JP5291294B2 - Rigid medical vinyl chloride resin composition and rigid medical parts using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hard vinyl chloride-based resin composition for medical use excellent in sterilization treatment by radioactive ray irradiation, especially, with remarkably reduced in the discoloration even when treated by &gamma;-ray irradiation, and excellent in radioactive ray resistance, hardness and elutability, and hard parts for medical use produced by molding the same. <P>SOLUTION: The hard vinyl chloride-based resin composition for medical use comprises 100 pts.wt. of a vinyl chloride-based resin and 1-15 pts.wt. of one or more plasticizers selected from cyclohexane dicarboxylate-based plasticizers and alkylsulfonic acid-based plasticizers, and has &ge;35&deg; Rockwell hardness defined by JIS K7202. The hard medical parts are molded articles prepared by molding the resin composition. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  TECHNICAL FIELD The present invention relates to a hard medical vinyl chloride resin composition having excellent discoloration stability with respect to a radiation sterilization method using γ rays or electron beams, and a hard medical component using the same.

  Medical parts must be (1) not harmful to the human body due to elution of heavy metals, etc. (2) easy to use in the medical field, (3) sterility is maintained until use, (4) It is necessary to be able to confirm the state of the internal liquid.

  Soft vinyl chloride resin composition is used as a material that satisfies these performances, and soft vinyl chloride resin composition consisting of vinyl chloride resin and plasticizer for soft medical parts such as blood bags, infusion bags, dialysis circuit tubes, etc. Resin compositions are preferably used.

  In addition, hard materials such as polycarbonate and polyolefin are used in various parts connected to these soft medical parts, for example, hard medical parts such as a syringe, a tube connecting member, a branch valve, and a speed adjusting part. .

  Traditionally, these medical components have been sterilized primarily using ethylene oxide gas (EOG) because of the need to be highly sterilized. However, since the residual EOG gas after sterilization has carcinogenicity, it has shifted to high-pressure steam sterilization instead of EOG gas sterilization from the viewpoint of safety. In the sterilization methods such as EOG sterilization and high-pressure steam sterilization, it is necessary to sterilize the packaged product individually for each bag, and there is a problem that sterilization work takes a lot of time and effort. In order to speed up the sterilization work, after 1980, sterilization after packaging is possible, and the conversion to cobalt 60-γ-ray sterilization (hereinafter referred to as γ-ray sterilization) and electron beam sterilization, which leads to cost reduction, has been made. It is progressing rapidly. Among radiation sterilization, electron beam sterilization has the advantage of being able to sterilize a large number of parts in a short time, but the problem is that the permeability is small, sterilization tends to be uneven, and lottery is likely to occur during sterilization. There is. On the other hand, γ-ray sterilization has the advantage that the sterilization is performed uniformly because of the long irradiation time, but there is a problem that the color change of the parts is remarkable.

  These color change due to radiation sterilization may cause a medical accident such as a component error because the color change makes it impossible to identify the color tone of the medical component. Therefore, a material that changes color due to radiation sterilization cannot be used as a medical part.

  As described above, color change due to material deterioration of the hard medical component is a serious technical problem in this industry, and various efforts have been made to solve this problem.

  The soft vinyl chloride resin composition can solve these discoloration problems, and is currently suitably used as a material excellent in radiation resistance. However, the hard vinyl chloride resin composition has not solved the problem of discoloration, and a polycarbonate resin, an olefin resin, or the like having relatively good γ-ray resistance is used for hard medical parts.

  Polycarbonate resins are relatively stable to gamma rays and are becoming mainstream in gamma ray sterilization applications. However, the chemical resistance is inferior, such as cracking due to the action of an anesthetic, the effects of residual monomers of bisphenol A are concerned, the molding processability is inferior to that of the vinyl chloride resin composition, and the majority of the circuit is occupied. There are drawbacks such as poor adhesion to (mainly soft) polyvinyl chloride.

  There is also a proposal to use a resin such as α-olefin for solving these problems (Patent Document 1). However, the above method has problems such as inferior kink resistance (folding resistance), and thus has a long-term safety record in the market, excellent in moldability, chemical resistance, folding resistance, and the like. There has been a strong demand for a hard vinyl chloride resin composition having excellent radiation resistance and less discoloration.

