JP2002226776A - Water absorption inhibitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel water absorption inhibitor which exhibits an excellent effect on the inhibition of water absorption/penetration, the improvement of weatherability and the like without limiting base materials to be applied, e.g. in neutral base materials and the like, and is free from toxicity, excels in handling safety and does not adversely affect the environment. SOLUTION: The water absorption inhibitor is composed of a combination of an aqueous emulsion comprising a dispersion containing a curable organosilicon compound and a germanium catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-absorbing agent which is excellent as a coating agent for a substrate for civil engineering and construction, for example, for preventing water absorption and permeability and improving weather resistance.

[0002]

2. Description of the Related Art Conventionally, in the field of civil engineering and construction, an aqueous silane-based permeable water-absorbing agent (Japanese Patent Application No. 01-33308) has been proposed in order to impart excellent weather resistance and water-absorbing property to a substrate.
5, silane-based osmotic water-absorbing agents and water-based silane-based paints, such as those disclosed in Japanese Patent Application No. 0300026) and water-based acrylic silicone weather-resistant paints, are often used.
However, these silane-based osmotic water-absorbing agents exhibit their functions only when the substrate to be coated is strongly alkaline concrete, and impart water repellency and weather resistance. Specifically, the target to be used is limited. On the other hand, to solve this problem, tin-based catalysts are used as curing catalysts so that the applied water-absorbing inhibitor (paint) can be cured irrespective of the type of the base material. Because of its toxicity, there is a problem that handling is restricted in the preparation stage and the surrounding environment after coating may be adversely affected.

[0003]

Therefore, the problem to be solved by the present invention is not limited to the target base material, for example, even in a neutral base material, prevention of water absorption / permeability and weather resistance. An object of the present invention is to provide a novel water-absorbing agent which exhibits an excellent effect on the improvement of water-repellency and the like, has no toxicity, is excellent in handling safety, and has no adverse effect on the environment.

[0004]

Means for Solving the Problems The present inventors have intensively studied to solve the above-mentioned problems. As a result, a dispersion containing a curable organosilicon compound as a water-absorbing agent that exhibits the effect of preventing water absorption and improving weather resistance when applied to a substrate and cured. In addition, they have found that a novel water-absorbing agent that can solve the above problems can be obtained by using a combination of a germanium catalyst as a curing catalyst. That is, the water absorption inhibitor according to the present invention is characterized by comprising a combination of an aqueous emulsion containing a dispersion containing a curable organosilicon compound, and a germanium catalyst.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the water absorption inhibitor according to the present invention will be specifically described. The water absorption inhibitor according to the present invention is characterized by comprising a combination of an aqueous emulsion containing a dispersion containing a curable organosilicon compound, and a germanium catalyst as a curing catalyst. here,
In the water absorption inhibitor of the present invention, the combination of the aqueous emulsion (a) containing the dispersion containing the curable organosilicon compound and the germanium catalyst (b) is a so-called two-pack type use form, and And (b) may be a combination in an unmixed state, or may be a so-called one-pack type of use in which (a) and (b) are already mixed. Further, some other combination may be used, but it is not particularly limited to these. However, among these combinations, the combination of so-called two-pack type usage forms is particularly preferable in consideration of the storage stability of the water absorption preventing agent of the present invention.

As the water absorption inhibitor of the present invention, in addition to the aqueous emulsion (a) containing the above-mentioned dispersion containing the curable organosilicon compound and the germanium catalyst (b), any medium or additive may be used. It may be a combination. Hereinafter, the aqueous emulsion containing the dispersion containing the curable organosilicon compound, the germanium catalyst, and the water absorption inhibitor will be separately described in detail. [Aqueous emulsion containing a dispersion containing a curable organosilicon compound] The aqueous emulsion containing a dispersion containing a curable organosilicon compound in the present invention (hereinafter, referred to as an aqueous emulsion (a)) serves as a dispersion medium. It is preferable that the aqueous medium is an aqueous emulsion in which a dispersion containing a curable organosilicon compound is dispersed in fine particles, and the aqueous medium further contains an emulsifier, a pH adjuster, and the like. Although preferred, it is not particularly limited.

