JP7075731B2 - Primer composition, its coating method and painted articles - Google Patents

Description

The present invention relates to aqueous primer compositions used in various coatings. In particular, the present invention relates to primer compositions for various coatings on interior / exterior buildings, roofs, ceramic building materials, automobiles, household appliances, plastics, etc., coating methods thereof, and painted articles.

In recent years, exterior wall materials and paints such as siding boards used for the exterior of buildings have become more sophisticated. Fluorine-based paints and inorganic-based paints for the purpose of improving weather resistance are increasingly used. In addition, there are ceramic-modified paints modified with alkyl silicates for the purpose of improving stain resistance, hydrophilic surface treatment agents using photocatalytic action, and the like.

However, in many cases, the paint or primer normally used for repainting does not adhere to these coating films. Therefore, although there is a dedicated primer for the paint or coating film to be repainted, it is difficult to confirm the type of coating film to be repainted at the actual repainting site, and a primer that can be used universally is required. ..

Further, the repainting work is mostly performed in a situation where people live, and there is a strong demand for a water-based painting method with less odor and toxicity.

As a means for solving these problems, a method using a curable composition such as an alkoxysilyl group-containing synthetic resin emulsion, an organosilicate, and a ketimimino group-containing alkoxysilane compound has been proposed (see Patent Document 1).

The method described in this document is very effective especially for inorganic coating films whose adhesion is difficult to secure, but has a problem that it does not adhere to organic coating films such as some fluorine-based paints and urethane-based paints. ..

In addition, there are many documents that combine alkoxysilyl group-containing synthetic resin emulsions, organosilicates, and isocyanate compounds (Patent Documents 2 to 7), but all of them are for top coat applications characterized by low contamination. Not for primer use.

Japanese Unexamined Patent Publication No. 2009-040874 Japanese Unexamined Patent Publication No. 2010-168424 JP-A-2007-0846778 Japanese Unexamined Patent Publication No. 2006-160928 Japanese Unexamined Patent Publication No. 2006-160929 Japanese Unexamined Patent Publication No. 2006-228879 Japanese Unexamined Patent Publication No. 2006-3007098

An object to be solved by the present invention is to provide an aqueous primer having improved adhesion to organic coating films such as fluorine-based and urethane-based coating films while ensuring adhesion to inorganic coating films. ..

As a result of diligent studies on the above-mentioned problems, the inventors have determined a substance that controls the particle size of the alkoxysilyl group-containing synthetic resin emulsion and promotes hydrolysis / condensation of the alkoxysilyl group, an organosilicate and a specific amount of isocyanate compound. It has been found that the addition can ensure the adhesion to the organic coating film while ensuring the adhesion to the inorganic coating film.

That is, the present invention relates to (I) an alkoxysilyl group-containing synthetic resin emulsion, (II) a substance that promotes hydrolysis / condensation of an alkoxysilyl group, and (III) an organosilicate (a compound represented by the following general formula (1) and a compound thereof. (Partially hydrolyzed condensate) and / or a modified product thereof, (IV) isocyanate compound, (V) ketoimino group-containing alkoxysilane compound.
(RO) ₄ Si (general formula 1)
(In the formula, R is the same or different, and the alkyl group has 1 to 4 carbon atoms).
The present invention relates to a primer composition, wherein the amount of (IV) added is 0.6 to 10 parts by weight with respect to 100 parts by weight of the solid content of the synthetic resin emulsion containing (I) alkoxysilyl group.

The primer composition according to claim 1, wherein the (I) alkoxysilyl group-containing synthetic resin emulsion is an alkoxysilyl group-containing acrylic resin emulsion.

The present invention relates to a primer composition having an average particle size of 60 to 160 nm as measured by the dynamic light scattering method of the (I) alkoxysilyl group-containing synthetic resin emulsion.

(II) The present invention relates to a primer composition characterized in that the substance that promotes hydrolysis / condensation of the alkoxysilyl group is an organotin compound.

The present invention relates to a primer composition, wherein the (IV) isocyanate compound is an isophorone diisocyanate system.

The present invention relates to a coating method, which comprises using the primer composition described above.

The present invention relates to a coating method comprising applying an acrylic silicone-based paint on top of the primer composition described above.

The present invention relates to a painted article coated with the primer composition described above.

The present invention relates to a painted article characterized in that an acrylic silicone-based paint is overlaid on the primer composition described above.

According to the present invention, it is possible to obtain an aqueous primer having improved adhesion to organic coating films such as fluorine-based and urethane-based films while ensuring adhesion to inorganic coating films.

Hereinafter, the present invention will be described in detail based on the embodiments thereof.

The present invention relates to (I) an alkoxysilyl group-containing synthetic resin emulsion, (II) a substance that promotes hydrolysis / condensation of an alkoxysilyl group, and (III) an organosilicate (a compound represented by the following general formula (1) and a portion thereof). Hydrolyzed condensate) and / or modified product thereof, (IV) isocyanate compound, (V) ketoimino group-containing alkoxysilane compound.
(RO) ₄ Si (general formula 1)
(In the formula, R is the same or different, and the alkyl group has 1 to 4 carbon atoms).
The primer composition is characterized in that the amount of (IV) added is 0.6 to 10 parts by weight with respect to 100 parts by weight of the solid content of the synthetic resin emulsion containing (I) alkoxysilyl group. ..

(I) alkoxysilyl group-containing synthetic resin emulsion Examples of the alkoxysilyl group-containing synthetic resin emulsion that can be used in the present invention include an alkoxysilyl group-containing acrylic resin emulsion, an alkoxysilyl group-containing urethane resin emulsion, and an alkoxysilyl group-containing fluorine resin emulsion. Examples thereof include, but are not limited to, an alkoxysilyl group-containing epoxy resin emulsion, an alkoxysilyl group-containing polyester resin emulsion, an alkoxysilyl group-containing alkyd resin emulsion, and an alkoxysilyl group-containing melamine resin emulsion. In addition, these may be used alone or in combination of two or more. Among these, the alkoxysilyl group-containing acrylic resin emulsion is advantageous in terms of cost, high degree of freedom in resin design, and the like.

