JP2013244713A - Laminate and medical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate which prevents wear or peeling due to friction or the like during insertion, when the strength of a hydrophilic resin film and crosslinked film is insufficient, and exhibits high surface lubricity and excellent durability of the lubricity by increasing durability of the lubricity while maintaining excellent lubricity, so as to solve the following problems: when strength is improved by increasing crosslink density of the crosslinked film and the crosslink density of the film is increased so as to obtain sufficient strength, hydrophilicity is degraded and lubricity can not be obtained, and to provide a medical device provided with the laminate.SOLUTION: A laminate includes a base material and a lubrication layer which covers a surface of the base material. The lubrication layer contains cellulose fiber and hydrophilic resin. A medical device is provided with the laminate.

Description

  The present invention relates to a laminate including a lubricating layer containing a hydrophilic resin and a medical device including the laminate.

Medical devices that are inserted into the body, such as the trachea, gastrointestinal tract, urethra, and other body cavities and tissues, are placed in the tissue so that they can be reliably inserted to the target site without damaging the tissue. There is a need for safety that does not cause tissue damage or inflammation due to friction.
In response to such demands, it is possible to apply a lubricating liquid such as silicone oil, olive oil, glycerin or the like to the surface of a medical device, or to apply a low friction resin such as a silicone resin or a fluorine resin to impart lubricity. is there. However, in these methods, the lubricating liquid may flow down from the surface or the low friction resin may be peeled off to maintain the lubricity.
In addition, a method for forming a hydrophilic resin film by coating a hydrophilic resin on the surface of a medical device, and a method for forming a crosslinked film by further crosslinking the coated hydrophilic resin have been proposed. For example, in Patent Document 1, as a method for imparting excellent surface lubricity regardless of the material of a base material constituting a medical device, a base material is prepared by reacting a polymer having an acid anhydride group with a polyol on the surface of the base material. A method is disclosed in which a crosslinked coating is formed on the surface and then immersed in an aqueous medium.

Japanese Patent No. 3776195

The hydrophilic resin film and the crosslinked film formed using the hydrophilic resin as described above are wetted by body fluids and exhibit lubricity. In particular, the method of forming a crosslinked film as described in Patent Document 1 is supposed to provide excellent surface lubricity regardless of the material of the base material constituting the medical device.
However, a medical device provided with a hydrophilic resin film or a crosslinked film by a conventional method is insufficient in the durability of lubricity, and for example, if an operation such as insertion is repeated, the lubricity may be lost.
This durability problem is considered to be due to abrasion or peeling due to friction during insertion due to insufficient strength of the hydrophilic resin film or the crosslinked film. Therefore, it is conceivable to improve the strength by increasing the crosslinking density of the crosslinked film. However, if the crosslink density of the film is increased to such an extent that sufficient strength can be obtained, the hydrophilicity is lowered and lubricity cannot be obtained. Therefore, it is difficult to improve the durability of the lubricity while maintaining good lubricity.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a laminate having high surface lubricity and excellent durability of the lubrication and a medical device including the laminate. To do.

The present invention for solving the above problems has the following aspects.
[1] A laminate comprising a substrate and a lubricating layer covering the surface of the substrate,
The said lubricating layer contains a cellulose fiber and hydrophilic resin, The laminated body characterized by the above-mentioned.
[2] The laminate according to [1], wherein the cellulose fiber is a cellulose nanofiber.
[3] The laminate according to [1] or [2], wherein a hydroxyl group of the cellulose fiber is modified.
[4] The laminate according to any one of [1] to [3], in which the cellulose fiber and the hydrophilic resin are chemically bonded.
[5] The laminate according to any one of [1] to [4], wherein the hydrophilic resin is at least one selected from the group consisting of a polymer having an acid anhydride group and a hydrolyzate thereof.
[6] A medical instrument comprising the laminate according to any one of [1] to [5].

  ADVANTAGE OF THE INVENTION According to this invention, the surface lubricity is high and can provide the laminated body which was excellent also in durability of this lubricity, and a medical device provided with this laminated body.

It is a figure explaining the evaluation method used in the Example.

The laminate of the present invention is a laminate comprising a base material and a lubricating layer that covers the surface of the base material, wherein the lubricating layer contains cellulose fibers and a hydrophilic resin. .
In the laminate of the present invention, since the lubricating layer contains a hydrophilic resin, when it comes into contact with water-containing liquids such as water, body fluids, physiological saline, and buffer solutions, it absorbs and retains water to provide lubricity. Is expressed. In addition, the cellulose fibers are dispersed in the hydrophilic resin to exhibit an excellent reinforcing effect, and the strength of the lubricating layer is improved. For this reason, a decrease in the thickness of the lubrication layer due to friction or the like is suppressed, and an excellent lubrication effect is exhibited over a long period of time.
Hereinafter, the laminate of the present invention will be described in more detail.

