JP2012148936A - Polymer cement composition, coating film waterproofing material using it, and emulsion composition for polymer cement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer cement composition excellent in good balance of coating adaptability and coating film physical properties, a coating film waterproofing agent using it, and an emulsion composition for a polymer cement.SOLUTION: The polymer cement composition includes: an acrylic resin emulsion in which an acrylic resin is dispersed and stabilized with a polyvinyl alcohol resin; and a polyoxyalkylene compound. The mean degree of polymerization of the polyvinyl alcohol resin is 150-1,700, and the resin is an anion-modified polyvinyl alcohol resin.

Description

  The present invention relates to a polymer cement composition, a waterproof coating material using the same, and an emulsion composition for polymer cement, and more specifically, a rooftop of a building such as a flat roof, a veranda of a building, a wall, a balcony, a bathroom, The present invention relates to a polymer cement composition, a coating film waterproofing material using the polymer cement composition, and an emulsion composition for polymer cement, which are used for waterproof coating technology in the field of civil engineering and construction such as the outer surface of a freezer warehouse.

  Conventionally, as a polymer cement composition for a waterproof coating material, an ethylene-vinyl acetate copolymer (EVA) emulsion obtained by emulsion polymerization using a polyvinyl alcohol resin (PVA resin) as a protective colloid, cement, What used together is used. This polymer cement composition has been used as a waterproof coating material that can be applied by roller coating, but has a problem that the obtained coating film lacks flexibility and weather resistance.

Therefore, in order to improve the coating film properties such as flexibility and weather resistance of the coating film, an acrylic resin that can easily provide a coating film generally exhibiting excellent flexibility and weather resistance instead of EVA emulsion. Polymer cement compositions using emulsions have been proposed.
For example, Patent Document 1 discloses that a hydraulic component containing 10% by mass or more of alumina cement, and a synthetic resin emulsion (acrylic resin) in an amount of 1 to 80 parts by mass in terms of solid content with respect to 100 parts by mass of the hydraulic component. Emulsions) and hydraulic compositions containing 0.1 to 15 parts by weight of shrinkage reducing agents have been proposed.

JP 2006-44958 A

  However, in the composition described in Patent Document 1, when the viscosity of the composition is reduced to such an extent that the composition can be applied with a roller at the time of application, cracking (checking) occurs in the coating film after coating and drying. There was a problem that the waterproof performance would be deteriorated.

  The present invention has been made in view of such circumstances, and is a polymer cement composition excellent in balance between coating suitability and coating film physical properties, a coating film waterproofing material using the same, and an emulsion composition for polymer cement. The purpose is to provide.

  The inventors of the present invention have made extensive studies in order to obtain a polymer cement composition having a good balance between coating suitability and coating film properties. When an acrylic resin emulsion dispersed and stabilized with a polyvinyl alcohol resin that is a water-soluble polymer dispersant (protective colloid) and a polyoxyalkylene compound that is a water-soluble oligomer dispersant coexist in the polymer cement. To obtain a polymer cement composition synergistically imparted with the excellent coating properties of the polyvinyl alcohol resin, which is a water-soluble polymer dispersant, and the excellent coating suitability of the water-soluble oligomer dispersant The present invention has been found.

That is, the first gist of the present invention is a polymer cement composition containing an acrylic resin emulsion in which an acrylic resin is dispersed and stabilized by a polyvinyl alcohol resin and a polyoxyalkylene compound.
Moreover, this invention makes the 2nd summary the coating-film waterproofing material characterized by including a polymer cement composition.
Furthermore, this invention makes the 3rd summary the emulsion composition for polymer cement containing the acrylic resin emulsion by which the acrylic resin was disperse-stabilized with the polyvinyl alcohol-type resin, and the polyoxyalkylene compound.

  As described above, the polymer cement composition of the present invention comprises an acrylic resin emulsion dispersed and stabilized with a polyvinyl alcohol resin that is a water-soluble polymer dispersant, and a polyoxyalkylene compound that is a water-soluble oligomer dispersant. In the polymer cement. Therefore, the polymer cement composition of the present invention has a good balance between the excellent film properties of the polyvinyl alcohol resin, which is a water-soluble polymer dispersant, and the excellent coating properties of the water-soluble oligomer dispersant. It will be a thing.

  And the waterproof coating material comprising the polymer cement composition of the present invention has excellent flexibility and weather resistance of the coating film, and also improves the elongation of the coating film. Are better.

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

  The polymer cement composition of the present invention is a composition containing an acrylic resin emulsion in which an acrylic resin is dispersed and stabilized by a PVA resin that is a protective colloid, a polyoxyalkylene compound, and cement.

