JPH04114979A - Aqueous organosilicon composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having improved dispersion stability and stability of performance as a material for preventing the permeation and water-absorption of a building or construction material by emulsifying an alkylalkoxysilane in water in the presence of an anionic and nonionic emulsifiers under specific pH condition. CONSTITUTION:The subject composition is produced by mixing (A) an alkylalkoxysilane (e.g. n-octyltriethoxysilane) and (B) 0.1-5wt.% (based on the component A) of an emulsifier produced by compounding (a) 0.01-20wt.% of an anionic emulsifier (e.g. sodium laurylsulfate) and (b) a nonionic emulsifier (e.g. polyoxyethylene stearyl ether) and incorporating the obtained mixture with (C) water containing an alkaline compound such as NaOH or amine dissolved therein in an amount to get an emulsion of pH7-10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an aqueous organosilicon composition useful as a permeable water absorption prevention material for concrete. For more details,
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 within a pH range of 7 to 10.

(Prior Art) It has been widely known that alkylalkoxysilanes are useful as water repellents for construction and civil engineering materials such as concrete. - For boat fishing, these alkoxysilanes diluted with various solvents were used. 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, its rapid evaporation rate limits its penetration into the substrate. On the other hand, if a solvent that does not easily evaporate is used, the coated surface becomes wet and difficult to dry. - Solvent-based coatings for boat fishing had problems such as not being able to coat wet concrete surfaces.

In order to solve the above problems and use alkyl alkoxysilane as a permeable water absorption prevention material 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, HLB has been developed as a means to solve these problems.
A method of aqueous emulsifying a hydrolyzable organosilicon compound such as an alkyltrialkoxysilane within the pH range of 6 to 8 using a nonionic emulsifier of
369. JP-A-1-292089) was reported. However, a nonionic emulsifier alone tends to cause two-layer separation, making it impossible to easily obtain a stable aqueous emulsion. HL of nonionic emulsifier by emulsifying silane
It is difficult to select optimal conditions such as B value, amount of emulsifier, emulsification method, etc.

Furthermore, when considering the balance between waterproofness and stability, permeability, etc., the emulsifiers that can be used 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.

In addition, considering the ability to prevent water absorption after application to architectural and civil engineering substrates such as concrete, the amount of emulsifier must be minimized as much as possible, but these methods have a limit to reducing the amount of emulsifier, and it is difficult to use solvent-based dishes. It is difficult to obtain water absorption prevention properties.

[Structure of the invention]

(Means for Solving the Problems) The present invention has been developed through extensive research to solve the above-mentioned problems.
As a result of the electrolysis, the alkyl alkoxysilane was purified using a nonionic emulsifier and an anionic emulsifier (the proportion of the anionic emulsifier in the total emulsifier was 0.01 to 20% by weight).
The aqueous organosilicon composition obtained by aqueous emulsification within the range of H7 to 10 not only has excellent performance stability as a permeable water absorption prevention material for architectural and civil engineering substrates, but also has a stable appearance without separating. Moreover, since it is not necessary to carefully select various conditions during emulsification, it can be easily produced.

The alkylalkoxysilane used in the present invention is not particularly limited, but 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, but it is preferable. is an ethoxy group, and more preferably a monoalkyltrialkoxysilane. Examples of alkylalkoxysilanes include hexyltriethoxysilane, heptyltriethoxysilane, octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, undecyltriethoxysilane, dodecyltriethoxysilane, and tridecyltriethoxysilane. , tetradecyltriethoxysilane, pentadecyltriethoxysilane, hexadecyltriethoxysilane, heptadecyltriethoxysilane, octadecyltriethoxysilane, nonadecyltriethoxysilane, eicosyltriethoxysilane, octadecylmethyljethoxysilane,
or a mixture thereof. Furthermore, fluoroalkylalkoxysilanes such as heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, and l-lifluoropropyltrimethoxysilane can also be used alone or in a mixture with others.

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 penetrating 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 are not very desirable because their reactivity with silanol and the like on the surface of the substrate is somewhat reduced.

In addition, as a method of reducing costs, these alkyl alkoxysilanes may be used without purification by hydrosilylating the corresponding α-olefin with hydroalkoxysilane. 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, hendyl peroxide, di-t-butyl peroxide, and perbenzoic acid. Examples include L-butyl, but in view of safety, reaction efficiency, economic efficiency, reaction conditions, etc., a method using chloroplatinic acid, which is widely used industrially, is preferable. The amount of catalyst is 1. For example, when using chloroplatinic acid, the reaction can be carried out in any amount, but it is better to keep it as small as possible from both economical and hygienic standpoints. 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 monobalminate, sorbitan monostearate, sorbitan tristearate 5 Sorbitan monooleate Sorbitan trioleate. Sorbitan monosesquioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbicun tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitol tetraoleate, polyoxyethylene lauryl ether.

