JP3250016B2 - Blow container for chemical solution - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical solution blow container manufactured by blow molding which can be sterilized at a high temperature.

[0002]

2. Description of the Related Art Generally, this type of chemical liquid blow container is required to have hygiene, flexibility, transparency and heat resistance. The present applicant has previously stated that the inner layer and the outer layer have a density of 0.910 to 0.940 g made of a copolymer of ethylene and α-olefin.
/ Cm ³ of linear polyethylene, and a plastic container made of linear polyethylene having a density of 0.890 to 0.905 g / cm ^{3 in} the intermediate layer (JP-A-63-2).
No. 48633).

[Problems to be solved by the invention]

[0003] The container according to the invention disclosed in the above publication is 10
Although it has sufficient heat resistance to sterilization at 5 ° C, in recent years, sterilization at higher temperatures has been performed.
There has been a demand for a material having even higher heat resistance, for example, which can withstand a sterilization treatment at 115 ° C. or higher. Thus, the density of the copolymer of ethylene and α-olefin is 0.1.
Among linear polyethylene of 910 g / cm ³ or more,
Α- per 1000 carbon atoms in ethylene in the main chain
It is conceivable to improve the heat resistance by using a heat-resistant linear polyethylene having 10 or less short-chain olefins, but such a heat-resistant linear polyethylene has good heat resistance. However, it lacks flexibility and has poor blow moldability, drawdown occurs in the parison during extrusion, and the thickness distribution of the container due to non-uniform elongation, especially during blowing, becomes non-uniform. But not
Pinholes may occur and cannot be used as blow containers for chemicals.

[0004] In view of the above, the present invention is rich in flexibility, good in transparency, can see through a chemical solution contained in the inside, and does not become uneven in thickness even by blow molding. Even if sterilization is performed at a high temperature of 115 ° C or more,
It is an object of the present invention to obtain a chemical solution blow container having sufficient heat resistance without causing whitening, devitrification, or deformation.

[0005]

In order to achieve the above object, the present invention provides a chemical solution blow container formed by blow-molding a multilayer parison comprising an inner layer, an outer layer and an intermediate layer. Has 1 to 15 short-chain branches of α-olefin, and has a density of 0.930 to
Oh at 0.970 g / cm ³ of linear polyethylene (A)
In the intermediate layer, the short-chain branching of the α-olefin is 20 to 7
0 pieces and the density is 0.890 to 0.925 g / c
linear polyethylene of m ³ (B) with 95 to 50% by weight and density mixture of high-pressure polyethylene 5-50 wt% of 0.915~0.935g / cm ^3, and the density of the mixture 0.890 0.95 g / cm ³ , wherein the thickness of the intermediate layer is at least 40 to 80% of the total thickness. It is what it was. Here, the linear polyethylene (A), the linear polyethylene (B), and the high pressure polyethylene are as follows. [Linear polyethylene (A)] Linear polyethylene (A) is ethylene and carbon number 3 ~.
And a copolymer with an α-olefin (propylene, butene, pentene, hexene, octene, decene, etc.) of 100 kg / cm ² by a gas phase method or a liquid phase method using a chromium catalyst or a Ziegler catalyst. The polyethylene is produced at a low pressure of preferably 60 kg / cm ² or less, and has a molecular structure of linear polyethylene in which a short chain branch of α-olefin is formed with respect to a linear main chain of ethylene. The number of short-chain branches of the α-olefin per 1000 carbon atoms in ethylene is from 1 to 15, and the density is 0.1.
It has a high density of 930 to 0.970 g / cm ³ . [Linear polyethylene (B)] Linear polyethylene (B) is ethylene and carbon number 3-.
12 is a copolymer with an α-olefin (propylene, butene, pentene, hexene, octene, decene, etc.) and is 100 kg / cm ² or less by a gas phase method or a liquid phase method using a chromium catalyst or a Ziegler catalyst. Preferably, it is produced at a low pressure of 60 kg / cm ² or less, and has a molecular structure of linear polyethylene in which α-olefin short-chain branching is formed with respect to ethylene linear main chain. The number of short-chain branches of the α-olefin per 1000 carbon atoms in ethylene is 20 to 70, and the density is 0.
It has a low density of 890 to 0.925 g / cm ³ . [High-pressure polyethylene] High-pressure polyethylene refers to ethylene alone or a mixture of ethylene and a small amount of a copolymer component in the range of 700 to 3000.
A high-pressure low-density polyethylene polymerized under a high pressure of Kg / cm ² and having a long-chain branch with respect to the main chain of ethylene. Its density is 0.915 ~ 0.94
0 g / cm ³ , preferably 0.915 to 0.930 g /
cm ³ and an MFR of 0.01 to 10 g /
It means 10 minutes.

