JP3250018B2 - Plastic containers for chemicals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic container for chemicals having at least three or more layers and having excellent flexibility, heat resistance and transparency, and excellent dropping of chemicals.

[0002]

2. Description of the Related Art In general, plastic containers for chemicals of this kind are required to have flexibility, heat resistance, transparency and dripping of chemicals. The present applicant has previously arranged an ethylene-propylene random copolymer, and the inner layer has a density of 0.89 to 0.89.
A plastic container having a configuration in which a linear low-density polyethylene of 0.94 g / cm ³ is disposed has been proposed (Japanese Patent Application Laid-Open No. Sho 63/63).
-248634).

[0003]

The plastic container described in the above publication has a problem that the adhesiveness between the inner layer and the outer layer is low, so that delamination is likely to occur between the inner layer and the outer layer. whole inflexible, the drug solution container bag type had a disadvantage of poor dripping of chemical liquid. In particular, when a plastic container is blow-molded, there is a drawback that the parison causes drawdown, the wall thickness becomes non-uniform, and the dropping property of the chemical solution is further reduced.

The present invention has been made in view of the above-mentioned problems in a plastic container having a structure in which an ethylene-propylene random copolymer is disposed in an outer layer and a linear low-density polyethylene is disposed in an inner layer. , Good thickness, uniformity, excellent flexibility, heat resistance, transparency,
It is an object of the present invention to obtain a plastic container for a drug solution having a good dropping property of the drug solution.

[0005]

According to the present invention, at least three of an inner layer, an outer layer and an intermediate layer are provided.
In a plastic container for a chemical solution composed of a layer of plastic, the outer layer is formed so that the ethylene content is 3 to 9% by weight.
And a flexural modulus of 6000 kg / cm ² or less, which is a random copolymer of ethylene and propylene, and is composed of an ethylene-propylene random copolymer, and the inner layer is composed of a copolymer of ethylene and an α-olefin. Density is 0.
910 to 0.925 g / cm ³ and a flexural modulus of 300
Linear low-density polyethylene of 95 to 5 kg / cm ² or less
0% by weight and a density of 0.910 to 0.940 g / cm ³
And a mixture of 5 to 50% by weight of a high-pressure low-density polyethylene having a flexural modulus of 1500 to 3500 Kg / cm ² , and the intermediate layer is formed of 30 to 70% by weight of the ethylene-propylene random copolymer and the linear low- Density polyethylene 7
0 to 30% by weight, the inner layer has a thickness of 50% or more of the whole, and the entire flexural modulus is 3500K.
A plastic container for chemicals with a g / cm ² or less was constructed. Here, an ethylene-propylene random copolymer,
The linear low-density polyethylene and the high-pressure low-density polyethylene are as follows. [Ethylene-propylene random copolymer (EP)] It is a random copolymer of ethylene and propylene, and the content of ethylene in the ethylene-propylene random copolymer is 3 to 9% by weight, preferably Is 4 to 9% by weight. When the content of ethylene is less than 3% by weight, the flexibility of the obtained composition is poor. On the other hand, if it exceeds 9% by weight, it is difficult to produce the resin, and it is difficult to produce it in a satisfactory state. This ethylene-propylene random copolymer has an MFR (JIS K6758) of 0.5 to 0.5.
3.0 g / 10 min, flexural modulus (JIS K7203)
Is 10,000 kg / cm ² or less, preferably 60 kg / cm ² or less.
Those having a weight of 00 kg / cm ² or less can be used. [Linear low-density polyethylene (L-LDPE)] Linear low-density polyethylene is a copolymer of ethylene and another α-olefin, and is different from a low-density polyethylene resin produced by a conventional high-pressure method. As the other α-olefin, for example, those having a carbon number of C 1 to C 12 such as propylene, butene, pentene, hexene, heptene, octene and decene are preferable, and at least one olefin selected from these α-olefins is used. 1 to 20% by weight, preferably 3 to 7% by weight, of 100K by a gas phase method or a liquid phase method using a chromium-based catalyst or a Ziegler catalyst.
g / cm ² or less, preferably 60 kg / cm ² or less. This linear low-density polyethylene is a linear polyethylene having substantially no long-chain branches as a polymer having a structure having short branches, and the density is appropriately reduced by utilizing the short-chain branches. 0.90
It is about 0.925 g / cm ³ , and is a polyethylene having a structure that is more linear than conventional low-density polyethylene and more branched than high-density polyethylene. Its flexural modulus is 3000 kg / cm ² or less. [High-pressure low-density polyethylene (LDPE)] High-pressure low-density polyethylene is ethylene alone or 700 to 3000 kg of ethylene and a small amount of a copolymer component.
/ High-pressure low-density polyethylene polymerized under high pressure of / cm ² . Its density is 0.910 to 0.940 g /
cm ³ , preferably 0.915 to 0.930 g / cm ³ , MFR of 0.01 to 10 g / 10 min, and flexural modulus of 1500 to 3500 Kg / c.
m ² .

