JPH0625536A - Production of new asphalt emulsion - Google Patents

Abstract

PURPOSE:To obtain a new asphalt emulsion, good in adhesion, drying properties and water resistance and useful for road paving, waterproofing work, etc., by emulsifying asphalt with a specific amount of amphiphatic particles in which the surfaces of hydrophilic inorganic particles are partially coated with a lipophilic substance. CONSTITUTION:This asphalt emulsion is obtained by adding hydrophilic inorganic particles such as silicon dioxide or a carbonate and a silicate of aluminum, calcium or magnesium to a solution of a lipophilic substance such as a silane compound, a titanate-based coupling agent, an oil-soluble polyamine condensate, an acrylic acid-based polymer or copolymers thereof in an organic solvent, sufficiently stirring the resultant mixture with a disperser, then heating and distilling away the solvent, providing amphiphatic particles in which the surfaces of the hydrophilic inorganic particles are partially coated with the lipophilic substance and the particle diameter is <=0.6mum, subsequently dispersing the resultant particles in an amount of 25-45% based on asphalt in water, mixing the obtained dispersion with the asphalt thermally melted at 150 deg.C, mixing and emulsifying the prepared mixture in a homogenizer. This emulsion is excellent in adhesion, drying properties and water, resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for emulsifying asphalt using an inorganic powder having both hydrophilicity and lipophilicity, and particularly to a method for producing an asphalt emulsion excellent in adhesion, drying property and water resistance. Of the proposal.

[0002]

2. Description of the Related Art Asphalt (bituminous material) is a material that has been used in many fields since ancient times because it was naturally produced. However, with the expansion of petroleum utilization, what is currently commonly used is: Almost petroleum asphalt, and one of the materials that can be secured in large quantities. By taking advantage of the cheapness of these asphalts and their characteristics such as adhesive strength, bonding strength, waterproofness, vibration control, rust prevention, and electrical insulation, road pavement, water conservancy construction, waterproof construction, waterproof paper, electrical insulation materials It is widely used in many fields such as various coating materials. Many types of products having different compositions and penetrability (hardness) called straight asphalt, blown asphalt, etc. are manufactured and supplied.

[0003]

These asphalts generally have a high softening point and are viscous liquids, semi-solids or solids at ordinary temperature, have no fluidity, and are heated or melted or softened by heating during use. It was necessary to make the viscosity suitable for work before use, which hindered the expansion of applications. There is a so-called asphalt emulsion in which asphalt is emulsified and suspended in water using an emulsifier in order to eliminate this defect and facilitate handling. When used for road pavement, waterproof revetment, roofing, paint, floor covering, etc. where asphalt is mainly used, aggregate such as crushed stone, sand, soil, or the surface of asphalt, cement, concrete, metal, etc. It is necessary to obtain sufficient binding during However, since the surface of the above substances is generally hydrophilic and many of them are negatively charged, the anionic emulsion obtained by using the anionic surfactant also has an electric repulsion, and these surfaces are also negatively charged. Asphalt adheres poorly to the surface, and asphalt re-emulsification may occur due to initial rainfall, long-term water immersion, etc.In order to improve this point, a cationic surfactant is used instead of an anionic surfactant to emulsify. However, the above problems have not been solved sufficiently.

[0004]

[Means for Solving the Problems] The present inventors have solved the above-mentioned problems, which are considered to be caused by forced emulsification by using a large amount of conventional surfactants, and further develop new applications. As a result of repeated research focusing on emulsifying asphalt using inorganic particles having hydrophilicity and lipophilicity (called amphipathic particles), the appropriate selection of amphiphilic particles, asphalt The present invention has been found to be effective and can be solved by adjusting the mixing ratio, the temperature, the emulsification conditions such as PH, and the selection of the emulsifying device.

The base material of the amphipathic substance used in the production method of the present invention is a hydrophilic inorganic particle, which has a water affinity and is hardly soluble or insoluble in water and is substantially soluble in water. Not included substances. 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, Examples thereof include hydroxides such as magnesium hydroxide, barium sulfate, and sulfates such as calcium sulfate. For the amphipathicization of these inorganic particle materials, a single species is usually used advantageously, but two or more species may be used in combination, or after amphiphilization of each, two or more species are mixed. It can also be used. However, considering the unit price and the particle size that can be industrially provided,
Practically particularly preferable materials are silicon dioxide, calcium carbonate, talc and the like.

