JP2015212346A - Aqueous primer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous primer composition which is high in water resistance and has good adhesiveness to substrate materials, including concrete, aluminum sash and polyvinyl chloride.SOLUTION: An aqueous primer composition contains a polyurethane resin (A) having anionic groups and a polyester-modified polyurethane resin (B). The polyurethane resin (A) having anionic groups is obtained by reacting an organic isocyanate compound (a) with an active hydrogen containing compounds (b) including an active hydrogen containing compound (b-1) having an anionic group to synthesize an isocyanate-containing urethane prepolymer (U) having an anionic group and reacting the urethane prepolymer (U) with a chain extender (c) and/or an adhesiveness imparting agent (d). The polyurethane resin (A) is the main component for formation of a primer coating film (primer layer) and is dispersed in water, and the polyester-modified polyurethane resin (B) serves as a component for improving the adhesiveness of the primer coating film.

Description

  The present invention relates to an aqueous primer composition excellent in water resistance and adhesiveness.

  In the fields of architecture, civil engineering, etc., sealing materials, waterproof materials, and coating materials are widely used for the purpose of airtightness and watertightness. When applying sealing materials, waterproof materials, and coating materials, apply primer as a pretreatment to the base material in order to improve adhesion and adhesion to the base material such as concrete, aluminum sash, and polyvinyl chloride (PVC). Has been done. In particular, even if the adhesion and adhesion of sealing materials, waterproof materials, and coating materials are good, the base material such as concrete, aluminum sash, and vinyl chloride may be soiled with chips, dust, oils and fats, etc. If a sealing material is placed without applying a sealant or a waterproof material or coating material is applied, adhesion failure will occur between the sealing material, waterproof material, coating material and base material. It may peel off from the base material. In order to prevent this peeling, the surface of the base material is removed by applying a primer using a brush, roller, etc., and it has excellent adhesion and adhesion between the sealing material, waterproof material, coating material and the base material. It is important to provide a primer layer.

  Primers widely used for construction and civil engineering often use organic solvents mainly composed of ethyl acetate as a solvent, and the primer can be made water-based from the viewpoint of odor, deterioration of working environment, environmental pollution, etc. For example, Patent Document 1 discloses an aqueous primer composition containing an aqueous polyurethane resin using a polyether polyol. However, when the primer is made aqueous as in Patent Document 1 or the like, it may be inferior in water resistance to a conventional primer using an organic solvent, or may be inferior in adhesion to a base material such as concrete, aluminum sash, or vinyl chloride. There was a problem.

Japanese Patent Laid-Open No. 10-258494

  In view of the above problems, an object of the present invention is to provide an aqueous primer composition having high water resistance and having good adhesion to a base material such as concrete, aluminum sash, and vinyl chloride.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that the aqueous primer composition containing the polyurethane resin (A) having an anionic group and the polyester-modified polyurethane resin (B) has the above problem. The inventors have found that this can be solved, and have completed the present invention. That is, this invention is shown to following (1)-(11).

  (1) An aqueous primer composition containing a polyurethane resin (A) having an anionic group and a polyester-modified polyurethane resin (B).

  (2) The polyurethane resin (A) having the anionic group reacts the organic isocyanate compound (a) with the active hydrogen-containing compound (b) including the active hydrogen-containing compound (b-1) having the anionic group. The aqueous primer composition according to (1), which is obtained by allowing

  (3) The active hydrogen-containing compound (b) in which the polyurethane resin (A) having the anionic group includes the organic isocyanate compound (a) and the active hydrogen-containing compound (b-1) having the anionic group. To obtain an isocyanate group-containing urethane prepolymer (U) having an anionic group, and then reacting at least one of a chain extender (c) and an adhesion promoter (d) (2) An aqueous primer composition as described in 1.

  (4) The organic isocyanate compound (a) is a modified organic polyisocyanate (a-1b) or a mixture of the organic polyisocyanate (a-1a) and the modified organic polyisocyanate (a-1b) (2) or The aqueous primer composition according to (3).

  (5) The aqueous primer composition according to (4), wherein the modified organic polyisocyanate (a-1b) is an isocyanurate-modified organic polyisocyanate.

  (6) The aqueous primer according to any one of (2) to (5), wherein the active hydrogen-containing compound (b) includes the active hydrogen-containing compound (b-1) having the anionic group and a polymer polyol. Composition.

  (7) In any one of (2) to (6), the active hydrogen-containing compound (b) includes the active hydrogen-containing compound (b-1) having the anionic group and a polymer (meth) acrylic polyol. An aqueous primer composition as described.

(8) The aqueous primer composition according to any one of (1) to (7), wherein the polyester-modified polyurethane resin (B) has a tensile strength (N / mm ² ) of 15 N / mm ² or less.

  (9) The aqueous primer composition according to any one of (1) to (8), wherein the elongation percentage (%) at break of the polyester-modified polyurethane resin (B) is 500% or more.

  (10) The aqueous primer composition according to (1) to (9), wherein the polyester-modified polyurethane resin (B) has an average particle size of 50 to 500 nm.

  (11) The aqueous primer composition according to (1) to (10), which is an aqueous primer composition for construction or an aqueous primer composition for civil engineering.

  The water-based primer composition of the present invention has high water resistance and has good adhesion to a base material such as concrete, aluminum sash, and vinyl chloride.

  Hereinafter, the present invention will be described in detail according to embodiments.

  The aqueous primer composition of the present invention is characterized by containing a polyurethane resin (A) having an anionic group and a polyester-modified polyurethane resin (B).

Polyurethane resin having an anionic group (A)
The polyurethane resin (A) having an anionic group is a main component for forming a primer coating film (primer layer) in the aqueous primer composition of the present invention, and is dispersed in water. That is, the form of the polyurethane resin (A) having an anionic group is a dispersion emulsified and dispersed in water.

  The polyurethane resin (A) having an anionic group is obtained by reacting an organic isocyanate compound (a) with an active hydrogen-containing compound (b) containing an active hydrogen-containing compound (b-1) having an anionic group. .

  In particular, an isocyanate group-containing urethane prepolymer having an anionic group by reacting an organic isocyanate compound (a) with an active hydrogen-containing compound (b) including an active hydrogen-containing compound (b-1) having an anionic group ( U) (hereinafter, sometimes simply referred to as “urethane prepolymer (U)”), and further obtained by reacting at least one of a chain extender (c) and an adhesion-imparting agent (d). From the viewpoints of coating film formability, water resistance and adhesion.

As a manufacturing method of the polyurethane resin (A) having an anionic group, a conventionally known method can be used, and there is no particular limitation. Specifically, the manufacturing method including the following steps can be exemplified.
(I) Isocyanate group-containing urethane prepolymer having an anionic group by reacting an organic isocyanate compound (a) with an active hydrogen-containing compound (b) containing an active hydrogen-containing compound (b-1) having an anionic group Step (II) of synthesizing (U) Step of neutralizing an anionic group of an isocyanate group-containing urethane prepolymer (U) having an anionic group using a neutralizing agent (III) An isocyanate group containing an anionic group Step (IV) of emulsifying and dispersing urethane prepolymer (U) in water At least one of isocyanate group-containing urethane prepolymer (U) having an anionic group, chain extender (c), and adhesion-imparting agent (d) Step (V) of reacting to synthesize polyurethane resin (A) having an anionic group An organic solvent was used in steps (I) to (IV). If the step of removing the organic solvent

  (I) Isocyanate group-containing urethane prepolymer having an anionic group by reacting an organic isocyanate compound (a) with an active hydrogen-containing compound (b-1) containing an active hydrogen-containing compound (b-1) having an anionic group The step of synthesizing (U) will be described.