The alkoxysilyl group-containing acrylic resin emulsion is obtained by radical copolymerizing (A) an acrylic monomer, (B) an alkoxysilyl group-containing monomer, and (C) a monomer copolymerizable with these. Can be used.

Specific examples of the acrylic monomer (A) include methyl (meth) acrylate, ethyl (meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, and iso-butyl (meth) acrylate. tert-butyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) methacrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) Examples include acrylate and isovonyl (meth) acrylate.

In particular, when 60% by weight or more of a methacrylic acid ester having an alkyl group having 4 or more carbon atoms and / or a cycloalkyl group is used, the storage stability of the emulsion is greatly improved.

(B) The alkoxysilyl group-containing monomer is (b1) formula R ¹ R ² _(3-n) SiX _n (in the formula, R ¹ is a monovalent organic group having a polymerizable double bond, and R ² is carbon. An alkyl group having a number of 1 to 4, X is an alkoxyl group having 1 to 4 carbon atoms, n is an organic silicon compound represented by 2 or 3), having 2 or 3 alkoxyl groups, and a reactive double bond. It is a compound having. Specific examples thereof include vinyltrimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, vinyltriethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, and γ- (meth) acryloxipropyltripropoxy. Silane, γ- (meth) acryloxypropyltributoxysilane, vinylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, vinylmethyldiethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropylmethyldipropoxysilane, γ- (meth) acryloxypropylmethyldibutoxysilane and the like can be mentioned, and these can be used alone or in combination of two or more. Among them, X is particularly preferably having 2 to 4 carbon atoms from the viewpoint of storage stability of the emulsion.

By using 0.5 to 30 parts by weight, preferably 1 to 15 parts by weight, with respect to 100 parts by weight of the shell portion in the core / shell type emulsion, the shell portion is highly crosslinked, and the weather resistance and water resistance are improved. At the same time, the adhesion to the substrate is also improved.

Further, in the formula (b2), R ³ R ⁴ _(3-a) SiY _a (in the formula, R ³ is a monovalent organic group having a polymerizable double bond, R ⁴ is an alkyl group having 1 to 4 carbon atoms, and Y is an alkyl group having 1 to 4 carbon atoms. The organic silicon compound represented by an alkoxyl group having 1 to 4 carbon atoms, where a is an integer of 1 or 2 having a relationship of a <n) has 1 or 2 alkoxyl groups and has a reactive double bond. It is a compound that has. Specific examples thereof include vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxipropylmethyldiethoxysilane, and γ- (meth) acryloxipropyl. Methyldipropoxysilane, γ- (meth) acryloxylpropylmethyldibutoxysilane, vinyldimethylmethoxysilane, vinyldimethylethoxysilane, γ- (meth) acryloxipropyldimethylethoxysilane, γ- (meth) acryloxipropyldimethylmethoxy Examples thereof include silane, γ- (meth) acryloxypropyldimethylpropoxysilane, and γ- (meth) acryloxypropyldimethylbutoxysilane, and these can be used alone or in combination of two or more.

By using these in an amount of 0 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the core portion in the core / shell type emulsion, a loose crosslinked structure is introduced in the core portion and the flexibility is impaired. Water resistance and coating strength can be improved without any problem.

It is preferable that the number of carbon atoms X and Y of the alkoxyl groups (b1) and (b2) have an X> Y relationship in terms of adhesiveness, tackiness, flexibility, and storage stability.

Unlike (A) and (B), the component (C) is not particularly limited as long as it can be copolymerized with these components. Specific examples thereof include aromatic hydrocarbon-based vinyl monomers such as styrene, α-methylstyrene, chlorostyrene, 4-hydroxystyrene, and vinyltoluene; vinyl acetate, vinyl propionate, vinyl versaticate, diallyl phthalate, and the like. Vinyl esters and allyl compounds; nitrile group-containing vinyl-based monomers such as (meth) acrylonitrile; epoxy group-containing vinyl-based monomers such as glycidyl (meth) acrylate; 2-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (Meta) acrylate, 2-hydroxyethyl vinyl ether, hydroxystyrene, monomeric 5700 (manufactured by Toa Synthetic Chemical Co., Ltd.), placcelFA-1, placcelFA-4, placcelFM-1, placcelFM-4 (manufactured by Dycel Chemical Co., Ltd.) ), HE-10, HE-20, HP-10, HP-20 (manufactured by Nippon Catalyst Chemical Co., Ltd.), Blemmer PEP series, Blemmer NKH-5050, Blemmer GLM (manufactured by Nippon Yushi Co., Ltd.), hydroxyl group Containing vinyl-based modified hydroxyalkyl vinyl-based monomer such as hydroxyl group-containing vinyl-based monomer; AS-6, AN-6, AA-6, AB-6, AK-5, which are macromonomers manufactured by Toa Synthetic Chemical Co., Ltd. Examples thereof include compounds such as vinyl methyl ether, propylene and butadiene.

Further, a vinyl-based monomer having hydrophilicity can also be used. Examples of the vinyl-based monomer having a hydrophilic group that can be used include sodium styrene sulfonate, sodium 2-sulfoethyl methacrylate, ammonium 2-sulfoethyl methacrylate, and a vinyl-based monomer having a polyoxyalkylene chain. The vinyl-based monomer having a polyoxyalkylene chain is not limited, but an acrylic acid ester or a methacrylic acid ester having a polyoxyalkylene chain is preferable, and specific examples thereof are Blemmer PE-90 and PE- manufactured by Nippon Oil & Fats Co., Ltd. 200, PE-350, AE-90, AE-200, AE-350, PP-500, PP-800, PP-1000, AP-400, AP-550, AP-800, 700PEP-350B, 10PEP-550B, 55PET-400, 30PET-800, 55PET-800, 30PPT-800, 50PPT-800, 70PPT-800, PME-100, PME-200, PME-400, PME-1000, PME-4000, AME-400, 50POEP- 800B, 50AOEP-800B, AEP, AET, APT, PLE, ALE, PSE, ASE, PKE, AKE, PNE, ANE, PNP, ANP, PNEP-600, Light Ester 130MA, 041MA, MTG, manufactured by Kyoeisha Chemical Co., Ltd. Light Ester EC-A, MTG-A, 130A, DPM-A, P-200A, NP-4EA, NP-8EA, EHDG-A, MA-30, MA-50, MA-100, manufactured by Nippon Ester Co., Ltd. MA-150, RMA-1120, RMA-564, RMA-568, RMA-506, MPG130-MA, Antox MS-60, MPG-130MA, RMA-150M, RMA-300M, RMA-450M, RA-1020, RA -1120, RA-1820, NK-ESTER M-20G, M-40G, M-90G, M-230G, AMP-10G, AMP-20G, AMP-60G, AM-90G, manufactured by Shin-Nakamura Chemical Industry Co., Ltd. LA and the like can be mentioned.