[0006]

The chemical liquid blow container according to the present invention has an inner layer and an outer layer each having 1 to 15 short-chain branches of α-olefin,
Since it is composed of linear polyethylene (A) having a density of 0.930 to 0.970 g / cm ³ , it is not whitened, devitrified or deformed even when sterilized at a high temperature of 115 ° C. or more. Since the linear polyethylene (A) is disposed in the inner layer even if it is separated, the generation of fine particles is small even after the steam sterilization treatment at 115 ° C., which is extremely sanitary.
The intermediate layer has 20 to 70 short-chain α-olefin branches, and has a density of 95 to 50% by weight of linear polyethylene (B) having a density of 0.890 to 0.925 g / cm ³ and a density of 0.91.
High-pressure polyethylene of 5 to 0.935 g / cm ³
0% by weight, and the density of the mixture is 0.890
0.925 g / cm ³ , and the thickness of the intermediate layer is at least 40 to 80% of the total thickness, thereby preventing drawdown from occurring during extrusion of the parison and improving the elongation at the time of blowing. Uniformity can be achieved, and uneven thickness can be prevented. In general, since the linear polyethylene (A) and the linear polyethylene (B) have a narrow molecular weight distribution, they are susceptible to a slight temperature change at the time of melting, so that the temperature of the parison may be uneven, or the parison may be easily cooled. In addition, unevenness occurs in the expansion of the parison during blow molding, and the wall thickness becomes non-uniform. However, in the present invention, since the high-pressure polyethylene is mixed as described above, the thermal instability of the linear polyethylene (B) at the time of melting is compensated for.
Thermal stability during extrusion or blowing can be obtained, and as a result, drawdown during extrusion can be prevented, and uneven thickness at the time of blowing can be prevented. In addition, the decrease in heat resistance due to the mixing of high-pressure polyethylene is minimized by arranging the mixture in the intermediate layer, and the decrease in heat resistance is suppressed. Deformation can be prevented. Further, the chemical solution blow container according to the present invention is entirely composed of low-density linear polyethylene, and particularly has a density of 0.890 to 0.925 g /
Since the thickness of the low-density intermediate layer of cm ³ and 40% to 80% of the total, greater flexibility of the drug solution for blow container itself, transparency is good, good dropping of chemical solution stored inside can do.

[0007]

1 and 2 show an example of a chemical solution blow container according to the present invention. This chemical solution blow container 1 is formed by blow molding,
Has a mouth 3 at the upper end and a hanging piece 5 on the bottom 4.
A plug 6 is welded to the mouth 3. As shown in FIG. 3, the chemical solution blow container 1 has a three-layer structure of an inner layer 7, an outer layer 8, and an intermediate layer 9.

Hereinafter, the present invention will be described in detail with reference to examples.

