JP2000204285A - Aqueous sealer and in-line coating method for ceramic substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aqueous sealer excellent in resistances to water, blocking, and efflorescence by incorporating an aqueous resin mixture comprising a synthetic resin emulsion and an aqueous resin solution, as the base resin component, into the same. SOLUTION: This sealer is prepared by compounding 100 pts.wt. (solid basis) core-shell type synthetic resin emulsion with 100-10,000 pts.wt. (solid basis) aqueous resin solution. The synthetic resin emulsion has an average particle size of 80-200 nm and a glass transition temperature of -20 to 120 deg.C, and the glass transition temperature of the core is -20 to 50 deg.C; the glass transition temperature of the shell is 50 deg.C or higher; and the sum of the glass transition temperatures of the core and shell is 30 deg.C or lower. The aqueous resin solution contains at least one water-soluble resin selected from among vinyl resins, polyester resins, polyurethane resins, epoxy resins, and modifications of these resins. The sealer is applied to the surface of an inorganic porous substrate in a coating weight of 0.1-30 g/m2, then dried at temperatures of 20-200 deg.C for 3 sec to 60 min, and cured in an autoclave at a temp. of 160-170 deg.C under a pressure of 8-9 kgf/cm2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel aqueous sealer and a method for coating the same.

[0002]

2. Description of the Related Art In recent years, as an outer wall material of a building, an inorganic material is formed into a plate shape, then subjected to primary curing, in-line sealer application, drying, autoclave curing, cutting, preheating, second sealing application, and then drying. To produce a sealer plate, or after the above preheating, overcoating and drying to produce an overcoated plate.

The above-mentioned in-line sealer is used for improving performance such as anti-mold resistance, salt damage resistance, weather resistance, efflorescence resistance, and adhesion to a second sealer coating film and a top coating film. .

Conventionally, an aqueous humic acid solution or a thermoplastic acrylic resin emulsion has been used as an in-line sealer. However, the humic acid aqueous solution has the drawback of poor adhesion to the second sealer coating and the top coat, and the thermoplastic acrylic resin emulsion has an autoclave cure (usually at 160 to 170 ° C. and 8 to 9 kgf).
/ Cm ² , for 4 to 8 hours in the presence of water vapor), the substrates adhere to each other and are blocked, making handling difficult.

Further, copolymers containing 0.5 to 30% by weight of a carbonyl group-containing unsaturated monomer are disclosed in JP-A-5-247376 and JP-A-6-27.
No. 9707. However, when such a copolymer is applied to an inline sealer, there is a problem that the blocking resistance is not sufficient.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous sealer and a coating method for the same, which are capable of satisfying the required film performance such as water resistance, blocking resistance, and efflorescence resistance required for the aqueous sealer. is there.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems, and as a result, used a mixed resin aqueous solution of an emulsion and a water-soluble resin solution as a resin component. The inventor has found that an aqueous sealer solves the conventional problems, and has completed the present invention.

That is, the present invention is suitable for a ceramic base material characterized by comprising, as a base resin component, a mixed resin aqueous solution of a synthetic resin emulsion (I) and a water-soluble resin solution (II). 2, a synthetic resin emulsion (I) having a core part having a glass transition temperature of −20 to 50 ° C., a shell part having a glass transition temperature higher than 50 ° C., and a total glass transition temperature of both parts being 30 ° C. The above-mentioned aqueous sealer, which is a core-shell type emulsion as follows: 3, The above-mentioned aqueous sealer, wherein the synthetic resin emulsion (I) contains a hydroxyl group in a shell part. The above aqueous sealer, wherein the water-soluble resin solution (II) is water-soluble by a carboxyl group and / or a carbonyl group. The above-mentioned aqueous sealer, which is a thermosetting type; 6, the above-mentioned aqueous sealer, wherein the water-soluble resin solution (II) is a vinyl-based water-soluble resin solution; 7, the water-soluble resin The aqueous sealer as described above, wherein the solution (II) contains a (meth) acrylamide monomer or a derivative thereof as a monomer component constituting the vinyl-based water-soluble resin solution. 8, In-line with the surface of the inorganic porous substrate The present invention relates to an inline coating method for a ceramic base material, wherein the inline sealer is the above-mentioned aqueous sealer in a step including autoclaving after coating and drying the sealer.

In the present specification, the glass transition temperature (° C.) of the polymer can be calculated by the following equation.

1 / Tg (゜ K) = (W / T) + (W / T) + · Tg (° C) = Tg (゜ K) -273 In the formula, W, W,. , T, T,... Each represent the Tg (ΔK) of the homopolymer of the monomer. T, T, ...
Is the Polymer Hand Book (Scond
Edition, J.M. Brandup E. H. Im
mergut).

Further, the glass transition temperature of other than the polymer (° C.)
Uses Vibron Dynamic Viscoelastic System DAYNAMIC VI
SCO ELASTOMETER MODEL VIBRON DDV-IIEA type (TOYO BA
The dynamic glass transition temperature (° C.) was measured at a frequency of 110 Hz and a heating rate of 3 ° C./min using CDWINCO. The sample was measured on an isolated coating film after coating on a polypropylene plate.

In the present specification, the average particle diameter (nm) is
The measurement was carried out using an emulsion or a water-soluble resin solution having a solid content of 30%, Nanosizer N-4, manufactured by COLTAL Corporation.

The aqueous sealer of the present invention will be described below.

As the synthetic resin emulsion (I) used in the present invention, a conventionally known synthetic resin emulsion or the following core-shell type emulsion can be used.
These emulsions usually have an average particle size of about 80 nm to 2 nm.
00 nm, especially in the range of about 90 nm to 150 nm, is preferred. When the average particle size of the emulsion is less than about 80 nm, the overcoat adhesion of the coating film is reduced, while the
If it exceeds m, the blocking resistance and the like are undesirably reduced. Further, these emulsions preferably have a glass transition temperature of -20 to 120C, particularly preferably -10 to 100C. When the glass transition temperature is lower than -20 ° C, the blocking resistance and the like of the coating film decrease, while when the glass transition temperature exceeds 120 ° C, the film forming property of the coating film and the like decrease, which is not preferable.

Conventionally known synthetic resin emulsions include vinyl acetate emulsions, ethylene-vinyl acetate copolymer emulsions, vinyl acetate-alkyl (meth) acrylate copolymer emulsions, and alkyl (meth) acrylate emulsions. Polymer emulsion, styrene-butadiene copolymer emulsion, styrene-alkyl (meth) acrylate copolymer emulsion, maleated polybutadiene polymer emulsion, vinyl chloride emulsion, vinyl chloride
Examples include a vinylidene chloride copolymer-based emulsion, a synthetic rubber latex-based emulsion, a polyester resin-based emulsion, a silicone resin-based emulsion, a fluororesin-based emulsion, a urethane resin-based emulsion, and an epoxy resin-based emulsion.

