Aqueous water absorption preventive material

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a water-based water absorption inhibitor that is mainly applied to a porous material to prevent water absorption of the material.

【0002】

Porous materials include, for example, porous civil engineering and building materials, and more specifically, exposed concrete, lightweight concrete, precast concrete, lightweight foamed concrete (ALC), mortar, joint mortar, asbestos cement board, pulp cement board, and wood wool. Cement board, cement-based extrusion board, cement board with glass fiber (GRC), cement board with carbon fiber, calcium silicate board, plaster board, hard board, plaster, plaster plaster, dolomite plaster, block, brick, tile, tile, Examples thereof include materials mainly composed of inorganic materials such as natural stone, artificial stone, glass wool, rock wool and ceramic fiber, and materials mainly composed of organic materials such as wood, plywood and particle board.

【0003】

[Conventional technology]

Conventionally, as a method of imparting water absorption prevention properties to porous civil engineering and building materials, a material obtained by dissolving or dispersing a silicone-based, acrylic-based, acrylic silicone-based, urethane-based, ester-based, or oil-based resin or monomer is applied to the material. A method of permeating and drying (polymerizing), a method of applying a fluorine paint such as a room temperature dry type one-component fluorine paint, a reaction-curing two-component fluorine paint, and forming a coating film on the material surface, a permeable water absorption inhibitor A method of applying and applying a fluorine paint on the coating is known.

【0004】

In the method of applying the fluorine paint, since the surface of the porous civil engineering / building material is generally not smooth, pinholes are likely to occur in the coating film, and the coating film may be peeled off by the water invading from the pinholes. Further, since a glossy coating film is formed, not only the base material and texture of the material are impaired, but also the deteriorated state of the base is obscured.

【0005】

On the other hand, permeable water absorption preventive materials such as silicone and acrylic have the function of preventing water from entering and dissipating moisture without forming a coating film on the surface of porous civil engineering and building materials. Often used favorably. However, while the ability to prevent water ingress is maintained for a very long time, under conditions where pressure is applied to the porous material, such as when exposed to heavy wind and rain or when the outer wall is in constant contact with snow in snowy areas. Has the disadvantages of maintaining water absorption prevention and water repellency of the surface and preventing deterioration of the surface for a short period of time.

【0006】

The method of applying the permeable water absorption preventive material and then applying the fluorine paint on it is an excellent method of preventing the intrusion of water from the pinhole, which is a drawback of the fluorine paint, by the water absorption preventive material. However, it has the disadvantage that the painting process is doubled and the cost is very high.

【0007】

[Problems to be Solved by the Invention]

The subject of the present invention is to keep the material material and texture alive even under conditions where pressure is applied to the porous material, such as when exposed to heavy wind and rain or when the outer wall is constantly in contact with snow in a snowy area. It is an object of the present invention to provide a water-based water absorption preventive material capable of maintaining good water absorption prevention performance for a very long period of time.

【0008】

[Means for solving problems]

As a result of diligent studies to solve the above problems, the present inventors have good permeability to porous civil engineering and building materials only with the organic silicon compound emulsion, but the water absorption prevention performance, the water repellent effect and the surface under pressure are obtained. On the other hand, the fluororesin emulsion alone does not sufficiently permeate and the water invasion prevention effect cannot be said to be sufficient. Therefore, the organic silicon compound emulsion and the fluororesin emulsion are not sufficient. The present invention has been completed by finding that by mixing the film-forming aid and the film-forming aid, it is possible not only to compensate for each other's shortcomings but also to exert synergistic effects.

【0009】

That is, the present invention comprises an organosilicon compound emulsion, a fluororesin emulsion and a film-forming aid, and the organosilicon compound emulsion is (A) the following general formula (1); [0010]

[Chemical 3]

<img file="JP2003026461A_D0001.tif" />(In the formula, R¹Indicates an alkyl group having 4 to 18 carbon atoms. R²Indicates an alkyl group having 1 to 6 carbon atoms. n is 1 or 2.

