JP2727934B2 - Vacuum absorbent polyester bottle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum-absorbing polyester bottle, particularly to a polyester bottle with a handle, and more particularly, to irregularity after hot-filling (hot-packing) the contents. The present invention relates to a polyester bottle in which asymmetric decompression deformation is effectively prevented by providing a partial decompression absorption surface.

[0002]

2. Description of the Related Art Plastic hollow containers are widely used as packaging containers for various liquids because of their excellent lightness and impact resistance. In particular, polyethylene terephthalate (PET) is stretch blow-molded. The hollow container consists of transparency, gas barrier properties, light weight, impact resistance,
It has a combination of appropriate rigidity and the like, and is widely used as a packaging container for containing liquid contents.

[0003] In order to enhance the preservability of the contents, hot filling of the contents is widely performed also in polyester bottles. However, due to the volume shrinkage of the contents due to cooling, the container must be deformed under reduced pressure. Occurs. In order to prevent this, a panel is provided on the side wall of the bottle via a pillar,
The panel section absorbs the reduced pressure deformation.

In order to improve the heat resistance of PET containers, it has been widely used to heat-fix a biaxially stretched blow-molded container. And shape stabilization is common.

[0005]

In the above prior art,
In a bottle in which the decompression absorption panels are provided almost uniformly over the entire circumference of the container body, even if the absorption of the decompression due to the reduction in the volume of the contents is performed relatively smoothly, the decompression absorption is performed. In the case of a bottle in which a panel is provided partially on the body of the container, the reduced pressure cannot be absorbed only by deformation of the panel, and unintended portions may be irregularly or asymmetrically deformed.

[0006] The situation in which a reduced pressure absorbing panel cannot be provided over the entire body of the container is caused when a separate handle is provided on the bottle or when a label for displaying an internal substance is provided. Occurs.

For example, in the case of a large stretch blow-molded container, it is required to attach a handle because of its easy handling. Because it is difficult in principle,
Several proposals have been made for attaching handles to stretch blow molded containers.

However, in the case of a polyester bottle with a handle, the shrink volume is large because the bottle volume is large.
In addition, since the bottle has an asymmetric structure due to the provision of the handle, there is a problem that the shrinkage and deformation of the bottle are large and the bottle is likely to be irregular or asymmetric (a concave and concave shape).

[0009] Even in a container with a label, if such irregular deformation occurs in the label, the commercial value of the bottled product is remarkably reduced. Therefore, it is necessary to disperse and absorb the shrinkage deformation on the container wall so as not to be conspicuous. Is important.

Further, in the bottle with a handle, if such a deformation occurs in the attachment portion between the handle and the bottle, the fixation between the handle and the bottle becomes incomplete, and when the handle is rattled or severe. May be detached, and cracks or the like may be generated on the container wall near the handle attachment portion, causing troubles such as leakage and reduced strength.

Accordingly, it is an object of the present invention to provide a polyester in which irregular or asymmetric pressure-reduction deformation after hot filling of contents is effectively prevented irrespective of the asymmetric structure of the body. In providing bottles made of plastic.

[0012] Another object of the present invention is to effectively absorb decompression deformation after hot filling of the contents in a fixed portion of the container wall, regardless of the asymmetric structure of the container body. It is another object of the present invention to provide a polyester bottle in which irregular deformation at a handle attaching portion or a label portion and cracks on a container wall at a boundary portion thereof are effectively prevented.

[0013]

According to the present invention, there is provided a bottle formed by stretch blow molding of a thermoplastic polyester and having a plurality of reduced pressure absorbing surfaces formed on a side wall in a convex shape, wherein ethylene is used as the thermoplastic polyester. A copolyester containing terephthalate as a main component is used, and the crystallinity of the side wall is maintained in a range of 15 to 30%.

As the polyester, it is preferable to use an ethylene terephthalate copolymerized polyester containing 1 to 3% of an isophthalic acid unit as an acid component.

