JP2001302850A - Modifier for asphalt, and asphalt composition containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an asphalt composition excellent in fluidity resistance and abrasion resistance (hardly causing ruts, and cracks), that is the one capable of improving the durability of a pavement, and further to provide a modifier for the asphalt suitable for obtaining the asphalt composition. SOLUTION: This modifier for the asphalt comprises a rubber such as a reclaimed rubber, and a wax such as a waxy material. The asphalt composition comprises, for example, a straight asphalt, and the modifier for the asphalt. The reclaimed rubber can be easily produced by cleaving sulfur-cross-linking points of the rubber molecules of a waste tire by using an autoclave, a twin- screw extruder or the like. The waxy material C is obtained by charging a basket 2 for burning with a prescribed amount of a raw material A, thermally decomposing a part of the raw material to provide a molten product B, and further thermally decomposing the molten product B in an oxygen-lacking state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an asphalt modifier and an asphalt composition containing the same.

[0002]

2. Description of the Related Art In recent years, with the increase in traffic volume and the number of large vehicles, pavement roads using, for example, straight asphalt have sufficient durability due to rutting and cracks (cracks) caused by plastic flow. Is no longer available. Therefore, in order to cope with an increase in traffic volume and an increase in the number of large vehicles, in order to improve the durability of the pavement road, an asphalt composition having excellent fluid resistance and abrasion resistance (it is hard to cause rutting and cracking). Or an asphalt mixture containing the asphalt composition and an aggregate.

[0003] In order to improve various functions of the straight asphalt, it has been customary to add a modifier to the straight asphalt to form an asphalt composition. As the modifying material, for example, thermoplastic resins such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyethylene, polypropylene, polystyrene, and acrylic resin are used. These modifiers are used by adding about 8% by weight to the straight asphalt, for example, by external addition. The conventional asphalt composition is called, for example, a modified asphalt type I or a modified asphalt type II. As the thermoplastic resin, waste plastics and waste materials (industrial waste) are used.

[0004]

However, the asphalt composition containing the above-mentioned conventional modifier has the following problems. That is, an asphalt composition containing a thermoplastic resin as a modifier is excellent in flow resistance, but brittle,
Easy to crack. Therefore, a pavement road using an asphalt mixture containing the asphalt composition is vulnerable to cold, and is not suitable for use in a cold region, for example, in an area where snow is accumulated in winter or an area where the road is likely to freeze below freezing and freeze. Further, since the softening point of the thermoplastic resin is about 120 ° C. to 130 ° C., the thermoplastic resin is liable to be deteriorated when mixed with the heated and melted straight asphalt. Further, since the thermoplastic resin is weak to ultraviolet rays, the pavement road using the asphalt mixture containing the thermoplastic resin promotes deterioration of a portion exposed on the road surface, and cracks and chips due to solidification embrittlement. Easy to occur.

[0005] Therefore, an asphalt composition which is excellent in various mechanical strengths such as fracture resistance and the like, and which is excellent in flow resistance and wear resistance, that is, an asphalt composition which can improve the durability of a pavement road, is provided. It has been demanded. Further, there is a need for a modifier suitable for obtaining the asphalt composition.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide an asphalt composition capable of improving the durability of a pavement road, and to obtain the asphalt composition. It is to provide a cheap asphalt modifier at low cost.

[0007]

The asphalt modifier of the present invention is characterized by containing rubber and wax in order to solve the above-mentioned problems.

[0008] In order to solve the above-mentioned problems, the asphalt modifier of the present invention is characterized in that the rubber is a recycled rubber obtained by treating a waste tire.

In order to solve the above-mentioned problems, the asphalt modifying material of the present invention is characterized in that the wax is obtained by charging a raw material comprising a synthetic resin, which is a raw material, and a fuel into a combustion basket, and mixing the fuel with the raw material. The synthetic resin is melted by burning, and a part of the resin is thermally decomposed to low molecular weight and liquefied, and the mixture, which is a mixture thereof, is dropped into a catalyst tank in an oxygen-deficient state. Pyrolysis of synthetic resin that has not been thermally decomposed or synthetic resin that is not sufficiently thermally decomposed to lower molecular weight to obtain a wax-like substance, while a part of the wax-like substance in a molten state is vaporized and generated. A wax-like substance obtained by a method of controlling the temperature in the combustion basket to a predetermined temperature by burning the combustible high-temperature gas in the combustion basket, wherein the main component is Consists sum chain hydrocarbon, the weight ratio of carbon and hydrogen (C / H) is 5.839 to 6.018,% by weight of the sum of carbon and hydrogen 98.5% 10
0%, and the number average molecular weight (Mn) is 3.0 × 10 ^3-
1.0 × 10 ⁴ and a weight average molecular weight (Mw) of 1.
0 × 10 ^{4 to} 5.0 × 10 ⁴ , and Mw / Mn is 1.
0 to 5.0.