【0011】

Alkoxyalkoxysilane represented by (B) the following general formula (2); [0012]

[Chemical 4]

<img file="JP2003026461A_D0002.tif" />(In the formula, R³Indicates an alkyl group having 4 to 18 carbon atoms. R⁴Indicates an aminoalkyl group. R⁵Indicates an alkyl group having 1 to 6 carbon atoms. a is 0 to 2 and b is 1 to 3. However, the sum of a and b is 3 or less.

【0013】

It contains an alkylalkoxysilane having an aminoalkyl group represented by (C) and a surfactant (C), and the blending ratio of the organosilicon compound component (B) to the organosilicon compound component (A) is 20% by weight or more. The present invention relates to a water-based water absorption preventive material, which is largely 40% by weight or less, and the amount of the surfactant (C) is 1 to 20% by weight of the total amount of the organosilicon compound components (A) and (B).

【0014】

BEST MODE FOR CARRYING OUT THE INVENTION

The water-based water absorption inhibitor of the present invention comprises an organosilicon compound emulsion, a fluororesin emulsion and a film-forming aid, and the organosilicon compound emulsion is (A) an alkylalkoxysilane and (B) an alkylalkoxysilane having an aminoalkyl group. And (C) it contains a surfactant.

【0015】

The above (A) alkylalkoxysilane is a compound represented by the following general formula (1).

【0016】

[Chemical 5]

<img file="JP2003026461A_D0003.tif" />【0017】

In the formula, R¹Is an alkyl group with 4 to 18 carbon atoms, R²Indicates an alkyl group having 1 to 6 carbon atoms, and n is 1 or 2.

【0018】

Examples of the alkyl group having 4 to 18 carbon atoms include a butyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group and an octadecyl group.

【0019】

Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and the like.

【0020】

Specific examples of such alkylalkoxysilanes include butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, octyllipopoxysilane, and decyltrimethoxy. Examples thereof include silane, dodecyltriethoxysilane, octadecyltrimethoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, and dibutyldimethoxysilane. Above all, R¹Hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, and octyltriethoxysilane having 6 or more carbon atoms in the alkyl group of the above are preferably used.

【0021】

Further, as is well known in the art, condensed dimers and trimers of the above silanes or other oligomers can be used. Here, the oligomer means a low polymer having 2 to 100 monomers (constituent units) (n). If desired, a mixture of various silanes may be used, or a co-oligomer of mixed silanes may be used.

【0022】

The above (B) alkylalkoxysilane having an aminoalkyl group is a compound represented by the following general formula (2).

【0023】

[Chemical 6]

<img file="JP2003026461A_D0004.tif" />【0024】

In the formula, R³Indicates an alkyl group having 4 to 18 carbon atoms. R⁴Indicates an aminoalkyl group. R⁵Indicates an alkyl group having 1 to 6 carbon atoms. a is 0 to 2 and b is 1 to 3. However, the sum of a and b is 3 or less.

【0025】

Examples of the alkyl group having 4 to 18 carbon atoms include a butyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group and an octadecyl group.

【0026】

The aminoalkyl group is H.₂N (CH₂)₃-, H₂N (CH₂)₂NH (CH)₂)₂-, H₂N (CH₂)₂NH (CH)₂)₃-, H₂N (CH₂)₂-, H₃CNH (CH)₂)₃-, C₂H₅NH (CH)₂)₃-, H₃CNH (CH)₂)₂-, C₂H₅NH (CH)₂)₂-, H₂N (CH₂)₄-, H₂N (CH₂)₅-Etc.

【0027】

Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and the like.

【0028】

Specific examples of the alkylalkoxysilane having such an aminoalkyl group include N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and the like. Examples thereof include 4-aminobutyltriethoxysilane. Of these, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane are preferably used.