According to the present invention, there is also provided a bottle with a handle provided with a bottle body formed by stretch blow molding of a thermoplastic polyester and a handle made of a thermoplastic resin separate from the bottle body. Provide a handle attachment portion and a label surface in the portion and on the trunk other than the handle attachment portion and the label surface, provide a plurality of reduced pressure absorbing surfaces via a connecting portion in a convex shape, and use ethylene terephthalate as the thermoplastic polyester. A copolyester as a main component is used, and the crystallinity of the body side wall is maintained in the range of 15 to 30%.

[0016]

The reduced pressure absorbent bottle of the present invention is formed by stretch blow molding of a thermoplastic polyester, and has a plurality of reduced pressure absorbing surfaces provided on the side walls in a convex shape. Ethylene terephthalate is used as the thermoplastic polyester. When the copolyester as a main component is used and the degree of crystallinity of the side wall is maintained in the range of 15 to 30%, even if the decompressed absorbing surface is provided asymmetrically on the body side wall, the decompressed absorbing surface is obtained. Thus, it is possible to effectively absorb the decompression due to the volume reduction of the contents, and it is possible to completely prevent irregularity or asymmetric deformation due to the decompression.

Hitherto, it has been considered effective to increase the crystallinity of the side wall of the container in order to prevent irregularity or asymmetric deformation of the polyester bottle due to reduced pressure.
In the present invention, maintaining the crystallinity of the side wall portion in a rather low range of 15 to 30% is more effective for reducing pressure absorption by inversion of the reduced pressure absorbing surface from a convex shape to a concave shape (buckling deformation). Was found.

In a bottle having a handle mounting portion and a label surface and a partially provided asymmetrical decompression absorption surface, the decompression absorption surface is buckled in response to the occurrence of decompression due to volume reduction of the contents. This sensitivity is closely related to the elastic properties of the side walls. In the present invention, the elastic properties of the side wall can be adjusted by adjusting the crystallinity of the polyester to the above range.

When the crystallinity of the side wall is lower than 15%, portions other than the reduced pressure absorbing surface are also easily deformed, causing irregular or asymmetric deformation of the container. Impact resistance, heat resistance, transparency, and the like also tend to decrease. If the crystallinity of the side wall portion exceeds 30%, the elasticity of the side wall becomes too large, so that the sensitivity of the buckling deformation of the reduced pressure absorbing surface to the generation of the reduced pressure becomes low, and irregular or asymmetric deformation of the container occurs. Become.

The crystallinity of the side wall portion of the vacuum absorbent polyester bottle of the present invention of 15 to 30% is based on the biaxial molecular orientation of the polyester, which is irregular or irregular due to a mechanism different from the above mechanism. Helps prevent simultaneous deformation. That is, when the contents are hot-filled in the bottle, the orientation and strain are relaxed by the heat, and the bottle shrinks. Due to the volume shrinkage of the bottle, some of the reduced pressure is absorbed, which also helps prevent irregular or asymmetric deformation.

It is not good to use polyethylene terephthalate as the thermoplastic polyester in order to suppress the crystallinity of the side wall portion within the range of 15 to 30%, and a copolymer polyester mainly composed of ethylene terephthalate units is used. Should. As a copolymerized polyester,
It is preferable to use an ethylene terephthalate copolymerized polyester containing 1 to 3% of an isophthalic acid unit as an acid component.

The present invention is particularly advantageously applied to a bottle provided with a handle mounting portion and / or a label surface on the body of the bottle. In this bottle, a plurality of decompression absorption surfaces are provided on the body other than the handle attachment portion and the label surface through a connecting portion with a convex shape, but irregularity or asymmetric deformation of the handle attachment portion and the label surface are prevented. Can be.

The handle mounting portion is an important part for securely fixing and engaging the handle and the bottle and for holding the bottle, while the label surface is used to securely identify the product name, type and source of the contents. It is an important part in displaying and increasing the commercial value of the bottled product. Irregularity or asymmetric deformation due to decompression of these parts is not allowed, but in the present invention, asymmetrical parts are provided on the parts other than the handle mounting part and label surface. Even when the reduced pressure absorbing surface is provided, since the buckling deformation sensitivity to the reduced pressure of the reduced pressure absorbing surface is excellent, it is possible to prevent irregularities or asymmetric deformation due to the reduced pressure of the handle mounting portion or the label surface.

