Agent for improving fingerprint resistance of film and method for improving fingerprint resistance of film

Abstract

The present invention newly provides an anti-fingerprint agent for coatings and a method for improving the anti-fingerprint properties of a coating.　This anti-fingerprint agent is for coatings which are anodized aluminum or aluminum-alloy coatings, the anti-fingerprint agent containing a phosphorus-containing chelating agent. The anti-fingerprint agent is for use in a pore-filling treatment and / or a dye fixation treatment of a coating.

Description

[Technical Field]

[0001] The present invention relates to an agent for improving the fingerprint resistance of a film and a method for improving the fingerprint resistance of a film. [Background technology]

[0002] Anodized films on aluminum alloys are generally subjected to a sealing treatment to prevent staining, improve corrosion resistance, etc. Sealing methods include boiling water sealing, steam sealing, room temperature sealing, and nickel acetate sealing, which involves sealing using an aqueous nickel acetate solution.

[0003] Conventional boiling water sealing is prone to producing a defect in appearance known as powdering, which can impair the design of the treated product. Conventional nickel acetate sealing is prone to fingerprints (oil) adhering to the surface, particularly in black-dyed products, which can impair the design of the treated product.

[0004] US Patent No. 5,999,949 discloses a method for impregnating anodically formed surfaces of aluminum and / or aluminum alloys, in which the colored or uncolored surface is contacted with an aqueous solution containing an anionic surface-active compound containing at least one sulfonic acid group, phosphonic acid group and / or phosphonous acid group.

[0005] Patent Document 2 discloses a method for post-sealing an anodized metal surface, which comprises contacting the anodized metal with an aqueous solution, (a) a cationic, anionic, or nonionic surfactant, and (b) an organic acid, such as a cyclic polycarboxylic acid and / or a phosphonic acid.

[0006] Patent Document 3, developed by the present applicant, discloses a sealing solution for anodized coatings on aluminum alloys, which contains a thickening polysaccharide. Use of this sealing solution can impart good sealing performance to anodized coatings on aluminum alloys, as well as excellent stain resistance, dye fixation, and dye appearance.

[0007] Patent Document 4, a technology developed by the present applicant, discloses a lightfastness improver for a film, the film being an anodized film of dyed aluminum or aluminum alloy, and the lightfastness improver contains a phosphorus-based compound such as phosphoric acids, phosphates, or a phosphorus-containing chelating agent. The use of this lightfastness improver can improve the lightfastness of the film as a surface treatment for the film. By performing a sealing treatment after the surface treatment, discoloration of the film after the sealing treatment when exposed to light is suppressed, thereby achieving excellent lightfastness. Articles obtained using this lightfastness improver exhibit excellent lightfastness by suppressing discoloration of the film when exposed to light. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Published Patent Gazette No. 04-502647 [Patent Document 2] Published Patent Publication No. 2000-511972 [Patent Document 3] International Publication No. WO2020 / 080009A1 [Patent Document 4] International Publication No. WO2022 / 186320A1 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a novel agent for improving the fingerprint resistance of a film and a method for improving the fingerprint resistance of a film. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to achieve the above-mentioned object, and as a result have found that the use of a surface treatment agent containing a chelating agent having phosphorus in its structure can effectively improve anti-fingerprint performance, which has led to the completion of the present invention.

[0011] That is, the present invention relates to the following technology for improving anti-fingerprint performance. 1. An agent for improving the anti-fingerprint properties of a coating, the coating is an anodized coating of aluminum or an aluminum alloy, containing a phosphorus-containing chelating agent, A fingerprint resistance improving agent used in the sealing treatment and / or dye fixing treatment of the coating. 2. The anti-fingerprint agent according to item 1, wherein the phosphorus-containing chelating agent is at least one chelating agent selected from the group consisting of organic chelating agents. 3. The phosphorus-containing chelating agent is selected from the group consisting of hydroxyethylidene diphosphonic acid and its salts, nitrilotrismethylenephosphonic acid (NTMP) and its salts, phosphonobutanetricarboxylic acid (PBTC) and its salts, ethylenediaminetetramethylenephosphonic acid (EDTMP) and its salts, diethylenetriaminepentamethylenephosphonic acid (DETPMP) and its salts, hexamethylenediaminetetramethylenephosphonic acid (HMDTMP) and its salts, vinylphosphonic acid and its salts, phenylphosphonic acid and its salts, β-glycerophosphoric acid and its salts, DL-2-aminophosphonobutyric acid and its salts, diphenyl Item 3. The anti-fingerprint improver according to Item 1 or 2, which is at least one chelating agent selected from the group consisting of phosphonic acid and its salts, aminomethylphosphonic acid (AMP) and its salts, polyaminopolyethermethylenephosphonic acid (PAPEMP) and its salts, bishexamethylenetriaminepentamethylenephosphonic acid (BHMTMP) and its salts, nitrilotrismethylenetrisphosphonic acid N-oxide (ATMP-NO) and its salts, phosphonoformic acid and its salts, polymaleic acid phosphonate and its salts, hydroxyphosphonoacetic acid and its salts, and ethanolaminebismethylenephosphonic acid and its salts. 4. The anti-fingerprint agent according to any one of items 1 to 3, wherein the content of the phosphorus-containing chelating agent in the anti-fingerprint agent is 0.1 mg / L or more and 1 g / L or less. 5. The anti-fingerprint agent according to any one of items 1 to 4, wherein the anti-fingerprint agent has a pH of 2 or more and 9 or less. 6. The anti-fingerprint agent according to any one of items 1 to 5, wherein the coating is a coating having holes and / or a dyed coating. 7. A method for improving the fingerprint resistance of a coating, comprising: the coating is an anodized coating of aluminum or an aluminum alloy, (1) A step of immersing the film in a fingerprint-resistant improving agent containing a phosphorus-containing chelating agent to perform a sealing treatment and / or a dye fixing treatment on the film. A method comprising: 8. The method according to Item 7, wherein the phosphorus-containing chelating agent is at least one chelating agent selected from the group consisting of organic chelating agents. 9. The phosphorus-containing chelating agent is selected from the group consisting of hydroxyethylidene diphosphonic acid and its salts, nitrilotrismethylenephosphonic acid (NTMP) and its salts, phosphonobutanetricarboxylic acid (PBTC) and its salts, ethylenediaminetetramethylenephosphonic acid (EDTMP) and its salts, diethylenetriaminepentamethylenephosphonic acid (DETPMP) and its salts, hexamethylenediaminetetramethylenephosphonic acid (HMDTMP) and its salts, vinylphosphonic acid and its salts, phenylphosphonic acid and its salts, β-glycerophosphoric acid and its salts, DL-2-aminophosphonobutyric acid and its salts, diphenyl ... Item 9. The method according to Item 7 or 8, wherein the chelating agent is at least one selected from the group consisting of hydroxylphosphonic acid and its salts, aminomethylphosphonic acid (AMP) and its salts, polyaminopolyethermethylenephosphonic acid (PAPEMP) and its salts, bishexamethylenetriaminepentamethylenephosphonic acid (BHMTMP) and its salts, nitrilotrismethylenetrisphosphonic acid N-oxide (ATMP-NO) and its salts, phosphonoformic acid and its salts, polymaleic acid phosphonate and its salts, hydroxyphosphonoacetic acid and its salts, and ethanolaminebismethylenephosphonic acid and its salts. 10. The method according to any one of items 7 to 9, wherein the content of the phosphorus-containing chelating agent in the anti-fingerprint agent is 0.1 mg / L or more and 1 g / L or less. 11. The method according to any one of items 7 to 10, wherein the pH of the anti-fingerprint agent for improving the anti-fingerprint property is 2 or more and 9 or less. 12. The method according to any one of items 7 to 11, wherein the coating is a porous coating and / or a dyed coating. 13. The method according to any one of items 7 to 12, wherein the step (1) is carried out by adjusting the liquid temperature of the anti-fingerprint agent to a temperature range of 80° C. or higher. 14. An article using the fingerprint resistance improving agent according to any one of items 1 to 6. 15. An article manufactured by the method according to any one of items 7 to 13.

