WO2019044904A1 - Precoating agent for peeling coating film, precoating liquid for peeling coating film and method for peeling coating film - Google Patents

Abstract

The present invention relates to a pre-coating agent for peeling a coating film, the pre-coating agent being able to peel and remove an unnecessary coating film in a convenient, safe and also sufficient manner, and capable of forming, on a , a pre-coating film having excellent persistence. The present invention relates to a pre-coating agent which is intended to peel a coating film and which comprises, as binder, an acrylic polymer partially containing an acrylate monomer and / or an oil-modified alkyd resin, and a wax.

Description

Precoating agent for coating film peeling, precoating solution for coating film peeling and coating film peeling method

The present invention relates to a precoat agent for coating film release, a precoat solution for film coating release, and a method for peeling a coating film.

Coating films made of paint lines such as automobile bodies etc., walls of painting booths, floors (grating etc.), painting stands etc., paint mist and / or suspended particles that were scattered in the painting process are Film) is formed. These unwanted coatings need to be removed by regular cleaning and cleaning. If the film is used without removing the unnecessary coating, for example, dust is scattered from the unnecessary coating during coating, and the scattered dust reattaches to the coating, which causes an increase in the coating yield (defect ratio). . In addition, during regular maintenance of the painting area, it interferes with the work of the workers.

Physical cleaning methods and chemical cleaning methods are known as methods for removing unwanted coatings deposited or deposited on the walls, floor, coating table, etc. of painting lines and booths. For example, in the physical cleaning method, ultrahigh pressure water (for example, about 1000 to 3000 kgf / cm ² ) is applied to a wall surface, a floor, a coating table or the like to peel off an unnecessary coating film. Also, for example, in a chemical cleaning method, a release agent is applied to a wall surface, a floor, a coating table or the like to peel off unnecessary coating films or the like.

However, employing physical cleaning methods has resulted in the following problems:
・ The equipment cost for producing super high pressure water was huge;
• The application of equipment producing ultra high pressure water caused noise and safety problems;
-Unnecessary coating films could not be removed sufficiently even by applying ultra-high pressure water.
Also, for example, the use of chemical cleaning resulted in the following problems:
The use of release agents caused safety problems;
-The processing was complicated because the number of processing steps such as the application step, the peeling step and the water washing step was relatively large, and the processing time was relatively long.

Therefore, by coating a predetermined coating on the surface of an article that does not require painting with paint, such as a wall, floor, painting table, etc. Techniques have been disclosed which allow peeling and removal even when attached (Patent Documents 1 and 2).

Patent No. 4011675 Patent No. 4748972

However, in Patent Document 1, even if the precoat film is formed in advance, the unnecessary coating film may not be sufficiently removed. Immediately after the formation of the precoat film, even if the unnecessary coating film can be sufficiently removed, the precoat film is easily dissolved in water and does not remain on the base material such as the lid material, so by forming the precoat film once. There is a problem that the unnecessary coating can not be removed repeatedly. In addition, when forming a precoat film, there is a problem that the coating needs to be heated by heating to a temperature higher than the melting point (for example, 90 ° C.) of the components contained in the precoat agent used. The In patent document 2, since special metal oxides, such as a zirconium oxide, are used, there existed a problem in waste water treatment and the handling of a chemical substance.

The present invention can be applied to the surface at (1) normal temperature, and (2) does not contain special metal oxides etc., and (3) Remaining property of the formed precoat film on the substrate It is an object of the present invention to provide a precoat agent for paint film peeling, which is excellent in water resistance, and (4) enables unnecessary, easy and safe and sufficient peeling and removal of a paint film.

The present invention relates to a precoat agent for coating removal, which comprises, as a binder, an acrylic polymer and / or an oil-modified alkyd resin partially containing an acrylate monomer, and a wax.

The precoat agent for coating film removal of the present invention is applied as a precoat solution to the surface of an article (for example, the surface of an article for which contamination with a paint is desired to be avoided) such as wall surface, floor, coating table etc. By pre-forming a precoat film, without using a composition containing ultrahigh pressure water, a release agent and a special metal oxide, etc., the unnecessary coating film is peeled simply and safely and sufficiently it can.
The precoat film by the precoat agent for film peeling of this invention is excellent in the retentivity to a base material and water resistance.

[Precoat agent for paint film peeling]
The precoat agent for coating film removal (hereinafter simply referred to as "precoat agent") of the present invention comprises a binder and a wax. When the pre-coating agent contains a binder in combination with a wax, the removability of the pre-coating film formed using the pre-coating agent and the remaining property to the substrate are sufficiently improved. When the precoat agent does not contain a binder, at least one of the removability of the precoat film and the residual property to the substrate is reduced.

<Binder>
The binder is at least one polymer selected from the group consisting of an acrylic polymer partially containing an acrylate monomer, and an oil-modified alkyd resin. That is, the binder comprises at least an acrylic polymer and / or an oil modified alkyd resin. Accordingly, the precoating agent of the present invention includes the precoating agent according to the first to third embodiments shown below:
The precoating agent according to the first embodiment comprises an acrylic polymer as a binder, and a wax;
The precoating agent according to the second embodiment comprises an oil modified alkyd resin as a binder, and a wax;
The precoating agent according to the third embodiment includes an acrylic polymer as a binder and an oil-modified alkyd resin, and a wax.
Specifically, the effects of the present invention can be obtained even if the precoating agent of the present invention contains one of an acrylic polymer or an oil-modified alkyd resin as a binder (first embodiment or second embodiment). In addition, even if the precoating agent of the present invention contains both an acrylic polymer and an oil-modified alkyd resin as a binder (third embodiment), these binders do not adversely affect each other, and the effect of the present invention is can get. More specifically, in any of the first to third embodiments, for example, it is possible to form a precoat film which is excellent in the film removability and the retentivity to the substrate.

When the precoat agent contains such a binder in combination with the wax, the removability of the precoat film and the retentivity to the substrate are sufficiently improved. Even if a polymer containing no acrylate monomer (except oil-modified alkyd resin) or a polymer containing only an acrylate monomer is used as a binder, at least one of the removability of the precoat film and the residual property to the substrate is reduced. .

(A) Acrylic Polymer Acrylic polymer is any polymer that contains an acrylate monomer as a part of its constituent components such as monomer components and modifying components. An acrylic polymer is, in particular, a polymer comprising an acrylate monomer and another monomer other than the acrylate monomer. Acrylate monomers are included as part of components such as monomer components and modifying components of acrylic polymers. As a specific example of an acrylic polymer, it is selected from the group which consists of an acrylate monomer containing copolymer, a urethane modified acrylic resin, and an epoxy modified acrylic resin, for example.

The lower limit of the content of the acrylate monomer contained in the acrylic polymer is usually 0.1% by weight or more based on the total monomer components, and the removability of the precoat film and the remaining property to the substrate are From the viewpoint of further improvement, it is preferably 1% by weight or more, more preferably 5% by weight or more, still more preferably 8% by weight or more, and most preferably 10% by weight or more. The content of the acrylate monomer contained in the acrylic polymer is usually 99.9% by weight or less based on the total monomer component with respect to the upper limit value, and the removability of the precoat film and the remaining property to the substrate From the viewpoint of further improvement, it is preferably 90% by weight or less, more preferably 80% by weight or less, still more preferably 70% by weight or less, and most preferably 60% by weight or less. The range of the content of the acrylate monomer contained in the acrylic polymer is, for example, 0.1 to 99.9% by weight with respect to all the monomer components, and the removability of the precoat film and the remaining property to the substrate Preferably, 1 to 90 wt%, more preferably 5 to 80 wt%, still more preferably 5 to 70 wt%, particularly preferably 5 to 60 wt%, most preferably 10 to 60 wt% from the viewpoint of further improvement of It is. The total monomer component refers to all the monomer components (all the raw materials or their total amount) constituting the polymer.

(A1) Acrylate monomer-containing copolymer The acrylate monomer-containing copolymer is a copolymer containing an acrylate monomer as a monomer component, that is, a copolymer of an acrylate monomer and another radically polymerizable monomer. In the present specification, (meth) acrylic is meant to include acrylic and methacrylic. For example, methyl (meth) acrylates include methyl acrylate and methyl methacrylate.

The acrylate monomer may be any radically polymerizable organic compound other than (meth) acrylic acid which contains one (meth) acryloyl group in one molecule. The (meth) acryloyl group includes an acryloyl group and a methacryloyl group, and any one of these groups is contained in an acrylate monomer. (Meth) acrylic acid includes acrylic acid and / or methacrylic acid. Specific examples of acrylate monomers include, for example, the following monomers:

Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, octadecyl (meth) acrylate, Alkyl (meth) acrylates such as docosanyl (meth) acrylate;
Acid group-containing (meth) acrylates such as 2-carboxyethyl acrylate, crotonic acid, maleic acid, fumaric acid, itaconic acid;
Hydroxyl-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyalkylene glycol mono (meth) acrylate, etc.
Cycloalkyl (meth) acrylates such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate and the like;
Cycloalkyl substituted alkyl (meth) acrylates such as cyclopentyl methyl (meth) acrylate, cyclohexylmethyl (meth) acrylate, 2-cyclohexylethyl (meth) acrylate;
Aralkyl (meth) acrylates such as benzyl (meth) acrylate and 2-phenylethyl (meth) acrylate;
Glycidyl group-containing (meth) acrylates such as glycidyl (meth) acrylate, β-methyl glycidyl (meth) acrylate;
Acrylamide compounds such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, n-methylol methacrylamide;
Keto group-containing vinyl compounds such as acrolein, diacetone acrylamide, vinyl methyl ketone, diacetone acrylate, and acetonitrile acrylate.
The acrylate monomers may be used in combination with one or more monomers.

