JPS601260A - Modified asphalt having good adhesion - Google Patents

Abstract

PURPOSE:To provide the title asphalt which has good adhesion and is free from flowing, peeling and wearing in the winter, by adding a small quantity of a silande compd. to a modified asphalt. CONSTITUTION:0.1-5pts.wt. silane compd. such as methyltrimethoxysilane is added to 95-99.9pts.wt. modified asphalt obtd. by mixing 1-20pts.wt. thermoplastic resin and/or rubber (e.g. an ethylen/ethyl acrylate copolymer having an ethyl acrylate content of 5-50wt% and a melt index of 0.5-50) with 50- 95pts.wt. asphalt (e.g. paving asphalt obtd. by adding an appropriate quantity of a softener to straight asphalt). The mixing is conducted by heating at 100- 250 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified asphalt with a high adhesive strength, and more particularly to a modified asphalt with a high adhesive strength obtained by adding a small amount of a silane compound to the modified asphalt.

Asphalt pavement surfaces at heavy traffic crossings or intersections are deformed, causing so-called flow phenomena such as rutting and corrugation. This has become a serious problem in terms of traffic safety, such as water repellency to oncoming cars and pedestrians, steering wheel grip, reduced anti-slip effect, and deterioration of driving feel. One of the measures to prevent this flow phenomenon is [
Asphalt modification is progressing in recent years, adding com or thermoplastic resin to asphalt is considered to be one of the effective methods.

Although the addition of rubber or thermoplastic resin improves the mechanical properties of asphalt, that is, reduces the flow of asphalt, it is not very effective in improving surface properties such as adhesion to bone tissue.

During the summer, water penetrates the asphalt pavement and the asphalt is subject to repeated loads from vehicles, causing the asphalt to peel away from the aggregate due to the water, a so-called delamination phenomenon. The results of road surveys regarding peeling have revealed that asphalt pavements with greater peeling phenomena have more severe flow. Therefore, it is important to improve not only the mechanical properties but also the surface properties of modified asphalt. In addition, spiked tires cause wear on the asphalt pavement in the winter. This also causes the running parts of the car to wear out, resulting in a bright color similar to ruts. This abrasion is similar to abrasion, so the asmol part wears out quickly, leaving crushed stones protruding.

At the inlet of the intersection, this protruding crushed stone is dug up by spikes. When crushed stones are scattered, wear accelerates rapidly. It is believed that these disadvantages can be overcome by increasing the durability if the adhesion between the modified asphalt and crushed stone can be improved.

As a means of increasing such adhesion, there is a method of using a surfactant in combination, and examples of the surfactant include higher fatty acids and higher aliphatic polyamines.

and higher aliphatic polyamine derivatives are often used, but their effects are said to last for about one year. Furthermore, Japanese Patent Publication No. 51-44134 proposes adding an aminoalkylsilane compound to asphalt to increase adhesion. However, 1) the effects of the above compounds are insufficient for modified asphalt. This is considered to be due to the fact that the modified asphalt is not in a state in which the modifier is dissolved in asphalt, but in a dispersed system in which the asphalt component is a dispersed phase in the entire continuous phase of the modified phase components. In other words, according to the present inventors' findings [~ and Jiro], compounds that impart surface activity to the modifier component that is the continuous phase are not effective, and compounds that are effective for asphalt are not necessarily omitted from modified asphalt. It cannot be effective.

As described above, there is no means to effectively prevent the flow phenomenon, peeling phenomenon, and winter wear peculiar to asphalt, and there has long been a desire for a technology that can eliminate all of these drawbacks of asphalt at the same time. The inventors of the present invention have made extensive research efforts to satisfy this demand, and have found that this objective can be achieved by modifying asphalt with a specific polymer and adding a silane compound to the modified asphalt. They discovered this and completed the present invention.

That is, the present invention provides a modified asphalt with a high adhesive strength, which is composed of 95 to 99.9 parts by weight of a modified asphalt obtained by mixing a thermoplastic resin or (and) rubber with asphalt, and 0.1 to 5 parts by weight of a silane compound. It provides:

As the asphalt according to the present invention, installed asphalt made from petroleum refinery can be used. That is, straight asphalt, 7 microbron asphalt, or asphalt prepared by adding a suitable softening agent to bituminous material produced from solvent removal to make it suitable for paving asphalt J/S can be used.

Thermoplastic resins or rubbers used as modifiers include natural rubber, smu (styrene-butadiene copolymer), OR
Synthetic rubbers such as (chloroprene copolymer), ethylene, vinyl acetate, acrylic esters, and methacrylic esters.

A homopolymer of styrene or a copolymer of a combination thereof can be used.

