JP7236077B2 - Parts or components for medical equipment - Google Patents

Description

The present invention provides an antibacterial effect or bacterial growth inhibitory effect on the member surface (antibacterial effect or bacterial growth inhibitory effect) by unevenly forming dimple-shaped micro concave portions and ridge-shaped convex portions around the concave portions on the member surface. ), and furthermore, the present invention relates to a medical device part or member (hereinafter also simply referred to as a member) imparted with hydrophilicity (washability) and light reflection suppressing effect.

2. Description of the Related Art Conventionally, stainless steel has been used in parts for medical equipment, such as surgical scalpels, forceps, etc., because it is necessary to prevent them from rusting. However, there is a risk of visibility problems due to improved antibacterial properties, easy staining and difficult removal, and easy reflection of light. One of the reasons for this is that no surface treatment capable of solving the above problems while maintaining antibacterial properties has been found. In addition to antibacterial properties, stainless steel with antifouling, washability, and anti-reflection effects can be applied to applications that strongly require improved workability, especially in hospitals.

In addition to its antibacterial properties, it is also excellent in antifouling properties and hydrophilicity, so it is not only easy to clean, but also has the characteristic of suppressing light reflection on the surface of the member.

The inventors of the present invention have repeatedly conducted various researches and experiments, and based on the results, the applicant of the present application has applied fine particle peening treatment ((WPC treatment) (registered trademark, hereinafter the same)) in Patent Document 1. Accordingly, the inventors have proposed a technique capable of suppressing adhesion of powder by forming a plurality of minute recesses (micro dimples) on the surface of a member that contacts powder (hereinafter also referred to as a powder contact member).

Patent No. 6416151

Here, the applicants of the present application, etc., in order to explore the possibility of applying a surface modification technology to various fields by forming dimple-shaped fine unevenness, have developed a member that contacts a processing target (processing target contact member). Various approaches have been taken to confirm the action and effect of forming countless fine irregularities on the surface in various fields. Obtained.

It should be noted that the effects of forming a plurality (countless) of dimple-like minute recesses have been known to be the effects of suppressing the adhesion of powder and sticky matter, and forming countless minute concaves and convexes on the sliding part. This is the effect of reducing sliding resistance and suppressing wear by functioning as an oil reservoir, and the new effect discovered this time is an unpredictable and completely different effect.

The knowledge is that if dimple-shaped minute recesses and ridge-shaped protrusions around the recesses are unevenly formed on the surface of medical equipment parts, in addition to the antibacterial (or sterilization, sterilization) effect, cleaning This means that it is possible to simultaneously obtain an improvement in properties and an effect of suppressing light reflection.

The present invention has been devised in view of the above-mentioned circumstances, and by unevenly forming dimple-like minute recesses and ridge-like protrusions around the recesses on the surface of the member, the surface of the member is antibacterial (or sterilized). The purpose of the present invention is to provide a medical device part or member which has an effect of sterilization, improvement of washability, and an effect of suppressing light reflection.

The medical device parts or members according to the present invention are
The surface has dimple-like minute recesses, the maximum pitch of which is 7.4 µm or less and the minimum value of which is 0.2 µm or more, and the maximum depth of the recesses related to the pitch is 2 . 0.8 μm or less with a minimum value of 0.03 μm or more, and ridge-shaped projections around the recesses are formed unevenly by projection processing of a shot material, which is a fine particle media , It is characterized by using a functional member whose surface has an antibacterial effect and is hydrophilic .

The medical device parts or members according to the present invention are
The surface has dimple-like minute recesses, the maximum pitch of which is 7.4 µm or less and the minimum value of which is 0.2 µm or more, and the maximum depth of the recesses related to the pitch is 2. 0.8 μm or less with a minimum value of 0.03 μm or more, and ridge-shaped projections around the recesses are formed unevenly by projection processing of a shot material, which is a fine particle media, It is characterized by using a functional member having an antibacterial effect on its surface and a light reflection suppressing effect .

