JPH10296070A - Modifying method for surface of earth and sand, powder and granular material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modifying method for a surface by which efficiency of a process and expense is contrived and such general-purpose properties are held that are capable of applying to not only ordinary material of construction but also reutilization of waste by using crude silane as a surface modifier for giving water repellency to earth and sand, powder and granular material. SOLUTION: In the modifying method for the surface of earth and sand, powder and granular material, a crude reaction product (crude silane) of silicon and methyl chloride or chlorobenzene is directly used as a surface modifier. A high reactive chlorine atom bonding to a silicon atom with a hydrocarbon group immediately takes the hydrogen atom of a hydroxyl group on the surface of material to be worked and becomes hydrogen chloride. The remaining oxygen atom bonds to a silicon atom having strong affinity and forms a water repellent trimethyl siloxy group and triphenyl siloxy group. Also, since these silanes are a monomer, molecular length is several to ten-add Å and extremely small and permeability is good. Further, stability is excellent because a film is not formed but chemical bonding of both a water repellent group and the surface of material to be worked is caused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides water repellency to industrial waste and general waste such as construction waste soil, construction waste sludge, and cinders, to protect buried objects, to prevent the generation of useless plants, and to stop water. The present invention relates to a method for modifying the surface of earth and sand, powder, and granular materials for imparting characteristics suitable for use and for recycling.

[0002]

2. Description of the Related Art Conventionally, film processing as a surface modification for imparting water repellency to earth and sand, powders and granules is performed by mixing a silicone product such as a dimethyl hydrogen siloxane polymer with an emulsion in water or simply stirring and mixing with water. Has been sprayed and then dried by heating. The production of silicone products used for this purpose requires quite a number of steps. First, a silane mixture is synthesized by a method called direct method in which silicon and methyl chloride, or silicon and chlorobenzene are combined under a copper-based catalyst, and then converted into several types of silane, a compound of a hydrocarbon group and hydrogen, silicon and chlorine. And the general formula is R (m + n) HmSiC1 (4-m + n) (1 ≦ m + n
≦ 3, m = 0or1, n = 1 to 3) R is distilled and distilled into a hydrocarbon group 加 水 and then hydrolyzed to obtain a hydroxyl group derivative called silanol. Hydrogen chloride generated during hydrolysis is treated and polycondensed by condensation polymerization to form a polysiloxane. The cyclic structure of the cyclosiloxane, which occupies a large portion of the polysiloxane, is opened (cracked) with concentrated sulfuric acid or the like to form a linear polysiloxane. After that, the hydroxyl groups at both ends of the molecular chain are replaced with a monofunctional hydrocarbon-silicon group to obtain a stable siloxane polymer.

[0003]

The silanes contained in the crude reaction product obtained by the direct synthesis of silicon and methyl chloride or chlorobenzene have similar boiling points, and fractional distillation is carried out by utilizing a slight difference in boiling points. Further, it is wasteful in terms of process to dilute the product purified through several steps of processing again and use it as a coating agent. In addition, economical waste of using materials that have become extremely expensive due to the purification process has been unavoidable. As an example, the boiling points of silanes contained in a crude reaction product of silicon and methyl chloride are generally as follows. (CH ₃ ) ₂ SiCl ₂ Boiling point 70 ° C. (CH ₃ ) SiCl ₃ Boiling point 66 ° C. SiHCl ₃ Boiling point 32 ° C. (CH ₃ ) HSiCl ₂ Boiling point 41 ° C. (CH ₃ ) ₃ SiCl Boiling point 57 ° C. SiCl ₄ Boiling point 57 ° C. The substances have close boiling points, and trimethylchlorosilane and silicon tetrachloride azeotrope. The crude reaction product of silicon and chlorobenzene also has a boiling point of (C ₆ H ₅ ) SiCl ₃ 201 ° C. (C ₆ H ₅ ) ₂ SiCl ₂ boiling point 309 ° C. (C ₆ H ₅ ) ₃ SiCl boiling point 207 ° C. . This is why fractionation requires large equipment and enormous costs. Furthermore, the costs required for subsequent purification, such as hydrolysis, hydrogen chloride recovery, condensation polymerization, ring opening, and substitution, make the price of the silicone product extremely expensive and hinder its use in a wider range of fields. Further, the molecular length of a silicone product used as a water-repellent treating agent for sediment-like materials or powders reaches several hundreds to 1,000 Å, and its permeability to a workpiece is not good. The present invention has been made to eliminate these disadvantages.

