JPH0468217B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a pressure-resistant container that is subjected to internal pressure, such as for carbonated beverages, and particularly improves pressure and heat resistance during heat sterilization of the contents, and improves storage stability at room temperature. The present invention relates to a pressure- and heat-resistant container with improved properties and a method for manufacturing the same.

(Prior Art) Conventionally, there are containers such as those shown in FIGS. 10 and 11, to which internal pressure is applied, such as for carbonated drinks. That is, 100 indicates the entire container, which is composed of a container body 101 having a generally hollow interior and a base cup 102 attached to a bottom portion 101A of the container body 101. Since internal pressure is applied to the container body 101, the bottom part 10 is designed to increase pressure resistance.
1A is rolled into a spherical shell shape, and the base cup 1
02 makes it possible to stand the container 100 upright. This container body 101 is made by preforming a bottomed cylindrical parison 103 made of a single layer structure of thermoplastic resin as shown in FIG. 12, and biaxially stretching blow molding this parison 103.
By causing crystal orientation in the resin material, the container body 101
It ensured pressure and heat resistance.

By the way, filling the contents into the container body 101 as described above can be carried out by hot filling the contents heated to 80 to 95°C into the container body 101, sealing it, and then filling it with a gas such as nitrogen. There is a method of filling the container body 101 with contents, capping the rear opening and neck portion 101B and sealing the container body 101, and then pouring boiling water into the container body 101 from above to heat sterilize the contents. In the latter case, heat sterilization of carbonated drinks, etc. is legally required to be carried out at 65°C for 10 minutes or more, and the container body 101 must be heat resistant and able to withstand the internal pressure during heating. Pressure resistance was required.

(Problems to be Solved by the Invention) However, in such conventional technology, when the container body 101 has a single-layer structure of thermoplastic resin such as polyester or polypropylene, gas barrier properties (gas barrier performance) are low, and the container body 101 has a low gas barrier property (gas barrier performance), and may be affected by the contents. In addition, resins with excellent gas barrier properties such as ethylene-vinyl alcohol copolymers and special polyamides are difficult to stretch and blow mold, resulting in high costs. A new occurrence. As described above, in a single-layer structure made of thermoplastic resin such as polyester or polypropylene, if the filled content is a fruit juice drink, the container body 101
Oxygen enters the container and the contents oxidize, causing the fruit juice to change color and lose its taste. On the other hand, when the content is a carbonated beverage, in addition to a change in color and a decrease in taste, carbon dioxide gas is gradually discharged, resulting in a significant decrease in flavor. Therefore, conventional containers have had the problem of poor storage stability.

Furthermore, in the above conventional technology, the container body 10
By biaxially stretching blow molding 1, the resin material is stretched and has strength and heat resistance, but there are burrs etc. when the parison 103 was injection molded near the center of the bottom 101A of the container body 101. However, it is not sufficiently stretched during blow molding, and the effect of crystal orientation by stretching is small. Therefore, the strength tends to be weak and there is a risk of damage due to impact such as dropping. In addition, there was a problem in that the center area of the bottom 101A of the container body 101 was softened by the heat generated during heat sterilization, causing the bottom 101A to partially protrude, resulting in a loss of commercial value. FIG. 13 shows how the Young's modulus of the resin changes depending on temperature in the stretched state and unstretched state.
It can be seen that the strength of the unstretched portion decreases rapidly at around 65°C. Around 65°C is also a legally regulated temperature, and the bottom 101A of the container body 101 is required to be strengthened.

Therefore, as shown in FIG. 14, the parison 103'
The bottom wall portion 103A' of the container body 101 after blow molding is heated partially in advance to thermally crystallize it.
It has also been proposed to strengthen the center of the bottom 101A (see Japanese Patent Laid-Open No. 148441/1983). However, when the parison 103 is simply blow-molded, the bottom 101A of the container body 101 has a continuous wall thickness at the boundary between the crystallized region α and the stretched region β of the bottom wall 103A' of the parison 103, as shown in FIG. This results in a low stretch region γ that is not sufficiently stretched at the boundary. Therefore, there is a risk that the low-stretch region may swell during heat sterilization, and there are still limits to pressure resistance and heat resistance.

The present invention has been made in order to solve the problems of the prior art described above, and its purpose is to provide a pressure- and heat-resistant container that can improve storage stability and withstand heat sterilization at high temperatures, and a method for manufacturing the same. It's about doing.