As the dispersion containing the curable organosilicon compound, micelle-like fine particles in which the molecules of the curable organosilicon compound are aggregated and emulsified in an aqueous medium, or dispersed in an organic solvent A solution obtained by dissolving a curable organosilicon compound becomes finer as droplets (oil droplets).
Preferable examples include fine particles, but are not particularly limited thereto. The particle size of the dispersion containing the curable organosilicon compound is 1 to 10 μm.
Is more preferable, more preferably 2 to 8 μm, and still more preferably 3 to 6 μm. The curable organosilicon compound is not particularly limited as long as it is an organosilicon compound having a molecular structure in which compound molecules can be cured by a curing reaction. Further, in the curing reaction, it is preferable that some kind of curing catalyst is involved as necessary, and among them, those that can be cured by the involvement of a germanium catalyst described later are preferable.

[0008] The curable organosilicon compound is at least one selected from the group consisting of a silane compound (S) represented by the following general formula (1), a hydrolyzate thereof and a polycondensate thereof. It is more preferable to have water repellency and water absorption prevention properties, and to combine with various materials, especially inorganic materials, or to hydrolyze and polycondensate by itself to form a water repellent layer or a water absorption preventing layer on the material. You can do it. _{^{R 4 p Si (OR 5)}} 4-p (1) ( provided that, R ⁴ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, R ⁵
Is an alkyl group having 1 to 6 carbon atoms, and p is 1 or 2. In the above general formula (1), R ⁴ is a group exhibiting water repellency and water absorption preventing property, and is not particularly limited as long as it is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and is, for example, a saturated alkyl group, an aryl group, or an aralkyl group. At least one selected from the group consisting of groups is preferable, and these groups having 4 to 18 carbon atoms are even more preferable in that water repellency, anti-water absorption property and durability thereof can be remarkably improved. Among them, a saturated alkyl group having 4 to 18 carbon atoms is most preferable in terms of excellent durability. R
^{When 4} is plural, plural R ⁴ may be the same or different.

Specific examples of R ⁴ include, but are not particularly limited to, methyl, ethyl, n-propyl,
Saturated alkyl groups such as isopropyl group, n-butyl group, isobutyl group, hexyl group, octyl group, decyl group, dodecyl group, hexadecyl group and octadecyl group; aryl groups such as phenyl group and naphthyl group, and aralkyl groups such as benzyl group An alkenyl group such as a vinyl group, a hexenyl group, and an octenyl group; In the general formula (1), R ⁵ is a group capable of bonding to various materials, particularly an inorganic material, or hydrolyzing / polycondensing by itself, and particularly a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. There is no limitation, and as the alkyl group having 1 to 6 carbon atoms, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-
Preferred examples include a butyl group, an isobutyl group, a pentyl group, and a hexyl group. Among them, a methyl group or an ethyl group is preferred in terms of high hydrolysis / polycondensability, and an ethyl group is most preferred. Since the hydrolysis / polycondensability of a methyl group is too high, the water absorption inhibitor of the present invention may thicken or gel over time, which may impair storage (storage) stability. Further, a plurality of R ⁵ may be the same or different. p is 1 or 2;
It is preferable that p is 1 in that it can contain many polycondensable functional groups.

Specific examples of the silane compound (S) include, but are not limited to, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriethoxysilane. Propoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltripropoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, hexyltri Methoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, octyltripropoxysilane,
Decyltrimethoxysilane, dodecyltrimethoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, hexadecyltrimethoxysilane,
Hexadecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, benzyltrimethoxysilane, benzyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dibutyldimethoxysilane, phenyl Methyldimethoxysilane, diphenyldimethoxysilane, diphenylsilanediol, vinyltrimethoxysilane,
Hexenyltrimethoxysilane, octenyltrimethoxysilane and the like are preferred. These silane compounds (S) may be used alone or in combination of two or more.