[Lubrication layer]
(Cellulose fiber)
Cellulose fiber is fibrous cellulose, and is excellent in reinforcing effect on hydrophilic resin as compared with, for example, granular cellulose.
It does not specifically limit as a cellulose fiber, The thing manufactured by the commercially available thing and the well-known manufacturing method can be used.
Cellulose fibers preferably have an average diameter of 5 μm or less because the smaller the average diameter, the greater the surface area and the reinforcing effect on the hydrophilic resin. Among these, cellulose nanofibers having an average diameter of less than 1 μm are preferable. Cellulose nanofibers are uniformly dispersed at the nanometer level in the lubricating layer and exhibit an excellent reinforcing effect.

The cellulose nanofibers preferably have an average degree of polymerization of 600 or more and 30000 or less, more preferably 600 or more and 5000 or less, and still more preferably 800 or more and 5000 or less.
If the average degree of polymerization is 600 or more and 30000 or less, a sufficient reinforcing effect can be obtained.

The cellulose nanofibers preferably have an aspect ratio of 20 to 10,000, and more preferably 20 to 2,000.
If the aspect ratio is 20 or more and 10,000 or less, an excellent reinforcing effect can be obtained.
In the present specification, the “aspect ratio” means a ratio of average fiber length to average diameter (average fiber length / average diameter). The average diameter and average fiber length of the cellulose nanofiber can be measured by a scanning electron microscope (SEM).

The cellulose nanofibers preferably have an average diameter of 1 to 800 nm, more preferably 1 to 300 nm, and even more preferably 1 to 100 nm.
When the average diameter is 1 nm or more, the production cost does not increase. When the average diameter is 800 nm or less, the aspect ratio is difficult to decrease. Therefore, a sufficient reinforcing effect can be obtained at a low cost.

The cellulose fiber preferably has an Iβ type crystal peak in the X-ray diffraction pattern.
Cellulose type I obtained from natural plant cell walls is a composite crystal of Iα type crystal and Iβ type crystal, and higher plant-derived cellulose such as wood and cotton has many Iβ type crystal components, but in the case of bacterial cellulose, Iα type There are many crystal components.
A cellulose fiber having an Iβ type crystal peak has a higher crystallinity and an excellent reinforcing effect than a cellulose fiber having no Iβ type crystal peak, for example, a cellulose fiber having an Iα type crystal peak.
The cellulose fiber having an Iβ type crystal peak preferably has only an Iβ type crystal peak. That is, an X-ray diffraction pattern having a θ range of 0 to 30 has one or two peaks at 14 ≦ θ ≦ 18, one peak at 20 ≦ θ ≦ 24, and other peaks. It is preferable not to have.
The X-ray diffraction pattern of the cellulose fiber can be analyzed using, for example, a powder X-ray diffraction apparatus Rigaku Ultimate IV (manufactured by Rigaku Corporation).

  The cellulose fiber is preferably obtained using an ionic liquid. The cellulose fiber manufacturing method will be described in detail later, but when the cellulose-containing raw material is subjected to defibrating treatment or the like to produce cellulose fiber, the ionic liquid is used to perform the defibrating process only by mechanical shearing. Compared to the above, it is difficult to damage the cellulose fiber. Therefore, the average degree of polymerization, the aspect ratio, the degree of crystallization, and the like are hardly reduced by the defibrating process, and for example, cellulose nanofibers having an average degree of polymerization of 600 or more can be easily obtained. Therefore, the obtained cellulose fiber is excellent in the reinforcing effect.

The cellulose fiber is preferably modified with a hydroxyl group (a hydrogen atom of the hydroxyl group is substituted with a modifying group). The cellulose fiber modified with a hydroxyl group has a reduced number of hydroxyl groups present on the surface of the cellulose fiber as compared with an unmodified cellulose fiber, and thus strong adhesion due to hydrogen bonding between the cellulose fibers is suppressed. Therefore, the uniformity of the dispersion of the cellulose fibers in the hydrophilic resin is improved, and an excellent reinforcing effect is exhibited. Moreover, the heat resistance is also excellent, and the heat resistance of the lubricating layer containing it is also improved.
The modification rate of the cellulose fiber, that is, the ratio of the modified hydroxyl group in the total hydroxyl group in the cellulose fiber (the total of the modified hydroxyl group and the unmodified hydroxyl group) is 0.01 to 50%. It is preferable that it is 10 to 20%.

