Molding material, molded article, and catheter

Abstract

The purpose of the present invention is: to provide a molding material comprising a thermoplastic polyurethane that enables the formation of a molded article having flexibility, and such molded article; and to provide an indwelling catheter using this molding material, the catheter being resistant to kinking even if the diameter is small. The catheter comprises a molding material containing a thermoplastic polyurethane having a hard segment including a structural unit derived from an aromatic isocyanate compound and a soft segment including a structural segment derived from a carbonate-based polyol, and having a hardness of A65 or less. Also, the molding material comprises a thermoplastic polyurethane having a hard segment containing a structural unit derived from an aromatic isocyanate compound and a soft segment containing a structural unit derived from a carbonate-based polyol. The carbonate-based polyol includes, as a polyol component, a structural unit derived from 1,10-decanediol.

Description

Molding material, molded body, and catheter

[0001] The present invention relates to a molding material and a molded article containing the same. The present invention also relates to a catheter.

[0002] Medical tubes, particularly indwelling catheters, are inserted into blood vessels and used for the infusion of fluids and medicinal solutions. Indwelling catheters include cardiovascular catheters, including central venous catheters, peripheral venous catheters, coronary artery catheters, and CV port catheters, as well as blood collection kits and medication tubes. Depending on the application, indwelling catheters are often left in place for several days to several months, requiring high durability and chemical resistance. Therefore, carbonate-based thermoplastic polyurethanes are often used. Meanwhile, the narrow veins of pediatric patients often make existing indwelling catheters too small for these needs, creating a demand for small-diameter catheters that are less prone to kinking. Kinking refers to a condition in which a catheter is bent, twisted, or twisted, causing a narrowing within the catheter and preventing the passage of gases or liquids.

[0003] The use of a specific carbonate-based thermoplastic polyurethane in medical tubing related to this indwelling catheter has been disclosed (Patent Document 1).On the other hand, as a carbonate-based thermoplastic polyurethane, one containing an aliphatic isocyanate in the hard segment and a polycarbonate diol using 1,10-decanediol and 1,4-butanediol in the soft segment has been disclosed (Patent Document 2).

[0004] Japanese Patent Publication No. 2001-46492 Japanese Patent Publication No. 2023-123870

[0005] The thermoplastic polyurethane tube described in Patent Document 1 is too rigid for use in small-diameter tubes and leaves room for improvement. Furthermore, the thermoplastic polyurethane described in Patent Document 2 is not intended for use in catheters, but the inventors' investigations have revealed that when this was applied to catheters, it had insufficient flexibility and insufficient kink resistance.

[0006] Therefore, an object of the present invention is to provide a molding material containing thermoplastic polyurethane that can give a molded article having excellent flexibility and that is resistant to kinking when molded into a tubular shape (excellent kink resistance). Another object of the present invention is to provide a catheter, particularly an indwelling catheter, that is resistant to kinking even when it has a small diameter.

[0007] As a result of intensive research into solving the above problems, the present inventors have found that the above problems can be solved by using a molding material containing a thermoplastic polyurethane having a specific structure.The present inventors have also found that the above problems can be solved by a catheter containing a thermoplastic polyurethane having a specific structure and physical properties as a molding material.The present invention is summarized as follows.

[0008] [1] A catheter comprising a molding material containing a thermoplastic polyurethane having a hard segment containing a structural unit derived from an aromatic isocyanate compound and a soft segment containing a structural unit derived from a carbonate-based polyol, and having a hardness of A65 or less. [2] A molding material containing a thermoplastic polyurethane having a hard segment containing a structural unit derived from an aromatic isocyanate compound and a soft segment containing a structural unit derived from a carbonate-based polyol, and containing a structural unit derived from 1,10-decanediol as a polyol constituent that constitutes the carbonate-based polyol.

[0009] According to the present invention, a molded article having excellent flexibility can be obtained, and a molding material containing thermoplastic polyurethane having excellent kink resistance when molded into a tubular shape can be provided. Furthermore, according to the present invention, a catheter, particularly an indwelling catheter, that is resistant to kinking even when small in diameter can be obtained.

[0010] Hereinafter, embodiments of the present invention will be described. The following embodiments are merely examples for explaining the present invention, and are not intended to limit the present invention to these embodiments. The present invention can be implemented in various ways without departing from the spirit of the present invention.

[0011] In this specification, when "X to Y" (X and Y are any numbers) is expressed, unless otherwise specified, it means "X or more and Y or less," as well as "preferably more than X" or "preferably less than Y." Furthermore, when "X or more" (X is any number) or "Y or less" (Y is any number) is expressed, it also means "preferably more than X" or "preferably less than Y." With regard to the numerical ranges described in stages in this specification, the upper limit or lower limit of a certain numerical range can be arbitrarily combined with the upper limit or lower limit of a numerical range in another stage. Furthermore, in the numerical ranges described in this specification, the upper limit or lower limit of the numerical range can also be replaced with the values ​​shown in the examples.

[0012] The catheter of the present invention includes a molding material containing a thermoplastic polyurethane as described below. The molding material of the present invention also includes a thermoplastic polyurethane as described below.

[0013] <Thermoplastic polyurethane> The thermoplastic polyurethane used in the present invention has a hard segment containing a structural unit derived from an aromatic isocyanate compound and a soft segment containing a structural unit derived from a carbonate-based polyol. The hard segment may contain, in addition to the structural unit derived from the aromatic isocyanate compound, a structural unit derived from another isocyanate compound or a structural unit derived from a chain extender. Furthermore, the soft segment may contain, in addition to the structural unit derived from the carbonate-based polyol, a structural unit derived from an ether-based polyol, an ester-based polyol, or the like.

