KR100915216B1 - Production method of methylsiliconate monomer usable water-soluble water cutoff silicone from wasted chlorosilane - Google Patents

Abstract

A method for manufacturing a methylsiliconate monomer which is able to use as aqueous water repellent from waste silane chloride is provided to produce aqueous silicon water repellent which is widely used in industry using waste by-product of silane. A method for manufacturing a methylsiliconate monomer which is able to use as an aqueous silicon water repellent from waste silane chloride comprises: a step of adding KOH or NaOH in waste silane chloride containing MTCS (methyltrichloro silane) to hydrolyse mixture in alkaline pH; a step of separating aqueous solution in the mixture to isolated methylsiliconate monomer of the structural formula 1 or 2; and a step of adding an active carbon, filtering and concentrating the methylsiliconate monomer. The waste silane chloride mixture comprises TMCS, DMDCS(dimethyldichloro Silane), alkan of 4-9 carbon atoms, trisiloxane, hydrosilane or cyclic compound.

Description

Production Method of Methylsiliconate Monomer Usable Water-Soluble Water Cutoff Silicone from Wasted ChloroSilane

The present invention relates to a process for the preparation of methylsiliconate monomers usable from waste silanes as aqueous silicone water repellents.

Water repellents play an important role in protecting the exterior of concrete, bricks and tiles, which are an important part of today's building materials. Concrete, bricks, and ties have the disadvantage of easily absorbing moisture because they have many fine holes. Moisture absorbed on the wall lowers the thermal insulation effect, and not only cracks the wall surface due to expansion and contraction, but also drops the exterior materials such as tiles from the wall, creates stains and damages the exterior, and shortens the life of the building. Sometimes. Therefore, various methods are used to solve this problem, one of which is to treat the wall surface with a water repellent.

Generally, a water repellent is defined as a substance that does not change the internal structure of the base material and forms a hydrophobic film on the surface to prevent permeation of water, and an organic solvent type or an emulsifier in which a hydrophobic substance is dissolved in an organic solvent is applied to water. The emulsifier type to disperse is widely used, and three types of water repellents, which are water repellents that are converted into high molecular materials after reacting with carbon dioxide gas in the air which is made of low molecular perfect water, are widely used.

The organic solvent type has the problem of fire and polluting the air due to the volatilization of the organic solvent, and the emulsifier type has the presence of emulsifier itself, so that water in the air can be dissolved in the water repellent agent by the emulsifier. There is a problem, and full water solubility requires a considerable period of 2 to 14 days in order to have water repellency, but it is widely used in developed countries due to its environmental aspects, excellent water repellency and economic efficiency, but is still well used in Korea. It is not known water repellent.

Silicone water repellent is applied to the surface of the building to reduce the absorption of water is used to extend the life of the building. This high effect is derived from the characteristic properties of silicon itself, which has a very low surface tension compared to water, and thus has a good spreadability, and applies this spreading to the surface of the fine pores of a building. In other words, since the silicon penetrant not only chemically prevents the increase of moisture on the exterior wall of the building, but also is used to impart hydrophobicity, the penetrating ability of the silicon penetrant used in the above-mentioned field is very important.

In addition, silicone has been used as a raw material of the permeable surface water repellent for a long time, so far known solvent-type water repellents are silane type, polysiloxane type, silane and siloxane mixed type, and these are applied in different fields according to their characteristics. Generally used solvent-type silane water repellents are small in size of the molecule is coated on the surface of the building, such as concrete exhibits excellent permeability and good water repellency. In addition, the solvent-type polysiloxane water repellent has a relatively high molecular weight and a relatively low permeability, but the high water repellency of the painted surface can effectively prevent the water permeation of the baking surface, thereby protecting the building and extending its life. However, the solvent-type silane water-repellent is a loss in the coating due to the high volatility, the amount of alcohol generated in the hydrolysis has a problem that the coating environment is not good, the solvent-type polysiloxane water-repellent is a low volatility, the coating loss On the other hand, since the permeability is low, if the loss of the water repellent due to the surface damage after coating on the building wall, etc., the water repellency is remarkably degraded, causing the concrete interior to decrease the lifespan due to moisture.