[0012] The fingerprint resistance improver for a film of the present invention contains a chelating agent having phosphorus in its structure, and by using this fingerprint resistance improver (surface treatment agent) (a method for improving the fingerprint resistance of a film), it is possible to effectively improve the fingerprint resistance performance of an anodized film of aluminum or an aluminum alloy, and at the same time, it is possible to improve the appearance of the dyed film. [Effects of the Invention]

[0013] The present invention can provide a novel agent for improving the fingerprint resistance of a film and a method for improving the fingerprint resistance of a film. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below.

[0015] [1] Anti-fingerprint agent for coating The fingerprint resistance improver of the coating of the present invention (also referred to as "fingerprint resistance improver") is the coating is an anodized coating of aluminum or an aluminum alloy, containing a phosphorus-containing chelating agent, This is an anti-fingerprint agent used in the sealing treatment and / or dye fixing treatment of the coating.

[0016] The anti-fingerprint agent can improve the anti-fingerprint property of the coating.

[0017] (1-1) Anodic oxide coating of aluminum or aluminum alloy The substrate on which the anodized coating is formed is preferably made of aluminum or an aluminum alloy, and the aluminum used may be any of a variety of aluminum-based alloys, such as wrought alloys designated by JIS-A numbers in the 1000s to 7000s, cast materials designated by AC and ADC numbers, and die-cast materials.

[0018] The coating is an anodized coating of aluminum or an aluminum alloy. The coating may be a porous coating (a coating that has been subjected to a pore-sealing treatment) or a dyed coating.

[0019] The anti-fingerprint improver includes a phosphorus-containing chelating agent. The use of the anti-fingerprint improver can improve the anti-fingerprint performance of the film as a surface treatment of the film. The use of the anti-fingerprint improver can also impart an excellent color appearance to the film.

[0020] The anti-fingerprint improving agent is used in the sealing treatment of the coating. By performing the sealing treatment of the coating using the anti-fingerprint improving agent, it is possible to impart excellent anti-fingerprint performance to the coating, and additionally, an excellent color appearance. An article having such a coating has excellent anti-fingerprint performance, and additionally, an excellent color appearance.

[0021] The dyeing is preferably performed using an organic dye. The organic dye is preferably an azo-based, metal complex azo-based, anthraquinone-based, phthalocyanine-based, xanthene-based, or quinoline-based organic dye. Use of the fingerprint resistance improver can improve the dyed appearance of light metals such as aluminum and aluminum alloys, and coatings such as anodized coatings that have been dyed with a dye, and can maintain the design properties.

[0022] The anti-fingerprint agent is used in the dye fixing treatment of a film. By using the anti-fingerprint agent to perform the dye fixing treatment of a film, it is possible to impart excellent anti-fingerprint performance to the film and, additionally, excellent dye appearance. An article having such a film has excellent anti-fingerprint performance and, additionally, excellent dye appearance.

[0023] (1-2) Phosphorus-containing chelating agents The anti-fingerprint agent for a coating of the present invention contains a phosphorus-containing chelating agent, which is preferably at least one chelating agent selected from the group consisting of organic chelating agents because of its advantage of improving the anti-fingerprint performance of the coating.

[0024] The organic phosphorus-containing chelating agent is preferably hydroxyethylidene diphosphonic acid and its salts, nitrilotrismethylenephosphonic acid (NTMP) and its salts, phosphonobutanetricarboxylic acid (PBTC) and its salts, ethylenediaminetetramethylenephosphonic acid (EDTMP) and its salts, diethylenetriaminepentamethylenephosphonic acid (DETPMP) and its salts, hexamethylenediaminetetramethylenephosphonic acid (HMDTMP) and its salts, vinylphosphonic acid and its salts, phenylphosphonic acid and its salts, β-glycerophosphoric acid and its salts, D These include L-2-aminophosphonobutyric acid and its salts, diphenylphosphonic acid and its salts, aminomethylphosphonic acid (AMP) and its salts, polyaminopolyethermethylenephosphonic acid (PAPEMP) and its salts, bishexamethylenetriaminepentamethylenephosphonic acid (BHMTMP) and its salts, nitrilotrismethylenetrisphosphonic acid N-oxide (ATMP-NO) and its salts, phosphonoformic acid and its salts, polymaleic acid phosphonate and its salts, hydroxyphosphonoacetic acid and its salts, and ethanolaminebismethylenephosphonic acid and its salts.

[0025] The salt of the organic phosphorus-containing chelating agent is at least one salt selected from the group consisting of lithium salt, sodium salt, potassium salt, ammonium salt, alkaline earth metal salt, and metal salt.