【0029】

The blending ratio of the organosilicon compound component (B) to the organosilicon compound component (A) is more than 20% by weight and 40% by weight or less, preferably 21 to 37% by weight, and more preferably 22 to 35% by weight. .. When the blending ratio of the organosilicon compound component (B) is 20% by weight or less, the water repellency after applying the water-based water absorption inhibitor to the base material is lowered. Further, when the compounding ratio of the organosilicon compound component (B) exceeds 40% by weight, the permeability of the water-based water absorption preventive material to the base material deteriorates.

【0030】

When the water-based water absorption inhibitor of the present invention is used for a porous civil engineering building material having high water absorption, in addition to the alkylalkoxysilane (A) represented by the general formula (1), the following general formula (3) In some cases, favorable results may be obtained by using the organopolysiloxane (A') represented by.

【0031】

[Chemical 7]

<img file="JP2003026461A_D0005.tif" />【0032】

In the formula, R⁶Is an alkyl group with 1 to 18 carbon atoms, R⁷Indicates an alkyl group having 1 to 6 carbon atoms. x is 0, 1, 2 or 3, and the average value is 0.8 to 1.8. y is 0, 1, 2 or 3, and the average value is 0.01 ~ 2. z is 0, 1, 2 or 3, and the average value is 0 to 0.5. However, the total of the average values of x, y, and z is 3.5 or less.

【0033】

Examples of the alkyl group having 1 to 18 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group and an octadecyl group.

【0034】

Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and the like.

【0035】

The organopolysiloxane is, for example, an empirical formula CH obtained by reacting methyltrichlorosilane or phenyltrichlorosilane with ethanol in water.₃Si (OC₂H₅)_0.8O_1.1Or C₆H₅Si (OC₂H₅)_0.72O_1.14Organopolysiloxane represented by.

【0036】

The organopolysiloxane preferably has a viscosity of 10 to 10000 mPa / s at 25 ° C.

【0037】

The ratio (weight ratio) of the alkylalkoxysilane (A) to the organopolysiloxane (A') is (A) :( A') = 1: 0 to 1. When the weight ratio of the organopolysiloxane (A') exceeds 1, the permeability of the water-based water absorption inhibitor to the substrate tends to deteriorate.

【0038】

The water-based water absorption inhibitor of the present invention contains a known surfactant (C). As the surfactant, any of nonionic, cationic and anionic surfactants can be used, but nonionic surfactants are preferably used.

【0039】

Examples of the nonionic surfactant include polyoxyethylene lauryl ether (Nonion K-204, Nonion K-240; manufactured by NOF Corporation) as an ether type. Examples of the alkylphenol type include polyoxyethylene nonylphenyl ether (Nonion NS-215; manufactured by NOF), polyoxyethylene octylphenol ether (Nonion HS-204, HS-206, HS-215; manufactured by NOF) and the like. Examples of the ester type include polyoxyethylene monoolate (Nonion O-6; manufactured by NOF CORPORATION) and the like. Examples of the sorbitan ester type include sorbitan monolaurate (Nonion LP-20R; manufactured by NOF CORPORATION) and the like. Examples of the sorbitan ester ether type include polyoxyethylene sorbitan monolaurate (Nonion LT-221; manufactured by Nippon Yushi) and polyoxyethylene sorbitan monostearate (Nonion ST-221; manufactured by Nippon Yushi). The above-mentioned surfactant may be used alone or in combination of two or more.

【0040】

The amount of the surfactant used is 1 to 20% by weight, preferably 3 to 15% by weight, based on the total amount of the organosilicon compound components (A) and (B). When the amount of the surfactant used is less than 1% by weight, the permeability into the base material is poor and the surface of the base material becomes wet. On the other hand, if it exceeds 20% by weight, the water absorption prevention property deteriorates under the condition where pressure is applied.

【0041】

The organosilicon compound emulsion used in the present invention may contain a buffer substance in order to stabilize its pH value in the range of 6 to 9. At such pH values, alkylalkoxysilanes are extremely stable to hydrolysis. As the buffer material, alkali metal salts of carboxylic acid, phosphoric acid, carbonic acid and sulfuric acid, alkaline earth metal salts and ammonium salts are preferable, and sodium carbonate and sodium hydrogen carbonate are particularly preferable. The preferred amount of buffer material is 1% by weight or less of the total amount of the organosilicon compound.