In order to meet such a demand in the medical field, for example, as in Patent Documents 2 to 3, a proposal to suppress coloring by adding a stabilizer and an epoxidized vegetable oil, for example, as in Patent Documents 4 to 5 Although methods for adding alkyl mercaptans and alkyl esters of adipic acid have been proposed, the electron beam sterilization method shows some improvement effect, but the effect on the γ-ray sterilization method is insufficient, and further improvement is possible. It is an urgent issue.
JP 2003-3026 A JP-A-8-73619 JP-A-8-176383 Japanese Patent Laid-Open No. 7-102142 Japanese National Patent Publication No. 11-510854

  In order to solve the above-mentioned conventional problems, the present invention remarkably reduces discoloration even after irradiation irradiation sterilization treatment, particularly γ-ray irradiation sterilization, and has excellent radiation resistance and hardness and dissolution properties. Provided are a vinyl chloride resin composition and a rigid medical part molded from the composition.

  The vinyl chloride resin composition for rigid medical use of the present invention comprises one or more plasticizers selected from cyclohexane dicarboxylate plasticizer and alkylsulfonic acid plasticizer with respect to 100 parts by weight of vinyl chloride resin. A composition comprising 1 part by weight or more and 15 parts by weight or less, wherein the Rockwell hardness defined by JIS K7202 is a hard part of 35 ° or more.

  The hard medical component of the present invention is formed by molding the hard medical vinyl chloride resin composition.

  The hard medical vinyl chloride resin composition of the present invention has little discoloration upon radiation sterilization (electron beam sterilization, γ-ray sterilization), has excellent elution properties, and is a hard medical part commercialized with the composition. Is a hard medical component that has little discoloration when sterilized by radiation (electron beam sterilization, γ-ray sterilization) and has excellent elution properties.

  The present inventors have studied the relationship between radiation resistance (particularly γ-ray resistance) and a compounding agent, and are a hard composition comprising a vinyl chloride resin and a specific plasticizer as essential components, The present invention has been completed by finding that a hard medical composition having an extremely excellent balance between radiation resistance and dissolution can be obtained by selecting the thickness within a specific range.

  In the present invention, 1 part by weight or more and 15 parts by weight or less of one or more kinds of plasticizers selected from cyclohexane dicarboxylate plasticizer and alkylsulfonic acid plasticizer are blended with 100 parts by weight of vinyl chloride resin. And a hard medical vinyl chloride resin composition having a Rockwell hardness defined by JIS K7202 of 35 ° or more, and a hard medical part molded from this resin composition. This provides a hard medical vinyl chloride resin composition with an excellent balance between radiation resistance and dissolution, and there is no discoloration during sterilization, elution, surface, kink, chemical resistance, etc. Can provide excellent hard medical parts.

  In the above, if the Rockwell hardness defined by JIS K7202 is 35 ° or more, it means hard.

  Among the plasticizers, cyclohexanedicarboxylate-based plasticizer and / or alkylsulfonic acid-based plasticizer has an extremely excellent balance between elution and γ-ray resistance, and particularly 0.2 to 7 parts by weight of a silane compound in the composition. By blending, a rigid medical vinyl chloride resin composition and a rigid medical component having extremely excellent resistance to discoloration during sterilization are provided.

  As the silane compound, an alkoxysilane compound is particularly preferable, and particularly excellent hard medical treatment by blending one or more silane compounds selected from a monoalkoxysilane compound, a dialkoxysilane compound, a trialkoxysilane compound, and a tetraalkoxysilane compound. It can be used as a vinyl chloride resin composition. In particular, when 3-methacryloxypropyltriethoxysilane or vinyltriethoxysilane is selected as the silane compound, a particularly excellent hard medical vinyl chloride resin composition is obtained as a medical composition, and discoloration due to γ-ray sterilization. It is possible to obtain a hard medical part having good elution properties.

  The vinyl chloride resin used in the present invention is a conventionally known vinyl chloride resin, for example, a vinyl chloride resin that is a vinyl chloride homopolymer, and other monomers that can be copolymerized with vinyl chloride. Polymerized vinyl chloride copolymer resins such as vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl stearate copolymer resins such as vinyl chloride and alkyl vinyl ester copolymer resins, vinyl chloride-ethylene copolymer resins Copolymer resins of vinyl chloride and olefins, such as vinyl chloride-propylene copolymer resins, copolymer resins of vinyl chloride and (meth) acrylic acid or esters thereof, copolymer resins of vinyl chloride and fumaric acid esters, Copolymer resins of vinyl chloride and alkyl vinyl ether can also be used, and these may be used alone or in combination of two or more. It may be used Te Align.