The synthetic resin emulsion (I) may be an uncrosslinked type or a crosslinked type.

As the above-mentioned core-shell type emulsion, for example, the following can be suitably used. The core
The shell-type emulsion is an aqueous dispersion of polymer particles, and the polymer particles are composed of a core (core) and a coating (shell) covering the periphery thereof. It can be prepared by a seed polymerization method or the like.

Specifically, a monomer mixture (i) consisting of a) a carboxyl group-containing unsaturated monomer and b) an unsaturated monomer (excluding a) is emulsion-polymerized in water. A core portion is formed (seed polymerized latex), and then c) (meth) acrylate, d) a carboxyl group-containing unsaturated monomer and e) an unsaturated monomer (provided that c A core-shell type emulsion is obtained by adding a monomer mixture (ii) consisting of (a) and (d), and by subjecting the mixture to emulsion polymerization to form a shell portion.

A) The carboxyl group-containing unsaturated monomer is
It is a compound having at least one carboxyl group and at least one polymerizable double bond in one molecule, and examples thereof include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, and maleic anhydride.

B) The unsaturated monomer is a compound having at least one polymerizable double bond in one molecule, and does not include the above a). For example, an esterified product of acrylic acid or methacrylic acid and a monoalcohol having 1 to 20 carbon atoms; an aromatic monomer such as styrene and vinyltoluene; a vinyl ester such as vinyl acetate, vinyl propionate and vinyl versatate; Vinyl halides such as acrylonitrile and methacrylonitrile; vinyl halides such as vinyl chloride, vinylidene chloride and vinyl fluoride; acrylamide, methacrylamide, diacetone acrylamide, diacetone methacrylamide, glycidyl acrylate, glycidyl methacrylate , Hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, N-methylol acrylamide, N-butoxymethyl acrylamide, methacrylate Le acid acidphosphoxyethyl ethyl, acrylate, 3-chloro-2-acid phosphoxy propyl, methyl propane sulfonic acid acrylamide, divinyl benzene, allyl acrylate,
Allyl methacrylate, (poly) oxyethylene diacrylate, (poly) oxyethylene dimethacrylate, trimethylolpropane triacrylate, trimethylol
Lepropane trimethacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate
And functional group-containing monomers such as allylsulfosuccinic acid and styrenesulfonic acid.

The ratio of the monomer a) to the monomer b) in the monomer mixture (i) is not particularly limited, but the ratio of the monomer a) is 0.1% based on the total weight of both components. 05-50
%, Especially 0.5 to 5%, monomer b) is 99.95 to 50
%, Especially in the range of 99.5 to 95%, is suitable.

The core portion can be prepared by polymerizing the monomer mixture (i) in water by a usual emulsion polymerization method. As the polymerization catalyst, water-soluble or oil-soluble potassium persulfate, ammonium persulfate, sodium persulfate, hydrogen peroxide, t-butyl hydroperoxide,
t-butyl peroxybenzoate, 2,2-azobisisobutyronitrile, 2,2-azobis (2-amidinopropane) hydrochloride, 2,2-azobis (2,4-dimethylvaleronitrile) and the like. And
Among them, water-soluble ones are particularly preferable. The amount used is preferably 0.1 to 1% by weight of the monomer mixture (i). Further, in order to promote the polymerization rate or to perform low-temperature polymerization, a reducing agent such as sodium bisulfite, ferrous chloride, ascorbate, or Rongalit can be used in combination. Furthermore, known polymerization regulators and surfactants can be used as necessary.

Next, c) (meth) acrylate, d) a carboxyl group-containing unsaturated monomer and e) an unsaturated monomer (provided that c) A) monomer mixture (ii) consisting of
Is added and emulsion polymerization is performed to form a shell portion, whereby a core-shell type emulsion is obtained.

The c) (meth) acrylic acid ester and d) the unsaturated monomer containing a carboxyl group are exemplified by the monomers a) and b) of the above monomer mixture (i). Can be applied. The monomer e) is a compound having at least one polymerizable double bond in one molecule, and excluding c) (meth) acrylate and d) a carboxyl group-containing unsaturated monomer. And those exemplified for the monomer b) of the monomer mixture (i) can be applied.

The above-mentioned hydroxyethyl acrylate and hydroxyethyl methacrylate are used as the monomer components c).
A hydroxyl group can be introduced into the shell portion by using a hydroxyl group-containing monomer such as hydroxypropyl acrylate and hydroxypropyl methacrylate. The content of the hydroxyl group is about 10 to 200 KOH mg / g, particularly about 20 to 1 based on the shell resin.
A range of 50 KOHmg / g is preferred. The hydroxyl group forms a crosslinked coating film by a crosslinking agent which reacts with a hydroxyl group such as a melamine resin blended as necessary, and can form a coating film having excellent water resistance, blocking resistance and the like.

The proportion of these monomers in the monomer mixture (ii) is not particularly limited, but based on the total weight of these monomers, monomer c) is 15 to 100%, Suitably, d) is in the range of 0 to 15% and monomer e) is in the range of 0 to 70%. In the emulsion polymerization for forming the shell portion, the above-mentioned polymerization catalyst, reducing agent, and further, a polymerization regulator, a surfactant and the like can be used as necessary.

In the above-mentioned core-shell type emulsion, the composition ratio of the monomer mixture (i) and the monomer mixture (ii) is not particularly limited, but based on the total weight of both components, i) is from 5 to 80%, especially from 10 to 60%
%, The monomer mixture (ii) is 95 to 20%, especially 90 to 90%.
A range of 40% is suitable.

In particular, the above-mentioned core-shell type emulsion has a glass transition temperature of the core portion of -20 to 50 ° C., particularly 0 to 4 ° C.
0 ° C., the glass transition temperature of the shell part is higher than 50 ° C., particularly in the range of 50 to 105 ° C., and the total glass transition temperature of both parts is 30 ° C. or less, particularly 10 to 30 ° C.
Is preferably within the range.

The total glass transition temperature of the core part and the shell part is obtained by (weight% of core part × glass transition temperature of core part) + (weight% of shell part × glass transition temperature of shell part).

