JPH0242501B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a medical soft vinyl chloride resin composition and a medical device. Specifically, the present invention relates to medical soft vinyl chloride resin compositions and medical devices that have extremely high safety and do not cause hemolysis when they come into contact with blood. (Prior Art) Currently, blood storage containers and other medical devices made of soft vinyl chloride resin are widely used because of their good moldability, flexibility, transparency, heat resistance, and low cost. ing. By the way, the soft vinyl chloride resin used for medical purposes as described above usually uses di-2-ethylhexyl phthalate (DOP) as a plasticizer. However, since phthalate ester plasticizers generally have a high migration property, it is known that, for example, when a soft vinyl chloride resin such as the one mentioned above comes into contact with blood, di-2-ethylhexyl phthalate will be eluted into the blood. (Medical Science 54 221
(1984)). It has been reported that di-2-ethylhexyl phthalate suppresses the aggregation ability of platelets (Journal of the Japan Society for Blood Cycle Blood Cycles, 28(3)282 (1981)). When blood is stored in a container, there is a risk that di-2-ethylhexyl phthalate may enter the body along with the stored blood during blood circulation, which is problematic from the perspective of affecting platelet function. Ta. In order to solve this problem, the use of materials that do not contain di-2-ethylhexyl phthalate has been considered, but storage containers constructed using materials that do not contain di-2-ethylhexyl phthalate It has become clear that when blood is stored, red blood cells become hemolyzed during storage. When the cause of this was investigated, it was found that this is because di-2-ethylhexyl phthalate has a hemolysis inhibiting effect (Blood 64 6 1270~ (1984) [Blood 64 6
1 270−(1984)]). In other words, when blood is stored in a conventional blood storage container made of soft vinyl chloride resin containing di-2-ethylhexyl phthalate as a plasticizer, di-2-ethylhexyl phthalate eluted into the blood is absorbed into red blood cells. This suppressed hemolysis. For these reasons, while taking precautions against the effects of di-2-ethylhexyl phthalate on living organisms, soft vinyl chloride resin compositions containing di-2-ethylhexyl phthalate are recommended as medical soft vinyl chloride resin compositions for medical devices. Currently, vinyl chloride resin is used. (Problems to be Solved by the Invention) Therefore, an object of the present invention is to provide a novel medical soft vinyl chloride resin composition and a medical device. Another object of the present invention is to provide a medical soft vinyl chloride resin composition and a medical device that have excellent preservability for red blood cells. A further object of the present invention is to provide a medical soft vinyl chloride resin composition and a medical device with high physiological safety. A further object of the present invention is to provide a medical soft vinyl chloride resin composition and a medical device that can be sterilized in an autoclave and have heat resistance, high transparency, flexibility, and processability. (Means for solving the problems) The above objects are made by using a vinyl chloride resin plasticizer and the general formula () RCOOR' () (where R and R' are each a chain hydrocarbon group having 3 or more carbon atoms. and the sum of the carbon numbers of R and R' is 11 to 30. . The present invention also provides 10 to 45% by weight of a plasticizer and 1 to 45% of a monocarboxylic acid ester represented by the general formula ().
This shows a medical soft vinyl chloride resin composition containing 30% by weight. The present invention also provides a medical soft vinyl chloride resin composition in which at least one of R or R' in the general formula () has a branched structure. The present invention also provides a medical soft vinyl chloride resin composition in which at least one of R or R' in the general formula () has a branched structure. The present invention further provides a medical soft vinyl chloride resin composition which is a compound represented by the general formula (): isopropyl isolaurate, isopropyl oleate, 2-ethylhexyl isostearate or 2-ethylhexyl-2-ethylhexanoate. It shows. The present invention also provides a medical soft vinyl chloride resin composition in which the plasticizer has low elution properties. The present invention further provides a medical soft vinyl chloride resin composition in which the plasticizer is selected from the group consisting of trialkyl trimellitates, dinormal alkyl phthalates, and tetraalkyl pyromellitates. The present invention further provides a medical soft vinyl chloride resin composition in which the plasticizer is di-normaldecyl phthalate. The present invention further provides a medical soft vinyl chloride resin composition in which the plasticizer is trioctyl trimellitate. The above objects further include a vinyl chloride resin, a plasticizer, and the general formula () RCOOR' () (wherein R and R' are each a chain hydrocarbon group having 3 or more carbon atoms, and R and R' Achieved by a medical device characterized in that it is substantially composed of a soft vinyl chloride resin composition comprising a monocarboxylic acid ester represented by be done. The present invention also provides 10 to 45% by weight of a plasticizer and 1 monocarboxylic acid ester represented by the general formula ().