Polyoxyethylene cetyl ether 5 polyoxyethylene stearyl ether polyoxyethylene oleyl ether, polyoxyethylene higher alcohol ether,
Examples include polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether.

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

As a silicone-based nonionic emulsifier, for example, the formula %formula% [R=furkyl or H.

Alternatively, polyalkylene-modified polydimethylsiloxane compounds represented by the formula %) :1 ] (]) (R=alkyl 11 or H, c, d, p: integer) may be mentioned.

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

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.

There are no particular restrictions on the anionic emulsifier to be used; for example,
Sodium lauryl sulfate, triethanolamine lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium alkylnafucrene sulfonate, sodium dialkyl sulfosuccinate, sodium alkyl diphenyl ether disulfonate, alkyl phosphate diethanolamine salt, alkyl phosphate potassium salt .

Polyoxyethylene lauryl ether sodium sulfate Uno 1
．． Polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether sulfate triethanolamine, polyoxoethylene alkyl phenyl ether sodium sulfate, alkanesulfonic acid 1-
mixed fatty acid soda soap, semi-hardened beef tallow fatty acid soda soap, semi-hardened beef tallow fatty acid potassium soap, stearic acid sodium soap, oleic acid potassium soap, castor oil potash soap, higher alcohol sodium sulfate beta-naphthalene sulfonate formalin condensate sodium Examples include salts, special aromatic sulfonic acid formalin condensates, special carboxylic acid type surfactants, and special polycarboxylic acid type polymer surfactants.

The proportion of anionic emulsifier in the total emulsifier is 1, preferably 0.
．． 1 to 5% by weight is desirable. If a nonionic emulsifier or anionic emulsifier is used alone, or if the concentration of the anionic emulsifier is less than 5% by weight of the total amount of emulsifier, it will be difficult to produce a stable emulsion, and the emulsification conditions will be limited. Ru.

The total amount of emulsifier V is preferably 0.1 to 50% by weight of the Plan 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%.

The pH after aqueousization is preferably 7-10. If rlH is out of the specified range, condensation is likely to occur. Special feature 4: When the pH is less than 7, hydrolysis is promoted and condensation is accelerated. Furthermore, if the pH exceeds [0], it becomes unstable and also causes operational problems.

There are no particular limitations on the method or order of pH adjustment, but it is desirable to perform it at an early stage of aqueous dispersion. p
The slower the H preparation, the more the hydrolysis may proceed. As the pH adjuster, an alkali that is generally used for adjusting pH may be used. For example, sodium hydroxide,
Examples include potassium hydroxide, calcium hydroxide, ammonia, and various amines.

A mixture of the above-mentioned alkyl alkoxysilane and the emulsifier group in a weight ratio of 0.1 to 5% by weight of nonionic emulsifier/anionic emulsifier to the silane component is 0.1/99°9 to 5/95. The desired aqueous organosilicon composition is obtained by adding dropwise water in which an alkali is dissolved so that the pH after emulsification is 7 to 10 while stirring at high speed. Even if the emulsifier group is not completely dissolved in the silane, if it is made uniform 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 form, or the liquid may become transparent at first, but as the amount of water increases, it becomes a uniform emulsion.

Silane (organosilicon 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. Furthermore, since subsequent coatings will reduce the permeability accordingly, emulsions containing a dilute silane component with a concentration of 1% by weight 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 effect on the penetration depth, but it is better to use it at less than 70% by weight in order to avoid uneven coating, slow penetration rate, etc., or from the economical point of view.

(Action 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 in dry areas and preventing deterioration of the base material. can be prevented and provide long-term durability. Furthermore, since the composition of the present invention is slightly alkaline with a pf-1 of 7 to 10, it can be used for 12 months or 50 days at room temperature despite the presence of alkoxy groups that are easily condensed by hydrolysis.
Even after storage for 3 months at °C, no thickening, no gelation, no decrease in performance as a water absorption inhibitor, etc. occur. Furthermore, in this composition, droplets of hydrophobic silane that have been made hydrophilic to some extent by a nonionic emulsifier are made more hydrophilic by a small amount of anionic emulsifier and stabilized in water, resulting in a stable emulsion that does not separate over a long period of time. Even if this is the case, re-emulsification is possible just by stirring lightly.

Thus, it has been found that the composition of the present invention is an aqueous organosilicon composition that is extremely useful in the field of construction and civil engineering.

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

Additives such as pigments or antifungal agents can be added.

Example 1 60 g of n-octyltriethoxysilane, 0.20 g of polyoxyethylene stearyl ether, and 0.01 g of sodium laurate were mixed and stirred at high speed at 11,000 rpm or higher, followed by adding 2 g of a 0.1% by weight aqueous sodium hydroxide solution. By gradually adding a mixture of 74 g of water, p.
A white aqueous emulsion of H9,3 was obtained. Even when this emulsion was applied to a mortar board after being left at 50°C for more than 6 months, it did not turn wet after drying.

