Medical device

Abstract

Provided is a medical device having excellent surface lubricity and durability.　This medical device comprises a base material layer and a surface lubricating layer supported on at least a part of the base material layer, wherein the value of a component having high molecular mobility in spin-spin relaxation time (T2) obtained using a pulse NMR CPMG method in the surface lubricating layer is greater than 18 ms.

Description

medical equipment

[0001] The present invention relates to a medical device having excellent surface lubricity and durability.

[0002] Medical devices inserted into living bodies, such as catheters, guidewires, and indwelling needles, are required to exhibit excellent lubricity in order to reduce tissue damage to blood vessels and improve operability for the surgeon. For this reason, methods of coating the surface of a substrate layer with a hydrophilic polymer having lubricity have been developed and put into practical use. In such medical devices, elution or peeling of the hydrophilic polymer from the surface of the substrate layer poses problems in terms of maintaining safety and operability. Therefore, coatings with hydrophilic polymers are required to have not only excellent lubricity but also durability against loads such as abrasion and abrasion.

[0003] From this perspective, Japanese Patent Laid-Open No. 8-33704 (corresponding to the specification of U.S. Pat. No. 005,670,558) discloses a medical device in which a surface lubricating layer is formed on the surface of the substrate by dissolving a water-soluble or water-swellable polymer in a solvent that swells the substrate of the medical device to prepare a polymer solution, immersing the substrate of the medical device in this polymer solution to cause it to swell, and then crosslinking or polymerizing the polymer on the surface of the substrate. According to the technology disclosed in Japanese Patent Laid-Open No. 8-33704, a surface lubricating layer that exhibits relatively good lubricity can be fixed to the substrate.

[0004] Japanese Patent Laid-Open Publication No. 8-33704 discloses that it is preferable to use a block copolymer consisting of a hydrophilic portion that exhibits lubricity and a portion having an epoxy group as the water-soluble or water-swellable polymer. When such a block copolymer is used, the epoxy groups of the block copolymer can be crosslinked by heating, forming a surface lubricating layer that is relatively resistant to peeling. However, good lubricity and excellent durability are in a trade-off relationship, and a technology that can achieve both good lubricity and excellent durability is needed.

[0005] The present invention has been made in view of the above circumstances, and aims to provide a medical device having a surface lubricating layer that has both excellent surface lubricity and excellent durability.

[0006] The present inventors have conducted extensive research to solve the above problems, and as a result have discovered that the above object can be achieved by a medical device having a surface lubricating layer whose results measured by the CPMG method of pulsed NMR analysis are greater than a predetermined value, thereby completing the present invention.

[0007] That is, the above objects can be achieved by the present invention having the following configuration, and the present invention includes the following aspects and configurations.

[0008] One aspect of the present invention is a medical device comprising a base layer and a surface lubricating layer carried on at least a portion of the base layer, wherein the spin-spin relaxation time (T ２ ) is a medical device in which the value of the component with high molecular mobility is greater than 18 ms.

[0009] 2. The medical device described in 1. above is characterized in that the spin-spin relaxation time (T ２ ) is preferably 19 ms or more.

[0010] 3. The medical device according to the above 1. or 2. is characterized in that the spin-spin relaxation time (T ２ In the above-mentioned polymer, the proportion of the component with high molecular mobility to the total amount of the component with high molecular mobility and the component with low molecular mobility is preferably 80% or more.

[0011] 4. The medical device according to any one of 1. to 3. above preferably has a sliding resistance value of 12 gf or less at the 30th time in a sliding resistance evaluation test.

[0012] 5. In the medical device according to any one of 1. to 4. above, in a sliding resistance evaluation test, the increase (gf) obtained by subtracting the sliding resistance value at the 5th time from the sliding resistance value at the 30th time is preferably 1.2 gf or less.

[0013] 6. The medical device according to any one of 1. to 5. above is preferably a catheter, a guidewire, or an indwelling needle.

[0014] Fig. 1 is a partial cross-sectional view schematically showing the surface layer structure of a representative embodiment of a medical device according to the present invention, and Fig. 2 is a partial cross-sectional view schematically showing an example of a different surface layer structure as an application example of the embodiment of Fig. 1.

[0015] A medical device according to one aspect of the present invention is a medical device comprising a base layer and a surface lubricating layer supported on at least a portion of the base layer, wherein the surface lubricating layer has a spin-spin relaxation time (T ２ The value of the component with high molecular mobility in the above-described structure is hereinafter also referred to as "the medical device according to the present invention" or "the medical device."

[0016] Herein, the structural unit (A) derived from a reactive monomer having an epoxy group is also simply referred to as the "structural unit (A) according to the present invention" or "structural unit (A)." Herein, the structural unit (B) derived from a hydrophilic monomer is also simply referred to as the "structural unit (B) according to the present invention" or "structural unit (B)." Herein, a block copolymer having structural units (A) and (B) is also simply referred to as the "block copolymer according to the present invention," "hydrophilic block copolymer," or "block copolymer."

[0017] In this specification, when a certain structural unit is defined as being "derived from" a certain monomer, it means that the structural unit is a divalent structural unit generated by cleavage of one of the polymerizable unsaturated double bonds of the corresponding monomer.

[0018] As used herein, the term "(meth)acrylic" encompasses both acrylic and methacrylic. Thus, for example, the term "(meth)acrylic acid" encompasses both acrylic acid and methacrylic acid. Similarly, the term "(meth)acryloyl" encompasses both acryloyl and methacryloyl. Thus, for example, the term "(meth)acryloyl group" encompasses both acryloyl and methacryloyl groups. Similarly, the term "(meth)acrylate" encompasses both acrylate and methacrylate. For example, the term "alkoxyalkyl(meth)acrylate" encompasses both alkoxyalkylacrylate and alkoxyalkylmethacrylate.

[0019] In this specification, the term "X to Y" indicating a range includes both X and Y and means "X or more and Y or less." Furthermore, "X and / or Y" refers to at least one of X and Y, and encompasses X alone, Y alone, and a combination of X and Y. Throughout this specification, singular expressions should be understood to include the plural form unless otherwise specified. Therefore, singular articles (e.g., "a," "an," "the," etc. in English) should be understood to include the plural form unless otherwise specified. Furthermore, terms used in this specification should be understood to have the meaning commonly used in the art unless otherwise specified. Therefore, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the art to which this invention belongs. In the event of a conflict, this specification (including definitions) shall prevail. The present invention is not limited to the following embodiments and can be variously modified within the scope of the claims. Furthermore, unless otherwise specified, "%" refers to mass concentration ("mass %").

[0020] Unless otherwise specified, the operations and measurements of physical properties are carried out at room temperature (20 to 25°C) and a relative humidity of 40 to 50% RH.