The medical device parts or members according to the present invention are
The surface has dimple-like minute recesses, the maximum pitch of which is 7.4 µm or less and the minimum value of which is 0.2 µm or more, and the maximum depth of the recesses related to the pitch is 2. 0.8 μm or less with a minimum value of 0.03 μm or more, and ridge-shaped projections around the recesses are formed unevenly by projection processing of a shot material, which is a fine particle media, It is characterized by the use of a functional member whose surface has an antibacterial effect and at the same time has hydrophilicity and a light reflection suppressing effect .

The medical device parts or members according to the present invention are
It can be characterized by being used for medical scalpels, scissors, and forceps.

The medical device parts or members according to the present invention are
It can be characterized by being used for medical tweezers.

The medical device parts or members according to the present invention are
It can be characterized by being used for medical bats, universal pots, and pus trays.

The medical device parts or members according to the present invention are
It can be characterized by being used for poles and handrails of medical operating tables or examination tables.

The present invention can be characterized by using stainless steel for the base material.

According to the present invention, by unevenly forming dimple-like minute recesses and ridge-like protrusions around the recesses on the surface of the member, the surface of the member can have an antibacterial (or sterilization or sterilization) effect. It is possible to provide an antibacterial surface treatment method, and parts or members for medical equipment that have an antibacterial (or sterilization or sterilization) effect, an effect of improving washability, and an effect of suppressing light reflection.

On the surface of the member according to one embodiment of the present invention, various substrates are formed by fine particle peening treatment (WPC treatment) to form a non-uniform uneven shape consisting of dimple-shaped minute recesses and ridge-shaped protrusions around the recesses. 1 is a table showing the presence or absence of antibacterial effect, hydrophilicity (low contact angle) corresponding to detergency, and light reflection suppressing effect on each base material untreated member in the material. FIG. 3 is a diagram showing a 3D image and surface roughness of the surface of an untreated test piece (SUS304 stainless steel untreated member); It is a figure which shows the reference example of a 3D image and surface roughness of the surface of the test piece (SUS304 stainless-steel process member) which performed P43 processing. FIG. 3 is a diagram showing a 3D image of the surface of a test piece (SUS304 stainless steel treated member) to which PT1 treatment was applied and a reference example of surface roughness. It is a figure which shows the reference example of the measurement data (surface shape data) of the uneven|corrugated pitch (interval of a convex part) of the test piece which performed P43 process. It is a figure which shows the reference example of the measurement data (surface shape data) of the uneven|corrugated pitch (interval of a convex part) of the test piece which performed PT1 process. FIG. 10 is a cross-sectional SEM image of a single minute concave portion experimentally formed by one-shotting a medium used for fine particle peening according to the embodiment; FIG. It is a recessed part cross-sectional SEM image by laser processing.

An embodiment according to the present invention will be described below with reference to the accompanying drawings. It should be noted that the present invention is not limited by the embodiments described below.

As described above, the applicants of the present application have made contact with the object to be processed in order to explore the possibility of applying the surface modification technology to various fields by forming dimple-shaped microrecesses. Various approaches have been taken to confirm the effects of forming countless micro-recesses on the surface of a member to be treated (contact member to be treated) in various fields. obtained new knowledge that was not previously known.

In the present embodiment, the member is not limited to a member that comes into contact with objects to be processed, including surgical instruments and medical instruments, and is intended for antibacterial purposes (function material).

Specifically, in the process of the above approach, a member (test piece) in which dimple-shaped microrecesses and ridge-shaped protrusions around the recesses were unevenly formed by fine particle peening treatment was subjected to an antibacterial activity evaluation test ( When subjected to Japanese Industrial Standards JIS Z 2801:2010), it was found to have a high antibacterial action (or sterilization action, bactericidal action).
This finding is a hitherto unknown function and effect of a member in which dimple-shaped minute recesses and ridge-line-shaped protrusions are unevenly formed around the recesses on a dimple-shaped surface. From the knowledge, it is an unpredictable effect.

The test was conducted at the Kanagawa Institute of Advanced Industrial Science and Technology, a local independent corporation.
As a test method, samples (test pieces) with different surface treatments (surface textures) were subjected to an antibacterial activity evaluation test by a film adhesion method.

