Medical device and method for determining non-uniform distribution

Abstract

The present application provides a medical tool having excellent sliding properties and durability. The medical tool is a medical tool having a base material layer and a surface lubricating layer carried on at least a part of the surface of the base material layer, wherein the surface lubricating layer contains 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 hydrophobic resin, and the standard deviation of the R value of the surface lubricating layer after staining with a Congo red solution is 10 or less.

Description

Technical Field

[0001] This invention relates to medical devices and methods for measuring non-uniform distribution. Background Technology

[0002] For medical devices inserted into the body, such as catheters, guidewires, and indwelling needles, excellent lubricity is required to reduce damage to blood vessels and other tissues and improve operator operability. Therefore, a method of coating a substrate layer with a lubricating hydrophilic polymer has been developed and put into practical use. However, in such medical devices, the hydrophilic polymer can dissolve and peel off from the substrate layer, causing problems in maintaining operability. Therefore, coatings formed from hydrophilic polymers require not only excellent lubricity but also durability against abrasion, scratching, and other loads.

[0003] From this perspective, Japanese Patent Application Publication No. 8-33704 discloses a medical device in which a polymer solution is prepared by dissolving a water-soluble or water-swellable polymer in a solvent that swells a substrate of the medical device. The substrate of the medical device is then immersed in the polymer solution to swell, and the polymer is further cross-linked or polymerized on the surface of the substrate, thereby forming a surface lubricating layer on the substrate surface. According to the technology disclosed in Japanese Patent Application Publication No. 8-33704, a surface lubricating layer exhibiting relatively good lubricity can be fixed to the substrate. Summary of the Invention

[0004] Japanese Patent Application Publication No. 8-33704 discloses that, as a water-soluble or water-swellable polymer, a block copolymer comprising a hydrophilic portion exhibiting lubricity and an epoxy group portion is preferred. Furthermore, when using such a block copolymer, the epoxy groups of the block copolymer can be crosslinked by heating, forming a surface lubricating layer that is less prone to peeling. However, good lubricity (slipability) and excellent durability (especially slip durability) are mutually restrictive, requiring a technology that simultaneously achieves both.

[0005] In recent years, medical devices have seen significant miniaturization and reduction in diameter. Within living organisms, medical procedures that allow devices to pass through more flexible and narrower lumens such as blood vessels to reach lesion sites are becoming increasingly common. Furthermore, with the increasing complexity of medical procedures, prolonged manipulation of medical devices is sometimes required. Therefore, to maintain good operability of medical devices even at complex lesion sites, there is a need for technologies that further improve the durability (especially sliding durability) of the device surface (surface lubrication layer) compared to existing technologies. More specifically, there is a need for devices that can maintain high lubricity (sliding performance) and excellent durability (especially sliding durability) even under repeated sliding of the device surface (surface lubrication layer).

[0006] Therefore, there is a need for technologies that can improve the durability of medical devices (especially sliding durability) and support complex and sophisticated medical procedures.

[0007] The present invention was made in view of the above circumstances, and its object is to provide a medical device having a surface lubricating layer that exhibits excellent durability and lubricity.

[0008] The inventors of this application conducted in-depth research to solve the aforementioned problems. As a result, they discovered that, in medical devices, the above-mentioned objective can be achieved by setting the deviation of the thickness of a surface lubricating layer containing specified components to a certain value or less, thus completing this invention.

[0009] The above-mentioned objectives can be achieved by the present invention having the following structure, which includes the following modes and forms.

[0010] One aspect of the present invention is as follows: 1. A medical device having a substrate layer and a surface lubricating layer supported on at least a portion of the substrate layer, wherein, The aforementioned surface lubricating layer comprises a block copolymer having structural units (A) derived from reactive monomers with epoxy groups and structural units (B) derived from hydrophilic monomers, and a hydrophobic resin. The standard deviation of the R value of the aforementioned surface lubricating layer after staining with Congo red solution is less than 10.

[0011] 2. The medical device as described in 1. above, wherein, preferably, the ratio (molar ratio) of the aforementioned structural unit (A) derived from the reactive monomer having an epoxy group to the aforementioned structural unit (B) derived from the hydrophilic monomer in the aforementioned block copolymer is 1:20 to 1:50.

[0012] 3. The medical device as described in 1. or 2. above, wherein, preferably, the content (mass%) of the aforementioned hydrophobic resin in the aforementioned surface lubricating layer is less than the content (mass%) of the aforementioned block copolymer.

[0013] 4. The medical device as described in any one of 1. to 3. above, wherein, preferably, the aforementioned hydrophobic resin is polyvinyl chloride (PVC) resin.

[0014] 5. The medical device as described in any one of 1. to 4. above, wherein, preferably, the aforementioned reactive monomer having an epoxy group comprises at least one selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexyl methyl acrylate, 3,4-epoxycyclohexyl methyl methacrylate, β-methyl glycidyl methacrylate, and allyl glycidyl ether.

[0015] 6. The medical device as described in any one of 1 to 5 above, wherein, preferably, the aforementioned hydrophilic monomer comprises at least one selected from the group consisting of N,N-dimethylacrylamide, acrylamide, 2-hydroxyethyl methacrylate and N-vinylpyrrolidone.

[0016] 7. The medical device as described in any one of 1. to 6. above, wherein, preferably, the sliding resistance value of the aforementioned surface lubricating layer during 10 sliding cycles in the sliding resistance test is 8.5 gf or less.

[0017] One aspect of the present invention is as follows: 8. A method for determining non-uniform distribution, wherein the non-uniform distribution of a surface lubricating layer in a medical device having a surface lubricating layer is evaluated by using the standard deviation of the R value of the aforementioned surface lubricating layer after staining with Congo red solution. Attached Figure Description

[0018] [ Figure 1 [A partial cross-sectional view illustrating the layered structure of the surface of a representative embodiment of the medical device (catheter) according to the present invention.]

[0019] [ Figure 2 As Figure 1 A partial cross-sectional view of a laminated structure having a surface with uneven thickness is schematically shown as a comparative example of the embodiments.

[0020] [ Figure 3 This is a graph illustrating how the mean and standard deviation of the R-value are calculated.

[0021] [ Figure 4 This is a schematic diagram of the sliding and durability testing apparatus (friction tester) used in the reference example. Detailed Implementation

[0022] One aspect of the present invention relates to a medical device having a substrate layer and a surface lubricating layer supported on at least a portion of the substrate layer, wherein the surface lubricating layer comprises a block copolymer having structural units (A) derived from a reactive monomer having an epoxy group and structural units (B) derived from a hydrophilic monomer, and a hydrophobic resin, and the standard deviation of the R value of the aforementioned surface lubricating layer after staining with Congo red solution is less than 10.

[0023] The embodiments of the present invention will be described below. It should be noted 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 combined arbitrarily to form other embodiments. For ease of explanation, the dimensions of the accompanying drawings are exaggerated and sometimes differ from the actual proportions. Additionally, please refer to the accompanying drawings... Figure 1 As embodiments of the present invention are described, the same reference numerals are used for the same elements in the description of the drawings, and repeated descriptions are omitted.

[0024] In this specification, the structural unit (A) derived from the reactive monomer having an epoxy group will be referred to as "the structural unit (A) of this invention" or "structural unit (A)". Similarly, the structural unit (B) derived from the hydrophilic monomer will be referred to as "the structural unit (B) of this invention" or "structural unit (B)". Furthermore, the block copolymer having structural units (A) and (B) will be referred to as "the block copolymer of this invention" or "block copolymer".

[0025] In this specification, when a structural unit is specified as "derived" from a specific monomer, it means that the structural unit is a divalent structural unit generated by cleaving one bond of the polymerizable unsaturated double bond in the corresponding monomer.

[0026] In this specification, the term "(meth)acrylic" includes both acrylic acid and methacrylic acid. Therefore, for example, the term "(meth)acrylic" includes both acrylic acid and methacrylic acid. Similarly, the term "(meth)acryloyl" includes both acryloyl and methacryloyl. Therefore, for example, the term "(meth)acryloyl" includes both acryloyl and methacryloyl. Furthermore, similarly, the term "(meth)acrylate" includes both acrylate and methacrylate. For example, the term "(meth)acrylate alkoxyalkyl ester" includes both alkoxyalkyl acrylate and alkoxyalkyl methacrylate.

[0027] Furthermore, throughout this specification, unless otherwise specified, the singular form should be understood to also include the concept of its plural form. Therefore, unless otherwise specified, articles in the singular form (e.g., "a," "an," "the," etc. in the English context) should be understood to also include the concept of their plural forms. Furthermore, unless otherwise specified, the terminology used in this specification should be understood to be used in the meaning commonly understood in the art. Therefore, unless otherwise defined, all specialized and technical terms used in this specification have the same meaning as commonly understood by those skilled in the art to which this invention pertains. In case of conflict, this specification (including definitions) takes precedence. The invention is not limited to the embodiments described below and various modifications can be made within the scope of the claims. Additionally, in this specification, "X~Y" indicating a range includes both X and Y, meaning "more than X and less than Y." Furthermore, "X and / or Y" includes each of X and Y and all combinations thereof; specifically, it means at least one of X and Y, including X alone, Y alone, and combinations of X and Y. Furthermore, unless otherwise specified, concentration "%" represents mass concentration "mass%".

[0028] Unless otherwise specified, the operation and physical properties are measured at room temperature (20-25°C) and relative humidity (40-50%RH).

[0029] [Medical Equipment] The following is for reference Figure 1 and Figure 2 Preferred embodiments of the medical device involved in this invention will be described.

