JPH03232527A - Aqueous organo-silicic composition - Google Patents

Abstract

PURPOSE:To render water resistance to a base material for civil engineering and construction by emulsifying an alkylalkoxysilane in water with a blend of a nonionic emulsifier with a specified percentage of an anionic emulsifier and applying the resulting aq. organo-silicic compsn. to the base material. CONSTITUTION:An alkylalkoxysilane is emulsified in water with a blend of a nonionic emulsifier with 0.01-20wt.% anionic emulsifier basing on the amt. of the blend to obtain an aq. organo-silicic compsn. At least one alkyl group directly bonded to silicon in the alkylalkoxysilane preferably has 6-20 carbon atoms. When the compsn. is applied to a base material for civil engineering and construction such as concrete, it penetrates deeply into the material, bonds to the material and forms a superior waterproof layer after drying.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an aqueous organosilicon composition useful as an aqueous penetrating water absorption inhibitor for concrete. More specifically, the present invention relates to an aqueous organosilicon composition characterized in that an alkyl alkoxysilane is aqueous emulsified using a nonionic emulsifier and an anionic emulsifier.

(Prior Art) It has been widely known that alkyl alkoxysilanes are useful as waterproofing agents for construction and civil engineering materials such as concrete.
It was known. Generally, these alkoxysilanes were diluted with various solvents. The scope of use of such solvent-based compositions is limited due to the toxicity, volatility, and flammability of the solvent used. for example,
When isopropyl alcohol, which has relatively low toxicity, is used as a solvent, there have been cases in which its rapid evaporation rate limits its penetration into the substrate. On the other hand, when a solvent that is difficult to volatilize is used, the coating surface becomes wet and difficult to dry, and solvent-based coatings generally have problems such as not being able to coat wet concrete surfaces.

In order to solve the above problems and use alkyl alkoxysilane as a penetrating water absorption inhibitor for concrete, it is ideal to make it into an aqueous solution or aqueous dispersion.
Alkoxysilanes are highly hydrolyzable and subsequent condensation reactions are likely to occur, so it has been considered extremely difficult to make them exist stably in water.

Recently, as a means to solve these problems, HLB 4
A method of aqueous emulsifying a hydrolyzable organosilicon compound such as an alkyltrialkoxysilane using 15 nonionic emulsifiers has been reported (Japanese Unexamined Patent Publication No. 197369/1983). However, a nonionic emulsifier alone tends to cause two-layer separation, making it impossible to easily obtain a stable aqueous emulsion. HLB value of nonionic emulsifier depending on emulsifying silane.

It is difficult to select optimal conditions such as the amount of emulsifier and emulsification method. Furthermore, when considering the balance between waterproofness and stability, permeability, etc., usable emulsifiers are limited.

For example, even if the emulsifier has the same HLB, there are problems in that the permeability into concrete etc. varies depending on whether it is solid or liquid.

[Structure of the invention]

(Means for Solving the Problems) As a result of intensive research in order to solve the above-mentioned problems, the present invention has been made by combining alkyl alkoxysilane with a nonionic emulsifier and an anionic emulsifier (the proportion of anionic emulsifier in the total emulsifier is The aqueous organosilicon composition obtained by aqueous emulsification using (0.01 to 20% by weight) not only has excellent performance stability as a penetrating water absorption inhibitor for building materials but also separates in appearance. The emulsification process is stable and easy to produce since there is no need to carefully select conditions for emulsification. Furthermore, surprisingly, it can be emulsified in a very small amount of less than 0.5% by weight based on the alkyl alkoxysilane.

The alkylalkoxysilane used in the present invention is not particularly limited, but it is preferable that at least one alkyl group directly bonded to silicon has 6 to 20 carbon atoms, and the alkoxy group may be a methoxy group, an ethoxy group, or a propoxy group. is an ethoxy group, and more preferably a monoalkyltrialkoxysilane. Examples of alkylalkoxysilanes include hexyltriethoxysilane, heptyltriethoxysilane, octyltriethoxysilane,
Nonyltriethoxysilane, decyltriethoxysilane, undecyltriethoxysilane, dodecyltriethoxysilane, tridecyltriethoxysilane, tetradecyltriethoxysilane, pentadecyltriethoxysilane, hexadecyltriethoxysilane, heptadecyltriethoxysilane , octadecyltriethoxysilane,
Examples include nonadecyltriethoxysilane, eicosyltriethoxysilane, octadecylmethyljethoxysilane, or mixtures thereof.

