JP2012210378A - Paint-coated dental metal product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paint-coated dental metal product having excellent aesthetic properties, safety, slipperiness, contamination resistance, bending resistance, and wear resistance in a dental metal product by using the paint-coated dental metal product.SOLUTION: In this paint-coated dental metal product, a paint containing a thermoplastic resin is coated onto the dental metal product.

Description

The present invention relates to a paint-coated dental metal product. More specifically, the present invention relates to a paint-coated dental metal having excellent aesthetics, safety, slipperiness, stain resistance, bending resistance, and wear resistance by applying a paint containing a thermoplastic resin. Regarding products.

In the following, the advantages and problems of metal products in dental applications will be described by taking orthodontic wires and orthodontic brackets as examples.

An orthodontic wire is a device used for orthodontic treatment in combination with an orthodontic bracket. Since high strength and elasticity are required, metal wires are used in almost all clinics.
In recent years, due to the increasing demand for dental aesthetics, attempts have been made to make orthodontic devices that have been metal-colored in the crown color or white, and the bracket is actually made of a crown-colored, white, or transparent ceramic, Alternatively, non-metal aesthetic brackets such as resin products have appeared on the market. However, these aesthetic brackets are inferior in mechanical properties, durability, and toughness compared to metal brackets, so they become thicker and the mounting feeling is inferior compared to metal brackets, or in some cases damaged brackets. There is a problem that the main body must be replaced.
In addition, since orthodontic wires have high demands on strength and elasticity required for materials, there is no material that can replace metal wires, and metal wires that are still inferior in aesthetics continue to be used.
In such a situation, not only the bracket but also the wire has been required to be aesthetic, and an attempt is made to apply a thermosetting paint such as an epoxy resin to a metal wire to bring it close to the crown color or white, or Attempts have been made to make it less noticeable in the oral cavity by gold plating or the like.
However, epoxy resin paints cannot fully satisfy the clinical requirements in terms of slipperiness, bending resistance, wear resistance, adhesion to metal, etc., and gold-plated wires are essentially Has the problem that it cannot be the same color as the teeth.

Patent Document 1 discloses a technique for applying thermoplastic resin particles to metal, but it is exposed to chewing, in some cases, biting, salivation, contact with various foods, low temperature due to food, high temperature, etc. There is no disclosure about adaptation to the oral environment, and metal products to be applied are only described as simple shapes such as flat plates or cylindrical shapes such as beverage cans and batteries, and are thin linear There is no disclosure as to whether or not the present invention can be applied to fine shapes and complex shapes such as orthodontic wires and metal denture bases.
For these reasons, orthodontic wires and orthodontics that have safety, slipperiness, stain resistance, bending resistance, and wear resistance while having aesthetics that are essentially the same color tone as teeth. Brackets are needed.

WO2005 / 019363 pamphlet

  The present invention provides a paint-coated dental metal product having excellent aesthetics, safety, slipperiness, contamination resistance, bending resistance, and abrasion resistance.

The paint-coated dental metal product of the present invention is characterized in that a paint containing a thermoplastic resin is applied to a dental metal product.
In the present invention, a coating-coated dental metal product having excellent aesthetics, safety, slipperiness, stain resistance, bending resistance, and wear resistance is formed by applying a paint containing a thermoplastic resin. can do.

FIG. 1 is a photograph showing an example of an orthodontic appliance coated with the present invention. Since the photo is black and white, the difference is not clear. FIG. 2 is a photograph showing an example of an orthodontic appliance without conventional coating. Since the photo is black and white, the difference is not clear.

Next, the paint-coated dental metal product of the present invention will be specifically described.
The paint-coated dental metal product of the present invention can be obtained by applying a paint containing a thermoplastic resin to a dental metal product.

  The coating thickness of the paint-coated dental metal product coated with the paint containing the thermoplastic resin of the present invention is preferably 35 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less. When the upper limit is exceeded, it is difficult for the finished product to fit within a predetermined dimension. Although it does not specifically limit about a lower limit, Preferably it is 10 nm or more, More preferably, it is 100 nm or more, More preferably, it is 500 nm or more. Below the lower limit, it tends to be difficult to achieve the effect of coating such as hiding the metal color of the base. It should be noted that the paint coating portion where the paint containing the thermoplastic resin of the paint-coated dental metal product is applied only needs to be present at the site where the performance is required. For example, the performance required for the paint coating portion is exclusively used. When it is only necessary to satisfy the aesthetics, there may be no problem as long as only the portion visible from the outside is sufficiently covered when the tooth or the oral cavity is mounted. In other words, a portion that is in close contact with the teeth, gums, bone tissue, and soft tissue and is usually not visible from the outside may have no problem even if the coating film is missing or is not sufficiently thick.

