Aqueous primer composition

Abstract

To provide an aqueous primer composition which has excellent adhesion, and can improve water resistance and storage stability.SOLUTION: An aqueous primer composition containing an organic polymer dispersed in an aqueous medium contains (A) a copolymer containing a cationic acrylic polymer, and (B) a bisphenol type epoxy resin. 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] Special Publication No. 7-122034 [Patent Document 2] International Publication No. 2014 / 0580123 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem with water-based primers is that they have poor wettability with 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 demand for improved water resistance and storage stability with respect to water-based primers. [Means for solving the problem]

[0005] As a result of extensive research, the present inventors have found that an aqueous primer composition containing (A) a copolymer containing a cationic acrylic polymer and (B) a bisphenol-type epoxy resin has excellent adhesion, and is also capable of improving water resistance and storage stability, 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) A copolymer containing a cationic acrylic polymer (B) Bisphenol-type epoxy resin An aqueous primer composition comprising 2. The aqueous primer composition according to claim 1, wherein a portion of the copolymer containing (A) the cationic acrylic polymer contains a quaternary ammonium group based on epichlorohydrin and an amino group. 3. The aqueous primer composition according to 1 or 2 above, wherein a part of the copolymer containing the cationic acrylic polymer (A) further contains a reactive silyl group. 4. The aqueous primer composition according to any one of 1 to 3 above, further comprising a silane coupling agent, the silane coupling agent including at least one selected from a silane coupling agent having an amino group and a silane coupling agent having an epoxy group. 5. (C) The aqueous primer composition according to any one of 1 to 4 above, which is neutralized with an acid. 6. An aqueous primer composition for a sealant according to any one of 1 to 5 above, which is used between a sealant and an adherend. 7. Applying the aqueous primer composition according to any one of 1 to 6 above to an adherend to form a primer layer; Apply a sealant over the primer layer. A method of using the aqueous primer composition comprising: Effect of the Invention

[0007] The aqueous primer composition according to the embodiment of the present invention contains (A) a copolymer containing a cationic acrylic polymer and (B) a bisphenol-type epoxy resin, and has excellent adhesion, and can improve water resistance and storage stability. 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) a copolymer containing a cationic acrylic polymer, and (B) Bisphenol-type epoxy resin 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) a copolymer containing a cationic acrylic polymer and (B) a bisphenol-type epoxy 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, the copolymer containing a cationic acrylic polymer (A) (also referred to as the copolymer (A)) is a copolymer obtained by polymerizing at least one selected from an acrylic acid ester and a methacrylic acid ester and containing a polymer having a cationic group, and is not particularly limited as long as the aqueous primer composition targeted 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.

[0012] 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.

[0013] Examples of cationic groups include quaternary ammonium groups based on tertiary amino groups. Examples of such tertiary amino groups include dialkylamino groups such as dimethylamino groups, diethylamino groups, dibutylamino groups, dihexylamino groups, di(t-butyl)amino groups, diisohexylamino groups, and di(t-butyl)amino groups; and pyridinyl groups such as pyridinyl groups (pyridine groups) and 2-methylpyridinyl groups.

[0014] The method for introducing the above-mentioned tertiary amino group into the copolymer (A) is not particularly limited as long as it is possible to obtain the aqueous primer composition targeted by the present invention. For example, a method in which a monomer having a tertiary amino group is copolymerized with at least one selected from the above-mentioned acrylic acid esters and methacrylic acid esters can be exemplified. Examples of monomers having a tertiary amino group include N,N-dialkylaminoalkyl (meth)acrylates such as dimethylaminomethyl (meth)acrylate, diethylaminomethyl (meth)acrylate, dibutylaminomethyl (meth)acrylate, dihexylaminomethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, di(t-butyl)aminoethyl (meth)acrylate, diisohexylaminoethyl (meth)acrylate, dihexylaminopropyl (meth)acrylate, and di(t-butyl)aminohexyl (meth)acrylate; vinylpyridines such as vinylpyridine and 2-methylvinylpyridine; N,N-dimethylaminoalkyl vinyl ethers such as dimethylaminovinyl ether; and N,N-dimethylaminoethyl alkylamides.

