JP2017025181A - Silane/siloxane-based emulsion for concrete treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silane/siloxane-based emulsion having excellent permeability to a civil engineering structure concrete and without causing liquid sagging even when applied to a vertical surface.SOLUTION: There is provided a silane/siloxane-based emulsion for concrete treatment used for a structure, consisting of (A) alkylalkoxysilane and (B) polyorganosiloxane, (C) an emulsifier and (D) water, where (A) is one represented by the general formula RSi(OR), where Ris an alkyl group having 1 to 20 carbon atoms, Ris an alkyl group having 1 to 6 carbon atoms or a hydrogen atom and X is an integer of 1 or 2, (B) is one represented by the average composition formula R(OR)Si(OH)O, where Ris an alkyl group having 1 to 20 carbon atoms, Ris an alkyl group having 1 to 6 carbon atoms, a, b and c are each any value of 0<a≤2.0, 0≤b<2.0 and 0≤c<2.0 and a+b+c is 3 or less, and having mass ratio of the (A) component and the (B) component (A/B) of 10/1 to 1/1 and total amount of the (A) component and the (B) component of 60 to 90 wt.% in total component.SELECTED DRAWING: None

Description

The present invention relates to a creamy aqueous emulsion of an organosilicon compound used for the modification of concrete structures, in particular for the water repellent treatment of civil engineering concrete.

It has hitherto been known that the surface of a building material is made hydrophobic by applying it to various building materials using an organosilicon compound such as a silane compound or polysiloxane, and the penetration of water into the building material is suppressed. The target building materials are inorganic porous building materials such as concrete, mortar, lightweight cellular concrete, bricks, etc., and the above compounds penetrate into the pores of the porous building materials to make the surface layer hydrophobic, so that these building materials Deterioration and aging of the resin are suppressed, and water repellency is also imparted, so that there is an effect that the adhesion of dust and the generation of mold are suppressed and the dirt is hardly attached.

These compounds have been conventionally diluted in organic solvents, but they can be used as aqueous emulsions in order to eliminate concerns about environmental pollution caused by organic solvents that volatilize after application and the effect on work environment deterioration. Proposals have also been made regarding compounds or compositions that are desirable and suitable for use as aqueous emulsions.

  For example, Patent Document 1 discloses an emulsion in which an alkylalkoxysilane is dispersed in water using an emulsifier. Although this material penetrates into concrete, silane near the applied concrete surface tends to volatilize in the atmosphere, so it was necessary to coat the emulsion several times.

  Patent Documents 2 and 3 disclose silane / siloxane emulsions in which alkylalkoxypolysiloxane is used in combination with alkyltrialkoxysilane. Although this method is sufficient to hydrophobize the portion near the concrete surface to which the emulsion is applied, the emulsion has a low viscosity because the silane / siloxane concentration in the emulsion is as low as about 50% at the maximum, making it more dense like civil engineering structures. When it is applied to a place other than the horizontal plane of concrete, there is a drawback that dripping is likely to occur before penetration, and the concrete becomes hydrophobic.

  Patent Document 4 discloses a cream-like emulsion having a high silane / siloxane concentration, which is a polysiloxane having an alkylalkoxysilane and an amino group, or a silane / siloxane emulsion obtained by adding an alkylalkoxypolysiloxane thereto. Has been. Because it is creamy, dripping does not easily occur even when applied to a vertical surface of a civil engineering structure, but it does not have sufficient permeability to dense concrete for civil engineering, and it remains on the concrete surface and causes discoloration. It was.

Further, Patent Document 5 discloses an emulsion that sufficiently penetrates dense concrete by setting the mixing ratio of alkylalkoxysilane / polyorganosiloxane to 50/1 to 10/1. High permeability is ensured by a large proportion of alkylalkoxysilane, but in concrete whose surface has become sparse due to aging, the water repellency (hydrophobicity) of the concrete surface becomes weak due to volatilization of alkylalkoxysilane. there were.

Japanese Patent Laid-Open No. 62-197369 US Pat. No. 5,091,002 JP-T 6-501514 Japanese Patent Laid-Open No. 10-81824 JP 2004-338980 A

  These conventional silane / siloxane emulsions need to be applied many times, cause dripping when used on civil engineering structures made of dense concrete, and have permeability and initial repellency after application. It had the disadvantage of not being sufficiently aqueous.

