JP2017066357A - Aqueous base conditioner composition, manufacturing method of steel material using composition and coated steel material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous base conditioner composition capable of fixing dust by sufficiently penetrating into a dust later of a surface of a steel material even without containing an organic solvent, excellent in corrosion resistance for long time, good in drying property and desirable in aspects of workability and environmental protection.SOLUTION: There is provided a two-liquid mixed type aqueous base conditioner used by application on a steel material having a dust on a surface and containing (A) a main agent and (B) a curing agent, wherein the main agent (A) contains one or more kind selected from a group consisting of (A-1) a water soluble or water dispersible resin having 1 or more hydroxyl group and/or a carboxyl group in a molecule, (A-2) a rust preventive pigment, (A-3) a corrosive ion fixing agent and (A-4) a silane coupling agent and has viscosity at a temperature of 23°C of 1 to 5000 mPa s, the curing agent (B) contains the water dispersible polyisocyanate resin and a ratio of hydroxyl group equivalent in the main group (A) and isocyanate group equivalent in the curing agent (B) (isocyanate group equivalent/hydroxyl group equivalent) is 1.0 to 1.7.SELECTED DRAWING: None

Description

  The present invention relates to a substrate conditioner composition that does not require or can reduce substrate preparation such as rust removal during repainting of steel materials, and more particularly, is a water-based and has good workability in painting. The present invention relates to a water-based substrate conditioner composition having a low environmental load.

  When it is time to repaint existing steel structures, a lot of red rust is usually generated on the surface of the steel material. The period cannot be protected. Therefore, before repainting, it was necessary to perform paint removal after applying a physical rust removal treatment (base adjustment) of at least three types of kelen such as blasting. However, since a large amount of dust and noise are generated during the work, there is a problem that the work environment and work efficiency are very poor. Thus, conventionally, instead of performing such physical substrate adjustment, several methods of applying a coating-type substrate adjusting agent that does not require or reduces the substrate adjustment have been proposed. A shift is being made.

And, as a method using such a substrate conditioner, for example, a moisture-curing resin that takes in and agglomerates moisture present in the rust layer is used as a rust preventive pigment or a corrosive ion (Cl ⁻ , SO ₄ ^{2 -,} etc.) surface preparation agent used in conjunction with fixing agent and a coupling agent, prescribed for curing a method (Patent documents 1 and 2) to passivate the steel by fixing the rust, the water of rust layer (Patent Documents 3 and 4) have been proposed that use a base conditioner that uses an epoxy resin paint of the above together with a ketimine compound (curing agent) or a silane coupling agent. Here, since it is necessary to make the viscosity of the substrate conditioner considerably lower than that of a general paint in order to sufficiently permeate the rust layer, the substrate conditioner disclosed in Patent Documents 1 to 4 In any case, a large amount of organic solvent such as xylene is blended. For this reason, the amount of the organic solvent discharged into the atmosphere at the time of painting is large, and there is a problem that the burden on the painter and the environment is large. Therefore, a water-based substrate adjusting agent has been desired as a substrate adjusting agent that does not contain an organic solvent and can sufficiently penetrate the rust layer to fix rust.

By the way, as a mechanism that rust is generated in the first place, when moisture is attached to iron and a local battery is formed, electrons and iron ions (Fe ²⁺ ) are generated in the anode portion by an oxidation reaction of iron. At the cathode, electrons corresponding to the amount of electrons generated at the anode due to the reduction reaction of dissolved oxygen in the water are consumed, and at the same time, hydroxide ions (OH ⁻ ) are generated. Further, the Fe ²⁺ ions are combined with OH ⁻ to generate insoluble rust.
In other words, the presence of water causes rusting. So far, when coating anti-corrosion paints containing water on steel materials, in order to prevent rusting over time, physical adjustment of the substrate However, as described above, physical substrate adjustment is very bad in work environment and work efficiency. In this way, painting with water containing rust tends to be avoided in the past, but long-term anticorrosive effects can be prevented without the need for physical preparation. There has been a demand for a water-based substrate conditioner that can provide the following.

So far, as a water-based substrate conditioner, for example, a water-based paint for rust conversion in which an acrylic-modified composite emulsion, a polyphenol derivative, a phosphite, and a stainless alloy powder are blended at a certain ratio has been proposed (Patent Document 5). ). However, the water-based paint for converting rust proposed in Patent Document 5 does not crosslink in the rust layer, and forms a composite film with rust only by fusion by drying, so that water adheres to the surface after coating. In this case, water easily penetrates through the surfactant on the surface of the acrylic-modified composite emulsion, and water is easily retained in the particle pockets between the emulsions. In this point, it is not sufficient, and there is a concern that rust will be generated over time, and that long-term corrosion resistance cannot be sufficiently secured.
Therefore, the viscosity is low without using an organic solvent, so that it can sufficiently penetrate into the rust layer to fix rust, and prevent the occurrence of rust over time without requiring physical adjustment of the substrate. There has been a demand for a water-based substrate conditioner that can ensure long-term corrosion resistance.

JP 2002-285362 A JP 2008-260018 A JP 60-077862 A Japanese Unexamined Patent Publication No. 01-25877 JP 2009-040929 A

  Accordingly, the inventors of the present application have made extensive studies on such a substrate conditioner, and are composed of a specific water-soluble or water-dispersible resin, and a rust preventive pigment, a corrosive ion fixing agent, and a silane coupling agent. By using a curing agent containing a specific water-dispersible polyisocyanate resin together with one or more selected from the group as a main agent, a two-component mixed-type aqueous base conditioner composition is used. Even if not used, it can penetrate into the rust layer sufficiently to fix rust, prevent the occurrence of rust over time without requiring physical substrate adjustment, and ensure long-term corrosion resistance, The present invention was completed by finding for the first time that a water-based substrate conditioner composition having good drying properties and good workability can be obtained.