[0015] Examples of the quaternary ammonium group based on a tertiary amino group include a tertiary amino group and, for example, a quaternary ammonium group based on epichlorohydrin. A tertiary amino group and a quaternary ammonium group based on epichlorohydrin are more preferred. The amount of epichlorohydrin may be, for example, 0.1 to 15 parts by mass, 1 to 12 parts by mass, or 2 to 10 parts by mass per 100 parts by mass of the copolymer containing the cationic acrylic polymer (A) (not including the aqueous medium).

[0016] A portion of the copolymer containing the cationic acrylic polymer (A) may further contain a reactive silyl group. In this specification, the reactive silyl group refers to a group that, in the presence of water, is hydrolyzed to generate a silanol group, and the silanol groups can further react with each other to generate a siloxane bond. There are no particular limitations on the reactive silyl group as long as the aqueous primer composition intended by the present invention can be obtained. 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).

[0017] The method for introducing the above-mentioned reactive silyl group into the copolymer (A) is not particularly limited as long as it is possible to obtain the aqueous primer composition targeted by the present invention. For example, a method in which a monomer having a reactive silyl group is copolymerized with at least one selected from the above-mentioned acrylic acid esters and methacrylic acid esters can be exemplified. 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.

[0018] The copolymer (A) may contain monomers other than the above-mentioned monomers, so long as the aqueous primer composition according to the present invention is 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

[0019] The (A) copolymer may be neutralized with a (C) acid. The acid is not particularly limited as long as it is capable of neutralizing the basicity that the aqueous primer composition may exhibit based on the cationic groups of the (A) copolymer and the aqueous primer composition targeted by the present invention can be obtained. Examples of the acid include organic acids such as formic acid, acetic acid, and oxalic acid, and inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid, among which organic acids are preferred, and formic acid, acetic acid, and the like are more preferred. (C) Neutralization with an acid can provide an advantageous effect of reducing the interparticle distance during film formation, thereby forming a more uniform film.

[0020] The copolymer (A) may be dispersed in an aqueous medium, and the particle size is, for example, 10 to 900 nm, preferably 12 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 the copolymer (A) is 10 to 900 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 copolymer (A) can be measured at 25° C. using a concentrated particle size analyzer "FPAR-1000" (analyzer manufactured by Otsuka Electronics Co., Ltd.).

[0021] The Tg (glass transition temperature) of the copolymer (A) 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 Tg of the copolymer (A) is −50 to 100° C., the adhesiveness is more excellent. The Tg of the copolymer (A) 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.

[0022] The MFT (Minimum Film-forming Temperature) of the copolymer (A) 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 copolymer (A) is 0 to 60° C., the copolymer has superior film-forming properties at low temperatures. The MFT of the copolymer (A) can be measured by a minimum film-forming thermometer (manufactured by Rhopoint Instruments: MFFTB90).

[0023] The aqueous primer composition of the present embodiment may contain, for example, 10 to 90 parts by mass of the (A) copolymer per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium), preferably contains 20 to 70 parts by mass of the (A) copolymer, more preferably contains 25 to 60 parts by mass of the (A) copolymer, and even more preferably contains 30 to 45 parts by mass of the (A) copolymer. The aqueous primer composition of the embodiment of the present invention has superior adhesion to mortar when it contains 10 to 90 parts by mass of the copolymer (A) per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium).

[0024] Commercially available products can be used as the copolymer (A). Examples of such commercially available products include UW-600 (trade name) manufactured by Taisei Fine Chemical Co., Ltd., 3KW-3000 (trade name) manufactured by Taisei Fine Chemical Co., Ltd., KD-20 (trade name) manufactured by Henkel Japan Co., Ltd., Aron NW-400 (trade name) manufactured by Toa Gosei Co., Ltd., Aron A-3611A (trade name) manufactured by Toa Gosei Co., Ltd., Aron NW-7060 (trade name) manufactured by Toa Gosei Co., Ltd., Neocryl XK-12 (trade name) manufactured by Kusumoto Chemical Co., Ltd., Neocryl XK-16 (trade name) manufactured by Kusumoto Chemical Co., Ltd., and ACRONAL YS-800ap (trade name) manufactured by BASF Japan Co., Ltd.

[0025] In this specification, (B) bisphenol-type epoxy resin refers to a thermosetting resin that has a bisphenol skeleton and can be cured by generating a crosslinked network through the epoxy groups present, and is generally called an epoxy resin. There are no particular limitations on this term as long as the aqueous primer composition targeted by the present invention can be obtained. (B) The bisphenol type epoxy resin may be, for example, a glycidyl ether type epoxy resin, a glycidyl amine type epoxy resin, a glycidyl ester type epoxy resin, or the like.