[Table 1]

[Table 2] Table 1 exemplifies materials constituting the chemical solution blow container 1, and Table 2 shows Examples 1 to 3 and Comparative Examples 1 and 2. [Example 1] The inner layer 7 and the outer layer 8 are shown in Table 1 as LPE
(A) Linear polyethylene (A) having six short-chain branches of α-olefin, abbreviated as (A),
70% by weight of linear polyethylene (B) having 45 short-chain branches of α-olefin, abbreviated as LPE (B) 1
And 30% by weight of high pressure polyethylene (density: 0.1%).
906 g / cm ³ ) of a three-layer parison was blow-molded to form a chemical solution blow container 1 having the shape shown in FIG. The obtained chemical solution blow container 1 weighs 20 g and has a capacity of 600 m.
The average thickness of the body 2 was 0.3 mm, and the thickness of each layer was 45 μm for the inner layer, 210 μm for the intermediate layer, and 45 μm for the outer layer. [Example 2] A mixture of 50% by weight of linear polyethylene (B) and 50% by weight of high-pressure polyethylene (density: 0.910 g / c), in which the intermediate layer 9 is abbreviated as LPE (B) 1 in Table 1
m ³ ), and the other components are the same as those of the first embodiment.
Was molded. Example 3 The intermediate layer 9 is a mixture of 95% by weight of linear polyethylene (B) and 5% by weight of high-pressure polyethylene (density: 0.901 g / cm), abbreviated as LPE (B) 1 in Table 1.
^The procedure was the same as in Example 1 except that the chemical liquid blow container 1 was molded. [Comparative Example 1] A mixture of 40% by weight of linear polyethylene (B) and 60% by weight of high-pressure polyethylene (density: 0.912 g / c), in which the intermediate layer 9 is abbreviated as LPE (B) 1 in Table 1
m ³ ), and the other components are the same as those of the first embodiment.
Was molded. Comparative Example 2 A chemical liquid blow container 1 was formed in the same manner as in Example 1 except that the intermediate layer 9 was made of only the high-pressure polyethylene shown in Table 1.

Next, the appearance and transparency of the chemical solution blow container 1 were evaluated, and the chemical solution blow container 1 was filled with 500 ml of an infusion solution (0.9% saline) and 100 ml of clean air. Transparency, deformability and dropping property were evaluated for the chemical solution blow container 1 after steam sterilization at 115 ° C. for 30 minutes. Here, the appearance was evaluated by visually observing the presence or absence of wrinkles and streaks in the chemical liquid blow container 1 and evaluating the appearance. In the evaluation results, ◎, △, Δ, and × are as follows. ：: There were no wrinkles or streaks on the surface, and the entire thickness was uniform and beautiful. ：: No wrinkles or streaks were found on the surface, but there was thick harakiness. Δ: Some wrinkles and streaks were observed on the surface, and the thickness was uneven. ×: Wrinkles and streaks were observed on the surface, and it could not be used as a chemical liquid blow container. Total light transmittance is 450 n specified in JIS K6714.
It represents the ratio between the amount of incident visible light having a wavelength of m and the amount of total light transmission. The total light transmittance of the body wall of the chemical solution blow container 1 before and after sterilization is measured and expressed as a percentage. Expressed. Deformation after sterilization is caused by the chemical solution blow container 1 after sterilization.
Was visually observed, and the deformation of the entire chemical liquid blow container 1 and the body 2 were observed. ◎, ○, Δ, × indicate the following evaluation results, respectively. A: After sterilization, the shape was the same as before sterilization, and no deformation was observed. ：: No significant deformation was observed even after sterilization. Δ: After sterilization, the bottom part expanded to form an unsightly shape. X: After sterilization, the whole was greatly deformed and could not be put to practical use. The drip property was measured by inserting the bottle needle of the drug solution set into the rubber stopper of the mouth portion 3 after sterilization, fixing the venous needle at a position lowered by 50 cm from the position of the bottle needle, and measuring the amount of the drug solution dropped from the venous needle. And the dripping properties were evaluated. A: There was no variation in the amount of dripping per hour, and the dripping property was good. ：: The dripping property was good although there was some variation in the dripping amount per time. Δ: There is a large variation in the amount of dripping per hour, and there is a problem in practical use. X: The dripping property is extremely poor. From Table 2, the mixing of the high pressure polyethylene indicated by LDPE to be mixed into the intermediate layer is up to 50% by weight.
It was found that when the amount exceeds 10% by weight, not only the transparency before sterilization decreases, but also the thermal effect of the sterilization causes large devitrification and the total light transmittance decreases to 70% or less. According to the embodiment, after the sterilization treatment at 115 ° C., the decrease in the total light transmittance can be suppressed to around 85%. This is because the devitrification does not proceed further by mixing the high-pressure polyethylene within the range of the present invention.
Exceeds 60% by weight, for example, if it is mixed at 60% by weight, it devitrifies to 70% level. From Table 2, it was found that by mixing high pressure polyethylene into the intermediate layer, the blow moldability was improved, and the appearance and the dropping property of the chemical solution were improved as compared with Comparative Example 2.
This effect can be sufficiently obtained by mixing 5% by weight or more of high pressure polyethylene.

