JP2000016484A - Plastic container receiving carbonic acid ingredient and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve preservability of solution and also discharge the solution without air substitution by forming an internal wall face of a plastic container for receiving solution containing carbonic acid ingredients of an alkali-proof resin and preparing the solution to be received to have a specific pH value and a total carbonic acid ingredient concentration within a specific range. SOLUTION: The plastic container for receiving solution containing carbonic acid ingredients for food or medical use has its internal wall face formed of an alkali-proof resin, preferably a polyolefin based resin. The solution to be received in this container is prepared so that pH is 7.79 or higher and its total carbonic acid ingredient concentration is in a range of 0.1 to 5.00 mol/L. The solution is prepared under regulations that when the total carbonic acid ingredient concentration [C] and pH of the solution (index of hydrogen ion concentration [H+]) satisfy log[C]<=log(3.83×10-4.K1/[H+] when 7.79<=pH<8.95 and log[C]<=log(3.83×10-4.K1/[H+]+log(1+K2/[H+]) when 8.95<=pH<10.22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic container containing a solution containing a carbonic acid component and a method for producing the same. More specifically, the present invention relates to a method for stably storing a carbonic acid component in a plastic container for a long period of time. The present invention relates to a container and a method for manufacturing the same.

[0002]

2. Description of the Related Art When a solution containing a carbonic acid component is contained in a container for food or medical use, the container is generally a can or a glass bottle. No transparent flexible or flexible container is used for these. This is because when the carbon dioxide gas is generated in the container, the flexible container easily expands and deforms, and the carbon dioxide gas easily permeates from the container wall in the ordinary resin container. Conventionally,
A resin container containing a carbonic acid component solution has been proposed. Such a resin container has a container wall formed of multiple layers of different resins, and an intermediate layer provided with a gas barrier layer such as an aluminum foil layer, a polyvinylidene chloride layer, and an ethylene-vinyl acetate alcohol layer. With this layer, the container wall can maintain carbon dioxide gas permeability at least to 0.1 ml / day · m ² · atm (temperature: 25 ° C.) or less. In such a resin container, carbon dioxide is present in the container in a pressurized state,
This is a so-called carbonated soft drink container.

[0003] However, in such a container, the carbonic acid component solution is stored in a pressurized state in the container, the flexibility or flexibility of the container wall is lost, and after opening, a part of the carbonic acid component comes out immediately. Would. For this reason, the exact amount of the carbonic acid component is not kept strictly before use, which is inconvenient in applying medical containers and the like. In particular, for medical containers and other specialty food containers, it is not desirable for the shelf life of the container to fluctuate by more than 10% when the shelf period is at least three years in use. Therefore, it is not preferable that carbon dioxide gas pressure is generated in the container.

Recently, resin containers have been used as medical containers. Various general-purpose thermoplastic resins are used for the resin container. Among them, polyolefin resins are frequently used because they do not adversely affect the contents of the container. It is also known that polyolefin resins are resistant to alkalinity and acidity. These resin containers usually have a wall thickness of 100 μm or more.
2000 μm is used as a limit. However,
When a solution containing a carbonic acid component is simply used as an internal solution in such a resin container, the carbon dioxide gas permeability of the resin wall is 100 ml.
/ Day · m ² · atm (temperature: 25 ° C.), so that during storage, the carbonic acid component in the solution permeates the resin wall as a gas and is lost. For example, if the carbon dioxide gas permeability of a resin container having a surface area of 1 m ² is 100 ml / day · m ² · atm (temperature: 25 ° C.) and the carbon dioxide gas pressure generated by the carbon dioxide component in the resin container is 10 mmHg, Daily loss "W"
(10/760) · 100 = 1.32 ml. Approximately three years is 1,100 days, so during the three-year storage period, 14
This results in a loss of 50 ml of carbon dioxide. This is 65 mmol in terms of the molar amount of carbon dioxide gas.

[0005] In a medical container, a flat bag is mainly used, and a normal surface area of a 1-liter bag is 0.1 m ^2.
It is. The concentration of the carbonic acid component solution is usually 20 mmol / L.
These are used at a storage concentration of 30 mmol / L or more, preferably 30 mmol / L or more. If the pressure of carbon dioxide in the medical container is 10 mmHg, after 3 years 6.5 mmol of the carbonic acid component will be lost. This results in a loss of more than 10% of the carbonic acid component in the solution of the above concentration during the storage period. In order to reduce the amount of carbon dioxide gas loss to 2 mmol or less, the pressure of carbon dioxide gas in the container must be 3 mmHg or less. In the future, even if a resin container having a low carbon dioxide gas permeability comes out, it is not preferable for medical use to generate a carbon dioxide gas partial pressure exceeding the above range.
Moreover, the carbon dioxide permeability of the container wall is 2000 ml / day · m.
^In the case of about 2.atm (temperature: 25 ° C.), the following problem occurs. This is the case where the solution in the container is alkaline and the carbon dioxide gas pressure in the container may be almost zero. That is, the concentration of carbon dioxide in the atmosphere outside the container is 0.0
3%, which is 0.2% when converted to carbon dioxide partial pressure.
It becomes 28 mmHg. For this reason, carbon dioxide gas is absorbed into the container from the outside, and the balance of the concentration of the carbon dioxide component is changed. For example, in the case of the above-described container (having a surface area of 0.1 m ² ), there is a disadvantage that about 3 mmol of a carbonic acid component is absorbed in the container in three years. Therefore, according to the present invention, the container wall is flexible, the solution in the container can be discharged without air replacement, and the inside of the container having a certain degree of irregularity does not become pressurized, and the carbonate component is stable for at least three years. It is an object of the present invention to provide a plastic container containing a carbonated component solution so as to be maintained at a low temperature and a method for producing the same.

[0006]

According to the present invention, there is provided a plastic container containing a solution containing a carbonic acid component, wherein the inner wall surface of the container wall is formed of an alkali-resistant resin, and the carbonic acid component solution has a pH of 7.79. As described above, the total carbonic acid component concentration [C] is in the range of 0.01 to 5.00 mol / L, and the total carbonic acid component concentration [C] and the PH of the solution (hydrogen ion concentration)
When [H +] index is 7.79 ≦ PH <8.95, log [C] ≦
Log (3.83 × 10 ^-4 · K1 / [H +]), and 8.95 ≦ PH
When ≤ 10.22, log [C] ≤ log (3.83 x 10 ^-4 · K1 /
[H +]) + log (1 + K2 / [H +]) It is intended to provide a plastic container containing a carbonated component solution, characterized by having a regulation of (1 + K2 / [H +]). Where [H +] is the hydrogen ion concentration in the solution in mol / L, and K1 is the first dissociation constant of carbonic acid: 4.3 × 10
^-7 , K2 is the second dissociation constant of carbonic acid: 5.6 × 10 ⁻¹¹ .

