JP2014031649A - Binder for pavement and mixture for pavement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder for pavement from which a mixture for pavement having a higher intensity than that of conventional petroleum asphalt for pavement and more excellent workability than that of cement concrete can be formed.SOLUTION: An inventive binder for pavement consists of polyamide resin only, or a binder mixture of polyamide resin and asphalt. In the case of the binder mixture, a mixing ratio of the polyamide resin is equal to or more than 90 mass% on the basis of the total amount of the polyamide resin and the asphalt, the softening point of the polyamide resin is equal to or more than 70°C and equal to or less than 100°C, and a melt viscosity of the polyamide resin at 180°C is equal to or less than 180 mPa*s.

Description

  The present invention relates to a pavement binder used for a pavement mixture for forming a pavement, and a pavement mixture formed using the pavement binder.

Since the pavement installed outdoors is heated by sunlight, the pavement surface temperature rises to about 60 ° C. at high temperatures in summer.
In general, paving petroleum asphalt (also referred to as straight asphalt) is used as a binder in a paving mixture for forming paving. Since the softening point of paving petroleum asphalt is about 50 ° C., it becomes softer in summer. For this reason, on routes using petroleum asphalt for paving, the mixture for paving may flow due to traffic load, and so-called rutting may occur.
Therefore, for the paving mixture that forms road pavements with heavy traffic, polymer modified asphalt modified by mixing high-molecular materials such as SBS (styrene / butadiene / block copolymer) with petroleum asphalt for paving. Is used as a binder. Since the strength of pavement using polymer-modified asphalt is higher than the strength of pavement using conventional petroleum asphalt for paving, there is an advantage that it is difficult to soften even at high temperatures. However, even with pavement using polymer-modified asphalt, there is a concern that fluidization of the mixture for pavement will occur if temperature conditions and traffic load conditions are assumed to be more severe.

As a paving material, cement concrete is used in addition to paving petroleum asphalt. Pavement using cement concrete has high strength in a wide temperature range from low temperature in winter to high temperature in summer, compared to pavement using petroleum asphalt for pavement.
However, pavement using cement concrete is inferior in flexibility to pavement using petroleum asphalt for pavement, and therefore has a drawback that cracking due to temperature change is likely to occur. For this reason, in the pavement using cement concrete, it was necessary to construct joints for preventing cracks at intervals of 5 to 10 m.
Also, pavement using cement concrete is constructed using a dedicated concrete finisher. However, the process of flattening the pavement surface with a concrete finisher is more complicated in construction work than the flattening process with an asphalt finisher. Cement concrete requires a curing period of about one week before it hardens. Thus, pavement using cement concrete is inferior in terms of construction workability and construction period compared to pavement using petroleum asphalt for pavement.

On the other hand, the present inventors contain at least one condensation polymerization resin selected from the group consisting of polyester resin, polyester polyamide resin and polyamide resin, and melt the condensation polymerization resin at 180 ° C. A colored pavement binder composition having a viscosity of 20000 mPa · s or less and a softening point of 80 to 180 ° C. has been proposed (see Patent Document 1).
Also, an asphalt mixture containing aggregate, polyamide resin and asphalt, wherein the polyamide resin has a softening point of 60 ° C. to 150 ° C., preferably the polyamide resin has a melt viscosity at 180 ° C. of 2000 mPa · s or less. Has been proposed (see Patent Document 2).

JP 2003-13403 A JP 2010-236435 A

However, even with the above-mentioned pavement mixture, it is possible to perform construction with the same machine organization and construction posture as before while improving resistance to severer temperature conditions and traffic load conditions and having excellent resistance. In terms of convenience above, there was still room for development.
Therefore, an object of the present invention is to provide a pavement mixture that has higher strength after completion of a paved road surface than conventional petroleum asphalt for paving and has better workability than conventional cement concrete.