Preferred acrylate monomers are alkyl (meth) acrylates, acid group containing (meth) acrylates, hydroxyl group containing (meth) acrylates, or mixtures thereof. More preferred acrylate monomers are alkyl (meth) acrylates, hydroxyl group-containing (meth) acrylates, or mixtures thereof. Further preferred acrylate monomers are mixtures of alkyl (meth) acrylates and hydroxyl group-containing (meth) acrylates, in particular mixtures of methyl (meth) acrylate, butyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate.

Other radically polymerizable monomers contained in the acrylate monomer-containing copolymer may be acrylate monomers and any radically polymerizable monomers other than (meth) acrylic acid. Other radically polymerizable monomers include vinyl monomers and diene monomers.

The vinyl-based monomer is selected from the group consisting of, for example, vinyl ester compounds, aromatic vinyl compounds, polyfunctional vinyl compounds, vinylidene halide compounds and the like.

Specific examples of the vinyl ester compound include vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl pyrrolidone, acrylonitrile, methacrylonitrile and the like.
Specific examples of the aromatic vinyl compound include, for example, styrene, p-tert-butylstyrene, α-methylstyrene, vinyltoluene, p-methylstyrene, p-chlorostyrene, chloromethylstyrene, p-vinylbenzoic acid and the like. Be
Specific examples of polyfunctional vinyl compounds include, for example, divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, allyl methacrylate, diallyl phthalate, trimethylolpropane triacrylate, glycerin diallyl ether, polyethylene glycol dimethacrylate And polyethylene glycol diacrylate.
Examples of vinylidene halide compounds include vinyl chloride, vinylidene chloride, vinylidene fluoride and the like.

As a specific example of a diene type monomer, butadiene, an isoprene etc. are mentioned, for example.

Preferred other radically polymerizable monomers are vinyl monomers, in particular vinyl ester compounds, aromatic vinyl compounds, and mixtures thereof.

The preferred acrylate monomer-containing copolymer is a vinyl monomer-acrylate monomer copolymer. More preferred acrylate monomer-containing copolymers are vinyl ester compound-acrylate monomer copolymers, aromatic vinyl compound-acrylate monomer copolymers, or mixtures thereof. Further preferred acrylate monomer-containing copolymers are styrene-acrylate monomer copolymers and vinyl acetate-acrylate monomer copolymers.

The content of the acrylate monomer contained in the acrylate monomer-containing copolymer may be in the same range as the content of the acrylate monomer contained in the above-mentioned acrylic polymer, and the film removability of the precoat film and the substrate From the viewpoint of further improving the residual property of the polymer, it is particularly preferably 10 to 60% by weight, more preferably 20 to 60% by weight, still more preferably 30 to 60% by weight, most preferably 40 to 60%. It is weight%. The total monomer component refers to all the monomer components (all the raw materials or their total amount) constituting the copolymer.

The number average molecular weight (Mn) of the acrylate monomer-containing copolymer is usually 2,000 to 500,000, and preferably 4,000 to 300,000.

The acrylate monomer-containing copolymer can be produced by a known method.

The acrylate monomer-containing copolymer can also be obtained as a commercial product. As a commercial item of the acrylate monomer containing copolymer, for example, AP-3140, AP-3770, AP-6750, AP-691T, TI-3052 (manufactured by Showa Denko; styrene-acrylic copolymer resin), 5400EF, EC C.-740EF, NST-100EF (manufactured by DIC; styrene-acrylic copolymer resin), CF-2800 (manufactured by DIC; vinyl acetate-acrylic copolymer resin), and the like.

(A2) Urethane-Modified Acrylic Resin The urethane-modified acrylic resin is a polymer (P) having a polyacrylic resin portion as a main chain and a urethane portion introduced as a side chain of the main chain, or It is a polymer mixture (Q) of polyacrylic resin and polyurethane which can form a polymer (P). Specific examples of the polymer (P) include the following polymers (a2-1) and (a2-2). As a specific example of the polymer mixture (Q), polymer (a2-3) can be mentioned. The preferred urethane-modified acrylic resin is the polymer (a2-3).

Polymer (a2-1):
The polymer (a2-1) is a copolymer of a product obtained by subjecting a hydroxyl group-containing acrylic monomer to an addition reaction with an equimolar reaction product of a diisocyanate compound and a monoalcohol. A urethane bond is formed by the reaction of the diisocyanate compound and the monoalcohol, and a urethane bond is also formed by the reaction of the hydroxyl group-containing acrylic monomer with the reaction product.

The diisocyanate compound of the polymer (a2-1) may be any organic compound having two isocyanate groups in one molecule. Specific examples of the diisocyanate compound include, for example, aliphatic diisocyanates such as tetramethylene diisocyanate and lysine diisocyanate; and alicyclic diisocyanates such as 1,4-cyclohexylene diisocyanate, 4,4-dicyclohexylmethane diisocyanate and isophorone diisocyanate; -Tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, diphenyl diisocyanate, xylylene diisocyanate, 3,3-dimethyl-4,4-biphenyl diisocyanate, 3,3-dimethoxy- 4,4-Bifene diisocyanate, 1,5-naphthalene diisocyanate, 1,6-tetrahydronaphthalene diisocyanate, dibenzyl diisocyanate, di-diisocyanate E alkenyl ether diisocyanate, aromatic diisocyanates such as m- or p- tetramethylxylylene diisocyanate.

The monoalcohol of the polymer (a2-1) may be any organic compound having one hydroxyl group in one molecule. Specific examples of monoalcohols include aliphatic monoalcohols such as methanol, ethanol, propanol and butanol; alicyclic monoalcohols such as cyclohexanol and 2-methyl-1-cyclohexanol; phenol, m-cresol, o- Aromatic monoalcohols such as ethylphenol and the like can be mentioned.

The hydroxyl group-containing acrylic monomer of the polymer (a2-1) is any organic compound having one or more (in particular, one) hydroxyl group and one or more (in particular, one) (meth) acryloyl group in one molecule. Good. As a specific example of a hydroxyl-containing acryl monomer, the hydroxyl-containing (meth) acrylate illustrated as an acrylate monomer of an acrylate monomer containing copolymer is mentioned, for example. Preferred are 2-hydroxyethyl (meth) acrylate and polyalkylene glycol (meth) acrylate.

The polymer (a2-1) may contain another monomer as a copolymerization component of a hydroxyl group-containing acrylic monomer. As other monomers of the polymer (a2-1), for example, acrylate monomers other than the hydroxyl group-containing (meth) acrylate exemplified as the acrylate monomer of the acrylate monomer-containing copolymer (especially alkyl (meth) acrylate, acid group-containing (meth) And (iii) acrylates, cycloalkyl (meth) acrylates, cycloalkyl substituted alkyl (meth) acrylates, aralkyl (meth) acrylates and keto group-containing vinyl compounds), and other radically polymerizable monomers of acrylate monomer-containing copolymers.

The content of the acrylate monomer contained in the polymer (a2-1) may be in the same range as the content of the acrylate monomer contained in the above-mentioned acrylic polymer, and the removability of the precoat film and the substrate From the viewpoint of further improving the residual property of the polymer, it is particularly preferably 10 to 60% by weight, more preferably 20 to 60% by weight, still more preferably 30 to 60% by weight, most preferably 40 to 60%. It is weight%. Here, the acrylate monomer is an acrylate monomer of an acrylate monomer-containing copolymer. The total monomer component refers to all the monomer components (all the raw materials or their total amount) constituting the polymer. Diisocyanate compounds and monoalcohols are also included in all monomer components.

The number average molecular weight of the polymer (a2-1) is usually 2,000 to 500,000, preferably 100,000 to 300,000.

The reaction of the diisocyanate compound with a monoalcohol to obtain the polymer (a2-1), the reaction of the reaction product with a hydroxyl group-containing acrylic monomer, and the copolymerization reaction of the reaction product can be carried out by known methods. .

The polymer (a2-1) may be one produced by the above method or may be obtained as a commercial product.

Polymer (a2-2):
The polymer (a2-2) is a reactant obtained by reacting a hydroxyl group-containing acrylic polymer with a polyvalent isocyanate compound or a monoisocyanate compound. A urethane bond is formed by the reaction of the hydroxyl group-containing acrylic polymer and the polyvalent isocyanate compound or the monoisocyanate compound.

The hydroxyl group-containing acrylic polymer of the polymer (a2-2) is a homopolymer of a hydroxyl group-containing acrylic monomer or a copolymer of a hydroxyl group-containing acrylic monomer and another monomer. Examples of the hydroxyl group-containing acrylic monomer of the polymer (a2-2) include hydroxyl group-containing (meth) acrylates exemplified as the acrylate monomer of the acrylate monomer-containing copolymer. As other monomers of the polymer (a2-2), for example, acrylate monomers other than the hydroxyl group-containing (meth) acrylate exemplified as the acrylate monomer of the acrylate monomer-containing copolymer (especially alkyl (meth) acrylate, acid group-containing (meth) And (iii) acrylates, cycloalkyl (meth) acrylates, cycloalkyl substituted alkyl (meth) acrylates, aralkyl (meth) acrylates and keto group-containing vinyl compounds), and other radically polymerizable monomers of acrylate monomer-containing copolymers.