  The isocyanate group-containing urethane prepolymer (U) having an anionic group is composed of an organic isocyanate compound (a) and an active hydrogen-containing compound (b-1) having an anionic group in a reaction vessel made of glass or stainless steel. The active hydrogen-containing compound (b) containing is reacted in a batch or sequentially so that the isocyanate group remains in the urethane prepolymer (U). The ratio of reacting the organic isocyanate compound (a) with the active hydrogen-containing compound (b) is the reaction between the isocyanate group and the active hydrogen (group) (excluding the active hydrogen (group) contained in the anionic group). The molar ratio (isocyanate group / active hydrogen (group)) is preferably 1.2 to 5.0 / 1.0, more preferably 1.2 to 4.0 / 1.0, and particularly preferably 1.3 to 3.0 / 1.0. When the molar ratio is less than 1.2 / 1.0, the viscosity of the urethane prepolymer (U) increases, and a large amount of solvent may be required. Moreover, when the said molar ratio exceeds 5.0 / 1.0, the molecular weight of a urethane prepolymer (U) is small, and the coating-film formation property of a primer coating film may worsen.

  The isocyanate group content in the isocyanate group-containing urethane prepolymer (U) having an anionic group is preferably 1.0 to 20.0% by mass, more preferably 3.0 to 15.0% by mass, and particularly 5. 0-10.0 mass% is preferable. When isocyanate group content is less than 1.0 mass%, the viscosity of a urethane prepolymer (U) becomes high and a large amount of solvent may be needed. Moreover, when isocyanate group content exceeds 20.0 mass%, the coating-film formation property of a primer coating film may worsen.

  The synthesis of the isocyanate group-containing urethane prepolymer (U) having an anionic group is carried out under a nitrogen stream or by previously replacing the air in the reaction vessel with nitrogen in order to avoid the reaction between the isocyanate group and moisture (moisture). It is preferable. Moreover, an organic solvent or a reaction catalyst can be used in the synthesis of the urethane prepolymer (U).

  The organic solvent can be used without limitation as long as it dissolves the urethane prepolymer (U), has affinity (miscibility) with water, and does not have reactivity with isocyanate groups. Specifically, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, methoxypropyl acetate, 3-methoxybutyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, methyl propionate , Ester solvents such as butyl propionate, butyl butyrate, dioctyl adipate and diisopropyl glutarate: ether solvents such as diisopropyl ether, dibutyl ether, dioxane and diethoxyethane: carbonate solvents such as dimethyl carbonate and diethyl carbonate: acetone 2-pentanone, 3-pentanone, 2-hexanone, methyl isobutyl ketone 2-heptanone, 4-heptanone, diisobutyl ketone, isophorone, cyclohexano , Ketone solvents such as methyl cyclohexanone: Polyethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether and diethylene glycol diethyl ether and triethylene glycol dimethyl ether solvents: polyethylene glycol dicarboxylate based solvents such as diethylene glycol diacetate. Any of these may be used alone or in combination of two or more. Of these, organic solvents having a boiling point of 100 ° C. or lower are preferable because of their high volatility and easy removal operation described later. Furthermore, the solubility of the urethane prepolymer (U) is high, and the compatibility with water is excellent. Therefore, ethyl acetate, acetone, and dimethyl carbonate are preferable.

  Specific examples of the reaction catalyst include metal salts of metals such as zinc, tin, zirconium, bismuth, cobalt, manganese, and iron with organic acids such as octenoic acid and naphthenic acid; dibutyltin dilaurate, dioctyltin dilaurate, and the like. A salt of an organic metal with an organic acid; triethylenediamine, triethylamine, tri-n-butylamine, 1,4-diazabicyclo [2,2,2] octane (DABCO), 1,8-diazabicyclo [5,4,0] Examples include known urethanization catalysts of organic amines such as undecene-7 (DBU) and salts thereof. Any of these may be used alone or in combination of two or more.

  The reaction temperature for synthesizing the isocyanate group-containing urethane prepolymer (U) having an anionic group is preferably 30 ° C to 120 ° C, more preferably 50 ° C to 100 ° C, and particularly preferably 60 ° C to 80 ° C.

  Examples of the organic isocyanate compound (a) include an organic polyisocyanate compound (a-1) and an organic monoisocyanate compound (a-2). In this specification, organic polyisocyanate compound (a-1) is divided roughly into organic polyisocyanate (a-1a) and modified organic polyisocyanate (a-1b). Any of these may be used alone or in combination. Among these, since the primer coating film is excellent in water resistance and heat resistance, modified organic polyisocyanate (a-1b) or a mixture of organic polyisocyanate (a-1a) and modified organic polyisocyanate (a-1b) Is preferred.

  The organic polyisocyanate (a-1a) is a compound having two or more isocyanate groups in the compound, specifically, toluene polyisocyanate such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, diphenylmethane polyisocyanate such as 2,2'-diphenylmethane diisocyanate, 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, Phenylene polyisocyanates such as 2,4,6-trimethylphenyl-1,3-diisocyanate, 2,4,6-triisopropylphenyl-1,3-diisocyanate, 1,4-naphthalenediiso Naphthalene polyisocyanate such as anate, 1,5-naphthalene diisocyanate, and other aromatic polyisocyanates include chlorophenylene-2,4-diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyldiphenylmethane-4,4 '-Diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate and the like, and 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4-trimethyl-1, Aliphatic polyisocyanates such as 6-hexamethylene diisocyanate, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, decamethylene diisocyanate, lysine diisocyanate, o-xylylene diisocyanate Cycloaliphatic polyisocyanates such as di-, m-xylylene diisocyanate, p-xylylene diisocyanate, 1,4-cyclohexyl diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. And polyisocyanates such as polymethylene polyphenyl polyisocyanate and crude toluene diisocyanate. Any of these may be used alone or in combination of two or more. Of these, aliphatic polyisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates are preferred.

  The modified organic polyisocyanate (a-1b) is obtained by modifying at least one organic polyisocyanate similar to the organic polyisocyanate (a-1a). Specifically, the modified organic polyisocyanate (a-1b) has at least one uretdione bond, isocyanurate bond, allophanate bond, burette bond, uretonimine bond, carbodiimide bond, urethane bond, urea bond in the compound. Examples include modified organic polyisocyanates. Any of these may be used alone or in combination of two or more. Of these, isocyanurate-modified organic polyisocyanate is preferable because the primer coating film is excellent in water resistance and heat resistance.

  When the organic polyisocyanate (a-1a) and the modified organic polyisocyanate (a-1b) are mixed and used, the molar ratio of isocyanate groups (the number of moles of isocyanate groups in the organic polyisocyanate (a-1a) / 2.0 to 20.0 / 1.0 is preferable, and 4.0 to 10.0 / 1.0 is more preferable in terms of the number of moles of isocyanate groups of the modified organic polyisocyanate (a-1b).

  When the molar ratio of the isocyanate groups of the organic polyisocyanate (a-1a) and the modified organic polyisocyanate (a-1b) is less than 2.0 / 1.0, the primer coating film tends to be hard and the adhesiveness tends to deteriorate. is there. On the other hand, when the molar ratio exceeds 20.0 / 1.0, the water resistance and heat resistance of the primer coating film tend to deteriorate.