  Although the average degree of polymerization of the vinyl chloride resin used in the present invention is not particularly limited, the average degree of polymerization is preferably in the range of 400 to 1300, more preferably in the range of 650 to 1100, from the balance between processability and performance.

  The plasticizer used in the present invention is 1 to 15 parts by weight or less based on 100 parts by weight of the vinyl chloride resin of one or more plasticizers selected from cyclohexane dicarboxylate plasticizers and alkylsulfonic acid plasticizers. In the range of. If it is this range, the hardness requested | required of a hard medical component can be ensured. In consideration of the balance with moldability, the range of 8 to 15 parts by weight is more preferable.

  Among these, a cyclohexanedicarboxylate plasticizer is particularly preferable from the viewpoint of a balance between γ-ray resistance and elution. Further, by using this as the main plasticizer and other plasticizers as subordinate plasticizers, the balance of radiation resistance, hardness and elution can be made in an excellent range. Here, “main” means 50% by weight or more.

  Examples of the alkyl sulfonic acid plasticizer that can be used in the present invention include alkyl sulfonic acid phenyl ester and N, n-butylbenzenesulfonamide. Of these, alkylsulfonic acid phenyl ester is preferred.

  Examples of the cyclohexanedicarboxylate plasticizer that can be used in the present invention include diisononylcyclohexanedicarboxylate, dimethylcyclohexanedicarboxylate, diethylcyclohexanedicarboxylate, and di-2-ethylhexylcyclohexanedicarboxylate. Of these, diisononylcyclohexanedicarboxylate and di-2-ethylhexylcyclohexanedicarboxylate are preferable.

  In the present invention, by using a silane compound in combination, the balance between radiation resistance (γ-ray resistance) and elution can be further improved, and alkoxysilane compounds, chlorosilane compounds, acetoxysilane compounds, organosilanes. Silane compounds such as compounds can be used. The addition amount of the silane compound is preferably 0.2 to 7 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. If the amount of silane compound added is in the range of 0.2 to 7 parts by weight, select the region where the balance between the effect of improving radiation resistance (γ-ray resistance) and Rockwell hardness, dissolution property, blending cost, etc. it can. A more preferable addition amount of the silane compound is 1.5 to 3.5 parts by weight with respect to 100 parts by weight of the vinyl chloride resin.

  In the present invention, among these silane compounds, one or more silane compounds selected from monoalkoxysilane compounds, dialkoxysilane compounds, trialkoxysilane compounds, and tetraalkoxysilane compounds are particularly preferable.

  Examples of the monoalkoxysilane compound that can be used in the present invention include trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, and triethylethoxysilane.

  Examples of dialkoxysilane compounds that can be used in the present invention include methyldimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylaminoethoxypropyldialkoxysilane, and N (β-aminoethyl). Examples include -γ-aminopropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, and γ-methacryloxypropylmethyldimethoxysilane.

  Examples of trialkoxysilane compounds that can be used in the present invention include methyltrimethoxysilane, methyltriethoxysilane, hexyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and γ- Chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N (phenyl) -γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltri Methoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, γ- (polyethyleneamino) propyltrimethoxysilane, γ-urea Examples include idpropyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, vinyltrisvinyltris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane Is done.

Examples of tetraalkoxysilane compounds that can be used in the present invention include tetramethoxysilane and tetraethoxysilane. In particular, a trialkoxysilane compound is preferred from the balance between γ-ray resistance and other characteristics, cost, etc., and 3-methacryloxypropyltriethoxysilane and vinyltriethoxysilane are particularly preferred from the viewpoint of excellent elution. Is particularly preferred.
In the present invention, these silane compounds can be used in combination of two or more, and are not particularly limited.

  The Rockwell hardness (R scale) defined in the present invention is a hardness defined in JIS K7202, and is a value measured at a temperature of 23 ° C. in accordance with the JIS. Is used, a composition having a hardness of 35 ° or more is used. In particular, the hardness is preferably in the range of 60 ° or more.

