JP5489091B2 - Re-emulsifiable resin powder composition, aqueous emulsion obtained by re-emulsifying the same, and building finish coating material using the same - Google Patents

Description

  The present invention relates to a re-emulsifiable resin powder composition obtained by drying a synthetic resin emulsion. More specifically, the water resistance and hardness of a coating film can be expressed from the initial stage after the coating film is formed. TECHNICAL FIELD The present invention relates to a re-emulsifiable resin powder composition having excellent durable adhesiveness and a high anti-skinning effect on the surface of a coating film, and having a good iron workability. . In addition, it can be used suitably for architectural finishing coating materials and powder coatings, but also for various uses such as admixtures for hydraulic materials such as cement and gypsum, wood or wood, and adhesives such as paper. Can be used.

  The re-emulsifiable resin powder is produced by drying the synthetic resin emulsion by a method such as spray drying, and since it is a powder, it can be handled more easily than the synthetic resin emulsion mainly used in cans and drum packaging. Usually, since it is a paper bag package, it is advantageous in terms of product storage and transportation costs. In addition, re-emulsifiable resin powder has less volatile components such as residual monomers than general synthetic resin emulsions, and does not rot because it does not contain water, so it does not require mold and preservatives. It has been recognized as a gentle product.

  In addition, since this re-emulsifiable resin powder can be re-emulsified in water simply by adding it to water and stirring at the time of use, it has so far been mainly used as a mixing agent for cement products such as concrete structures and mortar and gypsum putty. Furthermore, it is widely used for architectural finishing coating materials, powder paints, adhesives and the like. In particular, the re-emulsifiable resin powder can be mixed in advance with an inorganic hydraulic composition such as a building finish coating composition, a powder coating composition, and a mortar / gypsum putty. Cement products such as gypsum products, architectural finishes and paints can be formed.

  However, until now, re-emulsifiable resin powders blended in building finishing coating compositions, powder coating compositions, and inorganic hydraulic compositions such as mortar and gypsum have used polyvinyl alcohol and the like to emphasize re-emulsification. Vinyl acetate polymer, ethylene-vinyl acetate polymer, vinyl acetate-versaic acid vinyl ester polymer, vinyl acetate-acrylic polymer, etc. using a water-soluble resin as a protective colloid (dispersion stabilizer) There are many polymer re-emulsifiable resin powders having a highly hydrophilic composition, and there is almost no water resistance of the film, so that the initial expression of water resistance and hardness of the film is particularly insufficient, and it is used for exteriors. , It was insufficient in physical properties as a re-emulsifiable resin powder for architectural finishing coatings and powder coatings (hereinafter sometimes abbreviated as “architectural finishing coatings / powder coatings”).

  The necessity of the initial manifestation of water resistance of the paint film is such that, for example, when applied in summer, even if the weather changes suddenly and rains, the paint surface is not affected immediately after the application In addition, it is required that the painted surface is finished. In addition, the necessity of initial expression of coating film hardness is required when the coating surface is not affected even if it touches the coating film surface, such as when entering the next work process after coating. Because it is. This is a problem even in winter work where drying of the coating film is slow. Therefore, there has been a demand for a re-emulsifiable resin powder for architectural finishing coating materials and powder coatings, which has good initial development of water resistance and hardness of the coating film.

  On the other hand, however, architectural finish coating materials for exteriors are often given a design property by applying a three-dimensional pattern to the coating surface with a trowel etc. after coating, especially in the summertime. Even if the film thickness is about 1.5 to 2 mm, drying of the coating proceeds, so-called skinning of the coating film occurs, and it becomes impossible to pattern the coating surface with a trowel etc. in about 30 minutes after coating. There was a problem. As a patterning method, it is common from the point of work efficiency to pattern a certain area in a lump after coating, but in order to prevent the above problems, patterning is performed for each small area. There has also been proposed a method for performing design imparting.

  However, this method is inferior in work efficiency, and in some cases, the balance of patterns is expected to be lost. Therefore, from the market, it retains the initial expression of water resistance and hardness of the coating film, while on the other hand, it delays the drying of the coating surface and allows the coating surface to be patterned with a trowel etc. after coating There has been a demand for a re-emulsifiable resin powder having a high prevention effect, that is, a good balance of these contradictory physical properties, particularly for an architectural finishing coating material for exterior use.

  In general, many of the known re-emulsifiable resin powders that can be re-emulsified in water have a low degree of polymerization mainly due to the need to re-emulsify, and partially saponified polyvinyl alcohol is a protective colloid (dispersed) It is obtained by emulsion polymerization using a vinyl ester monomer mainly composed of vinyl acetate as a main component (see, for example, Patent Document 1 and Patent Document 2).

  Moreover, as a re-emulsifiable resin powder for the purpose of water resistance, as described in Patent Document 2 above, an emulsion powder composition containing a re-emulsifiable synthetic resin emulsion powder and an oxide or hydroxide of calcium or magnesium And at least one of an acetoacetic acid group and a mercapto group on the surface of a polymer particle composed of at least one of an ethylenically unsaturated monomer or a diene monomer, and the block character is 0. Re-emulsifiable synthetic resin powder adsorbed with 3 to 0.6 polyvinyl alcohol resin (see, for example, Patent Document 3), and further, acetoacetate ester group-containing polyvinyl further separated into a specific particle size into this block character An aqueous emulsifier having a value obtained by dividing the maximum value of the average degree of acetoacetic esterification of each alcohol by the minimum value is 1.0 to 3.0 Re-emulsifiable synthetic resin powder composed of tio emissions (e.g., see Patent Document 4) it has been proposed.

  However, the disclosed technique of Patent Document 1 does not aim at water resistance of the film, and is a hydrophobic monomer mainly selected from acrylic, styrene, vinyl, etc. in order to increase the water resistance of the film. Even though an attempt was made to produce a synthetic resin emulsion having a normal non-volatile content (40 to 50%) using, the polymerization stability was poor.

  In addition, in each of the disclosed techniques of Patent Documents 2 to 4, although some improvement in water resistance of the film is observed, initial development of water resistance and hardness of the coating film, and in addition, improvement in durable adhesion of the coating film, etc. Was still not satisfactory and further improvements were needed.

  Furthermore, in some cases, particularly in exterior building finish coating materials, the water resistance and hardness of the coating film may be devised to increase the non-volatile content in order to express the coating film from the initial stage after the coating film is formed. The time for enabling patterning with a trowel or the like will be shortened. In addition, in order to lengthen the time for enabling patterning, it is possible to use a water retention agent such as hydroxymethylcellulose, but this would rather significantly reduce the initial expression of water resistance and hardness of the coating film. It becomes.

  Therefore, the actual condition is that there is no product on the market that has a particularly good balance between the initial development of the water resistance and hardness of the coating film and the patterning property on the coated surface with a trowel after coating.

Japanese Patent Laid-Open No. 5-140325 Japanese Patent Laid-Open No. 5-179008 Japanese Patent Laid-Open No. 2002-60406 JP-A-2005-272481

  Therefore, in the present invention, under such a background, the water resistance and hardness of the coating film can be expressed from the initial stage after the formation of the coating film. Re-emulsifiable resin powder composition with excellent anti-skinning property that prevents the tension state and can be patterned on the coated surface with a trowel etc. after coating, an aqueous emulsion obtained by re-emulsifying it, and using the same The purpose is to provide architectural finishes.

  However, as a result of intensive studies in view of such circumstances, the present inventor prepared an ethylenically unsaturated monomer component containing a large amount of hydrophobic monomer, polymerized it to produce a synthetic resin emulsion, and dried it. It was found that the re-emulsified resin powder was effective. As a result of further research based on this knowledge, the present inventor has found that the desired object can be achieved by including a condensed phosphate and a crosslinking agent in the powder, and the present invention has been completed.

That is, the gist of the present invention is a re-emulsifiable resin powder composition containing the re-emulsifiable resin powder (I), the condensed phosphate (II), and the crosslinking agent (III), and The emulsifiable resin powder (I) is a synthetic resin obtained by polymerizing an ethylenically unsaturated monomer component containing 30% by weight or more of a hydrophobic monomer having a solubility in water at 20 ° C. of 0.3% by weight or less. The present invention relates to a re-emulsifiable resin powder composition characterized by being a dry product of an emulsion in which a re-emulsification improver (B) is further added to an emulsion (A) stabilized by an alcohol resin (a). It is.

  The present invention also relates to an aqueous emulsion obtained by re-emulsifying the re-emulsifiable resin powder composition, further comprising the re-emulsifiable resin powder composition or the aqueous emulsion. It is related to the architectural finish coating material.

The re-emulsifiable resin powder composition of the present invention is a re-emulsifiable resin powder composition containing the re-emulsifiable resin powder (I), the condensed phosphate (II), and the crosslinking agent (III), An emulsion (A) in which the re-emulsifiable resin powder (I) is a dispersion-stabilized synthetic resin obtained by polymerizing an ethylenically unsaturated monomer component containing a hydrophobic monomer with a polyvinyl alcohol resin (a ). Furthermore, since it is a dry product of an emulsion containing the re-emulsification improver (B), the water resistance and hardness of the coating film can be expressed from the initial stage after the coating film is formed, and in addition, the durable adhesion of the coating film It has excellent properties, and has an excellent anti-skinning effect that prevents the coating surface from being skinned and allows the coating surface to be patterned with a trowel after coating. This re-emulsifiable resin powder composition and the aqueous emulsion obtained by re-emulsifying this in water are particularly suitable for use in architectural finishing coating materials and powder coatings, and also for mixing hydraulic materials such as cement and gypsum. It is also useful for various uses such as adhesives, wood parts or wood, and adhesives such as paper.

  The present invention is described in detail below.

