JPH0615725A - Heat resistant biaxially stretch blow molded bottle and method for producing the same - Google Patents

Abstract

(57) [Abstract] [Purpose] The mouth has excellent heat resistance and impact resistance, and when heat crystallization treatment is applied to the mouth to impart heat resistance Provided is a heat-resistant biaxially stretch blow-molded bottle that does not deform. [Structure] A polyester resin and a heat-resistant resin are co-injected to produce a parison having a multilayer structure at the mouth, and the mouth of the parison is subjected to heat treatment, or the parison is biaxially stretch blow-molded. After that, a bottle obtained by subjecting the mouth of the obtained bottle to a heat treatment,
The mouth portion has a multilayer structure including a crystalline polyester layer and a non-crystalline heat resistant resin layer.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant bottle produced by biaxial stretch blow molding and a method for producing the same, and in particular, it has a mouth portion excellent in heat resistance and impact resistance, and is heat-treated in the mouth portion. The present invention relates to a heat-resistant biaxially stretch blow-molded bottle in which the deformation of the mouth portion when applied is prevented, and a method for producing the bottle.

[0002]

2. Description of the Related Art In recent years,
So-called hot fill, which fills a polyester bottle with a liquid at 80 to 95 ° C, and pasteurizing with a hot shower for bottles filled with carbonic acid-containing fruit juice, lactic acid bacteria beverages, etc., will be performed especially near the mouth. Excellent heat resistance is now required. For hot fill, the mouth is first exposed to a hot liquid, and also for pasteurizing with a hot shower,
This is because it is common to pour the hot shower from above the bottle.

However, in a polyester bottle obtained by ordinary biaxially stretch blow molding, the mouth portion is left unstretched, so that heat resistance cannot be imparted by stretching, and it is necessary to fill a liquid at 80 to 95 ° C. Can not serve.

Under these circumstances, various attempts have been made to impart heat resistance to polyester bottles.

[0005] As such an attempt, a method of crystallizing the polyester to improve the heat resistance by subjecting the bottle to a heat treatment at the mouth portion at the stage of parison or after biaxial stretch blow molding is carried out. ing. However, this method has a problem that the dimension of the mouth portion is likely to change due to the crystallization of the polyester when the parison is heat-treated, and in particular, contraction is likely to occur at the mouth end. Therefore, a jig for shrinkage prevention is inserted on the inner diameter side of the mouth of the parison to perform thermal crystallization.
If the polyester can be crystallized without deforming the mouth portion without inserting a jig, it is advantageous because the production of the heat resistant bottle can be simplified.

Further, since the mouth of the bottle obtained by the above method is composed of a single layer of crystalline polyester resin, there is a problem that the impact resistance of the mouth is not always sufficient.

On the other hand, various methods of making a parison having a multi-layer structure composed of a heat resistant resin and a polyester resin so that a large amount of the heat resistant resin is arranged in the mouth have been tried. However, even with the above method, it is difficult to obtain heat resistance that can be continuously used when performing pasteurizing with a hot shower at 65 to 80 ° C. for a long time or under severe hot fill conditions of 90 ° C. or higher.

Therefore, an object of the present invention is to have a mouth portion having excellent heat resistance and impact resistance, and to use heat crystallization treatment on the mouth portion for imparting heat resistance without using a jig or the like. It is also an object of the present invention to provide a heat-resistant biaxially stretch blow-molded bottle that does not deform its mouth and a method for producing the bottle.

[0009]

As a result of earnest research in view of the above object, the present inventor co-injected a polyester resin and a heat-resistant resin to produce a parison having a multi-layered structure at the mouth portion. After heat-treating the mouth of the bottle, or after biaxially stretch blow molding this parison, heat-treat the mouth of the obtained bottle, and insert a shrinkage prevention jig into the inner diameter of the mouth. It has been found that the mouth of the bottle does not substantially deform even if it does not exist. Further, in the biaxially stretched blow-molded bottles thus obtained, the polyester resin layer at the mouth is crystallized, and the heat-resistant resin layer is present as an amorphous layer. It was found that they have sufficient heat resistance against a shower and also have excellent impact resistance. The present invention has been made based on the above findings.

