JP5318708B2 - Emulsion composition and waterproofing coating film using the same - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an emulsion composition and a waterproof coating material using the same, and more specifically, civil engineering / architecture such as a roof of a building such as a flat roof, a veranda of a building, a wall, a balcony, a bathroom, an outer surface of a freezer warehouse, etc. In the field, the present invention relates to an emulsion composition used in waterproof coating technology, and a polymer cement-based waterproof coating material using the same.

  Conventionally, it is well known that synthetic polymer emulsions such as acrylic emulsions and vinyl acetate emulsions are mixed with cement and used as waterproofing materials. However, because these emulsion compositions are not sufficiently dispersible in cement, cement hardening may occur due to internal factors such as shrinkage due to hardening, or external factors such as temperature change, freezing and thawing, and movement of the substrate. There was a problem that checking (cracks) was likely to occur in the process. In particular, the occurrence of this checking is a main factor that impairs the performance as a waterproof material, and thus improvement has been eagerly desired.

  Therefore, in order to suppress the occurrence of checking of the cured cement, it has been proposed to use a polymer cement composition containing an alumina cement, an emulsion and a wax suspension and having a tack load of 500 gf or less (see Patent Document 1). .

Moreover, in order to give the performance as a waterproof film, the waterproof improvement by addition of fats and oils is proposed (refer patent document 2).
Japanese Patent Laid-Open No. 2005-220009 Japanese Patent Laid-Open No. 5-295862

  However, in the above-mentioned Patent Document 1, although there is an effect in suppressing the occurrence of checking at the time of drying, the viscosity is high (usually, the viscosity at BH 10 rpm is 5000 mPa · s or more), the coatability is limited, and the coating is limited. Since it is limited to trowel coating, the workability is low, and there are disadvantages that leveling properties cannot be imparted to the coating film surface. On the other hand, when the viscosity is lowered, the coating property is improved, but when a thick coating of 1 mm or more is performed, there is a problem that the coating film is checked during drying. Moreover, in the said patent document 2, since the main ingredient is an asphalt type emulsion composition and an odor generate | occur | produces at the time of an operation | work, there also existed a problem from an environmental viewpoint.

  The present invention has been made in view of such circumstances, and has low viscosity and excellent coating properties, and can suppress the occurrence of coating film checking during coating (excellent checking resistance). An object of the present invention is to provide an emulsion composition and a waterproof coating material using the same.

  The inventors have conducted research to obtain an emulsion composition that is low in viscosity and excellent in coating properties, and that can suppress the occurrence of coating coating checking during coating (excellent checking resistance). In the process of accumulating, we first focused on the water reducing agent. The water reducing agent is used as an additive for improving the fluidity of the cement by reducing the amount of water in the polymer cement composition, and the fluidity can be improved with a small amount of addition. . As a result of repeated experiments on the content of the water reducing agent used for the purpose of improving fluidity, the inventors have increased the amount of the water reducing agent with respect to the normal usage amount, that is, the water reducing agent. Is contained in an amount of 5 to 40 parts by weight with respect to 100 parts by weight of cement, since the setting speed of cement in the coating film at the time of enforcement can be delayed and aggregation of the cement can be prevented. The internal stress distribution was found to be uniform. As a result, when an emulsion composition containing an acrylic emulsion, cement, and a predetermined amount of water reducing agent larger than the conventional amount used is used, the viscosity is low and the coatability is good, and the viscosity is low. It has been found that the occurrence of checking can be suppressed even during coating (excellent checking resistance), and the present invention has been achieved.

That is, the present invention is an emulsion composition comprising an acrylic emulsion, cement , a water reducing agent and a surface modifier, and contains 5 to 40 parts by weight of the water reducing agent with respect to 100 parts by weight of cement. In addition, a first gist is an emulsion composition in which the surface modifier is a polyether compound containing at least one of ethylene oxide and propylene oxide .

  Moreover, this invention makes the coating-film waterproof material containing the said emulsion composition make a 2nd summary.

As described above, the emulsion composition of the present invention contains 5 to 40 parts by weight of a water reducing agent with respect to 100 parts by weight of cement , and also contains at least one of ethylene oxide and propylene oxide as a surface modifier. due to the chromatic ether compound, together with a coating of a low viscosity is good, the rate of coagulation of the cement in the coating film is delayed during enforcement, it is possible to prevent aggregation of cement, dry The coating surface and the internal stress are uniformly dispersed, and the effect of suppressing the occurrence of checking even in low-viscosity coating ( particularly excellent in resistance to checking) can be obtained. In addition, since the emulsion composition of the present invention has a low viscosity, it can be applied by brushing or roller coating, and the workability is improved and the leveling property of the coating film surface can be obtained. Furthermore, since the emulsion composition of the present invention is excellent in drying properties, it can be applied in summer, and even when thick coating of 1 mm or more, which has been difficult in the past, is suppressed, the occurrence of checking is suppressed. Can do.

  And the elongation at the time of the low temperature of a coating film improves that the glass transition temperature of acrylic resin which comprises acrylic emulsion is -20--40 degreeC.

  In addition, when the acrylic resin constituting the acrylic emulsion is obtained by emulsion polymerization of an ethylenically unsaturated monomer in the presence of a reactive surfactant, the miscibility with cement becomes excellent. .

  Further, when at least one selected from the group consisting of a naphthalene compound, a melamine compound, a lignin compound, and a polycarboxylic acid compound is used as the attenuating agent, the check resistance is further improved.