[0007] The present invention is a plastic container containing a solution containing a carbonic acid component and a method for producing the same. The carbonic acid component solution is prepared by dissolving carbonic acid, bicarbonate or carbonate in an aqueous solution or the like. Specifically, it is a solution in which sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, potassium carbonate, or the like is dissolved. In a plastic container, the inner layer of the container wall is formed of an alkali-resistant resin layer. The container may be a hard bottle or a soft bag, but in the case of a medical container, the container wall particularly needs to be transparent and flexible. As long as the flexible wall bends, the volume in the container can be easily changed and the internal solution can be discharged without air replacement. Further, the wall of the medical container has transparency to the extent that the contents can be confirmed.
This is because it may be necessary to confirm the state of the components in the container. The container is formed from a tube, sheet, or film such as an inflation film, injection molded, or blow molded. The resin material of the container is a general-purpose resin such as polyolefin resin, vinyl chloride, vinylidene chloride resin, polyester resin, polyvinyl alcohol resin, polyacrylonitrile resin, polyacrylic resin, polyamide resin, and the like.
The container wall may be formed in a single layer or a multilayer. However, the innermost layer that comes into contact with the components in the container is preferably an adhesive layer that can be heat-sealed, and is preferably a resin layer that does not affect the contents and does not generate elutes. As such a resin, a polyolefin-based resin is desirable, and examples thereof include low-, middle-, and high-density lower-grade olefin resins such as polyethylene and polypropylene.

[0008] The inner wall layer of the container wall is made of an alkali-resistant resin layer. If the alkali-resistant resin layer is an inner layer, the solution containing a carbonic acid component can be made strongly alkaline, and the release of carbon dioxide gas from the carbonic acid component can be suppressed. Never be.
Examples of such an alkali-resistant resin include neoprene resin, nylon 66, polyethylene, polyfluoroethylene, polymethyl methacrylate, polystyrene, polypropylene, polyvinyl chloride, and trans polyisoprene. In particular, as the flexible container or the alkali-resistant resin, the above-mentioned polyolefin-based resins, their copolymers, and their mixed resins are used.

The above-mentioned carbonic acid component solution has a total carbonic acid component concentration.
[C] is in the range of 0.01 to 5.00 mol / L. In the case of a medical container, the range is preferably 0.02 mol / L or more. The total carbonic acid component concentration [C] mol / L refers to the carbonic acid concentration “H ₂
CO ₃ ”(including dissolved carbon dioxide gas [CO ₂ ]), bicarbonate ion concentration [HCO ₃ ⁻ ], and carbonate ion concentration [CO ₃ ²⁻ ] in a molar amount per liter.
The specific initial total carbonic acid concentration [C] can be determined by accurately weighing and adding a carbonate such as sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, bicarbonate, etc. to the solution. it can. A carbonate solution having a concentration lower than the above range can hardly be used for food or medical use, and a carbonate solution having a concentration higher than the above range is difficult to use for food or medical use.

[0010] The total carbonic acid component concentration [C] and the hydrogen ion concentration [H +] of the solution are determined as follows: PH of the solution is 7.79 ≦ PH <
8.95 hours log [C] ≦ Log (3.83 × 10 ⁻⁴ · K1 /
[H +]) and log if 8.95 ≦ PH <11.5
[C] ≦ log (3.83 × 10 ⁻⁴ · K1 / [H +]) + log (1 + K
2 / [H +]), and when 11.5 ≦ PH, log [C] ≦ log
(3.83 × 10 ⁻⁴ · K1 · K2 / [H +] ² ). The concentration of the carbonate component contained in the container according to the present invention is regulated by the hydrogen ion concentration of the solution. This is because the partial pressure of carbon dioxide in the container increases with an increase in the concentration of carbon dioxide and a decrease in PH, and it is necessary to reduce the partial pressure of carbon dioxide. In order to reduce the partial pressure of carbon dioxide in the container to 10 mmHg or less, the above regulation is applied.

[0011] In the solution containing the carbonic acid component,
Total carbonic acid concentration [C] and carbon dioxide partial pressure [C
O₂It is difficult to directly determine the relationship with Also,
Carbonic acid [H₂CO₃] And dissolved in the liquid
It is difficult to measure separately from the existing carbon dioxide gas. I
However, depending on the carbon dioxide in the solution and the carbon dioxide in the container,
The partial pressure of carbon dioxide [CO₂] Atm and carbonic acid in solution
[H₂CO₃] Mol / L has a certain correlation
Have been. For example, at a temperature of 25 ° C., [CO₂] 0.0
29 = [H₂CO ₃], And at a temperature of 37 degrees, [CO
₂] · 0.023 = [H₂CO₃]. Therefore, charcoal
The partial pressure of carbon dioxide in the container containing the acid component solution was 25 ° C.
At room temperature [CO₂] (Atm) = Carbonic acid [H₂CO₃] (Mol /
L) /0.029=34 [H₂CO₃]. On the other hand,
Carbonic acid concentration in liquid [H₂CO₃] Is the concentration of carbonic acid component of the contained solution
It can be expressed in degrees [C] and hydrogen ion concentration.

In the container and the manufacturing method according to the present invention,
The carbon dioxide partial pressure [CO ₂ ] in such a container is 1.32 × 1
0 ^-2 atm or less, particularly, 1.32 × ^{10 -3} atm or less, i.e., 10.0 mmHg or less, it is desirable that especially 1.0mmHg less. If it is less than this range, air intrusion for maintaining the equilibrium between the carbon dioxide partial pressure inside the container and the carbon dioxide partial pressure outside the container is small, and the expansion of the container is suppressed. Furthermore, loss of the carbon dioxide component during the shelf period and three years can be sufficiently suppressed.

First, the total carbonic acid component concentration [C] in the solution in the container according to the present invention and the carbonic acid concentration [H ₂ CO ₃ ] are closely related to the hydrogen ion concentration [H +]. For example, the total carbonic acid component concentration [C] is [C] = [H ₂ CO ₃ ] + [HCO ₃ ⁻ ] + [C
O ₃ ^2- ], and the concentration of carbonic acid [H ₂ C
O ₃ ], bicarbonate ion concentration [HCO ₃ ⁻ ], and carbonate ion concentration [CO ₃ ²⁻ ] are related by the first dissociation constant K 1 and the second dissociation constant K ² of carbonic acid. K1 = [H +] ・ [HC
O ₃ ⁻ ] / [H ₂ CO ₃ ] and K 2 = [H +] · [CO ₃
^2- ] / [HCO ₃ ⁻ ].