In the present specification, the crystallinity of the polyester constituting the side wall is a crystallinity determined by a density method. More specifically, the density of the body is measured by a density gradient tube method.
The crystallinity X (%) is determined by the following equation.

(Equation 1) Where d is the measured density at 25 ° C (g / cm ³ ), da
= 1.335 g / cm ³ (density of completely amorphous polyester), dc
= 1.455 g / cm ³ (density of perfect crystalline polyester).

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION

[Structure of Bottle] A vacuum-absorbing polyester bottle of the present invention will be described with reference to the drawings with reference to a preferred label and a bottle with a handle.

FIG. 1 is a front view of an embodiment of a polyester bottle with a handle of the present invention, and FIG.
FIG. 3 is a rear view of the bottle of FIG. 4 is a top view of the bottle of FIG. 1, FIG. 5 is a bottom view of the bottle of FIG. 1, and FIG.
It is A sectional drawing. 7 and 8 are cross-sectional views taken along the line BB in FIG. 2. FIG. 7 shows an unfilled state, and FIG. 8 shows a state of reduced pressure after hot filling and sealing.

The polyester bottle of the present invention is shown in FIG.
As shown in FIG. 3 through FIG. 3, the bottle body is generally designated by 1 and the handle is designated by 2 as a whole. 1 to 6, the bottle body 1 includes a neck 3, a cylindrical body 4, and a closed bottom 5, and a frustum-shaped shoulder 6 exists between the neck 3 and the body 4.

The cylindrical body 4 is vertically divided into an upper body 7 and a lower body 8, and the upper body 7 is provided with a handle mounting portion 9. Is provided with a label surface 10.

As shown in FIGS. 2 and 3, the handle mounting portion 9 comprises a concave portion which is recessed from below the frustum-shaped shoulder portion 6 toward the center of the bottle. As viewed from the side, the handle mounting recess 9 hangs down from the shoulder and then extends slightly inclining toward the center of the bottle, the side surface 12 extending substantially vertically, and slightly inclining toward the side of the body. In the embodiment shown in the drawings, the concave side surface 12 has a maximum concave portion which is substantially the same as or slightly larger than the neck portion 3 in horizontal cross section (FIG. 6). ) Is provided in a substantially arc shape.

On the vertical side surface 12 of the recess 9 for attaching the handle,
As shown in FIG. 3 and FIG. 6, a projection indicated by 14 as a whole is provided. The protrusion 14 is formed so that its vertical cross section is non-circular, and in the embodiment shown in the drawings, it is oval, but it can prevent rotation of the handle in combination with the handle described later in detail. Any shape may be used as long as the shape is, for example, an ellipse, an oval, a triangle, a square,
It may be a pentagon or another polygon. The protrusions 14 are formed integrally with the handle mounting recess 9 and other parts of the bottle body by stretch blow molding, but as shown in the cross-sectional view of FIG. A portion 15, a flange portion 16 which is located at the distal end of the tubular portion 15 and which is increased in size in the transverse direction to form a flange, and a distal end surface 17 which is closed at the flange portion, are hollow inside. .

Further, as shown in the cross section of FIG. 6, a circumferential groove 18 is formed at the base of the projection 14, so that the handle 2 can be fixed more firmly.

As shown in FIGS. 2 and 3, the handle 2 of the bottle of the present invention is separate from the bottle, and is an endless grip 20 integrally formed by injection molding of synthetic resin.
And the mounting portion 21. The grip portion 20 has vertical portions 22 in which irregularities for preventing slippage are alternately arranged at small intervals inside, and is connected to a ring-shaped mounting portion 21 via an upper curvature portion 23 and a lower curvature portion 24. Have been. The ring-shaped mounting portion 21 has a shape similar to that of the bottle main body protrusion 14 and has an inner peripheral dimension substantially equal to the outer peripheral dimension thereof, and as shown in FIG. It is embedded so that the fixed engagement between the two is ensured.