  An organic monoisocyanate compound (a-2) can be used with an organic polyisocyanate compound (a-1). That is, a mixture of the organic polyisocyanate compound (a-1) and the organic monoisocyanate compound (a-2) can be used as the organic isocyanate compound (a).

  The organic monoisocyanate compound (a-2) is a compound having one isocyanate group in the compound, specifically, n-butyl monoisocyanate, n-hexyl monoisocyanate, n-hexadecyl monoisocyanate, Examples include n-octadecyl monoisocyanate, p-isopropylphenyl monoisocyanate, and p-benzyloxyphenyl monoisocyanate. Any of these may be used alone or in combination of two or more.

  The active hydrogen-containing compound (b) is a compound having one or more active hydrogens (groups) in the compound. In the present invention, the active hydrogen-containing compound (b) includes an active hydrogen-containing compound (b-1) having an anionic group, and further includes another active hydrogen-containing compound (b-2) as necessary.

  The active hydrogen-containing compound (b-1) having an anionic group is a compound having at least one anionic group and one or more active hydrogen (group) in the compound. By reacting the active hydrogen (group) of the active hydrogen-containing compound (b-1) having an anionic group with the isocyanate group of the organic isocyanate compound (a), an anionic group is introduced into the urethane prepolymer (U). The isocyanate group-containing urethane prepolymer (U) having an anionic group is easily emulsified and dispersed in water.

  Specific examples of the active hydrogen-containing compound (b-1) having an anionic group include an active hydrogen-containing compound having a carboxyl group and an active hydrogen-containing compound having a sulfone group. Any of these may be used alone or in combination of two or more.

  Specific examples of the active hydrogen-containing compound having a carboxyl group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolpentanoic acid, and 2,2-dimethylolhexane. Examples include acid, 2,2-dimethylolheptanoic acid, 2,2-dimethyloloctanoic acid, 2,2-dimethylolnonanoic acid, and 2,2-dimethyloldecanoic acid.

  Specific examples of the active hydrogen-containing compound having a sulfone group include dihydroxybutanesulfonic acid, dihydroxypropanesulfonic acid, N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonic acid, and N, N-bis. (2-hydroxyethyl) -2-aminobutanesulfonic acid, 1,3-phenylenediamine-4,6-disulfonic acid, diaminobutanesulfonic acid, diaminopropanesulfonic acid, 3,6-diamino-2-toluenesulfonic acid, 2,4-diamino-5-toluenesulfonic acid, N- (2-aminoethyl) -2-aminoethanesulfonic acid, 2-aminoethanesulfonic acid, N- (2-aminoethyl) -2-aminobutanesulfonic acid Is mentioned.

  Among these, 2,2-dimethylolpropion is versatile, since the isocyanate group-containing urethane prepolymer (U) having an anionic group is easily emulsified and dispersed in water, and the primer coating is excellent in water resistance. An acid, 2,2-dimethylolbutanoic acid is preferable, and 2,2-dimethylolpropionic acid is particularly preferable.

  In addition to the organic isocyanate compound (a) and the active hydrogen-containing compound (b-1) having an anionic group, the isocyanate group-containing urethane prepolymer (U) having an anionic group further contains other active hydrogen-containing compounds ( It can also be obtained by reacting b-2). In this case, the urethane prepolymer (U) is synthesized by reacting the organic isocyanate compound (a), the active hydrogen-containing compound (b-1) having an anionic group and the other active hydrogen-containing compound (b-2) in a lump. Or after reacting the organic isocyanate compound (a) with the other active hydrogen-containing compound (b-2), the active hydrogen-containing compound (b-1) having an anionic group is further charged and sequentially reacted. Alternatively, after reacting the organic isocyanate compound (a) with the active hydrogen-containing compound (b-1) having an anionic group, another active hydrogen-containing compound (b-2) is further charged and sequentially reacted. You may let them.

  In the present specification, the other active hydrogen-containing compound (b-2) is an active hydrogen-containing compound (b-1) having an anionic group, and an isocyanate group-containing urethane having an anionic group, which will be described in detail later. It is an active hydrogen-containing compound other than the chain extender (c) and the adhesion promoter (d) to be reacted with the prepolymer (U). In the present specification, other active hydrogen-containing compounds (b-2) are roughly classified into other low-molecular active hydrogen-containing compounds (b-2a) and other high-molecular active hydrogen-containing compounds (b-2b). . Any of these can be used alone or in combination.

  The other low-molecular active hydrogen-containing compound (b-2a) is an active hydrogen-containing compound having no anionic group having a number average molecular weight of less than 800. In addition, the number average molecular weight and weight average molecular weight in the present invention are molecular weights in terms of polystyrene measured by gel permeation chromatography (GPC).

  Specific examples of other low-molecular active hydrogen-containing compounds (b-2a) include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-deca Low molecular weight aliphatic polyols such as diol, diethylene glycol, triethylene glycol, dipropylene glycol and tripropylene glycol; Low molecular weight alicyclic polyols such as cyclohexanedimethanol and cyclohexanediol; Bisphenol A ethylene oxide (hereinafter referred to as “EO”) EO2 mol adduct of bisphenol A, EO4 mol adduct of bisphenol A, EO6 mol adduct of bisphenol A, EO8 mol adduct of bisphenol A, EO10 mol adduct of bisphenol A , Bisphenol A propylene oxide (hereinafter also referred to as “PO”) adducts, bisphenol A PO 2 mol adduct, bisphenol A PO 3 mol adduct and bisphenol A Low molecular weight aromatic polyols such as O5 mol adducts; 3 or more hydroxyl groups such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, polyglycerin, pentaerythritol, dipentaerythritol, tetramethylolpropane The low molecular polyol which has is mentioned. Any of these may be used alone or in combination of two or more. Among these, since the primer coating film is excellent in water resistance and heat resistance, a low-molecular aromatic polyol is preferable, and an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A are particularly preferable. Propylene oxide adducts are preferred.

  Other polymer active hydrogen-containing compounds (b-2b) are active hydrogen-containing compounds having no anionic group having a number average molecular weight of 800 or more. The number average molecular weight is preferably 800 to 30,000, more preferably 800 to 20,000, still more preferably 800 to 10,000, and 800 to 5,000. Particularly preferred. When the number average molecular weight exceeds 30,000, the reactivity when synthesizing the urethane prepolymer (U) decreases, and it takes time to synthesize the urethane prepolymer (U), or the urethane prepolymer (U). This increases the viscosity and may require a large amount of organic solvent, which increases the cost.

  Examples of other polymer active hydrogen-containing compounds (b-2b) include polymer polyols (polyols having a number average molecular weight of 800 or more).

  Specific examples of the polymer polyol include a polymer polyester polyol, a polymer polyether polyol, a polymer (meth) acryl polyol, a polymer polycarbonate polyol, a polymer polyolefin polyol, and a polymer animal and plant. Based polyols. Any of these polymer polyols can be used alone or in combination of two or more. In the present invention, “(meth) acryl” means “acryl and / or methacryl”.

  Among these, a high molecular weight polyester polyol, a high molecular weight polyether polyol, a high molecular weight (high molecular weight polyester polyol) in that the obtained urethane prepolymer (U) is easily emulsified in water and the primer composition is excellent in film-forming properties. A (meth) acrylic polyol and a high molecular weight polycarbonate polyol are preferable, and a high molecular weight (meth) acrylic polyol and a high molecular weight polycarbonate polyol are more preferable. A polymer (meth) acryl polyol is particularly preferable in that the primer composition is excellent in adhesiveness.