(Means for Solving the Problems) In order to solve the above object, the pressure and heat resistant container according to the present invention is a pressure and heat resistant container in which the container body is made hollow inside by biaxial stretch blow molding.
At least the trunk and shoulder portions of the container body are constructed of a laminate consisting of inner and outer surface layers made of oriented crystalline resin and at least an intermediate layer having a gas barrier resin, and at least a portion of the bottom portion of the container body is A thermally crystallized portion is provided, and the entire region other than the thermally crystallized portion at the bottom is stretched at a high stretching ratio to form a highly stretched portion thinner than the thermally crystallized portion, and The bottom of the container body has a curved surface that swells in a convex shape toward the outside of the container body, and the thermal crystallization portion is configured to protrude toward the inner peripheral surface of the bottom,
It is characterized in that the position where the highly stretched portion is joined to the thermally crystallized portion is the outer end position of the thermally crystallized portion in the thickness direction.

Further, in the method for manufacturing a pressure- and heat-resistant container according to the present invention, first, a cylindrical parison with a bottom is formed from a laminate consisting of inner and outer surface layers made of oriented crystalline resin and an intermediate layer having at least a gas barrier resin. In the method for producing a pressure- and heat-resistant container, the method for producing a pressure- and heat-resistant container comprises thermally crystallizing at least a portion of the bottom of the parison, and then stretching a region other than the thermally crystallized region of the parison to form a container body. For areas adjacent to the thermally crystallized area, the blow molding pressure causes the material to flow outward in the wall thickness direction along the edge of the thermally crystallized area and is pressed against the inner circumferential surface of the mold. All are characterized in that the container body is formed by stretching at a high stretching ratio.

(Function) In the present invention having the above configuration, at least the body and shoulder portions of the container body are made of a laminate comprising inner and outer surface layers made of oriented crystalline resin and an intermediate layer having at least gas barrier resin. Because of this structure, gas barrier properties are improved and delamination resistance is excellent, and oxygen and the like do not enter the inside of the container body, and internal gas is not discharged. In addition, the bottom of the main body of the container has a curved surface that bulges outward, and the thermally crystallized portion is configured to protrude toward the inner peripheral side of the bottom. By setting the outer end position of the thermally crystallized portion in the thickness direction, the material in the vicinity of the thermally crystallized portion can be caused to flow so as to be scraped off along the edge of the thermally crystallized portion by blow molding pressure, By eliminating the low stretching region, all regions other than the thermally crystallized portion can be stretched at a high stretching ratio. In this way, the bottom of the container body is entirely made up of a thermally crystallized region with excellent heat resistance and pressure resistance, and a highly stretched region.
The shape of the bottom of the container body is maintained even when high internal pressure is applied in a high temperature atmosphere during heat sterilization.

(Example) The present invention will be explained below based on the illustrated example. FIGS. 1 to 4 show an embodiment of the pressure- and heat-resistant container of the present invention. In Figure 1 A, 1
1 shows the entire container, and this container 1 is composed of a container body 2 having a hollow interior and a base cup 3 attached to a bottom portion 2B of this container body 2.

As shown in FIG. 1B, the container body 2 is composed of a laminate consisting of inner and outer surface layers 1A and 1B made of oriented crystalline resin and an intermediate layer 1C made of gas barrier resin. There is. The above-mentioned oriented crystalline resin is selected from polypropylene resin, polyester resin (in this example, PET), acrylnitrile (AN) resin, etc., and the gas barrier resin is selected from ethylene-vinyl alcohol copolymer (EVOH), methane resin, etc. Selected from xylidene adipamide (MX nylon), barrier polyester (B resin), etc. In this embodiment, the inner and outer surface layers 1A and 1B are made of PET, and the intermediate layer 1C is made of barrier polyester. The inner and outer surface layers 1A and 1B are continuous in the surface direction over the entire area of the container body 2, and the intermediate layer 1C is also configured to be continuous in the surface direction over the entire area of the container body 2.

The container body 2 includes a cylindrical body 2A, a shoulder 2C and a mouth and neck 2D that are continuously molded above the body 2A, and a ball that is continuously provided at the lower end of the body 2A and faces downward. The bottom part 2B protrudes like a shell.