The modification of the hydroxyl group of cellulose fiber can be carried out by reacting a modifying agent with cellulose fiber. The modifying agent is not particularly limited as long as it can react with a hydroxyl group, and can be appropriately selected from the modifying agents proposed so far. From the viewpoint of simplicity and efficiency, the modifying agent is preferably an etherifying agent or an esterifying agent.
Examples of the etherifying agent include alkyl etherifying agents, silyl etherifying agents, and aromatic ring-containing etherifying agents.
As the alkyl etherifying agent, alkyl halides such as methyl chloride and ethyl chloride; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; dialkyl sulfates such as dimethyl sulfate and diethyl sulfate; alkylene oxides such as ethylene oxide and propylene oxide are preferable. .
Examples of silyl etherifying agents include n-butoxytrimethylsilane, tert-butoxytrimethylsilane, sec-butoxytrimethylsilane, isobutoxytrimethylsilane, ethoxytriethylsilane, octyldimethylethoxysilane, cyclohexyloxytrimethylsilane, and other alkoxysilanes; Alkoxysiloxanes such as dimethylsiloxane; disilazanes such as hexamethyldisilazane, tetramethyldisilazane, diphenyltetramethyldisilazane; silyl halides such as trimethylsilyl chloride and diphenylbutyl chloride; silyl trifluoromethanes such as tert-butyldimethylsilyl trifluoromethanesulfonate Sulfonate; and the like.
Among the above, the silyl etherifying agent is preferably an alkylsilyl etherifying agent having an alkyl group bonded to a silicon atom.
Examples of the aromatic ring-containing etherifying agent include benzyl bromide.
Examples of esterifying agents include carboxylic acids, carboxylic anhydrides, and carboxylic acid halides that may contain heteroatoms, and more specifically, acetic acid, propionic acid, butyric acid, acrylic acid, methacrylic acid, and these. And the like.
As the esterifying agent, an alkyl esterifying agent is preferable, and acetic acid, acetic anhydride, and butyric anhydride are more preferable.
Among the above modifiers, an alkyl etherifying agent, an alkylsilyl etherifying agent, and an alkyl esterifying agent are preferable because of the excellent dispersibility improvement effect. According to the alkyl etherifying agent, an alkyl group is introduced as a modifying group. According to the silyl etherifying agent, a silyl group is introduced as a modifying group. According to the alkyl esterifying agent, an alkylcarbonyl group is introduced as a modifying group. These are common in that they have an alkyl group.

As a cellulose fiber, 1 type may be used independently and 2 or more types from which a crystallinity degree, a crystal structure, the kind of modification group, a modification rate, etc. differ may be used together.
The content of the cellulose fiber in the lubricating layer is preferably 5 to 80% by mass, more preferably 5 to 50% by mass, and still more preferably 5 to 30% by mass with respect to the total mass of the lubricating layer. When the content of the cellulose fiber in the lubricating layer is 5% by mass or more, the reinforcing effect is sufficiently obtained, and the effect of improving the durability of lubricity is sufficiently obtained. If it exceeds 80% by mass, the lubricity may be impaired.

(Hydrophilic resin)
The hydrophilic resin is a component that constitutes a lubricating layer and that absorbs and retains water and exhibits lubricity when the lubricating layer comes into contact with a water-containing liquid such as water, body fluid, physiological saline, or buffer solution. .
The hydrophilic resin is not particularly limited as long as it has the above-mentioned performance, and has been appropriately selected from those that have been proposed as hydrophilic resins that can be used for the purpose of imparting lubricity to the surface of medical devices and the like. You can choose. Examples of the hydrophilic resin include a polymer having an acid anhydride group and a hydrolyzate thereof, a crosslinked product of the hydrolyzate, a polymer having a hydroxyl group and a crosslinked product thereof, a polymer having an amino group and a crosslinked product thereof. Can be mentioned.

The polymer having an acid anhydride group is a polymer (homopolymer or copolymer) containing at least two monomer units having an acid anhydride group in one molecule. For example, maleic anhydride-ethylene Copolymers, maleic anhydride polymers such as maleic anhydride-styrene copolymers, maleic anhydride-methyl vinyl ether copolymers, and acrylic anhydride polymers such as polyacrylic anhydride, acrylic anhydride-styrene copolymers And methacrylic anhydride-based polymers such as polymethacrylic anhydride and methacrylic anhydride-styrene copolymer.
The hydrolyzate of a polymer having an acid anhydride group is obtained by hydrolyzing the acid anhydride group of a polymer having an acid anhydride group to form a carboxy group.
Examples of the crosslinked product of the hydrolyzate include those obtained by crosslinking the hydrolyzate with a compound having two or more reactive functional groups that react with a carboxy group. Examples of the reactive functional group that reacts with a carboxy group include a hydroxy group, an amino group, and an isocyanate group.

Examples of the polymer having a hydroxyl group include cellulose polymers such as 2-hydroxyethyl methacrylate and hydroxypropyl cellulose, and polyol polymers such as propylene diol, ethylene glycol, propylene glycol, polyethylene glycol, and polypropylene glycol.
Examples of the crosslinked product of a polymer having a hydroxyl group include those crosslinked with a compound having two or more reactive functional groups that react with a hydroxyl group. Examples of the reactive functional group that reacts with a hydroxyl group include a carboxyl group, an amino group, and an isocyanate group.

  For example, specific examples of compounds having two or more amino groups as reactive functional groups include diamines such as ethylene diamine, propylene diamine, hexamethylene diamine, polyethylene glycol diamine, and polypropylene glycol diamine, urea, polyvinyl amine, and amino acetalized polyvinyl alcohol. And substances having an amino group such as polyethyleneimine, a reaction product of diamine and epichlorohydrin, and polyvinylpyrrolidone polymers such as polyvinylpyrrolidone and polyvinylpolypyrrolidone.