The handle 2 is provided with a projection 25 for locking and stabilizing above the upper curvature portion 23 and a projection 26 for locking and stabilizing below the lower curvature portion 24. The handle attachment portion upper surface 11 and the handle attachment portion lower surface 13 are engaged with each other. From FIG. 3, it will be appreciated that the handle 2 does not substantially protrude beyond the outer surface of the bottle body.

In the present invention, the upper body 7 is provided with a plurality of reduced pressure absorbing surfaces 27 in the form of convex surfaces on the opposite side of the recess 9 for handle attachment to the vicinity of the handle attachment via the connecting portion 28. The decompression absorption surface 27 is generally a quadrilateral having an area, while the connecting portion is in the form of a narrow rib. As shown in FIG. 6, it is important for the decompression absorbing surface 27 to have a convex shape, that is, a shape in which the central portion protrudes radially outward in order to perform decompression absorption by buckling.

In a preferred embodiment of the present invention, of the plurality of reduced pressure absorbing surfaces 27, one 27a adjacent to the handle mounting recess 9 is
The upper part has a wide width and the lower part has a narrow width as a reduced pressure absorbing surface. The detailed structure of the reduced-pressure absorbing surface 27a will be better understood with reference to FIGS. As in the present invention, a handle mounting recess is formed, and in a container having an asymmetric structure, the weakest portion structurally during decompression deformation is a connection portion between the handle mounting recess where stress tends to concentrate and the decompression absorbing surface,
In particular, by introducing a reduced-pressure absorbing surface 27a having a wide width at the upper portion and a narrow width at the lower portion of the connection portion, stress distribution can be measured.

In the specific example shown in FIG.
Are provided on the front, these are compared to the upper side,
It is a long quadrilateral with a lower side. If the dimension in the width direction of the reduced-pressure absorbing surface 27 is small, the volume that can be absorbed by the deformation from the convex surface to the concave surface becomes small. Therefore, the width should be as large as possible without affecting the appearance and function of the bottle. is there.

As an example, when the internal capacity is 1.8 l, the average dimension in the width direction of the reduced-pressure absorbing surface 27 is preferably in the range of 40 to 60 mm, particularly 45 to 55 mm, while the central portion of the reduced-pressure absorbing surface 27 The ratio of the protrusion dimensions (protrusion height / width) from both ends is preferably in the range of 0.02 to 0.08, particularly 0.04 to 0.06. When the width and the protrusion ratio are smaller than the above ranges, the reduced pressure absorption is not sufficient. On the other hand, when the ratio is larger than the above range, asymmetric deformation occurs at the time of the reduced pressure absorption, and the appearance of the subsequent container deteriorates. It is preferable that the dimension in the height direction of the reduced-pressure absorbing surface 27 is equal to or larger than the dimension in the width direction.

The width of the connecting portion 28 is 1 to 5 mm,
In particular, it is preferably in the range of 2 to 3 mm. When the width is smaller than the above range, the shaping property of the reduced pressure absorbing surface is deteriorated. Become buckled.

It is effective to prevent the asymmetric deformation by connecting the connecting portion 28 and the shoulder portion 6 with each other at the apex as a cut surface or providing a relatively large radius. As an example, the size of R is preferably in the range of 6R to 12R.

In the present invention, the lower body 8 is also provided with the label surface 10.
A plurality of decompression absorbing surfaces 29 are provided on the opposite side to the convex shape and connected via the connecting portion 30, and the label surface 10 and the decompression absorbing surface 29 are provided.
Is provided with a protective bent portion 32 for preventing deformation of the label surface 10.

As in the case of the upper body 7, the reduced pressure absorbing surface 29
Is generally a quadrilateral with an area, while the connecting part 30 is in the form of a narrow rib. As shown in the cross-sectional view of FIG. 7, the decompression absorbing surface 29 has a convex shape, that is, a shape in which a central portion protrudes radially outward, and as shown in FIG. Decompression absorption occurs (this is the same for the decompression absorption surface 27 of the upper body 7).