The polyvalent isocyanate compound of the polymer (a2-2) may be any organic compound having two or more isocyanate groups in one molecule. Examples of the polyvalent isocyanate compound include diisocyanate compounds exemplified as the diisocyanate compound of the polymer (a2-1); and triisocyanate compounds such as triphenylmethane-4,4 ', 4'-triisocyanate.

The monoisocyanate compound of the polymer (a2-2) may be any organic compound having one isocyanate group in one molecule. Examples of the monoisocyanate compound include aliphatic monoisocyanates such as butyl isocyanate and hexyl isocyanate; alicyclic monoisocyanates such as cyclohexyl isocyanate; and aromatic monoisocyanates such as phenyl isocyanate.

The content of the acrylate monomer contained in the polymer (a2-2) may be in the same range as the content of the acrylate monomer contained in the above-mentioned acrylic polymer, and the film removability of the precoat film and the substrate From the viewpoint of further improving the residual property of the polymer, it is particularly preferably 10 to 60% by weight, more preferably 20 to 60% by weight, still more preferably 30 to 60% by weight, most preferably 40 to 60%. It is weight%. Here, the acrylate monomer is an acrylate monomer of an acrylate monomer-containing copolymer. The total monomer component refers to all the monomer components (all the raw materials or their total amount) constituting the polymer. Polyvalent isocyanate compounds and monoisocyanate compounds are also included in all the monomer components.

The number average molecular weight of the polymer (a2-2) is usually 2,000 to 500,000, preferably 5,000 to 40,000, more preferably 100,000 to 300,000.

The polymerization of a hydroxyl group-containing acrylic monomer to obtain a polymer (a2-2), the polymerization of a hydroxyl group-containing acrylic monomer and another monomer, and the reaction of a hydroxyl group-containing acrylic polymer with a polyisocyanate compound or a monoisocyanate compound are known methods. Can be done by

The polymer (a2-2) may be one produced by the above method or may be obtained as a commercial product.

Polymer (a2-3):
The polymer (a2-3) is a mixture of a terminal hydrazine structure-containing aqueous polyurethane (R) and a polyacrylic resin (S) having a carbonyl group. At the time of film formation, the hydrazino group of the terminal hydrazine structure-containing aqueous polyurethane (R) and the carbonyl group of the polyacrylic resin (S) undergo a dehydration reaction to form a crosslinked structure.

The terminal hydrazine structure-containing aqueous polyurethane (R) is obtained by reacting a diisocyanate (r1) and a diol (r2) to obtain a polyurethane prepolymer (r), and then using the basic substance of the obtained polyurethane prepolymer (r). It is preferable that it is a water-based polyurethane obtained by performing mixing of the sum, chain extension by a hydrazine type compound, and water.

The diisocyanate (r1) may be any organic compound having two isocyanate groups in one molecule. Examples of the diisocyanate (r1) include diisocyanate compounds exemplified as the diisocyanate compound of the polymer (a2-1).

The diol (r2) contains a polycarbonate diol (r21), a carboxyl group-containing diol (r22) or a mixture thereof.

As polycarbonate diol (r21), for example, diol such as 1,4-butanediol, 1,6-hexanediol, diethylene glycol and the like, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate And compounds obtained by the reaction with phosgene. The weight average molecular weight of the polycarbonate diol (r21) is usually 500 to 5,000, especially 800 to 2,500. Among the polycarbonate diols (r21), compounds obtained by the reaction of a diol and methyl carbonate and / or ethyl carbonate are preferable from the viewpoint of further improving the removability of the precoat film and the remaining property to the substrate.

The amount of the polycarbonate diol (r21) used is preferably 70 to 99% by weight, more preferably 80 to 97% by weight, of the polycarbonate diol (r21) in the diol (r2).

The carboxyl group-containing diol (r22) is not particularly limited, and any of various carboxyl group-containing diols can be used. Among them, 2,2-dimethylol propionic acid, 2,2-dimethylol butyric acid, 2,2 Preferred are dimethylol monocarboxylic acids such as dimethylol valeric acid. These carboxyl group-containing diols (r22) may be reacted directly with diisocyanates in combination with polycarbonate diols (r21), and further subjected to reactions with diisocyanates in combination with other diols (r23). It is also good. The content of the carboxyl group-containing diol (r22) in the diol (r2) is preferably such that the acid value of the polyurethane prepolymer (r) is 10 to 40 mg KOH / g, and is 15 to 30 mg KOH / g. It is more preferable that it is a range. As another diol (r23), low molecular weight glycols, polyether glycols, polyester glycols etc. are mentioned, for example. These may be used alone or in combination of polyether glycols and / or polyester glycols with low molecular weight glycols.

As a reaction for producing a polyurethane prepolymer (r) from the above-mentioned components, an organic solvent such as dioxane, acetone, methyl ethyl ketone, N-methyl pyrrolidone, tetrahydrofuran etc. which is inert to isocyanate groups and has a large affinity to water In particular, it is desirable to carry out at a temperature of 20 to 120 ° C., preferably 30 to 100 ° C.

The urethane prepolymer (r) thus obtained is then subjected to neutralization with a basic substance, chain elongation with a hydrazine compound and mixing with water to obtain a terminal hydrazine structure-containing aqueous polyurethane (R) and can do. There is no particular limitation on the order of neutralization of the urethane prepolymer (r) with the basic substance, and chain extension by the hydrazine compound and mixing with water. For example, the following method is preferred. (Method 1) A method in which the urethane prepolymer (r) is neutralized with a basic substance, mixed with water, and then chain extension with a hydrazine compound. (Method 2) A method in which neutralization of a urethane prepolymer (r) with a basic substance and mixing with water are simultaneously performed, and then chain elongation is performed by a hydrazine compound. (Method 3) A method in which neutralization of the urethane prepolymer (r) with a basic substance, chain elongation with a hydrazine compound and mixing with water are simultaneously performed.

Examples of the basic substance used as a neutralizing agent include trimethylamine, triethylamine, tri-n-propylamine, tributylamine, potassium hydroxide, ammonia and the like. These can be used as an aqueous solution as needed as mentioned above.

The hydrazine compound used as a chain extender is not particularly limited, and examples thereof include hydrazine, ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine and butylene-1,4-dihydrazine. Etc. These can be used as an aqueous solution as needed as mentioned above.

As a chain extender, not only a hydrazine compound but also other chain extenders generally used as a chain extender for urethane prepolymer can be used in combination. Examples of such other chain extenders include, but are not limited to, for example, polyols such as ethylene glycol and propylene glycol; ethylene diamine, propylene diamine, hexamethylene diamine, tolylene diamine, xylylene diamine, diphenyl diamine, diamino cyclohexyl Mention may be made of aliphatic diamines such as methane, piperazine, 2-methylpiperazine, isophorone diamine, alicyclic diamines and aromatic diamines. When chain extension of the urethane prepolymer (r) is carried out by using such other chain extenders, it is necessary that the chemical molecule end of the polymer molecule be maintained at the chemical structure of -NHNH ₂ . By retaining this chemical structure, it can be functionally linked to the carbonyl group in the polyacrylic resin (S).

The polyacrylic resin (S) may be a polymer obtained from vinyl monomers (s) containing the acrylate monomer of the acrylate monomer-containing copolymer. Preferred polyacrylic resin (S) is a homopolymer of a carbonyl group-containing vinyl-based monomer (s1), and a carbonyl group-containing vinyl-based monomer, from the viewpoint of further improving the film removability of the precoat film and the residual property to the substrate. It is a copolymer of (s1) and another vinyl monomer (s2). It is particularly preferable to be a copolymer of a carbonyl group-containing vinyl monomer (s1) and another vinyl monomer (s2) because the content of the carbonyl group can be adjusted.

As a carbonyl group containing vinyl-type monomer (s1), the keto group containing vinyl compound illustrated as an acrylate monomer of the said acrylate monomer containing copolymer is mentioned, for example.
As other vinyl monomers (s2), for example, acrylate monomers other than the keto group-containing vinyl compounds exemplified as the acrylate monomers of the acrylate monomer-containing copolymer (especially alkyl (meth) acrylates, acid group-containing (meth) acrylates) Hydroxyl group-containing (meth) acrylate, cycloalkyl (meth) acrylate, cycloalkyl-substituted alkyl (meth) acrylate, aralkyl (meth) acrylate, acrylamide compound and glycidyl group-containing (meth) acrylate), and acrylate monomer-containing copolymer Other radically polymerizable monomers are mentioned.

The vinyl monomers (s) constituting the polyacrylic resin (S) may contain the following monomers in addition to the above-mentioned carbonyl group-containing vinyl monomer (s1) and the other vinyl monomers (s2). Amino group-containing monomers such as dimethylaminoethyl acrylate and diethylaminoethyl acrylate; and silane compounds such as vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane and γ-methacryloxypropyltrimethoxysilane.

The content of the carbonyl group-containing vinyl monomer (s1) in the vinyl monomer (s) is from 0.5 to 5 from the viewpoint of further improving the film removability of the precoat film and the remaining property to the substrate. The content is preferably in the range of 1.0% by weight, more preferably in the range of 1.0 to 3.0% by weight.

The method for producing the polyacrylic resin (S) is not particularly limited, but a vinyl-based monomer containing a carbonyl group-containing vinyl-based monomer (s1) in the presence of the terminal hydrazine structure-containing aqueous polyurethane (R) Preferred is the method of polymerizing class (s). According to this method, the terminal hydrazine structure-containing aqueous polyurethane (R) and the polyacrylic resin (S) can be present in the same dispersion particle. When polymerizing vinyl monomers (s) containing a carbonyl group-containing vinyl monomer (s1) in the presence of a terminal hydrazine structure-containing aqueous polyurethane (R), emulsion polymerization is performed in the presence of an emulsifier preferable.

