JPS6123647A - Reactive rubber/asphalt mixture - Google Patents

Abstract

PURPOSE:The titled mixture which has excellent dynamic stability and abrasion resistance, can make efficient use of the waste asphalt paving material, and is useful in eliminating pollution due to waste material, which comprises a moisture-curing liquid diene rubber and a reclaimed compound material. CONSTITUTION:The waste asphalt paving material which has been crushed to a diameter of about 100cm or smaller, 1-20wt% (of the asphalt) mineral oil having a kinematic viscosity of 20-5,000cSt (40 deg.C) and a flash point of 150 deg.C or higher as a softening agent, and if necessary, a peeling inhibitor, a pour point depressant, a surface active agent, etc. are mixed by stirring at 80-220 deg.C to give a reclaimed compound material (A). A polybutadiene homopolymer, etc. having reactive hydroxyl groups on both ends of the basic skeleton is reacted with a polyisocyanate to give a moisture-curing liquid diene rubber (B) which has a molecular weight of 500-50,000 and contains isocyanate groups (blocked with enol groups) on both ends of the basic skeleton. Then component A and component B in an amount of 1-20wt% based on the total of the asphalt and softening agent in component A are mixed to give the titled mixture.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a reactive rubberized asphalt mixture,
More specifically, the present invention relates to a reactive rubberized asphalt mixture that effectively utilizes asphalt pavement waste material, has properties equivalent to rubberized asphalt obtained from fresh asphalt, and is suitable for, for example, road pavement.

[Prior Art] Conventionally, a reactive rubberized asphalt mixture containing fresh asphalt and a moisture-curable diene liquid rubber has been proposed for road paving (Japanese Patent Publication No. 5621/1983). The reactive rubberized asphalt provides a road surface paved with the rubber elasticity that has significantly improved resistance to both low-temperature embrittlement of the pavement in cold regions and flow deformation of the pavement in high-temperature regions. It is an excellent composition that exhibits the following properties.

[Problems to be solved by the invention] In recent years, roads that have been in use for many years have been replaced with old asphalt concrete pavements that have been removed and resurfaced, or parking lots have been demolished. is emitted in large quantities. Traditionally, such asphalt pavement waste materials were dumped and used in landfills in the sea or in fields, but since they were designated as industrial waste in 1971, they cannot be dumped anywhere indiscriminately, and their effectiveness is limited. Use is desired.

However, asphalt pavement waste material has become hard due to changes over time during its use.
It cannot be reused as is. Therefore, in order to make this asphalt pavement waste material usable as Fr, a recycling method has been proposed (Japanese Patent Laid-Open No. 57-11608
Although the recycled asphalt pavement waste material is slightly softer, its dynamic stability and abrasion resistance deteriorate in summer, making it unsatisfactory as a material for road resurfacing. isn't it.

Therefore, at present, there is no material for road pavement that uses asphalt pavement waste and has properties equivalent to the reactive rubberized asphalt mixture described in the above-mentioned Japanese Patent Publication No. 59-5621. Recycling of waste materials has not yet been achieved.

[Means for Solving the Problems] Based on the above circumstances, the present invention makes it possible to effectively utilize asphalt pavement waste materials, and in addition, despite using asphalt pavement waste materials, fresh asphalt is not moisture-cured. This material was developed for the purpose of developing a material for road pavement, for example, which has excellent dynamic stability and abrasion resistance comparable to those using a mixture of diene liquid rubber. That is, the present invention is a reactive rubberized asphalt mixture characterized by containing a moisture-curable diene-based liquid rubber and a recycled composite material, particularly a moisture-curable diene-based liquid rubber, asphalt pavement waste material, and a softening agent. A reactive rubberized asphalt mixture containing:

Moisture-curable diene-based liquid rubber in this invention includes polybutadiene, styrene-butadiene copolymer, styrene-butadiene-styrene copolymer, polyisoprene, styrene-isoprene copolymer, polypentadiene, acrylonitrile-butadiene copolymer. The basic skeleton is selected from polychloroprene, isobutylene-isoprene copolymer, copolymer of butadiene and methacrylate of a higher alcohol having 2 to 15 carbon atoms, and isocyanate is attached to both ends of the basic skeleton. Liquid rubbers having isocyanate groups blocked with groups or phenolic groups can be used. These liquid rubbers can be produced, for example, by reacting polyisocyanate with polybutadiene homopolymer, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, etc., which have reactive hydroxyl groups at both ends of the basic skeleton. I can do it. The preferred molecular weight of this moisture-curable diene liquid rubber is 500-50,000, with a particularly preferred molecular weight of 600-8,000.