Examples of the polymer having an amino group include polyvinylpyrrolidone polymers such as polyvinylpyrrolidone and polyvinylpolypyrrolidone.
Examples of the crosslinked product of the polymer having an amino group include those crosslinked with a compound having two or more reactive functional groups that react with the amino group. Examples of the reactive functional group that reacts with an amino group include a carboxyl group, a hydroxyl group, and an isocyanate group.

The weight average molecular weight of the hydrophilic resin is preferably in the range of 5 to 5 million.
A hydrophilic resin may be used individually by 1 type, or may use 2 or more types together.

Among the above, the hydrophilic resin is preferably at least one selected from the group consisting of a polymer having an acid anhydride group and a hydrolyzate thereof, and is selected from the group consisting of a maleic anhydride polymer and a hydrolyzate thereof. At least one is more preferable.
By using these polymers as the hydrophilic resin, the lubricity is high, and the effect of improving the durability of the lubricity is particularly excellent.
Furthermore, the hydrolyzate of a polymer having an acid anhydride group can be easily chemically bonded to the cellulose nanofiber. For example, when cellulose nanofibers are blended in the hydrolyzate solution, coated on a substrate and heated, the carboxy group of the hydrolyzate reacts with the hydroxyl groups of cellulose nanofibers to form a covalent bond (ester bond). It is formed.

When the hydrophilic resin and the cellulose nanofiber are chemically bonded, the reinforcing effect of the cellulose nanofiber is improved, the strength of the lubricating layer is increased, and the durability of the lubrication is further improved compared to the case where the hydrophilic resin and the cellulose nanofiber are not chemically bonded. improves.
The chemical bond is not limited to a covalent bond and may be a hydrogen bond or the like, but a covalent bond is preferable. Since the hydrophilic resin and the cellulose nanofiber are covalently bonded to form a composite, the reinforcing effect is particularly excellent.
A covalent bond is not limited to the ester bond formed by reaction with the carboxy group of the hydrolyzate of the polymer which has an acid anhydride group, and the hydroxyl group of a cellulose nanofiber. For example, the hydrophilic resin may have a functional group other than a carboxy group (for example, an isocyanate group) as a reactive functional group that reacts with a hydroxyl group. Moreover, the compound which has a functional group (for example, a hydroxyl group, an amino group, etc.) which reacts with the functional group which hydrophilic resin has, and a functional group (for example, a carboxy group, an isocyanate group etc.) which reacts with the hydroxyl group which a cellulose nanofiber has. It may be used to crosslink the hydrophilic resin and the cellulose nanofiber.
In terms of reinforcement, the hydrophilic resin has a reactive functional group (carboxy group, isocyanate group, etc.) that reacts with a hydroxyl group, and the reactive functional group reacts with the hydroxyl group of the cellulose fiber to form a covalent bond. Is preferably formed.

(Optional component)
The lubricating layer may contain components other than the cellulose fiber and the hydrophilic resin as long as the effects of the present invention are not impaired.
As this other component, the dispersing agent etc. which improve the dispersibility of a cellulose fiber are mentioned, for example.

  In the laminate of the present invention, the lubricating layer may partially cover the surface of the substrate, or may cover the entire surface.

[Base material]
The material and shape of the substrate can be appropriately set according to the use of the laminate, and are not particularly limited.
Although it does not specifically limit as a material of a base material, For example, resin, such as a polyamide resin, a polyurethane resin, polyolefin resin, a silicone resin; Ceramics, such as glass; Metals, such as stainless steel and titanium;
1 type or 2 types or more may be sufficient as the material which comprises a base material. For example, the base material may be composed of a plurality of members made of different materials.

The laminate of the present invention is useful as a medical instrument, particularly a medical instrument having an insertion portion that is inserted into the body (for example, the trachea, digestive tract, urethra, other body cavities and tissues), and as a member of a medical instrument. . The medical device provided with the laminate of the present invention exhibits excellent lubricity due to the surface of the laminate being in contact with body fluids, etc., and is less likely to cause wear or loss of the lubrication layer due to friction, sliding, etc. Excellent durability.
Therefore, as the base material, such a medical instrument and a member constituting the medical instrument (hereinafter referred to as a medical instrument member) are suitable. By using these as a base material, a medical device with a lubricating layer can be obtained.
Specific examples of the medical instrument include a medical tube, a guide wire, a catheter, and an endoscope. The member for the medical device is preferably a member constituting the insertion portion, and specific examples include a guide wire hull, a catheter hull, an endoscope hull, an endoscope photographing lens, and the like.
In particular, in the case of an imaging lens for an endoscope, by providing a lubricating layer, lubricity is imparted and sliding upon insertion is improved, and an antifogging effect and an antifouling effect are also obtained.
In terms of anti-fogging and anti-fouling effects, members made of transparent materials such as lenses and window glass used in various fields other than medical instruments such as endoscope imaging lenses, and articles provided with the same Is also useful as a substrate in the present invention.

The base material may be subjected to a surface treatment for improving adhesion to the lubricating layer on the surface to be coated with the lubricating layer. Examples of the surface treatment include atmospheric pressure plasma treatment, corona discharge treatment, ultraviolet irradiation treatment, excimer laser treatment, electron beam irradiation treatment, solution treatment with a primer, and the like.
In addition, the base material may be provided with an intermediate layer on the surface covered with the lubricating layer.

