Aqueous primer composition

Abstract

To provide an aqueous primer composition which has excellent adhesion to an adherend such as aluminum, and can improve adhesion to a porous member and adhesion to an existing sealing material.SOLUTION: An aqueous primer composition containing an organic polymer dispersed in an aqueous medium contains (A) an anionic urethane resin emulsion, and (B) a silyl group-containing acrylic resin emulsion. The aqueous primer composition is suitably usable as a sealing material.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an aqueous primer composition. [Background technology]

[0002] In order to adhere a construction sealant to an adherend such as aluminum or mortar, a primer is generally applied to the adherend beforehand, and then the sealant is applied. By applying a primer, the adhesive strength between the adherend and the sealant is improved. Such primers often contain organic solvents. If a primer containing an organic solvent is used at a construction site, problems such as the odor of the organic solvent of the primer, the flammability of the organic solvent, and the safety of workers may occur. Therefore, there is a demand for the development of a primer that does not contain organic solvents. Patent Documents 1 and 2 have been reported as such water-based primers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-231274 A [Patent Document 2] JP 2015-212346 A Summary of the Invention [Problem to be solved by the invention]

[0004] The problem with water-based primers is that they have poor permeability into the adherend and poor adhesion between the adherend and the sealant. Patent Documents 1 and 2 all address these issues, but further improvements are needed. Furthermore, there is a need for improved adhesion to porous members and to existing sealants with regard to water-based primers. [Means for solving the problem]

[0005] As a result of extensive research, the present inventors have discovered that an aqueous primer composition comprising (A) an anionic urethane resin emulsion and (B) a silyl group-containing acrylic resin emulsion has excellent adhesion to adherends such as aluminum, and is capable of improving adhesion to porous members and adhesion to existing sealants, thereby completing the present invention.

[0006] This specification includes the following embodiments. 1. An aqueous primer composition comprising an organic polymer dispersed in an aqueous medium, (A) an anionic urethane resin emulsion, and (B) Silyl group-containing acrylic resin emulsion 1. An aqueous primer composition comprising: 2. The aqueous primer composition according to 1 above, wherein the (A) anionic urethane resin emulsion contains (A1) an anionic urethane resin emulsion having a polyoxyalkylene skeleton. 3. The aqueous primer composition according to 1 or 2 above, wherein the (A) anionic urethane resin emulsion contains (A2) an anionic urethane resin emulsion having a polyester and / or polycarbonate skeleton. 4. An aqueous primer composition for a sealant according to any one of 1 to 3 above, which is used between a sealant and an adherend. 5. The aqueous solution according to any one of 1 to 4 above. Applying the primer composition to an adherend to form a primer layer; and Apply a sealant over the primer layer. A method for applying a sealant, comprising: Effect of the Invention

[0007] The aqueous primer composition according to the embodiment of the present invention contains (A) an anionic urethane resin emulsion and (B) a silyl group-containing acrylic resin emulsion, and has excellent adhesion to adherends such as aluminum, and can improve adhesion to porous members and adhesion to existing sealants. Therefore, the aqueous primer composition according to the embodiment of the present invention can be suitably used for architectural adherends. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 shows a schematic diagram of a test specimen for evaluating the simple adhesion of an aqueous primer composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In one aspect, the present invention discloses an aqueous primer composition comprising an organic polymer dispersed in an aqueous medium, the aqueous primer composition comprising: (A) an anionic urethane resin emulsion, and (B) Silyl group-containing acrylic resin emulsion Includes.

[0010] The aqueous primer composition of the present embodiment comprises an organic polymer dispersed in an aqueous medium. The aqueous medium is not particularly limited as long as the aqueous primer composition targeted by the present invention can be obtained, but includes, for example, so-called water such as ion-exchanged water, distilled water, and tap water, as well as a dispersion medium or solvent that is miscible with water. The organic polymer includes (A) anionic urethane resin and (B) silyl group-containing acrylic resin, and may include other organic polymers as long as the aqueous primer composition targeted by the present invention can be obtained. The organic polymer is dispersed in an aqueous medium, and may be in a liquid phase, a solid phase, or a combination of a liquid phase and a solid phase. Therefore, the aqueous primer composition of the embodiment of the present invention includes both the concepts of "emulsion" and "suspension."