  Accordingly, the object of the present invention is to sufficiently penetrate the rust layer and fix the rust without using an organic solvent, and to prevent the occurrence of rust over time without requiring physical substrate adjustment. It is an object of the present invention to provide a water-based substrate conditioner composition that can guarantee long-term anticorrosion properties, and has good drying properties and good workability.

  Another object of the present invention is to apply such a water-based substrate conditioner composition to a steel material having rust on the surface, and further to this, an acrylic resin-based paint, urethane resin-based paint, epoxy resin-based A steel material having rust on the surface, on which a coating film is formed on the surface of the steel material by applying a paint containing at least one selected from the group consisting of a paint, a chlorinated polyolefin paint, a silicone resin paint and a fluorine resin paint It is to provide a coated steel material in which the coating is applied to a steel material having rust on the surface.

That is, the present invention is used by applying to a steel material having rust on the surface, and is a two-component mixed-type aqueous base conditioner composition containing (A) a main agent and (B) a curing agent,
The main agent (A) is (A-1) a water-soluble resin or water-dispersible resin having one or more hydroxyl groups and / or carboxyl groups in one molecule, (A-2) an antirust pigment, and (A-3). Containing at least one selected from the group consisting of a corrosive ion fixing agent and (A-4) a silane coupling agent, and having a viscosity at 23 ° C. of 1 to 5000 mPa · s,
The curing agent (B) includes a water-dispersible polyisocyanate resin,
A ratio of a hydroxyl group equivalent in the main agent (A) and an isocyanate group equivalent in the curing agent (B) (isocyanate group equivalent / hydroxyl group equivalent) is 1.0 to 1.7. It is a regulator composition.

  Further, the present invention provides an acrylic resin-based paint, urethane resin-based paint, epoxy resin-based paint, chlorinated polyolefin-based paint, silicone resin, after coating the above-mentioned aqueous base conditioner composition on a steel material having rust on the surface. A coating method of a steel material having rust on the surface, characterized in that a coating material is formed on the surface of the steel material by coating a paint containing at least one selected from the group consisting of a paint based on fluorine and a fluororesin paint. .

  Further, the present invention is selected from the group consisting of the water-based substrate conditioner composition and acrylic resin-based paint, urethane resin-based paint, epoxy resin-based paint, chlorinated polyolefin-based paint, silicone resin-based paint, and fluorine resin-based paint. The coating material containing at least one kind is a coated steel material in which steel materials having rust on the surface are sequentially coated.

  According to the aqueous substrate conditioner composition of the present invention, it is possible to fix the rust by sufficiently penetrating into the rust layer without using an organic solvent. it can. Furthermore, the water-based substrate conditioner composition in the present invention has good drying properties and is very preferable from the viewpoint of workability and environmental protection.

FIG. 1 is an explanatory diagram showing the results of applying the compositions according to Example 18 and Comparative Example 9 to iron rust pigments and testing their permeability.

  Hereinafter, the present invention will be described in detail, but the scope of the present invention is not limited to these descriptions, and modifications other than the following examples can be made as appropriate without departing from the spirit of the present invention.

  In the present invention, the steel material to be coated includes a steel material as a base material processed into a plate, a rod, a pipe, or a structure, such as a road, a power transmission or communication tower, a bridge. Various plants and the like can be exemplified, but are not limited thereto, and other metal elements other than iron can be included. Moreover, about the steel material in this invention, after the old coating film is removed, the base-material regulator composition of this invention may be applied, and it may be applied with the old coating film left. Here, in the present invention, the “steel material having rust on the surface” is not limited, but the steel material whose surface is rusted by a corrosion factor such as water, oxygen, chloride ion, sulfate ion, etc. On the other hand, it refers to a steel material that has been subjected to a base adjustment of cleaning degree as a pretreatment. Specific pre-treatments include removal of fragile parts such as deteriorated paint film and floating rust with a wire brush, scotch bright (trade name, manufactured by 3M Co., Ltd.), or layered rust and bump rust. If there is a significant portion of corrosion, it is removed with a power polishing tool or a hand polishing tool, but it is not necessary to remove the rust fixed on the surface of the steel material. In addition, substrate preparation generally refers to a process that removes rust generated on the surface of steel, dirt such as attached oil, dust, dust, and dirt, and old paint film before painting. Specifically, depending on the work content and method, one type of kelen (the blasting method is used to remove all rust and old paint film to expose the surface of the steel material), two types of kelen (a power tool and a hand tool) Combined use to remove old paint film, rust and expose steel surface), 3 kinds of keren (power tool and hand tool used together, leave a healthy paint film, but other paint film cracks, Non-defective parts such as blisters and rust are removed), and four types of keren (a power tool and a hand tool are used in combination to remove powdered matters and dirt). That is, in the present invention, the base adjustment of the cleaning level is not limited, but corresponds to a process of about 4 types of keren.

  The substrate conditioner composition of the present invention is a two-component mixed type composition containing (A) a main agent and (B) a curing agent described below, and is a water-based substrate conditioner composition. This will be specifically described below.

  Here, in the present invention, “water-based”, “water-soluble”, and “water-dispersible” are synonymous with those commonly used in the art, but “water-based” means that water is used as a medium. In addition, "water-soluble resin" refers to a resin in which a resin having a hydrophilic group is dissolved in water, "water-dispersible resin" refers to forced emulsification, self-emulsification, suspension polymerization, emulsion polymerization, This refers to a resin dispersed in water with an emulsifier or a hydrophilic group, obtained by miniemulsion polymerization or the like.

<(A) Main agent>
The main agent (A) used in the substrate conditioner composition of the present invention includes (A-1) a water-soluble resin or water-dispersible resin having one or more hydroxyl groups and / or carboxyl groups in one molecule, and (A -2) 1 or more types chosen from the group which consists of a rust preventive pigment, (A-3) corrosive ionization fixing agent, and (A-4) silane coupling agent.

