JP2002003858A - Asphalt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce asphalt which causes less smoking upon production of an asphalt mixture and upon transportion and use of asphalt, improves working atmosphere, and can minimize air pollution. SOLUTION: The asphalt has an evaporation loss of 90 mass ppm or less at 180 deg.C under normal pressures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to asphalt used for road pavement, civil engineering, construction, and the like, and more particularly, to asphalt which generates less smoke when heated during production of asphalt mixture, asphalt transportation and use. About.

[0002]

2. Description of the Related Art Asphalt is widely used in the fields of road pavement materials, roofing materials, sealing materials, adhesives, etc. because of its excellent adhesiveness, workability, and waterproofness.

[0003] Since this asphalt is solid at ordinary temperature and is difficult to handle, the asphalt is usually heated and used when producing an asphalt mixture, transporting and using the asphalt. For example, during the production of asphalt mixture, which is a mixture of asphalt and aggregate, and when loading asphalt on a lorry, asphalt is handled at a temperature of about 140 to 200 ° C., even during road pavement construction, to improve workability. The work is performed while the asphalt mixture is kept at 100 to 160C. In addition, in recent years, demand for modified asphalt in which asphalt is mixed with a modifier such as rubber and thermoplastic elastomer to increase the life of road pavement has been increasing. Also,
It is carried out at a temperature at the time of asphalt mixture production or higher.

[0004] Therefore, there is a problem that asphalt heating generates smoke in an area where an asphalt plant is located, an asphalt loading facility on a lorry, or near a road pavement site. This deteriorates the working environment and is a problem from the viewpoint of air pollution.

[0005] As a method for evaluating light components in asphalt, a test for evaporative mass change rate is specified in JIS K2207. In this test, asphalt placed in a sample container for penetration test was heated at 163 ° C. for 5 hours,
The mass before and after the heating is compared. However, in this method, two reactions occur at the same time: a reaction in which asphalt is oxidized by heating in air to increase the mass due to heating, and a phenomenon in which the mass decreases due to the evaporation of light components. Is always the result of the mass increase due to oxidation and the mass decrease due to evaporation, and this result alone could not be used to evaluate asphalt with low smoke emission.

On the other hand, there has been proposed a method of obtaining asphalt for waterproofing work with less smoke by heating in a temperature range of 200 ° C. to 300 ° C. and quantifying the amount of smoke generated at that time (JP-A-11-181291). No.). In addition, low-smoke waterproofing asphalt for waterproofing construction has been proposed by various manufacturing methods (Japanese Patent Application Laid-Open Nos. Hei 6-009878 and 7-1).
No. 96922). However, these are about 240-26
The present invention relates to blown asphalt for waterproofing work which is heated and melted at 0 ° C.

[0007] Therefore, it has been an important issue to develop a technique for suppressing the amount of smoke generated in general asphalt such as straight asphalt.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made from the above-mentioned viewpoints, and produces less smoke during transportation and use of asphalt such as production of asphalt mixture, loading of asphalt and construction of road pavement, etc. An object is to provide asphalt that can improve and reduce air pollution.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, the amount of evaporation of asphalt under specific conditions is correlated with the amount of smoke (the degree of smoke). The present invention has been completed, and the present invention has been completed. That is, the gist of the present invention is as follows. [1] Asphalt having an evaporation amount at 180 ° C. of 90 mass ppm or less under normal pressure. [2] The above-mentioned [1] whose evaporation amount is 70 mass ppm or less.
Asphalt according to the above. [3] The above-mentioned [1], wherein the amount of evaporation is 40 mass ppm or less.
Or the asphalt according to [2]. [4] The asphalt according to any of [1] to [3], wherein the evaporation amount is measured by blowing an inert gas as an accompanying gas into the sample asphalt. [5] The asphalt according to any of [1] to [4], wherein the asphalt is a straight asphalt having a penetration of 40 to 100.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The asphalt of the present invention is an asphalt having an evaporation amount of 90 mass ppm or less at 180 ° C. under normal pressure. 90 mass p under the above conditions
Asphalt exceeding pm emits a lot of smoke when handled,
Causes work environment and air pollution problems. The evaporation amount is more preferably 70 mass ppm or less, particularly preferably 40 mass ppm or less.

The method of measuring the amount of evaporation referred to here is under normal pressure,
It measures the amount of evaporation which is a light component obtained when heated to 180 ° C. This is because the amount of evaporation under such conditions correlates with the amount of smoke generated during actual asphalt handling.