[0021] The medical device according to the present invention has a base layer and a surface lubricating layer carried on at least a part of the base layer, and the spin-spin relaxation time (T ２ ) the value of the component with high molecular mobility is greater than 18 ms. The medical device according to the present invention having this configuration has excellent lubricity and durability. This is because the spin-spin relaxation time (T ２ This is thought to be mainly due to the fact that the value of the component with high molecular mobility in the surface lubricating layer is greater than 18 ms, i.e., the high mobility of the molecules (polymers) contained in the surface lubricating layer. A surface lubricating layer with high molecular mobility spreads its molecules when it comes into contact with water, allowing it to contain a large amount of water within the layer, thereby achieving good lubrication. Furthermore, medical devices intended for insertion into living bodies such as blood vessels generally experience increased frictional resistance when in contact with the inner surfaces of sheaths, catheters, etc. through which they pass. However, the medical device of the present invention has good surface lubricity, making it less susceptible to friction and other effects when in contact with the inner surfaces of sheaths, catheters, etc. through which they pass. This suppresses wear and abrasion on the surface of the medical device of the present invention, allowing the surface lubricating layer to be maintained for a longer period of time, which is thought to result in excellent durability. Note that the above mechanism is speculation and does not limit the technical scope of the present invention.

[0022] Hereinafter, embodiments of the present invention will be described. Note that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the claims. Furthermore, the embodiments described in this specification can be arbitrarily combined to form other embodiments. The dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions. Furthermore, when embodiments of the present invention are described with reference to the drawings, the same elements are given the same reference numerals in the description of the drawings, and duplicate explanations will be omitted.

[0023] [Medical Device] The medical device according to the present invention comprises a base layer and a surface lubricating layer carried on at least a part of the base layer. The surface lubricating layer has a spin-spin relaxation time (T ２ The value of the component with high molecular mobility in the lubricating oil is greater than 18 ms. According to the present invention, a medical device that combines excellent surface lubricity and excellent durability can be provided.

[0024] Hereinafter, preferred embodiments of the medical device according to the present invention will be described with reference to the accompanying drawings.

[0025] Fig. 1 is a partial cross-sectional view schematically showing the surface layer structure of a representative embodiment of a medical device according to the present invention. Fig. 2 is a partial cross-sectional view schematically showing a different example of the surface layer structure as an application example of the embodiment shown in Fig. 1. Note that the reference symbols in Fig. 1 and Fig. 2 respectively represent the following: Reference symbol 1 represents a substrate layer; Reference symbol 1a represents a substrate layer core; Reference symbol 1b represents a substrate surface layer; Reference symbol 2 represents a surface lubricating layer; and Reference symbol 10 represents a medical device according to the present invention.

[0026] As shown in Figures 1 and 2, the medical device 10 of this embodiment comprises a base layer 1 and a surface lubricating layer 2 containing a block copolymer provided on at least a portion of the base layer 1 (the figure shows an example in which the surface lubricating layer 2 is provided on the entire (whole) surface of the base layer 1 in the drawing). In Figures 1 and 2, the surface lubricating layer 2 is formed on both sides of the base layer 1, but the present invention is not limited to the above form, and may be any form, such as a form in which the surface lubricating layer 2 is formed on one side of the base layer 1; a form in which the surface lubricating layer 2 is formed on a portion of one or both sides of the base layer 1, etc.

[0027] Below, the medical device will be described in detail for each of its constituent parts.

[0028] <Substrate Layer (Substrate)> The substrate layer used in this embodiment may be made of any material, and the material is not particularly limited. Specifically, materials constituting the substrate layer 1 include metal materials, polymer materials, and ceramics.

[0029] Among the materials constituting the base layer 1, the metal material is not particularly limited, and metal materials commonly used for medical devices such as catheters, guidewires, and indwelling needles can be used. Specific examples include various stainless steels such as SUS304, SUS314, SUS316, SUS316L, SUS420J2, and SUS630, as well as gold, platinum, silver, copper, nickel, cobalt, titanium, iron, aluminum, tin, and various alloys such as nickel-titanium alloys, nickel-cobalt alloys, cobalt-chromium alloys, and zinc-tungsten alloys. These may be used alone or in combination of two or more. The metal material may be appropriately selected from those optimal for the base layer of the intended use, such as a catheter, guidewire, or indwelling needle.

[0030] Furthermore, among the materials constituting the base layer 1, the polymer material (resin material or elastomer material) is not particularly limited, and may be a polymer material commonly used in medical devices such as catheters, introducers, guidewires, indwelling needles, etc. Specific examples include polyamide resin, polyolefin resin such as polyethylene resin or polypropylene resin, modified polyolefin resin, cyclic polyolefin resin, epoxy resin, polyurethane resin, diallyl phthalate resin (allyl resin), polycarbonate resin, fluororesin (e.g., polytetrafluoroethylene), amino resin (urea resin, melamine resin, benzoguanamine resin), polyester resin such as polyethylene terephthalate resin or polybutylene terephthalate resin, styrene resin, acrylic resin, polyacetal resin, vinyl acetate resin, phenolic resin, vinyl chloride resin, silicone resin (silicon resin), polyether resin, polyimide resin, etc.

[0031] Thermoplastic elastomers such as polyurethane elastomers, polyester elastomers, and polyamide elastomers (nylon elastomers) can also be used as materials for the base layer, with polyester elastomers and polyamide elastomers being preferred.

[0032] These polymeric materials may be used alone, or as a mixture of two or more kinds, or as a copolymer of two or more kinds of monomers constituting any of the above-mentioned resins or elastomers. As the polymeric material, a polymeric material that is optimal for the substrate layer of the intended use, such as a catheter, guide wire, indwelling needle, etc. may be appropriately selected.

[0033] The shape of the substrate layer 1 is not particularly limited, and may be appropriately selected depending on the mode of use, such as a sheet, a wire, a rod, or a tube.

[0034] Here, the entire substrate layer 1 may be made of any of the above materials. The substrate layer 1 may be a multilayer structure formed by laminating different materials in multiple layers, or a structure in which components formed of different materials are joined together for each portion of the medical device. Alternatively, as shown in FIG. 2, the substrate may have a structure in which the surface of a substrate layer core portion 1a formed of any of the above materials is coated with any of the other materials by an appropriate method to form a substrate surface layer 1b. Examples of the latter case include a substrate in which the surface of a substrate layer core portion 1a formed of a resin material or the like is coated with a metal material by an appropriate method (conventionally known methods such as plating, metal vapor deposition, sputtering, etc.) to form a substrate surface layer 1b; a substrate in which the surface of a substrate layer core portion 1a formed of a hard reinforcing material such as a metal material or a ceramic material is coated with a polymer material that is softer than the metal reinforcing material by an appropriate method (conventionally known methods such as dipping, spraying, coating / printing, etc.); or a substrate in which the reinforcing material forming the substrate layer core portion 1a and the polymer material are combined to form a substrate surface layer 1b. The base layer core 1a may be a multilayer structure formed by laminating multiple layers of different materials, or a structure in which different parts of the medical device are joined together. A separate middle layer (not shown) may be formed between the base layer core 1a and the base surface layer 1b. The base surface layer 1b may also be a multilayer structure formed by laminating multiple layers of different materials, or a structure in which different parts of the medical device are joined together.