  The paint-coated dental metal product of the present invention usually has a fine or complex shape, and has a non-planar shape and / or a non-cylindrical shape. However, it does not completely exclude a planar shape or a cylindrical shape, and a flat or cylindrical shape is a very small part of the structure of a non-planar shape and / or a paint-coated dental metal product mainly composed of a non-cylindrical shape. There may be a part.

There is no simple flat plate or thick cylindrical shape.
It has a non-planar shape and / or a non-cylindrical shape, specifically, at least one shape selected from the group consisting of a linear shape, a double curved surface shape, a torsional surface shape, a conical surface shape, and a tangential surface shape. . The linear shape is not particularly limited. For example, it may be considered that the diameter is 10 mm or less, but in most of the actual dental metal products, it may be considered that the diameter is 4 mm or less. In the case of the torus shape ((x ² + y ² ) ^1/2 −R) ² + z ² = r ² , r <R), the diameter refers to the diameter (2r) of the small circle, It is not the diameter of the great circle (2R). In addition, since the dental metal product is not limited to a perfect circle, the diameter of the cross-section obtained by converting the non-circular shape into a perfect circle by equal volume conversion may be used. On the other hand, a compound curved surface is a curved surface that does not have a linear element, and if there is a geometric curved surface such as a spherical surface or a torus, it is difficult to express it with a mathematical expression that faithfully reproduces the shape of the tooth surface or oral cavity by impression etc. There are general double curved surfaces or free curved surfaces. A twisted surface is a ruled surface where adjacent linear elements are twisted, a tangential curved surface is a developable surface where adjacent linear elements intersect at different points, and a conical surface is where all adjacent linear elements are in one point. It's a crossable exhibition surface.

In general, it is preferable that an arbitrary point P on the surface of the paint-coated dental metal product has a shape in which the point Q on the surface satisfies the following condition (A).
Condition (A) = Condition (A0) ∩ [Condition (A1) ∪Condition (A2)]
Condition (A0): The linear distance between PQ is 20 mm or less.
Condition (A1): The minimum curvature radius of the surface at the point Q is 5 mm or less.
Condition (A2): The maximum curvature radius of the surface at the point Q is 1000 mm or less.
Furthermore, it is more preferable that the condition (A3) is added and the conditions are as follows.
Condition (A ′) = Condition (A0) ∩ [Condition (A1) ∪ {Condition (A2) ∩Condition (A3)}]
Condition (A3): The radius of curvature between the points PQ is 250 mm or less.
(When the straight line distance between the points PQ is L and the angle between the normals at both points on the curved surface is θ, the radius of curvature between both points is r = L / (2 × sin (θ / 2)). To do.)
In addition, the minimum curvature radius and the maximum curvature radius of the surface at the point Q are as follows. That is, a curve is obtained by cutting a curved surface at an arbitrary plane including the normal of the curved surface at the point of the two-dimensional curved surface existing in the three-dimensional space. That is, if the plane is turned around the normal line, various curves can be obtained as the cross section for the curved surface. Among these curves, the minimum curvature radius at the point is the minimum curvature radius, and the maximum curvature radius is the maximum curvature radius. When the curve is a straight line, the radius of curvature is infinite.

Also, the radius of curvature r between two points PQ on a curved surface, if the straight line distance between points PQ L, the respective angles formed by the normal line n _P and n _Q in both points on the curved surface and the theta, both A radius of curvature r between the points PQ is set to r = L / (2 × sin (θ / 2)). This can be understood as having a graphic relationship with a length L of a straight line passing through both ends of a circular arc with an angle θ of a circle with a radius r.

  The condition (A0) indicates that a simple shape, for example, a flat surface or a cylindrical shape does not continuously exist over a certain range, and the condition (A1) is a cylindrical shape exceeding a radius of 5 mm. It can be understood that the condition (A2) ∩condition (A3) indicates a complex curved surface that is not so gentle.

  The linear distance between PQs in the condition (A0) is more preferably 15 mm or less, and further preferably 10 mm or less. The minimum curvature radius of the surface at the point Q in the condition (A1) is more preferably 2 mm or less, and further preferably 1 mm or less. The maximum curvature radius of the surface at the point Q in the condition (A2) is more preferably 400 mm or less, and further preferably 100 mm or less.