[0026] The phosphorus-containing chelating agent contained in the anti-fingerprint agent is preferably nitrilotrismethylenephosphonic acid (NTMP) and its salts (e.g., sodium salt), phosphonobutanetricarboxylic acid (PBTC) and its salts (e.g., sodium salt), ethylenediaminetetramethylenephosphonic acid (EDTMP) and its salts (e.g., sodium salt), diethylenetriaminepentamethylenephosphonic acid (DETPMP) and its salts (e.g., sodium salt), hexamethylene Diaminetetramethylenephosphonic acid (HMDTMP) and its salts (e.g., sodium salt), aminomethylenephosphonic acid (AMP) and its salts (e.g., sodium salt), polyaminopolyethermethylenephosphonic acid (PAPEMP) and its salts (e.g., sodium salt), bishexamethylenetriaminepentamethylenephosphonic acid (BHMTMP) and its salts (e.g., sodium salt), nitrilotrismethylenetrisphosphonic acid N-oxide (ATMP-NO) and its salts (e.g., sodium salt) are used.

[0027] The anti-fingerprint agent may be at least one phosphorus-based compound selected from the group consisting of phosphorus-containing chelating agents, and may be used singly or in the form of a mixture (blend) of two or more types.

[0028] Content of phosphorus-containing chelating agent The content of the phosphorus-containing chelating agent in the fingerprint resistance improving agent is preferably 0.1 mg / L to 1,000 mg / L (1 g / L), more preferably 0.5 mg / L to 200 mg / L, and even more preferably 1 mg / L to 100 mg / L. By adjusting the content of the phosphorus-containing chelating agent to preferably 0.1 mg / L to 1,000 mg / L, it is possible to impart good fingerprint resistance and a dyed appearance to the coating.

[0029] (1-3) pH The anti-fingerprint enhancer of the coating of the present invention is preferably an aqueous solution.

[0030] The pH of the anti-fingerprint agent for improving the film of the present invention is preferably about 2 or more and about 9 or less, more preferably about 3 or more and about 7 or less, and even more preferably about 3.5 or more and about 6.5 or less, from the viewpoint of improving the anti-fingerprint performance of the film.

[0031] By adjusting the ratio of the anti-fingerprint improver to about 2 or more and 9 or less, the anti-fingerprint improver exhibits sufficient sealing performance, and by using the anti-fingerprint improver to seal the film, it is possible to impart good anti-fingerprint performance and a dyed appearance to the film. By using the anti-fingerprint improver to seal the film, it is possible to suppress poor appearance (powdering, fogging) caused by powdery deposits on the surface.

[0032] A pH adjuster (pH buffer) is included as needed to adjust the pH of the anti-fingerprint improver. By including a pH adjuster, the anti-fingerprint improver can improve its sealing performance and the usability of its aqueous solution. Use of the anti-fingerprint improver can prevent a decrease in the sealing degree of the sealed anodized film.

[0033] The pH adjuster is not particularly limited. As the pH adjuster, preferably, acetic acid, sulfamic acid, sulfuric acid, nitric acid, organic sulfonic acid, or the like, or a diluted aqueous solution thereof is used. As the pH adjuster, more preferably, acetic acid or a diluted aqueous solution thereof is used because of its advantage of excellent pore-sealing performance.

[0034] The pH adjuster for adjusting the fingerprint resistance improver to the alkaline side is preferably ammonia water, a sodium hydroxide aqueous solution, a potassium hydroxide aqueous solution, etc. The pH adjuster is more preferably a sodium hydroxide aqueous solution because of its excellent pore-sealing performance.

[0035] The fingerprint resistance improving agent may be a pH adjuster, which may be used alone or in the form of a mixture (blend) of two or more kinds.

[0036] (1-4) Other ingredients The fingerprint resistance improver for the coating of the present invention contains additive components such as surfactants, antifungal agents, metal salts, etc. as needed, because it has the advantage of further improving fingerprint resistance during surface treatment. The additives preferably include antifungal agents such as benzoic acid and benzoates. The antifungal agent used is a commercially available antifungal agent, preferably "TAC Kabicoron-3" (manufactured by Okuno Pharmaceutical Industries Co., Ltd.).

[0037] [2] Methods for improving the anti-fingerprint properties of coatings The present invention encompasses subjecting a film to the following treatments in this order: (1) pretreatment, (2) anodizing, (3) dyeing, (4) dye fixing (immersion in a fingerprint resistance improver), and (5) sealing (immersion in a fingerprint resistance improver). The method for improving the fingerprint resistance of a film of the present invention involves immersing the film in a fingerprint resistance improver, (4) dye fixing, and / or (5) sealing.

[0038] [2-1] Preprocessing Before anodizing, the aluminum or aluminum alloy to be treated is pretreated to remove any deposits. The pretreatment method is preferably a known method such as solvent washing, acid washing, weak alkali washing, acid etching, alkali etching, desmutting, or chemical polishing, depending on the type of material and the state of the deposits.

[0039] [2-2] Anodizing An anodized film is formed on aluminum or an aluminum alloy. The anodizing treatment is preferably carried out by immersing the aluminum or aluminum alloy to be treated in an anodizing treatment solution.

[0040] The electrolyte used in the anodizing treatment is preferably an electrolyte such as a sulfuric acid aqueous solution, an oxalic acid aqueous solution, a chromic acid aqueous solution, a sulfonic acid aqueous solution, etc. The temperature of the electrolyte (treatment solution) is preferably about 0°C or higher and 80°C or lower, more preferably about 10°C or higher and 40°C or lower.

[0041] The electrolysis method may be either AC or DC, but DC electrolysis is preferably used because it allows rapid film growth and allows a thick film to be easily obtained.

[0042] The current density is preferably 0.1 A / dm 2 More than 10A / dm 2 It is preferably about 0.5A / dm or less. 2 More than 3 A / dm 2 The current application time is preferably about 10 minutes or more and 100 minutes or less.

[0043] The thickness of the film formed by anodization can be set arbitrarily depending on the application, and is preferably about 2 μm or more and 50 μm or less, and more preferably about 5 μm or more and 20 μm or less.

[0044] After anodizing aluminum or an aluminum alloy, the anodized film is subjected to a dye fixing treatment as needed, and then the method of the present invention for improving the fingerprint resistance of the film (immersion in a fingerprint resistance improving agent, sealing treatment) is applied.

[0045] The coating may be an anodized coating that has been electrolytically colored. The electrolytic coloring method involves immersing an anodized aluminum or aluminum alloy coating that has been anodized in an electrolytic coloring bath, followed by secondary electrolysis. The electrolytic coloring bath is preferably a nickel salt-boric acid bath, a nickel salt-tin salt-sulfuric acid bath, or the like.