[0035] <Surface lubricating layer (coating layer)> In the medical device of the present invention, the surface lubricating layer is supported on at least a part of the base layer 1. Here, the reason why the surface lubricating layer 2 is supported on at least a part of the surface of the base layer 1 is that in medical devices such as catheters, guide wires, and indwelling needles, which are used for this purpose, it is not necessary for all surfaces (the entire surface) of these medical devices to have lubricity when wet, and the surface lubricating layer only needs to be supported on the surface portion (sometimes a part or sometimes all) that is required to have lubricity when wet. Therefore, as described above, the surface lubricating layer includes a form formed to cover both sides of the base layer as shown in Figures 1 and 2; a form formed to cover only one side of the base layer; a form formed to cover parts of both sides of the base layer in the same or different forms; a form formed to cover part of one side of the base layer, etc.

[0036] (spin-spin relaxation time (T ２ In the medical device of the present invention, the surface lubricating layer carried on at least a part of the base layer 1 has a spin-spin relaxation time (T ２ ) the value of the component with high molecular mobility is greater than 18 ms. When the value of the component with high molecular mobility is greater than 18 ms, the surface lubricating layer achieves both good lubricity and excellent durability.

[0037] Here, pulsed NMR (also called TD-NMR (time domain NMR)) is a method for measuring the molecular mobility, which is closely related to １ H nucleus relaxation time (spin-lattice relaxation time (T １ ), and the spin-spin relaxation time (T ２ )) is a technique that can rapidly measure the spin-spin relaxation time (T ２) is used. According to the CPMG method of pulsed NMR, a high-frequency magnetic field is applied as a pulse to a measurement object placed in an NMR tube, thereby tilting the magnetization vector, and the mobility of molecules in a solution can be evaluated from the time until the x and y components disappear (= relaxation time). Here, it is known that the spin-spin relaxation time is shorter the lower the molecular mobility, and longer the higher the molecular mobility. Note that the method for measuring the spin-spin relaxation time and the method for calculating the values ​​of the components with high and low molecular mobility in the spin-spin relaxation time are the same as those described in the section "Measurement of Spin-Spin Relaxation Time" in the Examples.

[0038] The surface lubricating layer in the medical device according to one embodiment has a spin-spin relaxation time (T ２ The value of the component with high molecular mobility in the above range is preferably 19 ms or more, more preferably 19.5 ms or more, and even more preferably 20 ms or more. By having the value of the component with high molecular mobility in the above range, the surface lubricating layer can contain more water, resulting in better lubrication.

[0039] In the surface lubricating layer according to one embodiment, the spin-spin relaxation time (T ２ The proportion of the component with high molecular mobility in the spin-spin relaxation time is preferably 70% or more, more preferably 75% or more, and even more preferably 80% or more, relative to the total amount of the high and low molecular mobility components. By having the proportion of the component with high molecular mobility within the above range, the surface lubricating layer will have better lubrication. Note that the method for calculating the proportion of the high component relative to the total amount of the component with high molecular mobility and the component with low molecular mobility in the spin-spin relaxation time, and the method for calculating the low component relative to the total amount, will be the same as the method described in the section [Measurement of Spin-Spin Relaxation Time] in the Examples.

[0040] In the surface lubricating layer according to one embodiment, the spin-spin relaxation time (T ２The value of the component with low molecular mobility in (2) may be 2 ms or less, 1.5 ms or less, less than 1.3 ms, or 1.2 ms or less.

[0041] (Sliding resistance) In a medical device according to one embodiment of the present invention, the sliding resistance value at the 30th time is preferably 12 gf or less, more preferably 11 gf or less, and even more preferably 10 gf or less, of the sliding resistance values ​​measured for each of a total of 30 sliding times in a sliding resistance test. When the sliding resistance value at the 30th time in the sliding resistance test is within the above range, the medical device according to the present invention has better surface lubricity. Note that the method for measuring the sliding resistance value at the 30th time in the sliding resistance test is the method described in the section "Evaluation of sliding resistance" in the Examples.

[0042] In another embodiment of the medical device, when the sliding resistance value at the 30th time is 12 gf or less, the spin-spin relaxation time (T ２ The value of the component with high molecular mobility in the sliding resistance test is preferably greater than 16 ms, more preferably 17 ms or more, even more preferably 18 ms or more, and particularly preferably 19 ms or more. ２ When the value of the component with high molecular mobility in the above range, the surface lubricity and durability of the medical device according to the other embodiment are improved.

[0043] In a medical device according to one embodiment of the present invention, the sliding resistance value measured for each of 30 sliding runs in a sliding resistance test is preferably 1.2 gf or less, more preferably 1.1 gf or less, even more preferably 1 gf or less, and particularly preferably 0.9 gf or less, when the sliding resistance value at the 30th run is subtracted from the sliding resistance value at the 5th run. The lower limit of this increase is not particularly limited, but may be approximately 0 gf. By ensuring that this increase is within the above range, the medical device according to the present invention will have superior durability. The method for measuring the increase, when the sliding resistance value at the 30th run is subtracted from the sliding resistance value at the 5th run, is the same as that described in the "Evaluation of Sliding Resistance" section of the Examples.

[0044] In another embodiment, the medical device has a spin-spin relaxation time (T) measured by the CPMG method of pulsed NMR when the increase (gf) obtained by subtracting the sliding resistance value at the fifth time from the sliding resistance value at the 30th time is 1.2 gf or less in the sliding resistance values ​​measured in a total of 30 times in a sliding resistance test. ２ The value of the component with high molecular mobility in the sliding resistance test (gf) is preferably greater than 16 ms, more preferably 17 ms or more, even more preferably 18 ms or more, and particularly preferably 19 ms or more. ２ When the value of the component with high molecular mobility in the above range is within the above range, the surface lubricity and durability of the medical device according to another embodiment will be superior.

[0045] (Components of the surface lubricating layer) The surface lubricating layer in the medical device according to one embodiment may contain a block copolymer. Here, the block copolymer may have a structural unit (A) derived from a reactive monomer having an epoxy group and a structural unit (B) derived from a hydrophilic monomer.

