JPH07292259A - Additive for high-durability heated bitumen, high-durability asphalt pavement composition and its production - Google Patents

Abstract

PURPOSE:To obtain the subject additive which can heighten the adhesion of bitumen to an aggregate and, as a result of this, can allow the bitumen to exhibit very excellent effect of peeling prevention. CONSTITUTION:This additive comprises a polycarboxylic acid anhydride represented by the formula and having a number-average molecular weight of 500-20000. In the formula, R<1> to R<3> are each hydrogen or a 1-30 C linear or branched alkyl or alkenyl; 6<=(the total of the numbers of carbon atoms of R<1> to R<3>)<=30; and (n) is an integer corresponding to a number-average molecular weight of 500-20000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heated bituminous additive comprising a specific polycarboxylic acid anhydride, an asphalt pavement composition using the same, and a method for producing the same, and more particularly to a bituminous substance. As a result, the adhesion between the aggregate and the aggregate is strengthened, and as a result, an additive for heated bituminous material capable of exhibiting an extremely excellent peeling inhibitor effect on the bituminous material, an asphalt pavement composition using the additive, and The present invention relates to a manufacturing method.

[0002]

Bituminous substances such as asphalt, tar and pitch obtained from petroleum or coal are used for paving materials, roofing materials and waterproofing materials, and especially for paving materials. Is big. However, since the bituminous substance is non-polar, it does not sufficiently adhere to the aggregate and has a defect that the bituminous substance is separated from the aggregate due to the intervening action of water such as precipitation or groundwater.

Further, as the size and weight of vehicles increase, rutting and fluidization of asphalt pavement occur, impairing smooth traffic and running performance. As a countermeasure against this, a method of mixing thermoplastic resin or rubber into the bitumen has been devised.
However, a bituminous material mixed with a thermoplastic resin or rubber has a problem that the adhesiveness between the aggregate and the bituminous material is lower than that of the original bituminous material.

As described above, the technical problem of improving the adhesion between the bituminous material and the aggregate is an extremely important problem for improving the performance of asphalt pavement, but various methods have been devised to solve the problem. There is. For example, according to Japanese Examined Patent Publication No. 55-38995, higher aliphatic polyamines and their derivatives are used as a countermeasure for this, but conventionally devised higher aliphatic polyamines and their derivatives have improved initial adhesion improving performance. However, the durability of the effect of preventing peeling is said to be about one year.

Further, Japanese Patent Application Laid-Open No. 57-51745 proposes a method of adding a silane compound to improve the adhesion performance. However, it is harmful when it is added to a heated bituminous material or during the production of a heated mixture. It emits various odors and steam and leaves a problem in terms of safety and hygiene, and it is neither economical nor practical.

Furthermore, a composition prepared by adding and mixing a phosphoric acid compound such as phosphorus pentoxide, polyphosphoric acid and phosphorus pentasulfide to asphalt is used as an additive for asphalt modification.
Although disclosed and proposed in Japanese Patent No. 3691, these phosphoric acid compounds are inorganic substances and their dispersion state in an organic substance is not always good, and the adhesion performance of asphalt to an aggregate is insufficient. Furthermore, in recent years, there is a concern that the quality of asphalt and aggregate will deteriorate, but in the recycling method that uses waste pavement material, asphalt of reduced quality is used, so strong adhesion cannot be expected, and asphalt cannot be modified. Although more and more strongly desired, a means for solving all of the above-mentioned problems and various performances required by the market has not been developed yet.

JP-A-60-188462 describes that an acidic organic phosphoric acid compound has a peeling-preventing effect, but under the present circumstances where the level for asphalt pavement is increasing due to the current heavy transportation, The performance is insufficient to satisfy these requirements, and the development of an additive having further peeling prevention performance is desired.

[0008]

The inventors of the present invention have made diligent efforts to obtain a bituminous composition excellent in peeling prevention property, and as a result, a specific polycarboxylic acid anhydride has a particularly excellent peeling prevention effect. The inventors have found that they have the ability to express in the present invention and completed the present invention.

That is, the present invention has a number average molecular weight of 500 to 2
The present invention relates to a highly durable additive for hot bituminous substances, which is characterized by having a polycarboxylic acid anhydride content of 0,000 and represented by the following general formula (I).