As a result of intensive studies, the present inventors have found that the above problems can be solved by using a specific polyamide resin as a binder for a paving mixture, and have completed the present invention. That is, the gist of the present invention is as follows.
<1> A pavement binder used for a pavement mixture for forming a pavement, which is composed of a polyamide resin alone or a binder mixture of a polyamide resin and asphalt. In the case of the binder mixture, the blending ratio of the polyamide resin is 90 mass% or more based on the total amount of the polyamide resin and asphalt, the softening point of the polyamide resin is 70 ° C. or more and 100 ° C. or less, and the melt viscosity at 180 ° C. of the polyamide resin is 180 mPa · s or less. Paving binder,
<2> The paving binder according to <1>, wherein the polyamide resin includes a carboxylic acid component containing a monovalent carboxylic acid and a polymerized fatty acid, and an amine component containing a polyamine.
<3> The binder for paving according to the above <2>, wherein the monovalent carboxylic acid of the carboxylic acid component is 10 to 50 mol equivalent% based on the total amount of the carboxylic acid component.
<4> The pavement binder according to <2>, wherein the amine component is an amine component containing two or more aliphatic diamines,
<5> A paving mixture comprising the paving binder according to any one of the above items <1> to <4> and an aggregate.

  According to the present invention, a pavement binder capable of forming a pavement mixture having higher strength than pavement using conventional petroleum asphalt for pavement and better workability than pavement using cement concrete, and the pavement. It is possible to provide a paving mixture that is formed using a binder.

The present invention is described in detail below.
[Pavement binder]
The pavement binder according to an embodiment of the present invention is a pavement binder used for a pavement mixture for forming pavement, and is composed of a polyamide resin alone or a binder mixture of a polyamide resin and asphalt, and in the case of the binder mixture The blending ratio of the polyamide resin is 90% by mass or more based on the total amount of the polyamide resin and asphalt, the softening point of the polyamide resin is 70 ° C. or more and 100 ° C. or less, and the melt viscosity of the polyamide resin at 180 ° C. Is 180 mPa · s or less.

[Polyamide resin]
<Properties of polyamide resin>
The polyamide resin which can be used for the pavement binder shown as embodiment of this invention is demonstrated. The softening point of the polyamide resin is 70 ° C. or higher and 100 ° C. or lower, preferably 75 ° C. or higher and 90 ° C. or lower, more preferably 80 ° C. or higher and 85 ° C. or lower.
Since the pavement surface temperature in summer is about 60 ° C, the softening point of the polyamide resin is less than 70 ° C, and the rubbing of the pavement formed by the mixture for pavement containing polyamide resin, aggregate, etc. is sufficiently suppressed. Can not. On the other hand, when the softening point of the polyamide resin exceeds 100 ° C., the viscosity of the paving mixture is increased, and the road roller cannot be sufficiently compacted, and a predetermined density cannot be obtained after construction. For this reason, the durability of the pavement may be insufficient.
The polyamide resin has a melt viscosity at 180 ° C. of 30 to 180 mPa · s, preferably 50 to 150 mPa · s. By doing so, it is possible to obtain good workability while ensuring mixing with aggregates and the like. When the melt viscosity exceeds 180 mPa · s, it becomes difficult to form a uniform paving mixture together with aggregates and the like. Moreover, since workability falls, it is not preferable. In consideration of the thermal deterioration of the polyamide resin, it is not desirable to heat the resin at a temperature exceeding 180 ° C.

<Structure of polyamide resin>
Any polyamide resin having any chemical structure can be used as long as it has the properties described above as long as the polymer compound has an amide bond (—CONH—). The polyamide resin may be, for example, nylon mainly composed of an aliphatic skeleton or aramid mainly having an aromatic skeleton. Furthermore, you may have frame | skeleton structures other than these both. On the other hand, the structure suitably used includes a polyamide composed of an aliphatic diamine and a dicarboxylic acid.

The polyamide resin is usually obtained by a ring-opening polymerization reaction of a cyclic lactam, a self-condensation reaction of an amino acid or a derivative thereof, a condensation polymerization reaction of a carboxylic acid and an amine compound, or the like. A polyamide resin obtained by a condensation polymerization reaction between a carboxylic acid and an amine compound can be obtained, for example, by subjecting a carboxylic acid and an amine compound to a condensation (condensation polymerization) reaction.
Examples of the carboxylic acid that is one raw material of the condensation polymerization reaction include adipic acid, sebacic acid, dodecanedioic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, and alkenyl succinic acid (preferably, the alkenyl group has carbon atoms. 4 to 20 alkenyl succinic acid), polymerized fatty acid (for example, dimer acid obtained by reacting unsaturated fatty acid derived from vegetable oil), divalent carboxylic acid such as cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, and 2 And trivalent carboxylic acids such as 4-benzenetricarboxylic acid.