Example 2 0.20g of polyoxyethylene stearyl ether and 0.20g of polyoxyethylene sorbitan trioleate
A white aqueous emulsion with a pH of 9.5 was obtained in the same manner as in Example 1 except that the 50% of this emulsion
Even when applied to a mortar board after being left at °C for more than 6 months, it did not turn wet after drying.

Example 3 0.20 g of polyoxyethylene stearyl ether 5
A white aqueous emulsion with a pH of 9.4 was obtained in the same manner as in Example 1 except that TLWET >7604 (silicone nonionic emulsifier manufactured by Nippon Unicar Co., Ltd.) was used in an amount of 0.20 g. Even when this emulsion was applied to a mortar board after being left at 50°C for more than 6 months, it did not turn wet after drying.

Example 4 0.20 g of polyoxyethylene stearyl ether was
A white aqueous emulsion with a pH of 9.7 was obtained in the same manner as in Example 1, except that 0.20 g of FTOP EF-121 (fluorine-based nonionic emulsifier manufactured by Shin-Akita Kasei Co., Ltd.) was used. Even when this emulsion was applied to a mortar board after being left at 50°C for more than 6 months, it did not turn wet after drying.

Comparative Example 1 60 g of n-octyltriethoxysilane, 0.20 g of polyoxyethylene stearyl ether, and 0.01 g of sodium laurate were mixed and stirred at high speed at 11,000 rpm or more, and 76 g of water was gradually added to the mixture.
A white aqueous emulsion of H3,8 was obtained. When this emulsion was left at 50°C for two months and then applied to a mortar board, it became a wet color after drying.

Comparative Example 2 0.20g of polyoxyethylene stearyl ether and 0.20g of polyoxyethylene sorbitan trioleate
A white aqueous emulsion with a pH of 4.1 was obtained in the same manner as in Comparative 1 except that 50° this emulsion
When C was applied to a mortar board after being left for two months, it became a wet color after drying.

Comparative Example 3 0.20g of polyoxyethylene stearyl ether 5
A white aqueous emulsion with a pH of 4.1 was obtained in the same manner as in Comparative Example 1 except that 0.20 g of ILWET L, -7604 (silicone nonionic emulsifier manufactured by Nippon Unicar Co., Ltd.) was used. This emulsion was heated at 50°C for 2
When applied to a mortar board after being left for several months, it became a wet color after drying.

Comparative Example 4 0.20g of polyoxyethylene stearyl ether was
A white aqueous emulsion with a pH of 4.5 was obtained in the same manner as in Comparative Example 1 except that 0.20 g of FTOP El-121 (fluorine-based nonionic emulsifier manufactured by Shin-Akita Kasei Co., Ltd.) was used. When this emulsion was left at 50°C for two months and then applied to a mortar board, it became a wet color after drying.

(Time until separation) Time until separation after storage at 50'C. Separation here refers to a state in which it does not re-emulsify even if it is lightly shaken. For example, even if the mixture is slightly separated into two layers, if it is gently shaken to emulsify it, it can be confirmed that it has not separated.

(50°C storage time until it no longer permeates into the mortar) When - is applied to the surface of the base mortar (JIS R5201), the 50°C storage time until the silane condenses progresses and no longer permeates into the base mortar. As the condensation of the silane progresses, a viscous substance remains on the surface of the base mold, giving it a wet color.

(Water absorption ratio) 300 g//m2 of the sample was applied to the entire surface of the base mortar of 4 cm x 4 cm x 8 cm, dried for 28 L-7, and then immersed in water for 7 days according to the method of JI-A1404. The daily water absorption ratio was determined.

Water absorption amount between 71” (8) Water absorption rate - ×100 Water absorption amount (g) of uncoated specimen for 7 days

Claims (1)

[Claims] 1. Aqueous emulsification within the pH range of 7 to 10 using an alkyl alkoxysilane, a nonionic emulsifier in which the proportion of the anionic emulsifier in the total emulsifier is 0.01 to 20% by weight, and an anionic emulsifier. An aqueous organosilicon composition characterized by: 2. The aqueous organosilicon composition according to claim 1, wherein an alkaline compound such as sodium hydroxide or amines is added to aqueous emulsify the alkyl alkoxysilane within a pH range of 7 to 10. 3. The aqueous organosilicon composition according to claim 1 or 2, wherein the nonionic emulsifier is polyalkylene oxide-modified polydimethylsiloxane. 4. The aqueous organosilicon composition according to claim 1 or 2, wherein the nonionic emulsifier is a fluorinated alkyl group-containing polyalkylene oxide. 5. Total amount of emulsifier is 0 relative to alkyl alkoxysilane
．． 5. The aqueous organosilicon composition according to claim 1, wherein the content is 1 to 5% by weight.