The present invention has been made in view of the above circumstances, and since it is water-based, there is no concern about environmental pollution or deterioration of the working environment, and when used for a civil engineering structure that is a drawback of the above-described conventional technology. An object of the present invention is to solve the problem, that is, to provide a silane / siloxane emulsion that has excellent penetrating power and water repellency with respect to aged concrete and does not cause dripping.

In order to solve the above-mentioned problems, the present inventors have conducted intensive research on the structure and composition of each component of the silane / siloxane emulsion, and as a result, use a specific silane and polysiloxane, and a specific mixing ratio. As a result, the inventors have found that the problem can be solved, and have made the present invention. That is, the present invention
[1] It comprises (A) an alkylalkoxysilane, (B) a polyorganosiloxane, (C) an emulsifier, (D) water, and (A) is represented by the general formula (1)
(1) R ¹ XSi (OR ² ) _4-X
(Wherein R ¹ is an alkyl group having 1 to 20 carbon atoms, R ² is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, X is an integer of 1 or 2), and (B) is Average composition formula (2)
(2) R ³ _a (OR ⁴ ) _b Si (OH) _c O _{(4-abc) / 2} (wherein R ³ is an alkyl group having 1 to 20 carbon atoms, and R ⁴ is 1 carbon atom) -6 alkyl groups, a, b and c are arbitrary values of 0 <a ≦ 2.0, 0 ≦ b <2.0 and 0 ≦ c <2.0, respectively, and a + b + c is 3 or less) The weight ratio (A / B) of component (A) to component (B) is 10/1 to 1/1, and the total amount of component (A) and component (B) is the total composition. A silane / siloxane emulsion for treating concrete used in a structure, characterized in that it is 60 to 90% by weight in the product,

[2] The silane / siloxane emulsion according to [1], wherein R ¹ of component (A) has 4 to 10 carbon atoms and R ² has 1 or 2 carbon atoms,
[3] The silane / siloxane emulsion according to [1] or [2], which is used for water-repellent treatment of civil engineering structure concrete having a high unit cement amount kneaded at a water / cement weight ratio of 0.5 or less.

  The silane / siloxane-based aqueous emulsion of the present invention has excellent penetrating power for dense concrete, is creamy, and does not cause dripping even when applied to a vertical surface. When used as a treating agent, it has the effect of preventing the deterioration of the concrete, suppressing the adhesion of dust and mold, making it difficult to get dirty, and is extremely useful for concrete having a deteriorated surface.

Hereinafter, the present invention will be specifically described.
The alkylalkoxysilane which is the component (A) of the present invention is represented by the general formula (1).
(1) R ¹ _X Si (OR ² ) _4-X
(1) In the formula, R ¹ is the same or different alkyl group having 1 to 20 carbon atoms, R ² is the same or different alkyl group having 1 to 6 carbon atoms or a hydrogen atom, X is 1 Or it is an integer of 2.

Examples of R ¹ in the formula (1) are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, hexyl group such as n-hexyl group, heptyl group such as n-heptyl group, octyl group such as n-octyl group and 2,2,4-trimethylpentyl group, n-nonyl group Such as nonyl group, decyl group such as n-decyl group and alkyl group such as dodecyl group such as n-dodecyl group, cyclopentyl group, cyclohexyl group, 4-ethylcyclohexyl group, cycloheptyl group, norbornyl group and methylcyclohexyl group And may be the same or different in the molecule. Preferred R ¹ is an alkyl group having 4 to 10 carbon atoms.

Examples of R ² in formula (1) are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, A hexyl group such as a tert-pentyl group or an n-hexyl group, which may be the same or different in the molecule. Of these, preferred R ² is an alkyl group having 1 or 2 carbon atoms.

The polyorganosiloxane which is the component (B) of the present invention is represented by the average composition formula (2).
(2) R ³ _a (OR ⁴ ) _b Si (OH) _c O _{(4-abc) / 2}
In the formula, R ³ is an alkyl group having 1 to 20 carbon atoms, R ⁴ is an alkyl group having 1 to 6 carbon atoms, a, b, and c are 0 <a ≦ 2.0 and 0 ≦ b <2.0, respectively. It is an arbitrary value of 0 ≦ c <2.0, and a + b + c is 3 or less.