Examples of the amine compound that is the other raw material for the polycondensation reaction include polyamines, aminocarboxylic acids, and amino alcohols. Examples of polyamines include aliphatic diamines such as ethylenediamine, hexamethylenediamine, and propylenediamine, aliphatic triamines such as diethylenetriamine, aromatic diamines such as xylylenediamine and diphenylmethanediamine, and alicyclic diamines such as piperazine and isophoronediamine. . Examples of the aminocarboxylic acid include methyl glycine, trimethyl glycine, 6-aminocaproic acid δ-aminocaprylic acid, and ε-caprolactam. Examples of amino alcohols include ethanolamine and propanolamine.
Each compound used as these raw materials can be used alone or in combination of two or more.

Furthermore, the polyamide resin used in this embodiment can use a carboxylic acid component containing a monovalent carboxylic acid and a polymerized fatty acid in the carboxylic acid as the carboxylic acid component.
Further, as the amine compound, an amine component containing a polyamine, particularly preferably, an amine component containing two or more aliphatic diamines as the amine compound, most preferably an amine component selected from two or more aliphatic diamines is used. Can do.
If the polyamide resin is obtained by condensing these carboxylic acid component and amine component, those satisfying characteristics such as softening point and melt viscosity required for the polyamide resin used in the present invention can be easily found.
According to the pavement mixture containing this polyamide resin, aggregate, etc., it is possible to further prevent pavement rutting and torsional breakage and improve oil resistance.
Furthermore, a polyamide resin obtained using an amine component containing two or more aliphatic dipolyamines as an amine compound, most preferably an amine component selected from two or more aliphatic diamines, is particularly excellent in the above-described performance. For example, by using a monovalent carboxylic acid and a polymerized fatty acid as the carboxylic acid component, it becomes easy to adjust the melt viscosity of the obtained polyamide resin.

The blending ratio of the monovalent carboxylic acid and the polymerized fatty acid constituting the carboxylic acid component is preferably 10 to 50 mol equivalent% for the former and 50 to 90 mol equivalent% for the latter, based on the total amount of the carboxylic acid component. Is more preferably 10 to 30 mol equivalent% and the latter is 90 to 70 mol equivalent%.
In addition to the aliphatic monovalent carboxylic acid and polymerized fatty acid, other carboxylic acid may be added to the carboxylic acid component as long as the physical properties are not impaired.

  As the monovalent carboxylic acid, an aliphatic monovalent carboxylic acid having 1 to 22 carbon atoms is preferable, and an aliphatic monovalent carboxylic acid having 12 to 20 carbon atoms is more preferable. The aliphatic monovalent carboxylic acid is more preferably an aliphatic monovalent carboxylic acid having 12 to 20 carbon atoms, or a mixture of two or more kinds selected therefrom. By using such an aliphatic monovalent carboxylic acid or a mixture thereof as the aliphatic monovalent carboxylic acid, the crystallinity of the polyamide resin is lowered, and the softening point of the polyamide resin is adjusted to 100 ° C. or less. Becomes easier.

  As said C12-C22 aliphatic monovalent carboxylic acid, a saturated or unsaturated thing can be used. Examples of the saturated aliphatic monovalent carboxylic acid include lauric acid, palmitic acid, stearic acid, alginic acid, and behenic acid. Further, as the unsaturated aliphatic monovalent carboxylic acid, for example, oleic acid, linoleic acid, linolenic acid, eicosenoic acid, erucic acid, mixed fatty acids obtained from natural fats and oils (tall oil fatty acid, rice nuka fatty acid, soybean oil fatty acid, Beef tallow fatty acid and the like), and these may be used alone or in combination of two or more. The polymerized fatty acid is a polymer obtained by polymerizing a monobasic fatty acid having an unsaturated bond or an esterified product thereof.