The radius of curvature between the points PQ of the condition (A3) is more preferably 100 mm or less, and further preferably 40 mm or less.
When a metal such as a straightening wire is bent or bent to such an extent that it can be visually recognized by its own weight, the stretched shape may be used as a standard. Particularly in the case of a straightening wire, the diameter is preferably 1 mm or less, more preferably 0.6 mm or less. Therefore, in the case of a straightening wire or the like, the minimum radius of curvature of the surface at the point Q of the condition (A1) is particularly preferably 0.5 mm or less, and very preferably 0.3 mm or less.
When the upper limit value of the conditions (A0) to (A3) is exceeded, the shape of the coated metal dental product is too simple or too large, and it is difficult to obtain a comfortable wearability on the teeth and oral cavity. It becomes.

  Examples of the metal material to be used in the paint-coated dental metal product of the present invention include stainless steel, nickel-titanium alloy, titanium, titanium alloy, cobalt-chromium alloy, nickel-chromium alloy, which are general dental metals. Examples include gold alloys, platinum alloys, gold-silver palladium alloys, and silver alloys, but the present invention is not limited to such examples.

Examples of the thermoplastic resin of the present invention include aromatic polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, polyethylene naphthalate, and polypropylene naphthalate; polylactic acid, polyglycolic acid, polyethylene succinate, polybutylene succinate, Aliphatic polyester resins such as poly (butylene succinate carbonate), poly (butylene succinate adipate), polyhydroxybutyrate, poly (hydroxybutyrate valerate);
Crystalline and non-crystalline fragrances plasticized with crystalline and non-crystalline copolyester resins made from a wide variety of dibasic acids and dihydric alcohols, 1,4 cyclohexanedimethanol or long-chain alkyl diols Group polyester resin;
Polyamide resins such as 6-nylon, 66-nylon, 12-nylon and MXD6-nylon; polycarbonate resins; modified polyolefin resins such as maleated polypropylene and maleated TPX.

Among them, polyethylene terephthalate, polyethylene naphthalate, MXD6-nylon, polybutylene terephthalate, 6 can be selected according to characteristics such as aesthetics, safety, slipperiness, contamination resistance, bending resistance, and abrasion resistance. -Nylon, 66-nylon and polycarbonate are preferred. However, it is not limited to these.
When applying the above thermoplastic resin to dental metal materials

[1] Thermal spray ···········································································································
[2] Aerodeposition method ・ ・ Particles are ejected from nozzles at high speed to form a film on metal.
[3] Powder coating: Uses static electricity to attach powder to metal and heat weld.
[4] Dissolution ··········································································································
[5] Create slurry paint / thermoplastic resin fine particles and apply dispersion / slurry using solvent.
In this example, a slurry paint using extremely fine particles having good film forming property will be described as an example.

That is, a coating for metal coating containing particles of the thermoplastic resin having an average primary particle diameter of 10 to 10,000 nm, obtained by quenching a solution obtained by heating and dissolving a thermoplastic resin in an organic solvent, wherein the thermoplastic resin is It is possible to obtain a paint-coated dental metal product of the present invention by applying a metal coating material that is at least one selected from an aromatic polyester resin, an aliphatic polyester resin, a polyamide resin, a modified polyolefin resin, and a polycarbonate resin. I can do it.
The details will be described below.

  Solvents that dissolve the thermoplastic resin include ester solvents such as ethyl acetate and butyl acetate; dibasic acid ester solvents such as dimethyl adipate, dimethyl glutarate and dimethyl succinate; cyclohexanone, isophorone, methyl isobutyl ketone, etc. Ketone solvents; hydrocarbon solvents such as cyclohexane, toluene and xylene; alcohol solvents such as benzyl alcohol and cyclohexanol; ether solvents such as ethylene glycol monobutyl ether, dipropylene glycol butyl ether and bis (2-methoxyethyl) ether Amide solvents such as formamide, dimethylformamide, dimethylacetamide (DMAc); pyrrolidone solvents such as N-methyl-2-pyrrolidone (NMP); dimethyl sulfoxide, etc. Sulfoxide-based solvents; and mixtures thereof, but not limited thereto. In particular, when the polyester resin is used as the thermoplastic resin, it is possible to repeatedly use the liquid after separating the particles from the obtained suspension as a solvent for further dissolving the thermoplastic resin. When a mixed ester solvent composed of dimethyl acid, dimethyl glutarate and dimethyl succinate, dimethylacetamide, bis (2-methoxyethyl) ether uses a polyamide resin as the thermoplastic resin, formamide, benzyl alcohol, dimethylacetamide, When N-methyl-2-pyrrolidone uses a polycarbonate resin, a mixed ester solvent composed of dimethyl adipate, dimethyl glutarate and dimethyl succinate is preferable.