As a preferred method of measuring the amount of evaporation in the present invention, for example, a method using an evaporation amount measuring apparatus shown in FIG. 1 can be mentioned. In FIG. 1, 1 is a thermostat, 2 is a sample container, 3 is a sample asphalt, 4 is an accompanying gas source, 5 is an accompanying gas flow meter, 6 is an accompanying gas line, 7 is an adsorbent, and 8 is an evaporant recovery line. Show. As the first constant temperature bath, a constant temperature air bath is usually used. As the second sample container, it is convenient to use a cylindrical heat-resistant glass container (for example, one having a diameter of 60 mm and a depth of 170 mm). An inert gas such as nitrogen or helium is used as the accompanying gas source of 4, and this gas is passed through the accompanying gas flow meter 5 and the accompanying gas line 6 to the sample container 2.
The sample is led to the sample asphalt 3 inside. Activated carbon or the like is used as the adsorbent 7, and adsorbs the light components collected by the evaporant collection line 8 located above the sample container 2.

Using such an evaporation amount measuring apparatus, the evaporation amount is measured as follows. First, a certain amount of the sample asphalt is collected in the sample container 2. It is placed in the thermostat 1, and the sample temperature is raised to 180 ° C. Further, the tip of the accompanying gas line 6 is set in the sample asphalt 3, and the gas flow from the accompanying gas source 4 is adjusted, and this gas is blown into the sample asphalt 3. Then, the light components generated during keeping at 180 ° C. for a certain period of time, for example, two hours, are adsorbed on the adsorbent 7 by the evaporant recovery line 8. Then, the light components adsorbed on the adsorbent 7 are quantified by, for example, gas chromatography, and the amount of evaporation can be obtained.

As described above, in the measurement of the amount of evaporation in the present invention, it is preferable that the measurement is performed by blowing the accompanying gas into the sample, whereby a stirring effect is given to the sample and the evaporation of light components is promoted. Therefore, the measurement can be performed in a short time, and the measurement accuracy is high. In addition, since an inert gas is used as the accompanying gas, oxidation of the sample asphalt can be prevented, and there is no possibility that the evaporation amount is erroneously measured, such as an increase or decrease of light components due to the oxidation reaction. The flow rate of such accompanying gas is not particularly limited, but is preferably in the range of 100 to 500 ml / (100 g · min) (100 to 500 ml / min per 100 g of sample), and is preferably in the range of 200 to 400 ml / (100 g · min). More preferably, there is.

The measurement time of the amount of evaporation (heating time at 180 ° C.) is preferably about 1 to 3 hours, and usually 2 hours. The asphalt of the present invention mainly targets straight asphalt. Straight asphalt includes so-called ordinary straight asphalt, bottom residue asphalt and asphalt without propane. The former bottom residue asphalt is obtained by distilling crude oil from atmospheric oil under normal pressure to obtain petroleum gas, gasoline, naphtha, kerosene, This is a bottom distillate obtained by distilling light oil etc. and further separating a lubricating oil fraction etc. by vacuum distillation. Propane deasphalted asphalt is a residual oil obtained by extracting a high-viscosity high-grade lubricating oil fraction (such as bright stock) from a vacuum distillation residual oil using a mixture of propane and butane as a solvent. Use the above asphalt alone or 2
Species or more can be arbitrarily mixed and used. Also,
Asphalt in which a suitable amount of blown asphalt that has been subjected to an oxidative polymerization reaction by blowing high-temperature air into straight asphalt may be used.

The modified asphalt is obtained by adding a modifier such as rubber, resin, thermoplastic elastomer or fiber to raw asphalt such as straight asphalt as a measure against rutting in summer and embrittlement in winter.

In the present invention, as described above, straight asphalt is mainly used, but this asphalt is used for road pavement, as a raw material for modified asphalt, and as a raw material for blown asphalt.

Further, the modified asphalt does not involve a reaction during the production as in the case of blown asphalt, and is produced only by mixing straight asphalt and a modifier, so that the present invention can be applied as it is.

The penetration of the asphalt to be used in the present invention is not particularly limited, but preferably 0 to 300, more preferably 40 to 200, and more preferably 40 to 100.
Is particularly preferred.

The method for obtaining the asphalt of the present invention is not particularly limited. For example, crude oil is distilled under normal pressure, the distillation bottom oil is distilled under reduced pressure, and the obtained vacuum distillation bottom oil is further distilled under reduced pressure. (Two-stage vacuum distillation method), or a method in which two or more asphalts are mixed to produce a target asphalt, using heavy oil as a cutback oil.