[0014] [Hard Segment] The hard segment is a general term for structural units derived from the isocyanate compound and optionally used chain extender among the components constituting the thermoplastic polyurethane. The content of the hard segment can be expressed as the total amount of the hard segment and soft segment, i.e., the content (% by mass) of structural units derived from the isocyanate compound and chain extender relative to the entire thermoplastic polyurethane. From the viewpoint of mechanical strength, the content of the hard segment in the thermoplastic polyurethane is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 12% by mass or more, particularly preferably 14% by mass or more, particularly preferably 15% by mass or more, and most preferably 16% by mass or more. Furthermore, from the viewpoint of hardness (flexibility), the content of the hard segment in the thermoplastic polyurethane is preferably 23% by mass or less, more preferably 22% by mass or less, and even more preferably 21% by mass or less.

[0015] The hard segment contains a structural unit derived from an aromatic isocyanate compound. Examples of the aromatic isocyanate compound include xylylene diisocyanate, 4,4'-diphenyl diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate), o-phenylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, and m-tetramethylxylylene diisocyanate. These compounds may be used alone or in combination of two or more. MDI is preferred in terms of polymerization stability and mechanical strength.

[0016] The hard segment may contain a structural unit derived from an isocyanate compound other than an aromatic isocyanate compound. Examples of the isocyanate compound other than an aromatic isocyanate compound include aliphatic diisocyanates such as tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and dimer diisocyanate in which the carboxyl group of a dimer acid is converted into an isocyanate group. Isocyanate compounds: alicyclic diisocyanate compounds such as 1,4-cyclohexane diisocyanate, isophorone diisocyanate (IPDI), 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,3-bis(isocyanatomethyl)cyclohexane, and 1,4-bis(isocyanatomethyl)cyclohexane.

[0017] The chain extender is a low molecular weight compound having two or more active hydrogen groups at the terminals that react with isocyanate groups, and examples thereof include short-chain polyols and polyamines. Examples of the short-chain polyols include linear diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol; propylene glycol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-heptanediol, 1,4-dimethylolhexane, 2-ethyl-1,3-hexanediol, and 2,2,4-trimethyl-1,3-pentanediol. Examples of suitable diols include branched diols such as hexanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, and dimer diol; diols having an ether group such as diethylene glycol, dipropylene glycol, and triethylene glycol; diols having an alicyclic structure such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and 1,4-dihydroxyethylcyclohexane; diols having an aromatic group such as xylylene glycol, 1,4-dihydroxyethylbenzene, and 4,4'-methylenebis(hydroxyethylbenzene); and polyols such as glycerin, trimethylolpropane, and pentaerythritol. Ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol are particularly preferred.

[0018] Examples of the polyamine include ethylenediamine, hexamethylenediamine, and isophoronediamine, with ethylenediamine being particularly preferred.

[0019] The thermoplastic polyurethane used in the present invention preferably has a ratio (NCO Index) of the total number of moles of isocyanate groups in the isocyanate compound to the total number of moles of active hydrogen groups in the chain extender and polyol adjusted to 0.8 to 1.2, more preferably 0.9 to 1.1. By adjusting this ratio to 0.8 or more, sufficient mechanical strength can be obtained. Furthermore, by adjusting this ratio to 1.2 or less, it is possible to almost completely eliminate unreacted isocyanate functional groups.

[0020] <Soft Segment> The soft segment is a general term for a structural unit composed of a polyol that constitutes a thermoplastic polyurethane, and the soft segment amount can be expressed as the total amount of the hard segment and the soft segment, i.e., the content (% by mass) of the structural unit derived from the polyol relative to the entire thermoplastic polyurethane. The soft segment content of the thermoplastic polyurethane is the remainder (% by mass) of the hard segment content described above.

[0021] Since the polyol undergoes rearrangement crystallization depending on its chemical structure and number-average molecular weight, it is preferable to adjust the soft segment content depending on the number-average molecular weight. When the number-average molecular weight of the polyol is 2,500 or more and 4,000 or less, the soft segment content is preferably 95% by mass or less, and from the viewpoint of mechanical strength, it is more preferably 90% by mass or less, and even more preferably 88% by mass or less. On the other hand, from the viewpoint of hardness, it is more preferably 80% by mass or more, even more preferably 82% by mass or more, and particularly preferably 86% by mass or more. When the number-average molecular weight of the polyol is 500 or more and 2,400 or less, from the viewpoint of surface tackiness, it is more preferably 86% by mass or less, even more preferably 83% by mass or less, and particularly preferably 80% by mass or less. On the other hand, from the viewpoint of hardness, it is preferably 79% by mass or more.

[0022] The carbonate-based polyol is included as a polyol constituent component constituting the carbonate polyol, i.e., as a constituent component derived from the polyol constituent component constituting the carbonate component of the carbonate-based polyol. Examples of this polyol include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,10-decanediol. Among these, it is preferable to include 1,10-decanediol as a constituent component, and it is particularly preferable to include 1,4-butanediol as a constituent component in addition to 1,10-decanediol.