[0030] Figure 1 This is a partial cross-sectional view of the surface of a catheter, showing a layered structure without uneven thickness, as a representative embodiment of the medical device (also referred to as "medical device" in this specification) involved in the present invention. Figure 2 A partial cross-sectional view of a laminated structure with uneven thickness is shown schematically as a comparative example of this embodiment. It should be noted that... Figure 1 and Figure 2 The reference numerals in the figures represent the following: Reference numeral 1 represents the substrate layer; reference numeral 2 represents the surface lubrication layer; reference numeral 3 represents the inner lumen; and reference numeral 10 represents the conduit.

[0031] like Figure 1 As shown, the conduit 10 of this embodiment includes a substrate layer 1 and a surface lubricating layer 2. The aforementioned surface lubricating layer 2 is disposed on at least a portion of the substrate layer 1 (an example is shown in the figure of being disposed on the entire surface of the substrate layer 1) and comprises a block copolymer and a hydrophobic resin. The conduit 10 has an inner lumen 3 extending from the front end to the base end.

[0032] (Substrate layer (substrate)) The substrate layer used in this embodiment can be made of any material, and there are no particular limitations on the material. Specifically, examples of materials constituting the substrate layer include polymer materials (resin materials) and materials obtained by embedding metal wires in polymer materials.

[0033] Furthermore, there are no particular limitations on the polymer materials (resin materials or elastomer materials) used in the aforementioned substrate layer; polymer materials commonly used in medical devices such as catheters, guides, guidewires, and indwelling needles can be used. Specifically, examples include polyamide resins, polyethylene resins, polypropylene resins, and other polyolefin resins; modified polyolefin resins; cyclic polyolefin resins; epoxy resins; polyurethane resins; diallyl phthalate resins (allyl resins); polycarbonate resins; fluororesins; amino resins (urea resins, melamine resins, benzoguanamine resins); polyethylene terephthalate resins; polybutylene terephthalate resins, and other polyester resins; styrene resins; acrylic resins; polyacetal resins; vinyl acetate resins; phenolic resins; vinyl chloride resins; silicone resins; polyether resins; and polyimide resins.

[0034] In addition, thermoplastic elastomers such as polyurethane elastomers, polyester elastomers, and polyamide elastomers (nylon elastomers) can also be used as materials for the substrate layer.

[0035] These polymer materials can be used alone, as a mixture of two or more, or as copolymers of two or more monomers constituting any of the aforementioned resins or elastomers. Among these, polyethylene resin, polyurethane resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyester elastomer, polyamide resin, and polyamide elastomer are preferred polymer materials; more preferably, polyamide resin and polyamide elastomer are preferred; and particularly preferred are block copolymers of polybutylene terephthalate and polytetramethylene glycol, and block copolymers of nylon 12 and polytetramethylene glycol. The carboxyl and amino groups contained in the block copolymers of polybutylene terephthalate and polytetramethylene glycol, polyamide resins, and polyamide elastomers, as terminal groups, can undergo crosslinking reactions with the epoxy groups in the block copolymers. Of the aforementioned polymer materials, the most suitable polymer material can be selected for use as a substrate layer in catheters, guidewires, indwelling needles, etc., for applications such as catheters.

[0036] In addition, there are no particular restrictions on the shape of the above-mentioned substrate layer. It can be appropriately selected as sheet, wire (filament), rod, tubular, etc., depending on the application.

[0037] (Surface lubrication layer) The surface lubricating layer 2 is supported on at least a portion of the substrate layer 1. The reason for supporting the surface lubricating layer 2 on at least a portion of the surface of the substrate layer 1 is that in medical devices such as catheters, guidewires, and indwelling needles intended for use, it is not necessary for the entire surface (the entire surface) of these medical devices to be lubricated (sliding) when wet. The surface lubricating layer 2 is only supported on the surface portion that is required to be lubricated (sliding) when wet, such as the tip (sometimes a part, sometimes the whole).

[0038] One aspect of the present invention relates to a surface lubricating layer comprising a block copolymer having structural units (A) derived from a reactive monomer having an epoxy group and structural units (B) derived from a hydrophilic monomer, and a hydrophobic resin.

[0039] Block copolymers In this invention, a block copolymer forms a surface lubricating layer supported on at least a portion of the substrate layer. That is, in the medical device obtained by the method of this invention, the surface lubricating layer comprises a block copolymer.

[0040] The block copolymers involved in this invention have structural units (A) derived from reactive monomers having epoxy groups and structural units (B) derived from hydrophilic monomers.

[0041] The reactive monomers constituting the block copolymers have epoxy groups as reactive functional groups. By introducing such structural units (A) derived from reactive monomers into the block copolymers, the epoxy groups undergo ring-opening, leading to cross-linking (bonding) between the block copolymers and improving the film strength of the surface lubricating layer. Furthermore, when the substrate layer is a resin material, the ring-opening epoxy groups also facilitate cross-linking (bonding) between the block copolymers and the substrate layer.

[0042] The reactive monomer constituting the block copolymer can be any compound that has an epoxy group, and there are no particular limitations; known compounds can be used. From the perspective of easily controlling the crosslinking or polymerization of the block copolymer, 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-epoxycyclohexyl acrylate, 3,4-epoxycyclohexyl methacrylate, β-methyl glycidyl methacrylate, and allyl glycidyl ether. Glycidyl acrylate is more preferred, and particularly preferred, considering its ability to further promote the crosslinking reaction and ease of manufacture.

[0043] The aforementioned reactive monomers can be used alone or in combination with two or more. That is, the reactive sites derived from the reactive monomers can be homopolymers composed of a single reactive monomer or copolymers composed of two or more of the aforementioned reactive monomers. It should be noted that when using two or more, the reactive sites can be block copolymers or random copolymers.

[0044] That is, in a preferred embodiment of the present invention, the epoxy-containing reactive monomer comprises at least one selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexyl acrylate, 3,4-epoxycyclohexyl methacrylate, β-methyl glycidyl methacrylate, and allyl glycidyl ether. In a more preferred embodiment of the present invention, the epoxy-containing reactive monomer is at least one of glycidyl acrylate and glycidyl methacrylate. In a particularly preferred embodiment of the present invention, the epoxy-containing reactive monomer is glycidyl methacrylate. In a preferred embodiment of the present invention, the epoxy-containing reactive monomer is a (meth)acrylate having an epoxy alkyl group. The alkyl group preferably has 1 to 3 carbon atoms. In a preferred embodiment of the present invention, the epoxy-containing reactive monomer is a (meth)acrylate having an epoxy group.

[0045] The hydrophilic monomers that make up the block copolymer exhibit swelling properties when in contact with aqueous solvents such as bodily fluids, thus imparting lubricity (sliding properties) to medical devices. Therefore, by introducing such structural units (B) derived from hydrophilic monomers into the block copolymer, the lubricity (sliding properties) of the medical device can be improved, thereby reducing friction when the medical device comes into contact with the walls of lumens such as blood vessels.

[0046] There are no particular limitations on the hydrophilic monomers constituting the block copolymers, provided they possess the aforementioned properties; known compounds can be used. Examples include acrylamide or its derivatives, vinylpyrrolidone, acrylic acid or methacrylic acid and their derivatives, polyethylene glycol acrylates and their derivatives, monomers with sugars or phospholipids in their side chains, and water-soluble monomers such as maleic anhydride. More specifically, examples include acrylic acid, methacrylic acid, N-methacrylamide, N,N-dimethylacrylamide (DMAA), acrylamide, acryloylmorpholine, N,N-dimethylaminoethyl acrylate, N-vinylpyrrolidone, 2-methacryloyloxyethyl phosphocholine, 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, and 1,4-cyclohexanediethanol mono(meth)acrylate. Ester, 1-chloro-2-hydroxypropyl methacrylate, 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 methacrylate, 4-hydroxycyclohexyl methacrylate, 2-hydroxy-3-phenyloxy methacrylate, cyclohexanediol mono(meth)acrylate, poly(ethylene glycol) methyl ether acrylate and poly(ethylene glycol) methyl ether methacrylate, etc. From the viewpoint of imparting excellent lubricity (slippery properties), ease of synthesis, and operability, the hydrophilic monomer preferably comprises at least one selected from the group consisting of N,N-dimethylacrylamide, acrylamide, 2-hydroxyethyl methacrylate, and N-vinylpyrrolidone, more preferably at least one selected from the group consisting of N,N-dimethylacrylamide, acrylamide, and 2-hydroxyethyl methacrylate. Of these, from the viewpoint of excellent lubricity (slippery properties), N,N-dimethylacrylamide is particularly preferred. In a preferred embodiment of the present invention, the hydrophilic monomer is a dialkylacrylamide. The number of carbon atoms in each dialkyl group is preferably 1 to 3.

[0047] The aforementioned hydrophilic monomers can be used alone or in combination with two or more. That is, the hydrophilic portion derived from the hydrophilic monomer can be a homopolymer composed of a single hydrophilic monomer, or a copolymer composed of two or more of the aforementioned hydrophilic monomers. It should be noted that when using two or more, the hydrophilic portion can be a block copolymer or a random copolymer, but a block copolymer is preferred.

[0048] That is, in a preferred embodiment of the present invention, the hydrophilic monomer comprises at least one selected from the group consisting of N,N-dimethylacrylamide, acrylamide, 2-hydroxyethyl methacrylate, and N-vinylpyrrolidone. 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. In a particularly preferred embodiment of the present invention, the hydrophilic monomer is N,N-dimethylacrylamide.

