JP4953674B2 - Plastic bottle - Google Patents

Description

  The present invention relates to a synthetic resin bottle filled with a liquid content such as a beverage.

  2. Description of the Related Art A biaxial stretch blow molded bottle (PET bottle) made of, for example, polyethylene terephthalate is known as a content-filling bottle that contains a liquid content such as a beverage.

  In this type of bottle, for heat sterilization, a beverage heated to a high temperature (for example, about 85 ° C.) is filled, and the mouth is sealed with a cap and then cooled. According to this, the inside of a bottle will be in a pressure-reduced state with the volume reduction of the drink by cooling. At this time, the body of the bottle may be deformed by the reduced pressure in the bottle, which is not preferable in appearance.

  For this reason, in a synthetic resin bottle filled with a liquid content at a high temperature, it is carried out to form a plurality of flexible panels in the body portion that uniformly absorb deformation caused by internal decompression (for example, Patent Document 1). However, when such a panel is provided, a large number of concave and convex shapes are required on the bottle body, which not only complicates the mold shape but also requires a relatively large amount of material. Will increase.

  Therefore, after the bottle bottom is provided with a reversing part that can be turned upside down, and the reversing part protrudes outward from the body, the heated liquid content is filled and the bottle mouth is sealed with a cap. In addition, there has been known one in which an inverted portion in a protruding state is inverted and recessed inward of a bottle during decompression by cooling (see Patent Document 2).

In the bottle described in Patent Document 2, prior to filling the liquid content, the upper pusher rod is extended from the bottle mouth portion toward the inside of the bottle, and further, the inner central portion of the bottle bottom is pushed down by the upper pusher rod. Is done. Thereby, the inversion part of the bottom of the bottle is inverted and protrudes outward and downward from the body part. Then, the upper pusher rod is pulled out from the inside of the bottle, and the heated liquid content is filled inside the bottle with the inverted portion at the bottom protruding outward and downward from the barrel, and then the bottle mouth is covered with a cap. Seal. After that, when the liquid content inside the bottle cools and is in a decompressed state, the bottom pusher rod is pushed up from the bottom to the center of the lower outer surface of the bottle bottom, and the bottle bottom in a state of protruding downward from the barrel is inverted. The part is recessed and inverted in the inner direction of the body part. As a result, the internal pressure in the reduced pressure state is canceled out, and the decompression deformation of the body portion of the container does not occur. In this way, by providing a reversing part that can be freely reversed on the bottom of the bottle and reversing the reversing part in the liquid content filling line, the bottle body can absorb the above-described deformation evenly. There is no need to provide a panel, the degree of freedom in bottle design is improved, and the material cost of the bottle can be reduced.
JP-A-6-72423 Special table 2006-501109

  However, in the bottle described in Patent Document 2, when the reversing part of the bottom part is reversed in the liquid content filling line, the upper pusher rod and the lower pusher rod are brought into contact with the center part of the bottom part, and when the reversing part is reversed. Stress is concentrated. Usually this type of bottle is blow molded from an injection molded preform. There are two types of preforms, one with the gate mark formed at the center of the bottom of the bottle at the time of injection molding and the other with no gate mark as with the so-called compression preform. Also in a thing, it is extended from the center part of a bottle bottom part to the bottom outer peripheral direction at the time of blow molding, and the intensity | strength with respect to an external force becomes comparatively low. In particular, in a preform formed in a portion where the gate mark becomes the central part of the bottom of the bottle, the strength is significantly reduced by the gate mark being stretched. For this reason, when the upper pusher rod or the lower pusher rod is brought into contact with the center of the bottom when the reversing portion is reversed, the contact portion may be damaged.

  Also, in this type of bottle, after the cap is fitted to the mouth and the inversion part of the bottom part is in a recessed state, the inversion part protrudes downward inadvertently, for example, when the bottle is dropped. It is necessary to reliably maintain the recessed state of the reversing part so as not to come out. For this reason, it is conceivable that the reversing portion has a shape with a relatively large resistance at the start of reversal, but this also requires a large pressing force by the upper pusher rod and the lower pusher rod. The stress concentrated at the center of the bottom where the upper pusher rod and the lower pusher rod come into contact with each other is undesirably large.