In the case of the polymerization of a vinyl-based monomer (s) containing a carbonyl group-containing vinyl-based monomer (s1), any radical polymerization initiator used for ordinary emulsion polymerization can be used as the radical polymerization initiator.

The temperature at the time of the emulsion polymerization is not particularly limited, but may be within the range of the known emulsion polymerization, for example, the range of 30 to 90 ° C. may be mentioned. In addition, the emulsion polymerization is performed under normal pressure or under pressure when a gaseous vinyl monomer is used.

The mixture of the terminal hydrazine structure-containing aqueous polyurethane (R) and the carbonyl group-containing polyacrylic resin (S) thus obtained is an aqueous solution containing the terminal hydrazine structure-containing aqueous polyurethane (R) and the polyacrylic resin (S) It is preferable that it is a dispersed resin particle. The aqueous dispersion resin particles may have, for example, a so-called core-shell structure having a terminal hydrazine structure-containing aqueous polyurethane (R) in a shell and a polyacrylic resin (S) in a core, or containing a terminal hydrazine structure The aqueous polyurethane (R) and the polyacrylic resin (S) may be homogeneously compatibilized, or they may be compatibilized such that the abundance ratio of both polymers is different from the center to the surface of the resin particle and has a concentration gradient. It may be The aqueous dispersion resin particles may have the form of an aqueous dispersion of resin particles containing the above-described polyacrylic resin (S) and the terminal hydrazine structure-containing aqueous polyurethane (R).

The ratio of the terminal hydrazine structure-containing aqueous polyurethane (R) to the polyacrylic resin (S) is the solid content weight ratio (A / B) from the viewpoint of further improving the removability of the precoat film and the remaining property to the substrate. And preferably 10/90 to 90/10, and more preferably 20/80 to 40/60.

The content of the acrylate monomer contained in the polymer (a2-3) may be in the same range as the content of the acrylate monomer contained in the above-mentioned acrylic polymer, and the removability of the precoat film and the substrate From the viewpoint of further improving the residual property of the polymer, it is particularly preferably 10 to 60% by weight, more preferably 20 to 60% by weight, still more preferably 30 to 60% by weight, most preferably 40 to 60%. It is weight%. Here, the acrylate monomer is an acrylate monomer of an acrylate monomer-containing copolymer. The total monomer component refers to all the monomer components (all the raw materials or their total amount) constituting the polymer mixture.

The number average molecular weight of the polymer (a2-3) is usually from 1000 to 1,000,000, preferably from 10,000 to 500,000.

The polymer (a2-3) is commercially available. As a commercial item of a polymer (a2-3), CG-5010EF, HY-364 (made by DIC Corporation) etc. are mentioned, for example.

(A3) Epoxy-Modified Acrylic Resin The epoxy-modified acrylic resin may be an acrylic resin modified with an epoxy resin, or an epoxy resin modified with an acrylic resin. The epoxy-modified acrylic resin is usually a copolymer of an unsaturated bond-containing epoxy resin and a vinyl monomer containing an acrylate monomer.

The unsaturated bond-containing epoxy resin is a reaction product of an epoxy resin and a fatty acid, an epoxy resin, a reaction product of a glycidyl group-containing vinyl monomer and an amine, or a mixture thereof. Accordingly, as the epoxy-modified acrylic resin, for example, a copolymer (graft polymer) (a 3-1) of a reaction product of an epoxy resin and a fatty acid and a vinyl monomer containing an acrylate monomer, or an epoxy resin, a glycidyl group-containing vinyl A copolymer (a3-2) of a reactant of a monomer and an amine and a vinyl monomer containing an acrylate monomer can be mentioned.

Copolymer (a3-1):
The copolymer (a3-1) is obtained by graft polymerization reaction of an unsaturated bond-containing epoxy resin obtained by addition reaction of an epoxy resin (t) and a fatty acid (u) with a vinyl monomer (v) containing an acrylate monomer. It is obtained.

The epoxy resin (t) is a resin polymer having one or more, preferably two or more epoxy groups per molecule. The epoxy equivalent of the epoxy resin (t) is usually 170 to 3,000. Specific examples of the epoxy resin (t) include various epoxy resins such as bisphenol epoxy resin, alicyclic epoxy resin, phenol novolac epoxy resin, polyethylene glycol epoxy resin, and epoxidized polybutadiene. Preferably, the epoxy resin (t) comprises a bisphenol epoxy resin, a phenol novolac epoxy resin, in particular a bisphenol epoxy resin.

As a bisphenol type epoxy resin, for example, Epiclon 850, 1050, 3050, 4050, 7050 (above, DIC Corporation make), Epicoat 828, 834, 1001, 1004, 1007, 1009 (above, Shell company in the Netherlands), DER 660 661J, 662, 664J, 667J, 668, 669J (all manufactured by Dow Chemical Co., USA) and the like can be used.
As the phenol novolac epoxy resin, for example, Epiclon N-740, 775 (all manufactured by DIC Corporation) can be used.

As the alicyclic epoxy resin, for example, Uninox 201, 289 (manufactured by Union Carbide of USA) or the like can be used.
As the polyethylene glycol epoxy resin, for example, Epicoat 812 (manufactured by Shell, The Netherlands), Epolite 40E, 200E, 400E (all manufactured by Kyoeisha Chemical Co., Ltd.) can be used.
As the epoxidized polybutadiene, for example, BF-1000 (manufactured by Adeka Argus) can be used.

The epoxy resin (t) can be used as a mixture of one or more epoxy resins.

The fatty acid (u) is not particularly limited, and usually includes unsaturated fatty acids. Specific examples of fatty acid (u) include, for example, soy oil fatty acid, linseed oil fatty acid, dehydrated castor oil fatty acid, castor oil fatty acid, tall oil fatty acid, cottonseed oil fatty acid, soybean oil fatty acid, olive oil fatty acid, safflower oil fatty acid, rice bran oil fatty acid etc Oil fatty acid; non-drying oil fatty acid such as hydrogenated coconut oil fatty acid, coconut oil fatty acid, palm oil fatty acid can be exemplified. Furthermore, oleic acid, linoleic acid, linolenic acid, eleostearic acid, unsaturated fatty acids such as ricinoleic acid, saturated fatty acids such as octylic acid, uraric acid, stearic acid, etc. can also be exemplified. These may be used alone or in combination of two or more.

The vinyl monomer (v) comprises an acrylate monomer. As an acrylate monomer contained in vinyl monomer (v), the acrylate monomer of an acrylate monomer containing copolymer is mentioned, for example. As another monomer other than the acrylate monomer contained in a vinyl monomer (v), the other radically polymerizable monomer of an acrylate monomer containing copolymer is mentioned, for example.

Preferred acrylate monomers included in the vinyl monomer (v) are alkyl (meth) acrylates, hydroxyl group-containing (meth) acrylates, acid group-containing (meth) acrylates, or mixtures thereof. More preferred acrylate monomers are mixtures of alkyl (meth) acrylates, hydroxyl group-containing (meth) acrylates and acid group-containing (meth) acrylates, in particular methyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate ) A mixture of acrylate and methacrylic acid.

It is preferable to use the epoxy resin (t) and the fatty acid (u) in the range in which the equivalent ratio of the epoxy group in the epoxy resin and the carboxyl group derived from the fatty acid is an excess of the epoxy group. The remaining epoxy group can be reacted with an acid group-containing compound, preferably with a monobasic acid compound such as benzoic acid, p-tert-benzoic acid, iso-octanoic acid, isodecanoic acid, cyclohexanoic acid and the like. These components are charged into a reactor, and if necessary, each component is bonded to an epoxy resin through an ester bond under heating conditions in the presence of a known and conventional esterification catalyst to obtain an epoxy ester of fatty acid. Next, the obtained epoxy ester and vinyl monomer (v) are polymerized under heating conditions in the presence of a radical polymerization initiator, if necessary, in an organic solvent, and an epoxy ester and a vinyl monomer containing an acrylate monomer A graft polymer (copolymer (a3-1)) is obtained. The reaction conditions are not particularly limited. For example, the reaction temperature is preferably about 50 to 150.degree.

The content of the acrylate monomer contained in the copolymer (a3-1) may be in the same range as the content of the acrylate monomer contained in the above-mentioned acrylic polymer, and the film removability of the precoat film and From the viewpoint of further improving the residual property to the substrate, it is particularly preferably 10 to 60% by weight, more preferably 20 to 60% by weight, still more preferably 30 to 60% by weight, most preferably 40 to 60% by weight. It is ̃60% by weight. Here, the acrylate monomer is an acrylate monomer of an acrylate monomer-containing copolymer. The total monomer component refers to all the monomer components (all the raw materials or their total amount) constituting the copolymer.

The number average molecular weight of the copolymer (a3-1) is usually 1,000 to 100,000, preferably 5,000 to 40,000.

The copolymer (a3-1) can be obtained as a commercial product.