[0010]

[Chemical 2]

[Wherein R ^{1 to} R ³ are hydrogen or 1 to 30 carbon atoms]
And a linear or branched alkyl or alkenyl group, and satisfying 6 ≦ (carbon number of R ¹ + carbon number of R ² + carbon number of R ³ ) ≦ 30, and n is a number average molecular weight of 500 to 20,000
Is an integer that satisfies The present invention also relates to an asphalt mixture 3 in which 0.05 to 5 parts by weight of the above additives are added to 100 parts by weight of heated asphalt.
~ 10 parts by weight, aggregate of crushed stone, sand and filler 97 ~ 90
The present invention relates to a highly durable asphalt pavement composition, characterized by comprising:

The present invention further relates to a method for producing the above-mentioned highly durable asphalt pavement composition, which comprises kneading an asphalt mixture prepared by adding the above-mentioned additives to heated asphalt in advance and an aggregate.

The additive of the present invention may be a single compound or a mixture of a plurality of compounds.

Conventionally devised higher aliphatic polyamines and their derivatives are adsorbed and oriented in polar positive and negative polar groups,
Improves wetting between bituminous material and aggregate. However, it is effective for initial adhesion, but has a problem for long-term adhesion. For example, when external stress such as temperature rise and dynamic load is applied in the presence of water for a long period of time, since the additive itself is a surfactant, it acts as a bituminous emulsifier and removes bitumen from the aggregate. There is a drawback that

The present invention has a composition in which molecules are arranged most densely at the interface between the bituminous material and the aggregate, and further, as shown in the following reaction formula, a chemical bond is formed at the interface by a dehydration reaction to strengthen the structure. Adhesion does not replace the bituminous material even if water enters the surface of the aggregate, and it does not destroy the adhesive interface between the aggregate and the bituminous material even if it receives an impact, and exhibits an excellent anti-stripping effect. it is conceivable that.

[0016]

[Chemical 3]

The polycarboxylic acid anhydride represented by the general formula (I) has a number average molecular weight of 500 to 500 obtained by a copolymerization reaction of an olefin having 8 to 32 carbon atoms with maleic anhydride.
It is a relatively low molecular weight copolymer of 20,000. Incidentally, the number average molecular weight means a polystyrene equivalent measured by high performance liquid chromatography (tetrahydrofuran solvent, measurement temperature 40 ° C.), preferably 500 to 20,000,
It is more preferably 500 to 10,000. Number average molecular weight is 5
If it is less than 00, the copolymerization system obtained by the copolymerization reaction of an olefin and maleic anhydride will contain a large amount of only an olefin compound or a maleic anhydride compound,
That is, the content of unreacted material increases, and the polycarboxylic acid anhydride represented by the general formula (I), which is a copolymerization reaction product of olefin and maleic anhydride, substantially decreases. Also, if the number average molecular weight exceeds 20,000, the viscosity becomes too high, and the physical properties of the asphalt are affected when added to the asphalt, which is not preferable.

Examples of olefins used are n-
Octene, iso-octene, n-decene, iso-decene, n-dodecene, iso-dodecene, n-butadecene,
An olefin having 8 to 32 carbon atoms such as iso-butadecene, n-hexadecene, iso-hexadecene, n-octadecene, iso-octadecene is used. Also, a mixture of these may be used. For practical use, olefins obtained by cracking petroleum paraffin or polymerization of ethylene, propylene, butylene, etc., butadiene oligomers, olefins obtained by dehydrogenation of petroleum paraffin, and the like are suitable.

In order to form an optimal adhesive interface that is dense in terms of molecular structure and sequence, R ^{1 to} R ³ in the polycarboxylic acid anhydride represented by the general formula (I) are hydrogen or 1 to 1 carbon atoms. 30 is a linear or branched alkyl group or alkenyl group,
Moreover, the total number of carbon atoms of R ^{1 to} R ³ is preferably 6 to 30.
If it is less than 6, the hydrophobicity of the surface of the aggregate is low, so that it is necessary to increase the amount used, and the economic merit is small. Also, if it exceeds 30, the reactivity with the aggregate surface will decrease,
The effect of preventing peeling is reduced. The preferred carbon number is 12 to 18, and the most preferred carbon number is 18.

The additive of the present invention is 0.05 to 5.0% by weight, preferably 0.1 to 3.0% by weight, based on the bituminous or modified bituminous substance.
Is. If less than 0.05% by weight, the effect decreases, and 5.0% by weight
If it exceeds, it is effective but not economical.

Further, the additive of the present invention can enhance the adhesive strength of the modified bituminous substance by using together at least one selected from rubbers, thermoplastic resins and thermosetting resins. .