[0046] The reactive monomer having epoxy group that constitutes block copolymer has epoxy group as reactive group.By introducing the structural unit (A) derived from this reactive monomer into block copolymer, epoxy group ring-opens, and the cross-linking (bonding) between block copolymers progresses, and the film strength of surface lubrication layer increases.In addition, when substrate is resin material, the cross-linking (bonding) between block copolymer and substrate can also occur due to the open epoxy group.

[0047] The reactive monomer constituting the block copolymer is not particularly limited as long as it has an epoxy group, and known compounds can be used. Among them, the reactive monomer having an epoxy group preferably includes at least one selected from the group consisting of glycidyl acrylate, glycidyl methacrylate (GMA), 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, β-methylglycidyl methacrylate, and allyl glycidyl ether, because this makes it easier to control the crosslinking or polymerization of the block copolymer.

[0048] Among these, glycidyl (meth)acrylate is more preferred, and glycidyl methacrylate is particularly preferred, in consideration of the ability to further promote the crosslinking reaction and ease of production. That is, in a more preferred embodiment of the present invention, the reactive monomer having an epoxy group is at least one of glycidyl acrylate and glycidyl methacrylate. Furthermore, in a particularly preferred embodiment of the present invention, the reactive monomer having an epoxy group is glycidyl methacrylate.

[0049] The reactive monomers may be used alone or in combination of two or more. That is, the structural unit (A) derived from the reactive monomer may be a homopolymer type composed of one type of reactive monomer alone, or a copolymer type composed of two or more types of the reactive monomers. When two or more types are used, the structural unit (A) may be in the form of a block copolymer or a random copolymer.

[0050] The hydrophilic monomers constituting the block copolymers swell when in contact with body fluids or aqueous solvents, thereby imparting lubricity (surface lubricity) to medical devices. Therefore, by introducing the structural unit (B) derived from such a hydrophilic monomer into the block copolymer, the lubricity (surface lubricity) of the medical device can be improved, thereby reducing friction when the medical device comes into contact with a lumen wall such as a blood vessel wall.

[0051] The hydrophilic monomer constituting the block copolymer is not particularly limited as long as it has the above-mentioned properties, and known compounds can be used, such as acrylamide and its derivatives, vinylpyrrolidone, acrylic acid, methacrylic acid and their derivatives, polyethylene glycol acrylate and its derivatives, monomers having sugars or phospholipids in the side chains, and water-soluble monomers such as maleic anhydride. More specifically, acrylic acid, methacrylic acid, N-methylacrylamide, N,N-dimethylacrylamide (DMAA), acrylamide, acryloylmorpholine, N,N-dimethylaminoethyl acrylate, N-vinylpyrrolidone, 2-methacryloyloxyethyl phosphorylcholine, 2-methacryloyloxyethyl-D-glycoside, 2-methacryloyloxyethyl-D-mannoside, vinyl methyl ether, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, 1-chloro-2-hydroxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, neopentyl glycol mono(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, 2-hydroxy-3-phenyloxypropyl(meth)acrylate, 4-hydroxycyclohexyl(meth)acrylate, 2-hydroxy-3-phenyloxy(meth)acrylate, 4-hydroxycyclohexyl(meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, poly(ethylene glycol) methyl ether acrylate, and poly(ethylene glycol) methyl ether methacrylate.From the viewpoints of imparting excellent lubricity, ease of synthesis, and operability, the hydrophilic monomer preferably includes at least one selected from the group consisting of N,N-dimethylacrylamide, acrylamide, 2-hydroxyethyl methacrylate, and N-vinylpyrrolidone.

[0052] Among these, in consideration of the imparting of excellent lubricity, ease of synthesis, and operability, N,N-dimethylacrylamide, acrylamide, or 2-hydroxyethyl methacrylate are more preferred, and N,N-dimethylacrylamide is particularly preferred. That is, in a more preferred embodiment of the present invention, the hydrophilic monomer is at least one selected from the group consisting of N,N-dimethylacrylamide, acrylamide, and 2-hydroxyethyl methacrylate. Furthermore, in a particularly preferred embodiment of the present invention, the hydrophilic monomer is N,N-dimethylacrylamide.

[0053] The hydrophilic monomers may be used alone or in combination of two or more. That is, the structural unit (B) derived from the hydrophilic monomer may be a homopolymer type composed of one hydrophilic monomer alone, or a copolymer type composed of two or more of the hydrophilic monomers. When two or more types are used, the structural unit (B) may be in the form of a block copolymer or a random copolymer.

[0054] The block copolymer has a structural unit (A) derived from the reactive monomer and a structural unit (B) derived from the hydrophilic monomer. The ratio of the structural unit (A) to the structural unit (B) is not particularly limited as long as the above-mentioned effects are achieved. Considering good lubricity, lubrication maintenance, surface lubrication layer strength, and bonding to the substrate, the ratio of the structural unit (A) to the structural unit (B) (molar ratio of structural unit (A): structural unit (B)) is preferably 1:2 to 1:20, and more preferably 1:10 to 1:14. Within this range, the surface lubrication layer can exhibit sufficient lubricity due to the structural unit (B), and can exhibit sufficient surface lubrication layer strength, bonding to the substrate, and durability due to the structural unit (A). The molar ratio of the structural unit (A): structural unit (B) can be controlled by adjusting the charge ratio (molar ratio) of each monomer during the production stage of the block copolymer. Therefore, the charging ratio (molar ratio) of the reactive monomer having an epoxy group to the hydrophilic monomer in the production stage of the block copolymer is preferably 1:2 to 1:20, and more preferably 1:10 to 1:14. The molar ratio of the structural unit (A):structural unit (B) can be determined, for example, by NMR measurement ( １ H-NMR measurement, １３ This can be confirmed by performing spectroscopy (e.g., C-NMR measurement).

[0055] The block copolymer according to the present invention essentially contains the structural unit (A) and the structural unit (B), but may contain other structural units in addition to these structural units. When the block copolymer contains other structural units, examples of such other structural units include adipic acid, glutaric acid, triethylene glycol, and tripropylene glycol. The monomers constituting the other structural units may be used alone or in combination of two or more. That is, the other structural units may be homopolymers composed of a single structural unit, or copolymers composed of two or more structural units. When two or more monomers are used to constitute the other structural units, the segments composed of the monomers may be in the form of a block copolymer, a random copolymer, or an alternating copolymer.