This shows a medical device characterized in that it is substantially composed of a soft vinyl chloride resin composition containing up to 30% by weight. The present invention also provides a medical device in which at least one of R or R' in the general formula () has a branched structure. The present invention further provides a medical device in which the compound represented by the general formula () is isopropyl isolaurate, isopropyl oleate, 2-ethylhexyl isostearate or 2-ethylhexyl-2-ethylhexanoate. The present invention also provides medical devices in which the plasticizer has low elution properties. The invention further provides a medical device in which the plasticizer is selected from the group consisting of trialkyl trimellitates, di-normal alkyl phthalates and tetraalkyl pyromellitates. The invention further provides a medical device in which the plasticizer is di-normaldecyl phthalate. The invention further provides a medical device in which the plasticizer is trioctyl trimellitate. The present invention also provides a medical device characterized in that it is a blood storage container. The present invention further provides medical devices that are capable of withstanding autoclave sterilization. (Function) Therefore, the medical soft vinyl chloride resin composition of the present invention contains
General formula () RCOOR' () (However, in the formula, R and R' are each a chain hydrocarbon group having 3 or more carbon atoms, and the sum of the carbon numbers of R and R' is 11 to 30.) The biggest feature is that it is made by adding a monocarboxylic acid ester represented by. Surprisingly, this monocarboxylic acid ester represented by the general formula () has the same effect of preventing red blood cell hemolysis as di-2-ethylhexyl phthalate, and on the other hand, unlike di-2-ethylhexyl phthalate, it inhibits platelet aggregation. It was found that no effect of suppressing the ability of the drug was observed. Furthermore, since the monocarboxylic acid ester represented by the general formula () has sufficient compatibility with vinyl chloride resins, if this monocarboxylic acid ester is blended, it will be possible to Even if a plasticizer, particularly a plasticizer with higher safety and low elution rate, is used, it is possible to obtain a soft vinyl chloride resin composition that has good preservability for red blood cells when it comes into contact with blood. That is, when the soft vinyl chloride resin composition comes into contact with blood, hemolysis of red blood cells is prevented by the action of the monocarboxylic acid ester represented by the general formula (), which is eluted from the resin composition. Since substances that inhibit platelet aggregation, such as di-2-ethylhexyl phthalate, are not eluted, it is highly safe for living organisms and has an excellent protective effect on red blood cells. Therefore, the medical soft vinyl chloride resin composition of the present invention is suitable as a material for medical devices, and molded products made using the material are suitable for
Due to its excellent safety, processability, flexibility, transparency, and heat resistance, it can be fully effective when used as a medical device, especially in the case of medical devices that come into contact with body fluids such as blood. , the effect is remarkable. Hereinafter, the present invention will be explained in more detail based on embodiments. The vinyl chloride resin used in the medical soft vinyl chloride resin composition according to the present invention includes:
In addition to vinyl chloride homopolymers, polyvinylidene chloride, copolymerization with other copolymerizable monomers containing vinyl chloride at 40% by weight or more, preferably 65% by weight or more, most preferably 75% by weight or more There are mergers, etc.