As shown in FIG. 3, the bottom portion 2B of the container body 2 is partially crystallized by heat to form a thermally crystallized portion 4 at its center. All regions other than the thermally crystallized portion 4 are thinly stretched at a high stretching ratio to form a highly stretched portion 5. The crystallized portion 4 has a planar shape centered on the center point O of the bottom portion 2B (the point where the central axis X of the container body 2 intersects with the bottom portion 2B), and the wall thickness t ₁ is equal to the wall thickness t ₂ of the highly stretched portion 5. It is thicker than the . The thermally crystallized portion 4 is in an unstretched, non-oriented crystalline state, has strong strength, and maintains a stable state. Normally, the material crystallizes at temperatures above about 100°C to 140°C, forming spherulites and exhibiting a milky white color.

Further, in the highly stretched portion 5, crystal orientation occurs inside the material due to the stretching action of the material, resulting in strong strength and excellent shape retention. Crystal orientation is caused by stretching the film under heating, usually at 70°C to 140°C, preferably 90 to 110°C.

In this embodiment, the thickness t ₁ of the thermally crystallized portion 4 is
3.5 [mm], and the thickness t ₂ of the highly stretched portion 5 is approximately 0.35 [mm]. The highly stretched portion 5 is continuous with the body portion 2A, and is formed to be slightly thicker than the body portion 2A.

At the boundary between the thermally crystallized portion 4 and the highly stretched portion 5, the highly stretched portion 5 extends from the side edge of the thermally crystallized portion 4, and the bonding position is in the thickness direction of the thermally crystallized portion 4. It is at the outer end position. Therefore, the thermally crystallized portion 4 protrudes toward the inner peripheral surface of the bottom portion 2B of the container body 2 by the thickness of the thermally crystallized portion 4, and a step is formed at the boundary between the thermally crystallized portion 4 and the highly stretched portion 5. 6 is formed.
This step 6 is minimized in this embodiment.

Furthermore, in this embodiment, the mouth and neck portion 2D is also thermally crystallized to enhance strength and heat resistance. That is, the mouth and neck part 2D has a thick cylindrical shape, and the upper edge of the shoulder part 2C, which is continuously extended from the body part 2A and has a high extension, is connected to the outer edge of the lower end surface 7 of the mouth and neck part 2D.

Further, the base cup 3 has a generally bottomed cylindrical shape, and the diameter of the circumference 31 is approximately the same as the outer diameter of the body portion 2A of the container body 2. The bottom wall 32 is provided with an annular pedestal 33 that is formed concentrically with the peripheral wall 31 and is adhesively fixed to the bottom 2B of the container body 2. On the other hand, the upper end of the peripheral wall 31 is locked to the lower edge of the body 2A of the container body 2, and the upper end of the peripheral wall 31 is provided with hot water in a space S formed between the base cup 3 and the bottom 2B of the container body. A plurality of openings 34 are provided in the circumferential direction to allow circulation. Vent part 34
... is formed by providing a plurality of longitudinal grooves 35 ... recessed radially inward in the circumferential wall 31 in the circumferential direction to form unevenness on the upper end of the circumferential wall 31 of the base cup 3, and the unevenness creates a gap between the base cup 3 and the container body 2. It is made up of gaps formed between.

In this example, the container body 2 is a laminate composed of inner and outer surface layers 1A and 1B made of PET and a gas barrier layer 1C made of barrier polyester.
The body part 2A and the shoulder part 2C of the container body 2 are made to be continuous in the surface direction over the entire area, but in addition to this, the body part 2A and shoulder part 2C of the container body 2 except at least one of the mouth and neck part 2D or the bottom part 2B.
may be composed of the above-mentioned laminate.

In addition, in this example, the laminate is made of PET.
Although it is composed of three layers of two types: the outer surface layers 1A, 1B and the gas barrier layer 1C made of barrier polyester, for example, the inner surface layer 1A may be made of PET,
On top of that, barrier polyester, PET or regrind layer, barrier polyester, and PET as the outer surface layer 1B may be laminated in order to form a 2-type, 5-layer structure, or the inner surface layer 1A is PET and An adhesive, an ethylene-vinyl alcohol copolymer or metaxylidene adipamide, an adhesive, and PET as an outer surface layer may be laminated in order to form a five-layer structure of three types. Furthermore, the inner surface layer 1A is made of PET,
On top of that, a regrind layer, an adhesive, an ethylene-vinyl alcohol copolymer or metaxylidene adipamide, an adhesive, a regrind layer, and a PET serving as an outer surface layer are laminated in order, and a 7-layer structure of 4 types may be used. ,
In this case, a four-layer, six-layer structure may be used, except for the regrind layer on the outer surface layer side. Here, as the adhesive, a polyamide adhesive or the like is used.
Whether or not a polyamide adhesive is used in the structure of these laminates is determined by whether the adhesive is homologous to PET or not. That is, when barrier polyester is used for the gas barrier layer 1C, since it is a homologous polyester, it has interlayer adhesion and no adhesive is required.
Further, as the regrind layer, a layer made of recycled burrs or the like is used.

