JP5604064B2 - Color titanium products that have low fingerprints and are highly resistant to scratches - Google Patents

Description

  The present invention includes an architectural interior material and exterior material, a kitchen member, tableware, furniture, an instrument, an electrical equipment exterior, an electronic equipment casing, a clock, a camera, glasses, an accessory, a decorative article, and a railway, an automobile, a ship, and an aircraft. The present invention relates to a color titanium product that is used for interior materials such as, etc. and has a surface that can be easily wiped off even if fingerprints are not noticeable or adhere to fingerprints, and has excellent design.

  In recent years, titanium products have come to be used in large quantities for applications requiring surface aesthetics, such as interior and exterior materials for buildings, ornaments such as watches, cameras, and glasses, and housings for electronic devices. This is because designers and users prefer the unique texture and luxury in addition to the excellent corrosion resistance, which is the greatest feature of titanium, and harmlessness to the human body and living body. Therefore, these titanium products are often required to have a design and an aesthetic appearance. In particular, titanium can be provided with a color-developing layer with an interference color on the surface by an anodic oxidation method or the like, but such a color titanium product is highly preferred for various uses because of its high-class feeling.

  However, when titanium is used in the state of a metal surface, there are problems such as that fingerprints are attached and are easily noticeable, and attached fingerprints are difficult to wipe off. In particular, a titanium product colored on the surface by anodic oxidation coloring has a drawback that fingerprints are more conspicuous and the commercial value is reduced.

  The reason why fingerprints are more noticeable with titanium products is that when fingerprints (organic substances such as oils and fats) adhere to the surface of the titanium or titanium oxide layer, even if it is a small amount and itself is colorless and transparent, metal This is because the surface and the organic matter have different light scattering coefficients, and the attached portion is noticeable. Although this does not impair the material properties of titanium, in recent years, in the field where titanium is used with emphasis on the design of titanium, the beauty of the surface is impaired and the commercial value is reduced. There is an increasing demand for the characteristic that fingerprints are inconspicuous or easy to wipe off even if attached.

  As a method for solving this, generally, means for clear coating on a metal surface has been empirically adopted. This is intended to prevent the fingerprint adhesion portion from conspicuously by applying a resin or the like whose light scattering coefficient is relatively close to that of the oil and fat component to the metal surface. There are organic and inorganic materials for these clear coating materials. Like titanium, products with clear coating on stainless steel, where fingerprints are conspicuous when used in a solid state, are widely used. For example, Patent Document 1 discloses a clear resin-coated metal plate that is excellent not only in fingerprint resistance but also in scratch resistance. By controlling the surface roughness of the clear coating film, a metallic color appearance is disclosed. There are times when it is difficult to stand out while holding.

  Further, Patent Document 2 proposes a stainless steel with good fingerprint stain resistance, characterized by using a stainless steel to which titanium is added and performing a heat treatment for forming titanium oxide on the surface thereof. It is described that it is possible to remove stains due to fingerprints or the like by utilizing the photocatalytic action generated by applying ultraviolet rays to the titanium oxide layer thus formed on the surface. Further, Patent Document 3 proposes a method for improving fingerprint resistance by coating a stainless steel surface with a compound having a bond of fluorine and carbon. This utilizes the effect that oils and fats components are difficult to adhere to a compound having a bond between fluorine and carbon. Conventionally, the compound that could only be thickened and could not retain the texture of the steel sheet was embedded in the grain boundary groove. It is introduced that it was able to overcome. In addition, although the above literature is the technique which showed the application example to stainless steel or steel, since it is thought that it is easily applicable also to titanium products, it referred.

  However, all of these technologies are achieved by attaching a substance different from the base material to the surface. In this case, first, the surface condition (coating film, titanium oxide layer, compound layer) is changed over time. It is easily imagined that will change. Therefore, after a certain period of time, the surface state changes, and the initial performance cannot be maintained. In addition, even if it is thinned, the design property of the metal surface itself cannot be maintained, and there is a problem that it cannot be applied when the texture or high quality of titanium itself is desired. Furthermore, in particular, with anodized coloring titanium that develops color by utilizing the interference of light on the surface titanium oxide layer, the thickness of the surface film changes due to the clear coat application, and the originally colored color is There is a problem that it cannot be finished in a favorite color because it changes.