[0046] [2-3] Dyeing process The anodized coating of aluminum or aluminum alloy may be a coating having pores (a coating that is subjected to a pore-sealing treatment) or may be a dyed coating. The dyeing treatment dyes the anodized coating of aluminum or aluminum alloy. The dyeing treatment preferably uses coloring with a dye.

[0047] For dye coloring, a method of immersing the anodized film in an aqueous dye solution is preferably used. The dye is preferably a commercially available dye for anodized films of aluminum or aluminum alloys, more preferably an anionic dye. For dyeing, an aqueous solution containing the dye (e.g., a dye bath or dye solution) is preferably used.

[0048] The temperature of the aqueous solution containing the dye is preferably adjusted to 10°C or higher and 70°C or lower, more preferably 20°C or higher and 60°C or lower.

[0049] The concentration of the dye in the aqueous solution containing the dye and the immersion time are appropriately determined depending on the desired color tone and color depth of the dye.

[0050] [2-4] Dye fixing treatment The dye in the dyed film is fixed. The treatment liquid for fixing the dye in the film (dye fixing treatment liquid) preferably uses the fingerprint resistance improver for the film containing the phosphorus-containing chelating agent [1] of the present invention. The fingerprint resistance improver for the film of the present invention is also useful in the dye fixing treatment.

[0051] The method of improving the fingerprint resistance of the film of the present invention involves immersing the film in a fingerprint resistance improving agent and performing a dye fixing treatment.

[0052] How to improve the fingerprint resistance of coatings (dye fixing treatment) The method for improving the fingerprint resistance of the coating of the present invention (also referred to as "method for improving fingerprint resistance") is as follows: the coating is an anodized coating of aluminum or an aluminum alloy, (1) The method includes a step of immersing the film in a fingerprint resistance improving agent containing a phosphorus-containing chelating agent to perform a dye fixing treatment on the film.

[0053] The dye fixing treatment involves immersing the dyed anodized film in a dye fixing treatment solution to fix the dye in the dyed film. By using the agent for improving fingerprint resistance for films containing the phosphorus-containing chelating agent of the present invention in the dye fixing treatment solution, it is possible to impart good dye fixing properties to the anodized film of an aluminum alloy.

[0054] Dye fixing solution temperature The liquid temperature for the dye fixing treatment (the bath temperature of the dye fixing treatment liquid) is preferably about 80°C or higher and 98°C or lower, more preferably about 92°C or higher and 98°C or lower, and even more preferably about 95°C or higher and 98°C or lower. By adjusting the temperature for the dye fixing treatment, it is possible to impart good dye fixing properties to the coating. Furthermore, even if the liquid temperature for the dye fixing treatment exceeds 98°C, the fingerprint resistance effect becomes saturated, and therefore, a temperature of 98°C or lower is preferred in terms of further improving energy efficiency.

[0055] pH of dye fixing solution The pH of the dye fixing treatment solution is preferably about 2 or more and about 6 or less, more preferably about 2.5 or more and about 5 or less, and even more preferably about 3 or more and about 4.5 or less. By adjusting the pH of the dye fixing treatment solution, it is possible to impart good dye fixing properties to the anodized film of the aluminum alloy. The pH of the dye fixing treatment solution is adjusted to be slightly more acidic than that of the sealing treatment solution, in order to achieve the advantage of imparting good dye fixing properties.

[0056] Dye fixing process time The time for dye fixing treatment is usually determined depending on the thickness of the anodized film to be treated, and is preferably adjusted to a time of about 3 minutes or more and 60 minutes or less.

[0057] [2-5] Sealing treatment The film (which may be a dyed film) is subjected to a sealing treatment. The treatment liquid (sealing treatment liquid) used to seal the film is preferably the agent for improving fingerprint resistance of the present invention, which contains the phosphorus-containing chelating agent [1]. The agent for improving fingerprint resistance of the present invention is also useful in the sealing treatment.

[0058] The method of the present invention for improving the fingerprint resistance of the film is to immerse the film in an agent for improving fingerprint resistance and to perform a sealing treatment.

[0059] How to improve the anti-fingerprint properties of coatings (sealing treatment) The method for improving the fingerprint resistance of the coating of the present invention (also referred to as "method for improving fingerprint resistance") is as follows: the coating is an anodized coating of aluminum or an aluminum alloy, (1) The method includes a step of immersing the film in an anti-fingerprint agent containing a phosphorus-containing chelating agent to perform a sealing treatment on the film.

[0060] The aluminum or aluminum alloy anodized film, phosphorus-containing chelating agent, pH, and other components to be used in the method for improving fingerprint resistance are the same as those described above in [1] Fingerprint resistance improver for film.

[0061] By using the anti-fingerprint improver of the present invention to perform a sealing treatment on a film, it is possible to effectively improve the anti-fingerprint property of the film and also to impart sealing performance.By using the anti-fingerprint improver of the present invention to perform a sealing treatment on a film, it is possible to impart excellent stain resistance, dye fixation properties, and excellent dye appearance to an anodized film of an aluminum alloy.

[0062] Sealing treatment liquid temperature The liquid temperature for the sealing treatment (bath temperature of the sealing treatment liquid) is preferably about 80°C or higher and 98°C or lower, more preferably about 92°C or higher and 98°C or lower, and even more preferably about 95°C or higher and 98°C or lower. This allows for good sealing performance to be imparted to the coating. Furthermore, even if the liquid temperature for the sealing treatment exceeds 98°C, the fingerprint resistance effect becomes saturated, and a temperature of 98°C or lower is preferred in terms of further improving energy efficiency.

[0063] pH of sealing solution The pH of the sealing treatment liquid is preferably about 2 or more and about 9 or less, more preferably about 3.0 or more and about 7.0 or less, and even more preferably about 3.5 or more and about 6.5 or less. By adjusting the pH of the sealing treatment liquid, the sealing treatment liquid can exhibit sufficient sealing performance and also suppress poor appearance (powdering, fogging) caused by powdery deposits adhering to the surface of the treated object.

[0064] Sealing time The time for the sealing treatment is usually determined depending on the thickness of the anodized film to be treated, and is preferably adjusted to a time of about 3 minutes to 1 hour.

