JP4856500B2 - Asphalt binder - Google Patents

Description

  The present invention relates to an asphalt binder added to an asphalt composition in order to adjust hardness and aromatic content, and more particularly to an asphalt binder suitable for a softening agent for reclaimed asphalt, rubber extension oil, rubber compounding oil, and the like.

  In recent years, the reuse of asphalt pavement waste has been promoted. Generally, asphalt pavement waste has deteriorated and hardened asphalt components, so that it can ensure sufficient penetration and elongation as it is. However, there was a problem that cracks occurred early in the reused pavement. In addition, it is known that the aromatic content in asphalt decreases due to pavement degradation (Tomoji Tonishi, “Study on physical and scientific properties of modified asphalt”, Civil Engineering Research Center, 1994. Outline of Researcher Report, June 1995, pp.167-170, Daisaku Tateishi, "Study on Physical and Scientific Properties of Modified Asphalt", Outline of Researcher Report of Researcher of Civil Engineering Research Center 1994 , June 1996, p.229-232), when reusing asphalt pavement waste, conventionally, highly aromatic mineral oil such as extract, animal and vegetable oil additives or pitch to supplement the aromatic content It is softened by adding a system additive or the like. Among these asphalt regeneration additives, especially high aromatic mineral oil, the asphalt component in the asphalt pavement waste deteriorated by the addition is brought closer to the composition of asphalt that does not use asphalt pavement waste, that is, new asphalt. Therefore, the flexibility and flexibility of the reclaimed pavement are improved, and it is effective for ensuring in-service performance (particularly difficult to generate cracks). However, these additives for regenerating asphalt have a problem of poor workability due to poor fluidity at room temperature (about 25 ° C.).

Thus, conventionally, additives for asphalt regeneration have been proposed in which the kinematic viscosity at normal temperature is reduced to improve workability during asphalt regeneration (see, for example, Patent Documents 1 to 6). Patent Document 1 discloses asphalt made of mineral oil having an aromatic content of 7 to 35%, a pour point of −5 ° C. or less, a kinematic viscosity at a temperature of 40 ° C. of 30 to 500 mm ² / sec, and a flash point of 230 ° C. or more. An additive for reclaiming pavement waste is disclosed, and examples thereof include a paraffin-based dewaxing lubricating oil, a mixture of a paraffin-based dewaxing lubricating oil and a naphthenic extract, and the like. Patent Document 2 discloses an additive for reclaimed asphalt made of extract oil having a kinematic viscosity at 40 ° C. of 600 to 2000 mm ² / sec and an aniline point of 35 ° C. or less.

Further, Patent Document 3 is a composition obtained by blending mineral oil and fats and oils having a kinematic viscosity at 40 ° C. of 300 to 900 mm ² / sec and a polycyclic aromatic content of less than 3% by mass. An asphalt regeneration additive composition having a kinematic viscosity at 40 ° C. at 40 to 400 mm ² / sec, a polycyclic aromatic content of less than 3% by mass, and a flash point of 220 ° C. or higher is disclosed. Furthermore, Patent Documents 4 and 5 are compositions obtained by blending a mineral oil having a kinematic viscosity at 60 ° C. of 100 to 1000 mm ² / sec and an oil or fatty acid alkyl ester compound, at 60 ° C. An asphalt regeneration additive composition having a kinematic viscosity of 20 to 300 mm ² / sec and a flash point of 210 ° C. or 220 ° C. or higher is disclosed. Furthermore, in Patent Document 6, the kinematic viscosity at 60 ° C. is 30 to 200 mm ² / sec, the polycyclic aromatic content is less than 3% by mass, the flash point is 220 ° C. or higher, the aromatic content is 10 to 20%, An asphalt regeneration additive composition having an initial boiling point by distillation of 280 ° C. or higher is disclosed.

JP-A-2-91303 JP-A-8-333515 JP 2005-154464 A JP 2005-154465 A JP 2005-154467 A JP 2005-154469 A

  However, the above-described prior art has the following problems. The asphalt regeneration additive described in the above-mentioned Patent Documents 1 to 6 reduces the kinematic viscosity by reducing the aromatic content and ensures fluidity at room temperature. Since the aromatic content of pavement waste material is reduced due to deterioration, when an additive for regenerating asphalt having a low aromatic content as described in Patent Documents 1 to 6 is used, the aroma in the entire regenerated asphalt composition There are fewer tribes. As a result, there is a problem that the composition of the regenerated asphalt composition cannot be brought close to the composition of the new asphalt composition, and the flexibility and flexibility in pavement after construction are reduced, and cracks are generated at an early stage.