  When a composition having a hardness of 35 ° or more is applied to a hard medical part, the part does not bend and the liquid flow of the contents is not hindered. Good characteristics are also maintained.

  The Rockwell hardness is preferably maintained at 35 ° or more both before and after γ-ray irradiation. The change in hardness (Δ hardness) is preferably not so much changed, and is not particularly limited, but is particularly preferably 20 ° or less.

  The difference between the YI values before and after γ-ray irradiation (ΔYI) used for the evaluation of radiation resistance in the present invention will be described in more detail in the section “Evaluation of radiation resistance” in the examples. The difference between the YI value before γ-ray irradiation and the YI value after γ-ray irradiation is obtained, and is defined as a parameter for evaluating the degree of discoloration.

  ΔYI is preferably as small as possible, and is preferably 20 or less for use in hard medical applications. If it is 20 or less, the discoloration at the time of sterilization of a medical component can be suppressed to an allowable range, and it can be suitably used for the above-mentioned use.

  In the present invention, a conventionally known liquid compounding agent can be used as necessary as a compounding agent, but the amount of the liquid compounding agent used is a vinyl chloride resin 100 in consideration of the Rockwell hardness limitation. 15 parts by weight or less is preferable with respect to parts by weight. If it exceeds 15 parts by weight, it will be difficult to maintain the Rockwell hardness at 35 ° or more, and the function as a hard medical part may be impaired. Typical examples of the liquid compounding agent include a heat stabilizer and a stabilizing aid, and conventionally known liquid compounding agents can be appropriately selected and used.

  A conventionally well-known heat stabilizer can be suitably used for the hard medical vinyl chloride resin composition of the present invention. The heat stabilizer is used for the purpose of suppressing coloration when heat is applied, such as during molding, and various stabilizers can be appropriately selected.

  As the stabilizer that can be added to the present invention, known stabilizers that have been conventionally used in medical applications can be used, and particularly preferred are organic tin stabilizers, such as methyltin mercapto and butyltin. Tin mercapto stabilizers such as mercapto and octyl tin mercapto, tin maleate stabilizers such as octyl tin maleate and the like can be suitably used. In particular, an octyl tin mercapto-based stabilizer is particularly preferable from the viewpoint that the effect of suppressing discoloration during radiation sterilization is remarkable.

  In addition, from the viewpoint of safety and hygiene, metal soaps such as zinc stearate and calcium stearate that are conventionally used for medical applications can also be suitably used. Furthermore, from the viewpoint of various performance balances as a hard medical composition, a composition comprising a methyltin mercapto stabilizer, zinc stearate and calcium stearate is particularly useful.

  The addition amount of these stabilizers is particularly preferably set in the range of 2 to 6 parts by weight with respect to 100 parts by weight of the vinyl chloride resin, and within this range, radiation resistance, thermal stability and tin elution, Cost and other performance can be maintained in the optimum region. When the addition amount exceeds 6 parts by weight, in the extraction test applied to the medical composition, the elution amount of tin is slightly increased and tends to exceed the preferable range. The range of 2 to 4 parts by weight is particularly preferred from the balance of radiation resistance, thermal stability and tin elution.

  As the stabilizing aid, conventionally known aids can be used, for example, phosphites such as dioctyl phosphate, diphenylnonylphenyl phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite. , Phosphates such as triallyl phosphate, β-diketones such as stearoylbenzoylmethane and dibenzoylmethane can be used. Among these, β-diketones such as stearoylbenzoylmethane and dibenzoylmethane are suitable, and are suitable for suppressing discoloration due to γ-ray resistance.

  In the present invention, compounding agents such as lubricants, colorants, ultraviolet absorbers, antioxidants and the like conventionally used in medical applications can be appropriately used within a known range as necessary.

  When manufacturing a hard medical part using the vinyl chloride resin composition for hard medical use of the present invention, there is no special limitation and it can be manufactured by a conventionally known method. For example, a polyvinyl chloride resin composition blended in a predetermined composition is kneaded with a roll, a banbury, an extruder, etc. to be pelletized, and then the obtained pellet is converted into various molding machines such as an extruder, an injection molding machine. It can be molded with a calendar molding machine or the like.