The particle size of the amphipathic particles for obtaining the asphalt emulsion according to the present invention is as small as possible in order to reduce the particle size of the dispersed asphalt in the asphalt emulsion to be formed. It is necessary to use particles of 1 μm or less, preferably 0.6 μm or less. To make these fine particles amphipathic, they can be produced by making particles having a larger particle size lipophilic and then grinding them, but fine particles such as 1 μm or less as a raw material inorganic material An amphipathic substance can be easily obtained by partially making the surface lipophilic by using. Further, as the lipophilic substance used for surface modification of the hydrophilic inorganic material, it is important that it is a substance that fixedly forms a hydrophobic portion on the surface of the inorganic particles, such as fatty acid, wax and fats and oils. As such, substances that migrate after adhesion are essentially unusable. Examples of the lipophilic substance preferably used in the method of the present invention include silane compounds, titanate-based coupling agents, oil-soluble polyamine condensates, acrylic acid-based polymers or copolymers thereof, and the like. They may be used as a single substance or may be used in combination of two or more components.

As the particle size of the amphipathic particles increases, the particle size of the emulsion also increases, and it is recognized that the stability with time and the film performance of the emulsion after film formation tend to deteriorate accordingly. Therefore, the particle size is preferably 0.6 μm or less. Using such amphipathic particles, the amphipathic particles used in emulsifying the asphalt are closely adhered to the surface of the generated asphalt particles to form an inorganic layer on the outside of the asphalt particles, and fused. To stabilize the emulsion particles. Therefore, it is important to cover the surface of the generated asphalt particles densely, and it is preferable that the amount of amphiphilic particles relative to the asphalt is 20% or more.

As the amount of powder added to the asphalt increases, the viscosity of the emulsion increases, making it difficult to handle and increasing the mechanical load, which is economically disadvantageous. Therefore, it is preferably 45% or less. Further, as a mechanical device for emulsifying asphalt with amphipathic particles, a stirring device having a structure with as large a shearing force as possible is desirable, and a Harrel homogenizer or the like is suitable. Upon emulsification, the asphalt is heated so as to be suitable for stirring to be sufficiently softened, and the water is heated to a temperature at which it does not boil even when mixed with the heated asphalt. It is desirable to set the temperature of the mixture of water and asphalt as high as possible.

[0009]

As described above, according to the method of the present invention, the amphipathic substance obtained by proper selection of the type of raw material inorganic particles, the particle size, the type of lipophilic surface modifier, etc., with respect to asphalt With a proper amount of addition, a soapless emulsion can be substantially produced. Hereinafter, the present invention will be described in more detail with reference to specific examples. The straight asphalt used below has a penetration of 150-200.

[0010]

【Example】

(Example 1) Light calcium carbonate (average particle size 0.1 μm)
m) Add 100 parts by weight of a condensate of dimer acid and polyamines (Fuji Kasei Kogyo Co., Ltd., trade name: Thomaide 296) to a solution prepared by dissolving 60 parts by weight of dichlormethane, and thoroughly stir with a disper. Then, the solvent is heated and evaporated to produce amphiphilic particles. 25, 30, 40 parts by weight of the particles are added to 100 parts by weight of water, and the temperature is kept at 50 ° C. with sufficient stirring with a disper. On the other hand, 100 parts by weight of straight asphalt was melted by heating to 150 ° C, and both of them were simultaneously passed through a Harrell type homogenizer and mixed and emulsified.

Example 2 100 parts by weight of light calcium carbonate (average particle size 0.1 μm) were copolymerized by a conventional method at a ratio of 1: 1 parts by weight of acrylic acid and polyethylene glycol methacrylate, and neutralized with ammonia. Water in which 1 part by weight of the obtained copolymer having an average molecular weight of 13000 was dissolved
It was added to 900 parts by weight and sufficiently stirred with a disper to allow the resin composition to be adsorbed on the surface of calcium carbonate, filtered and dehydrated with a centrifugal dehydrator, and dried by a conventional method to produce amphiphilic particles. Add 25, 30, and 40 parts by weight of these particles to 100 parts by weight of water, and while stirring well with a disper, keep the temperature at 50 ° C.
Keep on. On the other hand, 100 parts by weight of straight asphalt 1
The mixture was heated to 50 ° C. and melted, and both were passed through a Harrell homogenizer at the same amount and mixed and emulsified.

