JP5143777B2 - Synthetic resin emulsion powder and method for producing the same - Google Patents

Description

  The present invention relates to a synthetic resin emulsion powder and a method for producing the same, and more specifically, vinyl alcohol polymer as a dispersant, and one or more selected from ethylenically unsaturated monomers and diene monomers. The emulsion (A) having a polymer having an unsaturated monomer unit as a dispersoid is a vinyl alcohol polymer containing a polyoxyalkylene group represented by the following general formula (I) in the side chain, The polyoxyalkylene polymer has a viscosity average polymerization degree of 100 to 3000, a saponification degree of 70.0 to 99.5 mol% or more, and a polyoxyalkylene modification amount of 0.1 to 10 mol%. The present invention relates to a synthetic resin powder obtained by drying a composition containing an alkylene-vinyl alcohol polymer (B) and a method for producing the same.

The synthetic resin emulsion powder is produced by spray-drying the synthetic resin emulsion, and is superior in terms of handling and transportation because it is a powder compared to the synthetic resin emulsion. Further, in use, it is easily redispersed in water by adding water and stirring, and therefore, it is used in a wide range of applications such as an admixture to cement or mortar, an adhesive, and a binder for paint. Among them, the admixture for mortar is widely used because it is a powder and can be premixed and can be used in various commercial forms. However, in the conventional synthetic resin emulsion, when it is spray-dried as it is, the dispersoid easily melts and does not re-disperse in water, so a large amount of polyvinyl alcohol (hereinafter may be abbreviated as PVA). At present, it is necessary to add a large amount of inorganic powder such as silicic acid anhydride as an antiblocking agent after the addition. As the PVA to be added later, low polymerization degree PVA has heretofore been widely used because it is necessary to re-emulsify after use after powdering. (Patent Document 1)
However, in these synthetic resin emulsion powders, the post-added PVA is a low polymerization degree PVA. Therefore, even when redispersed in water, the dispersion has a lower viscosity than the synthetic resin emulsion of the same solid content, such as cement mortar. In order to increase the viscosity even when used as an admixture for hydraulic materials, a thickener must be used. In addition, in order to increase the viscosity of the dispersion after redispersion, if the degree of polymerization of the post-added PVA is increased, the redispersibility decreases and the dispersibility in hydraulic substances also decreases, so the water reduction decreases. However, there is a problem that the strength of the obtained hydraulic substance cannot be sufficiently obtained.
Patent-36818540

  The object of the present invention is to solve the above-mentioned problems, to obtain a synthetic resin emulsion powder having excellent redispersibility and higher viscosity, and to reduce water when mixed with a hydraulic substance such as cement mortar. It is an object to provide a synthetic resin emulsion powder capable of achieving both high viscosity and high viscosity.

  As a result of intensive investigations in view of the above circumstances, the present inventors have found that one or two or more kinds of solvents selected from ethylenically unsaturated monomers and diene monomers using a vinyl alcohol polymer as a dispersant. The emulsion (A) having a polymer having a saturated monomer unit as a dispersoid contains a polyoxyalkylene group represented by the general formula (I) (hereinafter sometimes abbreviated as POA group) in the side chain. It is a vinyl alcohol polymer, the viscosity average polymerization degree of the vinyl alcohol polymer is 100 to 3000, the saponification degree is 70.0 to 99.5 mol%, and the polyoxyalkylene modification amount is 0.1 to A synthetic resin emulsion powder obtained by drying a composition containing 10 mol% of a polyoxyalkylene-vinyl alcohol polymer (B) solves the above problems. Out, it has led to the completion of the present invention.

According to the present invention, a synthetic resin emulsion powder having excellent redispersibility and higher viscosity can be obtained.
By using the synthetic resin emulsion powder of the present invention, it is excellent in dispersibility in hydraulic substances such as cement mortar, and when mixed with hydraulic substances such as cement mortar, both water reduction and viscosity increase can be obtained. Viscosity and water retention of hydraulic substances are increased, troweling and spreading are improved, mortar setting time and watering time are delayed, so workability is remarkably improved and cracking is also suppressed. Is obtained. Further, by using the synthetic resin emulsion powder of the present invention, a joining material for a hydraulic substance that is excellent in adhesiveness and durability and further excellent in mechanical strength can be obtained.

Hereinafter, the synthetic resin emulsion powder of the present invention will be described in detail.
In the present invention, the dispersoid of the emulsion (A) is composed of a polymer having one or more unsaturated monomer units selected from ethylenically unsaturated monomers and diene monomers. Examples of the ethylenically unsaturated monomer include olefins such as ethylene, propylene, and isobutene, halogenated olefins such as vinyl chloride, vinylidene chloride, vinyl fluoride, and vinylidene fluoride, vinyl formate, vinyl acetate, vinyl propionate, Vinyl esters such as vinyl versatate and vinyl pivalate, acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, acrylic acid Acrylic acid esters such as t-butyl, 2-ethylhexyl acrylate, dodecyl acrylate, octadecyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n methacrylate -Butyl, meta Methacrylic acid esters such as i-butyl acrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate and octadecyl methacrylate, nitriles such as acrylonitrile and methacrylonitrile, allyl such as allyl acetate and allyl chloride Compound, Styrene monomers such as styrene, α-methylstyrene, p-methylstyrenesulfonic acid and sodium and potassium salts thereof, trimethyl- (3-acrylamido-3-dimethylpropyl) -ammonium chloride, 3-acrylamidopropyl Trimethylammonium chloride, 3-methacrylamidopropyltrimethylammonium chloride, quaternary ammonium salt of N- (3-allyloxy-2-hydroxypropyl) dimethylamine, N- (4-allyloxy- 3-hydroxybutyl) diethylamine quaternary ammonium salt, acrylamide, N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, diacetone acrylamide, N-methylolacrylamide, methacrylamide, N-methylmethacrylamide Quaternary ammonium salts such as N-ethylmethacrylamide and N-methylolmethacrylamide, hydroxypropyltrimethylammonium methacrylate methacrylate, hydroxypropyltrimethylammonium chloride acrylate, N-vinylpyrrolidone and the like, and diene monomers Examples thereof include butadiene, isoprene, chloroprene and the like. These monomers are used alone or in combination of two or more.
Among the polymers composed of the above monomer units, vinyl ester polymers typified by vinyl acetate polymers, olefin-vinyl ester copolymers typified by ethylene-vinyl acetate copolymers, etc. This is one of the preferred embodiments of the invention.