[0011] In this specification, (A) anionic urethane resin (also referred to as (A) urethane resin) is a polymer having a urethane bond (-NH-COO-), and is generally obtained by polyaddition of a compound having an isocyanate group and a compound having a hydroxyl group, and is a resin containing a polymer having an anionic group. There are no particular limitations on this term as long as the aqueous primer composition intended by the present invention can be obtained.

[0012] The anionic group of the urethane resin (A) is not particularly limited as long as the aqueous primer composition of the present invention can be obtained. For example, a carboxylate group (-COO - ), sulfonate group (-SO3 - ), sulfate group (-O-SO3 - ), phosphate group (-O-PO3 2- ), phosphoryl group (-PO3 2- ) and the like. A carboxylate group (-COO - ), sulfonate group (-SO3 - ) etc. are preferred.

[0013] The (A) anionic urethane resin emulsion preferably contains (A1) an anionic urethane resin emulsion having a polyoxyalkylene skeleton. When the anionic urethane resin emulsion (A) contains the anionic urethane resin emulsion (A1) having a polyoxyalkylene skeleton, it can exhibit the advantageous effect of improving the wettability to a two-component polyurethane sealant.

[0014] (A) Anionic urethane resin emulsion preferably contains (A2) anionic urethane resin emulsion having a polyester and / or polycarbonate skeleton. When the anionic urethane resin emulsion (A) contains the anionic urethane resin emulsion (A2) having a polyester and / or polycarbonate skeleton, it can exhibit the advantageous effect of improving joint adhesion.

[0015] The method for producing the anionic urethane resin emulsion (A) is not particularly limited, but the following production methods can be exemplified. For example, reacting a polyisocyanate, a polyol, and a compound having two or more hydroxy groups and at least one anionic group (or its corresponding acid group) to produce an isocyanate terminated urethane prepolymer having an anionic group (or its corresponding acid group); If necessary, neutralizing the urethane prepolymer with a neutralizing agent; Dispersing a urethane prepolymer in an aqueous medium; and reacting the urethane prepolymer with a chain extender to polymerize it, thereby producing an anionic urethane resin emulsion; Examples of the production method include the following:

[0016] In this specification, the above-mentioned polyisocyanate is a compound having two or more isocyanate groups in the compound, and is not particularly limited as long as the aqueous primer composition of the present invention can be obtained. Examples of polyisocyanates include aromatic polyisocyanates, aliphatic polyisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates. Examples of aromatic polyisocyanates include toluene polyisocyanates such as 2,4-toluene diisocyanate and 2,6-toluene diisocyanate; diphenylmethane polyisocyanates such as 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and 2,2'-diphenylmethane diisocyanate; 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and 2,4,6-trimethylphenyl-1,3-diisocyanate. phenylene polyisocyanates such as 2,4,6-triisopropylphenyl-1,3-diisocyanate; naphthalene polyisocyanates such as 1,4-naphthalene diisocyanate and 1,5-naphthalene diisocyanate; and other aromatic polyisocyanates such as chlorophenylene-2,4-diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, and 3,3'-dimethoxydiphenyl-4,4'-diisocyanate. Further examples include aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, decamethylene diisocyanate, and lysine diisocyanate; aromatic aliphatic polyisocyanates such as o-xylylene diisocyanate, m-xylylene diisocyanate, and p-xylylene diisocyanate; and alicyclic polyisocyanates such as 1,4-cyclohexyl diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. These can be used alone or in combination of two or more. Aliphatic polyisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates are preferred.

[0017] The above-mentioned polyisocyanate may include modified polyisocyanate. The modified polyisocyanate may be obtained by modifying at least one polyisocyanate. Specific examples of modified polyisocyanate include modified polyisocyanates having one or more of uretdione bonds, isocyanurate bonds, allophanate bonds, biuret bonds, uretonimine bonds, carbodiimide bonds, urethane bonds, and urea bonds in the compound. These may be used alone or in combination of two or more.

[0018] The above-mentioned compound having two or more hydroxy groups and at least one anionic group (or the corresponding acid group) is a compound having two or more hydroxy groups and an anionic group (or the corresponding acid group), and is not particularly limited as long as the aqueous primer composition targeted by the present invention can be obtained. Examples of compounds having two or more hydroxy groups and at least one anionic group (or the corresponding acid group) include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and the like.