  Specific examples of the polymer polyester polyol include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, One or more of polycarboxylic acids such as naphthalenedicarboxylic acid and trimellitic acid, their acid esters or acid anhydrides, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol 1,9-nonanediol, diethylene glycol, dipropy Low molecular alcohols such as ethylene glycol, 1,4-cyclohexanedimethanol, ethylene oxide or propylene oxide adduct of bisphenol A, trimethylolpropane, glycerin, pentaerythritol, hexamethylenediamine, xylylenediamine, isophoronediamine, etc. Examples thereof include polyester polyols or polyester amide polyols obtained by a dehydration condensation reaction with one or more low molecular amino alcohols such as molecular amines, monoethanolamine, and diethanolamine. In addition, a lactone polyester polyol obtained by ring-opening polymerization of a cyclic ester (lactone) monomer such as ε-caprolactone or γ-valerolactone using a low molecular alcohol, a low molecular amine, or a low molecular amino alcohol as an initiator. Can be mentioned.

  As high molecular weight polyether polyols, ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, etc. using low molecular alcohols, low molecular amines, and low molecular amino alcohols used in the above-mentioned polyester polyol reaction as initiators. The polyether polyol obtained by making it contain is mentioned. Specific examples include polyoxyethylene polyols, polyoxypropylene polyols, polytetramethylene ether polyols, polyether polyols obtained by copolymerizing these, and polyester ether polyols using the above-described polyester polyol as an initiator. Of these, polyoxyethylene polyol and polyoxypropylene polyol are preferable.

  As the polymer (meth) acrylic polyol, a hydroxyl group-containing (meth) acrylic monomer and an ethylenically unsaturated compound other than this, in the presence or absence of a solvent, such as batch polymerization or continuous polymerization Examples thereof include those obtained by copolymerization by a radical polymerization method. Furthermore, what is obtained by continuous bulk copolymerization reaction at a high temperature of 150 to 350 ° C., more preferably 210 to 250 ° C. in the absence of a solvent, has a low odor, a narrow molecular weight distribution of the reaction product, and a low viscosity. Therefore, it is preferable. The number of hydroxyl groups in this polymer (meth) acryl polyol is preferably 2 or more on average in one molecule, more preferably more than 2, and particularly preferably 2.2 to 4. . When the number of hydroxyl groups in the polymer (meth) acrylic polyol is less than 2 on average in one molecule, the adhesion of the primer coating film may decrease.

  Moreover, the glass transition temperature (Tg) by differential scanning calorimetry (DSC) of the polymer (meth) acryl polyol is preferably 0 ° C. or less, more preferably −70 to −20 ° C., particularly preferably −70 to −−. 30 ° C. The number average molecular weight of the polymer (meth) acryl polyol is preferably 800 to 10,000, more preferably 800 to 5,000, and particularly preferably 800 to 3,000. The weight average molecular weight of the polymer (meth) acryl polyol is preferably 1,000 to 30,000, more preferably 1,000 to 10,000, and particularly preferably 1,000 to 5,000. The hydroxyl value of the polymer (meth) acryl polyol is preferably 10 to 200 mgKOH / g, particularly preferably 20 to 150 mgKOH / g. The hydroxyl value can be measured in accordance with JIS K1557-1 (2007) “How to determine the hydroxyl value”.

  The hydroxyl group-containing (meth) acrylic monomer is a (meth) acrylic monomer having at least one hydroxyl group in the molecule, specifically, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) Hydroxyalkyl (meth) acrylates such as acrylate and hydroxybutyl (meth) acrylate; pentaerythritol tri (meth) acrylate, glycerol mono (meth) acrylate, pentaerythritol di (meth) acrylate monostearate, dipentaerythritol penta (meth) ) Acrylate, ditrimethylolpropane tri (meth) acrylate, mono (meth) acrylates of polyhydric alcohols such as polypropylene glycol mono (meth) acrylate or hydroxyl group-remaining polyvalent (meth) acrylates. It is. Any of these may be used alone or in combination of two or more. Among them, the resulting polymer (meth) acrylic polyol has a low viscosity and good reactivity with an isocyanate group. (Meth) acrylates are preferred, and hydroxyethyl (meth) acrylate is more preferred.

  Examples of the ethylenically unsaturated compound other than the hydroxyl group-containing (meth) acrylic monomer include (meth) acrylic monomers that do not contain a hydroxyl group and ethylenically unsaturated compounds other than (meth) acrylic monomers. Examples of ethylenic compounds other than (meth) acrylic monomers include ethylene, propylene, isobutylene, butadiene, chloroprene, styrene, chlorostyrene, 2-methylstyrene, divinylbenzene, and other vinyl compounds, Examples of (meth) acrylic monomers that do not contain a hydroxyl group include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, ( 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, stearyl (meth) acrylate Cyclohexyl (meth) acrylate, tridecyl (meth) acrylate, ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,3-butanediol di (Meth) acrylate, 1,4-butanediol di (meth) acrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, Examples include polypropylene glycol di (meth) acrylate, glycidyl tri (meth) acrylate, and trimethylolpropane tri (meth) acrylate. Any of these may be used alone or in combination of two or more. Among these, a monomer of a (meth) acrylic acid ester compound is preferable in that the viscosity of the resulting polymer (meth) acrylic polyol is low, and methyl (meth) acrylate, ethyl (meth) acrylate, ( Preference is given to propyl (meth) acrylate, butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate.

  Specifically, as the high-molecular polycarbonate polyol, dehydrochlorination reaction of low molecular alcohols and phosgene used in the reaction of the polyester polyol described above, or the low molecular alcohols and diethylene carbonate, dimethyl carbonate, diethyl carbonate, Those obtained by transesterification with diphenyl carbonate and the like can be mentioned. Specific examples include polybutanediol carbonate, poly-3-methylpentanediol carbonate, polyhexanediol carbonate, polynonanediol carbonate, and polybutanediol hexanediol carbonate.

  Specific examples of the high-molecular polyolefin polyol include hydroxyl group-containing polybutadiene, hydrogenated hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisoprene, hydrogenated hydroxyl group-containing polyisoprene, hydroxyl group-containing chlorinated polypropylene, and hydroxyl group-containing chlorinated polyethylene. It is done.

  Specific examples of the high-molecular animal-and-vegetable polyol include castor oil-based polyol and silk fibroin.

  The mixing ratio of the other active hydrogen-containing compound (b-2) and the active hydrogen-containing compound (b-1) having an anionic group is the active hydrogen (group) (however, the active hydrogen (group) contained in the anionic group). Is a molar ratio (number of moles of other active hydrogen-containing compound (b-2) / number of moles of active hydrogen (group) of active hydrogen-containing compound (b-1) having an anionic group). 2 to 5.0 / 1.0 is preferable, 0.3 to 2.0 / 1.0 is more preferable, and 0.3 to 1.0 / 1.0 is particularly preferable.

  The anionic group content in the isocyanate group-containing urethane prepolymer (U) having an anionic group is preferably 0.3 to 6% by mass.

  Next, the step of neutralizing the anionic group of the isocyanate group-containing urethane prepolymer (U) having an anionic group using (II) a neutralizing agent will be described.