That is, the heat-resistant biaxially stretch blow-molded bottle of the present invention has a mouth portion, a support ring provided at the lower end of the mouth portion, a shoulder portion following the support ring, a body portion, and a bottom portion. The heat-resistant biaxially stretched blow-molded bottle having a multilayer structure having a crystalline polyester layer and an amorphous heat-resistant resin layer, wherein the crystalline polyester layer has an amorphous polyester layer. It is characterized by being crystallized by heating.

The first method of the present invention for producing the heat-resistant biaxially stretch blow-molded bottle is as follows: (a) a mouth having a multilayer structure consisting of an amorphous polyester layer and an amorphous heat-resistant resin layer. Forming a bottomed cylindrical parison having a portion, a support ring provided at the lower end of the mouth portion, a body portion following the support ring, and a bottom portion, and (b) applying heat treatment to the mouth portion. Thus, the amorphous polyester layer is crystallized, and (c) subsequently, the parison is biaxially stretch blow molded.

Further, the second method of the present invention for producing the heat-resistant biaxially stretch blow-molded bottle is as follows: (a) A mouth having a multilayer structure comprising an amorphous polyester layer and an amorphous heat-resistant resin layer. Part, a support ring provided at the lower end of the mouth part, a body part following the support ring, and a bottomed cylindrical parison having a bottom part are formed, and (b) the parison is biaxially stretch blow molded. Then, (c) the mouth portion of the obtained biaxially stretched blow-molded bottle is subjected to a heat treatment to crystallize the amorphous polyester layer at the mouth portion.

[0013]

The present invention will be described in detail below. As illustrated in FIG. 1, the heat-resistant biaxially stretch-blow molded bottle of the present invention has a mouth portion 1, a shoulder portion 2, a support ring 5 provided therebetween, a body portion 3, and a bottom portion 4. Consisting of and mouth 1
1 has a multi-layer structure in which a non-crystalline heat resistant resin layer 21 and a crystalline polyester layer 22 are alternately formed as shown in FIGS. Note that the shoulder portion, body portion, and bottom portion of the bottle are not limited to the shape shown in FIG. 1, and may be appropriately changed to various shapes found in conventional plastic bottles. The heat-resistant biaxially stretch blow-molded bottle of the present invention is characterized by the multilayer structure of its mouth. Also, in the case of a thick container that does not require a support ring, the support ring may be omitted, and the mouth seal is
It goes without saying that shapes other than screws can be selected as appropriate.

With the heat-resistant resin thus arranged,
By crystallizing the polyester layer of the mouth, 80 ~ 95
It is possible to obtain a bottle having good heat resistance capable of sufficiently withstanding hot filling for filling a liquid at a temperature of 70 ° C. or hot shower at a temperature of 70 to 80 ° C. for about 30 minutes from above the bottle. Further, the heat-resistant biaxially stretched blow-molded bottle of the present invention has a mouth portion composed of a crystalline layer and a non-crystalline layer, so that a heat-resistant biaxially stretched blow bottle having a mouth portion composed of a conventional crystalline layer single layer Superior impact resistance compared to molded bottles.

The bottle having a multi-layered structure in the mouth portion is basically manufactured by using a parison having a multi-layered structure in which the mouth portion has an amorphous polyester layer and an amorphous heat-resistant resin layer. be able to. Here, the non-crystalline polyester layer means an amorphous state,
It is generally obtained by melting and then quenching.

FIG. 3 shows an example of the mouth of a parison from which the heat resistant biaxially stretch blow molded bottle of the present invention can be manufactured. As illustrated in FIG. 3, the parison mouth portion 31 includes a thread portion 32 and a support ring portion 33. The mouth portion 31 having such a shape has a multilayer structure in which the amorphous heat-resistant resin layer 35 and the amorphous polyester layer 36 are alternately formed,
The heat-resistant resin layer 36 has three layers (35a to 35c) in order from the outside at least from the opening of the mouth 31 to the lower part thereof. The outermost heat-resistant resin layer 35a is the support ring 34
Is continuous to the upper surface of. On the other hand, the polyester layer 36 is present between the heat resistant resin layers, and has two layers 36a and 36b. The base of the lower surface of the support ring 34 is made of a polyester layer. Since there is no relatively brittle heat-resistant resin layer at the base of the support ring 34 to which stress is applied in this way, it is possible to prevent the support ring 34 from being chipped.