Its average degree of polymerization is 400~3000, preferably 600~
2700, most preferably 800-1700. Comonomers for vinyl chloride include vinylidene chloride, ethylene, propylene, vinyl acetate, vinyl bromide, vinyl fluoride, styrene, vinyltoluene,
Vinyl pyridine, acrylic acid, alkyl acrylates (e.g. methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, etc.), methacrylic acid, alkyl methacrylates (e.g. methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, etc.) ), acrylonitrile, methacrylonitrile, etc. In addition, vinyl chloride resin has styrene-
Acrylonitrile copolymer and styrene-methacrylonitrile copolymer can be blended. In addition, the plasticizer used in the medical soft vinyl chloride resin composition of the present invention is desired to be highly safe and more preferably have low elution properties.
For example, dinormal alkyl phthalates such as dinormal octyl phthalate, dinormal nonyl phthalate, dinylmaldecyl phthalate, dinormal undecyl phthalate, dilauryl phthalate, tri-2-ethylhexyl trimellitate,
Examples include trialkyl trimellitates such as tri-normal octyl trimellitate, tetraalkyl pyromellitates such as tetra-2-ethylhexyl pyromellitate, and particularly preferred are di-normal decyl phthalate and trioctyl trimellitate. . In the medical soft vinyl chloride resin composition of the present invention, these plasticizers are usually blended in an amount of 10 to 45% by weight, preferably 15 to 35 parts by weight, although this varies depending on the type of plasticizer. Plasticizer amount is 10
This is because if the amount is less than 45% by weight, the resulting composition will lack flexibility, while if it exceeds 45% by weight, there is a possibility that a bleed phenomenon will occur. Therefore, in the medical soft vinyl chloride composition of the present invention, the general formula () RCOOR' () (wherein R and R' each have 3 or more carbon atoms,
It is preferably a chain carbon hydrogen group of 3 to 22, most preferably 3 to 18, and the sum of the carbon numbers of R and R' is
11-30, preferably 11-21. ) is blended with a monocarboxylic acid ester. The monocarboxylic acid ester represented by the general formula () acts as a hemolysis inhibitor in the medical soft vinyl chloride resin composition of the present invention. That is, when blood comes into contact with a product made of the medical soft vinyl chloride resin composition of the present invention, the monocarboxylic acid ester represented by the general formula () eluted from the composition protects red blood cells. It is something that brings about an effect. In the monocarboxylic acid ester represented by the general formula (), the number of carbon atoms in R and R' is 3 or more because if the chain is a chain hydrocarbon chain with less than 3 carbon atoms, the compound may become toxic. This is because it is not appropriate to incorporate it into a medical resin composition. In addition, in the monocarboxylic acid ester represented by the general formula (), the sum of the carbon numbers of R and R' is set to 11 to 30 because the sum of the carbon numbers is 11 to 30.
If it is less than 30, it will not have the effect of preventing hemolysis, while if the sum of the carbon numbers exceeds 30, it will be incompatible with the vinyl chloride resin, making it difficult to uniformly disperse it in the resin composition. Further, in the monocarboxylic acid ester of the general formula (), it is more preferable that at least one of the chain hydrocarbon groups R and R' has a branched structure in order to increase the compatibility with the vinyl chloride resin and the effect of preventing hemolysis. . Furthermore, the chain hydrocarbon groups R and R' may be saturated or unsaturated chain hydrocarbon groups. Specifically, the monocarboxylic acid ester represented by the general formula () includes 2-ethylhexylbutyrate, 2-ethylhexylisobutyrate,
Isoheptyl valerate, 2-ethylhexyl valerate, isoheptyl pivalate, 2-ethylhexyl pivalate, isopentylhexanoate, isohexylhexanoate, 2-ethylhexylhexanoate, isobutyl-2-ethylhexanoate, Isopentyl-2-ethylhexanoate, 2-ethylhexyl-2-ethylhexanoate, isopropyldecanoate, isobutyldecanoate, 2-ethylhexyldecanoate, isopropyl laurate, isobutyl laurate, 2-ethylhexyl laurate , 2-
Ethylhexyl isolaurate, isopropyl myristate, isobutyl myristate, 2-ethylhexyl myristate, isopropyl palmitate, isobutyl palmitate, 2-ethylhexyl palmitate, isopropyl stearate,