<Method for producing laminate>
As a method for producing the laminate of the present invention, for example, a lubricating layer forming coating solution containing a hydrophilic resin, cellulose fiber and a solvent is applied to the surface of a substrate to form a coating film, The method including the process of drying a coating film is mentioned.

The lubricating layer forming coating solution can be prepared by mixing a hydrophilic resin, cellulose fiber, and a solvent. You may add an arbitrary component as needed.
The solvent is not particularly limited as long as it can dissolve the hydrophilic resin. Examples thereof include ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, alcohol solvents such as methanol, ethanol, isopropanol, and butanol, butyl acetate, and ethyl acetate. And ester solvents such as tetrahydrofuran, ether solvents such as tetrahydrofuran, and hydrocarbon solvents such as cyclohexane, toluene, and xylene.
0.1-50 mass% is preferable and, as for the solid content density | concentration of the coating liquid for lubrication layer formation, 0.5-30 mass% is more preferable. If the solid content concentration is 0.1% by mass or more, a sufficient dry coating amount can be secured by one application, and if it is 50% by mass or less, coating can be easily performed. Solid content concentration is calculated | required from the compounding quantity of each component.

When forming a lubricating layer in which a hydrophilic resin and cellulose fiber are chemically bonded, a reactive functional group (carboxy group, isocyanate group, etc.) that reacts with a hydroxyl group as a hydrophilic resin in the lubricating layer forming coating solution. It is preferable to include a hydrophilic resin having a ratio and to dry the coated film by heating. Thereby, the reactive functional group and the hydroxyl group of the cellulose fiber react to form a covalent bond.
The hydrophilic resin having a reactive functional group that reacts with a hydroxyl group is preferably a hydrolyzate of a polymer having an acid anhydride group.

A hydrolyzate of a polymer having an acid anhydride group can be prepared by adding warm water to a solution of a polymer having an acid anhydride group. By adding warm water, the acid anhydride group of the polymer having an acid anhydride group is hydrolyzed to form a carboxy group.
The temperature of the hot water is preferably 40 to 90 ° C. When the temperature of the hot water is less than 40 ° C., hydrolysis is difficult, and when the temperature exceeds 90 ° C., the water easily evaporates, making handling difficult.
0.1-50 mass% of content of the polymer which has an acid anhydride group is preferable, and, as for the addition amount of warm water, 0.1-10 mass% is more preferable. When the content is 0.1% by mass or more, the acid anhydride group can be sufficiently hydrolyzed to form a carboxy group. If the amount exceeds 10% by mass, the amount of hot water that does not contribute to hydrolysis of the acid anhydride group increases, the solid content concentration of the coating liquid for forming the lubricating layer decreases, and a sufficient dry coating amount is ensured by a single application. There is a risk that it will not be possible.
The cellulose fiber may be added in advance before adding warm water to the polymer solution having an acid anhydride group (before hydrolysis) or after hydrolysis. In view of dispersibility of the cellulose fiber, it is preferably added before hydrolysis.
The solution containing the hydrolyzate of a polymer having an acid anhydride group and cellulose fibers thus obtained can be used as a lubricating layer forming coating solution as it is. When the solution is applied to the substrate surface and dried by heating, a lubricating layer containing a composite in which the carboxy group of the hydrolyzate and the hydroxyl group of the cellulose fiber are ester-bonded is formed.

The method for applying the lubricating layer forming coating solution is not particularly limited, and a known coating method can be used. Examples thereof include a dip coating method, a spray coating method, a curtain coating method, and a blade coating method.
The coating amount of the lubricating layer forming coating solution is set according to the thickness of the lubricating layer.
Examples of the method for drying the coating film include drying with hot air, drying by infrared irradiation, and vacuum drying.
When the coating film is dried by heating, the heating temperature is preferably room temperature or higher, and more preferably 50 ° C. or higher. If it is 50 degreeC or more, drying efficiency is favorable. Further, when a hydrophilic resin and cellulose fiber are chemically bonded, a chemical bond is easily formed.
The upper limit of heating temperature should just be the temperature which a base material does not deform | transform, and 150 degrees C or less is preferable.
The heating time only needs to be within a range in which drying and chemical bond formation are sufficiently completed, and can be appropriately set in consideration of the heating temperature and the like. Usually, it is about 5 minutes to 48 hours.

The dried coating film may be used as a wet layer as it is, or may be further treated by bringing it into contact with water and drying to form a wet layer. By performing such treatment, water can be absorbed and retained in a shorter time when contacted with water, body fluid, physiological saline, buffered water, etc., and lubricity can be expressed in a shorter time. Can do.
Examples of the method of bringing water into contact include a method of immersing in warm water and a method of bringing into contact with water vapor.
The temperature of water (hot water, water vapor, etc.) to be contacted is preferably 40 to 90 ° C. The contact time with water is not particularly limited, but is preferably about 5 minutes to 48 hours.