  As the monobasic fatty acid having an unsaturated bond, an unsaturated fatty acid having 8 to 24 total carbon atoms and having 1 to 3 unsaturated bonds is usually used. Examples include fatty acids such as oleic acid, linoleic acid, linolenic acid, and natural dry or semi-dry oil fatty acids. Examples of the ester of a monobasic fatty acid having an unsaturated bond include esters of the monobasic fatty acid having an unsaturated bond and an aliphatic alcohol, preferably an aliphatic alcohol having 1 to 3 carbon atoms. The polymerized fatty acid, which is a polymer of a monobasic fatty acid having an unsaturated bond or an esterified product thereof, preferably has a dimer as a main component. For example, as a polymer of an unsaturated fatty acid having 18 carbon atoms, the composition of the monobasic acid (monomer) having 18 carbon atoms is 0 to 10% by mass, and the dibasic acid having 36 carbon atoms (dimer) is 60 to 60%. A 99 mass%, 54 or more tribasic acid acid (trimer or more) of 30 mass% or less is commercially available.

  Next, as a polyamine contained in the amine component used together with the carboxylic acid component, an aliphatic triamine and an aromatic diamine can be used in addition to the aliphatic diamine as long as the physical properties are not impaired. In this case, the blending ratio of each of the polyamines in the amine component is 90 to 100 molar equivalents of the aliphatic diamine and 0 to 20 molar equivalents of the aliphatic triamine and / or aromatic diamine based on the total amount of the amine component. More preferably, the aliphatic diamine is 95 to 100 mole equivalent%, the aliphatic triamine and / or the aromatic diamine is more preferably 0 to 5 mole equivalent%, and the aliphatic diamine is particularly preferably 100 mole equivalent%. .

  The aliphatic diamine is preferably an aliphatic diamine having 2 to 6 carbon atoms, and examples thereof include ethylene diamine, propylene diamine, butylene diamine, and hexamethylene diamine. In the present invention, it is particularly preferable to use two or more kinds of the above-mentioned amines together, whereby the orientation of the amide group between the polyamide molecules can be adjusted, and the adjustment of the softening point and the 180 ° C. melt viscosity can be easily achieved. . Among them, a mixture containing ethylenediamine and hexamethylenediamine is preferable.

  The polyamide resin can be produced by subjecting the raw material compounds to a condensation reaction under known reaction conditions. For example, a molar equivalent ratio (carboxylic group / amino group) of 1.0 / 1.2 to 1.2 / 1.0 of a carboxylic acid component such as monovalent carboxylic acid or polycarboxylic acid and an amine component such as polyamine compound What is necessary is just to carry out a condensation reaction at 180-250 degreeC, for example, mixing and heating.

[Binder mixture]
<Polyamide resin>
As the polyamide resin constituting the binder mixture, the above-described polyamide resin can be applied.

<Asphalt>
Asphalt usable in the binder for paving according to the embodiment of the present invention includes straight asphalt which is petroleum asphalt for paving, styrene / butadiene block copolymer (SBS), styrene / isoprene / block copolymer ( SIS), polymer modified asphalt modified with a polymer material such as a thermoplastic elastomer such as ethylene / vinyl acetate copolymer (EVA), and the like. Asphalt can be used as long as it conforms to JIS K2207 (1996) and the Japan Modified Asphalt Association Standard. Moreover, the binder mixture contained in the existing asphalt pavement and the asphalt regenerated from the aggregate can also be used.

<Combination ratio>
In the polyamide resin and asphalt constituting the binder mixture, the blending ratio of the polyamide resin is 90% by mass or more, preferably 95% by mass or more based on the total amount of the polyamide resin and asphalt. When the blending ratio of the polyamide resin is less than 90% by mass, the elastic modulus and bending strength required at a high temperature (60 ° C.) cannot be satisfied. In addition, when using the reproduction | regeneration asphalt mentioned above for a binder mixture, it is preferable to set it as 10 mass% or less on the total amount reference | standard of a polyamide resin and a reproduction | regeneration asphalt.