【0042】

The method for producing the organosilicon compound emulsion used in the present invention is not particularly limited, but usually, at room temperature, a mixed solution of water and a surfactant is stirred at high speed with a homomixer, an ultradisperser, a high-pressure homogenizer, or the like, and then. It can be produced by gradually adding an organosilicon compound and subsequently stirring at high speed.

【0043】

The fluororesin emulsion used in the present invention is not particularly limited as long as it is an emulsion of a resin containing a fluorine atom. Examples of the fluororesin include a copolymer composed of two or more kinds of olefins containing a fluorine atom, a copolymer of an olefin containing a fluorine atom and a hydrocarbon monomer, and two or more kinds of olefins containing a fluorine atom. Examples thereof include a mixture of the copolymer and a thermoplastic acrylic resin.

【0044】

Examples of the fluorine atom-containing olefin include fluoroolefins such as tetrafluoroethylene, chlorotrifluoroethylene, and vinylidene fluoride. Preferred are chlorotrifluoroethylene and vinylidene fluoride.

【0045】

Examples of the hydrocarbon monomer include vinyl ethers such as cycloalkyl vinyl ether, alkyl vinyl ether, and hydroxyalkyl vinyl ether, vinyl esters such as aliphatic carboxylic acid vinyl ester, methyl (meth) acrylate, ethyl (meth) acrylate, and (meth). ) Examples of (meth) acrylic acid esters such as propyl acrylate and butyl (meth) acrylate. Preferred are methyl (meth) acrylate and ethyl (meth) acrylate. In addition, in this specification, (meth) acrylic acid means acrylic acid and methacrylic acid.

【0046】

Examples of the thermoplastic acrylic resin include homopolymers such as methyl methacrylate, ethyl methacrylate, and isobutyl methacrylate and copolymers thereof, and one or more of these polymers can be used.

【0047】

The fluororesin emulsion used in the present invention contains a known surfactant. As the surfactant, any of nonionic, cationic and anionic surfactants can be used.

【0048】

As the fluororesin emulsion, a commercially available fluororesin emulsion may be used. Specific examples thereof include vinylidene fluoride fluororesin emulsion (VEW3300, Zeffle SE-310; manufactured by Daikin Industries, Ltd.) and fluoroolefin vinyl ether fluororesin emulsion (Lumiflon FE-3000, FE-4300; manufactured by Asahi Glass Co., Ltd.). Etc. can be used.

【0049】

The blending ratio of the organosilicon compound emulsion and the fluororesin emulsion is usually in the range of 1: 0.01 to 20, preferably in the range of 1: 0.1 to 10, as the weight ratio of the organosilicon compound and the fluororesin. When the ratio of the fluororesin is less than 0.01, the surface of the porous material tends to be deteriorated easily, and the water repellency of the surface of the porous material tends to be difficult to maintain. On the other hand, if the proportion of fluororesin exceeds 20, the base material and texture of the porous material may be impaired due to the formation of a coating film to produce luster, or the material may swell and float due to impaired moisture permeability. It is not preferable to have it.

【0050】

The film forming aid used in the present invention is not particularly limited as long as it is generally used for emulsion coating materials. For example, carbitol, butyl carbitol, butyl carbitol acetate, propylene glycol monomethyl ether acetate, texanol, diethyl adipic acid and the like can be mentioned. Preferably, it is butyl carbitol acetate, texanol, diethyl adipic acid.

【0051】

The ratio of the fluororesin to the film forming aid is preferably 1: 0.01 to 0.2 in terms of weight ratio. If the ratio of the film-forming auxiliary is less than 0.01, the film-forming state of the fluororesin may be deteriorated and the coating appearance may be impaired. It is uneconomical if the proportion of film-forming aid exceeds 0.2.