  In order to improve emulsification and dispersion of the isocyanate group-containing urethane prepolymer (U) having an anionic group in water, it is preferable to neutralize the anionic group in the urethane prepolymer (U) using a neutralizing agent. . By neutralizing the anionic group with a neutralizing agent, the anionic group becomes an anionic group salt, the affinity with water is improved, and the urethane prepolymer (U) is easily emulsified and dispersed in water.

  The neutralizing agent can be used before the urethane prepolymer (U) is emulsified and dispersed in water or simultaneously with the emulsification and dispersion in water. Furthermore, when synthesizing the urethane prepolymer (U), it may be used simultaneously with the operation of charging the active hydrogen-containing compound (b-1) having an anionic group. The urethane prepolymer (U) is preferably used before it is emulsified and dispersed in water because the urethane prepolymer (U) is easily emulsified and dispersed in water.

  Specific examples of the neutralizing agent include ammonia, ethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, and diethylethanol. Examples include organic amines such as amine, morpholine, N-methylmorpholine, 2-amino-2-ethyl-1-propanol, alkali metals such as lithium, potassium, and sodium, and inorganic alkalis such as sodium hydroxide and potassium hydroxide. . Any of these may be used alone or in combination of two or more. Of these, ammonia, trimethylamine, and triethylamine are highly volatile in order to improve the storage stability of the aqueous primer composition and to prevent the neutralizer from remaining in the primer coating as much as possible after the aqueous primer composition is dried and cured. And triethylamine is particularly preferable.

  The amount of neutralizing agent used is 0 in terms of molar ratio (molar number of neutralizing agent capable of forming salt with anionic group / molar number of anionic group) with respect to anionic group in urethane prepolymer (U). .6 to 1.1 / 1.0 is preferable, and 0.8 to 1.0 / 1.0 is more preferable. When the used amount of the neutralizing agent is less than 0.6 in the molar ratio, the urethane prepolymer (U) may be difficult to emulsify and disperse in water, or the storage stability of the aqueous primer composition may be reduced. . Moreover, when the usage-amount of a neutralizing agent exceeds 1.1 by the said molar ratio, especially when an organic amine is used as a neutralizing agent, the odor of an aqueous primer composition will become strong.

  (III) The process of emulsifying and dispersing the isocyanate group-containing urethane prepolymer (U) having an anionic group in water will be described.

  As a method of emulsifying and dispersing the isocyanate group-containing urethane prepolymer (U) having an anionic group in water, a method of emulsifying and dispersing water in a batch or sequentially by adding water to the urethane prepolymer (U) while stirring in a container. Alternatively, there is a method of emulsifying and dispersing the urethane prepolymer (U) in water all at once or while stirring in a container.

  The operation of emulsifying and dispersing the isocyanate group-containing urethane prepolymer (U) having an anionic group in water can be performed with a conventionally known stirrer. Homomixer, homogenizer, disper, line mixer, disperser using collision mixing, ultrasonic vibration to obtain uniform water dispersion with relatively easy adjustment of particle size of polyurethane resin (A) having anionic group Can be used.

  (IV) A polyurethane resin (A) having an anionic group by reacting an isocyanate group-containing urethane prepolymer (U) having an anionic group with at least one of a chain extender (c) and an adhesion-imparting agent (d). A process of synthesizing will be described. In addition, this process can also be performed simultaneously with the process of emulsifying and dispersing the (III) isocyanate group containing urethane prepolymer (U) which has an anionic group in water.

  At least one of a chain extender (c) and an adhesion-imparting agent (d) is added to the isocyanate group-containing urethane prepolymer (U) having an anionic group all at once or reacting with the isocyanate group of the urethane prepolymer (U). The polyurethane resin (A) having an anionic group is obtained by polymerizing the urethane prepolymer (U). The reaction temperature is preferably 0 to 60 ° C, more preferably 5 to 40 ° C, and particularly preferably 5 to 30 ° C.

  The chain extender (c) is a compound having active hydrogen (group) in the compound and reacts with the isocyanate group of the urethane prepolymer (U) (chain extension) to polymerize the urethane prepolymer (U). It is to make it. By forming the polyurethane prepolymer (U) into a polymer and forming a polyurethane resin (A) having an anionic group, the coating property of the aqueous primer composition is improved, and the primer coating is adhesive to the base material. The water resistance is particularly excellent.

  Specific examples of the chain extender (c) include ethylenediamine, 1,4-tetramethylenediamine, 2-methyl-1,5-pentanediamine, 1,4-butanediamine, 1,6-hexamethylenediamine, 1,4-hexamethylenediamine, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, 1,3-bis (aminomethyl) cyclohexane, xylylenediamine, piperazine, adipoylhydrazide, hydrazine (hydrate) ), Amine compounds such as 2,5-dimethylpiperazine, diethylenetriamine and triethylenetetramine, diol compounds such as ethylene glycol, propylene glycol, 1,4-butanediol and 1,6-hexanediol, and polyethylene glycol. Polyalkylene glycols, water It is below. Any of these may be used alone or in combination of two or more. In addition, when water is used as the chain extender, water as a dispersion medium also serves as the chain extender. Of these, primary diamines are preferred because of their excellent solubility in water and reactivity with the isocyanate groups of the urethane prepolymer (U), and hydrazine (including hydrates) and isophorone diamines are preferred. Including hydrates).

  The adhesion-imparting agent (d) is a compound having an active hydrogen (group) and a hydrolyzable (crosslinkable) silyl group reactive with the isocyanate group of the isocyanate group-containing urethane prepolymer (U) having an anionic group. is there. Hydrolyzable in polyurethane resin (A) having an anionic group by reacting an isocyanate group of urethane prepolymer (U) with a compound having an active hydrogen (group) reactive with an isocyanate group and a hydrolyzable silyl group. By introducing a silyl group, the primer coating becomes particularly excellent in adhesion to the base material and water resistance. That is, the hydrolyzable silyl group in the polyurethane resin (A) having an anionic group chemically reacts with the base material to improve adhesiveness, and the hydrolyzable silyl group is condensed with each other and has an anionic group. Resin (A) is polymerized to improve water resistance.

  The hydrolyzable silyl group is preferably one represented by the following general formula (1) from the viewpoint of adhesion of the primer coating to the base material and water resistance.

  In formula (1), R is a hydrocarbon group, preferably an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, and most preferably a methyl group. The reactive group represented by X is a group selected from a halogen atom, a hydrogen atom, a hydroxyl group, an alkoxy group, an acyloxy group, a ketoximate group, an amide group, an acid amide group, a mercapto group, an alkenyloxy group, and an aminooxy group. When X is plural, Xs may be the same group or different groups. Among these, X is preferably an alkoxy group, and most preferably a methoxy group or an ethoxy group. a is 0, 1 or 2, with 0 or 1 being most preferred.

  The silicon atom content of the hydrolyzable silyl group in the polyurethane resin (A) having an anionic group is preferably 0.01% by mass to 3.0% by mass, and more preferably 0.1% by mass to 3.0% by mass. % Is preferable, and 0.3% by mass to 2.0% by mass is particularly preferable. When the content of silicon atom of the hydrolyzable silyl group in the polyurethane resin (A) having an anionic group is less than 0.01% by mass, the adhesiveness to the base material (particularly inorganic material) may be lowered. Moreover, when content of the silicon atom of a hydrolyzable silyl group exceeds 3.0 mass%, the storage stability of an aqueous primer composition may worsen.