[0021]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Example 1 Middle East crude oil was distilled under normal pressure, and the obtained distillation column bottom oil was subjected to deep vacuum distillation (total pressure 5.1 kPa, raw material filling temperature 400 ° C.) to obtain straight asphalt.
The penetration of this asphalt was 90. [Example 2] Middle-stage crude oil was subjected to atmospheric distillation, and the resulting distillation column bottom oil was subjected to reduced-pressure distillation (total pressure 8.1 kPa, feed oil filling temperature 385 ° C), and a single-stage reduced-pressure distilled asphalt obtained. Further, this was mixed with propane deasphalted asphalt, which had undergone propane leaching, at 55:45 to obtain straight asphalt. The penetration of this asphalt was 69. Example 3 Middle Eastern crude was distilled under normal pressure, and the resulting distillation column bottom oil was distilled under reduced pressure (total pressure 8.1 kPa, feed oil filling temperature 385 ° C.), and further to depth reduced pressure distillation (total pressure 4 .4
(kPa, raw oil filling temperature: 405 ° C.) to obtain straight asphalt. The penetration of this asphalt was 66. [Examples 4 and 5] Among the mixed straight asphalts used in Example 2, one-stage vacuum distillation conditions under reduced pressure distillation production (straightness of vacuum, temperature and charge amount)
Was changed to obtain mixed straight asphalt having a penetration of 63 and 74, respectively. Example 6 Middle-east crude was distilled under normal pressure, and the distillation column bottom oil obtained was subjected to reduced-pressure distillation to obtain a single-stage vacuum-distilled straight asphalt. Then, a straight asphalt having a penetration of 77 was obtained. [Comparative Example 1] Among the mixed straight asphalts used in Example 2, the reduced pressure distillation conditions (pressure reduction, temperature and charge amount) at the time of producing the single-stage vacuum distillation straight asphalt were changed to obtain a mixed straight asphalt having a penetration of 72. I got [Comparative Examples 2 to 6] Conditions for vacuum distillation of a single-stage vacuum distilled straight asphalt obtained by subjecting Middle Eastern crude to atmospheric distillation and the resulting distillation column bottom oil to be subjected to vacuum distillation (degree of vacuum, temperature and charge amount). And the penetration is 61, 62, 7 respectively.
5, 73, 68 straight asphalts were obtained.

Each of the asphalts of Examples 1 to 6 and Comparative Examples 1 to 6 was evaluated by the following tests.
The results are shown in Table 1. [Evaporation amount measurement test] Using a measuring apparatus shown in FIG. 1, 50 g of sample asphalt, a sample temperature of 180 ° C., an evaporation time (light-weight adsorption time) of 2 hours, and nitrogen gas as an accompanying gas at a rate of 3 min.
Activated carbon was used as an adsorbent. [Smoke emission test when loading lorry] The smoke emission status when loading each of the above-mentioned straight asphalt from an asphalt filler port to a 10-t lorry for asphalt was visually observed and evaluated from a lorry hatch. The temperature of the straight asphalt during loading was controlled at 175 to 185 ° C.

Evaluation criteria ◎ Very small ○ Small △ Normal (Slightly small) × Many [Mass change after evaporation] According to the method described in JIS K2207.

[0024]

[Table 1]

As shown in the results in Table 1, the asbestos of Examples 1 to 6 has a small amount of evaporation (90 mass ppm or less),
Low smoke when loading lorries. In addition, the evaporation amount is 7
In the case of 0 ppm or less (Examples 1 to 3), particularly 40 ppm or less, the amount of smoke generated when loading a lorry is small (Example 1,
3). On the other hand, the amount of evaporation of the asbestos of Comparative Examples 1 to 6 was large, and the amount of smoke generated when loading the lorry was large. Further, in both the examples and the comparative examples, the mass change rate after the evaporation test was ± 0.05.
Small, no difference. This indicates that the evaporation rate of assalt cannot be evaluated from the mass change rate after evaporation.

[0026]

The asphalt of the present invention is an asphalt capable of improving the working environment and reducing air pollution when asphalt is loaded, when asphalt mixtures such as modified asphalt are produced, when road pavement is constructed, and the like.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an evaporation amount measuring device that can be used in the present invention.

[Explanation of symbols]

 Reference Signs List 1 constant temperature bath 2 sample container 3 sample asphalt 4 accompanying gas source 5 accompanying gas flow meter 6 accompanying gas line 7 adsorbent 8 evaporant recovery line

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4H058 DA14 FA40 GA32 HA03 HA20 HA22 HA25 HA30 4J002 AG001 GL00

Claims (5)

[Claims] 1. Evaporation amount at 180 ° C. under normal pressure is 9
Asphalt of 0 mass ppm or less. 2. The asphalt according to claim 1, wherein the amount of evaporation is 70 mass ppm or less. 3. The asphalt according to claim 1, wherein the amount of evaporation is 40 mass ppm or less. 4. The asphalt according to claim 1, wherein the amount of evaporation is measured by blowing an inert gas as an accompanying gas into the sample asphalt. 5. The asphalt according to claim 1, wherein the asphalt is a straight asphalt having a penetration of 40 to 100.