According to the above construction, an asphalt composition excellent in flow resistance and abrasion resistance (in which rutting or cracking is unlikely to occur), that is, an asphalt composition capable of improving the durability of a pavement road is provided. Asphalt modifier suitable for obtaining can be provided at a lower cost than conventional modifiers.

Further, about 3 million tons of waste tires are discarded annually, of which 50% is recovered by heat after being incinerated as fuel, and only 10 to 12% is used as recycled rubber. And the remaining 38 ~
40% are illegally dumped, and the actual situation is not known.
For example, waste tires piled up in the field cause social problems such as causing a fire. According to the above configuration, since the demand for recycled rubber can be increased, the utility value of the waste tire is increased, and as a result, illegal dumping can be reduced.

[0012] The asphalt composition of the present invention is characterized by containing the above asphalt modifier in order to solve the above problems.

[0013] According to the above configuration, the asphalt composition can be hardened as compared with the case where the conventional modifier is included, and the flow resistance can be increased by including rubber, and the wax can be improved. , The wear resistance can be increased. Therefore, it is possible to provide an asphalt composition excellent in fluidity resistance and abrasion resistance (in which rutting and cracks are unlikely to occur), that is, an asphalt composition capable of improving the durability of a pavement road.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The asphalt modifier according to the present invention (hereinafter simply referred to as modifier) comprises rubber and wax. Further, the asphalt composition according to the present invention includes asphalt such as straight asphalt and the above-mentioned asphalt modifier.
Further, the asphalt mixture contains the above asphalt composition, aggregate and the like.

The rubber according to the present invention is not particularly limited. For example, styrene-butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, isobutylene-isoprene rubber, butadiene rubber, ethylene-propylene rubber, styrene- Rubber such as isoprene rubber and natural rubber; or styrene-butadiene block copolymer, styrene-isoprene block copolymer, styrene-ethylene-butylene block copolymer, polyolefin-based elastomer, polyester-based elastomer, polyurethane-based elastomer, And the like. One type of these rubbers may be used, or two or more types may be used in combination. Of the rubbers exemplified above, styrene-butadiene rubber is more preferable, and furthermore, the tire contains a large amount of styrene-butadiene rubber, and from the viewpoint of effective use of resources, waste tires that are industrial waste are treated. Recycled rubber is most suitable.

The above-mentioned reclaimed rubber is easily and inexpensively obtained by pulverizing a waste tire into a pulverized product (rubber powder) and then cutting the sulfur cross-linking points of the rubber molecules using an autoclave or a twin-screw extruder. Can be manufactured. As a specific method of grinding waste tires, for example, after freezing,
A method of pulverizing to obtain a pulverized product may be mentioned, but is not particularly limited. Therefore, the recycled rubber in the present invention does not refer to a granular hard rubber obtained by simply grinding a waste tire, but refers to a soft rubber in which a sulfur crosslinking point of a rubber molecule is cut. Table 1 shows the physical properties of some types of recycled rubber.

"T-101" in Table 1 is obtained by externally adding a predetermined compounding agent to 100% of a tire chip manufactured by pulverizing a waste tire and kneading it using a twin-screw extruder. Recycled rubber, “T-201” is a recycled rubber obtained by externally adding a compounding agent different from the above compounding agent to 100% of the tire chip, and “T-301” is 80% of the tire chip. And recycled rubber obtained by mixing 20% of the filler and 20% of the filler.
% And filler 25%.
“T-910” is a 100% tube tip recycled rubber manufactured by pulverizing a tire tube made of butyl rubber and kneading it using a twin-screw extruder.

[0018]

[Table 1]

The various test methods for obtaining the physical properties shown in Table 1 were based on the methods described in JIS K 6313. Mooney viscosity is 2
This is a measured value after 4 hours.

When the modifier contains rubber, the asphalt mixture containing the asphalt composition is provided with elasticity and viscosity, thereby preventing cracks (cracks) and abrasion and providing an anti-slip effect. That is, when the modifier contains rubber, the asphalt mixture containing the asphalt composition has high flow resistance and is less likely to crack.

As the wax (wax) according to the present invention, natural waxes such as paraffin wax (petroleum wax) and synthetic waxes which are solid or semi-solid at room temperature are suitable, and the wax-like substances described in detail below. (Synthetic wax) is optimal.

