JPS5931340B2 - medical molded body - Google Patents

Description

[Detailed description of the invention] The present invention relates to a medical molded article.

More specifically, the present invention relates to a molded article made of a transparent and soft polyester elastomer having a specific composition and particularly suitable for medical use.

Medical polymer materials are used in disposable medical products, medical tools, testing supplies, artificial organs, etc., and play a major role in the development of clinical medicine. Rubber or plastic disposable medical supplies include syringes, needles, catheters, blood bags, IV infusion sets, blood transfusion sets,
They are widely used in medical care, from blood transfusion bags and gloves5 to clinical testing tools such as test tubes, beakers, and stopcocks. In particular, 10-plasticized polyvinyl chloride resin is most widely used in tubes and bags that require transparency and flexibility, such as blood transfusion sets, infusion sets, catheters, artificial heart-lung circuits, and blood storage bags. However, several problems have recently been raised regarding plasticized polyvinyl chloride resins. The first is the elution of plasticizer from the product.

The content of plasticizer 15 is generally very large, and many of the plasticizers useful as plasticizers for softening are concerned about their toxicity. The second problem is the elution of vinyl chloride monomer, and the third problem is the elution of metal ions such as lead, tin, cadmium, and barium used as heat stabilizers. In other words, plasticized soft vinyl chloride materials have been developed as disposable medical materials because they are transparent, flexible, and inexpensive; however, they pose safety problems due to the elution of plasticizers, monomers, stabilizers, etc. There is. 25 Silicone rubber, polyurethane, and the like are listed as medical polymer materials that should replace polyvinyl chloride resin.

However, although silicone rubber has no safety problems, it lacks transparency and has insufficient mechanical strength, which limits its use.

Although it is known that medical materials have recently been developed from polyurethane elastomers and polyester elastomers, polyurethane elastomers have problems with flexibility and coloring, and their strength or elasticity gradually decreases during use. It has a tendency to disappear and is also inferior in terms of biological reactivity.

Polyester elastomer is considered to be the best polymeric material for medical use from the standpoint of safety. There is a problem with poor properties, and when attempts are made to improve flexibility and transparency, the stickiness becomes significant, making it impossible to obtain a satisfactory molded product. On the other hand, if the crystallinity of the polyester elastomer itself is increased in order to improve adhesion, a molded product with satisfactory flexibility and transparency cannot be obtained.

Flexibility is required, for example, in order to stably send the liquid inside due to the bending phenomenon (kick) of the tube, and transparency is an essential condition for observing the position of the internal liquid and discovering foreign objects and bubbles. be. The present invention provides a new material that does not have the drawbacks of such conventional materials, is transparent, flexible, elastic, and has excellent safety.

That is, the present invention uses 100 to 60 moles of isophthalic acid. and 0 to 40 moles of terephthalic acid? as a dicarboxylic acid component, neopentyl glycol and a number average molecular weight of about 5.
00 to 3000 poly(alkylene oxide) glycol as a glycol component, and the poly(alkylene oxide) glycol unit is: 5 to 60% by weight based on the total copolymer. The present invention relates to a polyester elastomer medical molded article consisting essentially of a polyester copolymer.

The polyester elastomer used in the present invention essentially consists of a block polyether polyester copolymer (hereinafter simply referred to as block copolymer) composed of intramolecular linear polyether units and polyester units. In the block copolymer, the intramolecular linear polyether units form soft segments. Polyethylene terephthalate copolymers and polybutylene terephthalate copolymers, which have been previously studied as polyester hard segments, are crystalline polymers that cannot be heated, solvents,
It crystallizes and becomes cloudy when exposed to water. The polyester elastomer of the present invention is characterized in that essentially amorphous and rigid polyester is used as the hard segment. The polyester hard segment of the block copolymer of the present invention contains 100 to 60 mol% of isophthalic acid and 0 to 40 mol% of terephthalic acid. The dicarboxylic acid component is a mixture of the above, and the glycol component is substantially composed of neopentyl glycomonol.

