JPH0651342B2 - Heat and pressure resistant polyester bottle and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pressure-resistant container to which internal pressure is applied, such as a gas-containing beverage such as a carbonated beverage, which has excellent sealing property, large wrapping resistance, and , A heat- and pressure-resistant polyester bottle that does not deform due to heat or pressure during the production of containers, filling of high-temperature liquid, or heat sterilization of contents,
And a manufacturing method thereof.

[Prior Art] Conventionally, as a pressure-resistant container to which an internal pressure is applied, such as a carbonated beverage, a container including a hollow container body and a base cup attached to the bottom surface of the container body has been used.

Usually, the container body is composed of a mouth-neck part having a support ring, a body part, and a bottom part, and since the internal pressure is applied, the bottom part is rounded in the shape of a spherical shell to enhance the pressure resistance, and the base cup of the container Standing is possible.

Such a container body is usually prepared by preforming a preform made of a polyethylene terephthalate resin and subjecting the preform to biaxial stretching blow molding,
After causing the resin material to undergo oriented crystallization to impart heat resistance and pressure resistance to the body and bottom of the container body, heat and crystallize it by heating the mouth and neck to impart heat resistance and pressure resistance. It is built.

However, in such a one-stage method, since the mouth and neck of the preform is not heated and crystallized in advance,
The mouth and neck are also heated and stretched during blow molding, and after molding, the neck height, which is the height from the lower edge of the support ring located below the mouth and neck to the upper end of the mouth and neck, varies significantly. The value became large, and the standard deviation was usually around 1 mm, and there were many defects that the screw cap did not close completely even when the screw cap was wound, and the contents could leak.

Therefore, the standard deviation of neck height variation is 0.5 mm.
There was a strong demand to hold down below.

An even bigger problem is that the lower part of the support ring is poorly heat-resistant because it is not crystallized, and there are some parts that are crystallized, which causes distortion, and the neck part after blow molding The phenomenon that the mouth and neck part tilts during thermal crystallization, that is, the neck bending phenomenon occurs.

Also, when filling contents into the container body,
A method of hot filling and sealing the contents heated to 80 to 95 ° C, or a method of filling a gas such as nitrogen, or filling the contents in the container body and then capping and sealing the mouth and neck, and then the container body There is a method to heat and sterilize the contents by pouring hot water from above, but the neck bending phenomenon is also caused when filling such hot contents and when sterilizing the contents with hot water from the top of the container. Occur.

If this neck bending occurs, not only will the appearance of the container be impaired, but there is the danger that the winding will be insufficient and the contents will leak as described above.

Further, it is also possible to heat the mouth and neck portion of the preform in advance to thermally crystallize it, and then blow-mold to heat and stretch the portion other than the mouth and neck portion to mold the container, but the obtained container is , The mouth and neck are uniform, the crystal orientation is not oriented, and the crystallinity is thermally crystallized to a high crystallinity of 30 to 45%. Therefore, there is a drawback that the altitude is high but brittle. The support ring may break when the cap is tightened.
There was a problem of breaking the mouth and neck when dropped.

This point is the same as in the case where the mouth-neck portion is thermally crystallized after the blow molding described above.

Further, if the mouth-neck portion is uniformly crystallized with high heat, there is a drawback that the whitened portion becomes large and the whitened portion protrudes when the cap is covered, and the appearance of the container is extremely deteriorated.

As an example of such a conventional technique, for example, in Japanese Unexamined Patent Publication No. 61-35056, the container mouth portion and the annular support projecting edge portion are whitened and crystallized, and the lower body portion from the projecting edge portion is molded. A post heat set container is described. It is clarified that the boundary is to join the clearly separated white high thermal crystallization region and the oriented crystal region, and it is a special invention that places a portion with a significant difference in thermal crystallization degree on the boundary surface. Is clear.