That is, the waxy substance according to the present invention comprises:
For example, it can be obtained by subjecting a synthetic resin as a raw material that is heated and melted to a thermal decomposition reaction. Examples of the synthetic resin include non-crosslinked, low-crosslinked, or highly crosslinked polyethylene resins, polyolefins such as polypropylene resins, and polystyrene resins. The synthetic resin is not particularly limited as long as it is a resin capable of obtaining a wax-like substance by a thermal decomposition reaction. For example, waxy substances can be produced at low cost from synthetic resin waste such as polyethylene resin and polypropylene resin. That is, the modifier containing the wax-like substance can be provided at a lower cost than the conventional modifier.
The method for producing the wax-like substance will be described later in detail.

Next, the wax-like substance according to the present invention will be described below. First, various physical properties of the wax-like substance will be described. Elemental analysis of the wax-like substance was performed by the following method. The molecular weight and molecular weight distribution of the waxy substance were measured by the following methods. Further, various physical properties (physical properties) of the waxy substance were measured. That is, the melting point and specific gravity of the wax-like substance were measured by the following methods, and a flow test, a hardness test, a tensile test, and a bending test were performed by the following methods.

[Elemental analysis] Each weight% of carbon, hydrogen, nitrogen and sulfur and each content (μg / g) of total chromium, cadmium and lead were measured. Each weight% of carbon, hydrogen and nitrogen was measured by a C, H and N meter. The weight percentage of sulfur was measured by a turbidimetric method after burning by a combustion tube type quartz tube oxygen method based on JIS K2541. Each content of total chromium, cadmium and lead was measured by the atomic absorption method. Each measurement was performed under the conditions of a test room temperature of 19 ° C. As a result, carbon, hydrogen, nitrogen and sulfur are, in this order, 84.5% by weight, 14.3% by weight, 0.2% by weight,
It was less than 0.02% by weight. The contents of total chromium, cadmium and lead were all below the detection limit (total chromium: 10 μg / g or less, cadmium: 2 μg / g or less, lead: 5 μg / g or less).

[Molecular Weight and Molecular Weight Distribution] The number average molecular weight (Mn) and the weight average molecular weight (Mw) were measured by GPC. Measurement conditions are as follows: Column: AD80M / S Mobile phase: o-dichlorobenzene Detector: IR (3.42 μm) Temperature: 140 ° C. Flow rate: 1.0 ml / min Sample concentration: 2.0 mg / ml The test was performed under the conditions of a room temperature of 22 ° C. As a result, the number average molecular weight was 6.5 × 10 ³ , the weight average molecular weight was 2.2 × 10 ⁴ , and the molecular weight distribution (Mw / M
n) was 3.3.

[Melting point] Based on JIS K 7122,
The melting peak temperature (° C.) was measured by the DSC method. The tester is DSS-220C manufactured by Seiko Electronic Industry Co., Ltd.
It was used. The measurement conditions were as follows: Temperature rising rate: 10 ° C./min. As a result, the melting peak temperature was 108 ° C.

[Specific gravity] Based on JIS K 7112,
It was measured by the underwater displacement method. The measurement was performed at a test room temperature of 2
The test was performed at 1 ° C. As a result, the specific gravity was 0.935.

[Flow test] Based on JIS K7210, the viscosity (Pas) was measured using a Koka type flow tester.
And the melting start temperature (° C.) were measured. The viscosity is 40
The values at 60 ° C, 60 ° C, 80 ° C, and 100 ° C were measured by a constant temperature test. The measurement conditions were as follows: Die diameter: 1 mm Test load: 98 N to 4900 N (10 kgf to 50 N)
0 kgf) The melting start temperature was measured by a temperature rise test.
The measurement conditions were: die diameter: 1 mm, test load: 98 N (10 kgf), heating rate: 3 ° C./min, and the measurement was performed at a test room temperature of 21 ° C. As a result, the viscosities at 40 ° C., 60 ° C., 80 ° C., and 100 ° C. were not measured in this order, and 6.6 × 10 ⁵ Pas (6.
6 × 10 ⁶ poise), 2.3 × 10 ³ Pas (2.3 ×
10 ⁴ poise), 3.0 × 10 ² Pas (3.0 × 10
³ poise). The melting start temperature was 97 ° C.

[Hardness test] Hardness (HDD) was measured based on JIS K 7215. The measurement was performed under the conditions of a test room temperature of 21 ° C. As a result, the hardness is 48HD
D.

[Tensile test] The tensile strength (Pa) was measured based on JIS K 7113. The measurement conditions were as follows: Test piece: No. 1 type Test speed: 50 mm / min The measurement was carried out at a test room temperature of 21 ° C. As a result, the tensile strength was 6.468 × 10 ⁶ Pa (66 kgf
/ Cm ² ).