  In the present invention, a vinyl alcohol polymer is used as the dispersant for the emulsion (A). The vinyl alcohol polymer is produced, for example, by saponifying a vinyl ester polymer obtained by polymerizing a vinyl ester. The saponification degree of the vinyl alcohol polymer is not particularly limited, but is preferably 70 to 99 mol%, more preferably 80 to 98 mol%, and still more preferably 83 to 95 mol%. When the degree of saponification is less than 70 mol%, there is a concern that water solubility, which is the original property of the vinyl alcohol polymer, is lowered. Further, when the degree of saponification exceeds 99 mol%, there is a concern that emulsion polymerization becomes unstable. The viscosity average polymerization degree (hereinafter abbreviated as polymerization degree) of the vinyl alcohol polymer is not particularly limited, but is preferably in the range of 100 to 3000, more preferably 300 to 3000, and even more preferably 300 to 2500. Moreover, as a vinyl alcohol polymer of the dispersing agent of emulsion (A), a vinyl alcohol polymer having a 1,2-glycol bond of 1.9 mol% or more is preferably used. As a method for producing a polymer having a 1,2-glycol bond of 1.9 mol% or more, for example, a method of copolymerizing vinylene carbonate with a vinyl ester monomer so as to have the above 1,2-glycol bond amount, Alternatively, when polymerizing a vinyl ester monomer, a method of polymerizing under pressure at a temperature higher than normal conditions, for example, 75 to 200 ° C., may be mentioned. In the latter method, the polymerization temperature is not particularly limited, but is usually 95 to 190 ° C, preferably 100 to 180 ° C.

  The vinyl alcohol polymer may be a copolymer of an ethylenically unsaturated monomer that can be copolymerized within a range that does not impair the effects of the present invention. Examples of such ethylenically unsaturated monomers include acrylic acid, methacrylic acid, fumaric acid, (anhydrous) maleic acid, itaconic acid, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, trimethyl- (3-acrylamide). -3-dimethylpropyl) -ammonium chloride, acrylamido-2-methylpropanesulfonic acid and its sodium salt, ethyl vinyl ether, butyl vinyl ether, vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride, vinylidene fluoride, tetrafluoroethylene N-vinylamides such as sodium vinylsulfonate, sodium allylsulfonate, N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, and the like. Also, vinyl ester monomers such as vinyl acetate and the above ethylenically unsaturated monomers are copolymerized in the presence of thiol compounds such as thiol acetic acid and mercaptopropionic acid, and the resulting copolymer is saponified. It is also possible to use a terminally modified product obtained by doing so.

  The synthetic resin emulsion (A) used in the present invention is one or more monomers selected from ethylenically unsaturated monomers and diene monomers in the presence of the above-mentioned vinyl alcohol polymer. The synthetic resin emulsion powder is obtained by drying, particularly spray drying, the synthetic resin emulsion. In the production of the synthetic resin emulsion, as an initiator for emulsion polymerization, a polymerization initiator usually used for emulsion polymerization, that is, a water-soluble initiator such as potassium persulfate, ammonium persulfate, hydrogen peroxide, t-butyl hydroperoxide, etc. In addition, oil-soluble initiators such as azobisisobutyronitrile and benzoyl peroxide are used in redox systems alone or in combination with various reducing agents. Although there are no particular limitations on the method of using these, a method of adding in an initial batch, a method of adding continuously to a polymerization system, or the like can be employed.

In the synthetic resin emulsion (A) used in the present invention, the amount of the vinyl alcohol polymer used is not particularly limited, but is usually 2 to 30 parts by weight, preferably 3 to 15 parts by weight, based on 100 parts by weight of the monomer. More preferably, it is 3-10 weight part. When the vinyl alcohol polymer is less than 2 parts by weight, the polymerization stability of the synthetic resin emulsion is lowered, and the mechanical stability and chemical stability which are the characteristics of the synthetic resin emulsion using the vinyl alcohol polymer as a dispersant are characteristic. There is a concern that a decrease in film strength and a decrease in film strength may occur. On the other hand, when the amount of the vinyl alcohol polymer exceeds 30 parts by weight, there are concerns such as a problem of removal of reaction heat due to an increase in the viscosity of the polymerization system and a decrease in water resistance of the film.
There is no particular limitation on the method of adding the vinyl alcohol polymer, a method of adding all at once in the initial stage, a method of adding a part of the vinyl alcohol polymer in the initial stage, and continuously adding to the polymerization system during the polymerization, etc. There is.
In addition, a conventionally known nonionic, anionic, cationic or amphoteric surfactant or a water-soluble polymer such as hydroxyethyl cellulose may be used in combination with the vinyl alcohol polymer.

  As a method for adding a monomer when producing the synthetic resin emulsion (A) used in the present invention, a method of adding to the polymerization system all at once, adding a part of the monomer at the initial stage, and polymerizing the rest Various methods are possible, such as a method of continuously adding the monomer, water and a dispersant previously emulsified, and a method of continuously adding to the polymerization system.

Moreover, a chain transfer agent can also be added when manufacturing the synthetic resin emulsion (A) used for this invention. The chain transfer agent is not particularly limited as long as chain transfer occurs, but a compound having a mercapto group is preferable from the viewpoint of chain transfer efficiency. Examples of the compound having a mercapto group include alkyl mercaptans such as n-octyl mercaptan, n-dodecyl mercaptan and t-dodecyl mercaptan, 2-mercaptoethanol, and 3-mercaptopropionic acid.
The addition amount of the chain transfer agent is preferably 5 parts by weight or less with respect to 100 parts by weight of the monomer. When the addition amount of the chain transfer agent exceeds 5 parts by weight, the polymerization stability of the synthetic resin emulsion is lowered, and the molecular weight of the polymer forming the dispersoid is remarkably lowered, and there is a concern that the physical properties of the emulsion may be lowered. is there.