[0049] The block copolymer has the aforementioned structural unit (A) and structural unit (B). Here, the ratio of structural unit (A) to structural unit (B) is not particularly limited as long as the aforementioned effects are achieved. Considering good lubricity (slipability), lubrication maintenance (slip maintenance), coating strength, and adhesion to the substrate layer, the ratio of structural unit (A) to structural unit (B) (molar ratio of structural unit (A): structural unit (B)) can be 1:2 to 1:100, 1:2 to 1:50, 1:5 to 1:50, 1:10 to 1:50, 1:20 to 1:50, 1:2 to 1:45, 1:5 to 1:45, 1:10 to 1:45, or 1:20 to 1:45. Within such a range, the surface lubricating layer can fully utilize its slipability through structural unit (B), and can also achieve sufficient coating strength, adhesion to the substrate layer (in the case of resin materials), and durability through structural unit (A). It should be noted that the molar ratio of structural unit (A):structural unit (B) can be controlled by adjusting the charge ratio (molar ratio) of each monomer during the manufacturing stage of the block copolymer. Therefore, the charge ratio (molar ratio) of the reactive monomer with epoxy groups to the hydrophilic monomer during the manufacturing stage of the block copolymer can be 1:2–1:100, 1:2–1:50, 1:5–1:50, 1:10–1:50, 1:20–1:50, 1:2–1:45, 1:5–1:45, 1:10–1:45, or 1:20–1:45. It should also be noted that the molar ratio of structural unit (A):structural unit (B) can be determined, for example, by NMR analysis of the copolymer. 1 H-NMR measurement, 13 Confirmation can be made through methods such as C-NMR measurements.

[0050] The block copolymers involved in this invention must contain structural units (A) and (B), and may also contain other structural units. Examples of other structural units in block copolymers include adipic acid, glutaric acid, triethylene glycol, and tripropylene glycol. The monomers constituting the other structural units may be used individually 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. It should be noted that when using two or more monomers constituting the aforementioned other structural units, the segments formed by these monomers may be in the form of block copolymers, random copolymers, or alternating copolymers.

[0051] When the block copolymer of the present invention has other structural units, the content of the other structural units is preferably greater than 0 mol% and less than 5 mol% relative to the total number of structural units constituting the block copolymer. That is, in the block copolymer of the present invention, when the total number of all structural units constituting the block copolymer is set to 100 mol%, the total content of structural unit (A) and structural unit (B) is preferably 95 mol% or more (upper limit: less than 100 mol%). More preferably, the block copolymer of the present invention is substantially composed of structural unit (A) and structural unit (B) (here, in this specification, "substantially composed" means that the content of other structural units is greater than 0 mol% and less than 5 mol%). In this form, the block copolymer of the present invention can achieve a good balance between the durability brought by structural unit (A) and the lubricity (slippage) brought by structural unit (B). Preferably, the block copolymer of the present invention does not contain the above-mentioned other structural units (the content of other structural units = 0 mol%).

[0052] It should be noted that the composition of each structural unit (structural units (A) and (B), and other structural units) can be determined using known methods. For example, by analyzing the block copolymer solution... 1 By measuring the integral ratio of each signal intensity in the H-NMR spectrum, the composition (molar ratio) of the structural units can be determined.

[0053] In one embodiment of the present invention, the block copolymer involved in the present invention is substantially 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-epoxycyclohexyl acrylate, 3,4-epoxycyclohexyl methacrylate, β-methyl glycidyl 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 above-described structural units (A) and structural units (B).

[0054] In one embodiment of the present invention, the block copolymer involved in the present invention is substantially composed of structural units (A) derived from at least one reactive monomer selected from glycidyl acrylate and glycidyl methacrylate, and structural units (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 above-mentioned structural units (A) and structural units (B).

[0055] In one embodiment of the present invention, the block copolymer involved in the present invention is substantially composed of structural units (A) derived from glycidyl methacrylate (a reactive monomer with an epoxy group) and structural units (B) derived from N,N-dimethylacrylamide (a hydrophilic monomer), or is composed only of the above-described structural units (A) and structural units (B).

[0056] From a solubility perspective, the weight-average molecular weight of the block copolymer is preferably 10,000 to 10,000,000. From the perspective of ease of preparation of the coating solution, the weight-average molecular weight of the block copolymer is more preferably 100,000 to 5,000,000. In this specification, "weight-average molecular weight" is the value determined by gel permeation chromatography (GPC) using polystyrene as a standard.

[0057] There are no particular limitations on the manufacturing method of block copolymers. For example, conventionally known polymerization methods such as living radical polymerization, polymerization using macromolecular initiators, and polycondensation (e.g., the polymerization method described in Japanese Patent Application Publication No. 2014 / 162872) can be used. Among these, living radical polymerization or polymerization using macromolecular initiators is preferred from the perspective of easy control over the molecular weight and molecular weight distribution of structural units (sites) derived from reactive monomers and structural units (sites) derived from hydrophilic monomers. As for living radical polymerization, there are no particular limitations. For example, the methods described in Japanese Patent Application Publication Nos. 11-263819, 2002-145971, and 2006-316169, as well as atom transfer radical polymerization (ATRP), can be used in the same way or with appropriate modifications. In addition, in polymerization methods using macromolecular initiators, for example, after preparing a macromolecular initiator containing reactive sites with reactive functional groups and free radical polymerizable groups such as peroxide groups, the macromolecular initiator is polymerized with monomers used to form hydrophilic sites, thereby producing block copolymers having hydrophilic and reactive sites.

[0058] In addition, the polymerized block copolymer is preferably purified using conventional purification methods such as reprecipitation, dialysis, ultrafiltration, and extraction.

[0059] <Hydrophobic resin> The surface lubricating layer of the medical device of the present invention comprises a hydrophobic resin. The hydrophobic resin induces ring-opening of the epoxy groups present in the block copolymer. If the epoxy groups are ring-opened, cross-linking (bonding) occurs between the block copolymers. In addition, the medical device can maintain its shape well after sliding. From the viewpoint of further obtaining the above-mentioned effects, the hydrophobic resin is preferably selected from one or more of polyvinyl chloride (PVC) resin or urethane resin, more preferably polyvinyl chloride (PVC) resin. Here, vinyl chloride resin refers to poly(1-chloroethylene) as defined in the IUPAC nomenclature. As long as it mainly contains poly(1-chloroethylene), it can also be a commercially available soft vinyl chloride resin or hard vinyl chloride resin. In order to maintain constant performance, reagent-grade vinyl chloride resin (PVC) with a poly(1-chloroethylene) content of 100% or less is preferred, and vinyl chloride resin that substantially does not contain plasticizers or additives is particularly preferred. Here, the phrase "vinyl chloride resin substantially free of plasticizers and additives" means that, except for cases where vinyl chloride resin contains absolutely no plasticizers and additives (below the detection limit), when vinyl chloride resin does contain plasticizers and additives, their total amount is less than 10 ppm by mass. It should be noted that vinyl chloride resin (PVC) only needs to contain structural units derived from vinyl chloride (1-chloroethylene). That is, it can be a homopolymer composed solely of it, or a copolymer containing structural units derived from monomers other than vinyl chloride (1-chloroethylene). However, considering slip properties and durability, homopolymers are preferred. Therefore, according to one embodiment of the present invention, the vinyl chloride resin is a homopolymer composed of structural units derived from vinyl chloride (1-chloroethylene) and substantially free of plasticizers and additives.

[0060] It should be noted that, in this specification, the hydrophobic resin is preferably insoluble in water. "Insoluble in water" means a substance that is insoluble (or sparingly soluble) in water at room temperature (23°C) and normal pressure (1 atmosphere). For example, it means a substance whose solubility in 100 ml of water at room temperature and normal pressure is less than 1 g, but it is not limited to this.

[0061] In one embodiment of the present invention, the hydrophobic resin contained in the surface lubricating layer preferably includes at least vinyl chloride resin, more preferably vinyl chloride resin. That is, in one embodiment of the present invention, the surface lubricating layer contains vinyl chloride resin, thereby improving the film strength and durability of the surface lubricating layer. The mechanism is presumed to be as follows: The block copolymer having epoxy groups crosslinks (bonds) with each other through the ring-opening of epoxy groups, thereby improving the film strength of the surface lubricating layer. Therefore, by coexisting with the block copolymer, preferably in small amounts, the chlorine in the vinyl chloride resin is dechlorinated, promoting the ring-opening of the epoxy groups in the block copolymer. As a result, compared with the case where vinyl chloride resin does not coexist, the ring-opening and crosslinking of epoxy groups proceed rapidly, the heating time is shortened, the heating temperature is lowered, resulting in a low heat load for the substrate and the surface lubricating layer, and by shortening the heating time, it is possible to reduce costs while suppressing operation time and energy consumption, thereby improving the film strength of the block copolymer. It should be noted that the above mechanism is presumed and is not limited thereto.

[0062] The weight-average molecular weight (Mw) of the hydrophobic resin is preferably 1,000 or more, more preferably 10,000 or more, and even more preferably 30,000 or more. Furthermore, the weight-average molecular weight of the hydrophobic resin is preferably 10,000,000 or less, more preferably 500,000 or less, and even more preferably 250,000 or less. As an example, the weight-average molecular weight (Mw) of the hydrophobic resin is preferably 1,000 to 10,000,000, more preferably 10,000 to 500,000, and even more preferably 30,000 to 250,000. When the weight-average molecular weight (Mw) of the hydrophobic resin is within the above range, the cross-linking (bonding) of the block copolymers is promoted, thereby improving the stability of the surface lubricating layer.