[Bending test] Based on JIS K 7203, the bending strength (Pa), the bending elastic modulus (Pa), the pushing amount (mm) until breaking, and the pushing amount (mm) until yielding were measured. did. The measurement conditions were as follows: Test piece: 80 mm × 10 mm × 2 (t) mm Test speed: 1 mm / min Distance between fulcrum points: 30 mm The measurement was performed at a test room temperature of 21 ° C. As a result, the bending strength was 9.408 × 10 ⁶ Pa (0.96 k
gf / mm ² ) and the flexural modulus is 4.508 × 10
^The pressure was ⁸ Pa (46 kgf / mm ² ), and the pushing amount before breaking was 1.85 mm. When the indentation amount until yielding was measured, the test piece was broken at 1.85 mm.

The results of the above measurements will be discussed below. First, the analysis results of elemental analysis, molecular weight and molecular weight distribution will be considered. The molecular formula of the saturated chain hydrocarbon (paraffin hydrocarbon) is represented by C _n H _{2n + 2} . Since the atomic weight of carbon is 12.011 and the atomic weight of hydrogen is 1.00794, the weight ratio (C / H) between carbon and hydrogen is approximately 5.958.

The weight ratio of the wax-like substance is 5.909. Also, the total weight percent of carbon and hydrogen is 98.8%
It is. That is, it is understood that the main component of the wax-like substance is composed of a saturated chain hydrocarbon. Further, the wax-like substance has a number average molecular weight of 6.5 × 10 ³ , a weight average molecular weight of 2.2 × 10 ⁴ , and Mw / Mn of 3.3.

The waxy substances have different physical properties if they have different compositions, molecular weights and molecular weight distributions. The waxy substance is a mixture of various saturated chain hydrocarbons,
The various physical properties appear as an overall result of the complex crystal structure of the component hydrocarbon. Therefore, it is considered that the physical properties of the wax-like substance are expressed when the composition, molecular weight, and molecular weight distribution are delicately related to each other.

Next, the measurement results of the melting point, the flow test, and the hardness test will be considered. The wax-like substance has a melting peak temperature of 108 ° C, a melting start temperature of 97 ° C, and a hardness of 48.
HDD, viscosities of 6.6 × 10 ⁵ Pas (6.6
× 10 ⁶ poise), 2.3 × 10 ³ Pas at 80 ° C
(2.3 × 10 ⁴ poise), 3.0 × 10 ² at 100 ° C.
Pas (3.0 × 10 ³ poise) (viscosity at 40 ° C. could not be measured because no waxy material melted). For this reason, since the asphalt mixture containing the asphalt composition is hard to soften even when exposed to a high temperature (for example, in the summer season) because the modifier contains the wax-like substance, the abrasion resistance is high, and rutting occurs. It turns out that it is difficult.

Next, test results of a tensile test and a bending test will be considered. The waxy substance has a tensile strength of 6.
468 × 10 ⁶ Pa (66 kgf / cm ² ) and a flexural strength of 9.408 × 10 ⁶ Pa (0.96 kgf / m)
m ² ) and a flexural modulus of 4.508 × 10 ⁸ Pa (46 k
gf / mm ² ), and the indentation amount before breaking was 1.85 mm (the indentation amount until yielding could not be measured because the test piece was broken at 1.85 mm). For this reason, as the asphalt mixture containing the asphalt composition, even when various stresses such as a compressive stress and a tensile stress are applied to the asphalt mixture containing the asphalt composition, it is difficult for the surface cracks to be easily generated by the modifier containing the waxy substance. I understand.

As is apparent from the above results, the above-mentioned modifier containing a wax-like substance is suitable for obtaining an asphalt composition capable of improving the durability of a pavement road. The wax-like substance is mixed at a mixing temperature (150 ° C. to 185) at which asphalt and aggregate are mixed.
C), and is excellent in compatibility and affinity with asphalt and aggregate, and also excellent in low-temperature brittleness. The modifier according to the present invention contains a wax such as the above-mentioned wax-like substance together with the rubber.
Incidentally, the wax-like substance is harmless.

Next, the inventor of the present application has proposed a wax-like composition suitable for obtaining an asphalt composition which is more excellent in various mechanical strengths such as fracture resistance and the like, and further excellent in flow resistance and abrasion resistance. The range of each physical property of the substance was studied diligently. As a result, it is not clear which of the above physical properties is significantly related to the physical properties of the asphalt composition, but if the physical properties of the wax-like substance are within the following ranges, a good asphalt composition It turned out that things were obtained.

