JP2647831B2 - Bituminous emulsion - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an oil-in-water type bitumen emulsion, and more particularly, to the properties of bitumen emulsion: emulsion stability, mixability with aggregate, decomposition time control, adhesion. The present invention relates to a bitumen emulsion having an excellent anti-stripping effect.

[Conventional technology and problems]

Bituminous substances such as asphalt, tar and pitch obtained from petroleum or coal are emulsified for imparting workability and widely used for paving materials, waterproof adhesive materials, railway tracks and the like.

Bituminous emulsions are classified into three types, anionic emulsions, cationic emulsions, and nonionic emulsions, depending on the type of emulsifier (surfactant) used. It can be broadly classified into slow-degradable emulsions used by mixing with aggregates.

In any case, since the bituminous material that is regenerated by breaking the emulsion acts as a binder between the aggregates, the function of adhering to the aggregates is extremely important. However, anionic emulsions and nonionic emulsions have the advantage of good mixing with the aggregate, but have the major disadvantage of poor adhesion to the aggregate. On the other hand, the cationic emulsion imparts an adhesive function by exerting an electric attractive force between the bitumen-dispersed particles and the aggregate, but is not yet practically sufficient, and there is a demand for an improvement measure.

Furthermore, it is important that the slow-degradable emulsion used in combination with the aggregate has good mechanical and forced stirring and mixing stability, and that it does not decompose during construction such as transportation, laying, and compaction. It must satisfy the conditions that it decomposes to some extent and has excellent adhesion, and that such properties are not affected by the type of aggregate and the temperature during construction. As a countermeasure, use a large amount of an emulsifier, or use a multi-component emulsifier, or a water-soluble organic polymer such as polyvinyl alcohol, gelatin, methyl cellulose,
A method of adding polyacrylamide, guar gum, or the like as a protective colloid has been widely considered. However, although the bitumen emulsion is stabilized, it does not have the effect of improving the properties of the aggregate-bituminous interface and essentially improving the adhesion to the aggregate.

In addition, various methods have conventionally been devised to improve the mixing property and adhesion performance of the bituminous emulsion. For example, according to Japanese Patent Publication No. 49-6174, a polyhydric alcohol fatty acid partial ester is used, but the mixing stability of the aggregate is improved, but the adhesiveness and the peel resistance by the intervention of water are insufficient. It is.

In addition, Japanese Patent Publication No. 56-4588 discloses a method in which a saturated higher fatty acid is added to bituminous material to improve the mixing property and adhesion, but in this case, a combination with a cationic emulsifier is mainly used, It cannot be used in a compounding system mixed with cement or iron ore slag showing the following.

Furthermore, a composition using a large amount of a water-soluble polymer and a water-soluble inorganic salt is disclosed and proposed in Japanese Patent Application Laid-Open No. 57-42763. However, when the bituminous emulsion is decomposed and regenerated into the original bituminous material, a large amount of inorganic salt remains in the bituminous material, so that the original elongation of the bituminous material is significantly reduced and the binder properties are lost.

Moreover, in recent years, while there is a concern that the quality of asphalt for roads and aggregates will deteriorate, the use of recycled materials is also being considered, but good mixing properties and strong adhesion cannot be expected, and asphalt emulsion modification is not possible. It is strongly desired. However, no means has yet been developed to eliminate all of the above-mentioned problems and various performances required by the market.

[Means for solving the problem]

The present inventors have conducted intensive studies to obtain an ideal bitumen emulsion having excellent emulsion stability, aggregate mixing properties and aggregate adhesion. As a result, when emulsifying bitumin, an emulsifier (surfactant) was used. When tannic acid or a tannin compound is added to the aqueous solution and compounded, the tannic acid or the tannin compound exhibits complex effects such as an emulsifying aid effect, a protective colloid effect of the particles, and an affinity effect of the bitumen particles for aggregate attachment, and has excellent physical properties. It was found that a bitumen emulsion having the following formula was obtained, and the present invention was completed.

That is, the present invention is a bituminous emulsion comprising 40 to 80 parts by weight of bitumen, 60 to 20 parts by weight of water, 0.01 to 10.0 parts by weight of a surfactant, and 0.01 to 5.0 parts by weight of tannic acid or a tannin compound. It is related to.