  As the component (A-1) of the present invention, a water-soluble resin having one or more hydroxyl groups and / or carboxyl groups in one molecule (hereinafter sometimes simply referred to as “water-soluble resin”), And a water-dispersible resin having one or more hydroxyl groups and / or carboxyl groups in one molecule (hereinafter sometimes simply referred to as “water-dispersible resin”). Here, both the water-soluble resin and the water-dispersible resin preferably have 1 or more hydroxyl groups per molecule from the viewpoint of reacting with the curing agent, and more preferably 2 or more. Further, the hydroxyl group content in the resin composition is preferably 0.1% or more, and more preferably 0.1% to 10%.

  Here, the water-soluble resin has one or more hydroxyl groups and / or carboxyl groups in one molecule, has water solubility, and reacts with an isocyanate group in the curing agent (B) described later. As long as it cures, its form, type, etc. are not particularly limited, and specifically, it is composed of styrene acrylic resin, acrylic resin, polyester resin, etc., and amide group, polyoxyalkylene group, etc. Resin having nonionic functional group, resin having cationic functional group such as amino group, imino group and hydrazino group, or resin having anionic functional group such as carboxylic acid group, sulfonic acid group and phosphoric acid group Is mentioned. Specific product names of this water-soluble resin include Plus Coat Z-221, Plus Coat Z-730, Plus Coat Z-446, etc. manufactured by Kyoyo Chemical Industry Co., Ltd.

  The form of use of the water-soluble resin is not particularly limited, and examples thereof include a form dissolved in an aqueous medium such as water and a dispersed form.

  On the other hand, the water-dispersible resin has one or more hydroxyl groups and / or carboxyl groups in one molecule, has water dispersibility, and reacts with an isocyanate group in the curing agent (B) described later. The type and type are not particularly limited as long as they can be cured, but specifically, styrene acrylic resin, acrylic resin, urethane resin, silicone resin, acrylic silicone resin, acrylic urethane resin, fluorine Examples thereof include resins and acrylic fluororesins. Specific product names of this water-dispersible resin include: Bihydrol A145, Bihydrol A2290, Bihydrol A2427, Bihydrol A2542, Bihydrol A2546, Bihydrol A2601, Bihydrol A242, manufactured by DIC Corporation, manufactured by Sumika Bayer Urethane Co., Ltd. Barnock WE-303, Barnock WE-304, Barnock WE-306, Barnock WE-308, Barnock WE-313, Lumiflon FE-4200, Lumiflon FE-4300, Lumiflon FE-4400, Lumiflon FE-4500, etc. manufactured by Asahi Glass Co., Ltd. Can be mentioned.

  The form of use of this water-dispersible resin is not particularly limited, but is obtained by forced emulsification, self-emulsification, suspension polymerization, emulsion polymerization, miniemulsion polymerization, etc., in an aqueous medium such as water with an emulsifier or a hydrophilic group. The resin form dispersed in is mentioned.

  These water-soluble resins and water-dispersible resins may be used alone or in combination of two or more as long as they are not reactive with each other. In the case of using a mixture of two or more, a plurality of water-soluble resins or water-dispersible resins having different molecular chains (repeating units) of one molecule may be mixed, respectively, or the plurality of water-soluble resins and A water-dispersible resin can be arbitrarily mixed.

  The component (A-1) preferably has a hydroxyl value of 20 to 200 mgKOH / g, more preferably a hydroxyl value of 30 to 150 mgKOH / g. If the hydroxyl value is less than 20 mgKOH / g, the crosslinking density of the resulting coating film tends to be low, so that the ability to fix rust tends to be low. Conversely, if the hydroxyl value exceeds 200 mgKOH / g, the water resistance is high. This is because the viscosity tends to be inferior, and the viscosity of the main agent preferable as an aqueous base conditioner tends to be difficult to obtain.

  The component (A-1) preferably has a weight average molecular weight Mw of 1,000 to 500,000, more preferably 2, from the viewpoint of coating film performance and permeability to the rust layer. 000-300,000.

  And as the main ingredient (A) of the present invention, such a component (A-1) is contained, but the content of this (A-1) ingredient is the main ingredient from the viewpoint of coating film performance such as corrosion resistance. 20-95 mass% is preferable in (A), More preferably, you may be 50-80 mass%.

In addition to the component (A-1), the main agent (A) of the present invention further contains at least one of the following components (A-2) to (A-4). . That is, the main agent (A) of the present invention includes a rust preventive pigment (A-2) for more effectively preventing rusting of a steel material, and Cl ^- or the like present at the interface between the rust layer and the iron base in the steel material. Corrosion ions such as SO ₄ ^2- are collected and chemically reacted to fix and inactivate as a water-insoluble double salt. A silane coupling agent (A-4) for improving wettability and impregnating property, and for improving adhesion with a paint to be coated thereon, contains at least one of them alone, or 2 More than one species can be appropriately selected and used within the scope of the object of the present invention.

  As the rust preventive pigment (A-2), known pigments can be used. For example, aluminum phosphate, condensed aluminum phosphate, zinc phosphate, aluminum phosphite, zinc phosphite, calcium phosphite, (Sub-) phosphates such as zinc strontium phosphate, molybdates such as zinc molybdate, calcium molybdate, manganese molybdate; other stearic acid, tannic acid, citric acid, itaconic acid, boric acid, tungstic acid, etc. And metal salts of various acids. 0-30 mass% is preferable, and, as for content of the said rust preventive pigment (A-2) in a main ingredient (A), More preferably, you may be 5-20 mass%.

  Moreover, as said corrosive ion fixing agent (A-3), a well-known thing can be used, However, Hydrocalumite, a hydrotalcite, etc. are mentioned typically. The content of the corrosive ion fixing agent (A-3) in the main agent (A) is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass.