As rubbers used in combination with the additive of the present invention, natural rubber, styrene / butadiene rubber, styrene / butadiene / styrene rubber, chloroprene rubber, acrylonitrile / butadiene rubber, styrene / isoprene rubber,
Examples thereof include synthetic rubbers such as styrene / isoprene / styrene rubber, methyl methacrylate / butadiene rubber, and butadiene rubber, but are not limited thereto.

As the thermoplastic resin used in combination with the additive of the present invention, ethylene, propylene, vinyl acetate, acrylic acid ester, methacrylic acid ester, styrene,
Examples thereof include, but are not limited to, vinylidene chloride and vinyl propionate homopolymers and copolymers obtained by combining these. Among these, especially ethylene / vinyl acetate copolymers and ethylene / vinyl acetate
Copolymers of ethyl acrylate are preferred.

Examples of the thermosetting resin used in combination with the additive of the present invention include, but are not limited to, epoxy resin and urethane resin.

It is said that when a large amount of rubbers, thermoplastic resins and thermosetting resins are used, the adhesive strength of the modified bituminous material tends to be rather lowered, and it is suitable for the additive of the present invention. The combined use remarkably enhances the adhesive strength and solves the problem.

The amount of the modifiers such as rubbers, thermoplastic resins and thermosetting resins added to the bituminous material is 80 to 99 parts by weight of the bituminous material and 20 to 1 parts by weight of the modifying material. The proportion of the modifying agent is preferably 15 to 2 parts by weight, and the bituminous and modifying agents are used in an amount of 100 parts by weight.

Further, in addition to rubbers, thermoplastic resins and thermosetting resins, the modified asphalt used in the present invention includes inorganic fillers and organic fillers such as calcium carbonate, slaked lime, Portland cement and activated carbon, petroleum resins and low molecular weight compounds. It is also possible to use a petroleum-based softening agent such as polyethylene, a vegetable oil-based softening agent such as oleic acid, various plasticizers and sulfur in combination with the additive of the present invention.

The crushed stone, sand, and filler used for the highly durable asphalt pavement composition of the present invention are provided for the present invention regardless of their materials as long as they are in accordance with the asphalt pavement procedure (edited by Japan Road Association). be able to. Crushed stone,
The mixing ratio of the aggregate consisting of sand and filler is 3 to 10 parts by weight of the asphalt mixture containing the additive of the present invention, and the aggregate 97.
~ 90 parts by weight is preferred.

The highly durable asphalt pavement composition of the present invention is prepared by adding the additive of the present invention to asphalt which has been heated in the range of 120 to 200 ° C. and kneading the thoroughly mixed asphalt mixture with crushed stone, sand and filler. It is characterized by being manufactured by In producing the highly durable asphalt pavement composition of the present invention, by adding the additive of the present invention to pre-heated asphalt, the additive of the present invention is uniformly dispersed in the asphalt, and a uniform high durability asphalt. A pavement composition is obtained.

As a method for mixing the additive of the present invention with the modified bituminous material, the modifier and the additive are simultaneously added to the bituminous material which is heated and melted at 100 to 250 ° C. under stirring, or it is modified beforehand. Either method of producing a bituminous substance and then adding an additive may be used.

The modified bituminous substances obtained by adding the above-mentioned modifiers to the bituminous substances appropriately selected in practical use have excellent temperature sensitivity and durability, and by adding the additive of the present invention, adhesion and peeling prevention can be achieved. A bituminous composition having improved properties and having various performances required by the market is obtained.

Therefore, it can be used for construction purposes other than road paving, such as factory floors, roofing materials, and underground protective materials for vehicles, for the purpose of waterproof coating.

[0033]

EXAMPLES The present invention will be specifically described below, but the present invention is not limited to these examples. In addition, "%" in the following examples is "% by weight". To confirm the effect of the present invention, a Riedel and Weber test and a water immersion Marshall test were performed.

Riedel and Weber Test (RIEDEL
AND WEBER TEST) is a method proposed by the British Road Research Institute and is as follows. Crushed stone 43 with a particle size of 0.15-0.075 mm 43
1 part by weight and 43 parts by weight of crushed stone with a particle size of 0.3 to 0.15 mm
Heat to 70 ° C. 14 parts by weight of asphalt or modified asphalt heated and melted at 150 ° C is added to this and mixed well, and the crushed stone is completely covered with asphalt or modified asphalt. 0.5 g of the coated asphalt mixture is placed in a beaker containing 25 ml of a sodium carbonate solution having a predetermined concentration shown in Table 1 and boiled for 1 minute. Record the first solution where crushed stones and asphalt have begun to completely peel off, and determine the number of adhesion points. Table 1 shows the relationship between sodium carbonate and the number of adhesion points.