[0056] When the block copolymer according to the present invention contains other structural units, the content of the other structural units is preferably more than 0 mol% and less than 5 mol% relative to all structural units constituting the block copolymer. That is, in the block copolymer according to the present invention, when the total of all structural units constituting the block copolymer is taken as 100 mol%, the total content of the structural units (A) and (B) is preferably 95 mol% or more (upper limit: less than 100 mol%). More preferably, the block copolymer according to the present invention is substantially composed of the structural units (A) and (B) (the content of the other structural units is more than 0 mol% and less than 5 mol%). In this form, the block copolymer according to the present invention can achieve a good balance between the durability provided by the structural unit (A) and the lubricity (surface lubricity) provided by the structural unit (B). Preferably, the block copolymer according to the present invention does not contain the other structural units (the content of the other structural units is 0 mol%).

[0057] The composition of each structural unit (structural units (A) and (B) and other structural units) can be measured by a known method. For example, １ The composition (molar ratio) of the structural units can be determined by measuring the integral ratio of the intensities of each signal in the H-NMR spectrum.

[0058] In one embodiment of the present invention, the block copolymer according to the present invention is essentially composed of a structural unit (A) derived from at least one reactive monomer selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, β-methylglycidyl methacrylate, and allyl glycidyl ether, and a structural unit (B) derived from at least one hydrophilic monomer selected from the group consisting of N,N-dimethylacrylamide, acrylamide, 2-hydroxyethyl methacrylate, and N-vinylpyrrolidone, or is composed only of the structural unit (A) and the structural unit (B).

[0059] In one embodiment of the present invention, the block copolymer according to the present invention is essentially composed of a structural unit (A) derived from at least one reactive monomer of glycidyl acrylate and glycidyl methacrylate, and a structural unit (B) derived from at least one hydrophilic monomer selected from the group consisting of N,N-dimethylacrylamide, acrylamide, and 2-hydroxyethyl methacrylate, or is composed only of the structural unit (A) and the structural unit (B).

[0060] In one embodiment of the present invention, the block copolymer according to the present invention is essentially composed of a structural unit (A) derived from glycidyl methacrylate (a reactive monomer having an epoxy group) and a structural unit (B) derived from N,N-dimethylacrylamide (a hydrophilic monomer), or is composed only of the structural unit (A) and the structural unit (B).

[0061] The weight-average molecular weight of the block copolymer is preferably 10,000 to 10,000,000 from the viewpoint of solubility. The weight-average molecular weight of the block copolymer is more preferably 100,000 to 5,000,000 from the viewpoint of ease of preparation of the coating liquid. In this specification, the "weight-average molecular weight" is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0062] The method for producing the block copolymer is not particularly limited, and can be prepared by applying conventional polymerization methods such as living radical polymerization, polymerization using a macroinitiator, and polycondensation. Among these, living radical polymerization or polymerization using a macroinitiator is preferred because it allows for easy control of the molecular weight and molecular weight distribution of the structural units (portions) derived from the reactive monomer and the structural units (portions) derived from the hydrophilic monomer. The living radical polymerization method is not particularly limited, and examples thereof include methods described in JP-A-11-263819, JP-A-2002-145971, JP-A-2006-316169, and the like, as well as atom transfer radical polymerization (ATRP), which can be applied in the same manner or with appropriate modifications. Furthermore, in polymerization methods using a macroinitiator, for example, a block copolymer having a hydrophilic moiety and a reactive moiety can be prepared by preparing a macroinitiator having a reactive moiety with a reactive functional group and a radically polymerizable group such as a peroxide group, and then polymerizing the macroinitiator with a monomer for forming the hydrophilic moiety.

[0063] After polymerization, the block copolymer is preferably purified by a common purification method such as reprecipitation, dialysis, ultrafiltration, or extraction.

[0064] The surface lubricating layer may contain other components in addition to the block copolymer. The other components are not particularly limited and may be selected appropriately depending on, for example, the intended use of the medical device.

[0065] <Method for manufacturing medical device> The surface lubricating layer of the above medical device may be formed using any method as long as it is possible to form a coating film containing a block copolymer on a base layer, but it is preferably formed by applying a coating liquid containing a block copolymer and a solvent onto the base layer.

[0066] Therefore, another aspect of the present invention is a medical device comprising a base layer and a surface lubricating layer carried on at least a portion of the base layer, wherein the spin-spin relaxation time (T ２The present invention provides a method for manufacturing a medical device in which the value of a component with high molecular mobility in the above-described structure is greater than 18 ms. Hereinafter, the method for manufacturing a medical device having the above-described configuration will be referred to as a "manufacturing method according to one embodiment" or simply as a "manufacturing method."

[0067] A manufacturing method according to one embodiment includes the steps of: preparing a coating liquid containing a block copolymer having a structural unit (A) derived from a reactive monomer having an epoxy group and a structural unit (B) derived from a hydrophilic monomer, and a solvent ((I) preparation step); applying the coating liquid onto a substrate layer ((II) application step); and heat treating the substrate to which the coating liquid has been applied ((III) heat treatment step). A medical device obtained by this manufacturing method not only has excellent lubricity, but also durability against loads such as abrasion and abrasion.

[0068] In other words, the medical device according to one embodiment of the present invention is a medical device manufactured by a manufacturing method including the steps of: preparing a coating liquid containing a block copolymer having a structural unit (A) derived from a reactive monomer having an epoxy group and a structural unit (B) derived from a hydrophilic monomer, and a solvent ((I) preparation step); applying the coating liquid onto a substrate layer ((II) application step); and heat treating the substrate coated with the coating liquid ((III) heat treatment step).

[0069] In the method for producing a medical device according to one embodiment of the present invention, the terms block copolymer, substrate, etc. are the same as those described in the above sections, and therefore will not be explained here.

[0070] The above steps (I) to (III) will be described below.

[0071] [(I) Preparation Step] In this step, a coating liquid containing a block copolymer and a solvent is prepared. Here, in this step, the coating liquid may be prepared by mixing the block copolymer and the solvent to prepare the coating liquid. Alternatively, a coating liquid containing the block copolymer and the solvent may be purchased and used.

[0072] A preferred embodiment of preparing a coating liquid by mixing a block copolymer and a solvent will be described in detail below.

[0073] (Preparation of Coating Liquid) A coating liquid is prepared using the block copolymer and solvent. The method for adding the block copolymer and solvent is not particularly limited. The components may be added all at once or separately, stepwise or continuously. The method for mixing the components is also not particularly limited, and known methods can be used. From the viewpoint of facilitating the preparation of a uniform solution (coating liquid), it is preferable to add the block copolymer sequentially to the solvent. The addition may be carried out while stirring, if necessary.