[0010]

[Table 3] Table 3 shows Examples 4 to 5 and Comparative Examples 3 and 4. Example 4 The inner layer 7 and the outer layer 8 are shown in Table 1 as LPE
(A) Linear polyethylene (A), abbreviated as “A”, Intermediate layer 9 is LPE (B) 1, linear polyethylene (B)
A three-layer parison of a mixture of 70% by weight and 30% by weight of high-pressure polyethylene (density: 0.906 g / cm ³ ) was blow-molded to form a chemical liquid blow container 1 having the shape shown in FIG. The obtained chemical solution blow container 1 weighs 20 g, has a capacity of 600 ml, and has an average wall thickness of 0.3 mm.
The thickness of each layer is 90 μm for the inner layer, 120 μm for the intermediate layer, and 9 μm for the outer layer.
It was 0 μm. Example 5 The same configuration as that of Example 4 was adopted, and the obtained chemical solution blow container 1 weighed 20 g, had a capacity of 600 ml, and had a body 2
Has an average thickness of 0.3 mm, and each layer has an inner layer thickness of 30 μm.
m, the intermediate layer was 240 μm, and the outer layer was 30 μm. [Comparative Example 3] With the same structure as in Example 4, the weight of the obtained chemical solution blow container 1 was 20 g, the capacity was 600 ml, and
Has an average thickness of 0.3 mm, and the thickness of each layer is
m, the intermediate layer was 90 μm, and the outer layer was 105 μm. [Comparative Example 4] The weight of the chemical solution blow container 1 obtained with the same configuration as in Example 4 was 20 g, the capacity was 600 ml, the average thickness of the body 2 was 0.3 mm, and the thickness of each layer was 15 μm of the inner layer. ,
The intermediate layer was 270 μm, and the outer layer was 15 μm. From Table 3, it has been found that the thickness of the intermediate layer is preferably 40% to 80% of the whole in terms of appearance, moldability, and heat resistance. As the ratio of the thickness of the intermediate layer increases, the degree of opacity due to the sterilization treatment increases, and the deformation after sterilization increases. If the thickness of the intermediate layer exceeds 90% and becomes 90%, the total light transmittance after sterilization will be on the order of 70%. In general, a chemical solution blow container is required to be able to see through the inside. However, when the total light transmittance is on the order of 70%, the precipitated fine particles cannot be found, and cannot be put to practical use. Therefore, considering the heat resistance against sterilization, the thickness of the intermediate layer is up to 80%, and conversely, the combined thickness of the inner layer and the outer layer which depend on the heat resistance is 20% or more, preferably the outer layer. Needs to be 10% or more. When the thickness of the intermediate layer is less than 40%, the appearance after molding is reduced, and the dropping property is also reduced. Therefore, considering these points, the thickness of the intermediate layer is 40%.
It turned out to be necessary.