[0023] When the polyol component constituting the carbonate polyol is a carbonate polyol using the aforementioned 1,10-decanediol and 1,4-butanediol, the content ratio of the component derived from 1,10-decanediol to the component derived from 1,4-butanediol, (component derived from 1,10-decanediol) / (component derived from 1,4-butanediol), is preferably 5 / 95 to 95 / 5, and more preferably 10 / 90 to 90 / 10. By setting the ratio at 5 / 95 or more, the proportion of carbonate bonds in the carbonate polyol is not too high, and when the thermoplastic urethane according to the present invention is formed, the viscosity is not too high, and good handleability is easily maintained. From the viewpoint of the viscosity of the carbonate polyol, the upper limit is more preferably 50 / 50 or less, and even more preferably 30 / 70 or less. On the other hand, by making the ratio 95 / 5 or less, the crystallinity of the carbonate polyol does not become too high, and when it is made into the thermoplastic urethane of the present invention, the hardness can be prevented from becoming too high.

[0024] The carbonate polyol can be produced by reacting a polyol to be used with a carbonic acid diester (ester exchange reaction) to obtain a carbonic acid ester, and then subjecting the resulting ester to a condensation reaction with a polyol.

[0025] The number average molecular weight of the carbonate polyol is preferably from 500 to 4000, more preferably from 500 to 3500 from the viewpoint of the urethane reaction, and more preferably from 500 to 2400 from the viewpoint of the change in hardness of the thermoplastic polyurethane over time. These polyols may be used alone or in combination of two or more.

[0026] The content of the hard segments in the thermoplastic polyurethane is as described above, but is preferably within the following ranges depending on the number-average molecular weight of the carbonate-based polyol. When the number-average molecular weight of the carbonate-based polyol contained in the soft segment is 2,500 to 4,000, the content of the hard segments is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 12% by mass or more, and particularly preferably 14% by mass or more, from the viewpoint of hardness. On the other hand, it is more preferably 16% by mass or less, even more preferably 15% by mass or less, and particularly preferably 14% by mass or less. When the number-average molecular weight of the carbonate-based polyol contained in the soft segment is 500 to 2,400, the content of the hard segments is preferably 10% by mass or more, more preferably 12% by mass or more, even more preferably 14% by mass or more, and particularly preferably 16% by mass or less, from the viewpoint of surface tackiness. On the other hand, it is preferably 23% by mass or less, more preferably 22% by mass or less, and even more preferably 21% by mass or less, from the viewpoint of hardness.

[0027] <Analysis of the chemical structure of thermoplastic polyurethane> The chemical structure of thermoplastic polyurethane is １３ It can be analyzed by C-NMR. １３ When it is difficult to distinguish the unit structure by C-NMR analysis alone, a model thermoplastic polyurethane is synthesized and １３ The results of C-NMR measurement and the thermoplastic polyurethane to be analyzed １３ Structural analysis can also be performed by comparing the results of C-NMR measurements with those of C-NMR. In addition, the thermoplastic polyurethane to be analyzed is subjected to alkaline decomposition under conditions that decompose the carbonate bond but not the urethane bond, and then analyzed by gas chromatography. １３The determination may be made by combining C-NMR.

[0028] <Method for producing thermoplastic polyurethane> Known production methods can be applied to the thermoplastic polyurethane used in the present invention. Specific examples include a one-shot method (solution polymerization method) in which the isocyanate compound, chain extender, and carbonate polyol are mixed together and reacted, and a prepolymer method in which the isocyanate compound and carbonate polyol are reacted to prepare a prepolymer having isocyanate groups at both ends, and then the prepolymer is reacted with a chain extender. Other methods include a solvent polymerization method in which the reaction is carried out in a solution, and a bulk polymerization method in which the reaction is carried out under solvent-free conditions.

[0029] When the thermoplastic polyurethane used in the present invention is produced by solution polymerization, a solvent may be used. This solvent is typically an organic solvent, and there are no particular limitations on the organic solvent as long as it can dissolve the thermoplastic polyurethane. However, organic solvents that are liquid at 1 atmosphere are preferred. Examples of organic solvents that can be used include N,N-dimethylformamide, N,N-dimethylacetamide, MEK (methyl ethyl ketone), cyclohexanone, ethyl acetate, and butyl acetate. N,N-dimethylacetamide is particularly preferred.

[0030] The catalyst used in the method for producing thermoplastic polyurethane is intended to promote the reaction between the isocyanate group of the isocyanate compound and the active hydrogen groups possessed by the chain extender and the polyol, and known urethane polymerization catalysts such as amine-based catalysts such as triethylamine, N-ethylmorpholine, triethylenediamine, etc., or tin-based compounds such as trimethyltin laurate, dibutyltin dilaurate, dioctyltin dilaurate, dioctyltin dineodecanoate, and organometallic salts of titanium-based compounds can be used.

[0031] <Molding Material> The molding material of the present invention contains the thermoplastic polyurethane described above. This molding material is typically a composition containing the thermoplastic polyurethane, which is used as a material for melt molding. Additives and the like can be added or mixed to the molding material as long as they do not impair the properties of the thermoplastic polyurethane used in the present invention. Examples of such additives include antiblocking agents, light stabilizers, heat stabilizers, antioxidants, lubricants, UV absorbers, and contrast agents. Examples of the contrast agent include barium sulfate, tungsten, and bismuth.