Further, a monomer having two or more polymerizable unsaturated bonds such as polyethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, triallyl cyanurate, allyl (meth) acrylate, and divinylbenzene is used. It is also possible. In this case, the structure has a crosslink inside the generated particles, and the water resistance of the formed coating film is improved.

Further, trifluoro (meth) acrylate, pentafluoro (meth) acrylate, perfluorocyclohexyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, β- (perfluorooctyl) ethyl (meth) acrylate, etc. It is also possible to impart a high degree of water repellency and oil repellency by using the fluorine-containing vinyl-based monomer.

Further, it is also possible to impart crosslinkability by using a carbonyl group-containing vinyl-based monomer such as diacetone acrylamide and methyl vinyl ketone and blending a compound containing a hydrazine and / or a hydrazide group. The water resistance of the coated coating is improved.

In particular, when a hydroxyl group-containing vinyl-based monomer and / or a vinyl-based monomer having a polyoxyalkylene chain is used in an amount corresponding to 0.5 to 20% by weight of the emulsion particles, the stability of the alkoxysilyl group is impaired. It is possible to improve the adhesiveness to the substrate and further improve the mechanical stability and the chemical stability of the emulsion. Among them, a vinyl-based monomer having a polyoxyalkylene chain having a hydroxyl group at the terminal is particularly effective.
If the amount used is less than 0.5% by weight, mechanical stability and chemical stability are inferior, and if it exceeds 20% by weight, water resistance is lowered. Particularly preferably, it is 1 to 5% by weight.

Further, the average particle size of the emulsion measured by the dynamic light scattering method is preferably 20 to 500 nm, more preferably 50 to 300 nm. When the average particle size is 20 nm or less, the stability of the coating material decreases if the viscosity increases too much. Further, if it exceeds 500 nm, the water resistance deteriorates.

Further, in the present invention, the adhesiveness is particularly improved by adjusting the average particle size to 60 to 160 nm.

Next, a method for producing an emulsion will be described.

It is obtained by emulsion polymerization of a mixture consisting of the components (A), (B) and (C) by an emulsion polymerization method in a public land.

Further, in the production of the core / shell type emulsion, first, a mixture composed of the components (A), (b2) and (C) is emulsion-polymerized by a public emulsion polymerization method with the mixture composed of the components (A), (b2) and (C) as the first stage, and the core component obtained is obtained. In the presence of, the mixture consisting of (A), (b1) and (C) is emulsion-polymerized to introduce a shell component. The polymerization in each component of the core portion and the shell portion may be divided into several times.

Further, when the core component is sufficiently hydrophobic with respect to the shell component, the desired composition can be obtained even if the shell component is polymerized first.

For emulsion polymerization, commonly used ionic or nonionic surfactants can be used.

In the present invention, it is preferable to use a reactive surfactant having a polymerizable double bond in one molecule as the surfactant in terms of water resistance and weather resistance. Further, particularly when a reactive surfactant having a polyoxyalkylene group in the molecule is used, the mechanical stability can be improved.

Specific examples of such a reactive surfactant include, for example, ADEKA Adecaria Soap ER-10, ER-20, ER-30, ER-40, SR-05, SR-10, SR-20, manufactured by ADEKA Corporation. SR-1025, SR-2025, SR-3025, NE-10, NE-20, NE-30, NE-40, SE-10N), Antox-MS-60, RMA-1120, RMA manufactured by Nippon Emulsorium Co., Ltd. -564, RMA-568, RMA-506, Aqualon KH-05, KH-10, RN-20, RN-30, RN-50, RN-2025, HS-10, HS-, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. 20, HS-1025, BC05, BC10, BC0515, BC1025, AR-10, AR-20, AR-1025, AR-2020, AN-10, AN-20, AN-30, AN5065, Sanyo Kasei Kogyo Co., Ltd. Eleminor JS-2, JS-20, RS-30, RS-3000, Kao Co., Ltd. Latemul S-180, S-180A, PD-104, PD-420, PD-430, PD-430S, etc. Be done.

The surfactant can be used alone or in combination of two or more, and the amount thereof is 10 parts by weight or less, preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the total amount of the monomer. be.

The polymerization initiator is not particularly limited, but it is desirable to use a redox system as the polymerization initiator in order to carry out the polymerization more stably. Further, in order to maintain the stability of the mixed solution during the polymerization and to carry out the polymerization stably, the temperature is preferably 70 ° C. or lower, preferably 40 to 65 ° C., and the pH is preferably adjusted to 5 to 9.

As an initiator used in the redox system, a combination of a persulfate or peroxide and various reducing agents is preferable. In particular, a combination of an organic peroxide such as t-butyl hydroperoxide, benzoyl peroxide or cumene hydroperoxide with Longalite, Brugolitte FF-6 or thiourea dioxide is preferable.

As the reducing agent, Bruggolitte FF-6 and thiourea dioxide, which do not generate formaldehyde, are particularly preferable in consideration of the environment.