[0006]

The plastic container for chemicals according to the present invention has excellent heat resistance, transparency, and can be made thinner and flexible because the ethylene-propylene random copolymer is disposed in the outer layer. Excellent in nature. Also,
The inner layer is made of a mixture of linear low-density polyethylene and high-pressure low-density polyethylene, and has a thickness of 50% or more of the whole, so it has flexibility and transparency. Is good. In addition, since the inner layer that comes into contact with the contents is made of the above-mentioned mixture, the generation of fine particles can be suppressed to a small level, which is hygienic. Furthermore, since the random copolymer of ethylene and propylene is arranged in the intermediate layer, the adhesion between the inner layer and the outer layer is good, and delamination does not occur.

[0007]

1 and 2 show an example of a plastic container for chemicals according to the present invention. The plastic container for chemical liquid 1 is formed by blow molding, and has a mouth 3 at an upper end of a body 2 and a hanging piece 5 on a bottom surface 4. A plug 6 is welded to the mouth 3. As shown in FIG. 3, the chemical liquid plastic container 1 has a three-layer structure including an outer layer 7, an inner 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 the materials constituting the plastic container 1 for chemicals, and Table 2 shows Examples 1 to 3 and Comparative Examples 1 to 3.
3 is shown. Example 1 The outer layer 7 is an ethylene-propylene random copolymer having an ethylene content of 7% by weight, which is abbreviated as EP in Table 1, and the inner layer 8 is abbreviated as L-LDPE in Table 1 A mixture of 70% by weight of linear low-density polyethylene shown and 30% by weight of high-pressure method low-density polyethylene, abbreviated as LDPE. The intermediate layer 9 has an ethylene content of 7% by weight abbreviated as EP in Table 1. 1 and FIG. 2 were blow-molded into a three-layered parison of a mixture of 50% by weight of linear low-density polyethylene, abbreviated as L-LDPE in Table 1 as well as 50% by weight of an ethylene-propylene random copolymer. The plastic container for chemical liquid 1 of the shape shown in FIG. The weight of the obtained chemical liquid plastic container 1 is 20 g, and the container is 6 g.
00 ml, the average thickness of the body 2 is 300 μm, and the thickness of each layer is 210 μm for the inner layer, 45 μm for the middle layer, and 45 μm for the outer layer.
Met. The total flexural modulus at this time is 3000 kg.
/ Cm ² . [Example 2] The thickness of each layer was 150 µm, and the thickness of the intermediate layer was 45 µm.
m, and a plastic container 1 for chemicals was formed in the same manner as in Example 1 except that the outer layer was 105 μm. At this time, the entire flexural modulus was 3,400 kg / cm ² . Example 3 The thickness of each layer was set to 270 μm for the inner layer,
A plastic container 1 for a chemical solution was formed in the same manner as in Example 1 except that the thickness was set to 15 μm and the outer layer was set to 15 μm. At this time, the overall flexural modulus was 2,450 kg / cm ² . Comparative Example 1 The thickness of each layer was set to 120 μm for the inner layer,
A chemical liquid plastic container 1 was formed in the same manner as in Example 1, except that the thickness was 135 μm and the outer layer was 135 μm. The overall flexural modulus at this time was 3650 Kg / cm ² . Comparative Example 2 The thickness of each layer was 280 μm for the inner layer,
A plastic container 1 for a chemical solution was formed in the same manner as in Example 1 except that the thickness was set to 10 μm and the outer layer was set to 10 μm. The overall flexural modulus at this time was 2550 kg / cm ² . [Comparative Example 3] The outer layer 7 is an ethylene-propylene random copolymer having an ethylene content of 7% by weight, which is abbreviated as EP in Table 1, and the inner layer 8 is abbreviated as L-LDPE in Table 1 The two-layer parison of the linear low-density polyethylene shown was blow-molded to form a plastic container 1 for chemical liquid having the shape shown in FIGS. The weight of the obtained plastic container for medical solution 1 is 20 g, the container is 600 ml, and the body 2
Has an average thickness of 300 μm, and each layer has an inner layer thickness of 210 μm.
m, and the outer layer was 90 μm. At this time, the entire flexural modulus was 3,200 kg / cm ² .