  The polyoxyalkylene-vinyl alcohol polymer (B) blended in the emulsion (A) is a vinyl alcohol heavy polymer containing a polyoxyalkylene group (POA group) represented by the general formula (I) in the side chain. It is a coalescence.

式中、Ｒ１は水素原子またはメチル基、Ｒ２は水素原子または炭素数１〜８のアルキル基を表す。ｍとｎはそれぞれの（ポリ）オキシレンユニットの繰り返し単位を表し、０≦ｍ≦１０、３≦ｎ≦２０である。ここで、繰り返し単位ｍで表されるユニットをユニット１と呼び、繰り返し単位ｎで表されるユニットをユニット２と呼ぶことにする。ユニット１とユニット２の配置は、ランダム状、ブロック状のどちらの形態になっても良い。

In the formula, R1 represents a hydrogen atom or a methyl group, and R2 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. m and n represent a repeating unit of each (poly) oxylene unit, and 0 ≦ m ≦ 10 and 3 ≦ n ≦ 20. Here, the unit represented by the repeating unit m will be referred to as unit 1, and the unit represented by the repeating unit n will be referred to as unit 2. The arrangement of the unit 1 and the unit 2 may be random or block.

  The degree of polymerization of the polyoxyalkylene-vinyl alcohol polymer (B) (hereinafter sometimes abbreviated as POA-modified PVA) needs to be 100 to 3000 from the viewpoint of workability during powderization, and Preferably it is 150-2000, More preferably, it is 200-1600, Optimally, it is 200-1000. On the other hand, the saponification degree of the polyoxyalkylene-vinyl alcohol polymer (B) is required to be 70.0 to 99.5 mol% from the viewpoint of redispersibility and workability during powdering, 75.0-98.0 mol% is more preferable, and 80.0-96.0 mol% is further more preferable.

  Examples of the unsaturated monomer having a POA group represented by the general formula (I) include an unsaturated monomer represented by the general formula (II).

式中、Ｒ１は水素原子またはメチル基を表す。Ｒ２は水素原子または炭素数１〜８のアルキル基を表す。Ｒ３は水素原子または−ＣＯＯＭ基を表し、ここでＭは水素原子、アルカリ金属またはアンモニウム基を意味する。Ｒ４は水素原子、メチル基または−ＣＨ_２−ＣＯＯＭ基を表し、ここでＭは前記定義のとおりである。Ｘは−Ｏ−、−ＣＨ_２−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−または−ＣＯ−ＮＲ５を表し、ここでＲ５は水素原子または炭素数１〜４の飽和アルキル基を意味する。ｍとｎはそれぞれの（ポリ）オキシレンユニットの繰り返し単位を表し、０≦ｍ≦１０、３≦ｎ≦２０である。

In the formula, R1 represents a hydrogen atom or a methyl group. R2 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R3 represents a hydrogen atom or a -COOM group, where M represents a hydrogen atom, an alkali metal or an ammonium group. R4 represents a hydrogen atom, a methyl group or a —CH ₂ —COOM group, where M is as defined above. X represents —O—, —CH ₂ —O—, —CO—, —CO—O— or —CO—NR 5, wherein R 5 represents a hydrogen atom or a saturated alkyl group having 1 to 4 carbon atoms. m and n represent a repeating unit of each (poly) oxylene unit, and 0 ≦ m ≦ 10 and 3 ≦ n ≦ 20.

R2 of the unsaturated monomer represented by the general formula (II) is preferably a hydrogen atom, a methyl group or a butyl group, more preferably a hydrogen atom or a methyl group. Furthermore, it is particularly preferable that R1 of the unsaturated monomer represented by the general formula (II) is a hydrogen atom, R2 is a hydrogen atom or a methyl group, and R3 is a hydrogen atom.
For example, when R1 in the general formula (II) is a hydrogen atom, R2 is a hydrogen atom, and R3 is a hydrogen atom, the unsaturated monomer represented by the general formula (II) is specifically polyoxyethylene polyoxybutylene. Monoacrylate, polyoxyethylene polyoxybutylene monomethacrylate, polyoxyethylene polyoxybutylene monoacrylic amide, polyoxyethylene polyoxybutylene monomethacrylamide, polyoxyethylene polyoxybutylene monoallyl ether, polyoxyethylene polyoxybutylene Monomethallyl ether, polyoxyethylene polyoxybutylene monovinyl ether, polyoxyethylene polyoxybutylene monoacrylate, polyoxyethylene polyoxybutylene monomethacrylate, polyoxyethylene polyoxybutyl Examples include tylene monoacrylic amide, polyoxyethylene polyoxybutylene monomethacrylamide, polyoxyethylene polyoxybutylene monoallyl ether, polyoxyethylene polyoxybutylene monomethallyl ether, polyoxyethylene polyoxybutylene monovinyl ether, and the like. . Among them, polyoxyethylene polyoxybutylene monoacrylic acid amide, polyoxyethylene polyoxybutylene monomethacrylic acid amide, polyoxyethylene polyoxybutylene monovinyl ether are preferably used, polyoxyethylene polyoxybutylene monomethacrylic acid amide, Polyoxyethylene polyoxybutylene monovinyl ether is particularly preferably used.

  When R2 in the general formula (II) is an alkyl group having 1 to 8 carbon atoms, specifically, as the unsaturated monomer represented by the general formula (II), R2 in the general formula (II) is a hydrogen atom. In the case of the above, there may be mentioned those obtained by substituting the terminal OH group of the unsaturated monomer with an alkoxy group having 1 to 8 carbon atoms. Of these, unsaturated monomers in which the OH group at the terminal of polyoxyethylene polyoxybutylene monomethacrylamide or polyoxyethylene polyoxybutylene monovinyl ether is substituted with a methoxy group are preferably used. An unsaturated monomer in which the OH group at the terminal of butylene monomethacrylamide is substituted with a methoxy group is particularly preferably used.