The invention described in Japanese Patent Laid-Open No. 58-36420 discloses that "the outer peripheral surface of the neck-equivalent portion immediately below the mouth-cylinder-corresponding portion is tapered downward, and the entire mouth-cylinder-corresponding portion and the body-corresponding portion are removed. This is a method of manufacturing a bottle by using a "preform" in which the outer periphery of the portion corresponding to the neck is thermally crystallized.

The invention described in Japanese Patent Laid-Open No. 59-84731 relates to a bottle in which the entire upper part of the mouth is thermally crystallized and the part from the inner surface of the lower part of the mouth to the neck is non-crystallized. That is, the entire upper portion of the mouth portion and the portion from the lower outer surface of the mouth portion to the neck portion are thermally crystallized, and the portion from the lower inner surface of the mouth portion to the neck portion is non-crystallized.

And, as the explanation, it is described that the crazing on the inner surface of the mouth is prevented by the structure in which the crystallized portion and the non-crystallized portion are formed in the portion extending from the mouth portion to the neck portion of the bottle. As described above, these prior arts cannot solve the extreme discontinuity in the thermal crystallization degree at the boundary surface between the thermal crystallization region and the oriented crystallization region, and cannot eliminate the stress strain at the interface.

A feature of the present invention is to attach a high-stretch crystallization region extending from the body to provide a thermal crystallization region having a gradually decreasing thermal crystallization degree to a position below the rising part of the mouth and neck, that is, the support ring, Is not disclosed at all. This structure is a novel structure first invented by the present inventor.

In addition, the present invention has a unique and excellent function and effect which will be described later with this configuration.

[PROBLEMS TO BE SOLVED BY THE INVENTION] It is an object of the present invention to provide a heat and pressure resistant polyester bottle which has excellent sealing property, large resistance to winding, is not deformed by high heat or high pressure, and has an excellent appearance.

[Means and Actions for Solving the Problem] That is, the present invention provides “(1) a trunk, a bottom, and a mouth and neck, and
Thermal crystallinity is high at the upper end of the mouth and neck, and small thermal crystal regions are sequentially provided toward the rising part of the mouth and neck, and oriented crystallization from the upper end of the mouth and neck to the rising part of the mouth and neck. A heat and pressure resistant polyester bottle with a degree of zero. (2) The thermal crystallinity of the thermal crystal region is 30 to 45% from the upper end of the mouth and neck to the upper edge of the support ring, and from the upper edge of the support ring to the rising portion of the mouth and neck. Is 1 to 6.5%
The heat and pressure resistant polyester bottle according to claim 1, wherein the oriented crystallinity between the upper end of the mouth and neck and the rising portion of the mouth and neck is substantially zero. (3) body, bottom,
The upper neck of the mouth and neck has a higher degree of thermal crystallinity, and smaller thermal crystal regions are provided toward the rising part of the mouth and neck in the mouth and neck. A method for producing a heat- and pressure-resistant polyester bottle, which comprises stretch-blow-molding a preform in which the degree of oriented crystallinity up to the rising portion of the neck is almost zero.

(4) The thermal crystallinity of the thermal crystal region of the preform is 30 to 45 between the upper end of the mouth and neck and the upper edge of the support ring.
%, The range from the upper edge of the support ring to the rising part of the mouth and neck is 1 to 6.5%, and the orientation crystallinity from the upper end of the mouth and neck to the rising part of the mouth and neck is The method for producing a heat and pressure resistant polyester bottle according to claim 3, wherein the method is substantially zero.

(5) The body, the bottom, and the preform consisting of the mouth and neck, after stretch blow molding to form a bottle, the mouth and neck of the bottle is thermally crystallized, the thermal crystallinity is the mouth and neck. The upper part of the upper part is high, and small thermal crystal regions are sequentially provided toward the rising part of the mouth and neck, and the oriented crystallinity between the upper part of the mouth and neck and the rising part of the mouth and neck is set to almost zero. A method for producing a heat and pressure resistant polyester bottle, which is characterized.