  Specific examples of the compound having an active hydrogen (group) and a hydrolyzable (crosslinkable) silyl group reactive with the isocyanate group of the isocyanate group-containing urethane prepolymer (U) having an anionic group include an aminosilane cup. Examples thereof include a ring agent and a mercaptosilane coupling agent. Any of these may be used alone or in combination of two or more.

  Specific examples of the aminosilane coupling agent include aminomethyltriethoxysilane, N- (2-aminoethyl) aminomethyltrimethoxysilane, aminomethyldiethoxysilane, and N- (2-aminoethyl) methyltributoxysilane. 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminoisobutyltrimethoxysilane, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, N- (2-amino) And ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) -3-amino-2-methylpropyltrimethoxysilane. It is done.

  Specific examples of the mercaptosilane coupling agent include 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyl. Examples include ethyldimethoxysilane, 3-mercaptopropylethyldiethoxysilane, 3-mercaptopropyldimethylmethoxysilane, 2-mercaptoethylmethyldimethoxysilane, 2-mercaptoethyltrimethoxysilane, and 2-mercaptoethyltriethoxysilane.

  Of these, aminosilane coupling agents are preferred because of their high reactivity with the isocyanate groups of the urethane prepolymer (U), and excellent adhesion and water resistance of the aqueous primer composition, and N- (2-aminoethyl) is also preferred. ) -3-Aminopropylmethyldimethoxysilane and 3-aminopropyltrimethoxysilane are preferred, and N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane is particularly preferred.

  The total amount of the chain extender (c) and the adhesion-imparting agent (d) used is the molar ratio of the isocyanate group-containing urethane prepolymer (U) having an anionic group to the isocyanate group (of the urethane prepolymer (U)). The number of moles of isocyanate group / the total number of moles of active hydrogen (group) of the chain extender (c) and the adhesion-imparting agent (d) is preferably 1.0 to 1.3 / 1.0, 1.0-1.2 / 1.0 is preferable, and 1.0-1.1 / 1.0 is particularly preferable.

  (V) The step of removing the organic solvent when the organic solvent is used in the steps (I) to (IV) described above will be described. When an organic solvent is used in the steps (I) to (IV), it is necessary to remove the organic solvent. If there is a large amount of organic solvent in the aqueous primer composition, it may cause odor, deterioration of the working environment and environmental pollution, and the storage stability of the aqueous primer composition will deteriorate.

  Examples of the method for removing the organic solvent include atmospheric distillation or vacuum distillation. You may heat in order to make it easy to distill an organic solvent in the case of distillation. When distilling off an organic solvent by warming atmospheric distillation or warming vacuum distillation, water may be distilled off at the same time as the organic solvent, so the heating temperature is appropriately set according to the type of organic solvent to be distilled off. There is a need to.

  The average particle size of the polyurethane resin (A) having an anionic group is preferably 10 to 1,000 nm, more preferably 20 to 500 nm, and particularly preferably 40 to 400 nm. When the average particle size of the polyurethane resin (A) having an anionic group is less than 10 nm, the drying property and water resistance of the aqueous primer composition deteriorate, and when the average particle size exceeds 1,000 nm, the aqueous primer composition is stored. Since stability deteriorates, it is not preferable. The average particle diameter in the present invention, such as the average particle diameter of the polyurethane resin (A) having an anionic group and the average particle diameter of the polyester-modified polyurethane resin (B), is a numerical value obtained by laser diffraction dispersion method particle size distribution measurement. is there.

Polyester-modified polyurethane resin (B)
The polyester-modified polyurethane resin (B) in the present invention is a component that improves the adhesion of the primer coating film in the aqueous primer composition of the present invention. In particular, the adhesiveness of the aqueous primer composition to aluminum or vinyl chloride is improved. The polyester-modified polyurethane resin (B) can be obtained by reacting, for example, polyester polyol, polyisocyanate and an active hydrogen compound that reacts with an isocyanate group. As a commercial item of a polyester modified polyurethane resin (B), Bihydrol UH-650 (made by Bayer MaterialScience) is mentioned. The polyester-modified polyurethane resin (B) is preferably a polyester-modified polyurethane resin aqueous dispersion dispersion).

  The average particle diameter of the polyester-modified polyurethane resin (B) is preferably 50 to 500 nm, more preferably 50 to 400 nm, and particularly preferably 50 to 300 nm.

The tensile strength of the polyester-modified polyurethane resin ^{(B) (N / mm 2} ) is preferably 15N / mm ² or less, 10 N / mm ² or less is particularly preferred. The elongation at break (%) of the polyester-modified polyurethane resin (B) is preferably 500% or more, more preferably 500 to 1,500%, and particularly preferably 800 to 1,200%. The tensile strength (N / mm ² ) and elongation at break (%) of the polyester-modified polyurethane resin (B) are determined according to JIS K 6251 “Tensile test method for vulcanized rubber (1993), dumbbell-shaped No. 4”. Can do.

  1-30 mass parts is preferable with respect to 100 mass parts of polyurethane resins (A) which have an anionic group, and, as for the usage-amount of a polyester modified polyurethane resin (B), 2-20 mass parts is especially preferable.

  In the aqueous primer composition of the present invention, in addition to the above components, additives can be used as long as the object of the present invention is not impaired. Specific examples of additives include adhesion promoters other than the adhesion promoter (d), antifoaming agents, leveling agents, colorants, antioxidants, ultraviolet absorbers, fillers, stabilizers, thickeners. Can be mentioned. Any of these additives may be used alone or in combination of two or more.

  Specific examples of the adhesion imparting agent other than the adhesion imparting agent (d) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3,4-epoxycyclohexylethyltrimethoxy. Epoxy silane coupling agents such as silane, 3,4-epoxycyclohexyltriethoxysilane, 3,4-epoxycyclohexylethylmethyldimethoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyl Unsaturated hydrocarbon silane coupling agents having a vinyl group or (meth) acryloyl group such as trimethoxysilane, vinylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and the like, and methyl silicate, methyltrimethoxysilane, ethyl Trimethoxysilane, butyltrimethoxysilane, octyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dibutyldimethoxysilane, diphenyldimethoxysilane, trimethylmethoxysilane, triethylmethoxysilane, triphenyl Examples thereof include hydrocarbon silane coupling agents such as methoxysilane and ureidosilane coupling agents such as 3-ureidopropyltriethoxysilane.

  Specific examples of antifoaming agents include mineral oil-based nonionic surfactants, polydimethylsiloxane oil, silicone-based antifoaming agents such as EO or PO-modified dimethylsilicone or dimethylsilicone emulsion, mineral oil, acetylene alcohol, etc. Alcohol-based antifoaming agent.

  As the colorant, a known colorant can be used as long as it is water-soluble and has visibility. Specific examples include Food Blue No. 1, Food Red No. 3, Food Red No. 102, Food Red No. 104, Food Red No. 105, Food Red No. 106, and Food Green No. 3. These are preferable because they give good coating visibility to the aqueous primer composition, and after the primer coating, they easily fade with ultraviolet rays such as sunlight and become colorless.