Hereinafter, each component will be described.
[Acrylic resin emulsion in which acrylic resin is dispersed and stabilized by polyvinyl alcohol resin (PVA resin)]
As said PVA-type resin, what has the specific average polymerization degree shown next is preferable.
It is preferable that the average degree of polymerization of PVA-type resin is 150-1700, More preferably, it is 200-1200, More preferably, it is 250-700. If the average degree of polymerization of the PVA-based resin is too small, the effect of suppressing cracking tends to be low, and if the average degree of polymerization is too large, the viscosity becomes too high and the leveling property tends to decrease.

  In the present invention, the average degree of polymerization can be determined according to the method for calculating the average degree of polymerization described in JIS K 6726.

  The average saponification degree of the PVA-based resin is preferably 85 mol% or more, more preferably 86 to 99.9 mol%, and still more preferably 86.5 in that no cloud point is generated during polymerization. 99.5 mol%. When the average saponification degree of the PVA-based resin is too high, the polymerization does not easily proceed stably, and even when the polymerization is completed, the storage stability of the emulsion tends to be inferior, and when the average saponification degree is too low, it is obtained. There is a tendency that the average particle size of the copolymer tends to be too small. As a result, there is a tendency that the viscosity of the emulsion composition becomes too high and the workability is lowered.

  In the present invention, the average saponification degree can be determined according to the saponification degree calculation method described in JIS K 6726.

  In the present invention, the PVA-based resin means PVA itself or modified by, for example, various modified species, and the degree of modification is usually 20 mol% or less, preferably 15 mol% or less, more preferably It is 10 mol% or less.

  Examples of the modified PVA resin include an anion modified PVA resin modified with an anionic group including a carboxylic acid group, a sulfonic acid group, and a phosphoric acid group, and a cation modified with a cation group including a quaternary ammonium group. Modified PVA resin, modified PVA resin modified with various functional groups including acetoacetyl group, diacetone acrylamide group, mercapto group, silanol group, etc., or represented by the following general formula (1), Examples thereof include PVA-based resins having a 1,2-diol bond in the side chain. Among these, from the viewpoint of viscosity stability, an anion-modified PVA resin and a PVA resin having a 1,2-diol bond in the side chain are preferable.

R ¹ , R ² and R ³ are each independently a hydrogen atom or an alkyl group, preferably a hydrogen atom. Such alkyl groups are preferably those having 1 to 3 carbon atoms, particularly preferably those having 1 to 2 carbon atoms, and still more preferably 1 carbon atoms.

  In this invention, it is preferable that the usage-amount of PVA-type resin is 0.01-20 weight part with respect to 100 weight part of the below-mentioned ethylenically unsaturated monomer whole, More preferably, it is 0.1-10. Part by weight, particularly preferably 0.5 to 5 parts by weight. If the amount of PVA resin used is too small, the amount of protective colloid at the time of emulsion polymerization will be insufficient and the polymerization stability will tend to be poor. If the amount used is too large, the viscosity of the acrylic resin emulsion will be low. There is a tendency to increase and decrease stability.

  Here, the used PVA resin is usually present in the entire amount in the acrylic resin emulsion formed by polymerization. That is, 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and still more preferably 0.5 to 5 parts by weight of PVA resin in 100 parts by weight of the copolymer in the acrylic resin emulsion. Will exist.

  In the present invention, a PVA-based resin is used as a protective colloid agent (dispersion stabilizer). However, a modified or non-modified partially / saponified PVA-based resin or the like is used as long as the object of the present invention is not impaired. You may use together.

  In the present invention, the PVA resin is usually made into an aqueous solution using an aqueous medium, and this is used in the process of emulsion polymerization. Here, the aqueous medium refers to water or an alcoholic solvent mainly composed of water, preferably water.

  The amount (nonvolatile content) of the PVA resin in the aqueous solution is not particularly limited, but is preferably 5 to 30% by weight from the viewpoint of ease of handling.

Next, the acrylic resin emulsion will be described.
The acrylic resin emulsion used in the present invention is obtained by dispersing and stabilizing an acrylic resin with a PVA resin.

The acrylic resin constituting the acrylic resin emulsion is preferably a homopolymer or copolymer of an ethylenically unsaturated monomer, more preferably, among ethylenically unsaturated monomers, It is an acrylic copolymer having a main component of (meth) acrylic acid alkyl ester and copolymerized with other ethylenically unsaturated monomers.
In the present invention, the above-mentioned main component of the (meth) acrylic acid alkyl ester means that it contains an amount exceeding 50% by weight of the total ethylenically unsaturated monomer, preferably an ethylenically unsaturated monomer. It means to contain 60% by weight or more of the whole mass.