[0065] The sealing treatment time (minutes) is determined by multiplying the thickness (μm) of the anodized coating to be treated by preferably a number equal to or greater than 0.1 and equal to or less than 10, more preferably a number equal to or greater than 0.2 and equal to or less than 5, and even more preferably a number equal to or greater than 0.5 and equal to or less than 4. For example, when the thickness of the anodized coating is to be about 10 μm, the immersion time is more preferably determined by multiplying 10 (μm) by a number equal to or greater than 0.2 and equal to or less than 5, which is about 2 to 50 minutes.

[0066] By adjusting the sealing treatment time, the sealing treatment liquid can exhibit sufficient sealing performance, and the film sealed with the sealing treatment liquid can exhibit sufficient fingerprint resistance performance, and at the same time, deterioration of the appearance of the treated object due to appearance defects such as powdering and fogging can be suppressed.

[0067] Sealing method The sealing treatment involves immersing an article (subject to be treated) having a coating in a sealing treatment solution (an agent for improving the fingerprint resistance of the coating). The article having a coating may be an article that has been subjected to electrolytic coloring, dyeing, etc. The sealing treatment can greatly improve the sealing performance of the coating on the subject to be treated.

[0068] The immersion for the sealing treatment is preferably performed by immersing the article having the coating in the sealing treatment solution while stirring the solution. The stirring method is preferably circulation stirring, air stirring, gas stirring, or rocking stirring, more preferably circulation stirring or gas stirring, and even more preferably circulation stirring.

[0069] The gas for gas agitation is preferably an inert gas such as nitrogen gas, argon gas, etc. When air agitation is performed, it is preferable to perform gas agitation using an inert gas, which can prevent the sealing treatment solution from becoming cloudy.

[0070] Turbidity removal treatment The turbidity removal treatment removes turbidity from the sealing treatment solution. The turbidity removal treatment is preferably carried out during a standby period before immersing an article in the sealing treatment solution or during a period when the sealing treatment line is stopped. By removing the turbidity from the sealing treatment solution, it is possible to suppress poor appearance of the coating, such as powdering and fogging, which are caused by turbidity.

[0071] The method for removing turbidity from the sealing solution is preferably filtration. A portion of the sealing solution is removed from the sealing tank, and then part of the sealing solution is poured into a reserve tank such as a cushion tank, which is a chemical supply and dissolution tank. The temperature of the sealing solution is preferably cooled to below 50°C, and the sealing solution is filtered through a filter and returned to the sealing tank for circulation. If the facility does not have a cushion tank, the sealing solution may be filtered and removed by simple filtration circulation.

[0072] Combination of dye fixing treatment and sealing treatment First, a dye fixing treatment may be performed using a dye fixing treatment liquid containing the fingerprint resistance improver for a film that contains the phosphorus-containing chelating agent of the present invention, and then a sealing treatment may be performed using a sealing treatment liquid containing the fingerprint resistance improver for a film that contains the phosphorus-containing chelating agent of the present invention.

[0073] The dye fixing treatment and the sealing treatment may be performed as a single treatment, i.e., a single treatment. The dye fixing treatment solution may use the agent for improving fingerprint resistance of a film containing a phosphorus-containing chelating agent of the present invention, and the sealing treatment solution may use the agent for improving fingerprint resistance of a film containing a phosphorus-containing chelating agent of the present invention, and the dye fixing treatment and the sealing treatment may be performed as a single treatment by preparing the same treatment solution.

[0074] When the sealing treatment solution uses the agent for improving fingerprint resistance of a film containing a phosphorus-containing chelating agent of the present invention, the dye fixing treatment may use a commonly available dye fixing solution, such as TAC Fixer-2 or TAC Sunblock 77-5C manufactured by Okuno Chemical Industries Co., Ltd., which are commercially available for use in the dyeing process of anodized aluminum alloy films.

[0075] When the dye fixing solution contains the agent for improving fingerprint resistance of a film containing a phosphorus-containing chelating agent of the present invention, the sealing solution may be a commonly available sealing solution, such as Top Seal NIF or Top NF Seal S-205 manufactured by Okuno Chemical Industries Co., Ltd., which are commercially available for use in the dyeing process of anodized aluminum alloy films.

[0076] [3] Concentrate liquid The present invention encompasses a concentrated solution of the agent for improving fingerprint resistance of the coating of the present invention (sealing treatment solution and / or dye fixing treatment solution).

[0077] By preparing the anti-fingerprint agent as a concentrated solution containing high concentrations of the components contained in the anti-fingerprint agent, the anti-fingerprint agent can be easily transported and stored.The anti-fingerprint agent can be easily prepared by diluting the concentrated solution with a diluent such as water.

[0078] [4] Goods The present invention encompasses articles obtained by applying the method of improving the anti-fingerprint properties of the coating of the present invention (sealing treatment and / or dye fixing treatment). In other words, the present invention also encompasses articles produced by the method of improving the anti-fingerprint properties of the coating of the present invention.

[0079] The uses of the articles are preferably exteriors of electronic devices, exteriors of cosmetic products, automobile-related parts, railway-related parts, aircraft-related parts, ship-related parts, household electrical appliance parts, housing equipment parts, office automation equipment parts, play equipment parts, eyeglass parts, etc.

[0080] The coating of an article exhibits excellent anti-fingerprint performance by applying the anti-fingerprint agent of the present invention to the coating. Such an article using the anti-fingerprint agent of the present invention also constitutes one aspect of the present invention. [Example]

[0081] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0082] [1] Preparation of anodized aluminum alloy test specimens Anodized aluminum alloy test pieces (anodized test pieces) were prepared.

[0083] (1-1) Degreasing treatment The aluminum test pieces were made of JIS A1050P plate material. The weak alkaline degreasing solution used was a 30 g / L aqueous solution of Top Alclean 101 (EDCM) (trade name) manufactured by Okuno Chemical Industries Co., Ltd. The bath temperature of the weak alkaline degreasing solution was set to 60°C. The aluminum test pieces were immersed in the weak alkaline degreasing solution (60°C) for 3 minutes to be degreased.

[0084] (1-2) Anodizing The anodizing bath contains 180 g / L of free sulfuric acid and 8 g / L of dissolved aluminum. The anodizing conditions are bath temperature: 20 ± 1 °C, anodic current density: 1 A / dm 2 The electrolysis time was 30 minutes. The degreased aluminum test piece was washed with water and anodized using an anodizing bath containing sulfuric acid as the main component. An anodized film was formed with a film thickness of approximately 10 μm. The resulting anodized film was washed with water.