[0019] The neutralizing agent is not particularly limited as long as it can neutralize the acid and can obtain the aqueous primer composition of the present invention. As the neutralizing agent, it is preferable to use a base such as ammonia, trimethylamine, triethylamine, 2-(dimethylaminomethyl)phenol, etc. These bases may be carried into the aqueous primer composition of the present invention while being contained in the urethane resin emulsion (A). Since these bases are volatile, even if they remain in the primer layer obtained by curing the aqueous primer composition of the embodiment of the present invention, only a trace amount is considered to remain, and it is unlikely that they will have a particularly adverse effect.

[0020] The above-mentioned polyol refers to a compound having two or more hydroxyl groups, excluding the above-mentioned compounds having two or more hydroxyl groups and at least one anionic group (or the corresponding acid group), and is not particularly limited as long as the aqueous primer composition targeted by the present invention can be obtained. aliphatic polyols such as 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-decanediol, diethylene glycol, triethylene glycol, dipropylene glycol and tripropylene glycol; Alicyclic polyols such as cyclohexanedimethanol and cyclohexanediol; Polyols having three or more hydroxyl groups, such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, polyglycerin, pentaerythritol, dipentaerythritol, and tetramethylolpropane. Examples include: These can be used alone or in combination of two or more.

[0021] The above-mentioned polyols can include polyester polyols, polyether polyols, (meth)acrylic polyols, polycarbonate polyols, and the like. When the polyol contains a polyether polyol, it is possible to obtain an anionic urethane resin emulsion (A1) having a polyoxyalkylene skeleton. When the above-mentioned polyol contains a polyester polyol and / or a polycarbonate polyol, it is possible to obtain (A2) an anionic urethane resin emulsion having a polyester and / or polycarbonate skeleton.

[0022] In this specification, polyether polyol refers to a compound having a polyoxyalkylene skeleton and having two or more hydroxyl groups, and is not particularly limited as long as the aqueous primer composition aimed at by the present invention can be obtained. Examples of polyether polyols include polyether polyols obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, etc., using the above-mentioned polyols, amines, amino alcohols, etc. as initiators. Specific examples include polyoxyethylene polyols, polyoxypropylene polyols, polytetramethylene ether polyols, and polyether polyols copolymerized with these. Further examples of polyether polyols include polyether polyols that use an aromatic polyol as an initiator, such as ethylene oxide (hereinafter sometimes referred to as "EO") adducts of bisphenol A, which are an EO adduct of bisphenol A with 2 moles of EO, an EO adduct of bisphenol A with 4 moles of EO, an EO adduct of bisphenol A with 6 moles of EO, an EO adduct of bisphenol A with 8 moles of EO, an EO adduct of bisphenol A with 10 moles of EO, and propylene oxide (hereinafter sometimes referred to as "PO") adducts of bisphenol A, which are a PO adduct of bisphenol A with 2 moles of PO, an PO adduct of bisphenol A with 3 moles of PO, and an PO adduct of bisphenol A with 5 moles of PO.

[0023] In this specification, polyester polyol refers to a compound having a polyester skeleton and two or more hydroxyl groups, and is not particularly limited as long as the aqueous primer composition aimed at by the present invention can be obtained. Specific examples of polyester polyols include polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, and trimellitic acid, and acid esters or acid anhydrides thereof, and a mixture of these with ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, or the like. Examples of the polyester polyols include those obtained by dehydration condensation reaction with one or more alcohols such as diol, 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, 1,4-cyclohexanedimethanol, trimethylolpropane, glycerin, pentaerythritol, etc. Also, examples of the lactone-based polyester polyols include those obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using alcohol as an initiator.

[0024] In this specification, (meth)acrylic polyol refers to a compound having a skeleton based on an acrylic resin and having two or more hydroxyl groups, and is not particularly limited as long as the aqueous primer composition of the present invention can be obtained. For example, an example of the (meth)acrylic polyol is a (meth)acrylic polyol obtained by copolymerizing a hydroxyl group-containing (meth)acrylic monomer and another ethylenically unsaturated compound by a radical polymerization method such as batch or continuous polymerization in the presence or absence of a solvent.