The test conditions are as shown below.
Test strain: Escherichia coli NBRC3972 strain Inoculum concentration: 3.3×10 ⁵ CFU/mL
Inoculum amount of bacterial solution: 0.4 mL
Test area: 40 × 40 mm square Covering film: Esclinica Pack L, manufactured by Sekisui Chemical Co., Ltd. Test temperature: 35 ° C
Test time: 8 hours
A microbial medium sheet for coliform bacteria (manufactured by JNC Co., Ltd.) was used to measure the viable cell count.
The viable cell count was measured by washing the sample with 9.6 mL of sterilized physiological saline and measuring the viable cell count concentration in the washed solution.

The results are shown in FIG. was polished with a No. P400 buff, and its surface had a luster close to a mirror surface, and some streak-like grooves were observed.
Test pieces (2) to (3) to be described later are obtained by subjecting the test piece (1) to various surface treatments.
Here, as an example of the surface of the test piece polished with a P400 buff, FIG. Let me show you.

As shown in Fig. 1, the test piece (2) "SUS420 #400 P43" has sterilized or sterilized E. coli, and has a clear antibacterial action against the test piece (1) of the reference material. there is

The test piece (2) "SUS420 #400 P43" was obtained by subjecting the test piece (1) to a surface treatment (fine particle peening treatment) to form dimple-shaped micro recesses. SiC (carbonized Silicon)) is injected from an injection nozzle together with compressed air of about 1/f (for example, 0.3) MPa, and projection processing (hereinafter also referred to as projection processing) is performed on the surface to be processed (surface of sample, surface of member). .
Next, for example, the second type of media (trade name “Fujirandom (carborundum)”, particle number C # 3000 (maximum particle diameter 13 μm or less, particle diameter at 50% cumulative height 4.0 ± 0.5 μm ) was subjected to projection processing (projection processing) on the surface to be processed together with compressed air of about 1/few (for example, 0.4) MPa.
Here, the fine unevenness forming process (fine particle peening process) in which the above-described media having different specifications are subjected to projection processing in two stages is referred to as P43.

Although the sample (2) (P43 treatment) is a reference example, innumerable dimple-like minute depressions are randomly formed on the surface similarly to the one shown in FIG.

Here, conventionally, in the projection processing for forming dimple-shaped micro recesses by projecting fine particle media (shot material), the pitch of concavities and convexities (adjacent protrusions It was difficult to form a range of about 1.2 to 5.9 μm for the interval) and a range of about 0.1 to 0.7 μm for the depth of the recess), but through experiments and research by the present inventors, By blasting media (shot materials) with different specifications in two stages, it is now possible to form infinitely small dimple-like minute recesses at random even in stainless steel. .

As shown in Fig. 1, the test piece (3) "SUS420 #400 PT1" was sterilized or sterilized with E. coli, and a clear antibacterial effect was obtained compared to the test piece (1) of the reference material. .

The test piece (3) "SUS420 #400 PT1" was obtained by subjecting the test piece (1) to a surface treatment (fine particle peening treatment) to form dimple-shaped microrecesses. Tungsten carbide powder manufactured by Nippon Metal Co., Ltd., symbol WC-10 (particle size: 0.70 to 1.19 μm) is injected from an injection nozzle together with compressed air of about 1/number (for example, 0.4) MPa, Projection processing was performed on the processed surface.
Here, the fine unevenness forming process (fine particle peening process) that performs such projection processing is referred to as PT1.

Although the sample (3) (PT1 treatment) is a reference example, innumerable dimple-like minute recesses are randomly formed on the surface similarly to the one shown in FIG.

Here, conventionally, in the projection processing for forming dimple-shaped micro recesses by projecting a fine particle medium (shot material), the pitch of concavities and convexities (adjacent protrusions interval) was about 0.2 to 0.9 μm, and the depth of the recess was about 0.03 to 0.15 μm). By using a medium (shot material) with a high specific gravity equal to or higher than that of tungsten carbide, it has become possible to randomly form an infinite number of very small dimple-like minute recesses even in stainless steel.

In addition, the range (μm) of the concave and convex pitch (interval between convex portions) of the micro concave portions of the test piece (2) “SUS420 #400 P43” is about 1.2 to 5.9 μm, as shown in FIG. The recess depth range was about 0.1 to 0.7 μm. As a reference example, FIG. 5 shows a reference example of surface shape data obtained by observing the unevenness pitch and depth of minute recesses formed by the P43 treatment.