  The present invention has been made in view of the above-described problems, and it is possible to reliably prevent damage to the bottom portion when the reversing portion is reversed by increasing the strength of the bottom center portion, and to easily reverse the reversing portion. And providing a synthetic resin bottle that can reliably maintain the recessed state of the reversing part inside the body part after sealing the liquid content inside To do.

In order to achieve this object, the present invention provides a synthetic resin bottle comprising a mouth, a cylindrical body biaxially extended below the mouth, and a bottom that closes the bottom of the body. a is, the bottom portion is provided with a leg portion having a ground plane formed by continuously to the lower end of the body portion annularly, and a reversing portion provided continuously to the inner periphery of the leg portion, bottom center The reversing part is recessed by pushing the pusher rod into contact with the part, and the reversing part is extended together with the body part and the leg part, and is symmetrically shaped from the inside of the body part to the outside of the body part. An inclining portion that can be turned up and down, and an inward portion that is located at the center of the bottom of the region surrounded by the inclined portion, rises from the inner peripheral edge of the inclined portion, protrudes into the body, and has a flat top a protrusion, located on top of the inner side protruding portion, the inclined portion than the thickness dimensions larger E Bei a thick portion that is, the thickness dimension of the peripheral wall of the inwardly projecting portion is smaller than the thickness dimension of the inclined portion, the thick portion is smaller in diameter than the top portion of the inwardly projecting portion It is characterized by.

  The synthetic resin bottle of the present invention is provided with the inclined portion at the reversing portion at the bottom thereof, so that a part of the bottom portion can be reversed in an inward and outward direction of the body portion. It has become. By reversing the inclined part of the reversing part, the high temperature liquid content is filled in the bottle in a protruding state below the barrel part, and the reversing part is sealed by fitting a cap on the bottle mouth part. It is possible to eliminate the decompressed state inside the bottle simply by pushing up the inside of the barrel and reversing the recess.

Here, when to be recessed inward of the body portion of the inverted portion by inverting the inclined portion, the synthetic resin bottle of the present invention, Ri by the fact that comprises the thick portion in the bottom center portion, flop Tsu Shah rod Even if a mechanical pressing force is applied that pushes up from below the bottom center, damage to the bottom center can be reliably prevented. In general, synthetic resin bottles are formed from injection-molded preforms by biaxial stretch blow molding, but when preforms are injection-molded, gate traces are formed at positions corresponding to the bottom center of the bottle. In the present invention, the thick portion can be easily formed using this gate mark. On the other hand, even when a preform that does not cause gate marks (so-called compression preform) is used, it can be easily thickened by appropriately setting the thickness of the bottom of the preform or the heating conditions during blow molding. The part can be formed.
Moreover, in this invention, even if it is in the state which the said inclination part protruded in the outer side lower part of the trunk | drum, it will be in the state where the inward protrusion part was dented toward the bottle inward. And, by providing the thick part at the top of the inward projecting part, when the thick part is pushed up from the bottom toward the inside of the bottle, the pushing force is efficiently applied to the inclined part through the inward projecting part. It is possible to transmit well, and the reversing part can be recessed and reversed well inside the body part with a relatively small push-up force. Thereby, even if a mechanical pressing force is applied to the thick part from below the bottom center part, the burden on the thick part can be reduced, and damage to the bottom part center part can be more reliably prevented.
At this time, since the wall thickness of the peripheral wall of the inward projecting portion is smaller than the wall thickness of the inclined portion, an increase in the synthetic resin material forming the bottom can be suppressed.

  Moreover, in this invention, it is preferable that the thickness dimension of the said thick part is at least 1.2 times the thickness dimension of the said inclination part. Thereby, sufficient thickness can be ensured in the thick part of the bottom center part of the bottle, and the strength of the bottom center part can be improved reliably.

  Further, the inward projecting portion may be provided with a plurality of ribs extending in the height direction on the peripheral wall, or the peripheral wall of the inward projecting portion may be formed in a polygonal shape in plan view. Thereby, the intensity | strength of an inward protrusion part can be improved.