According to the pressure-resistant and heat-resistant container of this embodiment configured as described above, the gas barrier property is improved because the container body 2 has a multilayer structure, and when the content is a carbonated beverage, carbon dioxide gas is not discharged. The flavor does not deteriorate and the color does not change. Furthermore, even when the content is a fruit juice drink, the original color and flavor of the fruit juice drink are maintained for a long period of time without oxidation.

Next, we will discuss the method for manufacturing the above-mentioned pressure- and heat-resistant container.
This will be explained based on FIGS. 9 to 9.

First, as shown in FIG. 6, a parison 10 for stretch molding is preformed with a laminate consisting of inner and outer surface layers 1A and 1B made of oriented crystalline resin and an intermediate layer 1C made of gas barrier resin. The parison 10 is a material that is preliminarily formed to biaxially stretch blow mold the container body 2, and mainly consists of a cylindrical portion 10A that will become the body 2A of the container body 2, and a
The bottom wall portion 10B that should become the bottom portion 2B of the cylindrical portion 1
It is constituted by a bottomed cylindrical member consisting of a mouth and neck part 2D connected to the upper end of 0A.

The parison 10 is manufactured, for example, by injection molding as shown in FIG. That is, 20
is a mold, in which molten resin is injected into the cavity 21 of a closed mold 20 from an injection nozzle (not shown) through a gate 22, and after hardening, the mold is opened and a molded product 10' is taken out.

Next, the mouth and neck part 2D and the bottom wall part 1 of the parison 10'
0B′ is heat-treated and thermally crystallized to form a thermally crystallized region.
Form G1 and G2. The crystallized region G1 provided in the mouth and neck part 2D' extends over the entire mouth and neck part 2D', and the bottom wall part 1
The crystallized region G2 provided at 0B is also formed over substantially the entire surface of the bottom wall portion 10B. The entire thickness of each of the crystallized regions G1 and G2 is heat treated.

Next, using the parison 10 described above, the container body 2 is
The molding process of blow molding will be explained based on FIGS. 8A and 8B. In the figure, 11 is a mold for blow molding, and this mold 11 generally includes a mold 11A for molding the body 2A of the container body 2, a bottom mold 11B for molding the bottom 2B of the container body, and a mouth and neck part of the container. It consists of a neck mold 11C for molding 2D.
On the other hand, reference numeral 12 denotes a stretching rod for stretching the parison 10 in the direction of its axis X, and it can freely move in and out of the parison 10 mounted in the mold 11 from the mouth and neck 2D side by a drive source (not shown). inserted. A fluid passage 13 through which a fluid such as compressed air passes is provided in a space between the stretching rod 12 and the inner surface of the parison 10.

Blow molding is performed in the above apparatus as follows. First, the stretching temperature (in the case of polyester,
(In this example, the inner and outer surface layers 1A and 1B are PET) 70
Parison 10 heated to ~140 [℃]) was placed in the 8th
As shown in Figure A, the stretching rod 12 is extended and stretched in the axial direction. In this state, mainly parison 10
The cylindrical portion 10A is stretched in the axial direction to a stretching ratio of 2.2 or more. Furthermore, as shown in FIG.
Compressed air is sucked under high pressure through the fluid passage 13 around the parison 10, and the cylindrical portion 10A of the parison 10 expands radially outward and comes into close contact with the inner surface of the mold 11. On the other hand, the bottom wall portion 10B also expands outward in the radial direction while becoming thinner from the vicinity of its center point O', and its outer surface closely contacts the inner surface of the bottom mold 11B. In this state, the cylindrical portion 10A of the parison 10 is stretched mainly in the circumferential direction to a stretching ratio of 3 or more. Further, the bottom wall portion 10B is
The portion of the crystallized region G1 hardly changes depending on the temperature, and the amorphous portion continuous to the crystallized region G1 is stretched. Further, the crystallized region of the mouth and neck region 2D is not stretched either, but the amorphous portion connected to the crystallized region G1 is stretched. In this way, the amorphous portions other than the crystallized regions G1 and G2 of the parison 10, mainly the cylindrical portion 10A in this embodiment, are heated and stretched to produce sufficient crystal orientation, and the body portion 2A and the shoulder portion 2 of the container body 2 are heated and stretched.
C, and further the highly stretched portion 5 other than the crystallized portion 4 of the bottom portion 2B.
Configure.

