JPH0726030B2 - Asphalt mixture - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to an asphalt mixture suitable for repairing cracks in concrete structures and asphalt paved roads.

(Prior art) Conventionally, as a joint material for concrete structures, asphalt paved roads, crack repair materials, etc., molten asphalt, rubber latex mixed molten asphalt in which rubber latex is mixed with molten asphalt, or molten asphalt is dispersed in water with an emulsifier. Asphalt emulsions are commonly used.

However, since molten asphalt is cooled and solidified immediately after injection, it is not possible to fully fill the bottom of the crack, and only the area near the road surface is blocked, and the strength of the repaired portion becomes weak. There was a drawback that cracks were likely to occur again. The usable temperature range is -35 to 35 ° C.
Because of its small size, it has a problem that it is easy to melt in the summer and, on the contrary, easily cracks in cold regions.

The molten asphalt mixed with rubber latex is 10
Workability was poor because the asphalt heated to about 0 ° C was dropped into rubber latex little by little, and there was a problem that work was dangerous because it was a high-temperature substance that was sticky.

On the other hand, the asphalt emulsion has the advantages that it is easy and safe to handle, has excellent penetrability, and can fill the deep part of the crack sufficiently. On the other hand, however, the curing time is usually longer than 1 week and the water content is high, so that there is a considerable volume reduction after curing, and there are many cases where repair is required again.
There was also a problem that if there was rainfall immediately after injection, the emulsifier would separate and flow out from the cracks.

(Problems to be solved by the invention) As described above, various materials have been conventionally used as joint materials for concrete and asphalt, crack repair materials, etc. The excellent one has not been obtained yet, and its development is demanded. Moreover, with regard to the curing speed, there are cases where fast curing of about 1 minute is required depending on the application, and pot life of about 30 to 60 minutes is required. Therefore, this curing rate can be controlled. More desirable.

The present invention has been made in response to such a conventional situation, and has a fast curing rate and can be controlled so as to be applicable to various applications. It is an object of the present invention to provide an asphalt mixture sufficiently satisfying the various properties that it should have as a joint material for asphalt, a material for repairing cracks, and the like. [Structure of the Invention] (Means for Solving the Problems) The asphalt mixture of the present invention comprises (A) 0.01 to 10 parts by weight of an acid anhydride per 100 parts by weight of the solid content of an asphalt emulsion. Or (B) 0.01 to 10 parts by weight of an acid anhydride and (C) less than 100 parts by weight of an isocyanate.

The asphalt-based emulsion (A) used in the present invention is an asphalt emulsion obtained by melting an asphalt such as a natural asphalt or a petroleum asphalt, which has been emulsified with an emulsifier, or a heat-melted rubber latex. An example is a rubber-asphalt emulsion prepared by blending the above-mentioned asphalt and further emulsifying by mixing an emulsifier and a dispersion stabilizer. Generally, many asphalt emulsions of this type are sold on the market with a solid content of around 50% by weight, but in order to obtain some physical properties upon curing, the solid content should be as high as possible, preferably 70 It is more than weight%. In addition, in applications such as crack repairs on paved roads, the crack repair section constantly expands and shrinks due to heat cycles due to differences in temperature and passing of vehicles, and it is desirable to be able to follow this. Rubber compounded with latex
Asphalt emulsion is suitable. Particularly in cold regions, the use of a rubber-asphalt emulsion is indispensable because a mixture containing only asphalt becomes too hard and cracks easily. However, if the compounding amount of rubber latex is too large, it is difficult to produce in terms of emulsion stability, and the adhesion to concrete, asphalt, etc. becomes poor, so the compounding amount of rubber latex is at most the solid content. It is preferably 60% by weight or more.

In the present invention, as the asphalt-based emulsion (A), (a) an asphalt emulsion and / or a rubber-asphalt emulsion as described in detail below, and (b) at least one kind of acrylic acid compound or methacrylic acid compound It is particularly suitable to use a mixture obtained by mixing with an anionic emulsion of a copolymer having as a polymerization component from the viewpoints of curing rate, penetrability, mechanical properties of the solidified product, adhesiveness and the like. All parts by weight and weight ratios shown below are solid content conversion values.

As the asphalt emulsion of the sandaw (a), among the above-mentioned natural asphalt, petroleum asphalt, etc. that are melted and emulsified with an emulsifier, especially those that have been emulsified with an anionic emulsifier have good permeability and workability. It is excellent and preferable.