  Moreover, in this invention, it is preferable that the thickness dimension of the said inclination part is 0.2 mm-1.0 mm. If the thickness of the sloped part is less than 0.2mm, the strength of the sloped part will be insufficient, and the bottom will protrude outwardly in the handling of the filling process and subsequent distribution process. May be reversed. Further, if the thickness of the inclined portion is larger than 1.0 mm, the load when the inclined portion is reversed is too large, and a load may be applied to the thick portion when a pressing force is applied to the bottom center portion. There is. Therefore, according to the present invention, by setting the thickness of the inclined portion to 0.2 mm to 1.0 mm, the burden on the thick portion can be reduced and the reversing portion can be easily reversed. At the same time, inadvertent inversion of the inversion part can be reliably prevented.

  In the present invention, the inclined portion preferably has a draw ratio of at least 1.5 times. When the draw ratio of the inclined portion is lower than 1.5 times, the strength as the bottom portion of the inclined portion is insufficient, and unnecessary deformation may occur in the inclined portion, and the inclined portion may not be smoothly reversed. Therefore, in the present invention, by setting the stretch ratio of the inclined portion to at least 1.5 times, unnecessary deformation of the inclined portion can be suppressed and the reversal can be performed smoothly.

  Further, in the present invention, the inclined portion is inclined with respect to the ground contact surface of the leg portion when the inversion portion is recessed toward the inner side of the trunk portion, or when the inclined portion is recessed toward the inner side of the trunk portion. The angle is 15 ° to 45 °.

  When the inclination angle of the inclined portion is smaller than 15 °, the inclined portion can be reversed with a relatively small force, while the inclined portion is recessed into the inner portion of the inverted portion by the inclined portion or the outer portion of the outer portion. The protruding state cannot be maintained, and there is a risk of inadvertent reversal. In addition, the change in the capacity of the bottle accompanying the reversal of the unevenness of the reversing portion is also reduced, and the reduced pressure state inside the bottle may not be sufficiently eliminated. In addition, when the inclination angle of the inclined portion is larger than 45 °, the inclined portion can be reliably maintained in a state where the inversion portion is recessed into the body portion or protruded outward from the body portion, while the inclined portion is reliably inclined. A relatively large force is required when reversing, and there is a possibility that a load is applied to the thick portion when a mechanical pressing force is applied to the central portion of the bottom.

  In view of this, the present invention makes it easy to invert the inclined portion while obtaining a change in the capacity of the bottle that can sufficiently eliminate the reduced pressure state inside the bottle by setting the inclination angle of the inclined portion to 15 ° to 45 °. The burden on the meat part can be reduced, and in addition, the indented state inside the trunk part or the protruding state outward from the trunk part can be reliably maintained by the inclined part to prevent inadvertent reversal.

  In the present invention, the inclined portion is constituted by a plurality of hollow lines extending substantially radially and a plurality of panel surfaces arranged in the circumferential direction of the inclined portion via the hollow lines. And

  As for the said inclined part, the outer peripheral edge is controlled by the leg part over the perimeter, and, thereby, bending arises at the time of a reversal start. If the deflection at this time remains after being indented inwardly or protruding outwardly from the trunk, it is not preferable in terms of appearance due to the deformation of the bottom, but the thickness that should be in the center of the bottom There is a possibility that the meat portion is displaced from the axis of the bottle, and the pusher rod or the like may not be brought into contact with the thick portion with high accuracy during reversal. Therefore, the present invention is configured by forming the inclined portion with a plurality of hollow lines extending substantially radially and a plurality of panel surfaces between the respective hollow lines, so that even if a plurality of panel surfaces bend at the start of inversion, a plurality of It is possible to quickly eliminate the bending at the start of the reversal when it is absorbed by the hollow line and becomes indented inwardly of the body or protruded outwardly of the body. Thereby, the position shift of the thick part from the axial center position of the bottle can be prevented, and the pressing force at the time of reversal can be efficiently applied to the thick part and the burden on the thick part can be reduced.