[0011]

[Table 4] Table 4 shows Examples 6 to 7 and Comparative Examples 5 to 6. Example 6 The inner layer 7 and the outer layer 8 are shown in Table 1 as LPE
70% by weight of linear polyethylene (A) abbreviated as (A) and linear polyethylene (B) having 35 short-chain branches of α-olefins abbreviated as LPE (B) 2 in Table 1 3
0% by weight of a mixture (density: 0.935 g / cm ³ ), and the intermediate layer 9 is a mixture of 70% by weight of linear polyethylene (B) abbreviated as LPE (B) 1 and 30% by weight of high-pressure polyethylene (density: 0). .906 g / cm ³ ) of a three-layer parison was blow-molded to form a chemical liquid blow container 1 having the shape shown in FIG. The weight of the obtained chemical solution blow container 1 is 20
g, capacity is 600ml, average thickness of body 2 is 0.3m
m, the thickness of each layer is 45 μm for the inner layer, 210 μm for the intermediate layer,
The outer layer was 45 μm. Example 7 The inner layer 7 and the outer layer 8 are shown in Table 1 as LPE
(A) Linear polyethylene (A), abbreviated as “A”, and Intermediate layer 9 is linear polyethylene (B), abbreviated as LPE (B) 2
A three-layer parison of a mixture of 70% by weight and 30% by weight of high-pressure polyethylene (density: 0.920 g / cm ³ ) was blow-molded, and a chemical liquid blow container 1 was formed in the same manner as in Example 6 except for the above. [Comparative Example 5] The inner layer 7 and the outer layer 8 are shown in Table 1 as LPE
A mixture of 50% by weight of linear polyethylene (A) abbreviated as (A) and 50% by weight of linear polyethylene (B) abbreviated as LPE (B) 2 in Table 1 (density: 0.929 g)
/ Cm ³ ), the intermediate layer 9 is composed of 70% by weight of linear polyethylene (B) abbreviated as LPE (B) 1 and high pressure polyethylene 3
0% by weight of the mixture (density: 0.906 g / cm ³ )
The layer parison was blow-molded, and the other steps were the same as in the example, except that the chemical liquid blow container 1 was formed. [Comparative Example 6] The inner layer 7 and the outer layer 8 are shown in Table 1 as LPE (A).
A mixture of 50% by weight of linear polyethylene (A) and 50% by weight of high pressure polyethylene (density: 0.92)
8 g / cm ³ ), and the intermediate layer 9 was formed by blow molding a three-layer parison of linear polyethylene (B), abbreviated as LPE (B) 1, and the same chemical liquid blow container 1 as in Example 6 was formed. From Example 6 and Comparative Example 5, the outer layer and the inner layer
Even if 30% by weight of LPE (B) 2 is mixed with PE (A),
It has been found that the effects of the present invention can be obtained. However, when the amount of mixing exceeded 30% by weight, as in Comparative Example 5, LPE
When (B) 2 is mixed at 40% by weight, the transparency after sterilization at 115 ° C. is extremely reduced. At this time, it was found that the synthetic resin constituting the outer layer and the inner layer had a density of 0.930 g / cm ³ and a phenomenon of devitrification after sterilization occurred. This means that the total light transmittance after molding is the same, but the density of the synthetic resin of the outer layer and the inner layer is 0.930 g /
If it is less than cm ^3, it will be extremely reduced. Therefore, the resin that can be mixed with the linear polyethylene (A) that is the main resin constituting the outer layer and the inner layer is the linear polyethylene (B).
Among them, those having a density of 0.910 g / cm ³ or more and the number of short-chain branches of α-olefin depend on the kind of α-olefin to be copolymerized.
~ 40, butene 20 ~ 30 can be used,
The amount of the mixture is such that the density of the mixture is 0.930 g / cm ^3.
Mixing as described above is important in terms of heat resistance. Also, as in Example 7, linear polyethylene (B)
Among them, the effect of the present invention can be obtained by mixing low-density linear polyethylene (B) having a density of 0.920 g / cm ³ into the intermediate layer. Since the density of the intermediate layer is further reduced and the flexibility is increased, dripping properties are further improved, and sufficient heat resistance can be obtained. From Comparative Example 6, when the mixing position of the high pressure polyethylene was mixed into the outer layer and the inner layer, the total light transmittance after molding was the same as that mixed into the intermediate layer, but the total light transmittance after sterilization was significantly higher. change. That is, since the mixture of the outer layer and the inner layer is directly heated, the heat resistance is low, the heat is largely affected by the heat, and the total light transmittance from 89% before sterilization is drastically reduced to the 70% level. . As in the present invention, it has been found that the mixing position of the high-pressure polyethylene must be an intermediate layer. By mixing high-pressure polyethylene in the intermediate layer as in the present invention, it is possible not only to prevent direct heat from being applied to high-pressure polyethylene having low heat resistance, but also to increase the thickness of the intermediate layer. Thus, even if the mixing ratio of the high-pressure polyethylene is small, there is an advantage that a large absolute amount can be mixed, and conversely, the heat resistance can be improved.