Examples include, but are not limited to, isobutyl stearate, 2-ethylhexyl stearate, isopropyl isostearate, isobutyl isostearate, 2-ethylhexyl isostearate, isopropyl oleate, isobutyl oleate, 2-ethylhexyl oleate, etc. It's not like that. Preferred among these compounds are isopropyl isolaurate, isopropyl oleate, 2-ethylhexyl isostearate, and 2-ethylhexyl 2-ethylhexanoate, and most preferred is isopropyl isolaurate. The monocarboxylic acid ester represented by the above general formula () is blended in the medical soft vinyl chloride resin composition of the present invention in a proportion of 1 to 30% by weight, more preferably 3 to 25% by weight. . In other words, if the amount of the monocarboxylic acid ester represented by the general formula () is less than 1% by weight, the effect of suppressing hemolysis of red blood cells will not be sufficient, while if it exceeds 30% by weight, soft vinyl chloride This is because there is a risk of deteriorating the physical properties of the resin composition. Furthermore, the medical vinyl chloride resin composition of the present invention may contain epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil as stabilizers and auxiliary plasticizers, calcium and zinc as stabilizers. Metal soaps such as stearic acid, lauric acid, ricinoleic acid, naphthenic acid, etc., lubricants, antioxidants, etc. may be blended. The amount of epoxidized vegetable oil as a stabilizer and auxiliary plasticizer is as follows:
The amount is 3 to 10% by weight, more preferably 6 to 9% by weight, and the amount of metal soap added as a stabilizer is 0.05% by weight.
-3% by weight, more preferably 0.1-1.5% by weight. The medical vinyl chloride resin composition of the present invention may be molded by any of the methods used for conventional vinyl chloride resin compositions, such as calendar molding, extrusion molding, and plastisol molding. It can be molded, and high frequency fusion, heat fusion, ultrasonic fusion, etc. can be used as bonding methods. The medical device of the present invention is substantially composed of a soft vinyl chloride resin composition comprising a vinyl chloride resin, a plasticizer, and a monocarboxylic acid ester represented by the above general formula (). It has excellent physical properties such as safety, processability, flexibility, and heat resistance, and is particularly effective in inhibiting hemolysis of red blood cells. Therefore, the medical devices of the present invention preferably include medical devices that come into contact with blood or body fluids, such as blood storage containers such as blood bags, catheters, blood ring sets, and blood circuits. It also includes packaging containers and packaging containers for drugs such as tablets. Next, one embodiment of the medical device according to the present invention will be described with reference to the drawings, taking a blood bag as an example. That is, FIG. 1 shows a blood bag, and the blood collection bag 3 made of the above-mentioned soft vinyl chloride resin composition is equipped with a plurality of peel tab-equipped discharge ports 1 and a connecting discharge port 2. The blood collection bag 3 is heat-sealed by high frequency heating or other heating means, and the blood collection tube 6 made of the above-mentioned soft vinyl chloride resin composition is connected to the blood collection bag 3, which communicates with the internal space 5 of the blood collection bag 3. Further, a puncture needle 8 is attached to a needle base 7 provided at the tip of the blood collection tube 6, and a cap 9 is attached to this puncture needle 8. Further, the connecting outlet 2 of the blood collection bag 3 is provided with a connecting tube 17 connected by a connecting needle 16 at the tip, and this connecting tube 17 is provided with the outlet 10 with a peel tab via a branch pipe 15 as described above. The connection tube 13 made of the above-mentioned soft vinyl chloride-based resin composition is connected to the internal space 12 of the first child bag 14, which is also made of a soft vinyl chloride-based resin composition and has the circumferential portion 11 heat-sealed. Furthermore, these connecting tubes 17 and 13 are connected via a branch pipe 15 to a second tube having a peel tab equipped outlet 18 and made of the above-mentioned soft vinyl chloride resin composition and having a peripheral edge 19 similarly heat-sealed. The connecting tube 22 made of the above-mentioned soft vinyl chloride resin composition is connected to the internal space 20 of the bag 23 . This triple blood bag is capable of separating the components of blood collected in a closed system. That is, first, a predetermined amount of blood is collected into the blood collection bag 3 through the blood collection tube 6 from the puncture needle 8 inserted into the blood donor's vein. After blood collection is completed, the blood collection bag 3 is centrifuged to separate the blood into an upper layer of platelet-rich plasma and a lower layer