In the above general formula (1), R ⁴ is at least one selected from the group consisting of a saturated alkyl group having 4 to 18 carbon atoms, an aryl group and an aralkyl group; R ⁵ is a methyl group or an ethyl group; A trialkoxysilane compound in which p is 1 is preferred. In particular, in the general formula (1), a trialkoxysilane compound in which R ⁴ is a saturated alkyl group having 4 to 18 carbon atoms, R ⁵ is an ethyl group, and p is 1 is more preferable, and R ⁴ has 3 to 18 carbon atoms. 10 alkyltrialkoxysilane compounds are even more preferred. Specifically, for example, hexyltriethoxysilane and octyltriethoxysilane are preferably exemplified. The reason for this is that since it can contain a large number of hydrolyzable / polycondensable functional groups, it becomes a water-absorbing agent exhibiting excellent effects on water repellency, water-absorbing resistance, weather resistance and durability.

The hydrolyzate of the silane compound (S) and its polycondensate can be obtained by subjecting the silane compound (S) to hydrolysis and polycondensation by a conventionally known method. For example, the reaction is performed without a solvent or in an organic solvent capable of dissolving the silane compound (S) and water. Preferred examples of the organic solvent include alcohols, ketones, ethers, and cellolobs. Silane compound (S)
The amount of water is not particularly limited, but if the amount of water is too large, the resulting polycondensate becomes a high molecular weight substance, and thus the permeability of the water absorption inhibitor according to the present invention may decrease.
In the polycondensation, a conventionally known acid catalyst or base catalyst may be used.

The number average molecular weight of the organosilicon compound is not particularly limited, but is 5,000 or less, more preferably 2,000 or less, and even more preferably 10 or less.
00 or less. If the ratio is out of the above range, the permeability to the substrate or the like may be deteriorated, which is not preferable. The content ratio of the organosilicon compound is not particularly limited, for example, without adversely affecting the permeability to the substrate, sufficient water repellency, water absorption prevention, salt barrier and the like. From the viewpoint of application, it is preferable that the amount is 0.5 to 65% by weight, more preferably 1 to 45% by weight, still more preferably 3 to 30% by weight, based on the entire aqueous emulsion (a). Most preferably, it is 5 to 20% by weight.

The dispersion medium in the aqueous emulsion (a) is an aqueous medium, and the content ratio of water (water) in the aqueous emulsion (a) is not particularly limited. a) The water-absorbing agent of the present invention may be flammable or flammable, meaning that it is water-based. If it is too large, the amount of the organosilicon compound is reduced, and the water-repellent, water-absorbing, salt-insulating properties and Since their durability may be reduced, the amount is preferably 35 to 99% by weight, more preferably 55 to 85% by weight, and still more preferably 70 to 80% by weight, based on the whole aqueous emulsion (a).

The surface tension of the aqueous emulsion (a) is 40
It is preferably less than dyne / cm, more preferably 37 dyne / cm or less, still more preferably 3 dyne / cm or less.
5 dyne / cm or less. Aqueous emulsion (a)
If the surface tension is within the above range, the wettability with the substrate is improved, and the permeability is increased. The aqueous emulsion (a) is not particularly limited, but includes alkylene glycol monoalkyl such as monoalkylene glycol monoalkyl ether, dialkylene glycol monoalkyl ether, trialkylene glycol monoalkyl ether, and tetraalkylene glycol monoalkyl ether. At least one compound (A) selected from the group consisting of ethers and monoacetates thereof
Is further contained in the aqueous emulsion (a).
Is preferable in that the surface tension of the resin is reduced. That is, the compound (A) is preferable because it can play a role of reducing the surface tension in the aqueous emulsion (a). However, in obtaining the aqueous emulsion (a), the reduction of the surface tension is not necessarily required. In short, the surface tension may be less than 40 dyne / cm, but even if the surface tension needs to be reduced, The reduction method is not limited to the addition of the compound (A) described above.

As the alkylene group in the compound (A),
Although not particularly limited, examples thereof include an alkylene group having 2 to 4 carbon atoms. The alkyl group in the compound (A) is not particularly limited.
Alkyl group. In addition, monoacetates of alkylene glycol monoalkyl ethers, which are examples of compound (A), are compounds in which one hydroxyl group (—OH) of alkylene glycol monoalkyl ethers is substituted with an acetate group (—OCOCH ₃ ). It is. The monoalkylene glycol monoalkyl ether which is an example of the compound (A) is not particularly limited. For example, ethylene glycol such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, etc. Monoalkyl ethers; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether; butylene glycol monomethyl ether, butylene glycol monoethyl ether, butylene glycol monopropyl ether; Butylene glycol monobutyl ether, etc. Butylene glycol monoalkyl ether, and the like preferably.