Copolymer (a3-2):
The copolymer (a3-2) contains an acrylate resin and an unsaturated bond-containing epoxy resin (x) obtained by reacting an epoxy resin (x1), a glycidyl group-containing vinyl monomer (x2) and an amine (x3) It is obtained by the polymerization reaction with the vinyl monomer (y). In the production of the unsaturated bond-containing epoxy resin (x), the epoxy group derived from the epoxy resin (x1) is opened by the amino group derived from the amine (x3), and at the same time the amino group is contained in the epoxy resin (x1) component. be introduced. On the other hand, the glycidyl group-containing vinyl monomer (x2) reacts with the epoxy group in the epoxy resin (x1) via the amine (x3).

Examples of the epoxy resin (x1) include the same epoxy resins as the epoxy resin (t) of the copolymer (a3-1). Preferably, the epoxy resin (x1) comprises a bisphenol epoxy resin, a phenol novolac epoxy resin, in particular a bisphenol epoxy resin.

The glycidyl group-containing vinyl monomer (x2) may be any organic compound having one or more (especially one) glycidyl group and one or more (especially one) vinyl group in one molecule. As a specific example of a glycidyl group containing vinyl monomer (x2), the glycidyl group containing (meth) acrylate illustrated as an acrylate monomer of an acrylate monomer containing copolymer, (meth) allyl glycidyl ether etc. are mentioned, for example.

The amine (x3) is not particularly limited as long as it is an amine compound capable of ring-opening an epoxy group, and, for example, alkanolamines, aliphatic amines, aromatic amines, alicyclic amines, aromatic nucleus substituted aliphatic amines And the like. These can be used by appropriately selecting one or two or more. Specifically, examples of alkanolamines include ethanolamine, diethanolamine, diisopropanolamine, di-2-hydroxybutylamine, N-methylethanolamine, N-ethylethanolamine, N-benzylethanolamine and the like. . Examples of aliphatic amines include primary amines such as ethylamine, propylamine, butylamine, hexylamine, laurylamine, stearylamine, palmitylamine, oleylamine, erucylamine and the like; and diamine such as diethylamine, dipropylamine and dibutylamine And the like. Examples of the aromatic amines include toluidines, xylidines, cumidine (isopropylaniline), hexylanilines, nonylanilines, dodecylanilines and the like. Examples of alicyclic amines include cyclopentylamines, cyclohexylamines and norbornylamines. Examples of the aromatic nucleus-substituted aliphatic amines include benzylamine, phenethylamine and the like.

The vinyl monomer (y) comprises an acrylate monomer. The acrylate monomer contained in the vinyl monomer (y) is, for example, an acrylate monomer of an acrylate monomer-containing copolymer, particularly an acrylate monomer other than glycidyl group-containing (meth) acrylate among acrylate monomers of the acrylate monomer-containing copolymer, or These mixtures are mentioned. As another monomer other than the acrylate monomer contained in a vinyl monomer (y), the other radically polymerizable monomer of an acrylate monomer containing copolymer is mentioned, for example.

Preferred acrylate monomers contained in the vinyl monomer (y) are alkyl (meth) acrylates, hydroxyl group-containing (meth) acrylates, acid group-containing (meth) acrylates, or mixtures thereof. More preferred acrylate monomers are mixtures of alkyl (meth) acrylates, hydroxyl group-containing (meth) acrylates and acid group-containing (meth) acrylates, in particular methyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate ) A mixture of acrylate and methacrylic acid.

The unsaturated bond-containing epoxy resin (x) can usually be easily produced by heating the respective components in the presence of an organic solvent. The reaction temperature is usually about 60 to 200 ° C. The reaction time depends on the reaction temperature, but under the above temperature conditions, it is preferably about 3 to 10 hours.

The polymerization of the unsaturated bond-containing epoxy resin (x) and the vinyl monomer (y) containing an acrylate monomer can be carried out by a known method. For example, it is preferable to use a solution polymerization method. For example, it can be polymerized at a reaction temperature of about 60 to 150 ° C. in the presence of a polymerization initiator.

The content of the acrylate monomer contained in the copolymer (a3-2) may be in the same range as the content of the acrylate monomer contained in the above-mentioned acrylic polymer, and the film removability of the precoat film and From the viewpoint of further improving the residual property to the substrate, it is particularly preferably 10 to 60% by weight, more preferably 20 to 60% by weight, still more preferably 30 to 60% by weight, most preferably 40 to 60% by weight. It is ̃60% by weight. Here, the acrylate monomer is an acrylate monomer of an acrylate monomer-containing copolymer. The total monomer component refers to all the monomer components (all the raw materials or their total amount) constituting the copolymer.

The number average molecular weight of the copolymer (a3-2) is usually 2,000 to 50,000, preferably 3,000 to 6,000.

The copolymer (a3-2) can be obtained as a commercial product. Examples of commercial products of the copolymer (a3-2) include Modepics 301, Modepics 302, Modepix 304 (all manufactured by Arakawa Chemical Industries, Ltd.), and the like.

(B) Oil-Modified Alkyd Resin The oil-modified alkyd resin is a reactant obtained by reacting a drying oil fatty acid with a hydroxyl group-containing polyester containing a fatty acid and a polyhydric alcohol as a monomer component (esterification reaction).

The fatty acid constituting the hydroxyl group-containing polyester may be phthalic acid, benzenephthalic acid such as isophthalic acid or terephthalic acid, adipic acid or a mixture thereof. Preferred benzene dicarboxylic acids include phthalic acid.
Examples of polyhydric alcohols include glycerol, pentaerythritol and mixtures thereof. Preferred polyhydric alcohols include glycerol.

When the polyhydric alcohol is glycerol, in the hydroxyl group-containing polyester, hydroxyl groups bonded to carbon atoms at both ends of the three carbon atoms of glycerol are reacted with a fatty acid (for example, benzenedicarboxylic acid) (esterification reaction) Provided, the hydroxyl group bonded to the central carbon atom of glycerol remains. In oil-modified alkyd resins, such hydroxyl groups form ester bonds by reaction with drying oil fatty acids.

Dry oil fatty acid means fatty acid contained in dry oil. The drying oil is an oil that solidifies in air, and may have an iodine value of 130 or more. Specific examples of the drying oil include, for example, linseed oil, soy sauce, coconut oil, shiso oil, walnut oil, soy sauce, safflower oil, sunflower oil, sunflower oil, and mixtures thereof. Examples of drying oil fatty acids include oleic acid, linoleic acid and linolenic acid.

The number average molecular weight of the oil-modified alkyd resin is usually 2000 to 50000, preferably 3000 to 20000.

The condensation of fatty acids (e.g. benzenedicarboxylic acid) and polyhydric alcohols (e.g. glycerol) to obtain oil modified alkyd resins and reaction with drying oil fatty acids can be carried out by known methods.

Oil modified alkyd resins are commercially available. Examples of commercially available products of oil-modified alkyd resins include CD-520P (manufactured by DIC Corporation).

The binder is preferably selected from the group consisting of an acrylate monomer-containing copolymer, a urethane-modified acrylic resin, an epoxy-modified acrylic resin and an oil-modified alkyd resin, and more preferably a vinyl-based monomer Acrylate monomer copolymer, urethane-modified acrylic resin, epoxy-modified acrylic resin and oil-modified alkyd resin, more preferably vinyl ester compound-acrylate monomer copolymer, aromatic vinyl compound-acrylate monomer copolymer It is selected from the group consisting of urethane modified acrylic resin, epoxy modified acrylic resin and oil modified alkyd resin.

The binder used in the present invention may be used in the form of a solid consisting only of the binder, may be used in the form of an emulsion dispersed in a solvent, or in the form of a solution dissolved in a solvent It may be used. The solvent of the binder emulsion and solution may be water or an organic solvent. The preferred solvent is water.
The binder is preferably used in the form of an aqueous emulsion dispersed in water.

The binder used in the present invention is excellent in the affinity to the paint before curing, the film removability after curing, and the adhesion to the substrate.

Specifically, the binder exhibits a water contact angle of 40 ° or more, preferably 40 to 120 ° and a hexadecane contact angle of 5 ° or more, preferably 6 to 60 °, more preferably 6 to 20 °. The water contact angle is the contact angle of water to the binder film, and the value measured by the method described later is used. The hexadecane contact angle is the contact angle of hexadecane with respect to the binder film, and the value measured by the method described later is used.

The binder is preferably in the form of an adhesive of preferably 80/100 to 100/100, more preferably 90/100 to 100/100, still more preferably 95/100 to 100/100, according to the cross-cut method based on JIS K5600-5-6. Demonstrate a force. The adhesion is the adhesion of the binder film, and is indicated by the number of squares remaining after peeling off in the cross-cut method.

When at least one physical property value of the water contact angle, the hexadecane contact angle or the adhesion of the binder is too small, at least one of the removability of the precoat film and the retentivity to the substrate decreases.

The content of the binder in the precoating agent is usually 20 to 600 parts by weight with respect to 100 parts by weight of the below-mentioned wax (solid content), and is preferably from the viewpoint of further improving the removability and retentivity of the precoat film. Is preferably 20 to 450 parts by weight, more preferably 50 to 450 parts by weight, still more preferably 50 to 300 parts by weight, particularly preferably 80 to 300 parts by weight, and most preferably 80 to 240 parts by weight. A binder may be contained in combination of 2 or more types, and in that case, the total amount of them should just be in the said range.