  It is preferable that the temperature of the solvent at the time of melt | dissolving a thermoplastic resin is 70-200 degreeC. When the thermoplastic resin is polyethylene terephthalate or polybutylene terephthalate, the temperature is more preferably 130 to 190 ° C, and further preferably 140 to 185 ° C. When a thermoplastic resin is polylactic acid, it is more preferable that it is 70-150 degreeC, and it is further more preferable that it is 100-140 degreeC. When a thermoplastic resin is polyglycolic acid, 130-170 degreeC is more preferable and 140-160 degreeC is further more preferable. When the thermoplastic resin is MXD6-nylon, it is more preferably 130 to 180 ° C, and further preferably 140 to 170 ° C. Moreover, when a thermoplastic resin is 6-nylon, it is more preferable that it is 120-180 degreeC, and it is further more preferable that it is 130-170 degreeC. When the thermoplastic resin is 66-nylon, the temperature is more preferably 150 to 190 ° C, and further preferably 170 to 180 ° C. When a thermoplastic resin is 12-nylon, it is more preferable that it is 120-150 degreeC, and it is further more preferable that it is 130-140 degreeC. When the thermoplastic resin is polycarbonate, it is more preferably 130 to 180 ° C, and further preferably 140 to 170 ° C. If the temperature of the solvent is less than 70 ° C., the thermoplastic resin does not dissolve, and therefore there is a tendency that desired particles having an average primary particle diameter of 10 to 10,000 nm cannot be obtained. There is a tendency for the paint to turn yellow and the paint to turn yellow.

   1-20 weight part is preferable with respect to 100 weight part of solvents, and, as for the compounding quantity to the solvent of a thermoplastic resin, 1-10 weight part is more preferable. If the blending amount is less than 1 part by weight, there is a problem in terms of productivity. On the other hand, when the amount exceeds 20 parts by weight, it tends to be difficult to obtain particles having a target average primary particle diameter of 10 to 10,000 nm.

  Examples of the cooling means for the thermoplastic resin solution include a cooling device such as a heat exchanger. The cooling means is preferably used to cool the thermoplastic resin solution at 70 to 200 ° C. to 50 ° C. or lower, more preferably 45 ° C. or lower. When the temperature of the solution after cooling exceeds 50 ° C., the primary particle diameter of the obtained particles tends to increase.

  As a cooling method, a thermoplastic resin solution itself is cooled using a heat exchanger, and a solvent cooled to 20 to -90 ° C using a heat exchanger is mixed with the thermoplastic resin solution. The method of cooling by doing is mentioned. From the viewpoint of cooling efficiency, a method of mixing with a cooled solvent is preferable.

  The average primary particle diameter of the thermoplastic resin particles obtained by cooling is 10 to 10000 nm, preferably 10 to 8000 nm, more preferably 10 to 5000 nm, and still more preferably 10 to 3000 nm. When the average primary particle diameter exceeds 10,000 nm, the film thickness of the coating film becomes large, or there is a tendency that problems such as not becoming a continuous film occur when it is made into a thin film. When it is less than 10 nm, the viscosity of the obtained suspension tends to be high, and the separation operation tends to be difficult.

  The average primary particle diameter of the thermoplastic resin particles is as described above, but such particles usually aggregate to form secondary particles. The average secondary particle diameter of the particles thus formed is preferably 50 μm or less, and more preferably 1 to 10 μm.

  When the average secondary particle diameter exceeds 50 μm, the film thickness tends to increase when applied, and the desired coating film tends not to be obtained.

  Here, the primary particles refer to particles that cannot be dispersed any more. Secondary particles refer to particles in which primary particles are aggregated.

  Examples of the method for separating the particles from the suspension containing the particles include filtration and centrifugation, but are not limited thereto. Examples of the filter for filtering include a ceramic filter.

  Coloring materials such as pigments and dyes are added to the thermoplastic resin in order to adjust the paint-coated dental metal product of the present invention to white, crown color, or gingival color. The coloring material to be added includes organic dyes and pigments, metal oxides, metal halides, etc., but metal oxides are preferable in terms of safety, stability of color tone, and heat resistance during application, particularly white or crown. Titanium oxide, bengara, titanium yellow, black iron oxide, and yellow iron oxide are particularly preferred for making color.