[0063] In one embodiment of the medical device, the content (mass %) of the hydrophobic resin in the surface lubricating layer is preferably less than the content (mass %) of the block copolymer. This results in lower frictional resistance and better sliding properties. More specifically, the mixing ratio of the block copolymer to the hydrophobic resin (block copolymer: hydrophobic resin (mass ratio)) is, for example, 100:0.01 or more and less than 100:100, preferably 100:0.1 or more and 100:90 or less, more preferably 100:0.25 or more and 100:70 or less, even more preferably 100:0.5 or more and 100:50 or less, and particularly preferably 100:1 or more and 100:10 or less. When the mass ratio of the block copolymer to the hydrophobic resin is within the above range, the resulting surface lubricating layer can fully exert its durability and lubricity (sliding properties). It should be noted that although a lubricating coating may be applied separately, since the medical device formed using the medical material of the present invention (part of which includes a coating formed of medical material) has smoothness (sliding, lubricity), it is not necessary to apply a lubricating coating separately.

[0064] (Standard deviation of R value) In the medical device of the present invention, the standard deviation of the R-value of the surface lubricating layer after staining with Congo red solution, as measured by the method described in the examples, is 10 or less. Because the standard deviation of the R-value is 10 or less, the medical device of the present invention exhibits excellent sliding properties and durability. It should be noted that the standard deviation of the R-value of the surface lubricating layer can be calculated according to the method described in the examples.

[0065] The standard deviation of the R-value is an indicator for evaluating the uneven distribution of the surface lubricant layer on a substrate surface; in other words, it is an indicator for evaluating the deviation in the thickness of the surface lubricant layer. Here, a large deviation in the thickness of the surface lubricant layer means that... Figure 2 As shown, the thickness of the surface lubricating layer 2 is not constant; the difference in thickness between the thick and thin parts of the surface lubricating layer is large. The term "small deviation in the thickness of the surface lubricating layer" means that... Figure 1 As shown, the thickness of the surface lubricating layer is relatively constant, and the difference in thickness between the thick and thin parts of the surface lubricating layer is relatively small. A standard deviation of less than 10 for the R-value of the surface lubricating layer indicates minimal variation in its thickness.

[0066] Generally, a thicker surface lubricating layer results in excellent sliding properties (in other words, low sliding resistance) and high durability, while a thinner layer results in poor sliding properties (in other words, high sliding resistance) and low durability. When the standard deviation of the R-value is greater than 10, meaning the thickness of the surface lubricating layer varies greatly, portions with high sliding properties and durability coexist with portions with low sliding properties and durability. For medical devices with such surface lubricating layers, during use, forces (e.g., forces caused by friction with external surfaces) are easily applied to the thinner, less slippery portions. Furthermore, since these thinner portions also have poor durability, the surface lubricating layer may deteriorate or break. For this reason, medical devices with surface lubricating layers exhibiting large thickness variations also have poor sliding properties and durability. On the other hand, when the standard deviation of the R-value is less than 10, meaning the thickness variation of the surface lubricating layer is small, this phenomenon does not occur. With a surface lubricating layer having a small thickness deviation, since the layer thickness is constant, there are no (or few) portions with lower sliding properties than the surrounding area, and it is less likely that localized forces will be applied due to differences in sliding properties. Furthermore, since there are also no (or few) portions with lower durability than the surrounding area, it is considered that the durability of the medical device will decrease due to deterioration or damage to a portion of the surface lubricating layer. Therefore, a medical device according to one embodiment of the present invention, with a standard deviation of R-value of 10 or less, exhibits excellent sliding properties and excellent durability.

[0067] In the medical device of the present invention, the standard deviation of the R-value of the surface lubricating layer after staining with Congo red solution is 10 or less. However, in one embodiment, the R-value is preferably less than 10, more preferably 9.5 or less, and even more preferably 9.0 or less. Furthermore, the lower limit of the R-value is not particularly limited and can be 0 or more, 1 or more, or 2 or more. Because the R-value of the surface lubricating layer is within the above range, the deviation in the thickness of the surface lubricating layer becomes smaller, thereby further improving the sliding properties and durability of the medical device.

[0068] (Sliding resistance) In one embodiment of the medical device, the sliding resistance value of the surface lubricating layer during 10 sliding cycles in the sliding resistance test is preferably 8.5 gf or less, more preferably 7.5 gf or less, even more preferably 6.5 gf or less, even more preferably 6 gf or less, particularly preferably 5.5 gf or less, and most preferably 5 gf or less. Furthermore, the lower limit of the sliding resistance value of the surface lubricating layer in one embodiment of the medical device is not particularly limited, but is preferably 0.5 gf or more. Since the sliding resistance value of the surface lubricating layer is within the above range, the sliding properties of the medical device become suitable, thereby improving the durability of the medical device. The sliding resistance value of the surface lubricating layer can be calculated according to the "sliding resistance test" described in the examples.

[0069] (Durability (increase in sliding resistance)) In one embodiment of the medical device, the increase in sliding resistance during the durability test of the surface lubricating layer is preferably less than 15 gf, more preferably less than 10 gf, further preferably less than 5 gf, even more preferably less than 2.5 gf, particularly preferably less than 1 gf, and most preferably 0 gf. Furthermore, the lower limit of the increase in sliding resistance during the durability test of the surface lubricating layer in one embodiment of the medical device is not particularly limited, for example, it is 0 gf. Since the increase in sliding resistance of the surface lubricating layer is within the above range, the durability of the medical device becomes more sufficient. It should be noted that the increase in sliding resistance during the durability test of the surface lubricating layer can be calculated according to the "durability test" described in the examples.

[0070] (The unevenness of the surface lubricating layer) In one embodiment of the medical device, the less unevenness (also known as pitting) on ​​the surface of the surface lubricating layer, the better. Less unevenness means less uneven distribution of the surface lubricating layer, making it more suitable as a medical device. It should be noted that the unevenness of the surface lubricating layer can be evaluated according to the method described in the "Evaluation of the Unevenness of the Surface Lubricating Layer" section of the embodiment.

[0071] (Dynamic friction resistance value) In one embodiment of the medical device, the dynamic friction resistance values ​​(0°) of the 5th, 50th, 5th (180°), and 50th (180°) cycles are preferably 10 gf or less, more preferably 5 gf or less, further preferably 4 gf or less, particularly preferably 3 gf or less, and most preferably 2.5 gf or less. Furthermore, there are no particular limitations on the lower limits of the dynamic friction resistance values ​​(0°) of the 5th, 50th, 5th (180°), and 50th (180°) cycles, but they are preferably 0.1 gf or more. Since the dynamic friction resistance values ​​of the 5th time (0°), the 50th time (0°), the 5th time (180°), and the 50th time (180°) are all within the above range, the sliding properties of the medical device become suitable, and thus the durability of the medical device is improved.

[0072] Furthermore, in one embodiment of the medical device, the absolute values ​​of the difference between the kinetic friction resistance value (0°) of the 5th and 50th iterations, and the absolute values ​​of the difference between the kinetic friction resistance value (180°) of the 5th and 50th iterations, are preferably 10 gf or less, more preferably 5 gf or less, further preferably 2.5 gf or less, particularly preferably 1 gf or less, and most preferably 0.75 gf or less. Additionally, the lower limits of the absolute values ​​of the difference between the kinetic friction resistance value (0°) of the 5th and 50th iterations, and the absolute values ​​of the difference between the kinetic friction resistance value (180°) of the 5th and 50th iterations, are not particularly limited, but are preferably 0.01 gf or more. Since the difference (absolute value) between the kinetic friction resistance value (0°) of the 5th time and the kinetic friction resistance value (0°) of the 50th time, and the difference (absolute value) between the kinetic friction resistance value (180°) of the 5th time and the kinetic friction resistance value (180°) of the 50th time are within the above range, the sliding properties of the medical device become suitable, and the durability of the medical device is improved.

[0073] Furthermore, in one embodiment of the medical device, the absolute values ​​of the difference between the 5th dynamic friction resistance value (0°) and the 5th dynamic friction resistance value (180°) in the surface lubrication layer, and the absolute values ​​of the difference between the 50th dynamic friction resistance value (0°) and the 50th dynamic friction resistance value (180°), are preferably 5 gf or less, more preferably 1 gf or less, further preferably 0.5 gf or less, particularly preferably 0.25 gf or less, and most preferably 0.15 gf or less. Additionally, the lower limit values ​​of the absolute values ​​of the difference between the 5th dynamic friction resistance value (0°) and the 5th dynamic friction resistance value (180°) in the surface lubrication layer, and the absolute values ​​of the difference between the 50th dynamic friction resistance value (0°) and the 50th dynamic friction resistance value (180°), are not particularly limited, but are preferably 0.01 gf or more. Since the difference (absolute value) between the 5th dynamic friction resistance value (0°) and the 5th dynamic friction resistance value (180°) in the surface lubrication layer, and the difference (absolute value) between the 50th dynamic friction resistance value (0°) and the 50th dynamic friction resistance value (180°) are both within the above range, the sliding properties of the medical device become suitable, and the durability of the medical device is improved.

[0074] It should be noted that the dynamic friction resistance values ​​of the 5th time (0°), the 50th time (0°), the 5th time (180°), and the 50th time (180°) can be evaluated according to the method described in the "Determination of Dynamic Friction Resistance Value" of the embodiment.