In addition, the range (μm) of the concave and convex pitch (interval between convex portions) of the micro concave portions of the test piece (3) “SUS420 #400 PT1” is about 0.2 to 0.9 μm, as shown in FIG. The recess depth range was about 0.03 to 0.15 μm. As a reference example, FIG. 6 shows a reference example of surface shape data obtained by observing the unevenness pitch and depth of minute recesses formed by the PT1 treatment.

As can be seen from FIGS. 5 and 6, the uneven surface formed by the fine particle peening treatment is completely different from the geometric and regular uneven shape formed according to a drawing designed in advance by laser processing, etc. It is characterized in that the shape, pitch, and depth of each of the minute concave portions and the ridge-like convex portions around the concave portions are formed unevenly.

By the way, the test pieces (2), (3), etc. have a very remarkable antibacterial, sterilization, and bactericidal effect against E. coli compared to the sample (1), which has grooves (polished grooves) formed on the surface by polishing. There is

Although a detailed analysis is awaited, the dimple-shaped microrecesses formed by the fine particle peening treatment are formed on the surface of a stainless steel member (specimen) such as the test piece (1) by grinding or lapping. Unlike recesses formed by However, one of the reasons is considered to be that adjacent recesses are formed independently and randomly by being partitioned (divided, defined) by the surrounding ridge line protrusions.

That is, according to the data provided by the Tokyo Metropolitan Health and Safety Research Center, the size of E. coli (O157, O111, etc.) is 1.1-1.5 μm (horizontal dimension) x 2.0-6 μm. It is about 0 μm (length), and the E.coli can get stuck in the minute recesses formed by the fine particle peening process or ride on the protrusions, so that the E.coli cannot freely move and move and die. In addition, it can be predicted that the antibacterial effect (action) will occur due to the rotation of the relatively long flagella, which is restricted in movement and movement, self-damage and die. .

The size of Salmonella is 0.7-1.5 μm (horizontal dimension)×2.0-5 μm. It is 0 μm (length), and even for bacteria of such similar size, as with E. coli, a member having countless fine unevenness formed on its surface by the fine particle peening treatment according to the present embodiment is used. is considered to have an antibacterial, sterilizing, or bactericidal effect.

That is, the antibacterial member having countless dimple-shaped microrecesses formed on its surface by the fine particle peening treatment according to the present embodiment is applied to "common bacteria such as Escherichia coli and Salmonella, which are Gram-negative bacteria with flagella." It is considered possible.

Common bacteria also include pertussis, tuberculosis, diphtheria, shigella, and cholera. The size of Bordetella pertussis is small, for example, 0.2 μm × 0.3 to 1.0 μm. The lower limit of the pitch at which the dimple-like minute recesses are formed is considered to be about 0.2 μm (the pitch at which the dimple-like minute recesses are formed may be said to be 0.2 μm or more).

As described above, according to the present embodiment, the surface of the stainless steel member does not have recesses (streaks, grooves) extending in a streak-like manner, but the bottoms of the recesses are formed by the fine particle peening treatment so that the bottoms of the recesses are formed in the surrounding adjacent recesses. By randomly forming a countless number of micro recesses that are defined by the bottom and the ridge line protrusions and are formed independently of each other, antibacterial or sterilization against bacteria such as Escherichia coli, sterilization effect (or bacteria growth inhibitory effect) can be produced.

Subsequently, a flat plate test piece was prepared using a titanium alloy base material used in medical scissors, and various properties under the surface treatment conditions were compared with a base material test piece that had not undergone fine particle peening treatment. evaluated. For the forceps, similarly, the property improvement effect by surface treatment was evaluated.
As a result, as summarized in FIG. 1, various properties such as antibacterial properties, detergency (hydrophilicity), and antireflection effect of light were significantly improved compared to the untreated base material.

That is, according to the present embodiment, by forming a non-uniform concave-convex shape consisting of dimple-like minute concave portions and ridge-like convex portions around the concave portions by fine particle peening treatment (WPC treatment), antibacterial treatment is performed on the surface of the member. (or sterilization, sterilization) effect, and at the same time, it is possible to provide a functional member that can obtain an improvement in washability and an effect of suppressing light reflection.