Hereinafter, the ethylenically unsaturated monomer that is a polymerization component forming the acrylic resin will be described in detail.
Examples of the ethylenically unsaturated monomer include the following (a) to (k). These may be used alone or in combination of two or more. Among these, (meth) acrylic acid alkyl ester (a) is preferable.
(A) Alkyl ester of (meth) acrylic acid.
(B) A hydroxyl group-containing ethylenically unsaturated monomer.
(C) A carboxyl group-containing ethylenically unsaturated monomer.
(D) An epoxy group-containing ethylenically unsaturated monomer.
(E) a methylol group-containing ethylenically unsaturated monomer.
(F) Alkoxyalkyl group-containing ethylenically unsaturated monomer.
(G) Cyano group-containing ethylenically unsaturated monomer.
(H) An ethylenically unsaturated monomer having two or more radically polymerizable double bonds.
(I) An ethylenically unsaturated monomer having an amino group.
(J) An ethylenically unsaturated monomer having a sulfonic acid group.
(K) An ethylenically unsaturated monomer having a phosphate group.

As the acrylic resin used in the present invention, in addition to the above (a) to (k), vinyl propionate, vinyl versatate, vinyl pyrrolidone, methyl vinyl ketone, butadiene, ethylene, propylene, vinyl chloride, vinylidene chloride, etc. A monomer can also be used suitably as desired.
In the present invention, monomers such as styrene and vinyl acetate are preferably not used in combination because of poor weather resistance.

Next, the monomers exemplified in the above (a) to (k) will be described in detail.
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 hydroxyl group-containing ethylenically unsaturated monomer (b) include, for example, 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 said carboxyl group-containing ethylenically unsaturated monomer (c), (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid etc. can be used, for example, These are independent or 2 types. 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 (d) 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 (e) include N-methylol (meth) acrylamide, dimethylol (meth) acrylamide and the like, and these may be used alone or in combination of two or more.

  Examples of the alkoxyalkyl group-containing ethylenically unsaturated monomer (f) 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 (g) include (meth) acrylonitrile.

  Examples of the ethylenically unsaturated monomer (h) 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 (i) 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 (j) 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 (k) 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.

  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.

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

  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 them, potassium persulfate, sodium persulfate, redox catalyst (oxidizing agent: potassium persulfate, sodium persulfate, reducing agent: sodium sulfite, acidic sodium sulfite, Rongalite, ascorbic acid) etc. Is preferred.

  The amount of the polymerization initiator used is preferably in the range of 0.01 to 5 parts by weight, more preferably 0.03 to 3 parts by weight, based on 100 parts by weight of the whole ethylenically unsaturated monomer. It is more preferable. When the amount of the polymerization initiator used is too small, the polymerization rate tends to be slow, and when it is too large, the molecular weight of the resulting copolymer is lowered, which tends to be undesirable in terms of water resistance.

  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.

Examples of the polymerization regulator include chain transfer agents and pH buffering agents.
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 terms of carrying out the polymerization stably, but may reduce the degree of polymerization of the acrylic resin and lower 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 by weight, more preferably 0.01 to 0. 0 parts by weight based on 100 parts by weight of the whole ethylenically unsaturated monomer. It is preferably 5 parts by weight. When the amount of the chain transfer agent used is too small, the effect as a chain transfer agent tends to be insufficient. When the amount of use is 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.

  The amount of the pH buffer used is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the whole ethylenically unsaturated monomer. When the amount of the pH buffer used is too small, the effect as a polymerization regulator tends to be insufficient, and when the amount used is too large, the reaction tends to be inhibited.

Examples of the surfactant include alkyl or alkyl allyl sulfate, alkyl or alkyl allyl sulfonate, dialkyl sulfosuccinate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium alkyl sulfonate, and the like. Anionic surfactants of: cationic surfactants such as alkyltrimethylammonium chloride and alkylbenzylammonium chloride; polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene carboxylic acid ester, polyoxyethylene glycol type, Nonionic surfactants such as polyoxyethylene propylene glycol type; and ammonium = α-sulfonato-ω-1- (allyloxymethyl) ) Alkyloxypolyoxyethylene, α-sulfo-ω- (1- (alkoxy) methyl-2- (2-propenyloxy) ethoxy-poly (oxy-1,2-ethanediyl) ammonium salt, polyoxyethylene alkylpropenyl Examples thereof include phenyl ether, and these may be used alone or in combination of two or more.
A reactive surfactant having a double bond in the molecule may be used.

  The amount of the surfactant used is usually preferably 0.1 to 10 parts by weight, more preferably 0.5 to 10 parts by weight, particularly 100 parts by weight of the whole ethylenically unsaturated monomer. The range is preferably 0.5 to 5 parts by weight. If the amount of the surfactant used is too small, there is a tendency to become unstable in terms of polymerization stability, and if it is too large, the average particle diameter of the resulting copolymer tends to be too small, and the result There is a tendency that the viscosity of the emulsion composition becomes too high to cause problems such as deterioration in workability.