<Application>
As described above, the laminate of the present invention is useful for medical instruments, and in particular, for medical instruments having an insertion portion that is inserted into the body (for example, the trachea, digestive tract, urethra, other body cavities and tissues). Useful as. As a medical instrument, a medical tube, a guide wire, a catheter, and an endoscope are particularly suitable.
In addition, when a lubricating layer is provided on the surface of the transparent material, an antifogging effect and an antifouling effect are also obtained, and therefore applications for which these effects are required, such as lenses, window glass, mirrors, glasses, articles provided with these, etc. It is also useful in other applications.

<Method for producing cellulose fiber>
Cellulose fibers can be produced by known methods. For example, it can be produced by subjecting a cellulose-containing raw material to a defibrating treatment such as mechanical shearing and chemical treatment, and modification as necessary.
Although it does not specifically limit as a cellulose-containing raw material, Natural cellulose raw materials, such as linter, cotton, and linen; Wood chemical processing pulps, such as a kraft pulp and a sulfite pulp; Semichemical pulp; Waste paper or its regenerated pulp etc. are mentioned. In view of cost, quality, and environment, wood chemically treated pulp and wood chemically treated pulp are preferable, and linters having a high average degree of polymerization are more preferable. The shape of the cellulose-containing raw material is not particularly limited, but it is preferable to use the cellulose-containing raw material after being appropriately pulverized from the viewpoint of easy mechanical shearing and promoting penetration of the solvent in chemical treatment.
For the defibrating treatment, either mechanical shearing or chemical treatment can be used. Examples of the chemical treatment include an N-methylmorpholine-N-oxide (NMMO) method, a copper ammonia solution method, an ionic liquid method, and the like.

As a method for producing cellulose fiber, a method using an ionic liquid is preferable. According to this method, it is possible to produce a cellulose nanofiber having a high crystallinity and a large aspect ratio. Such cellulose nanofibers have a high reinforcing effect and an excellent effect of improving the strength of the lubricating layer. For example, a cellulose fiber having a large aspect ratio provides a mechanical layer with excellent mechanical strength because the entanglement between molecules and the network structure are strengthened.
The manufacturing method of the cellulose fiber using an ionic liquid includes the process of fibrillating a cellulose-containing raw material in the solution (henceforth a process liquid) containing an ionic liquid.
Specifically, when the cellulose-containing raw material is added to the treatment liquid and stirred, the cellulose-containing raw material swells and dissolves to obtain cellulose fibers. By adjusting the type and concentration of the ionic liquid in the treatment liquid at this time, the stirring conditions, the treatment time, etc., the degree of defibration, crystallinity, etc. of the cellulose fiber can be adjusted. The higher the degree of defibration, the smaller the diameter of the cellulose fiber contained in the treatment liquid.

  Examples of the ionic liquid used for the treatment liquid include those represented by the following general formula (I).

［式中、Ｒ^１は炭素数１〜４のアルキル基であり、Ｒ^２は炭素数１〜４のアルキル基またはアリル基であり、Ｘはハロゲン、擬ハロゲン、炭素数１〜４のカルボキシレート、またはチオシアネートである。］

[Wherein, R ¹ represents an alkyl group having 1 to 4 carbon atoms, R ² represents an alkyl group having 1 to 4 carbon atoms or an allyl group, and X represents halogen, pseudohalogen, or a carboxylate having 1 to 4 carbon atoms. Or thiocyanate. ]

  Examples of the ionic liquid represented by the formula (I) include 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium bromide, 1-allyl-3-methylimidazolium chloride, bromide. Examples include 1-allyl-3-methylimidazolium and 1-propyl-3-methylimidazolium bromide.

The cellulose-containing raw material can be defibrated with only the ionic liquid, but if the dissolving power is too high and the fine fibers may be dissolved, a solution containing the ionic liquid and the organic solvent is used as the treatment liquid. It is preferable to use it.
The organic solvent to be added to the ionic liquid may be appropriately selected in consideration of compatibility with the ionic liquid, affinity with cellulose, solubility of the cellulose fiber after mixing with the ionic liquid, viscosity, and the like. At least one selected from -dimethylacetamide, N, N-dimethylformamide, 1-methyl-2-pyrrolidone, dimethyl sulfoxide, acetonitrile, methanol, and ethanol is preferable. The coexistence of these organic solvents promotes the penetration of the ionic liquid between the fine fibers of cellulose. In addition, the destruction of the crystal structure of the fine fiber due to the ionic liquid can be prevented.

  The content of the ionic liquid in the treatment liquid depends on the types of the cellulose-containing raw material, the ionic liquid, and the organic solvent, and may be appropriately adjusted. However, from the viewpoint of swelling and dissolving ability, 20% by mass or more is preferable. In particular, 30% by mass or more is more preferable when an organic solvent having a high dissolving power with respect to the cellulose-containing raw material is used. In the case of using an organic solvent (such as methanol) having a low solubility in the cellulose-containing raw material, 50% by mass or more is more preferable. More preferably, it is 70 mass%.