[0075] [Manufacturing methods for medical devices] Other aspects of the present invention provide a method for manufacturing a medical device, wherein the medical device comprises a substrate layer and a surface lubricating layer supported on at least a portion of the substrate layer, the surface lubricating layer comprising a block copolymer of structural units (A) derived from a reactive monomer having an epoxy group and structural units (B) derived from a hydrophilic monomer, and a hydrophobic resin, wherein the standard deviation of the R value of the surface lubricating layer after staining with Congo red solution is 10 or less. Hereinafter, the method for manufacturing a medical device having the above-described configuration will also be referred to as "a manufacturing method according to one embodiment" or simply "manufacturing method".

[0076] One embodiment of the manufacturing method includes: a step of preparing a coating liquid ((I) preparation step), the coating liquid comprising a block copolymer having structural units (A) derived from a reactive monomer having an epoxy group and structural units (B) derived from a hydrophilic monomer, a hydrophobic resin, and a solvent; a step of coating the coating liquid onto a substrate layer ((II) coating step); and a step of heat-treating the substrate coated with the coating liquid ((III) heat-treating step). The medical device obtained by this manufacturing method not only has excellent sliding properties but also durability against loads such as wear and scratches.

[0077] In other words, one embodiment of the present invention relates to a medical device manufactured by a manufacturing method comprising the following steps: a step of preparing a coating liquid ((I) preparation step), the coating liquid comprising a block copolymer having structural units (A) derived from a reactive monomer having an epoxy group and structural units (B) derived from a hydrophilic monomer, a hydrophobic resin, and a solvent; a step of coating the coating liquid onto a substrate layer ((II) coating step); and a step of heat-treating the substrate coated with the coating liquid ((III) heat-treating step).

[0078] It should be noted that in the manufacturing method of medical devices according to one embodiment of the present invention, the terms such as block copolymer, hydrophobic resin, and substrate layer are the same as those described in the above items, and therefore the description is omitted here.

[0079] (I) Preparation process In this step, a coating solution comprising a block copolymer, a hydrophobic resin, and a solvent is prepared. Here, in this step, the coating solution can be prepared by mixing the block copolymer, the hydrophobic resin, and the solvent. Alternatively, a coating solution comprising a block copolymer, a hydrophobic resin, and a solvent can be purchased and used.

[0080] The preferred method is described in detail below for the case where a coating liquid is prepared by mixing a block copolymer, a hydrophobic resin, and a solvent.

[0081] (Preparation of coating solution) The coating solution was prepared using the aforementioned block copolymer, hydrophobic resin, and solvent. Furthermore, the PVC remains stable in the coating solution (at room temperature) and does not undergo dechlorination. Therefore, in the solution state, almost or completely no ring-opening (crosslinking reaction) of the epoxy groups occurs, and the viscosity of the coating solution remains almost or completely unchanged. Consequently, it exhibits excellent workability.

[0082] There are no particular restrictions on the order or method of adding the block copolymer, hydrophobic resin, and solvent. The components can be added all at once, separately, in stages, or continuously. Furthermore, there are no particular restrictions on the mixing method; known methods can be used. Methods for preparing the coating liquid include sequentially adding the hydrophobic resin and block copolymer to the solvent, sequentially adding the block copolymer and hydrophobic resin to the solvent, or adding the hydrophobic resin and block copolymer to the solvent all at once. It is preferable to sequentially add the hydrophobic resin and block copolymer to the solvent, or sequentially add the block copolymer and hydrophobic resin to the solvent. Additionally, if necessary, the above additions can be carried out while stirring. Alternatively, the mixture can be stirred after the above additions.

[0083] The solvent used in the preparation of the coating solution is not particularly limited as long as it can dissolve the block copolymer, hydrophobic resin (and other components if other components are used), and can be appropriately selected according to the type of block copolymer, hydrophobic resin (and other components if other components are used). From the viewpoint of high solubility, it is preferable to use: alcohol solvents such as methanol, ethanol, isopropanol, and butanol; organic solvents such as dichloromethane, chloroform, carbon tetrachloride, tetrahydrofuran (THF), dimethyl sulfoxide, N,N-dimethylformamide (DMF), dioxane, and benzene. These can be used alone or in mixtures of two or more (in the form of mixed solvents).

[0084] In the above, the solvent used in the preparation of the coating solution preferably includes one or more solvents selected from the group consisting of tetrahydrofuran (THF), N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO), and more preferably includes one or more solvents selected from the group consisting of tetrahydrofuran (THF) and N,N-dimethylformamide (DMF).

[0085] Furthermore, when using two or more solvents in the preparation of the coating solution, it is preferable that all two or more solvents are capable of dissolving the hydrophobic resin, and that the two or more solvents include both good solvents and poor solvents for the block copolymer. Examples of good solvents with high solubility for the block copolymer include N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Examples of poor solvents with relatively low solubility for the block copolymer include tetrahydrofuran (THF). It is further preferable that the solvent used in the preparation of the coating solution includes both N,N-dimethylformamide (DMF) and tetrahydrofuran (THF). Because the solvent used in the preparation of the coating solution includes both good and poor solvents, deviations in the thickness of the surface lubricating layer can be suppressed. This is believed to be because, since the solvent includes both good and poor solvents, even if the concentration of the block copolymer in the coating solution is increased, the viscosity of the adjusted coating solution can be kept low. Generally, block copolymers used for coatings with high slip properties (such as surface lubricating layers) have long hydrophilic groups with large molecular chains and high molecular weights. Therefore, increasing the concentration of the block copolymer in the coating solution tends to increase the viscosity of the coating solution. Thus, to produce a homogeneous solution of the block copolymer with a viscosity suitable for impregnation, spraying, and other methods, the concentration of the block copolymer needs to be reduced. When the concentration of the block copolymer in the coating solution is low, it is difficult to obtain a thick coating (such as a surface lubricating layer) during film formation. Furthermore, at low concentrations, the hydrophilic groups of the block copolymer extend significantly in the coating solution, and during heating and drying processes, these hydrophilic groups become entangled, leading to uneven distribution (thickness inconsistency) in the coating (such as a surface lubricating layer). Conversely, coating solutions with high block copolymer concentrations and low viscosity are suitable for impregnation, spraying, and other methods, and thick coatings are easily obtained during film formation. Furthermore, the molecular chains of the hydrophilic groups in the block copolymer in the coating solution have relatively small extensions, resulting in less entanglement of molecular chains during the heating and drying processes. Therefore, it is believed that this can suppress uneven distribution (thickness unevenness) of the coating (such as a surface lubricating layer). It should be noted that the above mechanism is speculative and does not limit the invention.

[0086] When the solvent used in the preparation of the coating solution includes both tetrahydrofuran (THF) and N,N-dimethylformamide (DMF), the mixing ratio (mass ratio) of tetrahydrofuran (THF) to N,N-dimethylformamide (DMF) can be appropriately adjusted to obtain slip properties and durability, and is not particularly limited. However, in order to uniformly mix the polymer, the mass ratio of N,N-dimethylformamide (DMF) to tetrahydrofuran (THF) is, for example, 0.5 or more, 0.8 or more, 1.0 or more, 3.0 or more, 5.0 or more, 7.0 or more, or 9.0 or more. Alternatively, this mass ratio is, for example, 20.0 or less, 15.0 or less, 10.0 or less, 8.0 or less, 6.0 or less, 4.0 or less, or 2.0 or less.

[0087] The concentration of the block copolymer in the coating solution is not particularly limited. From the viewpoint of further improving coatability, the lubricity of the surface lubricating layer, and durability, 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, even more preferably 3 to 10% by mass, particularly preferably greater than 3% by mass and less than 8% by mass; in the example, it is 5% by mass. When the concentration of the block copolymer is within the above range, the lubricity and durability of the obtained surface lubricating layer can be fully utilized. Furthermore, a uniform surface lubricating 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 preferred from the perspective of operability (e.g., ease of coating) and production efficiency. However, even if it exceeds the above range, it can be fully utilized as long as it does not affect the effect of the present invention.

[0088] The concentration of the hydrophobic resin in the coating solution is not particularly limited. From the viewpoint of the lubricity (sliding properties) of the surface lubrication layer, the less hydrophobic resin added, the better. On the other hand, from the viewpoint of the durability (sliding durability) of the surface lubrication layer, it is preferable to add hydrophobic resin to a certain extent. Considering the above aspects, the concentration of hydrophobic resin in the coating solution is preferably 0.001% by mass or more and less than 12% by mass, more preferably 0.005% by mass or more and less than 4.0% by mass, further preferably 0.01% by mass or more and less than 0.5% by mass, particularly preferably 0.01 to 0.2% by mass, and 0.1% by mass in the example. When the concentration of hydrophobic resin is within the above range, the lubricity (sliding properties) of the surface lubrication layer is sufficiently ensured, and the crosslinking of the block copolymer is sufficiently carried out without being excessive (crosslinking can be moderately promoted). Therefore, the lubricity (sliding properties) and durability of the obtained surface lubrication layer can be fully utilized. However, even if it exceeds the above range, it can be fully utilized as long as it does not affect the effect of the present invention.

[0089] Furthermore, from the viewpoints of further improving durability (slip durability), coatability, and the lubricity (slipability) of the surface lubricating layer, the content (mass%) of the hydrophobic resin in the coating liquid is preferably less than the content (mass%) of the block copolymer. A more specific mixing ratio of the block copolymer to the hydrophobic resin (block copolymer: hydrophobic resin (mass ratio)) can be the mass ratio described in the "Surface Lubricating Layer" section above.

[0090] (II) Coating process In this process, the coating liquid prepared in the above (I) preparation process is applied to the substrate layer to form a coating film (coating layer) on the substrate layer.