When the number of carbon atoms in at least one alkyl group directly bonded to silicon is less than 6, the hydrolyzability and volatility are very high, and a portion of the alkyl group reacts with the surface of the substrate immediately after coating, causing further aqueous composition. Not only does it delay penetration, but during that time unreacted silane components tend to evaporate, resulting in water repellency only being imparted to the surface of the substrate. Conversely, if the number of carbon atoms in at least one alkyl group directly bonded to silicon is greater than 20, the molecular weight will be too large, making it difficult to penetrate. In addition, when the alkoxy group is a methoxy group, it has poor stability under alkaline conditions, so bonding or crosslinking tends to occur on the surface before it penetrates into the inside of the base material. The better the stability, the slower it will bond to the base material even if it penetrates into the interior. Dialkyldialkoxysilanes and trialkylmonoalkoxysilanes other than monoalkyltrialkoxysilanes can be used in combination, although their reactivity with silanol and the like on the surface of the substrate is somewhat reduced.

In addition, these alkyl alkoxysilanes may be used without purification by hydrosilylating the corresponding α-olefin with hydroalkoxysilane as a method of reducing costs. As this catalyst, a transition metal catalyst or a radical initiator commonly used in the hydrosilylation reaction of olefins can be used. Transition metal catalysts include transition metal complexes or halides such as platinum, cobalt, rhodium, palladium, or nickel, and radical initiators include azobisisobutyronitrile, benzoyl peroxide, di-t-butyl peroxide, and nickel. Examples include t-butyl benzoate, but in view of safety 9 reaction efficiency, economic efficiency, reaction conditions, etc., a method using chloroplatinic acid, which is widely used industrially, is preferable. The amount of catalyst is 9. For example, if chloroplatinic acid is used, the reaction can be carried out in any amount, but it is better to minimize it from both economical and sanitary considerations. 0.1-5 mmol for silane
% chloroplatinic acid catalyst, hydrosilylation with a conversion rate of 98% or more can be performed by heating at 90°C for 5 hours. usually,
A solution of these catalysts dissolved in a solvent or the like is used. This reaction proceeds quantitatively and requires only a very small amount of catalyst.
Unless there is a problem with residual hydrosilane or catalyst toxicity, there is no need for purification.

The nonionic emulsifier to be used is not particularly limited, and examples include -
Glycerol monostearate and glycerol monooleate are popular nonionic emulsifiers.

Sorbitan monolaurate, sorbitan monopalminate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, sorbitan monosesquioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitol tetraoleate, polyoxyethylene lauryl ether.

Polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene higher alcohol ether,
Examples include polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether.

In addition to the one or more general nonionic emulsifiers mentioned above, fluorine-based or silicone-based nonionic emulsifiers can also be used.

Examples of silicone-based nonionic emulsifiers include formula % (For example, formula %) or CHs-5i[(Si-0)s(OCaH4). (OC
Examples thereof include polyalkylene-modified polydimethylsiloxane compounds represented by sHs)aOR] sH3R:forcenco)orH(n).

Examples of fluorine-based nonionic emulsifiers include fluorinated alkyl group-containing polyalkylene oxide compounds represented by the formula % ().

Any nonionic emulsifier listed above can be selected, but it is desirable to use a liquid nonionic emulsifier in order to produce an emulsion that is more stable and penetrates deeply into building materials such as concrete.

The anionic emulsifier to be used is not particularly limited;9 For example,
Sodium lauryl sulfate, triethanolamine lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium alkylnaphthalene sulfonate, sodium dialkyl sulfosuccinate, sodium alkyl diphenyl ether disulfonate, jetanolamine alkyl phosphate, alkyl phosphate Potassium salt.