Among the moisture-curable diene liquid rubbers, a liquid rubber obtained by reacting the terminal allyl hydroxyl group of liquid polybutadiene with a diisocyanate is particularly preferred. Preferred examples of the diisocyanate include diphenylmethane diisocyanate, toluene diisocyanate 1., and hexamethylene diisocyanate.

The moisture-curable diene liquid rubber of the present invention is capable of curing by absorbing a small amount of water, such as moisture in the air, without using a separate curing agent.

This is its major feature. That is, a crosslinking reaction is initiated by absorbing moisture, and the resulting cured product usually has rubber elasticity, as in the case of vulcanized rubber.

As described above, the moisture-curable diene-based liquid rubber used in the present invention requires moisture as a condition for the crosslinking or curing reaction, but not heating. Therefore, this curing reaction is not affected by the heating temperature when the reactive rubberized asphalt mixture according to the present invention is spread on the road surface, so that the rolling operation of the reactive rubberized asphalt mixture can be carried out suitably.

Instead, it is important that the moisture-curable diene liquid rubber is sufficiently protected from moisture before being mixed with the recycled composite material. That is, it is necessary to shield this moisture-curable diene-based liquid rubber from surrounding moisture with a moisture-proof member. As a means for this purpose, it is recommended to encapsulate this moisture-curable diene liquid rubber in a moisture-proof synthetic resin film.

In this case, the synthetic resin film is moisture-proof, and the recycled composite material and the moisture-curable diene-based liquid rubber are mixed and heated so that the synthetic resin film is immediately heated to the melting temperature of the asphalt in the recycled composite material. It must be meltable. The asphalt in recycled composite materials is usually heated from 80°C to 2°C.
Since the resin is heated and melted at 20° C., a synthetic resin that melts in the above temperature range is selected. Examples of such synthetic resins include thermoplastic resins such as polyethylene, polypropylene, and polyvinyl chloride.

Of course, the method of protecting moisture-curable diene-based liquid rubber from moisture in the present invention is not limited to covering it with the synthetic resin film. Store it naked in a container and heat it to 60-80℃ beforehand! A similar purpose can also be achieved by heating the mixture to 100 ml and mixing it with a softener or aromatic solvent.

As the recycled composite material in this invention, a mixture of asphalt pavement waste and a softener can be used. The mixture of asphalt pavement waste and softener preferably has a penetration degree adjusted to 40 to 1OO.
If the penetration is less than 40, the workability of the composite material produced will be very poor, and if the penetration is greater than 100, the dynamic stability of the reactive rubberized asphalt mixture will be poor. It may happen.

As the asphalt pavement waste material, any mixture of asphalt and aggregate that is normally discharged from construction sites such as asphalt paved roads can be used.

The aggregates in the asphalt pavement waste are those commonly used in the production of asphalt pavement materials, such as crushed stone No. 5; 0-20%, crushed stone No. 6; 10-50%, crushed stone No. 7; 5-30%, coarse sand: 10-30%, screening; 5-20%, fine sand: 5-20%, stone powder, 1-10
Aggregate mixtures consisting of % can be used.

Mineral oil can be used as the softener. Mineral oils that can be used include, for example, extra-rough I., lubricating oil fractions, thermal cracking residues, boiling fractions of catalytically cracked gas oils,
Highly aromatic, low-boiling, low-volatility petroleum fractions, such as pyrolysis residues of residual petroleum fuel oils used in the production of gas, etc., and highly aromatic extracts of distillates used in the production of lubricating oils. Can be mentioned.

Classified by component, usable mineral oils include, for example, aromatic mineral oils, naphthenic mineral oils, and paraffinic mineral oils.