As shown in FIG. 7, the protective bending portion 32
A curved portion that also serves as a step between the relatively large-diameter label surface 10 and the relatively small-diameter boundary portion 31, and has an outwardly convex curvature portion on the label surface 10 side and an inwardly convex portion on the boundary portion 31 side. Are obliquely connected to each other via the curvature section of the above.

The operation of the protective bend 32 is also shown in FIG. 8, and when the pressure is reduced, the protective bend 32 is depressed inward so that the label surface 10 projects radially outward. The balance is maintained by the force acting inside the diameter of the label 10, and the deformation of the label surface 10 is prevented.

In the specific example shown in the figure, three decompression absorption surfaces 29 of the lower body 8 are provided on the back surface, and these are right-angled quadrilaterals.

The reduced pressure absorbing surface 29 and the connecting portion 30 of the lower body 8
Is preferably in the same range as that of the upper body 7 for the reason described above. The dimensions of the protective bends 31 and 32 are such that the radial step is 2 to 6 mm, especially 3 mm.
5 to 5 mm, the total width on one side in the circumferential direction is 10 to 4
It is preferably in the range of 0 mm, especially 25 to 35 mm.

As shown in FIGS. 1 to 3, the handle mounting portion 9 of the upper body 7 and the label surface 10 of the lower body 8 are located on opposite sides. By doing so, when the label surface 10 is at the front, the handle 2 is at the back, and the handle 2 is hidden, which is aesthetically convenient.

In order to block the influence of the decompression deformation of the upper torso 7 and the lower torso 8, the handle mounting portion 9 of the upper torso 7 and the lower torso 8
A reinforcing step 33 is formed at the boundary between the pressure-absorbing surface 29 and the pressure-absorbing surface 27 of the upper body 7 and the label bead 34 at the boundary between the label surface 10 of the lower body 8. .

In the reinforcing step 33, the deformation of the decompression absorbing surface 29 of the lower body 8 is caused by the handle mounting portion 9 of the upper body 7, especially the lower surface 13,
It propagates to the vertical mounting surface 12 that follows it and prevents this from being dented. Further, the reinforcing beads 34 prevent the deformation of the decompression absorbing surface 27 of the upper body 7 from affecting the label surface 10 of the lower body 8.

The bottle of the present invention is used for hot filling an internal product and sealing it as it is. A screw 35 for opening and closing the cap, a step 36 for fastening the pill fur proof cap, and the like are provided on the neck 3 of the bottle in order to seal the internal contents. A support ring 37 for supporting is provided. Also,
The bottom 5 has a dome shape in which the center is higher than the ground contact surface, and the bottom 5 is provided with an engagement recess 38 for positioning the bottle and preventing its rotation.

The bottle described above has both a handle and a label surface. Of course, the present invention can be applied to a bottle having only one of a handle and a label surface. By being provided, it can be widely applied to other decompression-absorbing polyester bottles in which the decompression absorption surface is partially provided.

[Polyester] In the present invention, a copolymerized polyester mainly composed of ethylene terephthalate units is used as the thermoplastic polyester. The content of the ethylene terephthalate unit in the copolymerized polyester is preferably in the range of 1 to 5 mol%, particularly 2 to 4 mol%.

When the content of the ethylene terephthalate unit in the copolymerized polyester is more than the above range, the crystallinity of the molded bottle side wall tends to exceed 30%,
On the other hand, if it is less than the above range, the crystallinity of the bottle side wall tends to be less than 15%.

Examples of the copolymerization component include other glycols such as hexahydroxyrylene glycol, butanediol, and propylene glycol as a glycol component, and isophthalic acid, hexahydroterephthalic acid, and naphthalenedicarboxylic acid as a dibasic acid component. Other dibasic acid components are included.

Among these copolyesters, polyethylene terephthalate / isophthalate in which 1 to 3% of dibasic acid is isophthalic acid is useful for the purpose of the present invention. This isophthalic acid-modified polyester makes it easy to adjust the crystallinity of the side wall to the above-mentioned range without deteriorating the properties of the bottle, and furthermore, the bottle formed from this copolymerized polyester has a low content in the contents. It also has the additional advantage of excellent flavor retention without absorbing the flavor components.