In the core-shell type emulsion, when the glass transition temperature of the core portion is lower than -20 ° C., the formed coating film tends to be blocked, while when the glass transition temperature is higher than 50 ° C., the film-forming properties and low-temperature physical properties (freezing and thawing test). Etc. decrease. When the glass transition temperature of the shell portion is 50 ° C. or less, the formed coating film is easily blocked, and when the total glass transition temperature of both portions is 30 ° C. or more, the film-forming properties and low-temperature physical properties (freezing and thawing test) deteriorate. Are not preferred.

In the above-mentioned synthetic resin emulsion (I), one or more selected from alcohol components having a boiling point (BP) of 100 to 270 ° C. can be used as a film-forming auxiliary. As such an alcohol component, specifically,
Ethylene glycol monobutyl ether (butyl cellosolve, molecular weight 118, BP 171 ° C), diethylene glycol monobutyl ether (butyl carbitol, molecular weight 162, BP 230 ° C), diethylene glycol monobutyl ether butyl acetate (butyl carbitol acetate, molecular weight 206; BP 246 ° C), propylene glycol monomethyl ether (molecular weight 90, BP120
° C). Further, (CH) CHCOOC
2, represented by HC (CH) C (OH) HCH (CH)
2,4-trimethyl 1,3-pentanediole monoisobutyrate (Texanol, molecular weight 216, BP248
° C) is also effective as a film-forming aid.

If the boiling point of the alcohol component is lower than 100 ° C., the coatability (film-forming property) of the coating film is not sufficient, and if the boiling point is higher than 270 ° C., the alcohol component tends to remain in the coating film and become water- and moisture-resistant. It is not preferable because the properties and the like are reduced.

The content of the film-forming aid is not particularly limited, but is preferably 0.1 to 100 parts by weight of the resin solid content of the emulsion.
It is in the range of 1 to 10 parts by weight, preferably 0.3 to 4 parts by weight, more preferably 0.5 to 2 parts by weight.

Water-soluble resin solution (II) used in the present invention
Preferably has an average particle size of less than about 80 nm, particularly less than about 50 nm. If the average particle size of the water-soluble resin solution is about 80 nm or more, the blocking resistance and the like of the coating film are undesirably reduced.

The water-soluble resin solution (II) is not particularly limited as long as it satisfies the above-mentioned conditions, but it is preferable to use a solution made water-soluble by a carboxyl group and / or a carbonyl group. As the water-soluble resin solution (II), for example, an aqueous solution of at least one of the following water-soluble resins selected from vinyl resins, polyester resins, polyurethane resins, epoxy resins, and modified resins thereof can be used. The water-soluble resin can be made water-soluble by directly dissolving the resin in water or by adding a carboxyl group to a basic compound (eg, ammonia; ethylamine, propylamine, butylamine, benzylamine, monoethanolamine, neopentanolamine, 2-aminopropanol). Primary amines such as, 3-aminopropanol; secondary amines such as diethylamine, diethanolamine, di-n- or di-iso-propanolamine, N-methylethanolamine, N-ethylethanolamine; dimethylethanolamine; Neutralization with a tertiary amine such as trimethylamine, triethylamine, triisopropylamine, methyldiethanolamine, and dimethylaminoethanol, and an inorganic hydroxide such as sodium hydroxide and potassium hydroxide (neutralization equivalent: about 0.5 to 1.
5) After that, it can be dissolved in water.

(1) Vinyl resin: Examples of the vinyl resin include a carbonyl group-containing radically polymerizable vinyl monomer (i) in an amount of 0 to 60% by weight, preferably 5 to 45%.
Wt%, a carboxyl group-containing radical polymerizable vinyl monomer (ii) from 0 to 20 wt%, preferably from 5 to 15 wt%, and other radical polymerizable unsaturated monomers (ii)
i) A radical containing 20 to 94% by weight, preferably 40 to 90% by weight, and having a monomer content of (i) + (ii) in the range of 6 to 80% by weight, preferably 10 to 60% by weight. And copolymers. When the proportion of the monomer (i) exceeds the above range, there is a disadvantage that the coating performance such as water resistance is deteriorated. The above (ii)
When the blending ratio of the monomer is less than 2% by weight, for example,
There are drawbacks in that the permeability to the base material is reduced, the function cannot be sufficiently exhibited, and the performance such as blocking resistance (the inorganic porous building base material is difficult to adhere to and peel off from each other) is reduced. On the other hand, if it exceeds 20% by weight, there is a disadvantage that the water resistance and efflorescence resistance of the coating film are deteriorated.

If the total amount of the monomers (i) and (ii) is less than 6% by weight, the permeability to the substrate is poor, so that the performances such as blocking resistance and efflorescence resistance are deteriorated. %, There is a disadvantage that the performance such as water resistance of the coating film is deteriorated.

Carbonyl group-containing unsaturated monomer (i)
Is a monomer having at least one keto group or aldehyde group and one radically polymerizable double bond in one molecule, that is, a polymerizable monoolefinically unsaturated aldehyde compound and a keto compound. Representative specific examples include, for example, diacetone (meth) acrylamide, acrolein, formylstyrene, (meth) acrylamide pivalinaldehyde, diacetone (meth) acrylate, acetonyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate Acetyl acetate, vinyl alkyl ketone and the like can be mentioned. Of these, diacetone (meth) acrylamide is preferred.

The carboxyl group-containing unsaturated monomer (i
i) is an unsaturated compound containing at least one carboxyl group (including carboxyl anhydride group) and one radically polymerizable unsaturated group in one molecule. Typical specific examples include (meth) acrylic acid, maleic anhydride,
Fumaric acid, itaconic acid and the like.

The other radically polymerizable unsaturated monomer (iii) is a non-functional non-functional monomer which is a radically polymerizable unsaturated monomer other than the above and which does not substantially adversely affect (react, etc.) with the above-mentioned carbonyl group or carboxyl group. Unsaturated compound. Representative examples include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tertbutyl (meth) acrylate, -Ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, 2-ethylhexyl carbitol (meth) acryle -Alkyl or cycloalkyl ester monomers of (meth) acrylic acid such as iso- or isobornyl (meth) acrylate; methoxybutyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxybutyl (meth) acryl Alkoxyalkyl ester monomers of (meth) acrylic acid such as trimethylolpropane tripropoxy (meth) acrylate; aromatic vinyl monomers such as styrene, α-methylstyrene and vinyltoluene; aromatic alcohols such as benzyl (meth) acrylate And unsaturated monomers such as esters of (meth) acrylic acid; vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, 2-styrylethyltrimethoxy Silane, vinyltrichlorosilane,
Hydroxysilane and / or hydrolyzable silane group-containing vinyl such as γ- (meth) acryloyloxypropyltriacetoxysilane, γ- (meth) acryloyloxypropyltrihydroxysilane, and γ- (meth) acryloyloxypropylmethylhydroxysilane System monomer; perfluorobutylethyl (meth) acrylate,
Perfluoroisononylethyl (meth) acrylate,
Perfluoroalkyl (meth) acrylates such as perfluorooctylethyl (meth) acrylate are exemplified.