Also, as rubber and asphalt emulsion, rubber latex
100 parts by weight (hereinafter simply referred to as "part") of 100 to 1200 parts of asphalt heated and melted is mixed, and an anionic emulsifier and a dispersion stabilizer are mixed to contain water content of 8 to 35% by weight.
Anionic high-concentration emulsion (hereinafter, simply referred to as%) is suitable. Examples of the rubber latex include styrene-butadiene copolymer (SBR), vinylpyridine SBR, carboxy-modified SBR, acrylonitrile-butadiene copolymer (NBR) and the like. As the asphalt, either natural asphalt or petroleum asphalt may be used, and straight asphalt, blown asphalt, and the like may be used alone or in combination. As the emulsifier, anionic emulsifiers such as fatty acid salts, higher alcohol sulfuric acid ester salts, alkylbenzene sulfonates and rosinates are preferable. Examples of the dispersion stabilizer include bentonite and clay as an inorganic type, and polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, starch, casein and the like as an organic type. These may be used alone or in combination to improve the stability of the resulting rubber-asphalt emulsion.

The anionic emulsion (b) is prepared by mixing one or more of an acrylic acid compound or a methacrylic acid compound with other polymerization components such as styrene or vinyl acetate, which are optionally blended, water and an emulsifier. It can be obtained by adding an acidic catalyst such as ammonium persulfate to the mixed solution, stirring the mixture in warm water to polymerize it, and then neutralizing it with an alkali such as aqueous ammonia to bring the pH to more than 7 to stop the reaction. .

As the acrylic acid compound and the methacrylic acid compound,
Acrylic acid, acrylic acid ester, polyacrylic acid soda, acrylic acid monomer, acrylic acid dimethylaminoethyl ester, acrylic acid isobutyl, acrylic acid diethylene glycol ethoxylate, 2-ethoxyethyl acrylate, epoxy acrylate, n-ester acrylate, tetrahydrofuran Furyl acrylate, trimethylolpropane triacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 1,4-butanediol diacrylate,
1,6-hexanediol diacrylate, pentaerythritol triacrylate, lauriroot tridecyl (mixed) acrylate, methyl methacrylate (t-butyl methacrylate, 2-ethylhexyl methacrylate,
Tridecyl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, methacrylic acid, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, furfuryl tetramethacrylate, ethylene dimethacrylate, tetraethylene glycol dimethacrylate, dimethacrylic acid 1 There are 3,3-butylene, trimethylolpropane trimethacrylate, glycidyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-hydroxyethyl methacrylate, lauryl methacrylate and the like.

Such anionic emulsion (b) has the effect of improving the mechanical strength, adhesion, etc. of the cured product immediately after curing.

The amount of the anionic emulsion (b) to be blended is suitably in the range of 0.1 to 100 parts, and more preferably 0.5 to 20 parts, per 100 parts of the solid content of the asphalt emulsion of (a).

In order to improve mechanical properties such as elasticity of the solidified product, the asphalt-based emulsion of (A) in which the asphalt emulsion of (a) and the anionic emulsion of (b) are mixed,
A rubber latex such as SBR, vinylpyridine SBR, carboxy-modified SBR, NBR, natural rubber or the like may be blended. As the SBR latex, it is desirable to use SBR latex and carboxy-modified SBR latex alone or in combination. In the case of mixing, if the proportion of the carboxy-modified SBR latex is increased, the tensile strength and elasticity of the obtained asphalt-based emulsion after solidification will be high, so the compounding may be appropriately changed depending on the application.

The mixing ratio of the anionic emulsion (b) and the rubber latex is preferably 1: 100 to 240: 100 by weight. When such a rubber latex is blended, the weight ratio of the blending amount of the asphalt emulsion or the like of (a) to the total blending amount of the anionic emulsion and the rubber latex of (b) is 99: 1 to 70: A range of 30 is preferable.

In addition to the above components, the asphalt-based emulsion of (A) further contains an antioxidant and a plasticizer in an amount of 5% or less of the rubber component in order to improve weather resistance, cold resistance, and flexibility. Can be added in a ratio of. Examples of plasticizers include polybutene-1 and phthalate compounds (dioctylhexyl phthalate, dimethyl phthalate, etc.), aliphatic dibasic acid ester compounds (diisodecyl succinate, etc.), glycol ester compounds (diethylene glycol dibenzoate, etc.) , Fatty acid ester compounds (butyl oleate, etc.) Phosphate ester compounds (tricresyl, etc.)
Etc.

Further, as a curing accelerator, a bulking agent, or a thickening agent, alumina, magnesia, metal oxides such as iron oxide, metal powder,
Fillers such as stone powder (calcium carbonate powder), crushed stone powder, gravel, wood powder (chaff, sawdust, etc.), cement, clay and the like can be added within a range that does not impair the effects of the present invention.