  On the other hand, the roll dull method, in which the rolling is transferred to the product surface by cold rolling using a rolling roll with irregularities on the surface, imparts an appropriate surface roughness to the plate product and improves the anti-fingerprint resistance. A stainless steel plate and a manufacturing method thereof are proposed in Patent Document 1. However, in this method, the product shape is limited to a thin plate product that has been cold-rolled, and it is a technique that is difficult to apply to a product that is subsequently subjected to secondary processing such as press molding. In addition, if the processing by roll molding is performed after color development, the color-developing layer is peeled off, and even if the color is developed after processing, the fingerprint resistance is not improved. Therefore, application to color titanium is not practical.

  Further, Patent Document 4 discloses an optical phenomenon generated in a metal plate having various surface properties, a power spectral distribution of surface roughness is measured, and a surface property in which fingerprints are not conspicuous is quantified. However, as described in the literature, it is difficult to say that the optimum method for producing a metal plate that satisfies this condition has been found until the publication of the literature.

JP 2002-361303 A JP-A-8-193218 JP 2005-68503 A JP 2001-47105 A

  In view of the current situation as described above, the present invention provides a color titanium material that is not noticeable even if fingerprints are attached or can be easily wiped off, and that is excellent in anti-wrinkle and design properties. .

  The inventors performed surface treatment on the anodically oxidized titanium material by various practical methods, and conducted extensive research on surface skin that is difficult to notice or easy to wipe off even if the fingerprint is attached. As a result, a uniform dent is made on the titanium surface, and the color is developed in that portion, and the diameter and depth of the dent are controlled, and a gentle flat surface having an appropriate surface roughness is properly formed on the ridge of the dent. It has been found that by providing a small area ratio, the fingerprint is not noticeable or can be easily wiped off even if the fingerprint is attached.

The gist is as follows.
(1) The surface is colored by an anodizing method, and has an average diameter of 20 to 150 μm and a recess having an average depth of 3 to 30 μm from the adjacent convex portion (ridge) on the surface, and the adjacent convex portion The (ridge) part has color development removed, and has a smooth flat part with a surface roughness Ra of 0.10 to 1.50 μm, and the area ratio of the flat part is 10 to 60% of the whole. In addition, the maximum hardness at a depth of 50 μm from the outermost surface is 40 to 150 points higher in Vickers hardness (Hv0.02) than the base material, fingerprints are not noticeable and wrinkles are not easily observed, Color titanium products with excellent design.
(2) The color titanium product as described in (1) above, wherein the color titanium product is one of a container, an electronic device casing, a building, or a member thereof excellent in design .

  The inventors made various studies on the surface skin of the titanium material that has been anodically colored by various practical methods, and conducted intensive research on the surface skin that is difficult to notice or easy to wipe off even if the fingerprint is attached. As a result, the surface is provided with a dent uniformly, and a coloring layer is provided on the surface, and a smooth flat portion having an appropriate surface roughness is provided on the ridge of the dent by subsequent polishing, etc. In addition, it was clarified that fingerprints are not noticeable or easy to wipe off even if they are attached. This is because the titanium surface having such a structure has a structure in which sebum adheres more easily than the titanium surface and the finger is less likely to directly touch the anodized coloring layer that is difficult to remove. Moreover, since the titanium surface having such irregularities has an appropriate smoothness, it is possible to prevent sebum from locally sticking and becoming conspicuous as a fingerprint, and at the same time, it is easy to wipe off even if sebum adheres. Furthermore, by adjusting the surface hardness appropriately, resistance to scratches is increased, scratches are less likely to be scratched, and at the same time, the surface morphology is also maintained, so that the effect of making fingerprints less noticeable can be maintained for a long period of time. .