The dialkylene glycol monoalkyl ether, which is an example of the compound (A), is not particularly limited. For example, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,
Diethylene glycol monoalkyl ethers such as diethylene glycol monopropyl ether and diethylene glycol monobutyl ether; dipropylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether and dipropylene glycol monobutyl ether; Preferred are dibutylene glycol monoalkyl ethers such as butylene glycol monomethyl ether, dibutylene glycol monoethyl ether, dibutylene glycol monopropyl ether, and dibutylene glycol monobutyl ether.

The trialkylene glycol monoalkyl ether, which is an example of the compound (A), is not particularly limited. Examples thereof include triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether,
Triethylene glycol monoalkyl ethers such as triethylene glycol monobutyl ether; tripropylene glycol monoalkyl ethers such as tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, and tripropylene glycol monobutyl ether; tributylene Preferred are tributylene glycol monoalkyl ethers such as glycol monomethyl ether, tributylene glycol monoethyl ether, tributylene glycol monopropyl ether, and tributylene glycol monobutyl ether.

The tetraalkylene glycol monoalkyl ether which is an example of the compound (A) is not particularly limited. For example, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monopropyl ether, tetraethylene glycol Tetraethylene glycol monoalkyl ether such as glycol monobutyl ether;
Tetrapropylene glycol monoalkyl ethers such as tetrapropylene glycol monomethyl ether, tetrapropylene glycol monoethyl ether, tetrapropylene glycol monopropyl ether, and tetrapropylene glycol monobutyl ether; tetrabutylene glycol monomethyl ether, tetrabutylene glycol monoethyl ether, tetrabutylene glycol Preferred are tetrabutylene glycol monoalkyl ethers such as monopropyl ether and tetrabutylene glycol monobutyl ether.

The content ratio of the compound (A) in the aqueous emulsion (a) is not particularly limited. For example, if the content is too large, the aqueous emulsion (a) and thus the water-absorbing agent of the present invention may have flammability and flammability. May have
If the amount is too small, the effect of lowering the surface tension is reduced. For example, 0% by weight of the aqueous emulsion (a) is used.
And more preferably not more than 10% by weight, more preferably 0.1 to 9% by weight, even more preferably 0.5 to 9% by weight.
７7% by weight, most preferably 1-5% by weight. In the aqueous emulsion (a), it is not particularly limited, but further contains an emulsifier, after coating,
It is preferable in that the permeability to the substrate is further improved.
An emulsifier is also contained in a conventionally known water-based water absorption inhibitor, and the emulsifier has an effect of reducing the surface tension. However, the surface tension is 40 dyne / cm or more. The agent could not penetrate deep into the substrate, and had a problem in durability. Further, as the amount of the emulsifier used is increased, the surface tension is reduced.
It is difficult to make it less than yne / cm, and when a large amount of an emulsifier is used, the water repellency, the water absorption prevention property, the salt barrier property, and the like deteriorate.

The emulsifier contained in the aqueous emulsion (a) is not particularly limited. For example, a normal emulsifier such as a nonionic emulsifier, an ionic emulsifier, and an amphoteric emulsifier can be preferably used. Specific examples of the nonionic emulsifier include, but are not particularly limited to, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters , Glycerin fatty acid esters, polyoxyethylene fatty acid esters, dimethylsiloxane copolymers in which the side chains and terminals of dimethylsiloxane are modified with polyalkylene oxide,
Preferable examples include celluloses.

The ionic emulsifier is usually classified into two types, anionic emulsifier and cationic emulsifier. Specific examples of the anionic emulsifier include, but are not particularly limited to, alkylbenzene sulfonates, higher alcohol sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylphenyl ether sulfates, and alkyl naphthyl salts. Are preferred. Specific examples of the cationic emulsifier include, but are not particularly limited to, alkylamine salts and quaternary ammonium salts.