  Moreover, when the surface modifier is contained in an amount of 1 to 20 parts by weight with respect to 100 parts by weight of cement, the balance between the check resistance and the coating property becomes better.

  Furthermore, when oils and fats are used in combination, the water resistance of the coating film is improved.

  When the oil is soybean oil, the water resistance of the coating film is further improved.

  When 1 to 50 parts by weight of fats and oils are contained with respect to 100 parts by weight of the acrylic resin in the acrylic emulsion, the balance between water resistance and coating property becomes better.

  When the emulsion composition of the present invention is used as a waterproof coating material, excellent water resistance and check resistance can be obtained.

  Since the waterproof coating material of the present invention contains the above-mentioned special emulsion composition, it is excellent in water resistance and checking resistance, and is useful, for example, in the field of civil engineering and construction.

  Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to this embodiment.

The emulsion composition of the present invention can be obtained using an acrylic emulsion, cement , water reducing agent and surface modifier . In the present invention, along with containing 5 to 40 parts by weight with respect to water reducing agent is 100 parts by weight of cement, as a surface modifier, comprising have a polyether compound containing at least one of ethylene oxide and propylene oxide This is the biggest feature. First, this acrylic emulsion will be described.

《Acrylic emulsion》
The acrylic resin (W) constituting the acrylic emulsion is preferably, for example, a homopolymer or copolymer of an ethylenically unsaturated monomer (M), and more preferably an ethylenically unsaturated monomer. Among the bodies (M), an acrylic copolymer that is mainly composed of (meth) acrylic acid alkyl ester and copolymerized with other ethylenically unsaturated monomers is preferable. Hereinafter, the ethylenically unsaturated monomer (M) which is a polymerization component forming the acrylic resin (W) will be described in detail.

<Ethylenically unsaturated monomer (M)>
Examples of the ethylenically unsaturated monomer (M) that forms the acrylic resin (W) include the following (a) to (m). These may be used alone or in combination of two or more.
(A) Alkyl ester of (meth) acrylic acid.
(B) Aromatic ethylenically unsaturated monomer.
(C) A hydroxyl group-containing ethylenically unsaturated monomer.
(D) A carboxyl group-containing ethylenically unsaturated monomer.
(E) An epoxy group-containing ethylenically unsaturated monomer.
(F) A methylol group-containing ethylenically unsaturated monomer.
(G) An alkoxyalkyl group-containing ethylenically unsaturated monomer.
(H) A cyano group-containing ethylenically unsaturated monomer.
(I) An ethylenically unsaturated monomer having two or more radically polymerizable double bonds.
(J) An ethylenically unsaturated monomer having an amino group.
(K) An ethylenically unsaturated monomer having a sulfonic acid group.
(L) An ethylenically unsaturated monomer having a phosphate group.
(M) An ethylenically unsaturated monomer having an amide group.

  In addition, as said acrylic resin (W) in this invention, in addition to said (a)-(m), vinyl acetate, vinyl propionate, vinyl versatic acid, vinyl pyrrolidone, methyl vinyl ketone, butadiene, ethylene, propylene, Monomers such as vinyl chloride and vinylidene chloride can be appropriately used as desired.

  Examples of the (meth) acrylic acid alkyl ester (a) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, and isobutyl (meth). Aliphatic (meth) acrylates such as acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, preferably an alkyl group having 1 to 20 carbon atoms Aliphatic (meth) acrylates, aromatic (meth) acrylates such as benzyl (meth) acrylate, phenyl (meth) acrylate, and the like can be used, and these can be used alone or in combination of two or more. Among these, Preferably, it is an aliphatic (meth) acrylate having 1 to 10 carbon atoms in the alkyl group such as butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methyl (meth) acrylate, cyclohexyl (meth) acrylate and the like. is there.

  Examples of the aromatic ethylenically unsaturated monomer (b) include styrene, vinyltoluene, α-methylstyrene and the like, and these are used alone or in combination of two or more. Of these, styrene is preferable.

  Examples of the hydroxyl group-containing ethylenically unsaturated monomer (c) include hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate, and polymers such as polyethylene glycol (meth) acrylate. An alkylene glycol (meth) acrylate etc. are mention | raise | lifted and these are used individually or in combination of 2 or more types. Among them, preferred are hydroxyalkyl (meth) acrylates having a C2-C4 hydroxyalkyl group and polyalkylene glycol (meth) acrylates having a C2-C4 alkylene group, and particularly preferred is hydroxyethyl (meta). ) Acrylate.

  As the carboxyl group-containing ethylenically unsaturated monomer (d), for example, (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid and the like can be used, and these can be used alone or in combination of two kinds. These are used together. Among these, (meth) acrylic acid and itaconic acid are more preferable. In the case of dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, these monoesters and monoamides may be used.

  Examples of the epoxy group-containing ethylenically unsaturated monomer (e) include glycidyl (meth) acrylate, allyl glycidyl ether, methyl glycidyl (meth) acrylate, and the like. These may be used alone or in combination of two or more. Used. Of these, glycidyl (meth) acrylate is preferred.

  Examples of the methylol group-containing ethylenically unsaturated monomer (f) include N-methylol (meth) acrylamide, dimethylol (meth) acrylamide and the like, and these are used alone or in combination of two or more.

  Examples of the alkoxyalkyl group-containing ethylenically unsaturated monomer (g) include N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, methoxyethyl (meth) acrylate, and methoxypropyl (meth). Examples include acrylates, alkoxyalkyl (meth) acrylates such as ethoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate, and polyalkylene glycol monoalkoxy (meth) acrylates such as polyethylene glycol monomethoxy (meth) acrylate. It is used alone or in combination of two or more.