[0074] The solvent used to prepare the coating liquid is not particularly limited as long as it can dissolve the block copolymer (and other components, if used), and is appropriately selected depending on the type of block copolymer (and other components, if used). Specific examples of solvents for the coating liquid include alcohol-based solvents such as methanol, ethanol, isopropyl alcohol, butanol, and ethylene glycol; ketone-based solvents such as acetone, methyl ethyl ketone, and cyclohexanone; ester-based solvents such as ethyl acetate and butyl acetate; ether-based solvents such as tetrahydrofuran (THF), butyl ether, and dioxane; aliphatic hydrocarbon-based solvents such as hexane and heptane; aromatic hydrocarbon-based solvents such as benzene and toluene; dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and the like. These solvents may be used alone or in combination (in the form of a mixed solvent) of two or more types.

[0075] The concentration of the block copolymer in the coating solution is not particularly limited. From the viewpoint of further improving the coatability and the lubricity and durability of the surface lubrication layer, the concentration of the block copolymer in the coating solution is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, and particularly preferably 3 to 10% by mass. If the concentration of the block copolymer is within the above range, the lubricity and durability of the resulting surface lubrication layer can be fully exhibited. Furthermore, a uniform surface lubrication layer of the desired thickness can be easily obtained with a single coating, and the viscosity of the solution is within an appropriate range, which is preferable in terms of operability (e.g., ease of coating) and production efficiency. However, even if the concentration is outside the above range, it can be fully used as long as it does not affect the effects of the present invention.

[0076] [(II) Coating Step] In this step, the coating liquid prepared in the above (I) Preparation Step is applied onto the substrate layer of the medical device to form a coating film (coating layer) on the substrate layer.

[0077] The substrate layer may be made of any material, for example, metal materials, polymer materials, ceramics, etc. Specific examples of these materials are the same as those described above in the section <Substrate Layer (Substrate)>, so detailed description will be omitted here.

[0078] The method for applying (coating) the coating liquid onto the substrate layer of the medical device is not particularly limited, and any conventionally known method can be used, such as application / printing, immersion (dipping, dip coating), spraying, spin coating, mixed solution impregnated sponge coating, bar coating, die coating, reverse coating, comma coating, gravure coating, doctor knife, etc. Of these, the immersion method (dipping, dip coating) is preferred.

[0079] When forming a surface lubricating layer on a thin and narrow inner surface of a catheter, guide wire, injection needle, etc., the substrate layer may be immersed in the coating solution and the pressure in the system may be reduced to degas the solution. By reducing the pressure and degassing the solution, the solution can be quickly penetrated into the thin and narrow inner surface, facilitating the formation of the surface lubricating layer.

[0080] Furthermore, when forming a surface lubricating layer only on a portion of the substrate layer, only a portion of the substrate layer can be immersed in a coating liquid and the coating liquid can be coated onto that portion of the substrate layer, thereby forming a surface lubricating layer on the desired surface portion of the substrate layer.

[0081] When it is difficult to immerse only a portion of the substrate layer in the coating liquid, the surface portion of the substrate layer that does not need to form a surface lubricating layer can be protected (coated, etc.) with a suitable removable (attachable) member or material, and then the substrate layer can be immersed in the coating liquid to coat the substrate layer with the coating liquid. After that, the protective member (material) on the surface portion of the substrate layer that does not need to form a surface lubricating layer can be removed, and then the substrate layer can be reacted by heat treatment or the like to form a surface lubricating layer on the desired surface portion of the substrate layer. However, the present invention is not limited to these formation methods, and a surface lubricating layer can be formed using any conventionally known method. For example, when it is difficult to immerse only a portion of the substrate layer in the coating liquid, other coating methods (e.g., a method of applying the coating liquid to a predetermined surface portion of a medical device using an application device such as a sprayer, bar coater, die coater, reverse coater, comma coater, gravure coater, spray coater, or doctor knife) can be used instead of the immersion method. In addition, when the structure of a medical device requires that both the outer and inner surfaces of a cylindrical device have a surface lubricating layer, the immersion method (dipping method) is preferably used because it allows both the outer and inner surfaces to be coated at the same time.

[0082] The amount of coating liquid applied is preferably such that the thickness (dry film thickness) of the resulting coating (surface lubricating layer) is 0.1 to 10 μm, more preferably 0.3 to 5 μm, and even more preferably 0.5 to 3 μm. If the amount of coating is such that the thickness of the coating (surface lubricating layer) is 0.1 μm or more, the durability of the resulting coating (surface lubricating layer) can be sufficiently achieved. Furthermore, if the amount of coating is such that the thickness of the coating (surface lubricating layer) is 10 μm or less, the surface of the coating (surface lubricating layer) becomes less sticky, making it easier to handle during production.

[0083] (III) Heat Treatment Step The manufacturing method of a medical device according to one embodiment includes the step of applying a coating liquid to the substrate layer of the medical device in the above-mentioned (II) coating step to form a coating film (coating layer), and then subjecting the substrate to heat treatment. In other words, a medical device according to one embodiment of the present invention can be produced by a manufacturing method including the step of applying a coating liquid to the substrate layer in the above-mentioned coating step to form a coating film (coating layer), and then subjecting the substrate to heat treatment. By subjecting the medical device to heat treatment, the surface lubricating layer has both excellent durability and lubricity, and the durability and surface lubricity of the medical device are also excellent.

[0084] The range of the heating temperature in the heat treatment step according to one embodiment is not particularly limited, but is preferably 50° C. to 200° C., and more preferably 90° C. to 180° C. By maintaining (heat treating) the temperature in such a range, a strong surface lubricating layer is formed.

[0085] The heating time in the heat treatment step according to one embodiment is not particularly limited, but is preferably 15 minutes to 20 hours, more preferably 30 minutes to 12 hours, and even more preferably 1 hour to 6 hours. By setting the heating time in this manner, the crosslinking reaction in the block copolymer is effectively promoted, and a stronger coating layer (surface lubricating layer) is formed, so that high surface lubricity can be maintained for a longer period of time.

[0086] In one embodiment of the manufacturing method, in the heat treatment step, it is preferable to perform a heat treatment in which the heating temperature is increased stepwise. By performing a heat treatment in which the heating temperature is increased stepwise, the durability and surface lubricity of the surface lubricating layer and the medical device become better.