【0052】

The method for producing the water-based water absorption inhibitor of the present invention is not particularly limited, but usually, at room temperature, an organosilicon compound emulsion, a fluororesin emulsion and a film forming aid are mixed at high speed with a stirrer such as a homomixer, an ultradispersor, or a high-pressure homogenizer. It can be produced by stirring.

【0053】

The water-based water absorption inhibitor of the present invention can be prepared and used with a resin solid content of 2 to 60% by weight, preferably 5 to 30% by weight, using water and / or a solvent soluble in water. If the resin solid content is less than 2% by weight, not only the original performance of the water-based water absorption preventive material is not exhibited, but also a large amount must be applied in order to exert the effect, so that it takes time to dry, which is not preferable. Further, when the resin solid content exceeds 60% by weight, the viscosity is high, the permeability to the porous material is deteriorated, and a wet color tends to occur.

【0054】

When preparing the water-based water absorption preventive material of the present invention, a preservative, a fungicide, an algae-proofing agent, an anti-termite agent, an ultraviolet absorber and the like may be added secondarily.

【0055】

In order to apply the water-based water absorption inhibitor of the present invention to the porous material, a roller, a brush, a spray or the like may be used, and in some cases, a dipping method may be used. Further, as a drying method, it may be left at room temperature to dry, or it may be sun-dried or heat-dried.

【0056】

Examples of the porous material to which the water-based water absorption inhibitor of the present invention is applied include porous civil engineering and building materials, and more specifically, exposed concrete, lightweight concrete, precast concrete, lightweight foamed concrete (ALC), mortar, joint mortar, and the like. Asbestos cement board, pulp cement board, wood wool cement board, cement-based extrusion molding board, glass fiber-containing cement board (GRC), carbon fiber-containing cement board, calcium silicate board, gypsum board, hard board, plaster, plaster plaster, dolomite Materials mainly composed of inorganic materials such as plaster, blocks, bricks, tiles, tiles, natural stones, artificial stones, glass wool, rock wool, ceramic fibers, and materials mainly composed of organic materials such as wood, plywood, and particle board. Can be mentioned.

【0057】

The water-based water absorption preventive material of the present invention can be used for water such as rainwater leakage due to heavy wind and rain, deterioration of materials due to acid rain, stain penetration, salt damage due to seawater, frost damage in cold regions, and white flowers due to elution of salt in the material. Various problems caused by it can be solved.

【0058】

The water-based water absorption preventive material of the present invention, or the water-based water absorption preventive material of the present invention to which a resin emulsion such as acrylic, urethane, or acrylic silicone is added, and a pigment, a settling inhibitor, an anti-dripping material, a matting agent, etc. It is also possible to add and mix paint constituents such as an ultraviolet absorber to obtain a water-based permeable water-repellent paint.

【0059】

Further, by further adding a preservative, a fungicide, an algae-proofing agent, an anti-termite agent, etc. to the above-mentioned paint constituents, a water-based permeable water-repellent paint particularly suitable for wood, bamboo, etc. can be obtained. [0060]

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

【0061】

Example 1 A mixture of 50 parts by weight of water and 3 parts by weight of sorbitan monolaurate (LP-20R; manufactured by Nippon Yushi) was stirred at high speed with a homomixer, then 38 parts by weight of hexyltriethoxysilane and N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane 9 parts by weight was gradually added and stirred at high speed with a homomixer to obtain an organosilicon compound emulsion.

【0062】

20 parts by weight of the obtained organic silicon emulsion, 20 parts by weight of a fluoroolefin vinyl ether fluororesin emulsion (Lumiflon FE-4300, resin solid content 50% by weight; manufactured by Asahi Glass Co., Ltd.), 2 parts by weight of diethyl adipate and 58 parts by weight of water. Was stirred at high speed with a homomixer to obtain the water-based water absorption inhibitor of the present invention.

【0063】

Example 2 A mixture of 50 parts by weight of water and 3 parts by weight of sorbitan monolaurate (LP-20R; manufactured by Nippon Yushi) was stirred at high speed with a homomixer, and then 37 parts by weight of octyltriethoxysilane and N- (2-aminoethyl) were mixed. ) -3-Aminopropyltrimethoxysilane 10 parts by weight was gradually added and stirred at high speed with a homomixer to obtain an organosilicon compound emulsion.