Here, the fine unevenness forming treatment (fine particle peening treatment (WPC treatment)) according to the present embodiment is performed by injecting the above-described media (shot material, abrasive particles) using a known injection device to contact the object to be processed. It can be performed by colliding with the surface of a member such as a member.

For example, a blasting device can be used as the injection device, and as an example of the blasting device, for example, "PNEUMA BLASTER" (type: SC series, SG series, etc.) manufactured by Fuji Seisakusho Co., Ltd. can be used. can. Further, for example, those described in JP-A-2019-25584 can be used.

More specifically, as an injection device for injecting injection granules toward the surface of a member, a known blast processing device (blast processor) can be used.

The blasting equipment (blasting equipment) is a suction type blasting equipment that injects the abrasive using the negative pressure generated by the injection of compressed gas. Gravity type blasting equipment that sprays on the surface, introduces compressed gas into the tank where the abrasive is put, and adds the abrasive flow from the abrasive tank to the compressed gas flow from the compressed gas supply source that is separately given. Direct-pressure blasting equipment that merges and injects, and blower-type blasting equipment that injects the above-mentioned direct-pressure compressed gas flow on a gas flow generated by a blower unit are commercially available. can be used for jetting the jet granules described above.
A water jet can also be used, which shoots a shot at high pressure along with a liquid such as water.

By the way, in the present embodiment, a countless number of dimple-shaped minute recesses are randomly formed by the fine particle peening process (WPC process), but the present invention is not limited to this, and the contact member to be processed is made of a metal material. In this case, chemical polishing (chemical etching) can be applied to the surface of the member to randomly form a plurality (a large number) of minute recesses. As chemical polishing (chemical etching), for example, it is assumed that acidic chemicals such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, iron chloride (III), etc. are prepared in an aqueous solution at an arbitrary ratio and used. In particular, when the member has a tubular shape (cylindrical shape), it is difficult to form fine irregularities on the inner surface (inner peripheral surface) of the member by the fine particle peening treatment. A chemical etching treatment is effective in imparting the various functions, effects, characteristics, etc. of the present invention to the peripheral surface).

Further, by subjecting the surface of a member such as a contact member to be processed to argon bombardment treatment, it is also possible to randomly form a plurality (a large number) of submicron or less irregularities on the contact surface.

Here, in the present invention, in order to specify the uneven surface formed by fine particle peening from the shape or structure, what is a geometric and regular uneven shape formed according to a drawing designed in advance by laser processing or the like? Completely different, a specific method is used in which dimple-like minute recesses and ridge-like protrusions around the recesses are formed unevenly in shape, pitch, and depth.
In other words, instead of using the specific method (expression) of ``providing an antibacterial effect to the surface by forming microscopic unevenness on the surface by fine particle peening,'' instead of using the specific method (expression), ``dimple-shaped microscopic concaves on the surface and ridge-like convexities around the concaves. It uses a specific method (expression) of "giving the surface an antibacterial effect by forming the part unevenly."
However, in comparison with the prior art, etc., it is assumed that it may be difficult to adopt the above identification method (expression) as a characteristic identification method (expression) that distinguishes the uneven surface formed by fine particle peening from others. be done.

For this reason, it is assumed that the uneven surface formed by fine particle peening must be specified by the specifying method (expression) of "giving the surface an antibacterial effect by forming fine unevenness on the surface by fine particle peening." be done.

Therefore, at the time of filing of the present application, it was impossible or unrealistic to specify the fine unevenness formed by the fine particle peening treatment by the shape, structure, characteristics, etc. It is necessary to use the expression "by forming the" below.

In the fine particle peening process, projecting particles (media) such as glass beads are made to collide with the surface to be processed through compressed air at a speed of several tens to 100 m or more per second. Micro-sized micro-concavities in a substantially spherical shape having a part are irregularly formed on almost the entire surface of the processed surface. , the periphery of which rises to form a protrusion (see FIG. 7), and this raised protrusion is dented by colliding with other media, resulting in an irregular height of the protrusion (see FIG. 3). (See FIG. 6).