[0025] In this specification, polycarbonate polyol refers to a compound having a polycarbonate skeleton and having two or more hydroxyl groups, and is not particularly limited as long as the aqueous primer composition targeted by the present invention can be obtained. Polycarbonate polyol can be synthesized, for example, from an alkanediol and a carbonic acid diester as raw materials in the presence of an ester exchange catalyst.

[0026] The urethane resin (A) may be dispersed in an aqueous medium, and the particle size is preferably 30 to 200 nm, and more preferably 40 to 200 nm. When the particle size of the urethane resin (A) is 30 to 200 nm, the permeability, wettability, and affinity to the adherend tend to be good, and the adhesiveness tends to be improved. The particle size of the urethane resin (A) can be measured at 25° C. using a concentrated particle size analyzer "FPAR-1000" (analyzer manufactured by Otsuka Electronics Co., Ltd.).

[0027] The Tg (glass transition temperature) of the (A) urethane resin is, for example, −60 to 80° C., preferably −40 to 60° C., more preferably −20 to 50° C., and further preferably −10 to 40° C. When the (A) urethane resin has a Tg of −60 to 80° C., the adhesiveness is superior. The Tg of the urethane resin (A) can be measured by a dynamic viscoelasticity test using a "Reogel E4000" (a dynamic viscoelasticity measuring device manufactured by UBM Corporation) under the conditions of a measurement start temperature of 10°C, a measurement end temperature of 170°C, a heating rate of 4°C / min, a step temperature of 1°C, and a frequency of 1 Hz.

[0028] The MFT (Minimum Film-forming Temperature) of the (A) urethane resin is, for example, 0 to 60° C., preferably 0 to 40° C., more preferably 0 to 20° C., and even more preferably 0 to 5° C. When the MFT of the (A) urethane resin is 0 to 60° C., the film-forming property at low temperatures (assuming winter) is superior. The MFT of the urethane resin (A) can be measured using a minimum film-forming thermometer (manufactured by Rhopoint Instruments: MFFTB90).

[0029] The aqueous primer composition of the present embodiment may contain, for example, 10 to 90 parts by mass of the urethane resin (A) per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium), preferably contains 20 to 70 parts by mass of the urethane resin (A), more preferably contains 25 to 65 parts by mass of the urethane resin (A), and even more preferably contains 35 to 65 parts by mass of the urethane resin (A). The aqueous primer composition of the embodiment of the present invention has superior adhesion to porous members when it contains 10 to 90 parts by mass of the urethane resin (A) per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium).

[0030] As the (A) urethane resin emulsion, commercially available products can be used. Examples of such commercially available products include WBR-016U (trade name) manufactured by Taisei Fine Chemical Co., Ltd., WBR-2101 (trade name) manufactured by Taisei Fine Chemical Co., Ltd., HYDRAN HW-311 (trade name) manufactured by DIC Corporation, and TAKELAC W-512A6, TAKELAC W-6021, and TAKELAC W-6061 manufactured by Mitsui Chemicals MC, Inc.

[0031] In this specification, the (B) silyl group-containing acrylic resin refers to an acrylic resin obtained by polymerizing at least one selected from acrylic acid esters and methacrylic acid esters, which is an acrylic resin having a silyl group, and is not particularly limited as long as the aqueous primer composition intended by the present invention can be obtained. In this specification, acrylic acid and methacrylic acid are also collectively referred to as (meth)acrylic acid, and acrylic acid esters and methacrylic acid esters are also collectively referred to as (meth)acrylic acid esters or (meth)acrylates.

[0032] The acrylic acid ester and the methacrylic acid ester are not particularly limited as long as the aqueous primer composition targeted by the present invention can be obtained. For example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl Examples of the acrylate include alkyl (meth)acrylates such as (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, isomyristyl (meth)acrylate, n-tridecyl (meth)acrylate, and n-tetradecyl (meth)acrylate; and cycloalkyl (meth)acrylates such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, and cyclooctyl (meth)acrylate.

[0033] In this specification, the term "silyl group" refers to a reactive silyl group that, in the presence of water, is hydrolyzed to produce a silanol group and that can further react with itself to produce a siloxane bond. There are no particular limitations on the type of silyl group as long as the aqueous primer composition intended by the present invention can be obtained.

