JP3446104B2 - Plastic containers for chemicals - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intravenous infusion such as an amino acid infusion, a fat emulsion, or a high-calorie infusion, an enteral nutrition, a high protein nutrition, or an ingredient. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible plastic liquid medicine container formed by blow molding for filling a liquid medicine of an enteral high-calorie nutrient such as a nutrient or a liquid food. 2. Description of the Related Art Containers of this kind are required to have not only hygiene but also heat resistance, flexibility and transparency. Conventionally, many proposals have been made to obtain this characteristic. These proposals are roughly classified into a blend system and a multilayer system. [0003] Blend systems include polypropylene, ethylene-α-olefin copolymer and propylene-α
A blend of three olefin copolymers (JP-A-2-208339) has been proposed. Further, as a multilayer system, two kinds of propylene-ethylene random copolymers are laminated,
A propylene-ethylene random copolymer having a relatively high ethylene content and a high ethylene content having a relatively high flexibility and a relatively low ethylene content having a relatively low ethylene content and heat resistance. One in which a copolymer is disposed in an outer layer (Japanese Patent Laid-Open No. 3-277366) has been proposed. [0005] Of the blend systems shown in the above-mentioned conventional examples, polypropylene, ethylene-α-olefin copolymer and propylene-α・ Three blends of olefin copolymers must be blended with a considerable amount of a flexible resin, and if the blended amount of this flexible resin increases, compatibility becomes a problem, When filled, impurities are eluted from the inner wall of the plastic container for chemical liquids, which not only impairs hygiene, but also has a drawback that transparency is extremely lowered by blending. Particularly, the heat resistance of the main resin is dragged by the low melting point of the flexible resin to be blended, and the heat resistance sharply decreases. Generally, a chemical solution container is sterilized at a temperature of 121 ° C. or more, and therefore, is required to have heat resistance of at least 121 ° C. However, a chemical solution container made of a resin of this blend type becomes white during sterilization. In addition to devitrification, there is a disadvantage that the container is deformed and dripping of the chemical solution is extremely reduced. In addition, the blend-based materials shown in the above-mentioned conventional examples are basically insufficient in flexibility for spontaneous dropping of a plastic container for chemicals. [0006] Among the multi-layered materials, a propylene-ethylene random copolymer having a high ethylene content and a propylene-ethylene random copolymer having a low ethylene content having heat resistance laminated thereon are laminated at 121 ° C or more. In order to obtain heat resistance, it is necessary to increase the number of layers of propylene-ethylene random copolymer having a low ethylene content and having heat resistance to be disposed on the surface, so that flexibility is impaired as a whole, and dripping of a chemical solution is performed. There is a drawback that the property cannot be obtained. According to these conventional examples, a propylene-ethylene random copolymer is mainly used, and in a blend system, a propylene-ethylene random copolymer is blended with heat-resistant polypropylene. The propylene-ethylene random copolymer is laminated with a propylene-ethylene random copolymer having a lower ethylene content and having higher heat resistance than the propylene-ethylene random copolymer. However, propylene-
It can be said that the additional means for improving the heat resistance of the ethylene random copolymer has caused other new drawbacks. Further, propylene, which is a main component of the conventional example,
It must be said that the ethylene random copolymer itself has a problem in terms of hygiene. Generally, polypropylene is obtained by polymerizing propylene with a Ziegler catalyst, and its structure has some other structure parts, but most of the structure is an isotactic structure. The polypropylene mainly composed of the isotactic structure has a high crystallinity (measured by a DSC method) of 50% or more, and is a highly rigid polypropylene. In order to suppress the height of the rigidity and derive flexibility, flexibility can be obtained by randomly introducing ethylene and suppressing its crystallinity. Therefore, it can be said that the propylene-ethylene random copolymer into which ethylene has been introduced is a polypropylene having both transparency and flexibility. However, propylene-ethylene random copolymers have
Since 9% by weight of ethylene is copolymerized at random, low-molecular-weight products may be generated in which some reactions are likely to cause irregularities and polymerization does not proceed very much. There is a concern that hygiene may be impaired due to precipitation in the inside. As described above, the propylene-ethylene random copolymer is a plastic having flexibility and transparency in propylene, but since it is a copolymer, it has a problem in hygiene. is there. In the present invention, therefore, the heat resistance and flexibility can be obtained by employing a synthetic resin having a substantially syndiotactic structure. Synthetic resin having a substantially syndiotactic structure is basically a polypropylene and therefore has heat resistance, and a polypropylene having a flexible syndiotactic structure has a degree of crystallinity of 35% or less. It is flexible enough to do so. As described above, it is preferable to use low crystallinity polypropylene for the chemical liquid plastic container in terms of heat resistance and spontaneous dropping property. However, as described above, the heat resistance required for this type of container is currently required up to a high temperature of 121 ° C. or higher, but when the amorphous portion is increased by copolymerization to lower the crystallinity, Generally, the heat resistance is also reduced accordingly. Since the plastic container for a drug solution of the present invention is a polypropylene having a flexible, substantially syndiotactic structure, the substantial melting onset temperature (Tsm) is 121 ° C. or higher.
