Hardened material removal method and composition for coated film formation

Abstract

To provide a new method that can easily remove hardened materials such as paint and an adhesive adhering onto a coated film.SOLUTION: A hardened material removal method, which includes a step of forming a coated film 21 on a surface of an object 31, can remove a hardened material 22 adhering onto the coated film 21, where the coated film 21 is formed of compositions for coated film formation containing aqueous resin and oil. When an HSP distance between the aqueous resin and the oil is defined as A and an HSP distance between an organic material included in the hardened material 22 and the oil is defined as B, a relational expression of 2<A-B<5 is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for removing a cured product, a composition for forming a coating film, a coating film, and an article provided with a coating film. [Background technology]

[0002] Conventionally, in order to prevent adhesion of dirt and scratches on structures and structural members, a method of protecting the surface of an object such as a structure with an antifouling coating film has been used. For example, Patent Document 1 discloses a coating composition capable of forming a coating film having excellent solvent resistance, recoatability, graffiti removal property, or graffiti prevention property. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4721667 Summary of the Invention [Problem to be solved by the invention]

[0004] In factories and other places, when handling structures protected by antifouling coatings, paints, adhesives, etc. may unintentionally adhere to the surface of the antifouling coating and harden before the timing of repainting the antifouling coating, making it difficult to remove. In this case, it is necessary to repaint the antifouling coating earlier than usual, making this an inefficient method of preventing fouling on structures and other objects.

[0005] Therefore, an object of the present invention is to provide a new method for easily removing a cured product such as a paint or adhesive that has adhered to a coating film, and to provide a coating film-forming composition capable of forming a coating film from which a cured product such as a paint or adhesive can be easily removed, a coating film made of the composition, and an article provided with the coating film. [Means for solving the problem]

[0006] As a result of intensive research to solve the above problems, the present inventor has found that a coating film formed from a coating composition containing an aqueous resin and an oil, wherein the HSP distance between the aqueous resin and the oil and the HSP distance between the organic matter contained in the cured product to be removed and the oil have a predetermined relationship, can easily remove the cured product adhering to the coating film by forming the coating film on the surface of an object, and thus completed the present invention.

[0007] That is, one embodiment of the present invention is a method for removing a cured product adhering to the coating film, including a step of forming the coating film on the surface of an object, wherein the coating film is formed from a coating composition containing an aqueous resin and an oil, and when the HSP distance between the aqueous resin and the oil is A and the HSP distance between the organic matter contained in the cured product and the oil is B, 2 < A - B < 5 is satisfied. Also, one embodiment of the present invention is a coating composition for forming a coating film for removing a cured product adhering to the coating film by forming the coating film on the surface of an object, containing an aqueous resin and an oil, and when the HSP distance between the aqueous resin and the oil is A and the HSP distance between the organic matter contained in the cured product and the oil is B, 2 < A - B < 5 is satisfied.

Advantages of the Invention

[0008] According to the present invention, a new method for easily removing cured products such as paints and adhesives adhering to a coating film can be provided. Further, a coating composition for forming a coating film capable of easily removing cured products such as paints and adhesives, a coating film made of the composition, and an article provided with the coating film can be provided.

Brief Description of the Drawings

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing a state in which a cured product 22 such as a paint or an adhesive adheres to a coating film 21 formed on the surface of an object (article) 31. [Diagram 2]FIG. 2 is a schematic diagram showing a mode in which the oil 23 contained in the coating film 21 bleeds in the direction of the cured product 22 in response to the adhesion of the cured product 22 onto the coating film 21 formed on the surface of the object (article) 31, and the cured product 22 is removed by the intervention of the oil 23 at the interface I between the coating film 21 and the cured product 22.

Mode for Carrying Out the Invention

[0010] In the present specification, "a~b" indicating a range means "a or more and b or less". Also, in the present specification, "weight" and "mass", "weight%" and "mass%" are treated as synonyms, respectively.

[0011] Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below. Also, in the following drawings, members and parts having the same function may be denoted by the same reference numerals and described, and duplicate descriptions may be omitted or simplified. Further, the embodiments shown in the drawings are schematized for clearly explaining the present invention, and do not necessarily accurately represent the size and scale of an actual product.

[0012] <Method for Removing Cured Product> A method according to an embodiment of the present invention (hereinafter also referred to as the present method) is a method for removing a cured product adhering to the coating film, including a step of forming the coating film on the surface of an object, wherein the coating film is formed from a coating film-forming composition containing an aqueous resin and an oil, and when the HSP distance between the aqueous resin and the oil is A and the HSP distance between the organic matter contained in the cured product and the oil is B, 2 < A - B < 5 is satisfied.

[0013] FIG. 1 is a cross-sectional view showing a state in which a cured product 22 of paint, adhesive, etc. is attached onto a coating film 21 formed on the surface of an object (article) 31. A coating film forming composition described later is applied onto the surface of the object (article) 31, and then dried to form the coating film 21. As described above, when the object (article) 31 having the coating film 21 is handled in a factory or the like, the cured product 22 of paint, adhesive, etc. may be attached onto the surface of the coating film 21. In this specification, the ease of removing the cured product 22 of paint, adhesive, etc. from the surface of the coating film 21 is referred to as "ease of cleaning." Note that FIG. 1 illustrates a state in which the cured product 22 is attached to the entire surface of the coating film 21, but the cured product 22 may be attached to only a part of the surface of the coating film 21.

[0014] In this method, it is important to form a coating film on the surface of an object, which is formed from a coating film-forming composition containing a water-based resin and an oil, and in which the HSP distance between the water-based resin and the oil and the HSP distance between the organic matter contained in the cured material to be removed and the oil have the above-mentioned predetermined relationship. The reason why the cured material attached to the coating film can be easily removed is not clear, but it is assumed to be due to the following mechanism of action. That is, when a cured material to be removed adheres to the coating film, the HSP distance (B) between the organic matter contained in the cured material and the oil is closer than the HSP distance (A) between the water-based resin and the oil, and there is a certain degree of distance between them, so that the oil 23 is interposed between the coating film 21 and the cured material 22, as shown in Fig. 2. This means that in response to the adhesion of the cured material 22 onto the coating film 21, an appropriate amount of the oil 23 contained in the coating film 21 bleeds toward the cured material 22, and it is presumed that the oil 23 intervenes at the interface I between the coating film 21 and the cured material 22, thereby exhibiting easy cleaning properties. Note that this method is not limited to the above-mentioned mechanism of action.

[0015] [Paint film] The method includes a step of forming a coating film on a surface of an object. The coating film is formed from a coating film-forming composition containing a water-based resin and an oil. More specifically, the coating film is formed on the surface of the object by applying a coating film-forming composition containing a water-based resin and an oil to the surface of the object and drying it.