  In the present invention according to claim 1 (hereinafter referred to as the present invention (1)), the surface has uniformly a recess corresponding to a diameter of 20 to 150 μm and a depth of 3 to 30 μm, and a protrusion adjacent to the recess. The portion (ridge) has a smooth flat portion with a surface roughness Ra of 0.1 to 1.5 μm, and the flat portion is free of color development, and the area ratio of the flat portion is 10 to 60% of the whole In addition, the maximum hardness at a depth of 50 μm from the outermost surface is 40 to 150 points higher than the base material in terms of Vickers hardness (Hv 0.02). Color titanium product.

  At this time, in the dent portion where the color forming layer is provided by the anodic oxidation method, when the average diameter of the dent portion is less than 20 μm and the average depth is less than 3 μm, it becomes the same as the surface skin with less unevenness, and the fingerprint resistance is not improved. When the average diameter of the dents exceeds 150 μm and the average depth exceeds 30 μm, it tends to remain when sebum adheres, and the fingerprint resistance decreases in both cases. At this time, when high designability and fingerprint resistance are required, it is desirable that the average diameter of the recesses provided on the surface is in the range of 30 to 120 μm and the average depth is in the range of 5 to 20 μm. Moreover, in the part of the convex part (ridge) adjacent to the dent, a flat part from which coloring is removed is provided, and when the surface roughness of the part is less than 0.1 and more than 1.5 in Ra, The resistance of the surface against the fingertip increases, and the fingerprint is likely to remain. Further, when the area ratio of the flat portion is less than 10% of the entire surface, the surface becomes the same as a simple uneven surface, and the frictional resistance against the fingertip is also increased, so that the fingerprint resistance is lowered. On the contrary, when the area ratio of the flat portion exceeds 60%, it approaches a flat surface form with less unevenness. In this case as well, the frictional resistance against the fingertip increases and the fingerprint resistance decreases, and the area of the colored portion decreases. It becomes difficult to obtain the desired color tone.

  Furthermore, if the maximum value of Vickers hardness (Hv0.02) at a depth of 50 μm from the outermost layer is less than 40 points compared to the base material, scratches are likely to occur, and if the hardness exceeds 150 points Since the outermost layer becomes brittle and easily peels off, the difference in hardness between the two is in the range of 40 to 150 points.

  As the color titanium product of the present invention is defined in the present invention according to claim 2 (hereinafter referred to as the present invention (2)), any one of a container, an electronic equipment casing, a building or a member thereof excellent in design properties It is preferable that it is. By applying the present invention to these products, the feature of the present invention that fingerprints are not conspicuous and wrinkles are difficult to be applied can be utilized particularly well.

  The color titanium product of the present invention can be manufactured by the following manufacturing method.

By blasting the surface of the titanium plate, the recess of the present invention can be formed, and a hardness of 50 μm from the outermost surface (Hv 0.02 difference from the base material) can be imparted. Next, the entire surface can be colored by performing anodic oxidation coloring. Thereafter, the surface is polished to remove the color of the convex portion (ridge), and the surface roughness of the convex portion is also within the scope of the present invention. As for the blast treatment, for example, zirconia beads having an average particle diameter of 50 to 500 μm can be treated at a projection pressure of 0.3 to 0.4 MPa. The anodic oxidation color can be processed by applying a voltage of 30 V in, for example, a 10 g / L sulfuric acid-10 g / L phosphoric acid bath having a bath temperature of 20 ° C. For surface polishing, for example, in 300 g of 5% citric acid aqueous solution, 200 g of a stainless steel pin having a diameter of 0.3 mm and a length of 5 mm and 100 g of a stainless steel ball having a diameter of 1.0 mm are placed for 2 minutes to 1 hour. Barrel polishing can be performed by electromagnetic stirring at 200 revolutions per minute. Alternatively, polishing can be performed by rotating eccentrically with a load of 2 kg / 10 cm ² using a nylon non-woven fabric to which number 1000 abrasive grains are attached.