The acid anhydride (B) used in the present invention includes methyltetrahydrophthalic anhydride (Me-THPA), 4-methylhexahydrophthalic anhydride (4Me-HHPA), dodecenylsuccinic anhydride (DDSA), Hexahydrophthalic anhydride (HHPA) (above, liquid at room temperature), phthalic anhydride (PA
C), maleic anhydride (MAC), succinic anhydride, butanetetracarboxylic dianhydride (BTA), bicyclo [2,2,2]-
Octo- (7) -ene-2,3,5,6-tetracarboxylic dianhydride, pyromellitic dianhydride, cyclopentanetetracarboxylic dianhydride, 3,3 ', 4,4'-benzophenone Tetracarboxylic acid dianhydride, 2,2 ', 3,3'-diphenyltetracarboxylic acid dianhydride, ethylene glycol bisanhydrotrimeritate (above, solid at room temperature), methyl endomethylenetetrahydrophthalic anhydride ( MEMTHP
A) (liquid at room temperature) etc.

As the isocyanate of (C), monovalent dodecyl isocyanate, p-isocyanatotoluene, chlorophenyl isocyanate, benzyl isocyanate (BZI), allyl isocyanate, etc., divalent tolylene diisocyanate (TDI), 4, 4'-diphenylmethane diisocyanate (MDI), 4,4'-diphenyl ether isocyanate,
3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylpropane diisocyanate, 3,3 ' -Diphenylmethane diisocyanate, 3,3'-diphenyl sulfone diisocyanate, 3,3'-diphenyl sulfide diisocyanate, hexamethylene diisocyanate (HMD
I), nonamethylene diisocyanate, 3-methyl-heptamethylene diisocyanate, 2,11-dodecane diisocyanate, 1,4-cyclohexane diisocyanate, etc., trivalent desmodur R (DD-R), desmodr DR, desmodr TH ( All of the above have the Bayer brand name). Further, these dimers and trimers, and so-called blocked isocyanates such as Corolato EH and Daltsec 2170 (above, trade name of Nippon Polyurethane Company) can also be used.

Such acid anhydrides and isocyanates react with water, which is the matrix of O / W type emulsions such as (A) asphalt-based emulsions, to convert the O / W type into W / O type, that is, water is in the asphalt. It is considered that it has the effect of phase inversion in a dispersed state and hardening. Figure 1 is a diagram showing the curing process by such phase inversion, (a) shows the dispersed state of the O / W asphalt emulsion before phase inversion, and (b) shows the action of acid anhydride and isocyanate. Shows the phase-hardened state. In the figure, 1 indicates an asphalt component and 2 indicates water.

However, the use of isocyanate alone does not cause phase inversion in a small amount, or takes time even in the case of phase inversion, and in the case of a large amount, phase inversion proceeds rapidly, but the reaction product with water causes a further decarboxylation reaction to cause oxidation. There is a problem that carbon is generated and the asphalt mixture is foamed.

Therefore, in the present invention, the acid anhydride is used alone or as a mixture with an isocyanate as described above. That is, when isocyanate is used as a mixture with an acid anhydride, foaming of the asphalt mixture due to the generation of carbon dioxide can be suppressed, and the mixing ratio with the acid anhydride and the blending with (A) into the asphalt emulsion. By adjusting the amount, it becomes possible to freely control the phase inversion time. Even when the acid anhydride is used alone, the phase inversion time can be freely controlled by adjusting the blending amount.

In the present invention, the compounding amount when the acid anhydride is used alone is 100 parts by weight of the solid content of the asphalt emulsion of (A).
The reason for limiting the content to 0.01 to 10 parts is that if it is less than 0.01 part, the phase inversion will occur very slowly and the effect due to addition cannot be sufficiently obtained.
On the contrary, when it exceeds the portion, the phase will be instantly inverted and hardened, and injection into cracks and the like becomes impossible. From the viewpoint of dispersibility in asphalt emulsion and workability, 0.1 to 5
The range of parts is more preferable.

When used in combination with an isocyanate, the amount of the isocyanate is limited to less than 100 parts per 100 parts of the solid content of the asphalt-based emulsion of (A). This is because foaming of the mixture becomes visible.

Absorbing substances such as finely powdered silica gel, activated alumina, zeolite, activated carbon, etc. also have a so-called phase inversion effect, but since they are poor in dispersibility, partial phase inversion progresses when these are used alone. However, the effects of the acid anhydride and isocyanate in the present invention cannot be obtained. These water absorbing substances can be used in combination with an acid anhydride or an isocyanate as a phase inversion aid.