  The modified amount of POA needs to be 0.1 to 10 mol%. The POA modification amount is preferably 0.2 mol% or more, more preferably 0.3 mol% or more. When the POA modification amount exceeds 10 mol%, the redispersibility of the blended synthetic resin emulsion powder is extremely poor and the film forming property is also poor. On the other hand, when the POA modification amount is less than 0.1 mol%, the redispersibility of the blended synthetic resin emulsion powder is excellent, but physical properties based on POA modification may not be exhibited.

The POA modification amount is represented by the molar fraction of the POA group with respect to the main chain methylene group of PVA, and can be determined from the proton NMR of the POA-modified polyvinyl acetate (PVAc) which is the precursor of the PVA. Specifically, after re-precipitation purification of POA-modified PVAc with n-hexane / acetone three times or more sufficiently, drying is performed under reduced pressure at 50 ° C. for 2 days to prepare POA-modified PVAc for analysis. The PVAc is dissolved in CDCl ₃ and measured at room temperature using 500 MHz proton NMR (JEOL GX-500). POA modification amount from peak α (4.7 to 5.2 ppm) derived from main chain methine of vinyl ester and peak β (0.8 to 1.0 ppm) derived from terminal methyl group of unit 2 using the following formula S is calculated.
S (mol%) = {(number of protons of β / 3n) / (number of protons of α + (number of protons of β / 3n))} × 100
n represents the number of repeating units of unit 2.

  The number m of repeating units of the POA group unit 1 represented by the general formula (I) needs to satisfy 0 ≦ m ≦ 10, more preferably 1 ≦ m ≦ 5, and particularly preferably 1 ≦ m ≦ 2. Further, the number n of repeating units of unit 2 needs to satisfy 3 ≦ n ≦ 20, preferably 5 ≦ n ≦ 18, and particularly preferably 8 ≦ n ≦ 15. When n is less than 3, the interaction between POA groups does not develop, the viscosity of the re-dispersed liquid of the synthetic resin emulsion powder may be low, and when n exceeds 20, the hydrophobicity of the POA group becomes high, The redispersibility of the synthetic resin emulsion powder may be reduced.

The content of the monomer having a POA group represented by formula (I) is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and particularly preferably 15 parts by weight or less. When the content of the POA group exceeds 50 parts by weight, the hydrophobicity of the PVA increases and the water solubility may decrease. The lower limit of the content is preferably 2.5 parts by weight or more.
Here, the content of the monomer unit having a POA group is represented by the weight part (weight fraction) of the POA group with respect to 100 parts by weight of the PVA main chain. Even if the above-mentioned POA modification amount S is equivalent, the content of the monomer unit increases as the degree of saponification increases or as the repeating unit n of the unit 2 increases.

  In order to produce POA-modified PVA, copolymerization of an unsaturated monomer having a POA group and a vinyl ester monomer is carried out in an alcohol solvent or without solvent, and the resulting POA-vinyl ester copolymer is obtained. A method of saponifying the coalescence is preferred. The temperature employed when copolymerizing the unsaturated monomer having a POA group and the vinyl ester monomer is preferably 0 to 200 ° C, more preferably 30 to 140 ° C. When the copolymerization temperature is lower than 0 ° C., it is difficult to obtain a sufficient polymerization rate. Moreover, when the temperature which superposes | polymerizes is higher than 200 degreeC, it is difficult to obtain POA modified PVA which has the POA modified amount prescribed | regulated by this invention. As a method for controlling the temperature employed in the copolymerization to 0 to 200 ° C., for example, by controlling the polymerization rate, the heat generated by the polymerization is balanced with the heat released from the surface of the reactor. Examples thereof include a method and a method of controlling by an external jacket using an appropriate heating medium, but the latter method is preferable from the viewpoint of safety.

  The polymerization method used for copolymerizing the unsaturated monomer having a POA group and the vinyl ester monomer may be any of batch polymerization, semi-batch polymerization, continuous polymerization, and semi-continuous polymerization. As the polymerization method, any known method such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method, or an emulsion polymerization method can be used. Among them, a bulk polymerization method or a solution polymerization method in which polymerization is performed without a solvent or an alcohol solvent is suitably employed, and an emulsion polymerization method is employed for the purpose of producing a copolymer having a high degree of polymerization. As the alcohol solvent, methyl alcohol, ethyl alcohol, propyl alcohol, and the like can be used, but are not limited thereto. These solvents can be used in combination of two or more. As the initiator used for copolymerization, conventionally known azo initiators, peroxide initiators, redox initiators and the like are appropriately selected according to the polymerization method. As the azo initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4- Dimethyl valeronitrile) and the like. Peroxide compounds such as diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, diethoxyethyl peroxydicarbonate; t-butyl Perester compounds such as peroxyneodecanate, α-cumylperoxyneodecanate, t-butylperoxydecanate; acetylcyclohexylsulfonyl peroxide; 2,4,4-trimethylpentyl-2-peroxyphenoxyacetate, etc. Is mentioned. Furthermore, the initiator can be combined with potassium persulfate, ammonium persulfate, hydrogen peroxide, or the like to form an initiator. Examples of the redox initiator include a combination of the above-described peroxide and a reducing agent such as sodium hydrogen sulfite, sodium hydrogen carbonate, tartaric acid, L-ascorbic acid, or longalite. In addition, when copolymerization of POA and a vinyl ester monomer is performed at a high temperature, coloring of PVA or the like due to decomposition of the vinyl ester monomer may be observed. For the purpose of prevention, there may be no problem adding an antioxidant such as tartaric acid to the polymerization system in an amount of 1 to 100 ppm (based on the vinyl ester monomer).

  Examples of vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, Examples include vinyl stearate, vinyl oleate, and vinyl benzoate. Among them, vinyl acetate is most preferable.