(6) The thermal crystallinity of the thermal crystal region is 30 to 45% from the upper end of the mouth and neck to the upper edge of the support ring, and from the upper edge of the support ring to the rising portion of the mouth and neck. Is 1
The method for producing a heat and pressure resistant polyester bottle according to claim 5, wherein the oriented crystallinity between the upper end of the mouth and neck and the rising portion of the mouth and neck is substantially zero. It is.

The present invention, the mouth neck of the polyester bottle consisting of the body, the bottom, and the mouth and neck, the thermal crystallinity is high at the upper end of the mouth and neck, and the heat gradually decreases toward the mouth and neck rising portion. A crystal region is provided so that the oriented crystallinity between the upper end of the mouth and neck and the rising portion of the mouth and neck is substantially zero.

Conventionally, the thermal crystallinity of the thermal crystal region, which is arranged between the mouth and neck and the rising portion of the neck and neck to which the mouth and neck are connected, does not change sequentially but changes extremely. Was discontinuous, and therefore, the strain on the boundary surface with the stretched crystal region was extremely large, and there was a defect that the portion was broken when dropped.

The present invention, the boundary surface of the rising portion of the mouth and neck, by attaching a thermal crystal region of low thermal crystallinity, and a highly stretched crystal region, the neck and neck portion is a rising portion in the rising portion crystallinity degree Since it is connected to the high-stretch crystal region while gradually changing, the stress strain at the boundary surface is extremely small, and the flexibility of the low-heat crystal region absorbs the impact, so It does not break from any point.

The thermal crystallinity of the thermocrystal region of the mouth and neck is 30 to 45% between the upper end of the mouth and neck and the upper edge of the support ring.
And, if the distance from the upper edge of the support ring to the rising portion of the neck and neck is 1 to 6.5%, and the orientation crystallinity between the upper end of the mouth and neck and the rising portion of the mouth and neck is almost zero, As described above, the continuous connection of the crystallinity of the boundary surface of the rising part of the mouth and neck becomes extremely good, and the thermal crystallinity of the part is set to 1 to 6.5%, so that the bottle is Neck height, which is the height from the upper end of the mouth and neck to the lower edge of the support ring, does not cause neck bending when filling hot contents or when sterilizing with hot water. Therefore, the variation becomes extremely small.

The thermal crystallinity of the thermocrystal region of the mouth and neck is set to 30 to 45% between the upper end of the mouth and neck and the upper edge of the support ring to suppress the change in the sealing property with time after capping, that is, , Keep the tightening torque after capping constant,
This is because it guarantees the sealing property and the easy-opening property, and there is no neck bending and variation in neck height is eliminated. 1 to between the upper edge of the support ring and the rising part of the mouth and neck
The reason for setting 6.5% is that the support ring is cracked by the lift pressure during capping. By lowering the crystallinity of this, it becomes more flexible than that of high crystallized one, and the crack of the support ring is prevented.

Moreover, since the thermal crystallization degree is low, the whitening phenomenon does not occur and the commercial value is improved.

Further, a body, a bottom, and a polyester bottle consisting of a mouth and neck, in the mouth and neck, the thermal crystallinity is high at the upper end of the mouth and neck, and the thermal crystals are gradually smaller toward the mouth and neck rising portion. A region is provided, and the oriented crystallinity between the upper end of the mouth and neck and the lower edge of the support ring is substantially zero, and an oriented crystal region is provided between the lower edge of the support ring and the rising portion of the mouth and neck, The rising part of the neck and neck, which is the most vulnerable to the drop impact, becomes the same stretched crystal region as the body part, and the drop impact resistance becomes extremely large. Then, the connecting portion between the stretched crystal region and the low heat crystal region moves to the support ring portion, and the strain on the boundary surface becomes further smaller.

Moreover, by increasing the thermal crystallinity of the upper end of the mouth and neck and decreasing it toward the rising portion of the mouth and neck, the neck height variation becomes extremely small.