FIGS. 9A to 9C show the stretched state of the parison bottom wall portion 10B during blow molding. That is, the crystallization region G2 is caused by the gas pressure of compressed air.
The amorphous portion adjacent to is stretched, and the amorphous portion flows outward along the edge of the crystallized region G2, creating a step 6 at the edge of the crystallized region G2. All parts are stretched at high draw ratios to become thin. Here, it is desirable that the step 6 be minimized. In the bottom part 2B of the container body 2, the crystallized region G2 remains in the shape of the bottom wall part 10B of the parison 10 before blow molding, and becomes the crystallized part 4 at the center of the bottom part 2B. And the crystallized part 4 of the bottom part 2B
The other portions are highly stretched substantially uniformly with the body 2A of the container body 2 to form a highly stretched portion 5.

On the other hand, at the boundary between the lower end of the mouth and neck part 2D of the parison 10 and the cylindrical part 10A, the amorphous part of the cylindrical part 10A is also scraped along the edge of the crystallized region G1 due to the blow pressure during blow molding. It flows outward as if falling, a step is created at the edge of the crystallized region G1, and the shoulder portion 2C, which becomes the mouth and neck portion 2D of the container body 2, is highly stretched and sufficient crystal orientation occurs.

When the molding of the container body 2 is completed, the base cup 3 is attached to the bottom portion 2B of the container body 2 and fixed with adhesive on the pedestal portion 33, thereby completing the container 1.

In the above embodiment, the parison 10 was manufactured by injection molding, but it may also be manufactured by extrusion molding.

Next, a case will be described in which the container 1 formed in this manner is filled with a carbonated beverage or the like and the contents are heated and sterilized. Heat sterilization of the contents is carried out by pouring boiling water from the top of the container 1 after filling the container 1 with the contents and capping the container. In this example, hot water at 75°C is poured into the upper part of the container 1. The hot water flows downward along the outer peripheral surface of the body 2A of the container body 2 and heats the contents through the wall surface of the container body 2. On the other hand, the hot water that has flowed to the lower end of the body 2A enters the inside of the base cup 3 through the opening 34 formed in the base cup 3, and flows downward along the spherical outer peripheral surface of the container body bottom 2B. The temperature of the hot water in this bottom portion 2B is approximately 65°C. On the other hand, the gas pressure inside the container body 2 increases due to heating, and the container body 2 is exposed to high temperature and high pressure.
Since B is composed only of the highly stretched part 5 with sufficient crystal orientation and the crystallized part 4 crystallized by heating, there is no risk of softening even when hot water is poured over it, and it has excellent heat resistance and pressure resistance. temperature constraints are reduced. Incidentally, when crystallized in this way, the heat resistance temperature is 80 to 95 [℃], and the pressure resistance is 8 to 95 [℃].
It will be ^about 10Kg/cm2. Therefore, sterilization at higher temperatures is possible, and the range of use can be expanded. At this time, since the container body 2 is constructed of a laminate as described above, it has excellent gas barrier properties and maintains a sterilized state over a long period of time.

(Effect of the invention) The present invention consists of the above structure and operation,
Since at least the trunk and shoulders of the container body are constructed of a laminate consisting of inner and outer surface layers made of oriented crystalline resin and at least an intermediate layer containing gas barrier resin, it has excellent gas barrier properties and is suitable for fruit juice drinks. In the case of carbonated drinks, there is no deterioration in flavor or change in taste due to gas loss in the case of carbonated drinks, and the shelf life at room temperature can be greatly improved. In addition, the bottom of the container body has a curved surface that bulges outward, and the central part of the container body, which is not sufficiently stretched during stretch blow molding, is thermally crystallized to form a thermally crystallized portion, and this thermally crystallized portion is formed inside the bottom. It has a structure that protrudes toward the circumferential side, and the joining position of the highly stretched part with the thermally crystallized part is at the outer end position of the thermally crystallized part in the thickness direction, so that the material in the vicinity of the thermally crystallized part is not blown away. The molding pressure allows the material to flow so as to be scraped along the edges of the thermally crystallized area, and all areas other than the thermally crystallized area can be stretched at a high draw ratio. Therefore, the heat resistance and pressure resistance of the container body can be improved, and it is possible to realize a highly versatile pressure and heat resistant container that can be used as a container for various contents that require high sterilization temperatures.
In addition, although at least the shoulder portion and the body portion are biaxially oriented, the film has excellent delamination resistance. Further, according to the container manufacturing method of the present invention, the container can be manufactured extremely easily and at a reduced cost, even though the gas barrier properties are improved.