[0032] The thermoplastic polyurethane used in the present invention has high polarity and tends to easily absorb water under storage conditions. When producing a molded article, it is preferable to pre-dry the thermoplastic polyurethane at an appropriate temperature and time to adjust the moisture content of the molding material to an appropriate range, and then use the molding material for molding. By using an appropriate pre-drying temperature and time, melting of the molding material containing volatile components can be prevented, thereby suppressing defects such as foaming and poor appearance. Furthermore, thermal degradation of the molding material can be prevented, and deterioration of the physical properties and discoloration of the molded article can be suppressed. The water content and organic solvent content in the molding material reduced by this operation are described below. Note that the method for reducing the water and organic solvent content is not limited to the above-mentioned operation. For example, the organic solvent may be reduced by recrystallizing the thermoplastic polyurethane used in the present invention. Furthermore, drying is not limited to pre-drying, and may be performed after mixing additives, etc., with the thermoplastic polyurethane.

[0033] <Molded Article> The molding material of the present invention can be molded to obtain a molded article (article). Examples of the shape of the obtained molded article (article) include a tube, a packing sheet, a sealing material, a film, and a three-dimensional shape.

[0034] The method for producing a molded body (article) by molding the molding material of the present invention is preferably a melt molding method, such as extrusion molding, injection molding, compression molding, blow molding, rotational molding, casting, and melt spin molding. Of these, extrusion molding and injection molding are preferred in terms of productivity. The mold, resin temperature, molding conditions, etc. used when molding using a molding machine are not particularly limited. In addition to melt molding, methods for producing a molded body (article) by molding the molding material of the present invention may also be used, such as solvent casting, dip molding, and electrospinning.

[0035] The content of thermoplastic polyurethane in the molding material of the present invention is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more. It is also preferably 100% by mass or less, more preferably 98% by mass or less, and more preferably 95% by mass or less. By keeping it within this range, the molding material and the molded article can fully exhibit the flexibility and kink resistance due to the properties of the thermoplastic polyurethane.

[0036] <Physical Properties of Molding Material and Molded Article> The molding material of the present invention is required to have the property of being less likely to kink when molded into a tubular shape such as an indwelling catheter. As physical properties that exhibit this property, it is preferable that hardness, modulus, tensile strength, and elongation satisfy the following requirements.

[0037] [Hardness] The molding material of the present invention is molded into a sheet to obtain a test specimen, and the Shore hardness is measured using a rubber hardness tester with reference to ISO 7619-1. When three 3 cm square, 2 mm thick sheets are used as the test specimen, the Shore hardness is preferably A50 or higher, more preferably A59 or higher. Setting the hardness above the lower limit ensures sufficient mechanical strength. On the other hand, A74 or lower is preferable, A70 or lower is more preferable, and A65 or lower is even more preferable. Setting the hardness below the upper limit makes it possible to suppress the occurrence of kinking. Furthermore, as shown in the experimental examples below, small change in hardness is preferable. Here, "hardness change" means small change in hardness between immediately after molding and after some time has passed since molding. Depending on the molding material, hardness may change over time after molding, but in the present invention, it is preferable that the hardness be maintained within the above range even over time.

[0038] In the hardness notation, "A" indicates that a specific indenter (a cone with a 35° angle) was used and a load of 1 kg was used to measure the hardness. A similar notation for hardness is "D," which indicates that a specific indenter (a cone with a 30° angle) was used and a load of 5 kg was assumed. "A" is mainly used to measure soft materials such as soft rubber, elastomers, and natural rubber, while "D" is mainly used to measure hard materials such as hard elastomers, plastics, and hard thermoplastics. The numbers before and after "A" and "D" indicate the depth of indentation when a specific indenter is used.

[0039] [Tensile Break Strength and Tensile Break Elongation] A tensile test is performed with reference to ISO 037-02 under conditions of a gauge length of 20 mm and a tensile speed of 200 mm / min, and the median stress at break is defined as the tensile break strength, and the elongation at break is defined as the tensile break elongation. This tensile break strength is preferably 10 MPa or more, and more preferably 25 MPa or more. By ensuring that it is equal to or greater than the above lower limit, burst fracture can be suppressed when used as a tube. From the standpoint of safety, the higher the tensile break strength, the better, but a strength of 80 MPa or less is sufficient.

[0040] The tensile elongation at break is preferably 300% or more, more preferably 450% or more. If it is equal to or greater than the lower limit, sufficient conformability can be obtained in the case of a two-color molded part. If it is equal to or less than the upper limit, excessive deformation does not occur, and clogging is less likely to occur when the tube is formed.

[0041] [tan δ] Tan δ is the ratio of storage modulus (E') to loss modulus (E'') (tan δ = (E'' / E')), and is used in the present invention as an index of kink resistance. The larger this value, the better the kink resistance is evaluated to be, and it is preferably 1.20 or more, more preferably 1.30 or more, even more preferably 1.40 or more, and particularly preferably 1.50 or more. There is no particular upper limit for tan δ, but it is usually 2.00 or less.

[0042] [Water Content] The molding material of the present invention preferably has a low water content from the viewpoint of moldability, particularly melt moldability. Specifically, the molding material of the present invention preferably has a water content of 2% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1% by mass or less.

[0043] [Content of organic solvent] The molding material of the present invention preferably has a low content of organic solvent from the viewpoint of moldability, particularly melt moldability. Specifically, the molding material of the present invention preferably has a content of organic solvent of 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less. The content of organic solvent can be measured by gas chromatography.