  The present invention has been devised in view of the above-described problems, and provides an asphalt binder with good workability by improving fluidity at room temperature without reducing the aromatic content. Objective.

  The asphalt binder according to the present invention contains asphalt: 0.5 to 20.0% by mass, the remainder is composed of petroleum solvent extracted oil, the aromatic content is 70.0% by mass or more, and at 25 ° C. The complex elastic modulus at 0.1 rad / sec is 10.0 Pa or less.

  In the present invention, since the complex elastic modulus at 25 deg. C at 0.1 rad / sec is 10.0 Pa or less, the fluidity at room temperature is excellent, and the workability is improved compared to conventional additives. be able to. Moreover, since the aromatic content is 70.0% by mass or more, when used as an additive for asphalt regeneration, the composition of the regenerated asphalt composition can be brought close to the composition of the new asphalt composition, and the pavement is bent. And flexibility can be improved. That is, by using the asphalt binder of the present invention, a regenerated asphalt composition having characteristics equivalent to those of an asphalt composition not using asphalt pavement waste material can be obtained.

  Further, the asphalt is a solvent-deprived asphalt, straight asphalt, blown asphalt or a mixture of two or more of these asphalts, and the asphaltene content is preferably 40.0% by mass or less. Thereby, the workability | operativity (fluidity | liquidity) in the normal temperature of an asphalt binder can be improved, without diluting the aromatic component contained in petroleum solvent extraction oil. Further, since the blending amount of these asphalts is set to a certain amount or less (20.0% by mass or less), a significant increase in the amount of asphaltene in the asphalt composition is suppressed, and rubber such as SBS (styrene-butadiene-styrene) is suppressed. And the solubility can be improved.

  Furthermore, the asphalt binder of the present invention preferably has a flash point of 250 ° C. or higher. This increases the safety of the asphalt bander and facilitates handling.

  According to the present invention, an appropriate amount of asphalt is mixed with petroleum solvent extracted oil, the aromatic content is 70.0% by mass or more, and the complex elastic modulus at 0.1 rad / sec at 25 ° C. is 10.0 Pa or less. Therefore, fluidity at room temperature can be improved without reducing the aromatic content, and even when used as an asphalt regeneration additive, workability is improved without degrading the properties of paving materials. Can be made.

  Hereinafter, the best mode for carrying out the present invention will be described in detail. In order to improve the fluidity of the asphalt binder used as a softening agent for reclaimed asphalt, rubber extension oil, rubber compounding oil, etc., and to improve workability, specifically, drums and pail cans, etc. In order to facilitate the outflow from the storage container and the transfer by the pump (especially the flow in the piping at the start-up), intensive experimental research was conducted. As a result, under such conditions of use, particularly when starting to flow, a very slow force (gravity if it flows out of the storage container, pressure if it is transferred by a pump) acts on the asphalt binder. From 25 ° C., the complex elastic modulus at a slow loading frequency of 0.1 rad / sec (0.0159 Hz) is measured, and if the value is 10.0 Pa or less, it is obtained in these operations. It was found that the fluidity can be obtained. Furthermore, when asphalt is added at a specific rate to petroleum-based solvent extract oil that has been used as an additive for asphalt in the past, the complex elastic modulus at 25 deg. And found the present invention.

  That is, the asphalt binder of the present invention is a mixture of asphalt: 0.5 to 20.0% by mass and petroleum solvent extracted oil: 80.0 to 99.5% by mass. And the aromatic content in the whole additive is 70.0 mass% or more, and the complex elastic modulus in 0.1 rad / sec in 25 degreeC is 10.0 Pa or less.

  Hereinafter, the reason for the numerical limitation in the asphalt binder of the present invention will be described.