[0004]

The present invention is characterized in that a crude reaction product of silicon and methyl chloride or chlorobenzene (hereinafter referred to as crude silane) is directly used as a surface modifier.

[0005] Crude silane, a common intermediate of most silicone products, includes methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, methyldichlorosilane, and silicon-chlorobenzene reaction products for silicon-methyl chloride reaction products. Examples of the substance include phenyltrichlorosilane, diphenyldichlorosilane, and triphenylchlorosilane, all of which have a water-repellent hydrocarbon group. There are many other organic compounds with hydrocarbon groups that have water repellency, but the silanes obtained by these direct methods are different from other compounds because the extremely reactive chlorine atom has a hydrocarbon group. The point is that it is bonded to the silicon atom.

[0006]

[Function] A highly reactive chlorine atom bonded to a silicon atom having a hydrocarbon group instantaneously deprives a hydrogen atom of a hydroxyl group on the surface of a workpiece to become hydrogen chloride, and the remaining oxygen atom has an affinity. And water-repellent trimethylsiloxy and triphenylsiloxy groups.
In addition, since these silanes are monomers, their molecular length is as small as several to several tens of degrees, and their permeability is good. Also,
It is not a film but a chemical bond between the water-repellent group and the surface of the workpiece.

[0007]

[EXAMPLES] In the examples, waste soil excavated during burial work for sewage pipes was used. Rotary drum φ = 1500, L = 400
0 and a volume of 7 m ³ . Since agitation is required, a processing amount of about 1 m ³ per batch is appropriate for a drum of this size.
First, the remaining soil is sieved to a particle size of 0 to 5 mm, put into an airtight rotating drum, sealed, and then blower (vacuum generator)
Is operated to reduce the pressure to 300 to 350 mmHg. Crude silane is gasified by a heating vaporizer. The degree of heating is 90 ~
100 ° C may be sufficient. After closing the blower-side valve, the cock on the crude silane gas side is opened, and the crude silane gas is introduced into the drum until 1,000 cc of crude silane is consumed in liquid amount. Rotate the drum slowly at about 10 rpm and stir for 10 minutes. At this point, the pressure inside the drum is 5
It becomes 50-600 mmHg.

Next, an alkaline solution is mixed to treat the hydrogen chloride generated in the drum. In the example, 1,500 cc of a 20% sodium hydroxide solution was mixed and stirred at a rotation speed of 10 rpm for 10 minutes. After that, it is poured into a concrete tank filled with water, washed with water, drained and dried.
Since the amount of chlorine atoms contained in 1,000 cc of crude silane is about 17.05 mol, the amount of hydrogen chloride that can be generated is considered to be the same, but in actuality, it may be combined with metal ions present in the residual soil or unreacted. Not a few parts remain as they are. Therefore, a 20% sodium hydroxide solution was added to 3.0%.
When 100 cc, that is, 15 mol of [OH ⁻ ] ions are mixed and stirred, the cleaning solution shows remarkable alkalinity, but the pH value varies depending on the material used. If no hydrogen chloride odor remains when the material is taken out after the crude silane treatment, the removal of residual hydrogen chloride and inorganic salts (in this case, mainly sodium chloride) by water washing is sufficient.

The amount of processing per one processing is preferably about 1 m ³ , and the required amount of crude silane is about 1,000 cc, and it is increased or decreased according to the properties of the processing object. For a highly absorbent material, it may be necessary to increase the amount by about 50%. For other materials, for example, a material having a dense surface such as silica sand, half the amount may be sufficient. Depending on the application and construction site, the material may need to be mixed with red soil or colored with a dye, or the like, and the application to civil engineering materials such as masago, sand, and gravels is also useful.

[0010]

According to the present invention, the use of crude silane in the surface modification treatment for imparting water repellency to earth and sand, powders and granules results in a process and economy inevitable due to the conventional use of silicone products. Waste was eliminated. In addition, it has made possible the application of surface modification treatment in a wider range, and converted construction waste soil, construction sludge, cinders, etc., which had relied on landfill disposal of most of them as valuables or waste, into valuable resources, and Opened the way to use.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09K 17/36 B09B 3/00 304J

Claims (1)

[Claims] 1. A surface modification method for imparting water repellency by chemically bonding a hydrocarbon-silicon group to earth, sand, powder and granules.