  Moreover, in this invention, the said inversion part may be formed so that the capacity | capacitance change accompanying the inversion may be 1 to 10% with respect to a bottle total capacity | capacitance when it is in a recessed state toward the trunk | drum inside. it can. Specifically, by setting the size of the inclined portion constituting the reversing portion to be relatively large, it is possible to cope with a case where the pressure reduction of the body portion is large, and the inclination constituting the reversing portion. By setting the size of the part relatively small, it is possible to cope with a case where the pressure reduction of the body part is small.

  Further, in the bottle of the present invention, the inclined portion may be formed to be inclined toward the inside of the trunk portion (that is, formed in a state where the inversion portion is recessed inward of the trunk portion). The inclined portion may be formed to be inclined toward the outside of the body portion (that is, formed so that the inversion portion protrudes outward from the body portion).

  Further, the inclined portion may be formed so as to be inclined toward the inside of the body portion by being inverted after being blow-molded into a shape inclined toward the outside of the body portion. In this case, since the inclined portion is blow-molded toward the outside of the body portion, the inclined portion can be sufficiently extended.

  Moreover, in the bottle of this invention, the said leg part and the inversion part may be heat set. Since heat resistance can be imparted by performing heat setting on the leg portion and the reversing portion, for example, the bottle of the present invention is filled with a so-called hot pack type filling and sealing with heated liquid contents. It can be made suitable.

  An embodiment of the present invention will be described with reference to the drawings. 1A and 1B are explanatory views of the synthetic resin bottle of the present embodiment as viewed in a longitudinal section, FIG. 2 is an explanatory view of the synthetic resin bottle of the present embodiment as viewed from the bottom, and FIG. 3 is the present embodiment. FIG. 4A and FIG. 4B are explanatory views showing the push-down operation of the reversing part, and FIGS. 5A and 5B are views of the reversing part. FIG. 6 is an explanatory diagram showing another shape of the inward projecting portion.

  As shown in FIG. 1A, the synthetic resin bottle 1 according to the present embodiment includes a mouth portion 2, a cylindrical body portion 3 continuously provided below the mouth portion 2, and the body portion 3. And a bottom portion 4 for closing the lower portion. The bottle 1 is biaxially stretched and blow-molded from a preform (not shown) made of an injection-molded polyethylene terephthalate resin, whereby the body portion 3 and the bottom portion 4 are formed in a biaxially stretched state. Moreover, the bottle 1 of the present embodiment is heat set to impart heat resistance. Note that the mouth portion 2 is already crystallized in a preform state and imparted heat resistance. A screwing portion 5 for screwing a cap (not shown) is formed on the outer periphery of the mouth portion 2, and a flange portion 6 is formed on the lower portion of the screwing portion 5 so as to project to the outer periphery.

  Next, the bottom part 4 of the synthetic resin bottle 1 of this embodiment will be described in detail. As shown in FIGS. 2 and 3, the bottom portion 4 includes an annular leg portion 7 formed continuously at the lower end of the body portion 3, and an inversion portion 8 formed in a region surrounded by the leg portion 7. It has. The leg portion 7 includes an annular grounding surface 9, and the grounding surface 9 can be grounded so that the bottle 1 can be stably supported.

  The inversion part 8 is connected to the inner peripheral edge of the leg part 7 via the first hinge part 10 and is connected to the inner peripheral edge of the inclination part 11 via the second hinge part 12. And an inward protruding portion 13.

  The inclined portion 11 is formed in a generally conical shape that is inclined inwardly from the first hinge portion 10 to the second hinge portion 12 toward the center portion of the bottom portion 4. The inclination angle θ of the inclined portion 11 is about 30 ° (preferably 15 ° to 45 °) with respect to the ground contact surface 9 of the leg portion 7, and is about 6 times (at least 1.5) when the bottle 1 is blow molded. The draw ratio is preferably 2). The inclined portion 11 has a thickness dimension of about 0.5 mm (preferably 0.2 mm to 1.0 mm), and includes a plurality of hollow lines 14 that extend substantially radially and a panel surface 15 between the hollow lines 14. It is configured. Furthermore, when heat resistance is imparted to the bottle 1, a heat setting process is performed.