<Wax>
As the wax, any wax used in the field of precoating agents can be used. Specific examples of the wax include plant waxes such as candelilla wax, carnauba wax, rice wax, wax wax, jojoba oil and the like; animal waxes such as beeswax, lanolin and spermaceti wax; montan wax, ozokerite, ceresin and the like Mineral wax; petroleum wax such as paraffin wax, micro wax, petrolatum; modified wax such as montan wax derivative, paraffin wax derivative, micro wax derivative; hydrogenated wax such as hardened castor oil, and derivatives thereof; 12-hydroxystearic acid Synthetic waxes other than the above, such as a system, a stearic acid amide system, a phthalic anhydride imide system, etc. are mentioned. From the viewpoint of the coatability of the precoat solution and the ease of formation of the precoat film, preferred waxes are petroleum waxes, in particular paraffin waxes. Paraffin wax is a mixture of aliphatic saturated hydrocarbons, in particular a mixture of aliphatic saturated hydrocarbons having 20 or more carbon atoms. The melting point of the wax is preferably 30 to 150 ° C., more preferably 40 to 110 ° C., still more preferably 40 to 70 ° C., from the viewpoint of the coatability of the precoat solution and the ease of formation of the precoat film.

The wax may be used in the form of an emulsion dispersed in a solvent, or may be used in the form of a solution dissolved in a solvent. The solvent of the wax emulsion and solution may be water or an organic solvent. The preferred solvent is water. The wax is preferably used in the form of an aqueous emulsion dispersed in water. The emulsification of the wax can use conventional techniques. Surfactants may be used for aqueous emulsions of waxes. The type of surfactant used in the aqueous emulsion of wax is not particularly limited, and, for example, surfactants described below (particularly polyoxyethylene alkenyl ether) can be used.

<Other ingredients>
The precoat agent of the present invention may further contain one or more additives selected from the group consisting of surfactants, thickeners, preservatives and rust inhibitors. Coating of a precoat film by the precoat agent of the present invention further comprising, in particular, one or more additives preferably selected from the group consisting of surfactants and thickeners, preferably both surfactants and thickeners. The removability and the survivability to the substrate are further improved.

The surfactant may be any of anionic, nonionic and cationic surfactants, but it is possible to further improve the stability of the precoat solution, the removability of the precoat film, and the remaining property to the substrate. From the viewpoint, at least one surfactant selected from the group consisting of anionic surfactants and nonionic surfactants is preferably used. From the same viewpoint, the surfactant is more preferably a nonionic surfactant.

Examples of anionic surfactants include fatty acid salts, alkyl sulfonates, alkyl sulfates and the like.

Examples of nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyalkylene alkyl phenyl ethers, glycerin fatty acid esters, sorbitan fatty acid esters, and mixtures thereof.

The polyoxyalkylene alkyl ether is an alkyl ether of a polyalkylene glycol and may be a monoalkyl ether, a dialkyl ether, or a mixture thereof. Preferably, it is a dialkyl ether of polyoxyalkylene. The alkylene group is a linear or branched aliphatic saturated divalent hydrocarbon group having 1 to 3 carbon atoms, preferably 2 to 3 carbon atoms. The alkylene group may be, for example, a methylene group, an ethylene group, a 1,2-propylene group, or a trimethylene group. The repeating number of oxyalkylene units in the polyoxyalkylene part of the polyoxyalkylene alkyl ether is usually 2 to 30, preferably 5 to 20. The alkyl group is a linear or branched aliphatic saturated monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. The alkyl group is, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group And decyl, undecyl, lauryl, tridecyl, myristyl, pentadecyl, cetyl, heptadecyl, stearyl, nonadecyl, eicosyl and the like. The two alkyl groups of the dialkyl ether may be each independently selected, for example, different groups or the same groups. Preferably they are the same group.

Specific examples of the polyoxyalkylene alkyl ether include, for example, polyoxyethylene monomethyl ether, polyoxyethylene dimethyl ether, polyoxyethylene monoethyl ether, polyoxyethylene diethyl ether, polyoxypropylene monomethyl ether, polyoxypropylene dimethyl ether, polyoxypropylene Monoethyl ether, polyoxypropylene diethyl ether, polyoxyethylene monolauryl ether, polyoxyethylene monocetyl ether, polyoxyethylene monostearyl ether, polyoxyethylene monomyristyl ether, polyoxyethylene octyldodecyl ether, etc. may be mentioned.

The polyoxyalkylene alkenyl ether refers to an alkenyl ether of a polyalkylene glycol, which may be a mono alkenyl ether, a di alkenyl ether, a mono alkyl mono alkenyl ether, or a mixture thereof. Preferred is a monoalkenyl ether of polyoxyalkylene. The alkylene group is a linear or branched aliphatic saturated divalent hydrocarbon group having 1 to 3 carbon atoms, preferably 2 to 3 carbon atoms. The alkylene group may be, for example, a methylene group, an ethylene group, a 1,2-propylene group, or a trimethylene group. The repeating number of oxyalkylene units in the polyoxyalkylene moiety of the polyoxyalkylene alkenyl ether is usually 2 to 30, preferably 5 to 20. The alkenyl group is a linear or branched aliphatic unsaturated monovalent hydrocarbon group having 2 to 20, preferably 10 to 20 carbon atoms. The alkenyl group may be, for example, an oleyl group and the like. The two alkenyl groups of the dialkenyl ether may be each independently selected, for example, different groups or the same groups. The alkyl group of the monoalkyl monoalkenyl ether may be selected from the alkyl groups exemplified as the alkyl group of the polyoxyalkylene alkyl ether.

As a specific example of polyoxyalkylene alkenyl ether, polyoxyethylene monooleyl ether, polyoxyethylene dioleyl ether etc. are mentioned, for example.

The polyoxyalkylene alkylphenyl ether is an alkylphenyl ether of polyalkylene glycol, and may be a mono (alkylphenyl) ether having an alkylphenyl ether structure at one end, or a di (alkyl phenyl ether) having an alkylphenyl ether structure at both ends. It may be (alkylphenyl) ether, or a mixture thereof. Preferred is di (alkylphenyl) ether of polyoxyalkylene. The alkylene group is the same as the alkylene group of the polyoxyalkylene alkyl ether, and is a linear or branched aliphatic saturated divalent hydrocarbon group having 1 to 3 carbon atoms, preferably 2 to 3 carbon atoms. The repeating number of oxyalkylene units in the polyoxyalkylene part of the polyoxyalkylene alkyl phenyl ether is usually 2 to 30, preferably 5 to 20. The alkyl group is the same as the alkyl group of the polyoxyalkylene alkyl ether, and is a linear or branched aliphatic saturated monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. In the alkylphenyl group, the number of alkyl groups substituted by one phenyl group is not particularly limited, and may be, for example, 1 to 5, particularly 1 to 3. When the polyoxyalkylene alkyl phenyl ether has a plurality of alkyl groups, the plurality of alkyl groups may be independently selected.

Specific examples of the polyoxyalkylene alkyl phenyl ether include, for example, polyoxyethylene mono (methyl phenyl) ether, polyoxyethylene di (methyl phenyl) ether, polyoxyethylene mono (ethyl phenyl) ether, polyoxyethylene di (ethyl phenyl) D) Ether, polyoxypropylene mono (methylphenyl) ether, polyoxypropylene di (methylphenyl) ether, polyoxypropylene mono (ethylphenyl) ether, polyoxypropylene di (ethylphenyl) ether and the like.

Preferred nonionic surfactants are polyoxyalkylene alkyl ethers (in particular polyoxyalkylene dialkyl ethers) and / or polyoxyalkylene alkenyl ethers.

Examples of cationic surfactants include amine salts and quaternary ammonium salts.

The HLB value of the surfactant is not particularly limited, and is usually 7 to 16, particularly 8 to 15.

The precoat agent of the present invention preferably contains a polyoxyalkylene alkenyl ether as a surfactant from the viewpoint of further improving the removability of the precoat film and the remaining property to the substrate, and the polyoxyalkylene alkyl ether and More preferably, it contains a polyoxyalkylene alkenyl ether.

The content of the surfactant is preferably 0.01 to 60 parts by weight with respect to 100 parts by weight of the wax (solid content) from the viewpoint of further improving the removability of the precoat film and the remaining property to the substrate. More preferably, it is 0.1 to 50 parts by weight, still more preferably 1 to 40 parts by weight. When two or more surfactants are used, the total amount of them may be in the above range. When the precoat agent of the present invention contains a polyoxyalkylene alkyl ether and a polyoxyalkylene alkenyl ether as a surfactant, the polyoxyalkylene alkyl from the viewpoint of further improving the film removability of the precoat film and the residual property to the substrate. The content of ether is 1 to 20 parts by weight (especially 2 to 12 parts by weight) with respect to 100 parts by weight of wax (solid content), and the content of polyoxyalkylene alkenyl ether is 100 parts by weight of wax (solid content) Preferably 10 to 40 parts by weight (especially 15 to 35 parts by weight). When the wax is used in the form of an emulsion containing a surfactant, the content of the surfactant also containing the surfactant contained in the emulsion may be in the above range.

As the thickener, any of inorganic and organic thickeners can be used. As a specific example of a thickener, bentonite (sodium type bentonite, calcium type bentonite), methylcellulose, polyacrylic acid (sodium type) copolymer etc. are mentioned, for example. The thickener is preferably a polyacrylic acid copolymer (sodium salt) from the viewpoint of further improving the stability of the precoat solution, the removability of the precoat film, and the remaining property to the substrate.

The polyacrylic acid-based copolymer is a copolymer containing (meth) acrylic acid as a monomer component, and specifically, from the group consisting of (meth) acrylic acid, the above-mentioned acrylate monomer and other radically polymerizable monomers. It is a copolymer with one or more selected monomers.

The number average molecular weight of the polyacrylic acid copolymer (sodium salt) is usually 2,000 to 300,000, preferably 5,000 to 200,000.