The asphalt mixture of the present invention, in addition to the above components,
If necessary, an organic melt-soluble polymer substance such as polyurethane, polyamide, polyester, alkyd resin, acrylic resin, polyvinyl chloride, epoxy resin,
Silicone resin, polyvinyl acetate, etc. can be added. By adding such an organic solvent-soluble polymer substance, it is possible to improve the mechanical properties, adhesive strength, etc. of the cured product, and it is also possible to control the curing speed.

To obtain the asphalt mixture of the present invention, (B) acid anhydride, or (B) acid anhydride and (C) isocyanate may be added as they are to an (A) asphalt emulsion prepared in advance and mixed. Alternatively, the acid anhydride or isocyanate may be dissolved or dispersed in a solvent in advance and then added to the (A) asphalt-based emulsion.

When the above-mentioned organic solvent-soluble polymer substance is added, it is possible to dissolve the acid anhydride of (B) or the isocyanate of (C) or the acid anhydride of (B) and the isocyanate of (C) in an organic solvent. Make sure to add it by mixing with the mixture.

When the asphalt admixture of the present invention is injected and filled in a cracked portion of a road, each component may be mixed as described above immediately before the injection and the mixture may be injected into the cracked portion by a nozzle, a hose or the like. The (A) asphalt-based emulsion containing the anionic emulsion of (b) has a curing action on the asphalt emulsion which is the main ingredient of the (b) anionic emulsion depending on the conditions. When the (A) asphalt-based emulsion is prepared by blending an anionic emulsion, it is desirable to keep it sealed until just before use so that the curing action is not exhibited.

The asphalt mixture of the present invention thus injected,
As shown in the above drawing, the asphalt emulsion is (a)
The phase inverts from the O / W type having water 2 as a matrix to the W / O type having (b) asphalt component 1 as a matrix, and the whole is quickly cured with uniform and sufficient mechanical strength. After that, with the lapse of time, the water 2 inside is volatilized to completely cure (C), and a solidified body having excellent properties such as mechanical properties is formed. The mechanical properties of the cured product immediately after phase inversion of (b) reached almost 70% of that of (c), and rainfall,
It cures sufficiently to the extent that it does not hinder the running of cars.

By the way, the (A) asphalt-based emulsion alone does not undergo hardening due to such phase inversion, and the chemical or physical action causes the emulsion to lose its electric charge balance and decompose, causing water to evaporate and finally cure. Since it takes the form of so-called decomposition hardening, it takes several days at the earliest to have almost 70% of the mechanical properties of full hardening.

Note that the time required for phase inversion curing depends not only on the type of acid anhydride or isocyanate, the blending amount and mixing ratio of these, the blending of the above-mentioned polymer substance, etc., but also the ambient temperature as shown in the following examples. Since it changes, it is necessary to consider the construction environment temperature. That is, the composition is selected as appropriate so that the desired curing time can be obtained from the construction environment temperature.

(Operation) As described above, the asphalt mixture of the present invention is foamed as in the case of using the isocyanate alone by adding the acid anhydride or the mixture of the acid anhydride and the isocyanate in a predetermined ratio to the asphalt emulsion. Without doing so, the asphalt-based emulsion undergoes phase inversion from the O / W type having water as a matrix to the W / O type having an asphalt component as a matrix, and the whole is rapidly cured with uniform and sufficient mechanical strength. Moreover, the phase inversion curing time can be controlled by adjusting the composition.

In addition, it is possible to reliably fill even deep insides of deep cracks such as road surfaces without impairing the original permeability and ease of handling of the asphalt emulsion.

When an asphalt emulsion obtained by mixing an asphalt emulsion and / or a rubber / asphalt emulsion with an anionic emulsion of a specific copolymer is used, the strength, rubber elasticity, adhesive strength, etc. of the cured product can be reduced. The physical properties are further improved.

(Example) Hereinafter, the Example of this invention is described.

Examples 1-32 Asphalt admixtures were prepared by mixing the components in the formulations shown in Tables 1 and 2. The components used were adjusted as follows.

Rubber / asphalt emulsion: SBR latex (solid content: 50%) is poured into asphalt that has been melted by heating, and an anionic surfactant and dispersion stabilizer are added and stirred to disperse.

Copolymer Emulsion B: 10 parts of cyclohexyl methacrylate monomer and 10 parts of styrene monomer are dissolved in 20 parts of water and 4 parts of surfactant are added.
Parts, 1 part of ammonium persulfate as a polymerization catalyst was added,
After stirring at 80 to 85 ° C for 6 hours to polymerize, ammonia water was poured in to adjust the pH to 8.5.