That is, the weight ratio of carbon to hydrogen (C / H)
Is preferably in the range of 5.839 to 6.018.
New The total weight percent of carbon and hydrogen is between 98.5% and
It is preferable that it is within the range of 100%. Number average molecular weight
(Mn) is 3.0 × 10^Three~ 1.0 × 10^FourWithin range
It is preferable that the weight average molecular weight (Mw) is
1.0 × 10^Four~ 5.0 × 10^FourWithin the range of
Preferably, Mw / Mn is in the range of 1.0 to 5.0.
Preferably. The melting peak temperature is from 100 ° C to 12 ° C.
Preferably it is in the range of 0 ° C. Viscosity at 60 ° C
3.0 × 10^FivePas ~ 1.2 × 10⁶Pas (3.0
× 10⁶poise ~ 1.2 × 10⁷poise), 8
1.0 × 10 at 0 ° C.^ThreePas ~ 5.0 × 10^ThreePas
(1.0 × 10 ^Fourpoise 〜5.0 × 10^Fourpoise) range
1.0 × 10 at 100 ° C^TwoPas ~ 6.0 × 10
^TwoPas (1.0 × 10^Threepoise ~ 6.0 × 10^Threepois
e) is preferably within the range, and the melting onset temperature is
The temperature is preferably in the range of 90C to 110C. Hardness
Is preferably in the range of 40 HDD to 60 HDD.
New Tensile strength is 5.39 × 10⁶Pa-7.35x
10⁶Pa (55 kgf / cm^Two~ 75kgf / c
m^Two) Is preferable. The bending strength is
7.84 × 10⁶Pa-1.176 × 10⁷Pa (0.
8kgf / mm^Two~ 1.2kgf / mm^Two) Within
Preferably, the flexural modulus is 3.43 × 10⁸
Pa-5.39 × 10⁸Pa (35 kgf / mm^Two~ 5
5kgf / mm^Two) Is preferable. Breaking
The pushing amount until breakage is within the range of 1.7mm to 1.9mm
Preferably, there is. Also has little elasticity
Is more preferred. The properties of the waxy substance are shown above.
Out of the range, a good asphalt composition can be obtained.
I can't do that.

Next, a method for producing the above-mentioned wax-like substance will be described below with reference to an example. As shown in FIG. 1, the apparatus for producing a wax-like substance includes a storage tank 1 for storing the wax-like substance C. The storage tank 1 is supported by legs 1a. A cylindrical combustion basket 2 is integrally mounted and fixed to the tank upper end opening 1b of the storage tank 1. And
The side walls of the basket for combustion 2 have numerous air introduction holes 2b.
… Is drilled. The upper end opening 2c of the combustion basket 2 is in an open state. At the lower part in the above-mentioned combustion basket 2, a rostr 3, which is a convex raw material receiving tray, is installed so as to close the lower end opening 2 a of the combustion basket 2 from above. A number of rostr holes 3a are formed in the rostr 3. Then, the raw material A (to be described later) is placed on the roaster 3.

A closed box-shaped catalyst tank 4 is attached to the lower part of the combustion basket 2 so as to close the lower end opening 2a from below. The catalyst tank 4
The entire wall has a mesh portion 4a. The above-mentioned catalyst tank 4
The inside is filled with a catalyst for promoting a thermal decomposition reaction of the melt B (described later), for example, a linear catalyst 4b made of a metal such as platinum or copper. Then, the melt B passes between the linear catalysts 4b.

A cylindrical air balancer 5 is provided on the outer periphery of the combustion basket 2 for adjusting the amount of air to be supplied to the combustion basket 2. The air balancer 5 is installed at a predetermined distance from the combustion basket 2. In addition, an opening 5a for introducing air is provided below the air balancer 5. The upper part of the air balancer 5 is open.

A plurality of communication pipes (not shown) are provided between the storage tank 1 and the combustion basket 2. These communication pipes are connected to a pump (not shown) for sending out gas generated in the storage tank 1 to the combustion basket 2.

A pipe-shaped heater 6 is provided at the inner bottom of the storage tank 1 in order to raise the temperature of the molten wax-like substance C. The heater 6 heats the wax-like substance C by electric heating or high-frequency heating. Further, a temperature sensor 7 such as a bimetal or a thermocouple for detecting the temperature of the wax-like substance C is provided inside the storage tank 1. The heater 6 is ON / OFF controlled or proportionally controlled by the control means 8. The control means 8 controls the heater 6 based on the signal from the temperature sensor 7 so as to keep the wax-like substance C at a predetermined temperature.