Here, [H ₂ CO ₃ ] / [HCO ₃ ⁻ ]
The PH of the carbonate solution at a ratio of = 20 is 5.07 from the first dissociation constant. That is, K1 = [H +] · (1 /
20), the PH can be obtained. here,
If [H ₂ CO ₃ ]> 20 [HCO ₃ ⁻ ], only [H ₂ CO ₃ ] is mainly present in the carbonate solution, and the total carbonate concentration [C] is [C] = [H ₂ CO ₃ ] + [HCO ₃ ⁻ ] +
[CO ₃ ^2- ] ≒ [H ₂ CO ₃ ], and the carbonic acid concentration [H ₂ C
[HCO ₃ ⁻ ] having a value less than 1/20 of [O ₃ ] can be ignored by truncation. Therefore, if the PH is less than 5.07, [H ₂ CO ₃ ] = [C]...

Next, the carbonic acid concentration [H₂CO₃] And bicarbonate
ON concentration [HCO₃ ⁻] And [H₂CO₃] / [HCO
₃ ⁻] = PH of the carbonic acid solution at a ratio of 1/20
From one dissociation constant, PH = 7.66. That is, K1 = [H
+] · 20. Here, 5.07 ≦
If PH <7.66, mainly in the above carbonate solution,
[H₂CO₃] And [HCO₃ ⁻] And the presence of total carbonate
The partial concentration [C] is [C] = [H₂CO₃] + [HCO₃ ⁻] +
[CO₃ ^2-] ≒ [H₂CO₃] + [HCO₃ ⁻]so,
Bicarbonate ion concentration [HCO₃ ⁻] Is less than 1/20 of
[H₂CO₃] Cannot be ignored. Because of this,
Within the PH range, K1 = [H +] · ([C]
− [H₂CO₃] / [H₂CO₃] And organize
And [H₂CO₃] = [C] ・ [H +] / (K1 + [H +]) ・ ・ ・ Formula
It becomes 2. Next, the bicarbonate ion concentration [HCO₃ ⁻] And charcoal
Acid ion concentration [CO₃ ^2-] And [HCO₃ ⁻] / [C
O₃ ^2-] = 20, the PH of the carbonate solution is
Due to two dissociation constants, PH = 8.95. That is, K2 =
[H +] · (1/20). here,
If 7.66 ≦ PH <8.95, the above carbonic acid component solution
Some [HCO₃ ⁻] Is present and the total carbonic acid concentration
[C] is [C] = [H₂CO₃] + [HCO₃ ⁻] + [CO₃
^2-] ≒ [HCO₃ ⁻], The bicarbonate ion concentration [HCO
₃ ⁻] [H] of a value not exceeding 1/20₂CO₃]as well as
[CO₃ ^2-] Can be truncated. Because of this,
In the carbonate solution within the pH range, from the first dissociation constant,
K1 = [H +] ・ [HCO₃ ⁻] / [H₂CO₃] And [H₂
CO₃] = [H +] · [C] / K1 Equation 3 is obtained.

Next, the bicarbonate ion concentration [HCO₃ ⁻]When
Carbonate ion concentration [CO₃ ^2-] And [HCO₃ ⁻] /
[CO₃ ^2-] = 1/20 of the above carbonic acid component solution
H is the second dissociation constant, PH = 11.5. Immediately
That is, it can be obtained from K2 = [H +] · 20. here,
If 8.95 ≦ PH <11.5, the above carbonic acid component solution
Some [HCO₃ ⁻] And [CO₃ ^2-] Exists
And the total carbonic acid concentration [C] is [C] = [H₂CO₃] + [HC
O₃ ⁻] + [CO₃ ^2-] ≒ [HCO₃ ⁻] + [CO₃
^2-], The carbonate ion concentration [CO₃ ^2-] 1/20 or more
Do not fall below [HCO₃ ⁻] Cannot be ignored. this
Therefore, within the above-mentioned PH range, the first and second dissociation constants
[H ₂CO₃] = [H +] ・ [C] / K1 (1 + K2 / [H +])
It becomes 4. Next, PH in the carbonate solution is 11.5 ≦ P
If it is H, the carbonic acid component solution mainly contains [C
O₃ ^2-], And the total carbonic acid component concentration [C] is [C] = [H₂
CO₃] + [HCO₃ ⁻] + [CO₃ ^2-] ≒ [CO₃
^2-], The carbonate ion concentration [CO₃ ^2-1/20 of]
The value of [HCO₃ ⁻] Can be truncated
You. For this reason, within the above PH range, the first and second dissociation
[H₂CO₃] = [H +] ²・ [C] / K1 ・ K2 ・ ・ Formula 5
Becomes

From the above formulas 1 to 5, carbonic acid [H
₂CO₃] And the total carbonic acid component [C] are required. Figure
1 indicates that the total carbonic acid component concentration [C] in the carbonic acid component solution is 0.0
PH value and log [H at 1 mol / L and 5 mol / L₂C
O₃Is illustrated. Where
As described above, the carbon dioxide partial pressure [CO₂] Is 1.32
× 10 ^-2It must be less than atm (10 mmHg).
In particular, 1.32 × 10^-3atm (1mmHg) or less
Is desirable. That is, at room temperature, the carbonic acid in the solution is [H
₂CO₃] = 1.32 × 10^{ー 2}(atm) × 0.029 =
3.83 × 10^-4mol / L or less, especially 3.83 × 10
^-5Desirably, it is mol / L or less.

As shown in FIG. 1, when the carbonic acid concentration [H ₂ CO ₃ ] is 3.83 × 10 ⁻⁴ mol / L or less, the pH value of the carbonic acid component solution is 0.01 to 0.01%. It is regulated in the range of 7.79 to 10.22 in the range of 5.0 mol / L. When the carbonic acid concentration [H ₂ CO ₃ ] is 3.83 × 10 ⁻⁵ mol / L or less, the PH value of the carbonic acid component solution is determined by the concentration [C]
Is 8.79 to 10.8 in the range of 0.01 to 5.0 mol / L.
Limited to 4

FIG. 2 shows that the concentration of carbon dioxide [H ₂ CO ₃ ] (or the partial pressure of carbon dioxide in the container [P] mmHg) is kept constant, ie, [H
₂ CO ₃ ] = 3.83 × 10 ⁻⁴ mol / L (10 mmHg),
And [H ₂ CO ₃ ] = 3.83 × 10 ⁻⁵ mol / L (1 mm
FIG. 9 is a diagram showing a limiting relationship of a total carbonic acid component concentration [C] to a change in PH at Hg). PH of the above carbonate solution
When 7.79 ≦ PH <8.95, lo
g [C] ≦ Log (3.83 × 10 ⁻⁴ · K1 / [H +])
When 8.95 ≦ PH ≦ 11.5, log
[C] ≦ log (3.83 × 10 ⁻⁴ · K1 / [H +]) + log (1+
K2 / [H +]). Therefore, FIG.
The shaded area shown in Fig. 7 shows the relationship between the total carbonic acid component concentration [C] where the carbonic acid component solution according to the present invention exists and the PH value. However, the total carbonic acid component concentration [C] mol / L is 5.0 mol / L
Since it is below, it is meaningless to indicate a regulation of a higher concentration. Therefore, the PH value of the carbonic acid component solution in the container is 7.79 to 10.22 according to the total carbonic acid component concentration [C].
Subject to regulations. Therefore, the relationship between the above equations 1 and 5 becomes irrelevant. The shaded area shown in FIG. 2 indicates the concentration of carbonic acid [C] in which the carbonic acid solution according to the present invention exists when the carbon dioxide partial pressure [CO ² ] (mmHg) in the container is 1 mmHg or less. It shows a more preferable relationship with the PH value.

