JPH082583B2 - Heat-resistant multi-layer container manufacturing method and blow molding apparatus - Google Patents

Description

The present invention relates to a method for producing a multilayer stretch blow container and a blow molding apparatus.

[Conventional technology]

In recent years, heat-resistant resins such as U polymer (Unitika's blend polymer of polyacrylate and polyethylene terephthalate) have been used for polyethylene terephthalate (PE
A technique for obtaining a heat resistant bottle by co-injecting with T) and then stretch blow molding has been developed.

Further, in place of the conventional method of stretch blow molding using blow air at about room temperature, the mold components for blow molding surrounding the parison to be blow molded are closed, and before adiabatic expansion,
That is, the temperature before passing through the valve that controls the supply of blow air to the blow pipe is about 100-400 ° F (38-204 ° F).
There is disclosed a blow molding method in which heated and pressurized blow air in the range of (° C.) is injected into a parison and biaxially stretched (see Japanese Patent Publication No. 61-58288).

[Problems to be solved by the invention]

However, there are the following problems in co-injecting a heat resistant resin together with PET to impart heat resistance to PET and stretch blow molding.

For example, the U polymer that can be used as a heat resistant resin and PET have different stretching suitability temperatures.

Then, U polymer and PET having different stretching suitability temperatures are co-injected, the multi-layer parison is heated to the stretching suitability temperature of PET, and stretch blow molding is performed using cold blow air by a conventional method. The so-called whitening phenomenon occurs in the center of the chest of the bottle. On the other hand, whitening can be eliminated by heating the multi-layer parison to a suitable temperature for stretching the U polymer and then stretch-blow molding, but the uneven thickness of PET during stretching becomes remarkable. Crystallization impairs transparency.

In this way, the manufacturing process of stretch-blowing a multi-layer parison of heat-resistant polymer and PET to obtain a stretch-blown bottle is carried out under severe restrictions on the parison temperature.

Not only that, but in the multi-drawing production process of stretch blow bottles, among others, when producing stretch blow bottles by the so-called hot parison method that is performed in a series of continuous processes of injection molding of parison, temperature control, and stretch blow molding. ,
It is difficult to co-inject a large number of parisons under uniform conditions and evenly control the temperature.

Further, instead of the conventional method of stretch blow molding using blow air at about room temperature, in the case of stretch blow molding using superheated pressure blow air described in JP-B-61-58288,
It is necessary to heat the air higher in consideration of the temperature drop of the blow air due to adiabatic expansion cooling. Therefore, not only is the energy efficiency low, but hot air is supplied to the plenum under pressure through a compressor, and heated and pressurized blown air is blown into the parison from the plenum through the valve between the plenum and the blow pipe. It will be a big deal.

[Means for solving problems]

The present inventor has conducted research to eliminate the difficulties of the above-described multi-layer bottle, and as a result, a multi-layer parison having a heat-resistant resin layer as an intermediate layer and the heat-resistant resin layer being biased to the inside of the molded article. In the method for producing a heat-resistant multi-layer container by molding and stretch-blow molding the multi-layer parison, the multi-layer parison is maintained in a state where the surface temperature of the male mold of the injection mold for parison molding is kept higher than the surface temperature of the female mold. According to the method of co-injection molding, then adjusting the temperature so that the inside of the parison is at a higher temperature than the outside, and then blowing heated and pressurized blow air into the parison to perform stretch blow molding to prevent whitening and uneven distribution. It has been found that stretch blow molding can be performed without producing meat or the like.

However, if the heating and pressurizing blow air is supplied into the parison according to the method described in the above publication, the equipment becomes large in scale and the energy utilization efficiency becomes poor.

In order to overcome this drawback, research has shown that after the valve that controls the injection of blow air into the parison, that is, when the blow air is injected into the blow mandrel through the valve, or after the injection, the parison is heated and then heated. It was found that the blow-molding method does not require large-scale equipment and the stretch-blow molding is performed by effectively using energy, and based on such knowledge, the first invention relating to the method for producing a heat-resistant multi-layer container is provided. It has been completed.

That is, the first aspect of the present invention is that "a heat-resistant resin layer having a heat-resistant resin layer as an intermediate layer, and the heat-resistant resin layer is offset to the inside of a molded article is formed, and the multi-layer parison is stretch blow-molded. In the method for producing a multi-layer container, the multi-layer parison is co-injection-molded in a state where the surface temperature of the male die of the injection mold for parison molding is kept higher than the surface temperature of the female die, and then the inner side of the parison is the outer side. A method for producing a heat-resistant multi-layer container, which comprises subjecting the temperature to a temperature higher than that of the above temperature, and then blowing heated and pressurized blow air heated during or after adiabatic expansion into the parison for stretch blow molding. ] Is the gist.