[0026] The bisphenol epoxy resin (B) is an epoxy resin having a bisphenol skeleton, and is not particularly limited as long as the aqueous primer composition targeted by the present invention can be obtained. Examples of bisphenol type epoxy resins include diglycidyl ethers of bisphenol A, bisphenol F, brominated bisphenol A, and bisphenol AD.

[0027] The epoxy equivalent of the bisphenol type epoxy resin is preferably 200 to 5000 g / eq, more preferably 300 to 2500 g / eq, even more preferably 700 to 1500 g / eq, and even more preferably 500 to 1100 g / eq. When the epoxy equivalent of the bisphenol type epoxy resin is 200 to 5000 g / eq, the adhesiveness to acrylic electrodeposition-coated aluminum and the water-resistant adhesiveness to porous members are superior. The epoxy equivalent of the bisphenol type epoxy resin can be measured according to the potentiometric titration method of JIS K7236. The measurement can be performed using a commercially available potentiometric titrator (for example, AT-610 manufactured by Kyoto Electronics Manufacturing Co., Ltd.).

[0028] The bisphenol type epoxy resin may be dispersed in an aqueous medium. When the bisphenol type epoxy resin is dispersed in an aqueous medium, the aqueous primer composition of the embodiment of the present invention contains an organic polymer and a bisphenol type epoxy resin dispersed in the aqueous medium. The particle diameter of the bisphenol type epoxy resin is preferably 100 to 1000 nm, more preferably 150 to 800 nm, even more preferably 200 to 700 nm, and even more preferably 300 to 600 nm. When the particle diameter of the bisphenol type epoxy resin is 100 to 1000 nm, the water-resistant adhesion to the porous member is more excellent. The particle size of the bisphenol type epoxy resin can be measured by a concentrated particle size analyzer "FPAR-1000" (analyzer manufactured by Otsuka Electronics Co., Ltd.).

[0029] The aqueous primer composition of the embodiment of the present invention may contain, for example, 10 to 90 parts by mass of the (B) bisphenol type epoxy resin per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium), preferably contains 20 to 80 parts by mass of the (B) bisphenol type epoxy resin, more preferably contains 30 to 70 parts by mass of the (B) bisphenol type epoxy resin, even more preferably contains 30 to 75 parts by mass of the (B) bisphenol type epoxy resin, and even more preferably contains 50 to 70 parts by mass of the (B) bisphenol type epoxy resin. The aqueous primer composition according to an embodiment of the present invention, when it contains 10 to 90 parts by mass of (B) bisphenol type epoxy resin per 100 parts by mass of the aqueous primer composition (excluding the aqueous medium), provides a coating film with better hardness and water resistance.

[0030] Commercially available bisphenol-based epoxy resins can be used, such as EM-101-50 (product name) manufactured by ADEKA Corporation and jERW2821R70 (product name) manufactured by Mitsubishi Chemical Corporation.

[0031] The ratio ((A) / (B)) (mass ratio) of the copolymer (A) to the bisphenol epoxy 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, 80 / 20 to 20 / 80, preferably 70 / 30 to 25 / 75, more preferably 65 / 35 to 30 / 70, and even more preferably 55 / 45 to 35 / 65. When the ratio ((A) / (B)) (mass ratio) of the copolymer (A) to the bisphenol type epoxy resin (B) is 80 / 20 to 20 / 80, excellent joint adhesion is achieved.

[0032] The aqueous primer composition of the present invention may further include a silane coupling agent. In this specification, the silane coupling agent is a compound containing Si, 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 the silane coupling agent include silane coupling agents having an amino group, silane coupling agents having an epoxy group, silane coupling agents having a hydroxyl group, silane coupling agents having a mercapto group, and silane coupling agents having an ethylenic double bond, but it is preferable to include at least one selected from silane coupling agents having an amino group and silane coupling agents having an epoxy group. The Si-containing group (silyl group) of the silane coupling agent preferably contains trimethoxy, methyldimethoxy, triethoxy or methyldiethoxy.

[0033] More specifically, examples of the silane coupling agent include silane coupling agents having an amino group, such as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, and N-phenyl-3-aminopropyltrimethoxysilane; and silane coupling agents having an epoxy group, such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane. When the aqueous primer composition of the embodiment of the present invention contains at least one selected from a silane coupling agent having an amino group and a silane coupling agent having an epoxy group, it can exhibit the advantageous effect of excellent adhesion after durability.