  When the unsaturated monomer having a POA group and the vinyl ester monomer are copolymerized, other monomers may be copolymerized as long as the gist of the present invention is not impaired. Examples of monomers that can be used include α-olefins such as ethylene, propylene, n-butene, and isobutylene; acrylic acid and salts thereof; methyl acrylate, ethyl acrylate, n-propyl acrylate, and i-propyl acrylate. Acrylates such as n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, octadecyl acrylate; methacrylic acid and salts thereof; methyl methacrylate, methacryl Methacrylic acid such as ethyl acetate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate Beauty treatment Acrylamide; N-methyl acrylamide, N-ethyl acrylamide, N, N-dimethyl acrylamide, diacetone acrylamide, acrylamide propane sulfonic acid and its salt, acrylamidopropyldimethylamine and its salt or quaternary salt thereof, N-methylol acrylamide Acrylamide derivatives such as and derivatives thereof; methacrylamide; N-methyl methacrylamide, N-ethyl methacrylamide, methacrylamide propane sulfonic acid and salts thereof, methacrylamide propyldimethylamine and salts thereof or quaternary salts thereof, N-methylol methacryl Methacrylamide derivatives such as amides and derivatives thereof; methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl Vinyl ethers such as nyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether; nitriles such as acrylonitrile and methacrylonitrile; vinyl halides such as vinyl chloride and vinyl fluoride; Vinylidene halides such as vinylidene chloride and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; unsaturated dicarboxylic acids such as maleic acid, itaconic acid and fumaric acid, and salts or esters thereof; vinyltrimethoxysilane, etc. Vinylsilyl compounds; isopropenyl acetate and the like.

  Further, in the copolymerization of an unsaturated monomer having a POA group and a vinyl ester monomer, for the purpose of adjusting the degree of polymerization of the obtained copolymer, the scope of the present invention is not impaired. Copolymerization may be carried out in the presence of a chain transfer agent. Examples of chain transfer agents include aldehydes such as acetaldehyde and propionaldehyde; ketones such as acetone and methyl ethyl ketone; mercaptans such as 2-hydroxyethanethiol; and halogenated hydrocarbons such as trichloroethylene and perchloroethylene. Of these, aldehydes and ketones are preferably used. The addition amount of the chain transfer agent is determined according to the chain transfer constant of the chain transfer agent to be added and the degree of polymerization of the target vinyl ester polymer, but is generally 0.1% relative to the vinyl ester monomer. -10 wt% is desirable.

  The saponification reaction of the POA-vinyl ester copolymer is an alcoholysis decomposition reaction using a conventionally known basic catalyst such as sodium hydroxide, potassium hydroxide or sodium methoxide or an acidic catalyst such as P-toluenesulfonic acid. Alternatively, a hydrolysis reaction can be applied. Examples of the solvent that can be used for this reaction include alcohols such as methanol and ethanol; esters such as methyl acetate and ethyl acetate; ketones such as acetone and methyl ethyl ketone; aromatic hydrocarbons such as benzene and toluene; These can be used alone or in combination of two or more. Among them, it is convenient and preferable to perform the saponification reaction using methanol or a methanol / methyl acetate mixed solution as a solvent and sodium hydroxide as a catalyst.

  The blending ratio of the POA-modified PVA (B) blended in the emulsion (A) is 1 to 50 parts by weight of the POA-modified PVA (B) with respect to 100 parts by weight of the solid content (dispersoid) of the emulsion (A). It is suitable, More preferably, it is 3-30 weight part, More preferably, it is 5-20 weight part, Furthermore, it is 7-20 weight part. When the POA-modified PVA (B) is less than 1 part by weight, there is a concern that the redispersibility after pulverization is lowered, and the mechanical stability when the emulsion powder is mixed with a hydraulic substance is insufficient. There is a concern that the dispersibility of the substance may decrease. On the other hand, when the amount exceeds 50 parts by weight, there is a concern that physical properties such as water resistance of the obtained emulsion powder are lowered and the strength of the hydraulic substance using the emulsion powder is lowered.

The synthetic resin emulsion powder of the present invention is obtained by blending the above emulsion (A) with POA-modified PVA (B) and then drying, preferably spray drying. For spray drying, normal spray drying in which a fluid is sprayed to dry can be used. Depending on the type of spraying, there are disc type, nozzle type, shock wave type, etc. Any method may be used. Moreover, hot air, heating steam, etc. are used as a heat source. The drying conditions may be appropriately selected depending on the size and type of the spray dryer, the concentration, viscosity, flow rate, etc. of the synthetic resin emulsion. The drying temperature is suitably from 100 ° C to 150 ° C, and it is desirable to set other drying conditions so that a sufficiently dried powder can be obtained within this drying temperature range.
As a method for adding the POA-modified PVA (B), a method in which an aqueous solution of the POA-modified PVA (B) is added to the emulsion (A) is a suitable method, but the POA-modified PVA (B) powder, flakes or pellets are added. The method of adding to an emulsion (A) is also mentioned. Moreover, when manufacturing emulsion (A) by emulsion polymerization, the method of adding POA modified PVA (B) to the latter half of emulsion polymerization (lump addition or continuous addition) is also mentioned.

  Moreover, it is desirable to use inorganic powder (antiblocking agent) for the purpose of improving the storage stability and redispersibility in water of the synthetic resin emulsion powder of the present invention. The inorganic powder may be added to the emulsion powder after spray drying and mixed uniformly. However, when the synthetic resin emulsion is sprayed in the presence of the inorganic powder during spray drying (simultaneous spraying), uniform mixing is performed. This is preferable. The inorganic powder is preferably fine particles having an average particle size of 0.1 to 100 μm. As the inorganic powder, fine inorganic powder is preferable, and calcium carbonate, clay, anhydrous silicic acid, aluminum silicate, white carbon, talc, alumina white and the like are used. Of these inorganic powders, anhydrous silicic acid is preferred. The amount of the inorganic powder used is preferably 30% by weight or less, more preferably 20% by weight or less, based on the performance, in view of performance. The lower limit is preferably 0.1% by weight or more, and more preferably 0.2% by weight or more. Organic fillers can also be used.