  Examples of the cyano group-containing ethylenically unsaturated monomer (h) include (meth) acrylonitrile.

  Examples of the ethylenically unsaturated monomer (i) having two or more radical polymerizable double bonds include divinylbenzene, polyoxyethylene di (meth) acrylate, and polyoxypropylene di (meth). Di (meth) acrylates such as acrylate, neopentyl glycol di (meth) acrylate, butanediol di (meth) acrylate, tri (meth) acrylates such as trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, etc. These are used alone or in combination of two or more.

  Examples of the ethylenically unsaturated monomer (j) having an amino group include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, and the like. Or in combination of two or more.

  Examples of the ethylenically unsaturated monomer (k) having a sulfonic acid group include vinyl sulfonic acid and vinyl styrene sulfonic acid (salt). These may be used alone or in combination of two or more.

  Examples of the ethylenically unsaturated monomer (l) having a phosphoric acid group include vinylphosphonic acid, vinyl phosphate, acid phosphoxyethyl (meth) acrylate, acid phosphoxypropyl (meth) acrylate, and bis [(meta ) Acryloyloxyethyl] phosphate, diphenyl-2- (meth) acryloyloxyethyl phosphate, dibutyl-2- (meth) acryloyloxyethyl phosphate, dioctyl-2 (meth) acryloyloxyethyl phosphate, etc. These may be used alone or in combination of two or more.

  Examples of the ethylenically unsaturated monomer (m) having an amide group include (meth) acrylamide, N, N-methylenebis (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meta) ) Acrylamide, diacetone (meth) acrylamide, maleic acid amide, maleimide, (meth) acrylamide methanesulfonic acid (salt), (meth) acrylamide ethanesulfonic acid (salt), (meth) acrylamide propanesulfonic acid (salt), ( (Meth) acrylamidomethylethanesulfonic acid (salt), (meth) acrylamide butanesulfonic acid (salt), (meth) acrylamide methylpropanesulfonic acid (salt), (meth) acrylamide dimethylethanesulfonic acid (salt), (meth) acrylamide Pentanesulfo Acid (salt), (meth) acrylamidomethylbutanesulfonic acid (salt), (meth) acrylamidodimethylpropanesulfonic acid (salt), (meth) acrylamidoethylpropanesulfonic acid (salt), (meth) acrylamidoethylmethylethanesulfonic acid Examples thereof include compounds having a branched or straight chain alkylene group having 1 to 5 carbon atoms such as (salt) and (meth) acrylamidopropylethanesulfonic acid (salt). These may be used alone or in combination of two or more. Of these, (meth) acrylamide alkylenesulfonic acid (salt) having a branched alkylene group such as (meth) acrylamide and (meth) acrylamide methylpropanesulfonic acid (salt) is preferable. The above sulfonic acid (salt) means sulfonic acid or a salt thereof.

  In the present invention, (meth) acryloyloxy means acryloyloxy or methacryloyloxy, (meth) acrylic acid means acrylic acid or methacrylic acid, and (meth) acrylic means acrylic or methacrylic. As used herein, (meth) acrylate means acrylate or methacrylate.

  In the present invention, the main component means containing an amount exceeding 50% by weight of the whole [here, the whole ethylenically unsaturated monomer (M)], and preferably 60% by weight or more of the whole. Contains.

  The acrylic resin (W) according to the present invention is a homopolymer or copolymer of the monomer, and in this polymerization, in addition to the monomer, if necessary, a polymerization initiator, Other components such as a polymerization regulator, a surfactant, a plasticizer, and a film-forming aid can be appropriately used.

<Polymerization initiator>
As the polymerization initiator, either water-soluble or oil-soluble can be used. For example, alkyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, p-methane hydroperoxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, t-butyl cumi Ruperoxide, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 3, 3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, di-isobutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t-butylperoxyisobutyrate, etc. Organic peroxides, 2,2'-azobisisobutyronitrile, dimethyl-2,2'-azobisisobutyrate, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2 ' -Azobis (2-methylbutyronitrile), potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, ammonium (amine) salt of 4,4'-azobis-4-cyanovaleric acid, 2,2 ' -Azobis (2-methylamidooxime) dihydrochloride, 2,2'-azobis (2-methylbutanamidoxime) dihydrochloride tetrahydrate, 2,2'-azobis {2-methyl-N- [1,1- Bis (hydroxymethyl) -2-hydroxyethyl] -propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) ) -Propionamide], various redox catalysts (in this case, as an oxidizing agent, ammonium persulfate, potassium persulfate, sodium persulfate, hydrogen peroxide, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, p-methane hydroperoxide and the like, and sodium sulfite, acidic sodium sulfite, Rongalite, ascorbic acid and the like are used as the reducing agent.

  These polymerization initiators may be used alone or in combination of two or more. Among these, in terms of excellent polymerization stability, potassium persulfate, ammonium persulfate, sodium persulfate, redox catalyst (oxidizer: potassium persulfate, ammonium persulfate, sodium persulfate, reducing agent: sodium sulfite, acidic sodium sulfite, Rongalite, ascorbic acid) and the like are suitable.

  The amount of the polymerization initiator used is preferably in the range of 0.01 to 5 parts with respect to 100 parts by weight (hereinafter abbreviated as “part”) of the ethylenically unsaturated monomer (M). Furthermore, it is more preferable that it is 0.03 to 3 parts. That is, if the amount of the polymerization initiator used is too small, the polymerization rate tends to be slow, and conversely if too large, the molecular weight of the resulting copolymer is lowered, which tends to be undesirable in terms of water resistance. Because it is.