The thickness of the heat-resistant resin layers 35a to 35c is not particularly limited, but the heat-resistant resin layer becomes closer to the opening end.
It is preferable that the ratio occupied by 35 is large, and that almost all of the openings are made of heat resistant resin.

As the polyester resin forming the polyester layer of such a parison, a thermoplastic resin composed of saturated dicarboxylic acid and saturated dihydric alcohol can be used. Saturated dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-1,4- or 2,6-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenyldicarboxylic acids, diphenoxyethanediethanedicarboxylic acids And the like, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, decane-1,10-dicarboxylic acid and the like, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and the like can be used. As the saturated dihydric alcohol, aliphatic glycols such as ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, hexamethylene glycol, dodecamethylene glycol and neopentyl glycol are used. Glycols, alicyclic glycols such as cyclohexanedimethanol, 2,2-bis (4'-β-hydroxyethoxyphenyl) propane, and other aromatic diols can be used. As the polyester resin composed of such a saturated dicarboxylic acid and a saturated dihydric alcohol, it is preferable to use polyethylene terephthalate composed of terephthalic acid and ethylene glycol.

The above polyester resin has an intrinsic viscosity of 0.5 to
It has a value in the range 1.5, preferably 0.55 to 0.8. Such polyesters are also produced by melt polymerization and
Those that have been subjected to reduced pressure treatment or heat treatment in an inert gas atmosphere at a temperature of up to 250 ° C., or those that have reduced the content of oligomers and acetaldehyde which are low molecular weight polymers by solid-state polymerization are preferable.

As the heat-resistant resin, polyarylate, polycarbonate, polyethylene naphthalate, polyacetal, polysulfone, polyether ether ketone, polyether sulfone, polyether imide, polyphenylene sulfide, and a blend polymer of these resins and polyethylene terephthalate. , And a blend polymer between the above heat resistant resins, a blend polymer of two or more kinds of the above heat resistant resins with polyethylene terephthalate, a U polymer (manufactured by Unitika, a blend polymer of polyarylate and polyethylene terephthalate), etc. can do. Of these, polyarylate, U polymer, polycarbonate, and a blend polymer of polycarbonate and polyethylene terephthalate are particularly preferable.

In the case of a blend polymer of polyarylate and polyethylene terephthalate, polyarylate is 40
It is preferred that the polyethylene terephthalate is from 50 to 60% by weight and the polyethylene terephthalate is from 50 to 60% by weight.

In the present invention, the polyester resin in the mouth is crystallized by the heat treatment described later to form a multilayer structure of a crystalline layer of polyester and a non-crystalline layer of impact-resistant resin. Since the polyester resin becomes white when it is crystallized, it is preferable that the heat resistant resin is also white. Therefore, it is preferable to add a white pigment to the resin component (for example, polyarylate, U polymer, polycarbonate, etc.) that makes the injection molded product transparent. In that case, the addition amount of the white pigment is preferably 0.05 to 5 parts by weight with respect to 100 parts by weight of the resin component.

Further, among the blended polymers, there is a blended polymer that exhibits a white color (milky white) (for example, a blended polymer of polycarbonate and polyethylene terephthalate). In that case, for example, the polycarbonate is 20 to 60% by weight. The polyethylene terephthalate may be blended so as to be 40 to 80% by weight and used as it is.

In the polyester resin and heat-resistant resin used in the present invention, a stabilizer, a pigment, an antioxidant, a heat deterioration inhibitor, an ultraviolet deterioration inhibitor, and an antistatic agent are used within a range not impairing the object of the present invention. An appropriate amount of additives such as antibacterial agents and other resins can be added.

Next, a method for producing the heat resistant biaxially stretch blow molded bottle of the present invention using such a parison will be described.