In the plastic container containing a carbonate solution according to the present invention, the contained solution may contain any of the above total carbonate concentrations.
In [C], it can be seen that the PH value is limited within the regulation range. In this case, since the concentration of carbon dioxide in the solution, that is, the partial pressure of carbon dioxide in the solution is maintained within a certain range (10 mmHg or 1 mmHg), the flexible container wall does not expand during storage. Also, the inside of the container is not pressurized as in the prior art, and the container wall maintains flexibility. Further, it is not necessary to use a container having an opaque non-gas permeable wall using an aluminum foil as in the related art. Then, when the carbonic acid component solution is taken out from the outlet or the like during use, the carbonic acid gas does not blow out, and the carbonic acid component concentration of the carbonic acid component solution is kept constant. In addition, since no pressure is generated during storage, the flexibility of the container wall is sufficiently maintained during storage.

A plastic container containing a carbonate component solution according to claim 3 of the present invention is the plastic container according to claim 1 or 2, wherein the total carbonate component concentration [C] of the solution is
Is regulated by the PH in the above concentration range, and the carbon dioxide gas permeability [V] of the container wall is 0 to 100000 (ml / m ² a
tm), and when the permeability [V] is 16.3 (ml / m ² atm) or more, the pH of the solution is 7.79 ≦ PH <8.9.
At the time of 5, [V] ≦ 2.6 × 10 ⁻⁷ / [H +], and 8.9
When 5 ≦ PH ≦ 10.9, [V] ≦ (2.6 × 10
⁻⁷ [H +] + 1.4 × 10 ⁻¹⁷ ) / [H +] ²

Normally, the loss [W] (mol) of carbon dioxide gas lost from the inside of the container to the outside world in three years is determined by the carbon dioxide partial pressure [CO ² ] (atm) in the container and the carbon dioxide gas permeation through the container wall. Degree [V] (ml / m
² atm: temperature 25 ° C.) and the surface area [S] (m ² ) of the container wall can be expressed as follows. Loss [W] (mol) = 365
× 3 × [CO ² ] (atm) × [S] (m ² ) × [V] (ml / m ² atm) ×
(1/2224), and the amount of loss [W] (mol) = 4.9 ×
10 ⁻² × [CO ² ] [S] [V].

Normally, a flexible bag takes up a large surface area in a flat container as compared with its capacity. The volume of a 1 L container is V = 10
For example, a 1 L flat container such as × 50 × 2 cm ³ can have a container thickness of about 2 cm. Therefore, the surface area [S] (m ² ) of the container wall of the 1L container is 10 cm × 50 cm × 2 times =
0.1 m × 0.5 m × 2 ≒ 0.1 m ² may be used as a guideline. Therefore, when the surface area [S] (m ² ) = 0.1 is substituted into the above equation, the loss amount [W] (mol) = 4.9 × 10 ⁻³ × [C
O ² ] [V].

Next, the carbon dioxide partial pressure [CO ² ] (a
tm) and carbonic acid [H ² CO ³ ] (mol) in the solution in the container have a certain relationship as described above. That is, carbon dioxide partial pressure [CO ² ] (atm) = 34 · [H ² CO ³ ] (mol / L)
It is. Therefore, the loss [W] (mol) and the carbonic acid [H ²
The relationship with [CO ³ ] (mol / L) is obtained by substituting the above relationship.
Loss weight [W] (mol) = 0.17 × [V] [H 2 CO 3] a (mol).

On the other hand, carbonic acid [H ² CO ³ ] (mol / L) and hydrogen ion concentration [H +] have the following relationship. (1) Up to pH 5.07 (8.5 × 10 ⁻⁶ ) Carbonic acid [H ² CO ³ ] in solution (mol / L) = total carbonic acid component concentration in solution [C] (mol / L) (2) At PH 5.07 to 7.66 (2.2 × 10 ⁻⁸ ) Carbonic acid [H ² CO ³ ] = [C] [H +] / (K1 + [H +]) (3) PH 7.66 to 8.95 ( 1.1 × 10 ⁻⁹ ) Carbonic acid [H ² CO ³ ] = [C] [H +] / K1 (4) PH 8.95 to 11.5 (3.2 × 10 ⁻¹² ) Carbonic acid [H ² CO ³ ] = [C] [H +] / K1 (1 + K2 / [H +]) (5) When PH is 11.5 or more Carbonic acid [H ² CO ³ ] = [C] [H +] ² / K1K2

From the above results, the carbon dioxide gas permeability [V] (ml / m ² at
m) and the amount lost (W) (mol) in terms of hydrogen ion concentration [H +] and total carbonic acid component concentration [C] are as follows. (1) Up to pH 5.07, the amount of loss [W] (mol) = 0.17 x
[V] [C] (mol), and [V] = [W] /0.17× [C]. (2) Loss [W] (mol) when pH is 5.07 to 7.66
= 0.17 × [V] [C] [H +] / (K1 + [H +]), and [V] = [W]
(K1 + [H +]) / 0.17 × [C] [H +]. (3) When PH is 7.66 to 8.95, the amount of loss [W] (mol)
= 0.17 x [V] [C] [H +] / K1, [V] = [W] K1 / 0.
17 × [C] [H +]. (4) When PH is 8.95 to 11.5, loss amount [W] (mol)
= 0.17 × [V] [C] [H +] / K1 (1 + K2 / [H +]), and [V] =
[W] (K1 [H +] + K1K2) /0.17× [C] [H +] ² . (5) At PH 11.5 or higher, the loss [W] (mol) = 0.1
7 × [V] [C] [H +] ² / K1K2, [V] = [W] K1K2 / 0.1
7 × [C] [H +] ²

The amount of loss [W] (mol) is desirably 1/10 or less of the total carbonic acid component [C] (mol) in the solution during the three-year storage period. Therefore, the amount of loss [W] (mol) = (1/10) [C]
(mol), (1) Up to pH 5.07, [V] ≦ (1 /
10) [C] /0.17 [C] = 0.59. (2) When the pH is 5.07 to 7.66, [V] ≦ (1/10) [C]
(K1 + [H +]) / 0.17 [C] [H +] = (K1 + [H +]) / 1.7 [H +]
= 0.59 + 2.6 × 10 ⁻⁷ / [H +]. (3) When the pH is 7.66 to 8.95, [V] ≦ (1/10) [C] K1
/0.17[C][H+]=K1/1.7[H+]=2.6×10 ⁻⁷ / [H +]
Becomes (4) When PH is 8.95 to 11.5, [V] ≦ (1/10) [C] K1
(1 + K2 / [H +]) / 0.17 [C] [H +] = (2.6 × 10-7 [H +] + 1.4 × 10
^-17 ) / [H +] ²

(5) When the pH is 11.5 or more, [V] ≦ (1/10)
[C] K1K2 / 0.17 [C] [H +] ² = (1/10) K1K2 / 1.7 [H +] ² = 1.4
× 10 ⁻¹⁷ / [H +] ² The above relationship is shown in FIG.