The re-emulsifiable resin powder composition of the present invention is an emulsion in which a synthetic resin obtained by polymerizing an ethylenically unsaturated monomer component containing 30% by weight or more of a hydrophobic monomer is dispersed and stabilized with a polyvinyl alcohol resin (a). In (A) , the re-emulsifiable resin powder (I), which is a dried product of the emulsion further containing the re-emulsification improver (B), contains the condensed phosphate (II) and the crosslinking agent (III). A re-emulsifiable resin powder composition. Hereinafter, the re-emulsifiable resin powder (I), the condensed phosphate (II), and the crosslinking agent (III) will be described in order.

  Here, the re-emulsifiable resin powder refers to a powder capable of generating an emulsion when re-emulsified in an aqueous medium such as water.

<< 1. Re-emulsifiable resin powder (I) >>
The re-emulsifiable resin powder (I) according to the present invention comprises, as described above, an emulsion (A) obtained by dispersing and stabilizing a synthetic resin with a polyvinyl alcohol resin (a ) , and further a re-emulsification improver (B). the a dried product of an emulsion which contains, this error Marujon (a) (hereinafter sometimes referred to as "synthetic resin emulsion (a)") is one obtained by emulsion polymerization of an ethylenically unsaturated monomer component is there. First, each material component (constituent material) which comprises this synthetic resin emulsion (A) is demonstrated.

<1-1. Constituent Material of Synthetic Resin Emulsion (A) >
(A. Ethylenically unsaturated monomer component)
The ethylenically unsaturated monomer component constituting the synthetic resin emulsion (A) in the present invention comprises at least 30% by weight of a hydrophobic monomer. This hydrophobic monomer will be described next.

(I. Hydrophobic monomer)
The hydrophobic monomers of interest in the present invention, an ethylenically unsaturated monomer component, Ri substantially insoluble monomers der in water, is 0.3 wt% or less solubility 20 ° C. water. The monomer is preferably 0.2% by weight or less. This hydrophobic monomer is usually selected from acrylic monomers, styrene monomers, and vinyl monomers.

  Examples of the acrylic monomer include n-butyl (meth) acrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) ) Alkyl (meth) acrylates having an alkyl group such as acrylate and stearyl (meth) acrylate having 4 or more carbon atoms, preferably 6 to 18; aromatic (meth) acrylates such as phenoxy acrylate; trifluoroethyl methacrylate and the like These can be used alone or in combination of two or more. Among these, 2-ethylhexyl acrylate and n-butyl acrylate are preferable. Here, (meth) acrylate means acrylate or methacrylate.

Examples of the solubility of the monomer in water at 20 ° C. are as follows.
n-butyl acrylate: 0.2% by weight
n-butyl methacrylate: 0.04% by weight
i-Butyl methacrylate: 0.04% by weight
t-Butyl methacrylate: 0.05% by weight
2-ethylhexyl acrylate: 0.01% by weight
2-ethylhexyl methacrylate: 0.01 wt% or less Cyclohexyl methacrylate: 0.01 wt% or less Lauryl methacrylate: 0.01 wt% or less Stearyl methacrylate: 0.01 wt% or less Trifluoroethyl methacrylate: 0.04 wt%

  Examples of the styrenic monomer include styrene and α-methylstyrene. These may be used alone or in combination of two or more. Among these, styrene is preferable.

  Furthermore, examples of the vinyl monomer include vinyl laurate, vinyl stearate, vinyl versatate (solubility in water at 20 ° C .: 0.1% by weight or less), and these are used alone or in combination of two kinds. The above can be used together.

  Moreover, according to the physical property etc. of re-emulsifiable resin powder, the said hydrophobic monomer can be used individually or in combination of 2 or more types.

  In the present invention, the method for determining the solubility in water at 20 ° C. is as follows. First, 20 ml of the target monomer and 100 ml of water are placed in a 200 ml separatory funnel, and stirred at room temperature (23-25 ° C.) for 10 minutes once, with an interval of 10 minutes for each stirring. However, it is performed three times, and is left standing for 20 hours in a constant temperature room at 20 ° C. Thereafter, the lower aqueous layer separated from the monomer is removed by opening the stopcock at the lower part of the separatory funnel, and quantified by gas chromatography (hydrogen flame ionization detector).

  In the present invention, since the purpose is to produce an emulsion having excellent water resistance when a coating film is formed, the content of the hydrophobic monomer needs to be relatively high. Is 30% by weight or more based on the total ethylenically unsaturated monomer component, preferably 40 to 100% by weight, more preferably 50 to 100% by weight. If the amount of the hydrophobic monomer used is too small, the water resistance and the initial development of hardness of the desired coating film and the durable adhesion of the coating film will be insufficient. Moreover, the tendency to be inferior to early drying property or toughness of a coating film may be seen.

  Here, the initial expression of the water resistance of the coating film means, for example, that even if the weather suddenly changes and rains after coating, This indicates that the coated surface is finished to the extent that it is not affected.The initial expression of coating film hardness refers to the surface of the coating film when it enters the next work process after coating. This indicates that the coated surface is finished to the extent that it is not affected.

  The ethylenically unsaturated monomer component used in the present invention can contain an ethylenically unsaturated monomer copolymerizable with the hydrophobic monomer (hereinafter sometimes abbreviated as “copolymerizable monomer”). Next, the copolymerizable monomer will be described.

(Ii. Copolymerizable monomer)
The copolymerizable monomer is not particularly limited, and examples thereof include (meth) acrylic monomers having 3 or less carbon atoms in alkyl groups such as methyl (meth) acrylate and ethyl (meth) acrylate; vinyl acetate and vinyl propionate Vinyl monomers such as ethylene; olefin monomers such as ethylene; halogenated olefin monomers such as vinyl chloride; (meth) acrylamide, N, N-dimethylacrylamide, t-butylacrylamide, 2-acrylamido-2-methylpropanesulfonic acid Acrylamide monomers such as nitrile monomers such as (meth) acrylonitrile; Vinyl ether monomers such as methyl vinyl ether; Ethylenically unsaturated carboxylic acids such as (meth) acrylic acid and (anhydrous) itaconic acid; Such as it is possible to increase the system monomer. Among these, a (meth) acrylic monomer having an alkyl group with 3 or less carbon atoms is preferable.

  Further, in the present invention, particularly when used as an architectural finishing coating material for exteriors and powder coatings, the above-mentioned copolymerization is carried out at the time of emulsion polymerization from the point that the toughness of the coating film and the adhesion to the ground are obtained. Among the polymerizable monomers, it is preferable to copolymerize an ethylenically unsaturated monomer containing a specific functional group (hereinafter sometimes abbreviated as “functional monomer”).

  The functional monomer is at least one selected from the group consisting of allyl group-containing monomers, glycidyl group-containing monomers, hydrolyzable silyl group-containing monomers, acetoacetyl group-containing monomers, vinyl group-containing monomers, and carbonyl group-containing monomers. It is preferable that

  Examples of the allyl group-containing monomer include monomers having two or more allyl groups, such as triallyloxyethylene, diallyl maleate, triallyl cyanurate, triallyl isocyanurate, tetraallyloxyethane, diallyl phthalate, and allyl glycidyl ether. And allyl acetate. Among these, allyl glycidyl ether is preferable from the viewpoint of adhesion to the base.

  Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate and 3,4-epoxycyclohexyl (meth) acrylate. Among these, glycidyl (meth) acrylate is preferable from the viewpoint of improving the water resistance and toughness of the coating film.

  Examples of the hydrolyzable silyl group-containing monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, vinylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxy. Examples thereof include propylmethyldimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltriethoxysilane, and γ-methacryloxypropylmethyldiethoxysilane. Among these, vinyltrimethoxysilane is preferable from the viewpoint of adhesion to inorganic materials.

  Examples of the acetoacetyl group-containing monomer include acetoacetate vinyl ester, acetoacetate allyl ester, diacetoacetate allyl ester, acetoacetoxyethyl (meth) acrylate, acetoacetoxyethyl crotonate, acetoacetoxypropyl (meth) acrylate, acetoacetoxy Examples thereof include propyl crotonate and 2-cyanoacetoacetoxyethyl (meth) acrylate. Among these, acetoacetoxyethyl (meth) acrylate is preferable from the viewpoint of improving the water resistance of building finish coating materials and powder paints and adhering to the foundation.

  The vinyl group-containing monomer is preferably a monomer having two or more vinyl groups in the molecular structure. For example, divinylbenzene, ethylene glycol di (meth) acrylate, 1,2-propylene glycol di (meth) acrylate 1,3-propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (Meth) acrylate, allyl (meth) acrylate and the like.

  Examples of the carbonyl group-containing monomer include diacetone acrylamide. Diacetone acrylamide is preferable from the viewpoints of improving the water resistance and toughness of architectural finishing coating materials and powder coating materials, and adhering to the substrate.

  According to a preferred embodiment of the present invention, as a functional monomer, a hydrolyzable silyl group-containing monomer, an acetoacetate is used from the viewpoint of the toughness of the coating film and the adhesion to the substrate for exterior building finish coating materials and powder coatings. Monomers selected from the group consisting of acetyl group-containing monomers and carbonyl group-containing monomers are preferred, and carbonyl group-containing monomers are more preferred.

  The amount of the functional monomer used is preferably 0.05 to 10% by weight, more preferably 0.5 to 7% by weight, and more preferably 1 to 5% by weight based on the total ethylenically unsaturated monomer component. More preferably. If the amount is too small, there is a tendency that the toughness of the coating film and the adhesion to the substrate are insufficient, and if the amount is too large, poor polymerization or re-emulsification tends to be reduced.

  The ethylenically unsaturated monomer component is emulsion-polymerized, and at the time of this emulsion polymerization, a protective colloid agent (dispersion stabilizer) for emulsion polymerization may be added together with the ethylenically unsaturated monomer component to stabilize the dispersion. To preferred. Next, the protective colloid agent will be described.