In order to produce the heat and pressure resistant polyester bottle of the present invention, the mouth neck portion has a high thermal crystallinity at the mouth neck upper end in advance, and the mouth neck rises after molding from the mouth neck upper end. The thermal crystal region is gradually reduced toward the part, and the body, the bottom and the neck of the bottle have almost zero oriented crystallinity between the top of the mouth and neck and the part that becomes the rising part of the mouth and neck of the bottle. A preform composed of a part and a stretch blow molding may be formed.

At this time, the thermal crystallinity of the thermal crystal region of the mouth and neck of the preform is set to 30 to 45% between the upper end of the mouth and neck and the upper edge of the support ring, and the upper edge of the support ring is connected to the bottle mouth. 1 to 6.5 up to the neck rising part
%, A heat and pressure resistant polyester bottle showing a good state can be obtained.

That is, the thermal crystallinity of the thermal crystal region of the preform,
30 between the upper edge of the mouth and neck and the upper edge of the support ring
45%, and the distance from the upper edge of the support ring to the lower edge of the support ring is 1 to 6.5%. When stretch blow molding is performed using this preform, the lower edge of the support ring of the bottle to the neck of the mouth A heat-resistant polyester bottle having a oriented crystallinity up to the rising portion of 30 to 45% and a highly stretched and crystallized other region in a good condition can be obtained.

Further, the heat and pressure resistant polyester bottle of the present invention, after forming a bottle by stretch blow molding a preform consisting of a body portion, a bottom portion and a mouth and neck portion, heat crystallization of the mouth and neck portion,
The thermal crystallinity is set so that the thermal crystallinity is higher at the upper end of the mouth and neck and is gradually reduced from the upper end of the mouth and neck toward the rising part of the neck, and the thermal crystallinity between the upper end of the neck and the rising part of the neck It can be obtained by setting the oriented crystallinity to almost zero.

Further, the heat and pressure resistant polyester bottle of the present invention, after forming a bottle by stretch blow molding a preform consisting of a body portion, a bottom portion and a mouth neck portion, heat crystallization of the mouth neck portion of the bottle, and the thermal crystallization The thermal crystallinity of the region is 30 to 45% between the upper end of the mouth and neck and the upper edge of the support ring,
By setting the distance from the upper edge of the support ring to the rising portion of the neck and neck to 1 to 6.5% and setting the oriented crystallinity between the upper end of the mouth and neck and the rising portion of the mouth and neck to almost zero. A heat and pressure resistant polyester bottle exhibiting the above-mentioned good condition can be obtained.

Further, in a preform composed of a body, a bottom and a mouth / neck, the wall thickness between the support ring of the mouth / neck and a part formed by the rising part of the mouth / neck when molded into a bottle is measured as the body thickness. A preform that is thinner than the wall thickness of the part is made, and using this preform, the thin wall part is heated to a temperature lower than the body part and stretch blow molded to improve the oriented crystallinity of this part. After forming a bottle body with 30 to 45%, heat crystallize from the upper end of the mouth and neck to the support ring to increase the thermal crystallinity at the upper end of the mouth and neck and from the upper end of the neck and neck. The heat and pressure resistant polyester bottle of the present invention can be obtained also by providing the thermal crystal regions which are successively reduced toward the rising portion.

(Example) Next, an Example is concretely described about drawing.

FIG. 1 shows an embodiment of the present invention, in which 1 shows the whole container,
Reference numeral 2 denotes a container body, and 3 denotes a base cup. Also,
4 indicates the mouth and neck, 5 indicates the trunk, 6 indicates the bottom,
Reference numeral 7 indicates a support ring provided on the mouth and neck, and 11 indicates a rising portion of the mouth and neck.

FIG. 2 is a mouth / neck portion 4 of the container body 2 of this embodiment shown in FIG.
FIG. Further, 8 indicates a neck height, 9 indicates a lower portion of the support ring, and 17 indicates a tightening ring.