When the total carbonic acid component concentration [C] (mol / L) of the solution is 0.01 to 5 mol / L, the pH of the solution according to the present invention in the container according to the present invention is 7.
There are only over 79 solutions. Also, carbon dioxide permeability
A container wall having a [V] exceeding 100,000 ml / m ² atm (temperature: 25 ° C.) does not have a sufficient mechanical strength as a resin container, and therefore does not substantially exist. Therefore, the carbon dioxide gas permeability [V] (ml / m ² atm) of the container wall according to the present invention is, as shown in FIG.
Regulated up to 0.9 and carbon dioxide gas permeability [V]
3 satisfying the shaded region in FIG. 3 at 16.3 ml / m ² atm or more, it is possible to avoid excessive loss of carbon dioxide in the solution exceeding 10%.

Next, according to a fourth aspect of the present invention, there is provided a method for manufacturing a transparent and flexible medical plastic container containing a solution containing a carbonate component, wherein the inner wall surface of the container is made of an alkali-resistant resin. The pH of the carbonic acid component solution to be accommodated is adjusted to be 8.61 or more.
The total carbonic acid component concentration [C] of the solution was adjusted to 0.02 to 5.00 mol /
L, and when the pH of the solution is 8.61 ≦ PH <8.95, the carbonic acid component concentration [C] and the hydrogen ion concentration [H +] are log [C] ≦ Log (11.5 × 10 ⁻⁵
・ K1 / [H +]) and adjust the pH of the solution to 8.95.
When ≦ PH ≦ 10.39, log [C] ≦ log (11.5 × 10
⁻⁵・ K1 / [H +]) + log (1 + K2 / [H +])
The carbon dioxide gas permeability [V] of the container wall is set to 0 to 1000.
00 ml / m ² atm and the permeability [V] is 16.3 ml / m ^2.
For atm or more, when 8.61 ≦ PH <8.95
[V] ≦ 2.6 × 10 ⁻⁷ / [H +], and 8.95 ≦ PH ≦ 10.
In the case of 9, [V] ≦ (2.6 × 10 ⁻⁷ [H +] + 1.4 × 10 ⁻¹⁷ )
/ [H +] ² by providing a method for producing a plastic container containing a carbonated component solution,
It is intended to provide a container containing a preferable resinous carbonic acid component solution.

When a carbonic acid component is contained in the medical container, the total carbonic acid component concentration [C] is 0.02 mol / L or more, and particularly, in the case of a multi-compartment container which is divided into two chambers and mixed, it is 0.1 mol / L. 03mo
It is desirable to exceed l / L. Furthermore, in order to suppress the amount of loss [W] as carbon dioxide per liter of solution to 2 mmol, it is desirable that the partial pressure of carbon dioxide [CO ² ] in the container is 3 mmHg or less. For this reason, the contained carbonic acid component solution is regulated to PH8.61 or more, so that expansion in the container and loss of carbon dioxide gas can be prevented, and the medical container is safe even after a storage period of 3 years. Can be used for

Further, in the case of a medical container, the container wall must have transparency. As a material of the medical container, the alkali-resistant resin is a polyolefin resin. Examples of the polyolefin resin having a low carbon dioxide gas permeability [V] include linear low-density polyethylene and high-density polyethylene. By using a container wall of these resins with a thickness of 500 μm or more, the carbon dioxide gas permeability [V] can be suppressed to 16.3 ml / m ² atm or less. However, when the above resin is used at such a thickness, there is a problem that the transparency of the medical container is lacking. Therefore, a transparent and flexible medical container made of a polyolefin resin usually has a permeability [V] of the container wall of 100 ml / m ² atm (temperature: 25 ° C.) or more. Therefore, by adjusting the relationship between the carbon dioxide permeability [V] of the container wall and the pH of the storage solution, the medical container can determine the amount of carbon dioxide gas loss from the container for three years by the carbon dioxide in the solution. It can be suppressed to 10% or less of the components. When the container is double-wrapped or the like, the carbon dioxide gas permeability [V] of the container wall is the sum of the carbon dioxide gas permeability [V] of the outer package and the inner package. Therefore, the permeability [V] (ml / m ² atm) of the container wall here means the substantial permeability.

According to a fifth aspect of the present invention, in the method for manufacturing a medical container according to the fourth aspect, the container is double-wrapped in a packaging bag, and the carbon dioxide gas permeability [V] of the packaging bag. Is 680 ml / m ² atm (temperature 25 ° C.) or less.

Normally, the concentration of carbon dioxide in the atmosphere is 0.03%
And its partial pressure is 3 × 10 ⁻⁴ atm, ie 2.28
× 10 ^-1 mmHg. Substituting into the above equation, the permeation amount of carbon dioxide gas permeated from the container wall in three years is (W) =
3.3 × 10 ⁻² × Permeability [V] ml Here, the carbon dioxide gas permeability [V] of the container wall is 680 ml / day · m ² ·
Substituting atm (temperature: 25 ° C.), the carbon dioxide gas penetration amount (W) becomes 22.4 ml, which is equivalent to 1 mmol.

If the pH of the carbonic acid component solution in the container is made excessively alkaline, the partial pressure of carbon dioxide in the container may approach zero, and the partial pressure of carbon dioxide in the outside world may be higher. In this case, the carbon dioxide gas permeability [V] of the container wall is 680 ml /
m ² atm (temperature: 25 ° C.) or more, especially 1000 ml / m ² atm
(Temperature: 25 ° C.) or more indicates that the amount of carbon dioxide gas entering further increases. For this reason, by covering the container with a packaging bag having a carbon dioxide gas permeability [V] of 680 ml / m ² atm (temperature: 25 ° C.) or less, the carbon dioxide gas entering from outside in the solution in the container. Can be prevented from being excessively absorbed.