(B. Protective colloid agent)
Protective colloid in the present invention (dispersion stabilizer) is to use the port polyvinyl alcohol resin (a).

  As the polyvinyl alcohol-based resin (a), a saponified product obtained by saponifying a polyvinyl acetate solution with an alkali or an acid or a derivative thereof is used. Further, vinyl acetate can be copolymerized with vinyl acetate. A saponified product obtained by saponifying a copolymer with an isomer can be used as long as the object of the present invention is not impaired.

  Examples of the monomer copolymerizable with vinyl acetate include olefins (ethylene, propylene, α-butene, α-octene, α-dodecene, α-octadecene, etc.), unsaturated monocarboxylic acids (acrylic acid, methacrylic acid). Acid, crotonic acid, etc.) or esters or salts thereof, unsaturated polycarboxylic acids (maleic acid, fumaric acid, itaconic acid, etc.) or partial or complete esters or salts or anhydrides thereof, unsaturated sulfonic acids (ethylene sulfone) Acid, allyl sulfonic acid, methallyl sulfonic acid, etc.) or salts thereof, amides (acrylamide, methacrylamide, etc.), nitriles (acrylonitrile, methacrylonitrile, etc.), vinyl ether, vinyl ketone, vinyl chloride and the like.

  The saponification is performed by dissolving a polymer such as polyvinyl acetate in an alcohol or hydrous alcohol and using an alkali catalyst or an acid catalyst. Examples of the alcohol used for the saponification include saturated alcohols having 1 to 6 carbon atoms such as methanol, ethanol, propanol, and tert-butanol. Among these, methanol is particularly preferably used. The concentration of the polymer in the alcohol is appropriately selected depending on the viscosity of the system, but is usually selected from the range of 10 to 60% by weight.

  Examples of the catalyst used for the saponification include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, potassium methylate and lithium methylate, and alkali catalysts such as alcoholate. An acid catalyst such as sulfuric acid, hydrochloric acid, nitric acid, metasulfonic acid, zeolite, and cation exchange resin. The amount of the saponification catalyst used is appropriately selected depending on the saponification method, the target degree of saponification, and the like. When an alkali catalyst is used, it is usually 0.1 to 1 mol of the polyvinyl alcohol-based resin. It is preferably 30 mmol, more preferably 2 to 17 mmol. The reaction temperature for the saponification reaction is not particularly limited, but is preferably 10 to 60 ° C, more preferably 20 to 50 ° C.

  As the polyvinyl alcohol resin (a) used in the present invention, those having a saponification degree of 80 mol% or more, preferably 85 mol% or more, and an average polymerization degree of 10 to 3000, preferably 20 to 2500 are used.

  In the present invention, the degree of saponification and the average degree of polymerization can be determined according to JIS K 6726.

  In the present invention, among the above-mentioned polyvinyl alcohol resins (a), various modified polyvinyl alcohol resins can be used from the viewpoint of further enhancement of functionality, and in particular, graft properties are improved and protection is achieved. From the viewpoint of improving colloidal physical properties, “functional group-containing polyvinyl alcohol resin (a1) having active hydrogen” is preferable.

(I. Functional group-containing polyvinyl alcohol resin (a1) having active hydrogen)
The average polymerization degree of the functional group-containing polyvinyl alcohol resin (a1) having active hydrogen is preferably 20 to 2500, more preferably 200 to 800, and still more preferably 200 to 500. If the average degree of polymerization is too small, there is a tendency not to have protective colloid properties, and if the average degree of polymerization is too small, it is not easy to industrially produce a polyvinyl alcohol-based resin. On the other hand, if the average degree of polymerization is too large, the viscosity of the emulsion tends to be too high, or the polymerization stability of the emulsion tends to decrease.

  Furthermore, the saponification degree of the functional group-containing polyvinyl alcohol resin (a1) having active hydrogen is preferably 90 mol% or more, more preferably 95 mol% or more, and still more preferably 97 to 99.8 mol%. It is. If the degree of saponification is too small, the stability of the emulsion during polymerization tends to be extremely reduced, making it difficult to obtain the desired aqueous emulsion.

  The modification amount of the functional group having active hydrogen is usually preferably 0.01 to 15 mol%, particularly preferably 0.01 to 10 mol%, more preferably 0.03 to 5 mol%, still more preferably. It is 0.03 to 2 mol%, most preferably 0.03 to 1 mol%. If the amount of modification is too small, the protective colloid properties will decrease and polymerization stability will decrease, and if the solid content is high, gelation will occur during the reaction, and if it is too high, the polymerization stability of the emulsion will decrease. Tend.

  Examples of the functional group having active hydrogen include an acetoacetyl group, diacetone acrylamide group, amino group, mercapto group, etc. Among these, the point that the polymerization stability can be improved, the re-emulsification of the resin powder An acetoacetyl group-modified polyvinyl alcohol-based resin is most preferred because it can improve the water resistance and improve the water resistance of the film because the graft ratio to the synthetic resin is high.

  Examples of the method for introducing an acetoacetyl group into a polyvinyl alcohol resin include a method of reacting a polyvinyl alcohol resin with diketene, a method of reacting a polyvinyl alcohol resin with acetoacetate, etc., but the production process is simplified. In view of obtaining a high-quality acetoacetyl group-modified polyvinyl alcohol resin, it is preferable to produce it by a method of reacting a polyvinyl alcohol resin with diketene. Furthermore, a method of reacting a polyvinyl alcohol-based resin with diketene is also preferable in that the amount of diketene used is small and the reaction yield of diketene is improved.

  When the functional group-containing polyvinyl alcohol resin (a1) having active hydrogen is an acetoacetyl group-modified polyvinyl alcohol resin, the degree of acetoacetylation is preferably 0.01 to 10 mol%, more preferably 0.1 to 0.1 mol%. 5 mol%, more preferably 0.3 to 3 mol%, particularly preferably 0.3 to 2 mol%. If the degree of acetoacetylation is too small, the water resistance and mechanical strength of the coating film tend to be insufficient, and if too large, the polymerization stability tends to decrease.

  Furthermore, it is preferable that the acetoacetyl groups present on the polyvinyl alcohol molecule are relatively randomly arranged in the molecule rather than those arranged in a block form in a certain region of the molecule.

The saponification degree of the acetoacetyl group-modified polyvinyl alcohol resin is preferably 90 mol% or more, particularly 95 mol% or more, and more preferably 97 to 99.8 mol%. If the degree of saponification is too small, it becomes difficult for the polymerization to proceed stably, and even if the polymerization is completed, the storage stability of the synthetic resin emulsion (A) tends to be poor. On the other hand, if it is too large, the polymerization stability is deteriorated and gelation may occur during the polymerization, and even if the polymerization is completed, it tends to be difficult to re-emulsify.

  The average degree of polymerization of the acetoacetyl group-modified polyvinyl alcohol resin is preferably 50 to 2000, and more preferably 200 to 600. If the average degree of polymerization is too small, the protective colloid ability at the time of emulsion polymerization is insufficient and the polymerization tends not to proceed stably. If it is too large, the reaction system becomes unstable due to thickening at the time of polymerization and re-emulsification Tends to decrease.

  The particle size of the acetoacetyl group-modified polyvinyl alcohol resin is preferably 20 to 5000 μm, and more preferably 44 to 1680 μm. If the particle size is too small, the particles are likely to be fused by heat of reaction, and further, post-treatment such as washing and drying tends to be difficult.If the particle size is increased, polyvinyl alcohol resin particles and diketene used for the acetoacetylation reaction Contact tends to be non-uniform and the reaction rate of diketene tends to decrease.

  The particle size of the acetoacetyl group-modified polyvinyl alcohol resin can be adjusted by adjusting with a standard sieve or by air classification after the production of the polyvinyl alcohol resin.

As a method of introducing a diacetone acrylamide group into a polyvinyl alcohol resin, it can be obtained by copolymerization of diacetone acrylamide and vinyl acetate and then saponification. The copolymerization of diacetone acrylamide and vinyl acetate is not particularly limited, but the polymerization rate is adjusted according to the HANNA formula (reactivity ratio: diacetone acrylamide; r1 = 14.8, vinyl acetate; r2 = 0.06). Accordingly, it is preferable to charge diacetone acrylamide. A uniform modification of diacetone acrylamide makes it easy to obtain a polyvinyl alcohol-based resin having a low acetoxy group (CH ₃ COO—) blocking property.

  The saponification is then performed in the same manner as in the production of the acetoacetyl group-modified polyvinyl alcohol resin.

  The diacetone acrylamide group content of the thus obtained diacetone acrylamide group-modified polyvinyl alcohol resin is preferably 0.1 to 15 mol%, more preferably 0.5 to 10 mol%, still more preferably. When the content is too small, the effect of the present invention tends not to be sufficiently obtained. On the other hand, when the content is too large, the water solubility of the polyvinyl alcohol-based resin decreases or an emulsion is obtained. There is a tendency for the polymerization stability to decrease (the number of coarse particles increases, the emulsion viscosity becomes too high, etc.).

  As a method for introducing a mercapto group into a polyvinyl alcohol-based resin, it can be obtained by saponification after polymerization in the presence of a compound having a mercapto group as a chain transfer agent during polymerization of vinyl acetate. Examples of the compound having a mercapto group include compounds represented by the following general formula (1), and examples thereof include organic thiolic acids such as thioacetic acid, thiopropionic acid, thiobutyric acid, and thiovaleric acid.

R ¹ —CO—SH (1)
(Wherein R ¹ is an alkyl group having 2 to 15 carbon atoms)

  In polymerizing vinyl acetate using a compound having a mercapto group as described above as a chain transfer agent, according to the following general formula (2), a chain transfer agent having a mercapto group corresponding to the desired degree of polymerization (for example, The initial charge amount of (organic thiolic acid) is determined and polymerization is started, and then the chain transfer agent is additionally charged according to the consumption rate of the chain transfer agent according to the following general formula (3).