of blood cells. Next, the platelet-rich plasma in the upper layer of the blood collection bag 3 is pushed out and transferred to the first child bag 14 through the connecting tubes 17 and 13. The first child bag 14 containing the platelet-rich plasma is further centrifuged to separate the platelet concentrate in the upper layer and the platelet-poor plasma in the lower layer. It is pushed out and transferred through the connecting tubes 13 and 22 to the second child bag 23. Blood collected in this way is separated into components by centrifugation and stored in each blood bag. Even if the blood components come into contact with the blood bags and tubes for a long time, each blood bag and tube is The soft vinyl chloride resin composition of the present invention, which constitutes the composition, is excellent in protecting and hardening red blood cells, and does not inhibit the aggregation ability of platelets, thereby enabling safe and effective blood circulation. The above explanation uses blood bags as an example, but other body fluid storage containers, catheters, blood ring sets,
Medical devices such as blood circuits, packaging containers for medical devices, packaging containers for drugs such as tablets, etc. are similarly suitably constructed from the above-mentioned soft vinyl chloride resin composition. The medical device according to the present invention is sterilized before use, and ethylene oxide sterilization, autoclave sterilization, etc. are used as the sterilization method, and autoclave sterilization is preferably used. In autoclave sterilization, medical devices are usually treated at about 121°C for about 60 minutes, but as described above, the medical devices of the present invention have sufficient heat resistance to withstand such autoclave sterilization conditions. . (Examples) Hereinafter, the present invention will be explained in more detail based on Examples. Examples 1 to 3 After roll kneading a soft vinyl chloride resin composition having the composition shown in Table 1 at 150°C for 5 minutes,
It was molded into a 0.4 mm thick sheet using a press molding machine. A 20 ml mini blood bag was prepared by overlapping two of the obtained sheets and high-frequency sealing at a predetermined portion. The bag has a hematocrit value of approx.
Concentrated red blood cell fluid with human CPD adjusted to 70% (hereinafter referred to as
It is called CRC. ) Approximately 20 ml was dispensed and stored at 4°C for 4 weeks. Then, the plasma hemoglobin concentration was
TMB method (Clinical Chemistry 23 749~
(1977) [Clin.Chem. 23 749-(1977)]). In addition, to determine the concentration of the eluate in the CRC, remove 0.5 ml of the CRC after static storage, add 5 ml of isopropyl alcohol and 5 ml of diethyl ether, stir, centrifuge at 1500 x g for 10 minutes, and evaporate and transfer the supernatant. This was measured by dissolving it in 1 ml of acetonitrile and analyzing it with a high performance liquid chromatograph. The results are shown in Table 2. Comparative Examples 1 to 3 Mini blood bags similar to those in Example 1 were prepared using soft vinyl chloride resin compositions having the compositions shown in Table 1, and changes in plasma hemoglobin concentration and eluate concentration were examined. The results are shown in Table 2.

【table】

[Table] As is clear from the results shown in Table 2, when the soft vinyl chloride resin composition according to the present invention was used (Examples 1 to 3), as a plasticizer,
Compared to the case where almost nothing elutes into the blood using DnDP (Comparative Example 2), the elution is suppressed to a low level, and the value is relatively close to that when DOP is used as a plasticizer (Comparative Example 1). Ta. Reference Experiment A platelet function recovery experiment was conducted using the following procedure. First, a solution of 20,000 ppm of isopropyl isolaurate dissolved in methanol (Reference example 1), 2-ethylhexyl isostearate in methanol
A solution of 20,000 ppm dissolved in methanol (Reference Example 2), A solution of 20,000 ppm of 2-ethylhexyl-2-ethylhexanoate dissolved in methanol (Reference Example 3), Di-2-ethylhexyl phthalate in methanol
A solution in which 20,000 ppm of di-normal decyl phthalate was dissolved (Control Example 1), a solution in which 20,000 ppm of di-normaldecyl phthalate was dissolved in methanol (Control Example 2), and methanol to which nothing was added (blank) were prepared. Each of these solutions was added to human platelet-poor plasma at a volume of 1/100, 2 ml of this platelet-poor plasma was added to 1 ml of human platelet-rich plasma, and Tyrode's solution (1 μM PEG ₁ 4×10 ^-3 units/ml, including apyrase and 3.5 mg/ml BSA).