According to a sixth aspect of the present invention, there is provided a method for manufacturing a container, comprising the steps of:
The above-mentioned container wall is made of a polyolefin-based resin, and a chamber which can communicate with the use of the above-mentioned container is formed by dividing into two or more chambers,
A solution containing the carbonic acid component is accommodated in at least one chamber,
The total carbonic acid component concentration [C] of the solution in the one chamber is set to 0.03 (mol /
L), the pH of the solution exceeds 8.8, and an acidic solution for lowering the PH value of the mixture when the carbonic acid component solution is mixed is housed in another chamber.

The inner wall of the container wall is made of a polyolefin resin. The polyolefin-based resin has sufficient alkali resistance and acid resistance. In addition, in the case of a medical container, the content solution is hardly affected. The medical container is divided into two or more chambers that can communicate with each other when used, and is formed into a multi-chamber container. Some medical infusions contain amino acids and sugars. However, if a mixed solution containing an amino acid and a saccharide is contained in a container, deterioration may occur during high-pressure steam sterilization or storage. For this reason, there is a transfusion container in which the inside of the container is divided into two chambers, and the amino acid solution and the sugar solution are placed in different chambers. The container according to the present invention is a container having such a plurality of chambers, in which a solution containing a carbonic acid component and an acidic solution for lowering the PH value of a mixed solution thereof are separately accommodated.

The total concentration of carbonic acid in the above solution of carbonic acid in one chamber
[C] is more than 0.03 mol / L, preferably 0.04 mol / L or more. The total concentration of carbonic acid in the solution as an infusion agent is required to be about 20 mmol / L or more. But,
This is because, during use, the components of one chamber and the other chamber are mixed, so that the carbonate solution of one chamber is substantially diluted during use. Further, in order to prevent the loss of the carbonic acid component in the container for three years, it is desirable that the partial pressure of carbon dioxide in the container is 3 mmHg. For this reason, the PH of the carbonic acid component solution in the above one chamber is set to exceed 8.8. If it is a container accommodated in this way, crawl which is a problem with infusion agents,
Acidosis due to the addition of lactic acid and acetic acid can be eliminated. Human bodily fluids naturally contain bicarbonate ions, but the container according to the present invention can provide an infusion solution containing such bicarbonate ions. In addition, it can be provided for three years after preservation and accurate maintenance of the bicarbonate concentration until use.

The chamber may be divided into two or more chambers by forming a separating wall or the like in the container, or the container may be connected to the container to form a single container and the connected container may be the chamber.
The chambers are formed so as to be able to communicate with each other. The term "communicable" means that the communication means is provided on the separating wall between the chambers, that the inner walls of the container walls are separated from each other by an adhesive seal that can be peeled off, and that the chambers are communicated with each other when used. is there. As the communication means, a pipe having one end closed is provided between the chambers, and the closed end is broken from the outside of the container during use to connect the chamber with the chamber by use, or a container overlapping from the outside. There are things that clip the wall and put it.

To lower the PH value means that a medical container is used in the vicinity of pH 6 to 8 at the time of use, so that an acidic solution is housed separately from a solution containing a carbonic acid component so as to obtain such a PH. It is. The pH value of such an acidic solution is desirably 3.5 or less, particularly desirably 3.1 or less.
When acetic acid, lactic acid, or the like, which is a weak acid, is used, an acidic solution having a pH exceeding the above range does not sufficiently exert the effect of lowering the pH of the mixed solution. Saccharides, acidic solutions, etc.
Other electrolytes and the like can be included as appropriate. Thereby, it is possible to provide an optimal infusion solution, dialysate, or the like containing a carbonate component at the time of use.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a plastic container containing a carbonate component solution and a method for producing the same according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a hydrogen ion concentration [H +] and a carbonic acid concentration [H] in a carbonic acid solution contained in a plastic container containing a carbonic acid solution according to the present invention.
² CO ³ ]. FIG. 2 shows the hydrogen ion concentration [H +] and the concentration of the carbonate component log of the carbonate solution contained in the plastic container containing the carbonate solution according to the present invention.
It is a relationship diagram with [C]. FIG. 3 is a relationship diagram of the carbon dioxide gas permeability log [V] with respect to the PH of the carbonic acid component solution contained in the plastic container containing the carbonic acid component solution according to the present invention. FIG. 4 is a plan view showing the structure of the plastic container containing the carbonate solution according to the present invention. FIG. 5 is an enlarged sectional view of the container wall shown in FIG. FIG. 6 is a plan view showing a structure of a plastic container accommodating a carbonate component solution according to a modification of FIG.

The container 1 containing a carbonate component solution according to the present embodiment is a plastic container containing a solution 2 containing a carbonate component. The carbonic acid component solution 2 is made of P
H is 7.79 or more and the total carbonic acid component concentration [C] is 0.0
1 to 5.00 mol / L, and at least the inner layer 3
A is formed from the alkali-resistant resin layer, and the total carbonic acid component concentration [C] and the hydrogen ion concentration [H +] of the solution are the same as those of the solution 2
Log [C] ≦ Log when PH of 7.79 ≦ PH ≦ 8.95
(3.83 × 10 ⁻⁴ · K1 / [H +]), and 8.95 ≦
When PH ≦ 10.22, log [C] ≦ log (3.83 × 1
⁰⁻⁴ · K1 / [H +]) + log (1 + K2 / [H +]). Where [H +] is the hydrogen ion concentration in solution 2 mol / L and K1
Is the first dissociation constant of carbonic acid and K2 is the second dissociation constant of carbonic acid.

The container 1 according to this embodiment will be described in more detail. As shown in FIG. 4, the container 1 has a cylindrical folded diameter of 130 m.
m inflation sheet is cut into a length of 600 mm, and the cut edges 4A and 4B are sealed by heat welding. The sheet that is the container wall 3 is a co-extruded inflation sheet, the inner layer 3A is a mixed resin in which linear low-density polyethylene and polypropylene are mixed at a ratio of 2: 1, and the outer layer 3B is made of linear low-density polyethylene. The inner layer 3A has a thickness of 50 μm, and the outer layer 3B has a thickness of 350 μm. The sheet is flexible and its carbon dioxide gas permeability [V] is 254 ml / day · m ² · atm
(Temperature: 25 ° C.). The surface area of the container 1 is about 0.12 m ² , and the container 1 is filled with 1 L of the carbonate solution 2 in a liquid-tight manner. The container 1 has a liquid outlet 10.
Is attached.

The carbonic acid component solution 2 in the container 1 was adjusted to the following concentration to obtain each sample.
Checked in ° C. In the experiment, the swelling in the container 1 after one month and the concentration of the carbonic acid component were measured for the carbonic acid component using phenolphthalein and methyl orange. The relationship among the carbonic acid concentration, carbonic acid concentration, PH, and transmittance of the carbonic acid component solution 2 on the setting of each sample is shown by triangular marks in FIGS. Sodium bicarbonate is accurately weighed to adjust the concentration [C] of the carbonic acid component solution 2 in the container 1 to 0.01 mol / L, and the pH is adjusted with a 0.1N sodium hydroxide solution to the pH of the carbonic acid component solution 2. Adjust the value to 9.37. Ten such samples were manufactured, and the sample name was E1.