  In order to further improve the redispersibility of the synthetic resin emulsion powder in water, various water-soluble additives can be added. The additive is preferable because it is uniformly mixed when added to the synthetic resin emulsion before spray drying and spray dried. The amount of the water-soluble additive used is not particularly limited, and is appropriately controlled to such an extent that it does not adversely affect physical properties such as water resistance of the emulsion. Examples of such additives include hydroxyethyl cellulose, methyl cellulose, starch derivatives, polyvinyl pyrrolidone, polyethylene oxide, etc., water-soluble alkyd resins, water-soluble phenol resins, water-soluble urea resins, water-soluble melamine resins, water-soluble naphthalene sulfonic acids Resins, water-soluble amino resins, water-soluble polyamide resins, water-soluble acrylic resins, water-soluble polycarboxylic acid resins, water-soluble polyester resins, water-soluble polyurethane resins, water-soluble polyol resins, water-soluble epoxy resins, etc.

The synthetic resin emulsion powder of the present invention (average particle diameter of 1 to 1000 μm, preferably 2 to 500 μm) can be used as it is for various applications as it is, but is conventionally known as long as it does not impair the effects of the present invention. These various emulsions and emulsion powders can also be added and used.
The synthetic resin emulsion powder of the present invention is particularly useful as an admixture for hydraulic materials or a joint material for hydraulic materials. Here, examples of the hydraulic substance include hydraulic cements such as Portland cement, alumina cement, slag cement and fly ash cement, and hydraulic materials other than cement such as gypsum and plaster.
When the above-mentioned admixture for a hydraulic substance is used by blending it in a cement mortar composed of cement, aggregate and water, for example, the blending quantity of the admixture for hydraulic substance is 5 to 20% by weight with respect to the cement. Is preferred. Here, examples of the aggregate include fine aggregates such as river sand, crushed sand, colored sand and silica sand, and coarse aggregates such as river gravel and crushed stone.
When the synthetic resin emulsion powder of the present invention is used as a joining material for hydraulic substances, the synthetic resin emulsion powder is appropriately re-emulsified with water, and water such as concrete is used as the joining material (primer treatment material). The construction is carried out by applying to a hard substance substrate and then applying a hydraulic substance such as cement mortar. By using such a joining material, it is possible to impart excellent adhesion and durability, and excellent mechanical strength.

In order to further improve the dispersibility of the admixture for hydraulic substance and the joining material, various additives can be added. The additive is preferable because it is uniformly mixed when added to the synthetic resin emulsion before spray drying and spray dried. The amount of the water-soluble additive used is not particularly limited, and is appropriately controlled to such an extent that it does not adversely affect physical properties such as water resistance of the emulsion. Examples of such additives include hydroxyethyl cellulose, methyl cellulose, starch derivatives, polyvinyl pyrrolidone, polyethylene oxide, etc., water-soluble alkyd resins, water-soluble phenol resins, water-soluble urea resins, water-soluble melamine resins, water-soluble naphthalene sulfonic acids Examples include resins, water-soluble amino resins, water-soluble polyamide resins, water-soluble acrylic resins, water-soluble polycarboxylic acid resins, water-soluble polyester resins, water-soluble polyurethane resins, water-soluble polyol resins, and water-soluble epoxy resins.
The hydraulic material admixture and jointing material of the present invention include AE agent, water reducing agent, fluidizing agent, water retention agent, thickening agent, waterproofing agent, water proofing agent, etc. for use as an admixture for cement and mortar. A foaming agent etc. are used suitably.
The synthetic resin emulsion powder of the present invention can also be used for applications such as adhesives, paints and paper processing agents. For these uses, viscosity improvers, water retention agents, tackifiers, thickeners, pigment dispersants, stabilizers, and the like are used as appropriate.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the examples, “%” and “parts” represent “% by weight” and “parts by weight”, respectively, unless otherwise specified.

[Production of POA-modified PVA]
Production Example 1 (Production of PVA1)
In a 3 L reactor equipped with a stirrer, reflux condenser, nitrogen inlet, comonomer dropping port and initiator addition port, 400 g of vinyl acetate, 600 g of methanol, unsaturated monomer having POA group (monomer A ) 13.0 g was charged, and the system was purged with nitrogen for 30 minutes while bubbling nitrogen. Further, a comonomer solution having a concentration of 20% was prepared by dissolving an unsaturated monomer having a POA group (monomer A) in methanol as a delay solution, and nitrogen substitution was performed by bubbling nitrogen gas. The temperature of the reactor was increased, and when the internal temperature reached 60 ° C., 0.15 g of 2,2′-azobisisobutyronitrile (AIBN) was added to initiate polymerization. While the delay solution was added dropwise so that the monomer composition (ratio of vinyl acetate and monomer A) in the polymerization solution was constant, polymerization was performed at 60 ° C. for 3 hours and then cooled to stop the polymerization. The total amount of comonomer solution added until the polymerization was stopped was 55 ml. The solid content concentration when the polymerization was stopped was 19.8%. Subsequently, unreacted vinyl acetate monomer was removed while occasionally adding methanol under reduced pressure at 30 ° C. to obtain a methanol solution (concentration 24%) of POA-vinyl ester copolymer (POA-modified PVAc). Furthermore, 3.5 g of an alkaline solution (10% methanol solution of sodium hydroxide) was added to 496.5 g of a POA-modified PVAc methanol solution prepared by adding methanol (100.0 g of POA-modified PVAc in the solution). Saponification was carried out (POA-modified PVAc concentration of saponified solution 20%, molar ratio of sodium hydroxide to vinyl acetate units in POA-modified PVAc 0.0075). A gel-like product was formed in about 1 minute after the addition of the alkaline solution. This was pulverized with a pulverizer and allowed to stand at 40 ° C. for 1 hour to proceed with saponification. Neutralized. After confirming that the neutralization was completed using a phenolphthalein indicator, a white solid was obtained by filtration, 2000 g of methanol was added thereto, and the mixture was allowed to stand and washed at room temperature for 3 hours. After the above washing operation was repeated three times, the white solid obtained by centrifugal drainage was left in a dryer at 65 ° C. for 2 days to obtain POA-modified PVA (PVA1). The degree of polymerization of PVA1 was 520, the degree of saponification was 89.8 mol%, and the POA group modification amount (S) was 0.4 mol%.