On the other hand, mechanical processing such as laser processing and cutting forms regular recesses, and since it is removal processing, no protrusions are formed (the protrusions do not rise with the formation of the recesses). ). Therefore, in mechanical processing such as laser processing and cutting, the height of the protrusions around the minute recesses does not match the height of the surface (original surface of the material) of the material to be processed (the member being laser processed). (See Figure 8).

In addition, since the microscopic unevenness formed by the fine particle peening process is formed irregularly (randomly) innumerably, the surface texture (shape) formed by the fine particle peening process is not affected by polishing or grinding the surface. Although it is different from the surface shape (texture) formed by the process of giving scratches (grooves such as streaks), when measured with a surface roughness meter etc., the values of both are similar numerically. , surface roughness, etc., cannot be distinguished from each other.

However, the effect (antibacterial effect) obtained by the surface texture (shape) formed by the fine particle peening process is not the same as the surface shape (texture) formed by the process of scraping the surface such as polishing or grinding to give scratches. It is completely different and unpredictable.
In addition, it is completely unpredictable that a surface treated with fine particle peening has an antibacterial effect from shot peening, which improves the fatigue limit by imparting residual stress by colliding media of the order of several millimeters.

In this way, the fine unevenness formed by the fine particle peening treatment is innumerably irregularly (randomly) formed, the shapes of the fine concaves and the surrounding convexities are irregular, and the irregularity is determined by the present invention. In view of the fact that it is the source of the effects that are exhibited, the term "formed by fine particle peening" is used as a term for specifying the surface texture (shape) formed by fine particle peening. cannot identify the surface formed by the particulate peening process.
As described above, it is impossible or unrealistic at the time of the filing of the present application to specify the fine unevenness formed by the fine particle peening treatment by the shape, structure, characteristics, and the like.

The present invention is not limited to the embodiments of the invention described above, and various modifications can be made without departing from the gist of the invention.

The present invention provides an antibacterial (or sterilization or sterilization) effect on the surface of a member and improves washability by forming a non-uniform concave and convex shape consisting of dimple-shaped micro concave portions and ridge-like convex portions around the concave portion on the surface of the member. It is useful and usable in the medical industry where improvement of workability as well as sanitation is a problem.

Claims (8)

The surface has dimple-like minute recesses, the maximum pitch of which is 7.4 µm or less and the minimum value of which is 0.2 µm or more, and the maximum depth of the recesses related to the pitch is 2 . 0.8 μm or less with a minimum value of 0.03 μm or more, and ridge-shaped projections around the recesses are formed unevenly by projection processing of a shot material, which is a fine particle media , 1. A part or member for a medical device, characterized by using a functional member whose surface has an antibacterial effect and is hydrophilic . The surface has dimple-like minute recesses, the maximum pitch of which is 7.4 µm or less and the minimum value of which is 0.2 µm or more, and the maximum depth of the recesses related to the pitch is 2. 0.8 μm or less with a minimum value of 0.03 μm or more, and ridge-shaped projections around the recesses are formed unevenly by projection processing of a shot material, which is a fine particle media, 1. A part or member for a medical device, characterized by using a functional member whose surface has an antibacterial action and a light reflection suppressing effect. The surface has dimple-like minute recesses, the maximum pitch of which is 7.4 µm or less and the minimum value of which is 0.2 µm or more, and the maximum depth of the recesses related to the pitch is 2. 0.8 μm or less with a minimum value of 0.03 μm or more, and ridge-shaped projections around the recesses are formed unevenly by projection processing of a shot material, which is a fine particle media, 1. A part or member for a medical device, characterized by using a functional member whose surface is endowed with an antibacterial action and at the same time endowed with a hydrophilic property and a light reflection suppressing effect . 4. The part or member for medical equipment according to any one of claims 1 to 3 , which is used for medical scalpels, scissors, and forceps. 4. The part or member for medical equipment according to any one of claims 1 to 3 , which is used for medical tweezers. 4. The part or member for medical equipment according to any one of claims 1 to 3 , which is used for medical bats, universal jars, and pus basins. 4. The part or member for medical equipment according to any one of claims 1 to 3 , which is used as a pole or handrail for a medical operating table or an examination table. The part or member for medical equipment according to any one of claims 1 to 7 , wherein stainless steel is used for the base material.

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