[Pavement mixture]
The mixture for paving according to the embodiment of the present invention includes an aggregate and a binder for paving. The paving binder is composed of a polyamide resin alone or a binder mixture of polyamide resin and asphalt. In the case of the binder mixture, the blending ratio of the polyamide resin is 90% by mass or more based on the total amount of the polyamide resin and asphalt. The pavement binder described in detail above is used in which the softening point of the polyamide resin is 70 ° C. or more and 100 ° C. or less, and the melt viscosity of the polyamide resin at 180 ° C. is 180 mPa · s or less.

<Aggregate>
Examples of the aggregate that can be used in the mixture for paving according to the embodiment of the present invention include crushed stone, sand, screenings, stone powder, and recycled aggregate described in the paving design and construction guidelines (Japan Road Association). Aggregates other than this can also be used. A fiber reinforcing material, a pavement filler, and the like can be appropriately added to the aggregate.

<Mixing ratio of aggregate and paving binder>
The aggregate that can be used in the paving mixture is mixed with an amount of paving binder suitable for the aggregate particle size. As for the amount of the binder for paving, it is desirable to determine the optimum amount of asphalt determined based on the “blending design of asphalt mixture” described in the Guide for Pavement Design and Construction (Japan Road Association) as the optimum amount of binder. However, when the binder mixture is used as a pavement binder, 90% by mass or more of the optimum binder amount is defined as the polyamide resin defined in the present invention.

The pavement mixture according to the embodiment of the present invention can be applied to the floor at the construction site with the same machine organization and construction posture as conventional paving oil asphalt. In addition, the paving mixture according to the present embodiment is cured by a decrease in temperature, similarly to the conventional binder mixture mainly composed of paving petroleum asphalt.
The mixture for paving according to the present embodiment has a high elastic modulus and bending strength at high temperature (60 ° C.) after curing, compared with paving using conventional petroleum asphalt for paving and paving using polymer-modified asphalt. . Moreover, all the performance required for pavement can be satisfied at a high level. The bending strength at 60 ° C. of the mixture for paving according to the present embodiment exceeds the concrete for paving (design bending strength 4.5 MPa).

Moreover, the polyamide resin which comprises a binder with the mixture for paving which concerns on embodiment of this invention does not melt | dissolve in petroleum oil. That is, it is excellent in oil resistance as compared with conventional pavement using petroleum asphalt for pavement. Therefore, the pavement using the pavement mixture according to the present embodiment is not easily eroded.
The pavement mixture according to this embodiment is also suitably used for pavement constructed on a bridge slab over a road from the viewpoint of high strength and excellent workability. Strength can be given to the structure of the bridge. In addition, since construction can be completed in a short period of time, it is advantageous for repair work for bridges that cannot easily set detours like roads.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
[Evaluation method]
The physical properties and workability of the pavement mixtures of Examples and Comparative Examples were evaluated according to the following methods.
(1) Wheel Tracking Test The wheel tracking test was conducted in accordance with the “wheel tracking test” described in “Handbook of Pavement Survey and Test Methods” published by the Japan Road Association. The measurement limit value (upper limit) of the used testing machine is 63000 times / mm.
(2) Bending test The bending test was conducted in accordance with the “bending test” described in “Handbook of Pavement Survey and Testing Methods” published by the Japan Road Association. The test temperature was set to -10 ° C and 60 ° C.
(3) Torsion resistance test The test was conducted in accordance with the “torsion resistance test” described in “Handbook of Pavement Survey and Test Methods” published by the Japan Road Association.
(4) Bending fatigue test The bending fatigue test was carried out in accordance with "Bending fatigue test of asphalt mixture" described in "Handbook of pavement survey and test method" published by Japan Road Association. The test temperature was 20 ° C and 60 ° C. The average value of the elastic modulus of 500 to 1000 times of loading was taken.
(5) Test after kerosene immersion (Evaluation of oil resistance)
After immersing the sample (mixture) in normal temperature kerosene for 24 hours, a wheel tracking test was conducted as in (1).
(6) Workability during construction Workability was evaluated by scoop workability.
About the sample (asphalt mixture) heated at 150 degreeC, the workability | operativity at the time of pavement construction using a scoop was determined by the following references | standards.
A: Workability is good compared to a general dense particle size asphalt mixture B: Work is slightly difficult compared to a general dense particle size asphalt mixture, but work is possible C: General dense particle size Compared to asphalt mixture, work is difficult, but work is possible. D: Compared to general dense particle size asphalt mixture, work is considerably difficult, and there are some problems in construction. E: General dense particle size Workability is poor and workability is poor compared to asphalt mixture