[0085] (1-3) Dyeing treatment The dyeing treatment solution used was a 5 g / L solution of TAC dye TAC BLACK-GLH (402) manufactured by Okuno Chemical Industries Co., Ltd. The anodized film was immersed in the dyeing treatment solution (50°C) for 1 minute to dye it. The resulting dyed anodized film (anodized test piece) was then rinsed with water.

[0086] [2] Dye fixing treatment and sealing treatment The anodized test pieces were subjected to a dye fixing treatment under the dye fixing treatment conditions and a sealing treatment under the sealing treatment conditions shown in Tables 1 to 4 to prepare samples of Examples 1 to 78 and Comparative Examples 1 to 3. After the dye fixing treatment and sealing treatment were performed on the anodized test pieces, they were rinsed with running tap water for 1 minute. Specifically, the procedure is as follows.

[0087] In Example 1, a fingerprint-resistant improver (pH = 5.5) containing AMP (a phosphorus-containing chelating agent, 50 mg / L) was used for the sealing treatment (sealing treatment temperature: 95°C, sealing treatment time: 30 minutes). In Examples 2 to 9, the phosphorus-containing chelating agent contained in the fingerprint-resistant improver used for the sealing treatment was changed to PAPEMP in Example 2, PBTC in Example 3, DETPMP in Example 4, NTMP in Example 5, EDTMP in Example 6, HMDTMP in Example 7, BHMTMP in Example 8, and ATMP-NO in Example 9. In Example 10, a mixture of nickel acetate tetrahydrate and AMP was used.

[0088] In Example 11, an AMP-containing fingerprint resistance improver (pH = 4.0) was used in the dye fixing treatment, and an AMP-containing fingerprint resistance improver (pH = 5.5) was used in the sealing treatment. In Examples 12 to 19, the phosphorus-containing chelating agent contained in the fingerprint resistance improver used in the dye fixing treatment and the phosphorus-containing chelating agent contained in the fingerprint resistance improver used in the sealing treatment were changed to Example 12: PAPEMP-PAPEMP, Example 13: PBTC-PBTC, Example 14: DETPMP-DETPMP, Example 15: NTPM-NTPM, Example 16: EDTMP-EDTMP, Example 17: HMDTMP-HMDTMP, Example 18: BHMTMP-BHMTMP, and Example 19: ATMP-NO-ATMP-NO.

[0089] In Example 20, TAC fixing agent-2 was used for the dye fixing treatment, and an anti-fingerprint improver containing AMP was used for the sealing treatment. In Example 21, an anti-fingerprint improver containing AMP was used for the dye fixing treatment, and Top NF Seal S-205 was used for the sealing treatment.

[0090] In Comparative Example 1, phosphoric acid was used for the sealing treatment (sealing temperature: 95°C, sealing time: 30 minutes). In Comparative Example 2, phosphoric acid was used for the dye fixing treatment, and Top NF Seal S-205 was used for the sealing treatment.

[0091] In Example 22, an anti-fingerprint improver containing AMP (0.1 mg / L, pH = 5.5) was used for the sealing treatment. In Examples 23 to 32, the content of the phosphorus-containing chelating agent contained in the anti-fingerprint improver used for the sealing treatment was changed as follows: Example 23: AMP 0.4 mg / L, Example 24: AMP 0.5 mg / L, Example 25: AMP 0.8 mg / L, Example 26: AMP 1 mg / L, Example 27: AMP 10 mg / L, Example 28: AMP 100 mg / L, Example 29: AMP 120 mg / L, Example 30: AMP 200 mg / L, Example 31: AMP 250 mg / L, Example 32: AMP 1000 mg / L.

[0092] In Comparative Example 3, the anodized test piece was immersed in boiling water (bath temperature 95° C.) with a pH of 6.0 for 30 minutes to perform a sealing treatment.

[0093] In Example 33, a fingerprint resistance improver containing AMP (0.1 mg / L, pH = 4.0) was used in the dye fixing treatment, and the anodized test piece was immersed in boiling water (bath temperature 95 ° C.) with a pH of 6.0 for 30 minutes to perform a sealing treatment. In Examples 34 to 43, the content of the phosphorus-containing chelating agent contained in the fingerprint resistance improver used in the dye fixing treatment was changed to: Example 34: AMP 0.4 mg / L, Example 35: AMP 0.5 mg / L, Example 36: AMP 0.8 mg / L, Example 37: AMP 1 mg / L, Example 38: AMP 10 mg / L, Example 39: AMP 100 mg / L, Example 40: AMP 120 mg / L, Example 41: AMP 200 mg / L, Example 42: AMP 250 mg / L, and Example 43: AMP 1000 mg / L.

[0094] In Example 44, an anti-fingerprint agent containing AMP (50 mg / L, pH = 2.0) was used for the sealing treatment. In Examples 45 to 55, the pH of the sealing treatment solution was changed as follows: Example 45: pH = 2.8, Example 46: pH = 3.0, Example 47: pH = 3.3, Example 48: pH = 3.5, Example 49: pH = 5.0, Example 50: pH = 6.5, Example 51: pH = 6.7, Example 52: pH = 7.0, Example 53: pH = 7.5, Example 54: pH = 8.0, and Example 55: pH = 9.0.

[0095] In Example 56, a fingerprint resistance improver containing AMP (50 mg / L, pH = 2.0) was used in the dye fixing treatment, and the anodized test piece was immersed in boiling water (bath temperature 95°C) with a pH of 6.0 for 30 minutes to perform a sealing treatment. In Examples 57 to 66, the pH of the dye fixing treatment solution was changed as follows: Example 57: pH = 2.3, Example 58: pH = 2.5, Example 59: pH = 2.8, Example 60: pH = 3.0, Example 61: pH = 4.0, Example 62: pH = 4.5, Example 63: pH = 4.7, Example 64: pH = 5.0, Example 65: pH = 5.5, and Example 66: pH = 6.0.

[0096] In Example 67, a fingerprint resistance improver (pH = 5.5) containing AMP (a phosphorus-containing chelating agent, 50 mg / L) was used for the sealing treatment (sealing treatment temperature: 80°C, sealing treatment time: 30 minutes). In Examples 68 to 72, the sealing treatment temperature was changed to 90°C in Example 68, 92°C in Example 69, 94°C in Example 70, 95°C in Example 71, and 98°C in Example 72.