  The amount of the cellulose-containing raw material added to the treatment liquid is preferably in the range of 0.5 to 30 mass% when the mass of the treatment liquid before addition is 100 mass%. 0.5 mass% or more is preferable from a viewpoint of economical efficiency, and 1 mass% or more is more preferable. From the viewpoint of uniformity of defibration degree, 30% by mass or less is preferable, and 20% by mass is more preferable.

  The treatment temperature of the defibration treatment is not particularly limited, and an appropriate temperature for swelling the cellulose-containing raw material and softening / dissolving the bonded material between the fine fibers may be selected. Good. If it is lower than 20 ° C., the fibrillation effect may be lowered due to the low processing speed and the high viscosity of the processing liquid. Therefore, a separate defibrating process is required. If the temperature exceeds 120 ° C., the nanofibers are dissolved, and the nanofibers may be damaged, and the yield of the nanofibers may be lowered.

In the treatment liquid, the cellulose fiber may be modified in parallel with or after the defibrating treatment.
The modification of the cellulose fiber can be carried out by adding a modifier to the treatment liquid containing the cellulose fiber and reacting it.
As described above, the modifying agent is preferably an etherifying agent or an esterifying agent.
The usage-amount of a modifier is set according to the desired modification rate of a cellulose fiber.
The reaction conditions between the cellulose fiber and the modifier are not particularly limited, and may be the same as the treatment temperature for the defibrating treatment.
The cellulose fiber in the treatment liquid can be recovered by filtering the treatment liquid after the fibrillation treatment and the optional modification as described above.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example.
The cellulose fibers used in the examples are shown below.
CF1: Cellulose fiber obtained by drying Nata de Coco (manufactured by Fujicco Co., Ltd., average polymerization degree: 3000 or more, average aspect ratio: 1000 or more, average diameter: about 5 μm).
CF2: Cellulose nanofibers produced in Production Example 1 below (unmodified).
CF3: Cellulose nanofiber produced in Production Example 2 below (modification rate: 15%).
As maleic anhydride-methyl vinyl ether copolymer (VEMA), Gantrez AN169 manufactured by ISP was used.

[Production Example 1. Production of CF2]
2 g of filter paper cut into 3 mm squares with scissors is placed in a 200 mL flask, and 50 mL of N, N-dimethylacetamide and 60 g of 1-butyl-3-methylimidazolium chloride (ionic liquid) are added and stirred. Defibration treatment was performed. Thereafter, the treatment liquid in the flask was filtered to recover cellulose nanofibers (CF2). The obtained CF2 had an average diameter of 100 nm, an aspect ratio of 100, and an average degree of polymerization of 800.

[Production Example 2. Production of CF-3]
After performing the defibrating treatment in the same manner as in Example 1, acetic anhydride was added as an esterifying agent to the treatment liquid in the flask for acetylation. The obtained treatment liquid was filtered to recover cellulose nanofibers (CF3). The obtained CF3 had an average diameter of 100 nm, an aspect ratio of 100, an average degree of polymerization of 800, and a modification rate of 15%.

The average diameter, aspect ratio, average polymerization degree of CF-2 and CF-3, and the modification rate of CF3 were measured by the following procedure.
(Measuring method of average diameter and aspect ratio)
A dispersion liquid in which cellulose nanofibers are dispersed is cast on a substrate and observed with an SEM, and the diameter and length values of 20 or more fibers obtained per image are read, and this is overlapped by at least 3 sheets. An image of the unexposed area was performed to obtain information on the diameter and length of at least 30 fibers. The average diameter was calculated from the obtained diameter data. Further, the average fiber length was calculated from the obtained length data, and the aspect ratio was calculated from these results.
(Average polymerization degree)
The average degree of polymerization of sesulose fiber was calculated by the copper ethylenediamine method described in “Polymer Material Test Method 2” P276, edited by Kyoritsu Shuppan (1965).
(Method of measuring the modification rate)
It calculated from the element ratio of carbon, hydrogen, and oxygen obtained by elemental analysis.

<Examples 1-3>
In a solution obtained by dissolving maleic anhydride-methyl vinyl ether copolymer (VEMA) in acetone so as to have a concentration of 1% by mass, 5% by mass of CF1 (Example 1) and CF2 ( Example 2) or CF3 (Example 3) was added and mixed to prepare a lubricating layer forming coating solution. The lubricating layer forming coating solution was applied to the surface of a nylon substrate and dried at 90 ° C. for 3 hours. After drying, the formed film was immersed in warm water at 60 ° C. for 30 minutes and dried at 60 ° C. for 24 hours to obtain a laminate in which a lubricating layer was laminated on the substrate surface.

<Example 4>
To a solution in which VEMA was dissolved in acetone to a concentration of 1% by mass, 5% by mass of CF 2 was added to VEMA (100% by mass) and mixed. Further, 60 ° C. warm water was added to and mixed with the obtained mixture so that VEMA: CF 2: warm water = 20: 1: 10 (mass ratio) to prepare a lubricating layer forming coating solution. The lubricating layer forming coating solution was applied to the surface of a nylon substrate and dried at 90 ° C. for 3 hours. After drying, the formed film was immersed in warm water at 60 ° C. for 30 minutes and dried at 60 ° C. for 24 hours to obtain a laminate in which a lubricating layer was laminated on the substrate surface.