The content of the thickener is preferably 0.01 to 50 parts by weight with respect to 100 parts by weight of the wax (solid content) from the viewpoint of further improving the removability of the precoat film and the remaining property to the substrate. More preferably, it is 0.1 to 20 parts by weight, further preferably 1 to 10 parts by weight. When two or more thickeners are used, the total amount of them may be in the above range.

As the preservative, any preservative can be used. As a specific example of antiseptic | preservative, an organic nitrogen sulfur type compound etc. are mentioned, for example. An organic nitrogen sulfur type compound is an organic compound containing a nitrogen atom and a sulfur atom, and includes, for example, an isothiazoline type compound and a benzothiazole type compound.

The content of the preservative is usually 0.01 to 50 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight of the wax (solid content). When two or more preservatives are used, the total amount thereof may be in the above range.

As the rust inhibitor, any rust inhibitor can be used. Specific examples of the rust inhibitor include, for example, alkylamines, alkanolamines, imidazole compounds, and triazole compounds. Preferably it is an alkanolamine.

The alkanolamine is an amine compound having 1 to 20 carbon atoms, preferably 2 to 10 carbon atoms, having one to three, preferably one hydroxyl group in one molecule. The number of carbon atoms is the total number of carbon atoms contained in one alkanolamine molecule. Specific examples of alkanolamines include monoethanolamine, monoisopropanolamine, monoisobutanolamine, diethanolamine, diisopropanolamine, triethanolamine, triisopropanolamine and the like.

The content of the rust inhibitor is usually 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight of the wax (solid content). When two or more rust inhibitors are used, the total amount of them may be in the above range.

The precoating agent of the present invention contains substantially no special metal oxide such as zirconium oxide. The fact that the precoating agent does not substantially contain a metal oxide means that the precoating agent does not contain a metal oxide as a raw material, but may contain it as an impurity. For example, the total content of all metal oxides in the precoating agent of the present invention is 1% by weight or less, in particular 0.1% by weight or less, based on the total amount.

[Precoat solution]
The present invention also provides a precoat solution. The precoat solution can be obtained by dissolving or dispersing a precoat agent containing a binder, a wax and a desired additive in a solvent. In particular, the binder, wax and thickener are preferably dispersed in the precoating solution. The surfactant, the preservative and the rust inhibitor are preferably dissolved in the precoating solution. The solvent may be water or an organic solvent. The preferred solvent is water. The order of addition for dissolution or dispersion is not particularly limited, and usually, all the components are simultaneously added to the mixer and mixed.

For example, if the binder and wax are each used in the form of an aqueous emulsion dispersed in water, the precoat liquid can be easily obtained by simply mixing the binder emulsion, the wax emulsion and water. In this case, the other ingredients (additives) may be added simultaneously with the binder emulsion, the wax emulsion and the water, or may be added after the binder emulsion, the wax emulsion and the water are sufficiently mixed.

The amount of the solvent (particularly water) added is such that the content of the solvent (particularly water) in the precoat solution is usually 70 to 97% by weight, preferably 75 to 95% by weight, based on the whole. is there. The amount of solvent added is the amount of solvent added during the preparation of the precoat solution. The content of the solvent in the precoating liquid is the amount of the solvent contained in the precoating liquid, and is, for example, the total amount of the solvent added at the time of preparation of the precoating liquid and the solvent contained in the emulsion. It is.

The content of the precoating agent in the precoating liquid is a value obtained by reducing the content of the solvent in the above precoating liquid from 100% by weight, and is the total amount of solids including the binder, wax and other additives. .

The total content of all metal oxides in the precoat solution of the present invention is 1% by weight or less, particularly 0.1% by weight or less, based on the total amount.

[Peeling method of coating film]
The present invention also provides a method of peeling a coating. The peeling method of the coating film of the present invention forms a precoat film by applying a precoat solution to an article which does not require coating and drying it in advance. An article which does not require coating with paint is an article for which it is desired to avoid the contamination with paint, for example, the wall of a coating line or a painting booth, a floor (grating etc.), a painting table etc. Materials). By previously forming a precoat film on such an article, even if an unnecessary coating film is formed on the precoat film, it can be easily peeled off and removed. In addition, the precoat film is excellent in the remaining property to the substrate, and can be used multiple times by one coating. The precoat film is more preferably recoated each time after removing the unnecessary coating.

The surface of the article, that is, the application surface of the precoat liquid in the article may be composed of any material, for example, may be composed of an inorganic material and / or an organic material. The inorganic material is selected from the group consisting of, for example, metals such as steel, stainless steel, copper, zinc, brass, aluminum, aluminum alloys and aluminum die-casts; and glasses such as Pyrex glass and soda glass. The organic material is, for example, polyalkyl (meth) acrylate (for example, polymethyl acrylate, polymethyl methacrylate), polycarbonate, polyethylene, polypropylene, polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, urethane rubber, fiber reinforced plastic, styrene It is selected from the group consisting of polymers such as butadiene rubber, nitrile rubber and the like. The article is preferably a resin molding made of the above-mentioned polymer. From the viewpoint of further improving the residual property of the precoat film, the coated surface of the article is preferably made of metal or polymer, particularly metal.

The pre-coating is to apply and dry the pre-coating solution to form a film prior to the contamination by the unnecessary coating. A film formed by precoating is called a precoat film. The thickness of the precoat film is not particularly limited as long as the precoat film has removability of the coating film and persistence to a substrate, and is usually 1 to 50 μm, preferably 2 to 30 μm.

It does not specifically limit as a coating method of a pre-coating liquid, For example, a brush coating method, a spray coating method, a dip coating method, a pouring flow coating method etc. are mentioned.

The method for drying the precoat solution is not particularly limited as long as the solvent in the applied precoat solution evaporates, and the method may be usually left to dry at room temperature (for example, 20 ° C.). The drying time in such a room temperature standing method is usually 1 to 48 hours. The present invention does not prevent the adoption of the method of heating and holding at 30 to 60 ° C. as the drying method.

In the present invention, the peeling of the unnecessary coating can be achieved by, for example, a physical cleaning method. In the present invention, the physical cleaning method does not need to apply the ultra-high pressure (for example, about 1000 to 3000 kgf / cm ² ) water washing step as in the conventional physical cleaning method, for example 1 to 1000 kgf / cm ² , especially 1 kgf / cm ² or more, less than 1000 kgf / cm ^2, preferably 1 ~ 500 kgf / cm ^2, more preferably 1 ~ 300 kgf / cm ^2, more preferably may be applied to 50 ~ 200 kgf / cm ² low-pressure water washing step. The unnecessary coating is easily peeled off and removed only by applying such low pressure water to the unnecessary coating on the precoat film. Furthermore, the noise from the extra-high pressure water facility and the significant reduction of the installation cost can be achieved.

Experimental Example 1
[Examples A1 to A6 and Comparative Examples A1 to A4]
(Preparation of precoat solution for coating film peeling)
The wax emulsion was prepared by emulsifying using paraffin wax (melting point 60-65 ° C.) and surfactant (polyoxyethylene oleyl ether). The wax emulsion, the following binder emulsion and water are simultaneously treated in such a ratio that the solid proportions of the wax and the binder become the values described in Table 1 and the amount of water becomes the values described in Table 1 to the whole. The mixture was mixed to prepare a precoat solution.

binder:
-Styrene-acrylic copolymer resin A (manufactured by Showa Denko; AP-3140, styrene-acrylic acid ester emulsion, solid content ratio 41% by weight, acrylate monomer content about 50% by weight, Mn = 10,000 or more)
Styrene-acrylic copolymer resin B (manufactured by DIC; 5400 EF, styrene-acrylic acid ester emulsion, solid content ratio 55% by weight, acrylate monomer content about 50% by weight, Mn = 10000 or more)
Urethane-modified acrylic resin (manufactured by DIC; HY-364, urethane-modified acrylic emulsion, solid content ratio 45% by weight, acrylate monomer content about 50% by weight, Mn ≦ 100,000)
Epoxy-modified acrylic resin A (manufactured by Arakawa Chemical Industries, Ltd .; Modepix 301, acrylic-modified epoxy ester emulsion, solid content ratio 33% by weight, acrylate monomer content about 50% by weight, Mn = 4000 to 5000)
・ Vinyl acetate-acrylic copolymer resin (manufactured by DIC; CF-2800, vinyl acetate-acrylic emulsion, solid content ratio 50% by weight, acrylate monomer content about 15% by weight, Mn = 10,000 or more)
Oil-modified alkyd resin (manufactured by DIC; CD-520P, oil-modified alkyd emulsion, solid content ratio 39% by weight, Mn = 3000)
· Acrylic copolymer resin A (manufactured by DIC; 40-418EF, acrylic emulsion, solid content ratio 55% by weight) (copolymer consisting only of acrylate monomer)
· Polyurethane resin (manufactured by Arakawa Chemical Industries, Ltd .; W 321, urethane emulsion, solid content ratio 35% by weight, acrylate monomer content 0% by weight, Mn = about 4000)

(Water contact angle)
The surface of a cold-rolled steel plate (SPCC-SD; 0.8 mm × 25 mm × 110 mm) was degreased. The binder emulsion was applied to the surface of the steel sheet by pouring, and dried overnight at 25 ° C. to form a binder film having a thickness of 30 μm. The contact angle after 2 seconds of water dropping on the surface of the binder coating was measured at 25 ° C. using a contact angle measuring machine. The measurement was performed six times, and the average value of those measured values was calculated.