1 / P = Cm + Cs ([S] / [M]) + Cx ([X] / [M]) (2)
Additional charge amount = Cx ([X] / [M]) · Rp (3)
(Where P is the degree of polymerization, Cm is the chain transfer constant for the monomer, Cs is the chain transfer constant for the solvent, Cx is the chain transfer constant of the chain transfer agent, [S] is the solvent concentration (mol / L), [M] Is the monomer concentration (mol / L) and Rp is the polymerization rate (mol / L / sec).

  Next, saponification is carried out, but the saponification may be carried out in the same manner as in the production of the acetoacetyl group-containing polyvinyl alcohol resin.

  In the present invention, among the above-mentioned polyvinyl alcohol resins (a), in particular, from the viewpoint of increase in solid content of emulsion, ease of polymerization, etc., “having a 1,2-diol bond in the side chain”. The polyvinyl alcohol resin (a2) ”is preferable.

(Ii. Polyvinyl alcohol resin (a2) having a 1,2-diol bond in the side chain)
The polyvinyl alcohol resin (a2) having a 1,2-diol bond in this side chain is, for example, (a) a method of saponifying a copolymer of vinyl acetate and 3,4-diacetoxy-1-butene, A) a method of saponifying and decarboxylating a copolymer of vinyl acetate and vinyl ethylene carbonate; and (c) a copolymer of vinyl acetate and 2,2-dialkyl-4-vinyl-1,3-dioxolane. And (d) a method of saponifying a copolymer of vinyl acetate and glyceryl monoallyl ether.

  The saponification degree of the polyvinyl alcohol-based resin (a2) having a 1,2-diol bond in the side chain is preferably 85 mol% or more, more preferably 90 mol% or more, and particularly preferably 95 to 99.8. Mol%. If the degree of saponification is too small, the stability of the emulsion during polymerization tends to decrease, making it difficult to obtain the desired aqueous emulsion.

  Moreover, it is preferable that the 1, 2- diol bond amount of the side chain of this polyvinyl alcohol-type resin (a2) is 1-15 mol%, More preferably, it is 1-12 mol%, More preferably, it is 2-10 mol. %, Particularly preferably 2 to 8 mol%. If the amount of 1,2-diol bond is too small, the mechanical stability of the emulsion and the water resistance of the film tend to be lowered, and if too large, the stability during polymerization is lowered, and a stable emulsion having a high nonvolatile content. Tends to be difficult to obtain.

  Furthermore, the average degree of polymerization of the polyvinyl alcohol resin (a2) having a 1,2-diol bond in the side chain is preferably 50 to 2500, more preferably 100 to 1700, still more preferably 100 to 1000, and particularly preferably 200. ~ 500. If the degree of polymerization is too small, it tends to be difficult to industrially produce a polyvinyl alcohol-based resin. If it is too large, the viscosity of the emulsion tends to be too high, or the polymerization stability of the emulsion tends to decrease.

  Moreover, you may use together "polyvinyl alcohol-type resin (a3) containing an anionic group" as polyvinyl alcohol-type resin (a) used by this invention. Examples of the anionic group include a sulfonic acid group, a carboxylic acid group, and a phosphoric acid group. Among these, sulfonic acid can be obtained stably and strongly regardless of the pH in the emulsion. It is preferably a group.

  In the present invention, as the polyvinyl alcohol-based resin (a), the polyvinyl alcohol-based resin can be used alone or in admixture of two or more, but the non-modified type portion other than the polyvinyl alcohol-based resin or Completely saponified polyvinyl alcohol or the like can be used in combination as long as the object of the present invention is not impaired.

  In this invention, it is preferable that the usage-amount of protective colloid agents (dispersion stabilizer), such as the said polyvinyl alcohol-type resin (a), is 3-20 weight part with respect to 100 weight part of all the copolymerization monomer components. More preferably, it is 4 to 10 parts by weight. If the amount is too small, the amount of protective colloid at the time of emulsion polymerization will be insufficient, and the polymerization stability tends to be poor. If the amount is too large, re-emulsification will be good, but there will be many water-soluble components in the powder. Thus, there is a tendency that the water resistance in the application is lowered.

In addition, as the protective colloid agent for the polyvinyl alcohol resin (a ), an aqueous solution using an aqueous medium is usually used in the course of emulsion polymerization. Here, the aqueous medium refers to water or an alcoholic solvent mainly composed of water, preferably water.

Although this amount of polyvinyl alcohol resins of a protective colloid agent in an aqueous solution (nonvolatile content) is not particularly limited, from the viewpoint of ease of handling, it is preferably 5 to 30 wt%.

  Furthermore, in the present invention, among the protective colloid agents, at least a part of the polyvinyl alcohol-based resin (a) is grafted to the synthetic resin in the synthetic resin emulsion (A). The synthetic resin emulsion (A) itself is preferable in terms of storage stability and variation in evaluation in adhesiveness measurement. This graft is caused by the functional group contained in the polyvinyl alcohol resin.

  When the polyvinyl alcohol-based resin (a) is grafted on the synthetic resin, the value (W) represented by the following formula (4) is preferably 50% by weight or more. More preferably, it is 60 to 95 weight%, More preferably, it is 65 to 85 weight%. This value is a measure of the degree of grafting, and if this value is too low, the protective colloid action during emulsion polymerization is lowered, the polymerization stability is lowered, and in addition, the miscibility with fillers is reduced. There is a tendency to decrease. Conversely, if it is too high, the degree of grafting is high, and the emulsion tends to thicken or gel during polymerization.

The value (W) of equation (4) is calculated as follows. That is, the target emulsion or the like is dried at 40 ° C. for 16 hours to form a film having a thickness of about 0.5 mm, and left for 2 days at 23 ° C. and 65% RH. The film is extracted in boiling water for 8 hours and then extracted in acetone for 8 hours to remove ungrafted resin and the like. In this case, the absolute dry weight of the film before extraction is w ₁ (g), and the absolute dry weight of the film after extraction is w ₂ (g).

W (% by weight) = (w ₂ ) / (w ₁ ) × 100 (4)
(W ₁ : absolute dry weight of film before extraction (g), w ₂ : absolute dry weight of film after extraction (g))
The absolute dry weight of the film before extraction (w ₁ ) is obtained by previously drying a sample different from the extraction test sample at 105 ° C. for 1 hour and calculating its weight. The absolute dry weight of the film after extraction (W ₂ ) is the weight when the sample after extraction is dried at 105 ° C. for 1 hour. Then, calculation of the weight of these w ₁ and w _2, because those using a different sample each, in order to handling and under the same conditions, and corrected by the volatile content percentage caused by drying of both samples, The absolute dry weight of the film of both samples was calculated.

  As a method of adjusting the value (W) of the above formula (4) to 50% by weight or more, the emulsion polymerization temperature is made slightly higher than before, or a very small amount of reducing agent (persulfate used as a polymerization catalyst) For example, a method of using acidic sodium sulfite or the like in combination.

In the present invention, as described above, the synthetic resin emulsion (A) is obtained by emulsion polymerization of the ethylenically unsaturated monomer component. In this polymerization, in addition to the ethylenically unsaturated monomer component and the protective colloid agent, other components can be further used as necessary.

(C. Other ingredients)
Such other components are not particularly limited as long as the properties as the re-emulsifiable resin powder (I) are not deteriorated, and can be appropriately selected according to the purpose. Examples of other components include a polymerization initiator, a polymerization regulator, an auxiliary emulsifier, a plasticizer, and a film forming aid.

(I. Polymerization initiator)
Any polymerization initiator can be used without particular limitation as long as it can be used for ordinary emulsion polymerization. For example, inorganic peroxides such as potassium persulfate, sodium persulfate, and ammonium persulfate; organic peroxides, azo initiators Agents, peroxides such as hydrogen peroxide and butyl peroxide; and redox polymerization initiators combining these with reducing agents such as acidic sodium sulfite and L-ascorbic acid. These are used in combination of two or more. May be. Among these, inorganic oxides, particularly ammonium persulfate and the like, are not adversely affected by the effect of the crosslinking agent which affects the water resistance and initial development properties of the coating film, and the properties of early drying properties, and are easy to carry out emulsion polymerization. Potassium persulfate is preferred.

(Ii. Polymerization regulator)
As a polymerization regulator, it can select suitably from well-known things. Examples of such a polymerization regulator include a chain transfer agent and a buffer.

  Here, 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; and dodecyl mercaptan, lauryl mercaptan, and normal mercaptan. And mercaptans such as thioglycolic acid, octyl thioglycolate, and thioglycerol. Two or more of these may be used in combination.

  Polymerization can be performed stably by using a chain transfer agent, but the degree of polymerization of the synthetic resin is lowered, and as a result, the initial appearance of water resistance and hardness, toughness, and durable adhesion of the resulting coating film. When using a chain transfer agent, it is desirable to reduce the amount used as much as possible.

  Here, examples of the buffer include sodium acetate, ammonium acetate, dibasic sodium phosphate, and the like. Two or more of these may be used in combination.

(Iii. Auxiliary emulsifier)
Any auxiliary emulsifier can be used as long as it is known to those skilled in the art as being usable for emulsion polymerization. Accordingly, the auxiliary emulsifier is appropriately selected from known ones such as anionic, cationic, and nonionic surfactants, water-soluble polymers having protective colloid ability other than polyvinyl alcohol, and water-soluble oligomers. be able to.

  Preferred specific examples of the surfactant include, for example, anionic surfactants such as sodium lauryl sulfate and sodium dodecylbenzenesulfonate, and nonions such as those having a pluronic structure and those having a polyoxyethylene structure. Surfactants. A reactive surfactant having a radical polymerizable unsaturated bond in the structure can also be used as the surfactant.