[0087] Here, the reasons why the durability and surface lubricity of the surface lubricating layer and medical device obtained by this manufacturing method are excellent are unclear, but the following reasons are considered, for example. First, by performing a heat treatment in which the temperature is gradually increased from a relatively low heating temperature, the solvent remains in the coating film for a longer period of time compared to when the heat treatment is performed at a high temperature all at once, and the coating (surface lubricating layer) after heating and drying has high molecular mobility. This makes the coating (surface lubricating layer) more likely to absorb water when in contact with water, and the amount of water that the coating can contain is increased, which is thought to result in excellent surface lubricity. In addition, medical devices intended to be inserted into living bodies such as blood vessels generally experience increased frictional resistance when in contact with the inner surfaces of sheaths, catheters, etc. through which they pass. However, the medical device of the present invention has good surface lubricity, making it less susceptible to friction when in contact with the inner surfaces of sheaths, catheters, etc. This can prevent the abrasion and rubbing of the coating (surface lubricating layer), and can maintain the coating (surface lubricating layer) for a longer period of time, so that the durability of the coating (surface lubricating layer) and medical equipment is also thought to be excellent.In addition, in this manufacturing method, as described above, the solvent remains in the coating film for a longer period of time during the heat treatment, so that the coating (surface lubricating layer) after drying is less damaged by heating, which is also thought to be one of the reasons for improving durability.In addition, the above mechanism is speculation, and does not limit the technical scope of the present invention.

[0088] Here, the heat treatment "increasing the temperature stepwise" is preferably a treatment including a step of maintaining a predetermined heating temperature for a certain period of time and a step of increasing the temperature to the predetermined heating temperature without stopping the temperature increase. In addition, in the heat treatment "increasing the temperature stepwise" in one embodiment, it is preferable to repeat the step of maintaining a predetermined heating temperature for a certain period of time and the step of increasing the temperature to the predetermined heating temperature without stopping the temperature increase two or more times. Therefore, in a method for manufacturing a medical device according to one embodiment, a medical device is provided which includes a base layer and a surface lubricating layer carried on at least a part of the base layer, and the spin-spin relaxation time (T ２It is preferable to have a step of performing a heat treatment in which the heating temperature is increased stepwise so as to obtain a medical device in which the value of the component with high molecular mobility in the

[0089] (IV) Other Steps In one embodiment of the production method, a drying step may be included before the heat treatment step. In the drying step, excess solvent is removed, allowing the subsequent heat treatment step to proceed more efficiently. The temperature of the drying step is not particularly limited, but is preferably 10°C or higher and lower than 50°C, and more preferably 20 to 30°C. The drying time is also not particularly limited, but is preferably 15 minutes to 20 hours, more preferably 30 minutes to 12 hours. The pressure conditions during drying are also not particularly limited, and drying can be performed under normal pressure (atmospheric pressure), or under increased or reduced pressure.

[0090] The heating step and the drying step can be carried out by using, for example, an oven, a vacuum dryer, etc. When the drying step is carried out by natural drying, no special drying means (device) is required.

[0091] <Uses of Medical Device> Examples of the medical device according to the present invention include devices that are used in contact with body fluids, blood, etc., and the devices have a surface that is lubricious in body fluids, aqueous liquids such as physiological saline, and are capable of improving operability and reducing damage to tissue mucosa. Examples of the medical device according to the present invention are not particularly limited, but suitable examples include catheters, guide wires, and indwelling needles that are used in blood vessels.

[0092] Although the embodiments of the present invention have been described in detail above, it is clear that these are for illustrative and exemplary purposes only and are not limiting, and the scope of the present invention should be interpreted by the appended claims.

[0093] The effects of the present invention will be explained using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. In the following examples, unless otherwise specified, operations were performed at room temperature (25°C). Furthermore, unless otherwise specified, "%" and "parts" mean "% by mass" and "parts by mass", respectively.

[0094] Synthesis Example 1: Synthesis of Block Copolymer (1) Block copolymer (1) was produced by the following reaction.

[0095]

[0096] 29.7 g of triethylene glycol was added dropwise to 72.3 g of adipic acid dichloride at 50°C, and then the hydrochloric acid was removed under reduced pressure at 50°C for 3 hours to obtain an oligoester. Next, 4.5 g of methyl ethyl ketone was added to 22.5 g of the obtained oligoester, and this was added dropwise to a solution consisting of 5 g of sodium hydroxide, 6.93 g of 31% hydrogen peroxide, 0.44 g of dioctyl phosphate as a surfactant, and 120 g of water, and the reaction was carried out at -5°C for 20 minutes. The obtained product was repeatedly washed with water and methanol and then dried to obtain a polyperoxide (PPO) having multiple peroxide groups in the molecule.

[0097] Next, 0.5 g of this PPO, 9.5 g of glycidyl methacrylate (GMA), and 30 g of benzene as a solvent were polymerized at 80°C for 2 hours with stirring under reduced pressure. The reaction product obtained after the polymerization was reprecipitated with diethyl ether to obtain polyglycidyl methacrylate (PPO-GMA) having multiple peroxide groups in the molecule.

[0098] Subsequently, 1.35 g of the obtained PPO-GMA (corresponding to 9.5 mmol of GMA) was added to 11.2 g (113 mmol) of N,N-dimethylacrylamide (DMAA) and 90 g of dimethyl sulfoxide as a solvent, and the mixture was reacted at 80°C for 18 hours. The reaction product obtained after the reaction was reprecipitated with hexane and recovered to obtain a block copolymer (1) (structural unit (A):structural unit (B) = GMA:DMAA = 1:12 (molar ratio)) having an epoxy group in the molecule and exhibiting lubricity when wet. The block copolymer (1) thus obtained was１ Analysis by H-NMR and ATR-IR confirmed the presence of epoxy groups in the molecule. Furthermore, the weight average molecular weight (Mw) of block copolymer (1) measured by gel permeation chromatography (GPC, polystyrene equivalent) was approximately 1.5 million.

[0099] [Production of Sample of Example 1] A coating solution was prepared by dissolving the block copolymer (1) obtained in Synthesis Example 1 above in N,N-dimethylformamide (DMF) so that the final concentration in the solution was 4.5% by mass. 10 g of the coating solution was placed in a fluorine-made Petri dish and dried at room temperature (25°C) for 1 hour to form a cast film. The cast film was then placed in an oven, and the temperature inside the oven was increased from room temperature to 100°C within 1 hour without stopping the temperature increase. After reaching 100°C, the temperature was increased stepwise to 130°C while storing for 1.5 hours for heat treatment, and a sample of Example 1 was obtained.

[0100] [Production of Sample of Comparative Example 1] A sample of Comparative Example 1 was produced in the same manner as in Example 1, except that the cast film was placed in an oven, the temperature in the oven was increased from room temperature to 130°C within 1 hour without stopping the temperature increase, and the film was stored at 130°C for 1 hour.

[0101] [Production of Sample of Reference Example 1] The block copolymer (1) obtained in Synthesis Example 1 above was dissolved in acetone so that the final concentration in the liquid was 4.5% by mass to prepare a coating liquid. 10 g of the coating liquid was placed in a fluorine petri dish and dried at room temperature (25°C) for 1 hour to obtain a sample of Reference Example 1. In the production of the sample of Reference Example 1, the film was not subjected to heat drying.

