JPH0625537A - Production of asphalt powder particle - Google Patents

Abstract

PURPOSE:To rationalize the packaging, storing and transporting, simplify the execution and develop new uses by powdering asphalt having consistency at ordinary temperature. CONSTITUTION:Water containing suspended amphiphatic particles in which the surfaces of hydrophilic inorganic particles are coated with a lipophilic substance is stirred and mixed with a heated asphalt having a low viscosity to afford an asphalt emulsion. A water-soluble polymer compound in an amount of >=1wt.% based on the asphalt is subsequently added to the asphalt emulsion and the obtained mixture is then spray-dried.

Description

Detailed Description of the Invention

[0001]

The present invention relates to asphalt, which is viscous (not solid) even at normal temperature, is pulverized to be rationalized for storage, packaging, transportation, etc., and is convenient for use. And a method for producing asphalt powder, which is expected to open up new applications.

[0002]

2. Description of the Related Art Asphalt (bituminous material) is a material that is naturally produced and has been used in many fields for a long time. Therefore, most of the currently commonly used petroleum asphalt. These asphalts are cheap, their adhesive strength, bonding strength, waterproofness,
It is widely used in many fields such as road pavement, irrigation work, waterproofing work, electric insulation materials, various coating materials, etc. by utilizing characteristics such as vibration control, rust prevention and electric insulation. And
Depending on the application, it is called straight asphalt, blown asphalt, cutback asphalt, etc.
Many varieties with different compositions and penetration (hardness) are manufactured and supplied.

[0003]

These asphalts generally have a high softening point and are viscous liquids, semi-solids or solids at room temperature, and have poor fluidity, so they are heated and melted and softened during use. At the very least, it was necessary to make the viscosity suitable for work before use, and this, combined with the inconvenience of storage and transportation, prevented the expansion of applications. In order to eliminate these drawbacks and facilitate handling, emulsifiers are used,
An asphalt emulsion in which asphalt is emulsified and suspended in water, so-called anion emulsion or cation emulsion, has been developed. However, while this eliminates the need for heating, melting, etc., the asphalt concentration in the asphalt emulsion is about 50%, so approximately the same amount of water as asphalt is stored and transported at the same time. Facility,
Transportation costs will increase. However, the biggest problem is that a large amount of emulsifiers, stabilizers, etc. are added to force emulsification, so the physical properties of asphalt may deteriorate due to the effects of these additives, and the evaporation of water However, there was a defect such as slow drying.

[0004]

The inventors of the present invention prevent the deterioration of various physical properties of asphalt due to forced emulsification by using a large amount of these conventional surfactants, stabilizers and the like, In order to further develop new applications, as a result of repeated research focusing on emulsifying asphalt using inorganic particles having hydrophilicity and lipophilicity (called amphiphilic particles), amphiphilic With proper selection of particles, mixing ratio with asphalt, temperature, emulsification conditions such as PH, selection of emulsifying equipment, etc., it is found that an asphalt soap press emulsion using amphiphilic particles can be effectively produced,
Further, they have found that an asphalt dry powder having excellent utility value can be produced from the asphalt emulsion particles, and have reached the present invention.

The base material of the amphipathic substance used in the production method of the present invention is hydrophilic inorganic particles, which have water affinity and are hardly soluble or insoluble in water, and are substantially soluble in water. Insoluble substances are included. Examples of such substances include silicon dioxide, oxides such as alumina and titanium dioxide, heavy or light calcium carbonate, carbonates such as magnesium carbonate, silicates such as kaolin, clay and talc, and aluminum hydroxide, Hydroxides such as magnesium hydroxide,
Examples thereof include sulfates such as barium sulfate and calcium sulfate. To make these inorganic particle materials amphiphilic,
Usually, a single species is advantageously used, but two or more species may be used in combination, or two or more species may be mixed and used after being amphipathic. However, considering the unit price and the diameter of particles that can be industrially provided, practically particularly preferable materials are silicon dioxide, calcium carbonate, talc and the like. When using an amphipathic particle to produce an asphalt emulsion, generally there is a correlation between the particle size of the amphipathic particle used and the particle size of the asphalt in the generated asphalt emulsion, As the size of the amphiphilic particles increases, the size of the asphalt particles in the generated asphalt emulsion also increases.

Therefore, when an asphalt emulsion is produced by this method and is not used, the storage stability of the asphalt emulsion is ensured as much as possible.
It is necessary to use fine inorganic particles, preferably amphiphilic particles of 0.6 μm or less are used. However, in the case of producing the dry asphalt particles of the present invention, if the particle size is such that the asphalt can be suspended or emulsified in water by the amphipathic particles, the obtained asphalt dispersion is directly dried. By doing so, it can be pulverized. Thus, using the amphipathic particles, the surface of the asphalt particles in the obtained asphalt emulsion is an inorganic layer formed by the amphipathic particles to prevent fusion of asphalt particles, coalescence, It is effective in stabilizing the asphalt emulsion.