[0044] <Uses of Molding Material and Molded Article> As shown in the examples below, the molding material of the present invention and molded articles containing the same have excellent flexibility and mechanical properties. Therefore, they are suitable for medical tubing, particularly indwelling catheters, which require excellent kink resistance and high flexibility. In particular, the catheter portion of a CV (Central Venous) port, a type of central venous catheter, is inserted into a central vein, and the connected port member is implanted subcutaneously for use. Therefore, a low-hardness material is required to prevent damage to the blood vessel. Furthermore, since the outer diameter of the tube is extremely small, around 2 mm, there is a risk of kinking. However, the molding material of the present invention has excellent flexibility and is therefore less likely to kink.

[0045] The molding material of the present invention and molded articles containing the same can be bonded or welded to other parts or to tubes, sheets, or films to produce various products. Methods for welding molded articles using the resin composition of the present invention, i.e., the molding material of the present invention, include ultrasonic welding, vibration welding, high-frequency welding, hot plate welding, laser welding, and spin welding. As a method for bonding the molded articles, various adhesives can be appropriately selected and used, such as urethane-based, epoxy resin-based, vinyl acetate-based, acrylic resin-based, phenolic resin-based, chloroprene rubber-based, nitrile rubber-based, silicone rubber-based, styrene-butadiene rubber-based, and cyanoacrylate-based adhesives. Solvent bonding can also be used. Tape bonding, such as double-sided tape, can also be used.

[0046] When bonding dissimilar materials, multiple bonding methods can be combined depending on the materials to be bonded. For example, this method is suitable for medical device components such as catheters, guide wires, endoscopes, syringes, intravenous lines, cannulas, gauze, stents, shunt tubes, and other tubes, drains, coating materials, sealing materials, and packing. Furthermore, coating materials can also be used in fields other than medical device components.

[0047] The molded article is made of thermoplastic polyurethane made from a polycarbonate-based polyol, and therefore has excellent durability and high flexibility, making it suitable for use as a cushioning material for artificial knee joints, medical tubing, in particular the catheter portion of a CV port catheter, which is a type of central venous catheter and has a port site and a catheter, the catheter portion of a central venous catheter, a shunt, the housing portion of an endoscope, and scaffolding for regenerative medicine.

[0048] In the present invention, medical catheters correspond to the above-mentioned CV ports and central venous catheters, and thermoplastic polyurethanes are also used in urethral catheters, catheters for guide wires, etc. The molded article has excellent flexibility and is resistant to kinking, making it suitable for indwelling catheters among medical catheters.

[0049] In the present invention, an indwelling catheter refers to a catheter that is left in the body for more than a predetermined period of time, and examples thereof include CV ports and central venous catheters. An indwelling catheter using the molding material of the present invention has a port site and a catheter, and the catheter includes a catheter containing the molding material of the present invention. The CV port described above is composed of a port site including a part called a septum containing polyacetal, silicone, an alloy, or the like, and a catheter made of thermoplastic polyurethane. Catheters made of thermoplastic polyurethane are inserted and left in a blood vessel, and the molded article is suitable for an indwelling catheter because it has excellent flexibility and is less likely to kink.

[0050] The present invention will be described in more detail below with reference to examples and comparative examples. The present invention is not limited to these examples as long as it does not depart from the gist of the invention. Various evaluation methods in the experimental examples are as follows.

[0051] [Method of evaluating molding materials containing thermoplastic polyurethane] The molding materials containing thermoplastic polyurethane produced in the examples and comparative examples were evaluated according to the following methods.

[0052] <Hardness Evaluation> A molded sheet made of a molding material containing thermoplastic polyurethane and having a thickness of 2 mm was cut into a 3 cm square, and three of the sheets were stacked together to form a test piece. The test piece was used within one week after molding. Using an Asker Rubber Hardness Tester ISO-A Type (manufactured by Kobunshi Keiki Co., Ltd.), the hardness after 3 seconds of contact was determined with reference to ISO 7619-1.

[0053] <Evaluation of Hardness Change> Using molded articles that had been in contact for 60 days or more since molding, the hardness after 3 seconds of contact was measured using an Asker Rubber Hardness Tester ISO-A Type (manufactured by Kobunshi Keiki Co., Ltd.) with reference to ISO 7619-1. A smaller hardness value indicates superior flexibility. Furthermore, a smaller change in hardness indicates superior flexibility.

[0054] <Tensile Breaking Strength and Tensile Breaking Elongation> A molded sheet made of a molding material containing thermoplastic polyurethane and having a thickness of 2 mm was punched into a No. 3 dumbbell shape using a punching machine. A tensile test was performed using a tensile testing machine (AGS-10kNX, manufactured by Shimadzu Corporation) and an extensometer (DSES-1000, manufactured by Shimadzu Corporation) with reference to ISO 037-02, under conditions of a gauge length of 20 mm and a pulling speed of 200 mm / min. The median stress at break was taken as the tensile breaking strength, and the elongation at that time was taken as the tensile breaking elongation.

[0055] <Kink Resistance (tan δ)> A molded sheet made of a molding material containing thermoplastic polyurethane and having a thickness of 1 mm was cut into a length of 25 mm or more and a width of 4 mm to prepare a measurement piece. Measurement was carried out using a dynamic viscoelasticity measuring device (DVA-200, manufactured by IT Measurement Control Co., Ltd.) under the following measurement conditions. Measurement conditions: tensile temperature dependent mode, gauge length 25 mm, test temperature -100 to 250°C, frequency 10 Hz, heating rate 3°C / min, strain 0.03 to 0.1%. The larger the tan δ value, the better the kink resistance was evaluated.