Next, a method for producing the wax-like substance C using the production apparatus having the above configuration will be described. First, a predetermined amount of a raw material A including a synthetic resin as a raw material and a fuel as a highly crosslinked polyethylene resin or a polypropylene resin is charged into the combustion basket 2. Next, the synthetic resin is melted by igniting and burning the fuel, and a part of the synthetic resin is thermally decomposed to be reduced in molecular weight and liquefied.
Then, a melt B, which is a mixture thereof, is dropped from the roastor holes 3a, passes between the linear catalysts 4b of the catalyst tank 4, and is dropped into the storage tank 1.

At this time, oxygen in the catalyst tank 4 and the storage tank 1 reacts with the melt B and is quickly consumed. Therefore, the inside of the catalyst tank 4 and the inside of the storage tank 1 are in an oxygen-deficient state. Thereby, the resin which has not been thermally decomposed or the resin which has not been thermally decomposed in the melt B is thermally decomposed mainly in the catalyst tank 4 in an oxygen-deficient state, and becomes a low molecular weight wax substance C. The wax-like substance C is stored in the storage tank 1 in a molten state.

The waxy substance C in a molten state
Is heated by the heater 6 and controlled by the temperature sensor 7 and the control means 8, so that its melting temperature is maintained at a predetermined temperature. Therefore, since the wax-like substance C is in an oxygen-deficient state and has a stable melting temperature, the high-heat gas G such as a flammable ethylene gas in which a part of the wax-like substance C is vaporized is used. It occurs stably. The melting temperature of the waxy substance C is about 60
What is necessary is just to set so that it may be set to 0 degreeC.

The hot gas G whose generation amount is controlled as described above
Reaches the combustion basket 2 where the raw material A is burned, by ascending through the catalyst tank 4 and the rostral 3 or via a communication pipe and a pump (not shown). The high-heat gas G is mixed with air introduced from the air introduction holes 2b and burns. For this reason, the temperature in the combustion basket 2 is controlled to a predetermined temperature.
Thereby, the melting / decomposition of the raw material A continuously supplied to the combustion basket 2 is continued. The internal temperature of the combustion basket 2 is preferably about 1100 ° C. The particulate carbon is also generated from the wax-like substance C together with the high-temperature gas G, and the generated particulate carbon is entirely burned in the combustion basket 2. Therefore, carbon soot does not adhere to the inside of the combustion basket 2. Therefore, carbon soot is not mixed into the wax-like substance C.

By the above method, a wax-like substance suitably used for the modifier according to the present invention is produced. Of course, the production apparatus and the production method of the wax-like substance are not limited to the production apparatus and the production method described above. That is, the wax-like substance according to the present invention is not limited to those manufactured by the above-described method. In other words, the waxy substance may be manufactured in any manner as long as it has the function and effect of being suitable for obtaining an asphalt composition capable of improving the durability of a pavement road.

Examples of the asphalt according to the present invention include straight asphalt (petroleum asphalt),
Modified asphalt, natural asphalt and the like can be mentioned, and straight asphalt is particularly preferred. The straight asphalt is a bituminous substance obtained by distilling crude oil using an atmospheric distillation apparatus or a vacuum distillation apparatus to remove light components. As the above-mentioned modified asphalt, for example, a modified blowing asphalt with improved viscosity at 60 ° C. by improving the temperature sensitivity by performing a slight blowing operation on heated straight asphalt, or a conventional modified material Including modified asphalt type I and modified asphalt II
And the like.

The method for producing the modifier according to the present invention, that is, the method for mixing the rubber and the wax is not particularly limited. Further, the method for producing an asphalt composition according to the present invention, that is, the above asphalt,
The method of mixing the modifier containing rubber and wax is not particularly limited, and a method of mixing a conventional modifier with asphalt, that is, a conventionally used mixing method is adopted. Can be. Therefore, the rubber and the wax only need to be mixed with the asphalt at the time of performing the pavement construction using the asphalt mixture containing the asphalt composition. The mixing temperature is 1
The temperature is preferably about 50 ° C to 185 ° C, but is not particularly limited. Further, the form of the rubber and the wax at the time of mixing may be any of a powder form and a particle form. The asphalt composition according to the present invention comprises a modifier containing the above rubber and wax, and asphalt.

As the amount of the wax added increases, the penetration (25 ° C.) of the asphalt composition decreases, the asphalt composition becomes harder, the softening point increases, and the elongation (7 ° C.,
15 ° C., ductility) is low, the Frass embrittlement point is high and brittle, in the toughness-tenacity test,
The toughness value (25 ° C) increases, the adhesive strength decreases,
In addition, the tenacity value (25 ° C.) decreases, and the viscosity (6
0 ° C.) and high temperature kinematic viscosity (150 ° C., 180 ° C.). Also, as the addition amount of the wax increases, the asphalt mixture using the asphalt composition, the marshalling stability increases, the flow value decreases, the flexibility decreases, the wheel tracking increases, the flow resistance increases. Become. On the other hand, as the amount of added rubber increases, the flow resistance increases, and the toughness (gripping force) and the tenacity (adhesive force) of the asphalt composition can be increased.