  Moreover, as said silane coupling agent (A-4), although a well-known thing can be used, for example, (gamma) -glycidoxy propyl trimethoxysilane, (gamma) -glycidoxy propylmethyl diethoxysilane, (beta)-( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxytrimethoxysilane, γ-mercaptopropyltrimethoxysilane and the like. The content of the silane coupling agent (A-4) in the main agent (A) is preferably 0 to 30% by mass, more preferably 5 to 20% by mass.

  And the main ingredient (A) in this invention needs to have a viscosity of 1 to 5,000 mPa · s at a temperature of 23 ° C. because of having such a composition. When the viscosity is lower than 1 mPa · s, liquid sag occurs particularly during coating of a vertical surface or the like, so that the workability of coating is inferior. On the contrary, when the viscosity is higher than 5,000 mPa · s, This is because it becomes difficult to fix the rust by sufficiently infiltrating the rust. A preferable viscosity of the main agent (A) is 1,000 to 3,500 mPa · s.

  Further, the main agent (A) in the present invention may further contain an aqueous dispersion medium within the scope of the present invention. As such an aqueous dispersion medium, known ones can be used. For example, methanol, ethanol, propyl alcohol and the like can be used singly or in combination of two or more. The content of the dispersion medium in the main agent (A) is preferably 20% by mass or less, more preferably 0% by mass, from the viewpoint of working environment and environmental protection.

  The main agent (A) in the present invention may contain an organic solvent as long as the object of the present invention is not impaired. As the organic solvent, known ones can be used, and glycol ether solvents such as ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol monophenyl ether, dipropylene glycol monobutyl ether, methanol, ethanol, propyl alcohol, ester alcohol, benzyl alcohol. Examples thereof include alcohols such as 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, and the like can be used alone or in combination of two or more. The content of the organic solvent in the main agent (A) is preferably 10% by mass or less, more preferably no organic solvent, from the viewpoint of the working environment and environmental protection.

  Further, in the aqueous substrate conditioner composition of the present invention, in the main agent (A), within the scope of the object of the present invention, if necessary, extender pigments, color pigments, pigment dispersants, surface conditioners other than those described above. , Anti-sagging agents, antifoaming agents, and the like.

<(B) Curing agent>
The curing agent (B) in the present invention includes a water-dispersible polyisocyanate resin. Since this water-dispersible polyisocyanate resin has an isocyanate group, the hydroxyl group or carboxyl group contained in the main agent (A) reacts with the isocyanate group of the curing agent and cures. By using a dispersible polyisocyanate resin, it can be easily mixed with the water-based resin of the main agent (A), and a crosslinked film is formed in the coated rust layer by the reaction of hydroxyl groups, carboxyl groups and isocyanate groups. Therefore, it is preferable in that rust can be fixed in the crosslinked film.
Here, the water-dispersible polyisocyanate resin refers to a polyisocyanate resin that can self-emulsify and disperse in an aqueous medium when stirred in an aqueous medium such as water, and known ones can be used. In the present invention, any of a mixture of a hydrophobic isocyanate and a hydrophilic isocyanate, a mixture of a hydrophobic isocyanate and a hydrophilic dispersant, a polyisocyanate having a hydrophilic group, and the like can be used. The polyisocyanate having a hydrophilic group can be prepared by various methods, for example, a method of introducing an ethylene oxide group, a propylene oxide group or the like, which is a nonionic and hydrophilic functional group, into the polyisocyanate. And a method of introducing a compound containing an ionic group or a latent ionic group (for example, a hydroxyl group, an amino group, a carboxyl group, a sulfonic acid group, a silanol group) into a polyisocyanate.

  Specific product names of the water-dispersible polyisocyanate resin in the present invention include Burnock DNW-5000, Burnock DNW-5500, Burnock DNW-5010, Burnock DNW-5100, Burnock DNW-5200, Burnock manufactured by DIC Corporation. DNW-6000, Vernock DNW-6500, Takenate WD-725, Takenate WD-726, Takenate WD-730, manufactured by Mitsui Chemicals, Inc. Duranate WB40-100, Duranate WB40-80D, Duranate WT30 manufactured by Asahi Kasei Chemicals Corporation -100, Duranate WT20-100, Duranate WE50-100, Duranate WL70-100, Duranate WR80-70P, Bihydur 3100 manufactured by Sumika Bayer Urethane Co., Ltd. Bihijoule 304, Bihijoule 305, Bihijoule XP2700, Bihijoule XP2547, Bihijoule 2487/1, Bihijoule 2655, Bihijoule 401-70, Bihijoule XP2759, Death Module N3300, Death Module N3600, Death Module N3900, Death Module N3400, Death Module XP2580, Desmodur XP2565, Nippon Polyurethane Co., Ltd. Coronate AQ-200, Coronate AQ-210, Coronate AQ-120, Coronate AQ-105, etc. are mentioned.

  In the present invention, the hydroxyl equivalent of the water-soluble resin or water-dispersible resin contained in the main agent (A) from the viewpoints of sufficiently curing the coating film, coating film performance such as anticorrosion, and permeability to the rust layer. And the equivalent ratio (isocyanate group equivalent / hydroxyl group equivalent) of the water-dispersible polyisocyanate resin contained in the curing agent (B) in the range of 1.0 to 1.7, preferably The equivalence ratio is preferably 1.1 to 1.6, more preferably 1.2 to 1.5. When the equivalent ratio is less than 1.0, the coating film does not have sufficient crosslinking and the coating properties such as water resistance are deteriorated. On the contrary, when the equivalent ratio exceeds 1.7, the polyisocyanate is excessive. It is not preferable because it reacts with moisture and foams and the physical properties of the coating film deteriorate. These hydroxyl group equivalents can be calculated from the OH group content (%) of the resin in the component (A-1), and the isocyanate equivalents of the water-dispersible polyisocyanate in the component (B). It is possible to calculate from the NCO group content (%).