The container body 2 of this embodiment has a height of 320 mm, the body portion 5 has an inner diameter of 100 mm and an outer diameter of 102 mm, and the mouth / neck portion 4 is high, that is, the upper end portion of the mouth / neck portion. To the rising part 11 of the mouth and neck is 34 mm, and the inner diameter is 20 mm,
A polyester bottle main body having an outer diameter of 26 mm, a support ring 7 is provided in the mouth / neck portion 4 at a position 20 mm lower than the upper end portion of the mouth / neck portion, and as shown in FIG.
The thermal crystallinity of the section (a) from the upper end of the mouth and neck to the upper edge of the support ring 7 is 40%, and the section from the upper edge of the support ring to the rising portion 11 of the mouth and neck (b) Has a thermal crystallinity of 5%, the orientation crystallinity in the section from the upper end of the mouth and neck to the rising portion 11 of the mouth and neck is almost zero, and the other portions are highly stretched and crystallized. .

The container 1 in which the base cup 3 is attached to the container body 2 is the heat and pressure resistant polyester bottle of the present invention shown in FIG.

This bottle has variations in neck height per bottle.
Neck height lot (160 mm) with standard deviation of 0.25 mm
The standard deviation is 0.11 mm.
It is extremely small compared to 0.5mm and 0.24mm, and the strength of the support ring is high, so there is no damage to the support ring when tightening the cap, and the sealing performance is extremely improved. Moreover, the whiteness of the lower part of the support ring is not seen, and the bottle has excellent commercial value.

FIG. 3 shows a preform used for manufacturing the container of the present invention.

4 indicates the mouth-neck portion, 7 indicates the support ring, 8 indicates the neck height, 9 indicates the lower portion of the support ring, 10 indicates the portion which becomes the rising portion of the mouth-neck portion of the container after stretch blow molding, Further, 15 is a body of the preform, 16 is a bottom, and 17 is a winding ring.

Example 1 As shown in FIG. 3, the inner diameter is 20 mm, the outer diameter is 26 mm, and the height is 130 mm.
It is a preform with a 3mm wall-thick polyester cylinder with a bottom, and a mouth and neck with a support ring attached 20mm below the top and neck of the mouth and upper edge of the support ring from the top and neck of the mouth. 40% thermal crystallinity up to section
The thermal crystallinity of the section from the lower edge of the support ring to the portion 10 which is the rising portion of the mouth and neck of the bottle up to 10 is 5%, and from the upper end of the mouth and neck to the mouth and neck of the bottle. The preform with oriented crystallinity in the section up to the rising part 10 of which is almost zero is stretch blow-molded, and the height is 320 mm, the inner diameter of the body is 100 mm, the outer diameter is 102 mm, and the height of the mouth and neck. 3
A polyester bottle body with a diameter of 4 mm, an inside diameter of 20 mm, and an outside diameter of 26 mm was manufactured, and a base cup was attached to the body to obtain a heat and pressure resistant polyester bottle.

In this bottle, the variation per neck height 8 is 0.25 mm as the standard deviation, and the variation between the neck height 8 lots (160 bottles) is 0.11 mm as the standard deviation,
Compared to the conventional 0.5 mm and 0.24 mm, it is extremely small, the strength of the support ring is high, the support ring is not damaged when the cap is tightened, and the sealing performance is greatly improved. Moreover, the whiteness of the lower part of the support ring is not seen, and the bottle has excellent commercial value.

Example 2 Wall thickness 3 mm with bottom of inner diameter 20 mm, outer diameter 26 mm, height 130 mm
Stretch blow molding a preform with a polyester ring of 20 mm down from the upper end of the neck and neck and a neck and neck with a support ring, height 320 mm, inner diameter 100 mm, outer diameter 102 mm , The height of the mouth and neck is 34 mm, the inner diameter is 20 mm, and the outer diameter is 26 mm, and a polyester bottle body is manufactured. As shown in FIG. 2, the section from the upper end of the mouth and neck to the upper edge of the support ring 7 (a ) Is 40%, the thermal crystallinity of the section (b) from the upper edge of the support ring to the rising part 11 of the neck and neck is 5%, the top and neck of the mouth and neck are Thermal crystallization so that the orientation crystallinity in the section up to the rising portion 11 becomes almost zero, and the other portion is highly stretched and crystallized, and the base cup is attached to the obtained container body to obtain the heat and pressure resistance of the present invention. I got a polyester bottle.