[0016] (Water-based resin) The coating film in this method is formed from a coating film-forming composition containing a water-based resin. The water-based resin refers to a state in which the resin is stably dispersed as dispersoid particles in a water-based solvent. The water-based solvent refers to water, a water-soluble organic solvent, or a mixture of these. The water-based resin is more environmentally friendly and may also be easier to work with than a solvent-based resin.

[0017] In this method, the content of the aqueous resin in the coating film is preferably 30 to 99% by mass in terms of resin solids. When the content of the aqueous resin in the coating film is 30% by mass or more in terms of resin solids, the film-forming properties are good. Furthermore, when the content of the aqueous resin in the coating film is 99% by mass or less in terms of resin solids, the oil bleeding is good. The content of the aqueous resin in the coating film is more preferably 50% by mass or more in terms of resin solids, even more preferably 60% by mass or more, particularly preferably 70% by mass or more, and more preferably 98% by mass or less, even more preferably 97% by mass or less, particularly preferably 95% by mass or less.

[0018] The aqueous resin is a resin stably dispersed as dispersoid particles in an aqueous solvent, and various types of resins can be used as long as the HSP distance between the aqueous resin and the oil and the HSP distance between the organic matter contained in the cured material to be removed and the oil satisfy the above-mentioned specified relationship. Examples of the resin components contained in the aqueous resin include polyurethane resins, silicone resins, polyethylene resins, acrylic resins, polystyrene resins, rubber resins, vinyl alkyl ether resins, polyvinyl alcohol resins, polyvinylpyrrolidone resins, polyacrylamide resins, cellulose resins, polyester resins, and fluorine resins. Among them, at least one selected from polyurethane resins, silicone resins, acrylic resins, and polystyrene resins is preferred. The aqueous resin in this method may contain resin components corresponding to two or more of the above. For example, it may contain resin components corresponding to both acrylic resins and polystyrene resins, such as styrene acrylic resins such as Hi-Loss X J-140A (manufactured by Seiko PMC Corporation).

[0019] The polyurethane resin is typically a reaction product of a polyol and a polyisocyanate. As the polyol component, a polymer polyol such as a polycarbonate polyol, a polyacrylic polyol, a polyester polyol, or a polyether polyol is preferably used.

[0020] Representative examples of polycarbonate polyols include reaction products of polyhydric alcohols with phosgene, chloroformate, dialkyl carbonates, or diaryl carbonates; ring-opening polymers of cyclic carbonates (alkylene carbonates, etc.). Specifically, in the reaction products of polyhydric alcohols with phosgene, examples of the polyhydric alcohols that can be used include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, and 1,9-nonanediol. In addition, examples of the alkylene carbonates in the ring-opening polymers of cyclic carbonates include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, and hexamethylene carbonate. The polycarbonate polyol may be any compound having a carbonate bond in the molecule and a hydroxyl group at the end, and may have an ester bond in addition to the carbonate bond.

[0021] Polyacrylic polyol is typically obtained by polymerization of (meth)acrylic acid ester and hydroxyl group-containing monomer. Examples of (meth)acrylic acid ester include methyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, etc. Examples of hydroxyl group-containing monomer include hydroxyalkyl ester of (meth)acrylic acid such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, etc.; (meth)acrylic acid monoester of polyhydric alcohol such as glycerin and trimethylolpropane; N-methylol (meth)acrylamide, etc.

[0022] The polyester polyol is typically obtained by the reaction of a polybasic acid with a polyol. Examples of the polybasic acid include aromatic dicarboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, and tetrahydrophthalic acid; aliphatic dicarboxylic acids such as oxalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, tartaric acid, alkyl succinic acid, linoleic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, and itaconic acid; alicyclic dicarboxylic acids such as hexahydrophthalic acid, tetrahydrophthalic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; and reactive derivatives thereof such as acid anhydrides, alkyl esters, and acid halides.

[0023] Polyether polyols are typically obtained by adding alkylene oxides to polyhydric alcohols through ring-opening polymerization. Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, etc. Examples of alkylene oxides include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, etc.

[0024] Examples of polyisocyanates include aromatic, aliphatic, and alicyclic diisocyanates, as well as dimers and trimers of these diisocyanates. Examples of aromatic, aliphatic, and alicyclic diisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), naphthylene diisocyanate (NDI), phenylene diisocyanate (PPDI), m-tetramethylxylylene diisocyanate (TMXDI), methylcyclohexane diisocyanate (hydrogenated TDI), dicyclohexylmethane diisocyanate (PPDI), and methylcyclohexane diisocyanate (TDI). Examples of the isocyanate include bis(isocyanatomethyl)cyclohexane (hydrogenated XDI), norbornene diisocyanate (NBDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), butane diisocyanate, 2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate. Dimers and trimers of these and polyphenylmethane diisocyanate are also used. Examples of trimers include isocyanurate type, biuret type, and allophanate type, and can be used as appropriate.

[0025] Among these, aliphatic and alicyclic diisocyanates such as methylcyclohexane diisocyanate (hydrogenated TDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexane diisocyanate (hydrogenated PPDI), bis(isocyanatomethyl)cyclohexane (hydrogenated XDI), norbornene diisocyanate (NBDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), hydrogenated 4,4-diphenylmethane diisocyanate (HMDI), butane diisocyanate, 2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate are particularly preferably used.

[0026] These polyisocyanates can be used alone or in combination. The type and combination of polyisocyanates can be appropriately selected from the viewpoints of the properties of the object (article) to be adhered, solubility, reactivity with hydroxyl groups, etc.

[0027] As the polyisocyanate, it is preferable to use at least one diisocyanate selected from the group consisting of hexamethylene diisocyanate (HDI), hydrogenated tolylene diisocyanate (HTDI), hydrogenated 4,4-diphenylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), and hydrogenated xylene diisocyanate (HXDI), and hydrogenated 4,4-diphenylmethane diisocyanate (HMDI) is particularly preferable.

[0028] Among them, the polyurethane resin is particularly preferably a polyurethane resin obtained by reacting a polycarbonate diol as a polyol component with a polyisocyanate. Such a polyurethane resin can be a commercially available product, such as Superflex 420 (SF420, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Superflex 420 is a polyurethane resin obtained by reacting a polycarbonate polyol, particularly hexamethylene carbonate, as a polyol component with an aliphatic or alicyclic diisocyanate, particularly hydrogenated 4,4-diphenylmethane diisocyanate (HMDI), as a polyisocyanate.