The amount of the polymerization initiator used is 0.01 to 10 parts, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the total amount of the monomer. If the amount of the polymerization initiator used is less than 0.01 parts by weight, the polymerization may be difficult to proceed, and if it exceeds 10 parts by weight, the molecular weight of the produced polymer tends to decrease. be.

Further, in order to stably impart the catalytic activity of the polymerization initiator, a compound containing divalent iron ions such as iron sulfate and a chelating agent such as disodium ethylenediamine tetraacetate may be used. The amount of the chelating agent used is 0.0001 to 1 part by weight, preferably 0.001 to 0.5 part by weight, based on 100 parts by weight of the total amount of the monomer.

It is also possible to add known chain transfer agents to regulate the molecular weight of the polymer.

The resin solid content concentration in the alkoxysilyl-containing acrylic resin emulsion is preferably 20 to 70% by weight, more preferably 30 to 60% by weight. When the resin solid content concentration exceeds 70% by weight, the viscosity of the system increases remarkably, so that it is difficult to remove the heat generated by the polymerization reaction, or it takes a long time to take out from the polymerizer. It tends to be necessary. Further, when the resin solid content concentration is less than 20% by weight, there is no problem in terms of the polymerization operation, but the amount of resin generated by one polymerization operation is small, which is economically disadvantageous.

The average particle size of the alkoxysilyl-containing acrylic resin emulsion used in the present invention measured by a dynamic light scattering method is preferably 20 to 500 nm, more preferably 50 to 300 nm. When the average particle size is 20 nm or less, the stability of the coating material decreases if the viscosity increases too much. Further, if it exceeds 500 nm, the water resistance deteriorates.

Further, in the present invention, the adhesiveness is particularly improved by adjusting the average particle size to 60 to 160 nm. The average particle size can be adjusted by the amount of emulsifier charged in the initial stage of polymerization.

Specific examples of the alkoxysilyl group-containing urethane resin emulsion include Takelac WS-7000, WS-5000, WS-5070X, WS-5100, WS-4000 manufactured by Mitsui Chemicals Polyurethane Co., Ltd.

Specific examples of the alkoxysilyl group-containing epoxy resin emulsion include ADEKA Resins EM-0477 and EM-0487 manufactured by ADEKA Corporation.

Further, other resin systems can also be obtained by reacting various functional groups with a silane coupling agent.

For example, a method of reacting a glucidyl group-containing resin, a carboxyl group-containing resin, and an isocyanate group-containing resin with an amino-based silane coupling agent, a hydroxyl group-containing resin, an amino group-containing resin, and a carboxyl group-containing resin with an epoxy-based silane coupling agent and isocyanate. Examples thereof include a method of reacting a based silane coupling agent. These may be reacted with a resin emulsified in advance, or may be emulsified after the reaction is completed.

The obtained emulsion composition may be supplemented with pigments (titanium dioxide, calcium carbonate, kaolin clay, talc, barium sulfate, white carbon, carbon, petals, ocher, cyanine blue, etc.), which are usually used for paints, as required. Additives commonly used in paints such as film aids, colloidal silica, plasticizers, solvents, dispersants, wetting agents, preservatives, antifreeze agents, light stabilizers, UV absorbers, defoamers, etc. can also be added. can.

(II) A substance that promotes hydrolysis / condensation of an alkoxysilyl group As a substance that promotes hydrolysis / condensation of an alkoxysilyl group that is a component (II) in the present invention (hereinafter referred to as a curing catalyst), an organic metal compound or an acidic substance is used. A catalyst or a basic catalyst is used. In particular, organotin compounds are preferred.

Specific examples of the organic tin compound include dibutyltin dilaurate, dibutyltin dimarate, dibutyltin dioleylmalate, dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dimethoxide, dibutyltin thioglycolate, and dibutyltin bisisononyl 3-mercaptopro. Pionate, Dibutyltin bisisooctylthioglycolate, Dibutyltin bis2-ethylhexylthioglycolate, Dibutyltin bisdodecylmercaptide, Dibutyltin bisdodecylmercaptide, Dioctyltin bisdodecylmercaptide, Dimethyltin bis (octylthiogul) Cole acid ester) salt, tin octylate and the like can be mentioned.

Among them, dibutyltin thioglycolate, dibutyltin bisisononyl 3-mercaptopropionate, dibutyltin bisisooctylthioglycolate, dibutyltin bis2-ethylhexylthioglycolate, dimethyltin bisdodecyl from the viewpoint of stability in water. Mercaptide-based products such as mercaptide, dibutyltin bisdodecyl mercaptide, dioctyltin bisdodecyl mercaptide, and dimethyltin bis (octylthioglucolic acid ester) salt are preferable.

The method of addition is not particularly limited, but a method of mixing with a substance having a surface activity in advance and then adding the substance is preferable from the viewpoint of miscibility with the emulsion and the development of gloss of the coating film.

The amount of the curing catalyst added is 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, and particularly preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the solid content of the emulsion. If it is less than 0.01 parts by weight, the curing activity is low and sufficient adhesion and water resistance cannot be ensured. If it exceeds 10 parts by weight, the pot life of the paint is shortened, and the water resistance and weather resistance of the coating film are lowered.

(III) Organosilicate and its modified product Organosilicate is a compound containing a hydrolyzable silicon group, which is a compound represented by the general formula 1, and is an inorganic substance of a coating film obtained by adding to an emulsion. Greatly improves adhesion to system substrates and stain resistance.

(RO) ₄ Si (general formula 1)
(In the formula, R is the same or different, and the alkyl group has 1 to 4 carbon atoms).

Specific compounds thereof include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra-i-butoxysilane, tetra-t-butoxysilane and Examples thereof include partial hydrolysis / condensate thereof.

The above compounds may be used alone or in combination of two or more. Also, organosilicates containing different alkoxysilyl groups in the same molecule can be used. For example, methyl ethyl silicate, methyl propyl silicate, methyl butyl silicate, ethyl propyl silicate, propyl butyl silicate and the like. The ratio of these substituents can be arbitrarily changed from 0 to 100%, and by adjusting the ratio, the pot life after addition into the emulsion can be adjusted.