The intrinsic viscosity (η) of the thermoplastic copolymer polyester used may be a bottle forming grade, and is 0.65
dl / g or more, particularly 0.70 to 0.90 dl / g, and a diethylene glycol unit content of 1.60% by weight or less, particularly 1.50% by weight or less is preferable. used.

[Production Method] The polyester bottle of the present invention is produced by a method in which a preform for a bottle body is stretch blow-molded in a blow mold. In this blow molding, heat setting is not generally performed, but light heat setting is allowed under the condition that the crystallinity is within the above range.

In the case of a polyester bottle with a vacuum absorbing handle, a handle is previously manufactured by injection molding, this handle is inserted into a blow mold, and a preform for the bottle body is stretch blow-molded in the blow mold. Method (insert blow molding method) or a preform for a bottle body is stretch blow-molded in a blow mold in advance to produce a bottle body 1, and the bottle body 1 is inserted into an injection mold; It is manufactured by a method of injection molding a handle resin (insert injection molding method). The former method is preferred.

The bottomed preform used for stretch blow molding can be prepared by any method known per se, for example, injection molding,
It is manufactured by a pipe extrusion method or the like. In the former method, molten polyester is injected, and a preform with a bottom and a neck corresponding to the final container is manufactured in an amorphous state. In the latter method, an extruded amorphous pipe is cut, a mouth and a neck are formed at one end by compression molding, and the other end is closed to form a bottomed preform. In general, it is preferable to manufacture by an injection molding method. Injection conditions and the like are not particularly limited, but generally, a bottomed preform can be molded at an injection temperature of 260 to 300 ° C. and an injection pressure of 30 to 60 kg / cm ² .

In order to impart heat resistance and rigidity to the mouth and neck of the preform thus obtained, the mouth and neck having a screw portion, a fitting portion, a support ring, etc. are crystallized by heat treatment and whitened at the stage of the preform. In some cases, on the other hand, after the completion of the biaxial stretching blow described later, after the bottle molding is completed, the mouth and neck portion of the unstretched portion may be crystallized and whitened.

The preform to be stretch blow-molded is preheated to the stretching temperature, generally between 100 and 130 ° C., and then biaxially stretched. A preform of the thermoplastic polyester preheated to the above temperature is mounted in the hollow mold, and the preform is expanded and stretched in the circumferential direction and stretched and stretched in the axial direction.

The stretching ratio in the final container is related to the crystallinity of the side wall of the bottle.
Is suitable, especially 7 to 12 times, while the linear draw ratio in the axial direction is 2 to 3.5 times, especially 2.5 to 3 times, and the draw ratio in the circumferential direction is 2 to 5 times, especially 3 to 4 times. It is better to double.

The temperature of the blow mold used for stretch blow molding is also related to the crystallinity of the side wall. Mold temperature is generally 6
It is preferably in the range of 0 to 100 ° C. Normal compressed air is used as the pressurized fluid for blowing.

As the handle, any thermoplastic resin that can be injection-molded can be used. As such a resin, polyethylene terephthalate (PE
T), thermoplastic polyesters such as polybutylene terephthalate; polycarbonates; acryl-butadiene-
Styrene copolymer (ABS resin); polyacetal resin; nylons such as nylon 6, nylon 66, and their copolymerized nylons; acrylic resins such as polymethyl methacrylate; isotactic polypropylene; Examples thereof include medium- or high-density polyethylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, and styrene-butadiene thermoplastic elastomer. Handle molding resin includes
Naturally, various coloring agents, fillers, and the like can be blended.

[0064]

The present invention is further described by the following examples.

Example 1. Intrinsic viscosity (IV) was 0.85 dl /
g, glass transition temperature (Tg) 68 ° C. (density d 1.335 g /
cm ³ ) and polyethylene terephthalate / isophthalate containing 3 mol% of isophthalic acid as a dibasic acid were injection molded to form a bottomed parison (preform) having a basis weight of 85 g.