[Production and properties of polyamide resin]
<Polyamide resin A>
The polyamide resin A is obtained by condensing a carboxylic acid component containing propionic acid, tall oil fatty acid and polymerized fatty acid (“Haridimer 250” manufactured by Harima Chemicals) with an amine component composed of ethylenediamine and m-xylylenediamine. It is a thing.
Polyamide resin A (the production methods of polyamide resins B to D described below are also the same) were synthesized in accordance with the production method described in Patent Literature 2 [0032].
That is, a mixture of a carboxylic acid component containing propionic acid, tall oil fatty acid, and polymerized fatty acid as raw materials and an amine component is added to a four-necked round bottom flask equipped with a thermometer, a stirring system, a dehydrating tube, and a nitrogen blowing tube. The mixture was stirred, and a slight amount of nitrogen was passed in order to prevent coloring, followed by reaction at 210 ° C. for 3 hours. Furthermore, after making it react under reduced pressure (13.3 kPa) for 2 hours, it cooled and grind | pulverized and the polyamide resin A was obtained.
As for each carboxylic acid component, 0.05 mol equivalent of propionic acid per mol equivalent of the carboxylic acid component (2.5 mol equivalent% for the whole raw material charged, the same applies hereinafter), tall oil fatty acid 0.20 mole equivalent (10 mole equivalent%), polymerized fatty acid is 0.75 mole equivalent (37.5 mole equivalent%), and for the amine component, ethylenediamine is 0.90 mole equivalent per mole equivalent of amine component ( 45 mole equivalent%) and m-xylylenediamine is 0.10 mole equivalent (5 mole equivalent%).
The molar equivalents of tall oil fatty acid and polymerized fatty acid were similarly calculated from the measured value of the acid value based on the JIS standard method (K2501). The ratio of the carboxylic acid component to the amine component is 1.0 / 1.0 in terms of molar equivalent ratio (carboxylic acid component / amine component).
The physical properties of the polyamide resin A were a softening point of 110 ° C. and a 180 ° C. melt viscosity of 198 mPa · s.

<Polyamide resin B>
The polyamide resin B is obtained by condensing a carboxylic acid component containing propionic acid, tall oil fatty acid and polymerized fatty acid (“Haridimer 250” manufactured by Harima Chemical Co., Ltd.) with an amine component composed of ethylenediamine and m-xylylenediamine. It is a thing.
About each content rate and a carboxylic acid component, 0.1875 mol equivalent (9.375 mol equivalent%) of propionic acid per mol equivalent of a carboxylic acid component, 0.0625 mol equivalent (3.125 mol equivalent%) of tall oil fatty acid ), The polymerized fatty acid is 0.75 molar equivalent (37.5 molar equivalent%), and the amine component is 0.86 molar equivalent (43 molar equivalent%) of ethylenediamine per molar equivalent of the amine component. The amine is 0.14 molar equivalent (7 molar equivalent%). The ratio of the carboxylic acid component to the amine component is 1.0 / 1.0 in terms of molar equivalent ratio (carboxylic acid component / amine component).
The physical properties of the polyamide resin B were a softening point of 125 ° C. and a 180 ° C. melt viscosity of 233 mPa · s.