  The surface shape of the color titanium product of the present invention can be measured by, for example, a three-dimensional laser microscope. The point where the surface is colored and the point where the colored part is removed from the convex part can be evaluated by an optical microscope using a white light source. The maximum hardness at a depth of 50 μm from the outermost surface can be measured with a micro Vickers (Hv 0.02) by preparing a cross-sectional sample of a color titanium product.

Example 1
About the example of the present invention shown in Table 1, after blasting a zirconia bead having an average particle diameter of 50 to 500 μm on a plate surface made of pure titanium type 1 (JIS H4600 TP270C) at a projection pressure of 0.4 MPa, a bath temperature of 20 ° C. Anodizing color development was performed by applying a voltage of 30 V in a 10 g / L sulfuric acid-10 g / L phosphoric acid bath. Along with this, 200 g of a stainless steel pin having a diameter of 0.3 mm and a length of 5 mm and 100 g of a stainless steel ball having a diameter of 1.0 mm are placed in 300 g of a 5% aqueous citric acid solution for 200 minutes per minute for 2 minutes to 1 hour. Barrel polishing was performed by electromagnetic stirring with rotation. By these treatments, the surface morphology shown in Table 1 and a hardness of 50 μm from the outermost surface (Hv 0.02 difference from the base material) were imparted.

  About the comparative example, the product quality was changed by changing some conditions, making the manufacturing conditions of the said invention example into a reference | standard. That is, the average particle diameter of the used zirconia beads is 40 μm for the test number 1 of the comparative example and 750 μm for the test number 6. The blast projection pressure is 0.1 MPa for the test number 7 of the comparative example and 1.5 MPa for the test number 6. Blasting was performed for test number 17 of the comparative example for 3 seconds and test number 21 for 20 minutes. The barrel polishing time was 5 hours for the test number 12 of the comparative example and 10 seconds for the test number 16. The shot grains used are test number 22 having an average particle diameter of 400 μm and specific gravity of 2.0 ferrochrome slag (JIS Z 0312), test number 26 having a particle size of 400 and specific gravity of 7.9 high carbon cast steel shot (JIS Z 0311). Met.

  The surface shape of the color titanium product was measured using a three-dimensional laser microscope (Keyence Color 3D Laser Microscope VK-9700). Whether or not the surface of the dent was colored and whether or not the colored portion was removed from the convex portion were evaluated by observation with an optical microscope 500 times using a white light source.

  The maximum hardness at a depth of 50 μm from the outermost surface is to make a hard resin embedded cross section sample of color titanium product, wet emery paper polishing, electrolytic polishing with anhydrous electrolyte, with micro Vickers (Hv 0.02), Measurements were made at 5 points from the outermost layer at a distance of 50 μm, 100 μm or more apart, and the maximum value was obtained. The hardness of the base material was measured at a position of the center of the plate thickness of the same cross-sectional sample at 5 points, 100 μm or more away from each other, and the average value was defined as the hardness of the base material.

  Table 1 also shows the results of evaluation of fingerprint resistance, anti-scratch resistance and color tone.

  Fingerprint resistance is the result of 10 people seeing whether the fingerprint is actually pressed and not noticeable or wiped away with a waste cloth, and 7 or more of them are "the fingerprint is not noticeable as it is." In addition, when it was determined that “it did not remain after wiping with a waste cloth”, it was judged as good (◯ in the table).

  In addition, with respect to the rust resistance, two titanium materials (10 × 10 cm plate) shown in Table 1 are prepared, and one of them is combined with two 10-yen coins and two 100-yen coins, Put it in a long No. 3 envelope, put all 26 envelopes in the bag, and put each envelope in a movable state when you shake the bag by hand. Carried on weekdays for half a year. After that, by comparing with another titanium material that had been stored without being carried, the surface state was visually observed by 10 people, and it was determined whether or not scratches were noticeable. In this case, it was marked as ○ when there were 6 or more people who were not noticeable, and x when it was 5 people or less.