Among the above-mentioned mineral oils, aromatic mineral oils are particularly preferred, and those having a kinematic viscosity of 20 to 5000 C3T (40°C) and a flash point of 150°C or higher are preferred.

The content of the mineral oil is preferably 1 to 20% by weight based on the asphalt in the asphalt pavement waste material. If the content of the mineral oil is less than 1% by weight, the penetration of the recycled mixture becomes too small, and if it exceeds 20% by weight, the dynamic stability of the rubberized asphalt mixture obtained becomes poor.

When mixing the asphalt pavement waste with the softener, it is preferable to sufficiently divide the asphalt pavement waste into small pieces. The method for subdividing this asphalt pavement waste material is not particularly limited, and conventionally known methods can be used. The degree of fragmentation of this asphalt pavement waste material is preferably a particle size of 10C11 or less, particularly 50 layers or less. To make the asphalt pavement waste easier to fragment, it can be treated with steam or hot water. This treatment loosens the asphalt pavement waste and allows smooth mixing with the softener.

There are no particular limitations on the method of mixing the asphalt pavement waste and the softener, but for example, a stirring and mixing device such as a rotary kiln or mixer can be used as appropriate.

The heating temperature when mixing the asphalt pavement waste and the softener is usually 80 to 220°C, preferably 120 to 180°C.
It is ℃. If the heating temperature is lower than 80°C, the asphalt pavement waste and the softener will not be sufficiently mixed, and if the heating temperature is higher than 220°C, the asphalt pavement waste and the softener will not only decompose and deteriorate due to the heat. It is also unfavorable from a safety and health standpoint.

When combining asphalt pavement waste with a softener, anti-peeling agents such as alkylamines, surfactants such as imidacillin compounds, chlorinated paraffin condensates,
Pour point depressants such as polyalkyl methacrylate may be added. These anti-peeling agents, surfactants, pour point depressants, etc. may be added to a softening agent, such as mineral oil, in advance, and the resulting mixture and asphalt pavement It may also be mixed with waste materials.

There are no particular limitations on the method of mixing the moisture-curable diene-based liquid rubber and the recycled composite material, but a stirring and mixing device such as a rotary kiln or mixer can be used as appropriate. Then, the stirring and mixing device used for mixing the asphalt pavement waste and the softener can be used as is, and the moisture-curing diene liquid rubber is added to the stirring and mixing device that accommodates the recycled composite material. , which is preferable in terms of work efficiency.

In addition, moisture-curable diene liquid rubber may be dropped into a stirring mixing device as it is, or may be partially diluted with a softener or aromatic solvent before being dropped. Alternatively, the mixture may be wrapped with a synthetic resin film and placed in the stirring/mixing device.

1 liter of mixture of moisture-curable diene liquid rubber and recycled composite material
i4 L, the amount of the moisture-curable diene liquid rubber blended so that the moisture-curable diene liquid rubber is 1 to 20% by weight relative to the total amount of asphalt and a softener, such as mineral oil, in the asphalt pavement waste material. If the amount of the moisture-curable diene liquid rubber is less than 1% by weight, the resulting cured product of the reactive rubberized asphalt mixture, for example, the dynamic stability of the paved surface will deteriorate, and ,2
If it is more than 0% by weight, the abrasion resistance of the paved surface may deteriorate. Therefore, when mixing the moisture-curable diene-based liquid rubber and the recycled composite material, an appropriate amount of fresh asphalt may be added to adjust the amount of the moisture-curable diene-based liquid rubber within the above range. good.

The heating temperature when mixing the moisture-curing diene-based liquid rubber and the recycled composite material is usually 120-180''. Therefore, the moisture-curable diene-based liquid rubber and the recycled composite material can be sufficiently mixed under heating in an agitating mixer.

Reactive rubberized asphalt a obtained as described above
Compounds are used, for example, in road paving. During paving, this reactive rubberized asphalt mixture is compacted at a temperature usually in the range of 100 to 140"°C. The reactive rubberized asphalt mixture according to the invention can advantageously carry out the compaction process. For example, as long as the compaction temperature is 100°C or higher, there is no risk of moisture being absorbed into the reactive rubberized asphalt mixture, and therefore, the curing reaction of the moisture-curable diene-based liquid rubber progresses during the compaction process. This is because it is possible to perform sufficient compaction without having to do so.