  The inward protruding portion 13 rises from the inner peripheral edge of the inclined portion 11 via the second hinge portion 12 and protrudes into the trunk portion 3 (indented when viewed from the outside), and has a generally conical shape with a flat top portion. Is formed. Further, the center of the top portion of the inward protruding portion 13 substantially coincides with the axis of the bottle 1 (that is, the center of the bottom portion 4), and the thickness of the top portion of the inward protruding portion 13 is about 0.65 mm ( A thick portion 16 is preferably formed which is preferably at least 1.2 times the thickness of the inclined portion 11. The thick portion 16 can be easily formed by utilizing a gate mark at the time of injection molding of a preform. The peripheral wall 17 of the inwardly projecting portion 13 has a plurality of ribs 18 that have the same or thin wall thickness as the inclined portion 11 and extend in the height direction.

  Further, the size of the inward protruding portion 13 can be appropriately selected according to the outer diameter of the bottom portion 4. If the preferable range is mentioned, the diameter of the top part of the inward protrusion part 13 and the lower end edge of the surrounding wall 17 with respect to the diameter of the bottom part 4 can all be selected in the range of 10%-40%. Furthermore, the inward protrusion 13 can be appropriately selected in height according to the inner volume of the bottle 1. If the preferable range is mentioned, when the internal volume of the bottle 1 is 200 ml-2000 ml, the height dimension (height from the lower end edge of the surrounding wall 17 to the top part) of the inward protrusion part 13 which can be selected is 2 mm-20 mm. You can select by range.

  The bottom part 4 of the bottle 1 formed as described above is configured such that the inversion part 8 can protrude downward from the bottle 1 as shown in FIG. That is, when the reversing part 8 protrudes below the body part 3 as shown in FIG. 1B from the state in which the reversing part 8 is recessed in the body part 3 as shown in FIG. 4 (a), the upper pusher rod 19 is abutted against the inward projecting portion 13 from the inside of the body portion 3 and the bottom portion 4 is pushed down. As a result, the inclined portion 11 is inverted into a symmetrical shape via the first hinge portion 10 as shown by the phantom line in FIG. 3, and protrudes below the trunk portion 3 as shown in FIG. .

  At this time, since the thick portion 16 is formed on the top portion of the inward projecting portion 13, even if the upper pusher rod 19 comes into contact, the bottom portion 4 central portion is not damaged, and the bottom portion 4 can be surely pushed down. it can. Further, the second hinge portion 12 at the outer peripheral edge (the lower end edge of the peripheral wall 17) of the inward projecting portion 13 is bent outwardly in an arc shape and an acute angle, and the inward projecting portion 13 is not inverted and is not inverted. The protruding state is maintained. As a result, the pressing force by the upper pusher rod 19 can be received in a relatively wide range, and the pressing force by the upper pusher rod 19 is prevented from concentrating on the central portion of the bottom portion 4 and the burden on the thick portion 16 is reduced. Can be reduced. Moreover, since the rib 18 is provided on the peripheral wall 17 of the inward projecting portion 13, the peripheral wall 17 of the inward projecting portion 13 is also strong, so that the pressing force by the upper pusher rod 19 can be reliably ensured. It can be transmitted to the inclined portion 11. Further, even when the inclined portion 11 is bent at the time of starting reversal, the stress can be distributed to each panel surface 15 by being absorbed by the plurality of hollow lines 14 extending substantially radially, so that the pressing force at the time of reversing Can be efficiently applied to the thick portion 16, and the burden on the center portion of the bottom portion 4 can be reduced. Furthermore, since the inclination angle θ of the inclined portion 11 is about 30 ° with respect to the ground contact surface 9 of the leg portion 7, the inclined portion 11 can be reversed with a relatively small pressing force, and this also causes the bottom portion to be reversed. 4 is reduced, and the protruding state of the reversing portion 8 due to the reversal of the inclined portion 11 can be reliably maintained.