  The polymerization initiator may be added in advance to the polymerization can, may be added immediately before the start of polymerization, or may be added in the middle of polymerization as necessary. Alternatively, it may be added in advance to the monomer mixture, or may be added to an emulsion comprising the monomer mixture. In addition, when adding the polymerization initiator, the polymerization initiator may be separately dissolved in a solvent or the above monomer and added, or the dissolved polymerization initiator may be further added in an emulsified form.

<Polymerization regulator>
Moreover, a polymerization regulator can be mix | blended in the case of superposition | polymerization. Examples of the polymerization regulator include a chain transfer agent and a pH buffer.

  Examples of the chain transfer agent include alcohols such as methanol, ethanol, propanol and butanol; aldehydes such as acetaldehyde, propionaldehyde, n-butyraldehyde, furfural and benzaldehyde; n-dodecyl mercaptan, thioglycolic acid and thioglycolic acid And mercaptans such as octyl and thioglycerol. These may be used alone or in combination of two or more.

  The use of this chain transfer agent is effective in that the polymerization is performed stably, but it may reduce the degree of polymerization of the acrylic resin (W) and may decrease the elastic modulus of the resulting coating film. Therefore, specifically, the amount of the chain transfer agent used is preferably 0.01 to 1 part, more preferably 0.01 to 0 with respect to 100 parts of the whole ethylenically unsaturated monomer (M). .5 parts are preferred. This is because if the amount of the chain transfer agent used is too small, the effect as the chain transfer agent tends to be insufficient, and conversely if too large, the elastic modulus of the coating film tends to decrease.

  Examples of the pH buffering agent include soda ash (sodium carbonate), sodium bicarbonate, potassium bicarbonate, monosodium phosphate, monopotassium phosphate, disodium phosphate, trisodium phosphate, sodium acetate, acetic acid. Examples include ammonium, sodium formate, and ammonium formate. These may be used alone or in combination of two or more.

  It is preferable that the usage-amount of the said pH buffering agent is 0.01-10 parts with respect to 100 parts of ethylenically unsaturated monomers (M) whole, Furthermore, it is preferable that it is 0.1-5 parts. This is because if the amount of the pH buffer used is too small, the effect as a polymerization regulator tends to be insufficient, and conversely if too large, the reaction tends to be inhibited.

<Surfactant>
As the surfactant, a reactive surfactant is preferably used from the viewpoint of water resistance of the coating film. As said reactive surfactant, the ionic and nonionic surfactant which has radical reactivity with an ethylenically unsaturated monomer is used, for example, it represents with following General formula (1)-(11). There is a thing with a structure. These may be used alone or in combination of two or more.

[In the general formulas (1) to (11), R ₁ is an alkyl group, R ₂ is hydrogen or a methyl group, R ₃ is an alkylene group, l, m, and n are integers of 1 or more (m + n = 3) , X is hydrogen, SO ₂ NH ₄ , or SO ₃ Na. ]

  Specific examples of the surfactant include ADEKA rear soap SE-10N (anionic), ADEKA rear soap SE-20N (anionic), ADEKA rear soap SR-10 (anionic), and ADEKA rear soap SR-20 ( Anionic), ADEKA rear soap NE-10 (nonionic), ADEKA rear soap NE-20 (nonionic), ADEKA rear soap NE-30 (nonionic), ADEKA rear soap NE-40 (nonionic), ADEKA rear Soap ER-10 (nonionic), Adeka soap ER-20 (nonionic), Adeka soap ER-30 (nonionic), Adeka soap ER-40 (nonionic), Adekalia soap SDX-730 (anion) ), Adeka Soap SDX-731 (anionic), Adeka Soap PP-70 (Anio) ), Adekalya soap PP-710 (anionic) [manufactured by Asahi Denka Co., Ltd.], Eleminol JS-2 (anionic), Eleminol JS-20 (anionic), Eleminol RS-30 (anionic) [Above, manufactured by Sanyo Chemical Co., Ltd.], Latemul S-180A (anionic), Latemul S-180 (anionic), Lateml PD-104 (anionic) [above, manufactured by Kao Corporation], Aqualon BC- 05 (anionic), Aqualon BC-10 (anionic), Aqualon BC-20 (anionic), Aqualon HS-05 (anionic), Aqualon HS-10 (anionic), Aqualon HS-20 (anionic) Aqualon RN-10 (nonionic), Aqualon RN-20 (nonionic), Aqualon RN-30 (nonionic), Quarron RN-50 (nonionic), Aqualon KH-05 (anionic), Aqualon KH-10 (anionic), New Frontier S-510 (anionic) [above, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], Phosphino -Commercial products such as Ru TX (anionic) [manufactured by Toho Chemical Co., Ltd.]. These reactive surfactants are used alone or in combination of two or more.

  Examples of the surfactant other than the reactive surfactant include, for example, alkyl or alkyl allyl sulfate, alkyl or alkyl allyl sulfonate, dialkyl sulfosuccinate, sodium dodecylbenzene sulfonate, polyoxyethylene alkyl ether sodium sulfate, Anionic surfactants such as sodium alkyl sulfonate; cationic surfactants such as alkyl trimethyl ammonium chloride and alkyl benzyl ammonium chloride; polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene carboxylic acid ester, poly Nonionic surfactants such as oxyethylene glycol type and polyoxyethylene propylene glycol type; and ammonium = α-sulfonato-ω-1- (a Ryloxymethyl) alkyloxypolyoxyethylene, α-sulfo-ω- (1- (alkoxy) methyl-2- (2-propenyloxy) ethoxy-poly (oxy-1,2-ethanediyl) ammonium salt, polyoxy Examples thereof include ethylene alkylpropenyl phenyl ether, and these are used alone or in combination of two or more.