[0029] As the silicone-based resin, various known silicone resins can be used. Silicone resins are polymers having a three-dimensional network structure obtained by hydrolyzing and polymerizing organochlorosilanes, and RSiO 1 / 2 Units, RSiO units, RSiO 3 / 2 The R may be a C alkyl group (such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, etc.). 1-6Examples of the silicone resin include monovalent hydrocarbon groups such as alkyl groups, cycloalkyl groups (3- to 8-membered cycloalkyl groups such as cyclopentyl and cyclohexyl groups), and aryl groups (phenyl and naphthyl groups). There are no particular limitations on the silicone resin, but a silicone resin in which 80% or more of all R's are methyl groups is preferred.

[0030] Silicone resins are generally classified into oil type, oil compound type, solution type, emulsion type, self-emulsifying type, etc. Among these, the emulsion type and self-emulsifying type that can be used in combination with water are preferred in the present method, and particularly preferred are emulsion type, especially reactive (self-crosslinking) emulsion type silicone resins that are cured by a crosslinking reaction to form a silicone film.

[0031] The silicone resin may be prepared by a known method, or may be a commercially available emulsion-type silicone resin, etc. Commercially available reactive emulsion-type silicone resins include, for example, POLON-MF-56, KM-2002T, KM-2002L-1, POLON-MF-20, POLON-MF-23, POLON-MF-206, POLON-MWS, and X-51-1318 manufactured by Shin-Etsu Silicones Co., Ltd.

[0032] Examples of polyethylene-based resins include polyethylene (ethylene homopolymer), copolymers of ethylene and propylene, and copolymers of ethylene and an α-olefin other than ethylene.

[0033] The acrylic resin is preferably one obtained by emulsion polymerization of a monomer component containing an alkyl (meth)acrylate, for example.

[0034] Examples of alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and tetradecyl (meth)acrylate. These alkyl (meth)acrylates can be used alone or in combination of two or more. Among them, preferred alkyl (meth)acrylates include n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA).

[0035] In this specification, "(meth)acrylic" means acrylic and / or methacrylic. Acrylic resins include those containing acrylic acid or a derivative thereof as a constituent monomer component, and those containing methacrylic acid or a derivative thereof as a constituent monomer component.

[0036] The proportion of alkyl (meth)acrylate in all monomer components used in the synthesis of the acrylic resin is preferably 70% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more. The upper limit of the proportion of the alkyl (meth)acrylate is not particularly limited, but is usually preferably 99.5% by mass or less (for example, 99% by mass or less). Alternatively, the acrylic resin may be substantially a polymer of only alkyl (meth)acrylate.

[0037] Examples of polystyrene-based resins that can be used include SBS (styrene-butadiene block copolymer), SIS (styrene-isoprene block copolymer), SEBS (styrene-ethylene-butylene-styrene block copolymer), SEPS (styrene-ethylene-propylene-styrene block copolymer), and SEEPS (styrene-ethylene-ethylene-propylene-styrene block copolymer).

[0038] Examples of the rubber-based resin include acrylic rubber, diene rubber, butyl rubber, nitrile rubber, hydrogenated nitrile rubber, fluororubber, silicone rubber, ethylene propylene rubber, chloroprene rubber, urethane rubber, and epichlorohydrin rubber, and it is particularly preferable to use acrylic rubber, diene rubber, and urethane rubber. Examples of the diene-based rubber include natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, and acrylonitrile butadiene rubber, and it is preferable to use styrene butadiene rubber.

[0039] Examples of vinyl alkyl ether resins include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, amyl vinyl ether, and 2-ethylhexyl vinyl ether.

[0040] Examples of polyvinyl alcohol resins include polyvinyl alcohol or its derivatives. Examples of polyvinyl alcohol derivatives include polyvinyl formal, polyvinyl acetal, etc., as well as olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and alkyl esters thereof, and those modified with acrylamide, etc. Only one type of polyvinyl alcohol resin may be used, or two or more types may be used.

[0041] As the polyvinylpyrrolidone-based resin, for example, polyvinylpyrrolidone-based resin (also called PVP-based resin, PVP, etc.) is usually an N-vinyl-2-pyrrolidone-based polymer (a polymer having at least N-vinyl-2-pyrrolidone as a polymerization component). The PVP-based resin is required to have N-vinyl-2-pyrrolidone units, and may have units derived from other monomers (monomers copolymerizable with N-vinyl-2-pyrrolidone) as necessary (or may be modified with other monomers). The other monomer is not particularly limited, and examples thereof include the vinyl ester in the vinyl ester polymer described above, other monomers, etc. The other monomers may be used alone or in combination of two or more. The PVP-based resins may be used alone or in combination of two or more.

[0042] The polyacrylamide resin may be, for example, a nonionic resin obtained by polymerizing polyacrylamide alone, a cationic resin obtained by copolymerizing a compound having a cationic group in a polyacrylamide skeleton, an anionic resin obtained by copolymerizing a compound having an anionic group in a polyacrylamide skeleton, or an amphoteric resin obtained by copolymerizing a compound having a cationic group in a polyacrylamide skeleton with a compound having an anionic group in a polyacrylamide skeleton. The polyacrylamide resin may have either a straight-chain structure or a branched structure.

[0043] Examples of the cellulose-based resin include triacetyl cellulose (TAC) and cellulose-based resins containing lower fatty acid esters as the main component.

[0044] Examples of polyester resins include polyethylene terephthalate (PET) resins, polybutylene terephthalate (PBT) resins, polyethylene naphthalate resins, and polybutylene naphthalate resins.

[0045] Examples of fluorine-based resins include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), and polychlorotrifluoroethylene (PCTFE).

[0046] The water-based resin may contain a compound containing a polar group. Examples of such compounds include the resin containing the polar group, a silane coupling agent, a crosslinking agent, and silicone oil. Examples of the resin containing a polar group include an ionomer, a rosin resin, and a silicone resin.

[0047] The content of the above compound in the resin components in the aqueous resin is preferably 0.1 to 95 mass % relative to the total mass of the resin components, more preferably 0.5 to 60 mass %, even more preferably 0.5 to 40 mass %, particularly preferably 0.5 to 20 mass %, and most preferably 1 to 20 mass %.

[0048] The content of the resin component in the aqueous resin is preferably 5 to 95 mass%, more preferably 10 to 90 mass%, even more preferably 15 to 80 mass%, particularly preferably 20 to 70 mass%, and most preferably 25 to 60 mass%.

[0049] The aqueous resin may be an emulsion, or an emulsion-type resin using a polymer emulsion obtained by emulsion polymerization.