  When the reversing portion 8 is recessed inward of the trunk portion 3 as shown in FIG. 1A from the state in which the reversing portion 8 protrudes from the trunk portion 3 as shown in FIG. As shown in FIG. 5A, the bottom pusher rod 20 is abutted against the inside of the inward projecting portion 13 from below the bottom portion 4 to push up the bottom portion 4. This operation is performed after the liquid content is filled in the bottle 1 and sealed with a cap. As a result, the inclined portion 11 is inverted toward the inside of the body portion 3 via the first hinge portion 10 and is recessed into the inside of the body portion 3 as shown in FIG. Accordingly, the inward projecting portion 13 maintains a state of projecting into the body portion 3, and the second hinge portion 12 at the outer peripheral edge (the lower end edge of the peripheral wall 17) of the inward projecting portion 13 is bent at an acute angle. Is released.

  At this time, since the thick portion 16 is formed on the top portion of the inward projecting portion 13, even if the lower pusher rod 20 comes into contact, the bottom portion 4 central portion is not damaged, and the bottom portion 4 can be surely pushed up. it can. Further, the push-up force of the lower pusher rod 20 is evenly transmitted over the entire inner periphery of the inclined portion 11 via the inward projecting portion 13, and the inclined portion 11 can be inverted and recessed with a relatively small push-up force. . Thereby, the burden on the thick part 16 can be reduced, and damage to the central part of the bottom part 4 can be reliably prevented. Similarly to the case where the reversing portion 8 is projected, even if the inclined portion 11 is bent at the time of reversing, the stress is absorbed by each of the panel surfaces 15 by being absorbed by the plurality of hollow lines 14 extending substantially radially. Therefore, the pressing force at the time of reversal can be efficiently applied to the thick portion 16 and the burden on the center portion of the bottom portion 4 can be reduced. Furthermore, since the inclination angle θ of the inclined portion 11 is about 30 ° with respect to the ground contact surface 9 of the leg portion 7, the inclined portion 11 can be reversed with a relatively small pressing force, and the center of the bottom portion 4 can be reversed. The burden on the part is reduced and the recessed state of the reversing part 8 is reliably maintained.

  In the present embodiment, an example in which a plurality of ribs 18 are provided on the peripheral wall 17 of the inward projecting portion 13 has been described. However, the ribs 18 are not provided in addition to the inner walls as shown in FIG. The peripheral wall 17 of the protrusion 13 may be formed in a polygonal shape in plan view.

  Further, when the bottle 1 of this embodiment is used for so-called hot pack type filling in which the heated liquid content is filled and sealed, the inside of the bottle 1 is reduced in pressure by the reversing unit 8 as the temperature of the liquid content decreases. Although it can be eliminated by recessing, it is not limited to this, and even when used for so-called aseptic filling in which liquid content is filled and sealed at room temperature, the liquid content is cooled at low temperature. It is possible to eliminate the relatively small pressure reduction in the bottle 1 due to. That is, with reference to FIG. 3, when the bottle 1 is used for aseptic filling, the diameter of the first hinge portion 10 is reduced and the position is changed to the inside of the bottom portion 4 to change the inclined portion. The capacity of the bottle 1 associated with the inversion of the inversion part 8 is reduced by reducing the width of the eleventh part (the interval between the first hinge part 10 and the second hinge part 12) or by reducing the angle of the inclined part 11 with respect to the ground plane 9. Change should be small. With this method, the change in the capacity of the bottle 1 accompanying the reversal of the unevenness of the reversing unit 8 can be easily changed within a range of 1% to 10% with respect to the total capacity of the bottle 1. When the bottle 1 is used for aseptic filling, the bottle 1 need not be heat set.

  In addition, the bottle 1 of the present embodiment is formed by blow molding using a blow mold (not shown). By the blow molding, as shown in FIG. It can be formed to be inclined toward the direction (that is, the reversing part 8 is formed in a state of being recessed inward of the body part 3). Alternatively, as shown in FIG. 1B, the inclined portion 11 is formed to be inclined toward the outside of the body portion 3 (that is, the reversal portion 8 protrudes outward from the body portion 3 by blow molding). Can be formed).

  Furthermore, the bottle 1 of the present embodiment is first formed in the blow mold in a state in which the reversing portion 8 protrudes outward from the body portion 3 as shown in FIG. 1 is sufficiently stretched, and thereafter, in the blow mold or outside the blow mold, as shown in FIG. 1 (a), the reversing part 8 forms the bottle 1 recessed into the body part 3 inward. Good.