  Moreover, about this water dispersible polyisocyanate resin, it is preferable that weight average molecular weight Mw is 800-7,000 from a viewpoint of coating-film performance, such as drying property and corrosion resistance, More preferably, it is 1,000. ~ 5,000.

  The curing agent (B) in the present invention contains, for example, a melamine compound or a compound having an alkoxysilyl group as a curing component other than the water-dispersible polyisocyanate resin, as long as the object of the present invention is not impaired. Can do. In this case, the curing component other than the water-dispersible polyisocyanate resin is preferably 50% by mass or less in the curing agent (B).

  In the aqueous substrate conditioner composition of the present invention, the content of the aqueous dispersion medium when the main agent (A) and the curing agent (B) are mixed is preferably 0 to 50% by mass. More preferably, the dispersion medium may not be included as long as both the main agent (A) and the curing agent (B) satisfy the above-mentioned viscosity range and can sufficiently penetrate into the rust layer. Further, the content of the organic solvent in the composition is preferably 20% by mass or less in the composition within a range not impairing the object of the present invention, and is preferably 5% by mass or less from the viewpoint of working environment and environmental protection. More preferably, the organic solvent is not included. Note that, in the present invention, not containing an aqueous dispersion medium or an organic solvent is intended to exclude an extremely small amount of an aqueous dispersion medium or an organic solvent that is inevitably mixed in the preparation of the aqueous substrate conditioner composition of the present invention. is not.

As described above, the aqueous base conditioner composition of the present invention prepared in this way is applied to a steel material having rust as described above. As a pretreatment, a brittle part such as a deteriorated coating film and floating rust is removed with a wire brush, scotch. Remove it with Bright (trade name, manufactured by 3M Co., Ltd.), etc., and if there is significant corrosion such as layered rust or bump rust, remove it with a power polishing tool or a hand polishing tool. However, it is not necessary to remove the fixed rust. As a coating method, it can be based on a brush, a roller, a spray, etc. Of these, a brush and a roller are preferably used from the viewpoint of workability and paint scattering. As a coating amount, about 0.03-0.2 kg / m < ² > is applied in solid content conversion, and it is naturally dried. In addition, the viscosity at the time of coating the aqueous substrate conditioner composition is preferably 1 to 5000 mPa · s (temperature 23 ° C.) from the viewpoint of sufficient penetration into the rust layer, and the viscosity at the time of coating. Is more preferably 1,000 to 3,500 mPa · s (temperature 23 ° C.). In this invention, the viscosity after mixing the said main ingredient (A) and a hardening | curing agent (B) to make an aqueous | water-based body conditioner composition can maintain 1-5000 mPa * s (temperature 23 degreeC) for 3 hours or more. Preferably, it is 5 hours or more.

  The aqueous substrate conditioner composition of the present invention coated as described above can be dried at room temperature. Here, the normal temperature differs depending on the atmospheric temperature of the environment in which the coating is performed, but usually refers to 23 ° C. and means that no temperature operation such as forced heating or cooling is performed. About the aqueous | water-based body conditioner composition of this invention, it is preferable to coat in the environment of temperature 5-35 degreeC.

  The aqueous substrate conditioner composition of the present invention is preferably sufficiently infiltrated into the rust layer during the above coating, but as an indicator of its permeability, there is cross-sectional observation, for example, the substrate of the present invention The element distribution state of the cross section of the rusted steel sheet coated with the regulator composition can be measured by a method using an electron beam microanalyzer.

  In the present invention, after forming the coating film by coating the above-mentioned water-based substrate conditioner composition on a steel material having rust on the surface, an acrylic resin-based paint, a urethane resin-based paint, an epoxy resin-based coating is formed thereon. A paint containing at least one selected from the group consisting of paints, chlorinated polyolefin paints, silicone resin paints, and fluororesin paints, is preferably applied once to four times to prevent blistering or peeling for a long period of time. It is preferable to form a film. The coating material to be applied over the aqueous substrate conditioner composition is appropriately selected depending on the coating material and is not limited, but preferably, the total coating thickness to be formed is 55 μm or more. The method of drying the paint to be applied repeatedly includes drying at room temperature, and the physical properties of the coated film after drying include weather resistance, water resistance, adhesion, alkali resistance, flex resistance, acid resistance, etc. Desired. The paint used for recoating can be JIS K5551 (rust-preventing paint for structures) if it is an undercoat, JIS K5659 (medium-resistant weatherproof paint for steel structures) if it is an intermediate paint, or topcoat. For example, it is preferable that the paint satisfies the requirements of JIS K5659 (weather-resistant paint for steel structures).

  Hereinafter, the aqueous substrate conditioner composition of the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified.

[Examples 1-37 and Comparative Examples 1-9]
First, as shown in Tables 1 to 3, a main agent (A) and a curing agent (B) were prepared. About each of the main ingredient (A) and the hardening | curing agent (B), the viscosity was measured by the below-mentioned method.

[Test methods and evaluation]
Two types of JIS K5621 (general rust-preventing paint) are applied to one half (75 x 70 mm) of a polished mild steel sheet with dimensions of 150 x 70 x 1.6 mm that has been degreased and cleaned with xylene. Nippon Paint Co., Ltd. product name]] was applied twice, and then JIS K5516 (synthetic resin blend paint) for 2 types of intermediate coating ["Tyco Marine Intermediate Co., Ltd., Dainippon Paint Co., Ltd. product name]] Apply once, and finally apply JIS K5516 (synthetic resin blend paint) 2 types of top coat [“Tyco Marine top coat” [trade name, manufactured by Dainippon Paint Co., Ltd.]] to obtain a test coating plate It was. The coating film thus formed is hereinafter referred to as “old coating film”.

The obtained test coating plate was exposed outdoors for 12 months to cause rust. In addition, it apply | coated so that salt might be converted into the amount of Cl and might become 500 mg / m < ² > after 6 months of exposure. The surface of the rust-coated plate thus obtained was applied with the following coating specifications.