[0056] <Moisture Measurement> A molded sheet of 1 mm thick made of a molding material containing thermoplastic polyurethane was cut into a test piece weighing approximately 0.3 to 0.5 g. Measurements were performed using a Karl Fischer trace moisture analyzer (CA-200 / VA-200, manufactured by Mitsubishi Chemical Analytech Co., Ltd. (now Nitto Seiko Analytech Co., Ltd.)). The test temperature was 190°C.

[0057] [Raw materials] (1) Hard segment ○ Isocyanate compounds ・MDI...4,4'-diphenylmethane diisocyanate, manufactured by Tosoh Corporation: Millionate MT ・H12MDI...4,4'-dicyclohexylmethane diisocyanate, manufactured by TCI ○ Chain extender ・1,4-BG...1,4-butanediol, manufactured by Mitsubishi Chemical Corporation

[0058] (2) Soft segment ○ Carbonate polyol PCD-1... Copolymer PCD of 1,10-decanediol / 1,4-butanediol = 10 / 90 (mol% ratio), number average molecular weight: 3000 PCD-2... Copolymer PCD of 1,10-decanediol / 1,4-butanediol = 10 / 90 (mol% ratio), number average molecular weight: 2500 PCD-3... Copolymer PCD of 1,10-decanediol / 1,4-butanediol = 10 / 90 (mol% ratio), number average molecular weight: 2000 PCD-4... Copolymer PCD of 1,10-decanediol / 1,4-butanediol = 30 / 70 (mol% ratio), number average molecular weight: 1000 PCD-5... Polyhexamethylene carbonate diol, number average molecular weight: 1000 PCD-6... Polyhexamethylene carbonate diol, number average molecular weight: 2000

[0059] [Experimental Example 1] A thermoplastic polyurethane was synthesized by the one-shot method according to the following procedure. 659.9 g of carbonate-based polyol (PCD-1) adjusted to 100°C was weighed into a 1-L tinplate and heated with stirring using a three-one motor until the temperature of the carbonate-based polyol reached 125°C. Next, 81.0 g of chain extender (1,4-BG) was added and mixed with stirring. 3.0 g of antioxidant (BASF: Irganox™ 1076) was then added and stirred for 2 minutes to obtain a mixed solution. 81.0 g of MDI melted at 70°C was added to the resulting mixed solution, which was then stirred and mixed uniformly. The mixture was then poured into a mold on a hot plate with a surface temperature controlled at 100°C. The resulting molded product was then placed in a 130°C oven for 3 hours, and then in a 100°C oven for 10 hours to complete the urethane reaction and obtain a thermoplastic polyurethane.

[0060] The composition ratio of the synthesized thermoplastic polyurethane was set to [MDI]:[1,4-BG]:[PCD-1] = 1.4:0.4:1.0 (molar ratio). With this blend, the hard segment content of the resulting thermoplastic polyurethane was 12% by mass. Furthermore, the NCO / OH equivalent ratio of the isocyanate group equivalent of the bifunctional aromatic isocyanate compound to the sum of the hydroxyl group equivalent of the bifunctional aliphatic alcohol and the hydroxyl group equivalent of the carbonate-based polyol was set to 1.0.

[0061] The resulting thermoplastic polyurethane-containing molding material was molded into a 2 mm thick sheet by heat press molding. First, prior to heat press molding, the resulting thermoplastic polyurethane was pre-dried under reduced pressure at 100 °C for 2 hours and dehydrated to form a molding material. Then, a release film, a fluorine-coated mold (150 × 150 × 2 mm), and the dehydrated thermoplastic polyurethane-containing molding material were placed on a SUS plate (200 × 200 × 2 mm), followed by the release film and SUS plate, and compression molding was performed using a mini test press (manufactured by Toyo Seiki Seisaku-sho, Ltd.). The temperature and pressure at this time were 220 °C, pre-compression 2.0 MPa × 1 minute, and main compression 13 MPa × 1 minute. The molded sheet was then cooled to 10-30 °C and main compression 13 MPa × 1 minute using a cooling mini test press (manufactured by Toyo Seiki Seisaku-sho, Ltd.) to obtain a molded sheet. The resulting molded sheet was annealed at 80 °C for 15 hours and used as a test sample for evaluation. The evaluation results of this test sample are shown in Table 2.

[0062] [Experimental Examples 2 to 10] Thermoplastic polyurethanes and molding materials containing the same were produced and test samples for evaluation were obtained in the same manner as in Example 1, except that the types and amounts of raw materials used were changed as shown in Table 1. The evaluation results of the test samples are shown in Table 2.

[0063]

[0064]

[0065] Tables 1 and 2 show that the molding materials of Experimental Examples 1 to 7 have superior flexibility after molding and even 60 days or more after molding compared to the molding materials of Experimental Examples 8 and 9. In contrast, Experimental Examples 8 and 9 were found to have inferior flexibility after molding and even 60 days or more after molding. Furthermore, a comparison of the molding material of Experimental Example 6 with the molding material of Experimental Example 9 revealed that when 1,10-decanediol was used as the soft segment of the thermoplastic polyurethane, flexibility after molding and even 60 days or more after molding was better than when 1,6-hexanediol was used. In particular, a comparison of Experimental Example 7 and Experimental Example 10 showed that when an aromatic diisocyanate was used as the hard segment of the thermoplastic polyurethane, better results were obtained in evaluations of flexibility, tensile strength at break, tensile elongation at break, and kink resistance compared to when an aliphatic diisocyanate was used as the hard segment of the thermoplastic polyurethane.

[0066] <Summary of the Embodiments> The above embodiments can be summarized as follows: However, the embodiments of the present invention are not limited to these.

