JP3413390B2 - Asphalt modifier and asphalt composition containing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD 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, due to an increase in traffic volume and an increase in large vehicles, for example, pavement roads using straight asphalt have sufficient durability due to rutting and cracking due to plastic flow. I am not getting any more. Therefore, to improve the durability of paved roads to cope with the increase in traffic volume and the increase in large vehicles, asphalt composition with excellent fluidity and abrasion resistance (hard to cause rutting and cracking) Or an asphalt mixture containing the asphalt composition and aggregate.

Therefore, in order to improve various functions of the straight asphalt, it has been conventionally practiced to add a modifier to the straight asphalt to form an asphalt composition. As the modifier, for example, a thermoplastic resin such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyethylene, polypropylene, polystyrene, acrylic resin, or the like is used. These modifiers are used, for example, by externally adding about 8% by weight to straight asphalt. The conventional asphalt composition is called, for example, modified asphalt type I or modified asphalt type II. Further, 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 is brittle,
Easy to break. Therefore, a paved road using an asphalt mixture containing the asphalt composition is not suitable for use in a cold region such as a region vulnerable to cold, for example, a region having snow in winter or a region where the road is easily frozen due to a freezing point. Further, since the softening point of the thermoplastic resin is about 120 ° C. to 130 ° C., the thermoplastic resin is liable to deteriorate when mixed with the straight asphalt which is heated and melted. Further, since the thermoplastic resin is weak against ultraviolet rays, the paved road using the asphalt mixture containing the thermoplastic resin accelerates the deterioration of the portion exposed on the road surface, and cracks and chips due to solidification embrittlement. It is easy to occur.

Therefore, an asphalt composition excellent in various mechanical strengths such as fracture resistance and excellent in fluidity resistance and abrasion resistance, that is, an asphalt composition capable of improving the durability of a paved 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 conventional problems, and an object thereof is to obtain an asphalt composition capable of improving the durability of a paved road, and to obtain the asphalt composition. The purpose is to provide a cheap asphalt modifier.

[0007]

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

In order to solve the above 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 modifier of the present invention is such that the above-mentioned wax puts a raw material consisting of a synthetic resin as a raw material and a fuel into a combustion basket, The synthetic resin is melted by burning, and a part of it is pyrolyzed to lower the molecular weight to liquefy, and the melt, which is a mixture of them, is dropped into the catalyst tank in the oxygen deficient state. A non-pyrolytic synthetic resin or a synthetic resin with insufficient thermal decomposition was pyrolyzed to lower the molecular weight to obtain a wax-like substance, while a part of the wax-like substance in a molten state was 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 a flammable high-heat gas in the combustion basket, the main component of which 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 to
1.0 × 10 ⁴ , and the weight average molecular weight (Mw) is 1.
0 × 10 ^{4 to} 5.0 × 10 ⁴ , and Mw / Mn is 1.
It is characterized by being 0 to 5.0.

According to the above constitution, an asphalt composition excellent in fluidity resistance and wear resistance (hard to cause rutting or cracking), that is, an asphalt composition capable of improving durability of a paved road is provided. The asphalt modifier suitable for obtaining can be provided at a lower cost than conventional modifiers.

About 3 million tons of waste tires are discarded annually, of which 50% is recovered as heat by incineration as fuel, and utilization as recycled rubber is limited to 10 to 12%. And the remaining 38 ~
40% are not dumped illegally
For example, there are social problems such as waste tires piled up in the field causing a fire. According to the above configuration, since the demand for recycled rubber can be increased, the utility value of waste tires can be increased, and as a result, illegal dumping can be reduced.

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

According to the above construction, the asphalt composition can be made harder than the case where the conventional modifier is contained, and the flow resistance can be enhanced by containing the rubber, and the wax can be obtained. By including, the wear resistance can be enhanced. Therefore, it is possible to provide an asphalt composition having excellent fluidity resistance and abrasion resistance (hard to cause rutting or cracking), that is, an asphalt composition capable of improving the durability of a paved road.

[0014]

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

The rubber according to the present invention is not particularly limited, but 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 elastomer, polyester elastomer, polyurethane elastomer, Thermoplastic elastomers such as; These rubbers may be used alone or in combination of two or more. Of the above-exemplified rubbers, styrene-butadiene rubber is more preferable, and the tire contains a large amount of styrene-butadiene rubber. From the viewpoint of effectively utilizing resources, a waste tire that is an industrial waste is treated. Regenerated rubber made from is most suitable.