(Example 3) Calcium carbonate (average particle size
0.3 μm) 100 parts by weight of a condensate of dimer acid and polyamine (Tomide 296) 0.8 parts by weight of dichlormethane 60
Add to the solution dissolved in 1 part by weight and stir well with a disper. After that, the solvent is heated and distilled off to produce amphiphilic particles. 100 parts by weight of water is added to 40 parts by weight of the particles, and the temperature is kept at 50 ° C. while sufficiently stirring with a disper. On the other hand, 100 parts by weight of straight asphalt was heated to 150 ° C. and melted, and both of them were simultaneously passed through a Harrell type homogenizer to be mixed and emulsified.

(Example 4) Calcium carbonate (average particle size
0.6 μm) 100 parts by weight of a condensate of dimer acid and polyamine (tomide 296) 0.6 parts by weight of dichlormethane 60
Add to the solution dissolved in 1 part by weight and stir well with a disper. After that, the solvent was heated and evaporated to firmly attach the condensate to the surface of the calcium carbonate to produce amphiphilic particles. 100 parts by weight of water is added to 40 parts by weight of the particles, and the temperature is kept at 50 ° C. while sufficiently stirring with a disper. On the other hand, 100 parts by weight of straight asphalt is heated and melted at 150 ° C,
Both of them were sent to the same amount at the same time through a Harrell homogenizer, and mixed and emulsified.

(Example 5) Silica powder (average particle size 0.5
μm) 100 parts by weight is added to a solution prepared by dissolving 1 part by weight of TOMIDE 296 in 60 parts by weight of dichloromethane and thoroughly stirred with a disper. After that, the solvent was heated and distilled off to firmly adhere the condensate to the surface of the silica powder to produce amphiphilic particles. 100 parts by weight of water is added to 35 and 40 parts by weight of the particles, and the temperature is kept at 50 ° C. while sufficiently stirring with a disper. On the other hand, 100 parts by weight of straight asphalt was heated to 150 ° C., and both were passed through a Harrell homogenizer at the same amount.

(Comparative Example 1) The same treatment as in Example 1 was carried out except that the amount of the amphiphilic particles of Example 1 added was 15, 20 parts by weight.

(Comparative Example 2) The same treatment as in Example 2 was carried out except that the amount of the amphiphilic particles of Example 2 added was 15, 20 parts by weight.

(Comparative Example 3) The same treatment as in Example 3 was carried out except that the amount of the amphiphilic particles of Example 3 added was 20, 25, and 30 parts by weight.

(Comparative Example 4) The treatment was carried out in the same manner as in Example 4 except that the amount of the amphiphilic particles of Example 4 added was 20, 25, 30, 35 parts by weight.

(Comparative Example 5) The same treatment as in Example 5 was carried out except that the amount of the amphiphilic particles of Example 5 added was 20, 25, 30 and parts by weight.

Comparative Example 6 Calcium carbonate (average particle size
1.2 μm) Add 100 parts by weight of Thomaide 296 0.5 parts by weight to a solution prepared by dissolving 60 parts by weight of dichloromethane, and stir with a disper. After that, the solvent was heated and distilled off to firmly attach the condensate to the surface of the calcium carbonate to produce amphiphilic particles. Water in 20, 30, 35, 40 parts by weight of these particles 1
Add 00 parts by weight and keep the temperature at 50 ° C while stirring well with a disper. On the other hand, 100 parts by weight of straight asphalt was heated to 150 ° C., and both of them were sent to the same amount at the same time and passed through a Harrell homogenizer to check the emulsification status.