  By using an emulsifier, the emulsion polymerization can proceed smoothly, the polymerization can be easily controlled, and the generation of coarse particles and block-like substances generated during the polymerization can be suppressed. If it is used as a large amount, the particles may be agglomerated at the time of drying, and the re-emulsification property may be lowered. Therefore, when a surfactant is used as an emulsifier, the amount used is preferably an auxiliary amount with respect to the polyvinyl alcohol resin, that is, as small as possible.

  Examples of water-soluble polymers having protective colloid ability other than polyvinyl alcohol resins include hydroxyethyl cellulose, polyvinyl pyrrolidone, methyl cellulose and the like. These are effective in changing the viscosity when the obtained re-emulsifiable resin powder is re-emulsified and used. However, since the re-emulsification property of the re-emulsifiable resin powder may be reduced depending on the amount of use, it may be used in an amount that does not reduce the re-emulsification property of the re-emulsification resin powder. desirable.

  As the water-soluble oligomer, for example, a polymer or copolymer having a hydrophilic group such as a sulfonic acid group, a carboxyl group, a hydroxyl group, and an alkylene glycol group and having a degree of polymerization of about 10 to 500 is preferably exemplified.

  Specific examples of water-soluble oligomers include, for example, amide copolymers such as 2-methacrylamide-2-methylpropanesulfonic acid copolymer, sodium methacrylate-4-styrenesulfonate copolymer, styrene-maleic acid copolymer. Examples thereof include a polymer, a melamine sulfonic acid formaldehyde condensate, and a poly (meth) acrylate. Specific examples include monomers having a sulfonic acid group, a carboxyl group, a hydroxyl group, an alkylene glycol group, and water-soluble oligomers obtained by previously copolymerizing a radical polymerizable reactive emulsifier alone or with other monomers. It is done.

  In the present invention, among these, 2-methacrylamide-2-methylpropanesulfonic acid copolymer, methacrylic acid, in that re-emulsifying property can be imparted, and in terms of mixing stability with pigments and fillers such as calcium carbonate. Sodium-4-styrene sulfonate copolymer is preferred. As the water-soluble oligomer, those previously polymerized before starting the emulsion polymerization may be used, or commercially available products may be used. Two or more of these may be used in combination.

(Iv. Plasticizer and film-forming aid)
Moreover, as a plasticizer, the adipate type plasticizer, the phthalic acid type plasticizer, the phosphoric acid type plasticizer, etc. which are generally used for paints and adhesives can be used. A film-forming aid can also be used.

  The amount of these other components used is not particularly limited as long as the object of the present invention is not impaired, and can be appropriately selected according to the object.

Next, the production of the synthetic resin emulsion (A) according to the present invention will be described.

<1-2. Production of synthetic resin emulsion (A)>
As described above, the synthetic resin emulsion (A) in the present invention is obtained by emulsion polymerization of an ethylenically unsaturated monomer component containing 30% by weight or more of a hydrophobic monomer. In this emulsion polymerization, from the viewpoint of stabilizing the dispersion of the synthetic resin, a protective colloid agent, preferably a polyvinyl alcohol resin (a), is usually used.

(A. Emulsion polymerization)
The method for emulsion polymerization is not particularly limited. For example, water and a protective colloid agent of polyvinyl alcohol resin (a ) are charged into a reaction can, and the ethylenically unsaturated monomer component and the polymerization initiator are dropped by heating. The monomer dropping type emulsion polymerization method; and the emulsion monomer dropping type emulsion polymerization method in which the dropping monomer is dispersed and emulsified in advance with a protective colloid agent and water and then dropped. From the standpoint of properties and the like, the monomer dropping type emulsion polymerization method is convenient.

  Usually, the emulsion polymerization is carried out using other components as described above such as a polymerization initiator, a polymerization regulator, an auxiliary emulsifier, etc., if necessary, in addition to the protective colloid agent and the ethylenically unsaturated monomer component. The polymerization reaction conditions are not particularly limited and can be appropriately selected according to the type and purpose of the ethylenically unsaturated monomer component.

The emulsion polymerization process will be described more specifically. However, it is not limited to this.
First, water, protective colloid and, if necessary, auxiliary emulsifier are charged into a reaction can, and this is heated (for example, 65 to 90 ° C.). To carry out the initial polymerization. Next, the remaining ethylenically unsaturated monomer component is added to the reaction can in one batch or dropwise, and the polymerization is allowed to proceed while further adding a polymerization initiator as necessary. When it is determined that the polymerization reaction is completed, the reaction can is cooled, and the target synthetic resin emulsion (A) can be taken out.

(B. Characteristics of synthetic resin emulsion (A))
The synthetic resin emulsion (A) obtained from the emulsion polymerization is typically uniform milky white, and the average particle size of the synthetic resin in the synthetic resin emulsion (A) is 0.2 to 2.0 μm. It is preferable that the thickness is 0.3 to 1.5 μm.

  Here, the average particle diameter of the synthetic resin in the synthetic resin emulsion (A) is measured by a conventional method, for example, a laser analysis / scattering particle size distribution measuring apparatus “LA-910” (manufactured by Horiba, Ltd.). Can do.

  In addition, the glass transition temperature of the synthetic resin in the synthetic resin emulsion (A) is such that it has physical properties such as adhesion to the ground such as mortar and slate plate and toughness of the coating film for building finishing coating materials and powder coatings. Therefore, it is preferably −35 to 20 ° C., more preferably −25 to 10 ° C., and further preferably −20 to 0 ° C. If the glass transition temperature is too low, the adhesion of the coating to the substrate and the toughness of the coating tend to be reduced. If it is too high, a plasticizer such as dibutyl phthalate is added to lower the film-forming temperature of the emulsion. As a result, the adhesive strength and toughness of the coating film with respect to the substrate tend to decrease.

  In the present invention, the glass transition temperature in the synthetic resin is a value calculated by the Fox equation based on the ethylenically unsaturated monomer component.

(C. Additive to the synthetic resin emulsion (A) )
In this invention, you may further add various additives to the said synthetic resin emulsion (A) as needed. Examples of such additives include water-soluble additives, organic pigments, inorganic pigments, dispersants such as pigments and fillers, thickeners, pH adjusters, preservatives, water repellents, and antioxidants. It is done. When these are powders / powder, the synthetic resin emulsion (A) may be added to the re-emulsifiable resin powder (I) obtained by drying, preferably spray drying.

(I. Water-soluble additive)
Water-soluble additives include hydroxyethyl cellulose, methyl cellulose, starch derivatives, polyvinyl pyrrolidone, polyethylene oxide, water-soluble alkyd resins, water-soluble phenol resins, water-soluble urea resins, water-soluble melamine resins, water-soluble additives, depending on the application of the resin powder. Water-soluble guanamine resin, water-soluble naphthalenesulfonic acid resin, water-soluble amino resin, water-soluble polyamide resin, water-soluble acrylic resin, water-soluble polycarboxylic acid resin, water-soluble polyester resin, water-soluble polyurethane resin, water-soluble polyol resin, and Examples include water-soluble epoxy resins.

  If it is a liquid water-soluble additive, it is preferable to add it to the synthetic resin emulsion (A) before spray-drying and then spray-dry to obtain a re-emulsifiable resin powder (I). If present, it may be dissolved once and then added to the synthetic resin emulsion (A) before spray drying, or may be added directly to the resin powder after spray drying. Two or more of these may be used in combination.

Further, when the re-emulsifiable resin powder composition of the present invention is dispersed / emulsified in water, the re-emulsification improver can be added to the synthetic resin emulsion (A) from the viewpoint that the re-emulsification property in water can be improved. (B) added.

(Ii. Re-emulsification improver (B))
Examples of the re-emulsification improver (B) include the water-soluble resins as described above, and the polyvinyl alcohol-based resin (b) is particularly preferable because the re-emulsification property to water can be further improved. .

  As said polyvinyl alcohol-type resin (b), you may use the thing similar to the polyvinyl alcohol-type resin (a) used as a protective colloid in the emulsion polymerization process, or a different thing.

  The saponification degree of the polyvinyl alcohol-based resin (b) is preferably 85 mol% or more, and more preferably 87 mol% or more. The upper limit of the saponification degree is not particularly limited, but is preferably 99.5 mol% or less, and more preferably 95 mol% or less. If the degree of saponification is too small, the water resistance tends to be remarkably lowered. If it is too large, the water resistance is improved, but the re-emulsification property to water tends to be deteriorated.

  The average degree of polymerization of the polyvinyl alcohol-based resin (b) is preferably 50 to 3000, more preferably 200 to 2000, and further preferably 300 to 600. If the average degree of polymerization is too small, the water resistance tends to decrease, and if it is too large, the re-emulsification property tends to decrease.

  A polyvinyl alcohol resin having a high average degree of polymerization close to the above upper limit value is difficult to use during polymerization because of its polymerization stability, but can be used without any particular problem after polymerization. However, those that are not easily soluble in water may adversely affect the re-emulsification properties, so it is desirable to use them after confirming the solubility in water in advance.

  The polyvinyl alcohol resin (b) is preferably at least one selected from the group consisting of an unmodified polyvinyl alcohol resin and a modified polyvinyl alcohol resin.

  Examples of the modified polyvinyl alcohol resin include a carboxylic acid modified polyvinyl alcohol resin, a sulfonic acid modified polyvinyl alcohol resin, an acetoacetyl group modified polyvinyl alcohol resin (b1), a mercapto group modified polyvinyl alcohol resin, and a side chain. Polyvinyl alcohol resin (b2) having a 1,2-diol bond, carbonyl group modified polyvinyl alcohol resin (b3), silanol group modified polyvinyl alcohol resin, amino group modified polyvinyl alcohol resin, cationic group modified polyvinyl alcohol resin And amide group-modified polyvinyl alcohol resins. Among these, acetoacetyl group-modified polyvinyl alcohol resin (b1), polyvinyl alcohol resin (b2) having a 1,2-diol bond in the side chain, and carbonyl group-modified polyvinyl alcohol resin (b3) are preferable.

