JPH0686591B2 - Surface treatment agent - Google Patents

Description

TECHNICAL FIELD The present invention relates to a surface treating agent, and more specifically, it has permeability, and is excellent in waterproofness and moisture permeability. For example, concrete, mortar, fiber, wood, The present invention relates to a surface treatment agent that can be suitably used for surface treatment of metals and the like.

[Problems to be Solved by Prior Art and Invention] For example, in the fields of construction / civil engineering, textiles, steel, etc., surface treatment is performed for the purpose of imparting waterproofness to members or improving weather resistance of the members. Agents are used.

Particularly in the fields of construction and civil engineering, in recent years, the density of concrete is low, and water permeates into the concrete from the outside to cause deterioration of the concrete, which has become a social problem.

One of the reasons why dense concrete cannot be obtained is
This is because concrete structures with higher water content have been placed in order to improve fluidity, as the construction of concrete structures has become higher and construction methods such as pumping have been introduced.

Therefore, in order to obtain dense concrete, a water reducing agent or the like that can reduce the water content without impairing the fluidity has been developed, and some results have been achieved.

However, apart from this, recently, in order to block the water that permeates from the outside, which causes various troubles, it is possible to permeate the inside of the concrete by simply applying it to the surface of the concrete, and to impart waterproofness. Development of surface treatment agents is becoming active.

By the way, acrylic rubber-based waterproofing agents and epoxy-based waterproofing agents are generally known as coating-type waterproofing agents, which are one of those conventionally used for waterproofing of concrete outer walls. There are drawbacks such as a large amount of coating required to form a film, the texture of the substrate cannot be utilized, and the moisture permeability is insufficient to prevent dew condensation.

Further, since they are coating films, there is a problem that they are easily affected by ultraviolet rays and their weather resistance is not sufficient.

Therefore, a permeation type waterproofing agent, which is considered to be particularly advantageous for improving weather resistance, has been actively developed.

As the permeation type waterproofing agent, various types such as acrylic emulsion type, silicone type and silane type are commercially available.

However, each of these has advantages and disadvantages, and although it is possible to impart waterproofness, it does not have sufficient moisture permeability to prevent dew condensation.

Therefore, there is a demand for a surface treatment agent that has permeability, waterproofness, and moisture permeability.

The present invention has been made based on the above circumstances.

An object of the present invention is to provide a surface treatment agent which has permeability and is excellent in waterproofness and moisture permeability.

[Means for Solving the Problems] In order to solve the above problems, as a result of extensive studies by the present inventors, a specific surface treatment agent containing a specific silica sol has permeability and waterproofness, Excellent in moisture permeability,
For example, it can be suitably used as a surface treatment agent for members made of concrete, mortar, fibers, wood, etc. When used for surface treatment of concrete, mortar, etc., it can impart waterproofness without impairing air permeability of the skeleton. The present invention has been achieved by discovering that

The composition of the present invention comprises a surface treatment agent containing a hydrophobic silica sol obtained by treating the surface of the colloidal silica with a higher alcohol as an active ingredient so that the hydrophobicity of the colloidal silica is 1% or more. Is.

The hydrophobic silica sol is one in which hydrophobic colloidal silica obtained by substituting silanol groups on the surface of colloidal silica with organic hydrophobic groups is dispersed in an organic solvent.

Specifically, for example, the pH is adjusted to 1 to 2 by adding an acid to a colloidal silica aqueous solution, azeotropic dehydration is performed by adding a lower alcohol, and then a higher alcohol is added and heating and refluxing are performed to colloidal. It can be obtained by hydrophobizing silica, distilling off a lower alcohol by distillation, and then adding alcohol amine for neutralization.

The colloidal silica is not particularly limited, for example, those obtained by a method such as an acid decomposition electrolytic dialysis method using water glass, a peptization method, an ion exchange method, a hydrolysis method using ethyl silicate, etc. Can also be preferably used.

Examples of the lower alcohol include, but are not limited to, methanol, ethanol, propanol, butanol, and amino alcohol.

Examples of the higher alcohol include hexanol,
Heptanol, octanol, nonanol, capryl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol and the like can be mentioned.

Examples of the alcohol amine include N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dipropylethanolamine and the like.

