), (b) is the front view and side view which respectively show the bottle which is one form of this invention. (a)-(c) is respectively AA sectional drawing, BB sectional drawing, and bottom view of Fig.1 (a). (a), (b) is the principal part sectional view which expands and shows the rib which concerns on the same form, respectively, and a cross-sectional view which shows the deformation | transformation state in the waist part. (a) to (c), respectively, according to the present invention, a form in which a rib is provided at a position below the deepest part of the waist, a form in which the rib is provided at a position where the deepest part of the rib coincides with the deepest part of the waist, and It is a perspective view which shows typically the form which provided the rib in the position above the waist deepest part. (a), (b), respectively, according to the present invention, a front view schematically showing the positional relationship with the deepest part of the waist when the rib is disposed, and an enlarged view of the vicinity of the deepest part of the waist in FIG. FIG. 6 is an enlarged view of a main part schematically showing the relationship with the position of a rib 7. It is the analysis figure which analyzed in detail the relationship between a rib position, buckling strength, etc., and showed it as a graph.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bottle 2 Mouth part 3 Bulging part 3a Maximum bulging part 4 Waist part 4a Waist deepest part 4b Trunk hem part 4c Decompression absorption panel 4d Part of waist part which forms a rib 4e Rib (one of the waist part which forms a rib) Part) 5 bottom part 7 rib 7a rib deepest part

Claims (6)

A bottle having a bottom portion having a ground contact surface and formed by biaxially stretching blow molding a resin containing polylactic acid,
The bottle has an elliptical cross-sectional shape, and has a bulging portion at the top of the bottle, and a waist portion that is constricted inward from the bulging portion below the bulging portion. And forming
A bottle comprising an annular rib that circulates around the axis of the bottle at a predetermined position including the deepest portion of the waist.   2. The bottle according to claim 1, wherein the predetermined position exists in a range of 8 mm to 5 mm from the deepest portion in a range extending in the vertical direction along the axis of the bottle.   The rib is an annular recess in which a recess curved toward the inside of the bottle is made to circulate around the axis of the bottle, and each end of the recess is a curved surface connected to the waist part excluding the recess. The bottle according to claim 1 or 2, characterized by the above.   The bottle according to any one of claims 1 to 3, wherein the bulging portion at the top of the bottle has a dome shape.   A bottle filled with a seasoning in the bottle according to claim 1.   The bottle according to claim 5, wherein the seasoning is an edible oil.

Images