Using this preform and the handle made of colored polypropylene produced by injection molding, a bottle with a handle having a reference internal volume of 1.8 liters having the shape shown in FIGS. 1 to 8 was produced. That is, the preform is heated to a stretching temperature of 120 ° C., and the preform is held in a blow mold in which a handle is inserted and the cavity surface temperature is heated to 80 ° C., and is stretched in an axial direction with a stretching rod. And by expanding and stretching by blowing compressed air,
The bottle was formed by biaxial stretching blow. The dimensions of each part are as follows.

36 mm in diameter, 321.5 mm in total height, 109 mm in maximum torso, 82 mm in handle (hand insertion part), 22 mm in radial dimension, 22 mm in upper torso, 3 reduced pressure absorption surfaces 27 in upper half, 40 mm in upper edge. 8mm Bottom edge width 52.8mm Height 88.6mm, Upper trunk connecting part 282mm, Label surface (sticking surface) Height 112.3mm, Width 102.4mm, Lower trunk decompression absorption surface 29 Arrangement Three in half circumference , Height 101.5mm, width 52.8mm, lower trunk connecting part 302mm,

For the above bottle, the crystallinity of the side wall was measured by a density method. The results were as shown in Table 1 below.

[0069]

[Table 1]

The above bottle was filled with 1.8 liters of sake and cooled to 5 ° C. and 15 ° C. after filling. The volume loss after cooling was 58 ml at 5 ° C and 49 ml at 15 ° C.
Almost no swelling of the bottle during filling was observed.

As a result of observing the bottle after cooling, the reduced pressure was completely absorbed by the reduced pressure absorbing surfaces of the upper and lower body portions of the bottle, and no irregular deformation was recognized at the concave portion for attaching the handle and the label surface. . In the case of cooling at 5 ° C., when the cooling pressure is 5 ° C., the depressurized absorbing surface of the lower trunk portion retreats inward by 5.6 mm in diameter.
It was inverted to a concave shape. Among the above-mentioned volume reductions, about 66% at 5 ° C. was caused by deformation of the reduced-pressure absorbing surface, and the remainder was caused by shrinkage of the container.

Example 2 Intrinsic viscosity (IV) was 0.85 dl /
g, glass transition temperature (Tg) 68 ° C (density d 1.335 g / cm
³ ) and polyethylene terephthalate / isophthalate containing 3 mol% of isophthalic acid as a dibasic acid was injection molded to form a bottomed parison (preform) having a basis weight of 110 g.

Using the preform and the handle made of colored polypropylene manufactured by injection molding, a bottle with a handle having a reference internal volume of 2.7 liters having a shape shown in FIGS. 1 to 8 was manufactured.

This preform is heated to a stretching temperature of 120 ° C., and the preform is held in a blow mold in which a handle is inserted and the cavity surface temperature is heated to 80 ° C., and is pulled in an axial direction by a stretching rod. By stretching, by blowing compressed air, by expanding and stretching,
The bottle was formed by biaxial stretching blow. The dimensions of each part are as follows.

Diameter 36 mm, overall height 356 mm, maximum body diameter 128 mm, handle (dimensions in the hand insertion portion) height 87.5 mm, radial dimension 22.0 mm, upper body decompression absorption surface 27 arrangement Three on half circumference, upper edge Width 42.0mm Lower edge width 60.1mm Height 89.3mm, Upper trunk connecting part 283mm, Label surface (sticking surface) Height 124.9mm, Width 122.7mm, Lower trunk decompression absorption surface 29 Arranged half circumference Three, upper edge width 60.1mm lower edge width 61.6mm height 98mm, lower trunk connecting part 303mm,

The crystallinity of the side wall of the above bottle was measured by a density method. The results were as shown in Table 2 below.

[0077]

[Table 2]

The above bottle was filled with 2.7 liters of sake having a product temperature of 70 ° C., and cooled to 5 ° C. and 15 ° C. after filling. 88 ml at 5 ° C, 74 ml at 15 ° C after cooling
Met. Almost no swelling of the bottle during filling was observed. Of the above volume reduction,

As a result of observing the bottle after cooling, the reduced pressure was completely absorbed by the reduced pressure absorbing surfaces of the upper body and the lower body of the bottle, and no irregular deformation was recognized at the concave portion for attaching the handle and the label surface. . In the case of cooling at 5 ° C., the depressurization absorbing surface of the lower body portion has a convex shape receding inward by 6.2 mm in diameter,
It was inverted to a concave shape. Among the above-mentioned volume reductions, about 66% at 5 ° C. was caused by deformation of the reduced-pressure absorbing surface, and the remainder was caused by shrinkage of the container.