[0034] Examples of reactive silyl groups include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, tripropoxysilyl group, triisopropoxysilyl group, tributoxysilyl group, triisobutoxysilyl group, tri-s-butoxysilyl group, and tri-t-butoxysilyl group; alkyldialkoxysilyl groups such as methyldimethoxysilyl group, methyldiethoxysilyl group, methyldipropoxysilyl group, methyldibutoxysilyl group, ethyldimethoxysilyl group, ethyldiethoxysilyl group, ethyldipropoxysilyl group, ethyldibutoxysilyl group, propyldimethoxysilyl group, propyldiethoxysilyl group, propyldipropoxysilyl group, and propyldibutoxysilyl group; and dialkyl(mono)alkoxysilyl groups corresponding to these groups. Preferred are a triethoxysilyl group, a tripropoxysilyl group, a diethoxysilyl group (such as a methyldiethoxysilyl group or an ethyldiethoxysilyl group), or a dipropoxysilyl group (such as a methyldipropoxysilyl group or an ethyldipropoxysilyl group).

[0035] The method for introducing the reactive silyl group into the (B) silyl group-containing acrylic resin is not particularly limited as long as the aqueous primer composition of the present invention can be obtained. For example, a method of copolymerizing a monomer having a reactive silyl group with at least one selected from the above acrylic acid esters and methacrylic acid esters can be exemplified as such a method. Examples of monomers having a reactive silyl group include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrippropoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinylmethyldipropoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropyltrippropoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-acryloxypropylmethyldiethoxysilane, γ-acryloxypropylmethyldipropoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltrippropoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropylmethyldipropoxysilane, and the like. These can be used alone or in combination.

[0036] The silyl group-containing acrylic resin (B) may contain monomers polymerized therein other than the above-mentioned monomers, so long as the aqueous primer composition targeted by the present invention can be obtained. Examples of such monomers include the following monomers. α-olefins such as ethylene, propylene, and isobutylene; α,β-unsaturated mono- or dicarboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid; Amides of α,β-unsaturated mono- or dicarboxylic acids, such as acrylamide, methacrylamide, etc.; N-Methylolated amides; Ethylene glycol esters; Dialkyl esters such as dialkyl maleate, dialkyl fumarate, and dialkyl itaconate; Vinyl esters such as vinyl acetate, vinyl propionate, and vinyl versatate; Aromatic vinyl compounds such as styrene and vinyl toluene; Vinyl halides such as vinyl chloride and vinylidene chloride; Vinyl ethers such as methyl vinyl ether; Dienes such as butadiene

[0037] (B) silyl group-containing acrylic resin may be dispersed in an aqueous medium, and its particle size is, for example, 10 to 900 nm, preferably 10 to 500 nm, more preferably 15 to 450 nm, even more preferably 17 to 400 nm, and even more preferably 20 to 300 nm. When the particle size of (B) silyl group-containing acrylic resin is 10 to 900 nm, there is a tendency for the permeability, wettability, and affinity to the adherend to be good, and there is a tendency for the adhesiveness to be improved. The particle size of the copolymer (A) can be measured at 25° C. using a concentrated particle size analyzer "FPAR-1000" (analyzer manufactured by Otsuka Electronics Co., Ltd.).

[0038] The Tg (glass transition temperature) of the (B) silyl group-containing acrylic resin is, for example, −50 to 100° C., preferably −20 to 80° C., more preferably −10 to 60° C., and further preferably 0 to 45° C. When the (B) silyl group-containing acrylic resin has a Tg of −50 to 100° C., the adhesiveness is superior. The Tg of the silyl group-containing acrylic resin (B) can be measured by a dynamic viscoelasticity test using a "Reogel E4000" (a dynamic viscoelasticity measuring device manufactured by UBM Co., Ltd.) under the conditions of a measurement start temperature of 10°C, a measurement end temperature of 170°C, a heating rate of 4°C / min, a step temperature of 1°C, and a frequency of 1 Hz.

[0039] The MFT (Minimum Film-forming Temperature) of (B) the silyl group-containing acrylic resin is, for example, 0 to 50° C., preferably 0 to 40° C., more preferably 0 to 25° C., and even more preferably 0 to 20° C. When the MFT of (B) the silyl group-containing acrylic resin is 0 to 50° C., the workability is superior. The MFT of the (B) silyl group-containing acrylic resin can be measured by a minimum film-forming thermometer (manufactured by Rhopoint Instruments: MFFTB90).