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

"T-101" in Table 1 is obtained by pulverizing a waste tire and then crushing it using a twin-screw extruder to 100% of tire chips, and externally adding a predetermined compounding agent. Recycled rubber, "T-201" is a reclaimed rubber obtained by externally adding a compounding agent different from the compounding agent to 100% of the tire chip, and "T-301" is 80% of the tire chip. And a filler of 20% are recycled rubber, and "T-330" is the tire chip 75.
% And 25% filler are recycled rubbers,
"T-910" is a reclaimed rubber having 100% tube tips produced by crushing a tire tube made of butyl rubber and then kneading the same using a twin-screw extruder.

[0018]

[Table 1]

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

When the modifier contains rubber, the asphalt mixture containing the asphalt composition is imparted with elasticity and viscosity to prevent cracks (cracks) and abrasions and to have an anti-slip effect. That is, since the modifier contains rubber, the asphalt mixture containing the asphalt composition has high flow resistance and cracks hardly occur.

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 wax-like substances described in detail below. (Synthetic wax) is most suitable.

That is, the waxy substance according to the present invention is
For example, it can be obtained by subjecting a synthetic resin, which is a raw material substance heated and melted, to a thermal decomposition reaction. Examples of the synthetic resin include non-crosslinked, low-crosslinked, or high-crosslinked polyethylene resin, polyolefin such as polypropylene resin, polystyrene resin, and the like. Further, the above synthetic resin is not particularly limited as long as it is a resin that can obtain a wax-like substance by a thermal decomposition reaction. For example, wax-like substances can be manufactured 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 waxy substance according to the present invention will be described below. First, various physical properties of the waxy substance will be described. Elemental analysis of the waxy substance was performed by the method described below. Moreover, the molecular weight and the molecular weight distribution of the wax-like 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 the specific gravity of the wax-like substance were measured by the methods described below, and the flow test, hardness test, tensile test, and bending test were performed by the methods described below.

[Elemental Analysis] The respective weight% of carbon, hydrogen, nitrogen and sulfur and the respective contents (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% of sulfur was measured by the turbidimetric method after burning by a combustion tube type quartz tube oxygen method based on JIS K2541. The total contents of chromium, cadmium and lead were measured by the atomic absorption method. In addition, each measurement was performed under the conditions of a test room temperature of 19 ° C. As a result, carbon, hydrogen, nitrogen and sulfur were, in this order, 84.5% by weight, 14.3% by weight, 0.2% by weight,
It was less than 0.02% by weight. In addition, the respective contents of total chromium, cadmium and lead were all below the detection limit (total chromium was 10 μg / g or less, cadmium was 2 μg / g or less, and lead was 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 the GPC method. The measurement conditions are: 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 carried out under the condition of 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 Instruments Inc.
It was used. The measurement conditions were as follows: temperature rising rate: 10 ° C./min. Further, the measurement was carried out at a test room temperature of 21 ° C. 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. Also, the measurement is conducted at the test room temperature 2
It was carried out under the condition of 1 ° C. As a result, the specific gravity was 0.935.

[Flow test] Based on JIS K 7210, a viscosity (Pas) is measured by using a Koka type flow tester.
And the melting start temperature (° C.) were measured. Viscosity is 40
Values at ° C, 60 ° C, 80 ° C and 100 ° C were measured by a constant temperature test. The measurement conditions are: Die diameter: 1 mm Test load: 98N-4900N (10kgf-50
0 kgf) The melting start temperature was measured by a temperature rising test.
The measurement conditions were: Die diameter: 1 mm Test load: 98 N (10 kgf) Temperature rising rate: 3 ° C./min. Further, 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 in this order unmeasurable, 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 according to JIS K7215. In addition, the measurement was performed under the condition of the test room temperature of 21 ° C. As a result, the hardness is 48 HD
It was D.