The hydrophobizing rate of the colloidal silica [percentage of the ratio of organic hydrophobic groups (OR groups) to all OH groups on the surface of the colloidal silica] is usually 1% or more, preferably 3% or more, and more preferably 8% or more. . If the hydrophobicity is less than 1%, the waterproof property is not sufficient.

Preferable examples of the organic solvent in which the hydrophobized colloidal silica is dispersed include the higher alcohols. The higher alcohol may be used as it is for making the colloidal silica hydrophobic,
A different one from the one used for hydrophobizing the colloidal silica may be used, but if the one used for hydrophobizing the colloidal silica is used as it is, the preparation process of the hydrophobic silica sol can be simplified. it can.

The surface treating agent of the present invention is usually used by further diluting the above-mentioned hydrophobic silica sol stock solution with an appropriate solvent.

Examples of the solvent include water, alcohols such as methanol, ethanol, propanol, butanol, pentanol, heptanol, and octanol; hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, cyclohexane, ethylcyclohexane, and decalin;
Ethers such as diethyl ether, ethyl vinyl ether, butyl vinyl ether, anisole, dioxane, glycol methyl ether, glycol ethyl ether, glycol butyl ether; acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, methyl isobutyl ketone, 2-heptanone, 4-heptanone , Ketones such as diisobutyl ketone, acetonylacetone and mesityl oxide; industrial gasoline such as mineral spirit; and petrochemical solvents such as kerosene.

These may be used alone or in combination of two or more.

When the solvent is used, the concentration of the hydrophobic silica sol is usually 0.1% or higher, preferably 1% or higher. If the concentration of the hydrophobic silica sol is less than 0.1%, the object of the present invention may not be achieved.

Furthermore, the surface treatment agent of the present invention may contain an emulsifier, a resin mixture, and the like, if necessary, together with the hydrophobic silica sol and the solvent.

Examples of the emulsifier include fatty acid soap, ethercarboxylic acid and salts thereof, condensates of higher fatty acids and amino acids (N-acyl sarcosinate, N-acyl glutamate, etc.), higher alkyl sulfonates, α-olefin sulfone. Acid salt, sulfonate of higher fatty acid ester, dialkylsulfosuccinate, sulfonate of higher fatty acid amide, alkylallylsulfonate, alkylbenzenesulfonate, alkylnaphthalenesulfonate, formalin condensate of alkylallylsulfonate ,
Ion surfactants such as higher alcohol sulfate ester salts, alkyl and alkyl allyl ether sulfate ester salts, higher fatty acid ester sulfate ester salts, higher fatty acid alkylolamide sulfate ester salts, sulfated oils, and phosphate ester salts; alkylamines Salt, polyamine and amino alcohol fatty acid derivative, alkyl quaternary ammonium salt (alkyl trimethyl ammonium salt, dialkyl dimethyl ammonium salt, alkyl dimethyl benzyl ammonium salt, etc.), cyclic quaternary ammonium salt (alkyl pyrididinium salt, alkyl isoquinolin) A cation-containing surfactant such as a quaternary ammonium salt having a hydroxyl group, a quaternary ammonium salt having an ether bond, a quaternary ammonium salt having an amide bond; Le type nonionic surfactants, ether ester type nonionic surfactants, ester-type nonionic surfactant, a block polymer type nonionic surfactants,
Examples thereof include nonionic surfactants such as nitrogen-containing nonionic surfactants, but are not particularly limited.

When the emulsifier is used, the usage ratio is usually 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total amount of the hydrophobic silica sol and the diluent.

The resin mixture is not particularly limited, and examples thereof include vinyl acetate emulsion, vinyl chloride emulsion, vinylidene chloride chloride emulsion, and acrylic emulsion.

When the resin mixture is used, the usage ratio is usually 1 to 100 parts by weight, preferably 5 to 100 parts by weight, based on 100 parts by weight of the total amount of the hydrophobic silica sol and the diluent.

Examples of the method of applying the surface treatment agent of the present invention to a member such as concrete and mortar include a brush coating method, a spray method, a roller touch method, a bar coater method, and a dipping method.

For example, the surface treatment agent applied to the surface of the member by these methods penetrates into the inside of the member and achieves waterproofness while ensuring moisture permeability.