[0080]

According to the present invention, in a bottle formed by stretch blow molding of a thermoplastic polyester and provided with a plurality of reduced pressure absorbing surfaces in a side wall in a convex shape, ethylene terephthalate is used as the thermoplastic polyester. By using a copolymerized polyester as a main component and maintaining the crystallinity of the side wall portion in the range of 15 to 30%, irregularity or asymmetricity after hot filling (hot pack) of the content is achieved. Deformation under reduced pressure was effectively prevented irrespective of the asymmetric structure of the reduced pressure absorbing surface of the body.

Even in a bottle provided with a handle attaching portion and a label surface on the body side wall, the decompression deformation after hot filling (hot pack) of the contents may cause the asymmetric structure of the container body. Regardless, it was effectively absorbed at a fixed part of the container wall, and irregular deformation at the handle attachment part and the label part and cracks on the container wall at the boundary part were effectively prevented.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of a polyester bottle with a handle of the present invention.

FIG. 2 is a side view showing the bottle of FIG. 1 rotated by 90 °.

FIG. 3 is a rear view of the bottle of FIG. 1;

FIG. 4 is a top view of the bottle of FIG. 1;

FIG. 5 is a bottom view of the bottle of FIG. 1;

FIG. 6 is a sectional view taken along line AA in FIG. 2;

FIG. 7 is a schematic sectional view taken along the line BB in FIG. 2, showing an unfilled state.

FIG. 8 is a schematic cross-sectional view taken along the line BB in FIG. 2, showing a state where the pressure is reduced after hot filling and sealing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bottle main body 2 Handle 3 Neck 4 Cylindrical trunk part 5 Closed bottom part 6 Frustum-shaped shoulder part 7 Upper trunk part 8 Lower trunk part 9 Handle attachment part 10 Label surface 11 Upper surface of handle attachment recess 12 Side surface 13 Lower surface 14 Handle attachment Projecting portion 15 Small cylindrical portion 16 Flange portion 17 Tip surface 18 Peripheral groove 20 Endless gripping portion 21 Mounting portion 22 Vertical portion of gripping portion 23 Upper curvature portion 24 Lower curvature portion 25 and 26 Locking stabilization Projection 27 and 27a Decompression absorption surface of upper torso 28 Connection part of upper torso 29 Decompression absorption surface of lower torso 30 Connection part of lower torso 31 Boundary part 32 Bending part for protection of lower torso 33 Reinforcing Step 34 Reinforcement bead 35 Screw for opening and closing the cap 36 Step for fastening 37 Support ring 38 Engagement recess for positioning

Claims (3)

(57) [Claims] 1. A bottle formed by stretch blow molding of a thermoplastic polyester and having a plurality of reduced pressure absorbing surfaces formed on a side wall in a convex shape, wherein the thermoplastic polyester is a copolymer containing ethylene terephthalate as a main component. A bottle made of reduced-pressure-absorbent polyester, which is made of polyester and has a side wall crystallinity in the range of 15 to 30%. 2. The bottle according to claim 1, wherein the polyester is an ethylene terephthalate copolymerized polyester containing 1 to 3% of an isophthalic acid unit as an acid component. 3. A bottle with a handle provided with a bottle body formed by stretch blow molding of a thermoplastic polyester and a handle made of a thermoplastic resin separate from the bottle body.
The bottle body includes a handle mounting portion and a label surface on the body portion, and has a plurality of reduced-pressure absorbing surfaces in a convex shape on the body portion other than the handle mounting portion and the label surface via a connecting portion, and A vacuum-absorbent handle-equipped polyester bottle, wherein the plastic polyester is a copolymerized polyester containing ethylene terephthalate as a main component, and the crystallinity of the body side wall is in the range of 15 to 30%.