[Tensile Test] 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 performed under the conditions of 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] Bending strength (Pa), bending elastic modulus (Pa), indentation amount to break (mm), and indentation amount to yield (mm) were measured according to JIS K7203. did. The measurement conditions were as follows: test piece: 80 mm × 10 mm × 2 (t) mm Test speed: 1 mm / min Distance between fulcrums: 30 mm Further, the measurement was performed under the conditions of 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
^{It was 8} Pa (46 kgf / mm ² ), and the indentation amount before breaking was 1.85 mm. Moreover, when the amount of indentation until yielding was measured, the test piece was broken at the time of 1.85 mm.

The results of the above measurements will be considered below. First, consider the analysis results of elemental analysis, molecular weight and molecular weight distribution. Molecular formula of the saturated chain hydrocarbon (paraffin hydrocarbons) 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) of carbon and hydrogen is approximately 5.958.

The weight ratio of waxy substances is 5.909. The total weight% of carbon and hydrogen is 98.8%.
Is. That is, it is understood that the wax-like substance has a saturated chain hydrocarbon as the main component. 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.

Different wax-like substances have different physical properties when they differ in composition, molecular weight and molecular weight distribution. The waxy substance is a mixture of various saturated chain hydrocarbons,
The various physical properties appear as a result of the complex crystal structure of the constituent hydrocarbons. Therefore, it is considered that the physical properties of the wax-like substance are expressed by the composition, the molecular weight, and the molecular weight distribution being subtly related to each other.

Next, the measurement results of the melting point, flow test and hardness test will be considered. The waxy substance has a melting peak temperature of 108 ° C., a melting start temperature of 97 ° C., and a hardness of 48.
HDD, viscosity 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 the waxy substance did not melt at all). For this reason, since the modifier contains a wax-like substance, the asphalt mixture containing the asphalt composition is difficult to soften even when exposed to high temperatures (for example, in summer), and thus has high wear resistance and rutting occurs. I find it difficult.

Next, the test results of the tensile test and the bending test will be considered. The waxy material has a tensile strength of 6.
468 × 10 ⁶ Pa (66 kgf / cm ² ), and bending strength of 9.408 × 10 ⁶ Pa (0.96 kgf / m ² ).
m ² ), the flexural modulus is 4.508 × 10 ⁸ Pa (46 k
gf / mm ² ), and the indentation amount to break is 1.85 mm (the indentation amount to yield was unmeasurable because the test piece was broken at 1.85 mm). For this reason, since the modifier contains a wax-like substance, the asphalt mixture containing the asphalt composition is unlikely to have minute cracks on the surface even when subjected to various stresses such as compressive stress and tensile stress. I understand.

As is clear from the above results, it is understood that the above-mentioned modifier containing a wax-like substance is suitable for obtaining an asphalt composition capable of improving the durability of a paved road. The wax-like substance is mixed at a mixing temperature (150 ° C to 185 ° C) at which the asphalt and the aggregate are mixed.
It is stable even at (° C.), Has excellent compatibility and affinity with asphalt and aggregates, and has excellent low-temperature brittleness. The modifying material according to the present invention contains a wax such as the above wax-like substance together with the rubber.
The waxy substance is harmless.

Next, the inventor of the present invention has a wax-like property suitable for obtaining an asphalt composition which is further excellent in various mechanical strengths such as fracture resistance and further excellent in fluidity resistance and abrasion resistance. The range of each physical property of the substance was diligently studied. 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 ranges shown below, a good asphalt composition is obtained. It turns out that you can get things.