Incubate for 90 minutes at 37°C. After this, the platelets are washed and (Regland et al., European Journal of Biochemistry 142, 465
(1984) [Legrand et al., Eur.J.Biochem.142,
465 (1984]), apyrase 2 μg, protein/ml
Add Tyrode/BSA solution (0.2mM
_CaCl2 , 1mM _MgCl2 , 5mM HEPES, 3.5
Resuspend in Tyrode's solution (PH 7.35) containing mg/ml BSA and 50 μM in the presence of 0.2 mg/ml fibrinogen.
The maximum aggregation ability for ADP and 10 μg/ml collagen was measured using an Agricorder (manufactured by Kyoto Daiichi Kagaku Co., Ltd.). The results are shown in Table 3.

[Table] As shown in Table 3, di-2-ethylhexyl phthalate has an inhibitory effect on recovery of platelet aggregation ability. This suggests that di-2-ethylhexyl phthalate may inhibit platelet function when it enters the body, and that it is not appropriate to incorporate it into medical soft vinyl chloride resin compositions. It shows. On the other hand, isopropyl isolaurate, 2-ethylhexyl isostearate, 2-ethylhexyl-ethylhexanoate, and di-normaldecyl phthalate have no such inhibitory effect and are considered to be safer substances. This indicates that the soft vinyl chloride resin composition according to the present invention has little effect on platelets. (Effects of the Invention) As described above, the present invention provides a medical soft vinyl chloride resin comprising a vinyl chloride resin, a plasticizer, and a monocarboxylic acid ester represented by the general formula (). The composition is excellent in safety, and the conventional soft vinyl chloride resin composition using di-2-ethylhexyl phthalate as a plasticizer has the same effect of inhibiting hemolysis of red blood cells, as well as high moldability, flexibility, transparency, and It has various physical properties such as heat resistance, and can be molded by any of the conventional molding methods such as calendar molding, extrusion molding, and plastisol molding. It is suitable for use as a material for medical equipment, especially for medical equipment that comes into contact with blood, such as blood storage containers, because it has a thermal melting point. Furthermore, when 10 to 45% by weight of a plasticizer and 1 to 30% by weight of a monocarboxylic acid ester represented by the general formula () are blended in the medical soft vinyl chloride resin composition of the present invention,
More preferably, the compound represented by the general formula () in which at least one of R or R' in has a branched structure is isopropyl isolaurate, isopropyl oleate, 2-ethylhexyl isostearate, or 2-ethylhexyl- When it is 2-ethylhexanoate,
In addition, the plasticizer is of low elubility, preferably one selected from the group consisting of trialkyl trimellitate, di-normal alkyl phthalate and tetraalkyl pyromellitate, more preferably di-normaldecyl phthalate or trioctyl trimellitate. In the case of tate, safety, hemolysis inhibiting effect, and other physical properties are even more excellent. The present invention also provides a medical device characterized in that it is substantially composed of a soft vinyl chloride resin composition comprising a vinyl chloride resin, a plasticizer, and a monocarboxylic acid ester represented by the general formula (). Therefore, it is highly safe and exhibits an effect of inhibiting hemolysis on red blood cells, and it is especially useful when medical devices can come into contact with blood, such as blood storage containers, by denaturing blood components. It can be said that it is an extremely excellent medical device with no risk of causing damage. Furthermore, in the medical device of the present invention, the soft vinyl chloride resin composition that substantially constitutes the medical device contains 10 to 45% by weight of a plasticizer and 1 to 30% by weight of a monocarboxylic acid ester represented by the general formula ().