After rolling, the curing of this reactive rubberized asphalt (IR) compound must be completed in as short a time as possible.

After the rubberized asphalt mixture according to the present invention is compacted, the temperature of the resulting pavement rapidly increases to 100%.
As the temperature decreases, the pavement begins to absorb moisture, and the pavement hardens within a short period of time.

According to the inventor's experiments, the curing reaction was almost completed within 24 hours. Thus, while using asphalt pavement waste material, a pavement body with excellent rubber elasticity can be obtained by carrying out the same construction work as when using a normal asphalt mixture.

Since it does not use asphalt pavement waste as a raw material, it is a reactive rubberized asphalt with such curing conditions.
The JM compound has never been manufactured before in history, and in this sense it can be said to be a completely new product in itself.

[Example] Next, Examples and Comparative Examples of the present invention will be shown to further specifically illustrate the present invention.

(Example 1) 6% by weight of asphalt and 94% by weight of aggregate (crushed stone No. 6: 4
0% by weight, crushed stone No. 7; 20% by weight, coarse sand; 16% by weight,
Screening, 11% by weight, fine sand: 8% by weight, stone powder;
Asphalt pavement waste material IT, which had been cured over time to a penetration degree of 20 consisting of 5% by weight), was subdivided. This finely divided asphalt pavement waste material was heated to 150° C. for 30 minutes in a rotary kiln. Next, mineral oil [trade name AE-5
0, manufactured by Idemitsu Kosan, kinematic viscosity 51.22C3T (40℃)
] 33 kg (5% by weight based on the asphalt) was put into the rotary kiln, and the asphalt pavement waste and the mineral oil were mixed for 1 minute to produce a recycled composite material.

Thereafter, liquid polybutadiene crude MDI (4,4°-diphenylmethane diisocyanate) prepolymer having a molecular weight of 2800 is gradually added to the rotary kiln in an amount of 4% by weight based on the total amount of asphalt and the mineral oil. The prepolymer and the recycled composite material were stirred and mixed while heating at 6.150° C. to obtain a reactive rubberized asphalt compound.

(Examples 2 to 6) The reaction was carried out in the same manner as in Example 1, except that the same types of mineral oil and prepolymer as in Example 1 were used, and the amounts of these were changed to the values shown in Table 1. A mold rubberized asphalt mixture was obtained.

The reactive rubberized asphalt mixtures obtained in Examples 1 to 6 were transported to the construction site and immediately subjected to compaction work. The surface temperature of this reactive rubberized asphalt mixture at the start of rolling was 165°C, and at the end of rolling it was 1
The temperature was around 30°C.

During the rolling process, the temperature of the reactive rubberized asphalt compound was over 100°C, so absorption has not yet occurred, and therefore the curing reaction has not progressed, making the rolling process extremely easy. We were able to complete sufficient compaction.

The above rolling conditions are the same as those for normal rolling of asphalt mixtures. As the surface temperature of the pavement hardened to 100° C. or lower after the compaction work was completed, the hardening reaction of the reactive rubberized asphalt mixture proceeded.

The cured product of this reactive rubberized asphalt mixture was evaluated for dynamic stability by a wheel tracking test and for wear resistance by a labeling test in a laboratory.

(A) Wheel tracking test The flow deformation resistance of asphalt mixtures at high temperatures is generally conducted by the British Transport and Road Research Institute (TRRL).
It is evaluated by the so-called wheel tracking test developed by. This wheel tracking test was also applied to the cured product of the reactive rubberized asphalt mixture according to the present invention.

This test simulated the "ruts" caused by heavy vehicle running on actual roads and the kneading effect caused by repeated vehicle running, and tested the cured product at high temperatures (60°C).
) was evaluated. The results are shown in Table 1.

(B) Labeling Test According to Asphalt Pavement Guidelines 4-13, wheels to which chains were fixed radially were rotated on the surface of the cured product under certain conditions, and the amount of wear on the surface at that time was measured. The results are shown in Table 1.