Conventional silicone water repellent is to use an alkoxy silane, Application No. 10-2003-0011484 relates to a method for producing isobutyltrialkoxysilane which is one kind of the alkoxy silane, Application No. 10-2003-0011484 Relates to aqueous emulsions of alkylalkoxysilanes which are useful as infiltration inhibitors to maintain stable emulsions for long periods of time and to prevent water from being absorbed by porous inorganic building materials such as concrete. Application No. 10-2003-0013404 discloses alkoxy. A method for producing a water-repellent alkoxy siloxane oligomer by cohydrolysis of silane, wherein a portion of a hydrolyzable alkoxy group is coated on the exterior wall of a concrete building by hydrolysis and condensation of the alkoxy silane monomer using water and an acid catalyst. It is used as a solvent-type permeable silicone water repellent raw material. However, these methods are bypasses to those for preparing alkoxy siloxane oligomers using alkoxy silane monomers to produce siloxanes.

The present inventors have already applied for a patent for producing silicone oil from waste silicon compounds (Application No. 10-2008-0032138), and the world's leading silicon major companies (Dow corning, MPM, Walker, KCC, Shinetsu, Rhodia, etc.) Various types of silane waste by-products generated during the synthesis and purification of the silane compound, which is the basic raw material of the compound, are generated. Dow Corning, Momentive (formerly GE / Bayer) and Wacker Silicone Co., Ltd., currently producing genuine silicone oils, contain a mixture of silicon metal powder and methyl chloride by vapor phase reaction in a 250-300 ° C column reactor. Dimethyldichlorosilane (M2) and trimethylchlorosilane (M3) required for heavy silicone rubber (HTV, LSR, RTV-2) and sealant (RTV-1) are fractionally distilled to make oils and polymers, and methyltrichlorosilane (M1) is a sealant curing agent. The remaining distillation residue (waste silane hydrolyzate) is used as a crosslinker and is no longer useful as a composite composition of aliphatic hydrocarbons and undistilled M1 + M2 + M3 azeotropic mixture and disilane and high boiling point trisilane. It has not been incinerated or solidified with quicklime and has been buried underground.

Such waste silane hydrolyzate is called MS oil (methyl siloxane oil) or waste hydrolysate and produces about 2-4% of the production capacity when producing genuine silicone oil. As a result, the world's silicon major companies emit tens of thousands of tonnes of waste silane water. This not only pollutes the global environment, but also raises the cost of collecting the scattering of SiO ₂ fumed silica, which is a nanoparticle generated when incinerated. Incineration of one tonne of waste produces about 500 kg of fumed silica powder and about 700 kg of carbon dioxide.

To solve this problem, multinational silicon major companies have been trying to find a partner that can recycle such waste silane hydrolyzate for many years, but have not succeeded. Because the conventional alkaline cracking method applied, all silicon partners rejected the trihydroxy silane in the waste silane hydrolyzate immediately, making the entire crosslinked polymer gel and disabling the reaction plant. . This is because waste silane water is avoided as a non-recyclable material. The patent application (Application No. 10-2008-0032138) for producing silicone oil from the above-mentioned waste silicon compound filed by the present inventors has been to provide a development of such a highly value-added sealant as a plasticizer.

Accordingly, the present inventors further studied the use of the waste silicon compound based on the experience of producing the silicon compound for many years, and then dissolved the silane containing the trifunctional group in various types of waste silane mixture with a base and then separated by oil and water to separate the water layer. The present invention was completed by preparing an aqueous water repellent by first separating the silane mixture in the form of a water-soluble alkali in the form of silicon and decolorizing and filtering and purifying it using activated carbon, and confirming that the water repellent acts effectively as an aqueous water repellent.

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous water repellent that is widely used industrially using waste by-products of silane produced during the preparation of a silane compound, which is a raw material of a silicone compound.

In order to solve the above problems, the present invention comprises the steps of: iii) hydrolyzing the mixture at alkaline pH by adding KOH or NaOH to the waste silane mixture including MTCS (methyltrichloro Silane); And ii) separating only the aqueous solution from the hydrolyzed mixture by oil and water to separate the methylsiliconate monomer having the following Chemical Formula 1 or Chemical Formula 2; It provides a method for producing a monomer.

<Structure 1>

<Formula 2>

Hereinafter, the present invention will be described in more detail.

In the method for producing a methylsiliconate monomer which can be used as an aqueous silicone water repellent agent from waste silane chloride of the present invention, it is preferable that the net decomposition is performed at pH 11 to 13, and the waste silane mixture is TMCS (trimethylchloro Silane), in addition to MTCS, It is preferable to include at least one material selected from the group consisting of dimethyl dichloro silane (DMDCS), alkanes having 4 to 9 carbon atoms, trisiloxane, hydrosilane, and cyclic compounds.

In addition, in the method for producing a methylsiliconate monomer available from the waste silane chloride of the present invention as an aqueous silicone water repellent, after step ii), it is preferable to further include the step of filtration and concentration by adding activated carbon to the aqueous solution. In this case, the activated carbon is more preferably added 0.1 to 10 parts by weight to 100 parts by weight of the separated aqueous solution. In addition, "part by weight" in the present invention is to express the weight of each composition component as a ratio.