[Brief description of drawings]

FIG. 1 is a partial sectional front view of a heat and pressure resistant polyester bottle of the present invention. FIG. 2 is an enlarged partial cross-sectional view of the mouth and neck of the heat and pressure resistant polyester bottle of the present invention shown in FIG. FIG. 3 is a partial cross-sectional front view of a preform used in the production of the heat and pressure resistant polyester bottle of the present invention. 1 ... Heat and pressure resistant polyester bottle (container), 2 ... Container body, 3 ... Base cup, 4 ... Preform or container neck, 5 ... Container body, 6 ... Container Bottom of the main unit, 7 ... Support ring, 8 ... Neck height, 9 ... Lower part of support ring, 10 ... Preform part that is the rising part of the neck of the container body, 11 ... Mouth neck of the container body Rise part, 12 …… preform, 15 …… preform body, 16 …… preform bottom, 17 …… winding ring a …… high heat crystallization region of mouth neck, b …… mouth Low heat crystallization region of the neck,

Claims (6)

[Claims] 1. A body, a bottom, and a mouth / neck, wherein the mouth / neck has a higher degree of thermal crystallinity at the upper end of the mouth / neck, and the heat gradually decreases toward the rising portion of the mouth / neck. A heat- and pressure-resistant polyester bottle in which a crystalline region is provided, and the degree of oriented crystallinity between the upper end of the mouth and neck and the rising portion of the mouth and neck is substantially zero. 2. The thermal crystallinity of the thermal crystal region is 30 to 45% from the upper end of the mouth and neck to the upper edge of the support ring, and from the upper edge of the support ring to the rising portion of the mouth and neck. Is 1 to 6.5%, and the oriented crystallinity between the upper end of the mouth and neck and the rising portion of the mouth and neck is almost zero, and the heat and pressure resistant polyester bottle according to claim 1. . 3. A body, a bottom, and a mouth / neck portion, wherein the mouth / neck portion has a higher degree of thermal crystallinity at the upper end portion of the mouth / neck portion, and the heat gradually decreases toward the rising portion of the mouth / neck portion. A crystalline region is provided, and the orientation crystallinity between the upper end of the mouth and neck and the rising portion of the mouth and neck is set to almost zero, and the preform is stretch-blow-molded, which is characterized by a heat and pressure resistant polyester bottle. Production method. 4. The thermal crystallinity of the thermal crystal region of the preform is 30 to 45% from the upper end of the mouth and neck to the upper edge of the support ring, and the thermal crystallinity from the upper edge of the support ring to the mouth and neck is increased. The heat-resistant pressure resistance according to claim 3, wherein the distance up to the rising portion is 1 to 6.5%, and the orientation crystallinity between the upper end portion of the mouth and neck portion and the rising portion of the mouth and neck portion is substantially zero. For producing a flexible polyester bottle. 5. A bottle preform comprising a body portion, a bottom portion and a mouth neck portion is stretch blow-molded to form a bottle, and the mouth neck portion of the bottle is thermally crystallized to have a thermal crystallinity of the mouth. The upper end of the neck is high, and small thermal crystal regions are provided toward the rising part of the mouth and neck, and the orientation crystallinity between the upper end of the mouth and neck and the rising part of the mouth and neck is almost zero. A method for producing a heat and pressure resistant polyester bottle, comprising: 6. The thermal crystallinity of the thermal crystal region is 30 to 45% from the upper end of the mouth and neck to the upper edge of the support ring, and from the upper edge of the support ring to the rising portion of the mouth and neck. Is 1 to 6.5%, and the oriented crystallinity between the upper end of the mouth and neck and the rising portion of the mouth and neck is substantially zero. Manufacturing method.