[0091] There are no particular limitations on the method of applying the coating liquid to the substrate layer. Known methods such as coating-printing, dipping, spraying, spin coating, sponge coating with mixed solution, rod coating, mold coating, reverse coating, comma coating, gravure coating, and doctor blade coating can be used. Among these, dipping is preferred.

[0092] When using the immersion method, there is no particular limitation on the lifting speed after immersing the substrate of the conduit in the coating solution, but it is preferably 1 mm / s to 30 mm / s, more preferably 2 mm / s to 20 mm / s, and even more preferably 2.5 mm / s to 15 mm / s. When the lifting speed is within the above range, the desired amount of coating solution can be applied to the outer surface of the substrate of the conduit.

[0093] It should be noted that when forming a surface lubricating layer on the narrow inner surface of catheters, guidewires, injection needles, etc., the substrate layer can be immersed in the coating solution, and the system can be depressurized to remove bubbles. By depressurizing to remove bubbles, the solution can quickly penetrate to the narrow inner surface, promoting the formation of the surface lubricating layer.

[0094] In addition, when a surface lubricating layer is formed only on a portion of the substrate layer, the surface lubricating layer can be formed on the desired surface portion of the substrate layer by immersing only a portion of the substrate layer in the coating liquid and applying the coating liquid to that portion of the substrate layer.

[0095] It should be noted that, in terms of the structure of medical devices, when both the outer and inner surfaces of cylindrical devices need to have a surface lubrication layer, the immersion method is preferred from the perspective of being able to coat both the outer and inner surfaces in one go.

[0096] The coating amount of the coating liquid is preferably such that the thickness of the resulting film (surface lubricating layer) is 0.1 to 10 μm, more preferably 0.5 to 5 μm, and even more preferably 1 to 3 μm; in the example, it is 1.5 μm. If the coating amount is such that the thickness of the film (surface lubricating layer) is 0.1 μm or more, the durability of the resulting film (surface lubricating layer) can be sufficiently achieved. Furthermore, if the coating amount is such that the thickness of the film (surface lubricating layer) is 10 μm or less, the surface of the film (surface lubricating layer) becomes less sticky, and the manufacturing process becomes easier.

[0097] (III) Heat treatment process In one embodiment of the manufacturing method of a medical device, after forming a coating film (coating layer) by coating a coating liquid onto a substrate layer of the medical device in the above-described coating step (II), a step of performing a heat treatment on the substrate is included. In other words, the medical device according to one embodiment of the present invention can be manufactured by a manufacturing method having the following steps: after forming a coating film (coating layer) by coating a coating liquid onto a substrate layer in the above-described coating step, the substrate is subjected to a heat treatment. By performing the heat treatment, the surface lubrication layer becomes a layer with both excellent durability and sliding properties, and the durability and sliding properties of the medical device also become excellent.

[0098] The heating temperature range in the heat treatment process involved in one embodiment is not particularly limited, but is preferably 50°C to 200°C, more preferably 90°C to 180°C, and 130°C in an example. By maintaining (performing heat treatment) within such a temperature range, a robust surface lubricating layer is formed.

[0099] Furthermore, the heating time in the heat treatment process involved in one embodiment is not particularly limited, but it is preferably 15 minutes to 20 hours, more preferably 30 minutes to 12 hours, and even more preferably 45 minutes to 6 hours. In the example, it is 1 hour or 3 hours. By setting the time to such a duration, the crosslinking reaction in the block copolymer is effectively promoted, forming a more robust coating layer (surface lubrication layer), thus enabling the maintenance of high surface lubricity (slipability) for a longer period of time.

[0100] In one embodiment of the manufacturing method, a heat treatment process in which the heating temperature is gradually increased can also be performed. By performing a heat treatment process in which the heating temperature is gradually increased, the durability and surface lubricity (slipability) of the surface lubricating layer and the medical device are improved.

[0101] Here, the "temperature gradually increasing" heating process preferably includes a step of maintaining a predetermined heating temperature for a certain period of time, and a step of continuously increasing the temperature until the predetermined heating temperature is reached. Furthermore, in one embodiment of the "temperature gradually increasing" heating process, it is preferable to include a step of maintaining a predetermined heating temperature for a certain period of time, and a step of continuously increasing the temperature until the predetermined heating temperature is reached.

[0102] (IV) Other processes In one embodiment of the manufacturing method, a drying step may be included before the aforementioned heat treatment step. During the drying step, excess solvent is removed, making subsequent heat treatment steps more efficient. The temperature of this drying step is not particularly limited, but it is preferably performed at 10°C or higher and less than 50°C, more preferably at 20-30°C. Furthermore, the drying time is not particularly limited, but it is preferably 15 minutes to 20 hours, more preferably 30 minutes to 12 hours. Additionally, there are no limitations on the pressure conditions during drying; it can be performed under normal atmospheric pressure, or under pressure or depressurization.

[0103] As means (apparatus) for performing the above-mentioned heat treatment and drying processes, for example, an oven or a vacuum dryer can be used. Furthermore, if the drying method in the drying process is natural drying, no special drying means (apparatus) is required.

[0104] [Method for determining non-uniform distribution] One aspect of the present invention is a method for measuring non-uniformity, wherein the non-uniformity of the surface lubricating layer in a medical device having a surface lubricating layer is evaluated by using the standard deviation of the R-value of the surface lubricating layer after staining with Congo red solution. This method allows for the evaluation of the non-uniformity of the surface lubricating layer on the substrate layer of the medical device, i.e., the deviation in the thickness of the surface lubricating layer. When the standard deviation of the R-value of the surface lubricating layer measured by this non-uniformity measurement method is 10 or less, it can be evaluated as having low non-uniformity of the surface lubricating layer, i.e., low deviation in the thickness of the surface lubricating layer. Furthermore, medical devices evaluated in this way can be evaluated as having excellent sliding properties and durability. It should be noted that the standard deviation of the R-value of the surface lubricating layer can be calculated according to the method described in "Standard Deviation of R-value of Surface Lubricating Layer" of the embodiment.

[0105] [Uses of medical devices] The medical devices manufactured by the method of the present invention are instruments used in contact with bodily fluids, blood, etc. In aqueous liquids such as bodily fluids and saline, the surface has slipperiness, which improves operability and reduces damage to tissues and mucous membranes. Specifically, examples include catheters, guidewires, and indwelling needles used intravascularly. In addition, the following medical devices are also shown.

[0106] (a) Gastric tubes, feeding tubes, and tube feeding tubes, which are inserted or left in the digestive organs through the mouth or nose.

[0107] (b) Catheters that are inserted or left in the respiratory tract or trachea through the mouth or nose, such as oxygen catheters, oxygen delivery tubes, endotracheal tubes or cuffs, tracheostomy tubes or cuffs, endotracheal suction catheters, etc.

[0108] (c) Catheters such as urethral catheters, urinary catheters, and urethral balloon catheters that are inserted into or left in the urethra or ureter.

[0109] (d) Catheters such as suction catheters, drainage catheters, and rectal catheters that are inserted into or left in various body cavities, organs, and tissues.

[0110] (e) Catheters inserted into or left in blood vessels, such as indwelling needles, IVH catheters, thermodilution catheters, angiography catheters, vasodilators and dilators or guides, or guidewires and catheterization needles used with these catheters.

[0111] (f) Artificial trachea, artificial bronchus, etc.

[0112] (g) Medical devices used for extracorporeal circulation therapy (artificial lungs, artificial hearts, artificial kidneys, etc.) and their circuits.

[0113] Example The effects of the present invention will be illustrated using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples. It should be noted that, unless otherwise specified, the operation in the following examples is carried out at room temperature (25°C). In addition, unless otherwise specified, "%" and "parts" refer to "mass %" and "parts by mass," respectively.

[0114] Synthesis example 1 The following reaction is carried out to produce block copolymers (1).

[0115] [Chemical Formula 1] 29.7 g of triethylene glycol was added dropwise to 72.3 g of adipic acid chloride at 50 °C, and hydrochloric acid was removed under reduced pressure at 50 °C for 3 hours to obtain a low-polyester. Next, 4.5 g of methyl ethyl ketone was added to 22.5 g of the obtained low-polyester, and this mixture was then 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. The reaction was carried out at -5 °C for 20 minutes. The resulting product was repeatedly washed with water and methanol, and then dried to obtain a polyperoxide (PPO) with multiple peroxide groups within the molecule.

[0116] Next, 0.5 g of PPO, 9.5 g of glycidyl methacrylate (GMA), and 30 g of benzene as a solvent were stirred at 80 °C under reduced pressure for 2 hours and polymerized. The polymerized product was then reprecipitated with diethyl ether to obtain polyglycidyl methacrylate (PPO-GMA) with multiple peroxide groups in the molecule.

[0117] Next, 0.42 g of the obtained PPO-GMA (equivalent to 3.0 mmol of GMA) was used as a polymerization initiator and dissolved in chlorobenzene along with 10.0 g (101 mmol) of N,N-dimethylacrylamide (DMAA). Polymerization was carried out under a nitrogen atmosphere at 75°C for 7 hours to obtain the block copolymer (1). Using... 1 ¹H-NMR was used to determine the DMAA:GMA ratio of the prepared block copolymer (1), and the result was that the DMAA:GMA ratio (i.e., the molar ratio of hydrophilic to hydrophobic sites in the block copolymer) was 35:1 (molar ratio). In addition, the viscosity of a 1 wt% chloroform solution of the obtained block copolymer (1) was measured at 30°C using a type B rotational viscometer (Brookfield Corporation, device name: DV-I Prime), and the result was 11.8 mPa·s.