  In particular, in the case of particles such as inorganic materials typified by the metal oxide, when dispersed, the particles preferably have a fine particle size equivalent to that of the thermoplastic resin particles.

  The metal coating paint is made of thermoplastic resin particles. However, it may be composed of a mixture of the thermoplastic resin particles, or an additive such as a curing agent may be added to the thermoplastic resin particles. Further, the thermoplastic resin particles may be used by adding to other paints. It is preferable to add the thermoplastic resin particles to other paints because a tougher coating film can be formed.

  The other paint to which the thermoplastic resin particles are added is not particularly limited as long as it is generally used as a paint, but is not limited to polyester resin, cross-linked acrylic resin, epoxy resin, urethane resin, melamine resin, The thermosetting coating material which consists of a phenol resin, a urea resin, etc. can be mentioned.

  Examples of solvents for dispersing the thermoplastic resin particles include ester solvents such as ethyl acetate and butyl acetate; dibasic acid ester solvents such as dimethyl adipate, dimethyl glutarate and dimethyl succinate: cyclohexanone, isophorone, and methyl isobutyl. Ketone solvents such as ketones; hydrocarbon solvents such as cyclohexane, toluene and xylene; alcohol solvents such as benzyl alcohol and cyclohexanol; ethylene glycol monobutyl ether, dipropylene glycol butyl ether, bis (2-methoxyethyl) ether, etc. Ether solvents; amide solvents such as formamide, dimethylformamide, dimethylacetamide; pyrrolidone solvents such as N-methyl-2-pyrrolidone (NMP) and water, and mixtures thereof Although the like, is not limited thereto, it is possible to use any organic solvent suitable for the coating to be obtained.

  When the thermoplastic resin is polyethylene terephthalate, a mixed solvent based on cyclohexanone and xylene, dimethyl adipate, dimethyl glutarate and dimethyl succinate, dimethylacetamide is preferred, and the thermoplastic resin is polyethylene naphthalate. In some cases, dimethylacetamide and N-methyl-2-pyrrolidone are preferred, and when the thermoplastic resin is MXD6-nylon, dimethylacetamide and water are preferred, and when the thermoplastic resin is 12-nylon, dimethylacetate is preferred. Acetamide and benzyl alcohol are preferred. When the thermoplastic resin is 66-nylon, benzyl alcohol is preferred. When the thermoplastic resin is 6-nylon, dimethylacetamide, benzyl alcohol, N-methyl- 2-pyrrolidone is preferred, and when the thermoplastic resin is polylactic acid, dimethylacetamide, ethyl acetate, butyl acetate, dimethyl succinate, and methyl isobutyl ketone are preferred. When the thermoplastic resin is polyglycolic acid, bis ( 2-methoxyethyl) ether and toluene are preferred, and when the thermoplastic resin is polycarbonate, a mixed ester solvent comprising dimethylacetamide, cyclohexanone, dimethyl adipate, dimethyl glutarate and dimethyl succinate is preferred. When dispersing, a commonly used dispersant may be used. The amount of the dispersant used is not particularly limited, and can be used as long as the desired performance of the coating film is not impaired.

  If necessary, for example, acid catalysts such as sulfonic acids such as p-toluenesulfonic acid and dodecylbenzenesulfonic acid, phosphoric acids such as alkylphosphoric acid, curing aids such as amine block of the acid catalyst, leveling agents, Additives such as a wetting agent, an antifoaming agent, and a lubricant may be blended.

The addition amount of the thermoplastic resin particles is preferably 5% by weight or more, more preferably 10% by weight or more, and more preferably 15% by weight or more in the total nonvolatile components contained in the paint. It is preferably 20% by weight or more. When the addition amount of the thermoplastic resin is less than 5% by weight, the intended effect tends not to be obtained.
Further, the ratio of the thermoplastic resin particles and the solvent is not particularly limited, and may be appropriately adjusted according to the desired coating film.

  Examples of the method for dispersing the thermoplastic resin particles include dispersion by ultrasonic waves and dispersion by a stirrer. Examples thereof include a homogenizer, a homomixer, a roll mill, a bead mill, and a high-pressure wet pulverization apparatus.

  When secondary particles are dispersed in a solvent, it is preferable to select a solvent and a dispersion method to atomize, and it is more preferable to finally make primary particles. By atomizing, it becomes possible to control the coating thickness to a desired thickness, and it is possible to finish a smoother coating.

  The paint of the present invention can be applied by a known method such as a spray coating method, a brush coating method, a spatula coating method, a dip coating method, an electrodeposition coating method, or an electrostatic coating method.