[0102] [Measurement of Spin-Spin Relaxation Time] For each of the samples prepared above in Example 1, Comparative Example 1, and Reference Example 1, pulse NMR analysis was carried out, and the spin-spin relaxation time (T ２ The measurement conditions for the CPMG method of pulsed NMR are described below. Apparatus: minispecmq20 (pulsed NMR, manufactured by Bruker) Observation nuclei: １H (resonance frequency: 20 MHz) Measurement temperature: 60°C Repetition time: 1 s Number of accumulations: 512 times.

[0103] From the measurement results obtained above, the following relaxation time T ２ The spin-spin relaxation time (T ２ The values ​​of the components with high molecular mobility, the values ​​of the components with low molecular mobility, and the component ratios (proportions) of the components with high molecular mobility and the components with low molecular mobility were calculated. The results are shown in Table 1.

[0104]

[0105]

[0106] As shown in the above results, the value on the side of high molecular mobility was 20 ms for the sample of Example 1, whereas it was 16 ms for the sample of Comparative Example 1. This indicates that the sample of Example 1 has higher molecular mobility than Comparative Example 1.

[0107] Here, the sample of Reference Example 1 did not undergo a heat treatment process in the production process, so crosslinking of the block copolymer did not progress, and therefore the sample had very high molecular mobility, but on the other hand, it had almost no durability. In the sample of Reference Example 1, which is expected to have very high molecular mobility, the value of the component with high molecular mobility was 18 ms, while in the sample of Example 1, the value of the component with high molecular mobility was 20 ms. This indicates that the sample of Example 1 has higher molecular mobility than the sample of Reference Example 1.

[0108] The above results show that the sample of Example 1 has excellent durability because it has undergone a heat treatment step in the production process and crosslinking of the block copolymer has progressed, and therefore it also has very good molecular mobility.

[0109] [Production of Samples in Example 2] In Example 2, the following sample materials (hereinafter referred to as catheter materials) were used. FineCross (registered trademark) MG catheter for penetrating coronary artery stenosis (manufactured by Terumo Corporation, uncoated) - Inner diameter: tip 0.45 mm, shaft 0.55 mm - Outer diameter: tip 0.60 mm, shaft 0.87 mm - Length: 130 cm A coating solution was prepared by dissolving the block copolymer (1) obtained in Synthesis Example 1 above in N,N-dimethylformamide (DMF) to a final concentration of 4.5% by mass in the solution. The distal end 70 cm of the substrate of the catheter material was immersed in the coating solution, and after removal from the coating solution, the substrate was dried at room temperature (25°C) for 1 hour, forming a coating film on the entire outer surface of the substrate from the distal end 70 cm. The catheter material with the coating film formed thereon was then placed in an oven, and the temperature in the oven was increased from room temperature to 100°C within 1 hour without stopping the temperature increase. After reaching 100°C, the sample was heated stepwise to 130°C and stored for 1.5 hours. This resulted in the preparation of a sample of Example 1 having a coating layer (surface lubrication layer) containing a cross-linked copolymer derived from a block copolymer. The coating layer covered the outer surface of the catheter material from the tip of the catheter to a length of 70 cm in the longitudinal direction, and the coating layer had a thickness of 1 μm.

[0110] [Production of Sample of Comparative Example 2] A sample of Comparative Example 2 having a coating layer (surface lubrication layer) was produced in the same manner as in Example 2, except that the catheter material on which the coating film was formed was placed in an oven, and the temperature inside the oven was raised from room temperature to 130°C within 1 hour without stopping the temperature rise, and then the sample was stored at 130°C for 1 hour for heat treatment.

[0111] [Evaluation of Sliding Resistance] For the samples of Example 2 and Comparative Example 2, a sliding resistance evaluation test was conducted using a precision universal testing machine (AG-X, manufactured by Shimadzu Corporation) according to the following procedure. The results are shown in Table 2. 1. The precision universal testing machine conditions were set as follows. Note that the number of samples for both Example 2 and Comparative Example 2 was 100 or more (n≧100). Test speed: 500 mm / min Stroke: 40 mm Number of repetitions: 30 2. The sample was inserted 250 mm into a water-filled serpentine route (R30 → R15 → R10 × 4 → R7.5 × 3), and the protruding portion (rear end) was gripped with the chuck of the precision universal testing machine. A polyamide elastomer tube with an inner diameter of 1.05 mm and an outer diameter of 1.35 mm was used for the serpentine route. 3. The test was started, and the sliding resistance values ​​for each of the 1st to 30th runs were calculated and recorded. The sliding resistance value for each test was calculated as follows: First, the maximum test force (gf) for each test was measured for each sample using a precision universal testing machine. Next, the average value of the maximum test forces measured for each test was calculated, and this average value was used as the sliding resistance value for each test.

[0112] The "sliding resistance value at the 30th time" and the "increase (gf)" obtained by subtracting the "sliding resistance value at the 5th time" from the "sliding resistance value at the 30th time" obtained as a result of the above measurement were used to evaluate the sliding resistance.

[0113]

[0114] From the above results, the sample according to Example 2 exhibited lower values ​​for both the sliding resistance value and the increase amount at the 30th time than the sample according to Comparative Example 2. These results show that the sample according to Example 2 has superior surface lubricity compared to the sample according to Comparative Example 2, and furthermore, the surface lubricity is more sustained, i.e., it is also superior in durability.

[0115] The above results demonstrate that the medical device according to the present invention has both excellent surface lubricity and excellent durability.

[0116] This application is based on Japanese Patent Application No. 2024-055706, filed on March 29, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0117] 10 Medical device, 1 Base material layer, 1a Base material layer core portion, 1b Base material surface layer, 2 Lubricating layer.

Claims

1. A medical device comprising a base layer and a surface lubricating layer carried on at least a portion of the base layer, wherein the spin-spin relaxation time (T ２ A medical device in which the value of the component with high molecular mobility in the 2. The spin-spin relaxation time (T ２ 2. The medical device according to claim 1, wherein the value of the component with high molecular mobility in the 3. The spin-spin relaxation time (T ２ 3. The medical device according to claim 1, wherein the proportion of the component with high molecular mobility to the total amount of the component with high molecular mobility and the component with low molecular mobility in the medical device is 80% or more.

4. The medical device according to claim 1 or 2, wherein the sliding resistance value at the 30th time in a sliding resistance evaluation test is 12 gf or less.

5. The medical device according to claim 1 or 2, wherein the increase (gf) obtained by subtracting the sliding resistance value at the 5th time from the sliding resistance value at the 30th time in a sliding resistance evaluation test is 1.2 gf or less.

6. The medical device according to claim 1 or 2, which is a catheter, a guidewire, or an indwelling needle.

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