The heat-resistant biaxially stretch blow-molded bottle of the present invention is basically a method of co-injection molding a polyester resin and a heat-resistant resin by the method exemplified in, for example, JP-A 1-294025, A parison having the above-described multilayer structure is manufactured by a so-called two-gate co-injection molding method in which a heat-resistant resin is injected from the side and a polyester resin is injected from the bottom, and the parison is biaxially stretch blow molded. However, the mouth portion is subjected to a heat treatment in the above step to crystallize only the polyester layer. There are the following two cases as the crystallization process of the mouth portion by this heat treatment. That is, there are a case where the heat crystallization treatment is performed at the parison stage and a case where the heat crystallization treatment is performed after the blow molding. In particular, it is preferable to perform the heat treatment at the parison stage because it is easy to perform the heat treatment.

When the heat crystallization treatment is performed at the stage of the parison, as shown in FIG. 4, a heating device such as a heating ring heater, a hot air heater or an infrared heater is provided on the outer circumference of the mouth of the parison 41.
Install 42, shield the lower part of the lower surface of the parison support ring with the shield 43, and
It is preferable to heat and hold at ˜150 ° C. for 1 to 5 minutes, especially 1.5 to 3 minutes.

The heat-resistant biaxially stretch blow-molded bottle manufacturing method of the present invention basically involves removing the parison from the mold and then subjecting it to heat treatment. The parison may be heated and crystallized by setting the temperature of the mold at a portion corresponding to the mouth in the molding mold to 135 to 170 ° C, particularly 140 to 150 ° C.

Using the parison thus obtained, biaxial stretching blow molding is carried out by a conventional method.
The heat resistant biaxially stretch blow molded bottle of the present invention can be manufactured.

When the bottle after blow molding is subjected to the heat crystallization treatment, first, the parison having the multilayer structure as shown in FIG. 3 at the mouth is biaxially stretch blow molded by a conventional method to obtain a parison. As in the case of the outer circumference of the bottle mouth, the heating device is installed and the lower part of the lower surface of the support ring is shielded, and 135 to 170 ℃, especially 140 to 150 ℃.
It is preferable to heat and hold for 1 to 5 minutes, especially 1.5 to 3 minutes.

When the mouth of a bottle is to be crystallized, a jig for preventing deformation is inserted into the inner diameter of the mouth of the bottle and then heat treatment is carried out. In the method of the present invention, the jig is used. Even if the bottle is not inserted, almost no deformation such as contraction of the bottle mouth occurs. Especially, the diameter of the mouth opening end is made by concentrating heat-resistant resin in the mouth (70% or more by volume composition ratio) Almost never changes.

This has a multilayer structure of a polyester layer and a heat-resistant resin layer, so that even if the polyester layer shrinks due to heat crystallization, the heat-resistant resin layer does not deform, so that it is substantially deformed (shrinks). It is thought that this is because it is impossible to do. In particular, in amorphous PET in the temperature range of 70 to 140 ° C. when the temperature rises and falls near the crystallization temperature,
It is considered that the heat-resistant resin is easy to be softened and deformed, but the heat resistant resin is hard to be softened and deformed in this temperature range, and thus the shape can be maintained.

The present invention has been described above with reference to the accompanying drawings. However, the present invention is not limited to this, and various modifications can be made without departing from the idea of the present invention. For example, the multi-layer structure of the mouth portion of the heat-resistant biaxially stretch blow-molded bottle (multi-layer structure of the mouth portion of the parison) may be made of a crystalline polyester layer and a non-crystalline heat-resistant resin layer, for example, as shown in FIG. It is possible to have various structures as shown in FIG.

The present invention will be described in more detail with reference to the following specific examples. Example 1 Polyethylene terephthalate (NEH-2050 manufactured by Unitika Ltd.) was used as the polyester resin. A heat resistant resin was prepared by adding 0.5 part by weight of a white pigment to 100 parts by weight of a blended polymer of polyethylene terephthalate and polyarylate (U Polymer 8450, manufactured by Unitika Ltd.).

Using the above polyester resin and heat resistant resin, a polyester resin and a heat resistant resin are respectively injected from the bottom side by publicly known co-injection molding to form a parison having a multi-layered mouth portion as shown in FIG. Was molded.

Next, the lower part of the support ring of this parison is shielded by a metal shielding plate having a cooling structure, and the mouth is heated at 140 ° C. by a heating ring heater and hot air.
The polyester resin in the mouth was crystallized by heating for 1.5 minutes. At this time, no deformation such as contraction of the opening end was observed at the mouth.