<Pretreatment>
Only the deposits and brittle rust on the surface of the rust-coated plate were removed with Scotch Bright (trade name, manufactured by 3M).

<Application of aqueous substrate conditioner composition>
The prepared main agent (A) and curing agent (B) were mixed according to the compositions shown in Tables 1 to 3, respectively, to obtain water-based substrate conditioner compositions according to Examples 1 to 37 and Comparative Examples 1 to 9, respectively. The surface of the rusted coated plate after the treatment was applied with a brush so that the coating amount was 0.10 kg / m ^2, and was naturally dried in an environment at a temperature of 23 ° C. for 1 day. In addition, the viscosity at the time of the application | coating of the water-system base agent composition which concerns on Examples 1-37 was all 5,000 mPa * s or less.
Odor, painting workability, permeability to rust, drying properties, and water resistance were evaluated by the methods described below.

<Applying undercoat paint>
After applying the aqueous substrate conditioner composition as described above, a modified epoxy resin paint weak solvent type [“Epoall Smile” [trade name, manufactured by Dainippon Paint Co., Ltd.]] is applied as an undercoat. It apply | coated with the air spray so that it might become 22 kg / m < ² >, and it naturally dried for one day in the environment of temperature 23 degreeC.

<Intermediate paint application>
After the application of the undercoat paint, an intermediate coat paint for fluororesin paint [“V Freon 100 # Smile Midcoat” [trade name, manufactured by Dainippon Paint Co., Ltd.]] is applied as an intermediate coat paint of 0.16 kg / m ^2. It was applied by air spray as described above, and was naturally dried for 1 day in an environment at a temperature of 23 ° C.

<Applying top coat>
After the intermediate coating is applied, the top coating for fluororesin coating [“V Freon 100 # Smile Top Coating” (trade name, manufactured by Dainippon Paint Co., Ltd.)] is applied so that the coating amount is 0.15 kg / m ^2. It apply | coated with the spray and it naturally dried for one day in the environment of a temperature of 23 degreeC.

  Next, the coated plate after the application of the top coating was cured for 7 days under the conditions of 20 ° C. and 50% RH. About the some test coating board obtained in this way, anticorrosion property was evaluated by the below-mentioned method.

Notes 1) to 12) in Table 1 are as follows.
<(A-1) component>
Note 1): Bihydrol A145; manufactured by Sumika Bayer Urethane Co., Ltd., hydroxyl group-containing acrylic dispersion, nonvolatile content 45%, OH group content 3.3%, hydroxyl value 109 mgKOH / g (resin conversion), acid value 10 mgKOH / g, Mn = 3900, Mw = 13000, viscosity (23 ° C.) 950 mPa · s (dispersion medium: water), average particle diameter (D50) = 150 nm
Note 2): Bihydrol A2601, manufactured by Sumika Bayer Urethane Co., Ltd., hydroxyl group-containing acrylic dispersion, non-volatile content 45%, OH group content 3.9%, hydroxyl value 129 mgKOH / g (resin conversion), viscosity (23 ° C. ) 2200 mPa · s (dispersion medium: water)
Note 3): Lumiflon FE4200: manufactured by Asahi Glass Co., Ltd., hydroxyl group-containing fluororesin emulsion, non-volatile content 50%, OH group content 1.6%, hydroxyl value 54 mgKOH / g (resin conversion), viscosity (23 ° C.) 500 mPa · s (dispersion medium: water), average particle diameter (D50) = 100 to 200 nm
Note 4): Pluscoat Z-730: manufactured by Kyoyo Chemical Industry Co., Ltd., carboxyl group-containing water-soluble polyester resin, non-volatile content 25%, carboxyl group content 4.0%, acid value 40-60 mgKOH / g (resin conversion) ), Viscosity (23 ° C.) 10 mPa · s (dispersion medium: water)
Note 5): Boncoat 40-418EF; DIC Corporation, acrylic emulsion, non-volatile content 55%, OH group content 0% (as solid content), viscosity (23 ° C.) 1000 mPa · s (dispersion medium: water), Average particle diameter (D50) = 250 nm
Note 6): Boncoat 5400EF; DIC Corporation, acrylic-styrene emulsion, non-volatile content 55%, OH group content 0% (as solid content), viscosity (23 ° C.) 3000 mPa · s (dispersion medium: water), Average particle diameter (D50) = 200 nm

<(A-2) component>
Note 7): K White # 94; manufactured by Teika Co., Ltd., aluminum phosphate rust preventive pigment

<(A-3) component>
Note 8): Solkat C; manufactured by Nippon Chemical Industry Co., Ltd., corrosive ion immobilizing agent

<(A-4) component>
Note 9): KBM403; manufactured by Shin-Etsu Silicone Co., Ltd., silane coupling agent

<(B) Curing agent>
Note 10): Takenate WD-725; manufactured by Mitsui Chemicals, water-dispersible polyisocyanate resin (water-dispersible polyisocyanate having a hydrophilic group), nonvolatile content 100%, NCO content 16%, Mw = 2000, viscosity (23 ° C) 800 mPa · s
Note 11): Vernock DNW-6000; manufactured by DIC Corporation, water-dispersible polyisocyanate resin (water-dispersible polyisocyanate having a hydrophilic group), non-volatile content 100%, NCO content 16%, Mw = 6000, viscosity ( 23 ° C.) 2300 mPa · s
Note 12): Duranate TUL-100; manufactured by Asahi Kasei Chemicals Corporation, solvent-based polyisocyanate resin, nonvolatile content 100%, NCO content 23%, Mw = 2000, viscosity (23 ° C.) 300 mPa · s

Each evaluation method is as shown below.
<Viscosity>
It measured using the B-type viscometer [Tokyo Keiki Co., Ltd. product]. The measurement conditions are shown below.
・ Temperature: 23 ℃
・ Rotor: No. 3
・ Rotation speed: 12rpm

<Odor>
The odor at the time of painting was qualitatively evaluated from the presence or absence of solvent odor and discomfort felt by the painter.
A: There is no odor and no discomfort during painting.
○: Odor is felt, but there is no discomfort during painting.
Δ: Odor and slightly uncomfortable feeling during painting
X: Strong odor and great discomfort during painting.