Furthermore, as a result of research on the blow molding apparatus that implements the above manufacturing method, if the pressure blow air is heated by a spiral heater, it is possible to efficiently heat the pressure blow air that has been adiabatically expanded and cooled. Is not generated, and the temperature of the blowman drel cylinder is measured, high-pressure air is measured, and the heater is controlled based on the temperature measurement results, so that heated and pressurized blow air is supplied under almost the same conditions. Based on such knowledge, the second invention relating to the blow molding apparatus has been completed.

That is, the second invention is "a blow molding die, a cylindrical blow mandrel connected to the blow molding die, and a blow provided above the blow mandrel so as to enclose the blow mandrel upper portion. With airtight slide sleeve for sealing the open ends of the block and the blow mandrel and for supporting the stretch rod, and with a stretch rod slide sleeve for supporting the stretch rod provided near the lower part inside the blow mandrel and with the air tight In a blow molding device comprising a slide sleeve and a stretch rod positioned at the center of the blow mandrel by a slide sleeve, a spiral heater is built in the blow mandrel, and a temperature for controlling the blow mandrel temperature is provided. It has a sensor and a temperature sensor for high pressure air temperature measurement, A tubular stretch rod cover sleeve is provided between the stretch rod and the heater, and a passage for penetrating the blow block and the blow mandrel to supply high-pressure air between the blow mandrel and the stretch rod cover sleeve. Is provided, the high-pressure air injection pipe is connected to the blow block through the joint of the high-pressure air injection pipe so as to be connected to the passage, and the high-pressure air injection pipe is connected to a device that supplies high-pressure air via an electromagnetic valve. The blow molding device is characterized in that ] Is the gist.

 Hereinafter, the present invention will be described in detail.

First, as shown in the first figure, the heat-resistant resin layer (1) as an intermediate layer and the polyethylene terephthalate layer (2) as a main resin layer are formed. Mold the multi-layer parison.

Here, as the heat resistant resin layer, U polymer (manufactured by Unitika, blended polymer of polyarylate and polyethylene terephthalate), polycarbonate, blended polymer of polycarbonate and polyethylene terephthalate, blended polymer of polyarylate, polycarbonate and polyethylene terephthalate, etc. may be applied. .

Next, the polyethylene terephthalate resin used in the present invention means terephthalic acid or its ester-forming derivative (for example, lower alkyl ester, phenyl ester, etc.) and ethylene glycol or its ester-forming derivative (for example, monocarboxylic acid ester, ethylene oxide, etc.). Is a polyester obtained by polymerizing
Less than 20 mol% of other dicarboxylic acid or glycol moieties may be copolymerized. Further, the polyester may be copolymerized with a polyfunctional compound such as trimethylolpropane, pentatrisitol, trimellitic acid and trimesic acid in an amount of less than 2 mol%. The other dicarboxylic acid component used as the copolymerization component is phthalic acid,
Aromatic dicarboxylic acids such as isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acids, diphenoxyethane dicarboxylic acids, adipic acid, sepatic acid,
Examples thereof include aliphatic or alicyclic dicarboxylic acids such as azelaic acid, decanedicarboxylic acid, dichlorohexanedicarboxylic acid and the like.

Other glycol components used as other copolymerization components include aliphatic or alicyclic compounds such as trimethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, dodecamethylene glycol and cyclohexanedimethanol. Examples thereof include glycols, bisphenols, hydroquinone, 2.2-bis (4-β-hydroxyethoxyphenyl) propane and other aromatic diols.

It is also possible to use other oxyacids such as β-hydroxyethoxybenzoic acid and α-oxycaproic acid. It is also possible to use lower alkyl esters of these oxyacids and other ester-forming derivatives.

Next, after solidifying by rapid cooling and solidification in the parison injection molding mold that kept the surface temperature of the male mold higher than the surface temperature of the female mold,
Adjust the temperature. At this time, as shown in the second drawing, the area (5) outside the parison of the polyethylene terephthalate layer and the area (7) located inside thereof are adjusted to near the temperature suitable for stretching polyethylene terephthalate, that is, 95 to 120 ° C. ,
The temperature of the heat resistant resin layer (6) and the polyethylene terephthalate layer (4) inside the parison are adjusted to about the temperature suitable for stretching the heat resistant resin layer, for example, 120 to 135 ° C when the heat resistant resin layer is made of U polymer 8400.