[0040] The aqueous primer composition of the present embodiment may contain, for example, 10 to 90 parts by mass of the (B) silyl group-containing acrylic resin per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium), preferably contains 10 to 80 parts by mass of the (B) silyl group-containing acrylic resin, more preferably contains 10 to 60 parts by mass of the (B) silyl group-containing acrylic resin, and even more preferably contains 10 to 40 parts by mass of the (B) silyl group-containing acrylic resin. The aqueous primer composition according to an embodiment of the present invention has superior adhesion to porous members when it contains 10 to 90 parts by mass of the silyl group-containing acrylic resin (B) per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium).

[0041] As the (B) silyl group-containing acrylic resin, commercially available products can be used, such as W3153CF (product name) manufactured by Kaneka Corporation and KD-6 (product name) manufactured by Henkel Japan Co., Ltd.

[0042] The ratio ((A) / (B)) (mass ratio) of the urethane resin (A) to the silyl group-containing acrylic resin (B) is not particularly limited as long as the aqueous primer composition targeted by the present invention can be obtained, but is, for example, 90 / 10 to 10 / 90, preferably 85 / 15 to 20 / 80, more preferably 85 / 15 to 30 / 70, and even more preferably 85 / 15 to 40 / 60. When the ratio ((A) / (B)) (mass ratio) of the urethane resin (A) to the silyl group-containing acrylic resin (B) is 90 / 10 to 10 / 90, excellent joint adhesion is achieved.

[0043] The aqueous primer composition of the present invention may further include a titanium coupling agent. In this specification, the titanium coupling agent is a compound containing Ti, which has both a site that reacts with an organic compound and a site that reacts with an inorganic compound, and is not particularly limited as long as the aqueous primer composition of the present invention can be obtained. Examples of titanium coupling agents include titanium coupling agents having an amino group, titanium coupling agents having a hydroxycarboxylic acid group, titanium coupling agents having a hydroxyl group, titanium coupling agents having an acetylacetonato group, etc. It is preferable to include at least one selected from titanium coupling agents having an amino group and titanium coupling agents having a hydroxyl group. The titanium coupling agent preferably contains an alkoxy group.

[0044] The aqueous primer composition of the present invention preferably contains 0.1 to 5 parts by mass of a titanium coupling agent, more preferably contains 0.5 to 3 parts by mass of a titanium coupling agent, and even more preferably contains 0.8 to 2 parts by mass of a titanium coupling agent, per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium). The aqueous primer composition of the embodiment of the present invention contains 0.1 to 5 parts by mass of a titanium coupling agent per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium), and when it contains at least one selected from a titanium coupling agent having an amino group and a titanium coupling agent having a hydroxyl group, it can provide the advantageous effect of providing better adhesion to an adherend (particularly an inorganic material).

[0045] The aqueous primer composition of the embodiment of the present invention may contain, for example, 50 to 90 parts by mass of the aqueous medium per 100 parts by mass of the aqueous primer composition (including the aqueous medium), preferably contains 60 to 85 parts by mass of the aqueous medium, and more preferably contains 60 to 80 parts by mass of the aqueous medium. The aqueous primer composition of the embodiment of the present invention can exhibit the advantageous effect of being more excellent in workability when it contains 50 to 90 parts by mass of the aqueous medium per 100 parts by mass of the aqueous primer composition (including the aqueous medium).

[0046] In addition to the above-mentioned components, the aqueous primer composition of the present invention may further contain additives as necessary, as long as the aqueous primer composition of the present invention can be obtained.As additives, for example, fillers, pigments, antiblocking agents, dispersion stabilizers, thixotropic agents, viscosity regulators, leveling agents, gelling inhibitors, light stabilizers, antiaging agents, antioxidants, UV absorbers, plasticizers, lubricants, antistatic agents, reinforcing materials, flame retardants, catalysts, defoamers, thickeners, dispersants, surfactants, silane coupling agents, film-forming assistants, etc. can be exemplified.As long as the aqueous primer composition of the present invention can be obtained, the amount of these additives can be appropriately selected and is not particularly limited.

[0047] The method for producing the aqueous primer composition of the embodiment of the present invention is not particularly limited as long as the aqueous primer composition of the present invention can be obtained. For example, a method for producing the aqueous primer composition by mixing the above-mentioned components can be exemplified.