In addition to the above, as other monomers, amide monomers represented by the following general formula (1) and derivatives thereof (hereinafter, these are simply referred to as “amide monomers”)

[0042]

Embedded image

(Wherein, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a methylol group or a —R ₃ OR ₄ group, provided that R ₃ represents a divalent hydrocarbon group having 1 to 4 carbon atoms. R ₄ represents an alkyl group having 1 to ₄ carbon atoms.) Examples of the divalent hydrocarbon group having 1 to 4 carbon atoms of R ₃ represented by the general formula (1) include CH ₂ , C ₂ H ₄ , C ₃ H ₆ , C ₄
H _{8 and the} like are included. Examples of the alkyl group having 1 to ₄ carbon atoms for R ₄ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an iso-
A butyl group, a tert-butyl group and the like are included. In the general formula (1), R ₃ is preferably CH ₂ or C
₂ H ₄ , and R ₄ is preferably a methoxy group, an ethoxy group, a butoxy group, or the like.

Examples of the amide monomer include N-methylolacrylamide, N-methylolmethacrylamide, Nnbutoxymethylacrylamide, Nnbutoxymethylmethacrylamide and the like.

When the amide monomer is blended, the proportion of the monomer component constituting the copolymer is 5 to 60% by weight, preferably 5 to 40% by weight. When the blending ratio of the amide monomer (a) is less than 5% by weight, there is a serious disadvantage that the inorganic porous base materials adhere to each other in the autoclave curing step and become difficult to peel off (blocking resistance). If the ratio exceeds, the water resistance and the like deteriorate.

The vinyl resin is preferably produced by a solution polymerization method. Specifically, for example, a radical polymerization initiator (for example, an azo-based initiator, a peroxide-based initiator, or the like) is prepared by using the above-described radical-polymerizable monomer in a solvent containing a hydrophilic organic solvent such as an alcohol solvent or an ether solvent. By reacting at a temperature of about 50 to 140 ° C. for about 4 to 10 hours in the presence of

The vinyl resin has a number average molecular weight of about 100.
The range of 0-100,000, especially 2000-50000 is preferable. When the number average molecular weight is less than about 1000, water resistance and the like decrease, while when the number average molecular weight exceeds 100000, the permeability to the base material is deteriorated, and the blocking resistance is deteriorated.

(2) Polyester resin: As the polyester resin, for example, a polybasic acid (for example, (anhydrous))
Phthalic acid, isophthalic acid, terephthalic acid, (anhydrous) maleic acid, (anhydrous) pyromellitic acid, (anhydrous) trimellitic acid, (anhydrous) succinic acid, sebacic acid, azelaic acid,
Compounds having 2 to 4 carboxyl groups or carboxylic acid methyl ester groups in one molecule such as dodecanedicarboxylic acid, dimethyl isophthalate, dimethyl terephthalate, etc.)
And polyhydric alcohols (eg, ethylene glycol, propylene glycol, neopentyl glycol, 1,6-
Hexanediol, diethylene glycol, triethylene glycol, trimethylolpropane, pentaerythritol, glycerin, tricyclodecanedimethanol, dimethylolpropionic acid, and other alcohols having 2 to 6 hydroxyl groups in one molecule) are required for aqueous conversion. It is obtained by performing an esterification reaction or a transesterification reaction such that a sufficient carboxyl group remains. In addition to the above, monobasic acids (for example, fatty acids such as castor oil fatty acid, soybean oil fatty acid, tall oil fatty acid, and linseed oil fatty acid, and benzoic acid), and fats and oils can be used as necessary.

The carboxyl group of the polyester resin has a resin acid value of about 10 to 200 KOH mg / g, preferably about 20 to 150 KOH mg / g. When the acid value is below the lower limit, the permeability to the substrate is poor, and the performance such as blocking resistance and efflorescence resistance deteriorates. On the other hand, when the acid value exceeds the upper limit, the performance such as the water resistance of the coating film deteriorates. There are drawbacks.

The polyester resin preferably has a number average molecular weight of about 500 to 20,000, particularly preferably 700 to 10,000. When the number average molecular weight is less than about 500, the water resistance and the like decrease, while when the number average molecular weight exceeds 20,000, the permeability to the base material is deteriorated, and the blocking resistance is deteriorated.

(3) Polyurethane resin: Examples of the polyurethane resin include dimethylolpropionic acid and, if necessary, a polyol (alkoxypolyalkylene glycol, for example, ethylene glycol, propylene glycol, methoxypolymethylene ether). Terglyco-
Methoxypolyethylene etherglycol, ethoxypolyethyleneetherglycol, ethoxypolybutyleneetherglycol, etc.) and a polyisocyanate compound. Examples of the polyisocyanate compound include tetramethylene diisocyanate
Aliphatic diisocyanates such as hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, and isophorone diisocyanate; 4.4'-methylene bis (cyclohexyl isocyanate), isophorone diisocyanate Alicyclic diisocyanates such as neat; xylylene diisocyanate; tolylene diisocyanate;
Aromatic diisocyanates such as diphenylmethane diisocyanate and polyphenylmethane diisocyanate (hereinafter referred to as polymeric MDI); and isocyanurates thereof
And similar compounds such as pentamer and burette, and these can be used alone or in combination of two or more.

(4) Epoxy resin: As the epoxy resin, for example, a conventionally known epoxy resin having at least one epoxy group in one molecule [for example, a radical polymerizable monomer containing an epoxy group (eg, ,
(3,4-epoxycyclohexylmethyl (meth) acrylate), glycidyl (meth) acrylate, and the like, a single radical polymer, and the monomer and another radical polymerizable monomer (for example, having 1 to 2 carbon atoms of (meth) acrylic acid)
4, an alkyl or cycloalkyl ester, styrene, etc.), Eporide GT300 (trade name, manufactured by Daicel Chemical Industries, Ltd., trifunctional alicyclic epoxy resin), Eporide GT400 (Daicel Chemical Industries, Ltd.)
Company name, trade name, 4-functional alicyclic epoxy resin), EHPE
(Trade name, trifunctional alicyclic epoxy resin, manufactured by Daicel Chemical Industries, Ltd.), bisphenol-type epoxy resin, novolak-type epoxy resin, ε-caprolactam-modified bisphenol-type epoxy resin, polyvinylcyclohexene diepoxide, etc.] Examples thereof include those obtained by denaturation with an acid. Examples of the polycarboxylic acid include a polycarboxylic acid resin (eg, an acrylic resin and a polyester resin) and a polycarboxylic acid compound (eg, adipic acid, sebacic acid, phthalic acid, etc.).