That is, the temperature is adjusted so that the outside of the parison is relatively cooler than the inside.

As a method of controlling the temperature in this manner, the outer wall of the parison is contact-cooled with a temperature control type, or a method of cooling the outer wall of the parison in a temperature control pot that is cooled and held at a relatively lower temperature than the parison with cooling air, or A method of heating the inside of the parison with a heater, a method of heating the inside of the parison by circulating heated air, or a combination of the above methods can be employed.

FIG. 3 shows an example of a parison temperature control device applicable to the present invention.

In the figure, 50 is a temperature control type, 51, 52, 53, 54 are temperature control zones divided, 55 is a temperature control medium flow path, 56 is a rod heater,
57 is a heater holder, 58 is a heating core, 59 is a heater holder lower fixed bush, 60 is a heater holder upper fixed bush, 61 is a heating piece, 62 is a fixed block, 63 is a heater fixed block, 64 is an air blow passage, and 65 is Pressurized air flow tube, 66
Is a processing air control valve, 67 is a first zone temperature controller, 68 is a second zone temperature controller, 69 is a third zone temperature controller, 70
Is a fourth zone temperature controller, 71 is a temperature control medium flow tube, and 72 is an airtight O-ring.

The pressurized air is blown into the parison (3) heated above the softening temperature from the pressurized air flow pipe (65), and the outside of the parison (3) is attached to the inner surface of the temperature control mold (50) divided into four zones. Contact.

The rod heater (56) and the heating piece (61) attached to the rod heater relatively heat the inner surface of the parison and relatively cool the outer surface of the parison.

After the temperature is adjusted as described above, the parison is transferred to a blow molding device and blown with heated and pressurized blow air heated during or after adiabatic expansion into the parison to perform stretch blow molding, thereby causing no whitening and biasing. Stretch blow molding can be satisfactorily performed without producing meat.

Thus, it is desirable that the temperature of the hot-pressurized blown air is 30 ° C. or higher and the suitable temperature for stretching the heat-resistant resin or lower, for example, 120 ° C. or lower when the U polymer is used as the heat-resistant resin.

The optimum temperature of the heating / pressurizing blow air depends on the temperature of the temperature-controlled parison, but is 60 to 110 ° C., and the best stretch-blowing stability is obtained in this temperature range.

The mold of the blow molding device is heated to 90 to 110 ° C., but when the heat treatment is performed in a step different from the blow molding, it is not necessary to heat it.

In addition, the mold of the blow molding machine is heated to 90-110 ° C,
Continue heat treatment in the same mold, or adjust the temperature of the mold to a base temperature of 70 ° C or higher and 20 ° C or higher lower than the melting point to hold the molded product in the mold while holding the rod heater. More infrared rays are emitted, and hot air is emitted,
After circulating the inside of the molded product to heat the molded product from the inside to a heat treatment temperature that is at least 10 ° C higher than the base temperature, move the rod heater outside the molded product to stop the internal heating and It is also possible to use a method in which it is cooled to near the base temperature and then released from the mold.

 FIG. 4 shows the blow molding apparatus of the present invention.

In the figure, 10 is a lip capacity, 11 and 12 are blow heat treatment types, 13 is a drawing rod, 14 is a drawing rod tip, 15 is a blow block, 16 is a blow mandrel, 17 is a drawing rod slide sleeve, and 18 is a slide with airtight. Sleeve, 19 is a stretch rod cover sleeve, 20 is a spiral heater, 21 is a holding plate, 22 is a temperature sensor for controlling the temperature of the blow mass drel, 23 is a temperature sensor for measuring high pressure air, 24 is a high pressure air pipe joint, and 25 is Spiral heater airtight joint, 26 is a solenoid valve for opening and closing high pressure air.

A spiral heater (20) is built in the inner surface of the blow mandrel (16) so as to be in contact therewith. Then, replace the spiral heater (20) with the blow mandrel (16).
It is built in so as to come into contact with the inner peripheral surface so as to radiate an excessive amount of heat to the blow mandrel (16) and prevent overheating of the heater.

Further, the blow block (15) is provided with a cooling water passage (80) so as to be cooled as required.

As the spiral heater (20), a SUS316 sheath heater 1.6 mmφ 4000 W, 200 V, 3200 mm may be wound in a spiral or a 2.4 mmφ, 700 W, 200 V, 4200 mm may be wound in a spiral.