【0064】

20 parts by weight of the obtained organic silicon emulsion, 20 parts by weight of a fluoroolefin vinyl ether fluororesin emulsion (Lumiflon FE-4300, resin solid content 50% by weight; manufactured by Asahi Glass Co., Ltd.), 2 parts by weight of diethyl adipate and 58 parts by weight of water. Was stirred at high speed with a homomixer to obtain the water-based water absorption inhibitor of the present invention.

【0065】

Example 3 A mixture of 50 parts by weight of water and 3 parts by weight of sorbitan monolaurate (LP-20R; manufactured by Nippon Yushi) was stirred at high speed with a homomixer, then 35 parts by weight of hexyltriethoxysilane, and empirical CH.₃Si (OC₂H₅)_0.8O_1.14 parts by weight of organopolysiloxane (average molecular weight about 650 and viscosity about 20 mPa / s) and 8 parts by weight of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane are gradually added and stirred at high speed with a homomixer. Then, an organosilicon compound emulsion was obtained.

【0066】

24 parts by weight of the obtained organic silicon emulsion, 24 parts by weight of vinylidene fluoride fluororesin emulsion (VEW3300, resin solid content 50% by weight; manufactured by Daikin Industries, Ltd.), 2 parts by weight of diethyl adipate and 50 parts by weight of water are homogenized. The water-based water absorption inhibitor of the present invention was obtained by stirring at high speed with a mixer.

【0067】

Example 4 A mixture of 50 parts by weight of water and 3 parts by weight of sorbitan monolaurate (LP-20R; manufactured by Nippon Yushi) was stirred at high speed with a homomixer, and then 33 parts by weight of hexyltriethoxysilane and empirical CH.₃Si (OC₂H₅)_0.8O_1.14 parts by weight of organopolysiloxane (average molecular weight about 650 and viscosity about 20 mPa / s) and 10 parts by weight of 3-aminopropyltriethoxysilane were gradually added and stirred at high speed with a homomixer to obtain an organosilicon compound emulsion. ..

【0068】

24 parts by weight of the obtained organic silicon emulsion, 24 parts by weight of vinylidene fluoride fluororesin emulsion (VEW3300, resin solid content 50% by weight; manufactured by Daikin Industries, Ltd.), 2 parts by weight of diethyl adipate and 50 parts by weight of water are homogenized. The water-based water absorption inhibitor of the present invention was obtained by stirring at high speed with a mixer.

【0069】

Example 5 A mixture of 50 parts by weight of water and 3 parts by weight of sorbitan monolaurate (LP-20R; manufactured by Nippon Yushi) was stirred at high speed with a homomixer, then 38 parts by weight of hexyltrimethoxysilane and N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane 9 parts by weight was gradually added and stirred at high speed with a homomixer to obtain an organosilicon compound emulsion.

【0070】

36 parts by weight of the obtained organic silicon emulsion, 12 parts by weight of vinylidene fluoride fluororesin emulsion (Zefle SE-310, resin solid content 50% by weight; manufactured by Daikin Industries, Ltd.), 1 part by weight of diethyl adipate and 51 parts by weight of water. The part was stirred at high speed with a homomixer to obtain the water-based water absorption inhibitor of the present invention.

【0071】

Example 6 A mixture of 50 parts by weight of water and 3 parts by weight of sorbitan monolaurate (LP-20R; manufactured by Nippon Yushi) was stirred at high speed with a homomixer, then 38 parts by weight of decyltrimethoxysilane and N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane 9 parts by weight was gradually added and stirred at high speed with a homomixer to obtain an organosilicon compound emulsion.