Examples of R ³ in the formula (2) are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, hexyl group such as n-hexyl group, heptyl group such as n-heptyl group, octyl group such as n-octyl group and 2,2,4-trimethylpentyl group, n-nonyl group Such as nonyl group, decyl group such as n-decyl group and alkyl group such as dodecyl group such as n-dodecyl group, cyclopentyl group, cyclohexyl group, 4-ethylcyclohexyl group, cycloheptyl group, norbornyl group and methylcyclohexyl A cycloalkyl group such as a group, which may be the same or different in the molecule.

Examples of R ⁴ in the formula (2) are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, A hexyl group such as a tert-pentyl group or an n-hexyl group, which may be the same or different in the molecule. Among these, preferable R ⁴ is an alkyl group having 1 or 2 carbon atoms.

The average composition in the formula (2) is 0 <a ≦ 2.0, 0 ≦ b <2.0, and 0 ≦ c <2.0, and preferably 0 <a ≦ 2. 0, 0 ≦ b <1.7, 0 ≦ c <0.5, and 1.0 <a + b + c <3.0.

  The viscosity of the component (B) is preferably 10 mPa · s to 2000 mPa · s at 25 ° C. If it is 10 mPa · s or less, or 2000 mPa · s or more, the penetration of the silane / siloxane component into the pores of the porous material is not uniform, which is not preferable. A particularly preferred viscosity is 10 mPa · s to 1000 mPa · s. The polyorganosiloxane (B) can be produced by a method known to those skilled in the art. For example, there are a method of hydrolyzing and condensing a mixture of methyltrichlorosilane and dimethyldichlorosilane in the presence of alcohol, and a method of hydrolyzing and condensing methyltrialkoxysilane and dimethyldialkoxysilane in the presence of an alkali catalyst. In the emulsion of the present invention, two or more of these polyorganosiloxanes can be mixed and used.

  In the emulsion of the present invention, the total amount of components (A) and (B) needs to be 60 to 90% by weight. If it is 60% by weight or less, the viscosity of the emulsion is not low and it is not creamy, and if it is 90% by weight or more, the viscosity of the emulsion is too high and the workability of coating is poor. The total amount of the preferred components (A) and (B) is 70 to 85% by weight, and the effects of the present invention are most exhibited within this range.

  In the emulsion of the present invention, the weight ratio (A / B) of the component (A) to the component (B) is 50/1 to 10/1. Outside this weight ratio range, high permeability to the porous building material of the present invention cannot be obtained.

Various known emulsifiers can be used in the emulsifier component (C) of the present invention. Specific examples of the emulsifier include an anion emulsifier having an alkyl sulfate having a chain length of 8 to 18 carbon atoms, an ethylene oxide having a carbon number of 8 to 18 in a hydrophobic group, and 1 to 40 ethylene oxide. Alkyl and alkaryl ether sulfates having (EO) or propylene oxide (PO) units, alkyl sulfonates having 8 to 18 carbon atoms, alkyl aryl sulfonates, esters of sulfosuccinic acid with monohydric alcohols or alkyl phenols and half Mention may be made of esters.

  Nonionic emulsifiers include polyvinyl alcohol, alkyl polyglycol ether comprising 3 to 40 ethylene oxide (EO) units and alkyl having 8 to 20 carbon atoms, ethylene oxide / propylene oxide (EO / PO) block copolymer Examples thereof include addition products and addition products of alkylamines with ethylene oxide or propylene oxide.

As cationic emulsifiers, salts of primary, secondary and tertiary fatty amines having 8 to 24 carbon atoms, quaternary alkyl and alkylbenzol ammonium salts, alkylpyridinium salts, alkylimidazolinium salts and alkyls Oxazolinium salts, long chain substituted amino acids, betaines and the like can be mentioned.

Preferred emulsifiers are nonionic emulsifiers, especially alkyl polyglycol ethers, addition products of alkyl amines with ethylene oxide or propylene oxide, and polyvinyl alcohol. The polyvinyl alcohol preferably contains 5 to 20% vinyl acetate units and has a polymerization degree of 500 to 3000.

The amount of the emulsifier used in the present invention is usually 0.1 to 10% by weight, preferably 0.1 to 5% by weight, based on the emulsion.

  In the emulsion of the present invention, it is effective to contain a buffer that stabilizes the pH within the range of 5 to 8 so that the silane of component (A) is stable against hydrolysis. Various organic and inorganic acids and bases that are chemically inert with respect to the other components of the emulsion can be used as buffering agents, such as alkali salts of carboxylic acid, phosphoric acid, carbonic acid and sulfuric acid, alkaline earths. Salts and ammonium salts are suitable. Sodium carbonate, sodium hydrogen carbonate, sodium hydrogen phosphate and a mixture of acetic acid and aqueous ammonia are more preferred. The amount of the buffer used is 3% by weight or less based on the emulsion.