[0067] [Embodiment A1] A catheter comprising a molding material containing a thermoplastic polyurethane having a hard segment containing a structural unit derived from an aromatic isocyanate compound and a soft segment containing a structural unit derived from a carbonate-based polyol, wherein the hardness of the molding material is A65 or less.

[0068] [Embodiment A2] The catheter according to embodiment A1, comprising a molding material containing 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more of the thermoplastic polyurethane. [Embodiment A3] The catheter according to embodiment A1 or A2, comprising a molding material containing 100% by mass or less, 98% by mass or less, or 95% by mass or less of the thermoplastic polyurethane.

[0069] [Embodiment A4] The catheter according to any one of Embodiments A1 to A3, wherein the hardness of the molding material is A50 or higher. [Embodiment A5] The catheter according to any one of Embodiments A1 to A4, wherein the tensile break strength of the molding material is 10 to 80 MPa. [Embodiment A6] The catheter according to any one of Embodiments A1 to A5, wherein the tensile break elongation of the molding material is 300 to 1000%. [Embodiment A7] The catheter according to any one of Embodiments A1 to A6, wherein the molding material has a tan δ of 1.20 to 2.00. [Embodiment A8] The catheter according to any one of Embodiments A1 to A7, wherein the thermoplastic polyurethane comprises a molding material containing a structural unit derived from 1,10-decanediol as a polyol constituent that constitutes the carbonate-based polyol.

[0070] [Embodiment A9] The catheter according to any one of Embodiments A1 to A8, wherein the thermoplastic polyurethane has a hard segment content of 23% by mass or less, 22% by mass or less, or 21% by mass or less, relative to the total amount of the hard segment and the soft segment. [Embodiment A10] The catheter according to any one of Embodiments A1 to A9, wherein the thermoplastic polyurethane has a hard segment content of 5% by mass or more, 10% by mass or more, 12% by mass or more, 14% by mass or more, 15% by mass or more, or 16% by mass or more, relative to the total amount of the hard segment and the soft segment.

[0071] [Embodiment A11] The catheter according to any one of Embodiments A1 to A10, wherein the hard segment comprises a structural unit derived from a chain extender. [Embodiment A12] The catheter according to Embodiment A11, wherein the structural unit derived from the chain extender comprises a structural unit derived from 1,4-butanediol.

[0072] [Embodiment A13] The catheter according to any one of Embodiments A1 to A12, which contains a thermoplastic polyurethane containing structural units derived from 1,4-butanediol as a polyol constituent that constitutes the carbonate-based polyol. [Embodiment A14] The catheter according to any one of Embodiments A1 to A13, wherein the carbonate-based polyol has a number average molecular weight of 500 to 4,000.

[0073] [Embodiment A15] The catheter according to any one of Embodiments A1 to A14, wherein the content of the hard segments is 5% by mass or more and 16% by mass or less relative to the total amount of the hard segments and the soft segments, and the number average molecular weight of the carbonate-based polyol is 2500 to 4000. [Embodiment A16] The catheter according to any one of Embodiments A1 to A15, wherein the content of the hard segments is 10% by mass or more and 23% by mass or less relative to the total amount of the hard segments and the soft segments, and the number average molecular weight of the carbonate-based polyol is 500 to 2400.

[0074] [Embodiment A17] The catheter of any one of Embodiments A1 to A16, wherein the molding material is a melt-molding material. [Embodiment A18] The catheter of any one of Embodiments A1 to A17, which is an indwelling catheter. [Embodiment A19] An indwelling catheter having a port site and a catheter, the catheter comprising the catheter of any one of Embodiments A1 to A17.

[0075] [Embodiment B1] A molding material having a hard segment containing a structural unit derived from an aromatic isocyanate compound and a soft segment containing a structural unit derived from a carbonate-based polyol, the molding material including a thermoplastic polyurethane containing a structural unit derived from 1,10-decanediol as a polyol constituent that constitutes the carbonate-based polyol.

[0076] [Embodiment B2] The molding material according to embodiment B1, wherein the water content is 2% by mass or less, 1.5% by mass or less, or 1% by mass or less. [Embodiment B3] The molding material according to embodiment B1 or B2, wherein the organic solvent content is 5% by mass or less, 3% by mass or less, or 1% by mass or less.

[0077] [Embodiment B4] The molding material according to any one of embodiments B1 to B3, wherein the content of the hard segment is 23% by mass or less, 22% by mass or less, or 21% by mass or less, relative to the total amount of the hard segment and the soft segment. [Embodiment B5] The molding material according to any one of embodiments B1 to B4, wherein the content of the hard segment is 5% by mass or more, 10% by mass or more, 12% by mass or more, 14% by mass or more, 15% by mass or more, or 16% by mass or more, relative to the total amount of the hard segment and the soft segment.

[0078] [Embodiment B6] The molding material of any one of Embodiments B1 to B5, wherein the hard segment comprises a structural unit derived from a chain extender. [Embodiment B7] The molding material of Embodiment B6, wherein the structural unit derived from the chain extender comprises a structural unit derived from 1,4-butanediol. [Embodiment B8] The molding material of any one of Embodiments B1 to B7, comprising a thermoplastic polyurethane comprising a structural unit derived from 1,4-butanediol as a polyol constituent that constitutes the carbonate-based polyol. [Embodiment B9] The molding material of any one of Embodiments B1 to B8, wherein the carbonate-based polyol has a number average molecular weight of 500 to 4,000.