[0048] The aqueous primer composition of the embodiment of the present invention can be applied to various adherends. As long as it can be applied, the adherend is not particularly limited. Examples of the adherend to which the aqueous primer composition of the embodiment of the present invention can be applied include glass; metals such as aluminum, anodized aluminum, iron, galvanized steel sheet, copper, and stainless steel; porous members such as mortar and stone; members coated with fluorine electrodeposition, acrylic electrodeposition, fluorine coating, urethane coating, and acrylic urethane coating; hardened sealants such as silicone, modified silicone, urethane, polysulfide, and polyisobutylene; vinyl chloride resin, acrylic resin; rubbers such as NBR and EPDM; and the like.

[0049] The aqueous primer composition of the present invention can be applied to such an adherend to form a primer layer, and a sealant can be applied over the primer layer. Therefore, the aqueous primer composition of the embodiment of the present invention can be used between a sealant and an adherend, and can be suitably used as an aqueous primer composition for a sealant.

[0050] The aqueous primer composition according to the embodiment of the present invention can be suitably used, for example, as a primer for use in architectural or automotive sealants. Examples of methods for using the aqueous primer composition of the present invention include a method including applying the aqueous primer composition of the present invention to the above-mentioned substrate and optionally drying to form a primer layer; applying a sealant composition on the primer layer, and then drying and curing the aqueous primer composition and the sealant composition to form a sealant layer.

[0051] As long as the sealant layer of the present invention can be formed, the sealant used is not particularly limited, and a conventionally known sealant, preferably a construction sealant, can be used.Specific examples include silicone sealants, modified silicone sealants, polyurethane sealants, and polysulfide sealants.Polyurethane sealants, particularly polyurethane sealants for construction, can be preferably used.

[0052] In a preferred aspect, the present invention provides a method for using a new aqueous primer composition, the method including applying the aqueous primer composition of the embodiment of the present invention to an adherend to form a primer layer, and applying a sealant onto the primer layer. EXAMPLES

[0053] The present invention will be specifically and in detail explained below with reference to examples and comparative examples. However, these examples are merely one embodiment of the present invention, and the present invention is not limited to these examples in any way. In the description of the examples, unless otherwise specified, parts by weight and percentages by weight are based on the amounts not taking water into consideration.

[0054] The components used in this example are shown below. (A) Copolymer containing anionic urethane resin (a1) Polyether urethane resin emulsion (WBR-016U (product name) manufactured by Taisei Fine Chemical Co., Ltd.). Contains 30% by mass of solid content, has a Tg of 20° C., and contains a carboxylate group. (a2) Polycarbonate urethane resin emulsion (WBR-2101 (product name) manufactured by Taisei Fine Chemical Co., Ltd.). Contains 25% by mass of solid content, has a Tg of 40° C., and contains a carboxylate group. (a3) Polyester urethane resin emulsion (HYDRAN HW-311 (product name) manufactured by DIC Corporation). Contains 45% by mass of solid content, has an MFT of 0° C. or lower, and contains a carboxylate group. .

[0055] (B) Silyl group-containing acrylic resin emulsion (b1) Acrylic resin emulsion having a core-shell type silyl group (W3153CF (product name) manufactured by Kaneka Corporation). It contains 40% by mass of non-volatile matter, has a particle size of 100 nm, a Tg of 22°C, and an MFT of 45°C. (b2) Acrylic resin emulsion having a core-shell type silyl group (KD-6 (product name) manufactured by Henkel Japan Co., Ltd.). It contains 33 mass% of non-volatile matter, has a particle size of 50 nm, a Tg of 12°C, and an MFT of 0°C. (b3') Acrylic styrene resin emulsion (AD-8521 (product name) manufactured by Saiden Chemical Co., Ltd.). Contains 40% by mass of non-volatile matter, has a particle size of 120 nm, Tg of 38°C, and MFT of less than 0°C. Does not have a silyl group.