Production Examples 2 to 22 (Production of PVA 2 to 22)
Charge amount of vinyl acetate and methanol, type of unsaturated monomer having POA group used during polymerization (Table 2), polymerization conditions such as addition amount, concentration of POA-modified PVAc during saponification, hydroxylation to vinyl acetate unit Various POA-modified PVAs (PVA2-22) were produced in the same manner as in Production Example 1 except that the saponification conditions such as the molar ratio of sodium were changed as shown in Tables 1 and 2.

Production Example 23 (Production of PVA23)
700 g of vinyl acetate and 300 g of methanol were charged into a 3 L reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet, and an initiator addition port, and the system was purged with nitrogen for 30 minutes while bubbling nitrogen. The temperature of the reactor was increased, and when the internal temperature reached 60 ° C., 0.25 g of 2,2′-azobisisobutyronitrile (AIBN) was added to start polymerization, and polymerization was performed at 60 ° C. for 3 hours. After cooling, the polymerization was stopped. The solid content concentration when the polymerization was stopped was 17.0%. Subsequently, unreacted vinyl acetate monomer was removed while sometimes adding methanol under reduced pressure at 30 ° C. to obtain a methanol solution (concentration 30%) of polyvinyl acetate (PVAc). Furthermore, saponification was carried out by adding 3.5 g of an alkaline solution (sodium hydroxide in 10% methanol) to 496.5 g of PVAc methanol solution prepared by adding methanol thereto (100.0 g of PVAc in the solution). (PVAc concentration of saponification solution 20%, molar ratio of sodium hydroxide to vinyl acetate units in PVAc 0.0075). A gel-like product was formed in about 1 minute after the addition of the alkaline solution. This was pulverized with a pulverizer and allowed to stand at 40 ° C. for 1 hour to proceed with saponification, and then 500 g of methyl acetate was added to leave the remaining alkali. Neutralized. After confirming that the neutralization was completed using a phenolphthalein indicator, a white solid was obtained by filtration, 2000 g of methanol was added thereto, and the mixture was allowed to stand and washed at room temperature for 3 hours. After repeating the above washing operation three times, the white solid obtained by centrifugal drainage was allowed to stand in a dryer at 65 ° C. for 2 days to obtain unmodified PVA (PVA23). The polymerization degree of PVA23 was 1700, and the saponification degree was 89.4 mol%.

Production Examples 24-26 (Production of PVA 24-26)
Various methods were used in the same manner as in Production Example 23 except that the saponification conditions such as the amount of vinyl acetate and methanol, the concentration of PVAc during saponification, and the molar ratio of sodium hydroxide to vinyl acetate unit were changed as shown in Table 1. Of unmodified PVA (PVA 24-26).

[Emulsion production example]
Emulsion production example 1 (production of EM-1)
A pressure-resistant autoclave equipped with a nitrogen inlet, a thermometer, and a stirrer was charged with 80 parts of a 9.5% aqueous solution of PVA-217 (manufactured by Kuraray Co., Ltd., polymerization degree 1700, saponification degree 88 mol%), and the temperature was raised to 60 ° C. After warming, nitrogen substitution was performed. After charging 80 parts of vinyl acetate, ethylene was pressurized to 4.9 MPa, and 2 g of 0.5% hydrogen peroxide aqueous solution and 0.3 g of 2% Rongalite aqueous solution were injected to initiate polymerization. When the residual vinyl acetate concentration reached 10%, ethylene was released, the ethylene pressure was set to 2.0 MPa, and 0.3 g of 3% hydrogen peroxide aqueous solution was injected to complete the polymerization. There was no aggregation during the polymerization and the polymerization stability was excellent, and an ethylene-vinyl acetate copolymer emulsion (EM-1) having a solid content concentration of 55% and an ethylene content of 18% by weight was obtained.

Emulsion production example 2 (production of EM-2)
In a glass container equipped with a reflux condenser, a dropping funnel, a thermometer, a nitrogen inlet, and a stirrer, PVA having a mercapto group at the end (polymerization degree 550, saponification degree 88.3 mol%, mercapto group content 3.3) × 10 ⁻⁵ equivalent / g) 5 parts and 90 parts of ion-exchanged water were charged and completely dissolved at 95 ° C. Next, after adjusting the pH to 4 with dilute sulfuric acid, 10 parts of methyl methacrylate, 10 parts of n-butyl acrylate and 0.1 part of n-dodecyl mercaptan were added while stirring at 150 rpm, and the temperature was raised to 70 ° C. after nitrogen substitution. . Polymerization was started by adding 5 parts of 1% potassium persulfate, and a mixture of 40 parts of methyl methacrylate, 40 parts of n-butyl acrylate and 0.4 part of n-dodecyl mercaptan was continuously added over 2 hours. . Three hours after the start of the polymerization, the conversion was 99.5% and the polymerization was terminated. A stable methyl methacrylate / n-butyl acrylate copolymer emulsion (EM-2) having a solid content concentration of 52.0% was obtained.

Example 1
100 parts of ethylene-vinyl acetate copolymer emulsion (A) (EM-1) solid content obtained in Emulsion Production Example 1 and POA-modified PVA (B) (PVA-1, polymerization degree 520, saponification degree 89.8 mol%) , POA group modification amount 0.4 mol%) 200% 5% aqueous solution and 11% calcium carbonate powder (average particle size 2 μm) with respect to the solid content of the emulsion were separately heated at 120 ° C. It was simultaneously sprayed in and dried to obtain a synthetic resin emulsion powder having an average particle size of 6 μm.

Examples 2-12, Comparative Examples 1-14
A synthetic resin emulsion powder was obtained in the same manner as in Example 1 except that PVA 2 to 26 obtained in Production Examples 2 to 26 were used instead of PVA 1 of Example 1.

Example 13
A synthetic resin emulsion powder was obtained in the same manner as in Example 1 except that EM-2 obtained in Emulsion Production Example 2 was used instead of EM-1 in Example 1.

Examples 14-15, Comparative Examples 15-16
A synthetic resin emulsion powder was obtained in the same manner as in Example 1 except that the ratio of PVA-1 in Example 1 was changed. The ratio of PVA-1 is shown in Table 3.