Specific examples of the amphoteric emulsifier include, but are not particularly limited to, alkyl betaines and the like. One type of emulsifier may be used alone, or two or more types may be appropriately used in combination. Although the content ratio of the emulsifier is not particularly limited, for example, if it is too large, various properties such as water repellency, water absorption preventing properties, and salt barrier properties may be reduced. If it is too small, the emulsion stability of the aqueous emulsion (a) may be reduced. Is preferably 0.01 to 5% by weight, more preferably 0.05 to 3% by weight, and still more preferably 0.1 to 5% by weight based on the weight of the organosilicon compound.
1-2% by weight, most preferably 0.2-1% by weight.

The pH of the aqueous emulsion (a) is not particularly limited, but is preferably, for example, 3 to 12, since the stability with time is excellent, and more preferably, 4 to 12.
-10, and even more preferably 5-9. In the aqueous emulsion (a), although not particularly limited, if necessary, a conventionally known pH buffer, pH
Adjusters, silica sols, alumina sols, ceria sols, ultraviolet absorbers, water-soluble polymers and organic emulsion polymers can be preferably added. Further, in the aqueous emulsion (a), additives such as a fungicide, an algicide and a termite can be preferably mixed, although not particularly limited.

As a method for obtaining the aqueous emulsion (a), a general method of mixing or emulsifying is preferably used, and is not particularly limited. For example, the organic silicon compound and the compound (A) such as alkylene glycol monoalkyl ethers and the emulsifier used as necessary are separately or mixed while stirring at a high speed with a stirrer, a homomixer, an ultra disperser, a high-pressure homogenizer, or the like. The resulting liquid is added little by little to water, or the organosilicon compound is added little by little to a mixture of the compound (A) such as alkylene glycol monoalkyl ethers or emulsifier and water, or vice versa. An aqueous emulsion (a) of the present invention is obtained.

[Germanium Catalyst] The water absorption inhibitor according to the present invention is characterized in that the aqueous emulsion (a) is further combined with a germanium catalyst as a curing catalyst. The germanium catalyst referred to in the present invention is a step in which the curable organosilicon compound is cured after applying the water-absorbing inhibitor according to the present invention to a target substrate,
What is necessary is just to function as a curing catalyst, and there is no particular limitation on the type and shape of the compound. However, among these, as the germanium catalyst, an aqueous emulsion (b1) containing a dispersion containing a germanium compound, and an aqueous germanium compound solution (b2)
And at least one selected from the group consisting of a germanium compound powder (b3) and germanium in consideration of the storage stability of the water-absorbing inhibitor of the present invention and the pot life after coating. Aqueous emulsion (b1) containing a dispersion containing the compound is most preferred.

Aqueous emulsion (b1) containing a dispersion containing a germanium compound (hereinafter referred to as aqueous emulsion (b
The form of the dispersion containing the germanium compound in 1)) is preferably the same as the dispersion in the aqueous emulsion (a). In other words, micelle-like microparticles in which molecules of a germanium compound are aggregated and emulsified in an aqueous medium, or a solution obtained by dissolving a germanium compound in an organic solvent becomes finer as droplets (oil droplets). Preferred examples include fine particles, but the present invention is not particularly limited thereto. Further, the particle size of the dispersion containing the germanium compound is also preferably 1 to 10 μm, more preferably 1 to 8 μm, and still more preferably 2 to 6 μm, similarly to the dispersion in the aqueous emulsion (a).
m.

The dispersion medium in the aqueous emulsion (b1) is an aqueous medium, and the content ratio of water (water) in the aqueous emulsion (b1) is not particularly limited. In some cases, it is not formed, and when the amount is too large, the active ingredient as a catalyst may be insufficient. Therefore, it is preferably 40 to 99% by weight, more preferably 70% by weight, based on the aqueous emulsion (b1).
-97% by weight, even more preferably 85-95% by weight
It is. The emulsifier contained in the aqueous emulsion (b1) is not particularly limited. For example, a normal emulsifier such as a nonionic emulsifier, an ionic emulsifier, and an amphoteric emulsifier can be preferably used. The description is preferably the same as the content described in the item of the aqueous emulsion (a). One of these emulsifiers may be used alone, or two or more thereof may be appropriately used in combination.