<Comparative Example 1>
After immersing the surface of the nylon base material in a solution prepared by dissolving VEMA in acetone to a concentration of 5% by mass and polyethylene glycol (PEG) to a concentration of 0.06% by mass for 1 hour, the surface is taken out and at 90 ° C. for 3 hours. And dried under reduced pressure. After drying, the formed film was immersed in warm water at 60 ° C. for 30 minutes and dried at 60 ° C. for 24 hours to obtain a laminate in which a lubricating layer was laminated on the substrate surface.

<Examples 5 to 8, Comparative Example 2>
A laminate was obtained in the same manner as in Examples 1 to 3 and Comparative Example 1 except that the base material was changed from a nylon base material to a polyurethane base material.

<Examples 9 to 12, Comparative Example 3>
A laminate was obtained in the same manner as in Examples 1 to 3 and Comparative Example 1 except that the base material was changed from a nylon base material to a glass base material.

About the obtained laminated body, the lubricity of the surface which provided the lubricating layer, hydrophilicity, and those durability were evaluated in the following procedures. The results are shown in Tables 1-3.
[Evaluation method]
The evaluation method will be described with reference to FIG. FIG. 1 shows a friction coefficient measuring instrument (manufactured by Shinto Kagaku Co., HEIDON), which includes a measurement sample 5, a mating member 6, a weight 7, a moving table 8, and a weighted converter 9.
The measurement sample 5 is fixed to the moving table 8 and moves in parallel with the moving table 8. The measurement sample 5 placed on the movable table 8 is vertically loaded by the weight 7 and comes into contact with the counterpart member 6. When the movable table 8 is reciprocally translated, friction occurs on the contact surface between the measurement sample 5 and the counterpart member 6. The frictional force at this time is converted into a friction coefficient by the weighting converter 9.

As the measurement sample 5, the laminates of Examples 1 to 12 and Comparative Examples 1 to 3 are arranged so that the surface on the lubricating layer side is in contact with the counterpart member 6, and the friction when the movable table 8 is reciprocated once. The coefficient, the friction coefficient when reciprocating 500 times, and the friction coefficient when reciprocating 1000 times were measured. During the measurement, 5 ml of pure water was added to the measurement sample every 10 reciprocations.
Moreover, when each friction coefficient was measured, the contact angle (°) with respect to the water on the surface on the lubricating layer side was measured by the following procedure.
The friction coefficient is an index indicating surface lubricity, and the smaller the friction coefficient, the better the lubricity.
The contact angle is an index indicating the hydrophilicity of the surface. The smaller the contact angle, the higher the hydrophilicity.

(Measurement method of contact angle)
The contact angle when 1 mL (room temperature) of pure water was dropped on the surface of the measurement sample (contact surface with the mating member 6) after being reciprocated by the friction coefficient measuring device was measured with Dataphysics OCA20.

As shown in the above results, the laminates of Examples 1 to 12 had a friction coefficient of 0.20 or less and a contact angle of 11 or less after 1 reciprocation, 500 reciprocations, and 1000 reciprocations. Both hydrophilicity and durability were excellent.
Among them, Examples 2 to 4, 6 to 8, and 10 to 12 using CF2 and CF3 which are cellulose nanofibers have almost the same coefficient of friction and contact angle after 1000 reciprocations as those after 1 reciprocation. Met. In particular, the results of Examples 3, 7, and 11 using modified CF3 and Examples 4, 8, and 12 in which VEMA was hydrolyzed and reacted (covalently bonded) with CF2 to form a composite were excellent. It was. This is thought to be due to the dispersibility being improved by being a nanofiber, the dispersibility being further improved by being modified, the reinforcing effect being increased by covalent bonding, and the strength of the membrane being further improved. .
On the other hand, in Comparative Examples 1 to 3 using a cross-linked product of VEMA and PEG as the hydrophilic resin, both the friction coefficient and the contact angle greatly increased as the number of reciprocations increased. This is presumably because the strength of the lubricating layer was low, and the frictional layer was worn and peeled off due to friction and lost from the surface of the base material to expose the base material surface.

5 Measurement sample 6 Mating member 7 Weight 8 Moving table 9 Weighted transducer

Claims (6)

A laminate comprising a substrate and a lubricating layer covering the surface of the substrate,
The said lubricating layer contains a cellulose fiber and hydrophilic resin, The laminated body characterized by the above-mentioned.   The laminate according to claim 1, wherein the cellulose fiber is a cellulose nanofiber.   The laminate according to claim 1 or 2, wherein a hydroxyl group of the cellulose fiber is modified.   The laminate according to any one of claims 1 to 3, wherein the cellulose fiber and the hydrophilic resin are chemically bonded.   The laminate according to any one of claims 1 to 4, wherein the hydrophilic resin is at least one selected from the group consisting of a polymer having an acid anhydride group and a hydrolyzate thereof.   A medical instrument provided with the laminated body as described in any one of Claims 1-5.

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