Asphalt: 0.5-20.0% by mass
Asphalt is added to improve fluidity at room temperature and to improve compatibility with the asphalt composition. However, when the asphalt content is less than 0.5% by mass, these effects cannot be obtained. On the other hand, when the asphalt content exceeds 20.0% by mass, the ratio of petroleum-based solvent extracted oil decreases, and it hardly flows at room temperature, so that workability is lowered. Furthermore, the amount of asphaltenes is increased, and the compatibility with rubber such as SBS may be lowered. Therefore, asphalt content shall be 0.5-20.0 mass%.

  Examples of the asphalt in the present invention include straight asphalt (see JIS K 2207), solvent deasphalted asphalt (see “New Petroleum Dictionary”, edited by the Japan Petroleum Institute, 1982, p. 308), and blown asphalt (JIS K 2207). Or a mixture in which two or more of these are mixed, and an asphaltene content of 40.0% by mass or less can be used. Since these asphalts are all readily available, they are suitable for use in, for example, the construction of a social infrastructure such as roads, and the asphalt composition is not diluted without diluting the aromatics contained in petroleum-based solvent extracted oil. The workability (fluidity) of an object at room temperature can be improved. However, if the amount of asphaltene in the asphalt exceeds 40.0% by mass, compatibility with rubber such as SBS is lowered. Therefore, it is desirable to use asphalt having an asphaltene content of 40.0% by mass or less. Thereby, the total amount of asphaltenes in the asphalt binder can be suppressed to 10.0% by mass or less. In general, asphalt contains at least about 5.0% by mass of asphaltene.

Petroleum solvent extraction oil: 80.0-99.5 mass%
Petroleum-based solvent extract oil is an oil extracted in the process of solvent extraction when producing lubricating oil from crude oil, and is an oily substance rich in aromatics and naphthenes ("until petroleum products are made", FIG. 6-1 “General Lubricating Oil Production Process”, published by Japan Petroleum Federation, November 1971, p. 99, and “New Petroleum Dictionary”, Petroleum Society, 1982, p. 304). This petroleum solvent extracted oil is a component that acts as a softener when added to an asphalt composition, has a boiling point of 350 ° C. or higher, a viscosity at 100 ° C. of 5 to 100 mPa · sec, and a flash point of 250 ° C. or higher. Thus, the aromatic content is desirably 75.0% by mass or more. Examples of such petroleum solvent extraction oil include bright stock solvent extractables extracted with a solvent such as phenol, N-methylpyrrolidone, liquid sulfur dioxide, and furfural in a crude oil refining process. When the content of the petroleum solvent extracted oil is less than 80.0% by mass, the fluidity is lowered and good workability cannot be obtained. On the other hand, when the content of the petroleum-based solvent extraction oil exceeds 99.5% by mass, the fluidity is lowered again and good workability cannot be obtained. Therefore, the content of the petroleum solvent extracted oil is set to 80.0 to 99.5% by mass.

Aromatic content: 70.0% by mass or more The aromatic content affects the properties of the pavement material, particularly the flexibility and flexibility of the pavement. As described above, since the asphalt pavement waste material has reduced aromatic components due to deterioration, when used as a raw material for an asphalt composition, it is necessary to increase the aromatic content in the additive. Specifically, when the aromatic content of the added asphalt binder is less than 70.0% by mass, the aromatic content cannot be sufficiently increased when mixed with deteriorated asphalt (asphalt pavement waste material). That is, since the composition of the regenerated asphalt composition cannot be brought close to the composition of the new asphalt composition, it becomes difficult to improve the flexibility and flexibility of the pavement, and cracks occur early after use. Therefore, in the asphalt binder of this invention, aromatic content shall be 70.0 mass% or more. In addition, aromatic content prescribed | regulated by this invention is a dichloromethane (95 mass%) from the residual component after extracting and developing an asphalt binder with n-hexane and toluene, for example using thin layer chromatography. A component extracted with a mixed solution of methanol and methanol (5% by mass) can be obtained by developing a chromatogram and detecting it using a hydrogen flame.

Complex elastic modulus at 25 deg. C at 0.1 rad / sec: 10.0 Pa or less As described above, the purpose of improving workability in the present invention is work in which a slow force acts at room temperature. Therefore, it is necessary to improve the fluidity by lowering the complex elastic modulus at 25 deg. Specifically, when the complex elastic modulus at 25 deg. C at 0.1 rad / sec exceeds 10.0 Pa, it hardly flows at room temperature, so that the outflow from the storage container and the workability at the time of pump transfer are reduced. Therefore, in the asphalt binder of the present invention, the complex elastic modulus at 0.1 rad / sec at 25 ° C. is set to 10.0 Pa or less.