Further, it is important that the lipophilic substance used for surface modification of the hydrophilic inorganic material is a substance that fixedly forms a hydrophobic portion on the surface of the inorganic particles, such as a silane compound or a titanate-based cup. Examples thereof include a ring agent, an oil-soluble polyamine condensate, an acrylic acid-based polymer, and a copolymer thereof. These may be used as a single substance or may be used in combination of two or more components. . In producing a dry powder from an asphalt emulsion obtained by using amphiphilic particles, since it is exposed to a high temperature to evaporate water, the core material covered with an inorganic substance is used. Since the asphalt has a low viscosity and increases fluidity, fusion between asphalt particles is likely to occur.
In order to prevent this concern, a water-soluble polymer compound such as gum arabic, gelatin, polyvinylpyrrolidone, polyvinyl alcohol, carboxymethyl cellulose and the like is previously added to asphalt in an asphalt emulsion.
%, And if dried, an asphalt powder can be obtained. In this case, the film thickness of the polymer film covering the asphalt surface of the core material naturally differs depending on the addition amount of the water-soluble polymer compound, so it is desirable to determine the addition amount depending on the purpose of use. The equipment used for drying is
A spray dryer is industrially preferable.

[0008]

As described above, according to the method of the present invention, a small amount of the water-soluble polymer compound is added to the asphalt emulsion obtained by using the amphipathic particles, and the resulting mixture is dried in a dryer such as a spray dryer. By drying, even asphalt with a high penetration can be pulverized. Hereinafter, the present invention will be described in more detail with reference to specific examples. In the examples, all parts are parts by weight, and straight asphalt has a penetration of 150-200.

[0009]

[Example] (Example 1) Calcium carbonate (average particle size
0.1 μm) 100 parts of acrylic acid and polyethylene glycol methacrylate were co-polymerized in a ratio of 1: 1 by a conventional method, and neutralized with ammonia to obtain an average molecular weight of 13,0.
1 part of the copolymer of 00 was added to 900 parts of dissolved water, and the mixture was thoroughly stirred with a disper to allow the resin composition to adhere to the calcium carbonate surface, then filtered with a filter press, dehydrated and dried by a conventional method. Then, amphipathic particles were produced. 30 parts of these particles are suspended in 100 parts of water, and the temperature is kept at 50 ° C. with sufficient stirring with a disper. On the other hand, straight asphalt
100 parts were heated to 150 ° C., the viscosity was lowered, and both were sent to the same amount and simultaneously passed through a Harrell homogenizer to emulsify them. A 5% polyvinyl alcohol aqueous solution was added to this emulsified liquid so as to be 3% with respect to the asphalt, and the mixture was dried with a spray dryer (manufactured by Okawara Kakoki Co., Ltd.) with sufficient stirring. In this case, the atomizer rotation speed is 25000 rotations /
Minutes, and the hot air temperature at the inlet was 150 ° C. The powder asphalt obtained was a black powder that was crushed by acupressure.

Example 2 Calcium carbonate (average particle size
0.5 μm) Add 100 parts of a condensate of dimer acid and polyamine (Fuji Kasei Kogyo Co., Ltd .: trade name tomide 296) to a solution of 60 parts of dichloromethane dissolved in 60 parts, and stir well, then heat the solvent It is distilled off to produce amphipathic particles. 30 parts of these particles are added to 100 parts of water, and the temperature is kept at 50 ° C while stirring with a disper. On the other hand, 100 parts of straight asphalt was heated to 150 ° C, and both were passed through a Harrell-type homogenizer at the same amount and mixed and emulsified. To this emulsion, 5% carboxymethyl cellulose aqueous solution was added in an amount of 4% with respect to asphalt, and the mixture was dried with a spray dryer in the same manner as in Example 1 while sufficiently stirring to obtain a powder. The obtained asphalt powder is a black powder that can be crushed by strong finger pressure.

(Example 3) 100 parts of calcium carbonate (average particle diameter 3 µm) was treated in the same manner as in Example 2 to produce amphiphilic particles. 30 parts of these particles are added to 100 parts of water, and the temperature is maintained at 50 ° C while stirring with a disper. On the other hand, 100 parts of straight asphalt was heated to 150 ° C, and both were passed through a Harrell homogenizer at the same amount and mixed at the same time to obtain an asphalt suspension. To this suspension, 5% aqueous polyvinyl alcohol solution was added so as to be 5% with respect to the asphalt, and with sufficient stirring, in the same manner as in Example 1,
It was dried by a spray dryer and pulverized. The obtained asphalt powder was larger than those in Examples 1 and 2 and had a strength such that it was not crushed by black finger pressure.

[0012]

From the above results, it was found that the asphalt powder can be produced by dispersing the asphalt using the amphiphilic particles, adding a small amount of the water-soluble polymer compound and drying. It was This makes it possible to rationalize the storage, packaging, transportation, etc. of asphalt, crush powder asphalt by heating or pressurization, and use it in the fields of conventional asphalt use, as well as utilizing the characteristics of powder asphalt. Expected to open up new applications.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isao Sekiguchi 2-26-9, Saint-Gaoka, Tama-shi, Tokyo (72) Inventor Yoshio Iwasaki 2-30-10 Sanno, Ota-ku, Tokyo

Claims (1)

[Claims] 1. An asphalt emulsion is obtained by stirring and mixing a suspension water of amphipathic particles in which a part of the surface of hydrophilic inorganic particles is coated with a lipophilic substance and asphalt having a low viscosity with heating, and then the asphalt emulsion. After adding 1% by weight or more of the water-soluble polymer compound to the asphalt,
A method for producing asphalt powder particles, which comprises spray drying.