A sterilization temperature of 1 ° C. or higher can provide a container free from elution from the polymer and not whitened or deformed. Further, what is required as a plastic container for a chemical solution is transparency after heat sterilization that allows the state of the chemical solution inside to be seen through. in this way,
In order to obtain heat resistance and transparency, the physical properties measured by DSC are such that the substantial melting onset temperature (Tsm) is 121 ° C. or more and the substantial melting onset temperature (Tsm) and melting end temperature (Tem) Is required to be not more than 30 ° C., but it has become possible to satisfy this with a polypropylene having a substantially syndiotactic structure. Conventionally, a propylene-ethylene random copolymer is widely used in this type of field, as shown in the above-mentioned conventional examples. When this propylene-ethylene random copolymer is used for a chemical liquid plastic container, a highly flexible chemical liquid plastic container having good chemical liquid dropping properties can be obtained without impairing the transparency inside the container. I was However, this propylene-ethylene random copolymer has a drawback that, although the melting peak temperature generally indicating a melting point is around 135 to 140 ° C., it is whitened by a sterilization temperature around 121 ° C. there were. As described above, despite the fact that the melting point exceeds the sterilization temperature, whitening or deformation occurs during sterilization, a temperature standard corresponding to a temperature that can withstand the sterilization temperature has been required. The present inventor has found that a substantial melting onset temperature (Tsm) can be applied as a measure of the temperature that can withstand the sterilization temperature among the melting temperatures used for measuring the melting point. This substantial melting onset temperature (Tsm) is JISK7 as shown in FIG.
The DSC melting peak curve A obtained by the plastic transition temperature measuring method shown in FIG.
From the point at which the propylene-ethylene random copolymer (ethylene content: 6% by weight) used in a conventional plastic container for chemicals is 113.
° C. The inventor measured the sterilization temperature that can withstand using synthetic resins having various substantial melting onset temperatures (Tsm). As a result, the endurable sterilization temperature can be determined from the substantial melting onset temperature (Tsm). Is found. Further, this substantial melting onset temperature (Tsm)
In addition, when the difference between the substantial melting onset temperature (Tsm) and the melting end temperature (Tem) is 30 ° C. or less, polypropylene used in a plastic container for chemicals is transparent and glossy after heat sterilization. Has been found to have Therefore, the present invention aims at the following points. Defects such as whitening or deformation do not occur even in sterilization at 121 ° C or higher. Therefore, a sterilization temperature of 1
Since the temperature can be as high as 21 ° C. or more, the sterilization processing time can be reduced and efficient sterilization can be performed. High flexibility. High transparency after heat sterilization. There should be no eluate from the inner wall even if the inside is filled with a chemical solution. SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a liquid chemical capable of being blow-molded from a synthetic resin having flexibility and allowing the liquid chemical filled therein to be administered by natural dropping. In a plastic container, a flexible synthetic resin has a substantial melting onset temperature (Tsm) of 121 ° C. or less.
Above and substantial melting onset temperature (Tsm) and melting end temperature
The degree of crystallization whose difference from the degree (Tem) is 30 ° C. or less is 35.
% Polypropylene or less, syndiotactic structure
Wherein the at least 85% of the polypropylene is a polypropylene having a substantially syndiotactic structure. [0013] DETAILED DESCRIPTION OF THE INVENTION The present invention, as described above, in the drug solution for plastic containers of flexible filling chemical synthetic resin having flexibility inside was blown, synthetic resin having flexibility, substantially Melting start temperature (Tsm) is 121 ° C or less
Above and substantial melting onset temperature (Tsm) and melting end temperature
The degree of crystallization whose difference from the degree (Tem) is 30 ° C. or less is 35.
% Polypropylene or less, syndiotactic structure
The at least 85% of polypropylene made of substantially syndiotactic structure can withstand a sterilization temperature of 121 ° C.,
Sufficient flexibility for obtaining natural dropping properties is obtained, and transparency that allows the contents to be seen through is obtained. [0014] It is not clear exactly why the flexibility and heat resistance required for a plastic container for chemical liquids can be obtained if the flexible synthetic resin is substantially a polypropylene having a syndiotactic structure. However, it is expected as follows. Plastic has a melting temperature according to the structure of each molecule that melts the molecule by DSC, and there is an amount of heat absorbed at a specific melting temperature. As is well known, when a plastic changes from a solid state to a liquid state or from a liquid state to a solid state, the plastic undergoes a phase change in an adiabatic state, and a large amount of heat enters and exits. This calorific value appears as a deviation from the baseline on the DSC curve. Therefore, polypropylene having a flexible synthetic resin substantially having a syndiotactic structure has a D
Substantial melting onset temperature (Tsm) by SC measurement is 12
Since the difference between the melting start temperature (Tsm) and the melting end temperature (Tem) is not more than 30 ° C.