  Furthermore, as for the color tone, the surface condition before and after the polishing treatment was compared with 10 people, and when there were 3 or more people who evaluated that the color tone was significantly different before and after the polishing, the color tone was rated as “X”. Table 1 shows the evaluation results together with the test conditions. In Table 1, numerical values that deviate from the scope of the present invention are underlined.

  In Table 1, test numbers 2, 3, 4, 5, 8, 9, 10, 13, 14, 15, 18, 19, 20, 23 having the surface morphology and surface hardness described in the present invention (1). , 24, and 25 were all good in evaluation results of fingerprint resistance, wrinkle resistance and color tone. On the other hand, Test Nos. 1, 6, 7, 11, 12, 16, 17, and 21 all had a noticeable fingerprint and poor wiping property, and the evaluation of fingerprint resistance was low. Among these, test numbers 1 and 6 do not have the average diameter of the dents in the appropriate range described in the present invention (1), and test numbers 7 and 11 indicate the appropriate values described in the present invention (1). In other words, the average depth of the dents is not within a certain range. This is because the average diameter and depth of the dents are not appropriate, so that sebum easily accumulates locally or is difficult to wipe off. Test numbers 12 and 16 do not satisfy the ridge portion surface roughness in the proper range described in the present invention (1), and test numbers 17 and 21 indicate ridge portions in the proper range described in the present invention (1). The area ratio is not satisfied. The surface roughness and area ratio of the ridges are effective for the frictional resistance with the fingertips and the resistance during wiping. In these test numbers, the surface roughness and area ratio of the ridges were not in an appropriate range, so that sebum was easily collected and the ease of wiping off fingerprints was impaired.

  Furthermore, among these, Test No. 21 had a low fingerprint resistance evaluation and a low color tone evaluation. In this test number, the fact that the area ratio of the flat part of the ridge is larger than the range described in the present invention (1) means that the dent part provided with the coloring layer is greatly shaved. This is because the color tone has changed from the developed state of.

  In test numbers 22 and 26, the evaluation of the scratch resistance was low. In Test No. 22, the surface hardness was below the lower limit described in the present invention (1), so that wrinkles were easily formed, and the tackiness was clearly poor. On the other hand, in the case of test number 26, in order to evaluate the scratch resistance, a part of the surface layer was dropped while being carried in a bag together with the coin for half a year. Could not be evaluated. This is because the surface layer is too hard and brittle and breaks when it comes into strong contact with the coin.

  Regarding the color development on the surface, it was confirmed that in both the present invention example and the comparative example, the dent portion was colored and the convex portion was removed.

(Example 2)
About the example of the present invention shown in Table 2, after blasting a zirconia bead having an average particle diameter of 50 to 500 μm on a plate surface made of pure titanium type 1 (JIS H4600 TP270C) at a projection pressure of 0.3 MPa, a bath temperature of 20 ° C. Anodizing color development was performed by applying a voltage of 30 V in a 10 g / L sulfuric acid-10 g / L phosphoric acid bath. Polishing was performed by rotating eccentrically with a load of 2 kg / 10 cm ² using a nylon non-woven fabric to which number 1000 abrasive grains adhered. By these treatments, the surface morphology described in Table 2 and a hardness of 50 μm from the outermost surface (difference of Hv 0.02 from the base material) were imparted.

  About the comparative example, the product quality was changed by changing some conditions, making the manufacturing conditions of the said invention example into a reference | standard. That is, the average particle size of the zirconia beads used was 40 μm for the test number 27 of the comparative example and 750 μm for the test number 32. The blast projection pressure is 0.1 MPa for test number 33 and 1.5 MPa for test number 32 in the comparative example. Blasting was performed for 3 seconds for test number 43 of the comparative example and for 20 minutes for test number 47. As for the abrasive grains used, the test number 38 of the comparative example was alumina having an average particle size of 0.1 μm, and the test number 42 was 120. The shot grains used were test number 48 of ferrochrome slag having an average particle size of 400 μm and specific gravity of 2.0 (JIS Z 0312), test number 52 of high carbon cast steel shot having a particle size of 400 and specific gravity of 7.9 (JIS Z 0311). Met.