In other words, is the polyester hard segment polyneopentylene isophthalate or 40 moles? This is a polyneopentylene isophthalate/terephthalate copolymer in which the polyneopentylene terephthalate components listed above are copolymerized. Polyneopentylene isophthalate is amorphous and maintains its transparency without becoming devitrified during high-temperature steam sterilization or ethylene oxide sterilization of molded products. Furthermore, since it has a rigid aromatic skeleton even though it is amorphous, it has a relatively high glass transition temperature and low tackiness during molding. Polyneopentylene isophthalate contains up to 40 mol%, preferably 30 mol%? Up to 40 to 65 moles of terephcrate components may be copolymerized. In the terephthalic acid copolymerization, the molded product becomes sticky after melt molding, which is undesirable, and the molar ratio of polyneopentylene isophthalate/terephthalate copolymer is
/(65-100), when polyneopentylene terephthalate is the main component, crystallinity develops and transparency is lost during steps such as heat treatment and sterilization. The use of neopentyl glycol as the substantial main component of the glycol component is essential in the present invention, and other glycols have advantages such as flexibility, transparency, good moldability, and prevention of deterioration during the sterilization process of molded products. cannot be achieved. In the block copolymer of the present invention, the hard segment is essentially a copolymer of polyneopentylene isophthalate or polyneopentylene isophthalate/terephthalate (100-60/0-40), but a small amount of copolymerization component It is also possible to add other dicarboxylic acids, diols, and trifunctional or higher functional polycarboxylic acids, polyols, and polyoxycarboxylic acids to form a polymer suitable for the intended use. In particular, polyfunctional components can increase melt viscosity and polymerization rate, such as trimellitic acid, trimesic acid, pyromellitic acid, 3,y,4,4'-benzophenonetetracarboxylic acid, , 2,3,4-butanetetracarboxylic acid and derivatives thereof such as acid esters and acid anhydrides, glycerin, pentaerythritol, and the like. The amount that these can be copolymerized is 20 moles of diol component and dicarboxylic acid component? Below, preferably 10 moles? Below, is the polyfunctional component 5 moles? The content is preferably 3 mol% or less. The component forming the soft segment of the block copolymer used in the present invention has a molecular weight of 500 to 3000.
of poly(alkylene oxide) glycol, and its amount is 5 to 65% by weight of the total polymer. , especially 10-50 weight 7
Preferably, it is 0.

When the amount of poly(alkylene oxide) glycol is less than 5% by weight, the flexibility requirement is not satisfied. 65 again
If the amount is more than % by weight, the heat distortion temperature will be low and it will not be able to withstand high temperature sterilization, and tackiness will develop during molding, making it difficult to form a molded product in the desired shape. The poly(alkylene oxide) glycols include polyethylene glycol, poly(1,2- and 1,3-
- propylene oxide) glycol, poly(tetramethylene oxide) glycol, poly(hexamethylene oxide) glycol and copolymers thereof, etc.
They may be used alone or in combination of two or more.

The number average molecular weight of poly(alkylene oxide) glycol is 500 to 3000, more preferably 800 to 2000.
If poly(alkylene oxide) glycol with a molecular weight smaller than 500 is copolymerized, the heat resistance and water resistance of the polymer will decrease, and if the molecular weight is too large, depending on the type, poly(alkylene oxide) glycol It itself becomes crystalline, and the compatibility with the hard segment deteriorates, resulting in a decrease in transparency. Particularly preferred soft segment units have a number average molecular weight of about 800 to
1500 poly(tetramethylene oxide) glycol. That is, the block copolymer used in the present invention comprises (4) isophthalic acid and/or its ester-forming derivative, 8-terephthalic acid and/or its ester-forming derivative, and (C) neopentyl glycol and/or its ester. Formation derivative, poly(alkylene oxide) with a number average molecular weight of 500 to 3000
The four components of glycol and/or its ester-forming derivative (A), (0, 9 or ClV), (B), ri), and [F]) are added to the resulting polymer (
A titanate complex such as MgCHTl(0R)6, which is derived from a metal alkoxide and a titanate ester, in which the components 5 to 5) is also one of the preferred catalysts.

By using such a catalyst system, it is possible to obtain a polymer having a high degree of polymerization suitable for providing a polyester elastomer molded article that meets the purpose of the present invention. In the polyester elastomer of the present invention, antioxidants, light-resistant agents, fillers, brighteners, colorants, reinforcing agents, etc. can be added to the block copolymer within a range that does not impair the purpose of the polyester elastomer.

The medical molded article of the present invention does not contain any plasticizer for softening, such as plasticized polyvinyl chloride, and has sufficient flexibility, so there is no concern about toxicity to the human body.

In addition, the block copolymer used in the present invention satisfies flexibility and transparency, has low stickiness, and is easy to mold, so it can be molded as it is and used as a medical molded article. It can also be used for molding as a polyester elastomer blended with various thermoplastic resins for the purpose of improving slipperiness or increasing curing speed.

Examples of such thermoplastic resins include polyesters such as polybutylene terephthalate, polyethylene terephthalate, polyhexamethylene terephthalate, and polyethylene sebacate, and random copolymer polyesters such as polybutylene terephthalate/isophthalate, polybutylene terephthalate/phthalate, and polyethylene terephthalate/isophthalate. , polybutylene terephthalate/poly(tetramethylene oxide) glycol, polyether polyester copolymers such as polybutylene terephthalate/isophthalate/poly(tetramethylene oxide) glycol, polyether type urethane, polyester type urethane, polycarbonate Various thermoplastic polyurethanes such as molded urethanes, various polyamides and their copolymers such as polycaproamide and polylaurylamide, polystyrene, polypropylene, polyethylene, polycarbonate, sunalene-butadiene block copolymers, and metal ion-containing ethylene-methacrylic acid. A wide range of products can be mentioned, such as copolymers, and the amount that can be blended into the block copolymer of the present invention depends on the purpose and use, but generally 3.
Up to 0% by weight. Thermoplastic resins that are particularly compatible, flexible without loss of transparency, and particularly useful for achieving the above-mentioned modification purpose are random and block copolymer polyesters or polyether esters. The medical molded article of the present invention is a tubular body, hollow body, film/sheet-like article, or other product obtained by molding the above-mentioned polyester elastomer by a conventional method such as extrusion molding, blow molding, or injection molding. It is a shape, and may be subjected to treatments such as stretching, cooling, and heat treatment as necessary.