That is, the weight ratio of carbon and hydrogen (C / H)
Is preferably in the range of 5.839 to 6.018.
Good The total weight% of carbon and hydrogen is 98.5%-
It is preferably in the range of 100%. Number average molecular weight
(Mn) is 3.0 × 10³~ 1.0 x 10^FourWithin the range of
And the weight average molecular weight (Mw) is
1.0 x 10^Four~ 5.0 x 10^FourBe within the range of
Preferably, Mw / Mn is in the range of 1.0 to 5.0.
Preferably. The melting peak temperature is 100 ° C to 12
It is preferably in the range of 0 ° C. Viscosity at 60 ℃
3.0 x 10^FivePas ~ 1.2 x 10⁶Pas (3.0
× 10⁶poise ~ 1.2 × 10⁷within the range of poise), 8
1.0 x 10 at 0 ° C³Pas ~ 5.0 x 10³Pas
(1.0 x 10 ^Fourpoise ~ 5.0 × 10^FourPoise)
1.0 × 10 at 100 ℃ in the enclosure²Pas ~ 6.0 x 10
²Pas (1.0 x 10³poise ~ 6.0 × 10³pois
It is preferable that the melting start temperature is within the range of e).
It is preferably in the range of 90 ° C to 110 ° C. Hardness
Is preferably in the range of 40 HDD to 60 HDD
Good Tensile strength is 5.39 × 10⁶Pa ~ 7.35 x
10⁶Pa (55 kgf / cm²~ 75kgf / c
m²It is preferably within the range of). Bending strength is
7.84 x 10⁶Pa ~ 1.176 x 10⁷Pa (0.
8 kgf / mm²~ 1.2kgf / mm²) Within
Preferably, the flexural modulus is 3.43 × 10⁸
Pa ~ 5.39 x 10⁸Pa (35 kgf / mm²~ 5
5 kgf / mm²It is preferably within the range of). Break
The amount of pushing until breakage is within the range of 1.7 mm to 1.9 mm
Preferably there is. Also, it has almost no elasticity
Is preferred. The physical properties of the wax-like substance are shown above.
If it is out of the range, a good asphalt composition can be obtained.
I can't.

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

A 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 is
The entire wall has a mesh portion 4a. The above catalyst tank 4
A catalyst for promoting a thermal decomposition reaction of a melt B (described later), for example, a linear catalyst 4b made of a metal such as platinum or copper is filled in the inside. Then, the above-mentioned melt B passes between the linear catalysts 4b.

A cylindrical air balancer 5 is installed on the outer periphery of the combustion basket 2 in order to adjust 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. Further, an opening 5a for introducing air is provided in the lower part of the air balancer 5. The upper part of the air balancer 5 is in an open state.

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

A pipe-shaped heater 6 is installed at the inner bottom of the receiving tank 1 in order to raise the temperature of the wax-like substance C which is molten. The heater 6 electrically or high-frequency heats the wax-like substance C. A temperature sensor 7 such as a bimetal or a thermocouple that detects the temperature of the wax-like substance C is installed inside the receiving 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 of manufacturing the wax-like substance C using the manufacturing apparatus having the above structure will be described. First, a predetermined amount of a raw material A made of a synthetic resin which is a raw material and a fuel which is a highly cross-linked polyethylene resin or polypropylene resin is put into the combustion basket 2. Next, the fuel is ignited and burned to melt the synthetic resin, and a part of the resin is thermally decomposed to lower the molecular weight and liquefy.
Then, the melt B, which is a mixture thereof, is dropped from the roster holes 3a ..., Passed between the linear catalysts 4b of the catalyst tank 4, and dropped into the reservoir tank 1.

At this time, oxygen in the catalyst tank 4 and in the receiving tank 1 reacts with the melt B and is quickly consumed. Therefore, the catalyst tank 4 and the receiving tank 1 are in an oxygen-deficient state. As a result, the resin that has not been thermally decomposed or the resin that 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 substance C. The wax-like substance C is stored in the receiving tank 1 in a molten state.

Wax-like substance C in a molten state
Is heated by the heater 6 and controlled by the temperature sensor 7 and the control means 8 to maintain its melting temperature at a predetermined temperature. Therefore, the wax-like substance C is in an oxygen-deficient state and has a stable melting temperature. Therefore, a part of the wax-like substance C is vaporized to generate a high-heat gas G such as flammable ethylene gas. It occurs stably. The melting temperature of the wax-like substance C is about 60.
The temperature may be set to 0 ° C.

The high-heat gas G whose generation amount is controlled in this way
Reaches the combustion basket 2, which is the combustion place of the raw material A, by ascending through the catalyst tank 4 and the grate 3, or via a communication pipe and a pump (not shown). Then, the high-temperature gas G is mixed with the air introduced from each of the air introduction holes 2b ... And burns. Therefore, the temperature inside the combustion basket 2 is controlled to a predetermined temperature.
As a result, the melting and decomposition of the raw material A that is continuously charged into the combustion basket 2 continues. The internal temperature of the combustion basket 2 is preferably about 1100 ° C. Further, from the wax-like substance C, fine particle carbon is also generated together with the high-heat gas G, but the generated fine particle 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 in the wax-like substance C.