  The amount of the surfactant used is preferably 0.1 to 10 parts, more preferably 0.5 to 10 parts, particularly 0 with respect to 100 parts of the whole ethylenically unsaturated monomer (M). It is preferably in the range of 5 to 5 parts. That is, if the amount of the surfactant used is too small, the polymerization stability tends to become unstable, and conversely if too large, the average particle size of the resulting polymer or copolymer is small. This is because there is a tendency that the viscosity of the emulsion becomes too high, resulting in problems such as a decrease in workability.

<Plasticizer and film-forming aid>
Moreover, as said plasticizer, an adipate type plasticizer, a phthalic acid type plasticizer, a phosphoric acid type plasticizer etc. can be used, for example. Further, a film-forming aid having a boiling point of 260 ° C. or higher can be used.

  The amount of these plasticizers and other components such as film-forming aids can be appropriately selected as long as the object of the present invention is not impaired. For example, as the plasticizer, an ethylenically unsaturated monomer ( M) is usually 0.1 to 50 parts with respect to 100 parts as a whole, and the film forming aid is usually 0.1 to 50 parts with respect to 100 parts as a whole with the ethylenically unsaturated monomer (M).

<< Manufacture of acrylic emulsion >>
An acrylic emulsion can be obtained using the acrylic resin (W) formed from the polymerization components exemplified above as a dispersoid.

  The acrylic resin (W) is, for example, a homopolymer or copolymer obtained by subjecting the ethylenically unsaturated monomer (M) to emulsion polymerization using the polymerization initiator in the presence of a surfactant. It is manufactured by producing. In this polymerization process, an acrylic emulsion having an acrylic resin (W) as a dispersoid is generally produced.

  As the polymerization method, (1) a method in which the whole amount of ethylenically unsaturated monomer (M), surfactant, water and the like is charged and polymerized by heating, (2) water, surfactant in a polymerization can, A method in which a part of the ethylenically unsaturated monomer (M) is charged, heated and polymerized, and then the remaining ethylenically unsaturated monomer (M) is added dropwise or dividedly to continue the polymerization. (3 ) A method in which water, a surfactant or the like is charged in a polymerization can and heated, and then the whole amount of the ethylenically unsaturated monomer (M) is dropped or dividedly added for polymerization. Among these, the methods (2) and (3) are preferable in that the polymerization temperature can be easily controlled. It is also preferable to employ a multistage polymerization method, and a core-shell type emulsion obtained by multistage polymerization is desirable because it contributes to the improvement of film forming properties and mechanical properties.

  As a polymerization condition in the polymerization method shown in the above (1) to (3), for example, a temperature range of about 40 to 100 ° C. is usually appropriate as a polymerization condition in the polymerization method of the above (1). The reaction may be performed for about 1 to 8 hours later.

  Moreover, as polymerization conditions in the polymerization method of the above (2), 1 to 50% by weight of the ethylenically unsaturated monomer (M) is usually polymerized at 40 to 90 ° C. for 0.1 to 4 hours, and then the remaining For example, the ethylenically unsaturated monomer (M) may be added dropwise or dividedly over about 1 to 7 hours, and then aged for about 1 to 3 hours at the above temperature.

  And as polymerization conditions in the polymerization method of said (3), water is prepared to a superposition | polymerization can, it heats up to 40-90 degreeC, a monomer mixture is dripped or dividedly added over about 2 to 7 hours, Then, And aging at the above temperature for about 1 to 3 hours.

  In the polymerization method, the ethylenically unsaturated monomer (M) may be prepared by dissolving a surfactant (or a part of the surfactant) in the ethylenically unsaturated monomer (M) From the viewpoint of polymerization stability, it is preferable to use an O / W emulsion.

  Examples of the preparation method for preparing an O / W emulsion in advance include, for example, a method in which a surfactant is dissolved in water and then the monomer is added, and the mixture is stirred and emulsified, or a surfactant in water. And the like.

  Agitation at the time of emulsification of the emulsion can be carried out using a stirring device in which the components are mixed and a stirring blade such as a homodisper or paddle blade is attached. There is no problem as long as the temperature during emulsification is such that the mixture does not react during emulsification, and usually about 5 to 60 ° C. is appropriate.

<< Manufactured acrylic emulsion >>
In this way, an acrylic emulsion having the acrylic resin (W) as a dispersoid is obtained.

  In the acrylic emulsion, the dispersoid is the acrylic resin (W), and the dispersion medium is preferably a dispersion medium in which the acrylic resin (W) is a dispersoid. Among such dispersion media, more preferred is an aqueous medium. Here, the aqueous medium refers to water or an alcoholic solvent mainly composed of water, preferably water.

  The acrylic emulsion contains various additives such as organic pigments, inorganic pigments, water-soluble additives, pH adjusters, preservatives, antifoaming agents, and antioxidants as necessary. May be.