(Comparative Example 1.2) Crew FMD of liquid polybutadiene with 12800 molecules
A pavement was obtained in the same manner as in Example 1, except that the I (4,4'-diphenylmethane diisocyanate) prepolymer was not used. Abrasion resistance was evaluated.

(Comparative Example 3) Fresh asphalt 6 with a penetration degree of 70 was used instead of recycled composite material.
Weight% and aggregate 94% by weight (crushed stone No. 6; 40 weight 111.%
, crushed stone No. 7; 20% by weight, coarse sand, 16% by weight, screening; l1% by weight, fine sand: 8% by weight, stone powder; 5% by weight
) A pavement was obtained in the same manner as in Example 1, except that an asphalt paving material consisting of was evaluated. As a result, the dynamic stability was 1 oaoo, and the wear-resistant cross-sectional area was 0.23.

As is clear from Table 1, although the reactive rubberized asphalt mixture according to the present invention uses asphalt pavement waste, it is dynamically stable by blending mineral oil and moisture-curable diene-based liquid rubber. It can be cured into a pavement with excellent hardness and wear resistance at the same time.

Further, as is clear from Comparative Example 3, the reactive rubberized asphalt mixture according to the present invention is a rubberized asphalt mixture obtained by mixing an asphalt paving material using fresh asphalt and a moisture-curable diene-based liquid rubber. It can be cured into a cured product having dynamic stability and wear resistance comparable to that of a cured asphalt mixture.

(Hereinafter, blank space) [Effects of the Invention] As detailed above, according to the present invention, a recycled composite material obtained by adding a softener to asphalt pavement waste and a moisture-curable diene liquid rubber are mixed. This reactive rubberized asphalt mixture has a dynamic stability and abrasion resistance that is close to that of the pavement obtained by curing a rubberized asphalt mixture obtained by mixing fresh asphalt and a moisture-curable diene-based liquid rubber. It can be cured into a pavement with properties. Therefore, with this invention, it is possible to effectively utilize asphalt pavement waste materials discharged in large quantities from construction sites, etc., to eliminate waste pollution, and to solve two problems faced by asphalt pavement roads, namely, low temperatures in cold regions. The two problems of embrittlement on the one hand and flow deformation in high temperature zones on the other hand can be solved simultaneously with the same product. Furthermore, since the reactive rubberized asphalt mixture according to the present invention is not a so-called "two-component type" like the liquid rubber or epoxy found in Japanese Patent Publication No. 43-22319, but a "one-component type", It is extremely easy to handle and practical. This reactive rubberized asphalt mixture is cured by moisture, so
It does not harden when heated for road paving, and paving work can be carried out reliably.

Patent applicant: Idemitsu Petrochemical Co., Ltd. Procedural amendment July 23, 1985

Claims (7)

[Claims] (1) Reactive rubberized asphalt mixture characterized by containing moisture-curable diene-based liquid rubber and recycled composite material (2) The moisture-curable diene liquid rubber is polybutadiene, styrene-butadiene copolymer, styrene-butadiene-styrene copolymer, polyisoprene, styrene-isoprene copolymer, polypentadiene, acrylonitrile-butadiene copolymer. , polychloroprene, isobutylene-isoprene copolymer, butadiene and 2 carbon atoms
The basic skeleton is selected from copolymers of higher alcohols with methacrylates having 15 to 15 carbon atoms, and has isocyanate groups blocked with isocyanate groups or phenol groups at both ends of the basic skeleton. Reactive rubberized asphalt mixture according to item 1. (3) The reactive rubberized asphalt mixture according to any one of claims 1 and 2, wherein the moisture-curable diene liquid rubber has a molecular weight of 500 to 50,000. (4) The reactive rubberized asphalt mixture according to any one of claims 1 to 3, wherein the recycled composite material contains asphalt pavement waste and a softener. (5) The reactive rubberized asphalt mixture according to claim 4, wherein the softener is mineral oil. (6) The reactive rubberized asphalt mixture according to claim 5, wherein the mineral oil is contained in an amount of 1 to 20% by weight based on the asphalt in the asphalt pavement waste. (7) The moisture-curable diene-based liquid rubber may be added to
Claim 4 contained in a blending ratio of 20% by weight
Reactive rubberized asphalt mixture according to any one of items 6 to 6.