The stretch rod cover sleeve (19) may be made of SUS316. This stretch rod cover sleeve (1
9) separates the driven stretching rod (13) to keep the blow air clean and stabilize the flow of the blow air.

As the stretch rod slide sleeves (17) and (18), heat resistant engineering plastics such as polyamide imide (Toray, T1-5000, 1000), polyimide (DuPo
nt, Vesple), aromatic polyester (Sumitomo Chemical's, Econole S300, S1000), PEEK, etc. can be applied. In particular, those made of Econol have PTFE in the resin and are excellent in wear resistance and slidability. It is not desirable to construct the stretching rod slide sleeves (17) (18) with a metal such as brass because of problems such as shavings.

The blow mandrel has a split structure as shown in FIG. 5 in order to make it airtight at high pressure and to easily incorporate and take out the spiral heater. In the figure, 81 is a four-way hole connected to the high pressure air pipe joint, 82 is a heater connection hole,
83 indicates an O-ring.

 FIG. 6 shows a fixing device for the lead wire of the heater.

Sleeve (27) with steps for fixing from the outside
The lead wire (28) is treated with and is fixed to the spiral heater airtight joint (25) with an O-ring (29).

 FIG. 7 shows a flow chart of blow air.

In the figure, 38 is an exhaust air valve, 30 is an accumulator, 31 is a cooler dryer, 32 is a compressor,
24, 33, 34, 35 are air inlet pipes, 36, 37 are air vent pipes, 39
Indicates a silencer.

The blow air is pressurized by the compressor (32), cooled and dehumidified by the cooler dryer (31), and stored in the accumulator (30).

The electromagnetic valve (26) is opened once for each cycle of stretch blow, and is closed after the stretch blow and before the deaeration valve (38) is opened.

Blow heat treatment type 1
After 1 and 12 are closed, open at the same time as the lowering of the stretching rod 13 or through the delay timer after the stretching rod is descending for a suitable time, and after the blow heat treatment time set by the timer, a sequence of fixed time intervals Controlled.

The blow air temperature is below room temperature in the accumulator (30) and the air inflow pipe (24) between the accumulator (30) and the electromagnetic valve (26), and the air inflow between the electromagnetic valve (26) and the blow block (15). When passing through the pipe (24) and blow block (15), the accumulator (3
0), and the temperature in the air inflow pipe (24) is lower than the temperature in the air inflow pipe (24), and is heated in the process of passing through the blowman drel (15).

The air condition before actuation (before opening) of the solenoid valve (26) is high pressure and low temperature (room temperature) in the accumulator (30) and the air inlet pipe (33) between the accumulator (30) and the solenoid valve (25). Yes, air inflow pipe (24) between electromagnetic valve (26) and blow block (15), blow block (1
5) and the air in the blow mandrel (16) at atmospheric pressure, the air remaining in the blow mandrel (16) is at a high temperature, and the air inflow pipe (24) and blow block (15) connected to the blow block (15). The air remaining in () is maintained at a low temperature by the cooling water flowing in the blow block (15).

When the electromagnetic valve (26) is operated (opened), the high-pressure air cooled to room temperature or lower is supplied to the air inflow pipe (24), and the pressure is reduced while the blow block (15) and the blow mandrel (16). After that, it is made to flow into the parison (3).

The pressure of the air in the region from the air inflow pipe (24) to the parison (3) rises with an increase in the air inflow amount, the parison is expanded, and the accumulator is reached when the cavity reaches the mold surface. It is the same as the pressure in (30).

[Work]

 First, the operation of the manufacturing method of the present invention will be described.

In the stretch-blowing process, whitening is prevented by keeping the heat-resistant resin layer at the proper stretching temperature with heat and pressure blow air, and at the same time, the side in contact with the mold is kept at a low temperature to prevent uneven thickness. To be done.

 Next, the operation of the blow molding apparatus of the present invention will be described.

The spiral heater (20) in the blow mandrel (16) heats the air after adiabatic expansion and cooling. The spiral heater is present along the flow path of the blow air for an appropriate distance and heats the blow air in a stack.

Further, the temperature sensor for controlling the temperature of the blow mandrel and the temperature sensor for measuring the temperature of the high pressure air detect the temperatures of the blow mandrel and the high pressure air.