<Polyamide resin C>
The polyamide resin C is obtained by condensing a carboxylic acid component containing a tall oil fatty acid and a polymerized fatty acid (“Haridimer 250” manufactured by Harima Chemical Co., Ltd.) and an amine component composed of ethylenediamine and hexamethylenediamine.
Each content ratio is 0.30 mole equivalent (15 mole equivalent%) of tall oil fatty acid and 0.70 mole equivalent (35 mole equivalent%) of polymerized fatty acid per mole equivalent of the carboxylic acid component. With respect to the amine component, ethylenediamine is 0.50 molar equivalent (25 molar equivalent%) and hexamethylenediamine is 0.50 molar equivalent (25 molar equivalent%) per molar equivalent of the amine component. The ratio of the carboxylic acid component to the amine component is 1.0 / 1.0 in terms of molar equivalent ratio (carboxylic acid component / amine component).
The physical properties of the polyamide resin C were a softening point of 82 ° C. and a 180 ° C. melt viscosity of 70 mPa · s.

<Polyamide resin D>
The polyamide resin D is obtained by condensing a carboxylic acid component containing a tall oil fatty acid and a polymerized fatty acid (“Haridimer 250” manufactured by Harima Chemicals Co., Ltd.) and an amine component composed of ethylenediamine and hexamethylenediamine.
Each content ratio is 0.30 mole equivalent (15 mole equivalent%) of tall oil fatty acid and 0.70 mole equivalent (35 mole equivalent%) of polymerized fatty acid per mole equivalent of the carboxylic acid component. With respect to the amine component, ethylenediamine is 0.70 molar equivalent (35 molar equivalent%) and hexamethylenediamine is 0.30 molar equivalent (15 molar equivalent%) per molar equivalent of the amine component. The ratio of the carboxylic acid component to the amine component is 1.0 / 1.0 in terms of molar equivalent ratio (carboxylic acid component / amine component).
The physical properties of the polyamide resin D were a softening point of 98 ° C. and a 180 ° C. melt viscosity of 78 mPa · s.

[Examples and Comparative Examples]
Using the polyamide resins A and B, a pavement mixture of a comparative example was prepared. Moreover, the mixture for paving of the Example was produced using the polyamide resin C and D.
<Example 1>
When preparing a dense particle size mixture (pavement mixture) including coarse aggregate having a maximum particle size of 13 mm and straight asphalt having an optimum amount of asphalt (referred to as staus), 90% by mass of the straight asphalt is added to the polyamide resin C. A substituted binder mixture was used. This binder mixture and coarse aggregate were mixed at 150 ° C. with a mixer. The paving mixture obtained by mixing was compacted at 110 ° C. to obtain the asphalt mixture of Example 1.
Note that the compaction temperature is the pavement construction manual (2006 edition) p. The lower limit of the initial rolling pressure of the asphalt mixture described in 112 was determined with reference to FIG.

<Example 2>
A paving mixture was prepared under the same conditions as in Example 1 except that a binder mixture in which 95% by mass of the straight asphalt was replaced with polyamide resin C was used.
<Example 3>
10% by weight of the straight asphalt was replaced with the binder mixture contained in the existing asphalt pavement and the asphalt extracted from the aggregate (referred to as old asphalt), and the remaining 90% by weight of the binder mixture was replaced with polyamide resin C. used. The amount of existing asphalt-derived aggregate (referred to as recycled aggregate) was 10% by mass based on the total aggregate, and the amount of new aggregate was 90% by mass. Except for the above, a paving mixture was prepared under the same conditions as in Example 1.

<Example 4>
A paving mixture was produced under the same conditions as in Example 1 except that a binder in which the entire amount (100% by mass) of straight asphalt was replaced with polyamide resin C was used.
<Example 5>
A paving mixture was prepared under the same conditions as in Example 1 except that a binder mixture in which 90% by mass of straight asphalt was replaced with polyamide resin D was used.
<Example 6>
A paving mixture was produced under the same conditions as in Example 1 except that a binder mixture in which 95% by mass of straight asphalt was replaced with polyamide resin D was used.
<Example 7>
Pavement under the same conditions as in Example 1 except that a binder mixture in which 90% by mass of straight asphalt is replaced with polyamide resin D is used, using an aggregate that uses the same recycled aggregate as in Example 3. A mixture was prepared.
<Example 8>
A paving mixture was prepared under the same conditions as in Example 1 except that a binder in which the entire amount (100% by mass) of straight asphalt was replaced with polyamide resin D was used.