[0050] Examples of emulsion-type resins include emulsions containing the above-mentioned resin components. Emulsion polymerization is carried out by emulsifying a monomer component in water and then carrying out emulsion polymerization in a conventional manner. This prepares an aqueous dispersion (polymer emulsion). In emulsion polymerization, for example, a surfactant (emulsifier), a radical polymerization initiator, and if necessary, a chain transfer agent are appropriately mixed together with the monomer component. More specifically, for example, known emulsion polymerization methods such as a batch charging method (batch polymerization method), a monomer dropping method, and a monomer emulsion dropping method can be adopted.

[0051] In the monomer dropping method and monomer emulsion dropping method, continuous dropping or divided dropping is appropriately selected. These methods can be appropriately combined. The reaction conditions are appropriately selected, but the polymerization temperature is preferably, for example, 40 to 95°C, and the polymerization time is preferably 30 minutes to 24 hours.

[0052] The initiator used in emulsion polymerization can be appropriately selected from conventionally known polymerization initiators. For example, azo-based polymerization initiators such as 2,2'-azobisisobutyronitrile can be preferably used. Other examples of polymerization initiators include persulfates such as potassium persulfate; peroxide-based initiators such as benzoyl peroxide and hydrogen peroxide; substituted ethane-based initiators such as phenyl-substituted ethane; aromatic carbonyl compounds; and the like.

[0053] Further examples of the polymerization initiator include redox initiators that are a combination of a peroxide and a reducing agent. Such polymerization initiators can be used alone or in combination of two or more. The amount of the polymerization initiator used may be a normal amount, and may be 0.005 to 1 part by mass, or 0.01 to 1 part by mass, per 100 parts by mass of the monomer raw material.

[0054] As the emulsifier, any of anionic, nonionic, and cationic emulsifiers can be used. These can be used alone or in combination of two or more. Usually, it is preferable to use anionic or nonionic emulsifiers.

[0055] Examples of the anionic emulsifier include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkyl phenyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, and the like.

[0056] Examples of the nonionic emulsifier include polyoxyethylene alkyl ethers and polyoxyethylene alkyl phenyl ethers.

[0057] A radically polymerizable emulsifier (reactive emulsifier) ​​having a structure in which a radically polymerizable group such as a propenyl group is introduced into the anionic or nonionic emulsifier as described above may be used. Although not particularly limited, from the viewpoint of polymerization stability during synthesis of the resin and storage stability of the adhesive composition, an embodiment in which only an emulsifier having no radically polymerizable group is used may be preferably adopted.

[0058] In the above polymerization, various conventionally known chain transfer agents (which may also be understood as molecular weight regulators or polymerization degree regulators) may be used as necessary. Such chain transfer agents may be, for example, one or more selected from mercaptans such as n-lauryl mercaptan, tert-lauryl mercaptan, glycidyl mercaptan, and 2-mercaptoethanol. Among them, preferred chain transfer agents include n-lauryl mercaptan and tert-lauryl mercaptan.

[0059] When a chain transfer agent is used in the polymerization of the monomer raw material, the amount of the agent used is not particularly limited. For example, the amount can be 0.001 to 0.5 parts by mass, and usually, 0.01 to 0.1 parts by mass is preferable, based on 100 parts by mass of the monomer raw material.

[0060] The Mw of the resulting resin is typically 10×10 4 or more, usually 20×10 4From the viewpoint of achieving a good balance between adhesive strength and cohesive strength, Mw is 30×10 4 It is preferable that the value is 40×10 or more. 4 More preferably, it is 50×10 or more. 4 The upper limit of Mw is not particularly limited, and may be, for example, 500×10 4 Below, typically 200×10 4 Less than or equal to 150×10 4 It can be the following:

[0061] Mw can be adjusted, for example, by the type and amount of polymerization initiator, polymerization temperature, type and amount of emulsifier, whether or not a chain transfer agent is used and the type and amount of a chain transfer agent if used, the composition of the monomer raw material, the type and degree of crosslinking (gel fraction), etc.

[0062] (oil) The coating film in this method is formed from a coating film-forming composition containing oil. As described above, in this method, in response to the adhesion of the cured material to be removed on the coating film, the oil moderately bleeds toward the cured material, and is present at the interface between the coating film and the cured material, which is thought to provide easy cleaning. That is, in this method, it is preferable that the oil bleeds from the coating film to remove the cured material.

[0063] In this method, the oil content in the coating film is preferably 0.1 to 50% by mass. When the oil content in the coating film is 0.1% by mass or more, the oil bleeding is good. Furthermore, when the oil content in the coating film is 50% by mass or less, the film-forming properties of the coating film are good. The oil content in the coating film is more preferably 0.5% by mass or more, even more preferably 1% by mass or more, particularly preferably 5% by mass or more, and more preferably 40% by mass or less, even more preferably 20% by mass or less, particularly preferably 10% by mass or less.

[0064] As for the oil, various types of oil can be used as long as the HSP distance between the water-based resin and the oil and the HSP distance between the organic matter contained in the cured material to be removed and the oil have a specified relationship, as described below.

[0065] Examples of the oil include silicone oil, hydrocarbon oil, polyether oil, fluorine oil, ester oil, phosphorus compound oil, mineral oil, etc. Among them, at least one oil selected from silicone oil, hydrocarbon oil, and polyether oil is preferable.

[0066] Silicone oils are broadly classified into reactive silicone oils and non-reactive silicone oils. Examples of reactive silicone oils include side chain type, both end type, one end type, and both end type of side chain. Examples of modified types include, in the case of side chain type, amino modified type, epoxy modified type, carbinol modified type, mercapto modified type, carboxyl modified type, and hydrogen modified type. Examples of both end types include amino modified type, epoxy modified type, carbinol modified type, methacryl modified type, polyether modified type, mercapto modified type, carboxyl modified type, silanol modified type, acrylic modified type, and carboxylic anhydride modified type. Examples of one end type include epoxy modified type, carbinol modified type, diol modified type, methacryl modified type, and carboxyl modified type. Examples of both end type of side chain include, for example, side chain amino / both end methoxy modified type, and epoxy modified type. Examples of the non-reactive silicone oil include side chain type and both end type. Examples of the modified type include, in the case of the side chain type, polyether modified type, aralkyl modified type, fluoroalkyl modified type, long chain alkyl modified type, higher fatty acid ester modified type, higher fatty acid amide modified type, phenyl modified type, etc. In the case of the both end type, examples of the modified type include polyether modified type, etc.

[0067] The silicone oil is preferably a reactive silicone oil, which, as described above, has reactive groups at both ends, one end, and at least one of the side chains of the main chain made of siloxane bonds.