Tannic acid or tannin compound used in the present invention,
A polyphenolic complex compound having a large hydrophobic group (benzene skeleton) and many -OH groups at the same time, which is a necessary condition for achieving the effects of the present invention. As the tannic acid or tannin compound used, for example, Quebracho belonging to the family Urushi, depujito, tannic acid from China,
Examples thereof include Turkish tannic acid, hamameli tannic acid, kebulinic acid, smack tannin, pentaploid tannin, eragic acid tannin and the like, and purified tannic acid thereof. The amount used is 0.01 to 40 to 80 parts by weight of bituminous material.
The amount is from 5.0 to 5.0 parts by weight, preferably from 0.1 to 1.0 part by weight. A bitumen emulsion having excellent aggregate mixing property and aggregate adhesion can be prepared only by adding such a small amount.

In the present invention, as a method of adding and mixing tannic acid or a tannin compound, a bitumen emulsion may be prepared by previously dissolving in a surfactant aqueous solution (emulsion liquid) and emulsifying bituminous substances. It may be added and mixed later to a bitumen emulsion obtained by emulsifying the aqueous solution of the agent and bituminous material. That is,
Besides the method of emulsifying bitumin by adding and dissolving it in an aqueous surfactant solution, surprisingly, it is only necessary to add and mix it to the already prepared bituminous emulsion for rapid decomposability (for spraying). Another major feature is that it can be converted and prepared for mixing aggregate.

The effect of the addition of tannic acid or a tannin compound is due to the structure of a surfactant having a hydrophobic skeleton and a hydrophilic group at the same time. It is considered that the protective layer is formed by the hydration structure of the -OH group, and the particles are stabilized, and do not rapidly decompose even when mixed with aggregate. On the other hand, most of the aggregate surface in the moisture absorption state has -OH groups, and hydrogen bonds are formed between tannic acid and many -OH groups of the tannin compound, resulting in strong adhesion with physical adsorption. It can be inferred that it shows sex.

Therefore, a compound having a large hydrophobic skeleton and a large number of -OH groups is necessary to realize the effect, sorbitol, ethylene glycol, benzenediol, polyhydric alcohols such as benzenetriol, polyether polyols, sugars, Compounds such as ligninsulfonic acid are not effective for adhesive function.

In the present invention, as bituminous petroleum straight asphalt, semi-blown asphalt, cutback asphalt, natural asphalt, petroleum tar, pitch,
Solvent deasphalted asphalt, heavy oil, etc., and one or more mixtures thereof. Furthermore, modified rubbers such as natural rubber, styrene-butadiene copolymer, synthetic rubber such as chloroprene copolymer, and high molecular polymers such as polyethylene, ethylene-vinyl acetate copolymer, petroleum resin, and thermoplastic resin can also be used. . In addition, inorganic fillers and organic fillers such as calcium carbonate, slaked lime, cement, and activated carbon, petroleum softeners, vegetable oil softeners, various plasticizers, and sulfur can be added as required.

The surfactant used as a bituminous emulsifier may be any of nonionic, anionic, cationic and amphoteric surfactants, and may be one or two or more multicomponent systems. Here, in the case of a cationic emulsifier that is not a quaternary salt,
Hydrochloric acid, acetic acid, nitric acid, sulfamic acid, dimethyl sulfate and the like are used in the form of each acid salt. The amount of the surfactant to be used is 0.01 to 10.0 parts by weight, particularly 0.1 to 40 parts by weight of bituminous substance.
An appropriate amount is 05 to 5.0 parts by weight. 45 of these surfactants
Dissolved in warm water of ℃ ~ 80 ℃ to make an emulsion, this and 120 ℃
The bitumen melted at ~ 180 ° C is simultaneously passed through a homogenizer or a colloid mill to produce a bituminous emulsion. The mixing ratio of the emulsion and bitumin in the bitumen emulsion is
~ 20 parts by weight, preferably 50-30 parts by weight, bituminous 40
-80 parts by weight, preferably 50-70 parts by weight.