  Examples of the plasticizer include an adipate plasticizer, a phthalic acid plasticizer, and a phosphoric acid plasticizer. Examples of the film-forming aid include those having a boiling point of 260 ° C. or higher. .

  The amount of the plasticizer and film-forming aid used can be appropriately selected as long as the object of the present invention is not impaired. For example, the plasticizer is based on 100 parts by weight of the whole ethylenically unsaturated monomer Usually 0.1 to 50 parts by weight, and the film-forming aid is usually 0.1 to 50 parts by weight with respect to 100 parts by weight of the whole ethylenically unsaturated monomer.

Next, the production of the acrylic resin emulsion used in the present invention will be described.
The acrylic resin emulsion used in the present invention can be produced, for example, by emulsion polymerization of ethylenically unsaturated monomers such as the above (a) to (k) using a PVA resin as a protective colloid agent. it can. In this polymerization process, an acrylic resin emulsion having an acrylic resin dispersed and stabilized by a PVA resin as a protective colloid agent as a dispersoid is produced.

  In the acrylic resin emulsion, the dispersoid is the acrylic resin, and the dispersion medium is preferably a dispersion medium in which the acrylic resin becomes the 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.

As a polymerization method of the acrylic resin emulsion used in the present invention, [1] a method in which all amounts of ethylenically unsaturated monomer, PVA resin, surfactant, water and the like are charged, and the temperature is raised and polymerized, [2 ] PVA resin, water, surfactant, and a part of ethylenically unsaturated monomer were charged into a reaction can, polymerized by heating, and then the remaining ethylenically unsaturated monomer was added dropwise or dividedly. A method for continuing polymerization, [3] A method in which a PVA resin, water, a surfactant, etc. are charged in a reaction can and heated, and then the whole amount of ethylenically unsaturated monomer is added dropwise or dividedly to polymerize. Can be given. Among these, the methods [2] and [3] are preferable because the polymerization temperature can be easily controlled.
The PVA resin may be used in any step during the initial polymerization of the ethylenically unsaturated monomer, during the drop polymerization, during the late ripening, or during the additional polymerization of the residual monomer treatment.

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 suitable as a polymerization condition in the polymerization method of the above [1]. The reaction may be performed for about 1 to 8 hours later.
The polymerization conditions in the above polymerization method [2] include polymerization of 1 to 50% by weight of the ethylenically unsaturated monomer usually at 40 to 90 ° C. for 0.1 to 4 hours, and then the remaining ethylenically unsaturated monomer. For example, the saturated monomer may be dropped or dividedly added 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 the above [3], water is charged into a polymerization can, the temperature is raised to 40 to 90 ° C., and the monomer mixture is dropped or added in portions over about 2 to 7 hours. And aging at the above temperature for about 1 to 3 hours.

  Stirring of the above-mentioned emulsion during emulsification can be performed using a stirring device in which the components are mixed and equipped with stirring blades such as homodispers and paddle blades. There is no problem as long as the temperature during emulsification is such that the mixture does not react during emulsification.

  In addition, the acrylic resin emulsion used in the present invention is appropriately added with additives such as organic pigments, inorganic pigments, water-soluble additives, pH adjusters, preservatives, antifoaming agents, and antioxidants as necessary. It can be blended.

  The average particle diameter of the acrylic resin in the acrylic resin emulsion is preferably in the range of 50 to 700 nm, particularly 100 to 500 nm, and more preferably 150 to 350 nm. If the particle size is too small, the viscosity of the emulsion becomes too high and the dispersibility of the emulsion tends to decrease when admixed with cement. If the particle size is too large, a dense coating film can be obtained when forming the coating film. Is difficult, and there is a tendency that it is not preferable in terms of strength. The measurement of the average particle diameter is based on the light scattering method.

  The average particle diameter of the acrylic resin can be set within a predetermined range by appropriately adjusting the prescription used at the time of polymerization, for example, by adjusting the stirring speed at the time of polymerization, etc. Can be set to

  The glass transition temperature (Tg) of the acrylic resin is in the range of 0 to −70 ° C., more preferably −10 to −60 ° C., particularly −20 to −40, in view of improving the low-temperature elongation of the coating film. It is preferable that it is ° C. 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. There is a tendency to become.

The glass transition temperature (Tg) of the acrylic resin 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.

The non-volatile content concentration (solid content concentration) of the acrylic resin emulsion is preferably 45% by weight or more, particularly 45 to 70% by weight, more preferably 50 to 60% by weight from the viewpoint of color developability when cement is mixed. % Is preferable in terms of color developability, stability, and workability.
In addition, the non-volatile content concentration in this invention means the non-volatile content concentration (solid content concentration) after drying at 105 degreeC for 1 hour.