The surface-treating agent of the present invention having such characteristics can be suitably used for surface treatment of concrete, mortar, fiber, wood, steel, etc., and can be particularly suitably used for surface treatment of concrete and mortar. .

[Examples] Next, the present invention will be described more specifically by showing Examples and Comparative Examples of the present invention.

(Example 1) 1 g of concentrated sulfuric acid was added to 50 g of an aqueous solution of silica colloid (silica concentration 20%).
g was added dropwise and stirred, and then 300 g of isopropanol was added and mixed, and then azeotropic dehydration was carried out to react for 2 hours while removing water. Further, 50 g of lauryl alcohol was added and refluxed for 8 hours. This was concentrated to obtain a C ₁₂ organosilica sol having a hydrophobicity of 15.3% and a silica concentration of 16%.

The resulting C ₁₂ organosilica sol was neutralized by adding 4 g of N, N-dimethylethanolamine to obtain a surface treatment agent stock solution.

This stock solution of the surface treating agent was diluted with isopropanol to prepare a diluted product having a stock solution concentration of 3% to obtain a surface treating agent.

Next, a water permeation test and a moisture permeation test were performed on the obtained surface treatment agent.

The coating amount and the result are shown in Table 1.

The water permeability test and the moisture permeability test were conducted as follows.

Water permeability test: A surface treatment agent was applied to a flexible plate (100 × 100 × 6 mm), dried for 24 hours, and then subjected to a water permeability test according to JIS A6910.

Moisture Permeation Test; Surface treatment with circular 1-3 mortar plate (80φ x
20 mm) and dried for 24 hours, and then subjected to a moisture permeability test according to JIS Z208.

(Comparative Example 1) A flexible plate similar to that used in the water permeation test in Example 1 was subjected to the water permeation test according to Example 1 without applying the surface treatment agent of the present invention. A circular 1-3 mortar plate similar to the one used in the moisture permeability test in 1. was subjected to the moisture permeability test according to Example 1 above without applying the surface treatment agent of the present invention.

The results are shown in Table 1.

Reference Example The surface treatment agent prepared in Example 1 was applied to a circular 1-3 mortar plate (80φ × 20 mm), and the relationship between the applied amount and the water permeability and the relationship between the applied amount and the moisture permeability. I asked.

The relationship between the applied amount and the water permeability is shown in FIG. 1, and the relationship between the applied amount and the moisture permeability is shown in FIG.

The water permeability of the dough mortar before treatment with the surface treatment agent was 7.5 ml / 24 hr, and the moisture permeability thereof was 81 g / m ² · 24 hr.

(Evaluation) From the results of Example 1 and Comparative Example 1, in the flexible plate or mortar plate coated with the surface treatment agent of the present invention, the water permeability is reduced and the moisture permeability is improved. It was confirmed that the decrease in the air flow rate was small and the air permeability was sufficiently secured. Further, as is clear from FIG. 1, even if the coating amount is increased, there is no change in the decrease in water permeability, and therefore the surface treatment agent of the present invention can impart waterproofness with a small usage amount. It was confirmed that this was possible and that it could be sufficiently put to practical use. Further, as is clear from FIG. 2, even if the coating amount is increased, the decrease in moisture permeability is small, and therefore it was confirmed that sufficient air permeability is secured even when used in a large amount.

[Advantages of the Invention] According to the present invention, (1) since a specific silica sol is contained as an active ingredient, waterproofness can be imparted without impairing moisture permeability, and excellent permeability can be obtained. (2) Further penetration Since it has good properties and does not form a coating film, it exhibits sufficient waterproofness with a small amount of use, has good workability, and has good weather resistance. Porous construction such as concrete and mortar
When used for the surface treatment of civil engineering, it can provide waterproofness without impairing the air permeability of the skeleton, so it has advantages such as preventing the permeation of water from the outside and not causing dew condensation. A useful surface treating agent can be provided.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the coating amount and water permeability of the surface treatment agent of the present invention, and FIG. 2 is a graph showing the relationship between the coating amount and moisture permeability.

Claims (1)

[Claims] 1. A surface treating agent comprising, as an active ingredient, a hydrophobic silica sol obtained by treating the surface of the colloidal silica with a higher alcohol so that the hydrophobicity of the colloidal silica is 1% or more.