When the coating is formed using the paint of the present invention, the coating amount of the paint is preferably 0.1 to 50 g / m ² , preferably 1 to 50 g / m ² after drying. m ² , more preferably 3 to 20 g / m ² , and even more preferably 3 to 10 g / m ² .

  The coating film is formed from the paint of the present invention by applying the paint, evaporating the solvent by heating, and then melting the particles. Thereby, there is no pinhole, a uniform coating film is formed, and a coating film excellent in aesthetics, safety, slipperiness, contamination resistance, bending resistance, abrasion resistance, and the like is obtained.

  100-300 degreeC is preferable, the heating temperature at the time of applying the said coating material has more preferable 150-290 degreeC, and 200-285 degreeC is further more preferable. If the lower limit of the numerical range is not reached, there is a risk that a film having sufficient durability due to insufficient evaporation of the solvent or insufficient softening / melting of the resin or insufficient crystallization may not be formed, and if the upper limit of the numerical range is exceeded, There is a risk of causing deterioration of resin physical properties such as resin coloring.

  The heating time is preferably 1 to 60 minutes, more preferably 1.5 to 30 minutes, and more preferably 2 to 20 minutes. If the lower limit of the numerical range is not reached, there is a risk that a film having sufficient durability due to insufficient evaporation of the solvent or insufficient softening / melting of the resin or insufficient crystallization may be formed, and if the upper limit of the numerical range is exceeded, There is a risk of causing deterioration of resin physical properties such as resin coloring.

  It is possible to adjust the crystallinity level of the coating film by adjusting the heating temperature, time, and subsequent cooling rate. In order to maintain the strength of the coating film, the thermoplastic resin, particularly the aromatic polyester resin, preferably has crystallinity.

  The coating-coated dental metal product of the present invention includes orthodontic wires, orthodontic brackets, orthodontic buccal tubes, orthodontic bands, orthodontic ligatures & shorty wires, orthodontic closed coil springs, orthodontic appliances. Lingual attachment, orthodontic lip bumper, orthodontic retainer, orthodontic expander, dental prosthesis inlay, dental prosthesis onlay, dental prosthetic crown, dental prosthetic bridge, dental denture base metal device (clasp, lingual) Bars, paratal bars, metal floors, etc.) are obtained by coating with the paint of the present invention. The manufacturing method of the metal product at this time is not particularly limited, and the shape of the metal product is not limited as long as it is for dental use.

  The paint-coated dental metal product of the present invention has excellent aesthetics, safety, slipperiness, stain resistance, bending workability, and wear resistance.

Next, the paint of the present invention will be described based on examples, but the present invention is not limited thereto.
<Film thickness>
Measurement is performed using an electromagnetic induction / overcurrent film thickness meter (LZ-200W, manufactured by Kett Science Laboratory Co., Ltd.).
<Pencil hardness>
Based on the method described in JIS K-5400 (1990), the measurement was performed using Uni (trade name) manufactured by Mitsubishi Pencil Co., Ltd.
<Solvent resistance>
Sixteen pieces of gauze are fixed on the convex part of a 2-pound hammer, moistened with methyl ethyl ketone, and then reciprocated on the coating plate, and the number of times when the coating film is peeled is regarded as solvent resistance.
<Impact resistance>
In accordance with the method described in JIS K-5400 (1990), a DuPont impact machine (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used. After that, Nichiban Co., Ltd. cello tape (registered trademark) was affixed to the convex part, and after sticking well, it was peeled off in a direction of 90 degrees with respect to the coating surface, and the state of the convex coating surface was visually observed. The evaluation is based on the following evaluation criteria.
A: No peeling at all.
B: Partial peeling is observed.
C: Peeling is observed as a whole.
<Bendability>
A mandrel vent tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used. The measurement was carried out at 1T (one test was placed between the bent test plates, and the test was conducted with the same plate in between). After that, Nichiban Co., Ltd. cellotape (registered trademark) was affixed to the convex part, and after sticking it well, it was peeled off in a direction of 90 degrees with respect to the coating surface, and the state of the convex coating surface was visually observed. Observe and evaluate based on the following evaluation criteria.
A: No peeling at all.
B: Slight beard-like peeling with a length of less than 0.5 mm is observed, but this is practically acceptable.
C: Peeling with a length of 0.5 mm or more is observed.
D: Peeling is already observed before cellotape (registered trademark) is applied.
<Abrasion resistance>
Using a Gakushin robust wear tester (manufactured by Yasuda Co., Ltd.), place a load of 1000 g on the surface of 10 mmφ, and visually observe the surface of the test piece after it was reciprocally worn 100 times with Kanakin No. 3 cloth. And evaluated according to the following evaluation criteria.
A: When the width of the scratch is 0.0 to 0.5 mm (0 to 5%) B: When the width of the scratch is 0.6 to 2.5 mm (6 to 50%) C: The width of the scratch When it is 2.6 to 9.5 mm (51 to 95%) D: When the width of the scratch is 9.6 to 10.0 mm (96 to 100%)