[0035]

[Table 1]

The water immersion marshall test was in accordance with the test method KODAN 202 “Marshall Test Method for Asphalt Mixtures” of the Japan Highway Public Corporation. However, the water immersion time of the test piece was increased from 48 hours to 96 hours, and the test was performed under more severe conditions.
The test was in accordance with the Marshall Stability Test Method (ASTM D 1559-65, Asphalt Paver, Appendix 4.10). The type of the asphalt mixture used in this test is a dense particle size asphalt mixture (13 mm), and the composition design of the mixture is about the optimum amount of asphalt (5.5%) obtained from the Marshall stability test using asphalt with a penetration of 60 to 80. A modified asphalt mixture was prepared with the same amount of asphalt for each modified asphalt. The test asphalt pavement composition test specimen was heated and melted asphalt at 165 to 180 ° C, and the additive of the present invention was added according to the conditions to prepare an asphalt mixture,
It was prepared by kneading with crushed stone, sand and filler heated to 165 to 180 ° C. Mixing conditions are mixing temperature 1
The temperature was 65 to 180 ° C and the compaction temperature was 165 to 180 ° C. Ten test pieces (10 cm in diameter, approximately 6.3 cm thick cylindrical) were made,
Of these, 5 have undergone the standard Marshall test and the remaining 5 have
The sample was immersed in a constant temperature water bath at 60 ° C. for 96 hours, and after completion of the immersion, the Marshall stability of the specimen was determined. Residual stability by the water immersion Marshall test was calculated from the following formula.

[0037]

[Equation 1]

Example 1 Tables 2 and 3 show slate asphalt (penetration of 60 to 80).
The sample asphalt was prepared by mixing the various additives shown in. The results of the Riedel and Weber test and the water immersion Marshall test are shown in Tables 2 and 3.

[0039]

[Table 2]

[0040]

[Table 3]

Example 2 95% of slate asphalt (penetration 60-80) and 5% of the modifier shown in Table 4 were mixed, and 0.5% of various additives shown in Table 4 were mixed with the slate asphalt. The modified asphalt was prepared by the following. The results of the Riedel and Weber test and the water immersion Marshall test are shown in Table 4.

[0042]

[Table 4]

* 1 Styrene / butadiene / styrene block copolymer * 2 Styrene / isoprene / styrene block copolymer * 3 Ethylene / vinyl acetate copolymer * 4 Styrene / butadiene copolymer * 5 Styrene / butadiene copolymer Gel type

[0044]

[Effects of the Invention] From the examples, the bituminous materials prepared by using the highly durable additive for heating bituminous material of the present invention have improved adhesiveness between aggregate and asphalt, remarkably improved anti-peeling effect, and durability. It is clear that it is improving. This additive enables recent advances in new pavement technology such as drainage pavement, and improving the durability of asphalt pavement is expected to have great benefits not only in terms of total cost but also in terms of the environment, and its ripple effect. Is big.

Claims (4)

[Claims] 1. A highly durable additive for heated bituminous substances having a number average molecular weight of 500 to 20,000 and comprising a polycarboxylic acid anhydride represented by the following general formula (I). [Chemical 1] [Wherein R ^{1 to} R ³ are hydrogen or a linear or branched alkyl or alkenyl group having 1 to 30 carbon atoms, and 6
<(Carbon number of R ¹ + carbon number of R ² + carbon number of R ³ ) ≦ 30, and n is an integer satisfying a number average molecular weight of 500 to 20,000. ] 2. The highly durable additive for heated bituminous substances according to claim 1, which is used in combination with one or more selected from rubbers, thermoplastic resins and thermosetting resins. 3. The heating asphalt in 100 parts by weight of claim 1.
Or 3 to 10 parts by weight of an asphalt mixture containing 0.05 to 5 parts by weight of the additive described in 2 and 97 to 90 parts by weight of an aggregate composed of crushed stone, sand and a filler. Paving composition. 4. The method according to claim 1, wherein the asphalt is preheated.
The method for producing a highly durable asphalt pavement composition according to claim 3, wherein the asphalt mixture containing the additive as described above is kneaded with an aggregate.