  Further, when an acetoacetyl group-modified polyvinyl alcohol resin (b1), a polyvinyl alcohol resin (b2) having a 1,2-diol bond in the side chain, or a carbonyl group-modified polyvinyl alcohol resin (b3) is used, it will be described later. As the crosslinking agent (III), it is more preferable to contain a hydrazide compound capable of reacting with these.

  As such an acetoacetyl group-modified polyvinyl alcohol resin (b1), the degree of acetoacetylation is preferably 0.01 to 10 mol%, and particularly preferably 0.03 to 6 mol%. As a polyvinyl alcohol-type resin (b2) which has a 1, 2- diol bond in a side chain, it is preferable that the content of a 1, 2- diol bond is 1-15 mol%, and 3-12 mol% is especially preferable. . The carbonyl group-modified polyvinyl alcohol resin (b3) preferably has a carbonyl group modification degree of 0.5 to 10 mol%, particularly preferably 1 to 5 mol%.

  When a water-soluble resin is used as the re-emulsification improver (B), it is usually preferable to add the water-soluble resin to the synthetic resin emulsion (A) after emulsion polymerization and before drying as described above. However, you may add to re-emulsifiable resin powder (I) obtained by spray-drying according to the kind of water-soluble resin to be used, addition amount, and a use.

  The amount of the re-emulsification improver (B) used is preferably 2 to 30 parts by weight and 5 to 20 parts by weight with respect to 100 parts by weight of the solid content of the synthetic resin emulsion (A) before drying. It is more preferable. If the amount used is too small, the re-emulsification tends to be insufficient, and if too much, the water resistance of the re-emulsifiable resin powder tends to be insufficient.

  Next, production of the re-emulsifiable resin powder (I) according to the present invention will be described.

<1-3. Production of re-emulsified resin powder (I)>
In the present invention, the re-emulsifiable resin powder (I) can be obtained by drying, preferably spray drying, the synthetic resin emulsion (A) obtained by the emulsion polymerization.

  The method for drying the synthetic resin emulsion (A) is not particularly limited, and examples thereof include spray drying, freeze drying, and hot air drying after coagulation. Among these, spray drying is preferable from the viewpoint of production cost and energy saving.

  In the case of the spray drying, there is no particular limitation on the spraying format, and for example, it can be carried out by a disc type, nozzle type or the like. Examples of the heat source for spray drying include hot air and heated steam. The conditions for spray drying can be appropriately selected according to the size and type of the spray dryer, the solid content of the aqueous emulsion, the viscosity, the flow rate, and the like. The temperature of spray drying is usually about 80 to 150 ° C.

The spray drying process will be described with further specific examples. First, the solid content in the synthetic resin emulsion (A) is adjusted, and this is continuously supplied from the nozzle of the spray dryer, and the mist is heated with warm air. Dry to powder. In some cases, it is also possible to preheat the adjusted spray liquid before spraying, continuously supply it from the nozzle, and dry the atomized liquid with warm air to form a powder. Heating increases the drying speed and enables highly non-volatile differentiation of the spray liquid as the viscosity of the spray liquid decreases, contributing to a reduction in production costs.

  In the present invention, the anti-caking agent is mixed with the synthetic resin emulsion (A), mixed with the re-emulsifiable resin powder (I) after spray drying, or the synthetic resin emulsion (A) during spray drying. It can be used together by spraying from another nozzle.

  By adding the anti-caking agent, it is possible to prevent the particles from being agglomerated, aggregated and blocked during storage, for example, when the resin powder is coated with the anti-caking agent.

  Examples of the anti-caking agent include known inert inorganic or organic powders. For example, calcium carbonate, talc, clay, dolomite, anhydrous silicic acid, alumina white and the like can be used as the inorganic powder. Among these, anhydrous silicic acid, calcium carbonate, clay and the like are preferable. As the organic powder, a resin powder obtained by spray-drying an emulsion having a glass transition temperature of 70 ° C. or higher of a synthetic resin can also be used as an anti-caking agent.

  It is preferable that the usage-amount of an anti-caking agent is about 5-30 weight part with respect to 100 weight part of re-emulsifiable resin powder (I) obtained. Moreover, combined use of organic powder and inorganic powder is also possible.

  The re-emulsifiable resin powder composition of the present invention comprises the re-emulsifiable resin powder (I) obtained as described above containing a condensed phosphate (II) and a crosslinking agent (III). is there. The condensed phosphate (II) and the crosslinking agent (III) will be described in order.

<< 2. Condensed phosphate (II) >>
In the present invention, the condensed phosphate (II) is added for the purpose of suppressing the drying of the inside of the coating film, and for improving the patterning property of the coating film surface, particularly in the summer, by preventing skinning (drying delay) and trowel etc. Is done.

  Here, the patterning property with a trowel or the like means the patterning property on the coating surface with a trowel or the like around 30 minutes after coating, particularly when the pattern is applied with a trowel or the like after coating in an architectural finish coating material for exterior use. I mean.

  As such condensed phosphate (II), for example, soda salts such as sodium hexametaphosphate, sodium pyrophosphate, and sodium acid phosphate can be used, but they are highly water-soluble and are widely used in paints and the like. In particular, sodium hexametaphosphate is particularly preferable.

  As content of condensed phosphate (II), 0.1-10 weight part is preferable with respect to 100 weight part of re-emulsifiable resin powder (I), 0.5-7 weight part is more preferable, 1 More preferred is ˜5 parts by weight. If the amount is too small, the effect of preventing skinning (drying delay) on the surface of the coating, especially in summer, tends to be reduced. If the amount is too large, the effect of preventing skinning (drying delay) is improved, but drying is delayed too much. The initial resistance to water resistance and hardness tends to be reduced.

  Next, the crosslinking agent (III) will be described.

<< 3. Crosslinking agent (III) >>
As the cross-linking agent (III), when it is stably mixed with the re-emulsifiable resin powder (I) and re-emulsified in water, the cross-linking proceeds rapidly, promoting the drying of the coating surface layer, and the desired coating. Since a film can be obtained, at least one powder, powder, granule or the like cross-linking agent selected from the group consisting of polyvalent metal salts, tertiary cationic resins, quaternary cationic resins and hydrazide compounds is used. It is preferable to contain. When the cross-linking agent is a liquid product, it can be used after being powdered.

<3-1. Multivalent metal salt>
Examples of the polyvalent metal salt include calcium, aluminum, magnesium, zirconium hydroxide or oxide, aluminum chloride and sulfate, zirconium nitrate, and the like. Among these, calcium is preferable, and calcium hydroxide is most preferable among them. This is because calcium hydroxide is hardly soluble and has a low solubility in water, so even if it is mixed in the re-emulsifiable resin powder composition, it does not hinder the re-emulsibility of the powder composition. Moreover, when an aqueous emulsion (re-emulsified liquid) obtained by re-emulsifying the re-emulsifiable resin powder composition containing calcium hydroxide is dried to form a film, it is water-soluble having a hydroxyl group such as a polyvinyl alcohol resin. This is because it is easy to form a complex with the resin and insolubilizes it, so that the water resistance can be improved.

<3-2.3 or quaternary cationic resin>
Examples of the tertiary or quaternary cationic resin include polydiallylamine and modified products thereof. Among these, a tertiary amine of polydiallylamine, a quaternary ammonium salt of polydiallylamine, and an acrylamide copolymer type thereof are more preferable. These tertiary or quaternary cationic resins have not only a function as a cross-linking agent but also a function as a dispersant when producing a building finish coating material or a powder coating material, and also have a water reducing effect. Accordingly, the non-volatile content of the architectural finish coating material and the powder paint is increased, and the drying property can be improved.

<3-3. Hydrazide compounds>
Examples of the hydrazide compound include adipic acid dihydrazide, polyhydrazide compound, carbohydrazide, and the like.

  These crosslinking agents (III) are not necessarily water-soluble, and may be easily dispersed in water at the time of use. These crosslinking agents (III) may be used alone or in combination of two or more thereof depending on the effect on the resulting coating film.

  When the re-emulsifiable resin powder (I) comprises at least one component of a polyvinyl alcohol-based resin containing at least one of a carbonyl group and an acetoacetyl group and an ethylenically unsaturated monomer as a constituent material. It is preferable to use a hydrazide compound as a crosslinking agent, and it may be used in combination with a polyvalent metal salt, a tertiary or quaternary cationic resin.

  Further, the re-emulsifiable resin powder (I) is obtained by copolymerizing one or more of unmodified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol and carbonyl group-modified polyvinyl alcohol, or a monomer containing acetoacetyl group or carbonyl group. In such a case, after re-emulsifying this to return to an emulsion state, depending on the use, an isocyanate compound, an aziridine compound, an epoxy group-containing compound, an amine compound, used as a crosslinking agent, It can also be used in appropriate combination with aldehyde compounds, methylol melamine polymers and the like. Thereby, it becomes possible to start up the physical properties of the coating film at an early stage. For example, in the case of producing wall materials in a factory, production efficiency can be improved.

  The content of the crosslinking agent (III) is preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the re-emulsifiable resin powder (I). The polyvalent metal salt and the tertiary or quaternary cation In the case of an ionic resin, 0.5 to 30 parts by weight is preferable, 3 to 15 parts by weight is more preferable, and 5 to 10 parts by weight is more preferable with respect to 100 parts by weight of the re-emulsifiable resin powder (I). If the amount is too small, there is a tendency that the effect of improving the coating properties such as initial water resistance and hardness of the coating film and early drying in the winter season cannot be fully expressed. In particular, in the case of a polyvalent metal salt, since the crosslinking proceeds too much, the coating film itself tends to be brittle. In the case of a tertiary or quaternary cationic resin, the water resistance tends to decrease.