<Comparative Example 1>
Straight asphalt was used as a binder mixture without replacing it with polyamide resin. A paving mixture was prepared under the same conditions as in Example 1.
<Comparative example 2>
A paving mixture was produced under the same conditions as in Example 1 except that a binder mixture in which 90% by mass of the straight asphalt was replaced with polyamide resin A was used.
<Comparative Example 3>
A paving mixture was produced under the same conditions as in Example 1 except that a binder mixture in which 95% by mass of the straight asphalt was replaced with polyamide resin A was used.

<Comparative Example 4>
Pavement under the same conditions as in Example 1 except that a binder mixture in which 90% by mass of the straight asphalt was replaced with polyamide resin A was used, using an aggregate using the same recycled aggregate as in Example 3. A mixture was prepared.
<Comparative Example 5>
A paving mixture was prepared under the same conditions as in Example 1 except that a binder in which the entire amount (100% by mass) of straight asphalt was replaced with polyamide resin A was used.
<Comparative Example 6>
A paving mixture was prepared under the same conditions as in Example 1 except that a binder mixture in which 90% by mass of straight asphalt was replaced with polyamide resin B was used.
<Comparative Example 7>
A paving mixture was prepared under the same conditions as in Example 1 except that a binder mixture in which 95% by mass of straight asphalt was replaced with polyamide resin B was used.
<Comparative Example 8>
Pavement under the same conditions as in Example 1 except that a binder mixture in which 90% by mass of the straight asphalt is replaced with polyamide resin B is used, using an aggregate using the same recycled aggregate as in Example 3. A mixture was prepared.
<Comparative Example 9>
A paving mixture was produced under the same conditions as in Example 1 except that a binder in which the entire amount (100% by mass) of straight asphalt was replaced with polyamide resin B was used.

[Evaluation results]
The pavement mixtures of Examples and Comparative Examples were evaluated by the evaluation method described above. The results are shown in Tables 1 and 2.

The pavement mixture of Examples 1 to 4 to which the polyamide resin C was added and the pavement mixture of Examples 5 to 8 to which the polyamide resin D was added had no problem in workability, and the degree of compaction of the specimen was also high. The value was close to 100%.
Further, the pavement mixture of Comparative Example 1 to which no polyamide resin was added had good workability, but desired physical properties were not obtained under a temperature condition of 60 ° C. close to the pavement surface temperature in summer. Moreover, the pavement mixtures of Comparative Examples 2 to 5 to which the polyamide resin A was added and the pavement mixtures of Comparative Examples 6 to 9 to which the polyamide resin B was added had poor workability and a low degree of compaction. Value. It turned out that the bending strength at the time of the fracture | rupture of the mixture for paving of Examples 1-8 becomes a high value exceeding the design bending strength 4.5MPa of general-purpose concrete for paving. It turned out that the elastic modulus in 60 degreeC of Examples 1-8 shows 5 times or more of a comparative example. In Examples, various other physical properties are improved as compared with Comparative Examples.
Therefore, according to the present invention, it is possible to obtain a pavement mixture that has higher strength after completion of the pavement road surface than conventional petroleum asphalt for pavement and is superior in workability to conventional cement concrete.

Claims (5)

A pavement binder used in a mixture for pavement forming a pavement,
It consists of a polyamide resin alone or a binder mixture of polyamide resin and asphalt,
In the case of the binder mixture, the blending ratio of the polyamide resin is 90% by mass or more based on the total amount of the polyamide resin and asphalt,
A binder for paving, wherein the polyamide resin has a softening point of 70 ° C. or higher and 100 ° C. or lower, and the polyamide resin has a melt viscosity at 180 ° C. of 180 mPa · s or lower.   The paving binder according to claim 1, wherein the polyamide resin includes a carboxylic acid component containing a monovalent carboxylic acid and a polymerized fatty acid, and an amine component containing a polyamine.   The binder for paving according to claim 2, wherein the monovalent carboxylic acid of the carboxylic acid component is 10 to 50 molar equivalent% based on the total amount of the carboxylic acid component.   The paving binder according to claim 2, wherein the amine component is an amine component containing two or more aliphatic diamines.   A paving mixture comprising the paving binder according to any one of claims 1 to 4 and an aggregate.