In particular, ethylene-vinyl acetate copolymers with a vinyl acetate content of 5 to 30% by weight -@'A with a melt index of 1 to 40, and ethylene-ethyl acrylate copolymers with an ethyl acrylate content of 5 to 50% by weight. It is preferable that the weight layer has a toe index of 0.5 to 50. The amount of the modifier added to asphalt is preferably 1 to 20 parts by weight, more preferably 17 to 95 parts by weight of the asphalt.
The amount of the Shikke modifier is 2 to 15 parts by weight.

Silane compound and 1. These include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-glycidoxyprobyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethoxysilane, r- Chloropropyl trimethoxy 7, γ-mercaptopropyl trimethoxy 7
, r-7 minobrovir trietquinran.

Methyltrimethoxysilane and dimethyldimethoxysilane can be used. Among these, those that do not contain nitrogen atoms in their molecules are preferred, especially methyltrimethoxysilane,
Preferred are γ-glycidoxypropyltrimethoxysilane, T-methacroxypropyltrimethoxysilane, and r-mercaptopropyltrimethoxysilane. The amount used can range from 0.1 to 5 weight percent based on the modified asphalt. If it is less than 0.1% by weight, the effect will be small, and if it exceeds 5% by weight, the effect will be saturated. The method of mixing the silane compound into the modified asphalt is to mix the modified asphalt with a
There is a method of heating the solution #lII/to 250° C. and adding the silane compound with stirring. Alternatively, the silane compound may be added to the mixture of aggregate heated to 140 to 200° C. and heat-modified asphalt before mixing.

RIBDEL & WEBERTEST is one of the laboratory tests conducted by the British Road Research Institute that corresponds to actual road tests.

This test method is simple, and the test results relatively correspond to the results of actual road tests, so the inventor used this method to confirm the effects of the present invention. That is, Dan I
EDBTJ & WEBERTENT is the following method. 43 parts by weight of aggregate with a particle size of 0.15-0.074 mm and 45 parts by weight of aggregate with a particle size of 0.5-0.15 mm are mixed and heated to 170°C. To this, 14 piles of modified asphalt heated and melted at 150°C (10 piles of the modifier added to the asphalt) are added and mixed well, so that the aggregate is completely covered with the modified asphalt. This coated aggregate 0.5
Add 25 mg of a sodium carbonate solution with a prescribed concentration shown in the table below (i) into a beaker and boil for 1 minute. Determine the number of adhesion points by recording the first solution where even a small amount of aggregate and asphalt begins to separate completely. The relationship between the concentration of soda carbonate and the number of adhesion points is as follows.

If the sample does not peel off at 1 molar concentration of soda carbonate, the number of adhesion points is 10.

The relationship between the number of adhesion points and the peelability in the actual road test is as shown in FIG. 1, and it can be understood from FIG. 1 that the number of adhesion points and the peeling prevention property are in a proportional relationship.

In addition, A, B, O, and D in the figure represent the types of rocks, and their contents are as follows.

Gen71 Rock A...5pi1.1tic (Spiritek) basalt〃 B...Cao P 1st - Coarse grained basalt〃 C... Solo containing analcite - R4 withdrawal - Coarse grained basalt Basalt J) ... Quartz - coarse-grained basalt granite ^ ... Soda granite〃 B ... Granosainite sand Rock A ... Porphyry breccia〃 B ... Tuff fragment Rock A ... Chrysanthemum porphyry A... Biotite porphyry rock B... Pyroxene-granite porphyry Rock C... Quartz - shale-edge porphyry 1 stone Gravel A... Stone gravel limestone A... Limestone ore Slag A... - From Molten Furnace Mine Float No. 11vI, it can be seen that 8 or more adhesion points are required to prevent peeling on actual roads.

Next, examples will be shown.

Various silane compounds shown in Table 1 were added to the modified asphalt of the example (penetration 60/80, addition amount of modification profit 10%) to produce modified asphalt with high adhesion 17. The above-mentioned RIFtDFtL was prepared using river sand prepared by Ki as the aggregate.
& WEBERTFi8T was performed to evaluate the adhesion. The results are shown in Table-1. Even if a modifier of ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, or styrene-butadiene rubber is added to asphalt, the number of adhesion points is 4, which is less than the number of adhesion points of 8, which does not cause peeling. It can be seen that when 0.5 to 5 heavy weight machines are added, the number of adhesion points becomes 8 or more, indicating that no peeling occurs.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the number of asphalt adhesion points and the peelability in an actual road test. Applicant's agent Wa Furutani

Claims (1)

[Scope of Claims] 1. An additive characterized by comprising 95 to 99.9 parts by weight of an improved asphalt obtained by mixing a thermoplastic resin or (and) rubber with asphalt and 0.1 to 5 parts by weight of a silane compound. Modified asphalt with great adhesion. 2. Modified asphalt according to claim 1, wherein the modified asphalt is obtained by adding thermoplastic resin or (and) rubber to 50 to 95 heavy machine parts of asphalt in the form of 1 to 20 double leaf parts. 3. The modified asphalt according to claim 1 or 2, wherein the thermoplastic resin has a melt index of 0.5 to 50.