The parison thus obtained was biaxially stretch-blow-molded to manufacture a bottle with a milky white mouth and a full-filled volume of 1554 ml.

The bottle thus obtained was filled with hot water at 80 ° C., and after capping, a hot shower at 80 ° C. was further performed for 20 minutes. It had heat resistance.

Example 2 As polyethylene terephthalate, Mitsui Petrochemical Co., Ltd.
Manufactured by J135 was used. In addition, 30% by weight of the above polyethylene terephthalate and polycarbonate (Mitsubishi Kasei Co., Ltd.)
Manufactured by Novalex 7025A) 70% by weight was mixed in the form of pellets to obtain a material for injection molding the heat resistant resin layer.

Using the above-mentioned polyester resin and heat-resistant resin, the polyester resin and the heat-resistant resin are sequentially co-injected from the bottom side by publicly known co-injection molding, and the mouth portion of the multilayer structure as shown in FIG. 6 ( However, a parison having a polyester resin not yet crystallized) was molded. Here, the heat resistant resin layer had a milky white color.

Then, the lower part of the support ring of this parison was shielded by a metal shielding plate having a cooling structure, and the mouth was heated at 140 ° C. by a heating ring heater and hot air.
The polyester resin in the mouth was crystallized by heating for 1.5 minutes. At this time, no deformation such as contraction of the opening end was observed at the mouth.

The parison thus obtained was biaxially stretch-blow-molded to produce a bottle with a mouth-filled milky white color and a full-injection amount of 1550 ml.

The bottle thus obtained was filled with hot water at 80 ° C., and after capping, a hot shower at 80 ° C. was carried out for 1.5 minutes. No deformation or the like was observed at the mouth and sufficient heat resistance was obtained. It had a nature.

Example 3 As polyethylene terephthalate, manufactured by Mitsui Petrochemical, J
135 was used. As the heat resistant resin, polycarbonate (Novarex 7022A manufactured by Mitsubishi Kasei Co., Ltd.) was used.

Using the above polyester resin and heat resistant resin, the polyester resin and the heat resistant resin are sequentially co-injected from the bottom side, respectively, and the mouth portion of the multilayer structure as shown in FIG. 8 (however, the polyester resin is still crystallized) A parison having an unmodified).

Next, the lower part of the support ring of this parison was shielded by a metal shielding plate having a cooling structure, and the mouth was heated at 140 ° C. by a heating ring heater and hot air.
The polyester resin in the mouth was crystallized by heating for 1.5 minutes. At this time, no deformation such as contraction of the opening end was observed at the mouth.

The parison thus obtained was biaxially stretch blow-molded to produce a bottle with a mouth-filled milky white color and a full-injection amount of 1550 ml.

The bottle thus obtained was filled with hot water of 95 ° C., sealed with an aluminum screw cap, sterilized by overturning for 30 seconds, and then cooled with a hot water shower of 50 ° C., There was no sealing failure due to mouth deformation, torque reduction, etc., and it had sufficient heat resistance.

[0049]

As described above, according to the present invention,
By producing co-injection of polyester and heat-resistant resin to produce a parison with a multilayered mouth, heat treatment is applied to the mouth of this parison or blow molding bottle of this parison to crystallize the polyester resin, Since the bottle has a multi-layered structure having a crystalline polyester layer and an amorphous heat resistant resin layer, the obtained bottle has excellent heat resistance and impact resistance. In addition, the method for manufacturing a bottle has an advantage that the mouth portion is not deformed by the action of the heat-resistant resin even when a jig for preventing deformation is not inserted on the inner diameter side of the mouth portion during the heat treatment.
Further, since the complicated layer surfaces in a molten state are formed into multiple layers by co-injection, there is no separation or peeling between layers even in the crystallization step and subsequent use, and the strength is excellent.

The heat-resistant biaxially stretch blow-molded bottle of the present invention as described above is suitable as a bottle to which pasteurizing by hot fill or hot shower is applied.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a heat resistant biaxially stretch blow molded bottle of the present invention.

FIG. 2 is an enlarged view of the mouth portion of FIG.