<Average particle size>
The average particle diameter of the acrylic resin (W) in the acrylic emulsion is preferably in the range of 100 to 500 nm, particularly 100 to 400 nm, and more preferably 150 to 300 nm. If the particle size is too small, the viscosity of the emulsion becomes too high, and the dispersibility of the emulsion tends to deteriorate when admixed with cement. Conversely, if the particle size is too large, a dense coating film is formed during coating film formation. This is because it is difficult to obtain the above-mentioned, and an unfavorable tendency in strength is observed. The measurement of the average particle diameter is based on the light scattering method.

  The average particle diameter of the acrylic resin (W) can be set within a predetermined range by appropriately adjusting the prescription used at the time of polymerization. For example, when an anionic (reactive) surfactant and a nonionic (reactive) surfactant are used in combination, a part of the surfactant is charged in a polymerization can beforehand and polymerized. ) It can be obtained by adjusting the amount and ratio of surfactant and nonionic (reactive) surfactant, the stirring speed during polymerization, and the like. However, it is not limited to these methods.

<Glass transition temperature (Tg)>
Furthermore, the glass transition temperature (Tg) of the acrylic resin (W) is in the range of 0 to −70 ° C., more preferably −10 to −60 ° C., particularly from the point that the elongation at low temperature of the coating film is improved. It is preferable that it is -20--40 degreeC. If the glass transition temperature is too high, the film-forming temperature of the coating film becomes too high, and there is a tendency that sufficient strength cannot be obtained particularly during construction in the winter. This is because there is a tendency to become.

  The glass transition temperature (Tg) of the acrylic resin (W) used was a value calculated by the Fox equation shown in the following equation (1).

1 / Tg = W ₁ / Tg ₁ + W ₂ / Tg ₂ +... + W _n / Tg _n (1)

In the above formula (1), W _n from W ₁ represents the weight fraction of each monomer using, Tg _n from Tg ₁ is the glass transition temperature (unit of a homopolymer of each monomer Indicates an absolute temperature “K”). The absolute temperature is calculated as absolute temperature “K” = Celsius temperature “° C.” + 273.15.

<Non-volatile content>
In addition, the nonvolatile content concentration (solid content concentration) of the acrylic emulsion is preferably 45% by weight or more, more preferably 45 to 75% by weight, and particularly 45 to 60% by weight. It is preferable in terms of workability. In addition, the said non-volatile content concentration means the non-volatile content concentration (solid content concentration) after drying at 105 degreeC for 1 hour.

<viscosity>
Furthermore, the viscosity of the acrylic emulsion is usually preferably 10 to 100,000 mPa · s, more preferably 10 to 5000 mPa · s, and particularly preferably 500 to 5000 mPa · s from the viewpoint of handling.

Next, in the present invention, a water reducing agent is used together with the acrylic emulsion.
<Water reducing agent>
The water reducing agent usually has a function of improving the fluidity of a cement / water mixture, but in the present invention, it has a check resistance (checking suppression action), specifically, , Naphthalene compounds, melamine compounds, lignin compounds, polycarboxylic acid compounds and the like. These may be used alone or in combination of two or more. Among these, the use of polycarboxylic acid compounds, particularly polymethacrylic acid-polyethylene glycol graft copolymers, is effective in improving checking. Further, as the water reducing agent, it is preferable to use a delayed water reducing agent from the viewpoint of setting of the cement, and the setting speed of the cement is delayed, and a good coating film can be formed without increasing the viscosity. The blending amount of the water reducing agent is 5 to 40 parts, preferably 5 to 30 parts, particularly preferably 10 to 20 parts with respect to 100 parts of cement as described below for improving the checking. This is because when the amount of the water reducing agent used is too small, the resistance to checking is inferior, and conversely, when it is too much, the film forming property is inferior.

Incidentally, the emulsion composition of the present invention, in addition to the acrylic emulsion and water-reducing agent, it is necessary to contain the surface modifier, there is no obstacle to the free for 併the oil.

<Surface modifier>
The surface modifier usually has a function of preventing checking after setting of the cement. In the present invention, the surface modifier is a polyethylene oxide compound, a polypropylene oxide compound, or the two since polyethylene propylene oxide compounds is a copolymer, it is effective for checking improvement. The blending amount is 1 to 20 parts, preferably 2 to 15 parts, and more preferably 3 to 10 parts with respect to 100 parts of cement.

<Oil and fat>
Examples of fats and oils include soybean oil, Amany oil, castor oil, corn oil, cottonseed oil, olive oil, palm oil, rapeseed oil, safflower oil, sesame oil and the like. These may be used alone or in combination of two or more. Of these, the use of soybean oil, olive oil, sesame oil, and especially soybean oil is effective for imparting waterproofness without impeding the improvement of checking. The blending amount is preferably 1 to 50 parts, more preferably 2 to 40 parts, particularly 5 to 20 parts, particularly 6 to 10 parts with respect to 100 parts of the acrylic resin in the acrylic emulsion. It is desirable to provide waterproofness.

  Furthermore, you may mix | blend other components other than the above with the emulsion composition of this invention. For example, a cold-resistant agent (for example, calcium chloride), a waterproofing agent (for example, stearic acid), a rust inhibitor (for example, phosphate), a viscosity modifier (for example, methylcellulose, hydroxyethylcellulose, polyvinyl alcohol, etc.), Dispersing agents (for example, polycarboxylic acid-based, inorganic phosphorus-based, etc.), antifoaming agents (for example, silicon-based, mineral oil-based, etc.), preservatives, reinforcing agents (for example, steel fibers, glass fibers, synthetic fibers, carbon fibers, etc.) ) Etc. These may be used alone or in combination of two or more.