<Coating workability>
The coating workability during painting was qualitatively evaluated according to the following evaluation criteria.
(Double-circle): The elongation of a base-material regulator composition is very good, and it can paint easily.
○: The substrate conditioner composition has good elongation and can be painted without problems.
(Triangle | delta): The elongation of a base-material adjustment agent composition is a little bad, and a brush may sometimes get caught at the time of coating.
X: The stretch of the substrate conditioner composition is very poor, and the brush is caught at the time of painting, which makes it difficult to paint.

<Penetration into rust>
The state of element (carbon and iron) distribution in the cross section of the coated plate coated with the substrate conditioner composition was measured with an electron beam microanalyzer [EPMA-1720 manufactured by Shimadzu Corporation] and applied to the rust layer (layer thickness: 100 μm). The penetration depth was measured and evaluated according to the following evaluation criteria.
(Double-circle): The permeability | transmittance to a rust is very high, and the coated base material regulator composition osmose | permeates about 100 micrometers from the surface of a rust layer.
◯: Highly permeable to rust, and the coated substrate conditioner composition penetrates about 50 μm from the surface of the rust layer.
Δ: Penetrates rust, but the coated substrate conditioner composition penetrates about 20 μm from the surface of the rust layer.
X: Poor permeability to rust, and most of the substrate conditioner composition is cured on the surface of the rust layer.

<Drying>
The drying property was determined by the degree of semi-curing drying in the curing process after coating.
◎: Semi-cured dry within 12 hours and half ○: Semi-cured dry within 16 hours △: Semi-cured dry within 24 hours ×: Semi-cured dry over 24 hours

<Water resistance>
A water-based substrate conditioner composition was applied, the coated plate after 24 hours was submerged, and the state of the coating film after 72 hours was judged. ◎: No swelling ○: There was 5% or less swelling on the coating film surface △: Coating film There is a bulge of more than 5% and 10% or less on the surface.

<Anti-corrosion>
The anticorrosion property was evaluated based on the cycle corrosion property of JIS K5674.
◎: No blistering or rusting ○: Fluffing or rusting within 2mm width in the crosscut part There are several points of bulging and rusting other than the crosscutting part △: Blistering or rusting of width 2-5mm in the crosscut part 10% or less blistering and rusting other than the cross-cut part ×: Blistering and rusting exceeding 5mm in width at the cross-cutting part.

<Permeability to rust pigment>
In order to confirm the permeability to the rust of the prepared base conditioner composition of the present invention, the following evaluation was performed using the base conditioner compositions of Example 18 and Comparative Example 9.
(Test method)
An aluminum ring having an inner diameter of 3.5 cm is placed on the OHP sheet, and 5 g of iron rust pigment (manufactured by Chemilite Kogyo Co., Ltd.) is placed in the ring, and pressure is applied using MP-35 (manufactured by Shimadzu Corporation) The pellets were pressed and hardened under the conditions of 10 t / cm ² and time: 30 seconds. 0.7 g of the substrate conditioner composition of Example 18 or Comparative Example 9 was applied to the surface of each pellet. Then, after making it dry at room temperature for 24 hours, the permeability to the inside of a pellet was evaluated by lifting a ring. The results are shown in FIG.
A state immediately after application, a portion attached to the ring after lifting the ring after drying for 24 hours (penetrating portion), and a portion remaining on the OHP sheet (non-penetrating portion) are shown.

(result)
Example 18:
When the ring was lifted after drying for 24 hours, both the iron rust pigment and the base preparation composition were adhered to the ring, and the iron rust pigment was slightly adhered to the remaining OHP sheet. That is, it can be seen that the substrate preparation composition of Example 18 sufficiently penetrated into the iron rust pigment pellets and solidified together with the iron rust pigment.
Comparative Example 9:
When the ring was lifted after drying for 24 hours, most of the base preparation composition of Comparative Example 9 was adhered to the ring, and most of the iron rust pigment remained adhered to the OHP sheet. That is, it can be seen that the substrate preparation composition of Comparative Example 9 hardly penetrates into the iron rust pigment pellets and solidifies in the iron rust pigment pellet surface layer.
That is, from the above results, the substrate conditioner composition of Example 18 penetrates into the iron rust pellets and can solidify the rust, but the substrate conditioner composition of Comparative Example 9 is solidified only on the surface layer of the iron rust pellets, It turns out that can hardly be solidified.

That is, the present invention is a two-component mixed-type aqueous base material composition that is applied to a steel material having rust on the surface and contains a main agent (A) and a curing agent (B) ,
The main agent (A) is (A-1) a water-soluble resin or water-dispersible resin having one or more hydroxyl groups and / or carboxyl groups in one molecule, (A-2) an antirust pigment, and (A-3). corrosive ion fixing agent and containing a (a-4) 1 or more selected from the group consisting of silane coupling agents, viscosity at and the temperature 23 ° C. it should be noted is 1~5000mPa · s, also,
The main agent (A) contains the (A-3) corrosive ion fixing agent as an essential component, and the content of the (A-3) corrosive ion fixing agent is 0.1 to 20 mass in the main agent (A). %
The curing agent (B) includes a water-dispersible polyisocyanate resin,
A ratio of a hydroxyl group equivalent in the main agent (A) and an isocyanate group equivalent in the curing agent (B) (isocyanate group equivalent / hydroxyl group equivalent) is 1.0 to 1.7. It is a regulator composition.

The substrate conditioner composition of the present invention is a two-component mixed type containing a main agent (A) and a curing agent (B) described below, and is a water-based substrate conditioner composition. This will be specifically described below.