[0118] Example 1 Polyvinyl chloride (manufactured by FUJIFILM Wako Pure Chemical Corporation, Mw=50,000 or higher) was dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and tetrahydrofuran (THF) (DMF:THF=1:1 (mass ratio)) to a final concentration of 0.1% in the coating solution (referred to as mixed solution (1) in Table 1). The block copolymer (1) synthesized in Synthesis Example 1 was added to the above mixed solution (1) to a final concentration of 5% by mass and dissolved to prepare coating solution (1).

[0119] A tube (outer diameter: 2.80 mm) made of nylon elastomer (Evonik, VESTAMID E47-S1) as the substrate layer was immersed in the above coating liquid (1) and pulled upward at a lifting speed of 5 mm / s. It was then dried at room temperature (25°C) for 1 hour, thereby forming a coating film on the tube surface. Then, the tube with the coating film (coating forming tube (1)) was placed in an oven and the temperature inside the oven was raised from room temperature to 130°C without stopping the temperature rise. It was then kept at 130°C for 1 hour to perform heat treatment. It was then removed from the oven to produce the sample (1) of Example 1 with a coating layer (surface lubrication layer) (film thickness: 1.5 μm) on the surface containing a crosslinked copolymer derived from block copolymers.

[0120] Comparative Example 1 The block copolymer synthesized in Synthesis Example 1 was added to N,N-dimethylformamide (DMF) and dissolved to prepare the coating solution, so that the final concentration in the coating solution was 3% by mass.

[0121] A tube (outer diameter: 2.46 mm) made of polyester elastomer (PELPRENE E-450B, manufactured by TOYOBO MC Corporation) as the substrate layer was immersed in the above coating solution and pulled at a speed of 5 mm / s. It was then dried at room temperature (25°C) for 1 hour to form a coating film on the tube surface. The tube with the coating film (coating forming tube (2)) was then placed in an oven and the temperature inside the oven was raised to 130°C without stopping the temperature rise. It was then kept at 130°C for 3 hours to perform heat treatment. The tube was then removed from the oven to produce a sample of Comparative Example 1 (Comparative Sample (1)) with a coating layer (surface lubrication layer) (film thickness: 0.5 μm to 1.0 μm) on the surface containing a crosslinked copolymer derived from block copolymers.

[0122] Comparative Example 2 The block copolymer synthesized in Synthesis Example 1 was added to N,N-dimethylformamide (DMF) and dissolved to prepare the coating solution, so that the final concentration in the coating solution was 5% by mass.

[0123] Then, a tube (outer diameter: 2.80 mm) was made of nylon elastomer (manufactured by Evonik, VESTAMID E47-S1). In addition, the tube with the coating (coating forming tube (3)) was placed in an oven and the temperature inside the oven was raised to 130°C without stopping the temperature rise. Then it was kept at 130°C for 1 hour. Otherwise, the sample of Comparative Example 2 (comparative sample (2)) was made in the same way as Comparative Example 1.

[0124] [Standard deviation of the R-value of the surface lubricating layer] For the sample (1) prepared in Example 1 above, and the comparative samples (1) and (2) prepared in Comparative Examples 1 and 2 above (hereinafter, sample (1), comparative sample (1) and comparative sample (2) are each referred to as "sample"), the standard deviation of the R value of the surface lubricating layer was measured and calculated according to the following method. The results are shown in Table 1.

[0125] <Staining Methods> Each sample was stained using the following staining method.

[0126] 1. Dissolve Congo red reagent (manufactured by FUJIFILM Wako Pure Chemical Corporation, Congo red) in RO water to a concentration of 2% by mass to prepare a staining solution.

[0127] 2. Immerse the sample in the staining solution for 2 minutes.

[0128] 3. Remove the sample from the staining solution and wash it with running water (tap water) for 1 minute.

[0129] 4. Dry the sample. Drying is carried out by air drying or vacuum drying.

[0130] <Filming Method> Using a digital microscope, photograph each sample after staining using the above staining method according to the following imaging method.

[0131] 1. Fix the illumination, lens magnification, and other conditions during shooting.

[0132] Device Name: DSX1000 (Made by Evident) Objective lens: DSX10-XLOB10X Overall odds: 164× Observation method: Simple polarization Coaxial incident illumination: 10000 PO: 90 ISO sensitivity: 400 Image size: 1200×1200.

[0133] It should be noted that, since the image was taken of the tube, the top and bottom parts of the field of view were beyond the depth of focus, resulting in a blurred image. Therefore, the top and bottom parts were cropped from the captured image (1200×1200) and the size was adjusted (1200×675).

[0134] 2. Fix the sample with its central axis roughly horizontal, and fix the camera at the 50mm position in the middle of the 100mm coating.

[0135] 3. Adjust the sample such that it is located at the center of the captured image, perform focusing and obtain an image. This image is designated as the 0° image.

[0136] 4. Rotate the sample 90° circumferentially around the central axis, and obtain an image by the same method as steps 1. to 3. above. This image is designated as the 90° image.

[0137] 5. Rotate the sample further 90° circumferentially around the central axis, and obtain an image by the same method as steps 1. to 3. above. This image is designated as the 180° image.

[0138] 6. Rotate the sample further 90° circumferentially around the central axis, and obtain an image by the same method as steps 1. to 3. above. This image is designated as the 270° image.

[0139] <Method for calculating average R-value and standard deviation of R-values> Based on each image obtained by the aforementioned shooting method, the average R-value and standard deviation of R-values for each sample are calculated by the following method.

[0140] [Output of CSV Data] For the 0° image, 90° image, 180° image and 270° image of each sample, CSV data is obtained in accordance with the following steps.

[0141] 1. Open the image data (.jpg) in the image processing software "ImageJ" (freeware, available for download from the following URL: https: / / imagej.net / Welcome).

[0142] 2. Select "Histogram" under the tab "Analyze".

[0143] 3. In the displayed histogram, select "RGB" and set the histogram to display only the red (Red) channel.

[0144] 4. Select the "List" button, select "Save As" under the tab "File", and output the data in CSV format.

[0145] [Calculation of Average R-value] Based on the CSV data output as described above, the average R-value of each sample is calculated. Here, in the CSV data, the value represents the R-value (0 to 255), and the count represents the number (number of pixels) of each R-value in the image data.

[0146] 1. Sum the count values ​​of each value in the 0°, 90°, 180°, and 270° images, and use this sum as the total count (e.g., ...). Figure 3 As shown, with the count of 0° images being 1, 90° images being 2, 180° images being 2, and 270° images being 3 in value=2, the total count in value=2 is 8.

[0147] 2. Multiply each value by the total count of all values ​​to calculate the sum of all R values ​​(the calculated value is called the point) (e.g., ...). Figure 3 As shown, when the total count in value = 2 is 8, the value of the points in value = 2 is 8 × 2, which is 16.

[0148] 3. Add up all the total counts from 0 to 255 (the calculated value is called the total pixel).

[0149] 4. Add up all the pixels from 0 to 255 and divide by the total number of pixels to calculate the average R value.

[0150] [Calculation of the standard deviation of the R value] Based on the average of the calculated R values, the standard deviation of the R values ​​for each sample was calculated. The results are shown in Table 1.

[0151] 1. Calculate the "average value - R value" (deviation) for each value.

[0152] 2. Square the deviations calculated in 1. (deviation^2).

[0153] 3. Using the deviation^2 calculated in 2., calculate "deviation^2 × total count" (points converted to deviation^2) for each value.

[0154] 4. Add up all the pixel conversion deviations^2, and divide the resulting value by the total number of pixels (variance).

[0155] 5. The value obtained by taking the square root of the variance (the square root of the variance) is used as the standard deviation of the R value.

[0156] [Evaluation of the surface texture of the surface lubricating layer] The surface roughness (also known as pitting) of the surface lubricating layer was evaluated according to the following method for sample (1) prepared in Example 1 and comparative samples (1) and (2) prepared in Comparative Examples 1 and 2.

[0157] The surface of each sample was touched by hand after being immersed in tap water for 1 minute, and the surface texture was evaluated by sensory evaluation according to the following evaluation criteria. The results are shown in Table 1.

[0158] (Evaluation Criteria) ○: The surface texture is not noticeable; △: The surface has a slight unevenness that can be felt; and ×: The unevenness of the surface can be clearly felt.

[0159] [Sliding resistance test and durability test] The sliding resistance and durability of the sample (1) prepared in Example 1 and the comparative samples (1) and (2) prepared in Comparative Examples 1 and 2 were evaluated according to the following steps.

[0160] (Sliding resistance test) Each sample was placed in a clamping testing machine (OAKRIVER TECHNOLOGY, DL1000) while immersed in tap water, and subjected to 10 sliding cycles under conditions of a clamping force of 500 gf, a test speed of 8.3 mm / s, and a test stroke of 25 mm (clamping pad material: silicone, clamping pad height: 12.35 mm). The sliding resistance was then evaluated by measuring the values ​​at each of the 10 sliding cycles (the sliding resistance value at each of the 10 sliding cycles). Specifically, the average of the measured values ​​from 5 mm to 20 mm within the 25 mm test stroke at the 10th sliding cycle was calculated as the sliding resistance value (gf).

[0161] If the sliding resistance value (gf) during the above 10 sliding operations is 8.5gf or less, it is judged to have the sliding properties required for a medical device; if it is 7.5gf or less, it is judged to have sliding properties more suitable for a medical device. The results are shown in Table 1. In addition, the evaluation criteria are as follows.