(Hexadecane contact angle)
The hexadecane contact angle was measured by the same method as the water contact angle measurement method except that hexadecane was used instead of water.

(Adhesiveness)
The surface of a cold-rolled steel plate (SPCC-SD; 0.8 × 70 × 150 mm) was degreased. The binder emulsion was applied to the surface of the steel plate and dried overnight at room temperature (25 ° C.) to form a binder film having a thickness of 5 μm. The adhesion of the binder film was evaluated by the crosscut method based on JIS K5600-5-6. The measurement was performed six times, and the average value of those measured values was calculated.

(Removability of precoat film)
The surface of a cold-rolled steel plate (SPCC-SD; 0.8 mm × 25 mm × 110 mm) was degreased. The surface of this steel sheet was applied by pouring a precoating solution, and dried overnight at room temperature (25 ° C.) to form a 5 μm thick precoating film. An aqueous white paint (manufactured by Kansai Paint Co., Ltd.) for automobile is applied on the surface of the precoat film, dried for 4 days at room temperature (25 ° C) and then dried for 3 hours in a hot air drier (40 ° C). A 30 μm coating was formed. Water (25 ° C.) was applied to the coating (30 seconds) using a pressure water washer. The water pressure was about 90 kgf / cm ² . The coating film removability after application of water was visually observed.
:: The entire coating was completely removed (excellent);
○: Almost all of the coating film was removed (good);
Δ: Only a part of the coating film remained, but there was no problem in practical use (good);
X: A part of the coating film remained, and there was a problem in practical use (impossible).

(Remaining property of precoat film)
The surface of a cold-rolled steel plate (SPCC-SD; 0.8 mm × 25 mm × 110 mm) was degreased. The surface of this steel sheet was applied by pouring a precoating solution, and dried overnight at room temperature (25 ° C.) to form a 5 μm thick precoating film. Water (20 ° C.) was applied (30 seconds) to the precoat coating using a pressure water washer. The water pressure was about 90 kgf / cm ² . The persistence of the precoat film after applying water was visually observed.
:: All of the precoat film completely remained (no peeling) (excellent);
○: Almost all of the precoat film remained (no peeling) (good);
Δ: A part of the precoat film was peeled off, but there was no problem in practical use (good);
X: Most of the precoat film was peeled off, and there was a problem in practical use (not acceptable).

In Table 1, paraffin wax, binder represents the weight of the active ingredient. In the case of only the above-mentioned wax emulsion of Comparative Example A3, the precoat solution did not repel on the substrate to form a uniform precoat film. For this reason, evaluations such as contact angle and adhesion were not performed.

<Experimental Example 2>
[Examples B1 to B9, Examples C1 to C19, and Comparative Example B1]
(Preparation of precoat solution for coating film peeling)
The wax composition prepared in Experimental Example 1, the binder emulsion and water described above, and the following surfactants, thickeners, preservatives and / or rust inhibitors, the solid content ratio of each component is shown in Table 2 to Table 2 At the same time, the precoat solution was prepared by mixing simultaneously in such a ratio that the values described in 5 and the amount of water with respect to the whole would be the values described in Tables 2 to 5. Surfactants, preservatives and / or rust inhibitors were dissolved in the precoating solution. The thickener was dispersed in the precoat solution. In addition, surfactant W is used in the production of the wax emulsion, and in addition to surfactant W, surfactants A to D are further contained in the precoat liquid shown in Tables 2 to 5. There is.

Surfactant:
・ Nonionic surfactant A (manufactured by Sanyo Chemical Industries, Ltd .; FF-200, polyoxyalkylene alkyl ether, HLB = 12.3)
・ Nonionic surfactant B (manufactured by NOF Corporation; nonionic MN-811, polyoxyalkylene alkyl ether, HLB = 8.3)
・ Nonionic surfactant C (Daiichi Kogyo Seiyaku Co., Ltd .; Neugen XL-70, polyoxyalkylene branched decyl ether, HLB = 13.1)
・ Nonionic surfactant D (Daiichi Kogyo Seiyaku Co., Ltd .; Neugen XL-100, polyoxyalkylene branched decyl ether, HLB = 14.7)
・ Nonionic surfactant W (polyoxyethylene oleyl ether)

Thickener:
-Thickener A (Toagosei Co., Ltd .; A-7185, polyacrylic acid copolymer (sodium type), solid content ratio 15 to 17% by weight)

Preservative:
· Preservative A (organic nitrogen sulfur compound content 33.3% by weight, N-methyldiethanolamine content 33.3% by weight)

Rust inhibitor:
· Rust inhibitor A (MIPA, monoisopropanolamine)

(Removability of precoat film)
The film removability of the precoat film was evaluated by the same method as in Experimental Example 1.

(Remaining property of precoat film)
The residual property of the precoat film was evaluated by the same method as in Experimental Example 1.

<Experimental Example 3>
The wax emulsion prepared in Experimental Example 1 and the precoat solution obtained in Example B7 were evaluated for coatability on a predetermined substrate. The precoat solution obtained in Example B7 above was also evaluated for the remaining property to a predetermined substrate.

(Applicability of wax emulsion)
The surface of the substrate described in Table 6 was degreased. The wax emulsion was applied to the surface of these substrates by pouring and dried overnight at room temperature (25 ° C.) to form a coating. The adhesion state of the coating was observed visually.
:: The coating was adhered to the entire surface of the substrate (good);
Δ: A part of the surface of the substrate was repelled by coating, but there was no problem in practical use (good);
X: The coating film repelled in the majority of the substrate surface, and there was a problem in practical use (not acceptable).

(Applicability of precoat solution)
The coating property was evaluated by the same method as the method for evaluating the coating property of the above-mentioned wax emulsion except that the pre-coating liquid was used.

(Remaining property of precoat film)
The residual property was evaluated by the same method as the residual property of the precoat film in Experimental Example 1 except that the base material described in Table 6 was used.

The precoating agent for removing a coating film of the present invention is not required to be formed in the coating process performed in the field of manufacturing automobiles, aircraft, agricultural machines, construction machines, railway vehicles, home appliances etc., and in the field of construction of houses and buildings. Facilitate peeling and removal of the coating. Therefore, it is useful for VOC reduction and coating cost reduction in the painting process.

Claims (18)

The precoat agent for coating removal including an acrylic polymer and / or oil modified alkyd resin which contains an acrylate monomer in part as a binder; and a wax. The precoat agent for coating film exfoliation according to claim 1, wherein the acrylic polymer is selected from the group consisting of an acrylate monomer-containing copolymer, a urethane-modified acrylic resin, and an epoxy-modified acrylic resin. 3. The precoat agent for coating film removal according to claim 2, wherein the acrylate monomer-containing copolymer is selected from the group consisting of a vinyl ester compound-acrylate monomer copolymer and an aromatic vinyl compound-acrylate monomer copolymer. The precoat agent for coating film release according to any one of claims 1 to 3, wherein the content of the acrylate monomer contained in the acrylic polymer is 1 to 90% by weight based on the total monomer components. The precoat agent for coating film release according to any one of claims 1 to 3, wherein the content of the acrylate monomer contained in the acrylic polymer is 5 to 80% by weight based on the total monomer components. The precoat agent for coating film release according to any one of claims 1 to 5, wherein the content of the binder is 20 to 600 parts by weight with respect to 100 parts by weight of wax. The precoat agent for coating film peeling according to any one of claims 1 to 6, wherein one or more additives selected from the group consisting of surfactants, thickeners, preservatives and rust inhibitors are included. Precoat agent for paint film peeling. The above-mentioned precoating agent for film peeling further includes a surfactant and a thickener,
The content of the surfactant is 0.01 to 60 parts by weight with respect to 100 parts by weight of wax,
The precoat agent for coating film release according to any one of claims 1 to 7, wherein the content of the thickener is 0.01 to 50 parts by weight with respect to 100 parts by weight of the wax. The above-mentioned precoat agent for paint film peeling further contains a surfactant,
The precoat agent for paint film peeling according to any one of claims 1 to 7, wherein the surfactant comprises polyoxyalkylene alkyl ether and / or polyoxyalkylene alkenyl ether. The content of the polyoxyalkylene alkyl ether is 1 to 20 parts by weight with respect to 100 parts by weight of wax,
The precoat agent for paint film peeling according to claim 9, wherein the content of the polyoxyalkylene alkenyl ether is 10 to 40 parts by weight with respect to 100 parts by weight of the wax. The precoat agent for paint film peeling according to any one of claims 1 to 10, comprising the binder having a water contact angle of 40 ° or more and a hexadecane contact angle of 5 ° or more. The precoat agent for coating film peeling according to any one of claims 1 to 11, comprising the binder having an adhesion of 80/100 or more by a cross cut method based on JIS K5600-5-6. A precoating solution for coating film peeling, in which the coating composition peeling precoating agent according to any one of claims 1 to 12 is dissolved or dispersed in water. The precoat solution for coating film removal according to claim 13, wherein the water content is 70 to 97% by weight based on the whole. A method for removing an unnecessary coating film, wherein a precoat film is formed on the surface of an article which does not require coating with a paint, using the precoating solution for coating film removal according to claim 13 or 14. The method according to claim 15, wherein the surface to which the precoating solution is applied on the article is made of an inorganic material and / or an organic material. The inorganic material is selected from metal and glass,
17. The method of claim 16, wherein the organic material is selected from polymers. The method for removing an unnecessary coating film according to any one of claims 15 to 17, wherein the article is a resin molded body.