By the above method, a wax-like substance which is preferably used in the modifying material according to the present invention is produced. Of course, the manufacturing apparatus and manufacturing method of the wax-like substance are not limited to the manufacturing apparatus and manufacturing method illustrated above. That is, the wax-like substance according to the present invention is not limited to the one produced by the method exemplified above. That is, the wax-like substance may be produced in any manner as long as it has the action and effect of being suitable for obtaining an asphalt composition capable of improving the durability of a paved 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, but straight asphalt is particularly preferable. The above 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 asphalt in which the temperature sensitivity is improved by performing a slight blowing operation on the heated straight asphalt and the viscosity at 60 ° C. is increased, or a conventional modifier is used. Including modified asphalt type I and modified asphalt II
Examples include molds.

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, a 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 practiced mixing method is adopted. You can Therefore, the rubber and the wax may be mixed with the asphalt at the time when the paving work using the asphalt mixture containing the asphalt composition is performed. The mixing temperature is 1
The temperature is preferably about 50 ° C to 185 ° C, but is not particularly limited. Further, the rubber and wax at the time of mixing may be in the form of powder or particles. The asphalt composition according to the present invention comprises an asphalt and a modifier containing the above rubber and wax.

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

Therefore, the amount of wax added may be appropriately set in consideration of the amount of rubber added and in accordance with the physical properties to be imparted to the asphalt composition. The ratio of the added amount of rubber to the added amount of wax is not particularly limited, but the weight ratio (rubber: wax) is preferably in the range of 2: 8 to 5: 5. And
For example, when the asphalt is straight asphalt, the total addition amount of rubber and wax is 4 parts to 6 parts (that is, 4% by weight to 6% by weight as external addition) with respect to 100 parts of the straight asphalt. The degree is suitable, but it may be set according to, for example, the condition of the ground of the road to be paved, the composition of the asphalt mixture, the conditions of use, etc., and is not particularly limited.

Specific examples of the aggregate according to the present invention include crushed stone, crushed stone, gravel, sand, rubber, wood chips, steel slag, recycled aggregate, hard aggregate, bright aggregate, and coloring. Examples thereof include aggregates, but are not particularly limited,
Various aggregates conventionally used in asphalt mixtures can be adopted.

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 or the like is not particularly limited, and a conventionally used mixing method is adopted. be able to. Therefore, the asphalt mixture may be formed at the time when the pavement work is performed. The mixing temperature is 15
About 0 ° C to 185 ° C is suitable, but it is not particularly limited. The asphalt mixture according to the present invention contains the above-mentioned 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 may contain the above-mentioned asphalt composition and aggregate, and may further contain fillers such as stone powder, slaked lime, cement, recovered dust and fly ash, if necessary. As the filler, various fillers that have been conventionally used in asphalt mixtures can be adopted. Further, the asphalt mixture may further contain additives such as a peeling preventive agent, a fibrous reinforcing material, a freeze retardant material, an oil absorbing material, and a regenerating additive, if necessary. As the additive, various additives conventionally used in asphalt mixtures can be adopted. The blending ratio of the filler and the additive in the asphalt mixture is not particularly limited.

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

According to the above-mentioned constitution, an asphalt composition excellent in fluidity resistance and abrasion resistance (hard to cause rutting or cracking), that is, an asphalt composition capable of improving durability of a paved road is provided. The modifier suitable for obtaining can be provided at a lower cost than the conventional modifier. When recycled rubber is used as the rubber, the demand for the recycled rubber can be increased, so that the utility value of the waste tire is increased, and as a result, illegal dumping can be reduced. Moreover, according to the said structure, compared with the case where a conventional modifier is included, an asphalt composition can be hardened and flow resistance and abrasion resistance can be improved. Therefore, it is possible to provide an asphalt composition having excellent fluidity resistance and abrasion resistance, making it difficult for rutting due to plastic flow to improve the durability of paved roads.

The place of use of the asphalt composition or the asphalt mixture to which the modifier according to the present invention has been added is not particularly limited. Further, the construction method, machine, etc. for constructing a paved road using the asphalt mixture are not particularly limited, and various construction methods, machines, etc. that have been conventionally practiced can be adopted.

[0060]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. In addition, the measuring method (test method) of various physical properties is
The pavement test method was carried out according to the method described in the handbook.