  The viscosity of the acrylic resin emulsion is preferably 10 to 50000 mPa · s, particularly 10 to 10000 mPa · s, more preferably 10 to 5000 mPa · s in terms of handling.

The acrylic resin emulsion used in the present invention may contain additives such as fats and oils.
Examples of the fat 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 amount of the fat is preferably 1 to 50 parts by weight, particularly 2 to 40 parts by weight, more preferably 5 to 20 parts by weight, with respect to 100 parts by weight of the acrylic resin in the acrylic resin emulsion. The amount of 6 to 10 parts by weight is particularly desirable for imparting waterproofness.

  The mixing method of the acrylic resin emulsion and additives such as fats and oils is, for example, a method in which after the polymerization of the acrylic resin emulsion is completed, the additive is added afterwards and charged into the polymerization can with stirring. Can be given.

[Polyoxyalkylene compound]
Specific examples of the polyoxyalkylene compound include polyalkylene glycol and monoetherified products, monoether monoesterified products, dietherified products, monoesterified products, and diesterified products of polyalkylene glycol.
The polyalkylene glycol is obtained by polymerization or copolymerization of alkylene oxides such as ethylene oxide (EO) and propylene oxide (PO). From the viewpoint of handling properties, it is preferable that the polyalkylene glycol has more hydrophilic EO than hydrophobic PO.

Examples of the monoetherified product include polyoxyethylene monooleyl ether, polyoxyethylene monocetyl ether, polyoxyethylene monostearyl ether, polyoxyethylene monolauryl ether, polyoxyethylene monododecyl ether, polyoxyethylene monononylphenol ether, Examples include polyoxyethylene monooctyl phenyl ether.
Examples of the monoether monoester product include methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, propoxypolyethylene glycol (meth) acrylate, and the like.
Examples of the diether compound include polyoxyethylene dioleyl ether, polyoxyethylene dicetyl ether, polyoxyethylene distearyl ether, polyoxyethylene dilauryl ether, polyoxyethylene didodecyl ether, polyoxyethylene dinonyl phenol ether, Examples thereof include oxyethylene dioctyl phenyl ether.

Examples of monoester products include polyoxyethylene mono (meth) acrylate, polyoxyethylene monooleate, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene monobovine fatty acid ester, polygluterin monostearate. Examples include rates.
Examples of the diesterified product include polyoxyethylene di (meth) acrylate, polyoxyethylene dioleate, polyoxyethylene dilaurate, polyoxyethylene distearate, polyoxyethylene dibovine fatty acid ester, polyglycerin distearate and the like. Illustrated.

  The weight average molecular weight of the polyoxyalkylene compound is preferably 1000 or more, particularly preferably 1500 to 10,000, and further preferably 2000 to 5000, from the viewpoint of suppressing cracking of the coating film. If the weight average molecular weight of the polyoxyalkylene compound is too low, the effect of suppressing cracking tends to be low, and if it is too high, the viscosity tends to be high and the leveling property tends to decrease.

  In the present invention, the weight average molecular weight means a weight average molecular weight in terms of standard polystyrene molecular weight.

  The content of the polyoxyalkylene compound is preferably 0.5 to 15 parts by weight, particularly preferably 1 to 12 parts by weight, and still more preferably 1.5 to 100 parts by weight of the solid content of the acrylic resin emulsion. -10 parts by weight. If the content of the polyoxyalkylene compound is too small, coating film cracking (checking) after coating and drying cannot be sufficiently suppressed, and the waterproof performance tends to be inferior. There is a tendency for the strength of the film to decrease.

[cement]
Examples of the cement include ordinary Portland cement, alumina cement, early-strength Portland cement, ultra-high-strength Portland cement, medium heat Portland cement, low heat Portland cement, sulfate-resistant Portland cement, blast furnace cement, fly ash cement, silica cement and the like. Among them, Portland cement is preferable from the viewpoint of workability.

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

  Thus, the polymer cement composition of the present invention can be obtained by preparing a composition containing the acrylic resin emulsion in which the acrylic resin is dispersed and stabilized by the PVA resin, the polyoxyalkylene compound, and the cement.

  The blending method of the acrylic resin emulsion, polyoxyalkylene compound, and cement is not particularly limited. For example, in the production process of [I] acrylic resin emulsion, polymerization of ethylenically unsaturated monomer is performed. The method of blending cement after blending the polyoxyalkylene compound during the late aging of the time, and [II] blending the polyoxyalkylene compound in the acrylic resin emulsion after completion of the polymerization of the ethylenically unsaturated monomer, A method of blending cement is included.

  The polymer cement composition can be used as mortar or concrete by further blending water, sand or gravel.

  The amount of water to be used as mortar or concrete is preferably 50% by weight or less, more preferably 30% by weight or less, based on the solid content of the polymer cement composition.