FIG. 3 is a partial cross-sectional view showing an example of a parison that can be used to manufacture the heat resistant biaxially stretch blow molded bottle of the present invention.

FIG. 4 is a schematic view showing an example of a manufacturing process of the heat resistant biaxially stretch blow molded bottle of the present invention.

FIG. 5 is a partial cross-sectional view showing another example of the multilayer structure of the mouth portion of the heat resistant biaxially stretch blow molded bottle of the present invention.

FIG. 6 is a partial cross-sectional view showing another example of the multilayer structure of the mouth portion of the heat resistant biaxially stretch blow molded bottle of the present invention.

FIG. 7 is a partial cross-sectional view showing another example of the multilayer structure of the mouth portion of the heat resistant biaxially stretch blow molded bottle of the present invention.

FIG. 8 is a partial cross-sectional view showing another example of the multilayer structure of the mouth portion of the heat resistant biaxially stretch blow molded bottle of the present invention.

[Explanation of symbols]

 1, 31 ... Mouth portion 2 ... Shoulder portion 3 ... Body portion 4 ... Bottom portion 5, 34 ... Support ring 21, 35 ... Amorphous heat resistant resin layer 22 ... Crystalline polyester layer 32 ・ ・ ・ Screw part 33 ・ ・ ・ Support ring part 36 ・ ・ ・ Amorphous polyester layer 41 ・ ・ ・ Parison 42 ・ ・ ・ Heating device 43 ・ ・ ・ Shield body

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B29C 71/02 7344-4F B32B 1/02 7016-4F // B29K 67:00 B29L 9:00 4F 22:00 4F

Claims (6)

[Claims] 1. A mouth portion, a support ring provided at a lower end of the mouth portion, a shoulder portion following the support ring, a body portion, and a bottom portion, and the mouth portion includes a crystalline polyester layer. A heat-resistant biaxially stretch blow-molded bottle having a multilayer structure composed of an amorphous heat-resistant resin layer, wherein the crystalline polyester layer is crystallized by heating the amorphous polyester layer. A heat resistant biaxially stretch blow molded bottle characterized by: 2. The heat resistant biaxially stretch blow molded bottle according to claim 1, wherein the heat resistant resin is polycarbonate, polyarylate, a composition of polycarbonate and polyethylene terephthalate, or a composition of polyarylate and polyethylene terephthalate. A heat-resistant biaxially stretch blow-molded bottle characterized by being a product. 3. The heat-resistant biaxially stretched blow-molded bottle according to claim 1 or 2, wherein the opening end of the mouth portion is made of a transparent amorphous resin. Blow molded bottle. 4. A method for producing a heat-resistant biaxially stretch blow-molded bottle according to any one of claims 1 to 3, comprising: (a)
It has a mouth part having a multi-layer structure composed of an amorphous polyester layer and an amorphous heat resistant resin layer, a support ring provided at the lower end of the mouth part, a body part following the support ring, and a bottom part. Form a cylindrical parison with a bottom,
(b) By heat-treating the mouth portion, the amorphous polyester layer is crystallized, and (c) subsequently, the parison is biaxially stretch blow molded, which is heat resistant biaxial stretch blow molding. Bottle manufacturing method. 5. A method for producing a heat-resistant biaxially stretch blow-molded bottle according to any one of claims 1 to 3, comprising: (a)
It has a mouth part having a multi-layer structure composed of an amorphous polyester layer and an amorphous heat resistant resin layer, a support ring provided at the lower end of the mouth part, a body part following the support ring, and a bottom part. Form a cylindrical parison with a bottom,
(b) biaxially stretch blow molding the parison, (c) crystallizing the amorphous polyester layer of the mouth by heat-treating the mouth of the obtained biaxially stretch blow molded bottle. A method for producing a heat-resistant biaxially stretch blow-molded bottle, comprising: 6. The method for producing a heat-resistant biaxially stretch blow-molded bottle according to claim 4 or 5, wherein a jig is provided on the inner diameter side of the mouth portion to prevent deformation of the mouth portion during the heat treatment. A method for producing a heat-resistant biaxially stretch blow-molded bottle, characterized in that it does not. [0001]