[0056] (E) Titanium coupling agent (e1) Titanium coupling agent (Orgatics TC-400 (product name) manufactured by Matsumoto Fine Chemical Co., Ltd.). Titanium diisopropoxybis(triethanolamine) 79% by mass (solvent containing 2-propanol)

[0057] (F)Other (f1) water

[0058] These components were mixed in the proportions shown in Tables 1 and 2 to prepare the aqueous primer compositions of Examples 1 to 8 and Comparative Examples 1 and 2. The components (A) to (F) were mixed in the ratios (parts by mass) shown in Tables 1 and 2 to prepare the aqueous primer compositions of Examples 1 to 8 and Comparative Examples 1 and 2. In this specification, the solid content refers to the non-volatile content measured according to condition B (temperature: 105°C, heating time: 3 hours) of JIS K 6828-1 (Synthetic resin emulsions - Part 1: Determination of non-volatile content). For each of the above-mentioned aqueous primer compositions, the simple adhesion (adhesion to mortar (after curing), joint adhesion (after curing)) was measured and evaluated by the following method. The results are shown in Tables 1 and 2.

[0059] Simple adhesion (adhesion to mortar (after curing), adhesion to joints (after curing)) Simple adhesion was evaluated in accordance with the 2017 edition of the Architectural Sealant Handbook (published by the Japan Sealant Industry Association). The surface of a given adherend (adherends 1 to 3 described below) was cleaned with toluene, and then a given primer (aqueous primer of an example or comparative example) was applied thereto and dried at room temperature for 60 minutes or more. Using the above-mentioned adherend and a 15x closed-cell polyethylene foam backing material, a test specimen (width 10 mm, thickness 8 mm, length 150 mm) was prepared as shown in Figure 1. MS2500NB type (two-component modified silicone sealant manufactured by Sunstar Engineering Co., Ltd.) or PU9000 type NB (two-component polyurethane sealant manufactured by Sunstar Engineering Co., Ltd.) was poured into the test specimen. This was cured at 23°C for one week, followed by another week at 50°C. After that, the sealant was pulled in a 180° direction and the adhesion state of the peeled area was visually observed according to the simple adhesion test in 6.2.1(2) of the 2017 edition of the Building Sealant Handbook (published by the Japan Sealant Industry Association).

[0060] Adherend 1: Mortar (prepared in accordance with JIS R 5201 10.4 using ordinary Portland cement as specified in JIS R 5210, manufactured by Engineering Test Services Co., Ltd.) (used to evaluate adhesion to mortar (after curing)) Substrate 2: Penguin Seal PU9000 type NB (two-component polyurethane sealant manufactured by Sunstar Engineering Co., Ltd.) (used to evaluate joint adhesion (after curing)) The evaluation criteria are as follows: ○: The entire specimen is a cohesion failure (CF), or CF and thin cohesion failure (TCF) are mixed. △: The whole is TCF. ×: Adhesion failure (AF) was observed.

[0061] [Table 1]

[0062] [Table 2]

[0063] None of the aqueous primer compositions of Examples 1 to 8 were rated x, which indicates that it is possible to improve adhesion to porous members and adhesion to existing sealants. The aqueous primer compositions of Comparative Examples 1 and 2 were rated "x" and were poor in adhesion. [Industrial Applicability]

[0064] The aqueous primer composition according to the embodiment of the present invention contains (A) a copolymer containing an anionic acrylic polymer and (B) a silyl group-containing acrylic resin emulsion, and has excellent adhesion to adherends such as aluminum, and can improve adhesion to porous members and adhesion to existing sealants. Therefore, the aqueous primer composition according to the embodiment of the present invention can be suitably used for architectural adherends.

Claims

1. 1. An aqueous primer composition comprising an organic polymer dispersed in an aqueous medium, (A) an anionic urethane resin emulsion, and (B) Silyl group-containing acrylic resin emulsion 1. An aqueous primer composition comprising:

2. 2. The aqueous primer composition according to claim 1, wherein the anionic urethane resin emulsion (A) comprises an anionic urethane resin emulsion (A1) having a polyoxyalkylene skeleton.

3. 3. The aqueous primer composition according to claim 1, wherein the anionic urethane resin emulsion (A) comprises an anionic urethane resin emulsion (A2) having a polyester and / or polycarbonate skeleton.

4. The aqueous primer composition for a sealant according to claim 1, which is used between a sealant and an adherend.

5. Applying the aqueous primer composition according to claim 1 to an adherend to form a primer layer; and Apply a sealant over the primer layer. A method for applying a sealant, comprising:

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