[Brief explanation of the drawing]

FIG. 1A is a partially cutaway enlarged front view showing the overall structure of a pressure- and heat-resistant container according to an embodiment of the present invention, FIG. 1B is an enlarged cross-sectional view of section A in FIG. Figure 3 is a partially cutaway front view showing the bottom of the main body of the container in Figure 1; Figure 3 is a partially cutaway enlarged front view of the bottom of the container in Figure 1;
The figure is a partially cutaway enlarged front view of the mouth and neck of the container shown in FIG. 1, and FIGS. The figure is a partially cutaway front view of the parison before the heat crystallization treatment, Figure 6 is a partially cutaway front view of the parison after the heat crystallization treatment, and Figure 7 is the front view of the parison before the heat crystallization treatment.
8A and 8B are schematic vertical sectional views of a blow molding die showing a state in which a container body is blow-molded using the parison in FIG. Figures 9A to 9C are enlarged cross-sectional views showing the stretched state of the bottom wall of the parison during blow molding, Figure 10 is a partially cutaway cross-sectional view showing the conventional overall configuration, and Figure 11 is a base cup of the container shown in Figure 10. 12 is a longitudinal cross-sectional view of the parison for molding the container body in FIG. 10;
The figure is a graph showing the temperature dependence of the strength of the unstretched part and the stretched part of the resin, Fig. 14 is a longitudinal cross-sectional view showing an example of the parison of Fig. 12 subjected to heating crystallization treatment, and Fig. 15
The figure is an enlarged cross-sectional view of the bottom of the container after the parison of FIG. 14 has been stretch-blown. Explanation of symbols, 1...Container, 1A...Inner surface layer,
1B... Outer surface layer, 1C... Intermediate layer, 2... Container body, 2A... Body, 2B... Bottom, 2C... Shoulder, 4... Thermal crystallization part, 5... Highly stretched part , 10...
...Parison, 11...Mold, G1, G2...Crystallization region.

Claims (1)

[Scope of Claims] 1. A pressure- and heat-resistant container having a hollow interior formed by biaxial stretch blow molding, wherein at least the body and shoulder portions of the container body are made of inner and outer material made of oriented crystalline resin. It is composed of a laminate consisting of a surface layer and an intermediate layer having at least a gas barrier resin, and at least a thermally crystallized portion partially thermally crystallized is provided at the bottom of the container body, and the thermally crystallized portion of the bottom is thermally crystallized. Stretching all regions other than the section at a high stretching ratio to form a highly stretched section that is thinner than the thermally crystallized section, and forming the bottom section of the container body into a curved surface that swells in a convex shape toward the outside of the container body. , the thermally crystallized portion is configured to protrude toward the inner circumferential surface side of the bottom, and the position where the highly stretched portion is joined to the thermally crystallized portion is the outer end position of the thermally crystallized portion in the thickness direction. A pressure- and heat-resistant container. 2. A cylindrical parison with a bottom is formed from a laminate consisting of inner and outer surface layers made of oriented crystalline resin and an intermediate layer having at least a gas barrier resin, at least the bottom of the parison is thermally crystallized, and then the parison is heated. In the method for manufacturing a pressure- and heat-resistant container in which the container body is formed by stretching all regions other than the thermally crystallized region, in the area adjacent to the thermally crystallized region at the bottom of the parison, the thermally crystallized region is stretched by blow molding pressure. The container body is formed by flowing the material outward in the wall thickness direction along the edge and pressing it against the inner peripheral surface of the mold, and stretching all areas other than the thermally crystallized area at a high stretching ratio. A method for manufacturing a pressure- and heat-resistant container.