Sodium polyoxyethylene lauryl ether sulfate,
Sodium polyoxyethylene alkyl ether sulfate,
Polyoxyethylene alkyl ether sulfate triethanolamine, polyoxyethylene alkyl phenyl ether sulfate sodium, alkanesulfonate sodium,
Mixed fatty acid soda soap, semi-hardened beef tallow fatty acid soda soap,
Semi-hardened beef tallow fatty acid potash soap, stearic acid soda soap,
Potassium oleate soap.

Castor oil potash soap, higher alcohol sodium sulfate.

Examples include sodium salts of β-naphthalenesulfonic acid formalin condensates, special aromatic sulfonic acid formalin condensates, special carboxylic acid type surfactants, and special polycarboxylic acid type polymeric surfactants.

The proportion of anionic emulsifier in the total emulsifier is preferably 0
．． 1 to 20% by weight is desirable. Use a nonionic emulsifier or an anionic emulsifier alone.

If the concentration of the anionic emulsifier is 5% by weight or more based on the total amount of emulsifier, it will be difficult to produce a stable emulsion, resulting in easy separation, and the emulsification conditions will also be limited.

The total amount of emulsifier is preferably 0.1 to 50% by weight of the silane component. If it is less than 0.1% by weight, a stable emulsion cannot be obtained and functional stability will deteriorate. If it is more than 50% by weight, sufficient water absorption prevention performance cannot be obtained. Desirably 0.1-5
Weight%.

A mixture of the above-mentioned alkyl alkoxysilanes and nonionic emulsifiers in a weight ratio of 0.1 to 50% by weight of nonionic emulsifier/anionic emulsifier to the silane component of 0.1/99°9 to 5/95. While stirring at high speed with a homomixer or the like, water is added dropwise little by little to obtain a dilute aqueous organosilicon composition. Even if the emulsifier group is not completely dissolved in the silane, if it is made homogeneous by stirring, a stable emulsion can be obtained after adding water.

Also, if you add water little by little, the concentration and viscosity may increase, insoluble matter may occur, or the liquid may become transparent, but as the amount of water increases, it becomes a uniform emulsion. .

Silane (organic silicon compound) of this aqueous organosilicon composition
The component concentration is preferably 1 to 70% by weight. If the weight is less than 1%, it is not possible to impart sufficient permeation and water absorption prevention performance to concrete with a single application. moreover.

Since the second and subsequent coatings will reduce the permeability accordingly, emulsions containing @thin silane components with a concentration of 1% or less are not suitable for this application. Moreover, if it exceeds 70% by weight, the viscosity becomes high and coating becomes difficult.

The viscosity has almost no influence on the penetration depth, but it is better to use it at 50% by weight or less in order to avoid uneven coating, slow penetration rate, etc., or from the economical point of view.

(Operation of the Invention) When the composition thus obtained is applied to a civil engineering and construction base material such as concrete, it penetrates deep into the interior and binds, forming an excellent waterproof layer after drying.

Deterioration of the base material can be prevented and long-term durability can be imparted. Furthermore, despite the presence of alkoxy groups that are easily condensed by hydrolysis, the composition of the present invention does not thicken, gel, or deteriorate in performance as a water absorption inhibitor even after being stored at room temperature for six months. Furthermore, this composition is a stable emulsion that does not separate over a long period of time because the droplets of hydrophobic silane, which have been made hydrophilic to some extent by a nonionic emulsifier, are further made hydrophilic by a small amount of anionic emulsification and stabilized in water. . Thus one composition of the present invention.

It was found that this is an extremely useful aqueous organosilicon composition in the field of construction and civil engineering.

The composition of the present invention further includes a dye, if necessary.

Additives such as pigments can be added.

Example 1 20 g of n-octyltriethoxysilane, 3.98 g of polyoxyethylene stearyl ether, and 0.02 g of sodium laurate were mixed, stirred at high speed at 11,000 rpm or more, and 76 g of water was gradually added to the mixture for 6 months at room temperature. A stable white aqueous emulsion was obtained.