The sodium bicarbonate is accurately weighed and the container 1
The concentration [C] of the carbonic acid component solution 2 therein is adjusted to 0.05 mol / L, and the pH is adjusted to 9.95 with a 0.1 N sodium hydroxide solution.
Ten such samples were manufactured, and the sample name was E2. Sodium bicarbonate is accurately weighed to adjust the concentration [C] of the carbonic acid component solution 2 in the container 1 to 0.1 mol / L, and the pH is adjusted with a 0.1N sodium hydroxide solution to the pH of the carbonic acid component solution 2. Adjust the value to 10.17. Ten such samples were manufactured, and the sample name was E3.
Sodium bicarbonate is accurately weighed to adjust the concentration [C] of the carbonic acid component solution 2 in the container 1 to 0.5 mol / L,
H is adjusted with a 0.1 N sodium hydroxide solution to adjust the PH value of the carbonic acid component solution 2 to 10.61. Ten such samples were manufactured, and the sample name was E4. Accurately weigh sodium bicarbonate and add carbonate solution 2
Is adjusted to 1.0 mol / L, and the pH of the carbonic acid component solution 2 is adjusted to 10.78 with a 0.1 N sodium hydroxide solution. Ten such samples were manufactured, and the sample name was E5.

The samples E1 to E5 are shown in FIGS.
As can be seen from the above, all are in the shaded area corresponding to the carbonate solution in the container according to the invention. In addition, with the lapse of time after one month, no swelling or the like was observed in any of the samples E1 to E5. In addition, as a result of examining the carbonic acid component concentration [C] one month after each, the value of each of E1 to E5 was 1%.
0 samples were within ± 3% of their initial values except for E1. The average value of the carbonic acid component concentration [C] of E1 to E5 is 0.011 mol / L for E1,
E2 is 0.049 mol / L, E3 is 0.102 mol
/ L, E4 is 0.492 mol / L, E5 is 0.991
mol / L.

Next, another embodiment of the method for manufacturing a plastic medical container according to the present invention will be described with reference to FIG. Plastic container 5 containing a carbonate solution shown in FIG.
Is made of the same material as the container 1 shown in FIGS. 4 and 5 (except that the outer layer is made of low-density polyethylene having a thickness of 350 μm and the carbon dioxide permeability [V] of the container wall is 2400 ml / m ² atm (temperature 25
° C). ). The difference between the container 5 and the container 1 is that a peel seal strip 6 that can be peeled from the outside is formed substantially at the center, and the container 5 is divided into a chamber 7A and a chamber 7B. The sealing strip 6 is formed by sealing the inner walls of the sealing strip 6 in a liquid-tight manner. The peel strength of the sealing strip 6 is peeled at a pressure in one chamber 7B of 0.01 to 0.03 kgf / cm ^2. Strength. Note that the seal portions of the cut ends 4A and 4B of the container 5 are non-peelable fixed seal portions, and are sealed under heat sealing conditions at a temperature of 170 ° C. In addition, the peel seal strip 6
Is sealed under heat sealing conditions at a temperature of 140 ° C.

The above chamber 7A is hermetically filled with a carbonate solution 8. The carbonic acid component solution 8 is produced as follows. First,
One liter of a sodium hydroxide solution was produced at a concentration of 0.1 mol / L, and 40 ml of the sodium hydroxide solution was distilled water 2
Put in 50 ml and use this as the base solution. Next, 8.40 g (0.1 mol) of sodium bicarbonate is added to the base solution. Therefore, generation of carbon dioxide gas can be suppressed as much as possible when sodium hydrogen carbonate is added. Next, P
While measuring the H value, add 10 ml of a 0.1 mol / L sodium hydroxide solution to adjust the PH value of the base solution to 10.1.
Distilled water is added to the base solution to make 1000 ml, and 300 ml of the solution is taken to obtain a carbonic acid component solution 8.
Measure the value to obtain an alkaline solution of PH 9.98.

The chamber 7B contains an acidic electrolyte solution 9. The electrolyte solution 9 is a component such as an infusion solution containing sugar and the like. Glucose is mainly used as the saccharide, but in addition to glucose, fructose, xylitolose, sorbitol and the like are also used. The electrolyte solution 9 appropriately contains an electrolyte in addition to the saccharide, and examples of the electrolyte include sodium, potassium, chlor, calcium, and magnesium. If necessary, trace metals such as zinc, phosphorus, iron, and copper, and organic acids such as citric acid, gluconic acid, acetic acid (acetates), and lactic acid (lactate) are also added. These electrolytes and organic acids are used as hydrochloride, lactate, acetate, sulfate, phosphate, gluconate, and glycerophosphate.

The electrolyte solution 9 is accommodated in the chamber 7B in an amount of 700 ml, and the sodium in the solution is 0 to 320, particularly 40 to 320.
A concentration of 160 mmol is used for the electrolyte solution 9. However, the required amount is the amount obtained by subtracting the sodium salt used in sodium hydrogen carbonate and sodium hydroxide of the carbonic acid component solution 8. Potassium is 0-160, especially 2
Used in concentrations ranging from 0 to 140 mmol. Chlor is used in the electrolyte solution 9 in a concentration ranging from 0 to 320, in particular from 40 to 160 mmol. Calcium is used in the electrolyte solution 9 in a concentration ranging from 0 to 40, especially 8 to 30 mmol. Magnesium is 0-50, especially 12-40mmo
Used at concentrations in the range of l. Other substances such as phosphoric acid and zinc are appropriately added. In this example, lactic acid was 7 mmo
1 is added, and the electrolyte solution 9 has a PH value of PH3.10. The carbonic acid component solution 8 and the electrolyte solution 9 have a temperature of 110
A high-pressure steam sterilization process at ℃ is performed.

In the plastic container 5 containing the carbonic acid component solution of the present embodiment thus constructed, the amount of the carbonic acid component in the total carbonic acid solution 8 after one month at room temperature is 100 mmol.
/ L is a decrease of 2% or less with respect to the initial value. The PH value of the mixed solution when the chamber 7B is pressed from the outside to peel off and open the sealing strip 6 is 7.22. And
The bicarbonate ion concentration is 23.1 mE due to the influence of lactic acid and the like.
q / L. The container 5 is hermetically sealed in a packaging bag, and after leaving it in an environment at a temperature of 40 ° C. for 6 months, the amount of carbonic acid in the carbonated solution 8 is examined. The packaging bag is formed by evaporating silica on stretched polypropylene and having a carbon dioxide gas permeability [V] of the packaging wall of 10 ml / m ² atm (temperature 25 ° C.) or less. As a result, the pH of the solution after mixing in the ten packaging sample containers is 7.2 ± 0.1.