Further, although it has been described that the partially hydrolyzed / condensate of these silicates can also be used, the degree of condensation is preferably about 1 to 20. A more preferable range of the degree of condensation is 3 to 15.

Since the organosilicate has low miscibility with the emulsion, it is preferable to emulsify it in water with a surface-active substance in advance and add it, or to directly add a mixture of the surface-active substance and the organosilicate.

The surface-active substance is a substance having a hydrophilic group and a hydrophobic group in the molecule, and is capable of emulsifying and dispersing an organosilicate and a curing catalyst in water. Specifically, it is an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, or the like, and may be used alone or in combination of two or more.

Among these, as a surfactant that can be particularly preferably used, it is more desirable to use a nonionic surfactant having no ionic group.

Further, as another method for improving miscibility, a hydrophilic group such as a polyoxyalkylene chain or an amino group can be introduced to modify the organosilicate so that it becomes water-soluble or self-water-dispersible.

The amount of these organosilicates and / or modified products added thereof is 0.1 to 40 parts by weight, preferably 1 to 30 parts by weight, and particularly preferably 5 to 15 parts by weight, based on 100 parts by weight of the emulsion resin solid content. .. If it is less than 0.1 part by weight, sufficient adhesiveness cannot be ensured, and if it exceeds 40 parts by weight, the coating film tends to be brittle and the adhesiveness tends to decrease.

(IV) Isocyanate compound The isocyanate compound is, for example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (4,4'-diphenylmethane diisocyanate). MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), methylcyclohexyldiisocyanate (H6TDI), 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,3-bis (isocyanatomethyl) cyclohexane (H6XDI), Tetramethylxylylene diisocyanate (TMXDI), 2,2,4-trimethylhexamethylene diisocyanate (TMHDI), hexamethylene diisocyanate (HDI), norbornene diisocyanate (NBDI), 2,4,6-triisopropylphenyldiisocyanate (TIDI), 1,12-Diisocyanate dodecane (DDI), 2,4, -bis- (8-isocyanate octyl) -1,3-dioctylcyclobutane (OCDI), n-pentane-1,4-diisocyanate and modified isocyanurates thereof. , Adduct modified product, Bullet modified product, Allophanate modified product, etc. Further, these isocyanate groups may be masked with a blocking agent (phenol, εcaprolactam, etc.).

From the viewpoint of weather resistance, xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), methylcyclohexyldiisocyanate (H6TDI), 4,4'-dicyclohexylmethane diisocyanate (H12MDI), 1,3-bis (isocyanatomethyl) cyclohexane (H6XDI) ) Or other non-yellowing or non-yellowing is preferable.

Further, from the viewpoint of storage stability of the formulation, an isophorone diisocyanate (IPDI) system is particularly preferable.

Further, one or more of these isocyanate groups are modified with a polyalkylene oxide group, a carboxyl group, or the like to make them water-soluble and / or water-dispersible, which is particularly preferable in this system.

These are generally marketed as cross-linking agents, and for example, Baihijour 3100, Baihijour 302, Baihijour 304, Baihijour 305, Baihijour XP2451 / 1, Baihijour XP2487 / 1, Baihijour XP2547, Baihijour XP2655, Baihijour, manufactured by Sumika Cobestro Urethane Co., Ltd. XP2700, Death Module DN, Death Module DA-L, Baihijour 401-70, Baihijour XP2759, Baihijour 2336, Baihijour LS2150 / l, Baihijour BL5335, Baihijour BL XP2706, Implafix 2794XP, Baihijour BL116, Baihijour BL5140, Baihijour BL5235 , Bihydrol TPLS2153, Takenate WD-220 manufactured by Mitsui Chemicals, Inc., Takenate WD-240, Takenate WD-720, Takenate WD-725, Takenate WD-726, Takenate WD-730, Takenate WB-700, Takenate WB-720, Takenate WB-730, Takenate WB-920, Tosoh Corporation Aquanate 105, Aquanate 100, Aquanate 110, Aquanate 140, Aquanate 200, Aquanate 210, Aquanate 120, Asahi Kasei Corporation Duranate WB40 -100, Duranate WB40-80D, Duranate WT20-100, Duranate WT30-100, Duranate WL70-100, Duranate WR80-70P, Duranate WE50-100, Duranate 44-L70G, VENCOREX Easaqua L600, EasaquaXD80 Examples thereof include Easaqua M502, Easaqua M501, Easaqua WAT-4, Easaqua WAT-3, and Easaqua XD870.

The amount of these isocyanate compounds added is 0.6 to 10 parts by weight, preferably 1 to 5 parts by weight, and particularly preferably 1 to 2 parts by weight, based on 100 parts by weight of the emulsion resin solid content. Sufficient adhesion cannot be ensured at 0.6 parts by weight or less, and at 10 parts by weight or more, the pot life is shortened and the appearance of the coating film is also deteriorated.

(V) Ketoimino Group-Containing Alkoxysilane Compound The ketoimino group-containing alkoxysilane compound is a compound having a ketoimino group and an alkoxysilyl group obtained by reacting a primary amino group in a molecule with a ketone. For example, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine and 3-trimethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine can be mentioned. Examples of these commercially available products include KBE-9103 manufactured by Shin-Etsu Chemical Co., Ltd., Sara Ace S340 manufactured by Chisso Co., Ltd., and Z-6860 manufactured by Toray Dow Corning Co., Ltd.

By adding these ketoimino group-containing alkoxysilane compounds, the adhesiveness to the substrate is further improved, and when a different type of paint is further applied on the substrate, the selectivity of the paint is reduced.

The amount of these ketoimino group-containing alkoxysilane compounds added is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, and particularly preferably 1 to 5 parts by weight, based on 100 parts by weight of the emulsion resin solid content. be. Sufficient adhesion cannot be ensured at 0.1 parts by weight or less, and at 20 parts by weight or more, coloring is severe and the appearance of the obtained coating film is deteriorated.