  As a blending method, a conventionally known method can be applied. For example, each component is mixed by hot blending or cold blending using a Henschel mixer, a supermixer, or the like. As a kneading method, conventionally known methods can be applied. For example, pellets can be obtained using a single screw extruder, a different direction twin screw extruder, a same direction twin screw extruder, a pressure kneader, a planetary gear multi-screw extruder, or the like. create. As the pelletizing conditions, it is preferable to use a kneader in which the cylinder temperature is set to 100 to 160 ° C. and the die temperature is set to 130 to 170 ° C.

  Furthermore, when secondary-molding the pellets, it is preferable to use a molding machine in which the cylinder temperature and the die temperature are set to 130 to 200 ° C.

In the molding of the hard medical parts according to the present invention, since there are many parts having fine and complicated shapes, the molding process using an injection molding machine has been applied conventionally. Since the resin-based resin composition is also excellent in injection moldability and the like, it can be particularly suitably used for injection molding and is very useful practically.
In the conventional compounding system, dimensional changes were easily caused by sterilization after injection molding. The resin composition of the present invention is superior in dimensional stability before and after radiation sterilization compared to conventional products.

  The medical parts in the present invention are defined in Article 2, Paragraph 4 of the Pharmaceutical Affairs Law and Article 1 of the Pharmaceutical Affairs Law Enforcement Ordinance, and among the machinery and equipment defined in Attached Table 1, in particular, 17, 18, 19, The connection member of a mechanical instrument defined by 20, 47, 48, 51, 56 etc., a valve, etc. are shown. Specifically, blood bags, infusion bags, waste solution bags, infusion sets, blood transfusion sets, component blood collection systems, leukocyte removal filters, blood circuit systems, artificial dialysis circuits, cardiopulmonary systems, winged needles, etc. , Parts used as valves and side caps, vacuum blood collection tubes, syringes and the like. The rigid medical vinyl chloride resin composition of the present invention is particularly preferably used in blood bags, infusion bags, infusion sets, transfusion sets, blood circuit system connection parts, valves, and side caps.

  Since these parts have various shapes and complicated shapes, most of them are manufactured by injection molding. For example, injection molding is suitably applied to T-shaped tubes, Y-shaped tubes, side caps, and the like. Extrusion molding is suitably applied to relatively long connecting pipes, hard chamber tubes, and the like.

In addition, the hard medical vinyl chloride resin composition according to the present invention is superior in the initial colorability of the resin as compared with the olefin resin and the polycarbonate resin, and at the time of injection molding, the molding temperature can be suppressed to be low in productivity. Excellent and excellent adhesion to PVC. The injection molding conditions of the rigid medical vinyl chloride resin composition according to the present invention are particularly preferably injection molding at a cylinder temperature of 170 ° C. to 190 ° C. and an injection pressure of 800 to 1200 kg / cm ² .

  The parts made of polyvinyl chloride resin for rigid medical use according to the present invention can be made into medical parts combining the same materials with soft parts that have been used for medical applications in the past, and it is possible to manufacture circuits and the like using only PVC-based materials. Yes, it is possible to avoid problems such as poor adhesion that occur in combination with other materials, and to contribute to reducing medical troubles such as part detachment.

  Next, aspects of the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited to these examples.

The raw materials and evaluation methods used in the examples and comparative examples are shown below.
1. Description of materials used (1) Resin component Vinyl chloride resin: Kane vinyl S1007: Kaneka Corporation (2) Silane compound 3-Methacryloxypropyltrimethoxysilane: Shin-Etsu Chemical Co., Ltd. Tetraethoxysilane: Shin-Etsu Chemical Co., Ltd. ) Vinyltriethoxysilane: Toshiba Silicone Co., Ltd.
(3) Plasticizer component Phthalate ester plasticizer: ADEKA Corporation Trimellitic acid di-2-ethylhexyl: ADEKA Corporation Epoxidized soybean oil: ADEKA Corporation Diisononylcyclohexane dicarboxylate: Corporation BASF alkyl sulfonic acid phenyl ester: ADEKA (mixed alkyl having 10 to 20 carbon atoms)
(4) Stabilizer, Stabilizing Auxiliary Component Organotin Stabilizer: Dioctyltin Dimer Captide Organotin Stabilizer: Dioctyltin Maleate Stabilizing Aid: Tris (nonylphenyl) phosphite (5) Lubricant Component Lubricant: Polyethylene Wax
2. Evaluation of radiation resistance Regarding the radiation resistance, first, a computer color matching system [Yoshinichi Seisakusho] in which the yellowness (YI value) before irradiation is compliant with JISK7105 is applied to a sheet-like test sample prepared by roll / press processing. Manufactured by Chemical Industries Co., Ltd.]. The test sample was then irradiated with 25 KGy of gamma rays. Since the colored yellowing of the test sample after irradiation progressed gradually, the sample after irradiation was allowed to stand for 3 days under constant temperature and humidity conditions (23 ° C., 50% relative humidity) until stabilization. Thereafter, the YI value of the post-irradiation sample was measured with the above-mentioned measuring instrument, and the post-irradiation YI value was determined.