Summary of the present invention to prepare a silicone oil from the previously applied waste silicon compound as follows.

GC analysis of some of the waste silane hydrolysates allows for possible structural formulas: C ₆ H ₆ 12.02%, C ₆ H ₁₈ OSi ₂ 13.35%, C ₇ H ₁₆ 2%, C ₆ H ₁₈ Si ₂ 30.07%, C ₈ H ₁₈ 6.1%, C ₈ H ₁₆ 3.11%, C ₉ H ₂₀ 14.86%, C ₈ H ₂₄ O ₂ Si ₃ 4.23%, C1 ₂ H ₃₀ OSi ₄ 10.85%, C ₈ H ₂₄ O ₄ SiO ₄ 3.41% It was like Reclassifying these substances: 1) Hexane, Heptane, other hydrocarbons 25-35%, 2) Hexamethyldisiloxane, other trisiloxanes 10-15%, 3) D3, D4, D5 ^* , other Cyclic compounds 25-35%, 4) Disilane, Trihydroxysilane and other Hydrosilanes 10-15%. At this time, ^* (D3 = Hexamethylcyclotrisiloxane) ^* (D4 = Octamethylcyclotetrasiloxane) ^* (D5 = Decamethylcyclopentasiloxane).

Of these substances, 2) and 3) can be usefully used as a constituent of silicone oil, but the substances of 4) can not be separated by distillation. Cause symptoms. In this case, trihydroxy silane (trifunctional) in the present invention was a material to be removed as a by-product generated in the production of silicone oil.

In the industrial production of silane compounds, SiO ₂ in sand or the like is generally reacted with carbon such as excess graphite and coal at high temperature to remove O ₂ with CO ₂ to prepare metal-like Si, and to produce silicon. It is called (silicon). The metallic silicon is reacted at a high temperature of 450 ° C. under a catalyst such as CH ₃ Cl and copper to prepare various Methylchloro Silane consisting of (CH ₃ ) _n Si (Cl) _n . Depending on the number of methyl groups (CH ₃ ), a mixture of monofunctional (M3, trimethylchlorosilane), difunctional (M2, dimethyldichlorosilane), trifunctional (M1, methyltrichlorosilane), and tetrafunctional (M0, tetrachlorosilane) may occur. . Their proportions vary depending on the reaction conditions, typically 65-85% M2, 7-18% M1, 2-4% M3, ~ 0.5% CH ₃ SiHCl ₂ , and 6-8% other polysilanes. do. They are purified by methods using differences in boiling points such as fractional distillation. However, they have very similar boiling points, so 2 to 4% of the methylchloro silanes produced are called MSR (methysilane residue) and are removed by incineration as waste by-products. Silicone oil filed previously is a method using such a waste silicon compound.

The present invention is another method using the waste silicon compound, specifically trifunctional (M1, methyltrichlorosilane) method. Among the methylchloro Silanes prepared above, M2 is the most widely used methylchloro Silane because it can produce linear siloxane by condensation reaction in which water is removed. To make it available as a water repellent.

When explaining the step of preparing a methylsiliconate monomer usable as an aqueous silicone water repellent of the present invention.

First step: hydrolyzing the mixture at alkaline pH by adding KOH or NaOH to the waste silane mixture including MTCS (methyltrichloro Silane)

Appropriate amount of KOH or NaOH is added to the waste methylsilane mixture (MSM) containing MTCS. Approximately pH 11-13, preferably pH 12 or so. This reaction produces a methylsiliconate monomer in which two of the Cl groups in the methylchloro silane are converted to hydroxyl groups and one Cl is converted to OK or ONa (Scheme). The same reaction occurs with the remaining methylchloro Silanes in the silane mixtures other than MTCS.

<Scheme>

Second step: separating the methylsiliconate monomer by oil and water separation of the aqueous solution;

In the waste silane mixture, M3, M2 and other hydrocarbons such as alkanes, aliphatic, trisiloxane, Hydrosilane, and Cyclic compounds all exhibit hydrophobic properties that are soluble only in organic solvents, whereas the methylsiliconate monomers produced in M1 are easily soluble in water. Indicates.

Step 3: adding activated carbon to the aqueous methylsiliconate monomer, filtration and concentration

In addition to the methylsiliconate monomer in the aqueous solution may be dissolved in other substances of low molecular weight, the methylsiliconate monomer is purified and concentrated at a high concentration using activated carbon that transmits a low molecular weight. At this time, the activated carbon used is preferably NORIT (activated carbon) is used.