(A water-soluble and / or water-dispersible curing agent having a reactive functional group (excluding an isocyanate group) and a hydrophilic group in the molecule)
A water-soluble and / or water-dispersible curing agent having a reactive functional group (excluding an isocyanate group) and a hydrophilic group in the molecule is a substance having a reactive functional group other than the isocyanate group and having a surface activity. That is. Due to its surface activity, the organosilicate and curing catalyst are emulsified and dispersed in the emulsion, and the reactive functional group reacts with the resin component and / or other compounding agent contained in the emulsion, as well as the reactive functional group itself. This improves adhesion and water resistance. The reactive functional group may be the same as the hydrophilic group or the hydrophobic group. Specific examples of the reactive functional group include an epoxy group, a carbodiimide group, an alkoxysilyl group, an oxazoline group, a hydrazide group, an allyl group, a propenyl group, a (meth) acryloyl group, a vinyl group and the like.

Of these, an epoxy group, a carbodiimide group, and an alkoxysilyl group are particularly effective for adhesion to a substrate and are particularly desirable.

Many epoxy group-containing compounds are commercially available, for example, Denacol EX-611, EX-612, EX-614, EX-614B, EX-622, EX-512, manufactured by Nagase Chemtech Co., Ltd. EX-521, EX-411, EX-421, EX-301, EX-313, EX-314, EX-321, EX-211, EX-810, EX-811, EX-851, EX-821, EX- 830, EX-832, EX-841, EX-861, EX-911, EX-941, EX-920, EX-921, EX-931, EX-145, EX-171, EX-701, Kyoeisha Chemical Co., Ltd. ) Epolite 40E, Epolite 100E, Epolite 200E, Epolite 400E, Epolite 70P, Epolite 200P, Epolite 400P, Epolite 1500NP, Epolite 80MF, Epolite 100MF, Sakamoto Pharmaceutical Co., Ltd. SR-NPG, SR-16H, SR-TMP , SR-TPG, SR-4PG, SR-2EG, SR-8EG, SR-8EGS, SR-GLG, SR-DGE, SR-4GL, SR-4GLS, Epiol BE-200, G- Examples include 100, E-100, E-400, E-1000, P-200, NPG-100, TMP-100, Epiol OH and the like.

Examples of the carbodiimide group-containing compound include water-soluble or self-emulsifying carbodiimide compounds described in JP-A-8-59303.

In this method, one or more of the polyfunctional isocyanates are subjected to a decarbon dioxide condensation reaction to form a carbodiimide, and the residual isocyanate group at the terminal is sealed with a hydrophilic group. Examples of the hydrophilic group to be sealed include a residue of an alkyl sulfonate, a quaternary salt of a residue of a dialkylamino alcohol, and a residue of a polyoxyalkylene having a blocked alkoxy group terminal.

These are commercially available as aqueous resin cross-linking agents, and are, for example, Carbodilite V-02, V-04, V-06, V-02-L2, E-01, E-02, manufactured by Nisshinbo Chemical Co., Ltd. There are E-03, E-04, E-05 and the like.

Further, there are V-02B, V-04B, V-04K, Elastostab H01 and the like which do not contain water.

Examples of the alkoxysilyl group-containing compound include A-1230, MAC-2101, and MAC-2301 manufactured by Momentive Performance Materials Japan GK.

The oxazoline group-containing compound is commercially available as an aqueous cross-linking agent, and for example, Epocross WS-500, K-2010E, K-2020E, K-2030E, K-1010E, K-1020E, K- of Nippon Shokubai Co., Ltd. Examples include 1030E.

Examples of the hydrazide group-containing compound include carbohydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide, aminopolyacrylamide and the like.

(Topcoat paint)
The topcoat paint to be applied over the primer composition of the present invention is not particularly limited, and refers to all the paints and paints applied for the purpose of protecting the object to be coated and imparting aesthetic appearance. Not only thin film type paints generally called paints, but also JIS A 6909 (building finish coating material), JIS A 6021 (building coating film waterproofing material), JIS A 6916 (building base adjustment coating material). ) Etc. are also included, such as thick film type coating materials, left-handed materials, and civil engineering materials.

However, an acrylic silicone-based paint is suitable, particularly considering the adhesion to the primer composition of the present invention. The acrylic silicone-based paint is a paint containing an acrylic resin modified with a silicon-containing compound. Higher weather resistance than general acrylic resin paints. The modification with the silicon compound may be performed at the stage of resin synthesis, after the completion of synthesis, or at the stage of coating.

Among the acrylic silicone-based paints, those using an acrylic resin containing an alkoxysilyl group are particularly excellent in adhesion, stain resistance, and water resistance.

(Painted goods)
The coated article refers to all painted parts that have been primer-treated with the primer composition of the present invention and further finished with the topcoat paint. Although not particularly limited, for example, building interior / exterior members, roofing materials, ceramic building materials, automobile parts, home appliance parts, plastic articles and the like can be mentioned.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto.