The polyester elastomer molded article of the present invention can be used as medical materials such as various medical tubes, catheters, etc. such as infusion sets, blood transfusion sets, blood bags, infusion bags, artificial dialysis circuits, venous catheters, sheet-type oxygenators, artificial heart-lung circuits, etc.
In addition to bags, etc., we also use transparency, flexibility, safety, chemical resistance, resistance to water decomposition, etc. to produce tubes for eating and drinking, bags, films, chemical liquid transfer tubes, single-person chemical liquid storage bags, etc. Can also be used as tubes, bottles, and bags.

Specific examples of the present invention will be explained in detail below.

The melting points in the examples of the present invention were measured using a thermomechanical analyzer (TMA: Thermo-Mechanical Analyzer manufactured by Rigaku Corporation).
lysis), pin size 0.5 φ, load 5
9. Measurement was carried out at a temperature at which the needle penetrated 250 μm into the sample under measurement conditions of 4 temperature increases and a rate of 10° C./min.

Further, the relative viscosity was measured in orthochlorophenol at 25° C. and a concentration of 0.5%.

Transparency is expressed by total transmittance and haze, both of which were measured from a sheet sample cut into a sheet or tube using an HTR meter SHP-H model (integrating sphere type) manufactured by Nippon Seimitsu Kogaku.

Example 1 175 parts of dimethyl isophthalate, 19.4 parts of dimethyl terephthalate, 1.9 parts of trimellitic anhydride, poly(tetramethylene oxide) with a number average molecular weight of about 1000
49.1 parts of glycol and 1 part of neopentyl glycol
56 parts of the titanium tetrabutoxide catalyst was charged into a reaction vessel equipped with a helical phone stirring blade, and 21 parts of the titanium tetrabutoxide catalyst was charged.
The mixture was heated to 0° C. for 2 hours, and theoretical methanol was distilled out of the system.

The temperature of the reaction mixture was then raised to 240'C, and the pressure inside the system was then reduced to 0.2mlH9 over 30 minutes, and polymerization was carried out under these conditions for 3 hours. The resulting polyether polyester copolymer had a melting point of 122° C1 and a relative viscosity of 1.95. The soft segment unit of polytetramethylene) oxide dalicol in the polymer was 20%. The obtained polymer was dried in a hot air dryer at 80°C for 3 hours, then introduced into an extruder heated to 180°C, and extruded into ice-cooled water at 3°C in a cylindrical shape through a die to give an outer diameter of 10 mm. The tube had an inner diameter of 8 mm and a thickness of 1 inch. At this time, there was little stickiness and the molding was smooth. This tube has a total transmittance of 86? It was excellent in transparency, had a flexural modulus of 200 kg/d, was highly flexible, and was in a state where kicks (bending of the tube) were unlikely to occur. Furthermore, changes in transparency of the obtained tubes under various sterilization conditions were investigated by the following method.
The results are shown in Table 1, and it can be seen that high transparency is maintained. (1) Boiling in boiling sterilized water for 3 hours (2) Ethylene oxide gas sterilization Ethylene oxide/carbon dioxide gas (10V01%/90V
01% Example 2 194 parts of dimethyl isophthalate, number average molecular weight approximately 80
0 poly(tetramenalene oxide) glycol 81,
4 parts and 208 parts of neopentyl glycol under the same conditions as in Example 1, using polyneopentylene isophthalate as a hard segment and poly(tetramethylene oxide) glycol as a soft segment, using 30 parts by weight? It was made into a block polyether polyester copolymer containing the same.

The melting point of the obtained polymer was 125°C, and the relative viscosity was 2.1.
It was 0. This polymer was formed into a 1 mm thick sheet by hot pressing at 200'C, cooled in a water-cooled mold, and then taken out. Basic performance evaluation as a medical material was carried out by the following method, and the results are shown in Table 2.

Adhesiveness: Judging by pressing the sheets together Flexibility: Measurement of tensile modulus Transparency: Treatment in water at 80°C for 3 hours, measuring transmittance and haze before and after treatment Table 2 also shows the results of similar tests conducted on polyether ester and vinyl chloride.

Claims (1)

[Claims] 1 100-60 mol% isophthalic acid and 0 terephthalic acid
~40 mol% of the mixture is a dicarboxylic acid component, neopentyl glycol and a number average molecular weight of approximately 500 to 300.
It is a copolymer containing 0 poly(alkylene oxide) glycol as a glycol component, and the poly(alkylene oxide) glycol units are 5 to 5 to
A polyester elastomer medical molded article consisting essentially of 65% by weight of a block polyether polyester copolymer.