[0068] The coating film formed by the composition containing reactive silicone oil has an increased water contact angle and is balanced by the reactive silicone oil, and is therefore particularly easy to clean from oily stains such as paint. This is presumably because the reactive silicone oil is induced by the functional groups of the oily stains and migrates to the surface, resulting in the oil being present at the interface between the oily stains and the coating film.

[0069] The main chain (main skeleton) consisting of the above-mentioned siloxane bond is not limited, but poly(dimethylsiloxane) and the like can be preferably used. In addition, the reactive group is not particularly limited as long as it is an atomic group that shows polar reactivity, and examples thereof include functional groups containing polar oxygen atoms, nitrogen atoms, sulfur atoms, etc. that are attracted to hydroxyl groups and the like present on the oily stain side. Specific examples thereof include hydrogen atoms, hydroxyl groups, amino groups, aminoalkyl groups, carbinol groups, epoxy groups, carboxyl groups, mercapto groups, etc. These reactive groups may be present alone or in combination of two or more types.

[0070] Among these, as reactive silicone oils, amino-modified silicone oils having an amino group or an aminoalkyl group as a reactive group, epoxy-modified silicone oils having an epoxy group as a reactive group, and mercapto-modified silicone oils having a mercapto group as a reactive group are preferred from the viewpoint of ease of cleaning paint, which is an oily stain, and amino-modified silicone oils are particularly preferred.

[0071] Amino-modified silicone oil is a silicone oil in which some of the methyl groups of the silicone oil are replaced with amino groups or aminoalkyl groups. The modified site may be a side chain, one end, both ends, or both ends of the side chain. It may also be an emulsion type.

[0072] As the amino-modified silicone oil, a commercially available amino-modified silicone oil can be used as it is. In particular, it is preferable to use an amino-modified silicone oil represented by the following general formula (1). By using the amino-modified silicone oil represented by this formula (1), high reliability can be obtained.

[0073] [ka]

[0074] In the above formula (1), R1, R2, and R3 are amino-modified alkyl groups or amino groups, for example, -C3H6-NH2, -C6H4-NH2, -C3H6-NH-C2H4-NH2, -C3H6-NH-CH 3、 -NH2, etc. R1, R2, and R3 may be the same or different from each other. R1, R2, and R3 may contain one or more of an alkyl group, an epoxy group, a carboxyl group, a methacryl group, a carbinol group, a hydroxyl group, a mercapto group, a polyether group, a phenyl group, a fluoroalkyl group, an aralkyl group, and hydrogen.

[0075] In the above formula (1), the repeat number m is a positive number from 0 to 50, and the repeat number n is a positive number from 0 to 50. Particularly preferably, m is in the range of 0-20, and n is in the range of 0-20.

[0076] Furthermore, as the amino-modified silicone oil represented by the above formula (1), a dimethylpolysiloxane modified at both ends with aminopropyl groups, in which m=0 to 40 and n=0 to 40 in formula (1), is particularly preferably used. Among these, a dimethylpolysiloxane modified at both ends with aminopropyl groups, in which m=0 to 20 and n=0 to 20 in formula (1), is particularly preferably used.

[0077] The amino-modified silicone oil represented by the above general formula (1) or the like can be obtained by a conventionally known production method.

[0078] Examples of amino-modified silicone oils include KF-868, KF-865, KF-864, KF-859, KF-393, KF-860, KF-877, KF-880, KF-8004, KF-8002, KF-8005, KF-867, X-22-3820W, KF-869, and KF-861 manufactured by Shin-Etsu Chemical Co., Ltd. ,X-22-3939A,PAM-E,KF-8010,X-22-161A,X-22-161B,KF-8012,KF-8008,X-22-1660B-3,KF-857,KF-8001,KF-862,X-22-9192,KF-858,BY16-205,FZ-37 manufactured by Toray Dow Coating Co., Ltd. 60, SF8417, BY16-849, BY16-892, FZ-3785, BY16-872, BY16-213, BY16-203, BY16-898, BY16-890, BY16-891, BY16-893, BY16-871, BY16-853U, Chisso; FM-3311, FM-3321, FM-3 325, Momentive Performance Materials' TSF4702, TSF4703, TSF4704, TSF4705, TSF4706, TSF4707, TSF4708, TSF4709, XF42-B1989, XF42-B8922, XF42-C0330, XF49-C1109, SILSOFT Examples of such silicone rubbers include WACKER L652, WACKER L653, WACKER L655, WACKER L656, WACKER FINISH WR1100, WACKER FINISH WR1200, WACKER FINISH WR1300, WACKER FINISH WR1600, WACKER FINISH WT1250, and WACKER FINISH WT1650 manufactured by Wacker Asahi Kasei Silicones.

[0079] Examples of emulsion types include POLON-MF-14, POLON-MF-14E, POLON-MF-14EC, POLON-MF-29, POLON-MF-39, POLON-MF-44, POLON-MF-52, KM-907, X-52-2265, POLON-MF-51, KM-9771, and POLON-MF-63 manufactured by Shin-Etsu Chemical Co., Ltd., FZ-4632, FZ-4635, FZ-4640, FZ-4645, FZ-4658, FZ-4671, and FZ-4678 manufactured by Junker Chemical Japan, and DOWSILtm FZ-4634 EX, DOWSILtm FZ-4658, and DOWSILtm SM 8709 SR manufactured by Dow Coating Toray Co., Ltd. Emulsion, SM8704C / SM8904, WACKER (registered trademark) FINISH CT 45 E manufactured by Wacker Asahi Kasei Silicone Co., Ltd., and the like.

[0080] Epoxy-modified silicone oil is a silicone oil in which some of the methyl groups of the silicone oil are replaced with epoxy groups. The modified site may be a side chain, one end, both ends, or both ends of the side chain.

[0081] As the epoxy-modified silicone oil, a commercially available epoxy-modified silicone oil can be used as it is. Examples of epoxy-modified silicone oils include X-51-1264, POLON-MF-18T, X-22-343, KF-101, KF-1001, X-22-2000, X-22-2046, KF-102, X-22-163, KF-105, X-22-163A, X-22-163B, X-22-163C, X-22-169AS, X-22-169B, X-22-173BX, X-22-173DX, and X-22-9002 manufactured by Shin-Etsu Chemical Co., Ltd., and DOWSILtm BY 22-818 EX Emulsion, DOWSILtm BY 22-893, DOWSILtm FZ-4602, and DOWSILtm SM manufactured by Dow Toray Co., Ltd. 8716 EX Emulsion, etc.

[0082] Mercapto-modified silicone oil is a silicone oil having a structure in which some of the methyl groups of the silicone oil are replaced with mercapto groups. The modified site may be a side chain, one end, both ends, or both ends of the side chain.