  The yellowing degree (ΔYI value) defined by the following formula was calculated as an evaluation index for the degree of discoloration, and a ΔYI value of 20 or less was determined as the acceptable range.

ΔYI value = (YI after irradiation) − (YI before irradiation)
3. Hardness measurement (1) Rockwell hardness Based on JIS K7202 and JIS K7202, using a Rockwell hardness tester, the test temperature is 23 ° C, and the data immediately after the measurement is adopted. For the test piece, a sheet test sample having a thickness of 6 mm was prepared by roll / press processing, and kept in a constant temperature and humidity chamber of 23 ° C. * 50% RH for one day and night, and then subjected to measurement.

Considering the hardness required for hard medical parts, the Rockwell hardness before γ-ray irradiation is 35 ° or more, and if the hardness changes greatly due to irradiation, the performance as a part becomes abnormal. In order to connect, the acceptance range of hardness change ((DELTA) hardness) was 20 degrees or less.
4). Dissolution The ultraviolet absorption spectrum was measured in accordance with the vinyl chloride resin compound I standard of the medical plastic test standard established by the Japan Medical Equipment Association. An approximately 2 mm thick sheet prepared by roll / press processing was cut into approximately 3 mm squares to obtain test pellets. A predetermined amount of the pellet was precisely weighed, put into a hard glass container, and extracted by heating at 121 ° C. for 1 hour. A predetermined amount of the extract was precisely weighed to prepare a test solution. A difference ΔUV in absorbance between the test solution and the blank test solution at a wavelength of 220 to 350 nm was measured. The range of absorbance difference was classified into 4 levels and evaluated by A to D. Evaluation criteria were as follows, and less than 0.10 was considered acceptable.
A: Pass: Absorbance difference: less than 0.04 B: Pass: Absorbance difference: 0.04 to less than 0.07 C: Pass: Absorbance difference: 0.07 to less than 0.10 D: Fail: Absorbance difference : 0.10 or more (Examples 1 to 4, Comparative Examples 1 to 7)
Based on the formulation of Table 1, the plasticizer addition effect in the hard compounding system was examined. Each component was weighed, all the components were hand-mixed together, and this blend was put into a two roll controlled at a surface temperature of 160 ° C. and kneaded for 5 minutes. The obtained roll sheet was cut into a predetermined size, and a sheet having a predetermined thickness was prepared with a press molding machine. The pressing conditions were 170 ° C preheating for 2 minutes, heating for 2 minutes, and then a cooling press for 5 minutes. The obtained sheet was subjected to various measurements such as radiation resistance.

  Comparative Examples 1 and 2 are blended systems using epoxy plasticizers that have been proposed as conventional hard medical vinyl chloride resin compositions, but Comparative Example 1 has a lasting pass range, ΔYI is rejected, and in Comparative Example 2, ΔYI is acceptable and the elution property is barely acceptable, but the hardness is unacceptable. Comparative Examples 3 to 5 are blending systems in which DOP or TOTM, which are general plasticizers used in soft medical parts, are each 10 parts by weight, or no plasticizer (unplasticized), but the ΔYI value is It was out of the hard application range and was rejected.

  Examples 1 and 2 use diisononyl cyclohexyl dicarboxylate, and Examples 3 and 4 are blended systems using alkyl sulfonic acid phenyl ester, but also have excellent dissolution properties and excellent γ-ray resistance. Rockwell hardness also has performance as a medical composition. Among these, the diisononyl cyclohexyl dicarboxylate used in Examples 1 and 2 has an excellent dissolution property and is found to be excellent as a medical composition.