Explanatory drawing which looked at the synthetic resin bottle of one Embodiment of this invention in the longitudinal cross-section. Explanatory drawing which looked at the bottom of the synthetic resin bottle of this embodiment. Cross-sectional explanatory drawing which expands and shows the bottom part of the synthetic resin bottles of this embodiment. Explanatory drawing which shows the pushing-down operation | work of an inversion part. Explanatory drawing which shows the pushing-up operation | work of an inversion part. Explanatory drawing which shows the other shape of an inward protrusion part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Plastic resin bottle, 2 ... Mouth part, 3 ... Body part, 4 ... Bottom part, 7 ... Leg part, 8 ... Inversion part, 9 ... Ground surface, 11 ... Inclination part, 13 ... Inward protrusion part, 14 ... A hollow line, 15 ... panel surface, 16 ... thick part, 17 ... peripheral wall, 18 ... rib.

Claims (13)

A mouth, a cylindrical body portion that is biaxially stretched below the the mouth portion, a synthetic resin bottle comprising a bottom portion which closes a lower portion of the body portion,
The bottom portion includes a leg portion having a ring-shaped grounding surface that is connected to the lower end of the body portion, and a reversing portion that is connected to the inner periphery of the leg portion, and a pusher rod at the bottom center portion. In what the inversion part is recessed by abutting and pushing up,
The reversing part extends along with the body part and the leg part, and is provided with an inclined part that can be reversed in a symmetrical shape toward the inside of the body part or outward of the body part, and a central part of the bottom part in the region surrounded by the inclined part. An inward protruding portion that is positioned and rises from the inner peripheral edge of the inclined portion, protrudes into the body portion and has a flat top portion, and is positioned on the top portion of the inward protruding portion and is thicker than the inclined portion. There example Bei and a thick portion, which is a large,
The wall thickness of the peripheral wall of the inward protruding portion is smaller than the wall thickness of the inclined portion,
The thick-walled portion has a smaller diameter than the top of the inward protruding portion .   The synthetic resin bottle according to claim 1, wherein the thickness of the thick portion is at least 1.2 times the thickness of the inclined portion. The synthetic resin bottle according to claim 1 , wherein the inward protruding portion includes a plurality of ribs extending in a height direction on a peripheral wall thereof. The synthetic resin bottle according to claim 1 or 2 , wherein the inwardly projecting portion has a peripheral wall formed in a polygonal shape in plan view. The synthetic resin bottle according to any one of claims 1 to 4, wherein a thickness of the inclined portion is 0.2 mm to 1.0 mm. The synthetic resin bottle according to any one of claims 1 to 5, wherein the inclined portion has a draw ratio of at least 1.5 times. 7. The inclined portion according to claim 1 , wherein an inclination angle of the leg portion with respect to a ground contact surface is set to 15 ° to 45 ° when the inversion portion is recessed toward the inside of the trunk portion. The synthetic resin bottle according to any one of the above . The said inclined part is comprised by the several panel surface arranged in the circumferential direction of this inclined part via the several hollow line extended substantially radially, and each hollow line, The 1st thru | or characterized by the above-mentioned. The synthetic resin bottle according to any one of 7 . The reversing unit, wherein the capacitance change accompanying the inversion, characterized in that it is formed so as to be 1-10% with respect to the bottle full capacity when in the recessed state toward the cylinder portion side Item 9. A synthetic resin bottle according to any one of Items 1 to 8 . The synthetic resin bottle according to any one of claims 1 to 9, wherein the inclined portion is formed to be inclined toward an inner side of the body portion. Claim 1, wherein the inclined portion, characterized in that it is formed to be inclined toward the inside of the body by being reversed after being blow molded into a shape that inclines toward the outside of the body portion The synthetic resin bottle of any one of thru | or 9 . The synthetic resin bottle according to any one of claims 1 to 9, wherein the inclined portion is formed to be inclined toward the outside of the body portion. The synthetic resin bottle according to any one of claims 1 to 12, wherein the leg portion and the reverse portion are heat-set.

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