The content ratio of the emulsifier is not particularly limited. For example, if it is too large, various properties such as water repellency, water absorption preventing property and salt barrier property may be deteriorated, and if it is too small, the content of the aqueous emulsion (b1) may be reduced. Since the emulsion stability may be low, the content is preferably 1 to 50% by weight, more preferably 5 to 30% by weight, based on the germanium compound.
Even more preferably, it is 10 to 25% by weight. Although the pH of the aqueous emulsion (b1) is not particularly limited, for example, a pH of 3 to 12 is preferable because the stability with time is excellent, and a pH of 4 to 10 is more preferable.
It is even more preferably 5 to 9.

Further, in the aqueous emulsion (b1),
Although not particularly limited, if necessary, conventionally known pH buffers, pH adjusters, silica sols, alumina sols, ceria sols, ultraviolet absorbers, water-soluble polymers and organic emulsion polymers are preferably added. Can be.
Further, in the aqueous emulsion (b1), although not particularly limited, additives such as a fungicide, an antialgal agent and a termite can be preferably mixed. As a method for obtaining the aqueous emulsion (b1), a general mixing or emulsifying method is preferably used, and is not particularly limited. For example, stirrer, homomixer,
While stirring at a high speed with an ultra disperser and a high-pressure homogenizer, a liquid obtained by separately or mixing a germanium compound and an emulsifier is added little by little to water, or a compound (A) such as an alkylene glycol monoalkyl ether or an emulsifier and water are added. The aqueous emulsion (b1) is obtained by adding the germanium compound little by little to the mixed solution or by performing the reverse of the above.

As the germanium compound aqueous solution (b2), it is preferable to use a water-soluble germanium compound having solubility in an aqueous medium. As a usage form, a form in which the water-soluble germanium compound is dissolved in the aqueous emulsion (a) (it may be dissolved at the time of use), or an aqueous solution in which the germanium compound is dissolved in an aqueous medium is used as an aqueous emulsion ( Preferred is a form in which the water-soluble germanium compound is dissolved in the water-absorbing agent when the water-absorbing agent of the present invention is used. Any form may be used, and there is no particular limitation.

The germanium compound powder (b3) is preferably used by mixing and suspending a germanium compound powder in which a germanium compound having no solubility in an aqueous medium is formed into fine particles. The form of use is preferably a form in which the above-mentioned germanium compound powder is mixed and suspended in the aqueous emulsion (a) (the form may be used as long as it is dissolved at the time of use), and is not particularly limited. The particle diameter of the germanium compound powder is not particularly limited as long as the germanium compound powder can be stably suspended in the aqueous emulsion (a). The germanium compound that can be used as the germanium catalyst in the present invention is not particularly limited, but specifically, tetramethoxygermanium, tetraethoxygermanium, tetra-i-propoxygermanium, tetra-n-propoxygermanium , Germanium alkoxides such as tetra-i-butoxygermanium, tetra-n-butoxygermanium, tetra-sec-butoxygermanium and tetra-t-butoxygermanium; germanium monosulfide, germanium disulfide, germanium monoselenide, diselenide Inorganic germanium compounds such as germanium, germanium monotelluride and germanium ditelluride; germanium halides such as germanium tetrabromide and germanium tetraiodide are preferred. There may be mentioned, among others, it is preferable to use the germanium alkoxides in an aqueous emulsion (b1), the inorganic germanium compounds are preferable as the germanium compound powder (b3). These may be used alone or in combination of two or more.

The amount of the germanium compound used in the aqueous emulsion (b1), the aqueous solution of the germanium compound (b2) and the powder of the germanium compound (b3), and finally the amount of the germanium catalyst used in the present invention, is determined by the amount of the water-absorbing inhibitor. When used for coating or the like, the total amount of the curable organosilicon compound in the water-absorbing inhibitor is 0.01 to 1%.
0% by weight, more preferably 0.1% by weight.
-5% by weight, even more preferably 0.5-1.5% by weight. When the use amount is less than 0.01% by weight, a sufficient catalytic effect may not be obtained in some cases, and it is not preferable. is there.