The complex elastic modulus G ^* defined in the present invention can be measured with a dynamic viscoelasticity tester. FIG. 1 is a perspective view schematically showing a measurement unit of a dynamic viscoelasticity tester. Specifically, as shown in FIG. 1, an asphalt binder 1 is sandwiched between two parallel disks 2 a and 2 b, a sine wave distortion of a predetermined frequency is applied to one disk 2 a, and the other through the asphalt binder 1. The sinusoidal stress σ transmitted to the disk 2b is measured. The measurement conditions at that time are such that the diameter of the disks 2a and 2b is 40 mm, the thickness of the asphalt binder 1 is 1 mm, and the strain is 10%. And based on the measurement result, complex elastic modulus G ^* is calculated | required from following Numerical formula (1). Here, γ in the following mathematical formula (1) is the maximum strain applied to the disk 2a.

  In addition, although the invention which prescribed | regulated the complex elastic modulus of asphalt composition is disclosed by Unexamined-Japanese-Patent No. 2000-186211, this invention aims at ensuring elongation at the time of reusing asphalt pavement waste material. The complex elastic modulus at 10 rad / second (1.59 Hz) at 15 ° C. is specified. That is, since the purpose is different from that of the present invention, the measurement conditions of the complex elastic modulus are different. In general, an asphalt composition and an asphalt binder added to the asphalt composition have different behaviors when the loading frequency at the time of measurement is different. Therefore, just because the complex elastic modulus at 10 rad / second is low, 0.1 rad / s The complex modulus in seconds is not necessarily low. That is, as in the present invention, in order to improve the fluidity in a work in which a slow force is applied, the loading frequency of 10 rad / sec is too fast, and the loading frequency is as low as 0.1 rad / sec. It is necessary to evaluate the measured complex elastic modulus.

  The asphalt binder of the present invention preferably has a flash point of 250 ° C. or higher. Thereby, the safety of the asphalt bander is increased, and the use and storage are facilitated, so that the workability can be further improved.

  As described above, in the asphalt binder of the present invention, the complex elastic modulus at 25 deg. C at 0.1 rad / sec is 10.0 Pa or less, so that it has excellent fluidity at room temperature and flows out of the storage container. In addition, the workability in the work where a slow force such as pump transfer is applied can be improved. Moreover, since the asphalt binder of the present invention has an aromatic content as high as 70.0% by mass or more as compared with the conventional asphalt regeneration additive, even when used as an asphalt regeneration additive, the flexibility of pavement. In addition, the flexibility is improved, and characteristics equivalent to those obtained when a new asphalt composition not using asphalt pavement waste is used can be obtained.

  In addition, the asphalt binder of this invention can be used not only as an additive for asphalt regeneration mentioned above but also as a softening agent for a new asphalt composition that does not use asphalt pavement waste. Moreover, since the asphalt binder of the present invention has a high aromatic content and excellent compatibility with styrene, the SBS polymer (styrene-butadiene-styrene-block used as an asphalt modifier (reinforcing material) is used. It can also be used as an extending oil such as a copolymer.

Hereinafter, the effects of the present invention will be specifically described with reference to Examples and Comparative Examples. In this example, petroleum-based solvent extracted oil, and historical asphalt, straight asphalt or a mixture thereof, or blown asphalt were mixed at a ratio shown in Table 1 below using a propeller mixer. A comparative asphalt binder was prepared. The mixing conditions at that time were a mixing temperature of 170 ° C., a mixing time of 30 minutes, and a mixer rotation speed of 3000 times / minute. In this example, the petroleum solvent extracted oil has a viscosity at 100 ° C. of 0.060 Pa · sec, a density at 15 ° C. of 974.2 kg / m ³ , a flash point of 325 ° C., and an aromatic content of 80. 7% by mass and 0.9% by mass of asphaltene were used. As solvent deasphalted asphalt, the penetration at 25 ° C. is 8 (1/10 mm), the softening point is 66.5 ° C., the density at 15 ° C. is 1028 kg / m ³ , the flash point is 352 ° C., and the aromatic content is 61 0.1% by mass and an asphaltene content of 14.0% by mass were used. As straight asphalt, the penetration at 25 ° C. is 62 (1/10 mm), the softening point is 48.0 ° C., the density at 15 ° C. is 1033 kg / m ³ , the flash point is 360 ° C., and the aromatic content is 47.7. A material having a mass% and an asphaltene content of 17.8% by mass was used. As blown asphalt, the penetration at 25 ° C. is 34 (1/10 mm), the softening point is 102.0 ° C., the density at 15 ° C. is 1035 kg / m ³ , the flash point is 356 ° C., and the aromatic content is 38.3. A material having a mass% and asphaltene content of 31.0% by mass was used. As the lubricating oil, the density at 15 ° C. is 884.6 kg / m ³ , the flash point is 246 ° C., the kinematic viscosity at 100 ° C. is 11.3 mm ² / sec, the aromatic content is 29.7% by mass, and the amount of asphaltenes is 0 .2% by mass was used.