  The mixing method of the acrylic emulsion and additives such as water reducing agents, surface modifiers, oils and fats is, for example, after the polymerization of the acrylic emulsion is completed, after adding additives such as water reducing agents, For example, a method of charging while stirring is used.

  Next, in the present invention, cement is used in the emulsion composition. Examples of the cement used here include ordinary Portland cement, alumina cement, early-strength Portland cement, ultra-early strength Portland cement, moderately hot Portland cement, low-heat Portland cement, sulfate-resistant Portland cement, blast furnace cement, fly ash cement, Examples thereof include silica cement, and Portland cement is preferred from the viewpoint of workability.

  The blending amount of the cement is preferably 3 to 500 parts, more preferably 30 to 350 parts, with respect to 100 parts of the acrylic resin in the acrylic emulsion.

  Moreover, as content of water, it is preferable that it is 5 to 50 weight% with respect to the whole emulsion composition, and it is more preferable that it is 10 to 30 weight%.

  In addition, the emulsion composition of the present invention may contain, if necessary, pozzolanic materials such as sand, quartz sand, cold sand, calcium carbonate, kaolin, clay, diatomaceous earth, silica fume, fly ash, blast furnace slag, natural and artificial lightweight aggregates. These various aggregates are used alone or in combination of two or more.

  In this way, an emulsion composition of the present invention, particularly an emulsion composition for a waterproofing coating film (polymer cement composition) is obtained, and this coating waterproofing composition is applied with a roller, a plastering brush or a trowel. A coating waterproofing material can be formed by spraying or spraying.

  Examples of the object on which the waterproof coating material is formed include, for example, a rooftop of a building made of mortar, concrete, iron plate, asphalt, a sloped roof, an outer wall, a fence, a veranda, a roof balcony, an external corridor, a staircase, a building Underground refills, underground joints, underground pits, miscellaneous drainage tanks, indoor or underground water tanks such as fireproof water tanks, waterproof parts around sash frames, water storage tanks, and the like.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples , reference examples, and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

In the following examples , reference examples and comparative examples , “parts” and “%” mean “parts by weight” and “% by weight”, respectively.

First, prior to Examples , Reference Examples and Comparative Examples, the following emulsion composition (without cement) was prepared.

<Preparation of emulsion composition 1 (without cement) (for reference example)>
In a container in advance, 200.0 parts of water, Surfactant a (made by ADEKA, ADEKA rear soap ER-20) 5.0 parts, Surfactant b (made by ADEKA, ADEKA rear soap SR-10S) 3.0 Parts, 0.5 parts of sodium bicarbonate, 6.0 parts of acrylonitrile, 39.0 parts of methyl methacrylate and 150.0 parts of butyl acrylate were weighed to prepare a monomer emulsified mixture (1).

  Next, in another container, 300.0 parts of water, 30.0 parts of the surfactant a, 15.0 parts of the surfactant b, 2.0 parts of sodium bicarbonate, 4.0 parts of acrylic acid, 25.0 acrylonitrile. Parts, methyl methacrylate 210.0 parts, butyl acrylate 270.0 parts, 2-ethylhexyl acrylate 270.0 parts were weighed to prepare a monomer emulsified mixture (2).

  Next, in a glass reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen inlet tube, and a dropping funnel, 300 parts of water, 0.6 part of the surfactant, and 0.15 part of the surfactant b. Was dissolved.

Then, 15% of the previously prepared monomer emulsified mixture (1) is added to the glass reaction vessel, heated to 80 ° C., heated to 80 ° C., and then heated to 10% sodium persulfate (polymerization start). Agent) 11.04 parts of the aqueous solution was added to the glass reaction vessel and allowed to react (initial polymerization). After 30 minutes, the remaining monomer emulsified mixture (1) and 6.6 parts of 10% sodium persulfate were mixed and dropped into a glass reaction vessel over 30 minutes, and polymerization was performed at 80 ° C. (First stage polymerization). After stirring for 30 minutes, a mixture of the monomer emulsified mixture (2) and 32.0 parts of 10% sodium persulfate was dropped into a glass reaction vessel over 150 minutes, and polymerization was carried out at 80 ° C. (two steps) Eye polymerization). Aging was performed for 30 minutes to complete the polymerization, and an acrylic resin (glass transition temperature: −30 ° C.) was obtained. Next, after cooling to room temperature (25 ° C.), 3.68 parts of an antiseptic [ACTICIDE (manufactured by SO Japan)], 0.96 parts of an antiseptic [Nipacide BIT20LC (manufactured by Clariant)], a neutralizing agent (caustic soda) -Da) 2.35 parts were added, and water was further added to adjust the non-volatile content (solid content) to 51.0% and pH = 7 to 10 to obtain an acrylic emulsion (average particle size: 220 nm, viscosity: 100 mPa · s). Next, 52.48 parts of a water reducing agent (polymethacrylic acid-polyethylene glycol graft copolymer) (manufactured by Kao Corporation, Mighty 1000SR) is blended, stirred for 30 minutes, and contains an acrylic emulsion and a water reducing agent. Emulsion composition 1 (for reference example) containing no cement was prepared.

<Preparation of emulsion compositions 2 to 4 (for reference examples), emulsion compositions 5 to 8 (for examples), emulsion compositions 9 and 10 (for reference examples), and emulsion compositions 11 to 13 (for comparative examples) >
As shown in Table 1 below, except for changing the blending amount of water reducing agent, surface modifier (main component: polyether compound and ethylene oxide) (Hibidan B, Takemoto Yushi Co., Ltd.) and oil (soybean oil) In the same manner as in the preparation of emulsion composition 1, each emulsion composition (without cement) was prepared.