The carboxyl group of the epoxy resin has a resin acid value of about 10 to 200 mgKOH / g, preferably about 20 to 150 mgKOH / g. When the acid value is below the lower limit, the permeability to the substrate is poor, and the performance such as blocking resistance and efflorescence resistance deteriorates. On the other hand, when the acid value exceeds the upper limit, the performance such as the water resistance of the coating film deteriorates. There are drawbacks.

The epoxy resin has a number average molecular weight of about 50.
The range of 0 to 20,000, particularly 700 to 10,000 is preferred. When the number average molecular weight is less than about 500, the water resistance and the like decrease, while when the number average molecular weight exceeds 20,000, the permeability to the base material is deteriorated, and the blocking resistance is deteriorated.

The above-mentioned water-soluble resin can contain a hydroxyl group. The hydroxyl group forms a cross-linked coating film with a cross-linking agent such as a melamine resin, and exhibits excellent properties such as anti-blocking properties, efflorescence resistance, and water resistance. The content of the hydroxyl group is about 2
0-200 mgKOH / g, preferably about 30-150
It is in the range of mgKOH / g.

In the above-mentioned water-soluble resin solution (II), the above-mentioned vinyl resin solution (1) exhibiting excellent effects of excellent water resistance and efflorescence resistance, and further as other monomer components constituting the resin An aqueous solution in which an amide monomer is used and the carboxyl group is neutralized with a basic compound and then made water-soluble is particularly preferable.

In the above water-soluble resin solution (II), a crosslinking agent for a carbonyl group-containing resin or a hydroxyl group-containing resin (a polyhydrazide compound crosslinking agent for a carbonyl group-containing resin, an amino resin crosslinking agent for a hydroxyl group-containing resin) ,
A crosslinked coating film can be formed by blending a blocked polyisocyanate crosslinking agent.

Examples of the amino resin include methylolated amino resins obtained by reacting an aldehyde with an amino component such as melamine, urea, benzoguanamine, acetoguanamine, steroganamin, spiroguanamine and dicyandiamide. Aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like. In addition, those obtained by etherifying the methylolated amino resin with an appropriate alcohol can also be used. Examples of the alcohol used for the etherification include methyl alcohol, ethyl alcohol, and n.
-Propyl alcohol, i-propyl alcohol, n-
Butyl alcohol, i-butyl alcohol, 2-ethylbutanol, 2-ethylhexanol and the like. As the amino resin, particularly a melamine resin, furthermore, a part or all of the methylol group of the amino resin, for example,
It is preferable to use a low-molecular-weight alkoxymelamine resin which has been etherified with a lower alcohol such as methyl alcohol, ethyl alcohol, or propyl alcohol and made water-soluble. Specifically, for example, a melamine in which the methylol group is methyletherified on average 3 or more per triazine nucleus or a melamine resin in which a part of the methoxy group is substituted with an alcohol having 2 or more carbon atoms, and Melamine resins having an average degree of condensation of about 2 or less and a mononuclear ratio of about 50% by weight or more are preferred.

As the low molecular weight alkoxymelamine, commercially available products such as Cymel 303 and Cymel 32
5, Cymel 327, Cymel 350, Cymel 370
[All manufactured by Mitsui Chemicals, Inc.], Nikarac MS17, Nikarac MS15 [All manufactured by Sanwa Chemical Co., Ltd.], Rezmin 741 [Monsanto Co., Ltd.], Sumimar M-55 [Sumitomo Chemical], Sumimar M- 30W [Sumitomo Chemical Co., Ltd.]
Methyl etherified melamine, Cymel 202, Cymel 235, Cymel 238, Cymel 254, Cymel 272, Cymel 1130 (all manufactured by Mitsui Chemicals, Inc.), Niclac MX-485, Niclac MX-48
7 [all manufactured by Sanwa Chemical Co., Ltd.] and mixed ether melamines such as Resin 755 [manufactured by Monsanto].

The mixing ratio of the amino resin (in terms of solid content)
The amount is about 0 to 50 parts by weight, preferably 1 to 45 parts by weight, based on 100 parts by weight of the water-soluble resin solids.

The blocked polyisocyanate compound may be a conventionally known aqueous or organic solvent-based blocked polyisocyanate compound containing two or more, preferably two to four, isocyanate groups blocked by a blocking agent in one molecule. Can be used. As the aqueous blocked polyisocyanate compound, the compound itself has a water-solubility or water-dispersibility, or a surfactant can be added or a hydrophilic protective colloid can be formed even if the compound itself has no water-solubility or water-dispersibility. A water-based material can be used. As the water-soluble or water-dispersible substance, for example, a blocking agent may be used for a reaction product containing a free isocyanate group at a terminal obtained by reacting an alkoxypolyalkylene glycol with a polyisocyanate compound. Are blended.

Examples of the alkoxypolyalkylene glycol include methoxypolymethylene ether glycol, methoxypolyethylene ether glycol, ethoxypolyethylene ether glycol, ethoxypolybutylene ether glycol and the like. Having a molecular weight of 1
Those having a range of from 00 to 4,000, preferably from 400 to 2,000 can be used.

The organic solvent-based blocked polyisocyanate compound is one that is itself dissolved or dispersed in a hydrophilic or hydrophobic organic solvent. Examples of the hydrophilic organic solvent include alcohols such as methanol, ethanol, n-propanol and isopropanol, and ethers such as cellosolve, methyl cellosolve, butyl cellosolve and carbitol acetate. Examples of the hydrophobic organic solvent include hydrocarbons such as toluene and xylene, ketones such as methyl isobutyl ketone, 2-hexanone, isophorone and cyclohexanone, methyl acetate, ethyl acetate, and propyl acetate.
Examples thereof include esters such as butyl acetate and alcohols such as butanol and hexanol.

The proportion of the blocked polyisocyanate compound is about 0 to 100 parts by weight of the aqueous resin (solid content) in terms of solid content.
It is in the range of 50 parts by weight, preferably about 10 to 30 parts by weight.