Next, the aromatic content in the asphalt binder of each Example and Comparative Example, the viscosity at 60 ° C., and the complex modulus at 0.1 rad / sec at 25 ° C. were measured. The aromatic content was measured by the method described above using an automatic thin layer chromatography detector (Iatroscan MK-5) manufactured by Mitsubishi Chemical Yatron Corporation. The viscosity at 60 ° C. was measured using a rotational viscometer manufactured by Brookfield. It was measured as Sc4-21 and a measurement rotational speed of 20 rpm. Furthermore, the complex elastic modulus G ^{* at} 25 ° C. was measured by the above-described method using a dynamic viscoelasticity tester (ARES) manufactured by TA Instruments. The results are also shown in Table 1 above. In addition, the underline in the said Table 1 shows that it is outside the scope of the present invention.

And using the asphalt binder of each Example and a comparative example, the reproduction | regeneration asphalt composition was produced, and the workability | operativity in that case and the softness | flexibility of the produced reproduction | regeneration asphalt composition were evaluated. The results are shown in Table 2 below. As for the workability of the asphalt binder shown in Table 2 below, those having fluidity at 25 ° C. were evaluated as “○”, and those having no fluidity at 25 ° C. and requiring heating at the time of operation were evaluated as “x”. Moreover, the flexibility of the regenerated asphalt composition is a reciprocating chain type labeling test (corporate association) that gives a frictional action by hitting a specimen placed on a table with a chain attached to a rotating wheel under a temperature condition of −10 ° C. The Japan Road Association edition (see “Pavement Test Method Handbook”, p. 517), where the wear amount (cross-sectional area) was 1 cm ² or less ○, and the wear amount (cross-sectional area) exceeded 1 cm ² X.

  As shown in Table 2 above, Comparative Example No. 1 consisting only of petroleum-based solvent extracted oil was used. Asphalt binder No. 1 was able to impart flexibility to the regenerated asphalt composition, but its workability was inferior because of its low fluidity. In addition, Comparative Example No. in which the blending ratio of petroleum solvent extracted oil and solvent history asphalt is out of the scope of the present invention. Similarly, the asphalt binder of No. 9 could impart flexibility to the regenerated asphalt composition, but was inferior in workability. Furthermore, comparative example No. which mixed petroleum-based solvent extraction oil and lubricating oil. The asphalt binder No. 13 had good workability, but the aromatic content was less than 70.0% by mass, so that the recycled asphalt composition had poor flexibility.

  On the other hand, Example No. produced within the scope of the present invention. 2-8, no. 10-12 asphalt binders have good workability, and the recycled asphalt composition to which these are added has excellent flexibility.

It is a perspective view which shows typically the measurement part of a dynamic viscoelasticity testing machine.

Explanation of symbols

1 Asphalt binder 2a, 2b

Claims (2)

Asphalt: 0.5-20.0% by mass,
The balance consists of petroleum-based solvent extract oil,
The aromatic content is 70.0% by mass or more,
The complex elastic modulus at 25 deg. C at 0.1 rad / sec is 10.0 Pa or less,
The asphalt is an asphalt binder characterized in that it is a solvent asphalt, straight asphalt, blown asphalt or a mixture of two or more of these asphalts, and the asphaltene content is 40.0% by mass or less . The asphalt binder according to claim 1, having a flash point of 250 ° C or higher.

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