Step 4: preparing an aqueous silicone water repellent by reacting the methylsiliconate monomer

Industrially, when the methylsiliconate monomer prepared above is applied to an appropriate site, it is present in a water repellent in the form of a base silicone monomer, and slowly dissociates into a carbonate by gradually combining with carbon dioxide gas in the air (usually 2 to 2 weeks), and monomer basic Siliconates are converted to the hydroxide form and then polymerized into water-insoluble polysiloxanes, making them water repellents that do not penetrate water.

The water-soluble water repellent is a methylsiliconate monomer soluble in water, more preferably potassium methylsiliconate, the main component, it is used as a water-soluble water repellent for the colorless building wall final finish that allows water vapor to pass through the building walls, but water is sufficiently water repellent. Foreign substances are also used to block water vapor from rising and are effective for 10 to 20 years if installed.

Rainwater penetrates the exposed building surface to dissolve soluble salts, which eventually build up and stain the dissolved salts on the building surface. This phenomenon is called efflorescence and makes the building unsightly. The main problems caused by the exposure of the concrete surface are the patch phenomenon caused by the difference in the compaction due to the difference in absorbency, the hair cracking due to the growth of moss, the corrosion of the steel bars, and the moisture on the wall. As the ice breaks in and forms ice repeatedly, wall cracking may occur. In addition, pottery products, such as crab, brick, and matt floor tiles, baked at low temperatures, absorb water or contain water-soluble salts, which are transferred to the surface of the product, or become unsightly products. Eventually it will collapse. In addition, low-temperature baked porcelain products containing limestone do not pulverize the CaO / MgO particles sufficiently and do not migrate to silicates that react with water during baking, resulting in large holes in the surface. Moist pottery products have a common problem that causes moss or algae to grow and damage the appearance of the building. This phenomenon is observed only when there is moisture on the building surface. If this could be minimized or prevented, this would be avoided.

The silicate prepared by the method of the present invention prevents the formation of white cloudiness (whitening of salt absorption) and keeps the floor tiles clean, thereby providing safety, health and comfort of people living in concrete or buildings. do.

As described above, the present invention dissolves a silane containing trifunctional group in various forms of waste silane mixture as a base, and then separates oil and water in the silane mixture in the form of a water-soluble base in the form of a silicate. Decolorization and filtration to prepare a water-based water repellent.

The water-based water repellent prepared by the above method is present in the water repellent in the form of a base silicone monomer, and when used, is gradually dissolved (usually 2 days to 2 weeks) with carbon dioxide gas in the air to dissociate into carbonate, and the monomer basic silicon is hydroxide. After changing to form, they are polymerized into insoluble polysiloxane and used as a water repellent that does not penetrate water.

An effective raw material of the water repellent is silane, which is a trifunctional group, and various types of trifunctional silanes (OH)-, Cl-, or a combination thereof may be used, and such silane is mixed with a mono, di, or tetrafunctional group. You can use them.

Specifically, the method for preparing a water-soluble silicone water repellent agent of the present invention is to slowly add a basic liquid such as NaOH or KOH while stirring a high-speed waste silane mixture containing trisilane as a trifunctional group in a high-speed homomixer at Decomposition, it is separated by oil and water with a centrifuge to take only an aqueous solution, added about 1% of activated carbon, and then filtered and concentrated to prepare a methylsiliconate monomer usable as an aqueous silicone water repellent.

The methylsiliconate monomer according to the present invention obtained by the above process is a water-based widely used industrially in addition to the use of waste by-products of the silane produced in the manufacturing process of the silane compound which is a raw material of the silicon compound, such as building materials It can be used as a silicone water repellent.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are only for illustrating the present invention, and the present invention is not limited to the following examples and may be changed to other embodiments equivalent to substitutions and equivalents without departing from the technical spirit of the present invention. Will be apparent to those of ordinary skill in the art.

Example 1 Preparation of Methylsiliconate Monomer 1

A methylsiliconate monomer was prepared using the waste silane mixture having the following composition as a raw material.

MTCS (methyl trichloro Silane, MW = 149.48 bp = 66.4 ℃): 45%

TMCS (trimethyl chloro Silane, MW = 108.64 bp = 57.6 ℃): 35%

DMDCS (dimethyl dichloro Silane, MW = 129.06 bp = 70 ℃): 13%

hydrocarbon: 7%

200 g of the waste silane mixture was placed in a high-speed homomixer having a capacity of 2 liters, and slowly added 20% NaOH solution while stirring at 500 rpm to hydrolyze to pH 12, followed by oil and water separation with a centrifuge to obtain activated carbon. After adding 1% (NORIT, activated carbon, Osung Envitech), concentrated by filtration to prepare a methylsiliconate monomer that can be used as an aqueous water repellent.