  In addition, the amount of sand and gravel when used as mortar or concrete is preferably 30 to 300% by weight, more preferably 50 to 150% by weight, based on the solid content of the polymer cement composition. Is preferred.

  The polymer cement composition of the present invention includes a cement water reducing agent or fluidizing agent (for example, lignin-based, naphthalene-based, melamine-based, carboxylic acid-based, etc.), shrinkage reducing agent (for example, glycol) Ethers, polyethers, etc.), cold-resistant agents (eg, calcium chloride), waterproofing agents (eg, stearic acid), rust inhibitors (eg, phosphates), viscosity modifiers (eg, methylcellulose, hydroxy) Ethyl cellulose, polyvinyl alcohol, etc.), dispersants (eg, polycarboxylic acids, inorganic phosphorus, etc.), antifoaming agents (eg, silicon, mineral oils, etc.), preservatives, reinforcing agents (eg, steel fibers, glass fibers) , Synthetic fibers, carbon fibers, etc.) may be used alone or in combination of two or more.

  In addition to the above components, various aggregates such as pozzolanic materials such as calcium carbonate, kaolin, clay, diatomaceous earth, silica fume, fly ash, blast furnace slag, and natural and artificial lightweight aggregates may be blended.

  The polymer cement composition preferably has a viscosity of 5000 mPa · s or less, particularly preferably 50 to 4500 mPa · s, more preferably 100, as measured with a B-type viscometer at 23 ° C. and a rotation speed of 10 rpm. ˜4000 mPa · s. When the viscosity is too low, the inorganic powder tends to settle and the uniformity of the coating film tends to be impaired. When the viscosity is too high, the workability during coating tends to be reduced.

  In addition, when using a polymer cement composition as a mortar, as in general mortar, an essential component and an optional component are added, and after adding an appropriate amount of water, a kneader or the like is used. It can be prepared by kneading.

  The polymer cement composition of the present invention retains the properties as an acrylic resin with respect to flexibility and weather resistance, and the PVA resin and polyoxyalkylene as a resin dispersing agent coexist so that after drying. Therefore, it is useful to use it as a waterproofing agent for coatings since it can be used as a waterproofing agent with excellent leveling properties during coating.

  The waterproof coating material using the polymer cement composition of the present invention can be obtained, for example, by applying the polymer cement composition with a roller, a plastering brush or a trowel, or spraying with a spray.

  In addition, although the thickness of the said coating-film waterproofing material changes with enforcement places etc., it is 0.3-5 mm normally, Preferably it is 0.5-3 mm, Most preferably, it is 0.7-2 mm.

  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, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to a following example, unless the summary is exceeded.
In the following examples and the like, “parts” and “%” mean “parts by weight” and “% by weight”, respectively.

First, prior to the examples and comparative examples, the acrylic resin emulsions shown below were prepared.
<Preparation of acrylic resin emulsion 1>
In a container, weigh 31 parts of water, 3 parts of surfactant (made by ADEKA, trade name “ADEKA rear soap SR-10”), 67.4 parts of butyl acrylate, 31.6 parts of methyl methacrylate, and 1 part of acrylic acid. Then, a monomer emulsified mixed liquid (100 parts of ethylenically unsaturated monomer) was prepared.
Next, 40 parts of water was weighed into a stainless steel reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, and PVA 0. 5 having an average degree of polymerization of 150 and an average degree of saponification of 99 mol%. 3 parts were added and dissolved at 85 ° C. for 1 hour, and then kept at 80 ° C.
Next, after adding 10% of the previously prepared monomer emulsified mixture to the stainless steel reaction vessel, 0.7 part of 8.6% potassium persulfate (polymerization initiator) is added to the reaction vessel. Added and allowed to react for 30 minutes. Then, the remaining monomer emulsified mixed solution and 6.3 parts of 8.6% potassium persulfate were dropped into a glass reaction vessel over 3 hours, and polymerization was performed at 80 ° C.
After completion of the dropwise addition, aging was performed at 80 ° C. for 60 minutes, and 7.2 parts of a 3.8% aqueous solution of t-butyl hydroperoxide and a 7.2% aqueous solution of sodium sulfite 4.2% were added for 1 hour. Additional polymerization was performed to complete the reaction, and an acrylic resin emulsion 1 having a nonvolatile content of 52.4% was obtained (average particle size: 0.3 μm).
In addition, the glass transition temperature (Tg) of acrylic resin was -20 degreeC.

<Preparation of acrylic resin emulsion 2>
An acrylic resin is prepared in the same manner as the acrylic resin emulsion 1 except that PVA having an average polymerization degree of 300 and an average saponification degree of 99 mol% is used instead of PVA having an average polymerization degree of 150 and an average saponification degree of 99 mol%. Resin emulsion 2 (nonvolatile content: 52.3%) was obtained (average particle size: 0.3 μm).