[0079] [Embodiment B10] The molding material according to any one of Embodiments B1 to B9, wherein the content of the hard segments is 5% by mass or more and 16% by mass or less relative to the total amount of the hard segments and the soft segments, and the number average molecular weight of the carbonate polyol is 2500 to 4000. [Embodiment B11] The molding material according to any one of Embodiments B1 to B10, wherein the content of the hard segments is 10% by mass or more and 23% by mass or less relative to the total amount of the hard segments and the soft segments, and the number average molecular weight of the carbonate polyol is 500 to 2400.

[0080] [Embodiment B12] The molding material of any one of Embodiments B1 to B11, having a hardness of A50 to A74. [Embodiment B13] The molding material of any one of Embodiments B1 to B12, having a tensile break strength of 10 to 80 MPa. [Embodiment B14] The molding material of any one of Embodiments B1 to B13, having a tensile break elongation of 300 to 1000%. [Embodiment B15] The molding material of any one of Embodiments B1 to B14, having a tan δ of 1.20 to 2.00.

[0081] [Embodiment B16] The molding material of any one of Embodiments B1 to B15, comprising 50% by weight or more, 60% by weight or more, 70% by weight or more, or 80% by weight or more of the thermoplastic polyurethane. [Embodiment B17] The molding material of any one of Embodiments B1 to B16, comprising 100% by weight or less, 98% by weight or less, or 95% by weight or less of the thermoplastic polyurethane.

[0082] [Embodiment B18] The molding material according to any one of Embodiments B1 to B17, which is a melt-molding material. [Embodiment B19] A molded article comprising the molding material according to any one of Embodiments B1 to B18. [Embodiment B20] The molded article according to Embodiment B19, having a hardness of A50 to A74. [Embodiment B21] A catheter comprising the molding material according to any one of Embodiments B1 to B18 or the molded article according to Embodiment B19 or 20. [Embodiment B22] An indwelling catheter comprising the molding material according to any one of Embodiments B1 to B18 or the molded article according to Embodiment B19 or 20. [Embodiment B23] An indwelling catheter having a port site and a catheter, the catheter comprising the molding material according to any one of Embodiments B1 to B18 or the molded article according to Embodiment B19 or 20.

[0083] [Embodiment B24] A medical device component comprising the molding material according to any one of Embodiments B1 to B18 or the molded article according to Embodiment B19 or 20. [Embodiment B25] The medical device component according to Embodiment B24, which is a tube, a sealing material, or a packing. [Embodiment B26] A coating material comprising the molding material according to any one of Embodiments B1 to B18. [Embodiment B27] The coating material according to Embodiment B26, which is used for a medical device component.

[0084] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible within the scope of the effects of the invention. This application is based on Japanese Patent Application No. 2024-46049 filed on March 22, 2024, and Japanese Patent Application No. 2024-196115 filed on November 8, 2024, and is incorporated by reference in its entirety.

[0085] The catheter of the present invention can be particularly suitably used as an indwelling catheter. The molding material of the present invention can be suitably used as a catheter, a medical device component, a coating material, etc. Among these, the molding material of the present invention is suitable as a catheter, and is particularly suitable as an indwelling catheter.

Claims

1. A catheter comprising a molding material containing a thermoplastic polyurethane having a hard segment containing a structural unit derived from an aromatic isocyanate compound and a soft segment containing a structural unit derived from a carbonate-based polyol, wherein the hardness of the molding material is A65 or less.

2. The catheter according to claim 1, comprising a molding material containing 50% by mass or more and 100% by mass or less of said thermoplastic polyurethane.

3. The catheter according to claim 1, wherein the hardness of the molding material is A50 or higher.

4. The catheter according to claim 1, wherein the molding material has a tensile breaking strength of 10 to 80 MPa.

5. The catheter according to claim 1, wherein the tensile elongation at break of the molding material is 300 to 1000%.

6. The catheter according to claim 1, wherein the tan δ of the molding material is 1.20 to 2.

00.

7. The catheter of claim 1, wherein the molding material is a melt molding material.

8. The catheter according to any one of claims 1 to 7, which is an indwelling catheter.

9. An indwelling catheter having a port site and a catheter, the catheter comprising the catheter according to any one of claims 1 to 7.

10. A molding material having a hard segment containing a structural unit derived from an aromatic isocyanate compound and a soft segment containing a structural unit derived from a carbonate-based polyol, the thermoplastic polyurethane containing a structural unit derived from 1,10-decanediol as a polyol constituent that constitutes the carbonate-based polyol.

11. The molding material according to claim 10, wherein the water content is 2% by mass or less and the organic solvent content is 5% by mass or less.

12. The molding material according to claim 10, wherein the content of the hard segment is 5% by mass or more and 23% by mass or less relative to the total amount of the hard segment and the soft segment.

13. The molding material according to claim 10, wherein the hard segments contain structural units derived from a chain extender.

14. The molding material according to claim 10, having a hardness of A50 to A74.

15. The molding material according to claim 10, comprising 50% by mass or more and 100% by mass or less of the thermoplastic polyurethane.

16. The molding material according to any one of claims 10 to 15, which is a melt molding material.

17. A molded body comprising the molding material according to any one of claims 10 to 15.

18. A catheter comprising the molding material according to any one of claims 10 to 15.

19. An indwelling catheter comprising the molding material of any one of claims 10 to 15.

20. An indwelling catheter having a port site and a catheter, the catheter comprising the molding material of any one of claims 10 to 15.

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