Prevents the incorporation of substances that melt at temperatures up to
A plastic container for a chemical solution that does not melt-soften at temperatures up to 21 ° C. is obtained. The target heat-resistant temperature is set based on the actual melting start temperature (Tsm) among the temperatures on the DSC curve, not only for preventing the whitening and deformation caused by sterilization but also for the whole. It must not occur in any part. The above-mentioned substantial melting start temperature (Tsm) is a temperature at which a phase change starts to occur, and partial whitening / deformation starts at this temperature. Therefore, by using this temperature as a reference, the temperature at which whitening / deformation starts to occur can be known. Further, polypropylene having a substantially syndiotactic structure has a substantial melting onset temperature (Ts
Since the difference between m) and the melting end temperature (Tem) is 30 ° C. or less, the optical characteristics can be made uniform by reducing the width of the melting temperature and minimizing substances having different melting temperatures. is there. By homogenizing the optical characteristics in this way, transparency and surface gloss after high-temperature sterilization can be obtained, and the content transparency and surface appearance required for a plastic container for a drug solution can be obtained. When synthesizing a plastic, those having different molecular weights and molecular arrangements are mixed and synthesized by a synthesis method such as a catalyst or a polymerization temperature. These have various optical characteristics such as a refractive index. When the difference between the substantial melting start temperature (Tsm) and the melting end temperature (Tem) is 30 ° C. or less, these variations can be reduced by the transparency required for seeing through the contents of the plastic container for chemicals. It is expected that this can be minimized. Further, polypropylene having a syndiotactic structure in which the synthetic resin having flexibility is substantially syndiotactic has sufficient crystallinity of 35% or less, so that sufficient flexibility can be obtained. It was found that a natural dropping property was obtained. In the present invention, the effect can be exerted by using a polypropylene having a substantially syndiotactic structure among polypropylenes. Such a polypropylene is particularly preferably of a steroblock structure in which a crystalline portion and an amorphous portion are mixed, and has sufficient flexibility. In the present invention, a polypropylene having a syndiotactic structure having flexibility has a structure in which substituents R arranged on a vinyl polymer appear alternately above and below a plane. Conventionally, syndiotactic polypropylene has a poor syndiotacticity with a Ziegler-Natta catalyst, and does not exhibit the characteristics of syndiotactic polypropylene which has been known for its existence. By the way, in recent years, a heterogeneous catalyst such as the above-mentioned conventional Ziegler-Natta catalyst, which is different from a transition metal halide and aluminum, an alkaline earth metal or an alkylated compound, is used. Syntheses have been proposed in the field of plastics. In particular, a transition metal compound having an asymmetric ligand such as isopropyl (cyclopentadienyl-1-fluorenyl) hafnium dichloride or isopropyl (cyclopentadienyl-1-fluorenyl) zirconium dichloride as a homogeneous catalyst and aluminoxane It has been found that when a catalyst consisting of is used for the polymerization of propylene, polypropylene having a syndiotactic structure can be obtained at a high rate of 90% or more in syndiotacticity. The flexible, substantially syndiotactic polypropylene of the present invention has a substantial melting onset temperature (Tsm) of at least 121 ° C., a substantial melting onset temperature (Tsm) and a melting end temperature. (Tem) is 3
It is a polypropylene having a crystallinity of 0% or less and a crystallinity of 35% or less, and at least 85% of a polypropylene having a syndiotactic structure is required. Other polypropylenes, such as polypropylene with an atactic structure and polypropylene with an isotactic structure, as well as those obtained by graft polymerization of ethylene or the like to these polypropylenes, as long as the necessary physical properties of the plastic container for chemicals are not impaired. It is. FIG. 1 and FIG. 2 show a plastic container for chemicals of the present invention. This plastic container 1 for chemicals is manufactured by blow molding, and has a mouth 3 at an upper end of a body 2 and a bottom 4 and a hanging piece 5 at a lower end of the body 2. A plug 6 is welded to the mouth 3. Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples. [Table 1] A plastic container 1 for chemicals shown in FIGS. 1 and 2 was blow-molded with a plastic having the structure shown in Table 1. The plastic container 1 for chemicals has a content of 700
ml, the average wall thickness is 0.35 mm, and the container weight is 35
g. The syndiotactic polypropylene, ethylene-propylene random copolymer and isotactic polypropylene shown in Table 1 are as follows. (Syndiotactic polypropylene) A polypropylene having a syndiotactic structure comprising a homopolymer of propylene, which is obtained by polymerizing propylene using a catalyst comprising isopropyl zirconium dichloride and methylaluminoxane. The proportion containing the structure polypropylene is 9
1%. (Propylene-ethylene random copolymer) A copolymer of propylene with a small amount of ethylene. Ethylene was formed at random positions in propylene, and the ethylene content was 6% by weight. . (Isotactic polypropylene) An isotactic polypropylene comprising a homopolymer of propylene, which is obtained by polymerizing propylene using a Ziegler catalyst, and having a propylene component having another structure such as a slight atactic structure. Is included. [Table 2] [Table 3] ◎, ○, △, × shown in Tables 2 and 3 represent
The following evaluation results are shown. (Transparency) The total light transmittance, which is the ratio of the amount of incident visible light having a wavelength of 450 nm and the amount of total light transmission specified in JIS K6714, is shown. Table 2 shows the total light transmittance before sterilization.