  In the aqueous primer composition of the present invention, the total amount of the polyurethane resin (A) having an anionic group, the polyester-modified polyurethane resin (B) and the additive (however, the component that becomes a primer coating after drying and curing) is an aqueous primer composition. It is preferable that it is 5 mass%-50 mass% of the whole thing, and it is especially preferable that it is 15 mass%-40 mass%. When the total amount of the polyurethane resin (A) having an anionic group, the polyester-modified polyurethane resin (B) and the additive is less than 5% by mass of the entire aqueous primer composition, there are many volatile components, so that the dry curing after the primer application. May be delayed, or the amount of resin (coating film component) to be applied may be reduced and a primer coating film may not be sufficiently secured. When the total amount of the polyurethane resin (A) having an anionic group, the polyester-modified polyurethane resin (B) and the additive exceeds 50% by mass of the entire aqueous primer composition, the storage stability of the primer is deteriorated, or the coating operation May be worse.

  The aqueous primer composition of the present invention is preferably used for architectural purposes and civil engineering purposes. The base material to which the aqueous primer composition of the present invention can be applied is not particularly limited, and specifically, wood materials such as solid wood, plywood and laminated wood, iron, copper, stainless steel, galvanium steel plate, Metal materials such as tin, aluminum, titanium, vinyl resin, acrylic resin, phenol resin, epoxy resin, polyester resin, synthetic resin material such as ABS (Acrylonitrile-Butadiene-Styrene copolymer), FRP (Fiber Reinforced Plastic), natural rubber, etc. Inorganic materials such as rubber material, tile, glass, brick, tile, mortar, concrete, slate, ALC (Autoclaved Lightweight Concrete), siding, porcelain, marble, granite and the like.

  Although there is no restriction | limiting in particular as an application | coating method of the aqueous | water-based primer composition of this invention, Specifically, there exists the method of apply | coating using a brush, a roller, a spray etc. to the adherend surface of a base material.

The coating amount of the aqueous primer composition of this invention, preferably from 10 to 400 g / ^{m 2,} more preferably 50 to 300 g / ^{m 2,} particularly 100 to 200 g / ^{m 2} is preferred. If the coating amount of the aqueous primer composition is less than 10 g / m ² , the primer coating (primer layer) may not be sufficiently formed and the adhesion may not be improved. On the other hand, when the coating amount of the aqueous primer composition exceeds 400 g / m ² , it is not preferable because the dry curability after the primer coating is deteriorated and the cost is increased.

  Further, there is no particular limitation on the sealing material, waterproofing material, and coating material that can be provided on the primer coating film (primer layer) formed from the aqueous primer composition of the present invention. A silicone-based sealing material can be mentioned.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further in detail, this invention is limited to these and is not interpreted.

[Synthesis Example 1]
In a reaction vessel equipped with a stirrer, thermometer, reflux condenser and nitrogen inlet tube, 96.1 g of dimethyl carbonate under a stream of nitrogen, acrylic polyol (ARUFON UH-2041, manufactured by Toagosei Co., Ltd., hydroxyl value 120 mgKOH / g-resin, glass 53.5 g of a transition temperature of −50 ° C., a number average molecular weight of 1,320, a weight average molecular weight of 2,260, a hydroxyl number calculated from a hydroxyl value and a number average molecular weight of 2.8 on average in one molecule, 5.0 g of oxypropylene triadduct of bisphenol A (BAP-3G, manufactured by Nippon Emulsifier Co., Ltd., hydroxyl value 280 mgKOH / g), 71.5 g of isophorone diisocyanate, isocyanurate modified form of hexamethylene diisocyanate (isocyanurate trimer) , Sumidur N3300, manufactured by Sumika Bayer Urethane Co., Ltd. The content of the carbonate group is 21.8%, the NCO equivalent 193) is 17.9 g, and 0.1 g of stannous octylate is charged as a reaction catalyst. After reacting until the isocyanate group content is 10.3% by mass or less, 18.0 g of 2,2-dimethylolpropionic acid and 12.9 g of triethylamine are added and further reacted to have an anionic group A containing urethane prepolymer solution (U-1) was obtained. The isocyanate group content of the isocyanate group-containing urethane prepolymer solution (U-1) having an anionic group was 5.0% by mass. Next, 546.8 g of water was added to emulsify and disperse the isocyanate group-containing urethane prepolymer having an anionic group, and then 253.8 g of water and N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane ( A mixed solution of 16.7 g of aminosilane coupling agent KBM-602 (manufactured by Shin-Etsu Silicone) and 3.8 g of hydrazine monohydrate was added to carry out a chain extension reaction at 30 ° C. Furthermore, in order to distill dimethyl carbonate out of the system, it was gradually heated to 50 ° C. under reduced pressure. After confirming that the distillation of dimethyl carbonate ceased, the reduced pressure was released while cooling to 30 ° C. or lower, and a composition containing 1% by mass of the anionic group-containing polyurethane resin (A-1) (theoretical resin component 19.8 mass) %). In addition, the average particle diameter of the polyurethane resin (A-1) which has an anionic group by the laser diffraction dispersion method particle size distribution measurement was 84 nm.

[Example 1]
100 g of a composition containing a polyurethane resin (A-1) having an anionic group obtained in Synthesis Example 1 under a nitrogen stream in a mixing vessel equipped with a stirrer and a nitrogen introduction tube, a polyester-modified polyurethane resin dispersion (Bihydrol UH-650) 2.0 g of non-volatile content, manufactured by Bayer MaterialScience Co., Ltd.) was stirred and mixed to obtain an aqueous primer composition (P-1). Bihydrol UH-650 has an average particle diameter of 101 nm as measured by a laser diffraction dispersion method particle size distribution measurement, and a tensile strength (N / mm ² ) measured according to JIS K 6251 (1993, dumbbell shape No. 4). 1N / mm ^2, elongation at break (%) was 1058%.

[Example 2]
An aqueous primer composition (P-2) was obtained in the same manner as in Example 1 except that the polyester-modified polyurethane resin dispersion (UH-650) was changed to 4.0 g.

[Comparative Example 1]
100 g of the composition containing the anionic group-containing polyurethane resin (A-1) obtained in Synthesis Example 1 was used as the aqueous primer composition (P-3).

[Comparative Example 2]
The same operation was carried out except that 2.8 g of a polycarbonate-modified urethane resin dispersion (bihydrol UH-2606, non-volatile content 35.0% by mass) was charged instead of the polyester-modified polyurethane resin dispersion (UH-650) in Example 1. An aqueous primer composition (P-4) was obtained. Bihydrol UH-2606 has an average particle size of 68 nm as measured by laser diffraction dispersion method particle size distribution measurement, and a tensile strength (N / mm ² ) measured according to JIS K 6251 (1993, dumbbell shape No. 4). It was 34 N / mm ² , and the elongation at break (%) was 269%.

[Comparative Example 3]
An aqueous primer composition (P-5) was obtained in the same manner as in Comparative Example 2 except that 5.6 g of polycarbonate-modified urethane resin dispersion (UH-2606) was charged.

[Comparative Example 4]
An aqueous primer was prepared in the same manner as in Example 1 except that 2.5 g of a polycarbonate-modified urethane resin dispersion (implanted DLC-F, nonvolatile content 40% by mass) was used instead of the polyester-modified polyurethane resin (UH-650). A composition (P-6) was obtained. In addition, Implanil DLC-F has an average particle size of 170 nm measured by laser diffraction dispersion method particle size distribution measurement, and a tensile strength (N / mm ² ) measured according to JIS K 6251 (1993, dumbbell shape No. 4). Was 40 N / mm ² , and the elongation at break (%) was 296%.