[0083] As the mercapto-modified silicone oil, a commercially available mercapto-modified silicone oil can be used as it is. Examples of the mercapto-modified silicone oil include KM-9769, KF-2001, KF-2004, X-22-167B, and X-22-167C manufactured by Shin-Etsu Chemical Co., Ltd.

[0084] Polyether-modified silicone oils can also be preferably used as silicone oils. The polyether-modified silicone oils may be included in the reactive silicone oils. Examples of polyether-modified silicone oils include those manufactured by Shin-Etsu Silicones under the trade names "KF-6011" (HLB: 14.5), "KF-6011P" (HLB: 14.5), "KF-6012" (HLB: 7.0), "KF-6013" (HLB: 10.0), "KF-6015" (HLB: 4.5), "KF-6016" (HLB: 4.5), "KF-6017" (HLB: 4.5), and "KF-6017P" (HLB: 4.5). " (HLB:4.5), "KF-6043" (HLB:14.5), "KF-6004" (HLB:9.0), KF351A, KF352A, KF353, KF354L, KF355A, KF615A, KF945, KF-640, KF-642, KF-643, KF-644, KF-6020, KF-6204, X22-4515 and other side-chain type (straight-chain type) polyether modified silicone oils; Shin-Etsu Silicone Side chain type (branched chain type) polyether modified silicone oils such as "KF-6028" (HLB: 4.0) and "KF-6028P" (HLB: 4.0) manufactured by Shin-Etsu Silicone Co., Ltd.; side chain type (branched chain type, alkyl co-modified type) polyether modified silicone oils such as "KF-6038" (HLB: 3.0) manufactured by Shin-Etsu Silicone Co., Ltd.; "SilwetL-7602" (HLB: 7.3) and " Examples of such polysiloxanes include SilwetL-7600 (HLB: 14.3), SilwetL-7604 (HLB: 10.6), SilwetL-7622 (HLB: 8), SilwetL-7657 (HLB: 12.9), Dow Corning Toray's product name "FZ-2162" (HLB: 14), Momentive's product names "TSF4446" (HLB: 6.2), "TSF4440" (HLB: 14), etc. Also, BYK's product name "BYK331" etc. can be suitably used.

[0085] Examples of hydrocarbon oils include normal paraffin, isoparaffin, polybutene, polyisobutylene, 1-decene oligomer, 1-decene and ethylene co-oligomer, monoalkylbenzene, dialkylbenzene, polyalkylbenzene, monoalkylnaphthalene, dialkylnaphthalene, and polyalkylnaphthalene. Examples of polyether oils include polyethylene glycol, polypropylene glycol, polyethylene glycol monoether, polypropylene glycol monoether, monoalkyl triphenyl ether, alkyl diphenyl ether, dialkyl diphenyl ether, tetraphenyl ether, pentaphenyl ether, monoalkyl tetraphenyl ether, dialkyl tetraphenyl ether, butyl glycidyl ether, and lauryl glycidyl ether. Examples of fluorine oils include fluoroethylene, trifluoroethylene chloride, perfluoropolyether, and perfluoropolyalkyl ether. Examples of ester oils include diester oils such as dibutyl sebacate, di(2-ethylhexyl) sebacate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, diisotridecyl adipate, ditridecyl glutarate, and methyl acetyl ricinoleate; trioctyl trimellitate, tridecyl trimellitate, tetraoctyl pyromellitate, trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, pentaerythritol pelargonate, and complex ester oils which are oligoesters of mixed fatty acids of monobasic and dibasic acids and polyhydric alcohols. The amide-based oil is, for example, one or more oils containing at least one amide functional group in its structure, such as DMF. Examples of mineral oils include paraffinic process oil, aromatic process oil, and naphthenic process oil.

[0086] (Other ingredients) The coating film and the coating film-forming composition in the present method may contain any other appropriate additives within the scope of not impairing the effects of the present invention. Examples of other additives include ultraviolet absorbers, light stabilizers, antioxidants, antiaging agents, antistatic agents, pigments, dyes, leveling agents, thickeners, etc.

[0087] [Cured product] The cured material to be removed in this method means a material in which at least a resin-containing substance is in a cured state. The ratio of the resin in the solid content of the cured product is preferably 10% by mass or more. The present method shows particularly high ease of cleaning for a cured product having a ratio of the resin in the solid content in the above range. The ratio of the resin in the solid content of the cured product is more preferably 30% by mass or more, particularly preferably 50% by mass or more, and is, for example, 99% by mass or less.

[0088] Specific examples of the cured product include water-based paints, solvent-based paints, and solvent-based pastes.

[0089] The water-based paint refers to a paint that contains water as a main solvent, and examples thereof include acrylic paint, polyester paint, EVA paint, urethane paint, fluorine paint, silicone paint, and polymer cement paint.

[0090] Solvent-based paint is a term that is contrasted with water-based paint, and refers to paint that does not substantially contain water as a solvent, and mainly contains organic solvents. Examples of organic solvents include known ones, and are not particularly limited. Examples of organic solvents include toluene, methyl ethyl ketone (MEK), cyclohexanone, Solvesso, isophorone, xylene, methyl isobutyl ketone (MIBK), ethyl acetate, propyl acetate, butyl acetate, and isopropyl alcohol (IPA). Examples of solvent-based paints include acrylic resin paints, epoxy resin paints, chlorinated rubber paints, alkyd resin paints, phenolic resin paints, and synthetic rubber paints.

[0091] The solvent-based paste is obtained by dissolving a polymer in an organic solvent and solidifies by evaporating the organic solvent. Examples of the solvent-based paste include solvent-based adhesives and solvent-based conductive pastes.

[0092] In the solvent-based adhesive, examples of the polymer include chloroprene rubber, styrene-butadiene rubber, nitrile rubber, natural rubber, vinyl chloride resin, vinyl acetate resin, (meth)acrylic resin, urethane resin, and the like. The organic solvent is not particularly limited, and examples thereof include toluene, normal hexane, ethyl acetate, methyl ethyl ketone, acetone, methanol, tetrahydrofuran, xylene, cyclohexanone, and the like.

[0093] In the solvent-based conductive paste, examples of the polymer include polyester, polyurethane, epoxy resin, phenol resin, acrylic resin, vinyl resin, and the like. The organic solvent is not particularly limited, and examples thereof include toluene, normal hexane, ethyl acetate, methyl ethyl ketone, acetone, methanol, tetrahydrofuran, xylene, cyclohexanone, butyl carbitol, butyl carbitol acetate, methyl ethyl ketone, isophorone, α-terpineol, and the like. The solvent-based conductive paste further contains conductive particles. Examples of the conductive particles include noble metal powders such as Ag, non-noble metal powders such as Ni and Cu, conductive carbon black, graphite fine powder, composite metal powder, and the like.