[Method of Producing Asphalt Composition] A predetermined amount of recycled rubber (T-101 in Table 1) and a wax-like substance were added little by little to straight asphalt (60/80), taking care not to bump. 160 ℃ ~ 1
An asphalt composition was produced by stirring and mixing at 65 ° C. for 90 minutes. The amount of the recycled rubber and the wax-like substance added is straight asphalt 2000.
It was 100 g with respect to g (that is, 5% by weight with external addition).
Further, the weight ratio of the recycled rubber and the wax-like substance is 4: 6.
And At this time, it was confirmed that the asphalt composition had no bubbles (defoamed).

Table 2 shows various physical property values measured by using the obtained asphalt composition. The standard properties of modified asphalt type I and type II are asphalt pavement guidelines (edited and published by the Japan Road Association; 1997).
The quality standards and properties (specs) described in the 14th edition of the revised edition issued on July 10, 2014 were used.

[0063]

[Table 2]

[0064]

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

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

As described above, the modifier for asphalt of the present invention comprises the above wax as a raw material and a synthetic resin.
A raw material composed of a fuel and a mixture is put into a combustion basket, the synthetic resin is melted by burning the fuel, and a part of the resin is thermally decomposed into a low molecular weight liquefied product, which is a mixture thereof. Is added to the catalyst tank in the oxygen-deficient state, the synthetic resin that has not been thermally decomposed in the melt or the insufficiently decomposed synthetic resin is thermally decomposed to obtain a wax-like substance by lowering the molecular weight, while the molten state By burning a flammable high-heat gas generated by vaporizing a part of the wax-like substance that has become
4. A waxy 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, the total weight% of carbon and hydrogen is 98.5% to 100%,
Number average molecular weight (Mn) is 3.0 × 10 ^{3 to} 1.0 × 10
⁴ , and the weight average molecular weight (Mw) is 1.0 × 10 ⁴ to
The structure is 5.0 × 10 ⁴ , and Mw / Mn is 1.0 to 5.0.

Thus, it is suitable to obtain an asphalt composition having excellent fluidity resistance and abrasion resistance (hard to cause rutting or cracking), that is, an asphalt composition capable of improving the durability of paved roads. As a result, it is possible to provide an improved 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 can be 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 made harder and the flow resistance and abrasion resistance can be improved, 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 wear resistance (hard to cause rutting or cracking), that is, an asphalt composition capable of improving durability of a paved road. Play.

[Brief description of 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]

1 Collection tank 2 Combustion basket 3 Lostor 4 catalyst tank 5 Air balancer A raw material B melt C Wax-like substance (wax)

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-48-19618 (JP, A) JP-A-2000-169720 (JP, A) JP-A-48-56718 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L ⁷ /00-21/00 C08L 91/06 C08L 95/00 C10C 3/00

Claims (3)

(57) [Claims] 1. A saw including a rubber and wax, the wax is a synthetic resin as a raw material substance, Toka fuel
The raw material consisting of
By melting the synthetic resin,
By pyrolyzing, it becomes low molecular weight and liquefies, and they are mixed.
In order to drop the melt that is a substance into the catalyst tank in the oxygen deficient state
From the non-pyrolyzed synthetic resin and heat in the melt
Insufficient decomposition of the synthetic resin is thermally decomposed to lower the molecular weight and
A wax that is in a molten state while obtaining a wax-like substance
The flammable high-temperature gas generated by vaporizing part of the particulate matter
By burning in a burning basket,
According to the method of controlling the temperature in the sket to a predetermined temperature
A wax-like substance obtained by
Composed of formula hydrocarbon, carbon to hydrogen weight ratio (C / H)
Is 5.839 to 6.018 and is a combination of carbon and hydrogen.
The total weight% is 98.5% to 100%, and the number average molecule is
The amount (Mn) is 3.0 × 10 ^{3 to} 1.0 × 10 ⁴ ,
Weight average molecular weight (Mw) is 1.0 × 10 ^{4 to} 5.0 × 1
0 ⁴ , and Mw / Mn is 1.0 to 5.0 . Asphalt modifier. 2. The asphalt modifier according to claim 1, wherein the rubber is a recycled rubber obtained by treating a waste tire. 3. An asphalt composition comprising the modifier for asphalt according to claim 1 or 2 .