[Example 1]
Average primary particle diameter 300 nm Polyethylene terephthalate resin (PET) particles 8% dimethylacetamide dispersion: 100 g (resin solid content 8 g) titanium oxide (Taika JR-301 average particle diameter 0.3 μm): 10.4 g 2 mm beads: 100 g was weighed into 240 g mayonnaise bins and dispersed for 24 hours using a paint shaker. Further, 1 g of carnauba wax dispersion (SL506 dispersion in dipropylene glycol mono-n-butyl ether, solid content: 18.5%, manufactured by San Nopco Co., Ltd.) was added, and the mixture was well stirred and filtered to give paint 1 (Production Example 1) .

The obtained paint was applied to an unpainted aluminum plate (5052 material, plate thickness 0.23 mm, 12 cm × 20 cm) using a bar coater # 34 so that the film thickness after drying was 5 μm (coating amount after drying) 7.0 g / m ² ), and placed in a hot air circulation oven (manufactured by Satake Seisakusho Co., Ltd.) set at 260 ° C. for 2 minutes for drying.

[Examples 2 to 10]
The same amount of titanium oxide and carnauba wax as in Production Example 1 was added to 8 g of resin solid content of various resin particle dispersions, and the beads were dispersed in the same manner to obtain the coating materials for metal coating of Production Examples 2 to 10 shown in Table 1. It was.
The obtained paint was applied in the same manner as in Example 1 to form a coating film at each set temperature to prepare a test plate.

[Examples 11 to 13]
Carnauba wax 1 g (S L 506 dipropylene glycol mono-n-butyl ether dispersion solid content 18.5%; manufactured by San Nopco Co., Ltd.) was added to the resin solid content 8 g of various resin particle dispersions, and the beads were similarly dispersed. The metal coating compositions of Examples 11 to 13 shown in Table 1 were obtained.
The obtained paint was applied in the same manner as in Example 1 to form a coating film at each set temperature to prepare a test plate.
The results of the performance test of the obtained coating film are shown in Table 2.

Modified PEN resin: 2,6 naphthalene dicarboxylic acid 80 mol% terephthalic acid 20 mol% 1,4 cyclohexanedimethanol (CHDM) 40 mol% ethylene glycol 60 mol% Resin DMAC Dimethylacetamide NMP ... n-methyl-2-pyrrolidone [Example 14]
A paint prepared by adding 0.062 parts by weight of titanium yellow and 0.0005 parts by weight of Bengala tea and 0.16 parts by weight of synthetic iron yellow as pigments to 100 parts by weight of the paint prepared in Example 1 and adjusting the color tone to the crown color. Got ready.

  This paint is applied to the orthodontic Ni-Ti wire (Thermalloy wire: Rocky Mountain Morita Co., Ltd.) and orthodontic bracket (Synergy Bracket: Rocky Mountain Morita Co., Ltd.) with a thickness of 15μm ± 5μm. And a wire and a bracket having a crown color.

The crown-colored wire and bracket were mounted on a dental education jaw model, and the aesthetics were compared with the case of mounting an unpainted wire and bracket [(Photo 1: Crown-colored wire and bracket) and (Photo 2: unpainted wire and bracket)].
As a result, it was confirmed that the aesthetics when the crown-colored wire and the bracket were attached were much higher than when the unpainted wire and the bracket were attached.

Example 15
The paint prepared in Example 1 was applied to stainless steel wire # 22 (diameter 0.7 mm) and # 28 (diameter 0.35 mm: both SUS304-W1 manufactured by Wakai Sangyo Co., Ltd.) with a film thickness of 10 μm ± 2 μm and heated to 260 ° C. It was placed in a set hot air circulation oven (manufactured by Satake Manufacturing Co., Ltd.) for 2 minutes and dried.
This was subjected to the following <Scratch test for wire paint> and <Skin crack test>, and the results are shown in Tables 4 and 5.
<Scratch test for wire paint (rubbing method)
A stainless steel wire coated with paint on a 1 pound hammer was fixed with cello tape and reciprocated on cardboard (made by Hokuetsu Kishu Paper Co., Ltd.), and the number of times until the base was seen was examined.
<Wearing test of coating film (bending and stretching method)>
The number of times until the paint film cracked was investigated by bending or extending the stainless steel wire coated with paint.