Therefore, the amount of wax to be added may be appropriately set so as to be an optimum amount according to various properties to be imparted to the asphalt composition in consideration of the amount of rubber to be added. The ratio between the amount of rubber added and the amount of wax added is not particularly limited, but is preferably in the range of 2: 8 to 5: 5 by weight (rubber: wax). And
For example, when the asphalt is straight asphalt, the total addition amount of rubber and wax is 4 to 6 parts (that is, 4 to 6% by weight externally added) based on 100 parts of the straight asphalt. Although the degree is suitable, it may be set according to, for example, the state of the ground of the road to be paved, the composition of the asphalt mixture, the use conditions, and the like, and is not particularly limited.

As the aggregate according to the present invention, specifically, for example, crushed stone, crushed stone, gravel, sand, rubber, wood chips, steel slag, recycled aggregate, or hard aggregate, light-colored aggregate, coloring Aggregates and the like, but are not particularly limited,
Various aggregates conventionally used for asphalt mixtures can be employed.

The method for producing the asphalt mixture according to the present invention, that is, the method for mixing the above-mentioned asphalt composition with the aggregate and the like is not particularly limited, and a conventional mixing method is employed. be able to. Therefore, the asphalt mixture only needs to be formed when the pavement work is performed. The mixing temperature is 15
A temperature of about 0 ° C. to 185 ° C. is suitable, but not particularly limited. The asphalt mixture according to the present invention comprises the above asphalt composition and an aggregate.
The mixing ratio of the asphalt composition and the aggregate in the asphalt mixture is not particularly limited.

The asphalt mixture contains the above-mentioned asphalt composition and aggregate, and may further contain filler such as stone powder, slaked lime, cement, collected dust, fly ash and the like, if necessary. As the filler, various fillers conventionally used in asphalt mixtures can be employed. Further, the asphalt mixture may further contain additives such as an anti-peeling agent, a fibrous reinforcing material, a freeze retardant, an oil absorbing material, and a regeneration additive, as necessary. As the additive, various additives conventionally used in asphalt mixtures can be employed. The mixing ratio of the filler and the additive in the asphalt mixture is not particularly limited.

As described above, the modifier according to the present invention comprises:
It contains rubber such as recycled rubber and wax such as a wax-like substance. Further, as described above, the asphalt composition according to the present invention includes asphalt and the above-described modifier. Further, as described above, the asphalt mixture according to the present invention includes the above-mentioned asphalt composition, aggregate, and the like.

According to the above-mentioned structure, an asphalt composition excellent in flow resistance and abrasion resistance (in which rutting or cracking is unlikely to occur), that is, an asphalt composition capable of improving the durability of a pavement road, can be obtained. Modifiers suitable for obtaining can be provided at a lower cost than conventional modifiers. When the recycled rubber is used as the rubber, the demand for the recycled rubber can be increased, so that the use value of the waste tire is increased, and as a result, illegal dumping can be reduced. Further, according to the above configuration, the asphalt composition can be hardened, and the flow resistance and the abrasion resistance can be increased as compared with the case where the conventional modifier is included. Therefore, since it is excellent in flow resistance and abrasion resistance, it is possible to provide an asphalt composition in which rutting due to plastic flow hardly occurs and which can improve the durability of a pavement road.

The place where the asphalt composition or asphalt mixture to which the modifier according to the present invention is added is not particularly limited. The method and machine for constructing a pavement road using the asphalt mixture are not particularly limited, and various methods and machines conventionally used can be adopted.

[0060]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In addition, the measuring method (test method) of various physical property values is as follows.
It was carried out according to the method described in the pavement test method handbook.

[Method of Producing Asphalt Composition] A predetermined amount of a recycled rubber (T-101 in Table 1) and a wax-like substance are added little by little to straight asphalt (60/80) while being careful not to cause bumping. 160 ° C-1
The asphalt composition was manufactured by stirring and mixing at 65 ° C. for 90 minutes. The amount of the recycled rubber and the wax-like substance added was determined using straight asphalt 2000
100 g (that is, 5 wt% by external addition) with respect to g.
The weight ratio between the recycled rubber and the wax-like substance is 4: 6.
And At this time, it was confirmed that no bubbles were generated (defoamed) in the asphalt composition.