[0097] In Example 73, a dye fixing treatment (treatment temperature: 80°C, treatment time: 5 minutes) was performed using an AMP-containing anti-fingerprint improver (50 mg / L, pH = 4.0), and the anodized test piece was then immersed in boiling water (bath temperature 95°C) with a pH of 6.0 for 30 minutes to perform a sealing treatment. In Examples 74 to 78, the treatment temperature of the dye fixing treatment was changed to Example 74: 90°C, Example 75: 92°C, Example 76: 94°C, Example 77: 95°C, and Example 78: 98°C.

[0098] The anodized test piece that had been subjected to the dye fixing treatment and the pore sealing treatment was dried in a dryer and then left overnight in a room temperature environment to prepare an anodized test piece (test piece for evaluation) that had been subjected to the dye fixing treatment and the pore sealing treatment.

[0099] [3] Evaluation test The anodized test pieces (test pieces for evaluation) that had been subjected to dye fixing treatment and sealing treatment were evaluated according to the following evaluation methods.

[0100] (3-1) Appearance evaluation The evaluation test pieces were visually inspected for powdering, fogging, or the occurrence of interference film rainbows due to these on the surface.

[0101] Evaluation criteria ++: The surface of the test piece is completely free of powdering, fogging, or interference film rainbows resulting from these, and has a good appearance. +: Powdering, fogging, or interference film rainbows due to these have occurred slightly on the surface of the test piece, but to a degree that does not cause any practical problems. -: Powdering, fogging, or interference film rainbows caused by these are strongly observed on the surface of the test piece, resulting in severe appearance defects.

[0102] In the evaluation, a rating of + or higher can be considered to be a good appearance for practical use.

[0103] (3-2) Fingerprint resistance Artificial fingerprint liquid (dirt components) was applied to the pad of a thumb that had been degreased with ethanol, and the excess was wiped off with a rag. The pad of the thumb was pressed against the evaluation test piece to leave a fingerprint. The L* value of the evaluation test piece was measured using a spectrophotometer CA-3700A (manufactured by Konica Minolta, Inc.). The color difference in brightness (ΔL*) of the test piece before and after the fingerprint was left on it was measured.

[0104] Evaluation criteria +++: The color difference ΔL* of the lightness of the test piece is less than 0.5. ++: The color difference ΔL* of the lightness of the test piece is 0.5 or more and less than 1.0. +: The color difference ΔL* of the lightness of the test piece is 1.0 or more and less than 1.5. -: The color difference ΔL* of the test piece's brightness is 1.5 or more.

[0105] In the evaluation of fingerprint resistance of the test piece, if the test piece is rated + or higher, it can be evaluated as having good fingerprint resistance in actual use.

[0106] (3-3) Dye fixation The L*, a*, and b* values ​​of the evaluation test pieces were measured using a spectrophotometer CA-3700A (manufactured by Konica Minolta, Inc.). The reference color was the color tone after the dyeing treatment (L*1, a*1, b*1). The comparison color was the color tone after the sealing treatment (L*2, a*2, b*2). The color tones (L*, a*, b*) of the evaluation test pieces were measured, and the color difference (ΔE*ab) was calculated from these values. Color difference (ΔE*ab) Reference color: Color tone after dyeing process (L*1, a*1, b*1) Comparison color: Color tone after sealing treatment (L*2, a*2, b*2)

[0107] The formula for calculating the color difference is shown below. [ka]

[0108] Evaluation criteria +++: The color difference ΔE*ab of the test piece is less than 1.0. ++: The color difference ΔE*ab of the test piece is 1.0 or more and less than 2.0. +: The color difference ΔE*ab of the test piece is 2.0 or more and less than 4.0. -: The color difference ΔE*ab of the test piece is 4.0 or more.

[0109] In the evaluation of dye fixation of the test piece, if the test piece is rated + or higher, it can be evaluated that the dye is well fixed in actual use.

[0110] (3-4) Sealing degree In accordance with JIS H 8683-2:1999 (Test method for sealing degree of anodized film on aluminum and aluminum alloys, Part 2: Immersion test in phosphoric acid-chromic acid aqueous solution), the evaluation test piece after sealing treatment was immersed in a phosphoric acid-chromic acid aqueous solution, and the mass loss of the test piece per unit area was measured.

[0111] Evaluation criteria +++: Weight loss of test piece is 10.0 mg / dm 2 is less than. ++: Weight loss of test piece is 10.0 mg / dm 2 More than 15.0 mg / dm 2 is less than. +: Weight loss of test piece is 15.0 mg / dm 2 More than 20.0 mg / dm 2 is less than. -: Test piece weight loss is 20.0mg / dm 2 That's all.

[0112] In the evaluation of the sealing degree of the test piece, if the rating is + or higher, it can be evaluated as being well sealed in actual use.

[0113] [4] Explanation of terms in Table 1 The terms listed in Table 1 have the following meanings: Sealing: Sealing treatment was applied. Fixing → Sealing: First, the dye fixing treatment was carried out, and then the sealing treatment was carried out. AMP: aminomethylene phosphonic acid PAPEMP: Polyaminopolyether methylene phosphonic acid PBTC: Phosphonobutanetricarboxylic acid DETPMP: Diethylenetriaminepentamethylenephosphonic acid NTMP: Nitrilotrismethylenephosphonic acid EDTMP: ethylenediaminetetramethylenephosphonic acid HMDTMP: hexamethylenediaminetetramethylenephosphonic acid BHMTMP: Bishexamethylenetriaminepentamethylenephosphonic acid ATMP-NO: Nitrilotrismethylenetrisphosphonic acid N-oxide TAC Fixing Agent-2: Dye fixing solution manufactured by Okuno Chemical Industries Co., Ltd. Top Seal S-205: Sealing solution manufactured by Okuno Chemical Industries Co., Ltd.

[0114] The results are shown in Tables 1 to 4.

[0115] [Table 1]

[0116] [Table 2]

[0117] [Table 3]

[0118] [Table 4]

[0119] [5] Usefulness of anti-fingerprint agents for coatings As can be seen from Tables 1 to 4, the fingerprint resistance improver of the present invention, which contains a phosphorus-containing chelating agent and is used as a sealing treatment solution, can impart a good color appearance and fingerprint resistance to the anodized film of the aluminum alloy.

[0120] The fingerprint resistance improver of the present invention is useful in a sealing treatment (sealing treatment solution). By using the fingerprint resistance improver of the present invention to perform a sealing treatment on a film, the fingerprint resistance of the film can be favorably improved and sealing performance can also be imparted.