(Synthesis Example 1)
In a reaction vessel equipped with a stirrer, a reflux cooler, a nitrogen gas introduction tube and a dropping funnel, 160 parts by weight of deionized water, 1.4 parts by weight of Newcol-707SF (manufactured by Nippon Embroidery Co., Ltd.), 5% sodium hydrogen carbonate 1.0 part by weight of the aqueous solution was charged, and the temperature was raised to 50 ° C. while introducing nitrogen gas. After heating, 2.0 parts by weight of 7% t-butyl hydroperoxide aqueous solution, 1.1 parts by weight of 20% Bruggolite FF-6 aqueous solution, ferrous sulfate heptahydrate (0.10%) / ethylenediamine tetra To 200 parts by weight of the monomer mixture shown in the core part of Table 1 (E-1), 1.4 parts of a mixed aqueous solution of disodium acetate (0.40%) was added, and Adecaria Soap SR-1025 (manufactured by ADEKA Co., Ltd.): Add 12 parts by weight of active ingredient), 1.9 parts by weight of Adecaria Sodium ER-20 (manufactured by ADEKA Co., Ltd .: 75% of active ingredient), and 71 parts by weight of deionized water to emulsify the monomer emulsion for 200 minutes. I added it at a constant speed. During that time, 2.2 parts by weight of a 7% t-butyl hydroperoxide aqueous solution and 1.8 parts by weight of a 2.5% Burggolite FF-aqueous solution were added in 3 portions. After the addition of the monomer emulsion was completed, polymerization was carried out 1 hour later. Further, 0.6 parts by weight of a 7% t-butyl hydroperoxide aqueous solution, 2.2 parts by weight of a 2.5% Bruggolite FF-aqueous solution, and ferrous sulfate heptahydrate (0.10%) / ethylenediamine tetraacetic acid. After adding 1.4 parts of the disodium (0.40%) mixed aqueous solution, 12 parts by weight of Adecaria Soap SR-1025 and 12 parts by weight of Adecaria Soap were added to 200 parts by weight of the monomer mixture shown in the shell part of Table 1 (E-1). An emulsified monomer emulsified solution containing 1.9 parts by weight of ER-20 and 71 parts by weight of deionized water was added at a constant velocity over 200 minutes. During that time, 2.4 parts by weight of a 7% t-butyl hydroperoxide aqueous solution and 3.4 parts by weight of a 2.5% Burggolite FF-6 aqueous solution were added in 4 portions. After the addition of the monomer emulsion was completed, polymerization was carried out 1.5 hours later. After adding 22 parts of a 5% aqueous sodium hydrogen carbonate solution to the obtained synthetic resin emulsion, the solid part was adjusted to 50% with deionized water (E-1). As a result of measuring the particle size by the dynamic light scattering method, it was about 200 nm.

(Synthesis Example 2)
In a reaction vessel equipped with a stirrer, a reflux cooler, a nitrogen gas introduction tube and a dropping funnel, 360 parts by weight of deionized water, Adecaria soap SR-1025 (manufactured by ADEKA Co., Ltd .: active ingredient 25%) 9.2 weight The temperature was raised to 50 ° C. by charging 1.0 part by weight of a 5% sodium hydrogen carbonate aqueous solution and introducing nitrogen gas. After raising the temperature, 20 parts by weight of the monomer mixture shown in the core part of Table 1 (E-2), 2.0 parts by weight of a 7% t-butyl hydroperoxide aqueous solution, ferrous sulfate heptahydrate (0. 2.8 parts by weight of a mixed aqueous solution of 10%) / disodium ethylenediamine tetraacetate (0.40%) and 1.4 parts by weight of a 10% aqueous solution of Sulfuric acid FF-6 were added, and polymerization was carried out for 30 minutes.

Further, after adding 1.0 part by weight of a 7% t-butyl hydroperoxide aqueous solution and 2.8 parts by weight of a 2.5% Brugolitte FF-aqueous solution, the monomer mixture 380 shown in the shell portion of Table 1 (E-2) is added. Adecaria soap SR-1025 34.2 parts by weight, Adecaria soap ER-20 11.4 parts by weight, and 151 parts by weight of deionized water were added to the parts by weight, and the emulsified monomer emulsified solution was added at a constant speed over 380 minutes. .. During that time, 3.1 parts by weight of a 7% t-butyl hydroperoxide aqueous solution and 5.4 parts by weight of a 2.5% Burggolite FF-6 aqueous solution were added in 5 portions. After the addition of the monomer emulsion was completed, polymerization was carried out 1.5 hours later. After adding 28 parts of a 5% aqueous sodium hydrogen carbonate solution to the obtained synthetic resin emulsion, the solid part was adjusted to 40% with deionized water (E-2). As a result of measuring the particle size by the dynamic light scattering method, it was about 100 nm.

(Synthesis Example 3)
In a reaction vessel equipped with a stirrer, a reflux cooler, a nitrogen gas introduction tube and a dropping funnel, 152 parts by weight of deionized water, 0.4 weight of Adecaria Sodium SR-1025 (manufactured by ADEKA Co., Ltd .: active ingredient 25%) A portion of 1.0 part by weight of a 5% sodium hydrogen carbonate aqueous solution was charged, and the temperature was raised to 50 ° C. while introducing nitrogen gas. After raising the temperature, 2.0 parts by weight of a 7% t-butyl hydroperoxide aqueous solution, a mixed aqueous solution of ferrous sulfate heptahydrate (0.10%) / disodium ethylenediamine tetraacetate (0.40%) 2. 8 parts, 10% Bruggolite FF-6 aqueous solution 1.4 parts by weight, was added, and Adecaria Sodium SR-1025 (manufactured by ADEKA Co., Ltd .: active ingredient) was added to the monomer mixture shown in the core part of Table 1 (E-3). 25%) 9.0 parts by weight, Adecaria Sodium ER-20 (manufactured by ADEKA Co., Ltd .: active ingredient 75%) 1.6 parts by weight and 57 parts by weight of deionized water, and emulsified monomeric emulsion over 160 minutes. Added constant velocity. During that time, 1.2 parts by weight of a 7% t-butyl hydroperoxide aqueous solution and 2.4 parts by weight of a 2.5% Burggolite FF-6 aqueous solution were added in two portions. After the addition of the monomer emulsion was completed, polymerization was carried out 2 hours later. During that time, 1.2 parts by weight of a 7% t-butyl hydroperoxide aqueous solution and 1.8 parts by weight of a 2.5% Burggolite FF-6 aqueous solution were added in 3 portions.