[0094] [HSP value, HSP distance] In this method, when the HSP distance between the aqueous resin and the oil is A and the HSP distance between the organic substance contained in the cured product to be removed and the oil is B, it is important to satisfy 2 < A - B < 5. As described above, since the difference between A - B, that is, the HSP distance between the organic substance contained in the cured product to be removed and the oil and the HSP distance between the aqueous resin and the oil, is within the above range, an appropriate amount of oil in the coating film bleeds in the direction of the cured product, and it is considered that easy cleanability is exhibited by the presence of oil at the interface between the coating film and the cured product.

[0095] The HSP value means the Hansen solubility parameter, which is the solubility parameter δTot introduced by Hildebrand divided into three components: the dispersion term δD, the polarization term δP, and the hydrogen bond term δH. δD indicates the energy derived from the dispersion force between molecules. δP indicates the energy derived from the polar force between molecules. δH indicates the energy derived from the hydrogen bond force between molecules. The relationship between δTot, δD, δP, and δH is as follows: 2 = δD 2 +δP 2 +δH 2 The units of each component are usually MPa. 1 / 2 The three components above define a point (vector) in a three-dimensional space known as Hansen's space. The HSP distance between material α and material β is the distance between the point (D α , P α , H α ) and the point corresponding to material β (D β , P β , H β ) and is expressed by the formula: {4 × (δD α -δD β ) 2 +(δP α -δP β ) 2 +(δH α -δH β ) 2} 1 / 2The Hansen solubility parameters are disclosed in "Hansen Solubility Parameters; A Users Handbook (CRC Press, 2007)". The δD, δP and δH of a polymer can be determined by calculation based on the structural units of the polymer and the content of the units in the polymer, using known software such as HSPiP (version 5). More specifically, the δD, δP and δH of each structural unit can be calculated individually, and the weighted average values ​​obtained by weighting the calculated δD, δP and δH by the content of the units can be used as the δD, δP and δH of the polymer. However, the calculation is performed at a temperature of 23°C. The calculated values ​​of δD, δP and δH may differ slightly depending on the software used, but the difference is usually negligible when determining the HSP distance.

[0096] In this method, the above AB is preferably 2 or more, more preferably 2.5 or more, and even more preferably 3 or more, and is preferably 5 or less, more preferably 4.5 or less, and even more preferably 4 or less. In the present method, the above A is preferably 5-20, more preferably 6-19, and further preferably 7-18. In the present method, the above B is preferably 1-15, more preferably 2-14, and further preferably 3-13.

[0097] In the HSP values ​​of the organic substances contained in the cured material to be removed, ΔD is preferably 15-20, ΔP is preferably 0.1-5, ΔH is preferably 0.5-5, and ΔTot is preferably 15-23.

[0098] In the HSP value of the above aqueous resin, ΔD is preferably 12-20, ΔP is preferably 0.5-10, ΔH is preferably 0.5-10, and ΔTot is preferably 12-23.

[0099] In the HSP value of the oil, ΔD is preferably 12-20, ΔP is preferably 0.1-15, ΔH is preferably 0.5-15, and ΔTot is preferably 13-25.

[0100] [Coating film formation method] The coating film in this method can be formed by applying a coating film-forming composition containing a water-based resin and an oil to the surface of the object (article) as the adherend, which will be described later, and drying it. A highly uniform coating film can be obtained even when dried at room temperature (25°C).

[0101] The coating method can be directly applied to the surface of any object (article) to be adhered by a known coating method such as spraying, brushing, roller, curtain flow, roll, dip, or coater.

[0102] The thickness of the coating film may be any appropriate thickness depending on the application, the environment of use, etc. The thickness of the coating film is preferably 50 μm to 1000 μm, more preferably 80 μm to 500 μm. If the thickness of the coating film is 50 μm or more, the effect of protecting the object (article) that is the adherend can be sufficiently obtained. Also, if the thickness of the coating film is 1000 μm or less, the work efficiency when forming the coating film is excellent. The thickness of the coating film can be measured, for example, using RI-205 manufactured by PEAKOCK.

[0103] Specific examples of objects (articles) to be adhered include metal products, wood products, plastic products, glass products, medical parts (e.g., catheters, stents, gloves, tweezers, containers, guides, trays, etc.), paint-related parts (e.g., robot arms, paint booths, hangers, covering materials, ovens, etc.), buildings (interior and exterior wall surfaces, floors, and ceiling surfaces), electronic devices, transportation equipment (e.g., automobiles, motorcycles, railway vehicles, and ships, etc.), and various other structures, as well as the structural members that make up these structures.

[0104] <Composition for coating film formation> As described above, the coating film-forming composition of one embodiment of the present invention (hereinafter also referred to as this composition) can be applied to the surface of an object (article) 31 and then dried to form a coating film, and contains the above-mentioned water-based resin and the above-mentioned oil, and may also contain other components as required.

[0105] In the present composition, the content of the water-based resin is preferably 30 to 99% by mass in terms of resin solids. When the content of the water-based resin in the present composition is 30% by mass or more in terms of resin solids, the film-forming properties of the coating film are good. Furthermore, when the content of the water-based resin in the present composition is 99% by mass or less in terms of resin solids, oil bleeding can be achieved. The content of the water-based resin in the present composition is more preferably 50% by mass or more in terms of resin solids, even more preferably 60% by mass or more, particularly preferably 70% by mass or more, and more preferably 98% by mass or less, even more preferably 97% by mass or less, particularly preferably 95% by mass or less.

[0106] In the present composition, the content of the oil is preferably 1 to 50 parts by mass relative to 100 parts by mass of the resin solid content of the water-based resin. When the content of the oil in the present composition is 1 part by mass or more, the oil bleeding is good. Also, when the content of the oil in the present composition is 50 parts by mass or less, the film-forming properties of the coating film are good. The content of the oil in the present composition is more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, particularly preferably 7 parts by mass or more, and more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less.

[0107] <Coating film> The coating film of the present embodiment is made of the above-mentioned coating film-forming composition, and has excellent surface cleanability. The method for forming the coating film on the surface of an object is as described above.

[0108] <Articles with coating film> The article provided with the coating film of this embodiment is provided with the above-described coating film. By applying the above coating film-forming composition to an object (article) as the adherend and drying it, an article provided with a coating film can be obtained. A highly uniform coating film can be obtained even by drying at room temperature (25°C). The type of the object (article) as the adherend is as described above.