At the end of the blow molding process, the air inside the parison and the blow mandrel reaches high pressure, and at the same time the temperature rises due to the adiabatic compression effect, and the cooling due to the passage of air stops, so that the heater does not overheat and the electromagnetic In order to keep the temperature inside the blow mandrel constant before opening the valve (26), the temperature sensor for controlling the temperature of the blow mandrel and the temperature sensor for measuring high pressure air measure the temperature, and the heater is used based on the measured data. And the cooling of the blow mandrel as required.

[Example] Polyethylene terephthalate (Mitsui PET, Grade J
125, IV value 0.8) and U polymer (Unitika, grade)
U8400), polyethylene terephthalate 90%,
A multilayer parison with a weight ratio of 10% U polymer was injection molded. The thickness of each PET / U polymer / PETB layer in the center of the parison body is 2.9 mm / 0.24 mm / 0.88 mm from the outside of the parison, and the total thickness is
It was 4.1 mm.

In the parison injection molding and cooling process, the parison outer mold (cavity mold) is cooled with 8 ° C cooling water, while the parison inner mold (core mold) is cooled with 15 ° C cooling water with a temperature difference. The inner temperature was set to be higher than the outer temperature.

22 seconds from 19.3 seconds to the total time of injection time (refers to injection and pressure-holding time) and cooling time (refers to the time to keep the parison in the mold as it is after completion of injection and to cool it). The temperature of the parison was changed by changing the cooling conditions of the parison in the injection mold.

Also, through the temperature control process for temporarily adjusting the temperature of the parison before the molding, cooling trace, and stretch-blowing process of the parison,
This condition setting is fixed, and it is set in a cylindrical pot at a temperature of 95 ° C.
I decided to stay for 20 seconds.

Stretch-blow molding uses a spiral sheath heater (SUS316 sheath heater 1.6 mmφ, 4 mm
(00W, 200V) was used to blow heated and pressurized blow air using a blow air heating blow device. Measure the temperature with a thermocouple embedded outside the Bromandrel, change the voltage applied to the sheath heater, and change the amount of heat generated.
The temperature of the high-pressure blown air to be blown was changed.

First, when the injection cooling time was as short as 19.3 seconds, 19.5 seconds, and 20.0 seconds, stretch blow molding could be performed without using hot blow air and without causing whitening of the U polymer by cold blow air. However, at 19.3 seconds, since the parison was still left in a high temperature state, the crystallization of polyethylene terephthalate began, clouding of the bottle occurred, and the one with large wall thickness uneven thickness with poor transparency was obtained. It was

Next, the injection cooling time was extended and set to 20.5 seconds, and stretch blow molding was carried out in the same manner as above. As a result, whitening of the U polymer occurred.

Next, the sheath heater was energized and the voltage was gradually increased. At the same time, the temperature of the Bromandrel was measured. Then, stretch blow molding was performed using blow air heated by a sheath heater at various temperatures, and the heating temperature by the sheath heater was raised to a high temperature until whitening did not occur.

Whitening did not occur at 55 ° C. Furthermore, when the injection cooling time was extended to 21.0 seconds, 21.5 seconds, and 22.0 seconds by the same change of conditions, the whitening disappeared at 76 ° C, 86 ° C, and 103 ° C, respectively.

 The above experimental results are shown in FIG.

Here, the degree of occurrence of whitening was evaluated on a three-stage scale. # Indicates whitening on the entire surface of the bottle body and whitening indicates × partial whitening occurs in a considerable area, △ indicates slight occurrence of streaks or dots. It shows visible whitening. Further, ◯ indicates that no whitening occurred.

〔The invention's effect〕

(1) When a multi-layer container made of polyethylene terephthalate and a heat resistant resin is stretch blow-molded, in order to prevent whitening, conventionally, the temperature of the parison is adjusted to be close to the appropriate stretching temperature of the heat resistant resin such as U polymer. Polyethylene terephthalate was heated to a temperature higher than an appropriate temperature, and clouding easily occurred due to crystallization of polyethylene terephthalate. Especially when the injection cooling time is in the range of 19 seconds, fogging tends to occur. According to the present invention, since the injection cooling of the parison can be performed for 20 seconds or more, it is possible to eliminate the haze of polyethylene terephthalate and obtain a bottle having excellent transparency.

(2) According to the present invention, since the multi-layer container can be stretch blow-molded while preventing whitening and distortion of U polymer, grade U8450 (45% polyarylate) containing a large amount of polyarylate having high heat resistance is used as the heat resistant resin. It is possible to obtain a multilayer container having excellent heat resistance.