[0012]

The blow container for chemicals according to the present invention has an inner layer
And the outer layer has 1 to 15 short-chain branches of α-olefin.
Yes, linear with a density of 0.930 to 0.970 g / cm ³
Since it is composed of polyethylene (A), it has a high temperature of 115 ° C or more.
Whitening, devitrification or deformation even after sterilization at temperature
The inner layer has no linear polyethylene
After the ren (A) was placed, after steam sterilization at 115 ° C
Is very hygienic, with little particulate generation.
In the intermediate layer, short-chain branches of α-olefin are 20 to 70.
And has a density of 0.890 to 0.925 g / cm ³ .
The linear polyethylene (B) has a density of 95 to 50% by weight and a density of 0.1%.
915 to 0.935 g / cm ³ high pressure polyethylene 5
-50% by weight, the density of the mixture being 0.8
90 to 0.925 g / cm ³ , the thickness of the intermediate layer
At least 40-80% of the total wall thickness.
Prevent drawdowns when extruding listen
As well as uniform elongation during blowing
Non-uniform thickness can be prevented. And in the present invention
According to the high pressure polyethylene mixed as above
To reduce the thermal instability of linear polyethylene (B) during melting.
In addition, thermal stability during extrusion and blowing can be obtained.
As a result, drawdown during extrusion is prevented, and
It is possible to prevent uneven thickness. In addition, high pressure method
The decrease in heat resistance due to the mixing of ethylene
Layered layers minimize heat resistance and reduce heat resistance
Suppress the bottom, so that whitening by sterilization at 115 ° C.
Devitrification or deformation can be prevented. In addition,
Blow containers for chemicals according to Ming
Composed of ethylene, especially with a density of 0.890-0.9
The thickness of the low-density intermediate layer of 25 g / cm ³
80%, the flexibility of the chemical solution blow container itself is high
Good transparency and good dripping of chemicals stored inside.
Can be good .

[Brief description of the drawings]

FIG. 1 is a front view of a chemical liquid plastic container according to the present invention.

FIG. 2 is a side view of the plastic container for chemical liquid according to the present invention.

FIG. 3 is an enlarged sectional view showing a portion surrounded by a broken line in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blow container for chemical | medical solution 2 Body 3 Mouth 4 Bottom surface 5 Hanging piece 6 Plug body 7 Inner layer 8 Outer layer 9 Middle layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A61J 1/10 B65D 1/00 B65D 23/00-23/02

Claims (1)

(57) [Claims] 1. A chemical liquid blow container formed by blow-molding a multilayer parison comprising an inner layer, an outer layer and an intermediate layer, wherein the inner layer and the outer layer have a short chain branch of α-olefin of 1 to 1.
15 pieces and density 0.930 ~ 0.970g / cm
³ , wherein the intermediate layer has 20 to 70 short-chain branches of α-olefin, and has a density of 0.890 to 0.925 g / cm ^3.
Of a linear polyethylene (B) of 95 to 50% by weight and a high-pressure polyethylene having a density of 0.915 to 0.935 g / cm ³ of 5 to 50% by weight, and the density of the mixture is 0.890 to 0 0.925 g / cm ³ , and the thickness of the intermediate layer is at least 40 to 80 of the total thickness.
%. Blow container for chemicals, characterized in that the percentage is set to%.