Copolymer emulsion C: 10 parts of butyl methacrylate monomer and 10 parts of styrene monomer are dissolved in 20 parts of water, 4 parts of surfactant and 1 part of ammonium persulfate as a polymerization catalyst are added, ℃
After stirring for 6 hours to polymerize, pour in ammonia water
Adjusted to pH 8.5.

For comparison, as shown in Comparative Example in Table 2, only the components constituting the asphalt-based emulsion (A) were mixed without adding any acid anhydride or isocyanate, and Comparative Example 1
A blend of ~ 7 was prepared.

Next, various tests were conducted on the asphalt admixtures obtained in Examples and Comparative Examples by the following method.

Phase inversion solidification time: 30 g of a sample was placed in a plastic container having a volume of 200 cc, and the time required for phase inversion hardening at each temperature of 0, 10, 20, 30 ° C. was measured. For the comparative examples, the time to normal cure was measured.

Tensile strength and elongation: According to JIS K 2207, injection was carried out at 20 ° C., and one week later, measurement was performed.

Adhesive strength: By placing two bar spacers with a diameter of 1 mm in parallel between two blocks of 50 mm x 50 mm x 50 mm asphalt concrete, a gap of 1 mm is provided, and the sample is filled in this gap, and at 30 ° C. After curing for 6 days at a temperature of 23
The adhesive strength was measured under conditions of ℃ and test speed of 1 mm / min.

The results of these measurements are shown in the lower columns of Tables 1 and 2.

As is clear from the table, the asphalt mixture of the present invention has a significantly shortened curing time as compared to the asphalt emulsion alone, and the type of compounding ingredients, the compounding ratio, etc. are taken into consideration in the construction environment temperature. Then, the curing time can be easily adjusted by appropriately selecting.

Further, in the case where the anionic copolymer emulsion is blended, the mechanical properties of the cured product are improved as compared with the case where it is not blended.

[Effects of the Invention] As described above, since the asphalt mixture of the present invention is added with an acid anhydride or a mixture of an acid anhydride and an isocyanate in an asphalt-based emulsion, foaming occurs as in the case of using an isocyanate alone. As a result, a phase inversion occurs in the asphalt emulsion, and the whole quickly and uniformly hardens with sufficient mechanical properties. Therefore, the problems associated with rainfall immediately after injection and running of the vehicle are solved. Moreover, the phase inversion curing time can be controlled by adjusting the composition, and the curing time can be set according to the application.

In addition, it has excellent permeability and is easy to handle, and it is possible to reliably fill even deep insides of deep cracks such as road surfaces.

When an asphalt emulsion obtained by mixing an asphalt emulsion and / or a rubber / asphalt emulsion with an anionic emulsion of a specific copolymer is used, the strength, rubber elasticity, adhesive strength, etc. of the cured product can be reduced. The physical properties are further improved.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the curing process of the asphalt mixture of the present invention. 1 ... Asphalt component 2 ... Water

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichiro Fukai 9-1-7 Kashiwaoka, Makomanai, Minami-ku, Sapporo-shi, Hokkaido (72) Inventor Etsuo Hosokawa 2-1-1, Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa Showa Electric Power Company (72) Inventor Takeo Shiono 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Showa Electric Cable Co., Ltd. (72) Inventor Masatada Fukushima 2-1-1 Oda, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 Showa Cable Denki Co., Ltd. (72) Inventor Nobuyuki Sukegawa 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture No. 1 Showa Cable Denki Co., Ltd. (72) Junichi Nishioka, Sakae Oda, Kawasaki-ku, Kanagawa Prefecture 1st-1st Showa Electric Wire & Cable Co., Ltd. (72) Inventor Ryo Shimizu 2-1-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa Showa Electric Cable Inside

Claims (4)

[Claims] 1. An asphalt mixture comprising (A) 0.01 to 10 parts by weight of an acid anhydride per 100 parts by weight of a solid content of an asphalt-based emulsion. 2. (A) 0.01 to 10 parts by weight of an acid anhydride and (C) per 100 parts by weight of the solid content of the asphalt emulsion.
An asphalt mixture characterized by being blended with less than 100 parts by weight of isocyanate. 3. The (A) asphalt-based emulsion according to claim 1,
(A) an asphalt emulsion and / or a rubber / asphalt emulsion, and (b) a mixture of an emulsion of a copolymer containing at least one acrylic compound or methacrylic acid compound as a polymerization component. Characteristic asphalt mixture. 4. The (A) asphalt-based emulsion according to claim 2,
(A) an asphalt emulsion and / or a rubber / asphalt emulsion, and (b) a mixture of an emulsion of a copolymer containing at least one acrylic compound or methacrylic acid compound as a polymerization component. Characteristic asphalt mixture.