Example 2 3.98 g of polyoxyethylene stearyl ether and 3.98 g of polyoxyethylene sorbitan trioleate
A white aqueous emulsion stable for more than six months at room temperature was obtained in the same manner as in Example 1 except that

Example 3 3.98 g of polyoxyethylene stearyl ether was added to 5
A white aqueous emulsion stable at room temperature for six months or more was obtained in the same manner as in Example 1 except that 3.98 g of ILWET L-7604 (silicone nonionic emulsifier manufactured by Nippon Unicar Co., Ltd.) was used.

Example 4 3.98 g of polyoxyethylene stearyl ether was
A white aqueous emulsion stable at room temperature for six months or more was obtained in the same manner as in Example 1 except that 3.98 g of FTOP EF-121 (fluorine-based nonionic emulsifier manufactured by Shin-Akita Kasei Co., Ltd.) was used.

Example 5 Octadecyltriethoxysilane 50g, hexyltrimethoxysilane 10g, polyoxyethylene stearyl ether 0.2g, sodium lauryl sulfate 0.0
4 g were mixed, stirred at high speed at 11,000 rpm or more, and 40 g of water was gradually added thereto to obtain a white aqueous emulsion that was stable for 6 months or more at room temperature.

Example 6 20 g of decyltrimethoxysilane, 7 g of polyoxyethylene nonylphenyl ether (HLB 3.5), polyoxyethylene nonylphenyl ether (HLB 13.5)
) and 0.02 g of sodium lauryl sulfate, stirred at high speed at 11,000 rpm or higher, and added 7 g of water.
By gradually adding 2 g, a white aqueous emulsion that was stable for more than 6 months at room temperature was obtained.

Comparative Example 1 20 g of n-octyltriethoxysilane and 4 g of polyoxyethylene stearyl ether were mixed and heated for 11,000 r.
A white aqueous emulsion was obtained by gradually adding 76 g of water to the emulsion with high speed stirring at a temperature above p, which separated into two layers within 24 hours at room temperature.

Comparative Example 2 20 g of n-octyltriethoxysilane, 3.60 g of polyoxyethylene stearyl ether, and 0.40 g of sodium lauryl sulfate were mixed, stirred at high speed at 11,000 rpm or more, and 76 g of water was gradually added to the mixture to form a white aqueous emulsion. However, it separated into two layers within 24 hours at room temperature.

Comparative Example 3 20 g of n-octyltriethoxysilane, 2. Polyoxyethylene stearyl ether. OOg and sodium lauryl sulfate2. A white aqueous emulsion was obtained by mixing OOg and gradually adding 76g of water to the mixture with high-speed stirring at 11,000 rpm or more, which separated into two layers within one hour at room temperature.

Comparative Example 4 20 g of n-octyltriethoxysilane and 4.00 g of sodium lauryl sulfate were mixed, stirred at high speed at 11,000 rpm or more, and 76 g of water was gradually added to make the mixture aqueous, but emulsification did not occur.

(Hereafter, blank space) [Water absorption rate] 4 cm x 4 cm x 8 cm base mortar (JIS R5201), air-dried, 4 months old, coating amount 3
00g/m" and air dry for 28 days to meet JIS
The water absorption rate after 7 days of water immersion was determined according to the method of A1404.

Water absorption (g)

Claims (1)

[Claims] 1. Aqueous emulsification of alkylalkoxysilane using a nonionic emulsifier and an anionic emulsifier in which the proportion of the anionic emulsifier in the total emulsifier is 0.01 to 20% by weight. An aqueous organosilicon composition. 2. The aqueous organosilicon composition according to claim 1, wherein the nonionic emulsifier is polyalkylene oxide-modified polydimethylsiloxane. 3. The aqueous organosilicon composition according to claim 1, wherein the nonionic emulsifier is a fluorinated alkyl group-containing polyalkylene oxide. 4. Total amount of emulsifier is 0 relative to alkyl alkoxysilane
．． The aqueous organosilicon composition according to any one of claims 1 to 3, wherein the content is 1 to 5% by weight.