 Comparative Examples 6 and 7 are blended systems in which a large amount of diisononyl cyclohexyl dicarboxylate or alkylsulfonic acid phenyl ester is added. When 19 parts by weight or more is added, Rockwell hardness is required for the hard composition. The range could not be maintained and it was rejected.

  From the above experimental results, it can be seen that the plasticizer amount is less than 19 parts by weight in order to have the Rockwell hardness required for hard medical applications, and among these plasticizers, diisononyl cyclohexyl dicarboxylate and Alkylsulfonic acid phenyl esters have been found to be suitable as medical compositions.

  The above conditions and results are summarized in Table 1. The numerical values of the materials in Table 1 indicate parts by weight.

(Examples 5 to 18, Comparative Example 8)
Based on the compounding prescription of Tables 2-3, the kind of silane compound in a hard compounding system, and the addition amount effect were investigated. Each component was weighed, all the components were hand-mixed together, and this blend was put into a two roll controlled at a surface temperature of 160 ° C. and kneaded for 5 minutes. The obtained roll sheet was cut into a predetermined size, and a sheet having a predetermined thickness was prepared with a press molding machine. The pressing conditions were 170 ° C preheating for 2 minutes, heating for 2 minutes, and then a cooling press for 5 minutes. The obtained sheet was subjected to various measurements such as radiation resistance.

  Comparative Example 8 is an example of a soft resin. Although it is a compounding system in which the amount of silane compound (3-methacryloxypropyltriethoxysilane) is greatly increased to 18 parts by weight, ΔYI becomes extremely small and radiation resistance is improved, but Rockwell hardness Is 35 ° or less and is not hard, and the elution is rejected, indicating that it cannot be used as a hard composition.

  From Examples 5 to 14 in which the addition amount of 3-methacryloxypropyltriethoxysilane was changed, the optimum addition range of the silane compound was 0.2 to 0.2 in consideration of the balance between Rockwell hardness, γ-ray resistance, and dissolution property. It turns out that it is 7 weight part.

  From the comparison of Examples 7, 10, and 12, the Rockwell hardness is within the acceptable range, and from the viewpoint of γ-ray resistance and elution, vinyltriethoxysilane and tetraethoxysilane are excellent, especially vinyltriethoxysilane. It can be seen that the performance balance is extremely excellent.

  In Examples 13 to 14, it was confirmed that the Rockwell hardness was within the acceptable range even when the blending of the plasticizer was reduced to 1% by weight, and the γ-ray resistance and the dissolution property were satisfied.

  Examples 15 to 16 were examined for blending of plasticizers, and Examples 17 to 18 were further examined for blending of silane compounds. All Rockwell hardnesses were within the acceptable range, γ-ray resistance and elution properties. We were able to confirm that

  The above conditions and results are summarized in Tables 2-3. The numerical value of the material in Tables 2-3 shows a weight part.

Claims (7)

A composition comprising 1 part by weight or more and 15 parts by weight or less of one or more plasticizers selected from cyclohexane dicarboxylate plasticizers and alkylsulfonic acid plasticizers with respect to 100 parts by weight of vinyl chloride resin. Because
A hard medical vinyl chloride resin composition characterized in that the Rockwell hardness defined by JIS K7202 is hard at 35 ° or more. The composition further contains 0.2 to 7 parts by weight of a silane compound, the plasticizer is a cyclohexanedicarboxylate plasticizer, and the silane compound is 3-methacryloxypropyltriethoxysilane and vinyltrimethylsilane. The hard medical vinyl chloride resin composition according to claim 1, which is at least one selected from ethoxysilane . 2. The rigid medical vinyl chloride resin composition according to claim 1, wherein the plasticizer is an alkylsulfonic acid plasticizer or both a cyclohexanedicarboxylate plasticizer and an alkylsulfonic acid plasticizer . The hard medical vinyl chloride resin composition according to claim 1 or 3 , wherein the composition further contains 0.2 to 7 parts by weight of a silane compound . The hard medical vinyl chloride resin composition according to claim 4 , wherein the silane compound is at least one selected from a monoalkoxysilane compound, a dialkoxysilane compound, a trialkoxysilane compound, and a tetraalkoxysilane compound . 6. The rigid medical vinyl chloride resin composition according to claim 1, wherein the resin composition has a ΔYI of 20 or less before and after γ-ray irradiation . A hard medical part formed by molding the hard medical vinyl chloride resin composition according to any one of claims 1 to 6 .