Comparative Example 7 Silica powder (average particle size 1 μm
m) Add 100 parts by weight of tomide 296 0.5 parts by weight to a solution prepared by dissolving 60 parts by weight of dichloromethane and stir well with a disper. After that, the solvent was heated and distilled off to firmly adhere the condensate to the surface of the silica to produce amphiphilic particles.
Add 100 parts by weight of water to 20, 25, 30, 40 parts by weight of these particles,
Keep the temperature at 50 ° C while stirring well with a disper. On the other hand, 100 parts by weight of straight asphalt was heated to 150 ° C., and both were passed through a Harrell homogenizer at the same amount. The above results are summarized in Table 1.

[0022]

[Table 1]

Note 1) The emulsified state was judged as ◯ when the spherical asphalt particles were dispersed in water and passed through a 2 m / m sieve and there was no residue. Note 2) Stability of emulsion Put 100 ml of emulsion in a 100 ml measuring cylinder,
The state of separation of the aqueous layer was observed when it was left in a room at 20 ° C. for 7 days, and when it was 5% or less, it was marked as ◯. Note 3) Adhesion degree According to the JIS K 2208 adhesion degree test method. Note 4) Initial water resistance (rubbing test) As a base plate, use a straight plate that has been treated with an epoxy solvent-based paint to eliminate absorption, and apply a wet film thickness of 2 m / m on this straight plate at regular intervals. A drop of water was dropped on this coating film, and the time until it was strongly rubbed with a fingertip and re-emulsification was stopped was measured.

Example of Measurement of Physical Properties Using a soapless emulsion obtained by using amphiphilic particles as shown in the above examples, its vibration damping property was measured. The sample was placed on an aluminum plate with a length of 275 mm, a width of 10 mm, and a thickness of 1 mm to a thickness of 2 mm, and the loss coefficient measurement system (FFT SA-74A manufactured by Rion Co., Ltd.) was used to measure by the central vibration method (measurement frequency 12.5-2KHz). The physical properties of the damping material used are as follows.

[0025]

[Table 2]

Here, the sample is 275 mm in length, 100 mm in width and 1 in thickness.
mm aluminum plate Sample is the amphiphilic particles of Example 1 against asphalt 30%
Film thickness 2 made from asphalt emulsion obtained by using
The coating film of mm is a coating film made from a conventional asphalt emulsion and having a film thickness of 2 mm. As can be seen from FIG. 1, a damping material such as the sample is mounted in the temperature-loss coefficient as compared with the aluminum alone of the sample. However, the loss factor is much better. The samples of the present invention exhibited even better vibration damping properties than conventional asphalt emulsions. In the temperature-Young's modulus relationship of FIG. 2, it is shown that the sample of the present invention follows the penetrability well even though it is harder than the sample using the conventional asphalt emulsion.

[0027]

EFFECTS OF THE INVENTION From the above results, by emulsifying asphalt using particles with a small particle size obtained by modifying the surface of hydrophilic inorganic particles, an emulsion having excellent adhesion to aggregates and dryness can be produced. I found that I could do it. These asphalt emulsions are essentially soapless, and it is expected that new fields of application will be cultivated in addition to the conventional fields of use of asphalt.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between temperature and loss coefficient for samples 1 to.

FIG. 2 is a graph showing the relationship between the temperature and Young's modulus of Samples.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Tada 1-1-618 Nagata Minamidai, Minami-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Isao Sekiguchi 2-26-9, Kiyogaoka, Tama-shi, Tokyo (72) Inventor Yoshio Iwasaki 2-30-10 Sanno, Ota-ku, Tokyo

Claims (3)

[Claims] 1. A method for emulsifying an asphalt by using 25 to 45% of an amphipathic particle of 0.6 μm or less in which a part of the surface of a hydrophilic inorganic particle is coated with a lipophilic substance, based on the asphalt. A method for producing a characteristic asphalt emulsion. 2. The method according to claim 1, wherein the hydrophilic inorganic particles are selected from the group consisting of silicon dioxide, or carbonates and silicates of aluminum, calcium and magnesium. 3. An amphiphilic particle selected from the group consisting of a silane compound, a titanate-based coupling agent, an oil-soluble polyamine condensate, an acrylic acid-based polymer or a copolymer thereof, and the like is used as the lipophilic substance. The manufacturing method according to claim 1.