< Main agent (A) >
The main agent (A) used in the substrate conditioner composition of the present invention includes (A-1) a water-soluble resin or water-dispersible resin having one or more hydroxyl groups and / or carboxyl groups in one molecule, and (A -2) 1 or more types chosen from the group which consists of a rust preventive pigment, (A-3) corrosive ionization fixing agent, and (A-4) silane coupling agent.

< Curing agent (B) >
The curing agent (B) in the present invention includes a water-dispersible polyisocyanate resin. Since this water-dispersible polyisocyanate resin has an isocyanate group, the hydroxyl group or carboxyl group contained in the main agent (A) reacts with the isocyanate group of the curing agent and cures. By using a dispersible polyisocyanate resin, it can be easily mixed with the water-based resin of the main agent (A), and a crosslinked film is formed in the coated rust layer by the reaction of hydroxyl groups, carboxyl groups and isocyanate groups. Therefore, it is preferable in that rust can be fixed in the crosslinked film.
Here, the water-dispersible polyisocyanate resin refers to a polyisocyanate resin that can self-emulsify and disperse in an aqueous medium when stirred in an aqueous medium such as water, and known ones can be used. In the present invention, any of a mixture of a hydrophobic isocyanate and a hydrophilic isocyanate, a mixture of a hydrophobic isocyanate and a hydrophilic dispersant, a polyisocyanate having a hydrophilic group, and the like can be used. The polyisocyanate having a hydrophilic group can be prepared by various methods, for example, a method of introducing an ethylene oxide group, a propylene oxide group or the like, which is a nonionic and hydrophilic functional group, into the polyisocyanate. And a method of introducing a compound containing an ionic group or a latent ionic group (for example, a hydroxyl group, an amino group, a carboxyl group, a sulfonic acid group, a silanol group) into a polyisocyanate.

Hereinafter, the aqueous substrate conditioner composition of the present invention will be specifically described based on Examples , Reference Examples and Comparative Examples, but the present invention is limited to these Examples , Reference Examples and Comparative Examples. is not. In the examples, reference examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified.

[Examples 1 , 3 to 10 , 12 to 13 , 16 to 18, 20 to 27, and 29 to 37 , Reference Examples 2 , 11, 14, 15 , 19, and 28, and Comparative Examples 1 to 9]
First, as shown in Tables 1 to 3, a main agent (A) and a curing agent (B) were prepared. About each of the main ingredient (A) and the hardening | curing agent (B), the viscosity was measured by the below-mentioned method.

<Application of aqueous substrate conditioner composition>
The prepared main agent (A) and curing agent (B) were mixed in accordance with the compositions shown in Tables 1 to 3, respectively. Examples 1 , 3 to 10 , 12 to 13 , 16 to 18, 20 to 27, and 29 to 37 , Reference It was set as the aqueous | water-based base-material regulator composition which concerns on Example 2, 11, 14, 15, 19 and 28, and Comparative Examples 1-9, and this apply | coated to the surface of the said rusting coating board after the said pretreatment, respectively 0.10kg / It was applied by brush so as to m ^2, and then air dried for 1 day under an environment of temperature of 23 ° C.. In addition, the coating of the aqueous | water-based base-material regulator composition which concerns on Example 1 , 3-10, 12-13, 16-18, 20-27, and 29-37 and Reference Examples 2 , 11, 14, 15 , 19, and 28. The viscosity at that time was 5,000 mPa · s or less.
Odor, painting workability, permeability to rust, drying properties, and water resistance were evaluated by the methods described below.

Claims (6)

It is used by applying to a steel material having rust on the surface, and is a two-component mixed-type aqueous base conditioner composition containing (A) a main agent and (B) a curing agent,
The main agent (A) is (A-1) a water-soluble resin or water-dispersible resin having one or more hydroxyl groups and / or carboxyl groups in one molecule, (A-2) an antirust pigment, and (A-3). Containing at least one selected from the group consisting of a corrosive ion fixing agent and (A-4) a silane coupling agent, and having a viscosity at 23 ° C. of 1 to 5000 mPa · s,
The curing agent (B) includes a water-dispersible polyisocyanate resin,
A ratio of a hydroxyl group equivalent in the main agent (A) and an isocyanate group equivalent in the curing agent (B) (isocyanate group equivalent / hydroxyl group equivalent) is 1.0 to 1.7. Conditioner composition.   The component (A-1) is a water-soluble resin or water-dispersible resin having one or more hydroxyl groups in one molecule and having a hydroxyl value of 20 to 200 mgKOH / g. A water-based substrate conditioner composition as described in 1.   The water-based base conditioner composition according to claim 1 or 2, wherein the water-dispersible polyisocyanate resin in the curing agent (B) has a weight average molecular weight of 800 to 7,000.   The main agent (A) contains a corrosive ion fixing agent (A-3), and the content of the corrosive ion fixing agent (A-3) is 0.1 to 20% by mass in the main agent (A). The water-based substrate conditioner composition according to any one of claims 1 to 3, wherein the water-based substrate conditioner composition is provided.   A steel material having rust on its surface is coated with the water-based substrate conditioner composition according to any one of claims 1 to 4, and then an acrylic resin paint, a urethane resin paint, an epoxy resin paint, a chlorinated polyolefin. A steel material having rust on the surface, characterized in that a paint film is formed on the surface of the steel material by coating a paint containing at least one selected from the group consisting of a paint based on silicon, a silicone resin and a fluororesin based paint Painting method.   The water-based substrate conditioner composition according to any one of claims 1 to 4, an acrylic resin-based paint, a urethane resin-based paint, an epoxy resin-based paint, a chlorinated polyolefin-based paint, a silicone resin-based paint, and a fluorine resin-based resin A coated steel material in which a paint containing at least one selected from the group consisting of paints is coated in order on a steel material having rust on the surface.

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