Next, the appearance and hygiene of the chemical liquid container 1 and the adhesiveness before the sterilization treatment were evaluated, and 500 ml of the liquid chemical (0.9%
Physiological saline) and 100 ml of clean air.
The appearance, hygiene, dropping properties, and adhesiveness after the sterilization treatment of the plastic container for a drug solution 1 when the sterilization treatment was performed at 15 ° C. for 30 minutes were evaluated.

The appearance was evaluated by visually observing the presence or absence of wrinkles and streaks in the plastic container 1 for chemicals to evaluate the appearance.
In this evaluation, ◎, △, Δ, and × are as follows. ：: There were no wrinkles or streaks on the surface, it was beautiful and the wall thickness was uniform throughout. ：: No wrinkles or streaks were observed on the surface, but there was variation in the thickness. Δ: Some wrinkles and streaks were observed on the surface, and the thickness was uneven. ×: Wrinkles and streaks are observed on the surface, and cannot be used as a plastic container for chemicals.

The hygiene was evaluated by filling the above-mentioned chemical solution into the plastic container for chemical solution 1 and observing the fine particles in the container. In this evaluation, △, Δ, and × are as follows. ：: The number of fine particles is very small. Δ: The number of fine particles is relatively large. ×: The number of fine particles is so large that there is a practical problem. Regarding heat resistance, the appearance of the plastic container for chemical solution 1 after the sterilization treatment was visually observed, and the deformation of the entire plastic container 1 for chemical solution and the body 2 were observed. During this evaluation,
◎, △, Δ, and × are as follows. 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, it is greatly deformed as a whole and cannot be put to practical use.

The drip property is determined by inserting the bottle needle of the chemical solution set into the rubber stopper of the mouth portion 3 after the sterilization treatment, and moving the vein needle 5 times from the position of the bottle needle.
It was fixed at a position lowered by 0 cm, the amount of the drug solution dropped from the venous needle was measured, and the dropping property was evaluated. During this evaluation, ◎, ○,
Δ and × are as follows. 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.

The adhesiveness was evaluated by stripping the body of the plastic container for chemicals of each of the above Examples and Comparative Examples before and after the sterilization treatment into a strip having a width of 15 mm, and performing a 180 ° peeling peel test. The evaluation was performed according to the following evaluation criteria. ：: Peeling is not possible before and after sterilization. Δ: Peeling is not possible before sterilization, but there is a part that peels after sterilization. ×: easily peeled before and after sterilization.

According to Table 2, the total flexural modulus is 3500K.
When it exceeds g / cm ² , it was found that the flexibility as a plastic container for a chemical solution was remarkably reduced as compared with Example 1, Example 2 and Comparative Example 1, and the dropping property of the chemical solution was inferior. From this fact, it is understood that the thickness of the inner layer is required to be 50% or more of the whole in order to obtain a good dropping property of the chemical solution, considering the bending elastic modulus of the plastic constituting each layer.
Further, the thickness of the outer layer was 10% more than that of Example 3 and Comparative Example 2.
When the thickness became thinner, the heat resistance carried on the outer layer could not be sufficiently obtained, and after the sterilization treatment, the whole was greatly deformed and was not practical. Compared to Comparative Example 3, the two-layer structure having no intermediate layer was inferior in adhesive strength, and sometimes caused delamination during use.

[0015]