[Comparative Example 5]
An aqueous primer composition (P-7) was obtained in the same manner as in Comparative Example 4 except that 5.0 g of a polycarbonate-modified urethane resin dispersion (DLC-F) was charged.

[Evaluation method]
Evaluation shown below was performed using the aqueous primer composition obtained in Examples 1-2 and Comparative Examples 1-5.

<Adhesion test for slate, aluminum and PVC>
50mm x 50mm slate, 50mm x 50mm aluminum (aluminum sash), 50mm x 50mm rigid polyvinyl chloride (hard PVC), 50mm x 50mm soft polyvinyl chloride (soft PVC) Brush the aqueous primer compositions of Examples 1 and 2 and Comparative Examples 1 to 5 on the surface to be applied at a coating amount of 140 g / m ² and dry and cure at room temperature for 30 minutes to form a primer coating (primer layer). As a result, an adhesion test specimen was produced.

  Adhesion test specimens were tested in accordance with JIS K 5600-5-6 (1999) "Paint general test method, Part 5: Mechanical properties of coating film, Section 6: Adhesion (cross-cut method)" It was. Specifically, a single blade cutting tool was used to cut into the primer coating film of the adhesion test specimen, and 100 lattices having a size of 2 mm long × 2 mm wide were produced. Next, after adhering an adhesive tape to the surface of the lattice, the adhesive tape was peeled off, and the adhesiveness of the aqueous primer composition was evaluated according to the following criteria. The numerator value of the evaluation standard is the number of lattices to which the primer coating is attached, and the denominator value is the total number of lattices tested. The results are shown in the cross cut test column of Table 2.

Evaluation Criteria A: 100/100 × 100 (No lattice is peeled off)
○: 95 to 99/100 × 100 (1 to 5% of the entire lattice is peeled off)
Δ: 85-94 / 100 × 100 (6-15% of the entire lattice is peeled off)
×: 65 to 84/100 × 100 (16 to 35% of the entire lattice is peeled off)
Xx: 35-64 / 100x100 (36-65% of the whole lattice peels off)
XXX: 34 or less / 100 × 100 (34% or more of the entire lattice is peeled off)

<Adhesion test for sealing material (initial and after water immersion)>
50mm x 50mm slate, 50mm x 50mm aluminum (aluminum sash), 50mm x 50mm rigid polyvinyl chloride (hard PVC), 50mm x 50mm soft polyvinyl chloride (soft PVC) The aqueous primer compositions of Examples 1 and 2 and Comparative Examples 1 to 5 were brushed onto the adherend surface at a coating amount of 140 g / m ² and dried and cured at room temperature for 30 minutes to form a primer coating (primer layer). did. Next, a one-part moisture-curing urethane-based sealing material (Auton Siding Sealant, manufactured by Auto Chemical Industry Co., Ltd.) on the primer coating surface (applied surface) is approximately 20 mm wide × 10 mm high × 40 mm long bead shape (linear) And cured for 14 days under conditions of 23 ° C. and 50% RH (relative humidity) to obtain an initial adhesion test specimen. Pick one end of the bead-shaped cured product formed on the surface of this adhesion test specimen by hand, make a cut with a cutter knife between the one end of the cured product and the primer coating, and turn it back 180 ° in the length direction. Tensile and adhesive properties were confirmed. Table 2 shows the results of evaluation based on the following criteria. The parentheses in Table 2 indicate the fracture state caused by tension, CF is the cohesive failure of the sealing material, TCF is the thin layer cohesive failure of the sealing material, and PF is the primer coating film and the adherend (slate). , Aluminum sash, hard PVC, soft PVC), and AF is interface peeling between the sealing material and the primer coating. The cohesive failure of the sealing material is a phenomenon in which the sealing material eventually breaks when the tensile force is increased because the adhesion between the sealing material and the primer coating film and between the primer coating film and the adherend is good. Also, interfacial peeling between the primer coating and the adherend is a phenomenon that occurs when the adhesive strength between the primer coating and the adherend is weaker than the fracture strength of the sealing material and the adhesive strength between the sealing material and the primer coating. Yes, interface peeling between the sealing material and the primer coating is a phenomenon that occurs when the adhesive strength between the sealing material and the primer coating is weaker than the breaking strength of the sealing material and the adhesion strength between the primer coating and the adherend. .

Evaluation criteria ○: It does not peel off even when it is strongly pulled, and it causes cohesive failure of the sealing material. Δ: It peels off when it is pulled strongly, and it is peeled off at the interface.

  Similarly, after preparing an initial adhesion test body, the adhesion test body was immersed in water at 23 ° C. for 7 days. After immersion in water, the test specimen was taken out and gently wiped with a waste cloth, which was used as an adhesion test specimen after immersion in water. Pick up one end of the bead-like cured product formed on the surface of the adhesion test specimen after immersion in water by hand, and cut it with a cutter knife between the one end of the cured product and the primer coating. The adhesiveness was confirmed according to the same evaluation criteria as above. The results are shown in Table 2.

  As shown in Table 2, the water-based primer composition of the present invention has high water resistance, and is excellent in adhesion to a base material such as slate, aluminum, and vinyl, and a sealing material, and has a sealing material, a waterproof material, and a coating material. It can be used as a primer (for base treatment) when constructing. In particular, it is suitable as a urethane-based or modified silicone-based sealing material, waterproof material, and coating material.

Claims (11)

  An aqueous primer composition comprising a polyurethane resin (A) having an anionic group and a polyester-modified polyurethane resin (B).   The polyurethane resin (A) having an anionic group is obtained by reacting an organic isocyanate compound (a) with an active hydrogen-containing compound (b) including an active hydrogen-containing compound (b-1) having an anionic group. The aqueous primer composition according to claim 1, wherein   The polyurethane resin (A) having the anionic group reacts the organic isocyanate compound (a) with the active hydrogen-containing compound (b) including the active hydrogen-containing compound (b-1) having the anionic group. It is obtained by synthesizing an isocyanate group-containing urethane prepolymer (U) having an anionic group, and further by reacting at least one of a chain extender (c) and an adhesion-imparting agent (d). Item 3. The aqueous primer composition according to Item 2.   The organic isocyanate compound (a) is a modified organic polyisocyanate (a-1b) or a mixture of an organic polyisocyanate (a-1a) and a modified organic polyisocyanate (a-1b). The aqueous primer composition according to 2 or 3.   The aqueous primer composition according to claim 4, wherein the modified organic polyisocyanate (a-1b) is an isocyanurate-modified organic polyisocyanate.   The said active hydrogen containing compound (b) contains the active hydrogen containing compound (b-1) which has the said anionic group, and a high molecular weight polyol, As described in any one of Claims 2-5 characterized by the above-mentioned. Aqueous primer composition.   The active hydrogen-containing compound (b) contains the active hydrogen-containing compound (b-1) having the anionic group and a polymer (meth) acrylic polyol. The aqueous primer composition according to Item. The aqueous primer composition according to claim 1, wherein the polyester-modified polyurethane resin (B) has a tensile strength (N / mm ² ) of 15 N / mm ² or less.   The aqueous primer composition according to any one of claims 1 to 8, wherein the polyester-modified polyurethane resin (B) has an elongation at break (%) of 500% or more.   The aqueous primer composition according to any one of claims 1 to 9, wherein the polyester-modified polyurethane resin (B) has an average particle size of 50 to 500 nm.   The aqueous primer composition according to any one of claims 1 to 10, which is an aqueous primer composition for construction or civil engineering.