  Next, an emulsion composition for a waterproof coating material was prepared using each of the above emulsion compositions (without cement) and cement.

[ Reference Examples 1 to 4 , Examples 1 to 4 , Reference Examples 5 and 6, Comparative Examples 1 to 3]
Without adding water to each emulsion composition (without cement), water amount (W) / cement amount (C) = 1.5 (weight ratio), emulsion amount (polymer: P) / cement amount (C) = 1.5 An emulsion composition for a waterproof coating material was prepared so as to satisfy (weight ratio). That is, 150 parts of each emulsion composition (resin content) prepared as described above, 100 parts of cement (Sumitomo Osaka Cement, ordinary Portland cement), 100 parts of sand, and 150 parts of water were blended, Each slurry was prepared by kneading with a disper for 1 minute to prepare an emulsion composition for a waterproof coating material. The content (parts) of water reducing agent and surface modifier for 100 parts of cement and the content (parts) for 100 parts of acrylic resin in the acrylic emulsion of fats and oils are also shown in Table 2 below. It was.

  Each characteristic was evaluated according to the following reference | standard using each emulsion composition for waterproofing | coated films | membranes obtained in this way. The results are shown in Table 2 above.

《Checking evaluation criteria》
Each emulsion composition for waterproofing membrane was applied to a polyolefin damper plate (20 cm × 20 cm) with a brush so as to be 1 kg / m ² . The coated product was placed horizontally in a 35 ° C. constant temperature bath, dried, and the coating film surface was judged by the following method.
X: A strip-shaped dent arises in the coating-film surface.
○: Cracks do not occur to the extent that the coating film has streaks.
(Double-circle): A crack does not arise at all in a coating film.

From the results of Table 2, all of the examples (Examples 1 to 4) are excellent in miscibility with each emulsion composition and cement, and can be uniformly formed, and the evaluation of checking is good. It was good. Since a delayed water reducing agent was used, the setting speed of cement was delayed and no thickening was observed. Moreover, since a predetermined amount of the surface modifying agent was contained, the products of Examples 1 to 4 were particularly excellent in evaluation of checking, and the surface modifying effect was improved.

  In contrast, Comparative Examples 1 and 2 having a water reducing agent content of less than 5 parts were inferior in the evaluation of checking. Moreover, although the comparative example 3 products in which the content of the water reducing agent exceeds 40 parts, the evaluation of checking is good, but the film-forming property of the coating film is lowered, the film-forming property is poor, and the coating property is inferior. .

Next, the water absorption rate was evaluated according to the following criteria using each of the emulsion compositions for waterproofing coating films of Example 3 and Example 4 . The results are shown in Table 3 below.

<< Evaluation criteria for water absorption >>
Each emulsion composition for waterproofing film of Example 3 and Example 4 was poured into a mold having a width of 25 cm × depth of 25 cm × thickness of 2 mm and cured at a temperature of 20 ° C. ± 2 ° C. and a humidity of 65% ± 10%. The 7 day old coating film was cut into a width of 4 cm and a depth of 4 cm and immersed in water. The water absorption was calculated using the following formula (2).
Water absorption (%) = [weight after immersion (g) −weight before immersion (g)] / weight before immersion (g) × 100 (2)

From the results of Table 3, the Example 4 product containing fat (soybean oil) has a small increase in water absorption over time compared to the Example 3 product not containing oil and fat. It can be seen that

  The emulsion composition of the present invention is useful in the civil engineering / architecture field, and in particular, as a coating waterproofing material composition, a roof of a building, a sloped roof, a veranda, a roof balcony, an outer wall, a fence, an external corridor, a staircase, For waterproofing construction of underground backfill parts of buildings, underground joints, underground pits, miscellaneous drainage tanks, fireproof water tanks and other indoor or underground water tanks, waterproof parts around sash frames, water storage tanks, floors and subway walls It is very useful to use.

Claims (10)

An emulsion composition comprising an acrylic emulsion, a cement , a water reducing agent and a surface modifier, comprising 5 to 40 parts by weight of the water reducing agent with respect to 100 parts by weight of the cement , and the surface modifier Is an polyether composition containing at least one of ethylene oxide and propylene oxide .   The emulsion composition according to claim 1, wherein the acrylic resin constituting the acrylic emulsion has a glass transition temperature of -20 to -40 ° C.   The emulsion composition according to claim 1 or 2, wherein the acrylic resin constituting the acrylic emulsion is obtained by emulsion polymerization of an ethylenically unsaturated monomer in the presence of a reactive surfactant. object.   The water reducing agent is at least one selected from the group consisting of a naphthalene compound, a melamine compound, a lignin compound, and a polycarboxylic acid compound, according to any one of claims 1 to 3. An emulsion composition as described. The emulsion composition according to any one of claims 1 to 4, wherein the surface modifying agent is contained in an amount of 1 to 20 parts by weight with respect to 100 parts by weight of cement. Furthermore, fats and oils are contained, The emulsion composition of Claims 1-5 characterized by the above-mentioned. The emulsion composition according to claim 6 , wherein the fat is soybean oil. 8. The emulsion composition according to claim 6 or 7 , wherein the oil or fat is contained in an amount of 1 to 50 parts by weight based on 100 parts by weight of the acrylic resin in the acrylic emulsion. The emulsion composition according to any one of claims 1 to 8 , which is used for a waterproof coating material. A waterproofing coating film comprising the emulsion composition according to any one of claims 1 to 9 .