[Water-absorbing agent] The substrate on which the water-absorbing agent according to the present invention is used is not particularly limited. For example, exposed concrete, precast concrete, lightweight cellular concrete (ALC), lightweight concrete, Cement board, extruded cement board, asbestos cement board, pulp cement board, wool cement board, glass fiber cement board, carbon fiber cement board, mortar, joint mortar, gypsum board, gypsum plaster, dolomite plaster, hard board, silica Calcium plate,
Plaster, blocks, bricks, tiles, tiles, slate,
Natural stones, artificial stones, glass wool, rock wool, ceramic fibers, other than civil engineering and building materials such as wood and plywood, paper materials, cloth materials and the like can also be preferably mentioned,
Since the water absorption preventing agent of the present invention is obtained by combining a germanium catalyst as a curing catalyst, the crosslinking reaction is not limited to the pH of the substrate or the like, and is preferably a neutral substrate. Can be given as

The method of using the water-absorbing agent of the present invention on the above-mentioned substrate and the like is not particularly limited. For example, the water-absorbing inhibitor may be applied to the above-mentioned material by using a roller, a brush, a spray, or the like. It is preferable to impregnate or immerse the above materials. At this time (when used), the amount of the organosilicon compound is preferably 0.5 to 65% by weight, more preferably 1 to 45% by weight, still more preferably 3 to 30% by weight, based on the whole water-absorbing inhibitor. Most preferably, it is used after being diluted with water so as to be in the range of 5 to 20% by weight. If the amount of the organosilicon compound is too small, it is necessary to increase the number of times of application, impregnation or immersion. If the amount is too large, the permeability to the material tends to be poor.

[0036]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In the following, “parts by weight” may be simply referred to as “parts” for convenience. “%” Indicates “% by weight” unless otherwise specified. -Production Example 1-A solution prepared by dissolving 0.01 part of sodium hydroxide and 0.36 part of ammonium polyoxyethylene phenyl ether sulfate in 799 parts of water was stirred with a homomixer at a high speed, and hexyltriethoxy was added to the solution. A solution obtained by dissolving 0.3 part of polyoxyethylenediethoxymethylsilylpropylglycidyl nonyl phenyl ether and 0.3 part of sorbitan monolaurate in 200 parts of silane was gradually added, mixed and emulsified. The high-speed stirring was continued for 30 minutes to obtain an aqueous emulsion (A) containing a dispersion having a particle size of 4.1 μm.

Production Example 2 A solution prepared by dissolving polyoxyethylene lauryl ether in 0.8 part of tetrabutoxy-n-germanium was gradually added and mixed with 384 parts of water at a high speed with a homomixer. Emulsification was performed. The high-speed stirring was continued for 30 minutes to obtain an aqueous emulsion (B) containing a dispersion having a particle diameter of 2.3 μm. -Example 1-400 parts of the aqueous emulsion (A) was added with tetrabutoxy-
The aqueous emulsion of Example 1 (hereinafter, referred to as aqueous emulsion (1)) was obtained by dispersing n-germanium.

Example 2 Instead of dissolving tetrabutoxy-n-germanium in Example 1, the aqueous emulsion (B) was mixed, and the aqueous emulsion of Example 2 (hereinafter referred to as aqueous emulsion (2)) ) Got. Comparative Example 1 In Example 1, only the aqueous emulsion (A) was used as the aqueous emulsion of Comparative Example 1 (hereinafter, referred to as comparative aqueous emulsion (1)) without dissolving tetrabutoxy-n-germanium. The aqueous emulsion (1),
With respect to each of the water-based emulsion (2) and the comparative water-based emulsion (1), a water absorption prevention test on wood was performed by the following method. Table 1 shows the results.

(Water Absorption Prevention Test on Wood) For each of the above-mentioned aqueous emulsion (1), aqueous emulsion (2) and comparative aqueous emulsion (1), two types of oak wood and cedar wood were used as test wood. Is dried at 80 ° C. for 3 hours. The weight of each piece of wood after drying is referred to as a dry weight before treatment W ₀ . Each of the aqueous emulsion (1), the aqueous emulsion (2) and the comparative aqueous emulsion (1)
Both woods are soaked for 24 hours. After immersion, each wood is dried at 80 ° C. for 24 hours. The weight of each timber after drying after the immersion, the processed dry weight W _1.