[0034] The silane coupling agent more preferably includes a reaction product of a silane coupling agent having an amino group and a silane coupling agent having an epoxy group. The reaction product of a silane coupling agent having an amino group and a silane coupling agent having an epoxy group can be obtained by mixing and appropriately heating. The reaction product more preferably includes a compound containing two or more alkoxy groups, NH groups and OH groups in the molecule (corresponding to a silane coupling agent having an amino group). The reaction ratio of the silane coupling agent having an amino group and the silane coupling agent having an epoxy group (silane coupling agent having an amino group / silane coupling agent having an epoxy group) is not particularly limited, but for example, the weight ratio of the silane coupling agent having an amino group and the silane coupling agent having an epoxy group can be 1 / 1 to 5 / 1, preferably 1 / 1 to 4 / 1, more preferably 2 / 1 to 3.5 / 1, and particularly preferably 3 / 1. The silane coupling agent is excellent in both adhesiveness and storage stability when it contains a reaction product of a silane coupling agent having an amino group and a silane coupling agent having an epoxy group.

[0035] The aqueous primer composition of the present invention preferably contains 0.1 to 5 parts by mass of the silane coupling agent, more preferably contains 0.5 to 3 parts by mass of the silane coupling agent, and even more preferably contains 0.8 to 2 parts by mass of the silane 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 silane 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 silane coupling agent having an amino group and a silane coupling agent having an epoxy group, it can have the advantageous effect of providing better adhesion after durability testing.

[0036] The aqueous primer composition of the present embodiment 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 65 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).

[0037] 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, ultraviolet absorbers, plasticizers, lubricants, antistatic agents, reinforcing materials, flame retardants, catalysts, defoamers, thickeners, dispersants, surfactants, 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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; and applying a sealant composition onto the primer layer, and then drying and curing the aqueous primer composition and the sealant composition to form a sealant layer.

[0042] 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.

[0043] 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

[0044] 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.

[0045] The components used in this example are shown below. (A) A copolymer containing a cationic acrylic polymer (a1) Core-shell type acrylic styrene emulsion (UW-600 (trade name) manufactured by Taisei Fine Chemical Co., Ltd.). Contains 34% by mass of solid content, particle size 60 nm, Tg of the core 20°C, Tg of the shell 20°C, MFT 4°C, and contains, in addition to acrylic styrene polymer, formic acid, epichlorohydrin and a quaternary ammonium group based on an amino group, and dipropylene glycol monomethyl ether, including polymer components that have reacted with each other. The solid content is considered to substantially correspond to the (A) copolymer, and is therefore considered to be the content of the (A) copolymer. (a2) Core-shell type acrylic styrene emulsion (3KW-3000 (trade name) manufactured by Taisei Fine Chemical Co., Ltd.). Contains 28.5% by mass of solid content. Particle size is 300 nm, Tg of the core is 20°C, Tg of the shell is 20°C, MFT is 4°C, and contains, in addition to acrylic styrene polymer, formic acid, epichlorohydrin and a quaternary ammonium group based on an amino group, and dipropylene glycol monomethyl ether, and also includes those that have reacted with each other, including the polymer component. (a3) Acrylic silicone dispersion (KD-20 (product name) manufactured by Henkel Japan Co., Ltd.). Contains 20% by mass of solid content, particle size of 20 nm, Tg of 42° C., MFT of 0° C., reactive silyl group, and film-forming assistant.

[0046] (B) Epoxy resin (b1) Bisphenol A type epoxy resin (EM-101-50 (product name) manufactured by ADEKA CORPORATION). It contains 46 mass% solid content, has a particle size of 400 nm, has an epoxy equivalent of 1075 g / eq, and contains propylene glycol monomethyl ether and benzyl alcohol.

[0047] (E) Silane coupling agent (e1) Epoxy silane coupling agent (KBM-403 (product name) manufactured by Shin-Etsu Chemical Co., Ltd.). 3-Glycidoxypropyltrimethoxysilane (e2) Aminosilane coupling agent (KBM-603 (product name) manufactured by Shin-Etsu Chemical Co., Ltd.). N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (e3) A reaction product of an epoxy silane coupling agent (KBM-403 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd.) and an amino silane coupling agent (KBM-603 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd.). (e3) was synthesized as follows. 25 g of 3-glycidoxypropyltrimethoxysilane (KBM-403) and 75 g of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (KBM-603) were heated and mixed at 50°C for 72 hours to synthesize (e3).