The above-mentioned polyhydrazide compound is contained in one molecule.
Hydrazide group (-CO-NH-NH _Two) Contains two or more
Compound that reacts with the above carbonyl group to form a crosslinked structure
It is.

Typical specific examples of the polyhydrazide compound include dihydrazide such as carbodihydrazide, oxalic dihydrazide, malonic dihydrazide, succinic dihydrazide, glutaric dihydrazide, adipic dihydrazide, sebacic dihydrazide, and eicoic diacid. C2-40 aliphatic carboxylic acid dihydrazide such as dihydrazide, phthalic acid dihydrazide, terephthalic acid dihydrazide, isophthalic acid dihydrazide, pyromellitic acid dihydrazide, pyromellitic acid trihydrazide, aromatic polyhydrazide such as pyromellitic acid tetrahydrazide,
And maleic dihydrazide, fumaric dihydrazide,
Other polyhydrazides such as monoolefinically unsaturated dihydrazide such as itaconic acid dihydrazide, bissemicarbazide, polyacrylic acid polyhydrazide, and 1,3-bis (hydradi / carboethyl) -5-isopropylhydantoin are exemplified.

The compounding ratio of the polyhydrazide compound is in the range of 0 to 2 equivalents, preferably 0 to 1 equivalent based on the carbonyl group of the water-soluble resin.

In addition to the above, the following colloidal silica,
Additives such as a compound containing a hydrolyzable silane group and / or a hydroxysilane group can be blended.

Colloidal silica is a dispersion in water containing SiO ₂ as a basic unit, and has a particle diameter of 4 to 100 nm. The colloidal silica has a pH of about 7.
One or more can be used. Specifically, for example, Snowtex 20, Snowtex C, Snowtex N
(These are Nissan Chemical Industries, trade names).

The mixing ratio of the colloidal silica is in the range of 0 to 400 parts by weight, preferably 0 to 100 parts by weight in terms of solids, based on 100 parts by weight of the total solids of the water-soluble resin (II). By incorporating such colloidal silica, blocking resistance can be imparted to the film of the sealer.

The compound containing a hydrolyzable silane group and / or a hydroxysilane group contains at least two hydrolyzable silane groups or hydroxysilane groups per molecule, or at least one or more hydrolyzable silane groups and hydroxysilane groups. Is a silane compound. Representative specific examples include, for example, dimethoxydimethylsilane, dimethoxydiethylsilane, dimethoxydiphenylsilane, diethoxydimethylsilane, diethoxydiethylsilane, diethoxydiphenylsilane, dipropoxydimethylsilane,
Dialkoxysilanes such as dipropoxydiethylsilane, dipropoxydipropylsilane, dipropoxydiphenylsilane, dibutoxydimethylsilane, dibutoxydiethylsilane, dibutoxydibutylsilane, dibutoxydiphenylsilane; trimethoxymethylsilane, trimethoxyethyl Silane, trimethoxypropylsilane, trimethoxybutylsilane, trimethoxyphenylsilane, triethoxymethylsilane, triethoxyethylsilane, triethoxybutylsilane, triethoxyphenylsilane, tripropoxymethylsilane, tripropoxypropylsilane, tripropoxyphenyl Trialkoxysilanes such as silane and tributoxyphenylsilane; tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane Tetraalkoxysilanes such as tetrabutoxysilane, dimethoxydiethoxysilane and tetraphenoxysilane; hydroxysilanes such as trimethylsilanol, tripropylsilanol, tributylsilanol, triheptylsilanol and triphenylsilanol; γ-N- (2-amino Aminosilanes such as ethyl) aminopropyltrimethoxysilane, p- (N, N-dimethylamino) phenyltriethoxysilane and 3-aminopropylmethyldiethoxysilane; vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (methoxyethoxy) ) Vinylsilanes such as silane, γ-methacryloyloxypropyltrimethoxysilane and 2-styrylethyltrimethoxysilane;
Epoxysilanes such as (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane; γ-mercaptopropyltrimethoxysilane, γ-mercapto Propylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, γ
-Other silanes such as chloropropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, and trimethylchlorosilane; condensates of these silane compounds; and radical (co) polymers of vinylsilanes.

The compounding ratio of the compound containing a hydrolyzable silane group and / or hydroxysilane group is determined based on the water-soluble resin (I
The solid content is in the range of about 0 to 20 parts by weight, preferably about 0 to 15 parts by weight, based on 100 parts by weight of the total solid content of I).

In the aqueous sealer of the present invention, the mixing ratio of the synthetic resin emulsion (I) and the water-soluble resin solution (II) is as follows: the synthetic resin emulsion (I) “the resin solid content (excluding the crosslinking agent and the added resin)”. 100 to 100 parts by weight of the water-soluble resin solution (II) “100 to 10,000 parts by weight, especially 200
The range of -5000 parts by weight is preferred. Compounding ratio is 100
If the amount is less than parts by weight, blocking resistance and the like are reduced, while
If the amount exceeds 10,000 parts by weight, the efflorescence resistance and the adhesion of the overcoat during long-term exposure are undesirably reduced.

The aqueous sealer may further contain, if necessary, a coloring pigment, an extender pigment, a filler, a curing catalyst,
A fluidity adjusting agent, an antifoaming agent, an organic solvent and the like can be blended.

The solid content of the aqueous sealer is 1 to 40% by weight,
It is preferably used at a concentration of 3 to 20% by weight. When the solid content is less than 1% by weight, the number of coatings increases to secure the coating film thickness, so that the coating workability deteriorates. On the other hand, when the solids content exceeds 40% by weight, the permeability to the substrate is poor, so that the blocking resistance is poor. Become.

The aqueous sealer of the present invention can be used for any substrate,
For example, it can be applied to inorganic ceramic building materials, paper, metals such as iron and aluminum, wood, slates, concrete, bricks, asbestos base materials and the like.

A coating method in which the inorganic porous substrate of the aqueous sealer of the present invention is used as an inline sealer including an autoclave step will be described below.

The coating method can be carried out by applying an inline sealer to the surface of the inorganic porous base material, drying the coated material, curing it in an autoclave, and then applying a top coat.

As the inorganic porous substrate, for example, an inorganic porous substrate mainly composed of an inorganic material such as cement, calcium silicate or gypsum (for example, calcium silicate plate, asbestos cement plate, wood chip cement plate, Building materials such as pulp cement board and lightweight cellular concrete board, structural materials,
Civil engineering materials or those used as industrial materials).