To the emulsion of the present invention, fungicides, bactericides, algicides, microbicides, fragrances, anticorrosives and antifoaming agents can be added as long as the object of the present invention is not impaired. These additives are suitably in the range of 0.01 to 2% by weight with respect to the emulsion.

The emulsion according to the invention can be prepared by methods known to those skilled in the art. For example, an emulsion having a very low viscosity is first prepared from a part of components (A) and / or (B), an emulsifier and most of water, and then the remaining components (A) and / or (B) are added and emulsified. Or all of components (A) and (B) are emulsified with a portion of water and an emulsifier to form a water-in-oil emulsion, and the remaining water is added to continue the emulsification and phase change. A method can also be used. In these emulsification processes, it is preferable to use a pressure type emulsifier such as a colloid mill.

The emulsion according to the invention can be applied to building materials, in particular inorganic porous building materials such as concrete, mortar, lightweight cellular concrete, bricks, etc. by brushing or spraying. The coating amount of the emulsion according to the invention for these building materials 400 g / ^{m 2} or less, in particular 100 to 250 g / ^{m 2.} Since the emulsion of the present invention is creamy, it can be applied in a single amount, but it can also be overcoated.

The emulsion of the present invention is excellent in permeability to concrete, but this high permeability is particularly exhibited when used for dense concrete. The density of the concrete can be expressed by a water-cement ratio. A dense concrete having a water / cement weight ratio of 0.5 or less is used for civil engineering structures. The emulsion of the present invention is excellent in permeability to such a civil structure concrete, but it is creamy and combined with the advantage that it does not flow down even when applied to a vertical surface, the civil engineering structure already installed This is particularly effective when used on concrete surfaces. Structures in which the emulsion of the present invention is suitably used include not only those cast on site, but also precast concrete products and members manufactured in factories and yards.

Furthermore, the emulsion of the present invention can exhibit excellent water repellency after application even to dense concrete at the time of casting even to concrete whose surface has become sparse due to aging.

  The present invention will be specifically described based on examples, but the present invention is not limited to the following examples. The concrete specimen, the concrete coating property evaluation method, and the permeability evaluation method in the examples are as follows.

<Concrete specimen>
A concrete block having a water / cement ratio (W / C) of 0.4 or 0.6 and a size of 100 mm × 100 mm × 400 mm was used. Each concrete specimen has been air-dried for 28 days or more after demolding (atmosphere: temperature 20 ° C, humidity 60%), and has a surface moisture content of 4.5% using a high-frequency capacity concrete mortar moisture meter. Was used. Further, the concrete specimen was immersed in 1N hydrochloric acid for 24 hours to deteriorate the surface of the concrete specimen, and the specimen was thoroughly rinsed with running water. The concrete specimen after rinsing was sufficiently dried at room temperature, and a concrete specimen having a surface moisture content of 4.5% by a high-frequency capacity type concrete mortar moisture meter was used.

<Evaluation method of coatability>
It applied using a brush so that it might become 200 g / m < ² > with respect to the perpendicular | vertical surface of a concrete test body, and it was observed whether the emulsion applied by 3 minutes after application | coating dripped like a water drop.

<Permeability evaluation method>
The emulsion was applied to the specimen using a brush so as to have a density of 200 g / m ^2, and after air-drying for 3 days (atmosphere: temperature 20 ° C., humidity 60%), the penetration depth was measured. The penetration depth was determined by dividing the vertical surface from the concrete application surface and spraying water onto the split surface, measuring the length of the part that was not painted by water (hydrophobic layer), and calculating the average value of 20 measurements. The penetration depth.

<Evaluation method of water repellency>
With a dropper, 0.3 ml of tap water was dropped onto the coated surface, and the degree of water droplet repelling after 3 minutes of dropping was observed.

<Example 1>
As polyorganosiloxane component (B), 10 g of polyorganosiloxane (MS1) having a viscosity of about 30 mPa · s at 25 ° C. and a composition formula of CH ₃ Si (OC ₂ H ₅ ) _0.8 O _1.1 , and an emulsifier component (C ) 0.13 g of isotridecyl alcohol glycol ether (E1) having 10 ethylene oxide units and 10 g of water (D) are mixed and stirred at a high speed, and isooctyltriethoxysilane (iC8) as the alkylalkoxysilane component (A). ) 40 g was divided into 4 times and mixed and stirred at high speed to obtain an emulsion EM1. The composition and coatability evaluation are shown in Table 1, and the permeability and water repellency evaluation results are shown in Table 2.