[0121] From Tables 1 to 4, it can be seen that the fingerprint resistance improver of the present invention contains a phosphorus-containing chelating agent, and by using this in a dye fixation treatment, it is possible to impart good dye fixation properties (dyed appearance) to the anodized film of an aluminum alloy.

[0122] The fingerprint resistance improver of the present invention is also useful in dye fixing treatment (dye fixing treatment solution). By subjecting a dyed film to dye fixing treatment using the fingerprint resistance improver for a film of the present invention, it is possible to impart good dye fixing properties to the film.

[0123] From Tables 1 to 4, it can be seen that the fingerprint resistance improver of the present invention contains a phosphorus-containing chelating agent, and by using this in the sealing treatment and / or dye fixation treatment, it is possible to effectively seal the anodized film of the aluminum alloy and also to impart good dye fixation properties (dyed appearance).

Claims

1. An anti-fingerprint improver for a coating, the coating is an anodized coating of aluminum or an aluminum alloy, containing a phosphorus-containing chelating agent, It is used for sealing the coating and / or dye fixing the coating, The pH when used for the sealing treatment is 2 or more and 9 or less, The pH when used in the dye fixing treatment is 2 or more and 6 or less. Anti-fingerprint improver.

2. 2. The anti-fingerprint agent according to claim 1, wherein the phosphorus-containing chelating agent is at least one chelating agent selected from the group consisting of organic chelating agents.

3. Examples of the phosphorus-containing chelating agent include hydroxyethylidene diphosphonic acid and its salts, nitrilotrismethylenephosphonic acid (NTMP) and its salts, phosphonobutanetricarboxylic acid (PBTC) and its salts, ethylenediaminetetramethylenephosphonic acid (EDTMP) and its salts, diethylenetriaminepentamethylenephosphonic acid (DETPMP) and its salts, hexamethylenediaminetetramethylenephosphonic acid (HMDTMP) and its salts, vinylphosphonic acid and its salts, phenylphosphonic acid and its salts, β-glycerophosphoric acid and its salts, DL-2-aminophosphonobutyric acid and its salts, di ... β-glycerophosphoric acid and its salts, DL-2-aminophosphonobutyric acid and its salts, diphenylphosphonic acid and its salts, β-glycerophosphoric acid and its salts, β-glycerophosphoric acid and its salts, DL-2-aminophosphonobutyric acid and its salts, diphenylphosphonic acid and its salts, β-glycerophosphoric acid and its salts, β-glycerophosphoric acid and its salts, DL- 2. The anti-fingerprint improving agent according to claim 1, which is at least one chelating agent selected from the group consisting of sulfonic acid and its salts, aminomethylphosphonic acid (AMP) and its salts, polyaminopolyethermethylenephosphonic acid (PAPEMP) and its salts, bishexamethylenetriaminepentamethylenephosphonic acid (BHMTMP) and its salts, nitrilotrismethylenetrisphosphonic acid N-oxide (ATMP-NO) and its salts, phosphonoformic acid and its salts, polymaleic acid phosphonate and its salts, hydroxyphosphonoacetic acid and its salts, and ethanolaminebismethylenephosphonic acid and its salts.

4. 2. The anti-fingerprint agent according to claim 1, wherein the content of the phosphorus-containing chelating agent in the anti-fingerprint agent is 10 mg / L or less.

5. 2. The anti-fingerprint agent according to claim 1, wherein the coating is a coating having holes and / or a dyed coating.

6. A method for improving the fingerprint resistance of a film using the fingerprint resistance improving agent according to claim 1, comprising: the coating is an anodized coating of aluminum or an aluminum alloy, (1) A method for manufacturing a film by immersing the film in the anti-fingerprint agent containing a phosphorus-containing chelating agent according to claim 1 to perform a sealing treatment and / or a dye fixing treatment on the film, In the step of performing the sealing treatment, the pH of the anti-fingerprint agent is 2 or more and 9 or less, In the step of performing the dye fixing treatment, the pH of the fingerprint resistance improver is 2 or more and 6 or less, The step (1) is carried out by adjusting the liquid temperature of the anti-fingerprint agent to a temperature range of 80°C or higher. method.

7. 7. The method according to claim 6, wherein the phosphorus-containing chelating agent is at least one chelating agent selected from the group consisting of organic chelating agents.

8. The phosphorus-containing chelating agent may be hydroxyethylidene diphosphonic acid and its salts, nitrilotrismethylenephosphonic acid (NTMP) and its salts, phosphonobutanetricarboxylic acid (PBTC) and its salts, ethylenediaminetetramethylenephosphonic acid (EDTMP) and its salts, diethylenetriaminepentamethylenephosphonic acid (DETPMP) and its salts, hexamethylenediaminetetramethylenephosphonic acid (HMDTMP) and its salts, vinylphosphonic acid and its salts, phenylphosphonic acid and its salts, β-glycerophosphoric acid and its salts, DL-2-aminophosphonobutyric acid and its salts, di ... β-glycerophosphoric acid and its salts, DL-2-aminophosphonobutyric acid and its salts, diphenylphosphonic acid and its salts, β-glycerophosphoric acid and its salts, β-glycerophosphoric acid and its salts, DL-2-aminophosphonobutyric acid and its salts, diphenylphosphonic acid and its salts, β-glycerophosphoric acid and its salts, β-glycerophosphoric acid and its salts, DL-2 7. The method of claim 6, wherein the chelating agent is at least one selected from the group consisting of hydroxylphosphonic acid and its salts, aminomethylphosphonic acid (AMP) and its salts, polyaminopolyethermethylenephosphonic acid (PAPEMP) and its salts, bishexamethylenetriaminepentamethylenephosphonic acid (BHMTMP) and its salts, nitrilotrismethylenetrisphosphonic acid N-oxide (ATMP-NO) and its salts, phosphonoformic acid and its salts, polymaleic acid phosphonate and its salts, hydroxyphosphonoacetic acid and its salts, and ethanolaminebismethylenephosphonic acid and its salts.

9. The method according to claim 6, wherein the content of the phosphorus-containing chelating agent in the anti-fingerprint improver is 10 mg / L or less.

10. The method of claim 6, wherein the coating is a porous coating and / or a dyed coating.

11. The method according to claim 6, wherein the step (1) is carried out by adjusting the liquid temperature of the anti-fingerprint agent to a temperature range of 80°C or higher and 98°C or lower.

12. A fingerprint-resistant article produced using the fingerprint-resistant improving agent according to any one of claims 1 to 5.

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