Sterilization treatment was performed for 30 minutes at a treatment temperature of 1 ° C., 130 ° C., and 140 ° C., respectively, and the total light transmittance after the sterilization treatment is shown in Table 3. (Hygiene) Filling with pure water, 121 ° C., 30
Table 2 shows the results of measuring and evaluating the number of microparticles based on a test for a plastic container for infusion in the Japanese Pharmacopoeia after sterilization in minutes. A: Very little. ：: good. Δ: Somewhat poor. X: Poor. (Dripability) The dripability was determined by sterilizing a container filled with pure water at 121 ° C. for 30 minutes, inserting a bottle needle of a chemical solution set into a rubber stopper at the mouth, and placing the venous needle at the position of the bottle needle. From 50c
Table 2 shows the results of measuring the amount of the drug solution dropped from the vein needle and evaluating the dropping property. A: There was no variation in the amount of dripping per hour, and the dripping property was good. ：: The dropping amount was good although the amount of dropping per hour varied slightly. Δ: There was a large variation in the amount of drop per hour, and there was a problem in practical use. X: The dripping property is extremely poor. (Deformation) Deformation after sterilization is as follows. A container filled with pure water is subjected to a sterilization treatment at 121 ° C., 130 ° C., and 140 ° C. for 30 minutes each, and a plastic container for a chemical solution after each sterilization treatment. Table 3 shows the result of observing the appearance of No. 1 visually and observing the deformation of the entire plastic container 1 for chemicals and the body 2. 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: The whole was greatly deformed after sterilization, and could not be put to practical use. As shown in Tables 1 to 3, the plastic container for chemicals made of syndiotactic polypropylene shown in Example 1 has heat resistance, especially heat resistance of 130 ° C. or more, and has both hygiene and dripping properties. There was found. As described above, the present invention has flexibility.
Blow molding of synthetic resin
Smell in plastic containers for chemicals that can be administered by dripping
The flexible synthetic resin has a substantial melting onset temperature.
(Tsm) of 121 ° C. or higher and substantial melting onset temperature
The difference between (Tsm) and the melting end temperature (Tem) is 30 ° C or less.
The lower polypropylene having a crystallinity of 35% or less
Less syndiotactic polypropylene
And 85% of substantially syndiotactic polyp
Because it is ropylene , even in sterilization at 121 ° C or higher,
It has heat resistance that does not cause whitening or deformation, and has good dropping properties as a plastic container for chemicals,
In addition, since there is no eluate from the inner wall, it has an effect of being extremely sanitary.

[Brief description of the drawings] FIG. 1 is an elevation view of a hollow container according to the present invention. FIG. 2 is a side view of the hollow container according to the present invention. FIG. 3 is a diagram showing a melting curve by DSC. [Explanation of symbols] 1 Plastic containers for chemicals 2 torso 3 mouth 4 bottom 5 hanging pieces 6 plug

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61J 1/10 B65D 1/09

Claims (1)

(57) [Claim 1] In a plastic container for chemical liquid which can be blow-molded with a flexible synthetic resin and a liquid medicine filled therein can be administered by natural dropping, a flexible synthetic resin is used. The actual melting onset temperature (Tsm) is 121 ° C. or higher
And substantial melting onset temperature (Tsm) and melting end temperature
(Tem) is less than 30 ° C. and the degree of crystallinity is 35%
The following polypropylene with a syndiotactic structure
The plastic container for a drug solution , wherein the polypropylene is at least 85% of a polypropylene having a substantially syndiotactic structure.