[0048] (F)Other (f1) Defoamer (SB630 (product name) manufactured by Kyoeisha Chemical Co., Ltd.). Emulsion of organic modified polysiloxane and special polymer. Contains 25% by mass of solids. (f2) Coagulant (EHG (product name) manufactured by Nippon Nyukazai Co., Ltd.). Ethylene glycol mono 2-ethylhexyl ether. (f3) Water

[0049] 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 9 and Comparative Examples 1 and 2. In this specification, the solid content refers to the non-volatile content measured under test conditions of 105° C. for 3 hours in accordance with 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 (water resistance), joint adhesion (after curing), adhesion to acrylic electrodeposition-coated aluminum (water resistance)) and storage stability were measured and evaluated by the following methods. The results are shown in Tables 1 and 2.

[0050] Simple adhesion (adhesion to mortar (water resistance), adhesion to joints (after curing), adhesion to acrylic electrocoated aluminum (water resistance)) 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 15-fold independent polyethylene 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 one week at 50°C. Furthermore, in the case of evaluating water resistance, after the above-mentioned curing, it was immersed in water at 23°C for one week and then left to stand for 24 hours. After that, in accordance with 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), the sealant was pulled in a 180-degree direction, and the adhesion state of the peeled area was visually observed.

[0051] 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 (water resistance) to mortar) Substrate 2: Penguin Seal PU9000 type NB (two-component polyurethane sealant manufactured by Sunstar Engineering Co., Ltd.) (used to evaluate joint adhesion (after curing)) Substrate 3: Acrylic electrodeposition-coated aluminum (LIXIL Corporation acrylic electrodeposition-coated aluminum sash, autumn brown) (used to evaluate adhesion (water resistance) to acrylic electrodeposition-coated aluminum) The evaluation criteria are as follows: ○: Includes cases where the entire specimen is a cohesive failure (CF, Cohesive Failure) and some specimens are a thin cohesion failure (TCF, Thin Cohesion Failure). ○ / △: Overall, cohesive failure (CF) and thin layer cohesive failure (TCF) are mixed. △: The whole is TCF. ×: Adhesive failure (AF) was observed.

[0052] Storage stability After preparation, each of the aqueous primer compositions was stored at 50° C. for one week. Thereafter, the viscosity was measured at 20° C. at a rotation speed of 30 rpm using a BM type viscometer with a spindle No. 3. The evaluation criteria are as follows: ○: 4000 mPa s or less. △: Exceeds 4000 mPa·s, but can be applied. ×: Gelled and unable to be applied.

[0053] [Table 1]

[0054] [Table 2]

[0055] All of the aqueous primer compositions of Examples 1 to 9 had no "x" and exhibited excellent adhesion and storage stability. The aqueous primer compositions of Comparative Examples 1 and 2 were rated as x and were poor in either adhesion or storage stability. [Industrial Applicability]

[0056] The aqueous primer composition according to the embodiment of the present invention contains (A) a copolymer containing a cationic acrylic polymer and (B) a bisphenol-type epoxy resin, and has excellent adhesion, and can improve water resistance and storage stability. 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) Copolymer containing a cationic acrylic polymer (B) Bisphenol-type epoxy resin An aqueous primer composition comprising

2. 2. The aqueous primer composition according to claim 1, wherein a portion of the copolymer containing the cationic acrylic polymer (A) contains a quaternary ammonium group based on epichlorohydrin and an amino group.

3. 3. The aqueous primer composition according to claim 1, wherein a part of the copolymer containing the cationic acrylic polymer (A) further contains a reactive silyl group.

4. 3. The aqueous primer composition according to claim 1, further comprising a silane coupling agent, the silane coupling agent including at least one selected from a silane coupling agent having an amino group and a silane coupling agent having an epoxy group.

5. The aqueous primer composition according to claim 1 or 2, which is neutralized with (C) an acid.

6. The aqueous primer composition for a sealant according to claim 1 or 2, which is used between a sealant and an adherend.

7. Applying the aqueous primer composition according to claim 1 or 2 to an adherend to form a primer layer; Apply a sealant over the primer layer. A method of using the aqueous primer composition comprising:

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