Example 16
A synthetic resin emulsion powder was obtained in the same manner as in Example 1 except that the calcium carbonate of Example 1 was changed to talc.

In Examples and Comparative Examples, synthetic resin emulsion powders produced using various PVA and emulsions were evaluated according to the following methods. The results are shown in Table 3.
[Redispersibility]
Filtration residue:
50 parts of the synthetic resin emulsion powder obtained in Examples and Comparative Examples and 50 parts of water were mixed, the redispersed emulsion was filtered through a 200 mesh stainless steel wire mesh, and the filtration residue was dried at 105 ° C. for 5 hours. The ratio of the filtration residue was measured.
Filtration residue (%) = (filter residue after drying / emulsion powder weight used for redispersion) × 100
The smaller the filtration residue is, the more the hydraulic material having excellent strength can be obtained when the emulsion powder is used as an admixture or jointing material for hydraulic substances. According to the present invention, an emulsion powder having a filtration residue of 5% or less (Table 3) can be obtained.
State after redistribution:
50 parts of the synthetic resin emulsion powder obtained in Examples and Comparative Examples and 50 parts of water were mixed, and the state of the redispersed emulsion was observed visually and with an optical microscope, and judged according to the following criteria.
◎ The redispersion liquid is uniform and the average particle size is 50 μm or less.
○ The re-dispersed liquid is uniform and there is no undispersed material.
Δ: Redispersed, but undispersed material is observed.
× Do not redistribute.
[Film-forming properties]
50 parts of the synthetic resin emulsion powder obtained in Examples and Comparative Examples and 50 parts of water were mixed, and the redispersed emulsion was cast on a glass plate at 50 ° C. and dried. It was judged.
○ A uniform film is obtained and a tough film is obtained.
△ Although it becomes a film, it is fragile.
X A uniform film cannot be obtained.
[viscosity]
50 parts of the synthetic resin emulsion powder obtained in Examples and Comparative Examples and 50 parts of water were mixed, and the redispersed emulsion was brought to a liquid temperature of 30 ° C., and the viscosity was measured at 20 rpm with a B-type viscometer.
[Mortar performance]
The synthetic resin powder emulsion powders obtained in Examples and Comparative Examples were used as admixtures for hydraulic materials and joint materials for hydraulic materials, and the physical properties were evaluated.
(Performance evaluation of admixtures for hydraulic materials)
Performance as an admixture for cement mortar Properties test of cement mortar 1) Mortar composition:
Hydraulic material admixture / cement weight ratio = 0.10
Sand / cement weight ratio = 3.0, water / cement weight ratio = 0.7
2) Slump value: measured according to JIS A-1171 3) Flow value: measured according to JIS R-5201 3) Bending strength: measured according to JIS R-5201 4) Compressive strength: according to JIS R-5201 Measured

The synthetic resin emulsion powder of the present invention is excellent in redispersibility, and a synthetic resin emulsion powder having a higher viscosity can be obtained.
By using the synthetic resin emulsion powder of the present invention, it is excellent in dispersibility in hydraulic substances such as cement mortar, and when mixed with hydraulic substances such as cement mortar, both water reduction and viscosity increase can be obtained. Viscosity and water retention of hydraulic substances are increased, troweling and spreading are improved, mortar setting time and watering time are delayed, so workability is remarkably improved and cracking is also suppressed. Is obtained. Further, by using the synthetic resin emulsion powder of the present invention, a joining material for a hydraulic substance that is excellent in adhesiveness and durability and further excellent in mechanical strength can be obtained.

Claims (7)

An emulsion having a vinyl alcohol polymer as a dispersant and a polymer having one or more unsaturated monomer units selected from ethylenically unsaturated monomers and diene monomers as a dispersoid (A ), A vinyl alcohol polymer containing a polyoxyalkylene group represented by the following general formula (I) in the side chain, the viscosity average polymerization degree of the vinyl alcohol polymer is 100 to 3000, and saponification A composition containing a polyoxyalkylene-vinyl alcohol polymer (B) having a degree of 70.0 to 99.5 mol% or more and a polyoxyalkylene modification amount of 0.1 to 10 mol% is dried. Synthetic resin emulsion powder obtained.

(Wherein R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, m and n represent a repeating unit of each (poly) oxylene unit, and 0 ≦ m ≦ 10, 3 ≦ n ≦ 20.)   The synthetic resin emulsion powder according to claim 1, wherein the content of the polyoxyalkylene group represented by the general formula (I) in the polyoxyalkylene-vinyl alcohol polymer (B) is 2.0 to 50 parts by weight. A polyoxyalkylene-vinyl alcohol polymer (B) is obtained by copolymerizing a macromonomer having a polyoxyalkylene group represented by the following general formula (II) with a vinyl ester and then saponifying the polyoxyalkylene-vinyl alcohol polymer (B). The synthetic resin emulsion powder according to claim 1 or 2, which is an oxyalkylene-vinyl alcohol polymer.

(Wherein R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, m and n represent a repeating unit of each (poly) oxylene unit, and 0 ≦ m ≦ 10, 3 ≦ n ≦ 20, R3 represents a hydrogen atom or a —COOM group, M represents a hydrogen atom, an alkali metal or an ammonium group, and R4 represents a hydrogen atom, a methyl group or a —CH ₂ —COOM group. , M is as defined above, X represents —O—, —CH ₂ —O—, —CO—, —CO—O— or —CO—NR 5, wherein R 5 represents a hydrogen atom or a group having 1 to 4 carbon atoms. Represents a saturated alkyl group.)   The synthetic resin emulsion powder according to claim 1, wherein 1 to 50 parts by weight of the polyoxyalkylene-vinyl alcohol polymer (B) is blended with 100 parts by weight of the solid content of the emulsion (A).   The polymer having one or more unsaturated monomer units selected from ethylenically unsaturated monomers and diene monomers is a vinyl ester polymer or an olefin-vinyl ester copolymer. The synthetic resin emulsion powder according to claim 1.   The synthetic resin emulsion powder according to claim 1, wherein the drying is spray drying.   Furthermore, the synthetic resin emulsion powder in any one of Claims 1-6 containing an inorganic powder.