Each wood dried after immersion is immersed in deionized water for 24 hours. The weight of each piece of wood after immersion is referred to as a weight W ₂ after water absorption. The same wood, which has not been subjected to the water absorption prevention treatment and has not been treated, is treated in the same manner as described above, and the weight after water absorption is reduced to W.
_{Assume 3} . The ratio (water absorption ratio) of the water absorption weight of the treated wood to the water absorption weight of the wood not subjected to the water absorption prevention treatment was calculated. Water absorption ratio = (W ₂ −W ₁ ) / (W ₃ −W ₀ )

[0041]

[Table 1]

Each of the aqueous emulsion (1), the aqueous emulsion (2) and the comparative aqueous emulsion (1) was evaluated for wettability and writability as a performance test on paper materials by the following methods. Table 2 shows the results.
Shown in (Performance Test on Paper Material) For each of the above-mentioned aqueous emulsion (1), aqueous emulsion (2) and comparative aqueous emulsion (1), high-quality paper is used as a performance test paper material, and immersed for 1 minute. The high quality paper after immersion is dried at 160 ° C. for 10 minutes.

Water drops are dropped on the high-quality paper after the drying, and the "wetting property" with respect to the paper is observed. ：: The paper does not get wet if water droplets are wiped off within 15 seconds. Δ: Paper is not wet if water droplets are wiped off immediately. ×: Wet as soon as water drops are dropped on the treated surface. Write on the quality paper after drying with water-based ink,
Observe the degree of bleeding as "writability". ○: No bleed ×: Bleed

[0044]

[Table 2]

The water repellency of each of the aqueous emulsion (1), the aqueous emulsion (2) and the comparative aqueous emulsion (1) was evaluated by the following method as the water absorption preventing property to the cloth material. Table 3 shows the results. (Water Absorption Prevention Test for Cloth Material) For each of the above-mentioned aqueous emulsion (1), aqueous emulsion (2) and comparative aqueous emulsion (1), as a test cloth material, "water repellency is reduced and water is easily permeated. Umbrella (made of nylon) 10cm
Prepare 10 cm and soak for 1 minute.

The immersed fabric is dried at 100 ° C. for 30 minutes. Sprinkle water on the dried fabric and observe the degree of water repellency as "water repellency". ：: repels water drops. ×: Water does not repel, the fabric gets wet and water spreads to the back.

[0047]

[Table 3]

[0048]

According to the present invention, the target substrate is not limited. For example, even in the case of a neutral substrate, excellent effects can be obtained with respect to prevention of water absorption and permeability and improvement of weather resistance. It is possible to provide a novel water-absorbing agent which has no toxicity, is excellent in handling safety, and has no adverse effect on the environment.

Continued on the front page F term (reference) 4J038 DL031 HA066 HA086 HA346 JA23 KA04 KA20 MA08 MA10 NA03 NA04 NA07 NA08 PB02 PB05 PC01 PC06 PC10

Claims (4)

[Claims] An anti-water absorption agent comprising a combination of an aqueous emulsion containing a dispersion containing a curable organosilicon compound and a germanium catalyst. 2. The curable organosilicon compound is at least one selected from the group consisting of a silane compound (S) represented by the following general formula (1), a hydrolyzate thereof and a polycondensate thereof. The water absorption inhibitor according to claim 1. _{^{R 4 p Si (OR 5)}} 4-p (1) ( provided that, R ⁴ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, R ⁵
Is an alkyl group having 1 to 6 carbon atoms, and p is 1 or 2. ) 3. The germanium catalyst according to claim 1, wherein the germanium catalyst is at least one selected from the group consisting of an aqueous emulsion containing a dispersion containing a germanium compound, a germanium compound aqueous solution, and a germanium compound powder. Water absorption inhibitor. 4. The water absorption inhibitor according to claim 1, wherein the dispersion has a particle size of 1 to 10 μm.