[Table 3] Table 3 shows Examples 4 to 5 and Comparative Examples 4 to 5. Example 4 The outer layer 7 is an ethylene-propylene random copolymer having an ethylene content of 7% by weight, which is abbreviated as EP in Table 1, and the inner layer 8 is abbreviated as L-LDPE in Table 1 A mixture of 95% by weight of linear low-density polyethylene and 5% by weight of high-pressure low-density polyethylene, abbreviated as LDPE. The mid layer 9 has an ethylene content of 7% by weight abbreviated as EP in Table 1. 1 and FIG. 2 were blow-molded into a three-layered parison of a mixture of 50% by weight of linear low-density polyethylene, abbreviated as L-LDPE in Table 1 as well as 50% by weight of an ethylene-propylene random copolymer. The plastic container for chemical liquid 1 of the shape shown in FIG. The weight of the obtained chemical liquid plastic container 1 is 20 g, and the container is 6 g.
00 ml, the average thickness of the body 2 is 300 μm, and the thickness of each layer is 210 μm for the inner layer, 45 μm for the middle layer, and 45 μm for the outer layer.
Met. The total flexural modulus at this time is 3050 Kg
/ Cm ² . Example 5 The same chemical liquid plastic container 1 as in Example 4 was formed except that the inner layer 8 was a mixture of 50% by weight of linear low-density polyethylene and 50% by weight of high-pressure low-density polyethylene. The total flexural modulus at this time is 2900 Kg
/ Cm ² . Comparative Example 4 A chemical liquid plastic container 1 was formed in the same manner as in Example 4, except that the inner layer 8 was made of a simple substance of 100% by weight of linear polyethylene. The overall flexural modulus at this time is 3
It was 100 kg / cm ² . Comparative Example 5 A chemical liquid plastic container 1 was formed in the same manner as in Example 4 except that the inner layer 8 was a mixture of 40% by weight of linear polyethylene and 60% by weight of high-pressure low-density polyethylene. At this time, the overall flexural modulus is 2900 Kg / c.
m ² .

From Table 3, it was found that 5 to 50% by weight of a high-pressure low-density polyethylene was required in the inner layer relative to a linear low-density polyethylene comprising a copolymer of ethylene and an α-olefin. When the high-pressure-process low-density polyethylene is not mixed into the inner layer as in Comparative Example 4, it can be seen that not only is the hygiene inferior, but also the appearance is inferior. Conversely, when the ratio of the high-pressure low-density polyethylene in the inner layer is increased to more than 50% by weight and becomes 60% by weight as in Comparative Example 5, heat resistance is inferior and large deformation occurs in the sterilized chemical plastic container 1 after sterilization. Was.

As described above, as an embodiment of the present invention, a plastic container for a chemical solution is formed by blow molding, but the present invention is not limited to this. For example,
A plastic film for a chemical solution can be obtained by welding three sides around a laminated film having the same laminated structure as that of the embodiment, and welding parts forming an opening to the other side. Further, a plastic container for a chemical solution can be formed by a known molding method such as injection molding.

[0018]

According to the plastic container for chemicals according to the present invention, the outer layer has an ethylene-propylene random copolymer.
, Heat resistance is good, and it has transparency
At the same time, the thickness can be reduced,
I have. The inner layer is made of linear low-density polyethylene and high-pressure
It is made of a mixture with high density polyethylene and has a thickness of 5
Since it is 0% or more, it has flexibility and transparency.
The liquid type container has good dropping properties
You. Also, the inner layer in contact with the contents is made of the above mixture.
As a result, the generation of fine particles can be reduced
It is a target. Furthermore, ethylene and propylene
Since the random copolymer is arranged, the connection between the inner layer and the outer layer
Good adhesion and no delamination. Soshi
The inner layer and the outer layer have a density of 0.910 to 0.940 g / cm composed of a copolymer of ethylene and α-olefin.
^Since the linear polyethylene of No. ³ was arranged, the intermediate layer was 0.89
Even if it is made of linear polyethylene having a thickness of 0 to 0.905 g / cm ³ , the adhesiveness between the inner layer and the intermediate layer is improved, the thickness becomes uniform, and flexibility, heat resistance, and transparency are improved. It is possible to obtain a plastic container for a drug solution which is excellent and has a very good dropping property of the drug solution.

[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 a partially enlarged sectional view of FIG. 2;

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61J 1/00-1/10 B65D 1/00 B32B 27/00-27/32

Claims (1)

(57) [Claims] At least three of an inner layer, an outer layer and an intermediate layer
The outer layer is a random copolymer of ethylene and propylene having an ethylene content of 3 to 9% by weight and a flexural modulus of 6000 kg / cm ² or less. An inner layer made of a copolymer of ethylene and an α-olefin having a density of 0.910 to 0.925 g / cm ³ and a flexural modulus of 3000 kg / cm ² or less. 95 to 50% by weight of linear low density polyethylene and density of 0.910 to 0.94
The flexural modulus at 0 g / cm ³ is 1500-3500 Kg /
composed of high-pressure low-density mixture of polyethylene 5-50 wt% of the cm ^2, an intermediate layer, the ethylene - propylene random copolymer 30-70 wt% and the linear low density polyethylene 70
A plastic container for a chemical liquid, comprising a mixture with 30% by weight, wherein the thickness of the inner layer is 50% or more of the whole, and the total flexural modulus is 3500 Kg / cm ² or less.