Therefore, the plastic container 5 containing the carbonate solution according to the present embodiment can provide an infusion solution having an appropriate carbonate component to the human body, and can be expected to be stable for a long shelf period. In the above embodiment, the infusion solution is stored in the container 5, but a dialysate, a washing solution, a food solution, or the like can be stored. In the above embodiment, the resin sheet was molded, but in the present invention, a known molded article such as a blow molded article or an injection molded article can be appropriately used.

[0053]

As described above, the present invention relates to a plastic container containing a solution containing a carbonic acid component, wherein the inner wall surface of the container is formed of an alkali-resistant resin, and the pH of the carbonic acid component solution is 7.79. As described above, the total carbonic acid component concentration [C] is in the range of 0.01 to 5.00 mol / L, and the total carbonic acid component concentration [C] and the PH (hydrogen ion concentration [H +] index) of the solution are 7.79 ≦ PH <8.95 when log [C] ≦
Log (3.83 × 10 ^-4 · K1 / [H +]), and 8.95 ≦ PH
When ≤ 10.22, log [C] ≤ log (3.83 x 10 ^-4 · K1 /
[H +]) + log (1 + K2 / [H +])
The inside of the container is not pressurized, the container wall is flexible, the solution in the container can be discharged without air replacement, and has a certain degree of atypicality, and the carbonic acid component is stably maintained for at least three years. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a hydrogen ion concentration [H +] and a carbonic acid concentration log [H ² CO ³ ] in a carbonic acid solution contained in a plastic container containing a carbonic acid solution according to the present invention. It is.

FIG. 2 is a graph showing a relationship between a hydrogen ion concentration [H +] and a carbonic acid component concentration log [C] of a carbonic acid solution contained in a plastic container containing a carbonic acid solution according to the present invention.

FIG. 3 is a graph showing the relationship between the concentration of carbonic acid component log [C] and the permeability of carbon dioxide gas log [V] contained in a plastic container containing a carbonic acid component solution according to the present invention.

FIG. 4 is a plan view showing the structure of a plastic container containing a carbonate solution according to the present invention.

FIG. 5 is an enlarged sectional view of the container wall shown in FIG.

FIG. 6 is a plan view showing a structure of a plastic container containing a carbonate component solution according to a modification of FIG. 4;

[Explanation of symbols]

 Reference Signs List 1 container 2 carbonate solution 3 container wall

Claims (6)

[Claims] 1. A plastic container containing a solution containing a carbonic acid component, wherein the inner wall surface of the container wall is formed of an alkali-resistant resin, and the carbonic acid component solution has a pH of 7.79 or more and a total carbonic acid component concentration thereof. [C] is in the range of 0.01 to 5.00 mol / L, and the total carbonic acid component concentration [C] and the PH of the solution (hydrogen ion concentration [H +] index) are 7.79 ≦ PH <8. At 95, log [C] ≦ Log (3.83 × 10 ⁻⁴ · K1 / [H +]), and 8.
When 95 ≦ PH ≦ 10.22, log [C] ≦ log (3.83 × 1
^0-4 · K1 / [H +]) + log (1 + K2 / [H +]) Plastic container containing a carbonated component solution, wherein [H +] is hydrogen ions in the solution Concentration mol /
L and K1 are the first dissociation constants of carbonic acid: 4.3 × 10 ⁻⁷ , and K2 is the second dissociation constant of carbonic acid: 5.6 × 10 ⁻¹¹ . ). 2. The carbonic acid component solution has a pH of 8.79 or more, the total carbonic acid component concentration [C] and the hydrogen ion concentration of the solution.
[H +] and the PH of the solution is 8.79 ≦ PH <8.95 time is log [C] ≦ Log (3.83 × 10 -5 · K1 / [H +]),
When 8.95 ≦ PH ≦ 10.5, log [C] ≦ log (3.83 ×
2. The container according to claim 1, wherein the container has a regulation of 10 × 10 ⁻⁵ · K1 / [H +]) + log (1 + K2 / [H +]). 3. The container according to claim 1, wherein
The total carbonic acid component concentration [C] of the solution is regulated by the PH in the above concentration range, and the carbon dioxide gas permeability [V] of the container wall is 0 to 100000 ml / m ² atm (temperature: 25 ° C.).
When the permeability [V] is 16.3 ml / m ² atm (temperature: 25 ° C.) or more, the pH of the solution is 7.79.
[V] ≦ 2.6 × 10 ⁻⁷ / [H +] when ≦ PH <8.95
When 8.95 ≦ PH ≦ 10.9, [V] ≦
^{(2.6 × 10 -7 [H +} ] + 1.4 × 10 - 17) / [H +]
^2. A container characterized by the restrictions of ² . 4. A method for producing a transparent and flexible medical plastic container containing a solution containing a carbonic acid component, wherein the inner wall surface of the container is formed of an alkali-resistant resin, And the total carbonic acid component concentration [C] of the solution is 0.06 or more.
When the solution is adjusted to be in the range of 2 to 5.00 mol / L and the pH of the solution is 8.61 ≦ PH <8.95, the carbonic acid component concentration [C] and the hydrogen ion concentration [H +] Is log [C] ≦ L
og (11.5 × 10 ^-5 · K1 / [H +]), adjust to 8.9
When 5 ≦ PH ≦ 10.39, log [C] ≦ log (11.5 × 10
^-5 · K1 / [H +]) + log (1 + K2 / [H +]), and the carbon dioxide gas permeability [V] of the container wall is 0 to 1000.
00 ml / m ² atm and the permeability [V] is 16.3 ml / m ^2.
If it is atm or more, the pH of the solution is 8.61 ≦ PH <
When 8.95, [V] ≦ 2.6 × 10 ⁻⁷ / [H +], and 8.95
When ≦ PH ≦ 10.9, [V] ≦ (2.6 × 10 ⁻⁷ [H +] + 1.
4 × 10 ⁻¹⁷ ) / [H +] ^{2. A} method for producing a plastic container containing a carbonate solution. 5. The container is double-wrapped in a packaging bag, and the carbon dioxide gas permeability [V] of the packaging bag is 680 ml / m ² atm (temperature 25 ° C.).
The method for producing a container according to claim 4, wherein: 6. The container wall is made of a polyolefin resin,
When the container is used, two or more chambers which can communicate with each other are formed, and at least one chamber accommodates the solution containing the carbonic acid component, and the total carbonic acid component concentration [C] of the solution in the one chamber. Exceeds 0.03 (mol / L) and the pH of the solution is 8.
The method for producing a container according to claim 4 or 5, wherein an acidic solution which lowers the PH value of the mixed solution when the carbonic acid component solution is mixed in more than 8 and in another chamber is accommodated.