[0109] As described above, the following matters are disclosed in the specification of the present application. (1) A method for removing a cured product adhered to the coating film, including a step of forming a coating film on the surface of an object, wherein the coating film is formed from a coating film-forming composition containing an aqueous resin and an oil, and when the HSP distance between the aqueous resin and the oil is A, and the HSP distance between the organic matter contained in the cured product and the oil is B, 2 < A - B < 5 is satisfied. Method. (2) The method according to (1) above, wherein the oil bleeds from the coating film to remove the cured product. (3) The method according to (1) or (2) above, wherein the proportion of the resin in the solid content of the cured product is 10% by mass or more. (4) The method according to any one of (1) to (3) above, wherein the aqueous resin is at least one resin selected from a polyurethane resin, a silicone resin, an acrylic resin, and a polystyrene resin. (5) The method according to any one of (1) to (4) above, wherein the oil is at least one oil selected from a silicone oil, a hydrocarbon oil, and a polyether oil. (6) A coating film-forming composition for removing a cured product adhered to the coating film by forming a coating film on the surface of an object, containing an aqueous resin and an oil, and when the HSP distance between the aqueous resin and the oil is A, and the HSP distance between the organic matter contained in the cured product and the oil is B, 2 < A - B < 5 is satisfied. Coating film-forming composition. (7) A coating film comprising the coating film-forming composition according to (6) above. An article provided with the coating film according to (7) above.

Example

[0110] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples in any way. In the following, "part" means "part by mass".

[0111] <HSP value, HSP distance> The HSP values (δD, δP, δH, δTot) of each component and each HSP distance were calculated by the method described above. HSPiP (version 5) was used for the software. The HSP values (δD, δP, δH, δTot) of each component are shown in Table 1. Also, each HSP distance is shown in Tables 3 and 4 described later.

[0112]

Table 1

[0113] <Composition of cured product> Table 2 shows the composition of the cured product to be removed, which is used in the easy-to-clean evaluation test described later.

[0114]

Table 2

[0115] <Easy-to-clean evaluation test> The easy-to-clean evaluation test was conducted according to the following procedure. First, on PET, the coating film-forming composition of each example and comparative example was applied with an applicator to a liquid film thickness of 200 μm and dried at room temperature for 1 day to form a coating film on PET. Subsequently, in order to form a cured product on the coating film, each substance described in Tables 3 and 4 was adhered with a brush so that the thickness of the obtained cured product was about 3.0 mm, and dried at room temperature for 1 day to obtain a test sample with a cured product adhered on the coating film. For each test sample, while applying appropriate pressure, the cured product to be removed was rubbed by placing a hand on the end of the cured product to be removed so that the coating film did not peel off from the PET and only the cured product on the coating film peeled off from the coating film. As a result, evaluation was made such that if the cured product peeled off at the interface between the coating film and the cured product, it was marked as ○, and if the cured product remained attached to the coating film and did not peel off, it was marked as ×.

[0116] <Preparation of Coating Composition for Film Formation> (Example 1) SF420 (100 parts (hereinafter, converted with the resin solid content weight as 100 parts)) and POLON-MF-14EC (7.5 parts) were stirred at 3000 rpm for 3 minutes using a homodisper (Lab Revolution, manufactured by PRIMIX Corporation) to obtain the coating composition for film formation of Example 1.

[0117] (Examples 2 - 5, Comparative Examples 1 - 17) Coating compositions for film formation of Examples 2 - 5 and Comparative Examples 1 - 17 were obtained in the same manner as in Example 1, except that the types and contents of the respective components were changed as shown in Tables 3 and 4.

[0118] Note that the blanks in Tables 3 and 4 mean that the corresponding component is not included.

[0119]

Table 3

[0120]

Table 4

[0121] As shown in Table 3 above, in Examples 1 and 2, since 2 < A - B < 5 was satisfied, the cured products of the aqueous paint to be removed could be easily peeled off. On the other hand, in Comparative Examples 1 - 6, since 2 < A - B < 5 was not satisfied, the cured products of the aqueous paint to be removed could not be peeled off. Also, as shown in Table 3 above, since Example 3 satisfied 2 < A - B < 5, the cured product of the solvent-based paint to be removed could be easily peeled off. On the other hand, since Comparative Examples 7 to 10 did not satisfy 2 < A - B < 5, the cured product of the solvent-based paint to be removed could not be peeled off. Also, as shown in Table 4 above, since Examples 4 and 5 satisfied 2 < A - B < 5, the cured product of the solvent-based adhesive to be removed could be easily peeled off. On the other hand, since Comparative Examples 11 to 13 did not satisfy 2 < A - B < 5, the cured product of the solvent-based adhesive to be removed could not be peeled off. Also, as shown in Table 4 above, since Comparative Examples 14 to 17 did not satisfy 2 < A - B < 5, the cured product of the solvent-based paste to be removed could not be peeled off.

[0122] As described above, various embodiments have been described with reference to the drawings. Needless to say, the present invention is not limited to such examples. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it is naturally understood that those also belong to the technical scope of the present invention. Also, within the scope not departing from the gist of the invention, the components in the above embodiments may be arbitrarily combined.

Explanation of Reference Numerals

[0123] 21 Coating film 22 Cured product 23 Oil 31 Object (article)

Claims

1. A method for removing a cured material adhered to a coating film, comprising the steps of forming a coating film on a surface of an object, The coating film is formed from a coating film-forming composition containing a water-based resin and an oil, When the HSP distance between the aqueous resin and the oil is A and the HSP distance between the organic matter contained in the cured material and the oil is B, 2<A-B<5 is satisfied. method.

2. The method of claim 1 , wherein the oil bleeds from the coating and removes the cured product.

3. The method according to claim 1 or 2, wherein the ratio of the resin in the solid content of the cured product is 10 mass % or more.

4. The method according to claim 1 or 2, wherein the water-based resin is at least one resin selected from the group consisting of polyurethane-based resins, silicone-based resins, acrylic-based resins, and polystyrene-based resins.

5. The method according to claim 1 or 2, wherein the oil is at least one oil selected from the group consisting of silicone oil, hydrocarbon-based oil, and polyether-based oil.

6. A coating film-forming composition for forming a coating film on a surface of an object and removing a cured material adhered to the coating film, comprising: Contains water-based resin and oil, When the HSP distance between the aqueous resin and the oil is A and the HSP distance between the organic matter contained in the cured material and the oil is B, 2<A-B<5 is satisfied. A composition for forming a coating film.

7. A coating film comprising the coating film-forming composition according to claim 6.

8. An article comprising the coating of claim 7.

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