<Preparation of acrylic resin emulsion 3>
Acrylic resin emulsion 1 was used in the same manner as acrylic resin emulsion 1 except that PVA having an average polymerization degree of 800 and an average saponification degree of 99 mol% was used instead of PVA having an average polymerization degree of 150 and an average saponification degree of 99 mol%. System resin emulsion 3 (nonvolatile content: 52.3%) was obtained (average particle size: 0.3 μm).

<Preparation of acrylic resin emulsion 4>
An acrylic resin is prepared in the same manner as the acrylic resin emulsion 1 except that PVA having an average polymerization degree of 600 and an average saponification degree of 92 mol% is used instead of PVA having an average polymerization degree of 150 and an average saponification degree of 99 mol%. System resin emulsion 4 (nonvolatile content: 52.3%) was obtained (average particle size: 0.2 μm).

<Preparation of acrylic resin emulsion 5>
An acrylic resin emulsion 1 is used in the same manner as the acrylic resin emulsion 1 except that PVA having an average polymerization degree of 1400 and an average saponification degree of 99 mol% is used instead of PVA having an average polymerization degree of 150 and an average saponification degree of 99 mol%. Resin emulsion 5 (nonvolatile content: 52.4%) was obtained (average particle size: 0.3 μm).

<Preparation of acrylic resin emulsion 6>
Acrylic resin emulsion 1 was used in the same manner as in the acrylic resin emulsion 1 except that PVA having an average polymerization degree of 1400 and an average saponification degree of 88 mol% was used instead of PVA having an average polymerization degree of 150 and an average saponification degree of 99 mol%. Resin emulsion 6 (nonvolatile content: 52.3%) was obtained (average particle size: 0.2 μm).

<Preparation of acrylic resin emulsion 7>
Except for using PVA having an average degree of polymerization of 150 and an average degree of saponification of 99 mol% instead of sulfonic acid-modified (modified degree: 3 mol%) PVA having an average degree of polymerization of 300 and an average degree of saponification of 99 mol% In the same manner as in the acrylic resin emulsion 1, an acrylic resin emulsion 7 (nonvolatile content: 52.3%) was obtained (average particle size: 0.2 μm).

<Preparation of acrylic resin emulsion 8>
In place of PVA having an average degree of polymerization of 150 and an average degree of saponification of 99 mol%, except that carboxylic acid-modified (modified degree: 3 mol%) PVA having an average degree of polymerization of 1100 and an average degree of saponification of 99 mol% is used. In the same manner as in the acrylic resin emulsion 1, an acrylic resin emulsion 8 (nonvolatile content: 52.4%) was obtained (average particle size: 0.4 μm).

<Preparation of acrylic resin emulsion 9>
Instead of PVA having an average degree of polymerization of 150 and an average degree of saponification of 99 mol%, PVA having an average degree of polymerization of 300, an average degree of saponification of 99 mol% and having a 1,2-diol bond in the side chain (1,2 of the side chain) -Acrylic resin emulsion 9 (nonvolatile content: 52.4%) was obtained in the same manner as the acrylic resin emulsion 1 except that the content of diol bonds: 3 mol% was used (average particle size: 0.3 μm).

<Preparation of acrylic resin emulsion 10>
An acrylic resin emulsion 10 (nonvolatile content: 52.2%) was obtained in the same manner as the acrylic resin emulsion 1 except that PVA was not used during the polymerization of the acrylic resin (average particle size: 0.3 μm). ).

<Polyoxyalkylene compound>
The following were prepared as the polyoxyalkylene compound 1.
・ Nippon Yushi Co., Ltd., Dodox DSP-7550 (Mw = 700)
The following were prepared as the polyoxyalkylene compound 2.
・ Nippon Yushi Co., Ltd., Dodox DSP E-20 (Mw = 2000)
The following were prepared as the polyoxyalkylene compound 3.
・ Nippon Yushi Co., Ltd., Dodox DSP E-40 (Mw = 4000)
The following were prepared as the polyoxyalkylene compound 4.
・ Nippon Yushi Co., Ltd., Dodox DSP E-60 (Mw = 6000)

[Example 1]
The acrylic resin emulsion 1 obtained above is cooled to room temperature (25 ° C.), and 2.2 parts of a 10% caustic soda aqueous solution as a neutralizing agent is added to 100 parts of the solid content of the acrylic resin emulsion 1. After the addition, 6 parts (3 parts in terms of solid content) of a 50% aqueous solution of polyoxyalkylene compound 4 [manufactured by NOF Corporation, Dodox DSP E-60 (Mw = 6000)] is added and diluted with water. After making an emulsion composition having a non-volatile content (solid content) of 52% and a pH of 7 to 10, 135 parts of Portland cement was added, and stirred at 1000 rpm for 1 minute using a disper to obtain a polymer cement composition.