The coating amount of the inline sealer (in terms of solid content) is 0.1 to 30 g / m ² , preferably 0.5 to ² g / m ² .
The range is 0 g / m ² . When the coating amount is less than 0.1 g / m ^{2, the} efflorescence resistance is reduced, while 30 g / m 2
^If it exceeds ² , the blocking resistance and the like are undesirably reduced.

The coating method of the in-line sealer is not particularly limited, and a conventionally known coating method, for example, a roller,
It can be performed by a method such as brushing, spraying, dipping, or a flow coater (such as a curtain flow coater).

The drying of the in-line sealer may be performed, for example, when the base material is heated by primary curing or the like.
It is preferable to perform drying by remaining heat (about 60 ° C.) of the base material by the next curing. When the substrate is not preheated, it varies depending on the type of the substrate, but usually about 20 to 200.
It is preferable to perform drying at a temperature of about 3 seconds to 60 minutes. In the drying, in particular, drying by the residual heat of the base material is performed in such a manner that the sealer is applied in a state where the base material is warm, so that the permeability to the base material is excellent, and thus the cross-linking reaches the inside of the base material. In addition, there is an advantage that performance such as blocking resistance is excellent.

The autoclave curing can be carried out under the conditions used for ceramic substrates without any particular limitation. Usually, the reaction is carried out at about 160 to 170 ° C., about 8 to 9 kgf / cm ² for about 4 to 8 hours in the presence of steam.

[0084]

Next, the present invention will be described in detail with reference to examples. In the examples and comparative examples, parts and% are based on weight.

Example of Production of Core / Shell Emulsion (a) 10 parts of a monomer component (Note 1), 0.2 part of sodium lauryl sulfate, 80 parts of water and 7.5 parts of a 2% aqueous solution of ammonium persulfate are uniformly mixed. Create a pre-emulsion,
The mixture was heated to 78 ° C. and polymerized for 1 hour to obtain an emulsion (seed). At the same temperature, 90 parts of the monomer component (Note 1), 1.8 parts of sodium lauryl sulfate,
A mixture consisting of 45 parts of water and 0.15 part of ammonium persulfate was added dropwise over 3 hours, and the mixture was left at the same temperature for 1 hour to prepare a core (glass transition temperature: 18 ° C.).
Next, a mixture consisting of 100 parts of a monomer component (Note 2) for a shell part (note 2) (glass transition temperature: 50 ° C.), 1.2 parts of ammonium persulfate and 68 parts of water was required for 3 hours. After flowing, it was kept at 83 ° C. for 2 hours. Then, after cooling to room temperature, ammonia was added to adjust the pH to 8.
And filtered through a 200 mesh filter cloth to obtain a core-shell emulsion. The total glass transition temperature of the core part and the shell part is 23.9 ° C. Solid content 50
%. Average particle size about 100 nm.

(Note 1) Monomer component: methyl methacrylate / n-butyl acrylate / methacrylic acid = 58.6 / 4
0.4 / 1.0 (weight ratio) (Note 2) Monomer component: methyl methacrylate / n-butyl acrylate / methacrylic acid = 76/23 / 1.0 (weight ratio) Core / shell emulsion (b) ) Production Example A pre-emulsion was prepared by uniformly mixing 10 parts of a monomer component (Note 3), 0.2 part of sodium lauryl sulfate, 80 parts of water and 7.5 parts of a 2% aqueous solution of ammonium persulfate.
The mixture was heated to 78 ° C. and polymerized for 1 hour to obtain an emulsion (seed). At the same temperature, 90 parts of the monomer component (Note 3), 1.8 parts of sodium lauryl sulfate,
A mixture consisting of 45 parts of water and 0.15 part of ammonium persulfate is added dropwise over 3 hours, and left at the same temperature for 1 hour to prepare a core (glass transition temperature: 15 ° C.).
Next, 100 parts of a monomer component (Note 4) for a shell part (note 4) (glass transition temperature: 60 ° C.), 1.2 parts of ammonium persulfate and 68 parts of water were allowed to flow into this in 3 hours. After that, the mixture was kept at 83 ° C. for 2 hours. Then, after cooling to room temperature, ammonia was added to adjust the pH to 8, and 2
The mixture was filtered through a 00 mesh filter cloth to obtain a core-shell emulsion. The total glass transition temperature of the core part and the shell part is 23 ° C. Solid content 50%. Average particle size about 1
00 nm.

(Note 3) Monomer component: methyl methacrylate / n-butyl acrylate / methacrylic acid = 58.6 / 4
2.2 / 1.0 (weight ratio) (Note 4) Monomer component: methyl methacrylate / n-butyl acrylate / methacrylic acid = 80.7 / 18.3 / 1.
0 (weight ratio) Production example of core-shell emulsion (c) In the production example of core-shell emulsion (a), methyl methacrylate / n-butyl acrylate / methacrylic acid = 66/23 /
An emulsion was produced in the same manner as in the core-shell emulsion (a) except that 1.0 / 2-hydroxyethyl methacrylate 10 (weight ratio) was used. The glass transition temperature of the shell part of the emulsion was 40 ° C.

The emulsion has a solid content of 50%.
%. The average particle size was about 100 nm.

Production Example of Water-Soluble Resin Solution (a) 300 equipped with a thermometer, stirrer, cooler and dropping funnel
100 parts of propylene glycol monomethyl ether was placed in a four-neck flask of cc, and the temperature was raised to 80 to 90 ° C., and 30 parts of methyl methacrylate, 30 parts of N-butyl acrylate, 13 parts of styrene, N-n-butoxymethyl acrylamide 10 , 10 parts of 2-hydroxyethyl acrylate, 7 parts of acrylic acid and 1 part of azobisisobutyronitrile were added dropwise over 3 hours. After aging for 1 hour at the same temperature, azobisbutyronitrile 1
Parts were added as an additional catalyst, and the mixture was aged for 2 hours to obtain an aqueous copolymer organic solvent solution having a resin solid content of 50% by weight, a resin acid value of 56 KOH mg / g, and a number average molecular weight of the resin of about 6,000.

Next, 0.9 equivalent of a neutralizing agent of triethylamine was added to the solution, and the mixture was stirred and mixed.
Water-soluble resin solution (average particle diameter of 40 nm or less) was produced by gradually mixing and stirring deionized water until the weight% was reached.

Production Examples of Examples 1 to 5 The aqueous sealers of Examples 1 to 5 were produced with the formulations shown in Table 1.

Comparative Examples 1 and 2 The aqueous sealers of Comparative Examples 1 and 2 were produced with the formulations shown in Table 1.

Table 1 shows the test results of the coating properties of the aqueous sealers obtained in Examples and Comparative Examples.