  Further, the content in the case of the hydrazide compound may be appropriately selected depending on the amount of carbonyl group and acetoacetyl group in the resin that crosslinks with these, but with respect to 100 parts by weight of the re-emulsifiable resin powder (I), 0.1-10 weight part is preferable and 0.5-5 weight part is more preferable. If the amount is too small, the crosslinking effect tends not to be sufficiently exhibited, and if the amount is too large, no further effect tends to be expected.

  Furthermore, when the re-emulsifiable resin powder composition of the present invention or an aqueous emulsion re-emulsified in water is used as an adhesive for wood / wood adhesion, the crosslinking agent (III) is an isocyanate compound. Alternatively, the prepolymer, the epoxy compound or the prepolymer is preferably used.

  As mentioned above, the re-emulsifiable resin powder composition of this invention is obtained by mix | blending re-emulsifiable resin powder (I), condensed phosphate (II), and crosslinking agent (III).

<< Re-emulsifiable resin powder composition >>
The re-emulsifiable resin powder composition of the present invention thus obtained is excellent in water resistance and initial development of the hardness and hardness of the resulting coating film, and is coated while preventing skinning. Enables patterning on the painted surface with a trowel later. In particular, it is suitably used for building finish coating materials and powder coatings, and more preferably used for building finishing coating materials and powder coatings for exterior use. Also, various uses such as admixtures for hydraulic materials such as cement and plaster (for mortars for base preparations, tile adhesives, putty, etc.), wood or wood, and paper adhesives. Can be used.

  Moreover, according to the re-emulsifiable resin powder composition of the present invention, since the coating film is dried quickly, the next step can be entered without any problem even in the work in winter when the coating film is generally dried slowly. On the other hand, even in the summer when the coating film surface dries quickly, it is possible to prevent the coating film surface from being peeled and to easily pattern the coating surface with a trowel after coating. Such early drying properties and anti-skinning properties are particularly effective when used for exterior building finishes.

  The re-emulsifiable resin powder composition of the present invention can be blended with other additives as required. For example, when used for building finish coating materials / powder coatings, inorganic materials such as calcium carbonate, clay, talc, dolomite, mica, titanium oxide, and silica sand that are usually used for this type of application can be blended. . Hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, starch derivatives, inorganic thick powder thickeners / viscosity improvers, water repellents, powder antifoaming agents, crack generation preventive agents such as pulp powder, and the like can also be blended.

  In addition, when used as an architectural finish coating material / powder coating, if the re-emulsifiable resin powder of the present invention is blended with a hydraulic material such as cement or gypsum, the color tone may be affected. Since there is a risk that the balance between the initial development of water resistance and hardness of the material and the anti-skinning property that enables patterning on the coated surface with a trowel etc. after coating may be lost, hydraulic materials such as cement as much as possible It is preferable to contain the re-emulsifiable resin powder composition of the present invention in a building finish coating material / powder coating composition composed of a non-hydraulic material that does not use any of the above. However, hydraulic materials can also be used when it is not necessary to consider the color tone as the finished state, or even if it is a level that does not affect the color tone or the like.

  In addition, the re-emulsifiable resin powder composition of the present invention may be used after being re-emulsified in water and returned to an aqueous emulsion depending on the application and use conditions. This aqueous emulsion also has the same effects as the above-mentioned re-emulsifiable resin powder composition, for example, the initial development of water resistance and hardness of the coating film, durable adhesion of the coating film, and anti-skinning properties.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
In the examples, “parts” and “%” mean weight basis unless otherwise specified.

[Synthesis Example 1] (Production of synthetic resin emulsion (A-1))
In a 2L stainless steel reaction can equipped with a stirrer and a reflux condenser, 670 parts of water and acetoacetyl group-modified polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., saponification degree: about 98 mol%, 46 parts (average degree of polymerization: about 400, degree of acetoacetylation: 0.5 mol%) were charged, and the reaction vessel was heated to 85 ° C. to dissolve the acetoacetyl group-modified polyvinyl alcohol in water. Next, the temperature of the reaction vessel was kept at 80 ° C., and the mixed monomer (165 parts of butyl acrylate / 263 parts of styrene / 2230 parts of 2-ethylhexyl acrylate = 25/40/35) (hydrophobic) The initial polymerization reaction was carried out for 1 hour using 0.5 parts of ammonium persulfate as a polymerization initiator. Next, the remaining mixed monomer was dropped into the reaction vessel over 4 hours, and dropping polymerization was allowed to proceed while further adding 1.1 parts of ammonium persulfate as a polymerization initiator. After completion of the dropwise addition, the mixture was aged at the same temperature for 1 hour, and then a 20% aqueous solution 276 of partially saponified polyvinyl alcohol having an average polymerization degree of 600 and a saponification degree of 88 mol% (“GOHSENOL GL05” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) Part was added here and stirred well. As a result, a synthetic resin emulsion (A-1) (average particle size 0.45 μm) having a nonvolatile content of 46% was obtained. The value (W) calculated by the formula (4) of the obtained synthetic resin emulsion (A-1) was 78% by weight.

  The calculated glass transition temperature (Tg) of the synthetic resin composed of this main monomer (butyl acrylate / styrene / 2-ethylhexyl acrylate = 25/40/35) is the Tg of each homopolymer being −52 ° C., 100 ° C., When it is -70 degreeC, it is -18 degreeC.

[Synthesis Example 2] (Production of Synthetic Resin Emulsion (A-2))
Synthetic resin emulsion (synthetic resin emulsion) in the same manner as in Synthesis Example 1 except that the type and weight composition ratio of the mixed monomer were changed to butyl acrylate / styrene / diacetone acrylamide = 60/37/3 (hydrophobic monomer = 97%). A-2) (average particle size 0.43 μm) was produced. The value (W) calculated by the formula (4) of the obtained synthetic resin emulsion (A-2) was 82% by weight.

  The calculated glass transition temperature (Tg) of the synthetic resin composed of this main monomer (butyl acrylate / styrene / diacetone acrylamide = 60/37/3) is the Tg of each homopolymer at −52 ° C., 100 ° C., When it is 65 ° C., it is −3 ° C.

[Synthesis Example 3] (Production of synthetic resin emulsion (A-3))
The polyvinyl alcohol having a 1,2-diol bond in the side chain (average polymerization degree 300, saponification degree 99.1 mol%, side chain 1,2-diol bond The content was changed to 8 mol%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., and the type and weight composition ratio of the mixed monomer were changed to butyl acrylate / styrene = 46/54 (hydrophobic monomer = 100%). In the same manner as in Synthesis Example 1, an emulsion (A-3) (average particle size 0.47 μm) was produced. The value (W) calculated by the formula (4) of the obtained synthetic resin emulsion (A-3) was 69% by weight.

  The calculated glass transition temperature (Tg) of the synthetic resin composed of this main monomer (butyl acrylate / styrene = 46/54) is 10 ° C. when the Tg of each homopolymer is −52 ° C. and 100 ° C. .

However, for the purpose of adjusting the minimum film-forming temperature, 3 parts by weight of dibutyl phthalate as a plasticizer was added to 100 parts by weight of the nonvolatile content (resin content) of the synthetic resin emulsion (A) .

[Synthesis Example 4] (Production of Synthetic Resin Emulsion (A-4))
Emulsion (A-4) (average) in the same manner as in Synthesis Example 1 except that the type and weight composition ratio of the mixed monomer were changed to methyl methacrylate / 2-ethylhexyl acrylate = 50/50 (hydrophobic monomer = 50%). A particle diameter of 0.51 μm) was produced. The value (W) calculated by the formula (4) of the obtained synthetic resin emulsion (A-4) was 78% by weight.

  The calculated glass transition temperature (Tg) of the synthetic resin composed of the main monomer (methyl methacrylate / 2-ethylhexyl acrylate = 50/50) is as follows when the Tg of each homopolymer is 105 ° C. and −70 ° C. -9 ° C.

[Synthesis Example 5] (Production of synthetic resin emulsion (A-5))
Polyvinyl alcohol “GOHSENOL GL05” to be added after the completion of polymerization is added to polyvinyl alcohol having a 1,2-diol bond in the side chain (average polymerization degree 300, saponification degree 99.1 mol%, 1,2-diol bond in the side chain) Synthetic resin emulsion (A-5) (average particle size 0. 0), except that the content was changed to 276 parts of a 20% aqueous solution of 8 mol% of Nippon Synthetic Chemical Industry Co., Ltd.). 45 μm) was produced. The value (W) calculated by the formula (4) of the obtained synthetic resin emulsion (A-5) was 75% by weight.

[Synthesis Example 6] (Production of Synthetic Resin Emulsion (A ′))
Synthesis was performed in the same manner as in Synthesis Example 1 except that the type and weight composition ratio of the mixed monomer were changed to methyl methacrylate / 2-methoxyethyl acrylate / 2-ethylhexyl acrylate = 45/30/25 (hydrophobic monomer = 25%). Resin emulsion (A ′) (average particle size 0.45 μm) was produced. The value (W) calculated by the formula (4) of the obtained synthetic resin emulsion (A ′) was 50% by weight.

  The calculated glass transition temperature (Tg) of the synthetic resin composed of this main monomer (methyl methacrylate / 2-methoxyethyl acrylate / 2-ethylhexyl acrylate = 45/30/25) is the Tg of each homopolymer at 100 ° C. When it is set to −50 ° C. and −70 ° C., it is −8 ° C.

[Production Examples 1 to 6] (Production of re-emulsifiable resin powder (I))
The non-volatile components of the synthetic resin emulsions (A-1) to (A-5) and (A ′) obtained in Synthesis Examples 1 to 6 were adjusted, and the silica particles having an average particle size of about 0.02 μm were used as an anti-caking agent. In the presence of the powder (containing 15% by weight with respect to the re-emulsifiable resin powder (I)), the nozzle is spray-dried with hot air at 150 ° C. using a nozzle-type spray dryer, and the resin powder (I -1) to (I-5) and (I ') were obtained.