"viscosity"
The viscosity of the polymer cement composition was measured at 23 ° C. and a rotation speed of 10 rpm using a BH viscometer (manufactured by Tokyo Keiki Co., Ltd.).
The viscosity is preferably 5000 mPa · s or less.

《Crack area ratio of coating film》
The obtained polymer cement composition was poured into a 40 cm × 40 cm mold and dried by standing in a dryer at 60 ° C. for 30 minutes.
Subsequently, the coated surface of 40 cm × 40 cm after drying was divided into 100 squares with 4 cm × 4 cm square as one square, and the number of squares having cracks was measured.
The occurrence of cracks is preferably 5 points or less.

《Coating strength, coating elongation》
The polymer cement composition was poured into a mold having a width of 25 cm, a depth of 25 cm, and a thickness of 2 mm, and cured at a temperature of 20 ° C. ± 2 ° C. and a humidity of 65% ± 10%. A 7 day old paint film was punched into the shape of No. 2 dumbbell. Using a tensile tester, a dumbbell was sandwiched between the chucks at a distance of 60 mm, a tensile test was performed at a speed of 200 mm / min, and the film strength and film elongation were calculated from the maximum tensile load and the distance between the marked lines at break.
The calculation method is based on the following equations (1) and (2).
TB = PB / A (1)
TB: Coating film strength (N / mm ² ) PB: Maximum tensile load (N)
A: Cross-sectional area (mm ² )
E = [(L-20) / 20] × 100 (2)
E: Elongation of coating film (%) L: Distance between marked lines at breakage The coating film strength is preferably 0.7 N / mm ² or more, and the coating film elongation is preferably 200% or more.

[Examples 2 to 10, Comparative Examples 1 to 3]
A polymer cement composition was prepared according to Example 1 except that the type of acrylic resin emulsion and the type of polyoxyalkylene compound were changed to the combinations and blending amounts shown in Table 1 below.
And each characteristic was evaluated like Example 1 using each polymer cement composition. The results are also shown in Table 1 below.

  From the results of Table 1 above, the examples contain an acrylic resin emulsion in which an acrylic resin is dispersed and stabilized by a polyvinyl alcohol resin, a polyoxyalkylene compound, and cement. Excellent balance.

On the other hand, since the comparative example 1 used the acrylic resin emulsion which does not mix | blend PVA, generation | occurrence | production of the crack of a coating film cannot be suppressed and the polyoxyalkylene compound is used in large quantities. Therefore, the strength was also inferior.
Since the comparative example 2 did not mix | blend a polyoxyalkylene compound, its viscosity was high and coating property was inferior.
Since the comparative example 3 used the acrylic resin emulsion which did not mix | blend PVA, and also did not mix | blend the polyoxyalkylene compound, the crack of the coating film generate | occur | produced remarkably.

  The polymer cement composition of the present invention is useful in the field of civil engineering / architecture, and in particular, as a coating film 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 , Indoor or underground water tanks such as underground backfill parts of buildings, underground joints, underground pits and miscellaneous drainage tanks, fireproof water tanks, waterproofing parts around sash frames, water tanks for water supply, floors and peripheral walls of subways, etc. It is very useful to use in

Claims (9)

  A polymer cement composition comprising: an acrylic resin emulsion in which an acrylic resin is dispersed and stabilized by a polyvinyl alcohol resin; and a polyoxyalkylene compound.   2. The polymer cement composition according to claim 1, wherein the average degree of polymerization of the polyvinyl alcohol-based resin is 150 to 1700.   The polymer cement composition according to claim 1 or 2, wherein the polyvinyl alcohol resin is an anion-modified polyvinyl alcohol resin.   The polymer cement composition according to claim 1 or 2, wherein the polyvinyl alcohol resin is a polyvinyl alcohol resin having a 1,2-diol bond in the side chain.   The polymer cement composition according to any one of claims 1 to 4, wherein the polyoxyalkylene compound has a weight average molecular weight of 1000 or more.   The polymer according to any one of claims 1 to 5, wherein the content of the polyoxyalkylene compound is 0.5 to 15 parts by weight with respect to 100 parts by weight of the solid content of the acrylic resin emulsion. Cement composition.   The polymer according to any one of claims 1 to 6, wherein the viscosity of the polymer cement composition measured with a B-type viscometer under conditions of 23 ° C and a rotation speed of 10 rpm is 5000 mPa · s or less. Cement composition.   A waterproofing coating film comprising the polymer cement composition according to any one of claims 1 to 7.   An emulsion composition for polymer cement, comprising: an acrylic resin emulsion in which an acrylic resin is dispersed and stabilized by a polyvinyl alcohol-based resin; and a polyoxyalkylene compound.