or the general formula ()
At least one of R or R' in has a branched configuration. More preferably, when the compound represented by the general formula () is isopropyl isolaurate, isopropyl oleate, 2-ethylhexyl isostearate or 2-ethylhexyl-ethylhexanoate, in addition, the plasticizer is a low-solubility one; Preferably selected from the group consisting of trialkyl trimellitate, dinormal alkyl phthalate and tetraalkyl pyromellitate, more preferably dinormaldecyl phthanate or trioctyl trimellitate for safety and hemolysis. The result is a medical device that is superior in suppressive action and other aspects such as heat resistance, transparency, and flexibility.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the medical device of the present invention. 3...Blood collection bag, 6...Blood collection tube, 1
3, 17, 22...Connection tube, 14...1st
Child Batsugu, 23...Second child Batsugu.

Claims (1)

[Scope of Claims] 1. Vinyl chloride resin, plasticizer, and general formula () RCOOR' () (However, in the formula, R and R' are each a chain hydrocarbon group having 3 or more carbon atoms, and R and R A soft vinyl chloride resin composition for medical use, comprising a monocarboxylic acid ester represented by the following formula: 2. The medical soft vinyl chloride resin composition according to claim 1, which contains 10 to 45% by weight of a plasticizer and 1 to 30% by weight of a monocarboxylic acid ester represented by the general formula (). . 3. The medical soft vinyl chloride resin composition according to claim 1 or 2, wherein at least one of R or R' in the general formula () has a branched structure. 4 Claims 1 to 3, wherein the compound represented by the general formula () is isopropyl isolaurate, isopropyl oleate, 2-ethylhexyl isostearate, or 2-ethylhexyl-2-ethylhexanoate. The medical soft vinyl chloride resin composition according to any one of the above. 5. The medical soft vinyl chloride resin composition according to any one of claims 1 to 4, wherein the plasticizer has low elution properties. 6. The medical soft material according to any one of claims 1 to 5, wherein the plasticizer is selected from the group consisting of trialkyl trimellitate, dinormal alkyl phthalate, and tetraalkyl pyromellitate. Vinyl chloride resin composition. 7. The medical soft vinyl chloride resin composition according to claim 6, wherein the plasticizer is di-normaldecyl phthalate. 8. The medical soft vinyl chloride resin composition according to claim 6, wherein the plasticizer is trioctyl trimellitate. 9 Vinyl chloride resin, plasticizer, and general formula () RCOOR' () (However, in the formula, R and R' are each a chain hydrocarbon group having 3 or more carbon atoms, and the number of carbon atoms between R and R' is A medical device characterized in that it is substantially composed of a soft vinyl chloride resin composition comprising a monocarboxylic acid ester having a sum of 11 to 30. 10 10 to 45% by weight of plasticizer and 1 to 30% by weight of monocarboxylic acid ester represented by general formula ()
10. The medical device according to claim 9, wherein the medical device is substantially composed of a soft vinyl chloride resin composition comprising: 11. The medical device according to claim 9 or 10, wherein at least one of R or R' in general formula () has a branched structure. 12 Claims 9 to 11, wherein the compound represented by the general formula () is isopropyl isolaurate, isopropyl oleate, 2-ethylhexyl isostearate or 2-ethylhexyl-2-ethylhexanoate. Medical equipment described in any of the above. 13. The medical device according to any one of claims 9 to 12, wherein the plasticizer has low elution properties. 14 The plasticizer is trialkyl trimellitate,
The medical device according to any one of claims 9 to 13, which is selected from the group consisting of di-normal alkyl phthalates and tetraalkyl pyromellitates. 15. The medical device according to claim 14, wherein the plasticizer is di-normaldecyl phthalate. 16. The medical device according to claim 14, wherein the plasticizer is trioctyl trimellitate. 17. The medical device according to any one of claims 9 to 16, which is a blood storage container. 18. The medical device according to any one of claims 9 to 17, which can withstand autoclave sterilization.