The specification of the methylsiliconate monomer is as follows.

Specific gravity: 1.32 (20 ℃)

Alkaline degree: 20%

Color: Light Crest Color

Evaporation residue (solid component): 48%

Example 2 Preparation of Methylsiliconate Monomer 2

A methylsiliconate monomer was prepared using the waste silane mixture having the following composition as a raw material.

MTCS (methyl trichloro Silane, MW = 149.48 bp = 66.4 ℃): 38%

TMCS (trimethyl chloro Silane, MW = 108.64 bp = 57.6 ℃): 42%

DMDCS (dimethyl dichloro Silane, MW = 129.06 bp = 70 ℃): 20%

200 g of the waste silane mixture was placed in a high-speed homomixer having a capacity of 2 liters, and slowly added 20% NaOH solution while stirring at 500 rpm to hydrolyze to pH 12, followed by oil and water separation with a centrifuge to obtain activated carbon. After adding 1% (NORIT, activated carbon, Osung Envitech), concentrated by filtration to prepare a methylsiliconate monomer that can be used as an aqueous water repellent.

It was almost identical to the specification example 1 of the said methylsiliconate monomer.

Experimental Example 1 Water repellency test 1

After diluting the methylsiliconate monomer obtained in Examples 1 and 2 by 5 times, 5 ml was applied to 150 mm of ACVANTEC (toyo) qualitative filter paper and left for 3 days to use as an aqueous water repellent. The water-repellent water-repellent agent is a silicate monomer form of the base is slowly combined with carbonic acid gas in the air to dissociate into a carbonate, monomer basic siliconate is changed to the hydroxide form, they are polymerized into an insoluble polysiloxane and does not penetrate water Becomes

When 0.5 ml of water was dropped on the application site, water repellency was excellent at 130 degrees or more of the incident angle, and there was no change after 1 day. As a water-based silicone water repellent, the results were comparable.

Experimental Example 2 Water Repellency Test 2

The water repellency of the methylsiliconate monomers synthesized according to Examples 1 and 2 was measured by the following method. Specifically, the methylsiliconate monomer was diluted 5 times and coated on a concrete specimen of 5 × 5 × 5 cm compressive strength 270 kg / cm 2 cured for 27 days to test water repellency and other items. The same test (Comparative Example 1) was applied to isobutyltriethoxy silane as a silane monomer commonly used in water repellents for physical property comparison.

Volatilization loss was measured by leaving 5 g of the sample in a 105 ℃ oven for 3 hours, Example 1 was 15 wt%, Example 2 was 14 wt%, Comparative Example 1 was 100% wt%. The methylsiliconate monomers of the present invention were relatively water soluble and relatively low in volatility.

In addition, the surface water repellency was observed with the naked eye after the water repellent was applied to the specimen by dropping 1 ml of water on the surface, both examples and comparative examples were good.

In addition, the absorption ratio was compared by measuring the amount of water absorbed by immersing the water-repellent coated specimen and the unpainted specimen in water for 1 hour (water absorption of the coated specimen / water absorption of the non-water repellent specimen), It was confirmed that Example 1 is 0.05, Example 2 is 0.06, and Comparative Example 1 is 0.11, and the absorption ratio is very excellent.

Claims (5)

Iii) hydrolyzing the mixture at an alkaline pH by adding KOH or NaOH to the spent silane chloride mixture including MTCS (methyltrichloro Silane); Ii) separating only the aqueous solution from the hydrolyzed mixture by oil and water to separate the methylsiliconate monomer consisting of the following Formula 1 or Formula 2; And Iii) filtering and concentrating the methylsiliconate monomer by adding activated carbon to the aqueous solution; and a method for preparing a methylsiliconate monomer which can be used as an aqueous silicone water repellent agent from waste silane. <Structure 1>

<Formula 2>

The method of claim 1, wherein the pure decomposition is a method of producing a methylsiliconate monomer, characterized in that at pH 11 to 13. The method of claim 1, wherein the waste silane silane mixture contains one or more substances selected from the group consisting of trimethylchloro silane (TMCS), dimethyldichloro silane (DMDCS), alkanes having 4 to 9 carbon atoms, trisiloxane, hydrosilane, and cyclic compounds in addition to MTCS. Method for producing a methylsiliconate monomer, characterized in that. delete The method of claim 1, wherein the activated carbon is 0.1 to 10 parts by weight of the separated aqueous solution is added to the method for producing a methylsiliconate monomer.