【0072】

12 parts by weight of the obtained organic silicon emulsion, 36 parts by weight of vinylidene fluoride fluororesin emulsion (Zefle SE-310, resin solid content 50% by weight; manufactured by Daikin Industries, Ltd.), 3 parts by weight of diethyl adipate and 49 parts by weight of water. The part was stirred at high speed with a homomixer to obtain the water-based water absorption inhibitor of the present invention.

【0073】

Comparative example 1 Fluoroolefin vinyl ether fluororesin emulsion (Lumiflon FE-4300, resin solid content 50% by weight; manufactured by Asahi Glass Co., Ltd.) 30 parts by weight, diethyl adipic acid by 3 parts by weight and water by 67 parts by weight are stirred at high speed with a homomixer to absorb water. Obtained a preventive material.

【0074】

Comparative example 2 A mixture of 50 parts by weight of water and 3 parts by weight of sorbitan monolaurate (LP-20R; manufactured by Nippon Yushi) was stirred at high speed with a homomixer, then 38 parts by weight of hexyltriethoxysilane and N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane 9 parts by weight was gradually added and stirred at high speed with a homomixer to obtain an organosilicon compound emulsion.

【0075】

40 parts by weight of the obtained organosilicon emulsion and 60 parts by weight of water were stirred at high speed with a homomixer to obtain a water-based water absorption inhibitor.

【0076】

Test example A JIS mortar (70 x 70 x 20 mm) conforming to JIS R-5201 was used as a specimen, and the water-based water absorption inhibitor obtained in Examples and Comparative Examples was applied to this as a specimen at 300 g / m.²Was applied to the entire surface at the ratio of. In addition, the one to which nothing was applied was used as a control. The obtained specimen was cured in a thermo-hygrostat at a temperature of 20 ° C. and a relative humidity of 65% RH for 7 days, and then subjected to the performance test of the water absorption ratio shown below. Next, using a sunshine weather meter (Due cycle sunshine super long life weather meter WEL-SUN-DCH type, manufactured by Suga Test Instruments Co., Ltd.), black panel temperature: 63 ° C, humidity: about 50%, precipitation conditions : Accelerated weather resistance test was conducted for 12 minutes out of 60 minutes under the test conditions of rainfall. The specimen after 5000 hours was subjected to the performance test shown below.

【0077】

Water absorption ratio The obtained coated and uncoated specimens were immersed in water, left to stand under atmospheric pressure of normal pressure, 0.5 MPa (gauge pressure) and 1 MPa (gauge pressure) for 15 minutes, and then the excess water of the sample taken out was taken out. Weighed (g) after wiping with a dry cloth, and calculated by the following formula. The results are shown in Table 1. When the water absorption ratio is 0.2 or less, it can be judged that the water absorption prevention property is excellent.

【0078】

[Number 1]

<img file="JP2003026461A_D0006.tif" />【0079】

Water repellency 0.5 ml of water droplets were dropped on the coated surface, and the surface condition was visually observed. The evaluation criteria are as follows. The results are shown in Table 2. : Good water repellency. Δ: Slightly poor water repellency (wet marks remain where water droplets are dropped). ×: No water repellency (water droplets are absorbed).

【0080】

Contact angle Water droplets with a diameter of 2 mm were dropped on the coated surface, left for 1 minute, and then measured with a contact angle meter (CA-S150 type; manufactured by Kyowa Interface Science Co., Ltd.). The results are shown in Table 2.

【0081】

[table 1]

<img file="JP2003026461A_D0007.tif" />【0082】

[Table 2]

<img file="JP2003026461A_D0008.tif" />【0083】

From Tables 1 and 2, it can be seen that the water-based water absorption preventive materials of Examples 1 to 6 can maintain the water absorption prevention performance for a very long period of time even under the condition that pressure is applied to the porous material.

【0084】

[Effect of the invention]

According to the present invention, good water absorption prevention performance is maintained for a very long period of time even under conditions where pressure is applied to a porous material such as when exposed to heavy wind and rain or when the outer wall is constantly in contact with snow in a snowy area. At the same time, it is possible to provide a water-based water absorption preventive material capable of protecting the surface of the material while keeping the base material and texture of the material.