Table 2 summarizes various physical property values measured using the obtained asphalt composition. The standard properties of modified asphalt type I and type II are asphalt pavement outline (edited and published by Japan Road Association; Heisei 9
The quality standard and properties (specifications) described in the revised edition, 14th edition, July 10, 2008) were used.

[0063]

[Table 2]

[0064]

As described above, the asphalt modifier of the present invention has a constitution containing rubber and wax.

As described above, the asphalt modifier of the present invention has a configuration in which the rubber is a recycled rubber obtained by treating a waste tire.

As described above, the modifier for asphalt according to the present invention is characterized in that the wax is made of a synthetic resin as a raw material,
A raw material composed of a fuel is put into a combustion basket, and the synthetic resin is melted by burning the fuel, and a part of the synthetic resin is thermally decomposed into a low-molecular-weight liquid, which is a mixture thereof. Is dropped into a catalyst tank in an oxygen-deficient state to thermally decompose a synthetic resin that has not been thermally decomposed or a synthetic resin that is not sufficiently thermally decomposed, to obtain a low molecular weight wax substance, By burning the combustible high-temperature gas generated by the vaporization of a part of the waxy substance in the combustion basket,
A wax-like substance obtained by controlling the temperature in a combustion basket to a predetermined temperature, the main component of which is a saturated chain hydrocarbon, and the weight ratio of carbon to hydrogen (C / H) is 5. 839 to 6.018, and the total weight percent of carbon and hydrogen is 98.5% to 100%;
Number average molecular weight (Mn) is 3.0 × 10 ^{3 to} 1.0 × 10
⁴ , having a weight average molecular weight (Mw) of 1.0 × 10 ⁴ to
5.0 × 10 ⁴ , and Mw / Mn is 1.0 to 5.0.

Accordingly, it is suitable for obtaining an asphalt composition excellent in flow resistance and abrasion resistance (it is difficult to cause rutting and cracking), that is, an asphalt composition capable of improving the durability of a pavement road. It is possible to provide an effective asphalt modifier at a lower cost than conventional modifiers. In addition, since the demand for recycled rubber can be increased, the utility value of waste tires is increased, and as a result, illegal dumping can be reduced.

As described above, the asphalt composition of the present invention comprises the above-mentioned asphalt modifier.

As a result, the asphalt composition can be hardened and the flow resistance and abrasion resistance can be increased as compared with the case where the conventional modifier is included. Therefore, it is possible to provide an asphalt composition excellent in fluidity resistance and abrasion resistance (in which rutting and cracks are unlikely to occur), that is, an asphalt composition capable of improving the durability of a pavement road. To play.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a production apparatus suitable for producing a wax-like substance used for an asphalt modifier according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiving tank 2 Basket for combustion 3 Rostor 4 Catalyst tank 5 Air balancer A Raw material B Melt C Waxy substance (wax)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI theme coat ゛ (reference) C10C 3/00 C10C 3/00 F term (reference) 4H058 DA14 DA25 GA17 HA25 4J002 AC011 AC031 AC061 AC071 AC091 AC131 AG00Y BB032 BB151 BP011 4J100 AA02P AA03P AB02P CA31 DA01 DA04 HA51

Claims (4)

[Claims] An asphalt modifier comprising a rubber and a wax. 2. The asphalt modifier according to claim 1, wherein the rubber is a recycled rubber obtained by treating a waste tire. 3. The synthetic resin wherein the wax is a raw material.
And the raw material consisting of fuel and
When the synthetic resin is melted by burning the fuel,
Liquefied by thermal decomposition of a part of it
And the mixture of these melts is fed into a catalyst tank in an oxygen-deficient state.
By dropping, the thermal decomposition in the melt
Pyrolyzes synthetic resin that is not
While the molecular weight is reduced to obtain a wax-like substance, it becomes molten.
Flammability generated by vaporization of part of the waxy substance
Burning highly flammable hot gas in the combustion basket
Control the temperature inside the combustion basket to a predetermined temperature.
Wax-like substance obtained by
The main component consists of a saturated chain hydrocarbon, and carbon and hydrogen
Has a weight ratio (C / H) of 5.839 to 6.018,
98.5% to 100% by weight of the total of carbon and hydrogen
And a number average molecular weight (Mn) of 3.0 × 10^Three~ 1.
0x10 ^FourHaving a weight average molecular weight (Mw) of 1.0 ×
10^Four~ 5.0 × 10^FourAnd Mw / Mn is 1.0 to
3. The method according to claim 1, wherein the value is 5.0.
Modifier for asphalt. 4. An asphalt composition comprising the asphalt modifier according to any one of claims 1, 2 and 3.