[Example 1]
To the resin powder (I-1) obtained in Production Example 1 above, sodium hexametaphosphate (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) as the condensed phosphate (II) and resin powder (I-1) 100 2 parts, 8 parts of the cross-linking agent (III) shown in Table 2 below, and a thickener, filler, antifoaming agent, etc. shown in Table 1 below were prepared in advance. An emulsifiable resin powder composition was obtained. This is dispersed in water to prepare an aqueous emulsion, and the viscosity is suitable for trowel coating (a slate plate coated with a trowel to a thickness of about 5 mm does not sag even if the slate plate is stood upright and left standing immediately. The building finish coating material was obtained.

[Examples 2 to 5]
In the same manner as in Example 1, architectural finishing coating materials (Examples 2 to 5) were obtained using the resin powders (I-2) to (I-5) obtained in Production Examples 2 to 6.

[Comparative Example 1]
In the same manner as in Example 1, an architectural finish coating material was obtained using the resin powder (I ′) obtained in Production Example 6.

[Comparative Example 2]
In Example 1, an architectural finish coating material was obtained in the same manner except that sodium hexametaphosphate (manufactured by Wako Pure Chemical Industries, Ltd.) was not blended.

  Using the architectural finish coating materials obtained in each of the above Examples and Comparative Examples, the following evaluation methods were used for the initial expression of water resistance and hardness of the coating film, durable adhesion of the coating film, and anti-skinning properties. Evaluation was performed. The results are shown in Table 2 below.

<Evaluation method>
(Water resistance and initial development of hardness of coating film)
The architectural finishing coating materials obtained in Examples 1 to 5 and Comparative Example 1 were applied to a slate plate with a 3 mm applicator and dried at room temperature. After drying for 4 hours, it was immersed in water for 2 hours and rubbed 10 times with a finger strongly, and the finished state of the coated surface was evaluated according to the following criteria. In this test, it was set as a substitute test of the initial expression of water resistance and hardness of the coating film, and the evaluation A-B was accepted as a practically acceptable level.

A: The surface of the coating film is hard, the coating film is hardly removed even by rubbing with a finger, and the white color of the emulsion does not flow out.
B: Although the surface of the coating film is hard, the surface is slightly removed when rubbed with a finger, and the white color of the emulsion flows out slightly.
C: The surface of the coating film is slightly soft, the surface is removed when rubbed with a finger, and the white color of the emulsion flows out.
D: The coating film absorbs water and is in a brilliant state. When rubbed with a finger, the entire surface is removed from the base and the white color of the emulsion flows out.

(Durable film adhesion)
The architectural finishing coating materials obtained in Examples 1 to 5 and Comparative Example 1 were applied to a slate plate with a 3 mm applicator and dried at room temperature. After drying for 24 hours, it was immersed in water for 6 hours and rubbed 10 times with a dishwashing sponge, and the finished state of the coated surface was evaluated according to the following criteria. Furthermore, the coating film was shaved with a spatula, and the peeling method of the coating film, the adhesion of the coating film to the ground, and the like were visually evaluated according to the following criteria. In this test, it was set as the substitute test of the durable adhesiveness of a coating film, and evaluation AB was set as the level which is practically satisfactory, and was set as the pass.

A: The coating film surface is hard, and the coating film cannot be removed by rubbing with a sponge. Very strong force is needed to scrape off the coating film with a spatula and it adheres well to the substrate.
B: The coating film surface is hard, and the coating film can hardly be removed by rubbing with a sponge, but a little force is required to scrape the coating film with a spatula.
C: The coating film surface is hard, and the coating film can hardly be removed by rubbing with a sponge. However, since the coating film is brittle, it does not require much force to be scraped off with a spatula.
D: The coating film surface is soft, and the coating film can be almost removed by rubbing with a sponge.

(Skin prevention)
The architectural finishing coating material obtained in Examples 1 to 5 and Comparative Example 1 was applied to a slate plate with a trowel so that the wet thickness was 3 mm, and the coated surface was coated after 1 hour and 2 hours after drying at room temperature. The following criteria evaluated whether the patterning property by a state and a soldering iron was possible. In this test, it was regarded as a substitute test for prevention of skinning after coating, and the evaluation A-B was accepted as a practically acceptable level.
A: There is no skin on the coating surface, and patterning with a trowel is as easy as coating.
B: Slight skinning is observed on the coated surface, but patterning with a trowel is easy.
C: Skinning is observed on the painted surface, but patterning with a trowel is possible.
D: Skinning is recognized on the painted surface, and it is difficult to pattern with a trowel.

  From the above results, in all examples, the evaluation is A or B and is a pass level, the initial expression of water resistance and hardness of the obtained coating film, durable adhesion of the coating film, and prevention of skinning It met all the characteristics of sex.

  On the other hand, in Comparative Example 1 in which the content of the hydrophobic monomer is less than the content specified by the present invention, the coating film has no water resistance and hardness in a buoyant state, and is simply The coating film peeled off and could not be used as an architectural finish coating material. Moreover, the comparative example 2 which did not add a crosslinking agent was inferior in skin-preventing property, and could not be patterned.

  In addition, the calcium hydroxide as the cross-linking agent is added to the tertiary amine of polydiallylamine as a tertiary cationic resin, the quaternary ammonium salt of polydiallylamine as a quaternary cationic resin, and adipic acid dihydrazide as a hydrazide compound. Even if it replaced, the effect similar to an Example was seen.

  The re-emulsifiable resin powder composition of the present invention is excellent in the initial development of water resistance and hardness of the obtained coating film, in addition to the durable adhesion of the coating film, and prevents the state of skinning of the coating film, It has an excellent effect of easily enabling patterning on the coated surface with a trowel after coating. In particular, it is preferably used for architectural finishing coating materials and powder coatings. However, if it is mixed with a hydraulic material such as cement or gypsum, it may affect the color tone. It is preferable to make it contain in the formulation for use. On the other hand, it is also useful for various applications such as admixtures for hydraulic materials such as cement and gypsum, and adhesives for wood, wood, paper and the like. In particular, since the present invention is a re-emulsifiable resin powder composition, a desired product can be produced simply by kneading with water at the time of use as a completely ready-made product.

Claims (14)

A re-emulsifiable resin powder composition containing re-emulsifiable resin powder (I), condensed phosphate (II), and crosslinking agent (III), and said re-emulsifiable resin powder (I) is A synthetic resin obtained by polymerizing an ethylenically unsaturated monomer component containing 30% by weight or more of a hydrophobic monomer having a solubility in water at 20 ° C. of 0.3% by weight or less is dispersed with a polyvinyl alcohol resin (a). A re-emulsifiable resin powder composition, which is a dried product of an emulsion obtained by further adding a re-emulsibility improver (B) to the stabilized emulsion (A). The ethylenically unsaturated monomer component is an allyl group-containing ethylenically unsaturated monomer, glycidyl group-containing ethylenically unsaturated monomer, hydrolyzable silyl group-containing ethylenically unsaturated monomer, acetoacetyl group-containing ethylenically unsaturated monomer, vinyl re-emulsifiable in claim 1 Symbol mounting, characterized in that one or more kinds of functional ethylenically unsaturated monomer selected from the group consisting of group-containing ethylenically unsaturated monomer and carbonyl group-containing ethylenically unsaturated monomer Resin powder composition. The re-emulsifiable resin powder composition according to claim 1 or 2, wherein the condensed phosphate (II) is sodium hexametaphosphate. The content of the condensed phosphate (II) is, relative to 100 parts by weight of re-emulsifiable resin powder (I), according to any one of claims 1-3, characterized in that from 0.1 to 10 parts by weight Re-emulsifiable resin powder composition. Crosslinking agent (III) is a polyvalent metal salt, a tertiary cation resin, any claims 1-4, characterized in that at least one selected from the group consisting of quaternary cationic resin and hydrazide compounds The re-emulsifiable resin powder composition described. The content of the crosslinking agent (III) is, relative to 100 parts by weight of re-emulsifiable resin powder (I), according to claim 1 to 5, wherein any one, which is a 0.1 to 30 parts by weight Re Emulsifiable resin powder composition. The re-emulsifiable resin powder composition according to any one of claims 1 to 6 , wherein the polyvinyl alcohol resin (a) is a polyvinyl alcohol resin (a1) containing active hydrogen. The re-emulsifiable resin powder composition according to claim 7, wherein the polyvinyl alcohol resin (a1) containing active hydrogen is an acetoacetyl group-modified polyvinyl alcohol resin. The re-emulsifiable resin powder composition according to any one of claims 1 to 6, wherein the polyvinyl alcohol resin (a) is a polyvinyl alcohol resin (a2) having a 1,2-diol bond in a side chain. object. The re-emulsifiable resin powder composition according to any one of claims 1 to 9, wherein the re-emulsification improver (B) is a polyvinyl alcohol resin (b). The polyvinyl alcohol resin (b) is an acetoacetyl group-modified polyvinyl alcohol resin (b1), a polyvinyl alcohol resin (b2) having a 1,2-diol bond in the side chain, and a carbonyl group-modified polyvinyl alcohol resin (b3). The re-emulsifiable resin powder composition according to claim 10, which is at least one selected from the group consisting of: An aqueous emulsion obtained by re-emulsifying the re-emulsifiable resin powder composition according to any one of claims 1 to 11 . Claim 1-11 re-emulsifiable resin powder composition or comprising an aqueous emulsion of claim 12, wherein building finish materials according any. The architectural finish coating material or powder coating composition comprising a non-hydraulic material contains the re-emulsifiable resin powder composition according to any one of claims 1 to 11 or the aqueous emulsion according to claim 12. Architectural finishing coating material.