In addition, in practical use such as the purpose of use, construction method, etc., water-soluble inorganic salts such as ammonium chloride, calcium chloride, aluminum chloride, and iron chloride, and water-soluble polymers such as polyvinyl alcohol, gelatin, polyethylene glycol, methyl cellulose, and cationic starch are appropriately selected. They can be used together.

〔The invention's effect〕

As described in detail above, bituminous materials, surfactants, and additives are appropriately selected, and tannic acid or a tannin compound is added and blended to prepare an emulsion.
The present inventors' experiments have shown for the first time that a bituminous emulsion that satisfies all of the properties required by the market for aggregate adhesion, storage stability, freeze stability and low foamability can be obtained.

Therefore, such bituminous emulsions are used for road paving, railway tracks, cement asphalt mortar, corrosion protection, rust prevention,
It can be effectively used for applications such as waterproofing, adhesives, and agricultural land improvement materials.

〔Example〕

Next, the present invention will be described in more detail with reference to examples.
The present invention is not limited to these examples.

Example 1 Asphalt having a penetration of 80 to 100 was heated and melted at 150 ° C. On the other hand, the surfactants shown in Table 1 and 0.15 parts by weight of calcium chloride were dissolved in warm water at 50 ° C., and then tannic acid was added and dissolved. 40 parts by weight of this 50 ° C. emulsion and 15
An emulsion was prepared by simultaneously passing 60 parts by weight of molten asphalt at 0 ° C. through a colloid mill. However, when an amine-based surfactant was used, hydrochloric acid was added to adjust the emulsion to pH 3.

For comparison, an emulsion without tannic acid was also prepared.

Aggregate mixing performance and adhesion performance of the obtained emulsion were measured and are shown in Table 1.

As is evident from Table 1, tannic acid not only acts as an emulsifying aid even when any surfactant is used, but also enhances the function of mixing the aggregates, and furthermore, is effective against any kind of aggregates. Also has the effect of significantly improving the adhesion.

Example 2 Asphalt having a penetration of 80 to 100 was heated and melted at 150 ° C. Separately, 0.5 parts by weight of tallow propylenediamine, 0.15 parts by weight of calcium chloride and 0.62 parts by weight of 35% hydrochloric acid were added to warm water at 50 ° C. and dissolved transparently. An emulsion was prepared by simultaneously passing 40 parts by weight of this 50 ° C. emulsion and 60 parts by weight of the above-mentioned molten asphalt at 150 ° C. through a colloid mill. A 50% by weight aqueous solution of tannic acid was added to this emulsion, followed by mixing to test the mixability of the aggregate.

 The results are shown in Table 2.

As is apparent from Table 2, it is possible to convert the emulsion into a slow-degrading emulsion by adding tannic acid to the conventional rapid-degrading emulsion. That is, the present invention has revealed for the first time that the decomposability of an emulsion can be freely adjusted according to the practical use by the amount of tannic acid added.

Example 3 Asphalt having a penetration of 80 to 100 was melted by heating to 150 ° C. Separately, 0.5 parts by weight of tallow propylenediamine, 0.93 parts by weight of 35% hydrochloric acid, and 0.15 parts by weight of calcium chloride were added to hot water at 50 ° C. and dissolved. 0.4 parts by weight of the water-soluble polymer shown in Table 3 was added to and dissolved therein. This 50 ° C emulsion 40
An emulsion was prepared by simultaneously passing a weight part and 60 parts by weight of the above-mentioned molten asphalt at 150 ° C. through a colloid mill, and an aggregate mixing property and an adhesion test were carried out. The results are shown in Table 3.

As is evident from Table 3, the known water-soluble polymer has insufficient aggregate mixing properties and has no effect of improving the adhesion. However, it can be seen that an emulsion having excellent mixability and adhesion can be obtained with the formulation of tannic acid and a tannin compound.

Claims (1)

(57) [Claims] 1. A bituminous emulsion comprising 40 to 80 parts by weight of bituminous material, 60 to 20 parts by weight of water, 0.01 to 10.0 parts by weight of a surfactant, and 0.01 to 5.0 parts by weight of tannic acid or a tannin compound. .