<Example 2>
Emulsion EM2 was obtained in the same manner and in the same manner as in Example 1 except that isotridecyl alcohol glycol ether (E2) having 16 ethylene oxide units was used instead of the emulsifier component E1 of Example 1. The composition and coatability evaluation are shown in Table 1, and the permeability and water repellency evaluation results are shown in Table 2.

<Example 3>
Instead of the polyorganosiloxane component MS1 of Example 1, 2 g of a polyorganosiloxane (MS2) having a viscosity of about 100 mPa · s at 25 ° C. and an average composition formula (CH ₃ ) ₂ Si (OH) _0.05 O _0.98 Emulsion EM3 was obtained in the same manner and in the same manner as in Example 1 except that E2 was used instead of the emulsifier component E1. The composition and coatability evaluation are shown in Table 1, and the permeability and water repellency evaluation results are shown in Table 2.

<Comparative Example 1>
Emulsion EM4 was obtained in the same manner and in the same manner as in Example 1 except that 2 g of the organosiloxane component (MS1) of Example 1 and 38 g of isooctyltriethoxysilane (iC8) were used. The composition and coatability evaluation are shown in Table 1, and the permeability and water repellency evaluation results are shown in Table 2.

<Comparative example 2>
Instead of the polyorganosiloxane component MS1 of Example 1, polyorganosiloxane (AS) having an amine number of about 0.3 and a viscosity of about 500 mPa · s at 25 ° C. was used, and other than that, the same as Example 1 The emulsion EM5 was obtained in the same manner and in the same manner. The composition and coatability evaluation are shown in Table 1, and the permeability and water repellency evaluation results are shown in Table 2.

(Table 1)
Evaluation of ingredients and coatability

Legend of coatability ○: No liquid dripping X: Liquid dripping observed

(Table 2)
Penetration (penetration depth) and initial water repellency comparison

Water repellent legend ◎: Excellent water repellency, water droplets are easy to roll on the coated surface
○: Water repellent, but water drops do not roll on the coated surface

Since the silane / siloxane emulsion of the present invention is aqueous, there is no concern about environmental pollution and work environment deterioration, and it has excellent penetrating power and water repellency for aged concrete. It is a suitable material for concrete processing that does not occur.

Legend of coatability ○: No liquid dripping X: Liquid dripping observed

Water repellent legend ◎: Excellent water repellency, water droplets are easy to roll on the coated surface
○: Water repellent, but water drops do not roll on the coated surface

Legend of coatability ○: No liquid dripping X: Liquid dripping observed

Water repellent legend ◎: Excellent water repellency, water droplets are easy to roll on the coated surface
○: Water repellent, but water drops do not roll on the coated surface

Claims (3)

(A) An alkylalkoxysilane, (B) a polyorganosiloxane, (C) an emulsifier, (D) water, and (A) is represented by the general formula (1)
(1) R ¹ _X Si (OR ² ) _4-X (wherein R ¹ is an alkyl group having 1 to 20 carbon atoms, R ² is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom, and X is 1 or 2) Integer)
Where (B) is the average composition formula (2)
(2) R ³ _a (OR ⁴ ) _b Si (OH) _c O _{(4-abc) / 2} (wherein R ³ is an alkyl group having 1 to 20 carbon atoms, and R ⁴ is 1 carbon atom) -6 alkyl groups, a, b and c are arbitrary values of 0 <a ≦ 2.0, 0 ≦ b <2.0 and 0 ≦ c <2.0, respectively, and a + b + c is 3 or less)
The weight ratio (A / B) of component (A) to component (B) is 10/1 to 1/1, and the total amount of component (A) and component (B) is the total composition. A silane / siloxane emulsion for treating concrete used in a structure, characterized in that it is 60 to 90% by weight in the product. The silane / siloxane emulsion according to claim 1, wherein R ¹ of component (A) has 4 to 10 carbon atoms and R ² has 1 or 2 carbon atoms. The silane / siloxane emulsion according to claim 1 or 2, which is used for water-repellent treatment of civil engineering structure concrete having a high unit cement content kneaded at a water / cement weight ratio of 0.5 or less.