Example 16
The paint prepared in Example 3 was applied to stainless steel wire # 22 (diameter 0.7 mm) and # 28 (diameter 0.35 mm: both SUS304-W1 manufactured by Wakai Sangyo Co., Ltd.) with a film thickness of 10 μm ± 2 μm and heated to 260 ° C. It was placed in a set hot air circulation oven (manufactured by Satake Manufacturing Co., Ltd.) for 2 minutes and dried.
This product was subjected to the following <Blemish test of wire paint> and <Draft test of coating film>, and the results are shown in Tables 4 and 5.

[Comparative Example 1]
Stainless steel wire # 22 (diameter 0.7mm) and # 28 (both 0.35mm diameter: Wakai Sangyo Co., Ltd.) SUS304-W1) was coated with a film thickness of 10 μm ± 2 μm, placed in a hot air circulation oven (manufactured by Satake Corporation), and dried under the conditions shown in Table 3.
This was subjected to the following <Scratch test for wire paint> and <Skin crack test>, and the results are shown in Tables 4 and 5.

[Comparative Example 2]
Stainless steel wire # 22 (diameter 0.7 mm) and # 28 (diameter 0.35 mm: both made by Wakai Sangyo Co., Ltd.) SUS304- W1) was coated with a film thickness of 10 μm ± 2 μm, placed in a hot air circulation oven (manufactured by Satake Manufacturing Co., Ltd.), and dried under the conditions shown in Table 3.
This was subjected to the following <Scratch test for wire paint> and <Skin crack test>, and the results are shown in Tables 4 and 5.

[Comparative Example 3]
Stainless steel wire # 22 (0.7mm diameter) and # 28 (0.35mm diameter: both Wakai Sangyo Co., Ltd.) thermosetting resin paint (polyester amino resin paint: containing titanium oxide) commonly used for metals SUS304-W1) was coated with a film thickness of 10 μm ± 2 μm, placed in a hot air circulation oven (manufactured by Satake Corporation), and dried under the conditions shown in Table 3.
This was subjected to the following <Blemish test of wire paint> and <Draft test of coating film>. The results are shown in Table 4.

Claims (9)

  A paint-coated dental metal product characterized by applying a paint containing a thermoplastic resin to a dental metal product.   The paint-coated dental metal product according to claim 1, wherein the applied coating thickness is 35 μm or less.   The paint-coated dental metal product according to claim 1, wherein the thermoplastic resin is at least one resin selected from the group consisting of an aromatic polyester resin, an aliphatic polyester resin, a polyamide resin, a polycarbonate resin, and a modified polyolefin resin.   The paint-coated dental metal product according to claim 1 or 2, wherein the paint-coated dental metal product has a non-cylindrical shape and / or a non-planar shape. An arbitrary point P on the surface of the paint-coated dental metal product has a shape in which a point Q on the surface of the paint-coated dental metal product satisfies the following condition (A): The paint-coated dental metal product according to any one of items 1 to 3;
Condition (A) = Condition (A0) ∩ [Condition (A1) ∪Condition (A2)]
Condition (A0): The linear distance between PQ is 20 mm or less.
Condition (A1): The minimum curvature radius of the surface at the point Q is 5 mm or less.
Condition (A2): The maximum curvature radius of the surface at the point Q is 1000 mm or less.   Paint coated dental metal products include orthodontic wires, orthodontic brackets, orthodontic buccal tubes, orthodontic bands, orthodontic ligatures & shorty wires, orthodontic closed coil springs, orthodontic lingual attachments , Orthodontic lip bumper, orthodontic retainer, orthodontic expander, dental prosthesis inlay, dental prosthesis onlay, dental prosthetic crown, dental prosthetic bridge, dental denture base metal equipment (clasp, lingual bar, paratalbar) The metal-coated dental metal product according to claim 1.   5. The paint-coated dental metal product according to claim 1, which has a linear shape.   8. The paint-coated dental metal product according to claim 7, wherein the linear shape has a diameter of 1 mm or less.   2. The paint-coated dental metal product according to claim 1, wherein the color tone of the paint containing the thermoplastic resin is white, crown color or gingival color.