  The method for evaluating the surface properties and hardness of the product is the same as in Example 1 above.

  Table 2 also shows the results of evaluation of fingerprint resistance, anti-scratch resistance and color tone. The evaluation methods for fingerprint resistance, anti-scratch property, and color tone are the same as in Example 1.

  Table 2 shows the evaluation results together with the test conditions. In Table 2, numerical values outside the scope of the present invention are underlined.

  In Table 2, test numbers 28, 29, 30, 31, 34, 35, 36, 39, 40, 41, 44, 45, 46, 49 having the surface morphology and surface hardness described in the present invention (1). , 50 and 51 were good in all evaluation results of fingerprint resistance, wrinkle resistance and color tone. On the other hand, Test Nos. 27, 32, 33, 37, 38, 42, 43, and 47 all had a conspicuous fingerprint and poor wiping property, and the evaluation of fingerprint resistance was low. Among these, the test numbers 27 and 32 do not have the average diameter of the dents in the appropriate range described in the present invention (1), and the test numbers 33 and 37 are the appropriate values described in the present invention (1). In other words, the average depth of the dents is not within a certain range. This is because the average diameter and depth of the dents are not appropriate, so that sebum easily accumulates locally or is difficult to wipe off. Test numbers 38 and 42 do not satisfy the ridge portion surface roughness in the proper range described in the present invention (1), and test numbers 43 and 47 indicate ridge portions in the proper range described in the present invention (1). The area ratio is not satisfied. The surface roughness and area ratio of the ridges are effective for the frictional resistance with the fingertips and the resistance during wiping. In these test numbers, the surface roughness and area ratio of the ridges were not in an appropriate range, so that sebum was easily collected and the ease of wiping off fingerprints was impaired.

  Further, among them, test number 47 had a low fingerprint resistance evaluation and a low color tone evaluation. In this test number, the fact that the area ratio of the flat part of the ridge is larger than the range described in the present invention (1) means that the dent part provided with the coloring layer is greatly shaved. This is because the color tone has changed from the developed state of.

  In test numbers 48 and 52, the evaluation of scratch resistance was low. In Test No. 48, the surface hardness was lower than the lower limit described in the present invention (1), so that wrinkles were easily formed and the tackiness was clearly poor. On the other hand, in order to evaluate the scratch resistance in the test number 52, a part of the surface layer was dropped while being carried in a bag together with the coin for half a year. Could not be evaluated. This is because the surface layer is too hard and brittle and breaks when it comes into strong contact with the coin.

  Regarding the color development on the surface, it was confirmed that in both the present invention example and the comparative example, the dent portion was colored and the convex portion was removed.

  The color titanium material subjected to the treatment of the present invention is used for interior and exterior materials for buildings, kitchen materials, furniture, furniture, exteriors of electrical equipment, electronic equipment casings, accessories, ornaments, interior materials for automobiles, etc. , Especially can be utilized.

Claims (2)

The surface is colored by anodization, and has an equivalent circle diameter with an average diameter of 20 to 150 μm and an average depth of 3 to 30 μm from adjacent convex portions (ridges) on the surface, and adjacent to the surface. The color of the convex portion (ridge) is removed, the surface roughness is a smooth flat portion with a surface roughness Ra of 0.10 to 1.50 μm, and the area ratio of the flat portion is 10 to 60% of the whole In addition, the maximum hardness at a depth of 50 μm from the outermost surface is 40 to 150 points higher than the base material in terms of Vickers hardness (Hv 0.02). Color titanium products that are difficult and have excellent design. 2. The color titanium product according to claim 1, wherein the color titanium product is one of a container, an electronic device casing, a building, or a member thereof having excellent design properties .