(3) According to the present invention, it is possible to approach the suitable stretching temperature of polyethylene terephthalate, so that it is possible to reduce the occurrence of uneven thickness of polyethylene terephthalate. Therefore, it is not necessary to use an expensive PET resin having a high IV value, and the cost can be reduced.

(4) When a large number of parisons are taken, the parison cannot be molded under uniform injection conditions, and therefore the quality and temperature control state of the parison to be stretch-blown are not uniform, so that the conventional technique can prevent the occurrence of whitening. Although not, originally, the difference in stretch blow suitability due to the difference in parison temperature between the cavities can be easily eliminated by individually controlling the hot blow air temperatures. Therefore, the parison co-injection condition and temperature control condition range can be widened.

(5) Since the spiral heater is arranged along the blow mandrel, the air can be quickly heated when high-pressure air passes through.

(6) At the end of the blowing step, the air in the bottle reaches a high pressure, and the temperature rises due to the adiabatic compression effect at the same time when the shaping by the mold is completed. On the other hand, the sheath heater continues to be heated even after the passage of blow air is stopped, and the sheath heater itself becomes high temperature and accumulates heat. By opening the electromagnetic valve at the timing when the heat storage temperature becomes the highest and performing the next blowing step, heated air can be obtained very efficiently. In addition, since the heater is placed at the position where adiabatic expansion occurs, it does not heat unnecessary equipment parts, it directly heats the blown air whose temperature has dropped, and after heating, it is immediately used for stretching and blowing. This is preferable, and the energy utilization efficiency is good.

[Brief description of drawings]

FIG. 1 is a sectional view of a parison used in the present invention, and FIG.
1 is an enlarged sectional view of the parison body shown in FIG. 1, FIG. 3 is a sectional view of a temperature control device, FIG. 4 is a sectional view of a blow molding device of the present invention, and FIG. 5 is an exploded perspective view of a blow mandrel, FIG. 6 is an explanatory view of fixing and mounting a lead wire of a heater, FIG. 7 is a flow chart of hot blow air, and FIG. 8 is a graph showing a whitening occurrence state. 3 …… Parison 1 …… Heat-resistant range layer 2 …… Polyethylene terephthalate layer 10 …… Lip cavity 11, 12, …… Blow heat treatment type 13 …… Stretching rod 14 …… Stretching rod tip 15 …… Blow block 16 …… Blow Mandrel 17 …… Stretching rod slide sleeve 18 …… Sliding sleeve with airtight 19 …… Stretching rod cover sleeve 20 …… Spiral heater 21 …… Holder plate 22 …… Blood mandrel temperature control temperature sensor 23 …… High pressure air temperature measurement Temperature sensor 24 …… High pressure air pipe fitting 25 …… Spiral heater airtight fitting 26 …… High pressure air open / close solenoid valve

Claims (2)

[Claims] 1. A heat-resistant multi-layer container comprising a heat-resistant resin layer as an intermediate layer, wherein a multi-layer parison having the heat-resistant resin layer offset to the inside of a molded article is molded, and the multi-layer parison is stretch blow molded. In the manufacturing method, the multi-layer parison is co-injection molded in a state in which the surface temperature of the male die of the parison molding injection mold is kept higher than the surface temperature of the female die, and then the inner side of the parison is higher than the outer side. A method for producing a heat-resistant multi-layer container, which comprises heat-pressurizing blow air heated during or after adiabatic expansion to blow into a parison for stretch blow molding. 2. A blow molding die, a cylindrical blow mandrel connected to the blow molding die, a blow block provided above the blow mandrel so as to enclose the mandrel upper portion, and a blow mandrel. A slide sleeve with airtight for sealing the open end and supporting the stretch rod, and a stretch rod slide sleeve for supporting the stretch rod provided near the lower part inside the blow mandrel, a slide sleeve with airtight, and a stretch rod. In a blow molding machine consisting of a stretch rod positioned at the center of the blowman drel by a slide sleeve, a spiral heater is built into the blowman drel, and a temperature sensor for controlling the blowman drel temperature and a temperature for high pressure air temperature measurement. It has a sensor, a stretch rod and Between, a tubular stretch rod cover sleeve is provided, the blow block and the blow mandrel are provided with a passage for penetrating them to supply high-pressure air between the blow mandrel and the stretch rod cover sleeve, A high pressure air injection pipe is connected to the blow block via a joint of the high pressure air injection pipe so as to be connected to the passage, and a device for supplying high pressure air is connected to the high pressure air injection pipe via an electromagnetic valve. Characteristic blow molding equipment