Further, after adding 1.2 parts by weight of a 7% t-butyl hydroperoxide aqueous solution and 3.2 parts by weight of a 2.5% Bruggolite FF-6 aqueous solution, the monomers and chains shown in the shell part of Table 1 (E-3) are added. 14 parts by weight of Adecaria Soap SR-1025 (manufactured by ADEKA Co., Ltd .: active ingredient 25%), 2.4 parts by weight of Adecaria Soap ER-20 (manufactured by ADEKA Co., Ltd .: active ingredient 75%) and 86 parts by weight of deionized water was added and the emulsified monomer emulsified solution was added at a constant velocity over 240 minutes. During that time, 2.0 parts by weight of a 7% t-butyl hydroperoxide aqueous solution and 3.2 parts by weight of a 2.5% Burggolite FF-6 aqueous solution were added in two portions. After the addition was completed, polymerization was carried out 1.5 hours later. During that time, 0.8 parts by weight of a 7% t-butyl hydroperoxide aqueous solution and 1.2 parts by weight of a 2.5% Burggolite FF-6 aqueous solution were added in two portions. After adding 24 parts of a 5% aqueous sodium hydrogen carbonate solution to the obtained emulsion, the solid content concentration was adjusted to 50% with deionized water (E-3).

Table 1 shows the monomer composition used to prepare the synthetic resin emulsion.

(Making the main paint)
Using the synthesized resin emulsions (E-1, E-2), the main paint was prepared according to the formulation shown in Table 2. Table 2 shows the main agent paint composition.

(Manufacturing example of curing agent)
In a container equipped with a stirrer, a reflux condenser, a nitrogen gas introduction tube and a dropping funnel, the components shown in Table 3 were added to (i), (ii), (iii), (iv), (v), (vi), (vi). The mixture was added while stirring in the order of addition of (vii), (viii), (xi), (x), (xi), and (xii) (the unused ones were skipped). After the completion of charging, the mixture was stirred at room temperature for 60 minutes to obtain a curing agent (curing agents 1 to 5). Table 3 shows the curing agent formulation.

(Making the main material for topcoat paint)
Using the synthesized resin emulsion (E-2), a topcoat paint main material was prepared according to the formulation shown in Table 4. Table 4 shows the topcoat paint composition.

(Adhesion evaluation)
The primer composition shown in Table 5 was applied onto the substrate to be evaluated and dried at room temperature for 16 hours. Further, the top coat paint shown in Table 5 was spray-applied twice at an interval of 16 hours in the process. After drying at room temperature for 7 days, 25 2 mm square grid cuts were made, cellophane tape (registered trademark) was attached onto the cuts, and the state when the cells were peeled off was observed. Further, the test piece was immersed in warm water at 40 ° C. for 7 days, dried at room temperature for 24 hours or more, and then the same adhesion test was performed.

The judgment criteria are shown below.
5 No peeling of the coating film is seen.
4 No peeling is observed at the interface between the primer composition and the base material, but peeling is observed at the interface between the primer composition and the topcoat paint.
3 The total peeling at the interface between the primer composition and the base material and the interface between the primer composition and the topcoat paint is less than 10%.
2 The total peeling at the interface between the primer composition and the base material and the interface between the primer composition and the topcoat paint is 10 or more and less than 40%.
1 The total peeling at the interface between the primer composition and the base material and the interface between the primer composition and the topcoat paint is 40 or more and less than 100%.
0 All peel off at the interface between the substrate and the primer composition.

The evaluation results are shown in Table 5. In Comparative Example 1, which is a conventional technique, there is no problem in the adhesiveness to the inorganic base material, but the adhesiveness to the organic base material is not sufficient.

In Comparative Example 2, the particle size of the (I) alkoxysilyl group-containing synthetic resin emulsion was reduced, and the amount of (III) organosilicate and (V) ketoimino group-containing alkoxysilane compound was increased. The effect of improving the adhesiveness of was slight.

In Comparative Example 3, (IV) an isocyanate compound was added, but the amount added was not sufficient, and the adhesion to the acrylic urethane-based coating film was insufficient.

In Comparative Example 4, (IV) an isocyanate compound was added, but if the amount added was too large, the thickening rate would be too high and coating would not be possible.

In Examples 1 to 5, 1% or more of the (IV) isocyanate compound was added as an isocyanate group to 100 parts by weight of the solid content of the (I) alkoxysilyl group-containing synthetic resin emulsion, but all of them were inorganic. There is no change in the adhesion to the coating film, and the adhesion to the organic coating film is sufficiently improved.

As described above, it was confirmed that the primer composition of the present invention has good adhesion to various substrates including organic coating films. Further, it was confirmed that the adhesiveness was further improved by setting the particle size of the (I) alkoxysilyl group-containing synthetic resin emulsion to 50 to 160 nm. Further, it was confirmed that the use of an acrylic silicone-based paint as the topcoat paint is suitable not only for adhesion to the base material but also for coating specifications.

Claims (8)

(I) An alkoxysilyl group-containing synthetic resin emulsion and (II) a substance that promotes hydrolysis / condensation of an alkoxysilyl group, (III) an organosilicate (a compound represented by the following general formula (1) and a partially hydrolyzed condensate thereof). ) And / or a modified product thereof, (IV) an isocyanate compound, and (V) a ketomino group-containing alkoxysilane compound.
(RO) ₄ Si (general formula 1)
(In the formula, R is the same or different, and the alkyl group has 1 to 4 carbon atoms).
The amount of (IV) added is 0.6 to 10 parts by weight with respect to 100 parts by weight of the solid content of the synthetic resin emulsion containing (I) alkoxysilyl group .
A primer composition, wherein the (IV) isocyanate compound is an isophorone diisocyanate system . The primer composition according to claim 1, wherein the (I) alkoxysilyl group-containing synthetic resin emulsion is an alkoxysilyl group-containing acrylic resin emulsion. The primer composition according to claim 1 or 2, wherein the average particle size of the (I) alkoxysilyl group-containing synthetic resin emulsion measured by a dynamic light scattering method is 60 to 160 nm. The primer composition according to any one of claims 1 to 3, wherein the substance that promotes hydrolysis / condensation of the (II) alkoxysilyl group is an organic tin compound. A coating method using the primer composition according to any one of claims 1 to 4 . A coating method comprising applying an acrylic silicone-based paint on the primer composition according to any one of claims 1 to 4 . A painted article coated with the primer composition according to any one of claims 1 to 4 . A coated article, which is obtained by applying an acrylic silicone-based paint on the primer composition according to any one of claims 1 to 4 .