[0094]

[Table 1]

In Table 1, the test was conducted as follows.

Efflorescence resistance: The aqueous sealer obtained above was treated with a cement paste (cement / petroleum / water =
A 100/4/35 weight ratio blend was processed into a flat plate and left for 30 minutes.)
² and spray-dried, and then dried by autoclaving (160 to 170 ° C, about 8 to 9 kgf /
cm ² for about 6 hours in the presence of water vapor), and the coating film of the sealer was observed. The evaluation was performed according to the following criteria. ◎ indicates no whitening at all, は indicates slight whitening but no practical problem, Δ indicates poor whitening, and × indicates significant whitening.

Blocking resistance: An aqueous sealer was spray-coated on ^two slate plates so that the coating amount was 50 g / m ^2, and dried at 100 ° C. for 5 minutes. Is increased to 400 g / cm ^2, and heated at 170 ° C. for 1 hour.
After cooling to room temperature, the ease of peeling between the two slate plates was examined. The evaluation was performed according to the following criteria. ◎: good without any adhesion, は: slightly adhered but capable of peeling with light force, も の: peelable without strong force, ×
Is difficult to peel off.

Water resistance: The aqueous sealer obtained above was spray-coated on the surface of the slate plate so as to have a coating amount of 50 g / m ² , left to dry, and then cured in an autoclave (160 to 170 ° C., about 8 to 80 ° C.). 9 kgf / cm ² , about 6 hours in the presence of water vapor), and then apply a top coat (Ales Aqua Gloss, manufactured by Kansai Paint Co., Ltd., trade name, water-based emulsion paint) to a dry film thickness of about 30 μm. Spray coating was performed and drying was performed at 100 ° C. for 20 minutes to prepare a test coated substrate. Put this in tap water at 20 ° C.
After immersion for 0 days, the presence or absence of coating film abnormalities such as cracking, peeling, and blistering of the top coating film was observed. ○: No abnormality, Δ: Swelling observed, ×: Cracking, peeling observed.

Initial top coat adhesion: The aqueous sealer obtained above was spray-coated on the surface of the slate plate so as to have a coating amount of 50 g / m ² , dried by standing, and then cured in an autoclave (at 160 to 170 ° C., approx. 8-9Kgf / c
m ² , about 6 hours in the presence of water vapor), and then a top coating (Ales Aqua Gloss, manufactured by Kansai Paint Co., Ltd.)
(Product name, water-based emulsion paint)
m, and dried at 100 ° C. for 20 minutes to prepare a test coated substrate.

The test plate was subjected to JIS K-5400.
5.2 (1990) 1 mm in accordance with the grid-tape method
One hundred squares each having a size of 1 mm were formed, and the degree of peeling of the squares when a tape was adhered to the surface and peeled was tested.
◎ indicates no peeling, ○ indicates a peeling area of 0.1 to 1%, △ indicates a peeling area of 1.1 to 10%, and x indicates a peeling area greater than that.

Accelerated weather resistance: After the test plate used in the above-mentioned adhesion test was exposed to a sunshine weather meter for 3000 hours, the above-mentioned adhesion test was carried out.

[0102]

The water-based sealer of the present invention exerts excellent effects on the coating properties such as blocking resistance and water resistance.

In the step of applying an in-line sealer to the surface of a ceramic porous substrate, drying and applying an in-line sealer in the autoclave curing step, a primer which is a conventionally known acrylic emulsion is used as the in-line sealer. Due to insufficient permeation into the porous substrate, there are disadvantages that the blocking resistance of the substrate is inferior, and the film performance such as water resistance of the film is inferior. In addition, when a ceramic substrate such as a cement molded product is treated under severe conditions in an autoclave, the coating is hydrolyzed by an alkaline substance eluted from the inside of the molded product, and the performance such as water resistance and blocking resistance deteriorates. .

In the case where a conventionally known water-soluble resin solution is used as an in-line sealer, the film thickness of the sealer coating film existing on the surface of the porous base material becomes thin, so that the adhesion may be reduced by a long-term exposure test or the like. There are drawbacks.

On the other hand, the aqueous sealer of the present invention
It is presumed that the composition having the above-described structure exhibits remarkable effects such as excellent permeability to the ceramic-based porous base material and excellent coating performance such as adhesion to the top coat.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C09D 133/26 C09D 133/26 F term (reference) 4D075 AA01 BB24Y BB60Y CA32 CA38 DB14 DC02 EA06 EA13 EB15 EB19 EB22 EB38 EB39 EB43 EC35 EC37 4G028 CA01 CB04 CB05 CB06 CB08 CC01 CC03 CD02 4J038 CA021 CA022 CA041 CA042 CA111 CA112 CC011 CC012 CC021 CC022 CC041 CC042 CD021 CD022 CD091 CD092 CE051 CE052 CF021 CF022 CF031 CF032 CG CG CG CG CG CG CG CG CG CG CG CG CG DB002 DB061 DB062 DB071 DB072 DB221 DB222 DD061 DD062 DD081 DD082 DD121 DD122 DG001 DG002 DL001 DL002 MA03 MA10 MA13 MA14 NA03 NA04 NA10 PA19 PB12 PC01 PC04

Claims (8)

[Claims] 1. An aqueous sealer suitable for ceramic substrates, comprising an aqueous resin mixture of a synthetic resin emulsion (I) and a water-soluble resin solution (II) as a base resin component. 2. The synthetic resin emulsion (I) has a core having a glass transition temperature of −20 to 50 ° C., a shell having a glass transition temperature higher than 50 ° C., and a total glass transition temperature of both portions of 30 ° C. or lower. The aqueous sealer according to claim 1, which is a core-shell emulsion. 3. The synthetic resin emulsion (I) contains a hydroxyl group in a shell part.
2. The aqueous sealer according to item 1. 4. The aqueous sealer according to claim 1, wherein the water-soluble resin solution (II) is water-soluble by a carboxyl group and / or a carbonyl group. 5. The aqueous sealer according to claim 1, wherein the water-soluble resin solution (II) is a thermosetting type. 6. The aqueous sealer according to claim 1, wherein the water-soluble resin solution (II) is a vinyl-based water-soluble resin solution. 7. The water-soluble resin solution (II) contains a (meth) acrylamide monomer or a derivative thereof as a monomer component constituting the vinyl-based water-soluble resin solution. 7. The aqueous sealer according to 6. 8. The process according to claim 1, wherein the inline sealer is applied to a surface of the inorganic porous base material, dried and then cured in a step including autoclave curing. An inline coating method for ceramic substrates, characterized by being an aqueous sealer.