[0162] (Evaluation Criteria) ○: Below 7.5gf; △: Greater than 7.5gf and less than 8.5gf; and ×: Greater than 8.5gf.

[0163] (Durability test) Each sample was placed in a clamping tester (OAKRIVER TECHNOLOGY, DL1000) while immersed in tap water, and subjected to 50 sliding cycles under conditions of a clamping force of 500 gf, a test speed of 8.3 mm / s, and a test stroke of 25 mm (clamping pad material: silicone, clamping pad height: 12.35 mm). Then, the difference between the measured value at the 50th sliding cycle and the measured value at the 10th sliding cycle was calculated to determine the increase in sliding resistance, thereby evaluating durability. The measured value at the 10th sliding cycle was calculated using the same method as the sliding resistance test described above. The measured value at the 50th sliding cycle was also calculated using the same method; specifically, the average of the measured values ​​between 5 mm and 20 mm within the 25 mm test stroke at the 50th sliding cycle was calculated as the measured value (gf) at 50 sliding cycles. In this durability test, the smaller the difference between the measured value at the 50th sliding cycle and the measured value at the 10th sliding cycle, the better the durability. It should be noted that when the result is negative, it should be set to 0gf. Additionally, the evaluation criteria are shown below, and the results are presented in Table 1.

[0164] (Evaluation Criteria) ○: Less than 5gf; ×: 5gf or more.

[0165] [Table 1] The standard deviation of the R-value of sample (1) prepared in Example 1 was less than 10, such as 8.9. On the other hand, the standard deviation of the R-value of comparative samples (1) and (2) prepared in Comparative Examples 1 and 2 was greater than 10, such as 15.1 and 10.2, respectively. Based on these results, it can be seen that compared with comparative samples (1) and (2) of the Comparative Examples, sample (1) of Example 1 had less uneven distribution of the surface lubricating layer, that is, less deviation in the thickness of the surface lubricating layer. In addition, sample (1) of Example 1 showed excellent sliding performance and durability, while comparative sample (1) of Comparative Example 1 had poor sliding performance and comparative sample (2) of Comparative Example 2 had poor durability. Based on these results, it is believed that sample (1) of Example 1 showed excellent sliding performance and durability because of less uneven distribution of the surface lubricating layer, that is, smaller deviation in the thickness of the surface lubricating layer. On the other hand, based on the results of the comparative samples of the Comparative Examples, it is believed that when there is more uneven distribution of the surface lubricating layer and a larger deviation in thickness, at least one of sliding performance and durability is poor.

[0166] [Evaluation of kinetic friction resistance value] First, the sample (2) of Example 2 was prepared by the following method.

[0167] Example 2 The substrate layer was made of polyester elastomer (PELPRENE E-450B, manufactured by TOYOBO MC Corporation) to form a tube (outer diameter: 2.46 mm). In addition, the tube with the coating (coating forming tube (4)) was placed in an oven and the temperature inside the oven was raised to 130°C without stopping the temperature rise. Then it was kept at 130°C for 3 hours. Otherwise, the sample (2) of Example 2 was made in the same way as in Example 1. Here, the standard deviation of the R value of the surface lubricating layer of sample (2) was calculated according to the method described in the "Standard deviation of R value of surface lubricating layer" column above, and the result was 7.1.

[0168] (Determination of dynamic friction resistance value) Next, for sample (2) and comparative sample (1) prepared in Comparative Example 1, the following method was used... Figure 4 The friction tester shown (Trinity Labs, Handy Tribo Master TL201) 20 measures the dynamic friction resistance value, thereby evaluating sliding performance and durability (slip maintenance).

[0169] The sample (2) was fixed in the petri dish 12 and immersed in water 17 to a height that completely submerged the sample (2). The petri dish 12 was placed in Figure 4 The moving stage 15 of the friction measuring machine 20 shown. The PEEK terminals ( The sample (2) (10mm, R1mm) 13 is in contact with the sheet, and a load of 100g is applied to the terminal 14. The moving stage 15 is moved horizontally back and forth 50 times with a sliding distance of 25mm and a sliding speed of 16.7mm / sec. At this time, the dynamic friction resistance (gf) of each time is measured, and the average value of the dynamic friction resistance (gf) of each time is calculated as the dynamic friction resistance value (0°) (gf) of each time. Next, the sample (2) is rotated 180° in the circumferential direction, and the dynamic friction resistance value (180°) (gf) of each time is calculated in the same way as above. The dynamic friction resistance values ​​(0°) (gf) and (180°) (gf) of the sample (2) for the 5th and 50th reciprocating cycles are shown in Table 2.

[0170] In addition, following the same method as described above, the dynamic friction resistance values ​​(0°) (gf) and (180°) (gf) for each reciprocating motion were also calculated for the comparative sample (1) prepared in Comparative Example 1. The dynamic friction resistance values ​​(0°) (gf) and (180°) (gf) for the 5th and 50th reciprocating motions of the comparative sample (1) are shown in Table 2.

[0171] [Table 2] As shown in Table 2 above, compared with comparative sample (1), the dynamic friction resistance values ​​(0°) and (180°) of sample (2) of Example 2 were low in the 5th and 50th tests. These results indicate that Example 2 has superior sliding properties compared with Comparative Example 1.

[0172] Furthermore, the dynamic friction resistance values ​​(0°) and (180°) of sample (2) in Example 2 were both small differences between the 5th and 50th times (dynamic friction resistance value (0°) was 0.3 gf and dynamic friction resistance value (180°) was 0.53 gf). On the other hand, in comparative sample (1), although the difference between the 5th and 50th times of dynamic friction resistance value (0°) was small, the difference between the 5th and 50th times of dynamic friction resistance value (180°) was large (dynamic friction resistance value (0°) was 0.27 gf and dynamic friction resistance value (180°) was 16.86 gf). This result indicates that, compared with comparative example 1, sample (2) of Example 2 not only has excellent sliding properties but also excellent durability.

[0173] Furthermore, in sample (2) of Example 2, the difference between the dynamic friction resistance value (0°) and the dynamic friction resistance value (180°) was 0.13 gf in the 5th time and 0.10 gf in the 50th time, both small. On the other hand, in comparative sample (1), the difference between the dynamic friction resistance value (0°) and the dynamic friction resistance value (180°) in the 5th time was 1.16 gf and the difference in the 50th time was 17.75 gf, becoming large values. Generally speaking, the value of the dynamic friction resistance of the surface lubricating layer depends on the thickness of the surface lubricating layer. When the layer is thick, the dynamic friction resistance value is low, and when the layer is thin, the dynamic friction resistance value is high. That is, when the difference between the dynamic friction resistance value (0°) and the dynamic friction resistance value (180°) is large, it indicates that the difference in the thickness of the surface lubricating layer is large, and when the difference between the dynamic friction resistance value (0°) and the dynamic friction resistance value (180°) is small, it indicates that the difference in the thickness of the surface lubricating layer is small. In this respect, since the difference between the dynamic friction resistance value (0°) and the dynamic friction resistance value (180°) of sample (2) in Example 2 is small, while the difference in Comparative Example 1 is large, it can be considered that the difference in the thickness of the surface lubricating layer in Example 2 is small (i.e., the thickness deviation is small), and the difference in the thickness of the surface lubricating layer in Comparative Example 1 is large (i.e., the thickness deviation is large). These results confirm the evaluation results in "Standard deviation of R value of surface lubricating layer".

[0174] This application is based on Japanese Patent Application No. 2024-129927, filed on August 6, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0175] Explanation of reference numerals in the attached figures 10 catheters, 1. Substrate layer 2. Surface lubrication layer 3. Inner cavity 12 Petri dishes, 13 PEEK terminals, 14 Load, 15 mobile stations 16 samples 17. Water.

Claims

1. A medical device having a substrate layer and a surface lubricating layer supported on at least a portion of the substrate layer, wherein, The surface lubricating layer comprises a block copolymer having structural units (A) derived from reactive monomers with epoxy groups and structural units (B) derived from hydrophilic monomers, and a hydrophobic resin. The standard deviation of the R value of the surface lubricating layer after staining with Congo red solution is less than 10.

2. The medical device as described in claim 1, wherein, The ratio (molar ratio) of the structural unit (A) derived from the reactive monomer with an epoxy group to the structural unit (B) derived from the hydrophilic monomer in the block copolymer is 1:20 to 1:

50.

3. The medical device as described in claim 1 or 2, wherein, The content (mass%) of the hydrophobic resin in the surface lubricating layer is less than the content (mass%) of the block copolymer.

4. The medical device as described in claim 1 or 2, wherein, The hydrophobic resin is polyvinyl chloride (PVC) resin.

5. The medical device as described in claim 1 or 2, wherein, The reactive monomer having an epoxy group comprises at least one selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexyl methyl acrylate, 3,4-epoxycyclohexyl methyl methacrylate, β-methyl glycidyl methacrylate, and allyl glycidyl ether.

6. The medical device as described in claim 1 or 2, wherein, The hydrophilic monomer comprises at least one selected from the group consisting of N,N-dimethylacrylamide, acrylamide, 2-hydroxyethyl methacrylate and N-vinylpyrrolidone.

7. The medical device as described in claim 1 or 2, wherein, The sliding resistance value of the surface lubricating layer during 10 sliding cycles in the sliding resistance test is below 8.5gf.

8. Method for determining non-uniform distribution, wherein, The non-uniform distribution of the surface lubricating layer in medical devices with a surface lubricating layer was evaluated by using the standard deviation of the R value of the surface lubricating layer after staining with Congo red solution.

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